nitrat de amonio
TRANSCRIPT
19 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
5 Project Description
This chapter provides a detailed description of the various elements of the Technical Ammonium Nitrate Production Facility (TANPF) Project to assist in evaluating the associated potential environmental impacts. The TANPF Project description is based on Burrup Nitrates Pty Ltd (BNPL)’s project concept study. The Engineering, Procurement and Construction (EPC) Contractor has not yet been determined, and as such, certain details of engineering, design and construction are yet to be finalised. Despite this, the design is sufficiently developed to allow for the assessment of potential environmental impacts associated with the TANPF Project.
5.1 Project Overview
BNPL is proposing to construct a TANPF with a production capacity of (circa) 350,000 TPA or 915 MTPD of technical ammonium nitrate (TAN). TAN will be delivered principally to mining customers in the Pilbara, to help make up the basic component of ANFO (ammonium nitrate‐fuel oil) used for explosives. The TANPF will be located at Site D in the King Bay/Hearson Cove Industrial Precinct on the Burrup Peninsula, approximately 13 km northwest of Karratha (the Site), see Figure 1.1 and Figure 4.2. This Precinct lies within the greater Burrup Industrial Estate (BIE), where the WA Government has allocated about 1,400 Ha of strategic heavy industrial land to prospective tenants. The Site is approximately 79 Ha in size and is located adjacent to the existing Burrup Fertilisers Pty Ltd (BFPL) ammonia plant, with site access from Village Road, Burrup Peninsula. The choice of location for the proposed TANPF enables significant sharing of services and utilities between BFPL and BNPL. This will reduce environmental impacts by allowing a smaller project footprint (eg. independent ammonia storage, transport and supply) and permitting the incorporation of technical and design efficiencies. The main feedstock for the proposed TANPF is liquid ammonia, which will be transferred via pipeline from the BFPL plant. The proposed TANPF will require about 35 Ha of the 79 Ha Site. The TANPF will contain three major process units, each producing a separate product in the manufacturing process:
• a Nitric Acid (NA) plant to convert ammonia and atmospheric air into NA;
• an Ammonium Nitrate (AN) Solution plant to convert ammonia and NA into AN solution; and
• a TAN plant to convert AN solution into TAN prills (final product).
The key characteristics of the TANPF Project are outlined in Table 5.1. The boundary locations of the Site are presented in Table 5.2 and Table 5.3. Table 5.1 Key Characteristics of the TANPF
Criteria Key Characteristics of the TANPF
Project Purpose To produce TAN from ammonia using advanced production technology for sale to mostly local markets
Project Life 20+ years
Construction Period Approximately 30 months
Project Value Approximately US $600 million
TANPF Capacity 350,000 TPA
Area of Project Lease 79 Ha (Site D)
Area of Disturbance 35 Ha
Plant Facilities Main Process Units
• Nitric Acid (NA) Plant • Ammonium Nitrate (AN) Solution Plant • Technical Ammonium Nitrate (TAN) Prilling
Plant
Storage, Loading and Transport Facilities
• Liquid Ammonia pipeline between BFPL and BNPL plants
• Bagged TAN storage building • Bulk TAN storage building • TAN Bagging facility • Truck bulk loading system • Nitric acid buffer storage • Ammonium nitrate solution storage
Other Facilities
• Sea Water Cooling Tower • Closed Loop Water Cooling System • Wastewater handling facility • Electrical Power distribution system • Instrument and plant air system • Control room • Steam grid • Administration, maintenance and warehouse
unit • Fire system
Plant Operations The TANPF is designed to operate 24/7, with an average plant availability of 90% (328.5 days per year) excluding any downtime due to market reasons or other reasons not related to operation.
Shutdown Time An annual turnaround of about one week is foreseen. Additional downtime may be caused by a combination of planned stops (e.g. cleaning) and unplanned stops (eg. process, cyclone etc.)
Product Storage Bagged TAN storage building with a capacity of 1,800 MT
Bulk TAN storage building with a capacity of 12,000 MT
Nitric acid buffer storage, two tanks with a total capacity of 3,000 m3 located in a bunded area with acid resistant surface
Ammonium nitrate solution storage (80‐92%), 1 tank with a capacity of 500 MT
Potable Water 2 m3/hr from Water Corporation
Seawater 456 m3/hr from Water Corporation
20 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
Criteria Key Characteristics of the TANPF
Power Requirement 8.5 MW will be required. Of this, about 5 MW will be imported from BFPL.
The remaining power will be generated by excess steam from the operation of the nitric acid plant (about 3.5 MW).
Emergency Power In case of a power outage emergency power will be provided by diesel generators
Energy Input 5 MW from BFPL
Discharge Pipeline Connecting to the Water Corporation facility
Ammonia Pipeline 710 m from BFPL Ammonia plant (storage tanks) to the TANPF (within BNPL and BFPL leases)
Catalysts Platinum (Pt)/ Rhodium (Rh) gauzes for the ammonia combustion
Recovery system for the Pt/Rh gauzes
N2O catalyst
NOx catalyst
Expected Maximum Emissions under Normal Operations:
Daily Load (kg/day)
Per tonne TAN (kg/MT TAN)
Annual Load (kg/year)
NOx 370 0.40 28,318
N2O 466 0.51 161,563
CO2 (produced) 1,279 1.40 515,670
CO 131 0.15 41,987
SO2 trace ‐ trace
VOC (CH4) 51 0.06 17,697
NH3 208 0.22 68,339
AN Dust (Particulate matter) 130 0.14 42,705
Wastewater 11,661 kg/h Process Condensate (non‐contaminated) to sea water blow down. Contaminated water (from cleaning equipment etc) will be sent directly to the contaminated surface water pond.
The non‐contaminated water will be sent to Water Corporation via a pipeline (approximately 3,100 ML/year).
The contaminated water is evaporated in a designated pond which is a closed system (eg. no discharge). Accumulation of unspecified volumes of sludge from the contaminated surface water pond will be collected for disposal as required (estimated once every two years).
Solid Waste Off spec coating removal barrels (expected 120 kg/day max)
Workforce numbers (direct) Construction: Average 400, peak 650 Operation: 60 (full time)
5.2 Project Location
The TANPF Project will be located at Site D (the Site) within the BIE, approximately 13 km northwest of Karratha (Figure 1.1 and Figure 4.2). Geographic coordinates of the proposed Site and the proposed area of disturbance are provided in Table 5.2 and Table 5.3 respectively. Table 5.2 Site D Boundary Coordinates
Latitude Longitude
degrees minutes seconds degrees minutes seconds
20 37 17.815 116 47 8.044
20 37 20.638 116 47 36.463
20 37 57.086 116 47 23.843
20 38 2.246 116 47 7.988
Northings Eastings
477660.256 mE 7719713.884 mN
478479.474 mE 7719628.771 mN
478116.860 mE 7718500.870 mN
477660.230 mE 7718348.890 mN
Table 5.3 TANPF Boundary Coordinates (Area of
Disturbance)
Latitude Longitude
degrees minutes seconds degrees minutes seconds
‐20 37 17.815 116 47 8.044
‐20 37 20.638 116 47 36.463
‐20 37 32.2206 116 47 32.445
‐20 37 35.0904 116 47 17.0586
‐20.626406 37 35.061 116 47 8.0478
Northings Eastings
477660.256 mE 7719713.884 mN
478479.474 mE 7719628.771 mN
478366.280 mE 7719271.240 mN
477924.010 mE 7719182.250 mN
477660.090 mE 7719183.670 mN
5.2.1 Land Ownership and Tenures
Lots within BIE are available for lease to strategic heavy industry through the WA Department of State Development (DSD), which allocate sites through a lease arrangement from LandCorp (WA's land and property development agency). The Site has been allocated to BNPL, subject to the approval of a risk report to be submitted to the WA Department of Mines and Petroleum (DMP) in the coming months.
5.2.2 Zoning
The Site is zoned ‘Strategic Industrial’ under the Roebourne Shire Town Planning Scheme (TPS) No.8. As outlined within the TPS the purpose of the ‘Strategic Industry’ zone is to accommodate such industries as the TANPF. In considering applications for planning approval in the strategic industry zone, the Shire of Roebourne Council shall ensure that the industry (Shire of Roebourne, 2008):
a) ‘Optimises the effectiveness of the zone as a strategic industrial area and…. creates a symbiosis with other industries or includes resource processing industry;
b) ‘is significant to the regional and/or state economies; or
c) ‘Provides goods and services which directly support or complement industries described in a) and b) above; and
d) ‘Minimises or offsets impacts on local infrastructure, economic and community development.’
As noted in Section 2.2.1 planning approval will be sought from the Shire of Roebourne Council following completion of environmental approvals.
21 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
5.2.3 Land Required
Approximately 35 Ha of land within the project lease will be disturbed as part of the TANPF Project (see Figure 4.2). There will be no additional temporary land requirements for the construction phase, as construction laydown areas will be used throughout the operational phase. This land is required to accommodate:
• Processing plants (NA, AN Solution and TAN production)
• Utilities area
• Storages for bagged TAN, bulk TAN, AN solution, nitric acid and chemical store (general process chemicals)
• Truck bulk loading system/Bagging unit
• Off –spec treatment unit
• Other facilities, including: − Sea Water Cooling Tower − Closed Loop Water Cooling System − Clean surface water pond (discharge to Water
Corporation) − Contaminated surface water pond (evaporation pond) − Desalinated/ fire water storage − Control room / Office / Administration − Miscellaneous (internal roads, etc.)
• Lay down areas and access roads. Based on the land requirements of the TANPF, laydown areas and internal roads it is planned that earthworks will be undertaken as described in Table 5.4. Table 5.4 Earthworks and Associated Cut and Fill
Type of Earthworks Volume of Cut/Fill (approximate)
Growth removal 350,000 m2
Strip topsoil & stockpile 19,500 m3
Cut soil 61,900 m3
Load soil/haul/place 92,500 m3
Imported engineered fill is not foreseen
5.2.4 Adjacent Land Uses
Adjacent land uses for the TANPF Project are shown in Figure 5.1 and include industrial facilities present to the south and west of the Site while the proposed Burrup Peninsula Conservation Reserve occurs to the north and south of the Site, with Hearson Cove to the east. The Burrup Peninsula has developed as a major industrial and port site in Australia. Buildings, infrastructure and sensitive receptors within close proximity to the Site are listed in Table 5.5.
Table 5.5 List of Facilities Adjacent to the Proposed TANPF
Facility / Sensitive Receptors Approximate Distance from TANPF (m)
North West Shelf Venture 3,200 m
Woodside LNG Pluto Development 2,200 m
Dampier Port Authority 4,000 m
King Bay Supply Base 3,000 m
Schlumberger Supply Base 2,100 m
BFPL Adjacent, ammonia tanks ~ 600 m
Hearson Cove (visitors) 900 – 1,300 m
Deep Gorge 1,300 m
Nearest Rock Art Site Approximately 400 m
Nearest Rock Art Site within National Heritage Boundary
Approximately 400 m
The north‐south Burrup Road service corridor (see Figure 5.1) extends to the North West Shelf Venture LNG plant in the north and incorporates a power transmission network, a domestic water pipeline and two high pressure underground gas pipelines, the Dampier to Bunbury Natural Gas Pipeline (DBNGP). Currently the BFPL and the Water Corporation multi‐user (both part of the same plot) facilities exist within King Bay/Hearson Cove Industrial Precinct, with the potential inclusion of Dyno Nobel and Woodside Energy yet to be confirmed. No buildings or infrastructure currently exists within the Site.
5.3 Project Schedule
The TANPF is scheduled to begin operations by last quarter 2013. This schedule is based around the following key milestones in Table 5.6. Table 5.6 Project Development Schedule
Project Phase Schedule Timing
Submission of Environmental Scoping Document (ESD) to OEPA July 2009
EPA SU and DEWHA review ESD July‐September 2009
BNPL submits revised ESD September 2009
OEPA approves final ESD October 2009
Submission of PER to EPA SU (and DEWHA) October 2009
EPA SU comments on PER October‐December 2009
BNPL revises PER document December 2009
Approval of PER release for public review December 2009
Public review period of PER (8 weeks) January‐February 2010
BNPL prepares submission summary and response March‐April 2010
EPA SU reviews response to submissions April‐May 2010
OEPA report and recommendations published May‐July 2010
Appeal period on OEPA’s report and recommendations July 2010
State Minister decision August 2010
Commonwealth Minister decision August 2010
Construction Last quarter 2010
Commissioning June 2013
Operation Last quarter 2013
Environmental Resources Management Australia Pty Ltd6th Floor, 172 St Georges Tce, Perth, WA, 6000Telephone +61 9 321 5200
Figure 5.1Adjacent Land Uses to theProposed TANPF
Client:Project:Drawing No:Date:
Drawn by:
Source:Scale:
Burrup Nitrates Pty LtdPER0086269p_GIS04_PER21/12/2009
DD
Base information LANDGATE1:40 000
Suffix No:Drawing size:
Reviewed by:
R1A4
BC
[N
B U R R U PP E N I N S U L A
King Bay
Withnell Bay
CowieCove
Nickol Bay
ProposedDevelopment
Site
0 380 760 1,140m
Legend
Site D Boundary
National Heritage Listed Place (Site ID 105727)
HEARSON COVE RD
VILLAGE RD
BURRUP
RD
North WestShelf Venture
PlutoOperations
DampierPort Authority
SchlumbergerSupply Base
PlutoSupply Base
Hearson Cove
BFPLAmmonia
Plant
Beach & Picnic Area
DeepGorge
23 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
5.4 Characteristics and Properties of the TANPF’s Main Raw Materials and Product
5.4.1 Nitric Acid
Nitric acid is a colourless, yellow, or red, fuming liquid with an acrid odour. The acid is often used in an aqueous solution. Fuming nitric acid is concentrated nitric acid that contains dissolved nitrogen dioxide. Table 5.7 Properties of Nitric Acid
Nitric Acid (HNO3)
Chemical Abstracts Service (CAS) Number 7697‐37‐2
Registry of Toxic Effects of Chemical Substances (RTECS) Number
QU5775000
Immediately Dangerous to Life or Health (IDLH)
25 ppm
Exposure Limits National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL): Time weighted average (TWA) 2 ppm (5 mg/m3)
Occupation Safety and Health Administration (OSHA) permissible exposure limits (PEL): TWA 2 ppm (5 mg/m3)
National Pollution Inventory (NPI) Ranking 43 of 90
Molar mass 63.012 g/mol
Physical Description Colourless, yellow, or red, fuming liquid with an acrid odour
Freezing Point At 60% conc.: –22oC
Boiling Point At 60% conc.: 120oC
Specific Gravity At 60% conc. and at 25oC: 1,360 kg/m3
Solubility in water completely miscible
Flash point Non‐combustible Liquid, but increases the flammability of combustible materials
Dangerous Substances Directive Oxidant, Corrosive
5.4.2 Ammonia
Anhydrous ammonia is a colourless non‐flammable liquefied gas. Its vapour is lighter than air [(vapour density of 0.6) air = 1] and has the same pungent odour as household ammonia. Although ammonia vapour is lighter than air, vapours from an accidental leak are likely to hug the ground appearing as a white cloud. Chemically ammonia is 82% nitrogen (N) and 18% hydrogen (H).
Table 5.8 Properties of Ammonia
Ammonia (NH3)
CAS Number 7664‐41‐7
RTECS Number BO0875000
IDLH 300 ppm
Exposure Limits NIOSH REL: TWA 25 ppm (18 mg/m3)
OSHA PEL: TWA 50 ppm (35 mg/m3)
National Pollution Inventory (NPI) Ranking 45 of 90
Molar mass 17.031 g/mol
Physical Description Colourless gas with strong pungent odour. It is easily liquefied under pressure
Freezing Point ‐77oC
Boiling Point ‐33oC
Solubility in water 1176 g/100 mL (0°C)
702 g/100 mL (20°C)
88 g/100 mL (100°C)
Flash point Non‐combustible as a Gas
Dangerous Substances Directive Toxic, Corrosive, Dangerous for the environment (if released uncontrolled)
5.4.3 Technical Ammonium Nitrate
The chemical compound ammonium nitrate (NH4NO3) is a salt of ammonia and nitric acid. Ammonium nitrate (AN) is a colourless, crystalline substance and has a melting point of 169°C and decomposes above 210°C. It is highly soluble in water and soluble in alcohol and liquid ammonia. AN is not in itself combustible but, as it is an oxidising agent it can assist other materials to burn, even if air is excluded. AN can be manufactured into several different grades to suit different purposes. Fertiliser‐grade AN is manufactured in a solid form (granules/ prills), with low porosity, in order to achieve more stability and less sensitivity to detonation. Technical grade AN, or TAN, is developed into prills which are made to be porous for better absorption of fuel and higher reactivity when mixed with fuel oil and used as an explosive, see Figure 5.2. Figure 5.2 Photo of TAN Prills
Scale (mm)
0 4 8
Scale (mm)
0 4 8
Scale (mm)
0 4 8
24 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
TAN will be the main product from the TANPF Project. TAN prills will be produced with specifications similar to that in Table 5.9. The TAN prills will be used in the local market for use in ANFO (ammonium nitrate‐fuel oil) explosives. Table 5.9 Specifications of TAN Prills (typical)
Technical Ammonium Nitrate Prills (TAN)
CAS Number 6484‐52‐2
RTECS Number BR9050000
Molar mass 80.043 g/mol
Physical Description White Solid
PH 5
Melting Point 169°C
Boiling Point approx. 210°C decomposed
Solubility in water 118 g/100 ml (0°C)
150 g/100 ml (20°C)
297 g/100 ml (40°C)
410 g/100 ml (60°C)
576 g/100 ml (80°C)
1024 g/100 ml (100°C)
Shock/Friction Sensitivity Very low
Nitrogen Content 34.5% w
Bulk Density 0.70 – 0.83 kg/L
Free Moisture 0.03‐0.16%w
Oil Absorption 8%‐14%w
AN is classified as a Class 5.1 oxidising agent and is designated in the III packaging group (minor danger) in the Australian Dangerous Group code. There are three main hazards associated with ammonium nitrate:
• fire due to its oxidising nature;
• decomposition; and
• explosion resulting from rapid deflagration, or detonation. The most important parameters that influence the hazard and increase sensitivity to explosion are:
• particle size;
• particle density/bulk density/porosity;
• contamination with organic substances, certain metals and chlorides; and
• confinement.
Fire
AN itself does not burn. As an oxidiser, however, it can support combustion and intensify a fire even in the absence of air, but only as long as fuel or combustible matter is also present. Gases are then emitted, especially nitrogen oxides. In addition, AN melts at 169°C, when pure. The melting absorbs some of the energy received and the melted product often flows away and escapes the external energy source.
Decomposition
Pure AN can undergo thermal decomposition if it receives enough energy. Gases are then emitted, especially nitrogen oxides and ammonia, both toxic. Heating in confinement is a risk when ventilation is inadequate. The rapid decomposition of the AN leads to a considerable pressure build‐up that can eventually cause an explosion. With proper ventilation, the decomposition stops as soon as the energy flow stops. The decomposition rate is not dangerously high at moderate temperatures, and the overall thermal effect is not significant since the exothermic reactions are accompanied by endothermic disassociation, which can in turn give rise to a steady state reaction provided the gases produced can escape freely and the system is adiabatic. The decomposition is catalysed by a number of substances such as chlorides, which can affect the above balance.
Explosion
AN can produce an explosion by one of three mechanisms:
• heating in confinement;
• run‐away reaction; and
• detonation. The effects of heating of AN are described above. A runaway reaction is achieved when the heat generated by the reaction exceeds the heat loss by a significantly high margin. For pure AN, these circumstances are difficult to achieve given its low decomposition rate and endothermic effect when unconfined. Pure AN is not shock or friction sensitive and cannot be induced to detonate under normal storage conditions; detonation, which are characterised by a supersonic pressure wave moving through the material, can occur only if the dimensions of the material are greater than some particular value known as “The critical charge diameter”. For solid AN this diameter is more than 1 m and decreases with decreasing bulk density of the solid AN. The corresponding diameter for decomposing molten AN is about 10 cm. Uncontaminated and unconfined AN is very difficult to detonate. Neither flame, nor spark nor friction can cause a detonation. Deflagration is not constrained by dimensions and is said to occur when a subsonic combustion generated pressure wave moves through the material. The consensus of opinion on AN hazards is that, in the event of a large fire at an AN store, a pool of liquid ammonium nitrate will be formed at the side of the stack that is nearest to the fire. If this pool is struck by a high speed missile (eg. something falling or part of a drum that has exploded) then a local explosion may occur sending a shock wave into the main AN stack that has not melted and that could lead to deflagration.
25 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
Stacks of AN in the open are assumed to be incapable of exploding because the probability of an explosion trigger such as a girder falling into a molten pool is very low.
5.5 Design Considerations
5.5.1 HES Design Standards
The Health Environment and Safety (HES) premises for the TANPF Project provide a minimum set of standards to ensure that identified risks to people, assets, environment and reputation have been addressed in the project design. The design mitigations together with the management measures will ensure they are acceptable to As Low As Reasonably Practicable (ALARP) levels. The HES requirements of the TANPF Project start with compliance with the applicable Commonwealth and WA legislation and relevant international agreements to which Australia is a party, as specified in Annex C. In addition, Yara Policies, Standards, Procedures and Guidelines have also been applied, with the stricter of the standards always applying. The design of the TANPF Project adheres to sound engineering practice and is based on the most recent standards and/or codes as summarised below:
• Australian regulatory requirements.
• Applicable International Codes, Standards and Guidelines.
• Applicable Yara standards and guidelines for this kind of facility.
• Applicable BFPL standards.
5.5.2 Emissions Reduction
The design of the TANPF incorporates a number of measures to reduce its emissions and carbon footprint. The TANPF will use BAT to minimise emissions to ALARP. The majority of emissions that will occur from the TANPF will come from the main process units:
• Nitric Acid (NA) Plant;
• Ammonium Nitrate (AN) Solution Plant; and
• Technical Ammonium Nitrate (TAN) Prilling Plant. The following Best Available Technology (BAT) will be used to help reduce air emissions from the TANPF.
Nitric Acid Plant
The NA plant will use the dual pressure process, which ensures optimal conditions in the combustion as well as in the absorption stages to accommodate stringent environmental pollution control requirements. In addition, the NA plant will apply BAT for further abatement of N2O and NOx. In the NA plant some N2O will be formed in the burner where ammonia is oxidised by burning with air in the presence of a catalyst. The formation of N2O is minimised by proper raw material filtering, gas mixing and distribution to the catalytic gauzes in the ammonia burner (the optimal conditions to minimise N2O formation are to be considered in the final process design phase). N2O emissions also follow the process stream and ends up in the tail gas (waste gas emitted to the atmosphere). With N2O already being reduced through the NA process, N2O in the tail gas is further reduced by catalytic reduction. This technology is to be finalised as part of the process design. While some final design is still required to take place, BNPL will ensure that the emissions of N2O in the tail gas (after catalytic abatement) vented to the atmosphere will be less than 100 ppm (as a minimum), which corresponds to a maximum emission of 6.1 t/h of CO2e and an overall reduction of CO2e emissions of approximately 90%. The catalytic process for N2O reduction requires the use of some natural gas, with the maximum consumption to be 50 Nm3/h. This use of gas will result in CO2 formation, with a maximum emission of 0.064 t/h. Some slippage of methane will occur which will correspond to a maximum value of 0.045 t/h CO2e. These additional emissions from the use of a N2O reduction catalyst are required as they result in a far greater CO2e reduction (approximately 90% reduction) than operations without a N2O reduction catalyst. The NA plant will have no boiler installed for continuous production of steam or electricity as the process itself is exothermic and generates its own requirements for steam which is used to generate electricity. In addition BFPL will provide the utilities where required for start up steam and energy. Consequently, there will be no Scope 1 CO2 emissions from the NA plant resulting from burning of fossil fuels except as mentioned above for N2O abatement where a small amount of natural gas is used via BFPL’s facility.
Ammonium Nitrate Solution Plant
The AN solution plant will use a Neutra (vacuum) synthesis process to provide lower reactor temperatures that will result in increased safety, reduced level of aerosols and very clean condensates (levels around 15 ppm NA and 15 ppm NH3). Furthermore, all vapours produced in the process will be condensed and the condensate reused to avoid unnecessary emissions to the atmosphere.
26 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
Technical Ammonium Nitrate Prilling Plant
The TAN prilling plant will also use BAT to minimise atmospheric emissions. The prill tower of the TAN prilling plant will be designed with a recycle air closed loop air recycling system to minimise the total amount of air rejected to the atmosphere (less than 1/3 compared to open loop prilling). This gives one single emission point expected to be well below European Fertilizer Manufacturers Association (EFMA) Best Available Techniques 2000 levels. In addition, all exhaust from the prill tower will be cleaned in two stages using efficient abatement systems.
5.5.3 Safety and Security
As well as environmental aspects, safety and security considerations have significantly influenced the design of the TANPF. Yara has developed Technical and Operational Standards (TOPS) that will be implemented in the design and engineering as well as for the operation and maintenance of the TANPF. Yara’s TOPS have been developed following over 40 years of operational experience of TAN plants to provide safe and reliable design and operation of equipment, individual process units and plants. The standards are divided into different categories:
1) Standards applicable to all Yara/BNPL operations
2) Maintenance
3) Nitric acid
4) Ammonium nitrate
5) Industrial/CO2
6) Transport, loading/unloading TOPS does not replace the TANPF Project’s compliance with national and international codes and standards, but are supplementary and provide specific know how and experience acquired by Yara from designing and operating similar facilities for extended periods. Statutory regulations shall always be complied with. In the case of a difference between statutory requirements and TOPS, the more stringent shall apply. Generally, all raw materials and chemicals used in the TANPF will be controlled according to TOPS to ensure correct quality and to avoid contamination of areas that may jeopardise safety and health. In addition, a number of analyses (both on‐line and regular spot checks) will be performed during operation of the TANPF to ensure correct and safe operating conditions, to assess the possible presence of contaminants and to maintain product quality. Critical operating parameters in the various process units that make up the TANPF will also have automatic controls with trip functions to shut down the process safely if a set safety limit is exceeded. Cameras for surveillance of the main process plants and product storage areas will be installed and monitored.
TANPF Main Process Units
The dual pressure nitric acid process has been selected for its reliability, long on‐stream time and efficiency. The turbo‐machinery, as well as other key equipment, will be designed with emphasis on reliability and safety. In compliance with stringent internal pollution abatement requirements an N2O/NOx catalyst based abatement system will also be installed (as discussed in Section 5.5.2). The AN solution plant technology selected represents a reliable process characterised by using forced circulation over the reactor to avoid local overheating and to allow operation at low temperature. The pH of all product will be automatically controlled at several points to ensure safe conditions and, if required, ammonia would be added to maintain correct conditions. The quality of the acid fed to the neutraliser, as well as the AN solution produced, will also be checked on a regular basis to ensure possible contaminants do not exceed acceptable limits. The TAN prilling plant will use an organic internal additive to achieve optimal product characteristics. For safety reasons very low levels of organic material in the TAN solution/product will be allowed. A number of control mechanisms (on‐line as well as manual) will be implemented to ensure that organic limits are not exceeded.
TAN Storage
TAN product will be stored on site as bulk and bagged product. More details on the storage of TAN product is described in Section 5.6.5 below. As part of the evaluation of risk associated with storing of TAN at the Site, internationally renowned Dutch research institute, TNO, a specialist in assessing risks of these types of storages, was consulted. Based on simulations by TNO, it has been concluded that for two separated bulk piles of TAN the occurrence of a sympathetic detonation is extremely unlikely, even for separation distances smaller than 1 metre (m). A consequence of this is that the bulk product will be stored in several smaller piles, and not one large pile, with a clear separation distance (about 1 m). Additionally, no solid objects will be located between the piles since such objects could be strongly accelerated by a blast wave and could subsequently impact with other piles of TAN and generate very high pressure in the acceptor resulting in a potential detonation. For bagged TAN product storage similar simulations have been performed by TNO to calculate the safe distance between product stacks as well as configuration of the stacks. The optimal bag configuration (bags of 750 kg to 1250 kg) is a bulk‐wise stacking (eg. 12+9+6), with each consecutive layer is 1.5 bags staggered towards the centre (giving a pyramidal shape), see Figure 5.3. With this configuration a separation distance of 7 – 9 m (depending on product grade) will be sufficient to prevent a sympathetic detonation between two stacks. The big bags will therefore be stacked in a bulk‐wise
27 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
configuration with 3 layers and about 300 tons or less in each stack and with a distance of 7 – 9 m between the stacks. Floor marking will ensure that safe stacking zones are maintained. Figure 5.3 Optimal TAN Bag Stacking Configurations
Plant Operation
The process safety and all relevant procedures of the TANPF Project will be set out in a document that describes the minimum requirements to be implemented. In addition to process safety, there will be a focus on housekeeping since this is considered of paramount importance to avoid contamination of products, raw materials and chemicals that could have adverse effects on safety in the TANPF or later in the product handling chain. Safe plant operation is a key focus of BNPL and ensuring proper maintenance is a key to safe operation. Important elements in achieving optimum safety, performance and reliability of operating equipment are systematic maintenance and condition monitoring. Details on how this is done will be described in the TOPS for maintenance, which will be implemented for the TANPF. Other important elements are modifications/ management of change, work permits and associated risk assessment/job safety analysis. All modifications of process systems and process equipment will have to be approved based on a systematic review of HES issues.
Fire prevention requirements have also been included in the design of the TANPF (eg. use of materials). This is related to process units, buildings, and material handling and product storages. Prior to commissioning and operations, a detailed fire risk assessment will be carried out and the Site will be classified into fire cells with respect to probability and potential consequence of a fire. Based on this, necessary fire protection will be implemented (eg. fire wall/barrier, conveyor belt material, fire detection systems, fire extinguishing systems). To ensure safe management of the product from the TANPF, BNPL will apply the principles and requirements of the EFMA’s Product Stewardship program, considered to be European accepted practice. This will involve management of the TAN product throughout all stages of its lifecycle (development, materials procurement, manufacturing, distribution and use) in a safe way with respect to health, environment, occupational and public safety, and security. As an example, dedicated carrier(s) will be used for transporting TAN, with all operators (drivers), as well as vehicles, to be certified for the particular purpose. The Product Stewardship program will comply with all Commonwealth and State legislation and where the program and legislation cross over, the stricter of the two will apply. An annual safety program will be designed and established to maintain a safe and healthy work environment for all employees and contractors. All employees will be required to successfully complete a safety training program prior to gaining approval to work on the TANPF Project to achieve and maintain the level of competence required. Safety training will also be mandatory for all contractors on site.
TANPF Security
The core of the security network for the TANPF will be surveillance cameras for the complete fenced perimeter and a gatehouse that will be manned 24/7 to control/register all incoming/outgoing traffic (vehicles as well as individuals). Different areas within the TANPF will have different classification (eg. access granted to authorised personnel only, access when accompanied by an employee, limited access outside normal working hours etc.). Employees will be equipped with ID/access cards to be worn and clearly displayed at all times. All employees and temporary staff will receive necessary security training. The site manager will ensure that temporary staff from outside BNPL, as well as suppliers of goods and services to BNPL, are certified by checking credentials following established procedures. Prior to commissioning and operations, an emergency plan will be developed for the TANPF for handling of accidents and incidents with risk to life, property and the environment. The TANPF will be certified to ISO 9001 (quality), ISO 14001 (environment) and to OHS AS18001 (safety) standards to ensure the highest quality of safety and environmental management.
28 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
The TANPF will also be audited on a regular basis using internal and/or external auditors to ensure compliance with the various TOPS as well as regulations, codes, standards and WA and/or Commonwealth Ministerial conditions.
5.5.4 Unplanned Events
An Emergency Response Plan covering all credible HES emergency scenarios (including tropical cyclone response) during all phases of the project and the escalation potential of any emergency situation will be developed for the TANPF Project and is discussed further in Section 8.11.4. All process structures and vessels will be designed for seismic actions, eg. earthquakes, in accordance with AS 1170.4‐2007.
5.5.5 Extreme Weather Events Cyclone Design and Precautions
Throughout the design of the TANPF Project extreme weather events have been extensively analysed to ensure that the TANPF will withstand extreme weather events. The TANPF has been designed for an operating life of 20 plus years. Accepted international design criteria have been used for proper sizing of equipment, buildings and other structures considering the extreme weather conditions likely to be experienced at the Site. Storm‐water drains have been designed for 105 mm/h rainfall. The buildings will also be built to handle wind velocities up to 300 km/h in any direction at 10 m above ground.
In the event of flooding due to a heavy rainfall and/or storm surge, the TANPF (including clean surface water ponds and other areas of potential areas of contamination) will be raised to at least 5.5 m AHD to avoid any serious safety and/or environmental accidents associated with these events (see Annex E). The clean surface water pond will have an area of 40 m by 25 m, and a depth of 1.5 m. The contaminated surface water pond will have an area of 70 m by 70 m, and a depth of 1.5 m – both ponds will be bunded. Preliminary plans of the drainage design are shown in Annex F. The TANPF design level incorporates the potential for future sea level rise for the 20 year plus operational phase. The TANPF may be further raised depending on the outcome of geotechnical work to be undertaken prior to construction.
5.6 TAN Process Description and Associated Infrastructure
5.6.1 Introduction
The TANPF will be positioned in the northwest corner of the Site (Figure 4.2). The plant layout is shown in Figure 5.4 and Figure 5.5.
Figure 5.4 3D Model of Plant
30 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
The TANPF will comprise of the following main project elements:
• Main Process Units, including: − Nitric Acid (NA) Plant; − Ammonium Nitrate (AN) Solution Plant; − Technical Ammonium Nitrate (TAN) Prilling Plant;
• Storage, Loading and Transport Facilities;
• Other Facilities and Buildings; and
• Supporting Infrastructure and Communications. Figure 5.6 below represents a simplified visual illustration of the TAN production process. This is followed by an overview of each main processing unit within the TANPF. Figure 5.6 TAN Production Process
5.6.2 Nitric Acid Plant
The NA plant will be based on the dual pressure process and will:
• Have a capacity of 760 MTPD NA (as 100 wt %);
• Require ammonia and oxygen (air) as raw materials;
• Generate about 3.5 MW of power from excess process steam which will be used to drive compressors in the NA plant;
• Be designed to operate between 70 and 100% load; and
• Produce NA (approximately 60% concentration) that will be sent to the AN solution plant.
The following outlines the various unit operations and processes within the proposed NA plant. Additional information is contained in Table 5.10.
Ammonia / Air PreTreatment
Air is initially filtered in a two‐stage filter system. This is followed by compression in an air compressor that does not require any inter‐stage cooling. The compressed air is then split into two sections with the primary air going to the ammonia burner while the secondary air is sent to the nitric acid bleacher. Liquid ammonia feed is evaporated, superheated (using steam) and filtered to remove impurities. The superheated ammonia is then injected into the primary air and mixed before being fed to the ammonia burner.
Nitric Acid Synthesis
The compressed air/ammonia mixture enters the burner and passes through a gas distribution system. At the platinum gauzes, ammonia is combusted to Nitrogen Oxide (NOx) at a temperature around 890 to 900°C. In the downstream piping and equipment, NO is oxidised to NO2 generating additional heat that is used in the heat recovery network. The gas is cooled down further and condensed, forming nitric acid with around 40% by weight in the weak acid condenser. The acid is then separated from the process gas and pumped to the appropriate tray in the absorption tower. The process gas is compressed to the selected absorption pressure. The compressed gas is used to heat the tail gas. In the absorption tower, NOx gases are absorbed into water to form NA. The gas leaving the absorber (tail gas) is expected to have a NOx content of approximately 400 ppm, depending on pressure and chilled water temperatures. The tail gas will then enter the abatement reactor (N2O/NOx reduction unit). This reduction unit utilises BAT, and the tail gas vented to the atmosphere from the TANPF will comply with statutory requirements and environmental guidelines. After the abatement reactor the tail gas will enter the tail gas turbine where it is expanded to recover 70% of the power demand for the compressor train. The acid concentration will be optimised to match the AN plant requirements, but will be approximately 60% by weight. Heat generated from the acid production operation is partly used for the production of steam and for the generation of electricity and only the remaining heat is removed into the chilled water and sweet water cooling loops.
31 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
Table 5.10 NA Plant Summary Development
Nitric Acid Plant
Inputs/quantities or volumes
Outputs/Products Outputs/Wastes & Emissions
Ammonia:
8,977 kg/h
Air:
160,359 kg/h or 51,629 m3 /hr
Water (saline, potable):
No consumption directly in process
Power:
3.5 MW internal generation (Steam from NA Plant)
0.38 MW internal consumption
Produce NA (approx. 60% concentration) – 52,778 kg/h or 39.8 m3/hr as an intermediate product that will be sent to the AN solution plant
1) Air Emissions
• N2O
- Normal operation 100ppm or 19.4 kg/hr
- Max1 2,000 ppm or 180 kg/hr
• NOx
- Normal operation 75ppm or 15 kg/hr calculated as NO2
- Max1 700 ppm or 100 kg/hr calculated as NO2
• CO2
- Normal operation 250ppm or 49.5 kg/hr
- Max1 400 ppm or 79.42 kg/hr
• CO
- Normal operation < 40ppm or < 4.45 kg/hr
- Max1 40 ppm or 4.45 kg/hr
• CH4
- Normal operation 30ppm or 2.1 kg/hr
- Max1 100 ppm or 7.1 kg/hr
• NH3
- Normal operation 1 ppm or 0.08 kg/hr
- Max1 5 ppm or 0.4kg/hr
• H2S
- Normal operation, traces only
- Max1, traces only
2) Liquid Emissions
• Oil residue and sludge from the heat exchangers and storage tanks, minimal quantities
3) Catalysts • The Pt/Rh catalyst gauzes and
the catchment system will be completely changed and recycled approximately two times a year.
• The NOx and N2O catalyst has a life time of approximately 10 years and will be returned to the manufacturer
1. Max values are associated with upset conditions and include start‐up and shutdown, which do not generally last more than 4 hours.
5.6.3 Ammonium Nitrate Solution Plant
The AN solution plant will apply the vacuum neutralisation technology and will:
• Have a capacity of 965 MTPD AN (as 100 wt %) to match the NA plant capacity;
• Require ammonia and nitric acid as raw materials; and
• Produce AN solution that is either sent to the TAN prilling plant or stored.
The following is an overview of the AN solution plant process. Additional information is contained in Table 5.11.
Ammonium Nitrate Synthesis
Superheated gaseous ammonia at about 90°C and preheated liquid nitric acid (approximately 60 wt%) at about 65°C are injected into the bottom part of a forced circulation neutraliser. The reaction is exothermic in nature and requires good control of feeds. The molar ratios of reactants are controlled automatically. Nitric acid flow controls the main flow of ammonia. The circulating stream leaving the neutraliser enters a cyclone separator operating under slight vacuum providing flash evaporation of the solution giving a concentration of about 93 wt%. The temperature rise in the neutraliser will be limited to 145°C. Table 5.11 AN Solution Plant Summary Development
Ammonium Nitrate Solution Plant
Inputs/ quantities or volumes
Outputs/Products Outputs/Wastes & Emissions
Ammonia:
8,630 kg/h
Nitric Acid:
52,756 kg/h as 60% concentration
Water (saline, potable):
no water consumption
Power:
(BFPL or internal) ‐ 105 KW
Produce AN solution: 43,300 kg/h max and 40,300 kg/h nominal as 93% will be used for TAN production.
1) Air Emissions
• None
2) Liquid Emissions
• Clean condensate (15 ppm N from both ammonia and AN) is used in the scrubber and as make‐up water
• Blow down, containing suitable contamination concentrations to be exported to the Water Corporation (about 12 m3/h).
1. Max values are associated with upset conditions and include start‐up and shutdown, which do not generally last more than 4 hours.
2. Nitric acid emissions of off vapours can be produced from the neutralisation reactor in the TAN plant. However, all off vapours produced will be condensed back into the system, ie. it is a closed system, therefore there will be no emissions.
5.6.4 Technical Ammonium Nitrate Prilling Plant
The TAN prilling plant will be designed based on the Yara process for final evaporation and prilling/drying/cooling, and will:
• have a capacity of 915 MTPD prilled TAN (as 100 wt %);
• require AN solution as raw materials; and,
• produce TAN prills that are either bagged or stored in bulk and then sent via truck to customers.
In order to generate products of the specified properties, a number of unit operations and processes are required, as described below. Additional information is contained in Table 5.12.
32 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
Ammonium Nitrate Solution Concentration
The AN solution from the neutraliser is sent to a falling film evaporator that operates under vacuum. Evaporation ultimately results in a product concentration up to 96.5 wt% AN.
Additive Preparation
To produce the higher density grade AN, an additive known as permalene is required. This permalene solution (25%) is prepared from the raw materials boric acid, ammonium sulfate and diammonium phosphate. On the other hand, lower density AN is produced by the introduction of an organic additive. Note that for safety reasons, this organic additive is introduced just before the prill nozzle. The additives are either produced on site or are delivered as ready‐made chemicals.
Prilling
The AN solution is pumped to the top of the prilling tower. Here, the solution flows by gravity to the prilling nozzles where they form droplets that crystallise as they fall from the top of the tower. The cooling air required for crystallisation of the AN is recycled to limit atmospheric emissions, while cool and hot air generated is reused via a series of unit operations.
Drying
Prills exiting the prill tower are directed to the drying section for reducing the moisture content from 3 – 4 wt% to 0.05 – 0.2 wt%, depending on grade. This is achieved via either co‐current or counter current dryers. This unit operation removes most of the water present and results in a porous product.
Cooling and Conditioning
Dried prills are screened before being fed to the fluidised bed cooler. Oversizes and fines are removed and recycled while the on‐spec prills are cooled to the optimal storage temperature. The fluidised bed cooler is a two stage cooler with intermediate air recycle. The air usage in this section is also integrated to other sections of the facility, which is a good means of achieving higher economic and environmental viability. The cooled product is finally sent to a coating drum where anti caking agents are sprayed on. Table 5.12 TAN Prilling Plant Summary
Technical Ammonium Nitrate Prilling Plant
Inputs/ quantities or volumes
Outputs/Products Outputs/Wastes & Emissions
AN solution:
40,300 kg/h as 93% concentration
Nitric Acid:
290 kg/h as 60% conc.
Produce Prilled TAN 38190 kg/h
1) Air Emissions
• AN Dust particles
- Normal operation 2.8 kg/hr
- Max1 5.4 kg/hr
• NH3
- Normal operation 2.3 kg/hr
- Max1 8.7 kg/hr
Technical Ammonium Nitrate Prilling Plant
Inputs/ quantities or volumes
Outputs/Products Outputs/Wastes & Emissions
Prill Coating:
38.5 kg/h
Internal Additive:
26.5 kg/h (2 types organic or inorganic)
Water (saline, potable)
2 m3/hr desalinated water
Power
BFPL or internal) ‐ 3.04 MW
• Continuous emissions will be cleaned in several stages culminating in a common scrubber that vents to the atmosphere to meet statutory requirements. During normal operation the ammonium nitrate and ammonia emission to atmosphere will be 2.3 and 2.8 kg/h, respectively.
2) Liquid Emissions
• Occasional floor washings, drains, drips rainwater etc (about 4 m3/day).
• Atmospheric moisture condensation from plant air‐conditioning, about 1.9 m3/h
1. Max values are associated with upset conditions and include start‐up and shut‐down, which do not generally last more than 4 hours
5.6.5 Storage, Loading and Transport Facilities
Bulk TAN Storage Building and Truck Bulk Loading System
The bulk TAN storage will have a capacity of 12,000 MT. The storage/layout of the product piles are based on recommendations from the world renowned Dutch research institute TNO to ensure safe conditions (see Section 5.5.3 for further details). As a consequence the storage will have several bulk piles with a distance of about 1 m to avoid sympathetic detonation. Due to the ambient temperature of the Pilbara region, the bulk storage will have a special roof construction to maintain temperatures within acceptable levels. Air dehumidification or conditioning is likely to be further considered to improve the storage if deemed necessary. The final TAN product leaving the TAN prilling plant will be conveyed to the bulk storage or directly to the truck loading area (including weight bridge). The truck loading can also be fed from the bulk storage using a front end loader and conveying system. Bulk TAN will be transported to the consumers by trucks only, which will be loaded using a system consisting of front loaders, bucket elevators and silos in combination with a truck weighing system. Approximately 25 trucks will operate per day for the transport of products (including bulk, bagged and solution), with all trucks fully authorised with licensed/certified operators.
Bagged TAN Storage Building and Bagging Facility
The storage for bagged TAN product will have a capacity of 1,800 MT. The product will be stored in stacks of about 300 MT or less and with minimum 7 ‐ 9 metres between the stacks using a stacking configuration recommended by TNO (see Section 5.5.3 for further details).
33 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
The bagging facility will have a capacity to bag TAN into 1,000 – 1,250 kg bags. Product that is to be bagged will also be reclaimed from the bulk storage and conveyed to the bagging plant. Forklifts will be used to transport bagged products to the bagged TAN storage building. Bagged products will be transported to customers using trucks as discussed above.
Nitric Acid Buffer Storage
Two tanks with a total capacity of 3,000 m3 will be located in a bunded area with an acid resistant surface.
Ammonium Nitrate Solution Storage
Excess AN solution will be stored at concentrations of 80 – 92% within a 500 MT tank that will be located in a bunded area. AN solution may be loaded on trucks from the AN storage tank which will be provided with a necessary loading system. If AN solution is sold, it will be transported to customers using trucks as discussed above.
Chemical Storage
As part of the TAN production process, certain organic and inorganic chemicals will be required to be stored on site for numerous process requirements. The chemicals to be stored on site are described below, including any requirement for bunding or other specialised storage procedures required. Unless otherwise specified, all chemicals not being used will be stored in the chemical storage building.
• Inorganic internal additives ‐ These are required to be stored as dry material on site. These materials will be bagged and handled by forklifts for the preparation of the additive solution that will be directly pumped into the TAN process (approx 1.5 month consumption). The major inorganic additives to be stored on site are: − 20 MT Boric acid in 1 MT big bags. − 20 MT Di Ammonium Phosphate in 1 MT big bags. − 5 MT Ammonium Sulfate in 25 kg small bags.
• Organic internal additives ‐ Organic additives have the potential to interact with TAN and other products on site if not carefully managed. Organic additives shall be stored in separate bunded areas to prevent mixing with product. The chemicals shall be delivered in truck/containers and pumped into the storage. The key organic additive to the TAN process will be:
− Sulphonated naphthalene – 20 MT in powder form in 500 kg bags (to be used to prepare a solution that will be pumped into the process), or 25 MT of ready made solution (approx 1.5 month consumption).
− Coating Agent (Amine wax) – 35 MT as melted wax pumped directly into the process. This shall be delivered as a wax that may need heating for transfer into storage tank (approx 1.5 month consumption).
• Laboratory chemicals ‐ Most of the laboratory analysis shall be performed in the main laboratory, located at the BFPL plant site. The only frequent analysis requiring chemicals that shall be performed on the premises of the TANPF will be moisture content using the Karl Fischer method that requires the following chemicals, which will be stored in the chemical store: − Methanol 200L (equivalent to one year of usage). − Karl Fisher reagent 20L (equivalent to one year of
usage).
• Chemicals for NA plant – The following chemicals, when not being used, will be stored in the chemical store: − Hydrogen (99% conc.) – Will be used to ignite the
burners in the NA plant. Approximately twenty 50L bottles will be required in first year, with 12 bottles per year after that. Approximately four bottles will be stored at the nitric acid plant and the remaining in the chemical store.
− Nitrogen (99.5% conc.) ‐ Will be used for utility stations and purging of equipment. Four 40L bottles will be stored in the chemical store for annual use.
• Calibration gases for the tail gas analysers of the NA plant ‐ Consumption will be based on the intervals of calibration (yet to be determined). The following gases will be used with each to be stored in 40L bottles: − Nitrogen ‐ Consumption about 4 bottles per year. − N2O/NO/CH4/N2 mix ‐ consumption about 1 bottle per
year. − N2O/NO/N2 ‐ consumption about 1 bottle per year. − NO2/Air mix ‐ consumption about 1 bottle per year. One complete set (one of each above) of calibration gases will be installed in the analyser container in the NA plant. The other remaining bottles for the yearly consumption will be stored in the chemical store.
• Other chemicals – Other chemicals to be used on site are as follows, with all chemicals to be stored in the chemical store unless otherwise specified: − Trisodium phosphate ‐ For pH adjustment of boiler
water. Consumption of about 100 kg per year. − Oxygen scavenger (Eliminox) ‐ for removing rest oxygen
in the boiler feed water. Consumption of about 100 L per year.
− Cleaning chemicals like acetone for removing of oil. Consumption of about 200L per year.
− Chemicals for neutralisation of acidic wastes (NaOH). Consumption of about 200L per year. To be stored near the contaminated surface water ponds in appropriate storage.
− Chemicals for neutralisation of alkali wastes (HNO3). Consumption of about 200L per year. To be stored near the contaminated surface water ponds in appropriate storage.
− Corrosion inhibitor Natriumhypochlorid (NaOCL) to be stored in the NA plant in a 30 m3 tank. Continuous consumption during operation of about 3.5 kg/h.
34 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
− Biocide ‐ To be mainly stored in a 1 m3 container at the NA plant from where a 300L day tank will be fed. There will be continuous consumption during operation of about 0.5 L/h. Depending on delivery more containers may be stored in the chemical store.
− Scale inhibitor ‐ To be mainly stored in a 1 m3 container at the NA plant from where a 300L day tank will be fed. There will be continuous consumption during operation of about 0.75 L/h. Depending on delivery more containers may be stored in the chemical store.
Diesel Storage
An onsite above ground diesel fuel store of a capacity of approximately 12 m3 will be installed to provide refuelling for the payloaders and possible feed to the emergency diesel generator day tank. This tank will be located in an appropriately bunded area. During pre‐commissioning, commissioning and start up some additional quantities of diesel may be required. These will be stored appropriately as described above.
Liquid Ammonia Pipeline
The TANPF will receive liquid ammonia from the adjacent BFPL plant via a 710 m long, insulated 4 inch diameter pipeline, to run between the BFPL and TANPF sites within each respective lease (see Figure 4.2). To reduce the release of ammonia in case of an accidental leak or rupture of the line, an emergency shut down will take place resulting in isolation of the line into 3 sections.
5.6.6 Water Supply and Treatment
Water Corporation’s Desalination and Seawater Supplies Project
In order to service the needs of industrial facilities on the Burrup Peninsula, the Water Corporation constructed a Desalination and Seawater Supply Facility. This facility supplies seawater (capacity of 280 ML/d) and desalinated water (4 ML/d), as well as providing a brine discharge line, which includes disposal of treated industrial and domestic wastewater (208 ML/d) for local strategic industries in the King Bay ‐ Hearson Cove Industrial Area. The Water Corporation facility was issued with WA Ministerial approval in June 2002 (Statement No. 594), with the license conditions outlining specific wastewater criteria to be achieved by the Water Corporation prior to discharge of brine into King Bay (see Annex F for Water Corporation conditions). The commitments also state that wastewater will only be accepted from industries under the License and Ministerial Conditions for those industries.
The Water Corporation as owners and managers of the brine and wastewater discharge system monitor and report on the individual effluent streams entering, and the combined discharge leaving, the system. The Water Corporation has committed to implement (and is implementing) an Environmental Management Program that includes appropriate monitoring and reporting, encompassing water, sediment and biota, for the wastewater system and the ambient environment. The Water Corporation has also committed to impose contractual obligations on system users (which will include BNPL) with respect to the flow and composition of their discharge into the multiuser discharge system. The Water Corporation also independently sample and analyse the individual discharges on a regular basis to validate the accuracy of the data provided by system users.
Sea Water Supply and Cooling Tower
Sea water will be supplied by the Water Corporation and shall be used solely as make up water for the sea water closed loop cooling towers to be installed on the premises of the TANPF. About 450 m3/h shall be imported and a blow down of 350 m3/h shall be exported back to the Water Corporation in accordance with approved Ministerial and licence conditions for release of water to the Water Corporation return line. The cooling towers will also comply with the Health (Air Handling and Warm Water Systems) Regulations 1994.
Desalination Water and Potable Water Supply
Potable water shall be provided directly by the Water Corporation, with desalinated water to be provided by BFPL. A total of 2 m3/h of potable water will be supplied from the Water Corporation. Desalinated water will be used for fire fighting and utility stations and for the closed loop fresh water cooling system. An adequate volume for fire fighting water is foreseen. Potable water obtained from the Water Corporation will be used for safety showers, utilities and domestic purposes.
Closed Loop Fresh Water Cooling System
The cooling requirements of the process elements within the TANPF will partially be provided by a closed loop fresh water cooling system. Process heat exchangers requiring cooling water will normally be fed from this system, with 6,545 m3/h of fresh water to be within the loop system with the exception of the steam condenser in the NA plant. The hot fresh water will be cooled with seawater from the cooling towers. The steam condenser of the NA plant shall be fed directly from the seawater loop system. The heat from the TANPF process operations is taken out through the use of the cooling system by evaporation of about 100 m3/h of seawater in the cooling towers.
35 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
Water Ponds
A clean surface water pond and a contaminated surface water pond will be utilised at the facility to manage the various liquid streams. The clean surface water pond will store rainwater collected from roofs and parking areas as well as clean condensates. About 24.6 ML/y of water from the clean surface water pond will be transferred to the Water Corporation facility. The water will be analysed prior to discharge from the BNPL facility to ensure it complies with approved Ministerial and licence conditions of the Water Corporation. Contaminated water (eg. miscellaneous drips/drains/floor and equipment washings) will be neutralised and collected in a contaminated surface water pond for evaporation. This is a closed system (eg. no liquid will be discharged), with the solid salts/ sludge created by evaporation to be treated and handled as special waste in accordance with all relevant statutory requirements. This waste will be sent offsite for disposal at an appropriate facility by an approved and licensed waste contractor. The contaminated surface water pond will be divided into two sections so that one section can remain in operation while the other is being cleaned of residual salts. The pond is sized to be able to cope (evaporate) with the normal flow of wastewater from the TANPF estimated to be about 9,735 t/year and additional flows in connection with tropical cyclones. The water ponds will be located at an altitude above sea level sufficient to secure against ingress of flood waters or storm surge. The ponds will comply with Department of Water requirements for constructing contaminated surface water ponds, and the need for measures to deter birds from these ponds will be investigated.
Drainage
Drainage design cannot be finalised until the project is at the detailed design stage. At this stage, consultation on drainage design will be undertaken with DEC. However, the overarching principles are known and a preliminary plan is shown in Annex F. Natural drainage on the Site will be diverted to ensure that flows continue into the salt flats. BNPL will consult with DEC over drainage design to ensure that there is a minimal impact on natural flows. Wastewater and rain water will be collected on site, and will be segregated to drain to either the clean or contaminated surface water pond (as discussed above). Water quality will be controlled and monitored using conductivity and pH measurements, and water will be routed to the appropriate pond. Water from the clean surface water pond which does not exceed the Water Corporation’s agreed Ministerial limits will be sent to the Water Corporation.
The TANPF shall comprise a network of bunded areas and trenches so that any potentially contaminated water is kept completely isolated from rainwater. All storage tanks and all main plant units will be bunded. Bunded areas within the complex shall in most cases include a collecting pit from which wastewater is sent to the contaminated surface water pond. Some bunded areas that may contain special components (coating agent for example) shall be emptied using trucks and drained content shall be treated as special waste. These wastes will not be connected to the contaminated surface water pond. Clean surface water, such as rainwater, shall be collected through a separate trench and gutter network and sent to the clean surface water pond.
Wastewater Streams
A total of 3,105 ML/y of water (including sea water blow down and clean surface water) will be sent to the Water Corporation in compliance with the Water Corporation Ministerial conditions. This level of discharge will be well within the Water Corporation discharge line capacity of 208 ML per day, with the current use of the discharge line being less than 50% capacity (pers comm. Brett Jago, 2009). All contaminated streams (waste) shall be sent to the contaminated surface water pond. For example, purge streams from ammonia heat exchangers shall be collected in barrels. These barrels are either treated (neutralised) when possible or removed as special waste; trace amounts may be sent to the contaminated surface water pond. There may also be exceptional drainage of bunded areas containing water that is possibly contaminated by special substances. These shall be treated as special waste. All wastewater disposals will comply with the Health (Treatment of Sewage and Disposal of Effluent and Liquid Waste) Regulations 1974. At this stage there are no plans for the use of any recycled water, however, if this is required this will be carried out in accordance with the National Water Quality Management Strategy Australian Guidelines for Water Recycling: Managing Health and Environmental Risks (Phase 1) 2006.
5.6.7 Power Generation Treatment
Power Generation and Emergency Power
Approximately 8.5 MW of power will be required to run the TANPF. About 5 MW of the total 8.5 MW requirement for the TANPF will be imported from BFPL, which produces power from the use of Natural Gas. The remaining power (approx 3.5 MW) will be generated by excess steam from the operation of the NA plant.
36 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
Once operating, the synthesis of nitric acid gives off significant waste heat that will be transferred to a steam system. Some of this steam will be used in the process units of the TANPF (for example air heaters), with the remaining excess heat to be sent through to a high efficiency turbine to generate electrical power through the use of steam. This allows for a significant decrease in the energy required to operate the TANPF and thereby significantly reduces the air emissions and greenhouse gases produced. In case of a power outage, emergency power (for lighting and safe plant shut down) will be provided by on‐site diesel generators.
Steam Grid
In normal operation, the TANPF will have its own independent steam grid comprising several levels of pressure (ranging from 46 to 6.5 bar). This steam will be produced from the operation of the NA plant. Due to the self‐sufficient nature of the NA plant steam process, the TANPF will require steam imports from BFPL to help pre‐heat certain units and feed the steam turbines during start up of the NA plant. Start‐up of the NA plant will require an external steam supply from BFPL with a peak demand of 40 t/h of steam at 46 bar pressure and 388°C temperature.
5.6.8 Instrument and Plant Air System
Three electric driven compressors, each designed for 50% of maximum air consumption, will provide compressed air that will be dried and used for instrument and general work (tools etc). The capacity of each compressor will be about 1,000 Nm3/h.
5.6.9 Support Facilities
Support facilities that will be required for the TANPF are shown on Figure 5.4 and include:
• Administration office and staff amenities.
• Chemical /raw material store – The chemical/raw material store will be used to store given quantities of raw material and chemicals to allow for about 1.5 months of normal consumption (see Section 5.6.5 for further details).
• Spare parts store ‐ The spare part store will be used to store sets of replacement parts for machinery or full machines/devices that are deemed critical for the operation of the TANPF. The spare part store may also contain day‐to‐day maintenance consumables.
• Workshop ‐ Existing facilities at the BFPL plant will be used. The workshop will be used for day to day maintenance activities and will contain all the tools and lifting devices necessary to perform maintenance tasks.
• Central control room ‐ The control room will be used as a central control centre where the technical operation of the TANPF will be managed. The control room will be blast, fire and weatherproof. The control room will consist of a fully distributed and advanced control system to ensure the safe operation and management of the TANPF. The control room will be manned by at least one person at all times.
• Field laboratory ‐ The laboratory within the TANPF will be used to analyse product/samples from the process units and for storage so that product quality and safe operation can be monitored. A main laboratory, located at the existing facility at BFPL will be used for most analysis.
• Safety, First Aid and Fire Station building – The safety and First Aid facilities will be used to host emergency medical and safety equipment/gear so that First Aid can be provided on the premises of the TANPF. The Fire Station will host the fire‐fighting brigade that shall be specially trained and equipped for the specific hazards of the TANPF. These services for fire will be provided by the existing services located at BFPL which will be retro fitted if required to meet all requirements of the TANPF.
• Gatehouse ‐ A gatehouse will be provided at the entrance to the Site for the purposes of security.
Transport, Roads and Parking
Site access for the TANPF Project will be via Village Road, an existing two lane bitumen access road constructed to service the already operational BFPL ammonia plant (Figure 1.1). Transport of TAN (bulk and bagged product) to local and regional customers will predominately be via the existing local road network. A connecting internal road from the TANPF to the existing Village Road, north of the Site will be constructed as part of the project. From Village Road products will be transported to local customers via Burrup Road and the Karratha‐Dampier Highway. Truck loading will use a system consisting of front loaders, bucket elevators and silos in combination with a truck weighing system. Approximately 25 trucks will operate per day for bulk, bagged and solution products. BNPL will have in place a parking area for use by transporters on the Site, as well as offices (3 staff), workshop (3 mechanics) and a parking/truck wash (with all runoff water to be directed to the clean and/or contaminated surface water ponds). The area is foreseen to be adequate for parking of a fleet of about 20 road trains.
Accommodation Facility
Work force employed during construction will be accommodated in either existing or new camps in Karratha or Dampier, depending on availability. No accommodation will be in place on the Burrup Peninsula as a result of this project.
37 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
Permanent housing for operational workforce will be built or acquired in the Karratha region (for about 60 Karratha based persons in total).
Sewage
Sanitary waste will be collected by authorised personnel using trucks and transported to an off‐site treatment plant. The amount of sanitary waste is estimated to be a maximum 0.2 m3/person/day. During the construction an average of 400 persons will be on site with a peak of 650 persons. When the TANPF is in normal operation a total of 60 persons will be employed (including shift personnel). Sanitary waste storage, collection and disposal will be organised sufficiently for the number of personnel on‐site in accordance with all relevant legislative requirements, including those of the WA Department of Health (DoH).
Lighting
The provision and use of artificial lighting are required for safety and operational reasons as the TANPF will operate on a 24 hour, seven days a week basis. Artificial sources of light will be used during the construction and operations phases of the TANPF as follows:
• Lighting to enable 24‐hour a day activities at the TANPF.
• Lighting within the construction site, should night‐time works be required.
The permanent lighting system for the TANPF will be determined in the detailed design phase for the TANPF. Permanent artificial lighting will be reduced to the least practicable level for the safe conduct of operations, with design considerations including:
• Need for the light;
• Timing requirement for the light, such as timers to extinguish lights;
• Shielding to limit light spill to within the Site (where possible);
• Light positioning, such as reducing height and using screening;
• Orientation of lights away from Hearson Cove (where possible); and
• Reducing wattages.
5.7 Project Life Cycle
5.7.1 Construction
Construction of the TANPF will take approximately 30 months with the workforce level likely to vary over the entire period. During peak periods, approximately 650 persons will be on site while the mean construction workforce is expected to be approximately 400 persons. These numbers include all categories of construction workforce personnel. Construction activities will be conducted during normal project working hours with the potential for some out of hours activities.
Site Preparation and Earth Works
The proposed site preparation works for TANPF will include (but not necessarily be limited to):
• Removing vegetation within the designated area;
• Preparing the plant footprint including laydown and stockpile areas;
• Dewatering and trenching (as required);
• Establishing water facilities – including construction potable water and wastewater treatment plant;
• Site drainage;
• Establishing perimeter fencing; and,
• Road and access tracks for construction.
Civil Works
The proposed civil works for TANPF will include:
• Excavation for foundations and other civil works (eg. footings);
• Controlled blasting (if required);
• Laying of concrete pad/footings – including curing of the concrete (water requirement);
• Equipment Storage/construction laydown; and
• Preparation of ammonia pipeline and utilities from BFPL. Should blasting be required, this will be controlled, low impact blasting, so as to manage potential risks associated with the adjacent BFPL facility, located immediately to the west. Due to the sensitivity to vibrations of the heavy rotating machinery, for example compressors and turbines, operating at the BFPL plant, blasting must be performed in a very controlled manner to avoid tripping of the ammonia plant. Therefore, the use of explosives will be avoided or limited to the absolute minimum, and if used blasting will be carried out in a very controlled manner. Controlled blasting is normally performed with a number of low intensity charges, which are initiated in a sequence.
38 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
Plant Installation
The proposed activities associated with plant installation for TANPF will include:
• Transport of construction materials on and off‐site (via Karratha‐Dampier Rd, Burrup Rd and Village Rd) – including cranes;
• Operation of cranes;
• Grinding and welding;
• Insulation and painting;
• Non‐destructive testing (incorporating x‐ray tests of welds);
• Joining cooling water lines (resins, glass fibre); and
• Landing of prefabricated Components. The landing of components for the plant can be undertaken via the Dampier Public Wharf or Mermaid Marine’s Wharf. The Dampier Public Wharf currently has a maximum capacity of 300 T. Alternatively Mermaid Marine’s Wharf has a larger capacity of 2,000 T which is well within the capability of accepting all necessary components for the TANPF. Use of either of the facilities for the landing of plant components will be negotiated under a commercial agreement between BNPL and Mermaid Marine or the Dampier Port Authority.
General
Proposed general activities associated with the construction of the TANPF will include:
• Workers commuting to site (using buses to transport all personnel to and from the Site);
• Use of existing roads, power, water, sewage and waste disposal facilities.
• Preparation of on‐site worker facilities (crib rooms etc.);
• Vehicle movements for construction and installation of plant equipment;
• Off‐site construction workforce camp (in Karratha or Dampier);
• Fuel storage; and
• Refuelling of vehicles and machinery.
5.7.2 Emissions, Discharges and Waste during Construction
Atmospheric Emissions
Construction activities associated with earthworks and vehicular movement are likely to result in a temporary increase in atmospheric emissions across the Site. Emissions will result from the use of heavy machinery and plant equipment, the running of generators and increased use of vehicles required for construction workforce transport.
Dust emissions are expected to be greatest during the construction phase and are likely to vary depending on the construction activity and the prevailing wind conditions. Earthworks for the TANPF, area for surface water ponds, and trenching and filling are all likely to result in increased dust levels. Construction will also see an increase in vehicle movements over unpaved roads and access tracks within the Site, which will add to dust creation during construction.
Solid NonHazardous Waste
Solid non‐hazardous waste shall mainly be composed of general refuse such as building rubbish (including metal, plaster board etc.) and packaging material. All wastes will be segregated and disposed of accordingly depending on the types of waste.
Liquid Waste
No significant amounts of liquid waste are expected during construction apart from potential water resulting from dewatering which is expected to be very limited (if required).
5.7.3 Commissioning
Commissioning is scheduled to take six months and will start three months prior to mechanical completion of the TANPF. To assist the contractor (who will have overall responsibility for commissioning) with commissioning, suppliers of the main equipment will be invited to have an involvement in commissioning of the TANPF. Also, all plant operators will take part in the commissioning phase as a form of advance training.
Leak Testing
Leak testing utilising air or water is likely to be performed on all elements required to be leak‐free in the TANPF process units. Any contaminated materials will be sent offsite to licensed contractors for treatment and disposal.
Pressure Testing
Pressure testing shall be performed on all elements required to be pressure certified or expected to operate in pressurised conditions in the TANPF. Testing of elements that require certification shall follow the relevant procedure according to applicable regulations and codes.
Commissioning of TANPF
Commissioning shall involve the testing of all systems within the TANPF independently or in a given combination including control systems, electrical and all process units. Process units shall either be tested with water or with the actual fluid for operation.
39 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
All units may require cleaning prior to actual testing. All waste developed from cleaning process will be collected and disposed off appropriately in accordance with relevant legislation and the waste management plan within the CEMP.
5.7.4 Emissions, Discharges and Waste during Commissioning
Atmospheric Emissions
During blowing out of the nitric acid plant (cleaning with air) air with small amounts of dust and sand will be emitted to atmosphere. More generally, all pipe work is likely to be blown clean by air before being leak or pressure tested. Although some sections may require cleaning with solvents that can evaporate, it is not foreseen that significant amounts of solvents shall be used.
Solid Waste
During commissioning a number of systems may be operated outside normal operating conditions that may result in the need to replace consumable parts of the systems more frequently than during nominal operation. For example the oil unit of the turbo set in the NA plant will be cleaned by circulating oil through the oil filter. The cartridges of the oil filter will be changed when these filters are spent. The spent cartridges are non hazardous wastes and will be disposed of appropriately in accordance with relevant legislation and the waste management plan within the CEMP.
Liquid Waste
Some flow lines within the TANPF will be cleaned with water or water with chemicals. For example, the process gas cooler system of the NA plant will be boiled out with water and some chemicals. In most cases the spent water will be sent accordingly to either the contaminated or clean surface water ponds. If spent water contains a significant amount of special compounds (oil for example) it shall be treated as special waste, the procedure for which shall be clearly stated in the waste management plan prior to commissioning. The water used for leak testing and/or pressure testing will also be sent to either the contaminated or clean surface water ponds. Any contaminated materials will be sent offsite to licensed contractors for treatment and disposal as required. Some machinery may require exceptional oil purging during commissioning. The resulting liquid waste shall be treated accordingly. Procedure shall be clearly stated in the waste management plan prior to commissioning.
Sanitary wastewater shall be collected by truck for treatment as described in Section 5.6.9.
5.7.5 Operations
Although it is likely to operate for a much longer period, the TANPF will be designed for a minimum lifetime of 20 years. It will have an annual uptime of 90% minus the provision of any downtime due to market reasons or other reasons that are not related to plant operations. An inter‐stage NA storage tank will allow the NA plant and the AN solution and TAN plants to operate independently for up to two days. This is deemed to be adequate in terms of time, for plant maintenance (e.g. catalyst change in NA plant, necessary cleaning in the TAN plant etc.). When the NA plant is shutdown, the necessary steam and power to maintain the AN/TAN production will be provided by BFPL. The operation will require 60 full time (direct) personnel. Certain positions will be outsourced (eg. in bagging, maintenance, transport) and are not included in this figure.
Production (Operations) Phase
In the normal production phase all units in the TANPF will operate at a steady rate that is close to the nominal production rate or at least within the minimum safe operating parameters as per the design. This will be:
• 760 MTPD for the NA plant;
• 965 MTPD for the AN solution plant; and
• 915 MTPD for the TAN prilling plant. Truck loading and bagging of TAN will be operated to match production levels. Normal operation may also include normal maintenance on systems, which include redundancy (for example pumps 1 out of 2).
Start Up, Shut Down, Upset Conditions
Scheduled shutdowns may result from the need for extra‐ordinary repairing, market situation (no demand), routine maintenance or a combination of factors. Typically, scheduled shutdowns shall follow a given and safe procedure so as to minimise the amount of unrecoverable product within the system, as well as minimise the creation of higher emission levels associated with shutdown procedures (see Table 5.10, Table 5.11 and Table 5.12). Unscheduled shutdowns, though rare, may result from the malfunction of any given critical system within the units of the TANPF. Malfunction is identified as either the physical inability of the system to perform the required task or unsafe operation. In either case the relevant units shut down automatically according to a predetermined safe sequence.
40 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
Upset conditions may result from some perturbation to the system that prevents the TANPF from stabilising in nominal and steady conditions. Upset conditions may require special attention and additional personnel (such as laboratory personnel) so that steady operation can be reached again. Start ups will always follow a given procedure and sequence that are designed to bring the TANPF to nominal operation status within a given timeframe, in a safe manner and with minimised emissions and impacts on the environment. All shutdown, upset and start‐up conditions will be carefully monitored by BNPL staff trained in accordance with strict operating procedures set out in TOPS and the Operations Environmental Management Plan (OEMP).
Workforce and Hours of Operation
The TANPF will operate 24 hours per day, seven days a week. It is anticipated that the on‐site workforce will comprise 60 people, inclusive of six to eight administration staff who will be present during standard daytime working hours. There will typically be two shifts, with shifts to nominally be between 7 am to 7 pm and 7 pm to 7 am. This start‐finish timing, along with all staff being bussed in and out of the TANPF will help avoid potential cumulative impacts on traffic on the congested roads around Karratha and Dampier at peak times.
Routine Maintenance
Every year the TANPF will be stopped for preventive maintenance for approximately one week. Additionally, every half year the NA plant will be stopped for a change of the Pt/Rh catalyst. Lighter maintenance work may also be performed during scheduled or unscheduled stops of shorter time (for example air filter changes, cleaning of dryer drums etc.).
Transport of TAN
See Section 5.6.5.
5.7.6 Emissions, Discharges and Waste during Operation
The TANPF will be designed to meet statutory requirements for all emissions as a minimum. A wastewater treatment facility will be operating on site to treat all wastewater produced by the TANPF. Contaminated wastewater will be evaporated in a contaminated surface water pond, with sludge removed by licensed contractors (as discussed above). Clean water shall be exported back to the Water Corporation via a pipeline in accordance with approved Ministerial and licence conditions for release of water to the Water Corporation return line (as discussed above).
Atmospheric Emissions
For the NA plant, Nitrous Oxide (N2O) and Oxides of Nitrogen (NOx) will be continuously emitted to the atmosphere. The former will be controlled via gas mixing and distribution to the catalytic gauzes, proper raw material filtering, with further abatement by catalytic decomposition in the reactor, while the latter will be controlled via a high pressure absorption design, use of chilled water in the tower and abatement of the tail gas from the catalytic reactor. N2O emissions will be less that 100 ppm while NOx emissions will be below 75 ppm. In addition to continuous emissions, fugitive emissions of NOx are also expected to occur during filling of nitric acid storage tanks and plant shutdown (venting). Fugitive emissions of NOx during filling are expected to be very low, and will produce a maximum of approximately 0.04 g/s (1.5 kg/day) of NOx. Tanks will only breathe NOx during daytime, with zero emissions at night. These emission sources have been included in the dispersion model, conservatively as venting 0.04 g/s for all hours of the day for each tank vent. For the AN plant continuous emissions will be emitted from one single stack into which a common scrubber will exhaust all air used from the plant. The use of BAT shall be reflected in the exhaust air quality (<30 mg/Nm3 particulate and <50 mg/Nm3 ammonia as per EFMA Best Available Techniques 2000).
Solid Waste
Any spills of organic additives or coating agent from the off spec treatment unit that is expected to contain significant amounts of TAN shall be recovered and treated as special waste. The waste management plan (to be completed prior to operation and included in the OEMP) shall describe procedures for management of hazardous waste in detail. More generally speaking, other liquid or solid wastes that may result in a mixture of TAN and organic compounds shall always be treated as special waste. For the NA plant catalysts will be collected and returned to the catalyst manufacturer. Spent filter elements (air etc.) will be collected as solid non‐hazardous, if deemed non‐hazardous. More generally speaking, normal operation, routine maintenance and replacement of consumables such as filter elements, pump seals, gaskets etc. will generate solid non‐hazardous waste. There will also be solid salts resulting from the operation of the contaminated surface water pond. These salts shall be collected and disposed as per legislative requirements. Procedures for management of non‐hazardous waste will be clearly documented in the waste management plan (to be incorporated into the OEMP).
41 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
Liquid Waste
The only liquid waste sources resulting from the TANPF process during normal operation are:
• Oil residue and sludge from the heat exchangers and storage tanks will be recovered and treated as special waste.
• Sea water blow down of 350 m3/h shall be exported back to the Water Corporation in compliance with the Water Corporation’s approved Ministerial conditions for release of water to King Bay.
• Water collected in the clean surface water pond shall be controlled for pollution and once water is deemed of acceptable quality, it shall be transferred to the Water Corporation for further treatment.
• Spent oil from machinery shall normally be sent out to be treated as non‐hazardous waste.
• Blow down and draining of equipment and miscellaneous washings that may contain nitrogen will be sent to the contaminated surface water pond.
• Liquid waste from the laboratory may contain special chemicals that shall be treated as special waste (hazardous or non‐hazardous depending on the exact nature of the chemicals).
• Sanitary wastewaters shall be collected by truck for treatment, as detailed in Section 5.6.9.
5.7.7 Decommissioning
Decommissioning activities will involve the recovery of catalyst (platinum) from the heat exchangers and vessels in the NA plant. The decommissioning phase will last approximately four to six months with an average manning level of 20 personnel. Upon decommissioning, the TANPF is not considered likely to have any significant hazardous wastes or contaminated lands. All left over wastes and contaminated material will be cleaned and removed in accordance with relevant legislation and a Decommissioning Environmental Management Plan (DEMP) to be developed prior to decommissioning. Where appropriate, potential impacts from decommissioning have been discussed in Section 8. Specific abandoning and decommissioning requirements will be formulated and discussed with the relevant state and federal regulatory authorities at the time of decommissioning. Decommissioning, including the DEMP, will be conducted in line with the standards of the day.
Removal of Plant Equipment
Plant equipment and piping will be dismantled and removed and the metal recycled.
Rehabilitation of Site
The Site will be brought back to a level of an industrial zoned area. Prior to decommissioning, a Decommissioning and Final Rehabilitation Plan will be developed. This will specify control measures which will be used to guide the management of water resources, landforms, revegetation and infrastructure and support facilities during decommissioning. If a contamination issue is identified before or during the closure of the TANPF, specific closure actions will be included in the plan. In addition, equipment, buildings and other facilities will be removed. Surface water ponds will be emptied and cleaned (with any contaminated waste to be appropriately removed by an approved waste contractor). Interconnections (piping) to the BFPL site will be removed.
5.7.8 Emissions, Discharges and Waste during Decommissioning
Atmospheric Emissions
Some dust may be generated during decommissioning due to removal of concrete constructions and levelling of the ground.
Solid Waste
Potential solid waste materials that may be created during decommissioning of the TANPF are (but not limited to):
• Insulation;
• Cabling (copper will be recovered);
• Piping (to be recycled);
• Equipment (to be recycled);
• Concrete;
• Asphalt;
• Rubber (belt conveyors);
• Gaskets;
• Prill tower skirts (fabric); and
• Glass from windows. Some instruments may contain radioactive substances and spent catalysts and other accumulated substances and these will be handled in accordance with relevant legislation and BNPL’s waste management plan incorporated in the DEMP.
Liquid Waste
Potential solid non‐hazardous waste materials that may be created during decommissioning of the TANPF are (but not limited to):
• Oil (from turbo set); and
• Sludge (from cleaning).
42 ‐ B U R R U P N I T R A T E S P T Y L T D ‐ Technical Ammonium Nitrate Production Facility Public Environmental Review – January 2010
This page intentionally blank