estudios quimicos segun bsi

Waste Management xxx (2011) xxx–xxx

Contents lists available at ScienceDirect

Waste Management

journal homepage: www.elsevier .com/locate /wasman

The use of commercial and industrial waste in energy recoverysystems – A UK preliminary study

Christopher J. Lupa a,⇑, Lois J. Ricketts b, Andy Sweetman a, Ben M.J. Herbert b

a Lancaster Environment Centre, University of Lancaster, Lancashire LA1 4YQ, UKb Stopford Energy and Environment, Lancaster Environment Centre, University of Lancaster, Lancashire LA1 4YQ, UK

a r t i c l e i n f o a b s t r a c t

Article history:Received 8 November 2010Accepted 4 April 2011Available online xxxx

0956-053X/$ - see front matter � 2011 Elsevier Ltd. Adoi:10.1016/j.wasman.2011.04.002

⇑ Corresponding author. Tel.: +44 07764926480.E-mail address: [email protected] (C.J. Lupa).

Please cite this article in press as: Lupa, C.J., et aManagement (2011), doi:10.1016/j.wasman.201

With 2020 energy targets set out by the EU fast approaching, the UK is trying to source a higher propor-tion of its energy from renewable resources. Coupled with this, a growing population and increasingtrends in consumer demand have resulted in national waste loads increasing. A possible solution to bothissues is energy-from-waste (EfW) technologies. Many studies have focused on municipal solid waste(MSW) as a potential feedstock, but appear to overlook the potential benefits of commercial and indus-trial waste (C&IW). In this study, samples of C&IW were collected from three North West waste manage-ment companies and Lancaster University campus. The samples were tested for their gross and netcalorific value, moisture content, ash content, volatile matter, and also elemental composition to deter-mine their suitability in EfW systems. Intra-sample analysis showed there to be little variation betweensamples with the exception two samples, from waste management site 3, which showed extensive var-iation with regards to net calorific value, ash content, and elemental analysis. Comparisons with knownfuel types revealed similarities between the sampled C&IW, MSW, and refuse derived fuel (RDF) therebyjustifying its potential for use in EfW systems. Mean net calorific value (NCV) was calculated as 9.47 MJ/kg and concentrations of sulphur, nitrogen, and chlorine were found to be below 2%. Potential electricaloutput was calculated using the NCV of the sampled C&IW coupled with four differing energy generationtechnologies. Using a conventional incinerator with steam cycle, total electrical output was calculated as24.9 GWh, based on a plant operating at 100,000 tpa. This value rose to 27.0 GWh when using an inte-grated gasification combined cycle. A final aspect of this study was to deduce the potential total nationalelectrical output if all suitable C&IW were to be used in EfW systems. Using incineration coupled with asteam turbine, this was determined to be 6 TWh, 1.9% of the national demand thereby contributing 6.5%towards the UK’s 2020 renewable electricity target.

� 2011 Elsevier Ltd. All rights reserved.

1. Introduction

There is little doubt that waste management has emerged itselfas a major challenge in modern society. Urbanisation, populationincrease, and higher consumer demand, has put pressure on wastemanagement companies, landfill operators, and local authorities.As a result, many landfill sites are reaching their stated capacities.At present, the UK produces approximately 335 million tonnes ofwaste per annum. Of this, 100 million tonnes results from mineralsextraction, which is not subject to control under the EU WasteFramework Directive (Defra, 2006a). The remaining 225 milliontonnes is predominantly composed of municipal solid waste(MSW, waste derived from domestic/household sources, e.g. food-stuffs and packaging), commercial and industrial waste (C&IW,waste derived from commerce and industry, e.g. packaging, paper,metals, and catering), and Construction and Demolition Waste

ll rights reserved.

l. The use of commercial and ind1.04.002

(C&DW, waste containing insulation, wiring, and rubble). Althoughalternative recovery options are available, a large proportion islandfilled with approximately 100 million tonnes is disposed ofin this way each year (Defra, 2006b). The EU, and its memberstates, is attempting to face this predicament via implementationof strict environmental legislation, in addition to introducing mon-etary incentives for waste diversion (including the RenewablesObligation Order (ROO), discussed in Section 4). Parallel to this,depletion of fossil fuel resources, combined with climate changeand instability in energy prices, has led there to be heightenedinterest in renewable energy generation. Energy-from-waste(EfW), a process that converts waste into energy for use in thermalor electrical applications, has been posed as a possible answer toboth problems. Initial thermal treatment of wastes can be achievedvia several routes including incineration, gasification and pyrolysis.Once the waste has undergone thermal treatment, energy can beproduced via several routes. The heat can be used to convert waterto steam for use in a steam turbine, or the derived synthetic gas(syngas) can be used to generate electricity via energy conversion

ustrial waste in energy recovery systems – A UK preliminary study. Waste

http://dx.doi.org/10.1016/j.wasman.2011.04.002

mailto:[email protected]


http://www.sciencedirect.com/science/journal/0956053X

http://www.elsevier.com/locate/wasman


Table 1NW C&IW samples. ‘‘Recyclates removed’’ refers to those manually sorted beforesampling whereas ‘‘Residual’’ refers to sorting conducted by the site operator. ‘‘New’’and ‘‘Old’’ refer to the amount of time the waste was left to decompose prior tocollection. In this case, ‘Old’ was approximately 2 weeks.

Sample Site Condition

1 Lancaster University Recyclates removed2 Waste Management Site 1 Recyclates removed3 Waste Management Site 1 Residual4 Waste Management Site 2 Recyclates removed5 Waste Management Site 3 New – pre-sorted and shredded6 Waste Management Site 3 Old – pre-sorted and shredded

2 C.J. Lupa et al. / Waste Management xxx (2011) xxx–xxx

technologies (e.g. gas engine). However, not all wastes can be usedin EfW technologies. In order to achieve good process dynamicsand a favourable economic return, the feedstock must be of certainstandard to gain suitability for EfW processes. For example, anideal feedstock should be of high calorific value (CV, largely relatedto organic content), low moisture, and low inorganic content. Fur-thermore, elemental composition should be low with respect tosulphur, nitrogen, and chlorine as they can preclude thermal con-version and produce undesirable products (detailed in Section 3.2).As a result, C&DW, which makes up 32% of the UK’s total wastearisings (Defra, 2006a), is not suitable for EfW processes due toits low CV and high inorganic content. The two key waste streamsthat are suitable, however, are MSW, and C&IW. National wastearisings show that MSW and C&IW are not the largest contributingstreams (9% and 25%, respectively) (Defra, 2006a), but appear to re-ceive a disproportionate amount of attention and legislation, lar-gely as a result of their recovery potential.

As a result of its high organic content, and therefore CV, manystudies have focused on MSW for EfW processes (Baggio et al.,2008; Lawrence, 1998; Nakamura et al., 2010; Psomopouloset al., 2009). In spite of this, C&IW accounts for a larger proportionof the total annual waste arisings in the UK and is thought to con-tain a comparable organic content. Two major sub categories ofC&IW, which are not too dissimilar from MSW, are Mixed Ordinarywaste (undifferentiated, similar to MSW), and Non-Metallic waste(paper, wood, food, glass, etc.). Although much of the Non-Metalliccomponent will have been removed for recycling, a substantialproportion remains in the residual stream as a result of contamina-tion from liquid residues thereby deeming it unrecoverable. Thesetwo sub categories make up an estimated 43% of UK C&IW arisings,approximately 36 million tonnes (FoE, 2003), and are suitable feed-stocks for EfW applications. Other C&IW sub-categories include;Metallic, Chemical, Mineral, and Healthcare wastes all of whichare not widely accepted as suitable waste streams for EfW.

Previous studies have shown that C&IW is being somewhat ne-glected for use in EfW processes (Envirolink Northwest, 2009). Fur-thermore, lack of characterisation data has meant little is knownabout its true thermal recovery potential. With increasing pres-sures from environmental NGOs and the EU, it is likely thatC&IW will be an important resource for future energy generation.This paper examines North West (NW) UK C&IW samples to deter-mine the suitability of this waste stream in EfW systems. Sampleswere tested for their gross and net CV (GCV and NCV), moisturecontent, ash content, volatile matter, and also underwent elemen-tal analysis. The relevance of the values for EfW will be discussedand potential issues highlighted. The study concludes with a theo-retical based mass balance analysis to determine potential energyoutput generated by the waste if used in EfW systems.

2. Methodology

2.1. Sample collection and preparation

A waste sampling campaign was conducted between Februaryand March of 2010 where C&IW samples were collected from threeNW waste management sites in addition to Lancaster Universitycampus. A sampling strategy was devised according to CEN/TR15310 and adhered to as practically and safely feasible. At eachsite, a thick 3.9 m � 4.9 m polyethylene tarpaulin was used as asurface to separate and mix the waste material. Refuse bags, col-lected from separate locations on-site, were emptied onto the tar-paulin and thoroughly mixed using a two-handed stainless steelspade. Items greater than 10 cm2 were reduced in size using handshears. From this, a 10 kg gross waste sample was obtained afterremoving recyclable products, such as plastics and metals. This

Please cite this article in press as: Lupa, C.J., et al. The use of commercial and indManagement (2011), doi:10.1016/j.wasman.2011.04.002

was done in order to produce an accurate representative samplepost-recycling which would otherwise be performed by a materialsrecovery facility, or the on-site operators. The sample was subse-quently shredded to produce a finer particle size (materials withinsample <5 cm2) using a Fritsch P19 cutting mill. After homogenis-ing the shredded waste sample by thorough mixing, 1 kg subsam-ples were placed into double-bagged polythene bags and stored at20 �C in dry place to maintain sample integrity prior to laboratoryanalysis. A total of six triplicate subsamples were used for analysis(Table 1).

In some instances, two gross samples were taken from the loca-tions to account for differing pre-treatments, or other factors thatcould affect waste characteristics. Ultimately, the waste data wasused to produce an average characterisation of UK C&IW butunderstanding characteristic variability in response to such treat-ments is vital for appreciating parameter interactions.

2.2. Sample analysis

Each waste sample was analysed in triplicate. CV was measuredusing a bomb calorimeter according to the CEN/TS 14918 method.Moisture content was determined in accordance with CEN/TS14774 whereby the sample was dried to 105 ± 2 �C until constantweight. Air atmosphere was changed several times per hour andthe loss of mass was used to calculate moisture content. Ash con-tent was determined using CEN/TS 14775 whereby the sample washeated to 550 ± 10 �C and the inorganic residue measured. Volatilematter in the samples was measured in accordance with CEN/TS15148. Sulphur and chlorine were measured using the CEN/TS15289 method. Carbon, hydrogen, and nitrogen were determinedusing an elemental analyser as stated by CEN/TS 15104. This stan-dard was also applied to determine total organic content (TOC). Fi-nally, oxygen content was determined using desk-basedcalculations.

3. Results

Data was first examined within data sets, and then subse-quently compared against known fuel data obtained from the En-ergy research Centre of the Netherlands (ECN).

3.1. Intra-sample results

The mean and standard deviations based on the triplicate sam-ples for each test are presented in Fig. 1 for each waste sample(note the use of scaling for total sulphur, nitrogen, and chlorine).Note AR is ‘‘as received material’’, Dry is ‘‘dry material’’ and DAFis ‘‘dry, ash-free material’’. The standard deviations show intra-sample variations were minimal with the exception of samples 5and 6. These samples differed from the others as they were col-lected in a pre-treated state (shredded and sorted) and, particularly



Fig. 1. Intra-sample comparisons between waste sample data.

Fig. 2. Mean waste data and standard deviations comparison with other known fuels.

C.J. Lupa et al. / Waste Management xxx (2011) xxx–xxx 3

in the case of sample 6, had undergone partial decomposition. It islikely, therefore, that the observed variability is as result of this.

ANalysis Of VAriance (ANOVA) tests were conducted to identifyany differences between the waste samples. It revealed there to beno significant difference between the samples with respect to GCV,carbon, volatile matter, fixed carbon, hydrogen, and oxygen(p = 0.05). For the remaining parameters, significant differenceswere found. This was particularly pertinent when examining ashdata whereby samples 5 and 6 had a much greater ash contentthan the other samples. Decomposition of these samples wouldhave likely reduced the amount of organic matter thereby increas-ing the total ash content per unit volume of waste. This is also sup-ported by their low NCV.

3.2. Comparative analysis with known fuel types

For the purpose of comparison, data collected from all sites wasaveraged to produce a mean C&IW data set. This was comparedagainst known fuels obtained from the ECN (Fig. 2). These were se-lected as a result of their similar composition and derivation to al-low for purposeful comparison with the waste data set. Refusederived fuel (RDF) is waste that has undergone pre-processing toincrease its combustion favorability, usually performed by amechanical biological treatment plant. This process is largely


mechanical whereby recyclables and compostable materials are re-moved, followed by drying and shredding of the waste to produce acombustible product. As most EfW technologies have been opti-mised for use with MSW, it too was included as a benchmark forC&IW comparison. Furthermore, a technology that uses MSW asa feedstock could potentially use C&IW with minimal adaptation.Pure biomass is also included within the comparison. Anthracitecoal is used as comparative data marker as it is widely used for en-ergy generation. All values were determined using an average ofthe same fuel type. Note some parameters have been removeddue to unavailability of data for some of the stated fuel types.

In most cases, it was observed that the performance of C&IW asa fuel did not differ considerably with the other known fuel types.GCV was calculated as 22.98 MJ/kg, which is comparable to RDFand MSW (24.4 and 18.7 MJ/kg, respectively). Anthracite coal,however, has a GCV 55% greater than that of the mean waste sam-ple. This is to be expected as result of its near 100% organic contentwhich is largely related to CV. The NCV of the waste showed a 59%drop when compared with GCV (9.5 MJ/kg). This is as result of thehigh moisture content within the waste sample. It is necessary toensure the feedstock is as dry as possible prior to thermal conver-sion as dryer fuels obtain higher temperatures and thermal effi-ciencies (Miskam et al., 2009). Moreover, McKendry (2002a,b)suggested a fuel with a moisture content of above 30% would be




difficult to ignite and would reduce the heating value of the resul-tant gas. However, the NCV was still higher than that of MSW(6.4 MJ/kg), a key waste stream for EfW processes (note only oneNCV value was available for MSW). This is further supported by lit-erature values that suggest unsorted MSW has a NCV between 8.5and 9 MJ/kg (Dong and Daji Li, 2003; MacDonald, 2008).

Ash content was calculated as 24.7% but with a large standarddeviation as a result of samples 5 and 6, discussed previously.Ash is the end product of a material after thermal treatment andcomprises of inorganic mineral oxides that form the residual,non-combustible fraction of the material. Ash precludes thermalprocesses, such as gasification, and requires removal to ensurethermal efficiencies are at an optimum level. At high enough tem-peratures, ash forms a liquid ‘slag’ which can increase the risk offeed blockages. It is beneficial, therefore, to use a feedstock thatis of high CV and low ash content. However, since CV is largely re-lated to organic content, it is unlikely that a feedstock with high CVwould have a high ash content.

Volatile matter was high in all fuels apart from coal. No datawas available for biomass pellets but is thought to be comparableto waste (Miskam et al., 2009). Tar formation is proportional to vol-atile matter and so fuels with high volatile content are undesirableas they can cause problems within a thermal conversion system(Miskam et al., 2009). It is therefore necessary to adapt the system(e.g. gasifier) design to ensure tar formation does not inhibit theprocess (Turare, 1997).

Sulphur, nitrogen, and chlorine content was especially low forall fuel types; calculated as 0.43%, 1.3%, and 1.5%, respectively forthe C&IW sample. The issues surrounding sulphur content includesulphur dioxide (SO2) production with subsequent emission to theatmosphere – a precursor for acid rain. However, concerns regard-ing SO2 emissions usually lie with fossil fuels, such as coal, as a re-sult of their higher sulphur contents (0.83%, approximately twicethat of the waste sample). SO2, however, will only form if oxygenis present to allow for oxidation. Under anoxic conditions, usedin gasification for example, sulphur preferentially combines withhydrogen to form hydrogen sulphide (H2S) and minor amounts ofCOS (carbonyl sulphide) (Jazbec et al., 2004). Both require removalfrom the synthesis gas, typically using calcium oxide (Yang andChen, 1979). Similarly, nitrogen forms the basis of nitrogen oxides(NOx) and can too produce atmospheric contaminants such as tro-pospheric ozone (O3) (Jacob, 2000). Chlorine content in the wastesample (1.5%) was comparable to MSW but an order of magnitudegreater than RDF, biomass pellets, and coal. Other literature valueshave suggested lower chlorine contents (Wenchao et al., 2010). In athermal conversion process, chlorine promotes the formation oftoxic chlorinated organic compounds such as dioxins. If, however,low oxygen levels are employed in the process, such as in gasifica-tion, hydrogen chloride (HCl) is formed (McKendry, 2002b) andwill require removal to prevent degradation of mechanical compo-nents. Hydrogen content was higher than that of sulphur, nitrogen,and chlorine (7.2%). Concentrations did not vary considerably com-pared with RDF (8.4%), MSW (5.2%), or biomass pellets (5.7%).However, anthracite coal contains only 3.5%, less than half that

Table 2Potential electrical output using sampled C&IW and typical EfW technologies. Output wasannual Northwest C&IW EfW usage (scenario 2), total annual output if all qualifying wastethe UK is used in EfW (scenario 4).

Technology Mean efficiency (%) Electrical output(scenario 1) (GWh)

Incineration with steam cycle 23 24.9Gasification with gas engine 19 20.5Gasification with CCGT 25 27.0Gasification with co-generation 31 33.5


of the waste sample. Hydrogen is a key component if using the de-rived syngas for energy generation due to its combustion proper-ties. Oxygen content was similar across all fuel types apart fromanthracite coal. As coal is predominantly made up of high-energycarbon–carbon bonds, very little oxygen is to be expected withinits chemical structure. Conversely, in waste derived fuels, lowerenergy carbon–oxygen bonds are present thereby causing the ele-vated oxygen concentrations. Indeed, bond energies are a key fac-tor affecting CV (McKendry, 2002a).

4. Mass balance analysis of C&IW in EfW systems

Although somewhat different in composition, C&IW could beutilised in EfW processes with little retrofitting of current thermalconversion technologies. In this section, these technologies will bediscussed and used to estimate total electrical output using thesampled C&IW. For the purpose of this study, a plant with athroughput of 100,000 tpa was selected and assumptions includingconstant undisturbed 24 h operation and perfect waste homogene-ity were made. As the latent heat of moisture cannot be used effec-tively for thermal conversion, the NCV was used as the foundationof deriving total electrical output. In this study, a mean NCV of9.47 MJ/kg was determined. Mean efficiency data used for massbalance calculations was obtained from Fichtner (2004), wherebyan average of the reported range values for each thermal conver-sion process were used. Assuming no radiant or mechanical loseswithin the combustion chamber, a plant operating at 100,000 tpacould produce 30.01 MW of thermal energy. Without conversion,however, this energy would be lost. This calculation, in additionto those expressed below, have been determined using the NCVof the sampled C&IW, plant feed rate, and plant efficiencies de-tailed in Table 2. Typically, incineration is considered the simplestform of converting waste to energy on the premise that a thermalconversion unit is present, such as boiler and steam turbine. In thisinstance, the waste is combusted in super-stoichiometric oxygenconditions to produce heat that converts water into steam foruse in a turbine. A typical incinerator with steam turbine has acombined efficiency of 23%. However, this figure is an estimationas factors such as turbine design and combustion temperatureswill greatly affect the efficiency of the system. Using a boiler andsteam turbine operating at this efficiency, total annual electricaloutput can be calculated at 24.9 GWh. This, however, is assumingno thermal energy is recovered for heat applications (e.g. districtheating) which would reduce the electrical output but increasethe overall efficiency of the plant. Advantages of using incinerationas part of a thermal recovery process are largely accredited to therobustness of the plant to operate with a vast majority of unpro-cessed, heterogeneous waste derived from differing sources. How-ever, efficiencies of steam turbines are somewhat lower than othertechnologies that are available for energy generation.

Other, more advanced technologies are available for energygeneration from waste. Unlike incineration, many of these do notuse the heat for energy conversion, but use the derived syngas as

calculated on the basis of using a hypothetical, 100,000 tpa plant (scenario 1), currentin the NW is used in EfW (scenario 3), and total annual output if all qualifying C&IW in

Electrical output(scenario 2) (GWh)

Electrical output(scenario 3) (GWh)

Electrical output(scenario 4) (TWh)

12.4 223.6 6.010.3 184.7 4.913.5 243.1 6.416.8 301.4 8.0



C.J. Lupa et al. / Waste Management xxx (2011) xxx–xxx 5

a fuel. Syngas, a mixture of predominately CO and H2, is producedvia the thermal conversion of a solid feedstock to a gas in a processknown as gasification. Since gasification is also a thermal process,there are losses associated with this conversion with most gasifiersachieving an efficiency between 55% and 75% (Fichtner, 2004).This, therefore, will reduce the overall efficiency of the EfW processas losses are incurred at both the gasification stage in addition tothe energy generation stage. Post gasification, the syngas can becombusted using an energy conversion technology such as a gasengine. Several leading companies have been producing gas en-gines for many years. These, however, are manufactured for usewith natural gas (CH4) or biogas. To date, very few have been pro-duced to utilise waste derived syngas. It is expected, however, thatlittle modification will be required to enable such gas engines touse this gas–fuel. Assuming a combined efficiency of 19%, total an-nual electrical output can be calculated as 20.5 GWh. This, how-ever, is less than the calculated output using a traditional steamturbine despite the technology being more advanced. As men-tioned previously, the reason for this discrepancy is that the totalcombined efficiency, when using gasification, is lower that thatof an incinerator and steam cycle. When considering a stand-alonegas engine, efficiencies of �40% (natural gas) can be achieved com-pared with just �30% for a steam turbine. However, as steam tur-bines only require heat for operation, they are more efficient forenergy conversion. From this, it would appear that it is unneces-sary to use a less efficient gasification-gas engine combination.However, there are many benefits associated with using gasifica-tion. This form of thermal treatment reduces the amount of harm-ful gases, such as dioxins, SO2 and NOx, that are emitted to theatmosphere. Moreover, CO2 levels are lowered as carbon and oxy-gen are in the simpler molecular form of CO due to the high tem-peratures employed and sub-stoichiometric oxygen levels (FoE,2009). A new incentive known as the ROO, mentioned previously,has been introduced in the UK to incentivise the deployment of no-vel, renewable energy technologies by awarding power supplycompanies with a Renewables Obligation Certificate (ROC) forevery MWh of renewable energy produced. These have monetaryvalue and, in most cases, the income associated with ROCs will ex-ceed that of the energy sold to the national grid. ROCs will beawarded depending on the calorific value of the syngas. A syngasof calorific value between 2 and 4 MJ/m3 is classed as ‘standardgasification’ and is awarded 1 ROC. A syngas of calorific valuegreater than 4 MJ/m3 is classed as ‘advanced gasification’ and isawarded 2 ROCs. EfW using incineration is not eligible for ROCs un-less the fuel contains greater than 90% biodegradable matter.

Perhaps the most advanced of all EfW systems is combined cy-cle gas turbine (CCGT). This system utilises a gasifier to convert thewaste to syngas that is subsequently fed into a gas turbine forpower generation. The excess heat produced from this process isused to convert water to steam for use in a steam turbine. Parasiticload (total energy consumed by process) of this system is veryhigh, but efficiencies can be as great as 26% when using a typicalgasifier. Once again, the CCGT process itself can yield efficienciesmuch greater than 40%, even on a small scale, but the losses asso-ciated with the gasifier reduces the total efficiency of the conver-sion process. Using an average value of 25% efficiency, totalannual electrical output was calculated as 27.0 GWh.

It is possible to use a mixture of waste and fossil fuel in a pro-cess called ‘co-generation’, or ‘co-firing’. This supplements the en-ergy content of the primary waste feedstock to increase totalelectrical output. However, it is not a process that relies solely on‘dirty’ fossil fuels and so does not have the associated negative im-age. Furthermore, as this process can utilise gasification or pyroly-sis, it can be eligible for ROCs. Using and estimated mean efficiencyof 31% for incineration with steam cycle, total annual electricaloutput was calculated as 33.5 GWh.


A recent study conducted by Envirolink Northwest found thatthe North West region of the UK has the potential to use900,000 tonnes of C&IW in EfW systems. In 2006, however, only50,000 (5%) was utilised in this way. On a national scale, an esti-mated 36 million tonnes of C&IW qualifies for EfW assuming aneligibility figure of 43%. However, it is likely that a portion of thiswill be removed for recycling. Little data is available for C&IWrecycling, however Friends of the Earth (2003) have suggested anational recycling and reuse figure of 34%. This leaves 24 milliontonnes of C&IW available for EfW systems per annum in the UK. In-deed, this is an estimation as the recycling figure applies to totalnational C&IW arisings, not just the EfW eligible portion. However,it is likely that the recycled component of C&IW will be largely de-rived from the eligible waste (i.e. contaminated and chemicalwastes are not recycled). Using incineration coupled with a steamcycle, perhaps the simplest of recovery systems, this would equateto approximately 6 TWh of electrical energy per annum. In 2005,the national grid had a demand of almost 310 TWh meaning a po-tential fossil fuel diversion of 1.9% if all qualifying C&IW were to beused in this way. In order to conform to the EU 2020 directive, theUK government has set a target of generating 30% of all electricityfrom renewable sources by 2020. Therefore, C&IW alone could con-tribute 6.5% to this goal. A summary of the potential electrical out-puts calculated is shown in Table 2.

5. Conclusions

C&IW has the potential to be of great benefit for the future ofrenewable energy generation. MSW is a proven feedstock for usein energy generation systems and analysis of C&IW has shownthere to be similarities between the two waste streams. Further-more, waste arisings data has shown a higher production rate ofC&IW in the UK. It is for these reasons that C&IW must not be over-looked when considering future fuels for energy generation. Fur-thermore, appropriate use of this waste would reduce theamount being sent to landfill with an estimated Northwest diver-sion of 22% if all qualifying C&IW was used in EfW (Envirolink,2009). There are, however, difficulties associated with the useC&IW in EfW systems. MSW, although largely heterogeneous, doesnot vary as greatly as C&IW. There are two predominant C&IW sub-streams that can be used, discussed previously, which may requiresegregation from a gross waste stream depending on the wastemanagement company. In the case of this study, the samples col-lected were from management sites that only dealt with mixed-ordinary C&IW. Furthermore, C&IW is dealt with by privatecompanies whereas MSW is the responsibility of the local author-ities. Issues surrounding the use of waste derived syngas in energyconversion systems remain. Further work should be undertaken tocharacterise the syngas derived from a C&IW stream to determineits suitability in large-scale gas engine, or gas turbine, applications.This will indeed unveil any issues surrounding gas quality and helpdetermine design retrofit, if any, of existing EfW plants.

Acknowledgements

Thanks go to Stopford Energy and Environment, the Engineeringand Physical Sciences Research Council, and the Technology Strat-egy Board who helped fund this project.

References

Baggio, P., Baratieri, M., Gasparella, A., Longo, G.A., 2008. Energy and environmentalanalysis of an innovative system based on municipal solid waste (MSW)pyrolysis and combined cycle. Applied Thermal Engineering 28, 136–144(Elsevier).




British Standards Institute, 2004a. CEN/TS 14774-1:2004 Solid Biofuels.Determination of Moisture Content. Oven Dry Method. Total Moisture.Reference Method. British Standards Institute.

British Standards Institute, 2004b. CEN/TS 14775:2004 Solid Biofuels.Determination of Ash Content. British Standards Institute.

British Standards Institute, 2006a. CEN/TS 15104:2005 Solid Biofuels.Determination of Total Content of Carbon, Hydrogen and Nitrogen.Instrumental Methods. British Standards Institute.

British Standards Institute, 2006b. CEN/TS 1418:2005 Solid Biofuels. Method for theDetermination of Calorific Value. British Standards Institute.

British Standards Institute, 2006c. CEN/TS 15148:2005. Solid Biofuels.Determination of the Content of Volatile Matter. British Standards Institute.

British Standards Institute, 2006d. CEN/TS 15289:2006 Soilid Biofuels.Determination of Total Content of Sulphur and Chlorine. British StandardsInstitute.

British Standards Institute, 2006e. CEN/TR 15310-2:2006 Characterization of Waste.Sampling of Waste Materials. Guidance on Sampling Techniques. BritishStandards Institute.

Defra, 2006a. Estimated Total Annual Waste Arisings, by Sector. [Online] (Updated28th September 2006). Available at: <http://www.defra.gov.uk/evidence/statistics/environment/waste/kf/wrkf02.htm> (accessed 10.03.10).

Defra, 2006b. Key Facts About: Waste and Recycling [Online] (Created 13thFebruary 2006). Available at: <http://www.defra.gov.uk/evidence/statistics/environment/waste/kf/wrkf14.htm> (accessed 10.03.10).

Dong, C., Daji Li, B.J., 2003. Predicting the heating value of MSW with a feed forwardneural network. Waste Management 23, 103–106 (Elsevier).

Energy research Centre of the Netherlands (ECN). Phyllis, the Composition ofBiomass and Waste [Online]. Available at: <http://www.ecn.nl/phyllis>(accessed 15.03.10).

Envirolink Northwest, 2009. Energy from Waste (EfW), Northwest OpportunitiesStudy. British Standards Institute.

Fichtner, 2004. The Viability of Advanced Thermal Treatment of MSW in the UK.Fichtner Consulting Engineers Ltd. Published by Environmental ServicesTraining and Education Trust.


Friends of the Earth, 2003. Commercial and Industrial Waste. British StandardsInstitute.

Friends of the Earth, 2009. Pyrolysis, Gasification and Plasma. British StandardsInstitute.

Jacob, D.J., 2000. Heterogeneous chemistry and tropospheric ozone. AtmosphericEnvironment 34, 2131–2159 (Elsevier).

Jazbec, M., Sendt, K., Haynes, B., 2004. Kinetic and thermodynamic analysis of thefate of sulphur compounds in gasification products. Fuel 83, 2133–2138(Elsevier).

Lawrence, R.A., 1998. Energy from municipal solid waste: a comparison with coalcombustion technology. Progress in Energy and Combustion Science 24, 545–564 (Elsevier).

MacDonald, M., 2008. Review of Plasma Arc Technology. Surrey County Council.British Standards Institute.

McKendry, P., 2002a. Energy production from biomass (part 1): overview ofbiomass. Bioresource Technology 83, 37–46 (Elsevier).

McKendry, P., 2002b. Energy production from biomass (part 3): gasificationtechnologies. Bioresource Technology 83, 55–63 (Elsevier).

Miskam, A., Zainal, Z.A., Yusof, I.M., 2009. Characterization of sawdust residues forcyclone gasifier. Journal of Applied Sciences 12, 2294–2300.

Nakamura, M.R., Castaldi, M.J., Themelis, N.J., 2010. Stochastic and physicalmodeling of motion of municipal solid waste (MSW) particles on a waste-to-energy (WTE) moving grate. International Journal of Thermal Sciences 49, 984–992 (Elsevier).

Psomopoulos, C.S., Bourka, A., Themelis, N.J., 2009. Waste-to-energy: a review of thestatus and benefits in USA. Waste Management 29, 1718–1724 (Elsevier).

Turare, C., 1997. Biomass Gasification Technology and Utilization. Artes Institute,University of Flensburg, Germany.

Wenchao, M.A., Hoffmann, G., Schirmer, M., Chen, G.C., Rotter, V.S., 2010. Chlorinecharacterisation and thermal behaviour in MSW and RDF. Journal of HazardousMaterials 178, 489–498 (Elsevier).

Yang, R.T., Chen, J.M., 1979. Kinetics of desulfurization of hot fuel gas with calciumoxide. Reaction between carbonyl sulfide and calcium oxide. AmericanChemical Society 13 (5), 549–553.


http://www.defra.gov.uk/evidence/statistics/environment/waste/kf/wrkf02.htm




http://www.ecn.nl/phyllis


estudios quimicos segun bsi

Documents