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Chapter 7. Green Chemistry

((((綠色化學綠色化學綠色化學綠色化學))))

潔淨生產技術潔淨生產技術潔淨生產技術潔淨生產技術 陳奕宏老師陳奕宏老師陳奕宏老師陳奕宏老師

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Content

� 7.1 Green Chemistry 3

� 7.2 Green Chemistry Methodologies 5

� 7.2.1 Feedstocks 5

� 7.2.2 Solvents 9

� 7.2.3 Synthesis Pathways 13

� 7.2.4 Functional Group Approaches to Green Chemistry 20

� 7.3 Quantitative/Optimization-Based Frameworks for the

Design Chemical Synthesis Pathways 22

� 7.4 Green Chemistry System Case Studies 27

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7.1 Green Chemistry

� Ideal chemical reactions would have attributes such

as ︰

�Simplicity

�Safety

�High yield and selectivity

�Energy efficiency

�Use of renewable and recyclable reagents and raw materials

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�Definition︰

The design of chemical products and processes that

reduce or eliminate the use and generation of

hazardous substances.

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7.2 Green Chemistry Methodologies

� The most significant factor in determining the impact of

a chemical manufacturing process on the environment︰

�Environmental persistance

�Bioaccumulation

�Ecotoxicity

�Human toxicity

7.2.1 Feedstocks

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� Innocuous

� Generates Less Waste

� Selective

� Efficient

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7.2.2 Solvents

� Less Hazardous

� Human Health

� Environment (Local and Global)

� Case Studies

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7.2.3 Synthesis Pathways

� Qualitative︰

�Addition reaction

�Substitution reaction

�Elimination reaction

� Semi-qualitative ︰

�Atom efficiency

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Example 7.2-1

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7.2.4 Functional Group Approaches to

Green Chemistry

� Structure-Activity Relationship

� Elimination of Functional Group

� Reduce Bioavailability

� Design for Innocuous Fate

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7.3 Quantitative/Optimization-Based

Frameworks for the Design Chemical

Synthesis Pathways

� Combinatorial approach

� Buxton et al (1997) have reported a number of rules

and guidelines that can be effective in selecting a group

of starting materials.

� Include the groups present in the product

� Include groups present in any existing industrial raw

materials, coproducts or byproducts.

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� Provide the basic building blocks for the functionalities of

the product or of similar functionalities

� Associated with the general chemical pathway employed

� Reject groups that violate property restrictions

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7.4 Green Chemistry System Case Studies

� Green Chemistry Expert System (GCES)