Basic Principles of Green Chemistry

Green chemistry is defined as environmentally benign chemical synthesis. Any synthesis, whether performed in teaching laboratories or industries should create none or minimum by-products which pollute the atmosphere. According to the work carried out by Paul T. Anastas, the following basic principles of green chemistry have been formulated  

It is most advantageous to carry out a synthesis in such a way so that formation of waste (by-products) is minimum or absent. It is especially important because in most of the cases the cost involved in the treatment and disposal of waste adds to the overall production cost. Even the unreacted starting materials (which may or may not be hazardous) form part of the waste. Hence, the next basic principle is important and should carefully be considered as prevention is better than cure applies in this case also. In other words, the formation of the waste (or by-products) should be avoided as far as possible. The waste (or by-products) if discharged (or disposed off) in the atmosphere, sea or land not only causes pollution but also requires expenditure for cleaning-up. 

2 Maximum Incorporation of the Reactants (Starting Materials and Reagents) into the Final Product 

Chemists globally consider that if the yield of a reaction is about 90%, the reaction is good. The percentage yield is calculated by 

The reaction or the synthesis is considered to be green if there is maximum incorporation of the starting materials and reagents in the final product. We should take into account the percentage atom utilisation, which is determined by the equation 

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Clark, J.H. (2005) Basic principles of green chemistry. Innov. Pharm. Technol, 16, 94-97. 

With a total consumption of —90 kt in 2005, tetraacetyl ethylene diamine (TAED) [14] (Figure 16.5) is the most widely used bleach activator. The product fulfills the basic principles of green chemistry [15], as it has maximum atom efficiency both starting materials (ethylene diamine and acetic acid anhydride) are fully incorporated in the molecule. Its low toxicity profile and ready biodegradability reinforce the sustainability claim. The activator is weight-efQcient, as one molecule generates two molecules of peracetic acid. Under European washing conditions at SO-bO C, it has an excellent cost-performance ratio. The kinetic stability of peracetic acid at lower tanperatures, however, limits its use to warm wash applications. 

Paul Anastas and John Warner in their book published in 1998 introduced the concept of green chemistry as a philosophy for the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances. The founders of green chemistry formulated 12 basic principles, the application of which in the practice of chemical engineering is expected to lead to the development of ecofriendly products and processes. The 12 basic principles of green chemistry are discussed below ... 

Synthesis Involving Basic Principles of Green Chemistry Some examples... 

This chapter discusses the fulfillment of the requirements for a green process, together with the importance of the nicotinate vitamin B3. Lonza s contribution to green chemistry is then illustrated by its processes for producing nicotinates. The current niacinamide process running is China employs no fewer than six basic principles of green-sustainable chemistry. 

Vegetable oil-based polymers are one of the most useful polymeric materials in the context of advanced polymers in modern society. They are versatile because of their structural diversity and their ease of modification. Sectors such as agriculture, automotives, biomedical and packaging all require environmentally friendly polymers. In the civilised world of today, materials need to follow the principles of green chemistry with a triple bottom line approach in order to keep the environment clean and useful for future generations. This book therefore aims to blend the basic ideas along with advanced understanding of this important class of polymers. 

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