GREEN CHEMISTRY

Green Chemistry

Green Chemistry

The concept of green chemistry was defined in 1998 by the American chemists Paul Anastas and John C. Warner, belonging to the EPA (Environmental Protection Agency). Green chemistry involves the use of principles to reduce and eliminate the use or generation of substances harmful to the environment, by new chemical processes and synthesis routes. Green chemistry is booming. Encouraged by the increasing scarcity under more or less long-term fossil fuel resources, it has become a priority for research and industry.

It is a chemical philosophy directed towards the design of chemical products and processes involving the reduction or elimination of hazardous chemicals (for materials, people and the environment). Therefore, sustainable chemistry focuses on the reactions and processes taking place in the chemical industry and related industries. It is necessary to distinguish it from the environmental chemistry, studying the behavior of chemical compounds (natural or synthetic) into the environment. Note also, that Green Chemistry has a preventive nature (avoiding, as far as possible the generation of hazardous substances), while the environmental remediation is directed towards the elimination of harmful products that have already been discharged to the nature (Constable, 2011).

The 12 Principles of Green Chemistry

Prevention: It is better to produce less waste that investment in sanitation or waste disposal.

The atom economy: syntheses must be designed to maximize the incorporation of materials used during the process in the final product.

Where possible, synthetic methods should be designed to create and use substances of low or no toxicity to humans and without environmental consequences.

Chemicals should be designed to fulfill their primary function while minimizing their toxicity.

Where possible, we must eliminate the use of auxiliary substances (solvents, separation agents) or use of harmless substances. Unconventional methods of activation may be used: the use of water as a solvent, use of supercritical fluids, heated by microwave, substituting ionic liquids.

Energy requirements of chemical processes have an impact on the economy and the environment that must be considered and should be minimized. We must develop methods of synthesis under conditions of ambient temperature and pressure.

When technology and financial resources permit, the raw materials used are renewable rather than non-renewable.

Where possible, any deviation from unnecessary synthetic scheme (use of blocking agents, protection / de-protection, temporary modification of physical process / chemical) should be reduced or eliminated.

Catalytic reagents are more effective than stoichiometric reagents. We must encourage the use of catalytic reagents most selective possible.

Chemicals should be designed so as to ...