As seen in the previous chapter, greener chemistry and cleaner technologies constitute a set of choices pertaining to selection and development of production technology in chemical process industry. There are several other industrial sectors wherein cleaner production and waste minimization can be achieved by adopting the so-called “greener choices”.

In this chapter, discussions and examples have been kept at a general plane so that the reader would be able to see the interdisciplinary and cross-sectoral relevance of the greener choices. First, the choice of eco-friendly solvents has been discussed followed by a discussion on eco-friendly reactants. Both these sections, primarily address the choices made by chemical process industry. Analogous choices and dilemmas exist for engineering and the other sectors as well. Finally, a brief discussion on choices of eco-friendly fuels and fuel-cells has also been included.

Choice of Eco-friendly Solvents

In recent years there has been a search for methods to replace the use of organic solvents in the extraction of natural products. The purpose of replacing organic solvents is to reduce pollution generated by organic solvents. One of these methods, studied is the use of superheated water. Under pressure, water is in liquid phase above 100 °C. This water is superheated water, and is less polar than at ambient temperature and has an increased capability of dissolving organic compounds. Under such conditions extraction of natural compounds can be done using the eco-friendly water which can serve as a solvent [Clifford, 2002].