Prevention by recycle at source

World over we are seeing discussions about green and green related issues. Chemical Industry is no exemption. There is a great need to develop and practice eco-friendly processes for manufacturing products avoiding chemical pollution and waste generation. When the chemical products are designed keeping in mind the principles of green chemistry and E-factor, the enormous amount of waste produced by the industry can be kept under control.

The relevance of E-factor should be recognized at the design stage itself for any product so that it comes in harmony with the green concept. E-factor helps develop new processes and chemical products without harming the environment. It stresses on design of safer, biodegradable and less hazardous useful chemical products utilizing atom economic and energy efficient processes.

High Volume Products generate huge quantities of waste like H-Acid, DASDA, Paracetamol, Phenylephrine, Pigment CPC, Violet23 and Pendimethylene, which are extremely deadly harmful to the mankind. The key is prevention, not control. It is important to ensure proper scale-up through appropriate mixing, reactor design and engineering to have uniformity over large-volume operation. This is where green engineering plays a critical role in prevention by recycle at source at industrial scale. Green Chemistry is taking an independent form as an amalgam of other chemical disciplines, especially organic, inorganic and biological chemistry.

 

Vote for E-factor

In the early 1980s, the world’s chemical fraternities’ attention was drawn to DSM Fine Chemicals. No, it’s not because of the sudden surge in the stock market or a new range of products. The phloroglucinol plant at Oce´ Andeno gained much attention because the cost of disposing of the waste was rapidly approaching the selling price of the product and company was forced to close its plant. It was in the wake of this issue that Roger A Sheldon, Professor of Biocatalysis and Organic Chemistry at Delft University of Technology had developed the concept of E-factor in the early 1980s. Interestingly, the concept of green chemistry was being formulated at about the same time by Anastas at the Environmental Protection Agency (EPA) to address the environmental issues of both chemical products and the processes by which they are produced.

Green chemistry efficiently utilises (preferably renewable) raw materials (includes the source of energy), eliminates waste and avoids the use of toxic and/or hazardous reagents and solvents in the manufacture and application of chemical products. Green chemistry eliminates waste at source, i.e., it is primary pollution prevention rather than waste remediation. Green Chemistry is the utilization of a set of principles that reduces or eliminates the use or generation of hazardous substances in the design, manufacture and application of chemical products. It is better to prevent waste than to treat or clean up waste after it has been created. So says the first principle of Green chemistry; the E-factor.

E factor is the actual amount of waste produced in the process, defined as everything but the desired product. It takes the chemical yield into account and includes reagents, solvent losses, all process aids and, in principle, even fuel (although this is often difficult to quantify). Higher E-factor means more waste and, consequently, greater negative environmental impact. The ideal E factor is zero. It can be easily calculated from knowledge of the number of tons of raw materials purchased and the number of tons of product sold, for a particular product or a production site or even a whole company. But surprisingly many of the companies are not aware of this concept which was developed in the early 80s.

Now, it’s time for the chemical fraternity to come forward and vote for E-factor!