Principles of Green Chemistry for Sustainability in the Chemical Industry

We have been hearing a lot of this phrase lately - green chemistry. What is it? And why is it growing so much in importance these days?

Our modern developed world is one which is heavily dependent on the use of chemicals. We worry about recycling and reusing, but a lot of damage to the environment is caused right at the manufacturing stage. The philosophy of green chemistry is to strike at the root - at the production stage itself.

Green Chemistry (or Environmental Chemistry) is the invention, design and application of chemical products and processes that reduce or eliminate the use or generation of hazardous substances.

Specifically, green chemistry seeks to develop processes that are among other things, safe, energy efficient, have minimum side products and use easily available raw materials. It is essentially a chemical engineering practice to move towards a more sustainable and environmental friendly chemical industry.

The 90's witnessed a scenario where industries were facing immense social as well as economic pressure due to laws and regulations on disposing or utilizing hazardous wastes that resulted as side products or even used products.

Green Chemistry emerged in the scientific, political and industrial scene as the savior to lead us on the path of sustainability. Green Chemistry has appeal in the chemical industry because

• Often greener methods are economically more viable.
• They may sometimes require some investment but getting rid of hazardous wastes also means getting rid of their disposal and cost due to regulations. In totality, they still prove economically beneficial.
• The environmental benefit cannot be undervalued. An industry that uses sustainable methods has better chances of surviving in the years to come, as raw material availability becomes scarce and environmental issues gain absolute importance.

The first book that led to the beginning of green chemistry was Benign by Design, Alternative Synthetic Guide for Pollution Prevention published in 1993 by Paul T. Anastas and Carol A. Farris.

The book Green Chemistry: Theory and Practice by Paul Anastas and John C. Warner, published in 1998 developed the 12 principles of green chemistry, which aim to guide us to realize the benefits of green chemistry. These focus on concepts like

• Using raw materials, solvents etc. that are less hazardous, safe to use and renewable
  
• Processes that have higher efficiency, fewer steps and are such that maximum of the initial raw product occurs in the final product rather than numerous side products.
  
• Products should be designed for easy degradation.

As an example of the applications of green chemistry, consider this -

The traditional process for the synthesis of the Drug ibuprofen consists of a six-step synthesis with an atom efficiency of 40%, remaining 60% are undesired by-products and waste. The new process has only three catalytic steps and an approximately 80% atom utilization. In addition the new process saves 20-40% of the total energy required in the traditional process.

Today, scholarships are awarded for breakthrough technologies in the field of Green Chemistry. Curriculla have been developed at the school level for encouraging a culture of Green Chemistry in the thought of students at the most basic level. Programs are available for professional training for teachers and experts. Refer this link for more detailed information on these.

http://www.beyondbenign.org/greenchemistry/greenchem.html

http://www.iupac.org/publications/ci/2007/2905/1_tundo.html