Stubble to energy

NS VENKATARAMAN

Ethanol is largely produced from molasses, a byproduct of sugar industry. Cellulosic bioethanol is produced from different feedstock such as woodchips, switchgrass and stubble by cellulose hydrolysis. Ethanol produced from molasses and cellulosic bioethanol produced from stubble are chemically identical. 

The production of bioethanol from cellulosic biomass will result in reduction of greenhouse gas emission by 86%, compared to 78% reduction from sugarcane biomass and 28% reduction from natural gas.

For the production of cellulosic bioethanol, stubble is first subjected to pretreatment to open up the structure of the cellulose components. The overall maximum yield of ethanol from cellulosic biomass can be around 56-58 per cent.

Government of India has made it mandatory for public sector oil marketing companies - Bharat Petroleum, Hindustan Petroleum and Indian Oil Corporation - to blend 10% ethanol with petrol. 

Recently, efforts have been made to set up facilities to produce bioethanol from cellulosic material such as stubble. However, these projects are in a preliminary stage. Considering the urgency of avoiding the problem of stubble burning, the government of India should give highest priority to set up cellulosic bioethanol projects in Punjab and Haryana  and also other states where cellulosic materials are burnt. The government should constitute a special task force to implement bioethanol projects. 

The writer is a chemical engineer and a director in Nandini Consultancy Centre, Chennai.