Weeds show potential

Two of the country's most widespread weeds, Parthenium (Congress grass) and water hyacinth, will be used to produce petroleum-based chemicals. The National Environmental Engineering Research Institute (NEERI) in Nagpur has discovered these weeds and other cellulose-rich wastes such as banana stems can totally replace petroleum products used in the production of chemicals and biochemicals.

Petroleum derivatives such as propylene, acetone and ethanol are obtained by the fermentation of glucose, which is stored in cellulose. The millions of tonnes of cellulose that are available in nature can thus be utilised for petrochemical products. "NEERI is one of the most advanced laboratories in the world to convert cellulose into liquid glucose and thereafter to petrochemicals," claims P Khanna, director of the institute.

The new method is an advance on the previous practice of using commercial glucose as a substrate for the production process. NEERI has also improved glucose recovery from the weeds to 90 per cent from its previous recovery rate of 42 per cent.