By Sunderarajan Padmanabhan
New Delhi: Unchecked growth of two perennial aquatic weeds- water hyacinth and para grass in the famous freshwater lake of Loktak in Moirang in Manipur is posing a major threat to brow-antlered deer, Sangai which is already on the verge of extinction. The overgrowth of the weeds has meant reduced space for indigenous plants of the lake on which Sangai feeds.
Researchers at Imphal-based Institute of Bioresources and Sustainable Development (IBSD) have sought to address the problem by exploring the possibility of using the weeds for production of valuable bio-oils and chemicals through the techniques of hydrothermal liquefaction and pyrolysis.
In Hydrothermal liquefaction, biomass is converted into bio-oils and chemicals by processing it in water in an autogeneous pressure environment for a specified time, causing the breakdown of solid biopolymeric structure to the liquid product and solid bio-char components. Pyrolysis, in turn, helps to degrade biomass substances into its fragments when heated in the absence of oxygen. The major products of biomass pyrolysis include bio-char (solid), bio-oil (liquid), and permanent gases such as methane, hydrogen, carbon monoxide, and carbon dioxide.
