Hydrogen rich Syngas by Steam gasification of Waste Lignocellulosic Biomass

Abstract

The depleting petroleum reserve, as well as increasing demand for crude oil, has attracted the research interest for alternative sources of energy. The surplus lignocellulosic biomass such as forest residues, crop residues, and weeds may be a potential source to derive biofuel by the thermochemical route. Gasification is an established technology for the utilization of biomass to obtain producer gas containing mainly H2 and CO as combustibles. The air-blown biomass gasifiers are widely installed where the resulting producer gas contains 55-60 per cent nitrogen and a lower percentage of H2 and CO with an H2/CO ratio of less than one. Gasification of lignocellulosic biomass using steam as an oxidant produces syn-gas with a lower amount of nitrogen, a higher percentage of hydrogen, and H2/CO > 2.1. Steam as an oxidant favors water gas shift reaction with the formation of hydrogen and enhances the H2/CO ratio. The ratio of steam to biomass was 1.20-1.25 so the water gas shift reaction and steam reforming of methane occur. The percentage of hydrogen in the syngas obtained by gascification of pine needles, camelina straw and Lantana biomass was 56.8, 68.7, and 72.8 per cent respectively. The present article describes the steam gasification of pine needle biomass, crop residue from Camelina sativa, and biomass from weed i.e. Lantana camara to produce syngas with a higher H2/CO ratio along with a high calorific value compared to the one with air-blown gasification.