Sustainable Hydrogen Production via Supercritical Water Gasification of Agricultural Wastes

Biomass is an available and renewable resource that can be converted to valuable biofuels like bio ethanol and bio-hydrogen to supply future energy demand and reaching sustainable energy development objectives. Agricultural residues are valuable feed stocks that hundreds of thousands tons of it is burned annually in the lack of conversional industries in Iran. Gasification of biomass in supercritical water media is a promising technology to convert bio-products into useful fuels such as hydrogen as an energy carrier. In this article we studied the conversion of wheat straw, walnut shell and almond shell into the hydrogen. Hydrogen gas yields of 6.52, 4.26 and 4.1 mmoles were observed for the gasification of 1 gram of wheat straw, walnut shell and almond shell respectively, in a batch micro reactor. It was also observed that wheat straw had 42.6% and 46.9% hydrogen and carbon gasification efficiency respectively, which was the highest among the others. Furthermore, according to the structural analysis, it was recognized that biomasses with higher cellulose and hemicellulose and lower lignin contents were better gasified due to their higher and easier solubility and hydrolysis in water.

Keywords:

Sustainable energy , Biomass , Hydrogen Production , Supercritical water gasification