Hydrogen Production by SCWG Treatment of Wastewater from Amino Acid Production Process

Abstract

The organic wastewater obtained from an amino acid production process was treated by supercritical water gasification (SCWG) method for achieving water purification and hydrogen production. A set of SCWG experiments was also carried out with glucose and valine solutions as model compounds for reducing sugars and amino acids present in the wastewater, respectively. The effect of temperature (600—700 °C) and different catalysts (activated charcoal (AC), Ni/AC, and Ni―Y/AC) on the extent of gasification and gas composition was investigated in a continuous-flow reactor at 28 MPa and 12 h ―1 LHSV. Complete gasification of organic compounds in the wastewater was achieved in the presence of the supported nickel catalysts, resulting in the formation of gaseous products with high hydrogen contents. Alkaline salts present in the wastewater feed contributed to hydrogen formation reactions. Solid product formed during the SCWGs of the wastewater feed was identified as one of main obstacles for a possible commercial design and a schematic concept was suggested for its removal.