A novel nickel/carbon catalyst for CH 4 and H 2 production from organic compounds dissolved in wastewater by catalytic hydrothermal gasification

Abstract

A novel Ni/carbon catalyst recently developed by the authors was used to gasify organic compounds dissolved in the wastewater with TOC concentration from 0.2 to 2%. The process removes the organic compounds by gasifying them into high calorific gases like methane and hydrogen. The investigations were focused on the efficiency of the Ni/carbon catalyst in terms of carbon conversion, conversion of big organic molecules, and catalyst deactivation due to sintering. The preliminary results showed that up to 99% carbon conversion can be achieved at 360 °C, and 20 MPa. A conversion mechanism was suggested which consists of: first, decomposition of big molecules to small molecules on the metal surface, steam gasification of small molecules to produce CO and H 2 followed by CO methanation and CO shift reaction to produce CH 4 and CO 2. The catalyst was found to be highly active and stable and no sintering was observed even after 100 h of reaction time.