Catalytic reactive flash volatilisation of microalgae to produce hydrogen or methane-rich syngas

Catalytic reactive flash volatilization (RFV) is a single-step char- and tar-free alternative to the gasification process at low temperatures (600-650 degrees C). In this work catalytic RFV of microalgae Scenedesnws sp. was performed using steam as a gasifying agent. Effect of temperature and steam content on the gasification efficiency and syngas composition was studied in presence of Ni-Rh/gamma-Al2O3 catalyst which showed that at 650 degrees C and carbon-to-steam ratio of 0.12, H-2 rich (65% (v/v)) syngas was generated, whereas, in presence of Ni-Cu-Pd/gamma-Al2O3 catalyst at 600 degrees C and carbon-to-steam ratio of 0.12, CH4 rich (16% (v/v)) syngas was generated. Gasification efficiency of 83% and 93%, respectively, was achieved without tar formation. Furthermore, the molar ratio of H-2-to-CO in case of H-2-rich syngas was 10.9. The alkali and alkaline earth metals present in the microalgae act as a catalyst in the reaction which lead to stable catalytic performance.