Cesium-Catalyzed Hydrogen Production by the Gasification of Woody Biomass for Forest Decontamination

Abstract

The large quantities of contaminated wood produced following the radioactive cesium decontamination of forests after the Fukushima Daiichi Nuclear Power Plant accident in 2011 can be used as a biomass resource for energy production via thermal treatment (e.g., gasification). To store the radioactive Cs ash produced from gasification, the immobilization of Cs in the pollucite structure is possible and requires stable Cs additives. In this study, a Cs additive (Cs 2 CO 3 , CsCl, CsNO 3 , or Cs 2 SO 4 ) was doped with timber waste sawdust (1−30 wt %). Fixed-bed downdraft-type continuous steam gasification experiments (0.7 g/min) showed that Cs 2 CO 3 enhanced H 2 production by 157% at 800 °C. X-ray absorption fine structure analysis and scanning electron microscopy observations revealed that the form of Cs on the surface of the char was Cs 2 CO 3 , which provided the active sites for gasification acceleration. Thermogravimetric pyrolysis and CO 2 gasification experiments showed that Cs 2 CO 3 lowered the activation energy and frequency factor while also enhancing the reactivity.

A review on thermochemical based biorefinery catalyst development progress

“…The increase of reaction temperature enhanced the rate of cracking and therefore the yield of gas increased. The study by Koido et al 95 showed that the production of H 2 was enhanced by metal salts. They selected Cs 2 CO 3 , CsCl, CsNO 3 and Cs 2 SO 4 as catalysts for the gasification of timber waste in a fixed-bed downdraft-type continuous steam gasification process at 800 °C.…”