Olivine, dolomite and ceramic filters in one vessel to produce clean gas from biomass

摘要

Graphical abstractDisplay OmittedHighlights•Syngas free of particles and with very low amount of tar is produced from biomass gasification.•Combination is tested of primary catalyst in the gasifier fluidized bed with catalytic ceramic candles in its freeboard.•Remarkable process intensification and thermal integration is obtained.•The adoption of catalytic filter candles doesn’t increase the required standard filtration surface in practical applications.AbstractHeavy organic compounds produced during almond shells gasification in a steam and/or air atmosphere, usually called tar, are drastically reduced in the product gas by using simultaneously in one vessel a ceramic filter placed in the freeboard and a mixture of olivine and dolomite particles in the fluidized bed of the gasifier. The content of tar in the product gas during a reference gasification test with air, in presence of fresh olivine particles only, was 8600mg/Nm3of dry gas. By gasifying biomass with steam at the same temperature level of 820°C in a bed of olivine and dolomite (20% by weight), and in the presence of a catalytic ceramic filter inserted in the freeboard of the fluidized bed gasifier, the level of tar was brought down to 57mg/Nm3of dry producct gas, with a decrease of more than two orders of magnitude.