Biomass Gasification with Dolomite and Olivine Particles as a Bed Inventory in Presence of Ceramic Filters

Biomass gasification trials were carried out continuously in a bench scale gasification plant where the main component has been a fluidized bed reactor containing in its freeboard alternately, non-catalytic and catalytic ceramic filters already used in other gasification tests. The ceramic filters were delivered by Pall Schumacher. The fluidized bed inventory was composed of olivine particles contains alternately 10 % and 20 % by weight of dolomite particles. The fluidization gases were air and steam mixed with nitrogen to assure a good fluidization quality. The experimental tests have shown the beneficial effect of the presence of basic materials such as dolomite, which catalyses the hydrocarbons cracking reactions produced during the devolatilization/pyrolysis process of the biomass particles. The simultaneous presence of the iron content in the olivine particles and the nickel deposited on the ceramic filter, allowed to reduce the amount of tar in the product gas at a smaller concentration of 57 mg for normal cubic meter of dry and nitrogen free gas. The results demonstrate the goodness to carry out biomass gasification process in presence of a mixture of olivine and dolomite particles contained in a fluidised bed with a catalytic ceramic filter inserted in the freeboard of the gasifier. This plant configuration that use only one reactor, allows a significant simplification of the whole gasification process.