CATALYTIC DESTRUCTION OF VOLATILE TARS PRODUCED BY PROCESSING BIOMASS FAST PYROLYSIS

In this research the gas refining from the tars was carried out by thermocatalytic method. To do this the pyrolysis gases flowed through the heated layer of alumosilicate catalyst impregnated by iron subgroup metal of various concentrations. The use of zeolite catalysts leads to the decrease the tars amount in a pyrolysis gas. The most active catalyst of the tars degradation in a pyrolysis gas for all the types of the studied feedstock is Co-containing catalyst. It was found that catalyst-substrate mass ratio, granules size and surface metal concentration affect the catalyst activity. The experiments showed that for the full removal of the tars from a combustible gas the mass ratio of alumosilicate catalyst-feedstock must be more than 1:20 by weight. The optimal catalyst granule size is chosen depending on the unit capacity according to the gaseous product formation and the system pressure. In the present research the optimal granule size was 1 mm. The use of metal-containing alumosilicate catalyst in the pyrolysis gas refining from the tars results in the change of the gas volume and heat value. Such metal content in the catalyst allows increasing C1-C4 hydrocarbons concentration and removing the tars from the combustible gas of the fast pyrolysis of the studied types of biomass.