EFFECT OF BIOMASS ORIGINATED ASH IN CATALYTIC FAST PYROLYSIS OF BIOMASS

Fast pyrolysis is an attractive single-step process for solid biomass conversion to an intermediate liquid energy carrier, suitable for further production of liquid fuels [1]. It includes the rapid thermal decomposition of lignocellulosic material in absence of oxygen, followed by quick condensation of the vapours produced initially. The condensed liquid is a mixture of numerous organic molecules with water, together often called pyrolysis oil or bio-oil. Crude bio-oil has a heating value roughly equal to that of the biomass, which is almost half the heating value of fossil fuel oil [2]. To improve the quality of crude bio-oil in relation to biofuel applications, and to reduce the upgrading costs, biomass fast pyrolysis can be carried out in the presence of suitable catalysts. Catalysis, either by adding catalyst particles to the reactor (in situ) or by secondary conversion in the vapour phase (ex situ), is applied for the removal of oxygen and the catalytic cracking of high molecular weight compounds in the pyrolysis vapours. All biomass feedstocks contain various amounts (depending on their type) of inorganic ash-forming mineral nutrients in the form of cations which are bound ont