IMPROVEMENT OF PYROLYSIS LIQUID USABILITY BY STAGED CONDENSATION OF PYROLYSIS VAPOURS FROM ABLATIVE FLASH PYROLYSIS OF BARLEY STRAW

摘要

The thermal conversion process “pyrolysis” converts biomass in the absence of air into two primaryrnproducts: char and pyrolysis vapour. By cooling the vapours the condensable fraction can be separated as liquid phasernfrom the permanent gases. The ablative flash pyrolysis, where heat transfer to the biomass particles happens in directrncontact with a hot surface by mechanical force, aims at maximizing the liquid yield. The total condensates from strawrndirectly disintegrate into two liquid phases: a lighter aqueous phase and a heavier, highly viscous organic phase. Tornincrease the efficiency of processing and separation of individual substances, the pyrolysis vapours are condensed inrna staged process, so groups of substances are enriched in the fractions respectively generated as opposed to totalrncondensation. In this paper, the effect of pyrolysis temperature on the condensate yield and the formation ofrnindividual groups of substances were studied. The maximum of condensate yield was achieved at 540℃. On thernother hand more acids, alcohols and ketones have been formed with increasing the pyrolysis temperature from 486 torn580℃. Furthermore, a staged condensation of pyrolysis vapours can be regarded as useful due to a significantrnenrichment of substance groups. Thus, an (economic) material use of the condensates is possible.