We present the design of a novel oxygen-steam-air updraft gasification plant and technological process capable of delivering high quality producer gas. Gas with calorific value of 8 MJ/m 3 is cleaned with an absorption type gas purification unit and then coupled with a piston engine for electricity production with 31% efficiency. We present the results of test runs of the installation with various combinations of gasification agents and plasma torch influence on gas quality and tar removal. We have used a classical hot plasma torch for tar cracking, but it creates a problem with proper gas mixing with very high temperature flame requiring special design of the mixing chamber. In the future development we plan to install a cold plasma reactor for more selective heavy tar reforming prior to gas entering purification unit.

We present an analysis of influence of biomass pre-treatment and change of gasifying agent on the performance of an oxygen-steam-air updraft gasification plant and a technological process capable of delivering high quality producer gas. The results of these changes on composition of tar collected with absorption type gas purification unit, designed for dust and tar removal are also reported.