Energy Analysis and Bioremediation of Tar Applied to the Biomass Gasification Process

The present work focuses both on biomass energy conversion by means of gasification and pyrolysis, and on the tar bioremediation. In the first part a mathematical model, based on Gibbs free energy minimization, has been used to simulate the thermochemical processes and to characterize the producer gas from various feedstocks. Different process configurations have been taken into account by varying a set of parameters (such as equivalent ratio, steam to carbon ratio, temperature, feedstock water content and biomass ultimate analysis). The most efficient gasification/pyrolysis configuration has been assessed trough an overall energy balance carried out at the plant scale. For this purpose, three plant layouts have been modeled to compare different pathways suitable to generate syngas; in particular the gasifier has been coupled with an IC engine, a gas turbine and a CCGT (combined cycle gas turbine). The second part of this work is focused on the research of the bacterial species involved in tar degradation and on the assessment of their actual effectiveness in decomposing polycyclic aromatic hydrocarbons; for this purpose, activities carried out at the laboratory of the Free University of Bolzano are here be presented.