Thermal Processes for Biomass to Energy Conversion

Production of energy from biomassis an attractive alternative to conventional fossil fuels. Use of solid organic wastes to produce biofuel is seen as a promising route from the sustainability point of view. Pyrolysis is one of the possible thermochemical methods to convert solid biomasses to valuable liquid and gas products. In this study, the slow pyrolysis process of poultry litter was investigated using different experimental and analytical techniques. A fixed bed reactor was used for the simulation of the slow pyrolysis process up to a constant temperature (400-800°C) under nitrogen flow. Yields of the different product fractions were determined. Several analytic methods were used to characterise the products. On-line FTIR techniques were used to detect the most significant compounds in the evolved gas. GC-MS results allowed the identification of the most important categories of compounds in the liquid condensate. HCNS composition of the products was revealed by elemental analysis and the fate of nitrogen and sulphur, present in relevant amounts in the original substrate, was studied. The energy transfer from the original biomass substrate to the different product fractions was also investigated. However, the bio-oil obtained from pyrolysis can be used as biofuel only after an upgrading step. A suitable method for upgrading bio-oil is catalytic cracking of the pyrolysis products, which converts high molecular weight compounds of the bio-oil into lower-weight molecules. Therefore, in the following step of the present study in-situ catalytic pyrolysis of poultry litter was studied by zeolites (zsm-5) catalyst. In order to study the effect of influential factors (temperature and catalyst to biomass ratio) on the obtained products, experimental design techniques were used. Overall, the results achieved shed some light on the potential use of the slow pyrolysis process for sanitation and waste-to-energy valorization of poultry litter.