Abstract
This work focusses on the investigation of catalytic quality improvement of pyrolysis products. The yield of gases can increase significantly using Ni-Al2O3 and Ni-Al2O3/MoO3/CeO2 catalysts in case of both residential sewage sludge and farm waste sewage sludge raw materials (from 10.7-26.8% to 11.0-39.3%). It was found, that in addition to the oxygen content of the raw materials, the reaction conditions also greatly influenced the yield and properties of aqueous phase. The yield of aqueous phase was 9.7-17.9% without catalyst and that of 11.2-21.8% with catalyst. The amount of oxygen-containing organic substances in products (e.g. aldehyde, ketone and carboxylic acid) decreased significantly after the quality improvement. The efficiency of the catalysts was also influenced by the raw materials and temperatures in the 1st reactor. The hydrogen content and hydrocarbon distribution of the gas products changed favourably after the catalytic treatment, because less aldehyde, ketone, alcohols, carboxylic acids, phenols and its derivate were formed.
Keywords: waste, catalysts, pyrolysis, utilization, quality impr
