Fast Pyrolysis of Sewage Sludge

Fast pyrolysis of sewage sludge (SS) for bio-oil production is considered as a promising alternative technology instead of its less acceptable common disposal processes. However, high nitrogen content in SS represents a drawback of pyrolysis use due to the formation of nitrogen containing species (NCSs), causing severe environmental pollution during the utilization as fuel. It is of great importance to study the formation, distribution, and chemical composition of NCSs in pyrolysis products of SS in order to minimize the nitrogen content for fuel use or effectively convert them for chemical use. Main investigations include: (1) understand the effects of temperature and sweeping gas flow rate on the yields of pyrolysis products and the distributions of carbon and nitrogen; (2) pyrolysis of SS and biomass in an internally circulating fluidized-bed (ICFB) to evaluate bio-oil production; (3) fractionation of the bio-oil from the SS fast pyrolysis by silica-gel column chromatography and identification of organonitrogen compounds in the fractions; (4) study the formation and separation of triacetonamine (TAA) in the SS bio-oil using acetone as the absorption solvent.