Study On The Characteristics Of Sewage Sludge Fluidized Bed Gasification Tar

The generation characteristics of sludge gasification tar was studied by the sludge fluidized bed steam gasification experiment.The chemical compositions and pyrolysis characteristics of tar was studied by Gas Chromatography-Mass Spectrometer(GC-MS)analysis and TG-DTG-DSC thermoanalysis respectively.The effects of different gasification medium and gasification temperature on tar yield and chemical composition of sludge gasification was studied.The results show that When the gasification temperature is 850?,the gasification medium has the highest and lowest tar yield under water vapor and air,respectively,while the yield under air-water vapor is centered,the yield of aromatic hydrocarbon,aromatic hydrocarbon derivative and heterocyclic compound in tar is the highest in which the gasification medium is air-water vapor,the yield of aliphatic compounds is the highest when the medium is water vapor and the yield of alicyclic compounds is the highest when the gasification medium is air.The tar yield is the highest when the gasification medium is air steam,and the lowest is at 850?.Aliphatic compounds was produced only at 700?,the yield of the alicyclic compounds reached the maximum at 750?,the yield of aromatics decreased?aromatic hydrocarbon derivatives firstly increase and then decrease?heterocyclic compounds firstly decrease and then increase and then decrease with the increase of gasification temperature.The effects of the gasification agent and gasification temperature on the chemical components of five compounds,including aliphatic compounds,alicyclic compounds,heterocyclic compounds,aromatic hydrocarbons and aromatic hydrocarbon derivatives in tar was investigated.The results show that at 850?,Aliphatic compounds are produced only under water vapor conditions,alicyclic compounds and heterocyclic compounds yield the highest yield under air and steam conditions,The yields of indene.biphenyl?fluorene and phenanthrene compounds in aromatic hydrocarbons reached the maximum under water vapor conditions.In air water vapor conditions,aliphatic compounds are produced only in 700?,the yield of the aliphatic compounds is highest at 750?,heterocyclic compounds are mainly pyridine and 4,4'-bis(tetrahydrothiopyran),the yields of the Nene and phenanthrene compounds in aromatic hydrocarbons reach the maximum value at 850 and 750?,the yield of nitrile and quinoline compounds in aromatic hydrocarbon derivatives reached the maximum at 750?.The effects of gasification temperature(700,750,800 and 850 ?)and gasification agent(air,water vapor,air water vapor)on the combustion characteristics of tar in the sludge fluidized bed gasification were studied.The results show that the pyrolysis weight loss process of the 6 kinds of gasification tar is divided into 3 stages,the first two stages are the stage of volatilization and pyrolysis of light organic matter,and the third stage is a small amount of heavy organic matter decomposition stage.6 gasification tar.The first two stages of weight loss are all greater than the third stage.