Study On Tar Condensate Collection System With Amphiphobic Material

As the main energy of China,a lot of tar was produced in the process of coal pyrolysis and gasification,which can reach more than 15 million tons.In recent years,with the depletion of fossil fuels and the environmental problems caused by its utilization,the utilization of biomass has been gradually taken seriously.In addition to coal and biomass,the pyrolysis process of municipal solid waste and sludge also produces a lot of tar.The tar is an important by-product of heat treatment of traditional energy and the process of heat treatment of renewable resources.Tar with high viscosity,poor liquidity,low calorific value is complicated which has macromolecular compounds,such as aromatic characteristics.Besides,tar can easily stick to the pipe of reaction system,which brings problems such as blockage.It is an exigence that tar sticks to the pipe of reaction system easily and causes blockage,even more dangerous situation,which has to be settled urgently.Tar is a hazard for human dermal system,nervous system,kidney and lung,even cause more serious lesion.Although tar has many weaknesses,tar contains many substances that can be used as a product or as an energy source after being processed,which means tar is still full of the economical value.This study constructed amphiphobic material on stainless steel with simple immersion method and electrochemical deposition method.Then their micro-structure was observed with scanning electron microscopy(SEM).In addition,thermogravimetric analyzer and contact Angle measurement instrument were used to evaluating the amphiphobic materials'performance in different environment.The amphiphobic material by simple immersion method has contact angle of 141.13°and 130.34°for water and tar,respectively.It's heat resistance can last below 300~oC.But the method spent so much time constructing the amphiphobic materials,then this study proposed using electrochemical deposition method to construct amphiphobic material.Then this study found the optimum condition with 5 V,3 h,0.02 mol/L.The amphiphobic material with exquisite micro-structure has contact angle of143.52°and 133.26°for water and tar,respectively.Its heat resistance can operate under the condition of 300~oC for hours.This study set up a system with multi-stage tar condensing system,which has three level of temperature(300~oC,100~oC and 0~oC).Liquid products of flash prolysis was compared with liquid products of slow prolysis with FTIR and GCMS.The results found that a lot of large molecular weight compounds such as aromatic compounds is the main components of product1 collected at 300~oC,most of ketones and organic acids have been gathered at product 2collected at 100~oC,and phenol and aldehyde is concentrated at product 3 collected at 0~oC.Then the amphiphobic material was applied to pipes of multi-stage condensation system,as a result,the total recovery rate increased by 12.57%,and recovery rate has been improved.According to water content analyzing,the water content of each product increased and 80%of water in tar was collected in products 3 at 0~oC.The pipe of condensate recovery system has little tar adhesion after 4 pyrolysis experiments for 10 hours.Though there is a small amount of tar deposits,the whole system running steadily with none clogging.Amphiphobic material and multi-stage condensation system helped the improvement of recovery and primary separation.Compare to extracting from the original tar,this system obtain the products needed in industrial manufacturing easier,which means decrease of energy and cost.