The Development Of Regenerative Catalytic Combustion Technology And It's Treatment Of VOCs From Synthetic Leather Industry

In recent years,the haze which show frequently have influenced people' s life and health.PM_2.5 which serves as the major pollutant can remain in atmosphere for a long time and damage the respiratory system of human from interior.Volatile organic compounds are the major precursors of PM_2.5 and can damage the health of human directly.What is more,the secondary pollutants which generate from volatile organic compounds like ozone and secondary organic aerosols can work the mischief much more serious.Synthetic leather industry is one of the leading industries in the southeast coastal area and one of the 13 key industries for volatile organic compounds treatment in Zhejiang Province.It has a great impact on the air quality for the high concentration of enterprises and the serious pollution of organic waste gas.The organic waste gas come from the volatilization of volatile organic compounds in raw material and regularly been disposed by spray which effect poorly.At the same time,dimethyl formamide recovery system would produce a large number of dimethylamine wastewater.Due to bad odor,it can' t be directly poured into the sewage treatment station and the enterprise will be sprayed into the boiler combustion,resulting in fuel-NO_x seriously exceeded.In this paper,typical synthetic leather enterprises were investigated and the source spectrum analysis of exhaust volatile organic compounds was carried out.The total concentration of volatile organic compounds in the organic waste gas from dry workshop was 817 mg/m³ including 85.1%of alkane,6.3%of butanone,1.9%of aromatic hydrocarbon and 4.8%of dimethyl formamide.The total concentration of exhaust gas volatile organic compounds from wet and post-treatment workshop was 1492 mg/m³ including 96.6%of alkanes,0.3%of butanone and 1.4%of aromatic hydrocarbons.Accounting to the O₃ production potential and secondary aerosol production potential of volatile organic compounds in exhaust gases,we found that butanone contributed 3.4%O₃ production potential and aromatic hydrocarbons contributed 4%O₃ production potential and 27.2%secondary aerosol production potential in the organic waste gas from dry workshop.Butanone contributed 0.1%O₃ production potential and aromatic hydrocarbons contributed 2%O₃ production potential and 23.4%secondary aerosol production potential in the organic waste gas from wet and post processing workshop.The other O₃ production potential and secondary aerosol production potential was contributed by alkane.As a simulation of pollutants of toluene,butanone,dimethyl formamide and dimethylamine,we selected the catalytic combustion technology to use a manganese-based composite transition metal catalyst for pilot test.The results showed that the catalytic combustion for butanone and dimethyl formamide were degraded 99%at or above at 300?and dimethylamine was degraded more than 97%at 320?with the gas hour space velocity of 20000 h-1.Fuel-NO_x exceeded seriously from the the thermal combustion of dimethylamine.A portion of dimethylamine could precede SCR reaction with fuel-NO_x at the existence of catalyst,so the concentration of NO_x in exit got controlled.The selectivity of N2 generation in the tail gas was kept at around 85%.Based on the research results,a set of regenerative catalytic combustion treatment demonstration project which has the capacity of 2000 m³/h was designed.The organic waste gas in the workshop was condensed into the regenerative catalytic combustion furnace for catalytic combustion degradation.The waste water from the rectification recovery tower was blown off and removed most of the dimethylamine,then the off gas enter into the regenerative catalytic combustion furnace for regenerative catalytic combustion which generate little NO_x.The treatment cost of 10,000 m³ waste gas was 69.6 Yuan.Therefore,the research results and demonstration projects in this paper can provide reference for the regulation of volatile organic compounds in synthetic leather industry.