Research On Combustion Utilization And Exhaust Gas Purification Technology Of Solid Waste In DOP Production

The treatment of harmless,reduced,and resource is the main content of solving the problem of solid waste pollution.At present,the treatment and disposal methods of solid consist of safe landfill,biological composting and heat treatment.Safe landfill occupy a limited amount of land resources,and bio-composting needs to meet the microbial needs for living environments.The heat treatment of solid waste produced by chemical industry is an effective way to achieve waste reduction,harmless and resource treatment,and has become a hot topic in the research of solid waste treatment at home and abroad.The solid waste component produced by the plasticizer dioctyl phthalate?DOP?is not complicated,mainly organic substances such as activated carbon and DOP.The organic combustible components are high,the calorific value is high,and the ash content is low.After combustion,VOCs,NO_x,particulate matter and other pollutants may be generated.As long as the flue gas is further purified,the discharge can be achieved.This paper has done a comprehensive study on the physical and chemical analysis of industrial solid waste generated in DOP production,aerobic combustion,purification of exhaust gas,and process design.The main contents of this paper are summarized as follows:?1?Research on combustion special effects and purification technology of DOP solid waste.In the tube furnace,the combustion conditions are controlled to investigate the type and concentration of the combustion exhaust.When the tube furnace heating rate is 10?/min and the air flow rate is 3.6 L/min,the burned rate of solid waste reaches 69.9%.The combustion of solid waste is divided into two stages:when the temperature is around 250?,most of DOP escapes from the activated carbon and oxidizes to form methane,ethane,benzene,toluene,ethylbenzene,xylene and 4-ethyltoluene.When the temperature is around400?,the activated carbon is burned together with a small portion of the residual DOP.The peak concentration of VOCs during combustion is 245.4 mg/m³ at 200?and 254.9 mg/m³ at400?.The sieve is used to detect the concentration of the particulate matter.When the combustion mass is 1.0 g,the solid waste combustion has a particle diameter of more than 25?m?500 mesh?and the concentration of the particulate matter is 47.92 mg/m³,and the concentration of the particulate matter larger than 74?m?200 mesh?is 37.74 mg/m³;After adsorption by activated carbon,the removal rates of particulate matter above 25?m and above 74?m are 68.8%and 81.5%,respectively.And the removal rate of VOCs at 400?maximum is 67.1%.?2?Preparation of Bi₂MoO₆,TiO₂@Bi₂MoO₆ photocatalyst and study on degradation of toluene.Bi₂MoO₆ and TiO₂@Bi₂MoO₆ are prepared by solvent hydrothermal method,and the catalysts are characterized by BET,XRD,SEM,TEM,BET,UV-vis,PL and XPS.The results show that TiO₂ can be uniformly distributed on the surface of Bi₂MoO₆.Compared with Bi₂MoO₆,the band gap width of TiO₂@Bi₂MoO₆ is wider and the specific surface area is increased.When the reaction time is 120min,the degradation rate of toluene reached 26.08%,and the degradation rate of TiO₂@Bi₂MoO₆ to toluene is 17.92%higher than that of Bi₂MoO₆.It can be seen that the adsorption effect and photocatalytic degradation effect of TiO₂@Bi₂MoO₆ on toluene are better than that of Bi₂MoO₆,and TiO₂ enhances the photocatalytic performance of Bi₂MoO₆.?3?Preparation of MIL-101,TiO₂@MIL-101 photocatalyst and study on degradation of toluene.Similarly,MIL-101 and TiO₂@MIL-101 are prepared by solvent hydrothermal method,and the catalysts are characterized by BET,XRD,SEM,TEM,BET,UV-vis,PL and XPS.The results show that the band gap width of TiO₂@MIL-101 is narrower than that of MIL-101,and the specific surface area is reduced.In the photodegradation experiment of toluene at 120min,the degradation efficiencies of MIL-101 and TiO₂@MIL-101 are 16.07%and 39.28%.After TiO₂ composite modification,the degradation rate of TiO₂@MIL-101 toluene increased by 23.19%.?4?Engineering design and calculation of DOP solid waste in circulating fluidized bed combustion.A new process of combustion treatment of DOP solid waste in circulating fluidized bed boiler technology is proposed,and the whole process is designed and calculated.The designed processing capacity of the circulating fluidized bed is 600 tons/year.The results show that the circulating solid fluidized bed is used to treat the DOP solid waste.The organic matter such as activated carbon contained in the solid waste is fully circulated and burned at around 850?,and mainly produces CO₂.And water,the exhaust gas may contain trace organic pollutants,the exhaust gas content of exhaust gas<15mg/m³,NO_x content<22mg/m³,VOCs content<17mg/m³,all meet national emission standards.The ash content after combustion is<17%,and the main component of the bottom ash obtained is SiO₂ and a small amount of conventional metal oxide,which can be used as building materials such as paving and infrastructure.The entire process design process is in line with national environmental standards and is conducive to the recycling and reuse of resources.