Study On The Characteristics And Control Measures Of Wastewater From Coal-to-olefins Project

Modern coal chemical industry is a kind of clean production technology of coal which has a broad prospect of development.With the attention of coal to olefins in China,the technology of coal to olefins has become an important branch of modern coal chemical technology.However,the difficulties in the treatment of wastewater from coal olefin project are widespread,such as poor water treatment quality,difficult to be fully reused and environmental safety problems.Therefore,it has become the main environmental bottleneck for the development of coal olefins project.In order to solve the problem of coal to olefins wastewater treatment,most studies have focused on the process development of terminal treatment technology,this paper starts from the source control.Monitoring of wastewater samples in each section to analysis the composition of pollutants.Trace its origin and formation mechanism.With the engineering analysis of main production equipment to put forward the production process improvement measures and pretreatment technology.To provide technical support for the sustainable development of coal derived olefins in china.Selection of a built coal to olefin project wastewater as the research object,according to the factory unit flow order,16 groups of wastewater COD,TOC petroleum,ammonia nitrogen,chloride,pH and other indicators of water quality monitoring,and then select 6 groups of core unit wastewater samples,the total components analysis by GC-MS,to determine the type and the number of organic pollutants in water,and then combined with the chemical reaction principle of the production process,analysis of the source of pollutants and the formation mechanism.Furthermore,by analyzing the point of pollutant production,the order of pollutant generation is analyzed,and the transfer relation of pollutant in each device is traced.The results show that the pollutants in wastewater include catalyst,fine powder,organic acid,oxygen compounds,wax,oil and so on.In the gasification of water,methanol distillation water,MTO quench tower bottom water,MTO stripper bottom water,chemical water station detected in water samples containing cedrene,cedrol and a variety of heterocyclic molecules of refractory organic pollutants.The most important waste water treatment process in the process is from the MTO system.The fouling capacity of the plant is mainly affected by the degree of methanol rectification,the content of the recombinant component,the content of metal ions and the selectivity and activity of the catalyst.In this paper,coal to olefins plant in the existing water treatment problems were summarized,the process unit is improved and the ash water treatment unit is carried out for the gasification unit.In the quench tower at the end of the addition of sewage outfall and liquid-solid separator,oil separator and other separate treatment device.Follow-up can be added settling pool,condensate pool to achieve water purification.In the installation of additional water,settling tank and quench water settling tank for the quench tower and washing tower.Put forward the constructive suggestions on improving the end of treatment,additional optimization measures,reduce the end treatment of existing load pressure,to solve the water problems restricting the development of coal to olefins.