Application Study On LDAR-based VOCs Pollution Treatment

According to the Reports of the 19 th National Congress of the Communist Party of China,“pollution treatment” has been confirmed as one of the three tough fights.Among the unprecedented measures taken by the Chinese government for pollution treatment,the regional pollution prevention strategy of “2+26 Beijing-Tianjin-Hebei Atmospheric Contamination Direct Channel Cities” has taken the leading position.Over 10 traditional coal chemical enterprises in Jincheng,Shanxi province,as the domestic production base of nitrogenous fertilizer,have turned into the key objects for pollution treatment,with the principal products of synthesis ammonia,methyl alcohol and urea production).This industry is characterized by unsystematic and direct emission of VOCs.However,the treatment of unsystematic VOCs emission for this industry in China are featured by the late start,less emphasis,immature national treatment technology and uncompleted control measures,supervision approaches and technology criteria;consequently,China’s study on VOCs treatment for this industry in China has been still at the initial stage so far,with the universal application still in the blank.Therefore,it is of a profound significance to confirm the source of pollutants and emission of VOCs and seek for the suitable treatment technology and technical proposal,in order to promote the emission reduction of VOCs and improve the air quality of the environment.This paper took the traditional coal chemical enterprises in Jincheng as the instances;summarized the requirements for the upgrading and transportation of VOCs pollution treatment urgently to be implemented by traditional coal chemical enterprises within the scope of Jincheng,Shanxi province;and expounded on the research on VOCs emission and development status of coal chemical enterprises at home and abroad.In the form of on-site investigation,this paper firstly conducted the qualitative analysis on the source of VOCs pollution;then conducted the quantitative analysis on VOCs pollution emission in different workshop sections of traditional coal chemical enterprises,on the basis of leak detection and repair(LDAR);confirmed the source and quantity of VOCs emission;and launched the targeted leakage repair.On this basis,this paper integrated the actual production of traditional coal chemical enterprises to launch an investigation and comparison on VOCs treatment technology and technical proposal of the petrochemical industry and propose four technical approaches for the upgrading and transformation of VOCs pollution.After the project implementation,the effectiveness evaluation and supervision on Shanxi Jinfeng Coal Chemical Industry Co.,Ltd.was conducted with the concrete conclusions as follows:1.The qualitative analysis on the application for LDAR technology to VOCs treatment of traditional coal chemical industry was very effective,with an annual leakage repair and emission reduction rate of 44.91%.2.The four proposals of upgrading and transformation for environmental protection have shown the significant results:a.Methanol exhaust absorption method based on washing and activated carbon,with a treatment rate above 90%.b.Sealed exhaust recovery method with secondary combustion,gas making,circulating water and settling pond,with a treatment rate above 80%.c.Sealed exhaust recovery system method based on desulfuration for exhaust regeneration and desulfurication and decarburization rich liquor with flash steam,with a treatment rate above 80%.d.Water treatment station with sealed exhaust recovery,high-energy ultraviolet ray photooxidation and activated carbon adsorption water treatment station,with a treatment rate above 90%.The enhancement and transformation measures for environmental protection will improve the operation environment and conditions within the plant area,reduce the emission of VOCs and benefit the improvement of air quality of the regional environment.