Study And Application Of VOCs Monitoring Technology In Natural Gas Purification Plant

At present,VOCs monitoring in China is in its infancy,and there is no unified method for VOCs monitoring.Therefore,in order to master VOCs emission in a natural gas purification plant,this paper conducted a study on VOCs monitoring technology in a natural gas purification plant.Firstly,VOCs source term of natural gas purification plant is investigated.VOCs source term is divided into organized emission source and non-organized emission source.After screening,8 categories of VOCs source term of natural gas purification plant are determined,including leakage of static and static seal points of equipment.Storage and volatile losses of organic liquids;Organized discharge of the process;Discharge of waste water during collection,storage and treatment;Release of circulating water cooling system in cooling tower;Combustion flue gas emission;Process no organized discharge and torch discharge,and the analysis of these 8 categories of VOCs source terms.Source for all kinds of VOCs emissions in a different way,studies is suitable for all kinds of VOCs emission source term monitoring technology,in this paper,the field monitoring of VOCs source monitoring technology research,mainly with equipment of dynamic and static seal leakage of VOCs monitoring technology,for storing harmonic emissions,waste water/organic liquid circulating water system,process exhaust/boiler dust emission,the unstructured VOCs monitoring,the in-situ sampling-gas chromatographic analysis of monitoring technology,sampling device and developed the volatile organic compounds and gas continuous sampling device,has been clear about the SBR pool open surface VOCs monitoring method;The VOCs content of torch emission is analyzed by referring to the exhaust group of torch gas and combined device.Through the establishment of VOCs database,the monitoring data of various VOCs source terms were analyzed and evaluated.The results showed that the leakage detection results of static and static seal points of the equipment showed that more than 99%of the detection values of the seal points were below 1?mol/mol,and 69%of the seal points were not detected(the detection limit was 0.4?mol/mol).The main volatile organic compounds in the wastewater of the combined plant were benzene series,which were not detected after monitoring.The main volatile organic compounds in the circulating water field are benzene series,which have not been detected by monitoring.The main volatile organic compounds in the wastewater treatment plant are benzene series,which have not been detected by monitoring.The concentration of VOCs(total non-methane hydrocarbon)in the respiration gas of organic liquid storage tank is between 2.49mg/m³ and 6.80mg/m³.The concentration of unorganized VOCs(total non-methane hydrocarbon)was between 0.38mg/m³ and1.15mg/m³,and the monitoring results of benzene,toluene and xylene were all lower than the detection limit of the monitoring standards.Referring to the main groups in the torch gas,which are divided into methane and SO₂ and NO_X in the tail gas of the combined device,the exhaust gas of the torch gas may contain trace amount of total non-methane hydrocarbon.