Study On VOCs Recovery Technology In The PVC Production By Calcium Carbide Process

The mainly VOCs gas in the production of calcium carbide process is acetylene and vinyl chloride which can heavy impact the human survival environment,safety and heavily,vegetation growth,weather and climate.This thesis aims at researching technical renovation to solve the recycling problem of acetylene,vinyl chloride gas which existing in the Xinjiang Huatai company PVC production.Then Huatai company factory bound unorganized atmospheric emissions NMHC to meets the"Integrated emission standard of air pollutants" GB16297-1996 requirements;the emissions of organized atmospheric vinyl chloride,NMHC and the vinyl chloride in wastewater meet the requirements which Huatai company needs to implement the standards of "caustic soda and PVC industrial pollutants emission standards"GB 15581-2016 on July 1,2018.The main work were as follows:1.Shortening the residence time of calcium carbide warehouse and silo,using nitrogen replacement to reduce weathering and recycling the acetylene gas of generator storage bucket improvement.Then making the unorganized atmospheric emissions NMHC total hydrocarbon content in average to achieve the requirements of "Integrated emission standard of air pollutants" GB16297-1996 which far less than 4mg/m3 and the total hydrocarbon content of methane was reduced by 80.56%than before.2.Through analyzing acetylene gas recovery unit production principle and the experimental test results of contact area to change the generator slag slurry treatment to water injection and drainage.Increasing the baffle plate in slag slurry stripping tower and raising the stripping tower vacuum pressure.Then the slag slurry in acetylene removal efficiency was increased by 83.41%than before and avoided security risks at the same time.3.Through the adjustment and optimization of process parameters of pressure swing adsorption device,determining the control temperature,adsorption pressure,adsorption time of feed gas which achieving optimal parameter setting and choosing combination of adsorbent filling way.After adjusting,vinyl chloride PSA 3#device emissions reached the vinyl chloride content was less than 10mg/m3 and NMHC total hydrocarbon content was less than 50mg/m3 that conforming to the standard requirements of "caustic soda and PVC industrial pollutants emission standards" GB15581-2016.4.Through analyzing the production principle and stripping tower structure principle of PVC slurry vinyl chloride stripping recycle device,then after transforming the 1#unit gas passing through sieve plate tower into the overflow weir stripping tower,the final drying emissions reached the vinyl chloride content was less than 10mg/m3 and NMHC total hydrocarbon content was less than 50mg/m3 that conforming to the standard requirements of "caustic soda and PVC industrial pollutants emission standards" GB15581-2016.And the vinyl chloride content in PVC resin products reduced greatly.5.Through analyzing the PVC production wastewater stripping unit principle and actual operation parameters,adding a wastewater buffer tank and related pump,then adjusting the DCS linkage control,finally realizing the PVC wastewater stripping unit reached the vinyl chloride content was less than 0.5mg/L standard requirement of "caustic soda and PVC industrial pollutants emission standards" GB15581-2016.