| The development of Lanzhou Xigu petrochemical industrial district has provided an important boost to regional economic growth, whereas there exists obvious environmental air quality issues because of the emission of atmospheric pollutants especially volatile organic compounds and odor. Therefore, how to solve the VOCs and odor issues effectively in Xigu petrochemical industrialdistrict has become one of the hottest issues among local residents, companies and government of Lanzhou City.This paper analyzed tank area, laoding trestle district and sewage treatment plants in Lanzhou Xigu petrochemical industrialdistrict.Find out the optimal control measures via investigating the activity levels of the regional sources, simulating emission-reduction. And thus come up with theoretical supports and references on the choice of treatment program for government and companies.(1) Calculate source strength of Xigu petrochemical industrialdistrict tank, laoding trestle area and sewage treatment plant area based on " Technical Guide for Atmospheric Volatile Organic Compounds Source Emission Inventory " and " Technical Guide for Atmospheric NH3 Source Emission Inventory ". We divided the source area into 9 parts. For the source strength of VOCs, transportation trestle plant is the largest emission with the intensity of 3182.41t/a, while oil storage is the least emission with the intensity of 11.44 t/a. However, for the source strength of odor, the emission mainly comes from chemicals chemical sewage treatment plant area and refining sewage treatment plant area, the source intensity of NH3 is 10.24 t/a and 9.07 t/a, respectively.(2) AERMOD model was used to forecast VOCs and odor based on simulating different emission-reduction situations. The results showed that odor was maily produced by sewage during oil refining and chemical wastewater handling. The concentration of NH3 was dramatically decreased in the sensitive area where was located closely to the equipment of oil refining and chemical wastewater handing, among which Daijiahewan village contributed to 88.00% reduction concentration, while the decrease of VOCs concentration was weak. The largest VOCs emission region was laoding trestle area in the simulating emission-reduction situations. VOCs emission was obviously decreased in the area where was the closest to oil commodity field. It accounted 90.74% reduction of VOCs strength compared to the baseline situation. The sensitive points was the main area where the pollutants contributed the most to the source strength reduction when calculating on all emission-reduction projects.(3) According to the predicted results and combining with Lanzhou Petrochemical Company’s future development plans and national policy of the petrochemical industry VOCs and odor control, we propsed practical reduction plans on laws and regulations, control technology and emission standards of laoding trestle and sewage processing equipments:①Cover the aeration tank, settling basin and other uncovered pools in refinery wastewater treatment plant. Both solvent solubilization and biological oxidation should be used to collect and process the gas, then the treated gas can be exhausted by the high cylinder which is more than 15 meters.②Cover the grease sedimentation tank, concentration tank, mud wells and other uncovered pools in chemical sewage treatment plant. Biological deodorization method should be used to collect and process the gas, then the treated gas can be exhausted by the high cylinder which is more than 15 meters.③The oil and gas recycling equipment, that is kerosene or diesel pre-absorbing- caustic and activated carbon desulfurization-adsorption process, should be established in crude oil 159,164 car loading trestle of the oil storage and transportation factories. As for 160,161 train trestle, 139 # 138/2# automobile laoding trestle and 16 # train loading trestle, activated carbon adsorption gas recovery units should be set. Moreover, pre-absorbed-membrane separation technology oil gas recovery units should be established on 163 "BTX",7#and 12# train loading trestle. |
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