ABSTRACT
Vapor processing device is a device that can control the headspace pressure in the underground storage tanks and recover the vapor. By analyzing the chemical composition of volatile organic compounds (VOCs) at the inlet and outlet of the vapor processing device, the ozone formation potential (OFP) and secondary organic aerosol formation potential (SOAP) were estimated by maximum incremental reaction (MIR) and fractional aerosol coefficients (FAC), and the secondary pollution formation contribution of VOCs were quantitatively evaluated. The results showed that:â the ρ(total volatile organic compounds, TVOC) at the inlet and outlet of the vapor processing device were 436-706 g·m-3 and 4.98-10.04 g·m-3, respectively. Alkanes (72%±4%), oxygenated organics (14%±2%), and olefins (11%±5%) were the dominant components of VOCs emissions. There were little differences in VOCs emissions from the different vapor processing devices; the key species were i-pentane (approximately 25%), followed by n-butane, i-butane, and n-pentane. â¡ The ozone source reactivity (SR) of VOCs emissions from the outlet of the vapor processing device was 2.6-3.3 g·g-1, and the OFP was 3.5-25.6 g·m-3. Olefins contributed the most (43%-69%), followed by alkanes (20%-35%) and oxygenated organics (10%-22%). Butene, cis-2-butene, trans-2-butene, i-pentane, and propionaldehyde were the species that highly contributed to OFP. ⢠Aromatics in VOCs emissions contributed the most to SOAP (80%-92%), and the main active species were toluene, 1, 2, 4-trimethylbenzene, 1, 3, 5-trimethylbenzene, and p-diethylbenzene. The research showed that different VOCs species emitted by the vapor processing device contributed obvious differences to the secondary atmospheric pollution, and butene species and aromatics such as toluene were the focus of VOCs emission control of vehicle gasoline and vapor processing device.
ABSTRACT
Chinese emission standard of air pollutants for bulk gasoline terminals (GB 20950-2007) stipulate standards for vapor emissions during gasoline storage and receiving in bulk gasoline terminals. However, the standards are not applicable to crude oil, aviation kerosene, naphtha, and other kinds of oil. We assess emission standards or directives for vapor processing equipment in terminals in the United States (US) and European Union (EU), and analyze the emission status of vapor processing equipment in three typical cities in China. We further propose revisions to GB 20950-2007. We made the following observations. â US and EU standards include scope not only for gasoline, but also crude oil and other organic liquids. â¡ The emission limits of non-methane hydrocarbons defined in GB 20950-2007 are i) 0.5, 1.8, and 8.9 times those defined in Subpart XX, Subpart R, and Subpart Y in the US federal regulations, ii) 1.8 and 3.1 times those defined in Rule 462 and Rule 1142 in southern California law, and iii) 0.7 and 500 times those defined in EU and German directives, respectively. The vapor leakage limit for general areas of China is 0.5 times that defined in Subpart XX of the US standards, whereas the limits for some other specific areas of China, are 0.7 and 2.0 times those defined by Rule 462 and Rule 1142 in southern California law. ⢠The numerical range of P5th-P95th of NMHC emissions from the inlet and outlet of vapor processing equipment in three typical cities of China were 115-811 g·m-3 and 0.1-20.0 g·m-3, respectively. The proportion of NMHC emission concentrations less than or equal to 10 g·m-3 at the outlet of vapor processing equipment was>85%. We suggest that the scope of application of GB 20950-2007 should be extended to crude oil, gasoline (including ethanol gasoline), aviation kerosene, and naphtha. The emission concentration limit of NMHC from vapor processing equipment should be tighten from 25 g·m-3 to 20 g·m-3, with a emission limit of 10 g·m-3 added for particular cases.
ABSTRACT
As a subcenter of the city of Beijing, Tongzhou District is faced with enormous pressure from the rapid growth of VOCs emissions from service stations. In this study, a set of bottom-up VOCs inventory estimation methods for service stations in Tongzhou District is established. Using local VOCs emission factors of service stations in Beijing, combined with gasoline and diesel sales from every service station, a high resolution VOCs emission inventory of service stations in Tongzhou District from 2015 to 2022 was established. The results showed the following. â An online monitoring system (OMS) based on unloading, refueling, and tank pressure vapor emission control measures can reduce the VOCs emission factor from 190 mg·L-1 to 115 mg·L-1, and when the percent onboard refueling vapor recovery system (ORVR) Penetration reaches to about 50%, the emission factors can be reduced to 131 mg·L-1 and 96 mg·L-1, respectively. The VOCs emission factor (13 mg·L-1) of diesel from the service station is 0.8% of the uncontrolled emission factor (1552 mg·L-1) of gasoline. â¡The amount of VOCs emissions from service stations in Tongzhou District was 97.8 t·a-1 in 2015, and the emissions of gasoline and diesel were 96.2 t·a-1 and 1.6 t·a-1, respectively, accounting for 98.4% and 1.6%. The emissions were mainly concentrated in the area surrounding the new Beijing Municipal Government site. â¢After implementation of the vapor recovery requirements of "Beijing's Clean Air Action Plan from 2013-2017," considering the increase in oil sales from 2017 to 2022, VOCs emissions of gasoline and diesel from service stations will decrease by 9% and 6%, respectively, compared to those of 2015 in Tongzhou District. Assuming that the OMS will also be installed at 28 (2000-5000) t·a-1 service stations by the end of 2022, VOCs emissions of service stations will be reduce by 13% compared to those of 2015. â£The measure of restricting the number of vehicles in operation by 50% can reduce VOCs emissions of service stations by (22±12)% every day during 2014 Asia-Pacific Economic Cooperation conference (APEC). â¤It is suggested to strengthen vapor recovery supervision on service stations in the area surrounding the new Beijing Municipal Government site, and in summer and refueling idle such as in noon.
ABSTRACT
VOCs emission of service station is one of the main sources of VOCs in Beijing. Uncontrolled emission factor (UEF) of refueling in China, US EPA, EEA respectively is 2.16, 1.31 and 1.00 times of CARB UEF (1008 mg·L-1). China's gasoline standards have changed in the last 20 years, and there is an urgent need to carry out the localization of gasoline refueling VOCs emission factor research. This paper compared test methods for refueling emission factors of European Union (EU) and California Air Resources Board (CARB) and found that the EU method was simpler and easier to operate than the CARB method, so we processed refueling VOCs emission factors test device in reference to EU test methods and chose a set of United States Stage â ¡ vapor recovery system in Beijing service stations to carry out studies on VOCs emission factors. The results showed that: 1 For the fuel test tank, refueling vapor recovery efficiencies were 0.93 and 0.83 times of air to liquid volume ratio (A/L) of Stage â ¡ respectively in winter and summer. Refueling emission factor in summer was greater than that in winter, and its recovery efficiency was lower than that in winter. 2 For the social vehicles, winter and summer refueling UEF respectively was (525±42) mg·L-1 and (963±174) mg·L-1, at the same time was 0.52 and 0.95 times of CARB refueling UEF (1008 mg·L-1) in A/L=0.The average value of emission factors respectively was (55±30) mg·L-1 and (112±108) mg·L-1 in A/L 1.05-1.07 in winter and summer. 3Refueling UEF without vapor recovery of social vehicles was chosen as the localized summer and winter refueling UEF in Beijing, we could calculate the emission factor of vapor recovery in different A/L combining with the linear equation of the fuel test tank.
