Emission Characteristics, OFPs, and Mitigation Perspectives of VOCs from Refining Industry in China's Petrochemical Bases

ABSTRACT

China's petroleum refining industry has set off another climax and has entered a new rapid development by building seven petrochemical bases. Sector-based volatile organic compound (VOC) emissions from the refining industry in seven petrochemical-developed provinces in China were estimated for 1990–2019 and projected for 2020–2030 under the business-as-usual (BAU), new policy control (NPC), and the highest control (HC) scenarios. Furthermore, speciated VOCs and their ozone formation potentials (OFP) were estimated in 2019. Total VOC emissions from existing refineries were 541.14 Gg in 2019, of which 43.9%, 31.3%, 18.3%, and 6.6% were from fugitive, end-of-pipe, tank storage, and wastewater treatment sources, respectively. Alkanes were the most dominant compound in refineries, accounting for 55.2% of total emissions, followed by alkenes (18.9%) and aromatics (12.5%). Alkenes were the highest contributor to OFP, accounting for 59.5% of total OFP, followed by alkanes (22.3%) and aromatics (13.7%). n-Butane, ethylene, cis-2-Butene, n-Decane, and n-Pentane were the top five species with the highest emissions, accounting for approximately 50% of total emissions. Whilst, ethylene, cis-2-Butene, n-Pentane, n-Butane, and m/p-Xylene were the top five species with the highest contribution to OFPs, accounting for approximately 78% of total OFPs. In 2030, 741.03 and 165.28 Gg more VOC will be released than in 2019 under a non-control condition and the BAU scenario. It is estimated that 75.05 and 228.67 Gg of VOC from all refineries can be reduced under the NPC 2030 and the HC 2030 scenarios. To effectively reduce VOC emissions from refining industries, priority should be given to fugitive emissions by improving and upgrading the production processes and implementing enhanced leak detection and Repair system. More efficient control technologies should be invented for end-of-pipe sources. Vapor recovery systems and secondary seals have great potential for VOC emission reduction from storage tanks.