Reduction of fugitive VOC emissions using leak detection and repair (LDAR) in a petroleum refinery of Pearl River Delta, China

Abstract

Fugitive volatile organic compound (VOC) emissions from the petroleum-refining industry constitute a complex issue in China. This problem has a wide range of implications that require comprehensive measures, including a series of critical policing and legal injunctions in response to regional atmospheric pollution and the resulting safety hazards. In particular, process-based leak detection and repair (LDAR) surveys commonly used in developed countries should be vigorously promoted for fugitive VOC emission reduction. In this study, a campaign was conducted to measure the effectiveness of LDAR surveys by quantifying fugitive VOC emissions caused by equipment leaks in a local petroleum refinery in the Pearl River Delta (PRD) region of China. The leakage points detected in the initial survey accounted for 0.63 % of all the components within the refinery, among which open-ended pipes and valve packing had the highest ratio. After the procedure, the leakage rate was reduced to 0.23 %, suggesting a satisfactory repair performance. The process-based fugitive emission characteristics of each refining unit, storage tank, and loading area were investigated, and the corresponding composite profiles were estimated using the correlation equation method and data from the LDAR survey. Results demonstrated that the total emission of the refinery was 12,595.83 kg/a, with dominant VOC species of alkanes being emitted in nearly all units. Finally, the secondary organic aerosol formation potential (SOAP) and ozone formation potential (OFP) were estimated. All the above results were process-oriented and demonstrated that establishing a local LDAR system that considers the differences in VOC emissions from various manufacturing facilities should be the key strategy for future VOC emission reduction from the entire petroleum refining industry in China.