Life cycle assessment of petroleum refining process: A case study in China

Climate change mainly caused by transportation fuel consumption has attracted global concern. In life cycle environmental burdens generated from transportation fuel production, petroleum refining stage is the hotspot. However, the in-depth environmental analysis of petroleum refining is very limited. China is the second largest petroleum refining country, so it is very essential to break petroleum refining stage into specific unit to analyze how Chinese refinery can be improved in environment performance. To achieve this goal, a systematic life cycle analysis of the environmental burden generated from petroleum refining process was conducted to identify the control emphasis and seek potential improvement measures. Sensitive analysis and volatile organic compounds (VOCs) emission characteristics were additional discussed to improve the accuracy of results. The significant burdens generated from petroleum refining process were freshwater ecotoxicity and climate change. Crude oil extraction and transport dominated most environmental categories, which indicated that the environmental problem exist in upstream supply chain. Catalytic cracking, feedstock and product handling, catalytic reforming, crude oil distillation, cooling water system and diesel hydrotreating were the major control units due to their direct emissions and electricity consumption. VOCs (e.g., acrolein and chlorofluorocarbons) produced from refinery fugitive emissions were the main substances for refinery to reduce human toxicity, ozone depletion and photochemical oxidant formation influences. 14% of Climate change were derived from organic chemicals emission in this study, which suggested that VOCs-related carbon emission should be involved in current carbon accounting work or greenhouse gases (GHGs) studies on the petroleum refining industry. The identified control emphasis included equipment leaks from core refining units, storage tank emissions control, energy structure optimization and catalysts consumption intensity reduction. Some feasible and useful reduction measures targeted the control emphasis were proposed for policy makers and refinery managers to formulate reduction strategies and improve the sustainability of the petrochemical industry.