Paraffin-based crude oil refining process unit-level energy consumption and CO2 emissions in China

Abstract

Petroleum refining is a technology complex, energy- and CO2 emission-intensive industrial process, which is affected by the type and property of the crude oil. China has been the exploitation of crude oil to paraffinic most. This paper targets to quantify and evaluate the material or energy metabolism and environment loads of paraffin-based petroleum at refining process unit-level through the established petroleum flow and energy flow on the CO2 emissions accounting framework, and explores energy conservation and CO2 emission reduction pathways and policy implications, using a typical paraffin-based petroleum refining enterprise in China as a case. The results indicated that the crude oil from the inputs were fractionated in the atmospheric and vacuum distillation (AVD) unit, and its energy consumption and CO2 emissions accounted for 14.38% and 13.2% of the total energy consumption and CO2 emissions in the case study, respectively. With the transformation of petroleum refinery plant structure, fluid catalytic cracking (FCC), ketone benzol dewaxing (KBD), and delayed coking units dominated more energy consumption and CO2 emissions. FCC unit was both the largest energy consumer and supplier, flue gas waste heat recovery efficiency of which was an important factor affecting energy conservation and CO2 emission reduction for FCC unit and even enterprise. KBD unit records the largest energy and CO2 emission intensities, which are 67.95 kgce/t product and 256.82 kgCO2e/t product respectively, due to the high wax content of paraffin-based crude oil and the coal-dominated power generation structure. Based on these research findings, three mitigation policy recommendations were proposed, including the improvement of energy efficiency, optimization of energy consumption structure and product output structure. Carbon capture and storage can reduce CO2 emission by about a third in the concentrated units of primary energy consumption (i.e. AVD, FCC, and DC). The results of this paper are key components of the life cycle assessment of the CO2 emissions of petroleum fuels produced by domestic paraffin-based crude oil.