Research and design experience of a 1 million tons/year CO2 capture project in the Shengli oilfield of Qilu petrochemical.

Abstract

This study presents a comprehensive overview of a pioneering 1 million-ton carbon capture, utilization, and storage (CCUS) project implemented in the Qilu Petrochemical Shengli Oilfield in China. The project involved a compression-condensation-purification process and aimed to capture CO₂ from the coal gas of the second chemical fertiliser plant of the Qilu Petrochemical Company. Molecular sieves were used to dry the captured CO₂, and MellapakPlus™ structured packing was employed for purification. Two novel energy-saving processes were implemented, a lithium bromide refrigerator unit to recover waste heat for cooling and an expansion generator unit to recover pressure energy from the tail gas. The project layout and land area were carefully determined. The consumption of utilities in the capture system was analysed. Furthermore, an economic assessment of the project was conducted. The technical and economic feasibility of this project was confirmed by the findings. The comprehensive energy consumption per unit of the capture process was 2.649 GJ/t CO₂, the total investment (excluding tax) for CO₂ capture was CNY 380 million (380 CNY/t CO₂), the payback period of the project was 9.20 years, and the sales price (excluding tax) of the project was 194.4 CNY/t CO₂ at a yield of 8%.