关键词: 分离, 化学过程, C₂回收率, CO₂冻堵, 模拟, 操作参数的优化

Abstract: While raw material changes to ethane and propane from cheap natural gas, the production cost of ethylene is only 30% of the cost when heavy oil, such as naphtha, is adopted as raw material. In addition, during the transmission of natural gas into cities, natural gas at high-pressure needs to get pressure adjustment, and the process can generate lots of pressure energy available. The paper proposes a process to separate and recover light hydrocarbon from high-pressure natural gas. The capacity is 60×10⁴m³/h. With the consideration of light hydrocarbon recovery, system consumption, CO₂ freezing and cold box heat transfer temperature difference, operating parameters are optimized to accomplish an efficient system energy integration, therefore achieve energy-saving and cost-reducing of the whole process. In this work, C₂ recovery rate can reach up to 90%, thus can provide 557500 tones of high quality ethane per year for ethylene unit, which can break the bottleneck of raw material in the development of ethylene industry, and enhance the overall economic benefits of natural gas and ethylene industry.

Key words: separation, chemical processes, C₂ recovery rate, CO₂ freeze, simulation, optimization of operating parameters