富气乙烷回收工艺改进及综合对比分析  

Improvement and comparative analysis of RSV ethane recovery process

作　　者：蒋洪 李浩玉[2] JIANG Hong;LI Haoyu(Petroleum Engineering School,Southwest Petroleum University,Chengdu,Sichuan 610500,China;PetroChina Changqing Oilfield Compang,Xi'an,Shaanxi 710018,China)

机构地区：[1]西南石油大学石油与天然气工程学院,四川省610500 [2]中国石油长庆油田公司

出　　处：《天然气工业》2022年第5期100-109,共10页Natural Gas Industry

摘　　要：乙烯生产能力是衡量一个国家石化工业发展水平的重要指标,其中乙烷作为乙烯制备的重要原料显得尤为重要。针对国内外应用广泛的RSV(Recycle Split Vapor Process)乙烷回收工艺在富原料天然气中回收乙烷时系统能耗高的问题,提出了2种RSV主体工艺改进流程——RSVG(Recycle Split Vapor with Gas Extraction Process)和RSVF(Recycle Split Vapor with Liquid Flashing Process),并在5种富气工况条件下,采用经济学和热力学分析方法进行了综合对比分析。研究结果表明:①2种改进的工艺流程均表现出一定的节能效果,其中改进的RSVF工艺节能效果明显;②冷箱内部板翅式换热器翅片等几何结构对投资成本影响大;③压缩机和膨胀机为投资最大的设备,约占总投资设备购买成本的70%。改进的工艺流程在运行工况下的财务净现值(Financial Net Present Value,FNPV)均大于零,项目投资回报率较大,回报时间更短,能满足基准收益率要求的盈利水平;④5种富气工况条件下改进工艺均表现出很好的适应性,且气质越富,节能越明显,其中塔器、压缩机及膨胀机和冷箱为㶲损的主要贡献设备。结论认为,2种RSV改进工艺在经济性及热力学层面均表现出一定的节能效果,其中RSVF改进工艺对轻重烃的预分离效果更好,乙烷回收工艺主要设备㶲损较小,节能潜力大,适应性更好。Ethylene production capacity is an important indicator to evaluate the development level of a country’s petrochemical industry,and ethane, as the important raw material to prepare ethylene, is quite important. When the RSV(Recycle Split Vapor Process) ethane recovery process which is widely used at home and abroad is used to recover ethane from rich feed gas, the energy consumption of the system is high. To solve this problem, this paper proposes two RSV improvement processes, namely RSVG(Recycle Split Vapor with Gas Extraction Process) and RSVF(Recycle Split Vapor with Liquid Flashing Process). In addition, they are compared and analyzed under five gas rich working conditions by means of economic and thermodynamic analysis. And the following research results are obtained.First, both improved processes show certain energy-saving effects, especially the energy-saving effect of RSVF process is remarkable.Second, the geometric structure of the fin of plate-fin heat exchanger inside the cold box greatly affects its the investment cost. Third, the compressor and expander are the main equipment with the largest investment, accounting for about 70% of the total equipment purchase cost. The FNPV of both improved processes under operating conditions are greater than zero, and the project has higher return on investment and shorer return time, which can reach the profit level required by the benchmark rate of return. Fourth, the improved processes present great adaptability under five gas rich working conditions. The richer the gas composition, the greater the energy saving. And the tower, compressor, expander and cold box are the main contributors to the exergy loss. In conclusion, both RSVG process and RSVF process present certain energy-saving effects from the perspective of economics and thermodynamics, among which, the latter has a better pre-separation effect on light and heavy hydrocarbons and its main ethane recovery equipment has less exergy loss, greater energy-saving potential and better adaptability.

关 键 词：富气 乙烷回收 RSV 改进流程 RSVG RSVF 板翅式换热器 经济分析 热力学 

分 类 号：TQ221.12[化学工程—有机化工]