Abstract:

The CO₂ emission reduction in power system is a high energy consumption process.Aiming at this point, a nearly zero CO₂ emission power system is proposed, in which the cold energy from liquefied natural gas (LNG) is utilized in the process of air separation for oxygen production together with the capture of CO₂.It is predicted that the unit power consumption by the proposed system using LNG cold energy could be reduced by 57.6% than that of the traditional air separation device in producing high pressure oxygen, liquid nitrogen and liquid argon.The exergy efficiency of the power cycle could be increased from 52% to 55.9%.Meanwhile, a mathematical model for this energy-saving and nearly zero CO₂ emission power system is established, with which the process parameters of the power system are analyzed.For a terminal with 3.0×10⁶ t·a^-1 LNG input, the proposed power system could save 2.78×10⁸ kW·h power per year and reduce 3.87×10⁵ t·a^-1 CO₂ emission, by which the economic benefits could reach 2.19×10⁸ CNY·a^-1.

Key words:

液化天然气, 冷能利用, 动力系统, 节能, CO₂减排

摘要：

针对动力系统CO₂减排能耗过高的问题，将液化天然气（LNG）的冷能集成用于空气分离制氧和CO₂近零排放动力循环的CO₂捕集，提出了一种利用LNG冷能的CO₂近零排放动力系统设计方案。研究结果表明：空分装置利用LNG冷能生产高压氧气、液氮和液氩等产品，生产能耗比传统空分装置降低57.6％，CO₂近零排放动力循环的火用效率可从52%提高至55.9％。同时，建立了CO₂近零排放动力系统利用LNG冷能的节能减排效益的数学模型，并对动力系统参数进行了分析。以一个进口量为3.0×10⁶ t·a^-1的接收站为例，CO₂近零排放动力系统利用接收站的LNG冷能每年可节省用电2.78×10⁸ kW·h，减少排放CO₂约3.87×10⁵ t·a^-1，经济效益可达到2.19亿元·a^-1。

关键词:

液化天然气, 冷能利用, 动力系统, 节能, CO₂减排