单乙醇胺(MEA)捕获二氧化碳过程解吸能耗的模拟

采用ProMax2.0模拟了30% (质量分数)单乙醇胺填料塔吸收 - 解吸CO2的传统流程,考察了贫吸收液CO2负载(CLL)和溶液循环流速(SCR)对解吸用再沸器热负荷(Qreb)的影响.全系统模拟结果表明,当CO2 移除效率为90%时,CLL增加导致Qreb显著下降后再缓慢上升,其最佳值为0.20 mol CO2/mol MEA (MCPM),此时Qreb达最小值3.24 GJ/t CO2.单独的解吸系统模拟结果显示,当CLL 和富吸收液CO2负载(CRL)不变时,解吸塔中富胺进料流量的变化不影响热负荷.然而,由于全吸收 - 解吸系统CLL和CRL的变化则直接导致解吸塔富胺进料流量和热负荷的变化.

Simulation of the Effects of the Solution Lean Loading and the Circulation Rate on the Energy Requirements for Aqueous MEA-based CO2 Capture Process

The effects of CO_2 lean loading (CLL) and feeding rate of rich amine on reboiler heat duty (Qreb) for 30wt% MEA-based CO_2 baseline absorption-stripping process with a packed-bed absorber and a packed-bed stripper were simulated with ProMax2.0. The simulation was conducted for a whole absorption-stripping system and a decoupled stripping system, respectively, to obtain the single effect for each CLL and the solution circulation rate (SCR) that would otherwise impact Qreb interactively in the whole process. The results for the whole process simulation at 90% CO_2 removal efficiency showed that Qreb was rapidly dropped and then slightly increased with the increase of CLL. The minimum Qreb point was 3.24GJA CO_2, where CLL and CO_2 rich loadings (CRL) were 0.20 and 0.493 MCPM, respectively, and SCR was 335 NM~3/h. In contrast, for the decoupled stripping system, an increase in feeding rate of rich a-mine to the stripper under fixed CLL and CRL had no effect on the Qreb. However, the change of SCR for the absorption-stripping system, which was caused by a variation of solution composition including CLL, CRL or both, showed an influence on the heat duty.