内部热耦合精馏塔构型研究

Study on configurations for a heat integrated distillation column

以丙烯-丙烷分离过程为例,研究了4种内部热耦合精馏塔的性能,并与常规精馏塔和热泵精馏塔进行了比较。结果发现,不同构型的内部热耦合精馏塔之间性能差异很大,其中提馏段与精馏段上端对齐,逐板进行热交换的构型性能最佳,其有效能耗比热泵精馏塔低25%—40%,节能效果显著。还探讨了内部热耦合精馏塔的压缩比与换热面积的关系,压缩比越小,换热面积越大,换热面积的逐板分布越不均匀。

Possible configurations for a heat integrated distillation column （HIDiC） were suggested and compared with a conventional distillation column and a heat-pump distillation column taking a propylene/propane splitter as the base case. The results show that thermal efficiency of HIDiC appears to be strongly sensitive to column configuration and a highly efficient asymmetrical configuration with stripping section stages thermally interconnected with the same number of stages in the upper part of the rectification section emerges as the most promising one. With this configuration it is possible to reduce the energy consumption by nearly 25%-40%, compared with a heatpump distillation column. The relationships among compression ratio of rectifying section to stripping section and heat transfer area were also discussed. The required heat transfer area increases and its stage-by-stage distribution becomes more and more uneven with the decreasing of compression ratio.