三元無共沸蒸餾系統之熱整合複雜蒸餾塔序列

Abstract

在本篇論文中，研究了熱整合複雜蒸餾塔序列作為熱耦合蒸餾的替代方案，以降低三元無共沸蒸餾系統之成本和能耗。對兩種工業相關的六碳及七碳脂肪烴混合物和七種三元無共沸混合物在十種進料組成下的蒸餾配置進行了優化和比較。 研究結果顯示，熱整合複雜蒸餾塔序列在兩種工業相關混合物的分離表現都優於隔板牆蒸餾塔。熱整合複雜蒸餾塔序列與傳統蒸餾塔序列相比，成本降低了13.0% (MCM混合物)以及17.2% (LMC混合物)，而隔板牆蒸餾塔與傳統蒸餾塔序列相比，成本降低了1.7% (MCM混合物) 和7.1% (LMC混合物)。七種三元無共沸液體混合物在十種進料組成下（共70例）的結果顯示，如果不考慮熱整合，70例中有39例隔板牆蒸餾塔有最低總成本，與成本較低的傳統蒸餾塔序列相比，平均可以節省19.1%的總成本。如果考慮熱整合，則在70 例中有49例熱整合複雜蒸餾塔序列有最低總成本，僅有11例隔板牆蒸餾塔有最低成本，與成本較低的傳統蒸餾塔序列相比，平均可以節省21.0%的總成本。研究結果顯示，工業界應考慮熱整合複雜蒸餾塔序列作為隔板牆蒸餾塔的替代方案，以減少多元混合物蒸餾過程中的能耗。 在本篇論文中，我們比較了熱整合複雜蒸餾塔序列與其它熱整合側流蒸餾塔序列在分離苯/甲苯/對二甲苯混合物的表現。由研究結果得知，複雜蒸餾塔序列較易被熱整合，因此熱整合複雜蒸餾塔序列在所有熱整合側流蒸餾塔序列中有最低成本。

In this work, stacked complex sequences (SCSs) are studied as an alternative to thermal coupling for reducing cost and energy consumption in ternary zeotropic separations. Distillation configurations are optimized and compared for two industrially relevant C6-C7 aliphatic hydrocarbon mixtures and seven ternary zeotropic mixtures at ten feed compositions. The results show that SCSs outperform dividing-wall columns (DWCs) in both industrial-relevant cases, reducing cost relative to the conventional sequence by 13.0% (MCM) and 17.2% (LMC) compared with 1.7% (MCM) and 7.1% (LMC) for DWCs. Results for seven liquid mixtures at ten feed compositions for each mixture (70 cases) show that if column stacking (CS) is not considered, DWCs are preferred in 39 out of 70 cases, saving on average 19.1% compared to the preferable conventional (direct or indirect) sequence. However, if CS is permitted, SCSs are preferred in 48 out of 70 cases saving on average 21.0% compared to the preferable conventional sequence. DWCs are preferred in only 9 cases. This suggests that SCSs should be given serious consideration as an alternative to DWCs for reducing energy consumption in multicomponent distillation processes. Besides, SCS is compared with other stacked side-stream sequences for the separation of mixture BTX. Result show that complex sequence can be easily stacked and has the lowest TAC among all stacked side-stream sequences.