Batch distillation is widely employed in the fine chemical industry because of its operational flexibility. The mixture of n-heptane and isobutanol exhibits a special azeotropic phenomenon by which it changes from a minimum-boiling azeotrope to a maximum-boiling one with increasing pressure. However, the traditional double column batch rectifier and double column batch stripper processes cannot separate the mixture efficiently. Therefore, the double-column batch stripper–rectifier (DCBS-R) process was designed to obtain high-purity products, based on the azeotropic phenomenon. Further, control structures are explored to achieve stability, and the final purities of the separated products are over 99.9%. Each batch of raw materials is 100 kmol, and the expected annual production capacity is 800 batches. Additionally, a precooler of the low-pressure column (LPC) is introduced to reduce the exergy destruction by exergy analysis. The equipment cost and CO emissions are analyzed afterward to optimize the process, based on the multi-objective optimization method. Further, the number of stages and the pressure of the columns are optimized. The optimal obtained total annual cost (TAC) and CO emissions of the DCBS-R process are 2.26 × 10 $/y and 4.92 × 10 kg/y, respectively. The partial heat integration is studied to further improve the process performance, thus obtaining TAC and CO emissions of 2.22 × 10 $/y and 3.80 × 10 kg/y, which are 7.1% and 22.76% lower than the values obtained from the optimal process, respectively.

中文翻译：

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用于分离具有不同沸腾行为的二元共沸物的新型变压间歇精馏工艺的设计和综合分析


间歇蒸馏因其操作灵活性而广泛应用于精细化工行业。正庚烷和异丁醇的混合物表现出一种特殊的共沸现象，随着压力的增加，它从最低沸点共沸物变为最高沸点共沸物。然而，传统的双塔间歇式精馏塔和双塔间歇式汽提塔工艺无法有效地分离混合物。因此，基于共沸现象，设计了双塔间歇式汽提塔-精馏塔（DCBS-R）工艺以获得高纯度产品。进一步探索控制结构以实现稳定性，分离产物最终纯度达到99.9%以上。每批次原料100公里，预计年产能800批次。此外，引入低压塔（LPC）预冷器，以减少火用分析造成的火用破坏。随后基于多目标优化方法对设备成本和CO排放进行分析以优化工艺。此外，优化了塔的级数和压力。 DCBS-R 工艺的最佳年度总成本 (TAC) 和 CO 排放量分别为 2.26 × 10 $/y 和 4.92 × 10 kg/y。研究部分热集成，进一步提高工艺性能，获得TAC和CO排放量分别为2.22×10 $/y和3.80×10 kg/y，比优化工艺得到的值分别降低7.1%和22.76% ， 分别。