Background

Dual extraction, high-temperature extraction, mixture extraction, and oleyl alcohol extraction have been proposed in the literature for acetone, butanol, and ethanol (ABE) production. However, energy and economic evaluation under similar assumptions of extraction-based separation systems are necessary. Hence, the new process proposed in this work, direct steam distillation (DSD), for regeneration of high-boiling extractants was compared with several extraction-based separation systems.

Methods

The evaluation was performed under similar assumptions through simulation in Aspen Plus V7.3^® software. Two end distillation systems (number of non-ideal stages between 70 and 80) were studied. Heat integration and vacuum operation of some units were proposed reducing the energy requirements.

Results

Energy requirement of hybrid processes, substrate concentration of 200 g/l, was between 6.4 and 8.3 MJ-fuel/kg-ABE. The minimum energy requirements of extraction-based separation systems, feeding a water concentration in the substrate equivalent to extractant selectivity, and ideal assumptions were between 2.6 and 3.5 MJ-fuel/kg-ABE, respectively. The efficiencies of recovery systems for baseline case and ideal evaluation were 0.53–0.57 and 0.81–0.84, respectively.

Conclusions

The main advantages of DSD were the operation of the regeneration column at atmospheric pressure, the utilization of low-pressure steam, and the low energy requirements of preheating. The in situ recovery processes, DSD, and mixture extraction with conventional regeneration were the approaches with the lowest energy requirements and total annualized costs.

中文翻译：

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基于提取的丙酮，丁醇和乙醇回收和纯化分离系统的技术经济分析。

背景

在文献中已经提出了用于丙酮，丁醇和乙醇（ABE）生产的双重萃取，高温萃取，混合物萃取和油醇萃取。但是，在基于提取的分离系统的类似假设下进行能源和经济评估是必要的。因此，将这项工作中提出的用于高沸点萃取剂再生的新方法，即直接蒸汽蒸馏（DSD）与几种基于萃取的分离系统进行了比较。

方法

被下类似的假设通过模拟在阿斯彭加V7.3进行评估^®软件。研究了两个末端蒸馏系统（非理想阶段的数量在70到80之间）。提出了一些机组的热集成和真空运行，以降低能源需求。

结果

混合工艺的能量需求（底物浓度为200 g / l）在6.4和8.3 MJ-燃料/ kg-ABE之间。基于萃取的分离系统的最低能量要求，加入底物中的水浓度相当于萃取剂的选择性以及理想假设分别为2.6至3.5 MJ-燃料/ kg-ABE。恢复系统对于基准病例和理想评估的效率分别为0.53-0.57和0.81-0.84。

结论

DSD的主要优点是再生塔在大气压下运行，利用低压蒸汽以及对预热的能源要求低。原位回收工艺，DSD和具有常规再生功能的混合物萃取是能耗最低且年度总成本最低的方法。