Hoffmann Andreas, Franz Alexander, Löser Christian, Hoyer Thomas, Weyd Marcus, Walther Thomas
Chair of Bioprocess Engineering Institute of Natural Materials Technology Technische Universität Dresden Dresden Germany.
Interfaculty Centre for Bioactive Matter b-ACT Matter Leipzig University Leipzig Germany.
Eng Life Sci. 2024 Sep 30;24(12):e202400041. doi: 10.1002/elsc.202400041. eCollection 2024 Dec.
Ethyl acetate is at present exclusively produced from fossil resources. Microbial synthesis of this ester from sugar-rich waste as an alternative is an aerobic process. Ethyl acetate is highly volatile and therefore stripped with the exhaust gas from the bioreactor which enables in situ product recovery. Previous research on microbial formation of ethyl acetate has focused on the kinetics of ester synthesis and in part on the ester stripping, while the separation of the ester from the exhaust gas has hardly been investigated. A mixed matrix membrane was developed consisting of Silikalite-1 embedded in polydimethylsiloxane which was installed in a radial-symmetrical membrane module. Evaluation of the separation of ethyl acetate was based on the analysis of the composition of the feed and retentate gas by mass spectrometry. The separation efficiency of the membrane was first tested with varied flows of artificial exhaust gas, containing defined amounts of ethyl acetate. A model for describing the separation process was parametrized by the measured data and used to design a real separation experiment. Ethyl acetate produced from delactosed whey permeate by DSM 5422 in a stirred bioreactor gassed with 0.5 vvm air was successfully separated from the exhaust gas by membranes; 93.6% of the stripped ester was separated. Liquid ethyl acetate was recovered by cooling the permeate gas to ‒78°C, whereby 99.75% of the condensed organic compounds were ethyl acetate. This study demonstrates for the first time that microbially produced and stripped ethyl acetate can be effectively separated from the exhaust gas of bioreactors by membrane technology to obtain the ester in high yield and purity.
目前，乙酸乙酯完全由化石资源生产。以富含糖的废料为原料通过微生物合成这种酯作为替代方法是一个需氧过程。乙酸乙酯挥发性很高，因此会随生物反应器的废气被带出，这使得能够原位回收产物。先前关于微生物合成乙酸乙酯的研究主要集中在酯合成的动力学上，部分研究涉及酯的汽提，而从废气中分离酯的研究几乎没有。开发了一种由嵌入聚二甲基硅氧烷的Silikalite-1组成的混合基质膜，并将其安装在径向对称的膜组件中。基于通过质谱分析进料气和截留气的组成来评估乙酸乙酯的分离情况。首先用含有一定量乙酸乙酯的人工废气的不同流量测试膜的分离效率。通过测量数据对描述分离过程的模型进行参数化，并用于设计实际的分离实验。在搅拌式生物反应器中，以0.5 vvm的空气曝气，由DSM 5422从脱乳糖乳清渗透液中产生的乙酸乙酯成功地通过膜从废气中分离出来；93.6%的汽提酯被分离出来。通过将渗透气冷却至-78°C回收液态乙酸乙酯，其中99.75%的冷凝有机化合物是乙酸乙酯。这项研究首次证明，通过膜技术可以有效地从生物反应器的废气中分离出微生物产生并汽提出的乙酸乙酯，从而以高收率和高纯度获得该酯。
