Rostovtseva Valeriia, Faykov Ilya, Pulyalina Alexandra
Institute of Chemistry, Saint Petersburg State University, Universitetskiy pr. 26, 198504 Saint Petersburg, Russia.
Membranes (Basel). 2022 Mar 10;12(3):312. doi: 10.3390/membranes12030312.
Ethylene glycol (EG) is an essential reagent in the chemical industry including polyester and antifreeze manufacture. In view of the constantly expanding field of EG applications, the search for and implementation of novel economical and environmentally friendly technologies for the separation of organic and aqueous-organic solutions remain an issue. Pervaporation is currently known to significantly reduce the energy and resource consumption of a manufacturer when obtaining high-purity components using automatic, easily scalable, and compact equipment. This review provides an overview of the current research and advances in the pervaporation of EG-containing mixtures (water/EG and methanol/EG), as well as a detailed analysis of the relationship of pervaporation performance with the membrane structure and properties of membrane materials. It is discussed that a controlled change in the structure and transport properties of a membrane is possible using modification methods such as treatment with organic solvents, introduction of nonvolatile additives, polymer blending, crosslinking, and heat treatment. The use of various modifiers is also described, and a particularly positive effect of membrane modification on the separation selectivity is highlighted. Among various polymers, hydrophilic PVA-based membranes stand out for optimal transport properties that they offer for EG dehydrating. Fabricating of TFC membranes with a microporous support layer appears to be a viable approach to the development of productivity without selectivity loss. Special attention is given to the recovery of methanol from EG, including extensive studies of the separation performance of polymer membranes. Membranes based on a CS/PVP blend with inorganic modifiers are specifically promising for methanol removal. With regard to polymer wettability properties, it is worth mentioning that membranes based on hydrophobic polymers (e.g., SPEEK, PBI/PEI, PEC, PPO) are capable of exhibiting much higher selectivity due to diffusion limitations.
乙二醇（EG）是化学工业中的一种重要试剂，包括聚酯和防冻液的生产。鉴于EG应用领域的不断扩大，寻找并实施用于分离有机溶液和有机-水溶液的新型经济且环保的技术仍然是一个问题。目前已知，渗透蒸发在使用自动、易于扩展且紧凑的设备获得高纯度组分时，能显著降低制造商的能源和资源消耗。本文综述了含EG混合物（水/EG和甲醇/EG）渗透蒸发的当前研究及进展，以及对渗透蒸发性能与膜结构和膜材料性能之间关系的详细分析。讨论了通过诸如用有机溶剂处理、引入非挥发性添加剂、聚合物共混、交联和热处理等改性方法，可以实现膜结构和传输性能的可控变化。还描述了各种改性剂的使用，并强调了膜改性对分离选择性的特别积极影响。在各种聚合物中，基于亲水性聚乙烯醇（PVA）的膜因其在EG脱水方面提供的最佳传输性能而脱颖而出。制备具有微孔支撑层的TFC膜似乎是一种在不损失选择性的情况下提高生产率的可行方法。特别关注了从EG中回收甲醇，包括对聚合物膜分离性能的广泛研究。基于CS/PVP共混物并添加无机改性剂的膜在甲醇去除方面特别有前景。关于聚合物的润湿性，值得一提的是，基于疏水性聚合物（如磺化聚醚醚酮（SPEEK）、聚苯并咪唑/聚醚酰亚胺（PBI/PEI）、聚电解质复合物（PEC）、聚苯醚（PPO））的膜由于扩散限制能够表现出更高的选择性。
