Abstract:

The biological method has successfully replaced the chemical method to produce long-chain dicarboxylic acids. Heavy components containing dibasic acids are produced in the extraction and purification of long-chain dicarboxylic acids in biological processes. Due to the complex composition, extraction of mixed dibasic acids from heavy components is a technical difficulty in the industry. This article aims at the mixed dibasic acids extraction technology for heavy components. First, the heavy component composition and the source of impurities were analyzed, and then the different extraction technologies and their technical principles were explained, while the advantages and disadvantages of each extraction method were compared. The results showed that the aqueous phase salt-acidification crystallization method was simple to be operated and contained no solvents. However, it consumed acid and alkali and generated more salt which needed to be treated. Organic solvent crystallization could be achieved by cooling crystallization after concentration. The method was compatible with the main production line process, and the amount of workload of equipment modification was small. The extraction method needed a solvent. Some special solvents could separate impurities such as pigments, but the solvent separation should be considered. It was difficult for chromatographic separation to achieve high resolution, while the operation of the column was complicated, which was not suitable for large-scale production. The key of the esterification separation method was to connect the esterified product to the market. Finally, based on the existing technology, it was proposed that future research needed to focus on the extraction process innovation, separation equipment processing and strengthening environmental protection measures.

Key words: long chain dicarboxylic acids, biological method, heavy components, mixed dibasic acids, extraction

摘要：

生物法已成功取代化学法制造长链二元酸，在生物法制备长链二元酸的提取精制中会产生含有二元酸的重组分。由于组成复杂，重组分中混合二元酸提取是行业中的一个技术难点。本文针对长链二元酸重组分中混合二元酸提取技术，首先对重组分组成及杂质来源进行分析，然后重点阐述了不同的混合酸提取技术及其技术原理，并对各自的提取效果和优缺点进行比较分析。结果表明，水相成盐-酸化结晶法操作简单，无需溶剂，但耗用酸碱，产生较多的盐，需要处理；有机溶剂结晶法可采用浓缩后冷却结晶的方式，与主生产线工艺契合程度高，设备改造工作量小；萃取法需要使用溶剂，一些特别的溶剂可以将色素等杂质分离，但需要考虑溶剂的分离效果；色谱分离法难以达到较高的分离度，色谱柱操作复杂，不适合大规模生产；酯化分离法关键在于需要把酯化产品与市场对接。最后，在现有技术的基础上，提出将来的研究需要将重点放在工艺创新、分离设备加工和加强环保措施上。

关键词: 长链二元酸, 生物法, 重组分, 混合二元酸, 提取