IntroductionClostridium tyrobutyricum has considerable prospect in the production of organic acids. Globally, refinery final molasses is rich in sugar and reported to have high levels of accumulation and high emission costs, recognized as an excellent substrate for C. tyrobutyricum fermentation, but there is no suitable method available at present.MethodsIn this study, an acid-base treatment combined with a new green membrane treatment technology – a dynamic ion-exchange membrane -was used to pretreat refinery final molasses, so that it could be used for C. tyrobutyricum to produce butyric acid. A high-performance liquid chromatography method was established to determine the conversion of a large amount of sucrose into fermentable sugars (71.88 g/L glucose and 38.06 g/L fructose) in the treated refinery final molasses. The process of sequential filtration with 3, 1, and 0.45 μm-pore diameter dynamic ion-exchange membranes could remove impurities, pigments, and harmful substances from the refinery final molasses, and retain the fermentable sugar.Results and discussionThis means that refinery final molasses from the sugar industry could be utilized as a high-value by-product and used for the growth of C. tyrobutyricum, with industrial feasibility and economic competitiveness. Using the treated refinery final molasses as a carbon source, C. tyrobutyricum was screened by the method of adaptive evolution. The strain with butyric acid yielded 52.54 g/L, and the yield of the six carbon sugar was increased from 0.240 to 0.478 g/g. The results showed that combination of C. tyrobutyricum and ionic membrane technology broke through the bottleneck of its utilization of refinery final molasses. This study provided an innovative idea for the C. tyrobutyricum fermentation to produce butyric acid.

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Nuclear track membrane is a new type of membrane material with uniform pore size distribution. It can be used as a high-precision filtration membrane and there is a wide range of applications in sewage treatment, cell filtration, and biomedicine. The main production processes of nuclear track membrane include heavy ion irradiation and chemical etching, so there is a great significance about the research and design of etching lines. The main contents studied in this paper include the physical design principle of the etched line, the basic engineering structure, the basic control system architecture, and a complete HMI. The research plays an important role in the development and large-scale application of nuclear track membrane in this paper.