The production methods of 2,3-butanediol mainly include chemical method and microbial fermentation method. Due to the special structure of 2,3-butanediol-butanediol, chemical production of 2,3-butanediol consumes a lot of raw materials, complex process routes, large construction investment, and serious environmental pollution; while biological production of 2, 3-butanediol meets the requirements of green chemical industry and sustainable development. However, due to the high boiling point, high viscosity and high hydrophilicity of 2,3-butanediol, it is difficult to separate and purify 2,3-butanediol. Large, this process has always been the downstream key technology for the industrialization of biological preparation of 2,3-butanediol.
The separation and purification methods of 2,3-butanediol reported at home and abroad mainly include:
(1) spray drying method, which is about to pass high-temperature inert gas into the fermenter, so that the volatile gas is gasified, thereby separating 2,3-butanediol; (2) chemical conversion method, using formaldehyde or butyraldehyde and fermentation 2,3-butanediol in the liquid reacts, and the reaction product recovers 2,3-butanediol through distillation and acidification treatment; (3) activated carbon adsorption method, including activated carbon adsorption, acetone or dioxane Soxhlet extraction; (4) Countercurrent stripping method, including ethanol countercurrent stripping, filtration, rectification and separation of ethanol and other processes; (5) Solvent extraction method, through pH adjustment, heating, filtration, three-effect evaporation concentration, n-butanol extraction, acetic acid Butyl ester azeotropic distillation dehydration, esterification, and neutralization to obtain the diester form of 2,3-butanediol; (6) Fermentation-separation coupling method, including pervaporation, membrane distillation, vacuum membrane distillation, extraction Wait for the process. As can be seen from the research status at home and abroad, the separation and purification methods of 2,3-butanediol reported at present have very low separation efficiency and recovery rate of 2,3-butanediol; the process route is complicated, the energy consumption is high, and it cannot be realized Industrial production. Therefore, it is particularly important to develop an industrialized separation process that conforms to the characteristics of extracting 2,3-butanediol from a specific fermentation broth, is highly efficient, energy-saving, and environmentally friendly.