Method for producing 1,3-propylene glycol by micro aerobic-anaerobic continuous flowing glycerol-adding multi-tank series fermentation

Abstract

The invention discloses a method for producing 1,3-propylene glycol by micro aerobic-anaerobic continuous flowing glycerol adding multi-tank series fermentation, and belongs to the technical field of biochemical engineering. The method is characterized in that the method utilizes a series mode of at least three fermentation tanks according to the micro aerobic and anaerobic properties of the 1,3-propylene glycol produced by microbial fermentation, and adopts different aeration modes and flowing glycerol adding strategies in different fermentation tanks. The micro aerobic fermentation of the first fermentation tank promotes vigorous growth of bacteria; the anaerobic flowing glycerol addition of the second fermentation tank improves the concentration and conversion rate of the 1,3-propyleneglycol; and the anaerobic fermentation of other fermentation tanks further improves the concentration of the 1,3-propylene glycol, and meanwhile consumes the residual glycerol. The invention has the advantages of fully playing the characteristics of each step of fermentation, improving the concentration of the bacteria, the final concentration of the 1,3-propylene glycol and the production strength, reducing the final concentration of the glycerol and the production cost, realizing continuous production and providing an economic and feasible method for producing the 1,3-propylene glycol by a microbial fermentation method.

Description

technical field [0001] The invention belongs to the technical field of biochemical industry, and relates to a method for producing 1,3-propanediol by microbial continuous feeding glycerin fermentation, in particular to a microaerobic-anaerobic continuous feeding glycerin multi-tank series fermentation method for producing 1,3-propanediol method. Background technique [0002] 1,3-Propanediol (1,3-Propanediol, referred to as 1,3-PD) as an important chemical raw material is widely used in industries such as printing ink, printing and dyeing, coating, lubricant, antifreeze, and can also be used as medicine and Intermediates of organic synthesis. 1,3-PD can also be used as a polymer monomer to synthesize polymer materials, especially the new polyester fiber polytrimethylene terephthalate (PTT) with excellent synthetic performance. PTT is considered to be a new type of polyester material that combines the high performance of polyethylene terephthalate (PET) and the ease of proce...

AI Technical Summary

Problems solved by technology

Among them, batch fermentation can obtain higher product concentration, but the production intensity is low; batch fed-batch feeding is currently the main way for microbial fermentation to produce 1,3-PD, which can obtain higher product concentration and production intensity, but batch flow feeding Addition fermentation is the same as batch fermentation. Due to the need for frequent operations such as tank placement and sterilization, it leads to long non-production time, short service life of equipment, and high production costs, which is not conducive to large-scale industrial production; while continuous fermentation is conducive to improving production intensity. , the product quality is stable, the non-production time is short, and regular automatic production can be realized, and it is easy to realize industrialization, but the outstanding problem of continuous fermentation is that the product concentration is low

In order to increase the concentration of 1,3-PD, the researchers achieved it by increasing the concentration of glycerol in the fermentation medium. For example, Menzel et al. produced 1,3-PD by anaerobic continuous fermentation under the condition of an initial glycerol concentration of 145g / L. The concentration can reach 48.5g / L (Enzyme Microbiol Technol.1997,20 (2): 82-86), but due to strong substrate inhibition, the dry weight of the thalline is only 0.7g / L, and the fermented liquid The concentration of residual glycerol is as high as 48g / L, which causes a great waste of raw materials and increases the difficulty of subsequent product separation

In order to reduce the concentration of residual glycerol in the fermentation broth, people such as Seraphim used two tanks in series to carry out anaerobic continuous fermentation, which can reduce the concentration of residual glycerol in the fermentation broth to 8.6g / L, but the production intensity is low, only 3.4g / L h (J. Biotechnol. 2000, 77: 191-208)

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