Method for separation and extraction of 1, 3-propylene glycol and its byproducts from fermentation liquid

Abstract

The present invention discloses a process for separation and extraction of 1,3-propylene glycol by fermentation method, which belongs to biochemical separation technical field. A rectification is carried out to separate alcohol in the fermentation liquor, then solids and dissolved protein are separated from the fermentation liquor by composite flocculation of cation type flocculant and non-ion type flocculant. The pH value of the obtained clear liquid is regulated by an acid, and an extraction is performed with an aldehyde. An aldolisation between 1,3-propylene glycol, 2,3-butanediol, glycerine and an aldehyde is carried out to obtain a cyclic acetal to be separated from water phase, salts and other solubility impurity are separated from 1,3-propylene glycol, 2,3-butanediol and glycerine along with the water phase. The acetal hydrolysis applies reacting rectification with solid acid catalyst, can obtain high concentration 1,3-propylene glycol, 2,3-butanediol and glycerine mixture, which is separated again by subsequent common rectification. Excessive aldehyde in the extract phase is recovered by rectification. The invention has the advantages of simple extraction and separation process, low energy consumption, high product recovery, less equipment investment and less land occupation.

Description

technical field [0001] The invention belongs to the technical field of biological separation, in particular to a method for separating and extracting 1,3-propanediol and its by-products from fermentation liquid. Background technique [0002] 1,3-propanediol (1,3-Propandiol, referred to as PDO) is a monomer for the production of polytrimethylene terephthalate (PTT). In the literature "Smith, J.G.Polym.Sci., Part A-1.1966, 4, 1851-1859 "Preparation and properties of poly (methylene terephthalates)" and "Witt U, et al J, Makromol Chem Phys, 1994, 195 : 793~802, "Synthesisproperties and biodegradability of polyesters based on 1,3-propanediol"" reported that PTT is a biodegradable polyester material used in advanced textile materials. Compared with polyethylene terephthalate (PET) and polybutylene terephthalate (PDT), the odd number of carbon atoms in 1,3-propanediol gives PTT special properties. The current PDO production methods mainly include the acrolein method and the ethy...

AI Technical Summary

Problems solved by technology

[0011] For the above-listed method for extracting 1,3-propanediol from fermentation broth, 1,3 methods have the disadvantages of large energy consumption and consumption of a large amount of organic solvents; the method in 2,4 has poor industrial feasibility; the method in 5 Formaldehyde and acetaldehyde have low boiling points, and are easy to form polymers, which is difficult to recover, and the use of organic solvents such as benzene is more toxic; 6. The electrodialysis desalination of 1,3-propanediol has a large loss, high equipment costs, and a large area.

All the extraction methods listed above do not have a complete process for extracting and separating 1,3-propanediol, glycerol, and 2,3-butanediol from the fermentation broth