CN1039434C

CN1039434C - Method for digesting & extracting glycerin from fermentation liquid

Info

Publication number: CN1039434C
Application number: CN 94112180
Authority: CN
Inventors: 蔡水洪; 张平; 张秋华; 骆赞椿
Original assignee: East China University of Science and Technology
Current assignee: East China University of Science and Technology
Priority date: 1994-05-27
Filing date: 1994-05-27
Publication date: 1998-08-05
Anticipated expiration: 2014-05-27
Also published as: CN1100465A

Abstract

The present invention discloses a method for digesting and extracting glycerol from fermentation liquid. Heat sensitivity substances of reducing sugar, oligosaccharide, polysaccharide, protein, amino acid, etc. are removed from the fermentation liquid by the digestion action of a solvent; then, glycerol is extracted by a fractionating method; the yield of the glycerol can reach more than 95%.

Description

The method of digesting ﹠ extracting glycerin from fermented liquid

The present invention relates to a kind of separation method and industrial application thereof of chemical engineering.

As everyone knows, in chemical industry production, often run into isolating method separation and Extraction useful matter from the aqueous solution of utilization chemical engineering, for example, extraction process commonly used, ion exchange method, distillation method etc.But for the more special fermentation system of a class, these methods often are difficult to gather effect again.How just to have run into a difficult problem of extracting glycerine in the fermented liquid from " fermentative Production glycerine " (be called glycerol fermented broth traditionally or be called for short fermented liquid, down with) as industrial; Relevant monograph: just record " separation and Extraction glycerine is quite difficult from the fermented liquid of fermentative Production glycerine " as (sec, III, P7) in " The ManufactureofGlyceral " book that GMartin showed clearly; P.kishore etc. are at " Concentration ofglyceroe in fermentation broths by reverse osmosis " (J.Microb.Biotechnol, 1987,2 (1) 22～27) also think in the literary composition that extracting glycerine from glycerol fermented broth is that fermentation method is produced glycerine " bottleneck problem ", and propose the possibility that the employing reverse osmosis method is situated between and determines; In the data aspect relevant fermentation, also generally believe: " extracting glycerine from glycerol fermented broth is the gordian technique that fermentative Production glycerine need be situated between and determine, and relates to the industrial prospect of this method ".The fact also is so, and is industrial at present, extracts glycerine and suffer from not having good plan always from fermented liquid, has to continue to use traditional distillation separation method.But owing to contain many heat-sensitive substances in this fermentation system, produce serious coking in still-process, cause the yield of glycerine very low, starting material are wasted in a large number.Therefore branch of industry wishes that urgently the middle scientific worker of field of chemical engineering provides a kind of new isolation technique as soon as possible, to support fermentative Production glycerine industrial expansion.

The contriver finds after by the analysis-by-synthesis to the whole process of fermentative Production glycerine technology: with starch or molasses is fermenting raw materials method when producing glycerine, always has part glucose not fermented, and remains in the fermented liquid; Impurity such as the oligose that contains in the saccharification liquid, polysaccharide and protein, and the by products such as amino acid that generate during the fermentation all are present in the fermentation liquid.Therefore, in glycerol fermented broth, except containing product glycerine, also must contain impurity such as a certain amount of reducing sugar and oligose, polysaccharide, protein, amino acid.The existence of this class material has brought great difficulty to separation and Extraction glycerine from glycerol fermented broth.This is because impurity such as residual reducing sugar and oligose, polysaccharide, protein, amino acid in the fermented liquid, all are type of thermosensitive materials, in still-process, produced serious coking by charing, glycerine is adsorbed is wrapped in the coke, can't be distilled out, some glycerine be carried to be come out yet when serious.But along with the development of human material progress, people's expectation obtains clean bionic goods---from the glycerine of fermentative Production.Therefore, solve the technology of from fermented liquid, extracting glycerine and become the task of top priority.

Purpose of the present invention is exactly a difficult problem that is faced at fermentative Production glycerine, on the basis of a large amount of experiments, a kind of dissolved separation method has been proposed, it can extract glycerine effectively from fermented liquid, the glycerine yield is reached more than the 95%wt, thereby satisfied the needs of branch of industry.

Design of the present invention is such:

Nationality help a class and glycerine to dissolve each other fully and with the dissolved effect of the immiscible single hydroxyl alcohol kind solvent of impurity, earlier reducing sugar, oligose, polysaccharide (being referred to as sugar), protein, amino acid impurity such as (general designation nitrogenous substancess) remaining in the glycerol fermented broth are given precipitate and separate and removes, obtain a kind of more purified " glycerine-water-single hydroxyl alcohol " supernatant liquor, and then glycerin extraction is come out with fractionating process.

The present invention also is implemented in like this:

Glycerol fermented broth and solvent single hydroxyl alcohol are mixed according to a certain percentage, wherein glycerine and single hydroxyl alcohol and water form the liquid phase of homogeneous, and impurity such as residual reducing sugar, oligose, polysaccharide, protein, amino acid are removed by clarification or centrifugation owing to be insoluble to single hydroxyl alcohol and precipitated separating out in the fermented liquid.Remaining supernatant liquor is a kind of aqueous solution that contains glycerine, single hydroxyl alcohol, then supernatant liquor is sent into separation column and is obtained glycerin liquid respectively and reclaim the solvent single hydroxyl alcohol.Glycerin liquid is again through distilling refining glycerol product, reclaims single hydroxyl alcohol and returns the dissolved separator recycle after manipulation of regeneration.

Ratio of mixture between fermented liquid and the solvent is 1: 1～6, should get: 1: 1.5～3.5.Ratio of mixture is little, and the decreasing ratio of sugar and nitrogenous substances is low, and ratio of mixture is big, the decreasing ratio height of sugar and nitrogenous substances, but the consumption of solvent is excessive, and the loss of solvent (consumption) also may increase.The dissolved sepn process can be carried out under 0-40 ℃ of normal pressure, but in order to reduce the loss of solvent, should carry out under lower temperature, carries out between 0～20 ℃.Consider industrial convenience, the dissolved sepn process can be carried out under normal pressure, room temperature.

Under normal pressure, the room temperature, in the scope of ratio of mixture 1: 1～6, the decreasing ratio of impurity in the glycerol fermented broth (comprising reducing sugar, oligose, polysaccharide, protein, amino acid etc.) can reach 98% (wt) more than 90% (wt).Only have a spot of sugar and nitrogenous substances (＜0.3%wt) remain in the supernatant liquor, but it has been not enough to influence the carrying out of fractionation process.

The present invention said from fermented liquid the method for digesting ﹠ extracting glycerin, its technological process is as shown below:

In a dissolved separator, will from the fermentation workshop section fermented liquid carry out thorough mixing with the single hydroxyl alcohol of solvent feed tank, dissolved is separated.The supernatant liquor that produces enters separation column, extracts glycerin liquid respectively and reclaims the solvent single hydroxyl alcohol; Throw outs such as the reducing sugar that produces, oligose, polysaccharide, protein, amino acid then enter in another distiller, behind the solvent single hydroxyl alcohol that the distillation recovery is wherein carried secretly, throw out returns sugaring again, fermentation workshop section proceeds fermentation, to improve utilization ratio of raw materials.Recovered solvent is combined after manipulation of regeneration, return solvent feed tank, recycle.

Said solvent is that a class has general formula C _nH _mThe single hydroxyl alcohol of OH, n=1-5 wherein, m=2n-1,2n, 2n+1 should be selected from following material: methyl alcohol, ethanol, Virahol, n-propyl alcohol, one or more in the trimethyl carbinol, propyl carbinol, tertiary amyl alcohol, the Pentyl alcohol.

Said fermented liquid wherein glycerol content scope is 5-20%wt, but in order to reduce the consumption of solvent as much as possible, when entering the dissolved separator, glycerol fermented broth should be concentrated in advance, makes glycerol content wherein reach 30～80%, but with 40%-60% (wt) with suitable.

Further illustrate content of the present invention below in conjunction with embodiment, but these embodiment do not limit protection scope of the present invention.

Embodiment 1

In a dissolved separator, add the 1086 gram trimethyl carbinols and 400 gram fermented liquids (wherein glycerol content is 42%wt, and reducing sugar content is 4.8%wt), at room temperature stirred 30 minutes, static, settlement separate, obtain throw out 145 grams, supernatant liquor 1341 grams.After throw out reclaims the solvent of wherein carrying secretly through distillation, be back to sugaring, the continuation fermentation of fermentation workshop section; Supernatant liquor enters separation column with the recovery solvent, and obtains glycerin liquid 255 grams.Glycerol content is 62.7% (wt) in the glycerin liquid, and reducing sugar content is 0.8% (wt).The decreasing ratio of reducing sugar is 90%, and other impurity removal percentage is more than 95%.The yield of glycerine is 95% (wt).Reclaim solvent after manipulation of regeneration, obtain the regenerated solvent trimethyl carbinol 1053 grams, the rate of loss of solvent is 3%.

Embodiment 2

In a dissolved separator, adding 2292 gram propyl alcohol and 1000 gram fermented liquids (its concentration is with embodiment 1) at room temperature mixed 30 minutes, after centrifugation, obtained throw out 180 grams, supernatant liquor 3112 grams.Supernatant liquor obtains glycerin liquid 612.1 grams after distillation removes propyl alcohol, wherein glycerol content is 65.6% (wt), and reducing sugar content is 0.8% (wt), and the yield of glycerine is 95.4% (wt).Throw out returns sugaring, the continuation of fermentation workshop section as the raw material that ferments behind the distillating recovering solvent propyl alcohol, the decreasing ratio of reducing sugar is 89.8%, and the decreasing ratio of other impurity is 95%.Reclaim solvent after manipulation of regeneration, obtain regenerated solvent propyl alcohol 2228 grams, the rate of loss of solvent is 2.8%.

Embodiment 3

In a still kettle, add as glycerin liquid 500 grams of embodiment 2 gained, under the 750mmHg vacuum, distill refiningly, obtain distillate 483 and restrain, wherein glycerol content is 64.8% (wt).Product is purified glycerin liquid.The yield 95.4% of glycerine.

Comparative Examples

Get glycerol fermented broth 500 grams of handling without the dissolved method, wherein glycerol content is 42.1% (wt), and glucose content 4.8% (wt) places a still kettle, with implement 3 identical conditions under carry out vacuum distilling.Obtain distillate 210 grams, wherein only contain the glycerine less than 20% (wt), form a large amount of cokings in the still kettle, glycerine is wrapped in the inside, can't distillate, so the yield less than 20% of glycerine.

By embodiment 3 and Comparative Examples as seen:

Adopt method of the present invention, behind the impurity such as reducing sugar, oligose, polysaccharide, protein, amino acid, the extraction yield of glycerine is improved greatly in the deglycerizin fermented liquid.Make fermentative Production glycerine that the favorable industrial development prospect arranged.

Claims

1, a kind of from fermented liquid the method for digesting ﹠ extracting glycerin, this method comprises dissolved, centrifugal or refining four steps of clarification separation, fractionation and distillation, wherein said dissolved ties up under the following processing condition carries out:

Under room temperature, normal pressure, at first handle the fermented liquid that contains glycerine with the alcoholic solvent dissolved, make wherein contained heat-sensitive substance precipitation, separate disgorging through centrifugal or clarification then, obtain the purified aqueous solution that contains glycerine-alcoholic solvent;

Said alcoholic solvent is a kind of in methyl alcohol, ethanol, Virahol, n-propyl alcohol, propyl carbinol, Pentyl alcohol, the tertiary amyl alcohol;

The fermented liquid that contains glycerine is 1: 1～6 with the ratio of alcoholic solvent.

2, the method for claim 1, the fermented liquid that it is characterized in that containing glycerine is concentrated in advance before dissolved is handled, and makes that glycerol content reaches 30～80%wt in the fermentation.

3, the method for claim 1, the fermented liquid that it is characterized in that containing glycerine is concentrated in advance before dissolved is handled, and makes that glycerol content reaches 40～60%wt in the fermented liquid.

4, the method for claim 1 is characterized in that the said fermented liquid that contains glycerine and the ratio of alcoholic solvent are 1: 1.5～3.5.