CZ354590A3 - Method for continuous treatment of molasses produced during fermentation and distillation of biological materials - Google Patents

Description

Technical field

The invention relates to a process for the continuous processing of stillage. produced during fermentation and distillation. biological materials such as corn, wheat and other grains, sugar cane, sugar beet, grapes and other fruits, potatoes, cassava, sugar sorghum and others. This process can produce glycerin, betaine, succinic acid and / or lactic acid, potassium sulfate and L-pyroglutamic acid. In obtaining said substances, fermentation and distillation of certain suitable raw materials are utilized to produce ethanol and distillers from which free-flowing dry distillery milk or solid fertilizer is produced.

BACKGROUND OF THE INVENTION

The production of each of the aforementioned products by other methods is currently known and the individual methods of making said products are commercially used. Ethanol is used as a beverage, chemicals and fuel and is usually produced by fermentation and distillation processes, starting with biological materials such as corn, wheat and other grains, sugar cane or sugar beet, grapes or other fruits and potatoes. Although j e_známo_, _že ________ ₌ glycerol formed in small quantities as a byproduct in an ethanol fermentation and distillation processes or in the production of yeast or yeast extract, commercially glycerin hitherto produced only processes in which the primary product obtained by soap or in which glycerin is synthesized from petrochemical raw materials. Betaine is usually produced synthetically or by crystallization of aqueous solutions of beet molasses. Succinic acid is usually synthesized from maleic acid or acetic acid or is produced by a highly specifically conducted fermentation process. Typically, lactic acid is produced by fermentation using Lactobacillus delbrueckii, B. dextrolacticus, or similar microorganisms. Potassium sulphate is usually obtained by reacting sulfuric acid with potassium chloride,

Potassium chloride is usually found in nature as a sylvine or sylvite mineral.

Distillery dry grain, characterized as soluble grain (DDGS) or soluble grain (DDG), is usually obtained as a by-product of fermentation and distillation processes. The DDG or DDGS distillery grains are usually soaked in sticky byproducts, particularly glycerin, so that the grains do not have a free-flowing character and are very difficult to handle.

If the substrate from which the distillate is made is sugar cane or sugar beet, then the residue obtained is used only as a liquid fertilizer or feed additive, or the residue is only unusable waste.

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The production of ethanol is well known and the procedures for preparing ethanol are well described in the relevant literature available in the prior art. For example, the production of glycerin is described in U.S. Patent No. 2,160,245 to Hildebrandt or U.S. Patent No. 2,772,207.

Some suggestion that glycerin can be obtained more economically from distillers' shampoo is contained in: Burriss, Recovery of Chemical Such as Glycerol Dextrose, and Amino Acids from Biluts Brotks ), which was presented at the International Conference on Fuel, Alcohols and Chemical from Biomass, held December 10-12, 1986 in Miami Beach on the “Ftorid — Designed” Way — Obtaining — gl-yceria-including a precise sequence of operations including ultrafiltration (on an organic membrane with a pore size of less than 0.1 micrometer), pH adjustment, filtration, ion selective treatment, ion exchange process, and activated carbon treatment. However, this demanding sequence of precisely conducted operations is not a commercially acceptable process for the production of glycerin.

Betaine production is described, for example, in U.S. Patent No. 4,359,430 (Heikkila et al.) And Japanese Patents JP 51/039625 and JP 80/045067. Thus, although the production of betaine from beet molasses is a known commercially acceptable method of obtaining betaine, as is apparent from the aforementioned patents, it is not yet known to produce betaine from distillery stillage. The reason for this is a significant clogging of the chromatographic resin with yeast, microorganisms and other compounds present. The process for the production of glycerin, betaine, succinic acid and free-flowing distillery dry grains or the production of betaine and glycerin from beet molasses stillage by the method according to the invention is not known or known from any prior publication.

SUMMARY OF THE INVENTION

The essence of the method of continuous processing of stillage produced during fermentation and distillation of biological materials from the group comprising maize, wheat and other cereals, sugar cane, sugar beet, grapes and other fruit, potatoes, cassava, sugar sorghum and others, wherein said biological materials are prepared , the mash is fermented with yeast and then distilled to form ethanol and said stillage, the process comprising the following steps:

(a) clarifying stillage comprising cross-microfiltration using inorganic membranes from the group comprising ceramic and mineral membranes having a pore size in the range of 0.1 to 10 gm; (b) subjecting the clarified stillage to a first chromatographic separation in which the clarified stillage is ion-selective a column for separating the glycerol and betaine in the form of a mixture from the other components of the clarified stillage, (c) subjecting the mixture of glycerol and betaine to a second chromatographic separation in which the mixture is passed through a second ion selective column in which glycerol is separated from betaine; purification of the glycerol and betaine thus separated.

In a preferred embodiment, the fermentation, distillation, clarification, chromatographic separation and purification steps also form part of a continuous process.

In a preferred embodiment, the clarification step further comprises an initial centrifugal separation of the solids from the liquid components before subjecting the stillage to microfiltration.

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Said transverse microfiltration is preferably performed with an alpha-alumina-based membrane unit having a pore size of 0.2 μπι.

The clarified stillage from step (a) is preferably preferred

Enzymatic-process-to-hydrolyzate-protein-______

About the material.

It is also preferred that the permeate from the microfiltration step is concentrated prior to passing this portion by the ion selective material to a concentration of solids as high as possible, most preferably the permeate is concentrated to a concentration of 50-75% solids and the resulting potassium sulfate crystals are removed.

Said first chromatographic separation step is preferably performed according to the invention using a strong acidic cation exchange resin in potassium form with a mean particle size of about 375 microns and a moisture retention capacity of about 52.5%. The proportion of glycerol / betaine from the first chromatographic separation step is preferably concentrated to about 75% by weight before being fed to the second chromatographic separation step.

Said second chromatographic separation step is carried out in a vacuum. preferably carried out using a polystyrene strong base anion exchange gel resin in sulfate form with a mean particle size of about 350 microns and a moisture retention capacity in the range íTbd ^ ^- ^! This includes draining said clarified stillage into a chromatographic separation system comprising a strong acidic cation exchange resin in calcium form with a mean particle size of about 350 microns and a moisture retention capacity ranging from 57.5 to 61.0%.

In the process according to the invention, the proportion of glycerols is purified by ion exchange, evaporation to a concentration of 80 to 85% glycerols, further distillation to almost pure glycerol and refining to ultra-pure glycerol. The glycerol fraction and the betaine fraction originating from the second chromatographic separation step are each preferably ion exchanged, further concentrated and purified by distillation and refining to glycerol and crystallized to betaine hydrochloride and betaine.

According to the invention, it is now possible for the first time to obtain betaine and / or glycerin from stillage originating from a fermentation process of ethanol production in which sugar beet derivatives have been used as the basic starting material. The decisive steps are the feed preparation by microfiltration and two chromatographic separation steps performed to produce glycerine and betaine. Cross microfiltration using inorganic membranes followed by hydrolysis of the proteinaceous material and / or removal of potassium sulfate crystals in the passing fraction (if desired) yields very well clarified stillage. The clarified stillage thus obtained can now be concentrated to a very high solids content for further processing in two separation chromatographic steps, each of which is carried out on its own specific resin, in which two chromatographic separation stages yield two eluates containing of highly pure glycerin and betaine.

The newly proposed process according to the invention has several advantages over the hitherto known processes described in the aforementioned patents, which consist in particular in energy and process water savings, reduced operating costs and very high dry solids concentrations as well as very high dry solids concentrations. High-glycerine and betaine. . .

The process according to the invention and the apparatus for carrying out the process can be used either for the production of each of said products alone or for the production of all said products, or for the production of any combination of these products in fermentation and distillation or similar processes.

According to one aspect of the present invention, glycerine is continuously obtained from stillage produced by fermentation and distillation of biological materials such as corn, wheat and other cereals, sugar cane, sugar beet, grapes and other fruits, potatoes, cassava, sorghum, cheese whey and others to obtain ethanol and said stillage comprising the steps of:

(a) clarification of stillage by subjecting the stillage to transverse microfiltration using inorganic membranes having a pore size in the range of 0.1 to 10 micrometers; (b) guiding the clarified stillage through ion selective material for the purpose of chromatographic separation of glycerin ^- from others and (c) purifying the separated glycerin.

• *

This process is preferably characterized in that the clarification stage of the stillage further comprises an initial centrifugal separation of the solids from the liquid components before said stillages are subjected to microfiltration.

This process is further advantageously characterized in that, as the material from which the stillage is obtained, it is obtained. the diabetic stillage from step (a) is enzymatically processed to hydrolyze the proteinaceous material.

Further, the process is advantageously characterized in that sugar is used as the stillage material, the clarified stillage is concentrated to a dry matter content of 50-7% and the resulting potassium sulfate crystals are removed.

Further, the process is advantageously characterized in that the fraction passing from the microfiltration step is concentrated to as high a dry matter concentration as is desired prior to passing the fraction through said ion-selective material.

The process is further preferably characterized in that said purification step comprises ion exchange, evaporation to a glycerin concentration in the range of 80 to 85%, further distillation to obtain almost pure glycerin and refining to obtain ultrapure glycerin.

Another aspect of the present invention is a process for obtaining the abovementioned stillage comprising the steps of:

(a) preparing the mash from biological materials, (b) fermenting said mash using a sufficient amount of yeast to obtain a fermented mash containing at least about 9 grams, elycerin and 40 grams of ethanol per 100 grams per minute of mash reducing sugar; and (c) distilling the fermented mash to separate the ethanol from the mash and recover said stillage.

This process is preferably characterized in that said yeast comprises immobilized yeast cells.

Further, the process is preferably characterized in that said step of fermenting the mash comprises admixing the yeast to said mash in an amount greater than 100 grams per liter of mash.

Further, the process is preferably characterized in that said spin is prepared to have a dextrose equivalent of at least about 80.

Also, the process is preferably characterized in that the pH of the mash is maintained substantially stable during the first two-thirds of said fermentation process.

Further, the process is preferably characterized in that the fermentation of said mash comprises the addition of yeast in an amount such that a fermented mash containing at least 15 grams of glycerin and 40 grams of ethanol per 100 grams of reducing sugar in the mash is obtained.

Further, the process is advantageously characterized in that the graphical separation of the glycerol and the purification of the separated glycerol are carried out continuously.

A further aspect of the present invention is a process for the continuous recovery of glycerin and betaine produced in the fermentation and distillation of sugar beet to obtain ethanol and the stillage comprising the steps of:

(a) clarifying said stillage by subjecting said stillage to transverse microfiltration using inorganic membranes having a pore size in the range of 0.1 to 10 microns; (b) first chromatographic separation of said stillage by means of guiding the clarified stillage through an ion selective column (c) a second chromatographic separation of the glycerin and betaine mixture by passing said mixture through a second ion selective column in which the glycerin is separated from betaine and (d) purifying the separated glycerin and betaine.

Said process is preferably characterized in that said clarification further comprises an initial centrifugal separation of the solids from the liquids prior to the stillage being subjected to microfiltration.

Also, the process is preferably characterized in that the clarified stillage of step (a) is enzymatically processed to hydrolyze the proteinaceous material.

Furthermore, the process is advantageously characterized in that the clarified stillage is concentrated to a dry matter content of 50 to 7%. then the resulting potassium sulfate crystals are separated.

This process is also preferably characterized in that the glycerin-betaine stream from the first chromatographic separation is concentrated to about 75% by weight before the stream is introduced into the second

----------- chromatographic-separation separator. . Further, the process is preferably characterized in that the glycerine stream and the betaine stream leaving the solid-phase chromatography step are separately subjected to an ion exchange, further concentration and purification by distillation and refining to obtain glycerin and crystallization to obtain betaine hydrochloride or betaine.

Also, the process is preferably characterized in that the passing fraction from the clarifying stage is subjected to crystallization to form potassium sulfate and passing fractions containing glycerin and betaine, which is introduced into the first chromatographic separation stage.

This process is further preferably characterized in that said first chromatographic separation essentially divides glycerin and betaine into the first stream and other products including at least one of succinic acid, lactic acid and acid.

L-pyroglutamic to the second stream, the second stream being subjected to further chromatographic separation steps to separate one of said products, any combination of these products, or all of said products from the remainder.

Furthermore, the process is advantageously characterized in that said fermentation, distillation, clarification.

The continuous process.

Another aspect of the present invention is a process for continuously obtaining at least two products from the group consisting of glycerin, betaine, succinic acid, lactic acid and L-pyroglutamic acid from stillage produced during fermentation and distillation of biological materials such as corn, wheat and other cereals, sugar cane, sugar beet, grapes and other fruit, potatoes, cassava, sugar sorghum, cheese whey and others, in which ethanol and stillage are obtained, comprising the steps of:

(a) clarifying the stillage obtained in the distillation of fermented mash by subjecting the stillage to a cross-microfiltration treatment using inorganic membranes having a pore size ranging from 0.1 to 10 micrometers (b) passing the clarified stillage through a series of ion-selective columns for physico-chemical separation of each product from the other components of the clarified stillage and (c) purifying the separated product.

Said process is preferably characterized in that diabetes is used as the material from which the stillage is obtained, wherein the clarified stillage from the step a / enzymatically is processed to hydrolyze the proteinaceous material.

This procedure is further preferably characterized in that as the material from which the stillage obtained is used sugar beet, the clarified vinasse ₌ přičemž.se concentrated to a dry matter content of 50-75%, whereupon the resulting potassium sulfate crystals are removed.

Characteristic products obtained in these processes are glycerine produced by the above process, glycerine and betaine produced by the process of the invention, glycerine, betaine and potassium sulfate produced by the process of

Glycerin betaine and L-pyroglutamic acid produced by the process of the invention, and glycerin and one product from the group consisting of betaine, succinic acid, lactic acid and glycerine. L-pyroglutamic acid, produced

by a process according to the invention wherein these products represent another aspect of the present invention

Another aspect of the present invention is a continuous process for obtaining betaine from beet stillage obtained in fermentation and distillation of sugar beet to obtain ethanol and said beet stillage, comprising the steps of:

(a) clarifying said stillage obtained in the distillation of fermented beet pulp by subjecting said stillage to cross-microfiltration using inorganic membranes having a pore size ranging from 0.1 to 10 microns; (b) subjecting the clarified stillage to chromatographic separation by introducing the clarified stillage into selective columns for separating betaine from other components of clarified stillage and (c) purifying the separated betaine.

This process is preferably characterized in that it further comprises an initial centrifugal separation of the solids from the liquids prior to the slurry being subjected to microfiltration.

-Rťwměř- je. this process is preferably characterized in that the clarified stillage from the step a / enzymatically is processed to hydrolyze the proteinaceous material.

Further, the process is preferably characterized in that the clarified stillage is concentrated to a dry matter content of 50 to 75%, after which the resulting potassium sulfate crystals are removed.

The process is further advantageously characterized in that the fraction passing from the microfiltration step is concentrated to a concentration as high as dry matter desired before introduction of said fraction through said ion-selective material.

Said process is further preferably characterized in that the degree of purification of the separated betaine comprises ion exchange steps, evaporation to a glycerine concentration of 80 to 8%, further distillation to form almost pure glycerin and refining to form ultra-pure glycerin.

Also, the process is preferably characterized in that clarification, chromatographic separation and purification are part of a continuous process.

As mentioned above, one of the main objectives of the present invention is to produce glycerin as a valuable co-product in a fermentation process, in particular an ethanol-producing fermentation process. In realizing this goal by the process according to the invention, the efficiency of the known ethanol-producing fermentation and distillation processes is maintained and, moreover, is maintained. yet another valuable product is obtained. _ ........ ..... '__ ..

Ethanol production is carried out according to known and widely published biological reaction schemes. In the process according to the invention, this known biological reaction scheme of up to 1δ is directed to improve the formation of glycerin and / or other by-products and to achieve this improved production with relatively little or no reduction in the efficiency of the ethanol production process alone.

It is therefore apparent from the foregoing that a further object of the invention is to obtain betaine or betaine hydrochloride / L-pyroglutamic acid as a co-product or co-products of a fermentation process starting from a substrate consisting of diabetes or the like.

It is a further object of the present invention to provide lactic acid and other carboxylic acids in said fermentation processes, such as, in particular, wet ground corn fermentation or some wine fermentations, wherein the lactic acid is produced in significant amounts. It is also an object of the present invention to produce dry distillate grains with or without soluble fractions or solid fertilizer premixes in a fermentation-distillation process, these products being free of tacky by-products so that they are free-flowing and easy to handle.

Most commonly, the fermented spin is distilled in a stripping column, whereby the evaporated ethanol is withdrawn from hlaOr. MtíQs v.,

this stripper column. The remaining stillage is then clarified by centrifugation (if necessary) followed by microfiltration. A microfiltration step in which particles of a size ranging from 0.1 to 10 microns is separated from the stillage is a key step for obtaining glycerin, betaine and by-products in economically acceptable amounts. Earlier attempts (Burris) to obtain glycerin suggested ultrafiltration (separation of particles smaller than 0.1 micron) in combination with other processing steps. However, due to fouling of the ultrafiltration membranes, only an insufficient amount of glycerin was obtained and the process thus conducted was not economically acceptable.

The unexpected effect of microfiltration using inorganic membranes is that the stillage is well clarified and the subsequent isolation of by-products such as glycerin yields these by-products in improved yields, resulting in the isolation of these by-products in fermentation-distillation processes.

- commercially acceptable for the first time. - '' - ™ ™

Depending on the nature of the feedstock, the separated clarified liquid is subjected to further refining treatment (if desired), concentration, enzymatic hydrolysis of the protein material, removal of potassium sulfate crystals, one or more chromatographic separation steps (using different resins in the feed). It is believed that more than one separation step is used to concentrate and ultimately purify glycerin, betaine, L-pyroglutamic acid, succinic acid, lactic acid, and / or potassium sulfate, obtained in economically acceptable amounts. In addition, the resulting products are devoid of sticky by-products and are therefore free-flowing and easy to handle.

In the attached drawings:

Fig. 1 shows schematically a flow diagram of a method according to the invention and

Fig. 2 shows schematically a similar flow diagram to that shown in Fig. 1, except that this figure shows a process for obtaining glycerin and betaine according to the invention.

While the invention will be described in more detail below with reference to the accompanying drawing, in which a preferred embodiment of the method according to the invention is shown, it will be understood that one skilled in the art will be able to modify the embodiment described herein while still achieving favorable results. according to the invention. Accordingly, it is _? The following description is a more general guide intended for persons having a certain professional qualification in the field covered.

1 shows schematically the individual steps of the process according to the invention and the apparatus necessary for carrying out the process. Some of the steps and parts of the device are well known to those skilled in the art and are therefore not shown in detail here but will be described in more detail in the following description.

It is known that the formation of ethanol in a fermentation process using yeast or other microorganisms is associated with the growth of these microorganisms, with the formation of glycerin and succinic acid having a certain relationship to alcohol formation. According to the Embdem-Meyerhof scheme, the rate of formation of NADH from the triosphosphate oxidation exceeds the rate of acetaldehyde. Inhibition of normal glycerol is demonstrated when a cell having ATP deficiency from glycolysis converts excess NADH into a reduction of dihydroxyacetone phosphate to glycerin. An additional amount of NADH is supplied by the Krebs cycle of citric acid. The abbreviations NADH and ATP used herein refer to nicotinamide adenine dinucleotide and adenosine triphosphate.

When konvenčníjs well maintained fermentation process ---------- b _e2 - _Rec yjQ _Ov EXII-stillage with ^ - of ^- TOO- ^"_ grams of reducing sugar consumed-create about 48 g of ethanol, 4 g of glycerol, 0 , 6 grams of succinic acid and a small amount of lactic acid = Producers of ethanol using as a raw material wet ground maize get significant amounts of lactic acid in fermented flint, which is also achieved in wine and other fermentation processes ·

Regardless of which feedstock is used in the fermentation process, a fermented alcoholic wound is prepared using yeast and / or other microorganisms. It must first be determined whether the fermentation target is to increase the production of glycerin and / or succinic acid, since it is then necessary to regulate the fermentation process in a certain way. During succulent growth, succinate formation is high, but succinate formation is low during anaerobic fermentation. Accordingly, variations in cell growth during the fermentation process allow some control of the glycerin / succinic acid ratio in the resulting fermented mash. '‘

Furthermore, depending on the feedstock and / or the fermentation conditions used, betaine may be present

- 23 L-pyroglutamic acid, lactic acid and other carboxylic acids isolated in economically acceptable amounts.

Regardless of which feedstock has been fermented in the first stage, the fermentation is followed by a distillation, which is preferably carried out in a stripping column, the vapors of evaporated ethanol being drawn off at the top of the stripping column. The residue at the bottom of the stripper or stillage contains either all of the aforementioned by-products or at least a part of these by-products. Further processing of these distillery stillage depends on which by-products are to be obtained from the stillage.

Regardless of the by-product to be obtained, the distillation process is followed by a clarification process which can be started by pre-centrifugation in combination with or without chemical treatment. In some cases, a protease or proteases (protein-digesting enzyme) is added as part of said pretreatment to break down peptides and proteins that would otherwise clog the filter membranes in the next step. After this optional pretreatment, the stillage is passed to a transverse microfiltration step using inorganic membranes.

This microfiltration, which is defined on another

The 24-site description as subjecting the stillage to a cross-microfiltration using ceramic or inorganic membranes having a pore size ranging from 0.1 to 10 microns, dividing the stillage into a passing portion and the gage-tag is the degree that It is critical for producing clarified stillage and obtaining the above by-products in economically acceptable quantities.

The abovementioned retained fraction is fed to a plant for the production of fertilizers or animal feed. Depending on the feedstock used, the passing portion of the microfiltration can be purified to prevent clogging of the chromatographic separation resins listed below. The passing parts are then concentrated to the highest possible dry matter content (50-75%).

The thickened passing portion is then either directly subjected to chromatographic separation (to pre-obtain either glycerin, betaine, succinic acid, L-pyroglutamic acid or lactic acid) or first crystallized. (in order to separate and refine the potassium potassium from beet stillage). If glycerine is to be a by-product, then the chromatographic separation is ion exclusion followed by ion exchange, evaporation to a glycerine concentration of 80 to 85%, by distillation to

- obtaining almost pure glycerin as well as refining to obtain ultra-pure glycerin.

The by-product stream from the above chromatographic separation step is led to processing into animal feed or to a second separation step, which may include chromatographic (to obtain betaine if the starting material is diabetes) and / or physicochemical separation to obtain acid succinic acid, lactic acid, L-pyroglutamic acid and / or betaine (if the starting material is diabetes). In the case of a process using wet ground corn as the starting material, it is possible to obtain lactic acid in an economically acceptable manner in this very second chromatography step. Betaine as well as L-pyroglutamic acid can be obtained in the same way when diabetes is used as the starting material. In this case, the first chromatographic separation provides glycerin and betaine. These products are then separated in a second chromatographic step, whereupon each of the two products is purified, concentrated and refined. With the exception of betaine, sugar cane is used to produce the same products as sugar beet.

The first process parameter affecting the improved production of glycerin and / or succinic acid during fermentation is the yeast itself used in the fermentation process. It was found that. Suitably, the immobilized microorganisms improve and increase the production of glycerin and succinic acid. Increased production of said products is achieved when yeast is used in high-density stabio-1-ηϊ-matrix, as illustrated in the following example.

Example 1

The buffet prepared from whole ground corn is subjected to a jet mandate for two minutes at 149 ° C and then liquefied at pH 6.3 to dextrose equivalent (DE / 20.3) and saccharified to DE 36 at pH 4.5 · Immobilized yeast is prepared by mixing a 1.5 weight percent solution of sodium alginate with a preferred ratio of hydrated yeast to sterilized sand. The resulting slurry was poured through a 12 mesh screen into an aqueous solution of 0.5 M calcium chloride and 1.5% glucose at pH and ambient temperature. Upon contact with the calcium chloride solution, the droplets of the slurry form beads which, after 24 hours in a refrigerator at 4 ° C, gelatinize to form solid beads with a diameter of 2-4 mm.

The mash is then fermented in two batches at 34 ° C using both free and immobilized yeast at a concentration of> 0 grams per liter.

The fermentation is carried out in batches without recycle of the stillage at pH 5.0, which is adjusted using sodium hydroxide. In the following Table 1 the two fermentation batches are compared with respect to the yields of glycerin and succinic acid.

Table 1

Glycerin Succinic acid / grams / 100 grams of reducing sugar /

Loose yeast 3.38 0.67

Immobilized yeast 4.09 0.87

Other parameters that must be controlled in the process of the invention are yeast concentration and DE or carbohydrate concentration. When yeast and carbohydrate concentrations increase, the production of glycerin and succinic acid also increases. This is demonstrated in the following example 2.

The mash is prepared from whole ground maize and fermentation is started at pH 4.9 and DE 27 using free yeast and a temperature of 33 ° C. The fermentation is carried out in batches without recycle of stillage. Table 2 summarizes the results (yields of glycerin and succinic acid) for different yeast concentrations and different DE.

Table 2

Concentration DE Glycerin _______ Amber yeast acid / grams / 100 grams reducing per 10 ⁶ ml sugar /

100 ALIGN! 27 Mar: 3.03 0.49 300 27 Mar: 3.07 0.52 500 27 Mar: 3.19 0.61 500 46 3.37 0.64 1500 90 5.01 0.88

These results show an increased production of glycerin and succinic acid when yeast and carbohydrate concentrations increase during fermentation.

Other variables that can be used to optimize the production of the desired products while maintaining ethanol production are the osmotic pressure maintained during fermentation, dissolved carbon dioxide concentration, pH, temperature, choice of microorganism used, fermentation method and formulation and preparation of fermentation medium. . Increased osmotic pressure derived from stillage recycling, increased dissolved fraction concentration and / or increased temperature increase glycerin and succinic acid production as well as increased dissolved carbon dioxide.

Yeast and most other microorganisms are able to regulate the internal pH very effectively in the pH range of the mash from about 3 to about 7, and thus influencing the fermentation process by pH variations is minimal. However, it has been determined that glycerin and succinic acid production can be improved if, during the first half of the fermentation stage, the pH is maintained at a substantially constant pH (substantial amounts of glycerin and succinic acid are formed) by adding a suitable alkali such as carbonate sodium.

The nature of the fermentation broth or fermentation mash also affects the production of glycerin and jan-tartaric acid due to the interaction effects occurring and the

in the starting material product itself; in particular the concentration of any liquefying enzyme, the ratio of fermentable sugars to non-sugars, the type of non-sugars present, and the nutritional requirements of the selected fermentation microorganism.

Proper selection of the parameters described above results in improved production of glycerin and succinic acid in the process of the invention. The following examples demonstrate the effect of these parameters on glycerin and succinic acid production.

----------------------------- _{Example 3}

The mash prepared from ground whole maize was subjected to jet boiling for 3 minutes at 152 ° C, liquefied to DE 20.6 and partially saccharified. The batches of this mash were then fermented and distilled using the operating parameters given in Table 3 below. ”In this tablecloth, this is a poor result.

Table 3

Procedural parameters AND Batch (B) C D YCC 1,2 3.1 9.0 26.5 DE 33.2 56.3 78.7 78.7 Recycle 0 38.3 44.1 71.4 Temperature 30 34 35 35 pH 4,5 5.5 6.0 5.0 Head atm. 0.0112 0.016 0.008 Yeast type loosely imobil. imobil. imobil Time 58 39 12 9 Extracts in g to ₌ 100 g reducing sugar: Ethanol 44.9 44.1 42.0 44.7 Glycerine 4.8 5.8 8.3 12.3 Succinic acid rová 0.6 0.7 1.1 1.4

- 32 In the above table, YCC refers to the yeast concentration in g / l, with 1 gram containing about 10 ¹⁰ cells. DE means dextrose equivalent after saccharification. Recycle means percentage of recycled stillage.

Temperature is the fermentation temperature in degrees Celsius. pH means the pH that is maintained in the first half of the fermentation process by the addition of carbon monoxide. Head symbol ”means hydrostatic pressure in MPa. The fermentation time is given in hours.

It is clear from the results for each batch that the yields of glycerin and succinic acid increase in each subsequent batch, which is accompanied by only a slight negative effect on the production of ethanol alone. ------- Example 4

The mash was prepared from clarified and pasteurized final molasses, and the individual batches of mash were then fermented and used to work together with the snowmeats which are jointly and genuinely. height - in the following table 4 ·

- 33 Table 4

Procedural parameters Batch E AND (B) C D YCC 1.0 3.0 18.2 32.0 20 May Reduk.cukr 184 184 192 200 200 Recycle 0 24.7 43.0 37.9 48.4 Temperature 30 34 34 35 35 Head atm. 0.006 0.013 0.015 0.008 Yeast type loosely loosely imobil. imobil. imobil · Fermentation batch. batch. batch. kontin. batch. Time 51 27 Mar: 10 6 12 PH 4,5 5.0 6.0 _ _ 1,5__ 5.0.

Yields in g per 100 g reduction.

sugar: Ethanol 48.3 47.8 43.9 46.4 45.1 Glycerine 3.7 4.3 8.4 5.1 10.9 Acid John- tarová 0.5 0.6 1.0 0.8 1,2

In the preceding table, the symbol Reducing sugar refers to the reducing sugar concentration in g / l and the Fermentation symbol determines whether the fermentation was carried out batchwise or continuously. Other Mani Symbols Used Here ._—

- -. ,. -. j.

the same meaning as in Table 3.

From the results shown in the above table, it is clear that operating conditions can be selected in which the maximum production of glycerin and succinic acid is not achieved, but which indeed has only a slight negative effect on the production of ethanol alone.

Example 5 ------------------------------------------------ -------------------------------------------------- In order to illustrate other embodiments of the process according to the invention, in which the optimal production of glycerine and succinic acid may not always be achieved, a wood hydrolyzate of yellow spruce was prepared. This hydrolyzate was clarified and then batch fermented. The pH was held constant--for ~ 25 hours, wherein the housing stillage něby- ^_ ~ ly recycled - ^ - Eermentaee-was-performed & -podmínek 2; which, together with the results achieved, are given in Table 5 below.

Table 5

Procedural parameters Batch C Λ (B) YCC 15.0 40.0 40.0 Reduk.cukr 54.3 54.3 74.1 Temperature 31 33 34 Head and dark. 0,002 0.008 Yeast type loosely imobil. imobil Fermentation batch. batch. batch. Time 68 43 41 pH 5.0 5.5 5, ° Yields in g / 100 g reduction sugar Ethanol 29.4 34.5 40.4 Glycerine 3.4 3.9 6.9 Succinic acid 0.5 0.8 1.1

- Ex 36 ___ Pus from the bu zu podl e__vynéle .se-fermentation tubs it RMU-t _r --připravený according to any of the preceding examples is then further processed to yield pure glycerol derived z_přínodních-zdrojů- / A here-m High-purity and / or succinic acid. After this further treatment, the resulting solid may be dried to obtain DDG and DDGS and / or fertilizer premixes having a free-flowing nature and are easier to handle than similar products obtained by prior art processes due to the fact that glycerol was separated.

Usually, the first further processing step is the distillation of the fermented mash to obtain ethanol. For this distillation, a stripping column can be used which is capable of treating a liquid stream containing a certain solid. The residue at the bottom of the column (or stillage) is then centrifuged (if desired) and the liquid fraction thus obtained is then treated in a fining step to remove the dispersed solid and recover (sparkly). liquid. The clarification is completed by (transverse) microfiltration using a microfiltration system and absorbing ceramic or mineral membranes. In microfiltration, particles with a size in the range of 0.1 to 10 microns are separated from the stillage depending on the membrane used.

The high performance of the microfiltration device can be achieved by computer-controlled backwashing of membranes and appropriate membrane selection. These new microfiltration membranes are known per se and are commercially available from known suppliers. Such a microfiltration device may be directly incorporated into the overall device in which the method of the invention is carried out.

The chemical clarification may be carried out by removing about 20 percent of the total amount of stillage and adjusting the pH of the withdrawn portion to 9.0 to 12.0 at boiling or near a pH close to boiling. The remainder of the stillage is adjusted to between 4.5 and 7.5 at a practicable temperature with sodium hydroxide, calcium hydroxide and / or sodium carbonate. The two portions are then mixed to form a precipitate of the corresponding salt, the separation of which is improved by adding polyelectrolyte prior to centrifugation. Depending on the feedstock used, microfiltration or chemical clarification is followed by a (partial) softening step in order to reduce the concentration of divalent calcium and magnesium cations. This prevents clogging and clogging of the longer-used ion-exclusive resin by the salt deposit of bivalent cations, which in turn significantly reduces the efficiency of the used resin.

introduced

Once the stillage has been clarified, it can be / into the evaporator

38 to remove as much water as possible and thus to achieve the highest concentration of dry matter. As a result of the previous clarification of stillage has. ‘In the concentration process, the overall heat transfer coefficient_ is more favorable than in the case where the stillage has not been cleared, since the fouling of the heat exchange surfaces with a solid proportion of stillage is limited to a minimum.

The clarified and thickened stillage is then fed to an ion-exclusive device such as commercially available from the Illinois Water Treatment Company of Rockford, Illinois and containing a suitable resin, such as IWT SM-51-Na resin or the like

--------------------- Lowex 50-WX8 resin available from Dow Chemi cal.

While the stillage passes through the ion exchanger, glycerin is retained while the other stillage components pass through the column. The efficiency of this isolation ranges from about 80% to about 98% and the purity of the isolated glycerin ranges from about 80% to about 90%. The apparatus used may be a single or multiple column system operating as a half-bed or as a simulated ₌ movable bed.

Recycling of the eluate can be used to maintain or increase the purity of the product and / or the efficiency of the isolation. As the desorbent, condensate from any evaporator used in the system can be used, the ratio being

The 39 desorbent to the stillage fed is in the range of about 1.6 to about 3.0. Such a column is then intimately balanced and does not need any regeneration.

The effluent from the glycerin isolation column, after concentration, may be introduced into a similar column to isolate succinic acid. The diluted succinic acid solution is then concentrated in an evaporator and purified by crystallization. The resulting by-product stream from the ion-exclusive stage, before or after isolation of succinic acid, is ideal for use as a backflow in fermentation. It is a clean stream that will increase the osmotic pressure level and reduce process water consumption.

The glycerin stream from the ion-exclusive apparatus can be further purified on a mixed-bed ion exchanger and then concentrated and purified to the desired degree of purity. Such thickening and purification can be accomplished, for example, by using an energy efficient vacuum evaporator with multiple steam effects, and a distillation and refining unit such as a unit commercially available from G. Mazzoni SpA, Italy, whereby the concentrated glycerin is then optionally removed. bleaches, filters and / or polishes.

Example 6

Plant stillage for the production of ethanol from wet milled maize - by means of G-Centrifugation and - obtained - sparse firing^-” subjected to microfiltration in a ceramic membrane microfiltration unit. The clear passing part was partially softened and then concentrated by evaporation to a dry matter content of 73%, while the passing part thus concentrated still retains the properties of Newton's liquid. This portion was then fed to an IWT Adsep system with a 7.62 cm diameter column packed to a height of 158 cm with IWT SM-51-Na resin with a dry matter content of about 60%. The concentrate was fed at a rate of 0.81 l / min.dm² at 20% pulses at 1.4421 / pulse. The glycerin-containing effluent was then introduced into an IWT mixed bed ion exchange unit to improve the purity of the glycerin. The effluent pH was then adjusted to 7.0 with sodium hydroxide, then the effluent was concentrated by evaporation using a Mazzoni to a glycerine content of 83.1% by weight and distilled and refined to obtain a high grade glycerin grade CP / USP.

The content of the process is shown in Table 6 by weight.

Table 6

Component V; γpálky Clarified and thickened stillage The effluent from Adsep Final product Total dry matter 7.37 5.01 1,21 tracks Protein 2.36 1.07 tracks Carbohydrates 1.19 0.38 0.03 Tujky 0.007 0.003 0.001 Ash 0.84 0.77 0.09 Lactic acid 1.42 1.32 0.05 tracks Kys. amber 0.09 0.08 0.006 Other 0.343 0,306 0,026 tracks Glycerine 1.01 0.96 0.94 ₀ , ₉₂₄ Water 92.63 8.91 15,687 0.007 Total 100.00 13.92 18.04 0,931 Glycerin /% / 1.01 6.90 5.19 99.25 Na / ppm / 10 700 740 K (ppm) 4500 70 Mg (ppm) 960 70 Ca (ppm) 240 4 Mn / ppm 90 2

- ¹ 42 y 2 e ^ ® ^ ÓÍ.cl čÁ3ti will pQpisu - popsón-natural-kladj -------PRL obtained by ethanol, glycerol, succinic acid and lactic acid. ......

Example 7

The mash prepared from milled yellow dent number two corn was boiled and liquefied to a dextrose equivalent (DE) of 21.3. The mash was then partially saccharified and subsequently fermented using co-immobilized yeast Saccharomyces cerevisiae with glucoamylase using the fermentation conditions, which, together with the results obtained, are shown in Table 7 below.

- 43 Table 7

Procedural Batch parameters AND (B) C YCC 107 118 15 Dec DE at the beginning of fermentation 82 84 21 Recycle 83 84 40 Temperature 38 39 34 pH 6.8 7.2 5,0-3,9 Head 0.11 0,112 atm. Time 7.4 7.9 49 Yields in g / 100 grams reduced. sugar ______ Etbanol 43.9 43.1 47.9 Glycerine 17.0 20.2 9.1 Acid amber 1,8 1.9 0.8 Lactic acid tracks tracks 11.9

- 44 ______________________________________________Symbol p_H. prior to Table 7, refers to a pH value that is maintained during the first two-thirds of the fermentation process by the addition of sodium carbonate

Batch A - and - mixtures of sodium hydroxide and sodium sulfite in batch B. The symbol of the head refers to the hydrostatic pressure in the fermenter expressed in MPa. The fermentation time is expressed in hours.

The process listed in Lot C differs from Lot A and Lot B. The Lot C process is based on the production of ethanol from wet ground corn. The fermentation is carried out continuously and the pH is allowed to vary from a starting value of 5.0 to a final value of 3.9 during the fermentation.

The results shown in Table 7 show that a significant improvement in glycerin production is achieved, but this has only a relatively small negative effect on the ethanol production. The production of glycerin and succinic acid can be improved even longer, but it already has a significant nega - = "tivir = effect ^ on" irethanolUT "production"

In the processes of Example 7, the fermented mash is then distilled to strip off ethanol. The resulting bottom from the bottom of the column is then clarified to obtain a clear liquid. Preferably, a microfiltration system with inorganic and / or organic membranes having a pore size in the range of about 0.1 to about 10 microns is used to remove the solid particles. For the first time, these inorganic membranes allow very good stillage clarity.

The hot stillage either immediately after distillation or after centrifugation and / or filtration to remove coarse particles can now be processed to obtain the desired products. The advantageously used computer-controlled backwashing of membranes allows high microfiltration throughput and eliminates the need for chemical cleaning of membranes that attack the membranes more. The stillage may be pre-treated chemically to form flocs which, under controlled conditions, form a dynamic membrane to improve the clarity of the stillage. For this purpose, known filter devices with the above-defined characteristics can be incorporated into the device according to the invention.

Said filtration provides a concentrate or retained fraction which is further processed into DDG or DDGS, animal feed, human food ingredient or fertilizer base to which a by-product stream from the chromatographic separation process described below can be added. In addition, the microfiltration provides a passing fraction, which can optionally be softened to remove divalent cations that would otherwise clog and clog the longer-ranked release resin or the downstream release resins.

The clarified stillage is concentrated in the next step to the highest possible dry matter content. As a result of the clarification, the overall heat transfer coefficients have more favorable values, since the evaporation of the water does not cause the formation of solids in the heat transfer surfaces. When the fermentation substrate is diabetes, cooling and / or addition of sulfuric acid results in the formation of potassium sulfate, which can be isolated by crystallization to yield another valuable by-product.

This is followed by chromatographic separation of the clarified and concentrated fraction of stillage. In a preferred embodiment of this chromatographic separation, the clarified and thickened stillage is introduced into an ion-exclusive device containing a suitable resin. Glycerin, which is an unionized compound, is unaffected by Lonnan potentials and is freely distributed in the aqueous pore structure of the resin grains, while the ionic compounds pass the resin grains and exit the ion exclusion device first. The ion-exclusion and ion-exchange resins may be of the potassium monovalent form, allowing the separation of ionic and non-ionic components as well as improved formation of potassium sulfate to the maximum extent possible. The achievable isolation efficiency of glycerin ranges from about 80% to about 98%, while the purity of the isolated glycerin ranges from about 80% to about 98%.

As a chromatographic separation device, a single-column or multi-column system may be used, which may be operated as a pulsed bed or as a simulated movable bed in continuous operation. Condensate from some of the evaporators in the system can be used as desorbent here, thereby minimizing process water consumption. The ratio of desorbent to isolated glycerin ranges from about 10 to about 25. Such a system is ionically balanced and normally does not need any regeneration.

The by-product stream containing succinic acid and lactic acid can be concentrated to the highest possible dry matter content, whereupon succinic acid and lactic acid can be separated in a further chromatographic step using either acid retardation or ion exclusion. The succinic acid stream is concentrated and the acid is isolated by crystallization. Similarly, lactic acid can be isolated by standard procedures. In most cases, ion exchange of product streams will improve the purity of said products. Depending on the resin, winter conditions and operating conditions used _____________, betaine and glycerine may be removed from the chromatographic separation step together. It is then necessary to use a subsequent chromatographic separation for the purpose of geno-betaine treatment. .——-—-—

In the stream from which the betaine can be isolated by standard procedures. A remarkable distribution is achieved by using IWT-AM-63 resin or a similar resin. 98 percent of glycerin and more than 92 percent of betaine were isolated.

The desorbent may be any of the condensates produced within the process. In an in-service test at 60 ° C, 5.7 kilograms of water per kilogram of betaine was used as desorbent α-13.6 kilograms of water per kilogram of glycerin, yielding 395 mg of betaine per minute per o_ __ _____ 2 __ _ - _________________________________ cm a166 mg per minute per cm.

The glycerine stream is concentrated in an evaporator to a dry matter content of approximately 85%. Concentrated crude glycerin can be neutralized before being introduced into the rectification section of the high performance distillation column. As a result of product withdrawal and direct steam injection, a low partial pressure is maintained in the wheel, which "minimizes" the degradation of glycerin. The glycerin leaves the condenser separator and is deodorized by steam and bleached with granulated activated carbon. The consumption of activated carbon is minimal due to the already relatively pure state of the bleached glycerin.

The product is then passed through polishing filters and a condenser to obtain ultra-pure glycerin. Evaporative, distillation and refining plants are known per se and are available, including design improvements over conventional glycerine production facilities from G. Mazzoni SpA (Italy).

It is also possible by the process of the invention to obtain glycerin, succinic acid, betaine, L-pyroglutamic acid, potassium sulphate and solid fertilizer from beet molasses, without specifically preparing these stillage to increase their glycerin and succinic acid contents. Such a process is illustrated in the following example.

Example 8

As illustrated in the attached Figure 2, the stillage from the plant for the production of ethanol from beet molasses is processed to ultra-pure glycerin and betaine hydrochloride in a continuous manner. During the fermentation, no precautions were taken for improved glycerin production. The bitter stillage was clarified in a transverse microfiltration unit with a membrane of alpha-modification alumina (0.2 micron). The passage obtained was enzymatically treated at 50 ° C to hydrolyze the proteinaceous material and then evaporated to a dry matter content of greater than 66% by weight.

By cooling and crystallization in a malaxer, potassium sulfate crystals are formed which are isolated by centrifugation, washing. ₌ .

And drying to obtain technically pure potassium sulfate, which is in this form more valuable product than if left in the remaining stillage (fertilizer). The liquid fraction from the centrifuge is then fed to a first chromatographic separation system in which the betaine plus glycerin mixture is separated from the remaining fraction. This ion-exclusive system uses a stronger acidic cation exchange resin in potassium form with a particle size of about 375 microns and a moisture retention capacity of about 52.5 form H +; IWT SM-51 /. The product stream contains a total of 36.3% solids with approximately 9% or more of glycerin plus ________________ betaine. As the desorbent is water used · The product stream is then concentrated to a total solids content of 75 #, then introduced into a second, substantially smaller chromate © graphic system that includes polystyrene strongly bézickou ⁶ an anion exchange resin in the sulfate form. Its mean particle size is approximately equal to 350 microns and its water retention capacity is 41 to 46%. Both of these resins meet all the requirements for substances used in feed and food applications (FDA Regulation Title 21, Subpart A, Seetion 173-25). This second chromatographic separation step yields a glycerine stream with a purity of 97.6% (after a mixed bed ion exchange) and a betaine stream with a purity of 88.2%. The glycerin stream is then processed to ultrapure glycerin using a G. Mazzoni SpA. The betaine stream is in turn processed into pure betaine and betaine hydrochloride. A total of 88.5% glycerin and 93.2% betaine were isolated.

The remaining stillage is then mixed with the product stream from the first chromatographic separation stage, the retained fraction from the microfiltration stage, and the product streams from the glycerine purification, whereupon the resulting mixture is concentrated and dried to solid manure with a feed additive or feed additive.

In the second chromatographic separation step, the other resin used also provides pure glycerin and pure betaine stream. This resin is a strongly acidic cation exchange resin in calcium form with a mean particle size of 350 microns and a moisture retention capacity (form H +) of 57.5 to 61.0%. Succinic acid and L-pyroglutamic acid are not isolated.

Table 8 below shows the concentration of the main components in weight percentages at each treatment stage.

- 52 Table 8

Total Suspended Glycerin Betaine dry matter fraction

Shapes 7,5 1,0 0.7 1.5 Passing fractions from microfiltration 6.5 0.7 1.5 Concentrate after concentration 60.0 6.3 13.5 After the first matographic separation 36.3 10.6 22.7 Concentrate after concentration 75.0 22.0 47.0 Glycerine stream after second chromatographic separation 38.2 37.3

after a second chromatographic separation

0.5

23.7

20.9

The foregoing specific examples are illustrative only and are not intended to limit the scope of the invention in any way.

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120 00 PRAGUE X Ha & em *

Claims (3)

PATENT CLAIMS JAlOiNlSVlA CH3Ar <s. \ Wsad σ / y o 1. Continuous processing of stillage 2.5! ΙΛ 5 0 produced by the fermentation and distillation of biological materials from the group consisting of maize, wheat and grain, sugar cane, beet sugar beet, grapes and other fruit., .. potatoes, cassava, sugar sorghum and others, b. .1 *. it prepares mash, iento from said biological materials. _The mash is fermented with yeast and then distilled to form ethanol and said stillage, characterized in that the process comprises the following steps: (a) clarification of stillage comprising cross-microfiltration using inorganic membranes from the group comprising ceramic and mineral membranes having a pore size ranging from 0.1 to 10 μιη, (b) subjecting the clarified stillage to a first chromatographic separation in which the clarified stillage is ion-selective a column for separating the glycerol and betaine in the form of a mixture from the other components of the clarified stillage, (c) subjecting the glycerol and betaine mixture to a second chromatographic separation in which the mixture is passed through a second ion selective column in which the glycerol is separated from betaine; purification of the glycerol and betaine thus separated. Process according to claim 1, characterized in that the steps of fennentation, distillation, clarification, chromatographic separation and purification are part of a continuous process. The method of claim 1 or 2, wherein the clarification step further comprises an initial centrifugal separation of the solids from the liquid components before subjecting the stillage to microfiltration. Method according to any one of the preceding claims, characterized in that the second chromatographic separation is carried out 1 n * ____________________ _____anion exchangeable _.ge 1 o. particle size approximately 350 microns and capacity moisture retention, ranging from 41% to 46%. . . The method according to any of the preceding claims. 10, characterized in that the second chromatographic separation step comprises draining said clarified stillage into a chromatographic separation system comprising a strong acidic cation exchange resin in calcium form with a mean particle size of approximately 350 microns and a moisture retention capacity ranging from 57.5 to 61.0% . > Process according to any one of the preceding claims, characterized in that the proportion of glycerol is purified by ion exchange, evaporation to a concentration of 80 to 85% glycerol, further distillation to almost pure glycerol and refining to ultra-pure glycerol. A method according to any one of the preceding claims, characterized in that the glycerol fraction and the betaine fraction originating from the second chromatographic separation step are each subjected to ion exchange, further concentration and purification by distillation and refining to glycerol and crystallization into betaine and betaine hydrochloride. .