DE102020001942A1 - Process for the efficient separation of solution and solids from hydrolyzate suspensions and its use - Google Patents

Abstract

Process for the efficient separation of solution and solids from hydrolyzate suspensions, in particular from brewing mashes, wort hydrolyzates from plant components and from filter cakes or press cakes from hydrolyzates from plant components, in the field of food, drug and luxury food production, from hydrolyzate suspensions in the processing of organic residues and their use as resources, characterized in that one feeds the suspension after enzymatic or acidic or alkaline hydrolysis in a continuous stream MS1 to a mass transfer system SAS, which consists of at least two stages, preferably four to ten stages, in or in where solids are fluidized and mixed in liquid, the transport of solids from stage to stage by gravity or with pumps and consequently in each stage a solids-rich and a solids-poor zone is formed, from the solids-rich suspension into the one direction, solid Low-substance solution flows in the other direction - a stream MW1 of a pure liquid, which is suitable for displacing the solution and for absorbing solutes, is fed into the system against the direction of flow of the solid; - a stream MW2 is discharged from the system as a solution which contains up to 99.99% of the solutes contained in the solution of the stream MS1; the stream MW2 is fed to a separating device 1 for the separation of the solid phase discharged from the system with the stream MW2 into a suspension stream MSR and a product stream ML; - the suspension stream MSR corresponding to a proportion of 0 to 90% of the stream MW2 is mixed with the suspension stream MS1 to adjust the solids concentration in the suspension stream MS2 before it enters the system; - discharges the remainder of the stream MW2 as product solution ML for further use or processing; - After flowing through the system, solids are withdrawn from the system in a suspension stream MS3, the solids of the S stream MS3 is essentially suspended in the liquid of stream MW1 and only contains a small amount of the solutes in the solution from MS1; feeds the suspension of higher concentration in a stream MS4 from the separating device 2 for further use, the stream MW1 being selected so that an efficient desired recovery rate of the solution of 50 to 99.9 %, preferably from 80 to 95%, is achieved in the product solution ML.

Description

The invention relates to a method for the efficient separation of solution and solid from hydrolyzate suspensions and its use.

Hydrolysis is an important process for the extraction of valuable substances from plant and animal biomass for the treatment and production of food, beverages, chemicals, fuels and renewable energy sources.

Mashing brewing malt is such a hydrolysis process. The enzymes in the malt break down (hydrolyze) proteins and starch under the respective conditions for the optimal temperature of the enzymes.

The brewing malt is first crushed (crushed) and then mashed with brewing water in a mashing vessel. The mashing process is traditionally a discontinuous process for which various variants for operation under the optimal operating conditions with regard to temperature graduation and reaction control (resting) are known, namely infusion and decoction processes. The polymeric malt components protein and starch are hydrolyzed by malt enzymes (proteases and amylases) and the hydrolysis products (peptides and amino acids, sugar) are dissolved in the brewing water. At the end of the mashing process, there is usually a temperature phase for thermal deactivation of the malt enzymes.

After the mashing process, the wort is extracted, i.e. the solution of the hydrolysis products (the first wort), in a solid-liquid separation process, which is known as lautering when brewing beer. This separation process is also classically carried out discontinuously and is usually a filtration.

Since after a single filtration in the filter cake (solid residue from the malt, spent grains) there is still wort in the gaps and the pores of the particles, the filter cake is washed in several steps with brewing water (so-called top-ups). The second wort is combined with the first wort, which results in a lower content of hydrolysis products, the original wort, in the total wort compared to the first wort. The original wort as a measure of the fermentable sugar content is decisive for the alcohol content of the beer through the subsequent fermentation with brewing yeast.

In many processes for the hydrolysis of raw materials that contain biopolymers, for the production of food and dietary supplements, beverages, extracts, essences, flavorings, the content of the hydrolysis products in the finished hydrolyzate or the wort cannot be easily adjusted (as in the brewing process by adjusting the ratio of malt grist to brewing water). For this reason, the hydrolysis suspensions are still pressed after the "wort" has been removed in order to increase the yield of usable liquid phase. Nevertheless, considerable amounts of wort (solution with hydrolysis products) still remain in the press cake.

In order to obtain this residual wort, which usually still represents around 40 to 70% of the press cake as intergrain fluid and pore fluid, complex, repeatedly repeated washes with water (or more generally: with solvents) are necessary, which requires a lot of solvent and time . As with the production of wort, the wort is diluted during brewing, so that it is often necessary to re-concentrate.

These disadvantages of the classic lautering or wort extraction processes can be avoided with a continuous process according to claim 1 of the invention.

In general, a continuous mode of operation already has great advantages over discontinuous process management: unproductive times for filling and emptying apparatus are avoided, the usual dilution effects due to transient processes do not take place, reaction and mass transfer devices as well as conveying devices (pumps, screw conveyors) can be designed for lower capacity and thus more cost-effectively.

In addition, the reaction or mass transfer process can be carried out with greater efficiency in continuous operation, comparable to that of batch operation. The prerequisite for this, however, is that apparatus systems are used in continuous operation that have a defined flow pattern and thus residence time behavior for the fluid phases involved. The present invention takes up this knowledge and applies the process features and phenomena based thereon to the separation of solution (wort) and solids (filter cake).

As early as the second half of the last century, continuous processes for the production of wort by lautering became known. This is how the script came from US 935,570 from 1963, in which a method for continuous lautering is described in which a continuous belt filter is used.

Also in the U.S. Patent 3,128,189 from 1964 uses the method for the extraction of Beer wort a continuous filtration process with a belt filter, which is divided into three zones for filtering or washing the filter cake.

The patent specification DE 1 254 566 from 1967 describes a method and a device for the continuous extraction of malt wort with a continuously operating rotary filter.

Another method for the continuous lautering of brew mashes, described in U.S. 3,436,226 from 1969, uses a continuously operated disc or plane filter with sectors for filtering and washing out the spent grain.

from 1969 is also a German publication, DE 1 292 102 , which describes a continuously operating lauter device for the production of wort. This device, too, is of the disk or plane filter type with a number of lauter tuns installed in radially arranged sectors.

While belt, rotary or disc filters are used to separate the wort from the spent grains (solids) in the methods described so far, reports DE 1 804 343 from 1970 by a device with preferably two extractors, in which the mash is separated and washed one after the other in the flow (continuously). These extractors consist of conical and rotatably mounted sieve bodies for the separation or extraction and washing of spent grains.

Another way of separating wort and solids is the in DE 23 50 847 described plant for lautering mash for beer brewing. A cascade of containers and hydrocyclones is used here.

With the DE 24 50 636 A method and device are also presented for separating and washing suspended solids from a liquid, in particular for separating brewing wort from grain residues, which uses two or more continuously operating clarifying centrifuges (decanters) for separation.

In DE 30 29 531 A1 describes a continuous process for the production of wort, in which both the mashing and the lautering should take place continuously. The lautering therefore takes place in lauter tuns arranged vertically one above the other, which instead of false bottoms consist of funnel-shaped baffles for dividing the wort into sedimentation spaces, from which the wort and, one after the other, the top-down pourings are drawn off of the spent grains arise.

the DE 10 2015 105 849 A1 with the designation "Device, system and method for treating a suspension, preferably containing plant components, in particular the separation of a liquid or a solid from it, in the field of food, drug and luxury food production and corresponding uses" finally describes a preferably continuous, multi-stage Filtration and extraction, which is also based on repeated separation by filtration and washing out.

The processes, methods, apparatus and systems shown are all based on the continuous, mostly repeated (multi-stage) separation of the wort from the solids with washing or leaching (extraction) of the solids (spent grains) with water (called secondary pourings when brewing beer). In spite of the continuous or also quasi-continuous mode of operation, they appear to be associated with a high outlay in terms of apparatus.

For an efficient extraction of solution (wort) from a suspension (solid / liquid mixture), an effective separation of the solution (L-phase, consisting of the solvent, often water, and the hydrolysis products dissolved in it) from the solid Phase (S-phase) is necessary in a separation process or separating apparatus, but also “washing out the S-phase (filter, press residue) with pure solvent to obtain the residual solution. This can be done in a continuous way in that the separation process and the washing process are not carried out several times in succession in one apparatus (i.e. discontinuously), but in several separation units in series, i.e. in a multi-stage cascade (see 1 ) one after the other. The suspension is conveyed through the cascade in one direction (from A to B), the solvent in the opposite direction, i.e. in countercurrent to the flow of the S phase (from B to A). This type of process control is known as countercurrent washing or countercurrent extraction, whereby in most applications of the principle a more or less complete separation of the S and L phases takes place in each stage.

In this way, an extensive depletion of the hydrolysis products from the solid phase can be achieved with simultaneous quantitative conversion of the hydrolysis products into the L phase with a reduced amount of additional solvent to be added. The efficiency of the recovery of the products is the better, the larger the flow of solvent supplied at A is selected, but with an increasingly larger flow, the concentration of the product in the solution flowing off at B becomes lower due to dilution. The dilution effect can be achieved through a high number of stages can be reduced, but this increases the expenditure on equipment and the operating costs.

The solution provided by the invention is based on the knowledge that such a process can also be carried out in a multi-stage system in which no separation is carried out, but in which the S-phase is transported through a force field. It is not necessary here that a targeted countercurrent of solid and liquid is also brought about within a stage. On the contrary, through suitable flow guidance in one stage or through an input of mechanical energy (e.g. through stirring), the suspension and L-phase are mixed in each stage, which promotes the mass transfer and thus leads to a better separation result.

If the system consists of only one stage, one can assume that the flow pattern in the system corresponds to that of a mixed stage, i.e. the system shows the residence time behavior of a mixing reactor or mixing apparatus: stirred tank characteristics. In this case, the concentrations of the hydrolysis products in the product stream ML and in the suspension stream MS4 would then be the same. An effective continuous separation of the hydrolysis products cannot be achieved in this way.

If an absolute counterflow of solid and liquid could be achieved in the system, the concentration of the dissolved solids in the product stream ML would correspond to that in the suspension MS1 fed in and that in the suspension stream MS4 discharged to that in the liquid stream MW1 fed in, i.e. the solvent. This would make the most efficient separation possible. Such a flow guidance would be the "ideal plug flow", also referred to as plug flow or plug flow characteristic. Such a characteristic can be approximated in a system that consists of a large number of mixing stages, whereby the "ideal plug-flow characteristic" is only achieved with an infinitely large number of stages (comparable to an infinite exchange time in the discontinuous process or with an infinite number of consecutive washing processes).

A practical implementation of the invention is possible if the mass transfer system SAS thus corresponds to an apparatus with plug flow characteristics. Such apparatus are known from other fields of application for continuous processes (e.g. continuous polymerization reactions, liquid-liquid extraction, gas-liquid mass transfer such as distillation or absorption, solid-liquid extraction). For use in the process according to the invention, a stirred tank cascade ( 1 ), Multi-stage stirred cell column ( 2 ), Multi-stage vortex cell column ( 3 ) and multi-stage fluidized bed column with sieve trays in question.

The mass transfer system SAS can be designed both as a vertical column, cascade with flow through from top to bottom, but also as a cascade with a horizontal arrangement of the stages.

The method is characterized according to claim 1, that the hydrolyzate suspension, which is obtained after enzymatic or acidic or alkaline hydrolysis of solids (mostly biomasses) in aqueous dispersion, in a continuous stream MS1 (see 4th ) feeds a mass transfer system SAS at one end A, which consists of at least two stages, preferably four to ten stages, in which solids are fluidized and mixed in liquid, the transport of solids, starting from A , takes place from stage to stage by gravity or with pumps and consequently a solids-rich and a solids-poor zone is formed in each stage, from the solids-rich suspension in one (generally vertical) direction, solids-poor solution in that other direction flows.

At its other end B, the system is supplied with a stream MW1 of a pure liquid, which is suitable for displacing the solution and for taking up solutes, counter to the direction of flow of the solid.

At one end A, a stream MW2 is discharged from the system as a solution, which stream contains up to 99.99% of the solutes contained in the solution of stream MS1. The current MW2 is a separator 1 to separate the solid phase discharged from the system with the stream MW2 into a suspension stream MSR and a product stream ML. To adjust the solids concentration before entering the system, the suspension stream MSR can be mixed with the suspension stream MS1 to form the suspension MS2 in a proportion of 0 to 90% of the stream MW2 and thus fed back into the system at A. However, it can also be removed from the system in order to recover the discharged solids (lees), in particular if the dilution of the suspension MS1 is not necessary. The remainder of the stream MW2 is discharged as product solution ML for further use or work-up. The stream MW1 is chosen so that an efficient, desired recovery rate of the solution of 50 to 99.9%, preferably from 80 to 95%, is achieved in the product solution ML.

After flowing through the system, solids are withdrawn from the system in a suspension stream MS3, and preferably one continuously operating separating device 2 for solid-liquid separation, the solids of stream MS3 being essentially suspended in liquid of stream MW1 and only containing a small amount of the solutes of the solution from MS1. The suspension MS3 is in the separation device 2 separated into a suspension of higher concentration and into a liquid stream MF, this stream MF, together with stream MW1, is fed back into the system at B.

The suspension of higher concentration is discharged from the separating device in a stream MS4 for further use. It can be used as animal feed, for the production of molded parts, for composting, for generating biogas or for generating energy.

The procedure is based on the 5 and 6th explained in more detail using examples:

5 shows, using a scheme for the mass transfer system SAS with five stages, the result of a calculation of the recovery of wort from the press cake of a hydrolysis of wheat gluten. The press cake has a water content of 40% and a dry matter content (TS) of 60%, of which 22% consists of insoluble solids (fibers, starch). The rest of the 60% TS consists of non-volatile hydrolysis products, salts and fat dissolved in the water.

The mass transfer system SAS can be configured as a vertical stirred cell cascade with five stirred cells (example with 4 cells: 2 ) can be understood. the 5 . Stage is one end A, to which the suspension flow MS1 (420 kg / h) is fed with a screw pump. This suspension stream is diluted with suspension in a mixing container M before entering the 5th stage, which is then diluted with a separator 1 was separated from the product stream MW2 from the stream of the product solution ML. As a result of this recirculation, the solids content of the suspension MS1 is diluted from 22% to around 15%, with which the stage 5 is now being charged.

A stream MW1 with 210 kg / h of water is fed to the first stage (at the other end B of the SAS system), together with the stream MF of the liquid from the stage 1 that are in the separator 2 from the level 1 removed suspension MS3 was separated in order to obtain the suspension MS4 with a higher concentration ( 35 % FTS).

In each stage, the suspension stream is mixed with the liquid, which flows from the first stage from stage to stage up to the fifth stage in countercurrent to the solid, while the solid flows from the fifth to the first stage. As a result, the solutes are absorbed by the countercurrent liquid and enriched against the flow of solids, while the solute concentration decreases from the fifth to the first stage.

In this five-stage cascade, with a “wash water” flow of 210 kg / h (MW1 / MS1 = 50%), a wort regenerate of 366 kg / h with a concentration of around 41% of dissolved matter in the L phase is achieved . The dissolved concentration in the feed suspension is 49% (based on the L-phase), so that a regenerate is obtained, the concentration of which is almost 90% of that of the hydrolyzate (the product wort). The amount of the wort ingredients is recovered with a yield of 95%, the loss of hydrolyzate ingredients is only 5%.

A second example is the effective extraction of malt wort from malt mash. It presents the result of tests on a small scale with a multi-stage vortex cell column of the “inclined-bottom column” type with four stages (e.g. according to 3 ). This is done with a calculation of a SAS with four levels according to 6th compared.

When extracting malt wort, the extract content (= sugar, original wort) in the wort is used as a measure of the separation yield. The column is continuously charged directly with the mash from the mash vessel after the malt starch has been saccharified with glucoamylase, without separating the spent grains (solids) beforehand. In this experiment, the mash feed (suspension MS1) was 4 kg / h with an extract content of 11.5% (glucose) and a solids concentration in the suspension of approx. 5%. The experiment was without the separators 1 and 2 carried out.

A high volume flow of “washing water” (MW1) of 20 kg / h was set in comparison to the suspension flow. After a short time, a steady state has been established, characterized by the discharge stream MS3 kept constant at 5 kg / h by means of a pump. This inevitably results in a product flow MW2 of 19 kg / h in which a glucose concentration of 22.3 g / l was measured. The calculation gives a value of 2.3% extract. A concentration of 0.45 g / l glucose was measured in the suspension MS3 discharged from the foot of the column from the first stage, and 0.24 g / l (0.03%) was calculated. This shows that the test column is well described by a 4-stage cascade. The calculated extract yield is 99%, the loss in yield determined from the measurement data is 0.5%. The suspension concentration in MS3 is 4%.

This example shows that the choice of operating conditions for the recovery of the wort was not optimal. Although the multistage is clearly evident through a high extract yield, the extract content in the wort flow MW2 is much lower than in the mash.

This fact could be improved, as a simulation with the calculation shows: If the "wash water flow" MW1 is reduced to 5.5 kg / h, the result is an extract concentration in the wort of 8%, but the extract yield now drops to 82% 1.6% extract in the discharge.
However, this would be significantly improved if a column with a higher number of stages were used. The model calculation with 10 stages under the same operating conditions as that with four stages shows that the wort concentration is increased to 9.2%, with the extract yield now also being much higher at 95% with 0.5% extract in the discharge. This makes it clear what a major role the number of stages plays in the efficiency of the process.

The second example also shows that the basic idea of the invention does not depend on whether the suspension is concentrated by a separator or filter after the “washing”, nor on the separation of any solids discharged with the product stream MW2 at the top of the column which does not have to be returned to use in principle. Both separators are, however, particularly useful for the application of the process for separating the wort from the spent grains during the brewing process, in order to adjust the quality of the wort product without loss of extract or to extract the spent grains with less residual moisture in order to use it as animal feed or to process it for extraction of valuable materials (e.g. in accordance with a process for the material recycling of industrial and agricultural biomass and of biogenic residues after DE 10 2016 014 103 B4 ).

This field of application in particular shows the enormous potential that could be tapped with the new process in order to convert the discontinuous lautering process with lauter tun or mash filter, which is very efficient today, into a continuous process that is used for the large quantities of mash in large breweries would be more economical and sustainable.

But also for the many smaller hydrolysis processes in the food industry, the switch from discontinuous to continuous separation with the new process could be of advantage, because it can significantly increase the product yield and thus the savings in raw materials and energy can be improved.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 935570 [0012]
• US 3128189 [0013]
• DE 1254566 [0014]
• US 3436226 [0015]
• DE 1292102 [0016]
• DE 1804343 [0017]
• DE 2350847 [0018]
• DE 2450636 [0019]
• DE 3029531 A1 [0020]
• DE 102015105849 A1 [0021]
• DE 102016014103 B4 [0046]

Claims (7)

Process for the efficient separation of solution and solids from hydrolyzate suspensions, in particular from brewing mashes, wort hydrolyzates from plant components and from filter cakes or press cakes from hydrolyzates from plant components, in the field of food, drug and luxury food production, from hydrolyzate suspensions in the processing of organic residues and their use as resources, characterized by the fact that one - The suspension after enzymatic or acidic or alkaline hydrolysis in a continuous stream MS1 is fed to a mass transfer system SAS which consists of at least two stages, preferably four to ten stages, in which solid matter is fluidized and mixed in liquid, with solids are transported from stage to stage by gravity or with pumps and consequently a solids-rich and a solids-poor zone is formed in each stage, from the solids-rich suspension in one direction, solids-poor solution in the other Direction flows. a stream MW1 of a pure liquid, which is suitable for displacing the solution and for absorbing solutes, feeds the system against the direction of flow of the solid; a stream MW2 discharges from the system as a solution which contains up to 99.99% of the solutes contained in the solution of stream MS1; - Feeds the stream MW2 to a separating device 1 for the separation of the solid phase discharged from the system with the stream MW2 into a suspension stream MSR and a product stream ML; - The suspension flow MSR corresponding to a proportion of 0 to 90% of the flow MW2 is mixed with the suspension flow MS1 to adjust the solids concentration in the suspension flow MS2 before it enters the system; - removes the remainder of the stream MW2 as product solution ML for further use or work-up; After flowing through the system, solids are withdrawn from the system in a suspension stream MS3, the solids from stream MS3 being essentially suspended in liquid from stream MW1 and only containing a small amount of the solutes in the solution from MS1; - The suspension MS3 is fed to a separating device 2 and is separated in this into a suspension of higher concentration and into a liquid flow MF and this (together with the flow MW1) is fed back into the system; - The suspension of higher concentration in a stream MS4 discharges from the separating device 2 for further use, the stream MW1 being selected so that an efficient desired recovery rate of the solution of 50 to 99.9%, preferably from 80 to 95%, in the Product solution ML is achieved. Process for the efficient separation of solution and solids from hydrolyzate suspensions according to Claim 1 , whereby - the mass transfer system SAS is at least one apparatus with plug flow characteristics and corresponds to one of the following types: a) stirred tank cascade b) multi-stage stirred cell column c) multi-stage fluidized cell column d) multi-stage fluidized bed sieve tray column - the separation device 2 is selected from the following types: e) Gravitational separator f) Decanter g) Belt filter h) Rotary filter i) Disc filter j) Flat filter k) Screw press I) Belt filter press m) Filter press Use of the procedure according to the Claims 1 and 2 for the efficient extraction of wort from mash for beer production, characterized in that a mass transfer system with at least 2 stages, but preferably 3 to 20 stages, particularly preferably 5 to 10 stages, is used, in a more than 4-stage version During the mashing process, 99% of the substances that are important for the brewing process and are brought into solution by enzymatic hydrolysis are obtained in the wort. Use of the procedure according to the Claims 1 and 2 for the efficient extraction of seasonings from the hydrolyzate of wheat gluten, characterized in that a mass transfer system with at least 2 stages, but preferably 3 to 20 stages, particularly preferably 5 to 10 stages, is used, in a more than 4-stage version 99% of the substances brought into solution by enzymatic hydrolysis in the wort are recovered in the process. Use of the procedure according to the Claims 1 and 2 for the efficient extraction of seasoning from the press cake, which arises as a residue during the separation of wort from the hydrolysis of wheat gluten by diluting the press cake with the solution MW2 to a flowable consistency and thus the system, consisting of more than 3 stages, preferably 5 up to 10 stages, whereby in a 5-stage execution of the process 90% of the substances brought into solution by enzymatic hydrolysis are obtained as wort in a concentration of 90% of the amount of substance originally present in the press cake. Use of the procedure according to the Claims 1 and 2 for the efficient extraction of solution from press cake, which arises as a residue during the extraction or pressing of vegetable seeds and herbs, by diluting the press cake with the solution MW2 to a flowable consistency and thus the system, consisting of more than 3 stages, preferably 5 to 10 stages, is supplied, whereby in a 5-stage execution of the process 90% of the substances brought into solution are obtained in solution in a concentration of 90% of the amount of substance originally present in the press cake. Use of the procedure according to the Claims 1 and 2 for the efficient recovery of valuable substances in the processing of hydrolyzates from organic residues (spent grains, fermentation residues, bran, apple, grape and / or wine pomace, citrus pomace and similar vegetable, animal and microbial residue biomasses) as well as residues from biological wastewater and waste treatment, characterized in that a mass transfer system SAS with at least 2 stages, but preferably 3 to 20 stages, particularly preferably 5 to 10 stages, is used.

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