SK3772002A3 - Sugar beet membrane filtration process - Google Patents

Abstract

The present invention relates to a process for producing sugar from beets, comprising the steps of: (e) slicing sugar beets into cossettes and obtaining a sucrose-containing feed juice therefrom by diffusion, wherein the feed juice also comprises ash and invert sugars; (f) filtering the sucrose-containing feed juice through a first ultrafiltration membrane that has a first molecular weight cutoff of at least about 2,000 daltons and a pore size no greater than about 0.1 microns, thereby producing a first ultrafiltration permeate and a first ultrafiltration retentate; (g) filtering the first ultrafiltration permeate through a second ultrafiltration membrane that has a second molecular weight cutoff that is lower than the first molecular weight cutoff and is between about 500-5,000 daltons; thereby producing a second ultrafiltration permeate and a second ultrafiltration retentate; and (h) filtering the second ultrafiltration permeate through a nanofiltration membrane; thereby producing a nanofiltration permeate and a nanofiltration retentate, wherein the nanofiltration retentate has a higher concentration of sucrose on a dry solids basis than the feed juice in step (c), and wherein the nanofiltration permeate comprises at least about 30% of the ash and at least about 30% by weight of the invert sugars present in the second ultrafiltration permeate.

Description

Technical field

The present invention relates to a process for the production of sucrose from sugar beet.

BACKGROUND OF THE INVENTION

A common method of producing sugar from sugar beet involves cleaning the beet, slicing it into chips, extracting the juice from the cut by diffusion, purifying the juice by clarifying with lime and carbonation, concentrating the juice by multiple evaporation, multi-stage cooking of concentrated juice in pans, separating, scrubbing and drying sugar .

In a conventional method, the extraction of the juice is carried out by allowing the sugar to diffuse through the natural walls of the beet cells. Cell walls allow sugars and other low molecular weight compounds to cross, but prevent the passage of high molecular weight compounds. This selective diffusion process has two advantages. Retention of high molecular weight compounds helps to produce very pure juice. It also reduces the filtration difficulties that are caused by polysaccharides and proteins that include high molecular weight compounds.

Beet juice purification is based on lime treatment in a conventional method. Lime serves many purposes in the lime purification process. It neutralizes the acidity of the juice and precipitates the calcium salts of several organic and inorganic acids. The precipitate absorbs other impurities. The lime precipitate forms a porous mass which facilitates subsequent filtration of the juice.

The conventional diffusion method for extracting beet juice has its advantages. It has a long retention time that promotes microbial growth, resulting in loss of sugar and formation of unwanted compounds. It is difficult to raise the temperature of cut pieces sufficiently fast to prevent the growth of microorganisms. The slurry remaining after diffusion is generally compressed and the squeezed juice is returned to the diffuser. A substantial portion of the high molecular weight compounds that are retained by the cell walls in the diffusion process is released during compression and mixed with the diffusion juice. This partially negates the advantages of the selective diffusion method.

A conventional lime blackening method uses a large amount of lime, which is up to 2.5% of the total weight of the beet being processed. Sugar factories therefore operate lime kilns and transport the limestone over long distances. Waste from lime blackening and carbonation, consisting of used lime and separated impurities, is disposed of as waste. The production of lime and the disposal of waste from the milling are costly operations.

The disposal of ripening waste is becoming increasingly difficult and expensive in many communities.

Conventional complete filtration is not capable of separating sucrose from macromolecular impurities in sugar beet. Several methods of using microfiltration and ultrafiltration to purify lime-reduced juice are also described, but these methods generally involve inserting microfiltration or ultrafiltration membranes at one or more sites of conventional beet processing methods.

There is a long-term need to find better ways of obtaining sugar from beet that would prevent or at least minimize one or more of the problems existing in the previously used methods.

SUMMARY OF THE INVENTION

The present invention relates to a process for producing sugar from sugar beet. In one embodiment, the method comprises the steps of: a) either 1) macerating the beet or pieces thereof, or 2) cutting the beet into shreds, b) separating the juice from the macerated beet or shreds, and c) separating the juice by membrane filtration to prepare ultrafiltration residue and ultrafiltration filtrate .

In another embodiment, the method comprises the steps of: a) macerating the beet or pieces thereof, b) mechanically separating the juice from the macerated beet, and c) membrane filtration the separated juice to prepare an ultrafiltration residue and an ultrafiltration filtrate. This embodiment of the present invention uses mechanical means, such as vacuum filtration, to separate the juice from macerated beet, which differs from the simple diffusion method used in the prior art processing technology to obtain juice from the chips.

In some particularly preferred embodiments of the method, wherein the beet is cut into pieces and then macerated and the maceration is carried out in a disk mill, it is also preferred that vacuum extraction of the juice be performed on a moving porous filter belt with a countercurrent flow of macerated beet and water. most preferably at a temperature of at least 80 ° C. The pH of the vacuum extracted juice is preferably adjusted to about 7 by the addition of sodium hydroxide.

In one particularly preferred embodiment of the method, the juice is contacted with an agent selected from the group consisting of sulfur dioxide, sulfate salts, sulfite salts, hydrosulfite salts and mixtures thereof in an amount sufficient to adjust the pH of the extracted juice to a value not exceeding 8.

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Membrane filtration may suitably be performed with an ultrafiltration membrane, a nanofiltration membrane, or other types of membranes described herein. In one preferred embodiment, the membrane filtration is a cross-flow ultrafiltration, and is performed at at least 80 ° C and the pH of the ultrafiltration filtrate is at least 7.

One preferred method alternative is to subject the filter residue from the membrane filtration to diafiltration to obtain residual sugar in the filter residue, thereby forming a diafiltration filtration filtrate (also referred to herein as a diafiltrate). This diafiltrate is preferably combined with a membrane filtration filtrate for further processing.

Another preferred variant of the process is the concentration of the filtrate from the reverse osmosis membrane filtration to produce a concentrated solution. This concentrated solution was evaporated and sucrose crystallized therefrom.

In the process according to the invention, the juice or filtrate is preferably not contacted with lime and carbon dioxide.

One specifically preferred embodiment of the method comprises the steps of: a) cutting sugar beet into pieces, b) macerating beet pieces, c) mechanically extracting juice from macerated beet, d) spreading the extracted juice, e) adjusting the pH of the extracted juice to at least 7, f) g) subjecting the filter residue to diafiltration to produce a sugar-enriched diafiltration filtrate as compared to a filter residue, h) combining the diafiltration filtrate and the membrane filtration filtrate to produce a combined juice, i) concentrating the combined juice by reverse osmosis to produce a concentrated solution i) evaporating the concentrated solution and crystallizing sucrose therefrom.

This embodiment of the present invention has many advantages over the conventional method of triggering diffusion, lime blackening and carbon dioxide saturation. For example, the method has a lower retention time which reduces the extent of microbiological destruction of sucrose. The fineness of the macerated beet reduces the percentage of sucrose retained in the slurry below 0.5% compared to 0.75% in the conventional method. Higher extraction due to maceration and lower inversion due to reduced retention time increase the overall sugar yield by 1 to 2% by weight, based on the beet being processed.

This method of purification produces from sugar beet juice which is less colored than traditional carbon dioxide diffusion and saturation. The lesser coloring of the juice allows less washing of the final crystalline product. Membrane filtration removes the macromolecules in the beet juice so that a syrup of lower viscosity is produced. Low viscosity syrups crystallize faster and are more readily displaced from the surface of sucrose crystals. A low-colored, low-viscosity syrup reduces the recycle during the crystallization process, resulting in better sugar recovery.

The method excludes a lime kiln, limestone extraction furnace and all associated equipment, processes, products, by-products and waste products. Sodium hydroxide on

Even neutralizing juice costs about half of it as lime it replaces. Sodium hydroxide is easier to handle, cleaner and less abrasive for the plant than lime.

The present invention also greatly reduces waste that causes environmental pollution. In a conventional manner, a filter cake is produced which includes lime blackening products and impurities removed from the juice. This cake is placed in ponds or landfills. The proposed method completely eliminates the need to dispose of such materials, the inert sugars end up in molasses, which is a marketable by-product and not in waste. The present invention also allows the elimination of carbon dioxide saturation, which is a major source of air pollution in sugar refineries.

In another embodiment of the present invention, the sucrose-containing feed juice obtained from the sugar beet is filtered through a first ultrafiltration membrane that produces a cut at a first molecular weight. This ultrafiltration step produces a first filtration ultrafiltration filtrate and a first ultrafiltration residue. The first ultrafiltration filtrate is filtered through a second ultrafiltration membrane that produces a cut at a second molecular weight that is lower than the cut at a first molecular weight level. This second ultrafiltration step forms a second ultrafiltration filtrate and a second ultrafiltration residue. The second ultrafiltration filtrate is nanofiltrated through a nanofiltration membrane to form a nanofiltration filtrate and a nanofiltration residue. The nanofiltration residue has a higher sucrose concentration, based on dry matter, than the initial juice introduced into the first ultrafiltration step and can be used in the firing and crystallization operations to produce white sugar crystals.

In one particular embodiment of the invention, the sucrose-containing inlet juice is produced by macerating sugar beet or pieces thereof to form a macerated material that includes slurry and liquid and then separating the liquid contained in the macerated slurry material from, for example, one or more operations from the centrifuging group. , conventional filtration or screening. In one particular embodiment, the beet is macerated such that it first passes through a hammer mill, and optionally then passes through a grinding machine, where the beet is turned into a mixture of slurry and a liquid containing sucrose. After separation of the liquid from the slurry, no more than about 5 wt. sucrose, preferably no more than about 3%.

After separating the pulp slurry from the liquid and prior to the first ultrafiltration, the method may optionally include an additional step or steps to remove the rest of the beet and slurry fibers from the separated liquid (juice). This can be done by slaking or by filtration. Preferably, the decalcification or filtration removes at least 90 wt. % of all fibers and sludge having a maximum dimension of about 150 µm or greater, preferably at least 90 wt. All fibers and sludge having a maximum dimension of 50 µm or greater.

In a further embodiment of the invention, instead of macerating the cut into shreds, the sucrose-containing inlet juice is obtained by diffusion.

It is also possible to introduce air into the inlet juice before the first ultrafiltration to oxidize the color-forming materials. This oxidation, which enhances the coloring of the juice, causes the color-forming materials to polymerize, which facilitates removal by subsequent ultrafiltration. (Where the present patent refers to the polymerization of coloring materials, it is believed that this includes physical agglomeration as well as chemical polymerization.) Another possibility is to introduce hydrogen peroxide, ozone, or both into the feed juice prior to the first ultrafiltration. These materials also facilitate oxidation.

The pH of the feed juice is preferably adjusted to between 6 and 8 prior to ultrafiltration, for example by addition of a base. This can help minimize invert formation.

Preferably, the first ultrafiltration membrane produces a cut at a molecular weight of at least 2000 daltons and a pore size of not more than about 0.1 µm. Preferably, it is cut at a molecular weight of about 4000 to 200,000 daltons. The ultrafiltration filtrate of the first filtration preferably has a coloring of about 3000 to 10,000 icu. (All staining values given here are determined on an ICUMSA scale.)

The process of the present invention can be performed for a variety of process conditions. An example of these conditions is that the inlet juice may have a temperature of 60 to 93 ° C (140 to 200 ° F) during the first ultrafiltration, preferably 71 to 85 ° C (160 to 185 ° F).

The second ultrafiltration membrane performs a cut at a molecular weight of 500 to 5000 daltons, preferably at a molecular weight of 1000 to 4000 daltons. In one particular embodiment of the method, the second ultrafiltration is performed in two stages, the first stage using an ultrafiltration membrane making a cut at molecular weights at 3500 to 4000 daltons and the second stage using an ultrafiltration membrane making a cut at a molecular weight less than 3500 daltons. The second ultrafiltration filtrate preferably has a coloration which is not more intense than 4000 icu, even more preferably not more than 2500 icu.

In order to minimize the loss of sucrose in the filter residue from the first and second ultrafiltration steps, it is preferred to include diafiltration steps in the process. "Diafiltration" is used herein to mean ultrafiltration, which uses water added to the inlet to assist the passage of sucrose through the membrane.

In one such embodiment of the method, the first ultrafiltration residue is diafiltered through at least the first diafiltration / ultrafiltration membrane. This creates a first diafiltration filtrate and a first diafiltration residue. The first diafiltration filtrate is then combined with the first ultrafiltration filtrate and filtered through a second ultrafiltration membrane,

Similarly, the filter residue from the second ultrafiltration can be diafiltered through at least a second diafiltration / ultrafiltration membrane. This second diafiltration step forms a second diafiltration filtrate and a second diafiltration residue. The second diafiltration filtrate is then combined with the second ultrafiltration filtrate and subsequently filtered through a nanofiltration membrane.

The filter residues from the first and second ultrafiltration (or diafiltration) and the nanofiltration filtrate may be combined to produce molasses. This combined stream may require to be concentrated by evaporation of water.

In addition to purifying juice by nanofiltration, ion exchange or electrodialysis purification steps may be included in the process. The three cleaning methods can be used in any order. In one particularly preferred embodiment of the method, the nanofiltration residue is purified by electrodialysis to form the electrodialysed juice and the electrodialysed residue, and then the electrodialysed juice is purified by ion exchange to form the purified juice. None of the filtrates is preferably contacted with lime or carbon dioxide.

Nanofiltration removes ash (including monovalent and divalent cations), invert, organic acids, nitrogenous material and other low molecular weight organic or charged compounds. The nanofiltration and optional electrodialysis or ion exchange preferably remove at least about 65 wt. Ca, Mg, K, Na and the associated inorganic and organic anions present in the second ultrafiltration filtrate. Ion exchange replaces residual divalent cations such as calcium and magnesium with monovalent cations such as potassium and sodium. The nanofiltration residue preferably has a lower concentration of divalent cations on a dry matter basis than the filtrate from the second ultrafiltration.

The nanofiltration filtrate will contain a large percentage of impurities that were present in the inlet juice. In many cases, for example, the nanofiltration filtrate will comprise at least 30 wt. solids ash, at least 30% invert and at least about 25% betaine present in the inlet juice.

The clarified juice (i.e. after nanofiltration and electrodialysis or ion exchange) preferably has an ash concentration of not more than 2.5% by weight. on a dry weight basis, preferably not more than 2%, most preferably not more than 1.0%.

After membrane filtration steps (and electrodialysis or ion exchange steps), water can be evaporated from the purified juice to produce a concentrated syrup (e.g., with 75% solids). The white sugar can then be crystallized from concentrated syrup. Due to the high degree of impurity removal, the present invention can achieve two crystallizations of white sugar from concentrated syrup versus one that is typical of the prior art processes.

After one or more crystallizations of white sugar from the concentrated syrup, the mother liquor remains. This mother liquor can be recycled to one of the ultrafiltrations, or the recycle stream can be further purified to reduce the raffinose content.

The method may optionally include propagating one or more process streams. In particular, the at least one aqueous stream selected from the group consisting of the inlet juice, the ultrafiltration filtrate of the first ultrafiltration, the ultrafiltration filtrate of the second ultrafiltration, the nanofiltration residue of the nanofiltration and the evaporator feed can be contacted with an agent selected from the group consisting of sulfur dioxide, sulphite salts, hydrosulphite salts, metabisulphite salts, dithionites and mixtures thereof, in an amount sufficient to ensure an equivalent sulfur dioxide concentration in the stream of at least 100 mg / kg (ppm)

One particularly preferred embodiment of the invention is a method for producing sugar from beet, comprising the steps of:

(a) maceration of sugar beet or pieces thereof to form a slurry containing an aqueous liquid containing sucrose;

b) separating the sucrose-containing liquid from the slurry (or as an alternative to steps a) and b), cutting the sugar beet into cuttings and extracting the sucrose-containing inlet juice by diffusion),

(c) filtering the sucrose-containing liquid through a first ultrafiltration membrane that cuts at a molecular weight of 4,000 to 200,000 daltons to form a first ultrafiltration filtrate having a coloration of no more than 10,000 icu and a first ultrafiltration residue;

d) filtering the first ultrafiltration filtrate through a second ultrafiltration membrane that cuts at a molecular weight of 2000 to 4000 daltons to form a second ultrafiltration filtrate having a coloration of not more than 4000 icu and a second ultrafiltration residue;

e) filtering the second ultrafiltration filtrate through the nanofiltration membrane to produce a nanofiltration filtrate and a nanofiltration residue from the nanofiltration, wherein the nanofiltration residue has a higher dry matter-based sucrose concentration than the sucrose-containing liquid in step (b),

f) purifying the nanofiltration residue from nanofiltration by at least one of the group consisting of ion exchange and electrodialysis, thereby producing an evaporator spray,

(g) evaporating the water from the evaporator feed to form a concentrated syrup; and

h) crystallizing white sugar from concentrated syrup Alternatively, this embodiment of the method may further comprise the steps of:

(i) crystallizing the mother liquor from the first crystallization to produce white sugar;

(j) treatment of the mother liquor from the second crystallization by chromatographic separation or raffinose removal enzyme; and

k) recycling the treated mother liquor back to the feed stream into the nanofiltration or evaporator feed.

Another aspect of the present invention is a method of purifying sucrose-containing juice obtained from sugar beet. This method includes steps.

(a) introducing enough air into the juice to cause the color particles to polymerize; and

b) removing at least a portion of the colored particles from the juice by membrane filtration through a single ultrafiltration membrane or nanofiltration membrane.

Various aspects of the present invention have a number of advantages over prior art sugar beet processing methods. For example, the process of the present invention eliminates the need for a lime kiln, a limestone mine and all associated equipment, processes, products, by-products and waste products. The present invention also leads to a drastic reduction of waste products that cause environmental pollution. The conventional method produces a filter cake that includes lime blackening products and impurities removed from the juice. This cake is tied to ponds or landfills. The proposed method completely excludes the requirement of disposal of such materials. The present invention makes it possible to avoid the method of carbonation saturation, which is a major source of air pollution in sugar beet processing plants.

The present invention provides a cost-effective method of reducing ash content in beet juice or syrup, preferably to 2% or less (on a dry weight basis), more preferably to

1.5% or less, most preferably 1% or less. This reduction in ash content is important as it allows a second precipitation of sucrose crystals from the syrup. In the prior art beet processing methods, an ash content of 3.5% practically made it impossible to have more than one sucrose crystal precipitation operation.

In addition, the present invention eliminates, first of all, the need to remove sugar from the molasses stream. Effective membrane filtration steps prevent large amounts of sugar from entering the molasses stream.

The present invention further provides an economical and reliable method of removing coloring materials from beet juice. It can also reduce the generation of undesirable crystalline forms due to the presence of a considerable amount of raffinose.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a flow diagram of a method showing the method of the present invention for obtaining sucrose from sugar beet, the method comprising beet maceration.

Figure 2 is a flow diagram of a mass balance method for another embodiment of the invention.

Figures 3 and 4 are flow diagrams of a method showing an embodiment of the present invention in which sugar beet is macerated.

Figures 5 and 6 are flow diagrams of a method showing an embodiment of the present invention in which sugar beet is cut into chips.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides an improved method of obtaining sucrose from sugar beet. One embodiment of the invention is shown in FIG. First

Beet coming from the field is stored in the storage area 10. Usually fresh beets are used in the process, but frozen beets can also be used. The beets from the storage area 10 sail to a conventional washing machine 12 in which dirt is removed from the surface of the beets. The washed beets exiting the washing device 12 pass through the conveyor

14 where water is removed. The streams of wash water 18 and float water 16 collected from this apparatus are discharged to the waste water treatment ponds 20.

The washed beets 21 are conveyed by a conveying device 22 to a cutting device 24, such as a hammer mill or a cutter, in which the beets are cut into pieces, for example, pieces having an average thickness of 25 mm (1 inch). The stream of beet pieces from the chopper (or alternatively the entire beet 21) is fed to the maceration device 28. The maceration device 28 may comprise, for example, one or more hammer mills (preferably fixed blades) which use a set of rotary blades mounted on a horizontal shaft through the sieve. The other maceration device may include one or more disk mills that use disks as the primary disk mill device. Preferably, the discs have grooves therein to facilitate maceration and the discs may be in a horizontal or vertical position. A disc mill is currently preferred over hammer mills, although both mills may be used in succession (eg as a hammer mill followed by a disc mill). Extracted juice 28 or a stream of water 34 is added to the macerator 28 to facilitate the discharge of the macerated beet or to control the temperature of the machine.

The stream of macerated beet 30 is fed to a vacuum extraction apparatus 32 for juice extraction. The extraction apparatus 32 may comprise a horizontal, porous moving belt which is vacuum-operated from below. The macerated beet is fed as a uniform layer at one end (inlet end 33) of the web. At the opposite outlet end 35 of the belt, a stream of pure water is added. Thus, the inlet of the macerated beet and the inlet of water to this extraction apparatus 32 are countercurrent to each other. The juice stream 36 is reintroduced above the belt, preferably at several points. This anti-protein filtration method produces a stream of low-sugar slurry 68 and a stream of high-sugar extracted juice 38. The countercurrent vacuum filtration method is preferably carried out at an elevated temperature of about 80 ° C to control microbial growth and improve juice extraction.

A separating centrifuge or a series of centrifuges can also be used to separate the extracted juice 38 from the macerated beet material, slurry 68. The separating centrifuge may consist of either a vertical or horizontal rotary perforated basket in which the macerated beet stream 30 is fed into the basket and the solid phase , the macerated beet material, the slurry 68, and the liquid phase, the extracted juice 38, are separated from each other on the sieve by centrifugal force. The wash water 66 or the countercurrent stream 36 of the extracted juice is sprayed onto the macerated beet material, slurry 68, during centrifugation to minimize the sugar content of the slurry 68.

The slurry 68 leaving the extraction apparatus 32 has a very low sucrose content but a high water content. Compress in a screw press 70 to extract and dilute the squeezed juice 72, which contains about 1% dissolved solids and about 99% water. The dissolved solids consist of about 50% sucrose and 50% other than sugars. This dilute squeezed juice 72 is heated to a temperature of about 80 ° C in the heater 74 and then returned to the extraction apparatus as a juice stream 36. The pressed slurry 76 is used as animal feed, but may or may not be dried.

The extracted juice 38 is sent to the tank 41 and may optionally be propagated by adding sulfur dioxide or sulfite or hydrosulfite salts to the stream 40, for example gaseous sulfur dioxide or aqueous ammonium bisulfite at a concentration of about 65%. The residual sulfur dioxide level in the juice is preferably at least 100 ppm. The propagation may take place during cutting, maceration, juice extraction or at other points in the method as an alternative to or in addition to a particular propagation step according to this embodiment. This spreading will prevent the colouration which would otherwise occur during the operation after membrane filtration and evaporation. Other antioxidants may also be used.

The juice is then neutralized by adding an aqueous sodium hydroxide solution 42, preferably to a pH of at least 7, in the neutralization tank 43. This pH adjustment helps to prevent the inversion of the sugars that occurs at elevated temperature. Other, e.g. liquid potassium hydroxide or granulated sodium carbonate.

The juice extracted from the macerated beet by countercurrent filtration has about 0.2% suspended solids, about 14% dissolved solids and about 84% water. The dissolved solids are about 85% sucrose and 15% other than sucrose. The temperature of the extract is preferably about 80 ° C and its pH is at least 7.

The treated juice can then be passed through a heater 44 to raise its temperature to about 80 ° C.

The heated juice is then processed by membrane filtration 46, preferably by cross-flow ultrafiltration, to separate high molecular weight compounds from the sucrose solution. The ultrafiltration produces an ultrafiltration filtrate 48 (also referred to as a filtrate or clarified juice) that comprises about 12% dissolved solids and about 88% water. The dissolved solids comprise about 90% sucrose and 10% non-sugars. The ultrafiltration filtrate 48 preferably has a temperature of about 80 ° C and has a pH of at least 7.

The ultrafiltration filtrate has an equivalent purity of sucrose as a dilute juice produced by a conventional sugar process, which is about 90%, but there are important differences between non-sugars in both products. The ultrafiltered juice may contain a higher level of invert sugar or a lower level of macromolecular compounds than conventional thin juice.

Invert sugars in ultrafiltered juice primarily end up in molasses without drastically reducing sucrose recovery. This is an advantage over the conventional lime blackening process that sends the reaction products of lime and inverted sugars to the waste disposal system. Lower levels of the macromolecular compounds lead to a juice with a lower viscosity, which has better cooking parameters.

Ultrafiltration produces juice with less color. Extracted juice 38 typically has a color value greater than 100,000 on an ICUMSA scale. The ultrafiltration filtrate 48 typically has a coloring value on the same scale below 2000. It is equivalent to or better than the coloring value of the thin juice prepared in a conventional manner. A lower coloring in combination with a lower viscosity leads to an easier method of cooking sugar. The result is higher sugar extraction, more efficient sugar cooking and lower sugar loss to molasses.

A variety of membrane arrangements can be used in the present invention, including, for example, spiral, hollow fiber and tubular membranes. Membranes suitable for this separation process should have two unique properties. They should have high water and sucrose permeability, but low throughput for coloring agents and other macromolecular compounds. Dense ultrafiltration membranes cut the molecular weights between 1000 and 10,000 and thin nanofiltration membranes with about 10% NaCl rejection are well suited for this application. Membranes that have a negative surface tension have priority because most of the compounds to be rejected are negatively charged.

The ultrafiltration residue 50 of the ultrafiltration process contains mostly suspended and dissolved impurities. It also contains a significant amount of sucrose. To obtain at least a portion of this sucrose, the ultrafiltration residue 50 is diafiltered through a membrane system 52 with the addition of water 54. This diafiltration extracts most of the sugar remaining in the ultrafiltration residue. The diafiltration filtrate 56 contains about 3% dissolved solids and about 97% water. Soluble solids in the diafiltrate include about 88% sucrose and 12% non-sugars. The diafiltrate temperature is preferably about 80 ° C and its pH is greater than 7. Diafiltration residue 58 from the diafiltration process comprises about 5% suspended solids, 3% dissolved solids, and about 87% water. Concentrated by evaporation and used as animal feed, either mixed or not mixed with pressed paste

The ultrafiltration filtrate 48 and the diafiltrate 56 are combined to form a composite product stream 60. The composite product stream 60 (also called purified juice) contains about 11% dissolved solids and about 89% water. Dissolved solids include about 90% sucrose and 10% non-sugars.

The reverse osmosis membrane system 62 can be used to pre-concentrate the purified juice stream 60. It is another transverse membrane flow process to pre-concentrate dilute sucrose solutions that is less energy intensive and more economical than conventional process steps. The reverse osmosis system product 64 contains about 20% dissolved solids and about 80% water. Dissolved solids include about 90% sucrose and 10% non-sugars.

The reverse osmosis filtrate 66 is high quality water. Part 34 of this water is used in the upstream vacuum filtration process 32 and the remainder in other applications on the production unit, such as inlet water 54 to the diafiltering process 52.

The temperature of the previously concentrated solution of sucrose 64 is then raised in the heater 80 and subsequently the residual water in the evaporators 82 is removed. Sucrose crystallizes as in conventional processes.

Part of the apparatus used in this method of FIG. I is of the conventional type and is well known to those skilled in the art. These include beet washing equipment, slurry presses and evaporators. The beet cutting apparatus 24 and the maceration apparatus 28 are commercially available from suppliers such as H. Putsch GmbH & Company (Hagen, Germany), Maguin Company (Charmes, France), Dakota Machine Inc. (West Fargo, North Dakota, USA) and The Fitzpatrick Company (Elmhurst, Illinois, USA). A suitable vacuum apparatus with a juice extraction belt is available from EIMCO Company (Salt Lake City, Utah, USA) and Dorr-Oliver (Milford, Connecticut, USA). The centrifugal extraction apparatus is available from the Western States Machine Company (Hamilton, Ohio, USA) and Silver-Weibull (Hasslehom, Sweden). Suitable membrane filtration systems are available from suppliers such as CeraMem Corp.. (Waltham, Massachusetts, USA); Koch Membrane Systems, Inc. (Wilmington, Massachusetts, USA), and Osmonics, Inc. (Minneton, Minnesota, USA).

The following Table 1 shows suitable parameters of some process streams in FIG. 1, namely RDS (% by weight of refractive dry matter), purity (sucrose as% of total dry matter), pH and temperature.

Table 1

C. current RDS purity pH temperature ° C (° F) 38 12 85 6 38 (100) 45 12 85 8 71 (161) 48 11 90 8 71 (161) 50 15 75 WITH 71 (161) 58 8 20 WITH 71 (161) 64 20 90 WITH 71 (161) 66 3 88 WITH 71 (161) 72 I 50 6 38 (100)

Many variants are possible in the methods. Suitable variants include reverse osmosis prior to ultrafiltration, propagation after. ultrafiltration and sterilization of macerated beet by chemical or physical means. Another alternative is to separately treat the squeezed juice 72 instead of returning it to a countercurrent vacuum filtration process. It would also be possible to include treatment with a certain amount of lime or carbonation, but it is currently preferred that the process is carried out without the use of lime or carbonation.

A chromatographic separation could be used for further purification in this process. Chromatographic separation requires juice pre-treatment and juice softening. Since the juice of the present process has undergone membrane filtration and no lime has been added, it would be well suited for chromatographic separation.

Further use of membrane separation in the proposed method would allow the separation of sucrose from other beet juice components such as invert sugars and oligosaccharides.

If excellent quality beet is used, the chemicals used for pH adjustment and propagation can be reduced or eliminated. It is also possible to perform different unit operations with a few other method parameters, such as those set forth in the above-described embodiment or in the following examples.

It has been shown that by leaching macerated beet, 99.8% sugars can be obtained in six stages, using fresh water each. It has also been shown that ultrafiltration of juice is capable of yielding 99.8% sugar in six stages of diafiltration, but this extraction stage may be too ambitious for the industrial process as it involves excessive use of a diluent which must then be removed to recover sugar.

The weight balance of the process of the present invention was prepared based on the input of 1000 beet units with 78% water, 17% ROS, and 89% sucrose purity and with an estimated sugar recovery of about 99.5% in both extraction and diafiltration operations.

Figure 2 shows a flow diagram of this embodiment of the mass balance method. The numbers in bold are based on experimental data and other available information. All other figures are determined using constitutive and conservative relationships. EJ stands for extracted juice, LFP stands for ultrafiltration permeate, UFR stands for ultrafiltration retentate, DFP stands for diafiltration permeate, DFR stands for diafiltration retentate, MP mixed permeate) and NSDS means non-sugar dissolved solids. In FIG. 2, the beets are macerated with juice from the second stage of the extractor. The macerated beet is fed to the first stage of the extractor and the juice from this stage is fed to the ultrafiltration system. The slurry from the first stage moves through several stages of the extractor until almost all the sugar (99.5%) is extracted. Fresh water is fed in the last stage of the extractor. The extracted juice is processed by ultrafiltration to obtain 90% juice as ultrafiltrate. The ultrafiltration residue is diafiltered with a volume of fresh water that is five times its volume. By combined ultrafiltration and diafiltration, about 99.5% of the sugar contained in the feed is recovered.

Several improvements can be made to the method of Figure 2. The wet slurry can be pressed to reduce the moisture content to about 80%, and the pressed water can be used to replace some of the fresh water used in the extraction. The diafiltration filtrate from a later stage could also be used to replace some of the fresh water in the extraction process. These treatments will reduce the load on subsequent unit operations such as drying or transporting the slurry and reverse osmosis or evaporating the juice, but these measures reduce the efficiency of the extraction process and require more steps.

While the process of the present invention can be carried out in batch mode, it is particularly suitable for continuous operation.

Another embodiment of the invention is shown in FIG. 3. Beets coming from the field are stored in the storage area 110. In this method, fresh beets are generally used, but frozen beets can also be used. Beets from the storage area are floated by a conventional beet washing machine in which debris is removed from the beet surface.

The washed beets are conveyed to the maceration apparatus by a conveyor. The maceration apparatus may include, for example, one or more hammer mills 112 and one or more shredders 11 14. Suitable hammer mills 112 may use a set of rocking blades mounted on a vertical shaft that push the beet material through the exit screen. Another suitable type of hammer mill 112 uses a rigid blade. Another suitable maceration apparatus includes one or more disk mills that use disks as the primary disintegrator. The discs preferably have grooves therein to facilitate maceration. The discs may be horizontally or vertically adjustable. It is also possible to use both disc mills and hammer mills connected in series (for example, that the hammer mill is followed by a disc disintegration mill) or it is possible to have only one type of mills, i. hammer mill.

The partially macerated beet emerging from the hammer mill 112 may pass through a crusher 114 in which the beet material is further macerated. The macerated material leaving the crusher includes slurry (i.e., beet fiber material) and an aqueous liquid containing sucrose and other substances. Juice side streams 116 and 118 may be withdrawn from the outlet of the hammer mill 112 and crusher 114 and recycled to the inlet of these apparatuses. This increases the flow of liquid through the hammer mill 112 and the crusher 114 and helps to drive the solid part of the beet. The macerated material leaving the crusher 114 passes through a separator 120 to separate the liquid from the fibrous slurry. The separator 120 may suitably be a centrifuge, filter, or screen (e.g., rotary or vibrating screen or Dorr-Oliver DSM screen), or a combination of two or more such apparatuses. In the embodiment shown in FIG. 3 includes a centrifuge separator 120 that produces a slurry stream 122 and a juice stream 124. The slurry passes through a series of first sieves 126 and second sieves 128 with a countercurrent flow of aqueous liquid to help remove sucrose residues from the slurry. These sieves 126 and 128 may be rotary, vibratory, or DSM screens. The countercurrent flow is achieved by introducing a water stream 130 into the centrifuge 134 at the other end of the series of sieves 126 and 128. The slurry stream 132 exiting the end second screen 128 then passes to the centrifuge 134 where the low water slurry material 136 separates and the juice 138 obtained. the latter being passed countercurrently to the slurry through a series of second sieves 128 and first sieves 126. This centrifuge 134 debugs the slurry. The liquid 119 may be drawn from one of the sieves, usually from the first sieve 126, and passed into the juice stream in front of the centrifuge 120. Optionally, an anti-foaming agent of the fiber stream may be added to the juice to reduce foaming.

With the low water slurry 136, a portion of its residual water and sucrose is removed in the press 140. The water stream 142 from the press 140 is recycled to one of the sieves 128. The residual fiber 144 remaining after pressing can be used as animal feed.

Optionally, an air stream 146 may be injected into the juice stream 124 exiting the centrifuge 120. This will oxidize coloring materials in the juice, e.g. this will lead to an increase in color from 8000 to 16,000), which aids in the formation of co-polymerized colored bodies and thus facilitates the centrifugation of colored bodies at the next ultrafiltration. It is also possible to inject a stream 148 of hydrogen peroxide solution in addition to or instead of inlet of air. Hydrogen peroxide also aids the oxidation and polymerization of the coloring materials. Alternatively, ozone could be injected instead of hydrogen peroxide. The temperature of the juice at this point in the process is preferably raised by the heater 149, preferably to 60 to 93 ° C (140 to 200 ° F), even more preferably to 71 to 85 ° C (160 to 185 ° F)

The heated juice may be prefiltered prior to the first ultrafiltration to further reduce the already low fiber content. Pre-filtration can be accomplished, for example, by rotating the vibrating screen 150. The filter or screen 150 preferably has a mesh size of 30 to 100 μηπ and removes most of the fiber and sludge remaining in the juice by weight.

The heated and reconstituted juice 152 may optionally have its pH adjusted by the addition of a stream 154 that includes, for example, an aqueous solution of sodium hydroxide, calcium hydroxide or magnesium carbonate. This pH adjustment helps to avoid inversion of sugars that can occur at elevated temperature. Other chemicals such as liquid potassium hydroxide or granulated sodium or potassium carbonate may also be used to adjust the pH. The pH of the juice after this step is preferably in the range of 6.0 to 8.0, more preferably in the range of 6.5 to 7.5.

The pH adjustment juice, referred to herein as the juice 156 entering for ultrafiltration, is contacted with the first ultrafiltration membrane 158. The first ultrafiltration membrane 158 is preferably tubular or spiral and preferably cuts to at least 2000 daltons and has a pore size of no more than 0.1 μηι, more preferably cuts to molecular weights in the range of 4000 to 500,000 daltons, most preferably in the range of 10,000 to 200,000.

The ultrafiltration step produces a first ultrafiltration filtrate 160 and a first ultrafiltration residue 162. In this embodiment of the method, the first ultrafiltration residue 162 is then passed to the first ultrafiltration / diafiltration membrane 164 with the addition of water 166. This ultrafiltration / diafiltration membrane 164 may have a suitable pore size This first diafiltration 164 forms a first diafiltration filtrate 168 and a first diafiltration residue 170 (also called molasses 1 stream). Diafiltration minimizes the amount of sucrose lost in molasses (ie the dry solids basis (dsb) concentration is lower in the first diafiltration residue 170 than in the inlet _62), and it should be understood that there may be several stages of ultrafiltration 158 or diafiltration 164 .

The first ultafiltrate 160 will generally have a coloring of 3000 to 10,000 icu. The first ultrafiltration filtrate 160 and the first diafiltration filtrate 168 are combined to form a feed 172 for the second ultrafiltration membrane 174.

Prior to the second ultrafiltration, a sulfur stream 176 may be injected into the juice 172. This stream 176 may include, for example, sulfur dioxide or sulfite, hydrosulfite, metabisulfite or dithionite salts, such as aqueous ammonium sulfite or sodium hydrosulfite (e.g. at a concentration of 35-65%). Preferably, the residual sulfur dioxide level in the juice after sulfurization is at least 100 mg / kg (ppm). The propagation may be carried out at one or more points in the process, for example at the time of slicing or beet maceration, in the juice after it has been separated from the slurry, in the inlets for the first and second filtration or nanofiltration or in the evaporator feed. Most preferably, the spread is carried out in a spray on the second ultrafiltration. This propagation will prevent intensification of staining, which may otherwise occur during the membrane filtration and evaporation operation. Other antioxidants as well as anti-foaming agents may be used.

The second ultrafiltration membrane 174 preferably has a cut at a molecular weight of 500 to 5000, more preferably 2000 to 4000. The second ultrafiltration produces a second ultrafiltration filtrate 178 and a second ultrafiltration residue 180. The second ultrafiltration residue 180 is then mixed with the second raw material 234, the mother liquor. is recycled from the second crystallization of white sugar and passes through a second ultrafiltration / diafiltration membrane 182 with added water 184. The membrane used for the second diafiltration may have a pore size, ie. to a molecular weight that is lower in pore size than that of the second ultrafiltration membrane 174. This eliminates raffinose and prefers a membrane with a pore size in the range of 500 to 1000 daltons. This step creates a second diafiltration filtrate 188, which is mixed with the second ultrafiltration filtrate 178 and fed to the nanofilter 190, and a second diafiltration residue 186 (also referred to as the second molasses stream). In the second ultrafiltration 174 there may be more than one membrane filtration step or a second diafiltration 182. The second ultrafiltrate 178 from the second ultrafiltration will preferably have a color in the range of 1500 to 3500, in some cases less.

Optionally, the second diafiltration filtrate 188 or the first diafiltration filtrate 168 can be recycled to the diafiltration water stream.

Alternatively or in addition to ultrafiltration or diafiltration, the filter residue may be purified by chromatographic separation in a simulated moving bed separator system. This is shown in FIG. 4. This chromatographic separator 236 is preferably a multi-stage unit with three to twenty stages, more preferably ten stages. It preferably has three product slices, one of which is predominantly sucrose stream 237, the other is predominantly raffinose and ash, and the third is predominantly organic material, including organic acids. The two non-sucrose streams can be mixed to obtain a mixed stream referred to as the second molasses stream 186. The resin used in the separator is preferably a strong acidic cationic resin. The sucrose stream 237 is mixed with the feed into the evaporator. Alternatively, it could be added to the electrodialysis spray 192 or to the ion exchange 194 depending on the degree of debris removal.

The second ultrafiltration filtrate 178 is then purified by nanofiltration and optionally ion exchange or electrodialysis in any order. In the embodiment shown in FIG. 3, ultrafiltered juice 178 is first applied to nanofiltration 190, followed by electrodialysis 192 and softening 194 by ion exchange. Although the order of these three operations may vary, it is generally preferred to perform electrodialysis after nanofiltration.

The nanofiltration membrane coating typically comprises about 84% sucrose, 3 to 6% ash and about 0.5 to -4.0% inverse sugar (all on a dry weight basis). The nanofiltration membrane 190 divides the feed onto the nanofiltration filtrate 196 (also called the third molasses stream) and the nanofiltration residue 191, which will contain most of the sucrose from the beet. The nanofiltration filtrate preferably comprises at least 30 to 60 wt. % ash (especially Na, K, and Cl), at least 30 to 50 wt. % of inverted sugar (glucose and fructose), and at least 25 to 50 wt. betaine present in the nanofiltration feed 178. Nanofiltration achieves some reduction in color when switching from feed to nanofiltration to retentate. A typical nanofiltration filtrate will include 20% sucrose, 25% ash, 20% invert sugar, 8% betaine, and 25% other organic matter (based on dry weight). The nanofiltration residue 191 preferably comprises at least 89 to 91 wt. (based on dry basis) sucrose and will have a concentration of 15-28 Brix. Although nanofiltration can effectively remove potassium, it does not remove much of the citric acid, oxalic acid and malic acid present.

The nanofiltration residue 191 is then further purified by electrodialysis 192, which removes additional ash and various organic acids and other impurities, including some, which cause unwanted discoloration. Electrodialysis ensures good removal of oxalic acid and malic acid, with the total ash removal generally being over 40%. The electrodialysis impurity stream 198 is combined with the streams 170, 186, and 196 to form a molasses product stream 200.

Although electrodialysis can achieve good potassium removal, it generally does not remove the high percentage of magnesium that is present. Therefore, the purified electrodialysis juice 193, which typically contains 92 to 94% sucrose based on dry basis, is then preferably softened on an ion exchange unit 194 containing at least one ion exchange resin. A strong cation exchange resin based on a gel or macroporous matrix, with crosslinking in the range of 4 to 10%, is preferred. For example, resins such as Amberlite IR120 or Purolite C 100 from Rohm & Haas. They are used in sodium or potassium form. The primary purpose of this step is to remove divalent cations such as Ca and Mg and replace them with monovalent cations such as K and Na. This ion exchange step preferably removes at least 95 wt. Ca and Mg present.

The purified ion exchange juice 202, which preferably comprises more than 92% sucrose (dry solids), is then passed to one or more of the evaporators 204 to form a concentrated syrup 206, e.g. containing 75% dry matter by removing a significant amount of water. Optionally, sulfur stream 205 can be injected into evaporator 200. The syrup preferably has a pH of 6.5 to 7.5 and a temperature of 71 to 82 ° C (160 to 180 ° F) during evaporation.

The concentrated syrup 206 is fed to a first crystallizer 208 in which water is boiled off and a first group 210 of precipitated white sugar crystals is formed. The crystals 210 are centrifuged on a centrifuge 212, washed with water to remove residual liquid and the residual product is white sugar 214 (sucrose concentration 99.95%). The mother liquor 216 remaining after the first crystallization and centrifugation (typically containing 84-88% solids based sucrose) is fed to a second crystallizer 218 in which a second group 220 of white sugar crystals is formed. The crystals are also centrifuged in a centrifuge 222 to form white sugar 224. In the prior art beet processing method, the crystals formed during the second crystallization were dissolved and recycled because they were not pure enough to be sold as white sugar. The present invention is capable of achieving two groups of high purity white sugar due to better cleaning properties. In a particularly preferred embodiment, the crystallized sucrose (214 and 224) will comprise less than 0.015% by weight. ash, more preferably less than 0.01% ash and less than 35 icu. The mother liquor 234 remaining after the second crystallization (also referred to as greens or jets, and typically containing about 80% solids based sucrose) can be recycled, for example, to a second ultrafiltration / diafiltration 182. Alternatively, the crude recycle stream can be passed through a purification unit to the raffinose was removed. This purification can be accomplished by chromatographic separation of raffinose (see Fig. 4) (also leading to dilution of the raw material to 60 Brix), or alternatively by enzymatic digestion of raffinose 228 (see Fig. 3). Preferably, if this purification 228 is included in the process, the raffinose concentration in the raw material is reduced to a level not greater than about 1.0% on a dry matter basis. The enzyme used for the hydrolysis of raffinose is σ.-galactosidase (melibiasis), which cleaves raffinose into sucrose and galactose. This can be carried out batchwise in a stirred tank reactor at 50 ° C.

The process of the present invention may comprise multiple phases of ultrafiltration, nanofiltration, diafiltration, ion exchange or electrodialysis. For example, the first ultrafiltration shown in FIG. 3 could take place in two or more stages of ultrafiltration instead of being performed through a single membrane. It will be apparent to those skilled in the art that many other variations of the particular embodiment shown in the figure are equally possible. It should also be understood that the process can be performed for a variety of temperatures and other process conditions.

Another embodiment of the invention is shown in FIG. 5 and FIG. 6. Beets that have been removed from the field are stored in the storage area 110. In these embodiments of the method, fresh beets are generally used, but frozen beets can also be used. Beets from the storage area are floated to a conventional beet washing machine in which the dirt is removed from the beet surface. The washed beets can be cut into shreds, for example having a thickness of 0.6 cm, in the cutting apparatus 112.

The cut sliced beets are entrained by the conveying apparatus to the diffuser 1 14. Extraction of the juice is carried out by allowing the sugar to diffuse through the natural walls of the beet cells. Cell walls allow sugars and other low molecular weight substances to cross, but prevent the transientity of high molecular weight compounds. This selective diffusion process has two advantages. Retention of high molecular weight compounds helps to produce high purity juice. It also reduces the filtration difficulties caused by polysaccharides and proteins that include high molecular weight substances. The solid material 122 that remains after diffusion is passed to the press apparatus 126, which yields additional juice which can be recycled to the diffuser 114. The solids remaining after compression have a high fiber content and can be used as cattle feed. .

The remaining processes as shown in FIG. 5 and 6 are the same as those described in connection with FIG. 3 and 4.

A variety of membrane arrangements can be used in the present invention, including, for example, spiral, hollow fiber, and tubular membranes. These membranes can be made from a variety of materials including polymers, ceramics, carbon and sintered stainless steel. Membranes having a negative surface charge are particularly advantageous since most substances to be rejected are negatively charged.

Part of the apparatus used in the present method is conventional and well known to those of ordinary skill in the art, such as a beige and evaporator washing machine. The beet maceration apparatus is commercially available from suppliers such as Bepex Reitz (Santa Rosa, California, USA), Andriz Sprout Bauer (Philadelphia, Pennsylvania, USA) and The Fitzpatrick Company (Elmhurst, Illinois, USA). Beet diffusion apparatus is commercially available from suppliers such as BMA (Braunschweig, Germany) and Silver Engineering (Colorado Springs, Colorado, USA). The centrifugal extraction apparatus is available from Dorr Oliver (Milford, Connecticut, USA), the Western States Machine Company (Hamilton, Ohio, USA) and Silver-Weibull (Hasslehom, Sweden). Suitable membrane filtration systems are available from suppliers such as Koch Membrane Systems, Inc. (Wilmington, Massachusetts, USA), Osmonics, lnc. (Minneton, Minnesota, USA), PCI (UK), and SCT (France). Suitable ion exchange equipment and resins are available from Prosep (Roscoe, Illinois, USA), 1WT (Rockford, Illinois, USA), Purolite (Philadelphia, Pennsylvania, USA) and Dow Chemical (Midland, Michigan, USA). Suitable electrodialysis equipment is available from Eurodia (Paris, France) and Ameridia (Somerset, New Jersey, USA). A suitable chromatographic separation device is available from Prosep (Roscoe, Illinois, USA) and Applexion (Paris, France). Suitable raffinose digestive enzymes are available from Novo (Denmark) or Hokkaido Sugar Co (Japan).

It would also be possible to include treatment with a certain amount of lime or carbonation in the process, but it is currently preferred to carry out the process without contacting the feed juice or filtrates with the lime or carbon dioxide to effect carbonation. Lime or carbon dioxide can be added as bases

Example 1

Juicing of juice

The macerated beet slurry was mixed with water and pressed in fabric bags to form a squeezed juice. This sample was treated with sodium hydroxide, heated and used for a number of ultrafiltration experiments. Two different spiral ultrafiltration membranes were used in the experiment, type NTR7410 from Hydranautics and type HFK 131 from Koch. Experiments gave satisfactory flow rates, higher than in comparative experiments with conventional diffuse beet juice

Table 2: Extrusion filtration of extruded juice - experiment parameters and flows

Experiment no. pretreatment Type membrane Experiment conditions Experiment results temperature 7 ° C (° F) pressure kPa (pSLG) yield (%) Tok Imh 1 NaOH - heat spiral 66 (150) 483 (69) 86 30 2 NaOH - heat spiral 66 (150) 483 (69) 86 25

There was a substantial decrease in refractometric dry solids (RDS) and a very significant increase in the purity of sucrose after passing through the membranes. Both membranes did not leak more than 99% of the staining value. The increase in sucrose purity and color separation during these experiments was much higher than in comparable experiments with conventional beet juice diffusion.

Table 3: Extruded juice ultrafiltration - separation parameters

attempt no. chop down -žok (%) RDS (%) sucrose (% RDS) coloration spraying zvy- shock filtrate spraying zvy- shock filtrate spraying zvy- shock filtrate 1 86 8.9 10,0 7.7 85.8 78.4 91.1 67 256 158 78 5 925 2 86 8.9 10,0 7.8 85.8 78.4 90.6 67 256 158 78 5 1138

Example 2

A beet maceration experiment was performed using a Bauer atmospheric disk refining apparatus. This machine has two 30 cm (12) discs, adjustable gap discs, one stationary disc and another 45 kW (60 hp) drive. About 20 kg of beets were used in the experiment. The beets were chopped into 1.9 cm (3/4) pieces to make them suitable for the screw feeder.

All cuts were passed through the machine in one pass. Water was used to push the material through the machine, which led to dilution of the juice. A portion of the macerated product was pressurized to 20 psi in a membrane press for 15 minutes. Another part of the product was allowed to drain in a wire screen cabinet.

Table 4

material concentration Juice from membrane press 9.2 Brix Pressed cake from membrane press 32.5% dry matter Filter cake from sieve cabinet 15.0% dry matter

The slurry from the first pass was processed through the machine again at the second pass. The disc gap was set at 0.25 mm (10 mil) at this transition. The macerated slurry was compressed in a membrane press at 20 psi for 15 minutes.

Table 5

material concentration Juice from membrane press 7.6 Brix Pressed cake from membrane press 21.0% dry matter

(The lower solids content of the cake during the second pass through the membrane press was given by its greater thickness.)

The second pass vacuum dewatered slurry had a solids content of 22%. When washed in excess water and dewatered under vacuum, the solids content was only 15%.

This showed that two-thirds of the solids in the slurry were dissolved and easily washed out. The washed mash had a residual sugar content of 0.5%.

The second pass slurry had poor filtration parameters when subjected to vacuum on filter paper, but on a 0.5 mm sieve, the 25 mm thick slurry had a filtration rate of about 5000 gfd.

These studies gave the following results:

1. The disc refiner processed pulp with low power consumption (about 3 kWh / t).

2. The slurry had good filtration parameters under vacuum (5000 gfd (850 Imh) with 25 mm cake).

3. Vacuum filter cake (after washing) had low residual sugar content (around 0.5%) ·

4. The filter cake may be compressed to form a dried slurry as a by-product (about 30%).

5. The squeezed juice had satisfactory ultrafiltration parameters (25 gfd (43 lmh)).

6. Ultrafiltration well suppressed staining particles in the extruded juice (99%).

7. The ultrafiltration juice filter had good sugar parameters.

Example 3

For 30 minutes, 1361 kg (3000 lb) of beet was macerated in solid hammer mills to produce 1514 liters (400 gallons) of juice. Maceration consisted of two transitions. The first pass was through two crushers and two extractors and the second pass was through one crusher and two extractors. Excess water added to the hammer mills to facilitate the discharge of macerated beet diluted the juice to 4% KDS. The juice was filtered through a vibration sieve no. 200 mesh. There was no visible residue left on the site.

The juice was heated to 77 ° C (170 ° F) and ultrafiltered through a Koch HFK 131 ultrafiltration spiral membrane module with a 2.032 mm (80 mil) gap. The juice was heated to 77 ° C (170 ° F) and ultrafiltered through a Koch HFK 131 ultrafiltration spiral membrane module with a 2.032 mm (80 mil) spacer. The inlet and outlet pressures were maintained at 414 and 276 kPa (60 and 40 psig), respectively. The results are summarized in Table 6.

Table 6 Extruded juice ultrafiltration - Test and flow parameters and separation parameters

time (Min.) yield (%) temp. 7 ° C (° F) flow (LMH) RDS (%) Sucrose (%) coloration Increase. Filt. Art. Increase. Filt. Art. Increase. Filt. Art. (%) 0 0 80 (176) 135 4.6 4.3 6.5 78.7 80.6 4.3 76 946 6781 91.8 35 n -> J J 72 (161) 90 5.3 4.4 17.0 70.8 81.2 4.8 130 128 6313 96.0 50 50 74 (166) 90 6.4 4.6 28.1 61.1 81.5 4.2 208 396 5442 98.1 55 67 75 (167) 83 7.8 4.8 38.5 50.2 80.3 1.6 308 950 5103 99.0 70 83 72 (161) 45 12.1 5.4 55.4 35.6 78.0 2.3 588 757 10 335 99.2

Increase. means a filter residue, Filt. means filtrate and Art. means discarded.

Note: This test was performed to assess the ability to process worse beets. The input material used for this test had a significantly lower purity than normal beet, resulting in a lower purity of the filtrate and a higher coloration.

Example 4

A group of leaching experiments was performed using a centrifuge as the leaching apparatus. The macerated slurry was prepared by processing the beet with a hammer mill of the disintegration type from Rietz. The centrifuge was from American Machinery and had a metal basket with a diameter of 46 cm (18) and a depth of 25 cm (10) and was powered by an electric motor of 2 kW (3 hp) at 1700 rpm. Inside the basket, a filter cloth sleeve containing a filter cake was used as an insert.

22.7 liters (5 gallons) of macerated slurry were centrifuged for two minutes and the extracted juice collected. The cake was mixed again with an equal volume of water and centrifuged again. This procedure was repeated six times. At the end of each spin, samples of extracted juice and cake were taken. The results of one experiment are summarized in Table 7.

The results show that the sucrose content of the juice and slurry was reduced by half at each step. This is to be expected because the cake boFv is mixed with an equal volume of water at each step. The sugar content of the slurry after six steps was 0.03%. This corresponds to the extraction of 99.8% sugar in beets.

Table 7 Results of leaching experiment

Measurement no. juice mash RDS % purity sucrose (% RDS) sugar % Water % RDS % purity sucrose (% RDS) sugar % 1 21.6 89.7 19.38 70.9 2.7 87.1 1.67 2 9.0 89.9 8.09 78.3 1.4 80.3 0.88 3 4.4 90.1 3.96 80.9 0.7 75.9 0.43 4 2.1 86.6 1.82 81.7 0.4 54.2 0.18 5 U 79.3 0.87 82.8 0.4 24.9 0.08 6 0.5 74.3 0.37 82.6 0.2 21.1 0.03

Example 5

A short ultrafiltration / diafiltration filtrate juice extrusion test was performed to evaluate the possibility of pre-concentration using reverse osmosis. The ESPA type reverse osmosis spiral membrane from Hydranautics was used in the test and the osmosis was performed at 800 psi and 38 ° C (100 ° F). The flow and separation parameters recorded in this test are shown in Table 8.

Table 8 Reverse osmosis of extracted juice flow and rejection parameters

acquired (%) flow (LMH) RDS (%) Sucrose (% RDS) Increase. Filt. Zam. Increase. Filt. Zam. spraying 13.5 12.5 10 65 14.4 0.4 97.2 13.4 0.3 97.5 60 31 25.2 1.4 94.4 23.2 1.3 94.5

Example 6a

The cut beets were introduced to disintegrate into a Rietz hammer mill at a rate of 420 kg / h and from there to a Andriz Sprout-Bauer crusher to obtain a well macerated slurry. These fibers and juice were fed into a first Mercone centrifuge manufactured by Dorr-Oliver, equipped with a 150 µm conical sieve. The system was maintained at 65-70 ° C and the juice from the first centrifuge had 13-14 RDS.

The stream of macerated beet fibers from the first centrifuge was fed to a 50 µm countercurrent system and finally to a second Mercone centrifuge equipped with a 250 µm screen. This second centrifuge centrifuged the fibers and ensured that the residual beet fibers contained 5.7% sugar and 88% water. The juice was recycled from the second centrifuge and passed through the sieve system to the first centrifuge at an amount of 11-19 l / min (3-5 gallons / min). About 250 mg / kg (ppm) of antifoam oil (ΚΑΒΟ 580) was added to the juice, while hot water was added to the second centrifuge at 4 L / min (1 gallon / min). The juice temperature was adjusted to 70 ° C, pH adjustment was made by adding sodium hydroxide solution for maceration, and the pH of the final juice was adjusted as needed. The final macerated beet juice had 13.2 RDS (refractometric dry solids) and the pH was 6.4 (measured at ambient temperature). The apparent purity (Pol / Brix) was 82.6; the conductometric ash was 3.9% and the color was 29,900 icu. It contained 0.6% fibers.

Example 6b

The juice of Example 6a, at a temperature of 70 ° C, was led to a first ultrafiltration. It was a 3.7 m (12 ') membrane PCI module with tubular elements separating at 200,000 dalton molecular weights and a surface area of 2.7 m ² . The inlet pressure was on average 100 psi, the outlet pressure was 63 psi, and the flow rate was 537 rpm. The filtrate flow rate was 2.6 L / min (corresponding to 60 L / m ² h). The filtrate had 11.0 RDS, the pH was 6.5, the apparent purity was 83.8, the color was 4705 ic, and the conductivity ash was 4.9%. The filter residue was 11.1 RDS, the apparent purity was 74.4, the ash was 5.1%, and the color was 60,800 icu. A similar membrane in series diafiltered the filter residue with 1.0 L / min water and supplied an additional 1.9 L / min filtrate with 8 RDS.

Example 6c

The filtrate from the first ultrafiltration system was fed at 70 ° C to a second ultrafiltration system that comprised two 10 cm (4) Osmonics GN spiral membranes, cut off at a molecular weight of 3500 daltons, with a surface area of 12 m ² . The average inlet pressure was 448 kPa (65 psi), the outlet pressure was 345 kPa (50 psi). The total filtrate flow rate was 1.4 l / min on average, giving 7 l / m ² h. The filtrate was 8.6 RDS; pH was 7.0; the apparent purity was 83.6; the color was 1666 icu and the conductometric ash was 4.9% (5.4% sulfated ash). The filter residue was 14.2 RDS, the apparent purity was 83.3, the conductometric ash was 5% and the color was 13,800 icu.

Example 6d

The filtrate from the second ultrafiltration. membranes were passed through a cation exchange resin (Purolite C155S) in sodium form. The flow rate was 2.4 l / min and passed through 90 liters of resin at 1.6 bed volumes / h and at 70 ° C. The product was 7.1 RDS, at pH 6.4, the apparent purity was 83.5; the color was 1505 icu, and the conductometric ash was 5.6% (5.2% sulfated ash). The ionic composition of the resin inlet and outlet currents was according to Table 9.

Table 9

ca mg The On the CI P0 ₄ S0 ₄ oxalate spraying 0.003% 0,085% 0,97% 0,91% 0.49% 0.28% 0.091% 0.44% Product 0.001% 0.038% 0.87% 1.000% 0.52% 0,30% 0.089% 0.37%

Example 6e

The resin product stream was adjusted by nanofiltration on a Desal 5DL three-stage membrane. The total membrane surface was 18 m ² and the inlet pressure was 450 psi and 65 ° C. A stream of 2.6 L was injected and the filtrate flow was 1.0 L / min. The diafiltration water was fed between the stages at 0.3 l / min.

The filter residue (product) was 25.4 RDS, the apparent purity was 88.3, the color was 1154 icu and the ash was 2.9%. The filtrate was 1.8 RDS, the apparent purity was 12.0, the color was 3083, and the ash was about 20%.

For HPLC, the composition of the streams (% based on dry weight) was:

Table 10

sucrose glucose fructose rafinóza betaine spraying 82.9 0.22 0.75 0.52 1.83 The filtrate 18.7 0.63 3.62 0.09 7.11 Filtration residue 89.3 0.11 0.31 0.63 1.18

Example 6f

The product stream from the nanofiltration was evaporated to give a syrup of 70.5 Brix. Approximately 1 ml / min of ammonium bisulfite (ABS) solution was added to the juice feed to the evaporator. ABS was a 65% solution with a 1: 1 dilution. The evaporator was an APV unit with plate and frame and was operated at an absolute pressure of 55 kPa (8 psia) and the syrup temperature was 85 ° C. A stream of 1 L / min at 25.4 brix was injected.

The liquid produced by the evaporator was crystallized under vacuum to give a 10.2 g white sugar with 0.009% conductivity ash. Crystallization was carried out in a batch process in a crystallizer containing 50 liters of confectionery. The crystallizer was a pilot plant manufactured by Pignat from Genas, France. The crystallization pressure was 67.7 kPa absolute (20 Hg), the temperature was 70-75 ° C, and the crystallization lasted 2 hours. The sugar produced by crystallization was centrifuged on a centrifuge with a 0.6 m (2 ^L ) large, perforated basket. The mother syrup (separated by centrifugation) had an apparent purity of 81.8% and a coloring of 2988 ic.

Example 7 (alternative ion exchange treatment)

Second UF2 ultrafiltration stage, similar to that described in Example 6c above, but including two 10 cm (4) Osmonics GN spiral membrane modules (MWCO 3500 daltons) and two 10 cm (4) Osmonics GM spiral membrane modules (MWCO

3000 daltons) was used to process the juice from the first stage of ultrafiltration. This juice was originally made from macerated beets as described above. The modules operated at inlet pressures of 1103 and 1724 kPa (160 and 250 psi) on average and supplied a total of 2.5 L / min of filtrate (pH 6.5, RDS 9 and 1890 icu staining). The filtrate was treated with a cation exchange resin (Purolite PCR) in potassium form at 70 ° C and 0.9 bed volumes / h. The product had a pH of 7.0, RDS

8.9, purity 85.1 and coloring 1959. The inlet and outlet mixtures were as follows (% by dry weight):

Table 11

ca mg The On the ash Resin input 0.006% 0.158% 1,14% 0.67% 5.4% Resin product 0.006% 0.003% 3.39% 0.06% 7.8%

Example 8 (electrodialysis)

The product from the ion exchange resin in potassium form in Example 7 was treated by nanofiltration (performed as in Example 6e above). The product (filter residue) had an R.DS of 23, a purity of 89.5% (by HPLC), 4.5% as sulfated ash and a coloring of 1800 icu. It was electrodialysed in a series of 40 cationic and anionic membrane pairs, each pair having a membrane surface of 0.1 m ² . The membranes used were manufactured by Tokuyama Corp. from Japan, the anionic membrane was of type A £ 506sb, and the cationic membrane was of type CMXsb. The series was operated at 45-55 ° C, a voltage of 18-30 V, and a current intensity of 2-3 A. The anolyte and catholyte systems contained diluted amidosulfonic acid (conductivity 20 mS / cm) that circulated through the series at 3 g / m (11 L) / min). The treated stream was circulated at 8 to 10 g / m (30 to 38 rpm) and flowed through the system at 1 l / min. The concentrated stream was 0.5% sodium chloride solution. The electrodialysis product stream was at 94.4% purity (by HPLC) and had 2.2% sulfated ash (calculated from the cationic composition as shown below, where the ionic composition of the feed and product streams is expressed as% ions per dry weight).

Table 12

ca mg The On the ash spraying 0.002% 0.009% 1.86% 0.104% 4.5% Product 0.001% 0.003% 0.88% 0,079% 2.2%

The product from the experiment was evaporated and crystallized to a white sugar as in Example 6f. Upon evaporation (in the presence of ammonium bisulfite such that it was sufficient to produce 280 ppm residual SO), the product had an RDS of 70 and a coloration of 1700 icu. Crystallization under vacuum gave a white sugar with a coloring of 17 ic and a conductometric ash of 0.007%. The mother syrup (separated by centrifugation) had an apparent purity of 84% and a coloring of 4560 ic.

Example 9

The juice from the beet maceration system described in Example 6a was filtered in a spiral ultrafiltration membrane. Initially, pre-filtration was performed through a 200 µm bag filter to remove fibers that passed through the centrifuge screen. The membrane used was a 10 cm (4 inch) Osmonics JY spiral membrane with a membrane area of 4.8 m ² and a cut-out to a molecular weight of 100,000 daltons. The juice temperature was 60 ° C (140 ° F) and the inlet and outlet pressures were 345 and 207 kPa (50 psi and 30 psi). The feed rate was 3.6 l / min and the filtrate and filter residue flow was both 1.8 l / min at KDS 13 and 14.2 in both cases, giving a flow rate of 22.5 l / m.h at a concentration factor of 2. Coloring the feed rate was 1232 icu and the filtrate color was 6475 icu. This juice can be further processed to white sugar by steps 6c, 6d, 6e, and 6f.

Example 10

The juice containing the mixture of mother liquor from the crystallization of white sugar and the filter residue from the second ultrafiltration was evaporated to 60 KDS and passed at 0.9 L / h through a simulated moving bed separation system containing 5.8 liters of resin distributed between 10 cells. Water was added at 4 liters per hour and the system was operated at 70 ° C. Three fractions could be collected from the system, containing most of the organic matter, most of sucrose and most of raffinose and other organic materials.

·>>

J J

The typical properties of each of these fractions are shown below in Table 13. (Organic fractions represent the amount of material calculated from the difference in the analytical results).

Table 13

flow 1 / hour. RDS sucrose lnvert ash rafinóza organic phase coloration spraying 0.9 60 66.6 4.0 5.9 8.2 15.3 33 000 organic faction 0.7 1.1 13.2 9.8 16 0.0 61 29 700 Sucrose faction 1.84 29.3 96.0 0.7 0.2 3.1 0.0 6090 Rafinózová faction 2.5 8.4 13.7 9.8 16.6 20.4 39.5 90 300

The sucrose fraction obtained may have a purity of 96% and entail the recovery of 92.5% of the input sucrose

Example 11

450 g mother syrup from the first crystallization of white sugar (with 75 RDS, and containing

2.3% raffinose (dry matter) was diluted to 30 RDS with water. The pH was adjusted to 5.0 by addition of dilute sulfuric acid and the temperature of the solution was brought to 50 ° C. Added

2.5 x 10 ⁷ α-galactosidase enzyme pellet units (12.2 g) and the solution was mixed at 50 ° C for 2 h. The resulting juice contained 0.7% raffinose on solids.

Example 12

The mother liquor of crystallization of the first batch of white sugar (color 3147 icu at 83.1% apparent purity) was crystallized under vacuum to give a second batch of white sugar with 20 icu color and 0.01% conductivity ash. Crystallization was carried out in batches in a crystallizer containing 50 liters of confectionery. The crystallizer was a pilot plant manufactured by Pignat of Genas in France. The crystallization pressure and temperature were 67.7 kPa abs. (20 Hg abs.) And 70-75 ° C and crystallization lasted about 2 h. The sugar produced by crystallization was centrifuged on a centrifuge with a 0.6 m (2 ^L ) basket using a perforated basket. The mother syrup (separated by centrifugation) had an apparent purity of 81.1% and a coloring of 41.5%.

Example 13a.

Beet juice from the factory diffuser (4200 icu color) was fed to the first centrifuge (with a 150 µm sieve) to remove residual fibers, and heated to 70 ° C. Intensive aeration was performed, sieving through a sieve (50 µm) and adjusting the pH to 8.0 with sodium hydroxide. The resulting juice had 17.5 RDS, an apparent purity of 85.1, a coloring of 16,400 and a conductometric ash of 5.3. It contained 0.09% fibers.

The juice was led to a first ultrafiltration at 73 ° C in an Osmonics PW with a 10 cm diaphragm module (4) with spiral elements having a molecular weight cut to 10,000-15,000 daltons and a surface area of 4.3 m ² . The average inlet pressure was 455 kPa (66 psi), the outlet pressure was 310 kPa (45 psi), and the cross-flow was 193 l / min. The filtrate flow rate was 1.9 l / min (corresponding to 26 l / m ² .h). The filtrate was 15.5 RDS, the apparent purity was 85.6, the color was 6697 icu and the ash was 5.3%. The filter residue was

12.5 RDS and apparent purity was 83.4. Diafiltration of the filter residue using a PCI tubular membrane with cut parameters at 20,000 daltons produced an additional 1.6 L / min of filtrate per 7 RDS. The filtrates were mixed.

Example 13b

The combined filtrates from the first ultrafiltration system were routed at 65 ° C to the second ultrafiltration system using two 10 cm (4) Osmonics GK membrane spiral modules and two Osmonics GE types. These membranes have molecular weights cut at 2000 daltons and 1000 daltons. The system was operated at an inlet pressure of 1724 kPa (250 psi) on average and delivered a total of 2.2 L / min of filtrate (13.5 RDS, apparent purity was 85.0, conductometric ash was 6.5% and color was 3297 icu) . The filter residue was 21.4 RDS and the apparent purity was 83.8. The total membrane area was 24 m ² and the average flow rate was 5.5 l / m ² 'hr.

35a

Example 13c

The filtrate from the second ultrafiltration membrane system was treated with Desal DS5 type 2 10 cm (2) membrane nanofiltration. The total membrane surface was 12 m ² , the inlet pressure was 3103 kPa (450 psi) and the temperature was 66 ° C (150 ° F) ). The feed rate was 0.75 g (2.5 L / min) and the filter residue was 0.3 g (1 L / min).

The mother syrup (separated by centrifugation) had an apparent purity of 80.3% and the coloration was 5380 icu.

The diafiltration water was fed to the second stage at 10.4 l / h (2.75 gallons / h). The filter residue (product) stream had an RDS of 24.9. an apparent purity of 90.6 (90.8% HPLC), a 2802 icu color, and a conductivity ash of 4.2%. The filtrate had an RDS of 5.2 and an apparent purity of 38.3.

Example I3d

The nanofiltration residue of Example 13c was treated by electrodialysis in a series containing 40 cationic and anionic membrane pairs, each pair having a membrane surface area of 0.1 m ² . The series was operated at a temperature of 45 to 55 ° C with a voltage of 18 to 30 V and a current intensity of 2 to 3 A. The anolyte and catholyte systems contained diluted amidosulfonic acid (with a conductivity of 20 mS / cm) that circulated through a series of membranes / min (3 gallons / min). The stream to be treated was circulated at a flow rate of 30 l / min (8 gallons / min) and the apparatus was operated in batch mode. A series of membranes was operated at a temperature of 40 to 50 ° C at a voltage of 12 to 23 V and a current intensity of 3 A. The composition of the ionic mixtures at the inlet and for the product was as follows:

Table 14

% ash ca mg The On the Cl PO ₄ SO ₄ oxalates entry 0,001 0.12 0.65 0.61 0,049 0,146 0,523 0,628 3.9 Product 0,003 0.02 0.19 0.19 0,021 L 0,046 0,061 0,073 T2

The product had a purity of 92.5% (according to FfPLC)

35b

Example 13e

The electrodialysis product (after addition of 900 ppm SO ₂ as ammonium bisulfite solution) was evaporated to give a syrup having 69 Brix (3060 icu color). The evaporator was a single acting APV board and frame unit and was operated at a pressure of 55 kPa abs. (8 psia) and syrup temperature was 85 ° C. The evaporator feed was 1 liter / min at 24 Brix.

The evaporated syrup crystallized under vacuum to give a white sugar having a coloration of 17.3% and a conductivity ash of 0.007%. Crystallization was carried out in batch mode in a crystallizer containing 50 L of confectionery. The crystallizer was a pilot plant manufactured by Pignat from Genas, France. The crystallization pressure was 68 kPa abs. (20 Hg) and the temperature was 70-75 ° C and crystallization lasted 2 hours. The sugar produced by crystallization was centrifuged on a perforated basket centrifuge with a diameter of 0.6 m (2 ').

Example 13f

The mother syrup produced by the methods of Example 13e was further crystallized in a Pignat crystallizer at 68 kPa (20 Hg) absolute. and 70-75 ° C for 3 hours. The confection was centrifuged in a 0.6 m (2 ') centrifuge and a second sugar was obtained with a coloring of 40 ic and an ash of 0.019.

Example 14a

An amount of 208 liters (55 gallons) of fresh beet juice from the diffuser at 16.5 Brix and a color of 3850 icu was adjusted to pH 8 with sodium hydroxide solution. 2.2 liters of 3% (v / v) hydrogen peroxide (0.03) were added. % for juice or 0.19% for solids). The juice was heated to 80 ° C for 60 min, during which time the coloration increased to 14,000 icu. Ultrafiltration through a PCI tubular membrane cut at 4000 daltons, operating at 300 psi (2068 kPa) gave a 2100 icu filtrate and a 50,000 icu filter residue.

The filtrate was evaporated and crystallized under vacuum in an apparatus and under conditions similar to those of Example 13e. During this evaporation, a color was formed and a crystallization sugar having a coloration of 4450 icu was obtained. Spin and wash gave crystals with a coloring of 46 ic. In another experiment, 200 mg / kg (ppm) of SO ₂ was added to the crystallization to give crystals of 34 icu color from 3950 icu sugar confectionery.

Example 14b

The work of Example 14a was repeated, but the oxidation was sprayed with beet juice diffuser, which was heated and aerated as described in Example I3a. The color of the feed was 12,123 icu. Peroxide treatment increased it to 14 473 icu and ultrafiltration gave the filtrate at 2707 icu.

Example 15

The juice comprising the mixture of mother liquor from the crystallization of white sugar and the filter residue from the second ultrafiltration can be evaporated to 60 RDS and passed at 1.0 L / h through a simulated moving bed separation system containing 5.81 resins distributed over ten cells. Water can be sprayed at 4 L / h and the system can be operated at 70 ° C. Three fractions were collected from the system and contained most of the organic matter, most of sucrose and most of raffinose, and other organic materials, respectively. The typical properties of each of these fractions are shown in Table 15 below. (Organic matter represents the amount of material calculated from the difference from the analytical results.

Table 15

flow 1 / h RDS sucrose inverse ash rafinóza organic substances coloration icu spraying 1.0 60 67.5 5.0 6.2 7.4 17.3 37 000 organic faction 0.7 1.0 12 H 1 18.2 0.0 58 31 200 Sucrose faction 1.9 27.9 96.5 1.0 0.4 2.5 0.0 6900 Rafinózová faction 2.6 9.1 15.1 8.7 19.2 22.3 42.5 85 700

The sucrose fraction obtained generally has a purity of 96.5 and represents the recovery of 90.5% of the input sucrose.

Example 16

An amount of 500 g of mother liquor from the first crystallization of white sugar (with 75 ROS and containing 2.6% raffinose, based on dry matter) was diluted to 30 RDS with water. The pH was adjusted to 5.0 by addition of dilute sulfuric acid and the temperature of the solution was adjusted to 50 ° C. 2.5 x 10 ⁷ units of pelletized α-galactosidase enzyme (12.2 g) were added and the solution was stirred at 50 ° C for 2 h. The resulting juice was analyzed and found to contain 0.9% raffinose based on solids.

Example 17

The mother liquor from the first batch of white sugar crystallization (4094 icu color at 80.8% apparent purity) was crystallized under vacuum to obtain a second white sugar batch with 28 ic coloration and conductivity ash of 0.024%. Crystallization was carried out in a batch mode in a crystallizer containing 50 L of confectionery. The crystallizer was a pilot unit manufactured by Pignat of Genas in France. The crystallization pressure was 68 kPa (20 Hg) absolute, the temperature was 70-75 ° C, and the crystallization lasted about 2 hours. The sugar produced by crystallization was centrifuged on a centrifuge with a basket of 0.6 m (2 ') diameter using a perforated basket. The mother syrup (separated by centrifuge) had an apparent purity of 77.4% and a coloring of 5807 ic.

The above description of specific embodiments of the present invention is not intended to be a complete list of each possible embodiment of the invention. Those skilled in the art will appreciate that modifications may be made to the specific embodiments described herein, yet within the scope of the present invention.

Industrial usability

In the sugar industry in the production of sugar.

Claims (3)

PATTERN CLAIMS (modified) What is claimed is: 1. A method for producing sugar from beet comprising the steps of:. (a) either (1) maceration of beet or pieces thereof; or (2) cutting beet into chips; (b) separating juice from macerated beet or chips at a temperature of at least 80 ° C; and (c) membrane filtration of the separated juice to produce a filter residue and filtrate. 2. Process for producing sugar from beet comprising the steps of: (a) maceration of beet or pieces thereof; (b) mechanical separation of macerated beet juice at a temperature of at least 80 ° C; and (c) membrane filtration of the separated juice to produce a filter residue and filtrate. 10. The method of claim 2, wherein: and then macerates. i s a t ý m that the beets are cut into pieces Method according to claim 3, characterized in that disc mill. s a by that the maceration is performed in Method according to claim 2, characterized in that the juices are carried on a moving porous with countercurrent flow of macerated beet and water. mechanical separation vacuum filter belt Method according to claim 2 s a by mechanical separation is performed using centrifugation. Method according to claim 2, characterized in that the mechanical separation is carried out using vacuum filtration. Process according to claim 7, characterized in that the pH of the vacuum-separated juice is adjusted to at least 7 by the addition of sodium hydroxide. The method of claim 7, wherein the separated juice is contacted with an agent selected from the group consisting of sulfur dioxide. sulphate salts, sulphite salts, hydrosulphite salts and mixtures thereof in an amount sufficient to adjust the pH of the extracted juice to at least 7. The method of claim 2, wherein. characterized in that the membrane filtration is performed with an ultrafiltration membrane. The method of claim 2, wherein the membrane filtration is performed with a nanofiltration membrane. Method according to claim 10, characterized in that the membrane filtration is a cross-flow ultrafiltration and is carried out at least 80 ° C and the pH of the filtrate is at least 7. Method according to claim 2, characterized in that the filter residue from the membrane filtration is subjected to diafiltration to obtain residual sugar in the filter residue. 14. The process according to claim 13, wherein the diafiltration filtrate is combined with the membrane filtration filtrate for further processing. 15. The process of claim 2 wherein the membrane filtration filtrate is concentrated by reverse osmosis to form a concentrated solution. Process according to claim 15, characterized in that the concentrated solution is evaporated and sucrose is crystallized therefrom. 17. The method of claim 2, wherein the juice or filtrate is not contacted with lime or carbon dioxide. +0 18. A method for producing sugar from beet comprising the steps of: (a) cutting the beet into pieces, (b) maceration of beet pieces, (c) mechanical extraction of juice from macerated beet at a temperature of at least 80 ° C; d) membrane filtration of the extracted juice and forming a filter residue and filtrate. e) subjecting the filter residue to diafiltration, thereby forming a sugar-enriched diafiltration filtrate as compared to the filter residue, f) combining the diafiltration filtrate and the membrane filtration filtrate and the combined juice, (g) concentrating the combined juice by reverse osmosis to form a concentrated solution; and h) evaporating the concentrated solution and crystallizing the sucrose therefrom. 19. A method for producing sugar from beet comprising the steps of: (a) maceration of sugar beet or pieces thereof, thereby producing macerated material that includes slurry and liquid; b) separating the liquid in the macerated material from the slurry and forming sucrose containing feed juices; c) filtering the sucrose-containing inlet juices through a first ultrafiltration membrane having a first molecular weight cutoff and forming an ultrafiltration filtrate and a first ultrafiltration residue, d) filtering the first ultrafiltration filtrate through a second ultrafiltration membrane having a second molecular weight cutoff that is less than a first molecular weight cutoff to form a second ultrafiltration filtrate and a second ultrafiltration residue; and e) filtering the second ultrafiltration filtrate through the nanofiltration membrane and forming a nanofiltration filtrate and a nanofiltration residue wherein the nanofiltration residue has a higher dry matter-based sucrose concentration than the inlet juice in step c). 20. A method for producing sugar from beet comprising the steps of: y / (a) cutting sugar beet into slices and obtaining sucrose-containing inlet juice by diffusion therefrom; (b) filtering the sucrose-containing feed juice through a first ultrafiltration membrane that performs trimming to a first molecular weight and producing a first ultrafiltration filtrate and a first ultrafiltration residue; I (c) filtering the first ultrafiltration filtrate with a second ultrafiltration membrane that performs a cut at a second molecular weight that is less than that cut at the first molecular weight and produces a second ultrafiltration filtrate and a second ultrafiltration residue; and d) filtering the second ultrafiltration filtrate through the nanofiltration membrane and producing a nanofiltration filtrate and a nanofiltration residue, wherein the nanofiltration residue has a higher dry matter-based sucrose concentration than the inlet juice in step c). The method of claim 19 or 20, further comprising the step of purifying either the second ultrafiltration filtrate or the nanofiltration residue by at least one of the methods selected from the group consisting of ion exchange and electrodialysis. 22. The method of claim 21, wherein the nanofiltration residue is purified by electrodialysis to form electrodialysis juice and electrodialysis residue. The method of claim 22, wherein the electrodialysed juice is softened by ion exchange and a softened cleaned juice is formed. J 24. The method of claim 23, wherein at least 65% by weight of the Ca, Mg, K, Na and the inorganic and organic anions present in the second ultrafiltration filter are removed by nanofiltration, electrodialysis, and ion exchange. 25. The method of claim 19 or 20, wherein air is introduced into the inlet juice prior to the first ultrafiltration and the colored particles are polymerized. to The method according to claim 19 or 20, characterized in that hydrogen peroxide, ozone or a combination thereof is introduced into the inlet juice before the first ultrafiltration. A method according to claim 19 or 20, characterized in that the pH of the juice is adjusted to a value of 6 to 8 by adding a base before the first ultrafiltration. 28. The method of claim 19, wherein, after liquid separation, no more than 5% of the sucrose present in the beet remains in the slurry. 29. The process of claim 28 wherein no more than 3% of the sucrose present in the beet remains in the slurry after liquid separation. The method according to claim 19 or 20, further comprising the step of removing the remainder of the beet and sludge fibers from the separated liquid by at least one of a method selected from the group consisting of screening and filtration prior to the first ultrafiltration. The method of claim 30, characterized by. filtration removes at least 90% by weight of all the largest dimension of at least 150 µm. A method according to claim 31, characterized in that. filtration removes at least 90% by weight of all the largest dimension of at least 50 µm. that the screening or the fibers and sludge have that the screening or the fibers and sludge have Method according to claim 19, characterized in that the beets are macerated by a hammer mill and converted into a mixture of slurry and a sucrose-containing liquid. The method of claim 33, wherein the macerated beet is also passed through a crusher. 1b The method of claim 33, characterized in that it is separated from the slurry by centrifugation. The method of claims 19 or 20, wherein the first ultrafiltration residue is diafiltered through at least a first diafiltration or ultrafiltration membrane, and a first diafiltration filtrate and a first diafiltration residue and a first diafiltration residue are filtered through a second ultrafiltration membrane. 37. The method of claim 36, wherein the second ultrafiltration residue is diafiltered through at least a second diafiltration or ultrafiltration membrane and a second diafiltration filtrate and a second diafiltration residue are produced and wherein the second diafiltration filtrate is filtered through a nanofiltration membrane. The method of claims 19 or 20, wherein at least two of the first ultrafiltration residue, the second ultrafiltration residue, the nanofiltration filtrate and the electrodialysis concentrate or residue are combined and molasses is produced. 39. The method of claim 37, wherein at least the first diafiltration residue, the second diafiltration residue, and the nanofiltration filtrate are combined and molasses is produced. The method of claims 19 or 20, further comprising evaporating the nanofiltration residue to produce a concentrated syrup and crystallizing white sugar from the concentrated syrup. 41. The method of claim 23, further comprising evaporating the purified juice and producing a concentrated syrup and crystallizing white sugar from the concentrated syrup. 42. The method of claim 41, wherein the clarified juice has an ash concentration of at most 2.5% by weight based on the dry matter base. 43. The method of claim 42, wherein the purified juice has an ash concentration of at most 2.0% by weight, based on the dry basis. is that the liquid is w 44. The method of claim 41, wherein the clarified juice has an ash concentration of at most 1.0% by weight based on the dry basis. 45. The process of claim 41, wherein the process comprises two crystallizations of white sugar from concentrated syrup. 46. The process of claim 40 wherein the mother liquor remains from the concentrated syrup after crystallization of the white sugar and is recycled to one of the ultrafiltration membranes. 47. The process of claim 41 wherein the mother liquor remains from the concentrated syrup after crystallization of the white sugar and is recycled to one of the ultrafiltration membranes. A method according to claims 19 or 20, characterized in that during filtration through the first ultrafiltration membrane, the inlet juice is at a temperature of 60 to 93 ° C. The method of claim 48, wherein the inlet juice has a temperature of 71 to 85 ° C during filtration through the first ultrafiltration membrane. Method according to claim 19 or 20, characterized in that the first ultrafiltration membrane cuts to a molecular weight value of at least 2000 daltons and a pore size of at most 0.1 μιη. 51. The method of claim 50, wherein the first ultrafiltration membrane cuts to a molecular weight of 4000 to 200,000 daltons. The method of claims 19 or 20, wherein the first ultrafiltration filtrate has a coloring of 3000 to 10,000 icu. The method of claims 19 or 20, wherein the second ultrafiltration membrane cuts to a molecular weight of 500 to 5000 daltons. The 54. The method of claim 53, wherein the second ultrafiltration membrane is cut to a molecular weight value of 1000 to 4000 daltons. 55. The method of claims 19 or 20, wherein the second Even the ultrafiltration filtrate has a coloration of not more than 4000 icu. The method of claims 19 or 20, wherein the second ultrafiltration filtrate has a coloration of not more than 2500 icu. A method according to claim 19 or 20, wherein the nanofiltration filtrate comprises at least 30% by weight, based on the dry matter base, of ash in the inlet juice. 58. The method of claim 19 or 20, wherein the nanofiltration filtrate comprises at least 30% by weight, based on dry basis, of the inverse sugars present in the inlet juice. A method according to claim 19 or 20, wherein the nanofiltration filtrate comprises at least 25% by weight, based on dry basis, of betaine present in the inlet juice. The method of claims 19 or 20, wherein at least one of the aqueous streams selected from the group consisting of inlet juice, the first ultrafiltration filtrate, the second ultrafiltration filtrate and the nanofiltration residue is contacted with an agent selected from the group consisting of sulfur dioxide, sulphite salts, hydrosulphite salts, metabisulphite salts, dithionite salts and mixtures thereof in an amount sufficient to ensure an equivalent sulfur concentration in the stream of at least 100 mg / kg. 61. The method of claim 23, wherein at least one of the aqueous streams selected from the group consisting of inlet juice, first ultrafiltration filtrate, second ultrafiltration filtrate, nanofiltration residue and purified juice is contacted with a reagent selected from the group consisting of sulfur dioxide, sulphite salts, hydrosulphite salts, metabisulphite salts, dithionite salts and mixtures thereof in an amount sufficient to provide an equivalent sulfur dioxide concentration in the stream of at least 100 mg / kg. A method according to claims 19 or 20, characterized in that no filtrate comes into contact with the lime and carbon dioxide. 63. The method of claims 19 or 20, further comprising the step of introducing enough air into the inlet juice and co-polymerizing the colored particles prior to filtration through the first ultrafiltration membrane, wherein at least a portion of the colored particles are removed from the juice by filtration through the first ultrafiltration membrane. 64. The method of claim 63, further comprising heating the juice to a temperature of 60 to 93 ° C prior to filtration through the first ultrafiltration membrane. 65. A method for producing beet sugar, comprising the steps of: (a) macerated sugar beet or pieces thereof, and forming a slurry comprising an aqueous liquid containing sucrose; (b) separating the sucrose-containing liquid from the slurry; (c) filtering the sucrose-containing liquid through a first ultrafiltration membrane which cuts off the molecular weight at 4000 to 200 000 daltons and producing a first ultrafiltration filtrate having a coloration of not more than 10 000 icu and a first ultrafiltration residue, d) filtering the first ultrafiltration filtrate through a second ultrafiltration membrane which cuts off to a molecular weight of 2000 to 4000 daltons to produce a second ultrafiltration filtrate having a coloration of not more than 4000 icu and a second ultrafiltration residue, e) filtering the second ultrafiltration filtrate through the nanofiltration membrane and producing a nanofiltration filtrate and a nanofiltration residue, wherein the nanofiltration residue has a higher dry matter-based sucrose concentration than the sucrose-containing liquid in step b), h} f) purifying the nanofiltration residue by at least one method selected from the group consisting of ion exchange and electrodialysis, and producing an evaporator feed, (g) evaporating water from the evaporator feed to produce concentrated syrup; and (h) crystallizing the white sugar from the concentrated syrup resulting in the mother syrup, the mother syrup being sufficiently pure to allow at least a second batch of high-purity white sugar. 66. A method for producing sugar from sugar beet, comprising the steps of: (a) cutting sugar beet into pulp and obtaining sucrose-containing feed juice by diffusion; (b) filtering the sucrose-containing inlet juices through a first ultrafiltration membrane cut off to a molecular weight in the range of 4000 to 200 000 daltons and producing a first ultrafiltration filtrate having a coloration of not more than 10 000 icu and a first ultrafiltration residue; (c) filtering the first ultrafiltration filtrate through a second ultrafiltration membrane which cuts off to a molecular weight of 2000 to 4000 daltons and produces a second ultrafiltration filtrate having a coloration of at most 4000 ic and a second ultrafiltration residue, d) filtering the second ultrafiltration filtrate through the nanofiltration membrane and producing a nanofiltration filtrate and a nanofiltration residue, wherein the nanofiltration residue has a higher solids-based sucrose concentration than the sucrose-containing liquid in step b), (e) purifying the nanofiltration residue by at least one method selected from the group consisting of ion exchange and electrodialysis and producing an evaporator feed, (f) evaporating the water from the feed into the evaporator and producing concentrated syrup; and (g) crystallization of white sugar from concentrated syrup, resulting in mother syrup, the mother syrup being sufficiently pure to allow at least a second batch of high-purity white sugar. 67. The method of claim 65 or claim 66, wherein the method comprises at least two crystallizations of white sugar from concentrated syrup. Ii 68. The method of claim 65 or claim 66, wherein the mother liquor produced in the crystallization comprises raffinose and at least 75% by weight of raffinose is removed from the mother liquor in a simulated moving bed chromatographic separator and the treated mother liquor is recycled. 69. The process of claim 68 wherein the recycled mother liquor is subjected to further purification by evaporation and crystallization. 70. The method of claim 65 or claim 66, wherein the mother liquor produced by crystallization comprises raffinose and at least 75% by weight of raffinose is removed from the mother liquor using the melibiase enzyme and the treated mother liquor is recycled to the feed of the second ultrafiltration membrane. 71. A method for purifying sucrose-containing juice obtained from sugar beet, comprising the steps of: (a) introducing a quantity of air into the juice sufficient to cause the polymerisation of the colored particles; and (a) removing at least some of the colored particles from the juice by membrane filtration, where the membrane filtration comprises: filtering the juice through a first ultrafiltration membrane that cuts to a first molecular weight to produce a first ultrafiltration filtrate and a first ultrafiltration residue, filtering the first ultrafiltration filtrate through a second ultrafiltration membrane that cuts to a second molecular weight that is less than the first cut molecular weight thereby producing a second ultrafiltration filtrate and a second ultrafiltration residue and filtering the second ultrafiltration filtrate through the nanofiltration membrane to produce a nanofiltration filtrate and a nanofiltration residue. 72. The method of claim 71, further comprising heating the juice prior to step b) to a temperature of 60 to 93 ° C. 73. The method of claim 71, wherein the membrane filtration comprises: filtering the juice through a first ultrafiltration membrane that cuts to a first molecular weight and produces a first ultrafiltration filtrate and a first ultrafiltration residue, filtering the first ultrafiltration filtrate through a second ultrafiltration membrane that cuts to a second molecular weight that is less than the first molecular weight for trimming, thereby producing a second ultrafiltration filtrate and a second ultrafiltration residue, and filtering the second ultrafiltration filtrate through the nanofiltration membrane, thereby producing a nanofiltration filtrate and a nanofiltration residue.