CZ2002570A3 - 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

Method of membrane filtration of sugar beet

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 is to clean the beet, cut it into pulp, extract the juice from the pulp diffusion, purify the juice by clarifying with lime and carbonation, concentrating the juice by multiple evaporation, boiling the concentrated juice in stages.

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 pass through, 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 problems caused by polysaccharides and proteins that include high molecular weight compounds.

In the conventional process, the purification of beet juice is based on lime treatment. Lime is used in the lime purification process for many purposes. 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 in extracting beet juice has its drawbacks. It has a long retention time that promotes microbial growth, resulting in loss of sugar and formation of undesirable compounds. It is difficult to raise the temperature of the cut cuttings fast enough 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 retained in the diffusion process by the cell walls is released during compression and mixed with the diffusion juice. This partially negates the advantages of the selective diffusion method.

The conventional lime clarification method uses large amounts of lime, which is up to 2.5% of the total weight of the processed beet. Sugar factories therefore operate lime burning ovens and transport the limestone over long distances. Waste from lime clarification and carbonation, consisting of used lime and separated impurities, is disposed of as waste. The production of lime and the disposal of refining waste are expensive operations. Waste disposal is becoming increasingly difficult and expensive in many communities.

Conventional complete filtration is not able to separate sucrose from macromolecular impurities in sugar beets. Several methods of using microfiltration and ultrafiltration to purify lime-reduced juice are also described, but these methods generally include embedding. 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 extracting sugar from beets that 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 cuttings, b) separating the juice from the macerated beet or cuttings and c) membrane filtration of the separated juice 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, thereby differing from the simple diffusion method used in the prior art processing technology to obtain pulp juice.

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 to perform vacuum extraction of the juice 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 around 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.

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 a pH of the ultrafiltration filtrate of 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 filtration filtrate for further processing.

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

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

One specific preferred embodiment of the method comprises the steps of: a) cutting the beet into pieces, b) macerating the beet pieces, c) mechanically extracting the juice from the macerated beet, d) sulfurizing 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 the 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 and j) evaporating the concentrated solution and crystallizing sucrose therefrom.

This embodiment of the present invention has many advantages over the conventional process using diffusion, lime clarification and carbonation. 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 cleaning produces from sugar beet juice which is less colored than traditional diffusion and carbonation. The smaller color of the juice allows for less washing ····························· Membrane filtration removes macromolecules in the beet juice so that a syrup of lower viscosity is produced. Lower viscosity syrups crystallize faster and are more readily extruded from the surface of sucrose crystals. A low colored, low viscous syrup reduces recycle during the crystallization process, resulting in better sugar recovery.

The method excludes a lime burning furnace, limestone extraction and all associated equipment, processes, products, by-products and waste products. Sodium hydroxide to neutralize juice costs about half of what lime it replaces. Sodium hydroxide is easier to handle, cleaner and less abrasive for the plant than lime.

The present invention also greatly reduces wastes that cause environmental pollution. In a conventional manner, a filter cake is produced which includes lime clarification products and impurities removed from the juice. This cake is placed in ponds or landfills. The proposed method completely eliminates the need for disposal of such materials. Invert 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 inlet juice obtained from sugar beet is filtered through a first ultrafiltration membrane which 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 which produces a cut at a second molecular weight that is lower than the cut at the first molecular weight level. This second ultrafiltration step creates a second ultrafiltration filtrate and a second ultrafiltration residue. The second ultrafiltration filtrate is nanofiltrated through the nanofiltration membrane, thereby forming 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 evaporation 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, thereby forming a macerated material comprising a slurry and a liquid and then separating the liquid contained in the macerated material from the slurry, for example by one or more operations. , conventional filtration or sieving. In one particular embodiment, the beet is macerated such that it first passes through a hammer mill and optionally thereafter passes through a grinding machine, where the beet is · Converts beet into a mixture of slurry and sucrose-containing liquid. After separation of the liquid from the slurry, no more than about 5 wt. sucrose, preferably no more than about 3%.

After separation of the fibrous slurry from the liquid and prior to the first ultrafiltration, the method may optionally include an additional step or steps to remove the remaining beet and slurry fibers from the separated liquid (juice). This can be done by sieving or filtration. Preferably, the sieving 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 another embodiment of the invention, the beet is cut into cuttings at the maceration site and the sucrose-containing inlet juice is extracted from it by diisium.

It is also possible to introduce air into the inlet juice prior to the first ultrafiltration to oxidize the color-forming materials. This oxidation, which increases the color of the juice, causes the color-forming materials to polymerize, which facilitates their removal by subsequent ultrafiltration. (Where the present patent refers to the polymerization of color-forming materials, this is believed to include 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 6 to 8 prior to ultrafiltration, for example by adding 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 the pore size is not greater than about 0.1 µm. Preferably, it is cut to a molecular weight of about 4000 to 200,000 daltons. The ultrafiltration filtrate of the first ultrafiltration preferably has a coloration of about 3000 to 10,000 icu. (All color values listed here are determined on the ICUMSA scale.)

The process of the present invention can be operated under a variety of process conditions. An example of such 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 cuts to a molecular weight of 500 to 5000 daltons, preferably to 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 weight at 3500-4000 daltons and the second stage using an ultrafiltration membrane making a cut at a molecular weight less than 3500 daltons. Preferably, the second ultrafiltration filtrate has a coloration that is no more intense than the second ultrafiltration filtrate. • · · · · · · · · · · · · · · ·

4000 icu, 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 in the sense of ultrafiltration, which uses water added to the inlet to aid in 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 the 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, thereby forming the electrodialysed juice and the electrodialysed residue, and then the electrodialysed juice is purified by ion exchange, thereby producing the purified juice. Preferably none of the filtrates is 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 and / 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 the remaining 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% by weight. solids ash, at least 30% invert and at least about 25% betaine present in the inlet juice.

The purified 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, more preferably not more than 2%, most preferably not more than 1.0%.

After membrane filtration steps (and electrodialysis and / or ion exchange steps), water from the purified juice may be evaporated to produce a concentrated syrup (e.g., with 75% dry matter). 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 lower the raffinose content.

Optionally, the method may comprise sulfurizing one or more process streams. In particular, the at least one aqueous stream selected from the group consisting of inlet juice, ultrafiltration filtrate from the first ultrafiltration, ultrafiltration filtrate from the second ultrafiltration, nanofiltration residue from nanofiltration, and evaporator feed may be contacted with an agent selected from the group consisting of sulfur dioxide, sulphite salts, bisulphite salts, metabisulphite salts, dithionites and mixtures thereof, in quantities sufficient to provide 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) macerating 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 obtaining a sucrose-containing feed juice from it),

c) filtering the sucrose-containing liquid through a first ultrafiltration membrane which cuts at a molecular weight of 4000 to 200,000 daltons, thereby forming 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, which cuts at a molecular weight of 2000 to 4000 daltons, thereby forming 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 nanofiltration, wherein the nanofiltration residue has a higher solids-based sucrose concentration than the sucrose-containing liquid in step (b),

f) purifying the nanofiltration residue from the 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 feed to the evaporator to form a concentrated syrup; and

h) crystallizing white sugar from concentrated syrup.

Optionally, 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) treating the mother liquor from the second crystallization by chromate separation or raffinose removal enzyme; and

k) recycling the treated mother liquor back into the feed stream to 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 the steps of:

(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 at least one 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 in waste products that cause environmental pollution. The conventional method produces a filter cake that includes lime clarification products and impurities removed from the juice. This cake is bound to ponds or landfills. The proposed method completely eliminates the need for 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 refineries. ····· «·· * ·· ···· processing sugar beet.

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 matter basis), more preferably to 1.5% or less, most preferably to 1% or less. This reduction in ash content is important because 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 can primarily eliminate the need for removal of sugar from molasses streams. Effective membrane filtration steps prevent large amounts of sugar from entering the molasses streams.

The present invention further provides an economical and reliable method of removing color-forming materials from beet juice. It can also reduce the formation 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 embodiments of the present invention in which the beet is macerated.

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

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. 1.

Beet coming from the field is stored in the storage area 10. As a rule, fresh beet is used in the process, but frozen beet can also be used. The beet from the storage area 10 sails to a conventional washing machine 12 in which dirt is removed from the beet surface. The washed beet emerging from the scrubber 12 passes through a conveyor 14 where the water is removed. The streams of wash water 18 and the float water 16 collected from this apparatus are discharged to the treatment ponds 20 for treatment. · · · ····· · · ····· · · ··· ···· waste water.

The backed beet 21 is conveyed by a conveyor device 22 to a cutting device 24, such as a hammer mill or cutter, in which the beet is cut into pieces, for example, pieces having an average thickness of 25 mm (1 inch). A stream of beet pieces from the cutter (or alternatively whole beet 21) is fed to the maceration apparatus 28. The maceration apparatus 28 may include, for example, one or more hammer mills (preferably with fixed blades) which use a set of rotary blades mounted on a horizontal shaft to push the beet through the extruder screen. The other maceration device may include one or more disk mills that use disks as the primary disk mill device. The discs preferably have grooves therein to facilitate maceration and the discs may be in a horizontal or vertical position. Disc mills are currently preferred to hammer mills, although it is possible to use both mills one after another (eg as a hammer mill followed by a disc mill). Extracted juice 28 or water stream 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 belt. 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 into this extraction apparatus 32 are countercurrent to each other. The juice stream 36 is reintroduced above the belt, preferably at several locations. This countercurrent filtration method produces a stream of low sugar slurry 68 and stream 38 of high sugar extracted juice. The countercurrent vacuum filtration process is preferably carried out at an elevated temperature of about 80 ° C to control microbial growth and improve juice extraction.

A separating centrifuge or series of separating centrifuges may 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 introduced into the basket and fixed the 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 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 content of sucrose, but high. ··· water content. It is compressed in a screw press 70 to extract and dilute the compressed juice 72 which contains about 1% dissolved solids and about 99% water. Dissolved solids consist of about 50% sucrose and 50% other than sugars. This diluted squeezed juice 72 is heated to a temperature of about 80 ° C in the heater 74 and then returned to the extraction apparatus 32 as a juice stream 36. The pressed slurry 76 is used as an animal feed, but may or may not be dried.

The extracted juice 38 is sent to a tank 41 and may optionally be sulfurized by adding sulfur dioxide or sulfite or hydrosulfite salts to 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. Sulfurization may take place during cutting, maceration, juice extraction, or at other points in the process as an alternative to or in addition to a particular sulfurization step of this embodiment. This sulfurization avoids the increase in coloring that would otherwise occur during the operations after membrane filtration and evaporation. Other antioxidants may also be used.

The juice is then neutralized by adding an aqueous solution of sodium hydroxide 42, preferably to a pH of at least 7, in the neutralization tank 43. This pH adjustment helps to prevent the inversion of sugars that occurs at elevated temperature. Other chemicals, such as liquid potassium hydroxide or granular sodium carbonate, can also be used to adjust the pH.

The juice extracted from the macerated beet by means of 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 may then be passed through a heater 44 to raise its temperature to about 0 ° 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. 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 are about 90% sucrose and 10% are non-sugars. The ultrafiltration filtrate 48 preferably has a temperature of about 80 ° C and has a pH of at least 7.

The filtrate from ultrafiltration has the equivalent purity of sucrose as the diluted juice produced by a conventional sugar process, which is about 90%, but there are important differences between. · Non-sugars in both products. · · Nec uk uk nec · nec nec nec 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 clarification process that sends the reaction products of lime and inverted sugars to the waste disposal system. Lower levels of the macromolecular compounds result in 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 color value on the same scale below 2000. It is equivalent to or better than the color value of the thin juice prepared in a conventional manner. Lower coloring in combination with lower viscosity results in an easier way to cook sugar. The result is higher sugar extraction, more efficient sugar cooking and less sugar loss in molasses.

A variety of membrane arrangements can be used in the present invention, including, for example, spiral, hollow fiber and tube membranes. Membranes suitable for this separation process should have two unique properties. They should have a high permeability to water and sucrose, but low permeability to coloring agents and other macromolecular compounds. Dense ultrafiltration membranes cutting the molecular weight between 1000 and 10,000 and thin nanofiltration membranes with about 10% NaCl rejection are well suited for this application. Membranes having a negative surface tension are preferred 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 the sucrose diafiltrate, the ultrafiltration residue 50 is passed through a membrane system 52 with the addition of water 54. This diafiltration extracts most of the sugar remaining in the ultrafiltration residue. Diafiltration filtrate 56 contains about 3% dissolved solids and about 97% water. Dissolved solids in the diafiltrate include about 88% sucrose and 12% non-sugars. The temperature of the diafiltrate 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. It is concentrated by evaporation and used as animal feed, either mixed or not mixed with the 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 flow through the membrane, to pre-concentrate the diluted sucrose solutions, which 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 diafiltration process 52.

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

Part of the apparatus used in the method of FIG. 1 is of the conventional type and is well known to those skilled in the art. These include beet washing equipment, pulp presses and evaporators. The beet cutting apparatus and maceration apparatus 28 are commercially available from suppliers such as H. Putsch GmbH & (Hagen, Germany), Maguin Company (Charmes, France), Dakota Machine Inc. (West Fargo, North Dakota, USA) and The Fitzpatrick Company (Elmhurst, Illinois, USA). A suitable juice extraction belt apparatus 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 SilverWeibull (Hasslehom, Sweden). Suitable membrane filtration systems are available from suppliers such as CeraMem Corp.. (Waltham, Mass., USA), Koch Membrane Systems, Inc. (Wilmington, Massachusetts, USA), and Osmonics, Inc. (Minneton, Minnesota, USA).

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

v * · ·

Table 1

No 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 Dec 75 8 71 (161) 58 8 20 May 8 71 (161) 64 20 May 90 8 71 (161) 66 3 88 8 71 (161) 72 1 50 6 38 (100)

Many variants are possible in the method. Suitable variants include reverse osmosis prior to ultrafiltration, sulphurization 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 presently preferred that the process is operated 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 sulphurization can be reduced or eliminated. It is also possible to operate different unit operations at somewhat different process parameters than those shown in the above-described embodiment or in the following examples.

It has been shown that by leaching macerated beet, it is possible to obtain 99.8% of sugars in six stages, each using fresh water. It has also been shown that juice ultrafiltration is able to achieve a yield of 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% RDS and 89% sucrose purity and with an estimated sugar yield of about 99.5% in both extraction and diafiltration operations.

»9 _{β β β β β β β β β β β β β β β β β β β β β β β}

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, UFP stands for ultrafiltration permeate, UFR stands for ultrafiltration retentate, DFP stands for diafiltration permeate, DFR stands for diafiltration retentate, MP stands for mixed filtrate ( 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 which is five times its volume. Combined ultrafiltration and diafiltration yield about 99.5% of the sugar in the feed.

In the method of Figure 2, several improvements can be made. 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 later stage diafiltration filtrate 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 conveying 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 method of the present invention can be operated in batch mode, it is particularly suitable for continuous operation.

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

The washed beet is led through a conveyor to the maceration apparatus. The maceration apparatus may comprise, for example, one or more hammer mills 112 and one or more crushers 114. Suitable hammer mills 112 may use a set of rocking blades mounted on a vertical shaft that push the beet material through the outlet screen. Another suitable type · »a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a The hammer mill 112 uses fixed blades. Another suitable maceration apparatus includes one or more disk mills that use disks as the primary disintegration device. The disks 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 by a hammer mill followed by a disc disintegration mill) or it is possible to have only one type of mills, i.e. a 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 exiting the crusher comprises slurry (i.e. beet fiber) and an aqueous liquid containing sucrose as well as 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 exiting the crusher 114 passes through a divider 120 to separate the liquid from the fibrous slurry. Suitably, the divider 120 may be a centrifuge, filter, or screen (eg, a rotary or vibrating screen, or a Dorr-Oliver DSM screen), or a combination of two or more such apparatuses. In an embodiment of the method illustrated in FIG. 3, the divider 120 comprises a centrifuge 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 countercurrent flow of aqueous liquid to help remove sucrose residues from the slurry. These screens 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 second end sieve 128 then passes to the centrifuge 134 where the low water slurry material 136 and juice obtained 138 the latter being fed in countercurrent to the slurry through a series of second sieves 128 and first sieves 126. This centrifuge 134 debugs the slurry. Liquid 119 may be withdrawn from one of the sieves, usually from the first sieve 126, and passed into the juice stream before the centrifuge 120. Optionally, an anti-foaming additive may be added to the juice by streams of fibers to reduce foaming.

For the low water slurry 136, a portion of its remaining 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 remaining fiber 144 remaining after compression can be used as animal feed.

Optionally, an air stream 146 may be admitted into the juice stream 124 exiting the centrifuge 120. This will oxidize the coloring materials in the juice (eg, it will increase the coloration from 8000 to 16 000), which helps in the formation of polymerized color bodies and hence the "9" · · · · · Ňuje usnad ňuje ňuje ňuje ňuje ňuje ňuje ňuje · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · It is also possible to inject a stream 148 of hydrogen peroxide solution in addition to or instead of injecting air. Hydrogen peroxide also aids the oxidation and polymerization of color-forming 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 pre-filtered 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 μιη and removes, by weight, most of the fibers and sludge remaining in the juice.

The heated and crushed juice 152 may optionally have its pH adjusted by adding a stream 154 that includes, for example, an aqueous solution of sodium hydroxide, calcium hydroxide, or magnesium carbonate. This pH adjustment helps to prevent the inversion of sugars that can occur at elevated temperature. Other chemicals, such as liquid potassium hydroxide or granular 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 juice after adjustment of the pH, referred to herein as the juice 156 entering the 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 µm, 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 suitably have a pore size / cut This first diafiltration 164 forms the first diafiltration filtrate 168 and the first diafiltration residue 170 (also called molasses 1 stream). Diafiltration minimizes the amount of sucrose lost in molasses (i.e., dry solids basis (dsb) concentration) is lower in the first diafiltration residue 170 than in the inlet 162. This is to be understood as having several stages of ultrafiltration 158 or diafiltration 164.

The first ultafiltrate 160 will generally have a coloring of 3000 to 10,000 icu. First ultrafiltration 4 44 4 4 4 4 4 4 4 4 4 The filtrate 160 and the first diafiltration filtrate 168 are combined to form a feed 172 for the second ultrafiltration membrane 174.

A sulfur stream 176 may be injected into the juice 172 before the second ultrafiltration. The stream 176 may include, for example, sulfur dioxide or a sulfite, hydrosulfite, metabisulfite or dithionite salt, such as an aqueous solution of ammonium bisulfite or sodium bisulfite (e.g. at a concentration of 35-65%). Preferably, the residual level of sulfur dioxide in the juice after sulfurization is at least 100 mg / kg (ppm). Sulfurization can 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 separation from the slurry, in the inlets for the first and second filtration or nanofiltration, or in the evaporator feed. Most preferably, the sulfurization is carried out by spraying on the second ultrafiltration. This sulfurization will prevent intensification of coloration that otherwise can occur during membrane filtration and evaporation operations. Other antioxidants as well as anti-foaming agents may be used.

The second ultrafiltration membrane 174 is preferably 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, i.e. cut to a molecular weight that is lower in pore size than it is. in 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 passed 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 ranging from 1500 to 3500, in some cases less.

Optionally, the second diafiltration filtrate 188 or the first diafiltration filtrate 168 may be recycled to the diafiltration water streams.

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 illustrated in FIG. 4. This chromatographic separator 236 is preferably a multistage unit with three to twenty stages, more preferably ten stages. It preferably has three product sections, 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 strongly 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 impurity removal.

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

The nanofiltration membrane coating typically comprises about 84% sucrose, 3-6% ash and about 0.5-4.0% inverse sugar (all on a dry weight basis). The nanofiltration membrane 190 divides the feed into a nanofiltration filtrate 196 (also called a third molasses stream) and a nanofiltration residue 191 that will contain most of the sucrose from the beet. The nanofiltration filtrate preferably comprises at least 30 to 60 wt. % ash (mainly Na, K, and Cl), at least 30 to 50 wt. % of inverted sugar (glucose and fiructose), and at least 25 to 50 wt. of 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. (on a dry weight basis) of 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 undesired discoloration. Electrodialysis ensures good removal of oxalic acid and malic acid, the total ash removal being generally 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 present. Therefore, the purified electrodialysis juice 193, which typically contains 92 to 94% sucrose based on dry matter, 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 is preferred, with crosslinking in the range of 4 to 10%. 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 basis), 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 substantially parts of water. Optionally, a 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 to form a first group 210 of precipitated white sugar crystals. The crystals 210 are centrifuged on a centrifuge 212. washed with water to remove the remaining liquid and the remaining 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 methods, the crystals formed in 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 wt. ash, more preferably less than 0.01% ash and less than 35% coloration.

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 Figure 4) (also leading to dilution of the raw material to 60 Brix), or alternatively by enzymatic digestion of raffinose 228 (see Figure 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 to hydrolyze raffinose is α-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 stages of ultrafiltration, nanofiltration, diafiltration, ion exchange and / or electrodialysis. For example, the first ultrafiltration shown in Fig. 3 could take place in two or more ultrafiltration stages 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 illustrated in the figure are also possible. It should also be understood that the process can be carried out at a variety of temperatures and other process conditions.

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

The pulp-cut beets are carried by the conveying apparatus to the diffuser 114. 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 substances to pass through, 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 high purity juice. It also reduces the filtration problems caused by polysaccharides and proteins that include high molecular weight substances. The solid material 122 that remains after diffusion is passed to a press apparatus 126, in which additional juice is obtained which can be recycled to the diffuser 114. The solids remaining after pressing have a high fiber content and can be used as cattle feed .

The rest of the processes illustrated in Figures 5 and 6 are the same as those described in connection with Figures 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 process is conventional and well known to those of ordinary skill in the art, such as beet and evaporator washing machines. 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). The 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, Inc. (Minneton, Minnesota, USA), PCI (UK) and SCT (France). Suitable ion exchange equipment and resins are available from Prosep (Roscoe, Illinois, USA), IWT (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 and / or carbonation in the process, but it is currently preferred to operate the process without contacting the inlet juice or filtrates with lime or carbon dioxide to effect carbonation. Lime or carbon dioxide can be added as bases.

Example 1

Finishing of extruded juice

The macerated beet slurry was mixed with water and pressed in fabric bags to form a squeezed juice sample. This sample was treated with sodium hydroxide, heated and used in a number of ultrafiltration experiments. Two different spiral ultrafiltration membranes were used in the experiment, type NTR 7410 from Hydranautics and type HFK 131 from Koch. The experiments gave satisfactory flow rates, higher than in the comparative experiments with conventional diffuse beet juice.

• • «· · * * * * * * * * * * * * * *

Table 2: Ultrafiltration of extruded juice - experiment parameters and flows

Experiment no. Pretreatment Type membranes Experiment conditions Experiment results Temperature ° C (° F) Pressure kPa (PSIG) Yield (%) Flow lmh 1 NaOH - heat Spiral 66 (150) 483 (69) 86 30 2 NaOH - heat Spiral 66 (150) 483 (69) 86 25

There was a significant 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 diffuse beet juice.

Table 3: Ultrafiltration of extruded juice - separation parameters

Try C. Howling -žek (%) RDS (%) Sucrose (% RDS) Coloring spraying residue filtrate spraying residue filtrate spraying residue filtrate 1 86 8.9 10.0 7.7 85.8 78.4 91.1 67 256 158 785 925 2 86 8.9 10.0 7.8 85.8 78.4 90.6 67 256 158 785 1138

Example 2

An experiment was performed with beet maceration using Bauer's atmospheric disk refining apparatus. This machine has two 30 cm (12) adjustable gap discs, one stationary disc and another 45 kW (60 hp) drive. In the experiment there were «· · · • · * * * * * * * * * * * * * * * * · · · · · · · · ··· used about 20 kg of beet. Beet was chopped into 1.9 cm (3/4) pieces to make it suitable for the screw feeder.

All cuttings passed through the machine in one pass. Water was used to push the material through the machine, which led to the juice being diluted. A portion of the macerated product was compressed 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 a 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 to 0.25 mm (10 miles) during this pass. The macerated slurry was compressed in a 20 psi membrane press for 15 minutes.

Table 5

Material Concentration in Juice from a 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 slurry dewatered under vacuum 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 had dissolved and were easily washed out. The washed slurry 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 screen, 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 (around 3 kWh / t).

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

3. The vacuum filter cake (after washing) had a low residual sugar content (about 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 extruded juice (99%).

7. The ultrafiltration filtrate from the extruded juice had good sugar parameters.

Example 3

For 30 minutes, 1361 kg (3000 lb) of beet was macerated in solid hammer mills, generating 1514 liters (400 gallons) of juice. Maceration consisted of two passages. 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% RDS. The juice was filtered through a No. 200 mesh vibrating screen. There was no visible residue on the sieve.

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 an 80 mil span insert. 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 parameters and flows and separation parameters

Time (min) yield (%) Tepl, ° C (° F) flow (lmh) RDS (%) Sucrose (%) Coloring The rest. Filt. Vyř. The rest. Filt. Vyř. The rest. Filt. Vyř. (%) 0 0 80 (176) 135 4.6 4.3 6.5 78.7 80.6 4.3 76 946 6781 91.8 35 33 72 (161) 90 5.3 4.4 17.0 70.8 81.2 4.8 130 128 6313 96.0 50 50 74 (165) 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

The rest. means a filter residue, Filt. means filtrate and rec. means discarded.

Note: This test was performed to evaluate the ability to process worse beets. The input material used for this test had a substantially 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 a 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 was centrifuged for two minutes and the extracted juice collected. The cake was mixed again with the same volume of water and centrifuged again. This procedure was repeated six times. At the end of each centrifugation, extracted juice and cake samples were taken. The results of one experiment are summarized in Table 7.

The results show that the sucrose content of juice and slurry was reduced by half at each step. This can be expected because the cake was mixed with the same 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 beet.

• · • ··· ····

Table 7 Results of leaching experiment

Measurement # Juice Porridge 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 1.1 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. In the assay, a ESPA-type reverse osmosis spiral membrane from Hydranautics was used and the osmosis was conducted at 800 psi and 38 ° C (100 ° F). The flow and separation parameters recorded for this test are shown in Table 8.

Reverse osmosis of extracted juice flow and elimination parameters

Obtained (%) Flow (lmh) RDS (%) Sucrose (% RDS) The rest. Filt. Zam. The rest. Filt. Zam. Injection 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 beet (pulp) was fed to a disintegration at 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 to a first Mercone centrifuge manufactured by Dorr-Oliver, which was 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 has centrifuged the fibers and ensured that the remaining beet fibers contained 5.7% sugar and 88% water. The juice was recycled from the second centrifuge and passed countercurrently through the sieve system to the first centrifuge at 11-19 rpm (3-5 gallons / min). About 250 mg / kg (ppm) of antifoam beet (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, the pH was adjusted 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 the first ultrafiltration. It was a 3.7 m (12 ') membrane PCI module with tubular elements separating 200,000 daltons and a 2.7 m ² surface area. The inlet pressure was, on average, 689 kPa (100 psi), the outlet pressure was 434 kPa (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 icu, and the conductometric ash was 4.9%. The filter residue had 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 to 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% sulphated ash). The filtration 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 membrane was 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 input and output currents was according to Table 9.

Table 9

Ca Mg TO On Cl P0 ₄ S0 ₄ Oxalate Injection 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 area was 18 m ² and the inlet pressure was 450 psi and 65 ° C. A stream of 2.6 L / min was injected and the filtrate flow was 1.0 L / min. 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 Rafinosis Betaine Injection 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 nanofiltration product stream was evaporated to give a syrup with 70.5 Brix. Approximately 1 ml / min of ammonium bisulfite solution (ABS) 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 a plate and a frame and was operated at an absolute pressure of 8 psia and the syrup temperature was 85 ° C. A stream of 1 L / min at 25.4 brix was injected.

The evaporator liquid 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 0.6 m (2 ') large, perforated basket. The mother syrup (separated by centrifugation) had an apparent purity of 81.8% and a coloring of 2988 icu.

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 · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 4 · ··· · · ··· used to process 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 color). 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, an RDS of 8.9, a purity of 85.1, and a color of 1959. The inlet and outlet mixtures were as follows (% by dry weight):

Table 11

Ca Mg TO On Ash Resin inlet 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 potassium ion exchange resin product of Example 7 was treated by nanofiltration (operated as in Example 6e above). The product (filter residue) had an RDS 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 the AE506sb type, and the cationic membrane was of the CMXsb type. The series was operated at 45-55 ° C, a voltage of 18-30V and a current intensity of 2-3A. The anolyte and catholyte systems contained diluted amidosulfonic acid (conductivity 20 mS / cm), which circulated through the line at 3 g / m (111 / m). min). The treated stream was circulated at 8 to 10 g / m (30 to 38 l / min) and flowed through the entire system at 1 l / min. The concentrating 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% of ions on dry weight basis).

• A A • 9

Table 12

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

Example 9

The juice from the beet maceration system described in Example 6a was filtered in a spiral ultrafiltration membrane. First, 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 separating the 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 3.61 / min and the filtrate and filter residue flow was 1.8 l / min at both RDS 13 and 14.2, giving a flow rate of 22.5 l / m ² .h at a concentration factor of 2. Coloring the feed rate was 1232 icu and the color of the filtrate 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 mother liquor mixture from white sugar crystallization and the filter residue from the second ultrafiltration was evaporated to 60 RDS 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. Typical properties of each of these fractions are shown in Table 13 below.

Table 13

Flow 1 / hour RDS Sucrose Invert Ash Rafinosis Organic phase Coloring Injection 0.9 60 66.6 4.0 5.9 8.2 15.3 33 000 Organic fractions 0.7 1.1 13.2 9.8 16 0.0 61 29 700 Sucrose fractions 1.84 29.3 96.0 0.7 0.2 3.1 o, o 6090 Rafinózová fractions 2.5 8.4 13.7 9.8 16.6 20.4 39.5 90 300

The sucrose fraction obtained can have a purity of 96% and mean obtaining 92.5% of the input sucrose

Example 11

450 g of the first white sugar crystallization syrup (with 75 RDS, and containing 2.3% raffinose as dry matter) was diluted to 30 RDS with water. The pH was adjusted to 5.0 y

by addition of dilute sulfuric acid and the solution temperature was brought to 50 ° C. 2.5 x 10 units of α-galactosidase enzyme pellets (12.2 g) were added and the solution was stirred at 50 ° C for 2 h. The resulting juice contained 0.7% raffinose solids.

»9« · · · · ·

9 * • 9 «999 999 r 9 9

Example 12

The mother liquor from the first batch of white sugar crystallization (3147 icu color at 83.1% apparent purity) was crystallized under vacuum to give a second batch of 20 icu white sugar and a 0.01% asymmetrical ash conductivity. 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 formed by crystallization was centrifuged on a 0.6 m (2 ') basket centrifuge using a perforated basket. The mother syrup (separated by centrifugation) had an apparent purity of 81.1% and a coloring of 4155 icu.

Example 13a

Beet juice from the factory diffuser (4200 icu color) was fed to a 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 pH adjusted 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 conducted at 73 ° C for the first ultrafiltration in an Osmonics PW with a 10 cm diameter 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 transverse 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 the 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) membrane * spiral modules.

ν · ·· «·

Osmonics GK and two types of Osmonics GE. These membranes have molecular weight cuts 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.

Example 13c

The filtrate from the second ultrafiltration membrane system was processed by nanofiltration with 2 Degrees 10 cm (2) Desal DS5 membranes. The total membrane surface was 12 m ² , the inlet pressure was 4503 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 ic color and a conductivity ash of 4.2%. The filtrate had an RDS of 5.2 and an apparent purity of 38.3.

Example 13d

The nanofiltration residue of Example 13c was filtered 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 2-3 A. / 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 the product was as follows:

- zcTable 14

% ash Ca Mg TO On Cl PO4 SO ₄ oxalates Input 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 0,046 0,061 0,073 1,2

The product had a purity of 92.5% (by HPLC)

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 (color 3060 icu). The evaporator was a single acting APV plate and frame unit and was operated at a pressure of 55 kPa abs. (8 psia) and the syrup temperature was 85 ° C. The evaporator feed was 1 liter / min at 24 Bx.

The evaporated syrup crystallized under vacuum to give a white sugar of 17.3 ic color and a conductivity ash of 0.007%. Crystallization was carried out in a batch mode in a crystal 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 0.6m (2 ') perforated basket centrifuge.

Example 13f

The mother syrup produced by the methods of Example 13e was further crystallized in a Pignat crystal at 20 kPa absolute. and 70-75 ° C for 3 hours. The confection was centrifuged on a 0.6 m (2 ') basket centrifuge to give a second sugar having a 40 ic color and an ash of 0.019.

Example 14a

An amount of 208 liters (55 gallons) of fresh beet juice from a divider at 16.5 Brix and a coloring of 3850 icu was adjusted to pH 8 with sodium hydroxide solution. 2.2 liters of 3% (v / v) hydrogen peroxide (0.03% for juice or 0.19% for solids) were added. The juice was heated to 80 ° C for 60 min, during which the coloration increased to 14,000 icu. Ultrafiltration through a PCI tubular membrane cut at 4000 daltons operating at 300 psi 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 confection having a color of 4450 icu was obtained. Spin and wash gave crystals with an o

-2f · · · icu. 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 confection.

Example 14b

The work of Example 14a was repeated, but the beet diffuser juice was sprayed on the oxidation, which was heated and aerated as described in Example 13a. 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 of white sugar crystallization 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 5.8 L resins distributed over ten cells. Water can be injected 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. Typical properties of each of these fractions are shown in Table 15 below. (Organic matter represents the amount of material calculated from the difference with the analytical results.

Table 15

Flow 1 / h RDS sucrose Inverse Ash Rafinosis Organic substances Coloring icu Injection 1.0 60 67.5 5.0 6.2 7.4 17.3 37 000 Organic fractions 0.7 1.0 12 11.1 18.2 0.0 58 31 200 Sucrose fractions 1.9 27.9 96.5 1.0 0.4 2.5 0.0 6900 Rafinózová fractions 2.6 9.1 15.1 8.7 19.2 22.3 42.5 85 700

..X

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 RDS 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 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 solid substances.

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 give a second batch of white sugar with 28 icu color 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 formed in the crystallization was centrifuged on a 2 " 2 " basket basket centrifuge using a perforated basket. The mother syrup (separated by centrifuge) had an apparent purity of 77.4% and a coloring of 5807 icu.

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

Claims (73)

CLAIMS 1. A method for producing sugar from beet comprising the steps of (a) either (1) maceration of beet or cuts thereof; or (2) cutting of beet into cuttings; (b) separating juice from macerated beet or cuttings; 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 juice from macerated beet; and (c) membrane filtration of the separated juice to produce a filter residue and filtrate. Method according to claim 2, characterized in that the beet is cut into pieces and then macerated. Method according to claim 3, characterized in that the maceration is carried out in a disc mill. Method according to claim 2, characterized in that the mechanical separation of the juice is carried out on a moving porous vacuum filter belt with a countercurrent flow of macerated beet and water. Method according to claim 2, characterized in that the mechanical separation is carried out by 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 vacuum-separated juice is adjusted to at least 7 by the addition of sodium hydroxide. 9 · The method of claim 7, wherein the separated juice is contacted with an agent selected from the group consisting of sulfur dioxide, sulfate salts, sulfite salts, bisulfite salts and mixtures thereof in an amount sufficient to adjust the pH of the extracted juice to at least 7. Method according to claim 2, characterized in that the membrane filtration is performed with an ultrafiltration membrane. Method according to claim 2, characterized in that the membrane filtration is carried out with a nanofiltration membrane. The method of claim 10, wherein the membrane filtration is cross-flow ultrafiltration and is performed at at least 80 ° C and the pH of the filtrate is at least 7. 13. The process of claim 2, wherein the membrane filtration residue is diafiltrated to obtain residual sugar in the filtration residue. Process according to claim 13, characterized in that the diafiltration filtrate is combined with the membrane filtration filtrate for further processing. 15. The method of claim 2, wherein the membrane filtration filtrate is concentrated by reverse osmosis to form a concentrated solution. 16. The process according to claim 15, wherein 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. • · · · · · · · · · · · 18. A method for producing sugar from beet comprising the steps of: (a) cutting sugar beet into pieces, (b) maceration of beet pieces, (c) mechanical extraction of juice from macerated beet, d) membrane filtration of extracted juice and formation of 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 sucrose therefrom. 19. A method for producing sugar from beet comprising the steps of: (a) macerating sugar beet or pieces thereof to produce macerated material which includes slurry and liquid; b) separating the liquid in the macerated material from the slurry and forming sucrose containing inlet juices, c) filtering the sucrose-containing inlet juices through a first ultrafiltration membrane having a first molecular weight cut and forming an ultrafiltration filtrate and a first ultrafiltration residue, d) filtering the first ultrafiltration filtrate through a second ultrafiltration membrane having a cut at a second molecular weight that is less than cut at a first molecular weight and forming 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: (a) cutting sugar beet into pulp and obtaining sucrose-containing juice by diffusion therefrom; b) filtering the sucrose-containing feed juice through a first ultrafiltration membrane that performs cutting at a first molecular weight and producing a first ultrafiltration filtrate and a first ultrafiltration residue, (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 to form 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. 23. The method of claim 22, wherein the electrodialysed juice is softened by ion exchange and a softened purified juice is formed. 24. The method of claim 23, wherein at least 65% by weight of Ca, Mg, K, Na and the inorganic and organic anions present in the second ultrafiltration filtrate 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. // & A 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 6-8 by adding a base before the first ultrafiltration. 28. The method of claim 19, wherein, after separation of the liquid, no more than 5% of the sucrose present in the beet remains in the slurry. 29. The method of claim 28, wherein, after separation of the liquid, no more than 3% of the sucrose present in the beet remains in the slurry. 30. The method of 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 the screening and filtration prior to the first ultrafiltration. A method according to claim 30, characterized in that at least 90% by weight of all fibers and sludge having a largest dimension of at least 150 µm are removed by sieving or filtration. Process according to claim 31, characterized in that at least 90% by weight of all fibers and sludge having a maximum dimension of at least 50 µm are removed by sieving or filtration. 33. The method of claim 19, wherein the beet is macerated by passing through a hammer mill and converted into a mixture of slurry and a sucrose-containing liquid. 34. The method of claim 33, wherein the macerated beet is also passed through a crusher. <· • · 35. The method of claim 33, wherein the liquid is separated from the slurry by centrifugation. The method of claims 19 or 20, wherein the first ultrafiltration residue is diafiltered through at least the first diafiltration or ultrafiltration membrane and the first diafiltration filtrate and the first diafiltration residue and the first diafiltration residue are produced 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. 38. The method of claim 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 a first diafiltration residue, a second diafiltration residue, and a nanofiltration filtrate are combined to produce molasses. 40. The method of claim 19 or 20, further comprising vaporizing the nanofiltration residue to produce concentrated syrup and crystallizing white sugar from the concentrated syrup. 41. The method of claim 23, further comprising vaporizing the clarified juice and producing a concentrated syrup and crystallizing the 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 dry matter. · · · · · · · · · · · · · «·« · «A * * 43. The method of claim 42, wherein the clarified juice has an ash concentration of at most 2.0% by weight based on dry matter. 44. The method of claim 41, wherein the clarified juice has an ash concentration of at most 1.0% by weight on a dry matter basis. 45. The method of claim 41, wherein the method comprises two crystallizations of white sugar from concentrated syrup. 46. The process of claim 40, wherein the mother liquor remains after crystallization of the white sugar from the concentrated syrup and is recycled to one of the ultrafiltration membranes. 47. The method of claim 41, wherein the mother liquor remains after crystallization of the white sugar from the concentrated syrup and is recycled to one of the ultrafiltration membranes. A method according to claims 19 or 20, wherein during filtration through the first ultrafiltration membrane the inlet juice is at a temperature of 60 to 93 ° C. 49. The method of claim 48, wherein the inlet juice has a temperature of 71-85 [deg.] C. during filtration through the first ultrafiltration membrane. 50. The method of claim 19 or 20, wherein the first ultrafiltration membrane cuts to a molecular weight value of at least 2000 daltons and a pore size of at most 0.1 µm. 51. The method of claim 50, wherein the first ultrafiltration membrane cuts to a molecular weight of 4000 to 200,000 daltons. The method according to claims 19 or 20, wherein the first ultrafiltration filtrate has a coloration of 3000 to 10,000 icu. • · · · · · · · 53. The method of claims 19 or 20, wherein the second ultrafiltration membrane cuts to a molecular weight of 500 to 5000 daltons. 54. The method of claim 53, wherein the second ultrafiltration membrane cuts to a molecular weight value of 1000 to 4000 daltons. The method of claims 19 or 20, wherein the second 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. 57. A method according to claim 19 or 20, wherein the nanofiltration filtrate comprises at least 30% by weight, based on dry matter, 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 matter, 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 matter, of betaine present in the inlet juice. 60. The method of claim 19 or 20 wherein at least one of the water streams selected from the group consisting of inlet juice, first ultrafiltration filtrate, second ultrafiltration filtrate, and nanofiltration residue is contacted with an agent selected from the group consisting of: sulfur dioxide, sulphite salts, bisulphite salts, metabisulphite salts, dithionite salts and mixtures thereof in an amount sufficient to ensure an equivalent sulfur dioxide concentration in the stream of at least 100 mg / kg. · · · R r r r r r r r r r r · · r »» »» »» » Λ o · · · · · · · · · · * * * Jks 61. The method of claim 23 wherein at least one of the water streams selected from the group consisting of inlet juice, first ultrafiltration filtrate, second ultrafiltration filtrate, nanofiltration residue, and clarified juice is contacted with an agent selected from the group consisting of: from sulfur dioxide, sulphite salts, bisulphite salts, bisulphite salts, dithionite salts and mixtures thereof in an amount sufficient to ensure 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 claim 19 or 20, further comprising the step of scavenging enough air into the inlet juice and 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 60-93 ° C prior to filtration through the first ultrafiltration membrane. 65. A method for producing sugar from beet comprising the steps of (a) macerating 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 that cuts a molecular weight 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, d) filtering the first ultrafiltration filtrate through a second ultrafiltration membrane which cuts 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 uitrafiltration residue, e) filtering the second ultrafiltration filtrate through the nanofiltration membrane and manufacturing H V ··· ·· · * <<· < 4 of 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), f) cleaning 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 the water from the evaporator feed to produce a concentrated syrup; and h) crystallizing white sugar from concentrated syrup. 66. A method for producing sugar from sugar beets, comprising the steps of (a) cutting sugar beet into pulp and obtaining sucrose-containing inlet juice by diffusion; (b) filtering sucrose-containing inlet juices through a first ultrafiltration membrane that cuts 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 to a molecular weight of 2000 to 4000 daltons and produces a second ultrafiltration filtrate having a coloration of at most 4000 icu 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 dry matter-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. 67. The method of claim 65 or claim 66, wherein the method comprises at least two crystallizations of white sugar from concentrated syrup. 68. The method of claim 65 or claim 66, wherein the mother liquor produced in crystallization comprises raffinose and at least 75% by weight of raffinose is removed from the mother liquor in a chromatographic separator simulated to: to a moving bed and reclaimed mother liquor is recycled . 69. The method 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. a second ultrafiltration membrane. 71. A method of purifying sucrose containing juice obtained from sugar beet, comprising the steps of: (a) injecting air into the juice sufficient to cause the polymerisation of colored particles; and b) removing at least some colored particles from the juice by membrane filtration through at least one ultrafiltration membrane or nanofiltration membrane. 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 lower 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.