K-Patents Applications in Sugar and Sweeteners Industry

1.01.00 Beet Sugar Process

1.01.01 Extraction
1.01.02 Evaporation
1.01.03 Crystallization
1.01.04 Crystallization Comparison
1.01.05 Green Syrup and Molasses
1.01.06 Desugarization of Molasses by Chromatographic Separation

1.02.00 Cane Sugar Process

1.02.01 Affination
1.02.02 Decolorization
1.02.03 Evaporation
1.02.04 Crystallization
1.02.05 Recovery

1.03.00 Starch Sweeteners Process

1.03.01 Ion-exchanger
1.03.02 Evaporator
1.03.03 Crystallizer
1.03.04 Chromatographic Separation
1.03.05 Carbon Column1.04.00 Citric Acid Process

 

1.01.00 Beet Sugar Process
Overview of Process Control
Ref. 1.01.00 Beet Sugar Process (pdf) 

1.01.01 Extraction
After the beets are thoroughly washed, they are passed through the slicers, where they are cut into long, thin strips or cossettes. The cossettes, upon entering the continuous diffuser, are elevated by means of a perforated flight scroll or a similar device. Counter-current water is introduced at the upper end of the diffuser. The diffuser is steam-heated by means of external jackets. The extracted sugar leaves the diffuser at a concentration of 10 to 15% Brix, which accounts for about 98% extraction of the beets.
Ref. 1.01.01 Extraction (pdf)

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1.01.02 Evaporation
The evaporator station forms an important link between the juice production and crystallization parts of the sugar production plant. Usually, the evaporator station comprises 4 to 5 evaporator stages, of which the first ones consist of multiple evaporators. As the pressure in the evaporators is regulated, so that it decreases from stage to stage, the juice passes sequentially through all the stages. Once the required concentration is reached, the “thick juice” is discharged from the last stage of the evaporator station. A general requirement is that the concentration of thick juice in the evaporator outlet should be as high as possible, reaching 68-75% dry substances in most advanced factories. It is then possible to apply crystallization technologies, which ensure a high sugar quality while also facilitating low energy consumption.
Ref. 1.01.02 Evaporation (pdf) 

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1.01.03 Crystallization
The crystallization process takes place in vacuum pans, which boil the thick juice. When the juice reaches the correct concentration, it is “seeded” with sugar crystals, which provide the nucleus for larger crystals to grow. When the crystals reach the required size, the process is stopped and the resultant mixture of crystal sugar and syrup – known as massecuite – is spun in centrifuges to separate the sugar from the mother liquor. The sugar crystals are washed and, after drying and cooling, are conveyed to storage silos.

Ref. 1.01.03 Crystallization (pdf)

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1.01.04 Crystallization Comparison: Crystallization has a major effect on product quality and production costs. Supersaturation is the driving force of crystallization and crystal growth. The speed of crystallization depends on this parameter. Excessive superaturation results in poor crystal quality (fines and conglomerates). The crystals are melted, concentrated, re-circulated and crystallized again. This leads to a waste of time and energy, decreased yield of sugar per strike, increased water usage and increased production costs. A selective measurement of the liquid phase is required for successful control of the supersaturation.
Ref. 1.01.04 Crystallization Comparison (pdf)

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1.01.05 Green Syrup and Molasses: Molasses is a viscous by-product of the beet sugar process. The syrup left from the final crystallization stage is called molasses and intermediate syrup is referred to as green syrup. It is recycled within the crystallization plant to maximize extraction.
Ref. 1.01.05 Green Syrup and Molasses (pdf)

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1.01.06 Desugarization of Molasses by Chromatographic Separation: Molasses desugarization by ion-exclusion and chromatographic separation is a process for extracting sugar from molasses. Another method is betaine separation from beet molasses, using chromatographic separation and having at least three chromatographic columns connected in series. Betaine is used in the pharmaceutical, cosmetic, feed, food and chemical industries. Diluted molasses is supplied to a chromatographic water feed column. Different fractions leave the bottom of the column. First, a non-sugar waste fraction, a second fraction containing a substantial proportion of the sugars in the feed and a third fraction of betaine, which is eluted at the tail end after the sugar fraction. The third fraction contains a high proportion of the betaine in the feed, as much as 80% or more, on dry substance. From this betaine fraction, betaine can be recovered by crystallization or may be recovered as hydrochloride, if desired. Use of these processes has enabled a 95% recovery of the sugar in molasses.
Ref. 1.01.06 Desugarization of Molasses by Chromatographic Separation (pdf)

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1.02.00 Cane Sugar Process: Overview of process control
Ref. 1.02.00 Cane Sugar Process (pdf)

1.02.01 Affination: The first step in refining, where the raw sugar crystals are treated with heavy syrup (typically 60 to 80 Brix) in order to remove the film of adhering molasses, is called affination. The syrup is used as a washing solution for the sugar crystals.
Ref. 1.02.01 Affination (pdf)

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1.02.02 Decolorization: The decolorization process removes organic impurities, which impart color to the sugar liquor. These impurities and colorants are removed with ion-exchange columns.
Ref. 1.02.02 Decolorization (pdf)

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1.02.03 Evaporation: The thin juice (light colored syrup) is heated and pumped in to the multiple stage evaporators. The dissolved solids concentration is raised from an initial concentration of 10-15 Brix to 50-65 Brix. The concentrated solution is known as "thick juice".
Ref. 1.02.03 Evaporation (pdf)

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1.02.04 Crystallization: The final stage in a cane sugar mill is transforming the concentrated syrup into crystals by using vacuum boiling pans. To manage this liquid-solid transformation process energy efficiently, it should be performed in stages. The final stage of the crystallization process is the C or D –pan, where saccharose can be extracted from the massecuite solution. The efficiency and control of this extraction is the priority. Crystallization is initiated by seeding the concentrated liquor with very fine crystals. The process is continued until the crystals reach the specified size. The resultant mixture of crystals and mother liquor is fed in centrifugal separators and the sugar crystals are washed with hot water to remove any adhering syrup.
Ref. 1.02.04 Crystallization (pdf)

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1.02.05 Recovery: Cane sugar crystallization produces a residual, which still contains a lot of soluble sucrose. The objective for the manufacturer is to improve its recovery. Crystallization is carried out in vacuum boiling pans under carefully regulated conditions. The white sugar crystals are separated in centrifuges. The sugar from the centrifuges is dried in drum dryers and the syrup is collected for the next boiling. The first non-acceptable sugar is circulated back to the affinated sugar to be dissolved and the final syrup from the white sugar boiling is directed to the recovery process.
Ref. 1.02.05 Recovery (pdf)

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1.03.00 Starch Sweeteners Process: Overview of process control
Ref. 1.03.00 Starch Sweeteners Process (pdf)

1.03.01 Ion-exchanger: Ion-exchangers are used to remove all salts from the syrups. The decolorized syrups are treated with an ion-exchange to remove the ionic contents that increased, when chemicals such as acids, bases and calcium were added during the process. Six-bed ion-exchangers are the most common ones. They have three beds of cation and three beds of anion columns. One bed is always at the regenerational phase. The resin is usually regenerated with Hydrochloric acid (HCl) and diluted with Caustic soda (NaOH). Before the generation is allowed to take place, the columns must be rinsed with water to remove any sugar residue. This is often referred to as “sweetening off”.
Ref. 1.03.01 Ion-exchanger (pdf)

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1.03.02 Evaporator: Falling film evaporators, with two or more effects, are frequently used by the liquid sweeteners industry. The evaporators with up to seven effects have been employed since the mid-seventies to offset rising energy costs. Evaporators are used to remove excess water from syrups and to raise the concentration to a predetermined level. There are generally four variables involved in the equation used for evaporation control: inlet concentration, outlet concentration, steam flow and product flow. For the maximum efficiency and minimum steam consumption, all these variables must be coordinated.
Ref. 1.03.02 Evaporator (pdf)

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1.03.03 Crystallizer: Cooling crystallizers are mainly used for the dextrose and fructose syrups crystallization. The saturated syrup reaches supersaturation as the temperature slowly decreases. At this stage, the crystals start to form and grow. As the crystals grow bigger, the concentration of the mother liquid decreases. Fresh syrup must be fed into the crystallizer in order to maintain the supersaturation.
Ref. 1.03.03 Crystallizer (pdf)

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1.03.04 Chromatographic Separation: Fructose and glucose separation can be done with column-chromatographic technology. First, the high fructose syrup (HFS) is fed to the fixed-bed separation columns filled with special absorbents, which absorb the fructose and glucose to differing degrees. The glucose is the product, which leaves the columns first and can thus be separated from the fructose fraction.
Ref. 1.03.04 Chromatographic Separation (pdf)

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1.03.05 Carbon Column: Carbon columns are used for the elimination of syrup impurities. Hot water is pumped into these columns for the “sweetening off” process. Initially, the fine liquor is discharged. After the hot water starts to break through the carbon bed, the discharge is directed to the sweet water line. When the concentration drops to 0.5%, the column is ready for carbon transfer.
Ref. 1.03.05 Carbon Column (pdf)

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1.04.00 Citric Acid Process: Overview of process control
Ref. 1.04.00 Citric Acid Process (pdf)

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