656025175-Sugar-Industries-PPdggfT-1.pptx

dfhfjhgkjyu

1. The Process Technology of Sugar Industries

2. Introduction Sugar serve as the principal foodstuffs for humans and have considerable promise as major chemical raw materials for different industry. It supplies sweet taste and energy. Since the major source of sweetener are sugar cane, sugar beet and corn dextrose. As the result ,sugar production and refining is a huge industry.

3. Raw materials Sugarcane is a grass grown in tropical and sub- tropical countries. It is propagated vegetative by planting pieces of cane stalk. New growth emanates from buds on the cane nodes ensuring uniform progeny. sugar beet is also starch material for sugar production which grow well in temperate zones. Both of them have high content of sucrose . Other sources of sugar are a certain palm tree and honey but low yield. For food stuff and sweetness is also corn is the major one.

4. Main raw materials

5. Sugar cane Composition Component Per cent/ % Water ------------------------------70-75 Sucrose ----------------------------10-17 Reduced sugars ------------------ 0.4-2 Organic non-sugar-------------- 0.5-1 Mineral matters -------------------0.5-1 Fiber-------------------------------10-16 0.25 to 0. 3 tones of wet bagasse per ton of sugar cane is produced.

6. SUGAR CANE, PRODUCTS AND ITS BY-PRODUCTS

7. Sugar canes are weighed and washed before they are juiced. Then they are sent through crushers and then into the mill. The juice is collected and it is clarified to remove mud and separate any material found different from sucrose. This is then followed by an evaporation process to prepare the syrup. Once it is in syrup form it is crystallized to separate out the liquor, and centrifuged to separate molasses from the crystals.

8. PRODUCTS AND ITS BY-PRODUCTS

9. Sugars or Saccharides are synthesized/formed in the agricultural field in plants. The sugars are formed or synthesized during the growth of the sugar cane plants taking carbon dioxide from atmosphere and water from the soil by photosynthesis as per the following two steps reactions. 6CO 2 + 6 H 2 O + solar Energy → C 6 H 12 O 6 + 6O 2 2 C 6 H 12 O 6 → C 12 H 22 O 11 + H 2 O (Sucrose/sugar cane juice Cane yield: Ton or quintals of cane per hectare Sucrose yield : Quantity of Sucrose per hectare High cane yield saves cultivation, harvesting and transportation costs because of smaller hectarage required. High sucrose yield reduces plantation and processing costs

10. The carbohydrates in sugar are called disaccharides. Disaccharides are groups or compounds that have a link together between carbon in one sugar and a hydroxyl group from any position on the other sugars

11. Main processing technology of sugar industries Extraction Separation of the sugared juice from the bagasse/fiber Clarification Separation of non desirable or impurites substances from juice Evaporation Separation of 80% of the water Crystallization Separation of sucrose from different classes of molasses Centrifugation Separation of sugar crystals Energy production: Steam and Power Generation

12. Sugar industris

13. Pictorial flow diagram

14. 1. Cane Yard 2. Cane preparation : knives & Shredders 3. Juice extraction : mills and diffuser 4. Juice clarification: Heaters, lime slaker , sulpher burner, defecator, sulphitation vessel, flash tank , Dorr-clarifier & filters 5. Evaporation : Evaporators 6. Syrup sulphitation : Sulphitation vessel 7. Vacuum pan operation /crystallization : Evaporation & Crystallization 8. Sugar Separation : Centrifuge 10.Sugar grading ; agging Machine 12.Material handling units : Cane Carriers, Pumps, Bucket elevators 13.Boiler, Turbines and Electrical generators Next start Major unit operations of sugar process technology

15. Process Flow diagram of sugar producing factories .

16. 1. Cane Yard 2. Cane preparation Cane preparation generally contains the following main operation  Washing : removal of soils coming from mechanical harvesting  Disintegration: exposition of juice containing tissue of the cane stalk  Iron removal: iron components coming mechanics harvesting knives Shredders Cane washing

17. Cane weighing and washing plant Before going to the unloading platform, all the transporters cross the factory weighbridge.  The exact weight of cane coming to the mill must be known. This is important for the following reasons: Payment to farmers and planters for the sugar produced from their cane.  Chemical control and determination of factory performances . Large amounts of trash, mud, sand and stones are transported together with the cane. These are removed in cleaning plants. The cleaners may be of wet or dry type. In the wet cleaner, the cane is washed through showers in a mud trough where powerful water jets float the cane, while the rock and mud collect at the bottom and are carried away. The trash is also removed by special extractors, using large quantities of high velocity air.

18. The cane is prepared by the help of sets of cane knives to open the juice cells in the cane for extraction of juice. The prepared cane is passed through three/four mills with water imbibition at the last mills. The juice is collected from all the mills. It is then filtered through screen to remove the fiber particles in it before sending for processing. The mills and the cane preparation units are driven by electric motors/steam turbine Preparation of the cane has three main objectives .   To increase capacity by increase of bulk density of the feed. To assist extraction at the mills by breaking down the structure of the cane .   To render the juice more readily available for the action of imbibition by breaking and opening cane cells

19. 3. Juice extraction : mills and diffuser A set of mills Diffuser Feed roller Top roller Discharge Roller Bagasse Cane Juice

20. Milling is the process by which pressure is applied to the prepared cane to extra as much juice as possible from it. The cane is made to pass through a succession of rollers that comprises the milling tandem, and its juice is squeezed out as it goes through. To help to extract the maximum juice, use of imbibition water is made. The extracted juice is sent to process and the fibrous material left after milling, known as final bagasse , is sent to the boilers to be used as fuel for the generation of steam.

21. Straight mill tandem extraction process

22. Mixed juice (MJ) is the desirable main product of the unit operation or the extraction plant and can be determine by simple material balance with out considering the extraction losses. C + I = MJ + B MJ = C+ I – B The composition of mixed juice depends on various factors such as cane variety, cane age, water condition (rain fed and/or irrigation) geographical location and growing conditions as well as on the harvesting and milling processes.

23. Total sugars 75-92% Sucrose 70-88 % Glucose 2-4% Fructose 2-4% Salts 3-4.5% In organics 1.5-5.5% Organics 1.0-3.0% Organic acids 1.5-4.5% Carboxylic acids 1.1-3.0% Other acids 0.5-2.5% Other organic non sugars 0.85-1.45% Proteins 0.5-0.6% Starch 001-0.1% Gums 0.3-0.6% Waxes, fats & phosphate 0.05-0.15% Others 3-5% Composition of the soluble solids of mixed juice

24. 4. Mixed Juice clarification The clarification process needs to remove as much as possible the greater majority of all these non-sugar components other than sucrose and at the same time minimize loss of sucrose and color formation . Removal of impurities (consisting of both soluble and insoluble non-sugar compounds) from mixed juice requires different clarification methods depending on the type of sugar to be produced (Raw Sugar, White Plantation Sugar and Refined Sugar ). To this end, clarification process is expected to bring the following results. Separation of soluble and insoluble non-sugar matter by settling Reduction of color & Turbidity of the juice by chemical and physical action Killing or inactivation of microorganisms in the juice by heat treatment. Production of quality clear juice with correct pH of 7.0, temperature, time and minimum inversion.

25. In Mixed Juice clarification quite a variety of chemicals (milk of lime, sulphur dioxide, carbon dioxide and phosphoric acid ) are added and process parameters ( Temperature, concentration , pH, settling time, and others ) are optimized for higher performance of the unit operations involved in the clarification process. Clarification process set-ups are listed below followed by the flow diagrams of typical clarification process used in raw and plantation white sugar industries .

26. i . Heating ii. Milk of lime preparation iii. Defection/liming iv. Acidification - SO 2 generation and Sulphitation - CO 2 generation and Carbonation - Phosphation v. Flashing vi. Flocculants preparation and application vii. Clarifier duty and equipment viii. Mud slurry Filtration ix. Mud removal system x. Rotary vacuum filter xi. Clarification processes

27. Purpose of heating T o dehydrate the colloidal particles by removing the water film surrounding them. Inactivates and kills microorganisms such as yeast, molds and bacteria that could cause inversion and enhance deterioration of juice . F acilitated the gashing of entrained air and vapor from the mixed juice when it enters the flashing unit Purpose of liming to neutralize the organic acids present in the juice, after which the temperature is raised. The main objective of SO2 addition is: inhibit reactions that cause color formation; to act as a bleaching agent to coagulate soluble solids; to produce CaSO3 (calcium sulfite) precipitate that can absorb colloidal impurities to decrease juice viscosity and consequently , viscosity of the syrup, massecuite , and molasses improving the evaporation and crystallization operations

28. Carbonation can be used instead of sulphitation or with sulphitation to produce refined white sugar . Carbonation is effective in the removal of coloring materials. The advantages of phosphate adding : Greater colloid elimination Fewer lime salts in clarified juice More rapid settling Faster mud filtration Better working conditions of low grade massecuites The disadvantages of phosphate addition: The precipitate tricalcium phosphate is difficult to filter Increased mud volume Higher lime consumption Extra cost

29. The flashing process removes the air gas bubbles attached to the suspended particles of the juice which if not removed would prevent the suspended particles from agglomeration and settling. In general the flash tank simultaneously provides the following three important multiple functions. effective removal of entrained air and vapour from the heated homogenous mixing of flocculant polymer with feed juice building up thick and heavy flocs from loose and fragile initial flocs .

30. For improving settling rate and increasing the clarifier through put the addition of synthetic flocculant is essential. Most suspensions in lime treated juice contain negatively charged particles, therefore, cationic flocculants are expected to be the most suitable. The action of flocculants in juice clarification are : Increases settling rate. Reduce mud volume. Decreases Pol in cake. Increases the clarity of clarified juice.

31. Flash vessel Clarifier equipment Settler zones Rotary vacuum filter

32. Clarification process

33. Evaporation and crystallization Evaporation is performed in two stages : initially in an evaporator station to concentrate the juice and then in vacuum pans to crystallize the sugar. The clarified juice is passed through heat exchangers to preheat the juice and then to the evaporator stations. Evaporator stations consist of a series of evaporators , termed multiple-effect evaporators ; typically a series of five evaporators. Steam from large boilers is used to heat the first evaporator, and the steam from the water evaporated in the first evaporator is used to heat the second evaporator . This heat transfer process continues through the five evaporators and as the temperature decreases (due to heat loss) from evaporator to evaporator, the pressure inside each evaporator also decreases which allows the juice to boil at the lower temperatures in the subsequent evaporator. Some steam is released from the first three evaporators, and this steam is used in various process heaters in the plant. From the clarifier, the syrup goes to the vacuum pans for crystallization.

34. Crystallization of the sugar starts in the vacuum pans , whose function is to produce sugar crystals from the syrup . In the pan boiling process, the syrup is evaporated until it reaches the super saturation stage. At this point, the crystallization process is initiated by “ seeding” or “shocking ” the solution. When the volume of the mixture of liquor and crystals, known as massecuite , reaches the capacity of the pan, the evaporation is allowed to proceed until the final massecuite is formed. At this point, the contents of the vacuum pans (called “ strike ”) are discharged to the crystallizer, whose function is to maximize the sugar crystal removal from the massecuite . From the crystallizer, the massecuite (A massecuite ) is transferred to high-speed centrifugal machines ( centrifugals ), in which the mother liquor (termed “ molasses ”) is centrifuged to the outer shell and the crystals remain in the inner centrifugal basket. The crystals are washed with water and the wash water centrifuged from the crystals.

35. A crystallizer A crystallizer A crystallizer A centrifuge B centrifuge C centrifuge C Vaccum pan A Vacuum pan B Vaccum pan

36. Thank you!!!