Sugar Production Technology ( Dr. Mustafa BAYRAM )
FE 401 FOOD TECHNOLOGY SUGAR PRODUCTION TECHNOLOGY
Prof. Dr. Mustafa BAYRAM University of Gaziantep, Faculty of Engineering Department of Food Engineering 27310-Gaziantep-TÜRKİYE Rev3-Nov 23, 2014
SUGAR • The word sugar comes from the Indian sarkara. • The chemical name of sugar is sucrose in English and saccharose in some European languages. • Sugar (sucrose, C12H22O11) is one of the families of sugars (saccharides). • All sugars belong to a larger group, known as carbohydrates (sugars, starches, and dietary fibers). • The term sugar substitutes refers to all natural and synthetic (artificial) sugars other than sucrose. • All sweettaste sugars and sugar substitutes are known to us as sweeteners.
GENERAL PROCESSING STEPS Harvesting and transporting to the factory Washing and cleaning Extraction of juice Weighing of raw cane juice Liming of cane juice Clarification of cane juice Filtration of mud from clarifiers
Evaporation Massecuite Crystallization by cooling Centrifuging and purifying Shipping bulk sugar
TYPES • 1-Beet • 2-Cane • Other (fruits, additives, corn, syrups etc.)
1-SUGAR BEET • The root serves as a reservoir for the sugar, which can represent between 15% and 21% of the sugar beet’s total weight. Beet sugar (sugar made from sugarbeet), cane sugar (sugar made from sugarcane), and refined sugar (sugar made from raw sugar) are similar in shape, taste, and other chemical and physical properties.
HISTORY OF SUGAR BEET • Sugar beet was first grown at least 2000 years ago as a garden vegetable. • The vegetable was probably selected from various Beta species growing round the shores of the Mediterranean. • It was widely used for culinary purposes throughout Europe from the Middle Ages onwards. • Beet was grown on a field scale first in the seventeenth century but only as fodder for cattle.
GROWING AREAS OF SUGAR BEETS • Sugarbeet (simply beet) grows in moderately cold climates but can adapt itself to very cold and warmer climates as well. In Europe, it grows almost everywhere, from the southern temperate country of Turkey to the northern cold countries of Sweden, Denmark, and Finland. • In Asia, sugarbeet is grown in Iran, Israel, Lebanon, China, Korea, Japan, the northern part of Pakistan, and a few other countries. In Africa, the northern part of Morocco and Egypt grow sugarbeet.
PROPERTIES • The root of the beet (taproot) contains 75% water and 25% dry matter. The dry matter comprises about 5% pulp. • Pulp, insoluble in water and mainly composed of cellulose, hemicellulose, lignin and pectin, is used in animal feed. Sugar represents 75% of the root’s dry matter.
VA R I E T I E S O F S U G A R B E E T S
PROCESSING OF SUGAR BEET Reception Storage Dry cleaning Conveying and flumming Flume water treatment Stone and trash separation Beet slicing Juice diffusion Pulp treatment Milk of lime and carbonation Juice purification Sedimentation and filtration Juice evaporation Juice decolorization and sulfination Juice storage Production of specilized sugar product and packaging
2-CANE SUGAR Ø Sugarcane, like wheat, rice, corn and other grains, is of the grass family, Gramineae, characterized by segmented stems, blade-like leaves, and reproduction by seed. Ø Sugarcane is a tropical plant; it has no adaptation to survive freezing and it is dependent on abundant sunlight for healthy growth. Ø The sugarcane plant itself is of the genus Saccharum. Ø The Saccharum has five extant species; two wild (S.spontanium and S.robustum) and three cultivated (S.officinarum, S.barberi and S.sinense).Wild species do not have sugar content. S. Officinarum is the noble sugar cane specie.
Sugar cane is the world’s biggest crop. ØIt has a large amount of sugar(sucrose). Approximately 15%, maximum 20%. Ø80% of it is used for sugar production. ØBrazil, China, India, Cuba, Thailand are some of the biggest producer countries.
SUGAR PRODUCTION FROM SUGAR CANE
DETAILS OF PROCESSING STEPS (Home Study)
DRY CLEANING • The dry cleaning operation is a valuable environmental benefit and a cost savings for the factory.
F LU M E WAT E R T R E AT M E N T
Beet slicing Slicing beets is the process of cutting beets into long, thin strips, called cossettes.
JUICE DIFFUSION Continuous diffusers can be divided into three main groups: ■ Tower diffusers ■ Slope diffusers ■ Drum diffusers
FACTORS INFLUENCING THE DIFFUSION PROCESS Factors influencing the diffusion operation are the following: q pH q Draft q Temperature q Retention time q Cossette quality q Microbiological activity
PULP TREATMENT Pulp dryers are of two types: ■ Drum dryer ■ Steam-powered dryer
MILK-OF-LIME AND CARBONATION
JUICE PURIFICATION • The purification of the diffusion juice occurs in a two-step operation: • ■ Liming • ■ Carbonation (CaO + CO2 → CaCO3↓). • The goals of juice purification are as follows: Ø ■ Removal of all insoluble substances Ø ■ Removal of certain soluble substances (nonsugars) Ø ■ Production of a thermostable juice with minimum hardness
• It is helpful to outline the classical juice-purification process (for orientation which consists of the following 13 steps: • 1. Diffusion-juice heating : The diffusion juice is heated to about 86ºC. • 2. Preliming: Lime (at a small amount of 0.2 to 0.7% OB) is added to the juice to reach an alkalinity of about 0.15% CaO and about 8.5 pH value. • 3. Prelimed-juice heating: Prelimed juice is heated to about 88ºC. • 4. Mainliming: More lime is added to the juice (1.0 to 2.0% OB) to obtain a pH of about 12.0 to complete the reactions of the nonsucroses with the lime. • 5. Limed-juice heating : Limed juice is heated to about 90ºC. • 6. First carbonation: Carbonation gas is added to the juice to reach a pH of about 10.8 to precipitate the excess lime and limesalts (hardness).
• 7. Mud separation: The precipitate from the first-carb juice is separated by using mudseparation equipment, such as clarifi ers or fi lter thickeners, to produce clear juice and a thicker product, called carbonation mud. • 8. Mud thickening: The mud is further thickened in cake fi ters (rotary-drum filters or filter presses) to produce limecake, also known as carbonation-lime residue (a by-product of the beet-sugar factory). • 9. First-carb filtration: The clear juice from clarifiers (or thickening filters) is filtered with the first-carb fi lters. • 10. First-carb juice heating : The filtered juice is heated to about 92ºC.
• 11. Second carbonation: More gas is added to the juice to reach a pH of a about 9.0 to precipitate (as much as possible) the excess lime and limesalts. • 12. Second-carb filtration: The juice is filtered by second- carb filters. • 13. Second-carb safety filtration: The filtrate is filtered again by safety filters to prevent any fine, suspended solids entering the evaporators. (Note: Not all factories are equipped with safety filters.) • Several purifi cation systems (such as BMA, DDS, DORR, and Putsch) use the defeco technique. Here, three common systems are explained: • ■ BMA system (used all over the world) • ■ DDS system (used mostly in Europe) • ■ Dorr system (used mostly in the United States)
SEDIMENTATION AND FILTRATION This section talks about of to produce clear thin juice. If sedimentation (settling) and filtration are not performed properly, the juice purification station is affected, which may slow or shut down other stations as well. (CaO + CO2 → CaCO3↓).
TYPES OF FILTERS Ø Pressure-leaf (U.S.) filters Ø■ Centrifugal filters Ø■ Screen (Sibomat) filters Ø■ Bag-pressure filters ØRotary-Drum Filters
JUICE EVAPORATION • A single-effect evaporation operation is not efficient because the vapor has a large amount of energy and low pressure. Therefore, sugar factories use multiple-effect evaporation, in which the partially concentrated juice leaving the first effect is introduced into the second effect, and the vapor produced from the first effect is used as a heating medium to heat the second effect.
HEAT EXCHANGERS • ■ Tube heat exchanger (Robert, Thin-film evaporators ) • ■ Plate heat exchanger
JUICE DECOLORIZATION AND SULFITATION (Note: Because the color of in-process products is different from factory to factory and even in the same factory from one day to the next) The chemistry of color formation is too complex to indicate with simple chemical equations.
COLOR FORMATION IN SUGARBEET PROCESSING • Colorants are not present in beet juice but are formed during the processing (sugarbeet is an off-white color, but processed beet juice is colored). During processing, colorants in in-process products form because of the following reasons: • ■ High pH • ■ High temperature • ■ Interaction of organic nonsugars
JUICE DECOLORIZATION • Juice decolorization is performed by two methods: • Decolorization by ion-exchange resin • Decolorization by activated carbon
JUICE SULFITATION • Juice Sulfitation is the process of adding sulfur dioxide (SO2) to the juice to reduce color and prevent color formation in the next steps of operation. SO2 inhibits the browning (Maillard) reaction that forms coloring compounds during evaporation and crystallization. • It is used also as a biocide to kill microorganisms in the diffuser
JUICE STORAGE • STORAGE CONDITIONS Juice storage requires a high level of care before and during storage. The following factors have to be considered: • ■ Dry substance • ■ pH • ■ Purity • ■ Temperature • ■ Filtration • ■ Cleanliness
SYRUP CRYSTALLIZATION Three classes of crystallization: Two types of crystallizers are used in ü Flashing crystallization sugar plants: (crystallization by evaporation Ø Evaporating crystallizers under vacuum) Ø Cooling crystallizers ü Evaporating crystallization Evaporating crystallizers are of two (crystallization by evaporation) types: Ø Batch crystallizers ü Cooling crystallization Ø Continuous crystallizers (crystallization by cooling)
Sugar Drying, Storing, And Packing Flow diagram of sugar drying, storing, and packing
Control Parameters During Sugar Beet Production 1- Debris ,dirt, soil etc. component • 2-Debris ,dirt, soil etc. component • 3-Debris ,dirt, soil etc. component • 4-Stone and trash component • 5-Clearity total mass component • 6-Temperature, Ph • 7-Flow rate, Pressure,Density, Color … • 8-Pressure, Ph, Kss, dry substance concentration, hardness of molasses,sosa ash requırement, rection time,BOD, COD,( Pressing) • 9- Flow rate, Pressure,Density, Color,Turbidity, Ph, temperature • 10-Purity, Turbidity, Flow rate, Pressure,Density, Ph,( Purif )
• 11-Purity, Turbidity, Flow rate, Pressure,Density, Filter cake resistant, Rate of carbonization, • 12-Amount of heat and flow requirement, heat loss • 13-Flow rate, Pressure,Density, Color,Turbidity, temperature, Ph, • 14-Flow rate, Pressure,Density, Color,Turbidity, temperature, saturation coefficient of mother • 15-liquior,viscosity, Sulfide amount, • 16-Density, Color, purity, viscosity • 17-Size of cristallization, density, color, • 18-hardness of molasses,viscosity of molasses, pestisides, • 19-Color, density,vacuum, • 20-Color, density, purity, level of sugar…
CONTROL IN CANE-SUGAR MANUFACTURE
PRODUCTION OF DIFFERENT SUGARS Specialty sugars are all sugar products except the normal crystal size granulated-refined sugar (GR sugar). This definition includes: Ø Special crystal-size sugar Ø Powdered sugar Ø Brown sugar Ø Cube sugar Ø Adant sugar Ø Candy-crystal sugar Ø Cone sugar (loaf sugar) Ø Liquid and liquid invert sugar
BY PRODUCTS •Ethanol •Bioelectricity •Bioplastics •Biohydrocarbons •Animal feed
ETHANOL Sugarcane ethanol is an alcohol-based fuel produced by the fermentation of sugarcane juice and molasses. Because it is a clean, affordable and low-carbon biofuel, sugarcane ethanol has emerged as a leading renewable fuel for the transportation sector. Ethanol can be used two ways: -Blended with gasoline at levels ranging from 5 to 25 percent to reduce petroleum use, boost octane ratings and cut tailpipe emissions. -Pure ethanol – a fuel made up of 85 to 100 percent ethanol depending on country specifications – can be used in specially designed engines.
Bioelectricity Brazilian sugarcane mills learned to harness the energy stored in bagasse by burning it in boilers to produce bioelectricity. As a result, these mills are energy self-sufficient, producing more than enough electricity to cover their own needs. A growing number of mills also generate a surplus, which is sold to distribution companies and helps to light up numerous cities throughout Brazil. In early 2010, sugarcane mills supplied about 2,000 average megawatts, or 3 percent of Brazil’s electricity requirements, thanks to bioelectricity. Bioplastics With volatile oil prices and growing concerns about greenhouse gas emissions, the chemical industry is looking for renewable alternatives to diversify its sources of raw materials. Sugarcane ethanol has emerged as an important ingredient to substitute for petroleum in the production of plastic. These so -called “bioplastics ” have the same physical and chemical properties as regular plastic (the most common type is known technically as PET) and maintain full recycling capabilities.