P.Kadlec - Sugar

Transcription

1 P.Kadlec - Sugar

2 Sugar Technology P.Kadlec - Sugar

3 SUGAR PRODUCTION IN CR AND IN THE WORLD Start of industrial sugar production in Czech - year 1831 Sugar production in CR thousands t per year - domestic consumption 400 thousands t per year Production costs The important costs: price of sugar beet 53 % transport of beet 7 % production costs in sugar factory 36 % storage of sugar 4 % P.Kadlec - Sugar

4 CHOSEN CHARACTERISTICS OF SUGAR BEET AND SUGAR PRODUCTION IN CR CR EU Sugar beet yield (t/ha) Area on 1 farmer (ha) Content of sugar (%) Yield (%) Yield of refined sugar (t/ha) Av.capacity of sugar factory (t/d) Maximum sugar beet yield in France - more than 90 t/ha for content of sugar 16 %, in CR 80 t/ha for content of sugar 16 %. Yield of refined sugar: France t/ha, Switzerland, Belgium, The Netherland t/ha Great Britain, Denmark, Germany, Austria, CR more than 11 t/ha P.Kadlec - Sugar

5 WORLD PRODUCTION AND CONSUMPTION OF SUGAR 20 % FROM SUGAR BEET (thousands t) production consumption P.Kadlec - Sugar

6 SHARE OF WORLD SUGAR PRODUCTION ACCORDING TO CONTINENTS P.Kadlec - Sugar

7 World prices of sugar do not reflect of production costs it is followed by: market mechanism of the offer and request situation in world sugar reserves Oscillation of world prices of sugar on stock market White sugar Raw sugar P.Kadlec - Sugar

8 SUGAR and its use in human nutrition to chemical and biochemical transformations Very long time of storage (years) Relative low price SUGAR AS FOOD to ensure the significant portion of total energy intake large offer of industrial and workshop produced foods direct household consumption of sugar Function of sugar: sweetener flavour conservation media matter giving of food volume matter finishing of food texture substrate of fermentation Consumption of sugar in CR - 35 kg per head and year Recommended consumption according to Health Nutrition: 60 g/day, it is 22 kg/year High sugar consumption and health diseases P.Kadlec - Sugar

9 SUGAR AS RAW MATERIAL FOR CHEMICAL AND BIOCHEMICAL TECHNOLOGIES only 5 % of sugar world production is used for nonfood use products of chemical or biochemical transformations of sucrose are biological degradable and are not toxic The possibilities of production coming out from sucrose: fermentation to bioethanol, the following use as fuel or additives to fuel clasical fermentation production (spirit, yeasts, organic solvents and acids (citric, lactic), vinegar, aminoacids) products of chemical transformation of sucrose (sorbitol, vitamin C, gluconic acid, 5-hydroxymethylfurfural, ) P.Kadlec - Sugar

10 BASIC ANALYTICAL TERMS Dry substances S (%) Sucrose P (%) Nonsugars N = S - P Purity Q = P/S. 100 Ash A (%) Reducing substances, RL (%) Invert sugar P.Kadlec - Sugar

11 SUGAR Sugar beet BEET - Cultivation to maximal content of sucrose - In conditions of good earth (soil) - In mild climatic area - For long vegetation time - Area of earth suitable for growing of sugar beet in CR 700 thousands ha - Sugar beet is growing on area 60 thousands ha - surrounding of rivers Labe, Vltava, Ohře, Haná - south Moravia, Opavsko (Silesia) P.Kadlec - Sugar

12 Composition of a typical sugarbeet Sugarbeet 75% Water 25% Dry substance 18-20% Beet juice 5% Beet marc 17.5% Sucrose 2.5% Nonsucroses 1.1% Nitrogenous 2.4% Pectin (0.2% amino acids, 0.1% betaine, etc.) 1.2% Cellulose 0.9% Non-nitrogenous 1.1% Hemicellulose (0.3% invert sugar, 0.2% raffinose, etc.) 0.1% Protein 0.3% Minerals 0.1% Saponin (K +, Na +, Ca 2+, Mg 2+, SO 2 4, PO 3 4 ) 0.1% Minerals 0.2% Others P.Kadlec - Sugar

13 Modern sugar beet laboratory determination of soil content (mineral matters) and green plants materials analytical determination sucrose (sugar) natrium and kalium amidic nitrogen calculation of preliminary yield of refined sugar, resp. losses of sugar in molasses according of composition of sugar beet sample polarimeter dilutor Flame photometer dilutor spectrophotometer converter P.Kadlec - Sugar

14 HANDLING OF BEET AND RAW JUICE EXTRACTION Beet stock Water Water Ballast separation Washing Stones, sand Trash Treatment of water Water Slicing of cossettes Extraction Pressing Soil mud Disinfection agents Raw juice Q=86-90 % Pressed pulp S=20%, P=0.5% Conditions of extraction: temperature < 80 C, time < 120 min, ph 5.8 P.Kadlec - Sugar

15 Cossettes - 1 Raw juice - 2 Extractor Pulp - 4 Water - 3 Material balance of the diffusion process m 1 S 1 = m 2 S 2 + m 4 S 4 m 1 P 1 = m 2 P 2 + m 4 P 4 calculation of draft m 2 (% beet) S 4 P 1 - S 1 P 4 m 2 = m 1 S 4 P 2 - S 2 P 4 usual value of draft of raw juice % beet P.Kadlec - Sugar

16 Extractors Tower Slope Drum 60 C 74 C 74 C 72 C water steam Slope extractor - scheme of measurement and control SŘ cossettes; SŠ raw juice; VŘ pulp; ŘV pulp press water; T temperature; F - flow rate; L level; I indication; C - control P.Kadlec - Sugar

17 Microbial contamination during extraction Source of unknown losses about 0.1 % or more Sources of microbial contamination: rest of soil on surface of beet transport and wash water fresh water chiefly pulp press water Raw juice is ideal mediums for microorganisms activity contents of sucrose, aminoacids, amids, organic acids, proteins, pectins, ph is about 6.0 temperature C Aerobic and unaerobic soil bacteria decomposite the carbohydrates the main degradation product is lactic acid ph of juice decreases under 5.8 (at 20 C) formation of gases reduction of nitrates to nitrites P.Kadlec - Sugar

18 PULP Pulp Pulp pressing dry matter %, max % effectivity of pressing depends on: physical properties of cossettes temperature C ph The lower ph the better pulp pressing Influence of soluble pectin and its decomposition products Pulp Dry Use matter (%) Low pressed direct feeding, ensilage High pressed ensilage (min. losses, high quality) Dried granulated fodder, pelets Beet fiber supplement of fiber for human nutrition (dietary substance; prevention of civilizing deseases) P.Kadlec - Sugar

19 Pulp drying too high expensive process as regards of power consumption ways how to reduce energy consumption during drying of pulp: Maximal mechanic dewatering by pressing (power consumption is 60 kj/kg water in comparison with 3000 kj/kg water for thermal dewatering) Predrying of pressed pulp to dry substance % by using of waste heat of barometric water or condensates Use of preheated steam for pulp drying air 20 C pulp S=18-22 % barometric water heated air C output air saturated by water predried pulp S = % Dried pulp is used to preparation of fodder mixtures and pelet fodders P.Kadlec - Sugar

20 Raw juice Dry matter % Purity % ph Colour Contains grey-black sucrose colloid dispersed substances pectines proteins colour matters saponins the others nonsucros P.Kadlec - Sugar

21 Main objectives: Juice purification 1) To remove about % of nonsugars 2) To neutralize the acid reaction of raw juice 3) To minimaze degradation of sucrose 4) To disinfect of juice 5) To remove fine pulp particles For purification of juice is used: lime milk (hydrated suspension Ca(OH) 2 and CaO in water) kiln gas (content about 30 % vol. CO 2 ) P.Kadlec - Sugar

22 Raw juice, Q=86-90 % Lime milk Preliming - ph 11 Lime milk Main liming ph 12.5 Kiln gas CO 2 1st carbonation ph 11 Thickening of slurry Kiln gas CO 2 Filtration 2nd carbonation ph Carbonation lime; mud P<1 %; S=60-70 % Filtration Thin juice, Q=90-94 % P.Kadlec - Sugar

23 Use of steam to production of electric energy Steam production to multiple evaporation of juice in evaporation plant and using of vapor for heating in technology steam reduction station superheated steam reduced steam steam saturator and cooler electric generator return steam steamboiler feed boiler boiler feed water condensate steam to evaporation station P.Kadlec - Sugar

24 Juice evaporation The main goal of evaporation station: 1. to concentrate of juice to % 2. to supply production units with needed steam for heating Quantity of evaporated water m w (% b.) m w = m 1 (1-S 1 /S 2 ) For m 1 = 120 %, S 1 = 16 %, S 2 =65 %, then m w = 90 % b. To evaporation of m w kg water is need the heat Q w Q w = m w. r (kj) where r is heat of water evaporation at temperature t (kj/kg) Rough presumption: to evaporation of 1 kg water from juice heat-up to boiling point is consumption 1 kg of steam P.Kadlec - Sugar

25 Robert evaporator Vapor splash head Noncondensable gases Steam tubes Juice feed Juice outlet O d v Condensate P.Kadlec - Sugar

26 to barometric condenser Thin juice S=15 % Thick juice S=65 % to steam boiler plant hot condensate Scheme of evaporator station P.Kadlec - Sugar

27 Crystallization process CRYSTALLIZATION OF SUGAR 1) nucleation (formation of nuclei/seed) 2) crystal growth need conditions for nucleation and crystal growth is existence of supersaturated sugar solution driving force of nucleation and crystal growth is difference between actual concentration in solution and concentration of saturated solution (supersaturation) Supersaturation of sugar solution is expressed as supersaturation coefficient Kp Kp = H/H 1, H - weight ratio P/W in solution H 1 - weight ratio P/W in saturated solution K growth rate of crystallization in steady state v v = K. (Kp - 1) constant of crystallization P.Kadlec - Sugar

28 Metastable zone no creation of new nucleus, only growth crystals zone of supersaturation suitable for evaporation and cooling crystallization limits of metastable zone are influenced chiefly by temperature, purity and presence of crystals the lower limit correspond to saturated solution P.Kadlec - Sugar

29 SUGAR BOILING evaporation crystallization in vacuum pan massecuite centrifugation cooling crystallization 1-reservoirs 2-vacuum pan 3-barometric condenser 4-crystallizer 5-distributing trough 6-centrifuge 7-sirup 8-sugar P.Kadlec - Sugar

30 Automatization of sugar boiling the main input - supersaturation auxiliary quantities crystals content, level in pan To expression of supersaturation is used: electric conductivity viscosity (consistence) Course of viscosity during sugar boiling P.Kadlec - Sugar

31 Conventional massecuite boiling 1) Preparation 2) Concentration 3) Seeding 4) Stabilization of nuclei 5) Crystal growth 6) Concentration 7) End of boiling Boiling of massecuite with magma inoculation seed 1) Preparation to boiling 2) Seeding of inoculation magma mixture of B/C sugar + crystal sirob 3) Crystal growth boiling 4) Concentration of massecuite 5) End of boiling Advantages: Improving of grain size analysis of boiled crystal Energy saving (steam) during shortened time of boiling Simplification of boiling scheme P.Kadlec - Sugar

32 vacuum pans control room crystallizers centrifuges P.Kadlec - Sugar

33 A-massecuite Thick juice White Green A-sugar crystal syrup crystal syrup Magma B-massecuite Magma C-massecuite B seed C seed B-sugar Green C-sugar Molasses B-syrup B-magma C-magma White Green White Green B-aff.syrup B-aff.syrup C-aff.syrup C-aff.syrup 1st aff.sugar Thin juice 2nd aff.sugar or water Liquor P.Kadlec - Sugar

34 Molasses Composition: S = %, Q = %, A = 10 % ph > 8,3 Use of molasses 1) as animal fodder 2) raw material to biotechnology - fermentation production (spirit, yeast, fodder yeast, organic acids - citric, lactic, vinegar, organic solvents, aminoacids) - modern biotechnological production 3) isolation of nitrogen substances (betaine, aminoacids, ) 4) desugaring process - separation of sucrose as calcium sacharate - Steffen process - Separation of nonsugars by means of ionexchangers - demineralisation or ione exclusion - sugar fraction is treated as liquid sugar - nonsugar fraction is treated as fodder or fertilizer P.Kadlec - Sugar

35 Raw sugar (B, C) Magma preparation Affination Liquor preparation Filtration Decolorization Boiling of massecuite Centrifugation Drying end moisture 0.05 % Liquid sugar Classification of crystals Milling Packaging Pressed cube Scheme of refinery P.Kadlec - Sugar

36 Screening maschine Vibrating screens Sugar screening Minimal content of the main fraction for sugar crystal and powder (%) Lenght of square side of sieve mesh (mm) Crystal Fine crystal Powdered sugar P.Kadlec - Sugar

37 Weibull sugar silo Conditions of sugar storage in silos Sugar perfect dust off uniform quality moisture % temperature % ash 0.02 % reducing compounds 0.01 % Air relative humidity % P.Kadlec - Sugar 2015 temperature C 37 small overpressure inside silo

38 Equilibrium moisture of sugar (%) Relative moisture of air (%) Course of sorptive isotherms for crystals of various quality 1 the lowest quality, 2 the medium quality, 3 the highest quality P.Kadlec - Sugar

39 Types of sugar according Czech Food Law Group Subgroup Sugar extra crystals mixture of crystals caster sugar mixture of smaller crystals or pulverized crystals powder mixture of fine pulverized crystals Sugar white crystals caster sugar powder Sugar semi-white crystals caster sugar powder Powdered sugar can include (max. 3 %) anti caking agent Pressed cube sugar (cube, bridge, loaf) Sugar with additives Natural sugar bulk, granular, light yellow crystal, slightly sticky Candys mixture of big crystals, yellow brown color Liquid products invert syrup caramel P.Kadlec - Sugar

40 Physical and chemical requierements on sugar quality according Czech Food Law Extra-white White Semi-white Sucrose Ash Invert sugar Moisture Color in solution P.Kadlec - Sugar