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Manu report


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Manu report

  2. 2. CERTIFICATEThis is hereby declare that the project work entitled “PROCESS OFSUGAR MANUFACTURING ” submitted by Mohit Saxena to LALITHARI SUGAR FACTORY PILIBHIT (U.P.) for the award of theINDUSTRIAL TRAINING is a genuine record of the work carried out bythem during the period of 15 JUNE, 2011 to 15 JULY, 2011.It is further certified that this project has been developed by Mohit Saxena, in original and has been the result of their personal efforts with littleassistance wherever required. Mr…………………… Project Incharge LALIT HARI SUGAR FACTORY PILIBHIT (U.P.)
  3. 3. ACKNOWLEDGEMENTA very special thanks to Mr. …………………..Training incharge (LHSFPILIBHIT) for providing us with the opportunity to avail the excellentfacilities and infrastructure in terms of the faculty, the computer lab, thelibrary, and last but not the least, the ambience which served as the turningpoint of my career.We are also grateful to the college for providing us with the opportunity towork with them and undertake a project of such importance. MOHIT SAXENA B.Tech. (VII SEMESTER) S.R.M.S.C.E.T., Bareilly
  4. 4. DECLARATIONWe hereby declare that this submission is our own work which is beingpresented in the project work entitled “STUDY OF SUGARMANUFACTURING“ in partial fulfillment of requirement for the award of thedegree INDUSTRIAL TRAINING at LALIT HARI SUGAR FACTORYPILIBHIT (U.P.) is an authentic record of the work carried out by us duringthe period of 16/06/2011 to 15/07/2011 and that, to the best of ourknowledge and belief.It contains no material previously published or written by another person normaterial which to a substantial extent has been accepted for the aware ofany other degree or diploma of the university or other institute of higherlearning except where the acknowledgement has been made in the text.
  5. 5. MOHIT SAXENACONTENTS OF THE REPORT:AbstractL.H.sugar factory‟s profileSugar manufacturingProcess chartThe Energy Aspects  Millhouse  Boilerhouse  Powerhouse  Clarification and boiling house:  Boiling and curing house  Cogeneration powerMolassesChallenges for sugar industry  Conclusions and suggestions
  6. 6. INDIAN SUGAR INDUSTRY - A STRONG INDUSTRIAL BASE FOR RURAL INDIAABSTRACTIndian sugar industry, second largest agro-based processing industry aftethe cotton textiles industry in country, has a lions share in acceleratingindustrialization process and bringing socio-economic changes in underdeveloped rural areas. Sugar industry covers around 7.5% of total ruralpopulation and provides employment to 5 lakh rural people. About 4.5 crorefarmers are engaged in sugarcane cultivation in Inda. Sugar mills(cooperative, private, and public) have been instrumental in initiating anumber of entrepreneurial activities in rural India. Present paper is anattempt as to review progress of sugar industry in India, understand itsproblems and challenges in context of ongoing liberalization process.Indian sugar industry can be a global leader provided it comes out of thevicious cycle of shortage and surplus of sugarcane, lower sugarcane yield,lower sugar recovery, ever increasing production costs and mountinglosses. It needs quality management at all levels of activity to enhanceproductivity and production. Attention is required on cost minimization andundertaking by product processing activities. MOHIT SAXENA
  7. 7. L.H.SUGAR FACTORY’S PROFILE L.H. Sugar Factories Ltd. is located near Tanakpur Road in Pilibhit (U.P.). Nearest Railway Station is Pilibhit at the distance of 0.5 km. The factory started its crushing operation in the year 1910. The licensed crushing capacity of the plant was 300 TPD, 650 TPD. In 1928‟ 1300 TPD in 1932-33, 3500 TPD in 1986-87, 5500 TPD in 2001-02, 6000 TPD in 2002-03, 7200 TPD in 2004-05, 8000 TPD in 2005-06, 10000 TPD in 2006-07 and now the capacity of the plant is 11000 TPD 49522
  8. 8. Some important data related to L.H.S.F. is:  Cane Crushing Capacity : 10,000 TPD  Process Used : Double Sulphitation  Steam Generation : 245 Tonnes/Hour  Total Power Generation(installed) : 46 MWH  Normal Power Generation : 40 MWH  Avg. Exported Power : 25 MWH  Plant Consumption : 15 MWH
  9. 9.  Avg. Sugar Production : 9000 Quintals/Day  Avg. Molasses production : 4000 Quintals/Day  Avg. Press Mud Prodution : 3500 Quintals/DaySUGAR MANUFACTURINGThe HistoryIt is thought that cane sugar was first used by man in Polynesia from whereit spread to India. In 510 BC the Emperor Darius of what was then Persiainvaded India where he found "the reed which gives honey without bees".The secret of cane sugar, as with manyother of mans discoveries, was kept aclosely guarded secret whilst thefinished product was exported for a richprofit.It was the major expansion of the Arabpeoples in the seventh century AD thatled to a breaking of the secret. Whenthey invaded Persia in 642 AD theyfound sugar cane being grown and learnt how sugar was made. As theirexpansion continued they established sugar production in other lands thatthey conquered including North Africa and Spain.Sugar was only discovered by western Europeans as a result of theCrusades in the 11th Century AD. Crusaders returning home talked of this"new spice" and how pleasant it was. The first sugar was recorded inEngland in 1099. The subsequent centuries saw a major expansion ofwestern European trade with the East, including the importation of sugar. Itis recorded, for instance, that sugar was available in London at "twoshillings a pound" in 1319 AD. This equates to about US$100 per kilo attodays prices so it was very much a luxury.In the 15th century AD, European sugar was refined in Venice, confirmationthat even then when quantities were small, it was difficult to transport sugaras a food grade product. In the same century, Columbus sailed to theAmericas, the "New World". It is recorded that in 1493 he took sugar cane
  10. 10. plants to grow in the Caribbean. The climate there was so advantageousfor the growth of the cane that an industry was quickly established.By 1750 there were 120 sugar refineries operating in Britain. Theircombined output was only 30,000 tons per annum. At this stage sugar wasstill a luxury and vast profits were made to the extent that sugar was called"white gold". Governments recognised the vast profits to be made fromsugar and taxed it highly. In Britain for instance, sugar tax in 1781 totalled£326,000, a figure that had grown by 1815 to £3,000,000. This situationwas to stay until 1874 when the British government, under Prime MinisterGladstone, abolished the tax and brought sugar prices within the means ofthe ordinary citizen.Sugar beet was first identified as a source of sugar in 1747. No doubt thevested interests in the cane sugar plantations made sure that it stayed asno more than a curiosity, a situation that prevailed until the Napoleonicwars at the start of the 19th century when Britain blockaded sugar importsto continental Europe. By 1880 sugar beet had replaced sugar cane as themain source of sugar on continental Europe. Those same vested interestsprobably delayed the introduction of beet sugar to England until the FirstWorld War when Britains sugar imports were threatened.One of the most important examples of governmental actions is within theEuropean Union where sugar prices are so heavily subsidised that over 5million tons of white beet sugar have to be exported annually and yet amillion tons of raw cane sugar are imported from former colonies. Thislatter activity is a form of overseas aid which is also practised by the USA.The EUs over-production and subsequent dumping has now beensubjected to GATT requirements which should see a substantial cut-back inproduction over the next few years. An interactive World Map of Sugar production
  11. 11. IntroductionSugar is made by some plants to store energy that they dont need straightaway, rather like animals make fat. People like sugar for its sweetness andits energy so some of these plants are grown commercially to extract thesugar:Sugar is produced in 121 Countries and global production now exceeds120 Million tons a year. Approximately 70% is produced from sugar cane, avery tall grass with big stems which is largely grown in the tropicalcountries. The remaining 30% is produced fromsugar beet, a root crop resembling a largeparsnip grown mostly in the temperate zones ofthe north.What we call sugar, the chemist knows assucrose, one of the family of sugars otherwiseknown as saccharides in the grouping calledcarbohydrates. Carbohydrates, as the nameimplies, contain carbon and hydrogen plusoxygen in the same ratio as in water. The saccharides is a large family withthe general formula CnH2nOn. The simplest of the sugars is glucose,C6H12O6, although its physical chemistry is not that simple because itoccurs in two distinct forms which affect some of its properties. Sucrose,C12H22O11, is a disaccharide, a condensation molecule made up of twoglucose molecules [less a water molecule to make the chemistry work].The process whereby plants make sugars is photosynthesis. The planttakes in carbon dioxide from the air though pores in its leaves and absorbswater through its roots. These are combined to make sugar using energyfrom the sun and with the help of a substance called chlorophyll.Chlorophyll is green which allows it to absorb the suns energy more readilyand which, of course, gives the plants leaves their green colour. Thereaction of photosynthesis can be written as the following chemicalequation when sucrose is being made: 12 CO2 + 11 H2 O = C12 H22 O11 + 12 O2 carbon dioxide + water = sucrose + oxygenThis shows that oxygen is given off during the process of photosynthesis.
  12. 12. Historically, sugar was only produced from sugar cane and then only inrelatively small quantities. This resulted in it being considered a greatluxury, particularly in Europe where cane could not be grown. The history ofman and sugar is a subject in its own right but suffice to say that, eventoday, it isnt easy to ship food quality sugar across the world so a highproportion of cane sugar is made in two stages. Raw sugar is made wherethe sugar cane grows and white sugar is made from the raw sugar in thecountry where it is needed. Beet sugar is easier to purify and most is grownwhere it is needed so white sugar is made in only one stage.PROCESS CHART
  13. 13. SugarCaneSugar cane is a genus of tropical grasses which requires strong sunlightand abundant water for satisfactory growth. The Latin names of the speciesinclude Saccharum officinarum, S. spontaneum, S. barberi and S. sinense.As with most commercial crops, there are many cultivars available to thecane farmer, usually hybrids of several species. Some varieties grow up to5 metres tall.The cane itself looks rather like bamboo cane and it is here that thesucrose is stored. In the right climate the cane will grow in 12 months and,when cut, will re-grow in another 12 months provided the roots areundisturbed.A typical sugar content for mature cane would be 10% by weight but thefigure depends on the variety and varies from season to season andlocation to location. Equally, the yield of cane from the field variesconsiderably but a rough and ready overall value to use in estimating sugarproduction is 100 tons of cane per hectare or 10 tons of sugar per hectare. SugarBeet Sugar beet is a temperate climate biennial root crop. It produces sugar during the first year of growth in order to see it over the winter and then flowers and seeds in the second year. It is therefore sown in spring and harvested in the first autumn/early winter. As for sugar cane, there are many cultivars available to the beet farmer. The beet stores the sucrose in the bulbous root which bears a strong resemblanceto a fat parsnip.A typical sugar content for mature beets is 17% by weight but the valuedepends on the variety and it does vary from year to year and location tolocation. This is substantially more than the sucrose content of mature canebut the yields of beet per hectare are much lower than for cane so that theexpected sugar production is only about 7 tons per hectare.
  14. 14. The World of Sugar Production : Mid 1990s AUSTRALIA Exports: 4.7 million tons Production: 5.5 million tons Population: 19 million Per Capita Consumption: 45 kg BRAZIL Exports: 6 million tons Production: 14.5 million tons Population: 167 million Per Capita Consumption: 48 kg E.U. Exports: 5.5 million tonsExtraction
  15. 15. There are several important aspects to extraction which involve the energybalance of the factory, the efficiency of extraction and therefore ultimatelythe profitability of operations: The manager needs to process the cane as soon as possible if sugar losses are to be avoided yet needs to have a sufficient supply in storage for times when cutting and transport are stopped, whether deliberately or not. Typically, cane is processed within 24 hours of cutting; Cane preparation is critical to good sugar extraction, particularly with diffusion extraction. This is achieved with rotating knives and sometimes hammer mills called "shredders". However shredding requires extra energy and more equipment; The extraction is actually conducted as a counter-current process using fresh hot water at one end being pumped in the opposite direction to the cane. The more water that is used, the more sugar is extracted but the more dilute the mixed juice is and hence the more energy that is required to evaporate the juice; The more accurately that the mills are set [adjusted], the drier is the residual fibre and hence the less sugar remaining in the fibre;A typical mixed juice from extraction will contain perhaps 15% sugar andthe residual fibre, called bagasse, will contain 1 to 2% sugar, about 50%moisture and some of the sand and grit from the field as "ash". A typicalcane might contain 12 to 14% fibre which, at 50% moisture content givesabout 25 to 30 tons of bagasse per 100 tons of cane or 10 tons of sugar.HarvestingCane grows very tall in good growing regions - certainly up to 3 metres/10 feet tall - and still has some green leaves when ripe although most leaves have dried off by then. Where possible the cane is fired before harvesting to remove the dead leaf material and some of the waxy coating. The fire burns at quite high temperatures but is over very quickly so that the cane and its sugar
  16. 16. content are not harmed.In some areas burning is not permitted because of the nuisance value tolocal communities of the smoke and carbon specs that are released.However there is no environmental impact, the CO2 released being a verysmall proportion of the CO2 fixed with photosynthesis during growth and theimproved sugar extraction meaning that less cane needs to be grown onfewer acres to satisfy the worlds sugar demand.Harvesting is done either by hand or by machine. Hand cut cane -- canecutting is a hard and dirty job but can employ lots of people in areas wherejobs are scarce -- is cut at about ground level, the top green leaves arecropped off and then the stalk is bundled whole. Once a complete bundlehas been assembled it is removed from the field with a light cart and maythen be transferred to a largervehicle for transport to the mill.Most machine-cut cane is choppedinto short lengths but is otherwisehandled in a similar way as hand cutcane. Machines can only be usedwhere land conditions are suitableand the topography is relatively flat.In addition the capital cost ofmachines and the loss of jobscaused makes this solution unsuitable for many sugar estates.Evaporation
  17. 17. The mixed juice from extraction is preheated prior to liming so that theclarification is optimal. The milk of lime, calcium hydroxide or Ca(OH)2, ismetered into the juice to hold the required ratio and the limed juice enters agravitational settling tank: a clarifier. The juice travels through the clarifier ata very low superficial velocity so that the solids settle out and clear juiceexits.The mud from the clarifier still contains valuable sugar so it is filtered onrotary vacuum filters where the residual juice is extracted and the mud canbe washed before discharge, producing a sweet water . The juice and thesweet water are returned to process.The clear juice has probably only 15% sugar content but saturated sugarliquor, required before crystallisation can occur, is close to 80% sugarcontent. Evaporation in a steam heated multiple effect evaporator is thebest way of approaching the saturated condition because low pressurewater vapours can be produced for heating duties elsewhere in the factory.The evaporator sets the steam consumption of the factory and is designedto match the energy balance of the entire site: the manager wants to avoidburning auxiliary fuel and equally wants to avoid paying to dispose ofsurplus bagasse. The greater the number of effects, the less steam isrequired to drive the first effect. Each subsequent effect is heated by thevapour from the previous effect so has to be operated at a lowertemperature and therefore lower pressure.
  18. 18. BoilingPhysical chemistryassists with sugarpurification during thecrystallisation processbecause there is a naturaltendency for the sugarcrystals to form as puresucrose, rejecting thenon-sugars. Thus, whenthe sugar crystals aregrown in the motherliquor they tend to bepure and the motherliquor becomes moreimpure. Most remainingnon-sugar in the productis contained in thecoating of mother liquorleft on the crystalsThe mother liquor stillcontains valuable sugarof course so thecrystallisation is repeated several times. However non-sugars inhibit thecrystallisation. This is particularly true of other sugars such as glucose andfructose which are the breakdown products of sucrose. Each subsequentstep therefore becomes more difficult until one reaches a point where it isno longer viable to continue.The crystallisation step itself - a "boiling" - takes place in a vacuum pan: alarge closed kettle with steam heated pipes. [In practice the heating is donewith a low pressure water vapour from the evaporator.] Some modern pansare continuous flow devices but most are batch devices which go through adiscrete cycle and are then emptied for a new boiling. A typical cycle mightbe 4 hours long. The mixture of crystals and mother liquor from a boiling,called the "massecuite", is dropped into a receiving tank called acrystalliser where it is cooled down and the crystals continue to grow. This
  19. 19. also releases the pan for a new boiling. From the crystalliser themassecuite is fed to the centrifuges.In a raw sugar factory it is normal to conduct three boilings. The first or "A"boiling produces the best sugar which is sent to store. The "B" boiling takeslonger and the retention time in the crystalliser is also longer if areasonable crystal size is to be achieved. Some factories re-melt the Bsugar to provide part of the A boiling feedstock, others use the crystals asseed for the A boilings and others mix the B sugar with the A sugar for sale.The "C" boiling takes proportionally longer than the B boiling andconsiderably longer to crystallise. The sugar is usually used as seed for Bboilings and the rest is re-melted.Various boilers which are used here in L.H.S.F. are:THERMAX BOILER CAPACITY : 45 TPH WORK PRESSURE : 21 Kg/cm square STEAM TEMRERATURE : 340 deg C HEATING SURFACE : 2204 m square INSTALLATION YEAR : 1991LIPI BOILER CAPACITY : 20 TPH WORK PRESSURE : 21 Kg/cm square STEAM TEMRERATURE : 345 deg C HEATING SURFACE : 1026 m square INSTALLATION YEAR : 1998WIL BOILER CAPACITY : 45 TPH WORK PRESSURE : 45 Kg/cm square STEAM TEMRERATURE : 445 deg C HEATING SURFACE : 2106 m square INSTALLATION YEAR : 2001
  20. 20. SISTON BOILER CAPACITY : 120 TPH WORK PRESSURE : 67 Kg/cm square STEAM TEMRERATURE : 525 deg C HEATING SURFACE : 5359 m square INSTALLATION YEAR : 2007The Energy AspectsThe steam is raised in bagasse fired boilers which usually have asecondary fuel to accommodate imbalances in bagasse supplyand steam or power demand. The factory designer attempts tobalance the site such that bagasse is neither left over norinsufficient: any secondary fuel costs money and a large surplusof bagasse may cost money to dispose. Balancing is done byselecting the right mix of turbine and electric drives for majorequipment and selecting the pressure of the steam to give theefficiency required. In many cases this does not recognise the fullenergy value of the bagasse and is therefore wasteful in anoverall sense. Today, more and more factories are consideringpower export as another by-product of sugar production. To dothis they are improving the efficiency of their thermodynamiccycles and converting equipment drives to optimise power output.Factories are frequently in very undeveloped places and have noconnection to an external power supply. This requires specialtechniques to start the factory and means that any breakdown inthe power house impacts on the entire neighbourhood. Wivessoon tell their husbands what happened to dinner when theirspouses lost power!Sucrose extraction from beets is easier than with cane for severalreasons of which keeping quality and diffusion characteristics arethe two most important.
  21. 21. Stored correctly, beet will keep for several weeks after harvestingwithout substantial loss of sucrose content. It is generallyharvested or stored on the farm and delivered to the factory up to48 hours before harvesting. In countries with very cold winters,however, this can be a much longer time with large ventilatedpiles kept at the factory to avoid process disruptions caused by aninability to harvest or transport the crop. The beets needprotection from frost and from overheating in the piles but as abiennial plant it expects to survive over winter in order to come tolife in spring and grow to seed.Unlike cane extraction, it is important to avoid rupturing the cellsof the beet because the sucrose is readily diffused out of wholecells and extraction can therefore be achieved preferentially. Thisresults in a high purity juice without a lot of the cell material andother non-sugars found in cane juice. The slicing is thereforedone with sharp knives which cut a V section slice of 4 to 5 mmthickness. The slices, known as cossets in some parts of theworld, look somewhat like "potato sticks".A typical raw juice from diffusion will contain perhaps 14% sugarand the residual pulp will contain 1 to 2% and a total of 8 to 12%solids.PressingThe spent slices are de-sweetened in large screw presses wherea variable pitch screw pushes the pulp at ever increasingpressure through a perforated, usually conical tube. The juiceflows away and the pressed pulp, at around 70% moisturecontent, discharges from the end of the tube. Molasses is oftenadded to the pressed pulp before drying in order to provide ahigher sugar content animal feed. Typically 2 tons of pressed pulpand 0.4 tons of molasses are dried to make 1 ton of dried pulp at10% moisture content. The dried pulp is then extruded into pellets
  22. 22. to increase the density of the product and make it easier to storeand handle.The drying process is energy intensive, using about 1/3 of thetotal factory fuel consumption. Generally driers are large rotatingdrums with air at 600 to 900 °C used to drive the water out of thepulp. Some new driers use steam so that the water driven off canbe used as heat in the sugar manufacturing process.CarbonatationCarbonatation is achieved by adding milk of lime [calciumhydroxide, Ca(OH)2] to the liquor and bubbling carbon dioxidethrough the mixture. The gas, which is obtained from themanufacture of the lime in the first place, reacts with the lime toform fine crystalline particles of calcium carbonate which occludethe solids. To obtain a stable floc, the pH and temperature of thereaction are carefully controlled. Beet factories use much morelime than cane factories, some 1 to 3% of CaO on beet is used.The filtration is undertaken with rotary leaf filters where the liquoris pumped from the outside of the leaf to the middle where theclear liquor is collected or in a clarifier where settling occurs. Asthe layer of floc builds up in a leaf filter it increase the pressuredrop across the system until the filter is effectively choked andtaken off line for cleaning. The clarifier is run continuouslyhowever. The lime mud that is collected from either method is stillwet with sugar liquor so it is de-sweetened by slurrying with water- the resultant sweet water is used elsewhere in the process - andre-filtering it to a mud with 50% or less moisture. The mud is thendumped or used as lime on fields.The efficiency of the factory depends substantially on the use ofmultiple effect evaporation, as with the raw cane sugar factory. Itis even more important for the beet factory because there is nosurplus fibre available to porvide fuel for the power house. The
  23. 23. greater the number of effects, the less steam is required to drivethe first effect. Each subsequent effect is heated by the vapourfrom the previous effect so has to be operated at a lowertemperature and therefore lower pressure. In is not unusual tosee 6 and sometimes 7 effects in a beet factory although manycane factories only have 3 or 4 effects.DecolourisationGranular activated carbon is the modern equivalent of "bonechar", a carbon granule made from animal bones. Todays carbonis made by specially processing mineral carbon to give a granulewhich is highly active but also very robust: it can withstand themechanical abrasion that results from transporting it around theplant.The carbon is used in the process in very large columns, perhaps10 or more metres high. The sugar liquor, at about 65% drysolids, is pumped through 2 columns in series. Because oflimitations in distributing the liquor across the width of largecolumns it is quite normal to split the total liquor flow into three ormore parallel streams, each of which passes through a pair ofcolumns. The first column of the pair has been in use for sometime while the second column is fresher. When the carbon in thefirst column reaches is practical limit of absorption, that column isswitched out of line, the second column becomes the first columnand a column with fresh carbon becomes the second column. In atypical refinery with say 3 streams of liquor, a column will come offline every three days so any one column has a life of 18 days ofwhich 9 are hard working in the first column position.Decolourisation with granular activated carbon typically achieves90% effectiveness: a 1200 colour liquor entering the system willdepart at about 120 colour.
  24. 24. MILLHOUSE:Mill house is the cane crushing unit which consists of cane carrier,cane cutter having cutting knives, milling tandem, bagasse carrierand conveyor. Cane feeding to the cane carrier is done byunloaders and feeder table. As the cane carrier moves, the canekicker evens out cane load in the cane carrier and then two setsof cane knives cut the cane into small pieces. This process ofcane cutting is called cane preparation. These cane pieces then,pass through different mills and the juice is extracted. The millsare driven by D.C.motors. The residue which comes out of the millafter extraction of juice is called bagasse.Various milling units used in LHSF are :-  Mill GRPF 500kwatt d.c., 1000kw d.c.  Mill GRPF 522kwatt dc. o 900kwatt variable frequency drive  Mill GRPF hydraulic drive 900kwatt v.f.d.  Mill GRPF 400h.p hydraulic drive o 900kwatt v.f.d  Mill GRPF 500kwatt v.f.d o 900kwatt v.BOILERHOUSE:Boiler generates steam by burning the bagasse. The steam isused in powerhouse, boiling house, curing house. The steamrequired by the Sulphitation process varies from 42 - 45 % oncane crushed per hour.POWERHOUSE:The high pressure steam generated by the boiler is utilized forproduction of power by the turbo-alternators. The power producedis used for captive needs and the surplus power is exported to thegovernment grid. The low pressure steam that comes out from theturbo alternator is utilized for boiling the extracted juice.
  25. 25. CLARIFICATION AND BOILING HOUSE:The juice extracted by the mills is measured by juice flow system. Themeasured juice is heated in juice heater in two stages. First the juiceis heated by the vapours from fourth and third bodies of evaporator indifferent heaters. This heating is called primary heating. The heatedjuice is treated with milk of lime and sulphur-di-oxide to coagulatemaximum impurities and sent for secondary heating. The secondaryheating is done with vapours from second body of evaporator andvapours from the first body or exhaust steam. The treated juice ispassed to clarifier, where in clear juice is removed from the top andsettled mud at the bottom is separated. To extract sugar from themud, it is taken to vacuum filter in which juice and filter cake areseparated. Juice is taken back to process and the mud is disposed assolid waste. Clear juice from clarifier is taken to evaporator forevaporating its water content. First body is heated by exhaust steam,and other bodies by the vapours of the previous body. The total waterevaporated in the evaporator is 75-80 % percent. The juice afterevaporation is called as syrup. This syrup is normally of 60 % solidsof its total weight. The syrup is then sulphited in syrup Sulphitationtower.BOILING AND CURING HOUSESulphited syrup is taken to pan floor for making sugar crystal. Threemassecuites boiling systems is normally adopted, in which, A, B and CMassecuites are boiled. A-massecuites is formed by boiling syrup, sugarmelt ,„A‟ light molasses and on „B‟-single cured sugar as seed. This A-Massecuite is boiled till it attains the required size of sugar crystal and it isdropped into crystallizers and cooled. After exhaustion of sugar in solution,the „A‟ massecuite is passed on to the centrifugals for separating sugarcrystals from the massecuite. The separated A sugar is bagged afterdrying.„A‟-Light and „A‟-Heavy molasses are pumped to pan floor and areused for making „A‟- and „B‟-Massecuite respectively„B‟-Massecuite boiled in „B‟ pans is dropped into B- Crystallizers and then itis cured in „B‟-Centrifugal machines. „B‟-heavy molasses and „B‟-singlecured sugar are obtained separately. „B‟-single cured sugar is used as seedfor A massecuite. „B‟-heavy molasses is used for making „C‟-Massecuite in
  26. 26. C-pans. „C‟-Massecuite is dropped into „C‟-Crystallizers where it is cooled.„C‟-Massecuite is then taken to „C‟-fore worker centrifugal machines forcuring. Final molasses and „C‟-single cured sugar are obtained. C Singlecured sugar is again cured in another centrifugal machine in which „C‟-double cured sugar and „C‟-light molasses are obtained. „C‟-light molassesare taken to pan floor and is used in making „C‟-Massecuite. „C‟-doublecured sugar is melted and is used in making A Massecuite.Sugar discharged from A Machine is dropped on to grass hopperconveyors. By passing hot air in hoppers the sugar is dried and taken tograder in which powder and rori‟s are separated. The required grade sugaris bagged.COGENERATION POWERCogeneration involves the use of high pressure Boilers for producing steamand Turbo generators for generating power. The high pressure steampasses through the turbine and generates power. The low pressure steamfrom the turbine is used in the processing of sugar. This process ofutilization of steam for generating power and for processing of sugar iscalled cogeneration. This cogeneration plant is the first plant in India to install Air cooledcondensers instead of water cooled condensers for its turbines. Eventhough the Air cooled condensers incur a much higher investment cost than
  27. 27. the water cooled condensers, it is environment friendly and they totallyeliminate the use of water. This is an important environment feature giventhe scarcity of water in the region and a positive step towards waterconservation.MOLASSESThe history of the Word „molasses‟ ( „Melasse‟ in German and Dutch) is notmentioned in Etymological dictionaries since it is quite definitely and clearlyderived from the Romanic languages.The term „molasses‟ is applied to the final effluent obtained in thepreparation of sugar by repeated crystallization.The amount of molassesobtained and its quality (composition) provide information about the natureof the beets (local conditions of growth and effects of the weather) and theprocessing in the sugar factory, such as the efficiency of the juiceclarification, the method of crystallization during boiling, and the separationof the sugar crystals from the low-grade massecuite.If the concept molasses is to be strictly defined it is necessary to distinguishbetween theoretical and practical molasses. The theoretically finalmolasses is a mixture of sugar, nonsugars and water, from which nosaccharose crystallizes under any conceivable physical and technicallyoptimum conditions, with no regard to time. If relatively more favourableconditions for crystallization are maintained (low water content, lowtemperature, long crystallization time, thin layers of the syrup film) thecrystallization might be so extended that with intensive centrifugation of themolasses a quotient (Q) of 49 would be attainable. Q represents thepercentage of sugar in the total solid content of the molasses.The lower the purity or purity coefficient, the more closely a syrupapproaches theoretical molasses. Unusual specimens of molasses,produced in experimental studies, have quotients from 45 to 50. Thepractically obtainable molasses is the end syrup from which, withmaintenance of the technical conditions promoting crystallization, nosignificant additional amounts of saccharose can be recovered by furtherconcentration. In this sense molasses with purity quotients above 64 are nolonger true molasses they are crystallisable syrups.The objective of the sugar industry is to produce molasses whose purity isas low as possible. Commercial molasses ordinarily have a quotient around60, i.e. approximately 48 % sugar is present in molasses whose solids
  28. 28. content is 80%. (Q denotes purity quotient of molasses; S is sugar content;T represents dry substance.) Efforts to understand and master theconditions leading to exhausted molasses are as old as the sugar industryitself. Since the formation of molasses and the problems of crystallization ofsugar are closely related, a clear understanding of the influences of thenonsugar substances on the crystallization of the saccharose from aqueoussolutions simplifies the study of the formation of molasses. The manystudies along these lines can be divided fundamentally into two categories.(i) Mechanical theory of molasses formationThis old theory is based on the decrease in the rate of crystallization whichdepends on the speed with which the dissolved sugar molecules aretransported out of the liquid on to the crystal surface as well as on the rateat which they are built into the crystal lattice.(ii) Chemical theory of molasses formationThis theory is based on the mutual solubility influences in the system: watersugar, salts or non sugar components. In many studies of the influence ofthe non sugar components on the solubility of sucrose, pure substances ormixtures of pure substances have been employed, but they did not alwayscorrespond to the complicated relationships prevailing in molasses. Theuse of ion exchangers made it possible to start these investigations directlyon molasses. It has been found that nitrogenous materials have practicallyno effect with respect to the sucrose solubility; potassium and sodium haveconsiderably stronger molasses-producing properties than calcium andlithium. Because of the economic significance of the composition of finalmolasses there is great permanent interest in the sugar industry in beingable to calculate beforehand the amount of molasses that may beexpected, i.e. at the time of delivery and processing of the beets.
  29. 29. Molasses is a viscous by-product of the processing of sugar cane, grapesor sugar beets into sugar. The word molasses comes from the Portugueseword melaço, which ultimately comes from mel, the Latin word for"honey".[1] The quality of molasses depends on the maturity of the sugarcane or sugar beet, the amount of sugar extracted, and the method ofextraction. Sweet sorghum syrup is known in some parts of the UnitedStates as molasses, though it is not true molasses.
  30. 30. CHALLENGES FOR SUGAR INDUSTRYIndia ranks first in sugar consumption and second in sugar production inworld but its share in global sugar trade is below 3%. Indian sugar industryhas been facing raw material, and resource as well as infrastructuralproblems. Globalization has brought a number of opportunities but at thesame time posed certain challenges before sugar industry. Most of sugarunits in India utilize production capacity below 50%. Low capacity utilizationand inadequacy of raw material led to closer of 100 sugar factories in India.Mounting losses and decreasing networth of sugar factories have beenresponsible for sickness of sugar industry. Sickness in sugar industry hasreached to an alarming proportion. Indian sugar industry has been cashstriven for decades. Low cash inflow due to piling stocks leads to seriousfinancial crisis and finally to closing sugar factories.Sugar prices have been a political issue rather than economical issue.Many a times it worsens economy of sugar factories. The main concern ofsugar industry in India is fluctuations in sugarcane production due toinadquate irrigation facilities, lower sugarcane yield, and frequent droughtsin tropical and sub-tropical areas where sugarcane is grown ona largescale. In addition, sugarcane yield has been lower (59 Mts per hectare).Sugar recovery is also lower in comparison with other sugar manufacturingcountries. This leads to escalation of production costs and weaknesscompetitive edge of the industry. Most of sugar mills in India are havingdaily sugarcane crushing capacity of 1250 tonnes. These mills cannot haveeconomies of scale so they have to incur high production costs. Indiansugar industry is characterized by high production costs. Therefore, dailycrushing capacity should be extended to 2500 tonnes. Obviously, industryhas a great challenge of existence in global market. In recent years,sugarcane production in India has decelerated to a great extent due towater and power shortage. Special attention is needed to be given onwater resource management. All the area under sugar cultivation should bebrought under drip irrigation to conserve water as well as fertilizers.Adequate and regular power supply to sugarcane growers and sugarfactories would increase production andproductivity. To enhance share ofIndian sugar industry in global trade, quality and quantity of sugar needs tobe enhanced.
  31. 31. CONCLUSION & SUGGESTIONSSugar industry is the second largest agro-based industry in India. Sugarfactories, particularly cooperative sugar factories in Maharastra and otherstates have been instrumental in building confidence among rural peopleand strengthening industrial base in rural India. In the era of globalization,sugra industry needs more competitive edge which can be given by way ofmodernization, enhancing productivity, and manufacturing excellent qualitysugar at competitive prices. It needs quality management at every level ofactivity to enhance its performance. The need of the hour is to liberalizeindustry from clutches of unprofessional people. Most of the sugar units donot have byproduct utilization plants. Projects based on bagasses andmolasses should be initiated. Ethanol, alochol, and paper projects havetremendous scope for development in India. In future, 10-15% ethanol maybe allowed to be blended with petrol. Bagasses based power generationprojects installed adjacent to each sugar factory would fulfill need of power.Research programme should be undertaken in area of sugarcanecultivation, enhancing sugarcane productivity, and sugar recovery.Sugarcane prices should be fixed on basis of sugar recovery. Attention is tobe given on manufacturing quality sugar as per international standards atcompetitive prices.