Sugar manufacturing process

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Sugar Introduction, Raw and Refined

Sugar, Factors Affecting Sugar

Storage

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INTRODUCTION

Sugar

• General term indicating sweet carbohydrates

• Mono-, di- and poly-saccharides

• Obtained from plants, largely sugarcane & sugar

beet plant

• Pakistan 12th largest producer of sugar

• Per capita consumption of sugar is 25kg

• More than 81 sugar mills in Pakistan

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Harvesting Of Sugarcane• Fully mature

• Two types

– Manual

– Mechanical

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FLOW DIAGRAM

transportation

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Transport and Handling

• Animal driven carts

• Trolleys

• Trucks

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FLOW DIAGRAM

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Material Handling and Storage

• Stored in cane yards

• Carried from cane yard to feeding area by

– hook/chain

– Cranes

– Reelings

– Conveyer belt

– Carry

– Huge suction truck

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Washing

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Cutting of Canes

• To aid the cane crushing

• Cane knives to cut cane into small pieces

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FLOW DIAGRAM

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Shredding

• To remove leaves and nodes

• Hammer mill shredder

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CRUSHING

• Cane crushed to break hard structure

• Cells containing juice are ruptured

• No juice extracted

• Increase efficiency of juice extraction

• Subjected to crusher with corrugated blades

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FLOW DIAGRAM

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MILLING TANDEMS

• 3 roller mills

connected in series

– Top roller

– Feed roller

– Discharge roller

• 5-7 in number

• Extract the juice from

crushed cane

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PRODUCTS OF MILLS

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FLOW DIAGRAM

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USE OF BAGASSE

• Stored in bagasse storage

• Used as fuel to generate steam

• Steam used for

– Generating electricity

– Evaporation of juice before crystallization

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FLOW DIAGRAM

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CLARIFICATION/DEFECATION

• To remove non-sugars and impurities

– Liming

– Sulphitation

– Phosphatation

– Carbonation

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FLOW DIAGRAM

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FILTRATION

• Mud from

clarifier still

contain some

residual juice

• Filtered to

extract residual

juice in Rotary

Vacuum Filters

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FLOW DIAGRAM

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EVAPORATION

• Juice evaporated to obtain super saturated solution

• Increase concentration of juice from 15ᴼ brixto 65ᴼ brix

• Juice preheated to

around 107-110ᴼC

• Two types of evaporators

– Single effect evaporators

– Multiple effect evaporators

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MULTI-EFFECT

EVAPORATOR

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CONT…

• Steam used to evaporate juice

• 1 liter steam to evaporate 4 liter juice

• Steam temperature 113-130ᴼC at 1st pan and

55ᴼC at last pan

• Each subsequent vessel with decreasing pressure

• Last pan being under almost a total vacuum

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FLOW DIAGRAM

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CRYSTALLIZATION

• Carried out in single effect high-vacuum boiling

pans

• Brix are increased from 65ᴼ to 75ᴼ by boiling at

60ᴼC

• Three stages of crystallization

– Nucleation

– Initiation

– elongation

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CONT…

• Massecuite

– mixture of crystals and mother

liquor (molasses) resulting from the

crystallization

• Transferred to crystallizer

at low temprature

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FLOW DIAGRAM

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CENTRIFUGATION

• Separate sugar from molasses

• Centrifuge operates at 100-1800 rpm

• Molasses pass through perforations

• Sugar crystals are

washed with 85ᴼC water

• Raw sugar and molasses

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FLOW DIAGRAM

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DRYING AND PACKAGING

• Sugar tumbled through

large cylindrical dryers

• Sorting

• Packaging

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RECEIVING AND STORAGE

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AFFINATION

• Mixture of raw sugar with high purity syrup

(85%) called magma

• Melts outermost layer of the raw sugar crystal at

50ᴼC

• Centrifugation to remove resulting syrup from

melting of the outer layer

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MELTING

• Affinated sugar dissolved

with hot condensate to

conc. of 72ᴼ brix

• Melted at 85ᴼC in Batch or

continuous melter

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PURIFICATION

• Remelt may contain some impurities and

colorants

• Liming

1. Partial 2. Complete

• Carbonization

• Colorants remover by decolorization

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DECOLORIZATION

• Two methods

1. Granular activated carbon (GAC)

2. Ion exchange resine

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EVAPORATION &

CRYSTALLIZATION • Sugar syrup evaporated up to super saturation

• Crystallization

• Centrifugation to obtain refined sugar crystals

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DRYING AND STORAGE

• Bucket elevator on conveyer

• Hot air for drying

• Sieving

– Fine, medium and bold grains

• Storage in godowns

– Cool, dry, moisture and odor free

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PACKAGING

• Containers opaque, airtight, moisture/odor proof

• Glass canning jars or cans for liquid sugars

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RAW & REFINED SUGAR

• Raw sugar

• Obtained directly from sugarcane juice without

refining

• Most natural sugar

• Brown in color due to molasses

• Refined sugar

• Have white luster and transparent

• Bleached to remove color and other impurities

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FACTORS AFFECTING

SUGAR STORAGE• Temperature

• Moisture

• Quality of sugar

• Light

• Grain size and distribution

• Compression

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