Sugar Production from Sugar Cane
Practical Action
It is common for four vessels to be used in series, each subjected to a progressively higher
vacuum. This system is capital-intensive but is highly energy efficient and more importantly
boils the juice at progressively lower temperatures from 103 to 50ºC, reducing the effects of
inversion, minimising discoloration and enhancing the formation of sugar crystals.
Final boiling to over 95º Brix takes place under vacuum in a single vessel, known as the vacuum
pan, which is designed to handle the viscous massecuite. During this stage crystallisation begins
in a controlled manner, enabling the maximum yield of crystals to be developed before the
massecuite is transferred to the crystallisers.
Bagasse is used to fuel highly efficient high-pressure steam boilers. The high-pressure steam is
used to generate electricity to meet the VP plant's needs and the low pressure exhaust steam is
then used to boil the juice in the vacuum pans.
Crystallisation
The massecuite is cooled and the crystallisation process completed using large vessels that stir
the massecuite continually for up to 48 hours.
Centrifuging
Takes place on a batch basis using large centrifuges similar in design and operation to those
used in the OPS process.
Drying and packaging
Drying is carried out at low temperatures using rotary or fluidised bed driers.
Setting up a sugar factory
Types of sugar factory
Service extraction
All is required is a site for the crusher and a space to build the furnace. Farmers, growers and
merchants provide the raw material for processing and packaging. They take the risk of poor
preparation and problems associated with inadequate storage and packaging. The processors
charge a rate per unit of cane crushed or juice processed payable either in cash or percentage of
the output or both.
The farmers can then rent the furnace or build their own close to the crusher site and produce
syrup or jaggery, keeping control of the quality of the product. They could return to the farm and
process the juice there or could pay others to process the juice for them.
This type of system is relatively low-cost and is suited to small scale production of up to 50 TCD
in areas where cane is grown during short seasons on small plots spread out over a wide area.
Independent sugar factory
The factory buys in sugar cane and is then responsible for all aspects of preparation, processing
and marketing the product. This type of business needs a reliable and constant supply of cane
of acceptable quality. Although the factory could grow its own cane it is more usual for it to buy
in cane from various sources including:
direct from individual farmers/growers
agricultural co-operatives or groups
private traders or companies
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