Brownsugarexporter.com -
Whether the base is sugar cane or beets, the sugar extraction and
refining process of which molasses is a byproduct is a circular path of washing
and heating the cane and beets with hot water.
Washing
and cutting
- The sugar cane stalks are loaded onto conveyer belts and subjected to hot water sprays to remove dirt and other field debris. Then, they are passed under rotating knife blades that cut the stalk into short pieces or shreds.
Beet roots
are loaded into a tunnel-like machine called a flume, in which leaves, weeds,
and rocks are separated out. A pump pushes the beets into a washer fitted with
a large shaft that moves the beets through the water to remove any remaining
dirt. The beets move through a slicer that cuts the beet roots into thin strips
called cossettes.
Extracting
the sugar juice
- In the sugar cane processing plant, extraction can be accomplished in one of two ways: diffusion or milling. By the diffusion method, the cut stalks are dissolved in hot water or lime juice. In the milling process, the stalks are passed under several successive heavy rollers, which squeeze the juice out of the cane pulps. Water is sprayed throughout the process to facilitate the dissolving of the juice.
In the
sugar beet factory, the sliced beet roots, or cossettes, are loaded into
cylindrical diffusers that wash the beet juice out with the aid of hot water.
The discarded beet juice is used to pre-scald cossettes in the mixer so that
they absorb even more of the sugar.
Clarifying
the juice
- The extracted juice is clarified by adding milk of lime and carbon dioxide. The juice is piped into a decanter, heated and mixed with lime. The juice passes through carbon filters, producing a mud-like substance. Called carb juice, this mud is pumped through a heaterand then to a clarifying machine. Here the mud settles to the bottom and the clear juice is piped to yet another heater and treated again with carbon dioxide. Once again the mud is filtered out, leaving a pale yellow liquid called thin juice.
Evaporating
and concentrating the syrup
- The juice is pumped into an evaporator that boils the juice until the water dissipates and the syrup remains. The syrup is concentrated through several stages of vacuum boiling, a low temperature boil to avoid scorching the syrup. Eventually, the sugar crystallizes out of the syrup, creating a substance called massecuite. The massecuite is poured into a centrifuge to further separate the raw sugar crystals from the syrup. In the centrifuge, the sugar crystals fall away from the syrup that is being spun at a significant force. This remaining syrup is molasses, and it is forced out through holes in the centrifuge.
Storage
and boffling
- The molasses is piped to large storage tanks. It is then pumped, as needed, to the bottling machine where pre-measured amounts of molasses are poured into bottles moving along a conveyer belt.
Byproducts/Waste
In
addition to molasses, which is itself a byproduct of the processing of sugar
cane, there are several others materials that are used for other purposes.
After pressing the juice out of the cane stalks, the dry stalk residue, called
bagasse, are used as fuel in the plant. Beet pulp is used in the processing of
pet foods. Cane wax, which is extracted from the dry residue, is used in the
manufacture of cosmetics, polish, and paper coatings.(BD)