Sugar, one of the main ingredients in a common man’s daily diet, is made through a long process involving crushing, clarification and crystallization. It is made predominantly using sugarcane. Sugar beet is also one of the alternatives. The manufacturing process of sugar has evolved over the years, with new technology it has been made more efficient. But the essence of the process of juicing the sugar cane or beet and clarifying it before crystallization remains the same.
Sugar manufacturing can be explained in the following steps:
Post harvesting, as soon as the canes or beets arrive at the plant they are cleaned. It can be either by placing them in rotating drums or on conveyor belts and spraying water on them. It is critical to remove mud or any other kind of unwanted material before juicing.
This step involves breaking the cane’s hard structure and extracting the juice from it.
In most cases, shredders or revolving knives are used along with three roller mills. Once the cane is processed in one conveyor belt it is passed on to the other through conveyor belts to extract more juice. But water is sprinkled before doing so to extract more juice. The cane waste removed in the end after milling is called bagasse.
The process involves removing impurities from the sugar cane or sugar beet juice. It is mostly done by adding lime to it to neutralise the organic acids present in it. The solution is later heated up to 95℃. The heating helps in coagulation and the impurities settle in the bottom, which is then removed.
The water in the juice needs to be reduced. The solution is evaporated to achieve the same. In this step, almost two-thirds of water is removed. The solution is passed through a multiple-effect evaporator. Close to 2/3rd of water is removed through this process. They are passed through a multiple-effect evaporator. The multi-effect evaporator is a series of usually five evaporators.
There is a need to further reduce the water content so that sugar crystals are formed. The solution is further heated in vacuum pans until it reaches supersaturation. They are then moved from the pan to the crystallization tank. Meanwhile, some small grains of sugar are also added, so that they can act as nuclei for crystal formation. It is known as seeding.
Separation of crystals:
The crystals are separated and the leftover material is called molasses, which is a by-product of the manufacturing process. Centrifugal force is used to remove them and they are dried by passing them through a hot pipe.
Before sending the sugar to the market for sale, in most cases, it is refined. Refining involves removing further impurities. The process of sugar making is thus heavily driven by crushing the sugar cane or sugar beet, removing impurities and water and forming crystals.