In the production of sugar cane juice many steps are taken to receive various byproducts, most importantly sugar.
- First the sugar cane is harvested, thoroughly washed and sent to the shredder. During the shredding process the cane is passed through a series of rotating blades that cause it to be reduced to small pieces. In this form the juice is much easier to be extracted.
- After shredding the shredded cane is sent to be crushed. During this process the shredded cane is passed through two large cylindrical metal tubes that crush the cane allowing the juice to be squeezed out, leaving behind the bagasse (which is the dry pulp left behind after cane juice is extracted).
- After crushing the cane juice is of a dark color, it needs to be clarified which removes all impurities allowing for the juice to be much cleaner and lighter in color. A thickener is added to the juice that allows for the impurities to clump together and rise to the top and a separating funnel is used to collect clarified juice. However, depending on the types of sugar needed the clarification process differs. For example, when brown sugar is needed, the sugar cane juice is just boiled but when granulated sugar is needed, the sugar cane juice is put through a process where the juice is boiled with other materials such as powdered lime (used in some places not all) and the mixture turns to a slight yellow color, which is left to stand and the juice at the bottom is separated using a large scale separating funnel.
- Preliminary Filtration: Initially, the heated juice might pass through coarse filters or screens to remove larger particles like pieces of plant material, soil, and other debris. This step removes the bulk of the solid impurities.
- Fine Filtration: The juice then undergoes finer filtration processes, often using filter presses or filter beds made of materials like activated carbon, diatomaceous earth, or cloth. These filters are capable of capturing smaller suspended solids, tiny particles, and other impurities that may remain in the juice after the preliminary filtration.
- After clarification, the resulting clear juice is quite dilute, containing a relatively low concentration of sugar. Evaporation is used to concentrate the sugar solution. The juice is heated in evaporators, which are large vessels designed to heat the liquid and facilitate the evaporation of water. Evaporation is vital in this process as it helps remove excess water, concentrating the sugar solution to a level where further processing can yield crystallized sugar.
- The concentrated syrup is then seeded with tiny sugar crystals or nuclei. The supersaturated solution is cooled down slowly, encouraging the sugar molecules to come together and form larger crystals around the nuclei. Crystallization is a crucial step because it helps purify the sugar by separating it from other substances present in the cane juice. The controlled formation of crystals allows for the isolation of pure sugar crystals, which are then processed further to obtain the refined sugar we commonly use.
- After the sugar is crystallized it is separated from the remaining liquid using centrifugation. The sugar crystals are spun at high speeds within a centrifuge machine. The spinning forces cause the crystal to be pressed into the edges of a centrifuge basket, while molasses is expelled through openings in the basket. This separation process leaves behind sugar with relatively low molasses content. Once separated the sugar crystals are washed with water to remove any wanted molasses on the surface.
-The damp sugar crystals are dried in large, hot air dryers, reaching a moisture content of as low as 0.02%. Next, the sugar is gently tumbled through heated air in a granulator. The dried crystals are then separated into different sizes through vibrating screens and placed into storage bins. Finally, the sugar is packaged for the consumer.