SUGAR BEET PROCESSING
Sugar beets of the Beta vulgaris species have a white inner flesh and look more like a large parsnip than a red beet. The sugar beet crop is planted in early spring and harvested in the fall, when it is at maximum sugar content. To grow beets, a farmer signs a contract with a company to plant a certain amount of acreage; usually payment is made by the company on the basis of the sugar content of the beets and also the price of refined sugar sold by the company. Many U.S. sugar companies today are owned by cooperatives made up of beet growers.
Harvesting machines uproot the beets, cut off the tops, and then convey the beets into a truck. The beets are delivered to the factories and receiving stations, where they are dumped either directly into the process or stored in large piles for later use. The sugar factory operates round the clock and must be fed a continuous supply of beets once the "campaign," or processing season, gets under way. Campaign length is usually from 120 to 150 days and even longer in the northern regions.
Upon entering the factory, the beets are washed and sliced into long thin strips called "cossettes." The cossettes then enter the diffuser, where water carries away the sugar in the form of raw juice. The exhausted beet material, called "pulp," goes to the dryer or silo to be sold as livestock feed. After leaving the diffuser, the raw juice is purified with lime and then put through two stages of carbonation in which carbon dioxide gas is added to precipitate the lime and nonsugars. The juice then passes through several filtration steps to remove impurities. This purified juice, called "thin juice," then goes to the evaporators to be concentrated into "thick juice." It is then filtered again to assure purity.
The pure thick juice then enters crystallization, where there are typically three stages: white pan, high raw pan, and low raw pan. The syrups arrive at the vacuum pans, where the liquid is boiled into a thick supersaturated liquid. At just the exact moment in the boiling stage, the sugar boiler initiates the crystal formation by "seeding" the pan with an extremely fine sugar slurry. The sugar crystals are grown to the proper size, then the mass of sugar crystals is dropped to centrifugal machines to be spun at high speed. The liquid portion, or "mother liquor," is separated from the sugar crystals and saved for further crystallization and sugar removal. The liquid from the final boiling is exhausted of sugar and is called molasses. The molasses is saved for further desugarization and sold as an animal feed by-product.
The final white sugar is centrifuged from the white pan mass and washed. The damp sugar crystals are then sent to the sugar granulator for drying. From the granulator, the sugar goes to packaging, truck, or rail loading or is stored in huge storage silos. It requires approximately forty pounds of sugar beets to produce a five-pound bag of granulated sugar.
In the crop year 2000 more than 32 million tons of beets were harvested in the United States in twelve states. The major sugar beet growing area is the Red River Valley, which straddles the boundary of Minnesota and North Dakota. Nearly half of all the sugar beets grown in the United States come from this area. Among other Plains states, Montana, Colorado, Wyoming, and Nebraska all produce more than one million tons of sugar beets. During the 2000 production year there was a total of ten sugar beet companies in the United States, with a total of twenty-eight operating factories. Of these factories, thirteen are in the Great Plains region. They are located in the states of Colorado, Nebraska, Wyoming, Montana, and North Dakota. The beet sugar companies of the Great Plains include Western Sugar Company, Holly Sugar Corporation, American Crystal Sugar Company, Minn-Dak Farmers Co-op, and Rogers Sugar. There are two sugar beet growing areas in Canada, located in Ontario and Alberta. Canada has one sugar beet factory, located in Taber, Alberta, that annually contributes approximately 10 percent of Canada's total refined sugar production. Despite the above-noted production, the United States and Canada are net importers of sugar.
See also AGRICULTURE: Sugar Beets.
Richard Reisig Western Sugar Company