AUSTRIAN EXPERIENCE IN PRODUCING SUGAR FROM UNPURIFIED BEET JUICE

This paper summarises experience in Austria of sugar manufacture from unpurified raw juice. Part one gives the results of a project on combi ned production of white sugar and ethanol, The idea was to concentrate raw juice, followed by crystallisation (evaporation crystallisation), The run-off was intended for alcohol production, whereas the sugar co ncentrate was processed to white sugar, The concentration of raw juice was initially impeded by scale formation on the evaporator tubes but this was improved by adding small amounts of soluble Ca salts. The ''r aw juice sugar'' obtained from the concentrate showed purities of 97-9 8, but was turbid, Liming and carbonatation of the dissolved sugar gav e melted liquors from which white sugar could be crystallised, The fil terability depended largely on the quality of the raw juice sugar. Par t two describes the production of ''Vollzucker'' (whole sugar) from un purified beet juices, The scaling problem was overcome by employing a special evaporator type a metallic particle fluidized bed with flash e vaporation, The syrup thus obtained has a shelf life of years, provide d a certain dry substance range is kept and the headspace is filled wi th protective gas, A free flowing product can be obtained by spray dry ing, but for this the content of glucose and fructose must not exceed certain limits.