AMS on the Sugar Industry and BAT pH:
Sugar is produced in 127 countries. Sugar cane and sugar beets are cultivated on an area of approx. 25m hectares worldwide with a sugar production of approx. 120m tons. Cane sugar accounts for the major part (2/3) of the sugar produced, with beet sugar comprising the rest. The major sugar-producing countries are: India (> 12 Mio t), former USSR, Cuba, Brazil, USA, China, France, Australia, Thailand, Mexico, Germany (4 Mio t), Turkey, Italy.
Sugar cane and sugar beet contain up to 20 % sugar (chemical: saccharose). Whether sugar cane or sugar beet serve as source material is distinguished only by different production processes in the beginning, during delivery and cutting, and by different washing procedures. The shredded pieces are leached with 70 °C hot water in the diffusion tower or in the milling train.
The raw juice produced contains almost 99% of the original sugar, plus various organic and inorganic constituents, the so-called non-sugar particles. The juice is purified using lime and carbonic acid via lime kilns where lime stone (calcium carbonate) is heated to produce burnt lime (calcium oxide) and carbon dioxide.
CaCO3 + heat CaO + CO2
The lime is added to the raw juice as lime milk. In the process, loose calcium hydroxide precipitates are formed which bind the non-sugar particles.
CaO + H2O Ca(OH)2
Now, the carbon dioxide is led into this mixture. The lime including the nonsugar particles stably precipitates and can be separated by filtration.
Ca(OH)2 + CO2 CaCO3 + H2O
This step is called carbonation. It is repeated in a second stage. A clear, light-yellow thin juice with a sugar content of approx. 16% remains, which is further processed for thickening. The filtrated carbonated lime is used as fertilizer.
The sugar is cleaned by solely physical processes (crystalline transformation and centrifugation). In contrast to widespread assumptions, white sugar is not bleached. Brown sugar only contains more colour (always brown).