Molasses is a nutrient for yeast and is the substrate most frequently used in the fermentation industry. It forms as a residual product in sugar refining as soon as no more sugar can be crystallized out of the raw mass. In addition to the residual sugar, raw molasses also contains vitamins and minerals which further favour growth of the fermenting microorganisms.
In addition, however, the untreated raw material also contains substances which inhibit the growth of the organisms and can lead to problems in the process downstream. These include sand, calcium and proteins originating from the sugar crop itself or from sugar production. This is why unwanted substances have to be removed from the raw molasses by clarification for fermentation process reliability.
Centrifuges from GEA Westfalia Separator Group are able to remove the above-mentioned substances from the molasses. Their clarification performance ensures not only a high yield from the fermentation process, but also reliable protection of downstream aggregates and installations.
To reduce the high viscosity, the raw molasses is diluted with water in a mixer in a first step and then pre-heated using a heat exchanger. The molasses then has to be acidified with sulfuric acid. Following acidification, the calcium precipitates in the form of gypsum and is thus easily separated in the separation process. Coarse erosive particles such as sand are separated by a rotary brush strainer and / or a hydrocyclone to protect the centrifuges downstream from wear.
Actual clarification of the molasses then finally takes place in the clarifier. The clarified molasses is finally sterilized, cooled and passed to the storage tank. An extra integrated decanter recovers the residual sugar which is fed back into the process.