The production technology of crystalline glucose is quite mature, but so far there are still more or less problems such as unstable product filtration rate, low filter membrane whiteness, process contamination caused by microorganisms or bacterial endotoxin exceeding the standard. The key to solving these problems is the purification of the sugar solution before crystallization, while the production of syrup products such as fructose and maltose has more requirements for syrup purification than worse.
Activated carbon decolorization and ion exchange resin desalination are the most common and reliable means to purify sugar liquid in starch sugar production. Although the glucose content of the syrup obtained after starch liquefaction and saccharification meets the requirements, it also contains various unfavorable impurities, such as: large molecular weight chromophore compounds, proteins, small molecular weight/polar chromophore compounds, odor and odor compounds , and hydroxymethylfurfural, etc. These impurities can be adsorbed and removed by using the porous structure of activated carbon, which is called "decolorization" in the industry.
So far, two types of activated carbon products have been widely used in the decolorization of starch hydrolyzed syrup. One is powdered carbon, which is generally used in a one-time use mode (i.e. discarded or incinerated after reaching saturation), and the other is granular activated carbon. It can be recycled after multiple regenerations.
Under the situation of advocating energy saving and emission reduction, developing circular economy and building green industry, the application of granular activated carbon decolorization and regeneration technology that can be regenerated and recycled many times and does not produce secondary pollutants is the development trend of the industry. Practice has proved that it has great quality and cost advantages.