Use different kinds of refined starch, such as corn starch, wheat starch or cassava as raw material to produce malt dextrin or glucose by the methods of acid hydrolysis or enzyme hydrolysis.
Acid hydrolysis is easily to produce some colorful material or non-fermentable sugar, because of adverse effect, in practice this method is stopped. We provide plants with enzyme hydrolysis to produce glucose or malt dextrin.
Theoretically, when DE value is less than 20%, i.e., reducing sugar contents is less than 20%, it is called as malt dextrin. But in daily use, the separation is not very clear.
i. Liquefaction
Glucose amylase used for saccharifying is kind of exoenzyme, hydrolysis from substrate molecules non-reducing end. In order to increase the chance of maltogenic amylase, speed up the reaction of saccharifying, it is necessary use a-amylase make the macromolecular glucose hydrolyze into maltodextrin and compound sugar. But the crystalline structure of starch particles has strong resistance of the enzyme.
(i ). Gelatinization and aging
If the starch milk be heated into certain temperature, the starch particles begin to expand, polarized cross is disappeared. With the temperature is higher, starch particles continue to expand to several times bigger or scores times bigger than original volume. As particle expend, crystalline structure disappeared, volume expand, particle contact each other, become into gelatinous liquid. Even stop the stir, starch is no longer deposit, this phenomenon is known as gelatinization. Generated sticky liquid is known as starch paste, this phenomenon temperature is the gelatinization temperature.
(ii ) Liquefaction
Liquefaction has many methods, the most ideal way is the jet liquefaction, 什om the various factory’s production conditions,when the vapor pressure > 0.8Mpa, choose the high pressure steam jet liquefaction process; when steam pressure ^ 0.5Mpa, choose low pressure jet liquefaction, the jet liquefaction process is divided into the once enzyme process and two times plus enzyme technology.
ii. Saccharifying
When the liquefaction is finished, quickly adjust the solution^ PH to 4.2M.5, at the same time cooling down to 60°C, then add saccharifying enzyme, keep the temperature 60°C . Keeping stirring to prevent uneven saccharifying, after reaction, After inspection with anhydrous alcohol and find that there's no maltodextrin, adjust the PH value to 4.8-5.0, and heat the solution to 80°C, keep the temperature for 20 minutes, and then to filter. Store the liquid in filtered solution into the storage tank, keep above 60°C temperature for further use.
iii. Filtering
After starch saccharifying, DE could be up to 98% (varies as per the configuration and customer’s requirements),but the starch hydrolyzed,it also takes insoluble impurities and ashes, fat, protein and so on, meanwhile in the procedure of hydrolysis, add some impurities, if we add acid, may bring inorganic salt, add enzyme, bring protein, in the procedure of decomposition, generate amylose and oligose, generated 5-HMF in the secondary reaction and other colorful materials and so on, they are need to be refined, so to improve the quality of glucose and quality of finished products.Therefore after saccharifying, it is necessary to make filtration.
iv. Decoloring
Decoloring the saccharified liquid of enzyme method is normally to adjust the PH around 4.8, The enzyme is kind of protein itself, the solution's PH is close to the protein isoelectric point, there is many suspended substances, many factories first use drum filter, which is made by diatomite pre-coating, or add used active carbon filter to remove the protein, fat and impurities, then do decoloring. The color of the saccharified liquid with enzyme method is light, we normally use twice decoloring with active carbon, and then do Iron Exchange (IX). Or sometimes not use active carbon for decoloring, but drum filter directly and then go for Iron Exchange.
v. Ion exchange (IX)
With the exchangeable ions on the functional groups fixed on three-dimensional network skeleton, changing ion concentration and other environmental conditions, so that it can repeat reversible exchange with external ion, and make the ion separation, replacement, concentration, removal of impurities and chemical catalytic purpose.
vi. Evaporation and concentration
Depend on processing requirements and technology, thereYe different types of concentrator, such continuously evaporation or batch evaporation, once evaporation or multi times evaporation.
vii.Crystallization
Crystallization is the process that makes the liquid into solid and separate the solid. It is also the most important method to get purities. Crystallization is the most important procedure in crystal glucose process. It directly influences the product quality and product yield.
Therefe different kinds of crystallization for glucose process. The process is kind of complicated, mainly relating to product quality and product yield. Here to describe the process as below:
(i ). Once crystallization process
(ii ). Twice crystallization process
(iii). Anhydrous glucose production line
viii.Separation and drying
Crystallization is the process that makes the liquid into solid and separate the solid. It is also the most important method to get purities. Crystallization is the most important procedure in crystal glucose process. It directly influences the product quality and product yield.
Therefe different kinds of crystallization for glucose process. The process is kind of complicated, mainly relating to product quality and product yield. Here to describe the process as below:
(i ) Separation
The mixture after crystallization contains particles of crystal and un-crystallized liquid (usually called mother liquid or greens), it is necessary to separate crystal glucose particles from mother liquor by centrifugal separator.
Load the liquid mixture and then rotated it by the centrifugal force, then the crystals are threw from the mother liquor into the basket and been discharged.
(ii ). Drying
Glucose drying machines include drum dryer, air stream dryer, and fluid bed dryer etc, some factories are using spray dryer to dry the high concentrated glucose solution directly to powder.
The drum dryer is rotating drum with steam jacket, drum has certain slope, glucx>se can be added from one side, it is slow flows in the barrel about 5r/min, such as 1000*5000mm drum dryer, with the capacity of around 10t/d.
Air dryer is the most common glucose drying machine, which consists of air heater, blower, air pipes, and cyclone etc. The separated glucose should be crashed first, and then brought up by the heated hot air flow.
ix. Maltodextrin production
Maltodextrin is divided into three main classes:
MD100: DE value,%(m/m) less than 10
MD150: DE value,%(m/m) less than 15
MD200: DE value,%(m/m) less than 20
x. WIP (Washing In Place)
Specification | GLU-1000 | GLU-2000 | GLU-3000 | GLU-5000 | GLU-8000 | GLU-10000 |
Nominal Output (kg/h) | 1,000 | 2,000 | 3,0000 | 5,000 | 8,000 | 10,000 |
Annual Output (8000H/Y) (Ton/Y) | 8,000 | 16,000 | 24,000 | 40,000 | 64,000 | 80,000 |
Area required (m2) | 300-400 | 450-550 | 500-600 | 600-700 | 800-900 | 950-1,050 |
Product collection rate | 98-99.5% (Depends on the specification, URS and technical parameters) | |||||
Final moisture contents (%) | ^ 3%(Depends on URS) | |||||
Bulk density of product (Kg/L) | 0.45-0.55 (Depend on the configuration, specification and processing parameters) | |||||
Discharge temperature (°C) | 35-45 °(Depends on configuration and URS) | |||||
Fuel | Any fuel, such as gas, LPG, oil, and coal etc, or other solid fuel, such as rice hull, coconut shells, |
Note:These parameters for reference only and will be changed as per URS.