Machine de fabrication d'acide citrique de qualité alimentaire complète complète

Citric Acid Project Introduction

Corn dry milling: After removing the impurities and measuring, the cleaned corn enters the miller for the milling. Then, the impurities are removed through the rotary vibrating screen. After that, the cleaned corn flour is sent to the storage tank. Corn flour size: pass rate of 60 mesh sieve ≤30%.

Slurry adjusting: Add water to adjust the corn flour slurry to DS=28-32%. The measured corn flour slurry is sent to the PH adjusting tank. Adjust the PH by the NaOH solution and add the appropriate amount of liquefaction enzyme.

Liquefaction: Send the qualified corn slurry to the 1st jet cooker and maintaining tank, so as to get the liquefied material. After adding the enzyme, it is sent to the 2nd jet cooker and maintaining tank. Then, it enters the liquefaction column for the liquefaction to get the desired DE value.

Filtration: After liquefaction, the crude protein is filtered through filter press. The filtrate is sent to the next section. After drying the filter cake, crude protein can be obtained.

Fermentation: After liquefaction, the glucose was sent to the fermenting tank, DS and PH were adjusted, and then sterilized and cooled to 35 ° C. Seeds are added to fermenters through sterilized pipes to ferment, delivering sterile air continuously. Fermentation ended when the remaining glucose content fell below 1g/L.

Filtration: The filtration is divided into two times. In addition to the citric acid product, the fermented mash contains some impurities, such as the mycelium. First, the impurities are filtered to ensure the quality of citric acid. The filtered cake mycelium was washed and sold to feed production, and the filtrate was dilute citric acid to the 1st neutralization & filtration section.

After the 1st time filtration, there are still some impurities. The 2nd filtration is needed to remove the impurities again to ensure that the filtrate is clean and transparent. After cleaning the filter cake, the filtrate was dilute citric acid to the 2nd neutralization & filtration section.

Neutralization & filtration: This section also contains two times neutralization and filtration. The first is the 1st neutralization& filtration. Precipitated Ca3(C6H5O7)2•4H2O was obtained by adding CaCO3 to the dilute citric acid and filtering through the belt vacuum filter. The filtrate goes to the wastewater treatment plant as the waste water.

This is followed by 2nd neutralization& filtration. The precipitated Ca3(C6H5O7)2•4H2O reacts with the dilute citric acid after the 2nd filtration and adjustment, and is filtered through the belt vacuum filter to obtain precipitated CaH(C6H5O7) •3H2O. The filtrate is returned to the 1st neutralization section.

Acidification: The precipitated CaH(C6H5O7) •3H2O reacts with the added H2SO4 to obtain citric acid (C6H8O7) and CaSO4 after adjustment. CaSO4 is filtered through the belt vacuum filter and then sold to gypsum producers. The crude citric acid goes into the following sections for refining.

Decolorization/filtration: The citric acid enters the decolorization and filtration system. Decolorization requires activated carbon at the appropriate temp. After decolorization, the activated carbon will be removed by the filter. Then the filtered citric acid is sent to the next section.

Continuous ion exchange: The filtered citric acid enters the continuous ion exchange system to remove the mixed impurity ions in the citric acid through the cation and anion resin, so as to obtain the refined citric acid.

Evaporation: The refined citric acid enters the evaporator system for concentration to obtain the desired DS value for the next section.

Crystallization: The evaporated citric acid enters the crystallizer system for the crystallization. After a certain time of crystallization, qualified citric acid crystal was obtained and then entered into the centrifugal separation section.

Centrifugal separation: After crystallization, through the centrifugal high-speed separation, obtain the qualified citric acid crystal and mother liquor. The mother liquor enters the production section of citric acid monohydrate.

Drying and screening: The wet anhydrous citric acid crystal is sent to the dryer to get the dry products, and then sent to the vibrating screen to get qualified anhydrous citric acid products.

Citric acid monohydrate evaporation: The mother liquor separated by anhydrous citric acid centrifugation enters the evaporator system for concentration to obtain the required DS value.

Citric acid monohydrate crystallization: The evaporated citric acid enters the crystallizer system for the crystallization. After a certain time of crystallization, the qualified citric acid crystal was obtained and then entered into the centrifugal separation section.

Citric acid monohydrate separation: After crystallization, through the centrifugal high-speed separation, obtain the qualified citric acid monohydrate crystal and mother liquor. The mother liquor is first returned to citric acid monohydrate evaporator for reuse; When the quality is not qualified, the mother liquor will be returned to the front of the neutralization section for reuse.

Citric acid monohydrate drying and screening: wet citric acid monohydrate crystal is sent to the dryer to get the dry products, and then sent to the vibrating screen to get the qualified citric acid monohydrate products.