Activated carbon decolorization is a critical process in the production of pharmaceutical products, fine chemicals, and food and beverages. It plays a crucial role in ensuring product quality, yield, cost, and environmental protection.
After the decolorization treatment, activated carbon does not eliminate itself but becomes a new impurity, requiring its removal and filtration. However, the use of filter cloth as the filter medium often leads to incomplete separation and inadequate removal of activated carbon due to its wide particle size distribution and powder form. This can negatively impact the color and grade of the material.
Traditional decolorization filtration program and problems
The traditional decolorization filtration method using a press filter has several drawbacks:
• Manual slag removal is required, leading to low automation, cumbersome operation, high labor intensity, and low efficiency.
• The use of filter cloth as the medium allows some activated carbon to penetrate through, affecting product quality and resulting in rework treatment and losses.
• It is challenging to achieve the desired level of dryness for the piled-up wet product, leading to material losses and environmental pollution.
• Each batch requires a carbon removal operation, leading to frequent opening of the equipment lid and increased maintenance costs due to wear and tear on the flange waterproof line.
• The equipment does not meet GMP requirements in the pharmaceutical field, and the use of filter cloth as the filtration medium may result in the fiber tissue falling off and affecting product quality.
Additionally, equipment leakage and pollution of the production environment are also concerns.
Therefore, there is an urgent need to find a technological solution for the activated carbon decolorization filtration process to address the aforementioned challenges.
Cake filtration principle
When the slurry passes through the filter media, it forms a bridge on the surface of the filter element, causing suspended particles and impurities to gradually accumulate into a cake. The cake continuously intercepts subsequent particles, thereby increasing the thickness of the cake layer. This filtration process is known as cake filtration. Cake filtration improves filtration precision and ensures satisfactory filtration of the clear liquid, effectively addressing the issues of filtering and leakage that were present in the past.
Selfclear Automatic Filtration System
Feature-Tec has developed and designed the Selfclear automatic filtration system, which is specifically designed for continuous production. This system is capable of automatically filtering and removing particles from liquids or gases, resulting in the formation of a dry filter cake that can be easily discharged.
The Selfclear system offers several key features, including full automation, eliminating the need for downtime, reducing the need for manual cleaning, and eliminating the need for filter element replacement. It is highly suitable for use in continuous production environments, especially in high-risk operating conditions where impurities tend to be sticky and not easily handled by ordinary metal filter elements.
Furthermore, the Selfclear fully automatic filtration system complies with GMP requirements, ensuring that it meets the necessary standards for use in pharmaceutical and other industries where strict quality control is essential.
Structural features
• The process, washing, and drying functions of the system can be adjusted according to specific requirements.
• The filter element features a special skeleton structure to prevent the filter cloth from breaking.
• The system is equipped with a bottom pipeline feeding mechanism to prevent material clogging.
• An optional carbon leakage detection device can be added for enhanced safety and monitoring.
Advantages of the equipment
• Integration of filtration, washing and drying functions
• Fully automatic operation, reducing labor intensity
• High filtration precision, effectively intercepting fine activated carbon.
• Dry cake slagging reduces filtrate loss.
• The equipment meets GMP requirements and can realize online and in-situ cleaning.
Establishment of twice adsorption equilibrium, reduce the dosage of decolorant.
The tightening of China's environmental regulations has increased the demand for more efficient waste decolorant disposal. Simultaneously, the rising cost of decolorant procurement has compelled enterprises to continuously improve the decolorant process to minimize expenses.
Countercurrent decolorization process
The decolorization process has achieved a balance with the adsorbent, which still possesses some decolorization ability when in contact with fresh material. This enables the utilization of a countercurrent decolorization process, reducing the consumption of decolorant. Once the decolorization is completed, the material will come into contact with the filter cake layer of the decolorant. After reaching a second adsorption equilibrium, it will be mixed with fresh decolorant for subsequent decolorization.
Continuous countercurrent decolorization process flow chart
Adopting continuous countercurrent decolorization process can save about 30% of activated carbon or decolorant, reduce material loss, thus improve harvest rate, reduce pollutant emission, and achieve good social and economic benefits.
Typical applications
• Filtration after cryo decolorization
• Sulfadiazine decolorization process
• Decolorization and filtration of crude adipic acid slurry
• Fine sugar decolorization
• Glucose decolorization filtration
• Vitamin decolorization filtration
• Amino Acid Filtration
• Monosodium glutamate decolorization filtration
• ......
Other Filtration Methods
In addition to the activated carbon decolorization filtration system, Feature Tec has also developed an all-in-one acorber cartridge that integrates traditional filters and combines adsorption and filtration functions into one, providing a more convenient and efficient production process.
The Feature-Tec acorber cartridge is designed with an internal adsorption material and an outer PP protective film curing structure. This design prevents the carbon from being easily crushed or liquefied and ensures that there is no side leakage of filtrate during the filtration process. As a result, the filtration efficiency and service life are effectively improved.
Product features
• Ultra-fine activated carbon particles, strong adsorption capacity;
• Stable cartridge structure, high mechanical strength, not easy to deform;
• A variety of carbon powder materials are available for selection, applicable to different processes;
• The outer protective structure prevents the carbon particles from leaking, which effectively improves the filtration efficiency and prolongs the service life of the cartridge.