Poor selection of activated carbon leads to significant degradation and a short lifespan. Generally, it needs to be replaced every 6 months to 1 year, and the cost of replacing activated carbon is very high. Specialized activated carbon has an adsorption capacity of over 100% and good adsorption and stability, resulting in a lifespan of 2-3 years or more and cost savings. The specific surface area and pore structure of activated carbon are closely related. Different organic solvents require activated carbon with different pore sizes to ensure minimal attenuation, low gas pressure resistance, strong adsorption capacity, and easy desorption. This ensures fast gas flow rate and eliminates local temperature rise phenomena.
Activated carbon for organic waste gas treatment has the advantages of reasonable pore size distribution, high adsorption capacity, fast adsorption rate, high mechanical strength, use in fixed beds, low gas flow resistance, easy desorption and regeneration, etc. It has strong adsorption capacity for most inorganic gases (such as sulfides, nitrogen oxides, etc.) and most organic vapors and solutes in a wide concentration range.
Indicators of activated carbon for organic waste gas treatment:
Adsorption index: Carbon tetrachloride CTC, good, above 100% benzene adsorption: good, above 50% acetone adsorption: above 50%
Intensity: 70-90% or above, depending on the specific application. The higher the strength, the better. The higher the strength, the lower the adsorption may be.
Proportion: The higher the proportion, the higher the cost, indicating that the specific surface area is smaller and more solid. The larger the specific gravity of the same cube, the heavier it becomes.
Ash content: below 6%, moisture content<5%. Impurities that are too high can also affect adsorption and cost.
Fire point:>450 degrees
Material: Mainly choose wood or coal, coconut shell is not suitable because organic solvents require mesoporous activated carbon. If coal meets the above indicators, the cost will be higher than wood. Ordinary coal based activated carbon CTC50-70% benzene adsorption: 20-40% wood chemical Activated carbon: CTC: 100% -140% benzene adsorption: 45-60% specific gravity is only half of coal.
Organic waste gas treatment activated carbon treatment method
By adsorbing exhaust gas with activated carbon, when the adsorption is saturated, the activated carbon desorbs and regenerates, blowing off the exhaust gas and catalyzing combustion to convert it into harmless substances. The regenerated activated carbon continues to be used. When the adsorption capacity of activated carbon significantly decreases after a certain number of regenerations, it is necessary to regenerate or update the activated carbon. Activated carbon is currently the most commonly used method for treating organic waste gas, with good adsorption performance for benzene waste gas, but poor adsorption performance for hydrocarbon waste gas. The main disadvantage is that the operating cost is high and it is not suitable for environments with high humidity. However, for current market applications, activated carbon adsorption is the most commonly used method.
https://www.naturecarbon.com/high-performance-activated-carbon/koh-impregnated-activated-carbon.html
