Is a higher iodine value always better for activated charcoal?

I. What is iodine value？

Iodine value refers to the ability of activated carbon to adsorb iodine molecules, usually expressed in milligrams per gram (mg/g). It is an important indicator of the degree of microporous development in activated carbon; a higher iodine value generally means that the activated carbon has more abundant micropores and a larger specific surface area. Measuring the iodine value is a rapid and effective method for assessing the adsorption capacity of activated carbon for small molecules.

II. Advantages and limitations of high iodine levels

High-iodine-value activated carbon performs exceptionally well in treating small molecules. In fields such as gas-phase adsorption and gold refining, high-iodine-value activated carbon offers superior performance. However, the iodine value only reflects the activated carbon's adsorption capacity for small molecules. It cannot comprehensively reflect the adsorption performance of activated carbon for all substances, especially those with larger molecular diameters.

III. Why is a higher iodine value not always better?

1. Pore Size Distribution Matching Principle: The adsorption effect of activated carbon depends on the degree of matching between its pore size distribution and the size of the target pollutant molecules. When treating macromolecular pollutants, activated carbon with well-developed mesopores and macropores is needed, rather than just microporous carbon with high iodine value.

2. Strength and abrasion resistance: Excessive pursuit of high iodine value often leads to a decrease in the strength of activated carbon, making it easy to break and produce powder during use, which in turn affects the performance and lifespan.、

3. Cost-effectiveness considerations: Preparing high-iodine-value activated carbon requires more stringent process conditions and raw materials, which significantly increases costs. Blindly pursuing high iodine values will only lead to a waste of resources.
   

· Fujian Guangyuan Carbon Products Co.,Ltd.