Following on from last issue’s filter test, here we have the results from the butane test, that give us a great idea on the total surface area, and therefore an indication of the total adsorption capabilities of the carbon.
It is fairly straight forward, the higher the number, the higher the potential rate for adsorption there is. An almost indiscriminate adsorption though. It doesn’t give us details on what quantity of that surface area is dominated by either macro, micro and meso pores: micro and meso being the ones we would be most interested in having a high percentage of. As a rule of thumb, coal based carbon will have a mix of all types of pores to varying degrees depending on the source, and coco carbon will generally be mostly micro and meso pores. Also it gives no indication of the overall charge of the carbon, which also affects how well carbon will adsorb particular VOCs.