Wood-Based activated carbon: pressure drop in deep beds and gas service

Buyers comparing wood-based activated carbon usually arrive with the same question: which form does this duty actually need? The answer follows from the vessel and the contaminant, not from the headline iodine value alone.

Extruded or crushed block carbon with low pressure drop for deep beds and gas service. Block and pelletised carbon is used where a deep bed would otherwise cause an excessive pressure drop, and in gas service where mechanical strength and low dust matter.

For the wood-based series the reference ranges are 800-1300 mg/g iodine value and 900-1500 m2/g BET surface area, produced by phosphoric acid or physical activation. Compare grades inside one series with caution: iodine value is a microporosity indicator, so a grade with a lower iodine value can still outperform a higher one where larger molecules dominate. Watch for a rising outlet concentration, a colour or odour change, or an increasing pressure drop. Any of these indicates the bed is loading up; arrange a test or a replacement before the outlet goes out of specification. Thermal regeneration and acid washing are the usual recovery routes.

Before contacting a supplier, write down the medium, the flow rate or concentration, the target outlet quality and the particle size your equipment accepts. Those four points are what turn a general enquiry into a usable quotation.