Our Carbon Adsorption Towers
Activated carbon adsorption is the polishing tool for VOCs, solvent vapours, sulphur compounds, mercury and odour species that scrubbing chemistry can’t remove economically. The gas passes through a packed bed of granular or beaded carbon; contaminants physisorb to the high-surface-area carbon (iodine number 1000+ typical) until the bed reaches saturation — carbon is then regenerated or replaced.
Typical duties:
- VOCs and solvent vapours — styrene, toluene, xylene, MEK, acetone, BTEX
- Odour — H2S, mercaptans, amines (often with caustic / acid-impregnated carbon)
- Mercury vapour — sulphur-impregnated carbon for gold-process / chlor-alkali
- Polishing downstream of a scrubber where residual VOC carries through
Design parameters:
- Bed velocity 0.3–0.5 m/s for residence time
- Bed depth and frontal area sized against breakthrough curve and replacement interval
- Pressure drop typically 1 kPa per metre of bed
- Carbon loading 10–30% w/w at exhaustion, depending on adsorbate
- Replacement-only or regenerable (steam, hot N2)
- Materials: 304/316 SS for shell, PE/PP for cold acid duty
Project experience
Delivered projects:
- Deakin University (Melbourne, AU) — closed-loop activated carbon filter for an automotive wire-coating research facility. 95% VOC removal with two heat exchangers (air-to-air + air-to-water) managing fan inlet and downstream discharge temperatures.
- Plastic recycling facility (NSW, AU) — C1700-500-4 carbon tower as the second stage downstream of an H2SO4-dosed packed-bed wet scrubber, polishing residual VOCs after ammonia absorption. Stainless steel construction throughout.
- Nyanzaga Gold (Tanzania) via Lycopodium — sulphur-impregnated carbon beds on the mercury vapour scrubbing plants (kiln exhaust and gold-room fume), downstream of venturi pre-conditioners.
- Ahafo Gold (Ghana) via Lycopodium — packed tower wet scrubber + carbon for electrowinning fume control.
Selection is duty-specific — bed depth, carbon grade (impregnated for Hg or H2S, virgin GAC for VOC), and regeneration strategy. Send us the gas composition and target outlet; we’ll size the bed against the breakthrough curve.
Frequently asked questions
What does a carbon adsorber remove?
VOCs, odorous organics and mercury vapour — by adsorption onto activated carbon.
Virgin vs impregnated carbon?
Virgin granular activated carbon (GAC) for solvents and general VOCs; sulphur-impregnated carbon for mercury vapour, which virgin GAC will not hold.
Carbon vs thermal oxidiser?
Carbon adsorbs (and can recover) at low concentration; oxidisers destroy at higher concentration. The choice depends on the load and whether recovery is valuable.
How is a carbon adsorber sized?
Against the breakthrough curve for your measured gas — guaranteed to your target outlet, not a catalogue volume.
