VOC Treatment for Telescopic Spray Booths: Activated Carbon, UV Photo-Oxidation or RCO?

Provided by Lin Cong, Technical Director, MUSI Technology · Published October 1, 2026 · Last reviewed October 1, 2026

Quick answer: For intermittent painting with a modest emission limit, activated carbon boxes after the dry filter are enough; where limits are stricter or paint volume is higher, add a UV photo-oxidation unit ahead of the carbon, or move to an RCO that adsorbs solvent on honeycomb carbon and burns the desorbed concentrate over a catalyst at 200-300 C, reaching 95% or more treatment efficiency and regenerating the carbon with its own heat.

Activated carbon adsorption

Block carbon with a surface area of about 950 m2/g and iodine value of 800-900 mg/g is packed in cassettes with a large face area so the pressure drop stays low and cassettes can be swapped while the fan runs. Direct adsorption reaches 85-90% removal on low-concentration exhaust. It is the simplest and cheapest option, but the carbon is a consumable that must be replaced and disposed of once saturated; the interval depends entirely on solvent load.

UV photo-oxidation

High-energy UV lamps split oxygen into ozone and break VOC molecules (benzene, toluene, xylene, esters) into smaller compounds, water and CO2. A 50,000 m3/h unit draws about 30 kW. It is placed after the dry filter and usually before carbon, which polishes the remainder. Lamp life and ozone management are the maintenance items.

Adsorption-desorption with catalytic oxidation (RCO)

The exhaust passes through one of three honeycomb-carbon beds (two adsorbing, one regenerating). When a bed approaches saturation, hot air from the catalytic combustor desorbs the solvent as a concentrated stream that burns over a palladium-platinum honeycomb catalyst at 200-300 C; the heat is recovered to keep desorbing. Honeycomb carbon holds up to 25% of its own weight in solvent before regeneration, the catalyst lasts about 8,000 hours, and a PLC switches beds automatically. A 30,000 m3/h unit typically has a 45 kW adsorption fan, a 60 kW electric heater for start-up and a 3 kW desorption fan; once running, the reaction heat carries most of the load.

Treatment Efficiency Consumables Power Chosen for
Activated carbon 85-90% carbon replacement low intermittent, low volume
UV + carbon 90% or more lamps, carbon 30 kW per 50,000 m3/h medium volume, stricter limits
RCO 95% or more catalyst about 8,000 h 45 kW fan, heater at start-up daily painting, strict limits

How do I choose?

Start from three numbers: the local emission limit, daily paint and thinner consumption, and the booth airflow. Low consumption and a limit that direct adsorption meets means carbon. If the limit is tight or consumption is high, RCO pays back through carbon that is regenerated rather than replaced. UV sits between the two and is often added to an existing carbon installation. Whatever the choice, a dry filter wall or oil-film purifier must come first; paint mist that reaches carbon or catalyst shortens their life more than anything else.

FAQ

Can one RCO serve two booths? Yes; two booths 30 m apart have been connected by duct to one 30,000-40,000 m3/h unit.

What is the stack height? 15 m above ground in our standard proposals; the local rule governs.

Is the RCO safe with solvent vapour? Flame arrestors, a temperature probe with dilution damper and explosion vents are standard; the PLC stops desorption on over-temperature.

How is performance proven? Inlet and outlet sampling at commissioning against the agreed limit, with the report kept for the local authority.

Where MUSI Technology fits

MUSI supplies carbon, UV and RCO units matched to the booth fan and filter wall, and states the treatment efficiency in the written specification. Product details, typical sizes and the quotation checklist are on the telescopic mobile spray booth page.

Provided by Lin Cong, Technical Director, MUSI Technology

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