Industrial Odor Control Systems
Odour treatment systems for H₂S, VOCs and corrosive emissions
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Multi-technology odour and H₂S treatment for industrial and municipal gas streams
CRA’s Industrial Odour Control Systems are engineered to remove odour-causing compounds from complex industrial and municipal gas streams. Built on decades of experience in H₂S removal, sulphur treatment, and emissions control, our systems help facilities control nuisance odours, protect equipment, improve workplace safety, and meet environmental regulations through chemical, biological, activated carbon, and hybrid odour treatment technologies.
Target Compounds
H₂S, VOCs, mercaptans
Technologies
Chemical, biological, carbon
Application
Industrial & municipal
Operation
Continuous duty
What is an Industrial Odor Control System?
Industrial odour control systems remove odour-causing compounds, including hydrogen sulphide, volatile organic compounds, ammonia, and mercaptans, from industrial and municipal gas streams, protecting equipment, improving workplace safety, and helping sites meet environmental regulations.
How it works
Treatment technology is selected based on the contaminant profile, gas flow rate, and site operating constraints, then applied through one or more of CRA's four treatment methods.
Treatment technology is selected based on the contaminant profile, gas flow rate, and site operating constraints.
Circulating alkaline or oxidising solutions in packed towers remove high concentrations of odour-causing compounds.
Bacteria colonising packing media treat moderate contaminant loads continuously, without chemical input.
Activated carbon adsorption removes residual odorous compounds, bringing outlet concentrations down to low final levels.
Where a single technology cannot meet the full treatment requirement, two or more stages combine into one system, such as biological pretreatment followed by carbon polishing.
Key Benefits
Designed to handle H₂S, sulphur compounds, VOCs, ammonia, mercaptans and corrosive industrial emissions.
Chemical, biological, activated carbon and hybrid odour treatment systems are engineered under one roof.
Built for continuous operation in corrosive, high-moisture and variable-flow operating environments.
Optimised designs reduce chemical consumption, maintenance, pressure drop and energy use.
Designed to control nuisance odours, worker exposure and environmental emissions in line with the regulations that apply at site.
The CRA Edge
CRA has decades of experience treating H₂S, sulphur compounds and corrosive industrial gases.
Chemical, biological, activated carbon and hybrid systems are engineered under one roof.
Designed for harsh industrial conditions, fluctuating flows and demanding operating environments.
Engineering, fabrication and controls are handled in-house.
Applications
Frequently Asked Questions
What does an industrial odour control system do?
An industrial odour control system removes odour-causing compounds such as hydrogen sulphide (H2S), mercaptans, VOCs, ammonia and other sulphur compounds from industrial or municipal gas streams before they are released. The main technologies are chemical scrubbing, biological scrubbing, activated carbon adsorption and hybrid systems that combine them. CRA engineers these systems around the gas analysis for wastewater headworks and sludge handling, biogas, landfill gas, composting and industrial process exhausts.
Which technology is best for removing H2S odour?
The right H2S technology depends on inlet concentration, gas flow, moisture, the required outlet level and the operating cost the site can carry. For gas-engine duty CRA offers biological scrubbers, which run at low operating cost. For CBG and biomethane duty, and for high inlet H2S loads, CRA offers the chemical scrubber with biological regeneration, which keeps the fast chemical absorption step while regenerating the solution biologically. Activated carbon is used for final polishing after a wet scrubber where a low outlet H2S is required.
What is the difference between a chemical scrubber and a biological scrubber?
A chemical scrubber uses a reactive solution, such as caustic or an oxidising agent, to absorb and neutralise contaminants like H2S and ammonia quickly in a counter-current column. A biological scrubber uses naturally occurring micro-organisms to oxidise the contaminants into less harmful compounds, which cuts chemical consumption and operating cost. CRA also offers a chemical scrubber with biological regeneration, which combines the two: the chemical stage absorbs the H2S and a biological stage restores the alkalinity of the solution and converts the sulphur to elemental sulphur.
What does CRA supply in an odour control system?
CRA designs and manufactures the odour control equipment itself, as a complete engineered package. Scope typically covers review of the gas analysis, process evaluation, technology selection, engineering, skid fabrication and the automation system. Chemical, biological, activated carbon and hybrid systems are engineered under one roof at CRA's works in Noida, with mechanical, electrical and process design in-house. Retrofit of an existing odour control installation can be assessed on a project basis.
How does activated carbon odour removal work?
Activated carbon systems pass the gas through a bed of highly porous carbon media, which adsorbs the odour-causing compounds onto its internal surface. They are effective for VOCs, sulphur compounds, siloxanes and trace contaminants in polishing and low-concentration duty. In H2S service CRA uses activated carbon as a polishing step after a wet scrubber: the wet scrubber takes out the bulk of the H2S and the carbon bed brings the outlet concentration down further. The media is replaced once it is saturated.