The removal of gaseous polluting constituents can be achieved by following processes

1. Absorption by liquid solution

2. Condensation of pollutants by cooling the gas stream

3. Adsorption on a porous adsorbent

4. Chemical conversion of pollutants into harmless chemical compounds

5. A combination of above techniques

Most of the systems are based on above techniques but in some cases a combination of above methods is used. Choosing the pollutant removal method depends mostly on physical and chemical properties of the pollutants and the conditions under which the pollutant is treated.

Absorption is basic chemical engineering operation and is most preferred and well established gas pollution control technique. It is used extensively in the separation of corrosive, hazardous or noxious pollutants from the waste gases. The major advantage of absorption is its flexibility, as it can handle a range of feed rates. Absorption, also called scrubbing, involves transferring pollutants from gas phase to contacting solvent. The transfer occurs when the pollutants partial pressure in the gas phase is higher than its vapor pressure in equilibrium with its solvent. The pollutant must first be absorbed into a liquid phase for the reaction to occur and the pollutant concentration is reduced to low level to achieve high absorption capacity.

 

Generally solvent/reactant selected, should be non-volatile at operating temperature and pressures to prevent excessive carryover in the gas effluent. Other favourable properties are low flammability and viscosity, high chemical stability, acceptable corrosiveness, low toxicity, and pollution potential.

 

 

COMBUSTION RESEARCH ASSOCIATES offers Venturi Jet, Packed bed or integrated systems involving packed bed and venturi jet, for gases, fumes, solid or dust suspensions, chemical waste gases., flue gases, odor removal, sanitary land fills etc. The systems are designed to achieve high toxic removal efficiency using state of art techniques.

 

The scrubbers offered are of regenerative or non-regenerative type

 

In these scrubbers solvents remove the toxic chemicals from the waste gases and the solvent is regenerated in another chamber. The chemical recovered by regeneration of gases can have commercial value. The operating cost of these scrubbers is generally low but the capital cost is high.

 

 

The solvents in this type of scrubbers are exhausted with the use and cannot be regenerated. The operating cost is slightly higher but the capital cost is low.

 

 

The materials selected are based on the compatibility with the working medium, toxicity, operating parameters, economy and long life of equipment. Major materials being used are SS 316, SS 304, FRP, HDPE, high nickel alloy steels, ceramics, coatings etc

 

    Chemical, petrochemical, food processing, pharmaceutical and related industries

    SOx, H2S, CO2, NH3  etc removal from gases

    Steel, cement plants etc

    Paint, synthetic resins, adhesives manufacturing plants

    Waste treatment plants

    Smoke fumes and engine exhaust

    Flue gas de sulpharisation

    Removal of odors from gases

    Manufacturing centers with fine dust/ fumes

    Biogas, producer gas, manufactured gas etc

    Mining and metallurgical

    Hazardous waste