Ammonia Flue Gas Injection System to Reduce SPM Level in Coal Fired Boiler ESPs.

UNICON Group, entered in to a Memorandum of Understanding (MoU) with HWB-Department of Atomic Energy, for transfer of Ammonia Flue Gas Conditioning Technology. This technology will reduce the SPM level for Coal based Thermal Power Plants.

The air we breathe contains many pollutants, major contribution being dust of SPM (Suspended Particulate Matter), the prime cause for many respiratory diseases including silicosis. The presence of SPM in the air is due to vehicular traffic and through the emissions from major industries particularly power and cement. The need of the hour is to control the SPM emissions.

Area of application

The flue gas from coal fired boiler furnace contain suspended fine fly ash particles. The quantum of emission of SPM is required to be controlled as per the statutory requirements set by the Pollution Control Board. The SPM is reduced universally by use of Electrostatic Precipitators (ESP) which function by imparting electric charge on the suspended particles by applying high voltage and then collecting them on charged collector plates.

The Quality of coal, increased ash content, ash resistivity and many other factors result in the lower performance of ESP and consequent increase in SPM. Many technologies have been tried out for improving the performance of ESP but with limited success. With environmental standards being upgraded for cleaner air quality, time has come for upgrading and developing newer technology for overcoming the above problem.


This technology has been developed by HWB, Department of Atomic Energy and patented in India. This technology is tested and proved in the plants owned by the Department. Now to reduce the SPM in old ESP’s we have the options like increase in collecting area, addition of fields, etc for which space and capital investment are main constraints, But now we have proven technology patented by HWB – Ammonia flue gas conditioning system. We have to inject ammonia at inlet of the ESP which acts as a conditioning agent and increase the resistivity of the dust which in turn enhances the collection efficiency of the ESP in general.

Today the need for the power is increasing and the major source of power is produced in India is from burning coal. While the coal is fired in the boiler, flue gas is generated and let to the atmosphere with dust particles which are hazardous to our health.


The technology results in reduction of SPM emission drastically from a level of 600-700 Mg/NM3 to 20-70 Mg/NM3. Clean and green environment is an irrevocable mandate of all the industries. The Technology developed for flue gas conditioning to reduce the SPM emission is extremely safe and the performance of the system is truly rewarding. The simplicity is that it can be integrated in the existing plants for reduction of SPM with minimum modifications and without down time at low cost. This new technology is a boom to the existing equipments which were installed way back, they are finding it difficult to meet the requirements of the present .