CSE's Roundtable on Pollution Control Technology options for Coal based power plants

July 8, 2016: Centre for Science and Environment (CSE) organized a roundtable inviting pollution control equipment manufacturers on Thursday to discuss various technology options available to meet the recently notified emission limiting standards for coal based power plants. The meeting was attended by 32 participants from 18 companies. 

Discussions were focused to come up with a technology matrix for different vintages which is cost effective and reliable, also other additional measures essential to push timely compliance. The meeting had three sessions and the key discussions in the sessions were the following 

Control of Particulate matter

• Significant capacity of Indian coal fired plants were designed for emission control levels below 100mg/Nm3 [after 1996] and 50mg/Nm3 [after 2000], however deviation from design level of emissions remain significant.

• ESP underperformance major reasons: 1) Boiler leakages; 2) Hopper level switches bypassed resulting in ash build up and deformation of ESP internals; 3) improper maintenance of rapping and seal air system 4) insulator cracks 5) Old controller systems

• Key Up gradation Techniques: 1) adding fields/ESPs, increasing height of ESPs; 2) Flue gas conditioning; 3) Moving electrodes, changing electrodes; 4) Low – low temperature ESP systems, 5) High frequency Transformer-rectifier sets etc.   

Control of Sulphur di Oxide 

• Debate whether pre-2003 plants must control SOx emissions and related techno-economics

• Low cost reliable technology to meet 600 mg/Nm3 standard. Options recommended: - partial wet FGD, combined wet FGD, dry FGD

• Sorbent injection not possible for immediate take up as there is no enough experience 

Control of Oxides of Nitrogen

• Control measures – burner modification, Selective non catalytic reduction (SNCR), Selective Catalytic Reduction (SCR) 

• Mechanism to be specified to ensure necessary approvals for supply of liquefied ammonia, catalyst waste disposal, etc.

Additional suggestions made include, 

1. Minimum technical specification draft be prepared to avoid confusions and facilitate easy tendering process for coal power stations

2. Ensure policies are put in place to make available the raw materials 

3. Request Ministry of Environment, Forests and Climate Change (MoEF&CC) to make available feasibility report of compliance for each power plant on public domain

4. Request various government authorities – MoEF&CC, Ministry of Power (MoP), Central Electricity Authority (CEA), Central Electricity Regulatory Authority (CERC) to co-ordinate for evolving financial schemes and tariff recovery mechanism 

The meeting concluded with the follow-up action point,

1. Technology matrix paper be prepared as a measure to increase awareness among various stakeholders especially state thermal power stations