Industry
Emission Control Materials for Thermal Power
Emission problems, pollutants, operating conditions and recommended materials for the thermal power sector.
Typical emission problems
- NOx emissions from coal combustion
- High flue gas temperature
- High dust loading before the precipitator
- SO₂ present in the gas stream
Main pollutants
- NOx
- SO₂
- Dust
Operating conditions
Coal-fired flue gas typically ranges 300–400°C at the SCR position with high dust and SO₂. Catalyst geometry must resist erosion and plugging while keeping pressure drop within the fan budget.
Recommended material selection
- Plate-type SCR catalyst for high-dust positions
- Honeycomb SCR catalyst for low-dust (tail-end) positions
- CO oxidation catalyst where CO control is also required
Engineering considerations
In a typical coal-fired unit the SCR reactor sits between the economizer and the air preheater — the high-dust position — where it sees the full fly ash load at 300–400°C. Catalyst geometry therefore matters as much as chemistry: large-pitch plate elements resist plugging and erosion, and the spare layer position is planned from day one so that future replacement does not force a full reactor rebuild.
Ammonia injection and mixing determine how much of the installed catalyst is actually used. A badly tuned AIG creates local ammonia-rich and ammonia-starved zones — the plant then over-injects to hold NOx compliance and pays for it in ammonium bisulfate fouling downstream. For this reason we recommend measuring the velocity and NOx distribution at the reactor inlet before finalizing catalyst volume.
Fuel quality drives deactivation: high-arsenic coals poison pores irreversibly, while alkali-rich fuels neutralize acid sites. The same DeNOx target can require 20–40% more catalyst volume on a difficult fuel, which is a material-selection decision rather than a price decision.
Tell us about your stream
Gas flow, concentration, temperature, humidity, SO₂ and dust — we will recommend the right catalyst or adsorbent system.