Ammonia Solutions in Denitrification: 4 Effective Methods to Reduce Power Generation NOx

Ammonia underpins NOx reduction in power plant denitrification. Even so, nevertheless, a pivotal question persists: how can we procure and employ ammonia safely and cost-effectively?

What is a SCR system? It’s a technology that leverages ammonia to reduce NOx emissions. This article probes four methods. These comprise anhydrous ammonia, SNCR, SCR with urea solution, and Guantong’s urea pyrolysis. They serve to achieve efficient NOx emission control.

This also enhances safety and optimizes costs. Because of this, utilizing ammonia solutions, power plants can conform to stringent regulations.

Method 1: Anhydrous Ammonia/High-Concentration Ammonia Water – Efficient but High-Risk

Ammonia solution, manifesting as anhydrous ammonia or high-concentration ammonia water, furnishes high NOx reduction efficiency. This attains up to 95%.

Nevertheless, ammonia storage presents substantial risks. That is why the principle entails introducing pure ammonia into the flue gas stream. There, it engages with NOx to yield nitrogen and water. Thus, it advances nitrogen applications as a harmless byproduct.

Anhydrous ammonia is deemed toxic, flammable, and necessitates high-pressure storage. OSHA and EPA govern this storage. Here’s a financial consideration: Storage exceeding 10,000 pounds triggers costly Risk Management Plans (RMP), with permitting fees reaching $100,000.

• Risk: Leaks can lead to $500,000 in safety violations. That is a hefty sum.
• Recommendation: Limit use to small-scale applications with strict safety protocols.

Method 2: SNCR – Economical but Limited Efficiency

SNCR (Selective Non-Catalytic Reduction) introduces urea or ammonia solution. This occurs within the furnace’s high-temperature zone, spanning 850–1250°C. This occurs sans a catalyst. What does SCR denote? Conversely, SNCR proves simpler and more cost-effective than selective catalytic reduction. Nevertheless, it attains merely 40–70% NOx reduction. Its efficiency exhibits high sensitivity to temperature windows. Boiler load fluctuations can diminish effectiveness by 20%.

• Limitation: Inconsistent performance in variable load conditions.
• Case Study: A power plant using SNCR saved 30% on installation costs but struggled with compliance during load changes.

Method 3: SCR (Direct Urea Solution Injection) – Safer but Flawed

What comprises diesel exhaust fluid (DEF)? DEF, or DEF fluid for diesel, constitutes a urea solution. It comprises 32.5% urea and 67.5% deionized water. This solution undergoes injection into the flue gas for selective catalytic reduction.

What denotes urea within DEF? It serves as the ammonia source. It decomposes at 190–600°C to engage with NOx. What forms DEF? Urea and deionized water. However, direct injection entails risks. Incomplete decomposition at low temperatures engenders urea crystallization. This impedes nozzles and pipes, elevating maintenance costs by 15%.

• Challenge: Ammonia slip due to poor DEF quality reduces efficiency.
• Recommendation: Monitor ammonia levels to prevent slips.

Method 4 (Guantong’s Recommendation): Urea Pyrolysis for SCR – Safe, Efficient, Reliable

alt: Complex industrial piping and equipment at a plant, representing advanced urea pyrolysis technology.

Guantong’s urea pyrolysis system constitutes an advanced ammonia generator. And it employs safe, non-hazardous urea in DEF to yield clean ammonia for SCR systems.

The system operates at 350–600°C within a dedicated pyrolysis furnace. This guarantees complete decomposition, thereby obviating crystallization risks. Process control instruments and Coriolis flow meters attain ±0.1% metering accuracy. This delivers over 90% NOx reduction. This method combines safe ammonia delivery with high efficiency, reducing operational costs by 20%.

• Advantage: No liquid ammonia storage, ensuring compliance with safety regulations.
• Case Study: A power plant using Guantong’s ammonia generator reduced NOx emissions to <50mg/Nm³, saving $150,000 annually.

Table 1: Comparison of NOx Reduction Methods

Method	Efficiency	Risks/Limitations	Solution
Anhydrous Ammonia	95%	Toxic, flammable, costly RMP	Strict safety protocols
SNCR	40–70%	Temperature-sensitive, inconsistent	Optimize temperature control
SCR (Direct Urea)	80–90%	Crystallization, ammonia slip	Monitor ammonia levels
Urea Pyrolysis (Guantong)	>90%	None, safe and reliable	Ammonia generator

Conclusion

The choice of ammonia-based method determines your emission control system’s safety and cost-effectiveness. What is a SCR system? A technology powered by SCR technology for efficient NOx reduction. Guantong’s urea pyrolysis furnishes the safest, most dependable solution. It transforms power plant denitrification. This occurs through clean ammonia and secure ammonia delivery. Contact Guantong to implement our advanced urea pyrolysis technology for superior NOx reduction!