SCR Denitrification Technology
A brief introduction to SCR denitrification technology.
SCR denitrification technology
SCR (Selective Catalytic Reduction) is an advanced stationary source nitrogen oxide (NOx) control technology. Its core principle is: under the action of a specific catalyst, a reducing agent (usually ammonia or urea) selectively reduces NOx in flue gas to harmless nitrogen (N₂) and water (H₂O), while minimizing other side reactions.
Core Chemical Reactions:
4NO + 4NH₃ + O₂ → 4N₂ + 6H₂O₂
2NO₂ + 4NH₃ + O₂ → 3N₂ + 6H₂O
Technical Features
Features | Description | Advantages |
High Denitrification Efficiency | Under optimal operating conditions, denitrification efficiency can reach over 90%, even exceeding 95% | Meets the most stringent emission standards (such as China's Ultra-Low Emission Standards and EU BAT) |
High Selectivity | The reducing agent mainly reacts with NOx, without consuming large amounts of O₂ in the flue gas, avoiding ineffective consumption | Economical operation and high reducing agent utilization rate |
Mature and reliable technology | Since its commercialization in the 1970s, it has become the mainstream technology for NOx removal in power plants and industrial boilers worldwide | Extensive operating experience, high system reliability, and long lifespan (catalyst typically needs replacement every 3-5 years) |
High adaptability | Applicable to various flue gas conditions, including coal-fired, gas-fired, oil-fired, waste incineration, and industrial kilns | Wide range of applications |
Main application areas
SCR technology is the absolute mainstay for NOx treatment from large stationary sources:
Power industry: Coal-fired power plants, gas-fired power plants (the earliest and most widely used field).
Industrial boilers: Self-owned boilers in industries such as steel, petrochemicals, building materials (glass, ceramics), and papermaking.
Process engineering: Process exhaust gas from nitric acid plants and chemical plants.
Waste treatment: Waste incineration power plants.
Mobile sources (diesel engines): Marine diesel engines, heavy-duty diesel trucks (vehicle-grade SCR technology, but with more complex operating conditions).
The Core Role of Honeycomb Ceramics in SCR Systems
In SCR systems, honeycomb ceramics are not the catalyst itself, but rather the core carrier of the catalyst. Their specific functions are broken down as follows:
Serving as the "skeleton" and "platform" for the active catalyst
Loading function: Its surface is coated with a layer of active material with a high specific surface area (usually TiO₂-based, loaded with active components such as V₂O₅ and WO₃). The honeycomb structure provides a huge geometric surface area, allowing sufficient active components to be loaded per unit volume, which is the foundation for achieving high reaction efficiency.
Creating low-resistance, high-efficiency fluid channels
Fluid dynamic advantages: Facing ultra-large flue gas volumes of hundreds of thousands of cubic meters per hour, the pressure drop generated by parallel straight-through channels is extremely low, significantly reducing the operating energy consumption of the system's induced draft fan. This is unmatched by other carriers such as plate and corrugated types.
Withstanding extreme operating environments
Physical strength: Capable of withstanding the long-term erosion and wear of high-speed, dust-laden flue gas.
Thermal Stability: Maintains good structural integrity under operating temperatures of 300-400°C and start-up/shutdown temperature fluctuations (typically using cordierite material due to its extremely low coefficient of thermal expansion).
Standardization and Modularization:
Cellular ceramic units of standard sizes (e.g., 150x150mm cross-section, variable length) can be manufactured and then assembled into large modules. This facilitates industrial production, quality control, and rapid on-site installation/replacement.
Summary
SCR technology is the cornerstone of modern industrial flue gas purification, and cellular ceramics are the cornerstone of SCR catalysts. Without the high-strength, low-resistance, and large-surface-area physical platform provided by the cellular ceramic carrier, even the most efficient catalytic chemistry cannot be applied to practical high-flow-rate industrial flue gas treatment scenarios. Therefore, high-performance, long-life SCR denitrification honeycomb ceramic carriers are key products with high technological barriers and high added value in the field of environmental protection materials, directly affecting the efficiency, energy consumption, and cost of the entire denitrification system. We are a Chinese honeycomb ceramic manufacturer. For more information, please contact us via email at annayu@169chem.net or WhatsApp at +8618909016373.