NOx Control - CONCORD SCR Abatement System

The Lihuang is a unique abatement device designed as a combined (SCR) selective catalytic reduction NOx abatement system with add-on control for CO or other VOCs in one convenient and integrated package.  

LH SCR catalytic oxidizer systems can successfully abate compounds such as carbon monoxide (CO),  ammonia (NH3), hydrogen cyanide (HCN), and volatile organic compounds (VOCs) found in applications such as calciners used to manufacture catalyst.  The system also reduces the process nitrogen oxides (NOx) and the NOx formed by the oxidation of NH3 using a SCR catalyst.

What is Selective Catalytic Reduction (SCR) and when do I use it?  Click here to learn more.

CPI designs and manufactures a custom NOx Abatement System in one modular package. The CONCORD SCR System is a combined Selective Catalytic Reduction (SCR) system with add-on control for CO or other VOC's in one modular package. The CONCORD SCR System can be economically applied to many industrial and chemical processes where NOx emissions and other pollutants are of concern.

The LH SCR System is engineered to provide +90% NOx removal when operated with an ammonia injection system (dry urea, anhydrous ammonia or aqueous ammonia) and specially designed SCR Catalyst. The ammonia will be precisely sparged into the CONCORD reactor and used as a reactant over the SCR Catalyst. The resulting emissions will be nitrogen, water, and minimal ammonia (slip). One of the flexibility features of the CONCORD System is its ability economically to abate another pollutant such as CO, VOC's, or HAP. The CONCORD SCR System can be fitted to include auxiliary catalyst systems for other pollutants. The exhaust from the LH-SCR System will be used in a Recuperative Heat Exchanger to be used as energy conservation for the incoming gas stream.

NOx reduction is based on the efficient and safe control of an ammonia reactant over the NOx removal catalyst bed. A typical vapor delivery system may include the following components: Unload station, storage tank, pumping/delivery, vaporizer.

The LH SCR Abatement System incorporates a primary heat exchanger for energy conservation. Also a pre-heat burner for even catalyst temperature control, NOx abatement catalyst choices designed to convert oxides of nitrogen (NO + NO2) in the presence of ammonia to nitrogen and water vapor. Ammonia reactant used in precisely measured amounts and injected before the catalyst bed. Depending on other pollutants that may be in the off gas, a variety of optional catalyst bed choices can be integrated with the CONCORD System. Adding flexibility for carbon monoxide (CO) or other volatile organic compounds (VOC's) and hazardous air pollutants (HAP's).

The LH System starts in the catalytic reactor where our floating plate primary heat exchanger fabricated of all stainless steel. The counter flow of process exhaust gas with a clean oxidized air allows relatively cool operation at the leading edges of the plates. Designing the heat exchanger in this fashion allows the CONCORD CONOx Abatement Systems to operate with a broad range of operational flexibility.

The pre-heat burner developed for use in LH SCR Abatement Systems operating in a negative pressure environment. The burner is designed to promote mixing of the exhaust gasses with oxygen when fired horizontally into the burner chamber. This innovative design provides the highest degree of flame impingement and high-velocity mixing, leading to airflow and temperature uniformity for which CONCORD SCR Abatement Systems are known.

A specially developed NOx Removal Catalyst is used based on the exact needs of the application. There are three types of catalyst that can be considered: Zeolite Catalysts offer high-temperature operation, Vanadium/Titanium Blends offer wide range flexibility, and Precious Metal blends offer low-temperature capability. Other pollutants such as CO, VOC, or HAP can be effectively treated through the use and application of other catalyst formulations.

Abatement of NOx includes the safe and accurate control of ammonia reactant. The CONCORD SCR Removal System engineered to provide NOx removal when operated with an ammonia injection system (dry urea, anhydrous ammonia or aqueous ammonia) and specially designed SCR Catalyst. The ammonia will be precisely sparged into the CONCORD reactor and used as a reactant over the SCR Catalyst. The resulting emissions will be nitrogen, water, and minimal ammonia (slip).

Precise and accurate control of the ammonia reactant is critical to efficient NOx abatement with minimal ammonia slip. The selective catalytic reaction is simply the ionization of oxygen in the air with Hydrogen and Nitrogen molecules in the ammonia. The designed result is the reformation to harmless nitrogen (N2), and water vapor (H2O) with usable heat at low temperatures. The catalytic-induced ionization level for NOx occurs at temperatures between 450°F and 750°F. Sufficient to achieve conversion of NOx pollutants in excess of 90%. After the NOx removal catalyst, a second stage of catalyst can be used to promote additional removal of other gas stream pollutants. The exact details of the second stage reaction will be dependent on the composition of the process stream and the desired performance needs.

Auxiliary systems can be included based on the exact needs of the application. Precise ammonia reactant can be controlled via our Integral Continuous Emission Monitoring control and record keeping platform. Other components of a complete system may include ammonia delivery unload station, ammonia storage tank, pumping/delivery, and the ammonia vaporizer.

A booster fan draws the process exhaust into the system at a fixed duct static pressure, where the contaminated gasses are passed through the LH SCR Abatement System. The system is under constant negative pressure that eliminates fugitive leaks to the surrounding area. The resultant clean, gasses are released to the atmosphere. An advantage the LH System offers is multiple sources being adequately controlled in one device. The volume control and sparge control systems work together to ensure efficient operation without any impact on the performance of the process.