NOx Reduction Low-temperature Process by Belco Technologies

Application: The LoTOx low-temperature oxidation process removes NOx from flue gases in conjunction with BELCO’s EDV wet scrubbing system. Ozone is a very selective oxidizing agent; it converts relatively insoluble NO and NO2 to higher, more soluble nitrogen oxides. These oxides are easily captured in a wet scrubber that is controlling sulfur compounds and/or particulates simultaneously.

Description: In the LoTOx process, ozone is added to oxidize insoluble NO and NO2 to highly oxidized, highly soluble species of NOx that can be effectively removed by a variety of wet or semi-dry scrubbers. Ozone, a highly effective oxidizing agent, is produced onsite and on demand by passing oxygen through an ozone generator—an electric corona device with no moving parts. The rapid reaction rate of ozone with NOx results in high selectivity for NOx over other components within the gas stream.

Thus, the NOx in the gas phase is converted to soluble ionic compounds in the aqueous phase; the reaction is driven to completion, thus removing NOx with no secondary gaseous pollutants. The ozone is consumed by the process or destroyed within the system scrubber. All system components are proven, well-understood technologies with a history of safe and reliable performance.

Operating conditions: Ozone injection typically occurs in the flue-gas stream upstream of the scrubber, near atmospheric pressure and at temperatures up to roughly 150°C. For higher-temperature streams, the ozone is injected after a quench section of the scrubber, at adiabatic saturation, typically 60°C to 75°C. High-particulate saturated gas and sulfur loading (SOx or TRS) do not cause problems.

Economics: The costs for NOx control using this technology are especially low when used as a part of a multi-pollutant control scenario. Sulfurous and particulate-laden streams can be treated attractively as no pretreatment is required by the LoTOx system.

Licensor: Belco Technologies Corp.