Natural gas furnaces used for residential heating applications are important sources of acidic condensates and emissions of nitrogen oxides, hydrocarbons and other pollutants of environmental consequence. Add-on acidic gas reduction (AGR) technology developed at U.S. Oak Ridge National Laboratory (ORNL) addresses this pollution problem by removing more than 99.9% of acidic gases and other emissions to produce an ultraclean natural gas furnace.

A 400-hour reliability and durability evaluation demonstrated the effectiveness of an AGR catalyst enclosed in a metal housing and installed on a standard commercially available high-efficiency condensing furnace. The approach almost completely removed harmful emissions from flue gas and produced a nonacidic condensate with a neutral pH level.

The ultraclean condensing high-efficiency natural gas furnace incorporates add-on technology to remove more than 99.9% of acidic gases and other emissions. Source: Jill Hemman/ORNL

The researchers relied on neutron computed tomography equipment at ORNL’s High Flux Isotope Reactor to inspect the internal condition and soot distribution of the post-test AGR without damaging the device’s gas flow-through channels. This neutron imaging and mapping capability provided details about how flue gas flowed through the AGR and about soot particle distribution. Such data can aid in improving future AGR component designs and emission control efficiency.

The AGR technology described in Chemical Engineering Journal can also be added to other natural gas-driven equipment such as water heaters, commercial boilers and industrial furnaces.