Sofame has invested over $750,000 in a full scale protoype in its Montreal plant, and five years of research and trials in support of this important environmental breakthrough.  The technology applies ideally to various types of gas-fired burners found in hundreds of thousands of existing industrial boilers, and also to every fossil fuel combustion process including coal. Sofame's international application for the Sofame Steam Pump® was published by the International Bureau at the WIPO, based in Geneva, Switzerland, under the Patent Cooperation Treaty. The documentation defines the invention as a water heater system wherein the amount of water and the temperature of the air are closed-loop-controlled for reducing NOx production. 

One of these Sofame systems is already being installed at a major east coast university in the United States as part of a $2 million project to reduce NOx emissions and meet new emission standards coming into force in New Jersey in 2011. 

The Sofame Steam Pump® increases boiler efficiency by about 3% on an annual basis compared to the most common competing technology, flue gas recirculating burners, which can reduce efficiency by up to 7%.  Another effect of flue gas re-circulation is increased burner fresh air, which in many older boilers causes "flame impingement" by lengthening the flame.  Some burners using flue gas recirculation may have to be turned down as a result, which can reduce boiler capacity by over 15%.  The Steam Pump water vapor injection in the burner fresh air may reduce boiler capacity by no more than 5%.

Background: In hot water boilers, coal has been largely replaced by natural gas, electricity and oil as alternative fuel sources, in part because coal is a heavy pollutant. Because they are economical, the increasing demand for fired hot water heating systems as opposed to steam boilers has increased. But all fossil fuel combustion generates amongst other things NOx, which is partly responsible for environmental problems like smog, acid rain, etc.  It is well known that by humidifying the intake air of a natural gas burner, significant energy savings and NOx reduction can be achieved. However, to remain economical, such air humidifying systems are now based on the Sofame Steam Pump® principle, where energy of the exhausted flue gases is used to warm and humidify the combustion air of the burners.

In the state of the art, such systems apply well to natural gas, bio-mass and landfill gas burners, because of the high water content of the flue gases.  The condensate obtained from cooling down these flue gases is used to warm and humidify the intake air of a burner. The energy transfer in the recovery section is greatly enhanced by the phase change of water vapor in the flue gases from vapor to liquid, and the same principles limit the temperature during transfer of energy to the burner fresh air in the evaporator section of the Sofame Steam Pump®.