a new design for a low swirl burner is disclosed in which natural draft rather than a motorized pump is used to move a fuel - air mixture through the burner . this new design enables the burn off of gas at refineries in an environment where electric motors cannot be used because of the potential for sparks , which could trigger explosions . additional modifications to the burner , including the introduction of flue gas to the burner allows for the reduction of nox gas to meet current emission control targets , without the need for further post combustion emission control systems .