Integration of oxygen transport membranes in glass melting furnaces

Glass manufacturing is an energy-intensive process where the bulk of energy, necessary to maintain high temperatures for glass melting, usually comes from natural gas combustion. A solution for energy saving is an oxy-fuel glass furnace. This paper investigates the possible application of a membrane based oxygen separation module in glass melting furnaces. The mass and energy balances of two oxy-fuel glass furnaces have been reproduced and compared to an air-blown unit assumed as benchmark. The two oxy-fuel cases differ for the technology adopted to supply oxygen: in the first case, it is delivered by a PSA/VSA unit, whereas in the second case, oxygen is separated from a hot air stream in a membrane module integrated in a micro-gas turbine system. The assessment of the primary fuel demand of the three options highlights the superiority of the oxy-fuel glass furnace with the advanced membrane-based technology. The economic assessment, included to highlight the potential of the proposed application, outlines further advantages.