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Show I • In cOI(j1parison with heavy fuel oil, NOx emission and smoke levels from the pyrolytic biomass oils are generally higher for the same input conditions (see Figure 3). 3. NATURAL GAS FIRING FOR GLASS MELTING FURNACES Public concern is increasing as to the environmental impact of the alleged "Greenhouse Effect" and Acid Rain. This causes many industries to consider greater utilisation of natural gas. Natural gas combustion produces a low specific C02 emission, and because it does not contain any fuel bound nitrogen or sulphur it is considered one of the most environmentally friendly fossil fuels. Due to this, increased research and development related to the application of natural gas to a broad spectrum of industrial processes has been evident world-wide. A particular area of importance is the application of natural gas to glass melting furnaces. Due to high levels of air preheat used in glass melting furnaces, flame and furnace temperatures are very high. Consequently, glass melting furnaces produce high levels of thermal NOx, typically in the range 900 to 2800 ppm (at 30/0°2), Consequently, when considering the increased utilisation of natural gas in the glass industry, NOx reduction techniques require evaluation and the effect of their implementation on heat transfer determined. ... tal ... a- ~, - ,~. - ~ 400 - • U 0.1 LO U lA Figure 3. Influence of primary zone Stoichiometry on NOx emissions U To address these problems stated above, an international consortium of gas producing and distribution companies was formed. This consortium, known as NGNOx, comprised: British -Gas pIc, Gaz de France, NV Nederlandse Gasunie, SNAM, Tokyo Gas Co Ltd and Osaka Gas Co Ltd. This consortium jointly defined and funded the research programmes NG6 and NG7 [1,4] .. In 1988, a first experimental programme, NG6, was executed in ~s work. The boundary conditions of an industrial glass - melting furnace was simulated at the semi-industrial scale and a wide range of process variables |