Experimental Investigation On Hydrogen Production By Steam Reforming Of Muti-Hydrocarbon Fuel Based On Pt/CZO/Al₂O₃ Catalyst

In recent years, the increase in global population and development of economic, have led to a great rise in world vehicle and fuel consumptions. As a consequence of the foreseen reduction in fossil resources and environmental constraints, a great interest for new energy sources has been shown. The engine thermal efficiency can be largely improved and engine pollutants, thermal and noise emissions would be further reduced by the mixed combustion of classical fuel and the hydrogen-rich reformed gas inducted into the cylinders, which produced by the fuel catalytic reforming using engine exhaust heat. In this paper, an apparatus was designed to imitate producing hydrogen-rich gas by hydrocarbon fuel steam catalytic reforming using engine exhaust heat. The reformer reactor was based on a porous ceramic substrate using Pt /CZO/ Al₂O₃ as reforming catalysts and a K-type thermal sensor controlled oven to produce energy. A bottle of argon gas used as carried gas, which controlled by mass flow meter and mass flow controller, aim to push the fuel-water steam run in the system. The reaction products were cooled by a cold-trap in order to get rid of the un-reacted water/fuel mixture. An on-line gas chromatograph was used to analyze the reaction products, which equipped with a thermal conductivity detector.This paper tested the hydrocarbon fuel steam reforming performance based on Pt/CZO/Al₂O₃ as the catalyst, using ethanol, iso-octane, 93#gasoline and 0#diesel as the reforming fuel. The influence of temperature, fuel pumping speed, carried gas flow and water/ethanol ratio were investigated. Ethanol, iso-octane, 93#gasoline, 0#diesel and water were considered reagents and H2, CO, CO2 and CH4 were considered produces.The test showed that the best ethanol steam reforming performance of hydrogen and CO selectivity were obtained from a liquid water-ethanol mixture at 600℃with water-to-ethanol ratio of 6:1, when carried gas flow was 50ml/min and mixture pumping speed was 0.4ml/min. Meanwhile, CH4 and CO2 are less produced. For iso-octane steam reforming, the best hydrogen selectivity 55% was achieved under the condition of 600℃, pumping speed 0.4ml/min, carried gas flow 50ml/min and iso-octane to water ratio at 1:24. For gasoline steam reforming, the highest H2 selectivity was only 32%, which was obtained when temperature was 700℃with mixture pumping speed at 0.2ml/min, gasoline to water ratio at 1:24 and carried gas flow 75ml/min. For diesel steam reforming, an acceptable H2 selectivity was 51%, which gained with 700℃, carried gas flow 75ml/min, mixture fuel pumping speed 0.3ml/min and diesel to water ratio at 1:24.