Improvement of catalyst and heat exchanger in methanol reformer for automotive engine.

An engine fueled by reformed methanol gas offers the advantages of high thermal efficiency and clean exhaust emissions. The reformer, which recovers exhaust gas energy and decomposes methanol into a gas made up of hydrogen, carbon monoxide, etc., should be miniaturized for installation in automotive engines. The authors wish to report their results on several experiments on reformative catalysts and heat exchangers.A Pt catalyst showed higher activity than other base metal catalysts after high temperature durability testing. The activity of the Pt catalyst was improved by adding CeO, ZrO2, etc. and by reduction treatment. In regard to heat transfer surface on the exhaust gas side, it was confirmed that a high-density, low-plain fin surface requires less volume than a louver fin surface.Using these results, we developed a compact reformer of about 5 litters in volume and 8.5 kilograms in weight. Engine tests with the reformer installed showed a high thermal efficiency of up to 40.5% and clean exhaust emissions.