Development of a methanol reformer for fuel cell vehicles

Abstract: Vehicles powered by fuel cells are from an environmentalaspect superior to the traditional automobile using internalcombustion of gasoline. Power systems which are based upon fuelcell technology require hydrogen for operation. The ideal fuelcell vehicle would operate on pure hydrogen stored on-board.However, storing hydrogen on-board the vehicle is currently notfeasible for technical reasons. The hydrogen can be generatedon-board using a liquid hydrogen carrier such as methanol andgasoline. The objective of the work presented in this thesiswas to develop a catalytic hydrogen generator for automotiveapplications using methanol as the hydrogen carrier.The first part of this work gives an introduction to thefield of methanol reforming and the properties of a fuel cellbased power system. Paper I reviews the catalytic materials andprocesses available for producing hydrogen from methanol.The second part of this thesis consists of an experimentalinvestigation of the influence of the catalyst composition,materials and process parameters on the activity andselectivity for the production of hydrogen from methanol. InPapers II-IV the influence of the support, carrier andoperational parameters is studied. In Paper V an investigationof the catalytic properties is performed in an attempt tocorrelate material properties with performance of differentcatalysts.In the third part of the thesis an investigation isperformed to elucidate whether it is possible to utilizeoxidation of liquid methanol as a heat source for an automotivereformer. In the study which is presented in Paper VI a largeseries of catalytic materials are tested and we were able tominimize the noble metal content making the system more costefficient.In the final part of this thesis the reformer prototypedeveloped in the project is evaluated. The reformer which wasconstructed for serving a 5 kWe fuel cell had a highperformance with near 100 % methanol conversion and COconcentrations below 1 vol% in the product stream. The resultsof this part are presented in Paper VII.Keywords:methanol, fuel cell, vehicle, catalyst,copper, hydrogen, on-board, steam reforming, partial oxidation,combined reforming, oxidative steam reforming, auto-thermalreforming, zinc, zirconium, chromium, aluminium oxide,manganese, characterization, temperature programmed reduction,X-ray diffraction, chemisorption, carbon monoxide, poisoning,reformer.