This volume contains the papers presented at the Third European Symposium on electrochemical engineering "Electrochemical Engineering and Energy", held on March 23- 25, 1994 in Nancy, France. This meeting was organised by the Laboratoire des Sciences du Genie Chimique, CNRS, and the Centre de Perfectionnement des Industries Chimiques, in conjunction with the Groupe Fran ais de Genie des Procectes, the Society of Chemical Industry, Dechema, and the European Federation of Chemical Engineeling. The organisers would like to thank the members of the Scientific Committee for the careful selection and refereeing of the papers. We are grateful to all contributors for the thorough preparation of their manuscripts. Thanks are due to the International Society of Electrochemistry, District Urbain de Nancy, Region Lorraine, Electticite de France, Institut National Poly technique de Lorraine, and CNRS for their support. The meeting was devoted to the role of electrochemical engineeting and its relationship to the general issue of energy. The twenty-four papers contained here represent new research results and the potential technological developments in a variety of impOltant and relevant areas of the field. The remaining three papers are expert reviews in areas of current technological concern where electrochemical engineering can clearly be seen to have major relevance to energy policy and environmental protection.