Zeolites direct synthesis on heat exchangers for adsorption heat pumps

Improving performances of adsorption heat pumps involves developments in adsorbent materials as well as in design of more efficient adsorbers and heat exchangers. The aim of the present work was to study some aspects of the “direct synthesis” of zeolites on metal surfaces for the preparation of coated adsorbent beds for more efficient adsorption heat pumps. Different zeolites were grown on stainless steel, copper and aluminium and the results were analysed in terms of phenomena at the zeolite–metal interface, coating thickness, adhesion properties and protective effects. Direct synthesis, indeed, has demonstrated to be a valuable technique but influenced by requirements and limitations strictly dependent on the physico–chemical interaction between the material used for support and the zeolite coating considered.