Structured catalysts for methane auto-thermal reforming in a compact thermal integrated reaction system Vincenzo Palma, Antonio Ricca * , Paolo Ciambelli Department of Industrial Engineering, University of Salerno, via Ponte Don Melillo, 84084 Fisciano, SA, Italy article info Article history: Received 15 November 2012 Accepted 15 March 2013 Available online 28 March 2013 Keywords: ATR Structured catalysts Thermal integration abstract In this work a compact catalytic reactor was analysed for the ATR of CH 4 as natural gas surrogate. Structured catalysts (commercial honeycomb and foam monoliths) performances in CH 4 processing were studied. In reactor design, great attention has been paid to the thermal integration, in order to obtain a total self-sustainability of the process avoiding additional external heat sources, and improving the plant compactness. Through a heat exchange system integrated in the reactor, water and air streams are preheated by exploiting the heat from exhaust stream, allowing to feed reactants at room temperature as well as cooling products stream at a temperature suitable for further purification stages (Water Gas Shift, Preferential Oxidation). In order to have a very comprehensive process analysis, temperatures and composition were moni- tored in 6 point along the catalytic bed. The influence of catalytic system geometry and thermal con- ductivity in the process performances were also analysed. Preliminary tests showed high thermal system efficiency, with a good hydrocarbon conversion at different operating conditions for both catalyst typologies. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction Nowadays, hydrogen was suggested as the most promising en- ergy carrier [1]: its annual world consumption is about 50 million ton (137 million kg of H 2 per day), and the demand for hydrogen is increasing rapidly. In recent years, a lot of interest was devoted to the production of hydrogen for high efficient electricity generation by fuel cells. Fuel cell is an energy-conversion device that produces electricity directly by electrochemical combination of hydrogen and oxygen. Despite the growing interest in renewable resources, due to the wide diffusion of fossil fuels and their costs relatively low, hydrocarbons fuel processing still remains the best solution in a period of transfer to a hydrogen based economy [2]. Methane (the main constituent of natural gas), due to its large abundance and high H:C ratio, has been recognized as an ideal fuel source for hydrogen production. The lack of infrastructure for hydrogen production and the unsolved hydrogen storage problem are accelerating the devel- opment of compact fuel reformers able to produce a hydrogen-rich syngas from hydrocarbons. The production of hydrogen (or syngas), to feed fuel cells in the stationary and auxiliary power units advances the R&D of small/medium-scale fuel processing system. However, the current industrial hydrogen production technology does not seem able to meet the requirement of the small-scale fuel processors. The hydrogen production by methane processing is carried out under very severe conditions due to the high stability of CH 4 molecule: high temperature (about 850  C) is needed to obtain high methane conversion and hydrogen yield. The aim of a fuel processor is to convert a hydrocarbon in a H 2 -rich stream. Typically it consists in 3 main steps: a reforming unit, in which syngas is produced by hydrocarbons, a water gas shift unit to convert CO in further H 2 , and a preferential oxidation unit, to remove any CO traces from syngas. The coupling with a fuel cell system brings some constrictions, as the quick response to the load changes and the very fast start-up and shut-down procedures. There are three primary techniques used to produce hydrogen from hydrocarbon fuels: steam reforming (SR), partial oxidation (POX), and auto-thermal reforming (ATR). The choice of the proper reforming chemistry is the starting point to design an effective reforming process. The SR is a catalytic endothermic process in which a hydrocar- bon (e.g. methane) reacts with steam to produce hydrogen and carbon monoxide: * Corresponding author. Tel.: þ39 (0)89964027. E-mail address: aricca@unisa.it (A. Ricca). Contents lists available at SciVerse ScienceDirect Applied Thermal Engineering journal homepage: www.elsevier.com/locate/apthermeng 1359-4311/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.applthermaleng.2013.03.038 Applied Thermal Engineering 61 (2013) 128e133