In the present study, a thermodynamic analysis of the autothermal reforming of dimethyl ether (DME) for the production of hydrogen was carried out. The results clearly indicated that the carbon formation behavior, the boundary conditions between coke-free and coking regions, and the equilibrium composition of the reformate were dependent on the steam/DME ratio, O-2/DME ratio, temperature, and pressure of the system. For instance, carbon formation was effectively suppressed as the steam/DME ratio increased from 0 to 5, the O-2/DME ratio increased from 0 to 3, or the temperature rose from 100 to 1000 degrees C. In contrast, carbon formation was enhanced as the pressure was increased from 0.5 to 10 atm. The boundary temperature of coke-free operation decreased with an increase in the steam/DME and O-2/DME ratios. More specifically, at a steam/DME ratio of 3-5 and an O-2/DME ratio of 0-3, the boundary temperature ranged from 50 to 280 degrees C (when CH4 formation was promoted) and 380 to 670 degrees C (when CH4 formation was suppressed), respectively. Furthermore, at elevated temperatures, H-2 and CO formations were enhanced, and CH4 formation was inhibited. The addition of steam enhanced H-2 production while reducing CO formation. On the contrary, an increase in the O-2/DME ratio reduced H-2 production while enhancing CO formation. Interestingly, the desired temperature for thermo-neutral condition, in which energy consumption was zero, can be achieved by correctly controlling the O-2/DME and steam/DME ratios. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.