Thesis (M.Eng.)--Chulalongkorn University, 2008

In this study, a thermodynamic analysis of steam reforming and autothermal reforming processes for the production of hydrogen from ethanol is performed. The aim is to determine optimal operating conditions for a hydrogen production system. Operational constraints, i.e., operating temperature and carbon formation, are taken into account. The simulation results on steam reforming and autothermal reforming show that feed stream with a high water-to-ethanol ratio is favorable for increasing hydrogen production and avoiding carbon deposition on catalyst. It is also found that at each water-to-ethanol ratio, there is an optimal temperature for steam reformer operation to provide the highest hydrogen yield. The carbon formation is favored at low operating temperatures and water-to-ethanol ratio. For autothermal reforming, a feed preheating temperature significantly affects oxygen-to-ethanol ratio; a higher preheating temperature can reduce the amount of oxygen required for preheating reactants and supplying endothermic reaction in the reformer under adiabatic condition. The carbon dioxide capture method using monoethanolamine (MEA) as solvent is studied in order to reduce carbon dioxide emission and purify hydrogen product. This process can purify hydrogen product stream from steam reforming system up to about 97 mol%