Performance characteristics of a miniaturised chemical looping steam reformer for hydrogen enrichment of fuels (original) (raw)

Hydrogen production in a 5 kW Diesel Oxidative Steam Reformer

a Fundación CIDAUT. Parque Tecnológico de Boecillo, P. 209, 47151 Boecillo (Valladolid) Telf: ABSTRACT: This paper presents a reformer prototype for the production of the necessary H2 to supply a 5 kW PEMFC and its first results. The fuel processor consists of an OSR and a WGS and a PROX reactors. The design of the system was carried out with a one-dimensional model [1,2]. The mixture chamber was specially studied with a CFD code (Fluent®), taking into account the effect of fuel evaporation and the cool flame process. The aim of the designed facility is to be able of characterising each component and controlling each working parameter. Eventually, using diesel as fuel, results from the mixture chamber, OSR, WGS and PROX reactors are presented. It also includes conclusions and future works.

Thermodynamic analysis of hydrogen production via Sorption Enhanced Chemical-Looping Reforming

Dissertação para obtenção do Grau de Mestre em Engenharia Mecânica, 2011

Hydrogen production via Sorption-Enhanced Chemical-Looping reforming combines hydrocarbons reforming (in this case methane reforming) by chemical-looping auto-thermal reforming, with watergas shift and carbonation reactions. Both H2 production rate and concentration depend on the chemical equilibrium that is established in the fuel reactor and that is influenced by several parameters (temperature, pressure, H2O/CH4 content and presence/absence of CaO). This report focus its attention, in a first part, on understanding, through an Aspen Plus model, the influence that those parameters have on the equilibrium composition, as well as in the thermal optimization of the process, so that no heat demand occurs. In a second part, experiments were carried out, in a bench-scale fluidized bed reactor, in order to demonstrate the feasibility of this process, as well as the effects created by some of those previously mentioned parameters. For the thermodynamically balanced system it was possible to produce a high purity H2 (> 95%) at 650°C and 5 atm, using a H2O/CH4 ratio of 2. At these conditions, the process efficiency was 77,8% and the CO2 capture rate of 95,0%. In the experimental part it was possible to demonstrate de advantages of mixing oxygen carrier particles with CO2 sorbents, in order to enhance the H2 production specially at low temperatures (600 °C).