Hydrogen Production via Autothermal Reforming of Diesel Fuel

Abstract

Hydrogen, for the operation of a polymer electrolyte fuel cell, can be produced by means of autothermal reforming of liquid hydrocarbons. Experiments, especially with ATR 4, which produces a molar hydrogen stream equivalent to an electrical power in the fuel cell of 3 kW, showed that the process should be preferably run in the temperature range between 700 ° and 850 °. This ensures complete hydrocarbon conversion and avoids the formation of considerable amounts of methane and organic compounds in the product water. Experiments with commercial diesel showed promising results but insufficient long‐term stability. Experiments concerning the ignition of the catalytic reaction inside the reformer proved that within 60 s after the addition of water and hydrocarbons the reformer reached 95% of its maximum molar hydrogen flow. Measurements, with respect to reformer start‐up, showed that it takes approximately 7 min. to heat up the monolith to a temperature of 340 ° using an external heating device. Modelling is performed, aimed at the modification of the mixing chamber of ATR Type 5, which will help to amend the homogeneous blending of diesel fuel with air and water in the mixing chamber.

Planar Solid-Oxide Fuel Cell System Demonstration at UT SimCenter

“…First, coke formation can be formed immediately if liquid fuel contacts the catalyst due to the presence of aromatics in diesel and jet fuels. Second, unexpected hot-spots can be caused by the local occurrence of insufficient steam or excess oxygen if the mixing of fuel, oxygen, and steam is not homogeneous [114]. Stable and sustainable hydrogen throughput also requires homogeneous and constant mixing.…”

“…The high flow velocities and rapid temperature changes could lead to the loss of bonding between the washcoat and monolith walls. Research teams in Argonne National Laboratory [73], Royal Military College of Canada [21,125,126], Forschungszentrum Juelich GmbH in Germany [86,114,127], and KTH-RIT in Sweden [19] have done a significant amount of research of ATR in monolithic reactors. For diesel ATR in monolithic reactor, Shigarov et al [128] tested several catalyst composites and the optimum operating conditions were specified as O2/C ratio of 0.5-0.6, S/C ratio of 1.5-1.7 and inlet mixture temperature of 300-400 °C.…”

Nonlinear control of an autothermal fuel reforming system

“…Based on the ideal gas law, the following relationship can be obtained P atr = m atr RT atr M atr V atr (6) where T atr , V atr ∈ R denote the temperature and volume of the ATR, respectively, and m atr , M atr ∈ R denote the mass and average molar mass of the gas inside the ATR. After taking the time derivative of (6), the dynamics of P atr can be obtained as follows (6) was utilized to get the second term in (7) anḋ M atr term was ignored as similar as the simplifications for the water gas shift converter and preferential oxidation reactor (WROX) pressure dynamics and the anode pressure dynamics in [9].…”

“…After taking the time derivative of (6), the dynamics of P atr can be obtained as follows (6) was utilized to get the second term in (7) anḋ M atr term was ignored as similar as the simplifications for the water gas shift converter and preferential oxidation reactor (WROX) pressure dynamics and the anode pressure dynamics in [9]. In (7), W out ∈ R, denoted as the mass flow rate of the ATR outlet, can be obtained from the linearized nozzle flow equation as follow…”

“…The other main reactions, namely the water-gas shift reaction (WGS) and the methane formation (MF), also proceed simultaneously and yield a gas composition [6] as follows:…”