Simulations reforming

The catalyst (0.15 g) was loaded into a quartz tube reactor (internal diameter = 4 mm). The catalyst was pretreated in nitrogen at 400°C. Simulated gasoline reformate was used for the activity test of the catalyst. The composition of the simulated reformate was 36 wt% H2, 17 wt% CO2, 28 wt% N2, 17 wt% H2O, 1 wt% CO, and air was added additionally as the oxidant. The total flow rate was maintained at 100 ml/min. The test was performed over the temperature range of 120 280°C at various flow rates of inlet air. 

The experimental apparatus is consists of reformed gas feeding sections, CO PrOx reaction section in the reactor, and the analysis section with a gas chromatograph system. Simulated reformed gas composition was 75 vol.% H2, 24 vol.% CO2 and 1.0 vol.% CO. The dry reformed feed stream was fed with O2 (A.=l) into the microchannel reactor by MFC (Brooks 5850E). Water vapor (10vol.% of reformed gas) was also fed into the reactor by a s)ninge pump. 

The reactor was reduced in pure hydrogen at 400 °C for 4 h prior to introducing the feed, then 5 Non3 min-1 simulated reformate and 0.5 Non3 min4 air were fed... 

A reformate flow rate of 25-175 Ndm3 min-1, simulating methanol steam reformer product gases, and 2.5-17.5 Ndm3 min-1 air were fed to the reactors. The simulated reformate was composed of 68.9% H2, 0.6% CO, 22.4% C02, 6.9% H20 and 0.4% CH3OH, the last to simulate incomplete conversion. The carbon monoxide output of the single reactors and of both switched in series is shown in Figure 2.72. The CO output of the two reactors switched in series was <10 ppm and the optimum air volume split between the first and second reactors was determined as 70/30. 

FIGURE 27.35 Short stack durabihty testing at 70°C with simulated reformate and anode airhleed. (From 3M, www.3m.com.)... 

Prepared and evaluated several viable catalysts from the two alumina supports that showed the best performance in simulated reforming operations. 

Eleven eommereial eatalysts were tested for attrition resistanee under simulated reforming eonditions. Two alumina supports supplied by CoorsTek Ceramies (90% and 99% alumina) showed the best eombination of attrition resistance and surface area. In addition, they eonsist of alpha... 

Welk et al. from Sandia National Laboratories (SNL) (USA) [34] have intensively studied the potential applications of zeolite membranes in reforming streams separation. ZSM-5 zeolite membranes synthesized by them showed excellent performance for hydrogen separation from light gases mixture. It was reported that after a single pass through the ZSM-5 zeolite membrane, the Ha purity was enriched from 76% (simulated reforming stream) to >98%. 

The accuracy of the A a method depends on the availability of a good reference spectrum, most favourably a spectrum obtained from the blank, adsorbate free metallic snrface. Unfortunately, for in-situ measurements in a working fuel cell the situation is not so straightforward, as it is difficult to find an appropriate reference spectram where no species, or at least a controlled amount, are adsorbed on the surface. The specific measmes taken for methanol and reformate operation in a working fuel cell, i.e., when there is CO, H and 0[H] co-adsorption, are described below. More specifically, we illustrate the Ap XANES technique to follow the coverage of specific adsorbates on carbon snpported Pt and different Pt/Rn bimetallic systems in pnre H2, in simulated reformate (150 ppm CO in H2) and in direct methanol operation as a function of current in an operating PEM fuel cell. 

Chen C-Y, Lai W-H, Chen Y-K et al (2014) Characteristic studies of a PBI/H3PO4 high temperature membrane PEMFC under simulated reformate gases, hit J Hydrog Energy 39(25) 13757-13762... 

The performance of graphite composite bipolar plates in a PEFC was vahdated by assembling a 1-kW-class stack that had 60 cells. The PEFC was operated at 70°C with air (70°C moisture) and a simulated reformate gas of methane (70°C moisture) that included lOppm CO. 

The thermodynamic value of that results from dilution can be readily calculated (Gu et al. 2004). For a simulated reformate with 60 40 (v/v) H /N, the calculated concentration overpotential is 7.9 mV at 70 C and ambient pressure. This is consistent with at open circuit (Gu et al. 2004). When a load is applied, however, (more than 20 mV) is more than twice the calculated value and it is nearly a constant in the low-CD (below 0.8 A/cm ) region. With a pure feed, the only gas-phase diffusion resistance arises from water vapor that has either been added to the inlet stream (to mitigate membrane degradation) or been transported through the membrane from the cathode. With defiberate additions of an inert gas such as nitrogen, the diffusion resistance becomes more substantial because the effective diffusion coefficient of in the gas mixture m is reduced. This is known as the Maxwell-Stefan effect and can be quantified using the following approximate relationship (Bird et al. 1960) ... 

Fig. 1 Durability of a membrane electrode assembly (MEA) under unsaturated humidification conditions. T = 70°C, current density 300mA cm, Uf = 60%, Uo = 40%. Anode/cathode, simulated reformed gas (SRG) (20% CO, 10 ppm CO, balrmce)/air...

Cell performance using H2 in N2 (1 1) gas mixture or simulated reformate gas is compared in Fig. 10.11. The composition of simulated reformate was 32% H2, 13% CO, 5% CO2, and 50% N2, based on the preliminary experiment of the catalytic partial oxidation (CPOX) reforming of LPG. As shown in the figure, the differences in cell performance were smaller at lower current densities. However, performance using reformate gas was lower at higher current densities at temperatures of 600° and 700°C. The... 

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