Methanol reforming reactor

Also a simulation of the flow field in the methanol-reforming reactor of Figure 2.21 by means of the finite-volume method shows that recirculation zones are formed in the flow distribution chamber (see Figure 2.22). One of the goals of the work focused on the development of a micro reformer was to design the flow manifold in such a way that the volume flows in the different reaction channels are approximately the same [113]. In spite of the recirculation zones found, for the chosen design a flow variation of about 2% between different channels was predicted from the CFD simulations. In the application under study a washcoat cata-... 

Methanol Reforming Reactors for a 200 1/14 Fuel Cell Power System... 

Pfiefer et al. are developing a methanol fuel processor system using steam reforming for a 200 Wg fuel cell based power supply. The researchers are currently working on the methanol reformer reactors, heat exchangers, combustors, and preferential oxidation reactors (Figure 23) for the system. The reactor bodies are either stainless steel or copper. 

Performance of an integrated methanol reformer combined with a FROX reactor... 

A complete methanol reforming system was constructed by coimecting the integrated reformer with a PROX reactor. Fig. 5 shows the evolution of temperature at the gas outlet of the evaporator, reformer and PROX reactor during the start-up. Temperature of the reformer became stable in 5 min after introduction of the reactant. The reformer produced hydrogen up to 1.5L/min with methanol conversion higher than 95%, enough to run a lOOW PEMFC. 

Figure 2.21 Computational domain of a multichannel reactor for methanol reforming.

Researchers at Lehigh University are developing a methanol reforming silicon reactor with a palladium membrane for a hydrogen purification system built using semiconductor fabrication techniques. The device is designed to produce hydrogen for fuel cells for portable electronic devices, such as laptop computers and cell phones. 

The next step in the processor development will be to integrate the palladium alloy membrane with the methanol steam reformer reactor. The researchers anticipate that the addition of the palladium membrane will improve the reactor performance due to in-situ hydrogen removal. 

Table 5. Methanol Steam Reforming Reactor Performance ...

At 310 °C reaction temperature, a pressure of 1.25 bar and an S/C ratio of 1.9, 80% methanol conversion was achieved in the stainless-steel reactors compared with > 90% for the copper reactor. The carbon monoxide concentration determined in the reformate was 0.5 vol.%. Lower temperature gradients were found for the copper reactor (7 K) than the stainless-steel device (18 K). Non-stationary measurements were carried out at the reformer reactors. The reaction followed the... 

Autothermal Methanol Reforming 2 [AMR 2] Micro Structured String Reactor for Autothermal Methanol Reforming... 

For reformate flow rates up to 400 Ndm3 min-1, the CO output was determined as < 12 ppm for simulated methanol. The reactors were operated at full load (20 kW equivalent power output) for -100 h without deactivation. In connection with the 20 kW methanol reformer, the CO output of the two final reactors was < 10 ppm for more than 2 h at a feed concentration of 1.6% carbon monoxide. Because the reformer was realized as a combination of steam reformer and catalytic burner in the plate and fin design as well, this may be regarded as an impressive demonstration of the capabilities of the integrated heat exchanger design for fuel processors in the kilowatt range. 

A combined evaporator and methanol reformer was developed by Park et al. [124] to power a 5 W fuel cell. However, the device was still electrically heated by heating cartridges. Both the evaporator and the reformer channels, which were identical in size, were prepared on metal sheets 200 pm thick by wet chemical etching. The channel dimensions were length 33 mm, width 500 pm and depth 200 pm. Therefore, the channels were completely etched through the sheets and the channel depth could be varied by introducing several of these sheets into the reactor. The flow distribution between the 20 channels of the device was performed by triangular inlet and outlet fields. Both devices had outer dimensions of 70 mm x 40 mm x 30 mm. 

Chen et al. [36] performed a comparison of micro structured steel and aluminum plates with a conventional monolith by varying the GHSV. Full conversion could be maintained for autothermal methanol reforming in the micro structures up to a GHSV of 40 000h 1, whereas conversion dropped to 80% at 20 000h 1 at the monolith. Even at 186 000 h, still 95% conversion could be achieved in the stainless-steel micro reactor. No significant performance differences were observed between the steel and aluminum plates. 

Methanol synthesis plants utilizing the low-pressure process currently operate at capacities of 2 x 105 to 2 x 106 metric tons per year [15]. Such installations are composed of a synthesis gas production unit, the actual methanol synthesis reactor, and a separation and purification section. The production and purification of synthesis gas accounts for 50%-80% of the total cost of methanol production, with the remaining cost associated with the actual synthesis and purification of methanol [2, 8], Although a variety of carbonaceous feedstocks can be transformed into synthesis gas, the steam reforming of natural gas (Equation [4]) is by far the most common option, especially for large plants [2, 15-16] ... 

One of your customers is a manufacturer of methanol. Her firm has several plants, with a huge production capacity. A methanol plant converts methane and water into methanol in two steps. In the first reformer reactor methane is converted into carbon monoxide and hydrogen (Figure 17-2). In the second synthesis reactor the carbon monoxide and part of... 

Although Maui gas is very low in sulphur, the incoming gas is desulphurised as a precaution against poisoning catalysts used in the process. Following desulphurisation, water, in the form of medium pressure steam, is added and the mixture passed through reformer reactor tubes which contain a nickel catalyst. The tubes are located inside the reformer furnace where the process temperature is raised to 900°C and the reaction to form synthesis gas occurs. The synthesis gas is cooled to 35°C, compressed to 100 bar, reheated and reacted at 250-300°C over a copper/zinc catalyst to form a water-methanol mixture with about 17 percent water. The methanol product is reduced in pressure and passed to the methanol-to-gasoline (MTG) plant. 

A comparison between a conventional and a TS-PFR study of methanol reforming is contained in the paper by Asprey et al. (1999) and the associated paper by Peppley (1999). Other workers have used gas phase TS-PFRs in a number of studies carried out in industry. An example of industrial work is given in Investigation of the Kinetics of Ethylbenzene Pyrolysis Using a Temperature Scanning Reactor , Domke et al. (2001). Below we present some of the results and observations from selected studies and relate them to the issues raised above. 

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