Simulation of five‐step one‐bed sorption‐enhanced reaction process

Xiu, Guohua; Soares, José Luciano; Li, Ping; Rodrigues, Alı́rio E.

doi:10.1002/aic.690481210

Cited by 73 publications

(63 citation statements)

References 56 publications

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“…22,27 The Xu and Froment steam-reforming kinetics were used previously [16][17][18][19][20]22,27,[29][30][31][32] at temperatures as low as 450°C. Previously, our group 39 also showed the same kinetics to be consistent with experimental data generated with a commercial Ni-based catalyst at temperatures as low as 450°C.…”

Section: Resultssupporting

confidence: 40%

“…They include packed-bed catalytic membrane reactors (MRs) [10][11][12][13][14][15] and, more recently, absorptive reactor (AR) processes. [16][17][18][19][20][21][22][23][24][25][26] Their potential advantages over the more conventional reformers have been widely discussed. They include (i) increasing the reactant conversion and product yield, through shifting of the equilibrium toward the products, potentially allowing one to operate under milder operating conditions (e.g., lower temperatures and pressures and reduced steam consumption), and (ii) reducing the downstream purification requirements by in situ separating from the reaction mixture the desired product hydrogen (in the case of MRs) or the undesired product CO 2 (in the case of ARs).…”

Section: Introductionmentioning

confidence: 43%

“…[16][17][18][19][20] The challenge here, however, is in matching the adsorbent properties with those of the catalytic system. Two types of adsorbents have been suggested: potassium-promoted layered-double hydroxides (LDHs), which operate stably only at lower tem-peratures (less than 500°C [25][26][27], and CaO or commercial dolomite, which can be utilized at the typical steamreforming temperatures of 650-700°C 21 but requires temperatures higher than 850°C for regeneration.…”

Section: Introductionmentioning

confidence: 50%

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Hydrogen Production via a High-Efficiency Low-Temperature Reformer

Liu¹,

Tsotsis²

2006

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Media and Process Technology Inc.ii EXECUTIVE SUMMARYFuel cells are promoted by the US government as a viable alternative for clean and efficient energy generation. It is anticipated that the fuel cell market will rise if the key technical barriers can be overcome. One of them is certainly fuel processing and purification. Existing fuel reforming processes are energy intensive, extremely complicated and capital intensive; these disadvantages handicap the scaledown of existing reforming process, targeting distributed or on-board/stationary hydrogen production applications. Our project involves the bench-scale demonstration of a high-efficiency low-temperature steam reforming process. Hydrogen production can be operated at 350 to 400ºC with our invention, as opposed to >800ºC of existing reforming. In addition, our proposed process improves the start-up deficiency of conventional reforming due to its low temperature operation.The objective of this project is to demonstrate the invented process concept via a bench scale unit and verify mathematical simulation for future process optimization study. Under this project, we have performed the experimental work to determine the adsorption isotherm, reaction kinetics, and membrane permeances required to perform the process simulation based upon the mathematical model developed by us. A ceramic membrane coated with palladium thin film fabricated by us was employed in this study. The adsorption isotherm for a selected hydrotalcite adsorbent was determined experimentally. Further, the capacity loss under cyclic adsorption/desorption was confirmed to be negligible. Finally a commercial steam reforming catalyst was used to produce the reaction kinetic parameters required for the proposed operating condition. With these input parameters, a mathematical simulation was performed to predict the performance of the invented process. According to our simulation, our invented hybrid process can deliver 35 to 55% methane conversion, in comparison with the 12 and 18-21% conversion of the packed bed and an adsorptive reactor respectively. In addition CO contamination with <10 to 120 ppm is predicted for the invented process depending upon the cycle time for the PSA type operation. In comparison, the adsorption reactor can also deliver a similar CO contaminant at the low end; however, its high end reaches as high as 300 ppm based upon the simulation of our proposed operating condition. Our experimental results for the packed bed and the membrane reactor deliver 12 and 18% conversion at 400°C, approaching the conversion by the mathematical simulation. Due to the time constraint, the experimental study on the conversion of the invented process has not been complete. However, our inhouse study using a similar process concept for the water gas shift reaction has demonstrated the reliability of our mathematical simulation for the invented process. In summary, we are confident that the invented process can deliver efficiently high purity hydrogen at a low temperature (~400°C).According to our ...

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Section: Resultssupporting

confidence: 40%

Section: Introductionmentioning

confidence: 43%

Section: Introductionmentioning

confidence: 50%

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Hydrogen Production via a High-Efficiency Low-Temperature Reformer

Liu¹,

Tsotsis²

2006

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“…1 (a)) 7) to multiple step schemes such as pressurized _ (reaction) _ evacuation _ regeneration _ partially pressurized ( Fig. 1 (b)) 8) . Many studies have been reported with the single column system, but complex systems using multiple columns have been applied to industrial processes 9) .…”

Section: P Re S S U Re S W I N G R E a C T O R I N I N T E G R A Tmentioning

confidence: 42%

Process Intensification of Dehydrogenation Reactions by Pressure Swing Reactor

Tagawa

2011

J. Jpn. Petrol. Inst.

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Integration of catalytic reaction and separation operations is important for process intensification (PI). Experimental studies on promotion of the dehydrogenation reaction using hydrogen adsorbent during catalytic dehydrogenation reaction were reviewed. The promotion effect was lost after saturation of the adsorbent, so that regeneration under reduced pressure was essential to start the reaction again. The developed reactor was the so-called pressure swing reactor (PSR) or pressure swing adsorption type reactor (PSA reactor) after the cyclic operations of pressurization and evacuation. Dehydrogenation of cyclohexane, and dehydroaromatization of n-hexane, propane and methane were investigated. Pt/Al2O3 _ CaNi5, Zn/H-ZSM-5 _ Mg51Zn20, Zn/H-ZSM-5 _ Ti fine powder, and Mo/H-ZSM-5 _ Ti fine powder catalysts showed high promotion effects. Because of the differences in reaction temperature, the recommended combination of catalyst and adsorbent varies depending on the reaction. Swing of partial pressure of hydrogen by inert purge gas regenerated the promotion effect showing the potential of the PSR for PI.

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“…Rodrigues and co-workers [46][47][48][49][50] developed a detailed mathematical model of the abovedescribed PSSER process to simulate its performance for producing fuel-cell grade hydrogen. The model simulations were also used to investigate several new operational schemes for improving the performance of the PSSER process (higher conversion and purer H 2 ).…”

Section: Clean Energy Systems and Experiences 98mentioning

confidence: 45%