Computational fluid dynamics study of hydrogen generation by low temperature methane reforming in a membrane reactor

Said, S.A.M.; Simakov, David S. A.; Mokheimer, Esmail M. A.; Habib, Mohamed A.; Ahmed, Shakeel; Waseeuddin, Mohammed; Román‐Leshkov, Yuriy

doi:10.1016/j.ijhydene.2015.01.024

Cited by 50 publications

(27 citation statements)

References 35 publications

(60 reference statements)

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“…At a RP of 1 bar, the methane conversion along the reformer bed was observed to decrease as the GHSV is increased as shown in Figure A. The same observation was reported in Said et al The methane conversion along the reformer bed was, however, observed to increase as the GHSV is increased for RP of 10 bar. Figure B further shows that methane conversion increases from 94.6% to approximately 100% for an increased GHSVs from 4000 h −1 to 20 000 h −1 when the RP is 10 bar.…”

Section: Resultsmentioning

confidence: 99%

Performance analysis of a membrane‐based reformer‐combustor reactor for hydrogen generation

Sanusi

Mokheimer

2018

Int J Energy Res

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Summary Hydrogen is mostly produced in conventional steam methane reforming plants. In this work, we proposed a membrane‐based reformer‐combustor reactor (MRCR) for hydrogen generation in order to improve heat recovery and overall thermal efficiency. The proposed configuration will also reduce the complexity in existing steam methane reforming (SMR) plants. The proposed MRCR comprises combustion zone, hydrogen permeate zone, and SMR zone. A computational fluid dynamics model was developed using ANSYS‐Fluent software to simulate and analyze the performance of the proposed MRCR. Results show that high hydrogen yields were observed at high reformer pressures (RPs) and low gas hourly space velocities (GHSVs). Furthermore, by increasing the steam to methane ratio and addition of excess air in the combustion side, the hydrogen yield from the MRCR decreases. This is attributed to the reduction in the effective temperature of the hydrogen membrane. High RP, low GHSV, and low steam to methane ratio that increased the hydrogen yield also decreased carbon monoxide (CO) emissions. For an increased RP from 1 to 10 bar, the CO emission decreased by about 99%. The reduction in CO emission at high RP would be attributed to the effect of water gas shift reaction in the MRCR. Results of the extensive parametric study presented in this work can be used to determine the operating conditions based on tradeoffs between hydrogen yield (mole H2/mole CH4), hydrogen production rate (kg of H2/h), allowable CO emissions, and exhaust gas temperature for other applications such as gas turbine.

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Section: Resultsmentioning

confidence: 99%

Performance analysis of a membrane‐based reformer‐combustor reactor for hydrogen generation

Sanusi

Mokheimer

2018

Int J Energy Res

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“…These reformers operate by using a hydrogen permeable membrane to remove hydrogen from the reaction zone which in turn shifts the equilibrium of the reforming reaction to allow for more methane conversion [85,86]. While designs for traditional membrane-based reformers (i.e., no solar) have been proposed and experimentally studied [87,88,89], there has not been much experimental work on the subject of solar membrane-based reformers.…”

Section: Membrane-based Solar Reformermentioning

confidence: 99%

“…While designs for traditional membrane-based reformers (i.e., no solar) have been proposed and experimentally studied [87,88,89], there has not been much experimental work on the subject of solar membrane-based reformers. Numerical studies have been done on pairing membrane-based reformers with molten salt streams heated by solar energy [78,86]. The reformer design is similar to previously discussed tubular heat exchanger reformer concepts.…”

Section: Membrane-based Solar Reformermentioning

confidence: 99%

“…In this study, steam reforming with a Pd membrane loaded with a MgO promoted Ni/Alumina catalyst is simulated [86]. Pd membranes are used because of their permeable exclusivity to hydrogen [90,91].…”

Section: Membrane-based Solar Reformermentioning

confidence: 99%

“…The simulation results show that significant increase in methane conversion can be achieved at relatively low temperatures through the use of these membrane reformers ( Figure 32). Moreover, the simulations showed that the reformer performance could be kinetically limited (due to the low activity of the Ni catalyst) or transport limited (due to hydrogen separation) depending on the operating conditions [86]. Therefore there is room for improvement in both catalyst and perme-able membrane development that can allow for better performance in these low temperature reformers.…”

Section: Membrane-based Solar Reformermentioning

confidence: 99%

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A review of solar methane reforming systems

Sheu

Mokheimer

Ghoniem

2015

International Journal of Hydrogen Energy

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125

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Because of the increasing demand for energy and the associated rise in greenhouse gas emissions, there is much interest in the use of renewable sources such as solar energy in electricity and fuels generation. One problem with solar energy, however, is that it is difficult to economically convert the radiation into usable energy at the desired locations and times, both daily and seasonally. One method to overcome this space-time intermittency is through the production of chemical fuels. In particular, solar reforming is a promising method for producing chemical fuels by reforming and/or water/carbon dioxide splitting. In this paper, a review of solar reforming systems is presented, as well as a comparison between these systems and a discussion on areas for potential innovation including chemical looping and membrane reactors. Moreover, a brief overview of catalysis in the context of reforming is presented.

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