Feeding of Oxygen Along the Height of a Circulating Fast Fluidized Bed Membrane Reactor for Efficient Production of Hydrogen

2007 ◽  
Vol 85 (11) ◽  
pp. 1529-1538 ◽  
Author(s):  
M.E.E. Abashar ◽  
S.S.E.H. Elnashaie
Keyword(s):  
Fluidized Bed ◽  
Membrane Reactor ◽  
Efficient Production ◽  
Production Of Hydrogen

Comprehensive Study of Steam Reforming of Methane in Membrane Reactors

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Özgün Yücel ◽  
Mehmet Alaittin Hastaoglu
Keyword(s):  
Steam Reforming ◽  
Membrane Reactor ◽  
Design Parameters ◽  
Large Temperature ◽  
Efficient Production ◽  
Gas Mixing ◽  
Concentration Gradients ◽  
Production Of Hydrogen ◽  
Simulation Results ◽  
Steam Reforming Of Methane

A 2D model and heat transfer mechanism are proposed to analyze and study oxidative steam reforming of methane (OSRM) in a membrane reactor. The model describes mass and thermal dispersions for gas and solid phases. It also accounts for transport through the membrane. The effects of operating parameters on methane conversion and H2 yield are analyzed. The parameters considered are the bed temperature (800–1100 K), molar oxygen-to-carbon ratio (0.0–0.5), and steam-to-carbon ratio (1–4). The results show that our model prevents overestimation and provides valuable additional information about temperature and concentration gradients in membrane reactor which is not available in a simple one-dimensional approach. Simulation results show that large temperature and concentration gradients cannot be avoided. The particle properties and the bed diameter have a considerable effect on the extent of gas mixing. Effective gas mixing coefficient also increases with increasing gas and solid velocity. In membrane reactor, simulation results show that mixing which depends on operational and design parameters has a strong effect on the hydrogen conversion. Also, the removal of hydrogen with membranes breaks equilibrium barrier leading to efficient production of hydrogen, reduced reactor size, and tube lengths. The model can be used in real-time simulation of industrial reactors for control and optimization purposes.

scholarly journals Hydrogen production from water electrolysis: role of catalysts

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Shan Wang ◽  
Aolin Lu ◽  
Chuan-Jian Zhong
Keyword(s):  
Hydrogen Production ◽  
Water Splitting ◽  
Noble Metal ◽  
Active Sites ◽  
Current Knowledge ◽  
Low Cost ◽  
Critical Role ◽  
Water Electrolysis ◽  
Efficient Production ◽  
Production Of Hydrogen

AbstractAs a promising substitute for fossil fuels, hydrogen has emerged as a clean and renewable energy. A key challenge is the efficient production of hydrogen to meet the commercial-scale demand of hydrogen. Water splitting electrolysis is a promising pathway to achieve the efficient hydrogen production in terms of energy conversion and storage in which catalysis or electrocatalysis plays a critical role. The development of active, stable, and low-cost catalysts or electrocatalysts is an essential prerequisite for achieving the desired electrocatalytic hydrogen production from water splitting for practical use, which constitutes the central focus of this review. It will start with an introduction of the water splitting performance evaluation of various electrocatalysts in terms of activity, stability, and efficiency. This will be followed by outlining current knowledge on the two half-cell reactions, hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), in terms of reaction mechanisms in alkaline and acidic media. Recent advances in the design and preparation of nanostructured noble-metal and non-noble metal-based electrocatalysts will be discussed. New strategies and insights in exploring the synergistic structure, morphology, composition, and active sites of the nanostructured electrocatalysts for increasing the electrocatalytic activity and stability in HER and OER will be highlighted. Finally, future challenges and perspectives in the design of active and robust electrocatalysts for HER and OER towards efficient production of hydrogen from water splitting electrolysis will also be outlined.

scholarly journals Production and Characterization of Bio-oil from Bio-mass by Circulating Fluidized Bed Pyrolysis Reactor

1970 ◽  
Vol 46 (3) ◽  
pp. 313-322 ◽  
Author(s):  
ATMK Hasan ◽  
M Mohiuddin ◽  
MB Ahmed ◽  
IJ Poly ◽  
M Asadullah ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Biomass Conversion ◽  
Fixed Bed ◽  
Acid Value ◽  
Reactor System ◽  
Efficient Production ◽  
Bottom Part ◽  
Bio Oil ◽  
Pyrolysis Reactor

The objective of the present work is to install a modified suitable and compatible reactor system for the efficient production of renewable liquid fuel (bio-oil) from agro-based bio-mass. This new type of reactor system contains a combustor connected with the upper end of the reactor chamber. The bottom end of the reactor is connected with the bottom part of the combustor by a stainless steel pipe through which hot sand is circulated by the force of air pump. Thus, effective heat transfer from the continuously circulated heated sand as well as efficient biomass conversion into the reactor can be obtained. In this work, jute stick and bagasse abundantly available in Bangladesh were pyrolyzed separately in a continuous feeding circulating fluidized bed reactor at around 500°C for bio-oil production. The total bio-oil yields from bagasse and jute stick were about 69.5 wt% and 68.2 wt% respectively, which are higher than the yields obtained from fixed bed pyrolysis reactor. The total yields of char contents were 19.4 wt% and 21.7wt% after complete pyrolysis of bagasse and jute stick respectively, which are less than that of char yields obtained from fixed bed pyrolysis reactor. Physical and chemical analyses of bio-oils were carried out by conventional methods. The density, viscosity, pH, acid value, water, lignin, solid and ash contents of bio-oils obtained from both jute stick and bagasse were found to be 1.1 g/cc, 3.1 cp, 4.1, 126.3 mgKOH/g, 14.0 wt%, 2.5wt%, 0.05wt%, 0.03wt%, and 1.12 g/cc, 3.2cp, 4.0, 127.1 mgKOH/g, 13.0 wt%, 2.5wt%, 0.015wt%, 0.025wt%, respectively. Key words: Renewable energy; Bio-mass; Bio-oil; Pyrolysis; Fluid bed circulating reactor DOI: http://dx.doi.org/10.3329/bjsir.v46i3.9036 BJSIR 2011; 46(3): 313-322

Efficient production of Mg2Si in a fluidized-bed reactor

2012 ◽  
Vol 229 ◽  
pp. 152-161 ◽  
Author(s):  
Jun Li ◽  
Guohua Luo ◽  
Fei Wei
Keyword(s):  
Fluidized Bed ◽  
Fluidized Bed Reactor ◽  
Efficient Production

scholarly journals Ni-Co single atomic anchored conjugated microporous polymer for high-performance photocatalytic hydrogen evolution

2021 ◽  
Author(s):  
Chen Yang ◽  
Zhonghua Cheng ◽  
Giorgio Divitini ◽  
Cheng Qian ◽  
Bo Hou ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
High Performance ◽  
Efficient Production ◽  
Gaseous Diffusion ◽  
Photocatalytic Hydrogen Evolution ◽  
Conjugated Microporous Polymer ◽  
Microporous Polymer ◽  
Production Of Hydrogen ◽  
Simple Pathway

The fabrication of single atomic photocatalysts via a simple pathway is a crucial challenge to enable efficient production of hydrogen. Herein, we demonstrate a gaseous diffusion strategy to construct single...

scholarly journals Simulation study of an auto-thermal double-membrane reactor for the simultaneous production of hydrogen and methanol: comparison of two different hydrogen redistribution strategies along the reactor

2017 ◽  
Vol 19 (2) ◽  
pp. 115-124
Author(s):  
Farhad Rahmani ◽  
Mohammad Haghighi ◽  
Pooya Estifaee ◽  
Mohammad Reza Rahimpour
Keyword(s):  
Methanol Synthesis ◽  
Membrane Reactor ◽  
Synthesis Process ◽  
Pure Hydrogen ◽  
Heterogeneous Model ◽  
Double Membrane ◽  
Methanol Production ◽  
Current Configuration ◽  
Production Of Hydrogen ◽  
Counter Current

Abstract In a continuing effort to realize the simultaneous hydrogen and methanol production via the auto-thermal methanol synthesis process, the effect of two different hydrogen redistribution strategies along a double-membrane reactor has been considered. A steady-state one-dimensional heterogeneous model was developed to compare two strategies applied in the operation of the auto-thermal methanol synthesis. It was found that the counter-current configuration exhibited the better performance compared to the reactor operated in the co-current mode from both the economic and environmental points of view. This superiority is ascribed to the establishment of a more favourable temperature profile along the reactor and also more hydrogen extraction from the reaction zone. Moreover, the influence of some operating variables was investigated on the performance of the auto-thermal double-membrane reactor in the counter-current configuration. The results suggest that utilizing this configuration for pure hydrogen and methanol production could be feasible and beneficial.

Cu-Ru nanoalloys on carbon black for efficient production of hydrogen in neutral and alkaline conditions

2020 ◽  
Vol 262 ◽  
pp. 127041 ◽  
Author(s):  
Jikuan Zhao ◽  
Ting Pan ◽  
Jikang Sun ◽  
Hongtao Gao ◽  
Jinxue Guo
Keyword(s):  
Carbon Black ◽  
Efficient Production ◽  
Production Of Hydrogen ◽  
Alkaline Conditions

Conceptual Design of Sulfur-Iodine Hydrogen Production Cycle of Korea Institute of Energy Research

2008 ◽  
Author(s):  
Wonchul Cho ◽  
Kikwang Bae ◽  
Chusik Park ◽  
Changhee Kim ◽  
Kyoungsoo Kang
Keyword(s):  
Nuclear Power ◽  
Membrane Reactor ◽  
High Efficiency ◽  
Electric Energy ◽  
Extractive Distillation ◽  
Production Cycle ◽  
Thermochemical Cycle ◽  
Energy Research ◽  
Energy Agency ◽  
Production Of Hydrogen

The Sulfur-Iodine thermochemical cycle offers a promising approach to the high efficiency production of hydrogen from nuclear power. Several SI cycles have been proposed by several research group. General Atomic (GA) studied I2 separation by extractive distillation using H3PO4. RWTH introduced the concept of reactive distillation. In this process, HIx stream coming from the Bunsen reaction is fed to the column. And HIx is distillated and decomposed at the same time to obtain hydrogen. Korea Institute of Energy Research (KIER) and Japan Atomic Energy Agency (JAEA) concentrate HIx using electro-dialysis cell and concentrated HIx is fed to the column to produce HI vapor, which is decomposed to produce hydrogen. HI was separated from HIx solution by an extractive distillation using H3PO4. However, a large amount of electric energy was required to recycle H3PO4. Most of SI processes have difficulties producing hydrogen because it has excess iodine in HI decomposition Section. SI cycle with electrodialysis cell uses membrane reactor to separate H2 and HIx. The current state of the membrane technology is not compatible with the process needs. This study examined several cases of flowsheets to overcome the problems mentioned above. The flowsheets were revised by adding the iodine separator and excluding membrane reactor. The thermal efficiency of SI process was analyzed using the revised flowsheet.

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