scholarly journals Experimental Demonstration and Validation of Hydrogen Production Based on Gasification of Lignocellulosic Feedstock

2018 ◽  
Vol 2 (4) ◽  
pp. 61 ◽  
Author(s):  
Jürgen Loipersböck ◽  
Markus Luisser ◽  
Stefan Müller ◽  
Hermann Hofbauer ◽  
Reinhard Rauch
Keyword(s):  
Hydrogen Production ◽  
Pressure Swing Adsorption ◽  
Production Plant ◽  
Flow Sheet ◽  
Hydrogen Yield ◽  
Fuel Feed ◽  
Worldwide Production ◽  
Lignocellulosic Feedstock ◽  
Production Of Hydrogen ◽  
Pressure Swing

The worldwide production of hydrogen in 2010 was estimated to be approximately 50 Mt/a, mostly based on fossil fuels. By using lignocellulosic feedstock, an environmentally friendly hydrogen production route can be established. A flow sheet simulation for a biomass based hydrogen production plant was published in a previous work. The plant layout consisted of a dual fluidized bed gasifier including a gas cooler and a dust filter. Subsequently, a water gas shift plant was installed to enhance the hydrogen yield and a biodiesel scrubber was used to remove tars and water from the syngas. CO2 was removed and the gas was compressed to separate hydrogen in a pressure swing adsorption. A steam reformer was used to reform the hydrocarbon-rich tail gas of the pressure swing adsorption and increase the hydrogen yield. Based on this work, a research facility was erected and the results were validated. These results were used to upscale the research plant to a 10 MW fuel feed scale. A validation of the system showed a chemical efficiency of the system of 60% and an overall efficiency of 55%, which indicates the high potential of this technology.

Bio-electrochemical production of hydrogen and electricity from organic waste

2021 ◽  
Author(s):  
Giorgia De Gioannis ◽  
Alessandro Dell'Era ◽  
Aldo Muntoni ◽  
Mauro Pasquali ◽  
Alessandra Polettini ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Electron Flow ◽  
Dark Fermentation ◽  
Electrochemical Process ◽  
Integrated System ◽  
Galvanic Cell ◽  
Hydrogen Yield ◽  
Cell Coupling ◽  
Production Of Hydrogen ◽  
Acid Metabolites

Abstract This study investigated the performance of a novel integrated bio-electrochemical system for synergistic hydrogen production from a process combining a dark fermentation reactor and a galvanic cell. The operating principle of the system is based on the electrochemical conversion of protons released upon dissociation of the acid metabolites of the biological process and is mediated by the electron flow from the galvanic cell, coupling biochemical and electrochemical hydrogen production. Accordingly, the galvanic compartment also generates electricity. Four different experimental setups were designed to provide a preliminary assessment of the integrated bio-electrochemical process and identify the optimal configuration for further tests. Subsequently, dark fermentation of cheese whey was implemented both in a stand-alone biochemical reactor and in the integrated bio-electrochemical process. The integrated system achieved a hydrogen yield in the range 75.5 – 78.8 N LH2/kg TOC, showing a 3 times improvement over the biochemical process.

Internal Reforming SOFC System for Flexible Coproduction of Hydrogen and Power

2005 ◽  
Author(s):  
Kas Hemmes ◽  
Anish Patil ◽  
Nico Woudstra
Keyword(s):  
Fuel Cell ◽  
Hydrogen Production ◽  
Natural Gas ◽  
Total System ◽  
Flow Sheet ◽  
Content Increase ◽  
Fuel Utilization ◽  
Production Mode ◽  
Internal Reforming ◽  
Production Of Hydrogen

In the framework of the project Greening of Gas, in which the feasibility of mixing hydrogen into the natural gas network in the NL is studied, we are exploring alternative hydrogen production methods. Fuel cells are usually only seen as devices that convert hydrogen into power and heat. It is less well known that these electrochemical energy converters can produce hydrogen, or form an essential component in systems for co-production of hydrogen and power. Co-production of hydrogen and power from NG in an Internal reforming fuel cell (IR FC) is worked out by flow sheet calculations on an Internal reforming Solid Oxide fuel cell (IR-SOFC) system. It is shown that the system can operate in a wide range of fuel utilization values at least from 60% representing highest hydrogen production mode to 95% corresponding to ‘normal’ fuel cell operation mode. For the atmospheric pressure system studied here hydrogen and CO content increase up to 22.6 and 13.5 % respectively at a fuel utilization of 60%. Total system efficiency (power + H2/CO) is increasing significantly at lower fuel utilization and can reach 94 %. Our study confirms that the calculations of Vollmar et al1) on an IR-SOFC stack also hold for a complete FC system. Notably that paradoxically a system with the same fuel cell stack when switched to hydrogen production mode can yield more power in addition to the H2 and CO produced. This is because the hydrogen production mode allows for operation at high current and power densities. The same system can double its power output (e.g. from 1.26 MW to 2.5 MW) while simultaneously increasing the H2 /CO output to 3.1MW). Economics of these systems is greatly improved. These systems can also be considered for hydrogen production for the purpose of mixing it with natural gas in the natural gas grid in order to reduce CO2 emissions at the end users, because of the ability to adopt the system rapidly to fluctuations in natural gas/hydrogen demand.

scholarly journals Influence of silica–alumina support ratio on H2 production and catalyst carbon deposition from the Ni-catalytic pyrolysis/reforming of waste tyres

2017 ◽  
Vol 35 (10) ◽  
pp. 1045-1054 ◽  
Author(s):  
Yeshui Zhang ◽  
Yongwen Tao ◽  
Jun Huang ◽  
Paul Williams
Keyword(s):  
Hydrogen Production ◽  
Catalyst Support ◽  
Coke Formation ◽  
H2 Production ◽  
Hydrogen Yield ◽  
Alumina Support ◽  
Production Of Hydrogen ◽  
Waste Tyres ◽  
Silica Alumina ◽  
Multi Walled Carbon Nanotubes

The influence of catalyst support alumina–silica in terms of different Al2O3 to SiO2 mole ratios containing 20 wt.% Ni on the production of hydrogen and catalyst coke formation from the pyrolysis-catalysis of waste tyres is reported. A two-stage reactor system was used with pyrolysis of the tyres followed by catalytic reaction. There was only a small difference in the total gas yield and hydrogen yield by changing the Al2O3 to SiO2 mole ratios in the Ni-Al2O3/SiO2 catalyst. The 1:1 ratio of Al2O3:SiO2 ratio produced the highest gas yield of 27.3 wt.% and a hydrogen production of 14.0 mmol g-1tyre. Catalyst coke formation decreased from 19.0 to 13.0 wt.% as the Al2O3:SiO2 ratio was changed from 1:1 to 2:1, with more than 95% of the coke being filamentous-type carbon, a large proportion of which was multi-walled carbon nanotubes. Further experiments introduced steam to the second-stage reactor to investigate hydrogen production for the pyrolysis-catalytic steam reforming of the waste tyres using the 1:1 Al2O3/SiO2 nickel catalyst. The introduction of steam produced a marked increase in total gas yield from ~27 wt. % to ~58 wt.%; in addition, hydrogen production was increased to 34.5 mmol g-1 and there was a reduction in catalyst coke formation to 4.6 wt.%.

Thermodynamic possibilities and constraints of pure hydrogen production by a chromium, nickel, and manganese-based chemical looping process at lower temperatures

2007 ◽  
Vol 61 (2) ◽  
Author(s):  
K. Svoboda ◽  
A. Siewiorek ◽  
D. Baxter ◽  
J. Rogut ◽  
M. Punčochář
Keyword(s):  
Hydrogen Production ◽  
Manganese Oxides ◽  
Point Of View ◽  
Steam Oxidation ◽  
Pure Hydrogen ◽  
Hydrogen Yield ◽  
Nickel Aluminum ◽  
Reducing Conditions ◽  
Production Of Hydrogen ◽  
Oxidation By Water

AbstractThe reduction of chromium, nickel, and manganese oxides by hydrogen, CO, CH4, and model syngas (mixtures of CO + H2 or H2 + CO + CO2) and oxidation by water vapor has been studied from the thermodynamic and chemical equilibrium point of view. Attention was concentrated not only on the convenient conditions for reduction of the relevant oxides to metals or lower oxides at temperatures in the range 400–1000 K, but also on the possible formation of soot, carbides, and carbonates as precursors for the carbon monoxide and carbon dioxide formation in the steam oxidation step. Reduction of very stable Cr2O3 to metallic Cr by hydrogen or CO at temperatures of 400–1000 K is thermodynamically excluded. Reduction of nickel oxide (NiO) and manganese oxide (Mn3O4) by hydrogen or CO at such temperatures is feasible. The oxidation of MnO and Ni by steam and simultaneous production of hydrogen at temperatures between 400 and 1000 K is a difficult step from the thermodynamics viewpoint. Assuming the Ni—NiO system, the formation of nickel aluminum spinel could be used to increase the equilibrium hydrogen yield, thus, enabling the hydrogen production via looping redox process. The equilibrium hydrogen yield under the conditions of steam oxidation of the Ni—NiO system is, however, substantially lower than that for the Fe—Fe3O4 system. The system comprising nickel ferrite seems to be unsuitable for cyclic redox processes. Under strongly reducing conditions, at high CO concentrations/partial pressures, formation of nickel carbide (Ni3C) is thermodynamically favored. Pressurized conditions during the reduction step with CO/CO2 containing gases enhance the formation of soot and carbon-containing compounds such as carbides and/or carbonates.

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