Novel process and catalytic materials for converting CO2 and H2 containing mixtures to liquid fuels and chemicals

2015 ◽  
Vol 183 ◽  
pp. 197-215 ◽  
Author(s):  
Nora Meiri ◽  
Yakov Dinburg ◽  
Meital Amoyal ◽  
Viatcheslav Koukouliev ◽  
Roxana Vidruk Nehemya ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
High Performance ◽  
Reaction Rates ◽  
Operating Conditions ◽  
Reactor System ◽  
Liquid Fuels ◽  
High Productivity ◽  
Carbide Phases ◽  
Production Of Hydrogen ◽  
Higher Hydrocarbons

Carbon dioxide and water are renewable and the most abundant feedstocks for the production of chemicals and fungible fuels. However, the current technologies for production of hydrogen from water are not competitive. Therefore, reacting carbon dioxide with hydrogen is not economically viable in the near future. Other alternatives include natural gas, biogas or biomass for the production of carbon dioxide, hydrogen and carbon monoxide mixtures that react to yield chemicals and fungible fuels. The latter process requires a high performance catalyst that enhances the reverse water-gas-shift (RWGS) reaction and Fischer–Tropsch synthesis (FTS) to higher hydrocarbons combined with an optimal reactor system. Important aspects of a novel catalyst, based on a Fe spinel and three-reactor system developed for this purpose published in our recent paper and patent, were investigated in this study. Potassium was found to be a key promoter that improves the reaction rates of the RWGS and FTS and increases the selectivity of higher hydrocarbons while producing mostly olefins. It changed the texture of the catalyst, stabilized the Fe–Al–O spinel, thus preventing decomposition into Fe3O4 and Al2O3. Potassium also increased the content of Fe5C2 while shifting Fe in the oxide and carbide phases to a more reduced state. In addition, it increased the relative exposure of carbide iron on the catalysts surface, the CO2 adsorption and the adsorption strength. A detailed kinetic model of the RWGS, FTS and methanation reactions was developed for the Fe spinel catalyst based on extensive experimental data measured over a range of operating conditions. Significant oligomerization activity of the catalyst was found. Testing the pelletized catalyst with CO2, CO and H2 mixtures over a range of operating conditions demonstrated its high productivity to higher hydrocarbons. The composition of the liquid (C5+) was found to be a function of the potassium content and the composition of the feedstock.

Production of High-Purity Hydrogen and Carbon Dioxide Capture by Sorption Enhanced WGS Reaction Process

2014 ◽  
Vol 906 ◽  
pp. 118-124
Author(s):  
Cheng Tung Chou ◽  
Yu Jie Huang ◽  
Hong Sung Yang
Keyword(s):  
Carbon Dioxide ◽  
High Purity ◽  
Electrical Power ◽  
Method Of Lines ◽  
Spline Approximation ◽  
Reaction Rates ◽  
Operating Conditions ◽  
Reaction Process ◽  
Wgs Reaction ◽  
High Purity Hydrogen

Global warming has become more and more serious, which is caused by greenhouse gases. Cutting down the emission of CO2 has already become one of the major research target in the world. This study is numerically investigating Thermal Swing Sorption Enhanced Reaction Process on water gas shift (WGS) reaction by Na2O-promoted alumina. According to Le Chateliers law, the forward reaction rates and conversion can be increased by removing some products selected. Therefore, this concept can be used to generate product of high-purity hydrogen. The purified H2 can be sent to gas turbine for generating electrical power or can be used for other energy source. Carbon dioxide can also be recovered and sequestrated to reduce greenhouse gas effects. The method of lines is utilized in simulation, combined with upwind differences, cubic spline approximation and LSODE of ODEPACK software to solve the problem. The concentration, temperature, and adsorption quantity in the bed are integrated with respect to time by LSODE of ODEPACK software. The simulation is stopped when the system reaches a cyclic steady state. In this study, we first simulate breakthrough curve of Na2O-promoted alumina cited from literatures to prove the accuracy of simulation program. The optimal operating conditions of the WGS TSA (temperature swing adsorption) single-bed six-process is obtained by varying operating variables, such as feed time and rinse time. Furthermore, WGS TSA single-bed six-process could achieve 99.89% purity of H2 (dry-basis) as the top product and 90.95% purity and 98.22% recovery of CO2 (dry-basis) as the bottom product.

Assessing the effect of light intensity and light wavelength spectra on the photoreduction of formic acid using a graphene oxide material

2020 ◽  
Vol 18 (8) ◽  
Author(s):  
Luis A. Ramos-Huerta ◽  
Lotte Laureys ◽  
Alexis G. Llanos ◽  
Patricio J. Valadés ◽  
Richard S. Ruiz ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Graphene Oxide ◽  
Light Intensity ◽  
Formic Acid ◽  
Reaction Rates ◽  
Operating Conditions ◽  
Initial Reaction ◽  
Oxide Material ◽  
Methanol Production ◽  
Effect Of Light

AbstractPhotocatalysis has been a topic of interest in recent years for both, oxidation and reduction reactions, and although there is a broad variety of research regarding photocatalytic materials and the reaction itself, studies on reactor design and related phenomena, radiation transfer and its direct impact on reaction extent specifically, are usually neglected. From this end, the present work focuses on the elucidation of the effect of light intensity and wavelength spectra in the visible light region during the photoreduction reaction of formic acid using graphene oxide as a promising catalyst. By using formic acid, one of the main intermediaries in the photoreduction of carbon dioxide, the possibility of methanol production is evaluated without the thermodynamic constraints presented by carbon dioxide. A graphene oxide material, synthetized through a modified Hummer’s method, is assessed for the reduction of formic acid evaluating four different light sources (red, green, blue and white). An analysis of energy balances in the reaction set-up allows the determination of both the energy absorbed by the GO photocatalyst and isoactinity conditions at studied radiative operating conditions. At an isoactinity environment, the adsorption rate of formic acid and production rate of methanol are then evaluated, relating them to the absorbed energy achieved at the wavelength spectra and light intensities evaluated; IR spectroscopy is utilized to follow formic acid concentration as well as methanol production. The largest initial reaction rate (ca. 57%) relates to the use of the red wavelength at its largest intensity. Reaction rates at larger times start to be apparent being affected by adsorption, reaction and radiation conditions. The maximum conversion, 14%, is attained by using the white wavelength spectra at its lowest intensity. Thus, higher intensities will not necessarily yield higher conversions, nor the highest reaction rates. This, in turn, poses the necessity of quick, reliable assessments for whichever catalyst used in this type of reactions that leads to the correct election of operating conditions that maximize the product yield. Independent evaluation for every wavelength within the visible spectra and assessing carbon dioxide photoreduction are future steps into the elucidation of solar fuel production feasibility.

Hydrogen Production in Fluidized Beds with In-Situ Membranes

2005 ◽  
Vol 3 (1) ◽  
Author(s):  
John Grace ◽  
Said S.E.H. Elnashaie ◽  
C. Jim Lim
Keyword(s):  
Hydrogen Production ◽  
Process Intensification ◽  
Operating Conditions ◽  
Membrane Reactors ◽  
Energy Integration ◽  
Key Factors ◽  
High Productivity ◽  
Production Of Hydrogen ◽  
Alternative Feedstocks

Fluidized Bed Membrane Reactors (FBMR) offer significant advantages for steam reforming and the production of hydrogen. Potential advantages include higher yields by reducing thermodynamic equilibrium limitations, process intensification by combining three vessels into one, reduced temperatures of operation, countering the adverse effects of pressure, virtually eliminating catalyst diffusional limitations, high productivity per unit volume of reformer, and flexibility in using alternative feedstocks. Realization of the FBMR process for hydrogen production requires that a number of unusual challenges in reactor design be met. This paper discusses the technical challenges and outlines key factors which are being addressed in providing the membranes, reactor configuration and integrity, catalyst, energy integration and operating conditions needed to establish an economically viable FBMR process.

Selective CO2 reduction towards a single upgraded product: a minireview on multi-elemental copper-free electrocatalysts

2021 ◽  
Author(s):  
Madeleine K. Wilsey ◽  
Connor P. Cox ◽  
Ryland C. Forsythe ◽  
Luke R. McCarney ◽  
Astrid M. Müller
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Greenhouse Gas ◽  
High Performance ◽  
Co2 Reduction ◽  
Anthropogenic Climate Change ◽  
Liquid Fuels ◽  
Elemental Copper ◽  
Reduction Catalysts

Electrocatalytic conversion of the greenhouse gas carbon dioxide to liquid fuels or upgraded chemicals is a critical strategy to mitigate anthropogenic climate change. To this end, we urgently need high-performance CO2 reduction catalysts.

Operability and Efficiency Performance of Ultra-Compact, High Gravity (g) Combustor Concepts

2006 ◽  
Author(s):  
J. Zelina ◽  
R. T. Greenwood ◽  
D. T. Shouse
Keyword(s):  
High Performance ◽  
Fuel Injection ◽  
Parametric Design ◽  
Reaction Rates ◽  
Combustion Efficiency ◽  
Operating Conditions ◽  
Turbine Engine ◽  
Wide Range ◽  
Efficiency Performance ◽  
Combustion Systems

Future gas turbine engines are required to be more capable than their predecessors. This often implies severe demands on the engine that translate into increasing compressor and combustor exit temperatures, higher combustion pressures and higher fuel/air ratio combustors with greater turn-down ratios (wider operating limits between idle and maximum power conditions). Major advances in combustor technology are required to meet the conflicting challenges of improving performance, increasing durability and maintaining cost. Unconventional combustor configurations are one promising approach to address these challenges. Ultra-short combustors to minimize residence time, with special flame-holding mechanisms to cope with increased through-velocities are likely in the future. Engine cycles other than the standard Brayton cycle may also be used for special applications in order to avoid the use of excessive combustion temperatures, and to extract additional power from the system. This paper focuses on vortex-stabilized combustor technologies that can enable the design of compact, high-performance combustion systems. Compact combustors weigh less and take up less volume in space-limited turbine engine for aero applications. This paper presents a parametric design study of the Ultra-Compact Combustor (UCC), a novel design based on TVC work that uses high swirl in a circumferential cavity to enhance reaction rates via high cavity g-loading on the order of 3000 g’s. Increase in reaction rates translates to a reduced combustor volume. Three combustor geometric features were varied during experiments which included (1) high-g cavity flame-holding method, (2) high-g cavity to main airflow transport method, and (3) fuel injection method. Experimental results are presented for these combustor configurations and results have shown promise for advanced engine applications. Lean blowout fuel-air ratio limits at 25–50% the value of current systems were demonstrated. Combustion efficiency was measured over a wide range of UCC operating conditions. This data begins to build the design space required for future engine designs that may use these novel, compact, high-g combustion systems.

Characterization of a Polymeric Membrane for the Separation of Hydrogen in a Mixture with CO2

2016 ◽  
Vol 9 (1) ◽  
pp. 126-136 ◽  
Author(s):  
Dionisio H. Malagón-Romero ◽  
Alexander Ladino ◽  
Nataly Ortiz ◽  
Liliana P. Green
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Production ◽  
Test Performance ◽  
Low Cost ◽  
Time Lag ◽  
Polymeric Membrane ◽  
Biological Processes ◽  
Scanning Calorimetry ◽  
Environmentally Sustainable ◽  
Production Of Hydrogen

Hydrogen is expected to play an important role as a clean, reliable and renewable energy source. A key challenge is the production of hydrogen in an economically and environmentally sustainable way on an industrial scale. One promising method of hydrogen production is via biological processes using agricultural resources, where the hydrogen is found to be mixed with other gases, such as carbon dioxide. Thus, to separate hydrogen from the mixture, it is challenging to implement and evaluate a simple, low cost, reliable and efficient separation process. So, the aim of this work was to develop a polymeric membrane for hydrogen separation. The developed membranes were made of polysulfone via phase inversion by a controlled evaporation method with 5 wt % and 10 wt % of polysulfone resulting in thicknesses of 132 and 239 micrometers, respectively. Membrane characterization was performed using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), atomic force microscopy (AFM), and ASTM D882 tensile test. Performance was characterized using a 23 factorial experiment using the time lag method, comparing the results with those from gas chromatography (GC). As a result, developed membranes exhibited dense microstructures, low values of RMS roughness, and glass transition temperatures of approximately 191.75 °C and 190.43 °C for the 5 wt % and 10 wt % membranes, respectively. Performance results for the given membranes showed a hydrogen selectivity of 8.20 for an evaluated gas mixture 54% hydrogen and 46% carbon dioxide. According to selectivity achieved, H2 separation from carbon dioxide is feasible with possibilities of scalability. These results are important for consolidating hydrogen production from biological processes.

High-performance anion exchange membrane alkaline seawater electrolysis

2021 ◽  
Author(s):  
Yoo Sei Park ◽  
Jooyoung Lee ◽  
Myeong-Je Jang ◽  
Juchan Yang ◽  
Jae Hoon Jeong ◽  
...  
Keyword(s):  
Anion Exchange ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
High Performance ◽  
Anion Exchange Membrane ◽  
Hydrogen Energy ◽  
Highly Active ◽  
Production Of Hydrogen ◽  
Exchange Membrane ◽  
Seawater Electrolysis

Seawater electrolysis is a promising technology for the production of hydrogen energy and seawater desalination. To produce hydrogen energy through seawater electrolysis, highly active electrocatalysts for the oxygen evolution reaction...

scholarly journals Sonochemical and Sonoelectrochemical Production of Energy Materials

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 284
Author(s):  
Faranak Foroughi ◽  
Jacob J. Lamb ◽  
Odne S. Burheim ◽  
Bruno G. Pollet
Keyword(s):  
Reaction Rates ◽  
Surface Cleaning ◽  
Energy Materials ◽  
Fast Reaction ◽  
Ultrasound Frequency ◽  
Production Of Hydrogen ◽  
Scientists And Engineers ◽  
Electrocatalyst Materials ◽  
Made In ◽  
Semiconductor Photocatalyst

Sonoelectrochemistry is the combination of ultrasound and electrochemistry which provides many advantages in electrochemistry, such as fast reaction rates, surface cleaning and activation, and increased mass transport at an electrode. Due to the advantages, some efforts have been made in order to benefit sonoelectrochemistry in the field of energy and environmental engineering. This review paper highlights the developed progress of the application of sonoelectrochemistry in the production of hydrogen, electrocatalyst materials and electrodes for fuel cells and semiconductor photocatalyst materials. This review also provides the experimental methods that are utilized in several sonoelectrochemical techniques, such as different set-ups generally used for the synthesis of energy-related materials. Different key parameters in the operation of sonoelectrochemical synthesis including ultrasonication time, ultrasound frequency and operation current have been also discussed. There are not many research articles on the sonoelectrochemical production of materials for supercapacitors and water electrolyzers which play crucial roles in the renewable energy industry. Therefore, at the end of this review, some articles which have reported the use of ultrasound for the production of electrocatalysts for supercapacitors and electrolyzers have been reviewed. The current review might be helpful for scientists and engineers who are interested in and working on sonoelectrochemistry and electrocatalyst synthesis for energy storage and energy conversion.

Photooxidation at Platinum Colloidal TiO2 Aqueous-Solution Interfaces. I. Ethylenediaminetetraacetic Acid and Related-Compounds

1986 ◽  
Vol 39 (5) ◽  
pp. 757 ◽  
Author(s):  
DN Furlong ◽  
D Wells ◽  
WHF Sasse
Keyword(s):  
Carbon Dioxide ◽  
Aqueous Solution ◽  
Ethylenediaminetetraacetic Acid ◽  
Oxidation Potential ◽  
Illumination Time ◽  
Carbonium Ions ◽  
Production Of Hydrogen ◽  
Glycine Derivatives ◽  
Lactic Acids ◽  
Exhaustive Oxidation

The photooxidation of ethylenediaminetetraacetic acid ( edta ) and related glycine derivatives, at Pt/TiO2/aqueous solution interfaces, has been monitored via the production of hydrogen and carbon dioxide. Yields are consistent with the exhaustive oxidation of methoxycarbonyl groups and the rate varied with the number and distribution of such groups. A photooxidation pathway is proposed which involves the oxidation of intermediate carbonium ions. Plausible molecular intermediates, such as formic acid and formaldehyde in the case of edta , have been shown in separate experiments to be photooxidized according to the proposed pathway. The maximum rate of oxidation for each donor depends on its oxidation potential and its tendency to adsorb on TiO2 surfaces. Desorption due to pH increase, as well as consumption of the donor, causes the rate to decline rapidly with illumination time. Acetic and malonic acids gave some hydrogen but underwent mainly (> c. 80%) photo-Kolbe decarboxylation to yield carbon dioxide and methane. By contrast the oxidation of oxomalonic, pyruvic and lactic acids proceeded mainly via a H2 producing pathway similar to that established for edta. The oxidation of pyruvic and lactic acids ceased at a yield of one mole of CO2 per mole of acid.

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