Non-porous Hydrogen-selective Inorganic Membranes for Methane Conversion to Higher Hydrocarbons PDF Download

Author: Eric Chen Lu
Publisher:
ISBN:
Category :
Languages : en
Pages : 294

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Author: Michael O'Neal Nutt
Publisher:
ISBN:
Category :
Languages : en
Pages : 142

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Author: Shamsuddin Ilias
Publisher:
ISBN:
Category :
Languages : en
Pages :

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In this work, asymmetric dense Pd/porous stainless steel composite membranes were fabricated by depositing palladium on the outer surface of the tubular support. The electroless plating method combined with an osmotic pressure field was used to deposit the palladium film. Surface morphology and microstructure of the composite membranes were characterized by SEM and EDX. The SEM and EDX analyses revealed strong adhesion of the plated pure palladium film on the substrate and dense coalescence of the Pd film. Membranes were further characterized by conducting permeability experiments with pure hydrogen, nitrogen, and helium gases at temperatures from 325 to 450 C and transmembrane pressure differences from 5 to 45 psi. The permeation results showed that the fabricated membranes have both high hydrogen permeability and selectivity. For example, the hydrogen permeability for a composite membrane with a 20 {micro}m Pd film was 3.02 x 10{sup -5} moles/m{sup 2}.s. Pa{sup 0.765} at 450 C. Hydrogen/nitrogen selectivity for this composite membrane was 1000 at 450 C with a transmembrane pressure difference of 14.7 psi. Steam reforming of methane is one of the most important chemical processes in hydrogen and syngas production. To investigate the usefulness of palladium-based composite membranes in membrane-reactor configuration for simultaneous production and separation of hydrogen, steam reforming of methane by equilibrium shift was studied. The steam reforming of methane using a packed-bed inert membrane tubular reactor (PBIMTR) was simulated. A two-dimensional pseudo-homogeneous reactor model with parallel flow configuration was developed for steam reforming of methane. The shell volume was taken as the feed and sweep gas was fed to the inside of the membrane tube. Radial diffusion was taken into account for concentration gradient in the radial direction due to hydrogen permeation through the membrane. With appropriate reaction rate expressions, a set of partial differential equations was derived using the continuity equation for the reaction system and then solved by finite difference method with appropriate boundary and initial conditions. An iterative scheme was used to obtain a converged solution. Membrane reactor performance was compared to that in a traditional non-membrane packed-bed reactor (PBR). Their performances were also compared with thermodynamic equilibrium values achievable in a conventional non-membrane reactor. Numerical results of the models show that the methane conversions in the PBIMTR are always higher than that in the PBR, as well as thermodynamic equilibrium conversions. For instance, at a reaction pressure of 6 atm, a temperature of 650 C, a space velocity of 900/16.0 SCCM/gm{sub cat}, a steam to methane molar feed ratio of 3.0, a sweep ratio of 0.15, the conversion in the membrane reactor is about 86.5%, while the conversion in the non-membrane reactor is about 50.8%. The corresponding equilibrium conversion is about 56.4%. The effects on the degree of conversion and hydrogen yield were analyzed for different parameters such as temperature, reactor pressure, feed and sweep flow rate, feed molar ratio, and space time. From the analysis of the model results, it is obvious that the membrane reactor operation can be optimized for conversion or yield through the choice of proper operating and design parameters. Comparisons with available literature data for both membrane and non-membrane reactors showed a good agreement.

Author: Anthony F. Sammells
Publisher: John Wiley & Sons
ISBN: 3527608583
Category : Science
Languages : en
Pages : 291

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This reference book addresses the evolution of materials for both oxygen and hydrogen transport membranes and offers strategies for their fabrication as well as their subsequent incorporation into catalytic membrane reactors. Other chapters deal with, e.g., engineering design and scale-up issues, strategies for preparation of supported thin-film membranes, or interfacial kinetic and mass transfer issues. A must for materials scientists, chemists, chemical engineers and electrochemists interested in advanced chemical processing.

Author: A Doukelis
Publisher: Elsevier
ISBN: 1782422412
Category : Technology & Engineering
Languages : en
Pages : 403

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Thanks to their outstanding hydrogen selectivity, palladium membranes have attracted extensive R&D interest. They are a potential breakthrough technology for hydrogen production and also have promising applications in the areas of thermochemical biorefining. This book summarises key research in palladium membrane technologies, with particular focus on the scale-up challenges. After an introductory chapter, Part one reviews the fabrication of palladium membranes. Part two then focuses on palladium membrane module and reactor design. The final part of the book reviews the operation of palladium membranes for synthesis gas/hydrogen production, carbon capture and other applications. Review of manufacture and design issues for palladium membranes Discussion of the applications of palladium membrane technology, including solar steam reforming, IGCC plants, NGCC plants, CHP plants and hydrogen production Examples of the technology in operation

Author:
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Languages : en
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In this project, we have successfully developed a full scale commercially ready carbon molecular sieve (CMS) based membrane for applications in H2 recovery from refinery waste and other aggressive gas streams. Field tests at a refinery pilot plant and a coal gasification facility have successfully demonstrated its ability to recovery hydrogen from hydrotreating and raw syngas respectively. High purity H2 and excellent stability of the membrane permeance and selectivity were obtained in testing conducted over>500 hours at each site. The results from these field tests as well as laboratory testing conclude that the membranes can be operated at high pressures (up to 1,000 psig) and temperatures (up to 300 C) in presence of aggressive contaminants, such as sulfur and nitrogen containing species (H2S, CO2, NH3, etc), condensable hydrocarbons, tar-like species, heavy metals, etc. with no observable effect on membrane performance. By comparison, similar operating conditions and/or environments would rapidly destroy competing membranes, such as polymeric, palladium, zeolitic, etc. Significant cost savings can be achieved through recovering H2 from refinery waste gas using this newly developed CMS membrane. Annual savings of $2 to 4MM/year (per 20,000 scfd of waste gas) can be realized by recovering the H2 for reuse (versus fuel). Projecting these values over the entire US market, potential H2 savings from refinery waste gases on the order of 750 to 1,000MM scfd and $750 to $1,000MM per year are possible. In addition to the cost savings, potential energy savings are projected to be ca. 150 to 220 tBTU/yr and CO2 gas emission reductions are projected to be ca. 5,000 to 6,500MMtons/year. The full scale membrane bundle developed as part of this project, i.e., 85 x 30 inch ceramic membrane tubes packaged into a full ceramic potting, is an important accomplishment. No comparable commercial scale product exists in the inorganic membrane field. Further, this newly developed full scale bundle concept can be extended to other thin film inorganic membrane technology (Pd, zeolite, etc), providing a potential commercialization pathway for these membrane materials that demonstrate high potential in a variety of separation applications yet remain a laboratory 'novelty' for lack of a full scale support. Overall, the project has been highly successful and all of the project objectives have been met. We have developed the first of its kind commercial scale carbon molecular sieve membrane and demonstrated its performance in field testing under aggressive operating conditions and in the presence of chemical contaminants that would rapidly destroy alternative organic and inorganic membranes. This innovative membrane permits H2 recovery from gas streams that up until now have not been successfully treated with membrane or conventional technology. Our end user participant is currently pursuing the field demonstration of this membrane for hydrogen recovery at its refinery site.

Author: H.P. Hsieh
Publisher: Elsevier
ISBN: 0080534694
Category : Technology & Engineering
Languages : en
Pages : 611

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With the recent advent of commercial ceramic membranes, inorganic membranes are receiving much attention as unique separators and reactors due to their excellent thermal and chemical stabilities. This volume provides an extensive and integrated survey of the science and technology of inorganic membranes. Various methods for making dense metal and solid electrolyte membranes and porous inorganic membranes with tortuous and nearly straight pores are provided. These inorganic membranes, ranging from ceramics to metals to inorganic polymers, can be characterized by many techniques indicative of their separation performance under idealized as well as application conditions. In addition to many commercial liquid-phase applications, inorganic membranes have been used industrially for gas diffusion and particle filtration and demonstrated for the important high-temperature gas separation and membrane reactor applications. Approximately half of the book is devoted to the subject of inorganic membrane reactors. Useful data in many tables and figures and extensive literature and patent information are given throughout the book for further study. The book is a valuable reference for researchers as well as process engineers who are involved in membrane and separation technology. Chemical engineers, chemists and material scientists should also find the text a comprehensible introduction to the subject.

Author: Ahmad Fauzi Ismail
Publisher: Springer
ISBN: 3319010956
Category : Science
Languages : en
Pages : 340

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This book describes the tremendous progress that has been made in the development of gas separation membranes based both on inorganic and polymeric materials. Materials discussed include polymer inclusion membranes (PIMs), metal organic frameworks (MOFs), carbon based materials, zeolites, as well as other materials, and mixed matrix membranes (MMMs) in which the above novel materials are incorporated. This broad survey of gas membranes covers material, theory, modeling, preparation, characterization (for example, by AFM, IR, XRD, ESR, Positron annihilation spectroscopy), tailoring of membranes, membrane module and system design, and applications. The book is concluded with some perspectives about the future direction of the field.

Author: Marcello De Falco
Publisher: Springer Science & Business Media
ISBN: 0857291513
Category : Technology & Engineering
Languages : en
Pages : 244

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Membrane Reactors for Hydrogen Production Processes deals with technological and economic aspects of hydrogen selective membranes application in hydrogen production chemical processes. Membrane Reactors for Hydrogen Production Processes starts with an overview of membrane integration in the chemical reaction environment, formulating the thermodynamics and kinetics of membrane reactors and assessing the performance of different process architectures. Then, the state of the art of hydrogen selective membranes, membrane manufacturing processes and the mathematical modeling of membrane reactors are discussed. A review of the most useful applications from an industrial point of view is given. These applications include: natural gas steam reforming, autothermal reforming, water gas shift reaction, decomposition of hydrogen sulphide, and alkanes dehydrogenation. The final part is dedicated to the description of a pilot plant where the novel configuration was implemented at a semi-industrial scale. Plant engineers, researchers and postgraduate students will find Membrane Reactors for Hydrogen Production Processes a comprehensive guide to the state of the art of membrane reactor technology.

Author: Enrico Drioli
Publisher: Walter de Gruyter GmbH & Co KG
ISBN: 3110381540
Category : Technology & Engineering
Languages : en
Pages : 458

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Modern membrane science and technology aids engineers in developing and designing more efficient and environmentally-friendly processes. The optimal material and membrane selection as well as applications in the many involved industries are provided. This work is the ideal introduction for engineers working in membrane science and applications (wastewater, desalination, adsorption, and catalysis), process engineers in separation science, biologists and biochemists, environmental scientists, and most of all students. Its multidisciplinary approach also stimulates thinking of hybrid technologies for current and future life-saving applications (artificial organs, drug delivery).