Home  About us  Contact
 

Methane Reforming (methane + reforming)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

Preparation of Ni-Based Metal Monolithic Catalysts and a Study of Their Performance in Methane Reforming with CO2

CHEMSUSCHEM CHEMISTRY AND SUSTAINABILITY, ENERGY & MATERIALS, Issue 6 2008
Kai Wang
Abstract A series of Ni/SBA-15/Al2O3/FeCrAl metal monolithic catalysts with Ni loadings varying between 3,% and 16,% were prepared, and their structure was characterized by various techniques. The catalytic activity of the catalyst for methane reforming with CO2 leading to synthesis gas was evaluated using a fixed-bed reactor. The results indicate good catalytic activity of the Ni/SBA-15/Al2O3/FeCrAl samples under the reaction conditions. The catalyst with a Ni loading of 8.0,% displays excellent activity and stability at 800,°C over 1400,h time on stream. After reaction, the hexagonal mesoporous structure of SBA-15 is still present and the pore walls of SBA-15 prevent the aggregation of nickel. Interactions between NiO, SBA-15, and the Al2O3/FeCrAl support modify the redox properties of the Ni/SBA-15/Al2O3/FeCrAl catalysts. [source]

Chemical-looping combustion process: Kinetics and mathematical modeling

AICHE JOURNAL, Issue 4 2010
Ion Iliuta
Abstract Chemical Looping Combustion technology involves circulating a metal oxide between a fuel zone where methane reacts under anaerobic conditions to produce a concentrated stream of CO2 and water and an oxygen rich environment where the metal is reoxidized. Although the needs for electrical power generation drive the process to high temperatures, lower temperatures (600,800°C) are sufficient for industrial processes such as refineries. In this paper, we investigate the transient kinetics of NiO carriers in the temperature range of 600 to 900°C in both a fixed bed microreactor (WHSV = 2-4 g CH4/h/g oxygen carrier) and a fluid bed reactor (WHSV = 0.014-0.14 g CH4/h per g oxygen carrier). Complete methane conversion is achieved in the fluid bed for several minutes. In the microreactor, the methane conversion reaches a maximum after an initial induction period of less than 10 s. Both CO2 and H2O yields are highest during this induction period. As the oxygen is consumed, methane conversion drops and both CO and H2 yields increase, whereas the CO2 and H2O concentrations decrease. The kinetics parameter of the gas,solids reactions (reduction of NiO with CH4, H2, and CO) together with catalytic reactions (methane reforming, methanation, shift, and gasification) were estimated using experimental data obtained on the fixed bed microreactor. Then, the kinetic expressions were combined with a detailed hydrodynamic model to successfully simulate the comportment of the fluidized bed reactor. © 2010 American Institute of Chemical Engineers AIChE J, 2010 [source]

Process intensification aspects for steam methane reforming: An overview

AICHE JOURNAL, Issue 2 2009
Shrikant A. Bhat
Abstract Steam methane reforming (SMR) is the most widely used process in industry for the production of hydrogen, which is considered as the future generation energy carrier. Having been perceived as an important source of H2, there are abundant incentives for design and development of SMR processes mainly through the consideration of process intensification and multiscale modeling; two areas which are considered as the main focus of the future generation chemical engineering to meet the global energy challenges. This article presents a comprehensive overview of the process integration aspects for SMR, especially the potential for multiscale modeling in this area. The intensification for SMR is achieved by coupling with adsorption and membrane separation technologies, etc., and using the concept of multifunctional reactors and catalysts to overcome the mass transfer, heat transfer, and thermodynamic limitations. In this article, the focus of existing and future research on these emerging areas has been drawn. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source]

Spatial near-infrared imaging of hydroxyl band coverage on ceria-based catalysts

AICHE JOURNAL, Issue 4 2006
Farid Aiouache
Abstract High-throughput near-infrared imaging was used to distinguish catalyst activity for low-temperature methane steam-reforming. Geminal hydroxyls of reduced ceria were depicted during methane reforming at 673 K. The changes in absorbance maps under various water partial pressures showed evidence of formate intermediate formations without redox exchanges. Higher resolution was observed in absorbance change images than that of thermal images obtained from catalyst surface self-emissions. The experimental results illustrated higher activity of pure rhodium catalyst than that of bimetallic ones, likely because of the high dispersion of rhodium on the catalyst support. Moreover, the reaction was accelerated when high surface area silica was added because more reduced sites were exposed. Our filter bandwidths limited our interest in band-shift distribution of geminal hydroxyl band during the reduction process. © 2005 American Institute of Chemical Engineers AIChE J, 2006 [source]