Book•
Chemical and catalytic reaction engineering
01 Jan 1976-
About: The article was published on 1976-01-01 and is currently open access. It has received 529 citations till now. The article focuses on the topics: Catalytic cycle & Catalysis.
Citations
More filters
TL;DR: In this paper, the production of H2 and CO by catalytic partial oxidation of CH4 in air at atmospheric pressure has been examined over Pt and Pt-Rh coated monoliths at residence times between 10−4 and 1−2 sec.
536 citations
TL;DR: In this paper, the authors summarized and reviewed a great deal of information from the literature on dispersion in packed beds, and provided empirical correlations for the prediction of the dispersion coefficients (D T and D L) over the entire range of practical values of Sc and Pem.
Abstract: The phenomenon of dispersion (transverse and longitudinal) in packed beds is summarized and reviewed for a great deal of information from the literature. Dispersion plays an important part, for example, in contaminant transport in ground water flows, in miscible displacement of oil and gas and in reactant and product transport in packed bed reactors. There are several variables that must be considered, in the analysis of dispersion in packed beds, like the length of the packed column, viscosity and density of the fluid, ratio of column diameter to particle diameter, ratio of column length to particle diameter, particle size distribution, particle shape, effect of fluid velocity and effect of temperature (or Schmidt number). Empirical correlations are presented for the prediction of the dispersion coefficients (D
T and D
L) over the entire range of practical values of Sc and Pem, and works on transverse and longitudinal dispersion of non-Newtonian fluids in packed beds are also considered.
436 citations
Cites background from "Chemical and catalytic reaction eng..."
...Some books on chemical reaction engineering [25, 53, 147] treat the topic of dispersion (longitudinal and lateral) in detail and it is generally observed that the data for liquids and gases do not overlap, even in the ‘‘appropriate’’ dimensionless representation....
[...]
TL;DR: It is suggested that terebellimorph polychaetes may use the CSTR to overcome digestive-rate constraints imposed by diffusion limitations; asteroids and ophiuroids may use a variety of foraging modes to obtain the highest-quality foods available.
Abstract: Chemical-reactor theory recognizes three ideal reactor types: batch reactors, which are filled with reactants, continuously stirred during the reaction, and then emptied of products after a given reaction period; plug-flow reactors (PFR's), in which reactants continuously enter and products continuously exit with no mixing along the flow path; and continuous-flow, stirred-tank reactors (CSTR's), in which reactants continuously enter and products continuously leave a stirred vessel. Performance equations for these reactors, together with kinetic models for simple enzymatic catalysis and microbially mediated (autocatalytic) digestive fermentation, reveal necessary functional relationships among initial concentrations of the limiting food component, gut volume, throughput time or gut holding time, and digestive reaction kinetics. We use these models to suggest optimization constraints for digestion, analogous to those of optimal foraging theory. Two general predictions are possible. To sustain the greatest d...
390 citations
TL;DR: In this paper, an elementary reaction mechanism of diamond growth by a vapor deposition process is proposed, which is consistent with the macroscopic views of the Russian researchers and is in general agreement with the numerous experimental observations reported in the literature.
Abstract: An elementary-reaction mechanism of diamond growth by a vapor deposition process is proposed. The central postulate is that the main monomer growth species is acetylene. The mechanism basically consists of two alternating steps: surface activation by H abstraction of a hydrogen atom from a surface carbon and the addition of one or two acetylene molecules. During the addition reaction cycle a number of solid C–C bonds is formed and hydrogen atoms migrate from a lower to an upper surface layer. The mechanism is in general agreement with the macroscopic views of the Russian researchers and is consistent with the numerous experimental observations reported in the literature.
344 citations
TL;DR: In this article, the rate of CO2 hydrogenation on Ni/SiO2 was measured as a function of H2 and CO2 partial pressures at 500-600 K, 140 kPa, and 30,000-90,000 h−1.
313 citations