About this product: Hardbound. This proceedings contains the papers presented at the 9th International Symposium on Catalyst Deactivation, held in Lexington, KY, USA, on 7-10 October 2001.
About this product: Catalyst Deactivation 1997 focused on 9 key topical areas: carbon deposition and coke formation, chemicals, environmental catalysis, modeling, petroleum processing, poisoning, syngas conversion, techniques, and thermal degradation. All of these areas were well represented at the meeting; moreover, several review articles were presented that provide perspectives on new research and development thrusts. The proceedings of the meeting are organized with six review and award articles at the front of the volume followed by topical articles a keynote, 5-6 oral, and 2-3 poster papers. A list of authors is provided at the end of the book. It should be emphasized that all of the papers were ranked and reviewed by members of the Scientific Committee.
About this product: By deactivating parts of the brain, and testing the cognitive deficits, it is possible to gain incredible insights into the functions of particular brain areas. 'Virtual lesions' provides a state of the art guide to the full range of reversible deactivation techniques available. With each chapter written by experts in their respective fields, and providing evidence of the practical applications of their methods, along with potential pitfalls, the book will serve as a valuable and practical guide for future experimentation within cognitive neuroscience.
About this product: This digital document is an article from Winnipeg Free Press, published by Thomson Gale on October 19, 2007. The length of the article is 785 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser.
Citation Details Title: Fuelling better gas mileage; Cylinder deactivation makes engines more efficient.(Business) Author: Gale Reference Team Publication:Winnipeg Free Press (Magazine/Journal) Date: October 19, 2007 Publisher: Thomson Gale Page: b10
About this product: This digital document is a journal article from Chemical Engineering Journal, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.
Description: In residual oil upgrading by hydroprocessing, two types of reactor technologies namely, fixed-bed and ebullated-bed are commonly used. In this paper the deactivation behavior of catalysts in both types of units is compared based on the information obtained from the analysis of spent catalysts. In the fixed-bed unit, the concentration of vanadium deposits decreased from the entrance (first reactor) to the exit (last reactor), while, carbon content of the catalyst increased from the entrance to the exit. The loss of surface area for the catalysts in various reactors of the fixed-bed atmospheric residue desulfurization (ARDS) unit increased from the entrance to the exit. Distribution of the deposited vanadium with the catalyst pellet was also different in different reactors. Catalysts in the front-end reactors were deactivated mainly by metal deposition, while the back-end catalysts were primarily deactivated by coke deposition. The nature of the coke deposits on different catalysts was found to be significantly different by ^1^3C NMR, temperature programmed oxidation (TPO) and differential thermal analysis (TGA). Spent catalysts from the ebullated-bed reactor contained a mixture of highly fouled and partly fouled catalysts. The coke on the highly fouled spent catalyst particles was more aromatic and more condensed compared with that on the lightly fouled catalyst particles. Considerable changes in the physical dimensions of the catalyst pellets were noticed for the spent catalysts from the ebullating-bed reactor. In the ebullated-bed reactor, catalyst deactivation was caused not only by deposition of metals and carbon, but also by changes in the physical and mechanical properties of the catalyst under the dynamic conditions of the process.
About this product: This digital document is a journal article from Chemical Engineering Journal, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.
Description: The dynamic unsteady-state reactor process in a cocurrent tubular reactor with single-run reagents (continuous phase) and with multi-run catalyst (dispersed phase) has been investigated. For the temperature-dependent catalyst deactivation the reactor process has been considered in which after optimal number B of catalyst residences in the reactor the whole amount of catalyst leaves the system; then the fresh catalyst is directed to the reactor and the next B-runs cycle of the optimal process starts. The optimization problem has been formulated in which a maximum of an average (for one cycle) process profit flux is achieved by a best choice of number B of catalyst residences in the reactor and best choice of temperature profiles along tubular reactor for each catalyst run, b=1,...B, respectively. The set of parallel-consecutive reactions, A + B->R and R + B->S, with desired product R has been taken into account. The algorithms of maximum principle have been used for optimization. Optimization procedure allows for finding an optimal number of catalyst runs B for which an average process profit flux reaches a maximum for a concrete value of fresh catalyst price @l. Optimal value of B increases with @l. A shape of optimal temperature profile constitutes the effect of compromise between the overall production rate of desired reagent R (production rate in the first reaction minus disappearance rate in the second one) and the necessary savings of catalyst. The optimal solutions show that the most important influence on the optimal temperature profile is due to the need of catalyst saving; low temperatures save catalyst during its initial runs. Moreover, the optimal temperature profile is independent of fresh catalyst price @l. If optimal temperature profile for B-run reaction process is known, then, to obtain optimal profile for (B-r)-run process, it is enough to cut the initial part of optimal profile corresponding to the first r runs.
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