Catalytic reactions in transport-line reactors

✍ Scribed by Philip Varghese; Arvind Varma

• Publisher: Elsevier Science
• Year: 1979
• Tongue: English
• Weight: 570 KB
• Volume: 34
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(79)85065-4

✦ Synopsis

The case of an Yreverslbk fust order cataly& reactum IS cons&red m a transport-tme reactor, wa a model wluch assumes plug flow of both the sold and gas phases, to mvesugate reactor performance as a function of malor opera-vanables Under eertam fled mechaatcai assumptions, a detaded study IS made of the effect of catalyst partacle sue on reactor convefston tINTRomJcTloN A transport-hne reactor IS one III which a reactant sohd or catalyst IS physIcally carrted (transported) through the reaction zone by a cocurrently upward flowmg reactant gas The gas velocity m such cases IS much wer than that reqmred for m~mrn~m flmdwtion, and the reactor bed IS then sad to be m a region of ddute phase transport [ l] The transport-he reactor has been gamfully employed m sltuat~ons of raprd catalyst deactivation, such as catalytic crackmg 111 the petroleum mdustry[2,3], m wlucb cases the reactor offers the attractive features of contmuous addition of fresh catalyst at the feed end, and sunultaneous withdraw1 of the deactivated catalyst, for subsequent regeneration, at the reactor exit lyst de&mation, and Investigate the effect of pticle sue on reactor performance under hopefully realistic condltlons of reactor ooeraoon Recent analyses by Pratt[4, S] have employed an adrmttedly sunphfied model of the transport-hne reactor to analytxcally predict reactor performance for ureverslble first order catalyttc reactions In hke fashion. we obtam an analvtlc solution for reactor conversion wth no cata-The tirst assumption is adrmttedly crude, particularly for the sohd phase, but It IS hoped that the model predicts correct trends with respect to udiuences of the system parameters Under these sunpbfymg assumptions, a mass balance m the gas phase yields dC lM-&=R, 2 E (0, L)