Wrong-way behavior of packed-bed reactors: II. Impact of thermal dispersion

✍ Scribed by V. Pinjala; Y. C. Chen; D. Luss

• Publisher: American Institute of Chemical Engineers
• Year: 1988
• Tongue: English
• Weight: 787 KB
• Volume: 34
• Category: Article
• ISSN: 0001-1541
• DOI: 10.1002/aic.690341010

✦ Synopsis

A sudden reduction in the feed temperature of a packed-bed reactor may lead to a transient temperature rise, referred to as a wrong-way behavior. As expected, the axial dispersion of heat decreases the magnitude of the temperature excursion and prolongs the transient shift to a new steady state. In addition, the thermal dispersion may enable the wrong-way behavior to ignite a low-temperature steady state leading to a disastrous runaway of the reactor. Moreover, it may create a transient high-temperature wave, which moves initially in the upstream direction. The axial dispersion of heat can lead to some behavioral features which are qualitatively different from those of a model which ignores it. The transient temperature excursion does not exceed a value, which can be estimated by a simple analytical expression.