Comparison of periodically forced reactor networks with different switch strategies
Special Symposium - EPIC-1: European Process Intensification Conference - 1
EPIC-1: Poster Session (EPIC - Poster) - P1
Keywords: loop reactors, bifurcation analysis, spatio-temporal patterns, forced fixed bed reactors
Comparison of periodically forced reactor networks with different switch strategies
Lucia Russo1, Erasmo Mancusi2, Pietro Altimari1, Pierluca Maffettone1, Silvestro Crescitelli1
1Dipartimento d’Ingegneria Chimica Università “Federico II” Piazzale Tecchio 80, 80125 Napoli, Italy
2Facoltà di Ingegneria, Università del Sannio, Piazza Roma , 82100, Benevento, Italy
Several studies show that exothermic catalytic processes with low adiabatic temperature rise can be efficiently carried out in periodically forced reactor networks. Networks of two or more catalytic beds reactors are a promising alternative to Reverse Flow Reactors (RFRs) as they overcome washout problems typical of RFRs. In a network, the dynamic regime is reached by periodically varying the feed position according to a cyclic permutation of the reactor sequence. In this way, the heat front propagates in a virtually closed loop while keeping constant the flow direction in each reactor. In this work The dynamics of three catalytic reactor network where an exothermic irreversible reaction takes place is studied. Two different switch policies are investigated. In both cases a cyclic permutation of the feed/discharge order is implemented. In Case 1 the permutation is 1-2-3, 2-3-1, 3-1-2; in Case 2 is 1-2-3, 3-1-2, 2-3-1. The main difference between the two forcings is the following: in Case 1 the freshly fed reactor becomes the discharge reactor upon switching, on the contrary, it becomes the discharge reactor after two switches in Case 2.
We observe that the two strategies generates different spatio-temporal patterns. Such a difference results from the different spatiotemporal symmetry induced by the two switch strategies.
Their effect on the stability is studied by comparing the stability range of the T periodic regimes as the switch time is varied for different values of the feed temperatures. This analysis is conducted by a numerical continuation technique based on the spatio temporal symmetry of the forced system. For low (ambient) inlet temperature, the stability ranges of a diabatic reactor respect the criteria proposed by Sheintuch and Nekhamkina (2005) for adiabatic reactors. We observe that these criteria, cannot be applied at higher inlet temperature as a consequence of the external heat losses.
Presented Wednesday 19, 13:30 to 14:40, in session EPIC-1 Poster Session (EPIC - Poster) - P1.
