title: Water distribution in a sorption enhanced methanation reactor by time resolved neutron imaging.
abstract: Water adsorption enhanced catalysis has been recently shown to greatly increase the conversion yield of CO2 methanation. However, the joint catalysis and adsorption process requires new reactor concepts. We measured the spatial water distribution in a model fixed bed reactor using time resolved neutron imaging. Due to the high neutron attenuation coefficient of hydrogen, the absorbed water in the sorption catalyst gives a high contrast allowing us to follow its formation and map its distribution. At the same time, the product gas was analysed by FTIR-gas analysis. The measurements provided crucial insights into the future design of sorption reactors: during the sorption enhanced reaction, a reaction front runs through the reactor. Once the extension of the reaction front reaches the exhaust, the conversion rate of sorption enhanced methanation decreases. The existence of a reaction front running through the reactor is prerequisite for a high conversion rate. We give a simple model of the experimental results, in particular the conditions, under which a reaction front is established. In particular the latter effect must be taken into account for the dimensions of a large scale reactor.
authors.affiliation: Laboratory 502 Advanced Analytical Technologies, Empa - Swiss Federal Laboratories for Materials Science & Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland. andreas.borgschulte@empa.ch.
authors.forename: A
authors.initials: A
authors.lastname: Borgschulte
authors.affiliation: Laboratory 502 Advanced Analytical Technologies, Empa - Swiss Federal Laboratories for Materials Science & Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland. andreas.borgschulte@empa.ch.
authors.forename: R
authors.initials: R
authors.lastname: Delmelle
authors.affiliation: Institute of Materials and Process Engineering (IMPE), ZHAW - Zürcher Hochschule für Angewandte Wissenschaften, Technikumstrasse 9, CH-8401 Winterthur, Switzerland.
authors.forename: R B
authors.initials: RB
authors.lastname: Duarte
authors.affiliation: Institute of Materials and Process Engineering (IMPE), ZHAW - Zürcher Hochschule für Angewandte Wissenschaften, Technikumstrasse 9, CH-8401 Winterthur, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Heel
authors.affiliation: NIAG, Paul Scherrer Institut, LNS WBBA/118, 5232 Villigen PSI, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Boillat
authors.affiliation: NIAG, Paul Scherrer Institut, LNS WBBA/118, 5232 Villigen PSI, Switzerland.
authors.forename: E
authors.initials: E
authors.lastname: Lehmann