{"id":35472,"date":"2019-05-21T02:20:18","date_gmt":"2019-05-21T02:20:18","guid":{"rendered":"\/forum\/forums\/topic\/diffusion-limitation-in-porous-catalyst-layer\/"},"modified":"2019-05-21T02:20:18","modified_gmt":"2019-05-21T02:20:18","slug":"diffusion-limitation-in-porous-catalyst-layer","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/diffusion-limitation-in-porous-catalyst-layer\/","title":{"rendered":"diffusion limitation in porous catalyst layer"},"content":{"rendered":"<p>Hi all,<\/p>\n<p><\/p>\n<p>I&#8217;ve posted a lot of threads about catalytic combustion of methane in micro-channel and a lot of difficulties have been solved by this forum members. Now I need to model last module which is internal diffusion limitation in porous catalyst layer.<\/p>\n<p><\/p>\n<p>In the cases I modeled before, I just ignored catalyst layer and assumed instantaneous diffusion of gas species. However, diffusion limitation inside porous catalyst layer is important though a lot of literature ignored it. I put the geometry including catalytic layer below:<\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/adcf4c26-90bb-40b4-94b1-a8b200eed389\/d6538687-9b67-4174-871e-aa54002154ec_geometry-with-catalyst-layer.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p>In literature, the author considered diffusion limitation by modifying species boundary equation on wash-coat-fluid interface as follows:<\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/adcf4c26-90bb-40b4-94b1-a8b200eed389\/9443bf5f-1f31-45e9-8a2d-aa54002239aa_species-equation.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p>I put all parameters in this equation as follows:<\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/adcf4c26-90bb-40b4-94b1-a8b200eed389\/801677d8-47d1-4507-8651-aa5400238907_catalytic-to-geometrical-ratio.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/adcf4c26-90bb-40b4-94b1-a8b200eed389\/f0c5ffb4-254c-432f-a687-aa540023a7e6_effectiveness-factor.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/adcf4c26-90bb-40b4-94b1-a8b200eed389\/db1c2f4b-e391-4e6a-8da2-aa540023c4db_thiele-modulus.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/adcf4c26-90bb-40b4-94b1-a8b200eed389\/b00a6dc2-1124-4ac9-814a-aa540023f34f_catalytic-area-per-volume.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/us.v-cdn.net\/6032193\/uploads\/attachments\/adcf4c26-90bb-40b4-94b1-a8b200eed389\/f1a5a22f-b876-4382-b104-aa54002424b4_effective-diffusion-coefficient.jpg?width=690&amp;upscale=false\" alt=\"\"><\/p>\n<p><\/p>\n<p>. My question is:<\/p>\n<p><\/p>\n<p>According to these equations, the author just modified the species equation on interface with an effectiveness factor, does it mean this is still a one-dimensional problem and species and temperature contour still can not be obtained from this model? However, the author also calculated catalytic surface area per wash-coat volume. By doing this, did the author just turn the surface reactions into volume reactions in fluent, which makes this a two-dimensional case?<\/p>\n<p><\/p>\n<p>This confuses me a lot. Can anybody help?<\/p>\n<p><\/p>\n<p>Best regards.<\/p>\n<p><\/p>\n<p>Weiqiang.<\/p>\n","protected":false},"template":"","class_list":["post-35472","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["7644"],"_bbp_old_topic_author_name_id":["Anonymous"],"_bbp_old_is_topic_anonymous_id":["false"],"_bbp_old_closed_status_id":["publish"],"_bbp_author_ip":[null],"_bbp_old_sticky_status_id":["normal"],"_bbp_likes_count":["0","0"],"_btv_view_count":["527"],"_bbp_subscription":["236081"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["35472"],"_bbp_forum_id":["27792"],"_bbp_engagement":["22555","156533"],"_bbp_voice_count":["2"],"_bbp_reply_count":["2"],"_bbp_last_reply_id":["85767"],"_bbp_last_active_id":["85767"],"_bbp_last_active_time":["2019-05-21 14:36:42"]},"test":"weiqiang-liu"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/35472","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/35472\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=35472"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}