Catalyst structure employing integral heat exchange
AssigneesCatalytica, Inc., Tanaka Kikinzoku Kogyo K.K.
InventorsRalph A. D. Betta, Toru Shoji, David K. Yee, Scott A. Magno
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Abstract
This invention is an improved catalyst structure and its use in highly exothermic processes like catalytic combustion. This improved catalyst structure employs integral heat exchange in an array of longitudinally disposed, adjacent reaction passage-ways or channels, which are either catalyst-coated or catalyst-free, wherein the configuration of the catalyst-coated channels differs from the non-catalyst channels such that, when applied in exothermic reaction processes, such as catalytic combustion, the desired reaction is promoted in the catalytic channels and substantially limited in the non-catalyst channels.
Claims74
A catalyst structure comprising a heat resistant support material composed of a plurality of common walls which form a multitude of adjacently disposed longitudinal channels for passage of a flowing gaseous reaction mixture wherein at least a part of the interior surface of at least a portion of the channels is coated with a catalyst and the interior surface of the remaining channels is not coated with catalyst such that the interior surface of the catalyst-coated channels are in heat exchange relationship with the interior surface of adjacent catalyst-free channels and wherein the catalyst-coated channels have a configuration which forms a more tortuous flow passage for the reaction mixture than the flow passage formed by the catalyst-free channels.
A catalyst structure comprising a heat resistant support material composed of a plurality of common walls which form a multitude of adjacently composed longitudinal channels for passage of a gaseous reaction mixture wherein at least a part of the interior surface of at least a portion of the channels is coated with a catalyst and the interior surface of the remaining channels is not coated with catalyst such that the interior surface of the catalyst-coated channels are in heat exchange relationship with the interior surface of adjacent catalyst-free channels and wherein:
- (a) the catalyst-coated channels have a smaller average hydraulic diameter (D.sub.h) than the catalyst-free channels;
- (b) the catalyst-coated channels have a higher film heat transfer coefficient (h) than the catalyst-free channels;
- and
- (c) the catalyst-coated channels form a more tortuous flow passage for the reaction mixture than the flow passage formed by the catalyst-free channels.
A catalyst structure comprising a heat resistant support material composed of a plurality of common walls which form a multitude of adjacently disposed longitudinal channels for passage of a gaseous reaction mixture wherein at least a part of the interior surface of at least a portion of the channels is coated with a catalyst and the interior surface of the remaining channels is not coated with catalyst such that the interior surface of the catalyst-coated channels are in heat exchange relationship with the interior surface of adjacent catalyst-free channels and wherein the catalyst-coated channels have a film heat transfer coefficient (h) which is more than 1.5 times greater than the h for catalyst-free channels and the catalyst-coated channels represent from about 20% to about 80% of the total open frontal area in the catalyst structure and the catalyst-coated channels form a more tortuous flow passage for the reaction mixture than the flow passage formed by the catalyst-free channels.
A catalyst structure comprising a heat resistant support material composed of a plurality of common walls which form a multitude of adjacently disposed longitudinal channels for passage of a gaseous reaction mixture wherein at least a part of the interior surface of at least a portion of the channels it coated with a catalyst and the interior surface of the remaining channels is not coated with catalyst such that the interior surface of the catalyst-coated channels are in heat exchange relationship with the interior surface of adjacent catalyst-free channels and wherein the catalyst-coated channels have a lower average hydraulic diameter (D.sub.h) than the catalyst-free channels and the numeric ratio of average D.sub.h for the catalyst-coated channels divided by the average D.sub.h for the catalyst-free channels is mailer than the numeric ratio of open frontal area of the catalyst-coated channels divided by the open frontal area of the catalyst-free channels.
A catalyst structure comprising a heat resistant support material composed of a plurality of common walls which form a multitude of adjacently disposed longitudinal channels for passage of a reaction mixture wherein at least a part of the interior surface of at least a portion of the channels is coated with a catalyst and the interior surface of the remaining channels is not coated with catalyst such that the interior surface of the catalyst-coated channels are in heat exchange relationship with the interior surface of adjacent catalyst-free channels and wherein:
- (a) the catalyst-coated channels have a higher film heat transfer coefficient (h) than the catalyst-free channels;
- (b) the catalyst-coated channels have a smaller average hydraulic diameter (D.sub.h) than the catalyst-free channels;
- and
- (c) the numeric ratio of the average D.sub.h for the catalyst-coated channels divided by the average D.sub.h for the catalyst-free channels is smaller than the numeric ratio of the open frontal area of the catalyst-coated channels divided by the open frontal area of the catalyst-free channels.
A catalyst structure comprising a heat resistant support material composed of a plurality of common walls which form a multitude of adjacently disposed longitudinal channels for passage of a gaseous reaction mixture wherein at least a part of the interior surface of at least a portion of the channels is coated with a catalyst and the interior surface of the remaining channels is not coated with catalyst such that the interior surface of the catalyst-coated channels are in heat exchange relationship with the interior surface of adjacent catalyst-free channels and wherein:
- (a) the catalyst-coated channels have a higher film heat transfer coefficient (h) than the catalyst-free channels;
- (b) more than 50% of the total reaction mixture flow is through the catalyst-coated channels;
- and
- (c) the catalyst-coated channels form a more tortuous flow passage for the reaction mixture than the flow passage formed by the catalyst-free channels.
A catalyst structure comprising a heat resistant support material composed of a plurality of common walls which form a multitude of adjacently disposed longitudinal channels for passage of a gaseous reaction mixture wherein at least a part of the interior surface of at least a portion of the channels is coated with a catalyst and the interior surface of the remaining channels is not coated with catalyst such that the interior surface of the catalyst-coated channels are in heat exchange relationship with the interior surface of adjacent catalyst-free channels and wherein;
- (a) the catalyst-coated channels have a higher film heat transfer coefficient (h) than the catalyst-free channels by a factor greater than 1.2;
- and
- (b) more than 40%, but less than 50% of the total reaction mixture flow is through the catalyst-coated channels;
- and
- (c) the catalyst-coated channels form a more tortuous flow passage for the reaction mixture than the flow passage formed by the catalyst-free channels.
A catalyst structure comprising a heat resistant support material composed of a plurality of common walls which form a multitude of adjacently disposed longitudinal channels for passage of a gaseous reaction mixture wherein at least a part of the interior surface of at least a portion of the channels is coated with a catalyst and the interior surface of the remaining channels is not coated with catalyst such that the interior surface of the catalyst-coated channels are in heat exchange relationship with the interior surface of adjacent catalyst-free channels and-wherein:
- (a) the catalyst-coated channels have a higher film heat transfer coefficient (h) than the catalyst-free channels by a factor greater than 1.3;
- and
- (b) more than 30%, but less than 40% of the total reaction mixture flow is through the catalyst-coated channels;
- and
- (c) The catalyst-coated channels form a more tortuous flow passage for the reaction mixture than the flow passage formed by the catalyst-free.
A catalyst structure comprising a heat resistant support material composed of a plurality of common walls which form a multitude of adjacently disposed longituainal channels for passage of a gaseous reaction mixture wherein at least a part of the interior surface of at least a portion of the channels is coated with a catalyst and the interior surface of the remaining channels is not coated with catalyst such that the interior surface of the catalyst-coated channels are in heat exchange relationship with the interior surface of adjacent catalyst-free channels and wherein:
- (a) the catalyst-coated channels have a higher film heat transfer coefficient (h) than the catalyst-free channels by a factor greater than 1.5;
- and
- (b) more than 20%, but less than 30% of the total reaction mixture flow is through the catalyst-coated channels;
- and
- (c) the catalyst-coated channels form a more tortuous flow passage for the reaction mixture than the flow passage formed by the catalyst-free channels.
A catalyst structure comprising a heat resistant support material composed of a plurality of common walls which form a multitude of adjacently disposed longitudinal channels for passage of a gaseous reaction mixture wherein at least a part of the interior surface of at least a portion of the channels is coated with a catalyst and the interior surface of the remaining channels is not coated with catalyst such that the interior surface of the catalyst-coated channels are in heat exchange relationship with the interior surface of adjacent catalyst-free channels and wherein:
- (a) the catalyst-coated channels have a higher film heat transfer coefficient (h) than the catalyst-free channels by a factor greater than 2.0;
- and
- (b) more than 10%, but less than 20% of the total reaction mixture flow is through the catalyst-coated channels;
- and
- (c) the catalyst-coated channels form a more tortuous flow passage for the reaction mixture than the flow passage formed by the catalyst-free channels.
A catalyst structure comprising a heat resistant support material composed of a plurality of common walls which form a multitude of adjacently disposed longitudinal channels for passage of a combustible mixture wherein at least a part of the interior surface of at least a portion of the channels is coated with a catalyst suitable for oxidizing the combustible mixture and the, interior surface of the remaining channels are not coated with catalyst such that the interior surface of the catalyst-coated channels are in heat exchange relationship with the interior surface of adjacent catalyst-free channels and wherein:
- (a) the catalyst-coated channels have a higher film heat transfer coefficient (h) than the catalyst-free channels;
- (b) the catalyst-coated channels have a smaller average hydraulic diameter (D.sub.h) than the catalyst-free channels;
- and
- (c) the catalyst-coated channels form a more tortuous flow passage for the combustible mixture than the flow passage formed by the catalyst-free channels.
A catalyst structure comprising a heat resistant support material composed of a plurality of common walls which form a multitude of adjacently disposed longitudinal channels for passage of a combustible mixture wherein at least a part of the interior surface of at least a portion of the channels is coated with a catalyst suitable for oxidizing the combustible mixture and the interior surfaced of the remaining channels are not coated with catalyst such that the interior surface of the catalyst-coated channels are in heat exchange relationship with the interior surface of adjacent catalyst-free channels and wherein:
- (a) the catalyst-coated channels have a higher film heat transfer coefficient (h) than the catalyst-free channels;
- (b) the catalyst-coated channels have a smaller average hydraulic diameter (D.sub.h) than the catalyst-free channels;
- and
- (c) the numeric ratio of the average D.sub.h for the catalyst-coated channels divided by the average D.sub.h for the catalyst-free channels is smaller than the numeric ratio of the open frontal area of the catalyst-coated channels divided by the open frontal area of the catalyst-free channels.
A process for the combustion of a combustible mixture comprising the steps of:
- (a) mixing a fuel and an oxygen-containing gas to form a combustible mixture;
- (b) contacting the mixture with a heat resistant catalyst support composed of a plurality of common walls which form a multitude of adjacently disposed longitudinal channels for passage of the combustible mixture wherein at least a part of the interior surface of at least a portion of the channels is coated with a catalyst for the combustible mixture and the interior surface of the remaining channels is not coated with catalyst such that the interior surface of the catalyst-coated channels are in heat exchange relationship with the interior surface of adjacent catalyst-free channels and wherein:
- (i) the catalyst-coated channels have a higher film heat transfer coefficient (h) than the catalyst-free channels;
- (ii) the catalyst-coated channels have a smaller average D.sub.h than the catalyst-free channels;
- and
- (iii) the catalyst-coated channels form a more tortuous flow passage for the combustible mixture than the flow passage formed by the catalyst-free channels.
A process for the combustion of a combustible mixture comprising the steps of:
- (a) mixing a fuel and an oxygen-containing gas to form a combustible mixture;
- b) contacting the mixture with a heat resistant catalyst support composed of a plurality of common walls which form a multitude of adjacently disposed longitudinal channels for passage of the combustible mixture wherein at least a part of the interior surface of at least a portion of the channels is coated with a catalyst for the combustible mixture and the interior surface of the remaining channels is not coated with catalyst such that the interior surface of the catalyst-coated channels are in heat exchange relationship with the interior surface of adjacent catalyst-free channels and wherein;
- (i) the catalyst-coated channels have a higher film heat transfer coefficient (h) than the catalyst-free channels;
- (ii) the catalyst-coated channels have a smaller average D.sub.h than the catalyst-free channels;
- and
- (iii) the numeric ratio of average D.sub.h for the catalyst-coated channels divided by the average D.sub.h for the catalyst-free channels is smaller than the numeric ratio of open frontal area of the catalyst-coated channels divided by the open frontal area of the catalyst-free channels.
Dependencies are inferred from the claim text.