Process and reactor for exothermal reaction

Patent metadata

Field	Value
Publication number	US-2016257562-A1
Application number	US-201415030985-A
Country	US
Kind code	A1
Filing date	Oct 24, 2014
Priority date	Oct 28, 2013
Publication date	Sep 8, 2016
Grant date	—

Abstract

The present disclosure relates to a reactor and a method of operation for an exothermal process being catalyzed by a catalytically active material receiving a reactant gas and providing a product gas, in which said exothermal process has a heat development having a potential for thermally degrading said catalytically active material, and which exothermal process operates at a temperature at which the reactants and at least 80% or all of the products are present as gases, said method comprising the steps of a) directing the reactant gas to a first zone of a material catalytically active in the exothermal process producing an first product gas, and b) directing the first product gas to a second zone of a material catalytically active in the exothermal process producing a product gas, with the option of fully or partially by-passing either said first zone or said second zone, while directing a non-condensing gas stream having a temperature at least 50° C. lower than the product gas to said by-passed zone, wherein the choice of by-passing said zone is made based on the time of operation or a process parameter reflecting the catalytic activity of the zone of catalytically active material which is not by-passed with the associated benefit of reducing the extent of thermal deactivation of the catalytically active material, and thus increasing the overall lifetime of the catalytically active material.

First claim

1 . A method of operation for an exothermal process being catalyzed by a catalytically active material comprising a dispersed active metal compound, said process converting a reactant synthesis gas to a product gas, in which the peak temperature of said catalytically active material is at least 40% of the absolute melting temperature of said active metal compound, said method comprising the steps of
a) directing the reactant gas to a first zone of a material catalytically active in the exothermal process producing an first product gas, and b) directing the first product gas to a second zone of a material catalytically active in the exothermal process producing a second product gas, with the option of fully or partially by-passing either said first zone or said second zone, while directing a non-condensing gas stream having a temperature at least 50° C. lower than the product gas to said by-passed zone, wherein the choice of by-passing said zone is made based on the time of operation or a process parameter reflecting the catalytic activity of the zone of catalytically active material which is not by-passed.

2 . A method according to claim 1 in which a condensable compound, is present as reactant or product in a concentration resulting in a dew point above 50° C., even more preferably in a dew point above 150° C.

3 . A method according to claim 1 further comprising one or more additional steps of directing gas to zones of catalytically active material or by-passing said one or more zones, wherein the decisions of by-passing said one or more additional zones are made based on time of operation or process parameters reflecting the catalytic activity of the one or more of the other zones of material catalytically active in the exothermal process.

4 . A method according to claim 1 , wherein the parameter reflecting the catalytic activity is taken from the group of outlet gas temperature, temperature of catalytically active material, and the concentration of one or more of a reactant and a product, such as CO, CO 2 , H 2 O, CH 3 OH or CH 4 .

5 . A method according to claim 1 , wherein the exothermal process is taken from the group comprising
methanation, water gas shift reaction and methanol synthesis.

6 . A method according to claim 1 , above wherein the catalytically active material comprises zinc, cobalt, molybdenum, nickel, copper or iron, in reduced, oxide or sulfide form.

7 . A method according to claim 1 , where the exothermal process is methanation wherein the inlet temperature of the synthesis gas is in the range 300° C. to 400° C. preferably 330° C. to 360° C.

8 . A method according to claim 1 where the exothermal process is water gas shift reaction wherein the inlet temperature of the synthesis gas is in the range 180° C. to 250° C. preferably 190° C. to 210° C., or in the range 300° C. to 400° C. preferably 330° C. to 360° C.

9 . A method according to claim 1 , where the exothermal process is methanol synthesis wherein the inlet temperature of the synthesis gas is in the range 180° C. to 250° C. preferably 190° C. to 210° C.

10 . A method according to claim 1 , wherein a specific zone of catalytically active material is by-passed if the temperature approach at the exit of the active zone is less than 50° C., less than 20° C. or less than 10° C.

11 . A method according to claim 1 , in which an amount of purge gas having a flow rate less than 50%, less than 20% or less than 10% of the flow rate of reactant gas, is directed to the by-passed zones of material catalytically active in the exothermal process.

12 . A method according to claim 11 in which the purge gas comprises product gas and/or product gas having reacted further, such as at least 20%, at least 50% or at least 80%.

13 . A method according to claim 12 in which the at least an amount of the purge gas acts as a suction gas in an ejector with either pressurized steam or at least a fraction of the reactant gas being the motive gas.

14 . A reactor for an exothermal gaseous process having a reactor inlet and a reactor outlet, a first zone of catalytically active material, having a first zone inlet, and having a first zone outlet, a second zone of catalytically active material having a second zone inlet and having a second zone outlet, said reactor being configurable for directing the flow from the reactor inlet to the first zone inlet, directing the flow from the first zone outlet to the second zone inlet, and directing the flow from the second zone outlet to the reactor outlet and said reactor comprising a double blocking-gas valve configured, when said valve is open, for fully or partially by-passing said second zone, where said fully or partially by-passing of said second zone is obtained by directing all, or at least 90%, at least 80% or at least 50% of the flow from the reactor inlet to the first zone inlet, and directing the flow from the first zone outlet through said double blocking-gas valve said reactor outlet or a position downstream said reactor outlet.

Assignees

• Haldor Topsoe As

Inventors

• Stummann Troels Dahlgaard
• Andersen Niels Ulrik
• Janardhanan Madhanakrishnan
• Rostrup-Nielsen Jens R

Classifications

• C07C2523/72

  Copper · CPC title

• C01B3/16 Primary

  using catalysts · CPC title

• B01J7/00

  Apparatus for generating gases (production of inert gas mixtures B01J19/14; for generating specific gases, see the relevant subclasses, e.g. C01B, C10J {; in "air bags" on vehicles B60R21/26; for starter gas F02C7/26; blasting cartridges for producing gas under pressure F42B3/04}) · CPC title

• C07C1/044

  containing iron · CPC title

• C01B2203/0283

  containing a CO-shift step, i.e. a water gas shift step · CPC title