Reactor for conducting exothermic equilibrium reactions

Patent metadata

Field	Value
Publication number	US-10898874-B2
Application number	US-201816612631-A
Country	US
Kind code	B2
Filing date	Apr 26, 2018
Priority date	May 12, 2017
Publication date	Jan 26, 2021
Grant date	Jan 26, 2021

Abstract

A reactor for conducting exothermic equilibrium reactions, especially for the performance of methanol synthesis by heterogeneously catalysed conversion of synthesis gas, is proposed, which enables readjustment and hence optimization of the reaction conditions along the longitudinal coordinate of the reactor. For this purpose, in accordance with the invention, the reactor is divided into a multitude of series-connected reaction cells, each of which comprises a preheating zone, a cooled reaction zone, one or more cooling zones and a deposition zone for condensable reaction products. In this way, the reaction conditions are adjustable to the respective, local composition of the reaction mixture and variable over the reactor length.

First claim

The invention claimed is:

1. A reactor for conducting exothermic equilibrium reactions, in which a gaseous feed mixture is at least partly converted over a solid catalyst to a product mixture comprising at least one liquid reaction product condensable at a reactor pressure and at temperatures below a reactor temperature, the reactor comprising at least two series-connected reaction cells that are in fluid connection with one another and are arranged in a common reactor shell, wherein each reaction cell comprises the following series-connected assemblies that are in fluid connection with one another:
(a) a preheating zone suitable for heating the feed mixture or the gaseous product stream from the upstream reaction cell, wherein the preheating zone can optionally be dispensed with in the first reaction cell in flow direction of the gaseous feed mixture;
(b) at least one reaction zone comprising a catalyst active in respect of the exothermic equilibrium reaction to be conducted and a cooling apparatus in a heat-exchanging relationship with the catalyst;
(c) at least one cooling zone comprising a cooling apparatus suitable for cooling the partly converted, gaseous product stream that has been laden with condensable reaction product and exits from the reaction zone to a temperature below the dew point of this gas;
(d) a deposition zone comprising a phase separation apparatus for separation of the product stream that exits from the cooling zone into a gaseous product stream that has been freed of condensate and a condensate stream comprising liquid reaction product;
(e) means of discharging the condensate stream comprising liquid reaction product; and
(f) means of discharging the gaseous product stream that has been freed of condensate and means of feeding this gaseous product stream to a subsequent reaction cell arranged downstream and/or means of discharging the gaseous product stream from the reactor.

2. The reactor according to claim 1 , wherein the cooling zone comprises the following in assembly (c):
(c1) a first cooling zone comprising a cooling apparatus suitable for cooling the partly converted, gaseous product stream that has been laden with condensable reaction product and exits from the reaction zone to a temperature below the temperature in the reaction zone; and
(c2) a second cooling zone comprising a cooling apparatus suitable for further cooling the partly converted, precooled gaseous product stream that has been laden with condensable reaction product and exits from the first cooling zone to a temperature below the dew point of this gas.

3. The reactor according to claim 1 , wherein the shell is arranged horizontally or vertically with respect to the perpendicular imparted by gravity, wherein the flow of the gaseous feed mixture or the gaseous product stream from the upstream reaction cell through the reaction cells in both cases is vertical.

4. The reactor according to claim 1 , wherein the shell is arranged horizontally or vertically with respect to the perpendicular imparted by gravity, wherein the flow of the gaseous feed mixture or the gaseous product stream from the upstream reaction cell through the reaction cells in both cases is horizontal.

5. The reactor according to claim 4 , wherein the shell is arranged vertically with respect to the perpendicular imparted by gravity, wherein the flow of the gaseous feed mixture or the gaseous product stream from the upstream reaction cell through the reaction cells is horizontal and in radial direction.

6. The reactor according to claim 2 , wherein the preheating zone (a) and the first cooling zone (c1) coincide spatially or functionally and are in a heat-exchanging relationship with one another.

7. The reactor according to claim 1 , wherein the reaction zone (b) has been equipped with thermoplates, wherein the thermoplates consist of two sheets each bonded to one another, wherein this composite has, on its inside, a cavity which is tightly sealed from the outside and through which a fluid cooling medium flows, wherein the catalyst is present in the reaction zone in piece form or particulate form as a bed of solid material arranged between two adjacent thermoplates in each case in such a way that the gaseous feed mixture or the gaseous product stream from the upstream reaction cell can flow through it vertically or horizontally, and wherein the catalyst and the cooling medium are in an indirect heat-exchanging relationship.

8. The reactor according to claim 1 , wherein the preheating zone, the reaction zone or the cooling zones or two or more of these assemblies are executed in the form of a lamellar heat exchanger.

9. The reactor according to claim 1 , wherein the cooling medium used is hot condensate from a steam generator, wherein the cooling medium takes up at least a portion of the heat of reaction released in the reaction zone (b) and is partly evaporated, and wherein the condensate/saturated steam mixture obtained or the saturated steam is at least partly recycled to the steam generator and/or conducted as heat carrier to the preheating zone (a) of the same reaction cell.

10. The reactor according to claim 1 , wherein means are encompassed which permit at least partial recycling of the condensate/saturated steam mixture removed from one or more reaction cells or of the steam component only to a steam generator and at least partial release of the saturated steam drawn off from the steam generator as export steam to external consumers.

11. The reactor according to claim 1 , wherein means are encompassed which permit, in the preheating zone (a), the heating of the feed mixture or of the gaseous product stream from the upstream reaction cell in indirect heat exchange against hot condensate from a steam generator, to obtain a cooled hot condensate stream.

12. The reactor according to claim 1 , wherein means are encompassed which permit supply of the cooled hot condensate stream from the first cooling zone (c1), removed from the preheating zone (a), as cooling medium in a preceding reaction cell arranged upstream, followed by recycling thereof to a steam generator.

13. The reactor according to claim 1 , wherein at least some of the cooling zones and/or preheating zones are configured as plate heat exchangers with thermoplates.

14. The reactor according to claim 1 , wherein means are encompassed which permit supply of fresh feed mixture that has not yet been partly converted or individual reactants to one or more of the subsequent reaction cells arranged downstream of the first reaction cell.

15. The reactor according to claim 1 , wherein the reaction zone (b) is equipped, in at least one reaction cell, with at least two catalysts having different activity with regard to the exothermic equilibrium reaction.

16. The reactor according to claim 1 , further comprising means of feeding the condensate stream to a workup apparatus for the reaction product.

17. A process for preparing methanol, the process comprising the steps of providing the reactor according to claim 1 ; and converting a carbon dioxide-containing synthesis gas feed to methanol using the reactor.

Assignees

• Air Liquide

Inventors

• Castillo-Welter Frank
• Haag Stephane
• Frind Robert
• Schuhmann Timm
• Ochs Andreas
• Wagner Marc
• Valentin Solene

Classifications

• C07C31/04

  Methanol · CPC title

• C07C29/152 Primary

  characterised by the reactor used · CPC title

• B01J8/06

  in tube reactors; the solid particles being arranged in tubes · CPC title

• B01J8/04

  the fluid passing successively through two or more beds · CPC title

• B01J8/067

  Heating or cooling the reactor (B01J8/062 takes precedence) · CPC title