Title of Invention	"METHOD FOR SYNTHESISING METHANOL"
Abstract	Method for synthesising methanol from hydrogen, carbon monoxide and carbon dioxide under pressure with at least one synthesis stage, which contains at least one catalyst filled methanol reactor, wherein in multiple stages at least one stage is equipped with a compressor and wherein all synthesis stages are equipped with internel product off-take for methanol and internal gas/gas-heat exchanger for transfer of heat energy of gas mixture leaving the methanol reactor to the gas mixture provided for imput in methanol reactor, characterised in that at least in one synthesis stage the gas mixture determined for the input in a catalyst Riled methanol reactor is heated directly before the addition in said methanol reactor in an additional trimming heater.

Title of Invention

"METHOD FOR SYNTHESISING METHANOL"

Abstract

Method for synthesising methanol from hydrogen, carbon monoxide and carbon dioxide under pressure with at least one synthesis stage, which contains at least one catalyst filled methanol reactor, wherein in multiple stages at least one stage is equipped with a compressor and wherein all synthesis stages are equipped with internel product off-take for methanol and internal gas/gas-heat exchanger for transfer of heat energy of gas mixture leaving the methanol reactor to the gas mixture provided for imput in methanol reactor, characterised in that at least in one synthesis stage the gas mixture determined for the input in a catalyst Riled methanol reactor is heated directly before the addition in said methanol reactor in an additional trimming heater.

Full Text	1. The invention refers to a process for methanol synthesis out of hydrogen. Carbon Monoxide and Carbon dioxide under pressure with at least one synthesis stage of, the type stated in generic term of Claim 1 as well as to a corresponding installation. A series of installations or rather processes for catalytic methanol synthesis are known wherein for the fullness of solutions here as example the DE-2117060, DE-2529591, 0E-3220995 IDE-3518362, US-2904575 and the DE-4100632 are named. From the WO 97/31707 a process is known in which a trimming heater is assembled before a corresponding gas/ gas-heat exchanger, through which the temperature difference of the latter is reduced and consequently it's area is increased. Such an area increase will be prevented through the present invention. In the WO 97/31707 also a technology is described in which the heat exchanger is integrated in the reactor, which compulsorily makes an additional heat exchanger necessary, because the reaction conditions otherwise are unstable. In the DE-4028750 of the claimant a furnace (there 6) is input for reaching the necessary reaction temperature at entry of adialiatic reactor and as indirect heater for a boiler (there 11) in the, distillation. There only a small part of the reaction heat of reactor is used for heating up reaction entry gas.. The boiler serves there only to it, to drive on the following distillation. In the DE-4004862 of claimant an additional heat exchanger 2. is described, which is indeed input there as starting heat exchanger, whose use however does not have any reduction of usual heat exchanger area as a result. As described in the DE-4100632, it is advantageous, to input more number of synthesis stages with reactors, to condense down their generated methanol, to separate from synthesis gas and to withdraw after each individual reactor as separate methanol-product flow. In the cooling down of methanol synthesis gas mixture leaving the reactor, it is economical, to utilize the given out heat at least partly, to heat up first the inlet flow in the respective reactors by means of gas/ gas-heat exchangers. It was found disadvantageous in long years of operation, that the catalytic material input in the methanol reactor usually changes it 's activity in course of time such that always higher reactor temperatures are required to obtain an optimum utilisation and wherein indeed in the zones after the gas entry areas of reactors such high reactor temperatures, after some time are no more attainable. On ground of the reduced reaction turnover less methanol as well as less steam are produced which in the cooling of methanol reactors results as enclosure product. It is the assignment of the invention to over come the mentioned disadvantageous and to procure such possibilities specially to save the heat exchanger areas and/or to increase the utilisation under special consideration of changeable catalytic activity. With a process of the type described at entry the assignment is solved as per the invention through the distinguishing features of claim 1. Therein it is provided that at least in 3. one synthesis stage the definite gas mixture determined for the input in a catalyst filled methanol reactor is heated directly before addition in the said methanol reactor in an additional trimming heater-Designs of invention exist among others therein that - the temperature of gas mixture determined for the input in the catalyst filed reactors is measured after it's heating through the additional trimming heater. the heat supply of additional trimming heater can be regulated, - the additional trimming heater is heated with an external medium as for example, steam. The main advantage of such procedure lies therein that the gas /gas heat exchanger, which cools down the emerging flow out of the reactor' against the entering flow are meaningfully smaller sized. Surprisingly, it shows that in decreasing catalytic activity through recontrolling of reactor entry temperature, always an optimum utilization can be reached. Since as for example a steam heated trimming heater possesses many times better heat transfer properties than a gas / gas heat exchanger and because also the required safety reserve can be added alone to the trimming heater, it results "on balance" a saving in investment costs. Besides it shows, that the steam amount to be input in the trimming heater over the catalyst life is smaller than the loss in enclosure product for the case of loss on ground of reduced reaction turnover. Consequently on balance the generated amount of steam increases in spite of additional steam 4. requirement. Besides it, shows that the commissioning time gap of such a plant is reduced substantially when the trimming heater can be used as start heater. The above mentioned assignment is solved with an installation of the type as per generic term, that in at least in one synthesis stage a trimming heater is provided for heating of gas mixture charged directly to the methanol reactor. Further designs of installation, result from the further claims of installation, wherein the advantages assigned to these installations concur with the advantages of corresponding process. Further advantages, details and feature of invention result on ground of following description as well as with the help of the diagram. This shows in simplified representation one from many others, as rule identically standard stages of a methanol synthesis plant. For compression with input gas denoted with 1 a compressor 2 is provided, in doing so in further gas way a gas /gas exchanger 3 for pre-warming of input gas is provided. The so preheated gas is supplied over the line 4 to a trimming heater 5 which heats the input gas 1 to the desired temperature. For measurement of temperature, in the supply line 6 a temperature measurement-and regulating equipment 7 is provided, in doing so by means of a steam control valve 8 the steam supply 9 is controlled such that always an optimum gas entry temperature can be adjusted in catalyst filled methanol reactor 10. In catalyst filled methanol reactor 10 the input gas reacts under heat development. The reaction heat is utilized to 5. generate steam 12 out of supply water 11. The hot product gas T3 gives up a part of it's heat energy in gas/ gas heat exchanger 3. The gas forming methanol generated in the reactor is condensed out in methanol condenser 14 from the synthesis gas, separated in condensate separator V5 from the synthesis gas and is delivered as product methanol 16. The remaining synthesis gas 17 can be used further in the subsequent stage. In the plant as per invention the control of reaction in methanol reactor 10 mainly takes place over a pressure control for the cooling medium (water 11 or rather steam 12) not closer represented in the Figure, which surrounds the catalyst filled tube. In case the catalyst activity falls, it is then necessary to lift the entire temperature level in the reactor, which takes place through hiqh control of pressure of cooling medium, through which the vapourisation temperature of cooling medium rises. Through it the temperature in catalyst increases and the exit temperature 13 increases likewise. Over the heat exchanger 3 likewise the temperature in the line 4 increases, however not yet to the extent required for reaching optimum reaction conditions. This is then reached through the trimming heater 5. Identifiably the trimming heater 5 fulfills the essential assignment, to prevent the area requirement of gas / gas heat exchanger 3, at one side through it, that the temperature difference is increased on the otherside through it that the usual safety extra additions can be dispensed with and infact specially for this, because the heat transfer is better around a factor seven in trimming heater. The extra addition to the area from there much less, than in heat exchanger, passes out as an essential advantage of present invention. .. o ¦ o o o 6. Naturally the described execution example of the invention is to be. changed from many points of view, without abandoning the basic concept. Thus the trimming heater as for example if required can be built in two stages and the like more. WE CLAIM: 1. Method for synthesising methanol from hydrogen, carbon monoxide and carbon dioxide under pressure with at least one synthesis stage, which contains at least one catalyst filled methanol reactor, wherein in multiple stages at least one stage is equipped with a compressor and wherein all synthesis stages are equipped with internal product off-take for methanol and internal gas/gas-heat exchanger for transfer of heat energy of gas mixture leaving the methanol reactor to the gas mixture provided for imput in methanol reactor, characterised in that at least in one synthesis stage the gas mixture determined for the input In a catalyst filled methanol reactor is heated directly before the addition in said methanol reactor in en additional trimming heater. 2. Method as claimed in claim 1, wherein the temperature of gas mixture determined for the input in a catalyst filled methanol reactor is measured after it's heating though the trimming heater. 3. Method as claimed in claim 1 and 2, wherein, heat supply of trimming heater can be regulated. 4. Method as claimed in any of the preceeding claims, wherein the trimming heater is heated with an external medium, preferably steam. Method for synthesising methanol from hydrogen, carbon monoxide and carbon dioxide under pressure with at least one synthesis stage, which contains at least one catalyst filled methanol reactor, wherein in multiple stages at least one stage is equipped with a compressor and wherein all synthesis stages are equipped with internel product off-take for methanol and internal gas/gas-heat exchanger for transfer of heat energy of gas mixture leaving the methanol reactor to the gas mixture provided for imput in methanol reactor, characterised in that at least in one synthesis stage the gas mixture determined for the input in a catalyst Riled methanol reactor is heated directly before the addition in said methanol reactor in an additional trimming heater.

Full Text

1.

The invention refers to a process for methanol synthesis out of hydrogen. Carbon Monoxide and Carbon dioxide under pressure with at least one synthesis stage of, the type stated in generic term of Claim 1 as well as to a corresponding installation.
A series of installations or rather processes for catalytic methanol synthesis are known wherein for the fullness of solutions here as example the DE-2117060, DE-2529591, 0E-3220995 IDE-3518362, US-2904575 and the DE-4100632 are named.
From the WO 97/31707 a process is known in which a trimming heater is assembled before a corresponding gas/ gas-heat exchanger, through which the temperature difference of the latter is reduced and consequently it's area is increased. Such an area increase will be prevented through the present invention. In the WO 97/31707 also a technology is described in which the heat exchanger is integrated in the reactor, which compulsorily makes an additional heat exchanger necessary, because the reaction conditions otherwise are unstable.
In the DE-4028750 of the claimant a furnace (there 6) is input for reaching the necessary reaction temperature at entry of adialiatic reactor and as indirect heater for a boiler (there 11) in the, distillation. There only a small part of the reaction heat of reactor is used for heating up reaction entry gas..
The boiler serves there only to it, to drive on the following distillation.
In the DE-4004862 of claimant an additional heat exchanger

2.
is described, which is indeed input there as starting heat exchanger, whose use however does not have any reduction of usual heat exchanger area as a result.
As described in the DE-4100632, it is advantageous, to input more number of synthesis stages with reactors, to condense down their generated methanol, to separate from synthesis gas and to withdraw after each individual reactor as separate methanol-product flow. In the cooling down of methanol synthesis gas mixture leaving the reactor, it is economical, to utilize the given out heat at least partly, to heat up first the inlet flow in the respective reactors by means of gas/ gas-heat exchangers.
It was found disadvantageous in long years of operation, that the catalytic material input in the methanol reactor usually changes it 's activity in course of time such that always higher reactor temperatures are required to obtain an optimum utilisation and wherein indeed in the zones after the gas entry areas of reactors such high reactor temperatures, after some time are no more attainable. On ground of the reduced reaction turnover less methanol as well as less steam are produced which in the cooling of methanol reactors results as enclosure product.
It is the assignment of the invention to over come the mentioned disadvantageous and to procure such possibilities specially to save the heat exchanger areas and/or to increase the utilisation under special consideration of changeable catalytic activity.
With a process of the type described at entry the assignment is solved as per the invention through the distinguishing features of claim 1. Therein it is provided that at least in

3.
one synthesis stage the definite gas mixture determined for the input in a catalyst filled methanol reactor is heated directly before addition in the said methanol reactor in an additional trimming heater-Designs of invention exist among others therein that - the temperature of gas mixture determined for the input in the catalyst filed reactors is measured after it's heating through the additional trimming heater.
the heat supply of additional trimming heater can be regulated,
- the additional trimming heater is heated with an external medium as for example, steam.
The main advantage of such procedure lies therein that the gas /gas heat exchanger, which cools down the emerging flow out of the reactor' against the entering flow are meaningfully smaller sized. Surprisingly, it shows that in decreasing catalytic activity through recontrolling of reactor entry temperature, always an optimum utilization can be reached.
Since as for example a steam heated trimming heater possesses many times better heat transfer properties than a gas / gas heat exchanger and because also the required safety reserve can be added alone to the trimming heater, it results "on balance" a saving in investment costs. Besides it shows, that the steam amount to be input in the trimming heater over the catalyst life is smaller than the loss in enclosure product for the case of loss on ground of reduced reaction turnover. Consequently on balance the generated amount of steam increases in spite of additional steam

4.
requirement. Besides it, shows that the commissioning time gap of such a plant is reduced substantially when the trimming heater can be used as start heater.
The above mentioned assignment is solved with an installation of the type as per generic term, that in at least in one synthesis stage a trimming heater is provided for heating of gas mixture charged directly to the methanol reactor.
Further designs of installation, result from the further claims of installation, wherein the advantages assigned to these installations concur with the advantages of corresponding process.
Further advantages, details and feature of invention result on ground of following description as well as with the help of the diagram. This shows in simplified representation one from many others, as rule identically standard stages of a methanol synthesis plant.
For compression with input gas denoted with 1 a compressor 2 is provided, in doing so in further gas way a gas /gas exchanger 3 for pre-warming of input gas is provided. The so preheated gas is supplied over the line 4 to a trimming heater 5 which heats the input gas 1 to the desired temperature. For measurement of temperature, in the supply line 6 a temperature measurement-and regulating equipment
7 is provided, in doing so by means of a steam control valve
8 the steam supply 9 is controlled such that always an
optimum gas entry temperature can be adjusted in catalyst
filled methanol reactor 10.
In catalyst filled methanol reactor 10 the input gas reacts under heat development. The reaction heat is utilized to

5.
generate steam 12 out of supply water 11. The hot product gas T3 gives up a part of it's heat energy in gas/ gas heat exchanger 3. The gas forming methanol generated in the reactor is condensed out in methanol condenser 14 from the synthesis gas, separated in condensate separator V5 from the synthesis gas and is delivered as product methanol 16. The remaining synthesis gas 17 can be used further in the subsequent stage.
In the plant as per invention the control of reaction in methanol reactor 10 mainly takes place over a pressure control for the cooling medium (water 11 or rather steam 12) not closer represented in the Figure, which surrounds the catalyst filled tube. In case the catalyst activity falls, it is then necessary to lift the entire temperature level in the reactor, which takes place through hiqh control of pressure of cooling medium, through which the vapourisation temperature of cooling medium rises. Through it the temperature in catalyst increases and the exit temperature 13 increases likewise.
Over the heat exchanger 3 likewise the temperature in the line 4 increases, however not yet to the extent required for reaching optimum reaction conditions. This is then reached through the trimming heater 5. Identifiably the trimming heater 5 fulfills the essential assignment, to prevent the area requirement of gas / gas heat exchanger 3, at one side through it, that the temperature difference is increased on the otherside through it that the usual safety extra additions can be dispensed with and infact specially for this, because the heat transfer is better around a factor seven in trimming heater. The extra addition to the area from there much less, than in heat exchanger, passes out as an essential advantage of present invention.
.. o ¦ o o o

6.
Naturally the described execution example of the invention is to be. changed from many points of view, without abandoning the basic concept. Thus the trimming heater as for example if required can be built in two stages and the like more.

WE CLAIM:
1. Method for synthesising methanol from hydrogen, carbon monoxide and carbon
dioxide under pressure with at least one synthesis stage, which contains at least
one catalyst filled methanol reactor, wherein in multiple stages at least one stage
is equipped with a compressor and wherein all synthesis stages are equipped
with internal product off-take for methanol and internal gas/gas-heat exchanger
for transfer of heat energy of gas mixture leaving the methanol reactor to the gas
mixture provided for imput in methanol reactor, characterised in that at least in
one synthesis stage the gas mixture determined for the input In a catalyst filled
methanol reactor is heated directly before the addition in said methanol reactor in
en additional trimming heater.
2. Method as claimed in claim 1, wherein the temperature of gas mixture
determined for the input in a catalyst filled methanol reactor is measured after it's
heating though the trimming heater.
3. Method as claimed in claim 1 and 2, wherein, heat supply of trimming heater can
be regulated.
4. Method as claimed in any of the preceeding claims, wherein the trimming heater
is heated with an external medium, preferably steam.

Method for synthesising methanol from hydrogen, carbon monoxide and carbon dioxide under pressure with at least one synthesis stage, which contains at least one catalyst filled methanol reactor, wherein in multiple stages at least one stage is equipped with a compressor and wherein all synthesis stages are equipped with internel product off-take for methanol and internal gas/gas-heat exchanger for transfer of heat energy of gas mixture leaving the methanol reactor to the gas mixture provided for imput in methanol reactor, characterised in that at least in one synthesis stage the gas mixture determined for the input in a catalyst Riled methanol reactor is heated directly before the addition in said methanol reactor in an additional trimming heater.

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Patent Number

207206

Indian Patent Application Number

IN/PCT/2002/00230/KOL

PG Journal Number

22/2007

Publication Date

01-Jun-2007

Grant Date

31-May-2007

Date of Filing

14-Feb-2002

Name of Patentee

UHDE GMBH., GERMANY,FRIEDRICH-UHDE-STRASSE

Applicant Address

UHDE-STRASSE 15,44141 DORTMUND

Inventors:

#	Inventor's Name	Inventor's Address
1	BAHNISCH HANS-JOACHIM	BOMELBURGSTRASSE 10,44227 DORTMUND

PCT International Classification Number

C07C 29/151

PCT International Application Number

PCT/EP00/08486

PCT International Filing date

2000-08-31

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	19942736.4	1999-09-07	Germany
2	19948585	1999-10-08	Germany