PROCESS FOR SYNTHESISING METHANOL

Abstract

A process for synthesising methanol comprising the steps of: passing a hydrocarbon feedstock to a synthesis gas generation unit to form a synthesis gas containing hydrogen, carbon monoxide, carbon dioxide and steam; cooling the synthesis gas in one or more stages of heat exchange and recovering a process condensate from the cooled synthesis gas to form a make-up gas having a stoichiometry value R in the range of 1.70 to 1.94; passing a feed gas comprising the make-up gas to a methanol synthesis unit comprising one or more methanol synthesis reactors containing a copper methanol synthesis catalyst, and; recovering a purge gas and a crude methanol product from the methanol synthesis unit, wherein a hydrogen-rich gas is recovered from the purge gas and combined with the make-up gas, and a stream of water or steam is added to the feed gas to the methanol synthesis unit.

Claims

1. A process for synthesising methanol comprising the steps of: (i) passing a hydrocarbon feedstock to a synthesis gas generation unit to form a synthesis gas containing hydrogen, carbon monoxide, carbon dioxide and steam; (ii) cooling the synthesis gas in one or more stages of heat exchange and recovering a process condensate from the cooled synthesis gas to form a make-up gas having a stoichiometry value R in the range of 1.70 to 1.94; (iii) passing a feed gas comprising the make-up gas to a methanol synthesis unit comprising one or more methanol synthesis reactors containing a copper methanol synthesis catalyst, and; (iv) recovering a purge gas and a crude methanol product from the methanol synthesis unit, wherein a hydrogen-rich gas is recovered from the purge gas and combined with the make-up gas, and a stream of water or steam is added to the feed gas to the methanol synthesis unit.

2. The process according to claim 1, wherein the synthesis gas generation unit comprises a partial oxidation unit having one or more catalytic, or non-catalytic, partial oxidation vessels, or a gasification unit containing one or more gasifiers, or a reforming unit comprising one of more catalytic steam reformers.

3. The process according to claim 1, wherein the synthesis gas generation unit comprises an autothermal reformer.

4. The process according to claim 1, wherein the synthesis gas generation unit comprises an adiabatic pre-reformer and autothermal reformer connected in series.

5. The process according to claim 1, wherein the hydrocarbon feedstock comprises natural gas.

6. The process according to claim 4, wherein the hydrocarbon feedstock is pre-reformed in an adiabatic pre-reformer upstream of the autothermal reformer with steam at a steam to carbon ratio in the range of 0.3 to 3.

7. The process according to claim 1, wherein the synthesis gas contains 2.5 to 7% by volume of carbon dioxide on a wet basis.

8. The process according to claim 1, wherein the feed gas has a stoichiometry number R which is higher than that of the make-up gas

9. The process according to claim 1, wherein the amount of water or steam added to the feed gas to the methanol synthesis unit is in the range 0.1 to 6 mole % on make-up gas.

10. The process according to claim 1, wherein at least portion of the water added to the feed gas is recovered from a purge gas washing step.

11. The process according to claim 1, wherein the methanol synthesis unit comprises one, two or more methanol synthesis reactors each containing a bed of methanol synthesis catalyst.

12. The process according to claim 1, wherein an unreacted gas mixture separated from a product gas mixture recovered from one methanol synthesis reactor is returned to the same or a different methanol synthesis reactor.

13. The process according to claim 1, wherein the methanol synthesis unit comprises a first methanol synthesis reactor and a second methanol synthesis reactor connected in series, wherein the first methanol synthesis reactor operates on a once-through basis and gas fed to the second methanol synthesis reactor consists of all of an unreacted gas stream recovered from the first methanol synthesis reactor and a recycle gas stream recovered from the second methanol synthesis reactor.

14. The process according to claim 1, wherein the methanol synthesis unit comprises a first methanol synthesis reactor and a second methanol synthesis reactor connected in series, wherein a portion of an unreacted gas stream recovered from the first methanol synthesis reactor is recycled to the first methanol synthesis reactor and a portion of an unreacted gas stream recovered from the second methanol synthesis reactor is recycled to the second methanol synthesis reactor.

15. The process according to claim 1, wherein the methanol synthesis unit comprises a first methanol synthesis reactor and a second methanol synthesis reactor connected in series, wherein a portion of an unreacted gas stream recovered from the second methanol synthesis reactor is recycled to the first methanol synthesis reactor.

16. The process according to claim 13, wherein the first methanol synthesis reactor is an axial-flow steam-raising converter and the second methanol synthesis reactor is an axial-flow steam-raising converter, a radial-flow steam-raising converter, a gas-cooled converter or a tube-cooled converter.

17. The process according to claim 1, wherein the copper methanol synthesis catalyst comprises copper, zinc oxide and alumina.

18. The process according to claim 1, wherein a carbon-rich off gas obtained by separation of the hydrogen-rich gas from the purge gas is used as a fuel in a fired heater to heat one or more feed streams to the synthesis gas generation unit, or is exported to a separate process.

19. The process according to claim 12, wherein a CO.sub.2 removal unit is included to recover carbon dioxide from the unreacted gas and exported for use in a separate process or purified and sequestered or used for enhanced oil recovery.

20. The process according to claim 1, wherein a carbon dioxide stream is recovered from the crude methanol and used in an external chemical synthesis process or for enhanced oil recovery or sequestered in a carbon capture and storage unit.

21. The process according to claim 1, wherein the crude methanol is subjected to one or more steps of distillation to produce a purified methanol product.

22. A process according to claim 1, wherein the synthesis gas contains 3 to 5% by volume of carbon dioxide on a wet basis.

23. A process according to claim 14, wherein the first methanol synthesis reactor is an axial-flow steam-raising converter and the second methanol synthesis reactor is an axial-flow steam-raising converter, a radial-flow steam-raising converter, a gas-cooled converter or a tube-cooled converter.

24. A process according to claim 15, wherein the first methanol synthesis reactor is an axial-flow steam-raising converter and the second methanol synthesis reactor is an axial-flow steam-raising converter, a radial-flow steam-raising converter, a gas-cooled converter or a tube-cooled converter.

Description

[0067] The invention will be further described by reference to the figures in which:

[0068] FIG. 1 depicts a process according to one embodiment of the invention,

[0069] FIG. 2 depicts a further process according to another embodiment of the invention,

[0070] FIG. 3 depicts a further process according to another embodiment of the invention, and

[0071] FIG. 4 depicts a further process according to another embodiment of the invention.

[0072] In FIGS. 1 to 4, the synthesis gas generation unit comprises a pre-reformer and an autothermal reformer. In FIGS. 1, the methanol synthesis unit comprises a single stage, i.e. one methanol synthesis converter, or parallel converters of the same design, operated in a loop. In FIGS. 2 and 3, the methanol synthesis unit comprises two stages connected in series, with the first stage operated on a once-through basis and the second stage operated in a loop. In FIG. 4, the methanol synthesis unit comprises two methanol stages connected in series, with the both stages operated in loops.

[0073] It will be understood by those skilled in the art that the drawings are diagrammatic and that further items of equipment such as feedstock drums, pumps, vacuum pumps, compressors, gas recycling compressors, temperature sensors, pressure sensors, pressure relief valves, control valves, flow controllers, level controllers, holding tanks, storage tanks and the like may be required in a commercial plant. Provision of such ancillary equipment forms no part of the present invention and is in accordance with conventional chemical engineering practice.

[0074] In FIG. 1, a mixture of natural gas and steam supplied by line 10 is fed to a fired heater 12 where it is heated. The heated gas mixture is fed from the fired heater 12 by line 14 to a pre-reformer 16 containing a fixed bed of particulate steam reforming catalyst. The heated gas mixture is reformed adiabatically over the catalyst thereby converting higher hydrocarbons present in the natural gas to methane, carbon oxides and hydrogen. The pre-reformed gas mixture is fed from the pre-reformer 16 by line 18 to the fired heater 12 where it is heated to the autothermal reformer inlet temperature. The re-heated pre-reformed gas mixture is fed from the fired heater 12 via line 20 to an autothermal reformer 22 fed with an oxygen stream 24. In the autothermal reformer, the pre-reformed gas mixture is partially combusted with the oxygen in a burner mounted near the top and the resulting hot, partially-combusted gas brought to equilibrium through a bed of steam reforming catalyst disposed beneath the burner. The resulting autothermally reformed synthesis gas stream is fed from the autothermal reformer 22 via line 26 to a heat recovery unit 28 comprising one or more heat exchangers, where it is cooled to below the dew point to condense steam. Process condensate 30 is removed from the cooled gas mixture using gas-liquid separation equipment in the heat recovery unit to produce a make-up gas. A portion of the condensate 30 may be used to generate the steam used to prepare the feed gas 14 provided to the pre-reformer 16. The make-up gas is recovered from the heat recovery unit 28 via line 32, combined with a hydrogen-rich stream provided via line 34, and the resulting mixture fed via line 36 to a syngas compressor 38 where it is compressed. A compressed gas mixture is recovered from the syngas compressor 38 via line 40 and combined with a recycle loop gas provided by line 42 to form a feed gas mixture, which is fed via line 44 to a circulating compressor 46, where the mixture is compressed to the loop pressure. A compressed feed gas is recovered from the circulating compressor 46 via line 48 and mixed with a stream of steam fed via steam injection line 50. The resulting mixture of feed gas and steam is fed via line 52 to a gas-gas interchanger 54, where it is heated to the methanol converter inlet temperature and then fed via line 56 to the inlet of a methanol synthesis reactor 58. Whereas a single converter is depicted, it will be understood that this flowsheet may operate with two or more converters operated in parallel. The methanol synthesis reactor 58 is an axial-flow steam-raising converter comprising methanol synthesis catalyst-filled tubes 60 cooled by boiling water under pressure 62. Methanol synthesis and water-gas shift reactions take place in the reactor 58 to generate a product gas mixture comprising methanol, unreacted hydrogen, and carbon dioxide. The product gas mixture is recovered from the reactor 58 via line 64, cooled in the interchanger 54 and fed via line 66 to one or more further heat exchangers 68 where it is cooled to below the dew point to condense a liquid crude methanol. The cooled mixture is passed from the one or more heat exchangers 68 via line 70 to a gas liquid separator 72, where the unreacted gases are separated from the liquid crude methanol, which is recovered from the separator 72 via line 74. The crude methanol is sent to a distillation and purification unit (not shown) where it is degassed and distilled in two or three stages of distillation to produce a purified methanol product. The unreacted gases are recovered from the separator 72 and divided. A portion is passed via line 42 as the recycle loop gas to form part of the feed gas to the methanol synthesis reactor 58. The remaining portion is fed via line 78 as a purge gas, to a purge gas washing unit 80, which is fed with a water stream 82, and which generates a purge gas wash stream 84 containing a small amount of methanol. The purge gas wash stream is heated to generate steam, a portion of which may be fed to the feed gas mixture via line 50. A washed purge gas is recovered from the purge gas washing unit 80 and fed via line 86 to a membrane hydrogen recovery unit 88, where a hydrogen-rich stream is separated from the washed purge gas and supplied via line 34 to the make-up gas stream in line 32. A carbon rich off gas is recovered from the hydrogen recovery unit 88 via line 90 and sent as fuel to be combusted in the fired heater 12.

[0075] In FIG. 2, the synthesis gas generation unit is the same as depicted in FIG. 1. However, whereas in FIG. 1, the methanol synthesis unit operates a single reactor in a loop, the methanol synthesis unit in FIG. 2 operates with two methanol synthesis reactors connected in series, with a first reactor operating on a once-through basis, and the unreacted gases from the separator downstream of the first reactor fed instead to a further methanol synthesis reactor operating in a loop. Thus, in FIG. 2, the compressed mixture of make-up gas and hydrogen-rich gas in line 40 is mixed with steam in line 50, heated in gas-gas interchanger 54, passed through reactor 58, cooled in the interchanger 54 and further heat exchangers 68 and passed to the gas-liquid separator 72, from which a first stream of crude liquid methanol 74 is recovered. A first unreacted gas mixture 76 recovered from the gas-liquid separator 72 is combined with a second unreacted gas mixture from line 110 and the combined feed gas passed via line 112 to circulating compressor 114. The compressed feed gas is fed from the compressor 114 via line 116 to a second gas-gas interchanger 118 where it is heated and then fed via line 120 to the inlet of a radial-flow steam-raising converter 122 containing an annular bed of catalyst 124 cooled by tubes or plates containing boiling water under pressure 126. Whereas a radial flow steam-raising converter is depicted, the process may equally be performed using an axial-flow steam-raising converter, a gas-cooled converter, or a tube-cooled converter. A second product gas mixture is recovered from the reactor 122 via line 128 and cooled in the interchanger 118 and one or more further heat exchangers 130 to below the dew point. The cooled mixture is then passed from the heat exchangers 130 to a second gas-liquid separator 132, from which a second stream of liquid crude methanol is recovered via line 134. The first and second crude liquid methanol streams may, if desired, be combined before being sent for purification to produce a purified methanol product as described above. An unreacted gas mixture 136 is recovered from the second gas-liquid separator 132 and divided into the second unreacted gas stream 110 and a purge stream 138. The purge 138 is fed to a purge gas washing unit 140, which is fed with a water stream 142, and which generates a purge gas wash stream 144 containing a small amount of methanol. The purge gas wash stream is heated to generate steam, a portion of which may be fed to the feed gas mixture via line 50. A washed purge gas is recovered from the purge gas washing unit 140 and fed via line 146 to a membrane hydrogen recovery unit 148, where a hydrogen-rich stream is separated from the washed purge gas and supplied via line 34 to the make-up gas stream in line 32. A carbon rich off gas is recovered from the hydrogen recovery unit 148 via line 150 and sent as fuel to be combusted in the fired heater 12.

[0076] In FIG. 3, the synthesis gas generation unit and methanol synthesis unit are the same as depicted in FIG. 2, except that a portion of the gas fed to the radial-flow steam-raising converter is recycled to supplement the feed gas to the axial-flow steam-raising converter. Thus, the feed gas 116 to the radial-flow steam-raising converter 122, is divided into first and second portions. The first portion is heated in interchanger 118 and fed to the radial-flow steam-raising converter 122. The second portion is fed via line 152 to the compressed feed gas in line 40 upstream of the steam or water addition via line 50, heated in interchanger 54 and fed to the axial-flow steam-raising converter 58.

[0077] Optionally, as shown in dashed lines, at least a portion of the unreacted gas mixture 76 recovered from the first gas-liquid separator 72 may be passed to a CO.sub.2 removal unit 160 to remove a portion of the carbon dioxide from the first unreacted gas mixture. The CO.sub.2 removal unit 160 may suitably be a membrane unit that produces a CO.sub.2-depleted gas mixture 164 that is combined with the second unreacted gas mixture 110 to form the feed gas for the radial-flow steam-raising converter. The CO.sub.2 removal unit also produces a CO.sub.2 stream 162, which may be fed to an external process or sequestered in a CO.sub.2-capture facility.

[0078] FIG. 4, the synthesis gas generation unit and methanol synthesis unit are the same as depicted in FIG. 2, except that the purge gas mixture 138 taken from the unreacted gas mixture 136 is divided. A first portion is passed to the purge gas washing unit 140 and hydrogen separation unit 148 for generation of the hydrogen-rich stream 34. A second portion bypasses these and is recycled to the compressed feed gas in line 40 upstream of the steam addition via line 50 to the feed gas for the axial-flow steam-raising converter 58. In this arrangement, the second unreacted gas stream 110 is not combined with the unreacted gas stream in line 76 (or optionally the CO.sub.2-depleted gas stream 164) but is instead fed directly to the circulating compressor 114. Optionally, as shown in FIG. 3, at least a portion of the unreacted gas mixture 76 recovered from the first gas-liquid separator 72 may be passed to a CO.sub.2 removal unit 160 to remove a portion of the carbon dioxide from the first unreacted gas mixture, thereby generating a CO.sub.2 stream 162 and a CO.sub.2-depleted gas 164, which may be fed to the circulating compressor 114.

[0079] The invention will be further described by reference to the following calculated examples prepared using conventional modelling software suitable for methanol processes. These examples are all based on same quantity of H.sub.2+CO in Nm.sup.3/h at the exit of the ATR, which was operated at a steam to carbon ratio of 0.6:1 and a pressure of 34 bara.

Example 1

[0080] Example 1 is an example of a flowsheet in accordance with FIG. 1. The process conditions and compositions of the various streams are set out below.

TABLE-US-00001 Stream number 20 24 26 30 32 34 36 Temperature (? C.) 650 228 1050 92 45 55 46 Pressure (bar a) 35.4 39.5 34.0 30.9 30.9 30.9 30.9 Mass flow (tonne/h) 201.1 126.0 327.1 76.2 250.8 21.7 272.5 Molar flow (kgmole/h) 11972 3960 25666 4230 21436 2789 24225 Molecular weight 16.79 31.83 12.74 18.02 11.70 7.77 11.25 Composition (kgmole/h) Water 3986.6 55.5 4305.8 4228.2 77.4 9.5 86.9 Hydrogen 486.0 13849.3 13849.3 2339.5 16188.8 Carbon monoxide 3.9 6110.3 0.7 6109.6 50.4 6160.1 Carbon dioxide 267.5 974.7 0.9 973.8 318.7 1292.5 Nitrogen 35.9 35.9 35.9 7.3 43.3 Argon 11.7 11.7 11.7 5.5 17.2 Methane 7192.2 378.3 378.2 58.0 436.2 Methanol Oxygen 3892.7 Lights Heavies

TABLE-US-00002 Stream number 42 44 50 56 64 70 74 Temperature (? C.) 45 88 303 230 251 45 45 Pressure (bar a) 76.8 76.3 84.2 83.0 80.0 77.1 77.0 Mass flow (tonne/h) 462.1 734.7 9.9 744.6 744.6 744.6 239.8 Molar flow (kgmole/h) 42872 67097 550 67647 54761 54761 7936 Molecular weight 10.78 10.95 18.02 11.01 13.60 13.60 30.22 Composition (kgmole/h) Water 21.7 108.6 550.0 658.6 1195.5 1195.5 1171.9 Hydrogen 29846.5 46035.3 46035.3 32622.9 32622.9 24.1 Carbon monoxide 2542.3 8702.3 8702.4 2788.6 2788.6 12.0 Carbon dioxide 5303.4 6595.8 6595.8 6063.8 6063.8 271.5 Nitrogen 453.4 496.7 496.7 496.6 496.6 1.5 Argon 177.6 194.8 194.8 194.8 194.8 0.9 Methane 4249.3 4685.5 4685.5 4685.5 4685.5 44.4 Methanol 272.8 272.8 272.8 6698.9 6698.9 6401.2 Oxygen Lights 5.1 5.0 5.1 12.1 12.1 6.5 Heavies 2.1 2.1 2.1

TABLE-US-00003 Stream number 76 78 82 84 86 90 Temperature (? C.) 45 45 46 51 53 54 Pressure (bar a) 77.0 76.2 76.5 76.2 75.8 72.6 Mass flow (tonne/h) 504.7 42.6 7.0 7.7 41.9 20.2 Molar flow (kgmole/h) 46825 3953 390 408 3935 1146 Molecular weight 10.78 10.78 18.02 18.96 10.65 17.64 Composition (kgmole/h) Water 23.7 2.0 390.0 381.5 10.4 0.9 Hydrogen 32598.6 2752.0 2752.1 412.7 Carbon monoxide 2776.7 234.4 0.0 234.4 183.9 Carbon dioxide 5792.3 489.0 1.3 487.7 169.0 Nitrogen 495.2 41.8 41.8 34.5 Argon 193.9 16.4 16.4 10.9 Methane 4641.1 391.8 0.1 391.7 333.6 Methanol 298.0 25.2 25.0 0.1 Oxygen Lights 5.5 0.5 0.5 0.5 Heavies

Example 2Comparative

[0081] Example 2 is the same as Example 1, and is based on the process depicted in FIG. 1 but omits the steam injection line 50 and adds a make-up gas feed line, which passes a portion of the make-up gas, identified below as line 41, from the compressed make-up gas mixture line to the washed purge gas 86, which is fed to the hydrogen recovery unit 88. This is an example of a process claimed in WO2016180812 A1. The process conditions and compositions of the various streams are set out below.

TABLE-US-00004 Stream number 20 24 26 30 32 34 36 Temperature (? C.) 650 228 1050 93 45 101 51 Pressure (bar a) 35.4 39.5 34.0 30.9 30.9 30.9 30.9 Mass flow (tonne/h) 201.1 126.0 327.1 76.2 250.8 17.6 268.5 Molar flow (kgmole/h) 11972 3959 25665 4230 21435 2502 23938 Molecular weight 16.79 31.83 12.74 18.02 11.70 7.04 11.21 Composition (kgmole/h) Water 3986.6 55.5 4305.6 4228.1 77.4 10.5 87.9 Hydrogen 486.0 13848.6 13848.4 2103.7 15952.5 Carbon monoxide 3.9 6109.7 0.7 6109.0 123.4 6232.5 Carbon dioxide 267.5 974.8 0.9 973.9 187.3 1161.2 Nitrogen 35.9 35.9 35.9 8.3 44.3 Argon 11.7 11.7 11.7 5.9 17.6 Methane 7192.1 378.8 378.7 63.3 442.0 Methanol Oxygen 3891.9 Lights Heavies

TABLE-US-00005 Stream number 41 42 44 56 64 70 74 Temperature (? C.) 175 45 88 230 251 45 45 Pressure (bar a) 77.0 76.8 76.3 83.0 80.0 77.1 77.0 Mass flow (tonne/h) 16.1 450.7 703.1 703.1 703.1 703.1 228.3 Molar flow (kgmole/h) 1436 42871 65372 65372 52595 52595 7439 Molecular weight 11.21 10.51 10.76 10.76 13.37 13.37 30.69 Composition (kgmole/h) Water 5.3 15.9 98.5 98.5 786.2 786.2 769.5 Hydrogen 957.2 28467.1 43462.0 43462.0 30008.6 30008.6 24.2 Carbon monoxide 374.0 2582.2 8440.6 8440.6 2731.9 2731.9 12.1 Carbon dioxide 69.7 3966.1 5057.6 5057.6 4374.9 4374.9 197.4 Nitrogen 2.7 735.4 776.9 776.9 776.9 776.9 2.4 Argon 1.1 282.0 298.6 298.6 298.6 298.6 1.5 Methane 26.5 6523.6 6939.0 6939.0 6939.0 6939.0 67.7 Methanol 293.4 293.4 293.4 6663.6 6663.6 6354.6 Oxygen Lights 5.4 5.4 5.4 13.0 13.0 7.4 Heavies 2.2 2.2 2.2

TABLE-US-00006 Stream number 76 78 82 84 86 90 Temperature (? C.) 45 45 46 52 99 101 Pressure (bar a) 77.0 76.2 76.5 76.2 75.8 72.6 Mass flow (tonne/h) 474.8 24.0 4.0 4.4 39.7 22.1 Molar flow (kgmole/h) 45156 2286 220 231 3711 1209 Molecular weight 10.51 10.51 18.02 19.02 10.70 18.28 Composition (kgmole/h) Water 16.7 0.8 220.1 214.7 11.5 1.1 Hydrogen 29984.4 1517.8 2474.9 371.2 Carbon monoxide 2719.8 137.7 0.0 511.6 388.2 Carbon dioxide 4177.5 211.5 0.6 280.6 93.2 Nitrogen 774.6 39.2 41.9 33.5 Argon 297.1 15.0 16.1 10.2 Methane 6871.3 347.8 0.1 374.2 310.9 Methanol 309.0 15.6 15.5 0.1 Oxygen Lights 5.6 0.3 0.3 0.3 Heavies

Example 3

[0082] Example 3 is for a process according to FIG. 2, utilising two stages of methanol synthesis in which the first stage comprises an axial-flow steam-raising converter operated on a once through basis followed by a radial-flow steam-raising converter operated in a loop. The process conditions and compositions of the various streams are set out below.

TABLE-US-00007 Stream number 20 24 26 30 32 34 36 Temperature (? C.) 650 228 1050 93 45 53 46 Pressure (bar a) 35.4 39.5 34.0 30.9 30.9 30.9 30.9 Mass flow (tonne/h) 201.1 126.0 327.1 76.3 250.8 21.8 272.7 Molar flow (kgmole/h) 11971 3960 25665 4231 21435 2806 24241 Molecular weight 16.79 31.83 12.74 18.02 11.70 7.78 11.25 Composition (kgmole/h) Water 3986.4 55.5 4306.4 4229.0 77.4 9.0 86.5 Hydrogen 485.8 13848.0 13848.4 2347.0 16195.6 Carbon monoxide 3.8 6109.7 0.7 6109.2 58.0 6167.2 Carbon dioxide 267.4 974.9 0.9 974.0 314.2 1288.3 Nitrogen 35.9 35.9 35.9 7.8 43.7 Argon 11.7 11.7 11.7 5.9 17.6 Methane 7191.6 378.4 378.3 63.7 442.0 Methanol Oxygen 3892.7 Lights Heavies

TABLE-US-00008 Stream number 50 56 64 70 74 76 110 Temperature (? C.) 301 230 247 45 45 45 45 Pressure (bar a) 82.5 82.1 80 78.2 78.1 78.1 78.1 Mass flow (tonne/h) 10.8 283.5 283.5 283.5 107.3 176.2 440.0 Molar flow (kgmole/h) 600 24841 18447 18447 3374 15073 40697 Molecular weight 18.02 11.41 15.37 15.37 31.80 11.69 10.81 Composition (kgmole/h) Water 600.0 686.5 133.6 133.6 131.5 2.1 31.4 Hydrogen 16195.6 10361.9 10361.9 13.6 10348.3 28102.1 Carbon monoxide 6167.3 2412.1 2412.1 16.0 2396.0 2645.1 Carbon dioxide 1288.3 1844.3 1844.3 121.8 1722.5 4874.5 Nitrogen 43.7 43.7 43.7 0.2 43.5 435.5 Argon 17.6 17.6 17.6 17.5 174.4 Methane 442.0 442.0 442.0 6.5 435.5 4196.8 Methanol 3185.2 3185.2 3078.8 106.4 231.2 Oxygen Lights 5.2 5.2 4.0 1.2 5.9 Heavies 1.4 1.4 1.3

TABLE-US-00009 Stream number 120 128 134 136 138 142 144 Temperature (? C.) 235 278 45 45 45 46 51 Pressure (bar a) 80.5 80.0 78.2 78.2 78.1 77.7 77.4 Mass flow (tonne/h) 616.2 616.2 133.0 483.3 43.2 7.1 7.8 Molar flow (kgmole/h) 55770 49299 4603 44696 3999 396 413 Molecular weight 11.05 12.50 28.88 10.81 10.81 18.02 18.86 Composition (kgmole/h) Water 33.5 1144.0 1109.6 34.5 3.1 396.0 389.2 Hydrogen 38450.3 30873.8 10.6 30863.5 2761.3 Carbon monoxide 5041.2 2911.6 6.6 2905.1 259.9 0.0 Carbon dioxide 6597.0 5490.9 137.4 5353.5 479.0 1.3 Nitrogen 479.0 478.9 0.7 478.2 42.8 Argon 191.9 191.9 0.3 191.6 17.1 Methane 4632.3 4632.2 23.1 4609.1 412.4 0.1 Methanol 337.6 3564.7 3310.7 253.9 22.7 22.6 Oxygen Lights 7.1 8.4 1.9 6.5 0.6 Heavies 2.3 2.3

TABLE-US-00010 Stream number 146 150 Temperature (? C.) 52 53 Pressure (bar a) 76.3 73.8 Mass flow (tonne/h) 42.6 20.8 Molar flow (kgmole/h) 3982 1176 Molecular weight 10.69 17.65 Composition (kgmole/h) Water 9.9 0.9 Hydrogen 2761.3 414.2 Carbon monoxide 259.9 201.8 Carbon dioxide 477.7 163.5 Nitrogen 42.8 35.0 Argon 17.1 11.2 Methane 412.2 348.5 Methanol 0.1 Oxygen Lights 0.6 0.6 Heavies

[0083] A comparison of the Examples is given below.

TABLE-US-00011 Methanol make Example (kmol/h) 1 6426 2 Comparative 6370 3 6412

[0084] In the Examples, the total methanol make consists of the methanol content of the crude methanol stream plus the methanol recovered from the purge gas washing unit in the purge gas wash stream. Both examples 1 and 3 are superior to the comparative arrangement in Example 2.