LU103404B1 - Process and plant for the production of methanol from a carbon-containing feedstock - Google Patents

Abstract

Process and Plant for the Production of Methanol from a Carbon-Containing Feedstock The invention relates to a process for the production of methanol from a carbon-containing feedstock. In a process in which efficiency and energy use are optimized, at least the following steps are included: preparation of at least one carbon-containing feedstock (2); gasification in a gasifier (3) or pyrolysis in a pyrolysis furnace of the prepared carbon-containing feedstock to obtain a crude synthesis gas; processing of the crude synthesis gas (4) to obtain a synthesis gas; methanol synthesis (5) to obtain crude methanol; expansion of the crude methanol in a low-pressure separator (7); distillation of the expanded crude methanol to obtain methanol and an overhead product; withdrawal of a partial stream from the methanol synthesis (5) and feeding at least a portion of the partial stream to the preparation of the carbon-containing feedstock.

Description

230557 P00LU 09.10.2024

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Description

Process and plant for the production of methanol from a carbonaceous

active ingredient

The invention relates to a process for producing methanol from a carbon-containing feedstock.

In addition, the invention relates to a plant for the production of methanol from a carbon-containing feedstock.

Methanol is produced through an exothermic reaction, which uses as starting materials

The system provides for hydrogen and carbon oxides, which are fed as a gas stream into a suitable reactor for methanol synthesis. These substances can be obtained from various sources.

One possibility is to use a carbon-based energy carrier electricity from a

to subject it to steam reforming or, for example, catalytic partial oxidation, so that a synthesis gas consisting essentially of hydrogen and carbon oxides is obtained. Depending on the type of energy carrier and the method of production of the

Different proportions of hydrogen and the synthesis gas are added.

Carbon oxides – and thus a different stoichiometry – are achieved in the synthesis gas. The resulting stechiometry can then be adjusted by various measures, such as subjecting it to a water-gas shift reaction.

The advantage of this approach is that the energy carrier itself – e.g.

Natural gas can be regularly supplied at high pressure, so that after the synthesis gas has been obtained, only a comparatively small pressure increase is necessary to reach the pressure required for methanol synthesis.

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Another way to provide the starting materials for the synthesis of methanol is to use a gas stream with a high carbon dioxide content and without

to use hydrogen. Such a gas stream can be obtained, for example, from flue gas, i.e., from the exhaust gas of a combustion process. Similarly, such a gas stream could be obtained from a bioethanol production plant. Since such flue gas does not contain hydrogen, this variant requires the...

Hydrogen may be supplied from another source, for example from a

Electrolysis. For methanol synthesis, the gas is regularly circulated with the reactants in a cycle, since a single pass of this gas through the reactor usually does not lead to a sufficiently extensive conversion into methanol.

The converted methanol is regularly removed by condensation from the circulating

Gas is removed. At the same time, however, inert substances also accumulate due to the circulation, which cannot be sufficiently removed by this condensation.

To remove these substances from the cycle, it is necessary to discharge a portion of the circulating gas as purge gas, which can then be burned, for example.

Future-oriented processes or systems utilize an organic

Substance, such as biomass, that is gasified to synthesize methanol. There are various methods for this. Compared to plants for the synthesis of

These plants require methanol produced from fossil fuels.

The process involves more complex pretreatments and also gas purification.

In a typical methanol plant, gasification is carried out using steam and oxygen. The reason for using steam is that the

Biomass is thermally decomposed, and the water vapor reacts with the carbon from the organic matter to form hydrogen. Methanol synthesis takes place under high pressure, and if air is used for the synthesis, the nitrogen it contains increases the power required and also reduces the efficiency of the methanol synthesis. Therefore, the use of oxygen is preferred.

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Conventional plants that have previously operated without biomass or comparable carbon-containing feedstocks are considered costly.

Plant systems for the synthesis of methanol, especially from biomass, are only competitive to a limited extent.

The invention is therefore based on the objective of providing a method and a system for

Production of methanol from a carbon-containing feedstock, in particular

to provide biomass or a comparable carbon-containing feedstock, where efficiency and energy use are optimized.

This objective is initially achieved in the present invention by the features of the

Claim 1 is solved by the fact that the method comprises at least the following

The process includes: processing of at least one carbon-containing feedstock;

Gasification in a gasifier and/or pyrolysis in a pyrolysis furnace of the processed carbon-containing feedstock, to obtain a raw synthesis gas;

Processing of the raw synthesis gas to obtain a synthesis gas;

Methanol synthesis to obtain crude ethanol; distillation of the crude ethanol to

Obtaining methanol and a head product; extracting a partial stream of the

Methanol synthesis and feeding at least a part of the partial stream to

Processing of the carbon-containing feedstock.

Carbon-containing feedstocks include, in particular, carbon-containing materials.

The term refers to solids and/or carbon-containing liquids. Preferably, the carbon-containing feedstock is biomass. Particularly preferably, the carbon-containing feedstock is waste, for example...

Household waste, plastic, etc.

Accordingly, the processing of the carbon-containing feedstock can be designed in different ways, whereby it is clear to those skilled in the art that the processing can and must differ for different feedstocks.

Processing can include steps such as drying and/or grinding the carbon-containing feedstock. Torrefaction is another possibility.

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LU103404, for example, to process biomass or solids. Another

One possibility would be a type of carbonization.

Depending on how the gasification and/or pyrolysis of the processed carbonaceous feedstock takes place, the processing must be adapted accordingly. With a fluidized bed gasifier, it is generally necessary to break down the structure of the carbonaceous material to achieve an acceptable result. With fixed-bed or fluidized bed gasifiers, the processing is usually less complex.

Methanol synthesis takes place in a suitable reactor system. Adiabatic reactors and quasi-isothermal reactors are the most common. In adiabatic reactors

In reactors with a single catalyst bed, the reaction is quenched by adding cold gas at multiple points. The temperature profile along the

The reactor axis is therefore sawtooth-shaped. In reactors where the synthesis gas flows through several axially arranged reactor layers, the

The heat of reaction is removed by an intercooler. In these reactors, the...

Synthesis gas axially, radially or axially/radially through the catalyst beds.

The standard quasi-isothermal reactor consists of a tube reactor cooled by water. The catalyst is located in pipes that serve to remove the

are surrounded by the heat of reaction of water at its boiling point. The temperature of the

The cooling medium is adjusted by a preset pressure in the steam drum.

The synthesis gas flows through the pipes in an axial direction.

It is also possible to have several reactors connected in series, which together form a facility for methanol synthesis.

In the first column of the distillation section of a methanol plant, primarily volatile, dissolved components are extracted from the crude methanol, such as...

Carbon oxides, methane, and hydrogen are drawn off overhead. This overhead product can then be used as fuel gas. However, it contains a large amount of CO, which limits its calorific value, as well as many volatile components, whose

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Combustion leads to greater CO emissions. Furthermore, it contains

The head product contains a large amount of methanol.

The crude methanol leaving the reactor contains water and other impurities.

The quantity and composition of these impurities depend on the

Reaction conditions, the gas used, and the type and lifespan of the

catalyst. The crude methanol contains low-boiling and high-boiling elements.

Components (light and heavy). Light components mainly include dissolved gases (e.g., CO₂), dimethyl ether, methyl formate, and acetone. Heavy components include...

Ends include higher alcohols, long-chain hydrocarbons, higher ketones and

Esters of lower alcohols.

The impurities in crude methanol are generally separated in two stages. First, all components that are present at a lower temperature than

Methanol is boiled and removed in a light-boiling column. The pure methanol is then distilled overhead in one or more distillation columns. If the columns operate at different pressures, the heat of condensation of the vapors can be used to reduce the methanol content.

Column operating at higher pressure, for heating the column with lower pressure

Pressure can be used.

Some components form azeotropic mixtures with methanol, e.g. acetone,

Ethyl formate, methyl acetate, ethyl acetate and methyl propionate.

According to the invention, in the proposed plant configuration, the exhaust gas stream from the methanol synthesis loop is fed directly into the processing unit as fuel gas after methanol recovery in order to utilize the energy of the electricity. Through this

The residual gas flows from the methanol plant can still be used effectively in the interconnected system.

Fuel gas can be used, thus reducing the need for external gas or avoiding the addition of external gas altogether.

Further preferred embodiments of the invention result from the other features mentioned in the dependent claims.

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In a first embodiment of the process according to the invention, it is provided that the partial stream is treated before being fed into the processing of the carbon-containing material.

The feedstock is fed into a first methanol recovery unit, in which a first methanol-laden stream and a first methanol-poor partial stream are produced. The methanol recovery unit can, in particular, be a methanol scrubbing column.

In a further embodiment of the process according to the invention, it is provided that the crude methanol is depressurized in a low-pressure separator, and that the first methanol-laden stream is fed to the low-pressure separator. It is also conceivable that the first methanol-laden stream is fed directly to the distillation process.

In a further embodiment of the process according to the invention, it can be provided that the partial stream is directed into a hydrogen recovery unit before being fed into the processing of the carbon-containing feedstock, whereby a hydrogen-rich stream and a hydrogen-poor partial stream are produced, and the hydrogen-rich stream is fed into the methanol synthesis.

Hydrogen losses are minimized in this way. When using the combined...

The hydrogen recovery unit and the methanol recovery unit can

The hydrogen recovery unit can be located upstream or downstream of the methanol recovery unit.

In a further preferred embodiment of the inventive process, it is provided that at least a part of the head product is recycled back into the

The carbon-containing feedstock is processed. In this way, the

The top product can be used as fuel gas.

Additionally or alternatively, in a further embodiment of the invention:

The procedure provides that the head product is removed before being returned to a second

methanol recovery unit is directed, with the second

In the methanol recovery unit, a second methanol-laden stream and a second methanol-poor partial stream are generated, with the second methanol-laden stream being the

distillation or is added to the crude methanol before distillation. In the second

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The methanol recovery unit can in particular be a methanol-

The washing column is involved. The overhead product of the distillation column can also be processed after the

Methanol recovery is directed to a scrubbing column for processing, so that the gas stream can be used as fuel gas. This allows valuable products to be extracted from the

The top product is removed and reintroduced into the process elsewhere.

In a further embodiment of the invention, a low-pressure separator is used for

The crude methanol is subject to pressure relief. A [something] falls into the low-pressure separator.

Release gas, whereby the release gas is at least partially used in the distillation and/or processing of biomass or the carbon-containing

The feedstock is added. Before the crude methanol enters the distillation section of the

The system is directed to a lower value in a

The pressure in the low-pressure separator is reduced. This process produces a release gas that still contains significant amounts of methanol, carbon, and hydrogen. To...

To recover methanol, it can be transferred to the first distillation column or to a

methanol scrubbing column.

In a further advantageous embodiment of the method according to the invention, it is provided that a hydrogen stream and a

An oxygen flow is generated and that the hydrogen flow is upstream of the

methanol synthesis or is introduced into methanol synthesis and that the

An oxygen stream is introduced into the carburetor. To increase the carbon yield, it is advisable to add external hydrogen, for example from a

Water electrolysis. In a system configuration with water electrolysis, the oxygen produced during the splitting of water can be used in gasification.

Then there is no other oxygen source, for example from a

An air separation plant (ASU) is necessary.

Furthermore, in a further embodiment of the inventive method, it is provided that an oxygen stream is generated by means of air separation, which is then fed into the

The gas is introduced via a carburetor. Without water electrolysis, additional oxygen can be added using an air separation unit (ASU). This can be advantageous if no external hydrogen is required.

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The aforementioned task is also solved by a plant for the production of

Methanol from a carbon-containing feedstock, comprising at least the following components: a device for processing a carbon-containing feedstock

feedstock; a gasifier for gasification and/or a pyrolysis furnace for

Pyrolysis of the processed carbon-containing feedstock to obtain a

raw synthesis gas; a facility for processing the raw synthesis gas to

Obtaining synthesis gas; a methanol synthesis facility for obtaining

Crude ethanol; optionally a low-pressure separator to relieve the pressure of the

Crude methanol; a distillation to distill the expanded crude ethanol to

Recovery of methanol and a head product; recycling from the facility to the

Methanol synthesis for the facility for the processing of carbon-containing

feedstock. The plant for the production of methanol is set up and designed to carry out a process according to the invention. The previous

Statements concerning the method according to the invention also apply accordingly to the plant according to the invention.

In a first embodiment of the plant according to the invention, a first methanol recovery unit is provided in the return process, wherein in the first

The methanol recovery unit produces an initial methanol-laden stream and an initial methanol-poor partial stream.

In a further embodiment of the system according to the invention, it is provided that a flow-technical connection between the first

methanol recovery unit and the low-pressure separator and/or the

Distillation to introduce the first methanol-laden stream into the

Low-pressure separator, is trained.

In a further embodiment of the inventive system, a

A hydrogen recovery unit is provided, wherein the

Hydrogen recovery unit, fluid-technically combined with the first

is connected to the methanol recovery unit and the facility for processing the carbon-containing feedstock.

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In a further embodiment of the inventive system, a second

Recycling to recycle at least part of the head product into the

A facility for processing the carbon-containing feedstock is provided.

In a further advantageous embodiment of the inventive plant, a second methanol recovery unit is provided, which is located in the flow direction between the head of the distillation and the device for processing the carbon-containing

The raw material is arranged.

Furthermore, in a further embodiment of the inventive system, a third

A return flow from the low-pressure separator to the facility for processing the carbon-containing feedstock is provided for the return of a degassing gas generated in the low-pressure separator.

Unless otherwise stated in individual cases, the various embodiments of the invention mentioned in this application can be advantageously combined with one another.

The invention is described below in exemplary embodiments with reference to the associated

The drawings are explained. They show:

Figure 1 shows a schematic representation of an embodiment of a

Plant or process for the production of

Methanol from biomass

Figure 2 shows a schematic representation of an exemplary embodiment of an optimized plant or process for the production of methanol from biomass and

Figure 3 shows a schematic representation of a further embodiment of an optimized system or method for

Production of methanol from biomass.

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Figure 1 schematically shows a process or plant 1 for the production of methanol from synthesis gas obtained from a carbon-containing feedstock. First, in a processing unit for the carbon-containing feedstock 2, biological material or carbon-rich material is prepared for further processing; in this case,

Biomass. After processing, the biomass is gasified in a gasifier 3 and/or pyrolyzed in a pyrolysis oven (not shown), resulting in a

Raw synthesis gas is obtained. This raw synthesis gas is used in a facility for

Processing of the raw synthesis gas 4 treated to obtain a synthesis gas.

The synthesis gas is then converted to methanol or crude methanol in a methanol synthesis unit 5, which includes at least one reactor 6. Crude methanol leaving reactor 6 contains water and other substances.

Impurities. Therefore, downstream of reactor 6, a

Low-pressure separator 7 is provided. Before the crude methanol enters a

The pressure must be reduced to a lower level in the distillation area of the plant.

The value in the low-pressure separator 7 is reduced. This process produces a flash gas that still contains significant amounts of methanol, carbon, and hydrogen. To reduce this

To recover methanol, it is fed into distillation unit 8. Pure methanol is obtained in distillation unit 8. During distillation unit 8, byproducts are removed,

Process water and unreacted substances are thermally separated from the methanol.

In the present embodiment, a [missing word] is used to provide oxygen.

Air separation unit (ASU) 9 is provided, which supplies oxygen to the carburetor 3.

Figure 2 shows an optimized process or plant 1 for the production of methanol from a carbon-containing feedstock. Compared to the previous

In the embodiment shown in Figure 1, Figure 2 shows a water electrolysis unit 10 instead of the air separation unit (ASU) 9, which provides oxygen for the gasifier and hydrogen for methanol synthesis. CO can be used as a carrier gas for the biomass.

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Furthermore, a first return 11 of at least a partial current, for example a

Exhaust gas stream, from the methanol synthesis plant 5 to the plant for

Processing of the carbon-containing feedstock 2 is planned. In the proposed plant configuration, the exhaust gas stream from the

Methanol synthesis loop after methanol recovery directly as fuel gas of the

The energy is processed to utilize the electricity.

The residual gas flows from the methanol plant can still be used effectively in the interconnected circuits.

Fuel gas can be used, thus reducing the need for external gas or avoiding the addition of external gas altogether.

In the return line 11, a first methanol recovery unit 14 can be provided, in which a first methanol-laden stream and a first methanol-poor partial stream are generated. If—as shown—a low-pressure separator 7 is used to relieve the pressure of the

Since crude methanol is intended, a flow-technical connection can be provided between the first methanol recovery unit 14 and the low-pressure separator 7 in order to transfer the first methanol-laden stream into the

Feed the methanol-laden stream into the low-pressure separator 7. Alternatively or additionally, the methanol-laden stream can also be fed into the distillation process.

Furthermore, a hydrogen recovery unit 15 may be provided, which is fluidically connected to the first methanol recovery unit 14 and the processing unit 2 for the carbon-containing feedstock.

Hydrogen recovery unit 15 can — as shown in Fig. 2 — be the first

The methanol recovery unit 14 may be connected upstream, or — according to an embodiment not shown — downstream.

A third return path 13, represented as a dashed line, is also conceivable, which is from

Low-pressure separator 7 in the facility for the treatment of the carbon-containing

The second input material is directed.

In the embodiment shown in Figure 3, an additional second

Recirculation 12 is provided, through which at least a part of the head product is returned to the

The facility for processing the carbon-containing feedstock 2 is being installed.

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In one way, the overhead product can be used as a fuel gas. In the second

In the return 13, a second methanol recovery unit 16 can be provided, which is located in the direction of flow between the head of the distillation 8 and the device for

The processing of the carbon-containing feedstock 2 is arranged.

In the embodiment shown in Figure 3, a third return 13 can also be provided, through which expansion gas from the low-pressure separator 7 is returned to the device for

The carbon-containing feedstock 2 is processed. The return 13 can be achieved by directly introducing the flash gas into the facility.

Processing of the carbon-containing feedstock 2 and/or by introduction into the second methanol recovery unit 16.

The return 13 can be used as an alternative or additional method to initiate part of the

The release of the expansion gas into distillation 8 takes place.

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Reference List 1 Plant 2 Carbon-Containing Feedstock Processing Unit 3 Gasifier 4 Raw Synthesis Gas Processing Unit 0 5 Methanol Synthesis Unit 6 Reactor 7 Low-Pressure Separator 8 Distillation 9 Air Separation Unit (ASU) 10 Water Electrolysis 11 First Recirculation 12 Second Recirculation 13 Third Recirculation 14 First Methanol Recovery Unit 15 Hydrogen Recovery Unit 16 Second Methanol Recovery Unit

Claims (16)

230557 P00LU 09.10.2024 LU103404 Patent claims 1. A process for producing methanol from a carbon-containing feedstock, comprising at least the following steps: a. Processing of at least one carbon-containing feedstock, b. Gasification in a gasifier (3) and/or pyrolysis in a pyrolysis furnace of the processed feedstock to obtain a raw synthesis gas; C. Processing of the raw synthesis gas to obtain synthesis gas; d. Methanol synthesis to obtain crude methanol; e. Distillation of the crude methanol to obtain methanol and a head product; f. Extraction of a partial stream from the methanol synthesis and feeding at least a part of the partial stream to the processing of the carbon-containing feedstock. 2. Method according to claim 1, characterized in that the partial stream is directed into a first methanol recovery unit (14) before being fed into the processing of the carbon-containing feedstock, wherein a first methanol-loaded stream and a first methanol-poor partial stream are generated in the first methanol recovery unit (14). 3. Method according to claim 2, characterized in that the crude methanol is depressurized in a low-pressure separator (7) and that the first methanol-loaded stream is fed to the low-pressure separator (7), or that the first methanol-loaded stream is fed to the distillation (8). 4. Method according to one of claims 1 to 3, characterized in that the partial stream is directed into a hydrogen recovery unit (15) before being fed into the processing of the carbon-containing feedstock, wherein 230557 P00LU 09.10.2024 -2- LU103404 a hydrogen-rich stream and a hydrogen-poor partial stream are generated, wherein the hydrogen-rich stream is fed to the methanol synthesis (5). 5. Method according to one of claims 1 to 4, characterized in that at least a part of the head product is recycled into the processing of the carbon-containing feedstock. 6. Method according to claim 5, characterized in that the overhead product is directed to a second methanol recovery unit (16) before being recycled, wherein a second methanol-loaded stream and a second methanol-poor partial stream are generated in the second methanol recovery unit (16), wherein the second methanol-loaded stream is fed to the distillation (8) or to the crude methanol before distillation (8). 7. Method according to claim 5 or 6, characterized in that a flash gas is produced in the low-pressure separator (7) and that the flash gas is at least partially supplied to the distillation (8) and/or the processing of the carbon-containing feedstock. 0 8. Method according to one of claims 1 to 7, characterized in that a hydrogen stream and an oxygen stream are generated by means of water electrolysis (10) and that the hydrogen stream is introduced upstream of the methanol synthesis (5) or into the methanol synthesis (5) and that at least a part of the oxygen stream is introduced into the gasifier (3). 9. Method according to one of claims 1 to 7, characterized in that an oxygen stream is generated by means of air separation and introduced into the carburetor (3). 10. Plant (1) for the production of methanol from a carbon-containing feedstock, comprising at least the following components: 230557 P00LU 09.10.2024 -3- LU103404 a. a facility for the processing of at least one carbon-containing feedstock (2); b. a gasifier (3) for gasification and/or a pyrolysis furnace for pyrolysis of the processed carbon-containing feedstock to obtain a raw synthesis gas; C. a device for processing the raw synthesis gas (4) to obtain a synthesis gas; d. a methanol synthesis apparatus (5) for the production of crude methanol; e. a distillation (8) to distill the relaxed crude methanol to obtain methanol and an overhead product; f. a recirculation (11) from the methanol synthesis facility (5) to the carbon-containing feedstock processing facility. 11. Plant (1) according to claim 10, characterized in that a first methanol recovery unit (14) is provided in the return (11), wherein a first methanol-loaded stream and a first methanol-poor partial stream are generated in the first methanol recovery unit (14). 12. Plant (1) according to claim 11, characterized in that a low-pressure separator (7) is provided for the depressurization of the crude methanol and that a flow-technical connection between the first methanol recovery unit (14) and the low-pressure separator (7) is provided for supplying the first methanol-loaded stream into the low-pressure separator (7). 13. Plant (1) according to claim 11 or 12, characterized in that a hydrogen recovery unit (15) is provided, and that the hydrogen recovery unit (15) is fluidically connected to the first methanol recovery unit (14) and device for processing (2) the carbon-containing feedstock. 14. Plant (1) according to one of claims 10 to 13, characterized in that a second return (12) is provided for returning at least a part of the 230557 P00LU 09.10.2024 -4- LU103404 Head product is intended to be fed into the facility for the processing of the carbon-containing feedstock (2). 15. Plant (1) according to claim 14, characterized in that a second methanol recovery unit (16) is provided, which is arranged in the direction of flow between the head of the distillation (8) and the device for processing the carbon-containing feedstock (2). 16. Plant (1) according to claim 14 or 15, characterized in that a third return (13) from the low-pressure separator (7) to the device for processing the carbon-containing feedstock (2) is provided for the return of a flash gas accumulating in the low-pressure separator (7).