Method for reducing co2 emission in a methanol plant using combined fuel fired reforming and electrical reforming

Abstract

A process and system are provided for the preparation of syngas and methanol with reduced carbon dioxide emissions. The method comprises dividing a hydrocarbon and steam feed into two streams, one subjected to fuel fired reforming and the other to electrical reforming. At least a portion of the synthesis gas from the electrical reforming is processed in a shift section and a carbon dioxide removal section, producing a hydrogen rich gas and a carbon dioxide rich gas. The hydrogen rich gas is used as fuel in the fuel fired reforming process, reducing the need for hydrocarbon fuel. The system allows for flexible adjustment of process streams and integration with methanol synthesis, enabling significant reductions in natural gas and oxygen consumption and overall carbon dioxide emissions.

Description

[0001] REF. NO: [02965-WO ]

[0002] 1

[0003] Method for Reducing CO2 Emission in a Methanol Plant Using Combined Fuel Fired Reforming and Electrical Reforming

[0004] Background

[0005] The invention relates to the field of syngas and methanol production, specifically to a method for reducing carbon dioxide emissions from a syngas and / or a methanol plant based on fuel fired reforming of a part of the hydrocarbons and steam feed mixture and in parallel to the fuel fired reforming a remaining part of the hydrocarbons and steam feed mixture by electrical reforming.

[0006] Summary

[0007] The invention provides a method for reducing carbon dioxide emissions to the atmosphere in a synthesis gas plant and / or a methanol plant by dividing the natural gas feedstock into two parts: one part goes to the fuel fired reforming and the remaining part goes to the electrical reforming. Both the fuel fired reforming and the electrical reforming produces effluent gas known as synthesis gas or syngas. From the electrical reforming at least part of the synthesis gas is introduced into a water gas shift section followed by a carbon dioxide removal section. The hydrogen rich gas from the carbon dioxide removal section is used as fuel in the burners of the fuel fired reforming substituting hydrocarbon fuel such as natural gas fuel.

[0008] This method allows for considerable savings in natural gas and oxygen fuel, and significantly reduces carbon dioxide emissions.

[0009] Disclosed herein is a process for the preparation of syngas. The process comprises preparing a first process stream comprising hydrocarbons and steam and preparing a second process stream comprising hydrocarbons and steam. The first process stream is provided to a fuel fired reforming process to provide a first stream of synthesis gas. The second process stream is provided to an electrical reforming process to provide a second stream of synthesis gas. At least a part of the second stream of the synthesis gas is provided to a water gas shift section and subsequently to a carbon dioxide removal section to provide a stream of hydrogen rich gas and a stream of carbon dioxide rich gas. At least a portion of the hydrogen rich gas is provided to the fuel fired reforming process as fuel for the fuel fired reforming process and / or as fuel for fired heaters. A synthesis gas product stream is thereby provided comprising at least the first stream of synthesis gas. The process may additionally comprise the step of providing the synthesis gas product stream to a methanol synthesis unit for the provision of a methanol product. REF. NO: [02965-WO ]

[0010] 2

[0011] Disclosed herein is also a synthesis gas plant comprising a fuel fired reforming unit and an electrical reforming unit. The fuel fired reforming unit configured to receive a first stream of steam, a first hydrocarbon containing gas and optionally a first oxygen rich gas and to provide a first stream of synthesis gas. The electrical reforming unit configured to receive a second stream of hydrocarbon containing gas and a second stream of steam and to provide a second stream of synthesis gas. The plant further comprising a shift section and a carbon dioxide removal section coupled to the electrical reforming unit and configured to provide a hydrogen rich gas stream and a carbon dioxide rich gas stream. The fuel fired reforming unit is configured to receive and utilize at least a portion of the hydrogen rich gas stream as a fuel. The plant is thereby suitable for providing a synthesis gas product stream comprising at least a portion of the first stream of synthesis gas. The plant may additionally comprise a methanol synthesis unit configured to receive at least a portion of the synthesis gas product stream.

[0012] Disclosed herein is also a method of revamping an existing synthesis gas plant having a fuel fired reforming unit. In the revamping method an electrical reformer is provided and fluidly connected to a shift section. The shift section is further fluidly connected to a carbon dioxide removal section. The carbon dioxide removal section is connected to the fuel fired reformer unit of the synthesis gas plant such that the synthesis gas plant can utilize at least a portion of hydrogen rich gas from the carbon dioxide removal section as a fuel.

[0013] Disclosed herein is also a control system for controlling the synthesis gas plant having a fuel fired reformer, an electrical reformer, a shift section and a carbon dioxide removal section. The control system comprises a controller being in communication with a plurality of valves in the synthesis gas plant and being operable to receive an input signal. The control system is configured to distribute the feed of hydrocarbon containing gas to the fuel fired reformer and the electrical reformer and / or a flow of hydrogen rich gas from the carbon dioxide removal section to the fuel fired reformer.

[0014] Brief description of drawings

[0015] The above and other features and advantages of the present invention will become readily apparent to those skilled in the art by the following detailed description of example embodiments thereof with reference to the attached drawings, in which:

[0016] FIG. 1 is a process diagram illustrating the syngas production method integrating fuel fired reforming, electrical reforming, and carbon dioxide management. REF. NO: [02965-WO ]

[0017] 3

[0018] FIG. 2 is a process flow diagram illustrating the methanol production process integrating fuel fired and electrical reforming with carbon dioxide reduction.

[0019] Detailed description

[0020] Various example embodiments and details are described hereinafter, with reference to the figures when relevant. It should be noted that the figures may or may not be drawn to scale and that elements of similar structures or functions are represented by like reference numerals throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the embodiments, and the functionalities associated therewith. They are not intended as an exhaustive description of the invention or as a limitation on the scope of the invention or the physical appearance of the invention. In addition, an illustrated embodiment does not need to have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated, or if not so explicitly described.

[0021] According to a first aspect the invention relates to a process for the preparation of syngas. In particular the syngas may be suitable for methanol synthesis. In particular the syngas may have a gas module of between 1.9 to 2.1, such as around 2.05. The method may comprise the steps of preparing a first process stream comprising hydrocarbons and steam and preparing a second process stream comprising hydrocarbons and steam. The first process stream may be provided to a fuel fired reforming process to provide a first stream of synthesis gas. The second process stream may be provided to an electrical reforming process to provide a second stream of synthesis gas. At least a part of the second stream of the synthesis gas may be provided to a water gas shift section and / or to a carbon dioxide removal section to provide a stream of hydrogen rich gas and a stream of carbon dioxide rich gas. At least a portion of the first stream of synthesis gas may be provided as a synthesis gas product stream. At least part of the hydrogen rich gas from the carbon dioxide removal section and / or the water gas shift section may be provided as heating fuel for the fuel fired reforming process and / or as fuel for fired heaters.

[0022] In a preferred embodiment the synthesis gas product stream is provided to a methanol synthesis unit for the preparation of a methanol product. In particular the method for the preparation of methanol may comprise the steps of: a) preparing a first process stream comprising hydrocarbons and steam; b) preparing a second process stream comprising hydrocarbons and steam; REF. NO: [02965-WO ]

[0023] 4 c) passing the first process stream to a fuel fired reforming process to provide a first stream of synthesis gas; d) passing the second process stream to an electrical reforming process to provide a second stream of synthesis gas; e) passing the first stream of synthesis gas to a methanol synthesis unit; f) passing at least a part of the second stream of synthesis gas to a water gas shift section and then into a carbon dioxide removal section to provide a stream of hydrogen rich gas and a stream of carbon dioxide rich gas; g) introducing at least part of the hydrogen rich gas from step (f) into step (c) as heating fuel for the fuel fired reforming process or as fuel for fired heaters.

[0024] In one or more embodiments the fuel fired reforming process may comprise a fuel fired reforming unit and may comprise either of the following routes I, II or III:

[0025] I. A primary reforming step such as a in a steam methane reformer with natural gas fired as fuel.

[0026] II. A primary reforming step such as a in a steam methane reformer with natural gas fired as fuel followed by an oxygen fired secondary reforming step.

[0027] III. An oxygen fired autothermal reforming step typically with an associated fired heater for preheating of the gas mixture. The fired heater could suitably operate on natural gas as fuel.

[0028] Preheating of gas before the reformers could suitably be done in an associated convective section of the natural gas fired steam methane reformer, or by a fired heater or by electrical heating.

[0029] Primary reforming is a process used to produce a synthesis gas from steam and hydrocarbons such as natural gas or methane. It involves the reaction of hydrocarbons with steam in the presence of a catalyst to produce a mixture of hydrogen, carbon monoxide, carbon dioxide and water as well as unconverted methane in a fired reformer. This steam reforming process is also known as primary reforming or one step reforming. This steam reforming reactor is fired by burners on the outside of catalyst filled tubes using either REF. NO: [02965-WO ]

[0030] 5 hydrocarbons such as natural gas, methane and / or waste gases with heating value as fuel. The so-called gas module defined as M = (H2-CO2) / (CO+CO2) of the synthesis gas is typically in the range from 2.7 to 3.1.

[0031] Secondary reforming, on the other hand, is a subsequent step to the primary reforming step. It involves the further conversion of gas mixture from the primary reforming step into additional hydrogen and carbon monoxide in the presence of a catalyst. The gas module M of the synthesis gas from the secondary reforming is typically in the range from 2.0 to 2.2. Fuel to the secondary reformer is an oxygen rich gas, typically containing more than 98 mole% oxygen as O2, added to the gas mixture from the primary reforming step, typically through a burner. Therefore, the fuel for secondary reforming is in direct contact with the effluent gas mixture from the primary reforming. The primary reforming step in combination with a secondary reforming step is also known as two step reforming or combined reforming.

[0032] Steam reforming may also be performed by means of autothermal reforming. It is an alternative to one step and two step reforming processes described above in the sense that it comprises a reactor with oxygen fuel, typically containing more than 98 mole% oxygen as O2, in direct contact with the mixture of hydrocarbons and steam inside the reactor in the presence of a catalyst. The molar gas module M of the synthesis gas from autothermal reforming is typically in the range from 1.6 to 1.9.

[0033] Autothermal reforming may also be used in combination with a heat exchange reforming (HTER) where the hydrocarbon feed is introduced into a number of catalyst filled tubes in a heat exchange reforming unit where a first reforming step takes place. The partially reformed gas is then sent to the autothermal reforming unit for subsequent reforming. The outlet gas from the autothermal reforming unit is sent to the heat exchange reforming unit to a volume exterior of the tubes to indirectly provide heat energy to the catalyst filled tubes.

[0034] Thus, in an embodiment of the invention the fuel fired reforming process comprises primary reforming or primary and secondary reforming or autothermal reforming optionally in combination with heat exchange reforming.

[0035] In electrical reforming the mixture of hydrocarbons and steam is heated by the electrical heating elements, raising the temperature to the desired level for the steam reforming reactions to occur. The hydrocarbons react with steam in the presence of a catalyst, typically a nickel-based catalyst, to produce synthesis gas comprising hydrogen, carbon monoxide and carbon dioxide and water as well as unconverted methane. Preferably, the electrical reforming section is powered by renewable electrical power. Optionally, a number of electrical REF. NO: [02965-WO ]

[0036] 6 heaters are installed to fulfill the heat balance requirements for preheating of the gas mixture before it enters the electrical reformer.

[0037] For any of the fuel fired reforming or electrical reforming the produced water from the reforming reactors is suitably removed in downstream cooling and separation units before further processing of the synthesis gas, for instance in a methanol synthesis unit.

[0038] The water gas shift section comprises one or more shift reaction steps such as an adiabatic shift reactor. The shift section may comprise a high temperature shift reactor, a medium temperature shift reactor, and / or a low temperature shift reactor, preferably connected in series. At least part of the second stream of synthesis gas from the electric reforming step is mixed with steam and introduced into a shift reactor containing catalyst suitable for conversion of steam and carbon monoxide into hydrogen and carbon dioxide. After cooling of the effluent gas, water is separated from the gas. The effluent gas is introduced into the carbon dioxide removal section such as an amine wash section. Here, the effluent gas is separated into a carbon dioxide rich gas and a hydrogen rich gas. The carbon dioxide rich gas containing the majority of the carbon dioxide, and typically having a concentration of more than 98 mole% of carbon dioxide. The hydrogen rich gas comprising primarily hydrogen (typically about 85 mole% as H2) and minor components such as methane and carbon monoxide (about 15 mole% in total). A portion of the hydrogen rich gas may be sent to the burners of the fuel fired reforming section thereby substituting carbon rich fuel, such as natural gas that would otherwise be used, thereby reducing the carbon dioxide emission to the atmosphere. Part or all of the carbon dioxide rich gas could be exported out of the system such as sequestration or exported to pipeline. A part of or all of the carbon dioxide rich gas may be sent to a methanol synthesis unit together with the synthesis gas product stream and / or the first stream of synthesis gas from the fuel fired reforming. The synthesis gas product stream may optionally also comprise a part of the second stream of synthesis gas from the electrical reforming. In this way, depending on the type of fuel fired reforming, the fuel fired reforming process being primary reforming only or primary and secondary reforming or autothermal reforming, the gas module of the combined feed gas to the methanol synthesis unit can be optimized.

[0039] Methanol synthesis gas has preferably a composition corresponding to the molar gas module (M = (H2-CO2) / (CO+CO2)) of 1.9-3.0, more preferably 1.9-2.1.

[0040] Typically, around 80 V / V%, such as 75-85 V / V% of the hydrocarbon feed may be provided to and reformed in the fuel fired reformer. In periods with high availability of renewable energy it may be beneficial to provide a larger portion of the hydrocarbon feed to the electrical reforming. As an example, up to 40 V / V% of the hydrocarbon feed may be provided to the REF. NO: [02965-WO ]

[0041] 7 electrical reforming and the remaining hydrocarbon feed being provided to the fuel fired reformer. In one or more embodiments 10 to 40 V / V% of the hydrocarbon feed is provided to the electrical reforming and 60 to 90 V / V% is provided to the fuel fired reforming.

[0042] The composition of the synthesis gas product stream, i.e. the amount of synthesis gas from the first stream of synthesis gas, synthesis gas from the second stream of synthesis gas and / or the amount of carbon dioxide from the carbon dioxide rich gas stream can be adjusted based on energy availability while maintaining a molar gas module at the desired level.

[0043] In an embodiment of the invention, hydrogen rich gas is introduced to the burners of the fuel fired reforming thereby substituting carbon rich fuel, such as natural gas that would otherwise be used, thereby reducing the carbon dioxide emission.

[0044] In an embodiment of the invention, carbon dioxide rich gas could be exported out of the system such as sequestration or exported to pipeline.

[0045] In an embodiment of the invention, if the fuel fired reforming is a primary reforming process thus having a high gas module from 2.7 to 3.1 of the first stream synthesis gas, at least part of the carbon dioxide rich gas from the carbon dioxide removal section could suitably be added to the synthesis gas product stream and mixed with the first stream of synthesis gas to reduce the gas module to be in the range 1.9 to 2.1 such as 2.05, which is suitable for being provided to the methanol synthesis unit.

[0046] In an embodiment of the invention, if the fuel fired reforming unit is an autothermal reformer, thus providing a first stream of synthesis gas having a low gas module in the range from 1.6 to 1.9, at least a part of the second stream of synthesis gas from the electrical reforming unit may suitably be provided to the synthesis gas product stream and mixed with the first stream of synthesis gas to increase the gas module to be in the range 1.9 to 2.1 such as 2.05, which is suitable for the methanol synthesis unit.

[0047] In an embodiment of the invention, at least part of the second stream of synthesis gas and / or at least part of the carbon dioxide rich gas may be added to the first stream of synthesis gas obtaining a gas module in the range 1.9 to 2.1 such as 2.05, which is suitable for being provided to the methanol synthesis unit. In this way the gas module can be optimized for any type of fuel fired reforming process, the fuel fired reforming process being primary reforming only or primary and secondary reforming or autothermal reforming, and obtaining a reduction of the emitted carbon dioxide by still having hydrogen rich fuel for the burners via the water gas shift section and carbon dioxide removal section. REF. NO: [02965-WO ]

[0048] 8

[0049] In an embodiment of the invention, at least part of the waste gases from the methanol synthesis unit and / or the distillation section could be introduced into the water gas shift section. The waste gases could comprise the purge gas and / or flash gas from the methanol synthesis unit and / or the off gas from the distillation section all containing carbon compounds. In this way the carbon compounds could be exported from the system via the carbon dioxide rich gas from the carbon dioxide removal section instead of going to the atmosphere via the flue gas from the burners of the fuel fired reforming. This enables for the fuel to be comprised solely of hydrogen rich gas from the carbon dioxide removal section thereby enabling a very low emission of carbon dioxide to the atmosphere.

[0050] In an embodiment of the invention, steam is added in an amount into the first and / or second hydrocarbon streams to provide a steam / carbon molar ratio typically in the range of 0.5 to 3.0.

[0051] In an embodiment additional amounts of carbon dioxide rich gas from an external source may be introduced either into the first process stream and / or second process stream comprising hydrocarbons and steam or into the methanol synthesis unit together with the synthesis gas product stream.

[0052] In one or more embodiments the carbon dioxide containing flue gas from the fuel fired reformer may be further processed via a second carbon dioxide removal section to remove carbon dioxide from the flue gas and to provide a second carbon dioxide rich gas. A portion of the second carbon dioxide rich gas from the flue gas may be provided to the first process stream comprising hydrocarbons, the second process stream comprising hydrocarbons and / or the synthesis gas product stream. The second carbon dioxide rich gas may thereby be utilized to control the gas module of the synthesis gas product stream optionally upstream of the methanol synthesis unit.

[0053] In another aspect, the invention provides a method for revamping an existing synthesis gas plant, particularly one that already comprises a fuel fired reforming unit. This embodiment enables the integration of electrical reforming and advanced carbon management into established facilities, thereby reducing carbon dioxide emissions and improving process flexibility.

[0054] According to this method, an electrical reformer is provided and fluidly connected to a shift section. The shift section and a carbon dioxide removal section may already be present in the existing synthesis gas plant, or they may be added as part of the revamp, depending on the original plant configuration. The outlet of the electrical reformer is connected to the inlet of the shift section, which is configured to perform a water gas shift reaction, converting carbon REF. NO: [02965-WO ]

[0055] 9 monoxide and steam into hydrogen and carbon dioxide. The outlet of the shift section is then fluidly connected to a carbon dioxide removal section, such as an amine wash unit, which separates the effluent gas into a hydrogen rich gas stream and a carbon dioxide rich gas stream.

[0056] The hydrogen rich gas stream, obtained from the first outlet of the carbon dioxide removal section, is fluidly connected to the fuel fired reformer unit of the synthesis gas plant. This allows the hydrogen rich gas to be used as a fuel in the burners of the fuel fired reformer, substituting for natural gas or other hydrocarbon fuels, and thereby reducing the overall carbon dioxide emissions from the plant.

[0057] In a further embodiment, the method may include fluidly connecting the second outlet of the carbon dioxide removal section, which provides the carbon dioxide rich gas stream, to the outlet of the fuel fired reforming unit. This enables the carbon dioxide rich gas to be combined with the synthesis gas product stream, allowing for adjustment of the gas composition, such as the gas module, to meet the requirements of downstream processes like methanol synthesis.

[0058] Additionally, the method may comprise fluidly connecting the outlet of the electrical reformer to the outlet of the fuel fired reforming unit. This configuration allows at least a portion of the synthesis gas produced in the electrical reformer to be combined with the synthesis gas from the fuel fired reformer, providing further flexibility in controlling the composition of the synthesis gas product stream and optimizing the process for various operational scenarios.

[0059] In one or more embodiments one or more electrical heaters are configured to preheat the first process stream and / or the second process stream. In one or more electrical heaters may additionally or alternatively be provided and configured to preheat the first stream of steam, the first hydrocarbon containing gas, the first oxygen rich gas, the second stream of hydrocarbon containing gas and / or the second stream of steam.

[0060] In one or more embodiments of the invention, the system may comprise a number of valves configured to control the flow of various process streams. These valves enable precise regulation and dynamic adjustment of the process in response to operational requirements or external factors such as the availability of renewable energy or changes in product demand.

[0061] As an example, one or more valves may be installed to control the division of the natural gas feed between the first process stream directed to the fuel fired reforming unit and the second REF. NO: [02965-WO ]

[0062] 10 process stream directed to the electrical reforming unit. By adjusting these valves, the operator can vary the proportion of hydrocarbons processed in each reforming section.

[0063] One or more valves may be provided to regulate the flow of steam into each process stream, allowing for adjustment of the steam-to-carbon ratio to maintain optimal reforming conditions and product gas composition. One or more valves may be provided to direct a portion of the second stream of synthesis gas from the electrical reforming unit either to the shift and carbon dioxide removal section or directly to the synthesis gas product stream.

[0064] One or more valves may be provided to control the flow of the hydrogen rich gas from the carbon dioxide removal section into the burners of the fuel fired reforming unit and / or provide a hydrogen rich gas product stream. Similarly, one or more valves may be provided to manage the addition of carbon dioxide rich gas to the synthesis gas product stream, and / or to export or sequestration.

[0065] In a further aspect, the invention provides a control system for operating the synthesis gas plant. The control system comprises a controller in communication with the one or more valves. The controller is operable to receive input signals, such as an input signal indicative of the availability of renewable power and / or a desired concentration or composition of the synthesis gas product stream.

[0066] Based on the input signals, the controller is configured to control the valves and regulate the distribution of hydrocarbon containing gas between the fuel fired reformer and the electrical reformer, as well as the flow of hydrogen rich gas from the carbon dioxide removal section to the fuel fired reformer. The control system may also manage the introduction of carbon dioxide rich gas into the process streams or product stream, and the operation of electric heaters if present.

[0067] Turning now to Fig. 1 presenting a process for the production of synthesis gas (syngas) according to an embodiment of the invention. In the process fuel fired reforming and electrical reforming is used in combination to produce synthesis gas while providing carbon dioxide management. A hydrocarbon containing gas in the form of a natural gas feed 1 is provided. The natural gas feed 1 is divided into two separate process streams. Each stream is combined with steam 2a, 2b to form two feed mixtures, i.e. a first process stream 8 and a second process stream 9. It should be said that the steam 2a, 2b, may be provided as a single stream to the natural gas feed 1 before separating into two separate process streams.

[0068] The first process stream 8, comprising natural gas and steam, is directed to the fuel fired reforming unit (C). In this section, the first process stream 8 undergoes reforming in the REF. NO: [02965-WO ]

[0069] 11 presence of a catalyst, with heat supplied by burners using natural gas or hydrogen-rich gas as fuel. The fuel fired reforming unit (C) produces a first stream of synthesis gas 21, which is subsequently directed towards the synthesis gas product stream 20. The reforming process also generates a flue gas stream 10, which comprises carbon dioxide. The flue gas stream 10 may be further processed or managed as described in the invention.

[0070] The second process stream 9 comprising natural gas and steam, is introduced into the electrical reforming unit (A). Here, electrical energy 4, preferably from renewable sources, is used to heat the second process stream 9 to the required temperature for reforming reactions to occur in presence of a catalyst. The electrical reforming unit (A) produces a second stream of synthesis gas 5. At least a portion of the second stream of synthesis gas 5 is provided to a shift section and carbon dioxide removal option (B). In the shift section, the synthesis gas reacts with steam to convert carbon monoxide to hydrogen and carbon dioxide. The effluent is processed in the carbon dioxide removal section, resulting in a hydrogen rich gas stream 6 and a carbon dioxide rich gas stream 7.

[0071] A portion of the hydrogen rich gas stream 6 may be introduced as fuel into the fuel fired reforming unit (C) and / or used as fuel for fired heaters. One or more remaining portions of the hydrogen rich gas stream 6b, may be utilized as a hydrogen feed in parts of the process e.g. in a hydrogenation section. Alternatively, or additionally a portion of the hydrogen rich gas 6b may be exported as a hydrogen product. This may require further purification of the hydrogen e.g. via a pressure swing absorption (PSA) unit. A portion of the carbon dioxide rich gas stream 7 may be added to the synthesis gas product stream 20 to optimize the gas composition for downstream processes, i.e. adjust the gas module. A portion of the carbon dioxide rich gas stream 7b may alternatively or additionally be exported or sequestered as needed. Additionally, the process allows for the optional import of external carbon dioxide 30, which can be introduced into the system to further adjust the composition of the synthesis gas product stream 20.

[0072] The synthesis gas product stream 20 comprises at least the first stream of synthesis gas 21 from the fuel fired reforming unit (C), and may also include portions of the second stream of synthesis gas 5 from the electrical reforming unit (A) and / or the carbon dioxide rich gas stream 7. This flexibility enables the process to maintain an optimal gas module for methanol synthesis or other downstream applications, while achieving significant reductions in natural gas and oxygen consumption, as well as carbon dioxide emissions.

[0073] Turning now to Fig. 2 showing another embodiment of the invention. Fig. 2 illustrates a process for methanol production, integrating fuel fired reforming and electrical reforming with carbon dioxide reduction. A natural gas feed 100 is split into two process streams, each REF. NO: [02965-WO ]

[0074] 12 combined with steam 102a and 102b. The first process stream 108 is provided to the fuel fired reforming unit C, producing a first stream of synthesis gas 121 and flue gas 110. The second process stream 109 is provided to the electrical reforming unit A, powered by electrical energy 104, generating a second stream of synthesis gas 105.

[0075] A portion of the second stream 105 is processed in the shift section and carbon dioxide removal unit B, providing a hydrogen rich gas 106 and a carbon dioxide rich gas 130. At least a portion of the hydrogen rich gas 106 is used as fuel in the fuel fired reforming unit C, reducing natural gas consumption and emissions. The carbon dioxide rich gas 130 can be added to the synthesis gas product stream 120, exported, or sequestered. The process also allows for external carbon dioxide import 130 to further adjust the gas composition.

[0076] The synthesis gas product stream 120, which may include streams 121, 105, and 130, is sent to the methanol synthesis unit D, producing a raw methanol stream 131. This is purified in the distillation section E to yield methanol product 132, with a purge stream 133 for process stability.

[0077] The methanol synthesis unit D may comprise a methanol loop having a methanol reactor, such as a boiling water reactor. The methanol reactor being configured to receive the synthesis gas product stream, optionally after being heated in one or more heat exchangers, and produce and output a first effluent stream comprising methanol. The first effluent stream may undergo one or more cooling steps, such as in heat exchangers, before being separated, such as in a condenser, into a raw methanol stream 131 and a second effluent stream. The second effluent stream may be recirculated to the methanol reactor. The raw methanol stream 131 may be provided to the distillation section E. The distillation section E may comprise a number of distillation columns and optionally a number heat exchangers in which the raw methanol stream 131 is purified into a methanol product stream 132.

[0078] Example 1

[0079] A specific embodiment of the invention with a fuel fired reforming process in parallel to an electrical reforming process is shown in Fig. 1 which shows a simplified flowsheet of the process. In this specific embodiment of the invention the following settings are used:

[0080] • The fuel fired reforming process is of the combined reforming type.

[0081] • The hydrocarbon feedstock and the hydrocarbon fuel for the fuel fired reforming process is natural gas. REF. NO: [02965-WO ]

[0082] 13

[0083] • App. 80% of the hydrocarbons in the first and second process streams in total are sent to the fuel fired reforming and the remaining part is sent to the electrical reforming.

[0084] • App. 15% of the second synthesis gas from the electrical reforming is sent to the water gas shift section and the remaining part is added to the first stream of synthesis gas.

[0085] • All of the carbon dioxide rich gas is added to the first stream of synthesis gas.

[0086] By evaluating the invented case and comparing it to a base case considerable savings can be achieved (for an unchanged methanol production of 5000 metric tonnes per day) : • Total natural gas (process feed and fuel) : 6.5 % saving

[0087] • Oxygen fuel for secondary reformer: 7.1 % saving

[0088] • CO2 emission : 38.8 % saving.

[0089] • 122 MW of electrical power is needed for electrical reformer and electric heaters. This power is intended to be renewable electrical power. A comparison of this concept with the base case is shown in Table 1 : REF. NO: [02965-WO ]

[0090] 14

[0091] REF. NO: [02965-WO ]

[0092] 15

[0093] List of reference numbers REF. NO: [02965-WO ]

[0094] 16 REF. NO: [02965-WO ]

[0095] 17

Claims

REF. NO: [02965-WO ]18Claims1. Process for the preparation of methanol, comprising the steps of a) preparing a first process stream comprising hydrocarbons and steam; b) preparing a second process stream comprising hydrocarbons and steam c) passing the first process stream to a fuel fired reforming process to provide a first stream of synthesis gas; d) passing the second process stream to an electrical reforming process to provide a second stream of synthesis gas; e) passing at least a part of the second stream of synthesis gas to a water gas shift section and then into a carbon dioxide removal section to provide a stream of hydrogen rich gas and a stream of carbon dioxide rich gas; f) introducing at least part of the hydrogen rich gas from step (e) into step (c) as heating fuel for the fuel fired reforming process and / or as fuel for fired heaters. g) providing a synthesis gas product stream comprising the first stream of synthesis gas. f) providing the synthesis gas product stream to a methanol synthesis unit.

2. The process of claim 1, wherein the electrical reforming process is at least partially powered by renewable energy.

3. The process of claim 1 to 2, wherein the fuel fired reforming process comprises primary reforming, primary and secondary reforming, or autothermal reforming.REF. NO: [02965-WO ]194. The process of any one of claims 1 to 3, wherein steam is added into the first process stream and second process stream in an amount to provide a steam / carbon molar ratio in the range of 0.5 to 3.0.

5. The process of any one of claims 1 to 4, wherein at least a part of the carbon dioxide rich gas is provided to the synthesis gas product stream of step g).

6. The process according to any of claims 1 to 5, wherein the carbon dioxide rich gas is provided to the synthesis gas product stream to provide a synthesis gas having a gas module M = (H2-CO2) / (CO+CO2) between 1.9 and 2.1, such as 2.05.

7. The process according to any one of claims 1 to 6, wherein at least a part of the second stream of synthesis gas from step (d) is provided to the synthesis gas product stream of step g).

8. The process of according to any one of claims 1 to 7, wherein carbon dioxide rich gas from an external source and / or a portion of the carbon dioxide from the carbon dioxide containing flue gas from the fuel fired reforming process is provided to the synthesis gas product stream of step g) and / or to the first and / or second process stream.

9. A system for manufacturing methanol comprising• a fuel fired reforming unit having an inlet and an outlet and configured to receive a first stream of steam, a first hydrocarbon containing gas and optionally a first oxygen rich gas, the fuel fired reforming unit configured to provide a first stream of synthesis gas through the outlet;REF. NO: [02965-WO ]20• an electrical reforming unit having an inlet and outlet and configured to receive a second stream of hydrocarbon containing gas and a second stream of steam, the electrically reforming unit configured to provide a second stream of synthesis gas through the outlet;• a shift section and a carbon dioxide removal section coupled to the electrical reforming unit outlet and configured to provide a hydrogen rich gas stream and a carbon dioxide rich gas stream;• wherein the synthesis gas plant is configured to provide a synthesis gas product stream comprising at least a portion of the first stream of synthesis gas;• wherein the fuel fired reforming unit is configured to receive at least a portion of the hydrogen rich gas stream and utilize as a fuel; and• wherein the system further comprises a methanol synthesis unit configured to receive at least a portion of the synthesis gas product stream.

10. The system according to claim 9 wherein the fuel fired reforming unit comprises- a primary reforming unit;- a primary reforming unit and a secondary reforming unit; or- an autothermal reforming unit.

11. The system according to any one of claims 9 to 10, wherein the synthesis gas product stream is configured to receive at least a portion of the carbon dioxide rich gas stream.

12. The system according to any one of claims 9 to 11, wherein the synthesis gas product stream is configured to receive at least a portion of the second stream of synthesis gas.REF. NO: [02965-WO ]2113. The system according to any one of claim 9 to 12 configured to receive a second carbon dioxide rich gas and preferably configured to introduce the second carbon dioxide rich gas into the first hydrocarbon containing gas, the second hydrocarbon containing gas, the first process stream, the second process stream, the first stream of synthesis gas, the second stream of synthesis gas and / or the synthesis gas product stream14. A method of revamping an existing synthesis gas plant or methanol plant, the existing synthesis gas or methanol plant having a fuel fired reforming unit; the method comprising the steps of:• providing an electrical reformer having an outlet;• fluidly connecting the electrical reformer outlet to an inlet of a shift section, the shift section having an outlet;• fluidly connecting the outlet of the shift section to an inlet of a carbon dioxide removal section, the carbon dioxide removal section having a first outlet for providing a hydrogen rich gas stream and a second outlet for providing a carbon dioxide rich gas stream;• fluidly connecting the first outlet of the carbon dioxide removal section to the fuel fired reformer unit of the synthesis gas plant.

15. The method according to claim 14, further comprising the step of fluidly connecting the second outlet of the carbon dioxide removal section to an outlet of the fuel fired reforming unit, thereby combining the carbon dioxide rich gas stream with the first synthesis gas stream from the fuel fired reforming unit.REF. NO: [02965-WO ]2216. The method according to claim 14 or 15 further comprising the step of fluidly connecting the outlet of the electrical reforming unit to the outlet of the fuel fired reforming unit, thereby combining the first synthesis gas stream from the fuel fired reforming unit with the second synthesis gas stream from the electric reforming unit.

17. A control system for controlling the system according to claim 9 to 13, the control system comprising a controller being in communication with a plurality of valves in the synthesis gas plant and being operable to receive an input signal indicative of renewable power availability and an input signal indicative of desired synthesis gas product stream concentration and being configured to control the plurality of valves based on the input signals.

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