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WO-2026093112-A1 - PROCESS AND PLANT FOR PRODUCING A SYNTHETIC FUEL

WO2026093112A1WO 2026093112 A1WO2026093112 A1WO 2026093112A1WO-2026093112-A1

Abstract

Disclosed herein is a plant and a process for producing a synthetic fuel, preferably methane and/or methanol. The process includes electrolyzing (S10) water, removing (S20) at least some residual water (21) from a hydrogen product stream (11) from the electrolysis, and reacting (S30) a dried hydrogen product stream (22) and a carbon oxide stream (62), thereby providing a first fuel product stream (31). The method also comprises removing (S40) at least some water (41) from the first fuel product stream (31) and supplying (S50) at least a portion of the residual water (21) removed from the hydrogen product stream (11) and at least a portion of the water (41) removed from the first fuel product stream (31) to the electrolyzer (10) for electrolysis.

Inventors

  • TIETZE, Hannah
  • Pohl, Sebastian
  • SCHOLLENBERGER, Dominik
  • MBADINGA MOUANDA, Gelase

Assignees

  • TURN2X GMBH

Dates

Publication Date
20260507
Application Date
20251023
Priority Date
20241031

Claims (19)

  1. 1 . Process for producing a synthetic fuel, preferably methane and/or methanol, comprising the steps of: a) Electrolyzing (S10) water using an electrolyzer (10), thereby providing a hydrogen product stream (11); b) Removing at least some residual water (21) from the hydrogen product stream (11), thereby providing a dried hydrogen product stream (22); c) Reacting (S30) the dried hydrogen product stream (22) and a carbon oxide stream (62), using a first fuel synthesis reactor (30), thereby providing a first fuel product stream (31) comprising the synthetic fuel; d) Removing (S40), using a second separation unit (40), at least some water (41) from the first fuel product stream (31), thereby providing a dried first fuel product stream (42); and e) Supplying (S50) at least a portion of the residual water (21) removed from the hydrogen product stream (11) and at least a portion of the water (41) removed from the first fuel product stream (31) to the electrolyzer (10) for electrolysis.
  2. 2. Process according to claim 1 , further comprising compressing, using a hydrogen compressor (70) arranged downstream of the electrolyzer (10) and upstream of the first fuel synthesis reactor (30), the hydrogen product stream (11), thereby providing a water condensate stream (72) and a compressed hydrogen product P28903PC00 23 October 2025 35/41 stream (71), wherein the process further comprises supplying at least a portion of the water condensate stream (72) to the electrolyzer (10) for electrolysis.
  3. 3. Process according to claim 2, wherein the portion of the water condensate stream (72) is supplied directly to the electrolyzer (10) for electrolysis.
  4. 4. Process according to any one of the previous claims, wherein step b) comprises removing, using a first separation unit (20), at least a first portion of residual water (21) from the hydrogen product stream (11) respectively from the compressed hydrogen product stream (71), thereby providing the dried hydrogen product stream (22).
  5. 5. Process according to claim 4, wherein step e) comprises: e.1) combining (S51) at least a portion of the water (41) removed from the first fuel product stream and at least the first portion of residual water removed from the hydrogen product stream respectively from the compressed hydrogen product stream, thereby forming a combined water recyclate (52); e.2) degassing (S53), using a degassing unit (53), the combined water recyclate (52), thereby providing a degassed water recyclate (54); e.3) optionally purifying (S55) the degassed water recyclate (54) using a water purification unit (55), thereby providing a purified degassed water recyclate (56); e.4) supplying (S57) the degassed water recyclate (54) provided in step e.2) respectively the purified degassed water recyclate (56) provided in step e.3) to the electrolyzer (10) for electrolysis. P28903PC00 23 October 2025 36/41
  6. 6. Process according to claim 5, wherein step e.2) comprises: e2.1) Heating the combined water recyclate (52) in a heating section of the degassing unit (53), thereby providing a heated combined water recyclate; and e2.2) Expanding the heated combined water recyclate in a gas separator section of the degassing unit (53), preferably in a flash vessel.
  7. 7. Process according to claim 6, wherein in step e2.1) the combined water recyclate (52) is heated to a temperature of at least 60 °C, preferably at least 80 °C.
  8. 8. Process according to claim 6 or 7, wherein in step e2.2) the heated combined water recyclate (52h) is expanded in the gas separator at a pressure lower than 50 barg, preferably lower than 30 barg, more preferably lower than 16 barg.
  9. 9. Process according to any one of the previous claims, further comprising separating (S110), using a fifth separation unit (110), water from a digestate (112) of a biogas fermentation facility (111), post-processing (S120), using a post-pro- cessing unit (120), the water separated from the digestate (113) and supplying (S130) at least a portion of the post-processed separated water (121) to the electrolyzer (10) for electrolysis.
  10. 10. Process according to claim 9, further comprising purifying at least a portion of the post- processed separated water (121) before supplying it to the electrolyzer (10) for electrolysis.
  11. 1 1 . Process according to claim 10 and 5, wherein the post- processed separated water (121) and the degassed water recyclate (54) provided in step e.1) are combined and then purified jointly in the water purification unit (55). P28903PC00 23 October 2025 37/41
  12. 12. Process according to any one of the previous claims, further comprising the step of: f) removing (S60), using a third separation unit (60), at least some residual water (61) from a wet carbon oxide stream (62w), thereby providing a dried carbon oxide stream (62d); supplying (S64) the dried carbon oxide stream (62d) to the first fuel synthesis reactor (30) for producing the synthetic fuel; and supplying (S67) at least a portion of the residual water removed (61) from the wet carbon oxide stream to the electrolyzer (10) for electrolysis.
  13. 13. Process according to claim 12 and 5, wherein step e.1) further comprises combining at least a portion of the residual water (61) removed from the wet carbon oxide stream, at least a portion of the water (41) removed from the first fuel product stream and at least the first portion of residual water removed from the hydrogen product stream respectively from the compressed hydrogen product stream, thereby forming the combined water recyclate (52).
  14. 14. Process according to claim 12 or 13, wherein the wet carbon oxide stream (62w) derives from a/the biogas fermentation facility (111) and/or from a carbon removal facility, such as a direct air capture facility.
  15. 15. Process according to any one of the previous claims, further comprising the steps of: h) Reacting (S80) the dried first fuel product stream (42) in a second fuel synthesis reactor (80), thereby providing a second fuel product stream (81) comprising the synthetic fuel; P28903PC00 23 October 2025 38/41 i) Removing (S90), using a fourth separation unit (90), at least some residual water from the second fuel product stream (91), thereby providing a dried second fuel product stream (92); and j) Optionally recycling (S100) at least a portion of the residual water removed (91) from the second fuel product stream to the electrolyzer (10) for electrolysis in step a).
  16. 16. Process according to any one of the previous claims, wherein the carbon oxide stream (62) comprises carbon dioxide, carbon monoxide or a mixture thereof.
  17. 17. Plant (1) for producing a synthetic fuel, preferably methane and/or methanol, comprising: a. An electrolyzer (10); b. A first separation unit (20) arranged downstream of the electrolyzer (10) and configured for removing at least a first portion of residual water (21) from a hydrogen product stream (11) of the electrolyzer (10), thereby providing a dried hydrogen product stream (22); c. A first fuel synthesis reactor (30) arranged downstream of the first separation unit (20) and configured for reacting the dried hydrogen product stream (22) and a carbon oxide stream (62), thereby providing a first fuel product stream (31) comprising the synthetic fuel; d. A second separation unit (40) arranged downstream of the first fuel synthesis reactor (30) and configured for removing at least some residual water (41) from the first fuel product stream (31); P28903PC00 23 October 2025 39/41 e. A first recycling line (501) fluidically interconnecting the first separation unit (20) and the electrolyzer (10), wherein the first recycling line (501) is configured for supplying to the electrolyzer (10) the first portion of residual water (21) removed from a hydrogen product stream; f. A second recycling line (502) fluidically interconnecting the second separation unit (40) and the electrolyzer (10), wherein the second recycling line (502) is configured for supplying to the electrolyzer (10) at least a portion of the water (41) removed from the first fuel product stream.
  18. 18. Plant (1) according to claim 17, further comprising: a. A combining unit (51) arranged downstream of the first separation unit (20) and downstream of the second separation unit (40), wherein the combining unit (51) is configured for combining at least the first portion of residual water (21) removed from the hydrogen product stream and at least a portion of the water (41) removed from the first fuel product stream, thereby forming a combined water recyclate (52); b. A degassing unit (53) arranged downstream of the combining unit (51) and configured for degassing the combined water recyclate (52), thereby providing a degassed water recyclate (54), wherein the degassing unit (53) is fluidically interconnected with the electrolyzer (10) to supply the degassed water recyclate (54) to the electrolyzer (10) for electrolysis.
  19. 19. Plant (1) according to claim 18, further comprising a water purification unit (55) arranged downstream of the degassing unit (53) and upstream of the electrolyzer P28903PC00 23 October 2025 40/41 (10), wherein the water purification unit (55) is configured for purifying the degassed water recyclate (54), thereby providing a purified degassed water recy- clate (56).

Description

P28903PC00 23 October 2025 1/41 Process and Plant for Producing a Synthetic Fuel FIELD OF THE DISCLOSURE The present disclosure relates to the field of synthetic fuel production, in particular to the production of methane and/or methanol. Disclosed herein are a process for producing a synthetic fuel and a plant for producing synthetic fuel. BACKGROUND OF THE DISCLOSURE Fuels such as methane and/or methanol are important energy sources, including for industrial applications and for private households. Many industries rely on natural gas for different purposes, including heat production. The fuels often derive from natural gas. However, reducing the consumption of natural gas is one of the world population targets to reduce or mitigate the negative impacts of the human made climate change. Therefore, synthetic fuels, in particular methane and/or methanol, are an important component of a modern and sustainable energy ecosystem. Accordingly, there is a need to improve the production of synthetic fuels, in particular with respect to sustainability, environmental impact, energy efficiency and resource efficiency. Many approaches and processes for producing synthetic fuels have been developed so far. For the synthesis of methane in particular, many of them rely on the Sabatier process or related processes. Different energy sources may be used in the processes, including renewable energy sources such as solar, nuclear or wind power plants. The synthesis of methane or other synthetic fuels is a complex procedure which requires a plurality of components and input products. For example, one challenge is that a constant energy supply and product inflow is often required to achieve efficient fuel P28903PC00 23 October 2025 2/41 synthesis. A further challenge is that a complex network of input resources are required, including a stable supply of reactants and an efficient energy management system to control the fuel production. Some of the input resources such as water may be limited, which requires an efficient resource management system. In particular, in regions that are scarce of water, an important water management system may be required to minimize waste of water. At the same time, the need to manage water flows efficiently must be balanced with other process requirements, such as heat management, high fuel production rates and potential scarcity of other input resources. A further reason for the desire to improve water management is the general desire to improve sustainability. Accordingly, there is a need to improve the known processes and plants for producing synthetic fuels such as methane and/or methanol. In particular, there is a need to improve the management of the resources used in the processes and plants, in particular the management of the reactant and product streams. SUMMARY OF THE DISCLOSURE It is an object of the present disclosure to provide a plant and a process for producing synthetic fuel, in particular methane and/or methanol, which address at least some of the disadvantages of the known plants and processes for producing synthetic fuel. It is a particular object to improve the overall management of the process, particularly regarding the management of the resources used in the process, such as the management of reactant streams and product streams. In at least some embodiments, it is an object to improve the autarky with respect to the raw materials used, in particular water. According to the present disclosure, these objects are addressed by the features of the independent claims. Further preferred embodiments follow from the dependent claims, figures and the description. P28903PC00 23 October 2025 3/41 According to a first aspect of the present disclosure, a process for producing a synthetic fuel, preferably methane and/or methanol, is provided. The process comprises the steps of: a) Electrolyzing water using an electrolyzer, thereby providing a hydrogen product stream; b) Removing at least some residual water from the hydrogen product stream, thereby providing a dried hydrogen product stream; c) Reacting the dried hydrogen product stream and a carbon oxide stream, using a first fuel synthesis reactor, thereby providing a first fuel product stream comprising the synthetic fuel; d) Removing, using a second separation unit, at least some water from the first fuel product stream, thereby providing a dried first fuel product stream; and e) Supplying at least a portion of the residual water removed from the hydrogen product stream and at least a portion of the water removed from the first fuel product stream to the electrolyzer for electrolysis. By removing at least some water from the first fuel product stream and from the hydrogen product stream and then supplying it to the electrolyzer for electrolysis, the water autarky of the process is improved. The technical effort required to use both of these residual water sources in the electrolysis is significant and typically exceeds the effort r