EP-4737391-A1 - HYDROGEN PRODUCTION PROCESS AND PLANT

EP4737391A1EP 4737391 A1EP4737391 A1EP 4737391A1EP-4737391-A1

Abstract

A process and production plant for producing hydrogen. In one example of the process, a reformer reaction unit for generating a reformate including hydrogen is heated using a burner that is fed fuel gas, a high-purity oxygen gas, and recycled flue gas. The burner generates a flue gas that is at least 95% water and carbon dioxide. The flue gas generated in this manner may be optimized for subsequent carbon-dioxide capture processes.

Inventors

KARNIK, ABHIJEET
Lopez, Jorge Alberto Pena
Rowland, Nicole
Canuso, Vito

Assignees

Technip Energies France

Dates

Publication Date: 20260506
Application Date: 20241030

Claims (15)

A process for producing a product gas comprising a hydrogen gas from a hydrocarbon, the process comprising: (a) introducing a hydrocarbon and a steam into a reformer reaction unit to generate a reformate comprising a hydrogen gas; (b) as part of generation of the reformate, providing heat to the reformer reaction unit using a burner in a radiant section of a furnace, the reformer reaction unit including at least a portion located in the radiant section of the furnace, wherein the burner receives for combustion: (i) a fuel gas, (ii) an oxygen gas comprising 95.0 - 99.8 vol% oxygen, and (iii) a recycled flue gas, wherein the oxygen gas is provided in a separate stream to the burner from the fuel gas and the recycled flue gas; (c) wherein the burner generates a flue gas that comprises at least 95 vol% water and carbon in total, wherein a portion of the flue gas is recycled to the burner as the recycled flue gas.
The process of claim 1, wherein the oxygen gas received by the burner for combustion comprises 99.0 - 99.8 vol% oxygen.
The process of claim 2 wherein the flue gas flows from the radiant section of the furnace through a convection section of the furnace.
The process of claim 3 wherein a first portion of the flue gas is collected from or after the convection section and fed back to the burner as the recycled flue gas, and wherein a second portion of the flue gas is collected from or after the convection section and fed to a carbon dioxide capture system in which carbon dioxide of the flue gas is separated from water of the flue gas.
The process of claim 4 wherein the first portion of the flue gas is collected from a flue gas recycle outlet of the convection section, wherein the convection section comprises a plurality of heat transfer coils and the flue gas recycle outlet is located upstream of at least one of the coils; optionally, wherein the flue gas recycle outlet is located upstream of an economizer coil; and/or wherein the second portion of the flue gas is collected from a second outlet that is located downstream of the plurality of heat transfer coils.
The process of claim 4 wherein the first portion of the flue gas is collected from a flue gas recycle outlet of the convection section at a temperature that is at least 50 degrees Celsius higher than a temperature of the second portion of the flue gas collected from a second outlet of the convection section.
The process of claim 4 wherein the burner further receives for combustion a second fuel gas comprising a pressure swing adsorption (PSA) purge gas generated from the reformate; optionally, wherein the flue gas generated by the burner comprises at least 97 vol% water and carbon dioxide in total.
The process of claim 4 wherein, at the carbon dioxide capture system, the second portion of the flue gas is cooled such that at least some of the water of the second portion of the flue gas condenses and is separated from the flue gas to generate a carbon dioxide rich stream.
The process of claim 8 wherein, at the carbon dioxide capture system, the carbon dioxide rich stream is fed to a multi-stage compression unit in which the carbon dioxide rich stream is subjected to a plurality of cycles of compression, cooling, and condensate separation; optionally, wherein, at the carbon dioxide capture system, after multi-stage compression, the carbon dioxide rich stream is fed to a deoxidizer reactor in which oxygen in the carbon dioxide rich stream is reacted with hydrogen gas to generate water; further optionally, wherein, at the carbon dioxide capture system, after the deoxidizer reactor, the carbon dioxide rich stream is fed to a dryer unit comprising a desiccant.
The process of claim 4 further comprising outputting from the carbon dioxide capture system a carbon dioxide product stream, wherein at least 99 % of the carbon dioxide in the second portion of the flue gas is outputted in the carbon dioxide product stream.
The process of claim 4 further comprising outputting from the carbon dioxide capture system a carbon dioxide product stream, wherein at least 95 vol% of the carbon dioxide product stream is carbon dioxide.
The process of claim 1 wherein providing heat to the reformer reaction unit using the burner comprises introducing the fuel gas into the burner through a fuel gas inlet of the burner, introducing the oxygen gas into the burner through an oxygen gas inlet of the burner separate from the fuel gas inlet, and introducing the recycled flue gas into the burner through a flue gas inlet of the burner separate from the oxygen gas inlet and the fuel gas inlet.
A hydrogen production plant reformer system comprising: (a) a reformer reaction unit arranged to receive a hydrocarbon and a steam and to generate a reformate comprising a hydrogen gas; (b) a furnace comprising a radiant section and a convection section, the radiant section comprising a burner arranged to heat the reformer reaction unit, the reformer reaction unit including at least a portion located in the radiant section of the furnace, the burner comprising a fuel gas inlet, an oxygen inlet separate from the fuel gas inlet and configured to receive an oxygen stream comprising at least 95 vol% oxygen , and a recycled flue gas inlet separate from the fuel gas and oxygen inlets; (c)wherein operation of the burner generates a flue gas that flows from the radiant section of the furnace through a convection section of the furnace; optionally, wherein the burner, the fuel gas stream, the oxygen stream, and the recycled flue gas stream are configured such that the flue gas generated by the burner comprises at least 95 vol% water and carbon dioxide in total; optionally, further comprising a carbon dioxide capture system receiving a portion of the flue gas from the reformer system and separating carbon dioxide of the flue gas from water of the flue gas.
The hydrogen production plant of claim 13, further comprising a carbon dioxide capture system arranged to receive a portion of the flue gas from the reformer system, the carbon dioxide capture system comprising a quench tower arranged to receive the portion of the flue gas and output a carbon dioxide rich stream.
A process for producing a product gas comprising a hydrogen gas from a hydrocarbon, the process comprising: (a) introducing a hydrocarbon and a steam into a reformer reaction unit to generate a reformate comprising a hydrogen gas; (b) as part of generation of the reformate, providing heat to the reformer reaction unit using a burner in a radiant section of a furnace, the reformer reaction unit including at least a portion located in the radiant section of the furnace, wherein the burner receives for combustion: (i) a fuel gas, (ii) an oxygen gas comprising 95.0 - 99.8 vol% oxygen, and (iii) a recycled flue gas, wherein the oxygen gas is provided in a separate stream to the burner from the fuel gas and the recycled flue gas; (c) wherein the burner generates a flue gas that comprises at least 95 vol% water and carbon in total, wherein the flue gas flows from the radiant section of the furnace through a convection section of the furnace, wherein a first portion of the flue gas is collected from or after the convection section and fed back to the burner as the recycled flue gas, and wherein a second portion of the flue gas is collected from or after the convection section and fed to a carbon dioxide capture system in which carbon dioxide of the flue gas is separated from water of the flue gas; and (d) outputting from the carbon dioxide capture system a carbon dioxide product stream, wherein at least 99 % of the carbon dioxide in the second portion of the flue gas is outputted in the carbon dioxide product stream, wherein at least 95 vol% of the carbon dioxide product stream is carbon dioxide.

Description

RELATED FIELDS Plants and processes for producing hydrogen from a hydrocarbon and capturing the carbon dioxide produced by such plants and processes. BACKGROUND A common technique used today for producing hydrogen is steam-methane reforming in which high temperature steam is used to produce hydrogen from a hydrocarbon (e.g. a methane source such as natural gas). Methane reacts with steam in the presence of a catalyst to produce hydrogen, carbon monoxide, and small amounts of carbon dioxide. CH4 + H2O (+heat) → CO + 3H2 In a subsequent reaction the produced carbon monoxide may be further reacted with water in the presence of a catalyst to produce more hydrogen and carbon dioxide in a "water-gas shift reaction." CO + H2O → CO2 + H2 The heat of the steam-methane reforming reaction is typically supplied in a furnace containing multiple tubes filled with the catalyst. The combustion heat is transferred from the hot flue gas to the tubes through radiative and convective heat transfer. A significant by-product of steam-methane reforming is carbon dioxide. In addition to being a side product of the stream-methane reforming and water-gas shift reactions, significant quantities of carbon dioxide are produced from combustion of the carbon-based fuel to heat the hydrocarbon and steam in the reformer to the temperatures necessary for the steam-methane reforming reaction to occur. Growing environmental concerns have made it increasingly desirable to minimize the amount of carbon dioxide released into the atmosphere in connection with industrial processes such as hydrogen production processes. Amine-based pre-combustion and post-combustion technologies are known; however, these chemical absorption / adsorption technologies are energy intensive and high cost, and do not result in maximum CO2 capture. There remains room for improvement. SUMMARY One example is a process for producing a product gas (the product gas including or constituting a hydrogen gas) from a hydrocarbon. The process in this example includes introducing a hydrocarbon and a steam into a reformer reaction unit to generate a reformate including or constituting a hydrogen gas. As part of generation of the reformate, heat is provided to the reformer reaction unit using a burner in a radiant section of a furnace, the reformer reaction unit including at least a portion located in the radiant section of the furnace. The burner receives for combustion: (i) a fuel gas, (ii) an oxygen gas of 95.0 - 99.8 vol% oxygen, and (iii) a recycled flue gas. The oxygen gas is provided in a separate stream to the burner from the fuel gas and the recycled flue gas. The burner generates a flue gas of at least 95 vol% water and carbon in total, and a portion of the flue gas is recycled to the burner as the recycled flue gas. In some implementations of this example, the oxygen gas received by the burner for combustion is 99.0 - 99.8 vol% oxygen. In some implementations of this example, the flue gas flows from the radiant section of the furnace through a convection section of the furnace. In some implementations of this example, a first portion of the flue gas is collected from or after the convection section and fed back to the burner as the recycled flue gas, and a second portion of the flue gas is collected from or after the convection section and fed to a carbon dioxide capture system in which carbon dioxide of the flue gas is separated from water of the flue gas. In some implementations of this example, the first portion of the flue gas is collected from a flue gas recycle outlet of the convection section, with the convection section including several heat transfer coils and the flue gas recycle outlet being located upstream of at least one of the coils. In some implementations of this example, the flue gas recycle outlet is located upstream of an economizer coil. In some implementations of this example, the second portion of the flue gas is collected from a second outlet that is located downstream of the plurality of heat transfer coils. In some implementations of this example, the first portion of the flue gas is collected from a flue gas recycle outlet of the convection section at a temperature that is at least 50 degrees Celsius higher than a temperature of the second portion of the flue gas collected from a second outlet of the convection section. In some implementations of this example, the burner further receives for combustion a second fuel gas, which includes a pressure swing adsorption (PSA) purge gas generated from the reformate. In some implementations of this example, the flue gas generated by the burner is at least 97 vol% water and carbon dioxide in total. In some implementations of this example, at the carbon dioxide capture system, the second portion of the flue gas is cooled such that at least some of the water of the second portion of the flue gas condenses and is separated from the flue gas to generate a carbon dioxide rich stream. In some i