JP-7856244-B2 - SOEC-SOFC-HBR hybrid system for green ammonia production

Inventors

• リー、タエ ウォン
• チャン、イン ガブ
• リュ、ボ ヒュン
• ウォン、ミュン ジュン

Assignees

• エフシーアイ カンパニー，リミテッド

Dates

Publication Date

20260511

Application Date

20231113

Priority Date

20230517

Claims (5)

1. Solid oxide fuel cells (SOFCs) and A power compensator that adjusts the supplied power to a constant level using a renewable energy source and the solid oxide fuel cell, A solid oxide water electrolytic cell (SOEC) that produces hydrogen using the power supply adjusted by the aforementioned power compensator, A Haber-Bosch reactor that produces ammonia using hydrogen produced by the solid oxide water electrolysis cell and nitrogen provided by the solid oxide fuel cell, SOEC-SOFC-HBR hybrid system for green ammonia production, including [specific component].
2. The aforementioned solid oxide water electrolytic battery is The SOEC-SOFC-HBR hybrid system for green ammonia production according to claim 1, characterized in that it vaporizes feedwater using heat provided from at least one of the Haber-Bosch reactor and the solid oxide fuel cell.
3. The SOEC-SOFC-HBR hybrid system for green ammonia production according to claim 1, characterized in that at least a portion of the oxygen input to the air electrode of the solid oxide fuel cell is supplied from the solid oxide aqueous electrolysis cell.
4. The aforementioned solid oxide fuel cell uses ammonia as a raw material, The SOEC-SOFC-HBR hybrid system for green ammonia production according to claim 1, characterized in that at least a portion of the ammonia produced by the Haber-Bosch reactor is reused as fuel for the solid oxide fuel cell.
5. The SOEC-SOFC-HBR hybrid system for green ammonia production according to any one of claims 1 to 4, further comprising a controller that adjusts the ammonia production rate of the Haber-Bosch reactor by controlling the output of the solid oxide fuel cell.

Description

This invention relates to a SOFC-SOEC-HBR hybrid system for green ammonia production. While fundamentally powering a solid oxide water electrolytic cell (SOEC) with electricity generated from renewable energy sources such as wind and solar power, the intermittency of renewable energy is compensated for by a solid oxide fuel cell (SOFC). The hydrogen produced by the water electrolytic cell (SOEC) and the nitrogen emitted from the fuel cell (SOFC) are input to a Haber-Bosch reactor, and heat is recovered from both the SOFC and the Haber-Bosch reactor, thereby enabling efficient and continuous green ammonia production. Green ammonia is produced by reacting green hydrogen, generated from the electrolysis of water using renewable energy, with nitrogen collected during standby. Because it contains no carbon, its net emissions are close to zero from a life cycle assessment perspective. While "green ammonia" sometimes refers to a synthetic fuel convertible to electrical and thermal energy, recently, its role as an energy carrier for storing and transporting green hydrogen produced by water electrolysis of renewable energy in liquid form has been gaining more attention. In particular, a new industry is emerging that produces ammonia, which is advantageous for storage and transport, without carbon emissions in regions rich in renewable energy. This ammonia is then synthesized via the Haber-Bosch reaction and exported to regions with high energy demand, such as Northeast Asia, North America, and Europe. Hybrid technologies have been proposed for green ammonia production, integrating renewable energy sources such as wind and solar power, water electrolysis cells (SOEC), and Haber-Bosch reactors (HBR). However, conventionally proposed hybrid systems have the following problems: Firstly, because renewable energy sources have intermittent power generation characteristics and therefore their output is not constant, it is difficult to reliably start up water electrolysis cells (SOECs). Therefore, while energy storage systems (ESS) may be added to compensate for the unstable power output of renewable energy, this requires enormous costs. Secondly, while water electrolytic cells (SOECs) vary by type, low-temperature water electrolytic cells require operating temperatures of 20–200°C, while high-temperature water electrolytic cells require operating temperatures of 500–1000°C. Therefore, a separate heat source and heat exchanger are required to operate a water electrolytic cell (SOEC), but if fossil fuels are used to produce the heat, the goal of carbon neutrality will inevitably be lost. Thirdly, producing ammonia in a Haber-Bosch reactor (HBR) requires nitrogen in addition to the hydrogen supplied by the water electrolysis cell (SOEC). Therefore, additional equipment such as an Air Separation Unit (ASU) must be added to supply nitrogen. However, the operation of the Air Separation Unit generates a large amount of nitrous oxide (N2O), which contradicts the goal of producing green ammonia. Fourthly, the operation of a water electrolysis cell (SOEC) also emits oxygen in addition to hydrogen. Utilizing this by-product oxygen requires a sophisticated collection facility, which further increases system construction costs. For reference, Korean Registered Patent No. 10-2186440 (prior art) relates to an electrochemical ammonia synthesis method, disclosing a technology for synthesizing green ammonia by an electrochemical method without using fossil fuels. While the prior art, which produces ammonia using an electrochemical cell in which the oxidation and reduction electrodes are separated by a cationic conductive membrane, may appear environmentally friendly at first glance, it still suffers from the aforementioned problems because it does not clarify the source of the nitrogen supplied to the electrochemical cell for ammonia synthesis or the electricity used to drive the electrochemical cell. Therefore, the sources of nitrogen and power supply may induce carbon emissions. Korean Registered Patent Publication No. 10-2186440 (November 27, 2020) This is a diagram showing the configuration of the SOEC-SOFC-HBR hybrid system according to Embodiment 1 of the present invention.This is a diagram showing the configuration of the SOEC-SOFC-HBR hybrid system according to Embodiment 2 of the present invention.This is a diagram showing the configuration of the SOEC-SOFC-HBR hybrid system according to Embodiment 3 of the present invention.This is a diagram showing the configuration of the SOEC-SOFC-HBR hybrid system according to Embodiment 4 of the present invention. Several embodiments of the present invention will be described in detail below with reference to the drawings. However, this is not intended to limit the present invention to any particular embodiment; rather, all variations, equivalents, and substitutes, including the technical concept of the present invention, should be understood to be within the scope of the invention. In this sp