Steam Ejector Hydrogen Compression in High-Temperature Electrolyser
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High temperature water electrolysis systems face inefficiencies due to significant electrical energy consumption from thermal/hydraulic fluid management and hydrogen compression, particularly from bulky compressors.
Innovation Solution
Incorporating a steam ejector downstream of a heat exchange module in the hydrogen evacuation line to utilize available steam for partial compression of hydrogen, reducing the need for energy-intensive compressors and optimizing the compression chain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If compressors are used to compress hydrogen to usable pressure, then hydrogen can be stored and transported effectively, but electrical energy consumption increases significantly
Solution Approach 1:
The patent replaces the mechanical compression system (compressors) with a thermal compression system (steam ejector). The steam ejector uses the kinetic energy of high-pressure steam to compress hydrogen gas, substituting mechanical work with thermal-energy-driven fluid dynamics. This resolves the contradiction by eliminating the need for electrically-powered mechanical compressors while maintaining hydrogen compression capability.
Solution Approach 2:
The patent changes the operating parameters of the compression process by using high-temperature steam (typically 200-500°C) to drive the compression instead of room-temperature mechanical compression. This parameter change allows the system to achieve compression using thermal energy that would otherwise be waste heat, significantly reducing electrical energy consumption while maintaining effective hydrogen storage pressure.
2Use of energy by moving object
If steam ejector is used for partial compression, then electrical energy consumption decreases, but device complexity increases
Solution Approach 1:
The steam ejector serves multiple functions simultaneously: it compresses hydrogen gas, recovers waste thermal energy from the electrolysis process, and eliminates the need for separate mechanical compression equipment. This multi-functionality reduces overall system complexity despite introducing a new component, as it replaces multiple separate systems (steam recovery + mechanical compression) with a single integrated device.
Solution Approach 2:
The steam ejector utilizes waste steam from the electrolysis process itself to provide the compression function, making the system self-sufficient. The steam that would otherwise be discarded is now used to drive the compression, eliminating the need for external energy inputs and reducing the system's dependency on additional complex control and power systems.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach decreases overall electrical consumption by leveraging steam for hydrogen compression, thereby enhancing the electrical efficiency of the system and reducing energy costs.
Implementation Method 1
a steam ejector arranged downstream of the first heat exchange module on the first hydrogen exhaust line and configured to inject water vapor into the first hydrogen exhaust line
Implementation Method 2
The ejector contributes to the compression of the produced hydrogen, thus reducing the need for compressors to reach the hydrogen storage pressure
Implementation Method 3
a first heat exchange module configured to provide heat exchange between the first steam feed line and the first dihydrogen discharge line
Implementation Method 4
Water electrolysis is an electrolytic reaction that decomposes water into dioxygen and dihydrogen gas with the help of an electric current according to the reaction: H2O ---+ H2 + 1/2 O2
Data Source
Figure 1
AI summary
The invention relates to a system comprising a high-temperature (HT) electrolyzer (1), a first electrolyzer supply line (2) configured to supply the electrolyzer (1) with steam, a first electrolyzer discharge line (4) configured to discharge dihydrogen from the electrolyzer (1), a second electrolyzer discharge line (3) configured to discharge dioxygen from the electrolyzer (1), a first heat exchange module (5) configured to provide heat exchange between the first steam supply line (2) and the first dihydrogen discharge line (4), characterized in that the system comprises a steam ejector (9) arranged downstream of the first heat exchange module (5) on the first dihydrogen discharge line (4) and configured to inject steam into the first dihydrogen discharge line (4).The present invention relates to the field of high-temperature water electrolysis (HTW, EVHT, HTE, or HTSE), including solid oxide electrolysis (SOEC), and to solid oxide fuel cells (SOFC). It is particularly applicable to optimizing the energy consumption of an SOEC electrolyzer system.