Abstract
To prevent the irreversible effects of global warming, the need for an energy transition is high. Green hydrogen is one of they key carriers that is needed to make this energy transition. Commonly, green hydrogen is produced by the electrolysis of water. The largest technology that is used for water electrolysis, is alkaline electrolysis. VDL, a company in the Netherlands, seeks to contribute to the energy transition by manufacturing alkaline electrolyser stacks that are needed for large scale hydrogen plants. However, there is no clear best design for such an alkaline electrolysis stack.The main objective of this thesis is to identify the optimal configuration of an alkaline water electrolysis stack, judged by the cost of the hydrogen that it produces. Taking both the effect of the operational stack expenses, and the capital stack expenses into consideration. Furthermore, the effect of the decisions in stack design on the cost of compression and pumping in the balance of plant are included.
A method to analyze and minimize the cost of hydrogen for various stack configurations is proposed in this work. The method optimizes the stack parameters: current density, pressure, diameter, and cell shape for a specified combination of component types. By comparing the hydrogen cost of all identified component type combinations, the optimal configuration can be determined, along with its optimal parameters. Subsequently, a sensitivity analysis is carried out to determine how sensitive the optimal configuration is to variation of external parameters.
The results are not disclosed in this summary, due to confidentiality reasons.
This project shows that judging an alkaline water electrolysis stack on the cost of the hydrogen it produces provides a more detailed result compared to the traditional €/kW stack evaluation.
Since it includes the operational expenses, and the change of these expenses under variation of the operational parameters. Green hydrogen cost reduction is mainly enabled by reductions in sustainable electricity cost, and cost reduction of the plant surrounding the stack. The capital stack expenses have a limited impact on hydrogen cost, as they are less than 10% of the overall hydrogen cost.
| Date of Award | 31 Jan 2022 |
|---|---|
| Original language | English |
| Supervisor | L.F.P. (Pascal) Etman (Supervisor 1) |