Abstract

Flexible, system-oriented operating strategies are becoming increasingly important in terms of achieving a climate-neutral energy system transformation. Solid-oxide electrolysis (SOEC) can play an important role in the production of green synthesis gas from renewable energy in the future. Therefore, it is important to investigate the extent to which SOEC can be used flexibly and which feedback effects and constraints must be taken into account. In this study, we derived a specific load profile from an energy turnaround scenario that supports the energy system. SOEC short-stacks were operated and we investigated the impact that the load profile has on electrical stack performance and stack degradation as well as the product gas composition by means of Fourier-transform infrared spectroscopy. The stacks could follow the grid-related requirement profiles of secondary control power and minute reserves very well with transition times of less than two minutes per 25% of relative power. Only short-term disturbances of the H2/CO ratio were observed during transitions due to the adjustment of feed gases. No elevated degradation effects resulting from flexible operation were apparent over 1300 h, although other causes of degradation were present.

Highlights

  • The conversion of electrical energy from renewable sources into certain chemicals, commonly known as Power-to-X (P2X), is conceived as an important building block for de-fossilizing the chemical industry and to increase the flexibility of the electrical grid

  • In the case of co-electrolysis, water and carbon dioxide are simultaneously reduced in a high-temperature solid-oxide electrolysis cell (SOEC) to yield a mixture of hydrogen and carbon monoxide, known as synthesis gas

  • This paper describes the development of a requirement profile for a degradation test with a flexible operation style for an SOEC stack in laboratory applications

Read more

Summary

Introduction

The conversion of electrical energy from renewable sources into certain chemicals, commonly known as Power-to-X (P2X), is conceived as an important building block for de-fossilizing the chemical industry and to increase the flexibility of the electrical grid. Due to its high efficiency and development potential, it could even be a competitive alternative to current electrolysis technologies (i.e., alkaline- and polymer membrane-based systems) in the future and play an important role in building a GHG-neutral economy [1]. This applies to high-temperature coelectrolysis (HTCoEL), which is under consideration here for the integrated production of synthesis gas with different stoichiometries. In the case of co-electrolysis, water and carbon dioxide are simultaneously reduced in a high-temperature solid-oxide electrolysis cell (SOEC) to yield a mixture of hydrogen and carbon monoxide, known as synthesis gas (syngas). Oxygen anions described in Equation (1) or (2) migrate through the electrolyte to the air side (anode), where they are oxidized and yield oxygen

Methods
Results
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call