To reduce greenhouse gas emissions in the aviation sector, the development of so-called sustainable aviation fuel (SAF) is indispensable. SAF can be produced via different synthesis routes and has identical properties to fossil-based conventional aviation fuel. Based on the results of previous research, a process pathway to produce SAF via a Biomass-to-Liquid (BtL) concept using entrained flow gasification and Fischer-Tropsch synthesis is simulatively investigated. To optimize overall process efficiency, high-temperature coelectrolysis can be integrated into the process chain resulting in a Power-and-Biomass-to-Liquid (PBtL) approach. Co-electrolysis makes it possible to split carbon dioxide as well as water electrochemically in a single apparatus and to produce synthesis gas with the required properties for Fischer-Tropsch synthesis. A detailed 0D Python model of a reversible solid oxide cell (rSOC) was developed at the Chair of Energy Systems to calculate the steady-state fuel cell and electrolysis operation based on a defined input parameter set. The validation using measured and literature data shows that the current density-cell voltage behaviour can be reproduced with an average relative error of less than 5%. Based on the existing BtL process, two concepts for the integration of co-electrolysis are identified and the 0D rSOC model is integrated into the Aspen Plus ® flowsheet simulation. The newly developed process options are compared with alternative PBtL process variants showing that an identical product yield and carbon efficiency is achieved in different configurations and that electrical power demand can be significantly reduced by integrating co-electrolysis.

This paper presents a modular, fully metallic housing concept that enables a fast change of the cell size due to the utilization of a baseplate. Metal instead of alumina oxide is used to reduce the manufacturing costs. Two different variations are presented, one utilizing a gold seal and a second concept based on a flexible metallic frame. The latter is designed to separate the contacting pressure via a pneumatic piston from the sealing pressure applied via metallic screws. For accurate voltage measurements, sense wires are separated from the current collection and are electrically isolated from the metallic housing. Thermocouples are used to measure the temperature distribution inside the anode part of the housing, as close as possible to the cell, as well as the inlet and outlet gas temperatures. The chromium evaporation of the cathode part of the housing is reduced by a protective coating.

Owing to many irreplaceable advances, solid oxide fuel cells (SOFCs) have a promising and competitive potential in the application of green power supply and greenhouse gas reduction. Especially the utilization of biomass-derived syngas shows a high efficiency potential for the overall system. However, carbon deposition at the anode is a major challenge for the practical application. Once carbon deposited at the anode, the degradation of SOFC performance is permanent and irreversible to a certain extent. The carbon deposition is closely associated with the inner temperature distribution and fuel gas composition within the SOFCs, which is determined by complex chemical and electrochemical reactions. In this study, competing kinetic rates for carbon deposition and regasification are analyzed based on CFD methods for typical biomass-derived syngas compositions. Based on this method, reasonable operating conditions and flow field configuration can be recommended, which reduce the kinetic rate of carbon deposition at the SOFC anode. It is also worth mentioning that the specific anode area where carbon deposition occurs firstly will be detected numerically under different fuel gas components, operating temperatures and flow filed configurations. In summary, an effective method is provided to reduce the carbon deposition at the anode and improve the life expectancy of SOFCs, which is meaningful for SOFC design and operation in practical applications.

Current r-SOC research places special emphasis on the integrated approach of traditional numerical methods like CFD and accelerated AI methods. Using experimentally validated numerical models, the complex thermochemistry of auxiliary components containing syngas was evaluated. This method is used to generate data for the successful development and training of AI-based machine-learning models. Analyses shed light on the interactions between process variables in order to improve and prepare SOC-ready fuel, which is crucial for operation success. A recently developed ML model is utilised effectively to forecast and optimise reforming processes with various fuel constellations, including syngas compositions containing oxygen. Consequently, the results contribute to a greater understanding and qualitative benefits of preparing high-quality, pure syngas, improved fuel utilisation advancing sustainable research, and safe, consistent r-SOC operation. Consequently, early availability of valuable information is achieved. In addition, the strategy reduced prohibitive experiments, which contributed to the sustainable utilisation of resources.

Direct internal reforming (DIR) of hydrocarbons like methane can help improve both economics and efficiency of solid oxide fuel cell (SOFC) systems. The endothermic reforming reaction yields chemical energy in form of hydrogen by directly utilizing waste heat from the cells, which is more efficient than other concepts like partial oxidation (POX) of the fuel gas. Furthermore, DIR cools the stack, reducing the need for excess air. The parasitic power consumption of the air blower is reduced, as well as investment costs for blowers and external reformers. However, DIR can potentially damage SOFC stacks due to thermal gradients and resulting stresses. Furthermore, in case of natural gas, usually some degree of external reforming is needed to convert heavy hydrocarbons like ethane, since these would cause carbon depositions on the SOFC anode. In this paper, we present experimental data from the operation of an anode supported short stack from Ningbo SOFCMAN Energy Technology. Natural gas was used as fuel, and the stack was operated under varying degrees of DIR. The reforming level was adjusted using an electrically heated reformer, and monitored with an online gas analysis. Up to 90 % internal reforming has been demonstrated without signs of carbon deposition or cell fracture. Increasing the degree of DIR had a moderate adverse effect on the stack performance. Possible reasons for this behavior are discussed. These results show that operation of stacks from Ningbo SOFCMAN Energy Technology under high degrees of DIR is feasible, while some performance decrease has to be expected.