The central focus of the project was to produce tangible improvements and optimise the most promising conventional and innovative deposited catalysts. To this end, the new (CuZnAl(Zr)/HZSM-5) formulations of the catalysts have been printed and assembled as multi-channel arrays into modular, prototype demonstration units.
A great amount of work has been done within the project to develop and test novel catalyst design and single and multi-channel reactors to proof the concept of “structured catalytic reactors”. Thanks to its design by 3D printing, structured catalysts as well as multi-channel reactors improve the mass and heat transfer of the processes. Selective Laser Melting (SLM), a 3D printing technique, was used to build a TRL4 prototype reactor in stainless steel. This technique allowed for the scale-up of 16 (TRL4) to 177 (TRL6) channels in a single piece with the designed dimensions. The TRL4 reactor's 16 channels were firstly manufactured for preliminary testing. To verify the yield of the reaction, tests were performed with different reactor loading of the catalytic material as well as printed catalyst structures.
The reactor characteristics that fulfil the reaction process are as follows:
• Optimisation of heat dissipation: The combination of the tube wall thickness and mechanical and chemical resistance is the key to ensure proper heat transfer within it.
• Dimensional uniformity of the tubes: the dimensions of all the tubes, especially in diameter, should present homogeneity.
• Thermal and mechanical stability: The channels must be free of tensions, which allow withstanding the conditions of temperature and pressure required for the reaction.
• Ease of handling: The loading and unloading of catalyst is made simple.
The multitubular reactor allows a high degree of flexibility for the target production capacity with the flexible number of channels, their lengths and their inner diameters as well as the size and activity of catalysts. The final result was the scaled up manufacturing of the TRL6 multi-tubular reactor, able to treat from 4 to 5 Nm3/h of gas under CO2 hydrogenation conditions (30 bar and 250 °C).
The newly designed CO2Fokus SOEC stack for H2 production has achieved constant 2000 hrs of operation under set (KPIs) conditions with Air flow of 180Nl/min and Current density 0.65 A/cm2.
