The project was initiated with an extensive engineering work in order to modify and redesign existing units and build new equipment for the demonstration at Industrial Park Höchst. This work consisted for example RWGS unit preparation, CO2 compressor construction and modifications to the mobile synthesis unit (MOBSU). In parallel of this technical work, the site preparation required an authority permit process. Although the demonstration plant production capacity was relatively small (~0.5 barrel per day of hydrocarbons), the permit process was similar to full large scale chemical plant with environmental and safety audited approvals.
After permissions were granted, the whole demonstration production chain from industrial raw materials (CO2 and H2) via syngas to FT products was demonstrated in the mobile synthesis unit (MOBSU).
For Fischer-Tropsch reaction to take place, CO2 needs to be converted to CO. This research work was conducted by INERATEC. The work consisted of designing and building of two separate generations of RWGS reactors. In addition to the RWGS development, a successful process concept required novel solutions from catalyst and reactor development. During the project, FT catalysts were developed to achieve desired products and utilize enhanced heat transfer properties of the INERATEC microstructure FT reactor. The development work at VTT was based on a conventional cobalt catalyst recipe modified with several different methods. The target in catalyst development was to produce catalyst with high intrinsic activity and selectivity towards heavy hydrocarbons (i.e. α-value). Those qualities were pursued by adding promoters by traditional incipient wetness method and atomic layer deposition. The suitability of the catalyst to the microstructure reactor was verified by lab-scale in a microstructure reactor. According to WP3 findings, a 1 kg catalyst batch was manufactured at VTT and packed to MOBSU FT reactor by INERATEC for the demonstration run at Höchst.
Linked to the catalyst development activities, kinetic experiments and modelling were performed by Polito. The kinetic model was integrated into a process model to study different process concepts and their efficiencies and yields of desired product fractions. As the RWGS step requires heat, whereas the FT reaction is strongly exothermic, heat integration is essential to achieve high efficiencies. The evaluation of the heat integration possibilities and cost effectiveness were studied based on the capacity in Höchst, CO2 input 1000 kg/h.
Techno-economic studies and life cycle assessments were conducted for industrial scale Fisher Tropsch plants that produced both waxes and chemicals. Assessments were prepared for three alternative configurations that were assumed to be located in Industrial Park Höchst and next to a biogas network in the Netherlands. The main findings from the studies highlight that inexpensive and renewable hydrogen is required for the concepts to be both sustainable and economically feasible. Optimisation of the process requires a location in which the main raw materials would be available, access to renewable electricity is secured and facilities for waste water treatment exist. Utilisation of all by-products from the process is important, and improvement in electricity efficiency remains as an important topic for future research. In addition, the prices of the end-products (waxes and chemicals) should be above the current prices of fossil reference products to improve profitability.
There are several alternatives for CCU concepts. However, ICO2CHEM process is one of the most promising concepts to achieve industrial maturity in the near future. The ICO2CHEM project provided an information package regarding CO2 utilization through RWGS and FT concept. This information was released through project dissemination actions, held workshops, and peer-reviewed publications. The knowledge acquired throughout the project gives all consortium parties a foundation to continue CCU concept development in the following jointly funded and commercial projects.
