The CONVERGE project developed innovative components to be integrated in a process for the conversion of secondary biomass into methanol for the biodiesel industry:
- Catalytic cracker (CCT) with valuable BTX chemicals removal: a catalyst with high conversion and selectivity for the (hydro)cracking reaction of tar has been selected, for testing in a specifically designed cracking reactor in combination with the BTX-scrubber reactor (AREA). The integrated system was tested at TRL5, for 120 hours in total, using beech wood and olive pomace as feedstocks demonstrating heavy tar conversion between 75 – 95% and the possibility of simplifying the tar cleaning process with the opportunity to capture the light tar compounds for further applications. More than 4.5 liters of bio-BTX were collected by the AREA reactor in 44 hours of operation, showing up to 97% capture efficiency for Benzene and up to 98% for Toluene.
- Sorption Enhanced Reformer (SER): performance of sorbent and catalyst materials has been demonstrated under relevant SER operating conditions. The developed reforming catalyst outperformed commercial solutions in terms of activity and stability, even in case of glycerol waste streams addition. The validated catalyst recipe was successfully upscaled, and the synthesized material showed improved stability compared to the in-house material. These findings demonstrate the potential of enhancing hydrogen yield in the SER to EHC process, making it a promising material for industrial applications. The CONVERGE catalyst shows higher H2 conversion and less deactivation compared to the commercial type, with less carbon deposition and better resistance towards sintering.
- Electrochemical Hydrogen Compressor (EHC): electrocatalyst and membrane selection, gas distribution and geometries design were the most important preliminary developments for this technology. Specific cell plates have been tested, using 50 µm membrane, obtaining the expected consumption performance (12 MJ/kgH2) and stability. Substantial effort has been put in designing and optimizing a strategy for the catalyst clean-up procedure and CO resistance enhancement. The performance has been demonstrated in more than 500 hours of testing, both with low inlet pressure (20-50 mbarg) and high CO content (50 ppm) cases.
- Methanol membrane reactor: membranes have been qualified and validated, using both test-rigs and modules for the single-and multi-tube membrane testing. Multi-tube membrane reactor showed stable performance over 2664 h of testing at TRL 5, achieving stable CO2 conversion and methanol yield beyond equilibrium measured in the conventional packed bed, resulting in CO2 conversion of 30% (about 8% increase).
The experimental activity was supported by the modelling of the overall process to assess the energy, economic and environmental performance through a detailed techno-economic and Life-cycle analysis.
Several alternative layouts have been proposed and evaluated, resulting in an efficiency increase by 7% and costs in the range of 700-800 €/ton for methanol, aligned with other alternative green methanol production routes but requiring further cost reduction to be fully competitive. A LCA on cradle-to-gate basis, considering the CONVERGE process and other upstream and downstream processes investigated two plant layouts and two biomass types, for which the best environmental performance shows the lowest score in six out of a total of nine impact categories. In parallel, an innovative optimization methodology for selecting the most promising and reliable biomass supply chain for the CONVERGE process has been identified and applied to the Scandinavian, Central European, Hanseatic and Mediterranean districts. Five supply chain case scenarios and related business cases have been selected, maximizing flexibility and reducing global environmental impacts. The opportunities to valorize in different common industry sectors the CONVERGE technologies have been explored, identifying and ranking 16 cases. The most promising applications are in steel industry, refinery, gasification and pyrolysis sectors.
