Within the CLARA project, the underlying technologies, i.e. biomass pre-treatment, chemical looping gasification, and gas cleaning, were developed towards market maturity, using different experimental setups (see Fig. 2). Subsequently, all technologies were validated in the 1 MWth scale (see Fig. 4), where industrially relevant conditions prevail, thereby elevating their technological readiness level.
Using the dataset generated in 1 MWth pilot scale, the entire biomass-to-liquid (BtL) process chain (see Fig. 3) was simulated in industrial scale, building on the models validated by small pilot data, showing that target KPIs can be met. Furthermore, in-depth simulations of the 200 MWth chemical looping gasifier were performed, using the CLG models developed using pilot data, in order to present avenues of further process optimization.
In terms of final product upgrading, FT products produced under relevant conditions were hydrotreated under different conditions to evaluate optimal operating conditions. Subsequently, the final products were analyzed, showing that the final products from the BtL chain are suitable for the application as drop-in fuels, yet need to be upgraded in a refinery to fulfill drop-in quality.
Another aspect covered in the project is the technological and economical risk assessment of the entire BtL chain. During technical risk assessment, no “show stoppers” were found and mitigation options were defined for every determined risk. For the economic risk assessment, different commercialization options were evaluated. Here, it was found that the economic risks can be minimized by marketing carbon credits via CCS as well as surplus heat e.g. via district heating, apart from FT-product sales. In terms of feedstock selection, wheat straw was found to slightly outperform forestry residues due to the lower procurement price.
Within the scope of the techno-economic analysis carried out within the project, the entire BtL concept was evaluated using the net present value concept. In doing so, a brake even selling price (BESP) of the raw FT-crude of 816 €/t and 781 €/t was calculated, for pine forest residue and wheat straw pellets, respectively. Moreover, it was found that the BESP can be decreased further if waste heat can be marketed and if the CO2 is further stored with selling of carbon credits.
Finally, a life cycle analysis of the BtL chain was carried out, showing that CO2 emissions obtained for the production of 1 t of liquid FT crude product are negative in case sustainably grown biomass is used, allowing for negative emissions of 130 million tons per year for a 200 MWth BtL plant.
Overall, the results made with in the CLARA project were disseminated at a total of 32 workshops and conferences. Moreover, in-depth presentation of important results are presented in 20 peer reviewed publications (see Fig. 5). All exploitation efforts for the CLARA are summarized in the final exploitation plan. Results were exploited in the form of a patent, application in other research projects, utilization in theses, process up-scaling, as well as training purposes, amongst others.
