Periodic Reporting for period 3 - CLARA (Chemical Looping gAsification foR sustainAble production of biofuels)
Période du rapport: 2022-05-01 au 2023-04-30
Reducing the detrimental impact of the energy intensive heavy freight transport and aviation industry on the environment is a key obstacle that needs overcoming on the way towards a carbon-neutral society. Hence, alternatives for these industry sectors heavily relying on fossil fuels have to be established. Due to their great promise, the production of biofuels has been greatly intensified in recent years. However, the large-scale utilization of food crops for fuel production has also drawn substantial criticism, related to food scarcity and prices. To limit the implications of the food vs. fuel issue, the pursuit of efficient and economic pathways for producing so-called 2nd generation biofuels, derived from biogenic residues, is en vogue.
Gasification is a well-known thermochemical conversion strategy, allowing for the production of a high calorific synthesis gas from virtually any solid carbon-based material, which is why it is considered to be a crucial building block in future 2nd generation biofuel process chains. Within the scope of the project CLARA an efficient process chain for the production of liquid fuels based on chemical looping gasification (CLG) of biogenic residues is being developed. In chemical looping, pure oxygen for feedstock conversion is provided through the cyclic reduction and oxidation of a circulating oxygen carrier material (see Fig.1). Hence, CLG facilitates the efficient conversion of biogenic feedstocks into a high-calorific and N2-free synthesis gas, without relying on a costly air separation unit. Moreover, the CO2 formed during the autothermal gasification process can be captured efficiently, allowing for the production of end-products with negative carbon footprint. The advantages of this novel gasification technology are combined with other innovative technologies related to feedstock pre-treatment, enabling the use of low-grade biogenic residues for gasification, and raw gas cleaning, lowering capital and operational expenditures by 30 % compared to state of the art gas cleaning technologies. Consequently, the suggested process chain, schematically shown in Figure 2, allows for significantly reduced biofuel production costs, so that cost-competitive drop-in fuels (0.7 €/l) can be realized.
Gasification is a well-known thermochemical conversion strategy, allowing for the production of a high calorific synthesis gas from virtually any solid carbon-based material, which is why it is considered to be a crucial building block in future 2nd generation biofuel process chains. Within the scope of the project CLARA an efficient process chain for the production of liquid fuels based on chemical looping gasification (CLG) of biogenic residues is being developed. In chemical looping, pure oxygen for feedstock conversion is provided through the cyclic reduction and oxidation of a circulating oxygen carrier material (see Fig.1). Hence, CLG facilitates the efficient conversion of biogenic feedstocks into a high-calorific and N2-free synthesis gas, without relying on a costly air separation unit. Moreover, the CO2 formed during the autothermal gasification process can be captured efficiently, allowing for the production of end-products with negative carbon footprint. The advantages of this novel gasification technology are combined with other innovative technologies related to feedstock pre-treatment, enabling the use of low-grade biogenic residues for gasification, and raw gas cleaning, lowering capital and operational expenditures by 30 % compared to state of the art gas cleaning technologies. Consequently, the suggested process chain, schematically shown in Figure 2, allows for significantly reduced biofuel production costs, so that cost-competitive drop-in fuels (0.7 €/l) can be realized.
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.
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.
CLG is a relatively new technology, which has not been studied in great detail prior to the start of the CLARA project. Within the project, the consortium was able to elevate this technology towards technical maturity (TRL 6), thus paving the way towards the edification of large-scale highly efficient next generation gasifiers. Moreover, the novel biomass pre-treatment concept, developed within the project, allows for the exploitation of a wider feedstock range for biomass-to-x process chains, thus promoting the efficient utilization of biogenic waste materials and the development of process chains exhibiting a closed carbon cycle. Lastly, the patented gas cleaning technology, which is being developed within the CLARA project, is expected to significantly reduce syngas post-processing cost, which means that a sound alternative to the state-of-the-art Rectisol process, finding application in a range of different process chains, was formulated.
The integration of these technologies, as suggested in the CLARA project, yields a BtL chain allowing for the production of cost-competitive biofuels, signifying a key pillar in the strive towards a carbon-neutral society. Another issue addressed through the process is the necessity of large-scale deployment of BECCS by 2050 in order to reach the 1.5 °C target. The highly concentrated CO2 stream leaving the gasifier as a side product can be sequestered or further utilized, thus signifying negative CO2 emissions at no substantial additional cost, if sustainably grown biomass is used as feedstock. First calculations indicate that the suggested BtL process will be able to capture 44.7-45.4 % of the carbon contained in the biomass feedstock. Moreover, no detrimental effects regarding food availability or food prices will occur, as the feedstock is limited to biogenic residues. In addition, these biogenic waste materials from agriculture or forestry are valorized, thus diverting profits to rural areas.
The integration of these technologies, as suggested in the CLARA project, yields a BtL chain allowing for the production of cost-competitive biofuels, signifying a key pillar in the strive towards a carbon-neutral society. Another issue addressed through the process is the necessity of large-scale deployment of BECCS by 2050 in order to reach the 1.5 °C target. The highly concentrated CO2 stream leaving the gasifier as a side product can be sequestered or further utilized, thus signifying negative CO2 emissions at no substantial additional cost, if sustainably grown biomass is used as feedstock. First calculations indicate that the suggested BtL process will be able to capture 44.7-45.4 % of the carbon contained in the biomass feedstock. Moreover, no detrimental effects regarding food availability or food prices will occur, as the feedstock is limited to biogenic residues. In addition, these biogenic waste materials from agriculture or forestry are valorized, thus diverting profits to rural areas.