Periodic Reporting for period 2 - BioSFerA (BIOfuels production from Syngas FERmentation for Aviation and maritime use)
Reporting period: 2021-10-01 to 2022-09-30
The extensive use of petroleum-derived jet fuels has resulted in a remarkable decline in petroleum reserves and the generation of notable amounts of greenhouse gases (GHG) making the airline sector responsible for 3% of the total GHG emissions. GHG emissions from international shipping in 2012 accounted for 2.2% of total anthropogenic CO2 emissions. The Paris Agreement’s objectives put aviation and shipping sectors under great pressure and environmental inspection. Biofuels have recently attracted great interest and have been identified as a promising strategy to reduce CO2 emissions in the aviation and shipping sector. Issues like food vs fuel and costly feedstock and uncertainty over cost reduction related to the currently produced biofuels, impose the incorporation of alternate approaches in the current biofuels production pathways that target to more competitive drop-in biofuels. The BioSFerA concept refers to a combined thermochemical-biochemical Biomass-to-Liquid (BtL) pathway for the production of aviation and maritime liquid fuels. It will exploit a wide range of non-food bio-based feedstock to produce drop-in biofuels with a competitive minimum selling price <0.7-0.8 €/l and a >40% GHG emissions reduction. The latter along with the fact that feedstock availability is high across all EU countries make BioSFerA an environmentally and socially sustainable solution. BioSFerA develops and validates a novel biorefinery concept based on a 2-step biological gas-to-liquid process using syngas from a Dual Fluidized Bed Gasifier (DFBG) targeting at the production of hydrotreated triacylglycerides (HTAGs) for next generation aviation and marine biofuels. Two main objectives are the development and optimization of a flexible gasification process and the determination of the optimum conditions of the fermentation process at pilot level. Additionally, genetic engineered bacteria and yeast are to be constructed for the efficient acetate production from syngas and lipids from acetate, respectively, and the produced HTAGs are to be tested regarding their compatibility with aviation and marine standards for drop-in fuels. The BtL value chain is to be scaled up to industrial size using advanced models. Moreover, business plans around Europe are to be built-up aiming at the development of cost-effective and versatile value chains with profitable investments. Finally, the impact of the proposed biorefinery on the environment and society will be also evaluated.
A preliminary definition of the full value chain of the BioSFerA concept was accomplished during the first period of the project with the identification of the stakeholders’ community, the KPIs definition, the feedstock selection, the replicability assessment in selected European countries and the development of a preliminary process model. Lab scale gasification and fermentation tests revealed that the reformer is able to remove most of the syngas contaminants thus allowing the successful growth of acetogenic bacteria. Gas fermentation trials with Moorella thermoacetica wild-type strain in pressurized bioreactors have achieved an acetate production of above 30 g/L reaching the project’s target. Efforts to increase the acetate productivity are underway. As for the acetate fermentation, experiments with Yarrowia lipolytica modified strain have shown a clear increase in TAG accumulation compared with the wild-type strain. Optimization trials have resulted in increased lipid titer and low by-product formation. Genetic engineering efforts for the construction of recombinant strains to further improve acetate and TAGs production are still in progress. In addition, several techniques for TAGs recovery and purification, including the innovative steam explosion method, are being evaluated. A modular pilot unit for syngas-to-acetate conversion has been built and the preparatory activities for its integration to the synthesis gas plant in Finland are almost complete. The piloting runs, that will validate syngas fermentation at TRL5, are scheduled for April 2023. Furthermore, a Computational Fluid Dynamics (CFD) simulation is being developed to investigate the hydrodynamics of an industrial DFB gasifier, as well as a process model for the commercial BioSFerA replication using data from the lab/pilot tests, as well as the literature. The assessment of the BioSFerA concept from an environmental, economic and social point of view is also being performed. A communication and dissemination strategy has also been applied to increase the project visibility. A website, social media profiles, as well as a newsletter, have been constructed and brochures and roll-up banners have been created. Publications, results and news on the BioSFerA channels have raised public awareness about the project.
Within BioSFerA project, it will be the first time that a DFBG will be connected to a novel 2-step fermentation unit to perform pilot tests for microbial oil production. In addition, since the fermentation process is less sensitive to contaminants compared with the common chemical synthesis units, a simplified gas cleaning technology with limited syngas treatment will be designed reducing, thus, the investment and operation costs. Metabolic engineering tools will be developed to improve the performance of the microbes and minimize the undesired by-products. Lipid extraction will be another challenge as steam explosion will be implemented for the first time for the disruption of the oleaginous yeast cell walls. Finally, the hydrotreatment of this type of microbial oil using renewable H2 has never been studied before. The production of large volumes of lipids will offer the opportunity to validate the process at pilot scale. Thanks to the efficient operation of the DFBG technology and the ability of engineered strains to produce the desired intermediate products with extremely high selectivity, the BioSFerA concept will result in increased final product yields and high energy efficiency. Moreover, the final biofuels cost is expected to be low due to the avoidance of significant capital costs like extensive syngas cleaning units, the use of cheap feedstock, the reduced transportation costs and the limited biomass pretreatment needs. As concerns the environmental performance, CO2 emissions are expected to be really low or even negative in the case of exploiting the CO2 stream produced during fermentation. Additionally, BioSFerA requires 22-34% less land for the production of initial biomass feedstock compared with other renewable fuel technologies. Regarding the societal expected impacts, BioSFerA will provide aviation and shipping companies with sustainable clean biofuels to meet the respective emission reduction targets resulting, thus, in public health improvement. The development of the concept at industrial level and its market uptake will offer new jobs and opportunities for many people. The expected efficient and effective way of producing liquid biofuels suggested within BioSFerA will boost EU leadership in the area of renewable fuels for aviation and shipping ensuring EU competitiveness within the demanding framework of Paris Agreement.