Integrated e-Methanol and Drop-in Fuels Hydrothermal Liquefaction Platform-Techno-Economic and GHG Emissions Assessment for Grid-Connected Plants under Flexible BECCU(S) Operation.

This study examines the combined production of drop-in fuels and methanol using hydrothermal liquefaction (HTL) as a technological basis in the context of bioenergy and power-to-X (PtX) applications. Given the increasing need for flexibility in a system dominated by fluctuating renewable power, we evaluated flexible methanol operation as a strategy to harness global greenhouse gas (GHG) emissions in a grid-connected HTL setup. In this operation, the biogenic CO2 destination is alternated between methanol synthesis bioenergy with carbon capture and utilization and combined underground storage depending on the hourly electricity price and grid carbon intensity. The results indicate that the strategy has potential to maintain the average fuel carbon intensity within the 65% GHG reduction threshold set by the renewable energy directive III at a minimum methanol price of 870 EUR/t. This approach could facilitate implementation as it does not require dedicated renewable power generation and hydrogen storage, potentially decreasing costs compared to semi-islands and off-grid PtX systems.

Screening of potential endoglucanases, hydrolysis conditions and different sugarcane straws pretreatments for cello-oligosaccharides production.

Cello-oligosaccharides (COS) are oligomers with 2 to 6 ß-1,4-linked glucose units, with potential applications in the food/feed and bioenergy industrial sectors. In this study, the combination of five heterologous expressed endoglucanases varying the temperature and pH conditions were evaluated by design of experiments for COS production. Afterwards, the best combination was tested to produce COS from different pretreated sugarcane straws: ionic liquid, diluted acid, hydrothermal and steam-explosion. The results showed that steam explosion pretreated sugarcane straw treated with CtCel9R enzyme at 50 °C and pH 5.0 yielded 13.4 mg COS g biomass-1, 5-18-fold higher compared to the other pretreated straws. Under the conditions evaluated, the removal of hemicellulose and decrease in the cellulose crystallinity can benefits the enzymatic hydrolysis. This is the first study that combined the evaluation of different enzymes, conditions, and sugarcane straw pretreatments to optimize COS production in a single step without glucose formation.

The solid-state cultivation of Streptococcus zooepidemicus in polyurethane foam as a strategy for the production of hyaluronic acid.

Hyaluronic acid (HA) is a biopolymer with important applications in the pharmaceutical, medical, and cosmetic fields. This work explores the potentialities of a cylindrical polyurethane foam dowel with central aeration as a novel packed bed bioreactor for the production of HA. The goals were to provide a large surface area for oxygen transfer through the patches of liquid film that form in the pores of the foam in which cell proliferation and HA production occur and to easily recover the HA produced. The resulting yields of HA/cell were higher than 1, and the produced HA was completely recovered by pressing the foam. The external conditions that inhibit catabolism, the deviation of energetic metabolism toward the production of HA, were modulated by aeration and the initial glucose concentration. The production of HA was reproducible in 12 successive fermentation cycles. These findings contribute to the development of efficient strategies for the controlled production and recovery of HA.