Hydrothermal Conversion of Biomass into Fuel and Fine Chemicals

Catalytic hydrothermal liquefaction of Scenedesmus sp. biomass integrated with dark-fermentation: biocrude and low-carbon fuel production in a biorefinery approach

“…Carboxylic acids could no longer participate in these reactions because they are neutralized in the aqueous phase as soluble carboxylates. 22…”

“…The presence of H 2 also promotes the hydrogenation of unsaturated materials, reducing polymerization and aromatization and thus improving bio-oil product quality. 22,30 Some cyclic nitrogenous compounds (2-pyrrolidone, hexadecanamide, oleamide, piperidine, indole, 2-methyl-6-(5-methyl-2-thiazolin-2-yl amino), 7,8-didehydro-4 pyridine, etc. ) are most likely yielded via Maillard reactions between amino acids and easily degradable carbohydrates (reducing sugars), which are produced by hydrolysis of protein and carbohydrate in trace amounts, respectively, and thus ignored.…”

“…24 Additionally, methods that may improve the stability of the catalyst include introducing a secondary metal (to adjust the crystal plane structure), modifying the catalyst (a core–shell structure), and reducing poisonous substances. 7,22…”

“…14,19 The amino acids in HTL follow two reaction pathways, deamination to yield organic acids and ammonia and/or decarboxylation to generate amines and carbon dioxide, 20,21 whereas fatty acids at elevated temperatures undergo decarboxylation to yield ketones, alkanes, and alkenes and triglycerides polymerize to form high-molecular-weight structures. 7,22,23 Catalysts also plays a significant role in the product selectivity of HTL by favouring bio-oil production rather than char formation. 7,11,15 Homogeneous catalysts (MgSO 4 , MnCl 2 , K 2 CO 3 , NaOH, KOH, etc. )…”

Advancements, Challenges, and Pathways to Sustainable Biofuel Production

“…Torrefaction is a thermal action process used to improve the vitality and quality of solid biomass, or prepare the biomass, under a passive environment for upgrading the energy aspect or its pretreatment for pyrolysis, liquefaction, combustion, and gasification 6. Biomass pyrolysis is ordinarily carried out at temperatures between 350 –750 °C, yielding bio‐oil, charcoal, and biogas 7.…”