Levoglucosan could be obtained by biomass pyrolysis and chemically transformed to high-added value compounds becoming a promising platform molecule.

Silica immobilized lipases have been prepared and utilized in the valorization of fatty acid-derived food waste streams under continuous flow conditions. Findings demonstrate that better conversions could be obtained when compared with commercially available immobilized enzymes. † Electronic supplementary information (ESI) available. See

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2,5-furandicarboxylic acid (FDCA) is one of the most important bio-sourced building blocks and several routes have been reported for its synthesis. FDCA is presumed to be an ideal green alternative to terephthalate, which is one of the predominant monomers in polymer industry. This Minireview concerns the synthesis of FDCA by using various carboxylation reactions and discusses the synthesis of FDCA starting from furoic acid and CO 2 and using different catalytic and stoichiometric processes. This process is of high interest, as it avoids the glucose isomerization step and selectivity issues observed during the 5-hydroxymethylfurfural oxidation step of the current alternative route to FDCA. Discussion focuses on the main parameters that govern selectivity and activity in the carboxylation processes. Moreover, various previously described processes, such as the Henkel reaction and enzymatic, homogeneous catalytic, and photoelectrocatalytic processes, are also discussed.

Novel bio-nanohybrids based on room temperature one-pot synthesized lipase-nanoparticle systems were developed and characterized in this work, with subsequent investigations on their catalytic activities and stability as compared to the free enzymes. Preliminary results pointed to excelling stabilities, solvent tolerance, and activities as compared to free lipases, opening up further scenarios for their utilization under continuous flow conditions as well as in tandem reactions.

Among several value-added products from glycerol, glyceryl carbonate (GC) has gained prominence during the recent years because of its attractive physicochemical properties and the wide range of industrial applications. As a continuation of our efforts on GC production under environmentally benign conditions, in this work, we have applied a combination of two new biocatalysts containing lipases from porcine pancreas and Candida antarctica immobilized on epoxy resins for GC production via an integrated reaction between triacylglycerol and dimethyl carbonate under both batch and packed-bed reactors. Under continuous flow conditions, the 1:1 (w/w) combination of the home-made immobilized biocatalysts was able to lead to complete conversion of GC with >99% selectivity against 88% demonstrated by the commercial preparation Novozym 435. The new continuous flow biocatalytic system demonstrated a final productivity of 16 × 10 −2 g of GC/h/U of the biocatalyst.

Furfural (FF) is a strategic product for the development of highly valued chemicals from biomass. The oxidation product of FF, furoic acid (FA), is an important precursor for the synthesis of green esters, such as methyl furoate. Taking into account issues with the direct furfural oxidation, furfural derivatives, such as alkyl furoates, can be easily prepared via oxidative esterification.Here, Au nanoparticles that were immobilized on alkaline-earth metal oxide supports were studied for the oxidative esterification of furfural while using alcohol as both reactant and solvent. The formation of esters is favored by the presence of basic sites on catalyst surface, resulting in high selectivity, preventing the formation of the acetal as a by-product. The Au/MgO sample provided up to 95% methyl furoate (MF) yield, a fast reaction rate, and high performance for furfural:Au molar ratios between 50 and 300. Furthermore, this catalyst was stable during reuse, since both the selectivity and the activity were maintained after four cycles. Oxidative esterification products were achieved in the presence of other alcohols, leading to the formation of esters of up to C 5 (isopentyl furoate) with high selectivity (>99%). Linear and branched esters were formed, but the long-chain linear alcohols resulted in higher yields, such as n-butyl furoate in 94% yield.Catalysts 2020, 10, 430 2 of 14 considered to be one of the most important platform compounds in biorefineries of the future [8][9][10]. Several products that are obtained via HMF oxidation are of great interest for the polymer industry because their derivatives can be used as C6 monomers to replace petrochemical monomers [1-10]. For example, 2,5-furandicarboxylic acid (FDCA) is a monomer in the production of polyethylene 2,5-furandicarboxylate (PEF), being a green alternative to polyethylene terephthalate (PET) [11][12][13]. The direct use of FDCA in the industry is difficult due to its low solubility in most commonly used solvents. The furan-2,5-dimethylcarboxylate ester (FDMC) is actually more suitable for the subsequent polymerization reaction, thanks to its better solubility. For this reason, the development of catalytic systems that are capable of producing FDMC directly from the HMF has received much attention today. One alternative is the production of FDCA can be obtained from furoic acid (furfural oxidation product) via the Henkel reaction [13]. However, the use of Au catalysts can also be a viable alternative. FDCA can be obtained from furoic acid (furfural oxidation product) via the Henkel reaction [13]. Recently, Au catalysts have been successfully applied for the oxidative esterification of alcohols [14-17] and they have also been explored for the esterification of furfural and HMF [18][19][20][21][22][23][24][25][26][27][28]. The first example of HMF esterification to produce dimethyl-2-furoate (FDMC) required the use of a base (NaOMe) [29]. Although other catalytic systems have then been reported, there are few examples of successful Au catalytic systems for t...