Raney Ni as a Versatile Catalyst for Biomass Conversion

The utilization of forestry waste resources in the production of polyurethane resins is a promising green alternative to the use of unsustainable resources. Liquefaction of wood-based biomass gives polyols with properties depending on the reagents used. In this article, the liquefaction of forestry wastes, including sawdust, in solvents such as glycerol and polyethylene glycol was investigated. The liquefaction process was carried out at temperatures of 120, 150, and 170 °C. The resulting bio-polyols were analyzed for process efficiency, hydroxyl number, water content, viscosity, and structural features using the Fourier transform infrared spectroscopy (FTIR). The optimum liquefaction temperature was 150 °C and the time of 6 h. Comprehensive analysis of polyol properties shows high biomass conversion and hydroxyl number in the range of 238–815 mg KOH/g. This may indicate that bio-polyols may be used as a potential substitute for petrochemical polyols. During polyurethane synthesis, materials with more than 80 wt% of bio-polyol were obtained. The materials were obtained by a one-step method by hot-pressing for 15 min at 100 °C and a pressure of 5 MPa with an NCO:OH ratio of 1:1 and 1.2:1. Dynamical-mechanical analysis (DMA) showed a high modulus of elasticity in the range of 62–839 MPa which depends on the reaction conditions.

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Novel molecular biological tools for the efficient expression of fungal lytic polysaccharide monooxygenases in Pichia pastoris

Biotechnology for Biofuels ◽

10.1186/s13068-021-01971-5 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Lukas Rieder ◽

Katharina Ebner ◽

Anton Glieder ◽

Morten Sørlie

Keyword(s):

Pichia Pastoris ◽

Biomass Conversion ◽

Single Step ◽

Additional Advantage ◽

Lytic Polysaccharide Monooxygenases ◽

Expression Host ◽

Shake Flask Cultivation ◽

Polysaccharide Monooxygenases ◽

Efficient Expression ◽

High Yields

Abstract Background Lytic polysaccharide monooxygenases (LPMOs) are attracting large attention due their ability to degrade recalcitrant polysaccharides in biomass conversion and to perform powerful redox chemistry. Results We have established a universal Pichia pastoris platform for the expression of fungal LPMOs using state-of-the-art recombination cloning and modern molecular biological tools to achieve high yields from shake-flask cultivation and simple tag-less single-step purification. Yields are very favorable with up to 42 mg per liter medium for four different LPMOs spanning three different families. Moreover, we report for the first time of a yeast-originating signal peptide from the dolichyl-diphosphooligosaccharide-protein glycosyltransferase subunit 1 (OST1) form S. cerevisiae efficiently secreting and successfully processes the N-terminus of LPMOs yielding in fully functional enzymes. Conclusion The work demonstrates that the industrially most relevant expression host P. pastoris can be used to express fungal LPMOs from different families in high yields and inherent purity. The presented protocols are standardized and require little equipment with an additional advantage with short cultivation periods.

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Computational evaluation of microalgae biomass conversion to biodiesel

Biomass Conversion and Biorefinery ◽

10.1007/s13399-021-01314-2 ◽

2021 ◽

Author(s):

Momir Milić ◽

Biljana Petković ◽

Abdellatif Selmi ◽

Dalibor Petković ◽

Kittisak Jermsittiparsert ◽

...

Keyword(s):

Biomass Conversion ◽

Computational Evaluation ◽

Microalgae Biomass

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New Bifunctional Bis(azairidacycle) with Axial Chirality via Double Cyclometalation of 2,2′-Bis(aminomethyl)-1,1′-binaphthyl

Molecules ◽

10.3390/molecules26041165 ◽

2021 ◽

Vol 26 (4) ◽

pp. 1165

Author(s):

Yasuhiro Sato ◽

Yuichi Kawata ◽

Shungo Yasui ◽

Yoshihito Kayaki ◽

Takao Ikariya

Keyword(s):

Hydrogen Transfer ◽

Bond Cleavage ◽

Enantiomeric Excess ◽

Transfer Hydrogenation ◽

Catalyst Precursor ◽

Asymmetric Catalysts ◽

Axially Chiral ◽

Diastereomeric Mixture ◽

Raney Ni ◽

Half Sandwich

As a candidate for bifunctional asymmetric catalysts containing a half-sandwich C–N chelating Ir(III) framework (azairidacycle), a dinuclear Ir complex with an axially chiral linkage is newly designed. An expedient synthesis of chiral 2,2′-bis(aminomethyl)-1,1′-binaphthyl (1) from 1,1-bi-2-naphthol (BINOL) was accomplished by a three-step process involving nickel-catalyzed cyanation and subsequent reduction with Raney-Ni and KBH4. The reaction of (S)-1 with an equimolar amount of [IrCl2Cp*]2 (Cp* = η5–C5(CH3)5) in the presence of sodium acetate in acetonitrile at 80 °C gave a diastereomeric mixture of new dinuclear dichloridodiiridium complexes (5) through the double C–H bond cleavage, as confirmed by 1H NMR spectroscopy. A loss of the central chirality on the Ir centers of 5 was demonstrated by treatment with KOC(CH3)3 to generate the corresponding 16e amidoiridium complex 6. The following hydrogen transfer from 2-propanol to 6 provided diastereomers of hydrido(amine)iridium retaining the bis(azairidacycle) architecture. The dinuclear chlorido(amine)iridium 5 can serve as a catalyst precursor for the asymmetric transfer hydrogenation of acetophenone with a substrate to a catalyst ratio of 200 in the presence of KOC(CH3)3 in 2-propanol, leading to (S)-1-phenylethanol with up to an enantiomeric excess (ee) of 67%.

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Conversion of biomass to biofuels and life cycle assessment: a review

Environmental Chemistry Letters ◽

10.1007/s10311-021-01273-0 ◽

2021 ◽

Author(s):

Ahmed I. Osman ◽

Neha Mehta ◽

Ahmed M. Elgarahy ◽

Amer Al-Hinai ◽

Ala’a H. Al-Muhtaseb ◽

...

Keyword(s):

Life Cycle Assessment ◽

Life Cycle ◽

Energy Demand ◽

Fossil Fuels ◽

Biomass Conversion ◽

Biofuel Production ◽

Process Efficiency ◽

Liquid Fuels ◽

Thermochemical Processes ◽

Lower Temperature

AbstractThe global energy demand is projected to rise by almost 28% by 2040 compared to current levels. Biomass is a promising energy source for producing either solid or liquid fuels. Biofuels are alternatives to fossil fuels to reduce anthropogenic greenhouse gas emissions. Nonetheless, policy decisions for biofuels should be based on evidence that biofuels are produced in a sustainable manner. To this end, life cycle assessment (LCA) provides information on environmental impacts associated with biofuel production chains. Here, we review advances in biomass conversion to biofuels and their environmental impact by life cycle assessment. Processes are gasification, combustion, pyrolysis, enzymatic hydrolysis routes and fermentation. Thermochemical processes are classified into low temperature, below 300 °C, and high temperature, higher than 300 °C, i.e. gasification, combustion and pyrolysis. Pyrolysis is promising because it operates at a relatively lower temperature of up to 500 °C, compared to gasification, which operates at 800–1300 °C. We focus on 1) the drawbacks and advantages of the thermochemical and biochemical conversion routes of biomass into various fuels and the possibility of integrating these routes for better process efficiency; 2) methodological approaches and key findings from 40 LCA studies on biomass to biofuel conversion pathways published from 2019 to 2021; and 3) bibliometric trends and knowledge gaps in biomass conversion into biofuels using thermochemical and biochemical routes. The integration of hydrothermal and biochemical routes is promising for the circular economy.

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