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There is an environmental concern regarding the use of petroleum-based lubricants, which are generally toxic and nonbiodegradable. Biobased lubricants, such as vegetable oils, are the alternative: they show excellent lubricity, are readily biodegradable and nontoxic. However, a major disadvantage of using vegetable oils in lubricant applications is their lack of thermo-oxidative stability, which can be improved by antioxidant additives. Here, we propose the use of lignin-based additives in biolubricant formulations to improve this feature, based on lignin’s known antioxidant properties. To ensure a stable dispersion in vegetable oil, lignin was partially esterified. Antioxidant properties of lignin before and after palmitoylation were demonstrated in a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Four different lignin-based fractions, commercial Protobind P1000 soda lignin from straw, solvolytically fractionated Protobind P1000 lignin and two lignin fractions from reductively catalyzed fractionation (RCF) of native birch wood, were tested in biolubricant formulations with castor oil as base oil. Those lignin fractions exhibited excellent performance compared to butylated hydroxytoluene (BHT), a commonly used petroleum-based antioxidant. Formulations of modified lignin in castor oil possess improved thermo-oxidative stability, as illustrated by their increased oxidation induction time. Additionally, rheological and tribological tests demonstrate similar, or in some cases improved, lubricating properties compared to castor oil. This study showcases the successful incorporation of lignin-based antioxidants in biolubricant formulations, tackling the major disadvantage of vegetable oils as environment-friendly lubricants.

The synthesis of novel, renewable lignin-based protective films with anticorrosive properties is presented in this work. Thermosetting films are prepared by means of tandem UV-initiated thiol-yne "click" synthesis and Claisen rearrangement strategy. These films contain high lignin loading, 46-61%, originating from a nickel-catalyzed birch wood reductive catalytic fractionation (RCF) process. Lignin fractions with varying monomer content are compared before resins preparation, namely a mixture of monomers and oligomers without fractionation, or after fractionation via extraction and membrane separation. This study aims to determine if the separation of lignin monomers and oligomers is necessary for the application as a thermosetting resin. The resulting films exhibit remarkable adhesion to a metal surface and excellent solvent resistance, even after exposure to a corrosive environment. Moreover, those films show superior barrier properties, studied with odd random phase electrochemical impedance spectroscopy (ORP EIS). After 21 days of exposure, the examined films still show impressive high corrosion protection with the low-frequency impedance approximate to 10(10) omega cm(2) and capacitive behavior. This work demonstrates an interesting proof-of-concept where laborious, costly, and energy-intensive separation of the depolymerized lignin mixture of monomers and oligomers is not necessary for the successful resin synthesis with excellent properties using the applied synthetic strategy.

Every twig and splinter used Plant-based production of commodity chemicals faces steep competition from fossil resources, which are often cheaper and easier to partition. Sustainable use of renewable resources requires strategies for converting complex and recalcitrant biomolecules into streams of chemicals with extraordinary efficiency. Liao et al. developed a biorefinery concept in which wood is eventually fully converted into useful chemicals: phenol, propylene, pulp amenable to ethanol production, and phenolic oligomers that can be incorporated into ink production (see the Perspective by Zhang). A life-cycle assessment and techno-economic analysis highlight the efficiency of the process and reveal the potential for such biorefinery strategies to contribute to sustainable chemicals markets. Science , this issue p. 1385 ; see also p. 1305

© 2018, The Author(s), under exclusive licence to Springer Nature Limited. There is an urgent need to address environmental problems caused by our transportation systems, which include the reduction of associated CO2 emissions. In the short term, renewable drop-in fuels are ideal, as they allow a direct integration into the existing infrastructure. However, preferably they would perform better than current alternatives (for example, bioethanol) and be synthesized in a more efficient way. Here we demonstrate the production of biogasoline with a direct upstream integration into processes in existing petrorefinery facilities that targets the 10% bio-based carbon in accordance with the current European Union directives (for 2020) for biofuels. To achieve this goal, we show the valorization of (hemi)cellulose pulp into light naphtha using a two-phase (H2O:organic) catalytic slurry process. A C5–C6 alkane stream, enriched with bio-derived carbon and compatible with further downstream petrorefinery operations for (bio)gasoline production, is automatically obtained by utilizing fossil light straight run naphtha as the organic phase. The ease of integration pleads for a joint petro/bio effort to gradually produce bio-enriched gasolines, wherein the chemical compounds of the bio-derived fraction are indistinguishable from those in current high-quality gasoline compositions. ispartof: Nature Energy vol:3 issue:11 pages:969-977 status: published

Efficient transformation of biomass to value-added chemicals and high-energy density fuels is pivotal for a more sustainable economy and carbon-neutral society. In this framework, developing potential cascade chemical processes using functionalised heterogeneous catalysts is essential because of their versatile roles towards viable biomass valorisation. Advances in materials science and catalysis have provided several innovative strategies for the design of new appealing catalytic materials with well-defined structures and special characteristics. Promising catalytic materials that have paved the way for exciting scientific breakthroughs in biomass upgrading are carbon materials, metal-organic frameworks, solid phase ionic liquids, and magnetic iron oxides. These fascinating catalysts offer unique possibilities to accommodate adequate amounts of acid-base and redox functional species, hence enabling various biomass conversion reactions in a one-pot way. This review therefore aims to provide a comprehensive account of the most significant advances in the development of functionalised heterogeneous catalysts for efficient biomass upgrading. In addition, this review highlights important progress ensued in tailoring the immobilisation of desirable functional groups on particular sites of the above-listed materials, while critically discussing the role of consequent properties on cascade reactions as well as on other vital processes within the bio-refinery. Current challenges and future opportunities towards a rational design of novel functionalised heterogeneous catalysts for sustainable biomass valorisation are also emphasized. ispartof: Chemical Society Reviews vol:47 issue:22 pages:8349-8402 ispartof: location:England status: published

In the last 5 years, reductive catalytic fractionation of lignocellulose biomass has emerged as a promising biorefinery concept that combines biomass fractionation with the preservation of chemical functionality in its products. Although significant efforts have been made in optimizing this technology on lab scale, the implementation on a larger (pilot) scale is still in its infancy. In our own search for the scale-up potential of this technology, we faced several fundamental and technical research questions that, to this day, remain unanswered. These fundamental questions are related to four main aspects of RCF, the lignocellulose feedstock, the operating pressure, the redox catalyst, and the solvent. In order to inspire future multidisciplinary research in the RCF community, these scale-up challenges are presented and discussed via multiple angles combining chemical process hurdles with more technical aspects, such as reactor design and process consequences.

Lignin is the main cause of lignocellulosic biomass recalcitrance to industrial enzymatic hydrolysis. By partially replacing the traditional lignin monomers by alternative ones, lignin extractability can be enhanced. To design a lignin that is easier to degrade under alkaline conditions, curcumin (diferuloylmethane) was produced in the model plant Arabidopsis thaliana via simultaneous expression of the turmeric (Curcuma longa) genes DIKETIDE-CoA SYNTHASE (DCS) and CURCUMIN SYNTHASE 2 (CURS2). The transgenic plants produced a plethora of curcumin- and phenylpentanoid-derived compounds with no negative impact on growth. Catalytic hydrogenolysis gave evidence that both curcumin and phenylpentanoids were incorporated into the lignifying cell wall, thereby significantly increasing saccharification efficiency after alkaline pretreatment of the transgenic lines by 14–24% as compared with the wild type. These results demonstrate that non-native monomers can be synthesized and incorporated into the lignin polymer in plants to enhance their biomass processing efficiency. A study introduces curcumin biosynthesis in Arabidopsis by expressing the turmeric genes DIKETIDE-CoA SYNTHASE and CURCUMIN SYNTHASE 2, and the monomers curcumin and phenylpentanoids were successfully incorporated into the lignin cell wall to enhance biomass processing.

Comprehensive HT-GC × GC FID/MS enables reliable detection and quantification of RCF lignin monomers, dimers and, trimers.