Showing papers by "Vitaliy L. Budarin published in 2017"

Efficient Method of Lignin Isolation Using Microwave-Assisted Acidolysis and Characterization of the Residual Lignin

Abstract: Microwave heating is characterized by high efficiency and selectivity in biomass treatment. Due to the high thermal stability and low polarity of lignin, isolation of lignin by high-temperature microwave treatment is a promising subject for investigation. In this paper, microwave treatment is applied to polysaccharide liquefaction and lignin isolation from softwood at 160–210 °C for 10 min with dilute sulfuric acid. Mass balance/element analysis/FTIR/TG/solid-state 13C NMR/Py-GC/MS are applied to investigate the processed residues (residual lignin). At 190 °C processing temperature, the residual lignin is a material rich in aromatics. High lignin purity (93 wt %) and yield (82 wt %) could be achieved by a simple protocol, which usually takes days or even weeks using conventional milled wood lignin protocols. The Py-GC/MS is applied to check the structure of lignin by a newly developed approach. The liquid phase after isolation is analyzed by GC-MS and liquid carbon NMR. Most chemicals in processed liquid ...

Fast microwave-assisted acidolysis: a new biorefinery approach for the zero-waste utilisation of lignocellulosic biomass to produce high quality lignin and fermentable saccharides

Abstract: Generally, biorefineries convert lignocellulosic biomass into a range of biofuels and further value added chemicals. However, conventional biorefinery processes focus mainly on the cellulose and hemicellulose fractions and therefore produce only low quality lignin, which is commonly burnt to provide process heat. To make full use of the biomass, more attention needs to be focused on novel separation techniques, where high quality lignin can be isolated that is suitable for further valorisation into aromatic chemicals and fuel components. In this paper, three types of lignocellulosic biomass (softwood, hardwood and herbaceous biomass) were processed by microwave-assisted acidolysis to produce high quality lignin. The lignin from the softwood was isolated largely intact in the solid residue after acidolysis. For example, a 10 min microwave-assisted acidolysis treatment produced lignin with a purity of 93% and in a yield of 82%, which is superior to other conventional separation methods reported. Furthermore, py-GC/MS analysis proved that the isolated lignin retained the original structure of native lignin in the feedstock without severe chemical modification. This is a large advantage, and the purified lignin is suitable for further chemical processing. To assess the suitability of this methodology as part of a biorefinery system, the aqueous phase, produced after acidolysis of the softwood, was characterised and assessed for its suitability for fermentation. The broth contained some mono- and di-saccharides but mainly contained organic acids, oligosaccharides and furans. While this is unsuitable for S. cerevisiae and other common ethanol producing yeasts, two oleaginous yeasts with known inhibitor tolerances were selected: Cryptococcus curvatus and Metschnikowia pulcherrima. Both yeasts could grow on the broth, and demonstrated suitable catabolism of the oligosaccharides and inhibitors over 7 days. In addition, both yeasts were shown to be able to produce an oil with a similar composition to that of palm oil. This preliminary work demonstrates new protocols of microwave-assisted acidolysis and therefore offers an effective approach to produce high purity lignin and fermentable chemicals, which is a key step towards developing a zero-waste lignocellulosic biorefinery.

Subtle Microwave-Induced Overheating Effects in an Industrial Demethylation Reaction and Their Direct Use in the Development of an Innovative Microwave Reactor.

Abstract: A systematic study of the conventional and microwave (MW) kinetics of an industrially relevant demethylation reaction is presented. In using industrially relevant reaction conditions the dominant influence of the solvent on the MW energy dissipation is avoided. Below the boiling point, the effect of MWs on the activation energy Ea and k0 is found nonexistent. Interestingly, under reflux conditions, the microwave-heated (MWH) reaction displays very pronounced zero-order kinetics, displaying a much higher reaction rate than observed for the conventionally thermal-heated (CTH) reaction. This is related to a different gas product (methyl bromide, MeBr) removal mechanism, changing from classic nucleation into gaseous bubbles to a facilitated removal through escaping gases/vapors. Additionally, the use of MWs compensates better for the strong heat losses in this reaction, associated with the boiling of HBr/water and the loss of MeBr, than under CTH. Through modeling, MWH was shown to occur inhomogeneously aroun...

Polysaccharide-derived mesoporous materials (Starbon®) for sustainable separation of complex mixtures.

Abstract: The recovery and separation of high value and low volume extractives are a considerable challenge for the commercial realisation of zero-waste biorefineries. Using solid-phase extractions (SPE) based on sustainable sorbents is a promising method to enable efficient, green and selective separation of these complex extractive mixtures. Mesoporous carbonaceous solids derived from renewable polysaccharides are ideal stationary phases due to their tuneable functionality and surface structure. In this study, the structure–separation relationships of thirteen polysaccharide-derived mesoporous materials and two modified types as sorbents for ten naturally-occurring bioactive phenolic compounds were investigated. For the first time, a comprehensive statistical analysis of the key molecular and surface properties influencing the recovery of these species was carried out. The obtained results show the possibility of developing tailored materials for purification, separation or extraction, depending on the molecular composition of the analyte. The wide versatility and application span of these polysaccharide-derived mesoporous materials offer new sustainable and inexpensive alternatives to traditional silica-based stationary phases.

Cyrene and ternary mixtures of cyrene for the enhanced use of dispersion and solvation

Abstract: There is described a nanocomposite material comprising a dispersed phase and a continuous phase wherein the continuous phase comprises Cyrene TM .

Bio-based carbonaceous composite materials from epoxidised linseed oil, bio-derived curing agent and starch with controllable functionality

Abstract: Development of biomass-derived materials using sustainable practices has been one of the major scientific aims over the last few decades. A new class of bio-derived nanocomposite derived from epoxidised linseed oil, a bio-derived crosslinker and a starch based carbonaceous mesoporous material (Starbon®) has been developed. The use of Starbons® technology enables the incorporation of carbonaceous materials with tuneable surface functionality (from hydrophilic to hydrophobic). The resulting composite demonstrated good thermal stability up to 300 °C, good low temperature modulus, flexibility and uniformity, as demonstrated by TGA, DMA and SEM studies, respectively. Furthermore, the thermoset composites' swelling behaviour in solvents with a high polar index through to non-polar ones was investigated, revealing initially that non polar solvents have a greater impact on swelling than polar solvents and that in all cases the addition of filler reduces the extent of swelling. The inclusion of this carbonaceous material with hierarchical pore structure and high BET surface area may further aid the use of such composites in membrane separation applications.

Feedstocks and analysis: general discussion

Abstract: Leigh Aldous, Dimitris Argyropoulos, Vitaliy Budarin, Carlos I. Cabrera-Rodŕıguez, James Clark, Marta Coma, David Constable, Jiajun Fan, Florence Gschwend, Daniel Hayes, Changwei Hu, George Huber, Trevor Hughes, Andrew Hunt, Alexei Lapkin, Gary Lye, Mark Mascal, Avtar Matharu, Xindong Mu, Deepak Pant, Emmanouil Papaioannou, Roberto Rinaldi, Gadi Rothenberg, Joseph Samec, Simo Sarkanen, Andrzej Stankiewicz, Christian Stevens, Magdalena Titirici, Keith Waldron, Kirsty Wilson, Anna Zhenova, Long Zhou and Vânia Zuin