Browsing by Author "Tarasov, Dmitry"
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Item Advanced NMR Characterization of Aquasolv Omni (AqSO) Biorefinery Lignins/Lignin-Carbohydrate Complexes(Wiley-VCH Verlag, 2023-09-22) Schlee, Philipp; Tarasov, Dmitry; Rigo, Davide; Balakshin, Mikhail; Department of Bioproducts and Biosystems; Lignin Chemistry; Bioproduct ChemistryOur recently reported AquaSolv Omni (AqSO) process shows great potential as a parameter-controlled type of biorefinery, which allows tuning of structure and properties of the products towards their optimal use in high-value applications. Herein, a comprehensive NMR (quantitative 13C, 31P, and 2D heteronuclear single-quantum coherence) structural characterization of AqSO lignins is reported. The effect of the process severity (P-factor) and liquid-to-solid ratio (L/S) on the structure of the extracted lignins has been investigated and discussed. Low severity (P-factor in the range 400–600) and L/S=1 led to the isolation of less degraded lignin with a higher β-O-4 content up to 34/100 Ar. Harsher processing conditions (P-factor=1000–2500) yielded more condensed lignins with a high degree of condensation up to 66 at P-factor=2000. New types of lignin moieties, such as alkyl-aryl and alkyl-alkyl chemical bonds together with novel furan oxygenated structures have been identified and quantified for the first time. In addition, the formation of lignin carbohydrate complexes bonds has been hypothesized at low severity and L/S. Based on the obtained data we were able to formulate a possible outlook of the occurring reactions during the hydrothermal treatment. Overall, such detailed structural information bridges the gap from process engineering to sustainable product development.Item AqSO biorefinery: a green and parameter-controlled process for the production of lignin-carbohydrate hybrid materials(Royal Society of Chemistry, 2022-09-07) Tarasov, Dmitry; Schlee, Philipp; Pranovich, Andrey; Moreno, Adrian; Wang, Luyao; Rigo, Davide; Sipponen, Mika H.; Xu, Chunlin; Balakshin, Mikhail; Department of Bioproducts and Biosystems; Lignin Chemistry; Åbo Akademi University; Stockholm UniversityThe current biorefineries are focused on the comprehensive fractionation of biomass components into separate lignin and carbohydrate fractions for the production of materials, platform chemicals and biofuel. However, it has become obvious that the combination of lignin and carbohydrates can have significant technical, environmental, and economic benefits as opposed to their separate use. Herein, we developed a green, simple, and flexible biorefinery concept for the integrated utilization of all major biomass components for high-value applications with the focus on functional lignin-carbohydrate hybrids (LCHs). The established process consisted of a modified hydrothermal treatment (HTT) of birch wood followed by solvent extraction of the resulting solids and is therefore named AquaSolv Omni (AqSO) biorefinery. The AqSO biorefinery produces three major streams: hydrolysate (hemicellulose-derived products), solvent-extracted lignin-carbohydrate complexes (LCCs) and cellulose-rich fibers. Specific process conditions were found to facilitate the production of LCCs of different types in high yields as a new valuable and industrially realistic process stream. The effect of the process severity and liquid to solid (L/S) ratio on the yields and compositions of the produced fractions as well as on the structure and properties of the extracted LCCs was investigated using state of the art NMR spectroscopy and molar mass distribution analysis among other methods. The high flexibility of the process allows for engineering of the resulting products in a wide range of chemical compositions, structures and physicochemical properties and therefore gives a good opportunity to optimize the products for specific high-value applications. The process can be easily combined with other biorefinery operations (e.g., enzymatic hydrolysis, pulping, bleaching) to be incorporated into existing value chains or create new ones and thus is suitable for different biorefinery scenarios. First examples of high-value applications of AqSO biorefinery LCHs are reported. LCC nanoparticles (LCCNPs) were produced for the first time directly from the solvent extract and their properties were investigated. LCCNPs could efficiently stabilize Pickering emulsions of tetrahydrofurfuryl methacrylate and allowed their free radical polymerization. In addition, AqSO LCHs showed promising results as wood adhesives. Overall, our results provide detailed information on the complex lignocellulosic fractions and bridge the gap from process engineering to sustainable product development.Item A feasibility study on green biorefinery of high lignin content agro-food industry waste through supercritical water treatment(ELSEVIER SCI LTD, 2021-11-10) Adamovic, Tijana; Tarasov, Dmitry; Demirkaya, Emre; Balakshin, Mikhail; Cocero, Maria José; Department of Bioproducts and Biosystems; Lignin Chemistry; University of ValladolidThis work discusses hydrolysis of defatted grape in supercritical water (SCW) at 380 °C and 260 bar from 0.18 s to 1 s focusing attention to sugars recovery in the liquid phase of the product and detailed characterization of remaining solid phase enriched in polyaromatics (e.g. lignin, flavonoids, etc.). After the longest reaction time of 1 s, 56% of carbohydrates could be recovered in the liquid phase, as a result of carbohydrate hydrolysis. The high content of insoluble lignin in biomass (36%), acts as a mass transfer limitation and presents an important feature in the hydrolysis process, slowing down the conversion of carbohydrate fraction, as after the maximum time of 1s, 10% of carbohydrates still remained in the solid phase. Milled wood lignin, extracted from biomass and dioxane extract from the solid phase were characterized in order to understand the main structural changes during the SCW hydrolysis process. Dioxane (80%) extraction of solids produces a very complex mixture of lipophilic extractives, flavonoids and lignin with a certain amount of chemically linked carbohydrates. 2D NMR analysis of dioxane extract shows remarkably subtle changes in the amounts of main lignin moieties (β-O-4′, β-β’ (resinol) and β-5 (phenylcoumaran)). This subtle change of the main lignin structures is an important feature in the further valorisation of this sulfur-free lignin residue.Item Lignin-first integrated hydrothermal treatment (HTT) and synthesis of low-cost biorefinery particles(AMERICAN CHEMICAL SOCIETY, 2020-01-21) Vergara Lourencon, Tainise; Garcia Greca, Luiz; Tarasov, Dmitry; Borrega, Marc; Tamminen, Tarja; Rojas Gaona, Orlando; Balakshin, Mikhail; Department of Bioproducts and Biosystems; Lignin Chemistry; Bio-based Colloids and Materials; VTT Technical Research Centre of FinlandHydrothermal treatments (HTT) are used in the biorefineries to effectively valorize carbohydrate fractions and their products. However, lignin is often marginalized as a secondary component. Herein, we propose a new biorefinery approach focused on lignin valorization. We demonstrate that high-value lignins can be extracted using a simple, green, and affordable process consisting of an optimized HTT followed by lignin extraction with aqueous acetone under ambient conditions. Significantly, the chemical structure and molecular mass of the lignin can be tailored by the selection of the process variables while maintaining a high yield, in the range of ∼60-90%. For example, the average molecular mass (Mw) of the isolated lignins is in the range between 2.5 and 5 kDa, while the amount of β-O-4 linkages is 4-28 per 100 Ar. The extracted lignins are further used to generate micro- and nanoparticles by using an aerosol flow system. The introduced lignin profiling affords control of particle properties, including average size and distribution, surface energy, and wettability. Overall, the suggested approach allows customization of lignin products while achieving a 58% reduction in the lignin particles production costs compared to the lowest prime figures reported so far.Item Machine Learning Optimization of Lignin Properties in Green Biorefineries(AMERICAN CHEMICAL SOCIETY, 2022-07-25) Löfgren, Joakim; Tarasov, Dmitry; Koitto, Taru; Rinke, Patrick; Balakshin, Mikhail; Todorović, Milica; Department of Applied Physics; Department of Bioproducts and Biosystems; Computational Electronic Structure Theory; Lignin Chemistry; Synthetic Biology; University of TurkuNovel biorefineries could transform lignin, an abundant biopolymer, from side-stream waste to high-value-Added byproducts at their site of production and with minimal experiments. Here, we report the optimization of the AquaSolv omni biorefinery for lignin using Bayesian optimization, a machine learning framework for sample-efficient and guided data collection. This tool allows us to relate the biorefinery conditions like hydrothermal pretreatment reaction severity and temperature with multiple experimental outputs, such as lignin structural features characterized using 2D nuclear magnetic resonance spectroscopy. By applying a Pareto front analysis to our models, we can find the processing conditions that simultaneously optimize the lignin yield and the amount of β-O-4 linkages for the depolymerization of lignin into platform chemicals. Our study demonstrates the potential of machine learning to accelerate the development of sustainable chemical processing techniques for targeted applications and products.Item Upgrading AqSo biorefinery products for high value applications(2021-12-17) Muratova, Madina; Tarasov, Dmitry; Kemiantekniikan korkeakoulu; Hummel, Michael
