Maximizing Populus tremula biomass conversion: synergistic pretreatment effects on sugars release and lignin recovery

Keywords

Biorefinery / Lignocellulosic biomass / Protic ionic liquid / Sugars / Lignin

References

[1] Abu-Omar MM, Barta K, Beckham GT, et al. . Guidelines for performing lignin-first biorefining. Energy Environ Sci, 2021, 14: 262-292

[2] Angeltveit CF, Várnai A, Eijsink VGH, Horn SJ. Enhancing enzymatic saccharification yields of cellulose at high solid loadings by combining different LPMO activities. Biotechnol Biofuels Bioprod, 2024, 17: 1-14

[3] Argyropoulos DDS, Crestini C, Dahlstrand C. Kraft lignin: a valuable, sustainable resource, opportunities challenges. ChemSusChem, 2023, 16: 202300492

[4] Babaeipour S, Nousiainen P, Garcia EM. Oxidative crosslinking for the development of barrier coatings utilizing lignin-containing cellulose nanofibrils and lignin nanoparticles. Food Packag Shelf Life, 2025, 49: 101538

[5] Balakshin MY, Capanema EA, Sulaeva I, et al. . New opportunities in the valorization of technical lignins. Chemsuschem, 2021, 14: 1016-1036

[6] Bangalore Ashok RP, Oinas P, Lintinen K, et al. . Techno-economic assessment for the large-scale production of colloidal lignin particles. Green Chem, 2018, 20: 4911-4919

[7] Baral NR, Shah A. Techno-economic analysis of cellulose dissolving ionic liquid pretreatment of lignocellulosic biomass for fermentable sugars production. Biofuels Bioprod Biorefining, 2016, 10: 70-88

[8] Baruah J, Nath BK, Sharma R, et al. . Recent trends in the pretreatment of lignocellulosic biomass for value-added products. Front Energy Res, 2018, 6: 1-19

[9] Bhatia R, Lad JB, Bosch M, et al. . Production of oligosaccharides and biofuels from Miscanthus using combinatorial steam explosion and ionic liquid pretreatment. Bioresour Technol, 2021, 323: 124625

[10] Brandt A, Gräsvik J, Hallett JP, Welton T. Deconstruction of lignocellulosic biomass with ionic liquids. Green Chem, 2013, 15: 550-583

[11] Cabrera MN, Arrosbide MF, Franzoni P, Cassella N. Integrated forest biorefineries: green liquor extraction in eucalyptus wood prior to kraft pulping. Biomass Convers Biorefinery, 2016, 6: 465-474

[12] Cabrera MN, Rossi A, Guarino JI, et al. . Alkaline extraction and ethanol precipitation of high-molecular-weight xylan compounds from eucalyptus residues. Polym (Basel), 2025, 17: 1-21

[13] Cahyanti MN, Shanmugam S, Kikas T. Synergistic effects of torrefaction and alkaline pretreatment on sugar and bioethanol production from wood waste. Energies, 2023, 16: 1706

[14] Chambon CL, Verdía P, Fennell PS, Hallett JP. Process intensification of the ionoSolv pretreatment: effects of biomass loading, particle size and scale-up from 10 mL to 1 L. Sci Rep, 2021, 11: 1-15

[15] Cheng M, Huang H, Dien BS, Singh V. The costs of sugar production from different feedstocks and processing technologies. Biofuels Bioprod Biorefining, 2019, 13: 723-739

[16] Climent Barba F, Grasham O, Puri DJ, Blacker AJ. A simple techno-economic assessment for scaling-up the enzymatic hydrolysis of MSW Pulp. Front Energy Res, 2022, 10: 1-13

[17] da Rodrigues A, Errico M, Rong BG. Techno-economic analysis of organosolv pretreatment process from lignocellulosic biomass. Clean Technol Environ Policy, 2018, 20: 1401-1412

[18] Dessbesell L, Yuan Z, Hamilton S, et al. . Bio-based polymers production in a kraft lignin biorefinery: techno‐economic assessment. Biofuels Bioprod Biorefining, 2018, 12: 239-250

[19] Dessbesell L, Souzanchi S, Venkateswara Rao KT, et al. . Production of 2,5-furandicarboxylic acid (FDCA) from starch, glucose, or high‐fructose corn syrup: techno‐economic analysis. Biofuels Bioprod Biorefining, 2019, 13: 1234-1245

[20] Dezashibi AHM, Hallett JP, Fennell PS. Design and operation of a cost-effective reactor for large protic ionic liquid synthesis. Chem Eng Process Process Intensif, 2025, 213: 110312

[21] Giummarella N, Pu Y, Ragauskas AJ, Lawoko M. A critical review on the analysis of lignin carbohydrate bonds. Green Chem, 2019, 21: 1573-1595

[22] Gominho J, Costa R, Lourenço A, et al. . The effect of different pre-treatments to improve delignification of eucalypt stumps in a biorefinery context. Bioresour Technol Rep, 2019, 6: 89-95

[23] Gong Z, Yang G, Song J, et al. . Understanding the promoting effect of non-catalytic protein on enzymatic hydrolysis efficiency of lignocelluloses. Bioresour Bioprocess, 2021, 8: 9

[24] Gschwend FJV, Chambon CL, Biedka M, et al. . Quantitative glucose release from softwood after pretreatment with low-cost ionic liquids. Green Chem, 2019, 21: 692-703

[25] Guigou M, Cabrera MN, Vique M, et al. . Combined pretreatments of eucalyptus sawdust for ethanol production within a biorefinery approach. Biomass Convers Biorefinery, 2019, 9: 293-304

[26] Hämäläinen V, Barajas-López JDD, Berlina Y, et al. . New thermostable endoglucanase from Spirochaeta thermophila and its mutants with altered substrate preferences. Appl Microbiol Biotechnol, 2021, 105: 1133-1145

[27] Hepner H, Lukason O, Lutter R. The value of hybrid aspen coppice investment under different discount rate, price and management scenarios: a case study of estonia. Forests, 2021, 12: 623

[28] Jiju PS, Patel AK, Shruthy NS, et al. . Sustainability through lignin valorization: recent innovations and applications driving industrial transformation. Bioresour Bioprocess, 2025, 12: 88

[29] Khan S (2025) Sequential depolymerization of lignin from softwood biomass enabled by integrated protic ionic liquid-enzyme pretreatment. Estonian University of Life Sciences https://doi.org/10.15159/emu.166

[30] Khan S, Rauber D, Shanmugam S, et al. . Efficient lignin fractionation from scots pine (Pinus sylvestris) using ammonium-based protic ionic liquid: process optimization and characterization of recovered lignin. Polym (Basel), 2022, 14: 4637

[31] Khan S, Rauber D, Wang L, et al. . Lignin depolymerization from softwood biomass using integrated protic ionic liquid-enzyme pretreatment. RSC Sustain, 2025, 3: 4466-4477

[32] Klein-Marcuschamer D, Simmons BA, Blanch HW. Techno-economic analysis of a lignocellulosic ethanol biorefinery with ionic liquid pre-treatment. Biofuels Bioprod Biorefining, 2011, 5: 562-569

[33] Klein-Marcuschamer D, Simmons BA, Blanch HW. Techno‐economic analysis of a lignocellulosic ethanol biorefinery with ionic liquid pre‐treatment. Biofuels Bioprod Biorefining, 2011, 5: 562-569

[34] Koistinen A, Vuorinen T, Maloney T. The effect of alkaline pre-treatment on cellulose pulp fiber dissolution. Carbohydr Polym Technol Appl, 2025, 11: 100978

[35] Krzywnicka M, Barner L. On strategic behavior in electricity markets during the 2022 energy crisis: an ex-post analysis for the German power sector. Energy Rep, 2025, 13: 5474-5485

[36] Kurian JK, Gariepy Y, Orsat V, Raghavan GSV. Comparison of steam-assisted versus microwave-assisted treatments for the fractionation of sweet sorghum bagasse. Bioresour Bioprocess, 2015, 2: 30

[37] Lawoko M, Henriksson G, Gellerstedt G. Structural differences between the lignin-carbohydrate complexes present in wood and in chemical pulps. Biomacromolecules, 2005, 6: 3467-3473

[38] Liao Y, Koelewijn SF, van den Bossche G, et al. . A sustainable wood biorefinery for low-carbon footprint chemicals production. Science (80-), 2020, 367: 1385-1390

[39] Liu R, Smeds A, Wang L, et al. . Fractionation of lignin with decreased heterogeneity: based on a detailed characteristics study of sequentially extracted softwood kraft lignin. ACS Sustain Chem Eng, 2021, 9: 13862-13873

[40] Liu R, Smeds A, Tirri T, et al. . Influence of carbohydrates covalently bonded with lignin on solvent fractionation, thermal properties, and nanoparticle formation of lignin. ACS Sustain Chem Eng, 2022, 10: 14588-14599

[41] Liu W, Jiang C, Li X, et al. . Microwave-assisted DES fabrication of lignin-containing cellulose nanofibrils and its derived composite conductive hydrogel. Carbohydr Polym, 2024, 328: 121741

[42] Losada CB, Di Bartolomeo F, Wentzel A, et al. . Simultaneous production of fatty acids and amino polysaccharides from Norway spruce hydrolysates using oleaginous Mucor circinelloides. Sci Rep, 2025, 15: 1-13

[43] Meys R, Bachmann M, Winter B, et al. . Plastics by a circular carbon economy. Science (80-), 2021, 76: 71-76

[44] Momayez F, Hedenström M, Stagge S. Valorization of hydrolysis lignin from a spruce-based biorefinery by applying γ-valerolactone treatment. Bioresour Technol, 2022, 359: 127466

[45] Morizet-davis J, Wang S, Kim H. Sustainable production of xylo-oligosaccharides: a comparative environmental life cycle and techno-economic analysis. Bioresour Technol Rep, 2025, 8: 102233

[46] Nair LG, Agrawal K, Verma P. Organosolv pretreatment: an in-depth purview of mechanics of the system. Bioresour Bioprocess, 2023, 10: 50

[47] Österberg M, Sipponen MH, Mattos BD, Rojas OJ. Spherical lignin particles: a review on their sustainability and applications. Green Chem, 2020, 22: 2712-2733

[48] Pari P, Eshtiaghi N, Othman M, Palani SG. A comparative assessment and economic implications of physical, chemical, and enzymatic treatments of lignocellulosic waste. Bioresour Bioprocess, 2025, 12: 115

[49] Patel R, Rajaraman TS, Rana PH, et al. . A review on techno-economic analysis of lignocellulosic biorefinery producing biofuels and high-value products. Results Chem, 2025, 13: 102052

[50] Penín L, Peleteiro S, Santos V, et al. . Selective fractionation and enzymatic hydrolysis of Eucalyptus nitens wood. Cellulose, 2019, 26: 1125-1139

[51] Punia Bangar S, Love R, Whiteside WS, et al. . Isolation and characterisation of cellulose nanocrystals from kudzu (Pueraria montana var. lobata): a sustainable packaging material. Int J Food Sci Technol, 2023, 58: 4752-4760

[52] Qin L, Li WC, Liu L, et al. . Inhibition of lignin-derived phenolic compounds to cellulase. Biotechnol Biofuels, 2016, 9: 1-10

[53] Ragauskas AJ, Beckham GT, Biddy MJ. Lignin valorization: improving lignin processing in the biorefinery. Science (80-), 2014, 344: 6185 80-.)

[54] Rodrigues JS, Lima V, Araújo LCP, Botaro VR. Lignin fractionation methods: can lignin fractions be separated in a true industrial process?. Ind Eng Chem Res, 2021, 60: 10863-10881

[55] Rooni V, Sjulander N, Cristobal-Sarramian A, et al. . The efficiency of nitrogen explosion pretreatment on common aspen—Populus tremula: N2– VS steam explosion. Energy, 2021, 220: 119741

[56] Schutyser W, Renders T, Van Den Bosch S, et al. . Chemicals from lignin: an interplay of lignocellulose fractionation, depolymerisation, and upgrading. Chem Soc Rev, 2018, 47: 852-908

[57] Shi R, Zhang Z, Zhang J, et al. . A comparative study on enhanced enzymatic hydrolysis of diverse herbaceous and woody wastes by promising dilute acid and alkaline pretreatments. Bioresour Bioprocess, 2025, 12: 36

[58] Singh SK, Savoy AW, Yuan Z, et al. . Integrated two-stage alkaline-oxidative pretreatment of hybrid poplar. Part 1: impact of alkaline pre-extraction conditions on process performance and lignin properties. Ind Eng Chem Res, 2019, 58: 15989-15999

[59] Solarte-Toro JC, Rueda-Duran CA, Ortiz-Sanchez M, Cardona Alzate CA. A comprehensive review on the economic assessment of biorefineries: The first step towards sustainable biomass conversion. Bioresour Technol Rep, 2021, 15: 100776

[60] Sun Z, Fridrich B, De Santi A, et al. . Bright side of lignin depolymerization: toward new platform chemicals. Chem Rev, 2018, 118: 614-678

[61] Sun LL, Sun SN, Cao XF, Yao SQ. An integrated biorefinery strategy for Eucalyptus fractionation and co-producing glucose, furfural, and lignin based on deep eutectic solvent/cyclopentyl methyl ether system. Carbohydr Polym, 2024, 343: 122420

[62] Tarasov D, Leitch M, Fatehi P. Lignin-carbohydrate complexes: properties, applications, analyses, and methods of extraction: a review. Biotechnol Biofuels, 2018, 11: 1-28

[63] Tofani G, Jasiukaitytė-Grojzdek E, Grilc M, Likozar B. Organosolv biorefinery: resource-based process optimisation, pilot technology scale-up and economics. Green Chem, 2023, 26: 186-201

[64] Van den Tschulkow M, Compernolle T, Bosch S. Integrated techno-economic assessment of a biorefinery process: the high-end valorization of the lignocellulosic fraction in wood streams. J Clean Prod, 2020, 266: 122022

[65] Vaaje-Kolstad G, Westereng B, Horn SJ. An oxidative enzyme boosting cellulose degradation by cellulases. Science (80-), 2010, 330: 219-222

[66] Vanholme R, Demedts B, Morreel K, et al. . Lignin biosynthesis and structure. Plant Physiol, 2010, 153: 895-905

[67] Verdía Barbará P, Choudhary H, Nakasu PS, et al. . Recent advances in the use of ionic liquids and deep eutectic solvents for lignocellulosic biorefineries and biobased chemical and material production. Chem Rev, 2025, 125: 5461-5583

[68] Wang F, Dong H, Yu W, et al. . Enhanced enzymatic sugar production from corn stover by combination of water extraction and glycerol-assisted instant catapult steam explosion. Bioresour Bioprocess, 2024, 11: 31

[69] Wang X, Wu R, Zhang Y, et al. . Direct conversion of hemicellulose in biomass to functional diformylxylose with a recyclable organic co-solvent. Ind Crops Prod, 2025, 238: 122363

[70] Weerachanchai P, Leong SSJ, Chang MW, et al. . Improvement of biomass properties by pretreatment with ionic liquids for bioconversion process. Bioresour Technol, 2012, 111: 453-459

[71] Wijaya C, Sangadji NL, Muharja M. An integrated green fractionation of coconut husk: hydrothermal and deep eutectic solvent pretreatment for enhanced sugar and lignin production. Bioresour Technol Rep, 2025, 29: 102078

[72] Xu J, Liu B, Hou H, Hu J. Pretreatment of eucalyptus with recycled ionic liquids for low-cost biorefinery. Bioresour Technol, 2017, 234: 406-414

[73] Xu J, Li C, Dai L, et al. . Biomass fractionation and lignin fractionation towards lignin valorization. Chemsuschem, 2020, 13: 4284-4295

[74] Xu Y, Rios DC, Wang S, et al. . Process design and techno-economic analysis for the lignin oil solvent recovery and purification process. J Clean Prod, 2024, 434: 139999

[75] Yang SM, Muazu RI, Tran E, et al. . Sustainable low-cost carbon fibres produced by integrating wood fractionation with lignin fibre spinning. RSC Sustain, 2025, 3: 3972-3986

[76] Zang G, Shah A, Wan C. Techno-economic analysis of an integrated biorefinery strategy based on one-pot biomass fractionation and furfural production. J Clean Prod, 2020, 260: 120837

[77] Zhang Z, Yang R, Gao W, Yao X. Investigation of [Emim][OAc] as a mild pretreatment solvent for enhancing the sulfonation efficiency of alkali lignin. RSC Adv, 2017, 7: 31009-31017

[78] Zhong N, Chandra R, Yamamoto M, et al. . Sulphite addition during steam pretreatment enhanced both enzyme-mediated cellulose hydrolysis and ethanol production. Bioresour Bioprocess, 2022, 9: 71

[79] Zhou S, Xu J, Zhang Z, et al. . Efficient and sustainable fractionation of eucalyptus biomass into high quality cellulose and lignin using a novel ternary deep eutectic solvent. Chem Eng J, 2025,

[80] Zibunas C, Meys R, Kätelhön A, Bardow A. The cost and climate impact of myopic investment decisions in the chemical industry. Comput Chem Eng, 2024, 187: 108721

Funding

Universität des Saarlandes (1036)

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