{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,6]],"date-time":"2026-02-06T23:27:21Z","timestamp":1770420441783,"version":"3.49.0"},"reference-count":54,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2022,6,27]],"date-time":"2022-06-27T00:00:00Z","timestamp":1656288000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"The University of Bergen","award":["NNF20SA0066233"],"award-info":[{"award-number":["NNF20SA0066233"]}]},{"name":"The University of Bergen","award":["2015\/20510-9"],"award-info":[{"award-number":["2015\/20510-9"]}]},{"name":"The University of Bergen","award":["2015\/24813-6"],"award-info":[{"award-number":["2015\/24813-6"]}]},{"name":"The University of Bergen","award":["2013\/13953-6"],"award-info":[{"award-number":["2013\/13953-6"]}]},{"name":"The University of Bergen","award":["001"],"award-info":[{"award-number":["001"]}]},{"name":"The University of Bergen","award":["1085"],"award-info":[{"award-number":["1085"]}]},{"name":"Novo Nordisk Foundation (NNF), Denmark","award":["NNF20SA0066233"],"award-info":[{"award-number":["NNF20SA0066233"]}]},{"name":"Novo Nordisk Foundation (NNF), Denmark","award":["2015\/20510-9"],"award-info":[{"award-number":["2015\/20510-9"]}]},{"name":"Novo Nordisk Foundation (NNF), Denmark","award":["2015\/24813-6"],"award-info":[{"award-number":["2015\/24813-6"]}]},{"name":"Novo Nordisk Foundation (NNF), Denmark","award":["2013\/13953-6"],"award-info":[{"award-number":["2013\/13953-6"]}]},{"name":"Novo Nordisk Foundation (NNF), Denmark","award":["001"],"award-info":[{"award-number":["001"]}]},{"name":"Novo Nordisk Foundation (NNF), Denmark","award":["1085"],"award-info":[{"award-number":["1085"]}]},{"name":"Funda\u00e7\u00e3o de Amparo \u00e0 Pesquisa do Estado de S\u00e3o Paulo (FAPESP), Brazil","award":["NNF20SA0066233"],"award-info":[{"award-number":["NNF20SA0066233"]}]},{"name":"Funda\u00e7\u00e3o de Amparo \u00e0 Pesquisa do Estado de S\u00e3o Paulo (FAPESP), Brazil","award":["2015\/20510-9"],"award-info":[{"award-number":["2015\/20510-9"]}]},{"name":"Funda\u00e7\u00e3o de Amparo \u00e0 Pesquisa do Estado de S\u00e3o Paulo (FAPESP), Brazil","award":["2015\/24813-6"],"award-info":[{"award-number":["2015\/24813-6"]}]},{"name":"Funda\u00e7\u00e3o de Amparo \u00e0 Pesquisa do Estado de S\u00e3o Paulo (FAPESP), Brazil","award":["2013\/13953-6"],"award-info":[{"award-number":["2013\/13953-6"]}]},{"name":"Funda\u00e7\u00e3o de Amparo \u00e0 Pesquisa do Estado de S\u00e3o Paulo (FAPESP), Brazil","award":["001"],"award-info":[{"award-number":["001"]}]},{"name":"Funda\u00e7\u00e3o de Amparo \u00e0 Pesquisa do Estado de S\u00e3o Paulo (FAPESP), Brazil","award":["1085"],"award-info":[{"award-number":["1085"]}]},{"name":"Coordena\u00e7\u00e3o de Aperfei\u00e7oamento de Pessoal de N\u00edvel Superior (CAPES), Brazil","award":["NNF20SA0066233"],"award-info":[{"award-number":["NNF20SA0066233"]}]},{"name":"Coordena\u00e7\u00e3o de Aperfei\u00e7oamento de Pessoal de N\u00edvel Superior (CAPES), Brazil","award":["2015\/20510-9"],"award-info":[{"award-number":["2015\/20510-9"]}]},{"name":"Coordena\u00e7\u00e3o de Aperfei\u00e7oamento de Pessoal de N\u00edvel Superior (CAPES), Brazil","award":["2015\/24813-6"],"award-info":[{"award-number":["2015\/24813-6"]}]},{"name":"Coordena\u00e7\u00e3o de Aperfei\u00e7oamento de Pessoal de N\u00edvel Superior (CAPES), Brazil","award":["2013\/13953-6"],"award-info":[{"award-number":["2013\/13953-6"]}]},{"name":"Coordena\u00e7\u00e3o de Aperfei\u00e7oamento de Pessoal de N\u00edvel Superior (CAPES), Brazil","award":["001"],"award-info":[{"award-number":["001"]}]},{"name":"Coordena\u00e7\u00e3o de Aperfei\u00e7oamento de Pessoal de N\u00edvel Superior (CAPES), Brazil","award":["1085"],"award-info":[{"award-number":["1085"]}]},{"name":"Hellenic Foundation for Research and Innovation (HFRI)","award":["NNF20SA0066233"],"award-info":[{"award-number":["NNF20SA0066233"]}]},{"name":"Hellenic Foundation for Research and Innovation (HFRI)","award":["2015\/20510-9"],"award-info":[{"award-number":["2015\/20510-9"]}]},{"name":"Hellenic Foundation for Research and Innovation (HFRI)","award":["2015\/24813-6"],"award-info":[{"award-number":["2015\/24813-6"]}]},{"name":"Hellenic Foundation for Research and Innovation (HFRI)","award":["2013\/13953-6"],"award-info":[{"award-number":["2013\/13953-6"]}]},{"name":"Hellenic Foundation for Research and Innovation (HFRI)","award":["001"],"award-info":[{"award-number":["001"]}]},{"name":"Hellenic Foundation for Research and Innovation (HFRI)","award":["1085"],"award-info":[{"award-number":["1085"]}]},{"name":"General Secretariat for Research and Technology (GSRT),","award":["NNF20SA0066233"],"award-info":[{"award-number":["NNF20SA0066233"]}]},{"name":"General Secretariat for Research and Technology (GSRT),","award":["2015\/20510-9"],"award-info":[{"award-number":["2015\/20510-9"]}]},{"name":"General Secretariat for Research and Technology (GSRT),","award":["2015\/24813-6"],"award-info":[{"award-number":["2015\/24813-6"]}]},{"name":"General Secretariat for Research and Technology (GSRT),","award":["2013\/13953-6"],"award-info":[{"award-number":["2013\/13953-6"]}]},{"name":"General Secretariat for Research and Technology (GSRT),","award":["001"],"award-info":[{"award-number":["001"]}]},{"name":"General Secretariat for Research and Technology (GSRT),","award":["1085"],"award-info":[{"award-number":["1085"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Energies"],"abstract":"<jats:p>This work evaluates the effect of feedstock type and composition on the conversion of lignin to liquid by solvolysis with formic acid as hydrogen donor (LtL), by analyzing the yields and molecular composition of the liquid products and interpreting them in terms of both the type and the preprocessing of the lignocellulosic biomass using chemometric data analysis. Lignin samples of different types and purities from softwood, hardwood, and grasses (rice straw and corn stover) have been converted to bio-oil, and the molecular composition analyzed and quantified using GC-MS. LtL solvolysis was found to be a robust method for lignin conversion in terms of converting all samples into bio-oils rich in phenolic compounds regardless of the purity of the lignin sample. The bio-oil yields ranged from 24\u201394 wt.% relative to lignin input and could be modelled well as a function of the elemental composition of the feedstock. On a molecular basis, the softwood-derived bio-oil contained the most guaiacol-derivatives, and syringol was correlated to hardwood. However, the connection between compounds in the bio-oil and lignin origin was less pronounced than the effects of the methods for biomass fractionation, showing that the pretreatment of the biomass dominates both the yield and molecular composition of the bio-oil and must be addressed as a primary concern when utilization of lignin in a biorefinery is planned.<\/jats:p>","DOI":"10.3390\/en15134707","type":"journal-article","created":{"date-parts":[[2022,6,27]],"date-time":"2022-06-27T22:31:14Z","timestamp":1656369074000},"page":"4707","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["The Consistency of Yields and Chemical Composition of HTL Bio-Oils from Lignins Produced by Different Preprocessing Technologies"],"prefix":"10.3390","volume":"15","author":[{"given":"Hilde Vik","family":"Halleraker","sequence":"first","affiliation":[{"name":"Department of Chemistry, University of Bergen, All\u00e8gaten 41, 5007 Bergen, Norway"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3642-6324","authenticated-orcid":false,"given":"Konstantinos","family":"Kalogiannis","sequence":"additional","affiliation":[{"name":"Chemical Process and Energy Resources Institute (CPERI), Centre for Research and Technology Hellas (CERTH), 6th km Harilaou-Thermi Rd, 57001 Thessaloniki, Greece"}]},{"given":"Angelos","family":"Lappas","sequence":"additional","affiliation":[{"name":"Chemical Process and Energy Resources Institute (CPERI), Centre for Research and Technology Hellas (CERTH), 6th km Harilaou-Thermi Rd, 57001 Thessaloniki, Greece"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7134-6346","authenticated-orcid":false,"given":"Rafael C. A.","family":"Castro","sequence":"additional","affiliation":[{"name":"Departmento de Biotecnologia Escola de Engenharia de Lorena, Universidade de S\u00e3o Paulo, Lorena 12602-810, SP, Brazil"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4539-8783","authenticated-orcid":false,"given":"Ines C.","family":"Roberto","sequence":"additional","affiliation":[{"name":"Departmento de Biotecnologia Escola de Engenharia de Lorena, Universidade de S\u00e3o Paulo, Lorena 12602-810, SP, Brazil"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7182-6198","authenticated-orcid":false,"given":"Solange I.","family":"Mussatto","sequence":"additional","affiliation":[{"name":"Department of Biotechnology and Biomedicine, Technical University of Denmark, S\u00f8ltofts Plads, Building 223, 2800 Kongens Lyngby, Denmark"}]},{"given":"Tanja","family":"Barth","sequence":"additional","affiliation":[{"name":"Department of Chemistry, University of Bergen, All\u00e8gaten 41, 5007 Bergen, Norway"}]}],"member":"1968","published-online":{"date-parts":[[2022,6,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Fang, Z., and Smith, J.R.L. (2016). Properties, Chemical Characteristics and Application of Lignin and Its Derivatives. Production of Biofuels and Chemicals from Lignin, Springer.","DOI":"10.1007\/978-981-10-1965-4"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Varanasi, P., Singh, P., Auer, M., Adams, P.D., Simmons, B.A., and Singh, S. (2013). Survey of renewable chemicals produced from lig-nocellulosic biomass during ionic liquid pretreatment. Biotechnol. Biofuels, 6.","DOI":"10.1186\/1754-6834-6-14"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Mussatto, S.I., and Dragone, G.M. (2016). Chapter 1 Biomass Pretreatment, Biorefineries, and Potential Products for a Bioeconomy De-velopment. Biomass Fractionation Technologies for a Lignocellulosic Feedstock Based Biorefinery, Elsevier.","DOI":"10.1016\/B978-0-12-802323-5.00001-3"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1016\/j.biombioe.2018.09.007","article-title":"Advances and opportunities in biomass conversion technologies and biorefineries for the development of a bio-based economy","volume":"119","author":"Yamakawa","year":"2018","journal-title":"Biomass Bioenergy"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Cao, Y., Chen, S.S., Zhang, S., Ok, Y.S., Matsagar, B.M., Wu, K.C.W., and Tsang, D.C.W. (2019). Advances in lignin valorization towards bio-based chemicals and fuels: Lignin biorefinery. Bioresour. Technol., 291.","DOI":"10.1016\/j.biortech.2019.121878"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"506","DOI":"10.1016\/j.rser.2012.12.022","article-title":"Liquid fuels, hydrogen and chemicals from lignin: A critical review","volume":"21","author":"Azadi","year":"2013","journal-title":"Renew. Sustain. Energy Rev."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"218","DOI":"10.1016\/j.carbpol.2007.03.021","article-title":"Lignin recovery from brewer\u2019s spent grain black liquor","volume":"70","author":"Mussatto","year":"2007","journal-title":"Carbohydr. Polym."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"852","DOI":"10.1039\/C7CS00566K","article-title":"Chemicals from lignin: An interplay of lignocellulose fractionation, depolymerisation, and upgrading","volume":"47","author":"Schutyser","year":"2018","journal-title":"Chem. Soc. Rev."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1386","DOI":"10.1002\/marc.201100242","article-title":"Polyalkylenehydroxybenzoates (PAHBs): Biorenewable Aro-matic\/Aliphatic Polyesters from Lignin","volume":"32","author":"Mialon","year":"2011","journal-title":"Macromol. Rapid Commun."},{"key":"ref_10","unstructured":"Matheus, P. (2018). Compositional Variability of Lignin in Biomass. Lignin\u2014Trends and Applications, IntechOpem."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1748","DOI":"10.1039\/C5EE00204D","article-title":"Reductive lignocellulose fractionation into soluble lignin-derived phenolic monomers and dimers and processable carbohydrate pulps","volume":"8","author":"Schutyser","year":"2015","journal-title":"Energy Environ. Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"3280","DOI":"10.1002\/cssc.201600648","article-title":"Hydrogen-free catalytic fractionation of woody biomass","volume":"9","author":"Galkin","year":"2016","journal-title":"ChemSusChem"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Anderson, E.M., Stone, M.L., Katahira, R., Reed, M., Muchero, W., Ramirez, K.J., Beckham, G.T., and Rom\u00e1n-Leshkov, Y. (2019). Differ-ences in S\/G ratio in natural poplar variants do not predict catalytic depolymerization monomer yields. Nat. Commun., 10.","DOI":"10.1038\/s41467-019-09986-1"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"10595","DOI":"10.1021\/ie301487v","article-title":"Modeling the Lignin Degradation Kinetics in an Ethanol\/Formic Acid Solvolysis Approach. Part 1. Kinetic Model Development","volume":"51","author":"Gasson","year":"2012","journal-title":"Ind. Eng. Chem. Res."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"3195","DOI":"10.1007\/s12649-019-00701-1","article-title":"Effect of Process Variables on the Solvolysis Depolymerization of Pine Kraft Lignin","volume":"11","author":"Goldmann","year":"2020","journal-title":"Waste Biomass Valoriz."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1276","DOI":"10.1016\/j.cherd.2009.05.008","article-title":"An integrated process to produce vanillin and lignin-based polyurethanes from Kraft lignin","volume":"87","author":"Silva","year":"2009","journal-title":"Chem. Eng. Res. Des."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1016\/j.indcrop.2004.04.016","article-title":"Review of current and future softwood kraft lignin process chemistry","volume":"20","author":"Chakar","year":"2004","journal-title":"Ind. Crops Prod."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1002\/ceat.201000270","article-title":"Lignin Depolymerization and Conversion: A Review of Thermochemical Methods","volume":"34","author":"Pandey","year":"2011","journal-title":"Chem. Eng. Technol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"781","DOI":"10.1007\/s12649-015-9387-y","article-title":"Lignocellulosic Biomass Fractionation as a Pretreatment Step for Production of Fuels and Green Chemicals","volume":"6","author":"Kalogiannis","year":"2015","journal-title":"Waste Biomass Valoriz."},{"key":"ref_20","unstructured":"Baskar, C., Baskar, S., and Dhillon, R.S. (2012). Organosolv Fractionation of Lignocelluloses for Fuels, Chemicals and Materials: A Biorefinery Processing Perspective. Biomass Conversion: The Interface of Biotechnology, Chemistry and Materials Science, Springer."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1016\/j.indcrop.2003.12.015","article-title":"Simultaneous saccharification and fermentation (SSF) of industrial wastes for the production of ethanol","volume":"20","author":"Szengyel","year":"2004","journal-title":"Ind. Crops Prod."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"985","DOI":"10.1007\/BF00127439","article-title":"The effects of phosphoric acid pretreatment on conversion of cellulose to ethanol at 45 \u00b0C using the thermotolerant yeast Kluyveromyces marxianus IMB3","volume":"17","author":"Nilsson","year":"1995","journal-title":"Biotechnol. Lett."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1186\/s13068-019-1634-1","article-title":"Pretreatment for biorefineries: A review of common methods for efficient utilisation of lignocellulosic materials","volume":"12","author":"Galbe","year":"2019","journal-title":"Biotechnol. Biofuels"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Echresh Zadeh, Z., Abdulkhani, A., and Saha, B. (2020). Characterization of Fast Pyrolysis Bio-Oil from Hardwood and Softwood Lignin. Energies, 13.","DOI":"10.3390\/en13040887"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Du, B., Chen, C., Sun, Y., Yu, M., Yang, M., Wang, X., and Zhou, J. (2020). Catalytic conversion of lignin to bio-oil over PTA\/MCM-41 catalyst assisted by ultrasound acoustic cavitation. Fuel Process. Technol., 206.","DOI":"10.1016\/j.fuproc.2020.106479"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"546","DOI":"10.1016\/j.rser.2013.07.013","article-title":"Hydrothermal conversion of lignin: A review","volume":"27","author":"Kang","year":"2013","journal-title":"Renew. Sustain. Energy Rev."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"7183","DOI":"10.1021\/acs.energyfuels.0c01164","article-title":"Selective Production of Phenolic Monomers and Biochar by Py-rolysis of Lignin with Internal Recycling of Heavy Oil","volume":"34","author":"Liu","year":"2020","journal-title":"Energy Fuels"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Camas, K.L., and Ullah, A. (2022). Depolymerization of lignin into high-value products. Biocatal. Agric. Biotechnol., 40.","DOI":"10.1016\/j.bcab.2022.102306"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1371","DOI":"10.1021\/ef700631w","article-title":"Towards a Lignincellulosic Biorefinery: Direct One-Step Conversion of Lignin to Hydrogen-Enriched Biofuel","volume":"22","author":"Kleinert","year":"2008","journal-title":"Energy Fuels"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"736","DOI":"10.1002\/ceat.200800073","article-title":"Phenols from Lignin","volume":"31","author":"Kleinert","year":"2008","journal-title":"Chem. Eng. Technol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"108","DOI":"10.1016\/j.jaap.2008.09.019","article-title":"Optimizing solvolysis conditions for integrated depolymerisation and hydrodeoxygenation of lignin to produce liquid biofuel","volume":"85","author":"Kleinert","year":"2009","journal-title":"J. Anal. Appl. Pyrolysis"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"477","DOI":"10.1016\/j.jaap.2011.09.004","article-title":"Palladium-Nafion SAC-13 catalysed depolymerisation of lignin to phenols in formic acid and water","volume":"92","author":"Liguori","year":"2011","journal-title":"J. Anal. Appl. Pyrolysis"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"208","DOI":"10.1016\/j.jaap.2016.03.003","article-title":"The effect of solvent and input material pretreatment on product yield and composition of bio-oils from lignin solvolysis","volume":"119","author":"Barth","year":"2016","journal-title":"J. Anal. Appl. Pyrolysis"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"713","DOI":"10.1016\/j.jaap.2015.04.020","article-title":"Simultaneous catalytic de-polymerization and hydrodeoxygenation of lignin in water\/formic acid media with Rh\/Al2O3, Ru\/Al2O3 and Pd\/Al2O3 as bifunctional catalysts","volume":"113","author":"Hertzberg","year":"2015","journal-title":"J. Anal. Appl. Pyrolysis"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"754","DOI":"10.1002\/cssc.201601410","article-title":"Unraveling the Role of Formic Acid and the Type of Solvent in the Catalytic Conversion of Lignin: A Holistic Approach","volume":"10","author":"Gandarias","year":"2017","journal-title":"ChemSusChem"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"L\u00f8hre, C., Halleraker, H.V., and Barth, T. (2017). Composition of Lignin-to-Liquid Solvolysis Oils from Lignin Extracted in a Semi-Continuous Organosolv Process. Int. J. Mol. Sci., 18.","DOI":"10.3390\/ijms18010225"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"147","DOI":"10.1016\/j.biombioe.2017.02.014","article-title":"Organosolv extraction of softwood combined with lignin-to-liquid-solvolysis as a semi-continuous percolation reactor","volume":"99","author":"Kleinert","year":"2017","journal-title":"Biomass Bioenergy"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"497","DOI":"10.1016\/j.ijbiomac.2019.01.148","article-title":"Isolation and physicochemical characterization of different lignin streams generated during the second-generation ethanol production process","volume":"129","author":"Castro","year":"2019","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"410","DOI":"10.1016\/j.jaap.2015.08.021","article-title":"Pyrolysis of lignin with 2DGC quantification of lignin oil: Effect of lignin type, process temperature and ZSM-5 in situ upgrading","volume":"115","author":"Kalogiannis","year":"2015","journal-title":"J. Anal. Appl. Pyrolysis"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1186\/s13068-017-0737-9","article-title":"Production of high concentrated cellulosic ethanol by acetone\/water oxidized pretreated beech wood","volume":"10","author":"Katsimpouras","year":"2017","journal-title":"Biotechnol. Biofuels"},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Dimos, K., Paschos, T., Louloudi, A., Kalogiannis, K.G., Lappas, A.A., Papayannakos, N., Kekos, D., and Mamma, D. (2019). Effect of Various Pretreatment Methods on Bioethanol Production from Cotton Stalks. Fermentation, 5.","DOI":"10.3390\/fermentation5010005"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"433","DOI":"10.1002\/wics.101","article-title":"Principal component analysis","volume":"2","author":"Abdi","year":"2010","journal-title":"WIREs Comput. Stat."},{"key":"ref_43","unstructured":"Nortvedt, R., Brakstad, F., Kvalheim, O.M., and Lundstedt, T. (1996). Det matematiske grunnlaget for latent variabel-metoder. Anvendelse av Kjemometri Innen Forskning og Industri, Norsk Kjemisk Selskap and The Swedish Chemical Society."},{"key":"ref_44","unstructured":"Carlson, R., and Carlson, J.E. (2005). Chapter 18: Quantitative relations: Observed responses and experimental variations. Design and Optimization in Organic Synthesis, Elsevier."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"86","DOI":"10.1016\/j.biortech.2017.02.129","article-title":"Analysis of the effect of temperature and reaction time on yields, compositions and oil quality in catalytic and non-catalytic lignin solvolysis in a formic acid\/water media using experi-mental design","volume":"234","author":"Vogt","year":"2017","journal-title":"Bioresour. Technol."},{"key":"ref_46","first-page":"37","article-title":"Reactivity and reaction pathways in thermochemical treatment of selected lig-nin-like model compounds under hydrogen rich conditions","volume":"98","author":"Holmelid","year":"2012","journal-title":"JAAP"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"3102","DOI":"10.1021\/acssuschemeng.7b03057","article-title":"Lignin-to-Liquid-Solvolysis (LtL) of Organosolv Extracted Lignin","volume":"6","author":"Laugerud","year":"2018","journal-title":"ACS Sustain. Chem. Eng."},{"key":"ref_48","unstructured":"National Center for Biotechnology Information (2020, July 03). PubChem Database. Guaiacol, CID = 460, Available online: https:\/\/pubchem.ncbi.nlm.nih.gov\/compound\/guaiacol."},{"key":"ref_49","unstructured":"National Center for Biotechnology Information (2020, July 03). PubChem Database. 2-Methoxy-4-methylphenol, CID = 7144, Available online: https:\/\/pubchem.ncbi.nlm.nih.gov\/compound\/2-Methoxy-4-methylphenol."},{"key":"ref_50","unstructured":"National Center for Biotechnology Information (2020, July 03). PubChem Database. 4-Ethyl-2-methoxyphenol, CID = 62465, Available online: https:\/\/pubchem.ncbi.nlm.nih.gov\/compound\/4-Ethyl-2-methoxyphenol."},{"key":"ref_51","unstructured":"National Center for Biotechnology Information (2020, July 03). PubChem Database. 2-Methoxy-4-propylphenol, CID = 17739, Available online: https:\/\/pubchem.ncbi.nlm.nih.gov\/compound\/2-Methoxy-4-propylphenol."},{"key":"ref_52","doi-asserted-by":"crossref","unstructured":"Alhassan, Y., Hornung, U., and Bugaje, I.M. (2020). Lignin Hydrothermal Liquefaction into Bifunctional Chemicals: A Concise Review. Biorefinery Concepts, IntechOpen.","DOI":"10.5772\/intechopen.90860"},{"key":"ref_53","doi-asserted-by":"crossref","unstructured":"Fiege, H., Voges, H.-W., Hamamoto, T., Umemura, S., Iwata, T., Miki, H., Fujita, Y., Buysch, H.-J., Garbe, D., and Paulus, W. (2000). Phenol Derivatives. Ullmann\u2019s Encyclopedia of Industrial Chemistry, Wiley-VCH Verlag GmbH & Co. KGaA.","DOI":"10.1002\/14356007.a19_313"},{"key":"ref_54","doi-asserted-by":"crossref","unstructured":"Pilato, L. (2010). Phenols. Phenolic Resins: A Century of Progress, Springer.","DOI":"10.1007\/978-3-642-04714-5"}],"container-title":["Energies"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1073\/15\/13\/4707\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T23:39:09Z","timestamp":1760139549000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1073\/15\/13\/4707"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,6,27]]},"references-count":54,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2022,7]]}},"alternative-id":["en15134707"],"URL":"https:\/\/doi.org\/10.3390\/en15134707","relation":{},"ISSN":["1996-1073"],"issn-type":[{"value":"1996-1073","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,6,27]]}}}