{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T05:03:21Z","timestamp":1789621401366,"version":"build-2803163510"},"reference-count":51,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,15]],"date-time":"2026-09-15T00:00:00Z","timestamp":1789430400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"MAECI","award":["P.O. FESR Puglia 2014\/2020"],"award-info":[{"award-number":["P.O. FESR Puglia 2014\/2020"]}]},{"name":"EU","award":["LIFE20 ENV\/IT\/000452"],"award-info":[{"award-number":["LIFE20 ENV\/IT\/000452"]}]},{"award":["LIFE20 ENV\/IT\/000452"],"award-info":[{"award-number":["LIFE20 ENV\/IT\/000452"]}],"id":[{"id":"https:\/\/ror.org\/019w4f821","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>The environmental and economic challenges stemming from fossil fuel dependence and climate change highlight the urgent need for sustainable biofuels. Wastewater treatment byproducts, such as sewage sludge (SS), represent a promising, yet underutilized, feedstock for biodiesel production within a circular economy. This research proposes a closed-loop valorization strategy for wastewater treatment byproducts, integrating solventless lipid extraction with the pyrolysis (at 400, 550, and 750 \u00b0C) of lipid-free residual biomass to produce the relevant biochars (BC). BCs can be functionalized (sulfonation run at 175 \u00b0C, 24 h), characterized (CHNS, FTIR, XRD, SBET, TPD, SEM), and used as catalysts for the esterification reaction of the previously extracted lipids with methanol to produce biodiesel. The extracted lipids were reacted with methanol (1:10 molar ratio, 80 \u00b0C, 5 h) using 3 wt.% of sulfonated catalysts per gram of grease, producing fatty acid methyl esters in high yield and conversion (&gt;96%). Catalysts were easily and efficiently recoverable through centrifugation, rendering them stable and reusable for five cycles without losing their catalytic properties. This approach aims to transform SS into a valuable resource, fostering a more sustainable and efficient biofuel production system.<\/jats:p>","DOI":"10.3390\/molecules31183273","type":"journal-article","created":{"date-parts":[[2026,9,15]],"date-time":"2026-09-15T18:23:53Z","timestamp":1789496633000},"page":"3273","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Closed-Loop Valorization of Urban Sewage Sludge for Sustainable Biodiesel Production"],"prefix":"10.3390","volume":"31","author":[{"given":"Carlo","family":"Pastore","sequence":"first","affiliation":[{"name":"Water Research Institute (IRSA), National Research Council (CNR), Via F. de Blasio 5, 70132 Bari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"software","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"},{"role":"funding-acquisition","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0864-4268","authenticated-orcid":false,"given":"Luigi","family":"di Bitonto","sequence":"additional","affiliation":[{"name":"Water Research Institute (IRSA), National Research Council (CNR), Via F. de Blasio 5, 70132 Bari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"given":"Valeria","family":"D\u2019Ambrosio","sequence":"additional","affiliation":[{"name":"Water Research Institute (IRSA), National Research Council (CNR), Via F. de Blasio 5, 70132 Bari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2725-9245","authenticated-orcid":false,"given":"Antonella","family":"Angelini","sequence":"additional","affiliation":[{"name":"Water Research Institute (IRSA), National Research Council (CNR), Via F. de Blasio 5, 70132 Bari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"given":"Felipe de Jes\u00fas","family":"Villalobos-Delgado","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering, Instituto Tecnol\u00f3gico de Aguascalientes, Aguascalientes 20256, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8047-9116","authenticated-orcid":false,"given":"Didilia Ileana","family":"Mendoza-Castillo","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering, Instituto Tecnol\u00f3gico de Aguascalientes, Aguascalientes 20256, Mexico"},{"name":"Secretary of Science, Humanities, Technology and Innovation (SECIHTI), Mexico City 03940, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"software","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"},{"role":"funding-acquisition","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4102-2252","authenticated-orcid":false,"given":"Hilda Elizabeth","family":"Reynel-\u00c1vila","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering, Instituto Tecnol\u00f3gico de Aguascalientes, Aguascalientes 20256, Mexico"},{"name":"Secretary of Science, Humanities, Technology and Innovation (SECIHTI), Mexico City 03940, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8531-4804","authenticated-orcid":false,"given":"Maria","family":"Lacalamita","sequence":"additional","affiliation":[{"name":"Department of Earth and Geoenvironmental Sciences, University of Study of Bari \u201cAldo Moro\u201d, Via Orabona 4, 70125 Bari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"software","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"given":"Jakub","family":"Vagunda","sequence":"additional","affiliation":[{"name":"Faculty of Chemical Technology, University of Pardubice, Studentska\u2019 573, 532 10 Pardubice, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5971-1769","authenticated-orcid":false,"given":"Martin","family":"H\u00e1jek","sequence":"additional","affiliation":[{"name":"Faculty of Chemical Technology, University of Pardubice, Studentska\u2019 573, 532 10 Pardubice, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0197-3539","authenticated-orcid":false,"given":"Adri\u00e1n","family":"Bonilla-Petriciolet","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering, Instituto Tecnol\u00f3gico de Aguascalientes, Aguascalientes 20256, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"},{"role":"funding-acquisition","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"254","DOI":"10.1038\/s41560-019-0369-3","article-title":"Exnovating for a Renewable Energy Transition","volume":"4","author":"Davidson","year":"2019","journal-title":"Nat. Energy"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"19","DOI":"10.3390\/cleantechnol3010002","article-title":"Economic and Sustainability of Biodiesel Production\u2014A Systematic Literature Review","volume":"3","author":"Mizik","year":"2021","journal-title":"Clean Technol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"943","DOI":"10.1007\/s10098-023-02728-4","article-title":"Application of Waste Biomass for the Production of Biofuels and Catalysts: A Review","volume":"26","author":"Arias","year":"2024","journal-title":"Clean Technol. Environ. Policy"},{"key":"ref_4","unstructured":"Von Sperling, M. (2007). Wastewater Characteristics, Treatment and Disposal, IWA Publishing."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"100382","DOI":"10.1016\/j.biteb.2020.100382","article-title":"Urban Sewage Scum and Primary Sludge as Profitable Sources of Biodiesel and Biolubricants of New Generation","volume":"9","author":"Todisco","year":"2020","journal-title":"Bioresour. Technol. Rep."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"104000","DOI":"10.1016\/j.rineng.2025.104000","article-title":"Sewage Sludge as a Sustainable Feedstock for Biodiesel: Advances in Conversion Technologies and Catalytic Applications","volume":"25","author":"D","year":"2025","journal-title":"Results Eng."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"152991","DOI":"10.1016\/j.cej.2024.152991","article-title":"Solventless Recovery of Lipids from Urban Sewage Sludge: How to Sustainably Turn a Waste into a Valuable Source of Oleochemicals","volume":"494","author":"Locaputo","year":"2024","journal-title":"Chem. Eng. J."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"166501","DOI":"10.1016\/j.cej.2025.166501","article-title":"Integrated Sewage Sludge Treatment for the Sustainable Recovery of Fine-Chemicals: Technical and Economic Analysis","volume":"521","author":"Locaputo","year":"2025","journal-title":"Chem. Eng. J."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1016\/j.renene.2015.12.049","article-title":"Efficient Solvent-Less Separation of Lipids from Municipal Wet Sewage Scum and Their Sustainable Conversion into Biodiesel","volume":"90","author":"Lopez","year":"2016","journal-title":"Renew. Energy"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"4004","DOI":"10.1039\/D5RA07550E","article-title":"Resource Utilization of Urban Sludge via Pyrolysis: Impacts on Cement Performance and Environmental Safety","volume":"16","author":"Hu","year":"2026","journal-title":"RSC Adv."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"619","DOI":"10.1007\/s13399-020-00616-1","article-title":"Residual Mexican Biomasses for Bioenergy and Fine Chemical Production: Correlation Between Composition and Specific Applications","volume":"11","author":"Pastore","year":"2021","journal-title":"Biomass Convers. Biorefin."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"122","DOI":"10.1016\/j.cattod.2012.02.006","article-title":"Catalytic Esterification of Fatty Acids Using Solid Acid Catalysts Generated from Biochar and Activated Carbon","volume":"190","author":"Kastner","year":"2012","journal-title":"Catal. Today"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"di Bitonto, L., Scelsi, E., Reynel-\u00c1vila, H.E., Mendoza-Castillo, D.I., Bonilla-Petriciolet, A., H\u00e1jek, M., Mustafa, A., and Pastore, C. (2024). A Closed-Loop Biorefinery Approach for the Valorization of Winery Waste: The Production of Iron-Sulfonated Magnetic Biochar Catalysts and 5-Hydroxymethyl Furfural from Grape Pomace and Stalks. Catalysts, 14.","DOI":"10.3390\/catal14030185"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"di Bitonto, L., Scelsi, E., Errico, M., Reynel-\u00c1vila, H.E., Mendoza-Castillo, D.I., Bonilla-Petriciolet, A., Corazza, M.L., Shigueyuki Kanda, L.R., H\u00e1jek, M., and Stateva, R.P. (2024). A Network of Processes for Biorefining Burdock Seeds and Roots. Molecules, 29.","DOI":"10.3390\/molecules29050937"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1007\/s42773-022-00194-7","article-title":"Use of Sewage Sludge Biochar as a Catalyst in Production of Biodiesel through Thermally Induced Transesterification","volume":"4","author":"Jung","year":"2022","journal-title":"Biochar"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.fuel.2011.09.030","article-title":"An Overview of the Organic and Inorganic Phase Composition of Biomass","volume":"94","author":"Vassilev","year":"2012","journal-title":"Fuel"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"141857","DOI":"10.1016\/j.scitotenv.2020.141857","article-title":"Survey of Elemental Composition in Dewatered Sludge in Japan","volume":"752","author":"Chen","year":"2021","journal-title":"Sci. Total Environ."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2349","DOI":"10.1007\/s10098-022-02339-5","article-title":"Flash Pyrolysis of Biomass: A Review of Recent Advances","volume":"24","author":"Ighalo","year":"2022","journal-title":"Clean Technol. Environ. Policy"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"141","DOI":"10.1007\/s10800-013-0616-4","article-title":"Electrosorption on Activated Biochar: Effect of Thermo-Chemical Activation Treatment on the Electric Double Layer Capacitance","volume":"44","author":"Dehkhoda","year":"2014","journal-title":"J. Appl. Electrochem."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"451","DOI":"10.1007\/s12649-016-9823-7","article-title":"Production and Characterization of Sewage-Sludge Based Activated Carbons Under Different Post-Activation Conditions","volume":"9","author":"Aliakbari","year":"2018","journal-title":"Waste Biomass Valorization"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"7465","DOI":"10.1007\/s43615-025-00580-w","article-title":"Advanced Characterization of Biochars Produced from Three Different Organic-Based Feedstocks and Their Potential Applications","volume":"5","author":"Kritikaki","year":"2025","journal-title":"Circ. Econ. Sustain."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"D\u2019\u00c1vila, M.L., Lustosa Filho, J.F., Martins, \u00c9.d.S., Marchi, G., Trindade, G., Costa, C.R., dos Santos, M.G.B., Sandri, D., and de Figueiredo, C.C. (2026). Co-Pyrolysis of Sewage Sludge and Zeolitic Basalt: Physicochemical Characterization, Stability and Carbon Sequestration Potential. Sustainability, 18.","DOI":"10.3390\/su18010258"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"70","DOI":"10.1016\/j.psep.2017.11.006","article-title":"Mineral Additive Enhanced Carbon Retention and Stabilization in Sewage Sludge-Derived Biochar","volume":"115","author":"Ren","year":"2018","journal-title":"Process Saf. Environ. Prot."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"6677","DOI":"10.1039\/D5NA00522A","article-title":"Fourier Transform Infrared Spectroscopic Technique for Analysis of Inorganic Materials: A Review","volume":"7","author":"Kawsar","year":"2025","journal-title":"Nanoscale Adv."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"24502","DOI":"10.1021\/acsomega.5c00963","article-title":"Combustion Behavior of Sewage Sludge Hydrochar Obtained in Fast Hydrothermal Carbonization","volume":"10","author":"Constantino","year":"2025","journal-title":"ACS Omega"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"21045","DOI":"10.1007\/s13399-025-06680-9","article-title":"Slow-Pyrolysis of Municipal Sewage Sludge: Biochar Characteristics and Advanced Thermodynamics","volume":"15","author":"Vali","year":"2025","journal-title":"Biomass Convers. Biorefin."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"390","DOI":"10.1016\/j.jcis.2021.02.133","article-title":"A Novel Activation-Hydrochar via Hydrothermal Carbonization and KOH Activation of Sewage Sludge and Coconut Shell for Biomass Wastes: Preparation, Characterization and Adsorption Properties","volume":"593","author":"Tu","year":"2021","journal-title":"J. Colloid Interface Sci."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"340","DOI":"10.1016\/j.jes.2020.08.005","article-title":"Effects of Chemical Modification on Physicochemical Properties and Adsorption Behavior of Sludge-Based Activated Carbon","volume":"100","author":"Wu","year":"2021","journal-title":"J. Environ. Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"101216","DOI":"10.1016\/j.scp.2023.101216","article-title":"Design Approach for the Sustainable Synthesis of Sulfonated Biomass-Derived Hydrochars and Pyrochars for the Production of 5-(Hydroxymethyl)Furfural","volume":"35","author":"Licursi","year":"2023","journal-title":"Sustain. Chem. Pharm."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1016\/j.cattod.2018.02.034","article-title":"Sulfonated Biochar as Acid Catalyst for Sugar Hydrolysis and Dehydration","volume":"314","author":"Xiong","year":"2018","journal-title":"Catal. Today"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Zaki, M.I., Hasan, M.A., Al-Sagheer, F.A., and Pasupulety, L. (2001). In Situ FTIR Spectra of Pyridine Adsorbed on SiO2-Al2O3, TiO2, ZrO2 and CeO2: General Considerations for the Identification of Acid Sites on Surfaces of Finely Divided Metal Oxides, Elsevier.","DOI":"10.1016\/S0927-7757(01)00690-2"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1007\/s12155-026-10970-z","article-title":"Cerium\u2013Impregnated Rice Husk\u2013Derived Catalysts for Fatty Acid Esterification Using Methyl Acetate","volume":"19","author":"Albarello","year":"2026","journal-title":"Bioenergy Res."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"107178","DOI":"10.1016\/j.fuproc.2022.107178","article-title":"Phosphotungstic Acid Functionalized Biochar for Furfural Production from Corncob","volume":"229","author":"Li","year":"2022","journal-title":"Fuel Process. Technol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"132279","DOI":"10.1016\/j.cej.2021.132279","article-title":"Sulfated Complex Metal Oxides Solid Acids with Dual Br\u00f8nsted-Lewis Acidic Property for Production of 5-Ethoxymethylfurfural from Biomass-Derived Carbohydrates","volume":"429","author":"He","year":"2022","journal-title":"Chem. Eng. J."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"156648","DOI":"10.1016\/j.cej.2024.156648","article-title":"Catalytic Hydrogenation of Waste-Derived Lipids: A Route to Producing Sustainable Drop-in Biofuels by Using Re\/TiO2 Catalysts","volume":"499","author":"Roberto","year":"2024","journal-title":"Chem. Eng. J."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"S62","DOI":"10.1016\/j.biortech.2009.03.035","article-title":"Esterification of Free Fatty Acids Using Water-Tolerable Amberlyst as a Heterogeneous Catalyst","volume":"101","author":"Park","year":"2010","journal-title":"Bioresour. Technol."},{"key":"ref_37","unstructured":"Publications Office of the European Union (2024). Directive (EU) 2024\/3019 of the European Parliament and of the Council of 27 November 2024 Concerning Urban Wastewater Treatment (Recast) (Text with EEA Relevance), Publications Office of the European Union."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"121154","DOI":"10.1016\/j.enconman.2026.121154","article-title":"Energy, Exergy and Mass Balances of a Biomass Pyrolysis Pilot Plant","volume":"353","author":"Lete","year":"2026","journal-title":"Energy Convers. Manag."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Anneken, D.J., Both, S., Kersters, R., Schmidt, G., and Reglitz, H.W. (2006). Fatty Acids. Ullmann\u2019s Encyclopedia of Industrial Chemistry, John Wiley & Sons.","DOI":"10.1002\/14356007.a10_245.pub2"},{"key":"ref_40","unstructured":"Lide, D.R. (2004). CRC Handbook of Chemistry and Physics, CRC Press. [85th ed.]."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"106810","DOI":"10.1016\/j.biombioe.2023.106810","article-title":"Production of Biocrude Oils from Various Bio-Feedstocks through Hydrothermal Liquefaction: Comparison of Batch and Continuous-Flow Operations","volume":"173","author":"Wang","year":"2023","journal-title":"Biomass Bioenergy"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"10048","DOI":"10.1021\/acssuschemeng.1c03651","article-title":"Pyrolysis Solves the Issue of Organic Contaminants in Sewage Sludge While Retaining Carbon\u2014Making the Case for Sewage Sludge Treatment via Pyrolysis","volume":"9","author":"Buss","year":"2021","journal-title":"ACS Sustain. Chem. Eng."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"119964","DOI":"10.1016\/j.jenvman.2023.119964","article-title":"Ensuring Safety Standards in Sewage Sludge-Derived Biochar: Impact of Pyrolysis Process Temperature and Carrier Gas on Micropollutant Removal","volume":"352","author":"Schlederer","year":"2024","journal-title":"J. Environ. Manag."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"109058","DOI":"10.1016\/j.jece.2022.109058","article-title":"Effect of Hemicellulose Extraction Pretreatment on Sulfonated Corncob Biochar for Catalytic Biodiesel Production","volume":"11","author":"Cao","year":"2023","journal-title":"J. Environ. Chem. Eng."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"101355","DOI":"10.1016\/j.eti.2021.101355","article-title":"Potato Peel Waste-Derived Carbon-Based Solid Acid for the Esterification of Oleic Acid to Biodiesel","volume":"21","author":"Hussein","year":"2021","journal-title":"Environ. Technol. Innov."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"109419","DOI":"10.1016\/j.cep.2023.109419","article-title":"Application of Sulfonated Biochar-Based Magnetic Catalyst for Biodiesel Production: Sensitivity Analysis and Process Optimization","volume":"190","author":"Saidi","year":"2023","journal-title":"Chem. Eng. Process.-Process Intensif."},{"key":"ref_47","first-page":"81","article-title":"Adsorptive Removal of Odour Substances and NO and Catalytic Esterification Using Empty Fruit Bunch Derived Biochar","volume":"28","author":"Park","year":"2018","journal-title":"Carbon Lett."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"050005","DOI":"10.1063\/1.4938341","article-title":"Reaction Kinetics of Free Fatty Acids Esterification in Palm Fatty Acid Distillate Using Coconut Shell Biochar Sulfonated Catalyst","volume":"1699","author":"Hidayat","year":"2015","journal-title":"AIP Conf. Proc."},{"key":"ref_49","first-page":"1039","article-title":"One-Step Synthesis of Peanut Shell-Derived Solid Acid for Biodiesel Production","volume":"37","author":"Shang","year":"2015","journal-title":"Energy Sources Part A Recovery Util. Environ. Eff."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"1704","DOI":"10.1039\/D2GC04747K","article-title":"The E Factor at 30: A Passion for Pollution Prevention","volume":"25","author":"Sheldon","year":"2023","journal-title":"Green Chem."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"126034","DOI":"10.1016\/j.renene.2026.126034","article-title":"Bio-Ethanol Dehydrogenation to Acetaldehyde over (NC)Li-Al Oxide Supported Copper Catalyst","volume":"272","author":"Vagunda","year":"2026","journal-title":"Renew. Energy"}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/31\/18\/3273\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T04:23:36Z","timestamp":1789619016000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/31\/18\/3273"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,15]]},"references-count":51,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["molecules31183273"],"URL":"https:\/\/doi.org\/10.3390\/molecules31183273","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,15]]}}}