Autor(es): Șen, Umut ; Rodrigues, João F.G. ; Almeida, Daiana ; Fernandes, Ângela ; Gonçalves, Margarida ; Martins, Marta ; Santos, Diogo M.F. ; Pereira, Helena
Data: 2024
Identificador Persistente: http://hdl.handle.net/10362/178642
Origem: Repositório Institucional da UNL
Assunto(s): activated carbon; biochar; electrochemical properties; kinetic analysis; nutshell; TBARS; Bioengineering; Chemical Engineering (miscellaneous); Process Chemistry and Technology
Funding Information: U. \u0218en acknowledges support from the Funda\u00E7\u00E3o para a Ci\u00EAncia e a Tecnologia (FCT, Portugal) through a research contract (DL 57/2016). The authors are grateful to the FCT for its financial support through national funds to CIMO (UIDB/00690/2020 (DOI: 10.54499/UIDB/00690/2020) and UIDP/00690/2020 (DOI: 10.54499/UIDP/00690/2020)), SusTEC (LA/P/0007/2020 (DOI: 10.54499/LA/P/0007/2020)), and CEF (UIDB/00239/2020 and UIDP/00239/2020 (DOI: 10.54499/UIDB/00239/2020 and DOI: 10.54499/UIDP/00239/2020)). The contract of \u00C2. Fernandes (DOI: 10.54499/CEECINST/00016/2018/CP1505/CT0008) was funded by the FCT through the institutional scientific employment program. FCT is also acknowledged for funding a research contract in the scope of programmatic funding UIDP/04540/2020 (D.M.F.S.). Publisher Copyright: © 2024 by the authors.
Pine nutshells (PNSs) are lignocellulosic waste materials with limited use in domestic heating. However, a biorefinery approach may be applied to fractionate PNSs and produce chemicals, materials, and improved solid fuels. In this study, we fractionated PNSs and produced antioxidant extracts, lignins, polysaccharides, chars, and activated carbons and analyzed their potential applications. Pyrolytic kinetic modeling as an alternative method to chemical fractionation was also tested. The results showed that the PNS contains low amounts of extracts with weak thiobarbituric acid reactive substances (TBARS) antioxidant properties, while its lignin content is remarkable (50.5%). Pyrolytic kinetic modeling was comparable to wet chemical analysis for estimating lignin yield. Moderate-temperature pyrolysis of the PNS resulted in a 23% char yield. The PNS chars showed improved fuel characteristics, retained 36% water, and leached 151 mg/L potassium into the water. The steam activation of PNS biochars at 750 °C resulted in oxygen-enriched activated carbons with specific surface areas up to 467 m2/g. The overall results indicate promising biochar applications of the PNS for soil amendment and supercapacitor uses.
