Molecular characterization of biochar from five Brazilian agricultural residues obtained at different charring temperatures

Autor(es)

Schellekens, Judith ^[1] ; Silva, Carlos Alberto ^[2] ; Buurman, Peter ^[3] ; Rittl, Tatiana F. ^[4] ; Domingues, Rimena R. ^[2] ; Justi, Marina ^[2] ; Vidal-Torrado, Pablo ^[1] ; Trugilho, Paulo Fernando ^[5]

Afiliação do(s) autor(es)

^[1] Escola Super Agr Luiz de Queiroz ESALQ USP, Dept Ciencia Solo, Av Padua Dias 11, Piracicaba, SP - Brazil

^[2] Univ Fed Lavras UFLA, Dept Ciencia Solo, Av Dr Sylvio Menicucci 1001, Lavras, MG - Brazil

^[3] Wageningen Univ, Earth Syst Sci Grp, POB 47, NL-6700 AA Wageningen - Netherlands

^[4] Atmospher Environm Res IMK IFU, Inst Meteorol & Climate Res, Campus Alpin, Garmisch Partenkirchen - Germany

^[5] Univ Fed Lavras UFLA, Dept Ciencias Florestais, Av Dr Sylvia Menicucci 1001, Lavras, MG - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS; v. 130, p. 106-117, MAR 2018.
• Citações Web of Science: 2

Resumo

Important parameters that influence biochar properties include charring temperature and biomass type. We characterized the molecular properties of biochars from five agricultural residues with pyrolysis gas chromatography mass/spectrometry (pyrolysis-GC/MS) in comparison with atomic H/C and N/C ratios. Feedstocks included chicken manure, eucalyptus sawdust, coffee husk, sugarcane bagasse and pine bark. Biochars produced at three different temperatures (T-char) were analyzed, including 350, 450 and 750 degrees C, as well as the uncharred materials. The optimum temperature during analysis with pyrolysis-GC/MS (T-py) was examined. T-py 600 degrees C gave the best results for all T-char by showing a larger diversity of pyrolysis products compared to T-py 700 degrees C and 800 degrees C; T-py 600 degrees C was therefore used for qualitative and quantitative comparison of the samples. Charring temperature was the dominant factor that determined the chemical composition of the biochar pyrolysates. Uncharged feedstocks had the largest contribution from carbohydrates, lignin phenols and long chain n-alkanes, all of which rapidly decreased with charring; biochars produced at T-char 350 and 450 degrees C showed the largest contribution from phenols, mid-chain n-alkanes, benzofurans, indenes, biphenyls and PAHs, from which the benzofurans, indenes, biphenyls and PAHs were particular abundant in samples produced at T-char 450 degrees C; pyrolysates of biochars produced at T-char 750 degrees C were characterized by branched aliphatics, short chain n-alkanes/nalkenes and low molecular weight (LMW) benzenes. Factor analysis showed that the variation of products differed largely within some chemical groups. For the N-containing compounds, caffeine, C-16 alkylnitrile and diketopiperazines were associated with uncharred materials, benzonitriles and quinolines were associated with T-char 350-450 degrees C. Another part of the variation of N-containing compounds was associated with chicken manure, and to a lesser extend also coffee husk, independently of T-char. For all five agricultural residues, the highest chemical diversity was found for biochar produced at T-char 350 degrees C. As the charring temperature increased, the diversity of pyrolysis products diminished. (AU)

• Processo FAPESP: 15/10108-9 - Efeitos da aplicação de biocarvão sobre o estoque de carbono e fertilidade do solo em condições de laboratório e de campo sob clima tropical
• Beneficiário: Tatiana Francischinelli Rittl
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/03953-9 - Dinâmica da matéria orgânica em organossolos de turfeiras tropicais (Diamantina-MG, Brasil) - desenvolvimento de proxies moleculares para a reconstrução de mudanças paleoambientais
• Beneficiário: Judith Schellekens
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado