Structural, morphological, and thermal characterization of kraft lignin and its charcoals obtained at different heating rates

Autor(es)

Brazil, Tayra Rodrigues ^[1] ; Costa, Rogeria Nunes ^[1] ; Massi, Marcos ^{[1, 2]} ; Rezende, Mirabel Cerqueira ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo, Inst Sci & Technol, BR-12231280 Sao Jose Dos Campos, SP - Brazil

^[2] Univ Prebiteriana Mackenzie, Sch Engn PPGEMN, BR-01302907 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: MATERIALS RESEARCH EXPRESS; v. 5, n. 4 APR 2018.
• Citações Web of Science: 0

Resumo

Biomass is a renewable resource that is becoming more import due to environmental concerns and possible oil crisis. Thus, optimizing its use is a current challenge for many researchers. Lignin, which is a macromolecule with complex chemical structure, valuable physicochemical properties, and varied chemical composition, is available in large quantities in pulp and paper companies. The objective of this work is the physicochemical characterization of two Kraft lignin samples with different purities, and the study of its thermal conversion into charcoal. The lignin characterization was based on chemical, TGA, DSC, FT-IR, particle sizes, and FEG-SEM analyses. These analyses show that the lignins are mainly composed of guaiacyl and syringyl units, with residues of 30-36 wt.%, in inert atmosphere, depending on the lignin purity. From these results, the more purified lignin with higher carbon yield (%C) was selected for charcoal production. The heat treatment (HT) for carbonization of lignin, at different times (90, 180, and 420 min), resulted in different %C (41-44 wt.%). Longer HT resulted in higher %C and in charcoals with smaller pore sizes. Nanopores (similar to 50 nm) are observed for the charcoal obtained with the longest HT. (AU)

• Processo FAPESP: 14/12918-5 - Estudo da conversão de lignina Kraft em carvões com diferentes áreas superficiais
• Beneficiário: Tayra Rodrigues Brazil
• Modalidade de apoio: Bolsas no Brasil - Mestrado