Environmental and technical feasibility of cellulose nanocrystal manufacturing from sugarcane bagasse

Rosineide Miranda Leão; Patrícia Câmara Miléo; João M L L Maia; Sandra Maria Luz

doi:10.1016/j.carbpol.2017.07.087

Environmental and technical feasibility of cellulose nanocrystal manufacturing from sugarcane bagasse

Carbohydr Polym. 2017 Nov 1:175:518-529. doi: 10.1016/j.carbpol.2017.07.087. Epub 2017 Jul 31.

Authors

Rosineide Miranda Leão¹, Patrícia Câmara Miléo², João M L L Maia³, Sandra Maria Luz⁴

Affiliations

¹ Faculty at Gama, University of Brasília, Brasília, Brazil; Dept. of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, United States; Institute of Exact Sciences and Technology, Paulista University, Brasília, Brazil. Electronic address: rosemirandaleao@gmail.com.
² Engineering School of Lorena, University of São Paulo, Lorena, Brazil.
³ Dept. of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, United States.
⁴ Faculty at Gama, University of Brasília, Brasília, Brazil.

PMID: 28917896
DOI: 10.1016/j.carbpol.2017.07.087

Abstract

The environmental and technical feasibility of cellulose nanocrystal production from sugarcane bagasse fibers was evaluated. First, the life cycle assessment (LCA) is presented as a methodology to investigate the most feasible form of obtainment. The environmental impacts regarding climate change and water footprint were evaluated considering a gate-to-gate process and a functional unit of 1kg. The inventory data encompassed sugarcane plantation and pretreatment, bleaching and hydrolysis for bagasse generation. The twelve scenarios for extracting nanocrystals that were investigated consisted of treatment with sodium hydroxide or sodium chlorite followed by sulfuric acid hydrolysis. All products and processes were characterized by their yield and X-ray diffraction. As a result, all scenarios showed that the pretreatment stage was the most important contributor to the environmental impact. The comparison among the scenarios showed that nanocrystals produced by processes V - NaClO₂/NaOH/H₂SO₄/30min/1x and IX - NaClO₂/NaOH/HNO₃/H₂SO₄/30min/1x presented low water consumption and minimal contributions to climate change. Therefore, considering the LCA, yield and crystallinity, the best processes were V and IX sequences. Finally, these cellulose nanocrystals were evaluated by their chemical composition, morphology and thermal stability, exhibiting hemicellulose and lignin removal, nanometric dimensions from 8 to 12nm, high crystallinity and low thermal stability.

Keywords: Cellulose nanocrystals; Crystallinity; Life cycle assessment; Sugarcane bagasse; Thermal stability.