Premium
Flax nanofibrils production via supercritical carbon dioxide pre‐treatment and enzymatic hydrolysis
Author(s) -
Nlandu Hervé,
Belkacemi Khaled,
Chorfa Nasima,
Elkoun Said,
Robert Mathieu,
Hamoudi Safia
Publication year - 2020
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.23596
Subject(s) - xylanase , fourier transform infrared spectroscopy , enzymatic hydrolysis , cellulase , crystallinity , hydrolysis , scanning electron microscope , materials science , nuclear chemistry , chemistry , raw material , lignocellulosic biomass , supercritical carbon dioxide , chemical engineering , extraction (chemistry) , chromatography , organic chemistry , enzyme , composite material , engineering
Flax fibres are an agro‐industrial waste available in large quantities in several countries around the world. This resource can be properly used. The goal of this work was to extract lignocellulosic nanosized flax fibres using an environmentally friendly process based on a combination of supercritical carbon dioxide (SC‐CO 2 ) pre‐treatment and enzymatic hydrolysis. Raw flax fibres (RFF) were submitted to a SC‐CO 2 pre‐treatment at various temperatures (ie, 70°C and 80°C) and pressures (ie, 20 and 37.7 MPa) for 60 minutes. The enzymatic hydrolysis was performed at 40°C for 24 hours in a pH 4.0 buffer. Cellulase, xylanase, pectinase, and viscozyme were used as hydrolytic enzymes. The as‐received raw flax fibres, SC‐CO 2 pretreated flax fibres, and extracted lignocellulosic nanofibrils (LCNF) were characterized by Fourier transformed infrared spectroscopy (FTIR), x‐ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). It was shown that the effect of the SC‐CO 2 pre‐treatment of flax fibres was two‐fold. It helped to disorganize biomass without changing its chemical composition and it increased access to enzymes to extract LCNF. The FTIR analysis showed no changes in the functional groups after SC‐CO 2 pre‐treatment. The XRD characterization revealed that the crystallinity increased with the SC‐CO 2 pre‐treatment and LCNF extraction. SEM images showed holes, cracks, and erosion on the surface of the SC‐CO 2 pretreated flax fibres (SC‐CO 2 ‐PFF). TEM evidenced the production of nano/micro‐sized fibril and fibril aggregates.