Toward the cottonization of hemp fibers by steam explosion – Part 1: defibration and morphological characterization

Abstract

Fine hemp fibers (cottonized hemp) were processed using steam explosion. The quantification of the defibration rate was performed by image processing. Based on this method, the hemp defibration was optimized using a response surface methodology based on three-variable central composite design for the production of elementary fibers with low variability. Optimal parameters for the steam processes were as follows: time = 4.1 min; temperature = 191℃. Biomass was impregnated with a solution of NaOH (8%) before treatment, leading to a defibration rate of 91.2%, which is producing ≈50% fibers with length <3 mm, in good agreement with the experimental data. Damaged fibers originating from the conjugated effect of steam explosion and alkali hydrolysis were also observed.

Toward the cottonization of hemp fibers by steam explosion. Flame-retardant fibers

“…As described in a previous publication (Sauvageon et al, 2018) steam explosion appeared to be an efficient process for the cottonization of hemp. It can be seen from Figure 3 Unexpectedly, in this work we demonstrated that in contrast to bleaching (removal of lignin) which did not significantly modify the thermal decomposition of the fibers, the cottonization process greatly increased the thermal stability of the resulting material (+25-30 °C).…”

“…The steam explosion of raw hemp technical fibers (RF) was performed according to a previously described method after a basic impregnation (NaOH, 8% w/w). The optimal parameters of our previous study (190°C, 4 min) were used to produced exploded fibers (EF) composed of ~ 90% of elementary fibers (Sauvageon et al, 2018). Bleaching treatments were performed starting from raw and exploded fibers (producing respectively BRF and BEF).…”

“…In a recent paper, we described the production of fine hemp fibers using a steam explosion (SE) process (Sauvageon et al, 2018). The optimization of the process parameters was done using a systematical approach and an image processing allowing the production of superior quality cottonized hemp fibers with low variability.…”

Industrial Ramie Growing on Reclaimed Ion-Adsorption Rare Earth Elements Mine Tailings in Southern China: Defibration and Fibers Quality

“…In a previous paper, we described the optimization of fine hemp fibers extraction using SE [4]. This method allowed an efficient degumming of the technical hemp fibers and the production of a cotton-like material.…”

Steam explosion pretreatment of willow grown on phytomanaged soils for bioethanol production

“…The effect of SE on biomass combines a chemical hydrolysis, a thermal effect during the steam treatment and a mechanical effect during the explosive decompression. SE induces (1) a partial breakdown of glucosidic and lignin-hemicelluloses linkages by hydrolysis and of intramolecular hydrogen bonds (2) a thermo-mechanical defibration due to the flash evaporation of water in the cell wall (Jacquet et al, 2015, Sauvageon et al, 2018. As a result, SE is described as an efficient way to decrease the particle size and to induce an extensive defibration of the biomass.…”