Lignin-First Integrated Steam Explosion Process for Green Wood Adhesive Application

Abstract

Steam explosion (SE) is one of the most advanced pretreatment processes currently used for the production of biofuel from lignocellulose. However, steam explosion lignin is generally recovered as a secondary impure co-product, mainly used for energy production. In this work, beech wood sawdust was first exploded at 180°C or 200°C during 5 min after water or dilute acid impregnation. The recovery of lignin from exploded wood was studied using an alkali process at 80°C or an ethanol-organosolv process at 200°C. The impact of the SE parameters and of the delignification step on the lignin structure was examined by size exclusion and ionic chromatography (SEC), 31 P and HSQC NMR spectroscopies. The different lignin 2 fractions have been evaluated for the production of adhesive without addition of any synthetic resin, composed of 50% glyoxalated lignin and 50% tannins. It was demonstrated by thermomechanical analysis (TMA) that the parameters of the process greatly impact the performance of the resulting resin. SE lignin produced from acid SE (a-SE) treatment at 200°C followed by an alkaline delignification led to an adhesive formulation displaying a very good performance with MOE max ≈ 6000 MPa.

Novel Bionic Soy Protein-Based Adhesive with Excellent Prepressing Adhesion, Flame Retardancy, and Mildew Resistance

“…Biobased wood adhesives containing biochemical components, such as starch, protein, , lignin, , and tannins, , have received increasing attention in applications related to wood-based products and panels due to their superior biocompatibility and eco-friendliness. − Among them, soy protein (SP) adhesives have been widely studied and considered as potential candidates to replace traditional aldehyde-based adhesives for plywood production due to their low cost and being rich in chemically active functional groups. , However, the application of SP-based adhesives is often hampered by poor water resistance and inadequate bonding strength . As a result, numerous methods have been developed to solve these problems, including chemical cross-linking, , physical blending, enzymatic treatment, , and bionic design. , …”

“…Biobased wood adhesives containing biochemical components, such as starch, 1 protein, 2,3 lignin, 4,5 and tannins, 6,7 have received increasing attention in applications related to woodbased products and panels due to their superior biocompatibility and eco-friendliness. 8−10 Among them, soy protein (SP) adhesives have been widely studied and considered as potential candidates to replace traditional aldehyde-based adhesives for plywood production due to their low cost and being rich in chemically active functional groups.…”

Optimization of the Hot-Pressing Regime in the Production of Eco-Friendly Fibreboards Bonded with Hydrolysis Lignin

“…The use of natural, bio-based adhesives as partial or complete substitutes of the traditional thermosetting resins is a perspective approach to achieve this goal [21][22][23][24][25][26][27][28][29]. The use of natural binders has another environmental effect, namely the utilization of residual natural resources from other industries [30][31][32][33][34][35][36][37][38][39].…”

Flame-retardant lignin-containing micro/nano fibrillated cellulose by steam explosion: preparation and comparative study

“…The cellulose, hemicellulose, other various sugars and lignin contents of the biomass was obtained according to our previous reports (He et al, 2020;Moussa et al, 2020).…”