Generalized correlations for the aqueous liquefaction of lignocellulosics

Abstract

This paper shows that liquefaction (i.e. solubilization) of lignocellulosics in aqueous phase and in the absence of catalysts results in two general correlations. The extents of solubilization of both holocellulose and lignin are linearly related to overall conversion within the temperature range 150–270°C and up to conversions of 83%.

A review of wood thermal pretreatments to improve wood composite properties

“…The process in which hot water is used has been referred to as hot water extraction-HWE, also called autohydrolysis (Hsu et al 1988;Schwald et al 1988;Amidon et al 2008), hydrothermolysis (Bobleter and Bonn 1983;Bobleter et al 1991;Hörmeyer et al 1988;Hill 2006;Boonstra and Tjeerdsma 2006;Boonstra 2008;Agbor et al 2011), hot compressed water treatment (Kobayashi et al 2009;Xiao et al 2011), water hydrolysis (Harris 1952), wet torrefaction (Yan et al 2010), hydrothermal carbonization (Funke and Ziegler 2010;Falco et al 2011;Hoekman et al 2011;Libra et al 2011), aqueous fractionation, solvolysis or aquasolv (Agbor et al 2011), aqueous liquefaction (Heitz et al 1986), or cooking (Suchsland et al 1987;Weil et al 1998). This diversity of terms used to describe the same process could hinder comparison of properties of pretreated biomass under the effect of hot water.…”

Review on comparative study of dry and wet torrefaction

“…Wet torrefaction (WT) or hydrothermal carbonization (HTC) is another thermochemical conversion process on which wet lignocellulosic biomass is treated in a subcritical pressurized water vessel from 1 to 250 MPa at 180-265°C in an inert environment for a residence time of 5 min to several hours [18,71,72]. Another torrefaction method exists that uses hot water, which is referred to as the hot water extraction (HWE) method, auto-hydrolysis [73][74][75], hydro-thermolysis [76][77][78][79], hot compressed water treatment [71,80], water hydrolysis [81], WT (Yan et al, 2010) [82], hydrothermal carbonization [12,18,83], aqueous fractionation, solvolysis or aquasolv [76], aqueous liquefaction [84], or pressure cooking [85,86]. During WT, the hemicellulose contained in biomass is depolymerized through hydrolysis and converted into monomers and oligomers [87,88].…”

Improved Cellulose Yield in the Production of Dissolving Pulp from Bamboo Using Acetic Acid in Prehydrolysis

“…In the later stages of pre-hydrolysis, autoionization of acetic acid produced from acetyl groups provided additional hydronium ions that could improve the pre-hydrolysis kinetics (Heitz et al 1986). Based on the above mechanism, researchers considered how to add additional acetic acid to water during pretreatment to accelerate the hydrolysis.…”