Characteristics of Solid Residues Obtained from Hot-Compressed-Water Treatment of Woody Biomass

Abstract

Hydrolysis experiment of woody biomass in hot compressed water (HCW) was conducted in a batch-type reactor and the characteristics of solid residue after the HCW hydrolysis treatment were measured to understand the hydrolysis mechanism of woody biomass. Woody slurry of Douglas fir was used in this HCW experiment. Reaction temperature was controlled from 423 to 523 K, and the reaction time was set at 1 min. After separation of solid residues from the hydrolysis liquid material, the solid residue characteristics, such as proximate and ultimate analysis, particle size distribution, particle shape, surface area, pore size distribution, chemical composition, and equilibrium moisture content ratio, were measured and then the decomposition mechanism of woody biomass in HCW was discussed. It was found that the solid residue characteristics yielded in HCW changed drastically depending on the reaction temperature. For example, cellulose crystallinity decreased with increasing reaction temperature, and the physical characteristics of solid residue, such as particle shape, particle diameter, and pore size distribution, also changed dramatically depending on the reaction temperature. The physical or chemical characteristic change in HCW was strongly related to the decomposition of components of woody biomass at that reaction temperature. Dehydration of woody components was one of the most important factors to understand physical characteristics during HCW treatment.

Dietary Fiber Extraction from Defatted Corn Hull by Hot-Compressed Water

“…It was deduced that the macromolecules such as cellulose, hemicelluloses, lignin, and protein broke down into smaller molecules during the procedure treated by hot compressed water [Yuliansyah et al, 2010]. This result agreed with the report obtained from woody biomass, it was found that the solid residue characteristics obtained in HCW changed drastically depending on the reaction temperature [Kobayashi et al, 2009].…”

Extraction of Hemicellulosic Sugar and Acetic Acid from Different Wood Species with Pressurized Dilute Acid Pretreatment

“…Meanwhile, a lower solid recovery for 10% solid loading was determined after pretreatment under the same severities. As expected, owing to the enhanced effect on the removal of water-soluble components, the overall solubilization of woody biomass increased under harsher conditions, which is consistent with the trend reported in the literature (Kobayashi et al, 2009;Pérez et al, 2007). Fig.…”

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.…”

“…Wood subjected to HWE showed that important changes occur on the solid residue: particle shape and diameter, as well as pore size changed depending on the reaction temperature (Hietala et al 2002;Kobayashi et al 2009;Duarte et al 2011). The degree of crystallinity as well as liquid wetting and penetration is also increased proportionally to the increase of the severity factor ).…”