Reaction kinetics of hydrothermal carbonization of loblolly pine

Hydrothermal carbonization of lignocellulosic biomass: Effect of process conditions on hydrochar properties

“…Reported residence times have thus ranged from days to a few hours [10,31] or even a few seconds [17,32]. Lynam et al [33] have previously investigated the significance of reaction temperature, retention time, solid load and particle size on hydrochar properties from Loblolly pine.…”

“…Thus far the majority of published academic literature on HTC of biomass for solid fuel production has concentrated on the carbonization of model compounds such as cellulose [15,16] along with virgin wood materials [17,18], herbaceous [19,20] and mixed feedstock [20][21][22] for clarifying carbonization mechanisms and hydrochar properties. Although dehydration, decarboxylation, polymerization and aromatization of biomass components during HTC are known to be mainly governed by reaction temperature, consistent reports on the effect and statistical significance of process conditions on hydrochar properties are still lacking.…”

Hydrothermal Carbonization: Modeling, Final Properties Design and Applications: A Review

“…For instance, Reza et al [10] studied the loblolly pine as feedstock material and proposed a kinetic model in which hemicellulose decomposes in a first-order reaction (E a = 29 kJ·mol −1 , A 0 = 58.6 × 10 5 s −1 ) producing aqueous chemicals and gases, while cellulose is also said to decompose by a first-order reaction (E a = 77 kJ·mol −1 , A 0 = 8.24 × 10 5 s −1 ), which produces a solid product, aqueous chemicals, and gases.…”

“…Several kinetic models have been developed that are comprised of a series of first-order reactions used to describe the HTC process [7,9,10,12,29] and ultimately used to predict HC properties (e.g., yield, carbon content). Calibration and determination of the kinetic constants in these models are based on experimental data associated with each individual study.…”

Evaluation of Integrated Anaerobic Digestion and Hydrothermal Carbonization for Bioenergy Production

“…Hydrothermal carbonization (HTC) is a thermochemical treatment process especially designed for wet feedstock, where biomass (with 80-90% water) is heated up to 200-260 °C at water saturation pressure and hold for 0.5-6 h (Figure 3) 7,8 .Subcritical water has the maximum ionic product at 200-260 °C, which means water under these conditions is reactive and behaves as a mild acid and a mild base simultaneously 9 . Hemicellulose, along with other extractives, degrade around 180-200 °C, while cellulose reacts around 220-230 °C, and lignin reacts at relatively higher temperature (>250 o C), but much slower than cellulose and hemicellulose 10 . Due to significant dehydration and decarboxylation, HTC results solid product named HTC biochar, with mass yield (dry HTC biochar/dry feed) of 40-80%, liquor containing carboxylic acids, furan derivatives, phenolic substances, and sugar monomers, and 5-10% CO 2 rich gaseous product .…”