The Hot Compressed Water Treatment of Solid Waste Material from the Sugar Industry for Valuable Chemical Production

Abstract

Sugarcane bagasse, the solid waste material produced in the sugar industry, was subjected to treatment in hot compressed water. The experiments were performed in a batch-type reactor containing slurry of 10 ml of water and 1.2 g of solids. The reactor was heated to temperatures ranging between 200 • C and 300 • C for reaction times of 3 to 30 min. The product was separated into liquid and solid fractions. Each fraction was analyzed to investigate the alteration of the main lignocellulosic polymers by hot compressed water. Results for the liquid fractions showed that increased temperatures and reaction times completely dissolved hemicellulose and cellulose in the water, leaving lignin in the solid product. During treatment, hemicellulose and cellulose gradually decomposed into simple sugars, which were then degraded and decomposed into furfural, 5-(hydroxymethyl)furfural (5-HMF) and organic acids. However, the yield of furans and some organic acids decreased and became undetectable at 300 • C and with increasing reaction time. The solid fraction was also characterized before and after treatment. Results showed that the hydrogen and oxygen content of the solids decreased with increased reaction conditions, due to dehydration and decarboxylation reactions. The reactions also increased the carbon content of the treatment products by 1.2-1.6 times that in the raw material, suggesting that the hot compressed water treatment of sugarcane bagasse can be considered for the provision of valuable chemicals for biofuel and high-carbon-content material (biochar).

Biochemical Compositional Analysis and Kinetic Modeling of Hydrothermal Carbonization of Australian Saltbush

“…Figure shows how hemicellulose is highly vulnerable to hydrothermal degradation. This is consistent with previous findings in the literature. ,, The full determination of monosaccharides allows for a more detailed and accurate depiction of noncellulosic polysaccharides in biomass than previous literature, which merely estimates the hemicellulose content from the sum of glucose and xylose amounts . The limitations of such estimation are made instantly clear upon the realization that in saltbush, xylose and glucose account for a mere 41% of total noncellulosic monosaccharides (Figure ).…”

“…17,20,49 The full determination of monosaccharides allows for a more detailed and accurate depiction of noncellulosic polysaccharides in biomass than previous literature, which merely estimates the hemicellulose content from the sum of glucose and xylose amounts. 26 The limitations of such estimation are made instantly clear upon the realization that in saltbush, xylose and glucose account for a mere 41% of total noncellulosic monosaccharides (Figure 3). Total hemicellulose declines dramatically after even brief exposure to mild HTC; after only 15 min at 200 °C, total hemicellulose content declined to just 12% of that of untreated saltbush.…”

“…As a result, the behavior of lignocellulose as it reacts within a naturalistic biomass environment is little understood. One study conducted on HTC of bagasse utilized compositional analysis to track the changes in lignocellulose content over time and temperature . Hemicellulose was found to be highly susceptible to degradation, completely disappearing after 10 min at 200 °C and just 3 min at 270 °C, while cellulose content declined to around 50% after 30 min at 200 °C and was almost completely degraded after 20 min at 270 °C.…”

“…One study conducted on HTC of bagasse utilized compositional analysis to track the changes in lignocellulose content over time and temperature. 26 Hemicellulose was found to be highly susceptible to degradation, completely disappearing after 10 min at 200 °C and just 3 min at 270 °C, while cellulose content declined to around 50% after 30 min at 200 °C and was almost completely degraded after 20 min at 270 °C. The compositional techniques utilized in this study were not able to discern the levels of lignin as separate from the hydrochar product nor were they able to determine the overall hemicellulose content, measuring just xylose and glucose levels.…”

Extracción de quitina calcárea empleando agua bajo condiciones subcríticas a partir de cefalotórax de camarón

“…En los trabajos descritos en la literatura, los autores concuerdan en que la temperatura, el tiempo de tratamiento, tamaño de partícula, cantidad de agua y configuración de reactor, afectan, y puede causar reacciones de hidrólisis, despolimerización, deshidratación, descarboxilación, alteración o degradación de componentes y mayor disponibilidad de productos. (Brunner, 2009); (Iryani et al, 2014;Lavoie, Capek-Menard, Gauvin, & Chornet, 2010).…”