Hydrothermal carbonization of rape straw: Effect of reaction parameters on hydrochar and migration of AAEMs

Hydrothermal Carbonization of Spent Coffee Grounds for Producing Solid Fuel

“…As illustrated in Figure 5, the yield of hydrochar continuously dropped when extending residence time from 30 min to 120 min, which is in a good agreement with the results reported by Cheng et al [29] where HTC of rape straw was carried out at 180 • C for 15-120 min. This trend could be caused by the stimulated decomposition of large biomolecules from biomass and then partition into liquid phase.…”

Increasing the energy density of high‐moisture wastes of beverage industry by hydrothermal pretreatment: Comparison of thermochemical conversion behaviors

“…Table 1 shows the higher heating value, proximate and ultimate analyses of GP, FS, and their corresponding hydrochars. Because hydrogen, oxygen, and carbon dioxide leave the structure through dehydration and decarboxylation reactions, mass loss was observed 38,39 . Dissolution of ash‐forming inorganic elements under hydrothermal conditions also contributed to mass loss 21 .…”

“…Because hydrogen, oxygen, and carbon dioxide leave the structure through dehydration and decarboxylation reactions, mass loss was observed. 38,39 Dissolution of ash-forming inorganic elements under hydrothermal conditions also contributed to mass loss. 21 In studies conducted with various biomass under different hydrothermal carbonization conditions, it was observed that most of the elements such as Ca, Na, Mg, K, which were found in the structure of hemicellulose and extractives, were removed from the structure under hydrothermal conditions.…”

Effect of hydrothermal carbonization temperature on fuel properties and combustion behavior of high-ash corn and rice straw hydrochar

“…When directly 2 used as a fuel, compared to traditional fossil fuels, biomass, especially crop straw, has many disadvantages like low energy density, high ash content and high moisture content. In addition, crop straw has a low bulk density, which will result in an increment in storage and transportation cost [5]. Moreover, high alkali metal content, alkaline earth metal content, and silicon content in crop straw biomass would contribute to slagging and fouling of heat transfer surfaces, reducing overall thermal efficiency when it was directly burned [6].…”

“…As an emerging indirect use method, hydrothermal carbonization technology, which is performed at mild reaction temperatures (180-260 o C) and pressure (autogenous pressure, 2-6 MPa) with water as the reaction medium, has been researched in many studies on the energy utilization of some lignocellulosic biomass, especially for low-ash crop straw [7,8]. HTC treatment could convert low-ash straw biomass into homogeneous, low-moisture and high-density solid fuel, with the ignition temperature and burnout temperature of hydrochar shifting to a higher temperature compared to the feedstock, and the chemical and combustion properties of the hydrochar are improved [9][10][11]. In some studies, it is found that the energy density of hydrochar, the solid product of HTC, is close to peat and lignite, and it could be used as clean fuel for direct combustion [12].…”