Preparation of Solid Fuel Hydrochar over Hydrothermal Carbonization of Red Jujube Branch

Abstract

Biomass energy is becoming increasingly important, owing to the decreasing supply of fossil fuels and growing environmental problems. Hydrothermal carbonization (HTC) is a promising technology for producing solid biofuels from agricultural and forestry residues because of its lower fossil-fuel consumption. In this study, HTC was used to upgrade red jujube branch (RJB) to prepare hydrochar at six temperatures (220, 240, 260, 280, 300, and 320 °C) for 120 min, and at 300 °C for 30, 60, 90, and 120 min. The results showed that the energy recovery efficiency (ERE) reached maximum values of 80.42% and 79.86% at a residence time of 90 min and a reaction temperature of 220 °C, respectively. X-ray diffraction results and Fourier transform infrared spectroscopy measurements show that the microcrystal features of RJB were destroyed, whereas the hydrochar contained an amorphous structure and mainly lignin fractions at increased temperatures. Thermogravimetric analysis shows that the hydrochar had better fuel qualities than RJB, making hydrochar easier to burn.

Comparative study of pomelo‐peel‐derived hydrochar and torrefied poultry‐litter on coal fuel blends: Combustibility, synergy factor, and ash analysis

“…Compared with the initial feedstock, the HHV of PPHC increased by 32%-46%, indicating that HTC is an effective method for producing solid fuels with high energy density. 31,33,34 The HHV of PLBC was much lower than that of PPHC, ranging between 15.5 and 18.8 MJ kg -1 . This was comparable with the values reported in a previous study, where an HHV value of 18.9 MJ kg -1 was obtained from poultry litter torrefied at 300 °C.…”

Conversion of Slaughterhouse Wastes to Solid Fuel Using Hydrothermal Carbonization

“…Hydrothermal carbonization (HTC) is a thermochemical reaction-based method which occurs in a relatively low temperature range (150-300 • C) with moisture and autogenous pressure [9,10]. The relatively low energy input and mild treatment conditions of HTC have caused it to receive attention as an alternative biomass treatment technology rather than conventional thermal treatment technologies (e.g., pyrolysis, combustion) [11,12]. During the HTC reaction, various types of organic matter are converted into a valuable carbon-rich material (i.e., hydrochar).…”

“…For the above reason, considerable studies on HTC reactions for hydrochar production and its use as a solid fuel have gained significant interest in this research area. Li et al and Roy et al reported on potential routes for solid fuel production using hydrochar derived from red jujube branch and peat moss, respectively [12,17]. Not only experimental research but also process efficiency modeling and cost analysis studies on HTC reactions have been published.…”

Effects of process parameters on the physicochemical properties of corn stalk hydrochar and the removal of alkali and alkaline earth metals

“…In recent years, researchers have conducted extensive studies on different lignocellulosic biomass types by HTC treatment, including glucose [12], cellulose [13], rice straw [14], edible cactus cladodes [15], water hyacinth [16], coconut and rice husks [6], red jujube branches [17], and waste eucalyptus barks [18], and so on. The hydrothermal operating conditions, including the reaction pressure [8], reaction temperature [9], residence time [9], reaction solution [19], solid/liquid ratio [15], mixing [20], catalyst (residual liquid of HTC, acid or alkali solutions) [21], and particle size [22], have various influences on the properties of the HTC products.…”