Comparative studies on the effect of mineral matter on physico-chemical properties, inherent moisture and drying kinetics of Chinese lignite

Drying behaviors of low-rank coal under negative pressure: Kinetics and model

“…The ranges of integration of z and P are r-R c and P 0 -P v , respectively. (18) where T is the water layer temperature (K), R is the equilibrium constant of the ideal gas reaction, M is the molar mass of a water molecule, and ε represents the porosity of the spherical surface of a wet ball, which is constant with the hypothesis of the radical ball model.…”

“…[13] Other research [14,15] has also observed the relation between the drying rate and the distribution and size of pores. Guo et al [16] attempted to define the drying as a process of water evaporation followed by vapor diffusion, neglecting the process of water migration, based on which a moisture evaporation process, and the Page model was proven to be suitable for modeling the drying process, [17] as was also concluded by Zhao et al [18] Another study by Zheng et al investigated the drying process of coal particles of different particle sizes under different temperatures using nitrogen as a carrier gas, developed an improved moisture condensation dynamics model, and further calculated the average activation energy of the water diffusion of coal particles of different sizes. [19] Recently, microwaves were reported to be an efficient method of LRC drying; the microwave method increased the drying rate, avoided the overheating of superficial particles and matched the Midilli-Kucuk model well.…”

Energy and water conservation at lignite-fired power plants using drying and water recovery technologies

“…Lignite could be pre-dried in various types of dryers [14], in which either boiler flue gas or steam extraction is used as the drying heat source. In recent years, some innovative drying methods, including WTA (Wirbelchicht-Trocknung mit integrierter Abwärmenutzung) [15], MTE (Mechanical Thermal Expression) [16], as well as drying dynamics [17], were studied and analyzed. The influence of external dryer on the efficiency of lignite-fired power plants was simulated [18,19] and theoretically analyzed [20,21] that pre-drying of lignite is an effective way to increase the power generation efficiency.…”

Effects of activated carbon on optimization of microwave irradiation upgrading of Loy Yang lignite

“…Lignite is an abundant low‐grade fossil fuel and has some advantages than high‐rank coal (e.g., easier access, lower cost, and lower mining cost) . Consequently, the assumption that lignite will be one of the main sources for both energy and chemical feedstock in the future is reasonable . However, lignite has a high water content, leading to higher transportation cost, greater energy requirement, spontaneous combustion risk, and so on .…”

“…[1][2][3][4] Consequently, the assumption that lignite will be one of the main sources for both energy and chemical feedstock in the future is reasonable. 5 However, lignite has a high water content, leading to higher transportation cost, greater energy requirement, spontaneous combustion risk, and so on. 2,6,7 Therefore, dewatering and upgrading of lignite are important for its widespread utilization in industry with a relatively environmentally friendly and efficient manner and are receiving considerable attention.…”