— 2.1 Gas properties 2.1.1 Gas content. One of the factors affecting the energy release potential of coal is gas content. Gas content is the summation of free and adsorbed gas in coal and is recognized as …

 — This paper reports a combined experimental and numerical investigation on the impact of particle size on the MILD combustion characteristics of pulverised brown coal.

 — 2.2. Characteristics of the fuels. The studies have been carried out for two different types of the coal–water suspension. The first group of CWF has been prepared from the long flame coal of the Kuznetsk basin and the second from the brown coal of the Kansk–Achinsk basin Agroskin and Gleibman (1980).. The studies have been carried …

 — For the residual coal in the same goaf, which is regarded as a hybrid particle size of coal consisting of a variety of single granularity of coal, its oxygen consumption rate is the mass weighted ...

Jayaraman et al. [17] investigated the gasification rate of high ash Indian coal char of varying particle size in TGA using steam and CO2 ambience separately at the temperature range of 900e1000 C.

 — The results show that (i) the modeled results are matched reasonably well with the inversion permeability data, and thus, this model has been validated; and (ii) as volatile matter content increases, the initial permeability decreases exponentially, but the deformation coefficient basically grows in a linear trend.

 — The maximum mass fraction were obtained in tree leaves is between 4-4.75mm, cow dung manure 0.3-1.00mm, banana tree waste 4-4.75mm and for lignite …

 — A fully transient model for steam gasification of coal char with multiple reactions is formulated.. • The prominent effect of endothermic steam-gasification and Boudouard reactions, for higher particle size is identified. • The yield of hydrogen is strongly affected both by the coal char type and reactor temperature. •

 — This paper is Part II of the study of brown coal char structural changes during gasification. Firstly, German Lusatian brown coal was gasified in a laboratory‐scale fluidized bed reactor in CO 2 within a temperature range of 800–950 °C at atmospheric pressure. Then, physical structure properties were extensively evaluated by means of ...

 — Coal body is a typical dual-porosity structure, which is composed of coal matrix and fracture. 33 Guo et al 34 believed that the limit of particle size is the same as the size of coal matrix block, and they pointed out that although the large coal block looks complete, it can be regarded as the aggregation of the small coal matrix/particles.

 — Brown coal particles used in fluidized beds are classified into B particles according to Geldart's classification. However, particle properties, size, density and cohesiveness change with moisture content. Therefore, it is important to know the influence of moisture content on its fluidization characteristics.

 — The gasification kinetic modelling of two Victorian brown coal (Yallourn and Maddingley) chars and the validity for entrained flow gasification were investigated in this study.

 — The SST model and the standard k-e model were 243 further tested in modelling an isothermal gas-particle flow in three inclined rectan- 244 gular jets in crossflow ( Tian et al. 2011).

This paper reports a combined experimental and numerical investigation on the impact of particle size on the MILD combustion characteristics of pulverised brown coal. In particular, the work investigates the volatiles release and reactions from the coal particles with a vitiated co-flow and its impact on the formation and emission of CO, CO

 — The SST model and the standard k-e model were 243 further tested in modelling an isothermal gas-particle flow in three inclined rectan- 244 gular jets in …

 — Download Citation | Study on Fractal Characteristics of Particle Size Distribution Function for Modified-Brown Coal | Particle size distributions (PSDs) are often rendered as cumulative functions ...

 — Investigation of the dependence of the process of spontaneous combustion on the particle size of brown coal processing products. Viktor Kuznetsov 1,2, Yury Goryunov 1, Sergey Demenchuk 1, Olga Magdeeva 1, ... A mathematical model of spontaneous combustion of coal matter is developed. The model uses the spatial nonstationary heat …

 — Photographs of brown coal ignition in air-firing mode (top panel) and oxy-firing mode (bottom panel). The coal feeding rate was fixed at 0.5 g/min. Download : Download high-res image (124KB) Download : Download full-size image; Fig. 6. Measured brown coal ignition time at various oxygen concentration with fixed coal mass feeding rate of 0.5 g/min.

 — Research on coal particles, however, is not common; an exception is the report of Zhong et al. [10], who studied the effects of particle size on the strength …

Evolution of gas transport pattern with the variation of coal particle size: Kinetic model and experiments. Wei Zhao, Kai Wang, Yuanping Cheng, Shimin Liu, Long Fan. ... isothermal methane sorption and desorption experiments with different particle sizes were conducted to validate the model. Other sorption data from literature were also ...

 — The generated carbonized coal underwent further sieving per BSI 377:1990 standard to produce carbonized coal ash particles 25, 53, and 90 μm particle size. Experimental design

 — A computational fluid dynamics (CFD) model of a 375 MW brown-coal-fired furnace in the Latrobe Valley, Australia, has been developed using ANSYS CFX 12.0.

 — For the coal samples with medium particle size, according to the contribution fraction results of β, γ and 1 − β − γ, 3–6 mm Cheji hard coal and 3–6 mm soft coal are found to be controlled by the fracture flow with γ being 0.894 and 0.623, respectively.

 — Reduction of particle size and of oxygen partial pressure both render temperature-jump ignition less likely. Gas temperatures required for ignition of brown-coal particles are only 600–800 K, the larger particles igniting at lower temperatures; ignition times are typically 5 ms for a 20 μm particle and 50 ms for a 100 μm particle, and are ...

 — The relationships between parameters in these two models (D f and n) and PE are shown in Fig. 1.According to Fig. 1, compared with R-R model, fractal model shows better packing state and the PE can reach a maximum value at 88.45%.In addition, PE values of particle systems using fractal model are more stable than those of particle …

 — The calculations from the model are compared with experimental data reported in the literature on the steam-drying of ceramic spheres and water droplets. ... [1− exp (−2000W c 1.6)] For brown coal [32], the curve-fitting of experimental data leads to (11c) ... Influence of particle size on the drying behavior of coal. Download : Download ...

 — The coal input rate was 0.27 kg/s, and limestone was not introduced to examine the effect of fuel particle size. The calculation was conducted without the secondary air. The average particle size of the …

Cylindrical particle modelling in pulverized coal and biomass co-firing process ... The particle size distribution and turbulent particle dispersion are considered. The radiative heat transfer is modelled by the P1 method. ...

 — Preliminary TGA experiments indicated that diffusion restrictions exist for Morwell coal char above a size range of 75–90 μm. Therefore, a series of duplicate preparations and experiments were also performed using 38–53 μm char in order to determine the effect of particle size on gasification kinetics at small, narrow particle size …

Scholars [17], [24], [26] have also attempted to analyze this size effect using the effective diffusion coefficient D e = D/R 2 (1/s, where R is the coal particle radius or gas diffusion path). As listed in Table 1, the diffusion coefficient D increases with R, while D e decreases with R.For this reason, the coal particle size when D e tends to be stable is regarded as …