scholarly journals Experimental and simulation studies on gasification characteristics of a low-rank coal by rapid heating under CO2-rich condition

Author(s):  
Wang Cong ◽  
Olalekan S. Alade ◽  
Kyuro Sasaki ◽  
Yuichi Sugai

In this investigation, an environmentally benign and efficient way for gasification of low-rank coal under CO2 rich condition, rapid heating, and high pressure was investigated. Series of experimental and simulation studies were carried out to compare the combustion characteristics of the Shandong (SD) low rank coal and Datong (DT) bituminous coal. It was found that the gasification potential of the SD coal sample was higher than that of the DT coal sample under the conditions investigated. A gasification model was developed and validated to predict the gasification characteristics of the low rank coal based on the experimental and the gasification kinetic parameters. It was found that the gasification conditions resulting in effective gasification of the low rank coal (in terms of CH4, CO and H2 gases production) are 100% CO2 concentration, 37.5 J/s heating rate, and 0.5 – 1 MPa pressure range.

2011 ◽  
Vol 383-390 ◽  
pp. 3011-3016 ◽  
Author(s):  
Jian Zhong Liu ◽  
Yu Jie Yu ◽  
Jun Hu Zhou ◽  
Chong Du ◽  
Lin Ye ◽  
...  

Shenmu coals as low rank coal are difficult to prepare for Coal Water Slurry (CWS). The maximum slurry concentration of Shenmu CWS is lower than 60%, which is not available for practical application. Coal blending is a simple operation and low cost method to improve the slurry ability of low rank coal. Two different kinds of anthracite and bituminous coal samples were blended in Shenmu coal to study the effect on the preparation of CWS, respectively. The results showed that the maximum solid concentration of CWS increased as the proportion of high rank coal rise. And the viscosity of CWS is dropped at the same concentration. Different coals blending have different effects on the elevation of slurry ability for Shenmu coal. The raw coal with best slurry ability is not always the most suitable for blending in low rank coal. HuanNan bituminous coal is the best choice for blending in Shenmu coal. The maximum solid concentration of CWS can be increased by 6% when the proportion of HuanNan coal reached to 70%.


Processes ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 500 ◽  
Author(s):  
Shen ◽  
Min ◽  
Liu ◽  
Xue ◽  
Zhu

Low-rank coal is difficult to upgrade using conventional flotation methods due to its high hydrophilic properties. Thus, it is necessary to explore new methods for upgrading and utilizing low-rank coal. In this investigation, a gaseous dodecane pretreatment method was used to enhance the flotation performance of low-rank coal. Pore distribution analysis, FTIR (Fourier Transform Infrared Spectroscopy), and contact angle measurements were used to study the surface properties of the coal sample. Size distribution and float-sink test results indicated that the coal sample contained a lot of clean coal with low ash content, which could be used as a high quality raw material for making coal water slurry. FTIR, pore distribution analysis, and contact angle results showed that the coal was very hydrophilic due to the high concentration of -OH group and the large number of pores and cracks on the coal surface. The hydrophobicity of the coal sample was significantly improved by the gaseous dodecane pretreatment method. Clean coal with 67.2% combustible matter recovery and 10.5% ash content was obtained by gaseous dodecane pretreatment flotation method. Coal water slurry with 60% concentration was prepared using the flotation clean coal.


Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Teng Li

The pore characteristics of the low-rank coal are different from medium- and high-rank coals. The low-temperature N2 adsorption (LP-N2A) measurements with a single low-rank coal were launched, and the dynamic change of pore structures under various pretreatment temperatures from 120°C to 300°C was studied. The isothermal curves of the DFS coal sample feature IV type, the hysteresis loops convert from H4 type to H2 type, and the hysteresis loops tend to be closed with the increased pretreatment temperatures. The mesopores are dominant in the DFS coal. The dynamic of pore volume (PV) and pore specific surface area (SSA) features the three-step-style change with the cut-off temperature points at 150°C and 240°C, and this has a relationship with the loss of the moisture and volatiles in the DFS coal sample. The pores with an aperture below 10 nm are the dominant mesopores in the DFS coal, and the mesopore volume features bimodal pattern distribution with a higher left peak of approximately 1.7 nm and a lower right peak of approximately 3-5 nm, and the right peak continuously right shift with the increase pretreatment temperatures. The total mesopore volume decreases with the upgrading temperatures, while the ratio of pores greater than 5 nm increases. Finally, the mesopore evolution model with the increased pretreatment temperatures was summarized.


2018 ◽  
Author(s):  
Jayeeta Chakraborty ◽  
◽  
Robert B. Finkelman ◽  
William H. Orem ◽  
Matthew S. Varonka ◽  
...  

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 239
Author(s):  
Wei Wang ◽  
Long Liang ◽  
Yaoli Peng ◽  
Maria Holuszko

Micro-Fourier transform infrared (micro-FTIR) spectroscopy was used to correlate the surface chemistry of low rank coal with hydrophobicity. Six square areas without mineral impurities on low rank coal surfaces were selected as testing areas. A specially-designed methodology was applied to conduct micro-FTIR measurements and contact angle tests on the same testing area. A series of semi-quantitative functional group ratios derived from micro-FTIR spectra were correlated with contact angles, and the determination coefficients of linear regression were calculated and compared in order to identify the structure of the functional group ratios. Finally, two semi-quantitative ratios composed of aliphatic carbon hydrogen, aromatic carbon hydrogen and two different types of carbonyl groups were proposed as indicators of low rank coal hydrophobicity. This work provided a rapid way to predict low rank coal hydrophobicity through its functional group composition and helped us understand the hydrophobicity heterogeneity of low rank coal from the perspective of its surface chemistry.


Energy ◽  
2021 ◽  
pp. 121505
Author(s):  
Muflih A. Adnan ◽  
Arif Hidayat ◽  
Mohammad M. Hossain ◽  
Oki Muraza
Keyword(s):  
Low Rank ◽  

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