Effects of Parent Coal Properties on the Pyrolytic Char Chemical Structure: Insights from Micro-Raman Spectroscopy Based on 32 Kinds of Chinese Coals

The chemical structures of pyrolytic chars prepared from 32 kinds of Chinese coals were investigated with micro-Raman spectroscopy in this study. Both first-order and second-order Raman spectra of the chars were curve-fitted and analyzed. The effects of the parent coal properties, including coal rank, volatile, fixed carbon, and ash content, on the pyrolytic char structures were detailed discussed and the correlations between these coal properties and pyrolytic char chemical structures were set up. Multiple-factor analysis was done to propose a comprehensive coal property index that relates well to the pyrolytic char chemical structure. The results indicate that the aromatization degree is the key distinguishable structure of pyrolytic chars prepared from coals with various rank, and the alkyl C−H and aryl C−H structures have no significant difference. The aromatization degree of pyrolytic char decreases with the increase of coal rank, while it increases with the increase of the fixed carbon content in parent coals. The high content of moisture in parent coal can induce condensation of the pyrolytic char, but the inorganic composition probably prevents the condensation of the char. Limited correlations between the coal rank, fixed carbon, moisture and ash content, and the aromatization degree of pyrolytic chars were found. A comprehensive coal property index: (fixed carbon content + moisture content)/(volatile content + ash content) (in air dry basis) combining the coal properties together relates well to the aromatization degree of pyrolytic char and can act as a good indicator for the pyrolytic char chemical structure. This study reveals the effects of the parent coal properties, including coal rank, fixed carbon, moisture, and ash content, on the pyrolytic char chemical structure, and provides a new comprehensive coal property index to predict the pyrolytic char chemical structure.

Validated ensemble variable selection of laser-induced breakdown spectroscopy data for coal property analysis

Variable selection based on ensemble learning and validation for rapid and low-cost analysis of coal properties using laser-induced breakdown spectroscopy.

A Case Study on Coal Industry of Shanxi Province in China: Empirical Analyses of Holding Power of the Resource-Based Region-Leading Industry over Regional Employment

The paper made unary linear regression and structure deviation degree analyses with the data of Shanxi province in China from 1992 to 2010. The results show that when the coal output increases by 1% , the employment will increase by 1.202%. And the structure deviation degree in the coal industry fell from-0.11 to-0.56 between 1992 and 2001, then it aggrandized to - 0.15 in 2010. Which presented a note of discord surfaced during industrial structure and employment structure adjusting in Shanxi province. This suggests that there are the disguised unemployment within the coal industry. So this paper emphasizes that the government should implement the coal property right reform policy, and simultaneously develop effective measures to guide the workers to flow from the coal industry to the other secondary industries or the third industry.

Effect of Coal Property and Ratio of Acid to Coal on Ion Exchange Performance of Sulfonated Coal

There are more advantage for Sulfonated coal such as lower price, materials widely, and stronger ion exchange performance. Sulfonated coal were prepared by huolinhe brown coal and shanxi anthracite as raw material, and the effect of coal quality, ratio of acid to coal on the ion exchange properties of sulfonated coal were studied. Results show that the brown coal is more advantageous to sulfonation reaction, the temperature is 120, sulfonated time is 9 h, and ratio of acid to coal is 5:1. Under the conditions, the ion exchange property of sulfonated coal is best.

Experimental Study on the Pollutants Release Characteristics During Combustion of Lean Coal with Different Coal Rank

In this paper, the characteristics of SO2 and NO release during combustion of lean coal with different coal rank were experimentally studied in the one-dimensional furnace for pulverized coal combustion. The results showed: The coal property and proportion of the component coals have great influence on the characteristics of SO2 and NO release. The releasing concentration of SO2 and NO distributing along the furnace height is generally between that of component coals, and the releasing characteristics of SO2 and NO would be more near to that of the larger proportion coal. The measuring value of the formation concentration of SO2 and NO are different from the calculating value based on the weighted means of the component coals to a certain extent. While the different coal are added to lean coal, the time corresponding with peak value releasing concentration of SO2 and NO is different.