The Technical Analysis on Upgrade and Coupling of Low-Quality Coal


Experimental study was conducted with regard to upgrading low-quality coal by low temperature pyrolysis technology and fluidization classification technology, which laid the theoretical foundation for research and development of low-quality coal upgrading process. Firstly, a pyrolysis pilot experiment of long-flame coal was performed and the optimum pyrolysis conditions were found. When the final pyrolysis temperature was 450?C and the residence time was 10 minutes, the content of semicoke volatile dry ash-free was about 22.89% and the content of semicoke ash was about 16.1%. More than 5% of the ash needs to be removed before entering the pyrolysis fluidized bed. Thus, classification tests were carried out to pick out the coal particles with the target size of 500 μm, using a gas-solid fluidized bed coal picker. It was found that the separating effect of coal particles was the most satisfactory when the inlet velocity at the bottom was 3.27 m/s. The percentage of particles with diameters less than 500 μm was as low as 28.7% in the coarse samples. Based on the test results, a novel process of low-quality coal upgrade and coupling was proposed, which realized the sorting, grading, drying and pyrolysis of low-quality coal through the multi-stage fluidized bed integrated process.

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Zhao, B. , Yao, Q. , Lu, S. , Wang, Q. and Lv, J. (2014) The Technical Analysis on Upgrade and Coupling of Low-Quality Coal. Energy and Power Engineering, 6, 467-472. doi: 10.4236/epe.2014.613039.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Li, Z., Yu, W., Yang, C. and Zhou, A.N. (2013) Actuality and Expectation on Upgrading Utilization of Low-Rank Coal. Mining & Processing Equipment, 41, 1-6.
[2] Gu, X.-Y. (2009) Study on the Upgrading Process of Low-Rank Coal by the Thermalmodification. Clean Coal Technology, 1, 89-92.
[3] Wang, J.-G. and Zhao, X.-H. (2012) Demonstration of Key Technologies for Clean and Efficient Utilization of Low-Rank Coal. Bulletin of the Chinese Academy of Sciences, 27, 382-388.
[4] Guan, J., He, D.-M. and Zhang, Q.-M. (2011) The Technology of Improving Lignite Quality through Pyrolysis and the Concept of Poly-Generation. Coal Chemical Industry, 39, 1-4.
[5] Qian, W. (2012) Experimental Study on Medium-Low Temperature Pyrolysis of Low Rank Bituminous Coal and Characterization of Pyrolysis—Derived Products. Ph.D. Thesis, China University of Mining and Technology, Beijing.

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