Abstract

The lignite at Mae Mo mine in Lampang Thailand, which is the focus of this study is ranked as the lowest class in coal classification. The lignite is currently burned directly in boilers for electricity production, resulting in inefficiencies. The objective is to use low-temperature pyrolysis to improve the lignite. Lab-scale experiments were conducted using different lignite particle sizes (2.36 mm, 1.00 mm, and 0.25 mm) at temperatures ranging from 250-600°C and retention times of 0-60 mins. The best quality lignite was achieved processing a particle size of 2.36 mm at a temperature of 350°C and a retention time of 20 mins. The gross calorific value, fixed carbon, and char content increased with higher operating temperatures. Weight loss occurred between 300-600°C due to the degradation of volatile organic fractions and char formation. Ash and sulfur constituents increased in smaller coal sizes. The average gross calorific value of char was 23.04-27.19 MJ/kg. Lower operating temperatures, larger coal sizes, and sufficient retention time are recommended for the pyrolysis process to achieve optimal results.

Full Text:

PDF

References

Clarke and M. C, “Low Rank Coal / Lignite Upgrading Technologies,” Energy Gener., no. December, pp. 50–52, 2013.

M. S. Ullah, U. Zahid, and T. Masood, “Ultimate and Proximate Analysis of Coal Samples from Different Regions in Pakistan for their Future Utilization,” J. Heterocycl., no. February 2020, pp. 39–41, 2019, doi: 10.33805/2639-6734.107.

Z. X. Zhao, B. W. Ma, S. Q. Zhu, and H. J. Zheng, “Low-temperature pyrolysis characteristics of Inner Mongolia lignite,” Adv. Mater. Res., vol. 805–806, pp. 1455–1460, 2013, doi: 10.4028/www.scientific.net/AMR.805-806.1455.

F. Nie, T. Meng, and Q. Zhang, “Pyrolysis of Low-Rank Coal: From Research to Practice,” Pyrolysis, no. November, 2017, doi: 10.5772/67498.

B. M. C. Clarke, “Low Rank Coal / Lignite Upgrading Technologies,” no. December, pp. 50–52, 2013.

X. Jin et al., “Coke formation on activated carbon during catalytic upgrading of coal pyrolysis volatiles,” Ranliao Huaxue Xuebao/Journal Fuel Chem. Technol., vol. 49, no. 5, pp. 609–616, 2021, doi: 10.1016/S1872-5813(21)60047-6.

D. Tokmurzin et al., “Pyrolysis characteristics of Kazakhstan coals in non-isothermal and isothermal conditions,” Int. J. Coal Prep. Util., vol. 00, no. 00, pp. 1–21, 2019, doi: 10.1080/19392699.2019.1594793.

S. Niu et al., “Investigation into the yields and characteristics of products from lignite low-temperature pyrolysis under CO 2 and N 2 atmospheres,” J. Anal. Appl. Pyrolysis, vol. 138, no. December 2018, pp. 161–169, 2019, doi: 10.1016/j.jaap.2018.12.020.

Y. Wang et al., “A study of char gasi fi cation in H 2 O and CO 2 mixtures : Role of inherent minerals in the coal,” Fuel Process. Technol., vol. 141, pp. 9–15, 2016, doi: 10.1016/j.fuproc.2015.06.001.

Y. Ren, J. Zheng, Z. Xu, Y. Zhang, and Z. Cao, “Effect of petcoke on the physical-chemical properties of lignite under microwave pyrolysis and its moisture re-adsorption capacity,” Fuel, vol. 250, no. March, pp. 1–7, 2019, doi: 10.1016/j.fuel.2019.03.090.

Y. Xu, Y. Zhang, G. Zhang, and Y. Guo, “Low temperature pyrolysates distribution and kinetics of Zhaotong lignite,” Energy Convers. Manag., vol. 114, pp. 11–19, 2016, doi: 10.1016/j.enconman.2016.02.004.

L. Qiang et al., “Research on the relationship between the structure and pyrolysis characteristics of pretreated Shendong coal,” Fuel, vol. 305, no. March, p. 121515, 2021, doi: 10.1016/j.fuel.2021.121515.

S. Liu et al., “Effect of a combined process on pyrolysis behavior of huolinhe lignite and its kinetic analysis,” Fuel, vol. 279, no. June, p. 118485, 2020, doi: 10.1016/j.fuel.2020.118485.

J. Yu, A. Tahmasebi, Y. Han, F. Yin, and X. Li, “A review on water in low rank coals: The existence, interaction with coal structure and effects on coal utilization,” Fuel Process. Technol., vol. 106, pp. 9–20, 2013, doi: 10.1016/j.fuproc.2012.09.051.

Y. Yu, J. Liu, R. Wang, J. Zhou, and K. Cen, “Effect of hydrothermal dewatering on the slurryability of brown coals,” Energy Convers. Manag., vol. 57, pp. 8–12, 2012, doi: 10.1016/j.enconman.2011.11.016.

X. Chu, W. Li, B. Li, and H. Chen, “Sulfur transfers from pyrolysis and gasification of direct liquefaction residue of Shenhua coal,” vol. 87, pp. 211–215, 2008, doi: 10.1016/j.fuel.2007.04.014.

D. Vamvuka and S. Sfakiotakis, “Combustion behaviour of biomass fuels and their blends with lignite,” Thermochim. Acta, vol. 526, no. 1–2, pp. 192–199, 2011, doi: 10.1016/j.tca.2011.09.021.

T. Li, “E ff ect of lignite as support precursor on deep desulfurization performance of semicoke supported zinc oxide sorbent in hot coal gas,” pp. 12780–12787, 2020, doi: 10.1039/c9ra10884j.

DOI: https://doi.org/10.46676/ij-fanres.v4i4.223

Refbacks

• There are currently no refbacks.

E-ISSN : 2722-4066

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.