Catalytic Effect of Metal Chlorides on Coal Pyrolysis Using TG & PY-GC/MS. Issue 11 (18th August 2022)

• Record Type: Journal Article
• Authors: Qiu, Qili; Pan, Danping; Zeng, Fan; Liu, Longlong; Qiu, Xiaolin
• Is Part Of: Combustion science and technology. Volume 194:Issue 11(2022)
• Page Start: 2255
• Page End: 2267
• Publication Date: 2022-08-18
• Subjects: Pyrolysis -- metal cations -- thermogravimetric -- kinetics -- tar distribution; Combustion -- Periodicals; Combustion engineering -- Periodicals; 541.36105
• DOI: 10.1080/00102202.2020.1863954
• Languages: English
• ISSNs: 0010-2202

Abstract

ABSTRACT: In this study, thermogravimetric analysis (TGA) with a final temperature of 1000°C at a heating rate of 10°C/min and rapid pyrolysis are used to analyze the catalytic pyrolysis effect of CaCl2 and NiCl2 on lignite samples, mainly including pyrolysis reaction analysis and tar product distribution. To avoid the influence of minerals on the pyrolysis reaction, acid-washed coal is selected and mixed with metal cations for further analysis. The TGA results show that when mixed with 6 wt. % Ca or Ni, the weight loss rate of acid-washed lignite increases from 46.46% to 59.76% and 54.66%, respectively. At pyrolysis temperatures above 600°C, the performance on coal pyrolysis transformation of Ca is significantly better than that of Ni. The effect of the catalyst on coal pyrolysis could be divided into three stages. Due to catalysis, the pyrolysis of the most unstable structure of coal is advanced to the first stage, which makes the second stage show a certain catalytic inhibition. Kinetic analysis reveals that the activation energy of pyrolysis is obviously reduced by catalysts, and comparatively, the most energy is needed at the second stage. The tar mainly contains substances with 5 to 16 carbon atoms, and aromatic hydrocarbons, as the main components, account for more than 90% of the tar composition. The yield of light aromatic compounds increases with the catalysts Ca and Ni, while the yield of polycyclic aromatics decreases.