Effect of structural evolution on the products distribution of cutinite concentrates from cutinitic liptobiolith. (1st February 2022)

• Record Type: Journal Article
• Authors: Du, Meili; Liu, Lei; Fan, Jinwen; Li, Gang; Cai, Yuchu; Liu, Jing
• Is Part Of: Fuel. Volume 309(2022)
• Publication Date: 2022-02-01
• Subjects: Cutinitic liptobiolith -- Cutinite -- Pyrolysates -- Structural evolution; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2021.122137
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: Cutinite had a higher proportion of aliphatics. The pyrolysates of different coal-rank cutinite presented a unique composition. The pyrolysates of cutinite were closely related to the structural evolution. Abstract: This study primarily investigated molecular structure evolution controls of cutinite on volatile formation during pyrolysis. Pyrolytic characteristics and volatiles of cutinite were in depth characterized using the techniques of combination TG-FTIR and Py-GC/MS. Then, 13 C NMR were employed to investigate thoroughly the molecular structure and bond structure of cutinite. The results demonstrated that cutinite L had less aromatics with longer aliphatic chains and abundant carboxylic acids or esters, while cutinite P contained larger average aromatic clusters with abundant side-chains and more aldehyde or ketone. The number of aliphatic side-chains increased, aromatic cluster enlarged and the aliphatic side-chains became shorter for cutinite during structure evolution. And cutinite P, with higher coal-rank, displayed higher thermal stability with the lower weight loss than cutinite L. TG-FTIR results indicated that the structure evolution had a remarkable influence on the release of volatiles (CO2, CO, CH4, HCOOH, C2 H4 and C6 H6 ). The temperature intervals and content for these volatile species verified the evolution in molecular structure of cutinite. Furthermore, the influence of final pyrolysis temperature and structure evolution on the release trends of condensable volatiles were discussed in the work. Results indicated that the distribution of condensable volatiles for cutinite were closely related to the final pyrolysis temperature and structure evolution. Pyrolysis at higher temperature was beneficial to generate the unsaturated aliphatic hydrocarbons, cycloalkanes and aromatics, but the content of alkane gradually decreased, especially for cutinite L with lower coal-rank. The structure evolution of cutinite on the distribution of volatile species exhibited a different variation trends.