Thermal Behavior and Char Structure Evolution of Bituminous Coal Blends with Edible Fungi Residue during Co-Pyrolysis

Abstract

Co-pyrolysis of coal and lignocellulosic biomass has the potential to mitigate the emission of greenhouse gases from an energy supply. Successful application of this technology requires proper investigation on the influence of coal and lignocellulosic biomass mixing on thermal behavior and product characteristics. Therefore, in this study, thermal behavior of a kind of Chinese bituminous coal blended with edible fungi residue (EFR) was evaluated through nonisothermal thermogravimertic analysis. Raman spectroscopy and scanning electron microscopy with energy dispersive spectroscopy techniques were applied to determine the char structure evolution. The results revealed that the EFR promoted thermal decomposition of the bituminous coal and synergy effect on char yield was observed. The activation energy distribution calculated via an isoconversional method showed nonadditivity performance, which may be caused by the catalytic effects of alkali and alkaline earth metals and the char structure evolution. The Raman spectrum results indicated that the Raman intensity of the co-pyrolysis char increased with the EFR ratio, which can be due to the combined effect of the O-containing groups and nonproportional effects of alkali and alkaline earth metallic species. The area ratio of the G (graphite) band to all the bands (A G / A all ) and that of the valley between D (disordered) and G bands to the D band (A GR /A D and A (GR+VL+VR) /A D ) had been found useful in evaluating the evolution of the char structure. An increase in A G /A all seemed to suggest the increasing aromatization of the chars. The increase in A GR /A D and A (GR+VL+VR) /A D implied the generation of more smaller (3−5 rings) aromatic ring structures and the elimination of lager (no less than 6 rings) aromatic ring systems in the char samples as the EFR ratio increasing.

Thermal behavior and the evolution of char structure during co-pyrolysis of platanus wood blends with different rank coals from northern China

“…Therefore, the char samples produced at 20°C min À1 in pyrolysis experiments were applied to conduct the subsequent analysis in this study. For quantifying the performance of volatiles, the devolatilization index (D i ) was calculated [4,24]:…”

“…According to previous literatures, the deviations of experimental and theoretical weight loss for the blends (DW) can be employed to estimate the synergistic effects [4,32]:…”

“…Cothermochemical conversion of biomass and coal can solve these problems and utilize coal in a cleaner method [4,5]. As the fundamental and initial step of co-gasification and co-combustion, co-pyrolysis has significant effects on the performance of the further process.…”

“…As the fundamental and initial step of co-gasification and co-combustion, co-pyrolysis has significant effects on the performance of the further process. Furthermore, co-pyrolysis can also be considered as a single co-thermochemical conversion process to produce a variety of fuels and chemicals [4,6]. Therefore, it is meaningful to http conduct the research on the characteristics of biomass and coal in their co-pyrolysis process so as to design and operate co-thermochemical utilization system.…”

Structural transformation of nascent char during the fast pyrolysis of mallee wood and low-rank coals

“…FT-Raman spectroscopy is a technique that can detect changes in both crystalline and amorphous carbonaceous structures. In recent studies, it has been used to characterise the chemical structure of chars produced from biomass and low-rank coals during pyrolysis and gasification [6,[9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25].…”