Analysis of tar and pyrolysis gas from low-rank coal pyrolysis assisted by apple branch.

Low-rank coal (LRC) pyrolysis assisted by biomass can realize the clean and efficient conversion utilization of LRC. The gas and tar characteristics obtained from co-pyrolysis of apple branch (AB) and LRC at different stages were studied with TG-FTIR and Py-GC/MS. It was found that the co-pyrolysis process could be divided into four stages, and the weight loss rate of AB+LRC was 24.03% in the second stage (194.60–404.63 °C), lower than the calculated value. However, the third stage (404.63–594.33 °C) weight loss rate was 13.33%, higher than the calculated value. The content of volatile products increased during co-pyrolysis, resulting in a higher total weight loss rate than the calculated value. There was a synergistic effect between AB and LRC. Aromatic hydrocarbon release intensity in co-pyrolysis products was significantly enhanced in the second and third stages, and it was stronger than that of pyrolysis alone; in contrast, the release intensity of gaseous products was weaker than that of pyrolysis alone. In co-pyrolysis tar, the content of monocyclic and bicyclic aromatic hydrocarbons was increased. The C_<10 component was 86.48%, higher than the calculated value of 12.68%. The proportion of aromatic hydrocarbons and phenols increased significantly compared with the calculated value. [ABSTRACT FROM AUTHOR]