# Structural Characteristics and Direct Liquefaction Performance of Macerals in Yili Coal from Xinjiang

## TL;DR

This study explores how different components of Yili coal behave during liquefaction, helping improve coal's efficient and high-value use.

## Contribution

The study introduces a new method to separate coal macerals and evaluates their liquefaction performance.

## Key findings

- YLV produces the highest yield of oil, asphaltene, and gas due to its active functional groups and chain structures.
- YLV's liquefaction oil has high alkanes and phenols from its aliphatic and phenolic content.
- YLI yields less product and has higher aromatics and ketones due to its aromatic and carbonyl carbon content.

## Abstract

Effectively separating and utilizing macerals based on their properties is crucial for the efficient and high-value utilization of coal. This study enhances the traditional screening method by employing primary and stepwise crushing techniques to separate Yili coal (YLC) into inertinite-rich (YLI) and vitrinite-rich (YLV) concentrates. The structural characteristics and direct coal liquefaction (DCL) performance of YLC, YLV and YLI are subsequently studied. The results indicate that YLV exhibits the highest yield of oil, asphaltene and gas, a finding closely linked to its elevated content of highly active functional groups and its long aliphatic and bridge chains. Furthermore, the liquefaction oil from YLV contains the highest content of alkanes and phenols, which is attributed to its high content of aliphatic hydrocarbons and phenolic hydroxyl groups. In contrast, YLI exhibits the lowest product yield relative to YLC and YLV, with the highest contents of aromatics, esters, and ketones in its oil, due to its high contents of aromatic and carbonyl carbon. The separation, structural characteristics and DCL studies of macerals from Yili coal offer valuable insights for the efficient separation and utilization of macerals.