MIL pretreatment on breaking hydrogen bond and swelling of coal: Experiment and simulation

Since direct combustion of low-rank coal is inefficient, expansion and dissolution are essential for better use of coal as an energy source. In this study, [C8mim]FeCl4 molecular configuration was synthesized by quantum chemical simulation method, and Magnetic ionic liquid (MIL) was used to modify coal to improve its swelling efficiency. The FT-IR and Raman properties of MIL were measured by simulation combined with practical methods. Dmol3 was used to study the hydrogen bond changes of coal molecules induced by MIL. When MIL interacts violently with organic matter in coal, the cross-linking network structure generated by non-covalent bonds is destroyed, resulting in the break of covalent bonds such as hydrogen bonds. Further experimental study shows that the pore structure and surface morphology of modified coal samples will be damaged, indicating that the MIL has the ability to dissolve hydrogen bonds and pretreat low-rank coal. It was found by TGA that MIL treatment can increase the tar yield of coal by up to 4.79% and reduce ash content by 3.51%. Through the integration of molecular modeling and experimental analysis, this study elucidates the fundamental principles underlying MIL pretreatment of coal, thereby providing a viable strategy for efficient quality improvement utilization of low-rank coal.

Automated summary

The molecular configuration of [C8mim]FeCl4 was synthesized using quantum chemical simulation, and Magnetic ionic liquid (MIL) was used to modify coal for improved swelling efficiency. MIL was found to disrupt weak interactions between coal molecules, leading to changes in pore structure and surface morphology, resulting in improved coal quality.