# A Low-Viscosity Copper-Based Deep Eutectic Solvent for Carbon Monoxide Elimination at the Return Corner of Coal Mining Faces

## TL;DR

This study introduces a new low-viscosity copper-based deep eutectic solvent that effectively removes carbon monoxide at coal mining faces.

## Contribution

A novel ethanol-modified deep eutectic solvent system [Emim]Cl-CuCl-1.0E is proposed for efficient CO elimination at ambient conditions.

## Key findings

- The [Emim]Cl-CuCl-1.0E system showed optimal CO elimination performance at 298.15 K and atmospheric pressure.
- Ethanol enhances the activity of Cu(I) ions, improving CO absorption efficiency.
- The system's thermal stability and viscosity-temperature relationship were characterized for practical application.

## Abstract

To address the recurring issue of excessive carbon monoxide (CO) concentrations at the return corner of fully mechanized mining faces under goaf conditions, this study investigated the elimination of CO at ambient temperature and pressure using deep eutectic solvents (DESs). CO, a colorless, odorless, and highly toxic gas, is notoriously difficult to remove under conventional conditions. A series of DESs were prepared and screened, revealing that the ethanol-modified system [Emim]Cl-CuCl-1.0E exhibited optimal CO elimination performance under conditions of 298.15 K and atmospheric pressure. Further investigations measured the viscosity-temperature relationship and thermal stability of this system while systematically examining the effects of temperature, CO contact time, and storage duration on its elimination efficiency. Analysis by FTIR and Raman spectroscopy indicated that Cu(I) ions play a crucial role in the CO absorption process. The introduction of ethanol significantly enhanced the activity of the Cu(I) ions, thereby effectively improving the CO elimination capacity of the system. This study proposes a novel potential method for managing CO in goaf areas and provides an experimental foundation for the application of DESs in the field of gas purification.