Evaluating the efficiency of the enhanced ultrasonic–assisted hydrogen peroxide degradation of low–rank coal biogenic gas

ABSTRACT

The efficiency of biogas formation from low-rank coal was improved through ultrasonic-assisted hydrogen peroxide degradation. We investigated various aspects of this process, including the mass of the small-molecule organic matter, changes in the composition of biogas components in three systems, and alterations in the microscopic morphology of coal before and after biogas formation. Our analytical methods included UV-vis spectrophotometry, drainage gas collection method, gas chromatography, infrared spectroscopy, and scanning electron microscopy. Optimal pretreatment conditions were identified with an ultrasonic power of 400 W, a reaction time of 90 min, and a reaction temperature of 60°C. The biogenic methanogenic cycle was delineated into three stages, with the raw coal and filtrate systems exhibiting fast and slow gas production stages during the first and second stages, respectively. In contrast, the residual coal system displayed slow and fast gas production stages during these stages. Methane yields were measured at 270.72 μmol g⁻¹ (raw coal), 303.50 μmol g⁻¹ (residual coal), and 293.43 μmol g⁻¹ (filtrate). Pretreated coal exhibited biomethane yields (residual coal and filtrate) approximately 120% higher than untreated raw coal. Notably, the gas-forming potential of the filtrate should not be underestimated. Ultrasonic-assisted hydrogen peroxide pretreatment disrupted the macromolecular reticulation structure within the raw coal, resulting in the opening of a portion of the aromatic ring structure. This innovative approach offers a novel strategy for augmenting biomethane production from low-rank coal and furnishes a scientific foundation for advancing industrial applications.

KEYWORDS:

• Low-rank coal
• biogenic gas
• ultrasonic
• hydrogen peroxide
• efficiency

Acknowledgements

The authors would like to thank the National Natural Science Foundation of China (41702174), Henan Province Key R&D and Promotion Special of China (222102320213, 212102210230), and Doctoral Fund of Henan Polytechnic University of China (No. B2021–74), for their support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The work was supported by the National Natural Science Foundation of China [41702174]; Henan Province Key R&D and Promotion Special of China [222102320213, 212102210230]; Doctoral Fund of Henan Polytechnic University of China [B2021–74]

Notes on contributors

Baihui Song

Baihui Song was born in Linyi, Shandong, China, in 1997. She received the B.S. degree and the M.S. degree in environmental science and engineering from Lvliang College, Shanxi, and Henan Polytechnic University, Henan, China, in 2020 and 2023, respectively. Her research interests include cleaner use of coal and ecological restoration of mining areas.

Li Wu

Li Wu received the Ph.D. degree in geological resources and geological engineering from Henan Polytechnic University, Henan, China, in 2019. In 2008, She became a Lecturer with the Department of Environmental Engineering, Henan Polytechnic University. Since 2013, she has been an Associate Professor with the School of Resources and Environment, Henan Polytechnic University. She has authored or coauthored more than 30 articles, and received 13 patents. Her research interests include cleaner use of coal and degradation of organic pollutants.

Huaizhen Li

Huaizhen Li received the Ph.D. in mining engineering from China University of Mining and Technology, Xuzhou, China, in 2018. In 2007, he became a Lecturer with the Department of Mining Engineering, Henan Polytechnic University. Since 2021, he has been an Associate Professor with the Institute of Safety Science and Engineering, Henan Polytechnic University. His research interests include mine pressure and rock formation control.

Xiaolin Li

Xiaolin Li received the B.S. degree in water engineering from North China University of Water Resources and Electric Power, Henan, China, in 2021. He is currently working toward the M.S. degree in environmental engineering from Henan Polytechnic University, Henan, China.

Mengyuan Lai

Mengyuan Lai received the B.S. degree in environmental engineering from Zhicheng College, Fujian, China, in 2022. She is currently working toward the M.S. degree in environmental engineering from Henan Polytechnic University, Henan, China.