Document Type

Journal Article

Publication Date

2024

Keywords

vacuum pressure swing adsorption, coal mine methane, carbon molecular sieves, oxygen removal

DOI

10.1109/EEE59956.2024.10709703

Abstract

The aim of this study was to develop a safe, efficient and environmentally friendly method for the treatment of coal mine methane (CMM) in order to achieve its efficient utilisation as an energy source while reducing the safety risks and environmental issues associated with it. Oxygen removal from a model CMM, which contained about 37 % CH4 and the balance air, was carried out by vacuum pressure swing adsorption (VPSA). Two commercial carbon molecular sieves, CMS1 and CMS2, were used as adsorbents, in which CMS1 has higher selectivities of O2/N2 and O2/CH4. To ensure the safety of the oxygen removal process, a rinse step with N2 as rinse gas followed by the adsorption step was introduced. With the rinse step, the oxygen could be safely and effectively separated from CMM. Combining the advantages of both CMS1 and CMS2, a layered VPSA was proposed. Under the operating condition of the feedstock gas flow rate 750 cm3/min, the adsorption time 120 s, the rinse time 40 s and the rinse pressure 0.43 MPa (abs.), a product gas with over 50 % CH4 and less than 0.5 % O2, an off-gas with CH4 below 3 %, and a CH4 recovery of higher than 95 % were obtained. The results not only meet the objectives of this study, but also provide a viable technological solution for the safe utilisation of CMM and the reduction of greenhouse gas emissions.

Source Publication

2024 International Conference on Energy and Electrical Engineering (EEE)

ISBN

979-8-3503-4176-8

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