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Among many anthropogenic sources of greenhouse gases (GHG), landfill emissions, consisting of methane (CH4) and carbon dioxide (CO2), are one of the major contributors of anthropogenic GHG. In recent years, various innovative landfill biocovers have been investigated and developed to mitigate the emissions of methane (CH4) from municipal solid waste (MSW) landfills. However, the problem of CO2 emissions [which constitute about 40% of landfill gas (LFG)] from MSW landfills still remains unresolved. An innovative cover system which consists of basic oxygen furnace (BOF) slag with biochar amended soil is being developed to mitigate CH4 and CO2 emissions from landfills. The biochar amended soil is effective in mitigating CH4 emissions by microbial methane oxidation, while BOF slag could be effective in sequestering CO2 emissions by carbonation mechanisms. However, the properties of BOF slag vary based on several factors such as mineralogical composition of slag, particle size, moisture content, and temperature. In this study, CO2 sequestration potential of BOF slag was evaluated under synthetic LFG condition. The performance of the BOF slag in sequestering CO2 under different moisture condition was also examined. The results showed that BOF slag can sequester substantial amount of CO2 under LFG condition. The study also enlightened the importance of moisture for initiating carbonation reaction; however, the moisture alone was not the controlling parameter for CO2 sequestration. The mineralogy of the BOF slag plays an important role in determining CO2 sequestration capacity of the slag.
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Cold plasma-Metal Organic Framework (MOF)-177 breathable system for atmospheric remediation
Non-thermal plasma Methane capture Carbon dioxide capture Metal organic framework Methanol synthesis Atmospheric remediation 1. Introduction The stabilization of CO2 and CH4 concentrations in the air to control global warming is accelerating. There are continued efforts to develop and optimize different technologies for capture and sequestration of these greenhouse gases from industrial emission sites. From these gases, CH4 is the most dominant anthropogenic greenhouse gas (after CO2). Methane can react with nitrogen oxides leading to tropospheric ozone pollution and posses a higher global warming potential (GWP) than CO2. It is 84 times more potent than CO2 over the first 20 years after release and ~28 times more potent after a century. Methane concentrations could be restored to preindustrial levels by removing ~3.2 of the 5.3 Gt of CH4 currently in the atmosphere [1]. Rather than capturing and storing the methane, CH4 could be oxidized to CO2, through the ther- modynamically favorable reaction: CH4 + 2O2 → CO2 + 2H2O; ΔHrx = –803 kJ mol–1. With the possible production of valuable condensates such as form- aldehyde and methanol when employing different reaction conditions (i. e., gas ratio, oxidant type, temperature) and rational selected catalysts. The large activation barrier associated with splitting methane’s C– H * Corresponding author. E-mail address: Maria.CarreonGarciduenas@sdsmt.edu (M.L. Carreon). https://doi.org/10.1016/j.jcou.2021.101642 The direct capture of CO2 and CH4 from the atmosphere to stabilize the concentrations in the air to control global warming is accelerating. There are continued efforts to develop and optimize different technologies for capture and sequestration of these greenhouse gases from industrial emission sites. In this work we employed MOF-177 as an efficient CO2 and CH4 adsorbent at standard temperature and pressure conditions. We demonstrated the possibility of desorbing the gases under study when employing gentle plasma pulses of He. Moreover, we per- formed the synthesis of methanol from CH4 using O2 and CO2 as oxidants respectively in the presence of MOF- 177. We observed the highest conversion for the CH4 + O2 system when employing the MOF-177 at (5:1) (CH4: O2) flow ratio of 23.5 % and methanol selectivity of 17.65 %. While the best performance for the CH4 + CO2 system at the same conditions i.e., (5:1) (CH4: O2) flow ratio was 18.4 % for the methane conversion and 11.68 % for the selectivity towards methanol. We expect this preliminary understanding of the adsorption-reaction system under non-thermal plasma environment can lead to future atmospheric remediation technologies.
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- Award ID(s):
- 2203166
- PAR ID:
- 10337528
- Date Published:
- Journal Name:
- Journal of CO2 utilization
- ISSN:
- 2212-9820
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/https://doi.org/10.1016/j.jcou.2021.101642
