Dehydration and low temperature separation technologies for liquified natural gas production via electrolysis: A systematic review. (August 2020)

• Record Type: Journal Article
• Authors: Barelli, L.; Bidini, G.; Ottaviano, P.A.; Perla, M.
• Is Part Of: Journal of energy storage. Volume 30(2020)
• Publication Date: 2020-08
• Subjects: LNG -- Power-to-fuel -- Hydromethane -- Gas upgrading -- Renewable fuels; CFZ Controlled Freeze Zone -- COP21 21st yearly session of the Conference of the Parties - United Nations Framework Convention on Climate Change (UNFCCC) -- DEA diethanolamine -- DGA diglycolamine -- ESS energy storage systems -- GHG grennhouse gasses -- GPP Gas Power Package -- GTP gas treatment package -- LNG liquefied natural gas -- MDEA methyldiethanolamine -- MEA monoethanolamine -- MEG monoethylene glycol -- PSA Pressure Swing Adsorption -- RES renewable energy sources -- TEG triethylene glycol -- TCR Total Contaminant Removal -- TSA temperature swing adsorption -- VOC volatile organic compounds; Energy storage -- Periodicals; Energy storage -- Research -- Periodicals; 621.3126
• DOI: 10.1016/j.est.2020.101471
• Languages: English
• ISSNs: 2352-152X

Abstract

Highlights: Low temperature gas upgrading techniques are discussed. Processed gas is hydromethane obtained through electrolysis and methanation. Techniques are reviewed to meet LNG quality requirements and grid EN 16726 standard. LNG can be used in transport application or in the gas grid after regasification. Abstract: Power-to-fuel applications represent a relevant option among energy storage technologies to overcome grid issues, such as overgeneration due to renewable energy sources exploitation. The production of raw hydromethane mixture, through water electrolysis and, downstream, methanation, can be integrated in power to liquefied natural gas systems allowing the exploitation of liquefied natural gas as energy carrier. It enables multiple uses linking multiple sectors (e.g. transport, industry, electric power production). Cryogenic separation techniques could be implemented aiming to an enhanced overall conversion efficiency. Key of this systematic review is the identification and analysis of the gas upgrade technologies that, moving from the raw hydromethane mixture, guarantee a final liquefied natural gas composition meeting the requirements imposed by: (i) grid injection and use in conventional endothermal engines after regasification (2 vol% H2 ); (ii) particular sensitivity of the natural gas liquefaction process to the presence of water (< 0.1 ppm) and CO2 (< 50 ppm). A critical review for hydromethane upgrade which faces the issues of real utilization is not available in literature, thus it is provided in this work. The paper is structured in two main parts: in the first gas dehydration techniques are described, while the second focuses on CO2 separation, highlighting advantages and application limits of low temperature techniques to the case of study. In the conclusions, a process optimal configuration is discussed for the production of liquefied natural gas from renewable electricity, as energy carrier suitable for multisectoral applications and compliant with scenarios of high renewable energy penetration.