Electrochemical Capture of CO₂from Natural Gas Using a High-Temperature Ceramic-Carbonate Membrane

Abstract

This study reports the first investigation of using a ceramic-carbonate dual-phase membrane to electrochemically separate CO 2 from a simulated natural gas. The CO 2 permeation flux density was systematically studied as a function of temperature, CO 2 partial pressure and time. As expected, the flux density was observed to increase with temperature and CO 2 partial pressure. Long-term stability test showed that flux density experienced an initial performance-improving "break-in" period followed by a slow decay. Post-test microstructural analysis suggested that a gradual loss of carbonate during the test could be the cause of the flux-time behavior observed. © The Author(s) 2015. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. [DOI: 10.1149/2.0481504jes] All rights reserved.Manuscript submitted November 17, 2014; revised manuscript received January 7, 2015. Published January 24, 2015.Natural gas is a cleaner burning and flexible alternative to other fossil fuels, and is widely used in power generation, residential, industrial, and transportation sectors.1,2 Sources of natural gas include conventional onshore and offshore wells and unconventional wells that rely on stimulation technologies to enhance natural gas recovery in the reservoir. Examples of the latter include hydraulic fracturing in shale and water removing in coal bed methane (CBM) wells. 3,4The composition of natural gas varies considerably with sources, and even within a source. 5,6 Other than minor amounts of H 2 S, H 2 O, N 2 , He and VOC (volatile organic compounds), CO 2 concentration in a natural gas can vary from 0 to 70%, see Table I. As an acidic gas, CO 2 must be removed prior to transportation in order to protect pipelines. During the removal process, avoiding accidental CH 4 release to the atmosphere is also important since CH 4 is a heat-trapping gas 86 times more powerful than CO 2 . Therefore, a safe, efficient and low-cost separation process for CO 2 removal from raw natural gas is technologically and environmentally important. The conventional means of removing CO 2 from a CO 2 /CH 4 mixture is based on reversible sorbent/solvent adsorption/absorption processes. Pressure swing adsorption (PSA) using zeolite, 12 metal organic framework (MOF) mol·s −1 ·m −2 ·Pa −1 under a pressure differential of 40 KPa using a zeolite imidazolate framework (ZIF) membrane, but with a selectivity of 5.1. 26 As well documented in the literature, the trade-off between permeability and selectivity (or so called "Robeson Upper Bound") is a major barrier for the aforementioned membranes to overcome. 27,28 Furthermore, the requirement for high-pressure feed and low operating-temperature makes the organic membranes only suitable for high-pressure and low-temperature CO 2 separation from streams such as pre-combustion products whe...

A superior mixed electron and carbonate-ion conducting metal-carbonate composite membrane for advanced flue-gas carbon capture

“…With a similar electrochemical principle, our group as well as others recently proposed two new types of carbon capture membranes made of ceramic-carbonate and metalcarbonate dual-phase composites [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]…”

CO2 capture using membrane contactors: a systematic literature review

“…[447][448][449][450][451]453,454,456,458,459,[463][464][465][466][467]472,473,475,[478][479][480]482,483,[484][485][486][487][488][489]496,497,[500][501][502]505,506,508,513,514,516,517,519,521,523,524,528,533,538,543]. One of the reasons for the low popularity of hydrophilic membranes is the low thermal and chemical stability of membranes, which in turn has an effect on the flux, demonstrated in Table…”

“…358,365,372,382,414,423,427,433,449,459,469,472,474,475,492,517,518,520,524,529]. A further 43 studies (8%) set the gas flow rate in the range of 100 < flow < 1000[25,27,37,38,40,47,49,60,70,72,73,76,85,104-106,115, 122,128,131,134,150,152-154,161,162,167,195,285, 321,327,364,397,402,417,423,439,469,479,515,521,522].…”

Recent Advances in Molten-Carbonate Membranes for Carbon Dioxide Separation: Focus on Material Selection, Geometry, and Surface Modification

“…CO 2 flux was measured at different partial pressures of CO 2 at feed side. Highest CO 2 flux of 0.13 ml•min −1 •cm −2 was obtained at CO 2 partial pressure of 0.375 atm (Figure 13(a)) [70]. us, MOCC membranes can also be employed in purification of shale gas/biogas.…”

“…Figure13: CO 2 flux density of SDC membrane (a) as a function of logarithm of CO 2 partial pressure[70], (b) as a function of H 2 partial pressure[26], and (c) in the presence and absence of H 2[63].…”