CO₂ Capture in SOFC by Vapor Condensation and CH₄ Production in SOEC Storing Excess Electricity

Abstract

Simple CO2 capture in combined solid oxide fuel cell (SOFC) gasification or reforming (of hydrocarbons – fossil or biomass) cycles by condensing the water vapor of the anode exhaust gas after CO shifting and H2 recycling by a membrane is simulated. High efficiency of about 60 % is demonstrated. The separated CO2 can be stored in a two‐chamber tank at the same pressure and temperature as methane on the two sides of a flexible membrane which divides the tank into chambers since 1 mol CH4 results in 1 mol CO2. In a solid oxide electrolyzer cell (SOEC), CO2 and steam can be recombined to CH4 using excess electricity, e.g., produced by wind or solar power, and O2 is left over. Thus, excess electricity can be stored chemically. Such a cycle allows hybrid vehicles with SOFC as range extender, running as zero‐emission vehicles also when using natural gas.

Defects and Phase Formation in Non-Stoichiometric LaFeO3: a Combined Theoretical and Experimental Study

“…Figure 2). The concentration of oxygen vacancies in their preferred positive ionization state (+2) follows an opposite trend, decreasing from 10 18 to about 10 15 per cm 3 for increasing oxygen pressure. A qualitatively similar behavior was reported by Waernhus et al, 28 as indicated in Figure 4 by the black symbols, which represent concentrations of oxygen vacancies (triangles) and cation vacancies (circles) given in their work.…”

“…For the two samples with nominal compositions y = 0.96 and y = 0.9, quantitative phase analysis yielded amounts of about 2.1 ± 0.4 vol % and of 4.6 ± 0.6 vol % of Fe 2 O 3 , respectively. From the densities of LFO (6.51 g/cm 3 ) and Fe 2 O 3 (5.03 g/cm 3 ), one calculates 1.74 vol % for y = 0.96 and 4.52 vol % for y = 0.9 under the assumption that no Ladeficient LFO can be formed. Therefore, our experimental results are in agreement with the conclusion made from our theoretical results, namely, that there is no considerable La deficiency realized by vacancies in the LFO structure.…”

“…Owing to their ability to transform chemical energy into electrical energy and vice versa, solid-oxide fuel cells and solid-oxide electrolyzer cells (SOFCs and SOECs) are widely regarded as key technologies to realize the energy transition process . For example, in an innovative approach (“Power-to-X”), SOECs are utilized to transform water and CO 2 into H 2 and CO by so-called co-electrolysis, , using renewable excess energy (from wind and sunlight) available in times of low demand. The produced gases can be stored for later use and then converted back into electrical energy by SOFCs or further processed by the chemical industry .…”

Modelling of SOEC-FT reactor: Pressure effects on methanation process

“…Stempien, et al [9] thermodynamically assessed the methane production by SOEC considering Sabatier reaction and methane steam reforming reaction. C. Schlitzberger et al [10] proposed a novel two tank chemical storage system combining SOFC and SOEC for the CO2 capture and methane production. T. Kato et al [11] compared the methanation performance of SOEC and traditional water electrolyser + methanator system.…”

Modelling of a Solid Oxide Water Electrolyzers and Investigation of the Cell Performance on Different Working Conditions

“…Bunun yanı sıra CO 2 ve su buharı ile hidrojen ve oksijen gazı üretebilmeleri bazı kritik uygulamalarda bu sistemleri çok kullanışlı hale getirmektedir. Sistemin kullandığı teknolojiden kaynaklı olarak elde edilen faradaik verim, CO 2 'nin direk elektrolizine de imkan vermektedir [11,12]. Örneğin, CO2 gazının enerji üretimi ve dönüşümünde kullanılması sera gazı salınımlarını azaltabildiği gibi oluşan ürünler sayesinde, CO 2 atmosferine sahip Mars gezegen koşulları gibi ortamlarda farklı bir araştırma boyutu kazanmıştır [8,13].…”