Ekain Maiza-Razkin , Garikoitz Beobide , Oscar Castillo , Antonio Luque , Rubén Pérez-Aguirre , Sonia Pérez-Yañez
{"title":"CO2 capture from water using a copper/chromium-adenine supramolecularly assembled porous metal-organic material","authors":"Ekain Maiza-Razkin , Garikoitz Beobide , Oscar Castillo , Antonio Luque , Rubén Pérez-Aguirre , Sonia Pérez-Yañez","doi":"10.1016/j.jcou.2025.103144","DOIUrl":"10.1016/j.jcou.2025.103144","url":null,"abstract":"<div><div>A supramolecular metal-organic porous material [CrCu<sub>6</sub>(μ-adeninato-к<em>N3</em>:к<em>N9</em>)<sub>6</sub>(μ-OH)<sub>6</sub>(μ-OH<sub>2</sub>)<sub>6</sub>](SO<sub>4</sub>)<sub>1.5</sub> (<strong>Cu</strong><sub><strong>6</strong></sub><strong>Cr</strong>) has been tested for CO<sub>2</sub> capture from water. The properties of this compound, insolubility in water, a flexible supramolecular structure, and protonable positions on the adeninato ligands, make it a potential candidate for this task. The experimental determination of CO<sub>2</sub> capture from water was performed using two techniques: magnetic sustentation, for first time, and gravimetric measurements. Both techniques verified the CO<sub>2</sub> capture providing complementary information. The magnetic sustentation technique measures the mass being incorporated into the porous material (which depends on the chemical form in which is being captured: physisorption, HCO<sub>3</sub><sup>-</sup> or carbamate), whereas the gravimetric measurement quantifies the total mass of CO<sub>2</sub> being captured in the aqueous suspension of the <strong>Cu</strong><sub><strong>6</strong></sub><strong>Cr</strong> particles regardless the chemical form in which this capture takes place. After 1 hour of CO<sub>2</sub> bubbling (300 mL·min<sup>−1</sup>) into the aqueous suspension of <strong>Cu</strong><sub><strong>6</strong></sub><strong>Cr</strong> particles, capture mass values of 22.3 % and 17.1 % are measured by magnetic sustentation and gravimetric techniques, respectively. This difference is because the CO<sub>2</sub> is captured as H<sub>2</sub>CO<sub>3</sub> that reacts with the adeninato ligands to form adenine/HCO<sub>3</sub><sup>-</sup> pairs. These values normalize to 5.9 HCO<sub>3</sub><sup>-</sup> and 6.4 CO<sub>2</sub> molecules per <strong>Cu</strong><sub><strong>6</strong></sub><strong>Cr</strong> entity, which are close to the theoretical value of 6, because of the six adeninato ligands per heptameric <strong>Cu</strong><sub><strong>6</strong></sub><strong>Cr</strong> entity. CO<sub>2</sub> adsorption isotherms, adsorption/desorption kinetics and cycling stability are also reported. Kinetic studies provide a ΔH<sub>ads</sub> = -19.4 kJ/mol, which is a significantly lower than other CO<sub>2</sub> adsorbents. However, the cycling stability needs to be improved.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"98 ","pages":"Article 103144"},"PeriodicalIF":7.2,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144213478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Characterizing flow of pressurized CO2 through micro-orifice for atomization applications: Experiments and CFD modelling","authors":"Mohamad Baassiri , Vivek Ranade , Luis Padrela","doi":"10.1016/j.jcou.2025.103132","DOIUrl":"10.1016/j.jcou.2025.103132","url":null,"abstract":"<div><div>Improving therapeutic efficacy of newly developed drugs remains a major challenge for the pharmaceutical industry. Spray drying based on atomization using high pressure or supercritical CO<sub>2</sub> has been shown to be effective in improving therapeutic efficiency of drugs by forming smaller particles, owing to the distinct solvation power and enhanced mixing potential of supercritical CO<sub>2</sub>. Several parameters contribute to the critical quality attributes of the final atomized pharmaceutical products resulting from CO<sub>2</sub>-assisted atomization including high-pressure nozzle design, drying chamber geometry, and operating pressures and temperatures. In this context, the work is focused on a detailed analysis of supercritical CO<sub>2</sub> through micro-orifices used in a spray drying enhanced atomization process. We present a computational fluid dynamics model, developed using Ansys FLUENT, to describe the flow of pure, pressurized CO<sub>2</sub> through a micro-orifice undergoing trans-critical expansion. After establishing grid independence, the computational model was validated by comparing model predictions to measured mass flow rates and temperature distribution of the cooling effect of CO<sub>2</sub> free jet over an adiabatic surface. For supercritical inlet conditions and a nozzle orifice size of 80 µm, experimental results matched predictions reasonably well. The simulated results demonstrated the occurrence of shock waves, a prerequisite for fine droplets formation. Simulated results were critically analyzed to develop new insights into intricate fluid dynamics of flow of CO<sub>2</sub> through atomization orifices and an attempt is made to evolve specific guidelines. The presented model and results will be useful for researchers and engineers interested in understanding and optimizing CO<sub>2</sub>-assisted spray atomization processes.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"98 ","pages":"Article 103132"},"PeriodicalIF":7.2,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144213480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kedar Bharat Jivrakh , Ayesha Alkhoori , Miguel Palomino , L.M. Andrés-Olmos , Antonio Chica , Fernando Rey , Susana Valencia , Kyriaki Polychronopoulou , Rashid Abu Al-Rub , Nahla Alamoodi , Georgios N. Karanikolos
{"title":"A 3D-printed metal-supported gyroid Ni/Al2O3 catalyst for CO2 methanation","authors":"Kedar Bharat Jivrakh , Ayesha Alkhoori , Miguel Palomino , L.M. Andrés-Olmos , Antonio Chica , Fernando Rey , Susana Valencia , Kyriaki Polychronopoulou , Rashid Abu Al-Rub , Nahla Alamoodi , Georgios N. Karanikolos","doi":"10.1016/j.jcou.2025.103143","DOIUrl":"10.1016/j.jcou.2025.103143","url":null,"abstract":"<div><div>The utilization of 3D-printing in catalyst production for CO<sub>2</sub> methanation has emerged as a response to the challenges posed by the highly exothermic reaction and high gas space velocity, conditions that necessitate enhanced heat and mass transfer while maintaining optimal catalytic performance. In this work, we developed a new CO<sub>2</sub> methanation catalyst comprising a Ni/Al<sub>2</sub>O<sub>3</sub> powder-coated 3D-printed aluminum alloy of gyroid configuration. The metallic alloy (AlMgSi) was 3D-printed (3DAL) using selective laser melting (SLM), and Ni/Al<sub>2</sub>O<sub>3</sub> powder was coated on it by washcoating. Microscopy and tomography techniques were employed to examine the morphological characteristics of the catalyst and to analyze internal topology, and hydrogen temperature-programmed reduction (H<sub>2</sub>-TPR) and chemisorption provided insights into the reduction sites and active metal phase. The catalytic performance was assessed through CO<sub>2</sub> methanation experiments at various temperatures ranging from 250 °C to 500 °C, using a CO<sub>2</sub>:H<sub>2</sub>:He gas mixture (1:4:5). The 3D-printed Ni/Al<sub>2</sub>O<sub>3</sub>-3DAL catalyst exhibited high CH<sub>4</sub> selectivity (97.7 %) and CO<sub>2</sub> conversion (77.6 %) at 400 °C, which is attributed to the reduced tendency of sintering and the effective heat transfer owing to the metallic support. The 3D-printed gyroid metallic support provided a higher surface area-to-volume ratio enabling higher catalyst loading per unit volume, and improved reactants contact with the active catalyst phase yielding enhanced catalytic performance compared to powder. It also offers enhanced thermal energy management and heat dissipation, which are critical for highly exothermic reactions such as CO<sub>2</sub> methanation, as well as mechanical strength compared to conventional beads and pellets.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"98 ","pages":"Article 103143"},"PeriodicalIF":7.2,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144213479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sixiang Kang , Chenhao Song , Jize Wang , Wenda Wu , Tao Wang , Leiming Ling , Huaqiang Sun , Ying Lou , Xuefang Wang , Liwei Xu
{"title":"Combined mechanochemical and solid CO2 treatment for enhanced carbon uptake and performance of slag-based geopolymers","authors":"Sixiang Kang , Chenhao Song , Jize Wang , Wenda Wu , Tao Wang , Leiming Ling , Huaqiang Sun , Ying Lou , Xuefang Wang , Liwei Xu","doi":"10.1016/j.jcou.2025.103129","DOIUrl":"10.1016/j.jcou.2025.103129","url":null,"abstract":"<div><div>In response to the high carbon emissions from cement production, carbon mineralization for CO<sub>2</sub> sequestration and alternative cementitious materials have gained attention. However, carbon mineralization faces equipment and energy challenges, while geopolymer materials suffer from poor workability. This study proposes a novel method combining mechanochemical activation and dry ice (solid CO<sub>2</sub>) and explores its effects on the behavior of slag based geopolymer (SBG) mortar. This study demonstrates that, compared to the individual addition of dry ice or mechanical activation alone, using dry ice as a grinding medium allows it to embed into the particle structure in the form of distorted carbonates. The mechanochemical process continuously disrupts the carbonate layer, exposing fresh unreacted surfaces, thereby promoting ongoing reactions and significantly enhancing the carbon sequestration efficiency of SBG. While the addition of dry ice delays early hydration reactions, it promotes the generation of increasing hydration and carbonation products in the mid to late stages, enhancing the mortar's density and strength. Specifically, at a dry ice content of 2.7 % with mechanochemical processes, the comprehensive performance of SBG mortar is optimal after mechanochemical mixing, exhibiting moderate workability (214 mm fluidity), high compressive strength (54.8 MPa at 28d), low drying shrinkage (623µε at 28d), and strong resistance to chloride ion penetration (1884.18 C electrical flux).</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"98 ","pages":"Article 103129"},"PeriodicalIF":7.2,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144204673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sam Van Daele, Gabriele Cioli, Daniel Choukroun, Tom Breugelmans
{"title":"The impact of flue gas impurities on the electrochemical reduction of carbon dioxide with copper catalysts","authors":"Sam Van Daele, Gabriele Cioli, Daniel Choukroun, Tom Breugelmans","doi":"10.1016/j.jcou.2025.103107","DOIUrl":"10.1016/j.jcou.2025.103107","url":null,"abstract":"<div><div>The direct electrochemical reduction of CO<sub>2</sub> to C<sub>2+</sub> products from flue gases is a promising route to convert waste CO<sub>2</sub> into valuable products without expensive capture and purification steps. However, impurities may hamper the efficiency and stability. Here we investigate the impact of N<sub>2</sub>, O<sub>2</sub>, SO<sub>2</sub> and NO on CO<sub>2</sub> electrolysis with Cu catalysts. While N<sub>2</sub> causes a diluting effect without side reactions, O<sub>2</sub> is responsible for a parasitic reduction reaction that accounts for <em>></em> 85 % Faradaic efficiency at 5 % O<sub>2</sub>. The development of a PTFE GDE architecture prevents all oxygen reduction on the carbon substrate and achieves 40.1 % Faradaic efficiency to C<sub>2+</sub> at 350 mA/cm<sup>2</sup> with a 4 % O<sub>2</sub> impurity. Finally, stability measurements with NO or SO<sub>2</sub> were conducted at 100 mA/cm<sup>2</sup> and show that ∼200 ppm NO has a negligible influence on the performance, but ∼200 ppm SO<sub>2</sub> irreversibly shifts the product distribution from C<sub>2+</sub> products to formate. This work comprises crucial information to potentially bypass the CO<sub>2</sub> purification steps, increasing economical viability.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"97 ","pages":"Article 103107"},"PeriodicalIF":7.2,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144194824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hang Zeng , Liam Fox Ellersick , Thomas Tawiah Baah , Xiangping Xian , HeeJeong Kim
{"title":"Carbonation curing for recycling and property enhancement of copper slag-based blended mortar","authors":"Hang Zeng , Liam Fox Ellersick , Thomas Tawiah Baah , Xiangping Xian , HeeJeong Kim","doi":"10.1016/j.jcou.2025.103130","DOIUrl":"10.1016/j.jcou.2025.103130","url":null,"abstract":"<div><div>This study explores a potential pathway to utilize CO<sub>2</sub> and copper slag (CS) to reduce CO<sub>2</sub> emissions and to enhance the mechanical properties of ordinary Portland cement (OPC)-CS-based cementitious materials. Early age carbonation curing was applied to cure the blended mixtures with varying carbonation durations. The results indicate an improvement in mechanical properties particularly in the early stages. The ultrasonic pulse velocity (UPV) method has proven effective in detecting the subtle changes in microstructure resulting from variations of mixture design and carbonation curing. XRD, TGA, FTIR and SEM were conducted to characterize the influence of carbonation curing on mechanical properties, microstructural development, and their interrelationship. The CS acts as an inert filler in the cement matrix and increases the available surface area and space for the nucleation and formation of carbonation products, in turn leading to a higher CO<sub>2</sub> uptake compared to the OPC reference. Both amorphous and crystalline carbonates contributed to microstructure densification. Moreover, a prolonged carbonation duration modified the silicate structure within C-S-H gel without further reducing the amount of C-S-H, and it did not negatively impact the mechanical properties. Cost and CO<sub>2</sub> emission analyses confirm that adopting CS replacement and carbonation curing can reduce carbon footprint. Besides, the incorporation of CS can reduce the operational cost of carbonation curing, potentially bringing expenses down to levels comparable with those of normal curing.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"97 ","pages":"Article 103130"},"PeriodicalIF":7.2,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144194825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aingeru Remiro, Leire Landa, José Valecillos, Sergio Iglesias-Vázquez, Javier Bilbao, Ana G. Gayubo
{"title":"Stability and complete regeneration of a Ni/MgAl2O4 catalyst in combined steam/dry reforming of raw bio-oil","authors":"Aingeru Remiro, Leire Landa, José Valecillos, Sergio Iglesias-Vázquez, Javier Bilbao, Ana G. Gayubo","doi":"10.1016/j.jcou.2025.103142","DOIUrl":"10.1016/j.jcou.2025.103142","url":null,"abstract":"<div><div>The combined steam and dry reforming (CSDR) of bio-oil (the liquid product from biomass pyrolysis) represents an attractive pathway for CO<sub>2</sub> valorization along with sustainable syngas production. This study compares the performance in the CSDR process of a Ni catalyst supported on MgAl<sub>2</sub>O<sub>4</sub> spinel with 15 wt% Ni (15Ni/MgAl<sub>2</sub>O<sub>4</sub>), with that of Ni catalysts supported on Al<sub>2</sub>O<sub>3</sub> prepared by different methods. The reactions were carried out in an automatized equipment with two units, for controlled pyrolytic lignin deposition in the first unit while the feed is volatilized (thermal treatment), and for reforming of the remaining oxygenates in the second unit in-line (fluidized bed reactor). The catalysts have been used under reaction-regeneration cycles. The reaction conditions were: 700 °C, CO<sub>2</sub>/C molar ratio, 0.6; steam/C ratio, 0.5; space time, 0.042 g<sub>Ni</sub>·h/g<sub>oxygenates</sub>, and; time on stream, 6 h. The regeneration is performed in-situ, by coke combustion with air at 850 ºC for 2 h. The catalytic performance (activity, selectivity, stability and regenerability) is explained on the basis of the characterization results of the used and regenerated catalysts and the deposited coke. Although the initial CO<sub>2</sub> conversion (in the 14–18 % range) and syngas yield (in the 88–98 % range) show no significant differences among the catalysts, variations in catalyst stability and regeneration capacity are remarkable. Specifically, the 15Ni/MgAl<sub>2</sub>O<sub>4</sub> catalyst is the most suitable candidate for scaling up CSDR of bio-oil, due to its high stability (similar to that of the 36Ni/Al<sub>2</sub>O<sub>3</sub>-cp catalyst, obtained by reduction of a stoichiometric NiAl<sub>2</sub>O<sub>4</sub> spinel) and reproducible behavior in reaction-regeneration cycles.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"97 ","pages":"Article 103142"},"PeriodicalIF":7.2,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144189400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Oscar E. Medina , Andrés A. Amell , Diana López , Alexander Santamaría
{"title":"Tailoring Ni-based poly-metallic catalysts for enhanced CO2 methanation through a Simplex-Centroid Mixture Design (SCMD)","authors":"Oscar E. Medina , Andrés A. Amell , Diana López , Alexander Santamaría","doi":"10.1016/j.jcou.2025.103124","DOIUrl":"10.1016/j.jcou.2025.103124","url":null,"abstract":"<div><div>The study explored the development and optimization of Ni-based polymetallic catalysts for CO₂ methanation using a systematic Simplex-Centroid Mixture Design (SCMD). This approach aimed to maximize catalytic performance while ensuring stability and catalytic effectiveness. The research began by selecting optimal Ni loading on alumina (γ-Al₂O₃) support, revealing a 10 wt% Ni content yielded the highest CO₂ conversion. Various promoters, including Ce, La, Fe, Co, and Mg, were then evaluated to enhance catalytic efficiency, with Ce emerging as the most effective. Ce addition significantly improved CO₂ conversion and CH₄ selectivity, and among the optimized formulations, AlNi<sub>9.2</sub>Ce<sub>8.3</sub> achieved 78 % CO₂ conversion and 99 % CH₄ selectivity at 350 °C. Incorporating Y₂O₃ into the γ-Al₂O₃ support provided further advancements in catalyst performance, particularly in improving the catalyst's thermal stability, thereby reducing sintering and enhancing overall durability. However, the amount of Y₂O₃ was crucial; while optimal Y₂O₃ content (5 wt%) stabilized active sites and enhanced metal dispersion, excessive Y₂O₃ could obstruct catalytic sites (> 15 wt%), negatively affecting performance. Characterization analyses, including X-ray diffraction (XRD), Raman spectroscopy, and H₂ temperature-programmed reduction (H₂-TPR), showed 5–10 wt% Y₂O₃ addition increased oxygen vacancy formation, increased catalyst reducibility, reduced Ni particle sintering, and inhibited coke deposition and spinel (NiAl₂O₄) formation. The SCMD-enabled catalyst design successfully balanced Ni, Ce, and Al₂O₃ contents to deliver efficient CO₂ methanation. The tailored Ni-based catalysts thus demonstrated improved resistance to degradation mechanisms and greater catalytic efficiency, positioning them as promising candidates for sustainable CO₂ conversion and CH<sub>4</sub> production.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"97 ","pages":"Article 103124"},"PeriodicalIF":7.2,"publicationDate":"2025-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144185445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Comparison and reliability assessment of CO2 quantification methods for carbonated cementitious materials","authors":"Katsuya Namiki , Kazuya Yamashita , Kazuto Tabara , Suguru Noda","doi":"10.1016/j.jcou.2025.103140","DOIUrl":"10.1016/j.jcou.2025.103140","url":null,"abstract":"<div><div>Various CO<sub>2</sub>-absorbing concretes have been developed; however, an accurate assessment of their CO<sub>2</sub> content is critically important. CO<sub>2</sub> has been quantified by releasing it from concrete and measuring the sample mass loss and/or the released CO<sub>2</sub>; however, the differences between these methods remain unexplored. In this study, cementitious materials were carbonated and evaluated using five analysis methods. The presence of free water in the samples and moisture adsorption significantly affected the sample mass. Therefore, all the samples were ground and dried by heating in vacuum before analysis. Heating above 980 °C or immersion in HCl was effective for CO<sub>2</sub> release, and non-dispersive infrared spectroscopy and coulometric titration were effective for quantifying released CO<sub>2</sub>, with measurement variance within ± 5 %. However, CO<sub>2</sub> release using H<sub>3</sub>PO<sub>4</sub> was insufficient, leading to an underestimation of up to 12 %. The combination of temperature-programmed desorption and non-dispersive infrared spectroscopy had the best reproducibility among the five methods and clearly showed that CO<sub>2</sub> and H<sub>2</sub>O were released simultaneously at the moderate temperature range. This overlap causes difficulties in the popular thermogravimetric analysis which attributes the mass change below/above a threshold temperature to H<sub>2</sub>O/CO<sub>2</sub>, respectively. CO<sub>2</sub> contents were underestimated due to the unaccounted CO<sub>2</sub>-derived mass loss for CO<sub>2</sub>-rich samples and/or high threshold temperatures while overestimated due to misincluded H<sub>2</sub>O-derived mass loss for H<sub>2</sub>O-rich samples and/or low threshold temperatures. This study presents a highly reliable approach for assessing CO<sub>2</sub> fixation, which is essential for calculating the carbon footprints of various cementitious materials and concrete.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"97 ","pages":"Article 103140"},"PeriodicalIF":7.2,"publicationDate":"2025-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144185446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zainab Ul , Mira Sulonen , Philip Haus , Paniz Izadi , Juan Antonio Baeza , Falk Harnisch , Albert Guisasola
{"title":"Evaluation of single chamber electrochemical reduction of CO2 to formate for application under biocompatible conditions","authors":"Zainab Ul , Mira Sulonen , Philip Haus , Paniz Izadi , Juan Antonio Baeza , Falk Harnisch , Albert Guisasola","doi":"10.1016/j.jcou.2025.103136","DOIUrl":"10.1016/j.jcou.2025.103136","url":null,"abstract":"<div><div>The electrochemical CO<sub>2</sub> reduction reaction (eCO<sub>2</sub>RR) facilitates high rates and yields for the selective production of formate, a quintessential C1-compound that can serve as a valuable carbon and energy source for biosynthesis. The use of double-chamber (DC) electrochemical cells with membranes is deemed essential to avoid mixing of electrochemical products (i.e. anodic oxygen and cathodic formate) and thus cross-reactions that lower yields, Faradaic efficiency (FE) and effective rate. However, single-chamber (SC) setups for eCO<sub>2</sub>RR can be more suitable to combine with bioprocesses. This work comprehensively evaluates, using different experimental set-ups, the conditions under which SC operation can obtain results comparable to DC systems. At a 50 mL scale, under biocompatible conditions, formate production in the SC setup achieved a 14 % reduction in the production rate (146 mg L<sup>−1</sup> h<sup>−1</sup> for SC and 170 mg L<sup>−1</sup> h<sup>−1</sup> for DC) and a 15 % decrease in FE (72.2 % in SC and 84.7 % in DC). The highest formate concentration produced in 24 h SC experiments was 1.8 g·L<sup>−1</sup> with FE of 41 %, a concentration appropriate for fermentation processes. The SC operation of eCO<sub>2</sub>RR to formate without a membrane could reduce energy losses and capital costs, although at the cost of an expected reduction in rate and FE.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"97 ","pages":"Article 103136"},"PeriodicalIF":7.2,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}