The integration of accelerated carbonation with the utilization of steelmaking slags presents a vital strategy for CO2 mineralization towards net-zero scheme. This study simultaneously evaluates basic oxygen furnace slag (BOFS), refining slag (RFS), and electric arc furnace reducing (EAFRS) and oxidizing slags (EAFOS) as potential partial replacements for ordinary Portland cement, at substitution levels ranging from 5 % to 15 % as supplementary cementitious materials (SCMs). These slags were pretreated through aqueous accelerated carbonation in a high-gravity rotating packed bed. We assessed several parameters, including carbonation conversion, CO2 capture capacity, workability, strength, and durability. The results demonstrated that EAFRS achieved the highest CO2 capture capacity, reaching 0.193 kg-CO2/kg-slag with a maximum carbonation conversion of 46 % under 197 times high-gravity conditions and a liquid-to-solid ratio of 20. While the incorporation of carbonated slags had minimal impact on the setting properties of cement pastes, higher substitution ratios necessitated increased water demand. The strength of blended cement containing 5 %, 10 %, and 15 % of carbonated BOFS, RFS, and EAFRS met standard requirements at 28th day. Additionally, a mathematical model was developed to predict the mechanical strength of cement mortars. The introduction of carbonated BOFS, RFS, and EAFRS facilitated hydration due to the formation of calcium carbonates, although it resulted in slower strength development kinetics. Notably, the replacement of cement with carbonated EAFOS exhibited a higher expansion rate, likely due to its elevated silicon dioxide and alkaline species content, which may lead to alkali-aggregate reactions, resulting in expansion and cracking.
{"title":"Simultaneously comparing various CO2-mineralized steelmaking slags as supplementary cementitious materials via high gravity carbonation","authors":"Tse-Lun Chen , Bo-Kai Shu , Yi-Hung Chen , Pen-Chi Chiang","doi":"10.1016/j.jcou.2024.102985","DOIUrl":"10.1016/j.jcou.2024.102985","url":null,"abstract":"<div><div>The integration of accelerated carbonation with the utilization of steelmaking slags presents a vital strategy for CO<sub>2</sub> mineralization towards net-zero scheme. This study simultaneously evaluates basic oxygen furnace slag (BOFS), refining slag (RFS), and electric arc furnace reducing (EAFRS) and oxidizing slags (EAFOS) as potential partial replacements for ordinary Portland cement, at substitution levels ranging from 5 % to 15 % as supplementary cementitious materials (SCMs). These slags were pretreated through aqueous accelerated carbonation in a high-gravity rotating packed bed. We assessed several parameters, including carbonation conversion, CO<sub>2</sub> capture capacity, workability, strength, and durability. The results demonstrated that EAFRS achieved the highest CO<sub>2</sub> capture capacity, reaching 0.193 kg-CO<sub>2</sub>/kg-slag with a maximum carbonation conversion of 46 % under 197 times high-gravity conditions and a liquid-to-solid ratio of 20. While the incorporation of carbonated slags had minimal impact on the setting properties of cement pastes, higher substitution ratios necessitated increased water demand. The strength of blended cement containing 5 %, 10 %, and 15 % of carbonated BOFS, RFS, and EAFRS met standard requirements at 28th day. Additionally, a mathematical model was developed to predict the mechanical strength of cement mortars. The introduction of carbonated BOFS, RFS, and EAFRS facilitated hydration due to the formation of calcium carbonates, although it resulted in slower strength development kinetics. Notably, the replacement of cement with carbonated EAFOS exhibited a higher expansion rate, likely due to its elevated silicon dioxide and alkaline species content, which may lead to alkali-aggregate reactions, resulting in expansion and cracking.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"90 ","pages":"Article 102985"},"PeriodicalIF":7.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-01DOI: 10.1016/j.jcou.2024.102991
Zheng Zhang , Junkang Sang , Mingzhong Shen , Anqi Wu , Kailiang Wang , Junhua Su , Fei Wang , Yingying Han , Wanbing Guan
Methane synthesis from CO2 is an important process for transforming and storing renewable electrical energy, and one of the main issues facing methanation catalysts is stability. Herein, a plate-and-tube structured porous metal-ceramic Ni-YSZ reactor with high-temperature sintering was designed to produce CH4 from CO2 at atmospheric pressure and 325°C. The reactor was steadily operated for 1000 hours. The results showed that both the CO2 conversion and the CH4 selectivity continuously stayed over 90 % and 99.9 %, respectively. The results of in situ infrared and in situ programmed warming characterizations demonstrated that the hydrogenation of oxygen vacancies on the surface of Ni-O-Zr was the main pathway by which CO2 was converted to CH4 in this reactor. Moreover, the strongly basic adsorbed HCOO* and CO* intermediates facilitated further hydrogenation. This reactor structure decreases the reduction in reaction activity associated with catalyst sintering, coalescence, and carbon accumulation. Moreover, it provides a novel approach to reactor design for the stable operation of CO2-derived methane at high temperatures.
{"title":"A sintered Ni-YSZ catalytic reactor for highly efficient synthesis of green CH4","authors":"Zheng Zhang , Junkang Sang , Mingzhong Shen , Anqi Wu , Kailiang Wang , Junhua Su , Fei Wang , Yingying Han , Wanbing Guan","doi":"10.1016/j.jcou.2024.102991","DOIUrl":"10.1016/j.jcou.2024.102991","url":null,"abstract":"<div><div>Methane synthesis from CO<sub>2</sub> is an important process for transforming and storing renewable electrical energy, and one of the main issues facing methanation catalysts is stability. Herein, a plate-and-tube structured porous metal-ceramic Ni-YSZ reactor with high-temperature sintering was designed to produce CH<sub>4</sub> from CO<sub>2</sub> at atmospheric pressure and 325°C. The reactor was steadily operated for 1000 hours. The results showed that both the CO<sub>2</sub> conversion and the CH<sub>4</sub> selectivity continuously stayed over 90 % and 99.9 %, respectively. The results of <em>in situ</em> infrared and <em>in situ</em> programmed warming characterizations demonstrated that the hydrogenation of oxygen vacancies on the surface of Ni-O-Zr was the main pathway by which CO<sub>2</sub> was converted to CH<sub>4</sub> in this reactor. Moreover, the strongly basic adsorbed HCOO* and CO* intermediates facilitated further hydrogenation. This reactor structure decreases the reduction in reaction activity associated with catalyst sintering, coalescence, and carbon accumulation. Moreover, it provides a novel approach to reactor design for the stable operation of CO<sub>2</sub>-derived methane at high temperatures.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"90 ","pages":"Article 102991"},"PeriodicalIF":7.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-01DOI: 10.1016/j.jcou.2024.102987
Xiaojiao Cheng , Jinsuo Song , Hu Wen , Shixing Fan , Mingyang Liu , Wansheng Mi , Zhijin Yu , Yin Liu , Rijun Li
<div><div>Spontaneous gas and coal combustion represent primary disasters threatening the safety of underground coal mines. Achieving the collaborative governance of the two disasters and enhancing the ability to prevent and mitigate mine disasters are technical challenges faced by high-gas/outburst mines. CO<sub>2</sub> has become the primary choice for collaborative disaster governance because of its efficient control of the oxidation process of residual coal in goaf, enhanced coalbed methane (ECBM) recovery, and the goal of “2030 carbon peak and 2060 carbon neutralisation”. Therefore, this study adopted summary and engineering verification methods. Firstly, the basic physical and chemical properties of CO<sub>2</sub> were analysed, and the three mechanisms of action of liquid CO<sub>2</sub> for preventing coal spontaneous combustion (CSC), namely, “CO<sub>2</sub> adsorbed and hindered oxidation reactions, absorbs ambient heat and reduces ambient temperature, and reduce the oxygen concentration in the goaf and inhibiting gas explosion”, and the six mechanisms of action of liquid CO<sub>2</sub> ECBM recovery, namely, “pressure fracturing, low-temperature frostbite, physical extraction and chemical corrosion, low-viscosity permeability, phase change pressurisation, and competitive adsorption”, were summarised. Second, the effect was verified by the field application of liquid CO<sub>2</sub> CSC emergency prevention and control at the Qinggangping Coal Mine and the engineering test of liquid CO<sub>2</sub> ECBM recovery in the Shuanglong Coal Mine. Finally, based on the application status of liquid CO<sub>2</sub> in coal mines, a new model of “liquid CO<sub>2</sub> prevention and control of CSC and enhancing coalbed methane recovery comprehensive disaster reduction technology” is proposed. The results of the emergency prevention and control of liquid CO<sub>2</sub> CSC show that CO<sub>2</sub> sinking drives CH<sub>4</sub> out of the roadway, avoids the accumulation of CH<sub>4</sub> near the fire area, and achieves explosion suppression. The concentrations of C<sub>2</sub>H<sub>2</sub> and C<sub>2</sub>H<sub>4</sub> in the mine decreased rapidly to 0. No open fire or severe combustion occurred in the mine, and the fire area was effectively controlled. After the ventilation of the mine was restored, the isolated and closed 42108 working face was injected with liquid CO<sub>2</sub> again. The CO concentration of the inlet and return air along the channel gradually decreased to zero, and the fire area of the working face was further controlled. The engineering test of liquid CO<sub>2</sub>-ECBM recovery showed that the dominant seepage range was 12<img>15 m from the injection hole, and the dominant diffusion range was 25<img>30 m from the injection hole. The average CH<sub>4</sub> flow rate in the field extraction test was more than three times that of the original area. Through two field cases, long-distance liquid CO<sub>2</sub> prevention and con
{"title":"Mitigation of coal spontaneous combustion and enhanced coalbed methane recovery using liquid CO₂: Mechanisms, field applications, and implications for mines","authors":"Xiaojiao Cheng , Jinsuo Song , Hu Wen , Shixing Fan , Mingyang Liu , Wansheng Mi , Zhijin Yu , Yin Liu , Rijun Li","doi":"10.1016/j.jcou.2024.102987","DOIUrl":"10.1016/j.jcou.2024.102987","url":null,"abstract":"<div><div>Spontaneous gas and coal combustion represent primary disasters threatening the safety of underground coal mines. Achieving the collaborative governance of the two disasters and enhancing the ability to prevent and mitigate mine disasters are technical challenges faced by high-gas/outburst mines. CO<sub>2</sub> has become the primary choice for collaborative disaster governance because of its efficient control of the oxidation process of residual coal in goaf, enhanced coalbed methane (ECBM) recovery, and the goal of “2030 carbon peak and 2060 carbon neutralisation”. Therefore, this study adopted summary and engineering verification methods. Firstly, the basic physical and chemical properties of CO<sub>2</sub> were analysed, and the three mechanisms of action of liquid CO<sub>2</sub> for preventing coal spontaneous combustion (CSC), namely, “CO<sub>2</sub> adsorbed and hindered oxidation reactions, absorbs ambient heat and reduces ambient temperature, and reduce the oxygen concentration in the goaf and inhibiting gas explosion”, and the six mechanisms of action of liquid CO<sub>2</sub> ECBM recovery, namely, “pressure fracturing, low-temperature frostbite, physical extraction and chemical corrosion, low-viscosity permeability, phase change pressurisation, and competitive adsorption”, were summarised. Second, the effect was verified by the field application of liquid CO<sub>2</sub> CSC emergency prevention and control at the Qinggangping Coal Mine and the engineering test of liquid CO<sub>2</sub> ECBM recovery in the Shuanglong Coal Mine. Finally, based on the application status of liquid CO<sub>2</sub> in coal mines, a new model of “liquid CO<sub>2</sub> prevention and control of CSC and enhancing coalbed methane recovery comprehensive disaster reduction technology” is proposed. The results of the emergency prevention and control of liquid CO<sub>2</sub> CSC show that CO<sub>2</sub> sinking drives CH<sub>4</sub> out of the roadway, avoids the accumulation of CH<sub>4</sub> near the fire area, and achieves explosion suppression. The concentrations of C<sub>2</sub>H<sub>2</sub> and C<sub>2</sub>H<sub>4</sub> in the mine decreased rapidly to 0. No open fire or severe combustion occurred in the mine, and the fire area was effectively controlled. After the ventilation of the mine was restored, the isolated and closed 42108 working face was injected with liquid CO<sub>2</sub> again. The CO concentration of the inlet and return air along the channel gradually decreased to zero, and the fire area of the working face was further controlled. The engineering test of liquid CO<sub>2</sub>-ECBM recovery showed that the dominant seepage range was 12<img>15 m from the injection hole, and the dominant diffusion range was 25<img>30 m from the injection hole. The average CH<sub>4</sub> flow rate in the field extraction test was more than three times that of the original area. Through two field cases, long-distance liquid CO<sub>2</sub> prevention and con","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"90 ","pages":"Article 102987"},"PeriodicalIF":7.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-25DOI: 10.1016/j.jcou.2024.102984
Changming Li , Xudong Yang , Dongyang Jia , Shunbo Zhao , Guanfeng Liu , Yaozong Wang , Wanjiao Li , Wenyu Song
Magnesium and calcium-rich waste powder (MWP) has the potential to be a low-carbon geopolymer cementitious material. This study investigates the mechanical properties and hydration products of low-carbon magnesium and calcium-rich waste powder geopolymer paste (LMWP). The influences of alkali content, calcination temperature, mix proportions of raw materials and curing temperature on the compressive strength and hydration of LMWP were examined. The mechanical properties of LMWP were systematically evaluated by assessing setting time, fluidity, and compressive strength, while the pore structure was analyzed using mercury intrusion porosimetry (MIP). The hydration products and microstructures of LMWP were investigated by XRD, TG-DTG, and SEM-EDS. The results indicated that incorporating 1 % NaOH significantly enhanced the compressive strength of LMWP, whereas thermally activated MWP (800 ℃, 900 ℃) negatively affected compressive strength development. The addition of slag facilitated the reaction of MWP and improved the compressive strength of LMWP. When the slag incorporation reached 40 %, the specimen demonstrated optimal performance with a compressive strength of 27.8 MPa. The pore diameter was predominantly distributed around 10 nm, indicating well-structured porosity. Microstructural analysis revealed that the hydration products are dense calcium magnesium silicate gels (C-M-S-H), which significantly enhanced the compressive strength and optimized pore structure of LMWP. The efficiency of carbon emission reduction achieved by LMWP was evaluated. The findings indicate that, compared to traditional cement-based materials, LMWP reduces cement consumption by over 60 %, significantly decreasing CO2 emissions. This study innovatively utilizes MWP to prepare green and low-carbon geopolymer paste materials, with the aim of replacing cement applications in the construction industry, thereby reducing carbon emissions. It explores new avenues for the low-carbon and green development of the civil engineering sector and contributes to efforts in addressing the global climate crisis.
{"title":"Investigation of mechanical properties and hydration of low-carbon magnesium and calcium-rich waste powder geopolymer paste","authors":"Changming Li , Xudong Yang , Dongyang Jia , Shunbo Zhao , Guanfeng Liu , Yaozong Wang , Wanjiao Li , Wenyu Song","doi":"10.1016/j.jcou.2024.102984","DOIUrl":"10.1016/j.jcou.2024.102984","url":null,"abstract":"<div><div>Magnesium and calcium-rich waste powder (MWP) has the potential to be a low-carbon geopolymer cementitious material. This study investigates the mechanical properties and hydration products of low-carbon magnesium and calcium-rich waste powder geopolymer paste (LMWP). The influences of alkali content, calcination temperature, mix proportions of raw materials and curing temperature on the compressive strength and hydration of LMWP were examined. The mechanical properties of LMWP were systematically evaluated by assessing setting time, fluidity, and compressive strength, while the pore structure was analyzed using mercury intrusion porosimetry (MIP). The hydration products and microstructures of LMWP were investigated by XRD, TG-DTG, and SEM-EDS. The results indicated that incorporating 1 % NaOH significantly enhanced the compressive strength of LMWP, whereas thermally activated MWP (800 ℃, 900 ℃) negatively affected compressive strength development. The addition of slag facilitated the reaction of MWP and improved the compressive strength of LMWP. When the slag incorporation reached 40 %, the specimen demonstrated optimal performance with a compressive strength of 27.8 MPa. The pore diameter was predominantly distributed around 10 nm, indicating well-structured porosity. Microstructural analysis revealed that the hydration products are dense calcium magnesium silicate gels (C-M-S-H), which significantly enhanced the compressive strength and optimized pore structure of LMWP. The efficiency of carbon emission reduction achieved by LMWP was evaluated. The findings indicate that, compared to traditional cement-based materials, LMWP reduces cement consumption by over 60 %, significantly decreasing CO<sub>2</sub> emissions. This study innovatively utilizes MWP to prepare green and low-carbon geopolymer paste materials, with the aim of replacing cement applications in the construction industry, thereby reducing carbon emissions. It explores new avenues for the low-carbon and green development of the civil engineering sector and contributes to efforts in addressing the global climate crisis.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"90 ","pages":"Article 102984"},"PeriodicalIF":7.2,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-23DOI: 10.1016/j.jcou.2024.102978
Naser Monavari , Rahele Zhiani , Malihesadat Hosseiny , Susan Khosroyar , Zohreh Ebrahimi , Mina Moradi
In this study, we developed nano accelerators with a broad range by utilizing the interaction between tetraethyl orthosilicate (TEOS) and tripolyphosphate (TPP), followed by attaching poly(ionic liquids) to the click-modified ligand of fibrous phosphosilicate (FPS). This process led to the uniform distribution of poly(ionic liquids) without any aggregation, forming PILs-FPS. This material was then applied as a green catalyst for producing cyclic carbonate from limonene epoxide and CO2 under eco-friendly conditions. Subsequently, we synthesized a polymer from the natural cyclic carbonate obtained. The reaction between CO2 and highly substituted epoxides from sustainable sources like waste limonene produced novel bio-based cyclic carbonates. The reaction took place under mild, solvent-free conditions using PILs-FPS as the catalyst. The fibrous FPS structures enhanced adsorption capacity and facilitated the recovery of the catalyst without significant loss of activity. The products were easily separated from the environmentally conscious setting, and the catalyst was reused multiple times without a notable decrease in performance or selectivity.
{"title":"Fibrous phosphosilicate with highly dispersed poly(ionic liquids) as a nanocatalyst for production of biopolymer from limonene epoxide and CO2","authors":"Naser Monavari , Rahele Zhiani , Malihesadat Hosseiny , Susan Khosroyar , Zohreh Ebrahimi , Mina Moradi","doi":"10.1016/j.jcou.2024.102978","DOIUrl":"10.1016/j.jcou.2024.102978","url":null,"abstract":"<div><div>In this study, we developed nano accelerators with a broad range by utilizing the interaction between tetraethyl orthosilicate (TEOS) and tripolyphosphate (TPP), followed by attaching poly(ionic liquids) to the click-modified ligand of fibrous phosphosilicate (FPS). This process led to the uniform distribution of poly(ionic liquids) without any aggregation, forming PILs-FPS. This material was then applied as a green catalyst for producing cyclic carbonate from limonene epoxide and CO<sub>2</sub> under eco-friendly conditions. Subsequently, we synthesized a polymer from the natural cyclic carbonate obtained. The reaction between CO<sub>2</sub> and highly substituted epoxides from sustainable sources like waste limonene produced novel bio-based cyclic carbonates. The reaction took place under mild, solvent-free conditions using PILs-FPS as the catalyst. The fibrous FPS structures enhanced adsorption capacity and facilitated the recovery of the catalyst without significant loss of activity. The products were easily separated from the environmentally conscious setting, and the catalyst was reused multiple times without a notable decrease in performance or selectivity.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"90 ","pages":"Article 102978"},"PeriodicalIF":7.2,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-23DOI: 10.1016/j.jcou.2024.102981
Bo Xu, Yaolin Yi
Soil contamination poses an increasing challenge for global sustainable development. Traditional remediation methods, such as using ordinary Portland cement (OPC) for treating contaminated soils, are limited by high CO2 emissions, significant energy consumption, and natural resource depletion. A sustainable approach utilizing steel production waste (ladle slag, LS) to efficiently remediate copper (Cu)-contaminated soils was proposed in this study. The efficacy of this remediation using carbonation and conventional curing methods was compared. Cu-contaminated soils, spiked with varying initial concentrations, were treated with 10 % LS and subjected to both conventional and carbonation curing for different durations. Leaching behavior, strength development, and chemical and mineral properties of LS-remediated Cu-contaminated soils were assessed. The results demonstrated that both CO2 and conventional curing significantly reduced Cu leaching in contaminated soils by 4–5 orders of magnitude compared to untreated soils. CO2 curing achieved these reductions in a shorter time (56–72 hours) than conventional curing (28–56 days). Additionally, CO2 curing sequestered up to 8 % CO2 in the soils. However, higher Cu concentrations hindered carbonation reactions, lowering CO2 sequestration. While CO2 curing improved soil strength, increased initial Cu concentration diminished this effect. During CO2 curing, the formation of Ca- and Mg-carbonates contributed to microstructural densification and binding, thereby improving strength. These carbonates also encapsulated Cu, preventing its leaching. In contrast, the addition of Cu enhanced hydration reactions and improved the strength development of Cu-contaminated soils subjected to conventional curing. Conventional curing produced calcium aluminum silicate hydrate, which effectively bound soil particles, filled pores, and encapsulated Cu, reducing its leaching.
土壤污染对全球可持续发展构成了日益严峻的挑战。传统的修复方法，如使用普通硅酸盐水泥（OPC）处理受污染的土壤，受到二氧化碳排放量高、能源消耗大和自然资源枯竭的限制。本研究提出了一种利用钢铁生产废料（钢包渣）有效修复铜（Cu）污染土壤的可持续方法。研究比较了碳化法和传统固化法的修复效果。在不同初始浓度的铜污染土壤中添加了 10% 的 LS，并对其进行了不同持续时间的传统固化和碳化固化。对经 LS 修复的铜污染土壤的浸出行为、强度发展以及化学和矿物特性进行了评估。结果表明，与未经处理的土壤相比，二氧化碳固化和传统固化都能显著减少受污染土壤中的铜沥滤，减少幅度达 4-5 个数量级。与传统固化法（28-56 天）相比，二氧化碳固化法能在更短的时间内（56-72 小时）实现上述减少效果。此外，二氧化碳固化还在土壤中封存了高达 8% 的二氧化碳。然而，较高的铜浓度会阻碍碳化反应，从而降低二氧化碳的封存。虽然二氧化碳固化能提高土壤强度，但初始铜浓度的增加会降低这种效果。在二氧化碳固化过程中，Ca 和 Mg 碳酸盐的形成促进了微结构的致密化和结合，从而提高了强度。这些碳酸盐还能包裹铜，防止其沥滤。与此相反，添加 Cu 可增强水化反应，改善传统固化的铜污染土壤的强度发展。传统固化会产生硅酸铝钙水合物，它能有效地结合土壤颗粒、填充孔隙并包裹铜，从而减少铜的沥出。
{"title":"Comparison of the efficacy of carbonation and conventional curing for remediation of copper-contaminated soils by ladle slag","authors":"Bo Xu, Yaolin Yi","doi":"10.1016/j.jcou.2024.102981","DOIUrl":"10.1016/j.jcou.2024.102981","url":null,"abstract":"<div><div>Soil contamination poses an increasing challenge for global sustainable development. Traditional remediation methods, such as using ordinary Portland cement (OPC) for treating contaminated soils, are limited by high CO<sub>2</sub> emissions, significant energy consumption, and natural resource depletion. A sustainable approach utilizing steel production waste (ladle slag, LS) to efficiently remediate copper (Cu)-contaminated soils was proposed in this study. The efficacy of this remediation using carbonation and conventional curing methods was compared. Cu-contaminated soils, spiked with varying initial concentrations, were treated with 10 % LS and subjected to both conventional and carbonation curing for different durations. Leaching behavior, strength development, and chemical and mineral properties of LS-remediated Cu-contaminated soils were assessed. The results demonstrated that both CO<sub>2</sub> and conventional curing significantly reduced Cu leaching in contaminated soils by 4–5 orders of magnitude compared to untreated soils. CO<sub>2</sub> curing achieved these reductions in a shorter time (56–72 hours) than conventional curing (28–56 days). Additionally, CO<sub>2</sub> curing sequestered up to 8 % CO<sub>2</sub> in the soils. However, higher Cu concentrations hindered carbonation reactions, lowering CO<sub>2</sub> sequestration. While CO<sub>2</sub> curing improved soil strength, increased initial Cu concentration diminished this effect. During CO<sub>2</sub> curing, the formation of Ca- and Mg-carbonates contributed to microstructural densification and binding, thereby improving strength. These carbonates also encapsulated Cu, preventing its leaching. In contrast, the addition of Cu enhanced hydration reactions and improved the strength development of Cu-contaminated soils subjected to conventional curing. Conventional curing produced calcium aluminum silicate hydrate, which effectively bound soil particles, filled pores, and encapsulated Cu, reducing its leaching.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"90 ","pages":"Article 102981"},"PeriodicalIF":7.2,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The hydrogenation of CO2 remains one of the most intriguing and effective strategies for addressing the continuous increase of CO2 emissions in the atmosphere. At the same time, it serves as an effective pathway for the formation of value-added products. This work explores the Electrochemical Promotion of Catalysis (EPOC) phenomenon on the CO2 hydrogenation reaction, utilizing a single chamber reactor with a Pt/YSZ/Au electrochemical cell. Experiments were conducted under ambient pressure conditions, within a temperature range of 200–400 °C, for a reactant flow rate of 100 cm3/min under reducing (PCO2: PH2 = 1:7) and oxidizing (PCO2: PH2 = 2:1) conditions. The effect of reactant ratio, reactor temperature, and applied current/potentials on the reaction rate were thoroughly investigated. The only observed product was carbon monoxide through the Reverse Water Gas Shift Reaction (RWGS). Under purely catalytic operation of the cell (open circuit), reducing conditions were found to be more favorable for the RWGS reaction as compared to oxidizing ones. The imposition of negative potential values under reducing environment resulted in a 2.3-fold increase in the RWGS reaction rate (rCO = 21 × 10−9 mol/s) as compared to open circuit values (rCO = 9 × 10−9 mol/s). On the other hand, application of positive potentials had no profound effect on the catalytic rate, which was attributed to competing electrochemical and surface processes taking place on the catalyst electrode. The kinetic results are discussed in conjunction with the physicochemical and the morphological characteristics of the catalytic film.
{"title":"Unraveling the role of EPOC during the enhancement of RWGS reaction in a Pt/YSZ/Au single chamber reactor","authors":"Christos Chatzilias , Eftychia Martino , Alexandros K. Bikogiannakis , Georgios Kyriakou , Alexandros Katsaounis","doi":"10.1016/j.jcou.2024.102980","DOIUrl":"10.1016/j.jcou.2024.102980","url":null,"abstract":"<div><div>The hydrogenation of CO<sub>2</sub> remains one of the most intriguing and effective strategies for addressing the continuous increase of CO<sub>2</sub> emissions in the atmosphere. At the same time, it serves as an effective pathway for the formation of value-added products. This work explores the Electrochemical Promotion of Catalysis (EPOC) phenomenon on the CO<sub>2</sub> hydrogenation reaction, utilizing a single chamber reactor with a Pt/YSZ/Au electrochemical cell. Experiments were conducted under ambient pressure conditions, within a temperature range of 200–400 °C, for a reactant flow rate of 100 cm<sup>3</sup>/min under reducing (P<sub>CO2</sub>: P<sub>H2</sub> = 1:7) and oxidizing (P<sub>CO2</sub>: P<sub>H2</sub> = 2:1) conditions. The effect of reactant ratio, reactor temperature, and applied current/potentials on the reaction rate were thoroughly investigated. The only observed product was carbon monoxide through the Reverse Water Gas Shift Reaction (RWGS). Under purely catalytic operation of the cell (open circuit), reducing conditions were found to be more favorable for the RWGS reaction as compared to oxidizing ones. The imposition of negative potential values under reducing environment resulted in a 2.3-fold increase in the RWGS reaction rate (r<sub>CO</sub> = 21 × 10<sup>−9</sup> mol/s) as compared to open circuit values (r<sub>CO</sub> = 9 × 10<sup>−9</sup> mol/s). On the other hand, application of positive potentials had no profound effect on the catalytic rate, which was attributed to competing electrochemical and surface processes taking place on the catalyst electrode. The kinetic results are discussed in conjunction with the physicochemical and the morphological characteristics of the catalytic film.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"90 ","pages":"Article 102980"},"PeriodicalIF":7.2,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20DOI: 10.1016/j.jcou.2024.102977
Marcelo Echeverri , Eva M. Maya , Dulce M. Muñoz
Two families of heterogeneous porous catalysts based on iron or cobalt poly(azomethine) (PAM) networks were reported to synthesize cyclic carbonates from bio-based aliphatic oxides epoxides and carbon dioxide (CO2). The different PAM supports were prepared by reacting 2,6-pyridine dicarboxaldehyde with 1,3,5 tris(4 aminophenyl)benzene (PAM-1) or with melamine (PAM-2) by microwave activation. Both supports exhibited high thermal stability and similar CO2 uptake (1.3 mmol/g) but PAM-2 showed higher specific surface area (779 m2/g vs 401 m2/g), more crystallinity and less capacity for anchoring metals than PAM-1. The novel catalysts were used in the cycloaddition of CO2 to renewable feedstocks. Thus, using epoxidized methyl oleate (MOE) the corresponding cyclic carbonates were obtained with excellent yields (78–96 %) using a CO2 pressure of 7 bars, 120 ºC and 16 h of reaction. The best catalysts of the series, Fe@PAMs were also evaluated in the cycloaddition of CO2 to epoxidized soybean oil (ESBO) in the same condition reaction obtaining excellent performance, epoxide conversions and cyclic carbonate yields greater than 90 %.
{"title":"Formation of bio-based cyclic carbonates from CO2 and renewable feedstocks via porous poly(azomethine) -based heterogeneous catalysts approach","authors":"Marcelo Echeverri , Eva M. Maya , Dulce M. Muñoz","doi":"10.1016/j.jcou.2024.102977","DOIUrl":"10.1016/j.jcou.2024.102977","url":null,"abstract":"<div><div>Two families of heterogeneous porous catalysts based on iron or cobalt poly(azomethine) (PAM) networks were reported to synthesize cyclic carbonates from bio-based aliphatic oxides epoxides and carbon dioxide (CO<sub>2</sub>). The different PAM supports were prepared by reacting 2,6-pyridine dicarboxaldehyde with 1,3,5 tris(4 aminophenyl)benzene (PAM-1) or with melamine (PAM-2) by microwave activation. Both supports exhibited high thermal stability and similar CO<sub>2</sub> uptake (1.3 mmol/g) but PAM-2 showed higher specific surface area (779 m<sup>2</sup>/g vs 401 m<sup>2</sup>/g), more crystallinity and less capacity for anchoring metals than PAM-1. The novel catalysts were used in the cycloaddition of CO<sub>2</sub> to renewable feedstocks. Thus, using epoxidized methyl oleate (MOE) the corresponding cyclic carbonates were obtained with excellent yields (78–96 %) using a CO<sub>2</sub> pressure of 7 bars, 120 ºC and 16 h of reaction. The best catalysts of the series, Fe@PAMs were also evaluated in the cycloaddition of CO<sub>2</sub> to epoxidized soybean oil (ESBO) in the same condition reaction obtaining excellent performance, epoxide conversions and cyclic carbonate yields greater than 90 %.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"90 ","pages":"Article 102977"},"PeriodicalIF":7.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-19DOI: 10.1016/j.jcou.2024.102979
Xingyu Liu, Wei Yan
Electric arc furnace (EAF) steelmaking offers significant advantages in terms of low CO2 emissions, making it a promising avenue for achieving carbon peaking and carbon neutrality in the iron and steel industry. However, the conventional slag foaming practice through injection of fossil-based carbon (coal and coke) and oxygen still contributes most direct CO2 emissions to EAF steelmaking. Development of low-fossil carbon even fossil carbon-free slag foaming technology has presented a new opportunity to further decrease the CO2 emissions of EAFs. The present review systematically delves into the current advancements in EAF slag foaming processes to inspire and give valuable insights on near-zero CO2 emission slag foaming technology. The foaming slag theory and evaluation models were first summarized. And then the strengths and weaknesses of most of distinct slag foaming processes, namely the conventional carbon-oxygen injection slag foaming process, the slag foaming process utilizing waste plastics and rubber, biomass chars, carbonates and nitrates, and the exogenous gas injection slag foaming process, were reviewed and analyzed from perspectives of foamy mechanism and performance, reduction of CO2, industrial application and challenge. In general, the carbon-free exogenous gas injection or combined injection with biomass char exhibit the most promising potential among these slag foaming processes in terms of great CO2 reduction and even near-zero CO2 emission. Ultimately, the future prospects surrounding the development directions and industrial application challenge of low-CO2 and near-zero CO2 emission slag foaming technology were discussed and summarized.
{"title":"Current advances in slag foaming processes toward reduced CO2 emission for electric arc furnace steelmaking","authors":"Xingyu Liu, Wei Yan","doi":"10.1016/j.jcou.2024.102979","DOIUrl":"10.1016/j.jcou.2024.102979","url":null,"abstract":"<div><div>Electric arc furnace (EAF) steelmaking offers significant advantages in terms of low CO<sub>2</sub> emissions, making it a promising avenue for achieving carbon peaking and carbon neutrality in the iron and steel industry. However, the conventional slag foaming practice through injection of fossil-based carbon (coal and coke) and oxygen still contributes most direct CO<sub>2</sub> emissions to EAF steelmaking. Development of low-fossil carbon even fossil carbon-free slag foaming technology has presented a new opportunity to further decrease the CO<sub>2</sub> emissions of EAFs. The present review systematically delves into the current advancements in EAF slag foaming processes to inspire and give valuable insights on near-zero CO<sub>2</sub> emission slag foaming technology. The foaming slag theory and evaluation models were first summarized. And then the strengths and weaknesses of most of distinct slag foaming processes, namely the conventional carbon-oxygen injection slag foaming process, the slag foaming process utilizing waste plastics and rubber, biomass chars, carbonates and nitrates, and the exogenous gas injection slag foaming process, were reviewed and analyzed from perspectives of foamy mechanism and performance, reduction of CO<sub>2</sub>, industrial application and challenge. In general, the carbon-free exogenous gas injection or combined injection with biomass char exhibit the most promising potential among these slag foaming processes in terms of great CO<sub>2</sub> reduction and even near-zero CO<sub>2</sub> emission. Ultimately, the future prospects surrounding the development directions and industrial application challenge of low-CO<sub>2</sub> and near-zero CO<sub>2</sub> emission slag foaming technology were discussed and summarized.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"90 ","pages":"Article 102979"},"PeriodicalIF":7.2,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-16DOI: 10.1016/j.jcou.2024.102976
Dongliang Wang , Yun Du , Zuwei Liao , Xiaodong Hong , Shilong Zhang
This paper focuses on a liquid-phase CO2 hydrogenation process for methanol synthesis to enhance CO2 conversion. The feasibility of a liquid-phase CO2 hydrogenation process is comprehensively evaluated through a techno-economic analysis. The solvent tetraethylene glycol dimethyl ether is identified as one of the most favorable options following an analysis of the solubility data pertaining to various solvents and their influence on the reaction equilibrium of the substances within the system. The influence of process parameters, including temperature, pressure, solvent amount, and gas hourly space velocity (GHSV), on the conversion of CO2 and the selectivity for methanol is examined and optimized in a liquid-phase CO2 hydrogenation to methanol process without a gas recycle (Process 1), optimal reaction conditions are determined and a CO2 conversion of 95.19 % and a CH3OH yield of 94.77 % with a purity of 99.9 % are achieved. A liquid-phase process with a gas recycle (Process 2) is implemented to enhance the utilization of feed gas, achieving a CO2 conversion rate of 95.23 % and a methanol yield of 99.69 %. The liquid-phase process is further optimized by incorporating reactive distillation technology (Process 3), to enhance reaction efficiency and reduce energy consumption. Following the techno-economic evaluation, the energy efficiency of Process 3 is 7.79 % and 4.99 % higher than that of Process 1 and Process 2, respectively. The product cost of Process 3 is reduced by 8.75 % compared to Process 1 and by 4.25 % compared to Process 2. This research offers insights into the challenges associated with the development of the liquid-phase method.
{"title":"Liquid-phase CO2 hydrogenation to methanol synthesis: Solvent screening, process design and techno-economic evaluation","authors":"Dongliang Wang , Yun Du , Zuwei Liao , Xiaodong Hong , Shilong Zhang","doi":"10.1016/j.jcou.2024.102976","DOIUrl":"10.1016/j.jcou.2024.102976","url":null,"abstract":"<div><div>This paper focuses on a liquid-phase CO<sub>2</sub> hydrogenation process for methanol synthesis to enhance CO<sub>2</sub> conversion. The feasibility of a liquid-phase CO<sub>2</sub> hydrogenation process is comprehensively evaluated through a techno-economic analysis. The solvent tetraethylene glycol dimethyl ether is identified as one of the most favorable options following an analysis of the solubility data pertaining to various solvents and their influence on the reaction equilibrium of the substances within the system. The influence of process parameters, including temperature, pressure, solvent amount, and gas hourly space velocity (GHSV), on the conversion of CO<sub>2</sub> and the selectivity for methanol is examined and optimized in a liquid-phase CO<sub>2</sub> hydrogenation to methanol process without a gas recycle (Process 1), optimal reaction conditions are determined and a CO<sub>2</sub> conversion of 95.19 % and a CH<sub>3</sub>OH yield of 94.77 % with a purity of 99.9 % are achieved. A liquid-phase process with a gas recycle (Process 2) is implemented to enhance the utilization of feed gas, achieving a CO<sub>2</sub> conversion rate of 95.23 % and a methanol yield of 99.69 %. The liquid-phase process is further optimized by incorporating reactive distillation technology (Process 3), to enhance reaction efficiency and reduce energy consumption. Following the techno-economic evaluation, the energy efficiency of Process 3 is 7.79 % and 4.99 % higher than that of Process 1 and Process 2, respectively. The product cost of Process 3 is reduced by 8.75 % compared to Process 1 and by 4.25 % compared to Process 2. This research offers insights into the challenges associated with the development of the liquid-phase method.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"90 ","pages":"Article 102976"},"PeriodicalIF":7.2,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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