Carbon Dioxide Utilization Research Articles

Porous Flow of Energy and CO2 Transformation and Storage in Deep Formations: An Overview

The transformation and storage of energy and carbon dioxide in deep reservoirs include underground coal gasification, the underground storage of oil and gas, the underground storage of hydrogen, underground compressed air energy storage, the geological utilization and storage of carbon dioxide, etc [...]

Waterless Dyeing of Polyamide 6.6.

Waterless dyeing of polyamide 6.6 using scCO2 (supercritical carbon dioxide) was investigated. PA (polyamide) fibers can be dyed with various dyes, including disperse dyes. The conventional aqueous dyeing process uses large amounts of water and produces polluted water. Considering these environmental issues, waterless dyeing of fibers is a forefront issue, and utilization of supercritical carbon dioxide (scCO2) is a commercially viable technology for waterless dyeing. This study tested PA6.6 (polyamide 6.6) dyeing in scCO2 at 100 °C 220 bar pressure for 45 min. Color measurements and color fastness tests were performed, as well as tensile strength, scanning electron microscope (SEM) analysis, and Fourier transform infrared spectroscopy (FTIR) analysis. PA6.6 fabrics yielded higher K/S (color strength, the Kubelka-Munk equation) values with larger molecular weight dye and almost the same color strength with medium and small-sized dyes, demonstrating the ability of dyeing in a supercritical environment without water as a more environmentally friendly dyeing option compared to conventional dyeing.

Sustainable farms from a biogenic CO2 source: The CO2 management pig slurry strategy

Pig farmhouses face unprecedented challenges in meeting the growing demand to feed an increasing population. To do so, these farms contribute significantly to the production of approximately 35 % of the world’s NH3 emissions, a highly harmful air pollutant. In response to this critical environmental issue, the CO2 Management Pig Slurry Strategy (CO2-MPS) proposes an innovative solution to mitigate NH3 emissions by leveraging the biogenic CO2 produced within pig farmhouses. This groundbreaking Carbon Dioxide Utilization (CDU) approach based on utilizing this biogenic CO2 to form a protective blanket over pig manure lagoons promises the reduction of over 8 million metric tons of NH3 emissions annually. Such NH3 emissions are well-documented initiators of Particulate Matter, particularly PM2.5, highlighting the potential positive impact on air quality of this strategy.

Enhanced CO2 conversion with CH4 for greenfuel generation using coke-neutral nickel-loaded fibrous silica titania catalysts

This study reveals a groundbreaking advancement in utilizing carbon dioxide (CO2) for syngas production through methane (CH4) dry reforming using Fibrous Silica Titania (FST) as a support, loaded with different (1%, 3%, and 5%) nickel dosages. FST is distinguished by its fibrous structure, maintains a stable temperature, facilitates the confinement and dispersion of active metal, and is exceptionally effective at preventing carbon deposition. For a thorough examination of the new catalysts, characterization methods including XRD, FESEM, EDX mapping, N2 physisorption, FTIR-KBr, H2-TPR, and CO2-TPD were employed. Importantly, TEM lattice fringes verified the existence of XRD peaks and planes of Ni (111), Ni (200), and TiO2 (101). Aspects such as O-H stretching, Si-O-Si asymmetry, vibrations caused by external Si-OH groups, and Si-O-Si bending were identified using FTIR-KBr analysis. The study ingeniously identified the superior (3Ni/FST) catalyst, which exhibited moderate basicity sites on the CO2-TPD at approximately 350 °C. The catalyst converted nearly 100% CH4 at 750 °C with minimal coke production and 80% CO2 at 850 °C. Surprisingly, the 3Ni/FST catalyst demonstrated remarkable stability during a 72 h TOS stability test at 650 °C, effectively preventing coke-forming side reactions such as CO disproportionation, CO hydrogenation, CO2 and CH4 cracking with syngas ratio around unity and little coke production. The FST support exhibited exceptional attributes for low temperature carbon neutral CH4 reforming.

Study on CO2 co-gasification of cellulose and high-density polyethylene via TG-FTIR and ReaxFF MD

CO2 co-gasification of solid waste and biomass presents an approach for the comprehensive utilization of waste materials, biomass and carbon dioxide. In this study, the CO2 co-gasification of cellulose and high-density polyethylene was explored utilizing TG-FTIR method and ReaxFF MD simulation. The thermal behavior, synergistic effect, volatile release characteristics, activation energy and reaction mechanism were thoroughly analyzed. The experimental findings indicated that CO2 co-gasification involved four stages: drying, cellulose pyrolysis, polyethylene pyrolysis and semi-coke gasification. Co-gasification inhibited cellulose pyrolysis but promoted polyethylene pyrolysis, with the most pronounced promoting effect occurring at 40% polyethylene content. The absorbance curve suggested that CO release was associated with cellulose pyrolysis and the reaction between cellulose coke and CO2, and C-H release was related to the pyrolysis of cellulose and polyethylene. Co-gasification alleviated the energy barrier, with the greatest effect occurring at 40% polyethylene content. The simulated results confirmed that the promotion of polyethylene pyrolysis was attributed to the connection of radicals from cellulose with polyethylene. Additionally, the combination of hydrocarbon radicals and hydrogen from polyethylene and cellulose contributed to gas production. This investigation provides insights into the thermochemical conversion characteristics for CO2 co-gasification of biomass and high-density polyethylene.

Boosting Formate Electrooxidation by Heterostructured PtPd Alloy and Oxides Nanowires.

Direct formate fuel cells (DFFCs) receive increasing attention as promising technologies for the future energy mix and environmental sustainability, as formate can be made from carbon dioxide utilization and is carbon neutral. Herein, heterostructured platinum-palladiumalloy and oxides nanowires (PtPd-ox NWs) with abundant defect sites are synthesized through a facile self-template method and demonstrated high activity toward formate electrooxidation reaction (FOR). The electronic tuning arising from the heterojunction between alloy and oxides influence the work function of PtPd-ox NWs. The sample with optimal work function reveals the favorable adsorption behavior for intermediates and strong interaction in the d-p orbital hybridization between Pt site and oxygen in formate, favoring the FOR direct pathway with a low energy barrier. Besides the thermodynamic regulation, the heterostructure can also provide sufficient hydroxyl species to facilitate the formation of carbon dioxide due to the ability of combining absorbed hydrogen and carbon monoxide at adjacent active sites, which contributes to the improvement of FOR kinetics on PtPd-ox NWs. Thus, heterostructured PtPd-ox NWs achieve dual regulation of FOR thermodynamics and kinetics, exhibiting remarkable performance and demonstrating potential in practical systems.

One-Step Production of Highly Selective Ethylbenzene and Propylbenzene from Benzene and Carbon Dioxide via Coupling Reaction

Utilizing carbon dioxide as a carbon source for the synthesis of olefins and aromatics has emerged as one of the most practical methods for CO2 reduction. In this study, an improved selectivity of 85% for targeting products (ethylbenzene and propylbenzene) is achieved with a benzene conversion of 16.8% by coupling the hydrogenation of carbon dioxide to olefins over the bifunctional catalyst “Oxide-Zeolite” (OX-ZEO) and the alkylation of benzene with olefins over ZSM-5. In addition to investigating the influence of SAPO-34 and ZSM-5 zeolite acidity on product distribution, catalyst deactivation due to coke formation is addressed by modifying both molecular sieves to be hierarchical to extend the catalyst lifespan. Even after 100 h of operation at 400 °C, the catalysts maintained over 80% selectivity towards the target products, with benzene conversion over 14.2%. Furthermore, the pathway of propylbenzene formation is demonstrated through simple experimental design, revealing that the surface Brønsted acid sites of SAPO-34 serve as its primary formation sites. This provides a novel perspective for further investigation of the reaction network.

Practical method in the diagnosis of diabetic ketoacidosis: end-tidal carbon dioxide

Objectives: Diabetic ketoacidosis (DKA) poses a life-threatening risk in uncontrolled diabetes. Current diagnostic criteria rely on invasive measures, leading to potential delays in treatment initiation. This study aimed to assess the diagnostic utility of noninvasive end-tidal carbon dioxide (EtCO2) measurements in DKA patients. Methods: A prospective, cross-sectional study was conducted in a tertiary-level Emergency Medicine Clinic from January 2021 to January 2023. Participants included adults with DKA symptoms and those with stable vital signs as controls. EtCO2 levels were measured using a capnograph device. Diagnostic criteria for DKA were blood glucose ≥250 mg/dL, ketonuria, ketonemia, and metabolic acidosis (pH<7.3 or bicarbonate <15 mEq/dL). Statistical analysis was performed using SPSS Statistics. Results: Of 730 participants, 120 had DKA, 410 did not, and 200 served as controls. EtCO2 levels significantly differed between DKA, non-DKA, and control groups (P<0.05). EtCO2 correlated with pH, lactate, base deficit, and bicarbonate (P<0.05). ROC analysis showed an AUC of 0.86 for EtCO2 in diagnosing DKA (P<0.01), with 91.67% sensitivity and 74.39% specificity at a cut-off value 23.7. Conclusion: This study suggests that EtCO2 measurement is a valuable noninvasive tool for diagnosing and assessing the severity of DKA in the emergency department. An EtCO2 threshold of <23.7 could prompt consideration of DKA in patients with elevated blood glucose levels. More extensive multicenter studies are warranted to validate these findings further. EtCO2 measurement could facilitate early DKA diagnosis and improve patient outcomes.

Carbon dioxide hydrogenation to methanol by flame-deposited CuO/ZrO2-polymer membrane reactors

Carbon dioxide hydrogenation for methanol synthesis, within the framework of carbon dioxide utilization represents a promising strategy. Nevertheless, high conversion of carbon dioxide into methanol presents significant challenges, primarily arising from thermodynamic constraints and catalyst deactivation due to the formation of water as a by-product. In response to these challenges, this investigation focused on the development of an innovative hybrid catalytic membrane reactor utilizing flexible polymeric membranes with flame-made catalysts. The nanostructured CuO/ZrO2 thin layers were synthesized by flame spray pyrolysis and directly deposited on two polyimide polymers and polybenzimidazole membranes. The CuO/ZrO2-polymer membranes are reduced by H2 at 300 °C resulting in Cu/ZrO2-polymer nanocomposites. This novel hybrid membrane design facilitated the efficient separation of by-product water from the reaction environment, effectively promoting carbon dioxide conversion and ultimately leading to enhanced methanol production rate. At 200 °C and 20 bar, these catalytic membrane reactors demonstrate exceptional performance, achieving 113 % improvement in carbon dioxide conversion and a remarkable 106 % increase in methanol production rate compared to conventional catalytic fixed bed reactors. Overall, the catalytic membrane, synthesized using flame spray pyrolysis, has shown long-term stability and ability to suppress catalyst deactivation caused by water, ensuring sustained catalyst stability throughout the reaction.

High-efficient carbon dioxide-to-formate conversion on Bi5O7NO3 by tuning the exposure of crystal plane during reconstruction in electrolysis

The electrochemical conversion of carbon dioxide into formic acid offers an effective approach for utilizing carbon dioxide resources. Bismuth (Bi)-based catalysts have garnered significant attention in this field. However, designing high-performance Bi-based catalysts is challenging due to difficulties in accurately adjusting the reconstruction of such catalysts during electrolysis. In this study, we reported that nitrate ions positively influence the reconstruction of Bi5O7NO3 (BON), thereby outperforming Bi2O3 during ECO2RR. BON attained a Faraday efficiency of formate (FEHCOOH) and partial current density of 95.3 % and 25.1 mA/cm2 at −0.9 V vs RHE, respectively, surpassing the performance of Bi2O3 (90.2 % and 15.4 mA/cm2). The layered structure of BON mitigates Bi agglomeration during electrolysis, thus providing a large number of active sites. The presence of nitrate ions promotes exposure to abundant Bi(110) and Bi(015), whereas only the Bi(012) plane forms in Bi2O3 during electrolysis. In-situ ATR FTIR results indicate that both BON and Bi2O3 follow the same pathway for formate formation. Nevertheless, the high-index planes (015) cause the Bi derived from BON to remain in an electron defect state, which increases the adsorption of *CO2. In addition, Bi(110) plane has effectively lower the energy barriers for *OCHO production than Bi(012) plane. The Bi(015) and Bi(110) planes enhance the adsorption of *CO2 intermediates and reduce the energy barrier for *OCHO formation, respectively, which contributes to the improved ECO2RR activity of BON.

From the Photosynthesis to Hormone Biosynthesis in Plants.

Land plants produce glucose (C6H12O6) through photosynthesis by utilizing carbon dioxide (CO2), water (H2O), and light energy. Glucose can be stored in various polysaccharide forms for later use (e.g., sucrose in fruit, amylose in plastids), used to create cellulose, the primary structural component of cell walls, and immediately metabolized to generate cellular energy, adenosine triphosphate, through a series of respiratory pathways including glycolysis, the tricarboxylic acid cycle, and oxidative phosphorylation. Additionally, plants must metabolize glucose into amino acids, nucleotides, and various plant hormones, which are crucial for regulating many aspects of plant physiology. This review will summarize the biosynthesis of different plant hormones, such as auxin, salicylic acid, gibberellins, cytokinins, ethylene, and abscisic acid, in relation to glucose metabolism.

Supercritical Carbon Dioxide Extraction of Citronella Oil Review: Process Optimization, Product Quality, and Applications

This review paper explores the utilization of supercritical carbon dioxide (SC-CO2) extraction to isolate citronella oil, delving into its multifaceted dimensions, including process optimization, product quality enhancement, and diverse potential applications. Citronella oil, renowned for its myriad bioactive compounds with demonstrated health benefits, is a coveted essential oil in the pharmaceutical, cosmetics, and food industries. The transition from traditional extraction techniques to SC-CO2 extraction presents a paradigm shift due to its manifold advantages, such as heightened yield rates, expedited extraction durations, and elevated product quality. However, the efficacy of SC-CO2 extraction is intricately interwoven with an array of parameters encompassing pressure, temperature, flow rate, particle size, and co-solvent ratios. Accordingly, meticulous process optimization is indispensable in achieving the desired product quality while maximizing yield. Furthermore, the paper explores the extensive spectrum of potential applications for citronella oil, extending its reach into formulations with antimicrobial, insecticidal, and antioxidant properties. These applications underscore the versatility and commercial appeal of citronella oil. The review establishes SC-CO2 extraction of citronella oil as a promising and sustainable alternative to conventional extraction methodologies, offering myriad applications across the pharmaceutical, cosmetics, and food sectors. This scholarly work provides valuable insights into the intricacies of process optimization and product quality. It outlines future perspectives and avenues for further exploration in SC-CO2 extraction of citronella oil.

Transition of chemical production pattern motivated by CO2 utilization: Multi-dimensional evaluation and future projections

Carbon dioxide utilization (CDU) for chemical production is beneficial for achieving carbon neutrality and constructing an artificial carbon cycle. However, the industrialization of CDU technology is facing the concerns about environmental impacts, energy consumption and economic effects. To better illustrate the comprehensive performances of CDU technology and optimize chemical production, this study conducts a multi-dimensional evaluation on CDU and traditional pathways following a scenario-based optimization, which covers 23 pathways for 7 identified bulk chemicals. The results reveal that ethanol is the most suitable chemical to be transitioned preferentially and produced with CDU technology based on China’s current technology level. The development of electro-catalytic conversion may benefit CDU pathways especially for oxirane. The results of scenario analysis reveal that the competitivity and priority of various pathways may change significantly with the deployment of low-carbon strategies. Then the results of conditional optimization reveal that the transition of chemical production pattern motivated by CDU may significantly impact on resource consumption and technology proportion, which brings about an increase of 680 % in H2 consumption. The transition may also decouple the relationship between carbon emissions and economic growth, which drives the production emissions to drop from 193 Mt/year to −27 Mt/year and carbon intensity to drop from 80 t/104 USD to −8 t/104 USD.

Overcoming equilibrium constraints in the reverse water gas shift with counter-current gas–solid flow and oxygen transport in La0.75Sr0.25Cr0.5Mn0.5O3-δ

Utilizing carbon dioxide in the reverse water gas shift (RWGS) reaction (CO2+H2→CO+H2O) is a potential pathway for mitigating CO2 emissions, as the resulting CO can be used to produce valuable products, such as chemicals and fuels. Here, we explore the implementation of the RWGS reaction by solid-oxide redox cycling in a two-reactor moving-bed process with counter-current gas–solid flow. We also develop a method for obtaining design diagrams from the thermodynamic data of the solid oxide utilized for redox cycling. Using this tool and screening the previous literature for relevant thermodynamic data, we identify the perovskite La0.75Sr0.25Mn0.5Cr0.5O3-δ as a highly promising candidate material, and we experimentally determine its non-stoichiometry under conditions relevant for the RWGS. The reaction kinetics are also obtained for its reduction in H2 and its reoxidation in CO2. We observe that the inward diffusion of oxygen into the perovskite grains during reoxidation in CO2 is likely to determine the minimum feasible temperature at which this process can be operated, and we estimate an effective diffusion coefficient of D = 7.7−1.4+1.8 *10−14 cm2 s−1 at T = 550 °C, with an activation energy of 122±4.4 kJ mol−1. Implementing the RWGS with this material in counter-current gas–solid flow is expected to significantly improve the RWGS process by decreasing the operating temperature, enabling continuous gas production, and increasing the gas conversion.

Facile Utilization of Carbon Dioxide for the Esterification of Potassium Lactate to Butyl Lactate

Facile Utilization of Carbon Dioxide for the Esterification of Potassium Lactate to Butyl Lactate

Two-Dimensional Nanoporous Cross-linked Polymer Networks as Emerging Candidates for Gas Adsorption.

This paper illustrates the gas adsorption properties of newly synthesized nanoporous cross-linked polymer networks (CPNs). All synthesized CPNs possess N-rich functional groups and are used for the utilization of carbon dioxide and methane. Good gas adsorption and selectivities are obtained for all of the samples. Among the materials, HEREON2 outperforms better selectivity for methane separation from nitrogen rather than zeolites, activated carbons, molecular sieves, covalent organic frameworks, and metal-organic frameworks (MOFs). The accessibility of the N-rich functionalities makes these materials potential candidates for the separation of hydrocarbons via increased polarizabilities. High-pressure adsorption experiments showed that the synthesized two-dimensional nanoporous materials also have a high affinity toward carbon dioxide. HEREON2 powders showed an increased experimental CO2/N2 selectivity of ∼25,000 at 50 bar due to the presence of nitrogen groups in the structure. Fourier-transform infrared spectroscopy (FTIR), solid-state NMR, X-ray diffraction, thermogravimetric analysis, energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were applied for the characterization of the synthesized nanoporous CPNs. The results show a potential new pathway for future CPN membrane development.

Utilisation of carbon dioxide in the synthesis of multifunctional AB-type carbonated hydroxyapatite compositions

Carbon dioxide utilisation is a rapidly growing field that aims to reduce the magnitude of anthropogenic greenhouse gas emissions by using CO2 captured from point sources in the production of useful materials. AB-type carbonated hydroxyapatites containing 2.28–10.35 wt% of carbonate were synthesised in this work via aqueous precipitation reaction, with carbonate ions introduced by bubbling CO2 gas into water used in the reaction. Analysis of FTIR spectra demonstrated that carbonate ions had substituted onto both hydroxyl and phosphate sites. An AB-type carbonated hydroxyapatite with a carbonate content of 14.68 wt% was obtained after an hourlong heat treatment in dry CO2 at 600 °C, a very large degree of carbonation for such a material. Poor thermal stability of this material however meant that a full structural determination from refinement of XRD data could not be carried out. Additionally, further work is required to test the prepared materials in fields including carbon capture and wastewater treatment before this can truly be considered a viable route for carbon dioxide utilisation.

CO2-facilitated upcycling of polyolefin plastics to aromatics at low temperature.

Plastics are one of the most produced synthetic materials and largest commodities, used in numerous sectors of human life. To upcycle waste plastics into value-added chemicals is a global challenge. Despite significant progress in pyrolysis and hydrocracking, which mainly leads to the formation of pyrolysis oil, catalytic upcycling to value-added aromatics, including benzene, toluene and xylene (BTX), in one step, is still limited by high reaction temperatures (>500°C) and a low yield. We report herein CO2-facilitated upcycling of polyolefins and their plastic products to aromatics below 300°C, enabled by a bifunctional Pt/MnOx-ZSM-5 catalyst. ZSM-5 catalyzes cracking of polyolefins and aromatization, generating hydrogen at the same time, while Pt/MnOx catalyzes the reaction of hydrogen with CO2, consequently driving the reaction towards aromatization. Isotope experiments reveal that 0.2kg CO2 is consumed per 1.0kg polyethylene and 90% of the consumed CO2 is incorporated into the aromatic products. Furthermore, this new process yields 0.63kg aromatics (BTX accounting for 60%), comparing favorably with the conventional pyrolysis or hydrocracking processes, which produce only 0.33kg aromatics. In this way, both plastic waste and the greenhouse gas CO2 are turned into carbon resources, providing a new strategy for combined waste plastics upcycling and carbon dioxide utilization.

Random Terpolymer of Carbon Dioxide, Butadiene and Epoxides: Synthesis, Functionalization and Degradability

Comprehensive SummaryThe utilization of carbon dioxide (CO2) as a C1 feedstock is consistently attractive, especially in the preparation of sustainable polymeric materials. In this contribution, a terpolymer of CO2, 1,3‐butadiene (BD) and epoxide is synthesized by scandium triflate catalyzed cationic ring‐opening copolymerization of α‐ethylidene‐δ‐vinyl‐δ‐valerolactone (EVL), an intermediate derived from CO2 and BD, with epoxides. The obtained terpolymer with a CO2 content of 22 mol% has a number‐average molecular weight (Mn) up to 7.8 kg/mol and a dispersity (Đ) of 2.4. The reactivity ratios of EVL and cyclohexene oxide (CHO) are determined as 0.01 and 1.07, respectively, suggesting random characteristic of the terpolymer. The preserved C=C double bonds from BD allow for the further modification of the terpolymer by photoinitiated crosslinking. The yielded networks are fluorescent and degradable. This method offers enhanced versatility to the synthesis and additional functionalization of CO2‐based polymers.

A new perspective on hydrogenation of CO2 into methanol over heterogeneous catalysts

The utilization of carbon dioxide is critical to realize the objective of "carbon peak and neutrality". Among various carbon dioxide exploitation approaches, catalytic hydrogenation of carbon dioxide is a significant method to selectively convert the CO2 into methanol and other valuable chemicals. Among these products, methanol is a crucial chemical feedstock that can be utilized as a platform molecule for the synthesis of chemicals and fuels as well as a fuel for internal combustion engines and fuel cells, causing particular interest. Nowadays, Catalytic hydrogenation of carbon dioxide into methanol has shifted its focus on the creation of low-cost, environmentally friendly, and efficient catalysts. Inspired of this, we have concluded the mechanism of catalytic hydrogenation of carbon dioxide, and reviewed the research progress of multiple heterogeneous catalysts with high catalytic application prospect, especially the supported catalysts.