Incorporation Of Carbon Dioxide Research Articles

Silver-catalyzed carbon dioxide incorporation into propargylic amides

Abstract A method for the synthesis of oxazolidine-2,4-diones by silver-catalyzed CO2 incorporation into propargylic amides under base-free mild reaction conditions was developed. These conditions were applied to a variety of aryl- and alkyl-substituted propargylic amides to afford the corresponding oxazolidine-2,4-diones in high yields. Combined with iodination during the CO2 incorporation reaction, the present reaction was successfully applied to the synthesis of the pesticide pentoxazone.

Effect of spontaneous degradation of ion-selective optodes receptor materials on sensors performance. Where is the catch?

Interest in application of biodegradable polymers as matrix for ion-selective sensors, including optodes is likely to increase. However, finding an alternative for plasticized poly(vinyl chloride) or polyacrylates, requires among others consideration if spontaneous changes in these materials affect the analytical performance of sensors. In this work we study ion-selective optodes prepared using biodegradable matrix: p-polycaprolactone and acetyl tributyl citrate using classical constituents: optically silent ionophore and chromoionophore as optical transducer. The effect of spontaneous changes of sensor constituents on its performance was studied. It was confirmed that hydrolysis of receptor is occurring leading to change of the matrix composition. Surprisingly it was found that the key factor affecting performance of sensor is spontaneous transformation of the dye embedded within it, typically considered as stable within the sensor matrix. N-octadecanoyl-Nile blue, i.e. chromoionophore I, undergoes acidic hydrolysis leading to formation of Nile blue and Nile red, and ultimately resulting in decreased sensor performance. The hydrolysis of chromoionophore in plasticized polycaprolactone matrix is significantly affected by incorporation of carbon dioxide to the solution containing nanoprobes. As model sensors hydrogen or potassium ions selective optodes were tested.

In-situ formation of CO2-incorportaed solid sorbent for dispersive solid phase extraction of phenolic compounds from water and wastewater samples prior to gas chromatography-flame ionization detector

BackgroundHerein, a new extraction procedure based on in-situ formation of carbon dioxide-incorporated solid sorbent was introduced for dispersive solid phase extraction of phenolic compounds from aqueous samples. In this study, incorporation of carbon dioxide into the structure of a diamine led to the formation of a solid compound in the sample solution that adsorbed the analytes. ResultsThe sample solution was mixed with isophorone diamine and placed under carbon dioxide stream. By doing so, isophorone diamine reacted with carbon dioxide and produced a carbamic acid analogue. It was dispersed into the sample solution as tiny particles that adsorbed the analytes. The adsorbed analytes were eluted by a volatile organic solvent and concentrated more by the vaporization of the eluate. The extraction procedure was done at low temperature to limit the releasing carbon dioxide from the produced compound. To obtain the reliable results, the method was validated and the obtained limits of detection and quantification were in the ranges of 0.29–41 and 0.96–1.3 ng/mL, respectively. Acceptable relative standard deviation (≤7.3%) and coefficient of determination (≥0.994) values confirmed the method repeatability and linearity. High enrichment factors (410–435) and extraction recoveries (82–87%) were attained with the introduced method. Significance and noveltyIn this work, a chemical reaction was done between isophorone diamine and carbon dioxide in solution. The produced product (sorbent) was insoluble in solution and dispersed in whole parts of the solution as tiny particles. A high contact area between the sorbent and analytes provided high extraction efficiency for the analytes. The method was successful utilized in determining target analytes in real samples and the matrix effect of the samples had no important effect on the obtained results.

Unraveling the thermodynamics of the CO2 driven precipitation of cellulose in aqueous NaOH

Hypothesis:The incorporation of carbon dioxide into a sodium hydroxide solution containing cellulose may induce the formation of a transient cellulose carbonate intermediate, which readily hydrolyzes to carbonate ion, and this process is responsible for the instantaneous formation of loose cellulose aggregates. Simulations:We employed molecular dynamics simulations to gain insight into the role of carbon dioxide and related ions in the cellulose aggregation process. By performing free energy calculations using OPLS/AA force fields between cellulose chains at different ionic environments, we were able to gain additional information regarding the behavior and thermodynamics of the involved species and propose a potential mechanism for the aggregation of cellulose in these systems. Findings:Our hypothesis of the formation of an intermediate cellulose carbonate in the solution, which strongly favors carbon dioxide absorption and carbonate ion formation, is supported by the simulation results. These results suggest that the aggregation process is driven by entropy upon the introduction of carbonate ions into the system.

Methane and Carbon Dioxide Separation Characteristics of Quaternary Ammonium Salt Hydrates for Biogas Upgrading under Static Conditions of Gas–Solid Contact

This report describes the methane and carbon dioxide separation characteristics of stoichiometric quaternary ammonium salt (QAS) hydrates for gas–solid contact with simulated biogas (CH4, 0.613 mol fraction; CO2, 0.387 mol fraction). Tests for elucidating the separation characteristics were conducted using tetra-n-butylammonium fluoride (TBAF), tetra-n-butylammonium chloride (TBAC), and tetra-n-butylammonium bromide (TBAB) hydrates as solid phases. To ascertain system temperature and pressure effects on their gas separation performance, the tests were conducted at 253–293 K under the initial fed pressures of 3.0 and 0.9 MPa. The gas–solid contact between the simulated biogas with 0.387 mol fraction of CO2 and the QAS hydrates reduced CO2 in the gas phase to 0.26–0.37 mol fraction and enriched CO2 in the hydrate phases to 0.54–0.89 mol fraction. All QAS hydrates showed selective incorporation of carbon dioxide into the hydrate phase. Under all comparable conditions, TBAC hydrate exhibited the highest separation factor (15.2 ± 3.0 under initial pressure of 3.0 MPa at 253 K and 13.9 ± 2.5 under initial pressure of 0.9 MPa at 253 K), indicating that TBAC hydrate had the highest CO2 separation performance for biogas upgrading among the QAS hydrates we examined. At the same initial pressure, high gas separation performance was shown for low-temperature ranges. The separation factors of the QAS hydrates were maintained or improved by lowering the initial pressure at the same contact temperature, suggesting that the separation performance of the QAS hydrates, even at lower pressures, was nearly equal to or better than that achieved at higher pressures. The results contrasted against those reported for tetrahydrofuran hydrate, for which the separation factor decreases with lower initial pressure. The use of the QAS hydrates is expected to lower a system’s operating pressure without compromising separation performance.

One-pot terpolymerization of CHO, CO2 and L-lactide using chloride indium catalysts.

Ring-opening copolymerization reactions of epoxides, carbon dioxide and cyclic esters to produce copolymers is a promising strategy to prepare CO2-based polymeric materials. In this contribution, bimetallic chloride indium complexes have been developed as catalysts for the copolymerization processes of cyclohexene oxide, carbon dioxide and L-lactide under mild reaction conditions. The catalysts displayed good catalytic activity and excellent selectivity towards the preparation of poly(cyclohexene carbonate) (PCHC) at one bar CO2 pressure in the absence of a co-catalyst. Additionally, polyester-polycarbonate copolymers poly(lactide-co-cyclohexene carbonate) (PLA-co-PCHC) were obtained via an one-pot one-step route without the use of a co-catalyst. The degree of incorporation of carbon dioxide can be easily modulated by changing the CO2 pressure and the monomer feed, resulting in copolymers with different thermal properties.

Development of Carbon Dioxide Incorporation Reactions for Fine Chemicals Synthesis

Development of Carbon Dioxide Incorporation Reactions for Fine Chemicals Synthesis

Recent Advancements in Metal‐catalysts Design for CO2/Epoxide Reactions

AbstractCarbon dioxide utilization is considered an effective strategy to mitigate the carbon footprint of chemical industry. Among other uses, the incorporation of carbon dioxide into cyclic organic carbonates (COCs) and aliphatic polycarbonates (APCs) has received great attention in the field of homogeneous catalysis. After few decades of research activity, a wide range of metal‐based catalytic systems has been reported to promote this reaction. Nonetheless, a better comprehension of the apparently simple reaction mechanism of such transformations has been reached only in recent years. This, in turn, allowed for the design of new catalytic systems guided by a clearer mechanistic picture. In this review, we present the most recent advancements in this field, distinguishing between catalysts for COCs and APCs production classified on the bases of their ligand structures.

Thermodynamic analysis of hydrocarbon reforming

A holistic hydrocarbon reforming analysis is performed using equilibrium calculations based on Gibbs energy minimization. The reforming feed composition is defined based on the oxygen to carbon atom ratio and the hydrogen to carbon atom ratio. The coke formation, carbon dioxide yield, and synthesis gas mole fraction were investigated to determine an operating composition region for hydrocarbon reforming while the hydrogen yield, hydrogen to carbon monoxide ratio, and the stoichiometric ratio were investigated to determine the reforming feed composition to produce hydrogen and optimal synthesis gas compositions for downstream processes. Our findings show that the synthesis of hydrogen via the reforming process will result in carbon dioxide emissions for any hydrocarbon feed. To produce the optimal synthesis gas for oxo-synthesis, Fischer-Tropsch synthesis and methanol synthesis, our findings show that reforming with methane provides the best opportunity for incorporation of carbon dioxide, while the reforming of coke does not result in the incorporation of carbon dioxide.

Enhancing the phi-meter by incorporating carbon dioxide measurement

This paper describes the development, calibration and experimental application of an enhanced equivalence ratio measurement apparatus, or ‘phi-meter’. The original phi-meter developed by Babrauskas et al. used only an oxygen analyser and chemically removed the CO2. In this study, an enhanced phi-meter was developed to measure the equivalence ratio from experimental enclosure fires by O2 and CO2 measurements. As with all combustion calorimetry, the accuracy of the results increases with the number of species being directly measured and removing the need for chemical removal of the CO2 is an advantage. This is of practical importance as scrubbing agent required to remove CO2 from the combustion products requires careful handling and increases test costs. Moreover, in severely under-ventilated conditions, the production of CO significantly increases, and its measurement by phi-meter provides real-time validation of the occurrence of complete combustion within the phi furnace. The original equations derived for the phi-meter incorporated the depletion of oxygen, whereas the phi-meter equations developed in this paper incorporate O2 and CO2 measurements. The equivalence ratios measured in compartment fires for heptane, LPG and timber crib fuels ranging from 0.2 for oxygen-rich to 3.0 for fuel-rich conditions are found to agree with theoretical values.

Incorporating carbon dioxide into a stoichiometric producer-grazer model.

Climate change models predict increases in atmospheric carbon dioxide concentration. As ecosystems equilibrate with the atmosphere, stimulation of photosynthesis is expected to occur. However, growth limitation due to soil nutrients may potentially limit sequestration of carbon. Additionally, changes in producer nutritional quality may cause a decline in grazer populations. Here we extend the WKL model to allow for consideration of the impacts of elevated atmospheric carbon dioxide concentration on producer-grazer dynamics. We do so by explicitly tracking the free carbon in the medium and allowing the producer's growth rate to be limited by available carbon instead of light. This model is analyzed using primarily local bifurcation analysis. Overall, these analyses show that carbon sequestration due to increased atmospheric carbon dioxide can be limited by insufficient available phosphorus. Furthermore, increased atmospheric carbon dioxide will cause decreased stoichiometric quality of producers where available phosphorus is limiting.

FTIR investigation of the interfacial properties and mechanisms of CO2 sorption in porous ionic liquids

Porous liquids, which are liquids with permanent porosity, have received significant attention as a new class of materials with the potential for far-reaching impacts in a variety of applications including gas separation. In this work, in situ Fourier transform infrared spectroscopy measurements were conducted to investigate the mechanism of carbon dioxide absorption in a porous ionic liquid consisting of ZIF-8 combined with 8,8′-(3,6-dioxaoctane-1,8-diyl)bis(1,8-diazabicyclo[5.4.0]undec-7-en-8-ium) bis(trifluoromethanesulfonyl)imide ([DBU-PEG][(Tf2N)2]). While the vibrational modes of the pure ionic liquid remain relatively unchanged, the incorporation of carbon dioxide leads to slight structural fluctuations in the ZIF-8 framework whether it is pure solid or as integrated into the porous ionic liquid. The analysis of the vibrational modes of the porous ionic liquid suggests that the interaction of the CO2 occurs more strongly with the ring structure of the ZIF-8 framework. The splitting of the asymmetric stretch of the CO2 into multiple peaks upon sorption indicate the presence of multiple environments, which could be a combination of free and physisorbed CO2 or simply multiple binding sites within the porous ionic liquid. A better understanding of gas sorption mechanisms in this unique material could lead to new porous ionic liquids with enhanced separations properties.

Synthesis of 1,3-oxazine-2,4-diones by DBU-catalyzed incorporation of carbon dioxide into 3-ynamides

A new process for the utilization of carbon dioxide to give high value added 1,3-oxazine-2,4-diones is presented. It is based on the catalytic carboxylative heterocyclization of readily available 3-ynamides, using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as organocatalyst. The reaction, which takes place under relatively mild conditions [80 °C for 15 h in a 3:1 mixture (v/v) of MeCN-HC(OMe)3, under 30 atm of CO2] proceeds through an ordered sequence of steps, involving substrate deprotonation by DBU, nucleophilic attack to CO2, 6-exo-dig cyclization, and isomerization, to give the final products in 44–85 % yields over 16 examples.

Bubble size distribution and stability of CO2 microbubbles for enhanced oil recovery: effect of polymer, surfactant and salt concentrations

Fluids incorporating carbon dioxide (CO2) microbubbles have been utilized to promote enhanced oil recovery from hydrocarbon reservoirs. The performance of such fluids in porous media is greatly affected by both the bubble size and stability. On this basis, the present study evaluated the effects of varying the concentrations of a xanthan gum (XG) polymer, a surfactant (sodium dodecyl sulfate: SDS) and sodium chloride (NaCl) on both the stability and bubble size distribution (BSD) of CO2 microbubbles. CO2 microbubble dispersions were prepared using a high-speed homogenizer in conjunction with the diffusion of gaseous CO2 through aqueous solutions. The stability of each dispersion was ascertained using a drainage test, while the BSD was determined by optical microscopy and fitted to either normal, log-normal or Weibull functions. The results showed that a Weibull distribution gave the most accurate fit for all experimental data. Increases in either the SDS or XG polymer concentration were found to decrease the microbubble size. However, these same changes increased the microbubble stability as a consequence of structural enhancement. The addition of NaCl up to a concentration of 10 g/L (10 g/1000g) decreased the average bubble size by approximately 2.7%. Stability was also reduced as the NaCl concentration was increased because of the gravitational effect and coalescence.

Electrochemical Incorporation of Carbon Dioxide into Fluorotoluene Derivatives under Mild Conditions

One of the main challenges to combat climate change is to eliminate or reuse Carbon dioxide (CO2), the largest contributor to the greenhouse gases that cause global warming. It is also important to synthesize compounds through greener technologies in order to obtain more environmentally friendly solutions. This study describes the electrocarboxylation process of α,α,α-trifluorotoluene using different working electrodes (glassy carbon, silver and copper) and electrolytes (polar aprotic solvent and ionic liquid). Carboxylated compounds were obtained in the same way in both electrolytic medias with more than 80% conversion rates, high yields, good selectivity, and moderate efficiencies using silver and copper as cathodes in organic electrolytes and ionic liquids.

Carbon Dioxide Incorporation Catalyzed by Nickel

Carbon Dioxide Incorporation Catalyzed by Nickel

A Study of Low-Potential Heat Utilization Methods for Oxy-Fuel Combustion Power Cycles

The world community is worried about the effects of global warming. A few agreements on the reduction of CO2 emissions have been signed recently. A large part of these emissions is produced by the power production industry. Soon, the requirements for thermal power plant ecology and efficiency performance may become significantly higher. Thus, the contemporary problem is the development of highly efficient power production facilities with low toxic and greenhouse gas emission. An efficient way to reduce CO2 emissions into the atmosphere, which implies maintaining economic growth, is the creation of closed thermodynamic cycles with oxy-fuel combustion. The Allam cycle is one of the most promising among oxy-fuel power plants. A 50 MW pilot Allam cycle plant was built in Texas. The design for a commercial system with an electrical output of 300 MW is under development. This work is devoted to the improvement of the efficiency and environmental safety of oxy-fuel combustion power cycles via the utilization of compressed working fluid heat. The results of computer simulation obtained using AspenONE software demonstrated that an additional circuit in the multi-flow regenerator might increase net efficiency by 3.5%. Besides this, the incorporation of a supercritical carbon dioxide (S–CO2) Brayton cycle with recompression increased the efficiency by 0.2%. Therefore, the maximum net efficiency of the prospective power unit was 51.4%.

Origin of Indus ophiolite-hosted ophicarbonate veins: Isotopic evidence of mixing between seawater and continental crust-derived fluid during Neo-Tethys closure

Ophicarbonates are found in ophiolite-associated peridotites and bear signature of fluid-rock interaction either on ocean floor or during ophiolite emplacement. The occurrence of ophicarbonate veins hosted by ultramafic rocks of the Indus Ophiolite, Nidar Valley, Ladakh Himalaya, is interpreted within the context of serpentinization of the allochthonous Cretaceous upper mantle section during uplift of the Himalaya orogen. Mixed dolomite-calcite obtained from two veins show carbon isotope ratios consistent with an origin from bicarbonate-dominated fluid and inconsistent with incorporation of atmospheric carbon dioxide in subaerial contact with high pH waters of serpentinization. Strontium isotope ratio of 0.711452–0.712041 are consistent with serpentinization subsequently to emplacement of the ophiolite and by interaction with Cretaceous seawater mixed with continental crust-derived fluid during Neo-Tethys closure. The predominance of lizardite and chrysotile in ophicarbonate veins as documented by Raman spectra also supports a low temperature serpentinization during ophiolite emplacement. The presence of hydrocarbon peaks in fluid inclusions in serpentinized olivine suggests that some of the dissolved inorganic carbon reacted with hydrogen released through oxidation of iron. The ophicarbonates and serpentines in peridotite of Indus ophiolite bear signature of a paleo-environment for Fischer-Tropsch reactions during the last phase of Neo-Tethys closure.

Substrate-dependent CO2 fixation in heterotrophic bacteria revealed by stable isotope labelling

Virtually all heterotrophs incorporate carbon dioxide by anaplerotic fixation. Little explored, however, is the interdependency of pathways and rates of CO2fixation on the concurrent usage of organic substrate(s). Potentially, this could reveal which substrates out of a pool of dissolved organic carbon are utilised by environmental microorganisms. To explore this possibility, Bacillus subtilis W23 was grown in a minimal medium with normalised amounts of either glucose, lactate or malate as only organic substrates, each together with 1g/L NaH13CO3. Incorporation of H13CO3- was traced by elemental analysis-isotope ratio mass spectrometry of biomass and gas chromatography-mass spectrometry of protein-derived amino acids. Until the late logarithmic phase, 13C incorporation into the tricarboxylic acid cycle increased with time and occurred via [4-13C]oxaloacetate formed by carboxylation of pyruvate. The levels of 13C incorporation were highest for growth on glucose and lowest on malate. Incorporation of 13C into gluconeogenesis products was mainly detected in the lactate and malate experiment, whereas glucose down-regulated this path. A proof-of-principle study with a natural groundwater community confirmed the ability to determine incorporation from H13CO3- by natural communities leading to specific labelling patterns. This underlines the potential of the labelling approach to characterise carbon sources of heterotrophic microorganisms in their natural environments.

Prescreening Hydraulic Lime-Binders for Disordered Calcite in Caesarea Maritima: Characterizing the Chemical Environment Using FTIR

ABSTRACTHydraulic lime binders are considered a technological marvel which revolutionized construction techniques in antiquity. The core material is made of a binder that is a mixture of calcite and hydraulic phases, which are amorphous silicate compounds that nanostructurally polymerize into insoluble phases that harden even underwater, formed during the reaction between lime and reactive silicates such as volcanic ash. This is also what makes hydraulic lime so hard to radiocarbon (14C) date. These insoluble phases contain carbonates that may set centuries following their application, resulting in younger ages, which may contaminate the calcite fraction that is favorable for 14C dating. This calcite fraction forms upon the incorporation of atmospheric carbon dioxide during the setting of the hydrated lime. Therefore, different characterization methods are being constantly developed for identifying and characterizing the components of hydraulic lime-binders. In this work, we present a rapid characterization technique based on Fourier transform infrared spectroscopy (FTIR) that characterizes the atomic disorder and chemical environment of the carbonates and silicates fractions in the binder. The atomic disorder of the calcite crystallites was determined by the ν2 and ν4 vibrational modes, and the silicates were characterized by the main peak asymmetry and full width at half maximum (FWHM). Different hydraulic binders from Caesarea Maritima were examined, including Herodian mortars from the underwater breakwater and on-land plasters and mortars from the portʼs warehouse and vaults. Hydraulic binders, in which the calcite fraction in the binder shows atomic disorder that is comparable to modern plaster binders, was associated with silicates that have asymmetry and FWHM of clays and quartz. These materials are considered to be in good preservation state for 14C dating since their carbonates crystallites are disordered and did not interact with the environment chemically to form stable and ordered crystals. Interestingly, the atomic disorder of binders that underwent chemical alterations and recrystallization processes, are associated with reactive silicates aggregates such as volcanic ash (pozzolana). These results suggest a new way to prescreen materials for radiocarbon dating based on the composition of lime-binders and preservation state of the carbonate fraction and hydraulic products.