Coefficients For CO Research Articles

Diffusion coefficient of CO2 into light hydrocarbons and interfacial tension of carbonated water–hydrocarbon system

Diffusion coefficient of CO₂ into light hydrocarbons and interfacial tension of carbonated water–hydrocarbon system

Peat-accumulation models affected by the transgression-regression: a case study of mineralogy and geochemistry of the Permo-Carboniferous coals in the Lingshi Deposit, Qinshui Basin, China

Mineralogy and geochemistry of Nos.1, 9 and 10 coals in the Lingshi Deposit, Qinshui Basin, China, are investigated in this paper, using industrial analysis, total sulfur and forms of sulfur analyses, optical microscope, scanning electron microscope equipped with energy dispersive X-ray spectrometer, X-ray powder diffraction, X-ray fluorescence, and inductively coupled plasma-mass spectrometers. The results show that the minerals in coals are mainly kaolinite, nacrite, dickite, palygorskite, calcite, pyrite, anatase, dolomite, siderite and barite. Kaolinite of terrigenous origin is commonly discovered in No. 1 coal, which results in a high concentration of SiO2 (up to 6.81%) and Al2O3 (up to 8.42%); In the process of coalification, kaolinite could be converted into dickite and nacrite in Nos. 9 and 10 coal; Pyrite, the host of W, Tl, and As, and palygorskite in Nos. 9 and 10 coals are formed under the influence of the transgression. Besides, Nos. 9 and 10 coals, affected by transgression, are similar in the element contents and distribution patterns with positive δYN anomalies (up to 1.44). However, No. 1 coal, normalized by No. 10 coal, is characterized by high concentration coefficients of Co, Ni, Sb, Li, Be, Sc, V, Cu, Ga, Rb, Cs, Ba, Pb and Th (2 < CC < 10), and these elements are derived from clay minerals of terrigenous origin, which means that Permo-Carboniferous coals in the Lingshi Deposit show the evolution of a regressive process in general.

Bulk tracer diffusion in CoCrFeNi and CoCrFeMnNi high entropy alloys

High entropy alloys (HEAs) have emerged as a promising class of equiatomic or near equiatomic multicomponent alloys, which garner fundamental curiosities and interest in high temperature applications. Understanding diffusion kinetics of HEAs is critical to assess their phase stability and deformation behaviour, particularly at elevated temperatures. For the first time, bulk tracer diffusion coefficients of Co, Cr, Fe and Mn are determined in polycrystalline CoCrFeNi and CoCrFeMnNi HEAs using the radiotracer method in the temperature interval of 1073–1373 K. Material homogeneity and the absence of any phase decomposition in CoCrFeNi and CoCrFeMnNi HEAs were established by electron microscopy and atom probe tomography investigations.Both bulk and grain boundary diffusion contributions to penetration profiles are observed for diffusion of Co, Cr, Fe and Mn tracers in both HEAs. The temperature dependencies of bulk diffusion for all tracers show Arrhenius behaviour. The corresponding activation energies (Q) and the logarithm of pre-exponential factors (D0) show a linear relationship, thus following the “compensation rule”. An increase of the configurational entropy leads to reduced diffusion rates only when a homologous temperature scale is used for comparison. The increase of activation energy barrier and lower frequency factors both contribute to the decreased diffusion rates. A cross-over temperature (Tc = 1020 K) is observed for Co diffusion (on slight extrapolation of Arrhenius plot) in CoCrFeNi and CoCrFeMnNi HEAs, while Cr and Fe exhibit almost parallel Arrhenius lines. Above Tc, the Co diffusivity is higher in CoCrFeMnNi than in CoCrFeNi, which suggests that diffusion in HEAs need not be assumed to retard with an increasing number of elements. The existence of a cross-over temperature correlates with the change in binding energy (or enthalpy) of the constituents from CoCrFeNi to CoCrFeMnNi.

Effects of Operational Parameters on Diffusion Coefficients of CO2 in a Carbonated Water–Oil System

Diffusion of carbon dioxide (CO2) in a carbonated water–oil system is of great importance for proper design of CO2-based enhanced oil recovery (EOR) processes. We study the effects of operational parameters such as saturation pressure, temperature, and phase volumes on diffusion coefficients of CO2 in a carbonated water–oil system. Results show that diffusion coefficients of CO2 in both phases are susceptible to saturation pressure. The greater the saturation pressure, the larger the diffusion coefficients. At a given saturation pressure, diffusion coefficients of CO2 in two phases increase by increasing temperature. Values of the coefficients determined at 40 °C are about twice those determined at 20 °C. The equilibration of the system was found to be much faster at the higher temperature. The results indicate that the predicted diffusion coefficients are insensitive to phase volumes, indicating applicability of the determined diffusion coefficients to simulate the mass transfer in large-scale reservoirs.

A novel ion-imprinted polymer induced by the glycylglycine modified metal-organic framework for the selective removal of Co(II) from aqueous solutions

A novel cobalt(II) ion-imprinted polymer (Co(II)-IIP) was synthesized and characterized by X-ray diffractometer (XRD), Fourier transform infrared spectrum (FT-IR), Energy dispersion X-ray spectroscopy (EDS) and N2 adsorption–desorption experiments. Batch experiments were conducted to evaluate its removal performance towards Co(II). The polymer exhibited an excellent adsorption ability on Co(II) with a saturation adsorption capacity of 175mgg−1, which is almost the highest adsorption capacity of ion-imprinted adsorbents on cobalt(II) ion until now. Moreover, there is an encouraging selectivity to other coexisted heavy metal ions. In particular, the selectivity coefficient of Co(II)-IIP to Nickel (k(Co/Ni)Co(II)-IIP=4.17) is far more than that of the non-ion imprinted polymer (NIP, k(Co/Ni)NIP=0.74), which implies that the synthetic imprinted material is successful, and the cobalt(II) ions play the role of a template function. This work provides the first example of an ion-imprinted polymer induced by MOFs, which will introduce new opportunities to the functionalization of MOFs to remove heavy metal ions and radioactive nuclides.

Experimental determination of the absolute infrared absorption intensities of formyl radical HCO

Formyl radical HCO is an important reactive intermediate in combustion, atmospheric and extraterrestrial chemistry. Like in the case of other transients, the lack of knowledge of the absolute IR intensities limits the quantitative spectroscopic studies on this species. We report the first experimental determination of the absorption intensities for the fundamental vibrational bands of HCO. The measurements have been performed using matrix-isolation FTIR spectroscopy. Determination of the values was based on the repeated photodissociation and thermal recovery of the HCO radical using the known value of the absorption coefficient of CO. The experimentally determined values (93.2±6.0, 67.2±4.5, and 109.2±6.6kmmol−1 for the ν1, ν2, and ν3 modes, respectively) have been compared to the calculated IR intensities obtained by DFT and UCCSD(T) computations.

Electrolytic separation of cobalt and tungsten from cemented carbide scrap and the electrochemical behavior of metal ions

Molten salt electrolysis is used to separate and recycling of elemental tungsten and cobalt from cemented carbides. WC–6wt% Co scrap and NaCl–KCl molten salt was used as a sacrificial anode and electrolyte, respectively. The range of preparation parameters and the electrochemical behavior of tungsten and cobalt ions were investigated through electrochemical techniques, such as cyclic voltammetry (CV) and square wave voltammetry (SWV). Results showed that the dissolution potential of cobalt and WC were 0V and 0.6V (vs. Ag/AgCl), and the reduction potentials of Co (II)+2e− ↔ Co (0) and W(II)+2e− ↔ W (0) were −0.2 and 0.2V (vs. Ag/AgCl), respectively. The reduction processes of Co(II) to Co and W(II) to W were both reversible reactions controlled by ion diffusion. The average diffusion coefficients of Co(II) and W(II) were determined by CP to be 5.62×10−5and 3.94×10−5cm2s−1, respectively. Furthermore, the products at cathodes Nos. 1 and 2 were characterized by scanning electron microscopy, X-ray fluorescence and X-ray diffraction analyses. Results showed that pure cobalt and WC powder with a diameter of <100nm was obtained at cathode No. 1 and cathode No. 2. And the result of XRF shows that the purity of the products both Co and WC were higher than 90%. This study reveals that cobalt and tungsten can be separated from WC–6wt% Co scrap by controlling process parameters during electrolysis.

Line positions, pressure broadening and shift coefficients for the second overtone transitions of carbon monoxide in argon

Absolute positions and spectral line-shape parameters of carbon monoxide 0→3 band, P branch transitions are reported. The speed-dependent effects and the influence of velocity-changing collisions were taken into account in the fitted line-shape models. For the first time the values of pressure shift coefficients of CO in argon for this band were determined. The measurements were made with the Pound–Drever–Hall-locked frequency-stabilized cavity ring-down spectrometer, with the frequency axis linked through an optical frequency comb to the UTC(AOS) frequency reference based on a hydrogen maser. Achieved uncertainties of line positions are between 70kHz and 420kHz.

Novel co-polyimides containing pBAPS (bis [4-(4-aminophenoxy) phenyl] sulfone) for CO 2 separation

Abstract Three novel co-polyimides containing a sulfone group (pBAPS) were synthesized and characterized in pursuit of gas separation membrane materials with high CO 2 /CH 4 separation performance. The co-polyimides, 6FDA/BTDA-pBAPS (3:1), 6FDA-pBAPS/mPDA (3:1) and 6FDA-pBAPS/DABA (3:1), were identified as promising structures in our previous study based on a group contribution method. The molecular weight of the co-polyimides varied between 50 and 100 kDa. The TGA analysis of the co-polyimides showed that 6FDA/BTDA-pBAPS and 6FDA-pBAPS/mPDA were stable up to a degradation temperature of higher than 500 °C. However, two-step (∼300 °C and ∼460 °C) degradation curve was observed for 6FDA-pBAPS/DABA. The glass transition temperatures and densities of the co-polyimides are within 276–287 °C and 1.387–1.419 g/cm 3 range, respectively. Measured permeability coefficients for O 2 , N 2 , CO 2 , and CH 4 gases were in good agreement with the predictions of the group contribution method with an average absolute deviation of 0.59, confirming that group contribution methods could be used for fast screening of co-polyimides. The highest CO 2 /CH 4 and CO 2 /N 2 selectivities were obtained for 6FDA/BTDA-pBAPS as 51.9 and 28.6, respectively, with a CO 2 permeability of 7 Barrer. Molecular simulation techniques also were used to better understand the structure/property relationships. Preferential CO 2 sorption sites in co-polyimides were investigated through the analysis of the radial distribution function (RDF), and the available vacancy inside the simulation cell was detected by accessible free volume analysis. RDF results showed that the main interaction with CO 2 arises from the sulfur groups in the pBAPS diamine which increase the sorption coefficient of CO 2 . Moreover, the carboxyl group in DABA diamine enables the formation of hydrogen bonds which results in closed packing and decrease in the sorption and permeability coefficients. Experimental and simulated sorption coefficients are in good agreement with each other.

Oxidation of Co(II) by ozone and reactions of Co(III) in solutions of sulfuric acid

Reactions of the oxidation of bivalent cobalt ions by ozone, of the spontaneous decomposition of trivalent cobalt, and of interactions between Co(III) and chloride ions in solutions of sulfuric acid are studied. The order and rate constant of the process of decomposition of Co(III) are determined. Information on the kinetics of the interaction between Co(III) and Cl– is obtained. Kinetic patterns of the accumulation of Co(III) during the ozonation of solutions of CoSO4 in sulfuric acid are explained. Molar absorption coefficients of Co(III) and Co2+ ions in the visible range of wavelengths are determined.

Impact of H2O broadening effect on atmospheric CO and N2O detection near 4.57 μm

A tunable quantum cascade laser spectrometer (QCLS) was used to study H2O broadening coefficients for CO and N2O transitions at 4.57μm region, which contains well-characterized and relatively isolated transitions of appropriate line strengths for sensitive gas detection. The influence of H2O broadening effect on CO R(11) and N2O P(38e) transitions at 2186.639cm−1 and 2187.099cm−1, respectively, was detailed investigated. Our measurements indicate that H2O broadening coefficients are 1.8 and 1.9 times higher than the corresponding air-broadening parameters, respectively. Based on the experimental data, our simulation confirmed that the WMS-2f shapes of CO and N2O lines will be significantly affected by variations of the water vapor mixing ratio, while no significant dependence on target concentration, and prove that the difference between air- and H2O-broadenings thus cannot be neglected if one wants to measure gas concentrations in a high humid environment with a sub-percent precision.

A novel magnetic and hydrophilic ion-imprinted polymer as a selective sorbent for the removal of cobalt ions from industrial wastewater

A novel magnetic cobalt ion-imprinted polymer (Co(II)-IIP) was prepared by precipitation polymerization using 1-vinylimidazole as a functional monomer. The relative selectivity coefficients of Co(II)-IIP for Co(II)/Cu(II), Co(II)/Cd(II), Co(II)/Zn(II), and Co(II)/Pb(II) were 19.99, 50.28, 11.02, and 7.56, respectively. The experimental datas fit well with the Langmuir adsorption isotherm. The max Co-adsorption capacity obtained from the Langmuir isotherm is 23.09mg/g for Co(II)-IIP. D-R model suggests that chemisorption is the dominant adsorption mechanism. The kinetics studies indicated that the adsorption process closely correlated with a pseudo-second-order model. Co(II)-IIP can be reused more than four times, which demonstrate it have strong performance stability. TLC plates experimental verified that the imprinted material have good hydrophilic property. In addition, Co(II)-IIP can remove Co(II) ion with higher 96% from wasterwater, which confirms it is good adsorbents for the removal of Co(II).

Aqueous Co(II) adsorption using 8-hydroxyquinoline anchored γ-Fe2O3@chitosan with Co(II) as imprinted ions

A novel, bio-based 8-hydroxyquinoline (8-HQ) anchored magnetic chitosan using Co(II) as imprinted ions was prepared and applied for selective removal of Co(II) from aqueous solutions. At first, γ-Fe2O3 has been synthesized by solvent free precipitation route and then combined with 8-hydroxyquinoline anchored chitosan using epichlorohydrin (EPH) as crosslinking agent. The FT- IR spectra showed that 8-HQ has been successfully anchored onto chitosan structure. Moreover, TEM analysis confirmed that the nanocomposite has core–shell structure. The experimental results showed that equilibrium time was 10min moreover, the maximum adsorption capacity of Co(II) with non-imprinted and surface imprinted polymer at pH 8 were 66.6 and 100mgg−1, respectively. The selectivity coefficient of Co(II) ions relative to Cd(II), Ni(II) and Pb(II) were 11, 42 and 2, respectively. Prepared biosorbent represented good stability and good repeatability after three cycle of sorption and desorption using 0.5molL-1 of HNO3 as eluent. Kinetic and thermodynamic behavior were also investigated and result showed that cobalt adsorption followed second order model and endothermic path.

Carbon Dioxide Adsorption Studies on Fly Ash Zeolites

In this study, the potential of fly ash zeolites (FAZ) Linde (LTA) and faujasite (FAU) to adsorb carbon dioxide (CO~2~) was investigated in view of the results of implementation in postcombustion carbon-capture technologies. Adsorption isotherms of selected samples were measured at 273.15 K by a Micromeritics Tristar II 3020 surface analyzer. The highest adsorption capacity was obtained for FAZ with a FAU structure synthesized by a two-stage fusion hydrothermal process from fly ash (FA) that was composed of 65 wt% amorphous components. The adsorption capacity for this sample reached a value of 136.40 mg CO~2~/g FAZ at atmospheric pressure, a result comparable to that for commercial FAU. The selectivity coefficients of CO~2~ adsorption versus N~2~ for FAZ were evaluated from the experimental adsorption isotherms of corresponding gases at 100 kPa. The obtained results are in the range of 23-36, indicating strong affinity of FAZ for CO~2~ molecules. The experimental isotherms of CO~2~ adsorption fit well with Langmuir and Dubinin-Ashtakov mathematical models. The obtained parameters will be used as input data for calculation and design of a pilot plant carbon-capture installation.

How the CO molar extinction coefficient influences the quantification of active sites from CO adsorption followed by IR spectroscopy? A case study on MoS2/Al2O3 catalysts prepared with citric acid

Low-temperature CO adsorption followed by infrared spectroscopy is a powerful technique to quantify the active sites of sulfide and metallic catalysts. However, the site quantification is very delicate, and strongly depends on the molar extinction coefficients of CO on the adsorbing sites. This is exemplified therein on a series of MoS2/Al2O3 catalysts prepared with different amount of citric acid as chelating agent, on which multiple CO adsorption sites exist. It is demonstrated that the use of a global CO molar extinction coefficient leads to incorrect site quantification of MoS2 edge sites, which can induce misinterpretation of the role of citric acid on the MoS2 phase dispersion. Instead, using two CO molar extinction coefficients (20±3μmol−1cm for CO adsorbed on M-edge and 35±9μmol−1cm for CO adsorbed on S-edge), a clear trend of the variation of MoS2 edge site concentration with citric acid addition is obtained and the beneficial effect of citric acid on the dispersion of MoS2 phase is revealed.

Magnetostriction of Co–Fe-Based Amorphous Soft Magnetic Microwires

We studied the correlation between magnetic softness and magnetostriction coefficient for as-prepared and annealed Co–Fe-rich microwires. We found that the hysteresis loops and magnetostriction coefficients of Co and Fe-rich microwires depend not only on the chemical composition of the metal but also on internal stress. Consequently, both hysteresis loop and magnetostriction coefficient can be adjusted by annealing. We varied the time and temperature of annealing and observed changes of the character of the hysteresis loops. These changes correlated with evolution of the magnetostriction coefficient. Drastic changes of the hysteresis loop for Co-rich microwires were attributed to changes of the sign and value of the magnetostriction coefficient.

Molecular‐based virial coefficients of CO2‐H2O mixtures

We report second and third virial coefficients for the system CO2‐H2O, calculated via cluster integrals using quantitative molecular models taken from the literature. Considered models include (1) fits to highly accurate ab initio calculations of the potential energy surfaces, and (2) semiempirical Gaussian Charge Polarizable Models (GCPM). Three‐body effects are found to be essential for obtaining quantitative results. Good agreement with experiment is obtained for the pure‐component coefficients, and for the cross second virial coefficient. For the two cross third virial coefficients, the few experimental data available do not agree well with the calculations; it is not clear whether this is due to problems with the data or deficiencies in the three‐body potentials. The uncertain state of the experimental data, and the relative mutual consistency of values computed from ab initio and GCPM models, suggest that calculated mixture third virial coefficients could be more accurate than values from experiment. © 2015 American Institute of Chemical Engineers AIChE J, 61: 3029–3037, 2015

Net emission coefficient for CO–H2 thermal plasmas with the consideration of molecular systems

This paper deals with the calculation of net emission coefficients (NECs) for CO–H2 thermal plasmas. This task required the elaboration of a complete spectroscopic database including atoms and molecules formed by carbon, oxygen and hydrogen elements. We have used a systematic line by line method to calculate all the main radiative contributions which are the atomic and molecular continua, the atomic lines and the molecular (diatomic and polyatomic) lines. The main diatomic electronic systems for CO–H2 plasmas and the triatomic molecular bands were considered. We present some variations of the net emission coefficient versus temperature, for various pressures and for two relative proportions of the components. The role of the diatomic molecules is important at temperatures lower than 5000K whereas the net emission coefficient presents an unusual peak at temperature around 1000K, due to the presence of the CO2 molecule presenting a strong infrared radiation. Finally, the results show that the NEC slightly depends on the relative proportion of CO and H2.

Extractive separation studies of manganese from spent lithium battery leachate using mixture of PC88A and Versatic 10 acid in kerosene

We investigated the separation of Mn with reduced extraction behavior of Co by PC88A/Versatic 10 acid from a leaching solution of spent lithium-ion batteries containing 11.4g/L Co, 11.7g/L Mn, 12.2g/L Ni, and 5.3g/L Li. The distribution coefficient and separation factor of Mn and Co were determined at different pHs. The slope analysis method was used to determine the extraction mechanism in the PC88A/Versatic 10 acid system. A McCabe–Thiele diagram and countercurrent simulation batch extraction were also investigated to determine at what stage Mn is extracted. The results show a decrease in distribution coefficient of Co and Mn, however, the separation factor of Mn over Co increased. This is an example of the antagonistic effect of Versatic 10 acid addition to PC88A. Using this effect, Mn can be recovered with an organic/aqueous ratio of 1 in the fourth stage in a PC88A/Versatic 10 acid system.

Influence of Subsurface Oxygen in the Catalytic CO Oxidation on Pd(111)

The formation of palladium subsurface oxygen, i.e., Pd(111) saturated with oxygen below the surface, has been demonstrated. This compound is much more stable than palladium surface oxide or bulk palladium oxide, which easily reacts with CO at elevated temperatures. The catalytic activity of an atomically clean Pd(111) surface and of Pd(111) affected by subsurface oxygen (coverage Θ = 0.00–0.46 ML) was studied during the CO oxidation reaction. The measurements were performed for a temperature range of 353–523 K, partial pressures of reactants in the range of 10–7–10–5 mbar, and different subsurface oxygen content. A distinct, previously not observed feature in the dependency of the reaction rate vs temperature was found. Furthermore, it was found that subsurface oxygen reduces the catalytic activity of the Pd(111) surface significantly, which is attributed to reduction of the sticking coefficient of CO and oxygen. In the temperature range applied for investigation of catalytic CO oxidation, the rate of the formation of subsurface oxygen is negligible. However, the formation of this phase starts to be pronounced above ∼600 K. The presence of subsurface oxygen was confirmed by the KLL Auger transition excited by monochromatic X-ray radiation, not by electron beam. It was observed that the classical Auger measurement with an electron beam destroys the subsurface oxygen compound. The combination of the CO titration with Auger peak intensity measurements allows the quantitative analysis of the subsurface oxygen. The problem of subsurface oxygen detection and its impact on the adsorption of CO and oxygen on Pd(111) are discussed. It was suggested that subsurface oxygen and surface oxide can be manufactured simultaneously. Then the obtained activity in the CO oxidation reaction will be a result of two competitive effects, i.e., promoting from surface oxide and inhibiting from subsurface oxide. This might be a source of the discrepancy in results on the influence of surface oxide on the CO oxidation reaction measured by different researchers.