Addition Of Carbon Dioxide Research Articles

Metathetical Exchange, Synthesis and Carbon Dioxide Addition of Higher Homologues of Group 9 Metal Carbynes

Metathetical Exchange, Synthesis and Carbon Dioxide Addition of Higher Homologues of Group 9 Metal Carbynes

Metathetical Exchange, Synthesis and Carbon Dioxide Addition of Higher Homologues of Group 9 Metal Carbynes.

A one-pot synthesis for previously unknown heavy homologues of group 9 metal carbynes [(Me3P)3CoºGeAr*] (1), [(Me3P)3RhºGeAr*] (2), [(Me3P)3IrºGeAr*] (3), [(Me3P)3IrºSnAr*] (5), and [(Et3P)3IrºPbAr*] (7) is presented [Ar* = C6H3-2,6-(Trip)2, Trip = 2,4,6-C6H2iPr3]. During these preparations the tetrylidynes [(Me3P)3RhºSnAr*] (4), and [(Me3P)3RhºPbAr*] (6), were also prepared in a one-pot procedure. In a hitherto unknown metathetical exchange reaction the transition metal plumbylidynes were converted into the respective stannylidynes in reaction with terphenyl stannylene chloride, and the germylidynes were formed from the corresponding stannylidynes in reaction with terphenyl germylene chloride. This metathesis reaction was tracked by 31P{1H} NMR spectroscopy which shows complete exchange of the tetrel [EAr]-fragment and the formation of an intermediate in the rhodium plumbylidyne reaction with stannylene chloride (Ar = Ar*, Tbb). Reactions of the tetrylidynes (2-5) with carbon dioxide yield the products of a redox reaction [(Me3P)3(CO)M-E(η2-O2CO-κ2O)Ar*] [E = Ge, M= Rh (11); M = Ir (12); E = Sn, M = Rh (14), M = Ir (16)] with a carbon monoxide coordinated at the transition metal and a carbonate coordinated at the group 14 element. For tin the intermediates formed by mono CO2 addition [(Me3P)3M(µ,η2-CO2-κC:κO)SnAr*] [M = Rh (13), M = Ir (15)] have been isolated.

INVESTIGATION OF 4-METHYLCYCLOHEXANONE OXIME INHIBITOR ACTIVITY AGAINST LOCAL CORROSION

The corrosion properties of steel grade Steel 20 in the NACE environment with the addition of hydrogen sulfide and carbon dioxide were studied, the local corrosion rate in relation to the «pure metal» and in the case of corrosion inhibitors based on imidazolines and 4-methylcyclohexanone oxime was estimated. Based on the results of the work, it can be concluded that steel grade Steel 20 does not have high corrosion resistance in the NACE formation water model, the general corrosion rate over the entire exposure time interval is > 0.1 mm/year, local corrosion damage is present, the local corrosion rate is > 2.4 mm/year. The use of inhibitors of both the imidazoline type and based on 4-methylcyclohexanone oxime makes it possible to reduce the general corrosion rate to values not exceeding 0.4 and 0.2 mm/year, respectively (at an exposure time of 720 h), and reduce the local corrosion rate by at least 10 and 20 times, respectively.

The effects of temperature and CO2 enrichment on the red seaweed Asparagopsis taxiformis from Southern California with implications for aquaculture.

The red alga Asparagopsis taxiformis has recently been recognized for its unique ability to significantly reduce methane emissions from ruminant animals when fed in small quantities. The main obstacle in using this seaweed as a methane-mitigating feed supplement is the lack of commercially available biomass. Little is known about how best to grow this red alga on a commercial scale, as there are few published studies that have investigated the factors that influence growth, physiology, and overall performance. This study examined the effects of temperature and CO2 enrichment on the growth, photophysiology, and concentration of bromoform, the secondary metabolite largely responsible for methane reduction in A. taxiformis. A series of single and multifactor closed culture experiments were conducted on A. taxiformis collected, isolated, and cultured from populations in Southern California. We identified the optimal temperature range to be between 22 and 26°C, with significant short-term stress observed below 15°C and above 26°C. Carbon dioxide addition resulted in increased performance, when accounting for growth per CO2 use. In general, we observed the highest bromoform concentrations in algae with the highest growth rates, but these results varied among experiments. These findings indicate that through environmental control and by addressing limiting resources, significant increases in biomass production and quality can be achieved.

Effects of carbon dioxide addition on soot dynamics in ethylene/air inverse diffusion flames: An experimental and computational analysis

Effects of carbon dioxide addition on soot dynamics in ethylene/air inverse diffusion flames: An experimental and computational analysis

Cadmium Iodide as a Catalyst for the Addition of Carbon Dioxide to Oxiranes

The CdI2-catalyzed addition of CO2 to oxiranes is presented. The catalysts are obtained by mixing amines with CdI2. It is found that amines with a large number of aliphatic groups provide the higher conversion; the presence of additional OH and NH groups negatively affects the conversion.

Flame-retardant performance of a novel lignin-based rigid polyurethane foam prepared from pulping black liquor

Flame-retardant performance of a novel lignin-based rigid polyurethane foam prepared from pulping black liquor

EFFECT OF THE FEED GAS MIXTURE COMPOSITION AT METHANOL DEHYDROGENATION TO FORMALDEHYDE ON SUPPORTED OXIDE CATALYSTS

The article presents the results of a study of the activity of deposited oxide catalysts in the process of obtaining formaldehyde from methanol. Model catalysts were prepared by impregnation of finely porous silica gel with nitrate solutions of zinc, copper, silver, sodium, followed by heat treatment. The catalytic properties of the samples were studied in the reaction of methanol dehydrogenation in the flow mode on a fine fraction of the catalyst. With the complication of the composition of the feed gas mixture, part of argon was replaced with hydrogen, mono- and carbon dioxide. The reaction mixture was analyzed by gas chromatography, IR spectroscopy and photocolorimetry. At a temperature of ~350 °C, a noticeable formation of formaldehyde begins, upon reaching a temperature of 500 °C in the reactor, methanol processing begins to decrease, while the concentration of formaldehyde changes insignificantly. Along with formaldehyde, dimethyl ether, methane and carbon dioxide are fixed in the reaction products. At the end of the tests on the surface of the catalyst, carbon, oxygen and hydrogen are quantified using elemental analysis methods, the ratio between which corresponds to the formula (-COH-)n. That is, along with the target reaction, methanol is consumed for the formation of surface hydrocarbons. Oxymethylene oligomers can decompose along two competing routes to form formaldehyde or carbon and CO2. The addition of carbon dioxide to the feed gas mixture after the catalyst enters the stationary mode leads to a significant increase in its formaldehyde yield. It is obvious that the route with the formation of carbon dioxide is associated with the target reaction of formaldehyde production, where the catalytic reaction maintains a certain concentration of active centers. Thus, it can be assumed that carbon dioxide as a product of decomposition of surface oxymethylene compounds affects the rate of the catalytic reaction by maintaining a certain concentration of surface hydrocarbons, which are necessary as an element of the active catalytic center. For citation: Morozov L.N., Vorobyov A.S., Kunin A.V., Egorov N.A., Timoshin E.S. Effect of the feed gas mixture composition at methanol dehydrogenation to formaldehyde on supported oxide catalysts. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 7. P. 88-95. DOI: 10.6060/ivkkt.20246707.7003.

Experimental Study on the Improvement of Char Physicochemical Properties and Reactivity by Activation Process in CFB.

Solid carbon can be transformed into activated char with higher reactivity through the activation process in a circulating fluidized bed (CFB) to improve the Boudouard reaction. A new technology for reducing CO2, the activated-reduction technology, was proposed. In order to investigate the influence of relevant parameters (carbon dioxide addition, oxygen concentration, and O2/C) of the activation process on the physicochemical properties and reactivity of activated char, the experiments were carried out on a bench-scale CFB. The relationship between the parameters and the reactivity of activated char is explored. The result shows that compared with the raw coal, the pore structure of activated char is developed, the number of active sites increases, the degree of graphitization decreases, and higher reactivity is possessed. For the activation process, less of the O2/C and moderate oxygen concentration promote the increase in activated char reactivity, which is conducive to the reduction of CO2. The results of the correlation discussion show that the reactivity is difficult to be characterized by a single simple parameter. The reactive specific surface area (RSSA) obtained by multiplying the mesoporous specific surface area and I D3+D4/I all has a good effect on describing the reactivity.

Normobaria – Physiological Conditions and Possibities of Applications

Abstract The article discusses the impact on the human body of breathing in an atmosphere of normobaric or slightly hyperbaric conditions, as well as breathing a mixture with an increased content of oxygen with the addition of carbon dioxide. The positive and negative effects breathing with an increased content of oxygen of hyperbaric conditions were compared with normobaric conditions and indications for their use were presented.

Model for estimating the effects of pressure and dilution on the flammability limits of fuels in constant-volume systems at subatmospheric pressure

Model for estimating the effects of pressure and dilution on the flammability limits of fuels in constant-volume systems at subatmospheric pressure

Co-pyrolysis coking characteristics of nC12H26 and DHN/MeOH/EtOH/MF/DMF/H2O/H2/CO2/CO/N2 under supercritical condition

Co-pyrolysis coking characteristics of nC12H26 and DHN/MeOH/EtOH/MF/DMF/H2O/H2/CO2/CO/N2 under supercritical condition

Explosion characteristics of hydrogen-nitrous oxide mixtures with carbon dioxide addition

Explosion characteristics of hydrogen-nitrous oxide mixtures with carbon dioxide addition

Dissolution and recovery of poly(3-hydroxybutyrate) in switchable solvents and the formation of a switchable gel

Dissolution and recovery of poly(3-hydroxybutyrate) in switchable solvents and the formation of a switchable gel

Desalinated water quality: Remineralization technique at the Al-Hoceima desalination plant (northern Morocco)

One solution to the shortage of drinking water in Morocco is the development of reverse osmosis (RO) desalination plants. However, the quality of the permeate produced is corrosive, unbalanced, and does not meet the standards required for its use. The post-treatment process at the Al-Hoceima desalination plant in northern Morocco consists of the addition of carbon dioxide (CO2) and hydrated lime (Ca (OH)2). In this study, various analyses were utilized to assess the physical-chemical quality parameters of the water produced after remineralization. The results revealed that the remineralization method adopted by the plant is relatively complex and associated with difficulties in maintaining optimal remineralized water parameters such as pH, TAC, TH, and Ca2+. However, the water produced re-establishes its calcocarbonic balance and is of satisfactory quality for human consumption.

In Situ Investigation of Electrochemically Mediated Carbon Capture and Release Via Quinone Chemistry in Aqueous Media

The development of devices capable of capturing and sequestering carbon dioxide emissions directly from air or at point sources is motivated by mitigating climate change. Electrochemically driven carbon capture and release at ambient temperature and pressure through the formation of complexes with organic redox active molecules [1,2] or via pH swing caused by proton-coupled electron transfer during molecular redox events [3,4] has shown promising results for carbon capture and release in terms of energy cost, scalability and safety compared to the state of the art amine scrubbing technologies [5].Quinones are organic molecules containing an unsaturated six-member ring with two carbonyl groups. They exhibit two potential mechanisms of CO2 capture. (a) Upon electrochemical reduction, the carbonyl groups within quinones provide sites for nucleophilic addition of carbon dioxide which results in the formation of a quinone-CO2 adduct (CO2reversibly bound by quinones). (b) Depending on the pKa of the quinone and the local pH, the electrochemical reduction of the compound can be proton-coupled, creating hydroxide, which captures CO2 as carbonate or bicarbonate.In this work, we introduce in situ electrochemical characterization and in situ fluorescence microscopy to separately quantify the two aforementioned contributions toward capture of CO2 at partial pressures ranging from 0.1 bar to 0.4 mbar. The non-invasive in situ analytical methods introduced in this work are used to distinguish, with sub-second time resolution, between the oxidized, reduced and adduct species by their electrochemical and fluorescence signatures. The results of this study permits us to understand the underlying simultaneous contributions of quinone-CO2 adduct path and the pH-swing path toward carbon capture and release and, additionally, introduces powerful non-invasive methods for gathering insights on similar systems. 1X. Li, X. Zhao, Y. Liu, T.A. Hatton, and Y. Liu, "Redox-tunable lewis bases for electrochemical carbon dioxide capture", Nature Energy 7, 1065 (2022). 2Y. Liu, H.Z. Ye, K.M. Diederichsen, T. Van Voorhis, and T.A. Hatton, "Electrochemically mediated carbon dioxide separation with quinone chemistry in salt-concentrated aqueous media", Nat Commun 11, 2278 (2020). 3S. Jin, M. Wu, Y. Jing, R.G. Gordon, and M.J. Aziz, "Low energy carbon capture via electrochemically induced pH swing with electrochemical rebalancing", Nat Commun 13, 2140 (2022). 4S. Jin, M. Wu, R.G. Gordon, M.J. Aziz, and D.G. Kwabi, "pH swing cycle for CO2 capture electrochemically driven through proton-coupled electron transfer", Energy & Environmental Science 13, 3706 (2020). 5G.T. Rochelle, "Amine scrubbing for CO2 capture", Science 325, 1652.

Molecular Dynamics Study on the Diffusion Mass Transfer Behaviour of CO2 and Crude Oil in Fluids Produced via CO2 Flooding.

Carbon dioxide flooding is one of the main methods used to improve crude oil recovery. It can not only improve oil recovery but also reduce greenhouse gas emissions. However, the addition of carbon dioxide makes crude oil become a more complex multiphase fluid; that is, carbon dioxide flooding-produced fluid, in which CO2 and various components in crude oil mass transfer each other. This results in significant changes in the structure and properties of crude oil that increase the hazards associated with its gathering and transportation. Therefore, it is very important to explore the microscopic mechanism for the diffusion mass transfer of CO2 and crude oil in this fluid, especially during its gathering and transportation. In this study, the diffusion mass transfer process of CO2 and crude oil in fluids produced via CO2 flooding is studied using molecular dynamics, and the influences of temperature, gas-oil ratio and water content are explored. Observations of the configuration and dynamic behaviour of the system show that after the system reaches equilibrium, the majority of the CO2 molecules are distributed at the oil-water interface, and CO2 is more prone to diffusing into the oil phase than the water phase. Increases in temperature and water content inhibit, while increases in the gas-oil ratio promote, the diffusion mass transfer of CO2 in the crude oil system. The results of this study reveal the mechanism for the diffusion mass transfer of CO2 and crude oil in fluids produced via CO2 flooding and account for the influence of the water phase, which is consistent with actual production conditions and has certain guiding significance for the safe operation of oil and gas gathering and transportation.

Investigation on synergistic suppression of hydrogen explosion behaviors by ethylene and carbon dioxide

Investigation on synergistic suppression of hydrogen explosion behaviors by ethylene and carbon dioxide

Room temperature electro-carboxylation of styrene and stilbene derivatives: A comparative study

The use of carbon dioxide as a comparatively cheap, abundant and non-toxic C-1 synthon is a topic of considerable interest and importance. The electrochemical addition of carbon dioxide across carbon–carbon double bonds is one of the more promising of such procedures, offering the possibility to convert a range of alkene substrates to valuable carboxylated products. However, much remains unknown about both the mechanism of reaction and how to influence product specificity during electro-carboxylation of alkenes. Herein, we explore the electrochemical addition of carbon dioxide (1 atm) to a range of olefinic substrates using nickel working electrodes and magnesium anodes at room temperature, producing the mono-substituted carboxylate derivatives preferentially (with no formation of the Markovnikov isomers of these mono-substituted carboxylate derivatives when the starting materials are non-symmetrical). These findings are rationalized using both experimental and computational methods, suggesting that the choice of Ni as a working electrode is critical in determining the reaction outcomes that are observed. Moreover, we also present direct evidence that a pathway whereby the alkene substrates are first reduced at the electrode surface and then react with dissolved CO2 is operating. Together, these results offer the potential for selective access to a range of valuable mono-carboxylic acids via the reduction of the corresponding alkene precursors in the presence of carbon dioxide.

Assessment of total coliforms and E. coli removal in algae-based pond under tropical temperature in addition of carbon dioxide (CO2) and shading

Assessment of total coliforms and E. coli removal in algae-based pond under tropical temperature in addition of carbon dioxide (CO2) and shading