N-propyl Formate Research Articles

Efficient separation of alcohol ester via extractive distillation and pressure swing distillation based on molecular interaction mechanism analysis

N-amyl alcohol, n-amyl formate, n-propanol and n-propyl formate are all organic solvents with important industrial application value. In industrial production, related alcohol ester azeotropic systems are often generated. Therefore, it is necessary to study the refining process of these substances. The work designed purification processes for two different azeotropic systems of alcohol esters via extractive distillation and pressure swing distillation methods. The required binary interaction parameters were obtained through vapor–liquid equilibrium experiments. Based on experimental data, a suitable entrainer was determined through different methods of analysis. The processes were optimized with the economic cost as the objective. In addition, it evaluated and analyzed different processes from multiple perspectives. This work explores the purification process of alcohol ester systems, providing theoretical guidance for achieving efficient separation of alcohol ester systems.

Exploring conformational change profile of n-propyl ester of formic acid by combining ultrasonic relaxation spectroscopy and molecular orbital calculations

We report a detailed investigation of the ultrasonic absorption spectra of n-propyl formate in the liquid state over a wide frequency and temperature range under constant pressure. The ultrasonic absorption measurements were performed by standard acoustic resonator and pulse techniques. A single relaxational phenomenon has been observed and is attributed to a unimolecular reaction due to a conformational change of the n-propyl formate molecule in the liquid state. The characteristic relaxation frequency increases with increasing temperature and vise versa. In an effort to confirm the assignment of the relaxation process and to determine the corresponding thermodynamic properties, relaxation parameters were further investigated as a function of temperature. Activation enthalpy and enthalpy difference between the two isomeric forms have been estimated equal to ΔH∗ = 4.21 ± 0.16 kcal/mol and ΔH0 = 6.21 ± 0.29 kcal/mol, respectively. The corresponding energy barrier was estimated equal to ΔEexperimental = 10.42 ± 0.33 kcal/mol. Molecular orbital calculations have been applied to obtain the standard enthalpy of formation for n-propyl formate at various dihedral angles around C–O bond. The results exhibited two clear minimum standard enthalpies of formation and the energy barrier has been calculated equal to ΔΕ = 11.62 kcal/mol, close to the experimental value considering that the calculation was performed in a vacuum environment. The results confirm the absence of shear viscosity relaxation in this frequency range. The ratio of the volume viscosity to the static shear viscosity ηV/ηS has been determined revealing a clear temperature dependent and ηV>ηS supporting the assignment of the observed relaxation process to the rotational equilibrium. The results are analyzed in view of the current phenomenological status of the field.

Working Toward Faster Charging Lithium-Ion Cells through Electrolyte Chemistry

As the adoption of electric vehicles continues to increase, there is a growing demand for faster charging lithium-ion cells to compete with the convenience of fuel-powered vehicles. Yet even for modern designs, rapidly charging lithium-ion cells can cause a decrease in cycle and calendar lifetimes. This is largely attributable to the large overpotentials required to apply large currents, which can lead to unwanted lithium metal plating at the graphite electrode surface. Moreover, as electrode thickness increases for higher energy density cells, lithium-ion transport in the electrolyte becomes limited, leading to even larger overpotentials. This work will present novel electrolytes with improved lithium-ion transport properties. Several co-solvent systems were identified based on the viscosity, permittivity (dielectric constant), and DFT-calculated electrochemical stability windows of the pure compounds. Several formate, nitrile, ketone, and amide co-solvents will be shown to increase the ionic conductivity of LiPF6 in conventional organic-carbonate-based solutions (Figure 1). Based on gas production during the first formation cycle in Li[Ni1-x-yCoxAly])2/graphite-SiO pouch cells, five candidates were identified: methyl formate (MF), ethyl formate (EF), propionitrile (PN), isobutyronitrile (iBN), and dimethyl formamide (DMF). High temperature storage (60°C), ultrahigh-precision coulometry (UHPC), and long-term cycling results will be presented showing that MF offers the greatest balance between conductivity increase and cell lifetime. PN may prove useful for low temperature (< 40°C) applications. Figure 1 – a) Ionic conductivity of 1.2 mol L−1 LiPF6 solutions prepared with 20% of co-solvent and 80% of a 25:5:70 mixture by weight of ethylene carbonate, ethyl methyl carbonate, and dimethyl carbonate, respectively. b) Solution conductivities relative to control solution, i.e., no co-solvent. Co-solvents include isobutyl acetate (iBA), methyl propionate (MP), methyl butyrate (MB), methyl formate (MF), ethyl formate (EF), n-propyl formate (nPF), isobutyl formate (iBF), propionitrile (PN), isobutyl nitrile (iBN), methyl ethyl ketone (MEK), and dimethyl formamide (DMF). Figure 1

Photolysis of n-Propyl Formate in the Presence of O2 and NO2: Peroxy Formyl Propyl Nitrate CH3CH2CH2OC(O)OONO2 Synthesis and Characterization.

The photo-oxidation of n-propyl formate (initiated by chlorine atoms) was studied in the presence of NO2, and the products were identified. The Cl atom attack to the molecule occurs in four sites, leading to the formation of formic acid, carbon dioxide, dicarbonylic products, nitrates, peroxy propionyl nitrate (CH3CH2C(O)OONO2, PPN), and a new peroxynitrate, peroxy formyl propyl nitrate (CH3CH2CH2OC(O)OONO2, PFPN). To characterize bulk quantities of the PFPN, its synthesis was carried out by the photolysis of mixtures of CH3CH2CH2OC(O)H, NO2, Cl2, and O2. After purification, its infrared spectrum and thermal stability were determined. The main infrared absorption bands and their corresponding cross sections are 796, 1219, 1302, 1741, and 1831 cm(-1) (1.16, 3.11, 0.88, 2.42, and 1.34 × 10(-18) cm(2) molec(-1), respectively). Thermal decomposition was studied as a function of pressure from 6.0 to 1000 mbar at 298 K, and the activation energy was determined between 293 and 304 K at total pressures of 9.0 and 1000 mbar (Ea = 98 ± 3 and 110 ± 2 kJ/mol, respectively). The atmospheric thermal lifetimes were obtained from kinetic parameters.

Ultrasonic Studies in Binary Mixtures of N-Propyl Formate with 1-Alcohols At 303 K

Ultrasonic Studies in Binary Mixtures of N-Propyl Formate with 1-Alcohols At 303 K

Pulsed laser photolysis vacuum UV laser-induced fluorescence kinetic study of the reactions of Cl( 2P 3/2) atoms with ethyl formate, n-propyl formate, and n-butyl formate

Cl( 2P 3/2) atoms were produced by photolysis of Cl 2 at 351 nm in the presence of alkyl formates and monitored by LIF spectroscopy at 134.72 nm. Rate coefficients of k(Cl + C 2H 5OC(O)H) = (9.5 ± 0.3)×10 −12, k(Cl + n-C 3H 7OC(O)H) = (4.5 ± 0.3) × 10 −11 and k(Cl + n-C 4H 9OC(O)H) = (1.2 ± 0.1) × 10 −10 cm 3 molecule −1 s −1 were determined at 295 ± 2 K in 6–7 Torr of Ar diluent. These values are 15–30% lower than reported in a previous pulsed laser photolysis resonance fluorescence study. The discrepancy may reflect complications arising from the fact that the time scales for chlorine atom loss and regeneration were not sufficiently decoupled in the previous study.

Kinetics of the gas phase reactions of chlorine atoms with a series of formates

Relative rate techniques were used to study the reactivity of Cl atoms with a series of formates in 700 Torr of N 2 diluent at 296 K. Rate constants were determined for the following compounds: methyl formate, (1.30 ± 0.13) × 10 −12; ethyl formate, (9.57 ± 1.27) × 10 −12; n-propyl formate, (4.65 ± 0.47) × 10 −11; and n-butyl formate, (1.12 ± 0.14) × 10 −10 cm 3 molecule −1 s −1. These results are consistent with previous relative rate studies but are approximately 20–30% lower than the results from an absolute rate study of the reactivity of chlorine atoms towards esters. Likely explanations for the discrepancy are discussed.

Temperature Dependence for the Rate Coefficients of the Reactions of the OH Radical with a Series of Formates

The kinetics of the reactions of OH with methyl formate (1), ethyl formate (2), n-propyl formate (3), n-butyl formate (4), and tert-butyl formate (5) were studied using the pulsed laser photolysis−laser-induced fluorescence technique. The obtained results in the temperature range 233−372 K were the following (in cm3 molecule-1 s-1): k1 = (8.54 ± 1.98) × 10-13 exp[−(461 ± 70)/T], k2 = (5.66 ± 1.10) × 10-13 exp[(134 ± 53)/T], k3 = (1.65 ± 0.45) × 10-12 exp[(42 ± 78)/T], k4 = (3.63 ± 1.08) × 10-12 exp[(15 ± 88)/T], and k5 = (3.59 ± 0.98) × 10-12 exp[−(449 ± 82)/T]. At room temperature the obtained rate coefficients were the following (in 10-13 cm3 molecule-1 s-1): k1 = 1.73 ± 0.21; k2 = 8.52 ± 0.75; k3 = 18.0 ± 1.7; k4 = 35.4 ± 5.2; and k5 = 7.46 ± 0.91. These results are discussed with respect to literature data and structure−activity relationships.

EPR study of radicals derived from n-propyl formate

Using the TiCl 3H 2O 2 radical-generating method, we have successfully characterized by EPR at ca. 25°C the radicals formed from the substrate n-propyl formate: CH 3CH 2ĊHOCHO, CH 3ĊHCH 2OCHO, and ĊH 2CH 2CH 2OCHO. As expected on the basis of previous studies in our laboratory, the first two radicals showed a long-range formyl-proton coupling and the last one did not. Moreover, the size of the γ- and δ-CH formyl-proton couplings in CH 3CH 2ĊHOCHO and CH 3ĊHCH 2OCHO, respectively, agreed with the dependence of such couplings on radical structure previously predicted for species of types ĊOCHO and ĊCOCHO.

Acid catalysis in the gas phase: dissociative proton transfer to formate and acetate esters

The flowing afterglow and selected ion flow tube techniques are employed in gas-phase measurements of the intrinsic kinetics of protonation of methyl formate, n-propyl formate, ethyl acetate, and n-propyl acetate and subsequent fragmentation according to[Formula: see text]with R = H and CH3, R′ = CH3, C2H5, and (CH2)2CH3, and A = H2, CH4, CO, and H2O. Protonation by the acids, AH+, with relative strengths spanning a range of 65 kcal mol−1, is observed to proceed extremely rapidly with rate constants at 299 ± 2 K encompassing values of 2.9 to 8.5 × 10−9 cm3 molecule−1 s−1. Fragmentation is observed for HCOOCH3 only with the strongest acid, H3+, to produce CH3OH2+. For HCOO(CH2)2CH3, fragmentation is observed to produce C3H7+ with H3O+, and also HCOOH2+ with H3+. Little fragmentation of CH3COOC2H5 occurs with H3O+ but with H3+ the major product is CH3COOH2+ with smaller amounts of CH3CO+ and C2H5+. Proton transfer from H3O+ to CH3COO(CH2)2CH3 results in considerable dissociation to form CH3COOH2+. The fragmentation of these esters is discussed in terms of known reaction energetics and in terms of mechanisms for unimolecular acyl–oxygen, AAc1, and alkyl–oxygen, AA11, fission often invoked for analogous reactions in solution as well as modifications of these mechanisms which have been proposed in the context of recent gas-phase measurements.

Thermal ion—molecule reactions in oxygen-containing molecules. Condensation—elimination reactions in n-propyl formate

The condensation—elimination reactions involving CH 2OH + and CH 2CHCH 3 + in n-propyl formate have been studied using a time-of-flight mass spectrometer. CH 2OH + reacts with the neutral molecule to form HCOOC 3H 7H +, HCOOC 3H 7CH + and HCOOC 3H 7CHO +; CH 2CHCH 3 + reacts to form HCOOC 3H 7H + and HCOOC 3H 7CH 2CHCH 2 +. The condensation—elimination reactions leading to the formation of these ions were studied using n-propyl formate- d. The product ions are formed by the dissociation of the intermediate complex in which extensive scrambling does not take place. The rate constants for the product ions resulting from the condensation—elimination and dimerization reactions were obtained. The rate constant of the proton transfer reaction by CH 2OH + is larger than that by CH 2CHCH 3 +, and thus it was found that the proton donor activity of an oxonium ion such as CH 2OH + is greater than that of a carbonium ion such as CH 2CHCH 3 +.

Description of Field Tests To Determine Residual Oil Saturation by Single-Well Tracer Method

Two field tests were conducted using the single-well tracer test to measure residual oil saturation. A description of the tests is presented. A dilution effect or production from zones that did not take tracer injection occurred and had to be accounted for in the data analysis. Introduction Residual oil saturation measurements are important in the evaluation of tertiary recovery projects. Reliable values are necessary to evaluate a pilot performance and to determine the potential for commercial tertiary recovery projects. projects. The single-well tracer method to measure residual oil saturation in watered-out formations has been described by Tomich et al. This method has the attractive feature of measuring the residual oil saturation in a relatively large pore volume and involves the following steps:Injecting a bank of water containing a primary tracer, either ethyl acetate or n-propyl formate.Shutting in a well to allow time for some of the primary tracer to react, forming a secondary tracer of primary tracer to react, forming a secondary tracer of ethyl alcohol or n-propyl alcohol.Producing a well and analyzing water samples to determine concentration profiles of the primary and secondary tracers. The separation of the arrival times of the two tracers indicates the residual oil saturation. This separation is caused by different partitioning of the primary and secondary tracers between the oil and water. primary and secondary tracers between the oil and water. The greater the separation between the tracers, the higher the residual oil saturation. Continental Oil Co. has been licensed to conduct Exxon Production Research Co.'s single-well tracer method to determine residual oil saturation since 1973. Residual oil saturations were run at three locations in five different wells. A service company tested two wells at one location, while Conoco Production Research tested at the other sites. Logistic problems of scheduling the tests on short notice and economic considerations caused Conoco to conduct its own tests. Two wells were tested at the Maier lease in the Illinois Basin and one well was tested at the Big Muddy field in Wyoming. Both locations had low rates that limited test size. The Big Muddy is a fresh water reservoir, while salinity of the Maier lease is about 10,000 ppm. There was no appreciable gas production with either test. This paper coversthe details of the field tests conducted solely by Conoco,the determination of the partition coefficients, andthe fitting of the produced partition coefficients, and (3) the fitting of the produced tracer concentrations using Exxon's single-well tracer computer models. Several approaches were made to fit the data from the Big Muddy test because results were complicated by drift and the tracers were diluted by water from zones that did not accept them. Test Design The following items were considered when designing the test.A large test (up to 90 bbl of injection per foot of pay) was desirable. Injection of 50 bbl per foot of pay was pay) was desirable. Injection of 50 bbl per foot of pay was a good design size.The reservoir temperature dictated the selection of the primary tracer. Ethyl acetate was used for the higher temperatures and n-propyl formate for the cooler reservoirs. JPT P. 194

Kinetics of hydrogen abstraction by difluoroamino radicals from n-propyl formate and the n-propoxycarbonyl radical decomposition

The kinetics of the formyl hydrogen abstraction by difluoroamino radicals from n-propyl formate, using tetrafluorohydrazine as a thermal source of these radicals, has been studied between 398 and 463 K. The rate equation for this abstraction was given by log[k/(ml mol–1 s–1)]=(8.48 ± 0.88)–(77800 ± 7200)/2.3RT where R= 8.314 J mol–1 K–1. The decomposition reaction of the resulting n-propoxycarbonyl radical was also studied. No pressure dependence on this decomposition of the radical was observed in this temperature range and in the pressure range 11–76 Torr. The rate equation was given by log(k/s–1)=(14.11 ± 0.89)–(53000 ± 7300)/2.3RT where R= 8.314 J mol–1 K–1.

Ethyl formate, n-propyl formate, and n-propyl acetate

Ethyl formate, n-propyl formate, and n-propyl acetate