Ethylene Glycol: Kinetics of the Formation from Methanol–Formaldehyde Solutions
Michael M. Silaev
The mechanism and kinetics are developed for the initiated nonbranched-chain formation of ethylene glycol in methanol–formaldehyde solutions at formaldehyde concentrations of 0.1–3.1 mol dm–3 and temperatures of 373–473 K. The experimental concentrations of the free unsolvated form of formaldehyde are given at the different temperatures and total concentrations of formaldehyde in methanol. The experimental dependence of the radiation-chemical yields of ethylene glycol on formaldehyde concentration in γ-radiolysis of methanol–formaldehyde solutions at 373–473 K is shown. At a formaldehyde concentration of 1.4 mol dm–3 and T = 473 K, the radiation-chemical yield of ethylene glycol is 139 molecules per 100 eV. The effective activation energy of ethylene glycol formation is 25 ± 3 kJ mol–1. The quasi-steady-state treatment of the reaction network suggested here led to a rate equation accounting for the nonmonotonic dependence of the ethylene glycol formation rate on the concentration of the free (unsolvated) form of dissolved formaldehyde. It is demonstrated that the peak in this dependence is due to the competition between methanol and CH2=O for reacting with the adduct radical HOCH2CH2O•.
A.I. Novoselov, M.M. Silaev, and L.T. Bugaenko, “Effect of Temperature on the Yields of Final Products in the γ-Radiolysis of Formaldehyde Solutions in С1–С3 Alkanols,” Khim. Vys. Energ., 2004, vol. 38, no. 4, p. 270 [High Energy Chem. (Engl. Transl.), vol. 38, no. 4, p. 236].
M.M. Silaev, and L.T. Bugaenko, “Mathematical Simulation of the Kinetics of Radiation Induced Hydroxyalkylation of Aliphatic Saturated Alcohols,” Radiat. Phys. Chem., 1992, vol. 40, no. 1, p. 1.
M.M. Silaev, A.V. Rudnev, and E.P. Kalyazin, “Formaldehyde. III. The Concentration of Free Formaldehyde as a Function of Temperature, Solvent Polarity, and the Total Formaldehyde Concentration in the Solution,” Zh. Fiz. Khim., 1979, vol. 53, no. 7, p. 1647.
M.M. Silaev, “Estimating the Solvent Concentration in Formaldehyde Solutions at Various Temperatures,” Zh. Fiz. Khim., 1993, vol. 67, no. 9, p. 1944.
A.I. Novoselov, M.M. Silaev, and L.T. Bugaenko, “Dependence of Ethanediol Yield on Formaldehyde Concentration in γ-Radiolysis of Methanol–Formaldehyde System at 373–473 K,” Khim. Vys. Energ., 2008, vol. 42, no. 1, pp. 74–75 [High Energy Chem. (Engl. Transl.), vol. 42, no. 1, pp. 69–70].
L.A. Yanovskaya, S.S. Yufit, and V.F. Kucherov, Khimiya atsetalei (Chemistry of Acetals), Moscow: Nauka, 1975.
M.M. Silaev, “Simulation of Nonbranched Chain Proocesses for Producing 1,2-Alkanediols in Alcohol–Formaldehyde Systems,” Teor. Osn. Khim. Tekhnol., 2007, vol. 41, no. 4, p. 379 [Theor. Found. Chem. Eng. (Engl. Transl.), vol. 41, no. 4, p. 357].
M. Oyama, “A FreeeRadical Reaction of Primary and Secondary Alcohols with Formaldehyde,” J. Org. Chem., 1965, vol. 30, no. 7, p. 2429.
M.B. Dzhurinskaya, A.V. Rudnev, and E.P. Kalyazin, “HighhTemperature UV Photolysis of Formaldehyde in Liquid Methanol,” Vestn. Mosk. Univ., Ser. 2: Khim., 1984, vol. 25, no. 2, p. 173.
H. Seki, R. Nagai, and M. Imamura, “γ-Radiolysis of a Binary Mixture of Methanol and Water. The Formation of Formaldehyde in the Radiolysis of Liquid Methanol,” Bull. Chem. Soc. Jpn., 1968, vol. 41, no. 12, p. 2877.
S.W. Benson, Thermochemical Kinetics: Methods for the Estimation of Thermochemical Data and Rate Parameters, New York: Wiley, 1968.
L.V. Gurvich, G.V. Karachevtsev, V.N. Kondrat’ev, Yu.A. Lebedev, V.A. Medvedev, V.K. Potapov, and Yu.S. Khodeev, Energii razryva khimicheskikh svyazei. Potentsialy ionizatsii I srodstvo k elektronu (Bond Dissociation Energies, Ionization Potentials, and Electron Affinity), Kondrat’ev, V.N., Ed., Moscow: Nauka, 1974.
S.Ya. Pshezhetskii, A.G. Kotov, V.K. Milinchuk, V.A. Roginskii, and V.I. Tupikov, EPR svobodnykh radikalov v radiatsionnoi khimii (ESR of Free Radicals in Radiation Chemistry), Moscow: Khimiya, 1972, p. 212.
R.T. Sanderson, “Radical Reorganization and Bond Energies in Organic Molecules,” J. Org. Chem., 1982, vol. 47, no. 20, p. 3835.
M.M. Silaev, “Applied Aspects of the γ-Radiolysis of C1-C4 Alcohols and Binary Mixtures on Their Basis,” Khimiya Vysokikh Energii, 2002, vol. 36, no. 2, pp. 97–101 [High Energy Chem. (Engl. Transl.), vol. 36, no. 2, pp. 70–74].
I.V. Vereshchinskii, and A.K. Pikaev, Vvedenie v radiatsionnuyu khimiyu (Introduction to Radiation Chemistry), Spitsyn, V.I., Ed., Moscow: Akad. Nauk SSSR, 1963, p. 190.
[Michael M. Silaev (2020) Ethylene Glycol: Kinetics of the Formation from Methanol–Formaldehyde Solutions IJIRCST Vol-8 Issue-1 Page No-1-5] (ISSN 2347 - 5552). www.ijircst.org
Michael M. Silaev
Chemistry Faculty, Moscow State University, Moscow, 119991 Russia (e-mail: firstname.lastname@example.org)