Akademik Veri Yönetim Sistemi
REVIEWS IN CHEMICAL ENGINEERING, cilt.16, sa.3, ss.249-299, 2000 (SCI-Expanded)
Decomposition kinetics of alkyl hydroperoxides is strongly dependent on the decomposition mechanism that is affected by the reaction conditions. Decomposition mechanisms of hydroperoxides are grouped into induced hydroperoxide (radical, solvent, hydroperoxide, photon-induced or thermal), metal-catalyzed, and ionic (non-radical forming, acid or base-catalyzed) decomposition reactions; and each mechanism results in different products and yields. In the first part of the present article, we review the effects of reaction conditions such as solvent and catalyst types, hydroperoxide concentration, and temperature on the mechanism and kinetics of several hydroperoxide decomposition reactions. In the second part, we present kinetic parameters for the acid-catalyzed decomposition of 2-isopropyl-naphthalene hydroperoxide (2-IPNHP), which were determined by treating the experimental data obtained in our laboratories. Process conditions for the decomposition of 2-IPNHP, which is of industrial importance as an intermediate of the novel 2-naphthol and acetone process, diverted the mechanism from ionic to radical reactions, and changed the reaction rates and kinetics. The variations in the overall rate constants and reaction orders for the 2-IPNHP decomposition and 2-naphthol production reactions with solvent type (dodecane, isopropylnaphthalene, acetone, propyl acetate (aprotic solvents of low dielectric constant), acetonitrile, nitrobenzene (aprotic solvents of high dielectric constant), acetic acid (protogenic solvent) and methyl alcohol (amphiprotic solvent)), with catalyst type (HClO4 and H2SO4) and concentration, with initial 2-IPNHP concentration, with nucleophile reagent (H2O2) concentration, and with temperature were given. The changes in the overall kinetic parameters were explained by the change in the decomposition mechanism depending on the polarities, capacities for hydrogen bonding, and acidic and basic properties of the solvents, and by the interactions among the solvent, catalyst and hydroperoxide. The 2-IPNHP decomposition and 2-naphthol production reactions rate equations obtained in the presence of AcOH and 0.321 mot dm(-3) H2O2 are -r(2-IPNHP) = 7.330x10(9)e(-11872/RT) C-2-IPNHP(1.4), mol dm(-3) h(-1) (E-A, cal/mol), (in the range of 0.029-0.143 mol dm(-3) HClO4, 0.959-1.036 mol dm(-3) 2-IPNHP and 22-40 degrees C temperature) and r (2-naphthol) = 0.022x10(9)e(-9525/RT) C2-IPNHP (0.4), mol dm(-3) h(-1) (E-A, cal/mol), tin the range of 0.029-0.143 mol dm(-3) HClO4 and 22-40 degrees C for 0.993 mot dm(-3) 2-IPNHP), respectively.