The kinetics for soybean oil hydrogenation using a commercial Ni/Al 2 O 3 catalyst were investigated in a 2 × 10 -3 m 3 agitated reaction calorimeter operating under a wide range of temperatures (383-443 K), pressures (0.12-0.68 MPa), and catalyst loadings (0.02-0.16 Ni wt %). A simple model (model 1) and a novel comprehensive model (model 2) were developed to describe the hydrogenation process based on Langmuir-Hinshelwood kinetic expressions. The catalyst activity and mass-transfer coefficients were incorporated in both models. Under isothermal conditions, modeling results showed that increasing k L a values and pressure and decreasing temperature and catalyst loading decrease the trans fatty acid (TFA) content in the partially hydrogenated soybean oil. Using model 2, a nonisothermal batch reactor was simulated and the results indicated that good heat-transfer control is required to minimize the amount of TFA produced. Also, k L a appeared to be the rate-limiting step in the overall process, and accordingly proper gas-liquid mixing is crucial in commercial hydrogenation reactors.

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Steady‐state transport to a rotating disk electrode coupled with a second‐order homogeneous reaction of arbitrary stoichiometry is analyzed to obtain limiting current enhancement factors as functions of the second‐order rate constant. Analytic solutions are obtained for infinitely fast reaction, and numerical solutions are obtained for finite rates by orthogonal collocation. Anodic bromohydrination of olefins is a hypocatalytic process in which half of the bromide in the electrolytically produced bromine is released by the homogeneous reaction. Enhanced bromide limiting currents are observed in the presence of allyl alcohol and of propylene and compared with the model to estimate the homogeneous rate constants. Under certain conditions the hypocatalytic process can become heterogeneous.