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Abstract

Catalytic olefi n metathesis is one of the most emerging tools in synthetic chemistry that can be used explicitly to produce high value products from unsaturated fats and oil feedstock. This review article focuses on the efforts directed toward the development of heterogeneous olefi n metathesis catalytic systems with emphasis on their activity, stability, and reusability in the context of olefi n metathesis of natural fats/oils derivatives. Heterogenization/immobilization of active homogeneous catalysts aspect is discussed. Furthermore, the following topics are addressed: (i) Homogeneous versus heterogeneous catalysis; (ii) Metal-alkylidene based heterogeneous catalyst systems; and (iii) Alkylidene-free heterogeneous catalyst systems. [1] 1909 Emulsion stability and emulsion layer growth were investigated using batch and continuous separations performed on model water-in-oil oilfi eld emulsions stabilized by asphaltenes and inorganic solids. The continuous emulsion layer growth rate and ultimate stability correlated well to batch coalescence parameters. The addition of the coarse solids accelerated coalescence rates at low concentrations but increased emulsion stability above a threshold concentration. Even if the feed is below this threshold, the solids accumulate in the emulsion layer until the threshold is reached, the emulsion becomes stable, and the performance of the continuous separation no longer correlates to the batch tests. [2] 1968 The Utilization of Closed-Loop Prediction for Dynamic Real-Time OptimizationMohammad Z. Jamaludin, Hao Li and Christopher L. E. Swartz This article presents a dynamic real-time optimization formulation that accounts for the action of an underlying MPC system in the predicted plant response. This results in a multilevel optimization problem due to the embedded MPC optimization subproblems. A simultaneous solution strategy is applied in which the MPC subproblems are replaced by their equivalent fi rst-order optimality conditions, permitting reformulation of the problem as a single-level mathematical program with complementarity constraints. Techniques for approximating the closed-loop response are presented, as well as strategies to reduce excessive set-point variation. The method is illustrated through case studies, with its performance evaluated and discussed. [3] References[1] M. Hasib-ur-Rahman, S. Hamoudi, K. Belkacemi, Can. J. Chem. Eng. 2017, 95, 1850