Hydroformylation, liquid olefins

The addition of various surfactants and micelle forming agents on the biphasic hydroformylation of olefins was also considered as a tool for enhancement of the reaction rate. The relation between the extent of emulsification of the reaction mixture and the performance of hydroformylation reaction was also investigated. Mass transfer effects in biphasic hydroformylation of 1-octene in the presence of cetyltri-methylammoniumbromide (CTAB), was studied by Lekhal etal. [33], A mass-transfer model based on the Higbie s penetration theory was proposed to predict the rate of hydroformylation in a heterogeneous gas-liquid-liquid system under... 

Consider the process for manufacture of detergent alcohols (ALC) by hydroformylation of liquid olefins in the Cn-C12 range (OLF) with syngas... 

Fig. 23. Hydroformylation of liquid olefins (Cn-C12) with syngas (H2 and CO), (a) Configuration in existing commercial unit consisting of five bubble column reactors in series, (b) Improved configuration arrived at by systems approach, involving staged injection of hydrogen, (c) The yields of alcohols (desired product) and paraffins (undesired product) are compared for configurations (a) and (b).

Hydroformylation of Olefins in Supported Liquid-phase Catalysis... 

Hydroformylation of olefins in supported ionio liquid-phase oatalysis... 

The separation of the products from the IL catalytic mixture can be performed in various cases by simple decanting and phase separation or by product distillation. In this respect, a continuous-flow process using toluene as extractant has been appHed for the selective Pd-catalyzed dimerization of methyl acrylate in ILs [136]. However, in cases where the products are retained in the IL phase, extraction with supercritical carbon dioxide can be used instead of classical liquid-liquid extractions that necessitate the use of organic solvents, which may result in cross-contamination of products. This process was successfully used in catalyst recycling and product separation for the hydroformylation of olefins employing a continuous-flow process in supercritical carbon dioxide-IL mixtures [137]. Similarly, free and immobilized Candida antarctica lipase B dispersed in ILs were used as catalyst for the continuous kinetic resolution of rac-l-phenylethanol in supercritical carbon dioxide at 120°C and 150°C and 10 Mpa with excellent catalytic activity, enzyme stability and enantioselectivity levels (Fig. 3.5-11). 

Recently, Dupont et al. [76] have reported the hydroformylation of olefins in neat conditions using unmodified or Xantphos-modified Rh(0) nanoparticles, prepared by simple hydrogenation reduction of the chloride salts in imidazolium ionic liquids. They have shown that the particle size has a strong influence on the selectivity of the hydroformylation (Table 11.13). 

Biphasic hydroformylation is a typical and complicated gas-liquid-liquid reaction. Although extensive studies on catalysts, ligands, and catalytic product distributions have appeared, the reaction mechanism has not been understood sufficiently and even contradictory concepts of the site of hydroformylation reaction were developed [11, 13, 20]. Studies on the kinetics of hydroformylation of olefins are not only instructive for improvement of the catalytic complexes and ligands but also provide the basic information for design and scale-up of novel commercial reactors. The kinetics of hydroformylation of different olefins, such as ethylene, propylene, 1-hexene, 1-octene, and 1-dodecene, using homogeneous or supported catalysts has been reported in the literature. However, the results on the kinetics of hydroformylation in aqueous biphasic systems are rather limited and up to now no universally accepted intrinsic biphasic kinetic model has been derived, because of the unelucidated reaction mechanism and complicated effects of multiphase mass transfer (see also Section 2.4.1.1.2). 

As recently reported, the efficiency of SAPC over a much wider hydration range will facilitate its use in industry. Two major commercial applications of SAPC are expected first, many fine chemicals and pharmaceuticals could be produced in better conditions due to high enantioselectivity and secondly, hydroformylation of liquid olefins in continuous fixed-bed reactors under mild conditions with relatively high productivity and selectivity is possible. 

The hydroformylation of olefins is a type of CO insertion reaction that is one of the most important industrial applications of homogeneous catalysis with transition metal complexes (208,209). Conventional industrial processes (e.g., the Oxo process) typically use either cobalt- or rhodium-based catalysts and conduct the reaction in two-phase gas-liquid reactors. Efficient transfer of the reactants from the gas phase into the liquid phase is of primary importance to minimize inherent mass transfer limitations (208). Reactor design thus focuses on optimizing this mass transfer rate by maximizing the interfacial area between phases. An SCE process eliminates this transport restriction since the hydrogen... 

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