Reaction Kinetics of Transesterification with Titanium Alkoxide-Based Phase-Transforming Catalyst

Abstract

A catalytic process was developed that uses a phase-transforming catalyst to perform a transesterification reaction. In this process, titanium isopropoxide catalyst is added to the reaction medium as a liquid, and as a result of condensation polymerization, the spent catalyst can be removed as a heterogeneous solid. The kinetics of this system was studied using monoolein as the model monoglyceride and isopropanol as the alcohol. A yield optimization study was also conducted using soybean oil as the triglyceride. The titanium isopropoxide catalyst was able to transesterify monoolein completely, giving >99% ester yields. The kinetic study revealed that the transesterification of monoolein with titanium isopropoxide is secondorder with respect to isopropyl alcohol. The rate constant was evaluated to be 0.0002 L mol −1 min −1 . In studies with soybean oil, a maximum ester yield of 71% was observed using 16% (w/w) catalyst under the conditions tested. This catalyst concept, once fully developed, can be quite useful in a multitude of processes because the initial homogeneous catalyst phase alleviates masstransport issues whereas the latter heterogeneity eases separation of the catalyst from the medium.

Reprocessable Acid-Degradable Polycarbonate Vitrimers

“…The diffusion of the reactive groups is more restricted in more densely cross-linked networks, which increases E a . While no obvious trend in E a was observed upon changing catalyst concentration (Figure d, inset), we hypothesize that the observed differences in activation energy are related to a variety of factors including differing cross-linking densities of the samples, the impact of alkoxide or proton concentration on the polarity of the networks, and potential changes in active form or oligomerization of the titanium catalyst at higher concentrations. − …”

Preparation, characterization, kinetic and thermodynamic studies of MgO-La2O3 nanocatalysts for biodiesel production from sunflower oil

“…One or more of these rates may be the limiting rate [35][36][37][38]. Generally, the mechanism transesterification consists of three consecutive and reversible reactions, that triglycerides (TG) reacts reversibly with methanol to produce diglycerides (DG), which further reacts reversibly with methanol to generate monoglycerides (MG), and finally, monoglycerides reacts reversibly with methanol to give to monoalkyl esters (biodiesel) and glycerol [39][40][41]. Equations 1-3 summarize the reaction of transesterification.…”

“…According to previous reported pseudo-first and pseudo-second order reactions for the transesterification reaction of sunflower oil have been proposed [40][41]. In the remainder of this paper we evaluated the comparison between models prediction pseudo first order and pseudo Second order.…”

Novel biomaterials for controlled immunomodulatory drug delivery

“…Transesterification-based polymerization was performed by melt polycondensation following Scheme 5.2 using dm-MalGlu with PEG or a mixture of PEG and PPG at the various conditions stated in shown that this is the optimized titanium alkoxide-based catalyst content for transesterification [226]. Unexpectedly, the resulting pMalGluPEGE (P3) and pMalGluPEGPPGE (P4) were both found to form resin-like solids that were unable to be dissolved in a number of commonly used solvents (i.e., water, acetonitrile, acetone, methanol, and dichloromethane -data not shown).…”