Multi-Step Alkoxylation Process
Sales growth in the quaternary ammonium salt product line pushed production equipment to its limit, requiring the transfer of technology to a larger reactor system. The change to a larger reactor afforded the opportunity to re-examine the process chemistry, and to optimize the alkoxylation process for the new reactor system. A network of competing reactions were characterized with regard to reaction mechanism and by-product formation. Subsequently, the alkoxylation process was optimized for best selectivity, yield, and reaction time. Reaction rates, heat of reaction, and reaction kinetics were determined, followed by investigations with regard to product stability and decomposition. Based on the process and product characteristics, Air Products and Chemicals developed a model to design a new plant for safe and economic manufacturing of the product.
Reaction rates, heat of reaction, and reaction kinetics of a multi-step alkoxylation process were characterized. A kinetic model that was developed accurately characterized the rate of heat generation resulting from the alkoxylation reaction, and successfully predicted the amount of by-product formed. The process variables examined in the optimization included reactor temperature, alkene oxide feed rate, and cooling water temperature. These system parameters were determined for the experimental data, and the model was incorporated into a global analysis of reaction and heat transfer for an existing plant reactor. Elucidation of the competing chemical processes was necessary so that optimal use could be made of existing process equipment to maximize production of the desired reaction product. The optimization procedure resulted in identification of process conditions leading to the shortest possible cycle time, while simultaneously maintaining reactor safety.
This white paper includes the following topics:
- Process Chemistry
- Product Decomposition
- Experimental Protocol
- Configuration of a Reaction Calorimeter
- Equilibrium Constant for Acid/Base Reaction
- Heat of Reaction
- Measurement of Kinetic Rate Constants
- Characterization of By-Product and Product Chemistry
- Heat Transfer Model for Plant Reactor