Batch-to-Continuous Conversion of Substituted Alkyl Phenols

Gasoline additives are a critical element of the global transportation fuels industry, specifically in North America where light passenger vehicle fuel requires mandatory additization. The global market for gasoline additives is circa 190,000MT/yr and is predominantly composed of three different chemistries: substituted alkylphenols, polyisobutylene (PIB) amines, and polyether amines. The premise of this project is to support market growth by minimizing capital and operating expenses of new capacity through modular chemical process intensification and batch-to-continuous conversion for production of substituted PIB phenol additives, known as Mannich detergents.

The current manufacturing process for the production of Mannich detergents involves the reaction of a PIB phenol with formaldehyde and a low molecular weight amine. The current batch process is executed in a 30MT reactor and entails 7-8 complex steps resulting in a 40-hour cycle time. The main driving forces for the long cycle time are mainly due to heat and mass transfer limitations associated with the high viscosity of the PIB at reaction temperature, the presence of a volatile amine above its vapor pressure, the presence of water as a by-product and diluent, and the need for exothermic reaction control. Currently, to resolve the viscosity limitations, a solvent is added which creates additional complexity during the post-reaction distillation of water and other volatiles.

In this work, the authors will present a case study on practical lessons learned through lab and pilot plant scale up of an intensified methodology for production of Mannich detergents. The study includes the minimization of heat and mass transfer limitations through novel unit operations, and the development of a kilo-scale continuous manufacturing unit. Finally, the authors will discuss practical considerations for modular unit scale up and deployment including OSBL infrastructure, raw materials, unit siting, controls integration, intermodal shipment, and financial analysis.