(258g) Process Intensification Via Batch-to-Continuous Transition in the Production of Lubricants: Acquisition of Robust Reaction Kinetics

Authors: 
Al Azri, N., University of Pittsburgh
Sam-Gyandoh, E., University of Pittsburgh
Batchelder, S., University of Pittsburgh
Zhen, Z., University of Pittsburgh
Mantripragada, H. C., University of Pittsburgh
Enick, R. M., University of Pittsburgh
Kowall, C., The Lubrizol Corporation
Veser, G., University of Pittsburgh
Production of specialty chemicals to-date is conducted almost exclusively in batch or semi-batch reactors. Transition to continuous processing promises strong improvements—so-called “process intensification”—over the century-old batch processing technology with lower unit energy consumption, less waste generation, reduced exposure hazards, smaller process footprint, lower capital investment and more consistent product quality. The transition to continuous processing—already demonstrated widely at the much smaller scale of the pharmaceutical industry—thus offers the prospect of truly revolutionizing the manufacture of specialty chemicals.

As a first step, this transition requires the acquisition of robust information about the process chemistry. While batch reactors are highly tolerant to incomplete knowledge (in particular regarding kinetics), the design and operation of continuous processes requires availability of robust kinetics. However, the detailed chemistry and kinetics underlying current processes are in most cases poorly understood (if not completely unknown). Transition to continuous processing hence requires collection of robust and accurate kinetics as a key prerequisite, including impact of impurities and contaminants which play a significant role in many specialty chemicals processes.

This work presents results from a university-industry collaboration between Lubrizol Corporation and the University of Pittsburgh, under the umbrella of the recently formed RAPID Modular Chemical Process Intensification Institute. It aims to demonstrate the transition from batch to continuous processing focused on lubricant chemistry. Specifically, we present results from a kinetic investigation into the production of succinimide dispersants via reaction of a poly-isobutylene succinimide anhydride (PIBSA) with polyamines. The molecules undergo a condensation reaction to produce a large surfactant molecule with a polar head group and a long, oil soluble polymer tail. A complete family of products (which form the largest volume oil additives) is made by varying molecular weight, structure and stoichiometric ratio of the various reactants. However, the reaction kinetics for this class of reactions are unknown and the acquisition of robust kinetics is hence a crucial first step in the process development for a continuous process. We demonstrate that the combination of online IR spectroscopy as the analytical tool, with careful data evaluation (including model cross-validation techniques and analysis of transient traces) allows for the required acquisition of robust reaction kinetics and the identification of optimal operating windows for a continuous process.