(430f) Batch to Continuous Transition for Production of Dispersants in a Hydrodynamic Cavitation Reactor

Production of large volume specialty chemicals to-date is conducted almost exclusively in large volume batch reactors. Transition to much smaller continuous processing technology offers the prospect of strong improvements (so-called “process intensification”) over the century-old batch technology it terms of lower capital cost, smaller physical footprint of the plant, improved heat and mass transfer (and hence higher energy efficiency and lower operating cost), and better product quality and reduced waste production. This presentation will demonstrate these advantages using the production of succinimide dispersants as example. Lubricants and dispersants are a large class of specialty chemicals that constitute a ~$20B global market. Succinimide dispersants are well-suited for these studies due to their relatively simple chemistry and large production volume.

We had previously reported the intensification of succinimide dispersant production via transition from batch to continuous production in a conventional tubular reactor. We were able to demonstrate strong improvements in energy intensity, product quality, and plant size (and hence capital cost). In a next stage, we are currently evaluating the potential of “intensifying” this process via use of a hydrodynamic cavitation reactor. Cavitation reactors rely on the physical phenomenon of cavitation – i.e. the formation and rapid collapse of vapor bubbles in a liquid-phase reaction – to simultaneously heat and mix the reactive flow. It hence seems well-suited in particular to the processing of viscous reactive flows, as typical for dispersant production. However, despite their promise, cavitation reactors have found little to no use in chemical production to-date.

Here, we report on the initial results of investigating the use of a cavitation reactor for production of succinimide dispersants. We find that even prolonged exposure of the reactants (polymeric anhydrides and amines) to the high shear, high (local) temperature conditions inside a hydrodynamic cavitation reactor does not result in any detectable chemical or physical degradation of the reactants. More importantly, our results show that the cavitation reactor enables comparable yields to the conventional tubular reactor at drastically lowered inlet temperature (70^oC vs 160^oC), suggesting that strongly enhanced energy efficiency is attainable in this reactor. We complement these studies by a detailed analysis of the residence time distribution (RTD) spectrum in order to characterize the complex flow and mixing pattern inside this reactor.

Overall, our results suggest that cavitation reactors may constitute a promising, highly intensified reactor configuration for the processing of viscous mixtures in the specialty chemicals industry.