First to apply microreactor in the production of butyl rubber
Cenway is the first to apply microreactor technology with patent on the production of synthetic rubber which substantially enhance the production efficiency as well as dramatically lower the energy consumption. A microreactor is a device in which chemical reactions take place in a confinement with typical lateral dimensions below 1 mm; the most typical form of such confinement is microchannels.
The traditional production technology of butyl rubber is cationic polymerization under -100 ℃ in the reaction with liquid ethylene and liquid propylene to keep the required low temperature. The heat transfer efficient continues to decrease along with the going on of the reaction until the reaction is stopped and the reactor is switched. The whole process consumes a huge amount of energy. Microreactors offer many advantages over conventional scale reactors, including vast improvements in energy efficiency, reaction speed and yield, safety, reliability, scalability, on-site/on-demand production, and a much finer degree of process control. Microreactors typically have heat exchange coefficients of at least 1 megawatt per cubic meter per kelvin, up to 500 MW m−3 K−1 vs. a few kilowatts in conventional glassware (1 l flask ~10 kW m−3 K−1). Thus, microreactors can remove heat much more efficiently. Hot spot temperatures as well as the duration of high temperature exposition due to exothermicity decreases remarkably. Thus, microreactors may allow better kinetic investigations, because local temperature gradients affecting reaction rates are much smaller than in any batch vessel. Heating and cooling a microreactor is also much quicker and operating temperatures can be as low as −100 °C.
As a result of the superior heat transfer, reaction temperatures may be much higher than in conventional batch-reactors. The benefits here are primarily enabled by the mass transfer, thermodynamics, and high surface area to volume ratio environment as well as engineering advantages in handling unstable intermediates.