Patent Awarded to Charlie Bolthrunis and Domenic Ferrari of CCTI on Behalf of ExxonMobil
September 2010
Oxygenate-to-Olefin Conversion in a Baffled Reactor
[excerpt]
The invention concerns methods and systems for minimizing back-mixing of feedstock flow in converting oxygenates to olefins. In one embodiment, back-mixing is reduced by providing a reactor that includes baffles to reduce the hydraulic diameter of at least a portion of the reactor. Some or all of the baffles can also serve as cooling tubes for reducing temperature gradients in the reactor, and thereby maximize light olefin production.
In industrial scale reactions for hydrocarbon to olefin conversion, the desired products are typically lighter olefins such as ethylene and propylene. In addition to controlling the overall conversion rate and the light olefin selectivity, it can also be desirable to control the ratio of ethylene to propylene produced by a reaction. A further consideration in conversion reactions is the cost required to perform the conversion reaction. A conventional reactor for performing a controlled oxygenates-to-olefin reaction can require multiple risers nearly 200 feet in height and hundreds of tons of catalyst for converting the oxygenate feedstock.
US Pat No 6,166,282B1 discloses a process for converting oxygenates to olefins in a reactor with two reaction zones. Feedstock is introduced into a lower, sense phase zone from a single inlet to effect a partial conversion to light olefins. The sense phase zone...
