Abstract: In the continuous purification of a propylene oxide feedstock contaminated with water, methanol and acetone wherein an acetone buffer is established in the column, normal distillation conditions are maintained or restored during or after an upset by continuously monitoring predetermined distillation conditions in the acetone buffer zone, and adding additional acetone to the extractive distillation column when the monitored distillation condition deviates from a predetermined value by a predetermined amount.

Abstract: Methyl tertiary butyl ether is prepared from contaminated TBA by reactively distilling the contaminated TBA in a reactive distillation column to provide a lower boiling isobutylene fraction and a higher boiling aqueous TBA fraction, by distilling the higher boiling aqueous TBA fraction to provide a lower boiling TBA fraction, by charging the lower boiling isobutylene fraction, the lower boiling tertiary butyl alcohol fraction and methanol to an etherification reactor to form an etherification reaction product, by distilling the etherification reaction product to provide a lower boiling fraction containing isobutylene, methanol and methyl tertiary butyl ether by charging the lower boiling fraction to a finishing reactor to react the isobutylene and methanol contained therein to from additional MTBE and by recovering MTBE from the etherification reaction product and the isobutylene conversion product.

Abstract: In the purification of an aqueous acetone-contaminated propylene oxide feedstock in an extractive distillation column in the presence of an oxyalkylene glycol extractive distillation agent under distillation conditions selected to promote the formation and maintenance of an acetone buffer in the distillation column, a higher boiling (heavier) distillation fraction containing substantially all of the oxyalkylene glycols, water, and acetone introduced into the extractive distillation column is continuously withdrawn and the higher boiling (heavier) distillation fraction is partially vaporized in a first reboiler; the remaining liquid being partially vaporized in a second reboiler and the vapors being recycled to the extractive distillation column.

Abstract: A heat exchanger is provided, including a tubular shell having an opening in one end thereof, an open-topped, side-slotted shroud mounted inside the shell, a bundle of tubes extending through the opening into the shroud, means for circulating a hot fluid through the bundle of tubes,means for charging a heat-exchange fluid to the space between the shell and the shroud for flow through slots into the shroud and into indirect heat exchange contact with the bundle of tubes for cooling the hot fluid, andmeans for removing heated exchange fluid from the top of said shell.