Heat integration process.

摘要

A portion of the heat of vaporization, required to separate and recover methanol from wash water used to remove methanol from a C4 raffinate resulting from the reaction of isobutene containing C4 hydrocarbons and methanol to produce MTBE is recovered by conducting the distillation of the methanol/water mixture at a pressure of 40 to 60 psig, thereby increasing the temperature of the methanol overhead to 104 to 114 DEG C and using the reaction effluent from the MTBE reactor to cool and condense the methanol overhead, said reactor effluent being correspondingly heated prior to entry into a debutanizer tower where unreacted C4's and methanol are removed as a raffinate and MTBE product recovered. It is this raffinate that is washed with water to recover the unreacted methanol, with the methanol/water mixture being distilled as set forth above. In another embodiment a stream having a lower temperature than the methanol overhead is withdrawn from the debutanizer and used to cool the methanol overhead, then the correspondingly heated stream returned to the debutanizer.