| 主权项 |
1. A process for making isoprene comprising:
dehydrogenating a feed comprising isobutane in a dehydrogenation zone under dehydrogenation conditions to form a mixture comprising isobutene, and isobutane and separating the mixture into a liquid effluent stream and a gaseous effluent stream; separating the liquid effluent stream in a depropanizer into an overhead vapor stream comprising C3− hydrocarbons and a depropanizer stream comprising the isobutene, and isobutane; introducing the depropanizer stream into an isoprene reaction zone, the depropanizer stream having a concentration of isobutene of at least about 40%; reacting the isobutene with formaldehyde in the isoprene reaction zone to form a mixture comprising isoprene, isobutene, and isobutane, wherein a conversion of isobutene to isoprene is less than 99%; separating the mixture from the isoprene reaction zone into a product stream comprising isoprene and an isoprene effluent stream comprising isobutene, and isobutane; recovering the product stream comprising isoprene; introducing the isoprene effluent stream to an etherification zone; reacting the isobutene with methanol in the etherification reaction zone to form a mixture comprising methyl tert-butyl ether, isobutene, and isobutane; separating the mixture from the etherification zone into a product stream comprising methyl tert-butyl ether and an effluent stream comprising isobutene, and isobutane; removing oxygenated compounds from the effluent stream in an oxygenate removal zone forming an effluent stream with a reduced level of oxygenated compounds; and reacting isobutene from the effluent stream with the reduced level of oxygenated compounds with hydrogen in a saturation zone to form an isobutane stream comprising isobutane. |
