PRODUCTION OF PROPYLENE FROM BUTANE.

摘要

This invention relates to an integrated process for the efficient production of olefins from C4 feedstocks comprising butane and more particularly to a method of producing propylene and butadiene. The process combines a dehydrogenation unit with an olefin conversion unit to convert butane feedstock to propylene and butadiene products. The combined catadiene-OCT process produces yields of propylene from normal butane in excess of 70%. An exemplary two-stage prosthetic heart valve system has a radially expandable base stent implanted within a native valve annulus. The base stent desirably has three position markers projecting in the axial direction from the outflow end of the base stent to assist in aligning the stent with respect to the commissures of the native valve. The two-stage heart valve system also has a valve component that is delivered to and mounted within the base stent in a separate or sequential operation after the base stent has been anchored within the annulus. The valve component in certain embodiments comprises a hybrid valve component that includes a conventional, non-expandable surgical valve that is modified to include an expandable coupling stent that can be expanded to engage the inner surface of the base stent, thereby anchoring the valve component to the base stent. This invention relates to an integrated process for the efficient production of olefins from C4 feedstocks comprising butane and more particularly to a method of producing propylene and butadiene. The process combines a dehydrogenation unit with an olefin conversion unit to convert butane feedstock to propylene and butadiene products. The combined catadiene-OCT process produces yields of propylene from normal butane in excess of 70%.