Technology device and method for preparing propylene by dehydrogenating propane or propane-enriched low carbon hydrocarbon

Abstract

The invention provides a technology device and method for preparing propylene by dehydrogenating propane or propane-enriching low carbon hydrocarbon. The device comprises a reacting / regenerating part and a product fractionating part. A reacting / regenerating system is divided into a parallel type arrangement scheme and a coaxial type arrangement scheme by a fluidized bed reacting / regenerating technology, wherein a raising pipe of the parallel type reacting / regenerating system is an internal or external raising pipe, and a raising pipe of the coaxial type reacting / regenerating system is an external raising pipe. The method comprises the steps: leading raw materials and reaction products to enter into a raising pipe reactor after heat exchange; performing a dehydrogenating conversion reaction under the conditions that the reaction temperature is 500-700 DEG C, the pressure is 0.1-0.4MPa, and the ratio of a microspherical catalyst to oil is 5-60, wherein the microspherical catalyst consists of chromium, rare earth oxides, alkali metal oxides and a gamma-Al2O3 carrier, preferably, the temperature is 550-670 DEG C, the pressure is 0.1-0.15MPa, and the ratio of the microspherical catalyst to oil is 6-14; leading the reaction products and the raw materials to enter into a gas-oil separator to separate a gas phase, a liquid phase from a water phase after heat exchange and cooling; leading the separated gas to enter into a gas compressor to be compressed and be transported to an absorbing / stabilizing part; pumping the liquid to an absorbing tower; transporting the liquefied gas from a return tank at the top of a stabilizing tower to a propylene / propane separating tower by a charging pump of a propylene tower; discharging the fine propylene separated from the top of the tower out of the device as a product; discharging the separated byproduct hydrogen out of the device; and returning products at bottom of the tower to the reacting / regenerating part to be recycled.

Description

Technical field [0001] The invention relates to a process for the dehydrogenation of low-carbon alkanes, and more specifically to a process device and method for producing propylene by the dehydrogenation of propane or low-carbon hydrocarbons rich in propane. Background technique [0002] Propylene is an important organic chemical raw material. In addition to being used to make polypropylene, it is also used in large quantities as the main raw material for the production of acrylonitrile, butanol, octanol, propylene oxide, cumene and nonylphenol. Oligomers are the main component to increase the octane number of gasoline. Unlike other chemicals, propylene is generally obtained through co-production or by-product. At present, about 70% of propylene in the world comes from the co-production of steam cracking to ethylene, and 28% from refineries are mainly by-products of catalytic cracking units. However, the steam cracking method is restricted by the ratio of propane / ethylene co-pr...

AI Technical Summary

Problems solved by technology

The content of this aspect is not involved in the existing technology at present, and the relevant use of chromium, rare earth oxides, alkali metal oxides / γ-Al 2 o 3 There is no report on the riser circulating fluidized bed process device and method of microsphere catalyst

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