Process for preparing propylene through combined reaction feeding and catalyst regeneration countercurrent contact dehydrogenation

Abstract

The invention discloses a process for preparing propylene by combined reaction feeding and catalyst regeneration countercurrent contact dehydrogenation, wherein the process comprises catalytic dehydrogenation and catalyst cyclic regeneration. According to the process, raw materials are heated by a heater, and the heated raw materials enter a first reactor, contact a catalyst, and are subjected toa catalytic dehydrogenation reaction; after the reaction is performed for a period of time, the temperature is reduced, the reaction speed is reduced, the process gas discharged from the first reactorenters the subsequent reactor through the heater to react with a catalyst, and the catalytic dehydrogenation reaction is circularly carried out multiple times; and finally the product gas dischargedfrom the terminal reactor enters a separation system and is separated to obtain the final product propylene, wherein the to-be-regenerated catalyst participating in the reaction in the first reactor is collected through a catalyst collector, is lifted to a separation hopper through a fan, and is elutriated and burnt to obtain a catalyst capable of being recycled, then the catalyst is lifted and sent back to the terminal reactor, and then the catalyst sequentially flows into all stages of the reactors to participate in reaction, so that catalyst circulation is realized.

Description

technical field [0001] The invention relates to a process for producing propylene by dehydrogenation of propane, in particular to a process for producing propylene by countercurrent contact dehydrogenation of combined reaction feed and catalyst regeneration. Background technique [0002] At present, there are two main processes for propane dehydrogenation to propylene in the world, namely the UOP process in the United States and the Lummus process in the United States. [0003] The main difference between the two processes is mainly in the catalyst. The Lummus process fixed bed uses chromium-based catalysts, which are toxic and difficult to dispose of after the catalyst is scrapped. The UOP process uses a platinum-based catalyst, which is non-toxic, has good thermal stability, and low investment, which is why it currently occupies a relatively large domestic market share. [0004] UOP process: After mixing propane with a certain proportion of hydrogen, it passes through th...

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Problems solved by technology

[0005] The above-mentioned UOP process has a short operating cycle, and the terminal reactor is easy to block, which affects the operating cycle and other shortcomings.

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