A method for converting carbon tetraolefins to propylene by catalytic cracking or cracking process

Abstract

The invention discloses a method for converting carbon-4 olefin into propylene through a catalytic cracking or pyrolysis process. The technical method comprises the following steps: (1) directly putting the etherified carbon-4 into a reactor, and performing hydration reaction with water to generate a corresponding alcohol; (2) performing regular distillation on the reactor outlet material to obtain the alkane on the tower top and the corresponding alcohol on the tower bottom; and (3) taking the tower bottom material as the raw material for cracking and increasing the propylene, and reentering to a catalytic cracking riser reactor to perform cleavage reaction. A mass separating agent (water) which does not influence the consequent reaction without separation is added, the alkane and the olefin separation process is reinforced, the olefin component with high reactivity is high selectively reprocessed under the condition without separating the mass separating agent. The problem of efficient separation of the alkane and the olefin in the traditional process is solved and the target of increasing the yield of the propylene is realized through reprocessing. The original device is utilized and the utilization rate of the olefin is increased under the condition of low investment.

Description

technical field [0001] The present invention relates to a method for converting carbon tetraolefins into propylene by catalytic cracking or cracking process. It belongs to the field of deep processing of liquefied gas and efficient utilization of petroleum resources, and is especially suitable for producing propylene by using mixed C4 by-product of catalytic cracking unit. Background technique [0002] Propylene is an important petrochemical raw material. With the continuous development of new varieties of downstream derivatives of propylene, the demand for propylene has been strong in recent years. At present, 54% of propylene in my country comes from steam cracking of naphtha, and 42% of propylene is a by-product of catalytic cracking unit. Compared with the world, my country's FCC by-product propylene occupies an important position. There are many catalytic cracking units in China, and the adaptability of raw materials is strong. The potential of catalytic cracking proc...

AI Technical Summary

Problems solved by technology

When the method of ordinary rectification is used to process C4, since the boiling points of the components of butene and butane in C4 are similar, the separation of ordinary rectification methods has a large reflux ratio, a large number of trays, high energy consumption, and poor operation. The problem of high investment costs

When extractive distillation technology is used, there are problems such as low yield of butene; complicated process and difficult operation; extraction agent is mixed in the separated product butene; large solvent ratio and large amount of extraction agent are used.

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