Stepwise condensation process for catalytic cracking absorbing-stabilizing system

Abstract

The invention relates to the producing craft of catalysis crack absorption stabilizing system, including step condensation craft and its composite craft with middle reboiler. The characteristic of step condensation craft are: after mixed, the compressed rich gas, rich absorption oil and desorption gases directly get into balance kettle to have gas-liquid separation, then step cool condensable oil and non-condensable gases, the condensable oil gets into the middle and upside of desorption tower as hot feed after slightly cooled, and the non-condensable gases get into the top of desorption tower as cold feed after cooled to a lower temperature. The step condensation craft and its composite craft has two-gate feed characteristic, which avoids back-mix. Under same feed, operating condition and production specification, compared with two-tower flow normal craft, it's the cool load before balance kettle is greatly reduced, which are respectively reduced by 48.6%, 39.5%; the load of desorption tower reboiler of the composite craft is reduced by 37.3% than cold feed craft.

Description

technical field [0001] The invention relates to a petroleum refining process, in particular to a step-by-step condensation process of a catalytic cracking absorption stabilization system. Background technique [0002] With the development of the economy, energy saving and product quality improvement are the most concerned issues in the oil refining industry. In the 1960s, the old catalytic cracking absorption and stabilization units were all single-tower processes, and their disadvantage was that C in the lean gas at the top of the tower was 3 C in gasoline with high content and bottom deethanization 2 High content. In the 1980s, most of these old devices changed the single-tower process to a double-tower process, avoiding the disadvantages of the single-tower process. [0003] The feeding methods of the double-tower process desorption tower mainly include cold feed, hot feed and cold and hot double-strand feed. [0004] The characteristic of the cold feed process is tha...

AI Technical Summary

Problems solved by technology

In the 1960s, the old catalytic cracking absorption and stabilization units were all single-tower processes, and their disadvantage was that C in the lean gas at the top of the tower was 3 C in gasoline with high content and bottom deethanization 2 high content

However, since the condensed oil with different temperatures and the same composition enters different positions of the tower respectively in this process, there is axial back-mixing, which reduces the driving force, adversely affects mass transfer, and reduces efficiency

[0007] For conventional hot feed and double-feed feed, a large amount of gas-liquid mixture first drops to 40°C, and then the condensed oil will be heated to 80°C through stable gasoline and enter the top of the desorption tower. This "cooling first and then heating" process It is actually a kind of energy loss, which is unreasonable

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