Bubble reactor with multiple layers of draft tubes and using method for bubble reactor

Abstract

The invention discloses a bubble reactor with multiple layers of draft tubes and a using method for the bubble reactor. The multiple layers of draft tubes are sleeved by a reactor shell; the diameter of each draft tube is different; the draft tubes are used for internally dividing the reactor shell into a plurality of stages of ring-shaped areas, height of the draft tubes is gradually reduced towords the outer side along the center; the draft tube located at the center communicates with a liquid inlet; the ring-shaped area at each stage and the draft tube located at the center communicate with a gas inlet; the ring-shaped area on the outermost layer communicates with a liquid outlet; and a gas outlet is formed in the top of the reactor shell. According to the reactor disclosed by the invention, liquid-phase cyclohexane overflows layer by layer, and oxygen molecule content of introduced air is improved stage by stage to carry out oxidation reaction, so that a mass transfer rate of oxygen can be sufficiently ensured to be matched with a reaction rate, and therefore, oxidation reaction can be stably and efficiently performed. The bubble reactor improves a flowing condition in the reactor, improves selectivity of a process, and can improve cyclohexane selectivity by 1.0%-2.5% in comparison with the prior art.

Description

technical field [0001] The invention relates to a multi-layer draft tube bubbling reactor and a using method thereof. Background technique [0002] To prepare cyclohexanol and cyclohexanone, cyclohexane is usually oxidized with a gas containing molecular oxygen, first to generate an oxidation mixture (cyclohexane oxidation solution) containing cyclohexyl hydroperoxide, cyclohexanol and cyclohexanone, and then treat This oxidized mixture decomposes the cyclohexyl hydroperoxide to generate cyclohexanol and cyclohexanone, and the reaction product undergoes repeated rectification to obtain cyclohexanol and cyclohexanone, and the cyclohexane is recycled. [0003] The cyclohexane oxidation reactor is generally a bubble tower, and internal components such as a draft tube can be added to the tower to improve mass transfer, and agitation can also be added. In the bubble column, it is generally not necessary to vigorously stir the liquid phase, the gas phase can be highly dispersed i...

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Problems solved by technology

However, this reactor also adopts multi-stage air intake. When air oxidation is used, because the gas contains a large amount of nitrogen, the gas holdup of the upper material in the straight barrel section will increase significantly, thereby deteriorating the flow state in the reactor; The gas from the gas distributor on the upper part of the straight barrel section of the device will escape from the liquid phase after a short period of time, and the oxygen content in the tail gas may exceed the safety limit due to the short residence time

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