Preparation method of catalyst layer in microchannel reactor

Abstract

The invention discloses a preparation method of a catalyst layer in a microchannel reactor, comprising the following steps: 1), pretreating an inner wall of a microchannel: flushing with an alkaline solution; 2), preparing a dopamine coating: injecting a prepared dopamine solution into the microchannel, flushing with deionized water, drying, and cooling for use; 3), non-electrochemically depositing a catalyst: fully filling the microchannel with a precursor solution containing catalyst anions, heating, continuously introducing the precursor solution, and flushing with deionized water; 4), reducing with a catalyst: placing the reactor in a resistance furnace, evacuating the resistance furnace, charging nitrogen, introducing hydrogen after secondary evacuation, introducing the hydrogen continuously, heating to 50-200 DEG C, maintaining reduction reaction for 4-8 hours, and cooling before extraction. Catalyst ionic distribution can be reduced, utilization rate is increased, a catalytic layer high in reaction activity and long in life is prepared in the microchannel, and the performance of the reactor is improved and the life thereof is prolonged significantly.

Description

technical field [0001] The invention relates to a method for preparing a catalyst layer in a reactor, in particular to a method for preparing a catalyst layer in a microchannel reactor. Background technique [0002] In various common chemical reactors including tank reactors, tower reactors, fixed bed reactors, fluidized bed reactors, etc., due to the existence of a large mass transfer resistance between phases, the reaction rate will be greatly affected . In order to overcome this shortcoming, the reaction pressure and temperature are usually increased to further overcome the mass transfer resistance and strengthen the reaction. However, this often increases manufacturing costs and increases the potential risk of explosion. Accordingly, researchers have proposed a microreactor from the perspective of strengthening interphase material transfer and shortening the transfer path, and studies have proved (JutaK, YuichiroM, KuniakiO, etal.Science, 2004, 304(5675): 1305-1308 .)...

AI Technical Summary

Problems solved by technology

The catalytic layer prepared by the sol method will cause the catalytic layer to delaminate and fall off due to coating swelling and other reasons during use, resulting in a waste of catalyst and a sharp decline in the performance of the reactor. In severe cases, the reactor may even fail completely. use; in addition, the sol will cover a large number of catalyst particles, so that the active area is covered so that no catalytic effect can be produced, resulting in limited utilization of the catalyst

The catalytic layer prepared by the impregnation reduction method usually has good catalytic activity, but the roasting process (>400°C) is usually required in the preparation process, which puts forward higher requirements for the selection of materials for the preparation of microchannels, and also will increase the processing cost

Although the electroless deposition method has been reported, it is not enough to completely reduce the adsorbed ionic catalyst due to the weak reducing ability of the surface of the polydopamine layer that acts as bonding and reducing respectively, which greatly causes the catalyst to be damaged. Waste will also reduce the life and performance of the reactor itself

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