Toluene methanol alkylation to produce p-xylene fluidized bed catalyst and preparation method thereof

Abstract

The invention discloses a p-xylene fluid catalyst prepared by performing alkylation of methylbenzene methyl alcohol and a preparation method of the p-xylene fluid catalyst. The p-xylene fluid catalyst is prepared by modeling mixed spray of ZSM-5, matrix and amorphous binding agent, modifying by alkaline-earth metals, non-metals or / and rare earth metals and modifying by a siloxy group compound to prepare corresponding catalysts. The catalyst is used in methylbenzene methyl alcohol alkylation reaction; based on full conversion of methanol, methylbenzene conversion rate is more than 20 percent, and the once through yield of p-xylene in the product is up to 25 percent.

Description

technical field [0001] The invention belongs to the technical field of chemical engineering, and relates to a fluidized bed catalyst for p-xylene, in particular to a fluidized-bed catalyst for producing p-xylene by alkylation of toluene with methanol and a preparation method thereof. Background technique [0002] As the main raw material for PTA production, p-xylene (PX) is widely used in many fields. With the rapid development of my country's textile industry, the production capacity of PTA has expanded rapidly in recent years. PX is far from being able to meet the demand. Judging from the situation in recent years, about 40% of the domestic consumption of PX needs to be imported. [0003] In contrast to the insufficient production capacity of PX, there is currently a serious excess of domestic methanol production capacity. Due to the rapid development of the coal chemical industry in recent years, a large number of domestic coal-to-methanol plants have been built and operat...

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Problems solved by technology

[0007] Although these technologies reported above have obtained relatively high toluene conversion and PX selectivity, they have the following disadvantages: (1) the reaction is carried out on a fixed bed device, and the catalyst is not easy to regenerate; (2) toluene conversion and PX selectivity Cannot have both, and methanol conversion rate is not mentioned; (3) The molar ratio of water / (toluene+methanol) is too high, the energy consumption is extremely high, the waste water is more and difficult to handle; (4) The hydrogen reaction, and the ratio of hydrogen to hydrocarbon Too high, dangerous to operate, more waste gas, difficult to recycle hydrogen, high cost; (5) pressurized reaction, high requirements for equipment; (6) In addition, the patent CN101485994B is modified with precious metal Pt, which is expensive and difficult industrialization

However, the conversion rate of toluene on this catalyst is 20.1%, and the selectivity of PX is 99.1%, but the selectivity of xylene is only 65%, and the yield of PX is very low, only 12.95%.

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