Catalyst for preparing pyromellitic dianhydride from durene through gaseous catalytic oxidation and preparation method thereof

Abstract

The invention relates to a catalyst for preparing pyromellitic dianhydride from durene through gaseous catalytic oxidation and a preparation method thereof, belonging to the technical field of catalytic oxidation. The catalyst is characterized by comprising V2O5, TiO2 and P2O5, wherein the molar ratio of V2O5 to TiO2 to P2O5 is 1:3.750-15.000:0.125-0.313. The catalyst provided by the invention has the advantages of low airspeed, low energy consumption, high selectivity and high weight gain percentage during application, is helpful to energy saving and resource consumption reduction and is beneficial to increasing the yield and the purity of pyromellitic dianhydride and reducing the production cost for preparing pyromellitic dianhydride through gaseous catalytic oxidation. The provided preparation method of the catalyst has simple and succinct technological steps and can ensure the overall embodiment of the effect of the catalyst.

Description

technical field [0001] The invention belongs to the technical field of catalytic oxidation, and relates to a catalyst for preparing pyromellitic dianhydride by gas-phase catalytic oxidation of durene, and also relates to a preparation method of the catalyst. Background technique [0002] Pyromellitic dianhydride (PMDA for short) is an important organic chemical product intermediate with high added value, which is mainly used in the production of engineering plastics, coating additives, plastic additives Because of its excellent insulation performance, high and low temperature resistance and mechanical properties, PMDA is widely used in many fields such as electromechanical, aerospace and electronic industries. [0003] There are many industrial production methods of PMDA, such as gas-phase air catalytic oxidation, liquid-phase air oxidation, nitric acid oxidation and chromic acid oxidation, etc., but gas-phase catalytic oxidation is the main method. Since the gas-phase cata...

AI Technical Summary

Problems solved by technology

The system has many catalyst active components, and the preparation process is relatively complicated, requiring a high space velocity of about 6000-10000h-1. Meanwhile, the yield of PMDA is also low, and the weight yield is only 84%-100%.

[0009] Chinese patent CN 1321543A discloses a catalyst for producing PMDA by gas-phase oxidation of durene, which can be produced by V 2 o 5 、TiO 2 , Nb 2 o 5 、Cs 2 O and P 2 o 5 and other active components can also be composed of V 2 o 5 、TiO 2 , Nb 2 o 5 、Na 2 O and B 2 o 3 However, the active components of the two catalytic systems are relatively complex, and the Nb 2 o 5 It is difficult to dissolve in water, and it is easy to cause uneven catalytic components in the spraying process

High space velocity and high furnace temperature restrict the actual production of PMDA, which not only causes excessive energy consumption and increases production costs, but also affects the purity of PMDA to a certain extent

In addition, the production of PMDA in my country has long had defects such as backward technology, low yield of crude anhydride, and low purity. At the same time, due to the constraints of actual production and process conditions, the yield of PMDA cannot be greatly improved.

Images