Device and method for performing olefin gaseous phase epoxidation by using industrial hydrogen peroxide

Abstract

The invention belongs to the technical field of organic chemical catalytic synthesis, which relates to a device and a method for performing olefin gaseous phase epoxidation by using industrial hydrogen peroxide. A reactor casing of the device is made of metal materials, the inner wall contacted with the hydrogen peroxide is passivated through acid solution, or the inner wall is coated with hydrogen peroxide inert materials. The processed raw material enters a reactor to perform reaction along with feeding materials of the olefin raw material, diluent gas, auxiliaries and the like, and after reacted materials pass through a separation unit, unreacted olefin raw material, the diluent gas and auxiliaries circulate back to the reactor. The device and the method directly use industrial hydrogen peroxide products, overcome bottlenecks of low efficiency, fast catalytic agent inactivation and poor regeneration repeatability of in-situ hydrogen peroxide preparation, are strong in raw material adaptability, safe and high in efficiency, few in gaseous phase epoxidation reactive by-product, simple in separation and high in catalyst stability.

Description

technical field [0001] The invention belongs to the technical field of catalytic synthesis of organic chemicals, and relates to a device and method for gas-phase epoxidation of olefins by using industrial hydrogen peroxide under the catalytic action of an epoxidation catalyst. Background technique: [0002] Organic epoxy compounds such as ethylene oxide, propylene oxide and epichlorohydrin, etc., have chemically active three-membered oxygen rings, and are a type of typical basic organic chemical synthesis intermediates. It is widely used in petrochemical, fine chemical and organic synthesis fields. [0003] The current production process of ethylene oxide is the direct gas-phase epoxidation of ethylene and molecular oxygen using a silver catalyst with excellent performance. The technology and economy of the process are advanced, and the production process is basically pollution-free. For propylene oxide, the current production methods are mainly the chlorohydrin method and...

AI Technical Summary

Problems solved by technology

The problem that this method exists is: the use of a large amount of solvents causes the generation of a large amount of by-products, and then the selectivity of epoxide is reduced, and industrial input cost increases further

The problem that this method exists is: use a large amount of liquid solvents in the reaction, and the use of alkali metal and ammonium source causes serious pollution to environment simultaneously

Problems in this method: (1) the use of a large amount of organic solvents in the coupling process; (2) the coexistence of hydrogen, oxygen, hydrogen peroxide and organic solvents in the reaction process, which further increases the risk of industrial operation; (3) in the process During the in-situ generation of hydrogen oxide and the epoxidation of olefins, if calculated according to the amount of anthraquinone used and the amount of hydrogen peroxide produced, the yield of propylene oxide is very low (only 5%)

But the problem that this system exists is: (1) molecular oxygen and hydrogen in situ generate the efficiency of hydrogen peroxide on said catalyzer is low, and is the rate control step of whole reaction; (2) catalyst preparation difficulty is very big; ( 3) Molecular oxygen and hydrogen are chemically activated on the noble metal catalyst at the same time. It is difficult to control the conditions, and it is easy to generate a large amount of water, and it is easy to hydrogenate a large amount of propylene into propane, resulting in a very low utilization rate of raw materials. Low

The problem with this method is that it still cannot get rid of the limitation of using a large amount of liquid reagents, and the resulting separation problem is too difficult and complicated

The problems of this method are: (1) the catalyst is easily deactivated; (2) the preparation of the catalyst containing titanium is difficult; (3) the utilization rate of hydrogen is very low, which is not conducive to the realization of industrial production

The main problem of this method is that in this catalytic system, although the catalyst can have better catalytic activity and selectivity by controlling the particle size of the gold particles, the life of the catalyst can only be maintained for several hours, and it cannot be regenerated.

The main problem that this method exists is: propylene conversion rate only reaches 1.5%, and propylene oxide productive rate is only 35~37gPOKg simultaneously -1 cath -1 , still unable to meet the requirements of industrialization

The main problem that this method exists is: no matter be the conversion ratio of propylene or the selectivity of propylene oxide all can't satisfy industrialization requirement

The main problem that this method exists is: (1) the selectivity of propylene oxide is relatively low; (2) reaction energy consumption is high; (3) can't realize large-scale industrialized production at present

The problem that this method exists is: (1) the hydrogen peroxide purity that plasma produces can reach electronic level, and the price is expensive, is used for producing propylene oxide, and economic benefit is not high; (2) energy consumption is high; (3) due to current Limitations of plasma technology, engineering conditions for large-scale industrialization of this method are not yet mature

The main problem that this method exists: (1) microchannel reactor is expensive, and industrial input cost is high, is not suitable for large-scale industrialized production; (2) reaction product is easily polymerized and blocked in reaction channel; (3) adopts falling film evaporator Vaporizing hydrogen peroxide will intensify its own decomposition reaction, resulting in further loss of raw material liquid

But these methods generally face the problem that the utilization rate of hydrogen is very low, which limits the rate of the entire epoxidation reaction, so there is still a long way to go before realizing large-scale industrialization

However, centrifugal atomization also relies on the booster gas to send the material liquid to the high-speed rotating atomization disk for atomization. Like the pressure direct atomization, the power consumption of the reaction process is large, and the raw material gas is excessively diluted, which reduces the reaction efficiency.

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