Method for Preventing Dew Point Corrosion of Maleic Anhydride Cycle Tail Gas

Abstract

The invention provides a method for preventing dew point corrosion of a recycled maleic anhydride tail gas. In the presence of a catalyst, n-butane is oxidized by virtue of an oxygen gas to produce a maleic-anhydride-containing vapor-phase matter which is cooled and absorbed to form a tail gas, part of the tail gas is recycled to be mixed with the oxygen gas or oxygen-rich air, the mixture serving as raw material is input so as to participate in the circulation reaction of the n-butane, so that the product material consumption is lowered, and the dew point corrosion is prevented, and thus, the economical efficiency of equipment is improved.

Description

technical field [0001] The present invention provides a kind of gas-phase material containing maleic anhydride generated from the oxidation of n-butane under the action of catalyst by oxygen, which is cooled and absorbed to form tail gas, which is partially recycled to reduce product consumption and prevent gas cycle dew point corrosion, thereby Improve device economy. Background technique [0002] Maleic anhydride (referred to as maleic anhydride MA) is also known as maleic anhydride and dehydrated malic anhydride. It is an important organic chemical raw material and fine chemical product. It is the third largest acid anhydride in the world after phthalic anhydride and acetic anhydride. Mainly used in the production of unsaturated polyester resin (UPR), alkyd resin, but also in the production of 1,4-butanediol (BDO), γ-butyrolactone (GBL), tetrahydrofuran (THF), maleic acid, rich A series of important organic chemicals and fine chemicals such as malic acid and succinic a...

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Problems solved by technology

However, due to the addition of pure oxygen or enriched oxygen, it is easy to form explosive mixtures with n-butane. How to properly add pure oxygen or enriched oxygen to avoid the formation of explosive mixtures is not described in detail in these patents, so the above patented technologies are lacking in industry. Possibility to implement

[0007] US5688970 describes another tail gas circulation process for producing maleic anhydride by oxidation of n-butane. The concentration in the gas composition of the reactor during the oxidation is 10-18%. In fact, it is also an oxygen-poor oxidation process. The following obvious disadvantages: due to the reduction of oxygen concentration, the conversion rate of n-butane is greatly reduced, so that the single-pass yield of maleic anhydride is greatly reduced, resulting in a substantial reduction in the production capacity of the device

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