Low-temperature micro-oxygen purification method for removing harmful gas in yellow phosphorus tail gas

Abstract

The invention provides a micro-oxygen purifying method used for removing harmful gas in yellow phosphorus tail gas, which is characterized in that mixed gas containing HCN, PH, H2S, COS and CS2, with the speed of 1000-5000 / h is heated to 150-200 DEG C by a heat exchanger and sent to a catalytic hydrolysis reactor; more than 90% of HCN and 85% of COS and CS2 can be respectively hydrolysed as NH3, CO, H2S and CO2; subsequently, the mixed gas enters a selective catalytic oxidation reaction; PH3 and H2S are catalysed and oxidated as P2O5 and S; harmful gas in the mixed gas which is disposed twice is removed further in a fine decyanation reactor and the sulfide thereof is removed by a fine desulfurization reactor; NH3 is selectively catalysed and oxidated as N2, thus purifying the mixed gas. The method of the invention leads the violent toxic matter to be converted into non-toxic matter, generates no secondary pollution, recovers the outgrowth sulphur, improves the utilization ratio of the resource, eliminates the environmental pollution due to waste gas exhausting, and has the advantages of simple process, few investment and low running expense.

Description

technical field [0001] The invention relates to a method for simultaneously removing toxic and harmful gases hydrogen cyanide (HCN) and phosphine (PH) from yellow phosphorus tail gas. 3 ), carbonyl sulfide (COS), hydrogen sulfide (H 2 S), carbon disulfide (CS 2 )Methods. Background technique [0002] The main component of yellow phosphorus tail gas is CO, impurity H 2 1% ~ 8%, O 2 0.5%~1%,H 2 O 1%~5%, CH 4 0.3%, N 2 1%~5%, HCN 100~350mg / Nm 3 ,PH 3 750~1200mg / Nm 3 , H 2 S 800~1100mg / Nm 3 , COS 700~1000mg / Nm 3 , CS 2 20~80mg / Nm 3 . HCN and PH in yellow phosphorus tail gas 3 It is not only a highly toxic gas that is harmful to the environment and endangers human health, but also restricts production process control, safe production and comprehensive utilization of waste. These impurities can lead to poisoning of the oxo catalyst. The yellow phosphorus tail gas must be removed when used as a carbon chemical raw material gas. At present, most of the yellow ...

AI Technical Summary

Problems solved by technology

These impurities can lead to poisoning of carbonylation catalysts, and the yellow phosphorus tail gas must be removed when used as a carbon chemical raw material gas. At present, most of the yellow phosphorus tail gas is burned and discharged, and the effective utilization rate is less than 30%.

The process of this method is more complicated and the adaptability is poor

[0007] The removal process mentioned in the above patent is only for one or two kinds of toxic and harmful gases, and cannot simultaneously remove HCN, PH 3 , COS, H 2 S and CS 2 Especially in the current shortage of chemical raw materials and rising oil prices, the rational use of yellow phosphorus tail gas as a carbon chemical raw material gas has important practical significance

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