Method for removing HCN in CO2 raw gas

Abstract

The invention discloses a method for removing HCN in CO2 raw material gas, which comprises that: the HCN in the CO2 raw material gas prepared from coal, natural gas, heavy oil or residual oil and in the CO2 raw material gas prepared from flue gas in a power plant, limekiln gas, wine-making and bio-fermentation gas or biochemical gas, and the like through separation and extraction is converted into N2 or NH3 and CO2 or CO so as to remove virulent HCN. A HCN transforming and removing catalyst is a transition metal zinc-magnesium or zinc-copper or copper-magnesium loaded HCN removing catalyst using ferric oxide as a carrier. The temperature for removing HCN of the catalyst is selected within the range between 5 and 400 DEG C; airspeed is selected within the range between 500 and 10,000 / hour;and pressure is selected within the range between 0.1 and 15 MPa. The method for removing the HCN is applied to the CO2 raw material gas, has the HCN conversion rate more than 95 percent and can meetrequirement of deep processing of CO2 and in particular meet requirement of purification of CO2 in food level.

Description

Technical field: [0001] The invention belongs to the field of fine chemical industry and relates to CO produced from coal, natural gas, heavy oil or residual oil. 2 Raw material gas, power plant flue gas, lime kiln gas, wine making and bio-fermentation gas, and biochemical gas, etc., after separation and extraction of CO 2 The removal method of the highly toxic substance HCN in the raw material gas. Background technique: [0002] Food CO 2 Widely used in beverage, vegetable-food preservation, welding, tobacco industry and other fields. CO in recent years 2 The output shows a trend of rapid growth, with an annual increase of 15-25%, especially in industrial and mining enterprises such as synthetic ammonia, methanol, power plants, lime kilns, and biological fermentation, where there is a large amount of excess CO 2 emission, the greenhouse effect is significant. Food CO 2 Both of the above CO 2 Gas is processed and refined as raw material gas, so food CO 2 The developm...

AI Technical Summary

Problems solved by technology

The removal technology research of HCN is few at present, and the removal HCN catalyst that Chinese patent CN1404900, CNCN1404904, CN1404905 and CN1416950 etc. announce is mainly precious metal catalysts such as platinum rhodium; CN1462652 has announced a kind of Al 2 o 3 It is the method for removing HCN by supporting Cu catalyst on carrier; CN1564710 has announced a kind of COS and / or HCN hydrolysis catalyst, and this catalyst is made from titanium oxide supported alkaline earth metal sulfate, has two kinds of catalytic functions of COS hydrolysis and HCN hydrolysis, and the hydrolysis rate Both are above 90%, but the catalyst carrier chooses relatively expensive titanium oxide

CN101050389 discloses a catalyst that can simultaneously hydrolyze HCN and COS used in coal-based gas, which uses an active alumina carrier to support transition metal cobalt-molybdenum, or iron-molybdenum, or nickel-molybdenum and basic metal oxides The hydrolysis conversion catalyst, the catalyst has sulfur resistance, but it needs to have 50~100×10 -6 h 2 S or organic sulfur can maintain its stable performance, so it cannot remove HCN in sulfur-free or low-sulfur feed gas.

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