Purification method of hydrocyanic acid

A purification method and technology of hydrocyanic acid, applied in the direction of cyanic acid/isocyanic acid, sustainable manufacturing/processing, climate sustainability, etc., can solve reboiler and tower body corrosion, high safety risks, and increase investment Cost and operating costs, etc., to ensure reliability, eliminate aggregation, and shorten residence time

Inactive Publication Date: 2012-08-15
CHONGQING UNISPLENDOUR CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although this purification method solves the problem of frequent polymerization of hydrocyanic acid, it is only suitable for purifying hydrocyanic acid solutions with a concentration of more than 50%. For low-concentration hydrocyanic acid solutions, such as 1-10%, it is necessary to concentrate before rectification , thus increasing the investment cost and operating cost; moreover, the operating pressure and temperature during the rectification and purification process of this method are relatively high, which will lead to severe corrosion of the reboiler and the tower body
In addition, its pressurization operation, equipment manufacturing and distillation system have strict requirements. If there is any leakage, hydrocyanic acid will flow into the environment, which poses a great safety risk

Method used

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  • Purification method of hydrocyanic acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] A method for purifying hydrocyanic acid. The purified raw material is prepared by using water as an absorbent to absorb hydrogen cyanide in the hydrogen cyanide synthesis gas produced by the Angle method in an absorption tower. The specific composition is mass percent Content (w / w, the same below) as the following hydrocyanic acid solution: HCN 2.10%, water 97.75%, H 2 SO 4 0.15%; Its rectifying tower adopts the rectifying tower that the diameter is 1200 mm and is filled with acid-resistant ceramic filler, and this rectifying tower has 22 trays altogether, wherein 15 rectifying sections, 7 stripping sections; The purified raw material flows through the feed heater at a flow rate of 12050kg / hour and is heated to 55°C, and then the seventh tray from the bottom enters the rectification column, the temperature at the top of the tower is 19.6°C, and the pressure at the top of the tower is The negative pressure of 80 KPa, the tower still temperature is 94.2 ℃, the tower sti...

Embodiment 2

[0021] A method for purifying hydrocyanic acid, the specific composition of its purified raw materials is as follows: hydrocyanic acid solution: 10.0% HCN, 89.65% water, H 2 SO 4 0.35%; heated to 40°C in the feed heater; the pressure at the top of the tower is a negative pressure of 90 KPa, the temperature of the top of the tower is 25°C, the temperature of the bottom of the tower is 60°C, the pressure of the bottom of the tower is a negative pressure of 95 KPa, reflux The ratio is 15; the purified raw material is added at a flow rate of 12050kg / hour, and the polymerization inhibitor SO is added in an amount of 2.5 liters / hour in the hydrogen cyanide gas steamed from the gas phase outlet pipeline at the top of the tower 2 (gaseous state), add mass concentration in the reflux liquid by the amount of 1.1kg / hour and be that the phosphoric acid aqueous solution of 80% is made polymerization inhibitor, other equipment requirements, operating requirements etc. are the same as embo...

Embodiment 3

[0023] A method for purifying hydrocyanic acid, the specific composition of its purified raw materials is as follows: hydrocyanic acid solution: 8.50% HCN, 91.15% water, H 2 SO 4 0.35%; heated to 50°C in the feed heater; the pressure at the top of the tower is 10 KPa negative pressure, the temperature at the top of the tower is 23.5°C, the temperature of the tower bottom is 90°C, the pressure of the bottom bottom is 90 KPa negative pressure, reflux The ratio is 3; the purified raw material is added at a flow rate of 12050kg / hour, and the polymerization inhibitor SO is added in the amount of 2.5 liters / hour in the hydrogen cyanide gas steamed from the gas phase outlet pipeline at the top of the tower 2 (gaseous state), add mass concentration in the reflux liquid by the amount of 1.0kg / hour and be that 85% formic acid aqueous solution is made polymerization inhibitor; Other equipment requirements, operating requirements etc. are the same as embodiment 1, finally obtain the speci...

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Abstract

The invention relates to a purification method of hydrocyanic acid. In the method, a purification raw material adopts 1-10% by weight of hydrocyanic acid water solution. The purification method comprises the following steps of: preheating the purification raw material to 40-60 DEG C, then introducing into a rectifying tower, adding a polymerization inhibitor, and performing distillation under the conditions that the tower top pressure is 10-90KPa negative pressure, the tower top temperature is 0-25 DEG C, the tower kettle pressure is 20-95KPa negative pressure, the tower kettle temperature is 60-100 DEG C and the reflux ratio is 3-15 so as to realize refining and purification of the hydrocyanic acid. The whole device comprises a vacuum pump which is connected with a reflux tank for operating and used for maintaining the negative pressure in the tower, and the trace hydrocyanic acid contained in exhaust gas of the vacuum pump is sent to an incinerator for incineration treatment. According to the purification method disclosed by the invention, the pressure difference between the tower top and the tower kettle is reduced, the operation temperature is reduced, the corrosion of all the devices can be avoided or reduced, and the polymerization of the hydrocyanic acid is further eliminated, thus the quality of a hydrocyanic acid product and the yield thereof are further improved; and the purification method has the characteristics that the purification method is more economic, energy-saving, environment-friendly and safer.

Description

technical field [0001] The present invention relates to the refining and purification of hydrocyanic acid, in particular to a method for purifying hydrocyanic acid. Background technique [0002] Hydrocyanic acid is a weakly acidic, highly toxic, highly volatile colorless liquid, but it is also an important basic chemical substance, mainly used in the production of methyl methacrylate, adiponitrile, sodium cyanide, amino acids (such as methionine), chelating agents (EDTA, DTPA, etc.), yellow blood salt sodium / potassium, herbicides (such as glyphosate), dyes (such as indigo, etc.), medicines (such as antibiotics), fluorescent whitening agents, reactive dyes , Pesticides, etc. [0003] There are three main methods for producing hydrocyanic acid on an industrial scale: 1) Andrussow method (Annstadt method), that is, under the action of a catalyst, methane, ammonia and air / oxygen react quickly to synthesize hydrogen cyanide gas at a high temperature of 1000-1200 °C The mixture ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01C3/14
CPCY02P20/10
Inventor 方善伦杨君奎姜国富王理
Owner CHONGQING UNISPLENDOUR CHEM
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