SU1745314A1 - Method of recovering carbon dioxide from gases - Google Patents

Abstract

This invention relates to the field of gas cleaning. To increase the carbon dioxide yield and reduce equipment corrosion rate, a surfactant is introduced into the aqueous ammonia solution; the VGS flotation reagent is the bottom residue of the production of secondary fatty alcohols in the following ratio, wt.%: Ammonia 4-5, surfactant 1-3, water the rest. 1 silt, 1 tab.

Description

The invention relates to the oil and gas industry and the chemical industry, in particular to the purification of gas from carbon dioxide.

A known method of purifying gases from acidic components by absorption with methanol, and the absorption by methanol is carried out in the presence of sodium hydroxide and ammonia in an amount of 5-200 mol / l of methanol.

There is also known a method for producing carbon dioxide from gases by flushing the gas with a liquid mainly consisting of methanol and undergoing regeneration, in order to eliminate undesirable absorption of hydrocarbons and to achieve the economic efficiency of the method, the regenerated liquid should contain ammonia in a concentration of 0.5% by weight.

The closest technical solution is a method for producing carbon dioxide from coke oven gas. According to the method, the gas to be purified is fed to the absorber, and ammonia water is supplied to the stream of gas to be purified, the solution is saturated with carbon dioxide with agitation of ammonia water with ammonia water, and then fed to the regeneration column, heat exchanger and stripping column, in which the acidic is removed. gases, the regenerated solution again enters the absorber.

The disadvantage of this method is its lack of efficiency due to the low rates of the reaction between components and equipment corrosion.

The aim of the invention is to increase the yield of carbon dioxide by means of VSCO. The extent of the reaction is the interaction between the SNM and C02 and the reduction in corrosion of the equipment.

This goal is achieved by the absorption of carbon dioxide from gases with a solution containing the following components, wt.%:

Ammonia4-5

VHS flotation reagent (vat

production balance

higher fatty acids) 1-3

WaterEverything

The use of the invention will provide the following advantages: an increase in the yield of C02 by 2 times; decrease in 8-9

(L

WITH

&

CO Ј

corrosive destruction times of the metal; low investment and energy costs, for example, through the use of equipment for integrated gas treatment plants using the invention in the gas industry.

The proposed method differs from the known one in that the surfactant is added to the ammonia water — the flotation agent VHS — the bottoms residue of the production of higher fatty acids, which is a catalyst for accelerating the reaction in the production of carbon dioxide from gases.

The method is carried out as follows.

Natural gas with a CO2 content of 4.2% in the amount of 120 thousand m3 / day, purified from dropping liquid, enters the horizontal absorber 1. Here, ammonia absorption solutions with a flow rate of 1 m3 / h are supplied from tank 4 by pump 3 under pressure of 3 MPa the compositions of which are presented in the table.

In the absorber 1, ammonia solutions are saturated for 20 minutes with carbon dioxide, carbonized and fed through heat exchanger 5 to regeneration column 6, where carbon dioxide is released from the solution and heated with dull steam, with a bottom temperature of 90 ° C, top 40 ° C, regeneration pressure 0.4 MPa.

five

The carbon dioxide produced is sent to a collection tank, and the regenerated ammonia solution, through the heat exchanger 5, is returned to the absorber 1.

The corrosion rate of steel in the test solutions, measured in the regeneration column by the gravimetric method using witness samples for 48 hours in the presence of VGS flotation reagent, decreases 8-10 times.

The table summarizes the results of carbon dioxide production from natural gas by absorption using formulations with different content of ingredients.

Claims (1)

Claims A method for producing carbon dioxide from gases, including absorption of ammonia with an aqueous solution and regenerating a saturated solution by heating, characterized in that, in order to increase the yield of carbon dioxide, the VHS fluorescent is additionally added to the aqueous solution of secondary fatty alcohols. the ratio of components, wt.%: Ammonia4-5 Flotation reagent VZhS 1-3 WaterEverything ,five eleven 2 4 O 1 2 3 4 O 1 2 . h it About 1 2 3 C O one 2 3 four 97 96 95 9 93 96 95 94 93 92 95.5 94.5 93.5 92.5 91.5 95 9 93 91 91 94 93 92 91 90 39.7 47.5 60 66 79 8.4 7.60 7.31 -7.33 7.52 8.70 7.86 7.53 7.60 7.69 9.03 7.86 7.42 7.50 7.79 9.20 7 , 8 7.31 7.52 7.60 9.31 8.04 7.80 8.30 8.8 2.40 0.30 0.29 0.29 0.28 2.57 0.32 0.30 0.30 0.29 2.65 0.32 0.30 0.30 0.30 2.70 0.33 0.30 0.30 0.30 2.78 0.34 0.33 oh, zh 0.32 Dropping out carbonates ammonium