Composite decarbonization solvent for eliminating carbon dioxide in natural gases

Abstract

The invention discloses a composite decarbonization solvent for eliminating carbon dioxide in natural gases, consisting of the following components in percentage by weight: 91.00%-96.45% of N-methyldiethanolamine solvent, 3.4%-8% of activator, 0.05%-0.4% of foam inhibiting agent, 0.05%-0.3% of corrosion inhibitor and 0.05%-0.3% of antioxidant. The invention has the advantages that the composite decarbonization solvent improves reaction rate of the composite decarbonization solvent and the carbon dioxide, increasing adsorption amounts; reduces circulation quantity of a decarbonization solution, decreasing energy consumption of solution circulation; reduces the degradation of the decarbonization solvent, lowering consumption of the decarbonization solvent; and at the same time, the composite decarbonization solvent improves corrosion resistance, oxidation resistance and foaming resistance of the decarbonization solution.

Description

technical field [0001] The invention relates to a decarburization solvent, in particular to a composite decarburization solvent for removing carbon dioxide in natural gas. Background technique [0002] At present, to remove carbon dioxide in natural gas, aqueous alcohol amine solution is commonly used as absorbent. The molecular structure of alcohol amine compounds contains at least one hydroxyl group and one amine group. The role of the former is to reduce the vapor pressure of the compound and increase its water solubility; while the latter provides the necessary alkalinity for the aqueous solution and promotes the absorption of acidic gas components. The alcohol amine solution reacts with the carbon dioxide in the natural gas to form carbamate and carbonate compounds, thereby purifying the natural gas. [0003] Most of the existing decarburization solvents use N-methyldiethanolamine as the main component. Since there is no active H atom in the molecule of N-methyldieth...

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Problems solved by technology

Since ethylenediamine derivatives are more alkaline than monoethanolamine, it is difficult to regenerate and restore, resulting in solvent loss and accelerating equipment corrosion

At the same time, monoethanolamine has a higher vapor pressure than other amines, high regeneration temperature, high evaporation loss, and high energy consumption; diethanolamine is unstable to thermal degradation and is prone to degradation loss during regeneration; piperazine has a low boiling point, Only 148°C, easy to volatilize, at the same time, the concentration of piperazine in the decarburization solution should not be too high, otherwise, the loss of solvent will be large, and the equipment and pipelines in contact with the decarburization solution will be severely corroded

[0006] The existing decarburization solvents also have the following disadvantages during use: N-methyldiethanolamine aqueous solution will degrade after absorbing carbon dioxide, oxygen and other acidic impurities in natural gas, resulting in solvent loss

At the same time, solvent degradation products, suspended solid particles, and free hydrocarbons carried in the raw natural gas in the decarburization solution will all cause foaming in the decarburization solution, resulting in disadvantages such as reduced decarburization effect and increased solution loss, and even cause decarburization. Carbon System Shutdown

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