RU97116008A - METHOD GAS PROCESSING METHOD FOR AT LEAST ONE HIGHER HYDROCARBON AND WATER - Google Patents

Claims (16)

1. The method of processing a gas containing methane, at least one higher hydrocarbon and water, characterized in that it contains the following stages:
a) the treated gas is divided into two streams (1) and (2);
b) at least overflow (2) of said gas is brought into contact with a recycled liquid phase containing both water and a solvent, which is usually an organic, non-hydrocarbon, usually liquid, but not water, capable of at least partially mix with water and undergo distillation at a temperature below the distillation temperature of the water, with the possibility of obtaining an aqueous liquid phase depleted in solvent content compared with the recycled liquid phase, and a gas phase containing solvent;
c) the solvent phase depleted of the solvent phase is separated from the gas phase containing the solvent;
d) the solvent-depleted aqueous phase is brought into contact with the stream (1) of said solvent-free gas, and in the contact zone, the residual solvent is extracted from the water-depleted phase with the gas to be treated, and at this stage a solvent-rich gas phase is obtained and a regenerated aqueous liquid phase;
d) the solvent-rich gas phase formed in step (d) is mixed either with the gas-containing solvent phase formed in step (b) or after step (b) with the gas (2) obtained from step (a) and solvent free;
f) the gas phase of the mixture is cooled with the possibility of its partial condensation in the aqueous and hydrocarbon phases, each of which contains a solvent, and receive a treated gas from which water and higher hydrocarbons are removed at least partially;
g) the aqueous and hydrocarbon phases formed in stage (e) are separated by settling;
h) the aqueous, solvent-rich phase is recycled to stage (b).  2. The method according to p. 1, characterized in that at stage (a) the volume of gas in the stream (2) exceeds the volume of gas in the stream (1).  3. The method according to p. 1 or 2, characterized in that the gas phase rich in solvent content formed in stage (d) is mixed with the gas phase rich in solvent content formed in stage (b) of the process.  4. The method according to p. 1, characterized in that at the end of the contacting stage (c) the entire amount of the treated gas is brought into contact in stage (b) with a rich solvent content of the recycled aqueous phase.  5. The method according to one of paragraphs. 1-4, characterized in that at the end of the contacting stages (b) and (d), a solvent is added to the gas phase to prevent the formation of hydrates in the cooling step (e) and to compensate for the loss of solvent in the treated gas.  6. The method according to one of paragraphs. 1-5, characterized in that the solvent is selected from the series formed by methanol, ethanol, propanol, methylpropyl ether, ethylpropyl ether, dipropyl ether, methyl tertiary butyl ether, dimethoxymethane, dimethoxyethane and methoxyethanol.  7. The method according to p. 6, characterized in that the solvent is methanol.  8. The method according to one of paragraphs. 1-7, characterized in that the aqueous phase rich in solvent content recycled to stage (b) contains 50 to 95% by weight of the solvent. 9. The method according to one of paragraphs. 1-8, characterized in that the temperature of the gas phase at the end of stage (e) is from -15 to -80 ^o C and that the resulting gas at the end of stage (d) is purified from most of the propane contained at the beginning of the process.  10. The method according to one of paragraphs. 1-9, characterized in that the volume of gas passed through the contact zone in stage (g) is 25 - 95% of the amount of gas being treated.  11. The method according to one of paragraphs. 1-9, characterized in that the volume of gas passed through the contact zone in stage (g) is 30-50% of the amount of gas to be treated.  12. The method according to one of paragraphs. 1-11, characterized in that the hydrocarbon liquid phase formed in stage (g) is subjected to stabilization in order to remove volatile components from it.  13. The method according to one of paragraphs. 1-12, characterized in that the hydrocarbon liquid phase formed in stage (g) is subjected to washing in order to extract solvent from it.  14. The method according to p. 13, characterized in that the washing of the hydrocarbon liquid phase is carried out by the regenerated aqueous phase formed in stage (g), from which the drain stream is formed with the possibility of maintaining the amount of solvent and water in the circuit at a significantly constant level.  15. The method according to p. 13, characterized in that the stage of washing the hydrocarbon liquid phase is carried out by means of mixer-settlers.  16. The method according to p. 13, characterized in that the stage of washing the carbon liquid phase is carried out by contacting in a column.