Известия Томского политехнического университета: Инжиниринг георесурсов (Feb 2023)
TECHNOLOGICAL PARAMETERS OF THE PROCESS FOR NATURAL GAS EFFECTIVE ABSORPTION DRYING FROM MOISTURE USING DIETHYLENGLYKOL
Abstract
Relevance. The extraction of natural and associated petroleum gases is accompanied by the necessary gas preparation for delivery to the consumer for commercial use. In particular, in gas and oil fields, the separation of all side homologues of methane, moisture and other non-hydrocarbon compounds that are part of associated petroleum gases, which worsen the operating conditions of equipment and lower the quality of the feedstock, are used. With the ever-increasing degree of water cut in gas and oil fields, it is necessary to progressively develop technological methods for gas treatment, including one of the most common in the Russian Federation – the absorption method of drying natural and associated petroleum gases from water impurities. Purpose: to substantiate the use of diethylene glycol in preparation of natural gas, as the most effective absorbent in the Far North. Object: complex natural gas treatment unit. Method. The calculation of the model of the complex gas treatment unit was carried out in the UniSim Design R470 software package. Results. The influence of the main technological parameters: temperature, pressure of absorption drying of natural gas on the absorbent diethylene glycol at the gas treatment plant for the removal of water impurities is investigated. The optimal pressure and temperature conditions for effective removal of moisture from natural gas by the method of water absorption by diethylene glycol at high pressure of the input raw material are determined. It is shown that the use of diethylene glycol absorbent is most effective in the conditions of the Far North. When diethylene glycol is used as an absorbent for drying natural gas from water at low temperatures, the energy consumption for gas compression, its cooling in front of the absorber, and the consumption of the dryer are significantly reduced compared to other absorbents. The most effective technological parameters of the operation of an absorption plant for drying natural gas at a diethylenglykol concentration of 98 % wt. and raw natural gas consumption of 385 thousand m³/h were determined. Diethylenglykol already at a contact temperature of 19 °C dries the gas to the regulated dew point temperature of minus 20 °C and pressure in the gas treatment unit of at least 4 MPa and above. On the contrary, exceeding the gas–diethylenglykol contact temperature above 20 °С and lowering the pressure below 4 MPa lead to a significant increase in energy consumption, the entrainment of the diethylene glycol absorbent and the deterioration of the economic indicators of the natural gas drying from water impurities.
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