RU2296793C2 - Unit for preparation of hydrocarbon gas for transportation - Google Patents

Abstract

FIELD: gas, petrochemical and other industries.

SUBSTANCE: proposed unit includes the following components connected in succession by gas route: intake separator 1, scrubber 3, first compression stage 4, air cooling apparatus 5, intermediate separator 6, gas high drying set 7, second compression stage 8, second air cooling apparatus 9 and second intermediate separator 10. Gas outlet of second intermediate separator 10 is connected with gas and condensate transportation pipe line and with inlet of fuel gas preparation set 11 of gas-turbine drive. One outlet of preparation set 11 is connected with inlet for delivery of fuel gas to gas-turbine engines and second outlet is connected with inlet for delivery of reactivation gas to gas high drying set 7. Pipe line for escape of reactivation gas from gas high drying set 7 is connected with delivery pipeline of first compression stage 4 in front of air cooling apparatus 5. Proposed unit makes it possible to improve quality of gas and condensate by water dew point during preparation for transportation.

EFFECT: high degree of cleaning gas from toxic admixtures; increased service life of compressor equipment; reduced capital outlays; improved quality of gas and condensate.

1 dwg

Description

The invention relates to techniques for preparing hydrocarbon gases for transport to plants for further processing to produce marketable products and can be used in gas, petrochemical and other industries.

A known unit for the preparation of hydrocarbon gas included in the installation of low-temperature condensation and comprising a separator for separating solid and liquid impurities from the gas, a compressor, an air gas cooler, heat exchangers, a propane evaporator and a separator for separating condensate from the gas. Gas from the installation is supplied to the main pipeline, and condensate is sent for further processing (Berlin MA, Gorechenkov VG Processing of oil and natural gases. M., Chemistry, 1981, p.168).

Common features of the known and proposed installations are:

- compressor

- gas refrigerator,

- separators.

However, the known installation is characterized by high capital costs and does not provide a high degree of gas purification from mechanical impurities and dropping liquid (oil, condensate, water, etc.).

Closest to the technical nature of the proposed installation is a hydrocarbon gas preparation unit containing a compressor of two stages of compression, a gas refrigerator, a scrubber, a separator for separating gas from a liquid connected to the scrubber. The unit is equipped with a recuperative heat exchanger, an intermediate separator and an air cooler, the gas inlet to the recuperative heat exchanger is connected to the gas outlet from the compressor, and the gas outlet from the recuperative heat exchanger is connected to the gas inlet to the gas refrigerator, while the water outlet from the water recirculation tank is additionally connected to the water inlet into a recuperative heat exchanger, the water outlet from which is connected through an intermediate separator and an air cooler to a water recirculation tank. The installation is additionally equipped with a separator installed at the gas outlet from the gas refrigerator and connected to the gas inlet to the scrubber (RF patent No. 2224581, IPC B01D 53/00, F25J 3/08, publ. 02.27.04).

Common features of the known and proposed installations are:

- compressor of two stages of compression,

- gas refrigerators,

- scrubber,

- intermediate separators.

A disadvantage of the known installation is the need for additional units for drying gas and gas condensate to the dew point in accordance with the requirements of regulatory documents or the conditions for further processing and, in addition, a unit for the preparation of fuel gas for a gas turbine drive (GTP) of gas pumping units used to compress gas.

The technical task is to increase the degree of purification of gas from harmful impurities that cause corrosion, increase the life of compressor equipment, reduce capital and operating costs and improve the quality of gas and condensate in preparation for transport to the processing plant, as well as improve the quality of the fuel gas of the gas turbine engine.

The claimed invention allows to solve the problems due to the fact that in the installation for the preparation of hydrocarbon gas for transport, comprising a receiving separator, a compressor unit of two stages of compression, a scrubber, air cooling devices (gas refrigerators), intermediate separators, a scrubber are placed in front of the first stage of compression, and between the first and second steps installed block deep gas dehydration.

The installation, in addition to the gas outlet to the gas and condensate transport pipeline, is provided with an additional outlet to the fuel gas preparation unit, from which gas is taken for the gas turbine drive and for regeneration of the adsorbers of the deep-drying unit. To this end, the outlet from the fuel gas preparation unit is connected to the inlet of the regeneration gas into the deep-drying unit, and the pipeline for the outlet of regeneration gas from the deep-drying unit is connected to the discharge pipe of the first compression stage in front of the air-cooling unit, which allows using the main equipment of the unit to remove moisture from regeneration gas without the use of special equipment for this purpose. This reduces capital costs. In addition, the process of adsorption and regeneration under one pressure reduces the wear of the sorbent, increasing its service life, which leads to lower operating costs.

The drawing shows a schematic flow diagram of an installation for the preparation of hydrocarbon gas for transport.

The installation comprises a receiving separator 1, to the inlet of which hydrocarbon gas is supplied, while the output of the separator 1 is connected to the drainage tank 2 in the liquid phase and to the scrubber 3 in the gas phase. The inlet of the drainage tank 2 is also connected to the scrubber 3 in the liquid phase. The output of the gas phase of the scrubber 3, having a separation device necessary for separating the dropping liquid, is connected to the inlet of the first stage of compression 4, the output of the first stage is connected to the inlet of the air cooler 5, the output of which is connected to the intermediate separator 6. The output of the intermediate separator 6 condensate is connected to the inlet of the drainage tank 2. The gas phase output of the intermediate separator 6 is connected to the inlet of the deep (to the dew point minus 70 ° C in water) drying 7, which consists of three well-functioning adsorbers, gas purification filters, a recuperative heat exchanger, and a regenerative gas heating furnace (Keltsev N.V. Fundamentals of adsorption technology. M., Chemistry, 1976; Kempbel D.M. Purification and processing of natural gases. M., "Nedra", 1977, p. 262). The outlet of the dried gas from the deep-drying unit 7 is connected to the suction pipe of the second compression stage 8, the discharge pipe of which is connected through the second air-cooling apparatus 9 to the inlet of the second intermediate separator 10, the gas outlet from the second intermediate separator 10 and the liquid phase outlet (dry condensate) are connected with transport pipeline for gas and condensate. Additionally, the gas outlet from the second intermediate separator 10 is connected to the inlet of the gas treatment unit GTP 11. One outlet from the gas treatment unit GTP 11 (fuel gas) is connected to the inlet of gas turbine engines, the other (regeneration gas) to the deep-drying unit 7. The recovery gas outlet pipe from the deep-drying unit is connected to the discharge pipe of the first compression stage 4 in front of the air cooling apparatus 5.

Installation works as follows. At the inlet of the separator 1 is a hydrocarbon gas. After preliminary separation, the liquid phase is supplied to the drainage tank 2, and the gas phase is sent for cleaning to the scrubber 3, from where the purified gas enters the first stage (low pressure) of compression 4 of the two-stage compressor and after cooling the compressed gas in the air cooling apparatus 5 enters the intermediate separator b to separate the condensate, which is piped to the drainage tank 2. Gas from the intermediate separator 6 is sent to the deep drying unit 7, which consists of three alternating operations constituents adsorbers gas purifying filters, the recuperative heat exchanger and the furnace heating regeneration gas.

Each adsorber is in one of three modes: drying, heating, cooling. The adsorbers are switched automatically by opening and closing the corresponding valves according to a predetermined algorithm.

For regeneration purposes, at a given flow rate, gas is sampled at the outlet of preparation unit 11, which is throttled to a pressure that ensures gas is returned to the discharge line of the first stage of compression 4. The gas selected for regeneration purposes passes through a cooled adsorber, a tube space of a regenerative heat exchanger, a furnace where it is heated to a temperature of 300-330 ° C, a heated adsorber, the annular space of the regenerative heat exchanger and is dumped into the discharge line of the first compression stage 4 in front of the app by air cooling 5. The dried gas from the deep-drying unit 7 is fed to the inlet of the second compression stage 8 and through the discharge pipe and the second air-cooling device 9 to the inlet of the second intermediate separator 10, from where a part of the deep-drying gas is sent to the fuel gas preparation unit of the gas-turbine drive 11 The main gas stream of deep drying and the liquid phase (dry condensate) from the second intermediate separator 10 are sent through a gas and condensate transport pipeline for processing.

Claims (1)

A hydrocarbon gas preparation unit for transport, comprising a receiving separator, a compressor unit with two stages of compression, a scrubber, air cooling apparatuses and intermediate separators, characterized in that it is equipped with a deep gas dehydration unit and a gas turbine drive fuel gas preparation unit, and a receiving gas outlet the separator is connected to the inlet of the scrubber, the gas outlet of which is connected to the suction pipe of the first compression stage, the discharge pipe of the first compression stage it is connected through an air cooling apparatus to an intermediate separator, the gas outlet of the intermediate separator is connected to the inlet of the gas deep dehydration unit, the outlet of the dried gas from the gas deep dehydration unit is connected to the suction pipe of the second compression stage, the discharge pipe of the second compression stage is connected through the second air cooling device to the inlet of the second intermediate separator, the gas outlet of the second intermediate separator is connected to the transport pipeline of gas and condensate and with the input of the fuel gas preparation unit of the gas turbine drive, while one exit from the fuel gas preparation unit of the gas turbine drive is connected to the input of the fuel gas supply to the gas turbine engines, the second output is connected to the input of the regeneration gas supply to the deep gas dehydration unit, the regeneration gas outlet pipeline from the block gas dehydration is connected to the discharge pipe of the first stage of compression in front of the air cooling apparatus.