METHOD FOR PRODUCING A TREATED NATURAL GAS, A CUT RICH IN C3+ HYDROCARBONS AND OPTIONALLY AN ETHANE-RICH STREAM, AND ASSOCIATED FACILITY
First Claim
1. A method for simultaneously producing a treated natural gas, a cut rich in C3+ hydrocarbons and under at least certain production conditions, an ethane-rich stream, from an initial natural gas stream containing methane, ethane and C3+ hydrocarbons, the method comprising the following steps:
- cooling and partly condensing the initial natural gas stream in at least one first upstream heat exchanger in order to form a cooled initial stream;
separating the cooled initial gas stream into a liquid flow and a gas flow;
expanding the liquid flow, and introducing a stream stemming from the liquid flow into a column for recovering C2+ hydrocarbons at a first intermediate level;
forming a stream for feeding a turbine from the gas flow;
expanding the feed stream in a dynamic expansion turbine and introducing it the expanded feed stream into the recovery column at a second intermediate level;
recovering and compressing at least one portion of the head stream of the recovery column in order to form the natural gas and recovering the foot stream of the recovery column in order to form a C2+-hydrocarbon-rich liquid stream;
introducing the liquid stream at a feed level (P1) of a fractionation column provided with a head condenser, the ethane-rich stream being produced under said production conditions, from a stream stemming from the fractionation column, the fractionation column producing a foot stream intended to at least partly form the C3+ hydrocarbon cut;
introducing a primary reflux stream produced in the head condenser with reflux into the fractionation column;
producing a secondary reflux stream from the head condenser and introducing the secondary reflux stream at the head of the recovery column,sampling a recycling stream in the head stream stemming from the recovery column;
establishing a heat exchange relationship of the recycling stream with at least one portion of the head stream stemming from the recovery column,reintroducing, after expansion, the cooled and expanded recycling stream into the recovery column,sampling in the bottom of the recovery column of at least one bottom reboiling stream,establishing a heat exchange relationship of the bottom reboiling stream with at least one portion of the initial natural gas or/and with the recycling stream,ensuring the bottom reboiling by the calories taken from the initial natural gas stream or/and from the recycling stream.
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Accused Products
Abstract
The method includes the following steps, sampling a recycling stream (152) in a head stream (131, 140, 141) stemming from a recovery column (35), establishing a heat exchange relationship of the recycling stream (152) with at least one portion of the head stream (131) stemming from the recovery column (35), reintroducing, after expansion, the cooled and expanded recycling stream into the recovery column (35). The method includes sampling in the bottom of the recovery column (35) of at least one bottom reboiling stream (165), and establishing a heat exchange relationship of the re-boiling stream with at least one portion of the initial natural gas (13) or/and with the recycling stream (152), the bottom reboiling being ensured by the calories taken from the initial natural gas stream (13) or/and from the recycling stream (152)
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Citations
19 Claims
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1. A method for simultaneously producing a treated natural gas, a cut rich in C3+ hydrocarbons and under at least certain production conditions, an ethane-rich stream, from an initial natural gas stream containing methane, ethane and C3+ hydrocarbons, the method comprising the following steps:
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cooling and partly condensing the initial natural gas stream in at least one first upstream heat exchanger in order to form a cooled initial stream; separating the cooled initial gas stream into a liquid flow and a gas flow; expanding the liquid flow, and introducing a stream stemming from the liquid flow into a column for recovering C2+ hydrocarbons at a first intermediate level; forming a stream for feeding a turbine from the gas flow; expanding the feed stream in a dynamic expansion turbine and introducing it the expanded feed stream into the recovery column at a second intermediate level; recovering and compressing at least one portion of the head stream of the recovery column in order to form the natural gas and recovering the foot stream of the recovery column in order to form a C2+-hydrocarbon-rich liquid stream; introducing the liquid stream at a feed level (P1) of a fractionation column provided with a head condenser, the ethane-rich stream being produced under said production conditions, from a stream stemming from the fractionation column, the fractionation column producing a foot stream intended to at least partly form the C3+ hydrocarbon cut; introducing a primary reflux stream produced in the head condenser with reflux into the fractionation column; producing a secondary reflux stream from the head condenser and introducing the secondary reflux stream at the head of the recovery column, sampling a recycling stream in the head stream stemming from the recovery column; establishing a heat exchange relationship of the recycling stream with at least one portion of the head stream stemming from the recovery column, reintroducing, after expansion, the cooled and expanded recycling stream into the recovery column, sampling in the bottom of the recovery column of at least one bottom reboiling stream, establishing a heat exchange relationship of the bottom reboiling stream with at least one portion of the initial natural gas or/and with the recycling stream, ensuring the bottom reboiling by the calories taken from the initial natural gas stream or/and from the recycling stream. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 16, 17)
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13. A facility for simultaneously producing a treated natural gas, a cut rich in C3+ hydrocarbons, and under certain production conditions, an ethane-rich stream, from an initial natural gas stream containing methane, ethane and C3+ hydrocarbons, the facility comprising:
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an assembly for cooling and partly condensing the initial natural gas stream comprising at least a one first upstream heat exchanger in order to form a cooled initial stream; an assembly for separating the cooled initial stream into a liquid flow and into a gas flow; a column for recovering C2+ hydrocarbons an assembly for expanding the liquid flow, and for introducing a stream stemming from the liquid flow into the recovery column at a first intermediate level; an assembly for forming a stream for feeding the turbine from the gas flow; an assembly for expanding the feed stream, comprising a dynamic expansion turbine and an assembly for introducing the expanded feed stream into the recovery column at a second intermediate level; an assembly for recovering and compressing at least one portion of the head stream of the recovery column in order to form the natural gas and an assembly for recovering the foot stream of the recovery column in order to form a liquid stream rich in C2+ hydrocarbons; a fractionation column provided with a head condenser, an assembly for introducing the liquid stream at a feed level of the fractionation column, the ethane-rich stream being able to be produced under said production conditions, from a stream stemming from the fractionation column, the fractionation column being able to produce a foot stream intended to form at least partly the C3+ hydrocarbon cut; an assembly for introducing a primary reflux stream produced in the head condenser with reflux into the fractionation column; an assembly for producing a secondary reflux stream from the head condenser and an assembly for introducing the secondary reflux stream at the head of the recovery column, an assembly for sampling a recycling stream in the head stream of the recovery column; an assembly for establishing a heat exchange relationship of the recycling stream with at least one portion of the head stream stemming from the recovery column, an assembly for reintroducing, after expansion, the recycling stream into the recovery column, an assembly for sampling in the bottom of the recovery column at least one bottom reboiling stream, and an assembly for establishing a heat exchange relationship of the bottom reboiling stream with at least one portion of the initial natural gas or/and with the recycling stream, the reboiling being able to be ensured by the calories taken from the initial natural gas stream or/and from the recycling stream. - View Dependent Claims (14, 15, 18, 19)
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Specification