Method and apparatus for removing nitrogen from cryogenic hydrocarbon composition

FIELD: technological processes.

SUBSTANCE: invention relates to method and device for removing nitrogen from cryogenic hydrocarbon composition. At least first part of cryogenic hydrocarbon composition is supplied into nitrogen desorption column. Nitrogen desorption column operates under desorption pressure. In nitrogen desorption column desorbing steam is supplied, containing at least stripping part of compressed process steam, which was produced from nitrogen-depleted fluid, in which pressure was released after its removal from nitrogen desorption column. Reverse irrigation is formed with participation of nitrogen desorption column head partially condensed steam by means of heat transfer from head steam to auxiliary coolant flow in amount of cooling efficiency. Exhaust gas consisting of non-condensed steam fraction from head steam, is removed. Cooling efficiency is adjusted to control of discharged steam fraction calorific capacity.

EFFECT: technical result is possibility of discharged steam fraction calorific capacity control.

20 cl, 2 dwg, 3 tbl

 



 

Same patents:

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the method of production of liquid CO2 from gaseous combustion products. Furnace gas is compressed in the first compressor, then it is cooled in the first cooler and is partially condensed at two separation steps. Two separation steps are cool by the expanding flue gas and the expanding liquid CO2. The second separation step includes the second heat exchanger and CO2 stripper in which the flow of liquid CO2 from the first separation step is supplied into the CO2 stripper directly and CO2 flow from the first separation step is supplied into the CO2 stripper through the second heat exchanger. Liquid CO2 in the stripper is boiled by the reboiler and from the top part of CO2 stripper flue gas is separated, expanded in the pressure control valve and is used in separation steps for cooling. Also liquid CO2 from the reboiler and CO2 stripper is collected in the buffer drum.

EFFECT: increase of purity of liquefied CO2 without increase of power consumption.

12 cl, 5 dwg, 1 tbl

FIELD: oil and gas industry.

SUBSTANCE: invention group refers to method of carbon dioxide-containing natural gas treatment. Treatment method involves natural gas separation by cryogenic process and can produce liquid carbon dioxide flow at one side and purified natural gas flow at another side. One part of natural gas is cooled in a first heat exchanger and then in a second heat exchanger before the cryogenic process and/or before return to the cryogenic process. One part of liquid carbon dioxide is returned to obtain recycled carbon dioxide flow. Recycled carbon dioxide flow is divided into the first and second portion. First portion is expanded, then heated in the first heat exchanger to obtain first flow of heated carbon dioxide. Second portion is cooled, then at least one part of the second portion is expanded and heated in the second heat exchanger to obtain second flow of heated carbon dioxide. Some hydrocarbons contained in the first and second flows of heated carbon dioxide are separated by gas and liquid separation. Invention claims installation for implementation of the method as well.

EFFECT: reduced hydrocarbon loss during cryogenic separation.

11 cl, 2 tbl, 1 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to method of removing fraction with high nitrogen content. Described is method of removing fraction with high hydrogen content from initial fraction, which contains mainly nitrogen and hydrocarbons, with initial fraction being separated by method of rectification into fraction with high nitrogen content and fraction with high methane content in order to obtain cold is evaporated and overheated under possibly maximal pressure with respect to initial fraction to be cooled. In accordance with invention still liquid or partially evaporated fraction with high methane content is supplied to circulation tank, liquid portion of fraction with high-methane content formed in circulation tank preferably in the process of natural circulation is completely evaporated, and head main product of circulation tank is overheated.

EFFECT: invention is aimed at reliable and stable evaporation of fraction with high nitrogen content.

7 cl, 4 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to a method of separating C2+-hydrocarbons from a starting fraction primarily containing nitrogen and hydrocarbons. The disclosed method includes: a) the starting fraction is partially condensed and fractionally divided into C2+-hydrocarbon impoverished and rich fractions; b) the C2+-hydrocarbon impoverished fraction is partially condensed and divided into a liquid fraction which forms at least a partially reverse stream for fractional separation, and a C2+-hydrocarbon impoverished gaseous fraction; c) the C2+-hydrocarbon impoverished gaseous fraction is divided in a double-column process into a nitrogen-rich and a methane-rich fraction. The liquid fraction obtained at step (b) is also at least partially fed into the double-column process and divided therein into a nitrogen-rich and a methane-rich fraction.

EFFECT: invention is aimed at improving the efficiency of separating C2+-hydrocarbons.

4 cl, 3 dwg

FIELD: chemistry.

SUBSTANCE: method and device of liquefaction of a gaseous flow, which contains hydrocarbons and acidic compounds, and in which the acidic compounds are removed in a liquefied state, when the gaseous flow, purified from the acidic compounds is gradually cooled to the liquefaction temperature. The method includes cooling the gaseous flow in such a way as to obtain the cooled gaseous flow, containing gaseous hydrocarbons and residual acidic compounds. After that, the obtained gaseous flow, purified from the acidic compounds, is additionally cooled to obtain liquid hydrocarbons.

EFFECT: method improvement.

20 cl, 2 dwg

FIELD: chemistry.

SUBSTANCE: method of separating inert gases from gases containing argon, xenon, krypton, nitrogen and hydrogen includes cooling a starting gas stream, cooling and separating via two-step fractionation to obtain liquid separation products: argon, krypton-xenon mixture, and gaseous separation products: nitrogen and a nitrogen-hydrogen mixture. The first fractionation step includes preliminary separation to obtain a reflux. The reflux obtained at the first fractionation step is used for refluxing at the second fractionation step. Before fractionation at the second step, a large portion of the gas stream after cooling undergoes preliminary separation into a gaseous fraction, which is condensed and separated, and a liquid fraction - a reflux, which is returned to the first fractionation step and then fed for supercooling before use for refluxing at the second fractionation step. The smaller portion of the gas stream is compressed before cooling. The smaller portion of the gas stream is cooled in three steps and said portion is filtered between the second and third cooling steps.

EFFECT: reduced harmful emissions and enabling extraction of inert gases from tail gases with maximum output of argon.

10 cl, 1 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to a method of removing a fraction with high nitrogen content from a starting fraction primarily containing nitrogen and hydrocarbons. The starting fraction is partially condensed and divided by fractionation into a fraction with high nitrogen content and a fraction with high methane content. According to the invention, during cut-off of the supply of the starting fraction being fed for fractionation, the separation column(s) (T1/T2) and heat exchangers (E2) serving for partial condensation (E1) of the starting fraction and cooling and heating process streams formed during fractionation are kept, through one or more different coolants (6-11), at temperature levels substantially corresponding to temperature levels during the normal operating mode of the separation column(s) T1/T2) and heat exchangers (E1, E2).

EFFECT: improved method.

2 cl, 4 dwg

FIELD: chemistry.

SUBSTANCE: method of producing a multicomponent solution of a krypton-xenon mixture and a special purity solvent involves feeding a multicomponent solution into a precursor solution line, preliminary physical-chemical purification from explosive and hardening impurities, cooling and fractional separation in columns. Said columns are equipped with samplers in the concentration part or blow line and the vapour zone of the bottom. A krypton-xenon mixture containing volatile impurities and a stream of a solvent containing volatile impurities are obtained in the column for obtaining a krypton-xenon mixture. The method also includes purifying the stream of the solvent fraction in a column for obtaining special purity solvent from volatile impurities to obtain a special purity solvent. All impurities that are volatile relative to krypton are removed with the stream of the solvent fraction, wherein the part of said impurities which is semi-volatile relative to the solvent is removed in a column for purification from intermediate impurities. An apparatus for carrying out said method is described.

EFFECT: invention reduces content of impurities in a krypton-xenon mixture, simplifies and reduces the cost of processing said mixture.

3 cl, 1 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to method of removal of fractions with high content of nitrogen from initial fraction containing, mainly, nitrogen and hydrocarbons. Note here that initial fraction is separated by rectification into high nitrogen fraction and high methane fraction. High-methane fraction is evaporated and overheated at maximum possible pressure to produce cold. High-nitrogen fraction is at least temporarily and/or partially contracted and fed to rectification as a backflow. In compliance with this invention, at least temporarily, at least partially one partial flow (16) of compressed (C) fraction (9') with high nitrogen content after performed condensation (E1) is expanded (f) in valve and, to produce cold, at least partially, preferably completely, is evaporated (E1).

EFFECT: uniform distribution of compressor load irrespective of nitrogen concentration in initial fraction.

7 cl, 2 dwg

FIELD: machine building.

SUBSTANCE: invention relates to a cyclone separator for fluid medium, comprising a neck part (4), which is placed between the section of inlet of the convergent fluid medium and the section of outlet of the divergent fluid medium. The cyclone separator for fluid medium is made with the capability to push the cyclone flow via the section of inlet of the convergent fluid medium and the neck part to the section of outlet of the divergent fluid medium in direction downstream the flow. The section of outlet of the divergent fluid medium comprises an inner primary outlet pipe (7) for fluid components depleted by condensing vapours and an outer secondary outlet pipe (6) for fluid components enriched with condensing vapours. The cyclone separator for fluid medium comprises an additional outer secondary outlet pipe (16). The outer secondary outlet pipe (6) is placed in the first position along the central axis (I) of the cyclone separator for fluid medium, and the additional outer secondary outlet pipe (16) is placed in the second position along the central axis (I) of the cyclone separator for fluid medium.

EFFECT: higher efficiency of a separator and purity of produced fractions.

27 cl

FIELD: power engineering.

SUBSTANCE: invention relates to the method of liquefaction of natural gas in a plant comprising two cooling circuits, where natural gas is cooled by means of heat exchange with the first cooling mixture, in the first cooling circuit. For this purpose they compress the first cooling mix MR1; the compressed first cooling mix is condensed; natural gas and compressed and condensed first cooling mix are supercooled by means of heat exchange with the first expanded fraction; the supercooled first cooling mix is divided into the first and second fractions, the first fraction is expanded to the first pressure level; natural gas and second fraction are cooled by means of heat exchange with the second fraction, expanded to the second pressure level. Then the specified natural gas is liquefied by means of heat exchange with the second cooling mix, in the second cooling circuit. For this purpose they compress the specified second cooling mix MR2; the second compressed cooling mix is condensed; the compressed and condensed second mix is cooled by means of heat exchange with the first fraction and the second fraction; the second cooling mix is expanded to the third pressure level; natural gas is cooled with the expanded second cooling mix to produce liquefied natural gas. In the method the first and second cooling mixes contain one saturated hydrocarbon and ethylene.

EFFECT: invention makes it possible to simplify a plant, and also to produce best thermal efficiency of the method.

6 cl, 5 dwg

FIELD: chemistry.

SUBSTANCE: group of inventions relates to a method and an installation for the purification of a multi-phase hydrocarbon flow. The multi-phase hydrocarbon flow is purified with obtaining a purified liquid hydrocarbon flow, such as a flow of liquefied natural gas. The multi-phase hydrocarbon flow is supplied into the first gas-liquid separator, in which the said flow is divided under the first pressure into a hydrocarbon vapour flow of the first separator and the lower flow of the first separator. The lower flow of the first separator is then divided in the second gas-liquid separator under the second pressure, which is lower than the first pressure, with the formation of a hydrocarbon vapour flow of the second separator and a purified hydrocarbon flow. The hydrocarbon vapour flow of the second separator is subjected to compression in a compressor for the upper flow, which results in obtaining a stripping vapour flow, which is supplied into the first gas-liquid separator.

EFFECT: group of inventions is aimed at the creation of the method and installation for obtaining the purified liquid hydrocarbon flow, which does not require the application of cold in the upper gaseous flow for the creation of an irrigation flow.

17 cl, 2 dwg, 1 tbl

FIELD: oil and gas industry.

SUBSTANCE: invention is referred to the method for liquefaction of fraction enriched with hydrocarbons. According to the method cooling and liquefaction of the fraction enriched with hydrocarbons is made by indirect heat exchange with refrigerant mixture in the refrigerant mixture circulating loop. The refrigerant mixture is compressed in two stages, and upon each stage it is separated into gaseous and liquid fractions. Gaseous fraction of the last compression stage is cooled up to the lowest temperature level while liquid fraction of one of intermediate compression stages is cooled up to the temperature level higher than the lowest temperature level. Liquid fraction cooled up to the temperature level higher than the lowest temperature level is cooled by indirect heat exchange with burnt fraction enriched with hydrocarbons. At that the above cooling of liquid fraction cooled up to the higher temperature level takes place by indirect heat exchange with boiling fractions or one boiling fraction that occurs since the stage of separation into gaseous and liquid fraction following the subsequent compression stage.

EFFECT: invention is aimed to prevention of undesired formation of two-phase flow and drawbacks related to it.

6 cl, 2 dwg

FIELD: oil-and-gas industry.

SUBSTANCE: inventions group relates to the method and device generating the cooled hydrocarbons flow. Method uses cooling, at least at two consequential pressure levels. At that in first flow and first flow of mixed refrigerant parts of the first mixed refrigerant in first and second heat exchangers; first and second expansion devices; and first compressor are used to generate flow of first mixed refrigerant. The cooling method is controlled using the improved process controller based on the predictive control model to determine simultaneous control effects for set of the manipulated variables to optimise of at least one set of parameters, during control of at least one set of controlled variables. Set of the manipulated variables includes: composition of first mixed refrigerant; setup of first expansion device and setup of second expansion device.

EFFECT: inventions group ensures optimal control under various pressures of secondary multicomponent refrigerant.

18 cl, 2 dwg

FIELD: chemistry.

SUBSTANCE: described is method of liquidising fraction with high content of hydrocarbons with simultaneous removal of fraction with high C2+ content with cooling and fraction liquefying taking place with indirect heat-exchange by means of mixture of refrigerants of circulation circuit of refrigerant mixture, in which mixture of refrigerants is subjected to at least two-step compression, and separation of fraction with high C2+ content taking place at regulated temperature level, with mixture of refrigerants being separated into gaseous and liquid fractions, both fractions are overcooled, expand, in fact, to pressure of absorption of first stage of compressor and are at least partly evaporated. In accordance with invention at least one partial flow (19, 24) of liquefied, first of all gaseous fraction of refrigerant mixture (15) is expanded (j, h) and admixed to expanded liquid fraction of refrigerant mixture (22).

EFFECT: invention is aimed at creation of reliable method of liquefying fraction with high content of hydrocarbons and at provision of effective and controlled removal of ethane and higher hydrocarbons in the course of natural gas liquefying.

6 cl, 2 dwg

FIELD: heating.

SUBSTANCE: group of inventions relates to a method of cooling a flow of gaseous hydrocarbons. The gaseous hydrocarbon flow is cooled to obtain a liquefied hydrocarbon flow. The gaseous hydrocarbon flow is cooled in one or more heat exchangers using a first refrigerant of the circulation circuit of first refrigerant, in which the said first refrigerant is compressed in the first compressor driven by the first gas turbine engine that is provided by the first inlet air flow, and liquefied using the circuit of second refrigerant, in which the second refrigerant is compressed in the second compressor driven by the second gas turbine engine, which is provided by the second flow of inlet air. The located cooling capacity of the flow of the cooled refrigerant is separated into a first part and a second part in accordance with the typical input parameter. The located cooling capacity of the first part is used for cooling the first flow of the inlet air, as the located cooling capacity of the second part of the flow is used to cool the second flow of the inlet air. The device for cooling a gaseous flow of hydrocarbons is described.

EFFECT: group of inventions is aimed at improving the reliability of the unit for cooling flow of gaseous hydrocarbons.

14 cl, 5 dwg

FIELD: chemistry.

SUBSTANCE: in method and device for cooling hydrocarbon flow cooled hydrocarbon flow (45) is subjected to heat exchange in first heat exchanger (50) with at least one flow of coolant (145b, 185b), characterised by rate (FR1) of first flow of coolant, which results in formation of cooled hydrocarbon flow (55), characterised by rate (FR2) of cooled hydrocarbon flow, and at least one return flow (105) of coolant. rate (FR1) of first coolant flow and rate (FR2) of flow of cooled hydrocarbon agent is regulated until first specified parameter (SP1) for rate (FR1) of first coolant flow is achieved. If first specified parameter (SP1) is larger than rate (FR1) of coolant flow, rate (FR2) of hydrocarbon flow is increased before increasing rate (FR1) of coolant flow, if first specified parameter (SP1) is lower than rate of coolant flow, rate (FR1) of coolant flow is reduced before reduction of rate (FR2) of hydrocarbon flow, and if rate (FR2) of hydrocarbon flow decreases, rate (FR1) of coolant flow is reduces.

EFFECT: prevention of heat exchanger overcooling.

15 cl, 3 dwg

FIELD: machine building.

SUBSTANCE: invention describes a liquefied natural gas plant that uses a removal system of non-condensed material from one or more cooling cycles within the plant and its operation method. The method involves cooling of natural gas flow in the first closed cooling cycle and in an open cooling cycle so that additionally cooled natural gas flow is obtained. Non-condensed material is separated from at least some part of cooled natural gas flow in the first separating capacity so that mainly bottom liquid fraction depleted with non-condensed components and mainly top steam fraction enriched with non-condensed components are obtained. Top steam fraction enriched with non-condensed components is supplied to a fuel gas system to be used as fuel gas. Bottom liquid fraction is returned mainly to a methane cooling agent of the open cooling cycle.

EFFECT: use of the invention will allow stabilising operation of the plant in case of abrupt changes in concentration of the incoming natural gas flow supplied to the plant.

27 cl, 3 dwg

FIELD: machine building.

SUBSTANCE: natural gas liquefaction method, as per which natural gas is cooled, condensed and supercooled as a result of indirect heat exchange with two cooling mixtures circulating in circuits. The first cooling mixture is compressed, cooled and condensed at least partially by heat exchange with external environment (water, air). The first cooling mixture is supercooled as a result of heat exchange so that the first cooling mixture is in liquid phase so that good distribution of cooling mixture can be provided in a series of heat exchangers. Then, the cooling mixture is supercooled in the first heat exchanger by heat exchange with some part of the cooling mixture; with that, the above part is throttled prior to heat exchange. Natural gas is cooled in the second heat exchanger, and at the same time, the second cooling mixture is cooled by heat exchange with the supercooled cooling mixture; with that, the first heat exchanger differs from the second heat exchanger. Then, natural gas is liquefied and supercooled by heat exchange with the second cooling mixture till liquid natural gas is obtained.

EFFECT: use of the invention will allow improving efficiency at lower CO2 emissions.

5 cl, 3 dwg

FIELD: heating.

SUBSTANCE: supplied gas is liquefied using a closed refrigerating system in which flow (150) of cooled compressed gaseous cooling agent expands (136) to provide the first flow (154) of expanded gaseous cooling agent that is actually vapour and is used for cooling and liquefaction of flow (100) of supplied gas by means of indirect heat exchange (110). Flow (102) of supplied liquefied gas is preferably supercooled by indirect heat exchange (112) with the second flow (172) of expanded gaseous cooling agent that is actually vapour too and can be represented with flow (170) of cooled compressed gaseous cooling agent or some part of the first flow (152) of expanded gaseous cooling agent. Cooling capacity for flow (146) of compressed gaseous cooling agent is provided by part (16) of the first flow (152) of expanded gaseous cooling agent; with that, gaseous cooling agent (156) is partially heated by means of the above heat exchange (11) with supplied gas and/or the second flow (174) of expanded gaseous cooling agent, which is heated by means of the above supercooling (112).

EFFECT: improving safety and reliability.

15 cl, 13 dwg

Compression device // 2246078

FIELD: applicable for compression of gaseous refrigerant for use in the cooling system of the liquefaction plant.

SUBSTANCE: the cooling system has an inlet, first outlet for refrigerant at low pressure, second outlet for refrigerant at intermediate pressure, third outlet for refrigerant at high pressure, and the fourth outlet for refrigerant at a pressure exceeding the high pressure. The device has the first and second compressors. The first compressor includes the main inlet connected to the first outlet, side inlet connected to the third outlet, and the outlet connected to the inlet of the cooling system. The second compressor includes the main inlet connected to the second outlet, side inlet connected to the fourth outlet, and the outlet connected to the inlet of the cooling system.

EFFECT: enhanced efficiency.

2 cl, 2 dwg

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