Methods, apparatuses and systems for processing fluid streams having multiple constituents

Abstract

Methods, apparatuses and systems for processing fluid streams having multiple constituents are provided including embodiments utilizing ascending temperature separation processes as well as combined ascending and descending temperature separation processes. For example, in one embodiment, a mixed gas stream may be processed by flowing the stream through multiple heat exchangers, expanding the stream, and then separating the stream into a liquid portion and a vapor portion. The vapor portion, having an increased or decreased concentration of an identified constituent may then pass through the heat exchangers again in reverse order and collected. The liquid portion may then be subjected to further, sequential separation acts which each take place at increasing temperatures. In another embodiment, numerous, sequential separation acts take place in, for example, at decreasing temperatures and, subsequently, at increasing temperatures. Such a mixed fluid stream, for example, may include constituents such as hydrogen, carbon monoxide and methane.

1 . A method of processing a mixed gas stream having multiple constituents, the method comprising:
 flowing the mixed gas stream through a plurality of heat exchangers to cool the mixed gas stream;   expanding the cooled mixed gas stream;   separating the expanded mixed gas stream into a vapor portion and a liquid portion;   flowing the vapor portion through at least some of the plurality of heat exchangers to assist in cooling the mixed gas stream; and   flowing the liquid portion through the plurality of heat exchangers and subjecting the liquid portion to a plurality of liquid-vapor separation processes, wherein the first liquid-vapor separation process is conducted after flowing the liquid portion through at least one heat exchanger and wherein each subsequent liquid-vapor separation process takes place at a temperature warmer than a previous liquid-vapor separation process.   
   
   
       2 . The method according to  claim 1 , further comprising collecting the vapor portion as a first component stream having an increased level of at least one selected constituent of the multiple constituents of the mixed gas stream as compared to the mixed gas stream. 
   
   
       3 . The method according to  claim 2 , further comprising producing at least a second component stream from the liquid portion, the at least a second component stream having an increased level of at least one selected constituent of the multiple constituents of the mixed gas stream as compared to the mixed gas stream. 
   
   
       4 . The method according to  claim 3 , further comprising providing the mixed gas stream with a composition comprising methane, hydrogen and carbon monoxide and wherein separating the expanded mixed gas stream into a vapor portion and a liquid portion includes separating the vapor portion with an increased concentration of carbon monoxide as compared to the mixed gas stream. 
   
   
       5 . The method according to  claim 4 , wherein producing at least a second component stream further includes producing a stream with an increased concentration of methane. 
   
   
       6 . The method according to  claim 5 , further comprising providing the mixed gas stream at a pressure of approximately 280 pounds per square inch absolute (psia) or greater. 
   
   
       7 . The method according to  claim 6 , wherein expanding the at least a portion of the mixed gas stream includes expanding the at least a portion of the mixed gas stream to a pressure of approximately 15 psia. 
   
   
       8 . A gas processing plant comprising:
 a plurality of heat exchangers;   a first flow path configured to convey a fluid stream sequentially through each of the plurality of heat exchangers;   an expansion device disposed in the first flow path downstream of the plurality of heat exchangers;   a first separation tank coupled with the first flow path downstream of the expansion device;   a second flow path configured to convey a vapor stream through the plurality of heat exchangers in a reverse sequential order as compared to the first flow path; and   a plurality of additional separation tanks, each of the plurality of separation tanks being disposed between, and in communication with, two different heat exchangers of the plurality of heat exchangers, the plurality of additional separation tanks and the plurality of heat exchangers being located and configured to flow fluid through the plurality of additional separation tanks while increasing the temperature of any fluid flowing therethrough as such fluid progresses from one separation tank of the plurality to another.   
   
   
       9 . The gas processing plant of  claim 8 , further comprising a third flow path configured to convey a liquid stream through the plurality of heat exchangers and the plurality of additional separation tanks in an alternating manner. 
   
   
       10 . The gas processing plant of  claim 9 , further comprising at least one additional flow path configured to convey at least one vapor stream from at least one of the plurality of additional separation tanks through one or more of the plurality of heat exchangers. 
   
   
       11 . The gas processing plant of  claim 9 , further comprising at least a fourth flow path and a fifth flow path, each of the fourth and the fifth flow paths being configured to convey a vapor stream from different ones of the plurality of additional separation tanks to a mixing valve. 
   
   
       12 . The gas processing plant of  claim 10 , further comprising a sixth flow path configured to convey a combined vapor stream from the mixing valve through at least one of the plurality of heat exchangers. 
   
   
       13 . The gas processing plant of  claim 11 , wherein the plurality of heat exchangers includes at least four heat exchangers and wherein the plurality of additional separation tanks includes at least two additional separation tanks. 
   
   
       14 . A method of processing a mixed gas stream having multiple constituents, the method comprising:
 subjecting at least a portion of the mixed gas stream to a first plurality of sequentially conducted gas-liquid separation acts, wherein each of the first plurality of sequentially conducted gas-liquid separation acts is conducted at a reduced temperature as compared to a previously conducted gas-liquid separation act of the first plurality;   expanding the at least a portion of the mixed gas stream and further separating the expanded stream into a liquid portion and a vapor portion; and   subjecting at least a portion of the liquid portion to an additional plurality of sequentially conducted gas-liquid separation acts, wherein each of the additional plurality of sequentially conducted gas-liquid separation acts is conducted at an increased temperature as compared to a previously conducted gas-liquid separation act of the additional plurality of sequentially conducted gas-liquid separation acts of the additional plurality.   
   
   
       15 . The method according to  claim 14 , further comprising:
 expanding an additional liquid portion produced from at least one of the first plurality of gas-liquid separation acts; and   combining the expanded additional liquid portion with the at least a portion of the mixed gas stream subsequent further expanding the at least a portion of the mixed gas stream and prior to further separating the expanded stream into a liquid portion and a vapor portion.   
   
   
       16 . The method according to  claim 15 , further comprising:
 expanding another liquid portion produced from at least one of the first plurality of gas-liquid separation acts; and   combining the liquid portion with the expanded another liquid portion prior to subjecting at least a portion of the liquid portion to an additional plurality of sequentially conducted gas-liquid separation acts.   
   
   
       17 . The method according to  claim 14 , wherein subjecting at least a portion of the mixed gas stream to a first plurality of sequentially conducted gas-liquid separation acts further includes flowing the at least a portion of the mixed gas stream through an alternating configuration of a plurality of heat exchangers and a first plurality of separation tanks. 
   
   
       18 . The method according to  claim 17 , wherein subjecting at least a portion of the liquid portion to an additional plurality of sequentially conducted gas-liquid separation acts further includes flowing the at least a portion of the liquid portion through an alternating configuration of the plurality of heat exchangers and another plurality of separation tanks. 
   
   
       19 . The method according to  claim 14 , further comprising providing the mixed gas stream with a composition comprising methane, ethane, propane, hydrogen and carbon monoxide. 
   
   
       20 . The method according to  claim 19 , further comprising providing the mixed gas stream at a pressure of approximately 280 pounds per square inch absolute (psia) or greater. 
   
   
       21 . The method according to  claim 20 , wherein expanding the at least a portion of the mixed gas stream includes expanding the at least a portion of the mixed gas stream to a pressure of approximately 15 psia. 
   
   
       22 . A gas processing plant comprising:
 a plurality of heat exchangers;   a first plurality of separation tanks, each of the first plurality of separation tanks having at least one inlet in communication with one of the plurality of heat exchangers and at least one outlet in communication with another of the plurality of heat exchangers;   a second plurality of separation tanks, each of the second plurality of separation tanks having at least one inlet in communication with one of the plurality of heat exchangers and at least one outlet in communication with another of the plurality of heat exchangers;   a first flow path configured to convey a fluid stream through each of the plurality of heat exchangers and through the first plurality of separation tanks such that any fluid flowing therethrough enters each separation tank of the first plurality of separation tanks at a reduced temperature as compared to any upstream separation tank of the first plurality of separation tanks;   an expansion device disposed in the first flow path downstream of the plurality of heat exchangers;   an additional separation tank coupled with the first flow path downstream of the expansion device; and   a second flow path configured to convey a fluid stream through the plurality of heat exchangers and the second plurality of separation tanks such that any fluid flowing therethrough enters each separation tank of the second plurality of separation tanks at an increased temperature as compared to any upstream separation tank of the second plurality of separation tanks.   
   
   
       22 . The gas processing plant of  claim 21 , further comprising a third flow path configured to convey a fluid stream through plurality of heat exchangers. 
   
   
       24 . The gas processing plant of claim  23 , further comprising a fourth flow path configured to flow fluid from one of the first plurality of separation tanks to one of the second plurality of separation tanks. 
   
   
       25 . The gas processing plant of  claim 24 , further comprising another expansion device disposed in the fourth flow path.