Method for Recycling Streams in a Separations Process

Abstract

A method and apparatus for recycling streams in a separations process comprising: determining a measured reading of a parameter of the separations processor is in a suboptimal range; separating, via a separation unit having a volume of contact fluid, the inert gas from the pollutant gas in the inlet flue gas stream to form a clean gas stream and a purified pollutant gas stream; removing at least 1% of the volume of contact fluid to form a removed volume of contact liquid; performing some unit operations on the removed volume of contact fluid; injecting the clean gas stream into the inlet flue gas stream to form a flue gas stream of lower pollutant concentration; and, repeating at progressively lower pollutant concentration, as the inlet stream until the processor determines that a measured reading of the parameter has been returned to a substantially optimal range.

1 . A method for recycling streams in a separations process, comprising:
 providing a processor communicatively coupled to a non-transitory storage medium, the non-transitory storage medium comprising data storage, the data storage comprising instructions;   determining, via the processor, that a measured reading of a parameter of the separations processor is in a suboptimal range;   providing an inlet flue gas stream comprising an inert gas and a pollutant gas;   separating, via a separation unit comprising a volume of contact fluid selected from the group consisting of aliphatic hydrocarbons with substituted halogens, aliphatic hydrocarbons without substituted halogens, aromatic hydrocarbons with substituted halogens, aromatic hydrocarbons without substituted halogens, cyclic hydrocarbons with substituted halogens, cyclic hydrocarbons without substituted halogens, and combinations thereof, the inert gas from the pollutant gas in the inlet flue gas stream to form a clean gas stream and a purified pollutant gas stream;   removing at least 1% of the volume of contact fluid to form a removed volume of contact liquid;   performing at least one unit operation on the removed volume of contact fluid, the at least one unit operation selected from a group consisting of increasing the temperature of the removed volume of the content fluid by at least 2 degrees Celsius, decreasing the temperature of the removed volume of the content fluid by at least 2 degrees Celsius, vaporizing at least 5% of the removed volume of the content fluid, removing at least 1 of an amount of impurities disposed in the removed volume of the content fluid, distilling at least 50% of the removed volume of the content liquid, and combinations thereof;   injecting the clean gas stream into the inlet flue gas stream to form a flue gas stream of lower pollutant concentration;   performing at least one other operation on the purified pollutant gas stream; and   repeating the preceding steps of the method using the flue gas stream, at progressively lower pollutant concentration, as the inlet stream until the processor determines that a measured reading of the parameter has been returned to a substantially optimal range or the processor receives a communication informing the processor that the measured reading of the parameter has been returned to a substantially optimal range, or separation process has improved or the processor receives a notification that the separation unit can return to a full load.   
     
     
         2 . The method as in  claim 1 , wherein the separation unit uses a cryogenic carbon capture process and condenses the pollutant gas; the contact fluid consists of isopentane. 
     
     
         3 . The method as in  claim 2 , wherein the separation unit can return to a full pollutant load when its temperature drops below a set operational temperature. 
     
     
         4 . The method as in  claim 1 , wherein a measured pollutant load value for the process is decreased to a lesser measured pollutant load value by decreasing the load for the process, to correct for the measured reading of the parameter of the separations processor that is in a suboptimal range, the method further comprising the step of increasing the load for the process to substantially normal levels after the processor has received a communication that the measured reading of the parameter of the separations processor that previously was in a suboptimal range has been restored to a measured reading of the parameter substantially falling within an optimal range. 
     
     
         5 . The method as in  claim 1 , wherein the purified pollutant stream is also recycled and reinjected into the inlet flue gas stream. 
     
     
         6 . The method as in  claim 1 , additionally comprising:
 injecting a contact fluid as a vapor into the inlet flue gas stream;   separating the contact fluid from the purified pollutant gas stream to form a contact fluid stream;   performing other desired unit operations on the contact fluid stream; and   reinjecting the contact fluid stream into the inlet flue gas stream.   
     
     
         7 . The method as in  claim 6 , wherein the contact fluid is injected as a liquid into the separation unit. 
     
     
         8 . The method as in  claim 6 , wherein the contact fluid is selected from the group consisting of aliphatic fluids, aromatic fluids, cyclic hydrocarbons with substituted halogens, and cyclic hydrocarbons without substituted halogens. 
     
     
         9 . The method as in  claim 1 , wherein the inert gas is selected from the group consisting of nitrogen, oxygen, water, air, and combinations thereof. 
     
     
         10 . The method as in  claim 1 , wherein the pollutant gas is selected from the group consisting of carbon dioxide, sulfur oxides, nitrogen oxides, fly ash, mercury, arsenic, other pollutants present in flue gas, and combinations thereof. 
     
     
         11 . An apparatus for recycling streams in a separations process; comprising:
 an inlet flue gas stream, comprising a quantity of inert gas and a quantity of pollutant gas;   a contact fluid injected as a vapor into the inlet flue gas stream;   a separation unit configured to separate the inert gas from the pollutant and the contact fluid in the inlet stream to form a clean gas stream, a mixed stream;   a second separation unit configured to separate the contact fluid from the pollutant gas in the mixed stream to form a purified pollutant stream and a contact fluid stream;   an injection point where the contact fluid stream may be reinjected into the flue gas stream; and   an injection point where the clean gas stream may be reinjected into the inlet flue gas stream to form a flue gas stream of lower pollutant concentration.   
     
     
         12 . The apparatus as in  claim 11 , wherein the contact fluid is injected as a liquid into the separation unit. 
     
     
         13 . The apparatus as in  claim 11 , wherein the contact fluid is selected from the group consisting of aliphatic fluids, aromatic fluids, cyclic hydrocarbons with substituted halogens, and cyclic hydrocarbons without substituted halogens. 
     
     
         14 . The apparatus as in  claim 11 , wherein the inert gas is selected from the group consisting of nitrogen, oxygen, water, air, and combinations thereof. 
     
     
         15 . The apparatus as in  claim 11 , wherein the pollutant gas is selected from the group consisting of carbon dioxide, sulfur oxides, nitrogen oxides, fly ash, mercury, arsenic, other pollutants present in flue gas, and combinations thereof. 
     
     
         16 . The apparatus as in  claim 11 , wherein the clean gas stream is recycled until the separation unit drops below a set operational temperature. 
     
     
         17 . The apparatus as in  claim 11 , wherein the purified pollutant stream is also recycled and reinjected into the flue gas stream. 
     
     
         18 . An apparatus for recycling streams in a separations process, comprising:
 an inlet flue gas stream, comprising a quantity of inert gas and a quantity of pollutant gas;   a contact fluid injected as a vapor into the inlet flue gas stream or as a liquid into the separation unit;   a separation unit configured to separate the inert gas from the pollutant and the contact fluid in the inlet stream to form a clean gas stream and a mixed stream;   a second separation unit configured to separate the contact fluid from the pollutant gas in the mixed stream to form a purified pollutant stream and a contact fluid stream;   a number of additional unit operations through which the purified pollutant stream or the contact fluid stream may pass;   an injection point where the contact fluid stream may be reinjected into the flue gas stream; and   an injection point where the clean gas stream may be reinjected into the inlet flue gas stream to form a flue gas stream of lower pollutant concentration.   
     
     
         19 . The apparatus as in  claim 18 , wherein the flue gas stream comprises carbon dioxide and nitrogen, and the contact fluid is isopentane. 
     
     
         20 . The apparatus as in  claim 19 , wherein the flue gas stream is simulated, additionally comprising:
 bottled nitrogen to be injected into a closed loop system;   bottled carbon dioxide to be injected into the closed loop system;   a solenoid valve through which the injected bottled nitrogen is regulated;   a pressure transducer communicatively coupled to the solenoid valve, configured to control the solenoid valve to maintain a constant set pressure;   the pressure transducer placed on the suction side of a blower;   a flowmeter placed after the blower;   the flowmeter communicatively coupled to the blower to maintain a constant flow rate;   a separation unit configured to separate the carbon dioxide from the nitrogen in the closed loop system;   an inlet stream of nitrogen and carbon dioxide flowing into the separation unit, a first outlet stream of cleaned nitrogen, and a second outlet stream of purified carbon dioxide emerging from the separation unit;   a first analyzer configured to monitor the concentration of carbon dioxide in the inlet stream entering the separation unit;   a second analyzer through which the cleaned nitrogen stream passes, the second analyzer configured to measure the concentration of carbon dioxide in the cleaned nitrogen stream;   a combination point where the purified carbon dioxide stream and the carbon dioxide supply are injected into the cleaned nitrogen stream;   the solenoid valve placed after the combination point;   a first mass flow controller communicatively coupled to the first and second analyzers, the first mass flow controller configured to regulate the injection rate of the bottled carbon dioxide;   a second mass flow controller configured to monitor the flow rate of the purified carbon dioxide stream and enable feed-forward control over the first mass flow controller; and   a third mass flow controller communicatively coupled to the second mass flow controller, configured to release excess carbon dioxide.