Patent Publication Number: US-2019168175-A1

Title: Solids-Producing Siphoning Exchanger

Description:
GOVERNMENT INTEREST STATEMENT 
     This invention was made with government support under DE-FE0028697 awarded by the Department of Energy. The government has certain rights in the invention. 
    
    
     FIELD OF THE INVENTION 
     The devices and processes described herein relate generally to siphoning. More particularly, the devices and processes described herein relate to devices, systems, and methods for using siphoning for direct contact heat exchange. 
     BACKGROUND 
     Separations of components out of fluids is a fundamental part of many industries. Gas-vapor, gas-liquid, and other fluid-fluid extractions can be taxing as they often require large volumes and complex mechanisms to maximize contact between fluids, maximizing fluid exchange rates. Devices, systems, and methods for extracting components from fluids without these difficulties would be beneficial. 
     SUMMARY 
     Devices, systems, and methods for siphoning heat exchange or reaction for solids production are disclosed. Passing a contact fluid through a siphoning device, wherein the siphoning device is made of a contact fluid inlet, a carrier fluid inlet, and an outlet, and wherein the contact fluid passes through the contact fluid inlet, inducing a siphon in the carrier fluid inlet. This siphon then siphons a carrier fluid through the carrier fluid inlet and into the contact fluid. The carrier fluid is, in part, made of a first component. The carrier fluid and the contact fluid mix. This mixing produces a product solid, wherein the product solid is produced from the first component by desublimation, condensation, solidification, crystallization, precipitation, reaction with the contact fluid, or a combination thereof of at least a portion of the first component. The product solid passes through the outlet. 
     The process may produce a warm contact fluid and a component-depleted carrier fluid, wherein the warm contact fluid is produced by the carrier fluid transferring heat to the contact fluid, and wherein the component-depleted carrier fluid is produced when the first component is removed, at least in part, from the carrier fluid. 
     The outlet may be a converging/diverging nozzle. The converging-diverging nozzle may have a variable-diameter throat. 
     The outlet may split into a gas outlet and a liquid outlet. The warm contact liquid and the product solid may pass out the liquid outlet and the product-depleted carrier gas may pass out the gas outlet. 
     The product solid, the warm contact liquid, and the product-depleted carrier gas may be channeled into a liquid-gas separator which separates the product-depleted carrier gas from the product solid and the warm contact liquid. The product solid and the warm contact liquid may then pass through a solid-liquid separator which separates the product solid from the warm contact liquid. The solid-liquid separator may be a filtering screw press. The liquid-gas separator may include vortex chamber walls. The vortex chamber walls may be made of mesh, membranes, or a combination thereof. 
     The outlet may be a diverging/converging nozzle. 
     The eductor may have a plurality of siphon ports. 
     The eductor may be made of diamond, metal, plastic, ceramic, or a combination thereof. 
     The process may include recycling a portion of the product solid to the contact fluid inlet. 
     The contact fluid may include water, hydrocarbons, liquid ammonia, liquid carbon dioxide, cryogenic liquids, high-temperature liquids, or a combination thereof. The hydrocarbons may include 1,1,3-trimethylcyclopentane, 1,4-pentadiene, 1,5-hexadiene, 1-butene, 1-methyl-1-ethylcyclopentane, 1-pentene, 2,3,3,3-tetrafluoropropene, 2,3-dimethyl-1-butene, 2-chloro-1,1,1,2-tetrafluoroethane, 2-methylpentane, 3-methyl-1,4-pentadiene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-methylpentane, 4-methyl-1-hexene, 4-methyl-1-pentene, 4-methylcyclopentene, 4-methyl-trans-2-pentene, bromochlorodifluoromethane, bromodifluoromethane, bromotrifluoroethylene, chlorotrifluoroethylene, cis 2-hexene, cis-1,3-pentadiene, cis-2-hexene, cis-2-pentene, dichlorodifluoromethane, difluoromethyl ether, trifluoromethyl ether, dimethyl ether, ethyl fluoride, ethyl mercaptan, hexafluoropropylene, isobutane, isobutene, isobutyl mercaptan, isopentane, isoprene, methyl isopropyl ether, methylcyclohexane, methylcyclopentane, methyl cyclopropane, n,n-diethylmethylamine, octafluoropropane, pentafluoroethyl trifluorovinyl ether, propane, sec-butyl mercaptan, trans-2-pentene, trifluoromethyl trifluorovinyl ether, vinyl chloride, bromotrifluoromethane, chlorodifluoromethane, dimethyl silane, ketene, methyl silane, perchloryl fluoride, propylene, vinyl fluoride, or a combination thereof. 
     The carrier gas may include flue gas, syngas, producer gas, natural gas, steam reforming gas, hydrocarbons, light gases, refinery off-gases, organic solvents, steam, ammonia, or a combination thereof. 
     The siphon nozzle may include an aerator. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through use of the accompanying drawings, in which: 
         FIG. 1  shows a cutaway side view of an eductor. 
         FIG. 2  shows a cutaway side view of an eductor attached to a solid-liquid separator. 
         FIG. 3  shows an isometric side-back elevation view of an eductor. 
         FIG. 4  shows a method for removing a vapor from a gas. 
         FIG. 5  shows a method for separating the product fluids from  FIG. 4 . 
         FIG. 6  shows a process flow diagram for removing a vapor from a gas. 
     
    
    
     DETAILED DESCRIPTION 
     It will be readily understood that the components of the described devices, systems, and methods, as generally described and illustrated in the Figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the described devices, systems, and methods, as represented in the Figures, is not intended to limit the scope of the described devices, systems, and methods, as claimed, but is merely representative of certain examples of presently contemplated embodiments in accordance with the described devices, systems, and methods. 
     Removing components from a carrier fluid can be challenging. For example, when the gas phase component desublimates into a solid, separations switch from only a gas-liquid separation to include solid-liquid separations. In standard heat exchangers, this desublimation can cause fouling which leads to losses in efficiency. Devices, systems, and methods disclosed herein address these issues. Eductors can be used to produce solids from the components of the carrier fluid, either by direct-contact heat and material exchange, by reaction, or a combination thereof. Accordingly, desublimation, condensation, freezing, deposition, precipitation, or reaction of products can occur in the contact fluid, avoiding solid products collecting on equipment surfaces. Eductors are also able to use a liquid phase contact fluid to siphon a gas phase carrier fluid. This is advantageous since liquid pumps are more efficient than gas compressors. This lowers operational expenses for component separations versus traditional systems. 
     In this application, the term “eductor” is used to represent any eductors, ejectors, jet pumps, or other siphoning devices. Siphoning devices are any device that uses the flow of a first fluid to induce a siphon effect that draws a second fluid into the first fluid. Further, the term “fluid” is not limited to pure gases and pure liquids, nor is the term “liquid” limited to only pure liquids. Fluids can be any gas, liquid, or solid that flows. Slurries, where a liquid has entrained a solid, colloidal suspensions, where a liquid has suspended a solid, and gas streams that have entrained solids are all considered fluids, and all but the last is considered a liquid. The term “siphon port” refers to the inlet in which the carrier fluid enters the siphoning device. The terms, “carrier fluid inlet,” “carrier gas inlet,” and “carrier liquid inlet” are also siphon ports. 
     Referring now to the Figures,  FIG. 1  shows a cutaway side view  100  of an eductor  101  that may be used in the described devices, systems, and methods. The eductor  101  consists of a contact fluid inlet  120 , a contact fluid nozzle  106 , a mixing chamber  122 , a carrier fluid inlet  118 , a converging nozzle  108 , throat  110 , diverging nozzle  112 , and outlet  114 . In this example, contact fluid  102  may be isopentane and carrier fluid  104  may be combustion flue gas. The isopentane  102  is pumped through inlet  120  and passes through nozzle  106  into mixing chamber  122 . As the isopentane  102  flows through mixing chamber  122 , it creates a siphon, pulling the combustion flue gas  104  in through carrier fluid inlet  118  into mixing chamber  122 . In mixing chamber  122 , the combustion flue gas  104  comes into contact with the isopentane  102  where it is mixed and entrained into the isopentane  102 , resulting in at least a portion of the carbon dioxide in the combustion flue gas desublimating, producing a carbon dioxide slurry  116  and a carbon dioxide-depleted flue gas  126 . The carbon dioxide slurry  116  and depleted flue gas  126  pass into converging nozzle  108 , through throat  110 , through diverging nozzle  112 , and out outlet  114 . The converging and diverging nozzles  108  and  112  are used because the carbon dioxide slurry  116  and depleted flue gas  126  are compressible. The entrained depleted flue gas  126  makes the isopentane-based slurry compressible even at low Mach numbers. 
     In some embodiments, nozzle  106  may end with an aerator to allow better mixing of contact fluid  102  and carrier fluid  104 . In some embodiments, throat  110  may be a variable-diameter throat. 
     Referring now to  FIG. 2 ,  FIG. 2  shows a cutaway side view  200  of an eductor  201  that may be used in the described devices, systems, and methods. The eductor  201  consists of a contact fluid inlet  220 , a contact fluid nozzle  206 , a mixing chamber  222 , a carrier fluid inlet  218 , a nozzle  209 , and an outlet  214 . In this example, contact fluid  202  is a liquid and carrier fluid  204  is a gas. Contact fluid  202  is pumped through inlet  220  and passes through nozzle  206  into mixing chamber  222 . As contact fluid  202  flows through mixing chamber  222  it creates a siphon, pulling carrier fluid  204  in through carrier fluid inlet  218  into mixing chamber  222 . Carrier fluid  204  includes a vapor component. In mixing chamber  222 , carrier fluid  204  comes into contact with contact fluid  202  where it is mixed and entrained into the contact fluid  202 , resulting in at least a portion of the vapor component in the carrier fluid  204  desublimating, condensing, freezing, depositing, precipitating, reacting, or a combination thereof to become a product solid, thereby producing a slurry  216  and a vapor component-depleted carrier fluid  226 . The slurry  216  and depleted carrier fluid  226  passes through the nozzle  209 , the outlet  214 , and into a gas-liquid separator  224 . The vapor component-depleted carrier gas  226  is separated from the slurry  216  as it passes through the gas-liquid separator  224 . 
     In some embodiments, after the slurry  216  leaves the gas-liquid separator  224 , a portion of the slurry is recycled back into the contact liquid  202  to act as nucleation sites to assist in the formation of the product solid. 
     Referring now to  FIG. 3 ,  FIG. 3  shows an isometric side-back elevation view  300  of an eductor  301  that may be used in the described devices, systems, and methods. The eductor  301  consists of a contact fluid inlet  320 , a contact fluid nozzle  306 , a mixing chamber  322 , a plurality of carrier fluid inlet  318 , a nozzle  309 , and an outlet  314 . In this example, contact fluid  302  is a liquid and carrier fluid  304  is a gas. Contact fluid  302  is pumped through inlet  320  and passes through nozzle  306  into mixing chamber  322 . Carrier fluid  304  includes a vapor component. As contact fluid  302  flows through mixing chamber  322  it creates a siphon, pulling carrier fluid  304  in through the plurality of carrier fluid inlets  318  into mixing chamber  322 . In mixing chamber  322 , carrier fluid  304  comes into contact with contact fluid  302  where it is mixed and entrained into the contact fluid  302 , resulting in at least a portion of the carbon dioxide in the combustion flue gas desublimating, condensing, freezing, depositing, precipitating, reacting, or a combination thereof to become a product solid, thereby producing a slurry  316  and vapor component-depleted carrier fluid  226 . The slurry  316  passes through a nozzle  309 , an outlet  314 . 
     Referring now to  FIG. 4 , a method  400  for removing a vapor from a carrier gas is disclosed that may be used in the described devices, systems, and methods. At  401 , a contact liquid is passed through a siphoning device. The siphoning device includes a contact liquid inlet, a carrier gas inlet, and an outlet. At  402 , the contact liquid passes through the contact liquid inlet, inducing a siphon in carrier gas inlet. At  403 , the carrier gas is siphoned through the carrier gas inlet and into the contact liquid. The carrier gas includes a product vapor. At  404 , the carrier gas and the contact liquid are mixed. At  405 , the product vapor is desublimated, condensed, solidified, crystallized, precipitated, reacted with the contact fluid, or a combination thereof, producing a product solid, a warm contact liquid, and a product-depleted carrier gas. At  406 , the product solid, the warm contact liquid, and the product-depleted carrier gas are passed out of the siphoning device through an outlet. 
     Referring now to  FIG. 5 , a method  500  for separating the product fluids of method  400  is disclosed. At  406 , the product solid and the warm contact liquid passed out a liquid outlet. At  501 , the product-depleted carrier gas passes out a gas outlet. At  502 , the product solid and the warm contact liquid are passed into a solid-liquid separator. At  503 , the product solid and the warm contact liquid are separated in the solid-liquid separator. At  504 , the product solid passes out a solids outlet. At  505 , the warm carrier liquid passes out a liquid outlet. 
     Referring now to  FIG. 6 ,  FIG. 6  shows a process flow diagram  600  for removing a vapor from a carrier gas that may be used in the described devices, systems, and methods. A first-stage contact fluid  650  is passed into a first eductor  602 , siphoning first-stage carrier gas  674  into first eductor  602 . First-stage carrier gas  674  includes a vapor component. The fluids mix in first eductor  602  and produce a product solid from at least a portion of the vapor component, a warm first-stage contact fluid, and a stripped carrier gas  676 . Eductor  602  ends at a gas-liquid separator  614  which separates the stripped carrier gas  676  from a first-stage product slurry  652 . The first-stage product slurry  652  consists of warm first-stage contact fluid and the product solid. The first-stage product slurry  652  is cooled as it passes through heat exchanger  608 , forming a second-stage contact slurry  654 . The second-stage contact slurry  654  is then fed into the second eductor  604  as the second-stage contact fluid. The second-stage contact slurry  654  creates the siphon in the second eductor  604 , siphoning second-stage carrier gas  672  into second eductor  604 . Second-stage carrier gas  672  includes the vapor component in a larger quantity than the first-stage carrier gas  674 . Second-stage contact slurry  654  mixes with the second-stage carrier gas  672 , producing more product solid, a warm second-stage contact slurry, and the first-stage carrier gas  674 . Eductor  604  ends at a gas-liquid separator  616  which separates the first-stage carrier gas  674  from a second-stage product slurry  656 . The second-stage product slurry  656  consists of the warm second-stage contact slurry and the additional product solid. The second-stage contact slurry  656  is cooled as it passes through heat exchanger  610 , forming a third-stage contact slurry  658 . The third-stage contact slurry is then fed into the third eductor  606  as the contact fluid. The third-stage contact slurry  658  creates the siphon in the third eductor  606 , siphoning the carrier gas  670  into third eductor  606 . The carrier gas  670  includes the vapor component in a larger quantity than the second-stage carrier gas  672 . The third-stage contact slurry  658  mixes with the carrier gas  670 , producing more product solid, a warm third-stage product slurry, and the second-stage carrier gas  672 . Eductor  606  ends at a gas-liquid separator  618  which separates the third-stage carrier gas  672  from a third-stage product slurry  660 . The third-stage product slurry  660  consists of the warm third-stage contact slurry and the additional product solid. The third-stage product slurry  660  is cooled as it passes through heat exchanger  612 , forming a product slurry  662 . The product slurry  662  is then passed through a solid-liquid separation unit  620 . The separation unit  620 , in this example, represented as a filtering screw press, filters the first-stage contact fluid  650  out of the product solids  640 . Any remaining or evolved gases  678  are also separated from the product solids  640  in this unit. 
     The use of heat exchangers  608 ,  610 , and  612  after each eductor  602 ,  604 , and  606 , respectively, is done for efficiency gains. Cooling efficiency has an inverse relationship to the size of the temperature change. By using heat exchangers  608 ,  610 , and  612  after eductors  602 ,  604 , and  606  the fluid being cooled will need to be cooled less, and thus more efficiently, than if there was just one heat exchanger before the eductor  602  that cooled the fluid to a low enough temperature for the fluid to be useful through all three eductors  602 ,  604 , and  606 . The efficiency gains decrease the cost of operation, which should more than cover the cost of the extra heat exchangers. 
     In some embodiments, heat exchangers  608 ,  610 , and  612  are direct-contact gas-liquid heat exchangers. 
     In some embodiments, the eductors may be made of diamond, metal, plastic, ceramic, or a combination thereof. 
     Combustion flue gas consists of the exhaust gas from a fireplace, oven, furnace, boiler, steam generator, or other combustor. The combustion fuel sources include coal, hydrocarbons, and biomass. Combustion flue gas varies greatly in composition depending on the method of combustion and the source of fuel. Combustion in pure oxygen produces little to no nitrogen in the flue gas. Combustion using air leads to the majority of the flue gas consisting of nitrogen. The non-nitrogen flue gas consists of mostly carbon dioxide, water, and sometimes unconsumed oxygen. Small amounts of carbon monoxide, nitrogen oxides, sulfur dioxide, hydrogen sulfide, and trace amounts of hundreds of other chemicals are present, depending on the source. Entrained dust and soot will also be present in all combustion flue gas streams. The method disclosed applies to any combustion flue gases. Dried combustion flue gas has had the water removed. 
     Syngas consists of hydrogen, carbon monoxide, and carbon dioxide. 
     Producer gas consists of a fuel gas manufactured from materials such as coal, wood, or syngas. It consists mostly of carbon monoxide, with tars and carbon dioxide present as well. 
     Steam reforming is the process of producing hydrogen, carbon monoxide, and other compounds from hydrocarbon fuels, including natural gas. The steam reforming gas referred to herein consists primarily of carbon monoxide and hydrogen, with varying amounts of carbon dioxide and water. 
     Light gases include gases with higher volatility than water, including hydrogen, helium, carbon dioxide, nitrogen, and oxygen. This list is for example only and should not be implied to constitute a limitation as to the viability of other gases in the process. A person of skill in the art would be able to evaluate any gas as to whether it has higher volatility than water. 
     Refinery off-gases comprise gases produced by refining precious metals, such as gold and silver. These off-gases tend to contain significant amounts of mercury and other metals.