Patent Application
20180320964
This invention relates generally to gas/vapor separation. More particularly, we are interested in using horizontal cross-flow spray towers for gas/vapor separation with a phase change.
The use of spray towers to accomplish heat and material exchange is of great use in many industries. Spray towers can be used to remove solids from a carrier gas, to cool a gas, to condense vapors out of gases as liquids, or to desublimate vapors out of gases as solids. While cross-flow horizontal spray towers are taught against in the art compared to countercurrent designs, countercurrent spray towers have unique problems with the last case—desublimation of vapors as solids. Cross-flow horizontal spray towers are not as efficient, liquid droplets are entrained from section to section, and contact time is reduced, but solids produced in cross-flow spray towers do not cascade downward into the next section and coat sprayers, resulting in blocked sprayers, as they do in countercurrent spray towers. However, cross-flow horizontal spray towers are still not as efficient as could be desired. A cross-flow horizontal spray tower with increased efficiency is required.
U.S. Pat. No. 4,039,307, to Bondor, teaches a countercurrent flow horizontal spray absorber. A gas is passed through a series of compartments, the compartments being separated by baffles. Each compartment has a spray that contacts the gas as an absorbent. The absorbent collects in the bottom of each compartment and is pumped to the next prior compartment to act as the spray. The present disclosure differs from this prior art disclosure in several ways. This prior art disclosure appears superficially to be a horizontal exchanger, but is rather a series of compartments that each act as vertical exchangers, similar to a vertical spray tower with multiple sections. As such, it is a series of countercurrent exchangers, and is not a cross-flow exchanger. The material being absorbed forms a soluble component in the absorbent, rather than forming a solid. The baffles would become fouled with solid if the present disclosure were used to produce solids. Further, the absorbent is passed through to provide maximum contact between the gas and the absorbent, not to establish an efficient temperature profile across the compartments. This prior art disclosure is pertinent and may benefit from the methods disclosed herein and is hereby incorporated for reference in its entirety for all that it teaches.
U.S. Pat. Nos. 4,343,771 and 4,269,812, to Edwards, et al., teach a horizontal cross-flow scrubber. The horizontal cross-flow gas liquid contactor increases sulfur dioxide removal by decreasing the interfering spray density through employment of a minimum critical spray nozzle spacing, reducing spray droplet collision and coalescence. The present disclosure differs from these prior art disclosures in that these prior art disclosures utilize a common liquid collection chamber and do not have any cascading coolant. These prior art disclosures are pertinent and may benefit from the methods disclosed herein and are hereby incorporated for reference in their entirety for all that they teach.
U.S. Pat. No. 4,948,402, to Davis, teaches a modular air scrubber system. A series of air scrubber units, each with an independent liquid reservoir, can be attached for air scrubbing. The present disclosure differs from this prior art disclosure in that this prior art disclosure utilizes countercurrent scrubbing and recycle of scrubbing liquid to the same unit, with no cascading coolant. This prior art disclosure is pertinent and may benefit from the methods disclosed herein and is hereby incorporated for reference in its entirety for all that it teaches.
A process for separating a gas and a vapor is disclosed. A cross-flow horizontal spray vessel comprising horizontally-situated sections is provided. Each of the sections comprise a spray nozzle or nozzles on an upper portion of the vessel, and a collection hopper on a lower portion of the vessel. A carrier gas, the carrier gas comprising a product vapor, is passed through the sections beginning at one end of the vessel. A contact liquid is provided through the spray nozzle or nozzles such that the carrier gas passes across the contact liquid and a portion of the product vapor desublimates, condenses, crystallizes, or combinations thereof as a product solid into the contact liquid, leaving a product-depleted carrier gas. The contact liquid and the product solid are collected in the collection hopper. The contact liquid and the product solid are passed to a next preceding upstream spray nozzle or nozzles such that a temperature profile is established across the sections by the contact liquid, as the contact liquid is progressively warmer, such that essentially complete desublimation, condensation, crystallization, or combinations thereof of the product vapor is accomplished across the sections. The contact liquid and the product solid are removed from a furthermost upstream section as a product slurry. The product-depleted carrier gas is removed from a furthermost downstream section of the vessel. In this manner, the carrier gas and the product vapor are separated.
The temperature profile of the vessel varies less than a counter-current flow vessel temperature profile.
The passing the contact liquid and the product step is accomplished by pumping. A process controller may be provided. The pumping is accomplished by pumps comprising variable speed drives wherein pumping speeds are controlled by the process controller.
Heat exchangers may be provided between the collection hoppers and the next preceding upstream spray nozzle or nozzles, the heat exchangers modifying the temperature profile to increase efficiency of separations. Solid-liquid separation devices may be provided between the collection hoppers and the next preceding upstream spray nozzle or nozzles, the solid-liquid separation devices removing the product solid from the contact liquid.
The product slurry may be separated into a warm contact liquid and a final product solid. The warm contact liquid may be passed through a heat exchanger to produce the contact liquid. The final product solid may be pressurized and melted to produce a final product liquid.
A mist eliminator may be provided to remove any of the contact liquid entrained in the product-depleted carrier gas leaving the vessel. The contact liquid removed by the mist eliminator may be combined with the product slurry.
A recuperative heat exchanger may be provided to warm the product-depleted carrier gas.
The spray nozzle or nozzles may comprise flat-fan nozzles, hollow-cone nozzles, full-cone nozzles, misting nozzles, solid-stream nozzles, atomizing nozzles, rotary jet nozzles, or combinations thereof. The spray nozzle or nozzles may comprise a design capable of allowing solid particulates to pass through the spray nozzle or nozzles of up to 0.25 inch.
The carrier gas may comprise flue gas, syngas, producer gas, natural gas, steam reforming gas, hydrocarbons, light gases, refinery off-gases, organic solvents, water, ammonia, liquid ammonia, or combinations thereof.
The product vapor may comprise carbon dioxide, nitrogen oxide, sulfur dioxide, nitrogen dioxide, sulfur trioxide, hydrogen sulfide, hydrogen cyanide, water, mercury, hydrocarbons, pharmaceuticals, salts, biomass, or combinations thereof.
The contact liquid may comprise 1,1,3-trimethylcyclopentane, 1,4-pentadiene, 1,5-hexadiene, 1-butene, 1-methyl-1-ethylcyclopentane, 1-pentene, 5,3,3,3-tetrafluoropropene, 5,3-dimethyl-1-butene, 5-chloro-1,1,1,2-tetrafluoroethane, 5-methylpentane, 5-methyl-1,4-pentadiene, 5-methyl-1-butene, 5-methyl-1-pentene, 5-methylpentane, 4-methyl-1-hexene, 4-methyl-1-pentene, 4-methylcyclopentene, 4-methyl-trans-2-pentene, bromochlorodifluoromethane, bromodifluoromethane, bromotrifluoroethylene, chlorotrifluoroethylene, cis 5-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, methylcyclopropane, 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 combinations thereof.
The contact liquid may comprise any compound or mixture of compounds with a freezing point above a temperature at which the product vapor condenses, desublimates, crystallizes, or a combination thereof.
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:
It will be readily understood that the components of the present invention, 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 invention, as represented in the Figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of certain examples of presently contemplated embodiments in accordance with the invention.
Referring to
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In some embodiments, product slurry 446 is separated into a warm contact liquid and a final product. The warm contact liquid is combined with contact liquid 448 and is passed through a heat exchanger to produce contact liquid 444. The final product is pressurized and melted to produce a final product liquid.
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In some embodiments, product slurry 546 is separated into a warm contact liquid and a final product. The warm contact liquid is combined with contact liquid 548 and is passed through a heat exchanger to produce contact liquid 544. The final product is pressurized and melted to produce a final product liquid.
Referring to
In some embodiments, the temperature profile of the vessel varies less than a counter-current flow vessel temperature profile. This minimization of variation provides a useful increase in efficiency.
In some embodiments, a process controller is provided. In some embodiments, the pumping is accomplished by pumps comprising variable speed drives wherein pumping speeds are controlled by the process controller.
In some embodiments, heat exchangers are provided between the collection hoppers and the next preceding upstream spray nozzle or nozzles, the heat exchangers modifying the temperature profile to increase efficiency of separations. In some embodiments, solid-liquid separation devices are provided between the collection hoppers and the next preceding upstream spray nozzle or nozzles, the solid-liquid separation devices removing the product solid from the contact liquid.
In some embodiments, a recuperative heat exchanger is provided to warm the product-depleted carrier gas.
In some embodiments, the spray nozzle or nozzles comprise flat-fan nozzles, hollow-cone nozzles, full-cone nozzles, misting nozzles, solid-stream nozzles, atomizing nozzles, rotary-jet nozzles, or combinations thereof.
In some embodiments, the carrier gas comprises flue gas, syngas, producer gas, natural gas, steam reforming gas, hydrocarbons, light gases, refinery off-gases, organic solvents, water, ammonia, liquid ammonia, or combinations thereof.
In some embodiments, the product vapor comprises carbon dioxide, nitrogen oxide, sulfur dioxide, nitrogen dioxide, sulfur trioxide, hydrogen sulfide, hydrogen cyanide, water, mercury, hydrocarbons, pharmaceuticals, salts, biomass, or combinations thereof.
In some embodiments, the contact liquid comprises 1,1,3-trimethylcyclopentane, 1,4-pentadiene, 1,5-hexadiene, 1-butene, 1-methyl-1-ethylcyclopentane, 1-pentene, 5,3,3,3-tetrafluoropropene, 5,3-dimethyl-1-butene, 5-chloro-1,1,1,2-tetrafluoroethane, 5-methylpentane, 5-methyl-1,4-pentadiene, 5-methyl-1-butene, 5-methyl-1-pentene, 5-methylpentane, 4-methyl-1-hexene, 4-methyl-1-pentene, 4-methylcyclopentene, 4-methyl-trans-2-pentene, bromochlorodifluoromethane, bromodifluoromethane, bromotrifluoroethylene, chlorotrifluoroethylene, cis 5-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, methylcyclopropane, 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, methanol, ethanol, 1-propanol, 2-propanol, aqueous mixtures thereof, or combinations thereof.
In some embodiments, the contact liquid comprises any compound or mixture of compounds with a freezing point above a temperature at which the product vapor condenses, desublimates, crystallizes, or a combination thereof.
This invention was made with government support under DE-FE0028697 awarded by The Department of Energy. The government has certain rights in the invention.
