SISTEMAS E MÉTODOS PARA PURIFICAÇÃO DE AMÔNIA USANDO MEIOS DE ADSORÇÃO

Abstract

Systems and methods for purification of ammonia from an ammonia liquid feed stream, particularly ammonia recovered from a 2-column SWS unit, by vaporizing the ammonia liquid feed stream to produce a very cold (potentially subzero) ammonia vapor stream and passing the cooled ammonia vapor stream through an adsorption media such as activated to remove impurities from the cooled ammonia vapor stream and produce a purified ammonia vapor stream.

Description

1 / 5 SYSTEMS AND METHODS FOR AMMONIA PURIFICATION USING ADSORPTION MEDIA CROSS-REFERENCE TO RELATED REQUESTS

[001] This application claims priority to U.S. Provisional Application No. 63 / 509,459 filed June 21, 2023, which is incorporated herein by reference. This application and U.S. Patents Numbers 10,022,650, 10,702,799, 10,850,226, 10,266,418, 10,456,735, 10,843,122 and 10,315,153 each, of which are also incorporated herein by reference, are commonly attributed to Bechtel Energy Technologies and Solutions, Inc. FIELD OF THE INVENTION

[002] The present invention generally relates to systems and methods for ammonia purification using adsorption media. More particularly, the systems and methods improve the purification of ammonia from an ammonia liquid feed stream by vaporizing the ammonia liquid feed stream to produce a very cold (potentially below zero) ammonia vapor stream and passing the cooled ammonia vapor stream through an adsorption medium, such as activated carbon, to remove impurities from the cooled ammonia vapor stream and produce a purified ammonia vapor stream. BASIS OF THE INVENTION

[003] There is a known problem with ammonia recovered from certain 2-column acid water stripper (“SWS”) units, where the anhydrous ammonia product has an offensive odor. Apparently, humans can smell some odors at levels below ppm that exist in equilibrium with other precursors. Odor removal is difficult as the equilibrium causes it to reform. If a project, for example, is required to use recovered ammonia, commercially available ammonia should be purchased instead, as the project may be forced to incinerate the recovered ammonia. BRIEF DESCRIPTION OF THE DRAWING Petition 870250083322, dated 09 / 16 / 2025, page 31 / 46 2 / 5

[004] The detailed description is described below with reference to the attached drawing, in which similar elements are referenced with similar reference numbers, in which: FIG. 1 is a schematic diagram illustrating one embodiment of an ammonia purification system using activated carbon. DETAILED DESCRIPTION OF PREFERRED MODALITIES

[005] The subject matter of the present invention is described specifically; however, the description itself is not intended to limit the scope of the invention. The subject matter, therefore, may also be embodied in other ways, to include different structures, steps and / or combinations similar to and / or less than those described herein, in conjunction with other present or future technologies. Although the term "step" may be used herein to describe different elements of methods employed, the term should not be interpreted as implying any particular order among various steps described herein, unless expressly limited by the description to a particular order. Other features and advantages of the described embodiments will or will become apparent to one skilled in the art upon examination of the figures and detailed description that follow. It is intended that all such additional features and advantages are included within the scope of the described embodiments.Furthermore, the figures and dimensions illustrated herein are merely exemplary and are not intended to assert or imply any limitation with respect to the environment, architecture, design, or process in which different embodiments may be implemented. Insofar as temperatures and / or pressures are mentioned in the following description, these conditions are merely illustrative and are not intended to limit the invention. All flows described herein are transported by physical lines.

[006] The systems and methods described herein address the problems associated with the purification of ammonia from an ammonia liquid feed stream, particularly ammonia Petition 870250083322, dated 09 / 16 / 2025, pp. 32 / 46 3 / 5 recovered from a 2-column SWS unit, vaporizing the liquid ammonia feed stream to produce a very cold (potentially below zero) ammonia vapor stream and passing the cooled ammonia vapor stream through an adsorption medium, such as activated carbon, to remove impurities from the cooled ammonia vapor stream and produce a purified ammonia vapor stream.

[007] In one embodiment, a system for purifying ammonia is disclosed, comprising: i) a liquid ammonia feed stream; ii) a valve fluidly connected to the liquid ammonia feed stream and a cooled ammonia vapor stream to vaporize the liquid ammonia feed stream and produce the cooled ammonia vapor stream; and iii) a vessel comprising an adsorption means in fluid communication with the cooled ammonia vapor stream and producing a purified ammonia vapor stream.

[008] In another embodiment, a method for purifying ammonia is described, comprising: i) vaporizing a feed stream of liquid ammonia with a valve to produce a stream of cooled ammonia vapor; and ii) passing the cooled ammonia vapor stream through a vessel comprising an adsorption means to remove impurities from the cooled ammonia vapor stream and produce a stream of purified ammonia vapor.

[009] Referring now to FIG. 1, a schematic diagram illustrates one embodiment of an ammonia purification system 100. A liquid ammonia feed stream 102 is fed through a self-cooling valve 104, where it is vaporized by pressure reduction, being cooled to at least 50°F and preferably as low as about -30°F. The cooled liquid ammonia feed stream 106 from the valve 104 may optionally be fed to a separation drum 108 to produce a cold-washed vapor stream 110 Petition 870250083322, dated 09 / 16 / 2025, pp. 33 / 46 4 / 5 and a disposable liquid stream 111 if the ammonia liquid feed stream 102 is not completely vaporized and a portion of the ammonia liquid feed stream 102 (0%-50%, more preferably 0%-10%) is retained as a liquid. The idea is that some of the offending molecules may not vaporize and can be removed as a liquid, which will then be disposed of separately.

[010] The cold-washed steam stream 110 passes through an activated carbon vessel 112 (upward or downward flow) where it passes over, around and through activated carbon (with or without additives) and / or other adsorption, absorption or chemisorption media, such as silica gel, diatomaceous earth, any form of alumina (alpha, beta or gamma form; activated or not; with or without additives), or resin to produce a purified ammonia steam stream 114. The purified ammonia steam stream 114 is then fed through a first compressor 116 to produce another purified ammonia steam stream 118.

[011] Optionally, a water flow 119 may be introduced upstream or downstream of the first compressor 116 to improve the quality of the final ammonia product.

[012] The other purified ammonia vapor stream 118 and the water stream 119 are then fed to an intercooler 120 to produce a two-phase fluid stream 122, which is fed to an intercooler drum 124. The intercooler drum 124 separates the two-phase fluid stream 122 into a condensed waste liquid stream 126 and a partially recompressed vapor stream 128. The partially recompressed vapor stream 128 may be further compressed in a second compressor 130 to produce a recompressed ammonia vapor stream 132. The recompressed ammonia vapor stream 132 is condensed in a condenser 134 to produce a purified ammonia stream 136, which may be collected in a Petition 870250083322, dated 09 / 16 / 2025, pp. 34 / 46 5 / 5 drum accumulator 138. The systems and methods described here therefore allow for superior purification of recovered ammonia that might otherwise be lost due to unremoved impurities. The systems and methods described here further address the issues associated with ammonia recovered from 2-column SWS units.

[013] Although the present invention has been described in connection with currently preferred embodiments, it will be understood by those skilled in the art that the description of these embodiments is not intended to be limited. Therefore, it is contemplated that various alternative embodiments and modifications may be made to the described embodiments without departing from the spirit and scope of the invention as defined by the appended and equivalent claims thereof. Petition 870250083322, dated 09 / 16 / 2025, pp. 35 / 46

Claims

1 / 3 CLAIMS 1. A system for purifying ammonia, characterized in that it comprises: a liquid ammonia feed stream; a valve fluidly connected to the liquid ammonia feed stream and a cooled ammonia vapor stream to vaporize the liquid ammonia feed stream and produce the cooled ammonia vapor stream; and a vessel comprising an adsorption means in fluid communication with the cooled ammonia vapor stream to remove impurities from the cooled ammonia vapor stream and produce a purified ammonia vapor stream.

2. System according to claim 1, characterized in that the cooled ammonia vapor stream is cooled from a temperature of about 50°F (10°C) to about -30°F (34.4°C) using a self-cooling valve.

3. System according to claim 1, characterized in that the adsorption medium comprises activated carbon.

4. System according to claim 1, characterized in that it further comprises a separation drum positioned between the cooled ammonia vapor stream and the container for removing any liquid from the cooled ammonia vapor stream.

5. System according to claim 1, characterized in that it further comprises a first compressor in fluid communication with the purified ammonia vapor stream to compress the purified ammonia vapor stream into another purified ammonia vapor stream.

6. System according to claim 5, characterized in that it further comprises a water stream in fluid communication with another stream of purified ammonia vapor.

7. System, according to claim 6, characterized in that it further comprises an interstage cooler Petition 870250083322, dated 09 / 16 / 2025, page 36 / 46 2 / 3 in fluid communication with the water stream and the other stream of purified ammonia vapor to produce a two-phase fluid stream comprising water and purified ammonia.

8. System according to claim 7, characterized in that it further comprises an elimination drum in fluid communication with the two-phase fluid flow to separate the two-phase fluid flow into a condensed disposable liquid flow and a partially recompressed vapor flow.

9. System according to claim 8, characterized in that it further comprises a second compressor in fluid communication with the partially recompressed steam stream to compress the partially recompressed steam stream into a recompressed ammonia steam stream.

10. System according to claim 9, characterized in that it further comprises a condenser in fluid communication with the recompressed ammonia vapor stream for condensing the recompressed ammonia vapor stream into a purified ammonia stream.

11. A method for purifying ammonia, characterized in that it comprises: vaporizing a feed stream of liquid ammonia with a valve to produce a stream of cooled ammonia vapor; and passing the cooled ammonia vapor stream through a vessel comprising an adsorption medium to remove impurities from the cooled ammonia vapor stream and produce a stream of purified ammonia vapor.

12. Method according to claim 11, characterized in that the cooled ammonia vapor stream is cooled from a temperature of about 50°F (10°C) to about -30°F (34.4°C) using a self-cooling valve.

13. Method according to claim 11, characterized in that the adsorption medium comprises activated carbon. Petition 870250083322, dated 09 / 16 / 2025, pp. 37 / 46 3 / 3 14. Method according to claim 11, characterized in that it further comprises removing any liquid from the cooled ammonia vapor stream.

15. Method according to claim 11, characterized in that it further comprises compressing the purified ammonia vapor stream into another purified ammonia vapor stream.

16. Method according to claim 15, characterized in that it further comprises mixing a stream of water with another stream of purified ammonia vapor to produce a mixed liquid stream.

17. Method according to claim 16, characterized in that it further comprises cooling the mixed liquid stream to produce a two-phase fluid stream comprising purified water and ammonia.

18. Method according to claim 17, characterized in that it further comprises separating the two-phase fluid stream into a condensed disposable liquid stream and a partially recompressed vapor stream.

19. Method according to claim 18, characterized in that it further comprises compressing the partially recompressed vapor stream into a recompressed ammonia vapor stream.

20. Method according to claim 19, characterized in that it further comprises condensing the recompressed ammonia vapor stream into a purified ammonia stream. Petition 870250083322, dated 09 / 16 / 2025, pp. 38 / 46

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