Patent Application
20230008997
The present disclosure relates generally to packed distillation columns, and more particularly, to a method for removing super-heat from column vapor feeds.
Generally, packed distillation columns are zones where liquid and vapor phases are concurrently contacted to effect separation of a fluid mixture through contacting of the vapor and liquid phases on packing elements or on a series of vertically spaced trays mounted within the column. A dual column includes a higher-pressure column (e.g., lower column (LC)) with its upper end in heat exchange relation with the lower end of a lower-pressure column (e.g., higher column (HC)).
A column section is a zone in the column having a top or bottom where vapor or liquid is removed from or enters a column. Structured packing within a section of a column has been developed as a mass transfer element because it has a lower pressure drop than trays and has more predictable performance than random packing. Structured packing is packing with individual members with specific orientations relative to each other and to the column axis. However, when hydraulic loads are substantially different in different sections of a column, one or more sections may be closer to flooding than other sections.
Within a dual column system, the LC having the higher pressure may have vapor feeds with a 5 degree K or more super-heat. A section of the LC that is packed with structured packing (LC−1 section) may be trayed to avoid maldistribution of the super-heated vapor and uneven liquid boil off from the structured packing of the LC−1 section. The trayed LC−1 section adds to the pressure drop of the LC compared to a case in which the entire LC is packed with structured packing. If boil off occurs unevenly on the surface of the structured packing, the maldistribution leads to performance shortfalls.
According to one embodiment, a system is provided for reducing a vapor temperature in a packed distillation column. The system includes a packed section of the packed distillation column. The system also includes a liquid collector disposed below the packed section and collecting liquid from the packed section. The system further includes a vapor feed disposed below the packed section and distributing a super-heated vapor such that the super-heated vapor contacts the liquid of the liquid collector and reduces a temperature of the super-heated vapor.
According to one embodiment, a method is provided for reducing a vapor temperature in a packed distillation column. Liquid is collected from a packed section of the packed distillation column in a liquid collector disposed below the packed section. A super-heated vapor is distributed from a vapor feed disposed below the packed section such that the super-heated vapor contacts the liquid of the liquid collector and reduces a temperature of the super-heated vapor.
The above and other aspects, features, and advantages of certain embodiments of the present disclosure will be more apparent from the following detailed description, when taken in conjunction with the accompanying drawings, in which:
Hereinafter, embodiments of the present disclosure are described in detail with reference to the accompanying drawings. It should be noted that the same elements will be designated by the same reference numerals although they are shown in different drawings. In the following description, specific details such as detailed configurations and components are merely provided to assist with the overall understanding of the embodiments of the present disclosure. Therefore, it should be apparent to those skilled in the art that various changes and modifications of the embodiments described herein may be made without departing from the scope of the present disclosure. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness. The terms described below are terms defined in consideration of the functions in the present disclosure, and may be different according to users, intentions of the users, or customs. Therefore, the definitions of the terms should be determined based on the contents throughout this specification.
The present disclosure may have various modifications and various embodiments, among which embodiments are described below in detail with reference to the accompanying drawings. However, it should be understood that the present disclosure is not limited to the embodiments, but includes all modifications, equivalents, and alternatives within the scope of the present disclosure.
Although the terms including an ordinal number such as first, second, etc. may be used for describing various elements, the structural elements are not restricted by the terms. The terms are only used to distinguish one element from another element. For example, without departing from the scope of the present disclosure, a first structural element may be referred to as a second structural element. Similarly, the second structural element may also be referred to as the first structural element. As used herein, the term “and/or” includes any and all combinations of one or more associated items.
The terms used herein are merely used to describe various embodiments of the present disclosure but are not intended to limit the present disclosure. Singular forms are intended to include plural forms unless the context clearly indicates otherwise. In the present disclosure, it should be understood that the terms “include” or “have” indicate the existence of a feature, a number, a step, an operation, a structural element, parts, or a combination thereof, and do not exclude the existence or probability of the addition of one or more other features, numerals, steps, operations, structural elements, parts, or combinations thereof.
Unless defined differently, all terms used herein have the same meanings as those understood by a person skilled in the art to which the present disclosure belongs. Terms such as those defined in a generally used dictionary are to be interpreted to have the same meanings as the contextual meanings in the relevant field of art, and are not to be interpreted to have ideal or excessively formal meanings unless clearly defined in the present disclosure.
Embodiments of the present disclosure provide a self-supporting de-superheating collector tray below a packed column section. The de-superheating collector tray serves two purposes. First, the tray collects liquid falling from the structured packing above. Thus, the structured packing does not require a separate collector. Second, due to the pressure drop, the tray evenly distributes the incoming super-heated vapor feed, bringing it into contact with the collected liquid. Accordingly, any vaporization that occurs will be uniform, resolving any potential maldistribution issues in the structured packing above.
The packed column section of
Accordingly, when the disclosure is embodied in a packed LC−1 section, the de-superheating collector tray leads to significant pressure drop savings in the LC, which would otherwise have a trayed LC−1 section due to the super-heat of the incoming vapor feed.
In another embodiment. which may be used separately or in combination with the embodiment of
Initially, at 402, liquid is collected, at a liquid collector, from a packed section of the column. The liquid collector is disposed below the packed section.
When the liquid collector is a collector tray disposed above the vapor feed, the liquid collected at the collector tray falls from the packed section. The collector tray includes a perforated deck through which the super-heated vapor contacts the collected liquid.
When the liquid collector is a trough disposed below the vapor feed, the collected liquid is at least a portion of liquid provided from the packed section to a collector sump. An alternative embodiment may include both the collector tray and the trough.
At 404, a super-heated vapor is distributed from a vapor feed disposed below the packed section. The super-heated vapor contacts the liquid of the liquid collector and reduces a temperature of the super-heated vapor.
When the liquid collector is the collector tray disposed above the vapor feed, the super-heated vapor is evenly distributed below the collector tray. When the liquid collector is the trough, the super-heated vapor is evenly distributed downwardly toward a surface of the liquid in the trough.
The apparatus also includes the processor 506 for controlling the distribution of super-heated vapor from a vapor feed. Additionally, the apparatus may include a communication interface 508 that receives, transmits, and/or outputs signals.
Although certain embodiments of the present disclosure have been described in the detailed description of the present disclosure, the present disclosure may be modified in various forms without departing from the scope of the present disclosure. Thus, the scope of the present disclosure shall not be determined merely based on the described embodiments, but rather determined based on the accompanying claims and equivalents thereto.
