Patent Description:
There is a continuous growing demand for iso-pentanes. Iso-pentanes can be used as solvents, in geothermal production plants, as blend stocks for gasoline and methyl tertiary butyl ether (MTBE), etc. Iso-pentane has an octane number over <NUM> and can be use as octane boosters. Substantially pure iso-pentane without a high percentage of n-pentane and neo-pentane is preferred because octane number of iso-pentane is higher than that of n-pentane and neo-pentane. Flaring or burning can be minimized with substantially pure iso-pentane i.e., without high percentage of n-pentane and neo-pentane. Pentanes can be obtained from a DIB unit.

<NPL>") describes maximizing yields from a DIB and discloses design and operating considerations that should be addressed when capacity and efficiency improvements are desired. Musumeci et al. doesn't disclose processing a pentanes stream obtained from a DIB unit to produce additional iso-pentane.

While attempts have been made to optimize the process for production of iso-pentane, these processes tend to suffer from inefficient production of substantially pure iso-pentane and/or increased production costs. <CIT> discloses a method which comprises thermally steam cracking, in the presence of steam at thermal steam cracking conditions, a hydrocarbon thermal steam cracking charge stream including (i) a hydrocarbon component containing at least about <NUM> carbon atoms and (ii) deisobutanized C3 to C5 paraffin stream thereby forming a product stream containing (i) an ethylene fraction and (ii) a C3 to C4 olefin fraction; and recovering said product stream. <CIT> describes a process for the production of high octane number gasoline by isomerization of a light naphtha cut, comprising two separation steps located downstream of the reaction step which can be used to improve the energy efficiency of said process.

The invention provides a method according to claim <NUM>. A discovery has been made that provides a solution to some of the afore mentioned problems. The solution is premised on processing a pentanes stream containing iso-pentane, n-pentane and neo-pentane from a DIB unit, separating iso-pentane from n-pentane and neo-pentane to obtain a sufficiently pure isopentane, and producing additional iso-pentane from the separated n-pentane and neo-pentane.

In the present invention, a method for processing a pentanes stream is described. In certain aspects, the process can include steps (a) or (b) or both (a) and (b). In step (a) a first stream containing pentanes can be separated in a separation column to obtain a second stream containing iso-pentane and a third stream containing n-pentane and neo-pentane. In step (b) the third stream can be fed to a butane isomerization unit producing a fourth stream containing isopentane, n-pentane, and neo-pentane. The first stream is obtained from a DIB unit. In some aspects, the third stream can be desulfurized prior to subjecting the third stream to the butane isomerization unit. In some aspects, the desulfurization process can include absorption and removing of sulfur containing compounds from the third stream by an adsorbent. In some aspects, the adsorbent can be zeolite 13X and/or activated charcoal. In some particular aspects, the desulfurization process can include passing the third stream over and/or through an adsorbent bed such as a zeolite 13X molecular sieve bed or an activated charcoal bed. A spent adsorbent can be formed by absorption of the sulfur containing compounds by the adsorbent. In some aspects, the adsorbent can be regenerated from the spent adsorbent. In the butane isomerization unit the third stream can be contacted with a isomerization catalyst. In some aspects, the third stream can be contacted with the isomerization catalyst under conditions including i) a temperature of <NUM> to <NUM>; ii) a pressure of <NUM> to <NUM> bar; iii) a WHSV of <NUM>-<NUM> to <NUM>-<NUM> or <NUM>-<NUM> to <NUM>-<NUM>; or any combination thereof.

The isomerization catalyst can be a butane isomerization catalyst known in the art. In some aspects, the isomerization catalyst can be platinum chlorinated alumina (Pt/Al<NUM>O<NUM>-Cl) catalyst, platinum zirconia sulfate catalyst (Pt/ZrO<NUM>-SO<NUM>) and/or a zeolite such as iso shape selective zeolites. In the butane isomerization unit at least a portion of the n-pentane and/or neo-pentane from the third stream can be isomerized to form iso-pentane. In some aspects, a feed stream containing n-butane can be fed to the butane isomerization unit and the fourth stream can further include iso-butane. In some aspects, the feed stream can further contain isobutane, iso-pentane, n-pentane, and neo-pentane. In some aspects, the feed stream can be desulfurized prior to feeding the feed stream to the butane isomerization unit. In some aspects, the third stream and the feed stream can be fed to the butane isomerization unit as separate feeds. In some other aspects, the third stream and the feed stream can be fed to the butane isomerization unit as a combined feed. In some aspects, the third stream and feed stream can be combined to form the combined feed, the combined feed can be desulfurized and then fed to the butane isomerization unit. In some aspects, the third stream and the feed stream can be combined after desulfurization of the respective streams and the combined feed can be fed to the butane isomerization unit. The fourth stream can be fed to a DIB unit. In some aspects, the fourth stream can be fed to the DIB unit from which the first stream is obtained. In some aspects, the fourth stream can be fed to a DIB unit (second DIB unit), that is different from the DIB unit (first DIB unit) from which the first stream is obtained. In some aspects, the DIB unit can include a DIB column. In some aspects, the DIB column operation condition to obtain the first stream can include a temperature of <NUM> to <NUM> , or <NUM> to <NUM> , or <NUM> to <NUM>. In some aspects, the DIB column operation condition to obtain the first stream can include a reboiler range of <NUM> to <NUM>, or <NUM> to <NUM> , or <NUM> to <NUM>. In some aspects, the DIB column operation condition to obtain the first stream can include an operation gauge pressure of <NUM> bar to <NUM> bar or <NUM> bar to <NUM> bar or <NUM> bar to <NUM> bar or <NUM> bar to <NUM> bar. In some aspects, the DIB column operation condition to obtain the first stream can include a temperature of <NUM> to <NUM> , a reboiler range of <NUM> to <NUM>, an operation gauge pressure of <NUM> to <NUM> bar, or any combination thereof. In some aspects, the DIB column can include <NUM> to <NUM>, or <NUM> to <NUM>, or <NUM> to <NUM>, trays. The first stream can be obtained as a bottom stream from the DIB column. The first stream can contain <NUM> wt. % to <NUM> wt. % or <NUM> wt. % to <NUM> wt. % iso-pentane. The first stream can contain <NUM> wt. % to <NUM> wt. % or <NUM> wt. % to <NUM> wt. % n-pentane. The first stream can contain <NUM> wt. % to <NUM> wt. % or <NUM> wt. % to <NUM> wt. % neo-pentane. In some aspects, the first stream can contain <NUM> wt. % to <NUM> wt. % iso-pentane, <NUM> wt. % to <NUM> wt. % n-pentane, and <NUM> wt. % to <NUM> wt. % neo-pentane. The separation column in step (a) can be a deisopentanizer column. In some aspects, the deisopentanizer column operation condition during the separation of the first stream can include an overhead boiling range temperature of <NUM> to <NUM> , or <NUM> to <NUM> , or <NUM> to <NUM>. In some aspects, the deisopentanizer column operation condition during the separation of the first stream can include a reboiler range of <NUM> to <NUM>, or <NUM> to <NUM>, or <NUM> to <NUM>, or <NUM> to <NUM>, or <NUM> to <NUM>. In some aspects, the deisopentanizer column operation condition during the separation of the first stream can include an operation gauge pressure of <NUM> bar to <NUM> bar or <NUM> bar to <NUM> bar or <NUM> bar to <NUM> bar or <NUM> bar to <NUM> bar. In some aspects, the deisopentanizer column operation condition during the separation of the first stream can include an overhead reflux to feed ratio of <NUM> to <NUM> or <NUM> to <NUM> or <NUM> to <NUM>. In some aspects, the deisopentanizer column operation condition during the separation of the first stream can include an overhead boiling range temperature of <NUM> to <NUM>, a reboiler range of <NUM> to <NUM>, an operation gauge pressure of <NUM> to <NUM> bar, overhead reflux to feed ratio of <NUM> to <NUM> or any combination thereof. In some aspects, the deisopentanizer column can include <NUM> to <NUM>, or <NUM> to <NUM>, or <NUM> to <NUM>, trays. In some aspects, in step (a) the third stream can be obtained as a bottom stream and the second stream can be obtained as a side stream from the deisopentanizer column. In some aspects the side stream can be a side-draw liquid stream. In some aspects the bottom stream can be a bottom-draw liquid stream. In some aspects, the second stream can contain <NUM> wt. % to <NUM> wt. %, or <NUM> wt. % to <NUM> wt. %, or <NUM> wt. % to <NUM> wt. % or <NUM> wt. % to <NUM> wt. %, of iso-pentane. In some aspects, the second stream can contain <NUM> wt. % to <NUM> wt. %, or <NUM> wt. % to <NUM> wt. %, or <NUM> wt. % to <NUM> wt. % or <NUM> wt. % to <NUM> wt. %, of n-pentane and neo-pentane. In some aspects, the second stream can contain less than <NUM> wt. %, or <NUM> wt. % to <NUM> wt. %, or <NUM> wt. % to <NUM> wt. %, of sulfur, where the sulfur is present as sulfur containing organosulfur compounds. The third stream can contain <NUM> wt. % to <NUM> wt. % or <NUM> wt. % to <NUM> wt. % or <NUM> wt. % to <NUM> wt. % n-pentane. The third stream can contain <NUM> wt. % to <NUM> wt. % or <NUM> wt. % to <NUM> wt. % neo-pentane. In some aspects, the third stream can contain, <NUM> wt. % to <NUM> wt. % n-pentane, and <NUM> wt. % to <NUM> wt. % neo-pentane. In some aspects, the first stream can further contain n-butane, and in step (a) the first stream can be separated to obtain the second stream, the third stream and a fifth stream containing n-butane. In some aspects, the fifth stream is obtained as a top stream from the deisopentanizer column. In some particular aspects, the first stream can contain <NUM> wt. % to <NUM> wt. % of n-butane. In some particular aspects, the fifth stream can contain <NUM> wt. % to <NUM> wt. % of n-butane. In some aspects, at least a portion of the iso-pentane of the second stream can be used as a blend stock for gasoline and/or blend stock for MTBE. In some aspects, a portion of the third stream is fed to the butane isomerization unit and a portion of the third stream is used a boiler fuel and/or for product blending.

Other embodiments of the invention are discussed throughout this application. Any embodiment discussed with respect to one aspect of the invention applies to other aspects of the invention as well and vice versa. Each embodiment described herein is understood to be embodiments of the invention that are applicable to other aspects of the invention. It is contemplated that any embodiment discussed herein can be implemented with respect to any method of the invention, and vice versa.

In one non-limiting embodiment, the terms are defined to be within <NUM>%, preferably within <NUM>%, more preferably within <NUM>%, and most preferably within <NUM>%.

The terms "wt. %," or "mol. %" refers to a weight percentage of a component, a volume percentage of a component, or molar percentage of a component, respectively, based on the total weight, the total volume of material, or total moles, that includes the component. In a non-limiting example, <NUM> grams of component in <NUM> grams of the material is <NUM> wt. % of component.

The terms "inhibiting" or "reducing" or "preventing" or "avoiding" or any variation of these terms, when used in the claims and/or the specification includes any measurable decrease or complete inhibition to achieve a desired result.

The use of the words "a" or "an" when used in conjunction with any of the terms "comprising," "including," "containing," or "having" in the claims, or the specification, may mean "one," but it is also consistent with the meaning of "one or more," "at least one," and "one or more than one.

The phrase "and/or" means "and" or "or". To illustrate, A, B, and/or C includes: A alone, B alone, C alone, a combination of A and B, a combination of A and C, a combination ofB and C, or a combination of A, B, and C. In other words, "and/or" operates as an inclusive or.

The process of the present invention can "comprise," "consist essentially of," or "consist of" particular ingredients, components, compositions, steps, etc. disclosed throughout the specification. With respect to the transitional phrase "consisting essentially of," in one non-limiting aspect, a basic and novel characteristic of the processes of the present invention are their abilities to process a pentanes stream containing iso-pentane, n-pentane, and neo-pentane from a DIB to obtain a stream containing iso-pentane, and a stream containing n-pentane, and neo-pentane, subjecting the stream containing n-pentane, and neo-pentane to a butane isomerization unit to obtain a stream containing iso-pentane, n-pentane and neo-pentane.

Other objects, features and advantages of the present invention will become apparent from the following figures, detailed description, and examples. It should be understood, however, that the figures, detailed description, and examples, while indicating specific embodiments of the invention, are given by way of illustration only and are not meant to be limiting. Additionally, it is contemplated that changes and modifications within the scope of the claims will become apparent to those skilled in the art from this detailed description. In further embodiments, features from specific embodiments may be combined with features from other embodiments, within the scope of the claims. For example, features from one embodiment may be combined with features from any of the other embodiments, within the scope of the claims.

Advantages of the present invention may become apparent to those skilled in the art with the benefit of the following detailed description and upon reference to the accompanying drawings.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings. The drawings may not be to scale.

A discovery has been made that provides a solution to some of the aforementioned problems. The solution is premised on processing a pentanes stream containing iso-pentane, n-pentane, and neo-pentane from a DIB unit to recover iso-pentane, and producing additional iso-pentane from at least a portion of the resulting leftover stream. The leftover stream after iso-pentane recovery can contain n-pentane and neo-pentane. It was surprisingly found that recycling the left over stream to a butane isomerization unit can drive the equilibrium towards iso-pentane and convert n-pentane and/or neo-pentane to iso-pentane. The butane isomerization unit can be a butane isomerization unit of an iso-butane production process. The left over stream can be fed to the butane isomerization unit during a iso-butane production process.

These and other non-limiting aspects of the present invention are discussed in further detail in the following paragraphs with reference to the figures.

Referring to <FIG>, one example of the process of the present invention for processing pentanes from a DIB unit is described. System <NUM> can include a separation column <NUM>, and a butane isomerization unit <NUM>. A first stream <NUM> can be fed to the separation column <NUM>. The first stream can be obtained from a DIB unit (not shown). The first stream can contain iso-pentane, n-pentane, and neo-pentane. In the separation column <NUM> the first stream <NUM> can be separated into a second stream <NUM> containing iso-pentane and a third stream <NUM> containing n-pentane and neo-pentane. The third stream <NUM> can be fed to the butane isomerization unit <NUM>. The butane isomerization unit <NUM> can contain an isomerization catalyst (not shown) and the isomerization catalyst can catalyze isomerization of n-pentane and/or neo-pentane to iso-pentane. A fourth stream <NUM> containing iso-pentane, n-pentane, and neo-pentane can be obtained from the butane isomerization unit <NUM>.

Referring to <FIG>, another example of the process of the present invention for processing pentanes from a DIB unit is described. System <NUM> can include a separation column <NUM>, a butane isomerization unit <NUM>, a desulfurization unit <NUM> and a DIB unit <NUM>. A first stream <NUM> can be fed to the separation column <NUM>. The first stream can be obtained from a DIB unit <NUM>. The first stream can contain iso-pentane, n-pentane, and neo-pentane. In the separation column <NUM> the first stream <NUM> can be separated into a second stream <NUM> containing iso-pentane and a third stream <NUM> containing n-pentane and neo-pentane. The third stream <NUM> can be fed to the desulfurization unit <NUM>. In the desulfurization unit <NUM> the third stream <NUM> can be desulfurized to obtain a desulfurized third stream 216c. The desulfurized third stream 216c can be fed to the butane isomerization unit <NUM>. The butane isomerization unit <NUM> can contain an isomerization catalyst (not shown) and the isomerization catalyst can catalyze isomerization of n-pentane and/or neo-pentane to iso-pentane. A fourth stream <NUM> containing iso-pentane, n-pentane, and neo-pentane can be obtained from the butane isomerization unit <NUM>.

Referring to <FIG>, another example of the process of the present invention for processing pentanes from a DIB unit is described. System <NUM> can include a separation column <NUM>, a butane isomerization unit <NUM>, a desulfurization unit <NUM> and a DIB unit <NUM>. A first stream <NUM> can be fed to the separation column <NUM>. The first stream <NUM> can contain n-butane, iso-pentane, n-pentane, and neo-pentane. The first stream <NUM> can be obtained from the DIB unit <NUM>. In the separation column <NUM> the first stream <NUM> can be separated into a second stream <NUM> containing iso-pentane, a third stream <NUM> containing n-pentane and neo-pentane and a fifth stream <NUM> containing n-butane. A portion 316a of the third stream can be fed to the desulfurization unit <NUM>. In the desulfurization unit <NUM> the stream 316a can be desulfurized to obtain a desulfurized third stream 316c. The desulfurized third stream 316c can be fed to the butane isomerization unit <NUM>. A portion of the third stream 316b can be used as boiler fuel and/or product blending. A feed stream <NUM> containing n-butane can be fed to the butane isomerization unit <NUM>. In some aspects, the feed stream <NUM> can further include iso-butane, n-pentane, iso-pentane, and neo-pentane. In some aspects, the desulfurized third stream 316c and the feed stream <NUM> can be fed to the butane isomerization unit <NUM> as separate feeds. In some aspects, the desulfurized third stream 316c and the feed stream <NUM> can be fed to the butane isomerization unit <NUM> as a combined feed (not shown). The feed stream <NUM> can be desulfurized (not shown) and then fed to the butane isomerization unit <NUM>. The butane isomerization unit <NUM> can contain an isomerization catalyst (not shown) and the isomerization catalyst can catalyze isomerization of n-pentane and/or neo-pentane to iso-pentane and n-butane to iso-butane. A fourth stream <NUM> containing n-butane, iso-butane, iso-pentane, n-pentane, and neo-pentane can be obtained from the butane isomerization unit <NUM>. The fourth stream can be fed to the DIB unit <NUM>. In the DIB unit <NUM> the fourth stream can be separated to obtain the first stream <NUM> and a sixth stream <NUM> containing iso-butane.

Referring to <FIG>, another example of the process of the present invention for processing pentanes from a DIB unit is described. System <NUM> can include a separation column <NUM>, a butane isomerization unit <NUM>, a desulfurization unit <NUM> and a DIB unit <NUM>. A first stream <NUM> can be fed to the separation column <NUM>. The first stream <NUM> can contain n-butane, iso-pentane, n-pentane, and neo-pentane. The first stream <NUM> can be obtained from the DIB unit <NUM>. In the separation column <NUM> the first stream <NUM> can be separated into a second stream <NUM> containing iso-pentane, a third stream <NUM> containing n-pentane and neo-pentane and a fifth stream <NUM> containing n-butane. A portion 416a of the third stream can be fed to the desulfurization unit <NUM>. A feed stream <NUM> containing n-butane can be fed to the desulfurization unit <NUM>. In some aspects, the feed stream <NUM> can further include iso-butane, n-pentane, iso-pentane and neo-pentane. In some aspects, the stream 416a and the feed stream <NUM> can be fed to the desulfurization unit <NUM> as separate feeds (not shown). In some aspects, the stream 416a and the feed stream <NUM> can be fed to the desulfurization unit <NUM> as a combined feed. In the desulfurization unit <NUM> the feed stream <NUM> and the stream 416a can be desulfurized to obtain a desulfurized combined stream <NUM>. The desulfurized combined stream <NUM> can be fed to the butane isomerization unit <NUM>. A portion of the third stream 416b can be used as boiler fuel and/or product blending. The butane isomerization unit <NUM> can contain an isomerization catalyst (not shown) and the isomerization catalyst can catalyze isomerization of n-pentane and/or neo-pentane to iso-pentane and n-butane to iso-butane. A fourth stream <NUM> containing n-butane, iso-butane, iso-pentane, n-pentane, and neo-pentane can be obtained from the butane isomerization unit <NUM>. The fourth stream can be fed to the DIB unit <NUM>. In the DIB unit <NUM> the fourth stream can be separated to obtain the first stream <NUM> and a sixth stream <NUM> containing iso-butane.

Referring to <FIG>, another example of the process of the present invention for processing pentanes from a DIB unit is described. System <NUM> can include a separation column <NUM>, a butane isomerization unit <NUM>, a desulfurization unit <NUM> and DIB units <NUM> and <NUM>. A first stream <NUM> can be fed to the separation column <NUM>. The first stream <NUM> can contain n-butane, iso-pentane, n-pentane, and neo-pentane. The first stream <NUM> can be obtained from the DIB unit <NUM>. In the separation column <NUM> the first stream <NUM> can be separated into a second stream <NUM> containing iso-pentane, a third stream <NUM> containing n-pentane and neo-pentane and a fifth stream <NUM> containing n-butane. A portion 516a of the third stream can be fed to the desulfurization unit <NUM>. A feed stream <NUM> containing n-butane can be fed to the desulfurization unit <NUM>. In some aspects, the feed stream <NUM> can further include iso-butane, n-pentane, iso-pentane, and neo-pentane. In some aspects, the stream 516a and the feed stream <NUM> can be fed to the desulfurization unit <NUM> as separate feeds. In some aspects, stream 516a and the feed stream <NUM> can be fed to the desulfurization unit <NUM> as a combined feed (not shown). In the desulfurization unit <NUM> the feed stream <NUM> and the stream 516a can be desulfurized to obtain a desulfurized combined stream <NUM>. The desulfurized combined stream <NUM> can be fed to the butane isomerization unit <NUM>. A portion of the third stream 516b can be used as boiler fuel and/or product blending. The butane isomerization unit <NUM> can contain an isomerization catalyst (not shown) and the isomerization catalyst can catalyze isomerization of n-pentane and/or neo-pentane to iso-pentane and n-butane to iso-butane. A fourth stream <NUM> containing n-butane, iso-butane, iso-pentane, n-pentane, and neo-pentane can be obtained from the butane isomerization unit <NUM>. The fourth stream can be fed to the DIB unit <NUM>. In the DIB unit <NUM> the fourth stream <NUM> can be separated to obtain a seventh stream <NUM> containing iso-pentane, n-pentane and neo-pentane. The pentanes from the seventh stream <NUM> can be processed according to any examples described herein.

The first stream <NUM>, <NUM>, <NUM>, <NUM>, <NUM> can contain (<NUM>) <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %,and <NUM> wt. % of isopentane; (<NUM>) <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, and <NUM> wt. % of n-pentane; (<NUM>) <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, and <NUM> wt. %, of neo-pentane; or (<NUM>) <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, and <NUM> wt. %, of n-butane; or any combination thereof.

The second stream <NUM>, <NUM>, <NUM>, <NUM>, <NUM> can contain <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, and <NUM> wt. % of isopentane. The total wt. % of n-pentane and neo-pentane in the second stream <NUM>, <NUM>, <NUM>, <NUM>, <NUM> can be less than <NUM> wt. In some aspects, the total wt. % of n-pentane and neo-pentane in the second stream <NUM>, <NUM>, <NUM>, <NUM>, <NUM> can be <NUM> wt. % to <NUM> wt. %, or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, and <NUM> wt. The second stream <NUM>, <NUM>, <NUM>, <NUM>, <NUM> can contain less than <NUM> wt. % to sulfur. In some aspects the second stream <NUM>, <NUM>, <NUM>, <NUM>, <NUM> can contain <NUM> wt. % to less than <NUM> wt. % or less than any one of, equal to any one of, or between any two <NUM> wt. %, <NUM> wt. %, <NUM> wt. % <NUM> wt. %, <NUM> wt. % <NUM> wt. %, <NUM> wt. % <NUM> wt. %, <NUM> wt. % <NUM> wt. %, <NUM> wt. % and <NUM> wt. % of sulfur. The sulfur in the second stream <NUM>, <NUM>, <NUM>, <NUM>, <NUM> can be present as organosulfur compounds. In some aspects, the iso-pentane of the second stream can be used as solvents, blend stock for gasoline, or blend stock for MTBE, or any combination thereof.

The third stream <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, 316a, 316b, 416a, 416b, 516a, 516b, can contain <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, and <NUM> wt. % of n-pentane; and/or <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, and <NUM> wt. %, % of neo-pentane. In some aspects, the third stream <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, 316a, 316b, 416a, 416b, 516a, 516b can further contain hexanes.

The fourth stream <NUM>, <NUM>, <NUM>, <NUM>, <NUM> can contain <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, and <NUM> wt. % of iso-pentane, <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, and <NUM> wt. % of n-pentane and <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, and <NUM> wt. %, of neo-pentane. In some aspects, the fourth stream <NUM>, <NUM>, <NUM> can further contain <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, and <NUM> wt. % of iso-butane, <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, and <NUM> wt. % of n-butane.

The fifth stream <NUM>, <NUM>, <NUM>, can include <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. % and <NUM> wt. % of n-butane.

The seventh stream <NUM> can contain (<NUM>) <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %,and <NUM> wt. % of isopentane; (<NUM>) <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, and <NUM> wt. % of n-pentane; (<NUM>) <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, and <NUM> wt. %, of neo-pentane; or (<NUM>) <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, and <NUM> wt. %, of n-butane; or any combination thereof.

The feed stream <NUM>, <NUM>, <NUM>, can contain <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, and <NUM> wt. % of n-butane. In some aspects, the feed stream <NUM>, <NUM>, <NUM> can further contain (<NUM>) <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, and <NUM> wt. % of iso-butane; (<NUM>) <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. % and <NUM> wt. % of iso-pentane; (<NUM>) <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. % <NUM> wt. %, <NUM> wt. % and <NUM> wt. % of n-pentane; or (<NUM>) <NUM> wt. % to <NUM> wt. % or at least any one of, equal to any one of, or between any two of <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. %, <NUM> wt. % and <NUM> wt. % of neo-pentane or any combination thereof.

Generally, in the separation column <NUM>, <NUM>, <NUM>, <NUM>, <NUM> iso-pentane can be separated from other hydrocarbons, such as n-pentane, neo-pentane, and n-butane. In some aspects, the separation column <NUM>, <NUM>, <NUM>, <NUM>, <NUM> can be a distillation column. In some aspects, the separation column <NUM>, <NUM>, <NUM>, <NUM>, <NUM> can be a deisopentanizer column. In some aspects, the separation column <NUM>, <NUM>, <NUM>, <NUM>, <NUM> operation condition during the separation of the first stream <NUM>, <NUM>, <NUM>, <NUM>, <NUM> can include (<NUM>) an overhead boiling range temperature of <NUM> to <NUM> , or at least any one of, equal to any one of, or between any two of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>; (<NUM>) a reboiler range of <NUM> to <NUM> , or at least any one of, equal to any one of, or between any two of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>; (<NUM>) an operation gauge pressure of <NUM> bar to <NUM> bar or at least any one of, equal to any one of, or between any two of <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, and <NUM> bar; or (<NUM>) an overhead reflux to feed ratio of <NUM> to <NUM> or at least any one of, equal to any one of, or between any two of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> or any combination thereof. In some aspects, the separation column <NUM>, <NUM>, <NUM>, <NUM>, <NUM> can include <NUM> to <NUM> or at least any one of, equal to any one of, or between any two of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> of trays. The second stream <NUM>, <NUM>, <NUM>, <NUM>, <NUM> can be obtained as a side stream from the separation column <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. The third stream <NUM> can be obtained as a bottom stream from the separation column <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. The fifth stream <NUM>, <NUM> and <NUM> can be obtained as a top stream from the from the separation column <NUM>, <NUM>, <NUM>.

Generally, in the butane isomerization unit <NUM>, <NUM>, <NUM>, <NUM>, <NUM> n-butane can be isomerized to iso-butane and n-pentane and/or neo-pentane can be isomerized to iso-pentane. In some aspects, the butane isomerization unit <NUM>, <NUM>, <NUM>, <NUM>, <NUM> can be an butane isomerization unit used for a butane isomerization process, such as process for preparing iso-butane from n-butane. The butane isomerization unit <NUM>, <NUM>, <NUM>, <NUM>, <NUM> operation condition to obtain the fourth stream can include (<NUM>) a temperature of <NUM> to <NUM> or at least any one of, equal to any one of, or between any two of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>; (<NUM>) a pressure of <NUM> bar to <NUM> bar or at least any one of, equal to any one of, or between any two of <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar and <NUM> bar; (<NUM>) a WHSV of <NUM>-<NUM> to <NUM>-<NUM> or at least any one of, equal to any one of, or between any two of <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> or any combination thereof. In some aspects, temperature at an inlet for the streams <NUM>, 216c, 316c, <NUM>, <NUM> to the butane isomerization unit can be <NUM> to <NUM> and temperature at the butane isomerization unit can be raised to about <NUM> to <NUM>, start of the run (SOR) to end of run (EOR).

In the desulfurization unit <NUM>, <NUM>, <NUM>, <NUM> hydrocarbons and/or hydrocarbons streams can be desulfurized. The desulfurizing process can include absorption and removing of sulfur containing compounds from the streams <NUM>, 316a, 416a, <NUM>, 516a, <NUM> by an adsorbent. In some aspects, the adsorbent can be zeolite 13X and/or activated charcoal. In some aspects, the desulfurization unit <NUM>, <NUM>, <NUM>, <NUM> can contain fixed beds containing zeolite 13X molecular sieve and/or an activated charcoal and the desulfurization process can include passing the streams <NUM>, 316a, 416a, <NUM>, 516a, <NUM> over and/or through the fixed bed at an ambient temperature or/and a pressure of <NUM> to <NUM> bar, or at least any one of, equal to any one of, or between any two of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> bar and <NUM> bar. A spent adsorbent can be formed by absorption of the sulfur containing compounds by the adsorbent. In some aspects, the adsorbent can be regenerated from the spent adsorbent. In some aspects, the regeneration process can include passing a gaseous stream containing N<NUM>, H<NUM> and/or sulfur free isobutane over and/or through a bed containing spent 13X and/or spent activated charcoal at a temperature <NUM> to <NUM> and/or a pressure <NUM> bar to <NUM> bar, <NUM> bar to <NUM> bar or <NUM> bar to <NUM> bar. In some aspects, the system <NUM>, <NUM>, <NUM>, <NUM> can include multiple desulfurization units (not shown). The desulfurization in an online desulfurization unit and regeneration in an offline second desulfurization unit can be performed simultaneously. At a point when regeneration of the adsorbent in the desulfurization unit becomes necessary, the online desulfurization unit can be taken offline for adsorbent regeneration and offline second desulfurization unit with regenerated adsorbent can be brought online for desulfurization. This arrangement provides a process for continuous desulfurization, as well as adsorbent regeneration. In some aspects, the desulfurization unit <NUM>, <NUM>, <NUM>, <NUM> can include a sulfur removal drier. In some aspects, the feed stream <NUM>, <NUM> can further contain <NUM> to <NUM> ppm or <NUM> to <NUM> ppm of sulfur containing compounds. The some aspects, the sulfur containing compounds can be H<NUM>S, mercaptans such as methyl, ethyl, and propyl mercaptans, carbonyl sulfide, di methyl di sulfide, di ethyl di sulfide, di methyl sulfide, di ethyl sulfide, or any combination thereof. In some aspects, after the desulfurization process, sulfur containing compounds content in the streams 216c, 316c, <NUM>, <NUM> exiting the desulfurization unit <NUM>, <NUM>, <NUM>, <NUM> can be less than <NUM> ppm, or less than <NUM> ppm, such as <NUM> to <NUM> ppm or <NUM> ppm to <NUM> ppm or <NUM> ppm to <NUM> ppm.

In some aspects, the DIB unit <NUM>, <NUM>, <NUM>, <NUM>, <NUM> can include a distillation column. In some particular aspect, the distillation column of the DIB unit <NUM>, <NUM>, <NUM>, <NUM>, <NUM> can be a DIB column. Generally, the DIB column can separate iso-butane, n-butane, and pentanes. In some aspects, the DIB column operation condition during production of the first stream <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and/or seventh stream <NUM> can include (<NUM>) an temperature of <NUM> to <NUM> , or at least any one of, equal to any one of, or between any two of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>; (<NUM>) a reboiler range of <NUM> to <NUM> , or at least any one of, equal to any one of, or between any two of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>; (<NUM>) an operation gauge pressure of <NUM> bar to <NUM> bar or at least any one of, equal to any one of, or between any two of <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, <NUM> bar, and <NUM> bar; or (<NUM>) an overhead reflux to feed ratio of <NUM> to <NUM> or at least any one of, equal to any one of, or between any two of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> or any combination thereof. In some aspects, the DIB column can include <NUM> to <NUM> or at least any one of, equal to any one of, or between any two of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> of trays.

In <FIG> the reactors, units and/or zones can include one or more heating and/or cooling devices (e.g., insulation, electrical heaters, jacketed heat exchangers in the wall) and/or controllers (e.g., computers, flow valves, automated values, etc.) that can be used to control the reaction temperature and pressure of the reaction mixture. While only one unit or zone is shown, it should be understood that multiple reactors or zones can be housed in one unit or a plurality of reactors housed in one heat transfer unit. In some aspects, the reactor can be a fixed bed reactor, moving bed, trickle-bed reactor, rotating bed reactor, slurry reactors or fluidized bed reactor.

The present invention will be described in greater detail by way of specific examples. The following examples are offered for illustrative purposes only, and are not intended to limit the invention in any manner. Those of skill in the art will readily recognize a variety of noncritical parameters which can be changed or modified to yield essentially the same results.

A pentanes stream from a DIB unit was processed according to the Example of <FIG>. A feed stream containing methane, ethane, propane, n-butane, iso-butane, n-pentane, iso-pentane, and neo-pentane was desulfurized. The resulting desulfurized stream was then fed to a butane isomerization unit. The resulting stream from the butane isomerization unit was fed to a DIB column. The DIB column used was a sieve column with multiple downcomers designed for high liquid loading over the weir, (<NUM> - <NUM> gpm/cm [<NUM>-<NUM> gpm/inch] weir length). A pentanes streams was obtained as a bottom stream of the DIB column. The pentanes stream was fed to a deisopentanizer column. The deisopentanizer column used was a single pas sieve tray column with a side draw fitting.

An iso-pentane containing stream, a n-pentane and neo-pentane containing stream, and a n-butane containing stream was obtained from the deisopentanizer column. A portion of the n-pentane and neo-pentane containing stream was combined with the feed stream, was desulfurized and was then fed to the butane isomerization unit. 13X molecular sieve was used desulfurization. Desulfurization was performed at <NUM> to <NUM> and <NUM> to <NUM> bar. Additional iso-pentane was produced in the butane isomerization unit from the n-pentane and/or neo-pentane. Composition of the different streams are provided in table <NUM>.

Claim 1:
A method for processing pentanes obtained from a de-isobutanizer (DIB) unit, the method comprising:
(a) separating a first stream comprising pentanes in a separation column to obtain a second stream comprising iso-pentane and a third stream comprising n-pentane and neo-pentane; and
(b) subjecting the third stream to a butane isomerization unit producing a fourth stream comprising iso-pentane, n-pentane, and neo-pentane.