Patent Description:
The present disclosure generally relates to chemical processing, and more specifically, to reactor designs and systems utilized in reactions to form light olefins.

Light olefins may be utilized as base materials to produce many types of goods and materials. For example, ethylene may be utilized to manufacture polyethylene, ethylene chloride, or ethylene oxides. Such products may be utilized in product packaging, construction, textiles, etc. Thus, there is an industry demand for light olefins, such as ethylene, propylene, and butene. However, most light olefins must be produced by different reaction processes based on the given chemical feed stream, which may be a product stream from a crude oil refining operation.

There is a continued need for processes and apparatuses which are suitable for producing light olefins from varying feed streams. Light olefins may be produced from a variety of feed stream by utilizing different catalysts. For example, light olefins may be produced by at least dehydrogenation reactions, cracking reactions, dehydration reactions, and methanol-to-olefin reactions. However, according to various embodiments, these reaction types may utilize different feed streams which are subsequently reacted to form the light olefins. Non-limiting examples include utilizing a dehydrogenation reaction that may utilize a gallium and/or platinum catalyst to react a feed stream comprising one or more of ethane, propane, n-butane, and i-butane; a cracking reaction that may utilize a zeolite catalyst to react a feed stream comprising one or more of naphtha, n-butane, or i-butane; a dehydration reaction that may utilize an acid catalyst (such as alumina or zeolite) to react a feed stream comprising one or more of ethanol, propanol, or butanol; and a methanol-to-olefin reaction that may utilize a zeolite catalyst (such as SAPO-<NUM>) to react a feed stream comprising methanol.

While numerous reaction types, as described above, may be utilized to produce light olefins (e.g., dehydrogenation, cracking, dehydration, and methanol-to-olefin), a need exists for a flexible reactor system which can efficiently handle two or more of these types of reactions. For example, a flexible reactor system which can handle two or more of dehydrogenation, cracking, dehydration, and methanol-to-olefin reactions allows for the system to utilize varying feeds as they become available or change price without the added capital costs of having different reactor systems to treat each feedstock.

<NPL>) discloses the use of micro-pulse reactors for preparing olefins involving cracking reactions or dehydrogenation reactions.

Described herein, according to one or more embodiments, are methods for processing different chemical feed streams in a single reactor to form light olefins. The reactor designs described herein may be operable for processing at least two different feed steams at different times, utilizing different types of reactions for each feed stream, to form light olefins. Such methods and systems may reduce costs for producing light olefins by allowing for the selection of a feed stream and reaction type which is most economical while not requiring the added capital costs of designing and constructing a completely separate chemical reactor system.

The present invention is directed to a method for processing chemical streams, the method comprising:.

According to another embodiment, the first reaction may be a cracking reaction and the second reaction may be a dehydrogenation reaction.

According to yet another embodiment, the first reaction may be a dehydrogenation reaction and the second reaction may be a cracking reaction.

It is to be understood that both the foregoing brief summary and the following detailed description present embodiments of the technology, and are intended to provide an overview or framework for understanding the nature and character of the technology as it is claimed. The accompanying drawings are included to provide a further understanding of the technology, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments and, together with the description, serve to explain the principles and operations of the technology. Additionally, the drawings and descriptions are meant to be merely illustrative, and are not intended to limit the scope of the claims in any manner.

Additional features and advantages of the technology disclosed herein will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the technology as described herein, including the detailed description which follows, the claims, as well as the appended drawings.

It should be understood that the drawings are schematic in nature, and do not include some components of a reactor system commonly employed in the art, such as, without limitation, temperature transmitters, pressure transmitters, flow meters, pumps, valves, and the like. It would be known that these components are within the scope of the present embodiments disclosed. However, operational components, such as those described in the present disclosure, may be added to the embodiments described in this disclosure.

Embodiments related to methods for processing chemical streams to form light olefins are disclosed herein. In various embodiments, two different chemical feed streams may be processed sequentially in a single flexible reactor system, where each feed stream has a different composition. Since each feed stream has a different composition, different reaction types may be required to form light olefins from the respective feed streams, and different catalysts may be utilized in each type of reaction. As described herein, a "type" of reaction refers to a class of reaction that imparts a particular change on some or all of the components of a feed stream. For example, one type of reaction described herein is a dehydrogenation reaction. Other example reaction types include cracking, dehydration, and methanol-to-olefin reactions. Additionally, as described herein, the "first feed stream" refers to an initial feed stream which is processed in a reactor, and the "second feed stream" refers to a sequential feed stream (i.e., a stream which is processed chronologically after the first feed stream) which is processed in the same reactor. For example, a first feed stream may be processed in the reactor, and then, later, a second feed stream may be processed in the reactor following the removal of the first feed stream.

The first feed stream may be converted to light olefins by contact with a first catalyst, and the second feed stream may be converted to light olefins by a second catalyst. Additionally, in embodiments, the first feed stream may be processed by the first catalyst to form a first product stream, in what is referred to as the first reaction, and the second feed stream may be processed by the second catalyst to form a second product stream, in what is referred to as the second reaction. The first reaction of the first feed stream to form the first product stream may be referred to as the "first chemical process," and the second reaction of the second feed stream to form the second product stream may be referred to as the "second chemical process.

According to one or more embodiments, a method for processing chemical streams may include a step of operating the first chemical process involving the first reaction, stopping the first chemical process and removing the first catalyst from the reactor, and operating the second chemical process involving the second reaction. These steps may occur in chronological order as listed. According to one or more embodiments, the first reaction may be a dehydrogenation reaction, a cracking reaction, a dehydration reaction, or a methanol-to-olefin reaction, and the second reaction may be a dehydrogenation reaction, a cracking reaction, a dehydration reaction, or a methanol-to-olefin reaction. However, in embodiments, the first reaction and the second reaction are different types of reactions. Additionally, in one or more embodiments, the first catalyst and the second catalyst may have different compositions.

For example, if the first reaction is a dehydrogenation reaction, then the second reaction may be a cracking reaction, a dehydration reaction, or a methanol-to-olefin reaction, but not a dehydrogenation catalyst. In another embodiment, if the first reaction is a cracking reaction, then the second reaction may be a dehydrogenation reaction, a dehydration reaction, or a methanol-to-olefin reaction, but not a cracking catalyst. In another embodiment, if the first reaction is a dehydration reaction, then the second reaction may be a dehydrogenation reaction, a cracking reaction, or a methanol-to-olefin reaction, but not a dehydration catalyst. In another embodiment, if the first reaction is a methanol-to-olefin reaction, then the second reaction may be a dehydrogenation reaction, a cracking reaction, or a dehydration reaction, but not a methanol-to-olefin catalyst.

According to one or more embodiments, the first reaction or the second reaction may be a dehydrogenation reaction. According to such embodiments, the first feed stream or the second feed stream may comprise one or more of ethane, propane, n-butane, and i-butane. For example, if the first reaction is a dehydrogenation reaction, then the first feed stream may comprise one or more of ethane, propane, n-butane, and i-butane, and if the second reaction is a dehydrogenation reaction, then the second feed stream may comprise one or more of ethane, propane, n-butane, and i-butane. According to one or more embodiments, the first feed stream or the second feed stream may comprise at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. % or even at least <NUM> wt. % of ethane. In additional embodiments, the first feed stream or the second feed stream may comprise at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. % or even at least <NUM> wt. % of propane. In additional embodiments, the first feed stream or the second feed stream may comprise at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. % or even at least <NUM> wt. % of n-butane. In additional embodiments, the first feed stream or the second feed stream may comprise at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. % or even at least <NUM> wt. % of i-butane. In additional embodiments, the first feed stream or the second feed stream may comprise at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. % or even at least <NUM> wt. % of the sum of ethane, propane, n-butane, and i-butane.

In one or more embodiments, the dehydrogenation reaction may utilize gallium and/or platinum catalyst as a catalyst. In such embodiments, the first catalyst or the second catalyst may comprise a gallium and/or platinum catalyst. For example, if the first reaction is a dehydrogenation reaction, then the first catalyst may comprise gallium and/or platinum catalyst, and if the second reaction is a dehydrogenation reaction, then the second catalyst may comprise gallium and/or platinum catalyst. As described herein, a gallium and/or platinum catalyst comprises gallium, platinum, or both. The gallium and/or platinum catalyst may be carried by an alumina or alumina silica support, and may optionally comprise potassium. Such gallium and/or platinum catalysts are disclosed in <CIT>. However, it should be understood that other suitable catalysts may be utilized to perform the dehydrogenation reaction.

According to one or more embodiments, the first reaction or the second reaction may be a cracking reaction. According to such embodiments, the first feed stream or the second feed stream may comprise one or more of naphtha, n-butane, or i-butane. For example, if the first reaction is a cracking reaction, then the first feed stream may comprise one or more of naphtha, n-butane, or i-butane, and if the second reaction is a cracking reaction, then the second feed stream may comprise one or more of naphtha, n-butane, or i-butane. According to one or more embodiments, the first feed stream or the second feed stream may comprise at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. % or even at least <NUM> wt. % of naphtha. In additional embodiments, the first feed stream or the second feed stream may comprise at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. % or even at least <NUM> wt. % of n-butane. In additional embodiments, the first feed stream or the second feed stream may comprise at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. % or even at least <NUM> wt. % of i-butane. In additional embodiments, the first feed stream or the second feed stream may comprise at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. % or even at least <NUM> wt. % of the sum of naphtha, n-butane, and i-butane.

In one or more embodiments, the cracking reaction may utilize one or more zeolites as a catalyst. In such embodiments, the first catalyst or the second catalyst may comprise one or more zeolites. For example, if the first reaction is a cracking reaction, then the first catalyst may comprise one or more zeolites, and if the second reaction is a cracking reaction, then the second catalyst may comprise one or more zeolites. In some embodiments, the one or more zeolites utilized in the cracking reaction may comprise a ZSM-<NUM> zeolite. However, it should be understood that other suitable catalysts may be utilized to perform the cracking reaction. For example, suitable catalysts that are commercially available may include Intercat Super Z Excel or Intercat Super Z Exceed. In additional embodiments, the cracking catalyst may comprise, in addition to a catalytically active material, platinum. For example, the cracking catalyst may include from <NUM> wt. % to <NUM> wt. % of platinum. The platinum may be sprayed on as platinum nitrate and calcined at an elevated temperature, such as around <NUM>. Without being bound by theory, it is believed that the addition of platinum to the catalyst may allow for easier combustion of supplemental fuels, such as methane.

According to one or more embodiments, the first reaction or the second reaction may be a dehydration reaction. According to such embodiments, the first feed stream or the second feed stream may comprise one or more of ethanol, propanol, or butanol. For example, if the first reaction is a dehydration reaction, then the first feed stream may comprise one or more of ethanol, propanol, or butanol, and if the second reaction is a dehydration reaction, then the second feed stream may comprise one or more of ethanol, propanol, or butanol. According to one or more embodiments, the first feed stream or the second feed stream may comprise at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. % or even at least <NUM> wt. % of ethanol. In additional embodiments, the first feed stream or the second feed stream may comprise at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. % or even at least <NUM> wt. % of propanol. In additional embodiments, the first feed stream or the second feed stream may comprise at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. % or even at least <NUM> wt. % of butanol. In additional embodiments, the first feed stream or the second feed stream may comprise at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. % or even at least <NUM> wt. % of the sum of ethanol, propanol, and butanol.

In one or more embodiments, the dehydration reaction may utilize one or more acid catalysts. In such embodiments, the first catalyst or the second catalyst may comprise one or more acid catalysts. For example, if the first reaction is a dehydration reaction, then the first catalyst may comprise one or more acid catalysts, and if the second reaction is a dehydration reaction, then the second catalyst may comprise one or more acid catalysts. In some embodiments, the one or more acid catalysts utilized in the dehydration reaction may comprise a zeolite (such as ZSM-<NUM> zeolite), alumina, amorphous aluminosilicate, acid clay, or combinations thereof. For example, commercially available alumina catalysts which may be suitable, according to one or more embodiments, include SynDol (available from Scientific Design Company), V200 (available from UOP), or P200 (available from Sasol). Commercially available zeolite catalysts which may be suitable include CBV <NUM>, CBV <NUM> (each available from Zeolyst). Commercially available amorphous aluminosilicate catalysts which may be suitable include silica-alumina catalyst support, grade <NUM> (available from Sigma Aldrich). However, it should be understood that other suitable catalysts may be utilized to perform the dehydration reaction.

According to one or more embodiments, the first reaction or the second reaction may be a methanol-to-olefin reaction. According to such embodiments, the first feed stream or the second feed stream may comprise methanol. For example, if the first reaction is a methanol-to-olefin reaction, then the first feed stream may comprise methanol, and if the second reaction is a methanol-to-olefin reaction, then the second feed stream may comprise methanol. According to one or more embodiments, the first feed stream or the second feed stream may comprise at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. %, at least <NUM> wt. % or even at least <NUM> wt. % of methanol.

In one or more embodiments, the methanol-to-olefin reaction may utilize one or more zeolites as a catalyst. In such embodiments, the first catalyst or the second catalyst may comprise one or more zeolites. For example, if the first reaction is a methanol-to-olefin reaction, then the first catalyst may comprise one or more zeolites, and if the second reaction is a methanol-to-olefin reaction, then the second catalyst may comprise one or more zeolites. In some embodiments, the one or more zeolites utilized in the methanol-to-olefin reaction may comprise a one or more of a ZSM-<NUM> zeolite or a SAPO-<NUM> zeolite. However, it should be understood that other suitable catalysts may be utilized to perform the methanol-to-olefin reaction.

According to various embodiments, the first product stream and the second product stream may each comprise light olefins. As described herein, "light olefins" refers to one or more of ethylene, propylene, or butene. As described herein, butene many include any isomer of butene, such as α-butylene, cis-β-butylene, trans-β-butylene, and isobutylene.

In one or more embodiments, the operating of the first chemical process may include passing the first product stream out of the reactor. Additionally, in one or more embodiments, the operating of the second chemical process may include passing the second product stream out of the reactor. In one embodiment, the first product stream may comprise at least <NUM> wt. % light olefins. For example, the first product stream may comprise at least <NUM> wt. % light olefins, at least <NUM> wt. % light olefins, at least <NUM> wt. % light olefins, at least <NUM> wt. % light olefins, at least <NUM> wt. % light olefins, or even at least <NUM> wt. % light olefins. In another embodiment, the second product stream may comprise at least <NUM> wt. % light olefins. For example, the second product stream may comprise at least <NUM> wt. % light olefins, at least <NUM> wt. % light olefins, at least <NUM> wt. % light olefins, at least <NUM> wt. % light olefins, at least <NUM> wt. % light olefins, or even at least <NUM> wt. % light olefins.

Now referring to <FIG>, an example reactor system <NUM> which may be suitable for use with the methods described herein is schematically depicted. It should be understood that, in some embodiments, the first chemical process and the second chemical process may be operated sequentially in the reactor system <NUM>. However, with reference to the description of <FIG>, it should be understood that any description of a catalyst, feed stream, or product stream, may equally apply to the first chemical process or the second chemical process. For example, a "catalyst" in <FIG> may refer to the first catalyst or the second catalyst, the "feed stream" may refer to the first feed stream or second feed stream, and the "product stream" may refer to the first product stream or the second product stream.

Now referring to <FIG>, an example reactor system <NUM> which may be suitable for use with the methods described herein is schematically depicted, and it should be understood that other reactor system configurations may be suitable for the methods described herein. The reactor system <NUM> generally comprises multiple system components, such as a reactor portion <NUM> and/or a catalyst processing portion <NUM>. As used herein in the context of <FIG>, the reactor portion <NUM> generally refers to the portion of a reactor system <NUM> in which the major process reaction takes place, such as a dehydrogenation reaction, a cracking reaction, a dehydration reaction, or a methanol-to-olefin reaction to form light olefins. The reactor portion <NUM> comprises a reactor <NUM> which may include a downstream reactor section <NUM> and an upstream reactor section <NUM>. According to one or more embodiments, as depicted in <FIG>, the reactor portion <NUM> may additionally include a catalyst separation section <NUM> which serves to separate the catalyst from the chemical products formed in the reactor <NUM>. Also, as used herein, the catalyst processing portion <NUM> generally refers to the portion of a reactor system <NUM> where the catalyst is in some way processed, such as by combustion. The catalyst processing portion <NUM> may comprise a combustor <NUM> and a riser <NUM>, and may optionally comprise a catalyst separation section <NUM>. In some embodiments, the catalyst may be regenerated by burning off contaminants like coke in the catalyst processing portion <NUM>. In additional embodiments, the catalyst may be heated in the catalyst processing portion <NUM>. A supplemental fuel may be utilized to heat the catalyst in the catalyst processing portion <NUM> if coke or another combustible material is not formed on the catalyst, or an amount of coke formed on the catalyst is not sufficient to burn off to heat the catalyst to a desired temperature. In one or more embodiments, the catalyst separation section <NUM> may be in fluid communication with the combustor <NUM> (e.g., via standpipe <NUM>) and the catalyst separation section <NUM> may be in fluid communication with the upstream reactor section <NUM> (e.g., via standpipe <NUM> and transport riser <NUM>).

As described with respect to <FIG>, the feed stream may enter transport riser <NUM>, and the product stream may exit the reactor system <NUM> via pipe <NUM>. According to one or more embodiments, the reactor system <NUM> may be operated by feeding a chemical feed (e.g., in a feed stream) and a fluidized catalyst into the upstream reactor section <NUM>. The chemical feed contacts the catalyst in the upstream reactor section <NUM>, and each flow upwardly into and through the downstream reactor section <NUM> to produce a chemical product. The chemical product and the catalyst may be passed out of the downstream reactor section <NUM> to a separation device <NUM> in the catalyst separation section <NUM>, where the catalyst is separated from the chemical product, which is transported out of the catalyst separation section <NUM>. The separated catalyst is passed from the catalyst separation section <NUM> to the combustor <NUM>. In the combustor <NUM>, the catalyst may be processed by, for example, combustion. For example, and without limitation, the catalyst may be de-coked and/or supplemental fuel may be combusted to heat the catalyst. The catalyst is then passed out of the combustor <NUM> and through the riser <NUM> to a riser termination separator <NUM>, where the gas and solid components from the riser <NUM> are at least partially separated. The vapor and remaining solids are transported to a secondary separation device <NUM> in the catalyst separation section <NUM> where the remaining catalyst is separated from the gases from the catalyst processing (e.g., gases emitted by combustion of spent catalyst or supplemental fuel). The separated catalyst is then passed from the catalyst separation section <NUM> to the upstream reactor section <NUM> via standpipe <NUM> and transport riser <NUM>, where it is further utilized in a catalytic reaction. Thus, the catalyst, in operation, may cycle between the reactor portion <NUM> and the catalyst processing portion <NUM>. In general, the processed chemical streams, including the feed streams and product streams may be gaseous, and the catalyst may be fluidized particulate solid.

According to one or more embodiments described herein, the reactor portion <NUM> may comprise an upstream reactor section <NUM>, a transition section <NUM>, and a downstream reactor section <NUM>, such as a riser. The transition section <NUM> may connect the upstream reactor section <NUM> with the downstream reactor section <NUM>. According to one or more embodiments, the upstream reactor section <NUM> and the downstream reactor section <NUM> may each have a substantially constant cross-section area, while the transition section <NUM> may be tapered and does not have a constant cross-sectional area. As described herein, unless otherwise explicitly stated, the "cross-sectional area" refers to the area of the cross section of a portion of the reactor part in a plane substantially orthogonal to the direction of general flow of reactants and/or products. For example, in <FIG>, the cross sectional area of the upstream reactor section <NUM>, the transition section <NUM>, and the downstream reactor section <NUM> is in the direction of a plane defined by the horizontal direction and the direction into the page (orthogonal to the direction of fluid motion, i.e., vertically upward in <FIG>).

As depicted in <FIG>, the upstream reactor section <NUM> may be positioned below the downstream reactor section <NUM>. Such a configuration may be referred to as an upflow configuration in the reactor <NUM>.

As described herein, the upstream reactor section <NUM> may include a vessel, drum, barrel, vat, or other container suitable for a given chemical reaction. In one or more embodiments, the upstream reactor section <NUM> may be generally cylindrical in shape (i.e., having a substantially circular cross-sectional shape), or may alternately be non-cylindrically shaped, such as prism shaped with cross-sectional shapes of triangles, rectangles, pentagons, hexagons, octagons, ovals, or other polygons or curved closed shapes, or combinations thereof. The upstream reactor section <NUM>, as used throughout this disclosure, may generally include a metallic frame, and may additionally include refractory linings or other materials utilized to protect the metallic frame and/or control process conditions. As depicted in <FIG>, the upstream reactor section <NUM> may include a lower reactor portion catalyst inlet port <NUM> defining the connection of transport riser <NUM> to the upstream reactor section <NUM>.

The upstream reactor section <NUM> may be connected to a transport riser <NUM> which, in operation, may provide processed catalyst and/or reactant chemicals in a feed stream to the reactor portion <NUM>. The processed catalyst and/or reactant chemicals may be mixed with a feed distributor <NUM> housed in the upstream reactor section <NUM>. The catalyst entering the upstream reactor section <NUM> via transport riser <NUM> may be passed through standpipe <NUM> to a transport riser <NUM>, thus arriving from the catalyst processing portion <NUM>. In some embodiments, catalyst may come directly from the catalyst separation section <NUM> via standpipe <NUM> and into a transport riser <NUM>, where it enters the upstream reactor section <NUM>. This catalyst may be slightly deactivated, but may still, in some embodiments, be suitable for reaction in the upstream reactor section <NUM>. As used herein, "deactivated" may refer to a catalyst which is contaminated with a substance such as coke, or is cooler in temperature than desired. Regeneration may remove the contaminant such as coke, raise the temperature of the catalyst, or both.

In one or more embodiments, the feed distributor <NUM> may be operable to dispense the first feed stream and the second feed stream at all shroud distributor velocities from <NUM> ft/s to <NUM> ft/s (<NUM>/s to <NUM>/s). In such embodiments, various feed streams may be utilized while maintaining the desired reactor characteristics, such as operating as a fast fluidized, turbulent, or bubbling bed reactor in the upstream reactor section <NUM> and as a dilute phase riser reactor in the downstream reactor section <NUM>. For example, according to one or more embodiments, a shroud distributor velocity of about <NUM> ft/s (<NUM>/s) may be utilized in the upstream reactor section <NUM> for naphtha feeds, while a shroud distributor velocity of about <NUM> ft/s (<NUM>/s) may be utilized in the upstream reactor section <NUM> for propane feeds. In additional embodiments, some orifices could be closed in the reactor <NUM> when naphtha is utilized as a feed stream. The "shroud distributor velocity" refers the velocity at which the gas exits the distributor, sometimes through a shroud. For example, suitable distributors are disclosed in <CIT>.

Still referring to <FIG>, the reactor portion <NUM> may comprise a downstream reactor section <NUM> which acts to transport reactants, products, and/or catalyst from the upstream reactor section <NUM> to the catalyst separation section <NUM>. In one or more embodiments, the downstream reactor section <NUM> may be generally cylindrical in shape (i.e., having a substantially circular cross-sectional shape), or may alternately be non-cylindrically shaped, such as prism shaped with cross-sectional shape of triangles, rectangles, pentagons, hexagons, octagons, ovals, or other polygons or curved closed shapes, or combinations thereof. The downstream reactor section <NUM>, as used throughout this disclosure, may generally include a metallic frame, and may additionally include refractory linings or other materials utilized to protect the metallic frame and/or control process conditions.

According to some embodiments, the downstream reactor section <NUM> may include an external riser section <NUM> and an internal riser section <NUM>. As used herein, an "external riser section" refers to the portion of the riser that is outside of the catalyst separation section, and an "internal riser section" refers to the portion of the riser that is within the catalyst separation section. For example, in the embodiment depicted in <FIG>, the internal riser section <NUM> of the reactor portion <NUM> may be positioned within the catalyst separation section <NUM>, while the external riser section <NUM> is positioned outside of the catalyst separation section <NUM>.

As depicted in <FIG>, the upstream reactor section <NUM> may be connected to the downstream reactor section <NUM> via the transition section <NUM>. The upstream reactor section <NUM> may generally comprise a greater cross-sectional area than the downstream reactor section <NUM>. The transition section <NUM> may be tapered from the size of the cross-section of the upstream reactor section <NUM> to the size of the cross-section of the downstream reactor section <NUM> such that the transition section <NUM> projects inwardly from the upstream reactor section <NUM> to the downstream reactor section <NUM>.

In some embodiments, such as those where the upstream reactor section <NUM> and the downstream reactor section <NUM> have similar cross-sectional shapes, the transition section <NUM> may be shaped as a frustum. For example, for an embodiment of a reactor portion <NUM> comprising a cylindrical upstream reactor section <NUM> and cylindrical downstream reactor section <NUM>, the transition section <NUM> may be shaped as a conical frustum. However, it should be understood that a wide variety of upstream reactor section <NUM> shapes are contemplated herein which connect various shapes and sizes of upstream reactor sections <NUM> and downstream reactor sections <NUM>.

The upstream reactor section <NUM> has an average cross-sectional area that is at least <NUM>% of the average cross-sectional area of the downstream reactor section <NUM>. As described herein, an "average cross-sectional area" refers to the mean of the cross-sectional areas for a given system component or section such as the upstream reactor section <NUM> or the downstream reactor section <NUM>. If the system component or section has a substantially constant cross-sectional area, such as the cylindrical shapes of the depicted upstream reactor section <NUM> or the downstream reactor section <NUM>, then the cross-sectional area at any point is about equal to the average cross-sectional area.

According to one or more embodiments, the upstream reactor section <NUM> may have an average cross-sectional area that is at least <NUM>%, at least <NUM>%, at least <NUM>%, at least <NUM>%, at least <NUM>%, at least <NUM>%, at least <NUM>%, at least <NUM>% or even at least <NUM>% of the average cross-sectional area of the downstream reactor section <NUM>.

In the present invention, based on the shape, size, and other processing conditions such as temperature and pressure in the upstream reactor section <NUM> and the downstream reactor section <NUM>, the upstream reactor section <NUM> operates in a manner that is or approaches isothermal, namely in a fast fluidized, turbulent, or bubbling bed reactor, while the downstream reactor section <NUM> operates in more of a plug flow manner, namely in a dilute phase riser reactor. For example, the reactor <NUM> of <FIG> may comprise a upstream reactor section <NUM> operating as a fast fluidized, turbulent, or bubbling bed reactor and a downstream reactor section <NUM> operating as a dilute phase riser reactor, with the result that the average catalyst and gas flow moves concurrently upward. As the term is used herein, "average flow" refers to the net flow, i.e., the total upward flow minus the retrograde or reverse flow, as is typical of the behavior of fluidized particles in general. As described herein, a "fast fluidized" reactor may refer to a reactor utilizing a fluidization regime wherein the superficial velocity of the gas phase is greater than the choking velocity and may be semi-dense in operation. As described herein, a "turbulent" reactor may refer to a fluidization regime where the superficial velocity of less than the choking velocity and is more dense than the fast fluidized regime. As described herein, a "bubbling bed" reactor may refer to a fluidization regime wherein well defined bubbles in a highly dense bed are present in two distinct phases. The "choking velocity" refers to the minimum velocity required to maintain solids in the dilute-phase mode in a vertical conveying line. As described herein, a "dilute phase riser" may refer to a riser reactor operating at transport velocity, where the gas and catalyst have about the same velocity in a dilute phase.

In one or more embodiments, the pressure in the reactor <NUM> may range from <NUM> to <NUM> pounds per square inch absolute (psia, from about <NUM> kilopascals, kPa, to about <NUM> kPa), but in some embodiments, a narrower selected range, such as from <NUM> psia to <NUM> psia, (from about <NUM> kPa to about <NUM> kPa), may be employed. For example, the pressure may be from <NUM> psia to <NUM> psia (from about <NUM> kPa to about <NUM> kPa), from <NUM> psia to <NUM> psia (from about <NUM> kPa to about <NUM> kPa), or from <NUM> psia to <NUM> psia (from about <NUM> kPa to about <NUM> kPa). Unit conversions from standard (non-SI) to metric (SI) expressions herein include "about" to indicate rounding that may be present in the metric (SI) expressions as a result of conversions.

In additional embodiments, the weight hourly space velocity (WHSV) for the disclosed process may range from <NUM> pound (lb) to <NUM> lb (<NUM> grams to <NUM> kilograms) of chemical feed per hour (h) per lb of catalyst in the reactor (lb feed/h/lb catalyst). For example, where a reactor comprises an upstream reactor section <NUM> that operates as a fast fluidized, turbulent, or bubbling bed reactor and a downstream reactor section <NUM> that operates as a riser reactor, the superficial gas velocity may range therein from <NUM> feet per second (ft/s, about <NUM> meters per second, m/s) to <NUM> ft/s (about <NUM>/s), such as from <NUM> ft/s (about <NUM>/s) to <NUM> ft/s (about <NUM>/s), in the upstream reactor section <NUM>, and from <NUM> ft/s (about <NUM>/s) to <NUM> ft/s (about <NUM>/s) in the downstream reactor section <NUM>. In additional embodiments, a reactor configuration that is fully of a riser type may operate at a single high superficial gas velocity, for example, in some embodiments at least <NUM> ft/s (about <NUM>/s) throughout.

In additional embodiments, the ratio of catalyst to feed stream in the reactor <NUM> may range from <NUM> to <NUM> on a weight to weight (w/w) basis. In some embodiments, the ratio may range from <NUM> to <NUM>, such as from <NUM> to <NUM>, or from <NUM> to <NUM>.

In additional embodiments, the catalyst flux may be from <NUM> pound per square foot-second (lb/ft<NUM>-s) (about <NUM>/m<NUM>-s) to <NUM> lb/ft<NUM>-s (to about <NUM>/m2-s) in the upstream reactor section <NUM>, and from <NUM> lb/ft<NUM>-s (about <NUM>/m2-s) to <NUM> lb/ft<NUM>-s (about <NUM>/m2-s) in the downstream reactor section <NUM>.

In operation, the catalyst may move upward through the downstream reactor section <NUM> (from the upstream reactor section <NUM>), and into the separation device <NUM>. The separated vapors may be removed from the reactor system <NUM> via a pipe <NUM> at a gas outlet port <NUM> of the catalyst separation section <NUM>. According to one or more embodiments, the separation device <NUM> may be a cyclonic separation system, which may include two or more stages of cyclonic separation. In embodiments where the separation device <NUM> comprises more than one cyclonic separation stages, the first separation device into which the fluidized stream enters is referred to a primary cyclonic separation device. The fluidized effluent from the primary cyclonic separation device may enter into a secondary cyclonic separation device for further separation. Primary cyclonic separation devices may include, for example, primary cyclones, and systems commercially available under the names VSS (commercially available from UOP), LD2 (commercially available from Stone and Webster), and RS2 (commercially available from Stone and Webster). Primary cyclones are described, for example, in <CIT>; <CIT>; and <CIT>. In some separation systems utilizing primary cyclones as the primary cyclonic separation device, one or more set of additional cyclones, e.g. secondary cyclones and tertiary cyclones, are employed for further separation of the catalyst from the product gas. It should be understood that any primary cyclonic separation device may be used in embodiments of the invention.

According to one or more embodiments, following separation from vapors in the separation device <NUM>, the catalyst may generally move through the stripper <NUM> to the catalyst outlet port <NUM> where the catalyst is transferred out of the reactor portion <NUM> via standpipe <NUM> and into the catalyst processing portion <NUM>. Optionally, the catalyst may also be transferred directly back into the upstream reactor section <NUM> via standpipe <NUM>. Alternatively, the catalyst may be premixed with processed catalyst in the transport riser <NUM>.

According to one or more embodiments, operating the first chemical process and/or second chemical process, such as in reactor system <NUM>, may comprise recycling the catalyst utilized in the first or second chemical process by passing the catalyst from the reactor <NUM> to a regeneration unit (such as the combustor <NUM> of the embodiment of <FIG>), processing the respective catalyst in the regeneration unit, and passing the first catalyst from the regeneration unit to the reactor <NUM>.

Referring now to the catalyst processing portion <NUM>, as depicted in <FIG>, the combustor <NUM> of the catalyst processing portion <NUM> may include one or more lower reactor section inlet ports <NUM> and may be in fluid communication with the riser <NUM>. The combustor <NUM> may be in fluid communication with the catalyst separation section <NUM> via standpipe <NUM>, which may supply spent catalyst from the reactor portion <NUM> to the catalyst processing portion <NUM> for regeneration. The combustor <NUM> may include an additional lower reactor section inlet port <NUM> where air inlet <NUM> connects to the combustor <NUM>. The air inlet <NUM> may supply reactive gases which may react with the spent catalyst or a supplemental fuel to at least partially regenerate the catalyst. For example, the catalyst may be coked following the reactions in the upstream reactor section <NUM>, and the coke may be removed from the catalyst (i.e., regenerating the catalyst) by a combustion reaction. For example, oxidizer (such as air) may be fed into the combustor <NUM> via the air inlet <NUM>. Alternatively or additionally, such as when coke is not formed on the catalyst, a supplemental fuel may be injected into the combustor <NUM>, which may be burned to heat the catalyst. Following combustion, the processed catalyst may be separated in the catalyst separation section <NUM> and delivered back into the reactor portion <NUM> via standpipe <NUM>.

According to additional embodiments, the reactor system <NUM> may be integrated into a chemical conversion system <NUM>, as depicted in <FIG>. The chemical conversion system <NUM> may include a reactor system <NUM> as previously described, as well as a thermal cracking unit <NUM>. System inlet stream <NUM> may bring feed materials to the reactor system <NUM>, such as one or more of ethane, propane, butane, naphtha, or methanol. In some embodiments, system inlet stream <NUM> may be the feed stream of the described methods for forming olefins. System stream <NUM> may be produced by the reactor system <NUM>, which may be the product stream of the presently described methods for forming olefins.

According to one or more embodiments, the chemical conversion system <NUM> may optionally include an oxygenates removal section <NUM> to process system stream <NUM>. For example, an oxygenates removal section <NUM> may be utilized to remove one or more of methanol, water, or dimethyl ether from system stream <NUM> when a methanol-to-olefin reaction is utilized in reactor system <NUM>. It should be understood that the oxygenates removal section <NUM> may be bypassed for when oxygenates are not present in the process stream <NUM>, such as when dehydrogenation, cracking, or dehydration reactions are performed in the reactor system <NUM>. The oxygenates removal section <NUM> may be any suitable separation unit, such as a tower or absorber.

Additionally, system inlet stream <NUM> may provide ethane, naphtha, propane, butane, or combinations thereof, to the thermal cracking unit <NUM>. The thermal cracking unit <NUM> may include one or more furnaces. The system stream <NUM> formed by the thermal cracking unit <NUM> may be combined with system stream <NUM> to form system stream <NUM>, which may enter a compression unit <NUM>. The compression unit <NUM> may compress the contents of system stream <NUM> to form system stream <NUM>. The compression unit <NUM> may include one or more of a series of compressors, a caustic tower, and a dryer. System stream <NUM> may be processed in a product recovery unit <NUM>, which may recover light olefins such as ethene, butene, or propene from the chemical conversion system <NUM>. Product recovery unit <NUM> may include one or more distillation towers or other separation devices. System outlet streams <NUM>, <NUM>, <NUM> may include one or more chemical products, such as ethene, propene, or butene, or other non-olefin materials which may be sold or further processed. In some embodiments, recycle streams <NUM> and <NUM> may recycle portions of system stream <NUM> back to the reactor system <NUM> and/or the thermal cracking unit <NUM>, respectively. For example, recycle stream <NUM> may bring C4 hydrocarbons back to the reactor system <NUM>.

According to one or more embodiments, now referring to <FIG> and <FIG>, the reactor system may further comprise one or more of a feed vaporizer <NUM> or a quench tower <NUM>. The feed vaporizer may be upstream of the reactor portion <NUM> and the catalyst processing portion <NUM>, and the quench tower <NUM> may be downstream of the reactor portion <NUM> and the catalyst processing portion <NUM>. In such an embodiment, system stream <NUM> may provide feed materials to the reactor portion <NUM>, and system stream <NUM> may pass product materials to the quench tower <NUM>. In such an embodiment, the system stream <NUM> may constitute the feed stream and system stream <NUM> may constitute the product stream of the presently disclosed processes for forming olefins.

In one embodiment, the feed vaporizer <NUM> may vaporize the first feed stream and the second feed stream. In one or more embodiments, the feed vaporizer <NUM> may comprise one or more heat exchangers. As the first feed stream may be different from the second feed stream, the feed vaporizer <NUM> may be suitable for vaporizing both the first feed stream and the second feed stream. For example, the feed vaporizer <NUM> may be need to vaporize both relatively light feeds such as propane, medium feeds such as butane, or relatively heavy feeds such as naphtha. The feed vaporizer <NUM> may therefore be rated for vaporizing the heaviest feed contemplated, such as naphtha. For example, the feed vaporizer <NUM> may be a heat exchanger operable to utilize medium temperature quench water for vaporizing propane, operable to utilize hot quench water or low pressure steam to vaporize butane, and operable to utilize medium pressure steam to vaporize naphtha. As used herein, "medium pressure stream" refers to <NUM> psig to <NUM> psig (<NUM> kPa to <NUM> MPa) steam, "low pressure steam" refers to <NUM> psig to <NUM> psig (<NUM> kPa to <NUM> kPa) steam, "hot quench water" refers to water having a temperature of from <NUM> to <NUM>, and "medium quench water" refers to water having a temperature of from <NUM> to <NUM>.

According to additional embodiments, the quench tower <NUM> may be operable with water or oil as a quenching media. In one embodiment, the quench tower is a stripper like apparatus where the product stream is a vapor and the quenching media is the liquid. The quench tower <NUM> may serve to cool the product stream as well as strip it of contaminants. In some embodiments, such as when the product stream is relatively heavy like naphtha, an oil quench may be utilized to strip heavy hydrocarbons from the product stream. If such process were performed with a water quench, some water may condense and undesirably form two liquid phases of oil and water. For example, the quench tower may be designed to operate as a water quench for the ethane and/or propane dehydrogenation reactions, but may operate as an oil quench tower in the case of naphtha cracking, which may require some design modifications relative to a water quench tower. When the tower is operated as an oil quench tower, the booster compressor may need to be bypassed. The bottoms may be a heavy crude oil and could be sent to the combustor for supplemental fuel.

Claim 1:
A method for processing chemical streams, the method comprising:
operating a first chemical process comprising contacting a first feed stream with a first catalyst in a reactor, wherein the reactor comprises an upstream reactor section operating as a fast fluidized, turbulent, or bubbling bed reactor and a downstream reactor section operating as a dilute phase riser reactor, the upstream reactor section having an average cross-sectional area that is at least <NUM>% of the average cross-sectional area of the downstream reactor section, and wherein the contacting of the first feed stream with the first catalyst causes a first reaction which forms a first product stream;
stopping the first chemical process and removing the first catalyst from the reactor; and
operating a second chemical process comprising contacting a second feed stream with a second catalyst in the reactor, wherein the contacting of the second feed stream with the second catalyst causes a second reaction which forms a second product stream; wherein:
the first reaction is a dehydrogenation reaction, a cracking reaction, a dehydration reaction, or a methanol-to-olefin reaction;
the second reaction is a dehydrogenation reaction, a cracking reaction, a dehydration reaction, or a methanol-to-olefin reaction; and
the first reaction and the second reaction are different types of reactions.