Delivery Nozzle Assembly

Abstract

A feed nozzle assembly for cocurrently introducing vapor and liquid into a reactor vessel, the feed nozzle assembly comprising: (a) an annular enclosure surrounding an annular feed conduit; and (b) an atomized vapor conduit surrounded by the annular feed conduit. The annular feed conduit includes a first portion having a first outlet and a second portion having a second outlet opposite the first outlet. The first outlet fluidly connects the first and second portions. The second portion is lined with a non-metallic conduit. The second outlet of the annular feed conduit traverses the annular enclosure. The atomized vapor conduit has an outlet end with one or more openings disposed upstream of the first outlet of the annular feed conduit.

Description

[Technical Field]

[0001] This invention relates to a feed nozzle for the cocurrent introduction of gases and liquids into a reactor vessel, and particularly for introducing atomized steam and pyrolysis oil feed into a catalytic cracking reactor. [Background technology]

[0002]

[0002] Many petroleum refinery and chemical plant units utilize nozzles to distribute liquid and / or gaseous feeds to the unit. In some processes, the ability of the nozzle to distribute the feed to the unit is critical to the productivity of the unit. An example of such a process is fluid catalytic cracking, in which the large chain hydrocarbon molecules found in crude oil are cracked with the aid of a catalyst into smaller, more valuable commercial products, such as gasoline-range hydrocarbons and diesel. Typically, the hydrocarbons are introduced into a reactor through a feed nozzle, where the feed is contacted with a regenerated particulate solids catalyst. The catalyst selectively supports the desired cracking reaction.

[0003]

[0003] Such a supply nozzle may include an inner tube defining a steam conduit and an outer tube disposed around the inner tube, the outer surface of the inner tube and the inner surface of the outer tube defining an annular hydrocarbon conduit, each of the tubes having an inlet end and an opposite outlet end.

[0004]

[0004] Petroleum hydrocarbon streams, such as vacuum gas oil or reduced crude oil, are commonly upgraded through the FCC process, but there is an increasing demand for upgrading heat-sensitive and / or non-petroleum hydrocarbons (i.e., renewable and recycled sources) along with the hydrocarbon stream in the FCC process. By upgrading the heat-sensitive and / or non-petroleum hydrocarbons along with the hydrocarbon stream, the resulting upgraded fuel contains renewable content, allowing the net petroleum hydrocarbon content of the upgraded fuel to be reduced.

[0005] Heat-sensitive feeds include both petroleum and non-petroleum feeds that may be unstable at the operating temperatures of many refinery / chemical processes. This instability can cause the heat-sensitive feed to polymerize or decompose in process equipment. Examples of such feeds may include, but are not limited to, biomass, plastics, waste products, and products produced from the thermal cracking of hydrocarbons that contain low-boiling components that are volatile at near ambient conditions.

[0006] Non-petroleum hydrocarbons include biofuels derived from organic biomass, particularly pyrolysis oil, also commonly referred to as biomass-derived pyrolysis oil. Pyrolysis oil is produced by thermal cracking, including the recently developed fast pyrolysis process. Pyrolysis oil is typically a complex, highly oxygenated organic liquid containing 20-30% water by weight with high acidity (total acid number (TAN) > 10). In other embodiments, pyrolysis oil can be derived from recycled plastics or processed pyrolysis oil, i.e., feeds with low oxygen or water content.

[0007]

[0007] Pyrolysis oil and / or heat-sensitive feeds tend to deteriorate, coke, foul equipment, or vaporize prematurely as the feed temperature increases when injected into an FCC unit. Injection can occur in a riser and / or a fluidized catalyst bed. Previous attempts to co-process pyrolysis oil streams with hydrocarbon streams have involved deoxygenating the pyrolysis oil. Such an approach adds a unit operation to the upgrading process, along with additional capital costs. Feed lines containing a mixture of hydrocarbon and pyrolysis oil streams are generally prone to clogging due to the presence of the pyrolysis oil stream in the feed line.

[0008] Modifications to the feed nozzle have been considered to address the coking / fouling problem by incorporating either a coolant flow and / or a mechanical cleaning device into the feed injector. The coolant flow can be gas or liquid and serves to remove heat from the heat-sensitive feedstock. Possible coking / fouling can be mechanically removed at some frequency using a cleaning device that scrapes or scrapes the internal surface of the feed injector.

[0009] However, both modifications have several drawbacks. The coolant flow can adversely affect the mixing of the injected feedstock with the circulating catalyst flowing in the FCC riser, resulting in a low-yield structure. The gas coolant can add load to the wet gas compressor, which can be a limiting operating parameter for the process. Liquid coolants also require atomization, similar to the feedstock, to achieve good mixing with the catalyst. Both coolant types add complexity to the injector design and the piping network for operating the injector.

[0010]

[0010] Mechanical devices for removing coke / contaminants are operated automatically or manually with the shaft, and any device that separates from the shaft or packing around the shaft can leak process materials into the atmosphere.

[0011]

[0011] WO 2015 / 119598 describes a feed distributor including a pyrolysis oil feed line and a hydrocarbon feed line having respective outlets to a mixing zone for separately supporting the flow of a hydrocarbon stream and a pyrolysis oil stream into the mixing zone. The hydrocarbon stream and the pyrolysis oil stream are mixed in the mixing zone to form a mixture of the pyrolysis oil stream and the hydrocarbon stream. The mixture of the pyrolysis oil stream and the hydrocarbon stream is introduced into a reaction zone, where they are catalytically cracked in the presence of a particulate cracking catalyst. Summary of the Invention

[0012]

[0012] It is therefore desirable to provide a method and apparatus that allows heat-sensitive feeds and / or mixtures, including heat-sensitive feeds such as pyrolysis oils and hydrocarbon streams, to be upgraded through catalytic cracking, such as in a fluidized catalytic cracking unit, while avoiding excessive plugging of the feed lines.

[0013] A feed nozzle assembly for cocurrently introducing vapor and liquid into a reactor vessel, the feed nozzle assembly comprising: (a) an annular enclosure surrounding an annular feed conduit; and (b) an atomized vapor conduit surrounded by the annular feed conduit. The annular feed conduit includes a first portion having a first outlet and a second portion having a second outlet opposite the first outlet. The first outlet fluidly connects the first and second portions. The second portion is lined with a non-metallic conduit. The second outlet of the annular feed conduit traverses the annular enclosure. The atomized vapor conduit has an outlet end with one or more openings disposed upstream of the first outlet of the annular feed conduit. [Brief explanation of the drawings]

[0014] [Figure 1] 1 shows a longitudinal cross-sectional view of a delivery nozzle assembly of the present invention. [Figure 2]

[0015] 2 shows a longitudinal cross-sectional view of the delivery nozzle assembly of FIG. 1 inserted into a container. [Figure 3]

[0016] 1 shows the maximum difference between wall temperature and feed temperature when using a feed nozzle assembly incorporating a non-metallic conduit. DETAILED DESCRIPTION OF THE INVENTION

[0015]

[0017] The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.

[0016]

[0018] Methods and fuel processors for supplying liquid and vapor feeds to a process are provided herein. In one embodiment, a process for upgrading a heat-sensitive stream, such as a pyrolysis oil product stream, is provided herein. As referred to herein, "upgrading" refers to the conversion of relatively high-boiling hydrocarbons to lower-boiling hydrocarbons. These feedstocks may be fossil or non-fossil feedstocks. The upgrading process generally provides a heat-sensitive stream suitable for use as transportation fuels and other valuable products, such as olefins. In the methods and fuel processors described herein, the heat-sensitive stream is catalytically cracked in a reaction zone in the presence of a particulate cracking catalyst. The reaction zone, as referred to herein, is the area or space where the particulate cracking catalyst is mixed with the heat-sensitive stream. Catalytic cracking is carried out at temperatures above 100°C. In some embodiments, the heat-sensitive stream may polymerize at temperatures above 25°C and form deposits within the unit. Deposit formation is a concern in the feed lines leading to the reaction / riser zone.

[0017]

[0019] Deposit formation in the feed lines leading to the reaction zone can result in plugging, which may require shutting down the fuel processor and cleaning the plugged feed lines. To minimize the temperature increase of the pyrolysis oil stream according to the embodiments described herein, the pyrolysis oil stream is insulated within the feed nozzle by a heat shield. In some embodiments, the heat shield surrounds the pyrolysis oil stream and serves to maintain the temperature of the pyrolysis oil stream at a temperature of about 160°C or less substantially until introduction into the reaction zone. While not wishing to be bound by any particular theory, it is believed that a temperature increase of the pyrolysis oil stream above about 160°C may result in deposit formation due to polymerization within the pyrolysis oil stream. By maintaining the temperature of the pyrolysis oil stream at a temperature of about 160°C or less substantially until introduction into the reaction zone, deposit formation prior to introduction of the pyrolysis oil stream into the reaction zone is minimized, at least while the pyrolysis oil stream is in the fuel nozzle outside the reaction zone, where deposit formation may cause plugging.

[0018]

[0020] In some embodiments, the feed nozzle may be used in a variety of reactor vessels and in a variety of operating modes, including, but not limited to, upflow, downflow, riser, or fluidized bed. In some embodiments, the feed nozzle may be used in a number of processes where it is desirable to insulate the feed from external sources.

[0019]

[0021] An exemplary embodiment of a feed nozzle will now be described with reference to FIG. 1 . The feed nozzle assembly 100 includes an annular enclosure 102 surrounding an annular feed conduit 104. The annular feed conduit 104 has a first portion 130 and a second portion 114. In some embodiments, the length of the second portion 114 is less than the length of the first portion 130. In some embodiments, the inner diameter of the second portion 114 can be less than the inner diameter of the first portion 130. In other embodiments, the inner diameter of the second portion 114 can be equal to or greater than the inner diameter of the first portion 130. The first portion 130 has an inlet end 106 and an outlet end 108. The outlet end 108 has an opening 110 that fluidly connects the first portion 130 to the second portion 114. The second portion 114 has an outlet 112 opposite the opening 110. The outlet 112 traverses the annular enclosure 102.

[0020]

[0022] The first portion 130 of the annular feed conduit 104 surrounds the atomized vapor conduit 116. The atomized vapor conduit 116 has an inlet end 118 and an outlet end 120. The outlet end 120 includes one or more openings 122 through which the atomized vapor exits. In some embodiments, the one or more openings 122 are disposed upstream of the openings 110 that create an atomization zone at the outlet end 108 of the annular feed conduit 104, where the atomized vapor atomizes the feed. The length between the one or more openings 122 and the openings 110 can be determined by one skilled in the art.

[0021]

[0023] The inner diameter of the annular enclosure 102 is greater than the outer diameter of the first portion 130 of the annular supply conduit 104. The inner diameter of the annular enclosure 102 is greater than the outer diameter of the second portion 114 of the annular supply conduit 104. The inner diameter of the first portion 130 of the annular supply conduit 104 is greater than the outer diameter of the atomized vapor conduit 116. In some embodiments, the inner diameter of the second portion 114 is equal to or less than the inner diameter of the atomized vapor conduit 116. In some embodiments, the inner diameter of the second portion 114 is greater than the inner diameter of the atomized vapor conduit 116.

[0022]

[0024] The annular enclosure 102 insulates the annular supply conduit 104. The inner diameter of the annular enclosure 102, the outer diameter of the annular enclosure 102, and the pipe wall thickness can be determined by one skilled in the art. The annular enclosure 102 may be made of materials commonly found in the refining / chemical processing field, such as, but not limited to, stainless steel or other types of steel. The annular enclosure 102 may be hollow and filled with one or more insulating materials.

[0023]

[0025] In some embodiments, the insulating material may have a thermal conductivity in the range of 0.0017 to 1.73 Watts / (m-°K), 0.017 to 0.865 Watts / (m-°K), or 0.173 to 0.519 Watts / (m-°K). In some embodiments, the insulating material may be a gas, such as, but not limited to, air or an inert gas. Gaseous insulating materials may have a thermal conductivity in the range of 0.0173 to 0.432 Watts / (m-°K), 0.0865 to 0.259 Watts / (m-°K), or 0.13 to 0.173 Watts / (m-°K). In other embodiments, the air or inert gas within the annular enclosure 102 is removed to create a vacuum, thereby further reducing the thermal conductivity.

[0024]

[0026] In some embodiments, the annular enclosure 102 may be filled with one or more solid insulating materials. The solid insulating materials may have a thermal conductivity in the range of 0.0017 to 1.73 Watts / (m-°K), 0.017 to 1.3 Watts / (m-°K), or 0.173 to 0.865 Watts / (m-°K). In some embodiments, the insulating materials may be selected from, but are not limited to, granular materials, heater / boiler insulation, household insulation, etc.

[0025]

[0027] In some embodiments, after the annular enclosure 102 is filled with the insulating material, a vacuum may be pulled to evacuate any remaining gas within the annular conduit, thereby further reducing thermal conductivity. These thermally conductive materials may provide thermal insulation at least equivalent to that of air while maintaining smaller scale equipment designs. Additionally, these thermally conductive materials may come in a variety of forms (e.g., blankets, ropes, granules) to accommodate a wide range of annular conduits 102. Placing such materials within air-containing cavities, gaps, or annular spaces displaces the volume occupied by the air, thereby limiting pressure buildup within the equipment as temperatures increase during operation.

[0026]

[0028] The annular supply conduit 104 may be made of a material commonly found in the refining / chemical processing field that is resistant to acidic liquids, such as, but not limited to, stainless steel or other types of steel. The inner diameter of the first and second portions 130 and 132 of the annular supply conduit 104, the outer diameter of the first and second portions 130 and 132 of the annular supply conduit 104, and the pipe wall thickness can be determined by one skilled in the art.

[0027]

[0029] In another embodiment, second portion 114 surrounds non-metallic conduit 150. Non-metallic conduit 150 may be cylindrical. In some embodiments, the inner diameter of non-metallic conduit 150 may be equal to or less than the inner diameter of atomized vapor conduit 116. In other embodiments, the inner diameter of non-metallic conduit 150 may be greater than the inner diameter of atomized vapor conduit 116. The inner diameter of non-metallic conduit 150, the outer diameter of non-metallic conduit 150, and the thickness of the conduit can be determined by one of ordinary skill in the art.

[0028]

[0030] The non-metallic conduit 150 may have a thermal conductivity less than the material of the second portion 114. In some embodiments, the non-metallic conduit 150 may be an insulating material or a composite of insulating materials. The insulating material may have a thermal conductivity in the range of 0.0432 to about 3.46 Watts / (m-°K), 0.0865 to 1.73 Watts / (m-°K), or 0.173 to 0.865 Watts / (m-°K). In some embodiments, the non-metallic material may be selected from low thermal conductivity materials, such as ceramics, including, but not limited to, examples such as high alumina ceramics and fused silica ceramics. The thermal conductivities of some example non-metallic materials are presented in Table 1.

[0029] [Table 1]

[0030]

[0031] The atomized vapor conduit 116 may be made of a material commonly found in the refining / chemical processing field that is resistant to acidic liquids, such as, but not limited to, stainless steel or other types of steel. The inner diameter of the atomized vapor conduit 116, the outer diameter of the atomized vapor conduit 116, and the pipe wall thickness can be determined by one skilled in the art. The number and spacing of the openings 122 can be determined by one skilled in the art.

[0031]

[0032] Referring to FIG. 2 , in some embodiments, the feed nozzle assembly 100 can be inserted into a vessel 300 having a sidewall 301. The vessel 300 can be a reactor or a riser. The thickness of the sidewall 301 can be determined by one of ordinary skill in the art. For clarity, the same reference numbers are used throughout the drawings to indicate the same terms. In some embodiments, the feed nozzle assembly 100 can be inserted into any surface of the vessel 300, i.e., the top, bottom, or side.

[0032]

[0033] In some embodiments, feed nozzle assembly 100 is inserted into nozzle sleeve 202 having refractory shroud 204 therearound. Refractory shroud 204 is typically recessed within vessel 300 and may or may not extend beyond sidewall 301. In some embodiments, feed nozzle assembly 100 may be inserted into vessel 300 without nozzle sleeve 202. In other embodiments, feed nozzle assembly 100 may be inserted into any suitable nozzle or suitable opening in vessel 300. Nozzle sleeve 202 penetrates sidewall 301 into reaction zone 302. Feed nozzle assembly 100 and nozzle sleeve 202 are typically oriented at an angle ranging from 0 to 90 degrees from horizontal, typically 45 degrees from horizontal into reaction zone 302 as shown in FIG. 2 .

[0033]

[0034] The feed nozzle assembly 100 may experience the most severe reactor process conditions if inserted near the main reaction flow path within the reaction zone 302. If the feed nozzle assembly 100 is inserted near or adjacent to the main reaction flow path, the feed nozzle assembly 100 will be subjected to less severe, but nevertheless highly thermal, process conditions. In some embodiments, assuming the process flow path within the reaction zone 302 is vertically upward, the underside of the feed nozzle assembly 100 is exposed to the heat of the reactor zone 302 to a greater extent than the upper side of the feed nozzle. Although the nozzle sleeve 202 and refractory shroud 204 provide some thermal shielding for the feed nozzle assembly 100, the heat exposure of the feed nozzle assembly 100 remains severe.

[0034]

[0035] One skilled in the art would be able to design and construct nozzle sleeve 202 to reside within sidewall 301 of vessel 300. Channel 214 traverses nozzle sleeve 202 and shroud refractory 204. Channel 214 provides a fluid conduit from outlet 112 of second portion 114 through inlet 216 to outlet 218. Outlet 218 is opposite inlet 216. Outlet 218 of channel 214 is located within reactor zone 302. In some embodiments, nozzle sleeve 202 is constructed from a metal, which may be stainless steel, and shroud refractory 204 may be constructed from a refractory. The composition and size of nozzle sleeve 202 and refractory shroud 204 can be determined by one skilled in the art.

[0035]

[0036] During normal operation of the feed nozzle assembly 100 according to an embodiment of the present invention, atomized steam passes from the inlet end 118 along the atomized steam conduit 116 and exits the atomized steam conduit 116 through the opening 122. Pyrolysis oil is fed into the inlet end 106 of the annular feed conduit 104 and passes along the annular feed conduit 104.

[0036]

[0037] The atomizing vapor exits the one or more openings 122 and mixes with the pyrolysis oil in the annular feed conduit 104, resulting in fine jets that disperse the pyrolysis oil. The mixture of atomizing vapor and pyrolysis oil passes along the non-metallic conduit 150 through the openings 110 and exits through the openings 112 in the annular enclosure 102. The one or more openings 122 are adapted to substantially uniformly atomize the mixture of atomizing vapor and pyrolysis oil before entering the openings 110. In some embodiments, the openings 112 are aligned with the channel 214 to exit into the vessel 300 via the outlet 218. The vessel can be, but is not limited to, a fluidized catalytic cracking reactor.

[0037]

[0038] The pyrolysis oil in the second portion 114 is shielded from the heat of the vessel 300 by the non-metallic conduit 150. The heat shielding ability of the non-metallic conduit 150 for non-metallic insulating materials was evaluated in the following examples.

[0038]

[0039] For the analysis, the annular enclosure 102 was filled with a granular material having thermal conductivities as shown in Table 2.

[0039] [Table 2]

[0040] In Example 1, finite element analysis was performed to predict thermal gradients on certain internal surfaces of a particular feed nozzle under various process operating conditions. Of primary interest was the temperature of the internal surface of the non-metallic conduit 150, which contacts the heat-sensitive feedstock. Shielding the internal surface of the non-metallic conduit 150 from reaching excessive temperatures can mitigate potential coking and contamination of the heat-sensitive feedstock within the feed nozzle assembly 100. In other words, the thermal shielding provided by the non-metallic conduit 150 minimizes the difference between the heat-sensitive feedstock inlet temperature at the inlet end 106 and the surface temperatures of the internal contacting surfaces, such as the annular feed conduit 104, the outlet end 108, the opening 110, the non-metallic conduit 150, and the outlet 112.

[0041] Referring to FIG. 1 , the feed nozzle assembly 100 was modeled so that the temperature of the heat-sensitive feedstock entering the opening 110 could be compared to the predicted wall temperature distributed along the non-metallic conduit 150 to the outlet 112. The annular enclosure 102 was modeled as being filled with a granular material having the properties shown in Table 2. In one example, the annular enclosure 102 is exposed to a process steam having a temperature of approximately 345° C. In a typical feed nozzle assembly 100 operating range, the maximum temperature difference between any predicted wall temperature of the non-metallic conduit 150 along its length and the heat-sensitive feedstock temperature entering the opening 110 was approximately 8° C. (See FIG. 3 ). This low temperature increase allows the heat-sensitive feedstock to be maintained at a temperature of approximately 160° C. or less until introduction into the reaction zone 302.

[0042]

[0042] Although several embodiments of the present disclosure have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible without substantially departing from the teachings of the present disclosure. Accordingly, such modifications are intended to be included within the scope of the present disclosure as defined in the claims.

Claims

1. 1. A feed nozzle assembly for cocurrently introducing vapor and liquid into a reactor vessel, comprising: (a) an annular enclosure surrounding an annular supply conduit; (b) an atomizing vapor conduit surrounded by the annular supply conduit; the annular supply conduit comprises a first portion having a first outlet and a second portion having a second outlet opposite the first outlet, the first outlet fluidly connecting the first portion and the second portion; the second portion is lined with a non-metallic conduit; the second outlet of the annular supply conduit traverses the annular enclosure; a delivery nozzle assembly, the atomized vapor conduit having an outlet end with one or more openings disposed upstream of the first outlet of the annular delivery conduit;

2. 2. The delivery nozzle assembly of claim 1, wherein the inner diameter of the second portion of the annular delivery conduit is equal to or less than the inner diameter of the first portion of the annular delivery conduit.

3. The delivery nozzle assembly of claim 1 , wherein the inner diameter of the second portion of the annular delivery conduit is equal to or greater than the inner diameter of the first portion of the annular delivery conduit.

4. 2. The delivery nozzle assembly of claim 1, wherein the length of the second portion of the annular delivery conduit is less than or equal to the length of the first portion of the annular delivery conduit.

5. The delivery nozzle assembly of claim 1 , wherein an inner diameter of the annular enclosure exceeds an outer diameter of the annular delivery conduit.

6. The delivery nozzle assembly of claim 1 , wherein an inner diameter of the first portion of the annular delivery conduit exceeds an outer diameter of the atomized vapor conduit.

7. 2. The delivery nozzle assembly of claim 1, wherein the inner diameter of the second portion of the annular delivery conduit is equal to or less than the inner diameter of the atomized vapor conduit.

8. The delivery nozzle assembly of claim 1, wherein the non-metallic conduit has a thermal conductivity in the range of about 0.173 to about 3.46 Watts / (m-°K).

9. The delivery nozzle of claim 8 wherein the non-metallic conduit is a high alumina ceramic.

10. The delivery nozzle of claim 8 , wherein the non-metallic conduit is a fused silica ceramic.

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