Patent Application
20130251597
A nozzle reactor is a pipe or tube of varying cross sectional area in which two or more materials interact to alter the properties and/or chemical composition of the materials. The geometry of the nozzle reactor enhances the desired interaction between the two materials to produce the desired output.
In one type of nozzle reactor, the desired interaction is achieved by accelerating one or more of the materials to a high velocity and combining it with another material. The additional kinetic energy imparted to the accelerated material helps facilitate the desired interaction. However, the high velocity and demanding conditions in the reactor make it difficult to combine the materials in a uniform, even manner.
The high velocities and demanding conditions also tend to produce a high friction inside the reactor. The friction wears away certain areas in the reactor thereby increasing maintenance and repair costs. In some instances, it the amount of wear is high enough to force the user to regularly replace large portions of the reactor.
Another issue that can arise with the use of nozzle reactors relates to how efficiently the nozzle reactors can operate when scaled up to handle larger amounts of material. Typically, the injection holes through which material is injected into the mixing chamber of the nozzle reactor have a circular cross-section. As the nozzle reactors are scaled up, the dimensions of the circular injection holes increase. When the circular injection holes become too large, insufficient inertial or shear forces are exerted on the circular holes by the material traveling through the injection holes. As a result, the material traveling through the holes does not break up into the smaller droplets necessary for efficient mixing or shearing with the other material injected into the nozzle reactor. When efficient mixing or shearing does not occur, the overall conversion efficiency of the nozzle reactor is reduced.
A nozzle reactor and a method for using it are disclosed herein. Embodiments disclosed below are not intended to be limiting in any way. Instead, the present disclosure is directed toward novel and nonobvious features, aspects, and equivalents of the embodiments and methods described below. The disclosed features and aspects of the embodiments can be used alone or in various novel and nonobvious combinations and sub-combinations of aspects of one another.
In one embodiment, the nozzle reactor includes a passage having a converging-diverging shape that accelerates a reacting fluid. The reacting fluid is combined and reacted with a feed material to produce a variety of desirable products. The kinetic energy along with any thermal energy present in the materials can produce desirable reactions.
In some embodiments, the nozzle reactor includes a main passage through which the reacting fluid passes. The main passage includes a region having a converging-diverging shape that accelerates the reacting fluid to at least Mach 1. The nozzle reactor also includes a feed passage that intersects the main passage after the reacting fluid has passed through the converging-diverging region of the main passage. Feed material travels through the feed passage to the main passage where it contacts and reacts with the reacting fluid.
The nozzle reactor can include a distributor, and in some embodiments the distributor uniformly distributes the feed material through an annular cavity and into contact with the reacting fluid. The distributor can include a plurality of injection holes spaced evenly around the annular cavity for passing feed material from the annular cavity into the main passage. In some embodiments, these injection holes have a non-circular cross-sectional shape, such as a cross shape. In some embodiments, the distributor can prevent the feed material from flowing toward the reacting fluid in an uneven manner—e.g., more of the feed material reaches the reacting fluid on the side closest to the incoming feed passage then on the other side. In some embodiments, the distributor can be a physically separate component that is removable and replaceable.
In some embodiments, the flow of feed material toward the main passage and the reacting fluid is uniform and even. In certain embodiments, the flow may form an annulus as it flows from the distributor toward the main passage. In some embodiments, the flow rate and/or velocity of the feed material can vary less than 10% along a given circumference of the annulus thereby preventing uneven injection of the feed material into the main passage.
In some embodiments, the distributor includes a wear ring that is removable and replaceable. The main passage can pass through the wear ring and the feed passage can meet the main passage immediately upstream of the wear ring. In certain embodiments, the wear ring is the first structure the reacting fluid and the feed material encounter after mixing. This is a location in the nozzle reactor that can be subject to substantial wear and erosion due to the shear forces and the collision of the reacting fluid and the feed material in this area.
In some embodiments, the nozzle reactor can include a head portion and a body portion coupled together. The head portion and the body portion can be separated to provide access to the distributor and the wear ring. This allows the operator to remove the head portion and replace the distributor and/or wear ring when they wear out. Although the wear ring may be securely coupled to the distributor, it can still be a physically separate component having readily defined boundaries that allow it to be identified, removed, and replaced.
In some embodiments, the nozzle reactor includes two or more regions having a converging-diverging shape positioned in series. The first region accelerates the reacting fluid before it impacts the feed material. The feed material can then be mixed with the reacting fluid. The resulting mixture passes through the second converging-diverging region. The second region is larger than the first region to provide adequate mixing and residence time to drive the reaction forward. The second region allows a portion of the mixture near the outside edge to flow backward thereby creating an eddy of sorts inside the second region.
In some embodiments, the nozzle reactor may be used to crack heavy hydrocarbon material into distillates. The reacting fluid or cracking fluid can be steam, natural gas, or other suitable fluid. In certain embodiments, the reacting fluid is accelerated to at least Mach 1 and mixed with the heavy hydrocarbon material to initiate cracking. The temperature and/or kinetic energy of the reacting fluid and the heavy hydrocarbon material are sufficient to convert a substantial amount of it to distillates. The reacting fluid functions as a hydrogen source thereby minimizing coke formation due to excessive hydrogen loss from the heavy hydrocarbon material.
In some embodiments, the nozzle reactor can be used as part of a method for cracking heavy hydrocarbon material and forming distillates. The method may include reacting the heavy hydrocarbon material with a reacting fluid such as steam or natural gas in the nozzle reactor to produce distillates. In certain embodiments, the effluent from the nozzle reactor may be separated to isolate any remaining heavy hydrocarbon material and recycled back through the nozzle reactor until it is mostly or completely eliminated. The recycled heavy hydrocarbon material does not produce significant amounts of coke due to the hydrogen rich environment supplied by the reacting fluid. The entire process may be operated without the use of a catalyst or added hydrogen.
The term “heavy hydrocarbon material” is used to refer to the hydrocarbon fraction that has a boiling point at or above 525° C. This material may be obtained from a number of sources such as the residue from distillation operations such as atmospheric or vacuum distillation, cyclonic separation, the residue from hydroskimming operations, natural sources such as tar sands (including oil sands and oil shale), and even certain high viscosity crude oils. The term “distillates” is used to refer to the hydrocarbon fraction that has a boiling point below 525° C.
The foregoing and other features, utilities, and advantages of the subject matter described herein will be apparent from the following more particular description of certain embodiments as illustrated in the accompanying drawings. In this regard, it is be understood that the scope of the invention is to be determined by the claims as issued and not by whether any given subject matter includes any or all features or aspects noted in this Summary or addresses any issues noted in the Background.
The preferred and other embodiments are disclosed in association with the accompanying drawings in which:
An improved nozzle reactor is described herein. Although the nozzle reactor is described primarily in the context of upgrading heavy hydrocarbon materials, it should be appreciated that the referenced structure, concepts, and features may be used in a variety of other settings that would be recognized by those of ordinary skill in the art. Also, it should be understood, that the features, advantages, characteristics, etc. of one embodiment may be applied to any other embodiment to form an additional embodiment unless noted otherwise.
A nozzle reactor can be any type of apparatus or device having a convergent and/or divergent internal shape in which one or more materials are injected for the purpose of chemically and/or mechanically interacting with each other. The internal shape increases the kinetic energy of the one or more materials to facilitate the desired interaction.
It should be noted that for purposes of this disclosure, the term “coupled” means the joining of two members directly or indirectly to one another. Such joining may be stationary in nature or movable in nature. Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate member being attached to one another. Such joining may be permanent in nature or alternatively may be removable or releasable in nature.
The nozzle reactor 100 includes a feed passage 108 that is in fluid communication with the main passage 106. The feed passage 108 intersects the main passage 106 at a location between the portions 102, 104. The main passage 106 includes an entry opening 110 at the top of the head portion 102 and an exit opening 112 at the bottom of the body portion 104. The feed passage 108 also includes an entry opening 114 on the side of the body portion 104 and an exit opening 116 that is located where the feed passage 108 meets the main passage 106.
During operation, the nozzle reactor 100 includes a reacting fluid that flows through the main passage 106. The reacting fluid enters through the entry opening 110, travels the length of the main passage 106, and exits the nozzle reactor 100 out of the exit opening 112. A feed material flows through the feed passage 108. The feed material enters through the entry opening 114, travels through the feed passage 106, and exits into the main passage 108 at exit opening 116.
The main passage 106 is shaped to accelerate the reacting fluid. The main passage 106 may have any suitable geometry that is capable of doing this. As shown in
The convergent section 120 is where the main passage 106 narrows from a wide diameter to a smaller diameter, and the divergent section 124 is where the main passage 106 expands from a smaller diameter to a larger diameter. The throat 122 is the narrowest point of the main passage 106 between the convergent section 120 and the divergent section 124. When viewed from the side, the main passage 106 appears to be pinched in the middle, making a carefully balanced, asymmetric hourglass-like shape. This configuration is commonly referred to as a convergent-divergent nozzle or “con-di nozzle”.
The convergent section of the main passage 106 accelerates subsonic fluids since the mass flow rate is constant and the material must accelerate to pass through the smaller opening. The flow will reach sonic velocity or Mach 1 at the throat 122 provided that the pressure ratio is high enough. In this situation, the main passage 106 is said to be in a choked flow condition.
Increasing the pressure ratio further does not increase the Mach number at the throat 122 beyond unity. However, the flow downstream from the throat 122 is free to expand and can reach supersonic velocities. It should be noted that Mach 1 can be a very high speed for a hot fluid since the speed of sound varies as the square root of absolute temperature. Thus the speed reached at the throat 122 can be far higher than the speed of sound at sea level.
The divergent section 124 of the main passage 106 slows subsonic fluids, but accelerates sonic or supersonic fluids. A convergent-divergent geometry can therefore accelerate fluids in a choked flow condition to supersonic speeds. The convergent-divergent geometry can be used to accelerate the hot, pressurized reacting fluid to supersonic speeds, and upon expansion, to shape the exhaust flow so that the heat energy propelling the flow is maximally converted into kinetic energy.
The flow rate of the reacting fluid through the convergent-divergent nozzle is isentropic (fluid entropy is nearly constant). At subsonic flow the fluid is compressible so that sound, a small pressure wave, can propagate through it. At the throat 122, where the cross sectional area is a minimum, the fluid velocity locally becomes sonic (Mach number=1.0). As the cross sectional area increases the gas begins to expand and the gas flow increases to supersonic velocities where a sound wave cannot propagate backwards through the fluid as viewed in the frame of reference of the nozzle (Mach number>1.0).
The main passage 106 only reaches a choked flow condition at the throat 122 if the pressure and mass flow rate is sufficient to reach sonic speeds, otherwise supersonic flow is not achieved and the main passage will act as a venturi tube. In order to achieve supersonic flow, the entry pressure to the nozzle reactor 100 should be significantly above ambient pressure.
The pressure of the fluid at the exit of the divergent section 124 of the main passage 106 can be low, but should not be too low. The exit pressure can be significantly below ambient pressure since pressure cannot travel upstream through the supersonic flow. However, if the pressure is too far below ambient, then the flow will cease to be supersonic or the flow will separate within the divergent section 124 of the main passage 106 forming an unstable jet that “flops” around and damages the main passage 106. In one embodiment, the ambient pressure is no higher than approximately 2-3 times the absolute pressure in the supersonic gas at the exit.
The supersonic reacting fluid collides and mixes with the feed material in the nozzle reactor 100 to produce the desired reaction. The high speeds involved and the resulting collision produces a significant amount of kinetic energy that helps facilitate the desired reaction. The reacting fluid and/or the feed material may also be pre-heated to provide additional thermal energy to react the materials.
The nozzle reactor 100 may be configured to accelerate the reacting fluid to at least approximately Mach 1, at least approximately Mach 1.5, or, desirably, at least approximately Mach 2. The nozzle reactor may also be configured to accelerate the reacting fluid to approximately Mach 1 to approximately Mach 7, approximately Mach 1.5 to approximately Mach 6, or, desirably, approximately Mach 2 to approximately Mach 5.
As shown in
The main passage 106 also includes opposing diverging side walls 130, 132. The side walls 130, 132 curve outwardly (when viewed in the direction of flow) away from the central axis of the main passage 106. The side walls 130, 132 form the divergent section 124 of the main passage 106 that allows the sonic fluid to expand and reach supersonic velocities.
The side walls 126, 128, 130, 132 of the main passage 106 provide uniform axial acceleration of the reacting fluid with minimal radial acceleration. The side walls 126, 128, 130, 132 may also have a smooth surface or finish with an absence of sharp edges that may disrupt the flow. The configuration of the side walls 126, 128, 130, 132 renders the main passage 106 substantially isentropic.
The feed passage 108 extends from the exterior of the body portion 104 to an annular chamber 134 formed by head and body portions 102, 104. The portions 102, 104 each have an opposing cavity so that when they are coupled together the cavities combine to form the annular chamber 134. A seal 136 is positioned along the outer circumference of the annular chamber 134 to prevent the feed material from leaking through the space between the head and body portions 102, 104.
It should be appreciated that the head and body portions 102, 104 may be coupled together in any suitable manner. Regardless of the method or devices used, the head and body portions 102, 104 should be coupled together in a way that prevents the feed material from leaking and withstands the forces generated in the interior. In one embodiment, the portions 102, 104 are coupled together using bolts that extend through holes in the outer flanges of the portions 102, 104.
The nozzle reactor 100 includes a distributor 140 positioned between the head and body portions 102, 104. The distributor 140 prevents the feed material from flowing directly from the opening 141 of the feed passage 108 to the main passage 106. Instead, the distributor 140 annularly and uniformly distributes the feed material into contact with the reacting fluid flowing in the main passage 106.
As shown in
The distributor 140 includes a plurality of holes 144 that extend through the outer wall 148 and into an interior chamber 146. The holes 144 are evenly spaced around the outside of the distributor 140 to provide even flow into the interior chamber 146. The interior chamber 146 is where the main passage 106 and the feed passage 108 meet and the feed material comes into contact with the supersonic reacting fluid.
The distributor 140 is thus configured to inject the feed material at about a 90° angle to the axis of travel of the reacting fluid in the main passage 106 around the entire circumference of the reacting fluid. The feed material thus forms an annulus of flow that extends toward the main passage 106. The number and size of the holes 144 are selected to provide a pressure drop across the distributor 140 that ensures that the flow through each hole 144 is approximately the same. In one embodiment, the pressure drop across the distributor is at least approximately 2000 Pascals (Pa), at least approximately 3000 Pa, or at least approximately 5000 Pa.
Turning to
Referring back to
As the size and production capacity of the nozzle reactor is increased, the diameter of the circular holes 144 also increases. As the diameter of the circular holes 144 increases with scale up of the nozzle reactor, the circular holes 144 eventually become too large for feed material traveling therethrough to exert sufficient inertial or shear forces on the circular holes 144. As a result, the feed material traveling through the holes 144 does not break up into the smaller droplets necessary for efficient mixing or shearing with the reacting fluid, and uniform distribution of the feed material is not achieved. Instead, the feed material passing through the circular holes 144 maintains a cone-like structure for a longer radial travel distance and impacts the reactive fluid in large droplets not conducive for intimate mixing with the reacting fluid. Non-uniform kinetic energy transfer from the reacting fluid to the large droplets of feed material results and the overall conversion efficiency of the reactor nozzle is reduced.
Accordingly, in some embodiments where larger nozzle reactors are used to handle higher production capacities (e.g., greater than 1,000 bbl/day), the injection holes 144 can have a non-circular cross-sectional shape.
In some embodiments, the cross-shaped injection hole is a preferred cross-sectional shape. The cross-shaped injection holes can extend the maximum oil flow capacity at a given conversion rate by at least 20 to 30% over circular injection holes having similar cross-sectional areas. With reference to
Changing the aspect ratio of the non-circular injection holes along the major and/or minor axis can varying the level of shear or turbulence generated by the reacting fluid. Generally, elongated thin slots, or shapes having thinner cross sections and at the same time changing orientation of slots along the circumferential direction (such as cross or lobe shape) offer the highest level of shear along the axial and circumferential jet directions. This is generally due to generation of Helmholtz vortices along various axes. The individual vortices develop in pairs with counter rotating directions. The counter rotating vorticies contribute to increased shearing of jet and entrainment of surrounding fluids.
The cross-sectional area of the non-circular injection holes is generally not limited. In some embodiments, the cross-sectional area of the non-circular injection holes is designed for required oil flow capacity for optimum conversion at a given oil supply pressure (e.g., 100 to 150 psig)
Any suitable manner for manufacturing the non-circular injection holes can be used. In some embodiments, the non-circular injection holes are cut using a water jet cutting process or Electro Discharge Machining (EDM). In some embodiments, the internal surfaces of the non-circular injection holes are smooth. The internal surfaces can be made smooth using any suitable techniques, including grinding, polishing, and lapping. Smooth internal surfaces can be preferred because they produce smaller droplets of feed material than when the internal surface of the injection hole is rough.
Other parameters that have been found to impact the size of the feed material droplets include the feed material pressure on the injection hole (increased pressure result in smaller droplet size), the viscosity of the feed material (lower viscosity feed material has smaller droplets), and the spray angle (smaller spray angles provide smaller droplets). Accordingly, one or more of these parameters can be adjusted in the nozzle reactor in order to produce the smaller feed material droplets that lead to better mixing with the reacting material.
One benefit of using non-circular injection holes 144 in larger nozzle reactors handling larger production capacities is that the non-circular injection holes can help to ensure that the core of the feed material jet breaks up into smaller particles over a relatively short radial travel distance.
The non-circular injection holes also help to generate streamwise and spanwise vortices. The interaction of the spanwise (Kelvin-Helmholtz) vortices with the streamwise vortices produce the high levels of mixing. These vortices form, intensify, and then break down, and the high turbulence resulting from the vortex breakdown improves the overall mixing process. Large-scale turbulence is generated along the sides of the injection holes, while small-scale turbulence is generated at the vertices.
Another benefit of using non-circular injection holes 144 is the improvement in entrainment efficiency. The entrainment of feed material in the reacting material at the area near the non-circular injection hole 144 can be four times higher than in a circular injection hole. Higher entrainment efficiency would allow more uniform and earlier mixing of feed material droplets with the reacting material. This would enable thermal and kinetic interaction between streams and result in breakup of larger molecules into smaller molecules.
Still another benefit of using the non-circular injection holes described above is the incremental increase in conversion of heavy residue hydrocarbons, such as 1050° F.+hydrocarbon fractions. Other benefits include increasing the production capacity of a given nozzle reactor, providing a smaller foot print for installation, and reducing recycle volumes of unconverted residue.
Adjusting the cross-section shape of holes 144 in order to allow for scale up of the nozzle reactor without negatively impacting the performance of the nozzle reactor can be preferable to using multiple smaller nozzle reactors arranged in parallel. In the parallel nozzle reactors configuration, each nozzle reactor handles a small portion of overall production capacity and allows for the continued use of circular holes 144. However, while this method will maintain adequate mixing and conversion per nozzle reactor, it will also result in higher capital costs associated with nozzle reactors and the piping needed for feed distribution and collecting converted products.
In some embodiments, throat 122 and divergent section 124 of main passage 106 can also have a non-circular cross section, such as the cross shape, lobe shape, or slotted shape described in greater detail above with respect to injection holes 144. Cracking material is typically injected into the nozzle reactor through this portion of the main passage 106, and by providing a non-circular cross-sectional shape, similar benefits to those described above with respect to the non-circular injection holes 144 can be achieved for the cracking material. For example, increased turbulence of the cracking material and entrainment efficiency between the cracking material and the feed material can be achieved when throat 122 and divergent section 124 have a non-circular shape. As discussed in greater detail previous, increases in turbulence and entrainment efficiency can increase the conversion of large hydrocarbon molecules into smaller hydrocarbon molecules.
In some embodiments, the non-circular shape begins at the narrowest portion of the throat 122 and the non-circular shape continues the length of the divergent section 124 such that the ejection end of the divergent section 124 has the non-circular cross-section shape. The cross-sectional area in the divergent section become larger as the ejection end is approached, but the same cross-sectional shape can be maintained throughout the length of the divergent section 124. As with the injection holes 144, the interior surfaces of the throat 122 and divergent section 124 can have a smooth surface.
In some embodiments, a combination of circular and non-circular injection holes can be used within the same nozzle reactor. Any combination of circular and non-circular injection holes can be used. In some embodiments, the plurality of injection holes provided for the reacting fluid can include both circular and non-circular injection holes. In some embodiments, non-circular injection holes can be used for the reacting material while circular injection holes are used for the cracking fluid. In some embodiments, circular injection holes can be used for the reacting material while non-circular injection holes can be used for the cracking fluid.
The distributor 140 includes a wear ring 150 positioned immediately adjacent to and downstream of the location where the feed passage 108 meets the main passage 106. The collision of the reacting fluid and the feed material causes a lot of wear in this area. The wear ring is a physically separate component that is capable of being periodically removed and replaced.
As shown in
The wear ring 150 can be removed by separating the head portion 102 from the body portion 104. With the head portion 102 removed, the distributor 140 and/or the wear ring 150 are readily accessible. The user can remove and/or replace the wear ring 150 or the entire distributor 140, if necessary.
As shown in
Following the expansion area 160, the main passage 106 includes a second region having a converging-diverging shape. The second region is in the body portion 104 of the nozzle reactor 100. In this region, the main passage includes a convergent section 170 (also referred to herein as a contraction section), a throat 172, and a divergent section 174 (also referred to herein as an expansion section). The converging-diverging shape of the second region differs from that of the first region in that it is much larger. In one embodiment, the throat 172 is at least 2-5 times as large as the throat 122.
The second region provides additional mixing and residence time to react the reacting fluid and the feed material. The main passage 106 is configured to allow a portion of the reaction mixture to flow backward from the exit opening 112 along the outer wall 176 to the expansion area 160. The backflow then mixes with the stream of material exiting the distributor 140. This mixing action also helps drive the reaction to completion.
The dimensions of the nozzle reactor 100 can vary based on the amount of material that is fed through it. For example, at a flow rate of approximately 590 kg/hr, the distributor 140 can include sixteen holes 144 that are 3 mm in diameter. The dimensions of the various components of the nozzle reactor shown in
It should be appreciated that the nozzle reactor 100 can be configured in a variety of ways that are different than the specific design shown in the Figures. For example, the location of the openings 110, 112, 114, 116 may be placed in any of a number of different locations. Also, the nozzle reactor 100 may be made as an integral unit instead of comprising two or more portions 102, 104. Numerous other changes may be made to the nozzle reactor 100.
Turning to
The nozzle reactor 200 differs a few ways from the nozzle reactor 100. The nozzle reactor 200 includes a distributor 240 that is formed as an integral part of the body portion 204. However, the wear ring 150 is still a physically separate component that can be removed and replaced. Also, the wear ring 150 depicted in
In
The clamp 280 fits over outer flanges 286 of the head and body portions 102, 104. As the portions 102, 104 are drawn together by the clamp, the seal lips deflect against the inner surfaces 276 of the portions 102, 104. This deflection elastically loads the lips 284 against the inner surfaces 276 forming a self-energized seal. In one embodiment, the clamp is made by Grayloc Products, located in Houston, Tex.
The nozzle reactor 100, 200 can be used to crack heavy hydrocarbon material into distillates. The heavy hydrocarbon material enters the nozzle reactor 100, 200 through the feed passage 108 and a cracking fluid enters through the main passage 106. The heavy hydrocarbon feed material can be fed “raw” into the reactor or can be separated to eliminate or reduce the amount of distillates present in the feed material.
The heavy hydrocarbon material in the feed material can come from a variety of sources. Examples of suitable sources include the residual fraction of distillation operations such as atmospheric or vacuum distillation, cyclonic separation, or from the residual fraction of hydroskimming operations. Other sources include natural sources such as oil sands (which includes tar sands, oil shale, etc.) or even certain high viscosity crude oils. The concentration of heavy hydrocarbon material in the feed material varies depending on its source and whether it was processed previously.
The composition of the heavy hydrocarbon material can vary widely, but often includes asphaltenes, resins, aromatic hydrocarbons, and saturates in varying amounts. Asphaltenes are large polycyclic molecules that are commonly defined as those molecules that are insoluble in n-heptane and soluble in toluene. Resins are also polycyclic but have a lower molecular weight than asphaltenes. Aromatic hydrocarbons are derivatives of benzene, toluene and xylene. The feed material can also include 12 to 25 wt % micro carbon as determined using ASTM D4530-07.
The feed material can include the heavy hydrocarbon material and other lower boiling fractions. In most situations, it is advantageous to separate distillates from the heavy hydrocarbon material so that it is composed entirely or almost entirely of heavy hydrocarbon material when it enters the nozzle reactor 100, 200. Any suitable separation process (e.g., distillation, etc.) may be used to separate the distillates.
In one embodiment, the feed material includes at least approximately 85 wt % heavy hydrocarbon material, at least approximately 98 wt % heavy hydrocarbon material, or, desirably, at least approximately 99 wt % heavy hydrocarbon material. It should be appreciated that in other embodiments, the feed material may include a substantial amount of distillates.
The feed material is preheated before it enters the nozzle reactor 100, 200 to a temperature that is just below the temperature at which cracking occurs. This imparts the maximum amount of energy to the feed material without initiating cracking. In one embodiment, the heavy hydrocarbon material is heated to a temperature that is no more than 400° C. In another embodiment, the heavy hydrocarbon material is heated to at least approximately 350° C. In yet another embodiment, the heavy hydrocarbon material is heated to approximately 350° C. to approximately 400° C.
The cracking fluid can be any material that when combined with the feed material in the reactor 100, 200 cracks the heavy hydrocarbon material and/or serves as a hydrogen donor to the heavy hydrocarbon material. The cracking fluid may be supplied as a superheated fluid. Suitable cracking fluids include steam, natural gas, methanol, ethanol, ethane, propane, other gases, or combinations thereof. In one embodiment, the cracking fluid is superheated steam, natural gas, or a combination of both.
The cracking fluid helps prevent the formation of coke in the nozzle reactor 100, 200 by functioning as a hydrogen donor for the cracking reactions. The hydrogen from the cracking fluid is transferred to the heaviest hydrocarbons thereby preventing them from becoming hydrogen depleted in the extreme conditions of the nozzle reactor 100, 200.
The cracking fluid may be heated and pressurized before it is introduced to the first reactor 102. The heat and pressure provide added energy that is transferred to the heavy hydrocarbon material causing it to crack or scission. The cracking fluid may be provided in an amount and at a temperature sufficient to heat the heavy hydrocarbon material to the desired temperature and initiate the cracking reactions. The amount of heat supplied in the cracking fluid can be determined using a mass and energy balance.
In one embodiment, the cracking fluid is supplied at a temperature of at least approximately 550° C. or at least approximately 600° C. In another embodiment, the cracking fluid is supplied at a temperature of approximately 550° C. to approximately 700° C. or approximately 600° C. to approximately 650° C. In yet another embodiment, the cracking fluid is supplied at a temperature of no more than approximately 700° C.
In one embodiment, the cracking fluid is pressurized to at least approximately 1380 kPa or at least approximately 3100 kPa. In another embodiment, the cracking fluid is pressurized to approximately 1380 kPa to approximately 6200 kPa or approximately 3100 kPa to approximately 5170 kPa. In yet another embodiment, the cracking fluid is pressurized no more than approximately 6200 kPa or no more than approximately 5170 kPa.
The ratio of cracking fluid to feed material supplied to the nozzle reactor 100, 200 varies depending on a number of factors. In general, it is desirable to minimize the amount of cracking fluid to reduce cost while still successfully cracking the heavy hydrocarbon material. In one embodiment, the ratio of cracking fluid to heavy hydrocarbon material is no more than 2.0 or no more than 1.7. In another embodiment, the ratio of cracking fluid to heavy hydrocarbon material may be approximately 0.5 to approximately 2.0 or approximately 1.0 to approximately 1.7. In yet another embodiment, the ratio of cracking fluid to heavy hydrocarbon material is at least approximately 0.5 or at least approximately 1.0
The cracking produced in the nozzle reactor is influenced by a number of factors such as temperature, residence time, pressure, and impact force. Without wishing to be bound by theory, it appears that the mechanical forces exerted on the heavy hydrocarbon material due to the impact of the cracking fluid are a significant factor in the success of the nozzle reactor 100, 200. The impact force directly cleaves the molecule apart and/or weakens it making it more susceptible to chemical attack.
The feed material, which includes the heavy hydrocarbon material, is injected into the nozzle reactor via the feed passage 108. The feed material may be pretreated prior to entering the nozzle reactor 10 to alter the amount or fraction of heavy hydrocarbon material. The feed material may also be pretreated to alter its other characteristics as well.
In one embodiment, the feed material includes the heavy fraction from a separation unit. For example, a raw feed may be separated using a distillation column and the heavy fraction sent to the nozzle reactor 100, 200. The effluent produced by the nozzle reactor 100, 200 can be added to the raw feed and separated from any remaining heavy hydrocarbon material in the same separation unit used to provide the heavy hydrocarbon material.
The heavy hydrocarbon material and the cracking fluid are simultaneously injected into the nozzle reactor 100, 200 through the feed passage 108 and the main passage 106, respectively. The configuration of the main passage 106 is such that the cracking fluid is accelerated to supersonic speed and enters the interior chamber 146 at supersonic speed. The cracking fluid produces shock waves that facilitate mechanical and chemical scission of the heavy hydrocarbon material. In this manner, the heavy hydrocarbon material is broken down into distillates.
The nozzle reactor's conversion rate of heavy hydrocarbon material into distillates varies depending on the inputs, conditions, and a number of other factors. In one embodiment, the conversion rate of the nozzle reactor 100, 200 is at least approximately 2%, at least approximately 4%, or, desirably, at least approximately 8%. In another embodiment, the conversion rate of the nozzle reactor 100, 200 is approximately 2% to 25%, approximately 4% to 20%, or, desirably, approximately 8% to 16%.
The nozzle reactor 100, 200 cracks the heavy hydrocarbon material to produce lighter, lower molecular weight hydrocarbons. In one embodiment, the heavy hydrocarbon material is broken down into light hydrocarbon liquid distillate. The light hydrocarbon liquid distillate includes hydrocarbons having a molecular weight less than about 300 Daltons. In certain embodiments, about 25% to about 50% of the heavy hydrocarbon material cracked in the system 100 is converted into distillates.
As already mentioned above, one significant advantage of the nozzle reactor 100, 200 is that it produces very little, if any, coke and minimizes the amount of gas generated. This makes it possible to operate the nozzle reactor 100, 200 for long periods of time without cleaning. In one embodiment, the nozzle reactor 100, 200 may be operated indefinitely. Minimizing coke production also means that more of the heavy hydrocarbon material is conserved so that it can be used to produce higher value products than coke.
It should be appreciated that some portion of the heavy hydrocarbon material may pass through the system 100 without being cracked. This material may be referred to as non-participating heavy hydrocarbons or uncracked heavy hydrocarbons, since the nozzle reactor 100, 200 did not act on this material to crack it into lighter hydrocarbons. Heavy hydrocarbon material that is cracked but still qualifies as heavy hydrocarbon material may also be referred to as non-participating heavy hydrocarbons.
The effluent from the nozzle reactor 100, 200 may be transported to a separation unit that separates it into its constituent fractions. The separation unit may be any suitable separator capable of separating the effluent. Examples of suitable separation units include, but are not limited to, atmospheric or vacuum distillation units, gravity separation units, filtration units, and cyclonic separation units.
The non-participating hydrocarbons may be subjected to further processing to upgrade them into more useful material. Various types of processing may be performed on the non-participating hydrocarbon for upgrading the non-participating hydrocarbon. The remaining fractions may be used as end products or be subjected to further processing.
Depending on the situation, it may not be necessary to crack all of the heavy hydrocarbon material in the heavy hydrocarbon material. It may only be necessary to upgrade a portion of the heavy hydrocarbon material to produce stable products such as synthetic crude oil, which can include some amount of heavy hydrocarbon material.
Three injection hole shapes having the same equivalent flow area were studied.
The mixing index (M) for each injection hole shape was determined and plotted in terms of axial travel distance. The mixing index M generally defines the mixing of feed material with the surrounding reacting material. The higher the mixing index M, the greater the ability the injection hole has to transfer the jet of feed material off the centerline and distribute it uniformly in the space (i.e., the better the mixing performance).
The results of the mixing performance between the feed material and reacting material for the three shapes are shown in
At x/D=4, the mixing index of the cross-shaped injection hole doubles that of the clover-shaped injection hole and the clover shaped injection hole is two times better than conical nozzle. Even in the far field, the cross-shaped injection hole has a mixing index that is 71%˜115% higher than the clover-shaped injection hole. This result provides support to the conclusion that the cross-shaped injection hole has better mixing performance than the clover and conical shaped shaped injection holes.
The entrainment of the feed material in the surrounding reacting material was also studied for each injection hole shape. The results of the entrainment study are shown in
Entrainment in the area near the injection holes for the non-circular injection holes is 4 times higher than for the circular injection hole. At x/D=2, the cross-shaped injection hole entrains at least 5 times more air (by volume) into the feed material than the circular injection hole, and 4 times more at x/D=4. The clover-shaped injection hole entrains about twice as much as the circular injection hole in the near field, though only half of what the cross-shaped injection hole entrains at the same near field distance.
Improvements in entrainment can be due to at least the jet spread and shear layer thickness resulting from the use of the non-circular injection holes. The large-scale streamwise vortices are also believed to be responsible for the enhanced entrainment. Higher entrainment efficiency would allow more uniform and earlier mixing of feed material droplets with the reacting material. This would enable enhanced thermal and kinetic interaction between streams and result in break-up of larger molecules (such as asphaltenes when the feed material is bitumen-based material) into small molecules. In the context of upgrading bitumen material, the improved conversion results in the production of higher amount of distillate products.
The terms recited in the claims should be given their ordinary and customary meaning as determined by reference to relevant entries (e.g., definition of “plane” as a carpenter's tool would not be relevant to the use of the term “plane” when used to refer to an airplane, etc.) in dictionaries (e.g., widely used general reference dictionaries and/or relevant technical dictionaries), commonly understood meanings by those in the art, etc., with the understanding that the broadest meaning imparted by any one or combination of these sources should be given to the claim terms (e.g., two or more relevant dictionary entries should be combined to provide the broadest meaning of the combination of entries, etc.) subject only to the following exceptions: (a) if a term is used herein in a manner more expansive than its ordinary and customary meaning, the term should be given its ordinary and customary meaning plus the additional expansive meaning, or (b) if a term has been explicitly defined to have a different meaning by reciting the term followed by the phrase “as used herein shall mean” or similar language (e.g., “herein this term means,” “as defined herein,” “for the purposes of this disclosure [the term] shall mean,” etc.). References to specific examples, use of “i.e.,” use of the word “invention,” etc., are not meant to invoke exception (b) or otherwise restrict the scope of the recited claim terms. Other than situations where exception (b) applies, nothing contained herein should be considered a disclaimer or disavowal of claim scope. The subject matter recited in the claims is not coextensive with and should not be interpreted to be coextensive with any particular embodiment, feature, or combination of features shown herein. This is true even if only a single embodiment of the particular feature or combination of features is illustrated and described herein. Thus, the appended claims should be read to be given their broadest interpretation in view of the prior art and the ordinary meaning of the claim terms.
As used herein, spatial or directional terms, such as “left,” “right,” “front,” “back,” and the like, relate to the subject matter as it is shown in the drawing figures. However, it is to be understood that the subject matter described herein may assume various alternative orientations and, accordingly, such terms are not to be considered as limiting. Furthermore, as used herein (i.e., in the claims and the specification), articles such as “the,” “a,” and “an” can connote the singular or plural. Also, as used herein, the word “or” when used without a preceding “either” (or other similar language indicating that “or” is unequivocally meant to be exclusive—e.g., only one of x or y, etc.) shall be interpreted to be inclusive (e.g., “x or y” means one or both x or y). Likewise, as used herein, the term “and/or” shall also be interpreted to be inclusive (e.g., “x and/or y” means one or both x or y). In situations where “and/or” or “or” are used as a conjunction for a group of three or more items, the group should be interpreted to include one item alone, all of the items together, or any combination or number of the items. Moreover, terms used in the specification and claims such as have, having, include, and including should be construed to be synonymous with the terms comprise and comprising.
Unless otherwise indicated, all numbers or expressions, such as those expressing dimensions, physical characteristics, etc. used in the specification (other than the claims) are understood as modified in all instances by the term “approximately.” At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the claims, each numerical parameter recited in the specification or claims which is modified by the term “approximately” should at least be construed in light of the number of recited significant digits and by applying ordinary rounding techniques. Moreover, all ranges disclosed herein are to be understood to encompass and provide support for claims that recite any and all subranges or any and all individual values subsumed therein. For example, a stated range of 1 to 10 should be considered to include and provide support for claims that recite any and all subranges or individual values that are between and/or inclusive of the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more and ending with a maximum value of 10 or less (e.g., 5.5 to 10, 2.34 to 3.56, and so forth) or any values from 1 to 10 (e.g., 3, 5.8, 9.9994, and so forth).
The entire contents of the following documents are incorporated by reference herein: U.S. Pat. No. 7,618,597, titled “Nozzle Reactor and Method of Use,” issued on 17 Nov. 2009 (the '597 patent), U.S. Pat. No. 7,927,565, titled “Nozzle Reactor and Method of Use,” issued on 19 Apr. 2011 (the '565 patent), and U.S. application Ser. No. 13/277,470. In the event of a conflict, the subject matter explicitly recited or shown herein controls over any subject matter incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61596826 | Feb 2012 | US |
