Patent Description:
<CIT> describes a petroleum feedstock upgrading method. The method includes supplying a mixed stream that includes hydrocarbon feedstock and water to a hydrothermal reactor where the mixed stream is maintained at a temperature and pressure greater than the critical temperatures and pressure of water in the absence of catalyst for a residence time sufficient to convert the mixed stream into a modified stream having an increased concentration of lighter hydrocarbons and/or concentration of sulfur containing compounds. The modified stream is then supplied to an adsorptive reaction stage charged with a solid adsorbent operable to remove at least a portion of the sulfur present to produce a trimmed. The trimmed stream is then separated into a gas and a liquid streams, and the liquid stream is separated into a water stream and an upgraded hydrocarbon product stream.

Yellow wax and black wax petroleum crude oils exhibit high-pour-points (greater than <NUM>°F) and are semi-solid at ambient temperatures. While there are large waxy crude resources in the state of Utah, waxy crudes are produced in other regions of the United States and throughout the world. Waxy crude oils present severe transportation and logistics problems. Waxy crude oils can only be transported via insulated tank trucks to locations within a few hours of the oil field. Transportation to markets outside the local area requires heated trucks or rail cars, or heated pipelines. Heated waxy crude oils present a safety problem since they exhibit flash points close to their pour point. In Utah, waxy crudes are transported by insulated trucks to local refineries. This creates logistics, safety, and health issues due to the large volume of trucks required to travel over mountainous terrain, by secondary roads, near drinking water reservoirs, and through populated areas.

Solutions to transportation problems have focused mostly on the use of additives to reduce the pour point. However, these approaches have not been able to reduce the pour point sufficiently to permit use of conventional, unheated, transportation systems, such as tank truck, rail, pipeline, and the like. Dilution with other crude oils is another potential solution, but acceptable concentrations of waxy crude oils are very low, which creates logistic, production, and economic issues.

Refining waxy crudes present additional challenges and require changes in current refinery operations and equipment. A waxy crude usually consists of a variety of light and intermediate hydrocarbons and wax, which primarily consists of paraffin hydrocarbons (C18-C50+), known as paraffin wax, and a variety of other heavy organic compounds that include resins and asphaltenes. As used herein, hydrocarbon molecules may be defined by the number of carbon atoms. For example, any hydrocarbon molecule having eighteen carbon atoms is termed as a C18 and a hydrocarbon molecule having <NUM> carbon atoms is termed as a C50. Even though waxy crudes typically exhibit high API gravities, characteristics of light crude oils, the fraction of crude that boils higher than diesel, i.e., the fraction that distills at an atmospheric equivalent temperature (AET) greater than <NUM>°F (<NUM>), is much greater than typical crude oils that exhibit much lower API gravity. The fraction that boils at <NUM>°F to <NUM>°F (<NUM> to <NUM>) is defined as vacuum gas oil (VGO) and the fraction that boils at greater than <NUM>°F (<NUM>) is defined as residuum (resid). The VGO fraction of waxy crude oils is typically greater than <NUM>% of the crude. This presents a problem for conventional refineries designed to process crude oil that may only contain <NUM>-<NUM>% VGO and resid. In conventional petroleum refining, the VGO fraction is the overhead fraction from a vacuum distillation tower. The VGO fraction may be cracked into distillate fuels (<<NUM>°F / < <NUM>) using conventional hydrocracking or Fluid Catalytic Cracking (FCC) technology. As used herein, reference to a fraction by a temperature value or range (such as "<<NUM>°F" / < <NUM>) means that fraction boils at that temperature or range. However, the high VGO content of waxy crudes creates a severe bottleneck in the typical petroleum refinery. The conventional solution to this bottleneck is the addition of very expensive vacuum distillation and hydrocracking or FCC systems.

Due to the logistic, safety, and refining issues associated with waxy petroleum crude oils, the value of these crudes is depressed by as much as <NUM>% relative to other benchmark crude oils, such as West Texas Intermediate (WTI). Large deposits of waxy crude oils are not considered "proven reserves" because they are not recoverable with existing equipment and under the existing conditions. If waxy crude oils could be upgraded to allow transportation by unheated trucks, railcars, and pipelines, and the VGO content was reduced to permit maximum throughput in typical refineries without modification, the value of these crude oils would exceed the value of WTI. In addition, as "proven reserves," financing for additional waxy crude production infrastructure would then become readily available.

In addition to waxy crude oils, other materials exhibit similar transportation problems. Heavy oils and bitumen-type materials exhibit high viscosities and must be processed near the field to reduce viscosity or be diluted with a light crude oil or naphtha to permit transportation by pipeline. Synthetic hydrocarbons, such as wax produced by the Fischer-Tropsch (FT) process, exhibit even higher melting and pour points than waxy crude oils. Wellhead gas and stranded gas represent problems to oil and gas production that can be addressed by conversion into FT wax in the field. However, the transportation of solid wax is cost prohibitive due to logistic and refining issues. The ability to convert FT wax into liquid hydrocarbons in the field would greatly improve the logistics, economics, and technical viability of FT wax production and conversion.

The present invention is a process for converting a high-pour-point organic feedstock, as defined in the appended claims, that uses a continuous-flow, high-rate, hydrothermal reactor for converting high-pour-point and high viscosity organic feedstocks, such as waxy crudes or FT wax, into upgraded or synthetic crude oils (syncrude) that exhibit reduced pour point and viscosity. Hydrothermal pour point reduction upgrades hydrocarbon feedstocks in a process that combines high-temperature, supercritical water with the organic feedstock at conditions that result in rapid cracking of paraffinic molecules while minimizing the formation of coke and gas. The residence time in the high-rate hydrothermal reactor is less than <NUM> minute. In the case of a feedstock like yellow wax crude oil, the upgraded product exhibits a pour point reduction from <NUM> (<NUM>°F) to less than <NUM> (<NUM>°F) and VGO fraction reduction from <NUM>% to <NUM>%. In addition, diesel fuel fractions up to <NUM>% may be realized.

This invention takes advantage of the energy in the hydrothermal reactor product stream to perform atmospheric-pressure separation of process streams and achieve high thermal efficiency by integration of heat generation, reaction, and recovery processes. The small amount of byproduct gas generated during upgrading is sufficient to provide all the heat requirements for the process. The API gravity of the product is higher than the feedstock, which results in high volumetric yields - from <NUM> to <NUM>%. No byproducts or organic waste products are generated for some embodiments of the invention and over <NUM>% of the processed water may be recycled.

This invention has numerous advantages over other hydrothermal upgrading processes, conventional refinery upgrading processes, or other methods that include dilution and/or the use of additives. A summary of the advantages for waxy crude upgrading include, but are not limited to: <NUM>) hydrothermal cracking of paraffinic feedstocks without the need for hydrogen, vacuum distillation, hydrocracking, or fluid catalytic cracking (FCC) unit operations; <NUM>) very short residence time (><NUM> minute) resulting in very small process equipment that can be co-located with a conventional refinery or implemented near oil fields; <NUM>) low capital cost resulting from small equipment and system footprint, no catalyst requirement, and no hydrogen generation equipment; <NUM>) low operating cost resulting from no additional energy requirement for process heat, no catalyst replacement cost, no additive requirement, minimal waste and byproduct generation, and minimal water use and treatment costs; <NUM>) use of high-energy process streams containing water for product separation which eliminates the need for conventional vacuum distillation; and <NUM>) production of high yields of upgraded crude with a pour point below <NUM>°F (<NUM>), viscosity below <NUM> centistokes (cSt) @ <NUM> (<NUM>°F), VGO fraction less than <NUM>%, and high diesel fuel yield.

Waxy crude oils and whole FT wax products contain naphtha and diesel fractions that do not require upgrading. The distillate fraction may be separated by conventional distillation to reduce the amount of crude that requires processing. In an alternative approach, in accordance with the present invention, the high-energy reactor effluent stream may be used to strip the distillate fraction of the virgin feedstock in a separation system to cause a lighter, distillate fraction of the feedstock to be separated from the heavier fraction along with upgraded crude distillate. The heavier fraction (><NUM>°F / > <NUM>)) of the crude feedstock and unconverted product may then be further upgraded into distillate in the high-rate, hydrothermal reactor system. Separation systems may include one or more flash drums, one or more distillation or rectifying columns, one or more condensers, and one or more oil-water separators. The energy provided by the product stream is sufficient to permit low pressure operation of the separation systems and negate the need for vacuum distillation.

Some crude oils contain significant levels of asphaltenes or exhibit a high Conradson Carbon Residue (CCR). The industry standard for processing of VGO-type material has a CCR value of approximately <NUM>%. Accordingly, crude oils that exhibit a high CCR would be greater than <NUM>% and crude oils that exhibit a low CCR would be less than about <NUM>%. These oils may require separation of the residuum fraction to improve processability. According to another embodiment of this invention, the heavy fraction (><NUM>°F / > <NUM>) of the feedstock may be subjected to deasphalting processes to remove the asphaltenes before being upgraded in the high-rate hydrothermal reactor. An alternative approach is to employ vacuum distillation of the heavy fraction to remove asphaltenes in the bottoms (asphalt) fraction and provide a VGO-equivalent intermediate product for further upgrading.

In accordance with the present invention, a continuous flow process for converting a high-pour-point organic feedstock to an upgraded product is provided according to any of claims <NUM>-<NUM>.

When the upgraded heavy fraction is fed into the separation system, the high rate hydrothermal reactor system is capable of transferring a predetermined amount of energy to the heavy fraction such that when the upgraded heavy fraction is fed into the separation system, the predetermined amount of energy is sufficient to effect separation of the distillate fraction and the heavy fraction.

The process further includes mixing the heavy fraction from the separation system with one of a water and water-oil mixture to produce a heavy fraction mixture and feeding the heavy fraction mixture into the high rate hydrothermal reactor system. The process also includes providing one or more separators associated with the distillate fraction or the upgraded heavy fraction for recovering water for recycling and combining with the heavy fraction.

The process also includes maintaining a temperature and pressure of the water and heavy fraction mixture in the high-rate reactor system for sufficient time to produce an upgraded heavy fraction that has a low-pour-point.

The high-pour-point organic feedstock can be any feedstock that exhibits pour points greater than <NUM> (<NUM>°F) and is selected from the group consisting of heavy crude oil, tar sands bitumen, shale oil, waxy crude oils including yellow wax and black wax, petroleum oil fractions, synthetic crudes, such as wax from a Fischer-Tropsch (FT) process, and mixtures thereof.

The separation system can be operated at net positive pressure of <NUM> psig (<NUM>,<NUM> MPa) to <NUM> psig (<NUM>,<NUM> MPa) and can comprise at least one of one or more flash drums, one or more rectification columns, one or more distillation columns, or any combination thereof.

The process can further include depressurizing the upgraded heavy fraction exiting from the high-rate hydrothermal reactor system, filtering the depressurized upgraded heavy fraction, partially cooling the filtered depressurized heavy fraction in a feed-effluent heat exchanger, and feeding the partially cooled heavy fraction to a flash drum where a bottoms portion that contains refractory compounds is combined with the distillate fraction from the separation system to form the upgraded product.

The process further includes providing one or more condensers to condense the distillate fraction from the separation system to produce fuel gas and a reflux stream, wherein a first portion of the reflux stream is fed into the separation system and a second portion of the reflux stream is combined with a portion of the upgraded heavy fraction from the high-rate hydrothermal reactor to produce the upgraded product without any liquid byproducts.

The process can also include a step of treating the heavy fraction exiting from the separation system to a deasphalting process to remove coke precursors from feedstocks exhibiting high Conradson Carbon Residue (CCR) before the heavy fraction is fed to the high-rate reactor system. It can be appreciated that the deasphalting process can be any known process, such as a solvent deasphalting process, vacuum distillation, and the like.

According to one aspect of the invention, the water-to-oil weight ratio in the high-rate hydrothermal reactor system can be between <NUM>:<NUM> and <NUM>:<NUM> or even between <NUM>:<NUM> and <NUM>:<NUM>. The heavy fraction and oil-water mixture can be heated in the high-rate hydrothermal reactor system to a temperature between <NUM> (<NUM>°F) and <NUM> (<NUM>°F) or even to a temperature between <NUM> (<NUM>°F) and <NUM> (<NUM>°F). Additionally, the pressure in the high-rate hydrothermal reactor system can be maintained between <NUM> psig ( <NUM>,<NUM> MPa) and <NUM> psig (<NUM>,<NUM> MPa) or even between <NUM> psig (<NUM>,<NUM> MPa) and <NUM> psig (<NUM>,<NUM> MPa). Also, the high-rate hydrothermal reactor system residence time at operating conditions can be less than <NUM> minute.

The process further includes depressurizing the upgraded heavy fraction exiting the high-rate hydrothermal reactor system, filtering the depressurized upgraded heavy fraction, feeding the filtered upgraded heavy fraction to a feed-effluent heat exchanger, cooling the filter upgraded heavy fraction, feeding the cooled upgraded heavy fraction to one or more separators to remove fuel gas and water therefrom, and combining the upgraded heavy fraction exiting the one or more separators with the distillate fraction to form the upgraded product without the production of liquid byproducts. This process can also include the step of treating the heavy fraction from the separation system in a deasphalting process to remove coke precursors from feedstocks exhibiting high CCR before the heavy fraction is fed to the high-rate reactor system and wherein the deasphalting process comprises a known deasphalting process, such as solvent deasphalting process, vacuum distillation, and the like.

As used herein, unless otherwise expressly specified, all numbers such as those expressing values, ranges, amounts, or percentages may be read as if prefaced by the work "about", even if the term does not expressly appear. Plural encompasses singular and vice versa. For example, while the invention has been described in terms of "a" polyester stabilizer, "an" ethylenically unsaturated monomer, "an" organic solvent, and the like, mixtures of these and other components, including mixtures of microparticles, can be used. When ranges are given, any endpoints of those ranges and/or numbers within those ranges can be combined with the scope of the present invention. "Including", "such as", "for example" and like terms mean "including/such as/for example but not limited to".

For purposes of the description hereinafter, the terms "upper", "lower", "right", "left", "vertical", "horizontal", "top", "bottom", "lateral", "longitudinal", and derivatives thereof, shall relate to the invention as it is oriented in the drawing figures.

It should be understood that any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of "<NUM> to <NUM>" is intended to include any and all sub-ranges between and including the recited minimum value of <NUM> and the recited maximum value of <NUM>, that is, all sub-ranges beginning with a minimum value equal to or greater than <NUM> and ending with a maximum value equal to or less than <NUM>, and all sub-ranges in between, e.g., <NUM> to <NUM>, or <NUM> to <NUM>, or <NUM> to <NUM>.

The present invention is directed to an improved feedstock upgrading process for upgrading high-pour-point high viscosity feedstocks with a pour point temperature greater than <NUM> (<NUM>°F), such as waxy crudes, Fischer-Tropsch (FT) wax, heavy crude oil, or bitumen into an upgraded product having a lower viscosity and lower pour point in which the product can be transported in unheated trucks, rail cars, and pipelines. The present invention can also be used to convert other feedstocks including shale oil, petroleum oil fractions, synthetic crudes, and mixtures thereof. The process results in significantly increased yield of distillate (<<NUM>°F or < <NUM> ) and reduced VGO and residuum content (><NUM>°F or ><NUM>). The process relies on a high-rate hydrothermal reactor system that selectively cracks high molecular weight paraffin waxes in supercritical water to minimize coke and gas formation. Energy from the reactor effluent is employed to separate the distillate fraction of the feedstock and reactor effluent from unreacted and virgin heavy fraction that is further upgraded in the high-rate hydrothermal reactor system. Operation in this manner results in high energy efficiency, conversion at relatively mild conditions, high product yields, and a smaller high-rate reactor system since it is designed to treat only a fraction of the virgin feedstock. Other advantages of processing only the heavy fraction of the high-pour-point feedstock include reduction in the size of high-pressure equipment, reduction in the size of deasphalting equipment (if required), elimination of the need for vacuum distillation, low energy consumption, low fuel gas and waste generation, and improved oil/water separation, which permits maximum water recovery and reuse.

Reference is now made to <FIG>, wherein virgin high-pour-point feedstock that exhibits a low Conradson Carbon Residue (CCR) (i.e., less than <NUM>%) is combined directly with upgraded bottoms effluent from the high-rate hydrothermal reactor system in a separation system or rectifying column. In this embodiment, energy from reactor effluent is transferred directly to the virgin feedstock to vaporize the distillate fraction and cool the reactor effluent to condense the heavy fraction. The distillate fraction of the virgin feedstock and the distillate fraction of the upgraded heavy fraction are recovered in the overhead stream. The heavy fraction (><NUM>°F or ><NUM>) of the virgin feedstock and the heavy fraction remaining after conversion in the high-rate hydrothermal reactor system are recovered in the bottom stream. Since the uncracked heavy fraction is recycled to the high-rate reactor, a mechanism is provided to remove a small slipstream of the heavy fraction refractory compounds to prevent buildup of these compounds in the process. The slipstream is combined with the distillate fraction to form the upgraded product. Benefits of the direct contact approach include: <NUM>) direct heat transfer in the separation system and corresponding reduction in heat exchanger requirements; <NUM>) recycle of uncracked high molecular weight paraffin waxes to the high-rate hydrothermal reactor; <NUM>) less severe operating conditions as a result of recycling uncracked product; and <NUM>) high distillate yield and low gas and VGO yield.

In <FIG>, only the low CCR virgin feedstock is split in the rectifying column into a distillate fraction and heavy fraction that is then fed directly to the high-rate hydrothermal reactor system. The feedstock is heated indirectly by heat exchange with other process streams. High-rate hydrothermal reactor effluent is cooled, separated from fuel gas and water, and combined in its entirety with the distillate fraction to form an upgraded product. Benefits of the indirect contact approach include: <NUM>) smaller high-rate reactor and separation systems; <NUM>) simplified design and operation; and <NUM>) low bromine number of the heavy fraction that will reduce the rate of coke formation in the high-rate reactor system.

<FIG> and <FIG> are directed to feedstocks that exhibit a high CCR (i.e., greater than <NUM>%). CCR provides an indication of the relative coke-forming propensity of hydrocarbon feedstocks. Feedstocks exhibiting high CCR must be processed to reduce CCR before processing in high-temperature equipment - fired furnaces, heat exchangers, etc. CCR can be reduced by conventional solvent deasphalting or vacuum distillation. Both of these processes result in a small slipstream high in asphaltenes compounds. This stream may be added to the upgraded product depending on product specifications and feedstock quality.

Reference is now made to <FIG>, which shows a schematic view of the pour point reduction process, generally indicated as <NUM>, in accordance with the invention, for converting high-pour-point, low CCR feedstock into an upgraded product. The process includes providing an organic, high-pour-point feedstock <NUM>. The crude feedstock <NUM> may be fed into an equalization tank <NUM>. Generally, an equalization tank acts as a holding tank that allows for the equalization of flow of the feedstock. An equalization tank can also act as a conditioning operation where the temperature of the feedstock is controlled to maintain the proper flow characteristics. The high-pour-point feedstock <NUM> exits the equalization tank <NUM> and is fed into pump <NUM> to form a pressurized feed stream <NUM> at sufficient pressure to prevent formation of gaseous hydrocarbons during subsequent heating. The pressurized feed stream <NUM> can be heated by a heating device, such as a heat exchanger <NUM> to form a heated feed stream <NUM> that may be further heated by a feed-effluent heat exchanger <NUM> to form a further heated feed stream <NUM>. It can be appreciated that the pressurized feed stream <NUM> and heated feed stream <NUM> can be heated by any known process or device and may include exchange with other process streams to optimize overall thermal efficiency.

The further heated feed stream <NUM> of the high-pour-point feedstock is then fed through a pressure control valve or depressurizing device <NUM> to form a heated depressurized stream <NUM> which is then fed into a separation system. For purposes of the present disclosure, the separation system will be referred to as a rectification or rectifying column, and will be designated by reference numerals <NUM>, <NUM>, <NUM>, and/or <NUM> throughout the specification and drawings. However, it can be appreciated that the separation system can comprise at least one of one or more flash drums, one or more rectification columns, one or more distillation columns, or any combination thereof. Additionally, the separation system of the present disclosure is operated at a net positive pressure of <NUM> psig (<NUM>,<NUM> MPa) to <NUM> psig ( <NUM>,<NUM> MPA.

With continuing reference to <FIG>, the rectification column <NUM> produces a distillate fraction <NUM> and a heavy fraction <NUM>. The distillate fraction <NUM> is cooled and condensed in condenser <NUM> to form a condensed, cooled distillate product <NUM>. The distillate product <NUM> is fed into one or more separators. The cooled distillate product <NUM> is separated in a gas-liquid separator (GLS) <NUM> into a fuel gas <NUM> and an oil-water stream <NUM> which is fed into an oil-water separator <NUM>. The oil-water separator <NUM> produces a process water stream <NUM>, a distillate reflux <NUM>, and a distillate product <NUM>. The conditions of the rectification column are controlled to produce a distillate product that, when blended with the bottoms fraction <NUM> from flash drum <NUM> (described below), results in an upgraded product that meets required pour point and flow characteristics. Process water stream <NUM> may be recycled to a water feed equalization tank <NUM>. Water feed <NUM> exiting the equalization tank <NUM> and is fed into pump <NUM> where it is pressurized to form a high-pressure water stream <NUM>. The heavy fraction or bottoms product <NUM> from the rectifying column <NUM> is pressurized by pump <NUM> to form a pressurized stream <NUM> and combined with the high-pressure water stream <NUM> to form a heavy fraction and water pressurized feed stream <NUM>. While conventional mixing devices, such as mixing valves and static mixing elements may be employed, oil and water phases are completely miscible at process operating conditions. The heavy fraction and water pressurized feed stream <NUM> may be further heated by heat exchanger <NUM> to form a heated feed stream that is fed into the high-rate hydrothermal reactor system (or high-rate reactor) <NUM>.

One example of a high-rate hydrothermal reactor <NUM> that can be used is the high-rate reactor disclosed in application <CIT>. The high-rate reactor <NUM> is designed to improve reactor fluid dynamics and achieve higher operating temperatures such as operating temperatures between <NUM> and <NUM> (<NUM>°F and <NUM>°F), or between <NUM> and <NUM> (<NUM>°F and <NUM>°F) or even between <NUM> and <NUM> C (<NUM>°F and <NUM>°F). Because the high-rate reactor <NUM> operates at temperatures much higher than the prior art systems, the reaction rate is greatly increased and the residence time and reactor size are reduced. However, as the reaction temperature is increased, the potential for coke formation and gasification also increases. The high-rate reactor <NUM> mitigates the effects of high-temperature operation by employing a combination of features. One of these features includes management of water concentration to mitigate coke formation. The high-rate reactor <NUM> utilizes water-to-organic volume ratios between <NUM>:<NUM> and <NUM>:<NUM>, such as between <NUM>:<NUM> and <NUM>:<NUM>, and in the present invention, the water-to-oil weight ratio is between <NUM>:<NUM> and <NUM>:<NUM>, such as between <NUM>:<NUM> and <NUM>:<NUM>. The high-rate reactor typically uses rapid heating of the contents to reach the reaction temperature (such as heating rates of <NUM> to <NUM> (<NUM>°F to <NUM>°F) per second) and high pressure to mitigate excessive cracking and gas formation, (such as reaction pressure in the range of <NUM>-<NUM> psig (<NUM>,<NUM> - <NUM>,. <NUM> MPa), such as in the range of <NUM> psig (<NUM>,<NUM> MPa) to <NUM> psig (<NUM>,<NUM> MPa) or in the range of <NUM> psig (<NUM>,68MPa) and <NUM> psig (<NUM>,<NUM> MPa). The high-rate reactor <NUM> also utilizes the feature of turbulent flow to optimize mixing, maximize heat transfer, minimize reactor fouling, and suspend solids that form or precipitate. Yet another feature includes the use of a short residence time to minimize secondary cracking and coke formation. Superficial residence times from <NUM> to <NUM> seconds may be employed or even less than <NUM> minute. Rapid quenching may be employed to minimize secondary cracking, coke formation, undesirable secondary reactions, and corrosion. The quench can be accomplished by the addition of water or, in the present invention, quench can be accomplished by the addition of a high-pour-point feedstock.

The high-rate reactor <NUM> operates at a temperature which increases cracking, isomerization, reforming, dehydrocyclization, and dealkylation rates and achieve a very short residence time, but at a temperature much lower than utilized in conventional steam cracking reactors. By operating at lower temperatures than conventional steam cracking reactors, the present invention minimizes gas and coke formation. It can be appreciated that optimal conversion conditions are dependent on feedstock quality and operating conditions can be varied to achieve the desired product yield and chemistry. For example, when processing high-molecular-weight feedstocks, operating conditions can be varied to maximize the yield of diesel, kerosene, or naphtha, or to control the degree of cyclization and aromatization.

The high-rate reactor <NUM> can be a tubular reactor, with the inside diameter of the tube or tubes designed to maintain a turbulent flow of the mixture throughout a reaction zone. Turbulent flow occurs at a high Reynolds Number, i.e., the measure of the ratio of inertial force to viscous forces, and is dominated by inertial forces, which tend to produce chaotic eddies, vortices, and other flow instabilities. A high Reynolds Number results in a high heat transfer rate, intimate mixing, and reduces the rate of reactor fouling. A combination of a short residence time and a high Reynolds Number (Re) within the range of <NUM>-<NUM>,<NUM> or even higher than <NUM>,<NUM> throughout the reaction zone is used.

In the high-rate hydrothermal reactor system <NUM>, high molecular weight paraffin molecules are hydrothermally cracked into smaller molecules that exhibit lower pour point and lower viscosity. The upgraded heavy product or reactor effluent <NUM> is fed through a pressure control valve <NUM> where it forms a depressurized reactor effluent <NUM>. The depressurized reactor effluent <NUM> passes through a filter system <NUM> that may consist of conventional filtration systems, or simply a knockout drum. A filtered reactor effluent <NUM> is partially cooled in heat exchanger <NUM> to produce a partially-cooled reactor effluent stream <NUM>. Reactor effluent stream <NUM> is then fed into a flash drum <NUM> where a vapor portion <NUM> of the reactor effluent <NUM> is fed to the rectifying column <NUM> and the liquid bottoms portion <NUM> of the reactor effluent <NUM> is cooled by heat exchanger <NUM> to form cooled reactor effluent <NUM> which is then combined with distillate product <NUM> to form an upgraded product <NUM>. According to one embodiment, the high-rate hydrothermal reactor system <NUM> is capable of transferring a predetermined amount of energy to the heavy product <NUM> (such as heat and pressure) such that when the upgraded heavy product or reactor effluent <NUM> is fed into the separation system <NUM>, the predetermined amount of energy (i.e., the reactor effluent <NUM> is supplied at this predetermined temperature and pressure) is sufficient to effect or to supply enough energy to the rectification column <NUM> to cause separation of the distillate fraction <NUM> and the heavy fraction <NUM>. It can be appreciated that the proportion of reactor effluent vapor <NUM> and liquid bottoms <NUM> can be controlled by controlling the amount of heat removed by heat exchanger <NUM>. It can also be appreciated that the liquid bottoms portion <NUM> provides a slipstream to remove heavy refractory compounds from the reactor effluent stream <NUM> and that the volume and properties of bottoms <NUM> can be controlled to meet upgraded product specifications.

Reference is now made to <FIG>, which shows a schematic view of the high-pour-point crude conversion process, generally indicated as <NUM>, for converting the high CCR feedstock <NUM> into an upgraded product, which is configured to address feedstocks that exhibit high levels of CCR caused by constituents, such as asphaltenes or resins. The heavy fraction <NUM> from the rectifying column <NUM> is fed to a deasphalting system <NUM> to produce heavy fraction <NUM> that exhibits reduced concentrations of asphaltenes and resins. The deasphalting system <NUM> may be comprised of conventional solvent deasphalting systems or vacuum distillation. Both of these processes result in a small slipstream <NUM> that contains high levels of asphaltenes. Slipstream <NUM> may be produced as a separate byproduct that can be used as an asphalt blending component or a coker feedstock. Alternatively, slipstream <NUM> may be added to the upgraded product (not shown), as long as product specifications can be met.

With continuing reference to <FIG>, the process <NUM> includes providing the high CCR feedstock <NUM> into an equalization tank <NUM>. The high pour point feedstock <NUM> exits the equalization tank <NUM> and is then fed into pump <NUM> to form a pressurized feed stream <NUM> at sufficient pressure to prevent formation of gaseous hydrocarbons during subsequent heating. The pressurized feed stream <NUM> can be heated by a heating device, such as a heat exchanger <NUM> to form a heated feed stream <NUM> that may be further heated by a feed-effluent heat exchanger <NUM> to form a further heated feed stream <NUM>. As stated above, it can be appreciated that the pressurized feed stream <NUM> and heated feed stream <NUM> can be heated by any known process or device and may include exchange with other process streams to optimize overall thermal efficiency.

The further heated feed stream <NUM> of the high-pour-point feedstock is then fed through a pressure control valve or depressurizing device <NUM> to form a heated depressurized stream <NUM> which is then fed into the rectification or rectifying column <NUM>. The rectification column <NUM> produces a distillate fraction <NUM> and a heavy fraction <NUM>. As discussed above, the heavy fraction <NUM> is fed to the deasphalting system <NUM> to produce the heavy fraction <NUM> that exhibits reduced concentrations of asphaltenes and resins. The distillate fraction <NUM> is cooled and condensed in condenser <NUM> to form a condensed cooled distillate product <NUM>. The cooled distillate product <NUM> is fed into a gas-liquid separator (GLS) <NUM> wherein it is separated into a fuel gas <NUM> and an oil/water stream <NUM>, which is fed into an oil/water separator <NUM>. The oil/water separator <NUM> produces a process water stream <NUM>, a distillate reflux <NUM>, and a distillate product <NUM>. The conditions of the rectification column <NUM> are controlled to produce a distillate product that, when blended with the bottoms fraction <NUM> from flash drum <NUM>, results in an upgraded product that meets required pour point and flow characteristics. Process water stream <NUM> may be recycled to a water feed equalization tank <NUM>. Water feed <NUM> exits the equalization tank <NUM> and is fed into pump <NUM> where it is pressurized to form a high-pressure water stream <NUM>. The heavy fraction <NUM> from the deasphalting system <NUM> is pressurized by pump <NUM> to form a pressurized stream <NUM> and combined with the high-pressure water stream <NUM> to form a heavy fraction and water pressurized feed stream <NUM>. The pressurized feed stream may be further heated by heat exchanger <NUM> to form a heated feed stream <NUM> that is fed into the high-rate hydrothermal reactor system <NUM>.

As previously discussed, in the high-rate hydrothermal reactor system <NUM>, high molecular weight paraffin molecules are hydrothermally cracked into smaller molecules that exhibit lower pour point and lower viscosity. The reactor effluent <NUM> is fed through a pressure control valve <NUM> where it forms a depressurized reactor effluent <NUM>. The depressurized reactor effluent <NUM> passes through a filter system <NUM> that may consist of conventional filtration systems, or simply a knockout drum to form a filtered reactor effluent <NUM>. The filtered reactor effluent <NUM> is partially cooled in heat exchanger <NUM> to produce a partially-cooled reactor effluent stream <NUM>. Reactor effluent stream <NUM> is then fed into the flash drum <NUM> where the vapor portion <NUM> of the reactor effluent is fed to the rectifying column <NUM> and the liquid bottoms portion <NUM> of the reactor effluent <NUM> is cooled by heat exchanger <NUM> to form cooled reactor effluent <NUM> which is then combined with distillate product <NUM> to form upgraded product.

Reference is now made to <FIG>, which shows a schematic view of the pour point reduction process and system generally indicated as <NUM> for converting the high-pour-point, low CCR feedstocks into an upgraded product. The low CCR virgin feedstock <NUM> is fed into an equalization tank <NUM> to form the high-pour-point feedstock <NUM>, which is then fed into pump <NUM> to form a pressurized feed stream <NUM>, preheated in heat exchanger system <NUM> to form heated feed stream <NUM>, further heated in heat exchanger <NUM> to form a further heated feed stream <NUM>, and fed through a pressure control valve <NUM>, yielding feedstock stream <NUM> which is fed into the rectifying column <NUM>. Feedstock stream <NUM> is split into a distillate fraction <NUM> and heavy fraction <NUM>. Distillate fraction <NUM> is fed through heat exchanger <NUM> to form stream <NUM>, which is subsequently fed through a condenser or accumulator <NUM> to form fuel gas <NUM>. A first portion or reflux stream <NUM> from the fuel gas <NUM> is then fed back into rectifying column <NUM> to increase the separation of the phases therein and a second portion or distillate fraction <NUM> is combined with the reactor effluent <NUM> to form the upgraded product <NUM>. The heavy fraction <NUM> is pressurized by pump <NUM> to form a pressurized feed <NUM> which is combined with a high-pressure water feed stream <NUM> to form a heavy fraction and water pressurized feed stream <NUM>. The heavy fraction and water pressurized feed stream <NUM> may be further heated by heat exchanger <NUM> to form a heated feed stream <NUM> that is fed into the high-rate hydrothermal reactor system <NUM>.

A reactor effluent <NUM> is fed through a pressure control valve <NUM> where it forms a depressurized reactor effluent <NUM>. The depressurized reactor effluent <NUM> passes through a filter system <NUM> that may consist of conventional filtration systems, or simply a knockout drum. The filtered reactor effluent <NUM> may be cooled in heat exchanger <NUM> to produce a partially-cooled reactor effluent stream <NUM> that may be further cooled by heat exchanger <NUM>. It can be appreciated that sufficient heat is available in reactor effluent stream <NUM> to provide energy for rectification column <NUM> operation. It can also be appreciated that heat recovery may include exchange with other process streams to optimize overall thermal efficiency.

Cooled reactor effluent <NUM> is fed to gas liquid separator <NUM> to separate a fuel gas <NUM> from a liquid fraction <NUM> which is then fed to an oil-water separator <NUM> to separate water <NUM> from reactor effluent <NUM>. Processed water <NUM> may be recycled to the water equalization tank <NUM>. A water feed <NUM> exits the equalization tank <NUM> and is fed into pump <NUM> to form the high pressure water feed stream <NUM>. Reactor effluent <NUM>, which is the upgraded bottoms fraction, is combined with the distillate fraction <NUM> to form the upgraded product <NUM>.

Reference is now made to <FIG>, which shows a schematic view of the high-pour-point crude conversion process and system generally indicated as <NUM> for converting the high CCR feedstock <NUM> into an upgraded product, configured to address feedstocks that exhibit high levels of CCR caused by constituents, such as asphaltenes or resins. The heavy fraction <NUM> from the rectifying column <NUM> is fed to a deasphalting system <NUM> to produce a heavy fraction <NUM> that exhibits reduced concentrations of asphaltenes and resins. The deasphalting system <NUM> may be comprised of conventional solvent deasphalting systems or vacuum distillation. Both of these processes result in a small slipstream <NUM> that contains high levels of asphaltenes. Slipstream <NUM> may be produced as a separate byproduct that can be used as an asphalt blending component or a coker feedstock. Alternatively, slipstream <NUM> may be added to the upgraded product <NUM>, as long as product specifications can be met.

With continuing reference to <FIG>, the process and system <NUM> includes providing a high CCR feedstock <NUM> into an equalization tank <NUM>. The high-pour-point feedstock <NUM> exits equalization tank <NUM> and is then fed into pump <NUM> to form a pressurized feed stream <NUM> at sufficient pressure to prevent formation of gaseous hydrocarbons during subsequent heating. The pressurized feed stream <NUM> can be heated by a heating device, such as a heat exchanger <NUM> to form a heated feed stream <NUM> that may be further heated by a feed-effluent heat exchanger <NUM> to form a further heated feed stream <NUM>. As stated above, it can be appreciated that the pressurized feed stream <NUM> and heated feed stream <NUM> can be heated by any known process or device and may include exchange with other process streams to optimize overall thermal efficiency.

The further heated feed stream <NUM> of the high-pour-point feedstock is then fed through a pressure control valve or depressurizing device <NUM> to form a heated depressurized stream <NUM> which is then fed into the rectification column <NUM>. The rectification column <NUM> produces a distillate fraction <NUM> and a heavy fraction <NUM>. As discussed above, the heavy fraction <NUM> is fed to the deasphalting system <NUM> to produce the heavy fraction <NUM> that exhibits reduced concentrations of asphaltenes and resins. Similar to system <NUM> shown in <FIG>, the deasphalting system <NUM> may be comprised of conventional solvent deasphalting systems or vacuum distillation and both of these processes result in a small slipstream <NUM> that contains high levels of asphaltenes. Slipstream <NUM> may be produced as a separate byproduct that can be used as an asphalt blending component or a coker feedstock. Alternatively, the slipstream <NUM> may be added to the upgraded product <NUM>, as long as product specifications can be met.

A distillate fraction <NUM> is cooled and condensed in condenser <NUM> to form a condensed cooled distillate product <NUM>. The cooled distillate product <NUM> enters into a condenser or accumulator <NUM> to form fuel gas <NUM>. A first portion or reflux stream <NUM> from the fuel gas <NUM> is then fed back into rectifying column <NUM> to increase the separation of the phases therein and a second portion or distillate fraction <NUM> is combined with the reactor effluent <NUM>, as discussed in more detail below, to form the upgraded product <NUM>.

The heavy fraction <NUM> from the deasphalting system <NUM> is pressurized by pump <NUM> to form a pressurized stream <NUM> and combined with a high pressure water stream <NUM> to form a heavy fraction and water pressurized feed stream <NUM>. The pressurized feed stream may be further heated by heat exchanger <NUM> to form a heated feed stream <NUM> that is fed into the high-rate hydrothermal reactor system <NUM>.

A reactor effluent <NUM> is fed through a pressure control valve or depressurization device <NUM> where it forms a depressurized reactor effluent <NUM>. The depressurized reactor effluent <NUM> passes through a filter system <NUM> that may consist of conventional filtration systems, or simply a knockout drum to form a filtered reactor effluent <NUM>. The filtered reactor effluent <NUM> may be partially cooled in heat exchanger <NUM> to produce a partially-cooled reactor effluent stream <NUM>. Reactor effluent stream <NUM> is then fed into a heat exchanger <NUM> where it is further cooled. Cooled reactor effluent <NUM> is fed to a gas liquid separator <NUM> to separate fuel gas <NUM> from the liquid fraction <NUM> which is then fed to an oil-water separator <NUM> to separate water <NUM> from reactor effluent <NUM>. Process water <NUM> may be recycled to the water equalization tank <NUM>. A water feed <NUM> exits the equalization tank <NUM> and is fed into pump <NUM> to form the high-pressure water feed stream <NUM> which is combined with a pressurized stream <NUM> of the heavy fraction <NUM> from the deasphalting system <NUM>. Reactor effluent <NUM>, which is the upgraded bottoms fraction, is combined with the distillate fraction <NUM> to form the upgraded product <NUM>.

Example <NUM> - Pour point reduction of yellow wax crude oil.

Yellow wax crude oil from the Uinta Basin in Utah was the feedstock for a pilot demonstration of the pour point reduction process according to the system depicted in <FIG>. The yellow wax feedstock exhibited low CCR, a pour point of approximately <NUM> (<NUM>°F), and a specific gravity of <NUM> (API gravity = <NUM>). Table <NUM> provides the approximate composition of the feedstock by boiling points. The fraction that distilled below <NUM> (<NUM>°F) was approximately <NUM>% of crude feed and represented the low-pour-point, distillate fraction that did not require pour point reduction. The fraction that boiled above <NUM> was approximately <NUM>% of this crude and represented the heavy fraction that required pour point reduction via conversion in the high-rate hydrothermal reactor system.

For this example, a continuous-flow pilot system was configured, as shown in <FIG>. In this configuration, the feedstock (stream <NUM>) was fractionated into distillate (<NUM>) and heavy (<NUM>) fractions and the heavy fraction fed to the high-rate hydrothermal reactor system (<NUM>). The cooled distillate fraction (<NUM>) and cooled, upgraded heavy fraction (<NUM>) were then recombined to form the upgraded product (<NUM>). The nominal processing capacity of the pilot system was approximately <NUM> bbl/day (<NUM>/day). The distillation column for this process was a partially packed, <NUM>-inch (<NUM>,<NUM>) diameter by <NUM>-ft (<NUM>) column operated with reflux to improve separation of the distillate and heavy fractions. This column effectively separated the two fractions in accordance with the simulated distillation data shown in Table <NUM>, performed on a gas chromatograph indicating the temperature at which each fraction distilled. The data in Table <NUM> demonstrates that the distillate fraction primarily contained light products (boiling at <NUM> and below) while the heavy fraction primarily contained heavy products (boiling at <NUM> and above).

A summary of process stream flow rates and system operating conditions is provided in Table <NUM>. In this example, the actual heavy fraction was approximately <NUM>% (vol) of the feed. The volume ratio of water to oil in the combined feed (<NUM>) was <NUM>. The equivalent weight ratio of water to oil was <NUM>.

Table <NUM> provides a summary comparing the properties of the yellow wax feed and upgraded product.

The VGO fraction of the yellow wax feed was reduced from approximately <NUM>% to only <NUM>% in the upgraded product. The kerosene/diesel fraction was increased from approximately <NUM>% in the yellow wax feed to approximately <NUM>% in the upgraded product. Most importantly, pour point of the yellow wax feed was reduced from approximately <NUM> to less than <NUM>. It can be appreciated that, for any given feedstock, the proportion of distillate and heavy fractions and the operating conditions of the high-rate hydrothermal reactor may be manipulated to produce an upgraded product that exhibits any desired pour point.

In addition, pour point reduction may be accomplished with limited yield loss. In Example <NUM>, liquid product yield loss due to the production of fuels gas (<NUM> SCFB) equated to approximately <NUM>% by weight of the feedstock. However, since the specific gravity of the feedstock was <NUM> and the specific gravity of the product was <NUM>, the actual yield was approximately <NUM>% by volume.

Yellow wax crude oil from the Uinta Basin in Utah was the feedstock for a pilot demonstration of the pour point reduction process according to the system depicted in <FIG>. The yellow wax feedstock exhibited low Conradson Carbon Residue (CCR), a pour point of approximately <NUM> (<NUM>°F), and a specific gravity of <NUM> (API gravity = <NUM>). Table <NUM> provides the approximate composition of the feedstock by boiling point. The fraction that distilled below <NUM> (<NUM>°F) was approximately <NUM>% of crude feed and represented the low-pour-point, distillate fraction that did not require pour point reduction. The fraction that boiled above <NUM> (<NUM>°F) was approximately <NUM>% of this crude and represented the heavy fraction that did require pour point reduction via conversion in the high-rate hydrothermal reactor system.

A continuous-flow pilot system was configured, as shown in <FIG>. In this configuration, the feedstock (stream <NUM>) was co-fed with upgraded heavy fraction (<NUM>) into the rectification column (<NUM>) to produce a distillate fraction (<NUM>) and heavy fraction (<NUM>). The distillate fraction was cooled, condensed, and fuel gas and water separated to produce the primary distillate product (<NUM>). The distillate product represents the distillate fraction of the feedstock and the distillate fraction from the upgraded bottoms product. The heavy fraction (<NUM>) was comprised of the heavy fraction of the feedstock and the heavy fraction from unconverted bottoms product. Part of the heavy fraction from the high-rate reactor was produced as a slipstream (<NUM>). The bottoms fraction was then mixed with water and fed into the high-rate hydrothermal reactor system (<NUM>). The rectification column (<NUM>) for this process was a partially packed, <NUM>-inch diameter by <NUM>-ft column operated with reflux to improve separation of the distillate and heavy fractions.

A summary of process stream flow rates and system operating conditions for Example <NUM> is provided in Table <NUM>. The volume ratio of water to oil in the combined feed (<NUM>) was <NUM>. The equivalent weight ratio of water to oil was <NUM>.

Table <NUM> provides a summary comparing the properties of the yellow wax feed and upgraded product. The VGO fraction of the yellow wax feed was reduced from <NUM>% to only <NUM>% in the upgraded product. The kerosene/diesel fraction was increased from <NUM>% in the yellow wax feed to <NUM>% in the upgraded product. Most importantly, pour point of the yellow wax feed was reduced from approximately <NUM> to less than -<NUM>. It can be appreciated that, for any given feedstock, the proportion of distillate and heavy fractions and the operating conditions of the high-rate hydrothermal reactor may be manipulated to produce an upgraded product that exhibits any desired pour point.

Claim 1:
A continuous flow process for converting a high-pour-point organic feedstock to an upgraded product comprising:
providing a high-pour-point organic feedstock, wherein the high-pour-point organic feedstock has a pour point temperature greater than <NUM> (<NUM>°F);
feeding the high-pour-point organic feedstock into a separation system to produce a distillate fraction and a heavy fraction;
feeding the heavy fraction from the separation system into a high-rate hydrothermal reactor system operating at supercritical water conditions and a Reynolds Number (Re) within the range of <NUM> - <NUM>,<NUM>, wherein the heavy fraction is maintained in the reactor for a residence time of less than one minute to produce an upgraded heavy fraction; and
depressurizing the upgraded heavy fraction exiting the high-rate hydrothermal reactor system, filtering the depressurized upgraded heavy fraction, feeding the filtered upgraded heavy fraction to a feed-effluent heat exchanger, cooling the filtered upgraded heavy fraction, feeding the cooled filtered upgraded heavy fraction to one or more separators to remove fuel gas and water therefrom, and combining the upgraded heavy fraction exiting the one or more separators with the distillate fraction to form the upgraded product without the production of liquid byproducts.