EXTENDING DEWAXING CYCLE LENGTH

Info

Publication number: 20180171247
Type: Application
Filed: Dec 4, 2017
Publication Date: Jun 21, 2018
Inventors: Kathryn L. PERETTI (The Woodlands, TX), Mohsen N. Harandi (New Hope, PA)
Application Number: 15/830,418

Abstract

Methods are provided for dewaxing a distillate fuel boiling range feed to improve one or more cold flow properties of the distillate fuel feed, such as cloud point. The dewaxing can be performed in the presence of an olefin co-feed that allows for an increase in the average temperature for exposure of the feed to the dewaxing catalyst. If the dewaxing catalyst is included in a reactor that also includes other hydroprocessing catalyst(s), the olefin co-feed can optionally be introduced into the reactor at a location after the hydroprocessing catalyst bed(s) and prior to the dewaxing catalyst bed(s). Due to the relative ease of performing olefin saturation in the presence of a catalyst with a hydrogenation metal, a substantial portion of the olefins in an olefin co-feed (such as substantially all) can be converted to alkanes. Olefin saturation is exothermic, so the conversion of olefins to alkanes can provide a temperature increase for a feed as it is being exposed to catalyst in a catalyst bed.

Description

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 62/435,896, filed on Dec. 19, 2016, the entire contents of which are incorporated herein by reference.

FIELD

This invention provides methods for extending process cycle lengths when producing distillate fuels with improved cold flow properties.

BACKGROUND

In diesel hydroprocessing, it is sometimes beneficial to include a dewaxing stage as part of reaction train in order to improve properties of the resulting diesel fuel such as pour point or cloud point. Such improvements in cold flow properties can, for example, allow a diesel fuel to meet a desired specification for a diesel fuel pool, or the improvements can allow a diesel fuel to be suitable for a higher value use, such as use as a winter diesel fuel. While such improvements can be desirable, performing an additional dewaxing process on a diesel fuel product typically means that additional refinery resources are consumed in order to perform the process.

During hydroprocessing of a feed to form a distillate fuel, the cycle length for the hydroprocessing reactor can be related to the operating temperature of the reactor. Over the course of a hydroprocessing run, the hydrotreating and/or dewaxing catalysts within the reactor can experience some reduction in activity. To compensate for this, the temperature of the reactor can be increased to maintain one or more target properties for the hydroprocessed effluent. The end of a hydroprocessing run or cycle can often be based on when a maximum temperature for a hydroprocessing reactor is reached. The maximum temperature may be related to a maximum temperature that is desirable for processing of a feed, or the maximum temperature may be related to limitations or constraints on the reactor configuration.

U.S. Pat. No. 8,377,286 describes hydroprocessing methods for diesel fuel production. The methods include options for processing diesel fuel under sour conditions, such as in the presence of 100 wppm or more of sulfur. The dewaxing catalysts used for dewaxing of the diesel fuel include catalysts with a relatively low surface area, such as catalysts with a ratio of zeolite surface area to external surface area of at least about 80:100. The dewaxing catalysts are described as having a hydrogenation metals content of at least 0.1 wt %.

SUMMARY

In various aspects, a method for producing distillate fuel products is provided. The method can include exposing a feed comprising a distillate fuel boiling range fraction and an olefin co-feed to a dewaxing catalyst. The dewaxing catalyst can comprising a crystalline structure having a zeolitic framework and a metal hydrogenation component. The feed comprising the distillate fuel boiling range portion and the olefin co-feed can be exposed to the dewaxing catalyst under effective dewaxing conditions to produce a dewaxed effluent. The dewaxed effluent can have a cloud point that is reduced relative to a cloud point of the feed by at least 2° C. The feed can optionally comprise an organic sulfur content of about 100 wppm or less. The olefin co-feed can comprise 0.5 wt % to 20 wt % of C₂-C₉olefins based on a weight of the feed. Relative to a temperature of the feed prior to the exposing, the temperature during the exposing can be at least 3° C. greater, or at least 10° C. greater, or at least 15° C. greater.

In some aspects, the olefin co-feed can comprise 0.5 wt % to 5 wt % of C₂-C₄olefins or 2 wt % to 20 wt % of C₅-C₉olefins. In some aspects, the feed can comprise about 15 wt % or less aromatics, or about 10 wt % or less, or about 5 wt % or less.

In some aspects, the effective dewaxing conditions can comprise a pressure of from about 200 psig (1.4 MPag) to about 1500 psig (10.4 MPag) and/or a temperature of from about 288° C. to about 440° C. and/or a hydrogen treat gas rate of about 500 scf/bbl (84 Nm³/m³) to about 4000 scf/bbl (674 Nm³/m³) or less, and/or a LHSV of from about 0.3 hr⁻¹to about 10 hr⁻¹relative to the dewaxing catalyst, or about 1.0 hr⁻¹to about 10 hr⁻¹relative to the dewaxing catalyst, or about 1.0 hr⁻¹to about 6.0 hr⁻¹. Optionally, the effective dewaxing conditions can comprise a pressure of about 400 psig (˜2.8 MPag) to about 1500 psig (˜10.4 MPag) and a temperature of at least about 343° C., or a pressure of about 400 psig (˜2.8 MPag) to about 1000 psig (˜6.9 MPag) and a temperature of at least about 343° C., or a pressure of about 800 psig (˜5.5 MPag) to about 1500 psig (˜10.4 MPag) and a temperature of at least about 370° C.

In some aspects, the method can further comprise exposing a feedstock comprising an organic sulfur content of 200 wppm to 12000 wppm to a hydrotreating catalyst to form a hydrotreated effluent comprising the distillate fuel boiling range fraction, wherein exposing the feed to a dewaxing catalyst comprises exposing at least a portion of the hydrotreated effluent to the dewaxing catalyst. In such aspects, the effective hydrotreating conditions can comprise a pressure of from about 200 psig (1.4 MPa) to about 3000 psig (20.7 MPa), a temperature of from about 500° F. (260° C.) to about 800° F. (427° C.), a hydrogen treat gas rate of about 500 SCF/B (84 Nm³/m³) to about 10000 SCF/B (1685 Nm³/m³) and a space velocity of from about 0.3 hr⁻¹to about 5.0 hr⁻¹. Optionally, in such aspects at least a portion of the hydrotreating catalyst and at least a portion of the dewaxing catalyst can comprise a catalyst bed. Optionally, exposing the feedstock comprising an organic sulfur content to a hydrotreating catalyst comprises exposing the feedstock comprising an organic sulfur content and an olefin co-feed to the hydrotreating catalyst.

In some aspects, a) the metal hydrogenation component can comprise Pt, Pd, or a combination thereof b) the zeolitic framework can comprise an MRE framework structure, an MTT framework structure, ZSM-48, ZSM-23, or a combination thereof; or c) a combination of a) and b), the dewaxing catalyst optionally further comprising a binder, the binder optionally comprising alumina, silica, silica-alumina, titania, zirconia, or a combination thereof.

In some aspects, the feed can have a T5 boiling point of at least about 300° F. (149° C.) and a T95 boiling point of about 800° F. (371° C.) or less, and/or (in aspects involving hydrotreatment of a feedstock) the feedstock can have a T5 boiling point of at least about 300° F. (149° C.) and a T95 boiling point of about 800° F. (371° C.) or less.

In some aspects, the olefin co-feed can comprise a portion of an FCC effluent stream comprising C₃olefins, C₄olefins, or a combination thereof, the portion of the FCC effluent stream optionally comprising at least 50 wt % of C₃olefins and/or C₄olefins, or at least 75 wt %.

In various aspects, a dewaxed effluent is provided. The dewaxed effluent can include about 86 wt % to about 96 wt % of a distillate boiling range fraction relative to a total hydrocarbon content of the dewaxed effluent. The dewaxed effluent can further include about 1 wt % to about 3 wt % of a naphtha boiling range fraction. The dewaxed effluent can further include about 3 wt % to about 11 wt % of propane, butane, or a combination thereof (or about 5 wt % to about 10 wt %, or about 3 wt % to about 8 wt %, or about 5 wt % to about 8 wt %). The distillate boiling range fraction of the dewaxed effluent can have a cloud point of −20° C. or less.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 schematically shows an example of a reactor configuration for hydroprocessing a distillate fuel boiling range fraction.

FIG. 2 schematically shows another example of a reactor configuration for hydroprocessing a distillate fuel boiling range fraction.

DETAILED DESCRIPTION OF THE EMBODIMENTS Overview

In various aspects, methods are provided for dewaxing a distillate fuel boiling range feed to improve one or more cold flow properties of the distillate fuel feed, such as cloud point. The dewaxing can be performed in the presence of an olefin co-feed that allows for an increase in the average temperature for exposure of the feed to the dewaxing catalyst. If the dewaxing catalyst is included in a reactor that also includes other hydroprocessing catalyst(s), the olefin co-feed can be introduced into the reactor at a location after the hydroprocessing catalyst bed(s) and prior to the dewaxing catalyst bed(s). Due to the relative ease of performing olefin saturation in the presence of a catalyst with a hydrogenation metal, a substantial portion of the olefins in an olefin co-feed (such as substantially all) can be converted to alkanes. Olefin saturation is exothermic, so the conversion of olefins to alkanes can provide a temperature increase for a feed as it is being exposed to catalyst in a catalyst bed. The ability to selectively increase the temperature for exposure of the feed to the dewaxing catalyst can potentially increase the total cycle length for a reactor configuration by about 3% to about 25%, or about 5% to about 20%, relative to the total cycle length for the reactor configuration without the use of olefin co-feed. Alternatively, the use of an olefin co-feed can allow a more challenging feed to be processed at a given cycle length for a reactor configuration.

In some aspects, increasing the dewaxing temperature by using an olefin co-feed can allow dewaxing to be performed at a temperature greater than the temperature that can be achieved by a heating unit/heating method associated with a reactor. This can extend the cycle length for a reactor by allowing the reactor to process feed to a desired target specification (such as a desired cloud point). Instead of being constrained by the maximum temperature that can be delivered by a heating unit associated with a reactor, an olefin co-feed can allow for a further temperature increase. This can be beneficial, for example, in situations where the hydrotreating catalyst in a reactor can still satisfy a target sulfur specification at the temperatures that can be achieved in a reactor, but a dewaxing catalyst does not have sufficient activity to meet a target cloud point specification.

In other aspects, increasing the dewaxing temperature by using an olefin co-feed can allow the temperature across a dewaxing catalyst bed to be selected separately from a prior hydrotreating catalyst bed in the same reactor. This can be beneficial, for example, at the beginning of a processing run. In the early stages of a distillate hydrotreating and dewaxing process, the temperature required to achieve a desired sulfur target may be lower than the temperature required to achieve a corresponding desired cloud point (or other cold flow property). Conventionally, the temperature of such a reactor would be selected to correspond to the higher temperature required by the dewaxing catalyst. This would result in processing the feed over the hydrotreating catalyst at a higher temperature than necessary for sulfur removal, which can accelerate the rate of deactivation of a catalyst. By introducing an olefin co-feed into a reactor between the hydrotreating and dewaxing catalyst beds, the dewaxing temperature can be increased (to achieve a desired cold flow property) while allowing the hydrotreating temperature to be set at a lower value (for achieving the desired sulfur specification).

The range of temperatures suitable for distillate dewaxing can be somewhat limited. Depending on the nature of the feed and the desired product, the start of run temperature for dewaxing of a feed for making distillate fuels can be about 290° C. to 400° C., or about 330° C. to about 380° C., or about 370° C. to about 400° C. In some aspects, this type of elevated initial temperature can be beneficial when making a winter diesel or arctic diesel, such as a diesel fuel product having a cloud point of −20° C. or less, or −40° C. or less, or −60° C. or less. If a single reactor is used for both hydrotreating and dewaxing of the feed for making distillate fuel, a separate heater for heating the feed between hydrotreatment and dewaxing may not be available in the reactor configuration. This can lead to selecting a higher temperature for all of the catalyst beds in the reactor in order to provide the desired temperature for the dewaxing process. While prior beds of hydrotreating catalyst can be effective for sulfur removal at higher temperature, operating a hydrotreating catalyst at higher temperature can typically lead to faster catalyst deactivation, as well as unnecessary conversion of feed to lower boiling (and typically lower value) products.

In other aspects, an elevated starting temperature for dewaxing can be due to limited space for inclusion of a dewaxing catalyst when more modest cloud point uplift is desired. For example, if an existing reactor configuration does not include a separate reactor and/or separate bed for dewaxing catalyst, the inclusion of dewaxing catalyst in a reactor configuration may correspond including the dewaxing catalyst as a portion of an existing catalyst bed and/or by replacing a bed of hydrotreating catalyst. In this type of situation, the amount of dewaxing catalyst in the reactor may be relatively small relative to the flow rate of feed, leading to feed space velocities (LHSV) relative to the dewaxing catalyst alone of 1.0 hr⁻¹to 10 hr⁻¹, or 2.0 hr⁻¹to 6 hr⁻¹, or 4.0 hr⁻¹to 10 hr⁻¹. At this type of space velocity, even a modest decrease in cloud point can require exposing the feed to the dewaxing catalyst at an elevated start of run temperature.

In various aspects, the above difficulties related to elevated start of run temperature requirements for a dewaxing catalyst can be reduced or minimized by adding an olefin co-feed prior to exposing the distillate fuel feed to the dewaxing catalyst. For example, in a reactor configuration including multiple catalyst beds, an olefin co-feed can be introduced in the space between catalyst beds. Such an olefin co-feed can be introduced in a manner similar to a quench stream between catalyst beds. Exposing the olefin co-feed to the dewaxing catalyst can result in olefin saturation, which can generate additional heat within the catalyst bed. Depending on the nature of the olefins in the olefin co-feed, temperature increases of up to about 45° F. (˜25° C.) can be achieved. For example, the temperature during dewaxing can be increased by 3° C. to 25° C., or 3° C. to 15° C., or 10° C. to 25° C., or 5° C. to 15° C. This temperature increase can be beneficial, for example, in situations where the difference between the start-of-run temperature and end-of-run temperature for a reactor is limited. For example, if the start-of-run temperature (such as a temperature to meet a maximum sulfur amount in the hydrotreated effluent) is about 330° C. and the end of run temperature (based on limitations of the reactor configuration) is about 380° C., the total operating window for the reactor is only about 50° C. Any reduction of this operating window based on the temperature requirements for meeting a second specification (such as cloud point) can result in a substantial reduction in the cycle length for the reactor. The addition of an olefin co-feed prior to a catalyst bed containing dewaxing catalyst can avoid the need to shrink the operating window of a reactor in this type of situation.

The addition of an olefin co-feed can, in some aspects, also provide a benefit for extending the operating window of a reactor by increasing the end-of-run temperature that can be achieved for dewaxing. From a practical standpoint, many types of dewaxing catalysts can operate effectively at temperatures up to about 440° C., at which point thermal cracking reactions can start to cause substantial conversion of a feed. Although dewaxing catalysts may be suitable for dewaxing at up to 440° C., many reactor configurations have design limits that lead to lower end-of-run temperatures. Depending on the reactor configuration, the heating units associated with a reactor configuration may have a maximum temperature within a reactor of about 330° C. to about 400° C., or about 350° C. to about 380° C. For reactor configurations with limited heating capability, the ability to selectively increase the temperature for exposure of feed to dewaxing catalyst can potentially allow for several weeks (or possibly months) of additional cycle length. For example, in a reactor configuration with a limited amount of dewaxing catalyst (i.e., high space velocity of feed relative to only dewaxing catalyst), the operating temperature for the reactor configuration may be dictated by the temperature required for achieving the cold flow properties (such as cloud point) for the resulting distillate fuel product. By using an olefin co-feed, the temperature across the catalyst bed containing dewaxing catalyst can be increased beyond the expected maximum for the reactor configuration. This can allow, for example, the cycle length to be extended until additional deactivation has occurred for the hydrotreating catalyst, or until a scheduled shut down event, or until another convenient end-of-run time. Optionally, olefins can also be added to a feed prior to exposure of the feed to a hydrotreating catalyst, to provide additional heat for a hydrotreating step. This can potentially be beneficial, for example, when virgin distillate feed or another type of low olefin, low aromatic content feed is being processed.

In this discussion and the claims below, references to a dewaxing temperature are references to an average temperature across the dewaxing catalyst in a fixed bed (such as a catalyst bed in a trickle bed reactor). The average temperature is defined as the average of the temperature at the top of the catalyst bed and the bottom of the catalyst bed. This average temperature definition is applied to catalyst beds that are either substantially filled with dewaxing catalyst or catalyst beds that include a first portion of dewaxing catalyst and a second portion of another type of catalyst (the catalysts being loaded in either order). In the claims below, cloud points can be determined according to ASTM D7397.

Feedstocks

In some aspects, a feedstock for producing distillate fuel boiling range products can have an initial boiling point of at least about 200° F. (93° C.), or at least about 250° F. (121° C.), or at least about 300° F. (149° C.), or at least about 350° F. (177° C.), or at least about 400° F. (204° C.), or at least about 450° F. (232° C.). The initial boiling point can vary widely, depending on how much kerosene and/or other lighter components are included in a feedstock. In another embodiment, the feedstock can have a final boiling point of about 800° F. (427° C.) or less, or about 700° F. (371° C.) or less, or about 650° F. (343° C.) or less. Another way of characterizing a feedstock is based on the boiling point required to boil a specified percentage of the feed. For example, the temperature required to boil at least 5 wt % of a feed is referred to as a “T5” boiling point. When characterizing a feed based on a T5 boiling point, the feedstock can have a T5 boiling point at least about 200° F. (93° C.), or at least about 250° F. (121° C.), or at least about 300° F. (149° C.), or at least about 350° F. (177° C.), or at least about 400° F. (204° C.), or at least about 450° F. (232° C.). In some aspects, the feedstock can correspond to a feedstock that has a T5 boiling point of at least about 350° F. (177° C.), such as at least about 370° F. (188° C.), or at least about 400° F. (204° C.), or at least about 450° F. (232° C.). In another aspect, the feed can have a T95 boiling point of about 800° F. (427° C.) or less, or about 750° F. (399° C.) or less, or about 700° F. (371° C.) or less, or about 650° F. (343° C.) or less. The naphtha boiling range can be defined as from C₅to about 177° C. The distillate fuel boiling range (kerosene plus diesel) can be defined as from about 177° C. to about 427° C. The diesel boiling range can be defined as about 232° C. to about 427° C. In the claims below, the boiling point for a feed at a given weight percentage can be determined by ASTM D2887, or D86 if D2887 is not appropriate.

In some aspects, the feedstock generally comprises a mineral oil. By “mineral oil” is meant a fossil/mineral fuel source, such as crude oil, and not the commercial organic product, such as sold under the CAS number 8020-83-5, e.g., by Aldrich. Examples of mineral oils can include, but are not limited to, straight run (atmospheric) gas oils, demetallized oils, coker distillates, cat cracker distillates, heavy naphthas, diesel boiling range distillate fraction, jet fuel boiling range distillate fraction, and/or kerosene boiling range distillate fractions. The mineral oil portion of the feedstock can comprise any one of these example streams or any combination thereof. Preferably, the feedstock does not contain any appreciable asphaltenes.

Mineral feedstreams suitable for use in various embodiments can have a nitrogen content from about 10 wppm to about 6000 wppm nitrogen, such as at least about 50 wppm or at least about 100 wppm and/or about 2000 wppm or less or about 1000 wppm or less. In an embodiment, feedstreams suitable for use herein can have a sulfur content from about 10 wppm to about 40,000 wppm sulfur, or about 200 wppm to about 12,000 wppm, or about 100 wppm to about 10,000 wppm.

In some aspects, the distillate fuel boiling range fraction of a feed can have a lower sulfur content than a general feed. In such aspects, the distillate fuel boiling range fraction of a feed can have a sulfur content of 100 wppm to 5000 wppm and a nitrogen content of 20 wppm to 1000 wppm. Depending on the aspect, a feed can be hydrotreated prior to dewaxing to reduce the amount of sulfur and/or nitrogen content that a dewaxing catalyst is exposed to. In such aspects, performing an optional separation between the hydrotreating and dewaxing stages may be desirable. Either with or without such hydrotreating, in some aspects the sulfur content of a distillate fuel boiling range feedstock for exposure to a dewaxing catalyst can be about 200 wppm or less, or about 100 wppm or less, or about 50 wppm or less, or about 20 wppm or less, such as down to about 1 wppm or possibly lower. In such aspects, the nitrogen content of the distillate fuel boiling range feedstock for exposure to a dewaxing catalyst can be about 100 wppm or less, or about 20 wppm or less, or about 10 wppm or less, such as down to about 1 wppm or possibly lower.

In some aspects, a distillate fuel boiling range feed can typically have an aromatics content of at least about 1 wt %, or at least about 3 wt %, such as at least about 5 wt %, or at least about 10 wt % and/or about 50 wt % or less, or about 35 wt % or less, or about 25 wt % or less, or about 15 wt % or less, or about 10 wt % or less, or about 5 wt % or less. In particular, the aromatics content can be about 3 wt % to about 15 wt %, or about 3 wt % to about 10 wt %, or about 1 wt % to about 5 wt %, or about 1 wt % to about 50 wt %, or about 5 wt % to about 35 wt %, or about 10 wt % to about 25 wt %, or about 10 wt % to about 35 wt %. In the claims below, aromatics content can be determined according to ASTM D5186. In some aspects, the olefin content of a distillate boiling range feed prior to hydrotreatment can vary. After hydrotreatment, a distillate boiling range feed can typically have an aliphatic olefin content of about 3 wt % or less, or about 1 wt % or less, such as down to about 0.1 wt % or possibly lower. Aliphatic olefin content can be determined based on bromine number, as specified in ASTM D1492.

In various aspects of the invention, the feed can also include portions of the feed that are from biocomponent sources. The feed can include varying amounts of feedstreams based on biocomponent sources, such as vegetable oils, animal fats, fish oils, algae oils, etc. For a biocomponent feed that has been previously hydroprocessed or that is otherwise compatible with conventional refinery equipment, the feed could potentially be entirely derived from a biocomponent source. More typically, the feed can include at least 0.1 wt % of feed based on a biocomponent source, or at least 0.5 wt %, or at least 1 wt %, or at least 3 wt %, or at least 10 wt %, or at least 15 wt %. In such embodiments, the feed can include 90 wt % or less of a feed based on a biocomponent source, or 60 wt % or less, or 40 wt % or less, or 20 wt % or less. In other embodiments, the amount of co-processing can be small, with a feed that includes at least 0.5 wt % of feedstock based on a biocomponent source, or at least 1 wt %, or at least 2.5 wt %, or at least 5 wt %. In such an embodiment, the feed can include 20 wt % or less of biocomponent based feedstock, or 15 wt % or less, or 10 wt % or less, or 5 wt % or less.

In this discussion, a biocomponent feed or feedstock refers to a hydrocarbon feedstock derived from a biological raw material component, such as vegetable fats/oils or animal fats/oils, fish oils, pyrolysis oils, and algae lipids/oils, as well as components of such materials, and in some embodiments can specifically include one or more types of lipid compounds. A biocomponent portion of a feed can be a portion that has been previously hydroprocessed, a portion that has not been previously hydroprocessed, or a combination thereof.

In various aspects, an olefin co-feed can be introduced prior to exposing a distillate fuel boiling range feed to a dewaxing catalyst. The olefin co-feed can correspond to any convenient type of olefin. The amount of olefin co-feed relative to the amount of distillate fuel boiling range feed can vary depending on the type of olefin. For small olefins such as C₂-C₄olefins (i.e., ethylene, propylene, butenes), the amount of olefins in the olefin co-feed can correspond to about 0.5 wt % to about 5 wt % of the distillate fuel boiling range feed. For larger olefins such as C₅-C₉olefins, the amount of olefins in the olefin co-feed can correspond to about 2 wt % to about 20 wt %. Still larger olefins (C₉₊) could potentially also be used in an amount of about 2 wt % to about 20 wt %, but may be impractical due to the lower density of olefin bonds in the co-feed. It is noted that as the size of an olefin increases, the relative amount of olefin linkages per wt % of olefin is decreased. Therefore, a lower amount of small olefins can achieve a similar temperature increase to a larger amount of large olefins. As an example, adding about 2 wt % of ethylene (based on weight of the distillate fuel boiling range feed) as a co-feed prior to exposure of the feed to a dewaxing catalyst can provide a dewaxing temperature increase of about 10° F. (˜6° C.). About 10 wt % of nonene as a co-feed would be required to achieve a similar temperature increase.

The olefin selected as a co-feed can have different impacts on a reactor configuration depending on the nature of the olefin. For C₂olefins, exposure of the ethylene to the dewaxing catalyst can produce ethane. Ethane can have a tendency to separate out along with hydrogen for recycle in a hydrogen recycle loop. In reactor configurations where a hydrogen recycle loop is used, introduction of ethylene as an olefin co-feed may require larger purge rates to avoid ethylene accumulation in the hydrogen recycle loop. This can lead to larger requirements for make-up hydrogen in a reactor configuration. For C₉(and larger) olefins, the corresponding saturated alkanes can correspond to diesel boiling range compounds. However, a C₉alkane can have a lower energy density than a typical diesel fuel, so introduction of substantial amounts of C₉alkane may not be desirable for distillate fuel boiling range feeds that are toward the low end of acceptable energy density. For C₅-C₈olefins, the corresponding saturated alkanes can correspond to naphtha boiling range compounds. Such olefins can be readily separated from a diesel fuel product by fractionation.

Optionally, an olefin co-feed can include a diluent. Any convenient diluent can be present, such as alkanes, inert gases, naphtha and/or distillate fuel boiling range components, or any other type of diluent that is compatible with the environment for hydrotreatment and dewaxing of a distillate fuel boiling range feed. For an olefin co-feed that includes a diluent, the amount of co-feed introduced into a reactor can be specified based on the weight ratio of olefins to distillate fuel boiling range feed, as described above.

Catalyst for Distillate Fuel Dewaxing

In some aspects, dewaxing catalysts can be selected from zeolitic materials. In this discussion and the claims below, a zeolite is defined to refer to a crystalline material having a porous framework structure built from tetrahedra atoms connected by bridging oxygen atoms. Examples of known zeolite frameworks are given in the “Atlas of Zeolite Frameworks” published on behalf of the Structure Commission of the International Zeolite Association”, 6^threvised edition, Ch. Baerlocher, L. B. McCusker, D. H. Olson, eds., Elsevier, New York (2007) and the corresponding web site, http://www.iza-structure.org/databases/. Under this definition, a zeolite can refer to aluminosilicates having a zeolitic framework type as well as crystalline structures containing oxides of heteroatoms different from silicon and aluminum. Such heteroatoms can include any heteroatom generally known to be suitable for inclusion in a zeolitic framework, such as gallium, boron, germanium, phosphorus, zinc, and/or other transition metals that can substitute for silicon and/or aluminum in a zeolitic framework.

In some aspects, the zeolitic material can have a 1-D or 3-D network of pore channels, such as a 1-D or 3-D molecular sieve. Examples of molecular sieves can include ZSM-48, ZSM-23, ZSM-35, ZSM-11, ZSM-5, and combinations thereof. In an embodiment, the molecular sieve can be ZSM-48, ZSM-23, or a combination thereof. Still other suitable molecular sieves can include SSZ-32, EU-2, EU-11, and/or ZBM-30.

In other aspects, a dewaxing catalyst can more generally correspond to any of a variety of dewaxing catalysts that conventionally have been used for distillate dewaxing. This can include any of various dewaxing catalysts based on a zeolitic framework structure, such as a molecular sieve having at least a 10-member ring or a 12-member ring pore channel.

Optionally, the dewaxing catalyst can include a binder, such as alumina, titania, silica, silica-alumina, zirconia, or a combination thereof. In an embodiment, the binder can be alumina. In another embodiment, the binder can be alumina, titania, or a combination thereof. In still another embodiment, the binder can be titania, silica, zirconia, or a combination thereof. Optionally, the binder can correspond to a binder with a relatively high surface area. One way to characterize the surface of the binder is in relation to the surface area of the molecular sieve in the dewaxing catalyst. For example, the ratio of molecular sieve surface area to binder surface can be about 80 to 100 or less, such as about 70 to 100 or less or about 60 to 100 or less.

One feature of zeolitic materials that can impact activity is the molar ratio of silica to alumina in the zeolitic material. In an embodiment where a dewaxing catalyst includes ZSM-48, the zeolitic framework structure can have a silica to alumina ratio of about 110 to 1 or less, such as about 100 to 1 or less, and preferably about 90 to 1 or less, such as about 80 to 1 or less. When the molecular sieve is ZSM-48, the molecular sieve preferably has a silica to alumina ratio of at least about 60 to 1. For example, the ratio of silica to alumina for ZSM-48 can be from about 60 to 1 to about 110 to 1, or about 60 to 1 to about 90 to 1, or about 60 to 1 to about 85 to 1.

The dewaxing catalyst can also include a metal hydrogenation component, such as a Group VIII metal (Groups 8-10 of IUPAC periodic table). Suitable Group VIII metals can include Pt, Pd, Co, or Ni. Preferably the Group VIII metal is a noble metal, such as Pt, Pd, or a combination thereof. The dewaxing catalyst can include at least about 0.1 wt % of a Group VIII metal, such as at least about 0.5 wt %, or at least about 1.0 wt %. Additionally or alternately, the dewaxing catalyst can include about 10.0 wt % or less of a Group VIII metal, such as about 5.0 wt % or less, or about 3.5 wt % or less. For example, the dewaxing catalyst can include from 0.1 wt % to 10.0 wt % of a Group VIII metal, or about 0.1 wt % to about 5.0 wt %, or about 0.1 wt % to about 3.5 wt %.

Catalytic dewaxing can be performed by exposing a feedstock to a dewaxing catalyst under effective (catalytic) dewaxing conditions. Effective dewaxing conditions can include a temperature of at least about 550° F. (288° C.), or at least about 600° F. (316° C.), or at least about 650° F. (343° C.). Alternatively, the temperature can be about 825° F. (440° C.) or less, or about 750° F. (399° C.) or less, or about 700° F. (371° C.) or less, or about 650° F. (343° C.) or less. In particular, the dewaxing temperature can be about 288° C. to about 440° C., or about 300° C. to about 399° C., or about 300° C. to about 380° C. In aspects where an olefin co-feed is introduced at or near the start-of-run, the start-of-run temperature for dewaxing can be about 288° C. to about 385° C., or about 300° C. to about 370° C., or about 320° C. to about 350° C. In aspects where an olefin co-feed is introduced to provide increased dewaxing temperatures at or near the end-of-run, the end-of-run temperature for dewaxing can be about 330° C. to about 360° C., or about 350° C. to about 380° C., or about 370° C. to about 400° C., or about 400° C. to about 440° C.

Effective dewaxing conditions can also include a pressure of at least about 200 psig (1.4 MPag), or at least about 500 psig (3.4 MPag), or at least about 750 psig (5.2 MPag), or at least about 1000 psig (6.9 MPag). Alternatively, the pressure can be about 1500 psig (10.3 MPag) or less, or about 1200 psig (8.2 MPag) or less, or about 1000 psig (6.9 MPag) or less, or about 800 psig (5.5 MPag) or less. The treat gas rate can be at least about 500 scf/bbl (84 m³/m³), at least about 750 scf/bbl (126 m³/m³), or at least about 1000 scf/bbl (169 m³/m³). Alternatively, the treat gas rate can be about 4000 scf/bbl (674 m³/m³) or less, or about 2000 scf/bbl (337 m³/m³) or less, or about 1500 scf/bbl (253 m³/m³) or less, or about 1250 scf/bbl (211 m³/m³) or less.

With regard to space velocity, the Liquid Hourly Space Velocity (LHSV) can vary depending on the reactor configuration. In some reactor configurations the amount of dewaxing catalyst may be small relative to the amount of other catalysts, which can result in high LHSV values with respect to just dewaxing catalyst. In other words, even though the space velocity relative to the total catalyst volume might be between 0.1 hr⁻¹and 5 hr⁻¹, due to a relatively small amount of dewaxing catalyst LHSV relative to dewaxing catalyst may be substantially higher. In various aspects, the LHSV relative to dewaxing catalyst can be at least about 0.5 hr⁻¹, or at least about 1.0 hr⁻¹, or at least about 1.5 hr⁻¹, or at least about 2.0 hr⁻¹. Alternatively, the LHSV can be about 10 hr⁻¹or less, or about 6.0 hr⁻¹or less, or about 3.0 hr⁻¹or less, or about 2.0 hr⁻¹or less. In particular, the LHSV can be about 0.5 hr⁻¹to 10 hr⁻¹, or about 0.5 hr⁻¹to about 6.0 hr⁻¹, or about 1.0 hr⁻¹to about 10 hr⁻¹, or about 1.0 hr⁻¹to about 6.0 hr⁻¹, or about 0.5 hr⁻¹to about 3.0 hr⁻¹, or about 0.5 hr⁻¹to about 2.0 hr⁻%, or about 1.0 hr⁻¹to about 3.0 hr⁻¹.

Based on dewaxing under effective catalytic dewaxing conditions, the cloud point of a dewaxed distillate fuel fraction can be reduced relative to the feedstock by at least about 6° F. (3° C.), or at least about 10° F. (5° C.), such as at least about 20° F. (11° C.), or at least about 30° F. (17° C.), such as up to about 45° F. (25° C.) or more. The amount of cloud point reduction can depend on a variety of factors, including the sulfur content of the feedstock, the nitrogen content of the feedstock, and the selected effective dewaxing conditions.

Hydrotreatment and/or Hydrofinishing

Optionally, the feedstock can be treated in one or more hydrotreatment stages prior to dewaxing. The reaction conditions in a hydrotreatment stage can be conditions suitable for reducing the sulfur content of the feedstream. The reaction conditions can include an LHSV of 0.3 to 5.0 hr⁻¹, a total pressure from about 200 psig (1.4 MPag) to about 3000 psig (20.7 MPag), a treat gas containing at least about 80% hydrogen (remainder inert gas), and a temperature of from about 500° F. (260° C.) to about 825° F. (440° C.). Preferably, the reaction conditions include an LHSV of from about 0.5 to about 1.5 hr⁻¹, a total pressure from about 700 psig (4.8 MPag) to about 2000 psig (13.8 MPag), and a temperature of from about 600° F. (316° C.) to about 700° F. (399° C.). The treat gas rate can be from about 500 SCF/B (84 Nm³/m³) to about 10000 SCF/B (1685 Nm³/m³) of hydrogen, depending on various factors including the nature of the feed being hydrotreated. Note that the above treat gas rates refer to the rate of hydrogen flow. If hydrogen is delivered as part of a gas stream having less than 100% hydrogen, the treat gas rate for the overall gas stream can be proportionally higher.

In some aspects of the invention, the hydrotreatment stage(s) can reduce the sulfur content of the feed to a suitable level. For example, the sulfur content can be reduced sufficiently so that the feed into the dewaxing stage can have about 500 wppm sulfur or less, or about 250 wppm or less, or about 100 wppm or less, or about 50 wppm or less. Additionally or alternately, the sulfur content of the feed to the dewaxing stage can be at least about 1 wppm sulfur, or at least about 5 wppm, or at least about 10 wppm. Additionally or alternately, the sulfur content of the hydrotreated effluent can correspond to any of the other sulfur values noted above.

The catalyst in a hydrotreatment stage can be a conventional hydrotreating catalyst, such as a catalyst composed of a Group VIB metal (Group 6 of IUPAC periodic table) and/or a Group VIII metal (Groups 8-10 of IUPAC periodic table) on a support. Suitable metals include cobalt, nickel, molybdenum, tungsten, or combinations thereof. Preferred combinations of metals include nickel and molybdenum or nickel, cobalt, and molybdenum. Suitable supports include silica, silica-alumina, alumina, and titania.

After hydrotreatment, the hydrotreated effluent can optionally but preferably be separated, such as by separating the gas phase effluent from a liquid phase effluent, in order to remove gas phase contaminants generated during hydrotreatment. Alternatively, in some aspects the entire hydrotreated effluent can be cascaded into the catalytic dewaxing stage(s).

Optionally, a hydrofinishing stage can also be included after the catalytic dewaxing stage(s), such as in the final catalytic dewaxing reactor or in a separate reactor. Hydrofinishing catalysts can include catalysts containing Group VI metals, Group VIII metals, and mixtures thereof. In an embodiment, preferred metals include at least one metal sulfide having a strong hydrogenation function. In another embodiment, the hydrofinishing catalyst can include a Group VIII noble metal, such as Pt, Pd, or a combination thereof. The mixture of metals may also be present as bulk metal catalysts wherein the amount of metal is about 30 wt. % or greater based on catalyst. Suitable metal oxide supports include low acidic oxides such as silica, alumina, silica-aluminas or titania, preferably alumina. The preferred hydrofinishing catalysts for aromatic saturation will comprise at least one metal having relatively strong hydrogenation function on a porous support. Typical support materials include amorphous or crystalline oxide materials such as alumina, silica, and silica-alumina. The support materials may also be modified, such as by halogenation, or in particular fluorination. The metal content of the catalyst is often as high as about 20 weight percent for non-noble metals. In an embodiment, a preferred hydrofinishing catalyst can include a crystalline material belonging to the M41S class or family of catalysts. The M41S family of catalysts are mesoporous materials having high silica content. Examples include MCM-41, MCM-48 and MCM-50. A preferred member of this class is MCM-41.

Hydrofinishing conditions can include temperatures from about 125° C. to about 425° C., or about 180° C. to about 280° C., a total pressure from about 200 psig (1.4 MPa) to about 800 psig (5.5 MPa), or about 400 psig (2.8 MPa) to about 700 psig (4.8 MPa), and a liquid hourly space velocity from about 0.1 hr⁻¹to about 5 hr⁻¹LHSV, preferably about 0.5 hr⁻¹to about 1.5 hr⁻¹. The treat gas rate can be selected to be similar to a catalytic dewaxing stage, similar to a hydrotreatment stage, or any other convenient selection.

Dewaxed Effluent

The dewaxed effluent from processing a distillate fuel boiling range feed with an olefin co-feed can differ from a typical dewaxed distillate fuel effluent based on the inclusion of additional amounts of small alkane produced by the olefin saturation. For example, in aspects where 1 wt % to 5 wt % of C₃and/or C₄olefins are used as the olefin co-feed, the total hydrocarbon product of the dewaxed effluent can include about 86 wt % to about 98 wt % of a distillate boiling range fraction, about 1 wt % to about 3 wt % of a naphtha boiling range fraction, and about 3 wt % to about 11 wt % of propane and/or butane, or about 5 wt % to about 10 wt %, or about 3 wt % to about 8 wt %, or about 5 wt % to about 8 wt %. In aspects where 1 wt % to 5 wt % of a C₂-C₄olefin is used as the olefin co-feed, the total hydrocarbon product of the dewaxed effluent can include about 86 wt % to about 98 wt % of a distillate boiling range fraction, about 1 wt % to about 3 wt % of a naphtha boiling range fraction, and about 3 wt % to about 11 wt % of C₂-C₄alkanes, or about 5 wt % to about 10 wt %, or about 3 wt % to about 8 wt %, or about 5 wt % to about 8 wt %.

Sample Configurations

FIG. 1 schematically shows an example of a reactor 100 for processing a distillate fuel boiling range fraction. In the example shown in FIG. 1, reactor 100 includes a first catalyst bed 110 that contains hydrotreating catalyst and a second catalyst bed 120 that contains a dewaxing catalyst. Optionally, a portion of the catalyst in catalyst bed 120 can correspond to hydrotreating catalyst. Optionally, a portion of the catalyst in catalyst bed 120 can correspond to an aromatic saturation catalyst. Optionally, a reactor 100 can include one or more first catalyst beds 110 and/or one or more second catalyst beds 120.

During operation, a feed 105 can be introduced into reactor 110. Hydrogen treat gas can be included as part of feed 105, or one or more hydrogen treat gas inputs 101 of hydrogen treat gas can be introduced into reactor 100. In the example shown in FIG. 1, the hydrogen treat gas is shown as being introduced at the top of reactor 100. In other aspects, hydrogen treat gas input(s) 101 can be introduced at any convenient location in the reactor. Between the first catalyst bed 110 and second catalyst bed 120, an olefin co-feed 115 can be introduced into the reactor. Additionally or alternately, an optional olefin co-feed 108 may be introduced at the top of bed 110 to add heat across the entire reactor and extend operational life beyond the heater capacity. The hydrotreated and dewaxed effluent can exit the reactor as an effluent 125.

FIG. 2 shows another example of a reactor configuration for hydrotreating and dewaxing a distillate fuel boiling range feed. The reactor configuration shown in FIG. 2 includes a first reactor 230 that includes a plurality of catalyst beds 232, 234, and 236 containing hydrotreating catalyst. The hydrotreated effluent 235 from first reactor 230 is cascaded into second reactor 240 that contains a plurality of catalyst beds 242, 244, and 246 containing dewaxing catalyst. The dewaxed effluent 245 from second reactor 240 can be passed into a separation stage 250 for separation of distillate fuel boiling range products from lower boiling range products, such as naphtha or light ends.

In the example reactor configuration shown in FIG. 2, hydrogen treat gas can be introduced at any convenient location. The example reactor configuration in FIG. 2 shows introduction of hydrogen treat gas input 231 at the top of first reactor 230, and introduction of hydrogen treat gas input 241 at the top of the second reactor 240. In other aspects, hydrogen could be introduced into first reactor 230 via quench gas inputs 285 or introduced into second reactor 240 via quench gas inputs 275.

In FIG. 2, an olefin co-feed 265 can be introduced into second reactor 240 via one or more of the quench gas inputs 275. Instead of introducing hydrogen, nitrogen, or another gas to reduce the temperature between reactors and/or between catalyst beds, introducing an olefin co-feed 265 via the quench gas inputs 275 can allow for additional temperature increase between reactors and/or between catalyst beds. The olefin co-feed can be added at any desired location in second reactor 240. In FIG. 2, the olefin co-feed is shown as being added prior to the first catalyst bed 242. In other aspects, in addition to or instead of adding olefin co-feed prior to the first catalyst bed 242, olefin co-feed can introduced between catalyst beds 242 and 244, and/or between catalyst beds 244 and 246.

Example 1

The following is a prophetic example. A distillate fuels boiling range feed with a sulfur content of about 1500 wppm, a nitrogen content of about 60 wppm, and a cloud point of 0° C. was introduced into a reactor that included three catalyst beds of a commercially available base metal hydrotreating catalyst. The third catalyst bed also included a commercially available dewaxing catalyst based on a 1-D 10-member ring molecular sieve. The space velocity (LHSV) of the feed relative to the dewaxing catalyst was 4 hr⁻¹, while the space velocity of the feed relative to the hydrotreating catalyst was 1.5 hr⁻¹. At a hydrogen partial pressure of 6.9 MPag, the start of run temperature required to reduce the sulfur content of the effluent to 10 wppm was 270° C. An average temperature of 270° C. across the first two catalyst beds would result in a temperature between the second bed and the final bed of 292° C. The temperature required to achieve a desired winter diesel cloud point of −30° C. was 350° C. In order to minimize the overtreatment and unnecessary catalyst deactivation in the first 2 beds, an olefin co-feed was introduced between the second and third catalyst bed. The olefin co-feed included 5 wt % of a mixture of C₃and C₄olefins from an FCC process relative to the weight of the distillate fuels boiling range feed. The stream from the FCC process included ˜70 wt % olefin content. Addition of the co-feed based on the stream from the FCC process increased the exotherm across the third catalyst bed by an additional 23° C., resulting in a total exotherm of 50° C. This allowed the start-of-run temperature to be set at an average of 300° C. across the first two catalyst beds and at 350° C. for the final catalyst bed.

Example 2

The following is a prophetic example. A distillate fuels boiling range feed with a sulfur content of about 2500 wppm, a nitrogen content of about 120 wppm, and a cloud point of 0° C. was introduced into a reactor that included three catalyst beds. The first two catalyst beds included commercially available hydrotreating catalyst. The third catalyst bed included a dewaxing catalyst based on a 10-member ring molecular sieve. After a number months of processing the feed to form a winter diesel with a cloud point of −30° C., the temperature required for the reactor to achieve the cloud point target was approaching 350° C., which was the maximum temperature that could be achieved by the heating units associated with the reactor. The sulfur level of the effluent was 7 wppm, which was below the target sulfur level. In order to extend the cycle length of the reactor by an extra month to reach the end of the winter diesel processing season, an olefin co-feed corresponding to a mixture of hexenes was introduced into the reactor prior to the dewaxing catalyst bed. The amount of olefins in the co-feed were slowly increased up to 5 wt % (relative to the weight of the distillate fuel boiling range feed) to allow for continuing increases in the dewaxing temperature to maintain the desired cloud point in the effluent. The resulting saturated hexane was removed from the effluent during fractionation to form a diesel boiling range fuel product.

ADDITIONAL EMBODIMENTS Embodiment 1

A method for producing distillate fuel products, comprising: exposing a feed comprising a distillate fuel boiling range fraction and an olefin co-feed to a dewaxing catalyst comprising a crystalline structure having a zeolitic framework and a metal hydrogenation component under effective dewaxing conditions to produce a dewaxed effluent having a cloud point that is reduced relative to a cloud point of the feed by at least 2° C. (or at least 5° C., or at least 10° C.), the feed optionally comprising an organic sulfur content of about 100 wppm or less (or about 20 wppm or less, or about 10 wppm or less) and having a feed temperature prior to the exposing, the olefin co-feed comprising 0.5 wt % to 20 wt % of C₂-C₉olefins based on a weight of the feed, the temperature during the exposing being at least 3° C. greater than the feed temperature.

Embodiment 2

The method of Embodiment 1, wherein the temperature during the exposing is at least 10° C. greater than the feed temperature, or at least 15° C. greater than the feed temperature.

Embodiment 3

The method of any of the above embodiments, wherein the effective dewaxing conditions comprise an LHSV of about 1.0 hr⁻¹to about 10 hr⁻¹relative to the dewaxing catalyst, or about 1.0 hr⁻¹to about 6.0 hr⁻¹.

Embodiment 4

The method of any of the above embodiments, wherein the olefin co-feed comprises 0.5 wt % to 5 wt % of C₂-C₄olefins, or wherein the olefin co-feed comprises 2 wt % to 20 wt % of C₅-C₉olefins.

Embodiment 5

The method of any of the above embodiments, wherein the effective dewaxing conditions comprise a pressure of from about 200 psig (1.4 MPag) to about 1500 psig (10.4 MPag), a temperature of from about 288° C. to about 440° C., a hydrogen treat gas rate of about 500 scf/bbl (84 Nm³/m³) to about 4000 scf/bbl (674 Nm³/m³) or less, and a LHSV of from about 0.3 hr⁻¹to about 10 hr⁻¹relative to the dewaxing catalyst, the effective dewaxing conditions optionally comprising a pressure of about 400 psig (˜2.8 MPag) to about 1500 psig (˜10.4 MPag) and a temperature of at least about 343° C., a pressure of about 400 psig (˜2.8 MPag) to about 1000 psig (˜6.9 MPag) and a temperature of at least about 343° C., or about 800 psig (˜5.5 MPag) to about 1500 psig (˜10.4 MPag) and a temperature of at least about 370° C.

Embodiment 6

The method of any of the above embodiments, wherein the feed comprises about 15 wt % or less aromatics, or about 10 wt % or less, or about 5 wt % or less.

Embodiment 7

The method of any of the above embodiments, further comprising exposing a feedstock comprising an organic sulfur content of 200 wppm to 12000 wppm to a hydrotreating catalyst to form a hydrotreated effluent comprising the distillate fuel boiling range fraction, wherein exposing the feed to a dewaxing catalyst comprises exposing at least a portion of the hydrotreated effluent to the dewaxing catalyst.

Embodiment 8

The method of Embodiment 7, wherein the effective hydrotreating conditions comprise a pressure of from about 200 psig (1.4 MPa) to about 3000 psig (20.7 MPa), a temperature of from about 500° F. (260° C.) to about 800° F. (427° C.), a hydrogen treat gas rate of about 500 SCF/B (84 Nm³/m³) to about 10000 SCF/B (1685 Nm³/m³) and a space velocity of from about 0.3 hr⁻¹to about 5.0 hr⁻′.

Embodiment 9

The method of Embodiment 7 or 8, wherein at least a portion of the hydrotreating catalyst and at least a portion of the dewaxing catalyst comprise a catalyst bed.

Embodiment 10

The method of any of Embodiments 7 to 9, wherein exposing the feedstock comprising an organic sulfur content to a hydrotreating catalyst comprises exposing the feedstock comprising an organic sulfur content and an olefin co-feed to the hydrotreating catalyst.

Embodiment 11

The method of any of the above embodiments, wherein a) the metal hydrogenation component comprises Pt, Pd, or a combination thereof; b) the zeolitic framework comprises an MRE framework structure, an MTT framework structure, ZSM-48, ZSM-23, or a combination thereof; or c) a combination of a) and b), the dewaxing catalyst optionally further comprising a binder, the binder optionally comprising alumina, silica, silica-alumina, titania, zirconia, or a combination thereof.

Embodiment 12

The method of any of the above embodiments, wherein the feed has a T5 boiling point of at least about 300° F. (149° C.) and a T95 boiling point of about 800° F. (371° C.) or less, or wherein the feedstock has a T5 boiling point of at least about 300° F. (149° C.) and a T95 boiling point of about 800° F. (371° C.) or less, or a combination thereof.

Embodiment 13

The method of any of the above embodiments, wherein the olefin co-feed comprises a portion of an FCC effluent stream comprising C₃olefins, C₄olefins, or a combination thereof, the portion of the FCC effluent stream optionally comprising at least 50 wt % of C₃olefins and/or C₄olefins, or at least 75 wt %.

Embodiment 14

A dewaxed effluent comprising about 86 wt % to about 96 wt % of a distillate boiling range fraction relative to a total hydrocarbon content of the dewaxed effluent, about 1 wt % to about 3 wt % of a naphtha boiling range fraction, and about 3 wt % to about 11 wt % of propane, butane, or a combination thereof (or about 5 wt % to about 10 wt %, or about 3 wt % to about 8 wt %, or about 5 wt % to about 8 wt %), the distillate boiling range fraction having a cloud point of −20° C. or less.

Embodiment 15

A dewaxed effluent made according to any of Embodiments 1 to 13.

Claims

1. A method for producing distillate fuel products, comprising:

exposing a feed comprising a distillate fuel boiling range fraction and an olefin co-feed to a dewaxing catalyst comprising a crystalline structure having a zeolitic framework and a metal hydrogenation component under effective dewaxing conditions to produce a dewaxed effluent having a cloud point that is reduced relative to a cloud point of the feed by at least 3° C., the feed comprising an organic sulfur content of about 100 wppm or less and having a feed temperature prior to the exposing, the olefin co-feed comprising 0.5 wt % to 20 wt % of C2-C9 olefins based on a weight of the feed, the temperature during the exposing being at least 3° C. greater than the feed temperature.

2. The method of claim 1, wherein the temperature during the exposing is at least 10° C. greater than the feed temperature.

3. The method of claim 1, wherein the effective dewaxing conditions comprise an LHSV of about 1.0 hr−1 to about 10 hr−1 relative to the dewaxing catalyst.

4. The method of claim 1, wherein the olefin co-feed comprises 0.5 wt % to 5 wt % of C2-C4 olefins, or wherein the olefin co-feed comprises 2 wt % to 20 wt % of C5-C9 olefins.

5. The method of claim 1, wherein the effective dewaxing conditions comprise a pressure of from about 200 psig (1.4 MPag) to about 1500 psig (10.4 MPag), a temperature of from about 288° C. to about 440° C., a hydrogen treat gas rate of about 500 scf/bbl (84 Nm3/m3) to about 4000 scf/bbl (674 Nm3/m3) or less, and a LHSV of from about 0.3 hr−1 to about 10 hr−1 relative to the dewaxing catalyst.

6. The method of claim 5, wherein the effective dewaxing conditions comprise a pressure of at least about 400 psig (˜2.8 MPag) and a temperature of at least about 343° C.

7. The method of claim 1, wherein the feed comprises about 15 wt % or less aromatics.

8. The method of claim 1, further comprising exposing a feedstock comprising an organic sulfur content of 200 wppm to 12000 wppm to a hydrotreating catalyst to form a hydrotreated effluent comprising the distillate fuel boiling range fraction, wherein exposing the feed to a dewaxing catalyst comprises exposing at least a portion of the hydrotreated effluent to the dewaxing catalyst.

9. The method of claim 8, wherein the effective hydrotreating conditions comprise a pressure of from about 200 psig (1.4 MPa) to about 3000 psig (20.7 MPa), a temperature of from about 500° F. (260° C.) to about 800° F. (427° C.), a hydrogen treat gas rate of about 500 SCF/B (84 Nm3/m3) to about 10000 SCF/B (1685 Nm3/m3) and a space velocity of from about 0.3 hr−1 to about 5.0 hr−1.

10. The method of claim 1, wherein a) the metal hydrogenation component comprises Pt, Pd, or a combination thereof; b) the zeolitic framework comprises an MRE framework structure, an MTT framework structure, ZSM-48, ZSM-23, or a combination thereof; or c) a combination of a) and b)

11. The method of claim 1, wherein the dewaxing catalyst further comprises a binder, the binder optionally comprising alumina, silica, silica-alumina, titania, zirconia, or a combination thereof.

12. The method of claim 1, wherein the feed has a T5 boiling point of at least about 300° F. (149° C.) and a T95 boiling point of about 800° F. (371° C.) or less, or wherein the feedstock has a T5 boiling point of at least about 300° F. (149° C.) and a T95 boiling point of about 800° F. (371° C.) or less, or a combination thereof.

13. A method for producing distillate fuel products, comprising:

exposing a feedstock comprising an organic sulfur content of 200 wppm to 12000 wppm to a hydrotreating catalyst to form a hydrotreated effluent comprising a distillate fuel boiling range fraction, the hydrotreated effluent comprising an effluent temperature an organic sulfur content of 100 wppm or less (or 20 wppm or less or 10 wppm or less); and

exposing at least a portion of the distillate fuel boiling range fraction and an olefin co-feed to a dewaxing catalyst comprising a crystalline structure having a zeolitic framework and a metal hydrogenation component under effective dewaxing conditions to produce a dewaxed effluent having a cloud point that is reduced relative to a cloud point of the feed by at least 2° C. (or at least 5° C., or at least 10° C.), the feed comprising an organic sulfur content of about 100 wppm or less (or about 20 wppm or less, or about 10 wppm or less) and having a feed temperature prior to the exposing, the olefin co-feed comprising 0.5 wt % to 20 wt % of C2-C9 olefins based on a weight of the distillate fuel boiling range fraction, the temperature during the exposing being at least 3° C. greater than the effluent temperature.

14. The method of claim 13, wherein the effective dewaxing conditions comprise an LHSV of about 1.0 hr−1 to about 6.0 hr−1 relative to the dewaxing catalyst.

15. The method of claim 13, wherein the olefin co-feed comprises 1.0 wt % to 4.0 wt % of C3 olefins, C4 olefins, or a combination thereof.

16. The method of claim 13, wherein at least a portion of the hydrotreating catalyst and at least a portion of the dewaxing catalyst comprise a catalyst bed.

17. The method of claim 13, wherein the olefin co-feed comprises a portion of an FCC effluent stream comprising C3 olefins, C4 olefins, or a combination thereof.

18. The method of claim 13, wherein exposing the feedstock comprising an organic sulfur content to a hydrotreating catalyst comprises exposing the feedstock comprising an organic sulfur content and an olefin co-feed to the hydrotreating catalyst.

19. A dewaxed effluent comprising about 86 wt % to about 96 wt % of a distillate boiling range fraction relative to a total hydrocarbon content of the dewaxed effluent, about 1 wt % to about 3 wt % of a naphtha boiling range fraction, and about 3 wt % to about 11 wt % of propane, butane, or a combination thereof, the distillate boiling range fraction having a cloud point of −20° C. or less.

20. The dewaxed effluent of claim 19, wherein the dewaxed effluent comprises about 5 wt % to about 10 wt % of propane, butane, or a combination thereof.