US20190144763A1

US20190144763A1 - Removal of silicon-containing chemicals from hydrocarbon streams

Info

Publication number: US20190144763A1
Application number: US16/180,597
Authority: US
Inventors: Mustafa AL-SABAWI; Lindsay A. MITCHELL
Original assignee: ExxonMobil Research and Engineering Co
Current assignee: ExxonMobil Technology and Engineering Co
Priority date: 2017-11-13
Filing date: 2018-11-05
Publication date: 2019-05-16
Also published as: CA3077234A1; WO2019094328A1

Abstract

Methods of removing silicon-containing (organosilicon) compounds from petroleum-based feedstreams are disclosed herein. The methods can include providing a petroleum-based feedstream having a first silicon content of at least 1.0 wppm, and filtering the petroleum-based feedstream to yield a permeate having a second silicon content lower than the first silicon content, wherein the second silicon content is at least 25% lower than the first silicon content, the second silicon content is less than 1.0 wppm, or both.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to U.S. Provisional Application No. 62/585,037 filed Nov. 13, 2017, which is herein incorporated by reference in its entirety.

FIELD

The present disclosure relates to methods for removing silicon-containing compounds, such as anti-foaming agents, from petroleum-based streams to simplify refinery and/or further treatment, optionally to ultimately form a fuel or lubricant product.

BACKGROUND

Chemical additives are often utilized in crude oil production to increase resource recovery and optimize the handling and delivery of crude oil. Various types of chemicals or mixtures are often used to aid the production, handling, and transportation of crude oil. Most of the time, only trace amounts of such chemicals (in parts per million or parts per billion quantities) may remain in crude oil as impurities once the crude reaches the refinery.
Foaming problems occur in many oilfield processes. Anti-foaming agents are one type of chemical used to mitigate such problems. These agents, which are typically oil-soluble silicon-containing chemicals such as polysiloxanes (e.g., PDMS), when present in crude oil, pose issues for refiners because some silicon-containing chemicals can degrade the quality of refinery products, including gasoline and distillates. Moreover, silicon is a known poison for catalysts in refinery reactors/units. Thus, removal of these silicon-containing chemicals can be important for mitigating issues in refineries and downstream operations. Despite having a relatively high boiling range, polysiloxane anti-foaming agents can readily thermally decompose, for example at about 300-350° C., into lighter cyclic products (e.g., hexamethyl-cyclotrisiloxane) that have similar boiling point ranges to fuels and fuel precursors, such as naphtha, jet fuel, and diesel. These decomposition products are generally considered detrimental to catalysts, catalytic processes, and fuels products.
The injection of silicon-containing additives in delayed cokers to control foaming is also common. This is another common source of silicon contaminant in a refinery that can cause catalysts, processing, and refinery product issues.
While refinery desalter technology may remove some silicon-containing chemicals, others typically remain in the oil-phase after the desalting process. These chemicals can typically decompose at high temperatures, such as in refinery furnaces, crude towers, and cokers. The decomposition products may then be distributed across wide boiling-point distribution range refinery streams, becoming a threat to catalysts, processing, and finished products.
The present invention proposes filtration as an effective technology to remove silicon-based additives (i.e. organic silicon) from crude oil and refinery streams. It has been found that these chemicals may be only partially soluble in hydrocarbons, even though they are not effectively removed by refinery desalters. Consequently, utilization of conventional solids removal methods, such as filtration, allows for removal of silicon-based chemicals.

SUMMARY

This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
One aspect of the invention involves a method of removing organosilicon compounds from a petroleum-based feedstream. The method can comprise: providing a petroleum-based feedstream having a first silicon content of at least 1.0 wppm; and filtering the petroleum-based feedstream to yield a permeate having a second silicon content lower than the first silicon content. In many embodiments, the second silicon content is at least 25% lower than the first silicon content, the second silicon content is less than 1.0 wppm, or both. In some embodiments, the second silicon content is less than 1.0 wppm and at least 50% lower than the first silicon content.
Examples of the petroleum-based feedstream can include, but are not necessarily limited to, a bituminous crude oil, a diluted heavy crude oil, an at least partially deasphalted heavy crude oil, a diluted and at least partially deasphalted heavy crude oil, a fracked crude oil, a tight oil, a bottoms stream from a refinery distillation separator, an off-spec fuel stream, an off-spec lubricant stream, and combinations thereof.
In a first set of embodiments, the petroleum-based feedstream can exhibit one or more (e.g., two or more, three or more, four or more, or all five) enumerated characteristics: a solids content of at least 0.5 wt %; an insolubility number (IN) of at least 18; a solubility blending number (SBN) of 80 or less; a difference between SBN and IN of at least 20; and a silicon content of at least 1.3 wppm. In a second set of embodiments, the petroleum-based feedstream can exhibit one or more (e.g., two or more, three or more, four or more, or all five) enumerated characteristics: a solids content less than 0.5 wt %; an insolubility number (IN) less than 18; a solubility blending number (SBN) of greater than 80; a difference between SBN and IN of less than 20; and a silicon content of at least 1.5 wppm.
In either set of embodiments, but particularly in the second set of embodiments, the method can further comprise adding solids (e.g., comprising silica, alumina, a silicate, an aluminosilicate, sand, a silicon-containing clay, an aluminum-containing clay, hydrocarbon conversion catalyst fines, at least partially spent hydrocarbon conversion catalyst fines, a zeolite, or a combination thereof) to the petroleum-based feedstream to form a solids-enriched petroleum-based feedstream before the filtering step, which then filters the solids-enriched petroleum-based feedstream. In such embodiments, optionally the solids-enriched petroleum-based feedstream can have a solids content of at least 0.5 wt %, and optionally the permeate from the filtering step can additionally exhibit a solids content of 0.2 wt % or less.
In either set of embodiments, but particularly in the second set of embodiments, the method can further comprise blending the petroleum-based feedstream with a petroleum-based blendstock to form a petroleum-based blended stream before the filtering step, which then filters the petroleum-based blended stream. In such embodiments, the petroleum-based blended stream can retain a silicon content of at least 1.3 wppm and can exhibit one or more (e.g., two or more, three or more, or all four) enumerated characteristics: a solids content of at least 0.5 wt %; an insolubility number (IN) of at least 18; a solubility blending number (SBN) of 80 or less; and a difference between SBN and IN of at least 20. In such embodiments, optionally the permeate from the filtering step can additionally exhibit a solids content of 0.2 wt % or less.
In some embodiments, the filtering step can utilize a porous solid filter made of a material that has substantially no catalytic activity for hydrocarbon conversion (e.g., comprising a polymer with repeat units comprising an amine, an amide, an ester, an ether, an imine, a urethane, a urea, a siloxane, polymerized ethylene, polymerized propylene, a polymerized styrenic, a polymerized diene, a polymerized acrylate, a polymerized acetate, or a combination thereof) and having a pore size of 1 micron or less.
In some embodiments, the filtering step is conducted at a temperature between 0° C. and 225° C., at a pressure between 50 kPaa and 2.2 MPaa, or both.
In some embodiments, the organosilicon compounds accounting for at least 10% of the first silicon content have a high molecular weight corresponding to a viscosity of at least 25000 cPs, e.g., between 50000 cPs and 1000000 cPs.
In some embodiments, the method can further comprise a distilling step before the filtering step, wherein the distilling step yields the petroleum-based feedstream as a side draw or as a bottoms stream.
In some embodiments, the permeate is further subject to one or more catalytic hydrocarbon conversion refinery processes to form an unadditized fuel/lubricant product or blendstock selected from the group consisting of motor gasoline, diesel fuel, kerosene, jet fuel, avgas, Group I lubricant, Group II lubricant, Group III lubricant, Group IV lubricant, Group V lubricant, a biofuel, a biolubricant, and combinations thereof.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DETAILED DESCRIPTION

With the increase in crude oil production involving non-conventional techniques (such as horizontal drilling, hydraulic fracturing, oil sands mining, etc.), the use of silicon-containing chemicals such as anti-foaming agents during production has also increased, particularly due to such non-conventional production techniques. Many crude oils, including tight oils and oil-sand crudes (diluted bitumens), can therefore contain these silicon-containing chemicals. As refinery operators know, much of the silicon-containing chemicals remain in crude oil after any desalting or other on-site treatment. Upon reaching temperatures of about 300° C. to about 350° C., many silicon-containing antifoaming agents can tend to breakdown into lighter decomposition products with boiling points within typical fuel/distillate ranges and have been found to be difficult to separate from such fuel/distillate boiling range refinery cuts by distillation alone. Typical decomposition products can include, but are by no means limited to, cyclic siloxanes, organosilanes, and partially or completely oxidized silicon-containing compounds. Cyclic siloxanes can comprise a majority of the decomposition products of the organosilicon compounds, with some of the most problematic including those species having boiling points in the motor gasoline, jet fuel, kerosene, and/or diesel fuel ranges. For example, select cyclic siloxane decomposition products can have boiling points of about 134° C., about 176° C., about 210° C., and about 245° C.

Silicon Content

An aspect of the present invention therefore involves a method of removing silicon-containing compounds, such as organosilicon compounds, from a petroleum-based feedstream. The method may include providing a petroleum-based feedstream having a first silicon content of at least 1.0 wppm (e.g., at least 1.3 wppm, at least 1.6 wppm, at least 2.0 wppm, at least 2.5 wppm, at least 3.0 wppm, at least 3.5 wppm, at least 4.0 wppm, at least 4.5 wppm, at least 5.0 wppm, at least 6.0 wppm, at least 7.0 wppm, at least 8.0 wppm, at least 9.0 wppm, at least 10 wppm, at least 15 wppm, at least 20 wppm, at least 25 wppm, at least 30 wppm, at least 35 wppm, at least 40 wppm, at least 45 wppm, or at least 50 wppm; optionally, in certain embodiments, the petroleum-based feedstream may additionally have a first silicon content of at most 1000 wppm, e.g., at most 500 wppm, at most 300 wppm, at most 200 wppm, at most 150 wppm, at most 120 wppm, at most 100 wppm, at most 90 wppm, at most 80 wppm, at most 70 wppm, at most 60 wppm, at most 50 wppm, at most 45 wppm, at most 40 wppm, at most 35 wppm, at most 30 wppm, at most 25 wppm, or at most 20 wppm).
Additionally, the method may also include filtering the petroleum-based feedstream to yield a permeate having a second silicon content lower than the first silicon content. In some embodiments, the second silicon content can be (i) at least 25% lower than the first silicon content (e.g., at least 30% lower, at least 35% lower, at least 40% lower, at least 45% lower, at least 50% lower, at least 55% lower, at least 60% lower, at least 65% lower, at least 70% lower, at least 75% lower, at least 80% lower, at least 85% lower, at least 90% lower, or at least 95% lower), (ii) less than 1.0 wppm (alternatively, less than 2.0 wppm, less than 1.8 wppm, less than 1.6 wppm, less than 1.4 wppm, less than 1.3 wppm, less than 1.2 wppm, or less than 1.1 wppm), based on the weight of the permeate, or (iii) both (i) and (ii). Additionally or alternatively, the second silicon content can be up to 99% lower than the first silicon content (e.g., up to 97% lower, up to 95% lower, up to 90% lower, up to 85% lower, up to 80% lower, up to 75% lower, up to 70% lower, up to 65% lower, up to 60% lower, up to 55% lower, up to 50% lower, up to 45% lower, or up to 40% lower). In a particular embodiment, the second silicon content can be less than 1.0 wppm and at least 50% lower than the first silicon content. These percentage values are by weight, unless otherwise specified or unless the context dictates otherwise.
Optionally, in some embodiments, the filtering step may additionally yield a retentate having a third silicon content higher than the first silicon content. In some embodiments, the retentate may be recycled as a portion of a feedstream to a delayed coker, for example as a delayed coker antifoam additive (due to its content of organosilicon).

Silicon Content Measurement Techniques

Silicon content in compositions such as the petroleum-based feedstreams/permeates of the methods according to the invention can be measured and/or calculated using any reasonable technique. One example technique includes an inductively coupled plasma (ICP) instrument, which usually works in tandem with one or more other instruments, such as atomic emission spectroscopy (AES), optical emission spectroscopy (OES), mass spectrometry (MS), x-ray fluorescence (XRF), or the like. As reported herein, ASTM 5815 can be used, along with ICP-AES analysis, to attain silicon contents of various streams/compositions.

Silicon-Containing Compounds

In many embodiments, the silicon-containing compounds to be removed from the petroleum-based feedstream can include organosilicon compounds, such as antifoaming agents, that have a relatively high molecular weight, as indicated by a relatively high viscosity. These organosilicon compounds may be all, most, or a portion of the silicon-containing compounds in the hydrocarbon compositions of various streams herein. In some embodiments, the organosilicon compounds accounting for at least 5 wt % of the first silicon content (e.g., at least 10 wt %, at least 20 wt %, at least 30 wt %, at least 40 wt %, at least 50 wt %, more than 50 wt %, at least 60 wt %, at least 70 wt %, at least 75 wt %, at least 80 wt %, at least 85 wt %, at least 90 wt %, at least 95 wt %, at least 97 wt %, at least 98 wt %, at least 99 wt %, or approximately 100 wt %) can have a molecular weight corresponding to a viscosity of at least about 15000 cPs (e.g., at least about 25000 cPs, at least about 35000 cPs, at least about 45000 cPs, at least about 50000 cPs, at least about 55000 cPs, at least about 60000 cPs, at least about 65000 cPs, at least about 70000 cPs, at least about 75000 cPs; optionally also up to about 1500000 cPs, up to about 1000000 cPs, up to about 850000 cPs, up to about 700000 cPs, up to about 600000 cPs, up to about 500000 cPs, up to about 400000 cPs, up to about 300000 cPs, or up to about 250000 cPs). In a particular embodiment, the organosilicon compounds accounting for at least 10 wt % of the first silicon content can have a molecular weight corresponding to a viscosity of between 50000 cPs and 1000000 cPs. In another particular embodiment, the organosilicon compounds accounting for at least 75 wt % of the first silicon content can have a molecular weight corresponding to a viscosity of between 50000 cPs and 1000000 cPs.
Although the filtering step may be effective in removing many silicon-containing compounds from the feedstream (thus creating a reduced silicon content in the permeate), one focus of the filtering step is to specifically remove organosilicon compounds. That is not to say that removing inorganic silicon-containing compounds is unimportant. However, inorganic silicon-containing compounds can tend not to be highly soluble in feedstreams such as the petroleum-based (organic) feedstreams being input into the filtering step. The efficacy of filtration to remove largely insoluble silicon-containing compounds is well-documented. Nevertheless, the efficacy of filtration to remove somewhat soluble organosilicon compounds from petroleum-based (organic) feedstreams is not believed to be well-known. As a result, in some embodiments, the organosilicon compounds can comprise polysiloxanes having the following structure:
In such polysiloxanes, “n” can represent the number of siloxane repeat units, which can be measured by a variety of methods (viscosity being described hereinabove, in which case “n” would be described by the number of repeat units needed to attain a given viscosity/range). Also in such polysiloxanes, the pendant groups R′ and R″ for each repeat unit may independently or collectively be similar or different amongst each polysiloxane repeat unit and may comprise or be a hydrocarbonaceous moiety optionally containing one or more oxygen, nitrogen, or sulfur atoms. Although it is possible for some of R′ and/or R″ to be inorganic moieties, such as —OH, —NH₂, —SH, or the like, such functionality is typically not intentionally sought. It is typically present via oxidation or some other minor thermochemical side reaction, and typically encompasses less than about 2 wt % of all R′+R″ groups, e.g., less than about 1 wt %, less than about 0.5 wt %, or less than about 1 wt %.
In some embodiments, R′ and R″ can each individually comprise or be a C₁-C₄₀hydrocarbon moiety (e.g., C₁-C₃₀, C₁-C₂₀, C₁-C₁₂, or C₁-C₆), optionally containing one or more heteroatoms comprising O, N, and/or S. In an embodiment, most or substantially all of the R′ and R″ pendant groups can be —CH₃, such that the polysiloxane can be polydimethylsiloxane or a copolymer containing predominantly dimethylsiloxane repeat units. Hydrocarbon and hydrocarbonaceous moieties may be aliphatic, be aromatic, be a combination of aromatic and aliphatic, contain a C═C double bond, contain a C═C triple bond, be conjugated, or some combination thereof. Additionally or alternatively, hydrocarbon and hydrocarbonaceous moieties may be linear, cyclic, branched, crosslinked (i.e., connecting at least two repeat unit silicon atoms to each other using a single hydrocarbon or hydrocarbonaceous moiety), interconnected (i.e., connecting a single silicon atom through two single bonds to a cyclic moiety representing a combination of R′ and R″), crosslinked and interconnected, or a combination thereof.

Filtration Step/Filter

The filtration step can be carried out at any convenient temperature and pressure. However, because certain silicon-containing chemicals (such as antifoaming agents) can begin decomposing into highly undesirable by-products at temperatures as low as about 300° C. at approximately atmospheric pressure (about 0 psig or about 0 kPag), the temperature and pressure of the filtration step may be limited accordingly. In some embodiments, the filtering step can be conducted at a temperature of about 280° C. or less, e.g., about 270° C. or less, about 260° C. or less, about 250° C. or less, about 240° C. or less, about 230° C. or less, about 220° C. or less, about 210° C. or less, about 200° C. or less, about 180° C. or less, about 165° C. or less, about 150° C. or less, about 135° C. or less, about 120° C. or less, about 105° C. or less, about 90° C. or less, about 80° C. or less, about 70° C. or less, about 60° C. or less, about 50° C. or less, about 40° C. or less, or about 30° C. or less.
Additionally or alternatively, the filtering step can be conducted at a temperature of at least about −80° C., at least about −65° C., at least about −50° C., at least about −35° C., at least about −20° C., at least about −10° C., at least about 0° C., at least about 5° C., at least about 10° C., at least about 15° C., at least about 20° C., at least about 25° C., at least about 30° C., at least about 40° C., at least about 50° C., at least about 60° C., at least about 70° C., at least about 80° C., at least about 90° C., at least about 105° C., at least about 120° C., at least about 135° C., or at least about 150° C.
Further additionally or alternatively, the filtering step can be conducted at a pressure of about 20 MPaa or less, e.g., about 15 MPaa or less, about 10 MPaa or less, about 5.1 MPaa or less, about 3.1 MPaa or less, about 2.2 MPaa or less, about 1.7 MPaa or less, about 1.2 MPaa or to less, about 800 kPaa or less, about 500 kPaa or less, about 300 kPaa or less, about 200 kPaa or less, or about 100 kPaa or less. Still further additionally or alternatively, the filtering step can be conducted at a pressure of at least about 5 kPaa, at least about 10 kPaa, at least about 25 kPaa, at least about 50 kPaa, at least about 75 kPaa, at least about 100 kPaa, at least about 200 kPaa, at least about 300 kPaa, at least about 500 kPaa, or at least about 800 kPaa. In a particular embodiment, the filtering step can be conducted at a temperature between 0° C. and 225° C. and/or at a pressure between 50 kPaa and 2.2 MPaa.
In some embodiments, the filtering step can utilize a porous solid filter made of a material that has substantially no catalytic activity for hydrocarbon conversion. In some embodiments, the filtering step can utilize a filter that is distinct from a guard bed (alternatively termed a silicon trap). This is not to say that a guard bed (or silicon trap) cannot be used in addition to the filter—the porous solid filter material described herein should merely be understood to be distinct from a guard bed (or silicon trap). In various embodiments, the porous solid filter can include or be made from a polymer with repeat units comprising an amine, an amide, an ester, an ether, an imine, a urethane, a urea, a siloxane, polymerized ethylene, polymerized propylene, a polymerized styrenic, a polymerized diene, a polymerized acrylate, a polymerized acetate, or a combination thereof.
Additionally or alternatively, the porous solid filter can have a pore size of 1.5 microns or less, e.g., 1.3 microns or less, 1.1 microns or less, 1 micron or less, 0.9 microns or less, 0.8 microns or less, 0.7 microns or less, 0.6 microns or less, 0.5 microns or less, 0.4 microns or less, or 0.3 microns or less. Further additionally or alternatively, the porous solid filter can have a pore size of at least 0.1 microns, at least 0.2 microns, at least 0.3 microns, at least 0.4 microns, at least 0.5 microns, at least 0.6 microns, at least 0.7 microns, at least 0.8 microns, or at least 0.9 microns.

Feed Streams

The petroleum-based feedstreams from which organosilicon compounds may be desirably removed may include varieties of crude oils into which silicon-containing compounds, such as antifoaming agents, were added to assist in production; varieties of crude oils that have been contaminated by exposure to silicon-containing compounds (e.g., via storage or transport, such as in a tank, through a pipeline, or the like); refinery streams (including distilled fractions, converted hydrocarbon streams, treated hydrocarbon streams, recycle streams, or the like, or combinations thereof) that have been contaminated by exposure to silicon-containing compounds; off-specification (off-spec) products, or the like. In some embodiments, the petroleum-based feedstream can include, but need not be limited to, a bituminous crude oil, a diluted heavy crude oil, an at least partially deasphalted heavy crude oil, a diluted and at least partially deasphalted heavy crude oil, a fracked crude oil, a tight oil, a bottoms stream from a refinery distillation separator, a kerosene boiling range stream, a jet fuel boiling range stream, an off-spec fuel stream, an off-spec lubricant stream, or a combination thereof.

Optional Steps

Distillation
In some embodiments, such as when the petroleum-based feedstream is a whole crude oil or a wide boiling fraction of a crude oil (e.g., a partially but not completely distilled and/or refined crude oil), the filtering step may optionally be preceded by a distilling step. In such embodiments, the distilling step can yield the petroleum-based feedstream as a product, for example, as a bottoms stream, as a side draw, or as some combination thereof. In some embodiments, such as when the petroleum-based feedstream is a whole crude oil or a wide boiling fraction of a crude oil (e.g., a partially but not completely distilled and/or refined crude oil), the filtering step may be followed by one or more refinery distillation steps, (hydro)conversion steps, (hydro)treatment or (hydro)processing steps, blending steps, or other desired activity to be carried out on the permeate. In such embodiments, the permeate may be further subject to one or more catalytic hydrocarbon conversion refinery processes to form an unadditized fuel/lubricant product or blendstock selected from the group consisting of motor gasoline, diesel fuel, kerosene, jet fuel, avgas, Group I lubricant, Group II lubricant, Group III lubricant, Group IV lubricant, Group V lubricant, a biofuel, a biolubricant, and combinations thereof. In some embodiments, the retentate may be further treated to reduce its silicon content or may be recycled with little or no treatment as a portion of a feedstream to a delayed coker, for example as a delayed coker antifoam additive (due to its content of organosilicon).
Adding Solids
Further, a wide variety of properties and characteristics can define the petroleum-based feedstream prior to the filtering step. Indeed, some properties and characteristics can indicate a likelihood of a very successful method of organosilicon removal, such as the percentage reduction in silicon content between permeate and feedstream and/or the absolute reduction in silicon content from the permeate to the feedstream below a desired level. In situations indicative of a high likelihood of success in organosilicon removal, no silicon-related treatment steps may be needed or conducted prior to the filtration step. In situations not indicative of a high likelihood of success in organosilicon removal, or even in the occasional case indicating a high likelihood of success, it may be desired to take additional steps in order to raise the likelihood of success in organosilicon removal. Nevertheless, in order to distinguish between the two types of situations, it can be useful to categorize the properties and/or characteristics of petroleum-based feedstreams that tend toward and away from high likelihood of success in organosilicon removal.
Without being bound by theory, petroleum-based feedstreams exhibiting one or more (e.g., two or more, three or more, four or more, or all) of the following enumerated properties can have a relatively high likelihood of success: a solids content of at least 0.5 wt % (e.g., at least 0.6 wt %, at least 0.7 wt %, at least 0.8 wt %, at least 0.9 wt %, or at least 1.0 wt %); an insolubility number (IN) of at least 10 (e.g., at least 12, at least 15, at least 17, at least 20, at least 22, at least 25, at least 27, at least 30, or at least 32); a solubility blending number (SBN) of 90 or less (e.g., 85 or less, 80 or less, 75 or less, or 70 or less); a difference between SBN and IN of at least 15 (e.g., at least 20, at least 25, at least 30, or at least 35); and a silicon content of at least 1.3 wppm (e.g., at least 1.5 wppm, at least 1.7 wppm, at least 1.9 wppm, at least 2.1 wppm, at least 2.3 wppm, at least 2.5 wppm, or at least 2.8 wppm). For clarity, it should be understood that one or more of these properties may be necessary but not sufficient to predict absolute success in filtration for silicon content removal.
Also without being bound by theory, petroleum-based feedstreams exhibiting one or more (e.g., two or more, three or more, four or more, or all) of the following enumerated properties may not have a relatively high likelihood of success: a solids content of less than 3.0 wt % (e.g., less than 2.5 wt %, less than 2.0 wt %, less than 1.5 wt %, less than 1.0 wt %, less than 0.9 wt %, less than 0.8 wt %, less than 0.7 wt %, less than 0.6 wt %, or less than 0.5 wt %); an insolubility number (IN) of less than 30 (e.g., less than 27, less than 25, less than 22, less than 20, or less than 18); a solubility blending number (SBN) of greater than 70 (e.g., greater than 75, greater than 80, greater than 85, or greater than 90); a difference between SBN and IN of less than 25 (e.g., less than 20, less than 18, or less than 15); and a silicon content of at least 1.3 wppm (e.g., at least 1.5 wppm, at least 1.7 wppm, at least 1.9 wppm, at least 2.1 wppm, at least 2.3 wppm, at least 2.5 wppm, or at least 2.8 wppm). For clarity, it should be understood that one or more of these properties may be necessary but not sufficient to predict failure or significant problems in filtration for silicon content removal.
Therefore, in some embodiments, the method may include adding solids to a petroleum-based feedstream, for example a feedstream having any of the enumerated properties discussed above, to form a solids-enriched petroleum-based feedstream before the filtering step. In such embodiments, the filtering step can then filter the solids-enriched petroleum-based feedstream instead of merely the petroleum-based feedstream. Additionally in such embodiments, the solids-enriched petroleum-based feedstream to be sent to the filtering step can exhibit a solids content of at least 0.5 wt % (e.g., at least 0.6 wt %, at least 0.7 wt %, at least 0.8 wt %, at least 0.9 wt %, or at least 1.0 wt %), and the permeate obtained from the filtering step can exhibit a solids content of 0.2 wt % or less (e.g., 0.15 wt % or less, 0.1 wt % or less, 0.05 wt % or less, 0.01 wt % or less, 50 wppm or less, or 20 wppm or less). In some embodiments, the added solids may contain or be formed from silica, alumina, a silicate, an aluminosilicate, sand, a silicon-containing clay, an aluminum-containing clay, hydrocarbon conversion catalyst fines, at least partially spent hydrocarbon conversion catalyst fines, a zeolite, or a combination thereof.
Without being bound by theory, it is believed that maintaining a certain level of immiscibility, and thus a certain level of solids content, in a stream leading into the filtration step can be advantageous, as it is postulated herein that certain insoluble portions of the filtration feedstream can provide an alternatively miscible environment for the silicon-containing compounds, which can thus lead to enhanced filtration efficacy. Although such insoluble portions of the feedstream may comprise or be highly inorganic silicon-containing solids (e.g., silica and/or metallosilicate particulates such as aluminosilicates), other highly organic insoluble compounds (e.g., those compounds having increased heteroatom content and/or aromatic character, relative to the remainder of the feedstream, such as asphaltenes) can additionally or alternatively provide a more miscible environment for organosilicon-type compounds. By preferentially associating with an insoluble fraction, the organosilicon-type compounds can therefore be more easily removed from the feedstream, rendering the permeate following filtration not only considerably lower in solids content but also advantageously lower in silicon content, preferably having a silicon content at or below the desired specification (e.g., about 1.0 wppm). If a feedstream does not contain enough solids/insolubles and/or exhibits too high a miscibility for silicon-containing compounds (e.g., organosilicon-type compounds such as anti-foaming agents), the effectiveness of the filtration may undesirably decrease. By blending in phase separating/immiscible components, or a blendstock containing them, it is believed that filtration effectiveness and efficiency for silicon-containing compounds can be counterintuitively enhanced.
Blending with Blendstock
Additionally or alternatively, in some embodiments, the method may include blending the petroleum-based feedstream with a petroleum-based blendstock to form a petroleum-based blended stream before the filtering step. In such embodiments, the filtering step can then filter the petroleum-based blended stream instead of merely the petroleum-based feedstream. Additionally in such embodiments, the petroleum-based blended stream to be sent to the filtering step can retain a silicon content of at least 1.3 wppm and can exhibit one or more of the following enumerated characteristics: a solids content of at least 0.5 wt % (e.g., at least 0.6 wt %, at least 0.7 wt %, at least 0.8 wt %, at least 0.9 wt %, or at least 1.0 wt %); an insolubility number (IN) of at least 10 (e.g., at least 12, at least 15, at least 17, at least 20, at least 22, at least 25, at least 27, at least 30, or at least 32); a solubility blending number (SBN) of 90 or less (e.g., 85 or less, 80 or less, 75 or less, or 70 or less); and a difference between SBN and IN of at least 15 (e.g., at least 20, at least 25, at least 30, or at least 35).
In some embodiments, the permeate from the filtering step can exhibit a solids content of 0.2 wt % or less (e.g., 0.15 wt % or less, 0.1 wt % or less, 0.05 wt % or less, 0.01 wt % or less, 50 wppm or less, or 20 wppm or less).
In this discussion, insolubility number (IN) can correspond to n-heptane insoluble compounds, as can be characterized using ASTM D6560. Such n-heptane insoluble compounds (e.g., asphaltenes) can typically be understood as compounds insoluble in n-heptane while typically being soluble in toluene, under the conditions set forth in ASTM D6560. According to the ASTM standard, if less than 0.5 mass % of a sample yields insoluble solids in n-heptane at the appropriate conditions, the test outcome is noted to be completely n-heptane soluble (IN ˜0). It is noted, however, that certain petroleum-based compounds (e.g., asphaltenes or asphaltene-type compounds) can also be at least partially identified by their solubility/insolubility in one or more other solvents. Such alternative solvents can include, but are not limited to, other C₃-C₇alkanes, toluene, or combinations thereof.
Although the insolubility number of a fuel oil sample can be characterized directly, such as by using ASTM D6560, other methods of characterization can additionally or alternatively be used. For example, another method for characterizing a petroleum-based feedstreams can be based on a Micro Carbon Residue (MCR) test, such as according to ISO 10370. In an exemplary MCR test, about 4 grams of a sample can be put into a weighed glass bulb. The sample in the bulb can then be heated in a bath at about 553° C. for about 20 minutes. After cooling, the bulb can be weighed again and the difference noted. While the MCR test approximates organic residue from relatively high-temperature oxidation and does not provide a direct measure of the content of all insolubles, the MCR value is generally believed to be highly correlated with the tendency of a petroleum-based composition/fraction to form coke, and therefore may provide an alternate/approximate indication of the content of certain highly organic compounds (e.g., asphaltenes).
An additional/alternative method of characterizing the solubility properties of a petroleum-based feedstreams can correspond to the toluene equivalence (TE) of a fuel oil, based on the toluene equivalence test as described, for example, in U.S. Pat. No. 5,871,634, which is incorporated herein by reference with regard to the definitions for and descriptions of toluene equivalence, solubility number (SBN), and insolubility number (IN).
The above test method for the toluene equivalence test can be expanded to allow for determination of a solubility number (SBN) and an insolubility number (IN) for a petroleum-based feedstream sample. If it is desired to determine SBN and/or IN for a petroleum-based feedstream sample, the toluene equivalence test described above can be performed to generate a first data point corresponding to a first volume ratio R1 of petroleum-based composition to test liquid at a first percent of toluene T1 in the test liquid at the TE value. After generating the TE value, one option can be to determine a second data point by a similar process but using a different feedstream to test liquid mixture volume ratio. Alternatively, a percent toluene below that determined for the first data point can be selected and that test liquid mixture can be added to a known volume of the petroleum-based feedstream until certain highly organic compounds (e.g., asphaltenes) just begin to precipitate. At that point the volume ratio of feedstream to test liquid mixture, R2, at the selected percent toluene in the test liquid mixture, T2, can be used as the second data point. Since the accuracy of the final numbers can increase at greater distances between the data points, one option for the second test liquid mixture can be to use a test liquid containing 0% toluene or 100% n-heptane. This type of test for generating the second data point can be referred to as the heptane dilution test.
Based on the toluene equivalence test and heptane dilution test (or other test so that R1, R2, T1, and T2 are all defined), the insolubility and solubility numbers for a sample can be calculated based on Equations (2) and (3) in U.S. Patent Application Publication Number 2017/0044451, the contents of which are incorporated by reference herein, particularly regarding aspects of alternative miscibility testing such as toluene equivalence, heptane dilution, etc. As noted in U.S. Pat. No. 5,871,634, alternative methods are available for determining the solubility number of a petroleum-based feedstream that has an insolubility number of zero or approximately zero.
Again, without being bound by theory, it is noted that feedstream density can be an additional or alternative factor in establishing or determining the miscibility of a feedstream or blend. For instance, by blending in components containing a distinctly higher or lower density, or a blendstock containing them, it is believed that phase separation/immiscibility can be more easily induced in the resulting blend, thereby (again, counterintuitively) enhancing filtration effectiveness and efficiency for silicon-containing compounds.

Hydrotreating and Catalysts

In some embodiments, the petroleum-based blendstock may comprise or be: a whole or partial crude oil, whether including a measurable content of silicon-containing compounds (such as antifoaming agents) or not; a refinery stream (including any distilled fraction or portion thereof, converted hydrocarbon stream, treated hydrocarbon stream, recycle stream, or the like, or a combination thereof), whether including a measurable content of silicon-containing compounds or not; off-specification (off-spec) products, whether including a measurable content of silicon-containing compounds or not; on-specification (on-spec) products, which are typically but not necessarily unadditized; or the like. Converted and/or treated (hydroprocessed) hydrocarbon refinery streams may have been subject to hydrotreatment, hydrocracking, dewaxing/isomerization, hydrofinishing, or the like, or combinations thereof.
Hydrotreatment can typically include catalysts. Non-limiting examples of catalysts used for hydrotreatment can include conventional hydroprocessing catalysts, such as those that comprise at least one Group VIII non-noble metal (from Columns 8-10 of IUPAC periodic table), for example Fe, Co, and/or Ni (such as Co and/or Ni), and at least one Group VIB metal (from Column 6 of IUPAC periodic table), for example Mo and/or W. Such hydroprocessing catalysts can optionally include transition metal sulfides. These catalytically active metals or mixtures of metals can typically be present as oxides, sulfides, or the like, on supports such as refractory metal oxides. Suitable metal oxide supports can include low acidic oxides such as silica, alumina, titania, silica-titania, and titania-alumina, inter alia. Suitable aluminas can include porous aluminas (such as gamma or eta) having: average pore sizes from about 50 Å to about 200 Å, e.g., from about 75 Å to about 150 Å; a (BET) surface area from about 100 m²/g to about 300 m²/g, e.g., from about 150 m²/g to about 250 m²/g; and a pore volume from about 0.25 cm³/g to about 1.0 cm³/g, e.g., from about 0.35 cm³/g to about 0.8 cm³/g. The supports are, in certain embodiments, preferably not promoted with a halogen such as fluorine, as this can undesirably increase the acidity of the support.
The at least one Group VIII non-noble metal, as measured in oxide form, can typically be present in an amount ranging from about 2 wt % to about 40 wt %, for example from about 4 wt % to about 15 wt %. The at least one Group VIB metal, as measured in oxide form, can typically be present in an amount ranging from about 2 wt % to about 70 wt %, for example from about 6 wt % to about 40 wt % or from about 10 wt % to about 30 wt %. These weight percents are based on the total weight of the catalyst. Suitable catalysts can include CoMo (e.g., ˜1-10% Co as oxide, ˜10-40% Mo as oxide), NiMo (e.g., ˜1-10% Ni as oxide, ˜10-40% Mo as oxide), or NiW (e.g., ˜1-10% Ni as oxide, ˜10-40% W as oxide), supported on alumina, silica, silica-alumina, or titania.
Alternatively, the hydrotreating catalyst can include or be a bulk metal catalyst, or can include a combination of stacked beds of supported and bulk metal catalyst. By bulk metal, it is meant that the catalyst particles are unsupported and comprise about 30-100 wt % of at least one Group VIII non-noble metal and at least one Group VIB metal, based on the total weight of the bulk catalyst particles, calculated as metal oxides, which bulk catalyst particles can also have a (BET) surface area of at least 10 m²/g. For example, a bulk catalyst composition can include one Group VIII non-noble metal and two Group VIB metals. In some embodiments, the molar ratio of Group VIB to Group VIII non-noble metals can range generally from about 10:1 to about 1:10. In embodiments where more than one Group VIB metal is present in the bulk catalyst particles, the ratio of the different Group VIB metals is generally not critical. The same can hold when more than one Group VIII non-noble metal is present. Nevertheless, in embodiments where molybdenum and tungsten are present as Group VIB metals, the Mo:W ratio can preferably be in the range from about 9:1 to about 1:9.
Optionally, a bulk metal hydrotreating catalyst can have a surface area of at least 50 m²/g, for example at least 100 m²/g. Additionally or alternately, bulk metal hydrotreating catalysts can have a pore volume of about 0.05 ml/g to about 5 ml/g, for example about 0.1 ml/g to about 4 ml/g, about 0.1 ml/g to about 3 ml/g, or about 0.1 ml/g to about 2 ml/g, as determined by nitrogen adsorption. Bulk metal hydrotreating catalyst particles can additionally or alternatively have a median diameter of at least about 50 nm, e.g., at least about 100 nm, and/or a median diameter not more than about 5000 μm, e.g., not more than about 3000 μm. In an embodiment, the median particle diameter can be in the range of about 0.1 μm to about 50 μm, preferably about 0.5 μm to about 50 μm.
In typical embodiments, hydrotreating conditions can include: temperatures of about 200° C. to about 450° C., for example about 315° C. to about 425° C.; pressures of about 250 psig (˜1.8 MPag) to about 5000 psig (˜35 MPag), for example about 300 psig (˜2.1 MPag) to about 3000 psig (˜21 MPag); liquid hourly space velocities (LHSV) of about 0.1 hr⁻¹to about 10 hr⁻¹; and hydrogen treat gas rates of about 200 scf/B (˜36 m³/m³) to about 10000 scf/B (˜1800 m³/m³), for example about 500 scf/B (˜90 m³/m³) to about 10000 scf/B (˜1800 m³/m³).
In some aspects, hydrocracking catalysts can contain sulfided base metals on acidic supports, such as amorphous silica-alumina, cracking zeolites, or other cracking molecular sieves such as USY or acidified alumina. In some preferred aspects, a hydrocracking catalyst can include at least one molecular sieve, such as a zeolite. Often these acidic supports can be mixed and/or bound with other metal oxides such as alumina, titania, and/or silica. Non-limiting examples of supported catalytic metals for hydrocracking catalysts can include combinations of Group VIB and/or Group VIII non-noble metals, including Ni, NiCoMo, CoMo, NiW, NiMo, and/or NiMoW. Support materials which may be used can comprise a refractory oxide material such as alumina, silica, alumina-silica, kieselguhr, diatomaceous earth, magnesia, zirconia, or combinations thereof, with alumina, silica, and/or silica-alumina being the most common (and preferred, in some embodiments).
In such hydrocracking catalysts, the at least one Group VIII non-noble metal, as measured in oxide form, can be present in an amount typically ranging from about 2 wt % to about 40 wt %, e.g., from about 4 wt % to about 15 wt %. In such hydrocracking catalysts, the at least one Group VIB metal, as measured in oxide form, can additionally or alternatively be present in an amount typically ranging from about 2 wt % to about 70 wt %, e.g., for supported catalysts from about 6 wt % to about 40 wt % or from about 10 wt % to about 30 wt %. These weight percents are based on the total weight of the catalyst. In some aspects, suitable hydrocracking catalyst active metals can include NiMo, NiW, or NiMoW, typically supported.
Additionally or alternatively, hydrocracking catalysts with noble metals can be used. Non-limiting examples of noble metal catalysts can include those based on Pt and/or Pd. When the hydrogenation metal on a hydrocracking catalyst comprises or is a noble metal, the amount of the noble metal can be at least about 0.1 wt %, based on the total weight of the catalyst, for example at least about 0.5 wt % or at least about 0.6 wt %. Additionally or alternately, the amount of the noble metal can be about 5.0 wt % or less, based on the total weight of the catalyst, for example about 3.5 wt % or less, about 2.5 wt % or less, about 1.5 wt % or less, about 1.0 wt % or less, about 0.9 wt % or less, about 0.75 wt % or less, or about 0.6 wt % or less.
In some aspects, a hydrocracking catalyst can include a large pore molecular sieve selective for cracking of branched hydrocarbons and/or cyclic hydrocarbons. Zeolite Y, such as ultrastable zeolite Y (USY), is an example of a zeolite molecular sieve selective for cracking of branched hydrocarbons and cyclic hydrocarbons. Depending on the situation, the silica to alumina ratio (Si/Al₂, measured as oxides) in a USY zeolite can be at least about 10, for example at least about 15, at least about 25, at least about 50, or at least about 100. Depending on the situation, the unit cell size for a USY zeolite can be about 24.50 Å or less, e.g., about 24.45 Å or less, about 24.40 Å or less, about 24.35 Å or less, or about 24.30 Å. In certain situations, a variety of other types of molecular sieves can be used in a hydrocracking catalyst, such as zeolite Beta and/or ZSM-5. Still other categories of suitable molecular sieves can include molecular sieves having 10-member ring pore channels and/or 12-member ring pore channels. Examples of molecular sieves having 10-member ring pore channels and/or 12-member ring pore channels can include molecular sieves having one or more of the following zeolite framework types: MRE, MTT, EUO, AEL, AFO, SFF, STF, TON, OSI, ATO, GON, MTW, SFE, SSY, and VET.
In various embodiments, the conditions selected for hydrocracking can depend on the desired level of conversion, the level of contaminants in the input feed to the hydrocracking stage, and potentially other factors. Suitable hydrocracking conditions can include temperatures of about 450° F. (˜232° C.) to about 840° F. (˜449° C.), for example about 450° F. (˜232° C.) to about 800° F. (˜427° C.), about 450° F. (˜249° C.) to about 750° F. (^˜399° C.), about 500° F. (˜260° C.) to about 840° F. (˜449° C.), about 500° F. (˜260° C.) to about 800° F. (˜427° C.), or about 500° F. (˜260° C.) to about 750° F. (˜399° C.); hydrogen partial pressures from about 250 psig (˜1.8 MPag) to about 5000 psig (˜35 MPag); liquid hourly space velocities from about 0.05 hr⁻¹to about 10 hr⁻¹; and hydrogen treat gas rates from about 36 m³/m³(˜200 scf/B) to about 1800 m³/m³(˜10000 scf/B). In other embodiments, the conditions can include temperatures in the range of about 500° F. (˜260° C.) to about 815° F. (˜435° C.), for example about 500° F. (˜260° C.) to about 750° F. (˜399° C.) or about 500° F. (˜260° C.) to about 700° C. (˜371° C.); hydrogen partial pressures from about 500 psig (˜3.5 MPag) to about 3000 psig (˜21 MPag); liquid hourly space velocities from about 0.2 hr⁻¹to about 5 hr⁻¹; and hydrogen treat gas rates from about 210 m³/m³(˜1200 scf/B) to about 1100 m³/m³(˜6000 scf/B).
In some optional embodiments, a dewaxing catalyst can be used for dewaxing of a potential fuel oil. Suitable dewaxing catalysts can include molecular sieves such as crystalline aluminosilicates (zeolites). In an embodiment, the molecular sieve can comprise, consist essentially of, or be ZSM-5, ZSM-22, ZSM-23, ZSM-35, ZSM-48, zeolite Beta, ZSM-57, or a combination thereof (e.g., ZSM-23 and/or ZSM-48, or ZSM-48 and/or zeolite Beta). Optionally but preferably, molecular sieves selective for isomerization/dewaxing as opposed to cracking can be used, such as ZSM-48, zeolite Beta, and/or ZSM-23, inter alia. Additionally or alternately, the molecular sieve can comprise, consist essentially of, or be a 10-member ring 1-D molecular sieve, such as EU-1, ZSM-35 (or ferrierite), ZSM-11, ZSM-57, NU-87, SAPO-11, ZSM-48, ZSM-23, and/or ZSM-22. In some preferred embodiments, the dewaxing catalyst can include EU-2, EU-11, ZBM-30, ZSM-48, ZSM-23, isostructural versions thereof (e.g., Theta-1, NU-10, EU-13, KZ-1, and/or NU-23), and/or combinations or intergrowths thereof (particularly comprising or being ZSM-48). It should be noted that a ZSM-23 zeolite having a silica to alumina ratio from ^˜20:1 to ^˜40:1 can sometimes be referred to as SSZ-32. Optionally and in some embodiments preferably, the dewaxing catalyst can include a binder, such as alumina, titania, silica, silica-alumina, zirconia, or a combination thereof (e.g., alumina and/or titania or silica and/or zirconia and/or titania).
In certain preferred embodiments, when dewaxing catalysts are used, such dewaxing catalysts can have a low ratio of silica to alumina. For example, for ZSM-48, the ratio of silica to alumina in the zeolite can be less than about 200:1, for example less than about 110:1, less than about 100:1, less than about 90:1, or less than about 80:1, optionally at least about 30:1, at least about 50:1, at least about 60:1, or at least about 70:1. In various embodiments, the ratio of silica to alumina in the dewaxing catalyst can be from about 30:1 to about 200:1, about 60:1 to about 110:1, or about 70:1 to about 100:1.
In various embodiments, the catalysts in these processes can (further) include a metal hydrogenation component, which can typically include/be a Group VIB and/or Group VIII metal. Suitable combinations can include Ni/Co/Fe with Mo/W, e.g., NiMo or NiW. The amount of metal (from the metal hydrogenation component) in/on the catalyst can be at least about 0.1 wt % based on catalyst, e.g., at least about 0.15 wt %, at least about 0.2 wt %, at least about 0.25 wt %, at least about 0.3 wt %, or at least about 0.5 wt %, based on catalyst weight. Additionally or alternatively, the amount of metal (from the metal hydrogenation component) in/on the catalyst can be about 20 wt % or less, based on catalyst weight, e.g., about 10 wt % or less, about 5 wt % or less, about 2.5 wt % or less, or about 1 wt % or less.
Effective processing conditions in a catalytic dewaxing zone can include a temperature of about 200° C. to about 450° C., e.g., about 270° C. to about 400° C., a hydrogen partial pressure of about 1.8 MPag to about 35 MPag (˜250 psig to 5000 psig), e.g., about 4.8 MPag to about 21 MPag, and a hydrogen treat gas rate of about 36 m³/m³(˜200 scf/B) to about 1800 m³/m³(˜10000 scf/B), e.g., about 180 m³/m³(˜1000 scf/B) to about 900 m³/m³(˜5000 scf/B). In certain embodiments, the conditions can include temperatures in the range of about 600° F. (˜343° C.) to about 815° F. (˜435° C.), hydrogen partial pressures of about 500 psig (˜3.5 MPag) to about 3000 psig (˜21 MPag), and hydrogen treat gas rates of about 210 m³/m³(˜1200 scf/B) to about 1100 m³/m³(˜1200 scf/B). The LHSV can be from about 0.1 hr⁻¹to about 10 hr⁻¹, such as from about 0.5 hr⁻¹to about 5 hr⁻¹and/or from about 1 hr⁻¹to about 4 hr⁻¹.
The methods for organosilicon removal disclosed herein can be used to make improved products with reduced silicon contents. In certain embodiments, the silicon contents of the products can enable them to be exposed to further treatments using certain hydrocarbon conversion catalysts for which organosilicon compounds can be strong poisons or deactivators. While such methods may not completely remove the organosilicon compounds from the feedstreams and/or blended streams, they may advantageously reduce the silicon content low enough for the certain hydrocarbon conversion catalysts to have a reasonable lifetime of activity, even with a relatively low rate of organosilicon poisoning/deactivation. The reduced silicon content products can be further treated to provide end-use compositions for fuels, fuel blendstocks, lubricants, and lubricant blendstocks, among other things.

Definitions

For purposes of this invention and the claims hereto, the numbering scheme for the Periodic Table Groups is according to the IUPAC Periodic Table of Elements.
The term “and/or” as used in a phrase such as “A and/or B” herein is intended to include “A and B,” “A or B,” “A and not B” and “B and not A.”
The terms “substituent,” “radical,” “group,” and “moiety” may be used interchangeably.
As used herein, and unless otherwise specified, the term “C_n” means hydrocarbon(s) having n carbon atom(s) per molecule, wherein n is a positive integer.
As used herein, and unless otherwise specified, the term “hydrocarbon” means a class of compounds containing hydrogen bound to carbon, and encompasses (i) saturated hydrocarbon compounds, (ii) unsaturated hydrocarbon compounds, and (iii) mixtures of hydrocarbon compounds (saturated and/or unsaturated), including mixtures of hydrocarbon compounds having different values of n.
The term “ring atom” means an atom that is part of a cyclic ring structure. By this definition, a benzyl group has six ring atoms and tetrahydrofuran (THF) has 5 ring atoms. As noted by reference to THF, ring atoms need not be only carbon atoms—they can include one or more heteroatoms such as N, O, and/or S. When a cyclic ring structure contains only a singular heteroatom or only one instance each of more than one type of heteroatom, the heteroatom can described by the ring name, even if the cyclic structure has a substituted ring structure. For example, the furanyl oxygen describes the sole oxygen in the THF ring; the piperidinyl nitrogen describes the sole nitrogen in a piperidinyl ring; and the morpholinyl nitrogen and the morpholinyl oxygen describe the sole nitrogen and the sole oxygen, respectively in a morpholinyl ring. However, because of the ambiguity, it would not be proper to characterize either of the two nitrogens in a piperazinyl ring as “the piperazinyl nitrogen.”
For purposes of this invention and claims thereto, unless otherwise indicated, the term “substituted” means that a hydrogen group has been replaced with a heteroatom, or a heteroatom containing group. For example, a “substituted hydrocarbon” is a hydrocarbon made of carbon and hydrogen where at least one carbon (and attendant hydrogen(s)) and/or at least one hydrogen is replaced by a heteroatom or heteroatom containing group.
A heterocyclic ring is a ring having a heteroatom in the ring structure as opposed to a heteroatom substituted ring where a hydrogen on a ring atom is replaced with a heteroatom. For example, tetrahydrofuran is a heterocyclic ring and 4-N,N-dimethylamino-phenyl is a heteroatom substituted ring.
Unless otherwise indicated, where isomers of a named group exist (for alkyl, e.g., n-butyl, iso-butyl, sec-butyl, and tert-butyl) reference to one member of the group (e.g., n-butyl) shall expressly disclose the remaining isomers (e.g., iso-butyl, sec-butyl, and tert-butyl) in the family. Likewise, reference to an isomeric group without specifying a particular isomer (e.g., butyl) expressly discloses all isomers (e.g., n-butyl, iso-butyl, sec-butyl, and tert-butyl).
The term “polymer” is used herein to refer to homopolymers, copolymers, interpolymers, terpolymers, etc. Likewise, a copolymer may refer to a polymer comprising at least two monomers, optionally with other monomers. A “homopolymer” is a polymer having all mer units that are the same. A “copolymer” is a polymer having two or more types of mer units that are distinct or different from each other. A “terpolymer” is a polymer having three types of mer units that are distinct or different from each other. “Distinct” or “different,” as used to refer types of mer units, indicates that the mer units differ from each other by at least one atom or are different isomerically. Accordingly, the definition of copolymer, as used herein, includes terpolymers and the like. When a polymer is referred to as comprising a monomer, the monomer is present in the polymer in the polymerized form of the monomer or in the polymerized form of a derivative from the monomer (i.e., a monomeric unit). However, for ease of reference, the phrase “comprising [the respective] monomer” or the like is used herein as shorthand.
The following abbreviations may be used herein: Me is methyl, Et is ethyl, Pr is propyl, cPr is cyclopropyl, nPr is n-propyl, iPr is isopropyl, Bu is butyl, nBu is normal butyl, iBu is isobutyl, sBu is sec-butyl, tBu is tert-butyl, Oct is octyl, Ph is phenyl, Bz is benzyl, OH (or —OH) is hydroxyl, and RT is room temperature (and is between about 20° C. and about 25° C., unless otherwise indicated).
All priority documents, patents, publications, and patent applications, test procedures (such as ASTM methods), and other documents cited herein are fully incorporated by reference to the extent such disclosure is not inconsistent with this invention and for all jurisdictions in which such incorporation is permitted.
Certain embodiments and features have been described using a set of numerical upper limits and a set of numerical lower limits. It should be appreciated that, within a single characterization, ranges spanning from any lower limit to any upper limit are contemplated unless otherwise indicated. Certain lower limits, upper limits, and ranges appear in one or more claims below. All numerical values are “about” or “approximately” the indicated value, and take into account experimental error and variations that would be expected by a person having ordinary skill in the art.
To the extent a term used in a claim is not defined above, it should be given the broadest definition persons in the pertinent art have given that term as reflected in at least one printed publication or issued patent. Furthermore, all patents, test procedures, and other documents cited in this application are fully incorporated by reference to the extent such disclosure is not inconsistent with this application and for all jurisdictions in which such incorporation is permitted.

Additional Embodiments

The present invention can additionally or alternatively include one or more of the following embodiments.

Embodiment 1

A method of removing organosilicon compounds from a petroleum-based feedstream, the method comprising: providing a petroleum-based feedstream having a first silicon content of at least 1.0 wppm; and filtering the petroleum-based feedstream to yield a permeate having a second silicon content lower than the first silicon content, wherein the second silicon content is at least 25% lower than the first silicon content, the second silicon content is less than 1.0 wppm, or both.

Embodiment 2

The method of embodiment 1, wherein the petroleum-based feedstream comprises a bituminous crude oil, a diluted heavy crude oil, an at least partially deasphalted heavy crude oil, a diluted and at least partially deasphalted heavy crude oil, a fracked crude oil, a tight oil, a bottoms stream from a refinery distillation separator, an off-spec fuel stream, an off-spec lubricant stream, or a combination thereof.

Embodiment 3

The method of embodiment 1 or embodiment 2, wherein the petroleum-based feedstream exhibits one or more enumerated characteristics: a solids content of at least 0.5 wt %; an insolubility number (IN) of at least 10; a solubility blending number (SBN) of 90 or less; a difference between SBN and IN of at least 15; and a silicon content of at least 1.3 wppm.

Embodiment 4

The method of embodiment 3, wherein the petroleum-based feedstream exhibits at least four of the enumerated characteristics.

Embodiment 5

The method of embodiment 1 or embodiment 2, wherein the petroleum-based feedstream exhibits one or more enumerated characteristics: a solids content less than 0.5 wt %; an insolubility number (IN) less than 10; a solubility blending number (SBN) of greater than 90; a difference between SBN and IN of less than 15; and a silicon content of at least 1.5 wppm.

Embodiment 6

The method of embodiment 5, wherein the petroleum-based feedstream exhibits at least three of the enumerated characteristics.

Embodiment 7

The method of any of the preceding embodiments, further comprising adding solids to the petroleum-based feedstream to form a solids-enriched petroleum-based feedstream before the filtering step, which then filters the solids-enriched petroleum-based feedstream.

Embodiment 8

The method of embodiment 7, wherein the added solids comprise silica, alumina, a silicate, an aluminosilicate, sand, a silicon-containing clay, an aluminum-containing clay, hydrocarbon conversion catalyst fines, at least partially spent hydrocarbon conversion catalyst fines, a zeolite, or a combination thereof.

Embodiment 9

The method of embodiment 7 or embodiment 8, wherein the solids-enriched petroleum-based feedstream has a solids content of at least 0.5 wt %, and wherein the permeate from the filtering step additionally exhibits a solids content of 0.2 wt % or less.

Embodiment 10

The method of any of the preceding embodiments, further comprising blending the petroleum-based feedstream with a petroleum-based blendstock to form a petroleum-based blended stream before the filtering step, which then filters the petroleum-based blended stream, wherein the petroleum-based blended stream retains a silicon content of at least 1.3 wppm and exhibits one or more enumerated characteristics: a solids content of at least 0.5 wt %; an insolubility number (IN) of at least 10; a solubility blending number (SBN) of 90 or less; and a difference between SBN and IN of at least 15.

Embodiment 11

The method of embodiment 10, wherein the permeate from the filtering step additionally exhibits a solids content of 0.2 wt % or less.

Embodiment 12

The method of any of the preceding embodiments, wherein the second silicon content is less than 1.0 wppm and at least 50% lower than the first silicon content.

Embodiment 13

The method of any of the preceding embodiments, wherein the filtering step utilizes a porous solid filter made of a material that has substantially no catalytic activity for hydrocarbon conversion and having a pore size of 1 micron or less.

Embodiment 14

The method of embodiment 13, wherein the porous solid filter comprises a polymer with repeat units comprising an amine, an amide, an ester, an ether, an imine, a urethane, a urea, a siloxane, polymerized ethylene, polymerized propylene, a polymerized styrenic, a polymerized diene, a polymerized acrylate, a polymerized acetate, or a combination thereof.

Embodiment 15

The method of any of the preceding embodiments, wherein the filtering step is conducted at a temperature between 0° C. and 225° C., at a pressure between 50 kPaa and 2.2 MPaa, or both.

Embodiment 16

The method of any of the preceding embodiments, wherein the organosilicon compounds accounting for at least 10% of the first silicon content have a high molecular weight corresponding to a viscosity of at least 25000 cPs.

Embodiment 17

The method of embodiment 16, wherein the molecular weight of the organosilicon compounds corresponds to a viscosity between 50000 cPs and 1000000 cPs.

Embodiment 18

The method of any of the preceding embodiments, further comprising a distilling step before the filtering step, wherein the distilling step yields the petroleum-based feedstream as a side draw or as a bottoms stream.

Embodiment 19

The method of any of the preceding embodiments, wherein the permeate is further subject to one or more catalytic hydrocarbon conversion refinery processes to form an unadditized fuel/lubricant product or blendstock selected from the group consisting of motor gasoline, diesel fuel, kerosene, jet fuel, avgas, Group I lubricant, Group II lubricant, Group III lubricant, Group IV lubricant, Group V lubricant, a biofuel, a biolubricant, and combinations thereof.

EXAMPLES

Example 1

Example 1 shows the effect of filtration on a number of crude oil samples containing an undesirably high silicon content, believed to be from the presence of polymeric silicon-containing antifoaming agents used in their production. In this Example, a first aliquot (˜5 mL to ˜100 mL) of each provided sample was analyzed by ICP-AES according to ASTM 5185 to determine silicon content (pre-filtration). Then, each sample was filtered using a ˜0.45-micron nylon filter. From each permeate a second aliquot was taken and analyzed a second time (again by ICP-AES according to ASTM 5185) to determine silicon content (post-filtration). The results are shown below in Table 1, along with pre-filtration characteristics of solubility blending number (SBN) and insolubility number (IN).

	TABLE 1

		Post-
	Pre-filtration	filtration

				Si	Si
				content	content
Sample	Description	SBN	IN	(wppm)	(wppm)

A	Diluted* and upgraded	87	23	~6.3	<1.0**
	bituminous oil sands crude
B	Diluted* and upgraded	87	23	~5.6	<1.0**
	bituminous oil sands crude
C	Diluted* and upgraded	87	23	~5.1	<1.0**
	bituminous oil sands crude
D	Diluted* and upgraded	87	23	~4.5	<1.0**
	bituminous oil sands crude
E	Fracked light shale oil crude	9	0	~2.8	<1.0**
F	Gulf Coast crude	25	0	~3.6	<1.0**
G	Gulf Coast crude	25	0	~1.3	<1.0**

*diluted with ~22-28 vol % of a mixture of a natural gas condensate and a naphtha boiling range diluent.
**below detection limit of ASTM 5185.

As can be seen from the table above, the filtering reduced the Si content for all Samples A-G by at least 23% (Sample G) to at least 84% (Sample A), and possibly up to 100%, depending upon the actual post-filtration Si content, which can be anywhere below 1.0 wppm and down to ˜0 wppm (but which value would have to be measured by a different method, having accuracy below 1.0 wppm).

Example 2

Example 2 shows the effect of solids content in the efficacy of using filtration to remove silicon-containing species from several crude oil samples. In order to test this effect, crude oil sample H1 was pre-filtered using a ˜0.45-micron nylon filter, which, as shown in Example 1, should remove both silicon-containing species and particulate matter larger than the filter. Thereafter, two pre-filtered permeates, H1 and H2, were spiked with a ˜60000 cSt organosilicon polymeric composition (EC9019 A™, commercially available from Nalco), with the aim of attaining approximately 30-40 wppm in the permeate, on a silicon-basis. By spiking the pre-filtered permeates, the efficacy of removing silicon-containing compounds substantially in the absence of solids could be explored. Each first aliquot (˜10 mL to ˜20 mL) of the provided spiked pre-filtered first permeate samples, H1 and H2, were independently analyzed by ICP-AES according to ASTM 5185 to determine silicon content (this is considered a pre-filtration measurement, with respect to the spiked silicon content). Then, the H1 and H2 samples were filtered again using a 0.45-micron nylon filter. From the second permeates of H1 and H2 from the second filtration step (or the first filtration step with a substantially solids-free Si-spiked first H1 permeate), second aliquots were taken and analyzed a second time (again by ICP-AES according to ASTM 5185) to determine silicon content (again, this is considered a post-filtration step with respect to the spiked silicon content). Samples J1 and J2 were treated similarly to samples H1 and H2, with the following exceptions: Samples J1 and J2 were not pre-filtered a first time to remove solids (meaning that solids, and thus any residual silicon-containing compounds, were present during spiking; and samples J1 and J2 were spiked with the organosilicon polymeric composition with the aim of attaining approximately 8-9 wppm on a silicon-basis. Samples K and L were treated similarly to H1 and J1, respectively, with the following exceptions: samples K and L were taken from a different crude source than samples H1 and J1; and sample L was spiked to attain approximately 15 wppm instead of ˜8-9 wppm.
The results are shown below in Table 2, along with characteristics of solubility blending number (SBN) and insolubility number (IN) from each crude oil sample before the pre-spiking filtration step.

	TABLE 2

	Pre-2^nd-	Post-2^nd-
	filtration	filtration

	Pre-1^st-	Si	Si
	filtration	content	content

Sample	Description	SBN	IN	(wppm)	(wppm)

H1	Bituminous oil sands crude	69	21	~43	~36
H2	Bituminous oil sands crude	69	21	~36	~24
J1	Bituminous oil sands crude	69	21	~8.4	~2.8
J2	Bituminous oil sands crude	69	21	~9.0	~1.2
K	Diluted* bituminous oil	85	34	~31	~5.9
	sands crude
L	Diluted* bituminous oil	85	34	~15	~3.2
	sands crude
M	Toluene (control)	100	0	~49	~50

*diluted with ~22-28 vol % of a mixture of a natural gas condensate and a naphtha boiling range diluent.

As can be seen from the table above, sample M shows that removal of organosilicon compounds by filtration can be problematic for compositions with high SBN values, low IN values, and/or low solids contents (spiked toluene contained no intentionally added solids). This observation appears to be corroborated by the relative difficulty observed in organosilicon removal in samples H1, H2, and K, all of which had their solids contents reduced to near 0% by the pre-spiking filtration step, as compared to samples J1, J2, and L in Example 2, as well as to samples A-F in Example 1, all of which did not undergo an initial (pre-spiking) filtration step.
Without being bound by theory, it is believed that some combination of high SBN value, low IN value, small difference between SBN value and IN value, and low solids content (as well as a higher than desired silicon content, of course) can individually or collectively reduce the efficacy of filtration for organosilicon removal and/or for reduction of silicon content to at or below detection level (˜1.0 wppm, per ASTM 5185).
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

1. A method of removing organosilicon compounds from a petroleum-based feedstream, the method comprising:

providing a petroleum-based feedstream having a first silicon content of at least 1.0 wppm; and

filtering the petroleum-based feedstream to yield a permeate having a second silicon content lower than the first silicon content,

wherein the second silicon content is at least 25% lower than the first silicon content, the second silicon content is less than 1.0 wppm, or both.

2. The method of claim 1, wherein the petroleum-based feedstream comprises a bituminous crude oil, a diluted heavy crude oil, an at least partially deasphalted heavy crude oil, a diluted and at least partially deasphalted heavy crude oil, a tracked crude oil, a tight oil, a bottoms stream from a refinery distillation separator, an off-spec fuel stream, an off-spec lubricant stream, or a combination thereof.

3. The method of claim 1, wherein the petroleum-based feedstream exhibits one or more enumerated characteristics: a solids content of at least 0.5 wt %; an insolubility number (IN) of at least 10; a solubility blending number (SBN) of 90 or less; a difference between SBN and IN of at least 15; and a silicon content of at least 1.3 wppm.

4. The method of claim 3, wherein the petroleum-based feedstream exhibits at least four of the enumerated characteristics.

5. The method of claim 1, wherein the petroleum-based feedstream exhibits one or more enumerated characteristics: a solids content less than 0.5 wt %; an insolubility number (IN) less than 10; a solubility blending number (SBN) of greater than 90; a difference between SBN and IN of less than 15; and a silicon content of at least 1.5 wppm.

6. The method of claim 5, wherein the petroleum-based feedstream exhibits at least three of the enumerated characteristics.

7. The method of claim 1, further comprising adding solids to the petroleum-based feedstream to form a solids-enriched petroleum-based feedstream before the filtering step, which then filters the solids-enriched petroleum-based feedstream.

8. The method of claim 7, wherein the added solids comprise silica, alumina, a silicate, an aluminosilicate, sand, a silicon-containing clay, an aluminum-containing clay, hydrocarbon conversion catalyst fines, at least partially spent hydrocarbon conversion catalyst fines, a zeolite, or a combination thereof.

9. The method of claim 7, wherein the solids-enriched petroleum-based feedstream has a solids content of at least 0.5 wt %, and wherein the permeate from the filtering step additionally exhibits a solids content of 0.2 wt % or less.

10. The method of claim 1, further comprising blending the petroleum-based feedstream with a petroleum-based blendstock to form a petroleum-based blended stream before the filtering step,

wherein the petroleum-based blended stream retains a silicon content of at least 1.3 wppm and exhibits one or more enumerated characteristics: a solids content of at least 0.5 wt %; an insolubility number (IN) of at least 10; a solubility blending number (SBN) of 90 or less; and a difference between SBN and IN of at least 15.

11. The method of claim 10, wherein the permeate from the filtering step additionally exhibits a solids content of 0.2 wt % or less.

12. The method of claim 1, wherein the second silicon content is less than 1.0 wppm and at least 50% lower than the first silicon content.

13. The method of claim 1, wherein the filtering step utilizes a porous solid filter made of a material that has substantially no catalytic activity for hydrocarbon conversion and having a pore size of 1 micron or less.

14. The method of claim 13, wherein the porous solid filter comprises a polymer with repeat units comprising an amine, an amide, an ester, an ether, an imine, a urethane, a urea, a siloxane, polymerized ethylene, polymerized propylene, a polymerized styrenic, a polymerized diene, a polymerized acrylate, a polymerized acetate, or a combination thereof.

15. The method of claim 1, wherein the filtering step is conducted at a temperature between 0° C. and 225° C., at a pressure between 50 kPaa and 2.2 MPaa, or both.

16. The method of claim 1, wherein the organosilicon compounds accounting for at least 10% of the first silicon content have a high molecular weight corresponding to a viscosity of at least 25000 cPs.

17. The method of claim 16, wherein the molecular weight of the organosilicon compounds corresponds to a viscosity between 50000 cPs and 1000000 cPs.

18. The method of claim 1, further comprising a distilling step before the filtering step, wherein the distilling step yields the petroleum-based feedstream as a side draw or as a bottoms stream.

19. The method of claim 1, wherein the permeate is further subject to one or more catalytic hydrocarbon conversion refinery processes to form an unadditized fuel/lubricant product or blendstock selected from the group consisting of motor gasoline, diesel fuel, kerosene, jet fuel, avgas, Group I lubricant, Group II lubricant, Group III lubricant, Group IV lubricant, Group V lubricant a biofuel, a biolubricant, and combinations thereof.