ES1322257U - Apparatus for the dehydrogenation of normal paraffins to olefins - Google Patents

Abstract

An apparatus for dehydrogenating normal paraffins to olefins for use in the production of linear alkyl benzenes, comprising: a deoxygenation unit (110) being in communication with a triglyceride line (105); a C9-C14 line (115) and a C14+ line (120), wherein the C9-C14 line (115) and the C14+ line (120) are in communication with the deoxygenation unit (110); a first adsorbent bed containing a first adsorbent comprising alkaline or alkaline earth cation exchange zeolite X, and being in communication with a first line (130); a decontaminated stream line (145) being in communication with the first adsorbent bed; and a dehydrogenation unit (150) that is in communication with the decontaminated stream line (145); a dehydrogenated stream line (155) that is in communication with the dehydrogenation unit (150); (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

Apparatus for the dehydrogenation of normal paraffins to olefins

Background

Linear alkylbenzenes are organic compounds with the formula CeHsCnHan+i. While the number of alkyl carbon atoms, “n,” can have any practical value, detergent manufacturers desire alkylbenzenes with alkyl carbon atom numbers in the range of 9 to 16, and preferably in the range of 9 to 14. These specific ranges are often required when alkylbenzenes are used as intermediate compounds in the production of detergent surfactants. The number of alkyl carbon atoms in the range of 9 to 14 matches the specifications of the detergent industry.

Because surfactants created from alkylbenzenes are biodegradable, alkylbenzene production has grown rapidly since its initial use in detergent production in the 1960s. The linearity of the paraffin chain in alkylbenzenes is key to the material's biodegradability and effectiveness as a detergent. An important factor in the final linearity of alkylbenzenes is the linearity of the paraffin component.

While detergents manufactured using alkylbenzene-based surfactants are biodegradable, previous processes for creating alkylbenzenes do not rely on renewable sources. Specifically, alkylbenzenes are currently produced from kerosene refined from crude oil extracted from the earth. Due to growing environmental prejudice against fossil fuel extraction and economic concerns about the depletion of fossil fuel deposits, there may be support for the use of an alternative source of biodegradable surfactants in detergents and other industries.

C9 to C14 paraffins generated from feedstocks based on vegetable oils or animal fats contain contaminants that can poison dehydrogenation catalysts. These contaminants can also cause discoloration of linear alkylbenzenes and linear alkylbenzenesulfonates. Contaminants can include aromatic compounds, light oxygenates, fatty acids, fatty esters, and the like. These contaminants must be removed before dehydrogenating C9 to C14 paraffins.

Therefore, it is desirable to provide the dehydrogenation unit with decontaminated C9 to C14 paraffins from easily processed renewable triglycerides and fatty acids from vegetable, animal, nut, and/or seed oils. Palm kernel oil, coconut oil, and babassu oil have a high composition in the desirable range of C9-C14 n-paraffins, which aligns with the alkyl carbon number range desired by the detergent industry. Such renewable sources also have a high amount of nC16 to nC18 feedstocks, and it is desirable to convert those feedstocks to nC9 to nC14 feedstocks in a high yield per pass. These nC9 to nC14 intermediates are useful for ultimately manufacturing linear alkylbenzene-type detergents via additional process steps. It is further desirable that the resulting nC9 to nC14 paraffins be linear products with a minimum of branched isomeric products.

Brief description of the drawings

Fig. 1 is a schematic view of an embodiment of a process for producing alkylbenzenes from triglycerides according to the present invention.

Fig. 2 is a graphical representation of the mass % of normal paraffins versus the deoxygenation temperature according to Example 2.

Detailed description

The present invention relates to an apparatus for the dehydrogenation of normal paraffins to olefins for use in the production of linear alkylbenzenes. The present invention further relates to a decontaminated paraffin stream. The decontaminated paraffin stream can be obtained from the apparatus defined herein. Also provided is a process for the dehydrogenation of normal paraffins to olefins. The paraffins are derived from renewable feedstocks comprising natural oils, such as vegetable oils, animal fats, nut and/or seed oils, and oils containing triglycerides. The process for purifying the renewable bioparaffin stream involves passing the stream through one or more adsorbent beds comprising adsorbents.

The apparatus of the present invention can be used for the dehydrogenation process of normal paraffins to olefins described herein.

Natural oils are not based on kerosene or other fossil fuels. Natural oils include those derived from plant or algal materials or animal fats, nut and/or seed oils, and oils containing triglycerides, and are often referred to as renewable oils. Natural oils typically comprise triglycerides, free fatty acids, or combinations thereof. Natural oils include, but are not limited to, Arachis oil (peanut oil), babassu oil, coconut oil, cottonseed oil, grapeseed oil, corn oil, mustard seed oil, palm kernel oil, palm oil, palm olein (the liquid fraction derived from the fractionation of palm oil), palm stearin (the high melting fraction derived from the fractionation of palm oil), rapeseed oil, rapeseed oil - low erucic acid (low erucic acid rapeseed oil; low erucic acid rapeseed oil; canola oil), safflower oil (kurdee oil), high oleic safflower seed oil (high oleic safflower oil; high oleic kurdee oil), sesame seed oil (sesame oil; Benne oil; Ben oil; sesame oil), soybean oil, sunflower seed oil (sunflower oil) and high oleic sunflower seed oil (high oleic sunflower oil).

The feed stream derived from natural oils comprises normal paraffins, isoparaffins, olefins, oxygenated compounds and up to 10% by weight of aromatic compounds.

Feed stream contaminants may include oxygenates and/or aromatic compounds and/or fatty acids and esters. To remove at least a portion of the oxygenates, aromatic compounds, and fatty acids and esters from the natural oil-derived paraffin stream, alkaline or alkaline earth cation exchange zeolite X may be used. Suitable adsorbents for removing oxygenates and aromatic compounds include, but are not limited to, alkaline or alkaline earth cation exchange zeolite X.

After contaminant removal, the treated stream comprises no more than 6000 ppm of aromatic compounds and no more than 100 ppm of oxygenated compounds.

A second adsorbent bed can optionally be included to further reduce the concentration of oxygenated compounds, aromatic compounds, and fatty acids and esters in the treated stream. The second adsorbent includes, among others, zeolite 5A.

The first and/or second adsorbent bed may be regenerated at a predetermined time to remove at least a portion of the oxygenated compounds, or the aromatic compounds, or both adsorbed on the first and/or second adsorbent.

There may be one or more first adsorbent beds and one or more second adsorbent beds.

The paraffin stream from renewable feedstocks comprising vegetable oils and animal fats may also contain other contaminants, such as sulfur compounds, nitrogen compounds, phosphorus compounds, or combinations thereof. These contaminants can be removed by passing the treated stream through a third adsorbent bed containing a third adsorbent. The third adsorbent may include, among others, zeolite 13X, zeolite 5A, an alumina-zeolite, or combinations thereof.

After the feed stream derived from natural oils has passed through the first adsorbent bed, and optionally the second and/or third adsorbent beds, the treated stream is dehydrogenated to convert at least a portion of the paraffins in the treated stream into olefins. The dehydrogenated stream comprises monoolefins, diolefins, and aromatic compounds.

The contaminant removal process may be incorporated into a process for manufacturing alkylbenzenes from natural oils. The process involves deoxygenating the natural oils to form paraffins. The paraffins are separated (by fractionation or distillation, and the like) into a C9 to C14 stream comprising C9 to C14 paraffins and a C14+ stream comprising C14+ paraffins. The C14+ stream is sent to a separate linear selective cracking unit to crack the C14+ paraffins; the cracked paraffins are fractionated into a first stream comprising the C9 to C14 normal and lightly branched paraffins and a second stream comprising isoparaffins. Contaminants, including, but not limited to, oxygenated compounds and/or aromatic compounds and/or fatty acids and esters, and/or sulfur compounds, and/or nitrogen compounds, and/or phosphorus compounds, or combinations thereof, are removed from the C9 to C14 stream and the first stream. The decontaminated stream is dehydrogenated to form olefins, diolefins, and aromatic compounds. The diolefins are selectively hydrogenated to form additional olefins, and the aromatic compounds are separated and removed forming an aromatics stream comprising the aromatics and a monoolefins stream comprising the monoolefins. Benzene is alkylated with the olefins, and the alkylation effluent comprises alkylbenzenes and benzene. The alkylbenzenes are then isolated.

To limit catalyst deactivation, the feedstock is treated to remove sulfur contamination prior to hydrodeoxygenation. Otherwise, sulfur accumulates on the catalyst and causes its deactivation. It has been shown that high-temperature hydrogen treatment recovers some of the lost activity. The degree of hydrodeoxygenation can affect the selectivity toward each of the normal paraffins in the range of 9 to 14 carbon atoms. A high degree of hydrodeoxygenation can bias the hydrodeoxygenated composition heavily in favor of normal dodecane and normal decane to the detriment of normal undecane and normal tridecane. A low degree of hydrodeoxygenation can bias the hydrodeoxygenated composition in favor of normal undecane and normal tridecane to the detriment of normal dodecane and normal decane.

Hydrodeoxygenation reactor temperatures are kept low, less than 343°C (650°F) for typical biorenewable feedstocks and less than 304°C (580°F) for feedstocks with higher free fatty acid (FFA) concentrations, to prevent polymerization of the olefins found in FFAs. Typically, a hydrodeoxygenation reactor pressure of 700 kPa (100 psig) to 21 MPa (3000 psig) is adequate.

The linearity of the alkylbenzene-type product depends primarily on the linearity of the paraffins used to alkylate the benzene. It is a common rule of thumb among those skilled in the art that the linearity of a paraffin feed drops between 5 and 7 mass % after dehydrogenation and alkylation. Therefore, a paraffin with a linearity of 97 mass % (or alternatively 3 mass % isoparaffin) would result in an alkylbenzene-type product with a linearity of about 90-92 mass %. This sets the linearity requirement for paraffins between 5 and 7 mass % higher than the specification for the alkylbenzene-type product. Typically, the linearity of the paraffin-type product is measured by standard test methods UOP 621, UOP 411, or UOP 732 available from ASTM, which are incorporated herein by reference in their entirety. Linear alkylbenzenes can be analyzed using the test method of ASTM D4337, incorporated herein by reference in its entirety.

An exemplary system 100 for producing an alkylbenzene-type product from a specific triglyceride feed is illustrated in Figure 1.

In the illustrated embodiment, the selected triglyceride feed 105 is supplied to a deoxygenation unit 110 which also receives a hydrogen feed (not shown). In the deoxygenation unit 110, the fatty acids in the triglyceride feed 105 are deoxygenated and converted into normal paraffins. Structurally, triglycerides are made up of three, typically different, fatty acid molecules that are linked by a glycerol bridge. The glycerol molecule includes three hydroxyl groups (HO-) and each fatty acid molecule has one carboxyl group (COOH). In triglycerides, the hydroxyl groups of glycerol are linked to the carboxyl groups of the fatty acids to form ester bonds. Therefore, during deoxygenation, the fatty acids are released from the triglyceride structure and converted into normal paraffins. Glycerol is converted into propane, and the oxygen from the hydroxyl and carboxyl groups is converted into water, carbon dioxide, or carbon monoxide. The deoxygenation reactions of fatty acids and triglycerides are illustrated, respectively, as follows:

During the deoxygenation reaction, the length of a paraffin chain Rn created will vary by one depending on the exact reaction pathway. Deoxygenation is understood to include at least one of hydrodeoxygenation, decarboxylation, and decarbonylation, or any combination thereof. For example, if carbon dioxide is formed, then the chain will have one atom less than the fatty acid source. If water is formed, then the chain will match the length of the fatty acid source.

Operating conditions for the deoxygenation unit include pressures in the range of 1724 to 5516 kPa (250 to 800 psig) and temperatures in the range of 274°C to 371°C (525°F to 700°F) in one embodiment, 274°C to 338°C (525°F to 640°F) in another embodiment, and 274°C to 310°C (525°F to 590°F) in another embodiment. Catalysts may include those containing one or more of Ni, Mo, Co, P, such as Ni-Mo, Ni-Mo-P, Ni-Co-Mo, or Co-Mo, on aluminas, silica, titania, zirconia, and mixtures thereof. Suitable hydrogen to hydrocarbon molar ratios include 267.2 to 1781.1 normal m3 per m3 of feedstock (Nm3/m3) (1500 to 10,000 normal cubic feet per barrel of feedstock (scf/B)), 712.4 to 1603 Nm3/m3 of feedstock (4,000 to 9,000 scf/B), and 890.4 to 1424.9 Nm3/m3 of feedstock (5,000 to 8,000 scf/B). Suitable space velocities include LHSVs of 0.2 to 3.0 h-1. Conditions are selected to minimize cracking or isomerization of the paraffins.

The deoxygenated product contains normal paraffins, water, carbon dioxide, carbon monoxide, and propane, and the propane is fractionated into a C9 to C14 stream 115 and a C14+ stream 120. The separation can be performed in a multistage fractionation unit, a distillation system, or similar known apparatus. In either case, the separator removes water, carbon dioxide, carbon monoxide, and propane from the deoxygenated product. A paraffin naphtha stream with carbon atom chain lengths from C5 to C9 (not shown) can also be formed.

C14+ stream 120 is sent to linear selective cracking unit 125 where it is selectively cracked to form a first stream 130 comprising normal or lightly branched C9 to C14 paraffins and a second stream 135 comprising isoparaffins. The linear selective cracking takes place in a separate unit, rather than in the lower bed of a first stage in a hydrocracking reactor because sulfur and nitrogen contaminants from the first stage can poison the metal-based hydrocracking catalyst. C14+ paraffins are selectively cracked relative to C9 to C14 paraffins due to higher adsorption energy.

The selection of specific metal catalysts, including noble metals (such as ruthenium and platinum) and nickel, can produce much higher yields of normal paraffins with 9–14 carbon atoms than previous processes. Suitable catalysts include, but are not limited to, Ru/ZrO2, Pt-Al2O3, Ni-alumina, or NiOx/clay. With these catalysts, the C14+ stream is capable of generating linear cracking products without significant production of branched isomers.

Of the preferred catalysts, the Ru catalyst shows much higher activity and yield per step from nC9 to nC14 than the other catalysts. Under the optimized reaction conditions, it also produces very small amounts of methane and isomerized product. This has been found to be the best catalyst for such a chemical transformation process. The Pt-Al2O3 catalyst can produce an even lower methane yield than the Ru-based catalyst, with a slightly lower yield of linear product.

The C9 to C14 stream 115 from the deoxygenation unit 110 and the first stream 130 from the linear selective cracking unit 125 are sent to a decontamination unit 140 described above. The decontamination unit 140 separates contaminants from the C9 to C14 paraffins in the C9 to C14 stream 115 and in the first stream 130. Contaminants include, but are not limited to, oxygenated and/or aromatic compounds, and/or phosphorus compounds, or combinations thereof.

The decontaminated stream 145 is sent to a dehydrogenation unit 150 where hydrogen is removed to produce a dehydrogenated stream 155 comprising monoolefins, diolefins, and aromatic compounds. In the dehydrogenation unit 150, the paraffins are dehydrogenated into monoolefins with the same number of carbon atoms as the paraffins. Typically, dehydrogenation occurs by known catalytic processes, such as the commercially popular Pacol process. Diolefins (i.e., dienes) and aromatic compounds are also produced as unwanted results of the dehydrogenation reactions, as expressed in the following equations:

Operating conditions for dehydrogenation unit 150 include LHSV space velocities of 5 to 50 and LHSV of 20 to 32; pressures of 34 kPa(g) to 345 kPa(g) (5 psig to 50 psig) and 103 kPa(g) to 172 kPa(g) (15 psig to 25 psig); temperatures of 400°C to 500°C and 440°C to 490°C; and hydrogen to hydrocarbon mole ratios of 1-12 and 3-7. An example of a suitable catalyst is a Pt-on-alumina catalyst in which the platinum is attenuated with an attenuating metal. Another suitable catalyst is described in U.S. Patent No. 6,177,381, incorporated herein by reference in its entirety. Dehydrogenation unit 150 can operate dry or with water injection up to 2000 ppm by mass of water. The hydrogen can be recycled to the upstream deoxygenation unit.

The dehydrogenated stream 155 is sent to a selective hydrogenation unit 160, such as a DeFine reactor, where at least a portion of the diolefins are hydrogenated to form additional monoolefins. As a result, the monoolefin stream 170 has an increased concentration of monoolefins compared to the dehydrogenated stream 155. Aromatics are separated and removed as the aromatics stream 165. If needed, a final lights stream 167 containing any lights, such as butane, propane, ethane, and methane, that are derived from cracking or other reactions during upstream processing may also be separated.

Monoolefin stream 170 comprising monoolefins is sent to alkylation unit 175 along with a benzene stream 180. The benzene is alkylated with the monoolefins to form alkylbenzenes. Alkylation unit 175 contains a catalyst, such as a solid acid catalyst, that supports the alkylation of benzene with the monoolefins. Fluorinated silica-alumina, hydrogen fluoride (HF), aluminum chloride (AlCh), zeolitic, and ionic liquid catalysts are examples of major commercially used catalysts for the alkylation of benzene with linear monoolefins and may be used in alkylation unit 175. As a result of the alkylation, alkylbenzenes, typically called linear alkylbenzenes (LAB), are formed according to the reaction:

Suitable operating conditions for alkylation unit 175 include LHSV space velocities of 1 to 10 h-1, pressures to maintain liquid-phase operation, such as 2068 kPa(g) to 4137 kPa(g) (300 psig to 600 psig), temperatures ranging from 80°C to 180°C and 120°C to 170°C, and benzene-to-olefin mole ratios of 3 to 40 and 8 to 35.

To achieve the desired high degree of alkylation, excess amounts of benzene are supplied to the alkylation unit 175. Therefore, the alkylation effluent 185 exiting the alkylation unit 175 contains alkylbenzenes and unreacted benzene. In addition, the alkylation effluent 185 may also include some unreacted paraffins. The alkylation effluent 185 is passed to a benzene separation unit 190, such as a fractionating column, to separate the benzene and unreacted paraffins from the alkylation effluent 185. The unreacted benzene exits the benzene separation unit 190 in a benzene recycle stream 195 that may be sent back to the alkylation unit 175 to maintain the desired benzene/olefin ratio (e.g., 1:50) and to reduce the volume of fresh benzene required. The fresh benzene requirement (i.e., net benzene) is determined by the net olefin feed to the alkylation unit. A paraffin stream 200 can also be separated and recycled to the dehydrogenation unit 150.

As a result of the post-alkylation separation processes, the linear alkylbenzene-type product 205 is isolated. It should be noted that such separation processes are not necessary in all embodiments to isolate the linear alkylbenzene-type product 205.

Linear alkylbenzene-type product 205 is a linear alkylbenzene-type product comprising: alkylbenzenes having the formula CeHsCnHan+i wherein n is from 9 to 14. In some embodiments, at least 80% by mass of the alkylbenzenes have linear alkyl groups, or at least 90% by mass.

Linear alkylbenzene can be sulfonated to provide a linear alkylbenzenesulfonate product comprising: alkylbenzenesulfonate compounds having the formula CnH<2>n+<1>CeH<4>SO<3>H wherein n is from 10 to 14, or wherein n is from 11 to 13.

The term "column" means a distillation column or columns for separating one or more components of different volatilities. Unless otherwise indicated, each column includes a condenser at the top of the column for condensing and refluxing a portion of an overhead stream back to the top of the column and a reboiler at the bottom of the column for vaporizing and sending a portion of the bottom stream back to the bottom of the column. Feeds to the columns may be preheated. The pressure at the top is the overhead vapor pressure at the vapor outlet of the column. The bottom temperature is the bottom liquid outlet temperature. Unless otherwise indicated, overhead and tail piping refer to the net piping from the column downstream of any reflux or vapor taps exiting the reboiler to the column. Stripping columns may omit a reboiler at the bottom of the column and instead provide heating and stripping drive requirements from an inert fluidized medium such as water vapor.

As used herein, the term "a component-rich stream" or "a component-rich stream" means that the stream exiting a vessel has a higher concentration of the component than the feed to the vessel. As used herein, the term "a component-lean stream" means that the lean stream exiting a vessel has a lower concentration of the component than the feed to the vessel.

In a first aspect, the present invention provides apparatus for dehydrogenating normal paraffins to olefins, for use in the production of linear alkylbenzenes, comprising: a deoxygenation unit (110) in communication with a triglyceride line (105); a C9-C14 stream in a C9-C14 line (115) and a C14+ stream in a C14+ line (120), wherein the C9-C14 stream line (115) and the C14+ stream line (120) are in communication with the deoxygenation unit (110); a first adsorbent bed, containing a first adsorbent comprising alkali or alkaline earth cation exchange zeolite X, in communication with a first line (130); a decontaminated stream in a decontaminated stream line (145) in communication with the first adsorbent bed; and a dehydrogenation unit (150) in communication with the decontaminated stream line (145); a dehydrogenated stream in a dehydrogenated stream line (155) in communication with the dehydrogenation unit (150).

In one embodiment, the apparatus further comprises a selective hydrogenation unit (160) in communication with the dehydrogenated stream line (155); and a monoolefin stream in a monoolefin line (170) in communication with the selective hydrogenation unit (160).

In one embodiment, the apparatus further comprises an alkylation unit (175) in communication with the monoolefin line (170); and an alkylation effluent in an alkylation effluent line (185) in communication with the alkylation unit (175), wherein the alkylation effluent in the alkylation effluent line (185) comprises alkylbenzenes and unreacted benzene.

In one embodiment, the apparatus further comprises a benzene separation unit (190) in communication with the alkylation effluent line (185); a linear alkylbenzene product in a linear alkylbenzene product line (205); and a benzene recycle stream in a benzene recycle line (195); wherein the linear alkylbenzene product line (205) and the benzene recycle line (195) are in communication with the benzene separation unit (190).

In one embodiment, the apparatus further comprises a linear selective cracking unit (125) in communication with the C14+ line (120); a first stream in the first line (130) in communication with the linear selective cracking unit (125), and a second stream in a second line (135), wherein the first line (130) and the second line (135) are in communication with the linear selective cracking unit (125).

In one embodiment, the first stream in the first line (130) comprises normal or slightly branched C9-C14 paraffins and the second stream in the second line (135) comprises isoparaffins.

In one embodiment, the apparatus further comprises an optional second adsorbent bed containing a second adsorbent comprising zeolite 5A.

In one embodiment, the apparatus further comprises an optional third adsorbent bed containing a third adsorbent comprising zeolite 13X, zeolite 5A, an alumina-zeolite, or combinations thereof.

In one embodiment, the apparatus further comprises regenerating the adsorbent bed at a predetermined time to remove at least a portion of the oxygenated compounds, or the aromatic compounds, or both adsorbed on the adsorbent.

In another aspect, the present invention provides a decontaminated paraffin stream obtainable from the decontaminated paraffin stream line (145) as defined herein, for use in the production process of linear alkylbenzenes. The decontaminated paraffin stream comprises no more than 6,000 ppm of the aromatic compounds and no more than 100 ppm of the oxygenated compounds.

In one embodiment, the decontaminated paraffin stream further comprises C9 to C14 paraffins.

In one embodiment, the decontaminated paraffin stream further comprises at least 97% by mass linearity.

In one embodiment, the decontaminated paraffin stream is for use in a linear alkylbenzene production process, the process comprising: deoxygenating a triglyceride (105) from a C9 to C14 stream (115) comprising C9-C14 paraffins and a C14+ stream (120) comprising C14+ paraffins; removing contaminants from the C9-C14 stream (115) and a first stream (130) to form a decontaminated stream (145) wherein the contaminants comprise sulfur compounds, or nitrogen compounds, or phosphorus compounds, or oxygenated compounds, or aromatic compounds or combinations thereof; dehydrogenating the dehydrogenated stream (145) to provide a dehydrogenated stream (155) comprising monoolefins, diolefins, and aromatic compounds; selectively hydrogenating diolefins in the dehydrogenated stream (155) to form additional monoolefins, and separating and removing aromatics from the monoolefins to form an aromatics stream (165) comprising the aromatics and a stream (170) comprising the monoolefins; alkylating benzene (180) with the monoolefins under alkylation conditions to provide an alkylation effluent (185) comprising alkylbenzenes and benzene; and isolating the alkylbenzenes to provide the alkylbenzene-type product (205) derived from the triglyceride.

In one embodiment, the decontaminated paraffin stream is produced by passing the first stream (130) through a first adsorbent bed containing a first adsorbent comprising alkaline or alkaline earth cation exchange zeolite X wherein the adsorbent removes at least a portion of the oxygenated compounds and aromatic compounds from the first stream.

In one embodiment, the decontaminated paraffin stream is produced by linear selective cracking of the C14+ stream (120) in a separate linear selective cracking unit (125), under linear selective cracking conditions in the presence of a linear selective cracking catalyst to form the first stream (130) comprising normal or lightly branched C9-C14 paraffins and a second stream (130) comprising isoparaffins.

In another aspect, the present invention provides a decontaminated paraffin stream for use in a linear alkylbenzene production process. The decontaminated paraffin stream comprises no more than 6,000 ppm of the aromatic compounds and no more than 100 ppm of the oxygenated compounds.

In one embodiment, the decontaminated paraffin stream further comprises C9 to C14 paraffins.

In one embodiment, the decontaminated paraffin stream further comprises at least 97% by mass linearity.

In one embodiment, the decontaminated paraffin stream is for use in a linear alkylbenzene production process, which process comprises deoxygenating a triglyceride (105) from a C9 to C14 stream (115) comprising C9-C14 paraffins and a C14+ stream (120) comprising C14+ paraffins; removing contaminants from the C9-C14 stream (115) and a first stream (130) to form a decontaminated stream (145) wherein the contaminants comprise sulfur compounds, or nitrogen compounds, or phosphorus compounds, or oxygenated compounds, or aromatic compounds or combinations thereof; dehydrogenating the dehydrogenated stream (145) to provide a dehydrogenated stream (155) comprising monoolefins, diolefins, and aromatic compounds; selectively hydrogenating the diolefins in the dehydrogenated stream (155) to form additional monoolefins, and separating and removing the aromatics from the monoolefins to form an aromatics stream (165) comprising the aromatics and a monoolefins stream (170) comprising the monoolefins; alkylating the benzene (180) with the monoolefins under alkylation conditions to provide an alkylation effluent (185) comprising alkylbenzenes and benzene; and isolating the alkylbenzenes to provide the alkylbenzene-type product (295) derived from the triglyceride.

In one embodiment, the decontaminated paraffin stream is produced by passing the first stream (130) through a first adsorbent bed containing a first adsorbent comprising alkaline or alkaline earth cation exchange zeolite X, wherein the adsorbent removes at least a portion of the oxygenated compounds and aromatic compounds from the first stream.

In one embodiment, the decontaminated paraffin stream is produced by linear selective cracking of the C14+ stream (120) in a separate linear selective cracking unit (125), under linear selective cracking conditions in the presence of a linear selective cracking catalyst to form the first stream (130) comprising normal or lightly branched C9-C14 paraffins and a second stream (130) comprising isoparaffins.

It will be understood that any embodiment disclosed herein may be combined with any other embodiment disclosed herein.

Examples

Example 1

A coconut oil feed was deoxygenated to form paraffins, dehydrogenated to form monoolefins, and benzene was alkylated with the monoolefins to form an alkylbenzene-type product with a modern carbon content of 62.96 mass % as determined by ASTM D6866, compared to a theoretical modern carbon content of 66.4 mass %, a bromine index of 1 g Br per gram of sample as determined by UOP Standard Test Method 304, and a linearity of 92 mass %.

Example 2

An oil was deoxygenated using a catalyst at a pressure of 3360 kPa (480 psig), H to bio-oil ratio of 1282.4 Nm3/m3 (7200 scf/B), and an LHSV of 1 h-1. During operation, the deoxygenation reaction temperature was increased in steps from 315 °C (600 °F) to 349 °C (660 °F) and then to 377 °C (710 °F) and 404 °C (760 °F) to monitor the response of the final product linearity to the reaction temperature. The results are shown in Fig. 2, which is a graphical representation of the mass % concentration of C10-C13 normal paraffins versus the reaction temperature. Fig. 2 clearly demonstrates that as the deoxygenation reaction temperature increases, the concentration of linear paraffins decreases. Controlling the temperature below 404°C (760°F) resulted in greater than 92 mass percent linear paraffins.

Note: Examples 1 and 2 were previously included in U.S. Patent No. 9,079,814 as Examples 3 and 4.

Specific achievements

While the following is described in conjunction with specific embodiments, it will be understood that this description is intended to illustrate and not limit the scope of the foregoing description and the appended claims.

A first embodiment described herein is a method for dehydrogenating normal paraffins to olefins comprising passing a feed stream derived from natural oils comprising C9 to C14 normal paraffins, isoparaffins, olefins, oxygenates, and up to 10% by weight of aromatics through a first adsorbent bed containing a first adsorbent comprising alkali or alkaline earth cation exchange zeolite X wherein the adsorbent removes at least a portion of the oxygenates and aromatics from the paraffin stream by adsorption to form a treated stream; and dehydrogenating the treated stream to convert at least a portion of the treated stream to olefins and provide a dehydrogenated stream comprising monoolefins, diolefins, and aromatics. An embodiment described herein is any one, any one, or all of the preceding embodiments in this paragraph up to the first embodiment in this paragraph further comprising regenerating the adsorbent bed at a predetermined time to remove at least a portion of the oxygenates, or the aromatic compounds, or both adsorbed on the adsorbent. An embodiment described herein is any one, any one, or all of the preceding embodiments in this paragraph up to the first embodiment in this paragraph further comprising passing the treated stream through a second adsorbent bed containing a second adsorbent comprising zeolite 5A to remove additional oxygenates and aromatics to form a second treated stream. An embodiment described herein is any one, any one, or all of the preceding embodiments in this paragraph up to the first embodiment in this paragraph further comprising regenerating the second adsorbent bed at a predetermined time to remove at least a portion of the oxygenates or the aromatic compounds, or both adsorbed on the second adsorbent. An embodiment described herein is one, any or all of the preceding embodiments in this paragraph up to the first embodiment in this paragraph wherein the feed stream is formed by deoxygenating a natural oil to form a paraffin stream comprising C9 to C28 paraffins; linear selective cracking the paraffin stream in a linear selective cracking unit under linear selective cracking conditions in the presence of a linear selective cracking catalyst to form a first stream comprising normal or lightly branched C9 to C14 paraffins and a second stream comprising isoparaffins. An embodiment described herein is one, any, or all of the preceding embodiments in this paragraph up to the first embodiment in this paragraph further comprising removing contaminants from the treated stream in a third adsorbent bed comprising a third adsorbent to form a decontaminated stream wherein the contaminants comprise sulfur compounds, or nitrogen compounds, or phosphorus compounds, or combinations thereof, wherein the third adsorbent comprises zeolite 13X, zeolite 5A, an alumina-zeolite, or combinations thereof prior to dehydrogenating the treated stream. An embodiment described herein is one, any, or all of the preceding embodiments in this paragraph up to the first embodiment in this paragraph further comprising selectively hydrogenating diolefins in the dehydrogenated stream to form additional monoolefins, and separating and removing aromatics from the monoolefins to form an aromatics stream comprising the aromatics and a monoolefins stream comprising the monoolefins; alkylating the benzene with the monoolefins under alkylation conditions to provide an alkylation effluent comprising alkylbenzenes and benzene; and isolating the alkylbenzenes to provide the alkylbenzene product derived from the natural oil. An embodiment described herein is one, any, or all of the preceding embodiments in this paragraph up to the first embodiment in this paragraph wherein the treated stream comprises no more than 6000 ppm of the aromatic compounds and no more than 100 ppm of the oxygenated compounds.

A second embodiment described herein is a method for the dehydrogenation of normal paraffins to olefins comprising passing a feed stream comprising normal paraffins, isoparaffins, olefins, up to 10% by weight of aromatics and oxygenates through an adsorbent bed containing an adsorbent comprising alkali or alkaline earth cation exchange zeolite X wherein the adsorbent removes at least a portion of the oxygenates and aromatics from the paraffin stream by adsorption to form a treated stream; removing contaminants from the treated stream in a third adsorbent bed comprising a third adsorbent to form a decontaminated stream wherein the contaminants comprise sulfur compounds, or nitrogen compounds, or phosphorus compounds, or combinations thereof, wherein the adsorbent comprises zeolite 13X, zeolite 5A, an alumina-zeolite, or combinations thereof; and dehydrogenating the decontaminated stream to convert at least a portion of the decontaminated stream to olefins and provide a dehydrogenated stream comprising monoolefins, diolefins, and aromatic compounds; regenerating the adsorbent bed at a predetermined time to remove at least a portion of the oxygenates, or the aromatic compounds, or both adsorbed on the adsorbent. An embodiment described herein is any one, or all of the preceding embodiments in this paragraph through the second embodiment in this paragraph further comprising passing the treated stream through a second adsorbent bed containing a second adsorbent comprising zeolite 5A to remove additional oxygenates and aromatics to form a second treated stream prior to removing contaminants in the third adsorbent bed. An embodiment described herein is any one or all of the preceding embodiments in this paragraph through the second embodiment in this paragraph further comprising regenerating the second adsorbent bed at a predetermined time to remove at least a portion of the oxygenates and/or aromatic compounds adsorbed on the second adsorbent. An embodiment described herein is any one or all of the preceding embodiments in this paragraph through the second embodiment in this paragraph wherein the feed stream is formed by deoxygenating a natural oil to form a paraffin stream comprising C9 to C28 paraffins; linear selective cracking the paraffin stream in a linear selective cracking unit under linear selective cracking conditions in the presence of a linear selective cracking catalyst to form a first stream comprising C9 to C14 normal or lightly branched paraffins and a second stream comprising isoparaffins. An embodiment described herein is one, any, or all of the preceding embodiments in this paragraph through the second embodiment in this paragraph further comprising selectively hydrogenating diolefins in the dehydrogenated stream to form additional monoolefins, and separating and removing aromatics from the monoolefins to form an aromatics stream comprising the aromatics and a monoolefins stream comprising the monoolefins; alkylating benzene with the monoolefins under alkylation conditions to provide an alkylation effluent comprising alkylbenzenes and benzene; isolating the alkylbenzenes to provide the alkylbenzene-type product derived from natural oil. An embodiment described herein is one, any, or all of the preceding embodiments in this paragraph through the second embodiment in this paragraph wherein the treated stream comprises no more than 6000 ppm of the aromatics and no more than 100 ppm of the oxygenates.

A third embodiment described herein is a method for the dehydrogenation of normal paraffins to olefins comprising deoxygenating a natural oil to form a paraffin stream comprising C9 to C28 paraffins; linear selective cracking the paraffin stream in a linear selective cracking unit under linear selective cracking conditions in the presence of a linear selective cracking catalyst to form a first stream comprising normal or lightly branched C9 to C14 paraffins and a second stream comprising isoparaffins; passing the first stream, comprising normal paraffins, isoparaffins, olefins, oxygenates and up to 10% by weight of aromatic compounds, through a first adsorbent bed containing a first adsorbent comprising alkali or alkaline earth cation exchange zeolite X wherein the adsorbent removes at least a portion of the oxygenates and aromatic compounds from the first stream by adsorption to form a treated stream; removing contaminants from the treated stream in a third adsorbent bed prior to dehydrogenating the treated stream, the third adsorbent bed comprising a third adsorbent to form a decontaminated stream wherein the contaminants comprise sulfur compounds, or nitrogen compounds, or phosphorus compounds, or combinations thereof, wherein the third adsorbent comprises zeolite 13X, zeolite 5A, an alumina-zeolite or combinations thereof; dehydrogenating the decontaminated stream to convert at least a portion of the decontaminated stream to olefins and providing a dehydrogenated stream comprising monoolefins, diolefins, and aromatics; selectively hydrogenating the diolefins in the dehydrogenated stream to form additional monoolefins, and separating and removing the aromatics from the monoolefins to form an aromatics stream comprising the aromatics and a monoolefins stream comprising the monoolefins; alkylating the benzene with the monoolefins under alkylation conditions to provide an alkylation effluent comprising alkylbenzenes and benzene; and isolating the alkylbenzenes to provide the alkylbenzene-type product derived from the natural oil. An embodiment described herein is any one, any one, or all of the preceding embodiments in this paragraph through the third embodiment in this paragraph further comprising regenerating the first adsorbent bed at a predetermined time to remove at least a portion of the oxygenates, or the aromatic compounds, or both adsorbed on the first adsorbent. An embodiment described herein is any one, any one, or all of the preceding embodiments in this paragraph through the third embodiment in this paragraph further comprising passing the treated stream through a second adsorbent bed containing a second adsorbent comprising zeolite 5A to remove additional oxygenates and aromatics to form a second treated stream. An embodiment described herein is any one, any one, or all of the preceding embodiments in this paragraph through the third embodiment in this paragraph further comprising regenerating the second adsorbent bed at a predetermined time to remove at least a portion of the oxygenates, or the aromatic compounds, or both adsorbed on the second adsorbent. An embodiment described herein is one, any or all of the preceding embodiments in this paragraph through the third embodiment in this paragraph wherein the treated stream comprises no more than 6000 ppm of the aromatic compounds and no more than 100 ppm of the oxygenated compounds.

Without further elaboration, it is believed that, by utilizing the foregoing description, one skilled in the art can utilize the present invention to its fullest extent and readily ascertain the essential features of this invention, without departing from the spirit and scope thereof, to make various changes and modifications of the invention and adapt it to various uses and conditions. Therefore, the foregoing specific preferred embodiments are to be construed as merely illustrative and not limiting the remainder of the disclosure in any way, and are intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

In the above, all temperatures are stated in degrees Celsius and all parts and percentages are by weight, unless otherwise indicated.

Claims (7)

1. An apparatus for dehydrogenating normal paraffins to olefins for use in the production of linear alkylbenzenes, comprising: a deoxygenation unit (110) that is in communication with a triglyceride pipeline (105); a C9-C14 pipe (115) and a C14+ pipe (120), wherein the C9-C14 pipe (115) and the C14+ pipe (120) are in communication with the deoxygenation unit (110); a first adsorbent bed containing a first adsorbent comprising alkaline or alkaline earth cation exchange zeolite X, and being in communication with a first pipe (130); a decontaminated stream line (145) that is in communication with the first adsorbent bed; and a dehydrogenation unit (150) that is in communication with the decontaminated current pipe (145); a dehydrogenated stream line (155) that is in communication with the dehydrogenation unit (150); 2. The apparatus according to claim 1, further comprising: a selective hydrogenation unit (160) that is in communication with the dehydrogenated stream line (155); and a monoolefin flow line (170) that is in communication with the selective hydrogenation unit (160). 3 The apparatus according to claim 1 or 2, further comprising: an alkylation unit (175) that is in communication with the monoolefin pipeline (170); and an alkylation effluent line (185) that is in communication with the alkylation unit (175). 4. The apparatus according to any of the preceding claims, further comprising: a benzene separation unit (190) that is in communication with the alkylation effluent line (185); a linear alkylbenzene product line (205); and a benzene recycling pipe (195); wherein the linear alkylbenzene product line (205) and the benzene recycle line (195) are in communication with the benzene separation unit (190). 5. The apparatus according to any of the preceding claims, further comprising: a linear selective cracking unit (125) that is in communication with the C14+ pipeline (120), a first pipe (130) that is in communication with the linear selective cracking unit (125); and a second pipe (135); wherein the first pipe (130) and the second pipe (135) are in communication with the linear selective cracking unit (125). 6. The apparatus according to claim 1, further comprising a second adsorbent bed containing a second adsorbent comprising zeolite 5A. 7. The apparatus according to claim 1, further comprising a third adsorbent bed containing a third adsorbent comprising zeolite 13X, zeolite 5A, an alumina-zeolite, or combinations thereof.