Process for producing renewable product streams - Patent Application 20070122997

Abstract

Biorenewable feeds enriched in free fatty acids are produced by hydrodeoxygenating biorenewable feedstocks using Group VIII catalysts to produce products with 10-13 carbon atoms and high levels of linearity. Normal paraffins in the range desired by the detergent industry can be produced. Either isomerization or iso-linear separation can be performed to provide green fuel streams.

Description

[Technical Field]

[0001] The field is processes for producing product streams from renewable feed streams. Specifically, the field is processes for producing cleaning agent and fuel streams from renewable feed streams. [Background technology]

[0002] Linear alkylbenzenes have the formula C6H5C n H 2n+1 The alkyl benzenes are organic compounds having the following structure: The alkyl carbon number "n" can have any practical value, but detergent manufacturers prefer alkyl benzenes to have alkyl carbon numbers in the range of 9 to 16, preferably 10 to 13. These specific ranges are often required when alkyl benzenes are used as intermediates in the production of detergent surfactants. Alkyl carbon numbers in the range of 10 to 13 meet detergent industry specifications.

[0003] Because surfactants produced from alkylbenzenes are biodegradable, the production of alkylbenzenes has grown rapidly since their first use in detergent production in the 1960s. The linearity of the paraffin chains in alkylbenzenes is important to the biodegradability of the material and its effectiveness as a cleaning agent. The primary factor in the final linearity of the alkylbenzene is the linearity of the paraffin component.

[0004] While detergents made utilizing alkylbenzene-based surfactants are biodegradable, the process for making alkylbenzenes prior to their creation is not based on renewable sources. In particular, alkylbenzenes are currently produced from kerosene refined from crude oil extracted from the earth. Increasing environmental bias against fossil fuel extraction and growing economic concerns about depleting fossil fuel deposits may support the use of alternative sources of biodegradable surfactants in detergent and other industries.

[0005] It is therefore desirable to provide linear alkylbenzenes with a high degree of linearity that are produced from biorenewable resources rather than mined from the earth. It is also desirable to provide renewable linear alkylbenzenes from easily processed triglycerides and fatty acids from vegetable, animal, nut, and / or seed oils. Palm kernel oil, coconut oil, and babassu oil have compositions rich in the desirable range of C10-C13 n-paraffins, matching the alkyl carbon number range required by the detergent industry. Such renewable resources are rich in nC16-nC18 feeds, and it is desirable to be able to convert these feeds to nC10-nC13 feeds with high per-pass yields. These nC10-nC13 intermediate products are useful for the ultimate production of linear alkylbenzene-type detergents through additional processing steps. Furthermore, it is desirable that the resulting nC10-nC13 paraffins be linear products with minimal branched-chain isomer products.

[0006] Biofuel can be co-produced with linear alkylbenzenes. Other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background. Summary of the Invention

[0007] The present inventors have discovered that biorenewable feeds enriched in free fatty acids having 10-13 carbon atoms can be converted to paraffinic compositions favorable for detergent alkylation by using preferred catalysts, such as supported Group VIII metal catalysts, e.g., Ru-ZrO2, Pt-Al2O3, or Ni-ZrO2. The nC10-nC13 yield per pass from the novel catalyst and process can be significantly higher (approximately 30%) than the yield obtainable from prior art processes (approximately 5%). It has been found that the yield of the desired C10-13 can vary depending on the catalyst used, with the linearity of C10-C13 being preferred, and the amount of methane produced as a by-product.

[0008] Further details and embodiments of the present disclosure will become apparent from the following detailed description of the present disclosure. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a schematic diagram of a conversion unit of the present disclosure. [Figure 2] FIG. 2 is a schematic diagram of another conversion unit of FIG. 1; [Figure 3] FIG. 3 is a schematic diagram of a benzene alkylation unit useful with either the conversion unit of FIG. 1 or FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present disclosure seeks to produce alkylbenzenes from renewable resources for detergent production and jet fuel and / or diesel. The feedstock for linear alkylbenzene production is linear C10-C13 paraffins. Therefore, it is necessary to process triglycerides and fatty acids that, when hydrodeoxygenated, produce linear paraffins with 16-18 carbons. These materials are longer in length than detergent manufacturers desire. Some renewable resources, such as palm kernel oil (PKO), coconut oil, and babassu oil, have fatty acids that, when deoxygenated, produce linear paraffins with 10-13 carbons. Linear paraffins with 10-13 carbons are the desired number of carbons that detergent manufacturers desire for adding alkyl groups to alkylbenzenes used in detergents. Broadly speaking, it has been discovered that it would be desirable to be able to employ a wide range of C16-C22 fats, oils, and greases (FOGS) to produce the desired linear C10-C13 product stream by hydrocracking. The feed stream is optionally treated to remove catalyst-deactivating sulfur and is also subjected to hydrotreating. The difference between the catalysts used for hydrotreating and hydrocracking is that the hydrocracking catalyst is reduced.

[0011] The inventors have discovered that by selecting a specific metal catalyst, they can produce linear paraffins with 10 to 13 carbon atoms in much higher yields than conventional processes. Compared to the traditional LAB process, where the feed is derived from petroleum, this process starts with nC16 to nC18 hydrocarbons derived from renewable resources such as soybeans. This renewable n-paraffin feed is typically obtained by hydrodeoxygenation of triglycerides in processes such as Ecofining by UOP LLC (Des Plaines, Illinois, USA). Using the catalyst used herein, they found that the nC16 to C18 feed can produce linear cracked products without producing branched isomers.

[0012] Among the preferred catalysts, the Ru catalyst exhibits much higher activity and much higher nC10-nC13 yields per pass than other catalysts. Under optimized reaction conditions, it also produces very small amounts of methane and isomerized products. It has been found to be the best catalyst for such chemical conversion processes. The Pt-Al2O3 catalyst may result in even lower methane yields and slightly lower linear product yields than the Ru-based catalyst.

[0013] To limit catalyst deactivation, the feed is treated to remove sulfur contamination of the supported catalyst. Without this treatment, sulfur buildup on the catalyst leads to deactivation. High-temperature hydrotreating has been shown to restore some of the lost activity. The extent of hydrodeoxygenation can affect selectivity for each of the normal paraffins in the 10-13 carbon range. A high degree of hydrodeoxygenation can result in a hydrodeoxygenated composition that is heavily biased toward normal dodecane and normal decane, to the detriment of normal undecane and normal tridecane. A low degree of hydrodeoxygenation can result in a hydrodeoxygenated composition that is heavily biased toward normal undecane and normal tridecane, to the detriment of normal dodecane and normal decane. We have found that 35-60% hydrodeoxygenation results in a hydrodeoxygenated composition containing normal undecane, normal dodecane, and normal tridecane within the range required by detergent specifications for at least these n-paraffins. The linear decane is low in both cases and can be topped up to meet detergent specifications.

[0014] Other vegetable oils with fatty acids in the 15-20 carbon range are typically subjected to advanced hydrodeoxygenation to obtain jet fuel or diesel-range paraffins. Advanced hydrodeoxygenation is not equivalent to the moderate hydrodeoxygenation of PKO, coconut oil, and babassu oil, which are best for detergent production. In current processes, the hydrodeoxygenation of other feedstreams is decoupled from the hydrodeoxygenation of biorenewable streams, such as PKO, coconut oil, and babassu oil, to produce linear paraffins with 10-13 carbon atoms, improving the yield of the hydrodeoxygenated compositions desired for detergent production.

[0015] The temperature of the hydrodeoxygenation reactor is kept low, below 343°C (650°F) for typical biorenewable feedstocks, and below 304°C (580°F) for feedstocks with higher free fatty acid (FFA) concentrations to avoid polymerization of the olefins found in the FFA. Generally, a hydrodeoxygenation reactor pressure of about 700 kPa (100 psig) to about 21 MPa (3000 psig) is suitable.

[0016] As used herein, the term "separator" means a vessel having an inlet and at least a top vapor outlet and a bottom liquid outlet, and may also have an aqueous outlet from a boot. A flash drum is a type of separator that may be in downstream communication with a separator that may be operated at a higher pressure. The term "communication" means that fluid flow is operably permitted between the listed components, which may be characterized as "fluid communication." The term "downstream communication" means that at least a portion of the fluid flowing to an object in downstream communication can operably flow from the object in fluid communication.

[0017] The term "column" refers to a distillation column or columns for separating one or more components of different volatility. Unless otherwise indicated, each column includes a condenser at the top of the column for condensing and refluxing a portion of the overhead stream returning to the top of the column, and a reboiler at the bottom of the column for vaporizing and returning a portion of the bottom stream to the bottom of the column. The feed to a column may be preheated. The overhead pressure is the pressure of the overhead vapor at the vapor outlet of the column. The bottom temperature is the liquid bottom outlet temperature. Unless otherwise specified, the overhead and bottom lines refer to the net lines from column to column downstream of any reflux or reboil return. A stripper column may omit the reboiler at the bottom of the column and instead provide the heating requirements and driving force for separation from a fluidizing inert medium such as steam.

[0018] The catalyst used in the hydrocracking reaction is selected from Ru / ZrO2 catalyst, Pt-Al2O3 catalyst, Ni-alumina, or NiO / clay.

[0019] Preferred hydrotreating reaction conditions are a hydrotreating catalyst or combination of hydrotreating catalysts at a temperature of from about 290°C (550°F) to about 455°C (850°F), suitably from 316°C (600°F) to about 427°C (800°F), preferably from 343°C (650°F) to about 399°C (750°F), a pressure of from about 2.8 MPa (gauge) (400 psig) to about 17.5 MPa (gauge) (2500 psig), for about 0.1 hours. -1 , appropriately 0.5 hours -1 ~approx. 5 hours -1 , preferably about 1.5 to about 4 hours -1 and a liquid hourly space velocity of about 84 Nm 3 / m 3 (500scf / bbl)~Approx. 1,011Nm 3 / m 3 Oil (6,000 scf / bbl), preferably about 168 Nm 3 / m 3 Oil (1,000scf / bbl) ~ approx. 1,250Nm 3 / m 3 Includes hydrogen rate of oil (7,500 scf / bbl).

[0020] As used herein, the term "component-rich stream" or "component stream" means that the stream exiting a vessel has a higher concentration of that component than the feed to the vessel. As used herein, the term "component-lean stream" means that the lean stream exiting a vessel has a lower concentration of the component than the feed to the vessel.

[0021] The basic process design is shown in Figure 1, where a sustainable feedstock feed 40, such as nC16-nC18 rich palm kernel oil or coconut kernel oil, is sent and combined with a later effluent 35 from hydrocracking reactor 30 and sent to hydrotreating reactor 45. Effluent 50 from hydrotreating reactor 45 is sent to separator 55, where bottoms stream 57 is split into stream 56, which is combined with feed 40, and stream 58, which is combined with hydrogen stream 10 sent to hydrocracking reactor 30 in stream 20. Tops stream 60 is sent to vessel 65, stream 67, and separator 70, where it is split into stream 75, sent through compressor 85 to stream 90, and combined with stream 96 to be sent to hydrotreating reactor 45. Stream 72 is sent to column 74 and split into off-gas 79, LPG 78, LNAP 77, and HNAP 76.

[0022] Figure 2 illustrates an embodiment using a hydrotreating reactor and a hydrocracking reactor in series, employing a catalyst of the present invention, to produce higher levels of desired C10-C13 carbon for use in producing more linear alkylbenzenes. A vegetable oil stream 100 is sent to a hydrotreating reactor 105 containing two different catalysts, such as the Ru-, Pt-, Mo-, or Ni-containing catalysts described above. The hydrotreated hydrocarbon stream 100 is sent to a separator 115 to produce a lighter stream 130 to be recycled to the vegetable oil stream 100, a stream 120 to be recycled, and a stream 135 to be sent to a hydrocracking reactor 145 containing a partial reduction catalyst where the hydrocarbons are cracked into a mixture containing C2-C13 hydrocarbons. These hydrocarbons are sent to a column 165 to separate the off-gas 170, a light hydrocarbon stream 185 to a steam cracker, and a C10-C13 hydrocarbon stream 180, which are then reacted to produce linear alkylbenzene products. Stream 175 is sent to the isomerization reactor and a portion of stream 175 is recycled and sent back through hydrocracking reactor 145 .

[0023] Figure 3 shows an embodiment in which hydrotreating and hydrocracking occur in the same reactor section. Feed 200, treated to remove sulfur, is combined with a supply of make-up hydrogen 205 and enters the upper part of reactor 210, which has a low-temperature catalyst in the upper part of the reactor and a high-temperature catalyst in the lower part of the reactor. The resulting stream 21 is sent to separator 220, and a light hydrocarbon portion 260 is returned to be combined with feed 200. The heavier hydrocarbon-containing portion is sent in line 222 to column 235, where it is separated into off-gas stream 240, LPG stream 245, and LNAP stream 250, which contains linear C10-C13 products and is further reacted to produce linear alkylbenzenes. Stream 270 is sent to the isomerization reactor.

[0024] Below are some examples of the use of different catalysts to crack paraffins into the desired C10 to C13 paraffins.

[0025] Example 1 The n-C15 feed was treated with 0.75 wt% Cl at 340°C, 500 psig, and 1 h -1 WHSV, 10H2 / HC, 1 g of catalyst in contact with 0.75 wt% Pt on γ-alumina gave 25% n-C15 conversion and a 9.5% C2 to C8 yield. The yield of C1 was 0.78%, C2-C8 38.18%, C9-C12 37.59%, C13 and C14 13.10%, and iC15 10.35%. The benefit observed was lower methanogenesis, but there was low activity and high isomerization levels that could limit recycle.

[0026] Example 2 The n-C15 feed was heated at 245°C, 200 psig, and 2 h -1 WHSV, 25H2 / HC, 0.5 g of catalyst in contact with 0.5 wt% Ru on ZrO2 gave 75% n-C15 conversion and 26.0% C2 to C8 yield. Yields were 8.36% for C1, 34.65% for C2-C8, 34.60% for C9-C12, 21.94% for C13 and C14, and 0.44% for iC15. Advantages observed were higher activity and lower isomerization levels, but higher methane production than with Pt-based catalysts.

[0027] Example 3 Table 1 shows experimental results from several different catalysts, including catalysts containing Pt on alumina, Ni on alumina, NiO on clay, and Ni on alumina dispersed on an inert core. In general, it is preferable to maximize the yield of linear C10-C13, maximize linearity, and minimize methane by-product levels.

[0028] [Table 1]

Claims

1. C １６ ~C ２２ Carbon-containing biorenewable feedstreams are referred to as C １０ Straight chain to C １３ 1. A process for converting a biorenewable feed stream into a normal paraffin stream, comprising first treating the biorenewable feed stream to remove sulfur and producing a sulfur-free feed stream, and converting the sulfur-free feed stream into Ru—ZrO in a cracking reactor. ２ , Pt-Al ２ O ３ , Ni—ZrO ２ and a Mo-containing catalyst or a mixture thereof.

2. 2. The process of claim 1, wherein the catalyst comprises Ru—ZrO2 (0.1 wt %).

3. 10. The process of claim 1, wherein the catalyst comprises about 5-10 wt. % Mo on alumina.

4. The process of claim 3, wherein the catalyst further comprises about 0.05 to 0.5 wt. % Ni.

5. The biorenewable feed stream is subjected to an additional conversion process to an intermediate stream comprising normal paraffins, and at least a portion of the intermediate stream comprising normal paraffins is converted to the C １０ Straight chain to C １３ 2. The process of claim 1, wherein the olefin is converted into a normal paraffin stream.

6. Said C １０ ~C １３ 10. The process of claim 1, wherein the paraffin stream has a linearity of greater than 98%.

7. 10. The process of claim 1, further comprising treating the C10 normal to C13 normal paraffin stream to remove branched C10 to C13 hydrocarbons.

8. 10. The process of claim 1, wherein the sulfur is removed from the biorenewable feed stream by passing the biorenewable feed stream or partially converted biorenewable feed stream through an adsorption bed before passing the biorenewable feed stream to contact the catalyst.

9. 10. The process of claim 1, wherein the process produces less than 25% by weight of methane.

10. The feed stream is first sent to a hydrotreating reactor and then to a reactor to form the C １０ ~C １３ a normal paraffin feed stream is produced, and then said C １０ ~C １３ 10. The process of claim 1, wherein a normal paraffin feed stream is sent to be converted to linear alkylbenzenes.

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