KR100963324B1 - Process for producing selected phenyl-alkanes with adsorptive separation step - Google Patents

Abstract

According to the invention, a) a feed stream comprising a first acyclic C _8-28 paraffin at a first concentration comprising two or three primary carbon atoms and at least a second acyclic paraffin, the first acyclic passing under conditions promoting adsorption, which selectively adsorbs at least a portion of paraffins to adsorption zone containing an adsorbent phase including silicalite and, C _5-8 cycloalkyl paraffin, C _5-8 C _5-8 branched paraffins and normal paraffins Contacting the adsorbent bed with a desorbent stream comprising at least one component selected from the group consisting of and recovering from the adsorption zone an adsorbent extract comprising a first acyclic paraffin at a second concentration higher than the first concentration. step;

b) passing at least a portion of the adsorptive extract into the dehydrogenation zone, manipulating the dehydrogenation zone under dehydrogenation conditions sufficient to dehydrogenate the first acyclic paraffin, and then having a ratio comprising two or three primary carbon atoms. Recovering the dehydrogenated product stream containing cyclic C _8-28 monoolefins from the dehydrogenation zone;

c) sufficient to pass each of the feedstock comprising the phenyl compound and at least a portion of the dehydrogenated product stream comprising the acyclic monoolefin into an alkylation zone and alkylate the phenyl compound with the acyclic monoolefin in the presence of an alkylation catalyst. Manipulating the alkylation zone under alkylation conditions to form phenyl-alkanes comprising molecules having one phenyl moiety and one C _8-28 aliphatic alkyl moiety wherein the aliphatic alkyl moiety has two or three primary carbon atoms; And do not contain quaternary carbon atoms which are not bound by a carbon-carbon bond with a carbon atom of the phenyl moiety, and the alkylation step has a selectivity of 40 to 100 for 2-phenyl-alkanes and a selection for internal quaternary phenyl-alkanes Is less than 10]

d) recovering the phenyl-alkanes from the alkylation zone

Provided is a method for preparing phenyl-alkane comprising:

Description

PROCESS FOR PRODUCING SELECTED PHENYL-ALKANES WITH ADSORPTIVE SEPARATION STEP}

The present invention relates to selective methods of preparing phenyl-alkane and phenyl-alkane sulfonate compositions and to these compositions and the use of these compositions.

Thirty years ago, various household laundry detergents were prepared with branched alkylbenzene sulfonates (BABS). BABS is made from alkylbenzenes of the type called branched alkylbenzenes (BAB). Alkylbenzene (phenyl-alkane) refers to a general class of compounds wherein an aliphatic alkyl group is bonded to a phenyl group and represented by the formula (m _i -alkyl _i ) _i -n-phenyl-alkane. Aliphatic alkyl groups may also consist of one or more alkyl group branches, designated by the corresponding "(m _i -alkyl _i ) _i ".

The standard process used in the petrochemical industry to produce BAB consists of oligomerizing light olefins, especially propylene, into branched olefins of C _10-14 and then alkylating benzene to branched olefins in the presence of a catalyst such as HF. do. The product BAB comprises a number of alkyl-phenyl-alkanes represented by the formula (m _i -alkyl _i ) _i -phenyl-alkanes, but two examples of BAB are m-alkyl-m-alkyl-n-phenyl-alkanes Where m is n, and m-alkyl-m-phenyl-alkane, where m ≧ 2.

The most prominent feature of BAB is that, for most BABs, at least one alkyl group branch, more generally at least three alkyl group branches, is attached to the aliphatic alkyl chain of BAB. If any alkyl group branching itself is branched, the aliphatic alkyl group of BAB has more primary carbon atoms. Thus, the aliphatic alkyl groups of BAB generally have three, four or more primary carbon atoms. Each alkyl group branch is generally a methyl group branch, although ethyl, propyl or higher alkyl group branches are also possible.

Another typical feature of BAB is that the phenyl group is bonded to any non-primary carbon atom of the aliphatic alkyl chain. Neglecting the relatively small effect of branching of branched paraffins, except for 1-phenyl-alkanes, whose formation is undesirable due to the relative instability of primary carbenium ions, depending on the length of the aliphatic alkyl chain in the oligomerization step Randomly distributed carbon-carbon double bonds are generated, and in the alkylation step, phenyl groups are bonded almost randomly to carbon along the aliphatic alkyl chain. Thus, for example, a BAB with an aliphatic alkyl chain of C ₁₀ is estimated to have a random distribution of approximately 2-, 3-, 4- and 5-phenyl-alkanes, and 2-phenyl- if the distribution is completely random. The selectivity for alkanes is 25, but typically 10-40.

BAB usually has one quaternary carbon as one of the carbon atoms of the aliphatic alkyl group. The quaternary carbon may be bonded to the carbon in the phenyl group by a carbon-carbon bond. In this case, the molecule is referred to as "quaternary alkyl-phenyl-alkane" or hereinafter simply "quaternary compound" and includes alkyl-phenyl-alkanes represented by the formula m-alkyl-m-phenyl-alkanes. A "terminal quaternary compound" constitutes a 2-alkyl-2-phenyl-alkane wherein the secondary carbon atoms derived from the ends of the alkyl side chains are quaternary. Quaternary compounds comprising quaternary carbon at other positions form alkyl-phenyl-alkanes referred to as "internal quaternary compounds". Existing methods for producing BAB form internal quaternary compounds at relatively high proportions, typically at least 10 mole percent.

Household laundry detergents made from BABS are increasingly polluting rivers and lakes. BABS was found to be slow biodegradable. Such problems have been reduced by the use of straight chain alkylbenzene sulfonates (LABS) which biodegrades more rapidly than BABS. LABS is prepared from straight chain alkylbenzenes (LABs). In the petrochemical industry, LAB is prepared by dehydrogenation of straight chain paraffins with straight chain olefins and then alkylation with benzene in the presence of HF or a solid catalyst. LAB includes a linear aliphatic alkyl group and a phenyl group, and is represented by the formula n-phenyl-alkane. LAB has no alkyl group branching and usually has two primary carbon atoms (ie n ≧ 2). In standard LAB processes, a phenyl group is bonded to any secondary carbon atom of a linear aliphatic alkyl group. Alkylation under an HF catalyst is slightly more likely to link a phenyl group to a secondary carbon atom near the center of a linear aliphatic alkyl group. LAB prepared by the Detal ^™ process contains 2-25-35 mole% of n-phenyl-alkanes as 2-phenyl-alkanes.

Recent studies have identified modified alkylbenzene sulfonate "MABS", which compounds all commercially available alkylbenzene sulfonates and HF, aluminum chloride, silica-alumina, fluorinated silica-alumina, zeolites and fluorine It differs from all alkylbenzene sulfonates prepared by conventional alkylbenzene processes, including those using ized zeolites as catalysts. Compared with LABS, MABS has improved washing detergency, has a hard surface cleaning performance, and has good biodegradability similar to LABS while having good efficacy in hard and / or cold water.

MABS can be prepared by sulfonating a third type of alkylbenzene, called modified alkylbenzene (MAB), and the desired solubility, surfactant activity and biodegradability of the MABS determine the desired properties of the MAB. MABs include many phenyl-alkanes, some of which may also be found in LAB and BAB, but the corresponding phenyl-alkanes are undesirable phenyl-alkanes for MAB. The phenyl-alkanes of MAB are phenyl-alkanes comprising slightly branched aliphatic alkyl groups and phenyl groups, represented by the formula (m _i -alkyl _i ) _i -n-phenyl-alkanes. Phenyl-alkanes of MAB generally have only one alkyl group branch, n ≠ 1, and MAB has three primary carbons. Preferred MAB phenyl-alkanes are monomethyl-phenyl-alkanes. However, when there is only one alkyl group branch and n = 1, the MAB may include two primary carbon atoms, or when the alkyl group branch is two and n ≠ 1, the MAB may include four primary carbons. Thus, a first feature of MAB is the average number of primary carbons in the aliphatic alkyl groups of the phenyl-alkane intermediates of BAB and LAB. The high ratio of 2-phenyl-alkanes is also characteristic of MAB. That is, 40-100% of the phenyl group is optionally bonded to the second carbon atom of the alkyl side chain.

As a final feature, MAB alkylates comprise internal quaternary compounds in relatively low proportions, typically less than 10 mole percent. Some internal quaternary compounds such as 5-methyl-5-phenyl-undecane produce slow biodegradable MABS. MABS with terminal quaternary compounds such as 2-methyl-2-phenyl-undecane show similar biodegradability as LABS. See, "Biodegradation of Coproducts of Commercial Linear Alkylbenzene Sulfonate," by A. M. Nielsen et al., In Environmental Science and Technology, Vol. 31, No. 12, 3397-3404 (1997).

PCT International Publications WO 99/05082, WO 99/05084, WO 99/05241, and WO 99/05243, published February 4, 1999, inherently alkylate to slightly branched or dechained alkylbenzenes. The process is starting. PCT International Publication No. WO 99/07656, published February 18, 1999, discloses a process using adsorptive separation for such alkylbenzenes.

Because of the advantages of MABS superior to other alkylbenzene sulfonates, there is a need to develop catalysts and processes that produce MABs with selectivity to 2-phenyl-alkanes and selectivity to exclude internal quaternary phenyl-alkanes.

Summary of the Invention

In one aspect, the invention relates to a process for preparing phenyl-alkanes, especially modified alkylbenzenes (MABs), by adsorptive separation, dehydrogenation and alkylation. This method features the composition of adsorbent and desorbent pairs used herein. The adsorbent used is silicalite and the desorbent comprises C _5-8 straight paraffin, C _5-8 cycloparaffin and / or branched paraffins, preferably isooctane.

In one embodiment of the method, a paraffin feed stream comprising a first acyclic C _8-28 paraffin and a second acyclic paraffin having two or three primary carbon atoms at a first concentration is passed through an adsorption zone. The adsorption zone includes an adsorbent phase comprising silicalite under adsorption promotion conditions that selectively adsorb at least a portion of the acyclic paraffins having two or three primary carbon atoms. C _5-8 causes the desorbent stream comprising the paraffins cycloalkyl, C _5-8 normal paraffin and one or more of C _5-8 branched paraffin into contact with the adsorbent. The adsorption extract containing the first acyclic hydrocarbon is recovered from the adsorption zone at a second concentration higher than the first concentration. At least a portion of the adsorbed extract is passed through a dehydrogenation zone operating under dehydrogenation conditions sufficient to dehydrogenate the first acyclic paraffin. A dehydrogenated product stream comprising C _8-28 acyclic monoolefins having 2 or 3 primary carbon atoms is recovered from the dehydrogenation zone. An aromatic feedstock comprising at least a portion of the phenyl compound and the dehydrogenated product stream is passed through an alkylation zone operating under alkylation conditions sufficient to alkylate the phenyl compound with an acyclic monoolefin in the presence of an alkylation catalyst. In the alkylation zone phenyl-alkanes containing molecules having one phenyl moiety and one C _8-28 aliphatic alkyl moiety having two or three primary carbon atoms and no quaternary carbon atoms except quaternary compounds This is recovered. The alkylation step has a selectivity of 40 to 100 for 2-phenyl-alkanes and less than 10 for internal quaternary phenyl-alkanes. In a preferred embodiment, the alkylation step has a selectivity of less than 10, more preferably less than 1 for non-quaternary compounds.

In a preferred method embodiment, the present invention forms a MAB composition comprising phenyl-alkanes having one phenyl group and one aliphatic alkyl group. Phenyl-alkanes also have an average weight of aliphatic alkyl groups of phenyl-alkanes between the weight of C ₁₀ aliphatic alkyl groups and the weight of C ₁₃ aliphatic alkyl groups; The content of phenyl-alkane having a phenyl group bonded to the 2- and / or 3-position of the aliphatic alkyl group is at least 55% by weight of the phenyl-alkane; When the total content of 2-phenyl-alkanes and 3-phenyl-alkanes is at least 55% by weight of phenyl-alkanes and at most 85% by weight, the average branching level of aliphatic alkyl groups of phenyl-alkanes is 0.25-1.3 per molecule of phenyl-alkanes. Branching of two alkyl groups, or when the sum of the concentrations of 2-phenyl-alkanes and 3-phenyl-alkanes is at least 85% by weight of phenyl-alkanes, the average branching level of aliphatic alkyl groups of phenyl-alkanes is 0.4 per molecule of phenyl-alkanes. -1.3 alkyl group branches. In addition, the aliphatic alkyl group of phenyl-alkane mainly comprises a linear aliphatic alkyl group and a single branched aliphatic alkyl group, and the alkyl group branch on the aliphatic alkyl chain of the aliphatic alkyl group mainly contains a small substituent such as a methyl group branch, an ethyl group branch, or a propyl group branch. And alkyl group branching at any position on the aliphatic alkyl chain of the aliphatic alkyl group, but phenyl-alkanes having at least one quaternary carbon atom on the aliphatic alkyl group should constitute less than 20% of the phenyl-alkanes.

The present invention forms detergents which, when used in detergent alkylation, meet stringent conditions of increasing trend for internal quaternary phenyl-alkane selectivity and 2-phenyl-alkane selectivity for MAB preparation, wherein the MAB is hard water and / Alternatively, in cold water, the cleaning effect can be improved and sulfonated to produce MABS with biodegradation similar to LAS.

In another aspect, the present invention forms particular carbon-branched specific MAB and MABS producing compositions that differ from conventional methods. In another aspect, these resulting MABs and MABS can be used as lubricants or lubricant additives, respectively.

1 illustrates an embodiment of the invention.

2 is a concentration profile for pulse test separation.

Detailed description of the invention

The process uses a feed mixture comprising paraffins, and feedstock comprising phenyl compounds is consumed in the process. The feed mixture comprises C _8-28 acyclic paraffins. Acyclic paraffins are preferably "slightly branched paraffins" and mean herein paraffins having 3 or 4 primary carbon atoms and containing no quaternary carbon atoms. Usually, the total number of carbon atoms of the slightly branched paraffins is 9-16, preferably 10-14, more preferably 10-13. Slightly branched paraffins include aliphatic alkanes generally represented by the formula (p _i -alkyl _i ) _i -alkanes.

Slightly branched paraffins generally comprise at least 30 mol%, preferably at least 70 mol% of the feed mixture. Branching of alkyl groups generally includes methyl, ethyl and propyl groups, with shorter branches being preferred. Preferably, the slightly branched paraffin contains only one alkyl group branch, and preferably constitutes at least 85 mol% of the slightly branched total paraffins. Slightly branched paraffins with two alkyl branch or four primary carbon atoms generally comprise less than 30 mol%, preferably less than 15 mol% of the slightly branched total paraffins.

The feed mixture may also comprise one or more unbranched (straight chain) or normal paraffin molecules having 8 to 28, more preferably 10 to 13, total carbon atoms per paraffin molecule. The concentration of unbranched paraffin in the feed mixture is often at least 0.3 mol%.

In addition to slightly branched paraffins and unbranched paraffins, other highly branched acyclic compounds may be present in the feed mixture. However, such highly branched paraffins tend to form highly branched monoolefins upon dehydrogenation, which are likely to form BAB upon alkylation. For example, paraffin molecules composed of one or more quaternary carbon atoms tend to form phenyl-alkanes having quaternary carbon atoms in the aliphatic alkyl moiety that are not quaternary compounds in the dehydrogenation step and subsequent alkylation steps. Therefore, it is desirable to minimize the amount of highly branched paraffins introduced into the process. Paraffin molecules composed of one or more quaternary carbon atoms generally constitute less than 10 mol%, preferably less than 5 mol%, more preferably less than 2 mol%, most preferably less than 1 mol% of the feed mixture.

Feed mixture preparation is not an essential component of the present invention and any suitable method for preparing the feed mixture may be used. The carbon number range of the feed mixture required for the preparation of the MAB is usually 9-16, which corresponds to the paraffin boiling in the kerosene boiling range, so that the kerosene fraction forms the appropriate feed mixture precursor. Kerosene preparations are inherently inaccurate, resulting in mixtures of compounds. The feed mixture for the process may comprise a certain amount of paraffins having a plurality of branches and paraffins having a plurality of carbon atoms in the branch, cycloparaffins, branched cycloparaffins or other compounds having a boiling point relatively similar to the desired compound isomer. The kerosene fraction comprises a number of different hydrocarbons, so the feed mixture for this process may comprise more than 200 different compounds, including significant amounts of aromatic hydrocarbons. Typically the fraction recovered from crude oil by fractional distillation must be treated with a hydrotreating step to remove sulfur and / or nitrogen prior to feeding the process.

However, the separation process, rather than oligomerization or other forms of synthesis, provides a suitable feed mixture at a lower cost and will therefore be a major source of feed mixture. A preferred method for preparing the feed mixture is to separate unbranched (straight chain) hydrocarbons or slightly branched hydrocarbons from the petroleum fraction in the kerosene boiling range. Several methods of realizing such separation are known. One method has been established, the UOP Molex ^™ process, which is an industrially proven method for the liquid phase adsorptive separation of normal paraffins from isoparaffins, cycloparaffins and aromatics using UOP Sorbex separation. Another suitable process established and confirmed is the UOP Kerosene Isosiv ^™ process, which utilizes vapor phase adsorption to separate normal paraffins from non-normal paraffins using molecular sieves in an adsorption vessel. See Chapters 10.3, 10.6 and 10.7 in the book entitled Handbook of Petroleum Refining Process, Second Edition, edited by Robert A. Meyers, published by McGraw-Hill, New York, 1997.

Raffinate streams of adsorptive separation processes, such as the UOP Molex ^™ process, which selectively recover unbranched (straight chain) paraffins from the extract stream, are particularly preferred feed mixtures for this process. The raffinate stream from such a process is free of contaminants such as sulfur containing compounds or nitrogen containing compounds, and contains unbranched paraffins and olefins at appropriately low concentrations. The use of such a raffinate stream as a feed mixture allows the process to be integrated into existing LAB equipment, allowing two adsorptive separation stages to be carried out in series. Separately recovered normal paraffin streams and feed mixtures can be treated by various methods. For example, each of the unbranched paraffinic streams and feed mixture can be treated independently with a dehydrogenation step and an aromatic alkylation step to produce two separate products. Alternatively, the unbranched paraffin stream and feed mixture can be used to form the desired paraffin blend. That is, the stream introduced into the dehydrogenation zone of the process may comprise 10-50 volume percent of unbranched paraffins with the product of the separation zone of the process.

The composition of mixtures of olefins as well as straight chain, slightly branched and branched paraffins can be determined by assays known to those skilled in the gas chromatography art. A paper by H. Schulz et al. And published in Chromatographia 1, 1968, p315 discloses a temperature-programmed gas chromatography apparatus and method suitable for identifying components in complex mixtures of paraffins or olefins. One skilled in the art can substantially separate and identify the components in the paraffin mixture using substantially the apparatus and methods disclosed in the paper by Schulz et al.

The aromatic-containing feedstock for this process includes a phenyl compound, where the phenyl compound is benzene when the process is detergent alkylation. In a more general case, the phenyl compounds of the aromatic feedstock may be alkylated or otherwise substituted derivatives or of higher molecular weight than benzene, including toluene, ethylbenzene, xylene, phenol, naphthalene, and the like.

In the adsorptive separation section, slightly branched acyclic paraffins are separated from the feed mixture. The separation step can be carried out in continuous mode or in batch mode, including the use of two or more adsorbent beds in the cyclic operation. In this mode one or more phases are used for separation and another phase is regenerated. Separation on a continuous basis offers significant operational and economic advantages. The simulated mobile phase method (SMB) is a preferred method of obtaining continuous operation and uniform product. In the separation step, monomethyl paraffin is preferably recovered from the feed mixture.

SMB adsorptive separation units are known which simulate the movement of adsorbents relative to the feed stream. This simulation is carried out using existing conventional methods, in which multiple subbeds are held in one or more cylindrical adsorbent chambers to hold the adsorbent in place. The position at which the stream associated with the process enters and exits the chamber is gradually moved from sub-phase to sub-phase along the length of the adsorbent chamber so that the stream enters or exits the different sub-phase as the operating cycle progresses. do. Generally, there are at least four streams (feeds, desorbents, extracts and raffinates) used in this procedure, where the feed and desorbent streams enter the chamber and where the extract and raffinate streams exit the chamber at regular intervals. Are moved simultaneously in the same direction. It is common for only one line to be used for each subphase, with each phase line holding one of four process streams at the same point in the cycle. Manifolding systems or rotary disk valves may facilitate circulation of the inlet and outlet streams of this simulation process. The simulation process generally involves the use of a variable flow rate pump, which exits from one end of the adsorbent vessel (s) and pushes the liquid to the other end in a single continuous loop.

The simulated mobile bed process typically includes at least three or four separation steps substantially carried out in separate zones in the adsorbent mass. Each of these bands is usually formed of a number of sub-phases, with the number of phases per band being two or three to eight to ten. The unit of the most widely used process usually contains 24 phases. All phases are contained within one or more vertical vessels, collectively referred to herein as adsorbent chambers. General methods used in the practice of simulated mobile phase adsorptive separation methods are described in detail in Chemical Engineering Progress (Vol 66, No 9), September 1970, p70, as shown in US-A-3,040,777 and US-A-3,422,848. Is disclosed.

In the course of the adsorption step of the process, a feed mixture comprising a mixture of compounds is contacted with an adsorbent under adsorption conditions and one or more compound (s) or class of compounds are selectively adsorbed and retained on the adsorbent, while the feed mixture Other compounds are relatively non-adsorbed. Generally, the desired compound is adsorbed. The feed mixture may comprise various compounds, including isomers of the desired compounds. For example, the mixed xylene feed stream may comprise ethylbenzene and / or C ₉ aromatics and may be treated to recover specific isomers with the appropriate adsorbent / desorbent pairs operating under appropriate conditions. Different sieve / desorbent combinations are used for different separations. For example, X zeolites, in particular X zeolites exchanged with barium or barium and potassium ions at ion exchangeable sites, are the preferred adsorbents for recovering p-xylene from xylene mixtures.

In the next step of the process, the nonadsorbed (rapinate) component of the feed mixture is separated as a raffinate stream from the void space between the adsorbent particles and the surface of the adsorbent. The desorbed step is then contacted with a stream containing desorbent material under desorption conditions to recover the adsorbed compound from the adsorbent. The desorbent is substituted for the desired compound to form an extract stream, which is sent to a fractional distillation zone to recover the desired compound from the desorbent of the extract stream. In some instances, the desired product of the process may be present in the raffinate stream rather than the extract stream.

For the purposes of explanation of the invention, various terms used herein are defined as follows. A "feed mixture" is a mixture comprising one or more extract components and one or more raffinate components to be separated in the adsorption zone of this process. The term "feed stream" means a stream of feed mixture that passes through and contacts the adsorbent. An "extract component" is a compound or class of compounds that is more selectively adsorbed by an adsorbent. A "raffinate component" is a compound or class of compounds that is less selectively adsorbed. The term "desorbent material" means a material capable of desorbing the extract component. The term "raffinate stream" means a stream separated from the adsorbent bed after adsorption of the extract component, which can vary from nearly 100% desorbent material to nearly 100% raffinate component. The term “extract stream” is a stream that has been desorbed by the desorbent material and removed from the adsorbent phase, and may vary from nearly 100% desorbent material to nearly 100% extract components.

Separation means, typically a fractional distillation column, recover all or part of the extract stream and the raffinate stream. Streams containing undesired compounds can be recycled to the isomerization step. Extract streams may be concentrated or contain increased concentrations of the desired compounds. The term "concentration" as used for a process stream means that the specified compound or compound species is at a concentration of at least 50 mol%.

It is customary to place multiple phases in an adsorption chamber in multiple zones. In zone I, the adsorption zone, the feed stream is in contact with the adsorbent. In zone II, the purification zone, undesired isomers are removed as raffinate. In zone III, the desorption zone, the desorbent releases the desired isomer from the adsorbent to recover the desired isomer into the extract stream. Zone IV includes an amount of adsorbent disposed between zones I and III, separating zone 1 and zone III and partially removing the desorbent from the adsorbent. Liquid flow through zone IV prevents zone III from being contaminated by zone I by simulated migration and co-flow of the adsorbent from zone III to zone I. A more detailed description of the simulated mobile phase process is disclosed in Adsorption, Liquid Separation section of the Kirk-Othmer Encyclopedia of Chemical Technoloay.

It is an object of the present invention to provide silicalite adsorbents and branched paraffins; Straight chain paraffins and / or cycloparaffins; Straight chain paraffins and branched paraffins; Or novel adsorbent-desorbent pairs comprising desorbents comprising straight chain paraffins, cycloparaffins and branched paraffins. Preferred desorbents are C _5-8 branched paraffins. Preferred branched paraffins for desorbents are isooctane.

Preferred adsorbents include silicalite. Silicalite is described in reference to Silicalite, A New Hydrophobic Crystalline Silica Molecular Sieve, Nature, Vol. 271, Feb. 9, 1978. Silicalites are hydrophobic crystalline silica molecules with two cross-sectional geometries, MFI-shaped structures of channels perpendicular to the cross direction formed in a 6 kV circular shape and an ellipse with a major axis of 5.1 to 5.7 kPa. Because of this, silicalite has high selectivity as size selective molecular sieve. Due to the aluminum free structure composed of silicon dioxide, silicalite does not exhibit ion exchange action. Thus, silicalite is not a zeolite.

In practicing the present invention, there should be no significant change in operating conditions, adsorbent or desorbent composition in the adsorbent chamber or at different process steps. That is, it is desirable to keep the adsorbent at the same temperature and pressure during the process.

The active ingredient of the adsorbent is generally used in the form of small aggregates having high physical strength and friction resistance. Aggregates, also known as binders, comprise active adsorbent materials dispersed in an amorphous inorganic matrix having channels and cavities therein that allow fluid to access the adsorbent material. The process of forming the crystalline powder into aggregates involves adding an inorganic binder, generally clay comprising silicon dioxide and aluminum oxide, in a high purity adsorbent powder in a wet mixture. Silica is a suitable binder. The adsorbent particles may be in the form of extrudates, tablets, macrospheres, or granules of the desired particle range, preferably 16-60 mesh (US standard mesh) (1.9 mm-250 μm). Kaolin-type clays, water-permeable organic polymers or silicas are generally used as binders.

Those skilled in the art will appreciate that the performance of a particular adsorbent is often greatly influenced by a number of variables not related to the composition, such as operating conditions, feed stream composition, and moisture content of the adsorbent. One such variable is the moisture content of the adsorbent, which is presented herein as a result of a known ignition loss (LOI) test. In the LOI test, the volatile content of the zeolite adsorbent is determined by the weight difference obtained before and after drying the adsorbent sample at 500 ° C. under purging of an inert gas such as nitrogen for a sufficient period of time to obtain a constant weight. In this process, the moisture content of the adsorbent is preferably such that the LOI at 900 ° C. is less than 7.0 wt%, preferably 0 to 4.0 wt%.

The silicalite or other microporous active component of the adsorbent may be in the form of small crystals present in the adsorbent particles, usually in an amount ranging from 75 to 98% by weight, based on the volatile free composition. The volatile free composition is generally measured after the adsorbent is calcined at 900 ° C. to remove all volatiles. The remaining adsorbent is usually the inorganic matrix of the binder.

In the present invention, a feed mixture comprising at least one monomethyl branched hydrocarbon and at least one non-normal hydrocarbon having a similar carbon number but different in structure is passed through at least one adsorbent that selectively adsorbs the monomethyl branched hydrocarbon, Pass the components through the adsorption zone. At some point in time, the flow of feed stream through the adsorbent bed is stopped and the adsorbent section is flushed to remove nonadsorbed material around the adsorbent. The desorbent is then passed over the adsorbent to recover the desired isomer.

The selectivity β of the adsorbent / desorbent pair is the ratio of the two components in the adsorbed phase under equilibrium conditions divided by the ratio of the two components in the unadsorbed phase. Relative selectivity is given by the formula:

Selectivity = [wt% C / wt% D _A ] / [wt% C / wt% D _U ]

Where C and D are the two components of the feed stream expressed in weight percent, and the subscripts A and U represent the adsorbed and unadsorbed phases, respectively. Equilibrium conditions are determined when the composition of the feed stream passing through the adsorbent bed does not change, that is, when there is no net mass transfer between the unadsorbed and adsorbed phases. Relative selectivity is used not only when comparing one feed stream compound to another, but also between any feed mixture component and desorbent material.

An important property of the adsorbent is the rate of exchange of the desorbent to the extract component of the feed mixture. That is, the relative desorption rate of the extract component. The faster the exchange rate, the lower the amount of desorbent material needed to remove the extract components, resulting in lower operating costs of the process. The exchange rate is often temperature dependent. Ideally, in order to desorb the extract component as a class of desorbent material having a reasonable flow rate, the selectivity for the extract component of the desorbent material should exhibit a value of 1 or slightly less than 1, the extract component being subjected to subsequent adsorption steps. It can replace the desorbent material.

In the continuous liquid adsorptive separation process, the desorbent material must be appropriately selected to meet various criteria. Expressed in selectivity, the adsorbent should have a higher selectivity for all extract components for the raffinate component than for the desorbent material for the raffinate component. Desorbent materials should also be suitable and suitable for the particular adsorbent and particular feed mixture.

In general, the adsorption conditions include a temperature in the range of 20 to 250 ° C, more preferably in the range of 40 to 150 ° C. The temperature of 80-140 degreeC is very preferable. The adsorption conditions also preferably include a pressure sufficient to maintain the process fluid in the liquid phase, and may be from atmospheric pressure to 600 psi (g). Desorption conditions generally include the same temperature and pressure as used for the adsorption conditions.

Preferred desorbents include mixtures of normal paraffins, cycloparaffins (naphthenes) and / or branched paraffins. Preferred cycloparaffins are cyclopentane, cyclohexane and methyl cyclohexane. Preferred normal paraffins are n-pentane and n-hexane. Normal paraffin is a powerful desorbent, in fact n-hexane is the strongest desorbent among these compounds. Blends of normal paraffins and cycloparaffins or blends of normal paraffins and isooctane are often preferred to adjust the strength of the desorbent stream. These blends contain from 10 to 90% by volume of cycloparaffin or isooctane, with the remainder being normal paraffin.

The extract stream generally comprises paraffin having 8 to 28, preferably 8 to 15, more preferably 10 to 15 carbon atoms per molecule of paraffin. The extract stream comprises slightly branched paraffins based on total paraffins in the extract stream at a concentration higher than slightly branched paraffins in the feed mixture based on total paraffins in the feed mixture. The slightly branched paraffins with two or four primary carbon atoms in the alkyl group branch are less than 60 mol%, preferably 30 mol% of the slightly branched total paraffins in the portion of the extract stream passing through the dehydrogenation zone of the process. Less than, more preferably less than 15 mol%. Slightly branched paraffin with one alkyl group, more preferably with methyl groups, constitutes at least 85 mole percent of the slightly branched total paraffins of the portion of the extract stream fed to the dehydrogenation zone. When present in an extract stream comprising slightly branched paraffins, the straight chain paraffin content should be no greater than 75 mol% of the total paraffins in the portion of the extract stream fed to the dehydrogenation zone. Paraffin molecules composed of one or more quaternary carbon atoms are generally less than 10 mol%, preferably less than 5 mol%, more preferably less than 2 mol%, most preferably 1 of the extract stream passing through the dehydrogenation zone. It is included in less than mol%.

The dehydrogenation sections can be arranged substantially in the manner shown in the figures. In brief, the stream containing paraffin is combined with recycled hydrogen to form a dehydrogenation reactant stream, heated and contacted with a dehydrogenation catalyst in a fixed bed maintained under dehydrogenation conditions. The catalyst fixed bed effluent, also referred to herein as the dehydrogenation reactor effluent stream, is cooled, partially condensed, and passed through a gas-liquid separator. In the gas-liquid separator, a hydrogen concentrated vapor phase and a hydrocarbon concentrated liquid phase are produced. The condensed liquid phase recovered from the separator is passed through a stripping column to remove all compounds that are more volatile than the light hydrocarbons that are intended to pass to the alkylation section. The olefin containing net stream passing from the dehydrogenation section of the process to the alkylation section is referred to herein as the dehydrogenated product stream.

The present invention is not limited to any particular flow design for the dehydrogenation section, which may include the introduction of a mobile or stationary dehydrogenation catalyst, catalyst containing reaction zones with a heat exchanger in between, and introduction of a hot hydrogen concentrated gas stream. The hydrocarbon can be contacted with any catalyst bed in an upward, downward or radial flow mode.

Dehydrogenation catalysts are described in US-A-3,274,287; US-A-3,315,007; US-A-3,315,008; US-A-3,745, 112; US-A-4,430,517; US-A-4,716,143; US-A-4,762,960; US-A-4,786,625; And known in the art as illustrated in US-A-4,827,072. The selection of specific dehydrogenation catalysts is not critical to the success of the present invention. Preferred catalysts are layered compositions having an inner core bonded to an outer layer comprising a refractory inorganic oxide comprising at least one uniformly dispersed platinum group (Group VIII (IUPAC 8-10)) metal and at least one promoter metal. The modifier metal is dispersed on the catalyst composition. Preferably the outer layer is bonded to the inner core such that the friction loss is in the range of less than 10% by weight based on the weight of the outer layer.

Dehydrogenation conditions are chosen to minimize degradation and polyolefin byproducts. Under typical dehydrogenation conditions, no significant hydrocarbon isomerization takes place in the dehydrogenation reactor. The hydrocarbon may be contacted with a catalyst in the liquid phase, mixed vapor-liquid phase or preferably vapor phase. Dehydrogenation conditions generally range from 400 (752 ° F.) to 900 ° C. (1652 ° F.), preferably from 400 ° C. (752 ° F.) to 525 ° C. (977 ° F.), typically 1 kPa (g) (0.15 psi (g). )) To 1013 kPa (g) (147 psi (g)) and an LHSV of 0.1 to 100 hr ⁻¹ . As used herein, the abbreviation “LHSV” means the hourly space velocity of the liquid, which is the volumetric flow rate of the liquid per hour divided by the catalyst volume. In general, normal paraffins require lower molecular weight and higher temperature for similar conversion. The dehydrogenation zone maintains a pressure as low as practicable, generally below 345 kPa (g) (50 psi (g)), consistent with plant limits to maximize chemical equilibrium benefits.

The extract stream may be mixed with diluent material before, during or after flowing into the dehydrogenation zone. The diluent material may be hydrogen, steam, methane, ethane, carbon dioxide, nitrogen, argon, or the like, or mixtures thereof. Hydrogen is the preferred diluent. In general, when hydrogen is used as a diluent, it is used in an amount sufficient so that the molar ratio of hydrogen to hydrocarbon is 0.1: 1 to 40: 1.

Substances degradable to water, such as alcohols, aldehydes, ethers or ketones, under water or dehydrogenation conditions, are continuously or intermittently added to the dehydrogenation section in an amount calculated on the basis of 1 / 200,000 ppm by weight of water in the extract stream. can do. When dehydrogenating paraffins with 2 to 30 carbon atoms, the best results can be obtained by adding 1 / 10,000 ppm by weight of water.

The dehydrogenated product stream is typically a mixture of branched monoolefins, including unreacted paraffins, straight chain (unbranched paraffins) olefins and slightly branched monoolefins. Typically 0-75 mol%, preferably 0-50 mol% of the olefins in the monoolefin-containing stream from the paraffin dehydrogenation process are linear (unbranched) olefins. The dehydrogenated product may comprise monoolefins having 8 to 28 carbon atoms in total and preferably monoolefins having less than 10 mol%, preferably less than 1 mol% quaternary carbon atoms.

The dehydrogenated product stream may comprise highly branched monoolefins or straight-chain (unbranched) olefins, but slightly branched monoolefins are preferred. The term "slightly branched monoolefin" as used herein refers to a monoolefin having a total number of 8 to 28 carbon atoms, of which three or four carbon atoms are primary carbon and no quaternary carbon atoms in the remaining carbon atoms. . Preferably, the slightly branched monoolefins have a total number of 8 to 15 carbon atoms, more preferably 10 to 15 carbon atoms.

Slightly branched monoolefins generally include aliphatic alkenes represented by the formula (p _i -alkyl _i ) _i -q-alkenes. Slightly branched monoolefins can be alpha monoolefins or vinylidene monoolefins, but are typically internal monoolefins. The term "alpha olefin" as disclosed herein means an olefin of the formula R-CH = CH ₂ . As used herein, the term "internal olefin" refers to a disubstituted internal olefin represented by the formula R-CH = CH-R; Trisubstituted internal olefins represented by the formula RC (R) = CH-R; And tetrasubstituted olefins represented by the formula RC (R) = C (R) -R. Disubstituted internal olefins include beta internal olefins represented by the formula R-CH = CH-CH ₃ . The term "vinylidene olefin" as used herein refers to an olefin having the formula RC (R) = CH ₂ . Slightly branched suitable monoolefins include octene, nonene, decene, undecene, dodecene, tridecene, tetradecene, pentadecene, hexadecene, heptadecene, octadecene, nonadecene, aicosene, henacene, docosene , Tricosene, tetracosene, pentacose, hexacosene, heptacosene and octacosene.

In the case of slightly branched monoolefins, the alkyl group branch (s) of the slightly branched monoolefins are generally selected from methyl, ethyl and propyl groups, with shorter normal branches being preferred. For all slightly branched monoolefins that pass through the alkylation section, preferably slightly branched monoolefins have only one alkyl group branch, but it is also possible to have two alkyl group branches. Slightly branched monoolefins comprising two alkyl branch or four primary carbon atoms generally comprise less than 30 mol%, preferably less than 15 mol% of the totally slightly branched monoolefin passing through the alkylation section, The remainder of the slightly branched monoolefin passing through the alkylation section has one alkyl group branch. Monoolefins comprising two alkyl groups or four primary carbon atoms and one quaternary carbon atom constitute less than 10 mole percent, preferably less than 1 mole percent of the totally slightly branched monoolefin passing through the alkylation section. do. Slightly branched monoolefins with one alkyl branch and three primary carbon atoms make up at least 85 mole percent of all slightly branched monoolefins passing through the alkylation section. A slightly branched monoolefin with only one alkyl branch and the only alkyl branch is a methyl group is called monomethyl-alkene, which is a preferred component of the dehydrogenated product stream.

Although vinylidene monoolefins may be present in the dehydrogenated product stream, they are usually minor components and generally have a concentration of less than 0.5 mol%, more generally less than 0.1 mol% of the olefins in the dehydrogenated product stream.

The skeletal structure of monoolefins in a mixture comprising slightly branched monoolefins can be determined by assays known to those skilled in the gas chromatography art and need not be described in detail herein. Those skilled in the art can modify the apparatus and method disclosed in the literature previously mentioned by Schulz et al to have an injector with a hydrogenator insert tube to hydrogenate slightly branched monoolefins into slightly branched paraffins in the injector. The slightly branched paraffins are then isolated and isolated substantially using the apparatus and methods disclosed in Schulz et al. However, this apparatus and method do not determine the location of carbon-carbon double bonds in any monoolefin in the mixture.

In addition to the slightly branched monoolefins, other acyclic compounds can be introduced into the alkylation section via a dehydrogenated product stream. One of the advantages of the present invention is that despite the fact that streams containing slightly branched monoolefins also contain acyclic paraffins having the same number of carbon atoms as slightly branched monoolefins, they can pass directly into the alkaline reaction section. Is there. Thus, in the present invention, the paraffins do not have to be separated from the monoolefin before passing through the alkylation section. Other acyclic compounds include unbranched (straight chain) olefins and monoolefins. The unbranched (straight chain) olefins that can be charged generally have 8 to 28, preferably 8 to 15, more preferably 10 to 13 carbon atoms per molecule of paraffin. Unbranched olefins are alpha monoolefins, but are preferably internal monoolefins. When present in a dehydrogenated product stream comprising slightly branched monoolefins, the straight chain olefin content should be no greater than 75 mol% of the total monoolefins in the dehydrogenated product stream, but generally the total monoolefin in the dehydrogenated product stream Is less than 60 mol%.

Since there may be straight chain monoolefins in addition to the slightly branched monoolefins in the dehydrogenated product stream, the bulk dehydrogenated product stream averages up to three primary carbon atoms per monoolefin molecule in the dehydrogenated product stream, or 3 To 3.4. Depending on the relative proportions of the straight and slightly branched monoolefins, the sum of all monoolefins passing through the dehydrogenated product stream or alkylation zone can comprise from 2.25 to 3.4 primary carbon atoms per monoolefin molecule.

The straight and / or non-chain paraffins passing through the dehydrogenated product stream into the alkylation section generally have a total number of carbon atoms per paraffin molecule of 8 to 28, preferably 8 to 15 and more preferably 10 to 13. Non-chain paraffins in the dehydrogenated product stream may comprise slightly branched paraffins, and may also include paraffins having one or more quaternary carbon atoms. Such straight and non-chain paraffins are expected to act as diluents in the alkylation step and do not substantially inhibit the alkylation step. Monoolefin molecules composed of one or more quaternary carbon atoms are generally less than 10 mol%, preferably less than 5 mol%, more preferably 2 mol of the sum of all monoolefins passing through the dehydrogenated product stream or alkylation section. Less than%, most preferably less than 1 mol%.

In the alkylation section, monoolefins and phenyl compounds in the dehydrogenation product stream react. In general cases, monoolefins may be reacted with benzene or substituted derivatives of benzene, including toluene and ethylbenzene. For detergent alkylation, the preferred phenyl compound is benzene. Solid alkylation catalysts typically react with phenyl compounds and monoolefins.

It is believed that the only minimal skeletal isomerization of olefins occurs in the alkylation section. Minimal skeletal isomerization of monoolefins generally means that less than 25 mol%, preferably less than 10 mol% of the olefins, aliphatic alkyl chains and any reaction intermediates undergo skeletal isomerization. Thus, the slightly branched degree of the slightly branched monoolefin is the same as that slightly branched in the aliphatic alkyl chain in the phenyl-alkane product molecule, and the number of primary carbon atoms is substantially the same. Finally, the formation of the 1-phenyl-alkane product under alkylation conditions is not significant, but the number of primary carbon atoms in the phenyl-alkane product will be slightly less than the number of primary carbon atoms in the slightly branched monoolefin.

Alkylation of phenyl compounds with slightly branched monoolefins results in (m _i -alkyl _i ) _i -n-phenyl-alkanes, wherein the aliphatic alkyl group has 2, 3 or 4 primary carbon atoms per phenyl-alkane molecule Have Preferably, the aliphatic alkyl group has three primary carbon atoms per phenyl-alkane molecule, more preferably one of the three primary carbon atoms is present in a methyl group at one end of the aliphatic alkyl chain and the second Primary carbon atoms are present in the methyl group at the other end of the chain and third primary carbon atoms are present in a single methyl group branch attached to the chain. In general, 0 to 75 mole%, preferably 0 to 50 mole%, of the resulting (m _i -alkyl _i ) _i -n-phenyl-alkane may have two primary carbon atoms per phenyl-alkane molecule. . Typically, 25-100 mole% of the resulting (m _i -alkyl _i ) _i -n-phenyl-alkanes may have three primary carbon atoms per phenyl-alkane molecule. In general, 0-40 mole% of the resulting (m _i -alkyl _i ) _i -n-phenyl-alkanes may have four primary carbon atoms. Thus, (m-methyl) -n-phenyl-alkane having only one methyl group branch is preferred, referred to herein as monomethyl-phenyl-alkane. The number of primary, secondary and tertiary carbon atoms per product phenyl-alkane molecule is determined by distortionless enhancement by high resolution multipulse nuclear magnetic resonance (NMR) spectral editing and polarization transfer. polarization transfer, which is disclosed in a brochure entitled "High Resolution Multipulse NMR Spectrum Editing and DEPT" by Bruker Instruments, Inc., Billinga Manning Park, Massachusetts, USA.

Alkylation of phenyl compounds with monoolefins has a selectivity to 2-phenyl-alkanes generally between 40 and 100, preferably 60 to 100 and selectivity to internal quaternary phenyl-alkanes generally less than 10, preferably Is less than five.

Alkylation of phenyl compounds with monoolefins has a selectivity of less than 10, preferably less than 1, for phenyl-alkanes containing quaternary carbon atoms of non-quaternary compounds. Appropriate approximations of selectivity to such quaternary phenyl-alkanes can be obtained using the following equation.

[Equation 1]

Where

T = selectivity for quaternary carbons of non-quaternary compounds

C _QO = number of moles of monoolefin with quaternary carbon atoms entering the selective alkylation zone

C _O = number of moles of monoolefin entering the selective alkylation zone

The molar flow rates of the monoolefins entering the selective alkylation zone and modified devices and methods such as Schulz et al., Previously mentioned can be used to determine the C _QO and C _O values. Selectivity T can be estimated using the above equation if the probability that each monoolefin entering the selective alkylation zone has the same alkylation of the phenyl compound, regardless of whether the monoolefin has a quaternary carbon atom. As a first approximation, this condition is met if at least 40% by weight of the monoolefin entering the selective alkylation zone is a slightly branched monoolefin or normal monoolefin.

Alkylation of the phenyl compound with the monoolefin can be carried out by a batch method, but a continuous method is preferred. The alkylation catalyst can be used as packed bed or fluidized bed in upflow, downflow or horizontal flow mode. Dehydrogenated product streams and benzene comprising slightly branched monoolefins entering the alkylation zone typically have a molar ratio of total phenyl compound: monoolefins of 2.5: 1 to 50: 1, more typically 8: 1 to 35: 1 A portion of the dehydrogenation product stream can be fed to several separate points in the alkylation reaction zone, with the phenyl compound: monoolefin molar ratio in each zone exceeding 50: 1. However, the total benzene: olefin ratio used in the aforementioned variant of the invention is within the stated range. The total mixed feed is passed through the packed bed at a liquid hourly space velocity (LHSV) of 0.3 to 6 hr ⁻¹ . The alkylation conditions include temperatures in the range of 80 ° C. (176 ° F.) to 225 ° C. (437 ° F.). Preferably, the alkylation takes place at least partially in the liquid phase, preferably under the whole liquid phase or supercritical conditions. The required pressure depends essentially on the olefin, the phenyl compound and the temperature, but is usually 1379-6895 kPa (g) (200-1000 psi (g)), most commonly 2069-3448 kPa (g) (300-500 psi ( g)) range. Alkylation reactions generally leave very little unreacted olefins and are typically converted at least 98% based on monoolefins.

Any alkylation catalyst that satisfies the conversion, selectivity and activity conditions can be used. Preferred alkylation catalysts include zeolites comprising zeolite structure BEA, MOR, MTW, or NES. Such zeolites include mordenite, ZSM-4, ZSM-12, ZSM-20, opretite, ghellinith, beta, NU-87, and gotartite. These zeolite structure types, the term "zeolite structure type" and the term "isotype framework structure" are described in Atlas of Zeolite Structure Types , by WM Meier, et al., Published on behalf of the Structure Commission of the International Zeolite Association by Elsevier, Boston, Massachusetts, USA, Fourth Revised Edition, 1996, as used herein. Alkylation with NU-87 and NU-85, which are intergrowths of zeolites EU-1 and NU-87, is disclosed in US-A-5,041,402 and US-A-5,446,234, respectively. Gothardites having an isotype framework structure of NES zeolite structure are described in A. Alberti et al., In Eur. J. Mineral., 8, 69-75 (1996), and by E. Galli et al., In Eur. J. Mineral., 8, 687-693 (1996). Most preferably, the alkylation catalyst comprises mordenite.

Zeolites useful as alkylation catalysts in the present invention generally have at least 10% of the cationic moiety occupied by ions other than alkali or alkaline earth metals. Such other ions include aluminum, zinc, copper, aluminum and preferably ammonium, hydrogen, rare earth or combinations thereof. In a preferred embodiment, the zeolite is converted mainly to the hydrogen form by substituting hydrogen ions precursors (eg ammonium ions) which generally yield hydrogen form upon calcination in place of the ions present. This exchange is conveniently carried out by contacting the zeolite with an ammonium salt solution (eg ammonium chloride) using known ion exchange methods. In some embodiments, the substitution produces a zeolitic material in which hydrogen ions make up at least 50% of the cationic moiety. Although the hydrogen form of the zeolite successfully promotes the reaction, the zeolite may be present in part in alkali metal form.

Alumina extraction (dealuminization) and one or more metal components such as group IIIB (IUPAC 3), group IVB (IUPAC 4), group VIB (IUPAC 6), group VIIB (IUPAC 7), group VIII (IUPAC 8-10) , And various chemical treatments, including combinations with Group IIB (IUPAC 12) metals, can be performed on the zeolites. In some cases, the zeolite may be heat treated, such as steamed or calcined, in air, hydrogen or an inert gas (eg nitrogen or helium). Appropriate steaming is performed by treating the zeolite with an atmosphere comprising 5-100% steam at temperatures between 250 ° C. (482 ° F.) and 1000 ° C. (1832 ° F.) for 0.25-100 hours under pressures below subatmospheric to several hundred atmospheres. Contacting.

Matrix materials or binders that are resistant to the temperatures and other conditions used in the process may include zeolites. Suitable matrix materials include synthetic, natural and inorganic materials such as clay, silica and / or metal oxides. Natural clays for mixing with zeolites include montmorillonite and kaolins. In addition to the materials described above, the zeolites used in the present invention may be formed from porous matrix materials such as alumina, silica-alumina, silica-magnesia, silica-zirconia, silica-toria, silica-berilia, silica-titania and aluminum phosphate, as well as ternary materials. Combinations such as silica-alumina-toria, silica-alumina-zirconia, silica-alumina-magnesia, and silica-magnesia-zirconia. The relative proportions of the matrix material may vary, but the zeolite weight content is 1 to 99% by weight, typically 5 to 80% by weight, preferably 30 to 80% by weight, based on the mixed weight of the zeolite and the matrix material.

Zeolites in alkylation catalysts generally have a framework silica: alumina molar ratio of 5: 1 to 100: 1. Mordenite for use in alkylation generally has a framework silica: alumina molar ratio of 12: 1 to 90: 1, preferably 12: 1 to 25: 1. The term "framework silica: alumina molar ratio" means the molar ratio of SiO ₂ per Al ₂ O ₃ in the zeolite framework.

Zeolites prepared in the presence of organic cations may not have sufficient catalytic activity for alkylation. It is believed that the cause of insufficient catalytic activity is that organic cations in the forming liquid occupy free space in the crystal. Such catalysts can be activated by heating at 540 ° C. (1004 ° F.) for 1 hour under an inert atmosphere, ion exchange with ammonium salts, and calcining at 540 ° C. (1004 ° F.) in air. If the calcination temperature is higher than 540 ° C. (1004 ° F.), any ammonia may decompose on the catalyst.

In the alkylation reaction zone, an alkylation reaction effluent is produced, which enters the separation plant for recovery of the product and the recycleable feed compound. The alkylation reaction effluent is passed through a benzene column to produce an overhead stream containing benzene and a bottom stream containing phenyl-alkane products for recycling to the alkylation reaction zone. This bottoms stream is passed through a paraffin column to produce an overhead stream comprising unreacted paraffins and a bottoms stream comprising the product phenyl-alkanes and any high molecular weight byproduct hydrocarbons produced in the alkylation reaction zone. The paraffin column bottoms stream is passed through a rerun column to produce an overhead phenyl-alkane product stream containing MAB and a rerun column bottoms stream containing polymerized olefins and polyalkylated benzenes (heavy alkylates). Alternatively, a sufficiently low heavy alkylate content in the paraffin column bottoms stream eliminates the need for a retest column, and the paraffin column bottoms stream can be recovered as a net MAB stream and then sulfonated to produce MABS.

Several variations of the process are possible. Selective hydrogenation can saturate the diolefin with the desired monoolefin in the dehydrogenated product stream. This process can be formed during the catalytic dehydrogenation of paraffins and dehydrogenated product streams that can lead to deactivation of the catalyst in the alkylation zone, reduced selectivity to the desired phenyl-alkanes and accumulation at unacceptable concentrations. It is possible to selectively remove the harmful aromatic by-products contained in the. The selective removal zone can take aromatic by-products from extract streams, dehydrogenated product streams, paraffin columns, overhead liquid streams in the dehydrogenation section, or, if present, selective diolefin hydrogenation product streams.

This process allows separation of paraffins having an average weight of C _10-13 paraffins by adsorption to produce extractive paraffins having an average branching degree of 0.25-1.3 or 0.4-1.3 alkyl groups per paraffin molecule to form the desired MAB composition. have. These extract paraffins mainly comprise linear paraffins and monobranched paraffins, and the alkyl group branch on the aliphatic alkyl chain of the extract paraffin mainly contains small substituents such as methyl group branch, ethyl group branch or propyl group branch. The extract paraffins are dehydrogenated to form the corresponding monoolefins, and the phenyl compounds are alkylated to form phenyl-alkanes. The resulting phenyl-alkanes consist of at least 55% by weight of the phenyl-alkanes in which the phenyl-alkanes in which the phenyl groups are bonded at the 2- and / or 3-positions of the aliphatic alkyl groups and at least one quaternary carbon atom on the aliphatic alkyl group Phenyl-alkanes possessed by are characterized by constituting less than 20% of phenyl-alkanes.

Sulfonation of phenyl-alkanes prepared by the process of the present invention is described in Detergent Manufacture Including Zeolite Builders and Other New Materials, by Marshal Sittig, Noyes Data Corporation, Park Ridge, New Jersey, 1979, and in Volume 56 of "Surfactant Science "series, Marcel Dekker, Inc., New York, NY. 1996, including those known in the art, can be realized by contacting any known sulfonated system with a phenyl-alkane compound. The sulfonation of the phenyl-alkane compound forms a sulfonated product comprising phenyl-alkane sulfonic acid. After sulfonation, the sulfonated product is neutralized with any suitable alkali (eg, sodium, potassium, ammonium, magnesium, calcium and substituted ammonium alkalis and mixtures thereof) to form a neutralization product comprising phenyl-alkane sulfonate. .

In another embodiment of the invention, the invention relates to the use of a MAB composition as a lubricant produced by the processes disclosed herein. These phenyl-alkanes are believed to have the properties of viscosity, temperature-dependence of viscosity and density which make them advantageous for use as petroleum lubricants. The use of phenyl-alkanes as lubricants is described, for example, in lubricant descriptions and references cited for their use. R. Booser in Kirk-Othmer Encyclopedia of Chemical Technoloay, Fourth Edition, Volume 15, John Wiley and Sons, New York, New York, USA, 1995, pp. 463-517.

In another embodiment, the present invention relates to the use of a MABS composition produced by the process disclosed herein as a lubricant additive. Phenyl-alkane sulfonates which are in the form of common or basic salts of phenyl-alkane sulfonic acid and formed as disclosed herein are believed to have the ability to reduce or inhibit deposits in engines operating at high temperatures. The term "common salt" of an acid means a salt comprising a stoichiometric metal necessary for the neutralization of the acidic group (s) present, and the term "basic salt" means a salt comprising at least a metal necessary for the neutralization reaction. Means. It is believed that excess metal in the form of basic salts can neutralize oil oxidative combustion products and "blow-by" fuel combustion products. Phenyl-alkane sulfonates and their lubricant additives, in particular their use as detergents, are described, for example, in Booser, supra, in Lubricant Additives, by CV Smalheer and RK Smith, The Lezius-Hiles Co., Cleveland, Ohio, USA, 1967, pp. 2-3]; RW Watson and TF McDonnell, Jr., Additives-The Right Stuff for Automotive Engine Oils, Fuels and Lubricants Technology: An Overview SP-603 , Society of Automotive Engineers, Warrendale, Pennsylvania, USA, October 1984, pp. 17-28.

The figure shows a preferred arrangement for the integral separation-dehydrogenation-alkylation process of the present invention. The following description of the drawings is not intended to exclude other arrangements for the process flows of the present invention and is not intended to limit the invention as disclosed in the claims.

Referring to the drawings below, line 12 shows a feed mixture comprising a mixture of C _10-13 , including slightly branched paraffins, more highly branched paraffins, and normal (unbranched) paraffins, normal paraffins and / or Cycloparaffin and / or isooctane are introduced into the adsorption separation section 20 using the desorbent. Line 20 passes a raffinate stream comprising more highly branched paraffins and cycloparaffins or isooctane from the adsorptive separation zone 20 to the raffinate column 30. Under the conditions of the raffinate column 30, an overhead stream 32 comprising desorbent material and a bottom stream of line 28 comprising more highly branched paraffins are formed. Line 34 passes an extract stream comprising slightly branched paraffin, normal paraffin and desorbent material from adsorptive separation zone 20 to extraction column 40. Adsorbent material is withdrawn from extraction column 40 to line 46. The overhead stream of the combined lines 32 and 46 recycles the desorbent through the line 44. Extraction column 40 also produces a bottoms stream comprising slightly branched paraffins and normal paraffins in line 52.

Line 52 mixes the bottom stream from extraction column 40 and recycled hydrogen from line 82 to form a mixture of paraffins and hydrogen flowing through line 56. Indirect heat exchanger 58 heats the contents of line 56, which passes through line 62 to ignited heater 60. Line 64 conveys the heated stream to dehydrogenation reactor 70. The dehydrogenation reactor 70 is brought into contact with the dehydrogenation catalyst and paraffin under conditions that significantly convert paraffins to the corresponding olefins. Lines 66 and 68 show a dehydrogenation reactor effluent stream comprising a mixture of monoolefins, diolefins, C ₉ -minus hydrocarbons and aromatic hydrocarbons, including hydrogen, paraffins, slightly branched monoolefins, and heat exchangers 58 and 72. Pass through in series) to cool. This cooling condenses substantially all C ₄ -plus hydrocarbons into the liquid stream and separates the liquid stream from the remaining hydrogen concentrated vapors. Line 74 passes the dehydrogenation reactor effluent through the distillate-separation vessel 80 where the hydrogen concentrated vapor phase stream exiting through line 76 and the dehydrogenation product stream exiting through line 84 Separated by. Line 76 feeds recycle hydrogen to line 82 and recovers the net hydrogen product stream in line 78.

Line 84 containing normal paraffins, slightly branched paraffins, normal monoolefins, slightly branched monoolefins, C ₉ -minus hydrocarbons, diolefins, aromatic by-products and some dissolved hydrogen, is provided at the bottom of separation vessel 80. Pass to the selective hydrogenation reactor 86. In the selective hydrogenation reactor 86, a dehydrogenated product stream is contacted with a selective hydrogenation catalyst under conditions which convert a significant amount of diolefin to the corresponding monoolefin, and further for hydrogen and / or conversion dissolved in the dehydrogenated product stream. The constituent hydrogen of (not shown) is used. Line 88 is a stripping column of a selective hydrogenation reactor effluent stream comprising a mixture of hydrogen, normal paraffin, slightly branched paraffin, normal monoolefin, slightly branched monoolefin, C ₉ minus hydrocarbon and aromatic byproduct hydrocarbon. 90). Stripping column 90 recovers a net overhead stream comprising C ₉ -minus hydrocarbons produced in the dehydrogenation reactor as a by-product to line 94 and any remaining dissolved hydrogen is net over separated from the process. Separate from the final product concentrated in the head stream.

Line 96 passes the remaining C ₁₀ -plus hydrocarbons from stripping column 90 into the aromatic removal zone 100 where the adsorbent and effluent contact to remove aromatic by-products. Line 98 comprises a mixture of normal paraffins, slightly branched paraffins, normal monoolefins and slightly branched monoolefins, and the aromatics removal zone for the effluent with a significantly reduced concentration of aromatic by-products as compared to the stripping effluent stream. Transfer from (100). After adding benzene through line 112, line 102 passes the mixture through an alkylation reactor 104, wherein the mixture is contacted with an alkylation catalyst under alkylation promoting conditions to produce phenyl-alkanes.

Line 106 conveys the alkylation reactor effluent stream to benzene fractionation column 110. This stream contains benzene, normal paraffin, slightly branched paraffin and MAB. Phenyl-alkanes are characterized by MABs, in addition to the phenyl moiety, having one or two primary carbon atoms, or two, three or four primary carbon atoms and one aliphatic alkyl moiety except for quaternary compounds. Column 110 separates the effluent into an overheads stream and a bottoms stream comprising benzene and possibly light gases. Line 107 combines the overhead stream of line 107 with constituent benzene from line 109 into line 108 and passes the combined stream to separator drum 120. Line 114 removes any non-condensed light gas from drum 120, while line 116 feeds condensed liquid as reflux to column 110 via line 118 and recycles benzene to line Supply to 112. Line 122 transfers the remaining alkylation effluent stream from column 110 to paraffin column 124, from the paraffin column through line 48, comprising a mixture of paraffins and generally less than 0.3 wt% monoolefins. To exhaust the overhead stream. Line 126 transfers the paraffin column bottoms stream containing phenyl-alkane and heavy alkylate by-products to redo column 130 where the bottom stream 132 containing heavy alkylates and the phenyl-alkane compound are contained. The overhead alkylate product stream 128 separates the paraffin column bottoms stream. Sulfonation of the phenyl-alkane compound in the overhead alkylate product stream 128 produces phenyl-alkane sulfonic acid, which may neutralize it.

Example 1

The "pulse test" procedure involves testing the adsorbent and desorbent material for a particular feed mixture to determine the adsorption capacity, selectivity, partitioning capacity and exchange rate of the adsorbent. The basic pulse test apparatus consists of a tubular adsorbent chamber of about 70 cc volume having an inlet and an outlet at opposite ends of the chamber. Inside the chamber there is a temperature regulating means and the pressure regulating device maintains the chamber at a constant predetermined pressure. Quantitative and qualitative analysis devices such as refractometers, polarimeters and chromatography are added to the outlet line of the chamber to quantitatively detect and / or qualitatively measure one or more components of the effluent stream exiting the adsorbent chamber. The desorbent material is passed through the adsorbent chamber to fill the adsorbent in equilibrium with the particular desorbent material, injecting a feed mixture pulse, sometimes diluted in the desorbent, for at least 1 minute, and then feeding the feed mixture components to liquid-solid chromatography The pulse test is initiated by restarting the desorbent flow which flows out as a graphics operation. The effluent may be analyzed on the stream and / or the effluent fractions are collected and later analyzed separately to plot the trace of the envelope of the corresponding component peak as component concentration against the amount of effluent.

From the information derived from the pulse test, the adsorbent / desorbent system performance is usually determined by the retention volume for the extract or raffinate component, the selectivity for one component to another, the stage time, the splitability between the components, It can be graded as the rate of desorption of the extract component by the desorbent. The distance between the center of the peak envelope of the extract or raffinate component and the peak envelope of the trace component or some other known reference point is the extract or the volume of the desorbent pumped during the interval of time corresponding to the distance between the peak envelopes (cm ³ ). Determine the retention volume of the raffinate.

Table 1 presents the results and parameters of a small “pulse test” conducted to evaluate various desorbents and conditions for several feed mixtures. The material labeled Raffinate A and B is the raffinate stream of a commercial adsorbent separation unit that recovers normal paraffins from the C _10-14 hydrocarbon fraction. The desorbent column in Table 1 represents the volume percentage of each desorbent component shown in the footnote.

Running number Feed mixture Temperature (℃) Desorbent ^* 9577-77 Raffinate A 150 50 C5 / 50 N6 9577-85 Raffinate A 100 50 C5 / 50 N6 9937-01 Raffinate A 150 100 C6 9937-06 Raffinate A 150 70 C6 / 30 N6 9937-17 Raffinate A 150 50 C6 / 50 N6 9937-25 Raffinate B 150 50 C6 / 50 N6 9953-06 Kerosene 150 50 C6 / 50 N6 * C ₅ means cyclopentane.
C ₆ means cyclohexane.
N ₆ means n-hexane.

All tests used an adsorbent consisting of 80% silicalite and 20% silica binder and a chromatography column with an adsorbent volume of 70 ml. The flow rate through the column was 1.21 cc / min.

Taking into account the very large number of different compounds in the feed mixture pulses and the inherent limitations of a simple pulse test procedure, fractions of the effluent were collected every 2 minutes and each fraction analyzed to determine separation effectiveness. The initial fraction contained a high concentration of desorbent, but was followed by a fraction containing a higher concentration of more branched non-normal hydrocarbons. Desired acyclic hydrocarbons (ie monomethyl hydrocarbons) with only three primary carbon atoms tend to concentrate in the fraction collected at the end of the pulse. Table 2 shows the concentrations (% by weight) of acyclic paraffins (ie monomethyl paraffins) containing only three primary carbon atoms present in several different fractions of run number 9937-06.

Fraction number Acrylic paraffin containing only 1 primary carbon atom (%) 18 34 19 48 20 60 22 55 24 60 26 77 28 77 32 79 38 96

Run numbers 9937-06 combined the collected liquid as fractions 19-100. As a result of the analysis, it was found that the compound liquids having different structures included in weight percent as shown in Table 3 based on that the combined liquid contained no desorbent.

Acyclic paraffin with only three primary carbon atoms (monomethyl branched) 64% Acyclic paraffin with only 4 primary carbon atoms (dimethyl branched) 2.7% Acyclic paraffins with only two primary carbon atoms (normal paraffins) 4.6% Aromatic 4.1% Naphthenes 13.9% Unknown 10.7%

In run numbers 9937-17 the collected liquids as fractions 23 to 50 were combined. The analysis found that the liquid contained compound types with different structures in weight percent as shown in Table 4.

Acyclic paraffin with only three primary carbon atoms (monomethyl branched) 77% Acyclic paraffin with only 4 primary carbon atoms (dimethyl branched) 0.1% Acyclic paraffins with only two primary carbon atoms (normal paraffins) 9.6% Aromatic 4.1% Naphthenes 3.8% Unknown 4.8%

Sample analysis formed by combining the liquids obtained from fractions 23 to 48 of run 9953-6 showed 67% of acyclic paraffins (ie monomethyl branched compounds) having only three primary carbon atoms and only two primary carbon atoms. It was found to have acyclic paraffin having 9.3% (ie, normal paraffin).

In comparing this data with the performance desired for industrial separation, it is necessary to recognize that optimizing the adsorbent composition, the desorbent composition and the working rod will yield better selectivity. The simulated mobile phase (SMB) method or good batch separation method is used to improve process performance.

Example 2

In this example, a pulse test procedure was performed using a pre-pulse of C ₈ isoparaffin on a representative mixture of pure components of C ₁₀ . In the test, a feed mixture comprising 3,3,5-trimethylheptane, 2,6-dimethyloctane, 2-methylnonane, n-decane, and the same amount of 1,3,5-trimethylbenzene was tested at a temperature of 120 ° C (248). In a 70 cc volume pulse test column maintained at < RTI ID = 0.0 > The flow rate through the column was 1.1 cc / min. The test used a 70/30% by volume mixture of n-heptane and isooctane as silicalite adsorbent and desorbent. In the test, 40 ml of isooctane pre-pulse was placed in the test loop immediately before feed mixture injection.

2 graphically shows the results of plotting the relative concentrations of components over time as measured by the volume of effluent collected. 2 shows useful separation between monomethyl paraffin and normal paraffin on the one hand and useful separation of dimethyl paraffin and trimethyl paraffin on the other hand. The use of pre-pulse is thought to improve the separation of the monomethyl paraffin band in the effluent, but in the absence of prepulse the presence of isooctane in the desorbent results in the formation of a useful separation band of monomethyl paraffin.

Example 3

An olefin stream was used.                 

Composition of the Olefin Stream Olefin component Content (% by weight) Hard ¹ 0.64 Straight chain olefins ² 30.11 6-methyl undecene 7.66 5-methyl undecene 15.33 4-methyl undecene 11.82 3-methyl undecene 12.95 2-methyl undecene 8.87 Other Alkyl Olefin ³ 9.05 Heavy ⁴ 3.53 Sum 100 ^One hard component includes olefins having up to 12 carbon atoms.
² straight chain olefins include C ₁₂ linear olefins.
³ Other alkyl olefins include dimethyl, trimethyl and other C ₁₂ olefins.
^{The four} heavy components include C ₁₂ olefin dimers and trimers.

A mixture of benzene streams and benzenes comprising a blend of monomethyl C ₁₂ olefins and having the compositions shown in Table 5 forms a combined stream consisting of 93.3 wt% benzene and 6.7 wt% olefins stream, which comprises 30: of benzene per olefin: Corresponds to 1 molar ratio. Into a cylindrical reactor having an internal diameter of 0.875 in (22.2 mm) was charged 75 cc (53.0 g) of a mordenite-alumina extruded catalyst prepared from a hydrogen type of mordenite having SiO ₂ / Al ₂ O ₃ of 18.

The combined streams were passed through a reactor and contacted the extrudate at a LHSV of 2.0 hr ⁻¹ , a total pressure of 500 psi (g) (3447 kPa (g)) and a reactor inlet temperature of 125 ° C. (257 ° F.). The reactor was lined out for 24 hours under these conditions and then the optional liquid product was collected for the next 6 hours.

Selective liquid products were analyzed by ¹³ C nuclear magnetic resonance (NMR) to determine selectivity for 2-phenyl-alkanes and final quaternary phenyl-alkanes. NMR assays typically dilute 0.5 g of a sample of phenyl-alkane mixture to 1.5 g with anhydrous deuterated chloroform, and 0.3 ml aliquots of the diluted phenyl-alkane mixture in a 5 mm NMR tube were diluted with 0.1 M chromium in deuterated chloroform. III) Mix with 0.3 ml of acetylacetonate, add a small amount of tetramethylsilane (TMS) to the mixture as a 0.0 ppm chemical transfer reference, available from Bruker Instruments, Inc., Billerica, Mass. In a Bruker ACP-300 FT-NMR spectrometer, 65000 data points were collected by conducting carbon spectra under magnetic field strength 7.05 Tesla or 75.469 MHz in a 5 mm QNP probe with a sweep width of 22727 Hz (301.1 ppm). Quantitative carbon spectra are obtained using gated on-acquisition ¹ H separation (inverse gated decoupling). The quantitative ¹³ C spectrum is an 18H separator power supply with 105 μsec (90 °) pulse width, using 7.99 μsec (90 °) pulses, 1.442 sec acquisition time, 5 second delay between pulses, and compound pulse separation (CPD). And run at least 2880 scans. The number of scans depends on whether benzene is stripped from the liquid product before taking the 0.5 g sample mentioned above. Data processing is performed using Bruker PC software WINNMR-1D, version 6.0 and data scanning. In the course of data processing, 1 Hz line widening is applied to the data. Integrate specific peaks in the range of 152 to 142 ppm. Table 6 shows ¹³ C NMR peaks showing the chemical shift of benzyl carbon in the phenyl-alkane isomer. The term "benzyl-based carbon" means carbon in the phenyl group ring bonded to an aliphatic alkyl group.

¹³ C NMR peak identification Chemical shift of benzyl carbon (ppm) Phenyl-alkane Isomers Quaternary Compound ¹ 149.6 2-methyl-2-phenyl end 148.3 4-methyl-2-phenyl NQ m-methyl-m-phenyl, m> 3 inside 148.0 5-methyl-2-phenyl NQ
147.8 m-methyl-2-phenyl, m> 5 NQ 5-methyl-2-phenyl NQ 2-phenyl (straight chain) NQ 3-methyl-3-phenyl inside 147.6 4-methyl-2-phenyl NQ 147.2 3-methyl-2-phenyl NQ 146.6 3-methyl-2-phenyl NQ 146.2-146.3 m-methyl-4-phenyl, m ≠ 4 NQ 145.9-146.2 m-methyl-3-phenyl, m> 5 NQ 145.9 3-phenyl (straight chain) NQ ¹ NQ = non-quaternary compound

Peaks at 148.3 ppm are identified with 4-methyl-2-phenyl-alkanes and m-methyl-m-phenyl-alkanes (m> 3). However, if 1% or more of m-methyl-m-phenyl-alkane (m> 3) is present, a characteristic peak appears in the 0.03 ppm upfield of the peak for 4-methyl-2-phenyl-alkane. The peak at 147.8 ppm is identified as 2-phenyl-alkane as shown in Table 6, and interference with 3-methyl-3-phenyl-alkane is possible.

Terminal quaternary phenyl-alkane selectivity is calculated by dividing the peak integration at 149.6 ppm by the sum of the integration of all peaks shown in Table 6 and then multiplying by 100. 2-phenyl-alkane selectivity can be estimated when the amount of internal quaternary phenyl-alkanes contributing to peaks at 148.3 ppm and 147.8 ppm, as determined below by gas chromatography / mass spectrometry, is less than 2%. As a first approximation, the sum of the (each) integrals of the 4-phenyl-alkanes and 3-phenyl-alkanes peaks at 146.2-146.3 ppm and 145.9-146.2 ppm is the sum of the integrals of all peaks of 145.9-149.6 ppm This condition is satisfied if it is small compared to and the terminal quaternary phenyl-alkane selectivity is less than 10. In such cases, 2-phenyl-alkane selectivity is calculated by dividing the sum of the integrals of the 149.6-146.6 ppm peaks by the sum of the integrals of all the peaks shown in Table 6 and then multiplying by 100.

Analysis of the selective liquid product with gas chromatography / mass spectroscopy determines the selectivity for internal quaternary phenyl-alkanes. Gas chromatography / mass spectrometry methods typically use HP 5890 Series II Gas Chromatography (GC) with HP 7673 autosampler and HP 5972 mass spectroscopy (used with HP ChemStations to control data acquisition and analysis). MS) The liquid product is analyzed by a detector (these instruments are available from Hewlett Packard Company, Palo Alto, Calif.). GC has a 30 m × 0.25 mm DB1HT (df = 0.1 μm) column or equivalent equivalent obtained from J & W Scientific Incorporated, Folsom, Blue Rayvin Road 91, California. Helium carrier gas at 15 psi (g) (103 kPa (g)) and 70 ° C. (158 ° F.) is passed in constant pressure mode while maintaining the injection temperature at 275 ° C. (527 ° F.). The transport line and MS source temperature were maintained at 250 ° C. (482 ° F.). 70 ° C (158 ° F) for 1 minute, 180 ° C (356 ° F) at 1 ° C (1.8 ° F) per minute, 275 ° C (527 ° F) at 10 ° C (18 ° F) per minute, 275 for 5 minutes Use an oven temperature program maintained at 527 ° F. The HP ChemStation software controls the MS with software configured for standard spectrum auto tuning. The MS detector scans from 50 to 550 Da with a threshold of 50.

Standard addition methods are used to determine the concentration of internal quaternary phenyl-alkanes in the selective liquid product (ie, quantify the selective liquid product). B. Samples and Standards. Chapter 7 of W. Woodget et al., Published on behalf of ACOL, London by John Wiley and Sons, New York, in 1987 describes the background of the method.

First, a mother liquor of internal quaternary phenyl-alkanes is prepared and quantified by alkylation of benzene with monomethyl alkenes using a non-selective catalyst such as aluminum chloride. The mother liquor comprising the non-selective liquid product of these alkylations comprises a blend of internal quaternary phenyl-alkanes. Standard GC methods identify the maximum peaks corresponding to the mother liquor and determine the concentration of internal quaternary phenyl-alkanes in the mother liquor (ie, quantify the mother liquor) using a flame ionization detector (FID). The residence time of the peak of the internal quaternary phenyl-alkanes decreases as the index m of the formula m-methyl-m-phenyl-alkanes increases and as the number of carbon atoms of the aliphatic alkyl groups of the internal quaternary phenyl-alkanes decreases. . The concentration of each internal quaternary phenyl-alkane is calculated by dividing the peak area of the internal phenyl-alkane by the sum of the areas of all peaks.

Then, a portion of the aliquot of the mother liquor is diluted with dichloromethane (methylene chloride) to obtain a nominal concentration of 100 wppm of the desired specific internal quaternary phenyl-alkane (e.g. 3-methyl-3-phenyl-decane) to yield internal quaternary phenyl Prepare a spiking solution of alkanes. The concentration of any other particular internal quaternary phenyl-alkanes in the spiking solution may be at least 100 wppm or less, depending on the concentration of internal quaternary phenyl-alkanes in the mother liquor.

Third, a sample solution is prepared by adding 0.05 g of a portion of an optional liquid product to a 10 ml volumetric flask and then diluting the contents with chloromethane up to the 10 ml volume.

Fourth, a portion of 0.05 g aliquot of the optional liquid product is added to a 10 ml volumetric flask and the resulting solution is prepared by diluting the contents with a spiking solution to the 10 ml line to dilute the contents.

The sample solution and the production solution are analyzed by GC / MS under the conditions described above. Table 7 shows the ions extracted from the full MS scan using HP ChemStation software, plots and integration results thereof. HP ChemStation software measures the individual extracted ion peak areas corresponding to the internal quaternary compounds shown in Table 7.

Ratio of mass to charge of ions to extracted ion peak Internal quaternary phenyl-alkanes Number of carbon atoms in aliphatic alkyl groups of internal quaternary phenyl-alkanes Ratio of mass to charge of two extracted ions corresponding to internal quaternary phenyl-alkanes (m / z) 3-methyl-3-phenyl 11 133 and 203 12 133 and 217 13 133 and 231 4-methyl-4-phenyl 11 147 and 189 12 147 and 203 13 147 and 217 5-methyl-5-phenyl 11 161 and 175 12 161 and 189 13 161 and 203

The concentration of each internal quaternary phenyl-alkane in Table 7 is calculated using the following equation.

[Equation 2]

Where

C = concentration of the internal quaternary phenyl-alkanes in the sample solution, weight percent

S = concentration of internal quaternary phenyl-alkanes in spiking liquid, wt%

A ₁ = peak area, area unit of the internal quaternary phenyl-alkanes in the sample solution

A ₂ = peak area of internal quaternary phenyl-alkanes in the product solution, area unit

Using consistent units, the concentration of each internal quaternary phenyl-alkane in the optional liquid product is calculated from the concentration of the internal quaternary phenyl-alkanes in the sample liquid to account for the dilution effect of dichloromethane in the sample liquid. In this way, the concentration in the selective liquid product of each of the internal quaternary phenyl-alkanes of Table 7 is estimated. The total concentration of internal quaternary phenyl-alkanes, ie C _IQPA , in the optional liquid product is calculated by summing the individual concentrations of each of the internal quaternary phenyl-alkanes in Table 7.

Optional liquid products may contain internal quaternary phenyl-alkanes other than those shown in Table 7, such as m-methyl-m-phenyl-alkanes, where m > 5, depending on the number of carbon atoms in the aliphatic alkyl group of the phenyl-alkanes It may include. Using the conditions of this example and the C ₁₂ olefin stream, the concentrations of other internal quaternary phenyl-alkanes are also considered to be relatively low compared to the internal quaternary phenyl-alkanes shown in Table 7. For this example, the total concentration of internal quaternary phenyl-alkanes, C _IQPA , in the optional liquid product is calculated by summing only the individual concentrations of each of the internal quaternary phenyl-alkanes _shown in Table 7. However, when the olefinic stream consists of olefins having up to 28 carbon atoms, the total concentration of internal quaternary phenyl-alkanes in the optional liquid product, C _IQPA is m-methyl-m-phenyl-alkane, where m is 3 The individual concentrations of ˜13). More generally, if the olefin stream comprises olefins having x carbon atoms, the total concentration of the internal quaternary phenyl-alkanes in the optional liquid product, C _IQPA is m-methyl-m-phenyl-alkanes, where m is 3 Calculate by summing the individual concentrations of ˜x / 2). One or more peaks with a ratio of the mass to charge (m / z) of the extracted ions corresponding to each internal quaternary phenyl-alkane can be identified without undue experimentation, thus determining the concentration of all internal quaternary phenyl-alkanes Then, the _sum is obtained C _IQPA .

Selectivity to the internal quaternary phenyl-alkanes in the optional liquid product is calculated using Equation 3 below.

&Quot; (3) "

here,

Q = selectivity for internal quaternary phenyl-alkanes

C _IQPA = concentration of internal quaternary phenyl-alkanes in the selective liquid product, wt%

C _MAB = concentration of modified alkylbenzene in selective liquid product, weight percent

The concentration C _MAB of the modified alkylbenzene in the selective liquid product is determined using gas chromatography to find the concentration of impurities in the selective liquid product. In the determination of C _MAB , “impurity” means a component of the selective liquid product that is outside the specific retention time range used in the gas chromatography method. "Impurities" generally include benzene, some dialkylbenzenes, olefins, paraffins, and the like.

Gas chromatography determines the amount of impurities from the selective liquid product. The amount of impurities in the optional liquid product can be determined using an equivalent apparatus that produces a result that is different but equivalent to that presented below, equivalent sample preparation, and equivalent GC parameters.

Device:

Hewlett Packard Gas Chromatograph HP 5890 Series II with split / splitless injector and flame ionization detector (FID)

J & W Scientific capillary column DB-1 HT, 30 m long, 0.25 mm inner diameter, 0.1 μm membrane thickness, catalog # 1221131.

Restek Red lite Septa 11 mm, catalog # 22306. (available from Restek Corporation, Bellefont Benner Circle 110, Pennsylvania, USA).

Restek 4 mm Gooseneck entrance with carbofrit, catalog number 20799-209.5.

Inlet liner O-ring for Hewlett Packard, catalog number 5180-4182.

J. T. Baker HPLC grade methylene chloride, catalog number 9315-33, or equivalent (commercially available from J. T. Baker Co., Red School Lane 222, Pilsburg, NJ).

2 ml gas chromatography autosampler bottle or equivalent thereof with a crimp tower.

Sample preparation:

Samples 4-5 mg are weighed into a 2 ml GC autosampler bottle.

1 ml methylene chloride is added to the GC bottle; Using the crimper tool HP part number 8710-0979 (available from Hewlett Packard Company), an 11 mm crimp bottle was used with HP part number 5181-1210 (available from Hewlett Packard Company) with a Teflon-tipped closure Seal; Mix well.

The sample is now ready to be injected into the GC.

GC parameters:

Carrier gas: hydrogen

Column head pressure: 9 psi

Flow rate: column flow rate 1 ml / min; Split aeration 3 ml / min; Diaphragm purge 1 ml / min                 

Injection: HP 7673 autosampler, 10 μl syringe, 1 μl injection.

Injection temperature: 350 ° C. (662 ° F.)

Detector temperature: 400 ° C. (752 ° F.)

Oven temperature program: initial hold at 70 ° C. (158 ° F.) for 1 minute; Heating at a rate of 1 ° C. per minute (1.8 ° F. per minute); Hold at 180 ° C. (356 ° F.) for 10 minutes.

This gas chromatographic method generally requires two freshly distilled standards that contain 2-phenyl-alkanes and are at least 98 mol% pure. A "hard standard" of 2-phenyl-alkanes has at least one carbon atom of an aliphatic alkyl group than the olefins of the olefinic stream fed to the alkylation zone with the minimum number of carbon atoms. A “heavy standard” of a 2-phenyl-alkane standard has at least one carbon atom of an aliphatic alkyl group than the olefins of the olefinic stream fed to the alkylation zone with the maximum number of carbon atoms. For example, if the olefins in the olefins stream fed to the alkylation zone have 10 to 14 carbon atoms, suitable standards include 2-phenyl-octane as light standard and 2-phenyl-pentadecane as heavy standard. do.

Gas chromatography methods using the conditions set forth above determine the residence time of each standard and the residence time of the two standards that define the range of residence time. An aliquot of the selective liquid product is then analyzed by gas chromatography using these conditions. If at least 90% of the total GC area is within the residence time range, the impurities in the selective liquid product are considered not to be at least 10% by weight of the selective liquid product, and for the purpose of calculating the internal quaternary phenyl-alkanes, C _MAB is 100 Assume it is weight percent.

If the percentage of total GC area within the retention time range is not greater than 90%, the impurities in the selective liquid product are considered to be at least 10% by weight of the selective liquid product. In this case, in order to measure C _MAB , 2200-2300 g of optional liquid product was added to a 5 L three-necked round bottom flask equipped with a 24/40 connection and containing a magnetic stir bar and several boiling pieces. The impurities are distilled off from the liquid product. Place a 9-1 / 2 inch (24.1 cm) length Vigreux condenser with 24/40 connections at the center of the flask and attach a water cooled condenser with a calibrated thermometer to the top of the Vigreux. Attach the flask containing the vacuum to the condenser end. A stopper occupies one arm of the flask and a graduated thermometer extends from the other arm. Aluminum foil packaging surrounds the flask and Vigreux. The vacuum line applies a vacuum to the receiving plaques when stirring the selective liquid product in the flask and heats the selective liquid product with an electric heating mantle when the maximum vacuum is reached (at least 25.4 mmHg or less by gauge).

After initiation of heating, "fraction A" is first collected at a range from 25 ° C. (77 ° F.) to the hard standard boiling point temperature under pressure on the Vigreux top, as measured by a graduated thermometer at the top of Vigreux. Collect "fraction B" in the range from the hard standard boiling point temperature to the heavy standard boiling point temperature measured by a calibrated thermometer at the top of the Vigreux for the pressure at the top of the Vigreux. The low boiling point fraction A and the high boiling pot residues are decanted. Fraction B comprises the desired modified alkylbenzene and weighs it. Suitable temperatures for harvesting fractions A and B are described in Samuel B. Lippincott and Margaret M. Lyman, Industrial and Engineering Chemistry, Vol. 38, in 1946, page 320-]. See Lippincott et al.

The aliquot samples of Fraction B are then analyzed by gas chromatography using the above conditions. If at least 90% of the total GC area of fraction B is within the residence time range, the impurities in fraction B are considered to be less than 10% by weight of the selective liquid product and are collected for the purpose of calculating the selectivity to the internal quaternary phenyl-alkanes. The C _MAB is calculated by dividing the weight of the fraction B thus obtained by the weight of the aliquot portion of the optional liquid product charged to the 5 L flask in the distillation. If the percentage of total GC area to fraction B in the retention time range is less than 90%, the impurities in fraction B are considered to be greater than 10% by weight of fraction B, and the impurities are removed again using the above distillation method. The low boiling point fraction C and the pot residue are separated from fraction D containing modified alkylbenzene. Fraction D is recovered, weighed and analyzed by gas chromatography to determine whether the total GC area for fractions within the retention time range meets the same 90% criteria. If so, calculate the C _MAB using the procedure disclosed previously. Otherwise, distillation and gas chromatography are repeated for fraction D.

The distillation and gas chromatography methods disclosed above may be repeated until the fraction containing the desired modified alkylbenzen and having less than 10% by weight impurities is collected. However, for further testing by these methods a sufficient amount of material must remain after each distillation. Once C _MAB is measured, the selectivity Q for the internal quaternary phenyl-alkanes is calculated using Equation 3 above.

The results of these analyzes are shown in Table 8.

2-phenyl-alkane selectivity Terminal quaternary phenyl-alkane selectivity Internal Quaternary Phenyl-alkanes Selectivity 82.0% 6.98% 1.9%

In the absence of shape selectivity, most 2-methyl undecenes are expected to form 2-methyl-2-phenyl undecane (ie, terminal quaternary compounds). Similarly, most 6-methyl undecenes, 5-methyl undecenes, 4-methyl undecenes and 3-methyl undecenes are also expected to form internal quaternary compounds. Straight chain olefins are expected to yield a statistical distribution of 2-phenyl-dodecane, 3-phenyl-dodecane, 4-phenyl-dodecane, 5-phenyl-dodecane and 6-phenyl-dodecane. Thus, when light, heavy and other alkyl olefins shown in Table 5 are excluded from the calculation, the 2-phenyl-alkane selectivity is 17 or less and the internal quaternary phenyl-alkane selectivity is close to 55. From Table 8, 2-phenyl-alkane selectivity is significantly higher than expected in the absence of shape selectivity, and internal quaternary alkylbenzene selectivity obtained using mordenite catalysts is expected in the absence of shape selectivity. It is found to be much lower than the internal quaternary alkylbenzene selectivity.

Claims (11)

a) a feed stream comprising a first acyclic C _8-28 paraffin at a first concentration comprising at least two or three primary carbon atoms and at least a second acyclic paraffin, at a temperature of from 20 to 250 ° C. and at atmospheric pressure to Passed through adsorption zones containing adsorbent phases containing silicalite under conditions of promoting adsorption at a pressure of 600 psi (g), C _5-8 cycloparaffins, C _5-8 normal paraffins, C _5-8 branched paraffins and these Contacting the adsorbent phase with a desorbent stream comprising a component selected from the group consisting of a combination of and recovering from the adsorption zone an adsorbent extract comprising a first acyclic paraffin at a second concentration higher than the first concentration. step; b) at least a portion of the adsorption extract is passed through a dehydrogenation zone and subjected to dehydrogenation conditions at a temperature of 400-900 ° C., a pressure of 0.15-147 psi (g) and a LHSV (liquid space velocity) of 0.1-100 hr ⁻¹ Operating a dehydrogenation zone at C, and then recovering from the dehydrogenation zone a dehydrogenated product stream comprising acyclic C _8-28 monoolefins comprising two or three primary carbon atoms; c) passing at least a portion of the feedstock comprising the phenyl compound and the dehydrogenated product stream comprising the acyclic monoolefin, respectively, into an alkylation zone and at a temperature of 80-225 ° C., 200-1000 psi (in the presence of an alkylation catalyst); operating an alkylation zone under a pressure of g) and an alkylation condition of an LHSV of 0.3-6 hr ⁻¹ to form a phenyl-alkane comprising molecules having one phenyl moiety and one C _8-28 aliphatic alkyl moiety The aliphatic alkyl moiety does not contain quaternary carbon atoms having 2 or 3 primary carbon atoms and not bonded by a carbon-carbon bond with a carbon atom of the phenyl moiety, and the alkylation step selects for 2-phenyl-alkanes. Is 40 to 100 and the selectivity to internal quaternary phenyl-alkanes is less than 10; And d) recovering the phenyl-alkanes from the alkylation zone Method for producing a phenyl-alkane comprising a. The method of claim 1 wherein the alkylation step is further characterized in that the selectivity for phenyl-alkanes having aliphatic alkyl moieties comprising quaternary carbon atoms not bonded by carbon atoms with carbon atoms of the phenyl moiety is less than 1. Way. The process according to claim 1 or 2, characterized in that 30-100 mole% of the feed stream consists of monomethyl paraffins. The swing bed system according to claim 1 or 2, comprising a simulated moving bed of adsorbent or a first adsorbent phase which is a non-zeolitic molecular sieve adsorbent and a second adsorbent phase which is a non-zeolitic molecular sieve adsorbent. swing bed system), wherein the feed stream passes over the first adsorbent and the desorbent stream passes over the second adsorbent. The process according to claim 1 or 2, characterized in that the concentration of normal paraffins in the adsorption extract stream is less than 75 mol%. 3. The method of claim 1, wherein 85 to 100 mole percent of the acyclic monoolefins in at least a portion of the dehydrogenated product stream comprise acyclic monoolefins having three primary carbon atoms. How to. 3. The method of claim 1, wherein the adsorption extract passing through the dehydrogenation zone comprises unbranched paraffins passing through the dehydrogenation zone. 4. The silicalite containing of claim 1 or 2 disposed in a continuous simulated mobile bed adsorptive separation zone comprising an adsorbent chamber comprising a plurality of compartmentalized adsorbent beds separated by stream transport points used in the process. Passing a feed stream containing the desired monomethyl paraffin and raffinate compound onto the first adsorbent; Draining the raffinate stream comprising the raffinate compound from the adsorbent chamber; Passing the desorbent stream over a second adsorbent comprising silicalite in the adsorbent chamber; Separating an extract stream comprising desorbent and desired monomethyl paraffin from the adsorbent chamber; Periodically elevating the transport points of the feed, desorbent, extract, and raffinate streams within the adsorbent chamber to simulate backflow movement of the adsorbent phase and feed stream; Recovering the dehydrogenated product stream comprising monomethyl monoolefin; Continuously producing phenyl-alkanes by alkylating benzene with monomethyl monoolefins in the alkylation zone to form phenyl-alkanes. The process of claim 1 or 2, wherein the alkylated product stream comprising phenyl-alkanes is withdrawn from the alkylation zone and at least a portion of the alkylated product stream is contacted with a sulfonating agent to sulfonate the phenyl-alkanes and Producing a sulfonated product stream comprising alkane sulfonic acid, wherein the sulfonating agent is selected from the group consisting of sulfuric acid, chlorosulfonic acid, fuming sulfuric acid and sulfur trioxide. delete delete

Images