Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D207/00—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom
  • C07D207/02—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom
  • C07D207/18—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having one double bond between ring members or between a ring member and a non-ring member
  • C07D207/22—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having one double bond between ring members or between a ring member and a non-ring member with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
  • C07D207/24—Oxygen or sulfur atoms
  • C07D207/26—2-Pyrrolidones
  • C07D207/263—2-Pyrrolidones with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to other ring carbon atoms
  • C07D207/267—2-Pyrrolidones with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to other ring carbon atoms with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to the ring nitrogen atom

Definitions

• ABSTRACT Process for the preparation of 1,3-bis(2-pyrrolidonyl) v butane comprising heating 1,3-bis(2- pyrro1idonyl)-l-butene to a temperature above the melting point thereof under hydrogen pressure in the presence of a hydrogenation catalyst for a sufficient period of time to substantially hydrogenate the 1,3- bis(2-pyrro1id0nyl)-1-butene and thereafter, recovering the hydrogenated product.
• This invention relates to processes for the hydrogenation of vinyl pyrrolidone dimer and to the use of the hydrogenated dimer as a selective solvent for recovery of aromatic hydrocarbons. More particularly, this invention relates to processes for the preparation of l,3-bis(2-pyrrolidonyl)butane by hydrogenation of 1,3- bis(2-pyrrolidonyl)-l-butene and to the use of the hydrogenated dimer as a selective solvent inseparating aromatic hydrocarbons from aromatic/non-aromatic hydrocarbon mixtures.
• l,3-bis(2-pyrrolidonyl)butane has heretofore been obtained by the hydrogenation of 1,3-bis(2- pyrrolidonyl)-l-butene (see, for example, J. W. Schunbach et al., Monatsh. 87, 580-592 (1956)).
• This prior procedure involved the hydrogenation of a dilute solution of 1,3-bis(2-pyrrolidonyl)-l-butene in acetic acid at a low temperature in the presence of a noble metal catalyst.
• the hydrogenated dimer has also been prepared by reduction of l,3-bis(2-pyrrolidonyl)-lbutene with lithium aluminum hydride.
• the hydrogenated dimer provides a highly selective solvent for the extraction of aromatic hydrocarbons from aromatic/non-aromatic mixtures.
• the hydrogenated vinyl pyrrolidone dimer has been found highly efficient in extracting aromatics such as benzene, toluene, xylene, ethyl benzene and the like from hydrocarbon mixtures such as reformed gasoline, hydrogenated pyrolysis gasoline, oil gasification and coke oven mixtures by a liquid/liquid extraction process with a high degree of selectivity.
• the present invention provides a process for the preparation of l,3-bis(2- pyrrolidonyl)butane comprising heating 1,3-bis(2- pyrrolidonyl)-l-butene to a temperature above the melting point thereof under hydrogen pressure in the presence of a hydrogenation catalyst for a sufficient period of time to'substantially hydrogenate the 1,3- bis(2-pyrrolidonyl)-l-butene and thereafter recovering the hydrogenated product.
• a method for separating aromatic hydrocarbons from mixtures of aromatic/non-aromatic hydrocarbons comprising contacting a mixture of aromatic/- non-aromatic hydrocarbons with l,3-bis( 2- pyrrolidonyl)butane to form an aromatic hydrocarbonrich extract phase and a raffinate phase, separating the aromatic hydrocarbon-rich extract phase from the mixture and recovering the aromatic hydrocarbon from said extract phase.
• the vinyl pyrrolidone dimer, l,3-bis(2-pyrrolidonyl)- l-butene, employed as the starting material in the present invention can be prepared by treating a small amount of N-vinyl pyrrolidone at room temperature with anhydrous hydrogen chloride gas.
• An improved process for preparing the vinyl pyrrolidone dimer in higher yields and purity as well as lighter color is described in applicants co-pending patent application U.S. Ser. No. 172,311, filed Aug. 16, 1971 entitled Process for the Dime-rization of Vinyl Pyrrolidone and assigned to the same assignee as herein.
• This improved process involves heating N-vinyl pyrrolidone at temperatures ranging from about 60 to about 150C. in the presence of a catalytic amount of an aqueous acid, maintaining the reaction temperature in said range throughout the course of the reaction and thereafter, recovering the vinyl pyrrolidone dimer.
• the vinyl pyrrolidone dimer can be hydrogenated in accordance with the present invention by being charged to a suitable hydrogenation reaction vessel such as an autoclave or rocker bomb after the reaction Vessel has been purged with an inert gas such as nitrogen.
• the catalyst is also charged to the reactor.
• the vinyl pyrrolidone dimer is then heated to a temperature sufficient to render the dimer in a molten condition. Generally, depending upon the purity of the dimer, it will melt at temperatures ranging from 60C. to about 78C. Since the reaction is conducted at temperatures which are high enough to melt the vinyl pyrrolidone dimer, there is no need in the present invention to employ a solvent.
• the vinyl pyrrolidone dimer melts at relatively low temperature, it is considered preferable to employ higher temperatures since higher reaction rates are thus obtained enabling the use of less active catalysts.
• the reaction is conducted at temperatures ranging from about 80C. to about C. although higher or lower temperatures can be employed if desired. At temperatures above about C., however, the vinyl pyrrolidone dimer will gradually decompose to yield undesirable by-products.
• any conventional hydrogenation catalyst can be employed.
• the hydrogenation catalysts employed in the present invention are well known in the art and are disclosed along with suitable methods for their preparation in numerous patents and other publications.
• Typical of the hydrogenation catalyst which can be employed in the present invention are nickel, platinum, rhodium, ruthenium, cobalt, copper-chromate, rhenium and the like, whether supported or unsupported.
• catalysts based on nickel are preferred for use in the present invention, since they are not only generally lower in cost, but also give a far lighter colored product as compared to most of the other catalysts which can be employed.
• Typical nickel catalysts which can be employed are, for example, skeletal (Raney) nickel, and nickel on various supports such as silica, alumina, kieselguhr and the like. These catalysts can also contain other metals as promotors, such as copper, manganese, zirconium and noble metals.
• the amount of catalyst employed can vary widely depending upon the activity of the catalyst and the nature of the reactor employed, for example, less than 1% by weight of the catalyst based on the weight of vinyl pyrrolidone dimer can be employed when a noble metal catalyst is used in a stirred reactor. Large amounts of catalyst are employed, for example, about percent by weight based on the weight of vinyl pyrrolidone dimer in fixed beds for use in a flow reactor. Thus, depending upon the activity of the catalyst and the type of reactor employed, the amount of catalyst can range from about 0.1 percent to about 10 percent by weight based on the weight of the vinyl pyrrolidone dimer.
• hydrogen can be charged to the reaction vessel at pressures generally ranging from about 100 to about 5,000 psig. depending upon the particular catalyst employed, for example, lower hydrogen pressures can be employed with noble metal catalysts whereas intermediate hydrogen pressures can be employed with active nickel catalysts and generally higher hydrogen pressures can be employed when using relatively inactive nickel or cobalt catalysts.
• the hydrogenation reaction of the present invention can either be conducted on a continuous or batch basis using stirred sump reactors, packed towers, autoclaves, rocker bombs and the like.
• the recovery of the hydrogenated vinyl pyrrolidone dimer is quite convenient since no solvent is employed in the process of the present invention.
• the unreacted hydrogen can be vented and recycled for subsequent use and the reaction mixture can be filtered to separate the reaction product from the catalyst.
• the hydrogenation reaction of the present invention gives an essentially quantitative conversion of vinyl pyrrolidone dimer to l,3-bis(2-pyrrolidonyl)butane. For example, a crude dimer of 85 percent purity gives a prodnet assaying about percent of the hydrogenated dimer.
• the hydrogenated vinyl pyrrolidone dimer obtained in accordance with the present invention is useful as an extremely high boiling and stable solvent of the aprotic hydrogen bonding type. Because of its high stability and low vapor pressure, it can be suitably employed as a solvent for gases such as carbon dioxide, sulfur dioxide and hydrogen sulfide. It can also be employed as a selective solvent for the extraction of hydrocarbons such as acetylenes, olefins and aromatics.
• the hydrogenated vinyl pyrrolidone dimer can also be employed as a coalescing agent for latex films, as a leveling and dye stripping agent for dyeing and as a solvent for a variety of chemicals and polymers.
• the hydrogenated vinyl pyrrolidone dimer can be used in a wide variety of applications, it has been found to be especially useful as a selective solvent for the extraction of aromatic hydrocarbons from mixtures of aromatic/non-aromatic hydrocarbons with a surprisingly high selectivity for said aromatic hydrocarbons.
• selectivity which in this instance, is the ratio of extracted aromatics to extracted non-aromatics
• selectivity is a critical performance factor which, in a continuous commercial process, is more important than the total extraction.
• the hydrocarbon mixture of aromatic hydrocarbons and nonaromatic hydrocarbons must be brought into good contact with the hydrogenated vinyl pyrrolidone dimer to permit mass transfer of the aromatic hydrocarbon into the hydrogenated vinyl pyrrolidone dimer stream and thereafter the dimer stream must be separated from the hydrocarbon mixture.
• a quantity of the feed liquid is admixed with a quantity of the hydrogenated vinyl pyrrolidone solvent in an agitated vessel, after which the layers are allowed to settle and separate into an extract phase and a raffinate phase. This gives about one theoretical contact, which is adequate in simple extractions. The operation can of course be repeated if more than one contact is required.
• Most commercial extraction equipment is continuous, with either successive stage contacts or differential contacts. Representative types are mixture-settlers, vertical towers of various kinds which operate by gravity flow, agitated tower extractors and centrifugal extractors.
• the mixer and settler can be the same unit.
• a tank containing a turbine or propeller agitator is most common.
• the agitator is shut off, the layers allowed to separate by gravity, and extract and raffinate drawn off to separate receivers through a bottom drain line.
• the mixing and settling times required for a given extraction can vary widely, for example, 5 minutes for mixing and 20 minutes for settling are typical, but both shorter and much longer times are common.
• the mixer and settler are generally separate pieces of equipment.
• the mixer can be a small agitator tank provided with inlets and a drawoff line and baffles to prevent short-circuiting; or maybe a centrifugal pump or other flow mixer.
• the settler is often a simple continuous decanter. With liquids which emulsify easily and which have nearly the same density, it may be necessary to pass the effluent from the mixer through a screen or pad of glass fiber to coalesce the droplets of the dispersed phase before gravity settling is feasible. lf, as is usual, several contact stages are required, a train of mixer-settlers can be operated with counter-current flow. The raffinate from each settler becomes the feed to the next mixer, where it meets intermediate extract or fresh solvent.
• the aromatic/non-aromatic hydrocarbon mixtures from which the aromatic hydrocarbons are extracted in accordance with the present invention are mixtures such as reformed gasoline, hydrogenated pyrolysis gasoline, oil gasification and coke oven products.
• Aromatics such as benzene, toluene, xylene, ethyl benzene and the like are contained in these mixtures together with aliphatic hydrocarbons both saturated and unsaturated such as n-butane, isobutane, n-hexane, butene-l, butene-2, amylenes and the like.
• the aromatic/non-aromatic hydrocarbons are brought into intimate contact with the hydrogenated vinyl pyrrolidone dimer, l,3-bis(2-pyrrolidonyl)butane in a mixingzone, preferably an intensive mixing zone wherein the two streams undergo high shear agitation. Intimate contact between the two streams is necessary in order to effect a high degree of mass transfer between the hydrocarbon stream and the hydrogenated vinyl pyrrolidone dimer.
• the period of intensive mixing will vary widely depending upon the nature of the hydrocarbon stream and the particular mixing equipment employed. Generally, sufficient mixing is permitted to ensure effective contact of the extraction solvent with the bulk of the hydrocarbon stream.
• the resulting mixture is allowed to settle into a two phase system comprising an aromatic-rich extract phase and a raffinate phase.
• the extract and raffinate phases are then separated by decantation or other conventional separation techniques for separating immiscible phases.
• the aromatic hydrocarbons are recovered from the extract phase generally by distillation and the extract solvent comprising primarily the hydrogenated vinyl pyrrolidone dimer can be recycled to the extraction process.
• Example 1 Into a one gallon stainless steel stirred hydrogenation autoclave was charged 2,000 gms. of vinyl pyrrolidone dimer (l,3-bis(2-pyrrolidonyI)-l-butene) which was analyzed by gas chromatography to be 93 percent pure and 40 gms. of 62.5 percent nickel-on-kieselguhr catalyst.
• Example 2 The catalyst recovered from Example 1 was charged to a one gallon stainless steel stirred hydrogenation autoclave together with a fresh 2,000 gms. aliquot of the vinyl pyrrolidone dimer. Hydrogenation was effected as described in Example 1 and required 9 hours for completion of hydrogen consumption. After a total of 13 hours at 120C. and 300 psig. hydrogen, the autoclave was cooled, vented, purged with nitrogen and discharged. The product obtained was identical to the product obtained in Example 1.
• Example 3 Into a one liter stainless steel rocker bomb was charged 666 gms. of vinyl pyrrolidone dimer (92 percent pure) and 6.7 gms. of 5 percent palladium-oncarbon catalyst. After purging with nitrogen and hydrogen, the bomb was heated to C. and rocked at 80C. and psig. of hydrogen. Absorption of hydrogen was complete after 4 hours. After a total of 8 hours, the bomb was cooled, vented, purged and discharged. The product was separated by filtration with a suction filter yielding a clear brown liquid which assayed as 92 percent hydrogenated vinyl pyrrolidone dimer.
• Example 4 Into a one liter stainless steel rocker bomb was charged 500 gms. of vinyl pyrrolidone dimer (83 percent pure) and 10.0 gms. of 65 percent cobalt-onkieselguhr catalyst. The hydrogenation required 16 hours for completion at 140C. and 2,000 psig. of hydrogen. After a total of 20 hours, the reactor was cooled, vented, purged and discharged. The product was separated by filtration with a suction funnel giving a'clear amber liquid assaying as 82 percent hydrogenated vinyl pyrrolidone dimer.
• Example 5 Into a one liter stainless steel rocker bomb was charged 500 gms. of vinyl pyrrolidone dimer (83' per cent pure) and 5.0 gms. of skeletal nickel catalyst. The hydrogenation reaction required two hours at C. and 300 psig. of hydrogen for completion. After filtration separate the catalyst, the recovered product assayed 80 percent hydrogenated vinyl pyrrolidone dimer.
• Example 6 Into a one liter stainless steel rocker bomb was charged 500 gms. of vinyl pyrrolidone dimer (99 percent pure) and 10.0 gms. of zirconium-promoted 53 percent nickel-on-kie selguhr catalyst. Hydrogenation was complete after two hours at C. and 300 psig. After filtration separate the catalyst, the product assayed 97 percent hydrogenation vinyl pyrrolidone dimer.
• Example 7 illustrates the use of the hydrogenated vinyl pyrrolidone dimer as a selective extraction solvent for aromatic hydrocarbons from a mixture of aromatic and non-aromatic hydrocarbons.
• Example 7 In this example, solutions were prepared of a mixture of heptane and toluene in a 50:50 weight ratio. These solutions were extracted with mixtures of the hydrogenated vinyl pyrrolidone dimer l,3-bis(2- pyrrolidonyl)butane, and varying amounts of water as shown in Table 1 below.
• Example 8 In this example, solutions were prepared of a mixture of heptane and toluene in a 50:50 weight ratio. These solutions were extracted with mixtures of the hydrogenated vinyl pyrrolidone dimer and varying amounts of water and compared with other known extraction solvents containing the same amount of water. Table 3 below summarizes the results obtained and illustrates a Although specific materials and conditions were set forth in the above exemplary processes in making and using the hydrogenated vinyl pyrrolidone dimer of the present invention, these are merely intended as illustrations of the present invention. Various other reaction conditions, aromatic/non-aromatic mixtures and extraction processes such as those listed above can be substituted in the examples with similar results.
• a process for the separation, with enhanced selectivity, of aromatic hydrocarbons from mixtures thereof with non-aromatic hydrocarbons consisting essentially of:

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• Chemical & Material Sciences (AREA)
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Citations (1)

• 1971
  • 1971-08-16 US US00172198A patent/US3772186A/en not_active Expired - Lifetime
• 1972
  • 1972-07-28 CA CA148,223A patent/CA987692A/en not_active Expired
  • 1972-08-02 GB GB3618072A patent/GB1395087A/en not_active Expired
  • 1972-08-14 DE DE2239920A patent/DE2239920A1/de active Pending
  • 1972-08-15 JP JP47081766A patent/JPS4829762A/ja active Pending
• 1978
  • 1978-03-22 JP JP3279678A patent/JPS53127421A/ja active Pending

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