Method for treating C five fraction and use of olefinic bond-containing compound
阅读说明：本技术 碳五馏分的处理方法及含烯键化合物的用途 (Method for treating C five fraction and use of olefinic bond-containing compound ) 是由 杨万泰 于 2020-04-29 设计创作，主要内容包括：本发明公开了一种碳五馏分的处理方法及含烯键化合物的用途。该方法包括：(1)将碳五馏分、含烯键化合物和溶剂在自由基引发剂的存在下进行聚合反应,得到含有固体反应产物的混合液；(2)(2)除去混合液中的固体反应产物,得上清液。本发明的方法能够提高碳五馏分中戊烷的含量。(The invention discloses a method for treating carbon five fraction and application of an olefinic bond-containing compound. The method comprises the following steps: (1) carrying out polymerization reaction on the carbon five fraction, the ethylenic bond-containing compound and a solvent in the presence of a free radical initiator to obtain a mixed solution containing a solid reaction product; (2) and (2) removing the solid reaction product in the mixed solution to obtain a supernatant. The method can improve the content of pentane in the carbon five fraction.)
1. A method for treating a carbon five fraction is characterized by comprising the following steps:
(1) carrying out polymerization reaction on the carbon five fraction, the ethylenic bond-containing compound and a solvent in the presence of a free radical initiator to obtain a mixed solution containing a solid reaction product; the ethylenic bond-containing compound is selected from maleic anhydride compounds shown in formula (I), maleimide compounds shown in formula (II) or itaconic anhydride compounds shown in formula (III):
in the formula (I), R1And R2Each independently selected from a hydrogen atom or an alkyl group of C1-C5;
in the formula (II), R3And R4Each independently selected from a hydrogen atom or a C1-C3 alkyl group; r5One selected from a hydrogen atom, a C1-C6 alkyl group, a C3-C6 cycloalkyl group, a C6-C20 aralkyl group, a C7-C20 alkaryl group, an aryl group substituted by a group containing a heteroatom selected from N, O or S, or an aralkyl group substituted by a group containing a heteroatom selected from N, O or S;
in the formula (III), R6、R7、R8Each independently selected from a hydrogen atom or an alkyl group of C1-C5;
(2) removing the solid reaction product in the mixed solution to obtain supernatant.
2. The process according to claim 1, wherein in the formula (I), R is1And R2Each independently selected from a hydrogen atom, a methyl group or an ethyl group; in the formula (II), R3And R4Each independently selected from a hydrogen atom or a methyl group; r5One selected from hydrogen atom, C1-C4 alkyl, cyclohexyl, phenyl or benzyl; in the formula (III), the compound represented by the formula (III),R6、R7、R8each independently selected from a hydrogen atom or an alkyl group having from C1 to C3.
3. The process of claim 1, wherein the initiator is selected from one or more of azobisisobutyronitrile, dibenzoyl peroxide, t-butyl hydroperoxide, dicumyl peroxide, lauroyl peroxide, dicetyl peroxydicarbonate, and cumyl peroxyneodecanoate.
4. The process of claim 1, wherein the solvent is selected from one or more of xylene, benzene, butyl acetate, acetone, ethylbenzene, cumene, and toluene.
5. The method according to claim 1, wherein the mass ratio of the pentad fraction to the ethylenic compound is 1:0.5 to 4, and the mass ratio of the radical initiator to the pentad fraction is 1:1.5 to 20.
6. The method according to claim 1, wherein the polymerization is carried out in an inert atmosphere at a temperature of 30 to 200 ℃ for 1 to 15 hours.
7. The treatment method according to claim 1, wherein in the step (2), the solid reaction product in the mixed solution is removed by centrifugation, the rotation speed of the centrifuge is 2000-6000 rpm, and the centrifugation time is 3-15 min.
8. The process of claim 1 wherein said carbon five fraction is derived from petroleum cracking.
9. The process according to any one of claims 1 to 8, further comprising a step of separating the supernatant by distillation.
10. Use of an ethylenic compound selected from the group consisting of maleic anhydrides of formula (I), maleimide compounds of formula (II) and itaconic anhydrides of formula (III) for treating a carbon five cut to increase the pentane content:
in the formula (I), R1And R2Each independently selected from a hydrogen atom or an alkyl group of C1-C5;
in the formula (II), R3And R4Each independently selected from a hydrogen atom or a C1-C3 alkyl group; r5One selected from a hydrogen atom, a C1-C6 alkyl group, a C3-C6 cycloalkyl group, a C6-C20 aralkyl group, a C7-C20 alkaryl group, an aryl group substituted by a group containing a heteroatom selected from N, O or S, or an aralkyl group substituted by a group containing a heteroatom selected from N, O or S;
in the formula (III), R6、R7、R8Each independently selected from a hydrogen atom or an alkyl group having from C1 to C5.
Technical Field
The invention relates to a method for processing a carbon five fraction and application of an olefinic bond-containing compound.
Background
The pentane product has wide application, can be used as a foaming agent of expandable polystyrene and a polyurethane foam system, is used in the fields of heat preservation of fluorine-free refrigerators, freezers, refrigeration houses, pipelines and the like, and can be used as a carrier solvent of a linear low-density polyethylene catalyst, an industrial solvent for deasphalting, an extractant for dewaxing a molecular sieve and the like.
Cracking petroleum to obtain low molecular weight olefins is currently an important process for the industrial production of ethylene. Petroleum, when cracked, produces a large amount of cracked fractions in addition to low molecular weight olefins. The carbon five fraction contains a large amount of pentane (n-pentane, i-pentane), which would result in a large economic benefit if it could be used for industrial production.
CN109305877A discloses a method for producing high olefin carbon five, n-pentane, isopentane and cyclopentane by using crude carbon five, which comprises feeding crude carbon five and an extraction solvent into an alkane separation tower; the top material of the alkane separation tower firstly enters into hydrogenation reaction to be completely changed into alkane; the material in the tower kettle enters an extraction solvent recovery tower, high olefin carbon five is obtained at the tower top, and the extraction solvent obtained at the tower kettle is recycled; then the mixture enters the top of a light component removal tower to separate carbon four light components; obtaining six components of n-pentane, isopentane, cyclopentane and carbon from the tower kettle; the tower bottom material enters the top of an isopentane separation tower to obtain isopentane, and the tower bottom obtains n-pentane, cyclopentane and six carbon components; the tower kettle enters an n-pentane separation tower, and n-pentane is obtained at the tower top; obtaining cyclopentane and carbon six-weight components at the tower bottom; the tower kettle enters a cyclopentane separation tower, cyclopentane is obtained at the tower top, and the carbon six components are obtained at the tower kettle. The method adopts an extractive distillation method to separate pentane from the C five fraction.
CN107739290A discloses a method for preparing a pentane foaming agent by cracking carbon five, which comprises the following steps: conveying the cracking carbon five raw materials through a pump, adding a desulfurizing agent, introducing into a buffer tank, and then introducing into a rectifying tower, wherein the material obtained at the top of the rectifying tower is a desulfurization product. Preheating the obtained desulfurization product by a preheater and introducing the preheated desulfurization product into a hydrogenation reactor; and sequentially connecting the obtained hydrogenation product by a light component removal tower, an isopentane separation tower, an n-pentane separation tower and a cyclopentane separation tower, and respectively obtaining isopentane from the top of the isopentane separation tower, n-pentane from the top of the n-pentane separation tower and cyclopentane from the top of the cyclopentane separation tower through continuous rectification. The method adopts a catalytic hydrogenation method to obtain pentane by taking a carbon five fraction as a raw material.
Disclosure of Invention
In view of the above, an object of the present invention is to provide a method for treating a carbon five fraction. The method adopts a free radical polymerization method to improve the content of pentane in the carbon five fraction.
Another object of the invention is to provide the use of an olefinic bond-containing compound in the treatment of a carbon five cut to increase the pentane content.
The technical scheme is adopted to achieve the purpose.
In one aspect, the present invention provides a method for treating a carbon five fraction, comprising the steps of:
(1) carrying out polymerization reaction on the carbon five fraction, the ethylenic bond-containing compound and a solvent in the presence of a free radical initiator to obtain a mixed solution containing a solid reaction product; the ethylenic bond-containing compound is selected from maleic anhydride compounds shown in formula (I), maleimide compounds shown in formula (II) or itaconic anhydride compounds shown in formula (III):
in the formula (I), R1And R2Each independently selected from a hydrogen atom or an alkyl group of C1-C5;
in the formula (II), R3And R4Each independently selected from a hydrogen atom or a C1-C3 alkyl group; r5One selected from a hydrogen atom, a C1-C6 alkyl group, a C3-C6 cycloalkyl group, a C6-C20 aralkyl group, a C7-C20 alkaryl group, an aryl group substituted by a group containing a heteroatom selected from N, O or S, or an aralkyl group substituted by a group containing a heteroatom selected from N, O or S;
in the formula (III), R6、R7、R8Each independently selected from a hydrogen atom or an alkyl group of C1-C5;
(2) removing the solid reaction product in the mixed solution to obtain supernatant.
According to the treatment process of the present invention, preferably, in the formula (I), R1And R2Each independently selected from a hydrogen atom, a methyl group or an ethyl group; in the formula (II), R3And R4Each independently selected from a hydrogen atom or a methyl group; r5One selected from hydrogen atom, C1-C4 alkyl, cyclohexyl, phenyl or benzyl; in the formula (III), R6、R7、R8Each independently selected from a hydrogen atom or an alkyl group having from C1 to C3.
According to the treatment method of the present invention, preferably, the initiator is selected from one or more of azobisisobutyronitrile, dibenzoyl peroxide, tert-butyl hydroperoxide, dicumyl peroxide, lauroyl peroxide, dicetyl peroxydicarbonate, and cumyl peroxyneodecanoate.
According to the treatment method of the present invention, preferably, the solvent is selected from one or more of xylene, benzene, butyl acetate, acetone, ethylbenzene, cumene and toluene.
According to the treatment method, the mass ratio of the carbon five fraction to the ethylenic compound is preferably 1: 0.5-4, and the mass ratio of the radical initiator to the carbon five fraction is preferably 1: 1.5-20.
According to the treatment method of the present invention, preferably, the polymerization reaction is performed in an inert atmosphere, the temperature of the polymerization reaction is 30 to 200 ℃, and the reaction time is 1 to 15 hours.
According to the treatment method provided by the invention, preferably, in the step (2), the solid reaction product in the mixed solution is removed by adopting a centrifugal mode, the rotating speed of a centrifugal machine is 2000-6000 rpm, and the centrifugal time is 3-15 min.
According to the treatment method of the invention, preferably, the carbon five fraction is derived from petroleum cracking.
According to the treatment method of the present invention, preferably, the method further comprises a step of separating the supernatant by distillation.
In another aspect, the present invention also provides the use of an ethylenic compound selected from the group consisting of maleic anhydride-based compounds represented by formula (I), maleimide-based compounds represented by formula (II) and itaconic anhydride-based compounds represented by formula (III) for treating a carbon five cut fraction to increase the content of pentane:
in the formula (I), R1And R2Each independently selected from a hydrogen atom or an alkyl group of C1-C5;
in the formula (II), R3And R4Each independently selected from a hydrogen atom or a C1-C3 alkyl group; r5One selected from a hydrogen atom, a C1-C6 alkyl group, a C3-C6 cycloalkyl group, a C6-C20 aralkyl group, a C7-C20 alkaryl group, an aryl group substituted by a group containing a heteroatom selected from N, O or S, or an aralkyl group substituted by a group containing a heteroatom selected from N, O or S;
in the formula (III), R6、R7、R8Each independently selected from a hydrogen atom or an alkyl group having from C1 to C5.
The method adopts a free radical polymerization method to improve the content of pentane in the carbon five fraction for the first time. The invention also provides the use of an ethylenic compound for treating a carbon five cut to increase the pentane content.
Detailed Description
The present invention will be further described with reference to the following specific examples, but the scope of the present invention is not limited thereto.
The carbon five fraction of the present invention may be derived from petroleum cracking or coal chemical industries. The C five fraction contains a large amount of components such as isopentane, n-pentane, isoprene, cyclopentadiene, 1, 3-pentadiene, piperylene, dicyclopentadiene and the like.
The pentane of the present invention includes isopentane and n-pentane.
< treatment method >
The method for treating the carbon five fraction comprises the following steps: (1) a step of polymerization; (2) solid-liquid separation; and optionally, a step of distillative separation. As described in detail below.
Step of polymerization
And carrying out polymerization reaction on the carbon five fraction, the ethylenic bond-containing compound and the solvent in the presence of a free radical initiator to obtain a mixed solution containing a solid reaction product.
The ethylenic bond-containing compound in the invention is selected from maleic anhydride compounds shown in formula (I), maleimide compounds shown in formula (II) or itaconic anhydride compounds shown in formula (III). The specific structure is as follows.
The maleic anhydride compound of the invention has a structure shown in formula (I):
in the formula (I), R1And R2Each independently selected from a hydrogen atom or an alkyl group having from C1 to C5. Examples of C1 to C5 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl and the like. Preferably, R1And R2Each independently selected from a hydrogen atom, a methyl group or an ethyl group. The substituent groups have proper volume and small steric hindrance, and can ensure the smooth proceeding of free radical polymerization reaction.
Examples of the maleic anhydride-based compound of the present invention include, but are not limited to, maleic anhydride, methyl maleic anhydride, ethyl maleic anhydride, dimethyl maleic anhydride, diethyl maleic anhydride, di-n-propyl maleic anhydride, diisopropyl maleic anhydride, 1-methyl-2-ethyl maleic anhydride, 1-methyl-2-n-propyl maleic anhydride, 1-methyl-2-isopropyl maleic anhydride, 1-methyl-2-n-butyl maleic anhydride, 1-methyl-2-isobutyl maleic anhydride, 1-methyl-2-tert-butyl maleic anhydride, 1-methyl-2-n-pentyl maleic anhydride, 1-methyl-2-isopentyl maleic anhydride, 1-methyl-2-neopentyl maleic anhydride, 1-ethyl-2-n-propyl maleic anhydride, 1-ethyl-2-isopropyl maleic anhydride, and the like. Preferably, the maleic anhydride compound of the present invention is selected from one or more of maleic anhydride, methyl maleic anhydride, ethyl maleic anhydride, dimethyl maleic anhydride and diethyl maleic anhydride. This facilitates the polymerization reaction.
The maleimide compound of the present invention has a structure represented by the formula (II):
in the formula (II), R3And R4Each independently selected from a hydrogen atom or a C1-C3 alkyl group; r5One selected from a hydrogen atom, a C1-C6 alkyl group, a C3-C6 cycloalkyl group, a C6-C20 aralkyl group, a C7-C20 alkaryl group, an aryl group substituted with a group containing a heteroatom selected from N, O or S, or an aralkyl group substituted with a group containing a heteroatom selected from N, O or S.
In the formula (II), R3And R4Each independently selected from a hydrogen atom or a C1 to C3 alkyl group. Examples of C1 to C3 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl. According to one embodiment of the invention, R3And R4Each independently selected from a hydrogen atom and a methyl group.
In the formula (II), R5One selected from a hydrogen atom, a C1-C6 alkyl group, a C3-C6 cycloalkyl group, a C6-C20 aralkyl group, a C7-C20 alkaryl group, an aryl group substituted with a group containing a heteroatom selected from N, O or S, or an aralkyl group substituted with a group containing a heteroatom selected from N, O or S. Preferably, R5One selected from hydrogen atom, C1-C4 alkyl, C5-C6 cycloalkyl, C7-C15 aralkyl or C7-C15 alkaryl. More preferably, R5One selected from hydrogen atom, C1-C4 alkyl, cyclohexyl, phenyl and benzyl.
Examples of C1 to C6 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl and the like. Examples of C3-C6 cycloalkyl include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. Examples of C6 to C20 aralkyl groups include, but are not limited to, phenyl, o-methylphenyl, m-methylphenyl, p-methylphenyl, 2, 3-dimethylphenyl, 2, 4-dimethylphenyl, o-ethylphenyl, m-ethylphenyl, p-ethylphenyl, and the like. Examples of C7-C20 alkaryl include, but are not limited to, benzyl, 2-methylbenzyl, 3-methylbenzyl, 4-methylbenzyl, 2, 3-dimethylbenzyl, 2, 4-dimethylbenzyl, and the like. Examples of aryl substituted with a group containing a heteroatom selected from N, O or S include, but are not limited to, o-methoxyphenyl, m-methoxyphenyl, p-methoxyphenyl, o-nitrophenyl, m-nitrophenyl, p-nitrophenyl, and the like, o-cyanophenyl, m-cyanophenyl, p-cyanophenyl, and the like. Examples of substituted aralkyl groups containing a heteroatom selected from N, O or S include, but are not limited to, 2-methylbenzyl, 3-methylbenzyl, 4-methylbenzyl, 2, 3-dimethylbenzyl, 2, 4-dimethylbenzyl, 2-methoxybenzyl, 3-methoxybenzyl, 4-methoxybenzyl, 2, 3-dimethoxybenzyl, 2, 4-dimethoxybenzyl, 2-nitrobenzyl, 3-nitrobenzyl, 4-nitrobenzyl, 2-cyanobenzyl, 3-cyanobenzyl, and 4-cyanobenzyl, and the like. The substituent groups have proper volume and small steric hindrance, and are favorable for the polymerization reaction. In addition, the maleimide compounds of these substituents can be directly dissolved in the cleavage fraction without adding an additional solvent.
Examples of the maleimide-based compound of the present invention include, but are not limited to, maleimide, N-methylmaleimide, N-ethylmaleimide, N-N-propylmaleimide, N-isopropylmaleimide, N-N-butylmaleimide, N-isobutylmaleimide, N-t-butylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-o-methylphenylmaleimide, N-m-methylphenylmaleimide, N-p-methylphenylmaleimide, N-o-methoxyphenylmaleimide, N-m-methoxyphenylmaleimide, N-p-methoxyphenylmaleimide, N-o-nitrophenylmaleimide, N-m-nitrophenylmaleimide, N-t-ethylmaleimide, N-t-butylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-o-methylphenylmaleimide, N-m-methoxyphenylmaleimide, N-p-methoxyphenylmaleimide, N-o-nitrophenylmaleimide, N-m-maleimide, N-p-isopropylmaleimide, N-p-butylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-p-butylmaleimide, N-p-isopropylmaleimide, N-p-isopropylmaleimide, N-p-tolylmaleimide, N-p-tolylmaleimide, p-tolylmaleimide, p-tolylmaleimide, N-p-tolylmaleimide, p-, N-p-nitrophenylmaleimide, N-o-cyanophenylmaleimide, N-m-cyanophenylmaleimide, N-p-cyanophenylmaleimide, N-benzylmaleimide, N- (2-methylbenzyl) maleimide, N- (3-methylbenzyl) maleimide, N- (4-methylbenzyl) maleimide, N- (2-methoxybenzyl) maleimide, N- (3-methoxybenzyl) maleimide, N- (4-methoxybenzyl) maleimide, N- (2-nitrobenzyl) maleimide, N- (3-nitrobenzyl) maleimide, N- (4-nitrobenzyl) maleimide, N- (3-cyanobenzyl) maleimide and N- (4-cyanobenzyl) Maleimide, and the like. Preferably, the maleimide-based compound of the present invention is selected from one or more of maleimide, N-methylmaleimide, N-ethylmaleimide, N-N-propylmaleimide, N-isopropylmaleimide, N-N-butylmaleimide, N-isobutylmaleimide, N-t-butylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide and N-benzylmaleimide.
According to a further preferred embodiment of the invention, R3And R4Are each a hydrogen atom; r5One selected from a hydrogen atom, a methyl group, an ethyl group, an n-propyl group and an isopropyl group.
According to a further preferred embodiment of the present invention, the maleimide-based compound of the present invention is selected from one or more of maleimide, N-methylmaleimide, N-ethylmaleimide, N-N-propylmaleimide or N-isopropylmaleimide.
The itaconic anhydride compound has a structure shown in a formula (III):
wherein R is6、R7And R8Each independently selected from a hydrogen atom or an alkyl group having from C1 to C5. The alkyl group of C1-C5 may be selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl. According to a particular embodiment of the invention, R6、R7And R8Each independently selected from a hydrogen atom or an alkyl group having from C1 to C3. The alkyl of C1-C3 may be selected from methyl, ethyl, n-propyl, isopropyl. According to another particular embodiment of the invention, formula (III) is itaconic anhydride. Thus, the polymerization reaction can be smoothly carried out; the reaction raw material can be directly dissolved in the fraction to be separated without adding extra solvent. The invention is not limited to the addition of other solvents to the polymerization reaction in order to allow the reaction to proceed better. Examples of other solvents include, but are not limited to, xylene.
Examples of the itaconic anhydride-based compound of the present invention include, but are not limited to, itaconic anhydride, 2-ethylene-succinic anhydride, 2-propylene-succinic anhydride, 3- (propyl-2-alkylene) oxolane-2, 5-dione, 3- (butyl-2-alkylene) oxolane-2, 5-dione, 3- (pentyl-3-alkylene) oxolane-2, 5-dione, 2-methylene-3-methyl-succinic anhydride, 2-methylene-3-ethyl-succinic anhydride, 2-methylene-3-propyl-succinic anhydride, 2-methylene-3-isopropyl-succinic anhydride, 2-methylene-3-butyl-succinic anhydride, 2-propylene-butylene-2-oxide, 2-propylene-2-oxide, 2-butylene-2-propylene-succinic anhydride, 2-butylene-2-butylene-succinic anhydride, 2-butylene-2-oxide, and 2-butylene-2-butylene-2-butylene-2-oxide, 2-methylene-3-isobutyl-succinic anhydride, 2-methylene-3-tert-butyl-succinic anhydride, 2-ethylene-3-methyl-succinic anhydride, 2-ethylene-3-ethyl-succinic anhydride, 2-ethylene-3-propyl-succinic anhydride, 2-ethylene-3-isopropyl-succinic anhydride, 2-ethylene-3-butyl-succinic anhydride, 2-ethylene-3-isobutyl-succinic anhydride, 2-ethylene-3-tert-butyl-succinic anhydride, 2-propylene-3-methyl-succinic anhydride, 2-propylene-3-ethyl-succinic anhydride, 2-propylene-3-propyl-succinic anhydride, 2-propylene-3-isopropyl-succinic anhydride, 2-propylene-3-butyl-succinic anhydride, 2-propylene-3-isobutyl-succinic anhydride, 2-propylene-3-tert-butyl-succinic anhydride, 3-methyl-4- (propyl-2-alkylene) oxolane-2, 5-dione, 3-ethyl-4- (propyl-2-alkylene) oxolane-2, 5-dione, 3-propyl-4- (propyl-2-alkylene) oxolane-2, 5-dione, 3-isopropyl-4- (propyl-2-alkylene) oxolane-2, 5-dione, 3-methyl-4- (butyl-2-alkylene) oxolane-2, 5-dione, 3-ethyl-4- (butyl-2-alkylene) oxolane-2, 5-dione, 3-propyl-4- (butyl-2-alkylene) oxolane-2, 5-dione, 3-isopropyl-4- (butyl-2-alkylene) oxolane-2, 5-dione, 3-methyl-4- (pentyl-3-alkylene) oxolane-2, 5-dione, 3-ethyl-4- (pentyl-3-alkylene) oxolane-2, 5-dione, 3-isopropyl-4- (pentyl-2-alkylene) oxolane, and combinations thereof, 3-propyl-4- (pentyl-3-alkylene) oxolane-2, 5-dione, 3-isopropyl-4- (pentyl-3-alkylene) oxolane-2, 5-dione.
The initiator of the present invention is a free radical initiator. Preferably, the radical initiator is an azo-type initiator or a peroxy-type initiator. Examples of azo-type initiators and peroxy-type initiators include, but are not limited to, azobisisobutyronitrile, dibenzoyl peroxide, t-butyl hydroperoxide, dicumyl peroxide, lauroyl peroxide, dicetyl peroxydicarbonate, cumyl peroxyneodecanoate. More preferably, the free radical initiator is selected from one or more of azobisisobutyronitrile, dibenzoyl peroxide or tert-butyl hydroperoxide. These radicals facilitate the polymerization.
In the present invention, the solvent may be selected from one or more of xylene, benzene, butyl acetate, acetone, ethylbenzene, cumene, and toluene. Preferably, the solvent is selected from one or more of xylene, benzene, butyl acetate, acetone. More preferably, the solvent is selected from one or more of xylene and benzene. This facilitates the polymerization reaction.
In the invention, the mass ratio of the carbon five fraction to the ethylenic compound can be 1: 0.5-4; preferably 1: 1.4-2.5; more preferably 1: 1.6-2. The mass ratio of the free radical initiator to the carbon five fraction is 1: 1.5-20; preferably 1: 3-15; more preferably 1:4 to 7. This facilitates the polymerization reaction to proceed sufficiently and can save the amount of the radical initiator and the ethylenic bond-containing compound.
The polymerization reaction of the present invention can be carried out under the protection of an inert gas. The inert gas may be nitrogen or argon. The temperature of the polymerization reaction can be 30-200 ℃; preferably 40-150 ℃; more preferably 40 to 90 ℃. The time of the polymerization reaction can be 1-15 hours; preferably 3-10 hours; more preferably 6 to 8 hours. This is advantageous in that the polymerization reaction can be sufficiently carried out and time can be saved.
Step of solid-liquid separation
The solid reaction product in the mixture was removed to obtain a supernatant. The solid reaction product is mainly the product of the polymerization reaction. The mixed solution also contains a large amount of unreacted substances in the form of liquid, and these substances are mainly pentane (n-pentane, isopentane) and the like. The solid reaction product in the mixed solution may be removed by a method conventional in the art, and is not particularly limited. Preferably, the solid reaction product is separated by centrifugation.
According to one embodiment of the present invention, the solid reaction product is separated from the mixed solution by centrifugation. The rotating speed of the centrifugal machine is 2000-6000 rpm; preferably 3000-6000 rpm; more preferably 3000 to 5000 rpm. Centrifuging for 3-15 min; preferably 3-10 min; more preferably 5 to 8 min. This allows a better separation of the solid reaction product and a higher pentane content in the supernatant.
Step of distillation separation
The obtained supernatant is distilled and separated to obtain pentane. The pentane contains isopentane and n-pentane. In certain embodiments, the pentane is a mixture of isopentane and n-pentane.
According to a specific embodiment of the present invention, 5 parts by weight of maleic anhydride, 0.6 part by weight of azobisisobutyronitrile and 10 parts by weight of xylene are added to 3 parts by weight of the carbon five fraction and reacted at 60 ℃ for 6 hours under the protection of an inert gas to obtain a mixed solution containing solids; the mixture was centrifuged at 4000rpm for 6min to remove the solid reaction product and obtain a supernatant containing pentane.
According to another embodiment of the present invention, 5.5 parts by weight of maleic anhydride, 0.65 parts by weight of dibenzoyl peroxide and 8 parts by weight of benzene are added to 3.5 parts by weight of the carbon five fraction and reacted at 70 ℃ for 4 hours under the protection of inert gas to obtain a mixture containing solids; the mixture was centrifuged at 4000rpm for 5min to remove the solid reaction product and obtain a supernatant containing pentane.
According to another embodiment of the present invention, 6 parts by weight of maleic anhydride, 0.35 part by weight of t-butyl hydroperoxide and 7 parts by weight of butyl acetate are added to 4 parts by weight of the carbon five fraction and reacted at 90 ℃ for 3 hours under the protection of inert gas to obtain a mixed solution containing solids; the mixture was centrifuged at 4000rpm for 4min to remove the solid reaction product and obtain a supernatant containing pentane.
According to another embodiment of the present invention, 7.4 parts by weight of maleic anhydride, 0.75 parts by weight of dicumyl peroxide and 5 parts by weight of acetone are added to 3.5 parts by weight of the carbon five fraction and reacted at 110 ℃ for 2.5 hours under the protection of inert gas to obtain a mixed solution containing solids; the mixture was centrifuged at 4000rpm for 3.5min to remove the solid reaction product and obtain a supernatant containing pentane.
According to a further embodiment of the present invention, 9 parts by weight of maleic anhydride, 1.3 parts by weight of lauroyl peroxide and 7 parts by weight of ethylbenzene are added to 5 parts by weight of the carbon five cut fraction and reacted at 130 ℃ for 3 hours under the protection of an inert gas to obtain a mixed solution containing solids; the mixture was centrifuged at 4000rpm for 3min to remove the solid reaction product and obtain a supernatant containing pentane.
According to still another embodiment of the present invention, 6 parts by weight of maleic anhydride, 1.5 parts by weight of dicetyl peroxydicarbonate and 8 parts by weight of cumene were added to 3.6 parts by weight of the C five fraction, and reacted at 140 ℃ for 2 hours under protection of an inert gas to obtain a mixed solution containing solids; the mixture was centrifuged at 4000rpm for 4min to remove the solid reaction product and obtain a supernatant containing pentane.
According to still another embodiment of the present invention, 8.5 parts by weight of maleic anhydride, 1.5 parts by weight of cumyl peroxyneodecanoate and 10 parts by weight of toluene are added to 5 parts by weight of the carbon five fraction and reacted at 150 ℃ for 1.5 hours under the protection of an inert gas to obtain a mixed solution containing solids; the mixture was centrifuged at 4000rpm for 5min to remove the solid reaction product and obtain a supernatant containing pentane.
< use >
The invention provides the use of an olefinic bond-containing compound in the treatment of a C five cut to increase the pentane content. The pentane content may be referred to as pentane concentration. The pentane comprises isopentane and n-pentane. In certain embodiments, the pentane is a mixture of isopentane and n-pentane. In the present invention, the ethylenic compound is selected from the maleic anhydride-based compound represented by formula (I), the maleimide-based compound represented by formula (II), or the itaconic anhydride-based compound represented by formula (III), and the specific structure is as follows.
The maleic anhydride compound of the invention has a structure shown in formula (I):
in the formula (I), R1And R2Are independently selected respectivelyFrom a hydrogen atom or an alkyl group having from C1 to C5. Examples of C1 to C5 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl and the like. Preferably, R1And R2Each independently selected from a hydrogen atom, a methyl group or an ethyl group. The substituent groups have proper volume and small steric hindrance, and can ensure the smooth proceeding of free radical polymerization reaction.
Examples of the maleic anhydride-based compound of the present invention include, but are not limited to, maleic anhydride, methyl maleic anhydride, ethyl maleic anhydride, dimethyl maleic anhydride, diethyl maleic anhydride, di-n-propyl maleic anhydride, diisopropyl maleic anhydride, 1-methyl-2-ethyl maleic anhydride, 1-methyl-2-n-propyl maleic anhydride, 1-methyl-2-isopropyl maleic anhydride, 1-methyl-2-n-butyl maleic anhydride, 1-methyl-2-isobutyl maleic anhydride, 1-methyl-2-tert-butyl maleic anhydride, 1-methyl-2-n-pentyl maleic anhydride, 1-methyl-2-isopentyl maleic anhydride, 1-methyl-2-neopentyl maleic anhydride, 1-ethyl-2-n-propyl maleic anhydride, 1-ethyl-2-isopropyl maleic anhydride, and the like. Preferably, the maleic anhydride compound of the present invention is selected from one or more of maleic anhydride, methyl maleic anhydride, ethyl maleic anhydride, dimethyl maleic anhydride and diethyl maleic anhydride. This facilitates the polymerization reaction.
The maleimide compound of the present invention has a structure represented by the formula (II):
in the formula (II), R3And R4Each independently selected from a hydrogen atom or a C1-C3 alkyl group; r5One selected from a hydrogen atom, a C1-C6 alkyl group, a C3-C6 cycloalkyl group, a C6-C20 aralkyl group, a C7-C20 alkaryl group, an aryl group substituted with a group containing a heteroatom selected from N, O or S, or an aralkyl group substituted with a group containing a heteroatom selected from N, O or S.
In the formula (II), R3And R4Each independently selected from a hydrogen atom or a C1 to C3 alkyl group. C1-C3 alkylExamples of (b) include, but are not limited to, methyl, ethyl, n-propyl, isopropyl. According to one embodiment of the invention, R3And R4Each independently selected from a hydrogen atom and a methyl group.
In the formula (II), R5One selected from a hydrogen atom, a C1-C6 alkyl group, a C3-C6 cycloalkyl group, a C6-C20 aralkyl group, a C7-C20 alkaryl group, an aryl group substituted with a group containing a heteroatom selected from N, O or S, or an aralkyl group substituted with a group containing a heteroatom selected from N, O or S. Preferably, R5One selected from hydrogen atom, C1-C4 alkyl, C5-C6 cycloalkyl, C7-C15 aralkyl or C7-C15 alkaryl. More preferably, R5One selected from hydrogen atom, C1-C4 alkyl, cyclohexyl, phenyl and benzyl.
Examples of C1 to C6 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl and the like. Examples of C3-C6 cycloalkyl include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. Examples of C6 to C20 aralkyl groups include, but are not limited to, phenyl, o-methylphenyl, m-methylphenyl, p-methylphenyl, 2, 3-dimethylphenyl, 2, 4-dimethylphenyl, o-ethylphenyl, m-ethylphenyl, p-ethylphenyl, and the like. Examples of C7-C20 alkaryl include, but are not limited to, benzyl, 2-methylbenzyl, 3-methylbenzyl, 4-methylbenzyl, 2, 3-dimethylbenzyl, 2, 4-dimethylbenzyl, and the like. Examples of aryl substituted with a group containing a heteroatom selected from N, O or S include, but are not limited to, o-methoxyphenyl, m-methoxyphenyl, p-methoxyphenyl, o-nitrophenyl, m-nitrophenyl, p-nitrophenyl, and the like, o-cyanophenyl, m-cyanophenyl, p-cyanophenyl, and the like. Examples of substituted aralkyl groups containing a heteroatom selected from N, O or S include, but are not limited to, 2-methylbenzyl, 3-methylbenzyl, 4-methylbenzyl, 2, 3-dimethylbenzyl, 2, 4-dimethylbenzyl, 2-methoxybenzyl, 3-methoxybenzyl, 4-methoxybenzyl, 2, 3-dimethoxybenzyl, 2, 4-dimethoxybenzyl, 2-nitrobenzyl, 3-nitrobenzyl, 4-nitrobenzyl, 2-cyanobenzyl, 3-cyanobenzyl, and 4-cyanobenzyl, and the like. The substituent groups have proper volume and small steric hindrance, and are favorable for the polymerization reaction. In addition, the maleimide compounds of these substituents can be directly dissolved in the cleavage fraction without adding an additional solvent.
Examples of the maleimide-based compound of the present invention include, but are not limited to, maleimide, N-methylmaleimide, N-ethylmaleimide, N-N-propylmaleimide, N-isopropylmaleimide, N-N-butylmaleimide, N-isobutylmaleimide, N-t-butylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-o-methylphenylmaleimide, N-m-methylphenylmaleimide, N-p-methylphenylmaleimide, N-o-methoxyphenylmaleimide, N-m-methoxyphenylmaleimide, N-p-methoxyphenylmaleimide, N-o-nitrophenylmaleimide, N-m-nitrophenylmaleimide, N-t-ethylmaleimide, N-t-butylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-o-methylphenylmaleimide, N-m-methoxyphenylmaleimide, N-p-methoxyphenylmaleimide, N-o-nitrophenylmaleimide, N-m-maleimide, N-p-isopropylmaleimide, N-p-butylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-p-butylmaleimide, N-p-isopropylmaleimide, N-p-isopropylmaleimide, N-p-tolylmaleimide, N-p-tolylmaleimide, p-tolylmaleimide, p-tolylmaleimide, N-p-tolylmaleimide, p-, N-p-nitrophenylmaleimide, N-o-cyanophenylmaleimide, N-m-cyanophenylmaleimide, N-p-cyanophenylmaleimide, N-benzylmaleimide, N- (2-methylbenzyl) maleimide, N- (3-methylbenzyl) maleimide, N- (4-methylbenzyl) maleimide, N- (2-methoxybenzyl) maleimide, N- (3-methoxybenzyl) maleimide, N- (4-methoxybenzyl) maleimide, N- (2-nitrobenzyl) maleimide, N- (3-nitrobenzyl) maleimide, N- (4-nitrobenzyl) maleimide, N- (3-cyanobenzyl) maleimide and N- (4-cyanobenzyl) Maleimide, and the like. Preferably, the maleimide-based compound of the present invention is selected from one or more of maleimide, N-methylmaleimide, N-ethylmaleimide, N-N-propylmaleimide, N-isopropylmaleimide, N-N-butylmaleimide, N-isobutylmaleimide, N-t-butylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide and N-benzylmaleimide.
According to a further preferred embodiment of the invention, R3And R4Are each a hydrogen atom; r5One selected from a hydrogen atom, a methyl group, an ethyl group, an n-propyl group and an isopropyl group.
According to a further preferred embodiment of the present invention, the maleimide-based compound of the present invention is selected from one or more of maleimide, N-methylmaleimide, N-ethylmaleimide, N-N-propylmaleimide or N-isopropylmaleimide.
The itaconic anhydride compound has a structure shown in a formula (III):
wherein R is6、R7And R8Each independently selected from a hydrogen atom or an alkyl group having from C1 to C5. The alkyl group of C1-C5 may be selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl. According to a particular embodiment of the invention, R6、R7And R8Each independently selected from a hydrogen atom or an alkyl group having from C1 to C3. The alkyl of C1-C3 may be selected from methyl, ethyl, n-propyl, isopropyl. According to another particular embodiment of the invention, formula (III) is itaconic anhydride. Thus, the polymerization reaction can be smoothly carried out; the reaction raw material can be directly dissolved in the fraction to be separated without adding extra solvent. The invention is not limited to the addition of other solvents to the polymerization reaction in order to allow the reaction to proceed better. Examples of other solvents include, but are not limited to, xylene.
Examples of the itaconic anhydride-based compound of the present invention include, but are not limited to, itaconic anhydride, 2-ethylene-succinic anhydride, 2-propylene-succinic anhydride, 3- (propyl-2-alkylene) oxolane-2, 5-dione, 3- (butyl-2-alkylene) oxolane-2, 5-dione, 3- (pentyl-3-alkylene) oxolane-2, 5-dione, 2-methylene-3-methyl-succinic anhydride, 2-methylene-3-ethyl-succinic anhydride, 2-methylene-3-propyl-succinic anhydride, 2-methylene-3-isopropyl-succinic anhydride, 2-methylene-3-butyl-succinic anhydride, 2-propylene-butylene-2-oxide, 2-propylene-2-oxide, 2-butylene-2-propylene-succinic anhydride, 2-butylene-2-butylene-succinic anhydride, 2-butylene-2-oxide, and 2-butylene-2-butylene-2-butylene-2-oxide, 2-methylene-3-isobutyl-succinic anhydride, 2-methylene-3-tert-butyl-succinic anhydride, 2-ethylene-3-methyl-succinic anhydride, 2-ethylene-3-ethyl-succinic anhydride, 2-ethylene-3-propyl-succinic anhydride, 2-ethylene-3-isopropyl-succinic anhydride, 2-ethylene-3-butyl-succinic anhydride, 2-ethylene-3-isobutyl-succinic anhydride, 2-ethylene-3-tert-butyl-succinic anhydride, 2-propylene-3-methyl-succinic anhydride, 2-propylene-3-ethyl-succinic anhydride, 2-propylene-3-propyl-succinic anhydride, 2-propylene-3-isopropyl-succinic anhydride, 2-propylene-3-butyl-succinic anhydride, 2-propylene-3-isobutyl-succinic anhydride, 2-propylene-3-tert-butyl-succinic anhydride, 3-methyl-4- (propyl-2-alkylene) oxolane-2, 5-dione, 3-ethyl-4- (propyl-2-alkylene) oxolane-2, 5-dione, 3-propyl-4- (propyl-2-alkylene) oxolane-2, 5-dione, 3-isopropyl-4- (propyl-2-alkylene) oxolane-2, 5-dione, 3-methyl-4- (butyl-2-alkylene) oxolane-2, 5-dione, 3-ethyl-4- (butyl-2-alkylene) oxolane-2, 5-dione, 3-propyl-4- (butyl-2-alkylene) oxolane-2, 5-dione, 3-isopropyl-4- (butyl-2-alkylene) oxolane-2, 5-dione, 3-methyl-4- (pentyl-3-alkylene) oxolane-2, 5-dione, 3-ethyl-4- (pentyl-3-alkylene) oxolane-2, 5-dione, 3-isopropyl-4- (pentyl-2-alkylene) oxolane, and combinations thereof, 3-propyl-4- (pentyl-3-alkylene) oxolane-2, 5-dione, 3-isopropyl-4- (pentyl-3-alkylene) oxolane-2, 5-dione.
The five carbon cuts in the following examples were from naphtha cracking and the specific composition is shown in table 1 below:
TABLE 1
Name (R)
Content (wt%)
Name (R)
Content (wt%)
Other C6 and C6 or more
0.16
1-pentene
4.49
Isobutylene + 1-butene
0.03
2-methyl-1-butene
5.85
1, 3-butadiene
0.20
N-pentane
13.55
N-butane
0.01
Isoprene (I)
20.48
1-butene-3-ynes
0.02
Trans-2-pentene
3.00
Trans-2-butene
0.07
1-pentyne
0.05
1-butyne
0.01
Cis-2-pentene
1.82
Cis-2-butene
0.19
2-methyl-2-butene
2.48
1, 2-butadiene
0.24
Trans-1, 3-pentadienes
8.83
3-methyl-1-butene
0.89
Penteneyne isomers
0.06
3-methyl-1-butyne
0.05
Cyclopentadiene +1, 3-pentadiene
21.19
Isopentane
7.91
Other C4 and below
0.01
1, 4-pentadienes
2.45
Pentadiene + cyclopentadiene
30.01
2-butyne
0.86
C5 conjugated diene + dicyclopentadiene
50.75
Example 1
5kg of maleic anhydride, 0.6kg of a radical initiator (azobisisobutyronitrile) and 10kg of a solvent (xylene) were added to 3kg of the carbon five fraction, and polymerization was carried out under nitrogen protection (polymerization temperature 60 ℃ C., polymerization time 6 hours) to obtain a mixed solution. And (4) centrifuging the mixed solution (the rotation speed of a centrifuge is 4000rpm, and the centrifuging time is 5min), and removing the solid reaction product to obtain a supernatant containing pentane. And distilling and separating the supernatant to obtain pentane. The contents of the respective substances in the supernatant are shown in Table 2.
TABLE 2
Name (R)
Content (wt%)
Name (R)
Content (wt%)
Other C6 and C6 or more
1.67
1-pentene
8.97
Isobutylene + 1-butene
0.28
2-methyl-1-butene
0.62
1, 3-butadiene
1.26
N-pentane
31.26
N-butane
0.07
Isoprene (I)
0.33
1-butene-3-ynes
0.07
Trans-2-pentene
9.17
Trans-2-butene
0.30
1-pentyne
0.00
1-butyne
0.05
Cis-2-pentene
5.11
Cis-2-butene
0.66
2-methyl-2-butene
0.40
1, 2-butadiene
0.78
Trans-1, 3-pentadienes
0.01
3-methyl-1-butene
3.13
Penteneyne isomers
0.00
3-methyl-1-butyne
0.19
Cyclopentadiene +1, 3-pentadiene
0.04
Isopentane
23.99
Other C4 and below
0.15
1, 4-pentadienes
7.13
Pentadiene + cyclopentadiene
0.06
2-butyne
3.34
C5 conjugated diene + dicyclopentadiene
0.38
Examples 2 to 7
The procedure of example 1 was repeated except for the parameters shown in Table 3.
TABLE 3
The present invention is not limited to the above-described embodiments, and any variations, modifications, and substitutions which may occur to those skilled in the art may be made without departing from the spirit of the invention.
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