JP7208838B2 - Method for producing dicyclopentadiene and isoprene - Google Patents

Description

The present invention relates to a method for producing dicyclopentadiene and isoprene.

Conventionally, various utilization methods have been proposed for hydrocarbons having 5 carbon atoms. For example, isoprene is in high demand as a main component of synthetic rubber and the like, and is widely used industrially. Isoprene can be obtained, for example, by recovering by extractive distillation from a C5 fraction mainly composed of hydrocarbons having 5 carbon atoms, which is a by-product when naphtha is thermally cracked to produce ethylene. Further, Patent Document 1 describes that isoamylene is recovered from the extraction residue of the extractive distillation, and isoprene is produced by subjecting the isoamylene to a dehydrogenation reaction.

JP 2015-151391 A

However, in the method described in Patent Document 1, the remaining hydrocarbon having 5 carbon atoms after recovering the isoamylene becomes a loss. Therefore, a manufacturing process that enables more effective use of resources is expected.

An object of the present invention is to provide a method for producing dicyclopentadiene and isoprene, which is capable of producing industrially useful isoamylene from a hydrocarbon having 5 carbon atoms and simultaneously producing industrially useful dicyclopentadiene. With the goal.

One aspect of the present invention is to obtain a first mixture containing the normal form and a second mixture containing the iso form from a raw material mixture containing the normal form and the iso form of a hydrocarbon having 5 carbon atoms. a first dehydrogenation step of contacting said first mixture with a cyclized dehydrogenation catalyst to obtain a first product containing cyclopentadiene; said second mixture and a dehydrogenation catalyst; to obtain a second product containing isoprene, and from a third mixture containing said first product and said second product, cyclopentadiene and a recovery step to obtain dicyclopentadiene and isoprene by dimerization and extractive distillation.

In one aspect, the third mixture may further contain a C5 fraction mainly composed of hydrocarbons having 5 carbon atoms. At this time, the recovery step may be a step of obtaining a raw material mixture containing dicyclopentadiene, isoprene, and a normal form and an iso form of a hydrocarbon having 5 carbon atoms.

The raw material mixture obtained in the recovery step can be used as the raw material mixture in the separation step.

In one aspect, the recovering step comprises dimerizing cyclopentadiene by heating the third mixture to obtain dicyclopentadiene and a fourth mixture containing isoprene (A-1); and obtaining isoprene by extractive distillation of the fourth mixture (A-2).

In one embodiment, the recovery step comprises extractive distillation of the third mixture to obtain a fifth mixture containing isoprene and cyclopentadiene (B-1), and heating the fifth mixture. and a step (B-2) of dimerizing cyclopentadiene to obtain dicyclopentadiene.

INDUSTRIAL APPLICABILITY According to the present invention, a method for producing dicyclopentadiene and isoprene is provided, in which industrially useful isoamylene can be produced from a hydrocarbon having 5 carbon atoms while simultaneously producing industrially useful dicyclopentadiene. be done.

Preferred embodiments of the present invention are described in detail below.

In the production method according to the present embodiment, a raw material mixture containing a normal isomer and an iso isomer of a hydrocarbon having 5 carbon atoms is converted into a first mixture containing the normal isomer and a second mixture containing the iso isomer. a first dehydrogenation step of contacting said first mixture with a cyclization dehydrogenation catalyst to obtain a first product containing cyclopentadiene; said second mixture and dehydration a second dehydrogenation step to obtain a second product containing isoprene by contacting with a hydrogen catalyst; a recovery step of obtaining dicyclopentadiene and isoprene by dimerization and extractive distillation of pentadiene.

According to the production method according to the present embodiment, industrially useful isoamylene and dicyclopentadiene can be co-produced from a hydrocarbon having 5 carbon atoms.

Each step of the manufacturing method according to this embodiment will be described in detail below.

<Separation process>
In the separation step, a first mixture containing a normal form and a second mixture containing an iso form are obtained from a raw material mixture containing a normal form and an iso form of a hydrocarbon having 5 carbon atoms.

Normal hydrocarbons having 5 carbon atoms include n-pentane, 1-pentene, 2-pentene, 1,3-pentadiene and 1,4-pentadiene.

Iso-isomers of hydrocarbons having 5 carbon atoms include isopentane, 2-methyl-1-butene, 2-methyl-2-butene, and 3-methyl-1-butene.

In the raw material mixture, the molar ratio of the iso-isomer to the normal-isomer may be, for example, 0.1-10, preferably 0.2-5, more preferably 0.5-2.

In the separation step, the method of separating the first mixture and the second mixture from the raw material mixture is not particularly limited. Any separation method can be used. Among them, membrane separation is preferable as the separation method from the viewpoint of productivity, apparatus scale and energy consumption rate.

The separation membrane used for membrane separation is not particularly limited as long as it can separate the raw material mixture into the first mixture and the second mixture, and polymer membranes, inorganic membranes, carbon membranes, etc. can be used. can. Among them, from the viewpoint of heat resistance and chemical resistance, inorganic membranes are preferable, ceramic membranes, metal membranes and alloy membranes are more preferable, ceramic membranes are still more preferable, and zeolite membranes such as silicalite membranes are particularly preferable.

Membrane separation can be performed using any type of membrane separation module, such as a flat plate type, a tubular type, a laminated flat plate type, and a multi-tube type. Among them, from the viewpoint of separation efficiency and downsizing of the device, a flat plate or multitubular membrane separation module is preferable, and from the viewpoint of ease of replacement of the separation membrane, a multitubular separation membrane module is preferred. is more preferable.

The first mixture may be a mixture containing the normal form as a main component (for example, 70% by mass or more). The amount of the normal form in the first mixture is preferably 80% by mass or more, more preferably 90% by mass or more, and may be 100% by mass.

The second mixture may be a mixture containing iso isomers as a main component (for example, 70% by mass or more). The amount of the isoform in the second mixture is preferably 80% by mass or more, more preferably 90% by mass or more, and may be 100% by mass.

<First dehydrogenation step>
The first dehydrogenation step is a step of contacting the first mixture with a cyclized dehydrogenation catalyst to obtain a first product containing cyclopentadiene. In the first dehydrogenation step, cyclopentadiene is produced by a cyclic dehydrogenation reaction of the normal form in the first mixture.

The cyclization dehydrogenation catalyst and the conditions of the cyclization dehydrogenation reaction are not particularly limited, and any catalyst and conditions capable of converting at least part of the normal form to cyclopentadiene can be used without particular limitation.

The cyclization dehydrogenation catalyst may have, for example, a support and an active metal supported on the support.

As the carrier, an inorganic carrier is preferred, and an inorganic oxide carrier is more preferred. Further, the carrier preferably contains at least one element selected from the group consisting of Al, Mg, Si, Zr, Ti and Ce, and contains at least one element selected from the group consisting of Al, Mg and Si. It is more preferable to include

A preferred embodiment of the cyclization dehydrogenation catalyst is shown below.

The cyclization dehydrogenation catalyst of this embodiment is a catalyst in which a carrier containing Al and a Group 2 metal element is supported with a supported metal containing a Group 14 metal element and Pt. Here, the Group 2 metal element means a metal element belonging to Group 2 of the periodic table in the periodic table of long-period elements based on the IUPAC (International Union of Pure and Applied Chemistry) regulations, and Group 14 metal element The term means a metal element belonging to Group 14 of the periodic table of the long-period periodic table of elements according to the IUPAC (International Union of Pure and Applied Chemistry) regulations.

The Group 2 metal element may be, for example, at least one selected from the group consisting of beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr) and barium (Ba). Among these, the Group 2 metal element is preferably Mg.

The Group 14 metal element may be, for example, at least one selected from the group consisting of germanium (Ge), tin (Sn) and lead (Pb). Among these, the Group 14 metal element is preferably Sn.

The cyclization dehydrogenation catalyst may be a cyclization dehydrogenation catalyst other than those described above. For example, a suitable example of a cyclization dehydrogenation catalyst other than the above is a catalyst using Cr as a supported metal in the above embodiment.

The conditions for the cyclization dehydrogenation reaction are not particularly limited, and for example, the reaction temperature may be 300 to 800°C, 400 to 700°C, or 500 to 650°C. If the reaction temperature is 300° C. or higher, the amount of cyclopentadiene produced tends to increase. If the reaction temperature is 800° C. or lower, the coking rate does not become too high, so the high activity of the cyclization dehydrogenation catalyst tends to be maintained for a longer period of time. The reaction pressure, ie, the atmospheric pressure in the reactor, may be 0.01-1 MPa, 0.05-0.8 MPa, or 0.1-0.5 MPa. If the reaction pressure is within the above range, the dehydrogenation reaction tends to proceed more easily, and a more excellent reaction efficiency tends to be obtained.

Further, when the cyclization dehydrogenation reaction is carried out in a continuous reaction format in which the raw material gas is continuously supplied, the weight hourly space velocity (hereinafter referred to as “WHSV”) is, for example, 0.1 h ⁻¹ or more. It may be 0.5h ⁻¹ or more. Also, the WHSV may be 20h ⁻¹ or less, or may be 10h ⁻¹ or less. Here, WHSV is the ratio (F/W) of the supply rate (supply amount/time) F of the source gas (first mixture) to the weight W of the cyclization dehydrogenation catalyst. A WHSV of 0.1 h ⁻¹ or more allows a smaller reactor size. When the WHSV is 20h ⁻¹ or less, the yield of cyclopentadiene can be further increased. The amounts of the raw material gas and the catalyst used may be appropriately selected in a more preferable range according to the reaction conditions, the activity of the catalyst, etc., and the WHSV is not limited to the above range.

The reaction format of the cyclodehydrogenation reaction may be, for example, fixed bed, moving bed or fluidized bed. Among these, the fixed bed type is preferable from the viewpoint of facility cost.

The first product contains cyclopentadiene produced by the cyclization dehydrogenation reaction. The first product may further contain a component other than cyclopentadiene, for example, may further contain a normal form that has not been cyclized.

<Second dehydrogenation step>
The second dehydrogenation step is contacting the second mixture with a dehydrogenation catalyst to obtain a second product containing isoprene. In the second dehydrogenation step, isoprene is produced by the dehydrogenation reaction of the isoform in the second mixture.

The dehydrogenation catalyst and the conditions of the dehydrogenation reaction are not particularly limited, and any catalyst and conditions capable of converting at least a part of the isoform to isoprene can be used without particular limitation.

As the dehydrogenation catalyst, for example, a catalyst (hereinafter also referred to as a first dehydrogenation catalyst) in which a supported metal containing a Group 14 metal element and Pt is supported on a support containing Al and a Group 2 metal element is used. can be used. Here, the Group 2 metal element means a metal element belonging to Group 2 of the periodic table of long period elements based on the regulations of IUPAC (International Union of Pure and Applied Chemistry). The Group 14 metal element means a metal element belonging to Group 14 of the periodic table of long period elements based on the IUPAC (International Union of Pure and Applied Chemistry) regulations.

Mg is particularly suitable as the Group 2 metal element, and Sn is particularly suitable as the Group 14 metal element.

As the dehydrogenation catalyst, for example, a catalyst in which tin and an active metal are supported on an inorganic oxide carrier (hereinafter also referred to as a second dehydrogenation catalyst) can be used. As the active metal, platinum, ruthenium, iridium, etc. can be preferably used.

In the second dehydrogenation step, the dehydrogenation reaction may be performed using either one of the first dehydrogenation catalyst and the second dehydrogenation catalyst, and the first dehydrogenation catalyst and the second dehydrogenation catalyst You may perform a dehydrogenation reaction using both.

Conditions for the dehydrogenation reaction in the second dehydrogenation step are not particularly limited, for example, the reaction temperature may be 300 to 800°C, 400 to 700°C, or 500 to 650°C. . If the reaction temperature is 300° C. or higher, the amount of isoprene produced tends to increase. If the reaction temperature is 800° C. or lower, the coking rate does not become too high, so the high activity of the dehydrogenation catalyst tends to be maintained for a longer period of time. The reaction pressure, ie the air pressure in the reactor, may be 0.01-1 MPa, 0.05-0.8 MPa, or 0.1-0.5 MPa. If the reaction pressure is within the above range, the dehydrogenation reaction tends to proceed more easily, and a more excellent reaction efficiency tends to be obtained.

Further, when the dehydrogenation reaction in the second dehydrogenation step is performed in a continuous reaction format in which the source gas is continuously supplied, the weight hourly space velocity (hereinafter referred to as “WHSV”) is, for example, 0.1 h ⁻ It may be ¹ or more, and may be 0.5 h ⁻¹ or more. Also, the WHSV may be 20h ⁻¹ or less, or may be 10h ⁻¹ or less. Here, WHSV is the ratio (F/W) of the supply rate (supply amount/time) F of the source gas (second mixture) to the mass W of the dehydrogenation catalyst. A WHSV of 0.1 h ⁻¹ or more allows a smaller reactor size. When the WHSV is 20 h ⁻¹ or less, the conversion to isoprene can be made higher. The amounts of the raw material gas and the catalyst used may be appropriately selected in a more preferable range according to the reaction conditions, the activity of the catalyst, etc., and the WHSV is not limited to the above range.

The reaction format of the second dehydrogenation reaction may be, for example, fixed bed, moving bed or fluidized bed. Among these, the fixed bed type is preferable from the viewpoint of facility cost.

The second product contains isoprene resulting from the dehydrogenation reaction. The second product may further contain components other than isoprene, for example, may further contain isoforms other than isoprene.

<Recovery process>
The recovery step is a step of obtaining dicyclopentadiene and isoprene by dimerization and extractive distillation of cyclopentadiene from a third mixture containing the first product and the second product.

A third mixture contains cyclopentadiene and isoprene, the cyclopentadiene being converted to dicyclopentadiene by a dimerization reaction and recovered, and the isoprene being recovered by extractive distillation. The third mixture may further contain hydrocarbons with 5 carbon atoms other than cyclopentadiene and isoprene, and the hydrocarbons with 5 carbon atoms are separated in the separation step described above after recovery of dicyclopentadiene and isoprene. It can be used as a raw material mixture.

The third mixture may further contain, in addition to the first product and the second product, a C5 fraction mainly composed of hydrocarbons having 5 carbon atoms. As a result, cyclopentadiene and isoprene in the C5 fraction are recovered by dimerization and extractive distillation, and hydrocarbons with 5 carbon atoms other than cyclopentadiene and isoprene in the C5 fraction are effectively used as raw material compounds in the above separation step. can be used well. That is, by blending the C5 fraction with the third mixture, the reaction cycle consisting of the separation step, the first dehydrogenation step, the second dehydrogenation step and the recovery step can be added to the normal isomer and the iso isomer that are the raw material components. can be introduced efficiently.

The C5 fraction contains hydrocarbons with 5 carbon atoms as a main component (for example, 70% by mass or more). The amount of hydrocarbons having 5 carbon atoms in the C5 fraction is preferably 80% by mass or more, more preferably 90% by mass or more.

The C5 fraction may be, for example, a C5 fraction produced by thermal cracking of naphtha, or a light hydrocarbon mixture derived from a heavy oil catalytic cracker.

The C5 fraction preferably contains both normal and iso-isomers of hydrocarbons having 5 carbon atoms. The molar ratio of the iso-isomer to the normal-isomer in the C5 fraction is not particularly limited, but may be, for example, 0.2-5, preferably 0.5-2.

The C5 cut may additionally contain cyclopentadiene. In this case, industrially useful dicyclopentadiene is produced from the cyclopentadiene by dimerization in the recovery step.

The C5 fraction may further contain isoprene. In this case, industrially useful isoprene is recovered by extractive distillation in the recovery step.

In the recovery step, the order of dimerization and extractive distillation is not limited. In one preferred embodiment, the recovery step may be a step of dimerizing cyclopentadiene in the third mixture to obtain dicyclopentadiene and then recovering isoprene by extractive distillation. In another preferred embodiment, the recovery step is a step of recovering isoprene and cyclopentadiene by extractive distillation of the third mixture and dimerizing the recovered cyclopentadiene to obtain dicyclopentadiene. good. Each aspect will be described in detail below.

(First aspect)
In the first aspect, the recovery step includes dimerizing cyclopentadiene by heating the third mixture to obtain dicyclopentadiene and a fourth mixture containing isoprene (A-1); and obtaining isoprene by extractive distillation of the fourth mixture (A-2).

In step (A-1), cyclopentadiene in the third mixture is dimerized to obtain dicyclopentadiene. In addition, components other than cyclopentadiene are supplied to the subsequent step (A-2) as a fourth mixture.

In step (A-2), isoprene is recovered by extractive distillation of the fourth mixture. In addition, the fourth mixture may contain a hydrocarbon having 5 carbon atoms other than isoprene, and the hydrocarbon having 5 carbon atoms is reused as a raw material mixture in the separation step described above after extractive distillation. .

The conditions for the dimerization reaction in step (A-1) are not particularly limited, and any conditions can be used without particular limitation as long as they are capable of dimerizing cyclopentadiene to produce dicyclopentadiene. Dimerization of cyclopentadiene is preferably carried out using a Diels-Alder reaction from the viewpoint of suppressing multimerization of cyclopentadiene and reaction efficiency, and a Diels-Alder reaction in a liquid phase using a non-catalytic continuous reactor is performed. It is more preferable to use The residence time of the hydrocarbon mixture when performing the Diels-Alder reaction using a continuous reactor is preferably 0.5 hours or longer, more preferably 1 hour or longer, and 6 hours or shorter. preferably 4 hours or less. By setting such a residence time, the dimerization reaction can be sufficiently advanced, side reactions between cyclopentadiene and isoprene, piperylene, etc. can be suppressed, and dicyclopentadiene can be obtained more efficiently. can.

The reaction temperature of the dimerization reaction in step (A-1) is preferably 50° C. or higher, more preferably 60° C. or higher, preferably 250° C. or lower, and preferably 150° C. or lower. more preferred. By setting it as such reaction temperature, a dimerization reaction can fully be advanced and the above-mentioned side reaction can be suppressed, and a dicyclopentadiene can be obtained more efficiently.

Dicyclopentadiene produced by the dimerization reaction may be recovered from the reaction mixture by a method such as distillation separation. In addition, components other than dicyclopentadiene in the mixture after the reaction are recovered as a fourth mixture and supplied to step (A-2).

Conditions for the extractive distillation in step (A-2) are not particularly limited as long as the conditions are such that isoprene can be separated and recovered. The extractive distillation in step (A-2) can be carried out, for example, by a method such as extractive separation using an extractant containing dimethylformamide or the like.

Components other than isoprene in the fourth mixture can be recovered and used as a raw material mixture in the separation step.

(Second aspect)
In a second aspect, the recovery step includes step (B-1) of obtaining a fifth mixture containing isoprene and cyclopentadiene by extractive distillation of the third mixture, and heating the fifth mixture. and dimerizing cyclopentadiene to obtain dicyclopentadiene (B-2).

In step (B-1), isoprene and a fifth mixture containing cyclopentadiene are each recovered by extractive distillation of the third mixture. The third mixture may contain hydrocarbons with 5 carbon atoms other than isoprene and cyclopentadiene, and the hydrocarbons with 5 carbon atoms are reused as a raw material mixture in the separation step described above after extractive distillation. be.

In step (B-2), dicyclopentadiene is obtained by a dimerization reaction of the cyclopentadiene recovered in step (B-1).

Conditions for the extractive distillation in step (B-1) are not particularly limited as long as cyclopentadiene and isoprene can be separated and recovered. The extractive distillation in step (B-1) can be carried out, for example, by a method such as extractive separation using an extractant containing acetonitrile, n-methylpyrrolidone, or the like.

Components other than cyclopentadiene and isoprene in the third mixture can be recovered and used as a raw material mixture for the separation step.

Conditions for the dimerization reaction in step (B-2) are not particularly limited, and any conditions that can dimerize cyclopentadiene to form dicyclopentadiene can be used without particular limitations. Dimerization of cyclopentadiene is preferably carried out using a Diels-Alder reaction from the viewpoint of suppressing multimerization of cyclopentadiene and reaction efficiency, and a Diels-Alder reaction in a liquid phase using a non-catalytic continuous reactor is performed. It is more preferable to use The residence time of the hydrocarbon mixture when performing the Diels-Alder reaction using a continuous reactor is preferably 0.5 hours or longer, more preferably 1 hour or longer, and 6 hours or shorter. preferably 4 hours or less. By setting it as such a residence time, a dimerization reaction can fully be advanced and a side reaction can be suppressed and a dicyclopentadiene can be obtained more efficiently.

The reaction temperature of the dimerization reaction in step (B-2) is preferably 50° C. or higher, more preferably 60° C. or higher, preferably 250° C. or lower, and preferably 150° C. or lower. more preferred. By setting it as such reaction temperature, a dimerization reaction can fully be advanced and a side reaction can be suppressed and a dicyclopentadiene can be obtained more efficiently.

Dicyclopentadiene produced by the dimerization reaction may be recovered from the reaction mixture by a method such as distillation separation.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments.

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples.

(Example 1)
Using the C5 fraction having the composition shown in Table 1, a reaction cycle including the following separation step, first dehydrogenation step, second dehydrogenation step and recovery step was investigated.
The C5 fraction having the composition shown in Table 1 is mixed with the first product obtained in the first dehydrogenation step described below and the second product obtained in the second dehydrogenation step described below, It is provided for the recovery process. In the recovery step, dicyclopentadiene and isoprene are recovered by dimerization and extractive distillation of cyclopentadiene, and other C5 fractions are supplied to the separation step described later.
In the separation step, the C5 fraction that has undergone the recovery step is separated into a first mixture containing the normal form and a second mixture containing the iso form. The first mixture is subjected to the first dehydrogenation step described below, and the second mixture is subjected to the second dehydrogenation step described below.
In the first dehydrogenation step, the first mixture is contacted with a cyclized dehydrogenation catalyst to yield a first product containing cyclopentadiene. In a second dehydrogenation step, the second mixture is contacted with a dehydrogenation catalyst to yield a second product containing isoprene. The first product and the second product are supplied to the recovery step as described above, whereby the normal form in the C5 fraction is circulated to dicyclopentadiene and the iso form to isoprene in the system.

In the above reaction cycle, the yield of dicyclopentadiene and isoprene recovered through the recovery step (yield (mass %) relative to the amount of the C5 fraction used as the raw material) was determined. Table 2 shows the results.

(Comparative example 1)
A reaction system in which only the recovery process is performed was investigated.
That is, in the reaction system of Comparative Example 1, the C5 fraction having the composition shown in Table 1 is subjected to dimerization of cyclopentadiene and extractive distillation to recover dicyclopentadiene and isoprene. The remainder after recovery of dicyclopentadiene and isoprene is purged out of the system.

The yield of dicyclopentadiene and isoprene recovered in such a reaction system (yield (mass %) with respect to the amount of C5 fraction used as a raw material) was determined. Table 2 shows the results.

(Comparative example 2)
A reaction cycle without the first dehydrogenation step was investigated.
That is, in Comparative Example 2, the C5 fraction having the composition shown in Table 1 was mixed with the second product obtained in the second dehydrogenation step described later and supplied to the recovery step. In the recovery step, dicyclopentadiene and isoprene are recovered by dimerization and extractive distillation of cyclopentadiene, and other C5 fractions are supplied to the separation step described later.
In the separation step, the C5 fraction that has undergone the recovery step is separated into a first mixture containing the normal form and a second mixture containing the iso form. The first mixture is purged out of the system. The second mixture is subjected to the second dehydrogenation step described below.
v In the second dehydrogenation step, the second mixture is contacted with a dehydrogenation catalyst to obtain a second product containing isoprene. The second product is supplied to the recovery step as described above, whereby the isoform in the C5 fraction circulates in the system until it becomes isoprene.

The yield of dicyclopentadiene and isoprene recovered in such a reaction cycle (yield (% by mass) relative to the amount of C5 fraction used as a starting material) was determined. Table 2 shows the results.

Claims (5)

A separation step of obtaining a first mixture containing the normal form and a second mixture containing the iso form from a raw material mixture containing the normal form and the iso form of a hydrocarbon having 5 carbon atoms;
a first dehydrogenation step of contacting the first mixture with a cyclization dehydrogenation catalyst to obtain a first product containing cyclopentadiene;
a second dehydrogenation step of contacting the second mixture with a dehydrogenation catalyst to obtain a second product containing isoprene;
a recovery step of obtaining dicyclopentadiene and isoprene from a third mixture containing said first product and said second product by dimerization and extractive distillation of cyclopentadiene;
A method for producing dicyclopentadiene and isoprene, comprising: The third mixture further contains a C5 fraction mainly composed of hydrocarbons having 5 carbon atoms,
2. The production method according to claim 1, wherein the recovering step is a step of obtaining a raw material mixture containing dicyclopentadiene, isoprene, and a normal form and an iso form of a hydrocarbon having 5 carbon atoms. 3. The production method according to claim 2, wherein the raw material mixture obtained in the recovery step is used as the raw material mixture in the separation step. The recovery step includes
a step (A-1) of dimerizing cyclopentadiene by heating the third mixture to obtain dicyclopentadiene and a fourth mixture containing isoprene;
obtaining isoprene by extractive distillation of said fourth mixture (A-2);
The production method according to any one of claims 1 to 3, comprising The recovery step includes
obtaining a fifth mixture containing isoprene and cyclopentadiene by extractive distillation of said third mixture (B-1);
a step (B-2) of dimerizing cyclopentadiene by heating the fifth mixture to obtain dicyclopentadiene;
The production method according to any one of claims 1 to 3, comprising