JP2014091733A - Method for manufacturing paraffin and paraffin manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing paraffin and a paraffin manufacturing apparatus each capable of inhibiting a reaction temperature gain during a hydrogenating reaction for generating paraffin from an olefin and, as a result, of generating a high-purity paraffin by inhibiting the occurrence of the decomposition of the olefin or paraffin at the time of the hydrogenating reaction.SOLUTION: The provided paraffin manufacturing apparatus (100) includes a lead-out unit (2) and a hydrogenating reaction unit (3). A feed olefin, feed hydrogen, and paraffin are drawn out of the lead-out unit (2) and fed into the reaction vessel (31) of the hydrogenating reaction unit (3). Within the reaction vessel (31) of the hydrogenating reaction unit (3), targeted paraffin is generated by inducing, in the presence of a catalyst in a state where the fed paraffin also exists, a hydrogenating reaction based on the contact of the feed olefin and feed hydrogen.

Description

  The present invention relates to a method for producing paraffin such as ethane and propane, and a paraffin production apparatus.

  Propane, which is an example of lower paraffin, is used in the field of semiconductor electronic materials such as application of SiC as a next-generation power device material, and is used in hydrogen-diluted propane gas and propane pure gas. For such applications, propane is required to be of higher purity.

  The source gas mainly composed of propane used as a source of high-purity propane contains high concentrations of ethane, propylene, isobutane, and normal butane as impurities. Examples of the method for purifying propane from this raw material gas include methods such as distillation, membrane separation, adsorption separation, and absorption separation. For example, Patent Document 1 describes that propylene and propane are separated by a distillation method.

  As in the technique described in Patent Document 1, when, for example, propylene and propane are separated by distillation, their boiling points are close (boiling point difference: 4.9 ° C.), and therefore it is necessary to repeat distillation in multiple stages for the separation. There is. Therefore, it is necessary to set a large-scale facility and precise distillation conditions, which is a great barrier to practical use. Similar problems arise when olefins and paraffins having the same carbon number are separated by distillation.

  As a method for solving such a problem, Patent Document 2 describes a method of producing paraffin by bringing a liquid olefin and hydrogen into contact with each other to cause a hydrogenation reaction.

JP 2002-356448 A US Pat. No. 3,509,226

  In the method for producing paraffin described in Patent Document 2, paraffin is produced from olefin by a hydrogenation reaction. Therefore, paraffin can be efficiently produced without performing a complicated operation such as distillation.

  However, in the method for producing paraffin described in Patent Document 2, in the hydrogenation reaction for producing paraffin from olefin, the reaction temperature may rise to a temperature exceeding 200 ° C. In such a case, the olefin or paraffin is decomposed during the hydrogenation reaction, and as a result, there is a problem that high purity paraffin cannot be produced.

  The object of the present invention is to suppress an increase in the reaction temperature in a hydrogenation reaction for producing paraffin from olefin, and as a result, suppress the occurrence of decomposition of olefin or paraffin during the hydrogenation reaction. A paraffin production method and a paraffin production apparatus capable of producing a paraffin having a high purity are provided.

The present invention includes a supply step of supplying raw material olefin, raw material hydrogen and paraffin to the reactor,
A hydrogenation reaction step in which paraffin is produced by bringing the raw material olefin and raw material hydrogen into contact with each other in the presence of the catalyst in the presence of the paraffin in the reactor to cause a hydrogenation reaction. This is a method for producing paraffin.

Moreover, the method for producing paraffin of the present invention includes a reactant supply step of supplying a reactant containing paraffin present in the reactor after the hydrogenation reaction in the hydrogenation reaction step to a partial condenser. ,
In the partial reducer, the reactant is fractionated so that a part of the paraffin in the reactant is liquefied, whereby the liquid phase component and the gas phase component are separated. A partial reduction process derived from the partial reducer;
A recycling supply step of supplying the gas phase component derived from the partial condenser to the reactor as a recycled raw material and paraffin;
And a recovery step of recovering the liquid phase component derived from the partial condenser as a purified paraffin product.

The paraffin production method of the present invention separates impurities from the raw material olefin by bringing the raw material olefin, which is the source of the raw material olefin, into contact with a separator containing silver ions as a pre-process of the supplying step. Olefin purification step to obtain a purified product of olefin,
In the supply step, the purified product of the olefin obtained in the olefin purification step is supplied to the reactor as a raw material olefin.

  In the method for producing paraffin of the present invention, the raw material olefin is an olefin having 2 or 3 carbon atoms.

The present invention also includes a storage unit for storing raw material olefin, raw material hydrogen and paraffin,
A deriving unit for deriving raw material olefin, raw material hydrogen and paraffin from the storage unit, and
The reactor has a reactor to which the raw material olefin, the raw material hydrogen and the paraffin derived from the storage unit are supplied by the deriving unit, and the raw material olefin and the raw material are present in the presence of the catalyst in the state where the paraffin is present in the reactor. A paraffin production apparatus comprising: a hydrogenation reaction unit that generates paraffin by bringing hydrogen into contact with hydrogen.

Further, the paraffin production apparatus of the present invention is a partial reduction section for partial reduction of a reaction product containing paraffin present in the reactor after the hydrogenation reaction is performed in the reactor.
A pressure reducer that separates the reaction product into a liquid phase component and a gas phase component by contracting the reaction product so that a part of the paraffin in the reaction product is liquefied;
A gas phase component deriving unit for deriving the gas phase component separated in the partial pressure reducer from the partial pressure reducer;
A liquid phase component deriving unit for deriving the liquid phase component separated in the partial pressure reducer from the partial pressure reducer;
A recycle supply unit for supplying the vapor phase component derived from the partial condenser by the vapor phase component deriving unit to the reactor as a recycle raw material and paraffin;
And a recovery unit that recovers the liquid phase component derived from the partial condenser by the liquid phase component deriving unit as a purified paraffin product.

Moreover, the paraffin production apparatus of the present invention is an olefin purification unit provided in a preceding stage of the derivation unit, and the raw material olefin, which is the source of the raw material olefin, is brought into contact with a separator containing silver ions. An olefin purification unit for separating impurities from the olefin to obtain a purified product of the olefin;
The derivation unit is characterized in that a purified product of olefin obtained in the olefin purification unit is derived from the storage unit as a raw material olefin.

  According to the present invention, the method for producing paraffin includes a supply step and a hydrogenation reaction step. In the supply step, raw olefin, raw hydrogen and paraffin are supplied to the reactor. In the hydrogenation reaction step, the paraffin is produced by bringing the raw material olefin and the raw material hydrogen into contact with each other in the presence of the catalyst in the presence of the paraffin in the reactor to cause a hydrogenation reaction.

  In the method for producing paraffin of the present invention, the hydrogenation reaction for producing paraffin from the raw olefin in the reactor is carried out in the presence of paraffin from the start of the reaction, so that the increase in reaction temperature is suppressed by sensible heat of paraffin. can do. As a result, it is possible to suppress the decomposition of olefin or paraffin during the hydrogenation reaction in the reactor, and to produce high-purity paraffin.

  Moreover, according to this invention, a paraffin manufacturing apparatus is provided with a storage part, a derivation | leading-out part, and a hydrogenation reaction part. A storage part stores raw material olefin, raw material hydrogen, and paraffin, respectively. The deriving unit derives the raw material olefin, the raw material hydrogen, and the paraffin from the storage unit. The hydrogenation reaction section has a reactor to which the raw material olefin, raw material hydrogen and paraffin derived from the storage section by the deriving section are supplied, and the presence of the catalyst in the state where paraffin is present in the reactor. A paraffin is produced | generated by making a raw material olefin and raw material hydrogen contact under hydrogenation reaction below.

  In the paraffin production apparatus of the present invention, the hydrogenation reaction for producing paraffin from the raw material olefin in the reactor is carried out in the presence of paraffin from the start of the reaction, so that the increase in reaction temperature is suppressed by sensible heat of paraffin. be able to. As a result, it is possible to suppress the decomposition of olefin or paraffin during the hydrogenation reaction in the reactor, and to produce high-purity paraffin.

It is process drawing which shows the process of the manufacturing method of the paraffin which concerns on one Embodiment of this invention. It is a figure which shows the structure of the paraffin manufacturing apparatus 100 which concerns on 1st Embodiment of this invention. It is a figure which shows the structure of the paraffin manufacturing apparatus 100 which concerns on 1st Embodiment of this invention. It is a figure which shows the structure of the paraffin manufacturing apparatus 200 which concerns on 2nd Embodiment of this invention.

  FIG. 1 is a process diagram showing the steps of a method for producing paraffin according to an embodiment of the present invention. The paraffin production method of the present embodiment includes an olefin purification step s1, a raw material supply step s2, a hydrogenation reaction step s3, a reactant supply step s4, a partial reduction step s5, and a recycle supply step s6 shown in FIG. And a recovery step s7. 2A and 2B are diagrams showing the configuration of the paraffin manufacturing apparatus 100 according to the first embodiment of the present invention. The paraffin production apparatus 100 of this embodiment is an apparatus for producing paraffins such as ethane and propane by reducing olefins such as ethylene and propylene.

  The paraffin production apparatus 100 includes an olefin purification unit 1, a derivation unit 2, a hydrogenation reaction unit 3, a partial reduction unit 4, a recovery unit 5, and a gas phase component delivery pump 6 that is a recycling supply unit. The paraffin production apparatus 100 realizes the paraffin production method according to the present invention, wherein the olefin purification unit 1 executes the olefin purification step s1, the derivation unit 2 executes the raw material supply step s2, and the hydrogenation reaction unit 3 The hydrogenation reaction step s3 and the reactant supply step s4 are executed, the partial reduction unit 4 executes the partial reduction step s5, the vapor phase component delivery pump 6 executes the recycle supply step s6, and the recovery unit 5 performs the recovery step s7. Execute.

  The olefin refining unit 1 makes a raw material olefin (hereinafter referred to as “crude olefin”), which is a source of the raw material olefin used in the hydrogenation reaction in the hydrogenation reaction unit 3 to be described later, contact a separator containing silver ions By separating impurities from the crude olefin, a purified product of olefin is obtained. Examples of the separator include a separation membrane doped with silver ions, an adsorbent carrying silver ions, and an absorbing solution containing silver ions. Below, the case where the absorption liquid containing a silver ion is used as a separated body is demonstrated as an example.

  As shown in FIG. 2A, the olefin purification unit 1 includes a crude olefin cylinder 11, an absorption tower 13, a stripping tower 14, a first mist remover 15, a second mist remover 16, and a dehydration tower 18. .

  The crude olefin cylinder 11 is a cylinder filled with a crude olefin containing olefin as a main component as a gas, and the crude olefin gas is sealed under high pressure conditions. Examples of the olefin that is the main component in the crude olefin gas include ethylene, propylene, cyclopropene, 1-butene, 2-butene, and isobutene, but are particularly limited as long as they are gaseous olefins at room temperature (25 ° C.). Is not to be done.

  The present invention is particularly effective when a crude olefin containing as a main component an olefin having 2 or 3 carbon atoms (ethylene, propylene, etc.) is used among the above olefins. When a crude olefin containing an olefin having 2 or 3 carbon atoms as a main component is used, the paraffin production apparatus 100 of the present embodiment produces paraffin (ethane or propane) having 2 or 3 carbon atoms.

The crude olefin gas derived from the crude olefin cylinder 11 is continuously introduced into the absorption tower 13. A crude olefin gas introduction pipe 111 provided with a flow rate regulator 12 is connected between the crude olefin cylinder 11 and the absorption tower 13. The crude olefin gas derived from the crude olefin cylinder 11 is controlled to a predetermined flow rate by the flow rate regulator 12, flows through the crude olefin gas introduction pipe 111, and is introduced into the absorption tower 13. The flow rate of the crude olefin gas introduced into the absorption tower 13 is, for example, 1 to 100 L / sec per 1 m ² of the cross-sectional area of the absorption tower 13.

  The absorption tower 13 is a sealed container having a hollow internal space, and an absorption liquid made of a silver ion-containing solution is stored in the internal space. This absorbing solution is, for example, an aqueous silver nitrate solution prepared to a predetermined concentration. One end of the crude olefin gas introduction pipe 111 is opened in the absorbing solution at the lower part of the absorption tower 13. The crude olefin gas that is led out from the crude olefin cylinder 11 and flows in the crude olefin gas introduction pipe 111 toward the absorption tower 13 flows into the absorbent from the one end of the crude olefin gas introduction pipe 111. In this way, the crude olefin gas comes into contact with the absorbing solution containing silver ions. The crude olefin gas in contact with the absorbing solution is absorbed by the absorbing solution. The solubility of the olefin, which is the main component in the crude olefin gas, in the absorbing solution is considerably larger than the solubility of the impurities (for example, paraffin) in the crude olefin gas in the absorbing solution, so that the olefin is preferentially absorbed by the absorbing solution. The

  About the absorption liquid (for example, silver nitrate aqueous solution) in the absorption tower 13, since the one where the density | concentration is high increases the amount of olefin absorption per unit volume and unit time, it is preferable. From a practical viewpoint, when the olefin is propylene, the concentration of the aqueous silver nitrate solution is, for example, in the range of 1 to 6 mol / L, more preferably 3 to 5 mol / L. As for the temperature of the silver nitrate aqueous solution, the lower the temperature, the more the amount of olefin absorbed, which is advantageous. The internal pressure of the absorption tower 13 is preferably a high pressure within a certain range because the amount of olefin absorbed is increased. From a practical viewpoint, the internal pressure of the absorption tower 13 is, for example, 0.1 to 0.8 MPa (gauge pressure: hereinafter referred to as “(G)”).

  The absorption tower 13 is connected to a first absorbing liquid outlet pipe 112 and a first gas outlet pipe 114. One end of the first absorption liquid lead-out pipe 112 is open in the absorption liquid at the lower part of the absorption tower 13, and the absorption liquid in the absorption tower 13 (absorption liquid in which the crude olefin gas has been absorbed, hereinafter referred to as "crude olefin"). It is a pipe for leading out the gas absorption liquid) to the outside of the tower. The other end of the first absorbent discharge pipe 112 is connected to the absorbent introduction pipe 113. The crude olefin gas absorption liquid derived from the absorption tower 13 and flowing in the first absorption liquid outlet pipe 112 is adjusted to a predetermined flow rate by the flow rate control valve 112A, and the later-described diffusion tower 14 is passed through the absorption liquid introduction pipe 113. To be introduced.

  The first gas outlet pipe 114 is connected to the upper portion of the absorption tower 13 and is a pipe for leading the gas (non-absorbed gas) that has not been absorbed by the absorption liquid stored in the absorption tower 13 to the outside of the tower. is there. One end of the first gas outlet pipe 114 is connected to the upper portion of the absorption tower 13, and the other end is connected to a first mist remover 15 described later. The non-absorbed gas that is led out from the absorption tower 13 and flows in the first gas lead-out pipe 114 is introduced into the first mist remover 15.

  As the absorption tower 13 configured as described above, for example, a known bubble tower, packed tower, wet wall tower, spray tower, scrubber, and plate tower can be employed. The absorption tower 13 is provided with a temperature adjusting device for maintaining the absorption liquid stored in the absorption tower 13 at a desired temperature. For example, the temperature adjusting device allows a temperature control medium made of gas or liquid to flow through a jacket provided around the absorption tower 13.

The crude olefin gas absorption liquid derived from the absorption tower 13 is introduced into the diffusion tower 14 via the absorption liquid introduction pipe 113 due to the pressure difference between the internal pressure of the absorption tower 13 and the internal pressure of the diffusion tower 14. In addition, when the said pressure difference is small, you may make it transfer a crude olefin gas absorption liquid using a pump. The flow rate of the crude olefin gas absorbing liquid introduced into the stripping tower 14 is adjusted by the flow control valve 112A, and is, for example, 0.1 to 10 L / sec per 1 m ^{2 of the} tower cross-sectional area of the stripping tower 14.

  The stripping tower 14 is a sealed container having a hollow internal space, and a predetermined amount of the crude olefin gas absorbing liquid can be accommodated in the internal space. This diffusion tower 14 diffuses the gas component contained in the crude olefin gas absorption liquid accommodated in the internal space. From the viewpoint of efficiently diffusing the gas component, the internal temperature of the diffusion tower 14 is preferably higher than that of the absorption tower 13, and the internal pressure is preferably lower than that of the absorption tower 13. When the olefin is propylene, the temperature of the crude olefin gas absorbent in the stripping tower 14 is preferably 10 to 70 ° C, and more preferably 20 to 70 ° C. When the olefin is propylene, the internal pressure of the stripping tower 14 is preferably, for example, −0.09 to 0.3 MPa (G), and more preferably 0 to 0.3 MPa (G).

  Further, a second gas outlet pipe 115 and a second absorbing liquid outlet pipe 116 are connected to the diffusion tower 14. The second gas outlet pipe 115 is connected to the upper part of the stripping tower 14 and is a pipe for leading out a gas component (hereinafter referred to as “a stripped gas”) released from the crude olefin gas absorption liquid to the outside of the tower. . One end of the second gas outlet pipe 115 is connected to the upper portion of the diffusion tower 14, and the other end is connected to a second mist remover 16 described later. The diffused gas led out from the stripping tower 14 and flowing in the second gas lead-out pipe 115 is introduced into the second mist remover 16.

  One end of the second absorbing liquid outlet pipe 116 is opened in the crude olefin gas absorbing liquid at the lower part of the stripping tower 14, and the crude olefin gas absorbing liquid in the stripping tower 14 (the absorbing liquid from which the gas component has been stripped). , Hereinafter referred to as “gas component emission absorbing liquid”). The other end of the second absorption liquid outlet pipe 116 is connected to an intermediate portion of the first gas outlet pipe 114 of the absorption tower 13 via the pump 17. The gas component emission / absorption liquid derived from the diffusion tower 14 and flowing in the second absorption liquid outlet pipe 116 is sent by the pump 17 and returned to the absorption tower 13 via the first gas outlet pipe 114.

  As the stripping tower 14 configured as described above, a structure in which a crude olefin gas absorbing liquid is dispersed in a liquid is suitable. For example, a known packed tower or spray tower can be employed. In addition, the stripping tower 14 is provided with a temperature adjusting device for maintaining the crude olefin gas absorbent contained in the stripping tower 14 at a desired temperature.

  The non-absorbed gas that is led out from the absorption tower 13 and flows in the first gas lead-out pipe 114 is introduced into the first mist remover 15. The first mist remover 15 separates mist contained in the non-absorbing gas led out from the absorption tower 13. The first mist remover 15 is connected to a gas discharge pipe 117 for guiding the gas that has passed through the first mist remover 15 to the outside of the apparatus. The gas exhaust pipe 117 is provided with a first pressure gauge 117A and a first back pressure valve 117B. The opening degree of the first back pressure valve 117B is controlled so that the inside of the absorption tower 13 has a predetermined pressure.

  The diffused gas led out from the stripping tower 14 and flowing through the second gas lead-out pipe 115 is introduced into the second mist remover 16. The stripped gas introduced into the second mist remover 16 is a stripped olefin from the crude olefin gas absorbing solution in which the olefin in the crude olefin gas has been preferentially absorbed in the absorption tower 13, so that the olefin is removed from the crude olefin gas. Concentration is increasing. The second mist remover 16 separates mist contained in the diffused gas led out from the diffusion tower 14. The second mist remover 16 is connected to a third gas outlet pipe 118 for guiding the gas that has passed through the second mist remover 16 to the dehydration tower 18. The third gas outlet pipe 118 is provided with a second pressure gauge 118A and a second back pressure valve 118B. The opening degree of the second back pressure valve 118B is controlled so that the inside of the diffusion tower 14 becomes a predetermined pressure.

  The dehydration tower 18 is a gas derived from the second mist remover 16 in which mist is removed from the emitted gas (a gas having a higher olefin concentration than the crude olefin gas, hereinafter referred to as “high concentration olefin gas”). Remove moisture contained in The dehydrating tower 18 is filled with an adsorbent that adsorbs moisture. Examples of such an adsorbent include silica gel, alumina, and zeolite. Examples of the zeolite include molecular sieve 3A, molecular sieve 4A, and molecular sieve 13X. The high-concentration olefin gas from which moisture has been adsorbed and removed in the dehydration tower 18 is supplied to a raw material olefin cylinder 21 described later, the impurities contained in the crude olefin gas are reduced in concentration, and the olefin has a high concentration. The resulting high purity olefin. Such high-purity olefin is introduced into the raw material olefin cylinder 21 through a purified olefin outlet pipe 119 connected to the dehydration tower 18.

  According to the olefin purification unit 1 including the crude olefin cylinder 11, the absorption tower 13, the stripping tower 14, the first mist remover 15, the second mist remover 16, and the dehydration tower 18 as described above, In the absorption tower 13, when the crude olefin gas is introduced from the crude olefin cylinder 11 through the crude olefin gas introduction pipe 111, the crude olefin gas comes into contact with the absorbent and is sequentially absorbed by the absorbent. Since the solubility of the olefin in the absorbent is considerably larger than the solubility of the impurities in the crude olefin gas, the olefin that is the main component in the crude olefin gas is preferentially absorbed by the absorbent. Therefore, as the injected crude olefin gas rises while being absorbed in the absorption liquid, the olefin concentration decreases in the gas, while the impurity concentration increases.

  On the other hand, as for the absorption liquid in the absorption tower 13, the absorption liquid (crude olefin gas absorption liquid) that has absorbed the crude olefin gas in the absorption tower 13 passes through the first absorption liquid outlet pipe 112 from the lower part of the absorption tower 13. Then, the absorption liquid (gas component diffusion absorption liquid) that has flowed out of the absorption tower 13 at a predetermined flow rate and diffused the gas component in the diffusion tower 14 is sent by the pump 17 and is passed through the first gas outlet pipe 114. Then, the gas is returned from the upper part of the absorption tower 13 into the absorption tower 13. As a result, a downward flow occurs in the absorption liquid in the absorption tower 13. Accordingly, the crude olefin gas introduced into the absorption tower 13 from the crude olefin gas introduction pipe 111 is in countercurrent contact with the absorption liquid flowing downward in the absorption tower 13 and is not absorbed by the absorption liquid due to the contact. The gas blows into the upper space of the absorption tower 13. The non-absorbed gas is sent to the first mist remover 15 through the first gas outlet pipe 114, and after the liquid component is separated and removed, it is discharged out of the system through the gas discharge pipe 117. . On the other hand, the liquid component separated by the first mist remover 15 falls as droplets through the first gas outlet pipe 114 and is returned to the absorption tower 13.

  In this way, in the absorption tower 13, the raw olefin gas continuously supplied comes into contact with the absorbing liquid, whereby the olefin in the crude olefin gas is preferentially absorbed by the absorbing liquid, while the non-absorbing gas is It is discharged outside the tower.

  In the stripping tower 14, the gas component in the crude olefin gas absorbent derived from the absorption tower 13 is stripped. The emitted gas diffused from the crude olefin gas absorption liquid is sent to the second mist remover 16 via the second gas outlet pipe 115, and after the liquid component is removed, the gas is removed via the third gas outlet pipe 118. Water is adsorbed and removed by being sent to the dehydration tower 18 and supplied to the raw material olefin cylinder 21 as high-purity olefin.

  In the stripping tower 14, the absorption liquid from which the gas component has been diffused is sent to the first gas lead-out pipe 114 by the pump 17 through the second absorption liquid lead-out pipe 116, and then falls into the absorption tower 13. At this time, the flow rate of the absorption liquid sent out by the pump 17 is set to be approximately the same as the flow rate of the absorption liquid flowing from the absorption tower 13 to the diffusion tower 14. Thereby, the absorption liquid in the absorption tower 13 and the absorption liquid in the diffusion tower 14 circulate in a balanced manner.

  In this way, in the stripping tower 14, the gas component of the absorption liquid that continues to flow at a predetermined flow rate is diffused and the stripped gas is led out of the tower, and is passed through the dehydration tower 18 to the raw material olefin cylinder 21 as high-purity olefin. Will be supplied.

  For example, when the crude olefin gas derived from the crude olefin cylinder 11 is an industrial gas mainly composed of propylene, the crude olefin gas includes propane as main impurities, oxygen, nitrogen, carbon dioxide as trace impurities. , Ethane, butane and so on. When the crude olefin gas mainly composed of propylene is purified by the olefin purification unit 1, saturated hydrocarbons are removed.

  That is, when the crude olefin gas derived from the crude olefin cylinder 11 is directly introduced into the hydrogenation reaction section 3 without being purified by the olefin purification section 1, the hydrogenation reaction is performed. Saturated hydrocarbons such as impurities, ethane, and butane remain as they are, and high-purity propane cannot be produced.

  On the other hand, in the paraffin production apparatus 100 of the present embodiment, the high-purity raw material olefin purified by the olefin purification unit 1 is hydrogenated by the hydrogenation reaction unit 3. The impurity concentration of the high-purity raw material olefin purified by the olefin purification unit 1 (when the olefin is propylene) is, for example, propane from 5000 ppm to 100 ppm, as in the examples described later.

  In the present embodiment, since the high-purity raw material olefin having an extremely low impurity concentration as described above is hydrogenated in the hydrogenation reaction unit 3, high-purity paraffin can be generated.

  The deriving unit 2 is a unit for deriving the high-purity raw material olefin, raw material hydrogen and paraffin purified in the olefin purifying unit 1 toward the hydrogenation reaction unit 3 described later. As shown in FIG. 2B, the derivation unit 2 is configured to derive the raw material olefin, the raw material hydrogen, and the paraffin from the raw material olefin cylinder 21, the paraffin cylinder 22, and the raw material hydrogen cylinder 23 that function as a storage unit. .

  The raw material olefin cylinder 21 is a cylinder filled with a high-purity raw material olefin, which is derived from the dehydration tower 18 of the olefin purification unit 1 and flows through the purified olefin outlet pipe 119 and is supplied as a gas under high pressure conditions. Olefin gas is enclosed.

  The raw material olefin cylinder 21 is connected to a raw material olefin outlet pipe 211 provided with a flow rate regulator 24, a first pressure reducing valve 211A, and a first on-off valve 211B. The first opening / closing valve 211B is a valve that opens / closes or closes the flow path of the raw material olefin outlet pipe 211. With the first on-off valve 211B opened, the raw material olefin gas led out from the raw material olefin cylinder 21 is set to a predetermined pressure by the first pressure reducing valve 211A and further controlled to a predetermined flow rate by the flow rate regulator 24. It flows through the raw material olefin outlet pipe 211 and is introduced into the hydrogenation reaction section 3 through the mixing pipe 311. The raw material olefin introduced into the hydrogenation reaction section 3 is preferably adjusted so that the space velocity SV is 10 to 10,000 / h, more preferably 10 to 1000 / h. It is particularly preferable to adjust to 500 / h.

  The paraffin cylinder 22 is a cylinder filled with paraffin as gas or liquefied gas, and paraffin gas is sealed under high pressure conditions. The paraffin filled in the paraffin cylinder 22 is paraffin having the same carbon number as that of the raw material olefin introduced into the hydrogenation reaction unit 3. For example, the raw material olefin introduced into the hydrogenation reaction unit 3 has carbon number. In the case of 3 propylene, the paraffin filled in the paraffin cylinder 22 is propane having 3 carbon atoms.

  The paraffin cylinder 22 is connected to a paraffin outlet pipe 212 provided with a flow rate regulator 25, a second pressure reducing valve 212A, and a second on-off valve 212B. The second on-off valve 212B is a valve that opens and closes or closes the flow path of the paraffin outlet pipe 212. With the second on-off valve 212B opened, the paraffin gas led out from the paraffin cylinder 22 is brought to a predetermined pressure by the second pressure reducing valve 212A, and further controlled to a predetermined flow rate by the flow rate regulator 25 to derive the paraffin. It flows through the pipe 212 and is introduced into the hydrogenation reaction section 3 via the mixing pipe 311. The paraffin introduced into the hydrogenation reaction unit 3 is preferably adjusted so that the space velocity SV is 10 to 10,000 / h, more preferably 10 to 1000 / h, and more preferably 10 to 500. It is particularly preferable to adjust to / h.

  The source hydrogen cylinder 23 is a cylinder filled with source hydrogen as a gas, and hydrogen gas is sealed under high pressure conditions. The purity of the hydrogen gas charged in the raw material hydrogen cylinder 23 is 99 to 99.99999 mol%, preferably 99.999 mol% or more. When the purity of the hydrogen gas used for the hydrogenation reaction of the high-purity raw material olefin is low, the concentration of other impurities is high in the resulting mixed gas of paraffin and hydrogen.

  A hydrogen outlet pipe 213 provided with a flow rate regulator 26, a third pressure reducing valve 213A and a third on-off valve 213B is connected to the raw material hydrogen cylinder 23. The third on-off valve 213B is a valve that opens and closes or closes the flow path of the hydrogen outlet pipe 213. With the third on-off valve 213B opened, the hydrogen gas led out from the raw material hydrogen cylinder 23 is brought to a predetermined pressure by the third pressure reducing valve 213A, and further controlled to a predetermined flow rate by the flow rate regulator 26. It flows through the outlet pipe 213 and is introduced into the hydrogenation reaction section 3 via the mixing pipe 311. The raw material hydrogen introduced into the hydrogenation reaction unit 3 is preferably adjusted so that the space velocity SV is 10 to 10,000 / h, more preferably 10 to 1000 / h. It is particularly preferable to adjust to 500 / h.

  The raw material olefin flowing in the raw material olefin outlet pipe 211, the paraffin flowing in the paraffin outlet pipe 212, and the hydrogen gas flowing in the hydrogen outlet pipe 213 are mixed in the mixing pipe 311 and introduced into the hydrogenation reaction unit 3. The

  The hydrogenation reaction unit 3 includes a reactor 31 to which the raw material olefin, the raw material hydrogen, and the paraffin derived from the raw material olefin cylinder 21, the paraffin cylinder 22, and the raw material hydrogen cylinder 23 are supplied by the derivation unit 2.

  The reactor 31 is a sealed container having a hollow internal space, and the internal space is filled with a catalyst. In addition, a temperature adjusting device for maintaining the inside of the reactor 31 at a desired temperature is attached to the reactor 31. In the reactor 31, in the presence of paraffin, the raw material olefin and the raw material hydrogen are brought into contact with each other in the presence of the catalyst to cause a hydrogenation reaction to generate paraffin.

  The catalyst charged in the reactor 31 is not particularly limited as long as it is a reduction catalyst. For example, palladium (Pd), rhodium (Rh), platinum (Pt), ruthenium (Ru), and nickel A catalyst containing at least one selected from (Ni) is preferred, and a catalyst containing palladium (Pd) is particularly preferred. By performing a hydrogenation reaction of a high-purity raw material olefin in the presence of such a catalyst, the efficiency of the hydrogenation reaction can be improved, and the productivity of high-purity paraffin can be improved.

  In addition, you may make it fill in the reactor 31 in the state which mixed the alumina ball | bowl, the ceramic ball | bowl, etc., and the catalyst. As a result, heat generation accompanying the hydrogenation reaction in the reactor 31 can be suppressed, so that the reaction temperature can be kept constant.

  In the reactor 31, the space velocity SV of the raw olefin, raw hydrogen and paraffin is preferably 10 to 10000 / h, more preferably 10 to 1000 / h, and 10 to 500 / h. It is particularly preferred. If the space velocity SV is too small, the amount of catalyst used increases and the cost increases. When the space velocity SV is too large, there is a possibility that sufficient hydrogenation is not performed so that the olefin is transformed into paraffin.

  In the reactor 31, the molar ratio of the raw material olefin to the raw material hydrogen is preferably raw material olefin / raw material hydrogen = 1 / 1.1 to 1/10, preferably 1 / 1.5 to 1/10. More preferably. When the molar ratio of the raw material hydrogen to the raw material olefin is too small, there is a possibility that the hydrogenation for changing the olefin to paraffin may not be performed sufficiently. When the molar ratio of the raw material hydrogen to the raw material olefin is too large, a large amount of unreacted hydrogen gas remains in the produced paraffin.

  In the reactor 31, the molar ratio of the raw material olefin and paraffin is preferably raw material olefin / paraffin = 1/5 to 1/30, and more preferably 1/10 to 1/25. When the molar ratio of the paraffin to the raw material olefin is too small, the effect of suppressing heat generation due to the hydrogenation reaction in the reactor 31 is not sufficient. If the molar ratio of paraffin to raw olefin is too large, the amount of paraffin produced by the hydrogenation reaction of raw olefin will be too small.

  Moreover, it is preferable that the temperature in the reactor 31 is 0-200 degreeC, and it is especially preferable that it is 50-150 degreeC. When the temperature is too low, the hydrogenation reaction using the catalyst is difficult to proceed. If the temperature is too high, olefin decomposition may occur.

  In the paraffin manufacturing apparatus 100 of this embodiment, since the hydrogenation reaction which produces | generates paraffin from the raw material olefin in the reactor 31 is performed in presence of paraffin, it can suppress the raise of reaction temperature with the sensible heat which paraffin has. it can.

  For example, in the reactor 31, when propylene as a raw material olefin is hydrogenated in the presence of a palladium catalyst to produce propane, the molar ratio of propylene to hydrogen gas is propylene / hydrogen = 1 / 1.1. When the reaction occurs instantaneously, the reaction temperature becomes about 900 ° C. Furthermore, when the reaction temperature becomes high, decomposition of propylene or propane occurs on the surface of the palladium catalyst, and several vol% of methane and ethane are generated in the reaction product.

  In contrast, when propylene is hydrogenated in the presence of a palladium catalyst, if propane is coexisted in the reaction system as paraffin from the start of the hydrogenation reaction, specifically, propylene / hydrogen / propane = 1 / When the hydrogenation reaction is started in a state where propylene, hydrogen and propane coexist at a molar ratio of 1.1 / 25, the reaction temperature can be suppressed to 75 ° C. Thus, since the rise in reaction temperature can be suppressed, the occurrence of decomposition of propylene or propane can be suppressed, and the concentrations of methane and ethane in the reaction product can each be suppressed to 5 ppm or less.

  Moreover, it is preferable that the pressure in the reactor 31 is 0.0-2.0 MPa (G). For example, when propane is produced by hydrogenation reaction of propylene as a raw material olefin in the reactor 31, the pressure in the reactor 31 is preferably 0.05 to 0.7 MPa (G). The hydrogenation reaction generally tends to be promoted under high-pressure conditions. However, when the pressure is too low, a large amount of reaction heat is generated, which becomes an obstacle for stabilizing the reaction temperature. On the other hand, if the pressure is too high, the raw material olefin and paraffin may not be vaporized and may be stored in the reactor 31 in a liquid state, which is not preferable.

  The gaseous reactant containing paraffin present in the reactor 31 after the hydrogenation reaction in the reactor 31 flows through the reactant outlet tube 312 functioning as the reactant outlet, and the partial reduction section 4. To be introduced.

  The partial reduction unit 4 includes a partial condenser 41, a gas phase component derivation tube 411 that functions as a gas phase component derivation unit, and a liquid phase component derivation tube 413 that functions as a liquid phase component derivation unit.

  The partial reducer 41 reduces the gaseous reactant that flows through the reactant outlet tube 312 and is supplied into the partial reducer 41. Specifically, the partial reducer 41 separates the reactant into a liquid phase component and a gas phase component so that a part of the paraffin in the reactant is liquefied.

  As the condenser 41, a multi-tube heat exchanger, a double-tube heat exchanger, a glass lining heat exchanger, a coil heat exchanger, a spiral heat exchanger, a plate heat exchanger, a trombone heat An exchanger, an impervious graphite heat exchanger, or the like can be used.

  As the material of the partial reducer 41, cast iron, SUS304, SUS316, SUS316L, or the like can be suitably used. Further, glass materials such as glass, heat-resistant glass, and quartz glass can be suitably used, and materials obtained by coating these materials on the metal surface, such as glass lining materials, can also be used for the divider 41.

  The setting condition in the partial condenser 41 is not particularly limited as long as a part of the paraffin in the reaction product is liquefied, but the partial temperature is set to about -35 ° C to 15 ° C. Is preferred. When the partial shrinkage temperature is less than -35 ° C, a special cryogen for lowering the temperature is required, which results in an increase in energy costs for cooling it, which is not preferable. Further, if the partial temperature exceeds 15 ° C., the pressure of the gas phase component is increased, and a pressure-resistant facility is required, which is not preferable. The partial temperature in the partial condenser 41 is maintained at a predetermined temperature using the refrigerant circulator 42.

  Moreover, it is preferable that the pressure in the partial pressure device 41 is 0.05-0.3 MPa (G). The pressure in the partial condenser 41 is monitored by the third pressure gauge 41A.

  By the partial reduction operation in the partial condenser 41, a part of the paraffin in the gaseous reactant is liquefied by partial condensation to become a liquid phase component, and the part that has not been liquefied remains as a gas and becomes a gas phase component. . A gas phase component outlet tube 411, a gas phase component outlet tube 412, and a liquid phase component outlet tube 413 are connected to the partial condenser 41.

  The gas phase component outlet pipe 411 is a pipe having one end connected to the condenser 41 and the other end connected to the mixing pipe 311. A gas phase component delivery pump 6 that functions as a recycling supply unit is connected to the gas phase component outlet tube 411 between one end and the other end. The gas phase component derivation pipe 411 is provided with a flow rate regulator 43, a fourth on-off valve 411A, and a fifth on-off valve 411B. A fourth on-off valve 411A is provided between the flow rate regulator 43 and the fifth on-off valve 411B between the gas phase component delivery pump 6 and the mixing pipe 311.

  The gas phase component separated by the partial condenser 41 includes some paraffin, hydrogen, olefin, and the like contained in the reaction product. The gas phase component delivery pump 6 transfers the gas phase component that is led out from the partial condenser 41 and flows in the gas phase component lead-out pipe 411 toward the reactor 31 as a recycled raw material and paraffin, and the recycled raw material and paraffin Is fed to the reactor 31.

  Examples of the gas phase component delivery pump 6 include a reciprocating pump and a rotary pump. The recycling supply unit for supplying the gas phase component derived from the partial condenser 41 to the reactor 31 as a recycle raw material and paraffin is not limited to the pump type gas phase component delivery pump 6. For example, a blower such as a turbo blower, a volume blower, a centrifugal fan, a mixed flow fan, an axial fan, a reciprocating compressor (reciprocating compressor), a screw compressor, a diaphragm compressor, or a centrifugal compressor may be used.

  The gas phase components (recycled raw material and paraffin) derived from the divider 41 are adjusted in flow rate by the flow rate regulator 43 in a state where the fourth on-off valve 411A and the fifth on-off valve 411B are opened. It flows through the phase component outlet pipe 411 and the mixing pipe 311 and is introduced into the reactor 31. The recycled material and paraffin introduced into the reactor 31 in this way are used for the hydrogenation reaction in the reactor 31. Therefore, the amount of raw olefin derived from the raw olefin cylinder 21 and supplied to the reactor 31, the amount of paraffin derived from the paraffin cylinder 22 and supplied to the reactor 31, and derived from the raw hydrogen cylinder 23 to the reactor The amount of hydrogen supplied to 31 is adjusted according to the amount of olefin, paraffin and hydrogen contained in the recycled raw material and paraffin introduced into the reactor 31.

  The gas phase component discharge pipe 412 is a pipe having one end connected to the divider 41 and the other end opened to the external space. The gas phase component discharge pipe 412 is provided with a sixth on-off valve 412A for opening or closing the flow path of the gas phase component discharge pipe 412. The sixth on-off valve 412A is opened in a state where the fourth on-off valve 411A provided in the gas-phase component outlet pipe 411 is closed, so that the gas-phase component of the divider 41 is transferred into the gas-phase component discharge pipe 412. And discharged to the outside of the apparatus.

  The liquid phase component outlet tube 413 is a pipe having one end connected to the condenser 41 and the other end connected to the recovery container 51 of the recovery unit 5. The liquid phase component outlet pipe 413 is provided with a seventh on-off valve 413A that opens or closes the flow path of the liquid phase component outlet pipe 413.

  The liquid phase component separated by the condenser 41 is purified paraffin. By opening the seventh on-off valve 413A, the purified paraffin product, which is the liquid phase component of the partial reducer 41, flows in the liquid phase component outlet pipe 413 and is led out from the partial reducer 41 toward the recovery container 51. Will be.

  The collection unit 5 has a collection container 51. The recovery container 51 uses the liquid phase component of the partial condenser 41 that is led out from the partial condenser 41 and flows in the liquid phase component outlet pipe 413 as a purified product of liquid paraffin (hereinafter referred to as “purified paraffin”). It is a container for collecting and storing the purified paraffin. The internal temperature of the recovery container 51 is maintained at a predetermined temperature using the refrigerant circulator 52.

  In addition, the recovery container 51 stores liquid purified paraffin so that a gas phase is formed above the recovery container 51. A recovery gas phase component outlet pipe 511 and a recovery gas phase component discharge pipe 512 are connected to the upper part of the recovery container 51 on the gas phase side.

  The recovery gas phase component outlet pipe 511 is a pipe having one end connected to the recovery container 51 and the other end connected to the mixing pipe 311. The recovery gas phase component outlet tube 511 is provided with an eighth on-off valve 511A for opening or closing the flow path of the recovery gas phase component outlet tube 511 and a flow rate regulator 53.

  The liquid purified paraffin stored in the collection container 51 may contain hydrogen or the like as a low boiling point substance. Such low-boiling substances such as hydrogen contained in the purified paraffin are concentrated in the vapor phase in the recovery container 51 held at a predetermined temperature by the refrigerant circulator 52.

  By opening the eighth on-off valve 511A provided in the recovered gas phase component outlet pipe 511, the gas phase component formed in the upper part of the recovery container 51 is recovered in the recovered gas phase while the flow rate is adjusted by the flow rate regulator 53. It flows through the component outlet pipe 511 and is supplied to the reactor 31 via the mixing pipe 311. Thus, the gas phase component of the recovery container 51 introduced into the reactor 31 is used for the hydrogenation reaction in the reactor 31.

  The recovered gas phase component discharge pipe 512 is a pipe having one end connected to the recovery container 51 and the other end opened to the external space. The recovery gas phase component discharge pipe 512 is provided with a ninth on-off valve 512A that opens or closes the flow path of the recovery gas phase component discharge pipe 512. The ninth on-off valve 512A is opened while the eighth on-off valve 511A provided in the recovery gas phase component outlet pipe 511 is closed, so that the gas phase component in the recovery container 51 is recovered into the recovery gas phase component discharge pipe 512. It flows inside and is discharged outside the apparatus.

  As described above, in the paraffin production apparatus 100 of the present embodiment, the high-purity olefin purified by the olefin purification unit 1 is contacted with hydrogen in the presence of paraffin and catalyst in the reactor 31 to perform a hydrogenation reaction. By this, high purity paraffin can be obtained.

  Further, since the hydrogenation reaction in the reactor 31 is performed in the presence of paraffin derived from the paraffin cylinder 22 and supplied to the reactor 31, an increase in the reaction temperature can be suppressed. The occurrence of paraffin decomposition can be suppressed.

  Further, the reaction product obtained by the hydrogenation reaction in the reactor 31 is separated into a liquid phase component and a gas phase component by the partial condenser 41, and the liquid phase component is recovered in the recovery container 51 as purified paraffin. High-purity paraffin can be obtained.

  Furthermore, the paraffin production apparatus 100 is configured such that the gas phase component of the partial condenser 41 and the gas phase component of the recovery container 51 are introduced into the reactor 31, and thus included in each gas phase component. Olefin, paraffin and hydrogen can be reused as raw materials for the hydrogenation reaction.

  FIG. 3 is a diagram showing a configuration of a paraffin manufacturing apparatus 200 according to the second embodiment of the present invention. The paraffin manufacturing apparatus 200 of this embodiment is similar to the paraffin manufacturing apparatus 100 described above, and corresponding portions are denoted by the same reference numerals and description thereof is omitted. The paraffin manufacturing apparatus 200 is different from the above-described paraffin manufacturing apparatus 100 in the configuration of the recycling supply unit. The paraffin manufacturing apparatus 100 includes a gas phase component delivery pump 6 as a recycling supply unit, whereas the paraffin manufacturing apparatus 200 includes a gas ejector 201 as a recycling supply unit. The paraffin production apparatus 200 includes the olefin purification unit 1 as in the paraffin production apparatus 100, but the olefin purification unit 1 is omitted in FIG.

  The gas ejector 201 is provided between the outlet 2 and the reactor 31 in the mixing pipe 311. Further, the gas ejector 201 is connected to the other end of the gas phase component outlet tube 411 opposite to the side connected to the partial condenser 41.

  The gas ejector 201 supplies the reactor 31 with the gas phase component of the partial condenser 41 that is derived from the partial condenser 41 and flows in the gas phase component outlet pipe 411. The gas ejector 201 is a vacuum pump that uses an injection gas flow as a drive source and does not have a mechanical drive unit, and a commercially available one can be used. By using such a gas ejector 201 that does not have a mechanical drive unit as a recycle supply unit, it is possible to introduce a recycled material and paraffin with reduced impurity contamination into the reactor 31.

  Hereinafter, the present invention will be described in more detail based on examples. However, the present invention is not limited to such examples.

Example 1
<Production of high purity propylene>
Industrial propylene (manufactured by Mitsui Chemicals, purity 99.5%) was purified by supplying it to the olefin purification section shown in FIG. 2A using an aqueous silver nitrate solution as an absorbing solution. Specifically, stainless steel cylindrical tubes (inner diameter 54.9 mm × height 500 mm, volume 1185 mL) were used as an absorption tower and a dissipating tower each consisting of a bubble tower. The absorption tower stores 735 mL of a 5 mol / L silver nitrate aqueous solution (absorption liquid level height 310 mm), and the diffusion tower stores 355 mL of the same concentration of silver nitrate aqueous solution (absorption liquid level height 150 mm). It was.

  The conditions in the absorption tower were an internal pressure of 0.5 MPa (G) and an internal temperature of 25 ° C. The conditions for the stripping tower were an internal pressure of 0.1 MPa (G) and an internal temperature of 25 ° C. The aqueous silver nitrate solution stored in the absorption tower and the diffusion tower was circulated so that the flow rate was 25 mL / min. In the stripping tower, stripped gas (purified propylene gas) was derived at 637 mL / min, the recovery rate was 96.1 mol%, and the purity was 99.99 mol%. In the absorption tower, non-absorbed gas was discharged at 26 mL / min, and the discharge rate was 3.9 mol%.

  The purified high purity propylene thus obtained was used as a raw material propylene to be supplied to the reactor.

<Propane production>
A stainless steel cylindrical tube (inner diameter 12.4 mm × height 100 mm) was used as the reactor. The reactor was charged with 10 mL of Pd (0.5 wt%) / Al ₂ O ₃ catalyst (N1182AZ, manufactured by JGC Catalysts & Chemicals). The raw material propylene gas (purity 99.99 mol%) purified as described above is supplied to this reactor at a flow rate of 40 mL / min (indicating a value converted to a flow rate at NTP, 0 ° C., 1 atm). The raw material hydrogen gas (Sumitomo Seika Co., Ltd., EG grade, purity 99.9999 mol%) is supplied at a flow rate of 60 mL / min (NTP), and propane gas (AGT, purity 99.999 mol%) is supplied. It was supplied at a flow rate of 400 mL / min (NTP). The molar ratio of each gas in the reactor was propylene / hydrogen / propane = 2/3/20 (= 1 / 1.5 / 10). As hydrogenation reaction conditions in the reactor, the internal pressure was set to 0.3 MPa (G).

<Result>
The reaction temperature during the hydrogenation reaction in the reactor was 100 ° C. Further, the reaction product derived from the reactor after the hydrogenation reaction was a gas mainly composed of propane. When the concentration of impurities contained in this reaction product was analyzed by gas chromatography (FID), the propylene concentration was 1 volppm or less, and the methane and ethane concentrations were 1 volppm or less, respectively.

(Example 2)
<Production of high purity propylene>
In the same manner as in Example 1, purified high-purity propylene was obtained, and this high-purity propylene was used as raw material propylene to be supplied to the reactor.

<Propane production>
A stainless steel cylindrical tube (inner diameter 12.4 mm × height 100 mm) was used as the reactor. The reactor was charged with 10 mL of Rh (0.5 wt%) / Al ₂ O ₃ catalyst (Aldrich). The raw material propylene gas (purity 99.99 mol%) purified as described above is supplied to this reactor at a flow rate of 40 mL / min (NTP), and raw material hydrogen gas (purity 99.9999 mol%) is supplied at a flow rate of 60 mL. Propane gas (purity 99.999 mol%) was supplied at a flow rate of 200 mL / min (NTP). The molar ratio of each gas in the reactor was propylene / hydrogen / propane = 2/3/10 (= 1 / 1.5 / 5). As hydrogenation reaction conditions in the reactor, the internal pressure was set to 0.3 MPa (G).

<Result>
The reaction temperature during the hydrogenation reaction in the reactor was 200 ° C. Further, the reaction product derived from the reactor after the hydrogenation reaction was a gas mainly composed of propane. When the concentration of impurities contained in this reaction product was analyzed by gas chromatography (FID), the propylene concentration was 2 volppm, the methane concentration was 4 volppm, and the ethane concentration was 6 volppm.

(Example 3)
<Manufacture of high purity ethylene>
Ethylene (manufactured by Sumitomo Seika Co., Ltd., PURE grade, purity 99.9%) was supplied to the olefin purification section shown in FIG. 2A using a silver nitrate aqueous solution as the absorbing solution for purification. The absorption tower stores 237 mL of a 3 mol / L silver nitrate aqueous solution (the liquid level height of the absorbing solution is 100 mm), and the diffusion tower stores 355 mL of the same concentration silver nitrate aqueous solution (the liquid surface height of the absorbing solution is 150 mm). It was.

  The conditions in the absorption tower were an internal pressure of 0.5 MPa (G) and an internal temperature of 25 ° C. The conditions for the stripping tower were an internal pressure of 0.1 MPa (G) and an internal temperature of 40 ° C. The aqueous silver nitrate solution stored in the absorption tower and the diffusion tower was circulated so that the flow rate was 25 mL / min. In the stripping tower, the stripped gas (purified ethylene gas) was derived at 760 mL / min, the recovery rate was 95.0 mol%, and the purity was 99.99 mol%. In the absorption tower, non-absorbed gas was discharged at 40 mL / min, and the discharge rate was 5.0 mol%.

  The purified high-purity ethylene thus obtained was used as raw ethylene to be supplied to the reactor.

<Ethane production>
A stainless steel cylindrical tube (inner diameter 12.4 mm × height 100 mm) was used as the reactor. The reactor was charged with 10 mL of Pd (0.5 wt%) / Al ₂ O ₃ catalyst (N1182AZ, manufactured by JGC Catalysts & Chemicals). The raw material ethylene gas (purity 99.99 mol%) purified as described above is supplied to this reactor at a flow rate of 40 mL / min (NTP), and raw material hydrogen gas (purity 99.9999 mol%) is supplied at a flow rate of 60 mL. Ethane gas (manufactured by Sumitomo Seika Co., Ltd., purity 99.9 mol% or more) was supplied at a flow rate of 200 mL / min (NTP). The molar ratio of each gas in the reactor was ethylene / hydrogen / ethane = 2/3/10 (= 1 / 1.5 / 5). As hydrogenation reaction conditions in the reactor, the internal pressure was set to 0.3 MPa (G).

<Result>
The reaction temperature during the hydrogenation reaction in the reactor was 100 ° C. In addition, the reaction product derived from the reactor after the hydrogenation reaction was a gas mainly composed of ethane. When the concentration of impurities contained in the reaction product was analyzed by gas chromatography (FID), the ethylene concentration was 1 volppm or less, and methane was not detected.

(Example 4)
<Production of high purity propylene>
In the same manner as in Example 1, purified high-purity propylene was obtained, and this high-purity propylene was used as raw material propylene to be supplied to the reactor.

<Propane production>
Reaction with propane as main component in the same manner as in Example 1 except that the molar ratio of propylene, hydrogen and propane gas in the reactor was changed to propylene / hydrogen / propane = 1 / 1.1 / 10. I got a thing.

<Result>
The reaction temperature during the hydrogenation reaction in the reactor was 100 ° C. Further, the reaction product derived from the reactor after the hydrogenation reaction was a gas mainly composed of propane. When the concentration of impurities contained in this reaction product was analyzed by gas chromatography (FID), the propylene concentration was 1 volppm or less, the methane concentration was 4 volppm, and the ethane concentration was 3 volppm.

(Example 5)
<Production of high purity propylene>
In the same manner as in Example 1, purified high-purity propylene was obtained, and this high-purity propylene was used as raw material propylene to be supplied to the reactor.

<Propane production>
Reaction with propane as main component in the same manner as in Example 1 except that the molar ratio of propylene, hydrogen, and propane gas in the reactor was changed to propylene / hydrogen / propane = 1 / 1.3 / 10. I got a thing.

<Result>
The reaction temperature during the hydrogenation reaction in the reactor was 100 ° C. Further, the reaction product derived from the reactor after the hydrogenation reaction was a gas mainly composed of propane. When the concentration of impurities contained in this reaction product was analyzed by gas chromatography (FID), the propylene concentration was 1 volppm or less, and the methane and ethane concentrations were 1 volppm or less, respectively.

(Example 6)
<Production of high purity propylene>
In the same manner as in Example 1, purified high-purity propylene was obtained, and this high-purity propylene was used as raw material propylene to be supplied to the reactor.

<Propane production>
A stainless steel cylindrical tube (inner diameter 12.4 mm × height 100 mm) was used as the reactor. The reactor was charged with 10 mL of Pd (0.5 wt%) / Al ₂ O ₃ catalyst (N1182AZ, manufactured by JGC Catalysts & Chemicals). The raw material propylene gas (purity 99.99 mol%) purified as described above is supplied to this reactor at a flow rate of 40 mL / min (NTP), and raw material hydrogen gas (purity 99.9999 mol%) is supplied at a flow rate of 60 mL. Propane gas (purity 99.999 mol%) was supplied at a flow rate of 400 mL / min (NTP). The molar ratio of each gas in the reactor was propylene / hydrogen / propane = 2/3/20 (= 1 / 1.5 / 10). As hydrogenation reaction conditions in the reactor, the internal pressure was set to 0.3 MPa (G).

Further, the reaction product derived from the reactor after the hydrogenation reaction was supplied to a partial condenser (heat transfer area 130 cm ² , manufactured by SUS304). In this partial condenser (temperature: −25 ° C., pressure: 0.1 MPa (G)), the reaction product was fractionated so that a part of the propane in the reaction product was liquefied. The liquid phase component in the partial condenser was recovered as a purified product of propane in a recovery container, and liquid propane (4 L) was stored in the recovery container. In addition, a diaphragm pump was used as a recycling supply unit, and the gas phase components in the partial condenser were supplied to the reactor as recycled materials and propane. It should be noted that as the operating condition of the partial reducer, the outlet flow rate of the partial reducer relative to the inlet flow rate of the partial reducer (reactant supply flow rate derived from the reactor) (recycled toward the reactor as a gas phase component). The percentage (condenser cut rate) of the used raw material and the flow rate of propane was set to 2%.

<Result>
The reaction temperature during the hydrogenation reaction in the reactor was 100 ° C. Also, the operation of the paraffin production apparatus is continued for 6 hours, and after 6 hours, the concentration of impurities contained in the gas phase component formed on the upper part of the recovery container in which liquid propane is stored is measured by gas chromatography (FID). The propylene concentration was 1 volppm or less, the methane concentration was 2 volppm, and the ethane concentration was 1 volppm or less.

  In addition, in a state where liquid propane is stored in the recovery container, the ninth on-off valve provided in the recovery gas phase component discharge pipe is opened, and a part of the gas phase component formed in the upper part of the recovery container Was discharged outside the apparatus. Thereafter, the ninth on-off valve was closed, and the concentration of impurities contained in the gas phase component formed in the upper part of the recovery container was analyzed by gas chromatography (FID). As a result, the methane concentration was 1 volppm or less.

(Example 7)
<Production of high purity propylene>
In the same manner as in Example 1, purified high-purity propylene was obtained, and this high-purity propylene was used as raw material propylene to be supplied to the reactor.

<Propane production>
Liquid propane was recovered in a recovery container in the same manner as in Example 6 except that a gas ejector (91-07u, manufactured by Nakajima Copper Works Co., Ltd.) was used instead of the diaphragm pump as the recycle supply unit.

<Result>
The reaction temperature during the hydrogenation reaction in the reactor was 100 ° C. Also, the operation of the paraffin production apparatus is continued for 6 hours, and after 6 hours, the concentration of impurities contained in the gas phase component formed on the upper part of the recovery container in which liquid propane is stored is measured by gas chromatography (FID). The propylene concentration was 1 volppm or less, the methane concentration was 2 volppm, and the ethane concentration was 1 volppm or less.

  In addition, in a state where liquid propane is stored in the recovery container, the ninth on-off valve provided in the recovery gas phase component discharge pipe is opened, and a part of the gas phase component formed in the upper part of the recovery container Was discharged outside the apparatus. Thereafter, the ninth on-off valve was closed, and the concentration of impurities contained in the gas phase component formed in the upper part of the recovery container was analyzed by gas chromatography (FID). As a result, the methane concentration was 1 volppm or less.

(Comparative Example 1)
<Production of high purity propylene>
In the same manner as in Example 1, purified high-purity propylene was obtained, and this high-purity propylene was used as raw material propylene to be supplied to the reactor.

<Propane production>
A stainless steel cylindrical tube (inner diameter 12.4 mm × height 100 mm) was used as the reactor. The reactor was charged with 10 mL of Pd (0.5 wt%) / Al ₂ O ₃ catalyst (N1182AZ, manufactured by JGC Catalysts & Chemicals). The raw material propylene gas (purity 99.99 mol%) purified as described above is supplied to this reactor at a flow rate of 40 mL / min (NTP), and raw material hydrogen gas (purity 99.9999 mol%) is supplied at a flow rate of 60 mL. / Min (NTP). In Comparative Example 1, propane gas was not supplied by the hydrogenation reaction. The molar ratio of each gas in the reactor was propylene / hydrogen = 2/3 (= 1 / 1.5). As hydrogenation reaction conditions in the reactor, the internal pressure was set to 0.3 MPa (G).

<Result>
The reaction temperature during the hydrogenation reaction in the reactor was 350 ° C., and the increase in the reaction temperature could not be suppressed. Further, the reaction product derived from the reactor after the hydrogenation reaction was a gas mainly composed of propane. When the concentration of impurities contained in this reaction product was analyzed by gas chromatography (FID), the methane concentration was 800 volppm and the ethane concentration was 600 volppm. The propylene concentration was not measurable because the detection peak overlapped with propane.

  As is clear from the evaluation results of Examples 1 to 7 and Comparative Example 1, the hydrogenation reaction in the reactor is performed in the presence of paraffin from the start of the reaction, thereby suppressing an increase in the reaction temperature. As a result, it is possible to suppress the occurrence of olefin or paraffin decomposition and to obtain high-purity paraffin.

DESCRIPTION OF SYMBOLS 1 Olefin refining part 2 Deriving part 3 Hydrogenation reaction part 4 Partial reduction part 5 Recovery part 6 Gas phase component delivery pump 31 Reactor 41 Partial reduction apparatus 51 Recovery container 100,200 Paraffin production apparatus 201 Gas ejector

Claims (7)

A supply step of supplying raw material olefin, raw material hydrogen and paraffin to the reactor;
A hydrogenation reaction step in which paraffin is produced by bringing the raw material olefin and raw material hydrogen into contact with each other in the presence of the catalyst in the presence of the paraffin in the reactor to cause a hydrogenation reaction. To produce paraffin. A reactant supply step of supplying a reactant containing paraffin present in the reactor after the hydrogenation reaction is performed in the hydrogenation reaction step to a partial condenser;
In the partial reducer, the reactant is fractionated so that a part of the paraffin in the reactant is liquefied, whereby the liquid phase component and the gas phase component are separated. A partial reduction process derived from the partial reducer;
A recycling supply step of supplying the gas phase component derived from the partial condenser to the reactor as a recycled raw material and paraffin;
The method for producing paraffin according to claim 1, further comprising a recovery step of recovering the liquid phase component derived from the fractionator as a purified paraffin product. As a pre-process of the supplying step, an olefin purification step for obtaining a purified product of olefin by separating impurities from the raw material olefin by bringing the raw material olefin, which is the source of the raw material olefin, into contact with a separator containing silver ions Including
3. The method for producing paraffin according to claim 1, wherein in the supply step, the purified product of the olefin obtained in the olefin purification step is supplied to the reactor as a raw material olefin.   The method for producing paraffin according to any one of claims 1 to 3, wherein the raw material olefin is an olefin having 2 or 3 carbon atoms. A storage section for storing raw material olefin, raw material hydrogen and paraffin;
A deriving unit for deriving raw material olefin, raw material hydrogen and paraffin from the storage unit, and
The reactor has a reactor to which the raw material olefin, the raw material hydrogen and the paraffin derived from the storage unit are supplied by the deriving unit, and the raw material olefin and the raw material are present in the presence of the catalyst in the state where the paraffin is present in the reactor. A paraffin production apparatus, comprising: a hydrogenation reaction unit that produces paraffin by bringing hydrogen into contact with hydrogen. A partial reduction section for partial reduction of a reaction product containing paraffin present in the reactor after a hydrogenation reaction is performed in the reactor;
A pressure reducer that separates the reaction product into a liquid phase component and a gas phase component by contracting the reaction product so that a part of the paraffin in the reaction product is liquefied;
A gas phase component deriving unit for deriving the gas phase component separated in the partial pressure reducer from the partial pressure reducer;
A liquid phase component deriving unit for deriving the liquid phase component separated in the partial pressure reducer from the partial pressure reducer;
A recycle supply unit for supplying the vapor phase component derived from the partial condenser by the vapor phase component deriving unit to the reactor as a recycle raw material and paraffin;
The paraffin production apparatus according to claim 5, further comprising: a recovery unit that recovers the liquid phase component derived from the partial condenser by the liquid phase component deriving unit as a purified paraffin product. An olefin purification unit provided in a preceding stage of the lead-out unit, wherein the raw material olefin, which is the source of the raw material olefin, is brought into contact with a separator containing silver ions to separate impurities from the raw material raw olefin. It further comprises an olefin purification section for obtaining a purified product,
The paraffin production apparatus according to claim 5 or 6, wherein the derivation unit derives a purified product of the olefin obtained in the olefin purification unit from the storage unit as a raw material olefin.

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