The present invention relates to a process of preparing dialkylnaphthylenes and polyalkylenenaphthyleneates dialkylnaphthalenes and polyalkylenenaphthalates.
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25. A process for producing 2,6-dialkylnaphthalene from a feedstock, comprising the following steps:
I. separating said feedstock into a fraction comprising naphthalene, a fraction comprising monoalkynaphthalene monoalkylnaphthalene and a fraction comprising dialkylnaphthalene;
II. separating said purifying 2,6-dialkylnaphthalene from said dialkylnaphthalene fraction of step I to produce 2,6-dialkylnaphthalene and a second dialkylnaphthalene fraction;
iii. dealkylating said second dialkylnaphthalene fraction produced in step II;
IIIa. recycling the product of step iii to step I; and
IV. alkylating said fractions comprising naphthalene and comprising monoalkynaphthalene monoalkylnaphthalene of step I.
22. A process for producing 2,6-dialkylnaphthalene from a feedstock, comprising the following steps:
I. separating said feedstock into a fraction comprising naphthalene and monoalkynaphthalene monoalkylnaphthalene and a fraction comprising dialkylnaphthalene;
II. separating and purifying 2,6-dialkylnaphthalene from said dialkylnaphthalene fraction of step I to produce 2,6-dialkylnaphthalene and a second dialkynaphthalene dialkylnaphthalene fraction;
iii. dialkylating said naphthalene and monoalkynaphthalene monoalkylnaphthalene fraction of step I and said second dialkylnaphthalene fraction produced in step II;
IV. separating a naphthalene and monoalkynaphthalene monoalkylnaphthalene fraction from said dialkylation product of step iii;
v. alkylating said naphthalene and monoalkynaphthalene monoalkylnaphthalene fraction of step IV; and
VI. recycling a product from step v to step I.
24. A process for producing 2,6-dialkylnaphthalene from a feedstock, comprising the following steps:
I. separating said feedstock into a fraction comprising naphthalene, a fraction comprising monoalkynaphthalene monoalkylnaphthalene, a fraction comprising dialkylnaphthalene and a fraction comprising remaining products;
II. separating and purifying 2,6-dialkylnaphthalene from said dialkylnaphthalene fraction of step I to produce 2,6-dialkylnaphthalene and a second dialkylnaphthalene fraction;
IIa. dealkylating second dialkylnaphthalene fraction produced in step II and recycling the product of dealkylation to step I;
iii. dealkylating said fraction comprising remaining products of step I and recycling a product of dealkylation to step I;
IV. alkylating said fractions comprising naphthalene and comprising monoalkynaphthalene monoalkylnaphthalene of step I.
1. A process for producing 2,6-dialkylnaphthalene from a feedstock, comprising the following steps:
I. separating said feedstock into a naphthalene, monoalkynaphthalene monoalkylnaphthalene, and dialkylnaphthalene fractions:
II. separating and purifying 2,6-dialkylnaphthalene from said dialkylnaphthlane dialkylnaphthalene fraction of step I to produce 2,6-dialkylnaphthalene and a second dialkylnaphthalene fraction;
iii. alkylating said monoalkylnaphthalene fraction of step I with an alkylating agent to produce dialkylnaphthalene and recycling the dialkylnaphthalene to step I;
IV. transalkylating said naphthalene fraction of step I and said second dialkylnaphthalene fraction produced in step II, to produce monoaIkylnaphthalene monoalkylnaphthalene, and isomers of dialkylnaphthalene; wherein said monoalkynaphthalene monoalkylnaphthalene fraction produced in step I is cracked before step iii, or in step iii, or after step iii.
26. A process for producing 2,6-dialkylnaphthalene from a feedstock, comprising the following steps:
I. separating said feedstock into a fraction comprising naphthalene, a fraction comprising monoalkynaphthalene monoalkylnaphthalene, a fraction comprising dialkylnaphthalene and a fraction lean in dialkylnaphthalene;
II. separating and purifying 2,6-dialkylnaphthalene from said dialkylnaphthalene fraction of step I to produce 2,6-dialkylnaphthalene and a second dialkylnaphthalene fraction;
IIa. isomerizing said fraction lean in dialkylnaphthalene of step I;
iib. separating the isomerization product of step IIa into a fraction comprising dialkylnaphthalene and a fraction lean in dialkylnaphthalene;
IIc. recycling a dialkylnaphthalene fraction of step iib to step II;
iii. dealkylating said second dialkylnaphthalene fraction produced in step II and a fraction lean in dialkylnaphthalene of step iib;
IV. alkylating said fractions comprising naphthalene and comprising monoalkylnaphthalene of step I; and
v. recycling a product from step iii to step I.
27. A process for producing 2,6-dialkylnaphthalene from a feedstock, comprising the following steps:
I. separating said feedstock, in distillation towers, into a fraction comprising 2,6-dimethylnaphthalene, a fraction comprising 1,6-dimethylnaphthalene and a fraction comprising a remainder;
II. purifying 2,6-dialkylnaphthalene from said 2,6-dimethylnaphthlane 2,6-dimethylnaphthalene fraction of step I to produce 2,6-dialkylnaphthalene and a second dialkylnaphthalene fraction;
IIa. isomerizing said 1,6-dimethylnaphthalene fraction of step I;
iib. separating the isomerization product of step IIa into a fraction comprising 2,6-dimethylnaphthalene and a fraction comprising a remainder;
IIc. feeding said fraction comprising 2,6-dimethylnaphthalene of step iib to step II;
iii. dealkylating said fraction comprising a remainder of step I, said second dialkylnaphthalene fraction produced in step II, and a fraction comprising a remainder of step iib;
IV. separating a naphthalene and methylnaphthalene fraction from said dealkylation of step iii;
v. alkylating said naphthalene and methylnaphthalene fraction of step IV; and
VI. recycling a product from step v to step I.
23. A process for producing 2,6-dialkylnaphthalene from a feedstock, comprising the following steps:
I. separating said feedstock into a fraction comprising naphthalene and monoalkynaphthalene monoalkylnaphthalene, a fraction comprising dialkylnaphthalene and a fraction lean in dialkylnaphthalene;
II. separating and purifying 2,6-dialkylnaphthalene from said dialkylnaphthalene fraction of step I to produce 2,6-dialkylnaphthalene and a second dialkylnaphthalene fraction;
IIa. isomerizing said fraction lean in dialkylnaphthalene;
iib. separating the isomerization product of step IIa into a fraction comprising dialkylnaphthalene and a fraction lean in dialkylnaphthalene;
IIc. feeding said fraction comprising dialkylnaphthalene of step iib to step II;
iii. dialkylating said naphthalene and monoalkynaphthalene monoalkylnaphthalene fraction of step I, said second dialkylnaphthalene fraction produced in step II and a fraction lean in dialkylnaphthalene from step iib;
IV. separating a naphthalene and monoalkynaphthalene monoalkylnaphthalene fraction from said dialkylation of step iii;
v. alkylating said naphthalene and monoalkynaphthalene monoalkylnaphthalene fraction of step IV; and
VI. recycling a product from step v to step I.
20. A process of preparing a polyethylenenaphthalate polymer or polybutylenenaphthalate polymer comprising; :
A. oxidizing 2,6-dialkylnaphthalene to form 2,6-naphthalene-dicarboxylic acid; and
B. condensing said 2,6-naphthalene-dicarboxylic acid with a diol selected from the group consisting of ethylene glycol and butanediol to form a polyethylenenaphthalate polymer or polybutyrenenaphthalete polybutylenenaphthalate polymer
wherein said 2,6-dialkylnaphthalene is produced by a process comprising the following steps:
I. separating a feedstock into a naphthalene, monoalkynaphthalene monoalkylnaphthalene, and dialkylnaphthalene fractions: ;
II. separating and purifying 2,6-dialkylnaphthalene from said dialkylnaphthlane dialkylnaphthalene fraction of step I to produce 2,6-dialkylnaphthalene and a second dialkylnaphthalene fraction;
iii. alkylating said monoalkylnaphthalene fraction of step I with an alkylating agent to produce dialkylnaphthalene;
IV. transalkylating said naphthalene fraction of step I and said second dialkylnaphthalene fraction produced in step II, to produce monoalkylnaphthalene, and isomers of dialkylnaphthalene; wherein
said monoalkynaphthalene monoalkylnaphthalene fraction produced in step I is cracked before step iii, or in step iii, or after step iii.
21. A process for preparing a polyethylene naphthalate polymer or polybutyrenenaphthalate polybutylenenaphthalate polymer comprising;
A. oxidizing 2,6-dialkylnaphthalene to form 2,6-naphthalene-dicarboxylic acid; and
B. esterifying 2,6-naphthalene-dicarboxylic acid with methanol to form dimethyl-2,6-naphthalene-dicarboxylate; and
C. condensing said dimethyl-2,6-naphthalene-dicarboxylate with diol selected from the group consisting of ethylene glycol and butanediol to form a polyethylenenaphthalate polymer or polybutyrenenaphthalate polybutylenenaphthalate polymer
wherein said 2,6-dialkylnaphthalene is produced by a process comprising the following steps:
I. separating a feedstock into a naphthalene, monoalkynaphthalene monoalkylnaphthalene, and dialkylnaphthalene fractions: ;
II. separating and purifying 2,6-dialkylnaphthalene from said dialkylnaphthlane dialkylnaphthalene fraction of step I to produce 2,6-dialkylnaphthalene and a second dialkynaphthalene fraction;
iii. alkylating said monoalkylnaphthalene fraction of step I with an alkylating agent to produce dialkylnaphthalene;
IV. transalkylating said naphthalene fraction of step I and said second dialkylnaphthalene fraction produced in step II, to produce monoalkylnaphthalene, and isomers of dialkylnaphthalene; wherein
said monoalkynaphthalene monoalkylnaphthalene fraction produced in step I is cracked before step iii, or in step iii, or after step iii.
2. The process of
3. The process of
4. The process of
5. The process of
6. The process of
12.36±0.4
11.03±0.2
8.83±0.14
6.18±0.12
6.00±0.10
4.06±0.07
3.91±0.07
3.42±0.06.
7. The process of
8. The process of
9. The process of
10. The process of
11. The process of
12. The process of
12.36±0.4
11.03±0.2
8.83±0.14
6.18±0.12
6.00±0.10
4.06±0.07
3.91±0.07
3.42±0.06.
13. The process of
14. The process of claim 7 10, wherein at least a part of the other components containing alkylnaphthalene having a higher boiling point than naphthalenes in the separation after the isomerization are dealkylated, then recycled to step I.
15. The process of
16. The process of
17. The process of
18. The process of
0. 28. A process for preparing a polyester resin comprising:
producing 2,6-dialkylnaphthalene from a feedstock by the process of
oxidizing the 2,6-dialkylnaphthalene to form 2,6-naphthalenedicarboxylic acid; and
manufacturing the polyester resin from the 2,6-naphthalene-dicarboxylic acid.
0. 29. A process for preparing a polyester resin comprising:
producing 2,6-dialkylnaphthalene from a feedstock by the process of
oxidizing the 2,6-dialkylnaphthalene to form 2,6-naphthalenedicarboxylic acid;
esterifying the 2,6-naphthalenedicarboxylic acid with methanol to form a 2,6-naphthalenedicarboxylate; and
manufacturing the polyester resin from the 2,6-naphthalenedicarboxylate.
0. 30. A process for preparing a polyester resin comprising:
producing 2,6-dialkylnaphthalene from a feedstock by the process of
oxidizing the 2,6-dialkylnaphthalene to form 2,6-naphthalenedicarboxylic acid; and
manufacturing the polyester resin from the 2,6-naphthalene-dicarboxylic acid.
0. 31. A process for preparing a polyester resin comprising:
producing 2,6-dialkylnaphthalene from a feedstock by the process of
oxidizing the 2,6-dialkylnaphthalene to form 2,6-naphthalenedicarboxylic acid;
esterifying the 2,6-naphthalenedicarboxylic acid with methanol to form a 2,6-naphthalenedicarboxylate; and
manufacturing the polyester resin from the 2,6-naphthalenedicarboxylate.
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1. Field of the Invention
The present invention relates to a process for producing and obtaining 2,6-dialkylnaphthalene (DAN), in particular monoalkylnaphthylene monoalkylnaphthalene or naphthalene can be from about 20:1 to 1:20, preferably from 10:1 to 1:10. The reaction is suitably accomplished utilizing a feed space velocity of about 0.1 to 10.0 hr−1.
Preferred alkylating agents include alcohols, olefins, aldehydes, halides, and ethers. For example, methanol, dimethylether and polyalkylbenzene are preferred. Methanol and dimethylether are especially preferred.
A suitable catalyst for alkylation, is a synthetic zeolite characterized by an X-ray diffraction pattern including interplanar d-spacing and relative intensity I/Io×100
12.36 ± 0.4
M-VS
11.03 ± 0.2
M-S
8.83 ± 0.14
M-VS
6.18 ± 0.12
M-VS
6.00 ± 0.10
W-M
4.06 ± 0.07
W-S
3.91 ± 0.07
M-VS
3.42 ± 0.06 Å
VS.
A suitable catalyst is described in U.S. Pat. No. 5,001,295, as MCM-22.
The alkylation can be carried out in any of the known reactors usually employed for alkylation. For example, a tubular reactor with a downflow of reactants over a fixed bed of catalyst can be employed.
The conditions of transalkylation include a temperature of about 0 to 500° C., and preferably 200 to 450° C., and a pressure of 0 to 250 atmospheres and preferably 1 to 25 atmospheres. The mole ratio of naphthalene to DMN can be from about 10:1 to 10, preferably from 5:1 to 1:5. The reaction is suitably accomplished utilizing a feed space velocity of about 0.1 to 10.0 hr−1.
A suitable catalyst for transalkylation, is a synthetic zeolite characterized by an X-ray diffraction pattern including interplanar d-spacing and relative intensity I/Io×100
12.36 ± 0.4
M-VS
11.03 ± 0.2
M-S
8.83 ± 0.14
M-VS
6.18 ± 0.12
M-VS
6.00 ± 0.10
W-M
4.06 ± 0.07
W-S
3.91 ± 0.07
M-VS
3.42 ± 0.06 Å
VS.
A suitable catalyst is described in U.S. Pat. No. 5,001,295, as MCM-22.
Separation of 2,6-dialkylnaphthalene maybe conducted by conventional methods of separation known to those of ordinary skill in the art such as cooling crystallization or adsorption. For example separation may be affected by using a method of crystallization under high pressure. In general, a liquid mixture containing two or more substances is pressurized, and a certain substance in the mixture is solidified and separated from the residual liquid by the effect of the pressure. In other words, this method involves a separating and purifying technique wherein a liquid mixture containing two or more substances is placed in a tightly sealed pressure vessel, a portion of the desired substance, 2,6-dialkylnaphthalene, is solidified to form a solid-liquid co-existing state, the liquid is discharged from the co-existing system while maintaining the pressure of the solid-liquid co-existing system at a higher level than equilibrium pressure of the objective substance, then the solid remaining in the vessel is pressed for discharging the residual liquid between the solid particles and integrating the solid particles. This technique is generally described in U.S. Pat. No. 5,220,098.
The method involves injecting the slurry or liquid of the temperature of 70 to 120° C., preferably 80 to 100° C., into a high pressure vessel for conducting a crystallization under high pressure; adiabatically pressurizing the vessel to a pressure of from 300 to 4,000 kgf/cm2, preferably 500 to 2,000 kgf/cm2 to increase the quantity, i.e. the amount of 2,6-dialkylnaphthalene crystals, whereby coexistence of solid-liquid phases exist at the high pressure conditions; discharging the liquid phase component from the high pressure vessel, the discharging being conducted under pressure, to increase the ratio of the solid phase relative to the liquid phase within the vessel; lowering the pressure of the residual liquid phase so as to dissolve partially and purify the product; discharging the residual liquid phase by applying pressure to the solid phase within the high pressure vessel whereby a 2,6-dialkylnaphthalene crystal block having a high purity is obtained within with the high pressure vessel. By this technique, a purity of 2,6-dialkylnaphthalene (e.g. 2,6-dimethylnaphthylene 2,6-dimethylnaphthalene) of ≧98% by weight, preferably ≧99% by weight may be obtained.
In a preferred embodiment, a 2,6--lean dialkylnaphthalene fraction may be subject to isomerization conditions to provide for a dialkylnaphthalene fraction which has a greater content of 2,6-dialkylnaphthalene.
Isomerization conditions are those generally as disclosed in co-pending application U.S. Pat. No. 08/661,114, as suitable for conducting simultaneous transalkylation of dialkylnaphthalene and naphthalene, and isomerization of dialkylnaphthalenes, the relevant portions of which are hereby incorporated by reference.
As a suitable catalyst for isomerisation, a synthetic zeolite characterized by an X-ray diffraction pattern including interplanar d-spacing and relative intensity I/Io100
12.36 ± 0.4
M-VS
11.03 ± 0.2
M-S
8.83 ± 0.14
M-VS
6.18 ± 0.12
M-VS
6.00 ± 0.10
W-M
4.06 ± 0.07
W-S
3.91 ± 0.07
M-VS
3.42 ± 0.06 Å
VS.
A suitable catalyst is described in U.S. Pat. No. 5,001,295, as MCM-22, the entire contents of which are hereby incorporated by reference.
Preferably, isomerization is conducted at a weight hourly space velocity (WHSV) of dialkylnaphthalenes of 0.1 to 10, preferably 0.5 to 5 h−1, more preferably 0.75 to 1.5 h−1.
Preferably, isomerization is conducted at a temperature of from 100 to 500° C., preferably 150 to 350° C., more preferably 200 to 300° C.
Preferably, isomerization is conducted at a pressure of atmospheric to 100 kgf/cm2, preferably atmospheric to 30 kgf/cm2.
During isomerization it is possible to co-feed of hydrogen, but is not always necessary, in an amount of 0.1 to 10 mol-H2/mol-hydrocarbons.
The resulting 2,6-dialkylnaphthalene, e.g. 2,6-dimethylnaphthalene may then be used to produce a polyester resin, by oxidation of 2,6-dimethylnaphthalene to form 2,6-naphthalenedicarboxylic acid, by conventional methods known to those of ordinary skill in the art.
The 2,6-naphthalenedicarboxylic acid may then be condensed with a diol such as ethylene glycol, propylene glycol, butane diol, pentane diol and hexane diol. In a preferred embodiment, the polyester resin formed in a polyethylenenaphthalate or polybutylenenaphthalate resin. Such a condensation may be conducted by conventional methods known to those of ordinary skill in the art.
Alternatively a polyester resin may be formed from 2,6-naphthalenedicarboxylic acid by first esterification of 2,6-naphthalenedicarboxylic acid with an alcohol such as a C1-6 alcohol, such as methanol, ethanol, propanol, isopropanol, n-butanol, s-butanol, i-butanol, t-butanol. In a preferred embodiment, the alcohol is methanol. Esterification may be conducted by conventional techniques known to those of ordinary skill in the art. The alkylester of 2,6-naphthalenedicarboxylic acid by then be condensed with a diol as described above, by conventional methods known to those of ordinary skill in the art. Suitable diols include ethylene glycol, propylene glycol, butane diol, pentane diol and hexane diol. In a preferred embodiment the diol is either ethylene glycol or butane diol.
Having generally described this invention, a further understanding can be obtained by reference to certain specific examples which are provided herein for purposes of illustration only and are not intended to be limiting unless otherwise specified.
Example 1 Alkylation of MMN and Naphthalene:
A 153 g amount of MCM-22 is charged into a tubular reactor (volume:370 cc). As a feedstock for alkylation, 1-MMN, 2-MMN and naphthalene are used, and mixed at a molar ratio of 2.2 of 2-MMN/1-MMN, and a weight ratio of 3.0 of MMNs (1-MMN+2-MMN)/naphthalene.
Thereupon, the feedstock is supplied to the reactor (254° C., 5 kg/cm2) at a rate of 153.4 g/hr and 1.0 hr−1 in WHSV with a feed of hydrogen at the rate of 1.8 ft3/hr. Four hours later, methanol, as an alkylating agent, is introduced into the reactor at 35.5 g/hr, and alkylation is conducted for 20 hours. The product obtained is analyzed by gas chromatography, and the results are summarized in Table 1.
TABLE 1
Alkylation of Monomethylnaphthalene and Naphthalene
after
before reaction
reaction
Component (wt %)
dimethylnaphthalene
0
17.19
2,6-DMN
0
1.72
2,7-DMN
0
1.20
other isomers
0
14.27
monomethylnaphthalene
73.63
60.10
2-MMN
50.55
40.32
1-MMN
23.08
19.78
naphthalene
25.28
18.67
other component
1.00
3.91
evaluation
NL conversion (%)
—
26.15
2-MMN/1-MMN
2.2
2.04
MMN conversion (%)
—
18.37
2,6-DMN/total DMN (%)
—
10.02
2,6-DMN/2,7-DMN
—
1.44
As can be seen from Table 1, the ratio of 2,6-DMN/2,7-DMN is over 1.1 and the ratio of 2-MMN/1-MMN is over 2.0.
Example 2 Transalkylation:
A 30 g amount of MCM-22 ( 1/16″ D×⅜″L, cylindrical pellet) are charged into a tubular reactor (volume: 122 cc). The reactor is heated from room temperature to 400° C. at the rate of 100° C./hr while introducing nitrogen gas into the reactor at atmospheric pressure.
As a feedstock for transalkylation, isomers of DMN and naphthalene are mixed in a molar ratio of 5:1. Feedstock and product analysis are shown in Table 2.
TABLE 2
Transalkylation and Isomerization
before
after
reaction
reaction
Component (wt %)
dimethylnaphthalene
84.37
65.91
2,6-DMN
5.22
11.39
2,7-DMN
7.28
7.42
other isomers
71.87
47.10
monomethylnaphthalene
0.17
13.81
2-MMN
0.02
9.54
1-MMN
0.15
4.27
naphthalene
15.46
12.65
other component
0
7.63
evaluation
2,6-DMN/total DMN (%)
6.2{circle around (1)}
17.3{circle around (2)}
2,6-DMN/2,7-DMN
0.72
1.53
content of 2,6-DMN (after/before): @1
—
2.79
NL conversion (%)
—
18.2
DMN conversion (%)
—
21.9
produced MMN/(converted
—
0.41
DMN × 2): @2
2-MMN/1-MMN
—
2.2
@1 The ration of {circle around (2)}/{circle around (1)} in 2,6-DMN/total DMN
@2 Amounts are calculated on a molar basis.
As can be seen from Table 2, the ratio of 2,6-DMN/2,7-DMN is over 1.2 and the ratio of 2-MMN/1-MMN is over 2.0.
Example 3 Isomerization:
A 25 g amount of MCM-22 is charged into the tubular reactor (volume: 200 cc). The reactor is heated gradually from ambient temperature to 400° C. to dry the catalyst while supplying nitrogen gas, and the flow of nitrogen gas is ceased when the temperature becomes stable at 400° C. Thereupon, 2,6-lean-DMN is supplied to the reactor at the rate of 25 g/hr and 1.0 hr−1 in WHSV, and isomerization of DMN is carried out for four hours. The contents of the obtained product are analyzed by gas chromatography, and the results are summarized in Table 3.
TABLE 3
Isomerization
before
after
reaction
reaction
Component (wt %)
dimethylnaphthalene
98.09
80.10
2,6-DMN
6.21
13.96
2,7-DMN
8.48
8.66
other isomers
83.40
57.48
monomethylnaphthalene
0.20
9.77
2-MMN
0.03
6.71
1-MMN
0.17
3.06
naphthalene
0
0.78
other component
1.71
9.35
evaluation
2,6-DMN/total DMN (%)
6.3
17.4
2,6-DMN/2,7-DMN
0.73
1.61
As can be seen from Table 3, the ratio of 2,6-DMN/2,7-DMN is over 1.1.
Example 4 Separation of Purification:
(1) Crystallization under High Pressure Crystallization
A 1,505 g amount of DMN isomers is supplied into the high pressure crystallizer (KOBELCO 1.5 L type), and 236 g of 2,6-DNN crystals (purity 87%) are separated under the condition of 2,000 kgf/cm2 and 45° C.
(2) Cooling Crystallization
Using a vessel for crystallization (3 liter), 2,001 g of DMN isomers is cooled quickly from 50° C. to 40° C. with slow stirring. Then, 0.5 g of seed crystals are charged to the vessel which is kept at a temperature at 40° C. for an hour. Thereupon, the feedstock is cooled to 10° C. at 2° C./min. A 360 g amount of 2,6-DMN crystals (purity 68%) is separated by filtration under pressure.
The results of separation by both crystallization under high pressure and cooling crystallization are summarized in Table 4.
TABLE 4
Separation
before
Component (g)
crystallization
crystal
filtrate
CRYSTALLIZATION UNDER HIGH PRESSURE
2,6-DMN
301
205
96
2,7-DMN
232
22
210
other DMN
972
9
963
TOTAL
1505
236
1269
2,6-DMN/2,7-DMN
1.3
—
0.5
2,6-DMN/total DMN
20.0%
—
7.6%
purity of crystal
—
87%
—
recovery of 2,6-DMN
—
68%
—
yield of 2,6-DMN
—
13.6%
—
COOLING CRYSTALLIZATION
2,6-DMN
400
244
156
2,7-DMN
308
67
241
other DMN
1293
49
1244
TOTAL
2001
360
1641
2,6-DMN/2,7-DMN
1.3
—
0.65
2,6-DMN/total DMN
20.0%
—
9.5%
purity of crystal
—
68%
—
recovery of 2,6-DMN
—
61%
—
yield of 2,6-DMN
—
12.2%
—
“Recovery of 2,6-DMN” means the content of 2,6-DMN in the crystals against the content of 2,6-DMN in the feedstock.
“Yield of 2,6-DMN” means the content of 2,6-DMN in the crystal against the total weight of feedstock.
As shown in Table 4, the yield of 2,6-DMN by crystallization under high pressure is much higher than by cooling crystallization. Further, the 2,6-DMN/total-DMN ratio of the filtrate by crystallization under high pressure is less than 8%. Therefore, the filtrate is more effective as a feedstock for transalkylation and isomerization of 2,6-lean-DMN. Furthermore, when an attempt is made to increase the purity of crystals by cooling crystallization, the yield of 2,6-DMN decreases drastically.
Example 5 Cracking of Distillates from LCO
Example of Cracking
A 50 g amount of MCM-22 is charged into a tubular reactor. The reactor is heated gradually from ambient temperature to 325° C. to dry the catalyst while supplying hydrogen gas. Thereupon LCO distillate (Table 5) is supplied to the reactor at the rate of 50 g/hr and 1.0 hr−1 in WHSV, while supplying hydrogen gas at 10 l/hr. The reaction was conducted at 325, 355, 375, and 405° C. The results of cracking are summarized in Table 6 below. Initial boiling point data shows that cracking was conducted by contacting LCO feedstock with MCM-22.
Feed stock:
TABLE 5
wt. %
Naphthalene
4.02
2-Methylnaphthalene
12.56
1-Methylnaphthalene
6.00
2,6-DMN
0.58
2,7-DMN
0.54
1,3- + 1,7-DMN
0.8
1,6-DMN
0.34
2,3- + 1,4-DMN
0.12
1,5-DMN
0.07
1,2-DMN
0.06
1,8-DMN
0
Others
74.91
Cracking Conditions:
TABLE 6
Initial Boiling Point [° C.]
Reaction Temp. [° C.]
ASTM-D2887
Feed
167
325
129
355
104
375
61
405
29
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claim, the invention may be practiced otherwise than as specifically described herein.
Yamamoto, Koji, Motoyuki, Masahiro, McWilliams, John Paul, Sapre, Ajit Vishwanath, Donnelly, Susan Patricia
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