CN114130047A - Benzene-containing hydrogenated oil separation method - Google Patents
Benzene-containing hydrogenated oil separation method Download PDFInfo
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- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 title claims abstract description 357
- 238000000926 separation method Methods 0.000 title description 6
- 239000002904 solvent Substances 0.000 claims abstract description 72
- 238000004821 distillation Methods 0.000 claims abstract description 45
- 239000000047 product Substances 0.000 claims abstract description 30
- 238000000034 method Methods 0.000 claims abstract description 27
- 239000013067 intermediate product Substances 0.000 claims abstract description 23
- 125000003118 aryl group Chemical group 0.000 claims abstract description 22
- 238000002156 mixing Methods 0.000 claims abstract description 7
- 239000002994 raw material Substances 0.000 claims abstract description 6
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 claims description 144
- HXJUTPCZVOIRIF-UHFFFAOYSA-N sulfolane Chemical group O=S1(=O)CCCC1 HXJUTPCZVOIRIF-UHFFFAOYSA-N 0.000 claims description 25
- 238000010992 reflux Methods 0.000 claims description 16
- 238000005292 vacuum distillation Methods 0.000 claims description 16
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 claims description 10
- 239000008096 xylene Substances 0.000 claims description 10
- 238000000605 extraction Methods 0.000 abstract description 49
- 238000007670 refining Methods 0.000 abstract description 8
- 238000000354 decomposition reaction Methods 0.000 abstract description 4
- 239000003921 oil Substances 0.000 description 18
- 238000011084 recovery Methods 0.000 description 13
- 238000005984 hydrogenation reaction Methods 0.000 description 11
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 10
- 239000000203 mixture Substances 0.000 description 9
- 238000012545 processing Methods 0.000 description 8
- 235000010290 biphenyl Nutrition 0.000 description 5
- 239000004305 biphenyl Substances 0.000 description 5
- 125000006267 biphenyl group Chemical group 0.000 description 5
- ZUOUZKKEUPVFJK-UHFFFAOYSA-N phenylbenzene Natural products C1=CC=CC=C1C1=CC=CC=C1 ZUOUZKKEUPVFJK-UHFFFAOYSA-N 0.000 description 5
- 238000009835 boiling Methods 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 238000000895 extractive distillation Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 238000001514 detection method Methods 0.000 description 3
- 230000008929 regeneration Effects 0.000 description 3
- 238000011069 regeneration method Methods 0.000 description 3
- FYGHSUNMUKGBRK-UHFFFAOYSA-N 1,2,3-trimethylbenzene Chemical compound CC1=CC=CC(C)=C1C FYGHSUNMUKGBRK-UHFFFAOYSA-N 0.000 description 2
- IANQTJSKSUMEQM-UHFFFAOYSA-N 1-benzofuran Chemical compound C1=CC=C2OC=CC2=C1 IANQTJSKSUMEQM-UHFFFAOYSA-N 0.000 description 2
- QPUYECUOLPXSFR-UHFFFAOYSA-N 1-methylnaphthalene Chemical compound C1=CC=C2C(C)=CC=CC2=C1 QPUYECUOLPXSFR-UHFFFAOYSA-N 0.000 description 2
- YBYIRNPNPLQARY-UHFFFAOYSA-N 1H-indene Chemical compound C1=CC=C2CC=CC2=C1 YBYIRNPNPLQARY-UHFFFAOYSA-N 0.000 description 2
- UFWIBTONFRDIAS-UHFFFAOYSA-N Naphthalene Chemical compound C1=CC=CC2=CC=CC=C21 UFWIBTONFRDIAS-UHFFFAOYSA-N 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- UOHMMEJUHBCKEE-UHFFFAOYSA-N prehnitene Chemical compound CC1=CC=C(C)C(C)=C1C UOHMMEJUHBCKEE-UHFFFAOYSA-N 0.000 description 2
- 230000000087 stabilizing effect Effects 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000004587 chromatography analysis Methods 0.000 description 1
- 239000003034 coal gas Substances 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/14—Fractional distillation or use of a fractionation or rectification column
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/42—Regulation; Control
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- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention relates to the field of benzene refining, and discloses a method for separating hydrogenated oil containing benzene, which comprises the following steps: (1) carrying out first distillation on a benzene-containing raw material to obtain a benzene and non-aromatic intermediate product and a benzene-free product; (2) mixing the benzene and non-aromatic intermediate product with a solvent, and then carrying out second distillation to obtain a solvent for absorbing benzene; (3) subjecting the benzene-absorbed solvent to a third distillation to recover solvent; wherein the temperature of the third distillation is 155-160 ℃. In the invention, the operation temperature is greatly reduced, so that the decomposition speed of the solvent is greatly reduced, the quality of the solvent can be effectively ensured, the extraction efficiency of the solvent can be kept stable for a long time, and the product quality can be further improved.
Description
Technical Field
The invention relates to the field of benzene refining, in particular to a method for separating hydrogenated oil containing benzene.
Background
The existing benzene hydrogenation production system is divided into a hydrogenation process and a refining process, wherein the refining process is originally designed as a diphenyl extraction process, namely, a hydrogenation product is distilled by a prefractionator, a benzene/toluene two component obtained from the top of the prefractionator is pressurized to 0.4-06MPa by a pump, then enters an extraction tower from a 52 th disc tower plate of the extraction tower, a sulfolane extraction solvent is added into a 9 th disc tower plate of the top of the extraction tower for extraction and distillation, the solvent becomes a rich solvent after absorbing the benzene/toluene, and then enters a solvent recovery tower for vacuum distillation, a benzene/toluene mixture is obtained at the top of the recovery tower, the mixture enters a benzene/toluene tower for distillation, a benzene product is obtained at the top of the tower, and a toluene product is obtained at the bottom of the tower; the non-aromatic hydrocarbons in the benzene/toluene in the extraction tower cannot be absorbed by the solvent and are distilled out from the top of the extraction tower to form non-aromatic hydrocarbon products. At present, the design diameter of an extraction tower is 1.3m, so that the extraction capacity of the extraction tower is low, the hydrogenation process is not matched with the refining process, the capacity of a hydrogenation product produced in the hydrogenation process is high, the capacity of the extraction process for processing the hydrogenation product is small, in the normal continuous production process, the processing capacity of the extraction process is small, the processing amount of hydrogenated oil is low, and the annual processing amount of the hydrogenated oil does not reach the design capacity of 8 ten thousand tons. In addition, the operation temperature at the bottom of a solvent recovery tower is overhigh in the prior two-benzene extraction process adopted in the extraction process, the temperature at the bottom of the recovery tower often exceeds 180 ℃, the decomposition and polymerization speed of the extracting agent sulfolane is accelerated at high temperature, the deterioration speed of the solvent is accelerated, impurities in the solvent are increased, the extraction capacity and the effect are reduced, a lean solvent filter designed in a process system cannot fully filter the impurities in the lean solvent (sulfolane), the production and the operation of the extraction tower are unstable, the extraction capacity of the solvent is reduced, the processing capacity of a refining process is further reduced, the content of non-aromatic hydrocarbon in the pure benzene of the product is increased, the product quality is poor, and the consumption of the solvent (sulfolane) is increased.
Disclosure of Invention
The invention aims to solve the technical problems of low processing amount, high solvent decomposition speed, high solvent consumption, unstable operation of an extraction tower and poor product quality in the extraction process in the prior art, and provides a separation method of hydrogenated oil containing benzene.
The inventor of the invention finds in experiments that the benzene-containing hydrogenation product is directly distilled through a benzene/toluene tower without being rectified by a prefractionator, and a benzene and non-aromatic intermediate product (containing more than 99% of benzene and less than 160ppm (weight) of non-aromatic hydrocarbon) is obtained from the top of the tower, and the product at the bottom of the tower, such as a mixture of toluene, xylene and C8, is directly sold as a product, and the benzene and non-aromatic intermediate product is directly extracted and distilled.
In addition, the benzene and non-aromatic intermediate product does not contain toluene, the solvent only absorbs the benzene component to become rich solvent during extraction, and the actual operation temperature at the bottom of the solvent recovery tower can meet the requirement of vacuum distillation only by controlling the actual operation temperature at 155-160 ℃ during vacuum distillation because the boiling point of the benzene is 80.1 ℃ and is much lower than the boiling point (110 ℃) of the toluene. The present invention is further provided.
In order to achieve the above object, the present invention provides a method for separating hydrogenated oil containing benzene, comprising:
(1) carrying out first distillation on a benzene-containing raw material to obtain a benzene and non-aromatic intermediate product and a benzene-free product;
(2) mixing the benzene and non-aromatic intermediate product with a solvent, and then carrying out second distillation to obtain a solvent for absorbing benzene;
(3) subjecting the benzene-absorbed solvent to a third distillation to recover solvent;
wherein the temperature of the third distillation is 155-160 ℃.
The invention has the following beneficial effects:
(1) under the condition that the feeding amount of an extraction tower in the refining procedure is kept unchanged, the yield of a pure benzene product is improved to 250 tons/day from the original 200 tons/day, and the processing capacity of the hydrogenated oil is improved to 340 tons/day from the original 280 tons/day.
(2) The actual operation temperature of the bottom of the solvent recovery tower is controlled to be 155-160 ℃, the temperature of the solvent can be reduced by 20 ℃, the decomposition speed of the solvent is greatly reduced due to the great reduction of the operation temperature, the quality of the solvent can be effectively ensured, the extraction efficiency of the solvent can be kept stable for a long time, and the product quality can be further improved.
(3) The actual operation temperature of the solvent recovery tower is reduced by 20 ℃, so that the solvent is not decomposed, the quality of the solvent is kept stable, a solvent regeneration system can be stopped, the pollution of the residue discharged in the regeneration process to the environment is thoroughly eliminated, and the solvent consumption is reduced to 0.2 ton/month from the original 2 ton/month.
(4) The distillation process of the pre-fractionating tower is stopped, so that the load of the heat-conducting oil furnace is greatly reduced, and the coal gas consumption of the heat-conducting oil is reduced from 3000Nm3Reduction in/hTo 2600Nm3And h, the condenser of the product at the top of the pre-separation tower does not recycle circulating water any more, so that the temperature of the circulating water is reduced by 2-4 ℃ compared with the prior circulating water.
Drawings
FIG. 1 is a schematic flow diagram of a hydrogenated oil separation process according to examples 1 to 3 of the present invention.
Detailed Description
The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.
The invention provides a method for separating hydrogenated oil containing benzene, which comprises the following steps:
(1) carrying out first distillation on a benzene-containing raw material to obtain a benzene and non-aromatic intermediate product and a benzene-free product;
(2) mixing the benzene and non-aromatic intermediate product with a solvent, and then carrying out second distillation to obtain a solvent for absorbing benzene;
(3) subjecting the benzene-absorbed solvent to a third distillation to recover solvent;
wherein the temperature of the third distillation is 155-160 ℃.
Compared with the diphenyl extraction process in the prior art, the benzene-containing raw material (namely the hydrogenation product in the diphenyl process) does not need to be distilled through the prefractionator, so the prefractionator can be stopped, and the energy consumption of the refining process (including the consumption of heat conducting oil at the bottom of the prefractionator and the consumption of circulating water of a condenser of a product at the top of the prefractionator) can be greatly reduced. In addition, the actual operation temperature of the solvent recovery tower is reduced by 20 ℃, so that the solvent is not decomposed, the quality of the solvent is kept stable, and the solvent consumption and the pollution of residues discharged in the solvent regeneration process to the environment can be greatly reduced.
In some embodiments of the present invention, the benzene-containing feedstock comprises: benzene, toluene, xylene and heavy benzene. In the present invention, heavy benzene means a mixture of components having a boiling point higher than that of xylene in the benzene-containing raw material, such as trimethylbenzene, tetramethylbenzene, naphthalene, methylnaphthalene, indene, and 2, 3-benzofuran.
In some embodiments of the present invention, the composition of the benzene-containing feedstock is not particularly limited, and preferably, the present invention is particularly suitable for processing benzene-containing feedstocks having a benzene content of 67 to 70 wt.% and a toluene content of 12 to 14 wt.%, based on the total amount of the benzene-containing feedstock.
In some embodiments of the present invention, the present invention does not specifically limit the temperature of the benzene-containing feedstock, but to produce high purity benzene, the temperature of the benzene-containing feedstock is cooled to 105-110 ℃ prior to the first distillation.
In some embodiments of the present invention, to improve process capacity and yield high quality pure benzene of high purity, the feed weight ratio of benzene and non-aromatic intermediate products to solvent is preferably from 6 to 7: 1.
in some embodiments of the invention, the solvent is sulfolane.
In some embodiments of the present invention, the first distillation is performed in a first distillation column (also may be called a benzene/toluene column) to increase the capacity of the distillation system, and the operating conditions of the first distillation column include: the temperature at the top of the tower is 86-97 ℃, the pressure at the top of the tower is 50-55kPa, the temperature of the sensitive plate is 102-120 ℃, the temperature at the bottom of the tower is 150-160 ℃, the pressure at the bottom of the tower is 145-155kPa, the number of tower plates is 70-80, and the reflux ratio is 1-1.5.
In some embodiments of the invention, the second distillation is an extractive distillation, the second distillation being carried out in a second distillation column (which may also be called an extraction column) operating conditions comprising: the temperature of the top of the warm tower is 65-75 ℃, the pressure of the top of the warm tower is 50-55kPa, the temperature of the sensitive plate is 130-133 ℃, the temperature of the bottom of the warm tower is 150-160 ℃, the pressure of the bottom of the warm tower is 145-165kPa, the number of the tower plates is 70-80, and the reflux ratio is 1-2.
In the present invention, the third distillation is not limited as long as the purpose of separating benzene from the solvent can be achieved, and it is preferable that the third distillation is vacuum distillation.
In some embodiments of the invention, the third distillation is performed in a vacuum distillation column (also called a recovery column) operating conditions comprising: the temperature at the top of the tower is 50-65 ℃, the pressure is-40 to-55 kPa, the temperature of the sensitive plate is 65-75 ℃, and the temperature at the bottom of the tower is 155-; the tower bottom pressure is-10 to 10kPa, the number of tower plates is 30 to 35, and the reflux ratio is 0.5 to 0.8.
The present invention will be described in detail below by way of examples. The hydrogenated oils used in the examples and comparative examples were derived from the product obtained after hydrogenation of benzene, and had a benzene content of 68 wt% and a toluene content of 13 wt%, based on the total amount of the hydrogenated oil.
Example 1
(1) Referring to fig. 1, firstly, the hydrogenated oil is cooled to 105 ℃, and enters a benzene/toluene tower for further distillation (the temperature of the top of the benzene/toluene tower is 97 ℃, the temperature of a sensitive plate of the benzene/toluene tower is 120 ℃, the temperature of the bottom of the benzene/toluene tower is 160 ℃, the top pressure of the benzene/toluene tower is 55kPa, the pressure of the bottom of the benzene/toluene tower is 155kPa, the number of plates of the benzene/toluene tower is 70, the reflux ratio is 1.5, an intermediate product of benzene and non-aromatic hydrocarbon is obtained from the top of the tower, and a mixture of toluene, xylene and C8 at the bottom of the tower directly enters a toluene or xylene tank to be sold as a product;
(2) mixing the benzene and non-aromatic intermediate product with sulfolane according to a weight ratio of 6, and then carrying out extractive distillation (the temperature of an extraction tower top is 75 ℃, the pressure of the tower top is 55kPa, the temperature of a sensitive plate is 133 ℃, the temperature of a tower bottom is 160 ℃, the pressure of the tower bottom is 155kPa, the number of tower plates is 70, the reflux ratio is 1, obtaining a non-aromatic product from the extraction tower top, and obtaining a sulfolane rich solvent for absorbing benzene at the tower bottom;
(3) the sulfolane rich solvent which absorbed benzene was subjected to vacuum distillation (column top temperature 65 ℃, pressure-55 kPa, sensitive plate temperature 65 ℃, column bottom temperature 160 ℃, column bottom pressure 10kPa, number of plates 35, reflux ratio 0.8) to recover the sulfolane solvent.
And (3) detecting the benzene content in the benzene and non-aromatic intermediate product obtained in the step (1) and the purity of the sulfolane recovered after vacuum distillation in the step (3), wherein the detection results are shown in table 1.
Example 2
(1) Referring to fig. 1, firstly, the hydrogenated oil is cooled to 112 ℃, and enters a benzene/toluene tower for further distillation (the temperature of the top of the benzene/toluene tower is 94 ℃, the temperature of a sensitive plate of the benzene/toluene tower is 102 ℃, the temperature of the bottom of the benzene/toluene tower is 150 ℃, the top pressure of the benzene/toluene tower is 50kPa, the pressure of the bottom of the benzene/toluene tower is 150kPa, the number of plates of the benzene/toluene tower is 80, the reflux ratio is 1, an intermediate product of benzene and non-aromatic hydrocarbon is obtained from the top of the tower, and a mixture of toluene, xylene and C8 at the bottom of the tower directly enters a toluene or xylene tank to be sold as a product;
(2) mixing the benzene and non-aromatic intermediate product with sulfolane according to a weight ratio of 7, and then carrying out extractive distillation (the temperature of an extraction tower top is 65 ℃, the pressure of the tower top is 50kPa, the temperature of a sensitive plate is 130 ℃, the temperature of a tower bottom is 150 ℃, the pressure of the tower bottom is 145kPa, the number of tower plates is 80, the reflux ratio is 2, obtaining a non-aromatic product from the extraction tower top, and obtaining a sulfolane rich solvent for absorbing benzene at the tower bottom;
(3) and (3) carrying out vacuum distillation on the sulfolane rich solvent absorbing the benzene (the temperature at the top of the tower is 50 ℃, the pressure is-40 kPa, the temperature of a sensitive plate is 65 ℃, the temperature at the bottom of the tower is 155 ℃, the pressure at the bottom of the tower is-10 kPa, the reflux ratio is 0.78), obtaining a pure benzene product at the top of the tower, and recovering the sulfolane solvent at the bottom of the tower.
And (3) detecting the benzene content in the benzene and non-aromatic intermediate product obtained in the step (1) and the purity of the sulfolane recovered after vacuum distillation in the step (3), wherein the detection results are shown in table 1.
Example 3
(1) Referring to fig. 1, firstly, the hydrogenated oil is cooled to 108 ℃, and enters a benzene/toluene tower for further distillation (the temperature of the top of the benzene/toluene tower is 95 ℃, the temperature of a sensitive plate of the benzene/toluene tower is 115 ℃, the temperature of the bottom of the benzene/toluene tower is 155 ℃, the top pressure of the benzene/toluene tower is 52kPa, the pressure of the bottom of the benzene/toluene tower is 150kPa, the number of plates of the benzene/toluene tower is 75, the reflux ratio is 1.3), benzene and non-aromatic hydrocarbon intermediate products are obtained from the top of the tower, and a mixture of toluene, xylene and C8 at the bottom of the tower directly enters a toluene or xylene tank to be sold as a product;
(2) mixing the benzene and non-aromatic intermediate product with sulfolane according to a weight ratio of 6.5, and then carrying out extractive distillation (the temperature of an extraction tower top is 70 ℃, the temperature of a sensitive plate of the extraction tower is 131 ℃, the temperature of an extraction tower bottom is 155 ℃, the pressure of the extraction tower top is 53kPa, the pressure of the tower bottom is 155kPa, the number of tower plates of the extraction tower is 75, and the reflux ratio is 1.3) to obtain a sulfolane rich solvent for absorbing benzene;
(3) the sulfolane rich solvent absorbing benzene was subjected to vacuum distillation (the temperature at the top of the recovery column was 60 ℃, the temperature of the sensitive plate was 70 ℃, the temperature at the bottom of the column was 158 ℃, the pressure at the top of the column was-50 kPa, the pressure at the bottom of the column was 5kPa, the number of trays was 35, and the reflux ratio was 0.7) to recover sulfolane.
And (3) detecting the benzene content in the benzene and non-aromatic intermediate product obtained in the step (1) and the purity of the sulfolane recovered after vacuum distillation in the step (3), wherein the detection results are shown in table 1.
Comparative example 1
The separation of hydrogenated oil was carried out in the same manner as in example 1, except that, in the step (3), the bottom temperature of the vacuum distillation was 175 ℃.
Comparative example 2
The technological process of the diphenyl extraction comprises the following steps; the hydrogenation product obtained from the bottom of the stabilizing tower after the reduced pressure distillation in the stabilizing tower is subjected to pre-fractionating tower distillation, the benzene/toluene two components (the benzene content is 82.5 wt%, the toluene content is 16.2 wt% and the non-aromatic hydrocarbon content is 1.3 wt%) obtained from the top of the pre-fractionating tower are pressurized to 0.4-06MPa by a pump, then the benzene/toluene two components enter an extraction tower from a 46 th tray plate of the extraction tower, a sulfolane extraction solvent is added into a 9 th tray plate of the top of the extraction tower for extraction distillation (the temperature of the top of the extraction tower is 75 ℃, the temperature of a sensitive plate of the extraction tower is 133 ℃, the temperature of the bottom of the extraction tower is 160 ℃, the pressure of the top of the extraction tower is 55kPa, the pressure of a bottom of the extraction tower is 165kPa, the number of 70 trays of the extraction tower is 2, the solvent absorbs benzene and toluene to form a rich solvent, the rich solvent enters a solvent recovery tower for vacuum distillation (the temperature of the top of 75 ℃, the temperature of the sensitive plate is 78 ℃, the temperature of the bottom of the tower is 178 ℃, the pressure of the top of the tower is-55 kPa, the bottom pressure was 10kPa, the number of trays was 34, and the reflux ratio was 0.8)), a benzene/toluene mixture was obtained at the top of the recovery column, and sulfolane was recovered at the bottom.
Test example
The benzene content in the benzene and non-aromatic intermediate products obtained in the examples and the comparative examples of the present invention and the purity of the sulfolane recovered after vacuum distillation were measured in a gas chromatograph with an equipment model of agilent 7820 gas chromatograph under the following test conditions: chromatography column SE-30X 30m X0.32 mm X0.33 μm; a sample inlet is 300 ℃; the split ratio is 10: 1; column pressure 128.9 kPa; the total flow rate is 64.3 mL/min; a detector is 300 ℃; the column temperature is 40 ℃ for 2min,20 ℃/min and 260 ℃ for 15 min. The results are shown in Table 1.
TABLE 1
The results in table 1 show that, in the benzene extraction process of the present invention, only low boiling point substances such as benzene and non-aromatic hydrocarbons are absorbed in the solvent, and after vacuum recovery, benzene and non-aromatic hydrocarbons can be completely separated from the solvent, and the sulfolane content in the recovered solvent is 2.2% higher than that in the diphenyl extraction, so the effect of the present invention is significantly better.
The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.
Claims (10)
1. A method for separating hydrogenated oil containing benzene is characterized by comprising the following steps:
(1) carrying out first distillation on a benzene-containing raw material to obtain a benzene and non-aromatic intermediate product and a benzene-free product;
(2) mixing the benzene and non-aromatic intermediate product with a solvent, and then carrying out second distillation to obtain a solvent for absorbing benzene;
(3) subjecting the benzene-absorbed solvent to a third distillation to recover solvent;
wherein the temperature of the third distillation is 155-160 ℃.
2. The process of claim 1, wherein the benzene-containing feedstock comprises: benzene, toluene, xylene and heavy benzene.
3. The process of claim 2, wherein the benzene content is 67-70 wt.% and the toluene content is 12-14 wt.% based on the total amount of the benzene-containing feedstock.
4. The process as claimed in any one of claims 1 to 3, wherein the temperature of the benzene-containing feedstock is cooled to 105-110 ℃ prior to the first distillation.
5. The process of any one of claims 1-4, wherein the benzene and non-aromatic intermediate product to solvent feed weight ratio is from 6 to 7: 1.
6. the process of any one of claims 1-5, wherein the solvent is sulfolane.
7. The process of any of claims 1-6, wherein the first distillation is carried out in a first distillation column, the operating conditions of the first distillation column comprising: the temperature of the top of the warm tower is 86-97 ℃, the pressure of the top of the warm tower is 50-55kPa, the temperature of the sensitive plate is 102-120 ℃, the temperature of the bottom of the warm tower is 150-160 ℃, the pressure of the bottom of the warm tower is 145-155kPa, the number of the tower plates is 70-80, and the reflux ratio is 1-1.5.
8. The process of any of claims 1-7, wherein the second distillation is carried out in a second distillation column, the operating conditions of the second distillation column comprising: the temperature of the top of the warm tower is 65-75 ℃, the pressure of the top of the warm tower is 50-55kPa, the temperature of the sensitive plate is 130-133 ℃, the temperature of the bottom of the warm tower is 150-160 ℃, the pressure of the bottom of the warm tower is 145-165kPa, the number of the tower plates is 70-80, and the reflux ratio is 1-2.
9. The process according to any one of claims 1-8, wherein the third distillation is a vacuum distillation.
10. The process according to any one of claims 1 to 9, wherein the third distillation is carried out in a vacuum distillation column, the operating conditions of which comprise: the temperature at the top of the tower is 50-65 ℃, the pressure is-40 to-55 kPa, the temperature of the sensitive plate is 65-75 ℃, and the temperature at the bottom of the tower is 155-; the tower bottom pressure is-10 to 10kPa, the number of tower plates is 30 to 35, and the reflux ratio is 0.5 to 0.8.
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| CN202111212086.0A CN114130047A (en) | 2021-10-18 | 2021-10-18 | Benzene-containing hydrogenated oil separation method |
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|---|---|---|---|---|
| CN103520945A (en) * | 2012-07-04 | 2014-01-22 | 天津大学 | Device and method for refining crude benzene hydrogenation product |
| CN109053356A (en) * | 2018-08-06 | 2018-12-21 | 宁夏宝丰能源集团股份有限公司 | A kind of extraction separating method and crude benzol processing technology of triphenyl fraction |
| CN111943796A (en) * | 2020-09-04 | 2020-11-17 | 中冶焦耐(大连)工程技术有限公司 | Process and system for hydrogenation and extractive distillation of crude benzene |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103520945A (en) * | 2012-07-04 | 2014-01-22 | 天津大学 | Device and method for refining crude benzene hydrogenation product |
| CN109053356A (en) * | 2018-08-06 | 2018-12-21 | 宁夏宝丰能源集团股份有限公司 | A kind of extraction separating method and crude benzol processing technology of triphenyl fraction |
| CN111943796A (en) * | 2020-09-04 | 2020-11-17 | 中冶焦耐(大连)工程技术有限公司 | Process and system for hydrogenation and extractive distillation of crude benzene |
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