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CN1059851A - Solvent recovery methods in hydrocarbon processing - Google Patents

Solvent recovery methods in hydrocarbon processing Download PDF

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Publication number
CN1059851A
CN1059851A CN91110451A CN91110451A CN1059851A CN 1059851 A CN1059851 A CN 1059851A CN 91110451 A CN91110451 A CN 91110451A CN 91110451 A CN91110451 A CN 91110451A CN 1059851 A CN1059851 A CN 1059851A
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tower
solvent
evaporation
heat
pressure
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CN91110451A
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CN1020745C (en
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徐亦方
马福祥
李忠泽
吕魏洪
万昌源
钱晓峰
孙康
胡秀敏
吕翠英
李晓鸥
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Petroleum University
China Petrochemical Corp
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Petroleum University
China Petrochemical Corp
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    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00Climate change mitigation technologies in the production process for final industrial or consumer products
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  • Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)

Abstract

本发明提供一种烃类加工过程中的溶剂回收方 法,是对换热网络理论进行研究后得出来的。在多效 蒸发可变冷、热流系统中,当达到多窄点时,回收的热 量最多,而且传热面积在经济上也是合理的。在工业 装置32万吨/年的润滑油糠醛精制装置采用本发 明后,与双塔回收糠醛方法相比,可节约20~35%的 能耗,折合118万元/年。对于现有的三塔回收技 术改造,可节约10~20%的能耗和10~30%的传热 面积。The invention provides a solvent recovery method in the process of hydrocarbon processing The method is obtained after studying the heat exchange network theory. in pleiotropic In the evaporative variable cooling and heat flow system, when the multi-narrow point is reached, the recovered heat The amount is the largest, and the heat transfer area is also economically reasonable. in industry The 320,000 tons/year lubricating oil furfural refining unit adopts this invention After the invention, compared with the double-tower furfural recovery method, it can save 20-35% Energy consumption, equivalent to 1.18 million yuan/year. For the existing three-tower recovery technology Technical transformation can save 10-20% energy consumption and 10-30% heat transfer area.

Description

Method for recovering solvents in the hydro carbons process
The invention relates to the method for recovering solvents in the solvent processing petroleum hydrocarbon process, relate to the solvent refined oil process, the improvement of method for recovering solvents in the solvent dewaxing process.
Handling lubricating oil with solvent is a kind of petroleum refining process, and this process generates the mixed liquor that contains solvent and oil after solvent is handled lubricating oil, need from then on to reclaim solvent in the mixture.Solvent recovery adopts the multitower recovery system, also claims multi-effect evaporation system, and each pressure tower difference can fully recover energy energy efficient.
In prior art, as US4,214,975 and US4,422,923.This technology reclaims each evaporating column pressure of solvent and is followed successively by low pressure, high and medium voltage.
Another technology is US4,390,418, and US4,419,227 and EP98,359.Each evaporating column pressure that this technology reclaims solvent raises successively.
More than all do not adopt in 5 technology medium pressure column top steam be used to heat medium pressure column self charging, also not to the first evaporating column charging in appropriate position shunting and different hot-fluid heat exchange, promptly do not have appropriate parallel heat exchanging.
Another technology is J58-122,002, and this technology adopts the heat exchange process of three tower parallel connections, is about to the first tower charging and is divided into three strands, respectively with the hot-fluid heat exchange, and enters the evaporating column of three same pressure respectively.This technology does not consider with the first single evaporating column do not have to consider at appropriate position parallel heat exchanging yet.Medium pressure column equally also of no use top solvent vapo(u)r heating self charging.
Another technology is US4,830,711, and this technology is considered to improve the recovery heat with compressor.Its pressure sequence adopts first high pressure and back low pressure.This technology is inapplicable for the solvent of easy condensation or easy coking.
The objective of the invention is to overcome the shortcoming of prior art, propose a kind of according to the variable hot and cold stream principle of multiple-effect evaporation, improve the heat exchange process of solvent recovery multitower system and the method for operating condition, to reduce heating furnace fuel oil consumption and to make the heat exchanger heat transfer area the most reasonable.
Draw after the theory of heat exchanging network of the present invention is studied, in the variable hot and cold streaming system of multiple-effect evaporation, when reaching how narrow some when (also claiming narrow point, folder point, pinch point), the heat of recovery is maximum, and heat transfer area also is rational economically.Under the situation of how narrow point, have only the parallel heat exchanging of employing just can overcome the difficulty that heat-exchange network has a narrow range of temperature, also show that solvent vapo(u)r heating medium pressure column self charging of pushing up with medium pressure column can obtain good effect simultaneously.Therefore, the present invention heats second evaporating column self charging with the solvent vapo(u)r of second evaporating column (being medium pressure column) cat head.And adopt the first evaporating column charging heat exchange to be in proper order simultaneously: divide equally earlier be three stocks not with first, second and the 3rd condensate liquid parallel heat exchanging that evaporates the recovered overhead solvent; Again with the first evaporation cat head steam heat-exchanging; Dividing equally is two strands again, with the condensate liquid parallel heat exchanging of the second and the 3rd evaporating column recovery solvent; Again with the steam heat-exchanging of the second evaporating column recovered solvent partial condensation.This flow process be not experience and arbitrarily, be to carry out in strict accordance with the theory that the inventor proposes.For three towers evaporations at the ratio of the 3rd evaporating column charging and this tower evaporation capacity greater than 60 to 80%, it is uneconomic adopting the 3rd evaporation cat head Steam Heating the 3rd evaporating column self charging.For reclaiming dissolving agent process more than three towers, which tower will adopt the charging of evaporation cat head Steam Heating self, how much decide according to this tower charging oil content.
Therefore, feature of the present invention is to adopt three evaporating columns to reclaim solvent at least, the pressure of three towers is low pressure in turn, medium and high pressure, adopt second evaporating column (medium pressure column) top solvent vapo(u)r to heat second evaporating column self charging in the present invention, and in the first evaporating column feeding preheating process, earlier solvent-laden material being divided equally is other and first evaporating columns of three stocks, second evaporating column and the 3rd evaporation cat head recovered solvent condensate liquid parallel heat exchanging, again with the first evaporation cat head solvent vapo(u)r heat exchange, divide equally is that two stocks are not with second again, the 3rd evaporating column reclaims the condensate liquid parallel heat exchanging of solvent, evaporates the steam heat-exchanging of solvent overhead partial condensation with second again.
Accompanying drawing 1 is a method for recovering solvents flow chart of the present invention, among the figure:
1-solvent and oil mixture
The 32 cold flow chargings of 2-heat exchanger
The 33 cold flow chargings of 3-heat exchanger
The 34 cold flow chargings of 4-heat exchanger
The 32 cold flow dischargings of 5-heat exchanger
The 33 cold flow dischargings of 6-heat exchanger
The 34 cold flow dischargings of 7-heat exchanger
8-heat exchanger 32,33,34 discharging concetrated pipes
The 35 cold flow dischargings of 9-heat exchanger
The 36 cold flow chargings of 10-heat exchanger
The 37 cold flow chargings of 11-heat exchanger
The 36 cold flow dischargings of 12-heat exchanger
The 37 cold flow dischargings of 13-heat exchanger
14-heat exchanger 36,37 discharging concetrated pipes
The 38 cold flow dischargings of 15-condenser
The 39 cold flow chargings of 16-condenser
17-first evaporating column 43 overhead vapours
The 35 hot-fluid dischargings of 18-condenser
The 34 hot-fluid discharging throttlings of 19-heat exchanger are cut down
The 39 cold flow dischargings of 20-condenser
The 40 cold flow dischargings of 21-condenser
22-second evaporating column 44 overhead vapours
The 39 hot-fluid dischargings of 23-condenser
The 38 hot-fluid dischargings of 24-condenser
The 36 hot-fluid dischargings of 25-heat exchanger
The 41 cold flow chargings of 26-heating furnace
The 41 cold flow dischargings of 27-heating furnace
28-the 3rd evaporating column 45 overhead vapours
The 40 hot-fluid dischargings of 29-condenser
The 37 hot-fluid dischargings of 30-heat exchanger
The 32 hot-fluid discharging throttlings of 31-heat exchanger are cut down
32,33, the 34-heat exchanger
The 35-condenser
36, the 37-heat exchanger
38,39, the 40-condenser
The 41-heating furnace
45 dischargings of 42-the 3rd evaporating column
43-first evaporating column
44-second evaporating column
45-the 3rd evaporating column
46-condenser 38 cross-lines
47-condenser 39 cross-lines
48-heat exchanger 33 hot-fluid outlet throttlings cut down
The solvent recovery flow chart that is used for containing furfural and extraction oil below in conjunction with accompanying drawing 1 concrete explanation the present invention. It is three strand 2,3,4 that solvent and extraction oil mixing rear (solvent accounts for 90~95% matter) are divided equally by 1, enters respectively heat exchanger 32,33 and 34. The outlet be respectively 5,6,7, merge into one 8, enter condenser 35, outlet is 9, dividing equally is two strand 10,11. Enter respectively heat exchanger 36,37, outlet is 12,13, merges into 14, enters condenser 38, and outlet is 15, and cross-line 43 is arranged herein, is used for the control temperature, enters first evaporating column 43. First evaporating column, 43 pressure are 0.1 to 0.18MPa(absolute pressure), 165~180 ℃ of temperature. First evaporating column, 43 bottoms are for containing solvent liquid, enter condenser 39 through 16, and outlet is 20, and cross-line 44 is arranged herein, is used for the control temperature. Enter condenser 40, outlet is 21, enters second evaporating column 44. The second evaporating column pressure is 0.15 to 0.21MPa(absolute pressure), 175~190 ℃ of temperature.
Second evaporating column, 44 bottoms are for containing solvent liquid, enter heating furnace 41 through 26, and outlet is 27, enters the 3rd evaporating column 45. The pressure of the 3rd evaporating column 45 is 0.2 to 0.25MPa(absolute pressure), 195~220 ℃ of temperature. The 3rd evaporating column 45 bottoms are for containing solvent 10~35%(matter) liquid.
The first evaporation solvent overhead steam enters condenser 35 by 17, all is condensed into liquid, and outlet is 18, enters heat exchanger 34, and outlet is 19. The temperature of heat exchanger 34 drops to 155~160 ℃ from 165~175 ℃.
Second evaporating column 44, solvent overhead steam enter condenser 39 from 22, after the partial condensation, enter condenser 38 by 23, all be condensed into liquid, outlet is 24, enters heat exchanger 36, and outlet is 25, enter heat exchanger 33, outlet is 48, and the pressure of the gate control cut down the 3rd evaporating column 44 is arranged.The temperature of heat exchanger 36 is reduced to 165~175 ℃ from 175~190 ℃, and the temperature of heat exchanger 33 is reduced to 155~160 ℃ from 165~175 ℃.
The 3rd evaporating column 45, solvent overhead steam enter condenser 40 from 28, all are condensed into liquid, and outlet is 29, enters heat exchanger 37, and outlet is 30, enters heat exchanger 32, and outlet is 31, and the pressure of the gate control cut down the 3rd evaporating column 45 is arranged.The temperature of heat exchanger 37 is reduced to 165~175 ℃ from 175~190 ℃, and the temperature of heat exchanger 32 is reduced to 155~160 ℃ from 165~175 ℃.
The above solvent recovering system that proposes is also applicable to furfural, the recovery of other solvents such as N-methyl pyrrolidone.Or the butanone-toluene in the solvent dewaxing process, butanone-toluol-benzene, first isobutyl ketone-toluene, the solvent recovery of first isobutyl ketone-toluol-benzene.
To the lube oil furfural refining of 320,000 tons/year of commercial plants, behind employing the present invention, reclaim furfural with double tower and compare, can save 20 to 35% energy consumption, amount to 1,180,000 yuan/year.For three towers evaporations prior art, adopt the present invention after, can save 10 to 30% heat transfer area and 10 to 20% energy consumption.
Further demonstrate characteristics of the present invention below.
Embodiment 1
What produce during matter lubricating oil in processing contains furfural 93.64%(matter) 99.1 tons of Extracts/time, heat exchange to 168 ℃ is evaporated in first evaporating column, pressure is the 0.155MPa(absolute pressure); Heat exchange to 188 ℃ is again evaporated in second evaporating column, and pressure is the 0.187MPa(absolute pressure); Be heated to 214 ℃ at last, evaporate in the 3rd evaporating column, pressure is the 0.218MPa(absolute pressure).Extract oil out at the bottom of the last tower and contain furfural 25%(matter).Imitate evaporation energy-conservation 20% than two.
Embodiment 2
What produce when handling heavy grease contains furfural 93.89%(matter) 151.5 tons of Extracts/time, heat exchange to 179 ℃ is evaporated in first evaporating column, pressure is the 0.175MPa(absolute pressure); Heat exchange to 190 ℃ is again evaporated in second evaporating column, and pressure is the 0.207MPa(absolute pressure); Be heated to 217 ℃ at last, evaporate in the 3rd evaporating column, pressure is the 0.244(absolute pressure).Extract oil out at the bottom of the last tower and contain alditol 24.9%(matter).Imitate evaporation energy-conservation 30% than two.

Claims (2)

1、一种关于烃类加工过程中的溶剂回收方法,其特征是至少采用三个蒸发塔回收溶剂,三个塔的压力顺次为低压,中压和高压,在本发明中采用第二蒸发塔(中压塔)顶溶剂蒸汽加热第二蒸发塔自身进料,并在第一蒸发塔进料预热过程中,先将含溶剂的物料平分为三股分别与第一蒸发塔、第二蒸发塔和第三蒸发塔顶回收的溶剂冷凝液并联换热,再与第一蒸发塔顶溶剂蒸汽换热,再平分为两股,分别与第二、第三蒸发塔回收溶剂的冷凝液并联换热,再与第二蒸发塔顶溶剂部分冷凝的蒸汽换热,具体说,对三塔蒸发回收糠醛进料预热过程中,先将进料平等分为三股,与第一、第二和第三蒸发塔顶溶剂冷凝液换热,使温度自165至175℃冷却到155至160℃,接着与第一蒸发塔顶溶剂蒸汽换热,再将物料分为二股分别与第二、第三蒸发塔回收溶剂的冷凝液换热,使温度自175至190℃降为165至175℃,在第二蒸发塔进料预热过程中,用第二蒸发塔顶溶剂蒸汽部分冷凝加热第二蒸发塔自身进料,再用第三蒸发塔顶蒸汽充分冷凝至175至190℃进行加热,所述的第一和第二蒸发塔进料的预热必须同时实施,才能得到最大节能和减少传热面积,所述的第一蒸发塔压力为0.1至0.18MPa绝压,温度165至180℃,塔顶溶剂蒸汽依次经过两次换热,第一次是冷凝器,第二次为换热器,所述的第二蒸发塔压力为0.15至0.21MPa绝压,温度175至190℃,塔顶溶剂蒸汽依次经过四次换热,第一、二次是冷凝器,第三、四次是换热器,所述的第三蒸发塔压力为0.2至0.25MPa绝压,温度195至220℃,塔顶溶剂蒸汽依次经过三次换热,第一次是冷凝器,第二、三次是换热器。1, a kind of solvent recovery method in the processing process of hydrocarbons, it is characterized in that adopting three evaporation towers to reclaim solvent at least, the pressure of three towers is low pressure successively, middle pressure and high pressure, adopts the second evaporation tower in the present invention The solvent vapor at the top of the tower (medium pressure tower) heats the feed of the second evaporation tower itself, and during the preheating process of the feed of the first evaporation tower, the solvent-containing material is first divided into three shares and respectively shared with the first evaporation tower and the second evaporation tower. The solvent condensate recovered from the top of the evaporation tower and the third evaporation tower is connected in parallel for heat exchange, and then heat-exchanged with the solvent vapor at the top of the first evaporation tower, and then divided into two shares, which are respectively parallel-connected with the condensate of the solvent recovered from the second and third evaporation towers. heat, and then exchange heat with the steam partially condensed from the solvent at the top of the second evaporation tower. Specifically, in the process of preheating the furfural feed to the three-tower evaporation recovery, the feed is first divided into three equal shares, and the first, second and second The solvent condensate at the top of the third evaporation tower is heat-exchanged to cool the temperature from 165 to 175°C to 155 to 160°C, and then it exchanges heat with the solvent vapor at the top of the first evaporation tower, and then divides the material into two strands to be evaporated with the second and third evaporation towers respectively. The condensate of the solvent recovered in the tower is exchanged to reduce the temperature from 175 to 190°C to 165 to 175°C. During the preheating process of the feed to the second evaporation tower, the second evaporation tower is partially condensed and heated by the solvent vapor at the top of the second evaporation tower. Self-feeding, and then fully condensed to 175 to 190°C with the top steam of the third evaporation tower for heating, the preheating of the first and second evaporation tower feeds must be carried out at the same time, in order to obtain the maximum energy saving and reduce the heat transfer area , the pressure of the first evaporation tower is 0.1 to 0.18 MPa absolute pressure, the temperature is 165 to 180 ° C, the solvent vapor at the top of the tower undergoes two heat exchanges in sequence, the first time is a condenser, and the second time is a heat exchanger, so The pressure of the second evaporation tower described above is 0.15 to 0.21MPa absolute pressure, and the temperature is 175 to 190°C. The solvent vapor at the top of the tower undergoes four heat exchanges in sequence, the first and second times are condensers, and the third and fourth times are heat exchangers , the pressure of the third evaporation tower is 0.2 to 0.25 MPa absolute pressure, and the temperature is 195 to 220 ° C. The solvent vapor at the top of the tower undergoes three heat exchanges in sequence, the first is a condenser, and the second and third are heat exchangers. 2、根据权利要求1所述的方法,其特征在于所述的溶剂可以是糠醛,N-甲基吡咯烷酮,甲乙基酮-甲苯,甲乙基酮-甲苯-苯,甲基异丁基酮-甲苯,甲基异丁基酮-甲苯-苯等与石油烃类混合物中溶剂的回收。2. The method according to claim 1, characterized in that said solvent can be furfural, N-methylpyrrolidone, methyl ethyl ketone-toluene, methyl ethyl ketone-toluene-benzene, methyl isobutyl ketone-toluene , Recovery of solvents in mixtures of methyl isobutyl ketone-toluene-benzene and petroleum hydrocarbons.
CN91110451A 1991-11-08 1991-11-08 Process for recovering solvent during hydrocarbon processing Expired - Lifetime CN1020745C (en)

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CN91110451A CN1020745C (en) 1991-11-08 1991-11-08 Process for recovering solvent during hydrocarbon processing

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Application Number Priority Date Filing Date Title
CN91110451A CN1020745C (en) 1991-11-08 1991-11-08 Process for recovering solvent during hydrocarbon processing

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CN1059851A true CN1059851A (en) 1992-04-01
CN1020745C CN1020745C (en) 1993-05-19

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CN91110451A Expired - Lifetime CN1020745C (en) 1991-11-08 1991-11-08 Process for recovering solvent during hydrocarbon processing

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1062007C (en) * 1997-11-11 2001-02-14 中国石油化工总公司 Process for regenerating aromatic hydrocarbon extraction solvent
CN100593561C (en) * 2007-12-06 2010-03-10 中国石油化工集团公司 Heat Exchange Method in Solvent Recovery System of Ketobenzene Dewaxing Unit

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101280215B (en) * 2008-05-23 2011-07-20 金碧华 Production process of batch process of catalytic oil slurry

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1062007C (en) * 1997-11-11 2001-02-14 中国石油化工总公司 Process for regenerating aromatic hydrocarbon extraction solvent
CN100593561C (en) * 2007-12-06 2010-03-10 中国石油化工集团公司 Heat Exchange Method in Solvent Recovery System of Ketobenzene Dewaxing Unit

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