DE1098207B - Process for the production of resins from pyrolysis products of petroleum hydrocarbons - Google Patents

Description

Process for the production of resins from pyrolysis products of petroleum hydrocarbons It is known that resins from individual fractions of the pyrolysis products of hydrocarbons, for example petroleum, can be produced by polymerization. So far is however, it has only been possible to resin a small proportion of the cracked products to polymerize of a satisfactory nature, so that the resin yield in the generally only a small percentage of the starting product for the cracking process darsteDt. In addition, the nature of the resins generally depends on the Starting material for the cracking process and the cracking conditions. This makes the control of the resin properties in the process is difficult or impossible, in which the resins are obtained in relatively small quantities as by-products, in particular also because the reasons for the changes in the resin composition so far only are little known.

The invention relates to an improved method of manufacture of resins from the pyrolysis products of petroleum hydrocarbons. According to the invention such starting materials and cracking conditions are selected as compared with the known processes give high yields of resin-forming fractions. This gives the opportunity to use the resins as the main products of an economically viable one Prepare process in which the cracking and polymerization conditions are sufficient Can be controlled to make resins of the desired texture and with consistent Properties to produce. The process uses starting materials found in unlimited quantity are available at low cost, and supplies, in particular in terms of softening point and color, resins of high quality.

The production of resins from pyrolysis products according to the invention of petroleum hydrocarbons, is an aromatic concentrate of a petroleum fraction with the boiling range from 150 to 350 ° C at temperatures between 600 and 800 ° C thermal cracked, from the cracked products a fraction with a boiling range from 150 to 300 ° C separated and in a known manner in the presence of Friedel-Crafts catalysts polymerized. The starting material for the process according to the invention comprises aromatic concentrates of petroleum fractions that boil within 150 and 350 ° C.

In particular, aromatic extracts are suitable that are used in the production of kerosene from petroleum fractions with a boiling range of 150 to 300 ° C, preferably 200 to 300 ° C, are obtained. The aromatic concentrate should at least 60%, preferably about 75D / o or more of aromatic hydrocarbons. It can e.g. B. by extracting the petroleum fractions with liquid sulfur dioxide can be obtained under pressure. Such extraction can be carried out in columns or otherwise Devices at temperatures carried out in the range of about -12 to about -50 ° C will. At the top of the extraction column, a raffinate fraction is withdrawn contains only a small percentage of aromatic hydrocarbons while at the bottom of the column an extract with 70 to 80% aromatic hydrocarbons is won. If the extraction conditions are changed, higher or lower Aromatic concentrations are obtained. The aromatic extracts are made by heating freed of sulfur dioxide and the last traces of sulfur dioxide by washing removed with water or soda. Other processes for the production of aromatic concentrates from petroleum fractions are, for example, solvent extractions with solvents such as furfural, nitrobenzene or phenol.

The cracking is carried out in a known manner by heating the aromatic concentrate in the vapor phase to temperatures of 600 to 800 ° C., preferably in the presence carried out by steam or another inert diluent. Here generally results in the use of higher cracking temperatures within the range of resins with a higher softening point and slightly better color, however, the yield of the resin-forming fraction decreases with increasing cracking temperature. On the other hand becomes at temperatures below about 6p @ ° G The resin yield is too low to be of any practical interest. Preferably cracking temperatures between about 600 and 750 ° C are used, the lower Temperatures in this range for cracking in the absence of a diluent are suitable, while the higher temperatures of this range are preferable, if thinners such as steam are used ..'-.! The resin yield is generally higher when cracking in the presence of steam or a other diluents is carried out, and as with the known. Steam cracking process, Here, too, the steam contributes to the prevention of coke deposition and side reactions of the cracked products.

Amounts of steam in the range from 0.1 to 10 moles per mole of hydrocarbon are suitable. For cracking, the hydrocarbon feedstock is through a Preheater out in which the liquid is evaporated at elevated temperatures, however, which are preferably below those in the cracking stage. The inert Diluent is preferably heated separately and the two streams entering combined in the cracking stage. The residence time in the cracking zone is not critical, and times in the range of about 0.1 to 10 seconds, preferably about 1 second, can be used. Generally at lower cracking temperatures longer residence times are required.

The cracked products are used for the subsequent polymerization a fraction with the boiling range from 150 to 300 ° C is separated. The cracked ones Products are made, for example, by injecting water or oil into the output stream from the cracking zone are first cooled, and after further cooling the gaseous Cracked products consisting mainly of hydrogen, metane, athan, ethylene and propylene and smaller amounts of propane, separated from the higher hydrocarbons.

Then the condensed liquid is used to obtain a Fraction with a final boiling point of about 150 ° C, the main resin-forming fraction distilled with the boiling range from 150 to 300 ° C and a small residue.

In a preferred embodiment, a first fraction is up to separated to a final boiling point of about 200 ° C to be used as a mixed component with high Find octane number for gasoline use. Then from 200 to 300 ° C a resin-forming fraction obtained.

The resin-forming fraction is then present in a known manner polymerized by Friedel-Crafts catalysts. Suitable catalysts are, for example Aluminum chloride or boron trifluoride, either in free or complex form. Aluminum chloride can for example as a finely divided solid or as a liquid complex with aromatic hydrocarbons such as xylene can be used. These complexes can made by stirring solid aluminum chloride with aromatic hydrocarbons will. They form quickly when heated, for example in the case of xylene to about 80 ° C and can easily be removed as a dark-colored, opaque layer the supernatant clear liquid are separated.

Solid aluminum chloride can be added to the liquid complex, to increase or maintain its catalytic activity. Boron trifluoride or its complexes with, for example, diethyl ether, acetic acid or phenol preferably in amounts of 0.01 to 1 percent by weight, based on the starting product in polymerization.

The polymerization can be carried out batchwise or continuously and one sufficient to mix the catalyst and the hydrocarbon Exercise is desirable. The reaction can take place at temperatures in the range of -50 Carried out up to 150 ° C ß1verden.-Since the reaction is exothermic, it is necessary to control the temperature and dissipate the heat of reaction. The response time is not critical and times up to 6 hours have been found suitable. Possibly can polymerize in the presence of added solvents such as inert hydrocarbons or other non-reactive material: After deF Pg1yurisation the catalyst is removed and then with alkali, for example with a Washed dilute, aqueous sodium carbonate solution to remove the last traces of the remove acidic products.

To obtain the resin, those boiling up to about 300 ° C can then be used Hydrocarbons are withdrawn. These can be obtained as by-products, or they are preferably returned to the cracking stage, the resin remains as Backlog. This resin can be obtained by heating in vacuum, in steam or Inert gas atmosphere can be treated to the desired softening point.

The invention is explained in more detail in the flow diagram.

An aromatic concentrate of a petroleum fraction is produced from the storage container 1 taken with the boiling range from 150 to 350 ° C and in the. Reaction stage 2 with Washed 98 ° lOiger sulfuric acid. The acid tar is left as a residue in the tank 3 separated and the acid-washed concentrate in the column 4 under delivery distilled from about 5 weight percent residue. This residue can be used as a fuel component be used. The acid-washed and distilled starting material is used in the Container 5 stored. From this it becomes together with a recycle stream from the, column 14 transferred to the cracking stage The products from this cracking zone are in the Tower 7 cooled with water and the low-boiling (up to about 150 ° C) and gaseous Fractions drawn off overhead in the separation stage 8, in which they are converted into cracked gases and gasoline be divided. The residue from the cooling tower 7 is transferred to the column 9, A fraction with the boiling range from 150 to 300 ° C. was drawn off from the overhead and placed in the storage container 10. The over 300 ° C boiling residue in the column 9 is a pitch-like product.

The 150 to 300 ° C fraction of the pyrolysis product is in the device 11 polymerized batchwise and then the polymerized product in the Reaction stage 12 freed from the catalyst. The reaction product free of the catalyst is stored in the container 13. It is from this container into the columns 14 transferred, in which the 150 to 300 ° C fraction is withdrawn as a distillate and is fed back into the pyrolysis.

The resin from the column 4 is more than 300 ° Ct 760 mm boiling Backlog won.

Example 1 A crude kerosene from a Middle East crude with a boiling range of 150 to 250 ° C is under pressure with liquid sulfur dioxide extracted, an extract with 80% aromatic hydrocarbons receives. This extract is broken down into two fractions by distillation, one of which the first (A) between 150 and 210 ° C and the second (B) between 210 and 250 ° C boils. These two fractions of the aromatic extract are separated in the presence of steam at temperatures of 600 ° C and an addition ratio cracked by 0.6 parts by volume of liquid per volume of reactor per hour. The water vapor is used in amounts of 10 moles of steam per 1 mole of hydrocarbon. From the cracked ones Products is distilled to a fraction with a boiling range from 150 to 300 ° C obtained and with 0.4 percent by weight boron trifluoride diethyl ether complex 60 ° C polymerized for 2 hours. The polymerization products are initially washed with 15% aqueous sodium carbonate solution and then with water and dried. The resins are then made by distilling off the unreacted hydrocarbons obtained at a pressure of 1 mm Hg up to a head temperature of 300 ° C / 760 mm. You will be by determining the Bromine number based on that of Kaufmann and Barich in Arch. Pharm., 267, pp. 1 to 27 (1929), described method and by determining the softening point characterized by the ring and ball method, I. P. 58/56. The results are included in table 1.

The unextracted, crude kerosene was used for comparison (C) that was used as the original raw material, and that with sulfur dioxide extracted luminescent petroleum raffinate (D) steam cracked and the within 150 to 300 ° C boiling crack products, as described above, polymerized. The results in Table 1 show that Aromatic Concentrates A and B have high yields of resins with a high softening point, while the crude kerosene and the refined kerosene (C and D) soft resins of low value give significantly lower yields.

Table 1 ABCD Cracked products Uncondensed gas, percent by weight of the starting materials 7 7 20 22 150 to 300 ° C fraction, percent by weight of the starting materials 88 78 70 60 Other liquid products, percentage by weight of the raw material ................................. 5 15 10 18 Polymerization products Hydrocarbons Recovered, Weight Percent of the starting material for the cracking stage ......... 83 68 65 58 Resin, weight percent of the starting material for the Crack level 5 10 3, 5 1, 3 Resin, weight percent of the starting material for the Polymerization 6 13 5 2, 2 Resin properties Softening point, ° C 79 90, 5 <40 <40 Bromine number ....................................... 31 35 49 13 Color p .......................................... dark medium medium medium Example 2 A crude kerosene from a Middle East crude oil with a boiling range from 150 to 250 ° C. is extracted with sulfur dioxide, whereby an aromatic concentrate with 80% aromatic hydrocarbons is obtained. Samples E through K of the concentrate are thermally cracked at various temperatures and the products are treated as in Example 1 to produce a resin. No steam is introduced during cracking. Table 2 shows the results obtained.

The results show that in the absence of a diluent Resins satisfactory at cracking and at the indicated feed rates can be produced at temperatures above about 600 ° C. For the production of satisfactory resins in high yields, temperatures above 650 ° C. are desirable.

Table 2 EFGHIJK Cracking conditions Temperature, ° C 550 625 625 625 625 675 700 Oil supply Volume of liquid / reactor volume / hour 6, 2 2, 6 6, 2 8, 6 6, 2 6, 1 6, 3 Cracked products Uncondensed gas, percent by weight of the starting materials 1 11 9 5 12 18 28 150 to 300 ° C fraction, percent by weight of the starting materials 99 79 76 92 75 70 55 Other liquid products, percentage by weight of the raw material ................................ - 10 15 3 13 12 17 Port setting Table 2 EFGHIJK Polymerization products Recovered hydrocarbons, weight percent of the starting material for the cracking stage ......... 96, 7 70 69 86 65 56 4 Resin, percent by weight of the starting material for the 0 Crack level 2, 3 9 7 6 10 14 1, 5 Resin, weight percent of the starting material for the Polymerization .............................. 2, 3 11, 2 9, 6 6, 8 13 19, 3 265 Resin properties Softening point, ° C 40 76 69, 5 64 84 97 114 Bromine number 43 50 35 11 20 Dark medium color Example 3 The starting material of Example 2 is cracked in the presence of 5 moles of water vapor per mole of hydrocarbon. The cracked products are treated as in Example 1. From the results of experiments L, M, N, given in Table 3, it can be seen that higher resin yields are obtained in the presence of steam than in the absence of steam (cf. Example 2).

The optimal temperature is around 700 ° C.

Table 3 L M N Cracking conditions Temperature, ° C ..................... ..... 675 700 725 Oil supply, Volume liquid / reactor volume / hour ..... 1, 9 1, 7 1, 7 Cracked products Uncondensed gas, percent by weight of the starting materials 13 22 31 150 to 300 ° C fraction, percent by weight of the starting materials ..................................... 76 66 50 Other liquid products, percentage by weight of the Transition material ........................... 11 12 19 Polymerization products Hydrocarbons Recovered, Weight Percent of the raw material for the cracking stage .......... 56 48 35 Resin, percent by weight of the starting material for the Crack level ........................................ 20 18 15 Resin, weight percent of the starting material for the 26, 26, 2 27, 0 31, 1 Resin properties Softening point, ° C 90 102 124 Bromza. 30 22 15 Color. 1 medium medium Example 4 A crude kerosene from a Middle East crude oil with a boiling range from 150 to 250 ° C. is extracted with sulfur dioxide, and an aromatic concentrate with 80% aromatic hydrocarbons is obtained. This concentrate is thermally cracked at 650 ° C. and a feed rate of 6.2 parts by volume of the liquids / reactor volume / hour in the absence of a diluent and the fraction of the cracked products boiling from 150 to 300 ° C. is polymerized as in Example 1. The resinous products of experiment O are separated off and the recovered hydrocarbon distillate is cracked and the cracking products obtained here are polymerized under the same reaction conditions (P).

The results in Table 4 show that from the polymerization stage withdrawn hydrocarbons can be returned to the cracking stage and that here resins in the first resins of comparable quality approximately the same yields can be obtained. The total yield of resin based on the starting product of experiment O is 16 percent by weight.

Table 4 0 p Cracked products Uncondensed gas, percent by weight of the starting materials 12 7 150 to 300 ° C fraction, percent by weight of the starting materials 70 78 Other liquid products, percentage by weight of the gang material 18 15 Polymerization products Recovered hydrocarbons, weight percent of the starting material for the cracking stage ......... 61 67 Resin, weight percent of the starting material for the Crack level 9 11 Resin, weight percent of the starting material for the Polymerization 13, 2 14, 5 Resin properties Softening point, ° C 86 83 Bromine number ....................................... 35 22 Color medium medium Example 5 A crude kerosene, obtained from a Middle East crude oil with a boiling range of 150 to 250 ° C., is extracted with sulfur dioxide and an aromatic concentrate with 80% aromatic hydrocarbons is obtained. This concentrate is thermally cracked at 675 ° C. in the absence of a diluent and the fraction of the cracked products boiling from 150 to 300 ° C. is polymerized using various catalysts. The polymers are freed from the catalysts and then distilled in order to obtain the resin boiling above 300.degree.

The results are shown in Table 5.

Table 5 Weight percent resin yield, resin properties Starting Weight Percent Catalyst Color Softening of the initial (Barret point in Scale) ° C Boron trifluoride diethyl ether complex 4 28, 6 2, 5 to 3 113 Stearic acid chloride 1, 0 30, 5 3, 5 113 Aluminum chloride ................................. 12 35, 0 75 85

Claims (3)

PATENT CLAIMS: 1. Process for producing resins from pyrolysis products of petroleum hydrocarbons by polymerizing one by cracking a petroleum distillate obtained petroleum fraction in the presence of Friedel-Crafts catalysts, thereby characterized in that a resin-forming fraction with the boiling range for the polymerization from 150 to 300 ° C is used, from an aromatic concentrate one at 150 Petroleum fraction boiling up to 350 ° C has been obtained by cracking at 600 to 800 ° C is. 2. The method according to claim 1, characterized in that for the thermal cracking an aromatic concentrate from a petroleum fraction with a Boiling range from 150 to 300 ° C, preferably 200 to 300 ° C, and in particular a content of at least 60%, suitably at least 75%, of aromatic hydrocarbons is used. 3. Process according to Claims 1 and 2, characterized in that the polymerization products freed from the catalyst, washed with alkali and separated from the hydrocarbons boiling up to 300 ° C by distillation, which are returned to the cracking stage. Documents considered: French patent specification No. 1088401; British Patent No. 737231.