US3617478A - Suppression of coke formation in a thermal hydrocarbon cracking unit - Google Patents
Suppression of coke formation in a thermal hydrocarbon cracking unit Download PDFInfo
- Publication number
- US3617478A US3617478A US56264A US3617478DA US3617478A US 3617478 A US3617478 A US 3617478A US 56264 A US56264 A US 56264A US 3617478D A US3617478D A US 3617478DA US 3617478 A US3617478 A US 3617478A
- Authority
- US
- United States
- Prior art keywords
- cracking
- hydroxide
- potassium carbonate
- hydrocarbon
- potassium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 229930195733 hydrocarbon Natural products 0.000 title claims abstract description 42
- 150000002430 hydrocarbons Chemical class 0.000 title claims abstract description 42
- 238000005336 cracking Methods 0.000 title claims abstract description 40
- 239000004215 Carbon black (E152) Substances 0.000 title claims abstract description 39
- 239000000571 coke Substances 0.000 title claims abstract description 21
- 230000015572 biosynthetic process Effects 0.000 title abstract description 13
- 230000001629 suppression Effects 0.000 title description 3
- 238000010791 quenching Methods 0.000 claims abstract description 38
- 239000007864 aqueous solution Substances 0.000 claims abstract description 19
- 230000000171 quenching effect Effects 0.000 claims abstract description 19
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 claims description 54
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 claims description 33
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 30
- 229910000027 potassium carbonate Inorganic materials 0.000 claims description 27
- 235000011181 potassium carbonates Nutrition 0.000 claims description 27
- 238000000034 method Methods 0.000 claims description 26
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 claims description 22
- 229910000029 sodium carbonate Inorganic materials 0.000 claims description 11
- TYJJADVDDVDEDZ-UHFFFAOYSA-M potassium hydrogencarbonate Chemical compound [K+].OC([O-])=O TYJJADVDDVDEDZ-UHFFFAOYSA-M 0.000 claims description 6
- 239000011736 potassium bicarbonate Substances 0.000 claims description 4
- 229910000028 potassium bicarbonate Inorganic materials 0.000 claims description 4
- 235000015497 potassium bicarbonate Nutrition 0.000 claims description 4
- 235000017550 sodium carbonate Nutrition 0.000 claims description 4
- 235000011118 potassium hydroxide Nutrition 0.000 claims description 3
- 235000011121 sodium hydroxide Nutrition 0.000 claims description 3
- 239000000243 solution Substances 0.000 claims description 2
- -1 alkali metal salt Chemical class 0.000 abstract description 11
- 229910052783 alkali metal Inorganic materials 0.000 abstract description 9
- 238000004227 thermal cracking Methods 0.000 abstract description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 abstract description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 13
- 239000007789 gas Substances 0.000 description 9
- 150000001335 aliphatic alkanes Chemical class 0.000 description 5
- 150000004679 hydroxides Chemical class 0.000 description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- 229910052799 carbon Inorganic materials 0.000 description 4
- 238000001816 cooling Methods 0.000 description 4
- 238000007689 inspection Methods 0.000 description 4
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 3
- 239000005977 Ethylene Substances 0.000 description 3
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 description 3
- 150000008044 alkali metal hydroxides Chemical class 0.000 description 3
- 125000003118 aryl group Chemical group 0.000 description 3
- 238000005235 decoking Methods 0.000 description 3
- 230000007062 hydrolysis Effects 0.000 description 3
- 238000006460 hydrolysis reaction Methods 0.000 description 3
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 3
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 3
- 238000011144 upstream manufacturing Methods 0.000 description 3
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000003921 oil Substances 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 238000010517 secondary reaction Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- UIIMBOGNXHQVGW-DEQYMQKBSA-M Sodium bicarbonate-14C Chemical compound [Na+].O[14C]([O-])=O UIIMBOGNXHQVGW-DEQYMQKBSA-M 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- RQPZNWPYLFFXCP-UHFFFAOYSA-L barium dihydroxide Chemical compound [OH-].[OH-].[Ba+2] RQPZNWPYLFFXCP-UHFFFAOYSA-L 0.000 description 1
- 229910001863 barium hydroxide Inorganic materials 0.000 description 1
- AYJRCSIUFZENHW-DEQYMQKBSA-L barium(2+);oxomethanediolate Chemical compound [Ba+2].[O-][14C]([O-])=O AYJRCSIUFZENHW-DEQYMQKBSA-L 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 238000004939 coking Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 239000000295 fuel oil Substances 0.000 description 1
- 239000003350 kerosene Substances 0.000 description 1
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 description 1
- 229910052808 lithium carbonate Inorganic materials 0.000 description 1
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 description 1
- 239000000347 magnesium hydroxide Substances 0.000 description 1
- 229910001862 magnesium hydroxide Inorganic materials 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000000197 pyrolysis Methods 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000003911 water pollution Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C4/00—Preparation of hydrocarbons from hydrocarbons containing a larger number of carbon atoms
- C07C4/02—Preparation of hydrocarbons from hydrocarbons containing a larger number of carbon atoms by cracking a single hydrocarbon or a mixture of individually defined hydrocarbons or a normally gaseous hydrocarbon fraction
- C07C4/06—Catalytic processes
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C4/00—Preparation of hydrocarbons from hydrocarbons containing a larger number of carbon atoms
- C07C4/02—Preparation of hydrocarbons from hydrocarbons containing a larger number of carbon atoms by cracking a single hydrocarbon or a mixture of individually defined hydrocarbons or a normally gaseous hydrocarbon fraction
- C07C4/04—Thermal processes
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C5/00—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms
- C07C5/32—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms by dehydrogenation with formation of free hydrogen
- C07C5/321—Catalytic processes
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
- C10G9/00—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
- C10G9/14—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils in pipes or coils with or without auxiliary means, e.g. digesters, soaking drums, expansion means
- C10G9/16—Preventing or removing incrustation
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C2523/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group C07C2521/00
- C07C2523/02—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group C07C2521/00 of the alkali- or alkaline earth metals or beryllium
- C07C2523/04—Alkali metals
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C2527/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- C07C2527/20—Carbon compounds
- C07C2527/232—Carbonates
-
- Y—GENERAL 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
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S585/00—Chemistry of hydrocarbon compounds
- Y10S585/949—Miscellaneous considerations
- Y10S585/95—Prevention or removal of corrosion or solid deposits
Abstract
Coke formation and deposits in the inline heat exchanger of a thermal hydrocarbon cracking unit comprised of a thermal-cracking zone, a quenching apparatus and the heat exchanger are removed and prevented by introducing an aqueous solution of an alkali metal salt or hydroxide into the hydrocarbon flow at a point downstream of the cracking zone of the unit.
Description
United States Patent m13,617,478
[72] Inventors James Ely King, Jr. [51] Int. Cl Cl0g 9/16, Groves; C07c 5/18, C070 11/06 Sidney Theodore Jones, Port Neches, both [50] Field of Search 208/48 of Tex.
[2]] Appl 5 2 4 [56] References Cited [22] Filed July 20, 1970 UNITED STATES PATENTS 1 Palmed Nov-2, 1971 2,893,941 7/1959 Kohfeldt 208/48 [73} Assrgnee Jefferson Chemical Company, Inc. I
Houston Tex. Primary Examiner-Delbert E. Gantz Continuation-impart of application Ser. No. 872,220, Oct. 29, 1969, now abandoned.
[54] SUPPRESSION OF COKE FORMATION IN A THERMAL HYDROCARBON CRACKING UNIT 9 Claims, 2 Drawing Figs.
52 U.S. Cl 208/48 AA, 260/683 R Assistant Examiner-G. E. Schmitkons Attorneys-John R. Kirk, Jr. and H. G. Jackson ABSTRACT: Coke formation and deposits in the inline heat exchanger of a thermal hydrocarbon cracking unit comprised of a thermal-cracking zone, a quenching apparatus and the heat exchanger are removed and prevented by introducing an aqueous solution of an alkali metal salt or hydroxide into the hydrocarbon flow at a point downstream of the cracking zone of the unit.
PATENTED 2 I 7 3.617, 47 8 JAMES E. KING, SIDNEY T- JONES,
INVEN'I'URS.
ATTORNEY- SUPPRESSION F COKE FORMATION IN A THERMAL HYDROCARBON CRACKING UNIT Cross-Reference to Related Application This application is a continuation-in-part of our copending application Ser. No. 872,220 filed Oct. 29, I969, now abandoned.
BACKGROUND OF THE INVENTION 1. Field of the Invention This invention is a method for prolonging the cycle time between shutdowns of a thermal-cracking unit in which ethylene and propylene are made by the thermal cracking of lower alkanes. Specifically, this invention is a method for decreasing coke buildup in the heat exchanger employed in the cracking unit by introducing an aqueous solution of alkali metal salt or hydroxide into the unit at a point downstream of the cracking zone.
2. Description of the Prior Art Kohfeldts s U.S. Pat. No. 2,893,941 (I959) discloses a process for treating liquid hydrocarbons such as heavy naphtha, kerosene, and gas oil which involves the steps of thermally cracking the hydrocarbon in the presence of potassium carbonate and steam wherein the potassium carbonate is added as an aqueous solution preferably at a point upstream from the thermal-cracking zone. The preferred Kohfeldt teaching was followed by adding an aqueous potassium carbonate solution to a thermal-cracking unit for lower alkanes at a point upstream of the cracking zone and the unit became plugged with coke formation at the in-line heat exchanger within 7 days. The operating time in a unit wherein no potassium carbonate is used is about 7 days; therefore, Kohfeldts preferred process is unworkable in our unit for all practical purposes.
We have found that by adding an aqueous potassium carbonate solution to the process in a unit for making ethylene and propylene or other olefms at a point downstream of the cracking zone, the furnace can operate without plugging for as long as 74 days, a more than ten-fold improvement over in troducing the carbonate to the cracking unit as taught by Kohfeldt's preferred method. And the reason for shutdown of the unit after 74 days operation was not because of plugging due to coke formation in the heat exchanger but because of coke formation in the reactor coil upstream of the quench fitting. Comparable improvements are shown using other alkali metal salts or hydroxides of our invention.
SUMMARY OF THE INVENTION The invention is an improvement in a thermal hydrocarbon cracking process comprised of a thermal-cracking zone, a quenching apparatus and an in-line heat exchanger arranged in series such that the gaseous effluent from the cracking zone flows through the quenching apparatus and then through the exchanger. The improvement is introducing an aqueous solution of alkali metal salt which yields an alkaline product on hydrolysis or an alkali metal hydroxide into the hydrocarbon flow at a point downstream of the cracking zone.
DESCRIPTION OF THE DRAWING The invention will be further illustrated with reference to the accompanyingdrawings. In FIGS. 1 and 2, a feed gas is introduced by means of line 1 into a cracking heater 2 where the gas is heated at a temperature above 1400 F. The effluent gases, at a temperature about l,530 F., pass from the cracking heater 2 by means of line 3 to the quenching apparatus 4. Sufficient water to cool the gases to l,000-l,400 F. is introduced at the top of quenching apparatus 4 in a fine spray by means of line 5 or alternatively by line 3. The addition of an alkali metal salt or hydroxide to the prequench water successfully suppresses the formation of heavy hydrocarbon and prevents coke and polymer formation in the transfer line 6 which feeds the gases to the heat exchanger 7 where they are cooled from the temperature of l,000-l ,400 F. to a temperature of 400-l ,000 F. Quenching apparatus 4 can contain a baffle I0 against which the quenched gases impinge. In the exchanger, the heat removed from the gases is used to generate steam, which may then be used in other plant operations. These cooled gases then pass from heat exchanger 7 by means of line 8 to a quench tower which forms no part of the present invention. Beneath quenching apparatus 4, there can be located a coke collecting vessel 9 which is shown in FIG. 1 as an integral part of the quenching apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENTS In the production of olefinic hydrocarbons such as ethylene, propylene and other cracked products by thermally cracking gaseous and vaporizable liquid hydrocarbons in a tubular pyrolysis furnace at high temperatures in the presence of steam and using short residence time, often referred to as high severity cracking, which is followed by immediate cooling or quenching of the cracked effluent to minimize secondary reactions by direct or indirect cooling means; coke deposits and other cracked deposits often form at critical points in the apparatus. Such deposits cause interruption of onstream time of the cracking furnace and produce a serious economic problem. We have discovered that an aqueous solution of an alkali metal salt which yields an alkaline product on hydrolysis or an alkali metal hydroxide, for example, potassium carbonate, potassium bicarbonate, sodium carbonate, sodium bicarbonate, lithium carbonate, barium carbonate, potassium hydroxide, sodium hydroxide, magnesium hydroxide, barium hydroxide or lithium hydroxide injected in small quantities into the hydrocarbon flow path of prequenching and subsequent cooling apparatus removes or prevents coke deposits and other cracked deposits downstream from the cracking zone. These deposits have been such a problem prior to our discovery that it was necessary to shut down the unit at least every 7 days in order to remove the coke deposits. Aqueous solutions of potassium carbonate, potassium bicarbonate, sodium carbonate, sodium hydroxide or potassium hydroxide are preferred in the practice of our invention. By adding an aqueous solution of these salts or hydroxides downstream from the cracking zone, i.e., in the cooling or quenching apparatus including the quench and coke pots, the quench boilers and transfer line exchangers and connecting'pipin g in the cracked hydrocarbon flow path, coking problems have been reduced significantly. In addition, the quench water is cleaner and less oils are formed when our improvement is used, illustrating a reduction in secondary reactions which thereby abates water pollution because of the reduction of total carbon going into the quench water. By reducing the amount of carbon added to the quench water, less oxygen is removed from the receiving water bodies which are, for example, lakes and rivers. The determination of the amount of total carbon in the quench water is determined by the Beckman Carbonaceous Analyzer and shows a 28 percent reduction in organic carbon in the water. The carbonates or hydroxides may be introduced into the unit in a proportion of I to 200 parts per million of the hydrocarbon feed to the cracking furnace. The preferred range of carbonate is about 20-30 ppm. of the hydrocarbon feed.
To further illustrate the improvement of our invention, a test-cracking furnace was put on stream, after decoking, under normal operating conditions and an aqueous solution of potassium carbonate, 25 to 30 p.p,m. based on the hydrocarbon feed, was continuously injected into the quench pot via the quench water nozzle. After 62 days of operation, the unit was shut down for inspection and repairs. Inspection revealed less coke fouling than normally found after only a few days operation with no potassium carbonate treatment.
A second test showed similar results to those described above. A test-cracking furnace was put on stream after decoking under normal operating conditions. An aqueous solution of potassium carbonate, 25 to 30 ppm. based on hydrocarbon feed, was continuously injected into the quench pot via the quench water nozzle. After 41 days on stream, the furnace was shut down prematurely for-- inspection. Inspection revealed no coke deposits in the quench pot or on the surface of the connecting pipe up and down stream of the transfer line exchanger and there was less coke on the inlet tube sheet of the transfer line exchanger that previously encountered after only a few days operating time without using potassium carbonate. A similar furnace run was made for cracking lower alkanes wherein an aqueous solution of sodium carbonate, 25 to 30 p.p.m. based on hydrocarbon feed, was continuously injected into the quench pot via the quench water nozzle. After 35 days of operation, the unit was still running with no indication of coke buildup in the in-line heat exchanger. A further similar furnace run was made for cracking lower alkanes wherein an aqueous solution of potassium hydroxide, 25 to 30 p.p.m. based on hydrocarbon feed, was continuously injected into the quench pot via the quench water nozzle. After 35 days of operation, the unit was still running with no indication of coke buildup in the in-line heat exchanger. Comparable results are obtained using other salts or hydroxides of our invention.
In an attempt to carry out the addition of potassium carbonate to the cracking zone as taught in the preferred method of Kohfeldts U.S. Pat. No. 2,893,941, a test-cracking furnace was put on stream after decoking under normal operating conditions and an aqueous solution of 25 to 30 p.p.m. potassium carbonate based on the hydrocarbon feed was continuously injected into the cracking zone with the hydrocarbon. The unit had to be shut down after 7 days of operation due to plugging caused by coke formation in the transfer line exchanger.
To further illustrate the improvement of our invention, testcracking furnaces for cracking lower alkanes were operated under normal conditions while an aqueous solution of potassium carbonate, 25 to 30 p.p.m. based on the hydrocarbon feed,
1 GaL/M. lbs. C2H
was continuously injected into the quench pots via the quench water nozzles for a period of 3 months. The formation of heavy oils, hydrocarbon polymer and aromatic distillate was measured and compared to the same formation accumulated in 3 months in a unit where no potassium carbonate was used. The data in the following table illustrate the decrease in heavy hydrocarbon production when our improvement is used. Even though the aromatic distillate decreases when our process is used, better quality products in the aromatic distillate are obtained.
We claim:
1. In a thermal hydrocarbon cracking process wherein the hydrocarbon cracking apparatus comprises a thermalcracking zone, a quenching apparatus and an in-line heat exchanger arranged in series such that the gaseous effluent from the cracking zone flows through the quenching apparatus and then through the exchanger, the improvement which comprises introducing an aqueous solution of alkali metal salt which yields an alkaline product on hydrolysis or an alkali metal hydroxide into the hydrocarbon flow at a point downstream of the cracking zone. 2. A process according to claim 1 wherein the aqueous solution is of potassium carbonate, potassium bicarbonate, sodium carbonate, sodium hydroxide or potassium hydroxide.
3. A process according to claim 2 wherein the aqueous solution is of potassium carbonate, sodium carbonate, potassium hydroxide or sodium hydroxide and the solution is introduced into the hydrocarbon flow at the quenching apparatus.
4. A process according to claim 3 wherein the potassium carbonate, sodium carbonate, potassium hydroxide or sodium hydroxide is fed to the apparatus in a proportion of l to 200 p.p.m. of the hydrocarbon feed to the cracking zone.
5. A process according to claim 4 wherein the potassium carbonate, sodium carbonate, potassium hydroxide, or sodium hydroxide is in a proportion of about 20 to 30 p.p.m. of the hydrocarbon feed.
6. A process according to claim 3 wherein potassium carbonate is introduced into the hydrocarbon flow at the quenching apparatus.
7. A process according to claim 6 wherein potassium carbonate is fed to the apparatus in a proportion of l to 200 p.p.m. of the hydrocarbon feed to the cracking zone.
8. A process according to claim 7 wherein the potassium carbonate is in a proportion of about 20 to 30 p.p.m. of the hydrocarbon feed.
9. A process according to claim 8 wherein a coke collecting vessel is mounted beneath the quenching apparatus and open thereto.
i i 1 i l UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,617 ,478 Dated November 2, 1971 James Ely King, Jr. Sidney Theodore Jones Assignors to Jefferson Chemical Company, Inc. Houston, Texas, a corporation of Delaware It is certified that error appears in the aboveidentified patent and that said Letters Patent are hereby corrected as shown below:
Column 1, line 21, the "s' following "Kohfeldt' s" should be omitted. Column 3, line 2 of table, "C following "Ethylene and propylene" should be omitted; Column 3, following the table, the following sentence has been omitted Comparable results to those in the Table, supra, are obtained with the other alkali metal salts and hydroxides of our invention.
Signed and sealed this 6th day of June 1972.
(SEAL) Attest:
EDWARD M.FLETCH.EJR,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents
Claims (8)
- 2. A process according to claim 1 wherein the aqueous solution is of potassium carbonate, potassium bicarbonate, sodium carbonate, sodium hydroxide or potassium hydroxide.
- 3. A process according to claim 2 wherein the aqueous solution is of potassium carbonate, sodium carbonate, potassium hydroxide or sodium hydroxide and the solution is introduced into the hydrocarbon flow at the quenching apparatus.
- 4. A process according to claim 3 wherein the potassium carbonate, sodium carbonate, potassium hydroxide or sodium hydroxide is fed to the apparatus in a proportion of 1 to 200 p.p.m. of the hydrocarbon feed to the cracking zone.
- 5. A process according to claim 4 wherein the potassium carbonate, sodium carbonate, potassium hydroxide, or sodium hydroxide is in a proportion of about 20 to 30 p.p.m. of the hydrocarbon feed.
- 6. A process according to claim 3 wherein potassium carbonate is introduced into the hydrocarbon flow at the quenching apparatus.
- 7. A process according to claim 6 wherein potassium carbonate is fed to the apparatus in a proportion of 1 to 200 p.p.m. of the hydrocarbon feed to the cracking zone.
- 8. A process according to claim 7 wherein the potassium carbonate is in a proportion of about 20 to 30 p.p.m. of the hydrocarbon feed.
- 9. A process according to claim 8 wherein a coke collecting vessel is mounted beneath the quenching apparatus and open thereto.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US5626470A | 1970-07-20 | 1970-07-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3617478A true US3617478A (en) | 1971-11-02 |
Family
ID=22003271
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US56264A Expired - Lifetime US3617478A (en) | 1970-07-20 | 1970-07-20 | Suppression of coke formation in a thermal hydrocarbon cracking unit |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US3617478A (en) |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4599480A (en) * | 1985-07-12 | 1986-07-08 | Shell Oil Company | Sequential cracking of hydrocarbons |
| US4692313A (en) * | 1981-12-17 | 1987-09-08 | Showa Denko Kabushiki Kaisha | Apparatus for thermal cracking of or heating of hydrocarbons |
| US4889614A (en) * | 1989-05-09 | 1989-12-26 | Betz Laboratories, Inc. | Methods for retarding coke formation during pyrolytic hydrocarbon processing |
| US5034114A (en) * | 1989-07-28 | 1991-07-23 | Ira Kukin | Acid neutralizing combustion additive with detergent builder |
| US5358626A (en) * | 1993-08-06 | 1994-10-25 | Tetra International, Inc. | Method for retarding corrosion and coke formation and deposition during pyrolytic hydrocarbon procssing |
| US5567305A (en) * | 1993-08-06 | 1996-10-22 | Jo; Hong K. | Method for retarding corrosion and coke formation and deposition during pyrolytic hydrocarbon processing |
| WO1998011174A1 (en) * | 1993-08-06 | 1998-03-19 | Jo Hong K | Method for retarding corrosion and coke formation and deposition during pyrolytic hydrocarbon processing |
| US5824829A (en) * | 1993-12-16 | 1998-10-20 | Baker Hughes Incorporated | Hydrocarbon viscosity inhibitor and inhibiting method |
| US5944961A (en) * | 1998-02-23 | 1999-08-31 | Gandman; Zalman | Injecting liquid solution into a thermal cracking gaseous process stream |
| US6228253B1 (en) * | 1997-06-05 | 2001-05-08 | Zalman Gandman | Method for removing and suppressing coke formation during pyrolysis |
| US20080128330A1 (en) * | 2006-12-05 | 2008-06-05 | Mccoy James N | Apparatus and method of cleaning a transfer line heat exchanger tube |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2893941A (en) * | 1955-01-27 | 1959-07-07 | Exxon Research Engineering Co | Removing and preventing coke formation in tubular heaters by use of potassium carbonate |
-
1970
- 1970-07-20 US US56264A patent/US3617478A/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2893941A (en) * | 1955-01-27 | 1959-07-07 | Exxon Research Engineering Co | Removing and preventing coke formation in tubular heaters by use of potassium carbonate |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4692313A (en) * | 1981-12-17 | 1987-09-08 | Showa Denko Kabushiki Kaisha | Apparatus for thermal cracking of or heating of hydrocarbons |
| US4599480A (en) * | 1985-07-12 | 1986-07-08 | Shell Oil Company | Sequential cracking of hydrocarbons |
| US4889614A (en) * | 1989-05-09 | 1989-12-26 | Betz Laboratories, Inc. | Methods for retarding coke formation during pyrolytic hydrocarbon processing |
| US5034114A (en) * | 1989-07-28 | 1991-07-23 | Ira Kukin | Acid neutralizing combustion additive with detergent builder |
| US5358626A (en) * | 1993-08-06 | 1994-10-25 | Tetra International, Inc. | Method for retarding corrosion and coke formation and deposition during pyrolytic hydrocarbon procssing |
| US5567305A (en) * | 1993-08-06 | 1996-10-22 | Jo; Hong K. | Method for retarding corrosion and coke formation and deposition during pyrolytic hydrocarbon processing |
| WO1998011174A1 (en) * | 1993-08-06 | 1998-03-19 | Jo Hong K | Method for retarding corrosion and coke formation and deposition during pyrolytic hydrocarbon processing |
| US5824829A (en) * | 1993-12-16 | 1998-10-20 | Baker Hughes Incorporated | Hydrocarbon viscosity inhibitor and inhibiting method |
| US6228253B1 (en) * | 1997-06-05 | 2001-05-08 | Zalman Gandman | Method for removing and suppressing coke formation during pyrolysis |
| US5944961A (en) * | 1998-02-23 | 1999-08-31 | Gandman; Zalman | Injecting liquid solution into a thermal cracking gaseous process stream |
| US20080128330A1 (en) * | 2006-12-05 | 2008-06-05 | Mccoy James N | Apparatus and method of cleaning a transfer line heat exchanger tube |
| US7998281B2 (en) * | 2006-12-05 | 2011-08-16 | Exxonmobil Chemical Patents Inc. | Apparatus and method of cleaning a transfer line heat exchanger tube |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3641190A (en) | Decoking of onstream thermal cracking tubes | |
| US3617478A (en) | Suppression of coke formation in a thermal hydrocarbon cracking unit | |
| US3131142A (en) | Catalytic hydro-cracking | |
| US4883582A (en) | Vis-breaking heavy crude oils for pumpability | |
| US5358626A (en) | Method for retarding corrosion and coke formation and deposition during pyrolytic hydrocarbon procssing | |
| US5567305A (en) | Method for retarding corrosion and coke formation and deposition during pyrolytic hydrocarbon processing | |
| US3617479A (en) | Suppression of coke and heavy hydrocarbon formation in hydrocarbon units | |
| US4889614A (en) | Methods for retarding coke formation during pyrolytic hydrocarbon processing | |
| US3843744A (en) | Controlling coke in the pyrolysis of hydrocarbons to acetylene and hydrogen | |
| US3647907A (en) | Process for quenching a gas obtained by thermal cracking of hydrocarbons | |
| US5128023A (en) | Method for inhibiting coke formation and deposiiton during pyrolytic hydrocarbon processing | |
| US4420343A (en) | Process for the thermal decoking of cracked gas coolers | |
| US2617714A (en) | Process for producing carbon black | |
| US3920537A (en) | Process for on-stream decoking of vapor lines | |
| US1823503A (en) | Manufacture of unsaturated hydrocarbons | |
| US6772771B2 (en) | Decoke enhancers for transfer line exchangers | |
| JPH06228018A (en) | Method of reducing staining of and coke foamation on steam cracker | |
| US2013996A (en) | Production of acetylene | |
| RU2057784C1 (en) | Process for preparing lower olifins | |
| US4917787A (en) | Method for on-line decoking of flame cracking reactors | |
| US5221462A (en) | Methods for retarding coke formation during pyrolytic hydrocarbon processing | |
| US4384160A (en) | Prequench of cracked stream to avoid deposits in downstream heat exchangers | |
| US3338984A (en) | Process for the production of acetylene | |
| WO1997045506A1 (en) | Treating cracking tube for thermal cracking to reduce carbon monoxide and/or coke formation | |
| RU2168533C2 (en) | Method for decoking of tubular furnaces for hydrocarbon stock pyrolysis |