Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • C10L1/00—Liquid carbonaceous fuels
  • C10L1/10—Liquid carbonaceous fuels containing additives
  • C10L1/14—Organic compounds
  • C10L1/28—Organic compounds containing silicon
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10B—DESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
  • C10B43/00—Preventing or removing incrustations
  • C10B43/14—Preventing incrustations
• • 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

Definitions

• the furnaces employed for heating the petroleum are tube furnaces in which the petroleum passes through a series of tubes, which tubes are heated to temperatures of 500 to 1000 F. At this temperature the petroleum cracks, but is maintained in liquid form by the high temperature and high pressures employed. The liquid product then passes out of the tube furnace into a second stage where it may be either allowed to solidify as in the case of coke preparation, or it may be burned as in the preparation of carbon black, or the liquid may be put through some other process.
• the deposition of coke in the tube reduces the rate of flow of the petroleum, thereby subjecting it to the extremely high temperatures for longer than the desired time. This tends to increase the rate of deposition of the coke and thereby complicated the problem.
• the deposition of coke introduced a hazard due to the weakening of the tube walls.
• the siloxane can be introduced into the petroleum at any time prior to passage through the furnace. Furthermore, the siloxane can be mixed with the petroleum in any convenient manner.
• the preferred method is to dilute the silxone with an inert solvent, such as a hydrocarbon solvent. In general, the preferred concentration is from one part siloxane to 30 parts solvent to one part silxone per 50 parts solvent.
• the siloxane is introduced continuously into the petroleum, however, the rate of introduction need not be constant. In other words, during the initial part of an operation one may introduce the siloXane at the rate of parts per million based on the weight of the petroleum while during the latter part of an operation one may reduce the siloxane to 3 parts per million.
• methylsiloxane which is in fluid form can be employed in this invention.
• the term in fluid form means that the siloxane can be either a fluid per se at room temperature or it has been rendered fluid by the introduction of a solvent.
• methylsiloxane includes those polysiloxanes in which all of the hydrocarbon substituents on the silicon are methyl radicals and it also includes those siloxanes in which some of the substituents are methyl radicals, whereas the other substituents are hydrogen, or hydrocarbon radicals such as ethyl, phenyl, B-phenylpropyl, fl-phenylethyl, or vinyl.
• the physical structure of the siloxane is immaterial so long as it is in fluid form.
• the viscosity of the siloxane can range from less than one cs. to non-flowing gums.
• the siloxane has terminal organic groups or terminal hydroxyl groups or whether it is linear, cyclic or branched in molecular configuration.
• Example 1 This example illustrates the utility of the method of this invention to prevent coke buildup in a coking furnace employing petroleum residium.
• the petroleum residium was passed through a pipe line into a coking furnace where it was heated to a temperature of 900 F.
• the molten residium was then passed through a second line into a cooling tank where the coke was allowed to solidify.
• a dimethylpolysiloxane of 12,500 cs. was introduced into the petroleum residium prior to passage through the cracking furnace at a rate of 10 parts per million.
• the siloxane was introduced continuously by dissolving it in kerosene to a concentration of one part of siloxane to 50 parts kersene and then pumping the solution into the petroleum line at a suificient rate to give the desired concentration of siloxane in the petroleum residium.
• the furnace operated for 8 months without any shutdown due to the deposition of coke in the tubes.
• the furnace had to be shutdown at least about every three months for the cleaning or replacement of the tubes.
• Example 2 Equivalent results are obtained when petroleum is passed through a vaporizer furnace and heated at a temperature of 900 F. and the effluent gases thereafter burned to form carbon black.
• Example 3 Equivalent results are obtained when the following siloxanes are employed in the process of Example 1:
• a method of extending the furnace life in petroleum furnaces by preventing, or decreasing coke accumulation in the furnace which comprises mixing with the petroleum prior to heating in the furnace from .1 to 100 parts per million of a polyrnethylsiloxane in fluid form, based on the weight of the petroleum.
• silox-ane is a polydimethylsiloxane.
• a method of extending the furnace life of petroleum tube furnaces by preventing or decreasing coke accumulation in the furnace which comprises mixing with the petroleum prior to heating in the furnace from .1 to 100 parts per million of a polymethylsiloxane in fluid form, based on the weight of the petroleum.

Landscapes

• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
• Silicon Polymers (AREA)

Priority Applications (5)

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Publications (1)

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Cited By (7)

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Citations (2)

• 0
  • NL NL277655D patent/NL277655A/xx unknown
  • NL NL120318D patent/NL120318C/xx active
• 1961
  • 1961-07-17 US US124353A patent/US3170865A/en not_active Expired - Lifetime
• 1962
  • 1962-07-03 GB GB25468/62A patent/GB958098A/en not_active Expired
  • 1962-07-05 DE DED39317A patent/DE1188235B/de active Pending

Patent Citations (2)

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