Classifications

• • 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
  • C10G19/00—Refining hydrocarbon oils in the absence of hydrogen, by alkaline treatment
• • 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
  • C10G19/00—Refining hydrocarbon oils in the absence of hydrogen, by alkaline treatment
  • C10G19/02—Refining hydrocarbon oils in the absence of hydrogen, by alkaline treatment with aqueous alkaline solutions
• • 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
  • C10G71/00—Treatment by methods not otherwise provided for of hydrocarbon oils or fatty oils for lubricating purposes

Definitions

• the present invention relates to an improved method for refining heavy hydrocarbon oils, especially' of the type obtained from naphthenic crudes,which are susceptible to loss of color on standing or which contain impurities such as soaps having high ash contents,
• the invention will be fully understood from the following description.
• Lubricating oil distillates are frequently susceptible to loss in color on standing. This appears to be a marked characteristic of the products derived from naphthenic base crudes such as are obtained from Colombia and the Coastal regions of the United States. These oils are largely used for making low cold test lubricants for industrial purposes. The cause of the loss of color is not fully understood, but it is believed to be due to the presence of small amounts of naphthenic acids and frequently to the presence of complex phenolic materials. It is now customary to refine these oils by treatment with acid but in order to obtain color stable oils according to this method, large amounts of sulfuric acid are required in the treatment and the treating loss is quite large.
• Residual oil containing soaps and having high ash content are also troublesome to handle by present methods, which give satisfactory products only at the cost of a considerable loss of oil. It has been found that oils of these types can be readily refined Without any acid treatment whatever and they are satisfactory for most of the purposes to which they are now put. If better oils are required, a limited acid treatment or solvent extraction treatment or other refining method may be used such as limited oxidation which are followed, if desired, with either acid or solvent refining. These various refining methods are used prior to the present finishing process but'for most purposes this is not required.
• the oil whether a crude or a distillate or residue obtained by pipe still distillation or residue obtained in distillation over caustic soda, is treated under high temperature with say 10 to 500% of its volume of a dilute aqueous caustic alkali, preferably sodium hydroxide.
• the concentration of the alkali may be from .25 to 5% depending to some extent on the character of the oil to be refined, its viscosity, and the amount of impurity to be removed. It is preferred to use solutions in the more dilute portion of the range specified hereinabove, and the volume used is preferably 10 to 100% of the oil to be treated, but when the amount of the extractable materials is high, it is preferable to inrange. be such as to form a dilute solution of the extractables for example less than 10% soap so as to avoid loss of oil inthe treating solution.
• extractable materials are more soluble in and therefore more readily removable by dilute rather than more concentrated soda solutions.
• the treatment is accomplished at temperatures above about 350 and preferably below about 500 F. 1
• Residues which are solid at room temperatures may be successfully treated to remove salt, soaps, and the like.
• the temperature should be kept well up within the range specified and if allowed to fall below about 350 F., there is found to be troublesome emulsification which prevents a clean separation of the aqueous from the oily layers.
• a small amount of oil will usually be included with the aqueous layer, which is removed while hot, but great care should be exercised to remove as completely as possible all traces of the aqueous from the oily layer. If this is carefully carried out under the conditions set forth above, no further purification of the oil is required. Water washing or cooling before separation of the water and oil layers should be avoided since this causes hydrolysis of the soda compounds of the extractable materials and causes the finished oil to have high neutralization value.
• the oil distillate is freshly obtained from crude stills while it still has a good color and is immediately subjected to the treatment with the dilute caustic alkali, no further treatment is required, but it is found that the distillate goes off color rapidly on standing and to obtain a finished oil'of good color, it is often necessary to redistill the oil after the caustic treatment.
• the distillation is preferably carried out under vacuum in order to avoid decomposition. When treatingiuel oils color and color hold are unimportant but the treatment is very effective in reducing ash content which is of great importance.
• the caustic treatment is capable of removing materials which cause the oil to go off in color on standing, but once these materials have developed color, the treatment is not effective in restoring color and distillation must be resorted to.
• the treatment may be in batch or continuous,- using counterfiow or parallel flow.
• the caustic soda may be recovered mainly by cooling to room temperature whereupon the extracted material or a large part thereof settles out apd the causticmay be reused many times,
• EXAMPLE 1 A light Colombian lubricating oil distillate was heated in a closed pressure vessel with 25% of its volume of 2% aqueous caustic soda to a temperature of 400 F. A pressure of 250 pounds per square inch was maintained in the vessel so as to prevent evaporation of the causticsolution and the mixture was agitated until'tho'rough contact was assured. The mixture was then allowed to stratify, which it did cleanly, and the aqueous liquor was drawn 011 while hot. The oil was redistilled under Vacuum without any further treatment, giving 5.5% of light ends and 9 1% of a refined lubricating oil distillate.
• the average lubricating oil standard is a measure of the color stability of an average lube oil, as determined on hundreds of samples of commercial lube oils.
• an average lube oil having an initial color of 4% Robinson would have a color of 2 Robinson on heating in presence of air at 250 F. for 16 hrs., and one of 8 color would drop to 4R+ in the same test.
• the caustic treated oils are thus considerably better than the average oils.
• V1s./100 hold 16 hrs. lube oil cut Robmson at 250 F. standard Original oil 100 342 Black 2. 23 0-30 86 16% 16% 11+ 0. 05 Extracted once with 78% of 0.45% caustic at 30-50 239 10% 9% 9+ 0.08 385 F., and rerun 50-70 576 8% 8% 4% 0.09 70-90 1200 8 3% 4 0. 09 0-30 84 17 13% 11% 0. 01 Extracted once with 88% of 3.84% caustic at 30-50 243 10% 9% 8% 0.04 385 F., and rerun N 50-70 585 9% 6% 5% 0. 09 70-90 1235 8% 2% 4 0. 11
• EXAMPLE 2 A medium Colombian distillate having a Viscosity of 274 seconds Saybolt at 100 F., was extracted with 50% or its volume of dilute caustic solution at 400 F., in the same man'nerdescribed in Example 1, using a 2% caustic solution in one case and a 3% caustic solution in another case. In both cases the oil separated readily from the caustic solutions on settling at 400 F., for 5 to 10 minutes.
• the oils were redistilled under vacuum A wide cut Sugarland lube distillate having a The inspection viscosity at 100 F., of 196 seconds Saybolt was 3 extracted twice in a countercurrent tower at an average tower temperature of 385 F., using 80% of its volume of 2% aqueous caustic solution in each treat. The original oil, and the caustic treated oil, were fractionated under vacuum and 55 separated into 10% cuts.
• EXAMPLE 5 A light Colombian lube distillate was treated with 15 pounds of 91% sulfuric acid at about F. On settling, the sludge was drawn ofi and the oil was neutralized with caustic. The neutral oil so obtained which contained about 0.02% excooling the caustic extracts to room temperature or lower, practically all the extracted material separates out of solution, leaving a recovered caustic which may be used over again.
• the neutral oil so obtained which contained about 0.02% excooling the caustic extracts to room temperature or lower, practically all the extracted material separates out of solution, leaving a recovered caustic which may be used over again.
• the present invention is not to be limited to any theory of the chemical reactions involved in the treatment nor to any particular alkali.
• An improved method for refining heavy hydrocarbon oils by extraction comprising treating the oil with dilute aqueous caustic soda of up to 5% concentration under pressure high enough to maintain the hydrocarbon oil and caustic solution liquid at the operating temperature, which is above 300 F., and below the decompos ing temperature of the hydrocarbon oil, and removing the dilute caustic soda solution and exhad a color of 8 Robinson and had the charac-- tracted material from the oil while hot by decantation.
• An improved process for refining lubricating oil from naphthenic crudes which are susceptible to serious loss of color on standing consisting of the steps of bringing the oil into contact with an aqueous caustic soda solution of from .25 to about 5% while at a temperature between 350 and 500 F., under pressure sufficient to maintain the oil and caustic solution in liquid phase and separating the treating agent from the refined oil While hot by decantation.

Landscapes

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

Priority Applications (2)

Applications Claiming Priority (1)

Publications (1)

Family

ID=22784127

Family Applications (1)

Country Status (2)

Cited By (1)

• 1938
  • 1938-05-28 US US210749A patent/US2216968A/en not_active Expired - Lifetime
• 1940
  • 1940-07-15 FR FR875791D patent/FR875791A/fr not_active Expired

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