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
  • C10G67/00—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one process for refining in the absence of hydrogen only
  • C10G67/02—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one process for refining in the absence of hydrogen only plural serial stages only
  • C10G67/12—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one process for refining in the absence of hydrogen only plural serial stages only including oxidation as the refining step in the absence of hydrogen

Definitions

• This invention relates to a new and improved process for treating various light petroleum streams to produce certain finished products which have relatively innocuous odor properties.
• the invention is particularly usefully applied to petroleum fractions boiling in the white spirit boiling range that have been desulfurized by hydrogenation.
• a preferred catalyst comprises the combined oxides of cobalt and molybdenum supported on alumina.
• Hydrofining comprises a mild hydrogenation using a fixed bed of a suitable catli filfi l atented Oct.
• alyst such as cobalt molybdate or moybdenum on alumina or nickel-tungsten sulfide
• alyst that operates at temperatures in the range of 260-370 C.
• pressures from to 1000 p.s.i.g. with recycle hydrogen rates in the order of 200 to 100 standard cubic feet per barrel of oil charged.
• Particularly useful hydrofining conditions comprise pressure in the neighborhood of 200 p.s.i.g. at about 1 v./v./ hr. and around 3l6-343 C., using cobalt molybdate on alumina catalyst and consuming in the region of 1000 c.f./b. hydrogen.
• Heavy metals or heavy metal compounds preferably oxides or salts have been proposed as the second process phase, after the catalytic hydrogenation treatment.
• Copper or iron oxides for example, are recommended as active reagents with vaporous hydrocarbons, whereas sodium plumbite, lead acetate and copper ammonium acetate have been used in liquid phase treatments.
• a drawback of the vapor phase processes is that they have to be continuous and require very expensive equipment, so that they are hardly suitabble for smaller throughputs.
• difficulties occur in the regeneration or removal of the heavy metalcontaining waste products. Undesirable discoloration of the resultant products and storage instability is frequently encountered.
• Another process proposed for producing gasolines of the highest grade of purity with acceptable odor properties includes a combination of soda washings, hypochlorite treatment, hydrogenation and sulfuric acid refining. This process is considered technically and economically impracticable due to the extremely large amounts of chemicals required and work entailed; it does, however, clearly show the practical difliculties involved in the manufacture of odorless hydrocarbon mixtures.
• Potassium permanganate has been found to be a particularly suitable oxidant for the second process step of the invention.
• This substance has the additional advan- 3O tage that the problem of waste product removal can be technically solved in a very favorable manner.
• the spent pyrolusite-containing neutral or weakly alkaline waste water according to the invention can be readily subjected to the usual waste water purification, i.e., flocculation of 5 the oleaginous waste Water with hydroxide slurries, settlement and subsequent filtration.
• the catalytic hydrogenation step may be carried out according to 'the conventional methods described above.
• the conditions of hydrogenation are preferably selected 40 so as to obtain the most drastic possible desulfurization.
• the aqueous solutions of oxidizing salts used in the second step of the process should not be too highly concentrated as the oxidative attack on the hydrocarbon mixture would otherwise be too intense and again lead to odor deterioration.
• the optimum concentration of the salt solution depends on the nature of the hydrocarbons to be treated; it generally varies from 0.5 to 6% by weight, preferably from 1 to 3% by weight.
• Neutral aqueous solutions of the said salts or of salts with an additional content of free alkali, such as sodium hydroxide, of up to approximately 3% by weight, have been found particularly suitable. Acidified solutions are slightly inferior with respect to odor improvement.
• the quantity of salt solutions required for treatment of the hydrogenated hydrocarbon is generally in the range suitable for refining with liquid refining agents, i.e., from 0.5 to about 3% by volume, based on the quantity of hydrocarbon mixture to be treated, and preferably about 1% by volume. It has been found that smaller amounts of relatively higher concentrated solutions are more advan tageous than correspondingly larger amounts of weaker solutions; for instance, 1% by volume of 3% potassium permanganate solution yielded a product having a better, i.e., weaker, odor than 3% by volume of a 1% solution. On the Whole, therefore, surprisingly small quantities of the salt solution are used in the second step of the instant process.
• the second step of the process of the invention may be carried out batchwise or continuously.
• the duration of either type of treatment depends on the specific operating conditions required. In the treatment of separate batches in stirred containers, it is obvious that the entire contents of the container should be thoroughly mixed, approximately 1-3 hours being required, depending on the power and dimensions of the stirrer.
• the hydrogenated hydrocarbons are treat ed with an aqueous solution of the oxidizing salts of metal acids having a high oxygen content in a rotating disc contactor as described in US. Patent 2,601,674 to Reman, issued June 24, 1952. Excessively long processing periods should be avoided as they again result in odor deterioration. After settlement and separation of the spent salt solutions, the treated hydrocarbon mixture should be thoroughly rewashed.
• Step (1) Catalytic hydrogenation Step (2) Caustic soda Plumbite Hypochlorite Permanganate Chromate Hydrogen washings sweetening treatment treatment treatment treatment peroxide Ozone treatment treatment REFINING AGENTS or THE SECOND srnr F0rmula Pb(NaOz) NaClO KMDO4 K2Cl'207 H202 ()3.
• Quantity 2 x 10% by 10% by volume 0.5% by volume..-" 1% by volume- 1% by vol- 1% by vol- Up to -5 times the volume. ume. ume. theoretical oxygen requirement.
• the ozone required was prepared from dry oxygen with the aid of an ozonizer and introduced into the hydrocarbon mixture with a hit.
• the theoretical oxygen requirement; of the hydrocarbon mixture was calculated from the KMI104 consumption during titration.
• reaction conditions were: temperature, about 330 C.; pressure, about 34 atm.; molar ratio of hydrogenoil, about 1:7; space velocity, about 4 liters of liquid starting material per cu. dm. of catalyst per hour.
• reaction conditions were: temperature, about 330 C.; pressure, about 34 atm.; molar ratio of hydrogenoil, about 1:7; space velocity, about 4 liters of liquid starting material per cu. dm. of catalyst per hour.
• the treatment was effected at room tempereature.
• the treatment after the second step invariably consisted of intensive washings.
• the several treating methods were tested on several special gasolines and one test gasoline having boiling ranges of from 150-190 C. All materials responded in practically the same way to the separate treating agents so that th results of the comparative experiments listed in the table are generally characteristic of the entire range of light hydrocarbon mixtures.
• a further example of the process according to the invention is as follows: A mineral oil fraction having a boiling range of from about C. to about 200 C. was desulfurized by a catalytic oxygen treatment until the residual sulfur content was from about 2 to 7 p.p.m., with the following reaction conditions being observed: temperature, 330 C. to 360 C.; pressure, 30 to atm. gauge; molar ratio of hydrogen/ oil, 1.5-2.0; space velocity, 3 to 5 liters of liquid starting material per cu. dm. of catalyst per hour. The product was then decomposed into a broad lighter fraction, and three to four higher boiling fractions having narrower boiling ranges. These fractions were separately treated in stirred containers at normal temperatures with 1% by volume of neutral potassium permangate solution.
• the finished products obtained had a barely preceptible, mild odor which was unchanged after months of storage in tanks or even in daylight. No appreciable deterioration of the odor occured even when the products were heated at approximately C. for 48 hours.
• a process for the production of odorless or weakly odorous hydrocarbon mixtures from odoriferous hydrocarbon mixtures comprising catalytic hydrogenation of the odoriferous hydrocarbon mixtures and subsequent treatment of the hydrogenated material in the liquid phase with an aqueous solution of salts of metal acids having a high oxygen content wherein the metal is selected from the group consisting of alkali and alkaline earth metal and the anion is selected from the group consisting of permanganates, chromates and dichrornates.
• a process according to claim 1 wherein the aqueous solution has a salt content from about 0.5 to about 5% by weight.

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• 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)
• Catalysts (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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Citations (4)

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• 0
  • NL NL277643D patent/NL277643A/xx unknown
  • BE BE616852D patent/BE616852A/xx unknown
• 1961
  • 1961-04-27 DE DES73711A patent/DE1228360B/de active Pending
  • 1961-11-09 US US151176A patent/US3152070A/en not_active Expired - Lifetime
• 1962
  • 1962-04-25 GB GB15766/62A patent/GB942860A/en not_active Expired

Patent Citations (4)

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