petrochemical process nptel, separation of petroleum

petroleum and petrochemical products, petrochemical process nptel,installation, and service of petroleum equipment and convenience store,

Nederlandse V, Raffinadery Van Petroleumproducten Sparndamseweg N

methanol extraction tower

This invention pertains to the refining of blended hydrocarbons, particularly petroleum hydrocarbons. Extra significantly, it pertains to the refining of petroleum hydrocarbons or fractions of petroleum hydrocarbons containing, in addition to different hydrocarbon compounds undesirable constituents similar to natural sulfur compounds (e.g. mercaptans, alkyl sulfides and disulfides, sulfoxides, sulfones and thiophene and its homologs), unsaturated hydrocarbon compounds, nitrogen compounds and oxygenated compounds, by therapy of said hydrocarbons with boron trifluoride and water.

Processes for treating petroleum hydrocarbons with boron trifluoride, boron fluoride hydrate and with certain boron trifluoride complexes are identified and disclosed, for instance, in U.S. Pat. Nos. 2,257,627; 2,416,465; 2,495,851; 2,691,622; 2,745,792; and 2,767,one hundred twenty. These processes are usually based upon the extraction of hydrocarbons with BF three complexes, the polymerization of unsaturates which stay in solution and might be eliminated by distillation of the BF 3 -handled hydrocarbon, or the formation of partially soluble sludges of nonhydrocarbons impurities by treating with BF three which are then extracted with suitable solvents. In the case of heavy stocks or previously unrefined stocks it has been discovered that extraction with boron fluoride doesn’t readily afford complete part separation of the impurities from the refined hydrocarbon.

In accordance with the present invention, it has been found that hydrocarbon stocks could also be advantageously refined by admixing a small portion of a member chosen from the group consisting of water and boron trifluoride monohydrate with stated hydrocarbon stocks and then treating mentioned admixture with gaseous boron trifluoride thereby forming an insoluble precipitate of the undesirable impurities within the hydrocarbon stocks that can be readily separated from the refined inventory. It’s an essential feature of the current invention that the amount of gaseous boron trifluoride used is in excess of that stoichiometrically necessary for advanced formation with the water.

The process according to the present invention may be carried out on crude petroleum hydrocarbon distillates, upon fractions produced therefrom by distillation, upon crude petroleum stocks and synthetic mixtures of petroleum fractions, on partly refined hydrocarbons or different untreated or handled hydrocarbons on byproducts obtained from the refining or dewaxing of petroleum fractions, or stocks obtained by cracking hydrocarbons and on coal tar and coal tar distillates. This list of merchandise is illustrative only and other hydrocarbon stocks could also be successfully handled in accordance with the present invention.

In training the process of the current invention small proportions of water is first totally admixed with the hydrocarbon stock and gaseous boron trifluoride is then added to the admixture. Between about 0.1 p.c to about 5 % by weight and ideally between about zero.5 p.c and 1.5 % by weight of water based on the hydrocarbon inventory is admixed with the hydrocarbon stocks. Boron trifluoride monohydrate can be appropriate to be used, preferably in quantities ranging between about 1.5 % and 4 % by weight primarily based on the hydrocarbon inventory.

The amount of gaseous BF 3 employed may range within large limits relying on the kind of hydrocarbon inventory to be refined and the content material of undesirable constituents to be removed. It is crucial when water is employed that the quantity of gaseous boron trifluoride used is higher petrochemical process nptel petrochemical process nptel than stoichiometrically vital for advanced formation with mentioned water, an excess of between about 10 % and 50 % by weight of gaseous BF3 being advantageously employed. An amount of gaseous BF three ranging between about 2 percent and 5 p.c by weight based on the hydrocarbon stock has been advantageously employed in combination with boron trifluoride monohydrate-hydrocarbon admixtures.

The means of the current invention could also be carried out over a wide range of temperatures and pressures. Temperatures of from about 0° to 150° C. have been found handy for finishing up the refining process, while temperatures falling throughout the vary of 60° to 120° C. are especially appropriate and most popular. The method could also be carried out at atmospheric strain, however greater pressures speed up the refining procedure and are usually preferred.

The remedy in accordance with the means of the current invention removes sure parts by formation of compounds that are incompatible with the refined hydrocarbons, as for example, by polymerization, advanced formation, formation of extremely polar compounds, coagulation of asphaltic compounds, and so forth. After the remedy two phases are formed, one part consisting of the refined hydrocarbons and a second which is composed of the incompatible compounds, that could be readily separated from each other by gravity settling or other identified strategies. It is a vital feature of the present invention that the undesirable constituents are removed from the handled hydrocarbon by precipitation, a comparatively simple and inexpensive approach, reasonably than by extraction or distillation.

The refined oil part will contain solely a really small percentage of boron trifluoride that may be easily eliminated by distillation beneath a slight vacuum. The oil can then be used as a completed petroleum oil as such or might be subjected to a ending treatment, as for example, therapy with activated clay or sulfuric acid, hydrogenation or any other finishing treatment. The end result shall be an improved product with considerably improved colour, improved stability and with a lowered content of undesirable constituents.

The precipitated section will contain most of the boron trifluoride along with the incompatible undesirable impurities and it is possible to recuperate the boron trifluoride from the precipitate by distillation at appropriate temperatures with or without the appliance of a vacuum.

It has been discovered that significantly advantageous technique for recovering BF 3 from the precipitate is by way of a falling movie evaporator to perform the distillation recovery procedure. In this method the precipitated part flows in the type of a thin film down alongside a tube heated to between 250° and 300° C. and the BF three is readily recovered. The recovered BF three is suitable for reuse within the refining process, enabling the method to be carried out continuously utilizing recycled BF 3. The precipitate could also be repeatedly provided to the movie evaporator and recovered BF 3 and sludge residue continuously taken off.

The strategy of the present invention can be utilized to petroleum distillates to enhance the quality of heavy fuel oil and mild spindle oil and similar merchandise originating from the atmospheric distillation of crude petroleum, but is also valuable for refining vacuum distillates used for lubricating oils and for particular purposes equivalent to for transformer and electrical oils. It’s also very effective for the refining of residual products.

The following examples are illustrative of the practices of the present invention but are not to be considered as limitative of its scope. Percentages said are by weight.

Example 1
a reaction vessel, provided with stirring equipment, was crammed with 500 grams of an unrefined cylinder oil (see specification in table I, column 1).

The oil was heated to a temperature of 90° C. and 3 grams (0.6 % by weight) of water have been added with agitation.

Gaseous boron trifluoride was launched into the admixture of cylinder oil and water maintained at a temperature of about 90° C. till 15.5 grams had been absorbed. The petrochemical process nptel reaction mixture was then allowed to separate into an upper layer of refined oil and a lower layer consisting of compounds which have been immiscible with the higher layer. After decanting, an higher layer weighing 455 grams and containing 0.12 grams BF 3 was obtained. The immiscible lower layer had a weight of sixty three.Three grams.

The refined oil phase was heated to 200° C. underneath a vacuum of 30 mm. Hg vacuum so as to separate the dissolved BF 3. Thereafter the refined oil was neutralized with lime and treated during half-hour with 5 percent of activated clay at a temperature of 120° C. The refined oil fraction thereby obtained has the properties as set out in column 2 of desk I under.

The separated immiscible precipitate layer was distilled employing a falling movie evaporator at a temperature of 250°-300° C. and atmospheric strain. The BF 3 present on this part was substantially completely recovered and collected for reuse. ————————————————————————— Desk I

Column 1 Column 2 __________________________________________________________________________ Cylinder Oil Cylinder Oil Untreated BF 3 handled Spec. Gravity 20/4° C. Zero.944 zero.936 Visc. centistokes 140° F. 459 303 Visc. centistokes 200° F. Sixty four.1 52 Viscosity Index 0 25 % Sulfur 0.33 zero.19 % Fundamental Nitrogen zero.092 zero.003 Color ASTM D1500 dil. Eight four Color after heating throughout 24 hrs. at 120° C. dil. 8 5.5 __________________________________________________________________________

From the aforementioned figures it is obvious that the therapy as described yields an oil with considerably improved characteristics, with a yield earlier than clay remedy of over ninety p.c. A traditional refining method applied to the identical cylinder oil, consisting of solvent refining with a selective solvent adopted by acid therapy with sulfuric acid, neutralizing and clay therapy, will give a yield of about 70 % refined oil, but with a coloration of solely 5.5/6 ASTM.

Example 2
3 grams of H2 O have been added with agitation to 500 grams of a partly refined vivid inventory oil (see specification in table II, column 1) in the response vessel described in example I. The admixture was heated to a temperature of 90° C. and BF three was added until 20 grams have been absorbed.

The immiscible products were separated by centrifugation and a refined oil part of 377 grams was obtained, which contained zero.4 grams BF three.

The dissolved BF three was removed from the refined oil in the identical means as described in example I, and the oil was then handled with 5 % activated clay during 30 mins. at 120° C.

A substantial decrease in the sulfur content was found and also the basic nitrogen content material was much decrease than was present in the unique materials (see table II, column 2). The ultimate product has an improved color stability.

During storage at 120° C. for 48 hours, the colour modified from 1.5 (ASTM D1,500) to 2.5 (ASTM D1,500). ————————————————————————— Desk II

Column 1 Column 2 __________________________________________________________________________ Spec. Gravity 20/4° C. 0.890 0.880 Visc. centistokes 140° F. 103.Four 90 Visc. centistokes 200° F. 30.Three 27 Primary Nitrogen % zero.012 zero.001 % Sulfur 1.28 0.6 Coloration ASTM D1500 6 1.5 Shade after aging forty eight hours at 120° C. dil. 8 2.5 __________________________________________________________________________

Example 3
1.5 grams H 2 O had been added with agitation to 750 grams of a gentle spindle distillate (see specification in column 1, table III) at a temperature of 60° C. in the same approach as described in instance I.

BF 3 gasoline was added to the heated admixture till 21 grams of BF 3 were absorbed. The immiscible part was separated by gravity settling and 735 grams of a refined oil had been obtained, which contained 0.37 grams of BF three. The BF3 was separated from this oil fraction by distillation as described in instance 1.

The oil was then neutralized by washing with lime and handled with 2 % activated clay for 30 mins. at 120° C.

The specification of the oil thereby obtained is acknowledged in desk III, column 2. The original product (desk III, column 1) was handled with 5 p.c activated clay, to compare the outcome with the BF three handled oil.

Both oils were then saved at temperatures of 120° C. for 96 hrs. After storage the oil not treated with BF 3 had a color of 4.5 ASTM D1500, while the oil handled with BF 3 had a shade of 1.5 ASTM D1500. ————————————————————————— Table III

Column 1 Column 2 __________________________________________________________________________ Untreated Oil BF three-water treated oil Spec. Gravity 20/4° C. Zero.895 zero.889 Visc. centistokes 100° F. 12.2 eleven.Eight Visc. centistokes 200° F. 3.0 2.95 Coloration ASTM D1500 2.0 1.5 Color Lovibond 2″ cell. 0.5 (Yellow series) __________________________________________________________________________

Instance four
500 grams of a selected gentle lubricating oil extract obtained from furfural extraction of a lubricating oil inventory to which zero.63 p.c by weight of water was added, was agitated for about three hours at 80° C. During this time gaseous BF three was passed via the agitated extract. At the tip of the treatment 5.3 weight percent of BF three fuel was absorbed. After settling two layers were obtained. The refined oil product and a pattern of the starting furfuraL extract have been clay handled with 6 % by weight of an activated clay. The outcomes of the therapy are listed under: ##SPC1##

Example 5
boron trifluoride monohydrate was admixed with a cylinder oil raffinate having a specific gravity at 20° C. of zero.936, an NPA (National Petroleum Affiliation) coloration of eight and a viscosity of 664 centistokes at 50° C. and stated admixture was treated with BF three gas within the proportions of elements described within the table beneath. Colour properties of the treated hydrocarbon is summarized in the accompanying table. Different samples of the above described cylinder oil have been separately three with BF 3 gas and BF 3 H 2 O and the comparative results are summarized beneath. When the oil was handled with BF 3 gasoline only no coloration enchancment was noted. Refining with the mix of three p.c BF three H 2 O and a couple of % BF 3 gasoline resulted in color properties comparable with 10 p.c BF three H 2 O refining, indicating apparent financial benefits. The entire refining procedure of this example had been carried out at 80° C. ##SPC2##

An NPA coloration of eight corresponds to a deep crimson shade; NPA colours in the vary of 4 to 2 correspond to orange pale, four, to extra pale, 2. See W. L. Nelson, Petroleum Refinery Engineering, 4th Ed. (New York: McGraw-Hill Guide Firm, Inc. 1948), Chapter 3 for a comparison of commonly used petroleum colour scales.