US2085759A - Process of improving bloom material - Google Patents

Description

Patented July 6, 1937 PROCESS OF IMPROVING: BLOOM MATE- RIAL Lycurgus Laskaris, Lansdowne, Pa., assignor to The Atlantic Refining Company, Philadelphia, Pa., a corporation of Pennsylvania No Drawing. Application August 3, 1934,

' Serial No. 738,210

4 Claims. (Cl. 196-1) The present invention relates to a process for improving the bloom impartingqualities of high molecular weight hydrocarbon mixtures containing green fluorescent compounds, which hydrocarbon mixtures are capable of imparting desirable fluorescence or bloom to hydrocarbon oils when added thereto in relatively small quantities and to the incorporation of such improved material in hydrocarbon oils deficient" in green 'fluo- 10 rescence.

More particularly, this invention is concerned with the improvement of bloom imparting agents such as those derivable from coal tar and petro leum hydrocarbons, for'example, coal tar pitch .15 and petroleum pitch, extracts of the same, or the high boiling distillates of coal tar or petroleum.

It has been known, heretofore, to employ residues or heavy distillates of coal tar and/or petroleum for the purpose of imparting green fluo- 20 rescence and other desirable qualities to hydrocarbon oils, particularly petroleum lubricating oils. However, in accordance with the practice of the prior processes for blooming oils, for example, the imparting of green fluorescence to lubricating 5 oils by contacting the same with coal tar pitch, it has been found that the stability of the oils with respect to bloom is not entirely satisfactory, especially at elevated temperatures or over extended periods of storage atnormal tempera- 3o tures. Lubricating oils which have been bloomed by commingling with coal tar pitch show a. decided tendency to deposit carbonaceous material or flocs when raised to and maintained at temperatures somewhat higher than normal atmos- 35 pheric temperatures or when held in storage for extended periods at atmospheric temperature. Furthermore, simultaneously with the deposition of flocs, the intensity andshade of the green fluorescence is impaired and the oil becomes 49 darker in color.

r I have found that bloom-imparting agents, particularly those derived from coal tar, for example, coal tar pitch, may be improved to substantial extent by heat treatment at tempera- 45 tures above the melting point thereof,-and may 1 absence of reagents effects a substantial improvement in the bloom agents, I prefer to effect such heat treatment in the presence of one or more of the reagents above mentioned.

In accordance with my invention, high molecular weight hydrocarbon mixtures containing 5 green fluorescent compounds, particularly'hydrocarbon mixtures derived from coal tar; are treated to produce improved bloom agents, which when added to hydrocarbon oils, give, in comparison to untreated coal tar derivatives, (1) an improved shade of green fluorescence, (2) substantially less color darkening of the oil per unit of bloom increment, (3) a much improved stability to heat and to extended periods of storage,

Briefly, my preferred method of operation comprises heating a bloom agent, for example, coal tar pitch of 200 F. to 500 F. melting point, to a temperature of from about 400 F. to about 800: F.-, and more preferably to a temperature within the range of from about 600 F. to 700 F. During the period of heating, the pitch may be agitated and a suitable quantity of reagent, for example, sodium hydroxide, may be added to the pitch undergoing the fusion or heat treatment. The quantity of reagent employed is generally of the order of 0.1% to 2% by weight. However, depending upon the character of the bloom agent being treated, the quantity of reagent'necessary to effect the desired result during the fusion may be as muchas 5% or more by weight. The fusion period, in the presence of the added reagent, is usually of-the order of 15 to 30 minutes, at the preferred temperature of from 600 F. to I00" F., but such fusion period may be longer or shorter, depending upon the character of the bloom agent being treated, the type of reagent employed and the fusion temperature. After the fusion has been effected, the treated pitch may be cooled to atmospheric or lower temperature and'then reduced to a powder by pulverizing, or further 4,0

treated to effect a concentration of the green fluorescent bodies contained in the fused pitch.

I have found that during the treatment at elevated temperatures in the presence of a reagent such as, for example, sodium hydroxide, substantial chemical reaction between the reagent and the bloom agent occurs. A considerable quantity of 'thesodiurn hydroxide combines chemically with constituents of the bloom agent and a substantial improvement in the quality of the bloomagents is effected. If desired, any unreacted sodium hydroxide maybe leached from the treated bloom agent by water or other solvent either atelevated temperatures or after the treated bloom agent has been cooled and pulverized,

but in view of the small amount of free alkali contained therein such leaching is unnecessary when the treated bloom agent is to be employed for imparting green fluorescence to lubricating oils.

My process may be employed to particular advantage in the treatment of bloom agents derived from coal tar, including coal tar pitch and bloom concentrate obtained from such pitch. For example, a pitch may be extracted with a solvent and the concentrated bloom extract, after removal of the solvent, may be heat treated in the pres ence of my alkaline reagent. Or, a coal tar pitch may be extracted at elevated temperatures with an aromatic solvent, the insoluble pitch residue separated from the solution, the solution then diluted with a precipitating agent such as paraffin naphtha whereby the desired bloom compounds are precipitated from solution, and the precipitate freed of diluent liquid and heat treated in the presence of a reagent such as sodium hydroxide, lime or sodium carbonate.

To assist further in an understanding of this invention, there are described herein specific examples of the application thereof, with the understanding that this invention is not limited thereto.

Example I 400 lbs. of 360 F. melting point coal tar pitch was charged to a gas fired mixing vessel and heated, with agitation, to a temperature of about 650 F. The time required for bringing the pitch to this temperature was approximately 3 hours. After this temperature had been attained, about 2 lbs. of dry sodium hydroxide by weight) was added with constant agitation and the tem perature of the mixture was increased to about 700 F. over a period of from 15 to 30 minutes. Upon the completion of the fusion period, the contents of the mixing vessel was cooled to 600 F. and the product was withdrawn, cooled to normal temperature and pulverized, and was then ready for use as an improved bloom agent.

Example II A comminuted coal tar pitch was charged at the rate of 150 lbs. per hour and dry sodium hydroxide was charged at the rate of lb. per hour to a continuously heated mixing vessel having a capacity of about 200 lbs. of material, the contents of said vessel being continuously agitated at a temperature of about 600 F. The rate of withdrawal of the fused bloom agent was adjusted to permit an average period of fusion of about 80 minutes, the treated product being continuously withdrawn, cooled and pulverized. The resulting powdered bloom agent was then ready for use in blooming hydrocarbon oils.

The improved bloom agents may be employed for imparting desirable green fluorescence to oils by merely commingling the agent with the oil and separating that portion which does not go in solution or suspension in the oil, or by extracting the fused bloom agent with solvents and adding the bloom extract, in the presence or absence of solvent, to the hydrocarbon oil. Or, the fused bloom agent may be extracted with heavy hydrocarbon oil to form a concentrate which may be blended with oil of poor bloom, in any desired proportion. Finally, the fused bloom agent may be admixed with fullers earth or other decolorizing medium and the oil then percolated through or contacted with such admixture. For example,

a distillate from a Mid-Continent crude oil, having a Saybolt universal viscosity at 210 F. of 120 seconds and an A. S. T. M. color of 5% was contacted with untreated coal tar pitch to give a green bloom of a definite intensity. The bloomed oil resulting from such contacting had an A. S. T. M. color of 7%, whereas the original oil stock, when contacted with coal tar pitch fused with /g% by weight of sodium hydroxide, to give exactly the same degree of bloom intensity, had an A. S. T. M. color of 7. Thus, for two oils having the same degree of bloom intensity, the employment of the fused pitch effected less darkening of the oilstock by approximately of an A. S. T. M. color unit.

The same oil stock, when contacted with a coal tar pitch which had been heat treated at -about 700 F. for a period of about 15 minutes, in the absence of my alkaline reagent, had a bloom of the same intensity as above mentioned and an A. S. T. M. color of 7 A; to 7 /2.v While I prefer to carry on my heat treatment of bloom agents in the presence of an alkaline reagent, it will be seen that in accordance with my invention a substantial improvement may be effected by heat treatment in the absence of such reagent.

Furthermore, While I have described my process in connection with the improvement of coal tar pitch blooming agents, I may apply my treatment to coal tar and petroleum derivatives containing bloom materials capable of imparting a desirable green fluorescence to hydrocarbon oils, for example, coal tar residues and heavy distillates, cracked or uncracked petroleum residues and similar materials. Also, I contemplate as within the scope of my invention, heat treatment in the presence of reagents, applied either prior or subsequent to any purification or concentration process employed in connection with bloom agents derived from coal tar and petroleum. For example, coal tar pitch may be heat treated according to my process and thereafter extracted with a solvent to form an improved bloom concentrate, or coal tar pitch may be extracted with a solvent and such extract, after removal of the solvent, may be fused with one or more of my reagents to form an improved bloom agent.

For brevity, in the appended claims the term alkaline reagent is to be understood to comprehend the monoxides, hydroxides and carbonates of the alkali and alkaline earth metals or mixtures of such compounds.

What I claim is:

1. The process of improving the bloom-imparting qualities of coal tar pitch capable of imparting green fluorescence to hydrocarbon oils when added thereto, which comprises heating said pitch to a temperature of from 400 F. to 800 F., for a period of from about 15 to 80 minutes in intimate contact with a reagent from the group consisting of the oxides, hydroxides and carbonates of the alkali and alkaline earth metals.

2. The process of improving the bloom-imparting qualities of coal tar pitchcapable of imparting green fluorescence to hydrocarbon oils when added thereto, which comprises heating said pitch to a temperature of from 600 F. to 700 F., in intimate contact with a compound from the groupconsisting of the alkali and alkaline earth hydroxides.

3. The process of improving the bloom-imparting qualities of coal tar pitch capable of imparting green fluorescence to hydrocarbon oils when added thereto, which comprises heating said pitch to a. temperature of from 600 F. to 700 intimate contact with sodium hydroxide, cooling F., in intimate contact with about 0.1% to about and comminuting the heat treated pitch, con- 5% by weight of sodium hydroxide. tacting said comminuted pitch with ahydro- 4. The process of imparting green fluorescence carbon oil and separating therefrom the porto a hydrocarbon oil, which comprises heating tion of said pitch insoluble therein.

coal tar pitch containing green fluorescent bodies.

to a temperature of from 600 F.'to 700 F. in LYCURGUS'LASKARIS.