DE1279873B - Process for the stabilization of catalytically cracked motor gasoline containing thiophenols and phenols - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

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German class: 23 b -1/05

P 12 79 873.1-44 (U 7640)

December 9, 1960

October 10, 1968

Many mineral spirits contain thiophenols and phenols in relatively high, sometimes the same concentration. Thiophenols impair the stability of the mineral oil and lead to resinous residues. A mixture of 75% diisobutylene and 25 ° / ₀ butadiene has an ASTM resin residue of 1. Substituting enough p-thiocresol to, up to a copper number of 27, it shows, after contact with air an ASTM resin residue of 34. The Thiophenols have a particularly pronounced effect, as another mixture of diisobutylene and butadiene with the addition of n-heptyl mercaptan (copper number 29) only shows a resin residue of 3 after contact with air.

The thiophenols can be extracted from mineral spirits by extraction with sodium or potassium hydroxide solution removed, which requires large amounts. Large amounts of sodium phenolate and sodium thiophenolate solutions fall in the process at.

Certain phenols, such as trialkylphenols, prevent the formation of resin residues in fuels, other phenols are harmful in fuel. So you have to remove the latter from the fuel, the former in it. This selective phenol removal is the object of the process according to the invention.

It is known that phthalocyanine catalysts for the regeneration of used alkali metal hydroxide solutions to use to oxidize them. In doing so, however, the catalysts are used in the form of hydrocarbons separated aqueous alkali metal hydroxide solution used.

According to an older proposal, the distillate is converted into an alkali hydroxide solution of mercaptans in the essentially freed, the sulfur compounds are present in the separated alkali metal hydroxide solution a phthalocyanine catalyst is oxidized to disulfides with an oxygen-containing gas. After their Separation, part of the regenerated alkali hydroxide solution is returned to the extraction zone, adds fresh phthalocyanine catalyst to another part of the regeneration liquor and brings this liquor in contact with the partially treated distillate in the presence of air. The two-stage treatment of the hydrocarbon distillate consists in the first stage only in an alkaline extraction, while in the second stage an oxidation takes place in the presence of a phthalocyanine catalyst.

According to another proposal, acidic hydrocarbon distillates are also sweetened by them with oxidizing agents, e.g. B. oxygen, in the presence of an alkaline reagent and a phthalocyanine catalyst has treated. However, this takes place

Method of stabilizing catalytically
krakem, thiophenols and phenols
containing petrol

Applicant:

Universal Oil Products Company,

Des Piaines, JIl. (V. St. A.)

Representative:

Dr. H.-H. Willrath, patent attorney,

6200 Wiesbaden, Hildastr. 18th

Named as inventor:

Kenneth Michael Brown, Hinsdale, JH. (V. St. A.)

Claimed priority:
V. St. v. America 10 December 1959
(858 593)

only a reduction in mercaptan sulfur, and the alkaline reagent used can contain phenol or cresol as a dissolution promoter.

In contrast to this, the purpose of the process according to the invention is to stabilize mineral spirits, containing thiophenols and phenols to obtain a thiophenol-free fuel in the the polyalkylphenols, such as trialkylphenols, are still included. Unwanted phenols, about 60% of the all phenolic compounds in the starting gasoline are removed from it.

To achieve this object, the method according to the invention is based on the last-mentioned method for sweetening acidic hydrocarbon distillates, with catalytically cracked, thiophenols and phenol-containing free oxygen motor gasoline in the presence of a phthalocyanine catalyst and aqueous alkali hydroxide solution is treated. The method is characterized in that the treatment with an aqueous Alkali hydroxide solution made of a density below 1.21 g / ml, essentially thiophenol-free Gasoline separated from the alkali hydroxide solution and this with an aqueous alkali

809 620/335

Hydroxide solution with a density of more than 1.21 g / ml is necessary in exceptional cases. The reaction can be

is extracted. In this way 'between 10 pressure or overpressure of. 0.7 to 68 at or more

and 90 percent by weight of that contained in gasoline drain.

Phenols removed. . From the _; Gap withdrawn from the first stage - In a preferred embodiment of the petrol, about] 10 to are removed by extraction

Driving is based on a motor gasoline, 90%> preferably 30 to 70%, - of the phenols / die-im

in which the thiophenol oxidation with fuel, desirable polyalkylphenols are difficult

using an aqueous sodium hydroxide solution to extract riger and remain in the fuel, a density of 1.02 to 1.16 g / ml, "and these solutions of lithium hydroxide, rubidium hydroxide

Gasoline is used with aqueous sodium hydroxide solution and cesium hydroxide is generally used for

extracted to a density of 1.26 to 1.52 g / ml. not used for this purpose.

Thiophenols include thiocresols, thioxylenols, and the extraction of the phenols can be carried out in batches

especially thiophenol, methylthiophenol, dimethyl or continuously. Air is in this

thiophenol, ethylthiophenol, diethylthiophenol, Pro- second stage of the process not used. Gepylthiophenol and dipropylthiophenol. If desired, the decision can be made from the second stage of the

Common gasoline can also contain mercaptans and alkali hydroxide solution drawn off in the process

contain other sulfur compounds that are used to di- first.

sulfides are oxidized. In the process of the invention, the fuel is always more stable and the thiophenols can be oxidized to diphenyl disulfides resin formation inhibitors, but also with those in ao that remain dissolved in the fuel and are sold in reduced amounts without an additional first stage. ^; second stage cannot be removed. Diphenyl disulfide In the first stage one oxidizes with air, oxygen does not affect the stability of the fuel, or other oxygen-containing gases. Copper and plumbit sweetening processes are used in the cobalt phthalocyanine, oil phase, and form thioether hydroperoxides, vanadium phthalocyanine, iron and copper as that remain in the fuel and its instability bephthalocyanine. Metal phthalocyanines are active in aqueous. Thiophenols oxidize in air to form solvents which are sparingly soluble. Therefore they are in peroxides and affect the stability, aqueous alkali hydroxide solution or on solid carriers. -I ₁ liked to use it. The sulfonated derivative example is preferred, ζ. B. cobalt phthalocyanine sulfonate. It is available commercially at 30 The catalytic cracking gasoline (b.p. 46 to 230 ⁰ C, and consists of cobalt phthalo- - density at 15.6 ° C 0.7555 g / ml, 0.08 percent by weight cyanine disulphonate and cobalt phthalocyanine monosul- phenols and 0 .04 percent by weight thiophenols) had fonat. Another preferred catalyst consists of a resin residue according to ASTM D 381 »Existant of vanadium phthalocyanine sulfonate. gum hi fuels by jet evaporation «of 25 mg / 100 ml. The phthalocyanine catalyst is treated in aqueous 35 159 m ^{3 of} gasoline with 7 m ^{3 of} air and an alkaline cobalt solution, preferably in aqueous sodium phthalocyanine disulfonate catalyst, which is in trium or potassium hydroxide solution or sometimes 16 m ³ aqueous sodium hydroxide solution of a density was also dissolved in solutions of ammonium hydroxide, lithium Cd ₄ ) of 1.16 g / ml (15% NaOH) at 38 ° C. hydroxyd, rubidium hydroxide and / or cesium- The used aqueous sodium hydroxide solution used with hydroxyd. The phthalocyanine catalyst 40-50 parts by weight of catalyst per million by weight can also be used on solid supports, such as bone charcoal, parts NaOH originally also contained 15% by weight charcoal, charcoal made from coconut or other nut percent NaOH and came from petrol peelings or from fruit kernels. During which they had absorbed 15 to 20 percent by volume of phenols. Other carriers are coke, carbon-Raschig. After use, the rings, silica, alumina and silica-clay-45 aqueous sodium hydroxide solution from gasoline were earthed compositions. disconnects and re-used within the system. With the alkaline solution, the gasoline is intimately. The fuel obtained in this way was essentially freely mixed, e.g. B. by nozzle mixer or equal to thiophenols, but contained about 0.05 weight or countercurrent flow in the reaction zone, the percent phenols. The evaluation according to the ASTM fractionation trays or bells and / or carbon resin method resulted in a value of about 7. Contains substance-Raschig rings. The fuel obtained in the first stage of the process and the alkaline catalyst solution are mixed and gasoline is separated in a second stage with 16 m ^{3 of} water by settling. The alkaline catalyst solution sodium hydroxide solution with a density of 1.45 g / ml is reused in the process and is saturated _{with phenolic compounds (42 ° / 0} NaOH) treated at ambient temperature. After reuse and then separated from the sodium hydroxide solution, the lye is saturated with phenols. The fuel now contained less than 0.01 weight percent from this stage of the process, contains phenols and is phenolics and had an ASTM Resin Formation Value substantially free of thiophenols and others less than 3.

Mercaptans. In the method according to the invention none occur

The phthalocyanine catalyst is based on a solid 60 large volumes of used alkali hydroxide solution

Carriers placed in the reaction zone are soaked up with thiophenolates. The volume ratio

Fuel and air or oxygen in cocurrent sodium hydroxide solution to gasoline was in the

or passed over the contact in countercurrent, first and second treatment stages about 0.1. if

after which the fuel is separated from the alkaline solution but, as mentioned, the one separated from the gasoline

is separated. The oxidation of the catalytic fission 65 sodium hydroxide solution again within the system

Gasoline is generally used at room temperature, for example a continuous

or higher, for example at 93 ⁰ C, carried out. To treat fresh gasoline stream for more than 1 hour,

higher temperatures up to about 204 ⁰ C are only in this way this ratio still decreases. If for example

ί 279

if the same amount of sodium hydroxide solution was used for 500 hours, the total fresh ^{gasoline flow would be 795,000 m 3} and the ratio of sodium hydroxide solution to total gasoline would then be reduced to 0.00002.

Example 2

The cobalt phthalocyanine sulfonate on activated charcoal catalyst used was in the prepared as follows: A cobalt phthalocyanine sulfonate solution in water was prepared, which contained a trace of ammonium hydroxide (28%), and this solution was activated with stirring Given carbon granules. The mixture was left to stand overnight and then the excess Filtered off water. The catalyst was dried and adjusted to be 1 percent by weight Contained phthalocyanine.

On the used gap petroleum (bp. 40-232 ⁰ C, density at 15.6 ° C 0.7535 g / ml, phenol content 0.07 weight percent, Thiophenolgehalt ao 0.003 percent by weight, ASTM backing resin dance 15.3 mg / 100 ml) were 16 m ³ and 500 l of air per hour passed down through a fixed bed of the catalyst described. The reaction was ^{carried out at 41 °} C. under 6.8 at. 2 m ^{3 of} aqueous sodium hydroxide solution with a density of 1.03 g / ml (3.3% NaOH) were mixed with the gasoline and air and passed through the catalyst bed. After the reaction, the sodium hydroxide solution and gasoline were separated and continuously returned to the system.

The gasoline separated from the sodium hydroxide solution contained 0.04 percent by weight phenols and was essentially free of thiophenols. The fuel was then washed with an aqueous sodium hydroxide solution of 1.36 g / ml (33% NaOH) at ambient temperature alternately in two separate treatment zones extracted with sodium hydroxide solution. The gasoline was first made with fresh sodium hydroxide solution treated until this was saturated in phenols, after which the gasoline flow into the second Zone was transferred while the sodium hydroxide solution of the first zone was replaced with fresh one became.

The treated gasoline from the second stage of the process was more stable and had an ASTM resin formation value below 3. Furthermore, the sodium hydroxide solution used was free of thiophenols and can therefore be used for chemical purposes after separation.

Example 3

10 m ^{3 of} catalytic cracking gasoline were mixed per hour with oxygen, and the mixture was ^{brought into contact with 2 m 3 of} a circulating aqueous sodium hydroxide solution having a density of 1.075 g / ml (7% NaOH) with 1% by weight of vanadium phthalocyanine carboxylate on charcoal . It was ^{oxidized at 52 °} C. and 13.6 at. The effluent was separated into an upper fuel layer and a lower sodium hydroxide layer in a settling vessel, and the latter was returned to the system for further use.

The gasoline withdrawn from the settler then became an upflow countercurrent to an effluent Sodium hydroxide stream of 1.45 g / ml passed through a treatment vessel with a bubble cap. the Sodium hydroxide solution was reused until saturated with phenolic compounds. Then it was replaced with a fresh solution of 1.45 g / ml (42% NaOH). That dealt with, from the Gasoline separated from sodium hydroxide solution was essentially free of thiophenols and was more stable.

Claims (1)

Claim: Process for stabilizing catalytically cracked containing thiophenols and phenols Motor gasoline by treatment with free oxygen in the presence of a phthalocyanine catalyst and an aqueous alkali metal hydroxide solution, characterized in that the treatment with an aqueous Alkali hydroxide solution made of a density below 1.21 g / ml, essentially thiophenol-free Gasoline separated from the alkali hydroxide solution and this with an aqueous alkali hydroxide solution having a density of more than 1.21 g / ml is extracted. Considered publications:
German Patent No. 832,312;
U.S. Patent No. 2,853,432; Legacy Patents Considered:
German patents No. 1 084 861, 1102 951. 809 620/335 9.68 G Bundesdruckerei Berlin