JPH068414B2 - Method for producing liquid vaporizer fuel for gasoline engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a main stream which undergoes a purification treatment and a subsequent reforming treatment by distillation of a coal naphtha fraction obtained by coal liquefaction, a phenol and various To a secondary stream enriched in alkylphenols, optionally further after isolation, the secondary stream containing more enriched phenol is reacted with a methylating agent for a liquid vaporizer fuel for gasoline engines.

[Conventional technology]

During the treatment of cracked or refined hydrogenations of coal or lignite or the hydrogenation of coal extracts, coal oils containing varying amounts of phenols and various phenols, especially alkylphenols, are produced. Although phenol and its alkylated derivatives are excellent anti-noxious agents for carburetor fuels, they have strong corrosive effects and are physiologically dangerous, so they cannot be used as octane improvers.

In general, coal oil is a catalyst refining stage (refining) using gaseous hydrogen
Is processed into liquid vaporizer fuel. In this stage, decomposition of phenol contained in coal oil into naphthenes and decomposition of hetero compounds containing nitrogen and sulfur into hydrocarbons are carried out, and heteroatoms O, N and S are decomposed into simple hydrocarbons. . This decomposition takes place without difficulty under suitable conditions. During the subsequent reforming, among other things, aromatization of naphthenes and aromatics from linear paraffins are also carried out, with some of the hydrogen produced in the reforming stage supplying the hydrogen demand produced in the refining stage and other conversion processes. To help. The high phenol content of crude coal oil results in a high content of naphthenes, especially cyclohexane, during refining. Such a method of making gasoline engine fuels results in undesirably high benzene content as the reforming process increases the benzene content in coal gasoline.

Of course it has a different purpose than the method according to the invention,
The following strategies have been proposed in U.S. Pat. No. 4319981 to separate the phenols. That is, the phenol-containing fraction of coal oil is separated, the phenol and its alkylated derivatives are converted into a mixture of methylallyl ethers, which mixture is added back to the refined and reformed coal gasoline. A basic paper by GM Singaman Gulf Research and Development Company has shown that the mixture of methyl aryl ethers thus obtained is suitable as a fuel additive and an octane number improver (CA95: 153).
300j).

Addition of 5% by volume of this methylallyl ether mixture increases the octane number (ROZ) according to the research method by 0.6, for example.

The transition from a phenol mixture to an ether mixture is carried out according to said U.S. patent with dimethylsulfate, extraction with aqueous sodium hydroxide, washing of the extract, removal of the detergent, reacidification and addition of sodium chloride, liberation. Washing the phase containing phenol to separate the phenol,
Addition of aqueous sodium hydroxide and dimethyl sulphate to the isolated and clarified phenol mixture, addition of excess aqueous sodium hydroxide to hydrolyze unreacted excess dimethyl sulphate to remove unetherified phenol , Separation of the methylallyl ether phase, washing of the reaction product by distillation and processing.

Isolation and etherification of the resulting phenol is time consuming and material consuming.

[Problems to be solved by the invention]

The object of the present invention is therefore to avoid, in a process of the type mentioned at the outset, the costly isolation of phenolic compounds from coal oil.

[Means for Solving the Problems] In order to solve this problem, according to the present invention, the secondary stream is dimethyl carbonate as a methylating agent, and dimethyl carbonate as a methylating agent under a methylation condition. At least a portion of the secondary stream thus obtained, containing the anisole and various methylallyl ethers, which has been treated without the addition of a catalyst, to remove the by-products methanol and carbon dioxide which subsequently form. Join at least part of the mainstream receiving.

It is also proposed to add dialkyl carbonate, preferably dimethyl carbonate and diethyl carbonate, to leaded or unleaded gasoline as fuel for internal combustion engines. By this addition, the gasoline anti-knock property is improved (European Patent Publication No. 82688).

It has been found that the desired etherification product can be obtained in a simple one-step synthesis by reacting coal oil or a fraction of coal oil with dimethyl carbonate at a temperature of about 150 to 180 ° C., if possible. The reaction can be carried out continuously in an autoclave or in a reactor integrated into the overall equipment for producing gasoline fuel from coal oil.

As a reaction product, a mixture of etherified phenol and methanol is produced according to the following reaction formula.

The carbon dioxide produced as a by-product when carrying out the process according to the invention can be discharged without difficulty. Subsequent treatment of the reaction mixture of the reaction of the phenol-containing fraction with dimethyl carbonate may be carried out at 65 ° C. in the pre-distillate so as to separate the methanol which is also formed as a by-product.

The dimethyl carbonate used in the process according to the invention employs large-scale products of the chemical industry provided by various manufacturers. Dimethyl carbonate is synthesized, for example, according to the following formula.

2CH ₃ OH + CO + 1 / 2O ₂ − (H ₃ CO) ₂ CO + H ₂ O Further, according to the present invention, methanol obtained as a by-product remains in the secondary stream that undergoes methylation by dimethyl carbonate. Be done. The secondary stream obtained by the process and comprising anisole and various methylallyl ethers and optionally methanol is particularly suitable as an intermediate component for petroleum refinery gasoline.

Orthomethylation of phenols with dimethyl carbonate is known and the reactions described in the literature are carried out in the presence of a catalyst such as a tertiary amine, tertiary phosphine or a mixture of sodium hydroxide and potassium iodide.

It was surprisingly found that the reaction of the fraction of coal oil rich in phenols and alkylated derivatives of phenols with dimethyl carbonate does not require an additional catalyst which must be removed again in the subsequent treatment.

The process according to the invention significantly reduces the burden of refining and reforming steps and saves considerable hydrogen.

Since the reaction in the process according to the invention is carried out in high yields of ether, the separation of unmethylated phenol can be omitted when the product is used as an intermediate component.

〔Example〕

 The method according to the invention is further illustrated by the following example.

Example 1 150 to 220 by fractional distillation from coal oil of coal liquefaction facility operated as an experimental facility in Boat Trop.
A fraction boiling at 0 ° C was isolated. The following components were found from the gas chromatographic (GC) analysis for phenol.

Phenols 8.84% by weight Orthocresol 3.94% by weight Metacresol 2.86% by weight Paracresol 8.02% by weight 200 g of this coal oil fraction was heated to 160 ° C. in a stirred autoclave with 72 g of dimethyl carbonate. The pressure rose to 19 bar within 4.5 hours. After cooling, the autoclave was depressurized via a gas meter. This process was repeated twice. Overall 13.8 gas was produced (99.6 vol% CO ₂ , gas density at 20 ° C. 1.842 g /). Weighed 242 g of liquid product and 25.3 g of gaseous product. The reaction product still contained 1.7% by weight of phenolic material. This was added to the reformed cut without subsequent treatment. The gasoline content of this vaporizer fuel was 3.6% by weight.

Example 2 From coal oil of the same origin as in Example 1, a fraction boiling below a temperature of 150 ° C was separated.

2,127 g of a coal oil fraction in the boiling range of 150 to 220 ° C. and 319 g of dimethyl carbonate were covered with nitrogen in an autoclave and then heated to 185 ° C. with stirring. Within 10 hours the pressure rose to 40 bar and subsequently dropped to 16 bar after cooling to 25 ° C. The autoclave was depressurized via a gas meter and had a gas density of 1.832 g / 98.6% CO 2 at 20 ° C.
91 gases, including ₂ , were produced.

The liquid product weighed 2,311 g.

GC analysis results 95.6% by weight phenol to anisole 75.8% by weight orthocresol to orthocresyl methyl ether 83.8% by weight metacresol to metacresyl methyl ether 97.0% by weight paracresol to paracresyl methyl ether I knew it was converted to.

Example 3 The test results of three fractions of etherified coal oil obtained by the method according to the invention are as follows.

Boiling point fraction A 150 to 215 ° C Fraction B 150 to 185 ° C Fraction C 185 to 215 ° C 10% by volume of the above fraction is mixed with a commercially available leaded special grade fuel (SVK) and the following mixed octane number is obtained. was gotten.

MOZ is the octane number by the motor method.

A mixture of 60% by volume of special grade fuel and 40% by volume of pyrolysis total gasoline showed an oxidation resistance value according to DIN 51600 of 260 minutes.

By mixing 10% by volume of the respective cuts A to C into the abovementioned 60:40 mixture, the oxidation resistance was increased in all cases to values of 960 minutes and above.

The following values of evaporation residue were determined for the three fractions A to C in 10% by volume mixing with commercial grade fuel (DIN 51 according to DIN EN 5 600 maximum evaporation residue of 5 mg / 100 ml).

All fractions A, B and C were brandy in color, A brighter than C and B brighter than A. The cut had the following densities:

The 10 volume% mixture of d _{15 (g} / ml) fraction A 0.927 fraction B 0.920 fraction C 0.934 grade fuel, turbidity up to -25 ° C. is has failed occur.

Claims (2)

[Claims] 1. A coal naphtha fraction obtained by coal liquefaction is divided by distillation into a main stream which undergoes a purification treatment and a subsequent reforming treatment and a secondary stream rich in phenol and various alkylphenols. According to the method, after the isolation, a secondary stream containing a large amount of phenol is reacted with a methylating agent, and the secondary stream is treated with dimethyl carbonate as a methylating agent without adding a catalyst under methylation conditions. At least a portion of the resulting secondary stream comprising anisole and various methylallyl ethers is removed from at least the main stream which has been subjected to the subsequent treatment step. A method for producing a liquid vaporizer fuel for a gasoline engine, which is characterized by joining with a part. 2. A process according to claim 1, characterized in that the secondary stream undergoing methylation with dimethyl carbonate leaves behind methanol which is produced as a by-product.