CS237656B2 - Method of tertiary amyl methyl ether production - Google Patents

Description

- 1 - 237 656

The invention relates to a method for producing a target. amyl methyl ether (TAME) from a mixture of up to Cg hydrocarbons from pyrolysis, selectively deionised and methanol. TAME is the closest homologue to methyl target. butyl ether (MTBE) and has very similar properties to the anti-knockers as an organic intermediate. Over the past 10 years, when the limits on automotive engines are becoming increasingly rigorous and pressure on oil efficiency and pressure on oil is increasing, the possibilities of reducing lead and introducing non-hydrocarbon components into gasoline are being intensively investigated. A number of recipe and technological processes for the production of a mixture of hydrocarbons and oxygen derivatives have been described. alcohols and / or ethers. Their number is constantly increasing and the procedures are being improved to avoid some negative effects on combustion in engines. In particular, the limited susceptibility, high sensitivity to changing the engine speed, reduced calorific value, are particularly exciting. for alcohols. Alternative effects of alcohols are also solved by introducing mixtures with ethers, oxides, methyl tert. butyl ether (MTBE) and, more recently, by tert-butyl methyl ether (TAME). Processes for the production of TAME, based on the Cg fraction of the cracking or steam cracking under conditions similar to MTBE, are described. on acidic ion exchangers at temperatures above normal.

It is disclosed that said fuels from fission processes optionally with water are treated with ethanol and / or methanol in the presence of acidic catalysts. Similarly, the reaction with benzine resulting from the conversion of methanol to molecular sieves is also contemplated. However, when using pyrolysis fractions, the isoprene, the cyclopentadien and the perttadienes must first be separated off. most of the fraction. Neither are the opti- mum conditions for the conversion of the methylbutenate further treatment of the product defined. The effects of diene residues on the stability of the catalysts are not described at all, although acid catalysts are known to convert diene residues to resins that stick to fixed catalysts at elevated temperatures. When examining the production of the target. ethers, particularly TAME, have been shown to have a number of disadvantages which impair their quality of yield, particularly in the production of the Cg pyrolysis gasoline fraction.

In the remainder of the TAME isolation, the resinous substances which deteriorate the resulting automobile gas are concentrated. Conventional nitrogen oxidation inhibitors deactivate acid catalysers - cation exchangers in the H-form. The motifs known for the production of MTBE match the conditions for the conversion of Cg olefins with methanol to TAME, Oine than the methyl derivatives of target. alkyl ethers rapidly form peroxides and are not storage stable; that reaction with ethyl alcohol is excluded for fuel production. Also, the equilibrium composition of the reaction mixture is unsatisfactory when higher alcohols are used.

The drawbacks of the prior art TAME are solved by a new method of manufacturing the invention. It is based on selectively hydrogenated pyrolysis benzine, which contains less than 1%, respectively. preferably below 0.5% by weight of conjugated dienes and vinylaromates.

Method of production target. The amyl methyl ether from selectively hydrogenated pyrolysis gasoline on a strongly acidic ion exchanger is characterized in that the pyrolysis gasoline containing C8 to C8 + carbon at a pressure of 3 to 5 MPa, the mixture of Cg hydrocarbons of 1 to 10% by volume C4 and 1 is isolated from the product. up to 30% by volume of the C6-fraction to which 200-200 ppm of the phenolic antioxidant is added and is passed with 10 to 30% by weight of methanol through the acid ion exchanger at temperatures of 60 to 90 ° C, preferably 70 to 80 ° C under 1 to 2 MPa with a volume velocity of 0.5 to 2.0 vol / vol / h and the product is distilled into 1, the distillate boiling to 50 to 65 ° C, to II. distillate, containing! pure TAME with boiling point of 86 ° C and the remainder, which is homogeneous oxibenzine with the distillate mission. Preferably, from 5 to 3- 237 656 to 50% of high boiling neolefinic hydrocarbons having a boiling point of 130 to 210 ° C are added in the second distillation. The temperatures for selective hydrogenation are adjusted in the above range. over time, so that the hydrogenate contains at most 1%, preferably less than 0.5% of conjugated dienes and vinylaromates. High-boiling non-olefinic hydrocarbons are concentrates of aromatic hydrocarbons, eg reformate, or also pure aromatics, eg Cg or Cg + refinery fraction. The Pd catalyst contains 0.2 to 0.4 wt. palladium on pure gamma-alumina.

The concentration range of the methanol in the invention is given in% by weight and not in the stoichiometric ratio to the reactive olefins C4 to Cg.

Thus, two alternatives can be chosen, a stoichiometric ratio that limits the amount of alcohol in the product and the overstoichiometric ratio improving conversion and yield of TAME. The addition of a phenolic antioxidant has a beneficial effect on the stability of kaolin. Higher aromatics then reduce distillation residue problems during distillation. in the case of low C 8 hydrocarbons in the crude and thus low in the target. Cg methyl ethers in the residue. In addition, the solubility of the remaining methanol in the hydrocarbons is improved. The method of the invention and its effect is documented in the following example. Example

Pyrolysis gasoline containing C8 to C8 + hydrocarbons was hydrogenated on a Pd catalyst with 0.3 wt. Pd on alumina at 85 ° C, under a pressure of 4.2 MPa hydrogen per product containing diolefins and vinyl aromatics below 1%. From the product, a light fraction containing 2 wt. % C 3 hydrocarbons, 3 wt. The C8 hydrocarbons and the remaining hydrocarbons were C8 hydrocarbons, with 28% by weight of methylbutene * la, and various concentrations of acetonitrile were added to this light fraction in a series of experiments, the temperature at one concentration of methanol was changed and the effect of volume velocity was observed. . Stabilityionex was also assessed depending on the addition of the antioxidant (amount and species).

The reaction products were distilled at atmospheric pressure on a 4 - 237 656 column of about 10 TP with the addition of 20% by volume of heavy reformate boiling at 135 to 205 ° C. TAME concentrations in the reaction product were assessed and optimal parameters were found. The results of the experiments were as follows: 1st series - temperature influence: 14% by weight addition methanol (m.p. CgH10: CH3OH 1: 2) and LHSV 1.0 h reached a maximum at 75 [deg.] C. with 20-22% by weight. TAME. At temperatures of 60 to 70 ° C and 80 to 100 ° C, the TAME content decreased to 15 to 10% by weight.

2nd series - volume velocity influence: at mol. the 1: 2a ratio of 75 ° C -1 was not within 0.5 to 2.0 h the difference in isoamylene conversion to TAME. 3rd Series - Effect of Moths the ratio: when reducing the molar ratio from 1: 2 to 1: 1.1, the TAME content was reduced to 12 to 10% by weight. 4th Series - Addition of Antioxidant: The phenolic antioxidant prolonged the ion exchanger stability of 2 to 3 times the antioxidant counterpart in the range of 50 to 200 ppm. 50 ppm of the nitrogenous antioxidant caused a complete cessation of the reaction already 1/10 of the antioxidant-free running time. 5th Series - Effect of Selective Hydrogenation Level: Upon increasing the content ofudiolefins to 2%, the resin content of the reaction product increased five times and the cation exchange stability decreased to one third. From the above production survey, the final complete piece was performed:

The Cg fraction from pyrolysis gasoline after selective hydrogenation of the above conditions with the above-mentioned quality was mixed with 1.1 moles of methanol per mole of reactive isoamylenes, i.e. with 14% by weight of methanol. 50 ppm of the phenolic antioxidant φ-tert-butylphenol was added thereto, and the mixture was passed at 75 ° C, 1.5 MPa and 1.0 volume / volume hour over the acid ion exchanger. 80% unreacted Cgfraction and methanol to 55 ° C were distilled off from the product on a 10-tier column, 10% aromatics Cg + - 5 - 237 656 from the reformate were added to the residue with a boiling point of 135 to 205 ° C and from the same column 18% wt. 99% TAME at 86 ° C at atmospheric pressure and to the remainder passed 2% higher proportions, which were diverted by the diluted Cg + aromatics to further processing eg for gasoline.

The TAME distilled product had a mixed OCM of 112 to 114 without oil and 120 to 125 with 0.5 g of Pb / 1 (as TEO). The mixture of light and heavy fractions had no lead in OCV 95 and was stable even when mixed with benzine. Two phases did not form as when mixing methanol with a C 5 fraction. In the present process with a Cg fraction without hydrogenation, only a third of the TAME yield was obtained and the light and heavy fraction (oxibenzine) had a high resin content (above 200 mg / 100 ml).

Claims (3)

SUBJECT MATTER 237 856 A process for the production of target, amylmethylether (TAME) from selectively hydrogenated pyrolysis gasoline and methanol on a strongly acidic ion exchanger, characterized in that the pyrolysis gasoline containing C 8 to C 8 + hydrocarbons is selectively hydrogenated at 30 to 210 ° C under pressure 3 to 5 MPa, a mixture of C 8 hydrocarbons and 1 to 10% and 1 to 30% v / v of the fraction is isolated from the product, to which 20 to 200 ppm of a phenolic antioxidant is added and passed with 10 to 30 wt. methanol over an acidic ion exchanger at temperatures of 60 to 90 ° C, preferably 70 to 80 ° C and under a pressure of 1 to 2 MPa with a volumetric velocity of 0.5 to 2.0 v / v / h and the product is distilled by a two-stage inlet of 5 to 50% higher boiling non-olefinic hydrocarbons with a boiling point between 130 and 210 ° C, preferably aromatic hydrocarbon concentrates, eg reformate, or pure aromatics, eg Οθ or CG + from refinery processes, to I. distillate with boiling point of 50 to 65 ° C to II. distillate containing pure TAME with a boiling point of 86 ° C and a residue which is mixed with the distillate to homogeneous oxibenzine. 2. The process of claim 1 wherein the selective hydrogenation temperature is adjusted over a period of time such that the hydrogenate consistently contains at most 1% by weight, preferably less than 0.5%, of conjugated dienes and vinylaromates. 3. The process of claim 1 wherein the catalyst comprises from about 0.2% to about 0.4%. palladium on pure gamma-alumina. Printed by Moravian Printing Works, Price: 2,40 Kčs operation 12, tř.Lidových milicí 3, Olomouc