CS267972B1 - Method of mono- and diolefins' common removal from sulphur - Google Patents

Abstract

Hydrogenation of BTX-containing fraction monoolefins and eiric compounds contaminated diolefins including woollaromates a indanes on a Co-Ni-Mo-sulfide catalyst, Whose activity and stability was increased combination of cobalt and nickel and two ways to introduce active metals. The process removes both olefins and sulfur at temperatures of 20 to 50 ° C lower than Other catalyst types used, whose active ingredients have been introduced into Catalyst One in Standard two combinations.

Description

The invention relates to a process for the co-removal of mono and diolefins from sulfur aromatic concentrates obtained by pyrolysis of liquid hydrocarbons, the process being carried out under pressure and at elevated temperatures in the presence of a trimetallic low-temperature metal-containing catalyst containing metal sulphides VI. and VIII. groups of the periodic table with high activity and stability given by the composition and adjustment of the introduction of components on the carrier, active alumina. The hydrogenation product is suitable for the production of pure aromatic hydrocarbons zvi. C ₆ to Cg, extraction and redistillation with reduced consumption of percolation cleaning clay.

In addition to catalytic reformate, the main sources of benzene, fluorine and xylenes are liquids. 540 ° C. In addition to aromatics, pyrolysis produces unsaturated hydrocarbons, on the one hand with ε one or more double bonds, and on the other hand, acetylenic structures as well as vinyl aromaticates, in particular styrene and homologues. Although cold hydrogenation in the liquid phase on Pd or l catalysts is effective, in addition to unreacted monoolofins, some of the diolsfins, vinylaremates or intrinses remain unhydrogenated in the product. nonoclcfins. Reactive holes, vinyl arorates and indanes readily pass upon heating to condensates of a highly carbonic structure approaching biscuit. Under conventional hydrogenation conditions for non-bisulfide catalysts, coke is formed rapidly, catalyst activity decreases, temperatures increase, and coke formation accelerates. The catalyst must be regenerated, which brings a loss of the unit's time fund, the quality of the produced aromatics and non-automatic raffinates, in which olefins are concentrated, deteriorates.

A process has been developed for the co-removal of mono and diolefins from sulfur aromatic concentrates obtained by pyrolysis of liquid hydrocarbons and subsequent selective cold hydrogenation, under hydrogen pressure at elevated temperatures, in catalysts containing metal sulfides VIL and VIII. groups of the periodic table consisting according to the invention in the form of aromatic endings. Wastes boiling in the range of 60 to 160 ° C containing up to 5 wt.%, diolefins and up to 25 wt. 2.5 to 4.0 MPa and a volume rate of 0.5 to 2.0 hours in the presence of hydrogen gas containing 60 to 90% by volume of hydrogen in addition to saturated hydrocarbons, in a volume ratio to liquid hydrocarbons of 100 to 1000: 1 per a trimetallic catalyst containing sulphides of molybdenum, nickel and cobalt on a garaa-alumina in a total concentration of 15 to 25 wt. 2.5, of which 25 to 75% are applied to the carrier by saturation with an aqueous solution of a metal salt. The hydrogenation takes place in two to three successive stages, the volumes of which are in the ratio i to 2: 1 or 1 to 2: 1: 1 to 1, and the inlet temperatures are gradually increasing by 5 to 70 ° C. The sc catalyst is preferably prepared in such a way that the part of the metal salts supplied by the saturation preferably forms salts of one of the pairs of said metals, in particular molybdenum and nickel. Sulfides of molybdenum, nickel and cobalt are formed by heating metal oxides on active gamma alumina in the presence of hydrogen and hydrogen sulphide from 20 to 150 ° C to 320 to 400 ° C with delays in the range of ICO to 150 ° C, 200 to 250 ° C and at 320 to 350 ° C until the penetration of hydrogen sulfide through the catalytic bed.

The analysis of the new process reveals the main new features, the most significant of which is the use of a trimetallic catalyst in the form of metal sulphides, which are incorporated on an active support in two ways. This achieves a bifunctional catalyst causing desulfurization and hydrogenation of olefins, with high activity limiting the formation of coke from diolefins at low inlet temperatures. The new process converts a sulfur aromatic concentrate with olefins and dienes into a practically completely saturated sulfur-free product, at lower temperatures with a higher volume rate and possibly also with a lower ratio of hydrogen to hydrocarbons. The low reaction temperature prolongs the operating cycles as well as the overall life of the catalyst.

In the example below, this is illustrated by model conditions.

CS 267 972 Bl

Example

In the 1st experiment, 100 ml of the catalyst designated A and in the 2nd experiment were charged with the same amount of the catalyst designated B in the same grain size, the composition given in the table, including the method of adding the components, to the quarterly pressure hydrogenation apparatus ae.

Sulfurization of the catalyst was performed by heating and circulating gas containing about 1 volume in hydrogen with four hour delays at 120 ° C, 220 ° C and 350 ° C until a breakdown of H _o s behind the reactor. Catalyst Λ was further heated to 410 ° C according to the manufacturer's recommendations, where a time delay of 4 hours was also observed.

The DTX fraction from pyrolysis gasoline with a boiling point of 70-155 ° C was used for the experiment, Dr. 16.4 g Or / 100 g and a diene number of 3.1 g O2 / ¹⁰⁰ Ο · Β ”Χ fraction further had 213 ppm S.

Under the following constant conditions, the effect of temperatures on desulfurization and hydrogenation of unsaturated compounds was tested.

Conditions: pressure 3.0 flPa throughput 1 and 2 h ¹ gas circulation - 500 volumes / volume BTX; H 2 content> -98% v / v) temperature 275 to 375 ° C

Table 1

Composition of the tested catalysts

Catalyst AND P Characteristics ordinary according to the invention composition „mass. i'oC- 12 5 13 »2 CoO 3.5 2.1 KiC · 0 2.1 Delivery Method just coprecipitation according to the invention * metals

+ 63 metals in the preparator by saturating the annealed intermediate molybdenum salting intermediate ÍVÁ) c nickel (ZT).

Table 2 compares the levels of hydrogenation DT, on the fraction on both catalysts, of the method standardly used and according to the invention.

It follows from this that the process of the invention shows better results at lower temperatures and at higher volumetric velocities. Reducing the temperature also guarantees an extension of the process periods and the life of the catalyst.

Similarly, ss compared other catalysts in which it was. eg only Γϋ and Co or were partially saturated with Co - Ho. None of them reached catalyst activity Π.

Catalyst A would. ¹ , also used in the operating unit with a capacity of about 150 kt / ra and was replaced by a catalyst □. 20 ° C at the same level of removal of dienes, monoolefins and sulfur. Dylo can increase the catalyst volume load by IC and reduce gas circulation by 20 to 30.

CO 257 07- Pl

Table 2

Hycrogonaco OT ;; fractions on catalysts A and β

Catalyst D Reaction temperature c 325 375 300 325 375 Enforcement h ¹ 1 - 1 O 1 1 2 1 2 Product: - 3 ppm 3r .č.gSr / lOOml dien.číslo SJo / 100 ml and About MM 1 * »* 1 M ON 1 6.7 3.1 o.l 1.0 0.5 0.1 3.2 4.1 0.1 0.5 0.1 0.1 1 1 0 00 1 * * * 1 M (! T? 1 0.5 0.07 0.1 0.6 0.2 0.1 and 0 00 1 * * * 1 M M U 1 M 1 0.5 0.37 0.1

OBJECT OF THE INVENTION

Claims (2)

OBJECT OF THE INVENTION A process for the co-removal of mono- and diolefins from sulfur aromatic concentrates obtained by pyrolysis of liquid hydrocarbons and subsequent selective cold hydrogenation, under hydrogen pressure at elevated temperatures on catalysts containing metal sulphides VI. and VIII. groups of the Periodic Table on a carrier, characterized in that the aromatic concentrates are boiling in the range from 60 to 160 ° C containing up to 5% by weight, diolefins and up to 25% by weight. ronoolefinO in addition to benzene, toluene and C 4 aromatics, containing up to 1 000 ppm sulfur compounds, are reported at a temperature of 220 to 340 ° C under a pressure of 2.5 to 4.0 MPa and a volume rate of 0.5 to 2.0 h ¹ per the presence of hydrogen gas containing 60 to 93 volumes of hydrogen in addition to up to C4 saturated hydrocarbons, in a volume ratio to liquid hydrocarbons of 100 to 1000: 1 per trimetallic catalyst containing molybdenum, nickel β cobalt sulfides on active gamma-alumina in a total concentration of 15 to 25% wt., wherein the weight ratio of the precursor oxides of MoO ₃ : CoO is 18: 1 to 4: 1 to 4, preferably 14: 2.5: 2.5, of which 25 to 75 are applied to the support by saturating with an aqueous solution of metal salts. 2. The process according to claim 1, characterized in that the hydrogenation takes place in two to three successive stages, the volumes of which are in the ratio 1 to 2: 1 or 1 to 2: 1: 1 to 2 and the inlet temperatures are 5 to 70 ⁰ C gradually ascending.