DE3041174A1 - Prodn. of 1-6 carbon hydrocarbon - using zeolite MCH catalyst - Google Patents

Abstract

hydrocarbon is produced by reacting a hydrocarbon contg. 2 or more C atoms and/or a hydrocarbon deriv. contg. H-C links over a catalyst comprising zeolite MCH (as described in GB2061900). Process is esp. selective to oaking of molecules with small dia. (e.g. de-oaking of hydrocarbons by oaking alkones and leaving a prod. enriched in aromatics, esp. polynuclears, such as may be used as a tube oil base stock.) Other uses of the catalyst include prodn. of olefins from methanol and/or dimethyl ether; upgrading of oxide feed and/or waste streams contg. S and N cpds; etc. The Ca-H exchanged form is esp. selective for producing ethylene and propylene.

Description

Process for the production of hydrocarbon

materials The invention relates to a method for the production of Hydrocarbons in particular by cracking higher hydrocarbons or by reacting low molecular weight compounds in the presence of a zeolite MCH as a catalyst.

Reactions that lead to hydrocarbon products and where as a catalyst, a zeolite of the large-pore type such as X or Y or a zeolite medium pore size, such as a zeolite of the ZSM-5 family, are known. The latter reactions, whether they are from hydrocarbons with relatively long i Chains to be split or of hydrocarbons and their derivatives with single carbon atoms or candle chains with, for example, up to 4 carbon atoms, which are to be polymerized, go out, generally lead to the formation of aromatic hydrocarbons, unless special measures such as conversion with low throughput or the use of modified catalysts will.

According to the invention it has now surprisingly been found that the conversion of the above-mentioned raw materials into hydrocarbons of 6 or less Carbon atoms catalyzed by the recently discovered zeolite MCH can be.

The subject of the invention is that characterized in claim 1 Procedure.

The zeolite VCH typically has the chemical composition 1.0 + 0.2 R2O Al2O3. 4 to 7 Si02. 0 to 8 H2O, where R is a monovalent cation or 1 / n of a cation of valence n. The characteristic X-ray diffraction pattern of zeolite MCH is similar to that of Herschelite, but all lines are due the small crystallite size widened. The (2 @) peaks of the characteristic Lines have a half width at the diffraction angles shown in Table I. of more than 1 °.

Table I 2M (°) d (nm) Intensity [(I / Io) x 100] 9.3 0.95 33 16.3 0.54 12 20.9 0.425 66 27.5 * 0.324 23 30.5 * 0.293 100 34.0 * 0.264 13 * These lines were incompletely resolved.

Values in the range are more typical for the half width of the (2N) peaks from 1.50 to 3.50. These half widths correspond to a crystallite size of less than 20 and especially less than 10 nm units.

Preferred forms of the MCH zeolite are further characterized by that they exchange at least 25% of their sodium ions with magnesium ions and substantially all of their sodium ions with ammonium or rare earth ions are capable.

The zeolite MtH is further characterized in that it is in the Sodium form has a sorption capacity of at least 1.5% by weight n-hexane and 1% by weight Has p-xylene, whereby these values refer to the measurement at 25 ° C and half the saturation vapor pressure relate.

The MIJH zeolite and its preparation are in the UK patent application 79/38047 (Whittam) described in more detail. The one to be used in the process according to the invention Zeolite NCH should have sufficient purity to allow it to be of the desired degree is catalytically active. The zeolite MCH is suitably in the form of a material used, which has been synthesized under conditions that for the simultaneous Formation of typically up to 30% by weight and especially 5 to 20% by weight of gmelinite to lead.

So that the zeolite MCH (hereinafter referred to as "MCH") in one preferred extent is suitable for use in the method according to the invention, becomes the form in which it was produced by hydrothermal synthesis and in which it contains alkali metal oxide, converted into an active form by ion exchange.

MCH has a content for use in the method according to the invention of alkali metal compounds of preferably less than 3 and in particular less than 2% by weight, these values being calculated as Na 2 O equivalents. Even at at an alkali content of 0.5% by weight or more, suitable activity is observed. MCH is preferably prior to the start of the reaction by heating in air or in activated an oxygen-free gas to 400 to 600 C; such treatment is also suitable for reactivating the used catalyst. The water content of the freshly activated or reactivated catalyst in the above-mentioned The formula for the chemical composition is preferably 0 to 2 mol.

In the active form, the alkali metal ions are at least measured; partially has been exchanged for hydrogen or for polyvalent metal ions. The exchange by hydrogen can be brought about by contacting with an acid or with Ammonium ions or the ions of a non-quaternary amine, as such Ions decompose during calcination, leaving hydrogen ions behind. For the polyvalent metal ions, a metal is preferably selected in relation to has little or no catalytic activity on hydrogenation, the The exception is that the synthesis is to accompany a conversion, as follows is described. Suitable metals are metals of group II or of the rare earth metal group of the Periodic Table as set out in Abridgments of Specifications, published dated British Patent Office. Vl) are preferably both hydrogen ions as well as polyvalent metal ions are present. Calcium Hydrogen MCH appears for the production of ethylene and propylene to be particularly selective.

MCH can be used in full or as a mixture: with a diluent such as inert silica, alumina or clay can be used, with a suitable proportion of the diluent is between 10 and 40% by weight. The diluent can shape bodies such as cylinders or spheres with a size from 1 to 10 mm for use in a fixed bed or of fine particles for use facilitate in a fluidized bed of MCH, and the diluent also enables a regulation of the rates of the desired and undesired conversions, which run off over the catalyst. The diluent can, if desired, be a zeolite; a suitable combination consists of a mixture of MCH with a zeolite such as gmelinite, which is combined with a suitable choice of conditions is synthesized with MCH.

The feed item can be one under normal conditions, for example gaseous hydrocarbon (containing up to 4 carbon atoms) or a mixture such hydrocarbons as LPG or an easily vaporizable hydrocarbon or a mixture of such hydrocarbons (with 5 to 12 carbon atoms) as liquefied natural gas or naphtha or higher, easily vaporizable hydrocarbons like kerosene or gas oil. If the feed is a hydrocarbon derivative is suitably a hydrocarbon derivative in which an at least some of its carbon atoms bonded to at least two hydrogen atoms are. Oxidized hydrocarbons such as alcohols, ethers, carboxylic acids, esters, aldehydes and ketones and their acetals are very suitable starting materials.

A particularly suitable application of the method according to the invention consists in the production of olefins from methanol and / or dimethyl ether, since MCH, in contrast to, for example, the ZSM-5 family of zeolites, for the Production of gaseous hydrocarbons under normal conditions and against the production of aromatic hydrocarbons appears to be selective.

By the method according to the invention, raw starting material and / or waste gas or waste streams containing organic sulfur or nitrogen compounds are upgraded to useful products.

There may be unwanted Hydrocarbon derivatives and possibly also unconverted feedstock belong. The crude product is obtained by condensing the contained therein, under normal conditions liquid compounds are separated, and the gaseous fraction is by distillative Fractionation or separated by adsorption. Unwanted and not implemented Materials can be used after obtaining the desired products and separating them other products such as methane, carbon oxides, water and (if appropriate is) hydrogen subjected to further conversion stages via MCH or for another Conversion can be returned to the main feed in the cycle.

The reaction temperature is suitably in the range of 300 to 450 ° C and especially from 350 to 400 ° C when the olefin product has 4 to 6 carbon atoms should contain; however, it is suitably in the range of 400 to 550 OC and especially from 425 to 525 OC when ethylene and / or propylene are the main products meant to be.

The pressure at which the method according to the invention is carried out, is suitably in the range from 1 to 51 bar abs., in particular in the range from 1 to 15 bar absolute, but higher pressures, for example up to 304 bar abs., if the is appropriate, for example when a methanol synthesis or a similar synthesis with the invention Procedure is combined.

The space velocity should be regulated to make the desired one Product distribution is achieved.

For example, in the case of using methanol as the feed material an hourly liquid reaction - space velocity of about 1.0 to a higher Ar, part of dimethyl ether than an hourly space velocity of 0.2. The dimethyl ether can be recycled or in a separate one Bed of MCH or another catalyst are implemented. Apparently it is Conversion of the methanol is preferably incomplete and is, for example, in Range from 75 to 98%.

The catalyst retains its activity for a considerable period of time at; however, it can be regenerated by keeping it under the conditions that for its activation are preferably applied, heated. Preferably will the catalyst used in the form of a fluidized bed from which the catalyst is continuous withdrawn, passed through a regeneration zone and to the olefin formation reaction is returned.

The method according to the invention can be used in combination with a method for the synthesis of hydrocarbons and / or oxidized hydrocarbons catalytic conversion of carbon oxides with hydrogen can be used. The synthesis products can be separated via MCH before the reaction, but can the MCH catalyst, if so desired, arranged or inserted in the manner that he ts before any product separation step: on the synthesis products a- works, for example in a downstream of the synthesis catalyst bed or by using a mixture of separate pieces the synthesis catalyst and the MCH catalyst or through the use of separate Pieces that have been made are immersed in a mixture of powdered MCH and synthesis catalysts, or by incorporating one or more metal compounds or oxides having such synthetic activity by impregnation or ion exchange on MCH. Suitable synthesis catalysts contain, for example, one or more representatives of the copper, zinc oxide, chromium oxide and the base metals or noble metals of group VIII of the periodic table. The pressure the implementation via MCH can be chosen so that it meets the conditions of the synthesis reaction is adapted.

As example 2 shows, MCH is for cracking hydrocarbons relatively inactive with a large "CSA" diameter. (The CSA diameter is it is the width of the molecule in the plane in which the molecule has a minimum Cross-sectional area.) Accordingly, the invention processes for selective Cracking of molecules with a small CSA diameter provided. An example of such a process is dewaxing a hydrocarbon feed by cracking alkanes, leaving behind a product linked to aromatic Hydrocarbons, especially with polynuclear hydrocarbons, enriched is. Such a product can be used as a lubricating oil base stock or as a source of intermediates be used for chemical processing.

Example 1 Cracking hexadecane samples (0.26 ml) of MCH as follows described were filled into a pulse microreaction container and through 1 hour Activated heating to 450 ° C in a stream of air (3 l / h) at a pressure of 4.46 bar. Then the air was passed through a stream of nitrogen at the same speed and had the same pressure, and was upstream of the catalyst at 45000 a hexadecane sample (1 µl) was injected. The one leaving the catalyst Gas was analyzed by gas chromatography. For all samples, the hydrocarbon product distribution showed that the only products are hydrocarbons with fewer than 6 carbon atoms were formed. Details about the catalyst and the percentage conversion are shown in Table II.

Table II catalyst conversion Composition (%) A RE-MCH 99.1 B H-MCH 99.9 C RE-MCH 99.9 X Parental Earth Metal Example 2 (a) Example 1 was repeated with 1 µl samples of decalin (52% cs, 48% trans). The product distribution, percent conversion and percent yields are shown in Table III. It should be noted that as a result of the analytical method used, the C8-C10 fraction contains some C7 aromatics and the C11-C15 fraction contains some C10 aromatics. It does not contain any remaining coke on the catalyst.

(b) Example 1 was repeated with 1 liter samples of 1-methylnaphthalene. The results are shown in Table IV. In the specified C1l + fraction is does not contain any unconverted input material.

The results show that the activity of MCH, in particular of H-MCH, in terms of cracking of polynuclear hydrocarbons is than in relation to the cracking of xexadecane and that MCH therefore in relation to the removal of alkanes from a mixture with polynuclear hydrocarbons would be effective.

Table III Catalyst ABC Products (%) below C6 10.6 4.0 11.0 C6 + C7 17.1 2.7 13.6 C8 - C10 14.3 1.6 12.9 trans- 37.5 45.2 39.4 Decalin cis-decalin 20.5 46.5 23.0 Conversion (%) 42.0 8.3 37.6 Yield (%) below C6 25.2 48.2 29.4 C6 + C7 40.7 32.5 36.1 C8 - C10 34.1 19.3 34.4 Table IV Catalyst ABC Products (%) <C6 0 0 0 C6 + C7 0 0 0 C8 - C10 0 0 0 Naphthalene 19.1 2.7 19.7 1-methylnapthalene 64.8 97.3 66.9 C11 + 16.1 0 13.4 Conversion (%) 35.2 2.7 33.1 Yield (%) <C6 0 0 0 C6 + C7 0 0 0 C8 - C10 0 0 0 Naphthalene 54.3 100 59.5 C11 + 45.7 0 40.5 Example 3 Cracking of a mixture (gas oil) Example 1 was repeated with 1 μl samples of an Ekofisk light gas oil (initial boiling point: 205 ° C.; final boiling point: 390 ° C.; mean average boiling point: 300 ° C.). The results are shown in Table V.

TABLE V Catalyst ABC Products (%) <C6 44.6 43.9 42.3 C6 + C7 11.2 1.5 11.7 C8 ~ C10 17.4 | 5.5 20.3 C11 + 26.9 49.1 25.7 Conversion (%) 73.1 50.9 74.3 Yield (%) <C6 61.0 86.2 56.9 C6 + C7 15.2 3.0 15.8 C8 - C10 23.8 10.8 27.3 Example 4 Cracking a Mixture (light cycle oil) Example 4 was repeated with 1 µl samples of a light cycle oil from a catalytic cracking plant. The results are shown in Table VI.

Table VI Catalyst ABC Products (%) <C6 11.1 19.5 5.6 C6 + C7 2.3 <0.1 0.7 C8 - C10 10.6 3.2 9.1 C11 + 76.0 77.3 84.6 Conversion (%) 24.0 22.7 15.4 Yield (%) <C6 46.2 85.9 36.4 C6 + C7 9.6 0.2 4.6 C8 - C10 44.2 14.1 59.1 Example 5 131 Formation of gaseous hydrocarbons from n-hexane or methanol A microreaction vessel set up for the analysis of C1-C4 hydrocarbons was operated first with a fresh sample of catalyst A and then with a different preparation, a rare earth metal MCH (catalyst Fg. Each catalyst test consisted of one batch using n-hexane, one batch using methanol, injecting 100 μl of methanol to simulate aging, and then a second batch using n-hexane and one batch using methanol 0.6 µl of the starting material was used, while the remaining experimental conditions were essentially the same as the experimental conditions of Example 1. The product gas compositions are shown in Table VII.

Table VII Catalyst AAAAFFFF (condition) (fresh) (fresh) (aged) (fresh) (fresh) (aged) (aged) (aged) Feed material hexane methanol hexane methanol hexane methanol hexane methanol T (° C) 475 450 475 450 475 450 475 450 Gas (vol .-%) CH4 30.5 9.6 2.0 14.3 1.6 7.4 1.7 7.2 C2H6 8.2 1.2 2.2 1.2 2.0 2.8 2.1 2.7 C2H4 11.5 33.4 10.2 24.2 8.1 18.9 8.7 16.4 C3H8 41.2 38.4 41.9 32.4 61.5 49.9 59.4 59.0 C3H6 4.7 5.5 31.8 14.8 11.1 4.2 11.7 4.1 i-C4H10 0 0.2 0 0.1 0.7 2.2 0.2 0 n-C4H10 3.9 11.0 5.5 9.7 11.2 14.5 12.0 9.9 1-C4H8 0 0 1.1 5.5 9.7 1.2 14.5 12.0 9.9 i-C4H8 0 0 1.9 1.8 1.4 0 1.6 0.7 2-C4H8 0 0 3.4 1.4 1.7 0 1.8 0 Example 6 Conversion of methanol over ion-exchanged MCH samples Under the conditions of Example 5, the following catalysts were tested: B H-MCH D Ba-MCH E Ca-MCH The results are shown in Table VIII.

Table VIII BBDDEE Catalysis sator (geal (geal- (geal- (State) (fresh) tert) (fresh) tert) (fresh) tert) T (° C) 450 450 450 450 450 450 Gas (vol. CH4% 3.6 2.1 4.1 2.8 4.7 4.7 C2H6 0.2 0.9 0.2 1.0 0.2 0.3 C2H4 16.6 16.2 15.1 18.2 16.2 21.5 C3H8 22.4 33.2 24.7 29.7 26.5 30.2 C3H6 41.2 18.4 32.5 39.7 42.1 28.3 i-C4H10 O 0 0 0 0 0 n-C4H10 | 4.9 | 23.4 | 10.5 | 4.0 | 4 6.2 | 13.7 1-C4H8 2.7 0.5 2.0 1.1 0.7 0 i-C4H8 2.0 0.6 1.0 0.3 0.6 <0.1 2-C4H8 4.9 3.2 6.3 3.2 2.7 <0.1

Claims (14)

Claims 1. Process for the production of a hydrocarbon, whose molecules contain 6 or fewer carbon atoms, characterized in that that you have a feed consisting of a product that is different from the product to be manufactured Hydrocarbons, the molecules of which contain two or more carbon atoms, uid / or a hydrocarbon derivative containing hydrogen-carbon bonds, reacted over a catalyst containing a zeolite MCH. 2. The method according to claim 1, characterized in that the catalyst contains a zeolite MCH which has been synthesized under conditions which lead to the simultaneous formation of up to 30 wt. gmelinite. 3. The method according to claim 1 or 2, characterized in that the catalyst is a zeolite MCH with an alkali metal content of less than 2% by weight, calculated as Na20 equivalents. 4. The method according to any one of the preceding claims, characterized in that that the catalyst contains a zeolite MCH, in which the alkali metal ions at least partly by hydrogen ions and / or by polyvalent ions of metals Group II or the rare earth group of the periodic table are. 5. The method according to any one of the preceding claims, characterized characterized in that the catalyst contains a zeolite MCH with 10 to 40% by weight of a diluent is mixed. 6. The method according to any one of the preceding claims, characterized in, that the feed material consists of a hydrocarbon which is gaseous under normal conditions or a mixture of such hydrocarbons or from an easily vaporizable one Hydrocarbon or a mixture of such hydrocarbons. 7. The method according to any one of the preceding claims, characterized in, that one carries out selective cracking of a hydrocarbon in the process, which has molecules with a small CSA diameter, d. i.e., molecules whose Width in the plane of the minimum cross-sectional area is small. 8. The method according to claim 7, characterized by the dewaxing of a hydrocarbon feed in which alkanes are cracked and on mi aromatic Kohleriwasse enriched product is obtained. 9. The method according to any one of the preceding claims, characterized in, that the feed is one of alcohols, ethers, carboxylic acids, esters, aldehydes and ketones and their acetals contains selected, oxidized hydrocarbons. 10. The method according to claim 9, characterized in that the output Contains methanol and / or dimethyl ether. 11. The method according to any one of claims 1 to 6, 9 and 10, characterized characterized in that the reaction temperature is in the range of 300 to 450 ° C. 12. The method according to any one of claims 1 to 6, 9 and 10, characterized characterized in that the reaction temperature is in the range from 400 to 550 ° C. 13. The method according to any one of the preceding claims, characterized in that that the reaction pressure is in the range from 1 to 51 bar abs. lies. 14. The method according to any one of the preceding claims, characterized in, that it is in conjunction with a process for the synthesis of hydrocarbons and / or oxidized hydrocarbons through the catalytic conversion of carbon oxides is applied with hydrogen.