NL8102071A - Hydrocarbon prodn. from coal - by solvent extn., gasification and hydrocarbon synthesis - Google Patents

Abstract

Prodn. of hydrocarbon distillates from coal is carried out by (a) extracting the coal with a solvent to obtain a coal extract in a yield of 5-30 (pref. 7.5-20) wt.% based on MAF coal; (b) catalytically hydrotreating the extract to produce a 1st hydrocarbon distillate; (c) gasifying the residue from (a) to produce synthesis gas; (d) catalytically converting at least part of the synthesis gas to a 2nd hydrocarbon distillate; and (e) subjecting the rest of the synthesis gas (if any) to shift conversion to produce H2 for use in step (b). The process gives up to 30% higher distillate yields than straight- forward gasification and hydrocarbon synthesis.

Description

*

K 5562 NET

PROCESS FOR PREPARING HYDROCARBONS

The invention relates to a process for the preparation of hydrocarbon distillates from coal. Hydrocarbon distillates such as gasoline, kerosene and gas oil are mainly obtained by distillation of crude oil as well as by build-up processes such as alkylation and polymerization and degradation processes such as thermal and catalytic cracking applied to light and / or light. heavy hydrocarbon mixtures obtained from the extraction and processing of crude oil. As the availability of crude oil decreases, there is an increasing interest in the preparation of the above liquid fuels from coal.

The Applicant has conducted an investigation into the preparation of hydrocarbon distillates from coal via the so-called gasification / synthesis route. According to this route, the coals are gasified with oxygen and the thus obtained H2 / CO human gel, after possibly having applied a CO shift thereon to increase the H2 / CO molar ratio, is catalytically converted into hydrocarbon distillates. By choosing the conditions of the different process steps as optimally as possible and adjusting the process steps to each other as well as possible, a given maximum quantity of hydrocarbon distillates of the given quality can be prepared starting from a coal type 8102071 _ 2 - * 1 with given quality. Starting from a coal type with an average H / C atomic ratio of about 0.9, this maximum yield of hydrocarbon distillates appears to be about 20% by weight, if one is satisfied with a product whose average H / C atomic ratio is about 1.7. amounts.

The quality of coal and liquid hydrocarbon distillates is expressed in this patent application in the average H / C atomic ratio, the quality being considered the better as the average H / C atomic ratio is higher. All average H / C atomic ratios of 15 coal stated in this patent application as well as all declared yields calculated on coal refer to the coal in a moisture and ash-free state (so-called "VAV coal"). In this patent application, hydrocarbon distillates are understood to be mixtures of hydrocarbons with at least 20 five carbon atoms per molecule and a boiling point of at most 520 ° C.

Further research by the Applicant on the preparation of hydrocarbon distillates from coal via the gasification / synthesis route has shown that the yield of hydrocarbon distillates can be significantly increased by subjecting the coal to a mild extraction prior to gasification and applying the extract obtained to the extract. apply catalytic hydrotreating. The extraction should be carried out in such a way that at least 5% by weight but with more than 30% by weight (based on VAV coal) of coal extract is obtained. The catalytic hydrotreating has, inter alia, the aim of removing oxygen, sulfur and nitrogen from the coal extract and increasing the average H / C atomic ratio. As the conditions under which the catalytic 8102071

V

». > - 3 - hydrotreating is carried out are chosen more heavily, cracking of the coal extract occurs to a greater extent, resulting in hydrocarbon distillation with a higher average H / C atomic ratio, but whereby as a result of the formation of gaseous cracking products, the yield of hydrocarbon distillation decreases.

The research by the Applicant has shown that starting from the aforementioned coal type with an average H / C atomic ratio of approximately 0.9 and using the described combination of mild extraction, catalytic hydrotreating, gasification and hydrocarbon synthesis (hereinafter referred to briefly as "combination route") »by choosing the conditions of the various process steps as optimally as possible and adjusting the process steps as well as possible to each other, you can achieve a gain of approximately 30% in yield of hydrocarbon distillates compared to the gasification / synthesis route, if, like the latter route, one is satisfied with hydrocarbon distillates as a product with an average H / C atomic ratio of about 1.7. If one starts from higher quality coal and / or settles for lower quality hydrocarbon distillates, higher yields of hydrocarbon distillates can of course be obtained both by using the gasification / synthesis route and by using the combination route. However, the profit in yield when applying the combination route remains unaffected.

With regard to the above-mentioned maximum achievable gain in yield of hydrocarbon distillates of approximately 30%, the following should also be noted.

The catalytic hydrotreatment which is part of the combination route consumes hydrogen. The required amount of hydrogen can be supplied from the outside to the combination route 8102071 fr 5 - k - or it can be prepared as part of the combination route by preparing hydrogen from part of the H2 / CO mixture obtained during the gasification. . If desired, part of the required hydrogen can be prepared as part of the combination route while the rest is supplied to the combination route from the outside. The use of part of the H2 / CO mixture to prepare hydrogen, which hydrogen is used in the catalytic hydrotreatment, obviously means that the amount of H2 / CO mixture available as feed for the hydrocarbon synthesis is lower, decreasing the yield of hydrocarbon distillates. However, the investigation by Applicant 15 has shown that if, in the situation outlined above, in which the extraction and hydrotreating are carried out such that a yield in hydrocarbon distillates yield of about 30% is achieved, all hydrogen required for the catalytic hydrotreating is prepared from the H2 / CO mixture, the gain in yield of hydrocarbon distillates compared to the gasification / synthesis route, is still approximately 25%.

The following can be noted with regard to the amount of extract to be separated from the coal in the combination route. As a larger amount of extract is separated from the coal and subjected to a catalytic hydrotreatment, initially the yield in hydrocarbon distillates yields increases in the combination route. After reaching a maximum value, a fairly rapid decline in profit occurs. There are several reasons for this rather rapid decline in the yield of hydrocarbon distillates. In the first place, to achieve a higher yield of extract 81 02 0 7 1 Λ- Λ - 5 -, heavier extraction conditions must be used. More severe extraction conditions, however, lead to a strong formation of gaseous by-products, whereby the yield of coal residue (the feed for the gasification / synthesis) decreases sharply. Secondly, the higher the extract yield, the heavier and the lower the quality of this extract. In order to still produce hydrocarbon distillates of an acceptable quality from such an extract, more severe conditions will have to be applied in the catalytic hydrotreating. More severe conditions in catalytic hydrotreating, however, lead to a strong formation of gaseous by-products. Despite the harsh conditions in the catalytic hydrotreating process, a significant portion of the treated heavy extract will remain as a 520β + residue after distillation.

The investigation by the Applicant has shown that if the extraction is carried out in such a way that at least 5, but not more than 30% by weight of extract is obtained, the combination route yields a gain in liquid hydrocarbon yield, compared to the gasification yield / synthesis route, which is such that it outweighs the additional costs associated with the inclusion of an extraction and catalytic hydrotreating plant in the coal processing process. The investigation has further shown that if significantly more than 30% by weight of extract is extracted from the coal, the preparation of acceptable quality hydrocarbon distillates from this extract requires so much hydrogen that a situation is soon reached in which practically all H 2 / CO mixture is required to prepare the required amount of hydrogen and / or the total yield of hydrocarbon distillates is even lower than that obtained using 81 02 0 7 1 S '. i '- 6 - the gasification / synthesis route.

The present patent application therefore relates to a process for the preparation of hydrocarbon distillates from coal, wherein the coal is treated with a solvent, whereby a part is extracted from the coal, the amount of which is 5-30% by weight, based on the amount of extracted coal in a moisture- and ash-free state, the part extracted from the coal being subjected to a catalytic hydrotreating process to prepare a first hydrocarbon distillate, the residue obtained during the extraction being converted by gasification into a mixture of carbon monoxide and hydrogen, and at least part of the H2 / CO mixture is catalytically converted into a second hydrocarbon distillate, it being understood that if only part of the H2 / CO mixture is used as feed for the catalytic hydrocarbon synthesis, the remainder is used to pass through CO -shift to prepare 20 hydrogen, which wa terrestrial material is used in the catalytic hydrotreating.

The method according to the invention starts from coal as raw material. Very suitable coal for the present purpose are brown coal, sub-bituminous coal and bituminous coal.

The first process step in the method according to the invention is an extraction. This extraction is preferably carried out in such a way that at least 7.5 wt.% But with more than 25 wt.% Extract is obtained. The extraction takes place by keeping the coal in contact with an aromatic solvent at elevated temperature and pressure for some time. Suitable aromatic solvents are ring aromatics such as benzene, two condensed ring aromatics such as naphthalene and three condensed ring aromatics such as anthra- 81 0 2 0 7 1 3 * - T - cene and phenanthrene. Derivatives of the above aromatics such as toluene, xylenes and durene are also suitable as solvents. A very suitable solvent for the present purpose is a light oil 5 which can be obtained as a distillate in the distillation of a coal extract. The extraction can be carried out under the following conditions: a temperature of 300-500 ° C, a pressure of 50-250 bar, a residence time of 2-100 minutes and a weight ratio of solvent / VAV coal of 0.75-5. extraction is preferably carried out under the following conditions: a temperature of 350 - 450 ° G, a pressure of 100 - 200 bar, a residence time of 10 - 50 minutes and a weight ratio of solvent / VAV coal of 1-3. Particular preference is given to carrying out the extraction under supercritical conditions, ie at a temperature above the critical temperature of the solvent used. Preferably, the supercritical extraction uses a temperature which is not more than 50 ° C above the critical temperature of the solvent used. The extraction produces a coal extract and a coal residue.

In the process of the invention, the coal extract is subjected to a catalytic hydrotreatment. The conditions under which the catalytic hydrotreatment must be carried out are mainly determined by the chemical composition and boiling point distribution of the components present in the coal extract to be treated and the requirements, in particular the boiling point distribution, which are imposed on the hydrocarbon distillate to be prepared. . If the coal extract has a boiling point distribution substantially similar to that of the desired hydrocarbon distillate, a relatively mild catalytic hydrotreatment will suffice, which in 8102071-8 mainly serves to sufficiently provide the oxygen, sulfur and nitrogen contents of the coal extract to lower. As a larger amount of extract is separated from the coals, the extracts in question will contain a relatively larger amount of non-distillable components and hetero compounds. In order to prepare a sufficient amount of boiling-water distillate of acceptable quality from such a coal extract, considerably more severe conditions will have to be used in the catalytic hydrotreating process, whereby cracking of the coal extract occurs to a considerable extent.

This also applies even if a relatively light coal extract is available which consists predominantly of distillatable components, but which boils mainly above the petrol range, while it is desired to prepare mainly petrol therefrom by catalytic hydrotreating. In the process of the invention, J / the catalytic hydrotreating can be carried out in one or more steps. A two-step catalytic hydrotreating is often preferred if cracking is to be expected to occur to a significant degree. The catalytic treatment is then preferably carried out in such a way that in the first step there is mainly a decrease in the content of hetero atoms, in particular nitrogen, while the cracking to desired light products mainly takes place in the second step.

The catalytic hydrotreatment can be carried out at a temperature of 350-500 ° C, a pressure of 50-250 bar, and a spatial throughput of 0.1-10.1. Suitable catalysts are those containing one or more metals with hydrogenation activity on a support. Examples of suitable metals are nickel, cobalt, chromium, molybdenum and 8102071 a-9 tungsten, in particular combinations of these metals such as nickel molybdenum, cobalt molybdenum and nickel wolf window. Suitable carrier materials are silica, alumina, zirconia and magnesia and combinations thereof such as silica-alumina as well as zeolitic materials such as faujasite. If desired, the catalysts can also contain promoters such as halogen, phosphorus or boron. The catalytic hydrotreating is preferably carried out at a temperature of 375 - 450 ° C, a pressure of 100 - 200 bar and a spatial throughput of 0.25 - 2.1 ° C. hours ~ ^.

In the process according to the invention, the coal residue is converted into a mixture of carbon monoxide and hydrogen by gasification with oxygen or air.

The gasification is preferably carried out in the presence of steam as a moderator. Suitable conditions for carrying out the gasification are a temperature (measured at the outlet of the reactor) of 1000 -2000 ° C and preferably of 1200 - 1800 ° C and a pressure of 20 1 - 150 bar and preferably of 10 - 100 bar. The synthesis gas obtained during the gasification, which mainly consists of H2, CO, CO2 and H2O, contains solid impurities such as ash particles and carbon-containing particles and gaseous impurities such as NH3, H2S and COS. To remove these impurities, the gas at a temperature above 1000 ° C is first cooled. This cooling can very suitably take place in a boiler in which steam is generated with the aid of the waste heat. After purification, the synthesis gas 30 is suitable for further processing.

In the process according to the invention, a catalytic hydrocarbon synthesis is applied to at least part of the synthesis gas. If only part of the synthesis gas is used as feed for the hydrocarbon synthesis, the remaining part should be used • 81 0 2 0 7 1 - 10 - to produce hydrogen by CO2 shift, which hydrogen is used in the catalytic hydrogen treatment. The process according to the invention is preferably carried out in such a way that the complete hydrogen requirement of the catalytic hydrotreatment is met by hydrogen which has been prepared from a part of the synthesis gas via C0-shift. The C0 shift can be carried out by contacting the CO-containing gas together with steam at an elevated temperature and pressure with a suitable catalyst. H £ is formed from CO according to the reaction CO + H2O - * · H2 + CO2 · The C0 shift can be carried out at temperatures between 175 and 425 ° C, pressures between 10 and 100 bar and using a 15 H2O / CO molar ratio between 1 and 150. Suitable catalysts for carrying out the C0 shift contain one or more metals selected from a group formed by iron, chromium, copper, zinc, cobalt, nickel and molybdenum as catalytic component, or as such either in the form of their oxide or sulfide. A very suitable catalyst for the present purpose in a catalyst containing both copper and zinc, in particular a catalyst in which the Cu / Zn atomic ratio is between 0.25 and 4.0.

The catalytic hydrocarbon synthesis used in the process of the invention can be carried out in one step or two steps. An example of a hydrocarbon synthesis carried out in one step is that in which the synthesis gas is contacted with an iron-containing bifunctional catalyst which, in addition to activity for the conversion of an H 2 / CO mixture to substantially acyclic hydrocarbons, CO- shift activity. (hereinafter referred to as a type A catalyst for brevity). Examples of suitable catalysts of 8102071-11 type A are: a) Catalysts containing 30-75 parts by weight of iron and 5-40 parts by weight of magnesium per 100 parts by weight of alumina and which have been prepared by impregnating an alumina support. 5 with one or more aqueous solutions of iron and magnesium salts followed by drying the composition, calcining at a temperature of 700-1200 ° C and reducing. Preference is given to such catalysts which, in addition to 40-60 parts by weight of iron and 7.5-30 parts by weight of magnesium, 0.5-5 parts by weight of copper as a reduction promoter and 1 - 5 parts by weight. parts of potassium as selectivity promoter per 100 parts by weight of alumina, which are calcined at 750-850 ° C and reduced at 250-350 ° C.

B) Catalysts containing 10 to 40 parts by weight of iron and 0.25 to 10 parts by weight of chromium per 100 parts by weight of silica and which have been prepared by impregnating a silica support with one or more aqueous solutions of salts of iron and of chromium followed by drying, calcining and reducing composition 20 at a temperature of 350-700 ° C. Preference is given to such catalysts which, in addition to 20-35 parts by weight of iron and 0.5-5 parts by weight of chromium, contain 1-5 parts by weight of potassium as a selectivity promoter per 100 parts by weight of silica, and which are used at 350-500 ° C are reduced.

An example of a two-step hydrocarbon synthesis is that in which the synthesis gas is contacted in a first step with a type A catalyst and where carbon monoxide and hydrogen are present in the first step reaction product, optionally together. with other components of this reaction product, are contacted in a second step with a cobalt-containing catalyst which has activity for the conversion of an H2 / CO mixture into mainly acyclic hydrocarbons 81 0 2 0 7 1 __ · * · 'β - 12 (hereinafter referred to as a type B catalyst for brevity), care should be taken to ensure that the feed for the second step has an H 2 / CO mole ratio of at least 1.5. Preferably 5 this molar ratio 1.75 to 2.25 An example of a suitable type B catalyst is a catalyst containing 10 -40 parts by weight of cobalt and 0.25-5 parts by weight of zirconium, titanium or chromium per 100 parts by weight .share contains silica prepared by impregnating a silica support with one or more aqueous solutions of cobalt salts and of zirconium, titanium or chromium followed by carrying the composition, calcining at 350 - 700 ° C and reducing at 200 - 700 350eC. The catalytic hydrocarbon synthesis is preferably carried out using a trifunctional catalyst combination which, in addition to activity for the conversion of an H 2 / CO mixture to substantially acyclic hydrocarbons and / or acyclic oxygen-containing hydrocarbons, as well as activity for the conversion of acyclic hydrocarbons and / or acyclic oxygenated hydrocarbons to substantially aromatic hydrocarbons, have CO shift activity. As a component with activity for the conversion of acyclic hydrocarbons and / or acyclic oxygen-containing hydrocarbons to mainly aromatic hydrocarbons, these trifunctional catalyst combinations preferably contain a crystalline metal silicate of special structure.

The crystalline metal silicates of particular structure referred to herein are characterized in that after one hour of calcination in air at 500 ° C, they have the following properties 1) thermally stable to a temperature of at least 600 ° C, 2) an X-ray powder diffraction pattern which is shown in Table A listed four lines as strongest lines contains 8102071? y - 13 -

Table A

d i £ Relative intensity

11.1 +0.2 ZS

5 10.0 +0.2 ZS

3.84 + 0.07 S

3.72 + 0.06 S

in which the letters used have the following meaning: ZS = very strong; S = strong, 10 3) in the formula which represents the composition of the silicate, expressed in moles of the oxides and in which, in addition to oxides of hydrogen, alkali and / or alkaline earth metal and silicon, one or more oxides of a trivalent metal A are selected from the group formed by iron, aluminum and gallium, the SiO 2 / A 2 O 3 molar ratio (m) is more than 10.

In this patent application, a crystalline silicate with a thermal stability of at least t ° C is understood to mean a silicate whose x-ray powder diffraction pattern does not substantially change when heated to a temperature of t ° C.

The above-mentioned crystalline metal silicates, which for the sake of brevity are referred to in this patent application as "silicates with special structure", have the attractive property that, when used as a catalyst for the preparation of aromatics, irrespective of the number of carbon atoms in the compound used as feed, deliver product in which the aromatics contain substantially less than 12 carbon-30 atoms. The latter property is considered to be very important, since aromatic hydrocarbons with less than 12 carbon atoms in the molecule are excellently useful as gasoline components.

The hydrocarbon synthesis of the invention using a trifunctional catalyst combination 81 02 0 71 ___ «* * - - 14 - which contains a silicate of particular structure can be carried out in one or two steps. An example of such a hydrocarbon synthesis which is carried out in one step is that in which the synthesis gas is contacted with a trifunctional catalyst combination consisting of a mixture of a silicate of special structure and a bifunctional catalyst which besides conversion activity from an H 2 / CO mixture to mainly acyclic hydrocarbons and / or acyclic oxygen-containing hydrocarbons, has CO shift activity. As bifunctional catalysts which, in addition to activity for the conversion of an H 2 / CO mixture into mainly acyclic hydrocarbons, have CO-shift activity, the aforementioned type A catalysts can very suitably be used. Preferably, a bifunctional catalyst is used in the trifunctional catalyst combination which, in addition to CO-shift activity, has activity for the conversion of an H2 / CO 20 mixture into mainly acyclic oxygen-containing hydrocarbons, in particular a catalyst containing mainly methanol and / or dimethyl ether forms. Very suitable for this purpose is a ZnO-Cr2Q3 composition and in particular such a composition in which the atomic percentage of zinc based on the sum of zinc and chromium is at least 60% and preferably 60 - 80%.

An example of a catalytic hydrocarbon synthesis using a trifunctional catalyst combination containing a crystalline silicate of particular structure and which synthesis is carried out in two steps is that in which the synthesis gas is contacted in the first step with a trifunctional catalyst combination such as described above and wherein carbon monoxide and hydrogen present in the first step reaction product, optionally together with other components of this reaction product, are contacted in the second step with a type B catalyst, whereby as in the two-step process discussed earlier, should ensure that the feed for the second step has an H2 / CO molar ratio of at least 1.5. In the process of the invention, it is highly preferred to carry out the hydrocarbon synthesis according to the two-step process described above using a trifunctional catalyst combination containing a crystalline silicate of particular structure, in the first step. The first step of the two-step process is preferably carried out at a temperature of 200 - 500 ° C and in particular of 250 - 450 ° C, a pressure of 1 - 150 bar and in particular of 5 - 100 bar and a spatial throughput of 50 - 5000 and in particular of 300 - 3000 En.1 "^ ·· hour" ^. The second step of the two-step process is preferably carried out at a temperature of 125-350 ° C and in particular of 175-275 ° C and a pressure of 1-150 bar and in particular of 5-100 bar.

In the gross formula of the silicates with special structure, m should have a value above 10. For use in the process according to the invention, preference is given to silicates with an m less than 1000 and in particular less than 400 as well as for silicates with a value for m greater than 20. Although the silicates with special structure can in principle contain more than one trivalent metal A, the preference is given to the use of those silicates which contain only one metal A, in the contain particularly iron or aluminum. Due to the way in which they are prepared, the silicates of special structure contain exchangeable alkali and / or alkaline earth metals. - 81 02 071 - 16 -

ions. For catalytic applications it is preferred to use silicates whose alkali metal content has been reduced to less than 0.05% by weight. The silicates with special structure are defined, inter alia, on the basis of the X-ray powder diffraction pattern that they display after calcining in air at 500 ° C for an hour. This should include the four lines listed in Table A as the strongest lines. The complete X-ray powder diffraction pattern of a typical example of a silicate of particular structure is shown in Table B

Table B

d (&) Rel, int. d (&) Rel, int.

15 · 11.1 100 3.84 (D) 57 10.0 70 3.70 (D) 31 8.93 1 3.63 16 7.99 1 3.47 1 7.42 2 3.43 5 20 6.68 7 3 , 34 2 6.35 11 3.30 5 5.97 17 3.25 1 5.70 7 3.05 8 5.56 10 2.98 11 25 5.35 2 2.96 3 4.98 (D) 6 2.86 2 4 , 60 4 2.73 2 4.35 5 2.60 2 4.25 7 2.48 3 30 4.07 2 2.48 2 4.00 4 (D) = doublet

As noted above, in 81 0 2 0 7 1 _ - π - performance of the hydrocarbon synthesis using a catalyst containing a silicate of particular structure, an aromatic hydrocarbon mixture is obtained which boils for a significant part within the gasoline range . A component which can occur in relatively high concentration in the aromatic hydrocarbon mixture is dureen. In view of the high melting point of durene (approx. 80 ° C), the presence of this component can be a drawback, for example if it is the intention to add the fraction of the hydrocarbon mixture obtained as motor gasoline that is suitable for this on the basis of the boiling range to fit. The investigation by the Applicant has shown that the method according to the invention offers a number of attractive possibilities for solving any problems that may arise in connection with avoid too high a concentration of dureen in the gasoline fraction. These possibilities are based on the following considerations 1) The gasoline fraction obtained in the catalytic hydrotreating generally has a relatively low aromatic content.

2) Dureen can be easily separated from a gasoline fraction.

3) Hydrogenation of durene gives hexahydrodurene (boiling point about 170 ° C), which is a very attractive gasoline component.

4) Dureen is an excellent coal extractant.

5) In extraction, it is customary to recycle the extractant used. Extraction 30 generally loses part of the extractant, for example due to decomposition and because small amounts of extractant remain in the coal extract or coal residue. Therefore, in order to keep the amount of extractant constant, during the extraction fresh extractant of 81 02 0 71 - 18 - must be added to the process externally. This is recognized as a drawback of the extraction process.

This drawback lapses if the extractant used is formed as a more or less undesirable by-product during the process.

In view of any problems which may arise as a result of a high concentration of durene in the gasoline fraction prepared in the hydrocarbon synthesis and taking into account the above considerations, the following variants can be used in the process according to the invention 1) For the preparation of a gasoline having a sufficiently high aromatic content and a sufficiently low duration content, at least part of the gasoline fraction obtained from the catalytic hydrotreating is mixed with at least a part of the gasoline fraction obtained from the hydrocarbon synthesis.

2) At least a part of the durene is separated from the gasoline fraction obtained in the hydrocarbon synthesis and this durene is used a) at least partly as an extractant for the coal and / or b) at least partly together with the coal extract subjected to the catalytic hydrotreatment.

When using durene as an extraction agent, the process can very suitably be carried out in such a way that all durene which is separated from the gasoline fraction is fed to the extraction installation and that the mixture of coal extract and dureen obtained during the extraction is fed to the extraction plant. only part of the durene separates and recirculates to the extraction plant and the rest of the dureen is subjected to the catalytic hydrotreating treatment together with the coal extract.

The invention is now illustrated by the following example.

8102071 ___ - € - 19 -

Example

The following catalysts were used in the study ^ Catalyst 1

Ni / Mo / P / F / Al2 O3 catalyst containing 3.6 parts by weight of Ni, 14.7 parts by weight of Mo, 3.3 parts by weight of P and 7.8 parts by weight of F per 100 parts by weight of Al2O3.

Catalyst 2

Cu / Zn / Al2 O3 catalyst with a Cu / Zn atomic ratio of 0.55.

Catalyst 3

ZnO-Cr 2 O 3 catalyst in which the atomic percentage of zinc based on the sum of zinc and chromium was 70%.

Catalyst 4 20

Co / Zr / SiO 2 catalyst containing 25 parts by weight of cobalt and 1.8 parts by weight of zircon per 100 parts by weight of silica and which was prepared by impregnating a silica support with an aqueous solution containing a cobalt and a zirconium salt, followed by drying the composition, calcining at 500 ° C and reducing at 280 ° C.

Catalyst 5

A crystalline iron silicate was prepared by an aqueous mixture of SiO 2, NaOH, (CgHy 2 NOH and

Fe (NO3) 3 of the following molar composition 1Na2O1.5 (/ 03 ^) 4¾] 20.0.125Fe2O3 · 25SiO2 · 468H20, in an autoclave under autogenous pressure for six hours at 150 ° C. After cooling of the reaction mixture, the resulting iron silicate was filtered off, washed 81 02 0 7 1 __ -20--

v X

with water until the pH of the wash water was about 8, dried at 120 ° C and calcined in air at 500 ° C for one hour. The iron silicate thus obtained had the following properties 1) thermally stable to a temperature of at least 800 ° C, 2) an X-ray powder diffraction pattern substantially corresponding to that stated in Table B, and 3) an SiO 2 / Fe 2 O 3 molar ratio of 200.

A catalyst 5 was prepared from the iron silicate by boiling the iron silicate with 1.0 molar NH4NQ3 solution, washing with water, boiling again with 1.0 molar NH4NO3 solution and washing, drying and calcining.

15

Catalyst 6

This catalyst consisted of a physical mixture of catalyst 3 and catalyst 5 in a volume ratio of 2: 1 20

The above-mentioned catalysts were used in four experiments to prepare hydrocarbon distillates from coal. In the experiments, the. the following process steps were applied: gasification, hydrocarbon synthesis, C0 shift, extraction and catalytic hydrotreating. All experiments were based on the same brown coal which had an average H / C atomic ratio of 0.88. The gasifications were carried out with oxygen at a pressure of 60 bar and using steam as a moderator. In all cases, a virtually complete conversion was achieved during the gasification. NH3, H2S and COS were removed from the crude synthesis gas which, in addition to H2 and CO, also contained NH3, H2S, COS, CO2 and H2O. A two-stage catalytic hydrocarbon synthesis was applied to the synthesis gas thus purified in two reactors of 50 ml each containing a fixed catalyst bed with a volume of 7.5 ml. In the first reactor there was catalyst 6 and in the second reactor catalyst 4. The total reaction product from the first step was used as feed for the second step. The catalytic hydrocarbon synthesis was carried out at a pressure of 60 bar and a spatial throughput based on the sum of the total catalyst system of 500 Nl.1 "*. hour"·*·.

The temperature in the first step was 375 ° C and that in the second step was 220 ° C. The coal extractions were carried out at a pressure of 150 bar, a residence time of 30 minutes and a weight ratio of solvent / VAV coal 2: 1. Catalytic hydrotreatment was applied to the coal extracts in a 50 ml reactor containing a solid catalyst bed with a volume of 7.5 ml. Catalyst 1 was used as the catalyst. The catalytic hydrotreating of the coal extracts was carried out at a pressure of 150 bar and a spatial throughput of 0.5 1.1 "*. hour-·*·. The CO shift was performed in a 50 ml reactor containing a 7.5 ml fixed catalyst bed. Catalyst 2 was used as the catalyst. The CO shift was carried out at a temperature of 220 ° C, a pressure of 60 bar and a spatial throughput of 200 1.1 "*. hour"*·. The other conditions used in each of the process steps as well as the results obtained are listed below.

30 Experiment 1

Gasification of 100 parts by weight of VAV coal and hydrocarbon synthesis applied to the synthesis gas. Gasification temperature: 1530 ° C O2 / VAV coal weight ratio: 0.8 Steam / 02 weight ratio: 0.1 81 02 0 71 w% - 22 -

Yield of purified synthesis gas: 189 parts by weight. The product obtained in the hydrocarbon synthesis was composed as follows: 144 parts by weight CO2 5 11.6 ”H 2 O 10.0” CX-C4 hydrocarbons 22.0 “C5 - 520 ° C fraction with a average H / C atomic ratio of 1.68 1.5 "" 520 ° C + residue 10

Experiment 2

Extraction of 100 parts by weight of VAV coal, catalytic hydrotreating of the coal extract, gasification of the coal residue and hydrocarbon synthesis applied to the synthesis gas.

Extraction temperature: 400 ° C

Extractant used: a mixture of xylenes Result of the extraction: 15.6 parts by weight of CO2 20 0.9 "" CO "5.6" "H20 3.3" "C1-C4 hydrocarbons 12.8" "coal extract 61.8" "coal residue 25 The catalytic hydrotreating of the coal extract was performed at 400 ° C. Hydrogen consumption was 4% by weight (0.5 parts by weight of H2 to 12.8 parts by weight of coal extract). The product obtained in the catalytic hydrotreatment was composed as follows: 1.3 parts by weight of H 2 O 0.5 "" C1-C4 hydrocarbons 11.3 "" C5 - 520 ° C fraction with an average H / C atomic ratio of 1.65 , 2 "" 520 ° C + residue 81 0 2 0 71 '> £ - 23 -

The gasification of the 61.8 parts by weight of coal residue was performed at 1530 ° C using an O2 / residue weight ratio of 0.83 and a steam / O2 weight ratio of 0.10. The yield of purified synthesis gas was 118.4 parts by weight. To the 118.4 wt. parts of synthesis gas were added 5.5 parts by weight of water and hydrocarbon synthesis was applied to the mixture. The product obtained in the hydrocarbon synthesis was composed as follows: 98 parts by weight of CO2 7.8 "" 0 ^ -04 hydrocarbons 17.1 "" C5 - 520 ° C fraction with an average H / C atomic ratio of 1.68 L .0 "" 520 ° C + residue 15

Experiment 3

This experiment was performed essentially in the same manner as Experiment 2, except that in the present case, the hydrogen requirement of the catalytic hydrotreatment was met by applying CO shift to part of the synthesis gas produced. For this purpose, the 118.4 parts by weight of synthesis gas was divided into two portions, i.e. a portion of 5.4 parts by weight and a portion of 113.0 parts by weight. The 5.4 wt portion of synthesis gas was subjected to CO shift after mixing with 3.4 wt parts water. The product from the CO-shift reactor consisted of 0.5 part by weight of H2 and 8.3 parts by weight of CO2 · To the synthesis gas portion of 113.0 parts by weight, 5.5 parts by weight of water were added and hydrocarbon synthesis was applied to the mixture. The product obtained in the hydrocarbon synthesis was composed as follows: »93.8 parts by weight of CO2 7.4” ”C1-C4 hydrocarbons 16.3” ”C5 - 520 ° C fraction with an average 81 02 0 71 - 2k -

v V

H / C atomic ratio of 1.65 1.0 parts by weight 520 ° C + residue

Experiment 4 Extraction of 100 parts by weight of VAV coal, catalytic hydrotreating of the coal extract, gasification of the coal residue, CO shift applied to part of the synthesis gas and hydrocarbon synthesis applied to the rest of the synthesis gas. Extraction temperature: 10 450 ° C. Extractant used: an anthracene oil with a boiling range between 200 and 400 ° C Result of the extraction:

17 parts by weight of CO2. 0.3 "" CO

15 5 "" H20 12 "" C1-C4 hydrocarbons 40 "" coal extract 25.6 "” coal residue

The catalytic hydrotreating of the coal extract 20 was carried out at 420 ° C. The water consumption was 9.5% by weight (3.8 parts by weight of H2 per 40 parts by weight of coal extract). The product obtained in the catalytic hydrotreating process was composed as follows 4.0 parts by weight H 2 O 5 5.1 "C 1 -C 4 hydrocarbons 20" 'C5 - 520 ° C fraction with an average H / C atomic ratio of 1.62 14.6 ”” 520 ° <Γ * · residue

Gasification of the 25.6 parts by weight of coal residue was performed at 1700 ° C using an O 2 / residue weight ratio of 0.3. The yield of purified synthesis gas was 60.4 parts by weight. These 60.4 parts by weight of synthesis gas were split into two portions, namely a 52.1 part by weight portion and a 8.3 part by weight portion. The 52.1 part by weight of 8102071-25 synthesis gas was subjected to CO shift after mixing with 24.9 parts by weight of water to meet the hydrogen requirement of the catalytic hydrotreating. The product from the CO-shift reactor consisted of 3.8 parts by weight of H2 and 73.2 parts by weight of CO2. The parts of synthesis gas of 8.3 parts by weight were 2.2 parts by weight. water was added and hydrocarbon synthesis was applied to the mixture. The product obtained in the hydrocarbon synthesis was composed as follows 10 9.7 parts by weight of CO2 0.24 ”C1-C4 hydrocarbons 0.52” C5 - 520 ° C fraction with an average H / C atomic ratio of 1.68 0 .04 "" 520 ° C + residue 15

Of experiments 1-4 described above, only experiments 2 and 3 are experiments according to the invention. Experiments 1 and 4 are outside the scope of the invention. They are included in the patent application for comparison. The following can be noted with regard to the results of the experiments.

Experiment 1: Application of the gasification / synthesis route to coal with an average H / C atomic ratio of 0.88 yields 22% by weight of hydrocarbon distillates with an average H / C atomic ratio of 1.68.

Experiment 2: Application of the combination route according to the invention to the same coals supplying the process hydrogen requirement from an external source yields a yield of 28.4% by weight of hydrocarbon distillates with an average H / C atomic ratio of 1.67. This represents a gain in hydrocarbon distillate yield over the gasification / synthesis route of 29%.

8102071 te-te -26-

Experiment 3: Application of the combination route according to the invention to the same coal, while internally supplying the hydrogen requirement of the process, yields 27.6% by weight of hydrocarbon distillates 5 with an average H / C atomic ratio of 1.67. This means a gain in hydrocarbon distillation yield over the gasification / synthesis route of 25%. Experiment 4: In this experiment, a process was carried out which is closely related to the combination route jq, but differs in that considerably more than 30% by weight (namely 40% by weight) of extract was separated from the coal. Processing in this manner of the same coal as used in Experiments 1-3 yields 20.5 wt% yield of hydrocarbon distillates with an average H / C atomic ratio of 1.62. This represents a loss in yield of hydrocarbon distillates over the gasification / synthesis route of 7%.

81 0 2 0 7 1

Claims (17)

Process for the preparation of hydrocarbon distillates from coal, characterized in that the coal is treated with a solvent, whereby a part is extracted from the coal, the amount of which is 5-30% by weight, based on the amount extracted coal in a moisture and ash free state, that the part extracted from the coal is subjected to a catalytic hydrotreating process to prepare a first hydrocarbon distillate, that the residue obtained in the extraction is converted by gasification into a mixture of carbon monoxide and hydrogen and that at least part of the H2 / CO mixture is catalytically converted into a second hydrocarbon distillate, it being understood that if only part of the H2 / CO mixture is used as feed for the catalytic hydrocarbon synthesis, the remaining part is used to produce hydrogen by CO-shift, which hydrogen is used in the catalytic hydrogen treatment division. 81 0 2 0 7 1 - 28 - 2. A method according to claim 1, characterized in that a part is extracted from the coal, the amount of which is 7.5-25% by weight, based on the amount of extracted coal in a moisture- and ash-free state. 3. Process according to claim 1 or 2, characterized in that the extraction is carried out at a temperature above the critical temperature of the solvent. 4. Process according to any one of claims 1-3, characterized in that the complete hydrogen requirement of the catalytic hydrotreating is met by hydrogen which has been prepared via C0-shift from synthesis gas obtained during the gasification. 5. Process according to any one of claims 1-4, characterized in that the hydrocarbon synthesis is carried out using a trifunctional catalyst combination which, in addition to activity for the conversion of an H 2 / CO mixture, into mainly acyclic hydrocarbons and / or acyclic oxygen-containing hydrocarbons, as well as activity for the conversion of acyclic hydrocarbons and / or acyclic oxygen-containing hydrocarbons to mainly aromatic hydrocarbons, has C0-shift activity. Process according to claim 5, characterized in that the trifunctional catalyst combination as a component with activity for the conversion of acyclic hydrocarbons and / or acyclic oxygen-containing hydrocarbons to mainly aromatic hydrocarbons contains a crystalline metal silicate, 81 0 2 0 7 1 - 29 - '' ~ * that after an hour of calcination in air at 500 ° C has the following properties 1. thermally stable to a temperature of at least 600 ° C, 5 2) an X-ray powder diffraction pattern containing the strongest lines of the four lines listed in Table A Table A d (ü) Relative intensity 10 11.1 +0.2 ZS 10.0 + 0.2 ZS 3.84 + 0.07 S 3.72 + 0.06 S in which the letters used have the following meaning: ZS = very strong; S = * strong 3. in the formula which represents the composition of the silicate expressed in moles of the oxides and in which, in addition to oxides of hydrogen, alkali and / or alkaline earth metal and silicon, one 20 or more oxides of a trivalent metal A selected from To avoid the group formed by iron, aluminum and gallium, the SXO2 / A2O3 molar ratio (m) is more than 10. 7. Process according to claim 6, characterized in that the hydrocarbon synthesis is carried out in one step by contacting the synthesis gas with a trifunctional catalyst combination consisting of a mixture of a crystalline metal silicate as defined in claim 6 and a bifunctional catalyst which in addition to activity for the conversion of an H 2 / CO mixture to substantially acyclic hydrocarbons and / or acyclic oxygenated hydrocarbons, it has CO shift activity. 8102071 - 30 - 8. Process according to claim 5, characterized in that the two-step hydrocarbon synthesis is carried out by contacting the synthesis gas in the first step with a trifunctional catalyst combination as defined in claim 7 and carbon monoxide and hydrogen present in contacting the reaction product from the first step, if desired together with other components of this reaction product, in a second step with a cobalt-containing catalyst which has activity for the conversion of an H2 / CO mixture into mainly acyclic hydrocarbons, whereby ensure that the feed for the second step has an H2 / CO molar ratio of at least 1.5. 15 9. A method according to any one of claims 6-8, characterized in that the crystalline silicate as trivalent metal contains A, iron or aluminum and that m has a value between 20 and 400. 20 10. Process according to any one of claims 6-9, characterized in that the trifunctional catalyst combination consists of a mixture of the crystalline metal silicate and a catalyst which has activity for depositing an H2 / CO mixture into mainly methanol and / or dimethyl ether. 11. Process according to claim 10, characterized in that the trifunctional catalyst combination consists of a mixture of a crystalline metal silicate and a ZnO-Cr2O3 composition. 12. Process according to any one of claims 8-11, characterized in that in the second step of the hydrocarbon synthesis a catalyst is used which is 10-40 81 0 2 0 7 1 .- - ·> - 31 - "" contains parts by weight of cobalt and 0.25-5 parts by weight of zirconium, titanium or chromium per 100 parts by weight of silica obtained by impregnating a silicate support with one or more aqueous solutions of cobalt and zirconium salts, titanium or chromium, followed by drying the composition, calcining at 350-700 ° C and reducing at 200-350 ° C 13. A process according to any one of claims 6-12, characterized in that at least a part of the gasoline fraction obtained in the catalytic hydrotreating is mixed with at least a part of the gasoline fraction obtained in the hydrocarbon synthesis. 14. Process according to any one of claims 6-13, characterized in that at least a part of the durene is separated from the gasoline fraction obtained in the hydrocarbon synthesis and that this durene is used at least partly as an extractant for the coal and / or together with the coal extract is subjected to the catalytic hydrotreating. 15. Process according to claim 14, characterized in that at least a part of the durene is separated from the gasoline fraction obtained in the hydrocarbon synthesis, that this durene is fed to the extraction installation and that the mixture obtained during the extraction is removed. of coal extract and dureen, only part of the durene separates and recirculates the extraction plant, while the rest of the dureen is subjected to the catalytic hydrotreatment together with the coal extract. 8102071 - 32 - 16. A process for the preparation of hydrogen carbon distillates from coal substantially as described above and in particular with reference to Experiments 2 and 3 of the example. 5 17. Hydrocarbon distillates prepared from coal according to a method as described in one or more of claims 1-16. 81 0 2 0 7 1