DD158911A5 - PROCESS FOR CONVERTING COAL OR GATE IN GASOFUL HYDROCARBONS OR VIBRATING DISTILLATES - Google Patents

Abstract

The invention relates to a process for the conversion of coal, peat or wood into gaseous hydrocarbons or volatile distillates. The aim of the invention is to make the process more economical by continuously recovering the reagents used, wherein an alkali metal hydrosulfide, sulfide or polysulfide is added to the material to be processed as reagent. According to the invention, the conversion reaction takes place in the presence of water or hydrogen sulfide and optionally sulfur at 50 to 450 degrees C in one or more stages, the temperature in each stage being the same or different and the reagent being the same or different, based on its sulfur content can. The volatile liquid distillates and the gaseous hydrocarbons are recycled and / or recovered.

Description

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Conversion of coal and the like into gaseous hydrocarbons or volatile distillates

Field of application of the invention:

The invention relates to a batch process, semi-batch process or continuous process for converting coal, peat or wood into gaseous hydrocarbons or volatile distillates or mixtures thereof.

Characteristic of the known technical solutions:

AT-A-0 4030/80 discloses a process for preparing a reagent based on alkali metals and a reaction carried out by means of this reagent with the oxygen, nitrogen and sulfur in carbon. In this application, the application of this reaction to coal of various quality and to peat, which can be carried out batchwise or continuously using water and steam, and by varying the working conditions, for example the temperature, the reagent, the coal quality and the reaction stages, a mixture of said substances can be obtained. It is possible to add sulfur to stabilize the reagent in the form of a less hydrolyzed polysulfide,

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No. 140,604 describes a number of methods for preparing the reagents, stabilizing these reagents by means of hydrogen sulphide when treating carbonates with water or steam, and working in stages. It has now been found that by adding hydrogen sulfide not only the reagent can be stabilized, but surprisingly also previously unknown effects can be achieved, which are based on differences in the chemistry of coals or peat, in this regard of the carbonaceous materials of in differentiate this type of US application.

It is well known that the deposits of liquid and gaseous hydrocarbons, such as oil deposits and natural gas deposits, are being depleted so rapidly that great efforts must be made to meet the future demand for energy and raw materials for the chemical industry and a corresponding one To create replacement. One of the most accessible sources of hydrocarbons is coal, but so far there has been no opportunity for coal to be produced economically without substantial capital investment. While various methods are known for converting coal at high temperature, for example, above 600 ° C and high pressure of, for example, more than 25 bar, such as coal gasification processes, there is currently no method for converting coal into hydrocarbons, which is lower Temperature and low pressure can be performed.

In the context of the present invention, Applicants are U.S. Patents 1,300,816, 1,413,005, 1,729,943, 1,904,586, 1,938,672, 1,974,724, 2,145,657, 2,950,245, 3,112,257, 3 185 641, 3 252 774, 3 368.875, 3 354 081, 3 382 168, 3 483 119, 3 553 279, 3 565 792, 3 617 529,

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3,663,431, 3,745,109, 3,787,315, 3,788,978, 3,816,298,

3,926,775, 3,933,475, 3,944,480, 3,960,513, 3,957,503,

4,003,823, 4,007,109, 4,057,572, 4,030,893, 4,057,422, 4,078,917, 4,119,528, 4,147,611, 4,147,612, 4,155,717, 4,160,721 and 4,210,526.

In connection with the present invention, the applicant also knows the following references:

Letoffe, et al., Determination of the enthalpy of formation of the polysulfur de Potassium, Journal de Chimie Physique , 71, pp. 427 to 430, 1974,

3ohn S. Thomas and A. Rule (authors of other articles in this series are Thomas and Riding)

The Polysulfides of the Alkali Metals, Journal Chemical Soc . Part 3, p. 1063 ff., 1973,

Blitz and Wilke-Dorfurt, Z. Anorg? Chem . , 3d. 48, p. 297, 1906 (see also Ber ., 53, p. 43, 1905), van Krevelen, et al., Fuel , 38, 256, 1959, BK Mazumdar, et al., Fuel , 41, 121, 1962, Hugot, Ann. Chim Phys., 21, 72, 1900,

W. Klein, Z. Anorg. Chem., P. 241, 281, 1939, FW Bergstrom, D. Amer. Chem. Soc. , 147, 1926,

F. Feber and H. Berthold, Z. Anorg. Chem . , P. 247, 1953, Thomas and Rule, 3. Chem. Soc. , 2819, 1914, RL Erbeck, Dissert. Abstract , Ann Arbor, Mich.

3254,21, 1961,

Renegade and Costeanu, Bull, soc. Chim ., 15, 721, 19-111 Sabbaths, Ann. Chim. Phys. 22, 5, 1881, Marrony, J. Chim. Phys . , 56, 214, 221, 1959, MMe Aline Auroux, CRAcad. Soc. Paris , 274, S 1297 to 1300,

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March 1972,

Küster and Herberlein "Contributions to the Knowledge of Polysulfides" Z. anorq. Chem ., Pp. 53 to 84, Nov. 1904.

Object of the invention:

The aim of the invention is to further improve the method discussed in the aforementioned patent applications. The invention relates to the conversion of coal into various utilizable substances, wherein mainly gaseous substances or gaseous and liquid substances in varying proportion or mainly liquid material arise and the reagent is recovered and as a byproduct of the conversion process and hydrogen sulfide is obtained. The present invention also relates to the conversion of the resulting gaseous species to other distillates, and more particularly to the conversion of coal to desired conversion products such as liquid or gaseous hydrocarbons by the one-stage or multi-stage reaction of coal with a specific reagent which may be the same in the individual stages but may also be different from stage to stage, in the presence of water or steam and in the presence of hydrogen sulphide. This process is carried out at low to moderately elevated temperature and between atmospheric pressure and a pressure of less than 1.35 bar (5 psig).

Further, the present invention relates to the conversion of coal into various preselected fractions, which are either mainly gaseous or gaseous and liquid or mainly liquid, in the presence of this reagent and in the presence of water, steam and hydrogen sulfide and optionally sulfur, with recoverable Decomposition products of coal or peat have been obtained. These degradation products are either obtained primarily in a one-step reaction

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gaseous hydrocarbons or liquid hydrocarbons primarily obtained in a one-step reaction or gaseous and light liquid products obtained in a single step, being understood as meaning "low" low boiling point liquids. These products can be converted into liquid distillates in a further stage or in several further stages in the presence of various reagents and in the presence of steam and hydrogen sulphide. Finally, at high temperatures, some hydrogen is formed from coal in the presence of the reagent and in the presence of hydrogen sulphide and steam.

Explanation of the essence of the invention:

It has now been found that coal can be converted to various hydrocarbon fractions by treatment with a specific reagent in the presence of this reagent and in the presence of water and / or steam and sulfur water peat, consisting either primarily of gaseous hydrocarbons having 1 to 5 C atoms such as methane , Ethane, Athens, etc., or consist mainly of liquid distillable fractions, whereby gaseous and liquid products can also be obtained in a proportion corresponding to the practical objective and wherein also hydrogen is produced.

At higher temperatures produces a larger amount of hydrocarbons or mainly a mixture of gaseous hydrocarbons. Moreover, when another reagent is used in another reactor, the gaseous hydrocarbons may be converted to other types of hydrocarbons such as liquid or gaseous hydrocarbons in the presence of water vapor and hydrogen sulfide. It has also been found that when the reagent is replaced and when it is used

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In the case of anhydrous and eutectic mixtures of sulfides, the above phenomena will be reversed in a manner to be explained later.

It has also been found that, surprisingly, addition of hydrogen sulfide is much more favorable than the addition of sulfur described in the Applicant's earlier applications because hydrogen sulfide better stabilizes the reagent and promotes the conversion of thiosuifate or tetrathionate (and 2e) into two thiosulfate ions.

In the presence of water, K2S is partly converted to KHS, which is why both KHS and K2S should be present when hydrogenating coal in the reaction mixture. If sulfur is added, a less hydrolyzed and therefore more water resistant polysulfide such as potassium pentasulfide is also formed. Hydrogen sulfide not only improves the stabilization of the reagent but also decreases the amount of reagent required.

It has been found that if mixtures of alkali metal sulfides are used, such mixtures of alkali metal sulfides may be added to the coal to facilitate the reaction in the liquid state, for example in the form of mixtures of polysulfides or hydrates thereof.

When KgS and various polysulfides thereof react with carbon, it is preferable to attack the oxygen, sulfur and nitrogen bound in the coal and split off from the carbon components. In the presence of the reagent, of water vapor or water and of hydrogen sulfide, the conditions have been created for the splitting of various coal constituents and the elimination of oxygen, nitrogen and sulfur from water or hydrogen sulfide-derived hydrogen

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The strength of the attack may be as desired so that, depending on the reagent or reagents used and, indeed, on working conditions, essentially only gaseous reaction products or substantially only liquid reaction products or any the two extreme cases lying mixtures of reaction products are obtained.

The invention will be explained in more detail below with reference to the drawing.

Fig. 1: schematically illustrates the recovery of hydrogen sulfide from a plant for producing gaseous reaction products.

As soon as the desired working temperature has been reached in the course of the process to be explained and hydrogen sulphide or steam and hydrogen sulphide are introduced into the system, it is no longer necessary to supply an inert gas such as nitrogen or helium, by means of which the oxygen has first been flushed out of the system , Hydrogen sulfide can be supplied via the steam supply line.

In Fig. 1 is schematically illustrated how hydrogen sulfide can be recovered as a gas. A typically held at 350-390 ⁰ C reactor 22 has been beshcickt with coal, a present in a liquid form reagent present in vapor form, water and gaseous hydrogen sulfide. A cooling jacket 24 surrounding the condenser 26 facilitates the cooling of the reaction gases. The heavier products are first removed from the bottom 27 of the

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Deducted capacitor. The gaseous reaction products, usually methane or ethane, are passed on to a vessel 30 charged with water and an alkanol. The vessel 30 is supplied with water or an alkanol from the reactor if a reagent dissolved in an alkanol is used. The mixture of water and the alcohol is maintained in vessel 30 below the boiling point of the mixture so that the lighter gases having 1 to 5 C atoms as well as hydrogen sulfide pass through.

The contents of the vessel 31 is cooled to about -35 ⁰ C, whereupon the hydrocarbons with 4 and 5 carbon atoms are deposited liquid. Although most of the C. and C fractions are deposited in the vessel 31, a part thereof enters the vessel 32, where these hydrocarbons are deposited in ethanol or methanol at -3O ⁰ C together with the C, fraction become. By means of a disc-like glass frit 33, remainders of these substances, if present in the form of a mist, are removed. At this stage, only H2S and the C ^ and Cp fractions are contained in the gas stream. The gas is then introduced into a vessel containing KOH and an alcohol, usually ethanol or methanol in aqueous solution, from which the hydrogen sulphide contained in the gas recrudeses the reagent which is separated as precipitate and which consists mainly of gases of 1 and 2 C atoraene fractions continue to flow. In this way H ₂ S is recovered to at least 97 % as a reusable reagent. HgS is not blown off. The mixture of alcohol and water in the vessel 30 is used to supplement alcohol discharged from the vessel 35, but this mixture must be cooled in the heat exchanger 36.

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As already mentioned, hydrogen sulfide can be introduced into the reactor by itself or together with steam. If hydrogen sulfide is supplied without steam, its temperature is about 135 C or more, but the temperature is usually 170 to 190 ^° C when hydrogen sulfide is supplied together with steam. If a mixture of methanol and water is used to introduce the reagent into the reactor, the mixture of water and methanol is first expelled from the reactor prior to introduction into the reactor, otherwise the mixture of water and methanol will raise the temperature during distillation would hold a certain value. Hydrogen sulphide is present from the beginning of the reaction ♦

After the introduction of water vapor or of vapor and hydrogen sulphide, different lignites and subbituminous carbons, depending on their composition, show different distillation points in the production of detectable quantities of gaseous hydrocarbons.

The amount of gas produced increases significantly after reaching a temperature of 360 C, and upon reaching the lying between 380 and 45Q ⁰ C final gas at high speed, including hydrogen, is formed. When processing sub-bituminous coals, the resulting gaseous hydrocarbons may contain 4.7 % by weight of carbon oxysulfide. If hydrogen sulphide is used and all other reaction conditions remain unchanged, the resulting amount of carbonoxysulfide may be reduced.

Without being bound to a specific theory, it can be assumed that hydrogen is formed in the reactions by way of the hydrogen and hydrogen sulfide molecules.

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in ¹ W '4 «α ™'

which reacts with the coal by splitting off oxygen, sulfur or nitrogen from the coal. For the practice of the process of the invention, it appears necessary for the coal to contain oxygen, but the desired benefits can be obtained even if the coal contains organically bound sulfur or organically bound nitrogen. Higher quality coal, such as bituminous coal, is not easily convertible to gaseous hydrocarbons, but this can be achieved in a manner to be explained later, when the course of the reaction is modified accordingly.

The present invention further and preferably also relates to the gasification of lignites and subbituminous coals, but all coals can be gasified or converted into liquid products, even wood can be gasified. In addition, wood (cellulose, lignites, sugars, etc.) can be gaseous or liquid products are converted.

If 92 % carbon-containing anthracite is partially oxidized, this can also be readily converted into liquid and gaseous reaction products.

If potassium containing in the coal ash is converted to hydrosulfide, no loss of potassium hydrosulfide occurs. so that the reagent balance is extremely favorable both in discontinuous and in continuous work. Moreover, in stabilizing the reagent by means of hydrogen sulfide, the amount of reagent to be used can be reduced, and from the coal, excess sulfur and potassium, for example, for producing reagent or hydrogen sulfide, can be utilized.

It should be emphasized that sulfur, hydrogen sulfide, hydrosulfide or polysulfide are generally present

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in order to take up sulfur split off from the reagent or to take up the oxygen or sulfur formed when the oxygen is split off from the coal and thus to prevent the carbon from being dehydrated by the split-off sulfur at a temperature above 175 ° C. The various types of reagents at a temperature above 325 ⁰ C must be kept intact, because the coal would be dehydrated slowly by molten Alkalimetallhydroxyid at this temperature lying above temperatures. Since sulfur gives rise to the formation of polysulfides and alkali metal polysulfides with increasing sulfur content less prone to hydrolysis, the decomposition of the hydrolysis product, so the Hydroaulfids, by steam (or water) is avoided, but by adding 'hydrogen sulfide stabilization can be best achieved as will be explained later.

The hydrogen sulfide resulting from the addition of elemental sulfur to the alkanolic solution of an alkali metal hydrosulfide and the sulfur driven off by oxygen as the coal is converted to hydrocarbons is used to produce additional alkali metal hydrosulphide from the alkali metal hydroxide recycled to the process, but hydrogen sulfide also enters the reactor or introduced into the reactors to stabilize the reagent there, so that it can come to the hydrogen sulfide (or sulfur) is obtained in a greater amount than is needed for the reaction

Part of the potassium hydrosulfide is split hydrolytically into potassium hydroxide and hydrogen sulfide. This potassium hydroxide provides at temperatures of at least 360 C a reaction medium in which the calcium carbonate contained in the coal ash with the in the recovery

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, Ma. W <&", .Jg _- /

the reagent remaining as a residue remaining potassium sulfate to calcium sulfate and a mixture of potassium hydroxide and potassium carbonate. The potassium contained in the coal ash is also extracted in the form of the hydroxide.

As indicated above, at the temperature chosen for the reaction, which depends on the type of coal, the desired degree of decomposition of the coal and the desired reaction products, steam at this temperature is used. Water contained in the coal is also a source of water and / or steam.

As the sulfur content of the reagent increases because of the sulfur contained in the coal, because of the added elemental sulfur or because of the hydrogen sulfide, the reaction temperature is lowered. For example, a reaction temperature is reduced from 380 C to 350 C when, as is assumed for illustrative purposes, the sulfur balance indicates the presence of the theoretical compound KpS-, and this compound is maintained under the reaction conditions. As a consequence of this phenomenon, larger molecules are formed, for example, pentanes such as isopentane and pentane.

The quality of the coal also affects the boiling range of the reaction products. With increasing quality of the coal under otherwise equivalent conditions, for example when using the theoretical compound K2S-, at the same operating temperature, the proportion of liquid reaction products is higher.

Of course, as the working temperature changes, the composition of the reaction product is changed. Even if the amount of sulfur in the reagent is changed,

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As already mentioned above, the composition of the reaction product is changed.

Due to the above data, the composition of the desired reaction products by varying the temperature, by changing the S _c hwefelgehalts of the reagent by using mixtures of various reagents such as liquid or dissolved reagents, by choice coal certain quality or by recycling mixtures of distillate and Alcohol can be affected.

The above variations are within the following limits: temperature up to 425 ⁰ C and up to 450 ° C; however, the distillation begins at 40 to 50 ° C; Sulfur content in the reagent (for example potassium) KpS, but the sulfur content may increase up to KpSr, addition of sulfur or hydrogen sulfide, mixtures of these reagents, reagents in liquid or solid state.

n stood; Contacting a product stream with another mixture of reagents including hydrogen sulfide; and quality of coal (best in the range of lignites to bituminous coal). Seim processing of anthracite, the results are less advantageous although ^egg at 380 C and using a reagent such as Ko ^ a - ⁿ distillate can be obtained. Partial oxidation of a high-quality coal is also favorable.

In addition, the amount of materials to be recycled can also be changed. Thus, for example, up to a temperature of about 280 ° C, the composition of the final product in the direction of a liquid distillate having a boiling point below about 180 ⁰ C are moved. At a reaction temperature up to about 310 ⁰ C arise in the above-described recycling of alcohol into the reaction vessel Baraffindestillate. Also in this recycling must as before i / Vasser, u.zw. Steam with a temperature of about

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135 ° C (and above) and hydrogen sulfide may be present to allow an advantageous implementation of the reaction.

When the process is initiated at about room temperature (and the temperature is raised), sulfur or, preferably, hydrogen sulfide is added to the coal or reagent to adjust the sulfur selected for the reagent. Under these conditions, HpS produced in the system during the reaction of the sulfur and reagent is scrubbed out of the gas stream in the scrubbers to recover the reagent, which is illustrated by FIG. As the temperature is raised, if steam is not used, any hydrogenation of the coal will be due to the water contained in the coal or reagent. If light distillates are desired, steam may be added at about 135 ° C. However, steam is supplied at about that temperature when a hydrate of the reagent begins to reform or a lower hydrate is produced from the reagent. For a potassium based reagent, the temperature for adding steam is selected to be about 170 ^° C.

In summary, it can be seen that to the extent that oxygen and nitrogen and organically bound sulfur are split off, water, or to a lesser extent, hydrogen sulfide (which continuously evolves from water and the reagents) hydrogen to that of oxygen, sulfur or nitrogen at least for Part release liberated coal, wherein nitrogen is split off mainly in the form of ammonia and the sulfur forms an alkali metal polysulfide (for example, a potassium polysulfide) and at low temperatures with the used as a solvent: Alkenol a mercaptan. Mercaptans are absorbed by the alcohol and by the solution of KOH in the alcohol. This overall implementation is in the process of reduction

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of the hydrogen sulphide to sulfur and water, whereupon in a subsequent reaction the sulfur reacts with KOH to form potassium thiosulphate and potassium sulphide. The potassium sulfide can absorb additional sulfur from hydrogen sulfide and thereby form potassium polysulfide, with which the reagents used in the reaction are present.

The hydrocarbon mixtures, that is, the gaseous fractions obtained at different temperatures can, for example in another reactor, with a reagent of different composition, ie a reagent with higher sulfur content, and at a lower temperature of, for example, 280 to 340 ° C than in the first Stage maintained reaction temperature of 340 to 390 ⁰ C are further reacted, in the third stage, the temperature between 225 and 28C ⁰ C or 180 to 225 ° C may be (the latter, for example, in the fourth stage). Since the dehydrogenation competes with the hydrogenation in the presence of sulfur and with increasing sulfur content in the reagent, the originally gaseous reaction points are dehydrated. The resulting products may then be treated to produce a product of the desired composition, such as the desired API number. In other words, this means that the original gaseous products can be reformed to other products in line with prevailing demand.

As already mentioned, the above-mentioned process has been improved by adding hydrogen sulfide to the reagent in the hydrogenation step for coal or a coal product, thus adding alkali metal sulfides, mixtures of sulfides such as those in their hydrated form, etc. By the addition of hydrogen sulfide apparently the selected reagent stabilized so far that one with

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reaction initiated with this particular reagent or reagent mixture, with only slight deviations from one and the same starting material, with otherwise constant working conditions, gives the same products or product mixtures. With appropriate stepwise application of the reagents and choice of composition for each of the stages, by choosing appropriate temperature conditions for adding water, the process described above can be improved by adding hydrogen sulfide in such a way that a wide range of products, of selected product mixtures and a more precisely adjusted degree of hydrogenation (if desired, also when hydrogenating a product stream or product streams) is now possible.

Suitable alkali metal sulfides, mixtures of sulfides, and mixtures of the above sulfide hydrates provide the desired stability of the reagent and the desired product with hydrogen sulfide. When the reagent is suitably maintained in an "active" state by addition of hydrogen sulfide, there is the advantage of reducing the amount of reagent required, the advantage of higher yields, and the advantage of being more susceptible to the nature of the resulting end product.

The reason for the addition of hydrogen sulfide is given by the following reaction equation:

1. 4K0H + 4H ₂ S ^ 4KHS + 4H ₂ O

If sulfur derived from coal is present, the reaction will proceed

2. 4S ₊ 6KOH ^ ^K 2 ^S 2 ° 3 ^{+ 21 <} 2 ^{S + 3H} 2 °

down, whereupon the reaction

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3. i <2 ^S 2 ° 3 ^{+ 3H} 2 ^S '^ ^K 2 ^S 5 ^{+ 3H} 2 °

follows. The decomposition of K ₃ S ₂ proceeds according to the reaction equation

4. 4K ₂ S ₂ + 8H ₂ O £ 4 + KOH 4KHS + 4S +

Thus, if H ₂ S is present, KOH is converted to KHS and if KOH reacts with thiosulfate, the thiosulfate is converted to K ₂ Sc.

Further reactions follow the equations

5. K ₂ S ₅ ^ K ₂ S ₄ + S (above 300 ^° C.)

6. K ₂ S ₄ ^ K ₂ S ₃ + S (above 460 ° C)

7. KHS + K ₀ S + 3H _o 0 ^ 3K0H + 2HS

2 2 - * 2

8. K ₂ S + H ₂ O KOH + KHS

9. KHS + H ₂ O> H ₂ S + KOH

10. KHS + KOH ^ K ₂ S. XH ₂ O

depending on the temperature, for example, 2, 5, etc. may stand. Thus, there should be enough H ₂ S to adjust the reactions according to the law of mass action so that the reagent is stable, that is, sulfur released from the coal or reagent is taken up and hydrogen sulfide prevents the reagent from hydrolysis. In addition, the desired K ₂ Sc is regenerated from the thiosulfate formed due to the oxygen present in the coal during the reaction. The reagent is thus held by H ₂ S in the desired state of hydrolysis.

Of the various reagents are KHS, NaHS, KpS, K ₂ S ₂ and K ₂ S ₃ and of these in particular K ₂ S ₀ , KpS and

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K _o Sr in the order given preferred because of their stability and their ability to absorb sulfur. The other sulfides, such as Na ₂ S ₂ at 445 ° C or NapS ₄ at 275 ⁰ C at the melting point inadequate stability or release sulfur at 760 mm Hg, such as 1 < ₂ S5 at 300 ⁰ C, which to K ₂ S ₄ ^{+ s} decays, or I < ₂ S4 at 460 ⁰ C, which decays to K ₂ S ₃ + S, or i <2 ^S 3 ^Dei 780 ⁰ C, which decays to K ₂ S ₂ + S.

The melting points of the above alkali metal sulfides are the following: K ₂ S at 948 ⁰ C, K ₂ S ₂ at 470 ⁰ C, K ₃ S ₃ at 279 ⁰ C (solidification point), K ₃ S ₄ at 145 ° C, K ₂ S ₅ at 206 ⁰ C, I < ₂ ^S 5 at 190 C. The melting points of eutectic mixtures of various sulfides are as follows: for KpS + ^K p ^ 2 ^Dei ^^ ^ 'for K ₂ S ₂ + K ₂ S ₃ at 225 ° C, for K ₃ S ₃ + K ₃ S ₄ at about HO ⁰ C, for K ₂ S ₄ + KpSr- at 183 C. Due to the above various explanations, the appropriate temperature conditions corresponding to the decomposition temperature and / or the melting point in such A way that a solid reagent or a stable liquid reagent can be used to coat the coal. Of course, the various hydrates of the alkali metal sulfides have different melting points and / or different decomposition points, which of course also applies to the eutectic mixtures. The suitable transformation temperatures can be determined in a conventional manner by thermal analysis.

The conversion of coal by the process of the present invention proceeds without the reagent exhibiting instability, that is without an alkali metal sulfide hydrate being unstable, because hydrogenation of the carbon preferentially precludes decomposition of the reagent and stabilizes the reagent by the addition of hydrogen sulfide becomes. In addition, the addition of hydrogen sulfide also increases the amount of reagent required

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since this is now in a more stable form, so that the reaction of the coal can proceed in the presence of an adequate amount of reagent and the process is also improved in this respect. Under otherwise constant conditions, the use of hydrogen sulphide at least doubles the output of desired product.

Hydrogen sulfide is usually in an amount of about 10 ml / min. 1 to 30 ml / min.1 fed reactor contents, wherein usually the amount supplied is about 20 ml / min.1 reactor content. Expressed on a different basis, 0.5 gol (gramol) or less of H £ S is added per 1000 ml of water split off during hydrogenation. With regard to the various sulfides and their decomposition temperatures and the associated reactions, reference is made to US Pat. No. 4,210 to the patent owner.

At the maximum operating temperature of, for example, 450 ° C. in question, 1 .gtoreq.-2 sulfur gives rise to sulfur, which, as already explained, is favorable in connection with the dehydrogenation of further process streams. As the decomposition temperatures decrease with decreasing pressure, conversion of the coal at atmospheric pressure is quite feasible, although some advantages can be obtained when working at higher pressures, for example when operating at pressures above 5 bar (6 bar), but the additional costs and further expenses make this mode of implementation of the coal conversion process less desirable. For practical reasons, therefore, the pressure is selected between about 0.5 bar and about 5 bar (about 1.5 bar to about 6 bar), but it is preferably carried out at atmospheric pressure.

While the coal and reagent reaction mixture can be conveniently stirred, it is best

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pre-coat the coal in the absence of oxygen since oxygen tends to destroy the reagent.

For this reason, it has proven useful to use a liquid or a dissolved reagent. Liquid yet stable reagents can be used to coat carbon at the melting point or above the melting point of the selected reagent or liquid eutectic mixture of reagents.

For example, a mixture of KpS ₃ and K ₂ S. at a temperature above 11 ° C. in the liquid state can be used to coat coals. As a solvent for the above reagent, glycerin has been found to be very useful. Any solvent which dissolves the sulfides and does not interfere with their action can be used. About 88 g of KHS can be dissolved in enough glycerol to give a solution with a total volume of 200 ml. When this mixture is heated to 175OC (glycerol decomposes above 190 ⁰ C), is stripped from the solution of KHS H2O, so that the resulting mixture then KPS. Contains XH2O. Oxygen is also kept away from this reaction mixture. The resulting mixture can then be used directly to coat coal and thus serve as a reagent.

Since the intensity of the attack on sulfur, nitrogen and oxygen contained in the coal is a function of the composition of the reagent and its amount, the following points should be pointed out. Coal is then converted into gaseous conversion products when the coal is heavily degraded, that is, when the reagent is very strong on the coal. With a slightly less extensive mining of coal more volatile distillates are obtained. At 175 ⁰ C, sulfur begins to dehydrate the coal, which is why the presence of sulfur to convert the coal

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Coal is not wanted. Under such conditions, therefore, a stable reagent is used. However, in reforming, ie, in the dehydrogenation and subsequent reaction of dehydrogenation products with each other, this reaction is important because it allows to obtain liquid products of different boiling points (or preselected API number). Of course, gases produced from coal are ideal starting materials for reforming, hydrocarbon. As mentioned above, the reactions are also influenced by the quality of the coal. When processing lower quality coal, high sulfur content reagents are used to achieve the least possible degradation. For a more complete gasification, the amount of sulfur in the reagent is reduced, eg K2S is used, whereas for a less extensive attack the coal i <2S5 is used. This is especially true for peat which, when reacted with KpS ₅ , essentially gave naphthalene.

EXEMPLARY EMBODIMENTS:

The method according to the invention is explained in more detail below by means of non-limiting embodiments of the invention.

example 1

A reaction vessel of 3.785 liter capacity equipped with a steam supply line, a heating and cooling device, a thermocouple, a stirrer and a reaction gas outlet line was charged with hydrogen sulfide and with steam, which can also be supplied separately. The products were separated in a suitably cooled condenser while the gases were collected in the manner already described in connection with the figure.

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To 800 grams of Kentucky Charcoal Coal (# 9) described in the described vessel, "was added a liquid mixture of KpS and KpS 5B ₂ O. The amount of reagent added was 2 moles, or 1 One mole of K ₂ S ₃ * was obtained from a solution of K ₂ S and Kp ^ 5. Further, 4 g of KOH was added which was used to quench NH 3 under operating conditions was stirred to coat the carbon particles with the reagent.

₂ S was then supplied in an amount of 80 ml / min at a temperature of 5O ⁰ C steam together with H. The reaction was exothermic, but the reaction temperature was not above 45O ⁰ C allowed to rise, but is held as close as possible between about 350 and 390 C. Steam was fed at a temperature of 135 ^° C. at a rate equivalent to the withdrawn amount of hydrocarbons or at 1.3 times this rate. The product obtained was a pale red clear solution which completely distilled on treatment under the same conditions with Γ9 g KHS to 240 ° C and thereby provided a water-bright distillate of liquid hydrocarbons, which had about the viscosity of water (almost water-clear hydrocarbon). In total, 324 ml of distillate and 12 liters (under standard conditions) of a gas derived from the first reaction stage were obtained.

boiling analysis

Initial boiling point

^§ 248.9 C 248.3 ° C 252.2 ° C 255.6 ° C 260.0 ⁰ C 264.4 ⁰ C 2 / C ⁰ 2.2

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82 2 ° C 10 0 / / 0 20 0 / / D 30 0 / / 0 40 % 50 % 60 0 / / 0 70 C /

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Column analysis 82.2 ⁰ C onset of boiling

80 % 281.1 ⁰ C

90 %

95 % 311.1 ⁰ C

98.6 % 333.3 ° C

(1.4 % residue - heavy liquid) Example 2

To demonstrate the effectiveness of adding HpS, 110 g of a bituminous coal (calculated as dry and ashless coal) was treated with solid NaHS (technically pure) or with KHS (dissolved in water) in the reaction vessel described above with addition of H 2 S in reacted in an amount of 80 ml / min and with the addition of 200 ml of helium. Steam was at a temperature of more than 137 C with 1.3 times that

Feed rate at which hydrocarbons were removed as condensate. By adding KOH, ammonia was driven off, thereby preventing ammonia from reacting within the reactor. The reaction was exothermic at 39O ⁰ C. Even before the reaction was exothermic above 39O ⁰ C, 252 1 of gas and 70 ml of liquid hydrocarbons were collected as condensate.

If experiments with and without addition of HpS were carried out with lignite, more than doubled yields were obtained when working with an addition of HgS. Furthermore, the reagent used was that used according to Example 1, wherein also in this case the reaction above 390 ⁰ C was exothermic.

It requires about 3 moles of HpS per mole of KpSpO _{3 produced} . For 1 mole of KpSpO formed, about 48 g are precipitated

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/ JJ

Coal-derived oxygen is consumed.

Wood contains about 42 % oxygen and anthracite contains about 2 % oxygen. Between these limits, H ₂ S is added as a maximum, based on the above implementation, as other competing reactions occur. The above information is intended as a rough indication of the required amount of HpS, but in practice, for example, because is leading to water main running side reaction of molecular hydrogen with oxygen, requires lower amounts of HpS.

If KHS and / or NaHS are used, become rich. Liehe amounts of gas obtained, the reaction is above 390 C exothermic. Using K "Sp.5H _o 0 + KpS (empirically calculated on the basis of equimolar amounts of XpS.5H ₂ O and K ₀ S-), only a small amount of gas and a considerable amount of liquid condensate are obtained from the same starting material However, although the implementation of Seginn, u.zw. from 50 C expires exothermically and appears to be self-sustaining at 330 ° C with little heat input, K ^ S ₂ (obtained from a melt of KpS.5HpO + S) and mixed with the same amount of KpS (prepared from a hot, aqueous Solution of KOH and sulfur in the ratio of 6 KCH + 4 S) gives, when used as reagent, a liquid distillate and gas. Using the same starting material, the reaction becomes exothermic at 240 ° C. In all three cases, the starting material was a bituminous coal (# 9) from Kentucky, which had a grain size of less than 200 mesh, always the other reaction conditions were identical, ie steam, H ₂ S and helium used in the manner described above were. The above examples show that it is possible to produce either only gas or gas and distillates of essentially only distillates and that the exothermic reactions take place extremely well.

- 25 -

During these exothermic reactions only negligible amounts of CO and COp were formed. Hydrogen sulphide was not detectable in the scrubbed exhaust gases. COS is obviously not formed,

The above is further explained by the following example

Example 3

Charcoal from Kentucky (# 9) was used along with the following reagent

(1) K ₂ S.5H ₂ O + S

theoretically

K ₂ S ₂

(K ₂ S + K ₂ S ₅ )

(2) Two layers (4S). (0.83)

+ 6K0H (watery)

For the preparation of the reagent, 0.5 mol of each of the above products (1 and 2) was used.

The coal had the following composition:

Table I Untreated Coal (# 9) from Kentucky

as-delivered dry ash analysis

in% in %

Moisture 2.58 - SiO ₂ 54.15 %

Ash 8,52 8,75 Al ₀ O. 24,79 %

Volatile substances 35,35 ό6,90 Fs _? 0 ₃ 13.72 %

bound carbon

53.54 54.95 TiO ₂ 1.69%

- 26 -

L · & _ * J : '- -Jm

' ¹ J> *) · 7

I

sulfur 2.62 2 II , 69 CaO 17 0 "7 O C / 77 ^c / KWh / kg 8.356 8th , 577 MgO , 716 0 KWh / l (no-mark) - 9 399 Na ₂ O 149 0 T3C 0 / carbon 71.50 73 50 K ₂ O , 62 2 »44% hydrogen 4.87 5 00 Li ₂ O 19 135 ppm nitrogen 1.59 1 , 63 P ₂ O ₅ 17 0 oxygen 3.22 8th , 43 19 0 table , 83 After Implementation won Product: Grade API at 15.55 ⁰ C 15.9 spec. Mass at 15 , 55 ⁰ C 0.9530 g / ml Sulfur % 0 KWh / kg 11 KWh / l 11 carbon 88 hydrogen 10 O λ ^ WfQ f oil 0 nitrogen 0 oxygen 0

Table III

Boiling analysis of the product according to Table II

Initial boiling point 172.2 ° C

5 % spreading 226.7 ⁰ C

10 % spreading 252.2 ⁰ C

20 % spreading 255.6 ° C

30 % spreading 265.5 ° C

40 % spreading 275.6 ⁰ C

50 % spreading 281.1 ° C

60 % output 284.4 ⁰ C

70 % spreading 303.3 ° C

80 % spreading 321.1 ° C

90 % spreading 354.4 ⁰ C

95 % spreading 375.7 ⁰ C

227

Endpoint % gained % Backlog % Loss

96.0 3.7 0.3

376.7 ^U C

Table IV

analysis of Distillates (until table 50 % It. Sied V Grade API at 15 55 ⁰ C 20.9 spec. Dimensions at 15.55 ⁰ C 0.9287 g / ml Sulfur % 0.15 KWh / kg 12.059 KVVh / 1 11.183 carbon 87.17 hydrogen 10.08 sulfur 0.15 nitrogen 0.18 oxygen 2.42

Analysis of the distillate (from 50 % to endpoint It

boiling analysis)

Grade API at 15.55 ⁰ C spec. Mass at 15.55 C sulfur % KWh / kg KWh / l

Carbon hydrogen sulfur nitrogen oxygen

16.4 0.9568 0.14 11.935 11.436 90.45 % 8.47 % 0.14 % 0.31 % 0.63 %

Example 3 above typically illustrates coal upgrading and conversion to liquid products.

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7 7 Μ V 7, JL £ «J L · $ L

- 28 - £ L Ό L · L · / y

It has been shown above that coal can easily be made into a large number of hydrocarbons by a very versatile and low pressure, low pressure, and under certain conditions exothermic process.

- 29 -

Claims (23)

9 o 7 invention claim A batch process, semi-batch process or continuous process for converting coal, peat or wood into gaseous hydrocarbons or volatile distillates or mixtures thereof by reacting coal, peat or wood and, as a reagent, a hydrosulfide, a sulfide or a polysulfide of an alkali metal or mixtures thereof characterized in that the conversion reaction in the presence of water or hydrogen sulfide and optionally sulfur is carried out at a temperature of 50-450 ⁰ C in one stage or in several stages, whereby the temperature may be the same or different in each stage and the reagent the same or, based on its sulfur content, may be different, and that the volatile liquid distillates and the gaseous hydrocarbons are recycled and / or recovered. Process according to item 1, characterized in that the reagent used is an alkanoic solution of an alkali metal hydroxides, a sulphide, a polysulphide or mixtures thereof, in that the conversion is carried out at a temperature of 50 C and above in the presence of water in the form of water of hydration, water or Steam is carried out in the presence of hydrogen sulphide and continued in one stage or in several stages at a temperature up to 450 ⁰ C, wherein in each stage the temperature can be the same and the reagent the same or, based on the sulfur content of the reagent, different may be, and that this reaction is continued exothermic at least in the first stage and the volatile liquid distillates and gaseous hydrocarbons are recovered. - 30 - 3. The method according to item 2, characterized in that elemental sulfur is added to an alkanolic solution of the alkali metal hydrosulfide. 4. The method according to item 2, characterized in that potassium hydrosulfide is used as alkali metal hydrosulfide, 5. The method according to item 2, characterized in that is used as the alkali metal sulfide sodium hydrosulfide. 6. The method according to item 2, characterized in that a mixture of rubidium, kaiium and sodium hydrosulfides and sulfides is used as the alkali metal hydrosulfide. 7. The method according to item 2, characterized in that hydrogen sulfide is recovered. 3. The method according to item 2, characterized in that lignite coal is used as coal. 9. The method according to item 2, characterized in that is used as a coal sublignite. 10, method according to item 2, characterized in that is used as coal anthracite, especially partially oxidized anthracite, bituminous coal or subbituminous coal ♦ 11 .. Method according to item 2, characterized in that peat is reacted. 12. The method according to item 2, characterized in that the alkali metal is potassium. 13 ', method according to item 2, characterized in that the distillate in another stage in the presence of - 31 - 1.1 a L £ / Hydrogen is reacted in a reagent of higher sulfur content. 14. The method according to item 2, characterized in that the reaction is carried out at a temperature between 135 and 450 ⁰ C. 15. The method according to item 14, characterized in that the reaction in
is taken Implementation at a temperature between 170 and 380 C 16. The method according to item 1, characterized in that in a continuous process coal, peat or wood, coated with reagent, is continuously introduced into a maintained at a temperature above 5O ⁰ C and at a temperature up to 450 ⁰ C reaction zone, said the coal, peat or wood is treated to remove atmospheric oxygen, and that the reagent used is a hydrosulfide, a sulfide or a polysulfide of an alkali metal or various alkali metals and mixtures of hydrosulfides, sulfides and polysulfides thereof in such a manner that the carbon peat or wood is coated » that hydrogen sulphide, water or steam is introduced in at least one reaction zone at a temperature between 160 C and up to 450 ⁰ C, the coal, peat or wood or decomposition products thereof in at least one zone at a predetermined temperature and composition of the reagent being continuously mixed with (1) a predetermined reagent based on its sulfur content, hydrate form or melting points, or (2) Mixtures of such reagents is reacted in the presence of the supplied water, steam or hydrogen sulfide, that volatile and / or gaseous products are withdrawn from the reaction zone, - 32 - hydrogen sulfide is withdrawn from the reaction zone, that the ash of coal, peat or wood is removed from the reaction zone, that unreacted reagent contained in the ash of coal, peat or wood and alkali metal compounds contained therein are recovered as alkali metal hydroxides, that the alkali metal hydroxides are reacted with at least a portion of the hydrogen sulfide split off during the reaction to recover the reagent and hydrogen sulfide is recovered to supply it to the reaction and that a sufficient amount of regressed reagent is introduced into the reaction zone to continue the reaction of the coal, peat or wood or decomposition products thereof. 17. The method according to item 16, characterized in that a first reaction zone is maintained at a set, predetermined temperature wiid to produce gaseous hydrocarbons. 18. The method according to item 16, characterized in that the reaction zone is maintained at a suitable temperature for obtaining a predetermined fraction of liquid hydrocarbons. 19. The method according to item 17, characterized in that the gaseous hydrocarbon is treated in a second reaction zone for the production of liquid distillates with a different type of reagent. 20. The method according to item 17, characterized in that lignitic coal is used as the coal to be converted. - 33 - 9? ? 7 * J dm am f 21. The method according to item 17, characterized in that the reagent used is potassium sulfide, a potassium polysulfide, potassium hydrosulfide or hydrates thereof or a mixture thereof. 22. The method according to item 17, characterized in that the reaction is exothermic in a first reaction zone. 23. The method of item 17, characterized in that 'the temperature in this reaction zone in steps between ⁰ and 450 C. 24. The method according to item 17, characterized in that the present in liquid form or in Fprrn a gas hydrocarbon product in separate stages with the reagent based on alkali metals with increasing sulfur content of the reagent in discrete, decreasing temperature ranges below 400 ⁰ C ,; is set 400 ^° C., but at a temperature above 100 ° C. 25. The method according to item 24, characterized in that the gaseous hydrocarbon is washed in an alkali metal hydroxide solution and thereby hydrogen sulfide is removed from the gaseous hydrocarbon as a reaction product with the alkali metal and the reagent for the purpose of recycling the same is recovered. 26. The method according to item 17, characterized in that as a reagent, based on the material balance, one of the theoretical composition K0S3 is used. 27. Method according to item 17, characterized in that anthracite or (partially) oxidised anthracite is reacted with the reagent « - 34 - Hier2u