DE2167259C2 - Process for the pyrolysis of carbonaceous materials - Google Patents

Description

S- + 2O ₂ - SO ₄ and SO ₄ - + 2C -3- + 2CO ₂ .

30th

and thereby the melt is etched and the hot melt from the hot melt zone is returned to the pyrolysis reaction zone.

3. The method according to claim 2, characterized in that the reaction according to (1) and (2) im same part of the heat generating zone takes place

4. The method according to claim 2, characterized in that the carbonization products with water steam and some of the coal products in carbon and hydrogen is converted.

5. The method according to claim 1, characterized in that the pyrolysis reaction zone is kept at a temperature of 400 ° C to 1100 ⁰ C and usable products, including coke, are formed; that the usable hydrocarbons are separated; that the coke-containing melt is withdrawn from the conversion zone; that the withdrawn melt and coke are contacted with a reactive form of oxygen in a heat generating zone and thereby the withdrawn melt is heated; and that this heated melt from the heat diffusion zone is returned to the pyrolysis reaction zone.

6. The method according to claim 5, characterized in that the melt about 05 to about 7 Contains% by weight of metal ions.

7. The method according to claim 5 or 6, characterized in that additional charging with coke is given in this heat generating zone.

8. The method according to any one of claims 5 to 7, characterized in that the melt has a Contains catalyst

9. The method according to any one of claims I to 8, characterized in that the molten salt The invention relates to a method for pyrolysing carbonaceous materials which brought into contact with a molten body of salt and converted into polyrolysis products The molten salt containing the coal products with a source of reactive oxygen is contacted in order to generate sufficient heat in the melt and the pyrolysis reaction in the Maintain pyrolysis reaction zone.

In the conventional process for generating heat by burning carbonaceous materials, oxidation is usually carried out directly with air according to FIG equation

C + O ₂ - CO ₂ + heat.

In this way, millions of tons of carbonaceous fuels are burned annually for heat for the generation of electrical energy as well as for industrial and residential heating. Size Amounts of poor quality carbonaceous materials are also used in waste disposal burned in incinerator In order to increase the combustion efficiency of certain fuels, numerous improvements have been made, including improvements in the design of the incinerators and the combustion conditions. The combustion of heating oil and heating gases is also significant has been optimized.

It is known to convert carbonaceous materials pyrolytically by heating in the absence of oxygen into valuable materials, these products depending on the carbonaceous starting material and on the pyrolysis conditions. In the conventional pyrolysis process, the material is brought into a reactor, the outer surface of which is heated. You can work both in batches and in a continuous flow. In some cases, some of the carbonaceous material or pyrolysis products are burned externally to generate heat for the remainder of the system. If these processes are mainly geared towards the extraction of by-products, conventional sources, such as coal, wood, are used as starting materials. Oil and lignite. A general disadvantage of this combustion process is that, as a result of the impurities in the fuel or because of the special combustion method, undesired products such as CO, SO ₂ . SO ₅ . NO and NO ₂ arise. In order to prevent release of these unwanted by-products into the atmosphere, is either limited to the use of fuels to those with a low content of impurities or contaminants must be removed prior to combustion or the impurities generated during combustion must be removed from the exhaust gas . In many cases, these additional steps have proven impractical or uneconomical.

Pyrolysis of carbonaceous materials has also been considered in solid waste processing. However, the techniques used for this purpose have various disadvantages.

When using a JiTsnen flame = as a heat source the process suffers from poor heat transfer to the material to be pyrolyzed Another disadvantage is that in the known method, considerable amounts of air pollutants in the form are formed by by-products, and these Pyrolysega'e affect the economy deniruge! Procedure in a very special way.

It is known that alkali sulfates by reducing agents can be converted to Alknüsulfiden. In turn, alkali sulfides can be oxidized. However, from the prior art is so far no process has become known which combines these reactions in such a way that they become one complement the cyclical heat generation process. The technique of working in molten salts has become popular in the have made great strides in recent years because of their stability and wide melting range Molten salt found diverse applications. For example, in an alkali carbonate melt Sulfur oxides from furnace exhaust gases absorbed In the process of DE-PS 4 93 475, the degassing and Gasification of fuels in a molten pool is effected by heating this molten pool to such an extent that that the volatile constituents of the fuels are driven off. This procedure is suitable especially for inferior fuels such as raw lignite, oil shale and washing mountains. The melt is expediently prepared in a heated furnace serving as a melting chamber and then in a Reaction chamber brought into contact with the fuels to be degassed before returning to the melting chamber should completely remove the contaminated melt from the distillation and reaction residues to be freed. DE-PS 3 23 595 discloses a process for the carbonization of cellulose and peat materials under pressure and heat treatment in the presence of more or less viscous masses, such as Tar oils, petroleum oils. Mercury. Salt solutions and melts are known to be temperatures in the range from 360 to 3Γ 3 ° C are used.

Attempts have also been made using alkali carbonate or alkali hydroxide melts Gasifying coal. Materials containing carbon have been treated with the molten salts by carbonaceous solids and water vapor with a melt of an alkali compound under Conditions were contacted in which a hydrogen-rich gas is present in addition to a coalification product formed. By burning the coal products with air, heat could also be generated, whereby the underlying heat generation reaction in the direct combustion of carbon plus oxygen to carbon dioxide existed.

Conventional cracking processes such as coking are used in oil refining. Cracking. Dehydrogenation and catalytic cracking often result in excessive coke formation, inferior products and sulfur-containing gases in the refinery gas. In addition, this process produces very high sulfur cokes which are generally not particularly valuable. During catalytic cracking, not only are coke accumulations formed, but the catalyst and heat exchange are also adversely affected; the systems required for this are therefore constructed in a rather complicated manner and make the processes considerably more expensive. Hydrochemical conversion processes with hydrogen are the well-known hydrocracking and hydrogenating desulfurization (hydrotreatment), which processes usually require considerable capital expenditure and often cannot meet current and future standards, especially when desulfurizing heavy oils and residues. It is known that molten zinc chloride is an effective catalyst for the hydrocracking of polynuclear hydrocarbons, but zinc chloride is deactivated by sulfur and ammonia by forming zinc sulfide and ammonates. In addition, the regeneration of the catalyst requires combustion with simultaneous volatilization of the zinc chloride, which must then be recovered; another method of catalysis Torregeneration consists in the dissolution of the catalyst in a two-phase system of water and organic substances. The first form of regeneration is through the hydrolysis of zinc chloride vapors in the presence of water vapor to form hydrochloric acid and zinc oxide because the salt? ^- -re are recovered and the zinc oxide must be converted back to zinc chloride at low temperatures. Another additional by-product is sulfur dioxide, which has to be captured and reduced to produce sulfur. These process steps are complicated and require energy.

Carbonate melts have already been used to crack light hydrocarbons such as ethane been; an extension of this technology to the use of sulphide-containing melts and to the hydrocracking, the coking of residues and the internal heating due to cyclical reactions however, this has not yet been taken into account by the technology, presumably also because one saw no way of removing the sulfur from the melt in an economical manner.

The invention is based on the object of a practicable and generally applicable method for To create pyrolysis of carbonaceous materials, which leads to the recovery of carbonaceous fuels, Especially of coal, on a large scale suitable isi and a heat generation allowed, thereby however, avoids the formation of undesirable by-products in the exhaust gas and therefore in a simple manner and without subsequent connection of time-consuming and energy-consuming cleaning, preparation or regeneration stages gets by.

To solve this problem, the method specified in claim 1 is proposed, which is characterized in that it is mixed with a molten salt of 1 to 25% by weight of sulfur in the form of sulfides and / or sulfates operates and in the pyrolysis reaction zone maintains a temperature of 400 to 1300 ° C.

The method according to the invention causes! the pyrolysis carbonaceous materials and at the same time the generation of heat in two cyclical reactions, which the carbonaceous material in contact with a salt melt with the formation of pyrolysis products verb-alsoen; in the process according to the invention, the molten salt is internally produced by chemical means Reactions heated up. In addition, the reaction of a sulphide-containing melt with a reactive form of oxygen generates heat for external use, while the corresponding suIf at in Contact with the carbonaceous material is converted in turn to the sulfide form. The inventive

Proper process is based on a variety of carbonaceous Materials applicable, including common heating and fuel, as well as carbonaceous waste. The process is therefore particularly suitable for waste recycling and simultaneous heat generation.

The method according to the invention is therefore also a Process for generating heat. It is based on a two-step process, the first being the The conversion of a sulphide melt with oxygen to a sulphate melt and usable heat, while in the second step the sulfide by treating the molten sulfate with a carbon material is regenerated. On the other hand, and under another aspect, is the method according to the invention a very efficient method of pyrolysing carbon materials by using them that contain carbon Materials with a sulphate- and / or sulphide-containing hot melt at pyrolysis temperatures and below non-oxidizing conditions are brought into contact with carbonic products and valuable Exhaust gases are obtained. The coal products are then oxidized by reacting with the sulphate, and the sulphide which forms is regenerated to sulphate by reaction with oxygen (air), while the This significantly increases the temperature of the melt.

The inventive method has particular application to a number of methods for Petroleum refining, in which the starting materials with a sulphide-containing alkali melt, preferably one sulphide-containing alkali carbonate melt, are brought into contact under suitable working conditions. This process can be carried out with or without a catalyst and with or without a supply of hydrogen. the Heat is obtained for these conversion reactions. by the coke-containing melt with a source reactive oxygen, such as air, is brought into contact. In addition, it is possible through suitable Treatment to remove accumulations of sulphurous compounds. The applicability of the The process of the invention extends to the conversion of partially refined petroleum products, such as the conversion of distillation residues into valuable products through heat cracking, Coking, catalytic cracking, hydrocracking, hydrogenation, dehydration or desulphurisation with hydrotreatment, this process of hydrocarbon conversion being particularly preferred in a sulfide-containing one Run alkali carbonate melt. Especially the use of batch melts to crack Hydrocarbons using zinc chloride as a catalyst for the hydrocracking experience the use of the method according to the invention is a particularly advantageous embodiment.

By using a molten salt, the carbonaceous raw material is snowed! on the corresponding pyrolysis temperatures of 400 to 1300 ° C, so that larger amounts of usable high-quality gaseous by-products arise and also the throughput per unit is increased significantly.

F i g. 1 schematically shows a simplified flow diagram a preferred embodiment of the method according to the invention;

2 shows schematically a preferred reactor system for heat generation according to the method according to the invention;

Fig. J to 5 / own special ·. ¹ \ usbildungcii d '> erfindungsgemäOen method in which the heat generated is used for the pyrolysis of carbonaceous products.

F i g. 3 is a schematic representation of a rs Flow chart with the main steps these. «· Aspect of the present invention;

4 is a schematic representation of a preferred reactor for reheating the melt for pyrolysis applications:

Fig. 5 is a diagram showing the after present invention identifies achievable rapid pyrolysis;

Figures 6 and 7 show an aspect of the present invention Invention according to which the heat generated is used to convert hydrocarbons;

F i g. 6 shows a schematic flow diagram with the essential steps of the hydrocarbon conversion according to the present invention;

F i g. 7 schematically shows a preferred ¹⁷ OnTi of a reactor for reheating the melt for the hydrocarbon conversion.

The generation of heat

The mode of operation of the present invention can generally be illustrated with the following reactions:

M ₂ S + 2 O ₂ -M, SO ₄
M.:O ₄ + 2C-M ₂ S + 2CO ₂

in which M = Na, Li, K or their mixtures. Although equation (2) indicates carbon as a reactant, any of the common fuels or the decomposition products of common fuels can also take part in the reaction (for example

CH ₄ + M ₂ SO ₄ - M ₂ S + CO ₂ + 2 H ₂ O).

Reaction (1) is very exothermic, reaction (2) is endothermic. Together, reactions (1) and (2) cause the same amount of heat to be released as in the conventional oxidation of carbon to carbon dioxide. The heat transfer is much easier than with conventional carbon combustion due to the higher heat transfer rates in the molten salts. In order to be able to carry out these reactions, the temperature for reaction (1) should be above 30O ⁰ C and for reaction (2) above 60O ⁰ C and preferably for both reactions between 800 ⁰ C and 1200 ° C; these values are well below the working temperatures of most ovens and boilers. The reactions can be carried out at any practical pressure; at increased pressure, however, the volume throughput of the gases through the molten salt decreases.

Since the reactions are cyclical, the melt does not only need alkali metal sulfides or sulfates contain. Rather, it preferably consists mainly of other salts that serve as a carrier or reaction medium to serve. These salts must be used with the alkali metal sulfides and sulfates at working temperatures be compatible. A preferred class of salts are the alkali metal carbonates.

It is important that the melt has a sulfur content of about 1 to 25% by weight, preferably 2 to 10% by weight, based on sulfur. The amount should be sufficient to ensure that reaction (1) and ( 2) run preferentially over the reaction C + O ₂ -CO ₂ . In other words: Im

Mechanism of reaction (2) should essentially consume all of the carbon.

Any reactive oxygen source can be used which is compatible with the melt and the reactants; the preferred form of oxygen is air. If you continue to carry out reactions (1) and (2) at the same time while all of the editorial staff are in intimate contact with one another, the carbon is preferably used in excess, so that in the state of equilibrium the reaction (2) is favored and the silicon sulfur is present in the melt as a sulfide. Numerous forms of fuel-containing substances can be used as reducing agents in this process. All common forms of carbonaceous fuels can be used - including natural gas, coke, coal, fuel oils, petroleum residues, lignite, peat, and wood. Furthermore, you can use the specified procedure 3UCh Numerous? Ab ^ lUtnffp vprwp.nrlpn. rlip Ηργ conventional combustion cannot be directly fed. For example, urban waste such as polyvinyl chloride, wood, rubber, plastic, waste automotive oil or waste from food processing, as well as agricultural waste including animal and human waste, can be used.

In addition to a carbonaceous reducing agent and a reactive oxygen form, it can at times it may be desirable to use a catalyst for the reduction reaction; this has become Iron proved to be well suited. It can therefore contain an amount of about 0.5 to about 7% by weight of the Melt are used. The iron can be elemental or in the form of ferrous compounds like Iron sulfide or iron sulfate can be added, which are compatible with the other constituents of the melt are.

The F i g. 1 shows a preferred embodiment of the invention. For better representation, the Composition of the melt of sodium as a cation are explained. As already mentioned, however, the Melt also contain other metal ions. In FIG. 1, reference numeral 10 denotes a conventional one carbonaceous fuel such as coal or heating oil. The fuel 10 is a furnace or Reactor 12 fed. The construction of the same in each individual case should have an intimate contact between the carbonaceous raw material and the sulphate in the melt. A source Edible oxygen 14, such as air, is also supplied to furnace 12. The air can be fed in at the bottom of the reactor zone so that it rises upwards through the melt and as a result, the oxygen and the sulfide are intimately mixed. In the drawing, 16 denotes the withdrawal the product heat. Normally, heat is dissipated by means of indirect heat exchange. For example, if the heat for producing high-pressure steam is generated, one can for example Bring the heat exchange coil directly into the melt and thus take advantage of the very high heat transfer coefficient of the melt.

Depending on the type of carbonaceous fuel used, this can turn out to be a by-product Gases such as hydrocarbons, tars, OIL partially oxygenated organic compounds, carbon monoxide and their Form mixtures that do not fully react with the sulfate ions before they reach the upper range of the Reactor 12 have reached. In addition, carbon monoxide is a minor fraction under most conditions Product of reaction (2). This gas can be mixed with the unreacted by-product gases over the melt with an optionally introduced air stream such as 128 in FIG. 2 or burned in a separate furnace, obtained as a by-product or - as with stream 20 shown in the drawing - be passed through the melt in reactor 12 again. Carbon dioxide and Water vapor from the reduction reaction and nitrogen from the air are removed on line 18 from the Reaction 12 removed.

The F i g. Figure 2 shows a preferred form of reactor for use in the present invention.

The reference numeral 100 denotes a reactor comprising a sulfide oxidation zone 102 and a sulfate reduction zone 104, which are separated from one another by a partition 106 provided with slots.

Dip TrpnnwanH Iflft ict with 7wpi arnRprpn Affniiniron

108, 110 , which establishes a flow connection between the zones 102, 104 . The sulfide oxidation zone 102 has associated therewith an air inlet and manifold system 112, a heat exchange device 114, a salt inlet 116 and a gas outlet 118 . The sulfate reduction zone 104 is assigned an inlet 120 for the carbonaceous material, a melt outlet 122 and a gas outlet 124 .

During operation, the reactor is filled with the melt 126 to above the opening 110. Air is supplied to the oxidation zone 102 through the manifold system 112 so that sulfide salts are oxidized to sulfate salts in accordance with reaction (1). The introduced air also causes an upward flow of melt in zone 102, bringing hot melt into contact with heat exchange element 114. The heat exchange element 114 draws off some of the heat generated in the exothermic reaction. Nitrogen from the air supplied "leaves the oxidation zone of the reactor through line 118.

The circulating currents produced in the melt cause oxidized salts to flow through the opening 110 into the reducing zone 104. Here a source of carbonaceous material 120 is added to the melt so that the sulfate is reduced to the sulfide after reaction (2). The carbon dioxide produced in this reaction leaves the reactor vessel from zone 104 through opening 108 in partition 106 back into zone 10Z. A portion of melt 126 can be drawn off at 122 in order to

so to remove impurities that have accumulated; the pure salt is returned to the reactor vessel at 116

Alternatively, the reactor 100 need not include a partition 106. In this situation, reactions (1) and (2) take place simultaneously. In this case it is preferable that carbon is present in excess, so that reaction (2) is favored in the functional equilibrium and the sulfur is essentially completely in the sulfide form in the melt.

Under these conditions, the oxygen reacts preferentially with the sulfide, not with the carbon. In other words, the mechanism of reaction (2) results in almost complete consumption of the Carbon.

As now the F i g. 1 further shows the process of Removal of the impurities shown with four main stages The melt withdrawn from the reactor 12 22 is fed to a dissolving tank 24, if desired

the melt can be cooled by heat exchange before it is introduced into the tank 24. The Bred melt with an aqueous solution in contact. In the preferred case shown the melt is treated with a stream 44 of an aqueous make-up solution of sodium bicarbonate. The bicarbonate of the treatment stream reacts with the sodium sulfide according to the equation

NaHCC ₃ + Na ₂ S-Na ₂ CO ₃ + NaHS (3)

to sodium carbonate and sodium bisulfide. The resulting Mixture of soluble salts and insoluble ash is placed in a filter 28 or other similar Given conventional separating device in which the ash is separated and discharged on line 30 will. After separating the insoluble components, the aqueous solution from line 32 is in a Carbonization tower 34 of conventional design out in which the solution with carbon dioxide at a

to

25th

t approximately 0.6 to 10.3 bar (10-150 psi) is treated. That The result of the carbonation is the conversion of the sodium bisulfide to sodium bicarbonate according to the following Equation:

NaHS + CO ₂ + H ₂ O-NaHCO ₃ + H ₂ S (4)

The hydrogen sulfide which forms during this reaction is drawn off on line 38 and can a conventional plant for the production of sulfur or sulfuric acid.

Some of the bicarbonate produced is soluble and some is insoluble. All of the slurry is fed on line 40 into a filter 42 or conventional separation device which has the separates soluble from insoluble fraction. The soluble part is on the line 44 in the dissolving tank 24 returned, while the insoluble solids on line 46 to reactor 12 goes.

By continuously withdrawing and processing part of the melt in this way. ^! »Avoid excessive accumulations of sulfur and ash.

As already mentioned, the amount of melt withdrawn for processing and the amount of hydrogen sulfide obtained depend on the concentration of the ash and sulfur in the carbonaceous raw material. In general, an amount of sulfur of from about 1 to about 25 weight percent, preferably 2 to 10 weight percent, should be maintained in the furnace melt. The correct amount of sulfur depends on the design of the reactor. The primary limiting factor is that the melt must contain enough sulfur that reactions (1) and (2) preferentially occur while the reaction C + O ₂ - CO _{2 is} suppressed. If the reactor is divided into two zones in which there is little, if any, direct contact between the carbonaceous material and the oxygen, the amount of sulfur required as sulfide or sulfate is not so great. If the design of the reactor permits intimate contact between the carbonaceous material and the oxygen source, higher concentrations of sulfur in the sulfide form are required. The ash content should be kept below about 20% by weight.

The generation of heat by the method described here has compared to conventional methods numerous key advantages. The heat generation and the temperature are called each other by controlling the Adjust the air supply precisely. A second, very important one The advantage of the present invention is the lack of emission of contaminants.

The low reaction temperatures that occur hinder the formation of nitrogen oxides, and the melt absorbs gaseous sulfur compounds up again very quickly, so that there is no significant source of air pollution. The ash is also retained in the melt, so that? there is no particle emission in the exhaust gas. The effect of the present procedure is very high, because the oxygen content of the air fed in is completely and quickly consumed. As consequence very little heat is wasted heating up excess gases - unlike conventional combustion processes. Furthermore, the heat transfer r.vcn in the liquid Melt much higher than in a conventional vjicr. cccr i-vcr, 5c !. wc GiO WarrriCüDeriragüng; r: one; gaseous medium must take place. In addition, it is expected that the output power per unit volume of the reactor in the present invention is significantly higher than has previously been commercially attainable. Furthermore, the present process can produce heat from a wide variety of carbonaceous Fabrics, and it can be done successfully over a very wide range of pressures.

The use of heat for pyrolysis

This aspect of the present invention is directed generally to the pyrolysis of carbonaceous substances Materials for the production of valuable gases and liquid products or for the production of coke or for the disposal of solid waste. A wide variety of different treat carbonaceous materials, including wood. Peat, lignite, coal, oil and miscellaneous urban, agricultural and commercial waste. The carbonaceous material is through contact with a molten salt - preferably an alkali metal melt or a molten metal a mixture of alkali metal salts - pyrolyzed very quickly.

The in the F i g. 3 applies to the method in general. Depending on the nature of the carbonaceous starting material, pretreatment by grinding or crushing or to remove non-carbonaceous components can be used. This pretreatment applies in particular if the raw material consists of non-homogeneous waste. The carbonaceous raw material 50 is placed in a pyrolysis vessel 52 in which it is brought into contact with a hot alkali metal salt melt. The working temperature is between about 400 and 1300 "C, preferably in the range of about 700 to 900 ⁰ C. The melt is thereby about 1 to 25 wt ° / o of sulfur present as sulphide or sulphate; the rest of the Melt can consist of other alkali metal salts which are compatible with the sulphides and sulphates at the working temperatures. A preferred Sa'zkiassc =. ^R .t die ^? ' Alkali metal carbonates including mixtures thereof For a better explanation, the constituents of the melt are to be regarded here alternately either as compounds per se or as the ions which they contain.

As a result of contact with the hot melt, the carbonaceous raw material becomes gaseous

Components like CH ₄ . H ₂ . C ₂ H ₄ . C ₂ H ₆ . CO and CO ₂ as well as water vapor and condensable organic gases are pyrolyzed; these products are shown as effluent 54 exiting vessel 52. The absirom is a source of valuable gaseous and liquid components or fuels. Simultaneously with the formation of the gases, charring also arises in the pyrolysis reactions, which can be obtained as a salable product. If the carbonaceous raw material 50 is made of coal, for example. it is quickly transformed into gases and valuable coke. A stream of coke and molten salt 56 is continuously withdrawn from vessel 52. A portion of the coke can be filtered off from the molten salt or isolated as it is and caught in the air as a separate product.

Alternatively, an optional steam supply 48 can be used to remove the carbon material after the reaction

HjOh-C-COh-H ₂

Manifold system 212, melt outlet 226 and en Associated with gas outlet 216, the sulphate reduction zone 204 a molten coal inlet 218, an inlet 224 for eirc er.ijnzcnde ΚοΜε / Liifiilir. a melt outlet 220, a Gfisauslalj 222 and a return line 214 for purified salt.

The reactor is in operation with the melt up to over the opening 210 in the partition wall 206 is filled. Air is supplied to the oxidation zone 202 through the manifold system 212 supplied so that the sulfide salts are oxidized to sulfate salts according to the reaction (I). Introducing of air continues to cause an upward melt flow in zone 202. Nitrogen from the introduced air leaves the oxidation tube 202 of the reactor on line 216. Circulating flows, which arise in the melt, cause oxidized salts through the opening 210 into the zone 10-04 stream. This is where the melt 118, the char (line 56 in FIG. 3) and possibly

gas; So you can convert a larger proportion of the carbonaceous material into valuable gaseous Convert products.

The char and molten salt mixture $ 6 from the vessel are fed to a heating vessel 60 in which the remaining char is consumed in one of two cyclic reactions, which together produce enough heat to meet the heat requirements of the pyrolysis. The vessels 52, 60 can be the zones of a single reactor design. These reactions that take place in the heating vessels are identical to those described above for heat generation. A source of oxygen, such as air 62, is supplied to vessel 60. Furthermore, if necessary, a carbon source 64 can be supplied. The heat generated in reactor 60 is given off to the molten salt mixture, which is then returned to vessel 52. This heat generating reactions are carried out at more than 600 ° C. preferably between about 800 ⁰ C and about 1300 ° C. The temperature of the heat generating zone is normally kept at least about 50 to 100 ^° C. above the temperature of the pyrolysis. The reaction products 68 - mainly CO ₂ and N ₂ . when air is used as the source of oxygen - are expelled from reactor 60.

In addition to a carbonaceous reducing agent and a reactive oxygen form, it can at times it may be desirable to add a catalyst for the reduction reaction. Iron has proven to be for this reaction proved to be well suited. One can therefore use an amount of about 0.5 to about 7% by weight of the Use melt. The iron can be eieniuiiar or in Form of ferrous compounds are added with the other constituents of the melt are compatible - for example as iron sulfide or iron sulfate.

FIG. 4 shows a preferred form of reactor which is useful in pyrolysis applications for supplying heat to the melt. Reference numeral 200 denotes a reactor vessel from a sulphide oxidation zone 202 and a * · Svlfatreä'.ikiionszone 204, ingenious and "gs"^# else are separated by a partition provided with Schulzen 206th The partition 206 is provided with two larger openings 208, 210, which establish a flow connection between the Ζοη_ίΐ 202, 204. The sulphide oxidation zone 202 is given an I uf ^ '-! SÖ- i.fid, and the sulphate is reduced to sulphide by the coal in accordance with reaction (2). The carbon dioxide produced in this reaction exits the reactor vessel at 222. Reduced melt a'is the zone 204 is guided by the existing flows through the opening 208 in the partition 206 to the zone 202. Heated melt is withdrawn at 220 or 226 and returned to the pyrolysis zone. A portion of the melt 220 can be removed to remove contaminants that have accumulated. The purified salt is returned to the reactor vessel at 214.

Alternatively, the partition 206 need not be present in the reactor 200; then the reactions run (1) and (2) simultaneously. In this case, the carbon is preferably in excess, so that in Equilibrium state the reaction (2) is favored and the sulfur in the melt essentially is entirely in sulfide form. Under these conditions, the acid reacts preferentially with the Sulfide, not directly with the carbon. In other words, by the mechanism of reaction (2) becomes essentially all of the carbon is consumed.

As shown in FIG. 3, a portion 70 of the melt from the reactor 60 becomes a zone 72 for Removal of impurities deducted. The amount and type of that present in the melt Impurities will depend on the source of the carbonaceous feedstock 50. The most common Contaminants are ash and sulfur. Around To remove, molten salt 70 is extinguished in water, the ash is filtered out and the remaining solution with Carbon dioxide brought into contact, so that any salts present in sulfide form form bicarbonates are converted and hydrogen sulfide is formed. The bicarbonate slurry is then filtered and the solution is returned to the quenching stage and the solid bicarbonate is returned to the heating reactor. The bicarbonate decomposes to carbonate on heating. Illustrative part of this process is the removal of impurities at 72 as melting salt inlet 70, carbon dioxide inlet 74, Schweieiwassentoisysgi.ig 76, ash outlet 78 and salt recirculation 80 shown.

The flow chart of FIG. 1 «represents a preferred method of removing contaminants.

by performing the pyrolysis ·> e ^ .er Saizschr .-. ske in the manner given before: the present invention Hureh :: /.- ri. . ^ -, v. .-icn iaiilre-che benefits.

Pyrolysis takes place very quickly in a molten salt, so that one obtains high gas yields and a high throughput. Furthermore, there are impurities retained in the melt and no open flame required for heating; in this way problems with air pollution are eliminated The pyrolysis coal, the lowest value by-product, is used to generate heat for the process. In the case of pyrolysis of solid waste, the process has the Benefits of eliminating air pollution, potential revenue from the sale of by-products, eliminating the need for large Excess air as well as applicability to a wide variety of waste materials - including Polyvinyl chloride, rubber, sewer sludge, nylon, chemicals, pesticides as well as agricultural, urban and industrial waste.

The use of heat for Hydrocarbon conversion reactions

This aspect of the invention is directed generally to the conversion of hydrocarbons to more valuable substances by the application of heat. Other important variables are the type of catalyst, the pressure, the temperature and the presence of hydrogen. The F i g. 6 shows a flowchart of the principle of the process as the basic steps of treating a hydrocarbon with a hot melt containing an alkali metal carbonate-sulfide mixture and drawing off and separately heating the melt in order to supply the heat for the conversion reaction. A hydrocarbon feedstock 130 is introduced into converter 132 in feed zone 134. The composition of this flow depends on the conversion process being carried out. but is generally made from methane (for the production of hydrogen), ethane (for the production of ethylene), light hydrocarbons, naphtha. Kerosene. Refinery gas. Natural gas, light gas oil. heavy gas oil. Residues from distillations under vacuum or air pressure, tar, as well as native hydrocarbon-containing materials such as crude oil. Money. Oil shale and tar sands were chosen. After it has been introduced into the converter 132. enters the Ausgangsmatenal in contact with a salt melt at a temperature of about 400 ⁰ C to about 00 ° C. Il depends on the desired conversion reaction. If hydrogen is involved in the reaction, a hydrogen stream 174 can be fed to converter 12 in feed zone 134. When it comes into contact with the hot melt, the transformation of the starting material begins; the lighter hydrocarbon gases and liquids flow up through the packed bed IJ6 of converter 132, generally countercurrent to the hot melt.

The converter is designed so that the conversion reactions are terminated when the gases Reach the top of bed 136 and enter header area 138 of the converter reactor. The product gases are discharged on line 135. Heavy products such as coke are left behind in the melt and sink to the sump 140 of the converter. From there the melt and the charring coal or coke contained in it, on line 142 into a Heated Zougutigszone 144 transferred.

The composition of those involved in these processes

The molten salt used may change depending on the conversion process to be carried out - especially with regard to the composition of the Kataysators, as will be described below.

Nonetheless, it is critical that the melt contain about 1 to 25% by weight of sulfur as sulfide. the Alkaline metal ions are the preferred cationic component of the melt, although other metal ions can be present. A great deal for most purposes

ίο the desired melt consists of alkali metal carbonate and alkali metal sulfide. The use of the carbonate is particularly advantageous when sulfur is extracted from the Products should be eliminated because the carbonate has the ability to absorb sulfur-containing compounds men that at elevated temperature from the output material are released. For example, the mechanism in hydrocracking can be represented as follows:

RSR '+ H ₂

catalyst

RH + R'-H + H ₂ S

where R and R 'represent the hydrocarbon part of a sulfur-containing molecule Hydrogen sulfide is released from the carbonate melt after the reaction

KjS + M ₂ CO ₃ - M ₂ S + CO ₂ + H ₂ O

included, ir the M denotes an alkali metal ion. This absorption reaction is controlled by equilibrium. The equilibrium constant

[(CO ₂ XH ₂ OXM ₂ Sy (H ₂ SXM ₂ COj)]

and the free energy of this reaction with M = sodium as a function of temperature are given in Table I. summarized. in which a negative free energy is an extremely favorable situation for the forward reaction indicates

Table I. Hydrogen sulfide absorption

temperature Equilibrium free energy « ^(Q constant (kcal / mol) 427 0.0140 + 5.95 527 0.137 + 3.16 627 0.744 + 0.53 so 727 2.68 -1.96 827 7.23 -4.33 927 15.2 -6.56

Relatively high temperatures and low water and carbon dioxide concentrations change Absorption reaction. At lower temperatures, the reverse reaction (i.e. the regeneration of the Carbonate melt) can be carried out by what supplies steam and carbon dioxide. This latter The reaction is detailed below.

In the reactor 144, the withdrawn melt, the contains carbonaceous coal or coke, with a reactive oxygen source - preferred wise air 146 - brought into contact. Due to the sulphide content of the melt, the oxygen oxidizes it Sulfide preferably over the carbon in the melt according to reaction (I). the above for

Heat generation has been explained. Simultaneously the carbon in the melt reacts with the sulfate formed in reaction (1) as described above explained reaction (2).

As a result of these reactions, enough heat is generated to keep the conversion reactions occurring in reactor 132 going. Because the melt must be returned to the converter 132 in the sulfide form, the ratio of carbon and of the oxygen in reactor 144 must be high enough. If the melt entering reactor 144 does not contains enough carbon, an additional source of carbon 148 can be provided.

By maintaining a proportion of about 1 to 25% by weight and preferably 2 to 10% by weight of sulfur in the melt, it is ensured that reactions (1) and (2) preferentially over reaction C + Oi —CO ₂ expire. In other words, essentially all of the carbon should be consumed by the mechanism of reaction (2)

In addition to a carbonaceous reducing agent, L e. the char from the hydrocarbon conversion reaction or the additional carbon source, it may at times be desirable to use a Provide catalyst for the reduction reaction (reaction (2)) in the melt. Iron did for this Reduction reaction proved to be a good catalyst. So you can get an amount of iron in the range of about 0.5 use up to about 7% by weight of the melt. The iron can de; Elemental melt or in the form of iron-containing compounds such as iron sulfide or Iron sulfate can be added to the other Components of the melt are compatible. Alternatively the catalyst can be included in the bed in converter 132 or deposited on it.

The F i g. Figure 7 shows a preferred form of apparatus for performing heat generating Reactions. Reference numeral 300 denotes a reactor vessel composed of a sulfide oxidation zone 302 and a sulfate reduction zone 304 separated by a slotted partition 306. The sulfide oxidation zone 302 is an air intake and distribution system 312 and a gas outlet 315 of the sulphate reduction zone 304, a melt inlet 314. an inlet 318 for additional carbonaceous material, a melt outlet 120 and a gas outlet 324 are assigned.

The reactor is in operation with the melt 322 bis Filled via the opening 310. Air is supplied to oxidation zone 302 through manifold system 312, see above that sulfide salts are oxidized to sulfate salts after reaction (1). Introducing air also works an upward flow of the melt in the Zone 302. Oxygen from the introduced air leaves the oxidation zone of the reactor through line 316. The resulting circulating currents in the melt cause oxidized salts through the Flow opening 310 to reduction zone 304. Here on Inlet 314. becomes melt with a source of carbon containing material or supplementary carbonaceous material 318 supplied so that the sulfate after the Reaction (2) is reduced to the sulfide. The resulting carbon dioxide emerges from the reactor vessel at 324 off. Reduced melt from zone 304 is caused by the prevailing currents through the opening 308 in the partition into zone 302. Sulphide-containing melt is taken off at outlet 320 and passed through a heat exchanger 154 (Fig. 6) fed to a desulfurization unit. The escaping gases can be subjected to a heat exchange.

Alternatively, the partition wall 306 in the reactor 300 can be omitted. In this case, reactions (1) and run s (2) together. The carbon is preferably present in excess, so that reaction (2) is favored in the equilibrium state and the The sulfur present in the melt remains in the sulfide form. Under these conditions, the reacts

in oxygen preferably with the sulfide, not directly with the carbon. In other words, the mechanism of reaction (2) leads to an almost complete one Consumption of carbon. As Fig.6 shows, part of the heated

II melt from reactor 144 through line 150 returned directly to the converter reactor 132. A second part is through line 152 a Heat exchanger 154 is supplied, where it is cooled to a temperature of about 900 ° C to about 450 ° C will. From there he becomes a Sch'A'cfcieRifernungseinhci through line 156; i5S passed Sn this In the unit, the molten sulfide salt is preferably treated countercurrently with a stream 160 containing carbon dioxide and water vapor

r. Drawing shows one can see the carbon dioxide from the reactor 144 via the line 16Z the water vapor received over line 164. The result of this treatment in the unit 158 is as follows Reaction:

MjS-IH ₂ O-HCO ₂ -M ₂ COj-IH ₂ S

with M as the cationic component of the melt, i.e. usually a mixture of alkali metal ions. The hydrogen sulphide produced in this reaction

)> hydrogen is transferred to a Claus unit on line 166 168 where sulfur 170 is produced. Alternatively, you can use the hydrogen sulfide as a starting material for a sulfuric acid plant. That in the Unit 158 formed carbonate is on line 152

in again fed to the converter 132. The one in unity The proportion of the melt treated depends on the sulfur content of the feedstock. If the raw material fed to the converter is sulfur-free, a desulfurization unit like 159 is used

4> not required. However, contains the starting material Sulfur, the sulfur content of the circulating through converter 132 and reactor 144 decreases Melt while it takes sulfur from the feedstock. In this case so! '* E wish-

w worthwhile the sulfur content below about 25% by weight being held.

The conditions in converter 132 vary depending on the starting material and the conversion desired. The temperatures during the

■ ι cracking processes range from about 400 ⁰ C to ⁰ C. ItOO the lower portion part of the viscosity of the mixed phase separation and cracking. the upper part of the area shows stronger cracking processes such as coking. Catalysts can be added to the melt or in

M) the bed of converter 132 can be added to to increase the speed of the desired reaction. Preferred catalysts include Oxides and sulfides of iron, cobalt, molybdenum, tin, nickel, tungsten and other transition metals. Additionally

i >> the alkali metal sulfide part of the salt also has a certain catalytic effect.

Conversion reactions that require hydrogen, such as hydrocracking and hydrodesulphurisation

(Hydrotreating) can be performed when a stream of hydrogen 174 in the converter 132 introduces The converter 132 is further subjected to suitable hydrocracking and Hydroentschwefelungsdrücke, and are generally from about 6 to about 130 atmospheres psi at temperatures of about 450 to 550 ⁰ C range. Catalysts can also be used in these processes. Preferred catalysts include oxides, halides and silphides of transition metal elements.

The dehydrogenation takes place at low pressures and at temperatures of around 450 ° -950 ° C

Carrying out these hydrocarbon conversion processes according to the present invention has numerous advantages. For example, the Coke formation and deposit is no longer a major problem. The coke is removed from the conversion reactor with the molten salt and as Reducing agent used in the heat generating zone. In the method of the present invention The catalysts used are therefore not impaired or contaminated as a result of the direct If the hydrocarbon comes into contact with the molten salt, the heat transfer takes place at a very high rate Efficiency, and good temperature control can be achieved. Finally there is the hydrogen sulfide is completely converted to alkali sulfide in the conversion reactor, the gaseous products need not to be desulfurized. Due to the high reactivity of the carbonate melt with organic ones Sulfur / bindings, a large proportion of the sulfur is pus dep liquid products removed. As a result, the further processing of the cracked products is simpler and less expensive Compared to the preparation of the products obtained from other cracking processes. Furthermore, the All of the sulfur removed from the petroleum residues is recovered as hydrogen sulfide, which is easily converted to Can convert sulfur or sulfuric acid.

The following examples are intended to further illustrate the basic principles of the present invention.

Example I.
(Sulfate reduction with coal)

The sulfate reduction with coal was demonstrated in an experiment in which a total of 17.1 g of hard coal was added to a melt (100 g of Na ₂ CO ₃ , 100 g of KjCO ₃ and 100 g of Li ₂ COj), the 60 g of sodium sulfate at about 800 ° C contained. The experiment was carried out in a ceramic crucible. Samples were taken and analyzed at regular intervals. The sulphate content was determined by a conventional gravimetric method. The results are summarized in Table II below.

Table II Sulphate reduction with coal

Time
(min) ')

M ₂ SO ₄

reduction
(V.)

0 25.2 0.0 6th 24.2 4.0 12th 18.7 25.8 18th 14.6 42.1 42.5 7.6 69.8

Time
(min) ';

M ₃ SO ₄

reduction

66.5
90

7.1
6.2

72.2
75.4

") Time after the initial addition of coal, air melt.

in These results show that after about 45 minutes 70% of the sulfate had been reduced.

Example II
(Heat generation)

In another similar experiment, 12.0 g Coal used to partially reduce 60 g of sodium sulfate dissolved in 300 g of an alkali metal melt. The temperature of the melt was between 850 and

.'η 870 ⁰ C. After 15 min were reduced 44.7% of the sulphate to sulphide, after 25 min = w .- no further reduction of the sulphate is carried out, it was therefore assumed that the coal had been completely consumed in the reaction. The temperature of the system has been allowed to increase

> 5 stabilize, then air is passed through the melt. As soon as the air flowed in, the temperature of the melt began to rise rapidly and continued to rise. until the air supply was interrupted, then the temperature of the melt began to fall again. Became

for example Luf ». through the melt at 2.1 l / min passed, the melting temperature rose in 3.0 min from 8913 ° C to 918 ° C. Before and after introducing the air took the temperature of the melt at about 6 ° C / min

^from · Example III

(Effect of temperature and iron
on the reduction speed)

There Experiments were conducted to determine the effect of iron and a? R Tt poeratur to the sulfate reduction with coke. A eutectic alkali carbonate / sulfate melt with 100.8 g K ₂ COj, 100.8 g Li ₂ CO ,. 37.0 g Na ₂ CO, and 84.9 g Na ₂ SO ₄ (25% M ₂ SO ₄ ) with 2.5 times the stoichiometric amount of coke (36 g)

■ r. reduced. To determine the effect of iron on the rate of reduction, the melt initially consisted of 100.8 g K ₂ COj, 1003 g Li ₂ COj. 52.4 g Na ₂ COμ 643 g Na ₂ SO ₄ and 40.3 g FeSo ₄ · 7 [H ₂ O] (25% M ₂ SO ₄ ). During the trials,

Samples taken at regular intervals and checked for the sulfate ·. The sulphide and carbon content analyzed The results of these tests are summarized in Table III.

.. Table III

Reductions with coke

conditions

Reduction time (h)

600 ⁰ C

70O = C

700 ⁰ C with Fe

800 ⁰ C

800 ⁰ C with Fe ")

91
2.9
1.9
0.50
0.23

*) In this experiment the batch was stirred mechanically, not moved with a purge gas.

Example IV (generation of pyrolysis gases)

Various solid waste materials were brought into contact with a molten salt and the volume of the waste was determined. In each of these experiments, 485 g of salt (11.4% Na ₂ CO ₃ , 26.2% Na ₂ SO ₄ and 31.2% Li ₂ CO ₃ and K ₂ CO ₃ ) filled into a ceramic reaction vessel (inner diameter 50.8 mm, 381 mm high), to which a Pyrex tube with openings for the Caseirilass, the sample addition and the gas outlet was attached. The vessel was placed in an electric furnace and the temperature of the salt was raised to 850 ^° C. and held there. Small pieces (03-0.6 g) of various waste materials were placed in a perforated box and the reaction vessel closed. The exhaust pipe was connected to a water separator (magnesium perchlorate), which was connected to a vessel with water which was constructed in such a way that the gas flowing in had to displace the water into a cylinder provided with a scale. The perforated card with the solid waste material was immersed in the melt and the volume of water flowing into the cylinder was then determined. Table IV gives the results of these tests.

Table IV Volume of the pyrolysis gas Waste material

Gas volume (liters / kg) (scf / lb)

Sun-dried weeds Example V 786 (12.6) Sun-dried sheep dung 705 (Π.3) 487 (7.8) 387 (6.2) paper 742 (11.9) wood 586 (9.4) rubber 331 (5.3) Polyethylene 299 (4.8)

(Generation of pyrolysis gases)

The nichtkondisierbaren gaseous products of Schmelzsitizpyrolyse of paper and dried sheep dung were determined These experiments were carried out with 300 g of eutectic alkali carbonate at 790 "C and 0.8 ⁰ C waste samples. The reaction vessel was initially expressed with helium, then helium for transporting the product into a Gas chromatograph used for identification and determination The results were normalized to eliminate the dilution effect of the helium and the data are summarized in Table V.

Table V Molten salt pyrolysis of waste materials

In addition, small amounts of ethane and ethylene were observed. These results show that a hydrogen-rich valuable flammable gas is produced

B e i s ρ i e I VI (pyrolysis speed)

The pyrolysis rate of solid waste was determined by taking the exhaust gas volume as a function of

ίο time was measured. Attempts were made with the im Example I described device and the method carried out there Figure 5 contains the results of an experiment in which 0.58 g of sun-dried Sheep dung was pyrolyzed at 850 ° C. This figure shows that almost half of the pyrolysis must be carried out within just 033 min elapses and that after 2.0 min the pyrolysis was essentially complete. These: Results were typical of a large number of different solid waste materials that have been pyrolyzed in molten salts.

Example VIl (pyrolysis of hard coal)

The pyrolysis of a hard coal was investigated with the device and according to the procedure of Example I. This coal had an ash content of 10%, a water content of 19%, a sulfur content of 3.6% and a calorific value of 5560 kcal / kg (10000OBTU / lb .). The results showed that per: emerged n 0,454kg carbon at 85O ⁰ C liters (4,8scf) Gas (lib.). The analysis of the non-condensable gas shows that it contained about 45% H ₂ , 8% CO, 40% CH ₄ , 7% CO ₂ and smaller amounts of ethane and ethylene

Example VIII (pyrolysis of residual vacuum oil)

Vacuum residual oil was introduced into a carbonate melt and the volume (at normal temperature uo i -pressure) of the exhaust gas as a function of temperature certainly. This residual oil had a density of 1.0689, a crude oil content of 46.1% by volume and 50.4% by weight a sulfur content of 7.71% by weight and a Ramsbottom residue of 25.1% by weight. The data are summarized in Table VI.

Table VI Exhaust gas from residual oil pyrolysis Proportion of the component

hydrogen Carbon monoxide methane Carbon dioxide

paper paper Sheep damn 49 50 27 28 22nd 24 17th 10 15th 7th 14th 30th

Temperature C

Exhaust gas (ml / g)

450

595

825

60 240 550

The analysis of the non-condensable exhaust gas from the residual oil pyrolyzation. at 800 "C gave 35% H ₂ , 25% CO, 23% CH ₄ , 2% CO ₂ , 9% C ₂ H _4, and 5% C ₂ H ₆ .

Example IX (heat cracking of residual oil)

fr5 Vakuu.n residual oil was at 500 ° C in the presence of a Alkali carbonate eutectic thermally cracked in the melt state. The residual oil can be broken down as follows describe:

TnbelleVII
Description of the residual oil

Yield in crude oil
Yield in crude oil
Ramsbottom residue
Density at 15.6 "C

analysis

sulfur

carbon

hydrogen

50.4 wt%
46.1% by volume
25.1% by weight
1.0689

7.71 wt. O / o

80.36% by weight

9.58 wt. O / o

50 g of this residue in amounts of 2-3 g in a space (100 mm inside diameter, 200 mm Height) under a packed column (50mm id, 610mm high, packed with 6.4mm aluminum

The Psck

sckün ¹ * wsr with

150 g (50 g each of Na ₂ CO _3. Li ₂ CO ₃ and K ₂ CO ₃ ) alkali metal carbonate salt coated. The temperature of the entire system was kept at 580 ⁰ C, then with helium (100 ml / min) the petroleum gases through (1) the packed column, (2) a water-cooled condenser, (3) a dry ice-acetone cold separator and (4 ) flushed a gas chromatograph. The coke produced during the experiment was oxidized with oxygen and the product (carbon dioxide) was collected and measured. The test results were as follows:

Table VIII
Income

Presumably, the remaining 20% of the raw material consisted of heavy tars and oils as well as coke remaining in the flow leashes of the arrangement.

Example X
(Thermal cracking and dehydration of ethane)

300 g of a melt consisting of equal _{parts by weight of Li 2} CO ₃ , Na ₂ CO ₃ and K ₂ CO ₃ in a ceramic crucible were used for cracking and dehydrating ethane at various temperatures. In the experiment, ethane was sent through the melt (75 mm deep) at 1 liter / min, and the products were then analyzed by gas chromatography. The following reactions took place:

C ₂ H ₈ -CH ₄
C ₂ Hs-H ₂ + C ₂ H ₄

Table IX summarizes the results of the tests at various temperatures.

Table IX
Ethane cleavage

Temper. »* Ur Ethane conversion
( ⁰ C) (%)

,, ..... Reaction (b)

Ratio ^; -

Reaction (a)

material

Yield (g)

650 1 28

775 24 12

975 92 0.5

coke

Oil (from the condenser)
light products (from the cold separator)
non-condensable gas

10.4

13.8

6.3

10.0

Example Xl
(Desulfurization)

The mechanism by which carbonate melts are used to desulfurize in hydrocracking can be explained as follows represent as follows:

A. R — S — R '+ H,

- ♦ R-H + R '- H + H ₂ S

catalyst
- »M ₂ S + CO ₂ + H ₂ O

B. H ₂ S + M ₂ CO ₃

Both of these responses have been demonstrated. For example, with catalysts like the Routinely perform oxides and sulfides of iron, cobalt, tungsten, nickel and molybdenum in reaction (A); metal sulfides can therefore be used as catalysts. Adding these catalysts to a molten alkali carbonate sulfide mixture should not hinder their reactivity. Rather has it has been shown that sulphide, iron and iron compounds such as iron sulphide promote the sulphate reduction by hydrogen in catalyze a molten salt.

Reaction (B) has also been demonstrated. 130cm ³ / min H ₂ S and 370cmVmin CO _{2 were} mixed in a mixing chamber and then through a 102 mm (4 in.) Deep alkali metal carbonate melt of 100 g K ₂ CO ₃ , 60 g Na ₂ CO ₃ and 100 g Li ₂ CO ₃ (respectively bubbled in Reagensqualiät "the reaction vessel consisted of Vycor and was charged with an electric furnace (manufactured by Marshal) at 500 ⁰ C heated the experiment was carried out for over an hour, and samples at the beginning, were taken in the middle and at the end of the experiment The water was trapped with Mg (CIO _{4 I 2} , the remaining gases examined by gas chromatography. Aliquots of the inlet and outlet gases were introduced into the chromatograph with a Perkon-Hmer sample valve. Table X shows the results.

As the gas chromatographic results in Table X show, almost 100% of the H ₂ S was initially absorbed, and about 50% at the end of the one-hour test period.

Table X
In / outlet gas analysis for H ₂ S / CO ₂ plus M ₂ CO ₃

Time

CO ₂

H ₂ S

Inlet

18.0

Ausiaii 100 0.35 4 min 99 3.1 10 min

continuation

CO ₃

H ₂ S

99 4.4 93 5.4 97 6.7 96 7.4 97 7.9 96 9.2

Outlet

15 minutes
19 κ. m
25 min
32 min
42 min
53 min

All numerical values are the relative peak heights on the gas chromatograph.

This example shows the ability of an alkali carbonate hmelze. to absorb HjS at elevated temperature.

Example XII (desulfurization of coke during heat generation)

An experiment was performed in which finely divided coke at regular intervals of a eutectic Alkalicarbonatschmelze (315 g) with an initial 15 g of sodium sulfate at 800 ⁰ C (1472 ° F) was added. At the same time, air was passed through the melt in order to reoxidize the sulfide to the sulfate. Of the

The experiment was continued after the addition of 192.4 g of coke and after the sulfide had been completely converted Completed sulfate. Table Xl confirms the results

Table XI

Sulfur collection in the melt

M ₂ SO ₄

S.
rOew .-%)

S.
(G)

S addition (g) *>

Beginning
end

4.53
7.50

1.06
1.76

3.34
5.54

0
2.67

•) With an assumed sulfur content of 1.39% of the coke (information from rhiiiips reiiuicuiii Cu.).

These results show that the sulfur content of the melt increased by 2.2 g, while theoretically 2.8 g Sulfur was added to the melt. The sulfur accumulation in the melt represents 81% of the theoretical amount added. When generating heat So essentially all of the sulfur remains in the melt and is not passed on as an impurity Circulating air released.

In addition 5 sheets of drawings

Claims (2)

Patent claims: 1, method of pyrolysing carbonaceous materials, these carbonaceous Materials brought into contact with a molten body of salt in a pyrolysis zone and the carbonaceous material is converted into pyrolysis products, including coal products, and the coal products to containing melt brought into contact with a source of reactive oxygen and thereby in sufficient heat is generated in the melt to maintain the pyrolysis reaction in the pyrolysis reaction zone, characterized in that, that the molten salt! contains up to 25 wt .-% sulfur in the form of sulfides and / or sulfates and the The pyrolysis reaction zone is maintained at a temperature of 400 ° to 1300 "C. 2. Process ¹ according to claim 1, characterized in that, in the step of contacting the material containing carbonization products, part of the melt with part of the carbonation products contained therein is withdrawn from the pyrolysis reaction zone, the withdrawn melt is passed into a heat generation zone and there with the source reactive oxygen is brought into contact with consumption of coal products and oxygen after the reactions: consists mainly of a salt from the group of alkali metal carbonates and mixtures thereof