DE1471569A1 - Production of ash-free coke from coal - Google Patents

Description

The lummus öompanv Re / Zg- 3859

Process for the division of asohe-free coke from coal

The invention relates to a method for the production of carbonaceous substances from coal, in particular the
Production of practical asohe-free coke from coal, belonging to the group of bituminous coal, sub-bituminous coal
or lignite is selected.

Currently, most of the carbon calcined electrodes are made from petroleum coke End product from which coke is made, which is obtained by carbonizing coal tar pitch. Considering the ever increasing need for petroleum coke for the manufacture of anodes

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(Z96t -6 P Ά -eiÖsßuaopuy sop ε ₂ ; e _S L UN Z ^ VI § L W)

New subjugations in accordance with Article 7, Paragraph 2, No.

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. made of carbon! represents coal an abundant one Source material for coke that is suitable for this purpose

Carbon consists mainly of three-dimensional condensed cyclic structures with high molecular weight structures are occurring ^ R all six membered rings. Bituminous coal can be viewed as an intimate mixture of bitumen and humic acids that are similar in that. both have large, flat aromatic lamellar structures. However, they differ in molecular size, the degree of aromatic properties, the oxygen content and the amount of crosslinking. .

Mineral substances, fecal charcoal, volatiles and moisture are primarily the other components that are present in the charcoal. Mineral substances that were deposited in sedimentary deposits by infiltration of the groundwater during coalification and that remain after the coal has been burned _P are called ashes. Fiber charcoal, which practically burns completely when coal is burned, can be used as mineral charcoal.

The rank of coal (i.e. the degree of coalification) depends on their carbon content, which increases with the natural series of lignite, sub-bituminous and bituminous coal. In this Series, the carbon content generally increases while the moisture and oxygen content decrease

The presence of coal, mineral substances (as ash analyzed) and bound sulfur are the main reasons for the uselessness of coal for the production of coke, which for Production of anodes is suitable, which are used in the production of aluminum. There is sulfur in coal in general in Fprm of organic sulfur compounds, as pyrite and / or

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contained as organic sulphate "It is known that the ratio of inorganic sulphate and pyrite to organic sulfur increases in coals with increasing total sulfur content"

A number of methods have already been known to obtain the In Coal to reduce the existing content of Psβerkohlβ or mineral charcoal and of mineral substances or ash *

Which z.Bo known Broohe process in .an erikaniB c hen P atent- Bohrlft Hr - Sin method sur coal extraction is known as Pott. 1 881 927 . Thereafter, a carbon * is - extract by treatment of a portion of kohlestoffhaltlgem material prepared as for example stone coal, brown coal or peat having two ropes tetralin, to the at a temperature of 320 ° to 400 ⁰ G and a pressure of about 100 atmospheres, a solution of Form coal su. The minimum temperature during extraction is determined by the decomposition temperature of the coal used as the starting material. The insoluble and dissolved particles are separated from the solution by centrifugation. The Tatralin is then distilled off from the solution obtained to a coal extract BU, which has a smaller percentage of ash, as originally in the raw coal was present "The separation of the undissolved and insoluble particles from the solution was carried out more effective later in the solution by • A variety of ceramic filters have been passed through. The loss of solvents during separation is one of the disadvantages encountered with these separation processes. They also consist of the solution in other processes for separating fiber charcoal, ash or similar impurities. Another problem is coking at various stages of the process during extraction and separation.

In U.S. Patent No. 2,166,521, Pott describes a method of using the charcoal extract used in the above

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mentioned process is incurred in order to produce a semi-coke or full coke. The semi-coke or full coke is produced by mixing the coal extract with a semi-coke (which is obtained beforehand in the process), in which a coke oven is charged with the resulting mixture. The mixture is heated in the coke oven to a temperature of 450 ° - HOO ⁰ O in order to produce semi-coke or full coke, depending on whether a low or high temperature is maintained in the oven. The coke produced by the coke oven was low in ash and suitable for use as metallurgical coke for making electrodes.

It is an object of the invention to provide a new method of manufacture of practically ash-free coke and valuable components from coal, such as gas, aromatic solvents and Specify oils and ammonia in which a solution of bituminous coal, sub-bituminous coal or lignite in an organic Solvent is coked.

It is also an object of the invention not only to provide a method for producing ashless coke, but also to provide a? to gain valuable by-products.

A cyclical process by coking a deashed solution of carbonaceous substances is preferred, where at the vaporous products recovered from the coking unit, at least part of what is required Represent the solvent that is required for the preparation of the solution of the carbonaceous substance.

According to the invention, the method is carried out such that a mixture of coal in an organic solvent having a high aromatic content and an initial boiling point greater than about 34O ⁰ C is used as carbon

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is that further close separation of the suspended mineral Substances, the 3? Aserkohle and the inorganically bound sulfur the coal solution to a temperature above the incipient coking temperature of the coal is heated in the coal solution that then in a known per se Is coked wise and that ashless coke and vapors are collected. .

The invention is to be explained in more detail using an exemplary embodiment:

For example bituminous or sub-bituminous coal or Lignite and / or a mixture thereof are collected and in a ground or pulverized state continuously brought into a dissolving tank at a desired throughput, in which a pressure between about 1 and or 8 atmospheres. A conveyor feeds the coal into the dissolving tank without any loss of pressure.

The highly aromatic, high-boiling liquid solvent is introduced into the dissolving tank in an amount such that the ratio of solvent to charcoal is between 1/2: 1 to 6: 1. The dissolving tank is situated at a temperature between 316 ° and 455 ° C (600 ° and 850 ⁰ P), preferably between 400 ° and 4-25 ⁰ G (750 ° and 825 ° F) and above the final decomposition temperature of the Related as a raw material coal whereby a substantial portion of the extractable carbonaceous material in the raw coal is thermally depolymerized.

The products of the depolymerization are soluble in the highly aromatic solvent and thus form with the Solvent the carbon solution. Important dissolved and insoluble components that contain undissolved extractable carbonaceous matter and insoluble minerals or Ash and mineral charcoal are suspended in the coal solution.

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Since the solvent can have an initial boiling point (converted to one atmosphere) of only 344 ° C. (65O ⁰ S ¹ ), while the solution temperature is 455 ⁰ C (SiO ⁰ F); is the dissolving tank with a vent line

j provided to deduct the lowest components of the Allow solvent and other volatile

• Substances given off by the raw coal. One

practically uniform coal solution, in which undissolved and insoluble solid substances are suspended, which contain the mineral charcoal and mineral substances or ash, is drawn off via a discharge line located at the bottom f and passed on via a cooler to a continuous rotary filter.

The coal solution is sügekühlt to a temperature of 205-371 ⁰ C (400 ° to 700 ⁰ I ^1), while passing through the radiator. Preferably, the filter is coated with conventional filter aids and is normally operated at a pressure of about 2.8 to 4.2 kg per cm (40 to 60 psig) to effect effective removal of virtually all suspended solids, including undissolved ones carbonaceous matter. The filter cake is washed and dried to recover absorbed solvent and is withdrawn from the filter through the line. The coal solution is then heated to a temperature of 455-566 ⁰ G (850 to 1050 ⁰ F) in a heat exchanger and is fed to a Yerkoker, wherein the batch is agrsetzt into coke and gaseous exhaust. The discharge from the coker is fed to a fractionation unit which is provided with suitable fractionation trays (not shown). Inserting the trigger into the tower can cause foaming. This can be prevented by the addition of a small amount of an antifoam agent added at the point of introduction or at a higher point in the tower.

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The products delivered by the combination tower near the top contain condensable and non-condensable components. You will be forwarded to the usual processing units, to separate the condensable components from the non-condensable ones. A medium and semi-heavy oil is made from removed from the tower at an intermediate point and continued to the baffling units. Part of the middle Oil is split into two parts for introduction into the tower as reflux.

The floor of the tower in a line is continued to an intermediate tank. By a suitable control of the temperature in the tower the Destillierfraktion has an initial boiling point in the conduit (converted to an atmosphere) is between 343 ° and 455 ⁰ C (650 ° to 85O ⁰

and represents all or part of the solvent used to dissolve or digest the extractable carbonaceous material in the powdered raw coal fed. The requirements in the processing of bituminous coal to the solvent can be satisfied generally by the Fraktionsereinheit is operated so as to give a Jiestillat, one of fängliche boiling temperature (converted to an atmosphere) of about 400 ⁰ C (75O ⁰ F ) owns. If additional solvent is required (above 400 ° 0+ distillate) the fractionation unit can be operated to produce a distillate which has an initial boiling point (converted to one atmosphere) as low as 343 ° C (650 ° F). If so desired, the fractionation unit can be operated to yield the latter distillate by withdrawing excess solvent which is not necessary for the requirements in the dissolving tank for use in other process steps.

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The solvent required at the beginning is also introduced into the intermediate tank. The amount of the necessary Solvent to obtain a ratio of solvent to coal 1/2: 1 to 6: 1 is taken from the intermediate tank led to the dissolving tank. After start-up, if the amount of active solvent exceeds the dissolution requirements, solvent can be withdrawn from the intermediate tank. It is generally believed that the solvent requirements for dissolving bituminous coal through control the operating pressure and the operating temperature of the combination tower can be met, so that the direct supply the distillation fraction can be carried out to the dissolving tank, in which case the intermediate tank is superfluous.

The following examples are intended to further illustrate this invention. However, the individual details are not to be understood in a limiting sense.

Example I.

According to the invention, a bituminous coal was made with the following composition

Analysis ' weight percent

Moisture content 1.4

volatile substances' j> 6.6

solid carbon 56, .6

Ashes 5.4

comminuted, pounded and ground to such a particle size that i7.3 i ° was retained on a 0.147 mm clear sieve (100 mesh). For comparison points it was found that the proportion of bound sulfur was 1.46 percent by weight. The crushed coal and a tar distillate have an initial boiling temperature

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door of about 400 G ⁰ (750 ⁰ I ¹⁾ (converted to one atmosphere) and were introduced into the dissolving zone to produce a ratio of solvent au carbon of 3 - to give first The mixture wurde- stirred, cooled to a temperature of 232 ° G (45O ⁰ F) and a filter wäitergeleitet.. The filtered coal solution had the following properties:

Specific weight (1QO ° / 1OO ° F '1.2407

Softening Point ⁰ I (B + R) 152

Sulfur (weight percent) 0.46 residue of carbon (weight percent)

Ramsbottom 30.9

Conradson ■ 31.3 CSp solubility (weight percent)

Bitumen 76.66

Ash 0.02

Difference, 23.22

The filtered coal solution was ^{heated to 488 0} G (910 ⁰ F) and coked to produce a coke that was withdrawn from / from the coker and had the following properties:

Weight percent

volatile substances 10.9

Sulfur 0.27

Ash 0.13

jiiisen 0.036

Silicone _ 0.009

H ₂ O .. 0.112

Nickel 0.0073

Titanium. 0.013

founddium 0.00024

Boron (ppm) ..

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Example II

After the preparatory work mentioned in Example I, a bituminous coal, which had the same properties as the coal in Example I, and a distillate, which had an initial boiling temperature (converted to one atmosphere) of about 400 G (750 ⁰ P), was used in introduced the zone in the dissolving tank to achieve a 2: 1 ratio of solvent to carbon. The mixture was stirred while a pressure of 5 atmospheres and a temperature of 427 ° C (80 ° C) was maintained. The resulting coal solution was cooled ^(0]? 45O) to a temperature of about 233 'C and ^0, ..eitergeleitet via a filter, which was coated with a standard filter aid. The filtered coal solution had the following properties: "

Specific gravity (1OO ° / LOO ° F) 1.2525

Softening temperature ⁰ I ¹ (B + E) 212

Sulfur content (percent by weight) 0.44 Residual carbon (percent by weight)

Conradson 35 »9 ■ CSp solubility (weight percent)

Bitumen S8.35

Ash - OjO?

Difference 31.58

The filtered charcoal was solution was heated to 488 ⁰ C (910 ⁰ I) 'unc coked to produce a coke dec withdrawn from the coker and had the following properties:

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Weight percent Volatile substances 6.5-

Sulfur " 0.28

Ash- 0.12

Iron 0.025

Silicon 0.003

R ₂ O ₅ . 0.096

Nickel 0.0015

Titanium 0.014

Vanadium 0.00024,

Boron (ppm) 10M

The quality of the coke made according to the above examples corresponds to that of coke made from the best petroleum residues.

The vent from the coker was condensed and had the following properties:

specific weight

100/60 ⁰ P 1.148

25/25 ° C 1.160

viscosity

210 ⁰ F oentipoise 12.0

Oonradson carbon (weight percent) 0.18

Sulphonation residue none

Sulfur (weight percent) 0.38

Of the withdrawal of the coker had about 50>& an initial boiling point of more aid 400 ⁰ G (750 ⁰ F).

The extractable carbonaceous substances (except j Fiber l'olile), which in de.? powdered raw coal contain J beef, are therefore at elevated temperatures and pressures

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dissolved, with a high-boiling liquid solvent with high aromatic content is used, so that a solution of the extractable carbonaceous substances is formed, which is referred to as coal solution. the Fibrous carbon and the minerals are practically not influenced by the solvent and are in the carbon solution suspended. As long as the coal solution is in a free flowing state, it is filtered to remove the to separate suspended solids (including undissolved extractables). After that, the coal solution according to the invention heated to a temperature above the incipient coking and passed through a coking unit. The coke is removed from the coking unit, ■ and further units are supplied, which have a device for treating coke and a device for calcining contain. The vaporous products are withdrawn from the coking unit and introduced into a fractionation unit, in which they are separated into different fractions, e.g. a light fraction of gas and petrol, a medium and medium-weight fraction from oil distillates and a heavy - ■ --..-. Fraction with the residue. At least part of the high-boiling solvent with a high aromatic content Hydrocarbons that are used to dissolve or dissolve the extractable carbonaceous substances that are present in the raw coal are used by a fraction branched, which was recovered by the fractionation unit.

The ash from the coal solution can then in a conventional coking

unit, which is designed in the same way as the units that are used to coke petroleum for the production of Coke and other valuable products are used. Since the Properties of the solution are similar to those of coal

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tar pitch, which can be coked at low temperatures the ashed coal solution as a liquid starting material in Systems are used in which low-boiling tar distillates are available for the production of the solvent.

The filtered coal solution can be lightly coked in any conventional coking unit used to coke petroleum and in which the solution is heated to a temperature above its initial coking temperature and then coked to produce virtually ash-free coke, the a large proportion of highly volatile substances, e.g. from $ 4 to $ 26.

Preferably, the coal solution is coked in a delayed char unit consisting mainly of coke drums. When using such a unit, the filtrierte'Kohlelösung is heated to a temperature of about 850 ° to 1050 ⁰ I ¹ (450 ° to 56o ⁰ O) and fed to one of coke drums. The lower limit above the initial coking temperature to which the coal solution is heated is given by the upper limit of the volatile substances which are desired as coking product, normally about 8 to 16 $. The upper limit above the initial coking temperature to which the coal solution is heated is given by the lower limit of the volatile substances in the coking product, normally 6 to 8 / o, since coke has less than 6 '/ o volatile substances, extraordinary is hard and consequently difficult to remove from the coking tray.

The carbon solution can also be used in a contact carbonization unit can also be coked at higher temperatures (which consists of a reaction vessel consisting of a downward-flowing bed possesses special material on which the batch is spread

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and is coked) in order to obtain coking products that contain less than 6 io volatile substances. Higher temperatures are permitted if a contact coking unit is used, which does not have the practical limitation on removing the coke from a drum filled with coke with less than 6,000 volatiles. Furthermore, the contact coking methods require no Preheating the batch to a temperature above its initial coking temperature, since the temperature of the batch in the coker can be brought to a temperature above the initial coking point by the easily adjustable temperature of the contact particles.

The fractionation unit, which is preferably directly connected to the coking unit, is kept at such a temperature and pressure that it is possible to recover all or part of the highly aromatic liquid solvent for the solution of the coal. The initial boiling point (converted to one atmosphere) of such a solvent is between 650 ° and ⁰ (340 ° - 45O ⁰ E).

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Claims (2)

, Patent attorney Dr.-Ing. Wilinlsi Reicliel Fiankturt / MaUi-1 P 14 71.569. July 6th / 9th 1968 1471569 The lummus.Company .. RevS / Zg- 3859 P a t e η t a η s ρ r üc h e ! ./ Process for the production of asohe-free coke and valuable constituents from coal by coking a solution of bituminous coal, sub-bituminous carbon, lignite in »an organic solvent with a high boiling point, defl ur 0 hgeke η η ζ ei ch η et that as a coal solution a Mixture of charcoal in an organic solvent with a high content of aromatic substances and an initial boiling point of more than about 34O ⁰ G is used, that further, after separation of the dispensed mineral substances, the fibrous carbon and the inorganically bound sulfur, the carbon solution at a temperature is heated above the beginning coking temperature of the coal in the coal solution that is then coked in a manner known per se and that ash-free coke and vapors are collected ν. 2. The method according to claim 1, characterized in that the carbon solution is preheated to temperatures between 450 and 56O ⁰ C. 3 «The method according to claim 1 or 2, characterized in that the vapors to obtain a heavy distillate with an initial boiling point between; see about 340 and 45O ° C, preferably ⁰ to 400 G, which can be used if necessary as a solvent fractionated. New documents 909816/0246