EP3085755A1 - Method and system for generating syngas and pyrolysis from coal of different grain sizes - Google Patents

Abstract

Process for the conversion of coal into synthesis gas and by-products, such as tar and oil, whereby the coal is separated into a coarse and a fine fraction, the coarse fraction in a fixed bed pressure gasification, the fine fraction in a pyrolysis process, and the resulting tar, oil and naphtha-containing products are combined and mixed.

Description

Field of the invention

1. a) Bereitstellen von Kohle,
2. b) Trennung der Kohle in einen grobkörnigen und einen feinkörnigen Teil durch Anwendung eines mechanischen Trennverfahrens,
3. c) Umwandlung des grobkörnigen Teils der Kohle in Synthesegas, Teer, Öl, Gaskondensat und Asche in einer Anlage, umfassend einen ersten Anlagenteil mit einem Festbettdruckvergasungsreaktor, in dem die Kohle unter Einsatz von Sauerstoff und Wasserdampf zu einem hauptsächlich Kohlenmonoxid und Wasserstoff umfassenden Rohsynthesegas vergast wird und wobei Asche erzeugt wird, einen zweiten Anlagenteil, der eine an den Reaktor angeschlossene Anlage zur Kühlung und Wäsche des Rohsynthesegases umfasst, die gekühltes Synthesegas und mit Teer und Öl beladenes Gaskondensat erzeugt und einen dritten Anlagenteil zur mechanischen Abtrennung von Teer und Öl aus dem Gaskondensat, wobei ein überwiegend teerhaftiger Produktstrom, ein überwiegend ölhaltiger Produktstrom, ein überwiegend staub- und teerhaltiger Produktstrom und ein von Teer und Öl abgereicherter Gaskondensatstrom zur weiteren Verarbeitung aus dem dritten Anlagenteil ausgeleitet wird.

The invention relates to a process and a plant for the conversion of coal into synthesis gas, tar, oil, naphtha, gas condensate and ash, comprising the process steps:

1. a) provision of coal,
2. b) separation of the coal into a coarse-grained and a fine-grained part by using a mechanical separation process,
3. c) converting the coarse-grained portion of the coal into syngas, tar, oil, gas condensate and ash in a plant comprising a first plant section with a fixed bed pressure gasification reactor in which the coal is gasified using oxygen and water vapor to form a raw synthesis gas comprising primarily carbon monoxide and hydrogen and wherein ash is produced, a second plant part comprising a plant connected to the reactor for cooling and scrubbing the raw synthesis gas, the cooled syngas and produced with tar and oil gas condensate and a third part of the plant for the mechanical separation of tar and oil from the gas condensate , wherein a predominantly tarry product stream, a predominantly oily product stream, a predominantly dust and tar-containing product stream and one of tar and oil depleted Gas condensate stream is discharged from the third part of the plant for further processing.

State of the art

Such a method is known. It is basically in Ullmann's Encyclopedia of Industrial Chemistry, Sixth Edition, Vol. 15, Gas Production, Chapter 4.4 described. The part of the plant referred to in the jargon "Teerscheider" for the mechanical separation of tar and oil from the gas condensate is in Ullmann's Encyclopedia of Industrial Chemistry, 4th Edition, Vol. 14, Coal, Gas Production, Chap. 6.1.1 described.

A prerequisite for the trouble-free operation of the process is that the bed of the fixed bed pressure gasification reactor can be flowed through to a sufficient extent and evenly distributed by the process gases, oxygen and water vapor. To achieve this, the fine-grained fraction must be separated from the coal before use in the reactor. The separated fine-grained fraction of the coal is used in many cases as fuel for process steam generation. However, it happens that the fine-grained portion of the coal is so large as to be up to 50% by weight so that it exceeds the coal requirement for process steam generation and it is difficult to economically otherwise use the excess fine-grained coal. Another disadvantage of this use as fuel is that it does not give the opportunity to recover valuable products, such as tar and oil, from this part of the coal.

Description of the invention

In the process of the invention described in more detail below, the disadvantages of the prior art are overcome, in which at least part of the fine-grained fraction of the coal is converted by pyrolysis into coke and tar, oil and naphtha vapors, the coke being sent for further use and the tar and oil vapors are condensed and the tar is added to the predominantly tar-containing product stream from step c) and the oil is added to the predominantly oil-containing product stream from step c) and the naphtha steam is partly fed to another use and condensed to the other part and the won liquid naphtha is added to the predominantly oily product stream from step c).

In this way, the yield of valuable products, such as tar and oil, is increased from the coal, since the fine-grained portion of the coal is no longer merely burned or discarded, as is common in the prior art. By selective selection from the pyrolysis methods known to those skilled in the art, which are sometimes referred to in the literature as carbonization, and by targeted, familiar to the expert process control, the quality of the pyrolysis tar, oil and naphtha can be influenced. As a result of the inventive mixing of the tar and oils originating from the gasification and from the pyrolysis, the quality of the tar and oil produced by the process according to the invention can also be influenced in a targeted manner.

For example, the LURGI-RUHRGAS smoldering process is suitable for the invention, cf. Ullmanns Encyklopadie der technischen Chemie, 4th Edition, Vol. 3, p. 463 ,

For the purposes of this invention, smoldering is understood as pyrolysis. Under pyrolysis conditions physicochemical conditions are understood that allow a thermochemical cleavage of organic compounds under largely non-oxidative conditions. They are known from the prior art to include the setting of high temperatures and the substantial absence of oxidants, so for example, the heating under exclusion of air. The pyrolysis conditions will suitably be selected by the person skilled in the art depending on the feedstock to be treated.

Preferred embodiments of the invention

A particular embodiment of the invention is characterized in that the fine-grained part of the coal mentioned in step b) of claim 1 is defined by a particle size of less than 5 mm. The particle size is adjusted by sieving with a sieve of mesh size 5 mm. At this boundary between fine-grained coal fraction being pyrolyzed and coarse-grained fraction being in fixed bed pressure gasification reactor is processed, there is a good flow through the fixed bed in the gasification reactor in many types of coal.

A further particular embodiment of the invention is characterized in that the tar, oil and naphtha vapors obtained by pyrolysis are cooled in such a way that the tar and oil vapors completely condense and the naphtha vapor condenses in part and the liquid tar, which is thereby obtained, Oil and naphtha phase is introduced into the third part of the plant mentioned in step c) and therein into the loaded with tar and oil gas condensate and wherein the non-condensed part of the naphtha steam is supplied to another use. The advantage of this Ausgestattung is that the condensation of the pyrolysis products can take place near the pyrolysis apparatus, whereby a transport of the vapors over long distances through lines is avoided.

A further particular embodiment of the invention is characterized in that the tar, oil and Naphtadämpfe obtained in the pyrolysis in the third plant in step c) is introduced into the contained therein, loaded with tar and oil gas condensate phase, wherein tar and Condensing oil vapors completely and are separated from the gas condensate together with the tar and oil formed in step c) and wherein the naphtha steam is partially condensed and separated together with the oil from the gas condensate and the uncondensed part of the naphtha steam is supplied to another use. The advantage of this embodiment is that no separate system for the condensation of vapors is needed.

A further particular embodiment of the invention is characterized in that the coke produced in pyrolysis according to step d) of claim 1 is used at least partly as heat carrier for the production of the water vapor used for the gasification carried out in step c), claim 1, in the fixed-bed pressure gasification reactor becomes. This in-house use of the coke avoids costs of distribution and transportation to more remote uses.

Another particular embodiment of the invention is characterized in that the non-condensed part of the naphtha steam is used as a heat carrier in the pyrolysis of the fine-grained part of the coal. This measure increases the energy efficiency of the process.

Ausführungsbelsplel

Other features, advantages and applications of the invention will become apparent from the following description of an embodiment and numerical example and the drawings. All described and / or illustrated features alone or in any combination form the subject matter of the invention, regardless of their combination in the claims or their dependency.

Fig. 1

ein Blockschema des erfindungsgemäßen Verfahrens.

It shows the only figure

Fig. 1

a block diagram of the method according to the invention.

The inventive method will be described below with reference to the drawing Fig. 1 be explained.

The coal 1 provided is in a mechanical separator 2, z. As a screening machine, separated into a coarse-grained portion 3 and a fine-grained portion 4. The coarse-grained portion 3 of the coal is gasified in a first plant part 5 using oxygen 6 and steam 7 to produce synthesis gas 8, wherein ash 9 is generated. The raw synthesis gas 8 is transferred from the first part of the plant 5 into a second part of the plant 10 where it is cooled and washed, and is fed as synthesis gas 11 to a further treatment. During treatment in the second part of the plant 10, gas condensate 12 charged with tar, oil and dust is formed.

The fine-grained portion 4 of the coal 1 is on the one hand part 4a of a pyrolysis treatment 18, and on the other part 4b of another use, for. B. the use as fuel. In the pyrolysis treatment 18, with the metered addition of air 19, the coal is converted into coke 20, carbonization products 21 and exhaust gases 22. Of the produced coke 20 is fed to a plant for generating steam 23, which is fed with water 24. The generated steam 7 is introduced into the first part of the plant 5. The exhaust gases 22, which are also produced in the pyrolysis 18 and also contain naphtha, are fed to a further treatment. Furthermore, in the pyrolysis treatment, carbon blacks 21 are produced, which mainly consist of tar, oil and naphtha and, depending on the process conditions used in the pyrolysis and cooling treatment, are in gaseous or liquid form.

The loaded gas condensate 12 and liquefied by cooling carbonization products 21 are transferred to the system part 13 and mixed therein. In this system cell 13 is mechanically, for. Example by means of a settling tank, which is often referred to as a tar separator, a predominantly tarry product stream 14, a predominantly oily product stream 15, which also contains naphtha, and a dust-containing and tarry product stream 16 separated from the gas condensate. The purified gas condensate 17 is fed to a further treatment.

Industrial Applicability

The invention provides a process for the conversion of coal into synthesis gas and valuable by-products, such as tar, in which also the fines of the coal are effectively used for the production of the by-products.

LIST OF REFERENCE NUMBERS

1

coal

2

separator

3

Coarse-grained coal

4

Fine-grained coal, a for pyrolysis, b for other uses

5

First plant part, e.g. Fixed bed pressure gasification

6

oxygen

7

Steam

8th

raw synthesis gas

9

ash

10

Second part of the system, cooling and laundry

11

raw synthesis gas

12

Loaded gas condensate

13

Third piece of equipment, e.g. Teerscheider

14

Tar-containing product stream

15

Oil and naphtha-containing product stream

16

Dust and tar-containing product stream

17

gas condensate

18

pyrolysis

19

air

20

coke

21

carbonization

22

Exhaust gases, also containing naphtha

23

steam generation

24

water

Claims (7)

Process for the conversion of coal into synthesis gas, tar, oil, naphtha, gas condensate and ash, comprising the process steps: a) provision of coal, b) separation of the coal into a coarse-grained and a fine-grained part by using a mechanical separation process, c) converting the coarse-grained portion of the coal into syngas, tar, oil, gas condensate and ash in a plant comprising a first plant section with a fixed bed pressure gasification reactor in which the coal is gasified using oxygen and water vapor to form a raw synthesis gas comprising primarily carbon monoxide and hydrogen and wherein ash is produced, a second plant part comprising a plant connected to the reactor for cooling and scrubbing the raw synthesis gas, the cooled syngas and produced with tar and oil gas condensate and a third part of the plant for the mechanical separation of tar and oil from the gas condensate , wherein a predominantly tar-containing product stream, a predominantly oily product stream, a predominantly dust and tar-containing product stream and a depleted of tar and oil gas condensate stream is discharged from the third part of the plant for further processing, characterized in that d) at least part of the fine-grained part of the coal obtained in step b) is converted into coke and tar, oil and naphtha vapors by pyrolysis, wherein the coke is fed to further use and the tar and oil vapors are condensed and the tar the predominantly tar-containing product stream from step c) and the oil is admixed to the predominantly oil-containing product stream from step c) and the naphtha steam is partly used for another purpose and condenses to the other part and the liquid naphtha obtained is added to the predominantly oil-containing product stream from step c) is added. A method according to claim 1, characterized in that the fine-grained part of the coal mentioned in step b) of claim 1 is defined by a particle size of less than 5 mm. A process according to claim 1 or 2, characterized in that the recovered tar, oil and naphtha vapors are cooled so that the tar and oil vapors fully condense and the naphtha vapor is partially condensed and the resulting liquid tar, oil and naphtha phase is introduced into the third part of the plant mentioned in step c), claim 1, and therein into the tar and oil-laden gas condensate, and wherein the non-condensed part of the naphtha steam is put to another use. A method according to claim 1 or 2, characterized in that the tar, oil and Naphtadämpfe obtained in the pyrolysis in the third part of the plant mentioned in step c) of claim 1 is introduced into the therein, loaded with tar and oil gas condensate phase Completely condense tar and oil vapors and are separated from the gas condensate together with the tar and oil formed in step c) of claim 1 and wherein the naphtha steam is partially condensed and separated together with the oil from the gas condensate and the non-condensed part of Naphtha steam another use is supplied. Method according to one of the preceding claims, characterized in that the coke produced in pyrolysis according to step d) of claim 1 at least partly used as a heat carrier for the production of the water vapor used for the according to step c), claim 1, carried out in the fixed bed pressure gasification reactor gasification becomes. Method according to one of the preceding claims, characterized in that the non-condensed part of the naphtha steam is used as a heat carrier in the pyrolysis of the fine-grained part of the coal. Plant for the conversion of coal into synthesis gas, tar, oil, naphtha, gas condensate and ash comprising the plant parts: - Device for mechanical separation of the coal in a coarse and a fine-grained fraction - Device for fixed-bed pressure gasification of the coarse-grained portion of the coal to a raw synthesis gas to form ash - Device for cooling and scrubbing the raw synthesis gas to form gas condensate - Teerscheider for the mechanical separation of product streams from the gas condensate - Device for pyrolysis of the fine-grained fraction of coal - Apparatus for steam generation, which is operated with the coke produced in the apparatus for pyrolysis Furthermore comprising the devices for transferring the intermediate products between the plant parts,
characterized in that the device for pyrolysis is connected to the tar separator with a carbonization transfer device and the steam generation device is connected to a vapor transfer device with the fixed bed pressure gasification device.

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