DK153086B - PROCEDURE FOR FLUATING COAL - Google Patents

Description

in

DK 153086B

The present invention relates to a process for liquefying coal in a chemical manner without the use of high temperature and high pressure. For liquefaction, processes are known in which coal is decomposed or decomposed under the influence of high temperature and high pressure. However, in such processes, very large amounts of energy are needed to obtain liquidized product that can be utilized as an energy resource, and these processes are therefore not profitable. Furthermore, it is impossible to perform large scale liquefaction of coal in these processes.

It is therefore the object of the present invention to provide a new method for liquefying coal which does not exhibit these deficiencies.

DK 153086B

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It has now been found that Jean is made charcoal liquid with a yield of up to 80% of its original weight by a process where coal is crushed into grain form and soaked in an aqueous solution of sodium hydroxide so that the solution penetrates into the coal material. then pulverized on a pulverizer after it has been removed and dried to a particle size of less than 100 mesh; the coal powder thus obtained is then mixed with an aqueous solution containing sodium hydroxide and an organic carboxylic acid, stirring the mixture, and then kept still for a sufficient time until the coals show signs of liquefaction, whereupon the mixture is heated to a temperature of 90-150 ° C with further addition of water.

Accordingly, the invention relates to a process for liquefying coal which is characterized by impregnating granulated coal with an aqueous solution of sodium hydroxide by soaking it in this solution, after which the coal thus treated, after it has been removed and dried, is pulverized. to a particle size below 100 mesh and the thus-obtained coal powder is mixed with an aqueous solution containing sodium hydroxide and an organic carboxylic acid, after which the mixture is kept still for a sufficient time until the coal shows liquefaction and finally the mixture is heated to a temperature of 90-150 ° C. with further addition of water thereto.

The liquefied coal product obtained by the process of the invention is composed of substances which are particularly useful as fuel oil and as a starting material for many chemical products.

In the process of the invention, any kind of coal, e.g., smoke-free coal, bituminous coal, lignite, lignite and other kinds of coal, can be used.

Description of preferred embodiments

In the method according to the invention, the granulated coals can preferably be delivered from conventional crushing apparatus having an average grain size of no more than approx. 3 cm, in particular approx. 2 cm.

As an aqueous solution of sodium hydroxide to soak the granulated coals, it is particularly preferred to use a solution prepared by dissolving sodium hydroxide in demineralized water. The concentration of this solution is convenient in the range

DK 153086B

3 1-5%, especially 2-4% and especially a concentration of approx. 3%.

It is particularly preferred to use the solution in a weight amount equal to the weight amount of granulated coal. The period during which the granulated coal is soaked in the sodium hydroxide solution varies depending on the grain size of the granulated coal and the concentration of the solution and similar factors, usually it takes more than a few hours, most often about 10 hours or more.

The coals that have been subjected to the soaking treatment are then dried, preferably as well as possible. For this, drying can be done in a conventional dryer, but it is also recommended to do solar drying.

For pulverizing the coal after drying, it is sufficient to use a conventional pulverizer. The average grain size of the resulting coal powder is preferably below 100 mesh (JIS A 1102) and a grain size in the coal powder is particularly preferred around 150 mesh.

The aqueous solution for treating the pulverized coal in accordance with the invention should contain sodium hydroxide and an organic carboxylic acid, and preferably in a molar ratio of 0.5: 1.5 to 1.5: 0.5, particularly preferred to have a molar ratio of these two components between 0.9: 1.1 and 1.1: 0.9. The total content of sodium hydroxide and organic carboxylic acid in the solution should preferably be at most approx. In this case, the use of demineralized water for preparing the solution is also recommended. The amount of powdered charcoal which can be mixed with this solution may preferably be 0.5% by weight. For example, with regard to the organic carboxylic acid contained in the solution, it is, for example, a lower carboxylic acid (i.e., a low carbon atom) which is essentially liquid at normal temperature and has a boiling point of in the range 5Q-170 ° C such as formic acid, acetic acid, propionic acid or butyric acid; examples of which may also be mentioned saturated and unsaturated aliphatic monocarboxylic acids such as acrylic acid and methacrylic acid, aliphatic polycarboxylic acids such as malonic acid, succinic or adipic acid, and aromatic carboxylic acids, as well as aromatic carboxylic acids. proved to be useful in using formic acid or acetic acid.

The duration of the standstill after the mixture of the powdered

DK 153086B

4 prepared coal with the solution of sodium hydroxide and carboxylic acid before the start of heating corresponds to the time the coals need to be denatured and to exhibit the first signs of liquefaction, and this time period is generally in the range of about 1 5 to approx. 10 hours.

Immediately after the coals show signs of liquefaction, an additional amount of demineralized water, optionally in a separate container, is added in an amount of 0.3-1 parts per minute. part powdered coal. After the additional addition of demineralized water, the mixture is heated to a temperature of 90-150 ° C, preferably 110-120 ° C. Although the duration of the heating depends on the temperature used, the time period during which the heating takes place is generally in the range of from approx. 30 minutes to approx.

2 hours.

After the heat treatment it can be found that up to approx. 80% of the initially present coal is liquefied and floats on the aqueous layer. The separation of this liquefied product can be easily carried out in a conventional manner.

It is possible to promote the liquefaction of coal by adding an appropriate amount of phenol or naphthalene before heating. These compounds may have the function of promoting an oxidation reaction during the liquefaction of coal.

The liquefied coal product produced by the process of the invention can either be used as such for fuel or can be subdivided into the various useful ingredients.

As described above, the liquefaction process for coal according to the invention exhibits many advantages since it does not require high temperatures or high pressures and since the apparatus used is very simple; In addition, all the individual steps in the process are quite simple so that the process can be carried out very economically and is suitable for large-scale implementation.

In the following, the process of the invention will be described in more detail by way of example.

Example

Bituminous coal is crushed using a grain hammer crusher with an average grain size of 2 cm. 10 kg of these granu- 5

DK 153086B

Charged charcoal is placed in a container of 180 liters capacity containing an aqueous solution prepared by dissolving 300 g of sodium hydroxide in 10 kg of demineralized water. After filling, the mixture is kept still for 20 hours. Then the coals are taken out and dried in the sun for 24 hours. The dried granulated coal is then pulverized in a pulverizer to an average particle size of 150 mesh. Place 10 kg in an aqueous solution prepared by dissolving 300 g of sodium hydroxide and 400 g of acetic acid in 10 kg of demineralized water, and the mixture is stirred until a state of good mixing is obtained. Then keep the mixture still for 10 hours. The mixture is then transferred to a kettle and after the addition of 5 kg of demineralized water, the mixture is boiled for 1 hour at a temperature of 120 ° C. An oily product is obtained as the upper layer of the kettle and in an amount of 7.92 kg.

The yield of the liquefaction of coal is estimated at approx. 8Q%. Analysis data for the product thus prepared are as follows:

Density (15/4 ° C) approx. 0795

Flash point f ° C) 58

Dynamic viscosity (30 ° C, cST) 1.45

Sulfur content (weight) <0.01

Temperature at 50% distillation 198.4 ° C

The drawing shows a gas chromatogram recorded by the product.

As can be seen, the product as a major constituent contains relatively low molecular weight paraffins.

Claims (8)

A process for liquefying coal, characterized by impregnating granulated coal with an aqueous solution of sodium hydroxide by soaking in this solution, extracting and drying the thus impregnated granulated coal, pulverizing them to a particle size of less than 100 mesh, mixing the thus obtained. coal powder with an aqueous solution containing sodium hydroxide and an organic carboxylic acid, keeps the mixture still for a sufficient time until the coals show signs of liquefaction and finally the mixture warms to a temperature of 90-120 ° C with further addition of water. Process according to claim 1, characterized in that the average grain size of the granulated coal used as a starting material is not more than 3 cm and that the average particle size of the powdered coal is approx. 150 mesh. Process according to claim 1 or 2, characterized in that a carboxylic acid having a low number of carbon atoms is used as a carboxylic acid. Process according to any one of claims 1-3, characterized in that the concentration of the aqueous solution of sodium hydroxide for the soaking of the granulated coals is in the range of 1-5%, preferably 2-4% and in particular approx. 3%. Process according to any one of claims 1-4, characterized in that the molar ratio of sodium hydroxide to carboxylic acid in the aqueous solution for the treatment of the pulverized coal is between 0.5: 1.5 and 1.5: 0.5. in particular between 0.9: 1.1 and 1.1: 0.9. Process according to any one of the preceding claims, characterized in that the total content of sodium hydroxide and carboxylic acid in the solution for the treatment of the powdered coal is not more than 10% by weight, in proportion to the amount of water. Process according to any one of the preceding claims, characterized in that the amount of supplementary water added is 0.3-1 part by weight per minute. parts by weight of powdered coal. DK 153086 B Process according to any one of the preceding claims, characterized in that phenol or naphthalene is added before heating the pulverized coal mixture.