JPS5824470B2 - Raw coke with caking properties - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses heavy hydrocarbons, such as atmospheric distillation residue oil or vacuum distillation residue oil of petroleum, as a raw material and coking under specific conditions. It concerns green coke and seeks to provide a suitable alternative to coking coal for producing strong coke for steelmaking blast furnaces.

Japan is not blessed with coking coal resources for blast furnace coke, and relies on imports for most of it, but the recent worldwide trend of tightening coking coal has led to serious concerns about the supply of coking coal.

As a result, many steel mills have begun to use raw coke obtained by coking petroleum-based residual oil as part of coking coal.

However, conventional methods such as delayed coking and fluid coking, which are known as methods for coking petroleum residue oil, etc.
The raw coke obtained by methods such as coking has progressed to a state where it is almost insoluble in pyridine, and because it has almost no caking property or fluidity, it cannot be used with other coking coals. There is a limit to how much carbon can be mixed with carbon dioxide, and it has only been used as a carbon source with a low ash content.

Normally, coking coal is required to produce strong coke for steelmaking blast furnaces.

This caking property is a property that allows strong coke to be obtained by carbonizing raw coal, and is also called coking property.

Does the caking property referred to in this application mean the coking property (bracket 2) in the caking property section of the Chemical Encyclopedia (Kyoritsu Shuppan Co., Ltd., Vol. 6, page 893, published in 1960), that is, the ability to form strong coke? It is used as a measure to show whether

As mentioned above, raw coke with excellent caking properties and fluidity is produced from petroleum residue oil, etc., that is, artificial caking coal, which is equivalent to natural caking coal and is a raw material for strong coke for steelmaking blast furnaces. The method is hitherto unknown.

The present inventors have conducted research on artificial caking coal, which is a raw material for strong coke for steelmaking blast furnaces, using heavy hydrocarbons such as petroleum distillation residue oil; This book was based on the discovery that raw coke containing 50 to 90% pyridine-insoluble content (extracted residue from a Soxhlet extractor) obtained by coking heavy hydrocarbons under specific conditions exhibits good caking properties. The invention has been achieved.

That is, the present invention deals with heavy hydrocarbons at 380 ml under normal pressure.
It is a raw coke which has caking properties and contains 50 to 90 wt% of pyridine insoluble matter, which is obtained by coking at a temperature in the range of 3 to 420 degrees Celsius for 3 to 5 hours.

An object of the present invention is to provide the above-mentioned raw coke.

Raw materials for obtaining the raw coke having caking properties of the present invention include petroleum-based vacuum distillation residue oil, asphalt as a source of the residue oil using a light hydrocarbon solvent such as propane, petroleum oil such as pyrolysis residue oil, catalytic cracking oil, etc. In addition, heavy hydrocarbons such as natural asphalt, coal tar, shale oil, and tar sand oil can be used.

The coking temperature for obtaining the raw coke having caking properties of the present invention can be within the temperature range adopted in the conventionally known dilate coking method, that is, around 410 to 490 °C, but the raw coke produced In order to make the amount of pyridine insoluble matter in the range of 50 to 90 wt%,
Coking can be carried out by lowering the coking temperature close to the temperature at which the feedstock starts to decompose (for example, in the case of vacuum residue oil of Kuwait crude oil, this is around 380° C.).

That is, the raw materials are heated at 380°C to 420°C under normal pressure.
A raw coke prepared by heat coking at a temperature in the range of 3 to 5 hours and containing 50 to 90 wt% of pyridine insoluble matter is suitable as a substitute for natural coking coal.

If the temperature exceeds 420°C, for example at 450°C, coking reaction for 2 hours under normal pressure will only yield raw coke that does not soften at all, and even at 420°C, coking for less than 2 hours will result in poor caking performance. You can only get raw coke that does not have

As mentioned above, raw coke obtained by the conventional coking method is hardly soluble in pyridine, but in the present invention, the amount of pyridine insoluble matter is 50 to 90 wt%, which causes caking in the produced raw coke. This is an important point in preserving gender.

In the present invention, the amount of pyridine insoluble matter is 50 to 90 wt%.
There is a tendency for the caking property to decrease outside the range of .

That is, a raw coke with a pyridine insoluble content of less than 50 wt% has high fluidity but a reduced caking property, and a raw coke with a pyridine insoluble content of more than 90 wt% has a decrease in both fluidity and caking property.

As mentioned above, the raw coke of the present invention has more advantageous properties than natural products in terms of fluidity, and since the amount of pyridine insoluble matter in the raw coke is in the range of 50 to 90%, its production This method can significantly expand the coking temperature range to lower temperatures than the conventional method, and it is possible to use a heating tube in the heating tube to preheat the raw material to the predetermined temperature required for the reaction, which was a major operational problem in the conventional coking process. It has the advantage of preventing caulking.

Example 1 Vacuum distillation residue oil of Kuwaiti crude oil (softening point: 39°C, penetration: 218 @ 25°C, residual coal: 17.5 wt%) was mixed into an internal volume of 200
The reaction time was 5 hours at a reaction temperature of 420°C using a reaction apparatus set up so that the pressure inside the system could be reduced by a vacuum pump from the very end of the cracked liquid gas distillation section equipped with a cooling tube. , caulking was performed with a pressure cuff of 60 mmHg.

Table 1 shows the yield and properties of the raw coke obtained here.

1 Example 2 Kuwait vacuum residual oil was extracted with propane, and 25 wt% of aliphatic hydrocarbons were removed. Propane asphalt (softening point: 48°C, penetration (25°C): 44, residual carbon: 24.9 wt%) ) in the same manner as in Example 1, at 420°C and normal pressure.
Time caulking was performed and the results shown in Table 1 were obtained.

Comparative Example 1 (When Kuwait vacuum residual oil was coked for 2 hours at 450° C. and normal pressure in the same manner as in Example 1), the results are shown in Table 1.

Comparative Example 2 The naphtha cracked heavy oil produced as a by-product from the naphtha cracking process was used in Example 1.
Caulking was performed in the same manner as above at 430°C and normal pressure for 5 hours.
The results shown in Table 1 were obtained.

1 Comparative Example 3 The same Kuwait propane asphalt used in Example 2 was treated in the same manner as in Example 1 at 420°C and normal pressure for 1.
Coking was performed for 5 hours, and the results shown in Table 1 were obtained.

[Brief explanation of the drawing]

Figure 1 shows the relationship between the pyridine-insoluble content of raw coke and the coke button index.

Claims (1)

[Claims] 1. One or two types of residual oil from vacuum distillation of crude oil and asphalt as a solvent source of the residual oil are used as raw materials, and the raw materials are heated under normal pressure for 38 hours.
A raw coke having caking properties in which the pyridine insoluble content is reduced to 50 to 90 wt% by coking at a temperature in the range of 0°C to 420°C for 3 to 5 hours.