JPS582996B2 - Heavy oil gasification method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for gasifying heavy oil such as crude oil, heavy oil, vacuum residue oil, etc. by continuous catalytic cracking to obtain high-quality fuel gas.

Producing high-quality fuel gas by gasifying heavy oil, which has low commercial value, is an industrial option from the standpoint of effective resource utilization and from the standpoint of pollution control since fuel gas is easy to desulfurize. This is extremely significant.

BACKGROUND ART Conventionally, as one of this type of gasification methods, a two-column type catalyst particle circulation flow type gasification method having a gasification zone and a regeneration zone is known.

In this method, carbon substances such as soot and tar that are produced as by-products together with the produced gas in the gasification zone adhere to the surface of the catalyst particles and reduce the catalytic activity. be burned.

The regenerated catalyst particles are then sent to the gasification zone again.
Involved in catalytic cracking gasification reactions.

Further, the amount of heat required for the gasification reaction is supplied by the circulation of catalyst particles heated by complete combustion of carbonaceous substances such as soot and tar in the regeneration zone.

By the way, it has been found that such a conventional gasification method has a problem in that the gasification efficiency and the calorific value of the generated gas decrease.

That is, in this method, the combustion of carbonaceous material in the regeneration zone is carried out in the presence of excess oxygen, so that the metal element or metal oxide contained in the catalyst particles becomes oxidized or overoxidized, and gasification occurs in this state. sent to the obi,
In the gasification zone, there are reducing gases such as hydrogen and carbon monoxide generated by the catalytic cracking gasification reaction, so the metal oxides or metal oxides in the catalyst particles sent from the regeneration zone are not converted into reducing gases. As a result of this reaction, hydrogen and carbon monoxide become nonflammable water (steam) and carbon dioxide, respectively, which reduces the gasification efficiency and calorific value of the produced gas, and furthermore, because the produced gas contains a large amount of CO2 components, the following This creates a problem in that the purification process is troublesome.

The present invention aims to solve the problems in the conventional methods described above, and aims to provide a gasification method that can improve the gasification efficiency and the calorific value of the generated gas.

The present invention achieves these objects by reducing the soot produced as a by-product when heavy oil is catalytically cracked and gasified in the gasification zone.
Catalyst particles with tar etc. attached are sent to a fluidized regeneration zone, and in this regeneration zone, carbonaceous matter such as soot and dirt is removed by air or oxygen gas containing less oxygen than the amount of oxygen required for complete combustion of the carbonaceous matter. The combustible gas generated in the regeneration zone is converted into combustible gas containing carbon monoxide, and the combustible gas generated in the regeneration zone is combusted in a combustion zone outside the regeneration zone, and the sensible heat is used to generate combustible gas within the gasification zone, within the regeneration zone, or both. The feature is that the catalyst particles are heated indirectly.

According to a preferred embodiment of the present invention, a gasification zone, which is a fluidized bed of catalyst particles containing simple metals or metal oxides, is maintained at a pressure of 1 to 50 atm and a temperature of 600 to 1000°C; Introducing heavy oil, which is a raw material oil, and steam having a weight ratio of 0.5 or more to the heavy oil,
Heavy oil is gasified by catalytic cracking, and carbonaceous substances such as soot and sludge generated along with the generated gas adhere to the surface of catalyst particles and are sent together with the catalyst particles to a regeneration zone, where the carbonaceous substances are completely removed. Air or oxygen containing less oxygen than is required for combustion is converted into a combustible gas containing carbon monoxide.

The regenerated catalyst particles are sent to the gasification zone and participate in the gasification reaction again, while the combustible gas generated in the regeneration zone is led to the combustion zone, where it is added with fuel gas if necessary. The combustion gas is completely combusted in excess air, and the combustion gas is led to the gasification zone or the regeneration zone or both the gasification zone and the regeneration zone in order to exchange its sensible heat for heating the catalyst particles.

In the present invention, oxygen in the regeneration zone is preferentially consumed to convert carbonaceous substances such as soot and tar into combustible gas containing carbon monoxide, so that metals and metal oxides in catalyst particles are consumed preferentially. is rarely oxidized or overoxidized, and therefore almost no reaction occurs between the produced gas and the oxygen in the catalyst particles in the gasification zone.

As a result, high-calorie gas containing little carbon dioxide is produced.

Next, embodiments of the present invention will be described with reference to the drawings.

Of course, the accompanying drawings are for the purpose of making it easier to understand the features of the present invention, and the present invention is not limited thereby.

In the drawing, heavy oil, which is a feedstock oil, is supplied from a nozzle 4 alone or mixed with steam introduced through a pipe 5 to a fluidized bed of catalyst particles in a gasification zone 1 in a gasification tower A.

A fluidizing gas, e.g. steam, is supplied to the gasification zone through pipe 14.

The raw material oil supplied to gasification zone 1 has a pressure of 1 to 50 atm,
The gas is gasified at a temperature of 600 to 1000° C., and the generated gas becomes an updraft along with unreacted water vapor and a portion of by-product carbonaceous matter such as soot and tar, and is sent through the pipe 6 to the purification process.

Most of the carbonaceous substances such as soot and tar produced by the gasification reaction adhere to the surface of the catalyst particles, pass through the pipe 9 together with the catalyst particles, and pass through the pipe 10 together with the fluidizing gas from the pipe 11, such as water vapor, to the regeneration tower B. It is fed into the bottom of the regeneration zone 2 inside.

In the regeneration zone, the carbonaceous material fed by the gasification zone together with the catalyst particles is converted into combustible gas containing carbon monoxide by air or oxygen from the pipe 7.

The catalyst particles from which carbonaceous matter has been removed from the surface pass through the pipe 12 to the pipe 1.
4 is returned to the bottom of the gasification zone via pipe 13.

On the other hand, the combustible gas generated in the regeneration zone is sent to the combustion zone 3 in the combustor C through the pipe 8.

The combustible gas is now completely combusted by air from pipe 15, if necessary together with the fuel gas from pipe 16, and the resulting hot combustion gases are led via pipe 17 to a heat exchanger 18 in gasification zone 1. After exchanging heat with the catalyst particles and supplying the heat necessary for the gasification reaction, the gas is discharged from the pipe 19.

Although not shown in the drawing, the heat exchanger 18 can be installed in the regeneration zone 2 to exchange heat with the catalyst particles, or the heat exchanger 18 can be installed in both the gasification zone 1 and the regeneration zone 2. It can also be installed to exchange heat with catalyst particles.

Next, examples of the present invention and comparative examples based on conventional methods will be described in order to demonstrate the effects of the present invention as described above.

Using Gatsuchisaran vacuum residual oil with the properties shown in Example Table 1 as a raw material, it was heated externally using an electric furnace and had an inner diameter of 41 mm and a length of 6.
Gasification was carried out under the operating conditions shown in Table 2 using an experimental apparatus consisting of a 00 mm gasification tower and a regeneration tower, in which catalyst particles circulated through both towers.

As a result, a gas with the following composition was obtained.

Comparative Example Using the experimental equipment used in the above example, Table 1
The Gatsuchisaran vacuum residue oil shown in Table 2 is used as the raw material, and the regeneration tower air supply rate is set to 1.0 to 1 among the operating conditions shown in Table 2.
．． A gasification experiment was conducted at a rate of 5 Nm3/hr and other conditions being the same.

As a result, a gas with the following composition was obtained.

When this comparative example is compared with the above-mentioned examples, it is clear that the gasification method of the present invention can produce a high calorific value gas with a composition that is low in carbon dioxide and high in hydrogen and carbon monoxide. It will be understood.

[Brief explanation of drawings]

The drawing is a schematic part of an example of a device for carrying out the method of the invention. A... Gasification tower, B... Regeneration tower, C.
... Combustor, 1 ... Gasification zone, 2 ...
...Regeneration zone, 3... Combustion zone, 4...
Raw material supply nozzle, 5, 6, 7, 8, 9, 10, 11, 1
2, 13, 14, 15, 16, 17... tube, 1
8... Heat exchanger, 19... Tube.

Claims (1)

[Scope of Claims] 1. In a method of gasifying heavy oil such as vacuum residual oil by bringing it into contact with catalyst particles containing an elemental metal or a metal oxide, in a gasification zone where the fluidized catalyst particles are present. When heavy oil is gasified, the catalyst particles with soot, tar, etc. that are produced as by-products are sent to a fluidized regeneration zone, and in this regeneration zone, carbonaceous substances such as soot and tar are removed by the amount of oxygen required for complete combustion of the carbonaceous substances. Converting the catalyst particles to a combustible gas containing carbon monoxide with air or oxygen gas containing less oxygen, returning the regenerated catalyst particles to the gasification zone, and burning the combustible gas in a combustion zone outside the regeneration zone. A method for gasifying heavy oil, characterized in that the sensible heat indirectly heats catalyst particles in a gasification zone, a regeneration zone, or both. 2 The gasification zone is 1 to 50 atm. The method for gasifying heavy oil according to claim 1, which is performed at a temperature of 600 to 1000°C. 3 In the gasification zone, the weight ratio of water vapor to heavy oil is 0.
The method for gasifying heavy oil according to claim 1, wherein there are five or more.