SU67610A1 - Method of cracking petroleum and similar raw materials - Google Patents

Description

In order to meet the growing demand for motor gasoline, liquid phase thermal cracking is used under pressure, which allows to increase the gasoline yield to 42% of the weight of the processed oil (direct distillation yields about 10% of gasoline). A significant disadvantage of this method is the low quality of the gasoline produced.

Recently, catalytic cracking has become widespread, for example, according to the Goodry method. The essence of this method is that hydrocarbon vapors heated to 450 ° are passed through a chamber filled with a catalyst, clay or synthetic aluminosilicates. In the process of heterogeneous catalysis, splitting of large hydrocarbon molecules, their aromatization and isomerization occurs.

As a result of the catalytic conversion of heavy oil, high-quality gasoline is obtained, in the amount of 45-50% by weight of the processed oil.

The desire of researchers to improve the technological process of catalytic cracking according to the method of Goodrey led to the development of thermophore and liquid catalytic cracking.

In the case of liquid catalyst, as in thermophore catalytic cracking, unlike the Goodry method, a continuous flow of catalyst is used. But in the case of liquid catalytic cracking, the catalyst is not transferred with the help of mechanical lifts, as it is done in the process of thermophore cracking, but is injected (blown) into the catalytic chamber into the stream of hydrocarbons in the form of a powder.

In the case of "l catalyzed cracking, the most severe contact between the hydrocarbon vapors and the catalyst surface is reached, under such conditions that the catalytic process is achieved.

No. 67610-2 -

may be the fastest and lolno (compared with the method of Goodry and thermophore cracking).

In the catalytic cracking process, there is a significant disadvantage in that when heavy oil is heated, not all of their mass turns into a vaporous state, therefore, not all of their mass can be catalyzed by the catalyst in the vapor phase. For this reason, the yield of gasoline is reduced. This disadvantage is inherent in all variants of catalytic cracking. In addition, in order to achieve the most complete contact between hydrocarbon vapors and the catalyst surface (per unit catalyst weight), the catalyst must be ground (to achieve the highest specific surface area). The crushed catalyst in the form of a powder is difficult to introduce into the catalytic chamber.

If this drawback was overcome in a catalytic cracking process, a significant increase in gasoline yield could be achieved. To do this, it is necessary that heavy oil runners not be evaporated, but sprayed in a catalytic chamber. At the same time, the spray should be as finely dispersed as possible, with particles of the size of droplets of the order of 1 micron and less.

According to the invention, this is achieved by spraying the cracker in the heated reaction chamber, a water-type emulsion chamber, - oil.

When heated by the emulsion, the water enclosed in the oil casing is overheated. This creates ideal conditions for water heating, since there are no centers that promote normal boiling (preventing overheating).

When a certain critical temperature is reached, the water enters the vapor state, instantly expands and with great force breaks the shell - the external phase of the emulsion (oil), breaking it into extremely small droplets.

The explosion of a drop of water-oil emulsion occurs at an ambient temperature of 170-200 ° (and more). The time required to heat the emulsion droplets to the state in which they "explode" depends on two factors: on the initial size of the emulsion droplets (after spraying it with a spray gun) and on the ambient temperature. The smaller the initial droplet size and the higher the ambient temperature, the shorter the time required to achieve the "explosiveness of the emulsion droplets".

When preparing a water-to-oil emulsion that is capable of "exploding (at an appropriate ambient temperature), it is necessary to inject 3-5% of water. A large percentage of water improves the explosiveness of the emulsion.

In the emulsion, you can enter the catalyst. This technique eliminates the difficulty inherent in liquid-catalytic catalytic cracking, since the introduction of a catalyst powder into the catalytic chamber, as a component of an emulsion, is a much simpler task than the introduction of a powder in its pure form.

In the same case, when the catalyst is soluble in water, it is very convenient to introduce it into the catalytic chamber, by dissolving it in that part of the water that goes to the following emulsion:

water solution of catalyst / heavy oil.

Subject invention

Claims (1)

1. A method for cracking petroleum and similar feedstocks, such as heavy oil and coal products, in finely dispersed form, characterized in that the cracking feedstock is sprayed into a heated reaction chamber in the form of a water-oil emulsion. 2, the method of carrying out the method of claim 1, characterized in that a catalyst is introduced into said emulsion. - 3 - # 67610