JPS59501068A - Method for thermal decomposition of hydrocarbon oil - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Method for thermal decomposition of hydrocarbon oil This invention is a method for thermally decomposing hydrocarbon oil, in which hydrocarbons are heated at a reaction temperature of 1. , then introduced into the reaction zone, where the flow is from bottom to top. Concerning a decomposition method consisting of:

In pyrolysis of hydrocarbon oil, heavy oil fraction is cracked into light oil fraction. Gain rate increases. During decomposition, the raw material is heated in a heating tube in the decomposition furnace using a decomposition temperature switch. be done. Generally, there are two styles of methods. One of them is that decomposition is caused by heating inside the decomposition furnace. In this case, some decomposition reactions occur in the next process following the decomposition process. It also occurs in the conduits connecting to the pipe. This type of decomposition method uses the girade time (dela y time) is not precisely elucidated, but it is relatively short and one common tax It is.

The pressure fluctuates significantly and drops from the furnace inlet to the outlet.

Other types of cracking processes involve processing raw hydrocarbon feedstocks in a cracking furnace at a suitable reaction temperature. The process is heated and a separate reaction zone is set up where the actual decomposition reaction occurs. The actual girade time is extremely long compared to the above method, about 10 to 30 minutes. . No heat is introduced into the reaction zone.

In the latter method, the reaction zone usually consists of an upright cylindrical pressure vessel separated from one end. Raw materials heated in the cracking furnace are fed into the furnace, and a gas-liquid mixture is extracted from the other end. It is sent to the next purification step, such as a distillation step. Is the direction of flow in the reaction zone upward? Either from the top down or from the bottom up.

In the thermal decomposition of hydrocarbon oils, essentially two types of reactions occur. One of them is decomposition It is a reaction itself, in which long-chain molecules are split into shorter-chain molecules, accompanied by a decrease in viscosity. cormorant. The other reaction is called a polycondensation reaction, in which each molecule joins together. Pitch and coke are generated while releasing hydrogen. The latter reaction is asphalt This is not preferable because it increases the tensile content. The higher the temperature, the more this polycondensation becomes dominant. Therefore, the temperature should be lowered as much as possible and the girade time should be increased accordingly. The work is being done.

Girade time is extremely important in pyrolysis. This dilation time is also short. If the dilation time is too long, the decomposition products will react with each other. , resulting in undesirable products. This is because the resulting component is unstable. Oil containing this is difficult to use as a fuel. Therefore, the decomposition is as uniform as possible. It becomes the supreme command to arise. The flow in the pressure tank as a reaction zone is non-uniform. If so, the girade time will fluctuate.

In the decomposition reaction, the light components produced are decomposed under the temperature and pressure conditions in the reaction zone. Evaporate. So as the mixture flows upwards in the pressure tank, the density of the gas-liquid mixture decreases. Decrease. Due to the static pressure difference inside the pressure vessel, the density of the gas phase also increases. decreases as it flows upward. The liquid fraction produced by the decomposition reaction is used as a raw material. This is also a factor in reducing the density of the gas-liquid mixture, since it has a low density. So Therefore, the flow rate is constant even though the diameter of the commonly used cylindrical reactor is uniform. Rather, the mixture is accelerated as it moves upwards.

In the pyrolysis method disclosed in U.S. Pat. No. 4,247,387, the reaction zone is A cylindrical upright pressure vessel is used, and a porous pressure vessel is used to prevent reflux within the reactor. An intermediate bottom is provided to form a series of mixing sites in the vessel.

The objective is to achieve as uniform a girade time as possible for the fraction fed into the zone. It's about giving yourself some time. Disadvantages also arise from the provision of such an intermediate plate. Make a mistake If this happens, the entire reactor may be filled with coke, but if such an intermediate bottom is not provided, If this happens, removing coke and cleaning the reactor becomes inconvenient and increases costs.

The purpose of this invention is to improve the conventionally known method, in particular to prevent cleaning To provide a method by which a uniform girade time can be achieved without providing an intermediate bottom such as It is in.

The purpose of this invention is to cause a gas-liquid mixture to undergo tangential rotational motion in a pressure vessel constituting a reaction zone. This is achieved by a method whose main feature is to do as follows.

The invention is described in other claims 2 to 6.

In the method of this invention, the reaction zone rotates tangentially but vertically uniformly upward. A progressive gas-liquid flow occurs, which causes non-uniform girade times. No reflux occurs. A flow in which a gas-liquid mixture rotates in the tangential direction can be obtained by various methods. can be done. According to one advantageous embodiment, a pressure vessel constituting the reactor is provided with a Rotational motion is created by arranging a spiral member that forms a spiral-shaped ascending corridor. You can In this type of passage, the flow is always upward and downward. doesn't happen. This helical system may be provided over the entire length of the reaction zone, or may be partially It may be placed in In some cases, this helical member is placed only in the artificial part of the reaction zone. Satisfactory results can be obtained even with this arrangement.

In addition, two or more spiral members are arranged in the reactor to control the rotation of the gas-liquid mixture. The direction can also be reversed. In this case, the gas-liquid mixture flowing through the reaction zone One or several mixing steps take place.

Other embodiments of the reservoir for rotating the gas-liquid mixture in the tangential direction include There is a method using a nozzle. Raw materials or other liquids such as steam may pass through this nozzle. A favorable rotational motion can be imparted to the raw material by passing through the material. Noz The number of nozzles is selected as required, and is, for example, 2 to 20 nozzles. People in that range At the mouth, the hydrocarbon feedstock to be cracked is fed tangentially into the reaction zone. Alternatively, a raw material supply pipe may be installed.

According to a further advantageous embodiment, the reaction zone extends upwardly over its entire length. or, for example, only the supply section is partially enlarged upwards. You can also do that. Such a conical shape evens out the distribution of sillage by itself. It has the effect of

From the decomposition reaction point of view, the preferred temperature is 410-470°C and the pressure is 2 bar. It is known that the range is between 1 and 20 bars. Ratio of average diameter and length of reaction zone is in the range of 1 to 1:20.

Some advantageous embodiments of the invention will now be described in detail with reference to the accompanying drawings. However, the present invention is not limited to this.

FIG. 1 is a schematic representation of one advantageous embodiment of the method of the invention.

FIG. 2 is a schematic elevational view of an advantageous embodiment of the reactor used in the invention.

FIG. 3A shows, from above, another advantageous embodiment of the reactor for use in the process of the invention. This is a diagram.

FIG. 3B is an elevational view of the reactor of FIG. 3A.

Figure 4A shows another advantageous embodiment of the reactor for use in the invention, seen from above the reactor. vinegar.

FIG. 4B is an elevational view of the reactor of FIG. 4A.

Example I In FIG. 1, the feedstock is introduced into a furnace 12 through a tube 1, where it is brought to a temperature of 41 Heated between 0 and 470°C.

From the furnace 12, the feedstock oil is introduced into the reactor 14 via a pipe 13, where it flows upward. The tube 15 is then extracted from the top of the reactor and sent to a separate unit (not shown). Sent. This unit is compatible with gas, vetol, light fuel oil and heavy fuel oil. separated from each other. The average girade time in the reaction zone is between 5 and 100 minutes. .

In the embodiment of FIG. 2, a conical member 16 is formed within the reactor 14. In the embodiment of FIG. Disassembly The hydrocarbons to be treated are introduced into the reactor 14 from below upwards, where the helical section It enters the spiral corridor consisting of the control G, where the actual decomposition occurs.

In the embodiment of FIG. 2, reaction zone 18 includes two spirals with opposite helical directions. The helical members 16 and ]7 are equally arranged. This allows the inside of the reaction zone 18 to The flowing gas-liquid mixture reverses its direction of rotation.

3A and 3B show the lower part of the pressure vessel 14 constituting the reaction zone 18, where In this case, the flow of hydrocarbons to be cracked is directed from below to above. Pressure tank 14 A nozzle j9 is connected in the tangential direction at the bottom of the The body imparts a rotational motion to the stream of hydrocarbons introduced through the nozzle to be decomposed. I can do it.

In FIGS. 4A and 4B, a nozzle 21 is formed at the end of the raw material supply pipe 20. This nozzle forces the material into a rotational motion.

Thermal cracking of crude oil was carried out on a pilot plant scale using the equipment shown in Figure 1. It was. A similar device with a reactor without a spiral system was used for comparative experiments. Ta. Other conditions were the same. The raw material oil was vacuum distilled base oil of non-produced crude oil. . The comparison results are shown in the table below.

table Physical property items Feet Properties of base oil product (distillate 180℃+) No spiral system, spiral system available Density (g/sieve 20°C) 1.0011 1.001 1.002 Asphalte (weight) 6.28 10.70 11.10 Sulfur (weight) 3,65 3,38 3.54 Viscosity "cSt (50℃) 43000 42000 330 0 stability (1) -2,02,1 □ (Details regarding 1+ stability are described in the following document: Van Kerkvo ort, W, J, , Nieuwstad, A, J, J, IV: ECon gress Int-ern, du Chauffage Industrj, el, paper number 220. Paris.

'1952 international search report

Claims (1)

[Claims] 1. The hydrocarbon oil is heated in a reaction temperature chamber and then introduced into the reaction zone. A method of thermal decomposition of hydrocarbons in which the flow is from the bottom to the top; The mixture rotates tangentially in the pressure vessel (14) constituting the reaction zone (18). A method characterized in that exercise is given. 2 the gas-liquid mixture is transported by means of at least one helical member (16, 17); 2. A method as claimed in claim 1, characterized in that the rotational movement is imparted by means of a rotational motion. 3 The helical system (16, 17) of the reaction zone (18) spans the entire length of the pressure vessel (14) 3. A method according to claim 2, characterized in that the method is arranged as follows. 4 The helical system (16, 17) of the reaction zone (18) is one of the length of the pressure vessel (14) or simply located in the population part and/or the exit part. A method according to claim 2, characterized in that: 5 The helical system (16, 17) is composed of two or more helical systems Claim 1, characterized in that the scale reverses the direction of rotation of the gas-liquid mixture. , the method according to any one of paragraphs 2, 3, and 4. 6. Said gas-liquid mixture is given a rotational movement by means of nozzles (19, 21) A method according to claim 1, characterized in that: 7 The nozzle (19) is connected to the artificial part of the reaction zone (18) in the tangential direction 7. A method according to claim 6, characterized in that: 8 The nozzle (21) is placed in the reaction zone on the extension line of the hydrocarbon supply pipe (20). 8. A method according to claim 6 or 7, characterized in that the method is arranged in a. 9. The gas-liquid mixture is given a rotational movement by means of the nozzle system (19), and the nozzle Feedstock oil or steam or other liquid is introduced into the pressure vessel (14) through the nozzle. Any one of claims 6, 7 and 8, characterized in that: The method described in. 10 Pyrolysis at temperature 410-470℃, pressure 2-20 bar, average girade time is carried out in the reaction zone (18) under conditions of 5 and 100 minutes. Claims 1, 2, 3, 4, 5, 6, 7, and 8 The method according to any one of paragraphs 1 and 9. 11 Using an upwardly expanding conical pressure vessel (14) as the reaction zone (18) Items 1, 2, 3, 4, 5, 6, and 7, characterized in that: , the method according to any one of paragraphs 8, 9 and 10.