DE1217363B - Process for the production of acetylene and ethylene - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

C07c

German class: 12 o-19/01

Number: 1217 363

File number: M 47529IV b / 12 ο

Filing date: December 27, 1960

Opening day: May 26, 1966

There are numerous methods of making acetylene and olefins by the pyrolysis of hydrocarbons in a gas stream at high temperatures, but these methods have been used to this day carried out under a pressure very close to atmospheric pressure, since it was believed that the equilibrium the reaction by which acetylene is formed is shifted by increasing pressure.

In contrast, it has now been found that the yields of acetylene and olefins are essentially equal to the yields achieved under atmospheric pressure, even when the pressure is increased up to 10 at and above can be obtained if the pyrolysis of the hydrocarbons is under appropriate conditions Conditions is carried out.

Since the gases formed by the reaction for the separation of acetylene and ethylene after Reaction must be compressed, the pyrolysis of hydrocarbons under pressure allows one very noticeable savings both in terms of the cost of the installation and in terms of energy consumption compared to the pyrolysis process carried out at atmospheric pressure.

According to the new invention, a particular advance is achieved in that the water cooling of the gases leaving the furnace allows the recovery of a considerable amount of heat at a temperature of more than 150 ^° C. Saving of steam is achieved.

It has been found to achieve satisfactory acetylene and ethylene yields necessary according to the invention by pyrolysis of a paraffinic light gasoline at a pressure of 10 atm is that the flow rate is higher than 800 kg / h / l of the reaction chamber volume.

If the pyrolysis pressure is increased or decreased, it is necessary to adjust the hourly flow rate to increase or decrease the light gasoline accordingly.

This is an extraordinary advantage of the method according to the invention, since you can pyrolysis ovens with a Can provide production capacity of some 10 t / day of acetylene and olefins if the pressure is on can be increased in an appropriate manner. The light petrol should be added to the the highest possible temperature due to its heat stability. It is for this one Purpose expediently to steam the evaporated light gasoline before introducing it into the superheater Mix.

Process for the production of acetylene and
Ethylene

Applicant:

MONTECATINI, Societä Generale per
rindustria Mineraria e Chimica,
Milan (Italy)

ίο representative:

Dipl.-Ing. Dipl.-Chem. Dr. phil. Dr. techn.
J. Reitstötter and Dr.-Ing. W. Bunte,
Patent Attorneys, Munich 15, Haydnstr. 5

Named as inventor:

Giacomo Fauser, Novara (Italy)

Claimed priority:

Italy of December 31, 1959 (21733)

The high-temperature gas stream with which the pyrolysis of the light gasoline is carried out is by burning part of the in the same plant after separation of acetylene and ethylene obtained residual gas in the presence of oxygen. To achieve a high thermal yield, a complete combustion of the hydrocarbon must be achieved, with the gas-to-oxygen ratio very close to the stoichiometric value is used, while at the same time to be too high To avoid temperatures, a significant amount of steam will be introduced into the combustion chamber got to.

The vapor is easily separated by condensation from the gases leaving the furnace, so that

it does not hinder the process steps required to separate the acetylene and ethylene. Nevertheless, this increases the cost of the products noticeably.
According to the invention, an efficient method for producing the steam required for the gases is now provided, in which the heat present in the reaction products is used.

The method is characterized in that the water vapor to the fuel and the Combustion certain oxygen through saturation with water, which through heat exchange with the hot reaction products was superheated, fed

609 570/566

3 4

and the pyrolysis at pressures of more than 3 at, fore-exchanger 13 fed back with the aid of the pump 18.

preferably carried out between 10 and 20 at. To pay for the water consumption, leads

It is advantageous to use the steam to be pyrolyzed together with that from the other heat hydrocarbon add before it overheats. hot water that flows back using part of the use, fresh the drawing shows the operation of the system 5 water in the circuit between pump 18 and cut-out shown. exchanger 13 to. By means of the compressor 2 one leads

The furnace consists essentially of a cylinder 1900 Nm ³ combustible gas at 15 at pressure in the

vertical stainless steel chamber 6, humidification column 4. The gas has a calorific value

which is cooled by a water jacket, from over 16 900 kcal / Nm ³ and has the following additions

which evaporates water due to the heat of reaction. io composition on: It is favorable to have the vapor pressure relatively high

to keep in order to avoid excessive heat losses in the H2 0> 89 ° / ₀

to avoid combustion chamber; in any case should _N2 0.47 ° / ₀

the vapor pressure must be higher than the pressure at which CO 20.41 ^Q / _o

the hydrocarbon is injected into the furnace. 15 qtt ο ^ a ο /

Oxygen and fuel gas from the compressors 1 ⁴ ' ₀ , "

and 2 are in the saturation ^{columns 3 and 4 ^ 2} ° 'y6' °

and when preheated at 5 they reach the C ₃ 46.19 ° / o

Combustion chamber 6. C ₄ 15.74 ° / ₀

The fuel gas can partly be supplied by a corresponding amount of light gasoline from the pump 19

be replaced. The light gasoline, which the pyrolysis at the top of the column 4 is given with the help of

is to be subjected, is taken by the nozzles 7 and 9 pump 15 from the bottom of the cracking furnace

injected into the oven. Hot water at 160 ° C. The gas comes out of the

In the reaction zone 8, due to the high column 4, saturated with 100 kg of steam predominates; it will

Temperature, the formation of acetylene, while in the in 5 is preheated to 600 ° C and then the combustion

Zone 10, in which the temperature drops to 800 ° C, is fed to chamber 6. The pump 19 is used to send

the formation of olefins predominates. 19,000 kg of gasoline to preheater 5; after the pump

Finally, the reaction products are injected with 4100 kg of water vapor; the fumes from

Water injected through the nozzles 11, gasoline and water are preheated in 5 to 600 ° C

deterred. and then at about 12 at pressure through 7 and 9

The hot water that collects at the bottom is fed into the pyrolysis chamber. The pyrolysis

injected via the pump 15 into the column 4, is carried out at around there in the tenth The pyrolysis gas is at 165 ⁰ C

to saturate the fuel gas with moisture. The use of hot water injection (60,000 kg hot

The ratio of steam to gas can be easily cooled by changing 35 water) by 11. At the bottom of the reactor

Adjusted to the flow rate of the water, some of the injected water collects

will. the column 4 is fed. - The one with water

The gases that leave the furnace initially flow; steam-saturated pyrolysis gas leaves the reactor

through the heat exchanger 13, in which the at 165 ° C and at 10 at. It has exclusively des

humidification of the oxygen in column 3 and for 40 water vapor a volume of 28 500 Nm ³ and

The following composition is required to cover the heating requirements of the system: Water is preheated. Then they will be in

Cooler 16 cooled, in which at the same time as the steam H ₂ 25.89%

the heavier fractions of the carbon formed- N ₂ ^ 53 0 /

Hydrogen to be condensed; these are in the 45 qq 2AAA ⁰ I.

Brought separation vessel 17 and used as fuel; ' _0. °

finally the gases exiting at 14 become ^ O ₂ "'°

Acetylene and ethylene worked up. CH ₄ 9.33%

The process can be modified to a large extent: C ₂ H ₄ 18.14 ° / ₀

and the ratio of acetylene to ethylene permits 50 qjj g _; 420;

within a wide range depending on the q π η'βΐ ο /

seen industrial recovery. * ^β '. °

Cn 6.01 / o

Example WÖßÖ%

The indicated amounts are hourly delivery. The gas is in the exchanger 13 to approx

amounts. 100 ° C and in exchanger 16 to room temperature

8300 Nm ^{3 of} oxygen are cooled with HiKe des Korn-. That the acetylene and the ethylene

pressors 1 at a pressure of 13.2 ata in the retaining gas exits through 14, whereupon it separates

humidification column 3 led; from this column 60 is worked up.

the oxygen emerges saturated with 3900 kg of steam. According to the example a total of 9000 kg steam are Saturation is carried out at 16O ⁰ C with the aid of 40 m ³ introduced into the reactor. Of these 9000 kg, stam water that comes from the exchanger 13 and more than half, ie 4900 kg, is fed in from the head of the column 3. The moist, acidic dampening of the reaction participants. This means that material is preheated to 600 ° C. in exchanger 5, 65 a very considerable advantage in view of the fact before it enters combustion chamber 6. From the thing, characterized in that said proportion of 4900 kg of steam enters the bottom of the column 3 verbhebene water at in a very economical way without the cost of a temperature of 100 ⁰ C and is of the reactants is obtained in the initial moistening.

It should be noted that otherwise this proportion of steam would have to be supplied from the outside at considerable costs.

Claims (2)

Patent claims: 1. Process for the production of acetylene and ethylene by thermal cracking of hydrocarbons in a stream of hot combustion gases and in the presence of water vapor, characterized in that the water vapor to the fuel and the oxygen intended for combustion through saturation with water, which overheats by exchanging heat with the hot reaction products was fed, and the pyrolysis at pressures of more than 3 at, preferably between 10 and 20 at, is carried out. " 2. The method according to claim 1, characterized in that the steam is to be pyrolyzed Hydrocarbon is added before it is overheated. Considered publications:
U.S. Patent Nos. 2,176,962, 2,394,849;
Austrian Patent No. 202 122;
Petroleum Refiner, 38 (1959), No. 11, p. 206;
A si η ger, Chemistry and Technology of Monoolefins, Berlin, 1959, p. 117. 1 sheet of drawings 609 570/566 5.66 © Bundesdruckerei Berlin