DE2151816A1 - Process for the simultaneous production of carbon oxide and inert gas from hydrocarbons - Google Patents

Description

Jp.-S-r- -t

Dip? - ".. ■ · ■" ⁽ "' ^T

Dr.:. ■ - Jr.

8Mttnc! Ion ^, Usi.icJorfetr. 10 0 1 K 1 Q 1

500-17.668p 18. ίο. 1971

AZOTE et PROBUITS CHIMIQUES S.A., Toulouse

(France)

ONIA-GEGI, Montrouge (France)

Process for the simultaneous production of carbon oxide and inert gas from hydrocarbons

The invention relates to a method and an apparatus for the simultaneous production of carbon dioxide and Inert gas from liquid or gaseous hydrocarbons, especially from the fractions resulting from the distillation of petroleum with a boiling point below 250 C and the liquefiable gases of petroleum result,

For the chemical process that the use of

500- (19Ö All) -Tp-r (6)

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If carbon oxide and inert gas are required, the carbon oxide and the inert gas are usually produced separately.

The reaction of coke with oxygen has long been used to produce carbon oxide, but this process has been used the disadvantage of starting from a solid fuel which is inconvenient to handle and handle. That's why you have in many cases the coke is produced by hydrocarbons

^ sets that one with oxygen and / or air and / or water vapor and / or allows carbon dioxide to react to obtain a gaseous mixture consisting of carbon dioxide, carbon dioxide, Hydrogen and small amounts of methane. This mixture is then treated to separate it into three Main fractions of carbon dioxide, carbon dioxide, which optionally is recycled, and hydrogen ,, One such process can be used economically if the production using carbon oxide is combined with another production can be coupled in which hydrogen must be used. If on the contrary the hydrogen produced is not used in an associated facility and cannot be used as combustible material, the

ψ Cost price of carbon dioxide too high »

In order to generate the inert gas, one of the following two processes is generally used: separation of the atmospheric Air or combustion of a hydrocarbon. The first method results in a good quality inert gas, which consists almost exclusively of nitrogen, but has a high cost price «In the second case, is in order to obtain an inert gas of sufficient purity, the treatment of the fumes is complicated and expensive, and the

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The cost price of the inert gas remains considerable.

The invention is based on the object of showing a solution to this problem if carbon oxide and inert gas are to be generated and the hydrogen is not needed. Simultaneously with the method according to the invention should a device is made possible that is simpler and more compact and reduces the cost price of the desired gases, by improving the energy balance on the one hand and reducing material investment costs on the other.

This object is achieved according to the invention in that the hydrocarbons are partially oxidized with air in the presence of a catalyst, the gas thus obtained in three Fractions, namely the desired carbon oxide, carbon dioxide, which is preferably returned to the previous process step and a residual gas consisting essentially of hydrogen and nitrogen divides and the combustion of the residual gas in order to obtain the inert gas

Passing the partial oxidation with air in a known manner in the presence of a nickel-based catalyst on any support, such as "B ₀ aluminum oxide and / or magnesium oxide, etc Silikoaluminaten-. by »You can use air alone or air enriched with oxygen or add water vapor and / or carbon dioxide. One arteitet such that the-obtained gas contains the highest possible proportion of carbon monoxide, that is, at a temperature of 750-950 ⁰ C, preferably at 800 to 85O ⁰ C and at a pressure ranging from atmospheric pressure to about 40 bar

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and in particular between 15 and 30 bar. When working in the presence of steam, an amount of steam is introduced in the partial oxidation step such that the molar ratio HpO / C of the hydrocarbon being processed is between 0.5 and 2, preferably 0.7 to 1 when the ratio of steam / carbon is set high in the so-defined limits, it is advantageous at a relatively high temperature, for example, _o ^ z to work 850-950 ° C "

Under the above conditions the gas obtained contains at least 15 $ carbon dioxide, carbon dioxide, hydrogen, nitrogen and a small amount, generally less than 2 $ methane. This gas is separated by any suitable method into three fractions on "One can have a physical method such ₀ B ₀ apply the separation of cold, but it generally applies one of two currently accepted in the industry chemical processes" So you separate the Example first the carbon dioxide fraction by washing the gas in an alkaline solution, such as. B. potassium carbonate solution and / or ethanolamine solution. ψ The gas, which has practically been freed from carbon dioxide, is then washed with a solution of ammoniacal copper formate or acetate, which absorbs the carbon dioxide, and a residual gas is obtained that consists essentially of hydrogen and nitrogen with a very small amount of carbon dioxide, carbon dioxide and methane «

The carbon dioxide resulting from the regeneration of the alkaline solution preferably becomes all that Process step of the partial oxidation of the carbon

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Hydrogen recirculated, and that by desorption of the Carbon dioxide obtained from copper salt solution is derived for use.

The residual gas is burned with air to produce an inert gas consisting essentially of nitrogen. The combustion can be carried out in a single step or the primary combustion can be carried out in a secondary one Complete combustion in the presence of a known nickel platinum catalyst. This secondary combustion can vary practically neutral or very slightly reducing or very slightly depending on the desired composition of the inert gas carried out oxidizing. So one takes z. B. when the presence of very small amounts of carbon dioxide in the being produced Inert gas is undesirable, the catalytic combustion of the fumes originating from the primary combustion, in the presence of uncombusted residual gas containing hydrogen. If on the contrary a minor one Methane content of the inert gas should be disturbing, one can quit smoking to oxidize the existing methane add the necessary amount of air.

It should be noted that, without the field of To leave the invention, heat exchangers and / or energy exchangers in the process described above Relaxation of fluids as they are, for. B. are currently used in the treatment of gases, can switch on. as well If this process proves necessary, one can, through condensation, that of the partial step Oxidation-derived gas contained and / or the water contained in one of the three separate fractions split off.

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The drawing illustrates schematically an embodiment of the device according to the invention, with the the method according to the invention can be carried out »

The partial oxidation of the hydrocarbon C H

For this oxidation step, air is fed in at 1, which is compressed by the compressor 11, at 2 the hydrocarbon CH, at 3 water vapor and at 4 recycled carbon dioxide, which W is compressed by the compressor 12. The gas coming from the partial oxidation at 5 is passed to 15, where the separation of the carbon dioxide is carried out, from where it is passed through line 6 to 16 to the process step of separating the carbon dioxide. This latter is withdrawn at 7, while the residual gas , which emerges from there through the line 8, is burned at 17, where compressed air is also introduced through the line 9 by means of the compressor 13. The nitrogen obtained is withdrawn at 10 to be put to use.

k The following is an exemplary embodiment of the method according to the invention, which does not limit the invention, for the generation of 1000 Nm / h (calculated for 0 ° C. and 76Ο mm of mercury) of carbon oxide.

The hydrocarbon to be treated is a crude oil (naphta), which consists of a distillation portion of crude petroleum between about 50 and about 15ΟC. The step of partial oxidation at lh is carried out in a me- '-metallic chamber, the inside is coated with a feu erfesten lining, a catalyst

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Contains nickel-based on a silicoaluminate carrier and provided with a known cooling and heat exchange system is. The oxidation reaction takes place at a pressure of about 20 bar, the temperature being kept close to 800.degree.

The gas resulting from the oxidation is treated at 15 to separate off the carbon dioxide a conventional device, the two towers, namely a washing tower, in which CO 2 is absorbed in a potassium carbonate solution and a desorption tower in which the solution is regenerated with the release of 00_. That Gas coming out of the scrubbing tower is used for separation at 16 Treated by CO One also works in a known system with two towers in which one ammoniacal copper acetate solution circulates that initially Absorbs carbon oxide and then releases it. The residual gas practically freed from CO becomes a combustion device 17, which has a combustion chamber, where the greater part of the combustion takes place, and a final combustion chamber has, which contains a nickel-platinum catalyst and in which the combustion without the need for excess air completely accomplished

3 700 kg of crude oil are fed per hour at 2.2500 Nm

Air at 1 and at 3 such an amount of water vapor, that the water vapor / carbon molar ratio of the hydrocarbon 0.7 is. On the other hand, all of the carbon dioxide gas separated at 15 is returned.

At the outlet 5 of the partial oxidation, the dry gas has the following composition;

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17 $> CO, 20 <yes CO, 20 # H ₉ , 42 # N and 1% CH. “The amount of inert gas available at 10 is 4θΟΟ Nm / ho. This gas contains 99» 5 $ N ₀ and A ₀ .

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Claims (3)

Claims 1. Process for the simultaneous production of carbon monoxide and inert gas from liquid or gaseous hydrocarbons, characterized in that the hydrocarbons are in the presence of a catalyst partially oxidized with air, the gas thus obtained in three fractions, namely the desired carbon oxide, Carbon dioxide, which is preferably recycled to the previous process step, and essentially one dividing residual gas consisting of hydrogen and nitrogen and burning the residual gas for the purpose of preservation of the inert gas = 2. The method according to claim 1, characterized in that the partial oxidation is carried out at a temperature between 750 and 950 ⁰ C, preferably 800 to 85Ο C at a pressure between atmospheric pressure and 40 bar, preferably 15 to 30 bar in the presence of such an amount of water vapor that the steam / carbon ratio of the hydrocarbon is between 0.5 and 2, preferably 0.7 and 1 3. Apparatus for performing the method according to claim 1 or 2, characterized in that it is essentially a chamber (i4) for the partial oxidation, in which the hydrocarbon, air and / or water vapor and / or carbon dioxide are to be introduced, a system (15) with - a washing tower and a desorp- 209817/1358 tion tower for the separation of the carbon dioxide, a second one Plant (16) with a washing tower and a desorption tower for separating off the carbon dioxide and a combustion chamber (17), into which the residual gas and air are to be introduced to convert the residual gas into inert gas. 209817/1358