US1986238A - Production of valuable hydrocarbons from gaseous hydrocarbons - Google Patents

Description

Patented Jan. 1, 1935 PATEN OFFICE.

- PRODUCTION OF VA LUABLE HYDROCAB- BONS FROM GASEOUS HYDROCARBONS Fritz Winkle'r and Hans Haeuber, Ludwigshai'enon-the-Rhine, Germany,

assisnors to'I. G. Farbenindustrie Aktieng'esellschait, Frankfort-onthe-Main, Germany No Drawing. Application March 16, 1931, Serial No. 523,183. n

Germany March 22, 1930 1 Claim. (01. 260l68) The present invention relates tothe production of valuable hydrocarbons tromgaseous hydrocarbons of the parafllnic and oleflnic series.

We have found that the conversion of normally gaseous saturated or oleflnic hydrocarbons, as for example methane, ethane, ethylene and the like, if desired in admixture with other gases, such as nitrogen or hydrogen, into hydrocarbons of higher molecular weight, especially into liquid hydrocarbons of aliphatic and aromatic nature, by heating the gases to high temperatures between 400 and 1100 C. is eflected with particular advantage, ii. these gaseous hydrocarbons are first laden with-metal vapors at a temperature which lies above the melting point and, if desired, above the boiling point of the metal employed but below the said conversion temperature of the said gases and then heated in the presence of the said metal vapors to the said conversion temperature. Metals which come into question for the present process are in particular those which melt below 500 C., such as mercury, cadmium, lead, tin or zinc.-

The gases may be laden with metal vapors by being passed through molten or boiling metals, by being passed over molten or boiling metals or by injecting into them vapors of metals or gases, for example diluent or indiilerent gases; such as nitrogen or hydrogen, containing said vapors.

The vapors of the metals are usually added to the gasesto be treated or under treatment in small amounts, for example in an amount oi. about up to 2 per cent of the volume of the said gases, but also greateramounts of metal vapors may be added though the eflect obtained is not substantially increased thereby. There exists no under limit of .the amounts oi metal vapors to be employed since even traces as for example 0.01 per cent the said vapors have a remarkably favorable eii'ect on the treated gases.

The mixtures containing the metal vapors may also be led over catalysts. such as those used in Dyrosenic reactions, as (or example over silicon, molybdenum, tungsten, chromium or .carbon in various forms such as graphite. coke and the like. the heat necessary for the reaction being supplied by the catalysts if desired, instead of through the walls, by employing them as electrical resistances. Such catalysts are advantageously employed as do not give rise to a deposition 01' carbon. By working thus with solid catalysts, inter alia, a better utilization of the heat is ensured. The walls of the reaction chamber are preferably constructed of or coated with a material which prevents the deposition or car'- bon, as for example chromium, graphite, tin, tin

alloys, as for example with lead,- and the like. The process according to the present invention may be carriedout at any pressure under which at the temperature employed the vapor pressure 5- oi the metal used is so high that the metal vapor may be present in an amount of 0.01 per cent of the hydrocarbon gases treated. The reaction temperature is generally speaking between 400 and 1100 0., and advantageously above about 500 C. but varies according to the hydrocarbons to be converted and to the other working conditions. At temperatures below from 700 to 750 C. mainly aliphatic hydrocarbons are obtained, whereas above this intervalthe formation of aromatic hydrocarbons predominates. g

In general, the higher the number of carbon atoms in the molecule, or the initial gaseous hydrocarbons, the lower will be the temperature required.

The following examples will further illustrate the nature of this invention, but the invention is not restricted to these examples. The percentages are by-volume unless otherwise. specifled.

- Example 1 separating the mercury behind the reaction chamber, a yellow brown mist forms which when further cooled yields a liquid condensate boiling up to 250 C. and'consisting mainly oi aromatic hydrocarbons. About 10 per cent or more oithe methane is thus converted into liquid hydrocarbons.

The process may be carried out in a cycle by charging the residual gas after separating the reaction products and after lading it with mercury vapor through the reaction chamber again; Several reaction chambers arranged one behind another may also be employed. No formation of carbon black or other deposition of carbon can be detected even after working for long periods of time.

Example 2 liters of ethylene which has been laden with mercury vapor by over boiling mercury as are led per hour' through an internally tinned tube of V2A-steel having an internal diameter of 18 millimeters and a length of about 60 centimeters andheated externally to about 725 C. The reaction product is a condensate which boils above 40 C. 92 per cent of it boils below 180 C. and

it consists mainly of aromatic compounds of lowboiling point. 22.4 per cent by weight of .the

' ethylene employed is converted. or the ethylene used up, 31.4 per cent by weight is converted into propylene, butylene and butadiene (the latter of which is isolated as the tetrabromide) and 42.5 per cent by weight is converted into the said liquid condensate.

Example 3 lene and a little butadiene, 25.5 per cent of ethylene, 21.2 per cent of hydrogen and 48.9 per cent of methane and 5 grams of a condensate boiling above 40 C. having a composition similar to that described in Example 2 of which 70 per cent by weight boils below 200 C.

12.5 per cent by weight of propylene, butylene and a little butadiene, 35.2 per cent by weight of ethylene, 12.5 per cent by weight of liquid hydrocarbons, 3'7.8 per cent by weight of methane and 2.0 per cent by weight of hydrogen are obtained from the gas employed.

What we claim is:--

In the conversion of a normally gaseous hydrocarbon selected from the paraflinic and oleflnic series into liquid hydrocarbons by heat treatment at a temperature, between 400 and 1100 C., sufflcient for. carrying into effect this conversion, the steps of charging the said gaseous hydrocarbon with up to about 2% by volume of mercury vapor at a temperature which lies above the melting point of mercury but below the said conversion temperature, and then heating the said gaseous hydrocarbon to the said conversion temperature.

FRITZ WINKLER. HANS HAEUBER.