DE705528C - Process for the production of solid aliphatic hydrocarbons - Google Patents

Description

Process for the production of solid aliphatic hydrocarbons It is known that at temperatures of 3oo to 400 ° and at pressures around 1 oo at with the help of catalysts made from mixtures of carbon monoxide and hydrogen higher Can produce hydrocarbons and oxygen-containing hydrocarbon derivatives. Catalysts for this are cerium, chromium, cobalt, manganese, molybdenum, osmium, palladium, Titanium and zinc or their oxides or other compounds have been proposed. The nature of the hydrocarbons obtained was inter alia. executed that they in the main thing is to boil below 2oo ° or below 250 ° and that you use special cleaning methods can win a product that has a petroleum-like character. It was also known that solid paraffins are obtained when the synthesis is carried out on catalysts of the iron group carried out at temperatures below 300 ° under increased pressure.

It is also known (fuel chemistry 6 t1925}, p.268 to 27i), that on ruthenium contacts at ordinary pressure and at temperatures from 3oo to 400 ° in addition to methane, small amounts (0.2 to 0.6%) of unsaturated hydrocarbons en can be obtained. It is also known (fuel chemistry 16 [193y, p. 466 to 469) that carbon dioxide and carbon dioxide in the presence of ruthenium contact already at temperatures of about 150 °, not only to gaseous, but also can be reduced to liquid and paraffin-like hydrocarbons.

It has now been found that particularly high yields of solid aliphatic hydrocarbons of paraffinic character and also particularly high-melting solid hydrocarbons can be obtained if one is at temperatures below 300 °, for. B. at 2oo °, works with a Rutheniumkontakt while in contrast to the last-called publication, are given in the already low temperatures at elevated pressures, such as 20, 50 ,, ioo at and about work. Working at low temperatures, but at increased pressure, with ruthenium contacts not only allows the production of solid paraffinic hydrocarbons, but also gives particularly good yields and, what is no less important, is associated with a particularly valuable technical effect; This consists in the fact that, in contrast to the behavior of all other catalysts towards carbon oxide-hydrogen mixtures, the ruthenium contact shows an unlimited constant activity under the specified conditions. From month to month, with a constant gas throughput, without an increase in the temperature, let alone a regeneration or even just a resuscitation of the contact, the yields are equally good. With continuous operation of over half a drive, no decrease has been observed so far. Exemplary embodiment To establish the contact, metallic ruthenium is converted into potassium ruthenate by melting with alkali metal and potassium nitrate. This is dissolved in water and methyl alcohol is added at the boiling point. It falls to ruthenium dioxide, which is filtered, washed and dried.

The freshly made contact is first reduced, for example with the synthesis gas (C O: H. = i: 2 @ at atmospheric pressure and a temperature of about 150 °. Then at a temperature of 1g5 ° and a pressure of i oo at 1 1 carbon oxide-hydrogen mixture per gram of ruthenium and hour over the Contact directed. Per cubic meter of gas i 50 to 16o g of hydrocarbons are produced, of which two thirds are made from solid, oil-free paraffin, the remainder from liquid hydrocarbons consists. The service life of the contact is practically unlimited. The total paraffin is snow white and melts clear at 118 to 12o °. By treating with solvent can be extracted from this larger amounts of particularly valuable, up to over i3o '"melting Isolate paraffins. You can of course, the ruthenium contact after the produce a wide variety of methods. What is necessary is that it be used in a form in which he offers the implementations a large surface. It can too various substances (e.g. alkalis) or loosening agents (e.g. kieselguhr) are added to the ruthenium.

The pressures and temperatures can range between relatively wide There are limits. However, pressures that are close to atmospheric pressure are used are and / or temperatures of 300 ° and above, then the reaction proceeds in an undesired direction, namely with the predominant formation of gaseous products. If you work at pressures above 3o at as low a temperature as possible, in which just still satisfactory conversion of the carbon oxide is achieved, z. B. 17o to Zoo ', then you get good yields of particularly valuable, high-melting ones Paraffins that are neither supplied by nature nor produced artificially so far could become.

The gas throughput is limited by the heat dissipation capacity of the reaction apparatus, since the contact is able to handle larger amounts of gas than to implement the mentioned in the example of 11 per gram of ruthenium per hour.

A carbon oxide-hydrogen mixture was used as the synthesis gas in the example chosen in a ratio of 1: 2. However, it can also be richer in hydrogen or richer in carbon oxide Gases are used.

Claims (1)

PATENT CLAIM: Process for the production of solid aliphatic hydrocarbons from hydrogen and oxides of Kohlenstorfäs at temperatures below 300 °, in particular between 150 and 28o ', and at elevated pressure, in particular above 30 at, characterized in that ruthenium contact or ruthenium-containing contacts are used.