DE634330C - Process for the production of low-boiling hydrocarbons - Google Patents

Description

Process for the production of low-boiling hydrocarbons It is known that gaseous hydrocarbons of the methane series or containing hydrocarbons To convert gas mixtures into liquid hydrocarbons that they are at normal or elevated pressure, optionally in the presence of catalysts, heated. In order to achieve the greatest possible conversion of the hydrocarbons, are, especially when working at normal pressure, very high temperatures necessary. At these high temperatures, however, the desired formation occurs of valuable low-boiling hydrocarbons (higher olefins, benzene, toluene) at the same time a more or less extensive splitting and condensation of the formed low-boiling hydrocarbons, so that hydrogen on the one hand and diphenyl, naphthalene, anthracene and carbon on the other hand.

It has now been found that the thermal treatment of Methane hydrocarbons, which may be unsaturated hydrocarbons may contain, with extensive conversion of the first-mentioned hydrocarbons high yields of valuable low-boiling, especially aromatic. Hydrocarbons. obtained if the starting materials are applied at least twice at any pressure various temperatures rising above Soo °, but not heated so high that considerable amounts of polynuclear hydrocarbons are formed and after each heating which separates liquid reaction products at normal temperature. One can for example, work in such a way that the gases are continuously separated the liquid hydrocarbons' treated in a cycle, with the temperature can be increased continuously in the reaction chamber. Is the concentration of the starting hydrocarbons has become too low, then these, z. B: by washing with oil under pressure or by means of active charcoal, enriched and fed back into the process. Man can also work in such a way that the individual heating processes are carried out in different apparatuses performs under changing conditions z. B. the temperature, the catalyst, etc.

It is essential that temperatures of over 500 ° can be used, since, as has been shown, only useful in this case Exploit. of aromatic hydrocarbons.

However, it should be noted that even at high flow velocities temperatures of 130 ° for methane, 100 ° for ethane, 100 ° for propane and in the case of butane, 95o ° must generally not be exceeded. It is @ known; at the extraction of liquid hydrocarbons from gaseous ones the residual gas, which has not yet reacted, a second time the reaction be;,. @ subject to conditions, be it in a second apparatus or by means of work in the:; Cycle. In contrast, in the present method in the successive Treatments used different, namely increasing temperatures. Only in this one Trap is achieved. the high yields given in the following examples low-boiling liquid hydrocarbons.

The process of patent 605 432 for separating methane from other gaseous hydrocarbons, whereby the hydrocarbon mixture to be treated is subjected to a gradually increasing heating and after each stage: separation of the hydrocarbons formed from the other hydrocarbon gases, is not claimed here. If methane-containing hydrocarbon mixtures are used in the present case, not only are the other gaseous hydrocarbons added to the methane converted in order to be separated from the methane, but the methane itself is also partially or largely converted into liquid hydrocarbons Gas mixture of the following composition: 6.16 percent by volume of butylene, 37.84 percent by volume of butane, 4.50 percent by volume of propylene, 39.50 percent by volume of propane, 0.84 percent by volume of ethylene, 11.16 percent by volume of ethane is produced at a flow rate of 141 / hour .. passed one after the other through three 6o cm long, silicon-filled porcelain tubes (clear width 1 & mm). The Pbrzeilane tubes are heated to 800 °, 85o ° and goo ° .. The liquid reaction products formed are removed after each tube by means of active carbon.

A total of 350 g is obtained per cbm of starting gas. liquid condensate (density 0.9), which contains around 60% to 10o ° boiling components (mainly benzene). ' If, on the other hand, the liquid reaction products are deposited only behind the third pipe, 340 g of liquid condensate (density i, o) per cbm of starting gas are obtained, which contains only 35% to 100 ° boiling components (mainly benzene) and mainly consists of Naphthalene is made. Example 2 Methane (27 1 / hour) is circulated through a porcelain tube heated to rynd ii oo ° (10 mm clear width and 3 o cm heated length) that only a small part is circulated with each passage des et'hans is converted into higher molecular weight compounds r (aromatic hydrocarbons, especially benzene, also ethylene and acetylene), whereby the hydrocarbons formed, which are liquid at ordinary temperature, are permanently removed from the circuit by freezing.

Over the course of 25 hours, the temperature of the reaction space is slowly increased to 300 ° in accordance with the increasing elimination of hydrogen. -In the beginning the gas used contained 93 % methane; . After 25 hours the gas had the following composition with a volume increase of 40%: 1, 0% C.H2, 1, 0% C2H4, 79.09o H ", 12.2% CH, and 6.8% N2. The porcelain junction tube was not yet clogged with separating carbon after 125 hours of operation. In the cycle test, 50 g of liquid hydrocarbons containing 60% of benzene are obtained per cbm of 93 % CH4.150 g , 6th percent by volume C, H0 -C4 H8, 4.4 percent by volume C1H4, 0.4 percent by volume H2, 91.4 percent by volume C ", H2n + 2 (n = 2.7) (propane with about 10/0 ethane) , 2.2 volume percent N2 in the circuit with a flow rate of 3o1 / hour. through a porcelain tube heated to 85o ° (clear width 10 mm, length 400 mm), whereby only a small part of the gas is converted into benzene and the formation of polynuclear condensation products and deposition carbon is largely avoided; the liquid products formed are removed from the circuit by freezing after each pass.

The temperature of the reaction space becomes uniform within 136 hours increased to 950 °. Gas with the above composition 410 is obtained from i411 1 gas from. the following composition: 4.0% C2 H4, 43.6% Hv 51.6% C H4, oß% N2 and also go g liquid condensate with go 0/0 to 2oo ° boiling, mostly components consisting of benzene. The porcelain tube is after 136 hours of operation almost free of deposition carbon.

Claims (1)

PATENT CLAIMS:. i. Process for the production of low-boiling, especially aromatic hydrocarbons from gaseous hydrocarbons the methane series; which may still contain unsaturated hydrocarbons, at elevated temperature and any pressure, characterized that the starting materials at least twice to different increasing temperatures over 500 °, but not heated so high that significant amounts of polynuclear hydrocarbons and - after each heating, the reaction products that are liquid at normal temperature, removed, excluding the method of patent 6o5432. -2. procedure according to claim r, characterized in that the starting materials according to one or several heatings are concentrated and treated anew.