DE914850C - Process for the production of hydrocarbons from carbon monoxide and hydrogen - Google Patents

Description

Process for the production of hydrocarbons from carbon monoxide and Hydrogen addition to patent 763 307 The invention relates to a development of the Process for the synthesis of hydrocarbons from carbon monoxide and hydrogen under Use of catalysts made from wrought iron or mild steel Patent 763,307. The manufacturing process for catalysts described here Solutions of technical iron, iron salts or iron minerals by precipitation of the Hydroxides or carbonates have certain disadvantages insofar as considerable amounts of precipitants and washing water as well as special agents for drying the precipitate must be spent. The invention enables simplification and cheaper of the process, as these disadvantages are avoided. This is achieved by that the catalyst according to the invention from a solution of wrought iron or Mild steel in nitric acid by evaporation and thermal decomposition of the nitrates without prior removal of dissolved impurities is established, whereby the Iron nitrate, if appropriate, not more than 0.5%, based on the amount of iron Has received additives. Instead of metallic iron, another Feature of the invention such iron nitrates are used, which by dissolving wrought iron, Mild steel or iron minerals obtained in nitric acid and then without purification be subjected to thermal decomposition. The procedure here is such that the nitrates in the shortest possible heating time until the evolution of nitrogen oxide ceases to be roasted. Iron catalysts made in this way have a larger one Volume, d. H. a larger surface than precipitation catalysts.

This way of working, which is distinguished by its simplicity and cheapness offers significant technical and economic advantages not only through savings of precipitants, wash water and an extensive amount for such a treatment Plant, but mainly through the recovery of the decomposition free nitric oxide produced in the form of nitric acid, which in turn dissolves the iron is introduced into the manufacturing process. In the production of precipitation catalysts the nitric acid is lost from the iron nitrate solutions in the form of its salts or in more worthless compounds, which only with greater effort from the precipitation nitrates can be recovered.

However, iron catalysts are already available for hydrocarbon synthesis made from carbon monoxide and hydrogen by decomposing the chemically pure nitrates. Since it is made from chemically pure iron nitrate due to thermal decomposition, however, only almost completely Ineffective catalysts were not expected to be obtained from perfect unpurified solutions of technical iron or iron salts and iron minerals without or with no more than 0.5% additions merely by decomposition extremely effective iron catalysts can be produced from nitrates. At a further known iron catalyst obtained by thermal decomposition of the nitrates are in addition to a content of 25% copper carrier masses @ @udem int the effectiveness this catalyst low.

Examples I. Technical wrought iron is dissolved in dilute nitric acid dissolved and the solution of ferric nitrate, optionally with the addition of 0.2 ° 1O Potassium nitrate, evaporated in vacuo to syrup consistency.

This solution is in small pieces in an iron bowl until finished roasted by the development of nitrogen oxide.

2. A ferric nitrate solution made from the mineral needle iron ore (a-FeOOH), which among other things also compounds of elements from the I. group of the periodic System, for example about 0.1 01o Cu, based on the iron content, was after addition of 0.25 ° lo 0 / <> K2 C 0, and extensive evaporation of the Solution on a highly heated rotating iron drum in continuous operation decomposes so quickly that the evolution of nitrogen oxide ends after a few seconds was. The catalytic behavior is shown in the following table of figures.

3. Unpurified ferric nitrate, which, among other things, also compounds of the elements of Group I of the Periodic Table, for example 0.08% copper was used in the same manner as in Example 1 until the evolution of nitrogen oxide ceased decomposed. The catalytic behavior is shown in the table below.

4. Technical crystallized ferric nitrate was added after adding 0.25% K2CO3 in the molten state in the same way as in Example 1 up to Cessation of nitrogen oxide development, rapidly decomposed.

The catalytic behavior is shown in the following table of figures.

5. Ferrinitrate pro analysi (Mer ck) was after the addition of 0.25.010 K2C 0, in the molten state in the same manner as in Example I until completion rapidly decomposed by the development of nitrogen oxide. The catalytic behavior is as follows Number board reproduced.

Effectiveness comparisons For example 1, synthesis at atmospheric pressure with a mixed gas containing 30% CO and 59% H2 Catalyst catalyst according to the invention from pure iron nitrate Synthesis temperature ° C ......................... 230 235 Volume contraction after 17 hours ............ 16.2% 8.5% - - 48 - ............ 25% 10.6% - - 76 - ............ 31% 11.2% yield a) grams of liquid reaction products per normal cubic meters of synthesis gas,, 110 23 b) grams of gaseous, easily condensable carbon hydrogen per normal cubic meter ........... 35 9 Lifespan ................................ 14 months 2 months Space velocity ........................ 160 90 For Examples 2 to 5, synthesis at atmospheric pressure with a synthesis gas containing 29.5 <> 1 <> C CO and 58.5 <> 1 <>% H2 H2 Yield of liquid and gaseous, Temperature operating gas contract easily condensable reaction Example catalyst off hours of products ° C grams per normal cubic meter of CO + H2 2 needle iron ore ........... 235 250 30 75 3 unpurified nitrate .... 235 250 29.5 73 4 crystal Nitrate ........... 237 250 11 25 5 pa nitrate ............ 237 250 6.5 12.5 Synthesis under increased pressure (I5 atü) with a gas containing 55.5 <> 1 <> CO CO and 35.5 ° / 0 H2 Yield of liquid and gaseous, Example catalyst from temperature operating easily condensable reaction hour catalyst from hour products OC grams per normal cubic meter of Co + H2 2 needle iron ore ........... 240 200 I56 3 unpurified nitrate ...... 240 200 157 4 crystal Nitrate ............. 246 200 38 5 pa nitrate .............. 246 200 17

Claims (2)

PATENT CLAIMS: I. Process for the production of hydrocarbons from carbon oxide and hydrogen using wrought iron or mild steel Catalysts produced according to patent 763 307, characterized in that uses a catalyst made from a solution of wrought iron or mild steel in nitric acid by evaporation and thermal decomposition of the nitrates without preceding Removal of dissolved impurities is made using the iron nitrate if necessary, has received activating additives, but no longer their amount than 0.5%, based on the amount of iron. 2. Modification of the method according to claim I, characterized in that that catalysts are used in their manufacture instead of metallic Iron such iron nitrates are used by dissolving iron minerals in nitric acid without removing the dissolved impurities.