DE697066C - Extraction of carbon disulfide from thiocarbonate liquors - Google Patents

Description

Extraction of carbon disulfide from thiocarbonic liquors during leaching of hydrocarbons, especially fuels such as benzene or gasoline, means Alkali sulphide liquors to remove the carbon disulfide present in the hydrocarbons, especially in processes in which the treatment of the hydrocarbons with Alkali sulfide is carried out in the presence of orthothiocarbonate, thiocarbonate liquors fall all containing carbon disulfide in bound form, according to the invention should be obtained from them.

The recovery of the carbon disulfide makes the cleaning process of hydrocarbons more economical.

When heating ammonium dithiocarbonate liquor, simple Heating the carbon disulfide can be obtained. however, this is the type of carbon disulfide production not possible with alkali thiocarbonate liquors, as they do not contain carbon disulfide when heated, but hydrogen sulfide is split off with simultaneous formation of alkali metal carbonate. In addition, these aqueous solutions of the alkali thiocarbonates also result from Addition of acid no carbon disulfide, as the corresponding thiocarbonic acids that do not break down into carbon disulfide when heated.

According to the invention it is proposed to use carbon disulfide from thiocarbonate solutions, especially the alkalis, which are used in the removal of carbon disulfide from hydrocarbons incurred in the presence of orthothiocarbonate, thereby winning that the solutions with salts of the metals of the ammonium sulphide or hydrogen sulphide group, in particular oxygen-containing salts, preferably in, treated with heat, with a Decomposition of the thiocarbonate salts with splitting off of carbon disulfide and development of hydrogen sulfide proceeds quantitatively and the carbon disulfide is captured as well as optionally also the hydrogen sulfide.

If an altiminium salt is added to a thiocarbonate solution, the thiocarbonate decomposes at normal temperature, with carbon disulfide and hydrogen sulfide being split off. The same happens when a heat treatment is carried out at about 7o to 8o 'in the presence of zinc salts. At these temperatures the carbon disulfide is in each case completely driven off, so that it is possible to recover almost all of the carbon disulfide bound to the thiocarbonate. ib, d # Q "If, for. example, aluminum salts sic,>, 'are ineldung addition to zinc salts especially for dW carrying out the method according to the Ah., a Thiocarbonatlauge ZU7 set, the escaping Schwefflkohlenstoff in a suitable solvent absorbed and the hydrogen sulfide in the sodium hydroxide solution collected. one can remove the hydrogen sulfide and then restrain the carbon disulfide in a liquid or solid waste sorbent also first in a known manner. in the case of use of zinc salts, a particular separation of the hydrogen sulfide from the carbon disulfide is not necessary since the resulting hydrogen sulphide is bound to zinc as sialfid and the carbon disulfide can thus be obtained in pure form.

The resulting sodium sulphide liquor can be washed out further of carbon sulfur can be used. It is therefore a continued one Carrying out the process only at the beginning of the decomposition period, the addition of a certain amount of salt solution of the metals of sulfur ammonium or. the hydrogen sulfide group necessary, as this can be recovered by dissolving the precipitate using acids can be.

When using aluminum salts it has been shown that an excess salt solution is favorable, since the excreted hydro- ". 3, d -colloidal in solution goes. The thiocarbonate enclosed by the hydroxide is thereby subjected to decomposition made more accessible. In this form, too, the hydroxide is more easily left in acid to solve.

Embodiment i On 100 volumes of Diner 251% potassium thiocarbonate solution, corresponding to a content of 10.2o parts by weight of carbon disulfide, i2o volumes of a 100% aluminum sulfate solution were applied, i.e. an excess of 20%. In order to avoid a stormy evolution of gas, the aluminum sulfate solution was fed to the thiocarbonate solution in a slow flow. After the evolution of gas had subsided, the reaction mixture was heated to about 70 to 50 ° in order to completely drive off the carbon disulfide. The escaping carbon disulfide was dissolved in benzene and sulfur "f, '#, l # Vasserstoff. Collected in sodium hydroxide solution. I # i1 were recovered 9.83 parts by weight eSdiwef, elkohl # e, nstoff, equal to a yield of 96.4" / ,.

Embodiment 2 130 volumes of a 20% zinc sulfate solution were used on 100 volumes of a 25% strength potassium thiocarboilate solution, corresponding to a content of 10.2 parts by weight carbon disulfide. When heated to about 70 to 80 °, the thiocarbonate decomposed and the carbon disulfide which escaped in pure form was collected in benzene. 9.96 parts by weight of carbon disulfide were recovered, equal to a yield of 98 1101

Claims (2)

PATENT CLAIMS: i. Process for the production of carbon disulfide and optionally hydrogen sulfide from thiocarbonate liquors, especially those caused by the action of alkali sulfide on carbons, hydrogen, especially fuels, such as benzene, gasoline and the like, in the presence of small amounts of orthothiocarbonate were, characterized in that the solutions with salts, in particular oxide salts of metals of the ammonium sulfide or hydrogen sulfide group, in particular Aluminum or zinc, optionally in the heat with elimination of vaporous ones Carbon disulfide and hydrogen sulfide decompose - ", which then in to earth can be obtained in a known manner. 2. The method according to claim i, characterized in that when using salts, the hydroxides of which form colloidal solutions, in particular aluminum salts, an excess of salt solution is used. 3. The method according to claim i and 2, characterized in that when using salts which form a sulphide with the evolved hydrogen sulphide, in particular zinc salts, the sulphide formed is added with acid in order to obtain the released hydrogen sulphide and the sodium sulphide liquor formed for further washing out of carbon disulfide ans hydrocarbons are used.