Metallgesellschaft Aktiengesellschaft

Chemie Linz Aktiengesellschaft

Hans-Martin Stonner

Paul Wiesner

Fritz Wohler

Henning Buchold

Gert Ungar

Nikola Anastasijevic

Johann Schlauer

Friedemann Marschner

Alfred Schmidt

Matthias Linicus

Eilhard Hillrichs

Gerhard Hochgesand

Alfred Garber

Volker Brucken

Eberhard Julius Schlichting

Rainer Hartmann

Ernst Stoldt

Berthold Scholtz

Alan Sinclair

Fritz-Jurgen Gartner

Heinz Kahles

Gerd Mallok

Phenols are extracted from a phenol-containing waste water by means of two solvents A and B. The waste water is first of all passed through a first extraction zone, and then through a second extraction zone. To the first extraction zone a mixture of the solvents A and B is supplied, and into the second extraction zone at least one of the two solvents is introduced. From the first extraction zone, solvent-mixture loaded with phenols is withdrawn, phenols am separated therefrom, and the solvents are used again in at least one of the extraction zones. Solvent B is lower-boiling and has a lower water solubility at a temperature in the range from 10.degree. to 60.degree. C. than solvent A. Solvent B has a water solubility at 40.degree. C. of up to 2 wt.-% and a boiling point at 1 bar of 50.degree. to 100.degree. C., and it is miscible with solvent A. Solvent A has a boiling point at 1 bar of not more than 172.degree. C. and a water solubility at 40.degree. C. of not more than 5 wt.-%.

Process of extracting phenols from a phenol-containing waste water by

The wax ester is prepared from a liquid mixture which contains at least one fatty acid and at least one fatty alcohol. The fatty acid and the fatty alcohol contain 6 to 30 carbon atoms per molecule. The mixture is agitated at temperatures in the range from about 105.degree.to 300.degree. C. and is sprayed into a spraying zone. An atmosphere which contains water vapor is formed in the spraying zone and is removed at least in part. The mixture of fatty acid and fatty alcohol may be agitated in at least one stirred vessel preceding the spraying zone. A catalyst is preferably not added.

Process of preparing wax ester

An aqueous solution which contains ammonium polysulfide is proportionally added to the sour water, which contains cyanide ions, ammonium ions, and sulfide ions. At least part of the cyanide ions contained in the sour water is converted to thiocyanate ions by the ammonium polysulfide. The solution which contains ammonium polysulfide is prepared from an aqueous solution by oxidation in an electrochemical cell. That aqueous solution may consist entirely or in part of sour water.

Process for decreasing the corrosiveness of a sour water

Fatty acids and/or fatty acid derivatives as well as hydrogen, fresh catalyst and a dispersion which contains used catalyst are supplied to the hydrogenating means, which are operated at temperatures in the range from 100.degree. to 400.degree. C. and under pressures in the range from 20 to 400 bars to produce a product stream, which contains fatty alcohols and used catalyst. A part of the product stream is circulated. A first partial stream Is withdrawn at a controllable rate from the circulating stream and is passed through a separator. A product which is rich in fatty alcohol and a dispersion which contains used catalyst are separately delivered by the separator. The dispersion is recycled to the hydrogenating means. A second partial stream is withdrawn at a controllable rate from the circulating product stream. Used catalyst is separated from the second partial stream and is removed from the process. The rate at which used catalyst is fed to the hydrogenating means can be increased in that the rate of the second partial stream is decreased.

Process of controlling the rate at which used catalyst is recycled to

A condensate which contains cyanide ions, hydrogen sulfide and ammonia is first partly purified by stripping with water vapor and stripped-off gases are then scrubbed with an absorbent. The laden absorbent contains 50 to 300 grams ammonia and 10 to 100 grams hydrogen sulfide and is at a temperature of 70.degree. to 150.degree. C. and has a pH value of at least 9. Sulfur is added to the condensate or the laden aqueous absorbent in a quantity which is at least 0.8 times the quantity that is stoichiometrically required to convert the cyanide ions to thiocyanate ions. The sulfur may be produced from hydrogen sulfide and oxygen, preferably in the presence of an oxidation catalyst. Alternatively, the sulfur may be added to a liquid which contains 10 to 400 grams ammonia and/or ammonium ions per liter so that ammonium polysulfide is formed. That solution is mixed with the liquid that contains cyanide ions.

Process for the treatment of an aqueous condensate

Desulfurized hydrocarbons are reacted with water vapor on catalysts at temperatures of 700.degree. to 1200.degree. C. to form a high-hydrogen product gas, which is separated in a pressure-swing adsorber into purified hydrogen and a separated gas, which contains substantially carbon oxides and methane. The purified hydrogen is supplied to a hydrogenating plant, which is operated at temperatures in the range of 250.degree. to 500.degree. C. and pressures of 200 to 400 bars. High-hydrogen gas from the hydrogenating plant flows in a pipeline through a heater and is then recycled to the hydrogenating plant. The heater consists of a fuelfired reheater, in which the separated gas is used as a fuel. The pipeline in which the high-hydrogen gas is recycled between the hydrogenating plant and the heater consists of an alloy steel, in which the carbon is combined in carbides with at least one of the alloying constituents chromium, molybdenum, tungsten or vanadium.

Process for heating hydrogen

In a process of recovering and cleaning catalysts in the continuous production of fat alcohols by a catalytic hydrogenation of fatty acids or fatty acid derivatives at temperatures of 240.degree. to 330.degree. C. and pressures of 200 to 700 bar in the presence of copper-chromium oxide catalysts, wherein the reaction is carried out in the presence of material which has been already reacted, the resulting dispersion is circulated through the filter which is due for cleaning until the contents of the stirring vessel is free of solids and the filter cake is substantially free of product, the liquid from which solids have been removed is separated into cleaning liquor and recovered product by a simple sedimentation in a liquid-liquid separator or by a distillation, the recovered product is fed to the main product, the catalyst which is moistened with the cleaning liquor and substantially free of product is withdrawn and, if required, is dryed.

Production of fatty alcohol with recovery thereof from the hydrogenation

Gas condensates formed from the gases obtained from coal gasification, cokefication, or carbonization are extracted with an acid- and alkali-resistant solvent, e.g. organic esters or ethers, and phenols are thereby removed. The extract is separated into solvent and phenolic phases and the solvent is recycled to the extraction process. The same solvent is used in a greater quantity for a second stage treatment of the gas condensate to preferentially remove tar bases and again the solvent and tar base phases are separated with recycling of the solvent. Residual solvent, acid gases and other volatile components are removed from the gas condensate by distillation and/or stripping with the ammonia and acid gases being separately recovered. The gas condensate is thereafter subjected to biological cleaning, e.g. by a biological oxidation.

Process for reducing biological oxygen demand of gas condensate

Mono and polyvalent phenols are recovered from gasified coal by scrubbing the phenol-containing gas with water, separating the extracted phenols into a monovalent phenol-rich fraction and a polyvalent phenol-rich fraction and recovering the monovalent phenols separately from the polyvalent phenols by solvent extraction.

Process of scrubbing polyvalent phenols from gas

A process for removing phenols from waste water resulting from the gasification or carbonization of coal and containing CO.sub.2, H.sub.2 S and NH.sub.3, comprising mixing the waste water with a low-boiling organic solvent, separating the mixture into a solvent layer and an aqueous layer, stripping off from the aqueous layer under superatmospheric pressure the vapors of CO.sub.2, H.sub.2 S and organic solvent contained therein, then stripping off from the aqueous layer the NH.sub.3 contained therein leaving a refined aqueous product layer suitable for discharge, scrubbing the stripped vapors under superatmospheric pressure with a portion of the cold refined product to remove organic solvent contained therein, condensing part of the solvent and separating it under superatmospheric pressure, and scrubbing the remaining acid gases still containing ammonia and solvent with recirculated cooled raw phenol to remove the ammonia and solvent.

Removing phenols from waste water

Mono and polyvalent phenols are recovered from gasified coal by scrubbing the phenol-containing gas with water, separating the extracted phenols into a monovalent phenol rich fraction and a polyvalent phenol rich fraction and recovering the monovalent phenols separately from the polyvalent phenols by solvent extraction.

Process of scrubbing polyhydroxy phenols from gas

Pure, concentrated ammonia is recovered from aqueous liquors by stripping off gas water, de-acidifications, scrubbing and withdrawing ammonia from the top of a scrubbing column.

Continuous process for recovering pure, concentrated ammonia

A process for the recovery of pure concentrated ammonia in which the gaseous products of coal gasification or degassing are condensed or are washed with water to produce a phenolic-containing liquid phase (gas water), this liquid is dephenolated by extraction with a solvent, the phenol is recovered from the solvent and the gas is driven from the liquid phase. The gas is washed with circulated phenol and residual solvent is eliminated therefrom after NH.sub.3 is removed by washing.

Process for producing pure concentrated ammonia

Dissolved organic compounds in waste water resulting from coal degassing or gasification processes are removed by extraction with a solvent which is substantially water-immiscible, the solvent residues in the waste water are removed by inert gas scrubbing, and CO.sub.2, H.sub.2 S and NH.sub.3 in the waste water are removed by heating and steam contacting. NH.sub.3 is effectively removed in a steam gas/liquid contacting column by feeding the condensed head product of the column back to the top portion thereof, withdrawing a portion of the condensate from the column at a level intermediate the top and bottom portions of the column, treating the condensate in admixture with waste water containing CO.sub.2, H.sub.2 S and NH.sub.3 in a deacidification gas/liquid contacting column, and feeding the sump product of the deacidification column to the first column at a region below the region at which the condensate is withdrawn but intermediate the top and bottom portions of the NH.sub.3 -removal column.

Process for the treatment of phenol-containing waste water from coal

A liquid-liquid counterflow extractor has a plurality of stacked stages each of which is provided with a mixer and a separator, the stages being traversed in succession by an upwardly flowing relatively low-density (light) phase and downwardly by the relatively high-density (heavy) phase. The separations of adjacent stages have lateral outlets which can be selectively connected to the inlets of a pump which can serve to displace one of the phases from one stage to another or to circulate a phase within one stage.

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Schwalbach, Germany

Hans-Martin Stonner