Linde Aktiengesellschaft

Huls Aktiengesellschaft

Vniigaz

Gerhard Ranke

Horst Weiss

Heiner Landeck

Michael Heisel

Hans Becker

Friedrich Siegert

Dietrich Maschmeyer

Heinz Karwat

Gunter Weber

Wolfgang G Forg

Peter Grimm

Walter Scholz

Ulrich Schrader

Georg Bengeser

Tran A Tvan

Paul Kumman

Alexej V Frolov

Elmar Diehl

Peter Butz

Alexander I Grizenko

Boris G Bergo

Robert Walter

Dieter Roth

Process for the removal of HCN from gas mixtures

For the selective removal of sulfur from gases, a physical scrubbing agent is used, comprising a heterocycle having five or more ring atoms, which contains two heteroatoms, one of which is nitrogen and the other of which is oxygen or nitrogen; and the heteroatoms in the rings of even member number of atoms occupy; one of the positions from 1,2 to 1,n/2 and, in the rings of uneven member number of atoms occupy one of the positions from 1,2 up to 1, (n-1)/2. Further, the nitrogen heteroatom(s) present in the ring is/are either double bonded or single bonded but, if single bonded, the nitrogen is organo-substituted.

Process for the selective removal of inorganic and/or organic sulfur

For regenerating a scrubbing agent loaded with H.sub.2 S and/or COS, as well as optionally with other raw gas components to be recovered, the loaded scrubbing agent is mixed, preferably without prior heating, with an oxidatively acting solvent that is immiscible with the scrubbing agent, and the H.sub.2 S dissolved in the immiscible solvent is converted to elementary sulfur.

Process for regenerating a scrubbing agent loaded with H.sub.2 S and/or

In a process for the purification of coal gasification gases, synthesis gas and fuel gas are simultaneously produced. In order to obtain a fuel gas rich in CO.sub.2, capable of handling fluctuations in demand, and to produce at the same time a highly concentrated H.sub.2 S fluid fraction, a portion of the crude gas, scrubbed to synthesis gas purity, is utilized for stripping out CO.sub.2 under pressure from scrubbing medium loaded exclusively with CO.sub.2. The partially stripped CO.sub.2 -loaded scrubbing medium is employed for the concentration of sulfur compounds in an H.sub.2 S/COS-loaded scrubbing medium.

Process for the purification of crude gases with simultaneous production

For the fractionation of a hydrocarbon mixture, e.g., natural gas rich in a C.sub.2+ fraction, the hydrocarbon mixture is partially condensed and the thus-produced gas/liquid mixture is separated in a distillation column to produce a gaseous overhead fraction containing lighter hydrocarbons and a liquid bottoms product containing heavier hydrocarbons. In the upper column section, the gas is scrubbed with a physical scrubbing agent which is preferably a part of the bottoms product. A gaseous stream is withdrawn from the middle of the column to give the C.sub.4+ bottoms product the proper composition for scrubbing purposes. The scrubbing agent is also subcooled to lower the vapor pressure, preferably by a cooler liquid withdrawn from the column.

Fractionation of a hydrocarbon mixture

For scrubbing C.sub.2+ or C.sub.3+ hydrocarbons from gaseous mixture containing hydrocarbons and/or inerts like H.sub.2 N.sub.2, CO and possibly acid gases, e.g. CO.sub.2 H.sub.2 S, COS e.g. natural gas and the like, the scrubbing medium consists essentially of compounds having one to two rings formed by 5 or 6 carbon atoms, wherein the compounds comprise, in total, at least 9 and at most 17 carbon atoms, and the rings are saturated unsaturated or partially saturated especially alkylated ring compounds of 9 or 10 carbon atoms, e.g. isomeric forms of trimethylbenzene, propylbenzene, propylcyclohexane, tetrahydronaphthalene, decahydronaphthalene.

Scrubbing of gas to recover light hydrocarbons

For scrubbing C.sub.2+ or C.sub.3+ hydrocarbons from gaseous mixture containing hydrocarbons and/or inerts like H.sub.2' N.sub.2, CO and possibly acid gases, e.g. CO.sub.2 H.sub.2 S, COS e.g., natural gas and the like, the scrubbing medium consists essentially of compounds having one to two rings formed by 5 or 6 carbon atoms, wherein the compounds comprise, in total, at least 9 and at most 17 carbon atoms, and the rings are saturated unsaturated or partially saturated especially alkylated ring compounds of 9 or 10 carbon atoms, e.g. isomeric forms of trimethylbenzene, propylbenzene, propylcyclohexane, tetrahydronaphthalene, decahydronaphthalene.

In a process for the regeneration of a scrubbing medium which has been utilized in a scrubbing operation and therein loaded with scrubbed-out components, the scrubbing medium is expanded and regenerated and hence can be reused in the scrubbing operation. In order to be able to subject expansion gases obtained during the expansion to an after-treatment under elevated pressure, or to be able to discharge these expansion gases under a higher pressure, the loaded scrubbing medium is expanded in at least two stages. Expansion in one stage is performed by means of a liquid-jet compressor and the expansion gases of a subsequent expansion stage are brought to an elevated pressure by means of the liquid-jet compressor.

Process for removing undesirable components from gases

A process is disclosed for obtaining C.sub.2+ or C.sub.3+ hydrocarbons from hydrocarbon-containing gaseous mixtures by pressure scrubbing with a physically acting solvent selective for C.sub.2+ and, respectively, C.sub.3+ hydrocarbons. The solvent, after loading, is regenerated and reused. In order to avoid impurities in the C.sub.2+ and, respectively, C.sub.3+ product in an economical and energy-saving way, the loaded solvent is subjected to expansion to a pressure lying below the critical pressure of the solvent-gas mixture, and to heating and partial evaporation in order to drive off concomitantly dissolved inert gases. The solvent, reduced in its content of inert gases, is then to be passed on to regeneration. The process is advantageous, in particular, in cases where crude gases are to be processed which exhibit a low concentration of components to be scrubbed out.

Process for obtaining C.sub.2+ or C.sub.3+ hydrocarbons from gaseous

The combined production of ammonia and urea by the reaction of gases containing hydrocarbons with steam is conducted by using a steam reformer, downstream secondary reformer, and shift converter. The ammonia synthesis gas (hydrogen, nitrogen and carbon dioxide) is subjected to a high pressure scrubbing step with a physical solvent, to remove the acid impurities, especially CO.sub.2. The pressure on the loaded solvent is reduced to a first intermediate pressure for degasing of the coabsorbed inerts and then to a second intermediate pressure for removal of the bulk of the absorbed CO.sub.2, which is then used for urea synthesis. To remove residual CO.sub.2, the solvent is stripped with air and the resultant air stream containing the stripped residual CO.sub.2 is fed to the secondary reformer.

Integrated production of ammonia and urea

Process for the treatment of CO-rich gases incurred in the manufacture of phosphorus, which gases contain impurities like water, and compounds of sulfur, nitrogen and phosphorus. The gas is passed through regenerators for the purpose of removing impurities. In this manner, a product gas is obtained from which impurities have been condensed or frozen.

Process for the treatment of gases incurred in the manufacture of

To regenerate a physical solvent, loaded with sour gases, especially CO.sub.2 and H.sub.2 S, the loaded solvent is treated with a stripping gas and/or is expanded to separate absorbed CO.sub.2 and the resultant solvent is subjected to thermal regeneration to desorb H.sub.2 S. To reduce energy requirements during regeneration, the CO.sub.2 desorption is conducted on at least two different temperature levels, the second being for example 30.degree.-80.degree. C. higher than the first, with the first being conducted, e.g., at about those low temperatures conventional to low temperature absorption systems.

Multiple temperature level regeneration of CO.sub.2 from physical solvent

For the separation of ethane and higher hydrocarbons from a high pressure incoming gas containing hydrocarbons, the raw gas is cooled and expanded in several stages and the condensates that are produced are fed to a rectifying column to provide an overhead gaseous product essentially consisting of methane and a bottoms product consisting essentially of ethane and higher hydrocarbons. To save energy, the raw gas and/or the product streams are heat exchanged in parallel streams under different pressures, the cooled high-pressure gas is work-expanded and the condensates produced by cooling and expansion are fed separately to the rectifying column.

Parallel stream heat exchange for separation of ethane and higher

For the purification of hydrocarbon-containing, e.g., methane raw gases containing H.sub.2 S and CO.sub.2, the raw gas is dried, and separated by rectification into a hydrocarbon-rich overhead fraction containing some H.sub.2 S and CO.sub.2 and into a bottom fraction consisting essentially of H.sub.2 S and CO.sub.2. The overhead product is freed, in a first scrubbing column, of the acidic components with a physical acting scrubbing medium selective for H.sub.2 S and COS as against CO.sub.2, e.g., polyethylene glycol ether or toluene. The bottom product from the rectification step is vaporized and selectively desulfurized in a second scrubbing column with the same scrubbing medium, and the scrubbed gas from the second scrubbing column is discharged as CO.sub.2 under pressure.

Separation of CO.sub.2 and H.sub.2 S from hydrogen containing gas

A process for the simultaneous removal of H.sub.2 S, SO.sub.2 and elemental sulfur from gaseous mixtures, comprises treating the gaseous mixture with a solvent. After the solvent becomes loaded with the components to be removed, it is regenerated and reused. In order to obtain savings in costs and energy, the sulfur is separated from the loaded solvent by lowering the temperature thereof. In this way, chemical regeneration of the scrubbing medium takes place within the cycle eliminating the requirement for outside regenerating apparatus.

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Pocking, Germany

Gerhard Ranke