Abstract:
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.
Abstract:
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.
Abstract:
A method for the recovery of a methane-rich natural gas from a natural gas containing, apart from methane, also hydrogen sulfide, carbondioxide, higher hydrocarbons and, in most cases, organosulfur compounds. According to the invention a hydrocarbon fraction of C.sub.4 hydrocarbons and higher is naturally removed from the natural gas which is then subjected to a selective scrubbing for the removal of hydrogen sulfide with a regeneratable extraction, of scrubbing liquid. Next a C.sub.3 fraction is removed, the remaining gas being scrubbed with a second regeneratable washing agent, for the removal of carbondioxide to leave the methane-rich gas.
Abstract:
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.
Abstract:
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.
Abstract:
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.
Abstract:
Process for the recovery of one or more components of a raw gas, absorbed by the scrubbing liquid during a physical gas scrubbing step, by expanding the laden scrubbing liquid, characterized in that the expanded, laden scrubbing liquid is stripped, before its final regeneration, with a gas consisting exclusively of one or more components of the raw gas and essentially free of the components to be recovered and to be scrubbed out.
Abstract:
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.
Abstract:
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.