Linde Aktiengesellschaft

Sasol Technology (pty) Limited

Vniigaz

Hans Becker

Heinz Bauer

Gerhard Ranke

Horst Weiss

Walter Scholz

Herwig Landes

Michael Heisel

Gerhard Linde

Karl Baur

Peter Grimm

Wolfgang Schmid

Hans Jungfer

Josef Sporer

Alexej V Frolov

Alexander I Grizenko

Boris G Bergo

Dieter Roth

The invention relates to a process for the recovery as a feedstock of an alpha-olefin from a mixture containing mainly hydrocarbon compounds, such as is obtained by Fischer-Tropsch-synthesis after an at least crude separation of components boiling higher and/or lower than the alpha-olefin, wherein tertiary olefins of the mixture, after superstoichiometrical addition of a low alcohol, are subjected to catalytic etherification and a stream derived by etherification is fed jointly with the alpha-olefin and the ethers produced and other high boiling reaction products to a distillative separation of components boiling higher than the olefin.

Process for the manufacture in pure form of 1-pentene or an alpha-olefin lower than 1-pentene

Process for the recovery of low molecular weight C.sub.2+ hydrocarbons

For recovery of low-boiling hydrocarbons by scrubbing, the crude gas mixture which contains low-boiling and high-boiling hydrocarbons, is treated with a scrubbing agent, by which the high-boiling components are scrubbed-out of the gas mixture. The loaded scrubbing agent, with the addition of liquid medium miscible with the scrubbing agent and which reduces the solubility for the scrubbed-out hydrocarbons, is regenerated and the completely regenerated scrubbing agent is recycled to the scrubbing. The regeneration is preferably divided into the following individual steps:

Gas absorption for separation of hydrocarbons

A process is disclosed for the purification of a gaseous mixture, for example, consisting essentially of hydrogen and containing impurities, e.g., carbon monoxide, methane and argon. The gaseous mixture is scrubbed with liquid nitrogen in a scrubbing column having two sections. In order to be able to process the residual gases formed during the scrubbing step, containing especially CO, argon and CH.sub.4, in a simple way and without great investment costs, liquid nitrogen is introduced in a quantity sufficient for an almost complete scrubbing out of the carbon monoxide, and a partial amount of the scrubbing liquid, enriched with carbon monoxide, is withdrawn between the upper and lower sections. The partial amount withdrawn is dimensioned so that the residual quantity of scrubbing agent delivered to the lower section of the scrubbing column is enough to scrub out the methane from the gaseous mixture, but yet also leaves a major portion of the carbon monoxide in the gaseous mixture.

Process for purifying a gaseous mixture

For regeneration of a loaded scrubbing agent, e.g. a polyethylene glycol ether containing H.sub.2 O and sour gases, the regeneration is conducted in a regeneration column equipped with a bottom heater and an overhead condenser, by stripping with vapor, e.g. stream provided by the heater vaporizing an aqueous condensate. After condensation of the vapor in the condenser, the stripped components are removed and the remaining condensate is recycled to the bottom part of regeneration column to avoid mixing the aqueous condensate with the loaded solvent. The condensate is fed directly into the bottom of the column or is fed into the line between the column and the bottom heater.

Regeneration of a scrubbing agent

In a process proposed for purification of a gas stream at elevated pressure by nitrogen scrubbing, the gas stream to be purified and the nitrogen scrubbing stream are initially cooled to low temperatures. The gas stream is then scrubbed with liquid nitrogen and the purified gas stream is mixed with cooled, high-pressure nitrogen to form a mixture in which nitrogen accumulates partly as a liquid phase. The mixture thus formed is then heated and the liquid nitrogen contained therein is evaporated. Prior to scrubbing, either the nitrogen scrubbing stream itself or a partial stream of the nitrogen scrubbing stream or another process stream under a pressure lower than the working pressure of the nitrogen scrubbing step is at least partly condensed and then pumped to a higher pressure. The condensation of this low-pressure stream provides a reduction in the temperature difference at the cold end of the heat exchangers upstream of the scrubbing step resulting in the reduction of the energy requirements of the process.

Process for purification of a gas stream by a nitrogen scrubbing

In the heat exchange of gases, e.g., flue gas, to cool or heat same, the gas is contacted directly with a heat transfer liquid in a first direct-contact heat exchanger, the gas is then subjected to a temperature dependent process step, e.g., SO.sub.2 absorption with a physical solvent, and the resultant process gas is reheated or recooled in a second direct-contact heat exchanger using the change in enthalpy that the heat transfer liquid has undergone in the first direct contact heat exchanger.

Process for the cooling or heating of a gas

A process is disclosed for the separation of undesirable e.g., SO.sub.2, from gaseous mixtures. Separation takes place by scrubbing in a first scrubbing column with a physical absorbing agent, which after absorbing the undesirable components is regenerated in a regenerating column and recycled to the first scrubbing column. During regeneration, a stream containing the undesirable components, as well as an inert gas components is obtained. The undesirable gas components and the inert gas components are separated in a further process e.g., a distillation stage. During this stage the undesirable components are removed as product and the inert gases, still containing a substantial fraction of undesirable components, are returned to the scrubbing stage. In order to economically recycle only a small amount of undesirable components back to the scrubbing column, during the recycling of inert gas the inert gases are at least partially separated in a second scrubbing column from the undesirable components by contacting with small stream of a physical absorbing agent. The inert gases are then passed to the first scrubbing column.

Process for separating undesirable components from gaseous mixtures

A process is disclosed for distillation and/or stripping in a column, the lower portion of which is heated and the upper portion of which is cooled. The heating and cooling facilities thereof are coupled with each other by means of a heat pump system. In order to reduce the energy input, the invention provides for driving the heat pump system by means of expansion of a gas or vapor, and with the gas or vapor, after expansion, utilized as the stripping gas in the column.

Process and apparatus for distillation and/or stripping

In a process for the regeneration of a loaded scrubbing medium in a regenerating column which is equipped with a bottoms heater and a heat condenser, the process involving stripping the loaded scrubbing medium with a vapor, wherein after condensation of the vapor in the head condenser the stripped-out components are removed and the remaining condensate is reintroduced to the regenerating column, the improvement comprising that the condensate, prior to being reintroduced to the regenerating column, is at least partially revaporized in a vaporizer and at least a portion of the condensate, prior to its at least partial revaporization in said vaporizer, is recycled into the regeneration column to a section located above the entrance point for the loaded scrubbing medium, is withdrawn again still above the entrance point for the loaded scrubbing medium, and is then passed to said vaporizer.

Process for regeneration of a loaded scrubbing medium

For the removal of sulfur compounds, especially H.sub.2 S, from gases that contain hydrocarbons, and/or CO.sub.2, the gases are scrubbed with a physical solvent, which is to be regenerated and reused. To obtain sulfur free of hydrocarbons, as well as a practically sulfur-free LPG fraction and optionally a C.sub.5+ fraction, an oxidizing agent is added to the solvent for reacting the sulfur compounds to elemental sulfur, and the sulfur is separated. The concomitantly absorbed hydrocarbons and/or CO.sub.2 can then be desorbed from the separated solvent by physical regeneration and can be recovered.

Removal of sulfur compounds from gases

For separating a higher boiling component from a liquefied gas, e.g., CO, rectification is used wherein a partial stream of the liquefied gas is vaporized, superheated, and then fed into the lower portion of a rectification column. The remainder of the liquefied gas in the liquid phase is fed into the upper portion of the rectification column. The rectification results in the higher boiling component being concentrated in the bottoms, and the overhead gas product being purified thereby. Additional purification is possible by liquefying and refluxing part of the overhead gas product, and in this case, it is possible to superheat the entire liquefied gas so as to obtain ultra high purity product.

Separation of higher boiling impurities from liquefied gases

Several impure gaseous streams, e.g., hydrogen-containing streams from a hydrogenation system, under different pressures and consisting essentially of the same components, are purified by multistage fractional condensation. The condensates separated from the gaseous streams at higher pressures are expanded to the lower pressure of another gaseous stream and introduced into the latter.

Integrated fractional condensation system for the purification of

An adsorption installation is employed for the purification of several crude gas streams. The individual crude gas streams are conducted separately from one another through the adsorbers in cyclic alternation. Preferably, an adsorber is regenerated only after all crude gas streams have been passed through the adsorber. The number of adsorbers utilized can be kept lower than in the separate purification of each individual crude gas stream.

Integrated adsorption system for the purification of separate crude gases

In the fractionation of a gaseous mixture under pressure containing methane, ethane, propane, inert gases, higher hydrocarbons, hydrogen sulfide, as well as carbon dioxide, e.g., a natural gas, the higher hydrocarbons are obtained by rectification as bottoms product, whereas methane, ethane, propane, hydrogen sulfide and carbon dioxide comprise the head product. The rectification is conducted in three stages, wherein the separated head product of the second stage forms at least in part the reflux of the first stage. By means of this process, a C.sub.4+ hydrocarbon condensate free of sour gases, as well as a C.sub.3- head fraction of high purity are obtained.

Growing community of inventors

Munich, Germany

Hans Becker