Linde Aktiengesellschaft

Linde Akitengesellschaft

Gerhard Linde

Michael Heisel

Claus Schliebener

Wolfgang Kristof

Claus Schlebener

Peter Haeussinger

Hans Becker

Freimut Marold

Peter S Burr

Wolfgang Schmid

Guenter Rueckborn

Manfred Boelt

Apparatus for removal of deleterious gaseous components from a flue gas, the flue gas is cooled, optionally subjected to preliminary purification, and optionally depleted of SO.sub.2. It is then heated in at least one heat exchanger and is passed over a catalyst suitable for the conversion of nitrogen oxides, whereupon the purified hot flue gas is conducted over at least one further heat exchanger and is discharged in the cooled state. Ammonia is preferably added to the heated flue gas.

Apparatus for removal of nitrogen oxides from flue gas

A process is disclosed for the purification of a gaseous stream contaminated at least with CO.sub.2 and H.sub.2 S. The gaseous stream is preheated and subjected, in the presence of recycled SO.sub.2, to a catalytic conversion of H.sub.2 S into elemental sulfur. The thus-obtained sulfur is separated, and the residual gas, which contains at least H.sub.2 S, SO.sub.2, CO.sub.2, and water, is freed absorptively from SO.sub.2 after oxidative conversion of H.sub.2 S to SO.sub.2. It is proposed that the residual gas, after oxidative conversion of H.sub.2 S to SO.sub.2, is cooled in heat exchangers, preferably regenerators, and is subsequently scrubbed with a solvent consisting predominantly of tetraethylene glycol dimethyl ether.

Claus residual gas cleanup using tetraethylene glycol dimethyl ethers as

For the removal of deleterious gaseous components from a flue gas, the flue gas is cooled, optionally subjected to preliminary purification, and optionally depleted of SO.sub.2. It is then heated in at least one heat exchanger and is passed over a catalyst suitable for the conversion of nitrogen oxide, whereupon the purified hot flue gas is conducted over at least one further heat exchanger and is discharged in the cooled state. Ammonia is preferably added to the heated flue gas.

Removal of nitrogen oxides from flue gas

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

The invention refers to a process for the removal of undesirable gaseous components from hot flue gases incurred in the combustion of carbonaceous fuels. The flue gas is passed through regenerators for cooling and preliminary cleaning, and subsequently is scrubbed with a physically active solvent for SO.sub.2 absorption. After absorbing SO.sub.2, the solvent is subjected to regeneration and returned to the scrubbing process. For purposes of energy savings, it is suggested to heat exchange the hot flue gas in the regenerators with atmospheric air to cool it to temperatures between 0.degree. and 60.degree. C., and to scrub at this temperature with a solvent consisting predominantly of tetraethyleneglycol dimethylether. The process of the invention permits utilization of the exhaust heat of the flue gas to be purified.

Process for removal of undesirable gaseous components from hot flue gases

For producing elemental sulfur, SO.sub.2 is dissolved in a regenerable solvent, which is treated with a reducing agent, and the thus-formed sulfur is separated from the solution.

Integrated scrubbing of SO.sub.2 and production of sulfur

A mixture of gases containing hydrogen and at least one further component, for example nitrogen and argon, is enriched in hydrogen in a separation stage by adsorption, or cooling and partial condensation and/or rectification and/or scrubbing. Upstream of this separation stage, at least part of the hydrogen is separated by membrane diffusion, thereby resulting in a highly improved process as compared to using either the separation stage or membrane diffusion alone, especially in connection with gaseous mixtures having components which are to be used at high pressures, e.g., a purge gas from an ammonia synthesis gas process.

Process and apparatus for the separation of a mixture of gases

For separating CO.sub.2 from CO.sub.2 -containing gases, especially stack gases and/or blast furnace gases, dimethylformamide is employed as a physical scrubbing medium to ensure high CO.sub.2 purity. After absorption of CO.sub.2, the DMF is regenerated and returned into the scrubbing stage. Dimethylformamide is utilized as the scrubbing medium.

Process for separation of CO.sub.2 from CO.sub.2 -containing gases

A method of recovering at least two product fractions each highly enriched in a respective component of a gas mixture containing at least such components are recovered by separating a stream of the mixture into at least two partial streams and passing this stream separately through respective beds of respective adsorbents and selectively retaining at least one component from each mixture so that the respective product fractions emerge from the adsorbents highly enriched in respective components of this mixture, each adsorbent for a particular one of the fractions has a composition that retains at least one component in which the other fractions is enriched.

Adsorptive method for the separation of a gas mixture

In a process for the removal of sulfur dioxide and nitrogen oxides, the waste gas is cooled and scrubbed with a physical absorbent selective for sulfur dioxide. The nitrogen oxides are catalytically removed from the waste gas by reaction with ammonia, which is added to the waste gas prior to the scrubbing step. The catalyst packing is disposed in the same housing and is at the hot end of a regenerator for cooling the waste gas and is arranged upstream of the regenerator packing. The cooling is conducted to the dew point so as to dissolve residual ammonia, and air is used to remove the ammonia during regeneration, the resultant heated air being primarily used in the combustion zone.

Removal of undesirable gaseous components from a hot waste gas

To prevent disruptions in downstream processes due to non-uniform flows arising from the switching operation in two interchangeable regenerator systems, both the feed of a cold fluid to the cooled regenerator and the feed of a hot fluid to the heated regenerator are interrupted, the hot fluid is then introduced into the cooled regenerator while the cold fluid is first conducted through a heat accumulator connected in parallel with the regenerators; a portion of the fluid heated in the heat accumulator is fed into the heated regenerator to purge residual hot fluid therefrom and subsequently the cold fluid is passed in its entirety through the heated regenerator. Particular application is in preventing disruption in the flow, composition and temperature of air of combustion preheated by flue gas.

Method for reversing two regenerators

For removing undesired gaseous components, e.g., SO.sub.2, from hot combustion gases (from carbonaceous fuels) by scrubbing with a regenerable absorbent, the scrubbing is conducted with a liquid physical absorbent, e.g., dimethylformamide, at a temperature less than 0.degree. C. The cooling requirements of the scrubbing process are supplied by means of an absorption-type refrigeration unit. The hot combustion gases, prior to scrubbing, are cooled in indirect heat exchange, first with air in an upper temperature range cooling zone, and then with cold combustion gas purified by the scrubbing in a lower temperature range cooling zone. The resultant heated air is used in part as (a) air for combustion, and/or in part as (b) an energy source for the operation of the absorption-type refrigeration unit. A heat pump may be used to supplement the said refrigeration unit. Additionally, the resultant heated air can also be used in part as (c) an admixture to the scrubbed combustion gas mixed, and/or in part as (d) a purging gas for regenerating dessicators arranged in the undesired gaseous components (e.g. SO.sub.2) stream from a regenerator wherein the liquid physical absorbent is regenerated to be recycled to the scrubbing stage.

Removal of undesired gaseous components from hot waste gases

In the obtaining of oxygen from air by low-temperature rectification in a double rectification column by compressing the air to be fractionated into higher and lower pressure partial streams; cooling said partial streams in indirect heat exchange with a nitrogen-enriched gaseous stream from the rectification column; and introducing the partial stream of the air to be fractionated which has been compressed to the higher pressure into the lower part of the high pressure column,

Split pressure feed for the selective production of pure oxygen from air

For removing undesired gaseous components, e.g., SO.sub.2, from hot combustion gases (from carbonaceous fuels) by scrubbing with a regenerable absorbent, the scrubbing is conducted with a liquid physical absorbent, e.g., dimethylformamide, at a temperature less than 0.degree. C. The cooling requirements of the scrubbing process are supplied by an absorption type refrigeration unit. The hot combustion gases, prior to scrubbing, are cooled in indirect heat exchange, first with air in an upper temperature range cooling zone, and then with cold combustion gas purified by the scrubbing in a lower temperature range cooling zone. The resultant heated air is used in part as (a) air for combustion and in part as (b) an energy source for the operation of the refrigeration unit. A heat pump may be used to supplement the absorption type refrigeration unit. Other aspects include, for example, special regenerator design and absorbent regeneration steps.

A process for the separation of a low-boiling gaseous mixture by low-temperature rectification, comprising the steps of:

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Gerhard Linde