Food grade carbon dioxide is produced from oxyfuel fired glassmaking furnace waste gas by a series of steps including quenching the waste gas with aqueous quench liquid, dry-filtering sulfur salt from the gas, scrubbing the filtered gas with aqueous carbonate to convert the remaining sulfur dioxide to an aqueous sulfite suspension and using the suspension as part or all of the above-mentioned aqueous quench liquid, contacting the sulfur dioxide-free waste gas with ammonia in the presence of a catalyst that selectively converts nitrogen oxides to nitrogen, thereby removing substantially all nitrogen oxides from the waste gas, and distilling the resulting waste gas stream thereby producing high purity liquid carbon dioxide and producing an off-gas, which is recycled to the furnace as fuel.

Process for the production of high purity carbon dioxide

A process is described for the selective catalytic reduction of nitrogen oxides, in which the nitrogen-oxide-containing gases are mixed with the reducing agent and the mixture is passed at 150 to 600@C and a flow velocity of 0.5 to 5 cm/s through at least one catalytically acting filter element which has a thickness of 2 to 20 mm and comprises a ceramic support material and the catalytically active substances. The ceramic support material is composed of Al2O3, SiO2 and/or SiC and of an inorganic binder and has the form of felts, webs or sintered bodies which are doped with the catalytically active substances.

Process for the selective catalytic reduction of nitrogen oxides

The invention relates to a process for the manufacture of a catalyst for the reduction of nitrogen oxides in exhaust gases. The catalyst contains a metal oxide. The catalyst is preferably used for catalytic reduction with ammonia. The process comprises screening a natural goethite iron ore to the required grain size and then treating the ore with sulfuric acid. Subsequently, the goethite iron ore is heated to a temperature which approximately equals the temperature at which it will be used in the catalytic reaction.

Process for the manufacture of a catalyst for the reduction of nitrogen oxides in exhaust gases

Method for reducing the content of nitrogen oxides NOx and nitrous oxide N2O in an input gas, comprising the steps of: treating said gas with a first amount of a NOx reducing agent in a first de-NOx catalytic bed; treating the effluent of said first de-NOx catalytic bed in at least one de-N2O catalytic bed for removal of N2O; treating the effluent of said at least one de-N2O catalytic bed with a second amount of a NOx reducing agent in a second de-NOx catalytic bed.

A METHOD AND APPARATUS FOR REMOVING NOx AND N2O FROM A GAS

A process for preparing nitric acid may involve vaporizing ammonia in at least one first ammonia vaporizer to produce an ammonia gas, oxidizing this ammonia gas to nitrogen dioxide in a plant section of a nitric acid plant, and absorbing the nitrogen dioxide in water to produce nitric acid. A residual gas containing nitrous gases may be taken off from the plant section of the nitric acid plant and conveyed to a residual-gas cleaning apparatus. The residual gas containing nitrous gases may be reduced by means of ammonia in the residual-gas cleaning apparatus, wherein ammonia-containing wastewater obtained in the at least one first ammonia vaporizer may be conveyed to the residual-gas cleaning apparatus. Such a process may eliminate or at least substantially reduce ammonia-containing wastewater. Furthermore, a plant can be used in this process for preparing nitric acid.

Process and plant for preparing nitric acid

Exhaust gases containing residual nitric oxide constituents from a processing operation are maintained at an elevated pressure, heated to from 260° to 340° C., and subjected to catalytic reduction with ammonia to produce purified exhaust gases. The pressure of the thus purified exhaust gases is then relieved in an expansion turbine.

Karl Heinrich Laue

Papers

Process for removing nitric oxides from processing exhaust gases