The disclosure is of gas-cleaning apparatus comprising a chamber having a downwardly vertical gas and fluid flow path, with the gas and fluid moving at high velocity. One or more layers of solids is disposed across the path of gas and fluid flow, and these solids and the spaces between them act as multiple venturi scrubbers and impingement surfaces so that the gas is cleaned by agglomeration and absorption. A vibrator is coupled to the layers of solids for vibrating them to prevent matter removed from the gas from adhering thereto and blocking the passages therebetween. Also disclosed is a centrifugal cyclone separator, adapted to be coupled to the output of the above-described gas scrubber, comprising an upright chamber containing a rotatable cylinder carrying blades on its outer surface, the free edges of the blades being positioned close to the inner wall of the chamber. The blade configuration and high rotational velocity and long distance travel of the gases provide improved separating action. The above apparatus is utilized in a system for converting sulfur dioxide in the clean gas to sulfuric acid.

Air pollution control system

A system for removal of oxides of nitrogen from the waste gas produced by various combustion processes discloses thoroughly mixing the waste gas with ammonia by means of a static mixing element and then passing the resultant mixture through a catalytic reactor. The ammonia may be supplied by reacting a portion of the waste gas with natural gas in the presence of a catalyst.

Process for efficiently removing oxides of nitrogen from exhaust gas

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

The present invention is a process for the control of nitric acid plant stack opacity in the range from 0 to 10 percent during plant startup and shutdown. The process is a series of sequential steps which encompass maximizing pressure, water and air flow to the absorber and adding ammonia upstream of the catalytic combustor. The process is typically accomplished through an automatic control system.

Control of nitric acid plant stack opacity during start-up and shutdown

A method and apparatus for reducing nitric oxide in a gas with ammonia in the presence of a base metal catalyst pretreated with sulfur, selenium or a sulfur compound positioned in a reactor The catalyst is deposited on a substrate or confined between gas-permeable walls and arranged to form open channels through which the nitric oxide-containing gas thereby effects low pressure drop through the reactor

Method and apparatus for reducing nitric oxide

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

Apparatus for removing nitric oxides from processing exhaust gases

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.

Peter Dipl Chem Sauder

Papers

Apparatus for removing nitric oxides from processing exhaust gases

Process for removing nitric oxides from processing exhaust gases

Verfahren zur entfernung von stickoxiden und anlage zur durchfuehrung des verfahrens