METHOD OF REGENERATING ALIPHATIC HYDROCARBON DEHYDROCYCLODEMERIZATION CATALYSTS Russian patent published in 2006 - IPC B01J29/90 B01J29/40 

FIELD: industrial organic synthesis catalysts.

SUBSTANCE: invention relates to regeneration of silica powder-containing catalysts with SiO₂/Al₂O₃ ratio at least 12, which are deactivated by coking occurring during aliphatic hydrocarbon dehydrocyclodemerization reaction. Regeneration process comprises preliminary nitrogen purge of reactor system to remove hydrocarbons until their content drops below 0.5%, treatment of catalyst at 300-550°C and pressure 0.1-2.0 MPa with catalyst-regeneration gas in the form of nitrogen-oxygen mixture pumped through closed regeneration circuit, withdrawal of a part of combustion products and moisture formed during coke combustion reaction, wherein regeneration gas loss is continuously recompensed to maintain specified working thermobaric conditions in the regeneration circuit. Simultaneously, oxygen content in regeneration gas is stepwise raised from 0.1 to 21 mol % followed by ageing of catalyst under each step conditions. Regeneration gas utilized is emission gases from process furnaces used to preheat feed for various chemical processes and operated with the main-pipeline natural gas, which emission gases are processed in mixture with said main-pipeline natural gas in flow-type reactor on metal block catalyst, wherein concentration of natural gas (methane) in mixture with emission gases should be 2.75, 2.4, and 0.5 vol % for three regeneration gas compositions used in regeneration cycle, which, at regeneration gas intake 40 m³/h used to replenish process flowsheet, will require consumption of natural gas for preliminary treatment of emission gases on metal block catalyst prior to being fed into regeneration circuit 1.1, 0.96, and 0.2 m³/h, respectively.

EFFECT: reduced power consumption due to eliminated use of pure nitrogen in catalyst regeneration stage.

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