Inorganic oxides for co2 capture from exhaust systems

Abstract

This invention relates to the utilization of regenerable water tolerant solid materials for the abatements of CO 2 emissions from internal combustion engine exhaust streams through repetitive sorption/desorption cycles. The system, which is designed to be used in a gasoline, lean gasoline, diesel passenger car, diesel truck, stationary engine with 50 Hz or 60 Hz electrical frequency, or a SOFC, will contain a solid sorbent which contains zirconium and will be able to reduce on board the average carbon emissions by up to 10 wt %. The preferred materials have been selected from the class of hydrotalcite type compounds and/or earth and alkaline earth zirconates.

1 . A system for the controlled capture, on board storage and release of carbon dioxide from engine exhaust stream which uses a regenerable, water tolerant solid inorganic oxide material, where the system is located upstream, downstream or within a catalytic converter and can be regenerated by heating to a temperature up to 800° C. 
     
     
         2 . A system as in  claim 1  specifically for use in a gasoline, lean gasoline, diesel passenger car, diesel truck, stationary engine with 50 Hz or 60 Hz electrical frequency, or a SOFC data (Solid Oxide Fuel Cell). 
     
     
         3 . A system as claimed in  claim 1  which contains a material which has at least 1 wt % of a zirconium based compound. 
     
     
         4 . A system as claimed in  claim 1  which contains a material which is based on a layered structure, preferably a layered double hydroxide or hydrotalcite. 
     
     
         5 . A system as claimed in  claim 1 , which contains a material which is based on lithium zirconate structure. 
     
     
         6 . A system as claimed in  claim 1  which contains a material which has at least 1 wt % of a lithium based compound. 
     
     
         7 . A system as claimed in  claim 1  which contains a material which contains at least 1 wt % of a lithium based compound, and 1 wt % of a zirconium based compound. 
     
     
         8 . A system as in  claim 1  which is regenerable by heating at temperatures between 300 and 800° C. 
     
     
         9 . A system as in  claim 1  which reduces the average carbon dioxide emissions emitted from the exhaust by at least 5 wt %. 
     
     
         10 . A system as in  claim 1  which reduces the average carbon dioxide emissions emitted from the exhaust by at least 10 wt %. 
     
     
         11 . A system as in  claim 1  which contains a material which is able to capture the carbon dioxide from an internal combustion engine with the consecutive formation of a layered structure. 
     
     
         12 . A system as claimed in  claim 1  which contains a material which is able to capture the carbon dioxide and after the contact with carbon dioxide will contain at least one carbonated layer for each structural unit. 
     
     
         13 . A system as claimed in  claim 1  where the carbon dioxide stored on board is equal to or less than the weight of a full tank of fuel.