Vehicle powertrain with onboard catalytic reformer

摘要

Catalyst compositions suitable for use in the exhaust gas recycle stream of an internal combustion engine are provided. Such catalyst compositions typically provide significant amounts of methane in addition to syngas. A reformer incorporating such a catalyst for use in an exhaust gas recycle portion of an internal combustion engine powertrain is described. A powertrain incorporating such a reformer, a method of increasing the octane rating of an exhaust gas recycle stream, and a method of operating an internal combustion engine using methane-assisted combustion are also described.

主权项

1. A method of operating an internal combustion engine using methane-assisted combustion, comprising:
(a) providing an exhaust gas-containing mixture to an exhaust gas recycle reformer; the exhaust gas-containing mixture comprising recycled exhaust gas and a first hydrocarbon-containing fuel; (b) converting at least a portion of the exhaust gas-containing mixture in the presence of heat and a catalyst composition to a reformed gaseous mixture comprising CH4, CO, CO2, H2O, N2, and H2, said CH4 being present at a concentration greater than about 1.0 mol % CH4, based on the total moles of gas in the reformed gaseous mixture, said catalyst composition comprises a hydrocarbon-reforming catalyst, the catalyst composition having a hydrocarbon-reforming catalyst loading from 1.0 wt % to 10.0 wt %, based on the total weight of the catalyst composition, the metal of the hydrocarbon-reforming catalyst being rhodium or a combination of rhodium and platinum or a combination of rhodium and ruthenium; (c) introducing at least a portion of the reformed gaseous mixture and a second hydrocarbon-containing fuel into the engine, wherein said second hydrocarbon-containing fuel may be the same or different from the first hydrocarbon-containing fuel; (d) combusting the at least a portion of the reformed gaseous mixture and second hydrocarbon-containing fuel in the engine to form an exhaust gas, the exhaust gas comprising a first portion of the exhaust gas and a second portion of the exhaust gas; and (e) passing a first portion of the exhaust gas through a first heat exchanger to extract heat from the first portion of the exhaust gas, the recycled exhaust gas comprising the second portion of the exhaust gas.