Well, GE and Umicore have announced they've signed a Technology License agreement to commercialize a hydrocarbon selective lean NOx catalyst (HC-LNC) aftertreatment designed to control diesel NOx emissions that doesn't use urea. The catalyst is being designed for off-highway and on-road vehicles, marine applications and even stationary power markets (i.e. generators).
GE's lean NOx catalyst system, also referred to as hydrocarbon selective catalytic reduction (HC-SCR), can use diesel fuel or E85 as the reductant instead of urea. The system is being developed as presumably a lower-cost and more readily available alternative to the urea-based SCR technology used by Mercedes-Benz, Volkswagen and others to meet stringent Tier 2 Bin 5 emission standards. In those systems, urea is stored in liquid form in a tank on-board the vehicle and slowly injected into the exhaust stream where it forms ammonia that reacts with the NOx and converts it to water and nitrogen.
Though Mercedes' urea solution – AdBlue – was originally said to cost around $4 a gallon to replenish, we've heard it costs around $32 a gallon plus labor to have the AdBlue topped off by the dealer. Details are pretty slim, but If GE's catalyst system really does scrub diesel emissions using petroleum diesel or E85, that $4 a gallon mark might once again be a reality.