(4) CH3 (methane) + (7) O2 (from air) ---> (6) H2O + (4) CO2 {in a perfect world where you don't get a partial reaction resulting in CO formation.
{This gives 14 electrons...one for each O2- atom transferring through the membrane}
If CO2 counts as "an emission"...you aint getting 'clean' from here.
If CO2 doesn't count...as it doesn't for current automotive...then yes...clean...only giving off CO2, and who cares about that, right?
...except that we aren't in a perfect world, so there will be some CO...
Pure H2 would be better (cleaner) but is extremely energy intensive to make pure. (read $$$)
Hmmm, what if I could drive a clean car... I would nickname it "Hindenburg".
Can't wait to see the fallout from the first collisions...these SOFC's run at 700-800C. Flying bits of 800C rocks (ceramics) peppering bystanders...sounds like a party.
Oh, wait, we pumped a ton (multiple actually) of formaldehyde, MEK and Xylenes into the air making these clean things.
Aint no free lunch. The car itself may be Zero EV...but the life-cycle through manufacturing will never be.
Oh, wait...the anode of the fuel cell is completely loaded with Ni and NiO for internal reformation, thems carcinogens.
Each player in the game gets a part of the process to be responsible for...the car itself can be zero emission after manufacturing, which would be an improvement over current, but the start to finish from raw materials and energy generation through end of life cannot be.