I expect future cargo ships will be coal fired with some form of plant oil/animal fat/ocky goop that burns used when near shore.

But I dont expect that to be needed for a few more deaces as heavy oil and oil sands both likely result in even more percentage of icky burnable goop. aka bunker oil.

Andrey the Pedant,
non-biological systems are often referred to colloquially as healthy or sick or crook, and many would argue that our planet as a whole is much more than a non- biological system.
And since we're geting picky, just because pollution is emitted mid-ocean doesn't mean it is harmless!

Aussie, to be pedant to the end:

Reference to the Earth as being living creature is a)meaningless b)too many folks are making fa-a-ar reaching claims on this base, like humankind being “scum of the Earth”

That’s why I do not like it.

Exhaust emissions over the ocean are harmless for only one reason: they got washed down to the ocean quite fast, and compared to amount of same substances in sea water they are just minuscule and do not harm ocean ecosystems. Not the case with oil spills or ballast water discharge, for that matter.

Why not have a duel cycle gas turbine/steam engine(s)? Duel cycle is even more efficient then diesel, and duel cycle using gasification could burn almost anything. The only problem I see is that a duel cycle system would be complex and very expensive.

As for the particle bed reactor, the particles in the reactor would be very difficult to refine nuclear fissionables from (it's been tried before for thorium cycle and failed) and the particles would also be difficult to us in a dirty bomb. So the particle bed reactor (at least on paper) could be much more economical and safer then light water reactors, perhaps even cheap and safe enough to power large ships.

Ben,

I believe your observations are accurate. Rod Adams does not speak to energy density on his web site. The South African pebble bed is low power but has a physically large core. I have not seen anything that says sufficient energy density for a mobile source can be achieved with a pebble bed.

I am not saying it can't be done, I just haven't seen anything that says it can be.

Bill Young,

Well the pebble beds are big (the core is as big as a silo!), that run in a closed Brayton cycle using helium, this is very efficient, but has a much lower power density then even a steam Rankine cycle. So yes I agree I would have to see a study on the feasibility of cramming a pebble bed in a little tiny post-panmax ship (I'm being sarcastic) in short the pebble bed is big, but the ships are bigger!

Guys, I'm really interested in how biofuels can help reduce greenhse gas emissions. Can anyone help me point out the difference between using ethanol and methanol applicatons?

Is there a average output that can be used as a constant to estimate CO2 for freight shipping in association to milage. ie 1000 miles = ?? CO2 I realise this would be only a guideline.

How else could we calculate co2 output for x amount of shipping milage ??

Does anyone have fuel consumption data for cruise ships?

I remember looking at the Transport Task figures for Australia and the mode of ferries/ships was bottom of the ladder. So irrespective of motor or fuel are we not talking about a wasteful form of transport in the first place. I was rather see less shipping because I know we dont need 90% of what is shipped and its damaging local economy and does not make economic sense.

I know there is a role for shipping and cruises but we needs as well to look at what we are doing and whether its a good idea to keep doing it.

Nigel