MarEng
Silver Member
Yes - We are becoming the next target for air pollution legislation. Most is coming on an international basis - Sulfur content has already been mandated down and engine emmission limits are tightening for new ships. Now California and several other states are working towards further reductions - including running on different fuels while in state waters and/or shutting down completely at the dock and plugging into the grid (cold ironing). I'm currently working a project to look at ship safety during fuel changes in restricted waters (vapor lock, thermal shock, flameout, etc.). With a ship design life of 25 years and an actual life closer to 35 years it will take a while for the physical changes (new engines, ability to plug in, etc.) to have a profound effect.
Depite this, shipping is still the most efficient way to move material. What is counter-intuitive is that some of the required changes (esp. related to NOx reductions) lead to lower fuel efficiency. I still can't get my mind around how it is better for the environment to burn more fuel. I guess that's just my old school thermo background. I also wonder how much energy is expended to get more sulfur out of the fuel at the refinery and what impact this has? One of the approved emmissions treatments is to inject water into the uptakes. Seems steaming across the ocean would have the same effect. But I ramble now . . .
Depite this, shipping is still the most efficient way to move material. What is counter-intuitive is that some of the required changes (esp. related to NOx reductions) lead to lower fuel efficiency. I still can't get my mind around how it is better for the environment to burn more fuel. I guess that's just my old school thermo background. I also wonder how much energy is expended to get more sulfur out of the fuel at the refinery and what impact this has? One of the approved emmissions treatments is to inject water into the uptakes. Seems steaming across the ocean would have the same effect. But I ramble now . . .