There was serious competition in the trans-Atlantic route (mainly New York to London,) and steam engines and diesel engines were competing. Steam engines had a low efficiency, around 18 percent, but steam boilers could use heavy fuels. Diesel engines had higher efficiency (24 to 26 percent) but used distillate diesel fuels.
These fuels were more expensive than heavy fuel even after considering the higher efficiency of diesel engines. Charles Lamb boldly introduced heavy fuels. The heavy fuels of those days had not undergone secondary refining processes such as cat cracking, vis breaking, thermal cracking etc. They had enough lighter fractions, and they burned in the diesel engines without too much trouble.
Progressively, the industry extracted greater amount of lighter fractions from the heavy fuel, leaving behind only residual fuels. These residual fuels carried all the impurities and elements and consequent problems. However, the industry learned to cope with the problems. The industry introduced purifiers, clarifiers, settling tanks, filters, all of which rendered the residual fuel usable in the diesel engines. At the same time, diesel engines were redesigned with long stroke, slow speed etc. enabling the usage of the difficult residual fuels.
There is no disagreement now that, by and large, we have learned to use the residual fuels, and the one and only problem is the high sulfur content. Here too, the scrubbers take care of the high sulfur and ensure compliance with regulations.
So, the question that we should ask is, why make a change when we have solved all the problems? The need for change has not been forced due to any disruptive technology. We still have the same old residual fuel, and we are only trying to replace it with the same old distillate fuel. Why pay $200 per metric ton more for a problem that has already been solved?
The situation is analogous to “My Fair Lady” where Professor Higgins picked up Eliza Dolittle, tidied her, made her presentable and acceptable to the high society. Why now try to throw her back into the slums? What is wrong with the newly made up Eliza Dolittle? She serves the purpose.
This is not all. What are we going to do with 300 million metric tons of fuel? How much of it can be converted into coke? What are we going to do with the rest? Why are we creating a problem and trying to solve it?
I say, introduce the scrubber and continue the business as usual. There is no better solution.