Naked Science Forum

Non Life Sciences => Technology => Topic started by: Eric A. Taylor on 18/11/2010 05:02:54

Title: What would be done with the extra ship fuel? (answer)
Post by: Eric A. Taylor on 18/11/2010 05:02:54
I happen to know the answer to this question asked on the podcast. My Father worked at an oil refinery for 30 years before he retired. Ship fuel is called "bunker" fuel and as far as quality it is the lowest quality burnable fuel. If ships around the world stopped using it or used a lot less the oil refineries would do what they do. They would re-refine it to get more usable fuel out of it.

The very basic way a refinery works is they put crude oil (or any type of oil) into a unit called a hydro-cracker. This takes the very long chains of hydrocarbons in crude oil and breaks them up. Inside the cracking unit are shelves that separate these broken chains out. The lightest fuels like LPG and butane are collected at the top, heaver fuels like gasoline (petrol) and diesel are collected lower down, even lower than that is where bunker fuel is collected. Below THAT is unusable fuel stuff and byproducts like surfer and carbon. The nearly pure carbon, called coke, is highly useful in industry, especially in making steel. Steel in the US is made from coke collected from coal as that gives you coke with less sulfur. Sulfur makes the steel of poor quality so a lot of the coke from refineries is sold to the Chinese. As a welder I can always tell when the steel has a lot of sulfur because it bubbles.

Sulfur on the other hand is one of the most useful chemical elements. The refinery my dad worked at sold most of it's sulfur to a plant across the bay that made sulfuric acid then sold the acid back to the refinery.

Anything produced in the cracker that can't be used as a fuel or fuel byproduct is simply run through again. Oil refineries are very efficient.
Title: What would be done with the extra ship fuel? (answer)
Post by: CliffordK on 30/11/2010 08:43:13
Yes,


There is a lot of discussion of cracking fuels, and oils. 


I have heard a type of hydrocracking is the primary way of refining Canadian Bitumen which I believe lies somewhere between tar and coal.  The ships might even have troubles running off of it.