Thread: Basic Petrodiesel Questions

Why does thick black smoke come out of an exhaust pipe when a diesel powered vehicle starts or has to labour up a steep hill?

What does "low quality" diesel actually mean (what is it low or high in exactly) and why or how would it be produced?

if anybody has a link to websites explaining to the ignorant (of which I am a paid up member) of how diesel fuels are obtained and processed, I would be very grateful.

Thanks in advance.

wfg

Fuels and Petrol products are obtained from crude oil by a fractional distillation process, and then cracking is used to obtain the shorter chain hydrocarbons.

I'd imagine that the quality of the diesel refers to the percentage of impurities in the diesel product.
Low quality diesel could be useful when these impurities are not an issue and further purification would be expensive.

The thick black smoke i think is due to incomplete combustion, but i could be wrong

Diesel is one of the middle distillates, which are the products that come out of the middle section of a distillation column. Diesel can also be produced synthetically from syngas using the Fischer Tropsch process.

Low and high quality probably refer to the cetane number of the fuel which is a measure of its chemical composition and hence its combustion characteristics compared to pure cetane, which is C16H34.