Are you sure, I was under the impression it is a byproduct of petrol production (it boils-off the cat-cracker before petrol)?

I stand to be corrected BTW, it is a long time since I did my chemistry O level!

My recollection is also from (45 year old) school science. The most volatile fractions go to the top of the cat-cracker before condensing. Petrol will condense further up than diesel. Cannot recall if refining technique or class/origin of crude oil can lead to variations in proportions of different fractions from a barrel of oil.

Cannot see how UK refineries can avoid producing at least some diesel though as it's pretty much same fraction as domestic heating oil there may be some choice as to which market it's sold in. IIRC old fashioned mechanical injection diesels like PSA's XUD would run quite happily on heating oil - at least in the summer when waxing was not a problem.

Wouldn't want to chance it with modern high pressure injection units though.

Edited by Bromptonaut on 06/11/2018 at 18:13

One of the important functions of the cat-cracker is to reshape the C7-C9 molecules (petrol) with some branching, which alters the burn characteristics. That was one way to avoid the need for anti-knock additives. Refineries can be 'tuned' to adjust the balance between petrol and the heavier stuff, when more heating oil is needed in winter.

A quick google comes up with a recent government published document analyzing the market.

It would appear the UK refining process is geared up to produce petrol and heating grade diesel so the UK is a big exporter of petrol and one of the biggest OECD importers of road diesel.

However, to say that there will be no effect on prices because all road diesel is imported must over-simplify the pricing function. The price could even go up as the UK imports smaller volumes and economies of scale kick in.