[thackney]

It’s the mother’s milk of the refining process.

- - - - - - - -

Also known as “refinery leftovers” and “the bottom of the barrel”.

Lots of BTU’s however in those long-chain hydrocarbons.

Cheers

[Eric in the Ozarks]

As refineries work harder to get as much out of a bbl of crude as possible, the residual oil, in many cases, has become more condensed.

Negative gravities—some as heavy as -6 API, are becoming commonplace. Some BTU gallons are measured as 165,000 per gallon.