The usual chemical process involves making succinic acid from crude oil or natural gas.
Canadians make the mistake of burning a premium fuel, natural gas, to endothermically refine heavy crude oil.
As an engineer, he was also aware oil drills suck up natural gas with crude.
Correspondents are right that it has nothing to do with what they learn at university or anything as crude as ability or merit.
Here's a really crude example that may not be helpful at all.
His particular emotions may be simple, or crude, or flat.
But crude prices have surged in the past decade, and the world's largest energy corporations are thirsty for more oil.
Population density is of course a crude indicator of human and economic activity.
Then again, the talented tenth of a tenth could also embrace crude rent-seeking, leaving the economy in ruins.
Nobody was making crude jokes or bragging about the latest run-in with the hood rats.