Re: What is distillate?

Posted by big fred on September 01, 1999 at 20:38:07 from (199.238.169.113):

In Reply to: What is distillate? posted by Rich on September 01, 1999 at 19:47:07:

Let's see if I can remember the mini-lecture we got on this awhile back. I think the fellow that gave us this mini-lecture was Steamer, who I haven't seen post for quite some time.

Petroleum used to be refined by distillation, using a tall tower called a fractionating tower. The lighter compounds would be taken off the top, like gasoline, while the heavier compounds were taken off down lower, like kerosene and diesel fuel. Turns out there was a large amount of stuff left in the middle that they called distillate, kind of a undesireable fuel for many uses. Tractors could be made to run on it, however, if the engine was preheated by running on more expensive gasoline. Since it was not a very desireable fuel, it was cheap.
When WWII came along, the need for gasoline surged due to the war effort and the development of high-performance aircraft engines. The demand for gas couldn't be met by the distillation process, so a new process, called catalytic cracking was invented, in which the heavier stuff that would have been destined to become diesel and distillate (among others) could be chemically changed by means of a catalyst to become gasoline. This meant that the refineries no longer had a bunch of distillate left over, and the price of gasoline came down due to greater supply, so distillate and its bad properties went away, and distillate engines were converted to run on gasoline full time.

So, you petroleum experts out there, am I close to being correct? I took notes last time. :o)

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