GC: n

CT: Hydrocracking is an important source of diesel and jet fuel.
A hydrocracking unit, or hydrocracker, takes gas oil, which is heavier and has a higher boiling range than distillate fuel oil, and cracks the heavy molecules into distillate and gasoline in the presence of hydrogen and a catalyst. The hydrocracker upgrades low-quality heavy gas oils from the atmospheric or vacuum distillation tower, the fluid catalytic cracker, and the coking units into high-quality, clean-burning jet fuel, diesel, and gasoline.

S: http://www.eia.gov/todayinenergy/detail.cfm?id=9650 (last access: 20 December 2014)

N: 1. Fromo hydro- (before vowels hydr-, word-forming element meaning “water,” from Greek hydro-, comb. form of hydor “water”) and cracking (“excellent,” colloquial from 1830s, from present participle of verb crack, Old English cracian “make a sharp noise,” from Proto-Germanic krakojan (cognates: Middle Dutch craken, Dutch kraken, German krachen), probably imitative).
First known use of hydrocracking: 1940. The cracking of hydrocarbons in the presence of hydrogen.
To hydrocrack: to break down (a hydrocarbon) by the process of hydrocracking. To convert hydrocarbons by hydrocracking.
2. A refining process for converting middle-boiling or residual material to high-octane gasoline, reformer change stock, jet fuel and/or high-grade fuel oil.
3. Process combining cracking and hydrogenation. (Definition standardized by ISO).
4. hydrocracking: term standardized by ISO.

S: 1. OED – http://www.etymonline.com/index.php?allowed_in_frame=0&search=hydro&searchmode=none (last access: 20 December 2014); MW – http://www.merriam-webster.com/dictionary/hydrocracking (last access: 20 December 2014); https://www.wordnik.com/words/hydrocrack (last access: 20 December 2014). 2, 3 & 4. TERMIUMPLUS.

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CR: [coke ], cracking, natural gas, petroleum.