Lecture 1 Flashcards
endothermic
exothermic
uphill energy, unfavorable reaction, energy balance >0
downhill energy, favorable reaction, energy balance < 0
one food caloire
one kcal
4.18 kJ
energy in petroleum
potential energy (fuel molecules) - kinetic energy- mechanical energy - electrical energy losses occur at each step
potential energy
stored in the bonds of molecules
world energy consumption
us consumes about 1/3 of world total of energy
canada is highest consumer of energy per capita on planet - cold and large SA
petroleum
more concentrated source of energy
40-60% more energy per gram than coal
canada is a net exporter
gasoline
light gas oil
heavy gas oil
PETROLEUM FRACTIONS AND CRACKING
70-180C, C6-C10 alkanes
230-305C C13-C17 alkanes (diesel and furnace fuel)
305-405C C18-C25 alkanes (lube oil)
catalytic cracking
at high temp and pressure over a catalyst (zeolite) breaks long chains down to shorter ones via radicals and/or alkyl cations
fractions of petroleum
gas - 19.6 gal diesel and home heating oil - 10 gal jet fuel 4 gal heavy fuel oil 1.7 gal liquified refinery gas 1.7 gal other 7.6 gal
natural gas contents
87-96% methane and 2-6% ethane/other
reforming
for optimal power output, we need smooth combustion at the very top of the piston stoke
when spark plug fires
-rearrange the carbon backbone into more branched hydrocarbons
knocking
caused by multiple ignition parts or pre–ignition and it depends on the structure of hydrocarbon fuel
n-heptane
C7H16
octane number = 0
isooctane
considered standard and all others are rated against a blend of the two
2,2,4 trimethylpentane
gasoline anti-knock agents
tetraethyllead - raises octane ratings
pb-C bond is weak and break readily providing many ethyl radicals that enhance combustion
Pb is highly toxic and is fat soluble
phased out cause killed catalytic converters
