Transcript petroleum
In order to be a member of a flock of sheep, one must above
all be a sheep oneself.
-- Albert Einstein
MOST OF THE COMPOUNDS THAT MAKE UP
FOSSIL FUELS ARE HYDROCARBONS - THAT IS,
THEY CONTAIN MOSTLY CARBON AND
HYDROGEN.
CARBON IS A UNIQUE ATOM IN THAT IT CAN
BOND TO ITSELF TO FORM MILLIONS OF
COMPOUNDS.
THE COMPOUNDS THAT MAKE UP FOSSIL FUELS
WOULD BE OF THE TYPE:
ELEMENTAL COMPOSITION OF
CRUDE OIL
COMPONENT
Carbon
Sulfur
Oxygen
Hydrogen
Nitrogen
Metals
Wt%
83-87%
0-3%
0-0.5%
11-14%
0-1%
0-0.2%
PETROLEUM WAS FORMED WHEN LARGE
QUANTITIES OF PLANKTON AND ALGAE
WERE BURIED BENEATH SEDIMENT AND
EVENTUALLY SUBJECTED TO ENOUGH HEAT
AND PRESSURE TO BE CONVERTED TO
PETROLEUM.
THERE IS A MINIMUM AND A MAXIMUM
TEMPERATURE FOR THIS PROCESS. IF THE
TEMPERATURE IS TOO LOW, THE MATERIAL
REMAINS AS KEROGEN (WAXY LIKE
MATERIAL). IF THE TEMPERATURE IS TOO
HIGH, THE PETROLEUM IS CRACKED TO
NATURAL GAS.
CRUDE OIL COMPOSITION
Fraction
Gases
Gasoline
Kerosine
Diesel
Gas oil
Atmospheric
Resid
No. Carbons
1 to 4
5-10
10-15
13-18
16-25
>25
Boiling Range
<0o C
25-80o C
80-145o C
96-160o C
160-340oC
>3400 C
%
2%
34%
11%
21%
20%
12%
CRUDE OIL TYPES
PARAFFIN BASE CRUDE WAX IS PRIMARY RESIDUE
ASPHALT BASE CRUDE ASPHALT IS PRIMARY
RESIDUE
MIXED BASE CRUDE - SOME
OF BOTH
A REFINERY AT NIGHT
THE MAIN REFINERY PROCESS IS
DISTILLATION, WHICH SEPARATES THE
FRACTIONS BY BOILING POINT.
ATMOSPHERIC DISTILLATION CAN SEPARATE
MATERIALS THAT HAVE BOILING POINTS UP
TO ABOUT 800o F.
IF MATERIALS HAVE HIGHER BOILING POINTS,
VACUUM DISTILLATION WOULD HAVE TO BE
USED.
https://www.youtube.com/watch?v=jk0WrtA8_T8
AN ATMOSPHERIC DISTILLATION COLUMN WOULD
SEPARATE MATERIALS THAT BOILED UP TO
ABOUT 800O F.
ABOVE THAT TEMPERATURE, MOLECULES
WOULD START TO DECOMPOSE (CRACK).
ANY MATERIAL LEFT THAT DID NOT DISTILL
(ATMOSPHERIC RESID) WOULD BE TAKEN TO A
VACUUM STILL FOR FURTHER DISTILLATION.
THE MATERIAL THAT WOULD DISTILL HERE
WOULD BE THE LUBRICANT BASE OIL STOCKS.
STAR REFINERY, THAILAND
THERE ARE A NUMBER OF PROCESSES IN A
REFINERY THAT ARE USED TO CONVERT
HEAVIER MOLECULES TO GASOLINE RANGE
MATERIAL.
THERE ARE ALSO PROCESSES TO CONVERT
STRAIGHT CHAIN HYDROCARBONS TO
BRANCHED CHAIN HYDROCARBONS. THIS
INCREASES THE OCTANE RATING OF THE
GASOLINE.
OCTANE RATING IS IMPORTANT FOR ELEMINATING
ENGINE KNOCK.
MOST CARS HAVE AROUND AN 8.5 TO 1
COMPRESSION RATIO.
THE COMPRESSION RATIO IS THE VOLUME OF
THE CYLINDER WITH THE PISTON DOWN TO THE
VOLUME WITH THE PISTON UP.
THE OCTANE RATING NEEDED DEPENDS ON THE
COMPRESSION RATIO OF THE ENGINE.
N-HEPTANE IS GIVEN AN OCTANE RATING OF 0.
ISOOCTANE IS GIVEN AN OCTANE RATING OF
100.
A DIESEL ENGINE DOES NOT USE A SPARK PLUG,
BUT DEPENDS ON COMPRESSION TO IGNITE THE
FUEL.
DIESEL FUEL IS HEAVIER AND CONTAINS ABOUT
20% TO 30% MORE ENERGY THAN GASOLINE.
DIESEL FUEL IS RATED
ON A CETANE SCALE.
CETANE IS USED FOR
100.
MOST DIESEL ENGINES
WILL RUN IF THE CN IS
45 OR ABOVE.
BIODIESEL IS USUALLY
56 TO 60.
DIESEL ENGINES HAVE COMPRESSION RATIOS OF
FROM 14:1 TO 25:1.
MOST AUTOMOBILE ENGINES HAVE COMPRESSION
RATIONS OF AROUND 8.5:1.