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FSC 432 lecture set 1
questions on lectures up to quiz 1 (Aug 28 to Sep 18) not done yet
102
Chemical Engineering
Undergraduate 4
10/08/2012

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Term
as the number of carbons in an alkane increases, boiling point ___ and density ___
Definition
increases
increases
(high # C = high b.p. and high density
Term
the boiling point of n-alkanes is ___ than the b.p. of iso-alkanes with the same number of carbons
Definition
higher
Term
the principal reason for the molecular complexity of petroleum is ___
Definition
isomers
Term
the octane # of iso-alkanes is ___ than the octane # of n-alkanes with the same number of carbons
Definition
higher
Term
saturated cyclic HCs are also called ___ and ___
Definition
cycloparaffins
naphthenes
Term
the b.p. and denisty of cycloalkanes are ___ than that of n-alkanes with the same number of carbons
Definition
higher
Term
the b.p. of cyclohexane is ___ than the b.p. of hexane
Definition
higher
Term
the octane # of n-pentane is ___ than the octane # of iso-pentane
Definition
lower
Term
the b.p. of n-pentane is ___ the b.p. of isopentane
Definition
higher
Term
alkenes are also called ___ and ___
Definition
unsaturated aliphatic HCs
olefins
Term
relatively how much of crude oil is alkenes?
Definition
little to none
Term
why are alkenes not common in crude oil?
Definition
they are not as stable as alkanes, etc. and break down easily in the ground over time
Term
aromatic compounds have ___ octane #'s
Definition
high
Term
why aren't aromatics found in large quantities in gasoline?
Definition
they may have high octane # but they are toxic (carcinogenic)
Term
polyaromatic compounds can ___
Definition
deactivate catalysts via coking rxns
Term
the most common organo-metallic compounds are ___
Definition
polyphorins
Term
polyphorins
Definition
metal atom at the center of a cage-like structure
Term
solvent fractionation
Definition
characterizes sample based on solubility in a given solvent
Term
name common components of crude oil
Definition
gaseous HCs (methane, ethane)
inorganic gases (H2S, CO2)
resins
asphaltenes
elements like S,N,O
heavy metals
Term
petroleum is classified by ___
Definition
composition
(ternary classification by HC types)
Term
in ternary classification by HC types, there are ___ classes
Definition
6
Term
in ternary classification by HC types, the lower the class #, the ___ the price
Definition
higher
(1 is most expensive)
Term
in ternary classification by HC types, the lower the class #, the ___ it is to refine
Definition
easier
(1 is easiest)
Term
what is the equation for the characterization factor?
Definition
K_Watsom or K_UOP = (T_b)^(1/3)/(SG_15*C)
Term
what is the difference between K_Watson and K_UOP?
Definition
K_Watson uses mean average b.p.
K_UOP uses volume average b.p.
Term
are K_W and K_UOP ever the same?
Definition
yes, for a pure compound they are the same
Term
give some typical K_Watson values
Definition
paraffinic K_W = 11 or 12
naphthelinic K_W = 10 or 11
aromatic K_W < 10
Term
equation for *API gravity
Definition
*API = 141.5/SG_60*F - 131.5
Term
as *API increases, SG ___
Definition
decreases
(high *API = low SG)
Term
pour point
Definition
temp at which oil ceases/starts to flow
Term
pour point relates to the ___ of the oil
Definition
waxiness
Term
as pour point increases, the n-paraffin content ___
Definition
increases
(high PP = high n-parffins)
Term
flash point
Definition
temp above which the oil will spontaneously ignite
Term
real vapor pressure is usually a littl e bit ___ than Reid vapor pressure
Definition
higher
Term
name the 4 important physical properties of crude oil
Definition
viscosity
pour point
flash point
vapor pressure
Term
carbon residue
Definition
solid residue (measure in wt %) remaining after heating to coking temps
Term
what are the two tests for carbon residue?
Definition
Ramsbottom carbon test
Conradson carbon test
Term
as Conradson carbon residue increases, asphaltene content ___
Definition
increases
(high CR = high asphaltene content)
Term
why is knowing salt content important?
Definition
must keep NaCl content under 10 lbs/1000 bbl or there will be corrosion
Term
why is knowing metal content important?
Definition
heavy metals can deactivate catalysts
V at significant concentration can cause corrosion
Term
why is knowing sediment and water content important?
Definition
inorganic particles lead to operational problems
Term
how can acidity be fixed?
Definition
titration with KOH
Term
what is a sweet/sour crude?
Definition
sweet crude: S<0.5 wt%
sour crude: S>0.5 wt%
Term
what is true boiling point distillation?
Definition
distillation fractions are named as light gasoline, heavy naphtha, kerosene, etc. according to the temperature ranges that each fraction comes from. The ranges and names are specified (use a table)
Term
gasoline is rated by ___ and diesel by ___
Definition
octane #
cetane #
Term
octane #
Definition
resistance to ignition by compression
Term
cetane #
Definition
ease of ignition under compression
Term
what is the octane # of octane?
Definition
-10
Term
what is the octane # of 2,2,4-trimethylpentane? ("iso-octane")
Definition
100
Term
engine knock
Definition
spontaneous iginition of fuel
Term
why do we want high octane gasoline?
Definition
because as octane # increases, knock decreases
Term
gasoline engines use
Definition
spark ignition
Term
diesel engines use
Definition
compression ignition
Term
equation for octane #
Definition
octane # = (R + M)/2

R-research octane
M-motor octane
Term
how is octane # measured?
Definition
by comparing the performance of the gasoline to a binary mixture of n-heptane and iso-octane
Term
what is the ocatne number of gasoline distilled straight from crude?
Definition
~40
Term
how to control octane #?
Definition
with additives, like tetraethyl lead (not allowed anymore) and oxygenates
Term
name the main products of a refinery
Definition
gasoline
coke
jet fuel + diesel
LPG
asphalt
fuel oil
Term
what are the 4 process categories for a refinery?
Definition
separation
finishing
conversion
support
Term
briefly desribe desalting
Definition
crude oil and H2O enter the desalter, and desalted crude oil and salt water (waste) come out
Term
what are the first two processes crude oil goes through at a refinery?
Definition
first desalting
then distillation
Term
briefly describe distillation
Definition
desalted crude enters the ditillation column and is fractionated.
lightest fraction is full-range naphtha, heaviest fraction is atmospheric residue, which goes to the vac. distillation unit.
the vac. dist. unit produces vac. gas oil and vacuum residue
Term
briefly describe what happens in the light ends unit
Definition
full range naphtha goes through debutanizer, and C4 and lighter comes out the top and debutanized naphtha out the bottom.
the C4 & lighter goes thru depropanizer, then deethanizer.
The debutanized naphtha goes through a naphtha fractionator and C5 & C6 (to gasoline pool) come out the top and heavy naphtha comes out the bottom (to gasoline pool after being hydrotreated and reformed)
Term
briefly describe what happens in hydrotreating and reforming of heavy naphtha
Definition
heavy naphtha and H2 go into the hydrotreater and H2S and hydrotreated heavy naphtha comes out.
hydrotreated heavy naphtha has H removed in the catalytic reformer and reformate and H2 comes out.
Term
how is the octane # increased in catalytic reforming?
Definition
cycloparaffins -> aromatics
n-alkanes -> i-alkanes
Term
what does the catalytic reformer use as a catalyst?
Definition
Pt
Term
thru hydrotreatment, kerosene can be converted to ___ and light gas oil can be converted to ___
Definition
jet fuel (C10 to C15)
diesel fuel (C15 to C20)
Term
what processes can heavy gas oil be sent to and what are the products of each?
Definition
visbreaking -> fuel oil
thermal cracking -> LPG, naphtha, kerosene, light gas oil
catalytic cracking -> ethane, LPG, gasoline, slurry oil
Term
briefly describe what happens in fluid catalytic cracking of heavy gas oil
Definition
heavy gas oil goes in, is cracked using a catalyst, and branched alkanes are produced.
the products are ethane, LPG, gasoline, and slurry oil
Term
what can be done with slurry oil?
Definition
after decanting, it can be used as fuel oil or coked to produce needle coke
Term
what is needle coke used for?
Definition
graphite electrodes
Term
briefly describe what happens in hydrocracking of light vacuum gas oil (C25 to C35)
Definition
light vacuum gas oil and H2 go in, the LVGO is cracked using a catalyst, and C3, C4, and light & middle distillates come out
Term
why is H2 fed into the hydrocracking unit?
Definition
to saturate the unpaired electrons on carbons after the carbon chains are cracked
Term
briefly describe what happens in solvent extraction
Definition
heavy vacuum gas oil goes in and heavy aromatics are extracted
after long chain n-paraffins are removed (dewaxing), lube oil base stock is produced
Term
HVGO stands for ___
Definition
heavy vacuum gas oil
Term
FCC stands for ___
Definition
fluid catalytic cracking
Term
briefly describe what happens in deasphalting
Definition
vacuum residue goes in, and aftre propane deasphalting, deaphalted oil and asphalt come out
after hydrotreating, the DAO is fuel oil
Term
DAO stands for ___
Definition
deasphalted oil
Term
define asphaltenes
Definition
compounds not soluble in normal alkanes and soluble in aromatics
Term
define maltenes
Definition
compounds soluble in n-pentane
types: resins and oils
Term
define resins
Definition
compounds soluble in n-pentanes and soluble in propane
Term
define oils
Definition
compounds soluble in n-pentanes and NOT soluble in propane
Term
VDR stands for ___
Definition
vacuum distillation residue
Term
what are the alternatives to vacuum residue treatment?
Definition
visbreaking
coking
Term
briefly describe what happens in visbreaking of VDR
Definition
VDR goes in, mild thermal cracking occurs, and C3 & C4, naphtha, middle distillates, fuel oil, and coke are produced
Term
in visbreaking, how much coke is produced, and where does it collect?
Definition
a very small amount
on the reactor walls
Term
briefly describe what happens in coking of VDR
Definition
VDR goes in, sever thermal cracking occurs, and light & middle distillates and sponge coke & fuel grade coke are produced
Term
what can be done with sponge coke?
Definition
it can be turned into anode coke (used in manufacturing)
Term
what are the two major paths for upgrading heavy oil?
Definition
carbon rejection
hydrogen addition
Term
what are the processes that can be used in carbon rejection for upgrading heavy oil?
Definition
coking
solvent extraction
visbreaking
catalytic cracking
Term
what are the processes that can be used in hydrogen addition for upgrading heavy oil?
Definition
hydrocracking
hydrogenation
Term
name three distillation methods
Definition
TBP
ASTM
EFV
Term
TBP stands for __
Definition
true boiling point
Term
ASTM stands for __
Definition
American Society for Testing and Materials
Term
EFV stands for __
Definition
equilibrium flash vaporization
Term
put the three distillation methods in order of decreasing degree of separation
Definition
TBP (most separation)
ASTM
EFV (least separation)
Term
what does a schematic of TBP distillation look like?
Definition
[image]
Term
what does a schematic of ASTM distillation look like?
Definition
[image]
Term
what does a schematic of EFV distillation look like?
Definition
[image]
Term
describe TBP distillation
Definition
uses a large numbver of plates and a large reflux ratio to distill almost pure components
Term
define reflux
Definition
reflux is liquid that is distilled by a distillation column; it is undesired and often returned to the column, hence the name
Term
define reflux ratio (RR)
Definition
ratio of liquid ("reflux") to distillate produced by a distillation column
RR = reflux/distillate = R/P
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