FSC 432 lecture set 1 – Flashcards
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| as the number of carbons in an alkane increases, boiling point ___ and density ___ |
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| increases increases (high # C = high b.p. and high density |
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| the boiling point of n-alkanes is ___ than the b.p. of iso-alkanes with the same number of carbons |
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| higher |
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| the principal reason for the molecular complexity of petroleum is ___ |
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| isomers |
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| the octane # of iso-alkanes is ___ than the octane # of n-alkanes with the same number of carbons |
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| higher |
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| saturated cyclic HCs are also called ___ and ___ |
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| cycloparaffins naphthenes |
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| the b.p. and denisty of cycloalkanes are ___ than that of n-alkanes with the same number of carbons |
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| higher |
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| the b.p. of cyclohexane is ___ than the b.p. of hexane |
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| higher |
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| the octane # of n-pentane is ___ than the octane # of iso-pentane |
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| lower |
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| the b.p. of n-pentane is ___ the b.p. of isopentane |
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| higher |
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| alkenes are also called ___ and ___ |
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| unsaturated aliphatic HCs olefins |
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| relatively how much of crude oil is alkenes? |
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| little to none |
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| why are alkenes not common in crude oil? |
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| they are not as stable as alkanes, etc. and break down easily in the ground over time |
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| aromatic compounds have ___ octane #'s |
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| high |
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| why aren't aromatics found in large quantities in gasoline? |
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| they may have high octane # but they are toxic (carcinogenic) |
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| polyaromatic compounds can ___ |
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| deactivate catalysts via coking rxns |
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| the most common organo-metallic compounds are ___ |
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| polyphorins |
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| polyphorins |
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| metal atom at the center of a cage-like structure |
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| solvent fractionation |
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| characterizes sample based on solubility in a given solvent |
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| name common components of crude oil |
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| gaseous HCs (methane, ethane) inorganic gases (H2S, CO2) resins asphaltenes elements like S,N,O heavy metals |
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| petroleum is classified by ___ |
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| composition (ternary classification by HC types) |
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| in ternary classification by HC types, there are ___ classes |
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| 6 |
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| in ternary classification by HC types, the lower the class #, the ___ the price |
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| higher (1 is most expensive) |
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| in ternary classification by HC types, the lower the class #, the ___ it is to refine |
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| easier (1 is easiest) |
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| what is the equation for the characterization factor? |
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| K_Watsom or K_UOP = (T_b)^(1/3)/(SG_15*C) |
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| what is the difference between K_Watson and K_UOP? |
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| K_Watson uses mean average b.p. K_UOP uses volume average b.p. |
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| are K_W and K_UOP ever the same? |
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| yes, for a pure compound they are the same |
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| give some typical K_Watson values |
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| paraffinic K_W = 11 or 12 naphthelinic K_W = 10 or 11 aromatic K_W < 10 |
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| equation for *API gravity |
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| *API = 141.5/SG_60*F - 131.5 |
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| as *API increases, SG ___ |
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| decreases (high *API = low SG) |
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| pour point |
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| temp at which oil ceases/starts to flow |
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| pour point relates to the ___ of the oil |
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| waxiness |
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| as pour point increases, the n-paraffin content ___ |
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| increases (high PP = high n-parffins) |
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| flash point |
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| temp above which the oil will spontaneously ignite |
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| real vapor pressure is usually a littl e bit ___ than Reid vapor pressure |
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| higher |
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| name the 4 important physical properties of crude oil |
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| viscosity pour point flash point vapor pressure |
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| carbon residue |
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| solid residue (measure in wt %) remaining after heating to coking temps |
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| what are the two tests for carbon residue? |
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| Ramsbottom carbon test Conradson carbon test |
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| as Conradson carbon residue increases, asphaltene content ___ |
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| increases (high CR = high asphaltene content) |
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| why is knowing salt content important? |
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| must keep NaCl content under 10 lbs/1000 bbl or there will be corrosion |
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| why is knowing metal content important? |
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| heavy metals can deactivate catalysts V at significant concentration can cause corrosion |
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| why is knowing sediment and water content important? |
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| inorganic particles lead to operational problems |
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| how can acidity be fixed? |
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| titration with KOH |
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| what is a sweet/sour crude? |
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| sweet crude: S<0.5 wt% sour crude: S>0.5 wt% |
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| what is true boiling point distillation? |
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| 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) |
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| gasoline is rated by ___ and diesel by ___ |
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| octane # cetane # |
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| octane # |
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| resistance to ignition by compression |
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| cetane # |
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| ease of ignition under compression |
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| what is the octane # of octane? |
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| -10 |
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| what is the octane # of 2,2,4-trimethylpentane? ("iso-octane") |
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| 100 |
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| engine knock |
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| spontaneous iginition of fuel |
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| why do we want high octane gasoline? |
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| because as octane # increases, knock decreases |
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| gasoline engines use |
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| spark ignition |
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| diesel engines use |
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| compression ignition |
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| equation for octane # |
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| octane # = (R + M)/2 R-research octane M-motor octane |
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| how is octane # measured? |
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| by comparing the performance of the gasoline to a binary mixture of n-heptane and iso-octane |
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| what is the ocatne number of gasoline distilled straight from crude? |
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| ~40 |
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| how to control octane #? |
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| with additives, like tetraethyl lead (not allowed anymore) and oxygenates |
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| name the main products of a refinery |
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| gasoline coke jet fuel + diesel LPG asphalt fuel oil |
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| what are the 4 process categories for a refinery? |
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| separation finishing conversion support |
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| briefly desribe desalting |
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| crude oil and H2O enter the desalter, and desalted crude oil and salt water (waste) come out |
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| what are the first two processes crude oil goes through at a refinery? |
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| first desalting then distillation |
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| briefly describe distillation |
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| 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 |
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| briefly describe what happens in the light ends unit |
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| 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) |
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| briefly describe what happens in hydrotreating and reforming of heavy naphtha |
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| 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. |
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| how is the octane # increased in catalytic reforming? |
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| cycloparaffins -> aromatics n-alkanes -> i-alkanes |
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| what does the catalytic reformer use as a catalyst? |
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| Pt |
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| thru hydrotreatment, kerosene can be converted to ___ and light gas oil can be converted to ___ |
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| jet fuel (C10 to C15) diesel fuel (C15 to C20) |
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| what processes can heavy gas oil be sent to and what are the products of each? |
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| visbreaking -> fuel oil thermal cracking -> LPG, naphtha, kerosene, light gas oil catalytic cracking -> ethane, LPG, gasoline, slurry oil |
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| briefly describe what happens in fluid catalytic cracking of heavy gas oil |
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| heavy gas oil goes in, is cracked using a catalyst, and branched alkanes are produced. the products are ethane, LPG, gasoline, and slurry oil |
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| what can be done with slurry oil? |
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| after decanting, it can be used as fuel oil or coked to produce needle coke |
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| what is needle coke used for? |
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| graphite electrodes |
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| briefly describe what happens in hydrocracking of light vacuum gas oil (C25 to C35) |
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| light vacuum gas oil and H2 go in, the LVGO is cracked using a catalyst, and C3, C4, and light & middle distillates come out |
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| why is H2 fed into the hydrocracking unit? |
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| to saturate the unpaired electrons on carbons after the carbon chains are cracked |
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| briefly describe what happens in solvent extraction |
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| 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 |
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| HVGO stands for ___ |
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| heavy vacuum gas oil |
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| FCC stands for ___ |
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| fluid catalytic cracking |
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| briefly describe what happens in deasphalting |
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| vacuum residue goes in, and aftre propane deasphalting, deaphalted oil and asphalt come out after hydrotreating, the DAO is fuel oil |
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| DAO stands for ___ |
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| deasphalted oil |
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| define asphaltenes |
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| compounds not soluble in normal alkanes and soluble in aromatics |
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| define maltenes |
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| compounds soluble in n-pentane types: resins and oils |
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| define resins |
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| compounds soluble in n-pentanes and soluble in propane |
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| define oils |
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| compounds soluble in n-pentanes and NOT soluble in propane |
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| VDR stands for ___ |
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| vacuum distillation residue |
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| what are the alternatives to vacuum residue treatment? |
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| visbreaking coking |
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| briefly describe what happens in visbreaking of VDR |
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| VDR goes in, mild thermal cracking occurs, and C3 & C4, naphtha, middle distillates, fuel oil, and coke are produced |
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| in visbreaking, how much coke is produced, and where does it collect? |
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| a very small amount on the reactor walls |
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| briefly describe what happens in coking of VDR |
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| VDR goes in, sever thermal cracking occurs, and light & middle distillates and sponge coke & fuel grade coke are produced |
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| what can be done with sponge coke? |
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| it can be turned into anode coke (used in manufacturing) |
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| what are the two major paths for upgrading heavy oil? |
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| carbon rejection hydrogen addition |
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| what are the processes that can be used in carbon rejection for upgrading heavy oil? |
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| coking solvent extraction visbreaking catalytic cracking |
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| what are the processes that can be used in hydrogen addition for upgrading heavy oil? |
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| hydrocracking hydrogenation |
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| name three distillation methods |
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| TBP ASTM EFV |
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| TBP stands for __ |
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| true boiling point |
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| ASTM stands for __ |
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| American Society for Testing and Materials |
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| EFV stands for __ |
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| equilibrium flash vaporization |
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| put the three distillation methods in order of decreasing degree of separation |
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| TBP (most separation) ASTM EFV (least separation) |
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| what does a schematic of TBP distillation look like? |
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| [image] |
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| what does a schematic of ASTM distillation look like? |
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| [image] |
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| what does a schematic of EFV distillation look like? |
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| [image] |
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| describe TBP distillation |
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| uses a large numbver of plates and a large reflux ratio to distill almost pure components |
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| define reflux |
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| reflux is liquid that is distilled by a distillation column; it is undesired and often returned to the column, hence the name |
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| define reflux ratio (RR) |
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| ratio of liquid ("reflux") to distillate produced by a distillation column RR = reflux/distillate = R/P |
