Term
| ASTM distillation temperatures of light gas oil (at 95%vol) and heavy gas oil (at 5%vol) obtained in an atmospheric distillation column are 585°F (i.e.,95% vol of LGO distilled) and 580°F(i.e., 5%vol HGO distilled), respectively. What is the ASTM gap/overlap? |
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Definition
95% light at 585 F & 5% heavy at 580 F
5 F overlap
(overlap because heavy starts at a temperature lower than where light finishes, so the BP ranges overlap) |
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Term
| A depropanizer column needs 8 theoretical plates for the desired level of separation in the column. If plate efficiency is 80% and reflux correction factor is 2, how many actual plates do you need? |
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Definition
20 actual plates
(theor.)/(eff.)*(ref. corr. factor)
8/0.8*2 = 20 |
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Term
| A refinery produces asphalt as an important product that brings revenue, particularly during the summer. In late fall, this refinery switches operations to produce more fuel oil from VDR for the coming winter months, producing still some asphalt, but in lower quantity. In a few weeks, what change should the refinery make? |
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Definition
| Switch the deasphalting solvent from propane to n-pentane |
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Term
| for a refinery that makes more asphalt in the summer and less in the winter, tell whether the DAO & asphalt is light or heavy in the summer & winter |
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Definition
DAO: heavier in winter, lighter in summer
asphalt: heavier in winter, lighter in summer |
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Term
T/F?
Catalytic dewaxing is actually a conversion process |
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Definition
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Term
T/F?
Solvent dewaxing is a separation process |
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Definition
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Term
T/F?
Dewaxing increases the freezing point of the lubricating base oil product |
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Definition
False
(it decreases the freezing pt) |
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Term
T/F?
Propane dewaxing produces a lubricating oil base with a higher viscosity index than ketone dewaxing |
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Definition
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Term
T/F?
Dewaxing produces slack wax from DAO |
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Definition
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Term
T/F?
Wax contains long-chain iso-paraffins |
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Definition
False
(they are straight-chain alkanes) |
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Term
T/F?
Catalytic dewaxing increases the ratio of n-paraffins/i-paraffins in the lube oil base produced |
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Definition
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Term
T/F?
Hydrogen is added during solvent dewaxing to prevent disproportionation |
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Definition
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Term
T/F?
Catalytic dewaxing relies on molecular sieving by the catalyst support |
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Definition
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Term
T/F?
Sovent dewaxing does not require refrigeration |
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Definition
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Term
T/F?
disproportionation in visbreaking involves formation of coke on the surface of visbreaker coils |
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Definition
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Term
T/F?
disproportionation in visbreaking involves formation of light distillates from VDR |
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Definition
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Term
T/F?
disproportionation in visbreaking involves production of fuel oil with a lower pour point than that of VDR |
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Definition
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Term
T/F?
disproportionation in visbreaking involves breaking of C-C bonds |
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Definition
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Term
| At least two drums are used in the delayed coking process in order to __ |
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Definition
| ensure continuity of VDR flow |
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Term
| The principal upgrading strategy used in coking processes is __ |
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Definition
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Term
T/F?
Fluid coking can process VDR with higher sulfur contents |
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Definition
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Term
T/F?
Fluid coking produces only fuel coke |
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Definition
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Term
T/F?
Fluid coking is used more frequently than delayed coking in the US refineries |
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Definition
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Term
T/F?
Fluid coking is a continuous process |
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Definition
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Term
T/F?
Flexi-coking process is a variation of fluid coking |
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Definition
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