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43 Cards in this Set
- Front
- Back
What are the two approaches to acid-gas treating?
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absorption and chemical reaction
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What is the difference between primary, secondary, and tertiary amines?
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# of R groups
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What are two advantages of DEA as compared to MEA?
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low vap pressure, fewer irreversible products w/h2s
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What is a disadvantage of DEA as compared to MEA?
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more irreversible w/CO2, may require vacuum distillation
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Why might a water wash be added to the top of an MEA absorber?
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recover MEA
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What is the primary difference of the Split Flow and Basic flow sheets?
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only part of streamis stripped to be highly lean
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What are four design approaches that we have mentioned for amine acidgas
treating |
rule of thumb, approch to equilibrium, equilibrium, rate-based
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What is the most widely used computer program for acid-gas
calculations |
tsweet or promax
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What kind of trays do most modern gas sweetening plants use?
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sieve
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When is packing used in modern plants?
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revamps and special applications
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When trayed columns are used, approximately how many are
there? |
20
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What are typical HETP’s for the absorber and stripper?
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absorber 10-12ft stripper 2-3ft
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What are the dual purposes of the absorber?
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heat exchanger
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What is the temperature bulge in an absorber?
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due to exothermic reaction
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How many grains are there in a pound?
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7000
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How does a Claus plant of today differ from an original design?
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Reactor split in 2 combustor & catalytic
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What are the temperature ranges for high conversion?
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T<700 T>1800
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Which of these ranges is preferred and why?
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T>1800 runs faster
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What are the primary types of the Claus process?
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straight through, split flow, sulfur recycle, direct oxidation
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What pressure of steam is produced by the furnace boiler?
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150-500
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What pressure of steam is produced by the catalytic condensers?
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50-70
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What are the major side products produce by the Claus plant?
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CO, COS, CS2
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Why does the liquid sulfur need to be treated?
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As liquid cools, polysulfides change to H2S and is emitted
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In the Shell degasification process, where is the stripper located?
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in the sulfur pit
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In the Texasgulf degasification process, where is the stripper
located and how much gas is fed? |
stripper is above the sulfur pit and no gas is fed
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For the SNEA[P] process what is the major disadvantage?
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sulfur may be contaminated by the catalyst
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What is the primary usage of oxygen-based sulfur plants and why?
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debottlenecking since the total gas is significantly reduced
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For moderate-level oxygen-based sulfur plants, what is the
consistent attribute? |
tip- mixing burners for gas and O2
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Why consider isothermal converters for sulfur plants?
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obtain almost the same performance as adibatic with less equipment
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What is the typical recovery of sulfur in a Claus unit?
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97%
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What are three processes that use catalytic reaction to extend the Claus
process? |
sulfreen, CBA, MCRC
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How many converters are typically in large plants using the following
processes: Sulfreen, CBA, MCRC? |
sulfreen 3; cma4; cmrc3
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What do the abbreviations CBA, MCRC, BSR, MODOP, SCOT represent?
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coal bed adsorption, maximum claus recovery concept, beavon sulfur removal, mobil oil direct oxidation process, shell claus off-gas treating
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When does the highly exothermic direct oxidation work?
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when concentration of H2S is small
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What do Superclaus, BSR, SCOT, Selectrox, and MODOP processes have
in common? |
They all convers sulfur compounds to H2S and then to elemental sulfur
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What type catalyst do the BSR and SCOT process for TGCU use?
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BSR cobalt molybendate, scot cobalt molybdenum
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At what pressure is LNG typically stored?
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1 atm
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How can LNG burn?
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@conc btw. 5 and 15
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How does liquefaction occur?
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@ low T
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What are the three ways to form LNG?
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Heat Exchanger, expansion in a turbine, throttling
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What is the difference between the Linde and Claude Liquefaction
processes? |
linde throttles through a valve claude uses an expansion engine
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How many temperature levels are used in the Phillips Cascade
Process and what refrigerants are typically used? |
3 propane, ethylene, methane
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What are CNG and LPG?
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compressed natural gas, liquid pet. gas
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