30 real Refinery & Petrochemical Processes questions from the Plant Operations bank, as asked in Indian campus drives and tech interviews. Every question has a verified answer and an AI-tutor explanation on placd — free to start.
1. What is CDU?
Junior
A.fluid catalytic cracking of vacuum gas oil over zeolite catalyst in a riser at about 500–550 °C, with coke burnt off in a regenerator to supply the heat
B.atmospheric distillation of desalted crude at a furnace outlet of about 350–370 °C into LPG, naphtha, kerosene, diesel and atmospheric residue
C.furnace pyrolysis of naphtha or ethane with steam at 800–880 °C for under a second, then quench, compression and cryogenic separation into ethylene and propylene
D.slurry, gas-phase or solution routes make HDPE and LLDPE; LDPE uses high-pressure tubular or autoclave free-radical polymerisation
2. Which term means: "atmospheric distillation of desalted crude at a furnace outlet of about 350–370 °C into LPG, naphtha, kerosene, diesel and atmospheric residue"?
A.CDU — reformate extraction of BTX, xylene isomerisation and para-xylene recovery by simulated moving-bed adsorption or crystallisation, feeding PTA and polyester
B.CDU — catalytic treatment of naphtha or diesel with hydrogen over CoMo or NiMo at 300–400 °C to reach the BS-VI sulphur limit of 10 ppm
C.CDU — atmospheric distillation of desalted crude at a furnace outlet of about 350–370 °C into LPG, naphtha, kerosene, diesel and atmospheric residue
D.CDU — slurry, gas-phase or solution routes make HDPE and LLDPE; LDPE uses high-pressure tubular or autoclave free-radical polymerisation
A.vacuum distillation of atmospheric residue at 25–40 mmHg to recover vacuum gas oil without thermal cracking, leaving vacuum residue
B.reformate extraction of BTX, xylene isomerisation and para-xylene recovery by simulated moving-bed adsorption or crystallisation, feeding PTA and polyester
C.high-pressure (100–200 bar) hydrogen conversion of heavy gas oil to diesel and jet fuel over dual-function catalyst, giving high-quality middle distillates
D.slurry, gas-phase or solution routes make HDPE and LLDPE; LDPE uses high-pressure tubular or autoclave free-radical polymerisation
5. Which term means: "vacuum distillation of atmospheric residue at 25–40 mmHg to recover vacuum gas oil without thermal cracking, leaving vacuum residue"?
A.VDU — reformate extraction of BTX, xylene isomerisation and para-xylene recovery by simulated moving-bed adsorption or crystallisation, feeding PTA and polyester
B.VDU — high-pressure (100–200 bar) hydrogen conversion of heavy gas oil to diesel and jet fuel over dual-function catalyst, giving high-quality middle distillates
C.VDU — platinum-catalysed conversion of naphtha into high-octane aromatics and hydrogen by dehydrogenation and isomerisation; the CCR type regenerates catalyst continuously
D.VDU — vacuum distillation of atmospheric residue at 25–40 mmHg to recover vacuum gas oil without thermal cracking, leaving vacuum residue
A.fluid catalytic cracking of vacuum gas oil over zeolite catalyst in a riser at about 500–550 °C, with coke burnt off in a regenerator to supply the heat
B.slurry, gas-phase or solution routes make HDPE and LLDPE; LDPE uses high-pressure tubular or autoclave free-radical polymerisation
C.platinum-catalysed conversion of naphtha into high-octane aromatics and hydrogen by dehydrogenation and isomerisation; the CCR type regenerates catalyst continuously
D.catalytic treatment of naphtha or diesel with hydrogen over CoMo or NiMo at 300–400 °C to reach the BS-VI sulphur limit of 10 ppm
8. Which term means: "fluid catalytic cracking of vacuum gas oil over zeolite catalyst in a riser at about 500–550 °C, with coke burnt off in a regenerator to supply the heat"?
A.FCC — slurry, gas-phase or solution routes make HDPE and LLDPE; LDPE uses high-pressure tubular or autoclave free-radical polymerisation
B.FCC — fluid catalytic cracking of vacuum gas oil over zeolite catalyst in a riser at about 500–550 °C, with coke burnt off in a regenerator to supply the heat
C.FCC — furnace pyrolysis of naphtha or ethane with steam at 800–880 °C for under a second, then quench, compression and cryogenic separation into ethylene and propylene
D.FCC — platinum-catalysed conversion of naphtha into high-octane aromatics and hydrogen by dehydrogenation and isomerisation; the CCR type regenerates catalyst continuously
A.thermal cracking of vacuum residue in a furnace with coking in drums switched every 16–24 h, producing coker gas oil and petroleum coke
B.catalytic treatment of naphtha or diesel with hydrogen over CoMo or NiMo at 300–400 °C to reach the BS-VI sulphur limit of 10 ppm
C.high-pressure (100–200 bar) hydrogen conversion of heavy gas oil to diesel and jet fuel over dual-function catalyst, giving high-quality middle distillates
D.atmospheric distillation of desalted crude at a furnace outlet of about 350–370 °C into LPG, naphtha, kerosene, diesel and atmospheric residue
11. Which term means: "catalytic treatment of naphtha or diesel with hydrogen over CoMo or NiMo at 300–400 °C to reach the BS-VI sulphur limit of 10 ppm"?
A.Hydrodesulphurisation — slurry, gas-phase or solution routes make HDPE and LLDPE; LDPE uses high-pressure tubular or autoclave free-radical polymerisation
B.Hydrodesulphurisation — high-pressure (100–200 bar) hydrogen conversion of heavy gas oil to diesel and jet fuel over dual-function catalyst, giving high-quality middle distillates
C.Hydrodesulphurisation — catalytic treatment of naphtha or diesel with hydrogen over CoMo or NiMo at 300–400 °C to reach the BS-VI sulphur limit of 10 ppm
D.Hydrodesulphurisation — platinum-catalysed conversion of naphtha into high-octane aromatics and hydrogen by dehydrogenation and isomerisation; the CCR type regenerates catalyst continuously
A.vacuum distillation of atmospheric residue at 25–40 mmHg to recover vacuum gas oil without thermal cracking, leaving vacuum residue
B.high-pressure (100–200 bar) hydrogen conversion of heavy gas oil to diesel and jet fuel over dual-function catalyst, giving high-quality middle distillates
C.thermal cracking of vacuum residue in a furnace with coking in drums switched every 16–24 h, producing coker gas oil and petroleum coke
D.reformate extraction of BTX, xylene isomerisation and para-xylene recovery by simulated moving-bed adsorption or crystallisation, feeding PTA and polyester
14. Which term means: "high-pressure (100–200 bar) hydrogen conversion of heavy gas oil to diesel and jet fuel over dual-function catalyst, giving high-quality middle distillates"?
A.Hydrocracker — fluid catalytic cracking of vacuum gas oil over zeolite catalyst in a riser at about 500–550 °C, with coke burnt off in a regenerator to supply the heat
B.Hydrocracker — vacuum distillation of atmospheric residue at 25–40 mmHg to recover vacuum gas oil without thermal cracking, leaving vacuum residue
C.Hydrocracker — platinum-catalysed conversion of naphtha into high-octane aromatics and hydrogen by dehydrogenation and isomerisation; the CCR type regenerates catalyst continuously
D.Hydrocracker — high-pressure (100–200 bar) hydrogen conversion of heavy gas oil to diesel and jet fuel over dual-function catalyst, giving high-quality middle distillates
A.reformate extraction of BTX, xylene isomerisation and para-xylene recovery by simulated moving-bed adsorption or crystallisation, feeding PTA and polyester
B.high-pressure (100–200 bar) hydrogen conversion of heavy gas oil to diesel and jet fuel over dual-function catalyst, giving high-quality middle distillates
C.fluid catalytic cracking of vacuum gas oil over zeolite catalyst in a riser at about 500–550 °C, with coke burnt off in a regenerator to supply the heat
D.platinum-catalysed conversion of naphtha into high-octane aromatics and hydrogen by dehydrogenation and isomerisation; the CCR type regenerates catalyst continuously
17. Which term means: "platinum-catalysed conversion of naphtha into high-octane aromatics and hydrogen by dehydrogenation and isomerisation; the CCR type regenerates catalyst continuously"?
A.Catalytic reformer — vacuum distillation of atmospheric residue at 25–40 mmHg to recover vacuum gas oil without thermal cracking, leaving vacuum residue
B.Catalytic reformer — platinum-catalysed conversion of naphtha into high-octane aromatics and hydrogen by dehydrogenation and isomerisation; the CCR type regenerates catalyst continuously
C.Catalytic reformer — high-pressure (100–200 bar) hydrogen conversion of heavy gas oil to diesel and jet fuel over dual-function catalyst, giving high-quality middle distillates
D.Catalytic reformer — catalytic treatment of naphtha or diesel with hydrogen over CoMo or NiMo at 300–400 °C to reach the BS-VI sulphur limit of 10 ppm
A.thermal cracking of vacuum residue in a furnace with coking in drums switched every 16–24 h, producing coker gas oil and petroleum coke
B.high-pressure (100–200 bar) hydrogen conversion of heavy gas oil to diesel and jet fuel over dual-function catalyst, giving high-quality middle distillates
C.reformate extraction of BTX, xylene isomerisation and para-xylene recovery by simulated moving-bed adsorption or crystallisation, feeding PTA and polyester
D.vacuum distillation of atmospheric residue at 25–40 mmHg to recover vacuum gas oil without thermal cracking, leaving vacuum residue
20. Which term means: "thermal cracking of vacuum residue in a furnace with coking in drums switched every 16–24 h, producing coker gas oil and petroleum coke"?
A.Delayed coker — vacuum distillation of atmospheric residue at 25–40 mmHg to recover vacuum gas oil without thermal cracking, leaving vacuum residue
B.Delayed coker — catalytic treatment of naphtha or diesel with hydrogen over CoMo or NiMo at 300–400 °C to reach the BS-VI sulphur limit of 10 ppm
C.Delayed coker — furnace pyrolysis of naphtha or ethane with steam at 800–880 °C for under a second, then quench, compression and cryogenic separation into ethylene and propylene
D.Delayed coker — thermal cracking of vacuum residue in a furnace with coking in drums switched every 16–24 h, producing coker gas oil and petroleum coke
A.reformate extraction of BTX, xylene isomerisation and para-xylene recovery by simulated moving-bed adsorption or crystallisation, feeding PTA and polyester
B.thermal cracking of vacuum residue in a furnace with coking in drums switched every 16–24 h, producing coker gas oil and petroleum coke
C.fluid catalytic cracking of vacuum gas oil over zeolite catalyst in a riser at about 500–550 °C, with coke burnt off in a regenerator to supply the heat
D.furnace pyrolysis of naphtha or ethane with steam at 800–880 °C for under a second, then quench, compression and cryogenic separation into ethylene and propylene
23. Which term means: "furnace pyrolysis of naphtha or ethane with steam at 800–880 °C for under a second, then quench, compression and cryogenic separation into ethylene and propylene"?
A.Steam cracker — atmospheric distillation of desalted crude at a furnace outlet of about 350–370 °C into LPG, naphtha, kerosene, diesel and atmospheric residue
B.Steam cracker — catalytic treatment of naphtha or diesel with hydrogen over CoMo or NiMo at 300–400 °C to reach the BS-VI sulphur limit of 10 ppm
C.Steam cracker — slurry, gas-phase or solution routes make HDPE and LLDPE; LDPE uses high-pressure tubular or autoclave free-radical polymerisation
D.Steam cracker — furnace pyrolysis of naphtha or ethane with steam at 800–880 °C for under a second, then quench, compression and cryogenic separation into ethylene and propylene
A.atmospheric distillation of desalted crude at a furnace outlet of about 350–370 °C into LPG, naphtha, kerosene, diesel and atmospheric residue
B.furnace pyrolysis of naphtha or ethane with steam at 800–880 °C for under a second, then quench, compression and cryogenic separation into ethylene and propylene
C.reformate extraction of BTX, xylene isomerisation and para-xylene recovery by simulated moving-bed adsorption or crystallisation, feeding PTA and polyester
D.fluid catalytic cracking of vacuum gas oil over zeolite catalyst in a riser at about 500–550 °C, with coke burnt off in a regenerator to supply the heat
26. Which term means: "reformate extraction of BTX, xylene isomerisation and para-xylene recovery by simulated moving-bed adsorption or crystallisation, feeding PTA and polyester"?
A.Aromatics complex — slurry, gas-phase or solution routes make HDPE and LLDPE; LDPE uses high-pressure tubular or autoclave free-radical polymerisation
B.Aromatics complex — fluid catalytic cracking of vacuum gas oil over zeolite catalyst in a riser at about 500–550 °C, with coke burnt off in a regenerator to supply the heat
C.Aromatics complex — reformate extraction of BTX, xylene isomerisation and para-xylene recovery by simulated moving-bed adsorption or crystallisation, feeding PTA and polyester
D.Aromatics complex — high-pressure (100–200 bar) hydrogen conversion of heavy gas oil to diesel and jet fuel over dual-function catalyst, giving high-quality middle distillates
A.catalytic treatment of naphtha or diesel with hydrogen over CoMo or NiMo at 300–400 °C to reach the BS-VI sulphur limit of 10 ppm
B.reformate extraction of BTX, xylene isomerisation and para-xylene recovery by simulated moving-bed adsorption or crystallisation, feeding PTA and polyester
C.fluid catalytic cracking of vacuum gas oil over zeolite catalyst in a riser at about 500–550 °C, with coke burnt off in a regenerator to supply the heat
D.slurry, gas-phase or solution routes make HDPE and LLDPE; LDPE uses high-pressure tubular or autoclave free-radical polymerisation
29. Which term means: "slurry, gas-phase or solution routes make HDPE and LLDPE; LDPE uses high-pressure tubular or autoclave free-radical polymerisation"?
A.Polyethylene processes — slurry, gas-phase or solution routes make HDPE and LLDPE; LDPE uses high-pressure tubular or autoclave free-radical polymerisation
B.Polyethylene processes — furnace pyrolysis of naphtha or ethane with steam at 800–880 °C for under a second, then quench, compression and cryogenic separation into ethylene and propylene
C.Polyethylene processes — platinum-catalysed conversion of naphtha into high-octane aromatics and hydrogen by dehydrogenation and isomerisation; the CCR type regenerates catalyst continuously
D.Polyethylene processes — vacuum distillation of atmospheric residue at 25–40 mmHg to recover vacuum gas oil without thermal cracking, leaving vacuum residue
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