Petroleum Refinery Engineering

51. Cetane number of high speed diesel must be ≥

  1. 30
  2. 45
  3. 75
  4. 95

Correct answer: (B)
45

52. Char value of Kerosene is the amount of charred oil deposition on the wick obtained after burning it in a standard wick lamp at a standard rate for 24 hours. Char value of a good quality kerosene should be less than _________ mg/kg of kerosene.

  1. 1
  2. 20
  3. 100
  4. 500

Correct answer: (B)
20

53. Choose the correct statement regarding thermal cracking.

  1. Moderate changes in operating temperature does not change the depth of cracking
  2. Increased residence time results in the decreased severity of cracking
  3. At low pressure, the yield of lighter hydrocarbons are more
  4. Greater depth of cracking gives lower octane number gasoline

Correct answer: (D)
Greater depth of cracking gives lower octane number gasoline

54. Choose the correct statement.

  1. Octane number of i-octane is zero
  2. Octane number of paraffins increases with increasing number of carbon atoms
  3. Branched chain paraffins have higher octane number than straight chain paraffins with same number of carbon atoms
  4. The aromatics have lower octane number than naphthenes with same number of carbon atoms

Correct answer: (A)
Octane number of i-octane is zero

55. Clay treatment is used to remove

  1. Salt from the crude oil
  2. Colour & dissolved gases from cracked gasoline
  3. Wax from lube oil
  4. None of these

Correct answer: (C)
Wax from lube oil

56. Clay treatment of petroleum products

  1. Decolorizes & stabilises cracked gasoline
  2. Desulphurise straight run gasoline & kerosene
  3. Adsorb arsenic from feedstock to catalytic reforming
  4. All (A), (B) & (C)

Correct answer: (D)
All (A), (B) & (C)

57. Complete removal of _________ from gasoline is done by Unisol process using caustic soda and methyl alcohol.

  1. Waxes
  2. Mercaptans
  3. Asphalt
  4. Diolefins

Correct answer: (B)
Mercaptans

58. Concentration of H2SO4 catalyst in alkylation is kept between 90-98%, because H2SO4 having concentration.

  1. Less than 90% promotes polymerisation
  2. More than 98% promotes cracking
  3. Both (A) and (B)
  4. Neither (A) nor (B)

Correct answer: (C)
Both (A) and (B)

59. Cracking is

  1. An exothermic reaction
  2. An endothermic reaction
  3. Favoured at very low temperature
  4. None of these

Correct answer: (B)
An endothermic reaction

60. Crude oil is pumped by a _________ pump.

  1. Gear
  2. Centrifugal
  3. Screw
  4. Reciprocating

Correct answer: (B)
Centrifugal

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