A. Moderate changes in operating temperature does not change the depth of cracking
B. Increased residence time results in the decreased severity of cracking
C. At low pressure, the yield of lighter hydrocarbons are more
D. Greater depth of cracking gives lower octane number gasoline
Related Mcqs:
- Catalytic cracking compared to thermal cracking of residue of vacuum distillation of crude oil__________________?
A. Gives higher yield of petrol
B. Lower octane number of petrol
C. Higher sulphur content in the product
D. Higher gum forming material in petrol - In catalytic cracking process, olefins crack ______________ times faster than in thermal cracking process?
A. 100
B. 200-300
C. 1000-10000
D. 10 - Though increased pressure has a retarding effect on cracking reaction, yet in actual process, a positive pressure of 10-15 kgf/cm2 is maintained during cracking mainly to__________________?
A. Increase the yield of light distillates
B. Suppress coke formation
C. Enhance the octane number of gasoline
D. Reduce gum content in gasoline - Pick out the correct statement pertaining to catalytic cracking ?
A. With increase in the reactor pressure, octane number of gasoline decreases
B. With increase in the reactor temperature, gasoline yield decreases for a given conversion
C. Percentage conversion increases with increase in the catalyst to oil ratio
D. All A., B. and C. - Choose the correct statement ?
A. Octane number of i-octane is zero
B. Octane number of paraffins increases with increasing number of carbon atoms
C. Branched chain paraffins have higher octane number than straight chain paraffins with same number of carbon atoms
D. The aromatics have lower octane number than naphthenes with same number of carbon atoms - Choose the correct statement?
A. Coking tendency increases with increasing molecular weight
B. Coking tendency decreases with increasing molecular weight
C. Higher pressure enhances coke formation
D. Coking is an exothermic reaction - Pressure & temperature maintained in catalytic cracking is about__________________?
A. 2 atm & 500°C
B. 10 atm & 500°C
C. 30 atm & 200°C
D. 50 atm & 750°C - Which of the following is the most widely used cracking process in oil refineries ?
A. Dubbs process
B. T.C.C. moving bed process
C. Fluidised bed catalytic cracking process
D. Houdry’s fixed bed process - Which of the following processes in oil refinery does not employ „cracking‟?
A. Coking
B. Visbreaking
C. Pyrolysis
D. None of these - Catalyst used in the catalytic cracking is_____________________?
A. Silica-alumina
B. Silica gel
C. Vanadium pentoxide
D. Nickel
