Tag: fossil fuels

Questions Related to fossil fuels

Which of the following is a measurement method for octane number?

  1. Research octane number (RON)

  2. Motor octane number (MON)

  3. Anti-knock index (AKI)

  4. All of the above


Correct Option: D
Explanation:

Octane number can be determined by all the three methods. The most common method used for the measurement is RON. RON is determined by running the fuel in a test engine and comparing the results with those for mixtures of iso-octane and $n$-heptane.

Anti-knock index (AKI) is the:

  1. geometric mean of RON and MON

  2. arithmetic mean of RON and MON

  3. harmonic mean of RON and MON

  4. none of the above


Correct Option: B
Explanation:

Octane number can be determined by RON, MON and AKI. The most common method used for the measurement is RON. AKI is the arithmetic mean of RON and MON. 

It is given by : $\frac{R+M}{2}$. 
It is sometimes called as posted octane number.

With increase in octane number:

  1. cetane number decreases

  2. activation energy increases

  3. both A & B

  4. neither A nor B


Correct Option: C
Explanation:

Higher is the octane number higher is the activation energies. Activation energy is the amount of energy required to initiate combustion. 

Cetane number is the fuel's eagerness to ignite from the heat created in the bore from the compression of the air. Higher is the cetane number lower is the octane number.

A fuel with a higher octane rating:

  1. is less prone to auto-ignition

  2. can withstand a greater rise in temperature during the compression stroke

  3. has lower cetane number

  4. has lesser knocking


Correct Option: A,B,C,D
Explanation:
  • The fuels with higher octane ratings will require high activation energies and are less prone to auto-ignition.
  • They can withstand the greater rise in temperature during the compression stroke of an internal combustion engine without auto igniting and thus allow more power to be extracted.
  • They have lower cetane number. Cetane number and octane rating are opposite to each other.
  • A fuel with higher octane rating leads to less engine knocking.

The RON/MON value of iso-octane is:

  1. $0$

  2. $100$

  3. $50$

  4. $1000$


Correct Option: B
Explanation:

Octane number can be determined by RON, MON and AKI. The most common method used for the measurement is RON. RON is determined by running the fuel in a test engine and comparing the results with those for mixtures of iso-octane and $n$- heptane. The RON/MON values of iso-octane is 100.

Which is the most common type of octane rating worldwide?

  1. MON

  2. RON

  3. AKI

  4. Aviation gasoline octane rating


Correct Option: B
Explanation:

Octane number can be determined by RON, MON and AKI.The most common method used for the measurement is RON. 

RON is determined by running the fuel in a test engine and comparing the results with those for mixtures of isooctane and $n$- heptane. 

The activity of the catalyst in a semi-regenerative catalytic reformer is reduced over time during operation by:

  1. chloride loss

  2. carbonaceous coke

  3. both A and B together

  4. either A or B


Correct Option: C
Explanation:

In catalytic reforming process, the noble metals platinum and rhenium are the catalysts used on a silica or silica-alumina support base. Fresh catalyst is chlorinated prior to use. On the other hand, an excessive chlorination could depress excessively the activity of the catalyst. Also in the case of the semi-regenerative catalytic reformer, the catalyst is reduced over time by carbonaceous coke deposition and chlorine loss.

The support base used for the noble metals in catalytic reforming is/are: 

  1. alumina

  2. silica

  3. silica-alumina

  4. all


Correct Option: B,C
Explanation:

In catalytic reforming process, high octane number reformate is formed which is the main component of the motor, fuel, aviation gasoline or aromatic rich feedstock. The noble metals platinum and rhenium are the catalysts used on a silica or silica-alumina support base. Fresh catalyst is chlorinated prior to use.

The fresh catalyst in catalytic reforming of petroleum is _______ prior to use.

  1. amalgamated

  2. brominated

  3. chlorinated

  4. oxygenated


Correct Option: C
Explanation:

In catalytic reforming process; high octane number reformate is formed which is the main component of the motor, fuel, aviation gasoline or aromatic rich feedstock. The noble metals platinum and rhenium are the catalysts used on a silica or silica-alumina support base. Fresh catalyst is chlorinated prior to use.

Hydrogenolysis reaction produces:

  1. heavy hydrocarbons

  2. light hydrocarbons

  3. only methane

  4. only butane


Correct Option: B
Explanation:

Hydrogenolysis is a reaction where hydrogen is added to a compound and breaks that compound’s bonds, forming two molecules. This results in the formation of lighter hydrocarbons.