Free Chemical Process Principles MCQs with Answers

• A. Natural draft
• B. Induced draft fan
• C. Steam ejector
• D. Forced draft fan

Explanation: By-product coke ovens commonly use natural draft through the chimney to draw the heating-chamber flue gases through the regenerator and…

• A. M = 1.8 A
• B. M = 1.1 A
• C. M = 0.5 A
• D. M = A

Explanation: Ash is the residue measured after coal is completely burned, while mineral matter includes components altered or lost during combustion.

• A. Develops a non-luminous flame
• B. Develops a low temperature flame
• C. Can be done with less excess air
• D. Provides a lower rate of heat release

Explanation: Pulverising coal greatly increases its surface area, allowing faster and more complete combustion with better air-fuel mixing.

• A. Pitch and creosote oil
• B. Light oil and pitch
• C. Anthracene and crecosote oil
• D. Solar oil and pitch

Explanation: CTF 200 is prepared by blending pitch with creosote oil to obtain a usable coal-tar fuel.

• A. Prevention of clinker formation in the oven
• B. Controlling the dust nuisance while charging the coal
• C. All A., B. and C.
• D. H2 in the gas (due to the endothermic reaction represented by C + H2O = CO + H2)
• E. Reducing the cracking of hydrocarbons in the gas and increasing the percentage of CO &

Explanation: Water spraying during charging suppresses coal dust, helps prevent clinker formation, and supplies steam that limits hydrocarbon cracking…

• A. CO2, CO, O2
• B. CO, O2, CO2
• C. CO2, O2, CO
• D. O2, CO2, CO

Explanation: Orsat analysis absorbs carbon dioxide first with alkali, oxygen next with alkaline pyrogallol, and carbon monoxide last with ammoniacal…

• A. Caking index
• B. Yield of carbonised products
• C. Calorific value
• D. Friability & oxygen content

Explanation: Weathering oxidizes coal and weakens its structure, making it more friable while increasing its oxygen content.

• A. Reactivity
• B. Hardness
• C. Strength
• D. None of these

Explanation: The Critical Air Blast value indicates the air rate at which coke begins rapid combustion, so it is used as a measure of coke reactivity.

• A. Shows little or no fusing action
• B. Gives smokeless burning
• C. Burns completely
• D. None of these

Explanation: Free-burning coal burns readily because it undergoes little or no softening and fusion during heating.

• A. Carbon, sulphur, volatile matter & ash
• B. Carbon, ash, sulphur & nitrogen
• C. Carbon, hydrogen, nitrogen & sulphur
• D. Carbon, volatile matter, ash & moisture

Explanation: Ultimate analysis gives the elemental composition of coal, particularly carbon, hydrogen, nitrogen and sulphur, often with oxygen…

• A. Proper fuel preparation
• B. Supplying correct quantity of combustion air
• C. Adopting efficient-fuel firing technique & equipment
• D. Keeping the flue gas exhaust temperature very high

Explanation: Very hot exhaust gas carries a large amount of sensible heat out of the furnace, increasing stack heat loss.

• A. Dry gas/stack gas loss
• B. Incomplete combustion
• C. Moisture loss
• D. None of these

Explanation: Excess oxygen in flue gas indicates excess air, which increases the mass of dry gas leaving the stack and hence the dry-gas or stack-gas…

• A. Incomplete combustion
• B. Complete combustion
• C. High oxygen in flue gas
• D. None of these

Explanation: A non-luminous, blue flame generally indicates that the gaseous fuel is mixing well with sufficient oxygen and burning completely.

• A. Fischer-Tropsch
• B. Lurgi
• C. Bergius
• D. None of these

Explanation: The Bergius process directly hydrogenates pulverised coal under high temperature and pressure to form liquid hydrocarbons.

• A. 11.5
• B. 0.5
• C. 23
• D. 12

Explanation: One kilogram of carbon needs 2.67 kg of oxygen, and since air contains about 23% oxygen by mass, the theoretical air required is…

• A. CO2
• B. CO
• C. O2
• D. C

Explanation: Incomplete combustion converts part of the carbon to carbon monoxide rather than carbon dioxide, so CO increases in the flue gas.

• A. As moisture proof coating on fibres
• B. As a fuel in furnaces
• C. As moth balls (insecticides)
• D. For making electrodes

Explanation: Naphthalene sublimes readily and its vapour is toxic to many insects, which is why it is used in mothballs.

• A. Coal can be pulverised with great difficulty
• B. Coal can't be pulverised
• C. Power consumption in grinding the coal will be very high
• D. Coal can be easily pulverised

Explanation: A high grindability index means the coal breaks down readily during pulverisation and requires relatively less grinding energy.

• A. Aromatic content of tar produced is more
• B. Tar yield is more
• C. Ignition temperature of coke produced is less
• D. Gas yield is less

Explanation: High-temperature carbonisation produces tar with a greater proportion of aromatic compounds because stronger thermal cracking and…

• A. Furnace oil
• B. Semi-coke
• C. Bagasse
• D. Kerosene

Explanation: Bagasse is an agricultural residue obtained directly from sugarcane and is therefore a natural or by-product fuel.