Preheating of coal charge for the coke ovens reduces the
(A) Time of carbonisation
(B) Yield of gas and tar
(C) Fuel consumption in coking
(D) All (A), (B) and (C)

1 Answer

Answer :

(D) All (A), (B) and (C)

Related questions

Description : Presence of free moisture in coal during its high temperature carbonisation (A) Reduces the coking time (B) Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot oven walls (C) Increases the loss of fine coal dust from the ovens when charging (D) None of these

Last Answer : (B) Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot oven walls

Description : Beehive coke oven (A) Facilitates by-products recovery (B) Takes 2-3 days for coking of coal but requires no external fuel for heating (C) Gives larger yield of coke (around 85%) as compared to by-product ovens (D) Produces coke with very poor strength

Last Answer : (B) Takes 2-3 days for coking of coal but requires no external fuel for heating

Description : In high temperature carbonisation (as compared to low temperature carbonisation) of coal, the (A) Gas yield is less (B) Tar yield is more (C) Ignition temperature of coke produced is less (D) Aromatic content of tar produced is more

Last Answer : (D) Aromatic content of tar produced is more

Description : In high temperature carbonisation (as compared to low temperature carbonisation) of coal (A) Coke oven gas yield is more (B) Tar yield is less but free carbon in tar is more (C) Calorific value of coke oven gas is less (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : In low temperature carbonisation of coal as compared to high temperature carbonisation __________ produced is less. (A) Difference in gross & net calorific value of the coke oven gas (B) Free carbon content in tar (C) Yield percentage of coke (D) Yield of ammonia present in coke oven gas

Last Answer : (A) Difference in gross & net calorific value of the coke oven gas

Description : In low temperature carbonisation of coal, the (A) Yield of coke oven gas is 290 Nm3 /ton dry coal (B) Volatile matter in coke is zero (C) Temperature maintained is 700°C (D) Yield of tar is about 3% of dry coal

Last Answer : (C) Temperature maintained is 700°C

Description : In high temperature carbonisation of coal compared to low temperature carbonisation (A) Yield of ammonia is less (B) Aromatic content of tar is low (C) H2 content in the coke oven gas is more (D) Calorific value of the coke oven gas is lower

Last Answer : (C) H2 content in the coke oven gas is more

Description : With increases in carbonisation temperature (A) Coke even gas yield increases (B) Tar yield increases (C) Hydrogen percentage in the coke oven gas decreases (D) Methane percentage in the coke oven gas increases

Last Answer : (A) Coke even gas yield increases

Description : Fuel consumption in coke making can be reduced by (A) Preheating, blending and de-ashing the coal (B) Stamped charging of coal (C) Dry quenching of coke (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Which of the following fuels is generally not used in thermal power plant boiler firing? (A) Furnace oil, light diesel oil and tar/PCM (B) Pulverised coking coal (C) Coal middling from washeries (D) B.F. gas, coke oven gas and L.D. converter gas

Last Answer : (B) Pulverised coking coal

Description : The main product of high temperature carbonisation of coal is (A) Coke (B) Ammonia (C) Tar (D) Coke oven gas

Last Answer : (A) Coke

Description : Fussain (A) Is friable, charcoal like substance (B) Has highest fixed carbon and lowest volatile matter content of all the four banded components of coal (C) Is non-coking, but when blended with highly coking ... its swelling and produces high strength coke on carbonisation (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Prime coking coal is always blended with medium or non- coking coal before carbonisation (A) To check against its excessive swelling during heating, which may exert high pressure and damage coke oven walls (B) Because, it alone produces unreactive coke (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) and (B)

Description : High rate of heating of coke ovens (A) May damage its walls due to abrupt excessive swelling of coal (B) Produces larger size coke (C) Increases the time of carbonisation (D) None of these

Last Answer : (A) May damage its walls due to abrupt excessive swelling of coal

Description : Heat penetration rate in narrow coke ovens in high temperature carbonisation of coal is around __________ cm/hr. (A) 2.5 (B) 0.5 (C) 10 (D) 20

Last Answer : (A) 2.5

Description : Pick out the wrong statement. (A) Percentage of ash in coke produced from medium coking coal is more than that in coal (B) The calorific value (kcal/Nm3 ) of coke oven gas reduces on ... plants in India at Talcher (Orissa) and Ramagundam (A.P) employ Kopper-Totzek process of coal gasification

Last Answer : (C) Ash is normally removed as 'fly-ash' in Kopper-Totzek process of coal gasification

Description : High temperature carbonisation of coal produces (A) Inferior coke compared to low temperature carbonisation (B) Less of gases compared to liquid products (C) Large quantity of tar compared to low temperature carbonisation (D) None of these

Last Answer : (D) None of these

Description : During the carbonisation of coal (A) All tar is evolved at < 600°C (B) Evolution of H2 and formation of methane and aromatics occur at > 700°C (C) Hard semi-coke starts shrinking at 600°C (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : High temperature carbonisation of coal produces (A) Inferior coke compared to low temperature carbonisation (B) Less of gases compared to liquid products (C) Larger quantity of tar compared to low temperature carbonisation (D) None of these

Last Answer : (D) None of these

Description : The main product of high temperature carbonisation of coal is (A) Coke (B) Ammonia (C) Tar (D) Phenol

Last Answer : (A) Coke

Description : Tar yield in the low temperature and high temperature carbonisation of dry coal may be respectively __________ percent. (A) 3 & 10 (B) 10 & 3 (C) 10 & 20 (D) 15 & 8

Last Answer : (B) 10 & 3

Description : In low temperature carbonisation (as compared to high temperature carbonisation) of coal (A) Ammonia yield is more (B) Aliphatic tar is produced (C) Free carbon in tar is more (D) All (A), (B) and (C

Last Answer : (B) Aliphatic tar is produced

Description : The yield of tar from high temperature carbonisation of dry coal is about __________ percent. (A) 3 (B) 12 (C) 22 (D) 0.3

Last Answer : (A) 3

Description : Yield of coke oven gas in low temperature carbonisation of coal is about __________ Nm3 /ton of dry coal. (A) 60 (B) 160 (C) 500 (D) 750

Last Answer : (B) 160

Description : A coal having higher volatile matter content, has lower (A) Smoking tendency on burning (B) Coke oven gas yield on carbonisation (C) Chance of catching fire during storage in open space (D) Ignition temperature

Last Answer : (D) Ignition temperature

Description : Coking time in narrow by-product coke ovens is around __________ hours. (A) 18 (B) 48 (C) 8 (D) 80

Last Answer : (A) 18

Description : Narrow coke ovens as compared to wider coke ovens (A) Produce smaller coke (B) Produce stronger coke (C) Require less time of carbonisation (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Main use of hard coke produced by high temperature carbonisation is in the (A) Iron blast furnace (B) Cupola in foundries (C) Sinter making (D) Domestic ovens

Last Answer : (A) Iron blast furnace

Description : Soft coke is not (A) Produced by low temperature carbonisation of coal (B) A domestic fuel (C) Used in blast furnaces (D) None of these

Last Answer : (C) Used in blast furnaces

Description : A coal having high amount of volatile matter (A) Would require smaller combustion chamber (B) Produces very little of tar and gas on carbonisation (C) Ignites easily and burns with long smoky flame (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : A coal having high amount of volatile matter (A) Would require smaller combustion chamber (B) Produces very little of tar and gas on carbonisation (C) Ignites easily and burns with long smoky flame (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Coking time in a commercial high temperature coal carbonisation plant is about __________ hours. (A) 6 (B) 18 (C) 28

Last Answer : (B) 18

Description : Pick out the wrong statement. (A) Indian coals on an average contain 25-30% ash as against 10-12% ash in imported coking coal (B) Ammonia is recovered in the form of ammonium sulphate in direct ... indicates poor caking properties of coal (D) Wash oil is used for scrubbing Benzol from coke oven gas

Last Answer : (C) A high swelling index number of coking coal indicates poor caking properties of coal

Description : . By-products recovery process from coal carbonisation is termed asdirect, indirect and semi direct process depending upon the method of recovery of (A) Tar (B) Benzol (C) Ammonia (D) None of these

Last Answer : (C) Ammonia

Description : Coal tar (produced by high temperature carbonisation) is the main source of (A) Aromatic compounds (B) Aliphatic compounds (C) Paraffins (D) Olefins

Last Answer : (A) Aromatic compounds

Description : Quantity of coke oven gas produced by high temperature carbonisation of one ton of dry coal may be around __________ Nm3 . (A) 30 (B) 300 (C) 3,000 (D) 30,000

Last Answer : (B) 300

Description : Coke oven gas produced by high temperature carbonisation of coal (as compared to that produced by low temperature carbonisation), has (A) Higher calorific value (B) Lower hydrogen content (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (D) Neither (A) nor (B)

Description : Low temperature carbonisation of coal produces (A) Metallurgical coke (B) Soft coke (C) Very low calorific value coke oven gas (D) No by-products

Last Answer : (B) Soft coke

Description : Calorific value of coke even gas produced by low temperature carbonisation of coal is about __________ Kcal/Nm3 . (A) 4000 (B) 2500 (C) 6500 (D) 10000

Last Answer : (C) 6500

Description : With increase in the temperature of carbonisation of coal (A) Hydrogen content of coke oven gas increases due to cracking ofhydrocarbons (B) Methane content in the coke oven gas decreases and carbon monoxide content increases ( ... compensated by increase in CO & H2 content (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Pick out the wrong statement: (A) Carburetted water gas is also called blue gas (B) Coals are divided in four species according to their carbon content in Seylor's classification (C) Carbonisation time ... and net calorific value of a fuel is the same, if it does not contain hydrogen or hydrocarbons

Last Answer : (A) Carburetted water gas is also called blue gas

Description : Undercharging of coal in the by-product coke ovens results in (A) Decrease in the c.v. of coke oven gas (B) Increase in its throughput (C) Increase in the c.v. of coke oven gas

Last Answer : (A) Decrease in the c.v. of coke oven gas

Description : Producer gas is obtained by  A. partial combustion of coal, coke, anthracite coal or charcoal in a mixed air steam blast  B. carbonisation of bituminous coal  C. passing steam over incandescent coke  D. passing air and a large amount of steam over waste coal at about 650°C

Last Answer : Answer: A

Description : Producer gas is obtained by  A. partial combustion of coal, coke, anthracite coal or charcoal in a mixed air steam blast  B. carbonisation of bituminous coal  C. passing steam over incandescent coke  D. passing air and a large amount of steam over waste coal at about 650°C

Last Answer : Answer: A

Description : Producer gas containing least amount of tar is produced by the (A) Partial combustion of coal (B) Partial combustion of large size (< 50 mm) coke (C) High pressure gasification of coal (e.g. in Lurgi gasifier) (D) Atmospheric pressure gasification of coal (e.g., in Kopper-Totzek gasifier)

Last Answer : (B) Partial combustion of large size (< 50 mm) coke

Description : Which of the following is not a commercially used feed-stock for the production of ammonia synthesis gas? (A) Water (B) Naphtha (C) Tar (D) Coal/coke oven gas

Last Answer : (C) Tar

Description : Washing of coal (A) Reduces its sulphur and ash content (B) Controls its ash fusibility and increases its calorific value (C) Improves its coking properties (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Washing of coal (A) Reduces its ash & sulphur content (B) Improves its coking properties (C) Increase the fusion point of its ash by removing chlorine compounds (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Anthracite can be used for (A) Recarbonising steel (B) Making carbon electrodes (C) Blending with highly coking coal to check its swelling which helps in saving coke even walls from damage and to produce high strength coke (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)