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

1 Answer

Answer :

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

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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 : 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 : Phenolic water generated in coke ovens & by-product plant of a steel plant are disposed off by (A) Quenching of hot coke (B) Discharging in the river stream (C) Filtration and recycling for cooling coke oven gas (D) None of these

Last Answer : (A) Quenching of hot coke

Description : Regenerators are used for waste heat recovery in (A) By-product coke ovens (B) Beehive coke oven (C) Blast furnace stoves (D) Soaking pits

Last Answer : (A) By-product coke ovens

Description : Coke ovens in steel plant are heated by (A) Electricity (B) Blast furnace gas/mixed gas (C) Coke oven gas (D) Both (B) and (C)

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

Description : Coke ovens in steel plant are heated by (A) Electricity (B) Coke oven gas (C) Mixed gas (D) Both (B) & (C)

Last Answer : (D) Both (B) & (C)

Description : Compound coke ovens are those which can be heated by (A) Both steam and electrical power (B) Lean gas (e.g., B.F. gas) (C) Rich gas (e.g., coke oven gas) (D) Both (B) and (C)

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

Description : 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)

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

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 : 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 : 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 : 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 : Fuel used in B.F. stove is (A) Pulverised coal (B) Furnace oil (C) Blast furnace gas/mixed gas (D) Coke oven gas

Last Answer : (C) Blast furnace gas/mixed gas

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 : Sometimes water is sprayed during coal charging in the coke oven, which helps in (A) Prevention of clinker formation in the oven (B) Controlling the dust nuisance while charging the coal (C) Reducing the cracking of hydrocarbons in ... represented by C + H2O = CO + H2 ) (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 : 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 : Which of the following would require maximum amount of % excess air for complete combustion? (A) Coke oven gas (B) Furnace oil (C) Pulverised coal (D) Lump coal (fixed on chain grate)

Last Answer : (D) Lump coal (fixed on chain grate)

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 : 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 : 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 : 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 : 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

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Description : A fertiliser plant is classified as a gas based fertiliser plant, when it uses__________ gas as a source of hydrogen for the manufacture of ammonia. (A) Coke oven (B) Producer (C) Natural (D) Coal

Last Answer : (C) Natural

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Last Answer : (C) Tar

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Last Answer : (A) By fractionation of liquefied air

Description : Which of the following is the costliest source of getting hydrogen on commercial scale for the manufacture of nitrogenous fertiliser? (A) Coal gasification (B) Steam reforming of naphtha (C) Electrolysis of water (D) Coke oven gas

Last Answer : (C) Electrolysis of water

Description : Regenerators are normally provided in the (A) Glass melting furnace (B) Open hearth furnace (C) By product coke ovens (D) All (A), (B) and (C)

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

Description : Regenerators are normally provided in the (A) Glass melting furnace (B) Open hearth furnace (C) By product coke ovens (D) All (A), (B) and (C)

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

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 : Coke made in narrower by-product coke ovens (as compared to wider ovens) is (A) Less reactive (B) Stronger (C) Smaller in size (D) All (A), (B) & (C)

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

Description : Pick out the wrong statement. (A) Nitrogen is normally supplied in fertiliser either in Ammoniacal or the nitrate form, from which the soil takes it up in the form of ammonium ions ornitrate ... nitrate fertiliser is obtained as a by-product in an integrated steel plant having by-product coke ovens

Last Answer : (D) Ammonium nitrate fertiliser is obtained as a by-product in an integrated steel plant having by-product coke ovens

Description : Phenolic water generated in coke ovens & by-product plant attached to an integrated steel plant containing phenol in concentration of less than 100 mg/litre can be removed by (A) Chlorination (B) Treating in biological oxygen pond (C) Chemical coagulation (D) None of these

Last Answer : (B) Treating in biological oxygen pond

Description : For which pair of the fuel gases, calorific value (C.V.) of one fuel is almost double that of the other on volume basis (i.e., kcal/Nm3 ), while the C.V. is same on weight basis (i.e., kcal/kg)? (A) Propane and acetylene (B) Propane and LPG (C) Sewage gas and gobar gas (D) B.F. gas and coke oven gas

Last Answer : (A) Propane and acetylene

Description : For which pair of the fuel gases, calorific value (C.V.) of one fuel is almost double that of the other on volume basis (i.e., kcal/Nm3) while the C.V. is same on weight basis (i.e., kcal/kg)? (A ... and acetylene (B) Propane and LPG (C) Sewage gas and gobar gas (D) B.F gas and coke oven gas

Last Answer : D) B.F gas and coke oven gas

Description : Which of the following gas is mostly used in town for street and domestic lighting and heating?  A. Producer gas  B. Coal gas  C. Mond gas  D. Coke oven gas

Last Answer : Answer: B

Description : In regenerative air preheater (as practised in heating of coke ovens), the heat is transferred (A) Through a metallic wall (B) By direct contact of hot flue gas with air (C) By ... material (like chequor bricks) and then heating the air from this hot material (D) None of these

Last Answer : (C) By heating an intermediate material (like chequor bricks) and then heating the air from this hot material

Description : Flue gas from the heating chamber of byproduct coke ovens is removed by (A) Forced draft fan (B) Induced draft fan (C) Steam ejector (D) Natural draft

Last Answer : (D) Natural draft

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 : Blast furnace coke is made from coal by (A) Low temperature carbonisation (B) High temperature carbonisation (C) Medium temperature carbonisation (D) Heating the coal in an oven in presence of air

Last Answer : (B) High temperature carbonisation

Description : With increase in the time of carbonisation at a particular temperature(say 1000°C), the __________ percentage in coke oven gas increases. (A) Hydrogen (B) Methane (C) Unsaturated hydrocarbons (D) All (A), (B) and (C)

Last Answer : (A) Hydrogen

Description : Which of the following is not a by-product fuel? (A) Producer gas (B) Blast furnace gas (C) Coke oven gas (D) Refinery gas

Last Answer : (A) Producer gas

Description : Naphthalene is removed from coke oven gas by (A) Scrubbing with wash oil (a petroleum product) (B) Adsorbing on bog iron bed (C) Absorbing in vetro-coke solution (D) None of these

Last Answer : (A) Scrubbing with wash oil (a petroleum product)

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 : Low temperature oxidation of stored coal results in the (A) Decrease in its caking power & calorific value (B) Decrease in its carbon & hydrogen content (C) Increase in its oxygen content (D) All (A), (B) and (A)

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

Description : Are gas oven more of a fire risk than electric ovens?

Last Answer : A gas oven is more of a fire risk because of the open flame. If anything flamable comes into contact with the flame it can ignite causing a fire. Electric ovens can cause fires too but not as easily as gas.