Description : For the non catalytic reaction of particles with surrounding fluid, the same needed to achieve the same fractional conversion for particles of different unchanging sizes is proportional to the particle diameter, when the ... through ash layer (C) Chemical reaction (D) Either (A), (B) or (C)
Last Answer : (C) Chemical reaction
Description : For the non-catalytic reaction of particles with surrounding fluid, the time needed to achieve the same fractional conversion for particles of different but unchanging sizes is proportional to the square of particle diameter, ... through ash layer (C) Chemical reaction (D) Either (A), (B) or (C)
Last Answer : (B) Diffusion through ash layer
Description : Which of the following resistances is not involved in a gas phase catalytic (gas-solid) reaction? (A) Ash resistance (B) Gas film and pore surface diffusion resistances for reactants (C) Surface phenomenon resistance (D) Gas film and pore surface diffusion resistances for products
Last Answer : (A) Ash resistance
Description : __________ is the controlling step in a highly temperature sensitive fluid-solid non-catalytic reaction. (A) Gas film diffusion (B) Ash diffusion (C) Chemical reaction (D) None of these
Description : Which one is the rate controlling step in a solid-gas non-catalytic reaction occurring at very high temperature? (A) Pore diffusion (B) Film diffusion (C) Ash layer diffusion (D) Chemical reaction
Last Answer : (B) Film diffusion
Description : Amount of coal lost in ash particle, which is carried through the boiler system, depends upon the (A) Physical nature, ash content and fineness of the coal (B) Amount of excess air supplied and load on the boiler (C) Type of burner and combustion chamber (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : If a solid-gas non-catalytic reaction occurs at very high temperature, the rate controlling step is the __________ diffusion. (A) Film (B) Ash layer (C) Pore (D) None of these
Last Answer : (A) Film
Description : Effectiveness factor of a catalyst pellet is a measure of the __________ resistance. (A) Pore diffusion (B) Gas film (C) Chemical reaction (D) None of these
Last Answer : (A) Pore diffusion
Description : Fixed carbon in coal is defined as (A) That present in volatile matters (B) The total quantity of carbon present in the coal (C) Hundred minus the percentage of volatile matter, ash and moisture (D) The one which is present in the residue after combustion
Last Answer : (C) Hundred minus the percentage of volatile matter, ash and moisture
Description : Which of the following accounts for maximum energy loss in a boiler? (A) Flue gases (B) Ash content in the fuel (C) Incomplete combustion (D) Unburnt carbon in flue gases
Last Answer : (A) Flue gases
Description : A spherical porous catalyst particle of radius R is subjected to reactant A which reacts to form B by a zero order surface reaction A → B. Film mass transfer resistance is negligible and pore diffusion of A ... (D) Effectiveness factor for a zero order reaction cannot be 7/8 as it must always be 1
Last Answer : (A) Inner catalyst core of radius R/8 does not participate in reaction (
Description : What are the major constituents of typical fly ash particles generated from the combustion of coal? w) acidic and basic oxides x) trace elements y) unburned carbon z) sulfates and phosphates
Last Answer : ANSWER: W -- ACIDIC AND BASIC OXIDES
Description : Absorption with chemical reaction' is involved in the removal of (A) Carbon dioxide from gaseous stream using alkaline solution (B) Benzol from coke oven gas using solar oil/wash oil (C) Ammonia ... gas using refrigerated water (D) Tar from coke oven gas in primary gas coolers using chilled water
Last Answer : (A) Carbon dioxide from gaseous stream using alkaline solution
Description : Incomplete combustion of a fuel is characterised by the high __________ in the flue gas. (A) Smoke (B) Temperature (C) Oxygen (D) Carbon monoxide
Last Answer : (D) Carbon monoxide
Description : A coal with high ash content is undesirable, as (A) It is abrasive to the coal pulveriser (i.e. ball mill) and the combustion chamber (B) The ash in molten condition gets absorbed in the pores of the ... and stick to the boiler tubes thereby reducing the heat transfer (D) All (A), (B) and (C)
Description : During combustion of coal on grate, clinker formation is increased by the (A) Use of thick fire bed (B) Low fusion point of ash (< 1100° C) (C) Use of preheated primary air (D) All (A), (B) & (C)
Last Answer : (D) All (A), (B) & (C)
Description : The advantage of firing pulverised coal in the furnace lies in the fact, that it (A) Permits the use of high ash content coal (B) Permits the use of low fusion point ash coal (C) Accelerates the burning rate and economises on fuel combustion (D) All (A), (B) and (C)
Last Answer : (C) Accelerates the burning rate and economises on fuel combustion
Description : Coal is pulverised before burning in large capacity boiler furnaces mainly to (A) Ensure its complete combustion (B) Facilitate easy ash removal (C) Enhance its calorific value (D) Provide trouble free operation
Last Answer : (A) Ensure its complete combustion
Description : Which of the following would require least amount of secondary air for combustion? (A) Coke breeze containing 25% ash and 2% volatile matter (B) Anthracite containing 10% volatile matter and 8% ash ... ash and 25% volatile matter (D) Semi-bituminous coal containing 25% ash and 20% volatile matter
Last Answer : (A) Coke breeze containing 25% ash and 2% volatile matter
Description : Combustion of pulverised fuel (A) Requires larger combustion chamber than rich gaseous fuel (B) In a metallurgical furnace does not contaminate the product in the furnace by ash from fuel (C) Suppresses the discharge of fine dust and grit into atmosphere (D) All (A), (B) and (C)
Last Answer : (A) Requires larger combustion chamber than rich gaseous fuel
Description : During bottling of cold drinks (e.g. Pepsi), the main resistance to mass transfer for the absorption of carbon dioxide in water lies in the (A) Gas film (B) Liquid film (C) Liquid-gas interface
Last Answer : (B) Liquid film
Description : Smog is (A) Nothing but black smoke (B) A combination of smoke and fog (C) A liquid particle resulting from vapor condensation (D) A solid particle e.g. fly-ash
Last Answer : (B) A combination of smoke and fog
Description : The specific gravity of coal depends mainly on its __________ content. (A) Carbon (B) Volatile matter (C) Ash (D) Moisture
Last Answer : (C) Ash
Description : Ultimate analysis of coal determines its __________ content. (A) Carbon, hydrogen, nitrogen & sulphur (B) Carbon, ash, sulphur & nitrogen (C) Carbon, sulphur, volatile matter & ash (D) Carbon, volatile matter, ash & moisture
Last Answer : (A) Carbon, hydrogen, nitrogen & sulphur
Description : Proximate analysis of coal determines its __________ content. (A) Moisture, ash, sulphur & volatile matter (B) Moisture, volatile matter, ash & fixed carbon (C) Moisture, sulphur, nitrogen & fixed carbon (D) None of these
Last Answer : (B) Moisture, volatile matter, ash & fixed carbon
Description : A coal with high __________ content, would ignite most easily. (A) Fixed carbon (B) Volatile matter (C) Ash (D) Oxygen
Last Answer : (B) Volatile matter
Description : Proximate analysis of coal determines its __________ content. (A) Moisture, ash, sulphur & volatile matter (B) Moisture & volatile matter (C) Moisture, sulphur, nitrogen & fixed carbon (D) None of these
Last Answer : (B) Moisture & volatile matter
Last Answer : (C) Carbon, sulphur, volatile matter & ash
Last Answer : Option D
Description : Participation of __________ is involved in the occurrence of a chemical reaction. (A) Protons (B) Neutrons (C) Electrons (D) None of these
Last Answer : (C) Electrons
Description : High ash coals (A) Are soft & friable (poor strength and size stability) (B) Require longer time of carbonisation as ash offers resistance to heat transfer (C) Produce larger quantity of coke oven gas (D) None of these
Last Answer : (A) Are soft & friable (poor strength and size stability)
Description : High ash containing coke (A) Produces more slag when used in the blast furnace (B) Has poor strength and abrasion resistance (C) Is desirable in producer gas manufacture (D) None of these
Last Answer : (A) Produces more slag when used in the blast furnace
Description : Unreacted core model' represents the reaction involving (A) Combustion of coal particles (B) Roasting of sulphide ores (C) Manufacture of carbon disulphide from elements (D) None of these
Last Answer : (B) Roasting of sulphide ores
Description : Gas yield in the Kopper-Totzek coal gasifier is about __________ Nm3 /ton coal (ash = 35%). (A) 150 (B) 1500 (C) 3500 (D) 5000
Last Answer : (C) 3500
Description : One kg of carbon for theoretically complete combustion requires __________ kg of air. (A) 11.5 (B) 0.5 (C) 23 (D) 12
Last Answer : (A) 11.5
Description : Stoichiometric combustion of 12 kg of carbon requires __________ of oxygen. (A) 1kg mole (B) 22.4 Nm3 (C) 32 kg (D) All (A), (B) and (C)
Description : __________ catalytic reaction is involved in the thermal cracking of gas oil. (A) Homogeneous (B) Non-Homogeneous (C) Heterogeneous (D) Non-Heterogeneous
Last Answer : (A) Homogeneous
Description : Pick out the wrong statement. (A) High concentration of oxygen in flue gas means high stack loss (B) Gaseous fuels require the least % excess air for complete combustion (C) The ratio of fixed carbon to ... coal is called its 'fuel ratio' (D) Calorific value of natural gas is more than that of LPG
Last Answer : (D) Calorific value of natural gas is more than that of LPG
Description : Solar energy results from __________ reaction. (A) Fission (B) Combustion (C) Thermonuclear (D) None of these
Last Answer : (C) Thermonuclear
Description : Combustion reaction of fuels is a/an __________ reaction. (A) Auto catalytic (B) Exothermic (C) Endothermic (D) None of these
Last Answer : (B) Exothermic
Description : Which of the following events is heat exchange involved? a. when there is a phase change b. when there is a chemical reaction c. when the gas expands adiabatically d. when there is difference in temperature
Last Answer : when the gas expands adiabatically
Description : A combustion reaction occurs when a substance, usually containing carbon reacts with to produce energy in the form of heat and light?
Last Answer : Oxygen.
Description : The Classical example of redox reaction is Combustion of fossil fuel. During combustion of fossil fuels, the carbon compound in the fossil fuel reacts with oxygen in the presence of a heat source to ... to react with oxygen, so the energy used in portion of combustion is an endothermic reaction.
Last Answer : Combustion of fossil fuel
Description : Mode of heat transfer involved in the cooling of air cooled internal combustion engine is (A) Conduction (B) Natural convection (C) Forced convection (D) None of these
Last Answer : (B) Natural convection
Description : ____ is the transfer of heat from one particle to another by contact. a. Conduction c. Radiation b. Convection d. Combustion
Last Answer : a. Conduction
Description : An alkaline solution is used to reduce the concentration of carbon dioxide in a stream from 10% to 0.1% by absorption with irreversible chemical reaction. The overall number of transfer units based on gas phase is: (A) 9.21 (B) 4.605 (C) 100 (D) 0.001
Last Answer : (B) 4.605
Description : Higher percentage of ash in coal meant for the production of metallurgical grade coke (A) Decreases the hardness of coke (B) Decreases the abrasion resistance of coke (C) Causes brittleness in steel (D) None of these
Last Answer : (D) None of these
Description : Increase in ash content of blast furnace coke (A) Reduces its consumption in the furnace (B) Increases its consumption in the furnace (C) Does not affect its consumption in the furnace (D) Decreases its hardness and abrasion resistance
Last Answer : (B) Increases its consumption in the furnace
Description : Acid dew point temperature (ADT) of a flue gas produced by the combustion of a fuel containing 1% sulphur may be about __________ °C. (A) 80 (B) 130 (C) 180 (D) 250
Last Answer : (B) 130
Description : Efficiency of the combustion of a fuel is judged by the __________ the flue gas. (A) % of CO2 in (B) % of O2 in (C) Temperature of (D) Colour of
Last Answer : (B) % of O2 in