A. pulverising coal in inert atmosphere
B. heating wood in a limited supply of air at temperatures below 300°C
C. strongly heating coal continuously for about 48 hours in the absence of air in a closed vessel
D. binding the pulverised coal into brick-ettes
E. enriching carbon in the coal
Related Mcqs:
- The coal requirement per kW hour generation in the thermal power plant is of the order of__________________?
A. 0.1 to 0.2 kg
B. 0.2 to 0.4 kg
C. 0.6 to 0.8 kg
D. 1.0 to 1.5 kg
E. 1.5 to 2 kg - Hard coke is produced by carborisation of coal at_______________?
A. atmospheric temperature
B. 500-600°C
C. 70O-850°C
D. 95O-1100°C
E. 120O-1500°C - The bituminous coal is non-caking if its carbon content is_______________?
A. 78-81%
B. 81-85%
C. 85-90%
D. 90-95%
E. 95-100%. - Which is not the correct statement about moisture in coal ______________________?
A. inherent moisture and surface mois¬ture are different things
B. in some coals moisture may be present upto 40%
C. some moisture in coal helps in better burning which is not possible with completely dry coal
D. it increases thermal efficiency
E. moisture in coal is removed before firing by heating it with hot air - During storage, the heating value of coal __________________?
A. increases
B. decreases
C. remains constant
D. may increase or decrease depending upon the method of storage
E. none of the above - Calorific value of coal is of the order of _______________________?
A. 200-400 kcal/kg
B. 800-1200 kcal/kg
C. 2000-4000 kcal/kg
D. 5000-8000 kcal/kg
E. 8000-10,000 kcal/kg - Green coal, in order to be burnt, must be____________________?
A. heated sufficiently
B. burnt in excess air
C. heated to its ignition point
D. burnt as powder
E. burnt as lumps - Sulphur in coal results in___________________?
A. causing clinkering and slagging
B. corroding air heaters
C. spontaneous combustion during coal storage
D. facilitating ash precipitation
E. all of the above - The behaviour of coal in a furnace is determained by_______________________?
A. the content of sulphur
B. the content of ash and heating value
C. the proximate analysis
D. the exact analysis
E. its type - On Mollier chart, free expansion, or throttling process from high pressure to atmosphere is represented by_______________?
A. horizontal straight line
B. vertical straight line
C. straight inclined line
D. curved line
E. none of the above
