Chapter 3: Fuels, Combustion, and Flue Gas Analysis

Question 1

The combustibles in fuel are:
1. Hydrocarbons
2. Carbon
3. Nitrogen
4. Sulfur
5. Hydrogen
Select one:

a.
1, 2, 3, 4

b.
1, 2, 4, 5

c.
3, 4, 5

d.
2, 4, 5

e.
1, 2, 3, 4, 5

Answer 1

b.
1, 2, 4, 5

Question 2

The viscosity is the time, in _____, for 60 cm³ of oil to run through a standard size orifice, at 38°C.
Select one:

a.
Nanoseconds

b.
Seconds

c.
Minutes

d.
Hours

e.
Days

Answer 2

b.
Seconds

Question 3

The amount of NOX formed can be controlled by _____ the amount of excess air used and _____ the temperature in the combustion zone.
Select one:

A.
Increasing, increasing

B.
Restricting, increasing

C.
Increasing, reducing

D.
Eliminating, increasing

E.
Restricting, reducing

Answer 3

E.
Restricting, reducing

Question 4

A2C03Q09 What are the two main constituents in biogas?
Select one:

a.
Hydrogen and carbon monoxide

b.
Methane and hydrogen sulfide

c.
Methane and carbon dioxide

d.
Methane and hydrogen

Answer 4

c.
Methane and carbon dioxide

Question 5

The heating value of natural gas will vary according to its:
Select one:

a.
Colour

b.
Density

c.
Weight

d.
Volume

e.
Constituents

Answer 5

e.
Constituents

Question 6

The heating value of fuel oil, expressed as kJ/kg, _____ with the specific gravity.
Select one:

A.
Varies directly

B.
Varies inversely

C.
Varies inversely with the square of the flow

D.
Varies directly with the square of the temperature

E.
Does not vary

Answer 6

B.
Varies inversely

Question 7

Municipal wastes generally contain large amounts of _____ material that may be suitable for use as a fuel.
Select one:

a.
Biomass

b.
Cardboard

c.
Plastic

d.
Wood

e.
Waste

Answer 7

a.
Biomass

Question 8

If the theoretical amount of air required for the complete combustion of 1 kg of a coal is 10 kg, and the actual amount of air used in the furnace is 12 kg per kg of coal, then the excess air equals:
Select one:

a.
10%

b.
2%

c.
20%

d.
12%

e.
22%

Answer 8

c.
20%

Question 9

A proper natural gas flame will be _____ with a yellow tip.
Select one:

a.
Blue

b.
Yellow

c.
Red

d.
Orange

e.
Black

Answer 9

a.
Blue

Question 10

One method of removing NOX requires injection of _____ in the presence of a _____.
Select one:

a.
Water, heat

b.
Fuel, air

c.
Lead, heat

d.
Ammonia, catalyst

e.
Carbon dioxide, polymer

Answer 10

d.
Ammonia, catalyst

Question 11

Electrostatic precipitators have an efficiency of greater than:
Select one:

a.
75%

b.
80%

c.
85%

d.
90%

e.
95%

Answer 11

e.
95%

Question 12

A2C03Q05 A sample of coal has the following analysis by mass: carbon 80%, hydrogen 8%, sulfur 3%, oxygen 4%, and ash 5%. Calculate the higher heating value of the fuel using Dulong’s formula.
Select one:

a.
39.5 kJ/kg of fuel

b.
38.0 MJ/kg of fuel

c.
38.0 kJ/kg of fuel

d.
39.5 MJ/kg of fuel

Answer 12

b.
38.0 MJ/kg of fuel

Question 13

The heating value of dry wood bark is about:
Select one:

a.
9290 kJ/kg

b.
143 900 kJ/kg

c.
20 000 kJ/kg

d.
37 250 kJ/kg

e.
33 890 kJ/kg

Answer 13

c.
20 000 kJ/kg

Question 14

A2C03Q01 An important principle of __________ is that equations must balance. This means that the number of atoms of each element must balance between the reactants and the products.
Select one:

a.
Analytical chemistry

b.
Mathematical modeling

c.
Stoichiometry

d.
Chemical bonding

Answer 14

c.
Stoichiometry

Question 15

A2C03Q04 What are the essential parts that are required in any type of oxygen bomb calorimeter?
Select one:

a.
Bomb, container, coolant, pressure gauge

b.
Vessel, bucket, coolant, pressure gauge

c.
Vessel, container, insulating jacket, thermometer

d.
Furnace, container, insulating jacket, thermometer

Answer 15

Vessel, container, insulating jacket, thermometer

Question 16

Anthracite coal has a fixed carbon content of at least:
Select one:

a.
80%

b.
60%

c.
92%

d.
88%

e.
75%

Answer 16

c.
92%

Question 17

A2C03Q11 What is the design of flue gas analyzer that uses two electrodes separated by an electrolyte? There is an electrochemical reaction between one electrode and a constituent in the flue gas. This chemical and electrical interaction can be measured, and this small measurement is equated to the concentration of the constituent in the flue gas.
Select one:

a.
Electrochemical sensors

b.
Optical sensors

c.
Electromechanical actuators

d.
Paramagnetic sensors

Answer 17

a.
Electrochemical sensors

Question 18

A2C03Q06 Which main classification of coal is dark brown with a layered structure, and often contains remnants of woody fibres?
Select one:

a.
Sub-bituminous

b.
Anthracite

c.
Lignite

d.
Bituminous

Answer 18

c.
Lignite

Question 19

Which type of fuel requires the smallest amount of excess air?
Select one:

a.
Fuel oil

b.
Natural gas

c.
Pulverized fuel

d.
Wood

e.
Coal

Answer 19

b.
Natural gas

Question 20

An ordinary refined natural gas would typically contain a percentage of methane greater than or equal to:
Select one:

a.
100%

b.
95%

c.
80%

d.
75%

e.
60%

Answer 20

b.
95%