LESSON 9 | FUEL CHEMISTRY

Question 1

any combustible substance that contains carbon as a main
constituent, which on proper burning gives a large amount of
useful heat for domestic and industrial purposes

Answer 1

FUEL

Question 2

During the complete combustion of fuels, carbon is
converted to

hydrogen is converted to

Answer 2

CO2

H2O

Question 3

the process of oxidation that provides heat energy

Answer 3

Combustion

Question 4

Every combustion is an oxidation but every oxidation is not combustion.

Answer 4

Combustion

Question 5

The fuel should be easily available.

Answer 5

TRUE

Question 6

It should be dry and should have less moisture content. Dry
fuel increases its calorific value.

Answer 6

TRUE

Question 7

It should be cheap, easily transportable and has high calorific
value.

Answer 7

TRUE

Question 8

It must have moderate ignition temperature and should
leave less ash after combustion.

Answer 8

TRUE

Question 9

The combustion speed of a good fuel should be moderate.

Answer 9

TRUE

Question 10

It should not burn spontaneously to avoid fire hazards.

Answer 10

TRUE

Question 11

Its handling should be easy and should not give poisonous
gases after combustion.

Answer 11

TRUE

Question 12

The combustion of a good fuel should not be explosive.

Answer 12

TRUE

Question 13

Classification of Fuels

Answer 13

occurrence (and preparation)
physical state

Question 14

found in nature

Answer 14

natural or primary fuels

Question 15

used either without processing or after being processed to a certain
extent, which does not alter the chemical composition of the fuel

Answer 15

natural or primary fuels

Question 16

also known as fossil fuels such as wood, peat, lignite, coal, petroleum,
natural gas, etc.

Answer 16

natural or primary fuels

Question 17

derived from the primary fuels by further processing such as charcoal, coke, kerosene,
producer gas, water gas, etc.

Answer 17

artificial or secondary fuels

Question 18

The second classification is based on the

Answer 18

physical state.

Question 19

Type of Fuels

Answer 19

■ 1. Solid fuels
■ 2. Liquid fuels
■ 3. Gaseous fuels

Question 20

The Philippines had a significant growth in power generation
at 10% from 82,413,213 MW in 2015 to 90,797,891 MW in
2016.

Answer 20

TRUE

Question 21

The main solid fuels are wood, peat, lignite, coal and charcoal.

Answer 21

Solid Fuels

Question 22

a fossil fuel which occurs in layers in the earth’s crust

Answer 22

COAL

Question 23

It is formed by the partial decay of plant and animal materials
accumulated millions of years ago and further altered by action of
heat and pressure.

Answer 23

COAL

Question 24

Conversion of wood into coal

Answer 24

Wood ⟶Peat ⟶ Lignite ⟶Bituminous Coal ⟶ Anthracite

Question 25

a brown-fibrous jelly like mas

Answer 25

Peat

Question 26

soft, brown colored, lowest rank type of coal

Answer 26

LIGNITE

Question 27

a class of highest rank coa

Answer 27

Anthracite

Question 28

pitch black to dark grey

Answer 28

Bituminous coal

Question 29

are the important commercial and domestic fuels used these days.

Answer 29

Liquid Fuels

Question 30

Most of these fuels are obtained from the naturally occurring petroleum or crude oil.

Answer 30

Liquid Fuels

Question 31

is a dark greenish brown, viscous oil found deep in the earth crust.

Answer 31

Petroleum or crude oil

Question 32

is a source of many liquid fuels that are in current use.

Answer 32

Petroleum or crude oil

Question 33

Approximate composition of crude petroleum

Answer 33

C = 80-85% H = 10-14% S = 0.1-3.5% N = 0.1-0.5%

Question 34

obtained from the mine contains a lot of soluble and insoluble impurities which must be removed

Answer 34

Petroleum or crude oil

Question 35

Before it is being done by simple fractional distillation, further treatment is needed by refining.

Answer 35

Purification

Question 36

a process by which petroleum is made free of impurities

Answer 36

Refining

Question 37

Stages in the refining of petroleum

Answer 37

■ 1) removal of solid impurities ■ 2) removal of water ■ 3) removal of harmful impurities ■ 4) fractional distillation

Question 38

decomposition of larger hydrocarbon molecules to smaller molecules

Answer 38

CRACKING

Question 39

obtained from the wells dug in the earth during mining of petroleum

Answer 39

Natural gas

Question 40

mainly composed of methane and small quantities of ethane along with other hydrocarbons

Answer 40

Natural gas

Question 41

lower hydrocarbons are present

Answer 41

Dry gas or lean gas

Question 42

hydrocarbons having higher molecules are present

Answer 42

Rich or wet gas

Question 43

calorific value of natural gas

Answer 43

varies from 8000-14000 kcal/m3 .

Question 44

obtained from natural gas or as a byproduct in refineries during cracking of heavy petroleum products

Answer 44

LPG (Liquefied Petroleum Gas)

Question 45

MAIN COMPONENTS OF LPG

Answer 45

n-butane ■ isobutane ■ butylene ■ propane (traces of propene and ethane

Question 46

contains mainly methane, CH4.

Answer 46

Natural gas

Question 47

When natural gas is compressed at high pressure (1000 atm) or cooled to -160oC, it is converted to

Answer 47

CNG (Compressed Natural Gas)

Question 48

Natural gas being lead or sulfur free, its use substantially reduces harmful engine emissions.

Answer 48

CNG

Question 49

defined as the exothermic chemical reaction, which is accompanied by heat and light

Answer 49

Combustion

Question 50

the union of an element or a compound with oxygen

Answer 50

COMBUSTION

Question 51

the amount of heat required to increase the temperature of 1 gram of water one degree centigrade

Answer 51

calorie

Question 52

the unit of heat in metric system, and is defined as the quantity of heat required to raise the temperature of one kilogram of water one degree centigrade

Answer 52

■ kilocalorie

Question 53

the unit of heat in English system

Answer 53

■ British thermal unit (B.T.U.)

Question 54

defined as “the quantity of heat required to increase the temperature of one pound of water through of one degree of Fahrenheit

Answer 54

■ British thermal unit (B.T.U.) 1 B.T.U. = 252 cal = 0.252 kcal

Question 55

the quantity of heat required to raise the temperature of one pound of water one degree centigrade

Answer 55

Centigrade heat unit (C.H.U.) 1 kcal = 3.968 B.T.U. = 2.2 C.H.U.