Classification of Coal

Question 1

although technically not a type of coal, it is the precursor to coal. it is partially decayed plant material formed in swamps and bogs

Answer 1

peat (pre-coal stage)

Question 2

carbon content of peat

Answer 2

low (30%)

Question 3

energy content of peat

Answer 3

low energy density

Question 4

uses of peat

Answer 4

in some regions, peat is harvested and used as a fuel source

Question 5

it is the lowest rank of coal with the least carbon content and energy density. it is also soft, brown, and contains high amount of moisture and volatile compounds

Answer 5

lignite (brown coal)

Question 6

carbon content of lignite

Answer 6

70% carbon

Question 7

energy content of lignite

Answer 7

low, has low heat value

Question 8

it is the most commonly used type of coal and is exposed to higher heat and pressure, making it harder, blacker, and richer in carbon, making for the steel industry

Answer 8

bituminous coal

Question 9

energy content of bituminous coal

Answer 9

high; has a higher heat value than lignite and sub-bituminous coal

Question 10

carbon content of bituminous coal

Answer 10

around 45% and 86%

Question 11

the highest rank of coal; undergone the most metamorphosis, making it hard, glossy, and very rich in carbon; burns clearly with very little smoke and produces the highest amount of energy

Answer 11

anthracite (hard coal)

Question 12

carbon content of anthracite

Answer 12

over 86% (can be as high as 98%)

Question 13

energy content of anthracite

Answer 13

very high; has the highest heating value of all coal types

Question 14

flow of formation of coal

Answer 14

peat - lignite - bituminous - anthracite