Coal

Lignite

Peat

Wood

Chemical composition

Carbon (C)

weight %

76 - 87

65 - 75

50 - 60

48 - 55

Hydrogen (H)

weight %

3.5 - 5.0

4.5 - 5.5

5 - 7

6 - 7

Oxygen (O)

weight %

3 - 11

20 - 30

30 - 40

38 - 43

Nitrogen (N)

weight %

0.8 - 1.2

1 - 2

0.5 - 2.5

<0.6

Sulphur (S)

weight %

1 - 3

1 - 3

0.1 - 0.4

0.02 - 0.06

Fuel properties

Volatile matter

weight %

10 - 50

50 - 60

60 - 70

75 - 85

Ash

weight %

4 - 10

6 - 10

2 - 15

0.1 - 2.0

Bulk density

kg/m3

728 - 880

650 - 780

300 - 400

320 - 420

Effective calorific value of dry substance

MJ/kg1

28 - 33

20 - 24

20 - 23

17 - 20

1 MJ/kg = 239 Kcal/kg