H

(wt%)

C

(wt%)

N

(wt%)

Ash

(wt%)

Carbon yield (%)

Unheated kelp holdfast

4.4

31

1.6

5.5

―

600˚C (Carbonized)

1.2

41

1.3

13

55

900˚C (Carbonized)

1.7

66

2.5

8.6

41

600˚C (50% ZnCl₂),

Unwashed

1.8

29

0.91

14

―

600˚C (50% ZnCl₂)

1.4

78

3.5

1.7

68

600˚C (75% ZnCl₂)

1.4

78

3.7

0.11

54

900˚C (50% ZnCl₂)

0.66

79

2.9

4.2

67