A Review of Intermediate Pyrolysis as a Technology of Biomass Conversion for Coproduction of Biooil and Adsorption Biochar

Table 2

Comparison of biochar properties at different pyrolysis categories and activated carbon.

Property	Pyrolysis category			Commercially activated carbon
	Slow	Fast	Intermediate
Water content (%), wet basis	2–42 [57, 58]	3–6 [59, 60]	0.7–4 [21, 61]	1–12 [62–67]
Volatile matter (%), dry basis	7–41 [57, 58, 68–70]	11–27 [59, 60]	15–29 [21, 25]	7–21 [64–66]
Ash content (%), dry basis	1.4–9 [58, 68, 70]	8–12 [59, 60]	3–14 [19, 21, 25, 39]	2–13 [62, 64, 71]
Fixed carbon, dry basis	26–91 [57, 68–70, 72]	58–75 [59, 60]	55–65 [21, 25]	76–89 [64, 66]
pH	6–12 [58, 69, 70, 73]	7–11 [59, 73]	8–9.6 [19, 20]	5–8 [62, 64, 74]
Carbon (%), dry ash free	45–85 [57, 68, 70, 72]	63–89 [59, 75]	65–85 [19–21, 39, 61]	49–64 [66, 71]
Hydrogen (%), dry ash free	0.3–7 [57, 68, 70, 73]	0.3–4 [59, 73, 75]	0.5–4 [19, 20, 39, 61]	0.5–4.52 [66, 67]
Nitrogen (%), dry ash free	0.2–3 [57, 68, 73]	0.5–5 [59, 73, 75]	0.1–3 [19, 25, 39, 61]	0.1–2 [66, 67]
Oxygen (%), dry ash free	0.2–19 [57, 68, 73]	0.2–24 [59, 73, 75, 76]	2.2–23 [19, 20, 39, 61]	31–34 [66, 67, 71]
Average specific area (m^2/g)	0.4–370 [58, 70, 72]	15–110 [60, 77]	100–250 [19]	500–2058 [67, 74, 78–81]
Total pore volume (cm^3/g)	0.0013–0.14 [72, 82]	0.1–1 [60, 75]	0.05–0.16 [19, 25]	0.05–1.5 [64, 74, 78, 81]
H : C ratio (molar ratio)	0.02–0.61 [70, 73, 83, 84]	0.05–0.59 [85–87]	0.06–0.86 [23, 24, 88]	0.24–1.1 [89–91]
C : N ratio (molar ratio)	80–177 [73, 92]	117–180 [85–87]	73–155 [21, 23]	104–135 [67, 89]
O : C ratio (molar ratio)	0.08–0.4 [73, 84, 92]	0.05–0.18 [85–87]	0.1–0.23 [17, 23, 24, 88]	0.18–0.52 [67, 90]