1 Introduction
2 Materials and methods
2.1 Pellets and briquettes production
2.2 Pellets and briquettes characterization
Characteristic | Unit | Reference standard |
---|---|---|
Moisture content | w-% as received, wet basis | EN ISO 18134-1a,b (2017) |
Diameter and length | mm | EN ISO 17829a (2015) |
EN ISO 17225-3b (2014) | ||
Bulk density Particle density | kg m−3as received | EN ISO 17828a (2015) |
EN ISO 18847b (2016) | ||
Durability | % as received | EN ISO 17831a,b (2015) |
Ash content | w-% dry | EN ISO 18122a,b (2017) |
Net calorific value | MJ kg−1 as received | EN ISO 18125a,b (2018) |
Ash melting behaviour | °C | EN ISO 21404a,b (2020) |
Elemental analysis | w-% dry | EN ISO 16948a,b (2015) EN ISO 16994a,b (2016) |
mg kg−1 dry | EN ISO 16968a,b (2015) |
3 Results and discussion
3.1 Pellets characterization
Characteristic | Class | Measured value | Reference values of EN ISO 17225-2: 2014 | ||
---|---|---|---|---|---|
A1 | A2 | B | |||
Moisture content (M) | M10 | 10% as received | M10 ≤ 10 | ||
Diameter (D) | D06 | 6.0 mm | D06.6 ± 1 D08.8 ± 1 | ||
Length (L) | 13.5 mm | 3.15 < L ≤ 40 | |||
Bulk density (BD) | BD650 | 650 kg m−3 as received | BD600 ≥ 600 | ||
Durability (DU) | DU95.0 | 95.8% | DU97.5 ≥ 97.5 | DU97.5 ≥ 97.5 | DU96.5 ≥ 96.5 |
Ash (A) | A0.5 | 0.4% dry | A0.7 ≤ 0.7 | A1.2 ≤ 1.2 | A2.0 ≤ 2.0 |
Net calorific value (pciM) | – | 16.5 MJ kg−1 | Q 16.5 ≥ 16.5 | ||
Ash melting behaviour | SST | 1200 °C | Indicate temperature | ||
DT | 1380 °C | ||||
HT | 1460 °C | ||||
FT | 1470 °C |
Elements | Unit | Measured value | Reference values of EN ISO 17225-2: 2014 | ||
---|---|---|---|---|---|
A1 | A2 | B | |||
Nitrogen, N | % dry | 0.1 | N0.3 ≤ 0.3 | N0.5 ≤ 0.5 | N1.0 ≤ 1.0 |
Sulfur, S | % dry | 0.01 | S0.04 ≤ 0.04 | S0.05 ≤ 0.05 | S0.05 ≤ 0.05 |
Chlorine, Cl | % dry | 0.02 | Cl0.02 ≤ 0.02 | Cl0.02 ≤ 0.02 | Cl0.03 ≤ 0.03 |
Arsenic, As | mg kg−1 dry | < 0.7 | ≤ 1 | ||
Cadmium, Cd | mg kg−1 dry | 0.1 | ≤ 0.5 | ||
Chrome, Cr | mg kg−1 dry | 1.0 | ≤ 10 | ||
Copper, Cu | mg kg−1 dry | 1.2 | ≤ 10 | ||
Mercury, Hg | mg kg−1 dry | < 0.1 | ≤ 0.1 | ||
Lead, Pb | mg kg−1 dry | 0.6 | ≤ 10 | ||
Nickel, Ni | mg kg−1 dry | 0.6 | ≤ 10 | ||
Zinc, Zn | mg kg−1 dry | 11.6 | ≤ 100 |
3.2 Briquettes characterization
Characteristic | Class | Measured value | Reference values of EN ISO 17225-3: 2014 | ||
---|---|---|---|---|---|
A1 | A2 | B | |||
Moisture content (M) | M12 | 10.7% as received | M12 ≤ 12 | M15 ≤ 15 | M15 ≤ 15 |
Diameter (D) | 50.0 mm | Indicate diameter, width and length | |||
Length (L) | 321.7 mm | ||||
Density (DE) | DE 1.0 | 1.2 g cm−3 as received | DE1.0 ≥ 1.0 | DE0.9 ≥ 0.9 | DE0.9 ≥ 0.9 |
Mechanical durability (DU) | DU95.0 | 99.0% | Indicate value | ||
Ash (A) | A1.0 | 0.7% dry | A1.0 ≤ 1.0 | A1.5 ≤ 1.5 | A3.0 ≤ 3.0 |
Net calorific value (pciM) | – | 17.1 MJ kg−1 | Q 15.5 ≥ 15.5 | Q 15.3 ≥ 15.3 | Q 14.9 ≥ 14.9 |
Ash melting behaviour | SST | 1210 °C | Indicate temperature | ||
DT | 1330 °C | ||||
HT | 1440 °C | ||||
FT | 1480 °C |
Elements | Unit | Measured value | Reference values (EN ISO 17225-2: 2014) | ||
---|---|---|---|---|---|
A1 | A2 | B | |||
Nitrogen, N | % dry | 0.2 | N0.3 ≤ 0.3 | N0.5 ≤ 0.5 | N1.0 ≤ 1.0 |
Sulfur, S | % dry | 0.01 | S0.04 ≤ 0.04 | S0.05 ≤ 0.05 | S0.05 ≤ 0.05 |
Chlorine, Cl | % dry | 0.01 | Cl0.02 ≤ 0.02 | Cl0.02 ≤ 0.02 | Cl0.03 ≤ 0.03 |
Arsenic, As | mg kg−1 dry | < 0.3 | ≤ 1 | ||
Cadmium, Cd | mg kg−1 dry | 0.1 | ≤ 0.5 | ||
Chrome, Cr | mg kg−1 dry | 0.8 | ≤ 10 | ||
Copper, Cu | mg kg−1 dry | 5.7 | ≤ 10 | ||
Mercury, Hg | mg kg−1 dry | < 0.07 | ≤ 0.1 | ||
Lead, Pb | mg kg−1 dry | 0.6 | ≤ 10 | ||
Nickel, Ni | mg kg−1 dry | 0.6 | ≤ 10 | ||
Zinc, Zn | mg kg−1 dry | 18.3 | ≤ 100 |
Pellets | Briquettes | ||||
---|---|---|---|---|---|
Biomass origin | Wood, agriculture, forest waste, wood industrial waste | Wood, agriculture, forest waste, wood industrial waste | |||
Typical moisture content (%) | 10–15 | 10–20 | |||
Typical particle size (mm) | < 3 | 6–12 | |||
Addition of binder | Not request | Not request | |||
Typical shape | Cylindrical | Cylindrical | |||
Densification system | Pellet mill | Briquette press | |||
Piston press | Screw press | Roller press | |||
Mechanical | Hydraulic | ||||
Unit densities (g cm−3) | 1.1–1–2 | > 1 | < 1 | 1–1.4 | n.a. |
Energy consumption (kW ton−1) | 15–40 | n.a. | 37–77 | 37–150 | 30–83 |
Production capacity (ton h−1) | 2.5–5 | 0.2–2.5 | 0.05–0.4 | 0.5–1 | 5–10 |
Maintenance | Low | High | Low | Low | |
Output from machine | Continuous | In strokes | Continuous | Continuous |