Variability of Normative Properties of Wood Chips and Implications to Quality Control
Abstract
:1. Introduction
- H1—quality of wood chips produced from the same raw material type expressed by normative properties (dimensions, moisture content, and ash content) can be retained in the same quality class for six consecutive months;
- H2—ash content and gross calorific value of wood chips produced from the same raw material type can be retained for six consecutive months in ideal (repeatability and reproducibility) limits;
- H3—raw material type and debarking process significantly influences wood chips’ normative properties.
2. Materials and Methods
2.1. Data Collection
- S—debarked silver fir (Abies alba L.) and Norway spruce (Picea abies (L.) H. Karst.) energy roundwood;
- SB—silver fir (Abies alba L.) and Norway spruce (Picea abies (L.) H. Karst.) energy roundwood with bark;
- H—debarked European beech (Fagus sylvatica L.) energy roundwood;
- HB—European beech (Fagus sylvatica L.) energy roundwood with bark;
2.2. Laboratory Tests
2.3. Statistical Analyses
3. Results
3.1. Moisture Content
3.2. Ash Content
3.3. Calorific Value
3.4. Particle Size Distribution
4. Discussion
5. Conclusions
Author Contributions
Funding
Data Availability Statement
Acknowledgments
Conflicts of Interest
Appendix A. Results of the CHN(S) Analyses
Raw Material | S Fir/Spruce Energy Wood Debarked | SB Fir/Spruce Energy Wood | H Beech Energy Wood Debarked | HB Beech Energy Wood |
---|---|---|---|---|
Hydrogen content, w−% d (Deviation from HRN EN ISO 18125:2017 default values) | 6.1 (−0.1) | 5.8 (−0.4) | 5.7 (−0.5) | 5.7 (−0.5) |
Oxygen content, w−% d (Deviation from HRN EN ISO 18125:2017 default values) | 42.80 (−0.2) | 42.80 (−0.2) | 44.30 (+1.3) | 43.30 (+0.3) |
Nitrogen content, w−% d (Deviation from HRN EN ISO 18125:2017 default values) | 0.11 (+0.01) | 0.15 (+0.05) | 0.13 (+0.03) | 0.15 (+0.05) |
Sampling | 1 | 2 | 3 | 4 | 5 | 6 |
---|---|---|---|---|---|---|
Hydrogen content, w−% d (Deviation from HRN EN ISO 18125:2017 default values/Deviation from 1st sampling results) | 5.7 (−0.5/) | 6.1 (−0.1/+0.4) | 6.0 (−0.2/+0.3) | 6.0 (−0.2/+0.3) | 5.8 (−0.4/+0.1) | 5.8 (−0.4/+0.1) |
Oxygen content, w−% d (Deviation from HRN EN ISO 18125:2017 default values/Deviation from 1st sampling results) | 43.30 (+0.30/) | 43.20 (+0.20/−0.10) | 44.04 (+1.04/+0.74) | 44.34 (+1.34/+1.04) | 43.10 (+0.10/−0.20) | 42.20 (−0.80/−1.10) |
Nitrogen content, w−% d (Deviation from HRN EN ISO 18125:2017 default values/Deviation from 1st sampling results) | 0.15 (+0.05/) | 0.20 (+0.10/+0.05) | 0.16 (+0.06/+0.01) | 0.28 (+0.18/+0.13) | 0.20 (+0.10/+0.05) | 0.14 (+0.04/−0.01) |
Appendix B. Results of the ANOVA
Effect | SS | DF | MS | F | p |
---|---|---|---|---|---|
Intercept | 33375.53 | 1 | 33375.53 | 648.4461 | <0.000001 |
Wood species | 0.01 | 1 | 0.01 | 0.0002 | 0.990328 |
Debarking | 875.32 | 1 | 875.32 | 17.0065 | 0.000527 |
Wood species*Debarking | 4.82 | 1 | 4.82 | 0.0936 | 0.762846 |
Error | 1029.40 | 20 | 51.47 |
Effect | SS | DF | MS | F | p |
---|---|---|---|---|---|
Intercept | 12.11734 | 1 | 12.11734 | 616.8504 | <0.000001 |
Wood species | 0.14209 | 1 | 0.14209 | 7.2333 | 0.014098 |
Debarking | 0.37500 | 1 | 0.37500 | 19.0899 | 0.000297 |
Wood species*Debarking | 0.00000 | 1 | 0.00000 | 0.0001 | 0.992349 |
Error | 0.39288 | 20 | 0.01964 |
Effect | SS | DF | MS | F | p |
---|---|---|---|---|---|
Intercept | 9386.656 | 1 | 9386.656 | 113114.9 | <0.000001 |
Wood species | 1.589 | 1 | 1.589 | 19.1 | 0.000292 |
Debarking | 0.011 | 1 | 0.011 | 0.1 | 0.724496 |
Wood species*Debarking | 0.066 | 1 | 0.066 | 0.8 | 0.381344 |
Error | 1.660 | 20 | 0.083 |
Effect | SS | DF | MS | F | p |
---|---|---|---|---|---|
Intercept | 4336.282 | 1 | 4336.282 | 4121.941 | <0.000001 |
Wood species | 31.282 | 1 | 31.282 | 29.735 | 0.000024 |
Debarking | 0.375 | 1 | 0.375 | 0.356 | 0.557176 |
Wood species*Debarking | 1.042 | 1 | 1.042 | 0.990 | 0.331587 |
Error | 21.040 | 20 | 1.052 |
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Raw Material | S Fir/Spruce Energy Wood Debarked | SB Fir/Spruce Energy Wood | H Beech Energy Wood Debarked | HB Beech Energy Wood | |
---|---|---|---|---|---|
Average moisture content, %w 1 | 30.77 a | 43.76 b | 31.72 ab | 42.90 ab | |
Standard deviation of the moisture content, %w | ±9.67 | ±7.15 | ±5.76 | ±5.30 | |
Moisture content of the first sampling, %w (Moisture content class) | 34.6 (M35) | 47.4 (M50) | 36.6 (M40) | 45.1 (M50) | |
Deviation of the 1st sampling moisture content, %w (Moisture content class) | 2nd sampling | +2.6 (M40) | −4.5 (M45) | +0.7 (M40) | +6.1 (M55) |
3rd sampling | −4.5 (M35) | +8.7 (M55+) | −4.8 (M35) | −7.8 (M40) | |
4th sampling | −15.0 (M20) | −10.6 (M40) | −4.0 (M35) | −7.4 (M40) | |
5th sampling | −14.9(M20) | −9.8 (M40) | −6.0 (M35) | −4.0 (M45) | |
6th sampling | +9.0(M45) | −5.6 (M45) | −15.3 (M25) | 0.0 (M50) |
Raw Material | S Fir/Spruce Energy Wood Debarked | SB Fir/Spruce Energy Wood | H Beech Energy Wood Debarked | HB Beech Energy Wood | |
---|---|---|---|---|---|
Average ash content, %w 1 | 0.51 a | 0.76 bc | 0.66 ab | 0.91 c | |
Standard deviation of the ash content, %w | ±0.14 | ±0.10 | ±0.13 | ±0.18 | |
Ash content of the first sampling, %w (Moisture content class) | 0.57 (A0.7) | 0.80 (A1.0) | 0.66 (A0.7) | 0.87 (A1.0) | |
Deviation of the 1st sampling ash content, %w (Ash content class) | 2nd sampling | +0.02 (A0.7) | +0.07 (A1.0) | +0.14 (A1.0) | +0.24 (A1.5) |
3rd sampling | +0.02 (A0.7) | −0.16 (A0.7) | −0.12 (A0.7) | +0.09 (A1.0) | |
4th sampling | −0.19 (A0.5) | −0.11 (A0.7) | +0.19 (A1.0) | +0.07 (A1.0) | |
5th sampling | −0.27 (A0.5) | +0.07 (A1.0) | −0.08 (A0.7) | +0.06 (A1.0) | |
6th sampling | +0.07 (A0.7) | −0.11 (A0.7) | −0.12 (A0.7) | −0.31 (A0.7) |
Raw Material | S Fir/Spruce Energy Wood Debarked | SB Fir/Spruce Energy Wood | H Beech Energy Wood Debarked | HB Beech Energy Wood | |
---|---|---|---|---|---|
Average gross calorific value, MJ/kg 1 | 20.065 a | 20.002 a | 19.446 b | 19.593 ab | |
Standard deviation of the gross calorific value, MJ/kg | ±0.270 | ±0.337 | ±0.204 | ±0.322 | |
Gross calorific value of the first sampling, MJ/kg | 20.134 | 20.172 | 19.503 | 19.816 | |
Deviation of the 1st sampling gross calorific value, MJ/kg | 2nd sampling | −0.159 | −0.174 | −0.207 | −0.307 |
3rd sampling | −0.294 | −0.747 | −0.200 | −0.424 | |
4th sampling | −0.409 | −0.341 | −0.279 | −0.590 | |
5th sampling | +0.154 | +0.046 | +0.103 | −0.322 | |
6th sampling | +0.299 | +0.194 | +0.240 | +0.302 |
Raw material | S Fir/Spruce Energy Wood Debarked | SB Fir/Spruce Energy Wood | H Beech Energy Wood Debarked | HB Beech Energy Wood |
---|---|---|---|---|
Net calorific value based on the results of CHN(S) analyses, MJ/kg | 18.81 | 18.19 | 18.26 | 18.57 |
Net calorific value based on the HRN EN ISO 18125:2017 default values, MJ/kg (Deviation from Net calorific value based on the results of CHN(S) analyses, MJ/kg) | 18.78 (−0.03) | 18.82 (−0.09) | 18.15 (−0.11) | 18.47 (−0.10) |
Sampling | 1 | 2 | 3 | 4 | 5 | 6 |
---|---|---|---|---|---|---|
Net calorific value based on the results of CHN(S) analyses, MJ/kg | 18.57 | 18.18 | 18.08 | 17.92 | 18.23 | 18.85 |
Net calorific value based on the HRN EN ISO 18125:2017 default values, MJ/kg (Deviation from Net calorific value based on the results of CHN(S) analyses, MJ/kg) | 18.47 (−0.10) | 18.16 (−0.02) | 18.04 (−0.04) | 17.88 (−0.04) | 18.14 (−0.09) | 18.77 (−0.08) |
Net calorific value based on the 1st sampling H, O, N values, MJ/kg (Deviation from Net calorific value based on the results of CHN(S) analyses, MJ/kg) | 18.57 | 18.27 (+0.09) | 18.15 (+0.07) | 17.98 (+0.06) | 18.25 (+0.02) | 18.87 (+0.02) |
Raw Material | S Fir/Spruce Energy Wood Debarked | SB Fir/Spruce Energy Wood | H Beech Energy Wood Debarked | HB Beech Energy Wood | |
---|---|---|---|---|---|
Median value of the particle size distribution, mm 1 | 12.22 a | 12.38 a | 14.25 b | 14.92 b | |
Standard deviation of the median value of the particle size distribution, mm | ±0.86 | ±1.07 | ±0.62 | ±1.40 | |
Average share of the fine fraction, %w | 2.57 | 4.03 | 2.46 | 2.32 | |
Standard deviation of fine fraction share, %w | ±1.49 | ±1.28 | ±1.14 | ±0.59 | |
Share of the fine fraction of the first sampling, %w (Fine fraction class) | 3.66 (F05) | 4.16 (F05) | 2.17 (F05) | 1.74 (F05) | |
Deviation of the 1st sampling share of the fine fraction, %w (Fine fraction class) | 2nd sampling | +0.09 (F05) | +0.29 (F05) | +0.95 (F05) | +1.16 (F05) |
3rd sampling | +0.23 (F05) | −0.39(F05) | +1.89 (F05) | +1.20 (F05) | |
4th sampling | −2.94 (F05) | −2.38 (F05) | −0.78 (F05) | +0.94 (F05) | |
5th sampling | −2.91 (F05) | +0.12 (F05) | +0.80 (F05) | −0.12 (F05) | |
6th sampling | −1.03 (F05) | +1.54 (F10) | −1.12 (F05) | +0.30 (F05) | |
Average share of the accepts fraction, %w | 96.75 | 95.55 | 97.25 | 97.39 | |
Standard deviation of accepts fraction share, %w | ±1.16 | ±1.13 | ±1.15 | ±0.65 | |
Share of the accepts fraction of the first sampling, %w (Main fraction class) | 96.30 (P16) | 95.67 (P16) | 97.49 (P16) | 97.75 (P31S) | |
Deviation of the 1st sampling share of the accepts fraction, %w (Main fraction class) | 2nd sampling | −0.29 (P16) | −0.45 (P45) | −0.93 (P31S) | −0.85 (P31) |
3rd sampling | −0.78 (P31) | +0.05 (P31) | −1.75 (P31S) | −0.95 (P31S) | |
4th sampling | +0.80 (P45) | +1.79 (P31) | +1.02 (P31) | −0.99 (P31) | |
5th sampling | +2.54 (P31) | −0.37 (P31) | −0.88 (P31S) | +0.54 (P16) | |
6th sampling | +0.43 (P16) | −1.72 (P16) | +1.12 (P31) | +0.08 (P16) | |
Average share of the oversize fraction, %w | 0.68 | 0.42 | 0.28 | 0.30 | |
Standard deviation of oversize fraction share, %w | ±0.77 | ±0.20 | ±0.12 | ±0.20 | |
Share of the oversize fraction of the first sampling, %w | 0.04 | 0.17 | 0.34 | 0.51 | |
Deviation of the 1st sampling share of the oversize fraction, %w | 2nd sampling | +0.20 | +0.16 | −0.02 | −0.31 |
3rd sampling | +0.54 | +0.34 | −0.14 | −0.26 | |
4th sampling | +2.14 | +0.59 | −0.23 | +0.05 | |
5th sampling | +0.38 | +0.25 | +0.08 | −0.42 | |
6th sampling | +0.60 | +0.18 | +0.00 | −0.38 |
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Vusić, D.; Vujanić, F.; Pešić, K.; Šafran, B.; Jurišić, V.; Zečić, Ž. Variability of Normative Properties of Wood Chips and Implications to Quality Control. Energies 2021, 14, 3789. https://doi.org/10.3390/en14133789
Vusić D, Vujanić F, Pešić K, Šafran B, Jurišić V, Zečić Ž. Variability of Normative Properties of Wood Chips and Implications to Quality Control. Energies. 2021; 14(13):3789. https://doi.org/10.3390/en14133789
Chicago/Turabian StyleVusić, Dinko, Filip Vujanić, Karlo Pešić, Branimir Šafran, Vanja Jurišić, and Željko Zečić. 2021. "Variability of Normative Properties of Wood Chips and Implications to Quality Control" Energies 14, no. 13: 3789. https://doi.org/10.3390/en14133789
APA StyleVusić, D., Vujanić, F., Pešić, K., Šafran, B., Jurišić, V., & Zečić, Ž. (2021). Variability of Normative Properties of Wood Chips and Implications to Quality Control. Energies, 14(13), 3789. https://doi.org/10.3390/en14133789