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Review

Inertinite Reflectance in Relation to Combustion Temperature

by
Di Gao
1,2,*,
Di Chen
1,
Chi Cui
1,
Xuebo Fu
1,
Junjiao Yang
1,
Shilong Zhao
1 and
Zhenzhi Wang
1
1
School of Resources and Environment, Henan Polytechnic University, Jiaozuo 454003, China
2
Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization, Jiaozuo 454003, China
*
Author to whom correspondence should be addressed.
Processes 2024, 12(11), 2452; https://doi.org/10.3390/pr12112452
Submission received: 23 September 2024 / Revised: 2 November 2024 / Accepted: 3 November 2024 / Published: 6 November 2024
(This article belongs to the Section Chemical Processes and Systems)
Browse Figures
Versions Notes

Abstract

:
Inertinite, a product of wildfire, holds important information on global temperature change. The relationship between its reflectance and temperature has been widely used to identify wildfire events in paleo-sedimentary environments, but the currently used equations relating inertinite reflectance and combustion temperature are subject to large errors. Therefore, to clarify the relationship between inertinite reflectance and combustion temperature further, we systematically analyzed changes in inertinite reflectance under different combustion durations based on the literature’s data. Results confirmed that inertinite reflectance is related to combustion duration. Disregarding combustion duration, the combustion equation is T = 267.52 + 110.19 × R o R 2 = 0.91 , where T is the combustion temperature, Ro% is the measured inertinite reflectance, and R2 is the correlation coefficient. Under a combustion duration of 1 h, the equation is T = 273.57 + 113.89 × R o R 2 = 0.91 , and under a combustion duration longer than 5 h (including 5 h), the equation is T = 232.91 + 110.6 × R o R 2 = 0.94 . These three equations not only account for the temporal factor, but are also more precise than the commonly used formula. This study provides a scientific basis for research on paleo-wildfire.

1. Introduction

Currently, Earth is experiencing climate change characterized by global warming. According to the Climate Change 2023 report released by the United Nations’ Intergovernmental Panel on Climate Change (IPCC) on 20 March 2023, the global surface temperature in 2011–2020 was 1.1 °C higher than that in 1850–1900 [1], and various types of environmental problems induced by climate change seriously threaten the environment in which we live. Wildfire is an essential component of the Earth system [2]. Wildfire events play a critical role in the Earth’s climate system, as evidenced by the release of greenhouse gases, such as CO2, CH4, NO2, and O3, during wildfire combustion, which exacerbates global warming and thus leads to global-scale climate change. Weather changes caused by wildfire activity can affect the characteristics of terrestrial vegetation and biogeochemical cycles [3], fundamentally alter local ecosystems [4,5,6,7], and promote the evolution of plants and animals [8,9,10]. In geological history, increases in wildfire frequency typically coincided with global warming [11,12]. Hence, studying interactions between paleo-wildfire events and paleoclimate can help us reconstruct climatic conditions that existed when paleo-wildfires occurred, which has significance for addressing the sixth global warming currently being experienced by Earth.
Paleo-wildfire history is mainly reconstructed based on the combustion products in strata, including charcoal, black carbon, and combustion-derived polycyclic aromatic hydrocarbons (PAHs), as well as related parameters [13]. In recent years, progressively more scholars have demonstrated experimentally that inertinites (fusinite, semifusinite, and inertodetrinite) in coal originated from wildfire activity and are equivalent to charcoal [14,15,16,17,18,19]. Fires in natural environments may be caused by many factors, such as lightning strikes, meteorite impacts, volcanic eruptions, and spontaneous combustion of vegetation, among which lightning strikes are the most common factor [20]. Based on the spatial distribution of burning materials and combustion intensity [21], wildfires can be classified into surface fires, ground fires, and crown fires [20,22]. Surface fires usually burn at a temperature below 400 °C, ground fires burn at a temperature as high as about 600 °C, and crown fires burn at a temperature of 800 °C or even higher [23] (Figure 1).
Temperature variation during combustion determines the isotopic composition, physical appearance, and chemical structure of charcoal [24,25]. Inertinite reflectance is an indicator with important information on the carbonization process, as it can be used to calculate the maximum temperature to which biochar was exposed during pyrolysis. Additionally, inertinite (charcoal) reflectance has long been applied to estimate the burning temperature of paleo-wildfires. Many studies have suggested a positive correlation between inertinite reflectance and combustion temperature [11,14,15,20,21,26], and correlation equations are available. Jones et al. investigated the relationship between the reflectance of charcoal and the maximum pyrolysis temperature for three types of plants (Picea abies, Betula pendula, and Pinus) by controlling the heating duration, the part of the plant, and other influencing factors and obtained the equation T = 198.8 R o + 237.6 R o 2 + 9.36 R o 3 R 2 = 0.98 [27]. Jones further explored the relationship between temperature and reflectance and obtained the linear relationship T = 184.10 + 117.76 × R o R 2 = 0.91 [28]. Hudspith heated wood samples of trembling aspen, dwarf birch, paper birch, black spruce, and white spruce at 300 °C to 800 °C with temperature increments of 100 °C for a duration of one hour for each temperature. The charcoals obtained were then embedded in epoxy resin and polished. Data from the five types of wood were combined to generate the following polynomial curve: T = − 6.0 × 10 − 8 R o 3 + 1.0 × 10 − 4 R o 2 − 4.4 × 10 − 2 R o + 5.9 R 2 = 0.99 [29].
However, after fitting all data regarding inertinite reflectance and combustion temperature collected from the available literature, we found that the combustion temperature of paleo-wildfires calculated using the resulting equation had a large error. In addition, because combustion duration has a significant impact on inertinite reflectance, it is necessary to construct more accurate equations between inertinite reflectance and combustion temperature by fitting data under different combustion durations so as to provide a basis for further research in related fields.
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Figure 1. Diagram of the relationship between combustion temperature and fire type (according to Petersen and Lindström, 2012 [30], with modifications). In the figure, T is the combustion temperature and Ro is the reflectance of the inert group.
Figure 1. Diagram of the relationship between combustion temperature and fire type (according to Petersen and Lindström, 2012 [30], with modifications). In the figure, T is the combustion temperature and Ro is the reflectance of the inert group.
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2. Materials and Methods

To clarify the relationship between inertinite reflectance and combustion temperature further, we collected 137 sets of data from the published literature in the SCI database and the CNKI Chinese Academic Journal Database (Table 1). The methods for obtaining charcoal reflectance mainly included muffle furnace pyrolysis and modern vegetation fire experiments [31,32,33]. Studies have shown that the charcoal produced in muffle furnaces reflects the maximum internal temperature of the charcoal produced by plant fires [34]. Therefore, we collected data from pyrolysis experiments and simulated fires for efficient analysis. These data contain inertinite (charcoal) reflectance values obtained under different combustion durations, different fuel materials, and different combustion temperatures. Studies have shown that it is inappropriate to ignore the influence of combustion duration on the relationship between inertinite reflectance and combustion temperature. Therefore, in this study, we analyzed the relationship between inertinite reflectance and combustion temperature under different combustion durations based on available data.

3. Discussion

As shown in Figure 2, combustion temperatures vary between 200 °C and 1200 °C, and reflectance varies greatly within the combustion temperature range of 500 °C to 600 °C, indicating that different sample materials exhibit significant differences in this combustion temperature interval. In contrast, Ro values are concentrated and distributed below the combustion temperature of 500 °C or above 700 °C, suggesting that the difference in reflectance between different fuel materials is minor under low combustion temperatures.
Currently, the formulas T = 198.8 R o + 237.6 R o 2 + 9.36 R o 3 R 2 = 0.98 and T = − 6.0 × 10 − 8 R o 3 + 1.0 × 10 − 4 R o 2 − 4.4 × 10 − 2 R o + 5.9 R 2 = 0.99 are not widely used in relevant fields, which limits their practical applicability and comparability. Additionally, there are significant discrepancies between data calculated using these two formulas and experimental data, making it inappropriate to present their results in the error comparison graph. Therefore, we chose empirical formulas as a reference for comparison.
Data were fitted considering the time factor, and results are shown in Figure 3. With increases in temperature and time, reflectivity data show an obvious upward trend. Based on this, we analyzed the relationship between inertinite reflectance and combustion temperature under different combustion durations based on available data.

3.1. Results Disregarding Combustion Duration

As shown in Figure 4, the relationship between temperature and inertinite reflectance fitted based on the literature data is T = 267.52 + 110.19 × R o R 2 = 0.91 . To verify the accuracy of this equation, we compared its error with that of the empirical formula T = 184.10 + 117.76 × R o R 2 = 0.91 by substituting experimental data into the empirical formula and calculating the error between the resulting combustion temperature and the actual combustion temperature.
Comparison results are plotted in Figure 5. These results show that the fitted equation has higher accuracy. When the combustion temperature is below 500 °C, the error in this equation is significantly smaller than that of the empirical formula, and this temperature level is the most commonly reached level by low-temperature surface fires. The error corresponding to the combustion temperature interval of 700 °C–900 °C is relatively higher, which may be attributable to the following reasons. First, most of the experimental samples (60% of all samples) were heated for one hour. Second, the combustion durations of samples were 1 h, 1.5 h, 5 h, and 24 h, respectively, which were significant differences in duration. Finally, only a small proportion of samples experienced a combustion temperature higher than 700 °C, and most samples were treated below 600 °C.

3.2. Results Under a Combustion Duration of 1 h

The correlation analysis results of data are shown in Figure 6. As shown, the inertinite reflectance increased significantly with increasing combustion temperature, and the relationship can be expressed as T = 273.57 + 113.89 × R o R 2 = 0.91 . The error analysis shows that the overall error value of the fitting relation was smaller than that of the empirical formula, and the error was smallest when the combustion temperature was below 500 °C (Figure 7).

3.3. Results Under a Combustion Duration Longer Than 5 h (Including 5 h)

After analyzing data with a combustion duration longer than 5 h (including 5 h), we obtained a relationship between combustion temperature and inertinite reflectance of T = 232.91 + 110.6 × R o R 2 = 0.94 (Figure 8). The results of the data analysis, as shown in Figure 9, indicate that when the combustion time greater than 5 h (including 5 h), the overall error value of the fitting relation was smaller than that of the empirical formula.
The actual carbonization temperature of plant materials can be obtained under a combustion duration exceeding 4–5 h [6], and the increasing trend of inertinite reflectance with increasing combustion temperature leveled off when the combustion duration was more than 5 h. Therefore, this equation can be used to determine the actual carbonization temperature of inertinite. As the carbonization associated with volcanic activity is characterized by a long reaction time, the relationship between combustion temperature and reflectance fitted with data obtained under a combustion duration longer than 4 h can provide qualified support for research on charcoal generated by volcanic activity.

4. Conclusions

Our results confirm the earlier work of Jones et al., showing that the reflectivity of the intertinite group increases as the combustion temperature increases. Under the condition of considering the combustion time, the fitting results of the intertinite group’s reflectivity and the combustion temperature showed obvious differences. The fitting formula was more accurate than the commonly used formula, which provides a scientific basis for the study of ancient wildfire.
(1)
The relationship between inertinite reflectance and combustion temperature disregarding combustion duration is T = 267.52 + 110.19 × R o R 2 = 0.91 . Under a combustion duration of 1 h, the equation is T = 273.57 + 113.89 × R o R 2 = 0.91 , and under a combustion duration longer than 5 h (including 5 h), it is T = 232.91 + 110.6 × R o R 2 = 0.94 .
(2)
Error analysis results show that the fitted equation expressing the relationship between inertinite reflectance and combustion temperature has a significantly lower error than the empirical formula under any combustion duration condition. The error of the fitted equation under a combustion duration of 1 h was greater than that under a combustion duration longer than 5 h (including 5 h), and the correlation coefficient (R2) between inertinite reflectance and combustion duration was also smaller, indicating that reflectance tends to stabilize as the combustion duration extends.

Author Contributions

Conceptualization, D.G.; methodology, D.G.; investigation, D.C.; resources, C.C., X.F., J.Y., S.Z. and Z.W.; data curation, D.C., C.C., X.F., J.Y., S.Z. and Z.W.; writing—original draft preparation, D.G. and D.C.; writing—review and editing, D.G., D.C., C.C., X.F., J.Y., S.Z. and Z.W.; supervision, Z.W. All authors have read and agreed to the published version of the manuscript.

Funding

This study was funded by the National Natural Science Foundation of China (No. 41402094), the Foundation of State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing (No. PRP/open-2008), and the Fundamental Research Funds for the Universities of Henan Province (No. NSFRF220411).

Data Availability Statement

Data are contained within the article.

Conflicts of Interest

The authors declare no conflicts of interest. The funders had no role in the design of this study; in the collection, analyses, or interpretation of data; in the writing of this manuscript; or in the decision to publish these results.

References

  1. Yu, Z.H. Climate change is an environmental problem as well as an economic one. In WTO Economic Guide; Beijing, China, 2018. [Google Scholar]
  2. Berner, R.A. Phanerozoic atmospheric oxygen: New results using the geocarbsulf model. Am. J. Sci. 2009, 309, 603–606. [Google Scholar] [CrossRef]
  3. Lynch, A.H.; Beringer, J.; Kershaw, P.; Marshall, A.; Mooney, S.; Tapper, N.; Turney, C.; Van Der Kaars, S. Using the paleorecord to evaluate climate and fire interactions in australia. Annu. Rev. Earth Planet. Sci. 2007, 35, 215–239. [Google Scholar] [CrossRef]
  4. van der Werf, G.R.; Randerson, J.T.; Collatz, G.J.; Giglio, L.; Kasibhatla, P.S.; Arellano Jr, A.F.; Olsen, S.C.; Kasischke, E.S. Continental-scale partitioning of fireemissions during the 1997 to 2001 El Niño/La Niña Period. Science 2004, 303, 73–76. [Google Scholar] [CrossRef] [PubMed]
  5. Gill, A.M.; Bradstock, R.A. Extinctions of biota by fires. In ConservingBiodiversity: Threats and Solutions; Bradstock, R.A., Auld, T.D., Keith, D.A., Kingsford, R., Lunney, D., Sivertsen, D., Eds.; Surrey Beatty and Sons: Sydney, Australia, 1995; pp. 309–322. [Google Scholar]
  6. Lehmann, C.E.; Anderson, T.M.; Sankaran, M.; Higgins, S.I.; Archibald, S.; Hoffmann, W.A.; Hanan, N.P.; Williams, R.J.; Fensham, R.J.; Felfili, J.; et al. Savanna vegetation-fire-climate relationships differ among continents. Science 2014, 343, 548–552. [Google Scholar] [CrossRef]
  7. Lenton, T.M. Early warning of climate tipping points. Nat. Clim. Chang. 2011, 1, 201–209. [Google Scholar] [CrossRef]
  8. Kelly, R.F.; Higuera, P.E.; Barrett, C.M.; Hu, F.S. A signal-to-noise index to quantify the potential for peak detection in sediment-charcoal records. Quat. Res. Interdiscip. J. 2011, 75, 11–17. [Google Scholar] [CrossRef]
  9. Keeley, J.E.; Rundel, P.W. Fire and the miocene expansion of C4 grasslands. Ecol. Lett. 2005, 8, 683–690. [Google Scholar] [CrossRef]
  10. Simon, M.F.; Grether, R.; de Queiroz, L.P.; Skema, C.; Pennington, R.T.; Hughes, C.E. Recent assembly of the cerrado, a neotropical plant diversity hotspot, by in situ evolution of adaptations to fire. Proc. Nat. Acad. Sci. USA 2009, 106, 20359–20364. [Google Scholar] [CrossRef]
  11. Belcher, C.M.; Hudspith, V.A. Changes to cretaceous surface fire behaviour influenced the spread of the early angiosperms. New Phytol. 2017, 213, 1521–1532. [Google Scholar] [CrossRef]
  12. Wang, Z.; Fu, X.; Pan, J.; Deng, Z. Effect of N2/CO2 injection and alternate injection on volume swelling/shrinkage strain of coal. Energy 2023, 275, 127377. [Google Scholar] [CrossRef]
  13. Zhan, C.L.; Cao, J.J.; Han, Y.M.; An, Z.S. Research Progress on Reconstruction of Paleofire History. Adv. Earth Sci. 2011, 26, 1248–1259. [Google Scholar] [CrossRef]
  14. Scott, A.C.; Glasspool, I.J. Observations and experiments on the origin and formation of inertinite group macerals. Int. J. Coal Geol. 2007, 70, 53–66. [Google Scholar] [CrossRef]
  15. Scott, A.C. Charcoal recognition, taphonomy and uses in palaeoenvironmental analysis. Palaeogeogr. Palaeoclimatol. Palaeoecol. 2010, 291, 11–39. [Google Scholar] [CrossRef]
  16. Guo, X.; Yao, J.G.; Li, H.D.; Tian, Z.; Wang, Z.; Shi, Z.; Zhao, C.; Liu, B.; Sun, Y. FTIR characteristics of charcoal with different combustion degrees as an indication of the genesis by and their significances for formation of fusinite in coal. Coal Sci. Technol. 2023, 51, 292–301. [Google Scholar] [CrossRef]
  17. Li, H.D. Implications of Modern Wildfire Residue on the Origin of Fusinite in Coal. Master’s Thesis, Hebei University of Engineering, Handan, China, 2022. [Google Scholar]
  18. Hower, J.C.; O’Keefe, J.M.; Eble, C.F. Errata: “notes on the origin of inertinite macerals in coals: Funginite associations with cutinite and suberinite” and “notes on the origin of inertinite macerals in coal: Evidence for fungal and arthropod transformations of degraded macerals”. Int. J. Coal Geol. 2013, 116–117, 182. [Google Scholar] [CrossRef]
  19. Belcher, C.M.; Collinson, M.E.; Scott, A.C. A 450-Million-Year History of Fire; Wiley-Blackwell: Hoboken, NJ, USA, 2013; pp. 229–249. [Google Scholar]
  20. Scott, A.C. The pre-quaternary history of fire. Palaeogeogr. Palaeoclimatol. Palaeoecol. 2000, 164, 281–329. [Google Scholar] [CrossRef]
  21. Scott, A.C.; Glasspool, I.J. Charcoal reflectance as a proxy for the emplacement temperature of pyroclastic flow deposits. Mater. Sci. Forum 2015, 33, 865–868. [Google Scholar] [CrossRef]
  22. Scott, A.C.; Jones, T.P. The nature and influence of fire in Carboniferous ecosystems. Palaeogeogr. Palaeoclimatol. Palaeoecol. 1994, 106, 91–112. [Google Scholar] [CrossRef]
  23. Scott, A.C. Observations on the nature and origin of fusain. Int. J. Coal Geol. 1989, 12, 443–475. [Google Scholar] [CrossRef]
  24. Antal, M.J.; Grønli, M. The art, science, and technology of charcoal production. Ind. Eng. Chem. Res. 2003, 42, 1619–1640. [Google Scholar] [CrossRef]
  25. Mcparland, L.C.; Collinson, M.E.; Scott, A.C.; Steart, D.C.; Grassineau, N.V.; Gibbons, S.J. Ferns and fires: Experimental charring of ferns compared to wood and implications for paleobiology, paleoecology, coal petrology, and isotope geochemistry. Palaios 2007, 22, 528–538. [Google Scholar]
  26. Hammes, K.; Smernik, R.J.; Skjemstad, J.O.; Herzog, A.; Schmidt, M.W.I. Synthesis and characterisation of laboratory-charred grass straw (oryza sativa) and chestnut wood (castanea sativa) as reference materials for pyom quantification. Org. Geochem. 2006, 37, 1629–1633. [Google Scholar] [CrossRef]
  27. Jones, T.P.; Scott, A.C.; Cope, M. Reflectance measurements and the temperature of formation of modern charcoals and implications for studies of fusain. Bull. Soc. Geol. Fr. 1991, 162, 193–200. [Google Scholar]
  28. Jones, T.P. Fusain in Late Jurassic Sediments from the Witch Ground Graben, North Sea, UK; Mededelingen Nederlands Instituut voor Toegepaste Geowetenschappen TNO-National Geological Survey: Haarlem, The Netherlands, 1997. [Google Scholar]
  29. Hudspith, V.A.; Belcher, C.M.; Yearsley, J.M. Charring temperatures are driven by the fuel types burned in a peatland wildfire. Front. Plant Sci. 2014, 5, 714. [Google Scholar] [CrossRef]
  30. Petersen, H.I.; Lindström, S. Synchronous Wildfire Activity Rise and Mire Deforestation at the Triassic–Jurassic Boundary. PLoS ONE 2012, 7, e47236. [Google Scholar] [CrossRef]
  31. Cuña Suárez, A.; Tancredi, N.; Pinheiro, P.C.C.; Yoshida, M.I. Thermal analysis of the combustion of charcoals from Eucalyptus dunnii obtained at different pyrolysis temperatures. J. Therm. Anal. Calorim. 2010, 100, 1051–1054. [Google Scholar] [CrossRef]
  32. Mastrolonardo, G.; Francioso, O.; Di Foggia, M.; Bonora, S.; Rumpel, C.; Certini, G. Application of thermal and spectroscopic techniques to assess fire-induced changes to soil organic matter in a Mediterranean forest. J. Geochem. Explor. 2014, 143, 174–182. [Google Scholar] [CrossRef]
  33. Merino, A.; Fonturbel, M.T.; Fernandez, C.; Chavez-Vergara, B.; Garcia-Oliva, F.; Vega, J.A. Inferring changes in soil organic matter in post-wildfire soil burn severity levels in a temperate climate. Sci. Total Environ. 2018, 627, 622–632. [Google Scholar] [CrossRef]
  34. Minatre, K.L.; Arienzo, M.M.; Moosmüller, H.; Maezumi, S.Y. Charcoal analysis for temperature reconstruction with infrared spectroscopy. Front. Earth Sci. 2024, 12, 1354080. [Google Scholar] [CrossRef]
  35. Mcparland, L.C.; Collinson, M.E.; Scott, A.C.; Campbell, G. The use of reflectance values for the interpretation of natural and anthropogenic charcoal assemblages. Archaeol. Anthropol. Sci. 2009, 1, 249–261. [Google Scholar] [CrossRef]
  36. Braadbaart, F. Morphological, chemical and physical changes during charcoalification of wood and its relevance to archaeological contexts. J. Archaeol. Sci. 2008, 35, 2434–2445. [Google Scholar] [CrossRef]
  37. Li, G.; Gao, L.; Liu, F.; Qiu, M.; Dong, G. Quantitative studies on charcoalification: Physical and chemical changes of charring wood. Fundam. Res. 2024, 4, 113–122. [Google Scholar] [CrossRef] [PubMed]
  38. Braadbaart, F.; Wright, P.J.; Van der Horst, J.; Boon, J.J. A laboratory simulation of the carbonization of sunflower achenes and seeds. J. Anal. Appl. Pyrolysis 2007, 78, 316–327. [Google Scholar] [CrossRef]
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Figure 2. Scatter plot of combustion temperature versus inertinite reflectance and data sources, produced by OriginLab Corporation. (2021). OriginPro 2021 [Computer software]. OriginLab Corporation. https://www.originlab.com. Replot based on the original paper data: Mcparland, L.C, et al., 2009 [35]; Scott, A. C. et al., 2015 [21]; Jones, T. P. et al., 1991 [27]; Scott, A. C. et al., 2007 [14]; Mcparland, L. C, et al., 2007 [25]; Hudspith, V. A, et al., 2014 [29]; Braadbaart, F. 2008 [36]; Braadbaart, F. et al., 2007 [38]; Scott, A. C. 2010 [15]; Li, Gang, et al., 2022 [37].
Figure 2. Scatter plot of combustion temperature versus inertinite reflectance and data sources, produced by OriginLab Corporation. (2021). OriginPro 2021 [Computer software]. OriginLab Corporation. https://www.originlab.com. Replot based on the original paper data: Mcparland, L.C, et al., 2009 [35]; Scott, A. C. et al., 2015 [21]; Jones, T. P. et al., 1991 [27]; Scott, A. C. et al., 2007 [14]; Mcparland, L. C, et al., 2007 [25]; Hudspith, V. A, et al., 2014 [29]; Braadbaart, F. 2008 [36]; Braadbaart, F. et al., 2007 [38]; Scott, A. C. 2010 [15]; Li, Gang, et al., 2022 [37].
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Figure 3. Trend diagram of the relationship between combustion temperature and inertinite reflectance, produced by OriginLab Corporation. (2021). OriginPro 2021 [Computer software]. OriginLab Corporation. https://www.originlab.com. The red spheres in the figure represent the data points from the transformed matrix ofexperimental data, and the surface is fitted from the matrix data. The data for >5 hours includes combustion times of 5 h,10 h, and 24 h.
Figure 3. Trend diagram of the relationship between combustion temperature and inertinite reflectance, produced by OriginLab Corporation. (2021). OriginPro 2021 [Computer software]. OriginLab Corporation. https://www.originlab.com. The red spheres in the figure represent the data points from the transformed matrix ofexperimental data, and the surface is fitted from the matrix data. The data for >5 hours includes combustion times of 5 h,10 h, and 24 h.
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Figure 4. Relationship between combustion temperature and inertinite reflectance (disregarding combustion duration).
Figure 4. Relationship between combustion temperature and inertinite reflectance (disregarding combustion duration).
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Figure 5. Comparison of inertinite reflectance changes at different combustion temperatures (disregarding combustion duration).
Figure 5. Comparison of inertinite reflectance changes at different combustion temperatures (disregarding combustion duration).
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Figure 6. Relationship between combustion temperature and inertinite reflectance (combustion time is 1 h).
Figure 6. Relationship between combustion temperature and inertinite reflectance (combustion time is 1 h).
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Figure 7. Comparison of reflectance change with combustion time of 1 h.
Figure 7. Comparison of reflectance change with combustion time of 1 h.
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Figure 8. Relationship between combustion temperature and inertinite reflectance (combustion duration longer than 5 h (including 5 h)).
Figure 8. Relationship between combustion temperature and inertinite reflectance (combustion duration longer than 5 h (including 5 h)).
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Figure 9. Comparison of reflectance changes for burning times exceeding 5 h (including 5 h).
Figure 9. Comparison of reflectance changes for burning times exceeding 5 h (including 5 h).
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Table 1. Statistical table of data sources on the relationship between combustion temperature and inert reflectivity.
Table 1. Statistical table of data sources on the relationship between combustion temperature and inert reflectivity.
Jones T. P. et al., 1991 [27]Mcparland L. C. et al., 2009 [35]Braadbaart F. et al., 2008 [36]Li Gang et al., 2022 [37]
Ro%T (°C)CRo%T (°C)CRo%T (°C)CRo%T (°C)CRo%T (°C)CRo%T (°C)CRo%T (°C)CRo%T (°C)C
0.493401.50.9530010.1330010.46300100.4031010.6540010.1725021.024001
1.394401.51.1334010.8040011.46400240.6534011.2044010.5130021.264501
3.75601.51.3337011.5850012.60500240.8737011.8850010.9035021.605001
4.56401.51.8340012.3460013.55600241.3040013.1760011.0740021.735501
5.48401.52.250013.8170014.36700241.8344014.8070011.1545022.016001
5.69201.52.556015.0580015.05800242.5050015.8990011.4350022.166501
610601.52.660016.029001///3.7060011.7044011.585502///
0.5530010.1322016.2610001///4.0965012.2150010.202504///
1.1134010.4722016.7211001///4.9670011.4344010.663004///
1.3950010.6325010.253005///6.1990013.2660010.983504///
4.360010.5825012.165005///6.24100015.9690011.124004///
4.67001///6.8411005///6.36110015.6980010.112501///
5.28201///5.058005///0.2031016.2490010.333001///
0.62701///7.22110010///0.4937016.29100010.523501///
Scott A. C. et al., 2007 [14]Scott A. C. et al., 2015 [21]Mcparland L. C. et al., 2007 [25]Scott A. C., 2010 [15]Hudspith V. A. et al., 2014 [29]Braadbaart, F. 2007 [38]
Ro%T (°C)CRo%T (°C)CRo%T (°C)CRo%T (°C)CRo%T (°C)CRo%T (°C)CRo%T (°C)C
0.1028013.9060010.25250240.2330010.4275240.65400240.463101
0.273001030011.81400240.5035010.43300241.65500241.644401
0.5532510.4735012.43450241.0340011.57400242.45600243.586001
1.0035010.8640013.68525241.1445013.33500244.4770024///
1.2440011.4745010.42300241.6250014.97600244.7380024///
1.4745011.9950011.51400242.1960016.8690024//////
2.2950012.3455013.1750024////////////
2.8155012.5960014.7360024////////////
Notes: In the table, T is temperature and C is combustion duration (hours).
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Gao, D.; Chen, D.; Cui, C.; Fu, X.; Yang, J.; Zhao, S.; Wang, Z. Inertinite Reflectance in Relation to Combustion Temperature. Processes 2024, 12, 2452. https://doi.org/10.3390/pr12112452

AMA Style

Gao D, Chen D, Cui C, Fu X, Yang J, Zhao S, Wang Z. Inertinite Reflectance in Relation to Combustion Temperature. Processes. 2024; 12(11):2452. https://doi.org/10.3390/pr12112452

Chicago/Turabian Style

Gao, Di, Di Chen, Chi Cui, Xuebo Fu, Junjiao Yang, Shilong Zhao, and Zhenzhi Wang. 2024. "Inertinite Reflectance in Relation to Combustion Temperature" Processes 12, no. 11: 2452. https://doi.org/10.3390/pr12112452

APA Style

Gao, D., Chen, D., Cui, C., Fu, X., Yang, J., Zhao, S., & Wang, Z. (2024). Inertinite Reflectance in Relation to Combustion Temperature. Processes, 12(11), 2452. https://doi.org/10.3390/pr12112452

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