@article{2-s2.0-85168546328,

title = {Interlaboratory study: Testing reproducibility of solid biofuels component identification using reflected light microscopy},

author = { A. Drobniak and M. Mastalerz and Z. Jelonek and I. Jelonek and T. Adsul and N.M. Andolšek and O.H. Ardakani and T. Congo and B. Demberelsuren and B.S. Donohoe and A. Douds and D. Flores and R. Ganzorig and S. Ghosh and A.P. Giże and P.A. Gonçalves and P.C. Hackley and J.J. Hatcherian and J.C. Hower and S. Kalaitzidis and S. Kędzior and W.R. Knowles and J. Kus and K. Lis and G.P. Lis and Be. Liu and Q. Luo and M. Du and D.K. Mishra and M. Misz-Kennan and T. Mugerwa and J.L. Nedzweckas and J.M.K. O'Keefe and Ja. Park and R. Pearson and H.I. Petersen and J. Reyes and J. Ribeiro and G. de la Rosa-Rodríguez and P. Sosnowski and B.J. Valentine and A.K. Varma and M. Wojtaszek-Kalaitzidi and Zh. Xu and A. Zdravkov and K. Ziemianin},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85168546328&doi=10.1016%2fj.coal.2023.104331&partnerID=40&md5=437705b071d6453eaaf41d2816f52333},

doi = {10.1016/j.coal.2023.104331},

issn = {01665162},

year  = {2023},

date = {2023-01-01},

journal = {International Journal of Coal Geology},

volume = {277},

publisher = {Elsevier B.V.},

abstract = {Considering global market trends and concerns about climate change and sustainability, increased biomass use for energy is expected to continue. As more diverse materials are being utilized to manufacture solid biomass fuels, it is critical to implement quality assessment methods to analyze these fuels thoroughly. One such method is reflected light microscopy (RLM), which has the potential to complement and enhance current standard testing, leading to improving fuel quality assessment and, ultimately, preventing avoidable air pollution. An interlaboratory study (ILS) was conducted to test the reproducibility of biomass fuels component identification using a reflected light microscopy technique. The exercise was conducted on thirty photomicrographs showing biomass and various undesired components (like plastics or mineral matter), which were purposely added (by the ILS organizers) to contaminate wood pellets and charcoal-based grilling fuels. Forty-six participants had various levels of difficulty identifying the marked components, and as a result, the percentage of correct answers ranged from 52.2 to 94.4%. Among the most difficult components to distinguish were petroleum products and inorganic matter. Various reasons led to the misidentification, including insufficient morphological descriptions of the components provided to participants, ambiguities of the nomenclature, limitations of the analytical and exercise method, and insufficient experience of the participants. Overall, the results indicate that RLM has the potential to enhance the quality assessment of biomass fuels. However, they also demonstrate that the petrographic classification used in this exercise requires further refinement before it can be standardized. While a new simplified classification of solid biomass fuels components was created as an outcome of this study, future research is necessary to refine the nomenclature, develop a microscopic morphological description of the components, and verify the accuracy of component identification with a follow-up ILS. © 2023 Elsevier B.V.},

note = {2},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85077470990,

title = {Testing reproducibility of vitrinite and solid bitumen reflectance measurements in North American unconventional source-rock reservoir petroleum systems},

author = { P.C. Hackley and C.V. Araujo and A.G. Borrego and A. Bouzinos and B.J. Cardott and H. Carvajal-Ortiz and M.R. López Cely and V. Chabalala and P.J. Crosdale and T.D. Demchuk and C.F. Eble and D. Flores and A. Furmann and T. Gentzis and P.A. Gonçalves and C. Guvad and M. Hámor-Vidó and I. Jelonek and M.N. Johnston and T. Juliao-Lemus and S. Kalaitzidis and W.R. Knowles and J. Kus and Z. Li and G. Macleod and M. Mastalerz and T.R. Menezes and S. Ocubalidet and R. Orban and W. Pickel and P. Ranasinghe and J. Ribeiro and O.P. Gómez Rojas and R. Ruiz-Monroy and J.S. Schmidt and A. Seyedolali and G. Siavalas and I. Suárez-Ruiz and C.V. Vargas and B.J. Valentine and N.J. Wagner and B. Wrolson and J.E. Jaramillo Zapata},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85077470990&doi=10.1016%2fj.marpetgeo.2019.104172&partnerID=40&md5=54b9bdcba5174f1fcac4c519faae175a},

doi = {10.1016/j.marpetgeo.2019.104172},

issn = {02648172},

year  = {2020},

date = {2020-01-01},

journal = {Marine and Petroleum Geology},

volume = {114},

publisher = {Elsevier Ltd},

abstract = {An interlaboratory study (ILS) was conducted to test reproducibility of vitrinite and solid bitumen reflectance measurements in six mudrock samples from United States unconventional source-rock reservoir petroleum systems. Samples selected from the Marcellus, Haynesville, Eagle Ford, Barnett, Bakken and Woodford are representative of resource plays currently under exploitation in North America. All samples are from marine depositional environments, are thermally mature (Tmax >445 °C) and have moderate to high organic matter content (2.9–11.6 wt% TOC). Their organic matter is dominated by solid bitumen, which contains intraparticle nano-porosity. Visual evaluation of organic nano-porosity (pore sizes < 100 nm) via SEM suggests that intraparticle organic nano-pores are most abundant in dry gas maturity samples and less abundant at lower wet gas/condensate and peak oil maturities. Samples were distributed to ILS participants in forty laboratories in the Americas, Europe, Africa and Australia; thirty-seven independent sets of results were received. Mean vitrinite reflectance (VRo) values from all ILS participants range from 0.90 to 1.83% whereas mean solid bitumen reflectance (BRo) values range from 0.85 to 2.04% (no outlying values excluded), confirming the thermally mature nature of all six samples. Using multiple statistical approaches to eliminate outlying values, we evaluated reproducibility limit R, the maximum difference between valid mean reflectance results obtained on the same sample by different operators in different laboratories using different instruments. Removal of outlying values where the individual signed multiple of standard deviation was >1.0 produced lowest R values, generally ≤0.5% (absolute reflectance), similar to a prior ILS for similar samples. Other traditional approaches to outlier removal (outside mean ± 1.5*interquartile range and outside F10 to F90 percentile range) also produced similar R values. Standard deviation values < 0.15*(VRo or BRo) reduce R and should be a requirement of dispersed organic matter reflectance analysis. After outlier removal, R values were 0.1%–0.2% for peak oil thermal maturity, about 0.3% for wet gas/condensate maturity and 0.4%–0.5% for dry gas maturity. That is, these R values represent the uncertainty (in absolute reflectance) that users of vitrinite and solid bitumen reflectance data should assign to any one individual reported mean reflectance value from a similar thermal maturity mudrock sample. R values of this magnitude indicate a need for further standardization of reflectance measurement of dispersed organic matter. Furthermore, these R values quantify realistic interlaboratory measurement dispersion for a difficult but critically important analytical technique necessary for thermal maturity determination in the source-rock reservoirs of unconventional petroleum systems. © 2019},

note = {14},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84906222841,

title = {Standardization of reflectance measurements in dispersed organic matter: Results of an exercise to improve interlaboratory agreement},

author = { P.C. Hackley and C.V. Araujo and A.G. Borrego and A. Bouzinos and B.J. Cardott and A.C. Cook and C.F. Eble and D. Flores and T. Gentzis and P.A. Gonçalves and J.G. Mendonça Filho and M. Hámor-Vidó and I. Jelonek and K. Kommeren and W.R. Knowles and J. Kus and M. Mastalerz and T.R. Menezes and J. Newman and I.K. Oikonomopoulos and M. Pawlewicz and W. Pickel and J. Potter and P. Ranasinghe and H. Read and J. Reyes and G.D.L. Rosa Rodriguez and I.V. Alves Fernandes de Souza and I. Suárez-Ruiz and I. Sýkorová and B.J. Valentine},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84906222841&doi=10.1016%2fj.marpetgeo.2014.07.015&partnerID=40&md5=706065637b6795157db0f7458b850d09},

doi = {10.1016/j.marpetgeo.2014.07.015},

issn = {02648172},

year  = {2015},

date = {2015-01-01},

journal = {Marine and Petroleum Geology},

volume = {59},

pages = {22-34},

publisher = {Elsevier Ltd},

abstract = {Vitrinite reflectance generally is considered the most robust thermal maturity parameter available for application to hydrocarbon exploration and petroleum system evaluation. However, until 2011 there was no standardized methodology available to provide guidelines for vitrinite reflectance measurements in shale. Efforts to correct this deficiency resulted in publication of ASTM D7708: Standard test method for microscopical determination of the reflectance of vitrinite dispersed in sedimentary rocks. In 2012-2013, an interlaboratory exercise was conducted to establish precision limits for the D7708 measurement technique. Six samples, representing a wide variety of shale, were tested in duplicate by 28 analysts in 22 laboratories from 14 countries. Samples ranged from immature to overmature (0.31-1.53% Ro), from organic-lean to organic-rich (1-22wt.% total organic carbon), and contained Type I (lacustrine), Type II (marine), and Type III (terrestrial) kerogens. Repeatability limits (maximum difference between valid repetitive results from same operator; same conditions) ranged from 0.03 to 0.11% absolute reflectance, whereas reproducibility limits (maximum difference between valid results obtained on same test material by different operators; different laboratories) ranged from 0.12 to 0.54% absolute reflectance. Repeatability and reproducibility limits degraded consistently with increasing maturity and decreasing organic content. However, samples with terrestrial kerogens (Type III) fell off this trend, showing improved levels of reproducibility due to higher vitrinite content and improved ease of identification. Operators did not consistently meet the reporting requirements of the test method, indicating that a common reporting template is required to improve data quality. The most difficult problem encountered was the petrographic distinction of solid bitumens and low-reflecting inert macerals from vitrinite when vitrinite occurred with reflectance ranges overlapping the other components. Discussion among participants suggested this problem could not be easily corrected via kerogen concentration or solvent extraction and is related to operator training and background. No statistical difference in mean reflectance was identified between participants reporting bitumen reflectance vs. vitrinite reflectance vs. a mixture of bitumen and vitrinite reflectance values, suggesting empirical conversion schemes should be treated with caution. Analysis of reproducibility limits obtained during this exercise in comparison to reproducibility limits from historical interlaboratory exercises suggests use of a common methodology (D7708) improves interlaboratory precision. Future work will investigate opportunities to improve reproducibility in high maturity, organic-lean shale varieties. © 2014 Elsevier Ltd.},

note = {121},

keywords = {},

pubstate = {published},

tppubtype = {article}

}