@article{hommel_continuous_2022,

title = {Continuous measurement of K and S release by means of ETV-ICP OES for high-temperature coal conversion processes},

author = {Caroline Hommel and Marcel Laabs and Thomas Vogt and Carla Vogt and Stefan Guhl and Bernd Meyer},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0016236122001612},

doi = {10.1016/j.fuel.2022.123292},

issn = {00162361},

year  = {2022},

date = {2022-05-01},

urldate = {2022-05-01},

journal = {Fuel},

volume = {316},

pages = {123292},

abstract = {To estimate the fouling, slagging and corrosion potential of an energy feedstock during thermal carbon conversion processes, it is necessary to determine the temperature-dependent release behavior of relevant elements such as potassium and sulfur. For this purpose, this study employed electrothermal evaporation with inductively coupled plasma and optical emission spectroscopy (ETV-ICP OES) to investigate the element release in atmospheres containing oxygen both qualitatively and quantitatively. Using three different coal samples, it is shown that different heating rates (5–350 K/s) and gas atmospheres (0–10 vol-% O2 in the Ar gas stream) lead to differences in the release behavior. More sulfur is released when the oxygen content increases, whatever the sample. The release of potassium, on the other hand, depends on the sample matrix and the secondary reactions that occur. In two of the samples investigated, K is bound to silicates. These samples tend to form slags in which the potassium can bind. In the third sample, the potassium is organically bound or is bound to exchange sites on clay minerals and is released almost completely during the analyses.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{reinmoller_methods_2022,

title = {Methods for the determination of composition, mineral phases, and process-relevant behavior of ashes and its modeling: A case study for an alkali-rich ash},

author = {Markus Reinmöller and Lingxue Kong and Marcel Laabs and Zefeng Ge and Caroline Hommel and Massoud Massoudi Farid and Wenju Shi and Marcus Schreiner and Xi Cao and Stefan Guhl and Jin Bai and Bernd Meyer},

url = {https://linkinghub.elsevier.com/retrieve/pii/S1743967121001926},

doi = {10.1016/j.joei.2021.11.001},

issn = {17439671},

year  = {2022},

date = {2022-02-01},

urldate = {2022-02-01},

journal = {Journal of the Energy Institute},

volume = {100},

pages = {137–147},

abstract = {The mineral matter contained in feedstocks has a generally limiting impact on the process design of high-temperature conversion processes. In the present study, the composition, mineral phases, and process-relevant properties of ashes are investigated by different experimental and modeling methods, which were reviewed in the literature regarding the frequently applied methods. Various analyses are exemplarily performed for the ashes of a high-sodium coal from China, generated at temperatures of 150–950 °C. X-ray fluorescence (XRF) analysis, microwave-assisted inductively-coupled plasma optical emission spectrometry (MW-ICP-OES), and the same technique with electrothermal vaporization (ETV-ICP-OES) are applied to analyze the chemical composition of the bulk material. The chemical composition of the near-surface region is studied by scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). Mineral phases are analyzed by X-ray diffraction (XRD) and thermochemical calculations. The process-relevant ash fusion behavior is studied by a common ash fusion test (AFT) and thermomechanical analysis (TMA) and supported by thermochemical calculations. The different ashing temperatures have a recognizable impact on the composition, formation and transformation of mineral phases, and resulting ash fusion behavior, while each property is monitored by at least two different methods. For this purpose, a detailed analysis of the results achieved by the individual methods is performed. Finally, the results obtained by different methods for the same ash property are compared for monitoring the validity of the results and, for example, extracting additional information about the gas phase transfer of selected ash components.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{hommel_fast_2021,

title = {A fast and robust direct solid sampling method for the determination of 27 trace, main and minor elements in soda-lime glass based on ETV-ICP OES and using a gaseous halogenating modifier},

author = {C. Hommel and J. Hassler and R. Matschat and T. Vogt and A. K. Detcheva and S. Recknagel},

url = {https://xlink.rsc.org/?DOI=D1JA00081K},

doi = {10.1039/D1JA00081K},

issn = {0267-9477, 1364-5544},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {Journal of Analytical Atomic Spectrometry},

volume = {36},

number = {8},

pages = {1683–1693},

abstract = {A method, based on electrothermal vaporization (ETV) coupled to inductively coupled plasma optical emission spectrometry (ICP OES), has been optimized for direct solid sampling analysis of soda-lime glass—the most common type of industrially manufactured glass. This method allows fast and reliable quantification of the main elements—Al, Ca, K, Mg, Na, and Si—and trace elements—As, Ba, Cd, Ce, Co, Cr, Cu, Fe, Mn, Mo, Ni, (P), Pb, Sb, (Se), Sn, Sr, Ti, V, Zn, and Zr. In the presented ETV-ICP OES method, calibration is performed predominantly with matrix-free synthetic samples. This metrological advantage is normally not achieved with direct solid sampling methods and is one of the goals of the present study. In a certification interlaboratory comparison for the soda-lime glass CRM BAM-S005c, 2 out of 16 laboratories employed the ETV-ICP OES method. An improved analytical performance was obtained compared with the results of laboratories that used conventional liquid ICP OES. For both methods, the average relative deviations between the laboratory results and certified values as well as the average values of relative standard deviation were with a few exceptions <10%, in most cases even <5%, which indicated high trueness and precision. The limits of quantification of the trace elements by ETV-ICP OES were mostly <3 mg kg−1. Low subsample masses of 0.2–0.6 mg were used to avoid matrix effects. The optimized conditions consist of using CHF3 as a modifier gas at a flow rate of 2.3 mL min−1, an ETV temperature program with a final temperature of 2530 °C, and use of graphite grit material in combination with a sample boat with a hemispherical cavity for the optimal release of the analytes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}