Density Measurements of Gasified Coal and Synthesized Slag Melts for Next-Generation IGCC

Significance Statement

A new research conducted by Professor Hiromichi Takebe and his students Arman and Akiko Okada from Ehime University provided a calculated density of gasified coal and synthesized slag melts in silicate system with the use of Archimedean double-bob method in temperature range of 1350-1600°C. The work which was published in the journal, Fuel, was achieved with the collection of main components of gasified coal slags such as SiO2, Al2O3, CaO, MgO, FeO and Fe2O3 from an integrated gasification combined cycle IGCC plant.

The authors also carried out a chelate titration analysis on the quenched samples to envision the valence state of iron oxide Fe3+ on three samples of gasified coal slags (coal valley, Tanito Harum and Malinau) and series of various synthesized coal slag samples.

They found a certain percent variety of Fe3+ ions for both gasified and synthesized quenched samples which correlated very well with values from previous research. They also discovered a linear decrease of coal slag melt density with increasing temperature. A highest density became found in Malinau sample of the gasified coal slags as Fe2O3 and FeO contents increase but decreased with growing contents of Al2O3 and SiO2.

Similar result was also discovered in the synthesized slag melts as density also decreased linearly with an increase in temperature. Synthesized slag melts with high content of Fe2O3 had a high density but reduced with a better presence of Al2O3 contents.

The molar volumes of the synthesized slag melts of CaO-Al2O3-SiO2 CAS increases monotonically as Al2O3 contents increased. The stated molar volume values of the synthesized slag melts of CaO-Fe2O3-SiO2 CFS confirmed a discontinuous change as two regions were classified (high and low concentrations). However, values of molar volume increased due to the addition of Al2O3 and Fe2O3 in their respective silicate system of slag melts.

Coefficient of volume expansion values was also quite similar to that of the molar volumes as a monotonically elevated value was observed with increasing Al2O3 content. However, the coefficient of volume expansion values with inclusion of Fe2O3 decreases at a particular region before increasing at the next.

They also provided an empirical parameter to predict density of gasified coal slag melts based on their measured density data. The values of the average errors indicated an achieved high correlation between the measured density and the empirical composition parameter for both the gasified and synthesized slag melts.

This research offers a quantitative know-how in figuring out the chemical compositions of gasified coal slag melts coupled with their characteristic consequences on their respective synthesized final structures.

Density Measurements of Gasified Coal and Synthesized Slag Melts for Next-Generation IGCC - Advances in Engineering

The inside of the furnace for density measurements. Photo shows the Pt crucible including a slag melt with a Pt bob suspended by a Pt-13%Rh wire.

About The Author

Dr. Arman, received his doctor degree in Materials Science and Engineering from Ehime University, Japan in 2016. His doctoral thesis was focused on studies of viscosity, density, and surface tension of gasified coal and synthesized slag melts at high temperatures under the supervisor of Prof. Hiromichi Takebe. He is currently working as a lecturer at Politeknik Negeri Ujung Pandang (PNUP), Indonesia.

About The Author

Prof. Hiromichi Takebe is a full professor in Materials Science and Engineering at the Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Japan. His current interests include high-temperature properties of slag melt, sustainable non-ferrous metallurgy, properties and structure of advanced glasses with new functionalities for biomedical, nuclear waste, energy, and optical applications.

About The Author

Ms. Akiko Okada was a master course student in Materials Science and Engineering, Graduate School of Science and Engineering, Ehime University, Japan from April, 2014 to March, 2016. She had studied density and surface tension of gasified coal and synthesized slag melts at high temperatures under the supervisor of Prof. Hiromichi Takebe.

Journal Reference

Arman1,2, A. Okada1, H. Takebe1, Density measurements of gasified coal and synthesized slag melts for next-generation IGCC, Fuel 182 (2016) 304–313.

Show Affiliations
  1. Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan.
  2. Department of Mechanical Engineering, State Polytechnic of Ujung Pandang, Jl. Perintis Kemerdekaan km. 10, Tamalanrea, 90245 Makassar, Indonesia.

 

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