Effects of Coal Liquefaction Parameters on the Removal of Oxygen and the Higher Heating Value of the Soluble Products

The Characterization of Coal Liquefaction Products Obtained under an Inert Atmosphere and Catalytic Conditions. Part II: Soluble Products

“…It could be stated that the fuel obtained by impregnation of the catalyst on coal has higher quality than the one obtained by physically mixing of catalyst to the reaction medium. As mentioned in the previous studies (Karaca et al, 2001;Karaca and Ceylan, 2002;Karaca, 2005a;Karaca, 2005b), addition of catalyst to the reaction medium after impregnation of catalyst on coal has more advantages in both total conversion and oil conversion and also in the quality of fuel obtained. In the case of both physically mixing and impregnation of catalyst to the reaction medium, it was observed that the quality of the total liquefaction products display an increase when reaction temperature was increased from 350 • C to 400 • C and a decrease above 400 • C. As mentioned previously, the quality of the fuel decrease is due to more effectiveness of pyrolysis and significant level of oxidation of liquefaction products at high temperatures.…”

“…In identification of liquefaction products, instrumental methods such as the following are used: high performance liquid chromatography (HPLC); gas chromatography (GC); gas chromatography/mass spectrometry (GC-MS); liquid chromatography/infrared spectrometry (LC-IR); mass spectrometry/mass spectrometry (MS-MS); nuclear magnetic resonance (NMR); ultraviolet visible/fluorescence spectroscopy (UV/F); size exclusion chromatography (SEC); thin-layer chromatography (TLC); and elemental analysis (Cui et al, 2003;Deelchand et al, 1999;Demirbaş, 2003;Dominguez et al, 2001;Kaplan et al, 2001;Karaca, 1998;Khan et al, 2003;Lazaro et al, 2001;Mastral et al, 2000;Sharypov et al, 2003;Singh et al, 2003;Yang et al, 2002). In the previous studies carried out on that subject (Karaca, 1998;Karaca, 2005a;Karaca, 2005b), the characterization of char, asphaltene, and oil was performed with the instrumental methods like IR, GC, elemental analysis instrument, and calorimeter bomb. In this research, the alteration of elemental analysis results of total soluble products and preasphaltenes obtained from liquefaction of the two Turkish lignites under catalytic conditions were examined by various process parameters and catalyst usage method with the elemental analysis instrument.…”

Turkey's Major Lignite Fields and Significance of Lignite for Energy Necessity

“…There are considerable studies on the liquefaction of Turkish coals (Yürüm et al, 1991;Öner et al, 1990Şimşek et al, 2001, 2002bKaraca and Ceylan, 2002;Agun et al, 2005;Karacan et al, 2005;Karaca, 2005aKaraca, , 2005bYagmur et al, 2005).…”