Preparation and characterization of liquid fuel by pyrolysis of asphaltites and coal from Southeast Anotolian region

SUMMARY In this study, TGA analyses of the samples taken from solid fossil fuel in Southeast Anatolian Region were performed and the possibility of obtaining liquid fuel by pyrolysis method was investigated. In the first part of the study, the samples were taken from Silopi-Harbul, Şırnak-Avgamasya, Şırnak-Segürük veins and Diyarbakir-Hazro coal field. Particle size analyses and chemical analyses of these samples were fulfilled. In the second part, with respect to particle size termogravimetry analyses (TGA) of these samples were examined. These experiments were carried out in nonisothermal conditions and under atmospheric pressure. Determinations of how the samples weight change with the thermal energy were made on the basis of TGA curves. In the third part, liquid fuel was obtained by pyrolysis method. A fixed-bed reactor was used to flash pyrolysed small sample of asphaltites and coal under nitrogen atmosphere. The pyrolysis vapours were cooled in a series of water condensers, followed by condensation of the oils and tar in a series of cold traps, maintained at different temperatures with the aid of ice/water mixtures. Increasing the pyrolysis temperature at 600°C resulted in a large increase in the oil yield, tar, gases and H2S gases, large increase in the yield of hydrocarbon gases occurred as a result of increasing the flash pyrolysis temperature. However, particle size does not have a significant effect on the amount of oil product distribution; whereas the maximum peak temperatures increase as asphaltite particles become fine. The optimum conditions were determined by determining the amount of residual char, liquid product, water, gases and pyrolysis conversion. The influences of type of coal, particle size and temperature were examined in pyrolysis experiment. In the last part of the study, after the separation of water form the liquid product obtained by pyrolysis using first n-pentane and then toluene solvents, oil, asphaltane and preasphaltane fractions were respectively separated. The oils produced from pyrolysed of asphaltites are more complex; these products consist of complex mixtures of aliphatic, polycyclic aromatic and polar aromatic compounds containing heteroatom. Then n-pentane soluble part (oil) was treated with silicagel column chromatography. Using n-hexane, toluene and methanol the oil was respectively separated into aliphatic, aromatic and polar components.