Classification of aliphatic hydrocarbons formed at temperature-programmed co-pyrolysis of Turkish oil shales of kerogen types I and II

Temperature-programmed co-pyrolysis of Göynük and Beypazari oil shales was investigated with the aim to determine volatile product distribution and product evolution rate of co-processing, A series co-pyrolysis operation was performed using three total carbon ratios. A fixed-bed reactor was used to pyrolyse small samples of oil shale mixtures under an inert gas (argon) flow. A special sampling technique was used for collecting organic products formed at different temperature and time intervals. The co-pyrolysis products were analyzed by capillary gas chromatography and the total product evolution rate was investigated as a function of temperature and time. n-Paraffins and 1-olefins in aliphatic fraction of pyrolysis products were classified by their carbon number. In addition, the recovery of total organic carbon as an organic volatile product was determined. The effect of co-processing was determined comparing the results with the data of their separate pyrolysis. The effect of oil shale kerogen type on co-pyrolysis operation was also investigated. Conversion into volatile hydrocarbons was found to lower with increasing Beypazari oil shale share in the mixture while the amounts of C1-C15 hydrocarbons and coke to increase in the presence of this oil shale

Classification of volatile products of temperature-programmed co-pyrolysis of Turkish Soma lignite and Göynük oil shale

Temperature-programmed co-pyrolysis of Turkish Soma lignites and Göynük oil shale was investigated with the aim to determine volatile product distribution and product evolution rate of their co-processing. A fixed-bed reactor was used to pyrolyse small samples of lignite and oil shale mixture under an inert gas (argon)flow as well as special sampling technique for collecting organic products formed at different temperature and time intervals. The co-pyrolysis products were analyzed by capillary gas chromatography and the total product evolution rate was investigated as a function of temperature and time. n-Paraffins and 1-olefins in aliphatic fraction of pyrolysis products were classified by their carbon number. In addition, the recovery of total organic carbon as an organic volatile product was determined. The effect of co-processing was determined by calculating the difference between the experimental and the hypothetical mean value of conversion of total organic carbon into volatile products. Conversion of organic carbon into volatile hydrocarbons increased while the amount of carbon in solid residue decreased with increasing oil shale ratio in the lignite-shale system

Solvent swelling studies of Soma lignite (Turkey)

The volumetric swelling procedure was applied to Turkish Soma lignite using thirteen solvents to investigate the cross-linking in its macromolecular network. The theory of solvent swelling of cross-linked polymers developed by Flory and Rehner and extended by Kovac and Peppas was used to calculate number-average molecular mass per cross-link of organic structure (M¯c) in lignite samples. The results show that the volumetric solvent swelling of Soma lignite samples in non-polar and polar solvents roughly follows the regular solution theory

Effect of demineralization on yield and composition of the volatile products evolved from temperature-programmed pyrolysis of Beypazari (Turkey) Oil Shale

In this study, the effect of the mineral matter of Beypazari Oil Shale on the conversion of organic carbon of oil shale into volatile hydrocarbon, polycyclic aromatic hydrocarbons (asphaltenes, preasphaltenes) and carbon in solid residue was investigated. Kerogen was isolated by successive HCl, HNO 3 and HF treatments. A series of temperature-programmed pyrolysis operation was performed with raw Beypazari Oil Shale, and each product of every demineralization process. A carbon balance of the pyrolysis process was established by determination of the recovery of total organic carbon as organic products, and carbon remaining in the reactor because of the coking reactions. The removal of the material soluble in HCl washing affected the conversion of organic materials in the pyrolysis reactions. Alkali and alkaline earth metal cations affect the reactivity of oil shales and the leaching of these mineral matters with HCl caused a slightly decreases in the conversion to volatile hydrocarbons. The removal of pyrites with HNO3 did not affect the reactivity of the organic material in pyrolysis. But, removal of the material soluble in HF increased the conversion in pyrolysis reactions. It can be explained by the inhibitive effect of the silicate minerals. Complete removal of mineral matrix and isolation of kerogen increased the driving force for heat transfer since more heat was transferred from outside towards the inside of the oil shale particles, thus pyrolysis reaction might have occurred with ease and diffusion limitation might have decreased due to absence of mineral matrix. © 2004 Elsevier B.V. All rights reserved.Deutscher Akademischer AustauschdienstL. Ballice thanks the Department of Petroleum, Gas and Coal of the Engler-Bunte Institute, University of Karlsruhe-Germany for the use of laboratory facilities and Deutscher Akademischer Austauschdienst (DAAD) for financial support. -

A kinetic approach to the temperature-programmed pyrolysis of low- and high-density polyethylene in a fixed bed reactor: Determination of kinetic parameters for the evolution of n-paraffins and 1-olefins

The thermal degradation of both low-density polyethylene (LDPE) and high-density polyethylene (HDPE) have been investigated under non-isothermal conditions. The weight loss data have been analyzed by Flynn and Wall methods. The activation energies for overall degradation of LDPE and HDPE were determined. In addition, the recovery of carbon as 1-olefins and n-paraffins was determined by temperature-programmed pyrolysis of polyethylene. A fixed bed reactor under argon flow was used to pyrolyze small samples of LDPE and HDPE. A special gas-phase sampling technique was used to determine the composition of products eluted from the reactor as a function of temperature and time. Hydrocarbon evolution data have been analyzed by Coats-Redfern and Chen-Nuttall combinations. It must be emphasized that the evaluation of temperature-programmed pyrolysis data by combined use of Coats-Redfern and Chen-Nuttall methods provide satisfactory mathematical approaches to obtain kinetic parameters for 1-olefin and n-paraffins formation from degradation of polyethylene. Using this method, it is possible to identify every stage of pyrolysis and derive values for kinetic parameters. © 2001 Elsevier Science Ltd. All rights reserved.German Academic Exchange Service London Deutscher Akademischer Austauschdienst Deutscher Akademischer AustauschdienstThe author thanks the Department of Petroleum, Gas and Coal of the Engler-Bunte Institute, University of Karlsruhe, and German Academic Exchange Service — (Deutscher Akademischer Austauschdienst (DAAD)) for financial support. -

Co-pyrolysis of Turkish Soma lignite and Şirnak asphaltite. Analysis of co-pyrolysis products by capillary gas chromatography total stream sampling technique

Temperature-programmed co-pyrolysis of Turkish Soma lignites and Şirnak asphaltite was investigated with the aim to determine the volatile product distribution and product evolution rate of co-processing. A series co-pyrolysis operation was performed using three total carbon ratios of lignite to ashpaltite. A fixed-bed reactor was used to pyrolyse small samples of mixtures under an inert gas (argon) flow. A special sampling technique was used for collecting organic products eluted from the reactor at different temperature and time intervals. The co-pyrolysis products were analyzed by capillary gas chromatography and the total product evolution rate was investigated as a function of temperature and time. n-Paraffins and 1-olefins in aliphatic fraction of pyrolysis products were classified by their carbon number. In addition, the recovery of total organic carbon as an organic volatile product was determined. The effect of Soma lignites and Şirnak asphaltite co-processing was determined by calculating the difference between the experimental and the hypothetical mean value of conversion of total organic carbon into volatile products

Stepwise chemical demineralization of Göynük (Turkey) oil shale and pyrolysis of demineralization products

In this study, the effect of the mineral matter of Göynük oil shale on the conversion of organic carbon in kerogen into volatile hydrocarbons, polycyclic aromatic hydrocarbons (asphaltenes, preasphaltenes), and carbon in the solid residue was investigated. Kerogen was isolated by successive HCl, HNO3, and HF treatments. A series of temperature-programmed pyrolysis operations was performed with raw Göynük oil shale and each product of every demineralization process. The results show that removal of the material soluble in HCl and HNO3 slightly affected the conversion of organic materials in the pyrolysis reactions. In contrast, removal of the material soluble in HF increased the conversion in pyrolysis reactions. This behavior is explained by the inhibitive effect of the silicate minerals. The leaching of mineral matter with HCl, HNO3, and HF caused no remarkable change in the composition of volatile hydrocarbons. © 2006 American Chemical Society