Search results for "Ash layer"
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Numerical modeling and validation of hydrothermal liquefaction of a lignin particle for biocrude production
2021
Abstract Lignin liquefaction process under catalyst-free conditions in a temperature range from 573 K to 647 K is investigated with this mathematical model. Based on the theoretical understanding of the physical and chemical processes of the liquefaction process in subcritical temperatures, a comprehensive mathematical model for the decomposition of lignin by hydrolysis reaction pathway is developed on the results of a series of batch experiments. The model consists of four main sections. They are liquefaction of lignin particle, oily film, and inorganic (ash) layer formation behavior during the liquefaction, kinetic model to model further liquefaction process of initial products, and the l…
Astronomical dating of two Pliocene alkaline volcanic ash layers in the Capo Rossello area (southern Sicily, Italy): implications for the beginning o…
2009
Key-words. - Sicily Channel rift, Biostratigraphy, Astronomical calibration, Pliocene, Volcanic ash layers. Abstract. - Two volcaniclastic ash layers (AL1 and AL2) are intercalated throughout the middle Pliocene sedimentary sequences of Punta Piccola and Capo Rossello exposed along the south coast of Sicily (Italy). Astronomical calibration of the Punta Piccola section provided an age of 2.676 Ma for the deposition of the AL1 layer. The high-resolution bio-cyclostratigraphy of the Capo Rossello section, in combination with detailed correlations with previously astrono- mically calibrated coeval sequences, provided an age of 2.225 Ma for the deposition of the AL2 layer. Mineralogical, petrog…