Light Irradiation Effect Of Oil Shale

Oil shale deposit is an unconventional hydrocarbon source,which has attracted much attention in many geoscience disciplines,including petrophysics,geology,geophysics and energy engineering.Optical methods have been well used in characterizing the structural and dynamic properties of materials.Therefore,in this paper,two new optical methods are used to study the light irradiation effect and interaction mechanism of oil shale.Several terahertz methods(terahertz time domain spectroscopy,resistivity terahertz analysis and terahertz imaging technology)were used to analyze the distribution and content of organic matter in oil shale.The terahertz absorption of pyrolytic oil shale was studied.The laser induced voltage effect of oil shale and pyrolytic oil shale have been studied,and the model of the interaction between light and matter was proposed.The main research results were as follows:1.The microstructure of oil shale is explored.The structure of oil shale is studied from three aspects: the microstructure of main components of oil shale,the morphology of oil shale after pyrolysis and the crystal structure of main minerals.The surface of oil shale is rough and generally has pores and fractures.The bedding plane is tight and has good anisotropy.The size of kerogen varies greatly and its forms are diverse.Pyrite agglomerates into small spheres and crystallizes in various forms such as octahedron or pentagonal dodecahedron.After the pyrolysis of oil shale,the bedding spacing becomes larger and looser,and the structure of organic and inorganic substances changes greatly after chemical reaction.The main minerals of oil shale,such as illite and pyrite,have complete mineral structure,regular atomic arrangement and good crystallinity.2.The content of organic matter in oil shale is analyzed quantitatively.Terahertz wave response is related to the torsion and vibration of macromolecules and low-energy phenomena such as intermolecular van der Waals force.The carbon structure in kerogen is the main source of terahertz wave absorption by oil shale,and inorganic substances such as muscovite,gypsum and quartz in oil shale have little effect on terahertz absorption.The research shows that terahertz technology can be applied to detect the occurrence state of organic matter in oil shale.3.Terahertz absorption of pyrolytic oil shale was studied.The terahertz absorption and reflectivity of normal temperature oil shale are small.After heating to 600°C,the terahertz absorption coefficient of oil shale increases significantly.The terahertz reflectance of oil shale pyrolysis at 1000°C is low,and the absorption coefficient at 0.5THz is 5.5 times that of non-pyrolysis oil shale.The composition and structure tests show that magnetite and elemental iron are gradually formed during the pyrolysis of pyrite,which promotes the absorption of terahertz radiation.4.The ultraviolet pulse effect of shale oil was studied.The peak value of laser induced voltage is positively correlated with the oil content of oil shale.The laser induced voltage response can characterize the pyrolysis process of oil shale.The results show that oil shale is a mixture of organic and inorganic substances.Kerogen and minerals have different energy bands.The carrier produced by kerogen under ultraviolet laser irradiation is the reason for the laser induced voltage.