| Oil shale is a kind of solid combustible mineral resources with relatively higher ash content, which not only can be retored to obtain shale oil, similar to natural oil, but can be used as fuel combustion directly. This paper studied on the pyrolytic properties and the characteristics of its pyrolysis products of FuShun (FS) oil shale.Some basic characteristics of oil shale showed that:FS oil shale is a kind of solid sedimentary rock with high ash (76.58%), low carbon(10.98%), high H/C atomic ratio (2.0), low oil content(6.02%) and its ash is mainly composed of SiO2, Al2O3, Fe2O3. Minerals in the oil shale are mainly existed in the form of kaolinite, montmorillonite, aluminum silicate classes by XRD analysis, by FT-IR analysis, the oil shale contains lots of minerals, the organic matter mainly exist in aliphatic hydrocarbon. The composition of shale oil is simple, mainly existed in the form of aliphatic hydrocarbon.Inspected the effects of heating rates, grain sizes, hydrogen atmosphere and ash content on the properties of the oil shale pyrolysis and the releasing characteristics of pyrolytic gas by TG-FTIR technique, the results showed that:Oil shale pyrolysis process is roughly divided into three stages, at the final temperature 800℃, the weight loss is 17.39%, pyrolytic gases mainly include CO, CO2, CH4, CnHm, aromatic hydrocarbon, and H2O, etc. With the increase of heating rate, the total conversion rate of oil shale increased slightly, so did the initial pyrolysis temperature, internal temperature and the corresponding peak temperature of maximum weight loss rate and the quantity of pyrolysis gas increased. Larger particles oil shale contains more volatile, less ash content, and high oil content, with the increase of particle size, the final conversion of oil shale increased, the release of volatile flux slightly ascending. The influence of the oil shale pyrolysis is not obvious by the addition of a small amount of hydrogen, the weightlessness increased slightly, maximum weight loss rates are almost overlap, the release of volatile flux is almost has no obvious change. After two levels of demineralization, oil shale pyrolysis was improved obviously, the final conversion of oil shale increased and the weight loss has a larger increase, the release of volatile flux also increased significantly.The research also investgatted the effect of final temperature, residence time, heating rate and carrier gas flow rate on oil shale pyrolysis by the small fixed-bed experiment device, on product yields and its characteristics. The results showed that the most significant impact on oil shale pyrolysis is final temperature, under the condition of 520℃,20 min,150 mL/min and 5℃/min, the shale oil yield was 8.69%, far higher than the oil yield of carbonization of aluminium retort, within the scope of the investigation, with the heating rate increases, the conversion rate and the oil yield increases.The characteristics of pyrolysis products with fixed bed showed that:with the increase of final pyrolysis temperature, H/C atomic ratio is falling, the content of organic matter represented by aliphatic hydrocarbon gradually reduce, and the change is no longer clear after 460℃; Compared with the original sample, the structure become more abundant after pyrilysis, the pore surface area and total pore volume is increasing, the average pore diameter is reducing; Temperature has little effect on the composition of shale oil, shale oil from different temperature are mainly aliphatic hydrocarbon; By GC-MS detection, the aliphatic hydrocarbon in shale oil is as high as 81.56%, and the majority is straight-chain alkanes. By GC detection,the pyrolysis is mainly composed of H2, CH4 and CO2, CO, C2H6, C2H4, C3H8, C3H6, H2 is the highest, CO2 and CH4 are following, in addition, to the pyrolytic gas represented a gaussian distribution apart from CO. With the increase of residence time, H/C atomic ratio is falling, the heating rate and carrier gas flow has little effect on the composition of OS-Char. |
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