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The coupling effect of subcritical water and FeCl3 on the extraction of bulk Huadian oil shale was experimentally investigated. The results showed that, with the addition of FeCl3, the yield of shale oil in subcritical water extraction was enhanced by 58.5 % at 20 h and the time required for the maximum shale oil production was reduced by 43 %. The group compositions of shale oil and residual bitumen as well as the elemental analysis of residual kerogen revealed that FeCl3 could trigger the pyrolysis reaction networks of kerogen by promoting the cleavage of heteroatom bonds, and accelerate the decomposition of asphaltenes in residual bitumen. GC-MS analysis of n-alkanes in shale oil and residual bitumen showed that FeCl3 promoted the secondary cracking of saturated hydrocarbons in residual bitumen rather than in shale oil due to the adsorption of Fe3+ in shale matrix. The solid-state 13C NMR analysis of the residual kerogen indicated that the polycondensation of kerogen was inhibited and the ring-opening reaction of aromatic structure was promoted in the presence of FeCl3. In addition, the acidic FeCl3 solution induced the decomposition of carbonate minerals in oil shale matrix to provide additional mass transfer channels for the migration of bitumen products.

The combination of subcritical water and catalyst was proposed for oil shale extraction. The extraction of Huadian oil shale in FeCl2 solution was performed at 350 °C to evaluate the combined method. At 20 h, a high yield of bitumen 1 (the bitumen discharged from shale matrix) was obtained in FeCl2 solution with an optimal concentration of 0.08 mol/L, which was 50.5% higher than that obtained in pure water. The bitumen 1 reached a maximum yield of 18.98 wt% at 40 h in subcritical FeCl2 solution and 19.14 wt% at 70 h in subcritical water, respectively. The time needed for a maximum yield of bitumen 1 was reduced by 43% after the addition of FeCl2. The results indicated that FeCl2 played an important role in the promotion of the cleavage of hetero-atomic bonds in kerogen and the transportation of bitumen 2 (the bitumen remaining in the shale matrix) in the shale matrix. It showed the addition of FeCl2 did not significantly affect the variation trends of the relative content of the major components in bitumen 1 and bitumen 2 with the time. The subcritical FeCl2 solution extraction should be a highly efficient method for in situ extraction of oil shale.

The co-current oxidizing pyrolysis behavior of Huadian oil shale with pure oxygen at low temperature was demonstrated in this study for the first time. The characteristics of semi-coke and shale oil obtained under various pyrolysis parameters have been investigated to further clarify the mechanism of co-current oxidizing pyrolysis of oil shale. The results show that high oil recovery of 16.76 % (about 90 % compared to Fischer assay result of 18.31 %) can be achieved at 370 °C in oxidizing atmosphere. The amount of residual carbon in semi-coke was decreased by weight of 4.34 %, 6.84 % and 6.95 % at 300 °C, 350 °C and 370 °C, respectively, compared with that obtained at 520 °C in an inert atmosphere, which indicates the majority of residual carbon, rather than shale oil and shale gas, was involved in the oxidation reaction. The DSC results were an additional indication of the importance of the the oxidizing exothermic reaction of residual carbon in semi-coke, which promoted organic matter conversion at low temperatures and indicated the possibility of low-energy-consumption and therefore sustainable conversion of oil shale. Furthermore, the light fraction in the shale oil obtained in oxidizing conditions is higher than that in an inert atmosphere, which indicates oxidizing pyrolysis of oil shale can improve the quality of shale oil for further application. It is suggested that the low temperature co-current oxidizing pyrolysis could shed light on the development of a highly effective in-situ extraction strategy of oil shale.

The Cretaceous Era has always been a focus of geologic and palaeoenvironmental studies. Previous researchers believed that the impact of the global carbon cycle represents significant short-term global biogeochemical fluctuations, leading to the formation of a large number of organic rich sediments in the marine environment. During the Turonian, a large number of organic-rich oil shales were deposited in the lakes of the Songliao Basin in the Qingshankou Formation. How the depositional environment affected the formation of oil shales in continental lakes and the characteristics of these oil shales remain controversial. In this paper, through sampling of Qingshankou Formation strata, various testing methods are used to provide a variety of new data to study the characteristics of oil shales and palaeoenvironment evolution history in the Songliao Basin. The research of the sediments in the Qingshankou Formation in the Fuyu oilfield, Songliao Basin, via result analysis revealed that the oil shales possess an excellent oil-generation potential with moderate-high total organic carbon (TOC) levels (0.58–9.43%), high hydrogen index (HI) values (265–959 mg hydrocarbons (HC)/g TOC), high extractable organic matter (EOM) levels (2.50–6.96 mg/g TOC) and high hydrocarbon fractions (48–89%). The sources of the organic matter were mainly zooplankton, red algae and higher plants (including marine organisms). The aqueous palaeoenvironment of the Qingshankou Formation was a saline water environment with a high sulfate concentration, which promoted an increase in nutrients and stratification of the water density in the lake basin. Oxygen consumption in the bottom water layer promoted the accumulation and burial of high-abundance organic matter, thus forming the high-quality oil shales in the Qingshankou Formation. The global carbon cycle, warm-humid palaeoclimate, dynamic local biogeochemical cycling and relative passive tectonism were the most likely reasons for the TOC increase and negative δ13Corg deviation.

A poly(methyl methacrylate- co -methacrylate acid)/poly(ethylene glycol) [P(MMA- co -MAA)/PEG] polyblend with viscoelasticity was synthesized by a copolymerizing reaction between methyl methacrylate (MMA) and methacrylate acid (MAA) using azobisisobutyronitrile (AIBN) as initiator in poly(ethylene glycol) (PEG) methanol solution. Then, a polyblend gel electrolyte was prepared by adding KI and I 2 to P(MMA- co -MAA)/PEG system. The influence of compositions of the polyblend gel electrolyte on the ionic conductivity and the effect of temperature on photoelectronic performance of quasi-solid state dye-sensitized solar cell (QS-DSSC) were discussed. It was found that the polyblend gel electrolyte was a good candidate as high-temperature electrolyte for QS-DSSCs. Under an optimized condition, the highest conductivity of the polyblend gel electrolyte was 2.70 mS/cm 2 at 30 °C. Based on the polyblend gel electrolyte, a light-to-electricity conversion efficiency of 4.85% for QS-DSSC was achieved under AM 1.5 simulated solar light illumination at 60 °C.