53 research outputs found

    Reaction characteristics of waste coffee grounds chemical-looping gasification

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    Coffee grounds in chemical-looping gasification is an innovative handling approach of waste coffee grounds which couple the coffee grounds gasification and chemical looping technology together. By sol-gel method, the Fe4ATP6K1 compound oxygen carrier (OC) modified by KNO3 were prepared with Fe2O3 as an active component, natural attapugite (ATP) as an inert support. The effects of reaction temperature, steam flow as well as O/C molar ratio on coffee grounds in chemical looping gasification (CLG) were investigated in a fluidized bed using steam as gasification agent. It indicated that the Fe4ATP6K1 oxygen carrier could enhance the conversion of coffee grounds. Compared with SiO2 as bed material, the carbon conversion increased in CLG from 71.38% to 86.25%. The optimized conditions were presented as follows: the reaction temperature was 900°C, the water flow was 0.23 g·min-1, the O/C molar ratio was 1. Under these conditions, it was found that the average concentration of H2 reached a maximum value 52.75%, with the syngas production of 1.30 m3·kg-1 and H2 production of 83.79 g·kg-1, respectively. 20 redox cycles demonstrated that the Fe4ATP6K1 oxygen carrier has an excellent cyclic stability, the carbon conversion and cold gas efficiency were both above 75%, while the average gas concentration of gases were nearly stable

    Does metal pollution matter with C retention by rice soil?

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    Date of Acceptance: 17/07/2015 The research work was supported by the China Natural Science Foundation under a grant number of 40830528 and of 40671180. P.S. is a Royal Scoiety-Wolfson Research Merit Award holder and was supported by additional travel funds from a UK BBSRC China Partnership Award. P.S.’s contribution was supported by the UK-China Sustainable Agriculture Innovation Network (SAIN). D.C. was supported by an additional travel and collaboration funding from the China Ministry of Education under a “111” project.Peer reviewedPublisher PD

    Sr1-xKxFeO3 Perovskite Catalysts with Enhanced RWGS Reactivity for CO2 Hydrogenation to Light Olefins

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    The catalytic hydrogenation of CO2 to light olefins (C2–C4) is among the most practical approaches to CO2 utilization as an essential industrial feedstock. To achieve a highly dispersed active site and enhance the reactivity of the reverse water–gas shift (RWGS) reaction, ABO3-type perovskite catalysts Sr1-xKxFeO3 with favorable thermal stability and redox activity are reported in this work. The role of K-substitution in the structure–performance relationship of the catalysts was investigated. It indicated that K-substitution expedited the oxygen-releasing process of the SrFeO3 and facilitated the synchronous formation of active-phase Fe3O4 for the reverse water–gas shift (RWGS) reaction and Fe5C2 for the Fischer–Tropsch synthesis (FTS). At the optimal substitution amount, the conversion of CO2 and the selectivity of light olefins achieved 30.82% and 29.61%, respectively. Moreover, the selectivity of CO was up to 45.57% even when H2/CO2=4 due to CO2-splitting reactions over the reduced Sr2Fe2O5. In addition, the reversibility of perovskite catalysts ensured the high dispersion of the active-phase Fe3O4 and Fe5C2 in the SrCO3 phase. As the rate-determining step of the CO2 hydrogenation reaction to light olefins over Sr1-xKxFeO3 perovskite catalysts, FTS should be further tailored by partial substitution of the B site. In sum, the perovskite-derived catalyst investigated in this work provided a new idea for the rational design of a catalyst for CO2 hydrogenation to produce light olefins

    Genetic Diversity and Population Structure of Bermudagrass [Cynodon dactylon (L.) Pers.] along Latitudinal Gradients and the Relationship with Polyploidy Level

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    Understanding the population genetic pattern and process of gene flow requires a detailed knowledge of how landscape characteristics structure populations. Although Cynodon dactylon (L.) Pers. (common bermudagrass) is widely distributed in the world, information on its genetic pattern and population structure along latitudinal gradients is limited. We tried to estimate the genetic diversity and genetic structure of C. dactylon along a latitudinal gradient across China. Genetic diversity among different ploidy levels was also compared in the study. The material used consisted of 296 C. dactylon individuals sampled from 16 geographic sites from 22°35′ N to 36°18′ N. Genetic diversity was estimated using 153 expressed sequence tag-derived simple sequence repeat (EST-SSR) loci. Higher within-population genetic diversity appeared at low-latitude, as well as having positive correlation with temperature and precipitation. The genetic diversity increased with the ploidy level of C. dactylon, suggesting polyploidy creates higher genetic diversity. No isolation by distance and notable admixture structure existed among populations along latitudes. Both seed dispersal (or vegetative organs) and extrinsic pollen played important roles for gene flow in shaping the spatial admixture population structure of C. dactylon along latitudes. In addition, populations were separated into three clusters according to ploidy levels. C. dactylon has many such biological characters of perennial growth, wind-pollination, polyploidy, low genetic differentiation among populations, sexual and asexual reproduction leading to higher genetic diversity, which gives it strong adaptability with its genetic patterns being very complex across all the sampled latitudes. The findings of this study are related to landscape population evolution, polyploidy speciation, preservation, and use of bermudagrass breeding

    Research and Application of a Quantitative Prediction Method for Sandstone Thickness in a Zone with Dense Well Pattern Development Based on an Objective Function

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    The seismic amplitude along a layer in a section can reveal lateral reservoir changes and is one of the important means of reservoir prediction, but it is often difficult to establish the quantitative relationship between the seismic amplitude and sandstone thickness in wells in blocks with denser development. The use of a lower-amplitude slice for precisely quantitatively predicting the sandstone thickness, based on the goal of obtaining data on layers in the development zone with a dense well pattern, is accurate and has a valuable advantage. The method of formation slice optimization based on an objective function is studied to improve the ability of reservoir characterization by seismic attributes. This method has been applied to the reservoir prediction of the G I2 sedimentary unit in the ZQX block of the SRT oilfield and has achieved good results
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