In this paper, the extraction residue of direct coal liquefaction residue-DCLR(ER) was used as raw material. The high-temperature reaction mechanism of Mo compound in DCLR(ER) was investigated using ...a synchronous thermal analyzer and the Factsage database. The high temperature reaction of DCLR(ER)-MoO3 in an oxygen atmosphere consists of pyrolysis of organic components at 400–600 °C, molybdenum trioxide sublimation at 747–1200 °C, and a stable stage at 600–747 °C. The thermal reaction process of the DCLR(ER)-MoS2 system in the oxygen atmosphere involves the pyrolysis of unreacted coal and asphaltene, the oxidation of molybdenum sulfide at 349–606/666 °C, the diffusion of MoO3 at 606/666–85 °C, and the sublimation reaction process of MoO3 at 854–1200 °C. The results show that the lower heating rate can promote the oxidation of the Mo compound and the sublimation of molybdenum trioxide. On the other hand, the oxides of aluminum, calcium, and iron in DCLR(ER) can inhibit the oxidative pyrolysis efficiency of the DCLR(ER)-MoS2 system.
In order to effectively reduce the impact of Global Navigation Satellite System (GNSS) attacks while providing mobile terminals with credible navigation and positioning results, this paper proposes a ...credible navigation algorithm for GNSS attack detection using an auxiliary sensor system. Based on a credible Kalman filter and measurement information provided by the auxiliary sensor system on mobile terminals, the proposed algorithm can verify the credibility of the GNSS positioning result and determine whether it has suffered from a GNSS attack using the credible verification window and the credible verification threshold. According to the verification results, the algorithm can adaptively select an updated model for measurement correction and achieve a credible navigation result. The algorithm proposed in this paper has been verified on a self-developed mobile terminal, and the experimental results show that the algorithm can provide credible navigation and positioning services for mobile terminals in the context of GNSS attacks.
A continuous operation approach to separate gas mixture via hydrates formation was developed in this paper. We measured the formation condition of CH4/N2/TBAB hydrates, and investigated the ...continuous separation of CH4/N2 via hydrates formation and subsequent dissociation in the presence of TBAB. As an effective hydrate thermodynamic promotor, TBAB significantly reduces the pressure formation of CH4/N2 hydrates and enables the rapid hydration in the crystallizer at relatively low pressures. The separation effects of pressure, temperature, liquid flow, gas flow and TBAB concentration were examined. The concentration of CH4 was shown to increase from 37.5mol% to 52.4mol% in the hydrate phase after continuous separation; the concentration of CH4 in the unhydrated gas decreased to as low as 23.1mol%. The novel and significant achievement of the continuous separation of gas mixtures via hydrates formation shown in this paper is extremely useful in the potential industrial application.
In this paper, direct coal liquefaction residue was prepared from Shen-dong coal, and the solubility of the residue in five organic solvents was studied. Then, an experimental device was set up to ...recover molybdenum (Mo) compounds from the direct coal liquefaction residue after extraction, and the influences of sublimation temperature and duration on recycling efficiency were examined. The recycled Mo-based products were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and a thermal analyzer. The results reveal that the optimum extraction conditions were obtained through ultrasonic extraction with a quinoline solvent and the highest recycling efficiency occurred for sublimation at 900 °C for 30 min. The recycled products are identified to be α-MoO3 crystals. Moreover, the α-MoO3 crystal is thermally stable before the temperature reaches its melting point.
The conversion of agricultural and forestry waste biomass materials into bio-oil by mild hydro-thermal technology has a positive effect on extending the agricultural industry chain and alleviating ...the world energy crisis. The interaction investigation of biomass components during bio-oil formation can be significant for the efficient conversion of lignocellulose when different raw materials are fed together. In this paper, a bio-oil pyrolysis behavior (thermogravimetric analysis, TG) perspective component interaction investigation of cotton stalks under low-temperature hydro-thermal conversion (220 °C) was studied. Cellulose, hemi-cellulose, lignin, and protein were used as lignocellulose model components, by their simple binary blending and multi-variate blending and combined with thermo-gravimetric analysis and gas chromatography-mass spectrometry (GC-MS) characterization and analysis. The interaction of different model components and real biomass raw material components in the hydro-thermal process was explored. Results showed that the components of hydro-thermal bio-oil from cotton stalks were highly correlated with the interactions between cellulose, hemi-cellulose, lignin, and protein. During the hydro-thermal process, cellulose and hemi-cellulose inhibit each other, which reduces the content of ketones, aldehydes, ethers, and alcohols in bio-oil. Interaction between cellulose and lignin was obvious, which promotes the formation of oligomers, such as ketones, aldehydes, esters, phenols, and aliphatic, while inhibiting the production of aromatic and multi-hybrid compounds. Otherwise, there was no obvious interaction effect between hemi-cellulose and lignin or between lignin and protein. This research will guide the industrialization of lignocellulose, especially the possible co-feed hydro-thermal conversion technology.
Tetrahydrofuran (THF) is a popular thermodynamic promotor for gas hydrates. Nonetheless, the phase equilibrium calculations of THF hydrates are limited given the abundant experimental data. In this ...work, we successfully applied the Chen–Guo hydrate model to the THF/CH4/N2 system with different compositions of CH4/N2 gas mixtures. In consideration of various reaction conditions, we proposed the vapor–hydrate two-phase and vapor–liquid–hydrate three-phase models for the equilibrium separations of THF/CH4/N2 via hydrate formation. The hydrate formation condition and equilibrium separation of CH4/N2 in 6mol% THF solution were calculated and compared with experimental results. The average absolute relative deviations between the experimental and calculated data for hydrate formation pressure and equilibrium separation compositions are 6.86% and 7.56%, respectively. This demonstrates that the Chen–Guo model has relatively high accuracy for the equilibrium calculation of THF/CH4/N2 hydrates. This work provides an effective approach to predict the thermodynamic phase behavior of hydrates containing promotors or inhibitors.
The formation, dissociation, and reformation of cyclopentane (CP) hydrate in a sub-millimeter-sized capillary were conducted in this work, and the morphology of CP hydrate was obtained during above ...processes, respectively. The influences of the supercooling degree, i.e., the hydrate formation driving force, on CP hydrate crystals’ aspect and growth rate were also investigated. The results demonstrate that CP forms hydrate with the water melting from ice at the interface between the CP and melting water at a temperature slightly above 273.15 K. With the action of hydrate memory effect, the CP hydrate in the capillary starts forming at the CP-water interface or CP–water–capillary three-phase junction and grows around the CP–water interface. The appearance and growth rate of CP hydrate are greatly influenced by the supercooling degree. It indicates that CP hydrate has a high aggregation degree and good regularity at a high supercooling degree (or a low formation temperature). The growth rate of CP hydrate crystals greatly increases with the supercooling degree. Consequently, the temperature has a significant influence on the formation of CP hydrate in the capillary. That means the features of CP hydrate crystals in a quiescent system could be determined and controlled by the temperature setting.
As a potential therapeutic agent, the clinical application of
-nitrosoglutathione (GSNO) is limited because of its instability. Therefore, different formulations have been developed to protect GSNO ...from degradation, delivery and the release of GSNO at a physiological concentration in the active position. Due to the high water-solubility and small molecular-size of GSNO, the biggest challenges in the encapsulation step are low encapsulation efficiency and burst release. This review summarizes the different nano/micro-formulation strategies of a GSNO related delivery system to provide references for subsequent researchers interested in GSNO encapsulation.
Coke-oven gas (COG), a byproduct of the coking process, has a relatively large fraction of hydrogen (H2). However, most COG is combusted away directly, resulting in serious waste of resources. Taking ...advantage of a separation gas mixture containing H2, we used a hydrate separation method in this work to recover H2 from COG. The formation conditions of COG hydrate were measured in 6 mol % tetrahydrofuran (THF) solution, which could significantly reduce COG hydrate formation pressures and make it possible to realize the industrial application of the separation technology. On this basis, the separation experiments were conducted in THF solution and THF-sodium dodecyl sulfate (SDS) solution, respectively. The experimental results of two-stage separation of COG via hydrate formation were obtained, and the effects of SDS on the reaction velocity were investigated as well. The results show that after one-stage separation, the content of H2 in residual gas can be increased from 48.41 mol % to about 65 mol %, and the recovery of H2 ranges from 81% to 96%. After two-stage separation, the content of H2 in residual gas ranges from 76 mol % to 84 mol %, and the recovery of H2 is between 72% and 91%. With the presence of SDS, the hydration reaction velocity is sped up to some extent, and the induction time and reaction time of hydrate formation are greatly shortened.
► CO–THF hydrate formation pressures are measured at different temperatures. ► We fit complete parameter values of CO required in Chen–Guo hydrate model for the first time. ► Hydrates formation ...conditions of different systems including CO are predicted by Chen–Guo model. ► The parameter values of CO fitted in this work are acceptable. The applied range of Chen–Guo hydrate model is extended.
With a fine accuracy and conciseness, Chen–Guo hydrate model has been widely applied to predict the hydrates formation conditions of different systems, including inhibitor containing systems and salt containing systems. However, the model could not predict the formation condition of carbon monoxide (CO) hydrates as the parameter values of CO required in the calculation are not available. In this work, CO hydrate formation pressures were measured at different temperatures in tetrahydrofuran (THF) solution first, then the parameter values of CO required in Chen–Guo model were fitted completely for the first time. On that basis, the hydrates formation conditions of different systems including CO were predicted by the model to verify the accuracy of the fitted values. The comparison between the predicted results and our experimental data (or literature data) shows that the absolute average deviation percentage (AADP) of structure I hydrates is no more than 1.481%, and the AADP of structure II hydrates is less than 6.796%. It is proved that the fitted parameter values of CO are credible, and Chen–Guo model is capable of predicting the formation conditions of CO hydrates. The experimental results and model modifications extend the applied range of Chen–Guo model and promote the development of CO hydrates thermodynamics research.
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