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Co-pyrolysis of waste plastics and coal has been considered to be an environmentally friendly and scalable waste treatment technology. This study investigated the influence of polyvinyl chloride (PVC) on the physico-chemical structure and gasification performance of co-pyrolytic char with lignite (PZ) and bituminous (SM) coal. The structure characteristics were explored by applying an X-ray diffractometer and a specific surface area analyzer. The quantitative analysis on the influence of PVC on pore characteristics and carbon microcrystal structure was conducted by the fractal theory and deconvolution method. The gasification performance was explored using a thermogravimetric analyzer. When the PZ blending ratio was larger than 50%, the specific surface area of PVCPZ chars enlarged significantly due to the increment of mesopores. Nevertheless, the effect of SM on the pore structure was not pronounced, and the specific surface area of PVCSM chars was as small as PVC char. A higher PZ blending ratio benefited the formation of mesopores with an aperture smaller than 10 nm for PVCPZ chars, whereas SM had little influence on pore diameter distributions of PVCSM chars attributed to the remarkable coating effects. The values of fractal dimension of co-pyrolytic char were larger than PVC char, revealing that the adjunction of coal increased the pore surface coarseness and improved the complicacy of the pore structure. Quantitative analysis on XRD spectra indicated that the disorder extent of the carbon structure was improved because of coal addition, and the influence of lignite on the disorder degree of the carbon structure was more significant. The gasification reaction of co-pyrolytic char showed significant synergistic effects, resulting in the improvement of gasification performance.

Nano-zirconia has been widely applied due to its excellent physical and chemical properties (e.g., high strength, corrosion resistance, oxygen ion conductivity). Existing preparation methods of nano-zirconia tend to require long reaction time, and the sizes of final particles are large with uneven distributions. Sub-/supercritical hydrothermal synthesis of nanoparticles is favored by researchers owing to controllable reaction process, uniform particle size distribution, good reproducibility, short reaction time, high conversion rate and harmlessness to environment. In this paper, the characteristics and mechanisms of dissolution, crystallization and growth of nano-zirconia during sub-/supercritical hydrothermal synthesis are systematically reviewed. The influences of process and material parameters on the size and purity of particles are analyzed. Then, the reaction mechanism and product phase transition mechanism during hydrothermal synthesis of zirconia are summarized to provide a theoretical reference for the oriented preparation. Finally, the improvement and commercialization of sub-/supercritical hydrothermal synthesis technology are evaluated, and the future research topics are proposed.

In the chemical looping with oxygen uncoupling (CLOU) process, CuO is a promising material due to the high oxygen carrier capacity and exothermic reaction in fuel reactor but limited by the low melting point. The combustion rate of carbon is faster than the decoupling rate of oxygen carrier (OC). Hence, high temperature tolerance and rapid oxygen release rate of CuO modified by three different ores were investigated in this study. The kinetics analysis of oxygen decoupling with Cu-based oxygen carriers was also evaluated. Results showed that CuO modified by chrysolite had faster oxygen release rate than that of CuO. Limestone showed obvious positive effect on the oxidization process. The selected OCs could keep stable in at least 20 cycles, for about 1200 min. Shrinking core model (SCM) fitted well for the decoupling process in the temperature range of 1123–1223 K. Reduction rate kinetic information may aid in the development of chemical looping with oxygen uncoupling (CLOU) technologies during reactor design and process modeling. Ternary doped copper oxide with chrysolite and limestone could improve the reactivity of CuO in decoupling and coupling process and also improve the high temperature tolerance.

Hydrothermal liquefaction of the third-generation biomass represented by microalgae can produce biocrude. However, the directly obtained biocrude has a high heteroatom content and a low higher heating value (HHV), which cannot meet the standards of biofuel. In this work, water-insoluble biocrude which was directly gained from microalgae hydrothermal liquefaction (HTL) was upgraded under four kinds of solvents (i.e., methanol, ethanol, acetone, and H₂O) and one type of catalyst (H₂O + Ru/C) at 240–400 °C for 1 h. The results show that the HHV and C and H contents of upgraded bio-oil increased and the O/C ratio decreased significantly after solvent upgrading. The highest upgraded bio-oil yield appeared in the case of ethanol upgrading and reached the maximum value of 82.8 wt % at 360 °C. The upgraded bio-oil yield of acetone upgrading increased from 45.8 to 68.2 wt % as the temperature increased within 240–400 °C. Also, esterification reactions between alcohol and acid in the supercritical system remarkably reduced the content of carboxyl-containing organic matter.

This study investigates the thermodynamic equilibrium analysis of the supercritical water gasification (SCWG) involving several typical feedstocks (coal, sewage sludge, microalga, and sawdust). The effects of various parameters including feed concentrations, temperatures, and pressures are analyzed. It is observed that temperature and feed concentration play a determining role in the yield of hydrogen, while the effect of pressure is very limited. Results show that the feed concentration of 15–20 wt% is optimal for hydrogen production. Furthermore, the effects of composition (hydrogen to carbon ratio and oxygen to carbon ratio) of the feedstock on the yield of product gases are investigated, which is useful for screening potential feedstock for SCWG. The results show that maximum H2 and CH4 molar yields are achieved at a low O/C and a high H/C ratio.

For strengthening the safety and reliability for supercritical water oxidation (SCWO) process, the essential causes and solutions of key challenges such as the high corrosion risk of the heat-exchanger and the entrance part of SCWO reactor, the blockage problems resulted from the solid deposition, and the safety and environmental issues caused by the emergency discharge of supercritical aqueous fluids, were investigated theoretically and experimentally. The thermodynamic state division between chemical- and electrochemical corrosion and the corrosion sensitive temperature range of 280−450 °C featuring the predominant electrochemical corrosion were proposed. A set of optimized parameters for the petrochemical sludge treatment such as a temperature of 520–580 ℃, a pressure of 23−25 MPa, and an oxidation coefficient of 1.1–1.3, which not only can ensure the high enough removal rate of organic pollutants but also prevent the corrosion of construction materials as much as possible; the critical velocity of conveying fluid for avoiding the deposition of solid particles were also obtained. On the bases of innovatively developing the “indirect heat transfer” unit, the mixing-preoxidation equipment, the oxygen removal process for SCWO effluents, and the emergency discharge protection device, a novel SCWO process and its corresponding control scheme were proposed and analyzed.

In this paper, the treatment characteristics of glyphosate wastewater based on supercritical water oxidation (SCWO) technology is studied both in spiral coiled tube reactor and tank reactor, including the influences of operating parameters such as reaction temperature, reaction pressure, oxidation coefficient, residence time, and initial properties of wastewater such as organic concentration, pH value on the degradation of COD and NH3-N with H2O2 as oxidant, and the different reaction characteristics in different batch reactors are also analyzed in detail. Furthermore, the simplified SCWO reaction pathway of glyphosate wastewater is also proposed to understand the degradation process better. Finally, a comprehensive SCWO system for treating glyphosate wastewater efficiently, and transforming and utilizing organic nitrogen as well as organophosphorus directionally is proposed and designed, including SCWO unit, ammonia distillation unit, phosphate recovery unit, and biochemical treatment unit, which can enhance the treatment efficiency and economic benefits synergistically, and provide basic data for the industrialization of glyphosate wastewater degradation based on SCWO technology.

In this paper, the flying heat transfer characteristics of slag particles are studied in the process of the dry centrifugal granulation. When the solidification time of particle surface decreased b...

An economical and environmentally friendly treatment method is urgently needed for the copper-containing spent acidic etchant produced by printed circuit boards. In this work, CuO nanorods with ~30 nm in diameter and ~100 nm in length were prepared from spent acidic etchant by supercritical hydrothermal synthesis. The structures and morphologies of spent acidic etchant-derived CuO (E-CuO) and analytical pure CuCl2-derived CuO (P-CuO) were characterized. The E-CuO has more impurities such as Fe and Zn than the P-CuO. The energy storage performance of the prepared CuO anodes was tested. The E-CuO delivers a high initial discharge capacity of 793.3 mAh·g−1 and a better rate and cycling performance than the P-CuO due to the smaller particles and the doping of Fe and Zn from the spent acidic etchant in the E-CuO.

Supercritical gasification (SCWG) and supercritical partial oxidation (SCWPO) technologies have emerged as preferred means of converting wet biomass to hydrogen-rich gases. We experimentally investigated the effects of moisture content, pressure and oxidation coefficient (n) on mole fraction, yield, gasification efficiency and energy recovery of gaseous products from SCWG or SCWPO of municipal sewage sludge, as well as on the carbon and nitrogen contents in liquid products. Potential of sludge for producing gaseous products was thermodynamically analyzed by an Aspen Plus model. The results show that 87 wt%, 25 MPa and n = 0 were optimum conditions for sludge gasification. Sludge with 87 wt% moisture content was pumpable at 75 °C, and further increasing the moisture content decreased the heating value and energy recovery of gaseous products. Pressure played little role in both the experimental and equilibrium gas yields. Highest mole fractions and yields of H2 and CH4 were achieved at n = 0.

Temperature showed obvious effect on the reaction rate and conversion when CuO was used as an oxygen carrier (OC), in which in situ gasification chemical-looping combustion (iG-CLC) occurred at low...

Lithium iron phosphate (LiFePO4) is one of the most important cathode materials for high-performance lithium-ion batteries in the future, due to its incomparable cheapness, stability and cycle life. However, low Li-ion diffusion and electronic conductivity, which are related to the charging rate and low-temperature performance, have become the bottleneck problem. This review begins with the introduction and comment of and phase transition mechanism in lithium iron phosphate particles, followed by the analysis the application potential of nanotechnology in high performance batteries. Nanoscale LiFePO4 has been prepared easily in the laboratory, but few were prepared on a macroscopic scale, and it is more difficult to enter the industrial production stage. Supercritical hydrothermal synthesis is a nano-preparation technology with great potential for industrial application. This article reviews the key parameters (temperature, pressure, concentration, etc.) and core equipment (mixer/reactor) of supercritical hydrothermal synthesis from the perspective of crystallization mechanism, and then point out the structural optimization design of mixer and development of micro-reactors may be the core work for industrialization of supercritical hydrothermal synthesis.

Crohn's disease (CD) is well characterized by chronic inflammation of the gastrointestinal tract. The diagnose of CD relays on the comprehensive evaluation of patient symptoms, laboratory examination, radiology, and endoscopy. There is lack of biomarkers or simple test for CD detection. Serum samples from healthy subjects (n = 16) and CD patients (n = 16) were collected and prepared for untargeted metabolomics analysis using the ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) method. The alterations of serum metabolites and the potential biomarkers were profiled by statistical analysis. And the associated metabolic pathway was analyzed based on Kyoto Encyclopedia of Genes and Genomes (KEGG) database. The performance of potential biomarkers was assessed by receiver operating characteristic (ROC) analysis. A complete separation between HS and CD groups was seen in OPLS-DA. A total of 108 and 131 significantly altered metabolites in positive and negative ion mode, respectively, were identified, and most of them belong to several pathways ranging from lipid metabolism to amino acid metabolism and energy homeostasis. KEGG analysis revealed that lipid metabolism enriched most significantly. Further, ceramide, phosphatidylethanolamine (PE), and taurochenodeoxycholic acid (TCDCA) presented the highest predictive accuracy of the patients with CD as analyzed by ROC. The current study demonstrated that lipid metabolism is mostly related to CD pathogenesis. Further investigations are indicated to examine the use of lipid-related metabolites of ceramide, PE, and TCDCA as potential biomarkers for CD diagnosis.

Heteroatom-doped carbon can significantly improve the electrochemical performance of LiFePO

A novel and more efficient artificial seepage thermal storage is proposed to exploit the ground temperature energy. The characteristics of the seepage and heat transfer of the working medium (i.e., water) in the thermal storage are numerically explored, based on the successive four seasons. Under the refrigeration condition in summer, the evolution of the outlet water temperature can be divided into the initial, the cold-reduction and the stable phases with the operating time. Moreover, the influence of the injection flow, as well as the thermal conductivity of the anti-seepage layer, on these characteristics is analyzed. During the temperature recovery period in autumn and spring, 79.4% of the heat at the end of summer is stored until the winter, and 78.8% of the cold capacity at the end of winter is stored to the summer. Under the heating condition in winter, the average heat extraction power, when considering the residual summer heat storage, is 1.4 times higher than that without considering the residual heat. Especially, the artificial seepage heat storage is more suitable for the situation that requires both the refrigeration and the heating. It is expected that this work could offer a new idea to develop the geothermal energy.

Objectives As a common model for adverse early experience and depression, maternal separation (MS) is always used to investigate the psychological disease. Despite extensive and strong evidence verified the depression-like state induced by MS, little is known about the specific mechanism of MS. Therefore, the present study aimed to investigate the neurobiology mechanism of the MS-induced depression-like state. Methods To verify the depression-like behaviors of offspring induced by MS, a series of behavioral tests were performed. Then, in vivo electroporation and three-dimensional reconstruction, combining with immunohistochemistry and BrdU labeling, were mainly used to explore the neurogenesis and synaptogenesis in postnatal dentate gyrus. Results Prolonged MS indeed induced the depression-like behaviors of offspring in adulthood. Surprisingly, learning and memory were enhanced by prolonged MS. Further investigation indicated that prolonged MS inhibited the proliferation of neural stem cells, impaired the survival, and altered the fate decision of newborn cells, whereas the total length and terminal tips of dendrite, and the spine density, especially thin spine, were significantly increased in prolonged MS mice. Conclusions Our results elucidated that prolonged MS induced the depression-like state by impairing postnatal neurogenesis of dentate gyrus. Importantly, our results emphasized that prolonged MS increased the spine density, especially thin spine, by increasing the total length and number of terminal tips of dendrite, thereby enhancing learning and memory.

Petrochemical sludge is difficult to be degraded by traditional methods due to the complex organic pollutants, supercritical water oxidation (SCWO) is a promising technology for treating different industrial wastes. In this article, a comprehensive SCWO plant coupled with ammonia distillation and biochemical treatment with the processing capacity near 50 tons per day is designed. Experiments are conducted to determine the influence of reaction temperature, oxidation coefficient and residence time, meanwhile, the species of organics and the concentration of heavy metals in raw feedstock and products are also analyzed to determine the follow-up process. Furthermore, an indirect heat exchange unit between supercritical fluids, capillary device for pressure regulation, and gas–liquid–solid three-phase separator sealed by spiral are proposed to overcome the corrosion and plugging issues. Moreover, an economic evaluation including investment and running cost and the application prospect of the whole system are also analyzed in detail. These information will be significant for designing and constructing the commercial SCWO plant for other industrial wastes.

The optimization and mechanism for oxidation of the waste anion exchange resin from the nuclear industry in supercritical water were investigated. To achieve the maximum chemical oxygen demand (COD...

The construction of cyclobutanes has attracted much attention because of its unique four-membered ring skeleton. Herein, we report the highly enantioselective direct vinylogous Michael reaction of β,γ-unsaturated pyrazole amides and nitroolefin using a squaramide catalyst. Cyclobutane derivatives were obtained by subsequent cyclization in good yields (up to 85%) with excellent enantioselectivities (up to 99% ee). Importantly, the large-scale reaction experiment confirmed the reliability of the vinylogous reaction. Furthermore, the synthetic utility of the vinylogous adducts and cyclobutane derivatives has been realized.

Co-combustion characteristics of wheat straw with polyvinyl chloride under different oxygen concentration atmospheres were investigated using a thermogravimetric analyzer. Experimental samples included wheat straw, polyvinyl chloride, and their blends. The results showed that when the wheat straw was blended with polyvinyl chloride, there was an inhibition for devolatilization in the volatile combustion stage. However, during the char combustion stage, a promotion was observed. As the oxygen concentration increased from 10% to 40%, the ignition temperatures, burnout temperatures, and maximum reaction rate temperatures of all samples decreased, and the combustion characteristic factors ( SN) increased. The combustion of wheat straw was significantly affected by oxygen concentration, whereas the polyvinyl chloride and blends were affected relatively slightly. Especially, as the oxygen concentration increased from 30% to 40%, the combustion of polyvinyl chloride and blends improve slightly. The reason for this behavior is attributed to the diffusion effects of the oxygen and the microstructure changes of the samples. In addition, the activation energies of the co-combustion process under the four atmospheres, for all samples, were calculated by Flynn–Wall–Ozawa method. The kinetic results show that the diffusion effect of the oxygen influenced the apparent activation energies of combustion reaction and the compensation effect of activation energies exists.