Gas-liquid separators are commonly utilized in the energy and chemical industries. This paper briefly introduces the separation principles and research progress of the primary gas-liquid separation ...equipment domestically and internationally. The paper briefly summarizes the working principles of gravity separation, filtration separation, and centrifugal separation equipment. Next, attention is focused on optimizing the separation performance of centrifugal separation equipment, which offers advantages of small size and high separation efficiency. Finally, a comparative analysis of these gas-liquid separators is provided.
Highly crystalline graphitic carbon nitride (g‐C3N4) with decreased structural imperfections benefits from the suppression of electron–hole recombination, which enhances its hydrogen generation ...activity. However, producing such g‐C3N4 materials by conventional heating in an electric furnace has proven challenging. Herein, we report on the synthesis of high‐quality g‐C3N4 with reduced structural defects by judiciously combining the implementation of melamine–cyanuric acid (MCA) supramolecular aggregates and microwave‐assisted thermolysis. The g‐C3N4 material produced after optimizing the microwave reaction time can effectively generate H2 under visible‐light irradiation. The highest H2 evolution rate achieved was 40.5 μmol h−1, which is two times higher than that of a g‐C3N4 sample prepared by thermal polycondensation of the same supramolecular aggregates in an electric furnace. The microwave‐assisted thermolysis strategy is simple, rapid, and robust, thereby providing a promising route for the synthesis of high‐efficiency g‐C3N4 photocatalysts.
Highly crystalline graphitic carbon nitride (g‐C3N4) was synthesized within 16 min by microwave‐assisted thermolysis of melamine–cyanuric acid supramolecular aggregates. The H2 generation rate achieved with the as‐obtained g‐C3N4 material is two times higher than that of a sample prepared by heating the same supramolecular aggregates in a furnace at 540 °C for 2 h.
A hydrogen fuel cell ship needs to carry a great amount of hydrogen as the fuel, which powers the ship but simultaneously poses threats on ship's safety because of the hydrogen's leakage- and ...explosion-proneness properties. This study focused on a hydrogen fuel cell ship, and we established the corresponding geometrical model. In case of the occurrence of hydrogen explosion, hydrogen leakage was first calculated based on the leakage model; then, using the ANSYS fluent (a fluid computation software), the hydrogen's diffusion process in various compartments was simulated and the variation of hydrogen concentration distribution with the leakage time was concluded. Finally, numerical simulations were conducted under different conditions when the ignition source appeared in the fuel cell compartment, the control compartment and the passenger compartment, respectively, and the overpressure and high-temperature damages induced by the explosion were analyzed in detail. The present simulations on leakage and explosion of hydrogen can help us to obtain more details on the consequences after the accident, and thereby we could propose the appropriate design scheme, management method and escape measures to reduce the risk of leakage accidents on the ship and enhance the safety of HFCSs.
•Hydrogen's diffusion and concentration in ships during the leakage process.•Numerical simulations under the ignition source appeared in different compartments.•The explosion consequence based on the results of overpressure and thermal damage.
Due to the pressures caused by the energy crisis, environmental pollution, and international regulations, the largest ship-producing nations are exploring renewable resources, such as wind power, ...solar energy, and fuel cells to save energy and develop more environmentally-friendly ships. Solar energy has recently attracted a great deal of attention from both academics and practitioners; furthermore, the optimization of energy management has become a research topic of great interest. This paper takes a solar-diesel hybrid ship with 5000 car spaces as its research object. Then, following testing on this ship, experimental data were obtained, a multi-objective optimization model related to the ship’s fuel economy and diesel generator’s efficiency was established, and a partial swarm optimization algorithm was used to solve a multi-objective problem. The results show that the optimized energy management strategy for a hybrid energy system should be tested under different electrical loads. Moreover, the hybrid system’s economy should be taken into account when the ship’s power load is high, and the output power from the new energy generation system should be increased as much as possible. Finally, the diesel generators’ efficiency should be taken into consideration when the ship’s electrical load is low, and the injection power of the new energy system should be reduced appropriately.
We report a new type of Au@TiO2–CdS ternary nanostructure by decorating CdS nanoparticles onto Au@TiO2 core–shell structures. In comparison to that of binary structures such as CdS–TiO2 and Au@TiO2, ...these ternary nanostructures exhibit a remarkably high photocatalytic H2-generation rate under visible-light irradiation. The enhanced photocatalytic activity is attributed to the unique ternary design, which builds up a transfer path for the photoexcited electrons of CdS to the core Au particles via the TiO2 nanocrystal bridge and thus effectively suppresses the electron-hole recombination on the CdS photocatalyst. This internal electron-transfer pathway (CdS → TiO2 → Au) eliminates the need for the postdeposition of the metal cocatalyst because the core Au nanoparticles can act as the interior active catalyst for proton reduction toward hydrogen evolution. We believe that our work demonstrates a promising way for the rational design of metal–semiconductor hybrid photocatalysts that can achieve a high photocatalytic efficiency for use in solar fuels production.
Metal−organic framework (MOF) UiO‐66/graphitic carbon nitride (g‐C3N4) hybrids show enhanced photoactivity for hydrogen evolution using visible light. The efficient charge transfer from photoexcited ...g‐C3N4 to UiO‐66 MOF is responsible for the enhancement in photocatalytic hydrogen production. The qusi‐polymeric nature of the present hybrids makes MOFs a potential candidate to construct active photocatalysts.
In the traditional microwave heating partial differential equation (PDE) model, one of the main characteristics is the infinite-dimensional nature, which does not allow to readily design and ...implement a controller. Motivated by this obstruction, this paper proposes a microwave heating finite-dimensional ordinary differential equation (ODE) model, which can not only describe the thermodynamics field with nonhomogeneous boundary conditions but also be coupled with the variation of electromagnetic field in temperature-dependent dielectric media. Initially, the equivalent PDE model with a homogeneous boundary condition is derived by constructing an auxiliary function in order to directly derive the eigenspectrum of the spatial differential operator. With the help of model-reduction techniques, the dominant dynamics of temperature distribution are subsequently captured with a reasonable Galerkin truncation. The simulation results on microwave heating a water prototype show that the temporal and the spatial evolution of the temperature profile can be described by solving the temperature-dependent electromagnetic field and the finite-dimensional ODE model. Moreover, the effectiveness of the model is verified by comparing with the numerical results from the traditional COMSOL model. A further development of this ODE model may provide a useful numerical tool for the design and synthesis of microwave heaters to avoid thermal runaway phenomena.
Amine‐functionalization of TiO2 nanoparticles, through a solvothermal approach, substantially increases the affinity of CO2 on TiO2 surfaces through chemisorption. This chemisorption allows for more ...effective activation of CO2 and charge transfer from excited TiO2, and significantly enhances the photocatalytic rate of CO2 reduction into methane and CO.
Amine functionalization of TiO2 nanoparticles substantially increases the affinity of CO2 on TiO2 surfaces for more effective CO2 activation. It also greatly enhances the photocatalytic rate of CO2 reduction into CH4 and CO (see figure; VB=valence band, CB=conducting band).
Energy management strategy is a key technology of hybrid power ships. In recent years, renewable energy ship technologies have become a popular research field and one promising development direction ...to realize reasonable utilization of energy resource, as well as energy conservation and emission reduction. Among these technologies, the solar energy hybrid ship technology is currently attracting attention all over the word. In this paper, a 5000-car space solar energy hybrid ship is used as the research objective, and an energy management strategy that is based on fuzzy logic is proposed to distribute the ship power generation, solar energy, and battery output power according to the ship’s electrical load demand, and the fuzzification and stochasticity of solar energy. By comparing the simulation results with real ship testing results, it is identified that the proposed fuzzy logic energy management strategy can optimize the operation conditions of individual power generation sources, improve the overall performance of power system, and reduce the ship’s overall fuel consumption.
Three-dimensional surface-enhanced Raman scattering (SERS) substrates usually provide more hot spots in the excitation light beam and higher sensitivity when compared with the two-dimensional ...counterpart. Here a simple approach is presented for the fabrication of arrays of Ag-nanoparticles decorated TiO
2
nanotubes. Arrays of ZnO nanorods were fabricated in advance by a hydrothermal method. Then TiO
2
nanotube arrays were achieved by immersing the arrays of ZnO nanorods in an aqueous solution of (NH
4
)
2
TiF
6
for 1.5 h. Vertically aligned TiO
2
nanotube arrays were modified with dense Ag nanoparticles by Ag mirror reaction. High density of Ag nanoparticles decorated on the fabricated TiO
2
nanotubes provide plenty of hotspots for Raman enhancement. In addition, the fabricated array of Ag nanoparticles modified TiO
2
nanotubes can serve as a reusable SERS substrate because of the photocatalytic activity of the TiO
2
nanotubes. The SERS substrate adsorbed with analyte molecules can realize self-cleaning in deionized water after UV irradiation for 2.5 h. The sensitivity of the fabricated SERS substrate was investigated by the detection of organic dye molecules. The detectable concentration limits of rhodamine 6G (R6G), malachite green (MG) and methylene blue (MB) were found to be 10
−12
M, 10
−9
M and 10
−8
M, respectively. The enhancement factor (EF) of the three-dimensional SERS substrate was estimated to be as high as ∼1.4×10
8
. Therefore, the prepared Ag nanoparticles modified TiO
2
nanotube arrays have promising potentials to be applied to rapid and trace SERS detection of organic chemicals.
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