Microwave continuous-flow heating has been proven to reduce the time of chemical reaction, increase the conversion rate, and improve product purity effectively. However, there are still problems such as relatively low heating efficiency, unideal heating homogeneity, and poor compactness, which brings further drawbacks like difficulty in fabrication and integration. In this study, a compact microwave continuous-flow heater based on six fractal antennas is proposed to address the problems above. First, a multi-physics simulation model is built, while heating efficiency and the volumetric coefficient of variance (COV) are improved through adjusting the geometric structure of this heater and the phase assignment of each radiator. Second, an experiment is conducted to verify the simulation model, which is consistent with the simulation. Third, a method of fast varying phases to achieve greater heating efficiency and heating homogeneity is adopted. The results show that the single-phase radiator improved efficiency by 31.1%, and COV was significantly optimized, reaching 64%. Furthermore, 0–100% ethanol–water solutions are processed by the heater, demonstrating its strong adaptability of vastly changing relative permittivity of liquid load. Moreover, an advance of this microwave continuous-flow heater is observed, compared with conventional multi-mode resonant cavity. Last, the performance of this microwave continuous-flow heater as the chemical reactor for biodiesel production is simulated. This design enables massive chemical production in fields like food industry and biodiesel production, with enhanced compactness, heating efficiency, and heating homogeneity.

Deep eutectic solvents (DESs) as relatively novel green solvents have potential spread wide applications in separation processes, especially for acid gases and volatile organic compounds (VOCs) absorption. However, the high viscosity of typical DESs can decrease the mass transfer rate and increase energy consumption for pumping, thereby limiting their overall efficiency and feasibility in industrial applications. In this work, the efficient absorption of 1,2-dichloroethane (DCE) was intensified by designing a series of low-viscosity DESs, and the absorption performance, separation mechanism, and conceptual industrial process simulation were systematically investigated. The results showed that 3,4-DMOET:ButA with molar ratio of 1:2 was chosen as the suitable absorbent for DCE due to its maximum saturated absorption capacity (2746 mg/g at 20 °C, atmospheric pressure, and saturated content of DCE in the feed gas) and minimum viscosity property (26.51 mPa·s at 20 °C). The absorption mechanism was investigated by ¹H NMR, FT-IR and quantum chemical (QC) calculations, indicating that the absorption was a physical process. The weak interaction analysis results illustrated that both HBD and HBA play an important role in the separation. Specifically, C-H···π and C-H···Cl are the main contributors to the HBA-DCE interaction, while C-H···O HB and vdW interactions played a dominant role in the HBD-DCE interaction. According to the process simulation results of DES absorbing DCE, it can be seen that DES exhibits a high DCE removal performance. The process intensification strategy may be directly extended to absorb other VOCs.

CaCl ₂ /MOF-303 composites were prepared by impregnating CaCl ₂ into MOF-303, they showed large water adsorption capacity, high regenerative rate and excellent structural stability, proving a broad application prospect in the field of dehumidification.

Microwave radiation has become an effective catalytic combustion method, especially in the degradation of volatile organic compounds (VOCs) such as toluene using catalysts like MnO₂. In this study, a spine waveguide microwave reactor was designed to investigate the influence of different microwave processing conditions on the degradation of toluene catalyzed by MnO₂. An experimental system for microwave-assisted catalytic degradation of toluene was established to explore the relationship between microwave power, catalyst conductivity, and toluene degradation rate. The results showed that the efficiency of MnO₂ catalyzing toluene degradation had a nonlinear relationship with microwave power, first increasing to a peak and then decreasing. Additionally, the experiment found that the degradation rate of toluene was positively correlated with the conductivity of MnO₂. Subsequent characterization analyses using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) further verified the changes in the microstructure and properties of MnO₂ under microwave heating. The characterization results showed that with the increase in microwave power, the relative content of Mn³⁺ on the surface of MnO₂ increased, and the relative content of adsorbed oxygen also increased accordingly. At a microwave power of 100 W, the treated MnO₂ displayed the optimal ratio of manganese oxidation state and oxide, both close to 1:1, which was more conducive to the degradation of toluene. Based on these findings, this study hypothesized that the microwave-enhanced catalytic degradation of toluene by MnO₂ may be attributed to changes in the surface electron transfer kinetics of MnO₂, providing new insights into the field of microwave-enhanced catalysis.