In accordance with international environmental protection conventions, some high GWP HFCs refrigerants are facing obsolescence and destruction. Therefore, it is necessary to develop energy-saving, high-efficiency destruction way. In this paper, the performance differences of various catalysts in the photothermal catalytic degradation of R134a was compared based on existing technical route. Furthermore, the effects of material properties on the reaction rate, such as morphology, band structure and photoelectric properties, were obtained through characterization of catalysts. Based on the law of the effects, anatase TiO₂ was selected for modification. The modified catalyst achieved a degradation rate of over 98% within 30 minutes, with the reaction rate increasing by 3.8 times.

In hydrogen liquefaction systems, the continuous catalytic conversion of ortho-para hydrogen is recognized as a key technology for achieving low energy consumption. The conversion heat of ortho-para hydrogen, which exhibits temperature dependence, is observed to vary significantly along the course of the heat exchanger, influencing the cooling process of hydrogen gas flow. This study investigates continuous conversion cryogenic hydrogen plate-fin heat exchangers, employing theoretical analysis and the development of a dynamic simulation model to explore the heat exchange and catalytic matching characteristics of such exchangers. Optimal cold fluid flow rates in various temperature zones have been determined. When helium is used as a cold fluid, optimal cold-to-hot mass flow rate ratios of 3.5 in the 80∼60 K range and 4.7 in the 60∼40 K range are identified. The dynamic simulation elucidates the heat transfer-catalytic matching relationship between normal hydrogen conversion and the cooling fluid in hydrogen heat exchangers, offering insights for the design and optimization of hydrogen liquefaction processes. These findings contribute to enhancing process efficiency, reducing energy consumption, and promoting sustainable development in the
hydrogen energy sector.

Ti₃CN MXene exhibits remarkable electrical conductivity and photothermal conversion capabilities, making it a promising co-catalyst for photothermal catalytic CO₂ reduction. This study utilizes two-dimensional mono-multilayer structured Ti₃CN MXene to in-situ construct heterojunctions. A series of analyses, including AFM, SEM, TEM, XRD, XPS, UV-vis DRS, and i-t tests combined with DFT simulation calculation were conducted. The photothermal catalytic activity of each catalyst was tested under different energy input conditions. We discovered that the bandgap of Ti₃CN/TiO₂ is narrowed to 2.94 eV compared to that of TiO₂, facilitating efficient electron transport from Ti₃CN to TiO₂ via the NC-Ti-O electron bridge at the interface, which enhances optical absorptivity and carrier mobility. The catalytic performance evaluation revealed a significant photothermal synergistic effect in CO₂ reduction with Ti₃CN/TiO₂, the CO yield reached 8.34 μmol·g⁻¹·h⁻¹, which is 3.83 times greater than that achieved with TiO₂ alone. These findings underscore the impact of Ti₃CN-supported TiO₂ on photothermal synergistic CO₂ reduction characteristics

With the continuous expansion of the scale of central heating system (CHS), the coupling relationship between the variables in CHS has become increasingly complex. Establishing the security analysis method considering variable coupling characteristics is of great significance to improve the security level of CHS operation. A security analysis method for the hydraulic and thermal states of CHS is proposed based on the vulnerability index, which quantitatively analyzes the impact of control variables such as hydraulic resistance, pump head, and heat source heating temperature on the security of state variables such as node pressure and heat load indoor temperature. The vulnerable state variables corresponding to each control variable and the key control variables corresponding to each state variable in CHS are identified based on the vulnerability index matrix. In the CHS case study, the effectiveness of the proposed method is verified by comparing the energy flow calculation results with the analysis results based on the vulnerability index.

As concerns about climate change continue to grow, the conundrum of how to produce carbon-neutral fuel needs to be addressed. This paper proposes a multi-energy co-generation system with solar thermochemical cycle based on chemical-looping cycle oxygen removal, which uses chemical-looping cycle to absorb oxygen generated by thermochemical cycle to improve the reduction degree of oxygencarrier Through the combined cooling, heating and power system, the hightemperature thermal energy generated by chemical-looping cycle is utilized in a cascade manner to output electricity, cold energy and low-grade thermal energy. The results show that NiO/Ni is more suitable as oxygencarrier in chemical-looping cycle. When the pressure ratio of chemical-looping cycle is 5 and the thermal chemical cycle reduction temperature is 1500°C, the solar utilization efficiency and exergy efficiency reached 28.5% and 23.5% respectively, and when the reduction temperature rose to 1600°C, these efficiencies rose to 32.2% and 25.5% respectively. The use of multi-energy cogeneration system can save 57.4% of methane and reduce carbon emissions. Theoretical calculation shows that if the energy supply of the multi-energy cogeneration system is completely relied on, the annual energy consumption per capita of Beijing and Shanghai residents needs 12.1 m² and 7.3 m² of concentrating area.