The optimization of carbon-based multi-scale structures including morphology, crystallinity and doping functionality has been demonstrated effective in enhancing the anodic properties for sodium ion batteries. A one-step regulation strategy of these multi-scale structures is still highly desirable. Herein, we report a simple boron doping strategy to achieve simultaneous optimization of carbon-based multi-scale structures including spherical morphology, crystalline parameters and boron doping environment to enable enhanced Na⁺ storage properties and high-performance full-cell sodium ion batteries. The carbon synthesis is achieved by a hydrogen bond guided co-assembly process followed by high-temperature carbonization with boric acid and glucose as boron and carbon sources, respectively, which endows the obtained boron-doped hard carbon nanospheres with a polydisperse nanosphere morphology, specific boron species (BC₃ and B–C–O) and enlarged interlayer distance. These structural merits collectively enable the improved Na⁺ storage capacity and rate capability. In particular, the plateau capacity of the boron doped carbon anode increases by 67% as compared with the non-doped carbon anode; especially, the intercalation capacity increases by nearly 3 times. Density functional theory calculations for the first time reveal the enhanced Na⁺ diffusion and insertion dynamics within the boron doped carbon interlayer, which explains the greatly boosted intercalation capacity. Furthermore, the galvanostatic intermittent titration technique (GITT) and operando measurement collectively demonstrated that the boron doped carbon anode promotes the diffusion dynamics of Na⁺ between microcrystalline interlayers, hence facilitating a diffusion-controlled Na⁺ insertion process. The constructed full-cell exhibits a high energy density of 244.6 W h kg⁻¹ and an excellent cycling stability, implying the application potential of the boron doped hard carbon spheres in sodium ion batteries.

Roasting is an important step in the pretreatment of biomass upgrading. Roasting can improve the fuel quality of biomass, reduce the O/C and H/C ratios in the biomass, and provide the biomass with a fuel quality comparable to that of lignite. Therefore, studying the structure and component evolution laws during biomass roasting treatment is important for the rational and efficient utilization of biomass. When the roasting temperature is 200–300 °C, the cellulose and hemicellulose in the biomass undergo a depolymerization reaction, releasing many monocyclic aromatic hydrocarbons with high reactivity. The proportion of monocyclic aromatic hydrocarbons in biomass roasting products can be effectively regulated by controlling the reaction temperature, residence time, catalyst, baking atmosphere, and other factors in the biomass roasting process. This paper focuses on the dissociation law of organic components in the pretreatment process of biomass roasting.

With the development of power plant units of higher capacity and with improved parameters, the proportion of high-capacity units for generating power has increased; this requires large capacity units to take responsibility for power-grid peak shaving. When the boiler operates at low loads, the working fluid in the boiler water wall tubes is subjected to high heat flux in the furnace, which can cause heat transfer deterioration, tube overheating or even leakage. Therefore, it is particularly important to study the reliability of the boiler hydrodynamic cycle during peak shaving (low load operation). This study takes a 1000 MW ultra-supercritical single-reheat Π type boiler with single furnace and double tangential firing as the research object. A furnace Computational Fluid Dynamics (CFD) and hydrodynamic coupling analysis model is established and verified according to the actual operating conditions on site. The calculation results show that the simulated value is in good agreement with the actual operating value. Therefore, the model established in this study can reflect the real situation of the on-site furnace to a certain extent, and has high reliability. Based on the fitting results, the causes of steam temperature deviation of the boiler water wall are analyzed, and measures to reduce the deviation are proposed to provide a necessary basis for power plant operation and boiler design.

To tackle the overheating problem of the heating surface in deep peak shaving, it is urgent to develop working substance (steam) temperature regulation and heating surface safety control technologies that combine combustion and hydrodynamic instability evaluation. This work relies on a 1000 MW boiler involved in deep peak shaving, and adopts CFD numerical simulation technology to obtain reasonable holographic heat load data of the boiler. The heat load data and the working substance side data are coupled to develop a real-time performance calculation model that combines combustion and hydrodynamic steam temperature. Real-time monitoring of the local position of the boiler water wall and the convection heating surface can be achieved through the three steps: heat load screening, heat exchange process calculation, and result display. The results show that through the corresponding expression of on-site industrial parameters and CFD simulation data, the effective analysis, extraction, modeling and optimization of the operation data can be realized for real-time online monitoring and intelligent early warning of the entire working condition. The model error is less than 2 °C and the model can realize early warnings at 5 min, so as to ensure the safety and stability of boiler operation and save the operating cost of the power plant to a certain extent.