Global Energy Awards

Abstract Torrefaction can effectively improve biomass physicochemical properties and mitigate adverse effects during coal co-firing, while nitrogen migration differences between woody and herbaceous biomass during torrefaction remain unclear. This work investigates torrefaction effects on woody Salix psammophila (SP) and herbaceous Arundo donax (AD), focusing on NOx emission and fuel nitrogen migration during co-firing. The results show that torrefaction temperature significantly affects the product distribution. Considering low heating value (LHV) and energy yield, 270 °C is the optimal torrefaction temperature.  Under N2 atmosphere, the N-A functional groups in SP mainly transform into N-5 and tar-N, and the oxidative atmosphere inhibits this transformation process. In contrast, under N2 atmosphere, the N-A functional groups in AD convert into tar-N and N-Q, and the oxidative atmosphere promotes the formation of N-Q. The co-firing mode has a significant impact on NOx emissions du...

  Abstract As a key component of the marine soundscape, ocean ambient noise has a significant impact on underwater acoustic detection. However, the observational understanding of very low-frequency noise dynamics during sea-ice freeze–thaw cycles in shallow seas remains limited. In this study, we conducted nearly two months of concurrent measurements of sea ice, waves, and ambient noise in the coastal Bohai Sea, capturing a complete sea-ice freeze–thaw cycle.  Using a newly developed vector hydrophone, we recorded wave-related seismic noise (WRSN) in the 0.1–0.3 Hz band, which showed a strong correlation with wave amplitude. Because sea-ice formation significantly attenuates ocean waves, we observed the WRSN amplitude declining rapidly upon ice formation and recovering to baseline levels after the ice had completely melted. Polarization analysis of the three-dimensional ground motion indicated that the WRSN was generated primarily by local wave-induced vertical seismic waves, ...

  Abstract Heat sinks having extended surface area can substantially increase the heat dissipation limit of two-phase immersion cooling compared to the critical heat flux limit of flat surfaces. However, the highly nonlinear and boiling-regime-dependent surface boundary condition makes designing an optimal two-phase immersion heat sink a challenge, and no systematic design approach currently exists. In this work, we propose a density-based topology optimization method for designing heat sinks under pool boiling conditions. Boiling on a heat sink is modeled as a conduction problem with convective boundary condition, where the heat transfer coefficient is defined as a function of superheat and spans all boiling regimes (natural convection, nucleate boiling, transition boiling, and film boiling).  The heat sink is represented as voxelized density distribution within the design domain, with the thermal conductivity modeled as a function of local density. The boiling boundary condi...

  Abstract Aqueous zinc-ion batteries show promising prospects for large-scale energy storage due to their low cost and high safety. Nevertheless, their practical application is constrained by issues such as water-induced side reactions and the growth of zinc dendrites. In this study, we design a water-free deep eutectic electrolyte (FAU) which consists of zinc trifluoromethanesulfonate, acetamide, and urea.  By eliminating the aqueous environment to suppress parasitic reactions and regulating the Zn2+ solvation structure, the reversibility and stability of the zinc anode are significantly enhanced. Moreover, this electrolyte promotes uniform and dense zinc deposition while forming a unique and stable organic-inorganic hybrid solid electrolyte interphase layer on the zinc anode surface, thereby effectively inhibiting dendrite growth and zinc corrosion. The Zn||Zn symmetric cell employing the FAU-4 electrolyte demonstrates stable cycling for over 5100 h and exhibits excellent a...