Solar-driven H2O/CO2 splitting via two-step thermochemical cycle is a promising path for renewable fuel production. However, the energy losses caused by the high solar thermal temperature and the significant technical...
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Light alkanes are a class of ubiquitous volatile organic compounds (VOCs), which bring great environmental hazards and health risks. However, low-temperature degradation of light alkanes is still a great challenge. He...
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To develop a low-carbon power system with high renewable energy penetration, this study proposes a novel power-to-heat energy storage and power generation (P2HES-PG) system, which utilizes molten salt thermal storage ...
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The integrated CO2 capture and conversion (ICCC) has emerged as a promising and cost-effective pathway for achieving carbon neutrality. However, limited energy-efficient pathways and durable materials for ICCC systems...
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Supercritical water (SCW) gasification is one of clean and efficient utilization way of biomass, other organic matters or coal for hydrogen production, in which radical reactions studies in SCW are limited but crucial...
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Improving boiling heat transfer in thin liquid films by employing external electrical fields and macro-structured surfaces presents promising for tackling the growing difficulties related to high-heat-flux thermal man...
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Spent lithium-ion batteries pose significant environmental hazards but also possess high recycling value. In this study, a process for the recovery of valuable metals from spent LiNi0.5Co0.2Mn0.3O2 cathode materials (...
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Spent lithium-ion batteries pose significant environmental hazards but also possess high recycling value. In this study, a process for the recovery of valuable metals from spent LiNi0.5Co0.2Mn0.3O2 cathode materials (NCM523) was proposed by using NaHSO4 as the sulfation agent. The thermal decomposition of NaHSO4 and its sulfation roasting process with spent NCM523 were investigated. The findings revealed that NaHSO4 started decomposing at approximately 200 °C, releasing Na2S2O7. And significant SO2 gas was emitted after 400 °C, efficiently reducing and sulfating the valuable metals in NCM523. The sulfation roasting parameters were optimized by examining the influences of roasting temperature and the mass ratio of NaHSO4 to waste cathode materials on the leaching efficiencies of valuable metals. Experimental results indicated that Li was present as Li2SO4 and NaLiSO4 forms after roasting, while other valuable metals existed in complex forms, mainly as bimetallic composite sulfates. The study found that under optimal conditions, with a NaHSO4 to waste cathode material mass ratio of 5:1, and roasting at 600 °C for 120 min resulted in the highest leaching efficiencies for valuable metals, with Li at 98.4 %, Co at 97.1 %, Ni at 96.1 %, and Mn at 96 %. Additionally, the non-isothermal kinetic of the roasting process was studied, determining the apparent activation energy of each stage and identifying the controlling steps through the Kissinger-Akahira-Sunose (KAS), Flynn-Wall-Ozawa (FWO), and Starink methods. The mechanisms were elucidated using the Satava-Sestak and Coats-Redfern equations, which identified the fourth stage as the controlling step with an average activation energy of 211.4 kJ/mol, indicating a three-dimensional diffusion model. The results highlighted that utilizing NaHSO4 roasting for recycling waste cathode materials led to high leaching efficiencies of Li, Co, Ni, and Mn metals at lower temperatures. This aligned well with the principles of efficient
Elevated water cut obstructs recovery of heavy oil in later stage of heavy oil reservoir exploitation. This paper simulates such scenarios using one-dimensional sandstone cores filled with saturated oil utilizing hot ...
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Industrial gas leaks and flue gas emissions pose significant threats to the safety of industrial operations and the atmospheric ecological environment. Traditional gas sensing materials often struggle to meet the chal...
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This study delves into the control strategies for the Fluoride-salt-cooled High-temperature Reactor-Supercritical CO2 (SCO2) Brayton cycle power generation system under rapid grid load reduction scenarios. By developi...
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This study delves into the control strategies for the Fluoride-salt-cooled High-temperature Reactor-Supercritical CO2 (SCO2) Brayton cycle power generation system under rapid grid load reduction scenarios. By developing a dynamic simulation model, the system's dynamic response characteristics under rapid load changes were analyzed, and a combined control strategy emphasizing safety, speed, and economic efficiency was proposed. The research first compared the dynamic response characteristics and steady-state performance of different bypass configurations under load rejection conditions. The computational results indicate that all three bypass control systems exhibit excellent load-following capabilities, effectively responding to a 50 % load step change within 10 s. However, significant differences were observed in their steady-state thermodynamic performance: the upper cycle bypass control achieves the highest steady-state efficiency (η = 29.92 %), followed by the turbine bypass control (η = 27.50 %), with the heat source bypass control showing relatively lower efficiency (η = 26.49 %). Although the upper cycle bypass offers superior efficiency, it leads to a substantial increase in the working fluid flow through the compressor (ΔQ = 15 %) during operation, raising the risk of compressor blockage and necessitating additional flow restriction and anti-blocking interlock control systems. Considering system safety, control complexity, and engineering feasibility, the turbine bypass system, with its relative independence and lower operational risk, is deemed more suitable as the primary control strategy for load rejection conditions. Building on this, the study proposes a combined control strategy that leverages the strengths of both bypass control and inventory control. During the initial phase of rapid load reduction, the bypass control system quickly adjusts the turbine bypass valve opening to promptly respond to grid load changes, ensuring system frequency stability
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