As the global climate change intensifies, carbon capture, utilization and storage technology (CCUS) has become a crucial means to achieve the goal of carbon neutrality. Focusing on addressing the issues of poor operational stability and high regeneration energy consumption in conventional absorption agents, a new water-poor compound absorption agent was developed, which is mainly composed of tert-butyl aminoethanol (TBAE). The absorption agent was optimized by combining different ratios of amines and stabilizers and was mixed at a total amine mass fraction of 30%. The CO₂ absorption-desorption performance, corrosion situation, and small-scale upscaling experiment were tested and investigated using 30% (mass fraction) conventional absorption agent ethanolamine (MEA) as a reference standard. The aim is to enhance the CO₂ absorption capacity and desorption rate while reducing regeneration energy consumption and improving the stability of the solvent in the device. The experimental results indicate that, when the formula is 20% TBAE + 10% 3-methyl-1-propanol + 50% N-methylpyrrolidone, the saturated CO₂ absorption capacity is 3.10 mol/L, the cyclic absorption capacity is 2.97 mol/L, the corrosion rate is 0.016 2 mm/a, and the regeneration energy consumption is 4.00 GJ/t. Compared with the 30% MEA absorption agent, the saturated CO₂ absorption capacity increases by 12.3%, the cyclic capacity rises by 22.7%, the corrosion rate reduces by 60.3%, and the regeneration energy consumption decreases by 36%. The excellent basic performance of the new water-poor compound absorption agent and its long-term stable and low-energy operation in a 10 t/a carbon capture small-scale pilot plant have laid a solid foundation for its future industrial application.

In the oxygen combustion CO₂ cycle, heat integration of the air separation unit (ASU) is commonly used to improve the matching of the heat recovery process. However, the ASU heat integration increases the heat recovery load, and the relatively low load ramp rate of the ASU affects the overall performance of the system. To eliminate the need for ASU heat integration and further enhance cycle efficiency, a method involving split adiabatic compression is proposed to balance the thermal capacities of the hot and cold streams. A power generation system model based on the gasification oxygen combustion CO₂ cycle is developed in Aspen, and the thermodynamic performance of the system, as well as the effect of ASU heat integration, are analyzed. A recompression system is also introduced for comparison. The results show that, the conventional system with integrated ASU heat has a net efficiency of 43.39%. Compared with a system without heat integration, the power consumption of the ASU increases by 19.9 MW, while 180.8 MW of heat integration is provided, resulting in a 1.64 percentage points increase in net efficiency. Considering limitations in heat recovery, the optimal split mass flow rate for the recompression system is 258.2 kg/s. Compared with the ASU heat integration, the recompression system reduces the heat recovery load by 59.8 MW, and the average heat exchanger temperature difference is further reduced by 3.1 ℃, improving the net efficiency to 43.52%. The study reveals the mechanism by which heat integration affects the efficiency of the oxygen combustion CO₂ cycle and proposes an optimization to decouple the power cycle from the ASU heat integration through the recompression process, providing theoretical guidance for the parameter design of the recompression system.

Direct air carbon capture (DAC) technology has been booming in the past decade, and now it has gradually developed from laboratory toward commercial device. Because the adsorption DAC is more promising than absorption DAC, some companies have launched DAC demonstration projects based on adsorption. However, there is relatively little introduction to these companies and projects based on adsorption DAC in current research, and a comprehensive study has not yet been formed. In view of the above reasons, some representative companies owning adsorption DAC technologies and their projects are investigated through existing literatures and their corporate websites, and the key contents are focused. In addition, the device types of these enterprises are divided into centralized devices and integrated devices according to the arrangement of equipment, and the characteristics of these two types of devices are introduced. By summarizing the characteristics of DAC enterprises and technologies, it is found that most enterprises are committed to reducing operation and investment costs, so the possible cost reduction methods in the future industrialization process are put forward and the effects are analyzed.

Carbon capture, utilization and storage (CCUS) is a key technology to mitigate the impact of CO₂ emissions on the environment, and CO₂ geological storage and utilization is an important part of CCUS. This paper analyzes the global development trend of CO₂ geological storage and utilization technology, reviews the current development situation in China from the aspects of policy system construction, project implementation and research results, interprets the research frontiers in this field through literature analysis, and prospects the development of CO₂ geological storage and utilization. Current research focuses on the CO₂ geological storage and utilization in depleted oil and gas reservoirs, induced seismic mechanism and monitoring, leakage monitoring and environmental assessment, CO₂ geological storage and energy resources cooperative development and utilization, and rapid mineralization storage. In the future, research in this field should focus on the complex multi-field and multi-phase study in CO₂ geological storage and utilization, building a whole-process intelligent CO₂ geological storage and utilization system, and exploring diversified CCUS industry development models.

When thermal power units employ amine-based carbon capture, electro-carbon coupling exists. To enhance the load flexibility tracking performance of decarbonized units, a variable-load control strategy based on electric-carbon coordination is proposed. Using existing data, an electric-carbon coordinated control system model for drum boiler thermal power units was established through system identification. The response time scales of reboiler load to power generation load and carbon capture rate were analyzed. Based on this, a dual-control loop for power generation load was designed, incorporating both decarbonization steam extraction and fuel quantity regulation. Furthermore, to address the effect of long time scales on carbon capture rate, the transient quantities of reboiler load variation throughout the process were reconstructed, and a flexible power generation load control method based on electric-carbon synergy was proposed. Simulation tests on a 300 MW unit demonstrated that, compared with the conventional coordinated control strategies, the proposed strategy ensures performance metrics for thermal load and carbon capture rate while improving both the load variation control rate and AGC performance metrics by an average of 100% or more.

Photovoltaic power generation makes full use of the advantages of solar energy, which is green, clean, widely distributed, and abundantly available. However, the efficiency of photovoltaic (PV) modules often decreases as the operating temperature increases, severely affecting system performance. To address this issue, this paper experimentally investigates the cooling effect of phase change materials (PCM) with Y-shaped fins on PV cells. The study focuses on analyzing the effect of structural parameters such as the branching angle, position length, and length ratio of the Y-shaped fins on the system’s thermoelectric performance. The results show that, comparing with the system without fins, the system with Y-shaped fins has an average increase of 0.37% in photoelectric conversion efficiency, and the average melting rate of paraffin increased by 21.52%. The position length has the greatest impact on the melting rate. When the branching angle is 60°, the length ratio is 2, and the position length is 0, the Y-shaped fin can achieve the best temperature uniformity inside the cavity. By coupling Y-shaped fins with PCMs for PV cell cooling, this research aims to address practical application challenges such as uneven melting, internal temperature stratification, excessive local temperatures, and hotspots caused by the poor thermal conductivity of PCMs.

To study the effect of inlet temperature and flow step changes on dynamic performance of supercritical carbon dioxide (S-CO₂)/lead-bismuth coupled heat exchanger, a segmental model was established for numerical simulations. Based on the simulation results, a transfer function model was developed and validated to quantitatively assess the effect of inlet step disturbances on the cold-side outlet temperature. The results show that, under inlet temperature step disturbances, the heat exchanger responds quickly, but the temperature field changes with a smaller amplitude. The time constant for the temperature step change at the hot-side inlet is 22.1 s. When the cold-side inlet temperature decreases by 50 K, the temperature at the midpoint of the heat exchanger only drops from 795.23 K to 793.17 K. Under flow step disturbances, the heat exchanger responds with a delay, but the temperature field changes with a larger amplitude. The time constant for the cold-side inlet flow step change is 30.08 s. When the cold-side flow increases to 0.002 kg/s, the temperature at the midpoint of the heat exchanger drops from 795.23 K to 779.08 K. The transfer function established in this study shows good agreement with the results from the segmental model. The findings provide useful insights for the operational strategy of intermediate heat exchangers in the S-CO₂ power cycle and the lead-bismuth fast reactor coupling system.

Micro-nano particle doping is an important method for the modification of molten salt thermal storage materials. By taking a binary carbonate molten salt mixture of 40Li₂CO₃-60Na₂CO₃ (mass fraction) as the base molten salt, CuO and CuCl₂ as the dopants, three composite molten salt phase change thermal storage materials, namely CuO-Li₂CO₃-Na₂CO₃, CuCl₂-Li₂CO₃-Na₂CO₃, and CuO-CuCl₂-Li₂CO₃-Na₂CO₃, were re prepared separately using a high-temperature melting method. Moreover, the thermal properties of these compounds were tested, and the effects of additives on the modification of binary carbonate molten salts and composite molten salt phase change thermal storage materials were investigated. The results show that, the melting point of the Li₂CO₃-Na₂CO₃ molten salt with 0.24% CuO addition decreased by 5.2 ℃, the latent heat of phase change decreased by 98.1 J/g, the average specific heat capacity of the solid phase decreased by 0.39 J/(g·℃), and the average specific heat capacity of the liquid phase decreased by 0.77 J/(g·℃). The upper limit of the operating temperature increased by 4 ℃. For the Li₂CO₃-Na₂CO₃-CuCl₂ molten salt with 0.06% CuO addition, the melting point increased by 9.6 ℃, the latent heat of phase change decreased by 15 J/g, the average specific heat capacity of the solid phase increased by 0.07 J/(g·℃), and the average specific heat capacity of the liquid phase increased by 0.12 J/(g·℃). The upper limit of the operating temperature increased by 17 ℃. Both molten salts exhibited improved thermal conductivity performance after the addition of CuO.

The combustion characteristics of coal-fired power plant boilers co-firing ammonia and its impact on the boilers are reviewed, aiming to provide theoretical and practical basis for large-scale application of ammonia as an alternative fuel to coal. By systematically reviewing existing literatures, the study examines the fundamental characteristics of ammonia combustion, flame propagation, flame morphology, and their effects on heat transfer, heat surface safety, boiler efficiency, and exergy efficiency of coal-fired boilers. The study also explores combustion enhancement methods such as oxygen-enriched combustion, preheated combustion, and hydrogen-assisted combustion. The results indicate that, co-firing ammonia can mitigate issues like ash deposition, slagging, wear, and high-temperature corrosion on heating surfaces, but it increases the acid dew point of flue gas, potentially exacerbating low-temperature corrosion. Co-firing ammonia increases the irreversibility of the combustion process, leading to higher furnace losses, although oxygen-enriched combustion can mitigate these losses. While there is substantial research on ammonia co-firing with small molecule gaseous fuels, there is limited study on its co-firing with large molecule solid hydrocarbons like coal. The effect of ammonia blending combustion on boiler heat transfer, heating surface safety, and boiler efficiency is significant. The decrease in flame temperature, reduction in flue gas soots, and changes in flue gas composition can affect heat transfer efficiency and heating surface conditions. Attention should be paid to low-temperature corrosion and unburned ammonia emissions. Ammonia blending combustion is an effective low-carbon combustion technology, but its application in large utility boilers still faces many challenges. It requires further in-depth research on combustion mechanisms and practical application effects to optimize combustion equipment and improve system efficiency.

To enhance the cybersecurity protection capabilities of power monitoring systems, a security reinforcement middleware for interal unidirectional safety isolating device for electric power has been designed. This middleware integrates compatibility adaptation, file format correction, encryption authentication, load balancing, and access control functions, addressing the security issues such as business system compatibility, hardware failures, and plaintext communication faced by isolation devices during the upgrading and reinforcement process. It enhances the security control of data transmission channels in power monitoring systems and achieves an “efficient and unobtrusive” and “standardized” security upgrade and reinforcement of the isolation devices. This middleware has been successfully applied to all thermal power, hydropower, and new energy power stations of Huaneng Group, strengthening the cybersecurity boundary protection capabilities of critical information infrastructure in power monitoring and ensuring the information security of power production.