With the increasingly serious problems of energy shortage and environmental degradation, countries around the world are actively developing safe, environmentally friendly, and renewable energy. Biomass energy has become an ideal substitute for fossil fuels due to its abundant reserves, good renewable performance, and zero carbon emissions. This paper discusses the importance and potential of biomass energy as a renewable energy source for China’s energy development, mainly including the three biomass conversion methods of physics, chemistry, and biology, seven utilization technologies, such as direct combustion, gasification, and pyrolysis, and five application approaches, such as biomass power generation, biomass gas fuel, biomass liquid fuel, and bio-based materials. This review systematically analyzes the challenges faced by China’s development of biomass energy and discusses the future development direction of biomass. The utilization of biomass resources should take a comprehensive and high-value path. China is actively looking for new energy utilization paths, and biomass energy has become a key measure to cope with carbon emission reduction, climate change, and ecological environment protection.

Biomass fluidized bed gasification technology has attracted significant attention due to its high efficiency and clean energy conversion capabilities. However, its industrial application has been limited by insufficient technological maturity. This paper systematically reviews the research progress on biomass fluidized bed gasification characteristics; compares the applicability of bubbling fluidized beds (BFBs), circulating fluidized beds (CFBs), and dual fluidized beds (DFBs); and highlights the comprehensive advantages of CFBs in large-scale production and tar control. The gas–solid flow characteristics within CFB reactors are highly complex, with factors such as fluidization velocity, gas–solid mixing homogeneity, gas residence time, and particle size distribution directly affecting syngas composition. However, experimental studies have predominantly focused on small-scale setups, failing to characterize the impact of flow dynamics on gasification reactions. Therefore, numerical simulation has become essential for in-depth exploration. Additionally, this study analyzes the influence of different gasification agents (air, oxygen-enriched, oxygen–steam, etc.) on syngas quality. The results demonstrate that oxygen–steam gasification eliminates nitrogen dilution, optimizes reaction kinetics, and significantly enhances syngas quality and hydrogen yield, providing favorable conditions for downstream processes such as green methanol synthesis. Based on the current research landscape, this paper employs numerical simulation to investigate oxygen–steam CFB gasification at a pilot scale (500 kg/h biomass throughput). The results reveal that under conditions of O₂/H₂O = 0.25 and 800 °C, the syngas H₂ volume fraction reaches 43.7%, with a carbon conversion rate exceeding 90%. These findings provide theoretical support for the industrial application of oxygen–steam CFB gasification technology.

This paper focuses on the critical role of long-duration energy storage (LDES) technologies in facilitating renewable energy integration and achieving carbon neutrality. It presents a systematic review of four primary categories: mechanical energy storage, chemical energy storage, electrochemical energy storage, and thermal energy storage. The study begins by analyzing the technical advantages and geographical constraints of pumped hydro energy storage (PHES) and compressed air energy storage (CAES) in high-capacity applications. It then explores the potential of hydrogen and synthetic fuels for long-duration clean energy storage. The section on electrochemical energy storage highlights the high energy density and flexible scalability of lithium-ion batteries and redox flow batteries. Finally, the paper evaluates innovative advancements in large-scale thermal energy storage technologies, including sensible heat storage, latent heat storage, and thermochemical heat storage. By comparing the performance metrics, application scenarios, and development prospects of various energy storage technologies, this work provides theoretical support and practical insights for maximizing renewable energy utilization and driving the sustainable transformation of global energy systems.

Wet fluidized bed granulation and coating processes have been widely used in the pharmaceutical and food industries. The complex gas–solid flow coupled with heat and mass transfer in such processes made it hard to form complete control over the apparatuses. To serve better design, scaling-up, and optimization of granulators and coaters, the underlying micro-scale mechanisms must be clarified. Computational fluid dynamics coupled with the discrete element method (CFD-DEM) provides a useful tool to study in-depth the gas-solid hydrodynamics of the granulation and coating processes. This review firstly introduced the fundamental theory of CFD-DEM from governing equations, force calculation, and coupling schemes. Then the application of CFD-DEM in simulating wet fluidized bed granulation and coating was presented. Specifically, the research focus and the role of CFD-DEM in resolving issues were discussed. Finally, the outlook on the development of CFD-DEM in the context of granulation and coating was given.

RM (red mud), which comes from the Bayer process, has a huge annual output and is harmful to the environment. Because of the high iron content in RM, the process of iron recovery from RM can reduce the amount of RM well and create economic benefits, so it is a promising process. The paper focuses on the review on the research of the iron recovery method from RM, which includes the physical recovery method, chemical recovery method and emerging recovery method. By comparing the advantages and disadvantages of these processes, it is concluded that the fluidized bed reduction is a promising process that can be rapidly applied to the industry, but it still needs more investigation to overcome the current technical difficulties in the near future.