Green Energy and Resources最新文献

The co-disposal of solid waste by industrial kilns is presently attracting increasing attention. In this study, we investigate the co-disposal of solid waste, i.e. converter ash (CA), sintered ash (SA), blast furnace bag ash (BA), and municipal solid waste incineration fly ash (MSWIFA), under simulated blast furnace ironmaking conditions. The results show that it is feasible to use blast furnace to treat MSWIFA, but the stability of temperature field should be controlled in the process of co-disposal. With the increase of temperature, the conversion rate of NO decreased to 16.4%, and ZnFe₂O₄ became the main mineral composition, accounting for 75.53%. Corresponding to the flue gas corrosion condition of solid waste treatment, it is found that the corrosion resistance of the furnace material TH347H is better than 20G. Finally, based on the experimental data, the nested optimization algorithm of machine learning model is established to achieve the reverse output of optimal conditions. Overall, the study provides theoretical support and methodology guidance for the co-disposal of solid waste in blast furnaces in providing support for the further development of co-disposal of solid waste in industrial kilns.

This bibliometric analysis explores machine learning applications in biofuels and biodiesel research using Elsevier's Scopus database from 2013 to 2023. The research employs co-authorship, co-occurrence, citation, and co-citation analyses with fractional counting. Results indicate a significant rise in publications. Prominent funding agencies along this field include the National Natural Science Foundation of China, Brazil's Conselho Nacional de Desenvolvimento Científico e Tecnológico and the U.S. Department of Energy. Co-authorship analysis reveals contributions from 268 authors across 951 organizations in 71 countries, with strong collaboration in Asia. Citation analysis shows that 95% of articles have received at least one citation, with China and the United States leading in citation counts. This study highlights the interdisciplinary and collaborative nature of machine learning research in biofuels and biodiesel, driven by substantial contributions from key funding bodies and researchers worldwide.

Efforts to enhance the performance of thermoelectric generators (TEGs) in engine waste heat recovery have primarily focused on directly increasing energy conversion efficiency. Heat leakage can occur in many parts of a TEG. It is needed to develop a model to help researchers study this phenomenon and propose measures to reduce heat leakage. To address this gap, this study establishes and validates a computational fluid dynamic (CFD) and finite element (FE) coupled model based on a TEG prototype and its engine test bench. Unlike other models, this approach captures the intricate dynamics of heat propagation from the TEG via air gaps, encompassing conduction, convection, and radiation. Comprehensive analysis reveals that heat leakage accounts for approximately 11% of TEG power output loss. Ignoring the impact of heat leakage can lead to an overestimation of TEG power output. Key areas of heat leakage are identified, and numerical factors influencing this phenomenon are explored. Vertical TEG placement and optimal spacing between thermoelectric modules emerge as effective strategies for mitigating the impact of heat leakage on power output. Leveraging these insights, strategic thermoelectric module placement, vertical TEG orientation, and the application of thermal insulation materials to the heat exchanger are proposed as measures to enhance TEG power output by approximately 5%. The experimental and numerical results underscore the feasibility of optimizing TEGs from the perspective of heat leakage, a crucial aspect previously overlooked. These findings provide valuable insights for future TEG optimization endeavors, highlighting the importance of addressing heat leakage to maximize TEG performance.

The 21st century grapples with rising atmospheric CO₂ and anthropogenic solid waste. Ex-situ CO₂ mineralisation, converting CO₂ into stable carbonates via reacting with solid waste, shows great promise. However, concerns over the extensive consumption of chemicals urge sustainable and recyclable alternatives. This paper critically reviews recyclable chemicals for CO₂ mineralisation with various industrial solid wastes, and systematically examines their efficacy and reaction mechanisms. This study offers a comprehensive comparison of these chemicals and outlines clear future research directions.

The main findings are briefed below: first, we emphasize the pivotal role of trapping and recycling NH₃ gas for achieving effective and efficient CO₂ mineralisation using ammonium salts. Second, scaling up amines-based mineralisation could be feasible by replacing conventional strippers with mineralisation units. This transition is contingent upon resolving technical challenges such as amines' low leaching capacity and limited applicability to solid feedstocks that contain water-soluble Ca/Mg-bearing species. Third, leveraging their unique zwitterionic structures, amino acids may cater to diverse industrial needs and achieve a satisfactory CO₂ mineralisation efficiency with good recyclability at low temperatures. Fourth, a novel HCl regeneration technology known as ‘oxy-pyrohydrolysis,’ can achieve simultaneous CO₂ mineralisation and HCl regeneration in a single step. However, both amino acids-based mineralisation and oxy-pyrohydrolysis are nascent technologies requiring further research to ascertain their applicability and advance their development. Fifth, despite employing recyclable chemicals, operational costs of mineralisation could remain significant when high temperatures are used. Thus, energy optimization strategies should be explored, such as exploring low-energy consumption chemicals and integrating waste energy harvesting units. This review paper aims to delineate potential avenues for cost-effective CO₂ mineralisation facilitated by recyclable chemicals, thereby alleviating post-processing costs and environmental concerns associated with chemical residues.

To study the breakup process of fuel jets in air crossflow with a positive velocity gradient, the Volume of Fluid (VOF) method and adaptive grid technology are combined to simulate the two-phase flow of gas and liquid. A comparative analysis is conducted on the breakup and corresponding flow characteristics of direct fuel jets under uniform and positive velocity gradient airflow. The simulation results demonstrate that the morphological changes of the fuel column are caused by factors such as gas-liquid shear and asymmetric airflow vortices. The fuel jet undergoes primary breakup, which mainly contains columnar and surface breakup. The columnar breakup is dominated by Rayleigh-Taylor (R-T) instability, while the surface breakup is dominated by Kelvin-Helmholtz (K-H) instability. Compared with uniform flow, the expansion angle in the positive velocity gradient incoming flow increases by an average of 9.2%, and the wavelength of the surface wave increases by an average of 34%.

The catalytic fast pyrolysis process is a promising method for converting biomass waste into bio-oil, where the catalyst plays a crucial role in determining the yield and quality of the products. In this study, ultrafine iron nanoparticles were incorporated onto a montmorillonite substrate through the pyrolyzing coordinated polymer method to enhance liquid fuel production via catalytic pyrolysis of biomass waste. The catalyst showed a uniform distribution of iron on the montmorillonite surface, indicating that the incorporation was successful. Catalytic pyrolysis led to an increase in liquid yields and a decrease in gas product yields compared to direct pyrolysis. The highest bio-oil yield obtained was 56.9% during the catalytic pyrolysis of corncob, which was found to be particularly well-suited for the production of bio-oil. Furthermore, the proposed reaction pathway was based on identifying the composition of the bio-oil, which was further supported by quantum chemical calculations of chemical bond strength and the likelihood of free radical attacks. These findings demonstrate the potential of using montmorillonite-supported ultrafine iron nanoparticles to enhance bio-oil yield and quality in biomass pyrolysis processes.

CO₂ emissions have posed numerous global challenges, leading to an increasing consensus on the need for carbon neutrality in future development. CO₂ capture and energy storage technologies represent a critical step in the carbon neutrality journey. Calcium looping (CaL), a promising technology for both CO₂ capture and energy storage, holds significant potential in future carbon neutral technology strategies. In this paper, a comprehensive review of the application of CaL in CO₂ capture and thermochemical heat storage (TCHS) is offered to inform further advancements in this field. Firstly, a brief overview and analysis of the fundamental technical routes and principles underlying of CaL for CO₂ capture and TCHS are provided. Then, the research progress in the development of CaL-integrated systems for CO₂ capture and TCHS is subsequently reviewed, with the existing limitations and outlining future prospects for further development highlighted. Additionally, a comprehensive summary of the proposed improvements in the performance of calcium-based materials is presented, focusing on enhancing carbonation reactivity in the multiple cycles and improving sunlight absorption performance of calcium-based materials. Finally, based on the current status of CaL development, insights and perspectives on potential avenues for further technological advancement are offered. Solar-driven CaL is a promising avenue for future CaL development, calling for greater research efforts on optimizing relevant equipment and enhancing calcium-based materials for sunlight-driven CaL systems. In addition, the CO₂ in-situ conversion in the calcination stage of CaL is also a great potential direction for technological evolution.