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[Introduction] With the increasing demand for flexible peak shaving of thermal power units and the rapid development of information technology, thermal power enterprises are shifting from the traditional operation and management mode toward a cleaner, more efficient, reliable digital and intelligent mode. How to improve the intelligence, precision and reliability of coal-fired units in the flexible peak-shaving process has become a key issue of concern to those in the industry. [Method] Aiming at the deep peak shaving demand of the power system, this paper summarized the typical problems in the process of flexible peak shaving and analyzed the overall development of control theory applied to boilers in coal-fired units. Based on this, this paper conducted a comprehensive analysis of coal-fired boiler flexible peak shaving algorithm models and their applications based on intelligent control from four aspects: optimization control of boiler combustion performance, precise control of wide-load denitration, boiler operational energy efficiency control, and monitoring and diagnosis of main and auxiliary machinery equipment. [Result] On this basis, the research progress and application effects of intelligent control theory and models in the flexible peak shaving of coal-fired boilers are discussed in detail. [Conclusion] At present, based on the common problems in the flexible peak-shaving process of coal-fired boilers, it is necessary to improve the accuracy of basic data acquisition, promote the complementary integration of data and knowledge, and strengthen multi-objective optimization control and DCS control system optimization on the basis of the stable combustion ability improvement of the combustion organization method. At the same time, it is important to consider the dialectical optimization relationship between peak shaving economy and unit life, thereby providing intelligent and precise solutions to improve the flexible peak shaving capabilities of coal-fired boilers.

The acceleration of the energy transition is driven by current geopolitical conflicts and climate and environmental challenges. It is crucial for China to construct a new energy system adapting to these changing circumstances for the sustainability, security, and stability of the energy supply system. At present, fossil fuels still dominate the China’s energy demand. There are energy security issues due to lacking oil and gas resources, and new energy technologies. China will still maintain a high dependence on coal energy in short term, consequently, prompting the clean and efficient conversion of coal is vital for developing a new energy system. In this paper, the specific connotations and develop direction of the new energy system are identified, and then the development status, opportunities and challenges of the China’s coal chemical industry in the new era are presented, also the suggestions for improving the technology of clean and efficient coal conversion and the future development of coal chemical industry are put forward. The new era has endowed the new energy system with more connotations, that is the future energy system should be characterized by “safe and efficient, clean and low-carbon, diverse and synergistic, and intelligent and accessible”. In addition, the new era will put forward higher requirements for the clean and efficient development of the coal industry.Although China has made significant achievements in the clean and efficient conversion of coal, the key technologies still need some breakthroughs.Combining the systematic understanding of the relationship between the transformation and development of the coal industry and the “dual carbon” goals, and in the context of the construction of a new energy system, the promotion of clean and efficient coal conversion is of great significance for social and economic development and helping to achieve the “dual carbon” goals. The key lies in strengthening the basic research of relevant disciplines and specialties in this field, as well as the innovative development of clean and efficient coal conversion technologies.

[Display omitted] The nitrogen–nitrogen double bond between two molecules of 3,5-diamino-1 H -1,2,4-triazole is successfully constructed using a one-step electrochemical coupling method. The oxidation occurs selectively when the electrochemical parameters are properly adjusted to provide a yield of 45.77%. Subsequently, the oxidative coupling of this substrate with electrochemically generated hydroxy nickel oxide or sodium hypochlorite is verified. [ABSTRACT FROM AUTHOR]

Energy is the lifeblood of the national economy. At present, China’s energy development situation is severe, and its external dependence on crude oil and natural gas is relatively high. Considering the national conditions of coal, strengthening the clean and efficient utilization of coal is strategically significant; specifically, the clean and efficient coal transformation is an important approach. This study summarized the status quo of clean and efficient coal transformation, and analyzed the high-end, diversified, low-carbon, and intelligent development trend of the industry as well as the technology development trends that include coal transformation to clean fuels, coal transformation to bulk and special chemicals, and pollutant control in coal transformation. Moreover, the study analyzed the development challenges regarding water resources, carbon emissions, product competitiveness, and supporting policies, and proposed a development idea that is led by planning, demonstration, and innovation. The research suggests that the strategic position of clean and efficient coal transformation in the energy system should be clarified, the national coal-to-oil-and-gas strategic reserve mechanism should be established, financial credit and energy statistics policy support should be strengthened, and the scientific and technological innovation ability should be improved by building research and development platforms.

• Novel vacuum cracking purification for preparing ultra-pure metals was developed. • Simulations provided insight into the decomposition mechanism of compounds. • Product value of ultra-pure lead increased over 300% compared to raw material. • New process work cycle reduced from traditional 5–7 days to within 1 day. Ultra-pure lead has been confirmed as an irreplaceable metal material that is employed for new energy storage batteries, aerospace, nuclear industry. Ultra-pure lead has been scarcely produced because of the lack of large-scale low-cost production techniques, such that the development of the lead industry is significantly hindered. To develop a clean and efficient deep purification technology, a novel process invented preferentially employed vacuum dissociation as the core and cracks intermetallic compounds (e.g., Pb n Ag n and Pb m Cu m) in metallic lead lumps in a low-pressure system. Subsequently, the main metallic lead volatilized based on the difference in gasification characteristics. Impurities (e.g., Ag, Cu, and Sn) are separated and then enriched as residues. The contents of impurities (i.e., Cu, Sn, and Fe) in the vacuum gasification volatiles only reached 0.004 ppm, 0.012 ppm, and 0.006 ppm, and the impurity content of Ag was obtained as 0.06 ppm. Besides, the product lead conformed to the 6 N Pb standard, and the direct recovery rate of metallic lead exceeded 90%. Furthermore, metallic lead can be deeply purified by single vacuum gasification, which serves as a novel, clean, efficient, energy-saving, and low-carbon method for the preparation of ultra-pure lead. [ABSTRACT FROM AUTHOR]

Lead anode slime (LAS), a significant secondary resource, was utilized to separate andrecycle of rare and precious metals such as Te, Au, and Ag, along with essential metals Cu, Pb, and Bi. The conventional pyrometallurgical and hydrometallurgical processes generated hazardous waste, including high levels of As, Sb, smoke, heavy metal waste. Extraction of these key metals is both laborious and ineffective. A novel vacuum gasification technology was employed to explore the separation patterns and migration distribution principles of metal and oxide (MO) in LAS. The theoretical results of phase transition enthalpy change (ΔH), saturated vapor pressure, and molecular average free path investigated the gasification and volatilization potential of MO in LAS. Furthermore, the experimental results revealed separation behavior of MO. As and Sb were evaporated into the gaseous phase to facilitate their separation from other substances at 773 K. Pb and Bi behavior were similar to them at 823 K, As, Sb, Pb and Bi to enter the gaseous phase for the purpose of separation with Ag, Au, and Cu. By exploiting the differences of gasification specificity, it is possible to separate Ag, Au, Cu, and other elements at 1173 K, finally leading to the formation of Ag–Au–Cu alloys. • Vacuum gasification separation behavior of MO in LAS was revealed scientifically. • Volatilization potential and temperature of MO were explored by theoretical analysis. • Theory is main, experiment is supplemented, and the research period is shortened. • Separation and enrichment of Au, Ag, Te, and Sb have been achieved. [ABSTRACT FROM AUTHOR]

The crude bismuth obtained from the smelting of bismuth concentrate and bismuth-containing by-products contains 5%∼20% lead, which needs to be removed during the refining of crude bismuth. Due to the similar physical and chemical properties and metallurgical behavior of lead and bismuth, it is not easy to perform the separation by conventional methods. Although the conventional process of chlorinating crude bismuth to remove lead can meet the requirements of the refining process, the amount of chlorinated slag produced is large, and the safety of chlorine gas is difficult to control, making it difficult to achieve clean production. In this paper, single-factor experiments and semi-industrial experiments for the separation and purification of bismuth from Pb-Bi alloy were carried out by the continuous crystallization method, and the results showed that the bismuth content of Pb-Bi alloy increased from 90.24% to 98.98%, the direct yield of bismuth was 87.37%, the metal recovery rate was 99.84%, and the slag production rate was 0.62%. In comparison with existing processes and studies, the method is low-cost, clean, and efficient, has a wide treatment range, can be operated continuously, and can be easily industrialized and promoted. Theoretically, this method, combined with the process of vacuum distillation to treat Pb-Bi binary alloys with greater than 55.5% bismuth content, results in a 99.99% bismuth product.