Clean Use Of Coal Research Articles

Co-pyrolysis of subbituminous coal and lignin at isothermal and non-isothermal conditions: A ReaxFF molecular dynamics simulation

Understanding the co-pyrolysis behavior of sub-bituminous coal and lignin not only contributes to the efficient and clean use of coal but also enables low carbon emissions. The behavior and product evolution of pure coal, pure lignin, and co-pyrolysis systems under isothermal and non-isothermal conditions were explored using reactive force field molecular dynamics (ReaxFF MD) simulation. Through multiple isothermal simulation processes, the co-pyrolysis system showed an inhibition effect, promoting the generation of heavy compounds and inhibiting the generation of tar and gas. The inhibition effect at 2400 K was the most significant in the pyrolysis period. A similar phenomenon was found in the non-isothermal pyrolysis process at 2 K/ps. In addition, the H2 yield under non-isothermal conditions was lower than the calculated value. By distinguishing the same element from different sources, there were three types of H2 (Hcoal2, HcoalHlignin, and Hlignin2). Subsequently, the H atoms in lignin prefer to produce H2 than that in coal during co-pyrolysis. Finally, we further explored the evolution behavior of the configurations during the pyrolysis of non-isothermal coal and lignin systems. These findings enrich the theoretical information on the interaction between coal and lignin, providing the behavior of Hcoal and Hlignin atoms in the co-pyrolysis system.

Enhancing the arch-fired low-NOx performance with a throat overfire air for lowering NOx and hopper overheating

Upon the background of China's dual-carbon energy and environment strategies and the requirements of green and sustainable development in the new era, how to gradually reduce coal consumption while at the same time enhance the efficient and clean use of coal and reduce pollutant emissions is attracting more and more attention. For a 600-MWe arch-fired furnace facing persistent challenges of high NO x output and an overheating risk in hopper as firing anthracite, a cascade-arched low-NO x and high-efficiency configuration (CLHC) was taken as an alternative to the existing multiple-injection and multiple-staging combustion technique (i.e., the MIMSCT, denoted as the reference furnace or technique in this study). In particular, along the furnace height the CLHC's overfire air (OFA) position in the burnout zone has an important influence on the low-NO x performance due to the shrunk furnace-arch space and a short upper furnace. Aiming at evaluating the OFA-location effect and confirming the CLHC in resolving the above problems, industrial-scale experiments and modeling were performed in the reference furnace and thereafter, the low-NO x characteristics with the CLHC was simulated considering three different OFA locations of the upper-furnace OFA, throat OFA, and arch OFA. In the OFA-location elevated order, the blending position of OFA and the main upward gas first lowered and then elevated, while the OFA penetration, overall combustion performance, and major low-NO x accomplishment indexes related to NO x yield and burnout loss initially improved but then deteriorated. As a result, the medium throat OFA presented the optimal low-NO x merit among the three setups, with the unburnt combustible of 5.3% in fly ash alongside NO x yield of 660 mg/m3 (O2 = 6%), respectively. By comparison to the reference technique, the CLHC gained a 30% NO x reduction ratio without affecting burnout and greatly relieved the hopper overheating issue via reducing sharply its temperatures by 400 K, thereby confirming the CLHC's viability. This study provided guidance on the safe furnace operations and reduction of pollutant emissions, benefiting the efficient and environmentally friendly usage of low-quality coals in industrial-scale furnaces.

Facilitation of coke gasification by coking wastewater and its degradation properties in thermochemical reactions.

The thermochemical reaction between coking wastewater and gasification-coke is a new way to achieve efficient and clean use of coal and solve the problem of coking wastewater treatment in the Gansu Longdong region. To further investigate the thermochemical reaction characteristics of coking wastewater and gasification-coke, this paper explores the effect of coking wastewater on syngas production from coke gasification at 1000 °C, the degradation effect of organic pollutants in coking wastewater, the thermochemical reactivity of gasification-coke, and the reasons why wastewater promotes coke gasification and wastewater degradation. The results showed that the thermochemical reaction of coking wastewater with gasification-coke not only facilitates the improvement of syngas yield and low-level calorific value but also improves the thermochemical reactivity of gasification-coke. Notably, phenol in coking wastewater plays a major role in promoting the gasification of gasification-coke. During the thermochemical reaction, the organic pollutants in the wastewater were effectively degraded, the degradation rate of CODCr reached more than 85%, and the degradation of organic pollutants reached more than 75%. Phenol water and coking wastewater can not only improve the dispersion of the ash phase on the surface of gasification-coke, effectively inhibiting the sintering and agglomeration of the ash phase in gasification-coke, but also change the type and number of organic functional groups in gasification-coke. Therefore, coking wastewater can promote the gasification of coke. The thermochemical reaction between coke wastewater and gasification-coke can simultaneously promote coke gasification and the degradation of coke wastewater and achieve the resourceful use of coke wastewater.

Kishida's Climate Policy and Opportunities for U.S.-Japan Cooperation

executive summary: This essay summarizes key trends and drivers in Japan's climate policy, with an emphasis on the acceleration of commitments and policies that has taken place during the Suga and Kishida cabinets, and reviews the policy implications. main argumentJapan's climate policy development has been dominated by a technocratic policy triangle that includes the Ministry of Economy, Trade and Industry; politicians within the dominant Liberal Democratic Party; and industry. This triangle has generated cautious policymaking characterized by gradualism and a focus on the long-term viability of existing industrial assets. However, the acceleration of climate policy under the Suga and Kishida governments of the last two years has been driven by political leadership in response to both competition in East Asia and overtures from the Biden administration. Most crucially, Japan's stepped-up commitments include a comprehensive vision of economic and energy security that views the current competition over green technology in the Indo-Pacific as crucial for future economic competitiveness. Under the Green Transformation (GX) strategy, industrial policy is back. policy implications • Energy security and industrial competitiveness are driving the new Japanese approach to climate policy. In the context of a tighter geopolitical environment in the Indo-Pacific area, this approach opens more avenues for cooperation with key allies and partners. • The Kishida cabinet is emphasizing several key policy sectors: solar energy, nuclear energy revival, ammonia and hydrogen innovation in combination with continued clean coal use, and electric vehicles. • Japan's climate policy approach will have a strong focus on innovation, competition, and industrial renewal, focusing as much on the supply side as the demand side.

Comparative study on the electrochemical performance of coals and coal chars in a molten carbonate direct carbon fuel cell with a novel anode structure

Molten carbonate direct carbon fuel cells (MC-DCFCs) allow the efficient and clean use of coal. In this study, a novel anode structure is designed, and the performances of six coal-based fuels are investigated in MC-DCFC. The mechanisms of performance differences are investigated, as well as the effect of operating temperature on performance. The results reveal the fuel cell performance in the following order: meagre coal (109.8) ≈ bituminous coal (108.7) > bituminous coal char (98.1) > lignite coal (83.7) > lignite coal char (71.3) > meagre coal char (53.2) in mW cm−2. Coal performs better because of its high carbon content, high volatile content, rich oxygen-containing functional groups, larger specific surface area, stronger thermal reactivity, and other factors. The electrochemical reactivity of coal fuel increased with higher reaction temperatures and varied throughout the temperature ranges. This study implies that using coal fuel to commercialize MC-DCFC could be a realistic alternative.

Synergistic integration of molten hydroxide direct carbon fuel cell and Stirling heat engine for efficient and clean coal use

To reuse the exhaust heat produced by molten hydroxide direct carbon fuel cells (MHDCFCs), a new combined system mainly composed of an MHDCFC, a regenerator, and a Stirling heat engine (SHE) is theoretically integrated for fuel-to-power efficiency enhancement. Mathematical formulas of the performance indicators for the combined system are derived based on the first and second laws of thermodynamics, from which the feasibility and effectiveness of the combined system are evaluated from both energetic and exergetic viewpoints. Moreover, the optimum working regions of the combined system are further specified by using a multi-objective function paying equal attention to both efficiency and power output. Results show that SHEs can be effectively acted as bottoming cycles for MHDCFC for additional mechanical power production. Numerical calculations indicate that the maximum power density and its corresponding energy efficiency and exergy efficiency of the proposed system are, respectively, about 97.6%, 97.1% and 99.2% greater than that of the single MHDCFC. Furthermore, extensive parametric studies show that increasing working temperature, volume ratio, hot-side working substance temperature or mean pressure is beneficial for the overall system performance, while increasing reactor compartment width may degrade the overall system performance.

Probe into the Development Potentiality of Chinese Electric Power

<p>After 70 years of development, especially <span style="font-family: 'Times New Roman';">after</span> the 18th National Congress of the CPC, the development of China’s electric power industry has entered a critical stage of transformation, adjustment and transformation. The high quality development of electric power industry is a kind of development that reflects the new development concept, which must be realized through qualitative change, efficiency change and power change. The core of high-quality development in the power industry is to improve efficiency. Reform, open and innovation are the core of efficiency. China’s power industry high-quality development of opportunities and challenges coexist. People’s desire for a better life, continuous improvement of electrification levels, clean use of coal, energy conversion, multi-energy complementarity, market reform of the power system, “Belt and Road Initiative” and electric heating for electric vehicles are among the policies for power and other energy alternatives in China. T<span style="font-family: 'Times New Roman';">here is a</span> great opportunity for industrial development. However, it is also faced with the pressure <span style="font-family: 'Times New Roman';">from the </span>large-scale clean transformation, <span style="font-family: 'Times New Roman';">and </span>the efficiency of the power system is not high enough<span style="font-family: 'Times New Roman';">. T</span>he power cost is not low, and the system mechanism is not perfect. Therefore, we must seize the historical opportunity of energy transformation to establish a high-quality green power system. We will deepen the reform of the electricity market and improve the systems and mechanisms for high-quality development of the power industry<span style="font-family: 'Times New Roman';">, to s</span>olve all kinds of contradictions in the development of electric power industry scientifically.</p>

Chinese cities exhibit varying degrees of decoupling of economic growth and CO2 emissions between 2005 and 2015

Summary Cities, contributing more than 75% of global carbon emissions, are at the heart of climate change mitigation. Given cities' heterogeneity, they need specific low-carbon roadmaps instead of one-size-fits-all approaches. Here, we present the most detailed and up-to-date accounts of CO2 emissions for 294 cities in China and examine the extent to which their economic growth was decoupled from emissions. Results show that from 2005 to 2015, only 11% of cities exhibited strong decoupling, whereas 65.6% showed weak decoupling, and 23.4% showed no decoupling. We attribute the economic-emission decoupling in cities to several socioeconomic factors (i.e., structure and size of the economy, emission intensity, and population size) and find that the decline in emission intensity via improvement in production and carbon efficiency (e.g., decarbonizing the energy mix via building a renewable energy system) is the most important one. The experience and status quo of carbon emissions and emission-GDP (gross domestic product) decoupling in Chinese cities may have implications for other developing economies to design low-carbon development pathways.

Process simulation of coal-direct chemical looping gasification for syngas production

The coal gasification process is used in the commercial production of syngas as a means toward the clean use of coal.

Clean coal use in China: Challenges and policy implications

Energy consumption in China is currently dominated by coal, a major source of air pollution and carbon emissions. The utilization of clean coal technologies is a likely strategic choice for China at present, however, although there have been many successes in clean coal technologies worldwide, they are not widely used in China. This paper examines the challenges that China faces in the implementation of such clean coal technologies, where the analysis shows that those drivers that have a negative bearing on the utilization of clean coal in China are mainly non-technical factors such as the low legal liability of atmospheric pollution related to coal use, and the lack of laws and mandatory regulations for clean coal use in China. Policies for the development of clean coal technologies are in their early stages in China, and the lack of laws and detailed implementation requirements for clean coal require resolution in order to accelerate China's clean coal developments. Currently, environmental pollution has gained widespread attention from the wider Chinese populace and taking advantage of this opportunity provides a space in which to regain the initiative to raise people’s awareness of clean coal products, and improve enterprises’ enthusiasm for clean coal.

Heat transfer modelling of global anthropogenic warming

A simple heat transfer model is developed considering thermal wastes while applying thermodynamic engine phenomenon as well as principles of flow along paths of least resistance to explain the global anthropogenic warming (GAW) of atmospheric mass. This Neale’s GAW model indicates that the effect of water vapour in radiation forcing is considerable. It has not been looked at from the simple thermodynamic point of view because measurements of absolute global humidity are more elusive than measurements of non-condensable carbon dioxide, as well as cloud effects. The elegance of this heat transfer model is that it is very simple and far less complicated than meteorological modelling. This model notes that GAW can be minimised not by choosing one fuel over another but only by improving energy efficiencies of processes for power generation or material production. The importance of nanotechnology in improving process energy efficiency and facilitating clean coal use is worth noting.

Feasibility analysis and policy recommendations for the development of the coal based SNG industry in Xinjiang

Based on China's basic national energy conditions of “abundant coal and scarce gas reserve”, the development of the coal based SNG industry is considered to be an effective way to solve the conflict between the supply and demand of natural gas and an important direction in the clean use of coal. Xinjiang is rich in coal resources and is listed by the central government as one of the main bases of the coal based SNG industry. Nearly 70% of the coal based SNG projects are being conducted in Xinjiang, with the goal to take advantage of the lower coal price in Xinjiang to promote the development of the coal based SNG industry. However, the coal based SNG industry is subject to the constraints of pollution, immature technology, poor economic returns, water resources and many other factors. Therefore, the development of the coal based SNG industry should be limited to industrial demonstration. Taking into account China's energy security and environmental governance, once the technology matures, the development prospect of the coal based SNG industry is broad.

A ‘must-go path’ scenario for sustainable development and the role of nuclear energy in the 21st century

An increase in the world population has accelerated the consumption of fossil fuels and deepened the pollution of global environment. As a result of these human activities, it is now difficult to clearly guarantee the sustainable future of humankind. An intuitional ‘must-go path’ scenario for the sustainable development of human civilization is proposed by extrapolating the human historical data over 30 years between 1970 and 2000. One of the most important parameters in order to realize the ‘must-go path’ scenario is the sustainability of energy without further pollution. In some countries an expanded use of nuclear energy is advantageous to increase sustainability, but fast reactor technology and closed fuel cycle have to be introduced to make it sustainable. In other countries, the development of cost-effective renewable energy, and the clean use of coal and oil are urgently needed to reduce pollution. The effect of fast nuclear reactor technology on sustainability as an option for near-term energy source is detailed in this paper. More cooperation between countries and worldwide collaboration coordinated by international organizations are essential to make the ‘must-go path’ scenario real in the upcoming 20 or 30 years.

Hydrogen production from coal gasification for effective downstream CO 2 capture

The coal gasification process is used in commercial production of synthetic gas as a means toward clean use of coal. The conversion of solid coal into a gaseous phase creates opportunities to produce more energy forms than electricity (which is the case in coal combustion systems) and to separate CO 2 in an effective manner for sequestration. The current work compares the energy and exergy efficiencies of an integrated coal-gasification combined-cycle power generation system with that of coal gasification-based hydrogen production system which uses water-gas shift and membrane reactors. Results suggest that the syngas-to-hydrogen (H 2) system offers 35% higher energy and 17% higher exergy efficiencies than the syngas-to-electricity (IGCC) system. The specific CO 2 emission from the hydrogen system was 5% lower than IGCC system. The Brayton cycle in the IGCC system draws much nitrogen after combustion along with CO 2. Thus CO 2 capture and compression become difficult due to the large volume of gases involved, unlike the hydrogen system which has 80% less nitrogen in its exhaust stream. The extra electrical power consumption for compressing the exhaust gases to store CO 2 is above 70% for the IGCC system but is only 4.5% for the H 2 system. Overall the syngas-to-hydrogen system appears advantageous to the IGCC system based on the current analysis.

Coal to Liquid Fuels by Gasification and the Associated Hot Gas Cleanup Challenges

Coal is the most important energy source in China. The utilization of coal should consider not only the efficiency but also the reduction of pollutants and CO2 emission. Compared with coal utilization by conventional combustion, the route to different products via coal gasification is recognized as the most advanced technological concept for clean coal use. The products from coal gasification cover the whole product spectra currently obtained from oil. This paper summarizes recent progress made in the Institute of Coal Chemistry, Chinese Academy of Sciences in the field of coal gasification, mainly in the gasification using an ash agglomerating fluidized bed gasifier together with the gas cleanup challenges, Fischer-Tropsch synthesis with an iron-based catalyst and a slurry bed reactor, higher alcohol synthesis, and the one-step dimethyl ether synthesis from coal-based syngas.

Studies on the Production of Ultra-clean Coal by Alkali-acid Leaching of Low-grade Coals

The use of low-grade coal in thermal power stations is leading to environmental pollution due to the generation of large amounts of fly ash, bottom ash, and CO2 besides other pollutants. It is therefore important to clean the coal before using it in thermal power stations, steel plants, or cement industries etc. Physical beneficiation of coal results in only limited cleaning of coal. The increasing environmental pollution problems from the use of coal have led to the development of clean coal technologies. In fact, the clean use of coal requires the cleaning of coal to ultra low ash contents, keeping environmental norms and problems in view and the ever-growing need to increase the efficiency of coal-based power generation. Therefore this requires the adaptation of chemical cleaning techniques for cleaning the coal to obtain ultra clean coal having ultra low ash contents. Presently the reaction conditions for chemical demineralization of low-grade coal using 20% aq NaOH treatment followed by 10% H2SO4 leaching under reflux conditions have been optimized. In order to reduce the concentration of alkali and acid used in this process of chemical demineralization of low-grade coals, stepwise, i.e., three step process of chemical demineralization of coal using 1% or 5% aq NaOH treatment followed by 1% or 5% H2SO4 leaching has been developed, which has shown good results in demineralization of low-grade coals. In order to conserve energy, the alkali-acid leaching of coal was also carried out at room temperature, which gave good results.

「環境調和的な石炭利用」石炭の資源・環境制約へのＪＣＯＡＬの取り組み

The world produced over 6.7 billion tons of coal in 2008. Coal is one of the world's most important resources of energy, generating almost 40% of electricity worldwide. The world relies on coal for about 30% of the primary energy consumption in the Asia Pacific region. The largest coal producing countries are not confined to one region. Coal will continue to play a key role in the world's energy mix, with demand in certain regions, such as Asian countries, set to glow rapidly. The world consumption of coal can have a significant impact on the environment. Minimizing the negative impacts of human activities-including coal utilization- is a key global priority. Essentials to continue the clean use of coal are economically efficient and stable supply.It is also important to evaluate non-conventional type resources such as low rank coal and Coal Bed Methane/Coal Mine Methane, to raise an increase of the amount of the resources and the resources recovery rate.

The Power-Supply Control System in the Device of Acetylene Production by H-Plasma Pyrolysis Coal

The device of acetylene production by hydrogen (H-) plasma pyrolysis coal is examined and developed not only for studying the application of low temperature plasma but also for studying the clean use of coal. The power-supply control system is used to ensure supplying a steady energy to generate and maintain the plasma electric arc of the device. The hardware configuration and the software design of the system are described in this paper. Verified by experiments, this system can meet the requirements of real-time performance, reliability and extensibility for the device.

03/01622 Program for investigation, development and presentation of novel technologies for ecologically clean use of coal: Grinbaum, M. Elektricheskie Stantsii, 2002, 1, 72–81. (In Russian)

03/01622 Program for investigation, development and presentation of novel technologies for ecologically clean use of coal: Grinbaum, M. Elektricheskie Stantsii, 2002, 1, 72–81. (In Russian)

TECHNOLOGICAL COMPETENCIES AND COMPETITIVE ADVANTAGE IN THE SPANISH ELECTRICITY INDUSTRY: NEW CHALLENGES, NEW TOOLS

Recently, the electricity industry in Spain has experienced a deep transformation, aimed to improve the degree of concurrence between the operating firms. This change must be explained in the framework of the regional integration of markets with an European scale. The European Union is shaped as a relevant region in the world energy (and specifically, in electricity) market. Facing this change, the Spanish electricity firms must adopt a wider business vision, to cope with all the aspects of the new competitive environment in order to obtain business success. Firms, following the resource-based view, must generate and strengthen the competitive advantage derived from its core competencies. Those competencies, that constitutes the base for the inter-firm heterogeneity, are created (and evolve) from several mechanisms of organisational learning. Our research tries to show what the business vision of the Spanish electricity firms is, based on the efficient management of its personal, technological and organisational competencies. We have focused on technological competencies, because, in a more competitive scheme, they can support the sustained competitive advantage of the firm. So, we develop a model based on the Strategic Matrix of Technological Competencies (SMTC). The model is tested with a sample of 20 Spanish electricity firms (representing 71.25% of the industry total turnover in 1996). That matrix combines, in a dynamic sense, several scenarios and strategic business units in order to determine the critical technological competencies that the firm must master in each economic situation. The empirical analysis developed concludes (for the firms in the sample), among other issues, the existence of statistical relationships between certain technological competencies (as "Clean Use of Coal", "Advanced Technologies for Control and Communication", and "Electricity Transmission Technologies"), and several sources of competitive advantage (as the "The firm must difficult its resources' imitability"). In conclusion, facing the new competitive environment (in Spain and in the EU), technological competencies are considered by those firms as sources of competitive advantage. These competencies evolves using several organisational learning systems adopted by the firm. In this changing environment, the SMTC can be a relevant tool for the strategic management of the firms in the electricity industry.