Coal-fired Power Industry Research Articles

Перспективы развития угольной энергетики Монголии

Перспективы развития угольной энергетики Монголии

Study on Field-scale of CO2 Geological Storage Combined with Saline Water Recovery: A Case Study of East Junggar Basin of Xinjiang

Xinjiang is the major energy production area, and one of the regions with the most serious water resources scarcity issues in China. In particular, the coal-fired power and coal chemical industry base in East Junggar Basin has faced severe carbon emissions and water shortages. Based on the 3D heterogeneous geologic model of the East Junggar Basin, the research of field-scale CO2 enhanced water recovery (CO2-EWR) was carried out to provide technical reference for the future field-scale CO2-EWR engineering practice in Xinjiang to solve the carbon emission and water shortage issues. The CO2-EWR technology can greatly relieve the reservoir pressure buildup, with a maximum cumulative CO2 injection and storage of 100 Mt (3 times more than CO2 Geological Storage only) and a maximum saline water production of 129.4 Mt (100 times more than saline water production only).

Coal-fired power industry water-energy-emission nexus: A multi-objective optimization

The Chinese government has launched a guideline to lead power plants to more suitable technological pathways for meeting the strict “ultra-low emission” (“ULE”) standards to reduce air pollution emissions of the coal-fired power industry. Considering the complex interrelations between water, energy and emission, a quantifiable method of choosing the feasible technology sets for 6 multi-objective optimizations goals (MOGs) in the concept of water-energy-emission nexus (WEEN) was developed in this study. The results showed that the 16 technology sets can meet the “ULE”, which could mitigate at least 72% of the current emissions at the cost of up to 17% increase of water/energy consumption. Specific technology sets were identified for 6 different MOGs with the coordinate consideration of WEEN. The comparisons among the 6 MOGs indicated that (1) the investment cost was not a vital factor in the optimizing procedures; (2) dust reduction was sensitive to the water/energy optimization goal due to the synergic dust removal effects of the desulfurization technologies; (3) the water for WEEN was easier to reduce than the energy for WEEN from the perspective of the tradeoffs of emissions. The identified 12 feasible technology sets for WEEN (-cost) would shed lights on more coordinately policy making process.

New Carbon Emissions Allowance Allocation Method Based on Equilibrium Strategy for Carbon Emission Mitigation in the Coal-Fired Power Industry

The carbon emissions from coal-fired power have become an increasing concern to governments around the world. In this paper, a carbon emissions allowances allocation based on the equilibrium strategy is proposed to mitigate coal-fired power generation carbon emissions, in which the authority is the lead decision maker and the coal-fired power plants are the follower decision makers, and an interactive solution approach is designed to achieve equilibrium. A real-world case study is then given to demonstrate the practicality and efficiency of this methodology. Sensitivity analyses under different constraint violation risk levels are also conducted to give authorities some insights into equilibrium strategies for different stakeholders and to identify the necessary tradeoffs between economic development and carbon emissions mitigation. It was found that the proposed method was able to mitigate coal-fired power generation carbon emissions significantly and encourage coal-fired power plants to improve their emissions performance.

Life cycle carbon emission modelling of coal-fired power: Chinese case

Carbon footprints are usually more conducive to doing comparative analysis or carbon management between different enterprises or different countries. Regarding how to accurately estimate the carbon footprint per kWh of coal-fired electricity, different studies can give different answers since there are no uniform system boundaries (e.g. the direct and indirect emission) or data sources, which hinders the carbon reduction management of the coal-fired power industry. Addressing this issue would improve the level of carbon management and carbon control in the coal-electricity industry. This paper develops a life cycle accounting model to analyze the carbon emissions of China's coal-fired power generation plants. We calculated the direct and embodied carbon emission of CO2 and CH4 from carbon emission and carbon reduction. Results reveal that the life cycle coal-fired carbon emissions are in line with the trend of coal consumption and electricity generation, and carbon emission of the life cycle is higher than direct emission of coal-fired power generation by 10%–13%, resulting in a net increase of 332 MtCO2e in 2016. Based on the systematic uncertainty analysis, we believe the estimates could be more accurate than the past researches. Finally, the paper provides three tiered approaches to improve the carbon management.

Investigation of water-energy-emission nexus of air pollution control of the coal-fired power industry: A case study of Beijing-Tianjin-Hebei region, China

Coal-fired power generation is water- and energy-intensive and is associated with high emissions. As a result, China has issued a strict emission policy ("ultra-low emission control") for the coal-fired power industry. This study investigated the water, energy and emissions nexus (WEEN), focusing on end-of pipe treatment technologies for the coal-fired power industry in the Beijing-Tianjin-Hebei region. The result revealed that the energy consumption for pollutant removal was 1.2 million tons coal equivalent (Mtce) for the 118 investigated plants in 2014. Of the energy consumed, 60%, 11% and 29% was used for SO2, NOx and dust removal, respectively. Water consumption for pollutant removal was 13% of total water consumption for electricity generation. The result implied that this policy could reduce SO2, NOx and dust emissions by 89%, 90%, and 88%, respectively, while consuming an average of 2% less energy and 8% more water as tradeoffs. Construction cost associated with implementing these technology changes could be as high as 5–14 billion yuan in total. The synergies and tradeoffs quantified in this study provide numerical information that could assist with making decisions on the most suitable technology sets for emission control with consideration of water, energy, emissions and cost.

India Is Overtaking China as the World\u2019s Largest Emitter of Anthropogenic Sulfur Dioxide

Severe haze is a major public health concern in China and India. Both countries rely heavily on coal for energy, and sulfur dioxide (SO2) emitted from coal-fired power plants and industry is a major pollutant contributing to their air quality problems. Timely, accurate information on SO2 sources is a required input to air quality models for pollution prediction and mitigation. However, such information has been difficult to obtain for these two countries, as fast-paced changes in economy and environmental regulations have often led to unforeseen emission changes. Here we use satellite observations to show that China and India are on opposite trajectories for sulfurous pollution. Since 2007, emissions in China have declined by 75% while those in India have increased by 50%. With these changes, India is now surpassing China as the world’s largest emitter of anthropogenic SO2. This finding, not predicted by emission scenarios, suggests effective SO2 control in China and lack thereof in India. Despite this, haze remains severe in China, indicating the importance of reducing emissions of other pollutants. In India, ~33 million people now live in areas with substantial SO2 pollution. Continued growth in emissions will adversely affect more people and further exacerbate morbidity and mortality.

An optimal production planning model of coal-fired power industry in China: Considering the process of closing down inefficient units and developing CCS technologies

National Development and Reform Commission and National Energy Administration have launched a series of policies on closing down small coal-power units, in order to reduce energy consumption and pollutant emissions. However, it is hard to change current situation in the short term since coal is still the domain source of power generation in China. Aiming at efficiently closing down the small power units, to create a power generation planning model with minimized costs needs to take both economic and technical aspects into account. In this paper, eight types of coal-fired generators are classified into three categories: Inefficient units; Efficient units; and Low-carbon units. This paper has developed a power generation planning model under multiple constraint conditions such as coal-power demand, total installed capacity, and carbon capture etc. Also, the model involves variable costs of CCS technology and contingency payments at the same time. This paper has applied the power generation planning model into China’s coal-fired power industry research during the period from 2016 to 2030. The results show that because the coal-power demand ends up with a drop following a rise, the total costs thereby shows a same trend. During the planning period, the fuel costs and the operation and maintenance costs decrease most obviously. Given the installed capacity, compared with the increase in the number of efficient units, the number of inefficient units shows a gradual decrease. The number of low-carbon units displays a slight increase. Since low-carbon units can capture and store 90% of their carbon emissions, the total carbon emissions from coal-fired power industry have significantly been reduced in their operation year. Thus, it is imperative to develop high efficiency and low-carbon units as they will be the major contributors to the sustainable development of the coal-fired power industry.

Allocation of emission permits for China’s power plants: A systemic Pareto optimal method

Allocation of emission permits (AEP) is an important issue because of its significant effects on environmental governance and operations management. However, whether AEP results can constantly maintain systemic Pareto optimality still remains unclear and has not been investigated adequately in prior literature. We attempt to fill this gap by dividing the AEP process into a pre-stage observation process and a two-stage regulatory scheme as motivated by recent real-world examples. We apply the characterizations of each stage’s state variables to build a conceptual AEP model based on the classical theory of data envelopment analysis (DEA). Considering different real-world scenarios, we extend this conceptual AEP model into three different AEP models: non-limited, uniform-limited, and heterogeneous-limited AEP models. The allocation schemes derived from each of these three models are proved theoretically to be systemic Pareto optimal in the corresponding scenarios. The advantages of our models over other AEP methods are real-world tractability, enforceability, and systemic Pareto optimality. We further conduct an empirical analysis on allocating SO2 emission permits among mainland China’s major million-KW coal-fired power plants using the proposed models. Results of our empirical study show that the heterogeneous-limited AEP model exhibits higher performance over the non-limited and uniform-limited AEP models. Thus, we suggest that the Chinese coal-fired power industry should employ the heterogeneous-limited AEP model in the practical allocation of SO2 emission permits.

A synthetical evaluation of developing low-carbonized coal-fired power technologies in China

This study is attempted to analyze the integrated effects of low-carbonized developments for Chinese coal-fired power industry in two cases by extending a hybrid energy-economic model. The first case is energy efficiency improvement without CCS introduction. The second case is direct carbon removal with CCS technology, while coal controlling policy scenario is set as a baseline for comparison. Here oxy-fuel combustion has been selected as the only carbon capture technology due to its great potential in commercialization. Then the ecological co-benefits, environmental benefits, macroeconomic impacts and water saving effects of CO2 abatement from Chinese coal-fired power industry are analyzed. Simulation results show that energy saving and coal controlling policy can create huge ecological, environmental and water saving benefits. However, coal controlling policy also will cause great macroeconomic losses. But due to extra energy consumption, the large-scale commercialization of oxy-fuel CCS technology if without CO2 reuse will cause certain decrease of GDP growth rate and increase water consumption in China. Only when combined with resource usage of the captured CO2, oxy-fuel CCS introduction in China can have some practical application value.

Influence of high-energy impact on the physical and technical characteristics of coal fuels

Currently, in the world’s large-scale coal-fired power industry, the combustion of pulverized coal is the most widely spread technology of combusting the coals. In recent years, the micropulverization technology for preparation and combustion of the coal has been developed in this field. As applied to the small-scale power industry, the method of combusting the coal in the form of a coal–water slurry has been explored for years. Fine coal powders are produced and used in the pulverized-coal gasification. Therefore, the coal preparation methods that involve high-dispersion disintegration of coals attract the greatest interest. The article deals with the problems of high-energy impact on the coal during the preparation of pulverized-coal fuels and coal–water slurries, in particular, during the milling of the coal in ball drum mills and the subsequent regrinding in disintegrators or the cavitation treatment of the coal–water slurries. The investigations were conducted using samples of anthracite and lignite from Belovskii open-pit mine (Kuznetsk Basin). It is shown that both the disintegration and the cavitation treatment are efficient methods for controlling the fuel characteristics. Both methods allow increasing the degree of dispersion of the coal. The content of the small-sized particles reground by cavitation considerably exceeds the similar figure obtained using the disintegrator. The specific surface area of the coal is increased by both cavitation and disintegration with the cavitation treatment producing a considerably greater effect. Being subjected to the cavitation treatment, most coal particles assume the form of a split characterized by the thermodynamically nonequilibrium state. Under external action, in particular, of temperature, the morphological structure of such pulverized materials changes faster and, consequently, the combustion of the treated coal should occur more efficiently. The obtained results are explained from the physical point of view.

Prospects for the development of coal-steam plants in Russia

Evaluation of the technical state of the modern coal-fired power plants and quality of coal consumed by Russian thermal power plants (TPP) is provided. Measures aimed at improving the economic and environmental performance of operating 150–800 MW coal power units are considered. Ways of efficient use of technical methods of NO x control and electrostatic precipitators’ upgrade for improving the efficiency of ash trapping are summarized. Examples of turbine and boiler equipment efficiency upgrading through its deep modernization are presented. The necessity of the development and introduction of new technologies in the coal-fired power industry is shown. Basic technical requirements for a 660–800 MW power unit with the steam conditions of 28 MPa, 600/600°C are listed. Design solutions taking into account features of Russian coal combustion are considered. A field of application of circulating fluidized bed (CFB) boilers and their effectiveness are indicated. The results of development of a new generation coal-fired TPP, including a steam turbine with an increased efficiency of the compartments and disengaging clutch, an elevated steam conditions boiler, and a highly efficient NO x /SO2 and ash particles emission control system are provided. In this case, the resulting ash and slag are not to be sent to the ash dumps and are to be used to a maximum advantage. Technical solutions to improve the efficiency of coal gasification combined cycle plants (CCP) are considered. A trial plant based on a 16 MW gas turbine plant (GTP) and an air-blown gasifier is designed as a prototype of a high-power CCP. The necessity of a state-supported technical reequipment and development program of operating coal-fired power units, as well as putting into production of new generation coal-fired power plants, is noted.

Economic Impacts of Wind and Solar Photovoltaic Power Development in China

Recently, wind and solar PV power industries have entered a stage of large-scale development in China. In this study, scenarios and an input-output model are built to assess the economic impacts of wind and solar PV power development in China from 2016-2030. Compared to the reference scenario, more added value is brought about in the development scenario while both scenarios generate the same amount of electricity. In the development scenario, the quantitative analysis implies that the added value brought about by wind and solar PV power industry, directly and directly, is about 5.0 times in 2030 more than that in 2015. During 2016-2030, about 8674 billion RMB (1300 billion dollars) and 6949 billion RMB (1042 billion dollars) added value could be generated respectively by wind power industry and solar PV power industry, accounting for about 0.58% and 0.47% of GDP. In addition, the main interdependent industries stimulated by wind power industry or solar PV power industry are different from those stimulated by coal-fired power industry.

Analysis of Co-Effects on Air Pollutants and CO2 Emissions Generated by End-of-Pipe Measures of Pollution Control in China’s Coal-Fired Power Plants

China is now facing great challenges resulting from climate change and air pollution, driven by the processes of industrialization and urbanization. Greenhouse gas and air pollutant emissions produced by the coal-fired power industry represent approximately 70% of the total emissions in China’s industrial sector. In this study, 39 coal-fired power plants built in China between 2014 and 2015 were analyzed in regards to the co-effects oncarbon dioxide and air pollutant emissions generated directly and indirectly by end-of-pipe measures of pollution control. After completing the quantitative analysis with input data from 83units of power plants, we found that co-effects were positive only for air pollutant reductions through the implementation of desulfurization, denitrification, and dedusting measures, but co-effects were negative for carbon dioxide production because of the corresponding electricity use and chemical reactions that led to the increases in carbon dioxide emissions. We also performed an assessment of the synergistic coefficients to better understand the degree of co-effects. It will be important for researchers to take a comprehensive view of China’s coal-fired power plants and look for solutions that can maximize positive co-effects and achieve overall co-benefits of reductions in greenhouse gas emissions and air pollutants.

Costs and potentials of energy conservation in China's coal-fired power industry: A bottom-up approach considering price uncertainties

Energy conservation technologies in the coal-fired power sector are important solutions for the environmental pollution and climate change issues. However, a unified framework for estimating their costs and potentials is still needed due to the wide technology choices, especially considering their economic feasibility under fuel and carbon price uncertainties. Therefore, this study has employed a bottom-up approach to analyze the costs and potentials of 32 key technologies’ new promotions during the 13th Five-Year Plan period (2016–2020), which combines the conservation supply curve (CSC) approach and break-even analysis. Findings show that (1) these 32 technologies have a total coal conservation potential of 275.77 Mt with a cost of 238.82 billion yuan, and their break-even coal price is 866 yuan/ton. (2) steam-water circulation system has the largest energy conservation potential in the coal-fired power industry. (3) considering the co-benefits will facilitate these technologies’ promotions, because their break-even coal prices will decrease by 2.35 yuan/ton when the carbon prices increase by 1 yuan/ton. (4) discount rates have the largest impacts on the technologies’ cost-effectiveness, while the future generation level affect their energy conservation potentials most.

Co-benefits of local air pollutants and greenhouse gas reduction achieved by hydropower development in Xizang (Tibet) Autonomous Region, China

Hydropower development in Xizang (Tibet) Autonomous Region plays a vital role in co-control of local air pollutants and greenhouse gas (GHG) in China. According to emission factors of local air pollutants and GHG of coal-fired power industry in different hydropower service regions, we estimate the effect and synergy of local air pollutants and GHG reduction achieved by hydropower development in Tibet, examine the main factors constraining the effect and synergy, using correlation analysis and multiple regression analysis. The results show that: 1) During the period from 2006 to 2012, the effect of local air pollutants and GHG reduction achieved by hydropower development in Tibet decreased as a whole, while the synergy increased first and decreased afterwards. 2) The effect and synergy of local air pollutants and GHG reduction achieved by hydropower development in Tibet vary significantly across different hydropower service regions. The effect based on emission levels of Central China power grid (CCPG) and Northwest China power grid (NCPG) was more significant than that based on emission level of national power grid (NPG) from 2006 to 2012, and the synergy based on emission levels of CCPG and NCPG was also more significant than that based on emission level of NPG from 2010 to 2012. 3) The main factors constraining the effect and synergy based on emission levels of NCPG and CCPG included SO2 removal rate and NOx removal rate, the effect and synergy based on emission level of NPG was mainly influenced by net coal consumption rate. 4) Transferring hydropower from Tibet to NCPG and CCPG, and substituting local coal-fired power with hydropower can greatly help to co-control local air pollutants and GHG, transform the emission reduction pattern of the power industry and optimize energy structure.

Optimal CO2 abatement pathway with induced technological progress for chinese coal-fired power industry

This study attempts to analyze the integrated effects of carbon pricing in Chinese coal-fired power industry in two studied cases: with and without induced technological progress. Then several CO2 abatement pathways with different levels of carbon pricing are synthetically assessed for Chinese coal-fired power industry by extending a hybrid energy-economic model. Two types of autonomous technological progress such as industrial technology upgrading and autonomous energy efficiency improvement have been exogenously set for all economic sectors. One type of induced technological progress such as direct carbon removals is assumed to be introduced in coal-fired power industry, and its market share is endogenously calculated. Especially, oxy-fuel CCS technology is considered as a potential commercialized option for direct carbon removals. Then with different levels of carbon price setting for the newly increased CO2 emissions from coal-fired power industry, energy-economic indicators such as electricity cost, generation efficiency, economic growth, and CO2 emissions are comparatively analyzed for the choice of CO2 abatement pathway. Simulated results reveal that the upward trend of CO2 emissions cannot be changed within midterm if without induced technological progress. However, if with induced technological progress when carbon pricing is high enough, CO2 emissions could stop the upward trend, and even become decreasing accompanied by certain macroeconomic losses. When oxy-fuel CCS technology is introduced by charging for the newly increased CO2 emissions at 100 RMB2002 Yuan/t CO2, the induced CO2 abatement pathway of Chinese coal-fired power industry could be regard as optimal.

Immobilization of Heavy Metals by Solidification/Stabilization of Co-Disposed Flue Gas Desulfurization Brine and Coal Fly Ash

The coal-fired power industry in the United States faces growing needs to improve wastewater treatment and disposal practices, especially for wet flue gas desulfurization (FGD) systems. Zero liquid discharge (ZLD) treatment systems may be implemented, and one ZLD option is the coupling of brine concentration with solidification/stabilization (S/S). This S/S process could be achieved by co-disposing the concentrated FGD brines with coal fly ash (CFA) and Portland cement. S/S using bituminous CFA (BCFA) achieved good retainment (average 68–90%) of AsV, CdII, HgII, and SeIV in the toxicity characteristic leaching procedure (TCLP); however, poor retainment was observed for CrVI and SeVI. Separate experiments showed good sorption of AsV, CdII, HgII, and SeIV (average 56–100%) but poor sorption of CrVI and SeVI to S/S solids. Meanwhile, CrVI and SeVI retainment could be enhanced by addition of FeSO4 to the S/S mixture, likely due to reduction of these metals to lower oxidation states. Compared to BCFA, S/S using sub-bituminous CFA (SCFA) resulted in higher pH S/S solids and final TCLP leachate, which increased retainment of AsV, CdII, and SeVI. Apart from the pH impact on the process, AsV retainment was likely improved by the high Ca content of SCFA and SeVI retainment was improved by the incorporation of SeO42– in Friedel’s salt (AFm-Cl) by exchange with Cl–. Friedel’s salt was positively identified by X-ray diffraction in the SCFA S/S solids but not for the BCFA S/S solids. Even so, reduction of SeVI plus S/S is likely a better immobilization strategy than SeO42– substitution in the AFm phase because of higher stability under long-term landfill conditions.

Suitability analysis of China's energy development strategy in the context of water resource management

Coal is China's most important primary energy source, and is supporting the rapid economic growth going on there. However, the reverse geographical distribution of coal production and consumption results in a high cost of coal transportation and low efficiency of coal utilization. To ease the pressure on coal transportation, and to mitigate pollution in eastern coastal regions, China has kicked off a strategic west–east transfer of energy industries that requires the movement of coal power projects to the arid northwest regions. Under this strategic framework, the regulation is focused on “clean production”, “consumption reduction” and “reuse”, rather than conservation and protection of water resources. This study found that the northwest areas are unable to accommodate fully the planned scale of coal-fired power industry. Moreover, the subsidiary chemical industry, even if the scale of electric power development is determined according to the need for coal production, is problematic because the current water demand for the coal industry has exceeded “allowed water withdrawal”. Given limited water saving potential and the huge demand-and-supply gap, it is also unrealistic to balance water demand by combination of water conservation in the power industry and water right diversion from agriculture. This study on the synergies between energy and water is urgently needed, in order to provide scientific and technological support for laying out new energy industries. A critical change should involve conciliation of conflicting policies or plans before implementation begins.

Possibilities of creating a pure coal-fired power industry based on nanomaterials

A concept of distributed multigeneration during combustion of homogenized solid fuels with the addition of oxygen-enriched (to 30–50%) air is proposed. To implement this concept, application of medium-temperature δ-Bi2O3/Ag-nanocermet-based membranes is suggested under low pressures and sweeping of oxygen by the cleaned exit gas or the air. The primary product of the multigeneration is microsphere materials. The heat, the AC and the DC electric energy, the cleaned exit gases with a high CO2 content, and volatile elements adsorbed by the filters are the secondary products. To completely clean the exit gases, which is necessary to implement the distributed multigeneration, an array of successive passive plants is proposed. A thermoelectric module based on a BiTeSb-skutterudite nanocomposite is effective in generation of the DC electric energy at microthermoelectric power plants.