Shenhua Group Research Articles

The optimal allocation and the evaluation of water resources carrying capacity in Shendong mining area

Coal mining has consumed a large amount of water resources in China, and the entire industrial chain of coal production has a larger consumption of water resources than the past especially in Shendong mining area. The water resources carrying capacity determines the scale of coal industry development. The previous research had been conducted at the national, provincial and municipal levels, but there were few studies on the water resources carrying capacity of coal mining areas. The Shendong mining area is located in the coal-rich and water-scarce western region, where precipitation is low and evaporation is high. As a water-scarce area, the development of Shendong mining area is inseparable from the support of coal resources and the rational use of water resources. Therefore, firstly, taking the Shendong mining area as the research object, this paper set high, medium and low scenarios according to the development goals of Shendong mining area, Shenhua Group and the plans of China. The gray forecast model was used to predict the water demand of the economic-social-ecological system of the mining area from 2020 to 2030 under different scenarios. Secondly, a multi-objective optimization model was established with the objective function to optimize the water resources allocation in Shendong mining area. Thirdly, based on the forecast and optimization results, a water resources carrying capacity evaluation model was constructed to evaluate the water resources carrying capacity of the Shendong mining area. Finally, based on the results, the suggestions for rational development and the utilization of water resources in the Shendong mining area were proposed.

몽골-중국 경제협력: 사회간접자본 구축과 에너지 협력을 중심으로

This paper analyzes the background and process of economic cooperation between Mongolia and China, which focuses on establishment of social overhead capital and energy supply facilities, Mongolian coal exports to China. It is based on analyses of government policy documents and related literature. Mongolia and China collaborated construction of internal road network in Mongolia, and transport network connecting from Mongolia to Northern China and Russia. The internal network in Mongolia sought to connect from Ulaanbaatar to neighboring regions, Erlianhaote and Ganchimaodu. The immediate benefit for Mongolia was the injection of much needed capital, skilled manpower and technology from China, all of which Mongolia lacked. Beyond this, Mongolia stood to gain from social overhead capital projects and energy supply facilities, as well as alleviate difficulties in the domestic transportation. Externally, the expansion of Mongolia’s transport network aimed to increase coal exports to China. In addition, Shenhua Group and Chinese central government are trying to increase exports of Mongolian coal to China by expanding the railway network connecting the Chinese border with the Tavan tolgoy coal mine.BRHowever, Mongolia has some difficulties in the process of cooperation with China. The downswing for Mongolia‘s role in the process of domestic road network construction was that all the work was done by Chinese companies, because Mongolian firms did not meet the selection criteria set by the Asia Development Bank and the European Bank for Reconstruction and Development. Accordingly, Mongolian local companies had a difficulty in participating in its own social overhead capital construction projects which gave fund from multilateral development banks. Additionally, Mongolia’s dependence on China intensified, as experienced Chinese companies took charge of all of these construction projects. To protect their trust, the Chinese companies completed their assignments on schedule. Their performance, however, did not transfer the technical skills to Mongolian workers, including training in construction technology, and operating of technical equipment. Furthermore, the expansion of the railway network connecting Mongolia, China and Russia was expected to delay, pending economic feasibility studies and verification. Despite these challenges, Mongolia was expected to continue cooperating with China, to ease difficulties in domestic transportation, stabilize energy supply and increase coal exports to mainland China.

Research progress on the protection and utilization technology of water resources for coal mining in China

Water shortage is a global problem, and China is one of the most water-scarce countries in the world. The reverse distribution of coal resources and water resources has made the protection and utilization of water resources for coal mining in China a major technical problem for the green development of coal. Western China has become the main coal-producing area, but the ecological environment in the region is fragile, the evaporation of water resources is large, and the evaporation loss after mine water discharge is the main reason for the current annual loss of 6 billion tons of mine water in coal mining in China. The technical progress and engineering application characteristics of the protection and utilization of water resources in coal mining are systematically analyzed. After nearly 20 years of technical exploration and engineering practice, Shenhua Group broke through the traditional concept, put forward the technical concept of mine water storage in the goaf for the first time, overcome the technical problems such as water source prediction, reservoir site selection, reservoir capacity calculation, dam construction, safety control and water quality assurance, and built a technical system for underground coal mine reservoirs. This technology has been fully implemented in the Shendong mining area, and will be promoted and applied in other mining areas in the western region, opening up an effective technical way for the protection and utilization of coal mining water resources.

Combustion comparison analysis on two typical Shenhua chars

Shenhun and Shitan coal are two types of typical Shenhua coals in Shenhua Group. To compare the ignition and burn out characters of this two coals, the pyrolysis process was adopted and Shenhun, Shitan two chars were acquired. The thermogravimetric method(TGA) was used to evaluate two chars combustion characters. Results show that the combustibility of Shenhun char samples are better than that of Shitan char samples. Both the two types of chars DTG peak temperature are approximate 600-650 °C, indicating an easier ignition tendency. The increase of pyrolysis temperature is adverse to the coke combustion. The DTG peak temperature in 700 °C pyrolysis temperature condition is 50 °C larger than that in 900 °C. In addition, the larger particle size is not beneficial to burn out. From the results in this paper, the particle size below 125 μm is recommended.

Optimization of water resource dispatching for Huanghua Port under uncertain water usage scenario

In recent years, large-scale coal bulk cargo ports have been vigorously promoting the green and intelligent construction, it is an important problem for them to manage water resources scientifically and effectively to realize energy conservation and environmental protection under uncertain circumstances. Taking Huanghua Port of Shenhua Group in China as an example, firstly, through a systematic review of the water resource dispatching infrastructures and production operations, the four-level water resource dispatching framework of Huanghua Port was obtained. Secondly, an uncertain multi-objective programming model is constructed to comprehensively consider the cost of water purchase, the energy consumption of water diversion, and the uncertainty of water usage. Then, an algorithm is designed according to the characteristics of the model. Finally, the applicability and effectiveness of the water resource dispatching framework, optimization model, and solution algorithm are verified by the analysis of 8 typical production water scenarios. This study not only provides Huanghua Port with a water resource dispatching optimization solution but also provides a decision-making reference for the green and intelligent transformation and upgrading of other large-scale coal bulk ports.

Exploring evolutionary features of directed weighted hazard network in the subway construction**Project supported by the Co-Funding of National Natural Science Foundation of China and Shenhua Group Corporation Ltd (Grant No. U1261212) and the Program of Major Achievements Transformation and Industrialization of Beijing Education Commission, China (Grant No. ZDZH20141141301).

A better understanding of previous accidents is an effective way to reduce the occurrence of similar accidents in the future. In this paper, a complex network approach is adopted to construct a directed weighted hazard network (DWHN) to analyze topological features and evolution of accidents in the subway construction. The nodes are hazards and accidents, the edges are multiple relationships of these nodes and the weight of edges are occurrence times of repetitive relationships. The results indicate that the DWHN possesses the property of small-world with small average path length and large clustering coefficient, indicating that hazards have better connectivity and will spread widely and quickly in the network. Moreover, the DWHN has the property of scale-free network for the cumulative degree distribution follows a power-law distribution. It makes DWHN more vulnerable to target attacks. Controlling key nodes with higher degree, strength and betweenness centrality will destroy the connectivity of DWHN and mitigate the spreading of accidents in the network. This study is helpful for discovering inner relationships and evolutionary features of hazards and accidents in the subway construction.

Experimental study on the macerals enrichment of Shenhua low-rank coal by Falcon centrifugal concentrator

ABSTRACTThis paper studied the macerals enrichment of the low-rank coal which produced by Shigetai Coal Mine, Shenhua Group. The coal sample fed to the Falcon were the product of the rod mill after 10 minutes grinding. Three factors were carried out, rotational frequency, feed rate and water pressure. The orthogonal experiment was designed to investigate the interaction between the three factors and a model was established between the factors and response values. Taking the vitrinite recovery rate as the response value, there was an interaction between the rotational frequency and the water pressure, moreover, the effect of the rotational frequency on the vitrinite recovery rate was greater than the water pressure, while, the feed rate on the vitrinite recovery rate was not significant. Taking the vitrinite enrichment ratio as the evaluation index, the Quadratic model was recommended, there was an interaction between the rotational frequency and the feed rate, moreover, the rotational frequency had better response to the vitrinite enrichment ratio than the water pressure and the feed rate. In order to optimize the experimental conditions, and the vitrinite enrichment ratio was set to 1.2, the vitrinite recovery rate was the larger the better, the optimal separation conditions obtained were the rotational frequency 30Hz, the water pressure 0.03MPa, and the feed rate 15ml/s in the laboratory.

Enabling Industrial Internet of Things (IIoT) towards an emerging smart energy system

The increasing penetration of renewable energy on the transmission and distribution power network is driving the adoption of two-way power flow control, data and communications needed to meet the dependency of balancing generation and load. Thus, creating an environment where power and information flow seamlessly in real time to enable reliable and economically viable energy delivery, the advent of Internet of Energy (IoE) as well as the rising of Internet of Things (IoT) based smart systems.The evolution of IT to IoT has shown that an information network can be connected in an autonomous way via routers from operating system (OS) based computers and devices to build a highly intelligent eco-system. Conceptually, we are applying the same methodology to the IoE concept so that Energy Operating System (EOS) based assets and devices can be developed into a distributed energy network via energy gateway and self-organized into a smart energy eco-system. This paper introduces a laboratory based IIoT driven software and controls platform developed on the NICE Nano-grid as part of a NICE smart system Initiative for Shenhua group. The goal of this effort is to develop an open architecture based Industrial Smart Energy Consortium (ISEC) to attract industrial partners, academic universities, module supplies, equipment vendors and related stakeholder to explore and contribute into a test-bed centric open laboratory template and platform for next generation energy-oriented smart industry applications.In the meanwhile, ISEC will play an important role to drive interoperability standards for the mining industry so that the era of un-manned underground mining operation can become the reality as well as increasing safety regulation enforcement.

Professional Synergetic Management and ControlMode of Major Hazard Sources of Coal Mine Gas

Achieving advanced control of major hazard sources of gas is an important basis to ensure sound development of coal mining industry. With the gradual strengthening of the national demand for coal mine safety, the traditional mode of coal enterprises in cooperation with scientific research institutes has been difficult to adapt to it. In order to solve this problem, influence factors of professional synergetic management and control of major hazard sources of coal mine gas were analyzed. Then its evolutionary process was studied. On this basis, Professional synergetic management and control mode of major hazard of coal mine gas was proposed creatively. And the operating system which matched the pattern was established. The demand of both coal enterprises and research institutes were taken a full consideration in this mode. And new ways of deep collaboration of production and research of it was provided, which opened up new roads to speeding up transforming scientific and technological achievements. This mode has been successfully used and promoted in Shenhua group, which made significant economic and social benefits.

Development of a supercritical and an ultra-supercritical circulating fluidized bed boiler

The supercritical circulating fluidized bed (CFB) boiler, which combines the advantages of CFB combustion with low cost emission control and supercritical steam cycle with high efficiency of coal energy, is believed to be the future of CFB combustion technology. It is also of greatest importance for low rank coal utilization in China. Different from the supercritical pulverized coal boiler that has been developed more than 50 years, the supercritical CFB boiler is still a new one which requires further investigation.Without any precedentor engineering reference, Chinese researchers have conducted fundamental research, development, design of the supercritical CFB boilers independently. The design theory and key technology for supercritical CFB boiler were proposed. Key components and novel structures were invented. The first 600 MWe supercritical CFB boiler and its auxiliaries were successfully developed and demonstrated in Baima Power Plant, Shenhua Group as well as the simulator, control technology, installation technology, commissioning technology, system integration and operation technology. Compared with the 460 MWe supercritical CFB in Poland, developed in the same period and the only other supercritical one of commercial running in the word beside Baima, the 600 MWe one in Baima has a better performance. Besides, supercritical CFB boilers of 350 MWe have been developed and widely commercialized in China. In this paper, the updated progress of 660 MWe ultra-supercritical CFB boilers under development is introduced.

Application of China's CCUS Environmental Risk Assessment Technical Guidelines (Exposure Draft) to the Shenhua CCS Project

The environmental risk assessment is an important research content of carbon dioxide (CO2) capture, utilization and geological storage (CCUS). In this paper, we firstly addressed the exposure draft of China's Technical Guideline on Environmental Risk Assessment for Carbon Dioxide Capture, Utilization and Storage. Then, we applied this technical guideline to the Shenhua Group's CCS demonstration project located in the Ordos Basin, China. The feature-event-process analysis and risk matrix method were used to evaluate the consequences and the possibility of environmental risks of the project. Finally, through the example of verification, we investigated the applicability and potential problems of this technical guideline. Though the final release of this technical guideline on June 20, 2016 has some notable changes, the whole assessment method and operational procedures of this paper can be used all the time without changes.

Clean coal technologies in China based on methanol platform

Coal is the most abundant fossil energy, however, coal industry is threatened by its environmental problems caused by the traditional way of utilization. In recent years, China has developed a series of clean coal technologies to transform black-dirty coal into clean fuels and chemicals. Shenhua Group, the largest coal company in China is leading the commercialization of modern clean-coal technologies for value-added chemicals and clean transportation fuels, in which CO2 is captured in the process and ready for carbon capture, utilization and storage (CCUS). Industrial plants for coal based methanol production and conversion are flourishing in last decade. With the development of renewable H2, methanol production could be realized by CO2 hydrogenation to transform into “Methanol Economy”, the sustainable energy development system. This paper will focus on the overview of research and development of methanol-based coal conversion technologies in China, such as methanol synthesis, methanol to olefins (MTO), chemicals (formaldehyde, acetic acid, aromatics, ethanol, ethylene glycol, etc.), gasoline (MTG), dimethyl ether (DME), polyoxymethylene dimethyl ethers (DMMn), methyl tert-butyl ether (MTBE), direct combustion (DMFC), and as energy carrier. Commercial and successfully demonstrated units in China on both the synthesis of methanol and its utilization are discussed in detail.

Mechanism of hydrogen transfer and role of solvent during heating-up stage of direct coal liquefaction

In this paper, the liquefaction of a Bulianta coal, from China Shenhua Group, was carried out in a hydrogen donor solvent, tetralin, or a non-hydrogen donor solvent, 1-methylnaphthalene, with or without catalyst to clarify the mechanism of hydrogen transfer. And roles of solvent and a nano-size iron catalyst from Shenhua Group in the heating-up stage of DCL were also investigated by using mixed solvent of decalin, phenanthrene, pyrene or fluoranthene and tetralin. The results show that tetralin inhibits the reaction of coal macromolecule to oil and the transfer of H2. The major transfer approach of H2 may be directly from H2 to coal rather than via the hydrogen donor solvents in the presence of the nano-sized iron catalyst. In the heating-up stage of DCL, the major role of solvent is to provide activated hydrogen for coal. High dissolving capability of the liquefaction solvent that has high enough hydrogen donor capacity is beneficial for improving liquefaction performance. The dominant function of the catalyst is to promote the activation of H2, which can improve coal liquefaction performance in the heating-up stage of DCL.

Technology Development and Engineering Practice for Protection and Utilization of Water Resources in Coal Mining in Western China

Shanxi, Shaanxi, Inner Mongolia, Ningxia, and Gansu (hereafter generally referred as Western Area) are major coal-producing areas in China due to rich coal resources and good mining conditions. However, the Western Area has a serious water shortage. The surface evaporation is huge and a great amount of mine water generated in coal mining is evaporated and lost after discharging to surface. In order to protect and utilize the water resources during large-scale coal mining in the Western Area, Shenhua Group has put forward a technological idea to store mine water in underground mined areas and successfully researched and developed the coal mine underground reservoir technology by solving the technical difficulties of water source prediction, reservoir site selection, reservoir capacity design, dam construction, safety guarantee, water quality control and so on through 20 years of exploration. Now Shenhua Group has successfully established a batch of reservoir in the Shendong Mining Area, obtaining great economic and social benefits. The technology is also extended to other western mining areas, providing an effective path for harmonic mining of coal and water resources in western China.

Approach to increasing the quality of pressure-relieved gas drained from protected coal seam using surface borehole and its industrial application

During mining of lower protective coal seam, a surface borehole can efficiently extract not only the pressure-relieved gas from the protected layer, but also the gas from the mining layer gob. If the distance between the borehole and gob is too large, the quantity of gas drained from the protected layer decreases substantially. To solve this problem, a mathematical model for extracting pressure-relieved gas from a protected coal seam using a surface borehole was established, based on the radial gas flow theory and law of conservation of energy. The key factors influencing the quantity of gas and the drainage flow network using a surface borehole were presented. The results show that the quantity of pressure-relieved gas drained from the protected layer can be significantly increased by increasing the flow resistance of the borehole bottom. Application of this method in the Wulan Coal Mine of the Shenhua Group significantly increased the flow of pure gas and the gas concentration (by factors of 1.8 and 2.0, respectively), thus demonstrating the remarkable effects of this method.

EROI Analysis for Direct Coal Liquefaction without and with CCS: The Case of the Shenhua DCL Project in China

Currently, there are considerable discrepancies between China’s central government and some local governments in attitudes towards coal to liquids (CTL) technology. Energy return on investment (EROI) analysis of CTL could provide new insights that may help solve this dilemma. Unfortunately, there has been little research on this topic; this paper therefore analyses the EROI of China’s Shenhua Group Direct Coal Liquefaction (DCL) project, currently the only DCL commercial project in the world. The inclusion or omission of internal energy and by-products is controversial. The results show that the EROIstnd without by-product and with internal energy is 0.68–0.81; the EROIstnd (the standard EROI) without by-product and without internal energy is 3.70–5.53; the EROIstnd with by-product and with internal energy is 0.76–0.90; the EROIstnd with by-product and without internal energy is 4.13–6.14. Furthermore, it is necessary to consider carbon capture and storage (CCS) as a means to control the CO2 emissions. Considering the added energy inputs of CCS at the plant level, the EROIs decrease to 0.65–0.77, 2.87–3.97, 0.72–0.85, and 3.20–4.40, respectively. The extremely low, even negative, net energy, which may be due to high investments in infrastructure and low conversion efficiency, suggests CTL is not a good choice to replace conventional energy sources, and thus, Chinese government should be prudent when developing it.

Exploration and Practice in Systems Engineering Management of Large Coal-based Integrated Energy Projects of Shenhua

With an analysis of current development of China’s coal industry, this paper, in the perspectives of concept innovation, technological innovation and management innovation, introduces the exploration and engineering practice by Shenhua Group in coordination with coal and the environment, co-development of coal and the associated resources as well as clean and efficient utilization of coal. Based on systems engineering of Shenhua’s coal-based integrated energy projects, the paper also presents practice and experience in technological and management innovation.

Modelling CO2-brine-rock interactions in the Upper Paleozoic formations of Ordos Basin used for CO2 sequestration

Subsurface immobilization and conversion of CO2 into solid mineral phases in deep siliciclastic saline formations containing silicate minerals, commonly known as “mineral trapping”, is gaining research attention as a significant option to reduce CO2 emissions in the atmosphere. Although mineral trapping of CO2 is a long-term process, a combination of short-term results from both laboratory experiments and numerical simulations can lead to some general understanding of the required long-term CO2 sequestration mechanisms. This is a 100 year preliminary batch simulation study of four sandstone samples, under CO2 saturated water at 75 °C from the Upper Permian formations in the Ordos Basin, using the TOUGHREACT/ECO2N module to simulate the CO2-brine-rock interaction processes in deep siliciclastic multilayered saline aquifers. The samples approximately correspond to the four target saline formations selected by the Shenhua Group for a CO2 sequestration field demonstration project in the Ordos Basin, PR China. Preliminary simulation results show that the initial salinity of formation brine plays a significant role in determining the amount of CO2 that will be sequestered by solubility or mineral trapping in a deep saline aquifer. Minimal differences between experimental results and numerical calculation occur in low salinity waters, and significantly larger differences in high salinity waters, which is still under the maximum acceptable difference between experimental and computed data (10 %). The upper Liujiagou formation, with the highest level of salinity (ca. 88.7 g/L TDS) and lowest level of CO2 solubility, offers the highest mineral trapping capacity, with a maximum carbonate mineral storage of ca. 0.7 kg/m3 of bulk rock over a 100 year period. Regardless of the initial acidity or alkalinity of the aquifer brine, injection of CO2 will inflict a sudden drop in pH of the brine to acidity levels in a range of 3.0–4.6. The subsequent amount of dissolved and precipitated minerals, arising from the CO2-brine-rock interaction, is site specific and mainly dependent on initial aquifer mineralogy and brine composition.

Supercritical CO2 dissolution and mass transfer in low-permeability sandstone: Effect of concentration difference in water-flood experiments

Core-flood experiments of supercritical CO2 (scCO2) and water were conducted under pressures higher than 10.00MPa and a temperature of 40°C to investigate scCO2 dissolution and mass transfer in water and their effects on displacement and imbibition. In these experiments, two representative sandstone cores of low permeability obtained from Shenhua Group CCS site in the Erdos Basin in China were used. On each core sample, five water-flood experiments were performed on the scCO2-saturated core by injecting water of a wide range of dissolved CO2 concentration (from CO2-free to CO2-saturated) for ∼37h, with a focus on the effect of differential concentration (ΔC) (i.e., the difference between the concentration of solubility and that of injected water) on dissolution and mass transfer, as well as displacement. An additional experiment was conducted on the first sample by water flood using CO2-free injected water into the scCO2-flooded core initially saturated by water free of dissolved CO2. In each experiment, the mass flow rate of scCO2 as a free phase and the net mass rate of dissolved CO2 were measured and calculated for core effluent. For the first sample, the residual CO2 saturation ranges from 0.52 in the case of ΔC=0–0.67 in the case of ΔC=solubility, after two displacement periods of stable and unstable scCO2 mass rate. The difference in residual saturation indicates that scCO2 dissolution during displacement may enhance snap-off, thus trapping more scCO2. At the end of the four unsaturated experiments, nearly all the residual CO2 mass is dissolved into the injected water through local CO2 dissolution and mass transfer between the dissolved CO2 and displacing water. In each experiment, the measured mass rate of dissolved CO2 decreases significantly over the time from that of ΔC in period III to more than two orders of magnitude smaller in period V. The dependence on ΔC of mass flow rate and net effluent concentration in periods III and V indicates that local CO2 dissolution in large pores in period III and in small and fine pores over all the time is at equilibrium as scCO2 residence time is sufficiently long. In periods IV and V, the overall mass transfer is non-equilibrium, leading to a lengthy depletion process, in comparison to an equilibrium case. The contribution of equilibrium dissolution in small and fine pores is also demonstrated by one order of magnitude reduction in effluent concentration in the additional experiment as these pores are not accessible by scCO2. The similar behavior of dissolution and mass transfer and their effect on displacement in both samples are obtained. A logistic model developed can reasonably represent the S-shaped function between mass transfer rate and core mass ratio as a function of scaled ΔC.

Modeling and measurement of CO2 solubility in salty aqueous solutions and application in the Erdos Basin

Geological carbon storage (GCS) is recognized as an effective method for mitigating the greenhouse effect. Deep saline aquifers hold the highest potential capacity for CO2 storage. CO2 solubility in salty aqueous solutions under geological sequestration conditions plays a key role in GCS. However, most CO2 solubility studies focus mainly on single-salt solutions (NaCl and CaCl2), and extrapolation of these studies to aqueous solutions with mixed ions is unavailable. To fill the research gap, based on the collection of CO2 solubility data, a semi-empirical thermodynamic model is proposed in this paper to calculate CO2 solubility in aqueous solutions containing K+, Na+, Ca2+ and Mg2+ in the temperature and pressure ranges from 313K to 378K and from 50bar to 220bar. To describe the CO2–liquid phase equilibrium, the Peng–Robinson equation of state (PR EoS) and the Setschenov equation are applied. The former has been modified to improve its performance in the studied T–P range, and the latter shows excellent accuracy with only three optimized parameters. Before modeling was done, experimental studies were conducted. Brine sampling from five reservoirs potentially chosen for CO2 sequestration in the Erdos Basin was carried out using a monitoring well in the support of the Shenhua Group carbon capture and storage (CCS) site project. The chemical composition of the samples was determined, and experiments measuring CO2 solubility were carried out in synthetic brine with 64 valid data points reported. An analytical method with a simplified sampling technique was chosen. In the range studied, the average absolute deviation of CO2 solubility between the model and experimental results was 2.01%, and the maximum absolute deviation in this study was less than 4.79%. The proposed model and experimental data therefore possess broad adaptability to GCS with satisfactory accuracy.