Coal Transportation Research Articles

Tourism activities significantly contributed toatmospheric pollutants in a remote town of Tianshan revealed by the continuous observation of two years

The large reduction in tourism activities in 2020 provided a unique opportunity to investigate their contribution on atmospheric pollutants in Bayanbulak, a remote town in Tianshan, China. In this scenic and sensitive region, we measured total suspended particulates (TSP) along with concentrations of polycyclic aromatic hydrocarbons (PAHs), organic carbon (OC), elemental carbon (EC) and water-soluble inorganic ions (WSIIs) during the lockdown in 2020 and compared these to levels in the pre-pandemic period of 2019. The study revealed significant reductions in PAHs, OC, EC, and some WSIIs concentrations during the tourist season (May–October) of 2020 compared with 2019, whereas variations between non-tourist seasons were less pronounced. Furthermore, by comparing pollutant characteristics in tourist seasons of these two years, we found that 5- and 6-ring groups were main PAH constituents in 2019, while 5- and 3-ring groups contributed more to total PAHs in 2020. OC/EC ratio increased from 2019 to 2020, indicating an increase of biomass burning contribution after the lockdown. Using positive matrix factorization, we determined that emissions from tourism-related transportation and combustion of natural gas and coal (mainly for cooking) contributed 21.9% and 46.6%, respectively, to certain atmospheric pollutants in 2019, whereas they decreased significantly to 3% and 19.4% in 2020 with dust and biomass contributions increased substantially. The levels of PAHs, OC, and EC from tourism-related sources were as high as 9.31 ng m−3, 1.28 μg m−3 and 0.11 μg m−3 and decreased by 54.37%, 25.16%, and 9.54%, respectively, compared to 2019. Hence, the impact of tourism must be considered during the assessment of local air pollutant emissions, particularly in remote areas.

THE INFLUENCE OF SERVICE QUALITY, PRICE PERCEPTION, AND PRODUCT QUALITY FROM PT KERETA API INDONESIA (PERSERO) ON CUSTOMER SATISFACTION AT PT BUKIT ASAM, TBK

This study examines the factors influencing customer satisfaction of PT Bukit Asam, Tbk regarding the services and products provided by PT Kereta Api Indonesia (Persero) for coal transportation. Customer satisfaction is analyzed based on three key factors: service quality, price perception, and product quality, specifically in transporting coal from the Tanjung Enim Mining Unit to Tarahan Port and Kertapati Pier, which accounted for 32,423,156 tons transported in 2023. The research findings indicate that all three factors—service quality, price perception, and product quality—have a positive and significant effect on customer satisfaction. The contribution of this research is twofold: it provides insights into the direct impact of these factors on corporate customer satisfaction and offers practical recommendations for PT Kereta Api Indonesia (Persero) to enhance its service performance, thereby improving its competitiveness in Indonesia's transportation and logistics sector. Future research could focus on additional factors, such as technological innovation and environmental sustainability, and investigate their influence on customer satisfaction across different industries or regions, offering broader insights into service quality improvement in the logistics industry.

Green logistics optimization for coal supply in a power plant connecting maritime port

This study addresses the coal transportation and flow distribution challenges within a “port-before-plant” type thermal power plant, with a strong emphasis on green logistics principles. Despite significant advancements in clean energy, coal remains a dominant energy source in China, necessitating optimization in its usage and management to mitigate environmental impacts. This paper introduces an integrated optimization model grounded in green logistics and employs an Improved Particle Swarm Optimization (IPSO) algorithm to efficiently manage the coal supply chain from unloading at ports to loading into generators. The model incorporates new parameters and constraints that not only reflect the operational realities of coal logistics but also emphasize minimizing carbon emissions and energy consumption. Numerical experiments demonstrate the algorithm’s superior performance compared to traditional solvers like Gurobi, particularly in handling large-scale instances. Sensitivity analysis reveals the importance of prioritizing efficient and environmentally sustainable unloading and loading equipment, suggesting strategies for optimizing green coal transportation routes. Overall, this research provides valuable insights for policymakers and industry operators to enhance operational efficiency while ensuring environmental sustainability through the implementation of green logistics

Use of electron microscopy to determine presence of coal dust in a neighborhood bordering an open-air coal terminal in Curtis Bay, Baltimore, Maryland, USA

BackgroundDespite decreasing US consumption, over 90 million metric tons of coal were exported by the US in 2023, requiring significant infrastructure for transport, handling, and storage of coal at export terminals. Residents in Curtis Bay, Baltimore, Maryland, USA live at the fenceline of an open-air coal terminal and have, for decades, reported rapid accumulation of black dust at their homes. Community-level exposure to coal dust originating from coal handling and storage terminals has remained largely unexplored. ObjectivesTo investigate community-identified concerns and use a community-driven approach to determine the presence/absence of coal dust in Curtis Bay surfaces. MethodsPassive settled dust samples were collected from two residential areas, 345 m and 1235 m from the coal terminal, using conductive carbon tape. Scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDX) of standard reference coal material and a positive control material from the coal terminal in Curtis Bay were used to optimize the morphological and elemental classification criteria for coal dust. A manual SEM-EDX protocol was developed to identify coal particles in settled dust collected on conductive carbon tape in community settings. ResultsSEM-EDX analysis confirmed presence of coal dust sampled at both residential locations. Estimated coal dust particle loading at the proximal and distal site were 13.2 and 3.4 coal particles/mm2, respectively. The coal dust particles identified met specific criteria, including size (>5 μm), morphology, and elemental composition (≥75 % carbon, ≤20 % oxygen). DiscussionThese findings are consistent with longstanding community concerns and lived experiences regarding the presence of coal dust in Curtis Bay, which neighbors a major open-air coal terminal. This approach has potential for other communities neighboring coal terminals to assess similar concerns with residential coal dust exposure.

Analysis of dominant flow in tectonic coal during coalbed methane transport

Diffusion and seepage are the main flow forms of coal seam gas transport, and are one of the key factors in the selection of gas extraction improvement methods. Changes in the physical structure of tectonic coal make gas transport more complex during coalbed methane extraction. In this paper, we develop a multi-field coupled model of methane transport in coal seams, taking into account the effects of tectonics, and theoretically analyze the dominant flow patterns for methane extraction. Then, the evolution of gas dominated flow is analyzed for different initial pressures, initial permeabilities, and initial diffusion coefficients of tectonic and intact coal seams. The results show that the amount of daily methane seepage in tectonic coal increases with the initial pressure of the coal reservoir, but decreases with the initial diffusion coefficient of the coal reservoir. Methane seepage in tectonic coal has a longer control time than in intact coal at different initial pressures, initial permeabilities, and initial diffusion coefficients of the coal reservoir. For different coal reservoir initial pressures, coal reservoir initial permeabilities, and coal reservoir initial diffusion coefficients, the maximum seepage control time for tectonic coal is 20, 17, and 15 times longer than for intact coal, respectively. Finally, the discrepancies of methane dominant flow in tectonic coal and intact coal during methane extraction were analyzed by using the double bottleneck flow model, and methods for methane enhanced extraction in tectonic coal and intact coal were discussed. The results presented in this paper may provide a theoretical reference for the extraction of differentiated gas in coal seams.

Simulation of Ship Berthing Operation at Luojing Container Terminal Under Extreme Sea Conditions

The Luojing Port Area of the Port of Shanghai, specifically the coal terminal and ore terminal, used to be the main port area for coal and ore bulk cargo transportation services in the Port of Shanghai.To enhance the container handling capacity at Shanghai port, this study conducted a series of simulation tests at Luojing Container Terminal. The tests were designed according to the terminal's specifications, taking into account the limit berthing wind direction and wind speed (levels 6 and 7). This study selected an appropriate representative ship type for the comprehensive simulation tests, and it thoroughly tested the berthing limits under various extreme conditions using an advanced navigation simulator. The experiment obtained the motion parameters and trajectory of the simulated ship. Based on these results, this study analyzed and evaluated the safety of the rotary waters and berthing operations, ensuring they met the safety assessment requirements for wharf engineering. The study examined the berthing time window, berthing mode, boundary conditions, and safety guarantee measures under extreme sea conditions at Luojing Container Terminal. Finally, By analyzing the berthing simulation trajectory diagrams, tugboat usage, and vessel maneuvering data under the eight extreme berthing conditions, this study formulated a safe berthing plan for ships.

SNW YOLOv8: improving the YOLOv8 network for real-time monitoring of lump coal

Abstract Due to the large size of the coal and the high mining output, lump coal is one of the hidden risks of mining conveyor damage. Typically, lump coal can cause jamming and even damage to the conveyor belt during the coal mining and transportation process. This study proposes a novel real-time detection method for lump coal on a conveyor belt. The Space-to-Depth Conv (SPD-Conv) module is introduced into the feature extraction network to extract the features of the mine's low-resolution lump coal. To enhance the feature extraction capability of the model, the Normalization-based Attention Module (NAM) is combined to adjust weight sparsity. After loss function optimization using the Wise-IoU v3 (WIoU v3) module, the SPD-Conv-NAM-WIoU v3 YOLOv8 (SNW YOLO v8) model is proposed. The experimental results show that the SNW YOLOv8 model outperforms the widely used model (YOLOv8) in terms of precision and recall by 15.82% and 11.71%, respectively. Significantly, the real-time detection speed of the SNW YOLOv8 model is increased to 192.93 f/s. Compared to normal models, the SNW YOLO v8 model overcomes the disadvantages of normal models, such as being overweight, and the parameters of SNW YOLO v8 are reduced to only 6.04 million with a small model volume of 12.3 MB. Meanwhile, the floating point of SNW YOLOv8 is significantly reduced. Consequently, it demonstrates excellent lump coal detection performance, which may open up a new window for coal mining optimization.

Double marginalization in the pricing of complements: The case of US freight railroads

AbstractMonopolists selling complementary products charge a higher price in a static equilibrium than a single (multiproduct) monopolist would, reducing both the industry profits and consumer surplus. Firms could instead reach a Pareto improvement by lowering prices to the single‐monopolist level. We analyze pricing data of railroad coal shipping in the United States. We compare a coal producer that needs to ship from A to C, with the route passing through B, in two cases: (1) the same railroad owning AB and BC and (2) different railroads owning AB and BC. We do not find that the price in case (2) is higher than the price in case (1), suggesting that the complementary monopolist pricing inefficiency is absent in this market. Our findings are robust to propensity score blocking, causal machine learning algorithms, and difference‐in‐differences analysis. Our results have implications for vertical mergers, tragedy of the anticommons, mergers of firms selling complements, elimination of double marginalization, and royalty stacking and patent thickets.

Physical Simulation Experiment for Visualizing Pulverized Coal Transport in Propped Fractures

The issue of pulverized coal in coalbed methane wells during the discharge and mining process spans all stages, and it is a key factor constraining the continuous and stable discharge and production capacity of coalbed methane. Among these stages, the single-phase water flow stage features a high incidence of pulverized coal. Consequently, this paper presents a physical simulation experiment within the propped fractures during the single-phase water flow stage. The results of this study reveal the following: (1) Within the propped fracture channel, when pulverized coal is deposited along the flow line without causing blockage, the front end of the deposition exhibits a strip-like dispersion, evolving into “block deposition”, “flame-like accumulation”, “linear accumulation”, and “dispersed point-like accumulation”. (2) Agglomerated fracturing fluid can effectively mitigate the permeability damage caused by pulverized coal to the propped fractures. Both the driving speed and particle size of pulverized coal significantly influence pulverized coal transportation. The injury rate of propped fracture conductivity increases with increasing driving speeds, while the output of pulverized coal first increases and then decreases with increasing driving speed. Moreover, larger pulverized coal particle sizes result in notably greater damage to propped fracture conductivity than smaller particle sizes. Correspondingly, larger particles exhibit significantly lower output of pulverized coal compared to smaller particles, and transportation and output time are prolonged for larger particles. These findings underscore the importance of particle size and driving speed in the transportation dynamics of pulverized coal. The research results provide a theoretical basis for developing strategies for the prevention and control of pulverized coal during the single-phase water flow stage, thereby offering substantial scientific and practical value for the economic and efficient development of coalbed methane.

Study on dynamic characteristics of anionic surfactants containing ethoxy groups wetting bituminous coal

Coal dust restricts coal mine safety and green production. Wet dust removal is widely used in coal mining, processing and transportation. High-efficiency dust suppressants help control coal dust and improve the working environment. The wetting behaviors of dust suppression droplets on coal affect the dust reduction efficiency. In order to select high-quality and efficient water-based materials, four ethoxy-containing surfactants with similar structures, fatty alcohol ether sulfate (AES), lauryl alcohol sulfosuccinate disodium (MES), fatty acid methyl ester ethoxylates (FMEE) and fatty acid methyl esters ethoxylate sodium sulfonate (FMES), are selected to prepare solutions with different concentrations. Through the droplet impact wetting experimental system, the dimensionless spreading coefficient of droplets is compared. The results show that the spreading behavior of the four surfactant-containing droplets is better than that of distilled water droplets, and the maximum dimensionless spreading coefficient follows the rule of AES > MES > FMES > FMEE >distilled water. The maximum dimensionless spreading coefficient of the droplet first increases sharply with the increase of the concentration, and then increases slowly when the concentration reaches the critical micelle concentration (CMC). The adsorption configuration of water-surfactant-coal system is simulated by molecular dynamics (MD) simulation. The relative concentration distribution of each component and the mean square displacement (MSD) of water molecules are analyzed. The interaction energy of the system is calculated. The simulation results verified the effectiveness of the impact wetting experiment results.

Recent Patents on Closed Coal Storage Systems and Research of Similar Experimental

Background:: Coal storage and conveying are key aspects of the coal industry, including coal stacking management systems and conveying systems. The traditional method of coal storage will easily lead to coal’s spontaneous combustion, which decreases the safety and reliability of storage. Meanwhile, problems are waiting to be solved with current conveying technologies, such as low levels of conveying efficiency. Objective:: To enhance the efficiency of coal conveying while improving safety and reducing environmental pollution, and promote the application of closed coal storage systems and pneumatic conveying technology. Method:: The patents and research proposed by many scholars analyzed the problems in coal transportation. Adopting pneumatic conveying technology and utilizing a similar experimental bench, by controlling the angle of the suction feeder and the height from the bottom, getting the optimal suction angle and position via experiment, which improves the efficiency of coal pneumatic feeding and discharging. Results:: A pneumatic feeding and discharging system and method are proposed for a coal storage silo with a high degree of integration and safety. Through similar experiments, it is concluded that the conveying efficiency is highest when the suction feeder is 30 mm high from the bottom, and the angle of the suction feeder is 45°. This provides theoretical support for the specific application of the device. Conclusion:: By analyzing patents and researching similar experiments, the proposed closed storage system for coal can improve coal conveying efficiency, reduce environmental pollution caused by coal particles during conveying, and decrease the possibility of spontaneous combustion and explosion of coal dust. The system is highly automated, easy to operate, and widely applicable.

TRAFFIC CAPACITY ANALYSIS OF EXISTING CONDITIONS WITH THE EFFECT OF ADDITIONAL COAL TRANSPORTATION TARGETS ON THE TANJUNG ENIM - TARAHAN RAILWAY LINE

The production volume target from 24.8 million tons in 2020 to 29.5 million tons in 2021 underlies the optimization of transportation availability in distributing coal mining products carried out by PT Bukit Asam Persero in achieving the growing target until 2023. In 2021, the Company will increase investment in developing business diversification, downstream coal. The railway network in Sumatra has a strategic role in serving the distribution of coal transportation. The railway line, which is directly connected to the location of the mining plant to port access and the availability of locomotive facilities and wagons that are very adequate, is an attractive option for mining companies and freight forwarders to establish coal transportation cooperation by rail. To meet the Babaranjang train tonnage target of 52 tons / year in accordance with the target of PT Bukit Asam (Persero), the Loop rail line design at TLS T4 PT Bukit Asam Muara Enim used the most effective classification. From the calculation results, 55 train trips are required per day to transport the production target of 57 tons / year in 2023. It is necessary to pay attention to the adequacy of the rail track from the TLS loop to Tanjung Enim Baru here it is necessary to conduct a study regarding the traffic from TLS to Tanjung Enim Baru because the number of trains set per day is 55 sets.

Operation Parameters Optimization Method of Coal Flow Transportation Equipment Based on Convolutional Neural Network

Operation Parameters Optimization Method of Coal Flow Transportation Equipment Based on Convolutional Neural Network

Evaluation of Coal Transport Route in Jambi City (Talang Duku Port-East Ring Road II)

In its implementation, the role of coal transportation infrastructure is important in supporting the mining industry in Jambi City. However, it also causes various complex problems; one of them is traffic congestion on arterial roads in Jambi City. In May 2023, the Jambi Regional Police of the Republic of Indonesia issued a notification letter to stop the mobilization of coal transportation in Jambi Province. The policy caused several coal companies to switch their transportation method to shipping in order to continue operating, while several other companies stopped operating until an indeterminate time. Therefore, this study aims to compare traffic performance before and after the implementation of the policy on Jambi City arterial roads, especially on Talang Duku Port Road and East Ring Road II. The method used was a comparative analysis of the degree of saturation before and after the enactment of regulations on the prohibition of coal truck operations. The results of this study show the importance of traffic management as one of the solutions to reduce traffic congestion. Nevertheless, other alternatives are still needed to support the smooth operation of coal transportation activities.

Preparation and Rheological Properties of the PVA/CMC/Gel Composite for Mining.

A composite gel material with an interpenetrating network structure was formed using the chemical cross-linking method. The viscosity, yield stress, and thixotropy of a poly(vinyl alcohol)/carboxymethyl cellulose/gelatin (PVA/CMC/Gel) composite gel slurry with different ratios were tested using a viscometer, and the interaction between the surface of the gelling agent and the cross-linking agent was analyzed by calculating the frontline orbital energy of a single polymer material molecule. The seepage diffusion characteristics of the composite gel in a goaf were then studied through a numerical simulation. The results indicate that the PVA/CMC/Gel composite gel exhibits shear thinning behavior following the power law model and behaves as a pseudoplastic fluid. The optimal ratio for the composite gel at 30 °C is determined as follows: 30 wt % for the gelling agent (PVA/(Gel + CMC) = 20:10), 4 wt % for the cross-linking agent, 3.09 wt % for the carbide slag, 7.5 wt % for the alcohol amine solution, and 0.5% sodium dodecyl sulfonate + 0.1% alkyl glycoside for the foaming agent. Gel exhibits the lowest energy band gap (0.096 eV), indicating strong reaction activity and strong reaction with the cross-linking agent (sodium tetraborate). PVA has the largest energy band gap (0.238 eV), strong molecular stability, and weak reaction with the cross-linking agent (sodium tetraborate). When the dip angle of the goaf is 4° and the injection time is 40 min, the composite gel tends to diffuse more easily along the dip. The investigation into the rheological properties of the PVA/CMC/Gel composite gel holds significant importance in the design of coal mine pipeline transportation and understanding diffusion flow in goaf.

Full-scale study on the coupling settling behavior of droplets and PM10 particles based on the CLSVOF method and wetting experiments

Coal mines produce large quantities of dust during production and transportation of coal, especially respirable particulate matter of diameter < 10 µm (PM10). This not only jeopardizes the health of workers but also pollutes the environment. Currently, spraying is the most commonly used dust reduction technology. Traditional spraying techniques use pure water; however, the wetting and condensing of dust by pure water droplets is poor, resulting in low dust reduction efficiency. To address this issue, we used orthogonal tests to determine the optimal ratio of composite dust-reducing agents. Using the coupled level set and volume of fluid (CLSVOF) method, we investigated the dynamic wetting process of PM10 when using solutions of dust-reducing agents. We found that a particle size ratio of ≥ 2 and an initial velocity of droplets of 20–40 m/s resulted in optimal wetting and encapsulation of dust particles by droplets. We then conducted macroscopic experiments and found that the settling efficiency of PM10 reached 88.98 % when using a 1.5-mm caliber fine atomizing nozzle and a spray pressure of 6 MPa. Our findings reveal the dynamic wetting law of droplets and dust during the process of spray dust reduction, which could lead to improved efficiency of dust-reducing agents and better management of respirable dust. These findings will help to improve clean production in coal mines and the occupational health of coal miners.

Research on Solidification Layer Detection in Coal Transportation Process Based on Improved YOLOv8 Algorithm

Railway transportation is one of the main modes of long-distance coal transportation, and it inevitably causes environmental pollution during the transportation process. In order to improve the environment along the railway and increase the utilization rate of coal resources, this paper proposes a detection algorithm for the scattered coal solidification layer during transportation based on the YOLOv8 model and designs an intelligent recognition model suitable for coal solidification layer detection devices by combining fluorescence detection methods. Through experimental analysis, we found that the model meets the requirements of practical detection and can play a crucial role in environmental protection, with high practical application value.

Joint Optimization of Inventory and Schedule for Coal Heavy Rail Considering Production–Transportation–Sales Collaboration: A Spatio-Temporal-Mode Network Approach

China’s coal industry has long faced challenges due to imbalance between supply and demand divisions and the discrepancies between supply and demand prices. Research on optimizing coal transfer amid fluctuating coal prices is crucial for enhancing coal resource allocation, ensuring a balanced and stable supply of coal resources, and promoting the sustainable development of the coal industry. This paper focuses on optimizing coal transfer schemes within a comprehensive transportation system, considering fixed transportation routes and opening times of railroad transportation and waterway transportation, with road transportation serving as a supplementary network. A three-dimensional spatio-temporal network model is established to represent the spatial and temporal paths and transportation modes of coal logistics. The study uses the coal transportation network from Inner Mongolia and Shaanxi to East China as a case study, analyzing factors such as coal price fluctuation, transportation rates, and the ratio of self-produced to purchased coal at the production end via sensitivity analysis. The findings indicate that the proposed model can effectively guide transportation practices under the integrated production, transportation, and sales framework in the energy industry. Additionally, it shows that enterprises can achieve higher profits and maintain revenue and supply stability despite coal price fluctuations, aligning with the coal industry’s transformation and development in the current context.

Power Analysis of 3 Phase Induction Motor Drive Conveyor 06 at PT. Mitrabara Adiperdana

Conveyor belt is a material handling tool that is widely used in minning industry. The tool consists of belts or tires made of various types of materials that are resistant to the transportation of solid objects or coal. In order to drive the conveyor, a 3-phase induction motor is needed. PT. Mitrabara Adiperdana used induction motors on each conveyor including conveyor 06. With consumer demand, motors continue to operate to drive conveyors in transporting coal on stockpiles filling barges. The number of berges filled makes the motor continue to operate to move the conveyor for up to one full day. Therefor, it is necessary to analyze the power of consumption and performance level of the motor on conveyor 06, because if there is demage to the motor, the production process on conveyor will be hampered. From the primary data obtained in the field by making direct measurements and obtained the calculation results, the power value is 35.058 Kw when the conveyor is not loaded and 81.80 kw when the conveyor is loaded. With the result of power used when loaded, the calculation of efficiency is 69,45%. Whith this value, the conveyor motor 06 operates less effectively. It is stated be effective when the efficiency value is between 80% and 100% of the effeciency value on motor rating rate.

Comparative analysis of permeability rebound and recovery of tectonic and intact coal: Implications for coalbed methane recovery in tectonic coal reservoirs

The permeability rebound and recovery of coal reservoirs is one of the key factors affecting the efficient recovery of coalbed methane (CBM). Most studies focus on the permeability rebound and recovery of intact coal reservoirs. Conversely, the permeability rebound characteristics of tectonic coal have only been rarely investigated. In this paper, an improved fully coupled mathematical model for methane transport of tectonic coal and intact coal seam was established. Then, the phenomenon of permeability rebound and recovery was analyzed theoretically, and the permeability rebound time, rebound value and recovery time were proposed to compare the difference in permeability evolution. In addition, the permeability rebound characteristics of tectonic and intact coal were evaluated for different geological parameters of coal reservoirs. The results indicate that the rebound time and recovery time of both intact and tectonic coal increase with the increase of initial gas pressure. As the initial permeability increases, the permeability rebound time of intact and tectonic coal show a decreasing trend. The permeability rebound time of intact coal decreases with increasing initial diffusion coefficient, while that of tectonic coal shows the opposite trend. Furthermore, the change in permeability recovery time for tectonic coal is 6.59 times larger than for intact coal, indicating that the effect of permeability rebound phenomenon is more significant during gas extraction in tectonic coal reservoirs. Finally, a conceptual model was proposed to explain the differential mechanism of permeability rebound between tectonic and intact coal, and its implications for CBM recovery in tectonic coal reservoirs was discussed. Therefore, the results presented in this paper can provide a theoretical basis for the efficient development of CBM in tectonic coal reservoirs.