Steam Coal Research Articles

Cost Benefit Analysis for Coal Steam Power Plants in Energy Security Framework

Indonesia’s energy security can be assessed using a four-pronged management approach: affordability, accessibility, availability, and acceptability. This aspect is influenced by various internal and external strategic environments, such as energy supply and demand trends, investment in supporting infrastructure development, and the impact of related and cross-sectoral policies and regulations. This study based on descriptive quantitative method with a cost-benefit analysis tool of sufficient coal supplies to coal steam power plants to meet supply quality and low-cost fuel-based electricity. Besides that, this study also uses PEST (Politics, Economy, Social, Technology) analysis to look at it from the external environment. The study used secondary data using cost-effectiveness analysis tools. In addition, Focus Group Discussion was conducted to identify variable indicators that can be used to analyze alternatives and interventions. FGD’s are also conducted to assess the recognition of each variable index. The assessment uses the Likert scale. A limitation of this study is that it is a short-term effort, so the cost-benefit analysis is limited to identifying alternatives and interventions being analyzed. The results of this study are an analysis of the economic value of coal as a fuel for steam power plants as a booster of the economy in Indonesia because it can produce a lot of strong and stable electricity with inexpensive infrastructure investment. The limitation of this research is the efficiency of alternatives in analyzing the cost benefits of coal as a fuel for steam power plants.

The Coal Quality CICS that Increases the Wear Resistance of Heat Exchanger Tubes

The paper discusses the threat of decommissioning of the thermal power plant (TPP) heat exchanger tubes because of erosion and develops a computer-integrated control system (COAL QUALITY CICS THAT INCREASES THE WEAR RESISTANCE OF HEAT EXCHANGER TUBES) for the process of distribution of steam coal flows with different indicators of abrasive materials content, which is based on fuzzy logic. The problem of rapid decommissioning of TPP heat exchanger, particularly abrasive damage to furnace screen tubes, economizer, superheater, etc. This may indicate a discrepancy between the expected fuel ash content and the actual one, as well as a high content of abrasive impurities in steam coal. The work aims to develop a CICS of the wear resistance of the heat exchange surface of a steam boiler of a coal-fired power plant by measuring and fuzzy control of the content of abrasive impurities in steam coal. The problems of damage to the equipment of the TPP boiler are investigated and a system for controlling the wear resistance of the surface by automatic fuzzy control of the quality of coal is developed. In order to investigate the effectiveness of the proposed fuzzy controller, the results were investigated in a specific example, in particular, during coal preparation and combustion in the furnace of a thermal power plant. The model results confirm the feasibility of the fuzzy control method for the system with different coal quality parameters.

Studi Pendahuluan Potensi Carbon Capture Storage (CCS) Melalui Identifikasi Sumber Emisi CO2 beserta tinjauan geologi di Daerah Probolinggo, Jember, dan Bondowoso, Jawa Timur

Carbon dioxide (CO2) is a gas compound that causes the greenhouse effect. The majority of carbon dioxide gas production is dominated by large industrial industries such as Coal Steam Power Plants (PLTU), the cement industry and fossil fuel motorized vehicles (Hydrocarbons). Several technologies have been implemented and developed, in an effort to reduce the negative impact of CO2 accumulation on the earth's surface. One of them which is currently a topical topic is Carbon Capture Storage (CCS). CCS is a storage system used to receive and store carbon releases from industry and power plants into geological formations safely and permanently with a certain capacity for a long period of time. CCS is seen as a very efficient method because it can balance achieving net zero emissions while maintaining energy security. In this research, a preliminary study was carried out in the initial step of identifying potential sources of CO2 emissions along with a review of geology as a potential CO2 storage. In the Probolinggo, Jember and Bondowoso areas. From the identification results, it was concluded that the Paiton PLTU area in Probolinggo has the largest potential for CO2 production, around 1.98 million tons/year. The grological scope of the Paiton PLTU area meets one of the CO2 Storage criteria because the formation is included in the East Kendeng sedimentary zone. However, further studies need to be carried out to validate the potential for CO2 storage in further geological, petrophysical and fault analysis

Experimental Study on the Slime Flotation Process of Low-Rank Steam Coal by the Small Cone Angle Hydrocyclone Group

Experimental Study on the Slime Flotation Process of Low-Rank Steam Coal by the Small Cone Angle Hydrocyclone Group

Catalytic steam gasification of bituminous coal for syngas production with catalyst derived from calcium-rich construction demolition waste

A disposable Ca-containing catalyst was generated from a sort of calcium-rich construction demolition waste and utilized in the steam gasification of a bituminous coal in a fixed bed reactor. The effects of catalyst loading amount, gasifying temperature and catalyst loading method on steam gasification with respect to the production of syngas with high H2/CO mole ratio and CH4 content were investigated. The H2 and CO molar yields as well as carbon conversion increased noticeably with the increase of catalyst loading amount despite there was a saturation quantity. After loading 6.0 wt% catalyst into coal by kneading method, the carbon conversion and total gas molar yield increased from 52.56% and 136.06 mmol/g-C to 62.77% and 160.23 mmol/g-C, respectively. At low temperature, kneading method displayed superiority over mechanical mixing method in steam gasification performance of bituminous coal while they had approximately the same catalytic effect on coal steam gasification at high temperature. Characterization of SEM images and Raman spectroscopy of coal chars derived from catalytic pyrolysis confirmed that addition of catalyst changed the micro-crystal structure and formed more defects and amorphous structures. Overall, the catalyst showed satisfactory catalytic effect in steam gasification of bituminous coal and could be used as a suitable alternative of CaO for syngas production.

Revisiting the petrology of lower Pennsylvanian (Namurian and Langsettian) coals in southern West Virginia and southwestern Virginia, USA

Namurian and Langsettian coals representing a vertical span of about 650 m were sampled from cores in southern West Virginia and western Virginia. The coal rank ranges from medium through low volatile bituminous. Historically, a significant portion of the production from the region has been for smokeless steam coals and for metallurgical coal. Despite the presence of thrust faults and the potential for fault-induced movement of mineralizing fluids, a depth-of-burial/geothermal-gradient model, as proposed earlier, appears to be sufficient to describe the increase of rank with depth. The coals generally have >70% total vitrinite (mineral-free basis) and a telovitrinite/(telovitrinite + detrovitrinite) ratio exceeding 0.75. Fusinite dominates the inertinite group macerals. An unnamed Langsettian coal had a high liptinite content but, otherwise, in part owing to the difficulty of detecting liptinites in medium and low volatile bituminous coals, liptinite appears to be sparse. Among the coals in the study, not all of them have been extensively mined. The Pocahontas coals represent the most significant economic resource.

Research on 1mm desliming before separation and high-efficiency separation to improve quality for steam coal

ABSTRACT For the established steam coal preparation plant that uses dense-medium shallow groove separation process, reducing the separation lower limit is conducive to improving its economic benefits. Reducing the lower limit to be consistent with the mesh size of the demedium screen, which is 1 mm, so that more coal can be separated without affecting the normal operation of the entire system. A process of 1 mm desliming before separation and dense-medium shallow groove separation was proposed in this paper. The kinematic characteristics and desliming performance of rigid screen surface and elastic screen surface were compared and analyzed. The separation performance of each size coal in the dense-medium shallow groove separator was investigated and the ratio of upward medium flow and horizontal medium flow was optimized. The industrial experiment results showed that the screening efficiency and desliming efficiency of elastic screen surface were increased by 4.31% and 4.37% respectively compared with rigid screen surface. The separation performance of each particle size coal in the dense-medium shallow groove separator became worse with the decrease of particle size. When the ratio of upward medium flow and horizontal medium flow was 8:2, the separation performance of 200–1 mm size coal was the best, and its probable error was 0.04 g/cm3. The optimized process could significantly decrease the slime content in separation system and improve clean coal yield.

The impact of long-term contracts of the capacity market on the consumption of steam coal in the power system

The impact of long-term contracts of the capacity market on the consumption of steam coal in the power system

Steam Gasification in a Fluidized Bed with Various Methods of In-Core Coal Treatment

The aim of this work is to study coal steam gasification with various methods of coal in-core treatment in FB using a newly developed thermodynamic calculation method. A calculational study of subbituminous coal steam non-catalytic gasification was carried out using four different methods of coal in-core treatment in single-vessel multisectional fluidized-bed gasifiers. A semi-empirical model based on the entropy maximization thermodynamic method and “restricted equilibria” based on previously obtained experimental data has been developed. Based on thermodynamic calculations, the effect of the leading thermochemical processes and operating parameters of the fluidized bed (temperature, fluidization number, steam/coal ratio feed rate) was revealed. New information was obtained regarding the composition of char and syngas at the gasifier outlet, the syngas heating value, and the cold gas efficiency of the steam gasification of Borodinskiy subbituminous coal char. The results indicate the possibility of significantly accelerating and improving non-catalytic steam gasification in fluidized bed gasifiers through the appropriate organization of in-core coal treatment. Based on the results obtained, the following recommendation is made—when designing multi-section and multi-vessel steam-blown gasifiers, the ratio of residence times should be set in favor of increasing the coal residence time in the steam-blown carbonization zone. Structurally, this can be achieved by increasing the volume and/or area of the steam-blown carbonization section (vessel).

Analysis of Technical and Economics Overhead Transmission Line 150 kV Construction from Mine Mouth Coal Fired Power Plant to External Customer Substation

Mine Mouth Steam Coal Fired Power Plant (PLTU) has a capacity of 2x18MW while the power supplied to internal consumers is 3.6MW or around 10% of the total generating capacity (20% of one generating unit). To operate according to its specifications, the load is increased by operating the load bank. The small internal load and use of the loadbank cause the cost of generation to be high. Excess generating capacity can be sold to external consumers outside the mining area, so it is necessary to build one circuit overhead transmission line 150kV as long 48.38km. The construction of overhead transmission line 150kV from the PLTU to the external consumer substation can increase sales of electricity and can replace the loadbank function. This study aims to evaluate the technical feasibility and economic aspects of the construction overhead transmission line 150kV from the PLTU to an external consumer substation. The research method uses financial indicators IRR, NPV and ROI. Overall, the construction of one circuit overhead transmission line 150kV can increase sales of electricity and replace the function of load bank. The NPV value is IDR 1,604,887,094 with an IRR of 12.53%, and ROI of 9.03 years.

Experimental investigation on sulfur transformation during coal steam gasification with Ca-based absorbent

To investigate the effects of temperature, Ca-based absorbent (CaO) and atmosphere on the sulfur transformation characteristics in coal steam gasification, experiments were conducted in a fixed-bed reactor. As temperature increased from 600 °C to 750 °C, H2S-S (sulfur in H2S) was elevated by 21.86% and absorbent-S decreased by 7.66%. More gaseous sulfur was captured by organic groups to form organic sulfur in char at higher temperature. CaO promoted the sulfur conversion, and played the role of gaseous sulfur absorbent at the same time, and showed an ability of organic sulfur removal. CaO slowed down the H2S release by reacting with it to form CaS, resulting in that the peak concentration of H2S without CaO reached 1026.7 ppm, which decreased to 426.3 ppm with CaO. The increase in Ca/C promoted the sulfur conversion slightly and reduced the sulfate content in char. Compared with inert atmosphere, H2S-S in the steam atmosphere increased by 35.07%, while absorbent-S decreased by 23.42%. The solid–solid reaction mechanism is more suitable for the sulfate transformation in inert atmosphere, while the gas–solid reaction mechanism is more suitable in steam atmosphere. The sulfur conversion in inert atmosphere was lower, but sulfate had a higher decomposition rate.

The Wreck of the British Steamship Claverdale in the Russo-Japanese War 1904–1905

In the Russo-Japanese War 1904–5, neutral merchant vessels sailing to or from Russian Asia had to contend with war risks as well as customary maritime hazards and natural elements. The British steamship Claverdale, on its maiden voyage with a cargo of Welsh steam coal, left Hong Kong for Vladivostok in late November 1904. Posted overdue in mid-January 1905, it was declared missing in early May 1905 and found ashore some months later on the Tartary Coast far north of its intended destination. The contexts of and evidence for the ship’s loss are examined and causal hypotheses considered.

A novel decomposition integration model for power coal price forecasting

Accurate prediction of steam coal prices is important for stabilizing the coal trading market and formulating coal use strategies scientifically. In this paper, a new decomposition integration model (VADM) is proposed to predict coal prices by combining the variational modal decomposition (VMD), arithmetic optimization algorithm (AOA), deep temporal convolutional network (DeepTCN), and mean impact value algorithm (MIV). Firstly, the AOA optimization algorithm is used to improve the VMD, AOA-VMD was obtained. It is used to decompose the steam coal price series. Then, the decomposed subsequences are predicted for the prediction of steam coal prices by using DeepTCN. Finally, the MIV algorithm is applied to analyze the impact of different factors on the price of steam coal. It is found that: the steam coal price sub-series decomposed by AOA-VMD are smoother and more linear compared with the original series; the errors in forecasting steam coal prices are significantly reduced after considering newly proposed factors, interest rates, such as the overnight Shanghai interbank offered rate and the six-month treasury bond yield; the MAPE, MASE and SMAPE of the VADM model all show different degrees of decline compared with benchmark models. The forecasting effect of VADM model is better than the benchmark model in terms of stability and accuracy, and can be used for short-term forecasting of coal prices.

Distributional Predictability and Quantile Connectedness of New Energy, Steam Coal, and High-Tech in China

From a novel quantile perspective, this paper employs nonparametric quantile causality and quantile connectedness to investigate distributional predictability and spillover effects among new energy, steam coal, and high-tech under normal and tail conditions. We first identify the quantile causality: there is a unidirectional causality between the quantile orders 0.1 and 0.4 from technology high-tech to new energy, indicating that the stock price of technology companies has a predictive power of the stock prices of new energy companies when the latter is relatively low. Next, in terms of quantile connectedness, while the risk shocks to the system do not propagate strongly around the median, there are strong spillover effects in both tails. Moreover, high-tech and new energy contribute most of the system’s spillovers, and high-tech is the main net shock transmitter to all other variables. We further find that the strength of spillovers may depend on events such as China’s stock market rout of 2015 and the COVID-19 pandemic.

Estimation and forecasting of carbon dioxide emissions from coal-fired thermal power plants in Ukraine

Purpose. Development and verification of a method for calculating and forecasting CO2 emissions from coal combustion at thermal power plants based on proximate analysis data. Calculation of gross and specific CO2 emissions per unit of output energy and mass of coal consumed at Ukrainian thermal power plants (TPPs). Methodology. Methods of mathematical statistics were used for processing the data of ultimate and proximate analysis of 170samples of A, L, G, and LFG coal ranks with low heat value on operating state in the range of 17.2 to 31.0 MJ/kg and ash content on dry state (Ad) in the range of 3.8 to 38.0% to determine relationships between carbon emission factors (kc), calorific value, and ash content. Findings. The values of emission factors and gross CO2 emissions for mixtures of coals of grades A and L, G and LFG at Ukrainian TPPs in 20172021 were calculated. For 2021, the average value of for coals of grades G and LFG was 94,128 g/GJ, and for coals of grades A and L it was 104,987 g/GJ. Gross CO2 emissions at Ukrainian TPPs have been in the range of 3849million tons in recent years, and their annual reduction is due to a decrease in energy production and fuel consumption at TPPs, primarily of grades A and L. Originality. Empirical dependencies kc for steam coal of different ranks are determined in the form of The coefficients a, b, and c are determined for grades A, L, G, and LFG and their mixtures. The relationship between the carbon content in coal and the low heat value for coal is linear: where K is a coefficient depending on the coal grade. The values of K are determined for coal of grades A, L, G, and LFG. Practical value. Verification of the created method shows that the calculation error is less than 1.0%. This is in line with the requirements of the Monitoring Procedure and Directive 2003/87/EC. In 2021, the specific CO2 emission per unit of output energy at TPPs in Ukraine was 1,084 g/kWh for all ranks of steam coal. The values of specific CO2 emissions per unit mass of consumed coal were 1.94 t/t for coals of all grades, 1.91 t/t for grades G and LFG, and 2.21 t/t for grades A and L. The official annual reports of the Ministry of Energy of Ukraine contain information on the amount of produced electricity, consumed coal, and forecast balances of electricity production at TPPs, therefore, the values of specific emissions established by us are convenient to use for estimating and forecasting carbon dioxide emissions.

High Temperature Winkler gasification of Rhenish lignite in an optimized 500 kWth pilot plant

Gasification processes are an important part of a broad variety of value chains from low grade feedstocks to energy. The process considered in this work consists of a 0.5 MWth fluidized bed gasifier, a gas cleaning unit and a catalyst test rig. This paper presents experimental results from the stand-alone operation of the gasifier in order to investigate the behavior of the gasification of two feedstocks, a dried lignite steam coal and a commercially available low sulfur, low ash lignite. Furthermore, the results of the gasification of the gasifier start-up material hearth furnace coke are given. The reactor with a height of 11 m and an inner diameter of 400 mm was operated at up to 870 °C. Carbon dioxide, steam and oxygen can be introduced into the reactor through different nozzle levels.Four test campaigns were conducted and seven balance points with different feedstock and loads were investigated. The results show carbon conversions of almost 96 % and cold gas efficiencies up to 65 % with coal from fluidized bed drying showing the highest cold gas efficiencies and carbon conversions. Several trace gases were measured by Fourier-Transform Infrared Spectroscopy and a positive correlation between benzene and methane concentration is detected.The experience gained serves as a basis for the gasification step in the polygeneration process and for gasification of other feedstock, especially biogenic and anthropogenic residues.

Optimization of performance parameters and investigation of the heavy-medium separation column for the separation of 3-13mm steam coal

ABSTRACT To effectively separate 3–13 mm steam coal, new separation equipment which was a heavy-medium separation column was designed and tested in this study. Particles were measured to analyze the changes in the axial medium force of particles in the medium by employing the force measuring system. The influence of the medium flow rate (q), medium density (ρ), separation column height (h), and feed volume (g) on the separation effect was investigated by using the control variable method to establish the optimum separation condition. Under the optimum separation condition, the yield and the ash content of the clean coal were 74.05% and 16.18%, respectively. Based on the single factor study, the Box-Behnken response surface methodology (BBRSM) was used to investigate the influence of each interaction factor on the separation effect. The significance of each factor on the quantitative efficiency was in the order of ρ > q > h. Through the regression analysis, the mathematical model for the relationship between the quantitative efficiency and the separation parameters was established. The predicted quantitative efficiency and experimental quantitative efficiency were 87.88% and 89.32%, respectively. The difference between them was small, verifying the high accuracy and reliability of the prediction results of the regression equation model.

Low-emission and energetically efficient co-gasification of coal by incorporating plastic waste: A modeling study

The issues of global plastic waste generation and demand for hydrogen energy can be simultaneously resolved by gasification process. In this regard, feasibility and efficiency of steam and air co-gasification of coal by incorporating five different and prevalent types of plastic waste were investigated in this modeling study. All steam and air coal/plastic waste co-gasification types were multi-objective optimized utilizing a response surface methodology. The best co-gasification types were selected using VIekriterijumsko KOmpromisno Rangiranje (VIKOR) analysis. Overall, the results showed that incorporating plastic waste into coal gasification improved hydrogen concentration in the syngas and increased normalized carbon dioxide production due to the high carbon content of plastic waste and activation of water-gas and CO shift reactions. VIKOR analysis revealed that steam coal/low density polyethylene was the best optimized co-gasification type with hydrogen concentration of 62.8 mol %, normalized carbon dioxide production of 2.60 g/mol, based on the feedstock entering the system, and energy efficiency of 76.6%. Increasing gasifier temperature enhanced hydrogen concentration and decreased normalized carbon dioxide production. The energy efficiency was markedly improved by increasing the moisture content and decreasing the ratio of steam/feedstock. This study confirmed the hypothesis of efficient utilization of plastic waste in coal/plastic waste co-gasification.

Say's Second Visit to Britain: A Career Turning Point

Abstract Economist turned entrepreneur Say was uncertain about his future in 1814 when he was commissioned by the French government to document British industrial progress at a critical point of the industrial takeoff. This trip offered the opportunity to observe the economic life of a different country and to deepen his knowledge of the economic consequences of parliamentarism or the Corn Laws. He also developed a specific understanding of the changes occurring in Britain stressing economies of scale, the role of coal for steam, and the horrific situation of the working class. As key causes, he identified British naval domination of the seas and, more surprisingly, the general distortion induced by very heavy taxation. Through his travel, Say also imported new views about education that he disseminated in France before turning himself to the teaching of economics, starting, at forty-eight years of age, an academic career.

Studies on the Impacts of Excavation of Mineral Contact Sediments on the Behaviour of Steam Coals

Studies on the Impacts of Excavation of Mineral Contact Sediments on the Behaviour of Steam Coals