Tons Of Coal Research Articles

AVAILABILITY AND PHYSICAL PROPERTIES OF RESIDUES FROM MAJOR AGRICULTURAL CROPS FOR ENERGY CONVERSION THROUGH THERMOCHEMICAL PROCESSES

Plant residues from the major agricultural crops (w heat, rice, corn, soybean, sugarcane, coffee and co tton) are abundantly available renewable resources that can b e used to supply energy through thermochemical conversion processes. The available amounts of plant residues from these crops and their physical properties (moi sture content, particle size, bulk density and porosity) wer e determined. The annual residues from the wheat, r ice, corn, soybean, sugarcane, coffee and cotton were 763.42, 698.10, 1729.92, 416.62, 16.85, 4.01 and 107.13 million tons, respectively. The total amount of plant residues wa s estimated at 3736.05 million tons with total ener gy content of 66.92 EJ. These residues can replace 2283.52 millio n tons of coal, 1551.78 million tons of oil and 184 7.63 million m 3 of natural gas. The moisture contents were 7.79, 6 .58, 6.40, 7.30, 8.15, 7.86 and 7.45% for the wheat straw, rice straw, corn stalk, soybean stalk, sugar cane stalk, coffee husk and cotton stalk, respectiv ely. The corn stalk and sugarcane stalk had a convex particle siz e distribution, the soybean stalk and cotton stalk had a concave particle size distribution, the wheat straw and ric e straw had an increasing trend particle size distr ibution and the coffee husk had a decreasing trend particle size di stribution. The average particle sizes for the whea t straw, rice straw, corn stalk, soybean stalk, sugarcane stalk, coffee husk and cotton stalk were 0.42, 0.40, 0.49, 0.43, 0.55, 0.67 and 0.38 mm, respectively. The average bulk density was 160.75, 166.29, 127.32, 242.34, 110.86, 3 49.06 and 230.55 kg m -3 for the wheat straw, rice straw, corn stalk, soybe an stalk, sugarcane stalk, coffee husk and cotton stalk, respectively. The average porosity was 5 1.25, 83.20, 58.51, 68.03, 77.58, 64.85 and 74.55% for the wheat straw, rice straw, corn stalk, soybean stalk, sugarcane stalk, coffee husk and cotton stalk, res pectively. The results obtained from this study indicate that diff erent plant residues have different physical proper ties.

Standardized emissions inventory methodology for open-pit mining areas

There is still interest in a unified methodology to quantify the mass of particulate material emitted into the atmosphere by activities inherent to open-pit mining. For the case of total suspended particles (TSP), the current practice is to estimate such emissions by developing inventories based on the emission factors recommended by the USEPA for this purpose. However, there are disputes over the specific emission factors that must be used for each activity and the applicability of such factors to cases quite different to the ones under which they were obtained. There is also a need for particulate matter with an aerodynamic diameter less than 10μm (PM(10)) emission inventories and for metrics to evaluate the emission control programs implemented by open-pit mines. To address these needs, work was carried out to establish a standardized TSP and PM(10) emission inventory methodology for open-pit mining areas. The proposed methodology was applied to seven of the eight mining companies operating in the northern part of Colombia, home to the one of the world's largest open-pit coal mining operations (∼70Mt/year). The results obtained show that transport on unpaved roads is the mining activity that generates most of the emissions and that the total emissions may be reduced up to 72% by spraying water on the unpaved roads. Performance metrics were defined for the emission control programs implemented by mining companies. It was found that coal open-pit mines are emitting 0.726 and 0.180kg of TSP and PM(10), respectively, per ton of coal produced. It was also found that these mines are using on average 1.148m(2) of land per ton of coal produced per year.

Prediction of China's coal production-environmental pollution based on a hybrid genetic algorithm-system dynamics model

This paper proposes a hybrid model based on genetic algorithm (GA) and system dynamics (SD) for coal production–environmental pollution load in China. GA has been utilized in the optimization of the parameters of the SD model to reduce implementation subjectivity. The chain of “Economic development–coal demand–coal production–environmental pollution load” of China in 2030 was predicted, and scenarios were analyzed. Results show that: (1) GA performs well in optimizing the parameters of the SD model objectively and in simulating the historical data; (2) The demand for coal energy continuously increases, although the coal intensity has actually decreased because of China's persistent economic development. Furthermore, instead of reaching a turning point by 2030, the environmental pollution load continuously increases each year even under the scenario where coal intensity decreased by 20% and investment in pollution abatement increased by 20%; (3) For abating the amount of “three types of wastes”, reducing the coal intensity is more effective than reducing the polluted production per tonne of coal and increasing investment in pollution control.

Potentiality and prospects of underground coal mining in the Sjenica coal basin

The current level of exploration the Sjenica Basin with undeniably proven large reserves of quality coal, confirms that this is the most prospective coal deposit in the Republic Srpska for underground mining. Total explored geological coal reserves until now of approximately 20% of explored area are around 194 million tons of coal. Based on the analysis of mining-geological conditions of mining the coal reserves and balances, the fact of current mining in this area, and all comparative advantages, it can be concluded that there are real technical possibilities for construction the mine with production capacity of a very wide range. Production of energy by coal combustion in the immediate vicinity of the mine requires the construction of the facility of Thermal Power Plant of 250 MW. Comprehensive analysis the current state of the pit of the Mine 'Stavalj' shows that by implementing the optimization program, based on mining-geological conditions of exploitation and state of coal reserves in the Basin, it can be concluded that there are real opportunities to construct several underground production systems - pits. The existing mine pit with production of 130,000 tons per year - The pit 'Western Variant' with production of 700,000 tons per year - The pit 'Eastern Variant' with production of 200,000 tons per year With the existing pit, in the second stage of development of the Basin, it can be possible to produce annually about 1 million tons of coal from the underground mining. It enables the construction of the facility of Thermal Power Plant of 250 MW at the location exit from the Stavalj gorge towards the Mravin field.

Vertical transportation system of solid material for backfilling coal mining technology

For transportation of solid backfill material such as waste and fly ash from the surface to the bottom of the shaft in a fully mechanized backfilling coal backfilling coal mining technology, we developed a new vertical transportation system to transport this type of solid backfill material. Given the demands imposed on safely in feeding this material, we also investigated the structure and basic parameter of this system. For a mine in the Xingtai mining area the results show that: (1) a vertical transportation system should include three main parts, i.e., a feeding borehole, a maintenance chamber and a storage silo; (2) we determined that 486mm is a suitable diameter for bore holes, the diameter of the storage silo is 6m and its height 30m in this vertical transportation system; (3) a conical buffer was developed to absorb the impact during the feeding process. To ensure normal implementation of fully mechanized backfilling coal mining technology and the safety of underground personnel, we propose a series of security technologies for anti-blockage, storage silo cleaning, high pressure air release and aspiration. This vertical transporting system has been applied in one this particular mine, which has fed about 4 million tons solid material with a feeding depth of 350m and safely exploited 3 million tons of coal.

Study on Future Prospects of Power Generation by Bagasse, Rice Husk and Municipal Waste in Uttar Pradesh

The use of bagasse, rice husk and municipal solid waste as a fuel for power generation can be an option to supplement the growing power demand as the conventional power source i.e. fossil fuel is diminishing day by day. So bagasse, rice husk and MSW have the substantial potential of such energy to be tapped in a synergistic manner. The potential of power generation by bagasse in Uttar Pradesh is 1400 MW which can replace approximately 560 tonne of coal otherwise. The green house emissions are also lower in the burning of bagasse reducing the environmental pollution. Also the potential of power generation by rice husk in Uttar Pradesh is 257.05 MW which is equivalent to energy of approximately 102 tonne of coal. At district Etawah the power generation by rice husk is approximately 9.45 MW. Likewise the potential of power generation by MSW in Uttar Pradesh is 258 MW which can save approximately 103 tonne of coal. If the power is generated by all these non conventional fuels in Uttar Pradesh then the overall power generation potential would be 1916.5MW equivalent to 766.42 tonne of coal. Even the blending of rice husk with the bagasse and MSW both is possible to have appreciable calorific value in case of scarcity of any one of three at a place. An effort is made here to study and analyze keeping the availability and environmental pollution in view of all these resources at district Etawah of Uttar Pradesh in the country.

Indonesia: Telling Lies

Indonesia: Telling Lies

Sustainable heating and cooling systems for agriculture

Space heating/cooling systems account for approximately 40% of the global energy consumption. Such systems contribute to global warming by emitting 4×1010 MWh of heat and 3×1010 tons of CO2. There is a general understanding that the way to reduce global warming is a more efficient use of energy and increased use of renewable energy in all fields of the society. Ground-coupled heating/cooling systems, which have proven to make huge contributions in reducing energy consumption in Europe and North America, is here applied for poultry industry in Syria, as an example for the Middle East. There are e.g. 13 000 chicken farms in Syria producing 172 000 tons of meat per year. This industry employs directly almost 150 000 people. The total investments in chicken farming are 130 BSP (2 B€). The annual mean air temperature in Syria is 15–18°C with winter temperatures close to freezing during two months. The chickens need a temperature of 21–35°C, depending on age, and the heating of all Syrian chicken plants consume 173×103 tons of coal (1196 GWh). In the summer time, the ambient air temperature in Syria could reach above 45°C. The chicken farms have no cooling systems since conventional cooling system is too expensive. The elevated temperature inside the farms reduces the chicken growth and lots of chicken die of overheating. The ground temperature at 10 m depth is roughly equal to the annual mean air temperature. Using the ground as a heat source means a sustainable and less expensive heating of the chicken farms. During the summer, the ground is used as a source for free cooling, i.e. used directly for cooling of the plants without any cooling machines. Current study shows the design and simulated operation of a ground-coupled heating/cooling system for a typical chicken farm in Syria. Performed national potential study showed that the implementation of such ground coupled heating and cooling systems in the Syrian poultry sector would mean increased poultry production and considerable savings in money, energy, and the environment. Copyright © 2010 John Wiley & Sons, Ltd.

Bamboo Wastes as Fuel in Industrial Boiler in China

: It is estimated that more than 500,000 industrial boilers (mostly stoker-fired) in China consume over 400 million tons of coal per year. Because of low efficiency (only 60-65 percent) of industrial boilers, the energy consumption and pollution emissions from industrial boilers rank second place in China’s industry. On the other hand, China is rich in bamboo resource, and bamboo forest area is more than 5 million hectares, and occupies more than 1/4 of the world’s total. However, the common utilization rate of bamboo timber’s physical processing is below 40% in weight, over 60% of bamboo timber becomes left over when processed. Bamboo wastes, compared with coal fuel, are a very clean and renewable and sustainable energy. Therefore, there is the requirement that coal fired industrial boiler change its fuel into bamboo wastes in China, and some suggestions for bamboo fired boiler are presented in this paper. It is well economy of bamboo fired boiler in the region of China where an abundance of bamboo wastes disposed.

Across the Mongolian Steppes

Across the Mongolian Steppes

Application of Hydroturbine Pump in Water Source Heat Pump Drainage Gravitational Potential Energy Recovery System

In this study, an energy recovery water source heat pump (ERWSHP) system has been developed and evaluated for feasibility, parameter efficiency and energy saving potential in comparison to conventional water source heat pump (WSHP) systems. The water discharged from the heat exchanger at a height, with an elevation difference of approximately 30 m in some areas of the mountainous city of Chongqing, was utilised as gravitational potential energy (GPE) which is converted into mechanical shaft power to drive the hydroturbine pump. A prototype of the system was set up, characterised, parameter tested and optimised in the laboratory at Chongqing University. MATLAB curve tool (cftool) was utilised to fit the characteristic curves under different water heads. The test data obtained were compared with the standard supplied data to ensure that the measurement was consistent with the performance expected. The system was validated by application to an off-site office development where the hourly cooling load during summer and heating load during winter was assessed using DeST-c (Designer’s Simulation Toolkits). The influence of the parameters was also evaluated. The energy-saving rates of ERWSHP systems in summer and winter were 37.5% and 60.1%, respectively, an equivalent to a fuel reduction of 14.7 tons of coal in summer and 31.8 tons during the winter. The use of GPE would also reduce water intake and increase the total transfer efficiency from 60% to 75% for the hydroturbine pump. A saving of 1131.01 kJ per year, a peak saving rate of 20.8%, in energy consumption could be achieved using the system.

ANALYSIS OF PERSPECTIVES OF USING REED RESOURCES IN LATGALE REGION

Increasing demand for energy, limited resources of fossil fuel, as well as pollution of the environment and changes of the global climate, have raised more interest in renewable resources. Support to the use of renewable resources has become a very important part of the European Union’s policy. The use of reeds like renewable energy resources allows saving fossil fuels. This paper presents the findings on the reed resources in lakes of Latgale (region in Latvia). The investigation of reed resources shows that the resources in the region are situated in a very uneven way. The greatest amount of reed resources is concentrated in the biggest lake in Latvia - Lubana Lake as well as near it. Using direct measurement methods and metering in the distance, it was stated that the total reed resources of Lubana Lake are 8,203? 2,999 tons, occupy 882 hectares and are situated in 429 reed blocks. Summary resources of Latgale region are 19,862? 7,409 tons. The amount of heat that can be obtained using reed resources of Latgale region is equivalent to 10,543 tons of natural gas or 8,802 tons of petroleum, or 13,092- 21,348 tons of coal (it depends on the heating of coal), or 7,675 tons of fuel, or 8,712 – 12,199 tons of oil (depends on the heating of oil).

Stirred Grinding of Coal Bottom Ash to Be Evaluated as a Cement Additive

By-product generation from coal combustion in coal-fired thermal power plants has been increasing worldwide and reached to 125 million tons in the U.S. and 100 million tons in Europe. Coal-fired thermal power plants have a share of about 20% in Turkey's electricity production. Almost 57 million tons of coal with varying ash content of 20–55% was consumed in those plants. Uranium and thorium radioactivity of ashes of low rank coals limits the use of ashes. Consuming local bituminous coals, Catalagzi Thermal Power Station has been producing 0.65 million tons of ash including fly ash (80%) and bottom ash (20%), which have a potential use in civil engineering. The majority of the fly ash has already been used in cement or directly in concrete mortars. This study was aimed to evaluate the bottom ash of the CATES. For this purpose, bottom ash was ground in a pilot scale set including a vertical stirring mill. The set had the controlled feeding, separation, and collection facilities to represent industrial scale grinding. Compressive strength tests were carried out on the ground bottom ash samples by mixing in varying amounts of Portland cement for curing times of 2, 7, 28, and 90 days. It was found that with a 25% ash containing cement a strength value of 48.86 Mpa which corresponds to 93.82% of strength of reference was obtained at 90 days curing time.

Comprehensive evaluation of effects of straw-based electricity generation: A Chinese case

Greater use of renewable energy is being aggressively promoted to combat climate change by the Chinese government and by other governments. Agricultural straw is the kind of renewable energy source that would become a pollution source if it is not well utilized. We select the Shiliquan straw-based electricity generation project in Shandong Province, China as a case and assess environmental externalities of straw utilization in power plants by using life-cycle analysis. Results show that straw-based electricity generation has far fewer greenhouse gas (GHG) emissions than that of coal-based electricity generation. Improvement in the energy efficiency of equipment used for straw’s pretreatment would lead to a decrease of GHG emissions and energy consumption in the life-cycle of straw-based electricity generation. In case 400 million tonnes of wasted straw in China could be used as a substitute for 200 million tonnes of coal, annually the straw 291 Terrawatt hours (TWh) of electricity could be generated, resulting in an annual total CO 2 emissions savings of 193 million tonnes. Straw-based electricity generation could be a high-potential alternative for electricity generation as well as an incentive for utilizing wheat straw instead of burning it in the field.

Relevance of Risk Capital and Margining for the Valuation of Power Plants: Cash Requirements for Credit Risk Mitigation

In the electricity sector, most of the trades are still done in the OTC market without direct mitigation of credit risk. Newer discussions fuelled by the European Commission (EUCOM 2009a,b) show that there is a political will to enforce a stronger collateralization policy on all European derivatives markets, including the OTC markets. This is meant to secure the markets and prohibit arbitrage on regulatory regimes as a consequence of the financial crisis. However, collateralization does not come for free. In this study, we analyze the capital needs for margining based on commodity prices of 2007- 2009 in conjunction with the clearing rules for margining of the European Commodity Clearing AG (ECC). We apply different hedging scenarios to state-of-the-art coal- and gas-fired power plants, and the sale of outright power in the German market. Based on the set-up of our analysis, we show that in absolute terms especially outright power has quite significant cash needs for trading, whereas coal-and gas-fired power plants have less than half the needs of outright power. In relative terms for the fossil-fired power plants, we find that coal-fired power plants have a relative advantage in comparison to gas-fired plants. The need for risk capital per MWhth of coal-fired power plants is comparably lower. A major reason for this is the standard notation of coal in US-$ per ton: As one ton of coal contains approx. 7 MWh of thermal energy (which is the relevant unit for the calculation of the fuel consumption), the price change for coal in US-$ (or €) per MWh is only approximately one seventh compared to the notation in metric tons. This translates into comparably lower margining needs for the fuel variation margin of a coal-fired power plant vs. a gas-fired power plant, offering a variety of further research questions.

Carbon from coal plants

In his review of Earth: The Sequel—The Race to Reinvent Energy and Stop Global Warming by Fred Krupp and Miriam Horn (Physics Today, April 2009, page 63), Mark Ratner paraphrases from the book that a typical 500-MW coal-fired power plant “emits roughly 1 ton of carbon dioxide for every kilowatt hour of electricity,” and he adds, “Such comparisons are easy to remember.” But this one is also easy to discredit: Since CO2 is about 25% carbon by weight, a 500-MW plant must therefore be consuming roughly 125 000 tons of coal per hour, or 3 million tons per day! The total daily coal production of the US is only 3 million tons.© 2010 American Institute of Physics.

Three-dimensional hybrid enterprise input–output model for material metabolism analysis: a case study of coal mines in China

China’s energy use has been, and will be for a long time, dominated by coal. The literature has studied little on the material metabolism of coal mines, especially for China, from a systems perspective. The aim of this study is to develop a quantitative framework to investigate the internal material metabolism of coal mining enterprises in China. This framework, three-dimensional hybrid enterprise input–output (3D-HEIO) model, combines scenario analysis and the enterprise input–output model. To illustrate the application of this framework, the material metabolism of Wang Coal-mine (WCM) in Shanxi, China is analyzed. Results show that the WCM has the annual potential to recover 10,862 tonnes of coal, reduce 404,515 tonnes of water consumption, 13 million kWh of electricity consumption, 70 tonnes of coagulant agents, 90,000 pieces of paper, and 146 tonnes of sulfur dioxide and dust emissions, and reuse 100,000 tonnes of coal gangue. The potential of economic profit can be 14.24 million yuan per year.

Recultivation and sustainable development of coal mining in Kolubara basin

Coal plays a fundamental role in global development, but the coal mining industry exerts impact on the environment, society and economy. Kolubara Coal Company produces about 30 million tonnes of coal, and digs about 70 million m3 of overburden per year. The main result of surface coal is certainly taking agricultural land, so that surface mines, which affect large areas in Kolubara, about 100 hectars a year, causing a number of problems related to the recultivation of degraded area after coal extraction. The lignite extraction through the method of opencast mining in Kolubara is about 60 years old. The previous exploitation usage is characterised by the fact that the disposal of overburden is made non-selectively, whereas the surface solum is not being preserved. The recultivation is carried out in parallel with overburden excavation. It is necessary to preserve the fertile solum through selective excavation in order to bring the soil back to its previous purpose - agricultural production. The objective of this paper is mainly to point out the need for the further expansion of the utilization of fossil fuels, which in turn reduces the emission of CO2, and thus reduces or prevents global climate changes on Earth. In addition to that, bringing back deteriorated terrains to their previous purpose - agricultural production, or the afforestation - contributes to the maintenance of ecological balance in nature, which then makes coal mining sustainable.

USGS Energy and Water Programs: Overview and Student Opportunities

The United States uses tremendous amounts of geologic energy resources. The world’s largest consumer of energy, the U.S. consumed 22.2 trillion cubic feet of natural gas, 1.1 billion short tons of coal (1 short ton equals 2000 pounds), and 7.6 billion barrels of oil in 2005 alone (Energy Information Administration 2007a, 2007b, 2007c). A forecast on total energy consumption in Figure 1a indicates that the Nation’s need for geologic energy sources will continue to grow. Production of these large quantities of energy requires large quantities of water. For example, the U.S. uses about 195 billion gallons of water a day, or 48 percent of its freshwater and saline-water withdrawals, to generate thermoelectric power (Figure 1b, Hutson et al. 2004.) Though water use has increased greatly since 1950, in spite of increasing energy demand the total amount of water use associated with power generation in the country has remained relatively steady over the past 20 years. This is due in part to Federal legislation that required stricter waterquality standards for discharge and consequent technological advances, including the recycling of cooling water in thermoelectric power plants (Hutson et al. 2004, Michelletti and Burns 2002). The use of biofuels in the United States is also increasing. The Energy Policy Act of 2005, Section 1501, mandates blending 7.5 billion gallons of ethanol and biodiesel into motor fuel by 2012 (Energy Policy Act 2005). In the coming years, additional water will be needed for irrigating new corn crops and for manufacturing biofuel from corn. In addition, increased corn acreage, particularly in

Coal-to-Liquids: Potential Impact on U.S. Coal Reserves

The production of liquid fuels from coal will very likely become an important part of the hydrocarbon energy mix of the future, provided that technical and environmental obstacles are overcome economically. The coal industry should be able to handle a coal-to-liquids (CTL) industry of modest size, using 60–70 million short tons or 54–64 million metric tonnes of coal per annum, without premature depletion of the country’s coal reserves. However, attempts to use CTL technology to replace all petroleum imports would deplete the nation’s coal reserves by the end of the century.