Evaluation of technical feasibility of closed-cycle non-equilibrium MHD power generation with direct coal firing. Final report, Task I

Energy Technology Data Exchange (ETDEWEB)

1981-11-01

Program accomplishments in a continuing effort to demonstrate the feasibility of direct coal-fired, closed-cycle MHD power generation are reported. This volume contains the following appendices: (A) user's manual for 2-dimensional MHD generator code (2DEM); (B) performance estimates for a nominal 30 MW argon segmented heater; (C) the feedwater cooled Brayton cycle; (D) application of CCMHD in an industrial cogeneration environment; (E) preliminary design for shell and tube primary heat exchanger; and (F) plant efficiency as a function of output power for open and closed cycle MHD power plants. (WHK)

Thermodynamic analysis and conceptual design for partial coal gasification air preheating coal-fired combined cycle

Science.gov (United States)

Xu, Yue; Wu, Yining; Deng, Shimin; Wei, Shirang

2004-02-01

The partial coal gasification air pre-heating coal-fired combined cycle (PGACC) is a cleaning coal power system, which integrates the coal gasification technology, circulating fluidized bed technology, and combined cycle technology. It has high efficiency and simple construction, and is a new selection of the cleaning coal power systems. A thermodynamic analysis of the PGACC is carried out. The effects of coal gasifying rate, pre-heating air temperature, and coal gas temperature on the performances of the power system are studied. In order to repower the power plant rated 100 MW by using the PGACC, a conceptual design is suggested. The computational results show that the PGACC is feasible for modernizing the old steam power plants and building the new cleaning power plants.

Evaluation of technical feasibility of closed-cycle non-equilibrium MHD power generation with direct coal firing. Final report, Task 1

Energy Technology Data Exchange (ETDEWEB)

1981-11-01

Program accomplishments in a continuing effort to demonstrate the feasibility of direct coal fired, closed cycle, magnetohydrodynamic power generation are detailed. These accomplishments relate to all system aspects of a CCMHD power generation system including coal combustion, heat transfer to the MHD working fluid, MHD power generation, heat and cesium seed recovery and overall systems analysis. Direct coal firing of the combined cycle has been under laboratory development in the form of a high slag rejection, regeneratively air cooled cyclone coal combustor concept, originated within this program. A hot bottom ceramic regenerative heat exchanger system was assembled and test fired with coal for the purposes of evaluating the catalytic effect of alumina on NO/sub x/ emission reduction and operability of the refractory dome support system. Design, procurement, fabrication and partial installation of a heat and seed recovery flow apparatus was accomplished and was based on a stream tube model of the full scale system using full scale temperatures, tube sizes, rates of temperature change and tube geometry. Systems analysis capability was substantially upgraded by the incorporation of a revised systems code, with emphasis on ease of operator interaction as well as separability of component subroutines. The updated code was used in the development of a new plant configuration, the Feedwater Cooled (FCB) Brayton Cycle, which is superior to the CCMHD/Steam cycle both in performance and cost. (WHK)

The future of integrated coal gasification combined cycle power plants

International Nuclear Information System (INIS)

Mueller, R.; Termuehlen, H.

1991-01-01

This paper examines the future of integrated coal gasification combined cycle (IGCC) power plants as affected by various technical, economical and environmental trends in power generation. The topics of the paper include a description of natural gas-fired combined cycle power plants, IGCC plants, coal gasifier concepts, integration of gasifiers into combined cycle power plants, efficiency, environmental impacts, co-products of IGCC power plants, economics of IGCC power plants, and a review of IGCC power plant projects

Design and development of gas cooled reactors with closed cycle gas turbines. Proceedings of a technical committee meeting

International Nuclear Information System (INIS)

1996-08-01

Technological advances over the past fifteen years in the design of turbomachinery, recuperators and magnetic bearings provide the potential for a quantum improvement in nuclear power generation economics through the use of the HTGR with a closed cycle gas turbine. Enhanced international co-operation among national gas cooled reactor programmes in these common technology areas could facilitate the development of this nuclear power concept thereby achieving safety, environmental and economic benefits with overall reduced development costs. This TCM and Workshop was convened to provide the opportunity to review and examine the status of design activities and technology development in national HTGR programmes with specific emphasis on the closed cycle gas turbine, and to identify pathways which take advantage of the opportunity for international co-operation in the development of this concept. Refs, figs, tabs

Design and development of gas cooled reactors with closed cycle gas turbines. Proceedings of a technical committee meeting

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-08-01

Technological advances over the past fifteen years in the design of turbomachinery, recuperators and magnetic bearings provide the potential for a quantum improvement in nuclear power generation economics through the use of the HTGR with a closed cycle gas turbine. Enhanced international co-operation among national gas cooled reactor programmes in these common technology areas could facilitate the development of this nuclear power concept thereby achieving safety, environmental and economic benefits with overall reduced development costs. This TCM and Workshop was convened to provide the opportunity to review and examine the status of design activities and technology development in national HTGR programmes with specific emphasis on the closed cycle gas turbine, and to identify pathways which take advantage of the opportunity for international co-operation in the development of this concept. Refs, figs, tabs.

Economic aspects of advanced coal-fired gas turbine locomotives

Science.gov (United States)

Liddle, S. G.; Bonzo, B. B.; Houser, B. C.

1983-01-01

Increases in the price of such conventional fuels as Diesel No. 2, as well as advancements in turbine technology, have prompted the present economic assessment of coal-fired gas turbine locomotive engines. A regenerative open cycle internal combustion gas turbine engine may be used, given the development of ceramic hot section components. Otherwise, an external combustion gas turbine engine appears attractive, since although its thermal efficiency is lower than that of a Diesel engine, its fuel is far less expensive. Attention is given to such a powerplant which will use a fluidized bed coal combustor. A life cycle cost analysis yields figures that are approximately half those typical of present locomotive engines.

Gas Permeability Evolution Mechanism and Comprehensive Gas Drainage Technology for Thin Coal Seam Mining

Directory of Open Access Journals (Sweden)

Fangtian Wang

2017-09-01

Full Text Available A thin coal seam mined as a protective coal seam above a gas outburst coal seam plays a central role in decreasing the degree of stress placed on a protected seam, thus increasing gas permeability levels and desorption capacities to dramatically eliminate gas outburst risk for the protected seam. However, when multiple layers of coal seams are present, stress-relieved gas from adjacent coal seams can cause a gas explosion. Thus, the post-drainage of gas from fractured and de-stressed strata should be applied. Comprehensive studies of gas permeability evolution mechanisms and gas seepage rules of protected seams close to protective seams that occur during protective seam mining must be carried out. Based on the case of the LongWall (LW 23209 working face in the Hancheng coal mine, Shaanxi Province, this paper presents a seepage model developed through the FLAC3D software program (version 5.0, Itasca Consulting Group, Inc., Minneapolis, MI, USA from which gas flow characteristics can be reflected by changes in rock mass permeability. A method involving theoretical analysis and numerical simulation was used to analyze stress relief and gas permeability evolution mechanisms present during broken rock mass compaction in a goaf. This process occurs over a reasonable amount of extraction time and in appropriate locations for comprehensive gas extraction technologies. In using this comprehensive gas drainage technological tool, the safe and efficient co-extraction of thin coal seams and gas resources can be realized, thus creating a favorable environment for the safe mining of coal and gas outburst seams.

Conceptual design study of closed Brayton cycle gas turbines for fusion power generation

International Nuclear Information System (INIS)

Kuo, S.C.

1976-01-01

A conceptual design study is presented of closed Brayton cycle gas turbine power conversion systems suitable for integration with advanced-concept Tokamak fusion reactors (such as UWMAK-III) for efficient power generation without requiring cooling water supply for waste heat rejection. A baseline cycle configuration was selected and parametric performance analyses were made. Based on the results of the parametric analysis and trade-off and interface considerations, the reference design conditions for the baseline cycle were selected. Conceptual designs were made of the major helium gas turbine power system components including a 585-MWe single-shaft turbomachine, (three needed), regenerator, precooler, intercooler, and the piping system connecting them. Structural configuration and significant physical dimensions for major components are illustrated, and a brief discussion on major advantages, power control and crucial technologies for the helium gas turbine power system are presented

Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 1: Introduction and summary and general assumptions. [energy conversion systems for electric power plants using coal - feasibility

Science.gov (United States)

Beecher, D. T.

1976-01-01

Nine advanced energy conversion concepts using coal or coal-derived fuels are summarized. They are; (1) open-cycle gas turbines, (2) combined gas-steam turbine cycles, (3) closed-cycle gas turbines, (4) metal vapor Rankine topping, (5) open-cycle MHD; (6) closed-cycle MHD; (7) liquid-metal MHD; (8) advanced steam; and (9) fuel cell systems. The economics, natural resource requirements, and performance criteria for the nine concepts are discussed.

Biomass fueled closed cycle gas turbine with water injection

Energy Technology Data Exchange (ETDEWEB)

Bardi, Silvia [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Chemical Engineering and Technology

2001-01-01

Direct water injection has been studied for a small scale ({approx} 8 MW fuel input) closed cycle gas turbine coupled to a biomass fueled CFB furnace. Two different working fluids have been considered (helium-water mixture and nitrogen-water mixture). The water injection could take place between the compressor stages, as an intercooler, or after the high pressure compressor, as an aftercooler. Both this options have been studied, varying the relative humidity levels after the injection and the temperatures of the injected water. The effect of water injection on thermodynamic properties of the working fluids has been studied, together with its effect on turbomachinery isentropic efficiency. A sensitivity analysis on turbomachinery efficiency and cycle base pressure has been included. The results from this study have been compared to the performance of a dry closed cycle without water injection. The wet cycle shows an electric efficiency in the range 29-32% with helium-water mixture as working fluid and 30-32% with nitrogen-water mixture as working fluid, while the total efficiency (referring to the fuel LHV) is always higher than 100%. In the non-injected cycle the electric efficiency is 30-35% with helium and 32-36 with nitrogen. The total efficiency in the dry case with two level intercooling and postcooling is 87-89%, while is higher than 100% when only one stage inter- and postcooling is present. Aside from this, the study also includes a sizing of the heat exchangers for the different cycle variations. The heat transfer area is very sensible to the working fluid and to the amount of injected water and it's always higher when a nitrogen-water mixture is used. Compared to the cycle without water injection, by the way, the number of heat exchangers is reduced. This will lead to a lower pressure drop and a simpler plant layout. The total heat transfer area, however, is higher in the wet cycle than in the dry cycle.

Closed-cycle gas flow system for cooling a HTc dc-SQUID magnetometer

NARCIS (Netherlands)

Bosch, van den P.J.; Holland, H.J.; Brake, ter H.J.M.; Rogalla, H.

1994-01-01

A closed-cycle gas flow system for cooling a high-crit. temp. d.c.-superconducting quantum interference device (SQUID) magnetometer by means of a cryocooler has been designed, constructed and tested. The magnetometer is aimed to measure heart signals with a sensitivity of 0.1 pT/Hz1/2. The required

The exploitation of the physical exergy of liquid natural gas by closed power thermodynamic cycles. An overview

International Nuclear Information System (INIS)

Invernizzi, Costante M.; Iora, Paolo

2016-01-01

The world trade in LNG (liquefied natural gas) has tripled in the last 15 years and the forecasts are for its further rapid expansion. Although the cryogenic exergy of the LNG could be used in many industrial processes, it is recognized also as a source for power cycles. When using the low temperature capacity of LNG for power production, several thermodynamic cycles can be considered. This paper reports the state-of-the art of the most relevant solutions based on conventional and non-conventional thermodynamic closed cycles. Moreover, a novel metrics framework, suitable for a fairer comparison among the energy recovery performances of the different technologies is proposed. According to the defined indicators the compounds plants with gas turbine and closed Brayton cycles perform really better, with an almost full use of LNG available cold temperature and a fuel consumption with an efficiency better than that of the current combined cycles. The Rankine cycles with organic working fluids (pure fluids or non-azeotropic mixtures) using seawater or heat available at low temperature (for instance at 150 °C) also perform in a very satisfactory way. Real gas Brayton cycles and carbon dioxide condensation cycles work with very good thermal efficiency also at relatively low maximum temperatures (300 ÷ 600 °C) and could have peculiar applications. - Highlights: • A review of systems for the combined re-gasification of LNG and generation of power. • The considered systems are: closed Brayton cycles, condensation cycles, gas turbines. • Definition of new parameters for an energy assessment of the systems? performances. • A comparison among the various systems from the energy point of view.

Gas and coal competition in the EU power sector

International Nuclear Information System (INIS)

Cornot-Gandolphe, Sylvie

2014-01-01

According to a new report by CEDIGAZ, the International Centre for Natural Gas Information, gas has lost its attractiveness against coal in the EU power sector. Its demand by the sector decreased by one third during the past three years and its prospects are very weak in this decade. The Association warns that un-profitability of combined cycle gas turbines (CCGTs) and the retirement of old coal plants due to stringent air regulation may lead to the closure of one third of the current fleet and poses a serious security of supply issue that has to be addressed urgently

An advanced conceptual Tokamak fusion power reactor utilizing closed cycle helium gas turbines

International Nuclear Information System (INIS)

Conn, R.W.

1976-01-01

UWMAK-III is a conceptual Tokamak reactor designed to study the potential and the problems associated with an advanced version of Tokamaks as power reactors. Design choices have been made which represent reasonable extrapolations of present technology. The major features are the noncircular plasma cross section, the use of TZM, a molybdenum based alloy, as the primary structural material, and the incorporation of a closed-cycle helium gas turbine power conversion system. A conceptual design of the turbomachinery is given together with a preliminary heat exchanger analysis that results in relatively compact designs for the generator, precooler, and intercooler. This paper contains a general description of the UWMAK-III system and a discussion of those aspects of the reactor, such as the burn cycle, the blanket design and the heat transfer analysis, which are required to form the basis for discussing the power conversion system. The authors concentrate on the power conversion system and include a parametric performance analysis, an interface and trade-off study and a description of the reference conceptual design of the closed-cycle helium gas turbine power conversion system. (Auth.)

Externally-fired combined cycle: An effective coal fueled technology for repowering and new generation

Energy Technology Data Exchange (ETDEWEB)

Stoddard, L.E.; Bary, M.R. [Black and Veatch, Kansas City, MO (United States); Gray, K.M. [Pennsylvania Electric Co., Johnstown, PA (United States); LaHaye, P.G. [Hague International, South Portland, ME (United States)

1995-06-01

The Externally-Fired Combined Cycle (EFCC) is an attractive emerging technology for powering high efficiency combined gas and steam turbine cycles with coal or other ash bearing fuels. In the EFCC, the heat input to a gas turbine is supplied indirectly through a ceramic air heater. The air heater, along with an atmospheric coal combustor and ancillary equipment, replaces the conventional gas turbine combustor. A steam generator located downstream from the ceramic air heater and steam turbine cycle, along with an exhaust cleanup system, completes the combined cycle. A key element of the EFCC Development Program, the 25 MMBtu/h heat-input Kennebunk Test Facility (KTF), has recently begun operation. The KTF has been operating with natural gas and will begin operating with coal in early 1995. The US Department of Energy selected an EFCC repowering of the Pennsylvania Electric Company`s Warren Station for funding under the Clean Coal Technology Program Round V. The project focuses on repowering an existing 48 MW (gross) steam turbine with an EFCC power island incorporating a 30 MW gas turbine, for a gross power output of 78 MW and a net output of 72 MW. The net plant heat rate will be decreased by approximately 30% to below 9,700 Btu/kWh. Use of a dry scrubber and fabric filter will reduce sulfur dioxide (SO{sub 2}) and particulate emissions to levels under those required by the Clean Air Act Amendments (CAAA) of 1990. Nitrogen oxides (NO{sub x}) emissions are controlled by the use of staged combustion. The demonstration project is currently in the engineering phase, with startup scheduled for 1997. This paper discusses the background of the EFCC, the KTF, the Warren Station EFCC Clean Coal Technology Demonstration Project, the commercial plant concept, and the market potential for the EFCC.

Dependence of cycle optimal configuration for closed gas turbines on thermodynamic properties of working fluids

International Nuclear Information System (INIS)

Andryushchenko, A.I.; Dubinin, A.B.; Krylov, E.E.

1988-01-01

The problem of choice of working fluids for NPP closed gas turbines (CGT) is discussed. Thermostable in the working temperature range, chemically inert relatively to structural materials, fire- and explosion - proof substances, radiation-resistant and having satisfactory neutron-physical characteristics are used as the working fluids. Final choice of a gas as a working fluid is exercised based on technical and economic comparison of different variants at optimum thermodynamic cycle and parameters for each gas. The character and degree of the effect of thermodynamic properties of gases on configuration of reference cycles of regenerative CGT are determined. It is established that efficiency and optimum parameters in nodal points of the reference cycle are specified by the degree of removing the compression processes from the critical point. Practical importance of the obtained results presupposes the possibility of rapid estimation of the efficiency of using a gas without multiparametric optimization

Experimental Research on the Impactive Dynamic Effect of Gas-Pulverized Coal of Coal and Gas Outburst

Directory of Open Access Journals (Sweden)

Haitao Sun

2018-03-01

Full Text Available Coal and gas outburst is one of the major serious natural disasters during underground coal, and the shock air flow produced by outburst has a huge threat on the mine safety. In order to study the two-phase flow of a mixture of pulverized coal and gas of a mixture of pulverized coal and gas migration properties and its shock effect during the process of coal and gas outburst, the coal samples of the outburst coal seam in Yuyang Coal Mine, Chongqing, China were selected as the experimental subjects. By using the self-developed coal and gas outburst simulation test device, we simulated the law of two-phase flow of a mixture of pulverized coal and gas in the roadway network where outburst happened. The results showed that the air in the roadway around the outburst port is disturbed by the shock wave, where the pressure and temperature are abruptly changed. For the initial gas pressure of 0.35 MPa, the air pressure in different locations of the roadway fluctuated and eventually remain stable, and the overpressure of the outburst shock wave was about 20~35 kPa. The overpressure in the main roadway and the distance from the outburst port showed a decreasing trend. The highest value of temperature in the roadway increased by 0.25 °C and the highest value of gas concentration reached 38.12% during the experiment. With the action of shock air flow, the pulverized coal transportation in the roadway could be roughly divided into three stages, which are the accelerated movement stage, decelerated movement stage and the particle settling stage respectively. Total of 180.7 kg pulverized coal of outburst in this experiment were erupted, and most of them were accumulated in the main roadway. Through the analysis of the law of outburst shock wave propagation, a shock wave propagation model considering gas desorption efficiency was established. The relationships of shock wave overpressure and outburst intensity, gas desorption rate, initial gas pressure, cross

HTGR-GT closed-cycle gas turbine: a plant concept with inherent cogeneration (power plus heat production) capability

International Nuclear Information System (INIS)

McDonald, C.F.

1980-04-01

The high-grade sensible heat rejection characteristic of the high-temperature gas-cooled reactor-gas turbine (HTGR-GT) plant is ideally suited to cogeneration. Cogeneration in this nuclear closed-cycle plant could include (1) bottoming Rankine cycle, (2) hot water or process steam production, (3) desalination, and (4) urban and industrial district heating. This paper discusses the HTGR-GT plant thermodynamic cycles, design features, and potential applications for the cogeneration operation modes. This paper concludes that the HTGR-GT plant, which can potentially approach a 50% overall efficiency in a combined cycle mode, can significantly aid national energy goals, particularly resource conservation

Reduction of impurity contamination in a working gas for closed-cycle MHD power generation

International Nuclear Information System (INIS)

Endo, N.; Yoshikawa, K.; Shioda, S.

1989-01-01

The reduction of impurity contamination in a working inert gas for closed-cycle MHD power generation is examined. A conceptual operation system of regenerative heat exchangers is proposed for minimizing the amount of combustion gas which mixes in the working inert gas. Experiments have shown that this mixing can be reduced significantly by evacuating and flushing the heat exchangers after being heated by combustion gas. Calculations have shown that, among the main molecular contaminants in the working inert gas, CO 2 , H 2 O and O 2 can be removed as compounds with the seed material, while N 2 and H 2 can be reduced by a partial purification of the circulating working inert gas. (author)

Nuclear closed-cycle gas turbine (HTGR-GT): dry cooled commercial power plant studies

International Nuclear Information System (INIS)

McDonald, C.F.; Boland, C.R.

1979-11-01

Combining the modern and proven power conversion system of the closed-cycle gas turbine (CCGT) with an advanced high-temperature gas-cooled reactor (HTGR) results in a power plant well suited to projected utility needs into the 21st century. The gas turbine HTGR (HTGR-GT) power plant benefits are consistent with national energy goals, and the high power conversion efficiency potential satisfies increasingly important resource conservation demands. Established technology bases for the HTGR-GT are outlined, together with the extensive design and development program necessary to commercialize the nuclear CCGT plant for utility service in the 1990s. This paper outlines the most recent design studies by General Atomic for a dry-cooled commercial plant of 800 to 1200 MW(e) power, based on both non-intercooled and intercooled cycles, and discusses various primary system aspects. Details are given of the reactor turbine system (RTS) and on integrating the major power conversion components in the prestressed concrete reactor vessel

Report on studies on closed cycle MHD power generation; Closed cycle MHD hatsuden kento hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1991-04-01

Summarized herein are results of the studies on closed cycle MHD (CCMHD) power generation by the study committee. The studied system is based on the MHD gas turbine combined Brayton cycle of about 500,000 kW in output power, firing natural gas as the fuel, and the conceptual design works therefor are completed. The major findings are: the overall plant efficiency: 54.2% at the power transmission side, plot area required per unit power output: 0.04 m{sup 2}/KW, unit construction cost: 251,000 yen/KW, and unit power generation cost: 10.2 yen/KWh. This system will be more operable than the gas turbine combined cycle with steam system, because start-up time, output change rate, optimum load and so on are constrained not on the power generator side but on the gas turbine side. The expected environmental effects include the exhaust gas NOX concentration being equivalent with that associated with the conventional power generator of 2-stage combustion system, quantity of combustion gases to be treated being approximately 40% of that associated with the gas turbine combined cycle, and reduced CO2 gas emissions, resulting from enhanced power generation efficiency. It is expected that the CCMHD system can exhibit higher efficiency than the high-temperature gas turbine combined cycle system. (NEDO)

Summary of workshop on materials issues in low emission boilers and high efficiency coal-fired cycles

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-01

The purpose of the workshop was to review with experts in the field the materials issues associated with two of the primary coal power systems being developed by the DOE Office of Fossil Energy. The DOE-FE Advanced Power Systems Program includes natural gas-based and coal-based power systems. Major activities in the natural gas-based power systems area include the Advanced Turbine Systems (ATS) Program, the Fuel Cells Program, and Hybrid Cycles. The coal-based power systems projects include the Low Emissions Boiler Systems (LEBS) Program, the High-Performance Power Systems Program (HIPPS), the Integrated (Coal) Gasification Combined-Cycle Program, and the Fluidized-Bed Combustion Program. This workshop focused on the materials issues associated with the LEBS and HIPPS technologies.

Coal and gas competition in global markets

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-07-01

Global consumption of commercial energy totalled 18 Gt of coal equivalent in 2010. With a 28% share, coal ranked second after oil as one of the major sources of primary energy and natural gas (at 21%) ranked third. Gross power generation with coal was approximately 41% and gas 22%. Natural gas as a global commodity is growing rapidly with the advent of unconventional sources such as shale gas. Recently, gas has become the fuel of choice for new power generating plants in some countries. Overall production of coal has increased in the same time-frame. The share of coal in electricity production was constant in Europe from early 2000 but recently increased. This was due to the high cost of gas in Europe and a low emissions penalty levied by the regulator, making coal currently more competitive in Europe compared to gas. Coal utilisation continues to increase in Asia but is facing serious competition with gas in the USA, where the share of electricity generated with coal dropped in 2012. However, natural gas used to generate electricity in early 2013 was below the high level seen during the comparable 2012 period, when low natural gas prices led to significant displacement of coal by natural gas for power generation. The current consensus in the USA is that while coal may recover ground in the short term, it loses in the long term as coal plants are retired. The discovery, production and availability of significant amounts of gas have implications for not only the price of natural gas but also the price of coal as well as supply and demand, and utilisation of both fuels internationally. The interaction between coal and gas in the global markets today is investigated in this review and the near-term outlook and impact on both fuels is presented. In this report, reserves, production and trade, supply and demand, pricing, utilisation and consumption, public attitudes and finally near/short to medium-term prospects are discussed for both coal and gas.

Strategic considerations for clean coal R and D

International Nuclear Information System (INIS)

McMullan, J.T.; Williams, B.C.; McCahey, S.

2001-01-01

While present interest in coal-fired power generation is centred on the developing countries, with new natural-gas-fired power stations predominating in the developed world, in the long term coal will return to being the fuel of choice for power generation for much of the world. To minimise the global impact of coal use it is essential, therefore, that coal technologies are developed that are efficient, clean and economically attractive. Techno-economic analyses of the options for coal are presented together with a strategic overview of potential lines of development. The broad conclusions are that new coal plants will not be truly competitive with natural gas until the price of gas increases to about 3.3 EURO/GJ, compared with a coal price of 1.3 EURO/GJ. Present state-of-the-art pulverised coal-fired plant is close to its optimum techno-economic performance and further improvements depend on the development of cost-effective super-alloys. However, there are good opportunities to increase the efficiency of coal use to greater than 50% (LHV basis) using gasification-based power generation cycles. Unless credit is given for the much lower emissions provided by these cycles, the pulverised coal and pressurised fluidised bed combustion will remain the most economic options. (author)

Coal beneficiation by gas agglomeration

Science.gov (United States)

Wheelock, Thomas D.; Meiyu, Shen

2003-10-14

Coal beneficiation is achieved by suspending coal fines in a colloidal suspension of microscopic gas bubbles in water under atmospheric conditions to form small agglomerates of the fines adhered by the gas bubbles. The agglomerates are separated, recovered and resuspended in water. Thereafter, the pressure on the suspension is increased above atmospheric to deagglomerate, since the gas bubbles are then re-dissolved in the water. During the deagglomeration step, the mineral matter is dispersed, and when the pressure is released, the coal portion of the deagglomerated gas-saturated water mixture reagglomerates, with the small bubbles now coming out of the solution. The reagglomerate can then be separated to provide purified coal fines without the mineral matter.

Geological evaluation on productibility of coal seam gas; Coal seam gas no chishitsugakuteki shigen hyoka ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Fujii, K [University of Shizuoka, Shizuoka (Japan). Faculty of Education

1996-09-01

Coal seam gas is also called coal bed methane gas, indicating the gas existing in coal beds. The gas is distinguished from the oil field based gas, and also called non-conventional type gas. Its confirmed reserve is estimated to be 24 trillion m {sup 3}, with the trend of its development seen worldwide as utilization of unused resource. For the necessity of cultivating relevant technologies in Japan, this paper considers processes of production, movement, stockpiling, and accumulation of the gas. Its productibility is controlled by thickness of a coal bed, degree of coalification, gas content, permeability, groundwater flow, and deposition structure. Gas generation potential is evaluated by existing conditions of coal and degree of coalification, and methane production by biological origin and thermal origin. Economically viable methane gas is mainly of the latter origin. Evaluating gas reserve potential requires identification of the whole mechanism of adsorption, accumulation and movement of methane gas. The gas is expected of effect on environmental aspects in addition to availability as utilization of unused energy. 5 figs.

Life Cycle Greenhouse Gas Emissions from Electricity Generation: A Comparative Analysis of Australian Energy Sources

Directory of Open Access Journals (Sweden)

Robert G. Hynes

2012-03-01

Full Text Available Electricity generation is one of the major contributors to global greenhouse gas emissions. Transitioning the World’s energy economy to a lower carbon future will require significant investment in a variety of cleaner technologies, including renewables and nuclear power. In the short term, improving the efficiency of fossil fuel combustion in energy generation can provide an important contribution. Availability of life cycle GHG intensity data will allow decision-makers to move away from overly simplistic assertions about the relative merits of certain fuels, and focus on the complete picture, especially the critical roles of technology selection and application of best practice. This analysis compares the life-cycle greenhouse gas (GHG intensities per megawatt-hour (MWh of electricity produced for a range of Australian and other energy sources, including coal, conventional liquefied natural gas (LNG, coal seam gas LNG, nuclear and renewables, for the Australian export market. When Australian fossil fuels are exported to China, life cycle greenhouse gas emission intensity in electricity production depends to a significant degree on the technology used in combustion. LNG in general is less GHG intensive than black coal, but the gap is smaller for gas combusted in open cycle gas turbine plant (OCGT and for LNG derived from coal seam gas (CSG. On average, conventional LNG burned in a conventional OCGT plant is approximately 38% less GHG intensive over its life cycle than black coal burned in a sub-critical plant, per MWh of electricity produced. However, if OCGT LNG combustion is compared to the most efficient new ultra-supercritical coal power, the GHG intensity gap narrows considerably. Coal seam gas LNG is approximately 13–20% more GHG intensive across its life cycle, on a like-for like basis, than conventional LNG. Upstream fugitive emissions from CSG (assuming best practice gas extraction techniques do not materially alter the life cycle

Gas--steam turbine combined cycle power plants

Energy Technology Data Exchange (ETDEWEB)

Christian, J.E.

1978-10-01

The purpose of this technology evaluation is to provide performance and cost characteristics of the combined gas and steam turbine, cycle system applied to an Integrated Community Energy System (ICES). To date, most of the applications of combined cycles have been for electric power generation only. The basic gas--steam turbine combined cycle consists of: (1) a gas turbine-generator set, (2) a waste-heat recovery boiler in the gas turbine exhaust stream designed to produce steam, and (3) a steam turbine acting as a bottoming cycle. Because modification of the standard steam portion of the combined cycle would be necessary to recover waste heat at a useful temperature (> 212/sup 0/F), some sacrifice in the potential conversion efficiency is necessary at this temperature. The total energy efficiency ((electric power + recovered waste heat) divided by input fuel energy) varies from about 65 to 73% at full load to 34 to 49% at 20% rated electric power output. Two major factors that must be considered when installing a gas--steam turbine combines cycle are: the realiability of the gas turbine portion of the cycle, and the availability of liquid and gas fuels or the feasibility of hooking up with a coal gasification/liquefaction process.

Model of environmental life cycle assessment for coal mining operations

Energy Technology Data Exchange (ETDEWEB)

Burchart-Korol, Dorota, E-mail: dburchart@gig.eu; Fugiel, Agata, E-mail: afugiel@gig.eu; Czaplicka-Kolarz, Krystyna, E-mail: kczaplicka@gig.eu; Turek, Marian, E-mail: mturek@gig.eu

2016-08-15

This paper presents a novel approach to environmental assessment of coal mining operations, which enables assessment of the factors that are both directly and indirectly affecting the environment and are associated with the production of raw materials and energy used in processes. The primary novelty of the paper is the development of a computational environmental life cycle assessment (LCA) model for coal mining operations and the application of the model for coal mining operations in Poland. The LCA model enables the assessment of environmental indicators for all identified unit processes in hard coal mines with the life cycle approach. The proposed model enables the assessment of greenhouse gas emissions (GHGs) based on the IPCC method and the assessment of damage categories, such as human health, ecosystems and resources based on the ReCiPe method. The model enables the assessment of GHGs for hard coal mining operations in three time frames: 20, 100 and 500 years. The model was used to evaluate the coal mines in Poland. It was demonstrated that the largest environmental impacts in damage categories were associated with the use of fossil fuels, methane emissions and the use of electricity, processing of wastes, heat, and steel supports. It was concluded that an environmental assessment of coal mining operations, apart from direct influence from processing waste, methane emissions and drainage water, should include the use of electricity, heat and steel, particularly for steel supports. Because the model allows the comparison of environmental impact assessment for various unit processes, it can be used for all hard coal mines, not only in Poland but also in the world. This development is an important step forward in the study of the impacts of fossil fuels on the environment with the potential to mitigate the impact of the coal industry on the environment. - Highlights: • A computational LCA model for assessment of coal mining operations • Identification of

Model of environmental life cycle assessment for coal mining operations

International Nuclear Information System (INIS)

Burchart-Korol, Dorota; Fugiel, Agata; Czaplicka-Kolarz, Krystyna; Turek, Marian

2016-01-01

This paper presents a novel approach to environmental assessment of coal mining operations, which enables assessment of the factors that are both directly and indirectly affecting the environment and are associated with the production of raw materials and energy used in processes. The primary novelty of the paper is the development of a computational environmental life cycle assessment (LCA) model for coal mining operations and the application of the model for coal mining operations in Poland. The LCA model enables the assessment of environmental indicators for all identified unit processes in hard coal mines with the life cycle approach. The proposed model enables the assessment of greenhouse gas emissions (GHGs) based on the IPCC method and the assessment of damage categories, such as human health, ecosystems and resources based on the ReCiPe method. The model enables the assessment of GHGs for hard coal mining operations in three time frames: 20, 100 and 500 years. The model was used to evaluate the coal mines in Poland. It was demonstrated that the largest environmental impacts in damage categories were associated with the use of fossil fuels, methane emissions and the use of electricity, processing of wastes, heat, and steel supports. It was concluded that an environmental assessment of coal mining operations, apart from direct influence from processing waste, methane emissions and drainage water, should include the use of electricity, heat and steel, particularly for steel supports. Because the model allows the comparison of environmental impact assessment for various unit processes, it can be used for all hard coal mines, not only in Poland but also in the world. This development is an important step forward in the study of the impacts of fossil fuels on the environment with the potential to mitigate the impact of the coal industry on the environment. - Highlights: • A computational LCA model for assessment of coal mining operations • Identification of

Environmental implications of United States coal exports: a comparative life cycle assessment of future power system scenarios.

Science.gov (United States)

Bohnengel, Barrett; Patiño-Echeverri, Dalia; Bergerson, Joule

2014-08-19

Stricter emissions requirements on coal-fired power plants together with low natural gas prices have contributed to a recent decline in the use of coal for electricity generation in the United States. Faced with a shrinking domestic market, many coal companies are taking advantage of a growing coal export market. As a result, U.S. coal exports hit an all-time high in 2012, fueled largely by demand in Asia. This paper presents a comparative life cycle assessment of two scenarios: a baseline scenario in which coal continues to be burned domestically for power generation, and an export scenario in which coal is exported to Asia. For the coal export scenario we focus on the Morrow Pacific export project being planned in Oregon by Ambre Energy that would ship 8.8 million tons of Powder River Basin (PRB) coal annually to Asian markets via rail, river barge, and ocean vessel. Air emissions (SOx, NOx, PM10 and CO2e) results assuming that the exported coal is burned for electricity generation in South Korea are compared to those of a business as usual case in which Oregon and Washington's coal plants, Boardman and Centralia, are retrofitted to comply with EPA emissions standards and continue their coal consumption. Findings show that although the environmental impacts of shipping PRB coal to Asia are significant, the combination of superior energy efficiency among newer South Korean coal-fired power plants and lower emissions from U.S. replacement of coal with natural gas could lead to a greenhouse gas reduction of 21% in the case that imported PRB coal replaces other coal sources in this Asian country. If instead PRB coal were to replace natural gas or nuclear generation in South Korea, greenhouse gas emissions per unit of electricity generated would increase. Results are similar for other air emissions such as SOx, NOx and PM. This study provides a framework for comparing energy export scenarios and highlights the importance of complete life cycle assessment in

WABASH RIVER COAL GASIFICATION REPOWERING PROJECT

Energy Technology Data Exchange (ETDEWEB)

Unknown

2000-09-01

The close of 1999 marked the completion of the Demonstration Period of the Wabash River Coal Gasification Repowering Project. This Final Report summarizes the engineering and construction phases and details the learning experiences from the first four years of commercial operation that made up the Demonstration Period under Department of Energy (DOE) Cooperative Agreement DE-FC21-92MC29310. This 262 MWe project is a joint venture of Global Energy Inc. (Global acquired Destec Energy's gasification assets from Dynegy in 1999) and PSI Energy, a part of Cinergy Corp. The Joint Venture was formed to participate in the Department of Energy's Clean Coal Technology (CCT) program and to demonstrate coal gasification repowering of an existing generating unit impacted by the Clean Air Act Amendments. The participants jointly developed, separately designed, constructed, own, and are now operating an integrated coal gasification combined-cycle power plant, using Global Energy's E-Gas{trademark} technology (E-Gas{trademark} is the name given to the former Destec technology developed by Dow, Destec, and Dynegy). The E-Gas{trademark} process is integrated with a new General Electric 7FA combustion turbine generator and a heat recovery steam generator in the repowering of a 1950's-vintage Westinghouse steam turbine generator using some pre-existing coal handling facilities, interconnections, and other auxiliaries. The gasification facility utilizes local high sulfur coals (up to 5.9% sulfur) and produces synthetic gas (syngas), sulfur and slag by-products. The Project has the distinction of being the largest single train coal gasification combined-cycle plant in the Western Hemisphere and is the cleanest coal-fired plant of any type in the world. The Project was the first of the CCT integrated gasification combined-cycle (IGCC) projects to achieve commercial operation.

Life cycle environmental impacts of UK shale gas

International Nuclear Information System (INIS)

Stamford, Laurence; Azapagic, Adisa

2014-01-01

Highlights: • First full life cycle assessment of shale gas used for electricity generation. • Comparison with coal, conventional and liquefied gas, nuclear, wind and solar PV. • Shale gas worse than coal for three impacts and better than renewables for four. • It has higher photochemical smog and terrestrial toxicity than the other options. • Shale gas a sound environmental option only if accompanied by stringent regulation. - Abstract: Exploitation of shale gas in the UK is at a very early stage, but with the latest estimates suggesting potential resources of 3.8 × 10 13 cubic metres – enough to supply the UK for next 470 years – it is viewed by many as an exciting economic prospect. However, its environmental impacts are currently unknown. This is the focus of this paper which estimates for the first time the life cycle impacts of UK shale gas, assuming its use for electricity generation. Shale gas is compared to fossil-fuel alternatives (conventional gas and coal) and low-carbon options (nuclear, offshore wind and solar photovoltaics). The results suggest that the impacts range widely, depending on the assumptions. For example, the global warming potential (GWP100) of electricity from shale gas ranges from 412 to 1102 g CO 2 -eq./kWh with a central estimate of 462 g. The central estimates suggest that shale gas is comparable or superior to conventional gas and low-carbon technologies for depletion of abiotic resources, eutrophication, and freshwater, marine and human toxicities. Conversely, it has a higher potential for creation of photochemical oxidants (smog) and terrestrial toxicity than any other option considered. For acidification, shale gas is a better option than coal power but an order of magnitude worse than the other options. The impact on ozone layer depletion is within the range found for conventional gas, but nuclear and wind power are better options still. The results of this research highlight the need for tight regulation and

Economic competitiveness of small modular reactors versus coal and combined cycle plants

International Nuclear Information System (INIS)

Alonso, Gustavo; Bilbao, Sama; Valle, Edmundo del

2016-01-01

Small modular reactors (SMRs) may be an option to cover the electricity needs of isolated regions, distributed generation grids and countries with small electrical grids. Previous analyses show that the overnight capital cost for SMRs is between 4500 US$/kW and 5350 US$/kW, which is between a 6% and a 26% higher than the average cost of a current large nuclear reactor. This study analyzes the economic competitiveness of small modular reactors against thermal plants using coal and natural gas combined cycle plants. To assess the economic competitiveness of SMRs, three overnight capital costs are considered 4500 US$/kW, 5000 US$/kW and 5350 US$/kW along with three discount rates for each overnight cost considered, these are 3, 7, and 10%. To compare with natural gas combined cycle (CC) units, four different gas prices are considered, these are 4.74 US$/GJ (5 US$/mmBTU), 9.48 US$/GJ (10 US$/mmBTU), 14.22 US$/GJ (15 US$/mmBTU), and 18.96 US$/GJ (20 US$/mmBTU). To compare against coal, two different coal prices are considered 80 and 120 US$/ton of coal. The carbon tax considered, for both CC and coal, is 30 US$/ton CO_2. The results show what scenarios make SMRs competitive against coal and/or combined cycle plants. In addition, because the price of electricity is a key component to guarantee the feasibility of a new project, this analysis calculates the price of electricity for the economically viable deployment of SMRs in all the above scenarios. In particular, this study shows that a minimum price of electricity of 175 US$/MWh is needed to guarantee the feasibility of a new SMR, if its overnight capital cost is 5350 US$/kWe and the discount rate is 10%. Another result is that when the price of electricity is around 100 US$/MWh then the discount rate must be around 7% or less to provide appropriate financial conditions to make SMRs economically feasible. - Highlights: • Small modular reactor (SMR) are economically assessed. • SMR are compared against gas and coal

Thermodynamics of a closed-cycle gas flow system for cooling a HTc dc-SQUID magnetometer

NARCIS (Netherlands)

van den Bosch, P.J.; van den Bosch, P.J.; ter Brake, Hermanus J.M.; van den Eijkel, G.C.; Boelens, J.P.; Holland, Herman J.; Verberne, J.F.C.; Rogalla, Horst

1994-01-01

A multichannel high-Tc dc-SQUID based heart-magnetometer is currently under development in our laboratory. The system is cooled by a cooler that, due to its magnetic interference, has to be separated from the SQUID unit. In the present prototype system a closed-cycle gas flow was chosen as the

Definition of breeding gain for the closed fuel cycle and application to a gas cooled fast reactor

International Nuclear Information System (INIS)

Van Rooijen, W. F. G.; Kloosterman, J. L.; Van Der Hagen, T. H. J. J.; Van Dam, H.

2006-01-01

In this paper a definition is given for the Breeding Gain (BG) of a nuclear reactor, taking into account compositional changes of the fuel during irradiation, cool down and reprocessing. A definition is given for the reactivity weights required to calculate BG. To calculate the effects of changes in the initial fuel composition on BG, first order nuclide perturbation theory is used. The theory is applied to the fuel cycle of GFR600, a 600 MWth Generation IV Gas Cooled Fast Reactor. This reactor should have a closed fuel cycle, with a BG equal to zero, breeding just enough new fuel during irradiation to allow refueling by only adding fertile material. All Heavy Metal is recycled in the closed fuel cycle. The result is that a closed fuel cycle is possible if the reprocessing has low losses ( 238 U, 15% Pu, and low amounts of the Minor Actinides. (authors)

Greenhouse gas emissions from shale gas and coal for electricity generation in South Africa

Directory of Open Access Journals (Sweden)

Brett Cohen

2014-03-01

Full Text Available There is increased interest, both in South Africa and globally, in the use of shale gas for electricity and energy supply. The exploitation of shale gas is, however, not without controversy, because of the reported environmental impacts associated with its extraction. The focus of this article is on the greenhouse gas footprint of shale gas, which some literature suggests may be higher than what would have been expected as a consequence of the contribution of fugitive emissions during extraction, processing and transport. Based on some studies, it has been suggested that life-cycle emissions may be higher than those from coal-fired power. Here we review a number of studies and analyse the data to provide a view of the likely greenhouse gas emissions from producing electricity from shale gas, and compare these emissions to those of coal-fired power in South Africa. Consideration was given to critical assumptions that determine the relative performance of the two sources of feedstock for generating electricity � that is the global warming potential of methane and the extent of fugitive emissions. The present analysis suggests that a 100-year time horizon is appropriate in analysis related to climate change, over which period the relative contribution is lower than for shorter periods. The purpose is to limit temperature increase in the long term and the choice of metric should be appropriate. The analysis indicates that, regardless of the assumptions about fugitive emissions and the period over which global warming potential is assessed, shale gas has lower greenhouse gas emissions per MWh of electricity generated than coal. Depending on various factors, electricity from shale gas would have a specific emissions intensity between 0.3 tCO2/MWh and 0.6 tCO2/MWh, compared with about 1 tCO2/MWh for coal-fired electricity in South Africa.

Release and sorption of alkali metals in coal fired combined cycle power systems; Freisetzung und Einbindung von Alkalimetallverbindungen in kohlebefeuerten Kombikraftwerken

Energy Technology Data Exchange (ETDEWEB)

Mueller, Michael

2009-07-01

Coal fired combined cycle power systems will be a sufficient way to increase the efficiency of coal combustion. However, combined cycle power systems require a reliable hot gas cleanup. Especially alkali metals, such as sodium and potassium, can lead to hot corrosion of the gas turbine blading if they condensate as sulphates. The actual work deals with the release and sorption of alkali metals in coal fired combined cycle power systems. The influence of coal composition, temperature and pressure on the release of alkali species in coal combustion was investigated and the relevant release mechanisms identified. Alumosilicate sorbents have been found that reduce the alkali concentration in the hot flue gas of the Circulating Pressurized Fluidized Bed Combustion 2{sup nd} Generation (CPFBC 2{sup nd} Gen.) at 750 C to values sufficient for use in a gas turbine. Accordingly, alumosilicate sorbents working at 1400 C have been found for the Pressurized Pulverized Coal Combustion (PPCC). The sorption mechanisms have been identified. Thermodynamic calculations were performed to upscale the results of the laboratory experiments to conditions prevailing in power systems. According to these calculations, there is no risk of hot corrosion in both processes. Furthermore, thermodynamic calculations were performed to investigate the behaviour of alkali metals in an IGCC with integrated hot gas cleanup and H{sub 2} membrane for CO{sub 2} sequestration. (orig.)

The long-term life cycle private and external costs of high coal usage in the US

International Nuclear Information System (INIS)

Bergerson, Joule; Lave, Lester

2007-01-01

Using four times as much coal in 2050 for electricity production need not degrade air quality or increase greenhouse gas emissions. Current SO x and NO x emissions from the power sector could be reduced from 12 to less than 1 and from 5 to 2 million tons annually, respectively, using advanced technology. While direct CO 2 emissions from new power plants could be reduced by over 87%, life cycle emissions could increase by over 25% due to the additional coal that is required to be mined and transported to compensate for the energy penalty of the carbon capture and storage technology. Strict environmental controls push capital costs of pulverized coal (PC) and integrated coal gasification combined cycle (IGCC) plants to $1500-1700/kW and $1600-2000/kW, respectively. Adding carbon capture and storage (CCS) increases costs to $2400-2700/kW and $2100-3000/kW (2005 dollars), respectively. Adding CCS reduces the 40-43% efficiency of the ultra-supercritical PC plant to 31-34%; adding CCS reduces the 32-38% efficiency of the GE IGCC plant to 27-33%. For IGCC, PC, and natural gas combined cycle (NGCC) plants, the carbon dioxide tax would have to be $53, $74, and $61, respectively, to make electricity from a plant with CCS cheaper. Capturing and storing 90% of the CO 2 emissions increases life cycle costs from 5.4 to 11.6 cents/kWh. This analysis shows that 90% CCS removal efficiency, although being a large improvement over current electricity generation emissions, results in life cycle emissions that are large enough that additional effort is required to achieve significant economy-wide reductions in the US for this large increase in electricity generation using either coal or natural gas

The marriage of gas turbines and coal

International Nuclear Information System (INIS)

Bajura, R.A.; Webb, H.A.

1991-01-01

This paper reports on developing gas turbine systems that can use coal or a coal-based fuel ensures that the United States will have cost-effective environmentally sound options for supplying future power generation needs. Power generation systems that marry coal or a coal-based fuel to a gas turbine? Some matchmakers would consider this an unlikely marriage. Historically, most gas turbines have been operated only on premium fuels, primarily natural gas or distillate oil. The perceived problems from using coal or coal-based fuels in turbines are: Erosion and deposition: Coal ash particles in the hot combustion gases passing through the expander turbine could erode or deposit on the turbine blades. Corrosion: Coal combustion will release alkali compounds form the coal ash. Alkali in the hot gases passing through the expander turbine can cause corrosion of high-temperature metallic surfaces. Emissions: coal contains higher levels of ash, fuel-bound sulfur and nitrogen compounds, and trace contaminants than premium fuels. Meeting stringent environmental regulations for particulates, sulfur dioxide (SO 2 ), nitrogen oxides (NO x ), and trace contaminants will be difficult. Economics: Coal-based systems are expensive to build. The difference in price between coal and premium fuels must be large enough to justify the higher capital cost

Improvement in recuperative gas cycles by means of a heat generator partly by-passing the recuperator. Application to open and closed cycles and to various kinds of energy

International Nuclear Information System (INIS)

Tilliette, Z.P.; Pierre, B.

1979-01-01

A particular arrangement applicable to open or closed recuperative gas cycles and consisting of a heat generator partly by-passing the low pressure side of the recuperator is proven to enhance advantages of gas cycles for energy production. The cogeneration of both power with a high efficiency owing to the recuperator and high temperature process heat becomes possible and economically attractive. Furthermore, additional possibilities appear for power generation by combined gas and steam or ammonia cycles. In any case the overall utilization coefficient of the primary energy is increased and the combined production of low or medium temperature heat can also be improved. The great operation flexibility of the system for combined energy generation is worth being emphasized: the by-pass arrangement involves no significant change in the operation conditions of the main turbocompressor as the heat output varies. Applications of this arrangement are made to: - open and closed gas cycle, power plants; - fossil, nuclear and solar energies. The overall heat conversion efficiency is tentatively estimated in order to appreciate the energy conversion capability of the investigated power plants

Potential efficiencies of open- and closed-cycle CO, supersonic, electric-discharge lasers

Science.gov (United States)

Monson, D. J.

1976-01-01

Computed open- and closed-cycle system efficiencies (laser power output divided by electrical power input) are presented for a CW carbon monoxide, supersonic, electric-discharge laser. Closed-system results include the compressor power required to overcome stagnation pressure losses due to supersonic heat addition and a supersonic diffuser. The paper shows the effect on the system efficiencies of varying several important parameters. These parameters include: gas mixture, gas temperature, gas total temperature, gas density, total discharge energy loading, discharge efficiency, saturated gain coefficient, optical cavity size and location with respect to the discharge, and supersonic diffuser efficiency. Maximum open-cycle efficiency of 80-90% is predicted; the best closed-cycle result is 60-70%.

Combined Heat and Power: Coal-Fired Air Turbine (CAT)-Cycle Plant

International Nuclear Information System (INIS)

Lee Recca

1999-01-01

By combining an integrated system with a gas turbine, coal-fired air turbine cycle technology can produce energy at an efficiency rate of over 40%, with capital and operating costs below those of competing conventional systems. Read this fact sheet to discover the additional benefits of this exciting new technology

Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 5: Combined gas-steam turbine cycles. [energy conversion efficiency in electric power plants

Science.gov (United States)

Amos, D. J.; Foster-Pegg, R. W.; Lee, R. M.

1976-01-01

The energy conversion efficiency of gas-steam turbine cycles was investigated for selected combined cycle power plants. Results indicate that it is possible for combined cycle gas-steam turbine power plants to have efficiencies several point higher than conventional steam plants. Induction of low pressure steam into the steam turbine is shown to improve the plant efficiency. Post firing of the boiler of a high temperature combined cycle plant is found to increase net power but to worsen efficiency. A gas turbine pressure ratio of 12 to 1 was found to be close to optimum at all gas turbine inlet temperatures that were studied. The coal using combined cycle plant with an integrated low-Btu gasifier was calculated to have a plant efficiency of 43.6%, a capitalization of $497/kW, and a cost of electricity of 6.75 mills/MJ (24.3 mills/kwh). This combined cycle plant should be considered for base load power generation.

Closed Cycle Engine Program Used in Solar Dynamic Power Testing Effort

Science.gov (United States)

Ensworth, Clint B., III; McKissock, David B.

1998-01-01

NASA Lewis Research Center is testing the world's first integrated solar dynamic power system in a simulated space environment. This system converts solar thermal energy into electrical energy by using a closed-cycle gas turbine and alternator. A NASA-developed analysis code called the Closed Cycle Engine Program (CCEP) has been used for both pretest predictions and post-test analysis of system performance. The solar dynamic power system has a reflective concentrator that focuses solar thermal energy into a cavity receiver. The receiver is a heat exchanger that transfers the thermal power to a working fluid, an inert gas mixture of helium and xenon. The receiver also uses a phase-change material to store the thermal energy so that the system can continue producing power when there is no solar input power, such as when an Earth-orbiting satellite is in eclipse. The system uses a recuperated closed Brayton cycle to convert thermal power to mechanical power. Heated gas from the receiver expands through a turbine that turns an alternator and a compressor. The system also includes a gas cooler and a radiator, which reject waste cycle heat, and a recuperator, a gas-to-gas heat exchanger that improves cycle efficiency by recovering thermal energy.

Gas associated to coal in Colombia. An energetic alternative of non-conventional gas fields

International Nuclear Information System (INIS)

Garcia Gonzalez, Mario

2005-01-01

Colombia possesses the biggest coal reserves of Latin America, in such a way that the potential reserves of Gas Associated to the Coal (GAC) they are of great magnitude; the paper includes topics like the generation of the gas associated to the coal, geologic factors that control the gas occurrence, development of the gas associated to the coal in the world, and potential reserves of gas associated to the coal in Colombia

Coal-based synthetic natural gas (SNG): A solution to China’s energy security and CO2 reduction?

International Nuclear Information System (INIS)

Ding, Yanjun; Han, Weijian; Chai, Qinhu; Yang, Shuhong; Shen, Wei

2013-01-01

Considering natural gas (NG) to be the most promising low-carbon option for the energy industry, large state owned companies in China have established numerous coal-based synthetic natural gas (SNG) projects. The objective of this paper is to use a system approach to evaluate coal-derived SNG in terms of life-cycle energy efficiency and CO 2 emissions. This project examined main applications of the SNG and developed a model that can be used for evaluating energy efficiency and CO 2 emissions of various fuel pathway systems. The model development started with the GREET model, and added the SNG module and an end-use equipment module. The database was constructed with Chinese data. The analyses show when the SNG are used for cooking, power generation, steam production for heating and industry, life-cycle energies are 20–108% higher than all competitive pathways, with a similar rate of increase in life-cycle CO 2 emissions. When a compressed natural gas (CNG) car uses the SNG, life-cycle CO 2 emission will increase by 150–190% compared to the baseline gasoline car and by 140–210% compared to an electric car powered by electricity from coal-fired power plants. The life-cycle CO 2 emission of SNG-powered city bus will be 220–270% higher than that of traditional diesel city bus. The gap between SNG-powered buses and new hybrid diesel buses will be even larger—life-cycle CO 2 emission of the former being around 4 times of that of the latter. It is concluded that the SNG will not accomplish the tasks of both energy conservation and CO 2 reduction. - Highlights: ► We evaluated life-cycle energy efficiency and CO 2 emissions of coal-derived SNG. ► We used GREET model and added a coal-based SNG and an end-use modules. ► The database was constructed with Chinese domestic data. ► Life-cycle energies and CO 2 emissions of coal-based SNG are 20–100% higher. ► Coal-based SNG is not a solution to both energy conservation and CO 2 reduction

Closed cycle MHD specialist meeting. Progress report, 1971--1972

International Nuclear Information System (INIS)

Rietjens, L.H.

1972-04-01

Abstracts of the conference papers on closed cycle MHD research are presented. The general areas of discussion are the following: results on closed cycle experiments; plasma properties, and instabilities and stabilization in nonequilibrium plasmas; loss mechanisms, current distributions, electrode effects, boundary layers, and gas dynamic effects; and design concepts of large MHD generators, and nuclear MHD power plants. (GRA)

Effects of Loading Rate on Gas Seepage and Temperature in Coal and Its Potential for Coal-Gas Disaster Early-Warning

Directory of Open Access Journals (Sweden)

Chong Zhang

2017-08-01

Full Text Available The seepage velocity and temperature externally manifest the changing structure, gas desorption and energy release that occurs in coal containing gas failure under loading. By using the system of coal containing gas failure under loading, this paper studies the law of seepage velocity and temperature under different loading rates and at 1.0 MPa confining pressure and 0.5 MPa gas pressure, and combined the on-site results of gas pressure and temperature. The results show that the stress directly affects the seepage velocity and temperature of coal containing gas, and the pressure and content of gas have the most sensitivity to mining stress. Although the temperature is not sensitive to mining stress, it has great correlation with mining stress. Seepage velocity has the characteristic of critically slowing down under loading. This is demonstrated by the variance increasing before the main failure of the samples. Therefore, the variance of seepage velocity with time and temperature can provide an early warning for coal containing gas failing and gas disasters in a coal mine.

Model of environmental life cycle assessment for coal mining operations.

Science.gov (United States)

Burchart-Korol, Dorota; Fugiel, Agata; Czaplicka-Kolarz, Krystyna; Turek, Marian

2016-08-15

This paper presents a novel approach to environmental assessment of coal mining operations, which enables assessment of the factors that are both directly and indirectly affecting the environment and are associated with the production of raw materials and energy used in processes. The primary novelty of the paper is the development of a computational environmental life cycle assessment (LCA) model for coal mining operations and the application of the model for coal mining operations in Poland. The LCA model enables the assessment of environmental indicators for all identified unit processes in hard coal mines with the life cycle approach. The proposed model enables the assessment of greenhouse gas emissions (GHGs) based on the IPCC method and the assessment of damage categories, such as human health, ecosystems and resources based on the ReCiPe method. The model enables the assessment of GHGs for hard coal mining operations in three time frames: 20, 100 and 500years. The model was used to evaluate the coal mines in Poland. It was demonstrated that the largest environmental impacts in damage categories were associated with the use of fossil fuels, methane emissions and the use of electricity, processing of wastes, heat, and steel supports. It was concluded that an environmental assessment of coal mining operations, apart from direct influence from processing waste, methane emissions and drainage water, should include the use of electricity, heat and steel, particularly for steel supports. Because the model allows the comparison of environmental impact assessment for various unit processes, it can be used for all hard coal mines, not only in Poland but also in the world. This development is an important step forward in the study of the impacts of fossil fuels on the environment with the potential to mitigate the impact of the coal industry on the environment. Copyright © 2016 Elsevier B.V. All rights reserved.

Assessment of fuel-cycle energy use and greenhouse gas emissions for Fischer-Tropsch diesel from coal and cellulosic biomass

International Nuclear Information System (INIS)

Xie, X.; Wang, M.; Han, J.

2011-01-01

This study expands and uses the GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) model to assess the effects of carbon capture and storage (CCS) technology and cellulosic biomass and coal cofeeding in Fischer-Tropsch (FT) plants on energy use and greenhouse gas (GHG) emissions of FT diesel (FTD). To demonstrate the influence of the coproduct credit methods on FTD life-cycle analysis (LCA) results, two allocation methods based on the energy value and the market revenue of different products and a hybrid method are employed. With the energy-based allocation method, fossil energy use of FTD is less than that of petroleum diesel, and GHG emissions of FTD could be close to zero or even less than zero with CCS when forest residue accounts for 55% or more of the total dry mass input to FTD plants. Without CCS, GHG emissions are reduced to a level equivalent to that from petroleum diesel plants when forest residue accounts for 61% of the total dry mass input. Moreover, we show that coproduct method selection is crucial for LCA results of FTD when a large amount of coproducts is produced.

Structural comparison of hazardous and non-hazardous coals based on gas sorption experiments

Energy Technology Data Exchange (ETDEWEB)

Lakatos, J.; Toth, J. [Research Lab. for Mining Chemistry, Hungarian Academy of Sciences, Miskolc-Egyetemvaros (Hungary); Radnai-Gyoengyoes, Z. [Geopard Ltd., Pecs (Hungary); Bokanyi, L. [Miskolc Univ., Miskolc-Egyetemvaros (Hungary). Dept. of Process Engineering

1997-12-31

Comparison of carbon-dioxide and propane sorption at ambient temperature was used for characterising the difference of the structure of hazardous and non hazardous coals. However, hazardous coals were found more microporous or contain more closed pores than non hazardous ones, this difference couldn`t have been enlarged and attributed to one petrographic component by producing the density fractions. Gas sorption isobars (nitrogen, methane, ethane) are proposed to make a distinction between fine pore structure of coals. (orig.)

Potential performance improvement using a reacting gas (nitrogin tetroxide) as the working fluid in a closed Brayton cycle

Science.gov (United States)

Stochl, R. J.

1979-01-01

The results of an analysis to estimate the performance that could be obtained by using a chemically reacting gas (nitrogen tetroxide) as the working fluid in a closed Brayton cycle are presented. Compared with data for helium as the working fluid, these results indicate efficiency improvements from 4 to 90 percent, depending on turbine inlet temperature, pressures, and gas residence time in heat transfer equipment.

Externality costs of the coal-fuel cycle: The case of Kusile Power Station

Directory of Open Access Journals (Sweden)

Nonophile P. Nkambule

2017-09-01

Full Text Available Coal-based electricity is an integral part of daily life in South Africa and globally. However, the use of coal for electricity generation carries a heavy cost for social and ecological systems that goes far beyond the price we pay for electricity. We developed a model based on a system dynamics approach for understanding the measurable and quantifiable coal-fuel cycle burdens and externality costs, over the lifespan of a supercritical coal-fired power station that is fitted with a flue-gas desulfurisation device (i.e. Kusile Power Station. The total coal-fuel cycle externality cost on both the environment and humans over Kusile's lifespan was estimated at ZAR1 449.9 billion to ZAR3 279 billion or 91c/kWh to 205c/kWh sent out (baseline: ZAR2 172.7 billion or 136c/kWh. Accounting for the life-cycle burdens and damages of coal-derived electricity conservatively, doubles to quadruples the price of electricity, making renewable energy sources such as wind and solar attractive alternatives. Significance: The use of coal for electricity generation carries a heavy cost for social and ecological systems that goes far beyond the price we pay for electricity. The estimation of social costs is particularly important to the electric sector because of non-differentiation of electricity prices produced from a variety of sources with potentially very dissimilar environmental and human health costs. Because all electricity generation technologies are associated with undesirable side effects in their fuelcycle and lifespan, comprehensive comparative analyses of life-cycle costs of all power generation technologies is indispensable to guide the development of future energy policies in South Africa.

Gas and coal competition in the EU Power Sector

International Nuclear Information System (INIS)

Cornot-Gandolphe, Sylvie

2014-06-01

Despite its many assets, a confluence of factors - including flat electricity demand, rising use of renewable energy sources, falling wholesale electricity market prices, high gas prices relative to coal and low CO 2 prices - has eroded the competitiveness of natural gas in the EU power sector. The share of natural gas in the EU electricity mix has decreased from 23% in 2010 to 20.5% in 2012. By contrast, coal-fired power stations have been operating at high loads, increasing coal demand by the sector. This thorough analysis by CEDIGAZ of gas, coal and CO 2 dynamics in the context of rising renewables is indispensable to understand what is at stake in the EU power sector and how it will affect future European gas demand. Main findings of the report: - Coal is likely to retain its cost advantage into the coming decade: The relationship between coal, gas and CO 2 prices is a key determinant of the competition between gas and coal in the power sector and will remain the main driver of fuel switching. A supply glut on the international coal market (partly because of an inflow of US coal displaced by shale gas) has led to a sharp decline in coal prices while gas prices, still linked to oil prices to a significant degree, have increased by 42% since 2010. At the same time, CO 2 prices have collapsed, reinforcing coal competitiveness. Our analysis of future trends in coal, gas and CO 2 prices suggests that coal competitive advantage may well persist into the coming decade. - But coal renaissance may still be short-lived: Regulations on emissions of local pollutants, i.e. the Large Plant Combustion Directive (LCPD) and the Industrial Emissions Directive (IED) that will succeed it in 2016, will lead to the retirement of old, inefficient coal-fired power plants. Moreover, the rapid development of renewables, which so far had only impacted gas-fired power plants is starting to take its toll on hard coal plants' profitability. This trend is reinforced by regulation at EU or

Assessment of greenhouse gas emissions from natural gas

International Nuclear Information System (INIS)

Anon

2000-01-01

The study, 'Assesment of greenhouse gas emission from natural gas' by independent consultants Energetics Pty Ltd, shows that natural gas has significantly fewer greenhouses gas emissions than either black or brown cola for the defined life cycle stages. The life cycle emissions from natural gas use by an Australian Major User are approximately 50% less than the emissions from Victorian brown coal and approximately 38% less than the emissions from Australian average black coal. Australian Best Practice gas fired electricity generation is estimated to emit between 514 and 658 kg CO 2 e/MWh. By comparison, Australian Best Practice coal-fired electricity generation is estimated to emit between 907 and 1,246 kg CO 2 e/MWh for black and brown coal respectively. Greenhouse gas emissions from Australian Best Practice gas-fired electricity generation using combined cycle gas turbines (including full fuel cycle emissions) vary from 41% to 46% of the emissions from brown coal-fired electricity generation and 57% to 64% of emissions from black coal-fired electricity generation. Greenhouse gas emissions from direct gas supply water heating range from 1,470 to 2,042 kilograms per annum. This compares with emissions of 1,922 to 2,499 kg for electric heating from gas-fired electricity generation and 3,975 to 5,393 kg for coal-fired electricity generation. The implications for greenhouse policy nationally are also discussed, emphasising the need to review national energy policy, currently tied to 'fuel neutrality' doctrine

Competition between coal and gas for large scale power generation

International Nuclear Information System (INIS)

Howieson, B.

1997-01-01

The relative competitiveness of coal- and gas-fired generation will be affected by distinctive country and market factors as well as site specific considerations, regarding such factors as environment, market structure and economics (such as fuel and plant costs). National and international politics have an impact on all three factors and any decision on the development of generation plant must take into account both current and future political climates. An analysis suggests that, at the present time, upgrading existing coal stations is attractive compared with new combined cycle gas turbines (CCGTs). However, this conclusion is highly dependent on the site specific nature of existing plant and the anticipated future environmental regime. Increased environmental pressure, particularly in the area of CO 2 emissions, would result in CCGTs being the first choice plant option. (R.P.)

Clean coal technologies

International Nuclear Information System (INIS)

Aslanyan, G.S.

1993-01-01

According to the World Energy Council (WEC), at the beginning of the next century three main energy sources - coal, nuclear power and oil will have equal share in the world's total energy supply. This forecast is also valid for the USSR which possesses more than 40% of the world's coal resources and continuously increases its coal production (more than 700 million tons of coal are processed annually in the USSR). The stringent environmental regulations, coupled with the tendency to increase the use of coal are the reasons for developing different concepts for clean coal utilization. In this paper, the potential efficiency and environmental performance of different clean coal production cycles are considered, including technologies for coal clean-up at the pre-combustion stage, advanced clean combustion methods and flue gas cleaning systems. Integrated systems, such as combined gas-steam cycle and the pressurized fluidized bed boiler combined cycle, are also discussed. The Soviet National R and D program is studying new methods for coal utilization with high environmental performance. In this context, some basic research activities in the field of clean coal technology in the USSR are considered. Development of an efficient vortex combustor, a pressurized fluidized bed gasifier, advanced gas cleaning methods based on E-beam irradiation and plasma discharge, as well as new catalytic system, are are presented. In addition, implementation of technological innovations for retrofitting and re powering of existing power plants is discussed. (author)

Clean coal and heavy oil technologies for gas turbines

Energy Technology Data Exchange (ETDEWEB)

Todd, D.M. [GE Industrial & Power Systems, Schenectady, NY (United States)

1994-12-31

Global power generation markets have shown a steady penetration of GT/CC technology into oil and gas fired applications as the technology has matured. The lower cost, improved reliability and efficiency advantages of combined cycles can now be used to improve the cost of electricity and environmental acceptance of poor quality fuels such as coal, heavy oil, petroleum coke and waste products. Four different technologies have been proposed, including slagging combustors, Pressurized Fluidized Bed Combustion (PFBC), Externally Fired Combined Cycle (EFCC) and Integrated Gasification Combined Cycle (IGCC). Details of the technology for the three experimental technologies can be found in the appendix. IGCC is now a commercial technology. In the global marketplace, this shift is being demonstrated using various gasification technologies to produce a clean fuel for the combined cycle. Early plants in the 1980s demonstrated the technical/environmental features and suitability for power generation plants. Economics, however, were disappointing until the model F GT technologies were first used commercially in 1990. The economic break-through of matching F technology gas turbines with gasification was not apparent until 1993 when a number of projects were ordered for commercial operation in the mid-1990s. GE has started 10 new projects for operation before the year 2000. These applications utilize seven different gasification technologies to meet specific application needs. Early plants are utilizing low-cost fuels, such as heavy oil or petroleum coke, to provide economics in first-of-a-kind plants. Some special funding incentives have broadened the applications to include power-only coal plants. Next generation gas turbines projected for commercial applications after the year 2000 will contribute to another step change in technology. It is expected that the initial commercialization process will provide the basis for clear technology choices on future plants.

Life cycle energy use and GHG emission assessment of coal-based SNG and power cogeneration technology in China

International Nuclear Information System (INIS)

Li, Sheng; Gao, Lin; Jin, Hongguang

2016-01-01

Highlights: • Life cycle energy use and GHG emissions are assessed for SNG and power cogeneration. • A model based on a Chinese domestic database is developed for evaluation. • Cogeneration shows lower GHG emissions than coal-power pathway. • Cogeneration has lower life cycle energy use than supercritical coal-power pathway. • Cogeneration is a good option to implement China’s clean coal technologies. - Abstract: Life cycle energy use and GHG emissions are assessed for coal-based synthetic natural gas (SNG) and power cogeneration/polygenereation (PG) technology and its competitive alternatives. Four main SNG applications are considered, including electricity generation, steam production, SNG vehicle and battery electric vehicle (BEV). Analyses show that if SNG is produced from a single product plant, the lower limits of its life cycle energy use and GHG emissions can be comparable to the average levels of coal-power and coal-BEV pathways, but are still higher than supercritical and ultra supercritical (USC) coal-power and coal-BEV pathways. If SNG is coproduced from a PG plant, when it is used for power generation, steam production, and driving BEV car, the life cycle energy uses for PG based pathways are typically lower than supercritical coal-power pathways, but are still 1.6–2.4% higher than USC coal-power pathways, and the average life cycle GHG emissions are lower than those of all coal-power pathways including USC units. If SNG is used to drive vehicle car, the life cycle energy use and GHG emissions of PG-SNGV-power pathway are both much higher than all combined coal-BEV and coal-power pathways, due to much higher energy consumption in a SNG driven car than in a BEV car. The coal-based SNG and power cogeneration technology shows comparable or better energy and environmental performances when compared to other coal-based alternatives, and is a good option to implement China’s clean coal technologies.

Analysis of oxy-fuel combustion power cycle utilizing a pressurized coal combustor

OpenAIRE

Gazzino, Marco; Hong, Jongsup; Chaudhry, Gunaranjan; Brisson II, John G; Field, Randall; Ghoniem, Ahmed F

2009-01-01

Growing concerns over greenhouse gas emissions have driven extensive research into new power generation cycles that enable carbon dioxide capture and sequestration. In this regard, oxy-fuel combustion is a promising new technology in which fuels are burned in an environment of oxygen and recycled combustion gases. In this paper, an oxy-fuel combustion power cycle that utilizes a pressurized coal combustor is analyzed. We show that this approach recovers more thermal energy from the flue gases...

Estimating Externalities of Coal Fuel Cycles, Report 3

Energy Technology Data Exchange (ETDEWEB)

Barnthouse, L.W.; Cada, G.F.; Cheng, M.-D.; Easterly, C.E.; Kroodsma, R.L.; Lee, R.; Shriner, D.S.; Tolbert, V.R.; Turner, R.S.

1994-09-01

The agreement between the US DOE and the EC established the specific objectives of the study: (a) to develop a methodological framework that uses existing data and models to quantify the external costs and benefits of energy; (b) to demonstrate the application of the framework to estimate the externalities of the coal, biomass, oil, natural gas, hydro, nuclear, photovoltaic, and wind fuel cycles (by agreement with the EC, the US addressed the first six of these); and (c) to identify major gaps in the availability of information to quantify impacts, damages, benefits, and externalities of fuel cycles; and to suggest priorities for future research. The main consideration in defining these objectives was a desire to have more information about externalities, and a better method for estimating them.

Exploitation and use of coal field gas

Energy Technology Data Exchange (ETDEWEB)

Wang, K; Li, Z; Sun, Q

1982-04-25

There are slightly more than 440 mine shafts in the world from which gas is pumped at the same time coal is being mined, the volume pumped being 3.125 billion cubic meters. All the countries of the world today widely use gas as a fuel and as a raw material for the chemical industry. In China 40 percent of the total number of mine shafts are high gas mine shafts. In China, gas is used largely as fuel by the people, to fire boilers, to make formaldehyde, and to make carbon ink. Prospects are good for the exploitation of mine shaft gas that is produced in association with coal. Mine shaft gas is a top quality energy source with an extraction life that is longer than coals. (DP)

Life Cycle Greenhouse Gas Analysis of Multiple Vehicle Fuel Pathways in China

Directory of Open Access Journals (Sweden)

Tianduo Peng

2017-11-01

Full Text Available The Tsinghua University Life Cycle Analysis Model (TLCAM is applied to calculate the life cycle fossil energy consumption and greenhouse gas (GHG emissions for more than 20 vehicle fuel pathways in China. In addition to conventional gasoline and diesel, these include coal- and gas-based vehicle fuels, and electric vehicle (EV pathways. The results indicate the following. (1 China’s current dependence on coal and relative low-efficiency processes limits the potential for most alternative fuel pathways to decrease energy consumption and emissions; (2 Future low-carbon electricity pathways offer more obvious advantages, with coal-based pathways needing to adopt carbon dioxide capture and storage technology to compete; (3 A well-to-wheels analysis of the fossil energy consumption of vehicles fueled by compressed natural gas and liquefied natural gas (LNG showed that they are comparable to conventional gasoline vehicles. However, importing rather than domestically producing LNG for vehicle use can decrease domestic GHG emissions by 35% and 31% compared with those of conventional gasoline and diesel vehicles, respectively; (4 The manufacturing and recovery of battery and vehicle in the EV analysis has significant impact on the overall ability of EVs to decrease fossil energy consumption and GHG emissions from ICEVs.

KINETICS OF DIRECT OXIDATION OF H2S IN COAL GAS TO ELEMENTAL SULFUR; F

International Nuclear Information System (INIS)

K.C. Kwon

2002-01-01

Removal of hydrogen sulfide (H(sub 2)S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced Vision 21 plants that employ coal and natural gas and produce electric power and clean transportation fuels. These Vision 21 plants will require highly clean coal gas with H(sub 2)S below 1 ppm and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation Vision 21 plants. To this end, a novel process is now under development at Research Triangle Institute (RTI) in which the H(sub 2)S in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H(sub 2)S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The objective of this research is to support the near- and long-term DOE efforts to commercialize this direct oxidation technology. Specifically, we aim to: Measure the kinetics of direct oxidation of H(sub 2)S to elemental sulfur over selective catalysts in the presence of major

Study for recovery and utilization of coal mine gas in Russia (Kuznetsk coal basin)

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

For the purpose of reducing greenhouse effect gas emissions in line with the Joint Implementation, a study was conducted on recovery/utilization of methane gas emitted from the Chertinskaya coal mine in the Kuznetsk coal basin area. According to the survey, the methane gas emitted from the Chertinskaya coal mine into the atmospheric air is 26 million to 36 million tons on the levels of the annual coal production between 0.7 million and 1 million tons. However, the monthly gas recovery amount and concentration largely fluctuate, and therefore, the use method to cope with this was studied. The study was now under way, and the electric power production using gas engine was regarded as the best. In this project, only the Chertinskaya mine can generate power of 34,721 MWh. In the whole Kuznetsk coal basin, approximately 200 million m{sup 3} of gas is needed to be removed for safety of the mine. The use of this will probably bring energy substitution of about 128,000 tons/year and CO2 reduction of 2.8 million tons/year. (NEDO)

Impacts of Coal Seam Gas (Coal Bed Methane) Extraction on Water Resources in Australia

Science.gov (United States)

Post, David

2017-04-01

While extraction of methane from shale gas deposits has been the principal source of the recent expansion of the industry in the United States, in Australia extraction of methane from coal bed methane deposits (termed 'coal seam gas' in Australia) has been the focus to date. The two sources of methane share many of the same characteristics including the potential requirement for hydraulic fracturing. However, as coal seam gas deposits generally occur at shallower depths than shale gas, the potential impacts of extraction on surface and groundwater resources may be of even greater concern. In Australia, an Independent Expert Scientific Committee (IESC) has been established to provide scientific advice to federal and state government regulators on the impact that coal seam gas and large coal mining developments may have on water resources. This advice is provided to enable decisions to be informed by the best available science about the potential water-related impacts associated with these developments. To support this advice, the Australian Government Department of the Environment has implemented a programme of research termed 'bioregional assessments' to investigate these potential impacts. A bioregional assessment is defined as a scientific analysis of the ecology, hydrology, geology and hydrogeology of a bioregion with explicit assessment of the potential direct, indirect and cumulative impacts of coal seam gas and large coal mining development on water resources. These bioregional assessments are currently being carried out across large portions of eastern Australia underlain by coal reserves. Further details of the programme and results to date can be found at http://www.bioregionalassessments.gov.au. The bioregional assessment programme has modelled the impacts of coal seam gas development on surface and groundwater resources in three regions of eastern Australia, namely the Clarence-Moreton, Gloucester, and Namoi regions. This presentation will discuss the

Permeability changes in coal resulting from gas desorption

Energy Technology Data Exchange (ETDEWEB)

Levine, J.R.; Johnson, P.W.

1992-11-30

This report documents studies on the effects of gas sorption on coal, with the intent of eventually evaluating how sorption and strain affect permeability. These studies were, carried out at the University of Alabama during the period from 1989 through 1992. Two major experimental methods were developed and used. In the strain experiments, electronic strain gauges were attached to polished blocks of coal in order to measure linear and volumetric swelling due to gas sorption. The effects of bedding plane orientation, of gas type, and of coal type were investigated. In the gravimetric experiment the weight of small samples of coal was measured during exposure to high pressure gases. Sample measurements were corrected for buoyancy effects and for sample swelling, and the results were plotted in the form of Langmuir isotherms. Experiments were conducted to determine the effect of grain size, coal type, moisture, and of sorbant gas. The advantage of this method is that it can be applied to very small samples, and it enabled comparison liptinite versus vitrinite concentrates, and kerogen rich versus kerogen depleted oil shales. Also included is a detailed discussion of the makeup of coal and its effect on gas sorption behavior.

Action of coal gas on plants. II. Action on green plants

Energy Technology Data Exchange (ETDEWEB)

Wehmer, C

1917-01-01

Experiments were performed to determine the effects of coal gas on cress. Although the seeds are not killed by coal gas, they are prevented from germinating. Cress will grow in as much as 30% coal gas, but it will not survive higher concentrations. Coal gas contains both toxic and non-toxic constituents. CO, C/sub 2/H/sub 4/, C/sub 2/H/sub 2/, CS/sub 2/, H/sub 2/S are not toxic at concentrations found in coal gas. The toxic effects of coal gas are not caused by the lack of O/sub 2/, but by minor impurities in the gas.

Combined cycles and cogeneration with natural gas and alternative fuels

International Nuclear Information System (INIS)

Gusso, R.

1992-01-01

Since 1985 there has been a sharp increase world-wide in the sales of gas turbines. The main reasons for this are: the improved designs allowing better gas turbine and, thus, combined cycle efficiencies; the good fuel use indices in the the case of cogeneration; the versatility of the gas turbines even with poly-fuel plants; greatly limited exhaust emissions; and lower manufacturing costs and delivery times with respect to conventional plants. This paper after a brief discussion on the evolution in gas turbine applications in the world and in Italy, assesses their use and environmental impacts with fuels other than natural gas. The paper then reviews Italian efforts to develop power plants incorporating combined cycles and the gasification of coal, residual, and other low calorific value fuels

Coal comes clean

International Nuclear Information System (INIS)

Minchener, A.

1991-01-01

Coal's status as the dominant fuel for electricity generation is under threat because of concern over the environmental impacts of acid rain and the greenhouse effect. Sulphur dioxide and nitrogen oxides cause acid rain and carbon dioxide is the main greenhouse gas. All are produced when coal is burnt. Governments are therefore tightening the emission limits for fossil-fuel power plants. In the United Kingdom phased reductions of sulphur dioxide and nitrogen oxides emissions are planned. It will be the responsibility of the power generator to take the necessary steps to reduce the emissions. This will be done using a number of technologies which are explained and outlined briefly - flue gas desulfurization, separation of coal into high and low-sulphur coal, direct desulfurization of coal, circulating fluidised bed combustion, integrated-gasification combined cycle systems and topping cycles. All these technologies are aiming at cleaner, more efficient combustion of coal. (UK)

Boiler briquette coal versus raw coal: Part I--Stack gas emissions.

Science.gov (United States)

Ge, S; Bai, Z; Liu, W; Zhu, T; Wang, T; Qing, S; Zhang, J

2001-04-01

Stack gas emissions were characterized for a steam-generating boiler commonly used in China. The boiler was tested when fired with a newly formulated boiler briquette coal (BB-coal) and when fired with conventional raw coal (R-coal). The stack gas emissions were analyzed to determine emission rates and emission factors and to develop chemical source profiles. A dilution source sampling system was used to collect PM on both Teflon membrane filters and quartz fiber filters. The Teflon filters were analyzed gravimetrically for PM10 and PM2.5 mass concentrations and by X-ray fluorescence (XRF) for trace elements. The quartz fiber filters were analyzed for organic carbon (OC) and elemental carbon (EC) using a thermal/optical reflectance technique. Sulfur dioxide was measured using the standard wet chemistry method. Carbon monoxide was measured using an Orsat combustion analyzer. The emission rates of the R-coal combustion (in kg/hr), determined using the measured stack gas concentrations and the stack gas emission rates, were 0.74 for PM10, 0.38 for PM2.5, 20.7 for SO2, and 6.8 for CO, while those of the BB-coal combustion were 0.95 for PM10, 0.30 for PM2.5, 7.5 for SO2, and 5.3 for CO. The fuel-mass-based emission factors (in g/kg) of the R-coal, determined using the emission rates and the fuel burn rates, were 1.68 for PM10, 0.87 for PM2.5, 46.7 for SO2, and 15 for CO, while those of the BB-coal were 2.51 for PM10, 0.79 for PM2.5, 19.9 for SO2, and 14 for CO. The task-based emission factors (in g/ton steam generated) of the R-coal, determined using the fuel-mass-based emission factors and the coal/steam conversion factors, were 0.23 for PM10, 0.12 for PM2.5, 6.4 for SO2, and 2.0 for CO, while those of the BB-coal were 0.30 for PM10, 0.094 for PM2.5, 2.4 for SO2, and 1.7 for CO. PM10 and PM2.5 elemental compositions are also presented for both types of coal tested in the study.

Boiler Briquette Coal versus Raw Coal: Part I-Stack Gas Emissions.

Science.gov (United States)

Ge, Su; Bai, Zhipeng; Liu, Weili; Zhu, Tan; Wang, Tongjian; Qing, Sheng; Zhang, Junfeng

2001-04-01

Stack gas emissions were characterized for a steam-generating boiler commonly used in China. The boiler was tested when fired with a newly formulated boiler briquette coal (BB-coal) and when fired with conventional raw coal (R-coal). The stack gas emissions were analyzed to determine emission rates and emission factors and to develop chemical source profiles. A dilution source sampling system was used to collect PM on both Teflon membrane filters and quartz fiber filters. The Teflon filters were analyzed gravimetrically for PM 10 and PM 2.5 mass concentrations and by X-ray fluorescence (XRF) for trace elements. The quartz fiber filters were analyzed for organic carbon (OC) and elemental carbon (EC) using a thermal/optical reflectance technique. Sulfur dioxide was measured using the standard wet chemistry method. Carbon monoxide was measured using an Orsat combustion analyzer. The emission rates of the R-coal combustion (in kg/hr), determined using the measured stack gas concentrations and the stack gas emission rates, were 0.74 for PM 10 , 0.38 for PM 25 , 20.7 for SO 2 , and 6.8 for CO, while those of the BB-coal combustion were 0.95 for PM 10 , 0.30 for PM 2 5 , 7.5 for SO 2 , and 5.3 for CO. The fuel-mass-based emission factors (in g/kg) of the R-coal, determined using the emission rates and the fuel burn rates, were 1.68 for PM 10 , 0.87 for PM 25 , 46.7 for SO 2 , and 15 for CO, while those of the BB-coal were 2.51 for PM 10 , 0.79 for PM 2.5 , 19.9 for SO 2 , and 14 for CO. The task-based emission factors (in g/ton steam generated) of the R-coal, determined using the fuel-mass-based emission factors and the coal/ steam conversion factors, were 0.23 for PM 10 , 0.12 for PM 2.5 , 6.4 for SO 2 , and 2.0 for CO, while those of the BB-coal were 0.30 for PM 10 , 0.094 for PM 2.5 , 2.4 for SO 2 , and 1.7 for CO. PM 10 and PM 2.5 elemental compositions are also presented for both types of coal tested in the study.

The future development of the British coal topping cycles

International Nuclear Information System (INIS)

Harrison, J.S.; Dawes, S.G.; Minchener, A.J.

1992-01-01

In the United Kingdom (UK), at present most of the electricity produced from coal is generated using large pulverized fuel boilers with a conventional steam cycle. This technology has been developed over many years and has culminated in a 6 x 660 MWe station at Drax. The design cycle efficiency of such a station is some 40%, lower heating value basis, this limit being due to the nature of the Rankin cycle appropriate for steam turbines without utilization of the lower grade heat as in a combined heat and power (CHP) system. This paper reports that there is an increasing concern regarding the potential environmental impact of fossil-fuel fired systems. In particular, emissions limits are being tightened for particulates, NO x SO 2 . There is also concern over the greenhouse gases such as CO 2 . For existing conventional plant, this has resulted in the retrofitting of low NO x burners coupled in some instances with the introduction of flue gas desulphurization (FGD) equipment. Such modifications lead to significant increases in the capital and operating costs, with loss in cycle efficiency when FGD is fitted. Thus at Drax the efficiency will fall by some 1% to below 39%. These adverse effects have increased the need for alternative coal-fired generation systems which will have higher efficiencies while at the same time improving the environmental impact of the power stations. The environmental debate over the use of fossil fuels for power generation will continue, with continuing public uncertainty especially over the extent and causes of enhanced global warming. The debate will continue against a background of rising power generation demand worldwide, particularly in developing countries. What is clear is that in the absence of long-term, cost effective and technologically proven alternatives to fossil fuels, coal will remain the prime fuel for power generation

Connect the Spheres with the Coal Cycle

Science.gov (United States)

Clary, Renee; Wandersee, James

2010-01-01

Coal fueled the Industrial Revolution and, as a result, changed the course of human history. However, the geologic history of coal is much, much longer than that which is recorded by humans. In your classroom, the coal cycle can be used to trace the formation of this important economic resource from its plant origins, through its lithification, or…

Shale gas vs. coal: Policy implications from environmental impact comparisons of shale gas, conventional gas, and coal on air, water, and land in the United States

International Nuclear Information System (INIS)

Jenner, Steffen; Lamadrid, Alberto J.

2013-01-01

The aim of this paper is to examine the major environmental impacts of shale gas, conventional gas and coal on air, water, and land in the United States. These factors decisively affect the quality of life (public health and safety) as well as local and global environmental protection. Comparing various lifecycle assessments, this paper will suggest that a shift from coal to shale gas would benefit public health, the safety of workers, local environmental protection, water consumption, and the land surface. Most likely, shale gas also comes with a smaller GHG footprint than coal. However, shale gas extraction can affect water safety. This paper also discusses related aspects that exemplify how shale gas can be more beneficial in the short and long term. First, there are technical solutions readily available to fix the most crucial problems of shale gas extraction, such as methane leakages and other geo-hazards. Second, shale gas is best equipped to smoothen the transition to an age of renewable energy. Finally, this paper will recommend hybrid policy regulations. - Highlights: ► We examine the impacts of (un)conventional gas and coal on air, water, and land. ► A shift from coal to shale gas would benefit public health. ► Shale gas extraction can affect water safety. ► We discuss technical solutions to fix the most crucial problems of shale gas extraction. ► We recommend hybrid regulations.

Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 9: Closed-cycle MHD. [energy conversion efficiency of electric power plants using magnetohydrodynamics

Science.gov (United States)

Tsu, T. C.

1976-01-01

A closed-cycle MHD system for an electric power plant was studied. It consists of 3 interlocking loops, an external heating loop, a closed-cycle cesium seeded argon nonequilibrium ionization MHD loop, and a steam bottomer. A MHD duct maximum temperature of 2366 K (3800 F), a pressure of 0.939 MPa (9.27 atm) and a Mach number of 0.9 are found to give a topping cycle efficiency of 59.3%; however when combined with an integrated gasifier and optimistic steam bottomer the coal to bus bar efficiency drops to 45.5%. A 1978 K (3100 F) cycle has an efficiency of 55.1% and a power plant efficiency of 42.2%. The high cost of the external heating loop components results in a cost of electricity of 21.41 mills/MJ (77.07 mills/kWh) for the high temperature system and 19.0 mills/MJ (68.5 mills/kWh) for the lower temperature system. It is, therefore, thought that this cycle may be more applicable to internally heated systems such as some futuristic high temperature gas cooled reactor.

Gas to Coal Competition in the U.S. Power Sector

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-06-01

With the newfound availability of natural gas due to the shale gas revolution in the United States, cheap gas now threatens coal’s longstanding position as the least costly fuel for generating electricity. But other factors besides cost come into play when deciding to switch from coal to gas. Electricity and gas transmission grid constraints, regulatory and contractual issues, as well as other factors determine the relative share of coal and gas in power generation. This paper analyzes competition between coal and gas for generating power in the United States and the factors explaining this dynamic. It also projects coal-to-gas switching in power generation for 18 states representing 75% of the surplus gas potential in the United States up to 2017, taking into consideration the impact of environmental legislation on retirement of coal-fired power plants.

Closed power cycles thermodynamic fundamentals and applications

CERN Document Server

Invernizzi, Costante Mario

2013-01-01

With the growing attention to the exploitation of renewable energies and heat recovery from industrial processes, the traditional steam and gas cycles are showing themselves often inadequate. The inadequacy is due to the great assortment of the required sizes power and of the large kind of heat sources. Closed Power Cycles: Thermodynamic Fundamentals and Applications offers an organized discussion about the strong interaction between working fluids, the thermodynamic behavior of the cycle using them and the technological design aspects of the machines. A precise treatment of thermal engines op

Recovery of Rare Earth Elements from Coal and Coal Byproducts via a Closed Loop Leaching Process: Final Report

Energy Technology Data Exchange (ETDEWEB)

Peterson, Richard [Battelle Memorial Inst., Columbus, OH (United States); Heinrichs, Michael [Battelle Memorial Inst., Columbus, OH (United States); Argumedo, Darwin [Battelle Memorial Inst., Columbus, OH (United States); Taha, Rachid [Battelle Memorial Inst., Columbus, OH (United States); Winecki, Slawomir [Battelle Memorial Inst., Columbus, OH (United States); Johnson, Kathryn [Battelle Memorial Inst., Columbus, OH (United States); Lane, Ann [Battelle Memorial Inst., Columbus, OH (United States); Riordan, Daniel [Battelle Memorial Inst., Columbus, OH (United States)

2017-08-31

Objectives: Through this grant, Battelle proposes to address Area of Interest (AOI) 1 to develop a bench-scale technology to economically separate, extract, and concentrate mixed REEs from coal ash. U.S. coal and coal byproducts provide the opportunity for a domestic source of REEs. The DOE’s National Energy Technology Laboratory (NETL) has characterized various coal and coal byproducts samples and has found varying concentrations of REE ranging up to 1,000 parts per million by weight. The primary project objective is to validate the economic viability of recovering REEs from the coal byproduct coal ash using Battelle’s patented closed-loop Acid Digestion Process (ADP). This will be accomplished by selecting coal sources with the potential to provide REE concentrations above 300 parts per million by weight, collecting characterization data for coal ash samples generated via three different methods, and performing a Techno-Economic Analysis (TEA) for the proposed process. The regional availability of REE-laden coal ash, the regional market for rare earth concentrates, and the system capital and operating costs for rare earth recovery using the ADP technology will be accounted for in the TEA. Limited laboratory testing will be conducted to generate the parameters needed for the design of a bench scale system for REE recovery. The ultimate project outcome will be the design for an optimized, closed loop process to economically recovery REEs such that the process may be demonstrated at the bench scale in a Phase 2 project. Project Description: The project will encompass evaluation of the ADP technology for the economic recovery of REEs from coal and coal ash. The ADP was originally designed and demonstrated for the U.S. Army to facilitate demilitarization of cast-cured munitions via acid digestion in a closed-loop process. Proof of concept testing has been conducted on a sample of Ohio-based Middle Kittanning coal and has demonstrated the feasibility of recovering

Analysis of rationality of coal-based synthetic natural gas (SNG) production in China

International Nuclear Information System (INIS)

Li, Hengchong; Yang, Siyu; Zhang, Jun; Kraslawski, Andrzej; Qian, Yu

2014-01-01

To alleviate the problem of the insufficient reserves of natural gas in China, coal-based synthetic natural gas (SNG) is considered to be a promising option as a source of clean energy, especially for urban use. However, recent study showed that SNG will not accomplish the task of simultaneous energy conservation and CO 2 reduction. In this paper, life cycle costing is made for SNG use in three main applications in residential sector: heating, household use, and public transport. Comparisons are conducted between SNG and coal, natural gas, liquefied petroleum gas (LPG), diesel, and methanol. The results show that SNG is a competitive option only for household use. The use of SNG for heating boilers or city buses is not as cost-effective as expected. The biggest shortcoming of SNG is the large amount of pollutants generated in the production stage. At the moment, the use of SNG is promoted by the government. However, as shown in this paper, one can expect a transfer of pollution from the urban areas to the regions where SNG is produced. Therefore, it is suggested that well-balanced set of environmental damage-compensating policies should be introduced to compensate the environmental losses in the SNG-producing regions. - Highlights: • Life cycle costing was applied on the coal-based SNG. • The SNG was compared with conventional fuels of three residential applications. • The SNG is not so cost-effective except of household use. • Ecological compensation policy is useful to deal with the transfer of pollutions

Analysis of oxy-fuel combustion power cycle utilizing a pressurized coal combustor

International Nuclear Information System (INIS)

Hong, Jongsup; Chaudhry, Gunaranjan; Brisson, J.G.; Field, Randall; Gazzino, Marco; Ghoniem, Ahmed F.

2009-01-01

Growing concerns over greenhouse gas emissions have driven extensive research into new power generation cycles that enable carbon dioxide capture and sequestration. In this regard, oxy-fuel combustion is a promising new technology in which fuels are burned in an environment of oxygen and recycled combustion gases. In this paper, an oxy-fuel combustion power cycle that utilizes a pressurized coal combustor is analyzed. We show that this approach recovers more thermal energy from the flue gases because the elevated flue gas pressure raises the dew point and the available latent enthalpy in the flue gases. The high-pressure water-condensing flue gas thermal energy recovery system reduces steam bleeding which is typically used in conventional steam cycles and enables the cycle to achieve higher efficiency. The pressurized combustion process provides the purification and compression unit with a concentrated carbon dioxide stream. For the purpose of our analysis, a flue gas purification and compression process including de-SO x , de-NO x , and low temperature flash unit is examined. We compare a case in which the combustor operates at 1.1 bars with a base case in which the combustor operates at 10 bars. Results show nearly 3% point increase in the net efficiency for the latter case.

Greenhouse gas emission from Australian coal mining

International Nuclear Information System (INIS)

Williams, D.

1998-01-01

Since 1997, when the Australian Coal Association (ACA) signed a letter of Intent in respect of the governments Greenhouse Challenge Program, it has encouraged its member companies to participate. Earlier this year, the ACA commissioned an independent scoping study on greenhouse gas emissions in the black coal mining industry This was to provide background information, including identification of information gaps and R and D needs, to guide the formulation of a strategy for the mitigation of greenhouse gas emissions associated with the mining, processing and handling of black coals in Australia. A first step in the process of reducing emission levels is an appreciation of the source, quantity and type of emissions om nine sites. It is shown that greenhouse gas emissions on mine sites come from five sources: energy consumption during mining activities, the coal seam gas liberated due to the extraction process i.e. fugitive emissions, oxidation of carbonaceous wastes, land use, and embodied energy. Also listed are indications of the degree of uncertainty associated with each of the estimates

Microbial production of natural gas from coal and organic-rich shale

Science.gov (United States)

Orem, William

2013-01-01

Natural gas is an important component of the energy mix in the United States, producing greater energy yield per unit weight and less pollution compared to coal and oil. Most of the world’s natural gas resource is thermogenic, produced in the geologic environment over time by high temperature and pressure within deposits of oil, coal, and shale. About 20 percent of the natural gas resource, however, is produced by microorganisms (microbes). Microbes potentially could be used to generate economic quantities of natural gas from otherwise unexploitable coal and shale deposits, from coal and shale from which natural gas has already been recovered, and from waste material such as coal slurry. Little is known, however, about the microbial production of natural gas from coal and shale.

A global coal production forecast with multi-Hubbert cycle analysis

Energy Technology Data Exchange (ETDEWEB)

Patzek, Tadeusz W. [Department of Petroleum and Geosystems Engineering, The University of Texas, Austin, TX 78712 (United States); Croft, Gregory D. [Department of Civil and Environmental Engineering, The University of California, Berkeley, Davis Hall, CA 94720 (United States)

2010-08-15

Based on economic and policy considerations that appear to be unconstrained by geophysics, the Intergovernmental Panel on Climate Change (IPCC) generated forty carbon production and emissions scenarios. In this paper, we develop a base-case scenario for global coal production based on the physical multi-cycle Hubbert analysis of historical production data. Areas with large resources but little production history, such as Alaska and the Russian Far East, are treated as sensitivities on top of this base-case, producing an additional 125 Gt of coal. The value of this approach is that it provides a reality check on the magnitude of carbon emissions in a business-as-usual (BAU) scenario. The resulting base-case is significantly below 36 of the 40 carbon emission scenarios from the IPCC. The global peak of coal production from existing coalfields is predicted to occur close to the year 2011. The peak coal production rate is 160 EJ/y, and the peak carbon emissions from coal burning are 4.0 Gt C (15 Gt CO{sub 2}) per year. After 2011, the production rates of coal and CO{sub 2} decline, reaching 1990 levels by the year 2037, and reaching 50% of the peak value in the year 2047. It is unlikely that future mines will reverse the trend predicted in this BAU scenario. (author)

Estimating Externalities of Natural Gas Fuel Cycles, Report 4

Energy Technology Data Exchange (ETDEWEB)

Barnthouse, L.W.; Cada, G.F.; Cheng, M.-D.; Easterly, C.E.; Kroodsma, R.L.; Lee, R.; Shriner, D.S.; Tolbert, V.R.; Turner, R.S.

1998-01-01

This report describes methods for estimating the external costs (and possibly benefits) to human health and the environment that result from natural gas fuel cycles. Although the concept of externalities is far from simple or precise, it generally refers to effects on individuals' well being, that result from a production or market activity in which the individuals do not participate, or are not fully compensated. In the past two years, the methodological approach that this report describes has quickly become a worldwide standard for estimating externalities of fuel cycles. The approach is generally applicable to any fuel cycle in which a resource, such as coal, hydro, or biomass, is used to generate electric power. This particular report focuses on the production activities, pollution, and impacts when natural gas is used to generate electric power. In the 1990s, natural gas technologies have become, in many countries, the least expensive to build and operate. The scope of this report is on how to estimate the value of externalities--where value is defined as individuals' willingness to pay for beneficial effects, or to avoid undesirable ones. This report is about the methodologies to estimate these externalities, not about how to internalize them through regulations or other public policies. Notwithstanding this limit in scope, consideration of externalities can not be done without considering regulatory, insurance, and other considerations because these institutional factors affect whether costs (and benefits) are in fact external, or whether they are already somehow internalized within the electric power market. Although this report considers such factors to some extent, much analysis yet remains to assess the extent to which estimated costs are indeed external. This report is one of a series of reports on estimating the externalities of fuel cycles. The other reports are on the coal, oil, biomass, hydro, and nuclear fuel cycles, and on general

Carbon dioxide emission in hydrogen production technology from coke oven gas with life cycle approach

Directory of Open Access Journals (Sweden)

Burmistrz Piotr

2016-01-01

Full Text Available The analysis of Carbon Footprint (CF for technology of hydrogen production from cleaned coke oven gas was performed. On the basis of real data and simulation calculations of the production process of hydrogen from coke gas, emission indicators of carbon dioxide (CF were calculated. These indicators are associated with net production of electricity and thermal energy and direct emission of carbon dioxide throughout a whole product life cycle. Product life cycle includes: coal extraction and its transportation to a coking plant, the process of coking coal, purification and reforming of coke oven gas, carbon capture and storage. The values were related to 1 Mg of coking blend and to 1 Mg of the hydrogen produced. The calculation is based on the configuration of hydrogen production from coke oven gas for coking technology available on a commercial scale that uses a technology of coke dry quenching (CDQ. The calculations were made using ChemCAD v.6.0.2 simulator for a steady state of technological process. The analysis of carbon footprint was conducted in accordance with the Life Cycle Assessment (LCA.

Gas distributor for fluidized bed coal gasifier

Science.gov (United States)

Worley, Arthur C.; Zboray, James A.

1980-01-01

A gas distributor for distributing high temperature reaction gases to a fluidized bed of coal particles in a coal gasification process. The distributor includes a pipe with a refractory reinforced lining and a plurality of openings in the lining through which gas is fed into the bed. These feed openings have an expanding tapered shape in the downstream or exhaust direction which aids in reducing the velocity of the gas jets as they enter the bed.

An evaluation of Substitute natural gas production from different coal gasification processes based on modeling

International Nuclear Information System (INIS)

Karellas, S.; Panopoulos, K.D.; Panousis, G.; Rigas, A.; Karl, J.; Kakaras, E.

2012-01-01

Coal and lignite will play a significant role in the future energy production. However, the technical options for the reduction of CO 2 emissions will define the extent of their share in the future energy mix. The production of synthetic or substitute natural gas (SNG) from solid fossil fuels seems to be a very attractive process: coal and lignite can be upgraded into a methane rich gas which can be transported and further used in high efficient power systems coupled with CO 2 sequestration technologies. The aim of this paper is to present a modeling analysis comparison between substitute natural gas production from coal by means of allothermal steam gasification and autothermal oxygen gasification. In order to produce SNG from syngas several unit operations are required such as syngas cooling, cleaning, potential compression and, of course, methanation reactors. Finally the gas which is produced has to be conditioned i.e. removal of unwanted species, such as CO 2 etc. The heat recovered from the overall process is utilized by a steam cycle, producing power. These processes were modeled with the computer software IPSEpro™. An energetic and exergetic analysis of the coal to SNG processes have been realized and compared. -- Highlights: ► The production of SNG from coal is examined. ► The components of the process were simulated for integrated autothermal or allothermal coal gasification to SNG. ► The energetic and exergetic evaluation of the two processes is presented.

Technical comparison between Integrated Gasification Combined Cycle (IGCC) and Natural Gas Combined Cycle (NGCC) power plants

Energy Technology Data Exchange (ETDEWEB)

Ortiz, Pablo Andres Silva; Venturini, Osvaldo Jose; Lora, Electo Eduardo Silva [Federal University of Itajuba - UNIFEI, MG (Brazil). Excellence Group in Thermal Power and Distributed Generation - NEST], e-mails: osvaldo@unifei.edu.br, electo@unifei.edu.br

2010-07-01

Among the emerging clean coal technologies for power generation, Integrated Gasification Combined Cycle (IGCC) and Natural Gas Combined Cycle (NGCC) systems are receiving considerable attention as a potentially attractive option to reduce the emissions of greenhouse gases (GHG). The main reason is because these systems has high efficiency and low emissions in comparison with traditional power generation plants. Currently in IGCC and NGCC systems at demonstration stage is been considered to implement CCS technology. CO{sub 2} emissions can be avoided in a gasification-based power plant because by transferring almost all carbon compounds to CO{sub 2} through the water gas shift (WGS) reaction, then removing the CO{sub 2} before it is diluted in the combustion stage. The aim of this study is to compare the technical performance of an IGCC system that uses Brazilian coal and petroleum coke as fuel with a NGCC system, with the same fixed output power of 450 MW. The first section of this paper presents the plant configurations of IGCC systems. The following section presents an analysis of NGCC technology. (author)

Life-cycle energy and greenhouse gas emission impacts of different corn ethanol plant types

International Nuclear Information System (INIS)

Wang, Michael; Wu, May; Hong Huo

2007-01-01

Since the United States began a programme to develop ethanol as a transportation fuel, its use has increased from 175 million gallons in 1980 to 4.9 billion gallons in 2006. Virtually all of the ethanol used for transportation has been produced from corn. During the period of fuel ethanol growth, corn farming productivity has increased dramatically, and energy use in ethanol plants has been reduced by almost by half. The majority of corn ethanol plants are powered by natural gas. However, as natural gas prices have skyrocketed over the last several years, efforts have been made to further reduce the energy used in ethanol plants or to switch from natural gas to other fuels, such as coal and wood chips. In this paper, we examine nine corn ethanol plant types-categorized according to the type of process fuels employed, use of combined heat and power, and production of wet distiller grains and solubles. We found that these ethanol plant types can have distinctly different energy and greenhouse gas emission effects on a full fuel-cycle basis. In particular, greenhouse gas emission impacts can vary significantly-from a 3% increase if coal is the process fuel to a 52% reduction if wood chips are used. Our results show that, in order to achieve energy and greenhouse gas emission benefits, researchers need to closely examine and differentiate among the types of plants used to produce corn ethanol so that corn ethanol production would move towards a more sustainable path

Process for the gas extraction of coal

Energy Technology Data Exchange (ETDEWEB)

Urquhart, D B

1976-05-20

The object of the invention is a process for the hydroextraction of coal is treated with water and carbon monoxide at a temperature in the region of 300 - 380/sup 0/C. After treatment is completed, the gases are separated from the treated gas; the treated coal is then extracted with an extraction medium during the gas phase at a temperature of at least 400/sup 0/C, the remainder is separated from the gas phase and the coal extract is obtained from the extraction medium. Hydrogenation is preferably carried out at a temperature in the region of 320 - 370/sup 0/C and at a pressure of 200 - 400 at. The time required for treatment with carbon monoxide and water is 1/4 - 2 hours, and in special cases 3/4 - 1 1/2 hours. The coal material itself is nutty slack, of which more than 95% of the coal particles pass through a 1.5 mm mesh sieve. After the hydrogenation the extraction is carried out at a temperature in the region of 400 - 450/sup 0/C. The patent claims relate to the types of extraction media used.

Development of life cycle water-demand coefficients for coal-based power generation technologies

International Nuclear Information System (INIS)

Ali, Babkir; Kumar, Amit

2015-01-01

Highlights: • We develop water consumption and withdrawals coefficients for coal power generation. • We develop life cycle water footprints for 36 coal-based electricity generation pathways. • Different coal power generation technologies were assessed. • Sensitivity analysis of plant performance and coal transportation on water demand. - Abstract: This paper aims to develop benchmark coefficients for water consumption and water withdrawals over the full life cycle of coal-based power generation. This study considered not only all of the unit operations involved in the full electricity generation life cycle but also compared different coal-based power generating technologies. Overall this study develops the life cycle water footprint for 36 different coal-based electricity generation pathways. Power generation pathways involving new technologies of integrated gasification combined cycle (IGCC) or ultra supercritical technology with coal transportation by conventional means and using dry cooling systems have the least complete life cycle water-demand coefficients of about 1 L/kW h. Sensitivity analysis is conducted to study the impact of power plant performance and coal transportation on the water demand coefficients. The consumption coefficient over life cycle of ultra supercritical or IGCC power plants are 0.12 L/kW h higher when conventional transportation of coal is replaced by coal-log pipeline. Similarly, if the conventional transportation of coal is replaced by its transportation in the form of a slurry through a pipeline, the consumption coefficient of a subcritical power plant increases by 0.52 L/kW h

Solid-Gas Coupling Model for Coal-Rock Mass Deformation and Pressure Relief Gas Flow in Protection Layer Mining

OpenAIRE

Zhu, Zhuohui; Feng, Tao; Yuan, Zhigang; Xie, Donghai; Chen, Wei

2018-01-01

The solid-gas coupling model for mining coal-rock mass deformation and pressure relief gas flow in protection layer mining is the key to determine deformation of coal-rock mass and migration law of pressure relief gas of protection layer mining in outburst coal seams. Based on the physical coupling process between coal-rock mass deformation and pressure-relief gas migration, the coupling variable of mining coal-rock mass, a part of governing equations of gas seepage field and deformation fiel...

Energy Conversion Alternatives Study (ECAS), General Electric Phase 1. Volume 2: Advanced energy conversion systems. Part 1: Open-cycle gas turbines

Science.gov (United States)

Brown, D. H.; Corman, J. C.

1976-01-01

Ten energy conversion systems are defined and analyzed in terms of efficiency. These include: open-cycle gas turbine recuperative; open-cycle gas turbine; closed-cycle gas turbine; supercritical CO2 cycle; advanced steam cycle; liquid metal topping cycle; open-cycle MHD; closed-cycle inert gas MHD; closed-cycle liquid metal MHD; and fuel cells. Results are presented.

Geochemical characteristics of Carboniferous-Permian coal-formed gas in Bohai Bay Basin

Energy Technology Data Exchange (ETDEWEB)

Shipeng Huang; Fengrong Liao; Xiaoqi Wu [PetroChina, Beijing (China). Research Institute of Petroleum Exploration & Development

2010-03-15

Coal-formed gas reservoirs have been found in several depressions in Bohai Bay Basin. The gas was mainly generated by the Carboniferous-Permian coal measures, which are good source rocks. The exploration of coal-formed gas has a broad prospect. The main reservoirs of the coal-formed gas are Ordovician, Carboniferous-Permian, and Paleogene stratum. Coal-formed gas in the Bohai Bay Basin is chiefly composed of hydrocarbon gases. The percentage content of carbon dioxide is more than that of the nitrogen gas. The stable carbon isotope values of the hydrocarbon gases of different depressions and different reservoirs usually reversed. The reversed values of gas samples account for 52.1% of all the samples. Reversion values of the carbon isotope are mainly because of the mixing of gases from same source rocks but with different maturity. Among the three main reservoirs, coal-formed gas preserved in Paleogene stratum has the heaviest carbon isotope, the second is the gas in Carboniferous-Permian stratum, and the Ordovician gas possesses the lightest carbon isotope. Based on the analysis of the characteristics of carbon isotope of hydrocarbon gases in well Qishen-1 and the distribution of the Carboniferous-Permian coal measures, the gas of the well is derived from the high-matured Carboniferous-Permian coal measures.

The oilsands of gas: Massive gas from coal resource being commercialized

Energy Technology Data Exchange (ETDEWEB)

Jaremko, D.

2004-04-05

Gas companies are flocking to Alberta to try their hand in coalbed methane extraction, following EnCana Corporation's success two years ago in launching Canada's first commercial-scale natural gas from coal (NGC) operation. There is an estimated 550 trillion cubic feet of methane gas trapped in Alberta's coal fields, and while current production is still insignificant, the rise in demand for natural gas and the decline in conventional resources makes coalbed methane an increasingly appealing option. In the United States NGC accounts for some 10 per cent of gas production and there is no doubt that the interest expressed by American companies to bring their experience and technology to Alberta is a big factor in pushing the wave of appeal of NGC in the province. The Manville coal deposits, lying between 800 and 1,300 metres below the surface, and the Horseshoe Canyon deposit, about 200 to 500 metres down, are the coal zones of greatest interest in Alberta, while the Elk Valley zone is said to have the greatest potential in British Columbia. The article explains the challenges faced by prospective producers in terms of water disposal, noise abatement, environmental footprint, costs versus benefits, and the various technological alternatives available. Suggestions for involving stakeholders in all aspects of the planning of NGC facilities, and for gaining their support, are also included.

Characterization of Coal Porosity for Naturally Tectonically Stressed Coals in Huaibei Coal Field, China

Science.gov (United States)

Li, Xiaoshi; Hou, Quanlin; Li, Zhuo; Wei, Mingming

2014-01-01

The enrichment of coalbed methane (CBM) and the outburst of gas in a coal mine are closely related to the nanopore structure of coal. The evolutionary characteristics of 12 coal nanopore structures under different natural deformational mechanisms (brittle and ductile deformation) are studied using a scanning electron microscope (SEM) and low-temperature nitrogen adsorption. The results indicate that there are mainly submicropores (2~5 nm) and supermicropores (coal and mesopores (10~100 nm) and micropores (5~10 nm) in brittle deformed coal. The cumulative pore volume (V) and surface area (S) in brittle deformed coal are smaller than those in ductile deformed coal which indicates more adsorption space for gas. The coal with the smaller pores exhibits a large surface area, and coal with the larger pores exhibits a large volume for a given pore volume. We also found that the relationship between S and V turns from a positive correlation to a negative correlation when S > 4 m2/g, with pore sizes coal. The nanopore structure (coal. PMID:25126601

Coal fired flue gas mercury emission controls

International Nuclear Information System (INIS)

Wu, Jiang; Pan, Weiguo; Cao, Yan; Pan, Weiping

2015-01-01

Mercury (Hg) is one of the most toxic heavy metals, harmful to both the environment and human health. Hg is released into the atmosphere from natural and anthropogenic sources and its emission control has caused much concern. This book introduces readers to Hg pollution from natural and anthropogenic sources and systematically describes coal-fired flue gas mercury emission control in industry, especially from coal-fired power stations. Mercury emission control theory and experimental research are demonstrated, including how elemental mercury is oxidized into oxidized mercury and the effect of flue gas contents on the mercury speciation transformation process. Mercury emission control methods, such as existing APCDs (air pollution control devices) at power stations, sorbent injection, additives in coal combustion and photo-catalytic methods are introduced in detail. Lab-scale, pilot-scale and full-scale experimental studies of sorbent injection conducted by the authors are presented systematically, helping researchers and engineers to understand how this approach reduces the mercury emissions in flue gas and to apply the methods in mercury emission control at coal-fired power stations.

Coal fired flue gas mercury emission controls

Energy Technology Data Exchange (ETDEWEB)

Wu, Jiang; Pan, Weiguo [Shanghai Univ. of Electric Power (China); Cao, Yan; Pan, Weiping [Western Kentucky Univ., Bowling Green, KY (United States)

2015-05-01

Mercury (Hg) is one of the most toxic heavy metals, harmful to both the environment and human health. Hg is released into the atmosphere from natural and anthropogenic sources and its emission control has caused much concern. This book introduces readers to Hg pollution from natural and anthropogenic sources and systematically describes coal-fired flue gas mercury emission control in industry, especially from coal-fired power stations. Mercury emission control theory and experimental research are demonstrated, including how elemental mercury is oxidized into oxidized mercury and the effect of flue gas contents on the mercury speciation transformation process. Mercury emission control methods, such as existing APCDs (air pollution control devices) at power stations, sorbent injection, additives in coal combustion and photo-catalytic methods are introduced in detail. Lab-scale, pilot-scale and full-scale experimental studies of sorbent injection conducted by the authors are presented systematically, helping researchers and engineers to understand how this approach reduces the mercury emissions in flue gas and to apply the methods in mercury emission control at coal-fired power stations.

Analysis of the use of waste heat obtained from coal-fired units in Organic Rankine Cycles and for brown coal drying

International Nuclear Information System (INIS)

Łukowicz, Henryk; Kochaniewicz, Andrzej

2012-01-01

The ever-increasing restrictions on greenhouse gas emissions have created a need for new energy technologies. One way to meet these new requirements is to optimise the efficiency of power units. This paper presents two energy technologies that, if used, will increase the efficiency of electricity generation. One of the most effective ways to improve the efficiency of brown coal-fired units is by drying the coal that is fed into the boiler. Here, we describe a technology that uses the waste heat obtained from exhaust gases. This paper also presents an analysis of the feasibility of and potential for using waste heat obtained from exhaust gases to feed Organic Rankine Cycles (ORCs). Several low-temperature working fluids were considered, which were selected based on properties that were best suited for these types of cycles. The impact of these working fluids on the efficiency and capacity of the ORC was also examined. The calculations for ORCs fed with waste heat obtained from exhaust gases from hard coal- and brown coal-fired boilers were compared. -- Highlights: ► We describe a technology that uses the waste heat obtained from exhaust gases. ► The impact of using different working fluids with a low boiling point is examined. ► We describe integrating the ORC with the power unit. ► The use of waste heat from boiler exhaust gases to dry brown coal is proposed. ► We demonstrate a possible increase in power unit efficiency.

Prevention and forecasting of coal, rock and gas bursts in mines of Donets Coal Basin in USSR

Energy Technology Data Exchange (ETDEWEB)

Swidzinski, A

1977-11-01

Coal and methane bursts as well as sandstone and methane bursts are typical for the Donets Coal Basin. The most effective way of forecasting coal and methane bursts is drilling holes (3.5 m long, 45 mm diameter) and measuring the initial speed of gas outflow (5 litres/min gas outflow is a critical value). Additional parameters in this method are: coal firmness and porosity as well as thickness of coal bed. Forecasting sandstone and gas bursts is based on taking rock samples while drilling. When a sample 1 meter long consists of 30 to 40 so called discs, the danger of outburst is substantial, with the decreasing number of discs the probability of bursts also decreases. The following methods of prevention are used in the Donets Coal Basin: preparatory extraction of a layer protecting another layer below or above, where there is a danger of gas burst. This method is effective in 50% of all cases. Other methods include: filling coal beds with water under high pressure (average norm 25 1 water per 1 m

Technical review of coal gasifiers for production of synthetic natural gas

International Nuclear Information System (INIS)

Lee, Geun Woo; Shin, Yong Seung

2012-01-01

Because of the increasing cost of oil and natural gas, energy production technologies using coal, including synthetic natural gas (SNG) and integrated gasification combined cycle (IGCC), have attracted attention because of the relatively low cost of coal. During the early stage of a project, the developer or project owner has many options with regard to the selection of a gasifier. In particular, from the viewpoint of feasibility, the gasifier is a key factor in the economic evaluation. This study compares the technical aspects of gasifiers for a real SNG production project in an early stage. A fixed bed slagging gasifier, wet type entrained gasifier, and dry type entrained gasifier, all of which have specific advantages, can be used for the SNG production project. Base on a comparison of the process descriptions and performances of each gasifier, this study presents a selection guideline for a gasifier for an SNG production project that will be beneficial to project developers and EPC (Engineering, Procurement, Construction) contractors

Feasibility study on recovery and utilization of coal mine gas (CMG) at Donetsk Coal Field

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

For the purpose of getting petroleum substitution energy and reducing greenhouse effect gas emission, an investigational study was carried out of the project for methane gas recovery/utilization at the Donbassa coal mine in Ukraine. At the Donbassa coal mine, degassing by test boring is being conducted to reduce the gas emission at coal face for safety, but most of the gas is discharged into the air. In this project, the following were studied: degassing boring/gas induction from bore hole/measurement in gas induction pipe, gas recovery system combined with gas induction in flyash, and installation/operation of gas engine power generation facilities (1,710kW x 7 units) with exhaust heat recovery boiler using the recovered methane gas as fuel. The results obtained were the petroleum substitution amount of 31,000 toe/y and the amount of greenhouse effect gas reduction of 480,000 t/y. In the economical estimation, the initial investment amount was 3 billion yen, the profitability of the total investment used was 2.9%, and the internal earning rate was 6.5%. (NEDO)

Ceramic membranes for gas processing in coal gasification

Energy Technology Data Exchange (ETDEWEB)

Smart, S.; Lin, C.X.C.; Ding, L.; Thambimuthu, K.; da Costa, J.C.D. [University of Queensland, Brisbane, Qld. (Australia)

2010-07-01

Pre-combustion options via coal gasification, especially integrated gasification combined cycle (IGCC) processes, are attracting the attention of governments, industry and the research community as an attractive alternative to conventional power generation. It is possible to build an IGCC plant with CCS with conventional technologies however; these processes are energy intensive and likely to reduce power plant efficiencies. Novel ceramic membrane technologies, in particular molecular sieving silica (MSS) and pervoskite membranes, offer the opportunity to reduce efficiency losses by separating gases at high temperatures and pressures. MSS membranes can be made preferentially selective for H{sub 2}, enabling both enhanced production, via a water-gas shift membrane reactor, and recovery of H{sub 2} from the syngas stream at high temperatures. They also allow CO{sub 2} to be concentrated at high pressures, reducing the compression loads for transportation and enabling simple integration with CO{sub 2} storage or sequestration operations. Perovskite membranes provide a viable alternative to cryogenic distillation for air separation by delivering the tonnage of oxygen required for coal gasification at a reduced cost. In this review we examine ceramic membrane technologies for high temperature gas separation and discuss the operational, mechanical, design and process considerations necessary for their successful integration into IGCC with CCS systems.

Solar coal gasification reactor with pyrolysis gas recycle

Science.gov (United States)

Aiman, William R.; Gregg, David W.

1983-01-01

Coal (or other carbonaceous matter, such as biomass) is converted into a duct gas that is substantially free from hydrocarbons. The coal is fed into a solar reactor (10), and solar energy (20) is directed into the reactor onto coal char, creating a gasification front (16) and a pyrolysis front (12). A gasification zone (32) is produced well above the coal level within the reactor. A pyrolysis zone (34) is produced immediately above the coal level. Steam (18), injected into the reactor adjacent to the gasification zone (32), reacts with char to generate product gases. Solar energy supplies the energy for the endothermic steam-char reaction. The hot product gases (38) flow from the gasification zone (32) to the pyrolysis zone (34) to generate hot char. Gases (38) are withdrawn from the pyrolysis zone (34) and reinjected into the region of the reactor adjacent the gasification zone (32). This eliminates hydrocarbons in the gas by steam reformation on the hot char. The product gas (14) is withdrawn from a region of the reactor between the gasification zone (32) and the pyrolysis zone (34). The product gas will be free of tar and other hydrocarbons, and thus be suitable for use in many processes.

Parametric studies on different gas turbine cycles for a high temperature gas-cooled reactor

International Nuclear Information System (INIS)

Wang Jie; Gu Yihua

2005-01-01

The high temperature gas-cooled reactor (HTGR) coupled with turbine cycle is considered as one of the leading candidates for future nuclear power plants. In this paper, the various types of HTGR gas turbine cycles are concluded as three typical cycles of direct cycle, closed indirect cycle and open indirect cycle. Furthermore they are theoretically converted to three Brayton cycles of helium, nitrogen and air. Those three types of Brayton cycles are thermodynamically analyzed and optimized. The results show that the variety of gas affects the cycle pressure ratio more significantly than other cycle parameters, however, the optimized cycle efficiencies of the three Brayton cycles are almost the same. In addition, the turbomachines which are required for the three optimized Brayton cycles are aerodynamically analyzed and compared and their fundamental characteristics are obtained. Helium turbocompressor has lower stage pressure ratio and more stage number than those for nitrogen and air machines, while helium and nitrogen turbocompressors have shorter blade length than that for air machine

Variations in pore characteristics in high volatile bituminous coals: Implications for coal bed gas content

Science.gov (United States)

Mastalerz, Maria; Drobniak, A.; Strapoc, D.; Solano-Acosta, W.; Rupp, J.

2008-01-01

The Seelyville Coal Member of the Linton Formation (Pennsylvanian) in Indiana was studied to: 1) understand variations in pore characteristics within a coal seam at a single location and compare these variations with changes occurring between the same coal at different locations, 2) elaborate on the influence of mineral-matter and maceral composition on mesopore and micropore characteristics, and 3) discuss implications of these variations for coal bed gas content. The coal is high volatile bituminous rank with R0 ranging from 0.57% to 0.60%. BET specific surface areas (determined by nitrogen adsorption) of the coals samples studied range from 1.8 to 22.9??m2/g, BJH adsorption mesopore volumes from 0.0041 to 0.0339??cm3/g, and micropore volumes (determined by carbon dioxide adsorption) from 0.0315 to 0.0540??cm3/g. The coals that had the largest specific surface areas and largest mesopore volumes occur at the shallowest depths, whereas the smallest values for these two parameters occur in the deepest coals. Micropore volumes, in contrast, are not depth-dependent. In the coal samples examined for this study, mineral-matter content influenced both specific surface area as well as mesopore and micropore volumes. It is especially clear in the case of micropores, where an increase in mineral-matter content parallels the decrease of micropore volume of the coal. No obvious relationships were observed between the total vitrinite content and pore characteristics but, after splitting vitrinite into individual macerals, we see that collotelinite influences both meso- and micropore volume positively, whereas collodetrinite contributes to the reduction of mesopore and micropore volumes. There are large variations in gas content within a single coal at a single location. Because of this variability, the entire thickness of the coal must be desorbed in order to determine gas content reliably and to accurately calculate the level of gas saturation. ?? 2008 Elsevier B.V. All

Closed cycle high-repetition-rate pulsed HF laser

Science.gov (United States)

Harris, Michael R.; Morris, A. V.; Gorton, Eric K.

1997-04-01

The design and performance of a closed cycle high repetition rate HF laser is described. A short pulse, glow discharge is formed in a 10 SF6:1 H2 gas mixture at a total pressure of approximately 110 torr within a 15 by 0.5 by 0.5 cm3 volume. Transverse, recirculated gas flow adequate to enable repetitive operation up to 3 kHz is imposed by a centrifugal fan. The fan also forces the gas through a scrubber cell to eliminate ground state HF from the gas stream. An automated gas make-up system replenishes spent gas removed by the scrubber. Typical mean laser output powers up to 3 W can be maintained for extended periods of operation.

Greenhouse gas emission factor for coal power chain in China and the comparison with nuclear power chain

International Nuclear Information System (INIS)

Ma Zhonghai; Pan Ziqiang; He Huimin

1999-01-01

The Greenhouse Gas Emission for coal power chain in China is analyzed in detail and comprehensively by using the Life Cycle Analysis method. The Greenhouse Gas Emission Factors (GGEF) in each link and for the total power chain are calculated. The total GGEF for coal power chain is 1302.3 gCO 2 /kWh, about 40 times more than that for nuclear power chain. And consequently greenhouse effect could not be aggravated further by nuclear power. The energy strategy for nuclear power development is one of reality ways to retard the greenhouse effect, put resources into rational use and protect environment

The Late Paleozoic relative gas fields of coal measure in China and their significances on the natural gas industry

Directory of Open Access Journals (Sweden)

Chenchen Fang

2016-12-01

Full Text Available The coal measure gas sources of coal-derived gas fields in the Late Paleozoic China are the Lower Carboniferous Dishuiquan Formation, the Upper Carboniferous Batamayineishan Formation and Benxi Formation, the Lower Permian Taiyuan Formation and Shanxi Formation, and the Upper Permian Longtan Formation. The coal-derived gas accumulates in Ordovician, Carboniferous, Permian, and Paleocene reservoirs and are distributed in Ordos Basin, Bohai Bay Basin, Junggar Basin, and Sichuan Basin. There are 16 gas fields and 12 of them are large gas fields such as the Sulige large gas field which is China's largest reserve with the highest annual output. According to component and alkane carbon isotope data of 99 gas samples, they are distinguished to be coal-derived gas from coal-derived gas with δ13C2 > −28.5‰ and δ13C1 -δ13C2 -δ13C3 identification chart. The Late Paleozoic relative gas fields of coal measure are significant for the Chinese natural gas industry: proven natural gas geological reserves and annual output of them account for 1/3 in China, and the gas source of three significant large gas fields is coal-derived, which of five significant large gas fields supporting China to be a great gas producing country. The average reserves of the gas fields and the large gas fields formed from the late Paleozoic coal measure are 5.3 and 1.7 times that of the gas fields and the large gas fields in China.

Permeability changes in coal resulting from gas desorption. Final report

Energy Technology Data Exchange (ETDEWEB)

Levine, J.R.; Johnson, P.W.

1992-11-30

This report documents studies on the effects of gas sorption on coal, with the intent of eventually evaluating how sorption and strain affect permeability. These studies were, carried out at the University of Alabama during the period from 1989 through 1992. Two major experimental methods were developed and used. In the strain experiments, electronic strain gauges were attached to polished blocks of coal in order to measure linear and volumetric swelling due to gas sorption. The effects of bedding plane orientation, of gas type, and of coal type were investigated. In the gravimetric experiment the weight of small samples of coal was measured during exposure to high pressure gases. Sample measurements were corrected for buoyancy effects and for sample swelling, and the results were plotted in the form of Langmuir isotherms. Experiments were conducted to determine the effect of grain size, coal type, moisture, and of sorbant gas. The advantage of this method is that it can be applied to very small samples, and it enabled comparison liptinite versus vitrinite concentrates, and kerogen rich versus kerogen depleted oil shales. Also included is a detailed discussion of the makeup of coal and its effect on gas sorption behavior.

Gas core reactors for coal gasification

International Nuclear Information System (INIS)

Weinstein, H.

1976-01-01

The concept of using a gas core reactor to produce hydrogen directly from coal and water is presented. It is shown that the chemical equilibrium of the process is strongly in favor of the production of H 2 and CO in the reactor cavity, indicating a 98 percent conversion of water and coal at only 1500 0 K. At lower temperatures in the moderator-reflector cooling channels the equilibrium strongly favors the conversion of CO and additional H 2 O to CO 2 and H 2 . Furthermore, it is shown the H 2 obtained per pound of carbon has 23 percent greater heating value than the carbon so that some nuclear energy is also fixed. Finally, a gas core reactor plant floating in the ocean is conceptualized which produces H 2 , fresh water and sea salts from coal

To capabilities of heat engines with gas working medium in closed cycle

International Nuclear Information System (INIS)

Kotov, V.M.; Tikhomirov, L.N.; Rajkhanov, N.A.; Kotov, S.V.

2003-01-01

The effort gives analysis of performance of engines and heat pumps with closed cycles based on use of well practiced adiabatic and isobaric processes. Advantages of theses cycles are demonstrated as compared to Stirling engines, and capabilities of their application in piston machines. (author)

Indication to distinguish the burst region of coal gas from seismic data

Energy Technology Data Exchange (ETDEWEB)

Jian-yuan Cheng; Hong-wei Tang; Lin Xu; Yan-fang Li [China Coal Research Institute, Xi' an (China). Xi' an Research Institute

2009-09-15

The velocity of an over-burst coal seam is about 1/3 compared to a normal coal seam based on laboratory test results. This can be considered as a basis to confirm the area of coal and gas burst by seismic exploration technique. Similarly, the simulation result of the theoretical seismic model shows that there is obvious distinction between over-burst coal and normal coal based on the coal reflection's travel-time, energy and frequency. The results from the actual seismic data acquired in the coal and gas over-burst cases is consistent with that of the laboratory and seismic modeling; that is, in the coal and gas burst region, seismic reflection travel time is delayed, seismic amplitude is weakened and seismic frequency is reduced. Therefore, it can be concluded that seismic exploration technique is promising for use in distinguishing coal and gas over-burst regions based on the variation of seismic reflection travel time, amplitude and frequency. 7 refs., 6 figs.

Numerical Assessment of the Influences of Gas Pressure on Coal Burst Liability

Directory of Open Access Journals (Sweden)

Haochen Zhao

2018-01-01

Full Text Available When coal mines exploit deep seams with high-gas content, risks are encountered due to the additional high likelihood of rock bursting potential problems. The bursts of coal pillars usually lead to severe fatalities, injuries, and destruction of property, including impeding access to active mine workings underground. The danger exists given that conditions in the already highly brittle coal material can be exacerbated by high stress and high gas pressure conditions. It is thus critical to develop methods that improve current understanding about bursting liability, and techniques to forecast or prevent coal bursting in underground coal mines. This study uses field data from a deep coal mine, and numerical modeling to investigate the effects of gas pressure and mechanical compressive stresses on coal bursting liability in high gas content coal seams. The bursting energy index is adopted to determine the coal bursting liability under high gas pressure conditions. The adopted methodology uses a two-staged approach comprising investigating the influence of gas pressure on the bursting liability of coal pillar, and the influence of the gas pressure on the resulting pillar failure mode. Based on numerical simulations of coal pillars, correlations are observed between the magnitudes of gas pressures and the bursting energy index. Irrespective of pillar size, failure time is shortest when the gas pressure achieves a threshold value between 50 kPa to 70 kPa. At 50 kPa, the value of the BEI increases by 50% going from the 4 m pillar to the 6 m pillar. The value of the BEI increases by 43% going from the 6 m high pillar to the 8 m high pillar at 50 kPa. When pillars fail there is a degree of stress relief leading to a reduction in bursting liability. The results suggest that before 50 kPa, pillar failure is largely due to mechanical loading. After 50 kPa, pillar failure is largely due to excessive gas pressures.

Life Cycle Assessment of Coal-fired Power Production

Energy Technology Data Exchange (ETDEWEB)

Spath, P. L.; Mann, M. K.; Kerr, D. R.

1999-09-01

Coal has the largest share of utility power generation in the US, accounting for approximately 56% of all utility-produced electricity (US DOE, 1998). Therefore, understanding the environmental implications of producing electricity from coal is an important component of any plan to reduce total emissions and resource consumption. A life cycle assessment (LCA) on the production of electricity from coal was performed in order to examine the environmental aspects of current and future pulverized coal boiler systems. Three systems were examined: (1) a plant that represents the average emissions and efficiency of currently operating coal-fired power plants in the US (this tells us about the status quo), (2) a new coal-fired power plant that meets the New Source Performance Standards (NSPS), and (3) a highly advanced coal-fired power plant utilizing a low emission boiler system (LEBS).

Biological conversion of coal gas to methane

Energy Technology Data Exchange (ETDEWEB)

Barik, S; Vega, J L; Clausen, E C; Gaddy, J L

1988-08-01

Biological conversion of low-Btu coal synthesis gas to higher Btu methane was demonstrated using both pure co-cultures and/or adapted-mixed anaerobic bacteria. Peptostreptococcus productus metabolized coal gas to mainly acetate and CO/sub 2/. The co-cultures containing methanogens converted these products to methane. In mixed culture studies, CH/sub 4/ and small amounts of acetate were produced. Reactor studies using stirred-tank and immobilized cell reactors exhibited excellent potential to convert CO, CO/sub 2/ and H/sub 2/ to methane at higher gas flow rates. Gas retention times ranging from 0.7 to 2 hours and high agitation were required for 90 percent CO conversion in these systems. This paper also illustrates the potential of biological methanation and demonstrates the need for good mass transfer in converting gas phase substrates. 21 refs., 1 fig., 7 tabs.

Oil, Gas, Coal and Electricity - Quarterly statistics. Second Quarter 2012

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-07-15

This publication provides up-to-date and detailed quarterly statistics on oil, coal, natural gas and electricity for the OECD countries. Oil statistics cover production, trade, refinery intake and output, stock changes and consumption for crude oil, NGL and nine selected oil product groups. Statistics for electricity, natural gas, hard coal and brown coal show supply and trade. Import and export data are reported by origin and destination. Moreover, oil and hard coal production are reported on a worldwide basis.

The modernization potential of gas turbines in the coal-fired power industry thermal and economic effectiveness

CERN Document Server

Bartnik, Ryszard

2013-01-01

The opportunity of repowering the existing condensing power stations by means of  gas turbogenerators offers an important opportunity to considerably improvement of their energy efficiency. The Modernization Potential of Gas turbines in the Coal-Fired Power Industry presents the methodology, calculation procedures and tools used to support enterprise planning for adapting power stations to dual-fuel gas-steam combined-cycle technologies. Both the conceptual and practical aspects of the conversion of existing coal-fired power plants is covered. Discussions of the feasibility, advantages and disadvantages and possible methods are supported by chapters presenting equations of energy efficiency for the conditions of repowering a power unit by installing a gas turbogenerator in a parallel system and the results of technical calculations involving the selection heating structures of heat recovery steam generators. A methodology for analyzing thermodynamic and economic effectiveness for the selection of a structure...

Two-stage coal liquefaction without gas-phase hydrogen

Science.gov (United States)

Stephens, H.P.

1986-06-05

A process is provided for the production of a hydrogen-donor solvent useful in the liquefaction of coal, wherein the water-gas shift reaction is used to produce hydrogen while simultaneously hydrogenating a donor solvent. A process for the liquefaction of coal using said solvent is also provided. The process enables avoiding the use of a separate water-gas shift reactor as well as high pressure equipment for liquefaction. 3 tabs.

Old King Coal to the rescue as gas supplies dwindle

International Nuclear Information System (INIS)

Westbury, R. J.; Balash, A.

2000-01-01

Rumours persist about an impending shortage of natural gas, despite solid evidence to suggest that there are vast reserves yet to be discovered. The foundation for the rumours are the fact of increasing per capita demand for natural gas; insufficient financial incentive to vigorously pursue exploration since the easily discoverable reserves of oil and gas have been found long ago, and the cost of discovering oil and natural gas in more difficult formations have risen faster than the rate of inflation. Other reasons cited from time to time include the lack of present day technology that can extract the vast amounts of gas and oil in remaining reserves, and references to the exploding population of the developing world such as India, Pakistan and China, who are major users of oil and gas. It is not expected that nuclear power, wind, solar and geothermal energy sources will become fashionable in the near future, leaving hydrocarbons, and mainly coal, as the only readily available energy source. Although because of the high sulphur content coal gets a bad press, it is a fact that coal-fired power plants, equipped with modern scrubbing equipment, could meet the same pollution limits as natural gas-fired plants. For the moment, the power generating industry is reluctant to invest in the costly equipment for clean coal-fired plants, however, this short-sighted view may well lead to increases in the price of natural gas that will mimic the results of the OPEC increases in crude oil in the 1970s. These authors contend that if gas is wasted in power generation, society will suffer the reappearance of coal-fired home heating furnaces with all the attendant increases in air pollution due to the relatively inefficient combustion of coal in domestic space heating appliances

18 CFR 270.302 - Occluded natural gas produced from coal seams.

Science.gov (United States)

2010-04-01

... produced from coal seams. 270.302 Section 270.302 Conservation of Power and Water Resources FEDERAL ENERGY... produced from coal seams. A person seeking a determination that natural gas is occluded natural gas produced from coal seams must file an application with the jurisdictional agency which contains the...

Report on results of feasibility study in fiscal 1986 on use of coal in next generation high efficiency power generation system - research commissioned by Moonlight project propulsion room of Agency of Industrial Science and Technology. MHD generation subcommittee; 1986 nendo jisedai kokoritsu hatsuden system no sekitan gas riyo feasibility chosa kenkyu seika hokokusho (Kogyo Gijutsuin Moonlight keikaku suishinshitsu itaku chosa). MHD hatsuden bunkakai

Energy Technology Data Exchange (ETDEWEB)

NONE

1987-03-01

A research study was done on MHD generation by coal gasificating combustion. MHD generation is a very attractive power generation system such that efficiency is as high as 55%, that preservation of the environment is superior, and that coal can be used as fuel. The open cycle seems suitable for a one million kW class as a base load following up load fluctuation of approximately 20%, while the closed cycle for 200-300 thousand kW class doing daily start-stop. With a mind to a scale of 30 MWt, in the open cycle, R and D is required in such items as a coal gas combustor, generation channel, high temperature air heater, and seed/slag recovery device. In the closed cycle, R and D is required in the generation channel, high temperature helium heater/high temperature valve, seed injection/recovery device, operation technique of helium closed loop, etc.. Moreover, as a total system, development is necessary in the areas of conceptual design and optimization method, partial load operation and DSS operation method, for example. (NEDO)

Development of a high-performance, coal-fired power generating system with a pyrolysis gas and char-fired high-temperature furnace

Energy Technology Data Exchange (ETDEWEB)

Shenker, J.

1995-11-01

A high-performance power system (HIPPS) is being developed. This system is a coal-fired, combined-cycle plant that will have an efficiency of at least 47 percent, based on the higher heating value of the fuel. The original emissions goal of the project was for NOx and SOx to each be below 0.15 lb/MMBtu. In the Phase 2 RFP this emissions goal was reduced to 0.06 lb/MMBtu. The ultimate goal of HIPPS is to have an all-coal-fueled system, but initial versions of the system are allowed up to 35 percent heat input from natural gas. Foster Wheeler Development Corporation is currently leading a team effort with AlliedSignal, Bechtel, Foster Wheeler Energy Corporation, Research-Cottrell, TRW and Westinghouse. Previous work on the project was also done by General Electric. The HIPPS plant will use a high-Temperature Advanced Furnace (HITAF) to achieve combined-cycle operation with coal as the primary fuel. The HITAF is an atmospheric-pressure, pulverized-fuel-fired boiler/air heater. The HITAF is used to heat air for the gas turbine and also to transfer heat to the steam cycle. its design and functions are very similar to conventional PC boilers. Some important differences, however, arise from the requirements of the combined cycle operation.

Development of a high-performance, coal-fired power generating system with a pyrolysis gas and char-fired high-temperature furnace

International Nuclear Information System (INIS)

Shenker, J.

1995-01-01

A high-performance power system (HIPPS) is being developed. This system is a coal-fired, combined-cycle plant that will have an efficiency of at least 47 percent, based on the higher heating value of the fuel. The original emissions goal of the project was for NOx and SOx to each be below 0.15 lb/MMBtu. In the Phase 2 RFP this emissions goal was reduced to 0.06 lb/MMBtu. The ultimate goal of HIPPS is to have an all-coal-fueled system, but initial versions of the system are allowed up to 35 percent heat input from natural gas. Foster Wheeler Development Corporation is currently leading a team effort with AlliedSignal, Bechtel, Foster Wheeler Energy Corporation, Research-Cottrell, TRW and Westinghouse. Previous work on the project was also done by General Electric. The HIPPS plant will use a high-Temperature Advanced Furnace (HITAF) to achieve combined-cycle operation with coal as the primary fuel. The HITAF is an atmospheric-pressure, pulverized-fuel-fired boiler/air heater. The HITAF is used to heat air for the gas turbine and also to transfer heat to the steam cycle. its design and functions are very similar to conventional PC boilers. Some important differences, however, arise from the requirements of the combined cycle operation

Impact of Contaminants Present in Coal-Biomass Derived Synthesis Gas on Water-gas Shift and Fischer-Tropsch Synthesis Catalysts

Energy Technology Data Exchange (ETDEWEB)

Alptekin, Gokhan [TDA Research, Inc., Wheat Ridge, CO (United States)

2013-02-15

Co-gasification of biomass and coal in large-scale, Integrated Gasification Combined Cycle (IGCC) plants increases the efficiency and reduces the environmental impact of making synthesis gas ("syngas") that can be used in Coal-Biomass-to-Liquids (CBTL) processes for producing transportation fuels. However, the water-gas shift (WGS) and Fischer-Tropsch synthesis (FTS) catalysts used in these processes may be poisoned by multiple contaminants found in coal-biomass derived syngas; sulfur species, trace toxic metals, halides, nitrogen species, the vapors of alkali metals and their salts (e.g., KCl and NaCl), ammonia, and phosphorous. Thus, it is essential to develop a fundamental understanding of poisoning/inhibition mechanisms before investing in the development of any costly mitigation technologies. We therefore investigated the impact of potential contaminants (H₂S, NH₃, HCN, AsH₃, PH₃, HCl, NaCl, KCl, AS₃, NH₄NO₃, NH₄OH, KNO₃, HBr, HF, and HNO₃) on the performance and lifetime of commercially available and generic (prepared in-house) WGS and FT catalysts.

Problems of coal-based power generation

International Nuclear Information System (INIS)

Noskievic, P.

1996-01-01

Current problems of and future trends in coal-based power generation are discussed. The present situation is as follows: coal, oil and gas contribute to world fossil fuel resources 75%, 14%, and 11%, respectively, and if the current trend will continue, will be depleted in 240, 50, and 60 years, respectively; the maximum resource estimates (including resources that have not yet been discovered) are 50% higher for oil and 100% higher for gas, for coal such estimates have not been made. While the world prices of coal are expected to remain virtually constant, the prices of gas will probably increase to be twice as high in 2010. Thus, the role of coal may be higher in the next century than it is now, provided that due attention is paid to improving the efficiency of coal-fired power plants and reducing their adverse environmental effects. A comparison of economic data for coal-fired and gas-fired power plants is as follows: Investment cost (USD/kW): 1400, 800; fixed running cost (USD/kW.y): 33.67, 9.0; variable running cost (USD/kWh): 0.30, 0.15; power use (kJ/kWh): 10.29, 7.91; annual availability (%): 70, 50; fuel price (USD/GJ): 1.00, 4.30; power price (USD/kWh): 4.28, 5.52. The investment cost for coal-fired plants covers new construction including flue gas purification. The integrated gasification combined cycle (IGCC) seems to be the future of coal-based power generation. The future problems to be addressed include ways to reduce air pollution, improving the efficiency of the gas-steam cycle, and improving the combustion process particularly with a view to reducing substantially its environmental impact. (P.A.). 4 figs., 4 tabs., 9 refs

Acoustic Emission Characteristics of Gas-Containing Coal during Loading Dilation Process

Directory of Open Access Journals (Sweden)

Z. Q. Yin

2015-12-01

Full Text Available Raw coal was used as the study object in this paper to identify the evolution characteristics of acoustic emission (AE during the dilation process of gas-containing coal. The coal specimens were stored in gas seal devices filled with gas at different pressures (0, 0.5, 1.0, and 1.5 MPa for 24 h prior to testing. Then, the specimens were tested in a rock-testing machine, and the deformation and crack fracture patterns were recorded by using strain gauges and an AE system. The axial and volumetric strains–stress curves were analyzed in relation to the AE and the failure mode. Results show that as gas pressure increases, the uniaxial compression strength and elasticity modulus of gas-containing coal decreases, whereas the Poisson’s ratio increases. In all the coal specimens, the dilation initiation stress decreases, and the dilation degree increases. During the dilation process, before the loaded coal specimens reach peak stress, and as the load increases, the changes in the specimens and in the AE energy parameter of specimens can be divided into four phases: crack closure deformation, elastic deformation, stable crack propagation, and unstable crack propagation (dilation process. Across the four phases, the AE energy increases evidently during crack closure and elastic deformation but decreases during stable crack propagation. As the gas pressure increases, the AE signal frequency increases from 4.5 KHz to 8.1 KHz during the dilation process. Thus, the gas presence in coal specimens exerts a significant influence on the closure of sample cracks and dilation damage.

Zero-Headspace Coal-Core Gas Desorption Canister, Revised Desorption Data Analysis Spreadsheets and a Dry Canister Heating System

Science.gov (United States)

Barker, Charles E.; Dallegge, Todd A.

2005-01-01

Coal desorption techniques typically use the U.S. Bureau of Mines (USBM) canister-desorption method as described by Diamond and Levine (1981), Close and Erwin (1989), Ryan and Dawson (1993), McLennan and others (1994), Mavor and Nelson (1997) and Diamond and Schatzel (1998). However, the coal desorption canister designs historically used with this method have an inherent flaw that allows a significant gas-filled headspace bubble to remain in the canister that later has to be compensated for by correcting the measured desorbed gas volume with a mathematical headspace volume correction (McLennan and others, 1994; Mavor and Nelson, 1997).

The shell coal gasification process

Energy Technology Data Exchange (ETDEWEB)

Koenders, L.O.M.; Zuideveld, P.O. [Shell Internationale Petroleum Maatschappij B.V., The Hague (Netherlands)

1995-12-01

Future Integrated Coal Gasification Combined Cycle (ICGCC) power plants will have superior environmental performance and efficiency. The Shell Coal Gasification Process (SCGP) is a clean coal technology, which can convert a wide range of coals into clean syngas for high efficiency electricity generation in an ICGCC plant. SCGP flexibility has been demonstrated for high-rank bituminous coals to low rank lignites and petroleum coke, and the process is well suited for combined cycle power generation, resulting in efficiencies of 42 to 46% (LHV), depending on choice of coal and gas turbine efficiency. In the Netherlands, a 250 MWe coal gasification combined cycle plant based on Shell technology has been built by Demkolec, a development partnership of the Dutch Electricity Generating Board (N.V. Sep). The construction of the unit was completed end 1993 and is now followed by start-up and a 3 year demonstration period, after that the plant will be part of the Dutch electricity generating system.

Study on Fluid-solid Coupling Mathematical Models and Numerical Simulation of Coal Containing Gas

Science.gov (United States)

Xu, Gang; Hao, Meng; Jin, Hongwei

2018-02-01

Based on coal seam gas migration theory under multi-physics field coupling effect, fluid-solid coupling model of coal seam gas was build using elastic mechanics, fluid mechanics in porous medium and effective stress principle. Gas seepage behavior under different original gas pressure was simulated. Results indicated that residual gas pressure, gas pressure gradient and gas low were bigger when original gas pressure was higher. Coal permeability distribution decreased exponentially when original gas pressure was lower than critical pressure. Coal permeability decreased rapidly first and then increased slowly when original pressure was higher than critical pressure.

Propagation characteristics of pulverized coal and gas two-phase flow during an outburst.

Science.gov (United States)

Zhou, Aitao; Wang, Kai; Fan, Lingpeng; Tao, Bo

2017-01-01

Coal and gas outbursts are dynamic failures that can involve the ejection of thousands tons of pulverized coal, as well as considerable volumes of gas, into a limited working space within a short period. The two-phase flow of gas and pulverized coal that occurs during an outburst can lead to fatalities and destroy underground equipment. This article examines the interaction mechanism between pulverized coal and gas flow. Based on the role of gas expansion energy in the development stage of outbursts, a numerical simulation method is proposed for investigating the propagation characteristics of the two-phase flow. This simulation method was verified by a shock tube experiment involving pulverized coal and gas flow. The experimental and simulated results both demonstrate that the instantaneous ejection of pulverized coal and gas flow can form outburst shock waves. These are attenuated along the propagation direction, and the volume fraction of pulverized coal in the two-phase flow has significant influence on attenuation of the outburst shock wave. As a whole, pulverized coal flow has a negative impact on gas flow, which makes a great loss of large amounts of initial energy, blocking the propagation of gas flow. According to comparison of numerical results for different roadway types, the attenuation effect of T-type roadways is best. In the propagation of shock wave, reflection and diffraction of shock wave interact through the complex roadway types.

Coal-fired high performance power generating system. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-08-31

As a result of the investigations carried out during Phase 1 of the Engineering Development of Coal-Fired High-Performance Power Generation Systems (Combustion 2000), the UTRC-led Combustion 2000 Team is recommending the development of an advanced high performance power generation system (HIPPS) whose high efficiency and minimal pollutant emissions will enable the US to use its abundant coal resources to satisfy current and future demand for electric power. The high efficiency of the power plant, which is the key to minimizing the environmental impact of coal, can only be achieved using a modern gas turbine system. Minimization of emissions can be achieved by combustor design, and advanced air pollution control devices. The commercial plant design described herein is a combined cycle using either a frame-type gas turbine or an intercooled aeroderivative with clean air as the working fluid. The air is heated by a coal-fired high temperature advanced furnace (HITAF). The best performance from the cycle is achieved by using a modern aeroderivative gas turbine, such as the intercooled FT4000. A simplified schematic is shown. In the UTRC HIPPS, the conversion efficiency for the heavy frame gas turbine version will be 47.4% (HHV) compared to the approximately 35% that is achieved in conventional coal-fired plants. This cycle is based on a gas turbine operating at turbine inlet temperatures approaching 2,500 F. Using an aeroderivative type gas turbine, efficiencies of over 49% could be realized in advanced cycle configuration (Humid Air Turbine, or HAT). Performance of these power plants is given in a table.

The role of the MHTGR in coal gasification processes

International Nuclear Information System (INIS)

McDonald, C.F.

1988-01-01

The nation will likely become more and more dependent on natural gas and while this will stimulate new exploration and increased production, the time will surely come when global depletion of this resource will require the use of synthetic natural gas (SNG) to support the established nationwide infrastructure. The U.S. is estimated to have coal reserves nearing 500 billion tons that are mineable on an economic base. The Modular High Temperature Gas-Cooled Reactor (MHTGR) steam cycle plant can play an important role in the process of producing SNG from coal to supplement natural gas supplies. Coal-to-gas plants need heat (predominantly steam) and electricity for operation. This energy can be supplied by combustion of coal (autothermal process), but this results in a loss of more than 40% of the coal energy input. From the resource conservation standpoint, using an MHTGR heat source is attractive since much of the valuable fossil raw material can be substituted by clean nuclear energy. Also, air pollution is lowered drastically. This paper highlights how a near-term steam cycle MHTGR plant, based on proven technology and operating in a cogeneration mode, could be coupled with existing coal gasification processes to meet the projected increase in gas consumption in an environmentally acceptable manner

Is there a future for coal in Ontario?

International Nuclear Information System (INIS)

Davies, G.

2004-01-01

This PowerPoint presentation examined the efficacy of a governmental decision in 2003 to close all Ontario coal stations by 2007. Coal currently represents one quarter of Ontario's energy and capacity. Projected supply and demand gaps for Ontario were presented for up to 2020. Ontario's supply options were outlined. It was noted that between $30 and $40 billion in investment in the electricity sector will be needed over the next 10 to 15 years. It was observed that closing coal plants may reduce pollution by 6 per cent at a cost of $2 billion. More than half the smog affecting Ontario comes from the United States, while much of the remaining half is caused by transportation emissions. Details of energy strategies related to coal in the United States were discussed. New coal power plant technologies include supercritical combustion; advanced air pollution control; circulating fluidized bed combustion and integrated coal gasification combined cycles. Coal power plant performance criteria were presented. Various research programs in the United States were reviewed, and roadmap performance targets were presented. It was concluded that high prices and uncertainty for natural gas fired options may reinforce views on the need to rethink coal closures. A strategy was recommended in which Ontario pursued economic options for reducing emissions across all sectors. New investments in latest and best technology for emissions reduction in Ontario's coal-fired stations were recommended, as well as a North American agreement on clean air, and increased Canadian participation in U.S. technology development efforts for clean coal and zero emissions plants by 2025. tabs., figs

Fast and safe gas detection from underground coal fire by drone fly over

International Nuclear Information System (INIS)

Dunnington, Lucila; Nakagawa, Masami

2017-01-01

Underground coal fires start naturally or as a result of human activities. Besides burning away the important non-renewable energy resource and causing financial losses, burning coal seams emit carbon dioxide, carbon monoxide, sulfur oxide and methane, and is a leading cause of smog, acid rain, global warming, and air toxins. In the U.S. alone, the combined cost of coal-fire remediation projects that have been completed, budgeted, or projected by the U.S. Department of the Interior's Office of Surface Mining Remediation and Enforcement (OSM), exceeds $1 billion. It is estimated that these fires generate as much as 3% of the world's annual carbon dioxide emissions and consume as much as 5% of its minable coal. Considering the magnitude of environmental impact and economic loss caused by burning underground coal seams, we have developed a new, safe, reliable surface measurement of coal fire gases to assess the nature of underground coal fires. We use a drone mounted with gas sensors. Drone collected gas concentration data provides a safe alternative for evaluating the rank of a burning coal seam. In this study, a new method of determining coal rank by gas ratios is developed. Coal rank is valuable for defining parameters of a coal seam such as burn temperature, burn rate, and volume of burning seam. - Graphical abstract: Concluding Figure for Gas Ratios: Plotted points and ranges of adjusted literature data. Stars represent bituminous and subbituminous coal types; Ovals represent lignite. - Highlights: • Recognize underground coal fire as a potential source of energy. • Developed a creative, safe, reliable and fast gas detection method. • Developed a concept of gas ratio measurement method that can provide more accurate description of underground burning coal resource.

Energy supply: No gas from coal

Energy Technology Data Exchange (ETDEWEB)

Kempkens, W

1983-03-01

In the last twelve years the share of natural gas in the total consumption of primary energy has increased twelve-fold and now amounts to 16 per cent. One-third of this is produced in West Germany. Although world deposits will last well into the next century, attempts are already being made to perfect techniques for obtaining gas from coal. However, the cubic metre price of synthetic gas is still anything but competitive.

Experimental Investigation of Closed Porosity of Inorganic Solidified Foam Designed to Prevent Coal Fires

Directory of Open Access Journals (Sweden)

Yi Lu

2015-01-01

Full Text Available In order to overcome the deficiency of the existing fire control technology and control coal spontaneous combustion by sealing air leakages in coal mines, inorganic solidified foam (ISF with high closed porosity was developed. The effect of sodium dodecyl sulfate (SDS concentration on the porosity of the foams was investigated. The results showed that the optimized closed porosity of the solidified foam was 38.65 wt.% for an SDS concentration of approximately 7.4×10-3 mol/L. Based on observations of the microstructure of the pore walls after solidification, it was inferred that an equilibrium between the hydration process and the drainage process existed. Therefore, the ISF was improved using three different systems. Gelatin can increase the viscosity of the continuous phase to form a viscoelastic film around the air cells, and the SDS + gelatin system can create a mixed surfactant layer at gas/liquid interfaces. The accelerator (AC accelerates the hydration process and coagulation of the pore walls before the end of drainage. The mixed SDS + gelatin + AC systems produced an ISF with a total porosity of 79.89% and a closed porosity of 66.89%, which verified the proposed stabilization mechanism.

Conceptual design study of a coal gasification combined-cycle powerplant for industrial cogeneration

Science.gov (United States)

Bloomfield, H. S.; Nelson, S. G.; Straight, H. F.; Subramaniam, T. K.; Winklepleck, R. G.

1981-01-01

A conceptual design study was conducted to assess technical feasibility, environmental characteristics, and economics of coal gasification. The feasibility of a coal gasification combined cycle cogeneration powerplant was examined in response to energy needs and to national policy aimed at decreasing dependence on oil and natural gas. The powerplant provides the steam heating and baseload electrical requirements while serving as a prototype for industrial cogeneration and a modular building block for utility applications. The following topics are discussed: (1) screening of candidate gasification, sulfur removal and power conversion components; (2) definition of a reference system; (3) quantification of plant emissions and waste streams; (4) estimates of capital and operating costs; and (5) a procurement and construction schedule. It is concluded that the proposed powerplant is technically feasible and environmentally superior.

Power-generating process of obtaining gas-energy carrier and reducer from coal

International Nuclear Information System (INIS)

Tleugabulov, S.; Duncheva, E.; Zubkevich, M.

1999-01-01

The manufacture of power-generating gas has the important economic value for Kazakhstan having large territory, raw and fuel resources especially power coal and clean coal wastes. The technology of reception of gas-energy carrier and reducer from power coal is developed. The basic product of technological process is heated reducing gas. Reducing potential of the gas is characterized by a volumetric share of components (CO+H 2 )-RC in relation to volume of whole mix of gases received with gasification of coal. The value of parameter RC is regulated by a degree of enrichment of air by oxygen r 0 , and the temperature - by the charge of a parity of endothermic reaction in the chamber of gas regeneration. The dependence of the gas structure and temperature on the degree of enrichment of air by oxygen is shown and the circuit of the gas generator is given. (author)

Comprehensive Report to Congress Clean Coal Technology Program: Clean power from integrated coal/ore reduction

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-10-01

This report describes a clean coal program in which an iron making technology is paired with combined cycle power generation to produce 3300 tons per day of hot metal and 195 MWe of electricity. The COREX technology consists of a metal-pyrolyzer connected to a reduction shaft, in which the reducing gas comes directly from coal pyrolysis. The offgas is utilized to fuel a combined cycle power plant.

Cogeneration Technology Alternatives Study (CTAS). Volume 6: Computer data. Part 1: Coal-fired nocogeneration process boiler, section B

Science.gov (United States)

Knightly, W. F.

1980-01-01

About fifty industrial processes from the largest energy consuming sectors were used as a basis for matching a similar number of energy conversion systems that are considered as candidate which can be made available by the 1985 to 2000 time period. The sectors considered included food, textiles, lumber, paper, chemicals, petroleum, glass, and primary metals. The energy conversion systems included steam and gas turbines, diesels, thermionics, stirling, closed cycle and steam injected gas turbines, and fuel cells. Fuels considered were coal, both coal and petroleum based residual and distillate liquid fuels, and low Btu gas obtained through the on site gasification of coal. Computer generated reports of the fuel consumption and savings, capital costs, economics and emissions of the cogeneration energy conversion systems (ECS's) heat and power matched to the individual industrial processes are presented. National fuel and emissions savings are also reported for each ECS assuming it alone is implemented. Two nocogeneration base cases are included: coal fired and residual fired process boilers.

Sustainable application of reciprocating gas engines operating on coal mine methane

Energy Technology Data Exchange (ETDEWEB)

Lee, J.; Teo, T. [Caterpillar China Investment Co., Beijing (China); Tnay, C.H. [Westrac Inc., Beijing (China)

2008-07-01

According to the World Coal Institute, coal provides 25 per cent of worldwide primary energy needs and generates 40 per cent of the world's electricity. China produces the largest amount of hard coal. The anthropogenic release of methane (CH{sub 4}) into the environment is a byproduct of the coal mining process. The global warming potential of this methane continues to draw attention around the world. In particular, China's government has recognized the need for environmental responsibility in the pursuit of greater power production. The Kyoto Protocol requires developed countries to reduce their greenhouse gas emissions and targets must be met within a five-year time frame between 2008 and 2012. Sequestering coal mine methane (CMM) as an alternative fuel for reciprocating gas engine generator sets is a mature and proven technology for greenhouse gas mitigation. Prior to commissioning CMM-fueled power systems, the methane gas composition must be evaluated. An integrated systems approach can then be used to develop a CMM-fueled power project. This paper discussed the sustainable application of reciprocating gas engines operating on coal mine methane. It discussed the Kyoto Protocol, clean development mechanism, and CMM as compared to other fuel sources. It was concluded that there is considerable opportunity for growth in the Asia-Pacific region for electric power applications using CMM. 4 refs., 12 figs.

Economic assessment of combined cycle gas turbines in Australia Some effects of microeconomic reform and technological change

International Nuclear Information System (INIS)

Naughten, Barry

2003-01-01

Australian electricity markets and natural gas markets are undergoing rapid reform. Choosing among electricity generation modes is a key issue. Such choices are affected by expectations about the future structure of these markets and future technologies, and how they affect costs and emissions. In the research reported in this paper, the MARKAL model of the Australian energy system is used to evaluate the competitive position of natural gas fired combined cycle gas turbines (CCGTs) in the energy sector as a whole. Competing in the sector are large-scale electricity generation technologies such as refurbished existing coal fired stations and advanced forms of coal fired generation. The modelling incorporates new data on electricity supply technologies and options

Liquid air fueled open–closed cycle Stirling engine

International Nuclear Information System (INIS)

Xu, Weiqing; Wang, Jia; Cai, Maolin; Shi, Yan

2015-01-01

Highlights: • Energy of liquid air is divided into cryogenic energy and expansion energy. • Open–closed cycle Stirling mechanism is employed to improve efficiency. • The Schmidt theory is modified to describe temperature variation in cold space. - Abstract: An unconventional Stirling engine is proposed and its theoretical analysis is performed. The engine belongs to a “cryogenic heat engine” that is fueled by cryogenic medium. Conventional “cryogenic heat engine” employs liquid air as pressure source, but disregards its heat-absorbing ability. Therefore, its efficiency can only be improved by increasing vapor pressure, accordingly increasing the demand on pressure resistance and sealing. In the proposed engine, the added Stirling mechanism helps achieve its high efficiency and simplicity by utilizing the heat-absorbing ability of liquid air. On one hand, based on Stirling mechanism, gas in the hot space absorbs heat from atmosphere when expanding; gas in the cold space is cooled down by liquid air when compressed. Taking atmosphere as heat source and liquid air as heat sink, a closed Stirling cycle is formed. On the other hand, an exhaust port is set in the hot space. When expanding in the hot space, the vaporized gas is discharged through the exhaust port. Thus, an open cycle is established. To model and analyze the system, the Schmidt theory is modified to describe temperature variation in the cold space, and irreversible characteristic of regenerator is incorporated in the thermodynamic model. The results obtained from the model show that under the same working pressure, the efficiency of the proposed engine is potentially higher than that of conventional ones and to achieve the same efficiency, the working pressure could be lower with the new mechanism. Its efficiency could be improved by reducing temperature difference between the regenerator and the cold/hot space, increasing the swept volume ratio, decreasing the liquid–gas ratio. To keep

Heat exchangers for high-temperature thermodynamic cycles

International Nuclear Information System (INIS)

Fraas, A.P.

1975-01-01

The special requirements of heat exchangers for high temperature thermodynamic cycles are outlined and discussed with particular emphasis on cost and thermal stress problems. Typical approaches that have been taken to a comprehensive solution intended to meet all of the many boundary conditions are then considered by examining seven typical designs including liquid-to-liquid heat exchangers for nuclear plants, a heater for a closed cycle gas turbine coupled to a fluidized bed coal combustion chamber, steam generators for nuclear plants, a fossil fuel-fired potassium boiler, and a potassium condenser-steam generator. (auth)

The effect of a tectonic stress field on coal and gas outbursts.

Science.gov (United States)

An, Fenghua; Cheng, Yuanping

2014-01-01

Coal and gas outbursts have always been a serious threat to the safe and efficient mining of coal resources. Ground stress (especially the tectonic stress) has a notable effect on the occurrence and distribution of outbursts in the field practice. A numerical model considering the effect of coal gas was established to analyze the outburst danger from the perspective of stress conditions. To evaluate the outburst tendency, the potential energy of yielded coal mass accumulated during an outburst initiation was studied. The results showed that the gas pressure and the strength reduction from the adsorbed gas aggravated the coal mass failure and the ground stress altered by tectonics would affect the plastic zone distribution. To demonstrate the outburst tendency, the ratio of potential energy for the outburst initiation and the energy consumption was used. Increase of coal gas and tectonic stress could enhance the potential energy accumulation ratio, meaning larger outburst tendency. The component of potential energy for outburst initiation indicated that the proportion of elastic energy was increased due to tectonic stress. The elastic energy increase is deduced as the cause for a greater outburst danger in a tectonic area from the perspective of stress conditions.

Survey report for fiscal 1998 on the conversion of the existing coal burning power plant to natural gas burning plant in Sakhalin State; 1998 nendo Saharinshu muke, kisetsu sekitandaki hatsuden no tennen gas daki tenkan chosa hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

The present survey is intended to discuss a modernization plan effective in reducing greenhouse effect gases for the two existing coal burning power plants in Sakhalin Island, Sakhalin State, the Federal Republic of Russia. The power plants are Sakhalinskaya Power Plant (GRES) and Yuzhno Sakalinskaya Power Plant (TETs-1). Simultaneously with converting the fuel from coal to natural gas, discussions are given on an optimal plan including introduction of the combined cycle and repowering technologies aiming at improving the thermal efficiency. Reduction in greenhouse effect gases, finance, and economy are evaluated. At the same time, verification will be given on environment improvement in Sakhalin Island, and influence on sustainable economic and social activation. The GRES modernization plan intends to build four combined cycle units each of 80 MW class to have nearly the same total capacity as the current total power generation facility capacity (315 MW). The TETs-1 modernization plan will convert the fuel for the existing boilers from coal to natural gas, modify one of the boilers whose construction is being suspended into gas burning boiler, and add gas turbines. (NEDO)

Fuel prices, emission standards, and generation costs for coal vs natural gas power plants.

Science.gov (United States)

Pratson, Lincoln F; Haerer, Drew; Patiño-Echeverri, Dalia

2013-05-07

Low natural gas prices and stricter, federal emission regulations are promoting a shift away from coal power plants and toward natural gas plants as the lowest-cost means of generating electricity in the United States. By estimating the cost of electricity generation (COE) for 304 coal and 358 natural gas plants, we show that the economic viability of 9% of current coal capacity is challenged by low natural gas prices, while another 56% would be challenged by the stricter emission regulations. Under the current regulations, coal plants would again become the dominant least-cost generation option should the ratio of average natural gas to coal prices (NG2CP) rise to 1.8 (it was 1.42 in February 2012). If the more stringent emission standards are enforced, however, natural gas plants would remain cost competitive with a majority of coal plants for NG2CPs up to 4.3.

Microalgae Production from Power Plant Flue Gas: Environmental Implications on a Life Cycle Basis

Energy Technology Data Exchange (ETDEWEB)

Kadam, K. L.

2001-06-22

Power-plant flue gas can serve as a source of CO{sub 2} for microalgae cultivation, and the algae can be cofired with coal. This life cycle assessment (LCA) compared the environmental impacts of electricity production via coal firing versus coal/algae cofiring. The LCA results demonstrated lower net values for the algae cofiring scenario for the following using the direct injection process (in which the flue gas is directly transported to the algae ponds): SOx, NOx, particulates, carbon dioxide, methane, and fossil energy consumption. Carbon monoxide, hydrocarbons emissions were statistically unchanged. Lower values for the algae cofiring scenario, when compared to the burning scenario, were observed for greenhouse potential and air acidification potential. However, impact assessment for depletion of natural resources and eutrophication potential showed much higher values. This LCA gives us an overall picture of impacts across different environmental boundaries, and hence, can help in the decision-making process for implementation of the algae scenario.

Reservoir characteristics of coal-shale sedimentary sequence in coal-bearing strata and their implications for the accumulation of unconventional gas

Science.gov (United States)

Wang, Yang; Zhu, Yanming; Liu, Yu; Chen, Shangbin

2018-04-01

Shale gas and coalbed methane (CBM) are both considered unconventional natural gas and are becoming increasingly important energy resources. In coal-bearing strata, coal and shale are vertically adjacent as coal and shale are continuously deposited. Research on the reservoir characteristics of coal-shale sedimentary sequences is important for CBM and coal-bearing shale gas exploration. In this study, a total of 71 samples were collected, including coal samples (total organic carbon (TOC) content >40%), carbonaceous shale samples (TOC content: 6%-10%), and shale samples (TOC content TOC content. Clay and quartz also have a great effect on the porosity of shale samples. According to the FE-SEM image technique, nanoscale pores in the organic matter of coal samples are much more developed compared with shale samples. For shales with low TOC, inorganic minerals provide more pores than organic matter. In addition, TOC content has a positive relationship with methane adsorption capacity, and the adsorption capacity of coal samples is more sensitive than the shale samples to temperature.

Thermodynamic design of natural gas liquefaction cycles for offshore application

Science.gov (United States)

Chang, Ho-Myung; Lim, Hye Su; Choe, Kun Hyung

2014-09-01

A thermodynamic study is carried out for natural gas liquefaction cycles applicable to offshore floating plants, as partial efforts of an ongoing governmental project in Korea. For offshore liquefaction, the most suitable cycle may be different from the on-land LNG processes under operation, because compactness and simple operation are important as well as thermodynamic efficiency. As a turbine-based cycle, closed Claude cycle is proposed to use NG (natural gas) itself as refrigerant. The optimal condition for NG Claude cycle is determined with a process simulator (Aspen HYSYS), and the results are compared with fully-developed C3-MR (propane pre-cooled mixed refrigerant) JT cycles and various N2 (nitrogen) Brayton cycles in terms of efficiency and compactness. The newly proposed NG Claude cycle could be a good candidate for offshore LNG processes.

Visual detection of gas shows from coal core and cuttings using liquid leak detector

Energy Technology Data Exchange (ETDEWEB)

Barker, C.E. [United States Geological Survey, Denver, CO (United States)

2006-09-15

Coal core descriptions are difficult to obtain, as they must be obtained immediately after the core is retrieved and before the core is closed in a canister. This paper described a method of marking gas shows on a core surface by coating the core with a water-based liquid leak detector and photographing the subsequent foam developed on the core surface while the core is still in the core tray. Coals from a borehole at the Yukon Flats Basin in Alaska and the Maverick Basin in Texas were used to illustrate the method. Drilling mud and debris were removed from the coal samples before the leak detector solution was applied onto the core surfaces. A white froth or dripping foam developed rapidly at gas shows on the sample surfaces. A hand-held lens and a binocular microscope were used to magnify the foaming action. It was noted that foaming was not continuous across the core surface, but was restricted to localized points along the surface. It was suggested that the localized point foaming may have resulted from the coring process. However, the same tendency toward point gas show across the sample surface was found in some hard, well-indurated samples that still had undisturbed bedding and other sedimentary structures. It was concluded that gas shows marked as separate foam centres may indicate a real condition of local permeability paths. Results suggested that the new gas show detection method could be used in core selection studies to reduce the costs of exploration programs. 6 refs., 4 figs.

No more coal-fired units

International Nuclear Information System (INIS)

Anon.

1997-01-01

According to Minister of the Environment Pekka Haavisto natural gas, bioenergy and renewables are the ways of responding to future base load power need. Greenhouse gas emissions using natural gas are around 60 % of those with coal. Increasing the share of generation accounted for by natural gas in the Nordic region is just as feasible in principle as elsewhere in Europe. A good proportion of new power stations elsewhere in the community are natural gas-fired. Vattenfall is planning a combined cycle station in the 700 - 900 MW range for Imatra, and Imatran Voima a 600 MW gas-fired unit for Inkoo. Replacing coal with natural gas is an essential part of efforts to stabile CO 2 emissions

Assessment of an atmospheric fluidized-bed coal-combustion gas-turbine cogeneration system for industrial application

Energy Technology Data Exchange (ETDEWEB)

Graves, R. L.; Holcomb, R. S.; Tallackson, J. R.

1979-10-01

This study was initiated to provide information on the future potential industrial market for a cogeneration system consisting of a fluidized-bed coal combustor coupled to a gas-turbine (Brayton cycle) power system that uses air as the working fluid. In assessing the potential applications for the system, the process heat energy consumption by industry is identified, with special detail included on the six most energy-intensive industries. The potential impact on the nation's oil and natural gas consumption that would result from wide-spread utilization of coal for process heat is also estimated. The fraction of industrial process heat that the system could feasibly satisfy from a thermodynamic viewpoint is estimated, and the performance (potential fuel efficiency and heat/power ratio) of the atmospheric fluidized-bed gas-turbine system is calculated. Also treated are several specific case studies of industries in which the system could be incorporated. Major parameters are specified, and flow sheets are derived for systems that would satisfy the heat and power requirements of the process or industry. The overall fuel utilization efficiency, thermal power rating, and potential number of installations are specified for these case studies. The findings of the study indicate that there is a sizable potential market for the system, with over 1000 possible installations disclosed after reviewing only 8 specific industries from 6 major Standard Industrial Classification (SIC) groups. The potential displacement of oil and gas by coal in process heating is shown to be about 1.60 m/sup 3//sec (870,000 bbl/d) of oil and 4590 m/sup 3//sec (14.0 billion ft/sup 3//d) of natural gas for all industries combined. Continued development of the fluidized-bed coal combustor and power system is recommended so that this potential may be at least partially realized.

Place of petroleum in the U. K. fuel market. [In relation to electricity, gas, and coal

Energy Technology Data Exchange (ETDEWEB)

Nicolaou, G B

1977-06-01

An attempt is made to study the interaction process that occurs between petroleum products and the remainder of the fuel market. Petroleum competes with electricity, gas, and coal as a source of fuel, and an assessment is made of the demand elasticities of its place in the fuel market. In the U.K. fuel market the question is to what extent petroleum is a substitute or complement to the others. Petroleum consumption constituted 25 percent in 1960 of the total fuel consumption and has grown constantly since. The extent to which it changes depends upon its close substitutes. Which out of gas, coal, and electricity is, in fact, the closest substitute for petroleum; is it sensitive to price or to other things. In order to attempt to answer these questions, two models are presented. The first presents a straightforward linear equation for the demand for petroleum due to a change in total fuel consumption. This is then used in Model 2, which is basically the Slutsky equation, to obtain the mean substitution effect between petroleum and coal, gas and electricity. This, then, measures the net substitution or complementarity between petroleum and the commodities mentioned. 11 references.

Combustion of coal gas fuels in a staged combustor

Science.gov (United States)

Rosfjord, T. J.; Mcvey, J. B.; Sederquist, R. A.; Schultz, D. F.

1982-01-01

Gaseous fuels produced from coal resources generally have heating values much lower than natural gas; the low heating value could result in unstable or inefficient combustion. Coal gas fuels may contain ammonia which if oxidized in an uncontrolled manner could result in unacceptable nitrogen oxide exhaust emission levels. Previous investigations indicate that staged, rich-lean combustion represents a desirable approach to achieve stable, efficient, low nitrogen oxide emission operation for coal-derived liquid fuels contaning up to 0.8-wt pct nitrogen. An experimental program was conducted to determine whether this fuel tolerance can be extended to include coal-derived gaseous fuels. The results of tests with three nitrogen-free fuels having heating values of 100, 250, and 350 Btu/scf and a 250 Btu/scf heating value doped to contain 0.7 pct ammonia are presented.

Analysis of gas migration patterns in fractured coal rocks under actual mining conditions

Directory of Open Access Journals (Sweden)

Gao Mingzhong

2017-01-01

Full Text Available Fracture fields in coal rocks are the main channels for gas seepage, migration, and extraction. The development, evolution, and spatial distribution of fractures in coal rocks directly affect the permeability of the coal rock as well as gas migration and flow. In this work, the Ji-15-14120 mining face at the No. 8 Coal Mine of Pingdingshan Tian’an Coal Mining Co. Ltd., Pingdingshan, China, was selected as the test site to develop a full-parameter fracture observation instrument and a dynamic fracture observation technique. The acquired video information of fractures in the walls of the boreholes was vectorized and converted to planarly expanded images on a computer-aided design platform. Based on the relative spatial distances between the openings of the boreholes, simultaneous planar images of isolated fractures in the walls of the boreholes along the mining direction were obtained from the boreholes located at various distances from the mining face. Using this information, a 3-D fracture network under mining conditions was established. The gas migration pattern was calculated using a COMSOL computation platform. The results showed that between 10 hours and 1 day the fracture network controlled the gas-flow, rather than the coal seam itself. After one day, the migration of gas was completely controlled by the fractures. The presence of fractures in the overlying rock enables the gas in coal seam to migrate more easily to the surrounding rocks or extraction tunnels situated relatively far away from the coal rock. These conclusions provide an important theoretical basis for gas extraction.

Relaxation and gas drainage boreholes for high performance longwall operations in low permeability coal seams

Energy Technology Data Exchange (ETDEWEB)

Imgrund, Thomas [DMT GmbH und Co. KG, Essen (Germany); Bauer, Frank [Hazemag und EPR GmbH, Duelmen (Germany). Mining

2013-06-15

With an increasing depth of cover, gas emission control and gas outbursts prevention has become an increasingly important issue in coal mining. Deep multi-seam mining often requires operation in an environment characterised by a high gas content and gas pressure. Control of gas related risks has to be realised during heading and close to the longwall by proper risk assessment and flexible drilling schemes. These cover exploration and relaxation drilling, in-seam drilling for pre-drainage and cross measure drilling for drainage of roof and the floor gas emissions. DMT provides comprehensive solutions based on a scientific background. These solutions are engineered considering their technical feasibility. Hazemag Mining offers a large number of complete machinery including tools systems for the implementation of those solutions. (orig.)

Life cycle greenhouse gas emissions from U.S. liquefied natural gas exports: implications for end uses.

Science.gov (United States)

Abrahams, Leslie S; Samaras, Constantine; Griffin, W Michael; Matthews, H Scott

2015-03-03

This study analyzes how incremental U.S. liquefied natural gas (LNG) exports affect global greenhouse gas (GHG) emissions. We find that exported U.S. LNG has mean precombustion emissions of 37 g CO2-equiv/MJ when regasified in Europe and Asia. Shipping emissions of LNG exported from U.S. ports to Asian and European markets account for only 3.5-5.5% of precombustion life cycle emissions, hence shipping distance is not a major driver of GHGs. A scenario-based analysis addressing how potential end uses (electricity and industrial heating) and displacement of existing fuels (coal and Russian natural gas) affect GHG emissions shows the mean emissions for electricity generation using U.S. exported LNG were 655 g CO2-equiv/kWh (with a 90% confidence interval of 562-770), an 11% increase over U.S. natural gas electricity generation. Mean emissions from industrial heating were 104 g CO2-equiv/MJ (90% CI: 87-123). By displacing coal, LNG saves 550 g CO2-equiv per kWh of electricity and 20 g per MJ of heat. LNG saves GHGs under upstream fugitive emissions rates up to 9% and 5% for electricity and heating, respectively. GHG reductions were found if Russian pipeline natural gas was displaced for electricity and heating use regardless of GWP, as long as U.S. fugitive emission rates remain below the estimated 5-7% rate of Russian gas. However, from a country specific carbon accounting perspective, there is an imbalance in accrued social costs and benefits. Assuming a mean social cost of carbon of $49/metric ton, mean global savings from U.S. LNG displacement of coal for electricity generation are $1.50 per thousand cubic feet (Mcf) of gaseous natural gas exported as LNG ($.028/kWh). Conversely, the U.S. carbon cost of exporting the LNG is $1.80/Mcf ($.013/kWh), or $0.50-$5.50/Mcf across the range of potential discount rates. This spatial shift in embodied carbon emissions is important to consider in national interest estimates for LNG exports.

Biological conversion of coal synthesis gas to methane

Energy Technology Data Exchange (ETDEWEB)

Barik, S; Corder, R E; Clausen, E C; Gaddy, J L

1987-09-01

High temperatures and pressures are required, and therefore, high costs incurred during catalytic upgrading of coal synthesis gas to methane. Thus, the feasibility of biological reactions in converting synthesis gas to methane has been demonstrated in mixed and pure cultures. Complete conversion has been achieved in 2 hours with a mixed culture, and 45 minutes to 1.5 hours in pure cultures of P. productus and Methanothrix sp.. Typical sulfur levels involved during the process are found not to inhibit the bacteria and so sulfur does not have to be removed prior to biomethanation. Preliminary economic analyses indicate that coal gas may be biologically methanated for 50-60 cents/million Btu. Further studies with pure culture bacteria and increased pressure are expected to enhance biomethanation economics.

Critical evaluation of high-temperature gas-cooled reactors applicable to coal conversion

International Nuclear Information System (INIS)

Spiewak, I.; Jones, J.E. Jr.; Rittenhouse, P.L.; DeStefano, J.R.; Delene, J.G.

1975-12-01

A critical review is presented of the technology and costs of very high-temperature gas-cooled reactors (VHTRs) applicable to nuclear coal conversion. Coal conversion processes suitable for coupling to reactors are described. Vendor concepts of the VHTR are summarized. The materials requirements as a function of process temperature in the range 1400 to 2000 0 F are analyzed. Components, environmental and safety factors, economics and nuclear fuel cycles are reviewed. It is concluded that process heat supply in the range 1400 to 1500 0 F could be developed with a high degree of assurance. Process heat at 1600 0 F would require considerably more materials development. While temperatures up to 2000 0 F appear to be attainable, considerably more research and risk were involved. A demonstration plant would be required as a step in the commercialization of the VHTR

Gas Concentration Prediction Based on the Measured Data of a Coal Mine Rescue Robot

Directory of Open Access Journals (Sweden)

Xiliang Ma

2016-01-01

Full Text Available The coal mine environment is complex and dangerous after gas accident; then a timely and effective rescue and relief work is necessary. Hence prediction of gas concentration in front of coal mine rescue robot is an important significance to ensure that the coal mine rescue robot carries out the exploration and search and rescue mission. In this paper, a gray neural network is proposed to predict the gas concentration 10 meters in front of the coal mine rescue robot based on the gas concentration, temperature, and wind speed of the current position and 1 meter in front. Subsequently the quantum genetic algorithm optimization gray neural network parameters of the gas concentration prediction method are proposed to get more accurate prediction of the gas concentration in the roadway. Experimental results show that a gray neural network optimized by the quantum genetic algorithm is more accurate for predicting the gas concentration. The overall prediction error is 9.12%, and the largest forecasting error is 11.36%; compared with gray neural network, the gas concentration prediction error increases by 55.23%. This means that the proposed method can better allow the coal mine rescue robot to accurately predict the gas concentration in the coal mine roadway.

Greenhouse gas emission factor development for coal-fired power plants in Korea

International Nuclear Information System (INIS)

Jeon, Eui-Chan; Myeong, Soojeong; Sa, Jae-Whan; Kim, Jinsu; Jeong, Jae-Hak

2010-01-01

Accurate estimation of greenhouse gas emissions is essential for developing an appropriate strategy to mitigate global warming. This study examined the characteristics of greenhouse gas emission from power plants, a major greenhouse gas source in Korea. The power plants examined use bituminous coal, anthracite, and sub-bituminous coal as fuel. The CO 2 concentration from power plants was measured using GC-FID with methanizer. The amount of carbon, hydrogen, and calorific values in the input fuel was measured using an elemental analyzer and calorimeter. For fuel analysis, CO 2 emission factors for anthracite, bituminous coal, and sub-bituminous coal were 108.9, 88.4, and 97.9 Mg/kJ, respectively. The emission factors developed in this study were compared with those for IPCC. The results showed that CO 2 emission was 10.8% higher for anthracite, 5.5% lower for bituminous coal, and 1.9% higher for sub-bituminous coal than the IPCC figures.

Removal of mercury from coal-combustion flue gas using regenerable sorbents

Energy Technology Data Exchange (ETDEWEB)

Turchi, C S; Albiston, J; Broderick, T E; Stewart, R M

1999-07-01

The US EPA estimates that coal-fired power plants constitute the largest anthropogenic source of mercury emissions in the US. The Agency has contemplated emission regulations for power plants, but the large gas-flow rates and low mercury concentrations involved have made current treatment options prohibitively expensive. ADA Technologies, Inc. (Englewood, Colorado), in conjunction with the US DOE, is developing regenerable sorbents for the removal and recovery of mercury from flue gas. These sorbents are based on the ability of noble metals to amalgamate mercury at typical flue-gas temperatures and release mercury at higher temperatures. The process allows for recovery of mercury with minimal volumes of secondary wastes and no impact on fly ash quality. In 1997 and 1998, ADA tested a 20-cfm sorbent unit at CONSOL Inc.'s coal-combustion test facility in Library, PA. Results from the 1997 tests indicated that the sorbent can remove elemental and oxidized mercury and can be regenerated without loss of capacity. Design changes were implemented in 1998 to enhance the thermal efficiency of the process and to recover the mercury in a stable form. Testing during autumn, 1998 demonstrated 60% to 90% removal efficiency of mercury from a variety of different coals. However, contradictory removal results were obtained at the end of the test period. Subsequent laboratory analyses indicated that the sorbent had lost over half its capacity for mercury due to a decrease in available sites for mercury sorption. The presence of sulfur compounds on the sorbent suggests that thermal cycling may have condensed acid gases on the sorbent leading to deterioration of the active sorption sites. The regeneration time/temperature profile has been altered to minimize this potential in the upcoming power plant tests.

Optimum gas turbine cycle for combined cycle power plant

International Nuclear Information System (INIS)

Polyzakis, A.L.; Koroneos, C.; Xydis, G.

2008-01-01

The gas turbine based power plant is characterized by its relatively low capital cost compared with the steam power plant. It has environmental advantages and short construction lead time. However, conventional industrial engines have lower efficiencies, especially at part load. One of the technologies adopted nowadays for efficiency improvement is the 'combined cycle'. The combined cycle technology is now well established and offers superior efficiency to any of the competing gas turbine based systems that are likely to be available in the medium term for large scale power generation applications. This paper has as objective the optimization of a combined cycle power plant describing and comparing four different gas turbine cycles: simple cycle, intercooled cycle, reheated cycle and intercooled and reheated cycle. The proposed combined cycle plant would produce 300 MW of power (200 MW from the gas turbine and 100 MW from the steam turbine). The results showed that the reheated gas turbine is the most desirable overall, mainly because of its high turbine exhaust gas temperature and resulting high thermal efficiency of the bottoming steam cycle. The optimal gas turbine (GT) cycle will lead to a more efficient combined cycle power plant (CCPP), and this will result in great savings. The initial approach adopted is to investigate independently the four theoretically possible configurations of the gas plant. On the basis of combining these with a single pressure Rankine cycle, the optimum gas scheme is found. Once the gas turbine is selected, the next step is to investigate the impact of the steam cycle design and parameters on the overall performance of the plant, in order to choose the combined cycle offering the best fit with the objectives of the work as depicted above. Each alterative cycle was studied, aiming to find the best option from the standpoint of overall efficiency, installation and operational costs, maintainability and reliability for a combined power

Emission of CO2 Gas and Radioactive Pollutant from Coal Fired Power Plant

International Nuclear Information System (INIS)

Ida, N.Finahari; Djati-HS; Heni-Susiati

2006-01-01

Energy utilization for power plant in Indonesia is still depending on burning fossil fuel such as coal, oil and gaseous fuel. The direct burning of coal produces CO 2 gas that can cause air pollution, and radioactive pollutant that can increase natural radioactive dosage. Natural radionuclide contained in coal is in the form of kalium, uranium, thorium and their decay products. The amount of CO 2 gas emission produced by coal fired power plant can be reduced by equipping the plant with waste-gas treatment facility. At this facility, CO 2 gas is reacted with calcium hydroxide producing calcium carbonate. Calcium carbonate then can be used as basic material in food, pharmaceutical and construction industries. The alternative method to reduce impact of air pollution is by replacing coal fuel with nuclear fuel or new and renewable fuel. (author)

Improving fuel cycle design and safety characteristics of a gas cooled fast reactor

NARCIS (Netherlands)

van Rooijen, W.F.G.

2006-01-01

This research concerns the fuel cycle and safety aspects of a Gas Cooled Fast Reactor, one of the so-called "Generation IV" nuclear reactor designs. The Generation IV Gas Cooled Fast Reactor uses helium as coolant at high temperature. The goal of the GCFR is to obtain a "closed nuclear fuel cycle",

Production of synthesis gas and methane via coal gasification utilizing nuclear heat

International Nuclear Information System (INIS)

van Heek, K.H.; Juentgen, H.

1982-01-01

The steam gasificaton of coal requires a large amount of energy for endothermic gasification, as well as for production and heating of the steam and for electricity generation. In hydrogasification processes, heat is required primarily for the production of hydrogen and for preheating the reactants. Current developments in nuclear energy enable a gas cooled high temperature nuclear reactor (HTR) to be the energy source, the heat produced being withdrawn from the system by means of a helium loop. There is a prospect of converting coal, in optimal yield, into a commercial gas by employing the process heat from a gas-cooled HTR. The advantages of this process are: (1) conservation of coal reserves via more efficient gas production; (2) because of this coal conservation, there are lower emissions, especially of CO 2 , but also of dust, SO 2 , NO/sub x/, and other harmful substances; (3) process engineering advantages, such as omission of an oxygen plant and reduction in the number of gas scrubbers; (4) lower gas manufacturing costs compared to conventional processes. The main problems involved in using nuclear energy for the industrial gasification of coal are: (1) development of HTRs with helium outlet temperatures of at least 950 0 C; (2) heat transfer from the core of the reactor to the gas generator, methane reforming oven, or heater for the hydrogenation gas; (3) development of a suitable allothermal gas generator for the steam gasification; and (4) development of a helium-heated methane reforming oven and adaption of the hydrogasification process for operation in combination with the reactor. In summary, processes for gasifying coal that employ heat from an HTR have good economic and technical prospects of being realized in the future. However, time will be required for research and development before industrial application can take place. 23 figures, 4 tables. (DP)

Update on the REIPPPP, clean coal, nuclear, natural gas

CSIR Research Space (South Africa)

Milazi, Dominic

2015-12-01

Full Text Available , clean coal, nuclear, natural gas The Sustainable Energy Resource Handbook Volume 6 Dominic Milazi, Dr Tobias Bischof-Niemz, Abstract Since its release in 2011, the Integrated Resource Plan (IRP 2010-2030), or IRP 2010, has been the authoritative... text setting out South Africa’s electricity plan over the next 20 years. The document indicates timelines on the roll out of key supply side options such as renewable energy, the nuclear, natural gas and coal build programmes, as well as peaking...

Sorption characteristic of coal as regards of gas mixtures emitted in the process of the self-heating of coal

Directory of Open Access Journals (Sweden)

Wojtacha-Rychter Karolina

2017-01-01

Full Text Available One of the most challenging tasks in the coal mining sector is the detection of endogenous fire risks. Under field conditions, the distance between the points where samples for the analyses are collected and the actual place where coal self-heating takes place may be quite remote. Coal is a natural sorbent with a diverse character of pore structures which are surrounded by fractures and cleavage planes constituting ideal spaces for the flow and adsorption of gases. The gases (methane, ethane, ethylene, propane, propylene, acetylene, carbon dioxide, carbon monoxide, hydrogen released from the source of fire migrate through the seam and may be subject to adsorption, or they may cause the desorption of gases accumulated in coal. Therefore, the values of reference sample concentrations may be overstated or understated, respectively. The objective of this experimental study was to investigate the adsorption phenomena accompanying the flow of a multi-component gas mixture through a coal bed which may occur in situ. The research was conducted by means of a method based on a series of calorimetric/chromatographic measurements taken to determine the amount of gases released during coal heating at various temperatures under laboratory conditions. Based on the results obtained in the course of the experiments, it was concluded that the amount of gas adsorbed in the seam depends on the type of coal and the gas. Within the multi-component gas mixture, hydrocarbons demonstrated the largest sorption capacity, especially as concerns propylene.

Stress and Damage Induced Gas Flow Pattern and Permeability Variation of Coal from Songzao Coalfield in Southwest China

Directory of Open Access Journals (Sweden)

Minghui Li

2016-05-01

Full Text Available The permeability of coal is a critical parameter in estimating the performance of coal reservoirs. Darcy’s law describes the flow pattern that the permeability has a linear relationship with the flow velocity. However, the stress induced deformation and damage can significantly influence the gas flow pattern and permeability of coal. Coals from Songzao coalfield in Chongqing, southwest China were collected for the study. The gas flow velocities under different injection gas pressures and effective stresses in the intact coal and damaged coal were tested using helium, incorporating the role of gas flow pattern on the permeability of coal. The relationships between the flow velocity and square of gas pressure gradient were discussed, which can help us to investigate the transformation conditions of gas linear flow and gas nonlinear flow in the coal. The results showed that the gas flow in the intact coal existed pseudo-initial flow rate under low effective stress. The low-velocity non-Darcy gas flow gradually occurred and the start-up pressure gradient increased in the coal as the effective stress increased. The gas flow rate in the damaged coal increased nonlinearly as the square of pressure gradient increased under low effective stress. The instability of gas flow caused by high ratio of injection gas pressure over effective stress in the damaged coal contributed to the increase of the gas flow rate. As the effective stress increased, the increase of gas flow rate in coal turned to be linear. The mechanisms of the phenomena were explored according to the experimental results. The permeability of coal was corrected based on the relationships between the flow velocity and square of gas pressure gradient, which showed advantages in accurately estimating the performance of coal reservoirs.

Gas Hydrates of Coal Layers as a Methane Source in the Atmosphere and Mine Working

Science.gov (United States)

Dyrdin, Valery; Shepeleva, Sofya; Kim, Tatiana

2017-11-01

Living conditions of gas hydrates of a methane in a coal matrix as one of possible forms of finding of molecules of a methane in coal layers are considered. However, gas hydrates are formed not in all mineral coals even under the thermobaric conditions corresponding to their equilibrium state as the minimum humidity and the corresponding pore width are necessary for each brand of coal for formation of gas hydrate. It is shown that it depends on electric electrical dipole moment of a macromolecule of coal. Coals of brands K, D, Zh were considered. The electric field created by the surface of coal does not allow molecules of water to carry out threedimensional driving, and they keep on an internal surface of a time. By means of theoretical model operation a dipole - dipole interaction of molecules of water with the steam surface of coal values of energy of fiber interaction for various functional groups located in coal "fringe" which size for the first and second layers does not allow molecules of water to participate in formation of gas hydrates are received. For coals of brands K, Zh, D, considering distribution of a time on radiuses, the percent of moisture, which cannot share in education solid coal of gas solutions, is calculated.

A New Tree-Type Fracturing Method for Stimulating Coal Seam Gas Reservoirs

Directory of Open Access Journals (Sweden)

Qian Li

2017-09-01

Full Text Available Hydraulic fracturing is used widely to stimulate coalbed methane production in coal mines. However, some factors associated with conventional hydraulic fracturing, such as the simple morphology of the fractures it generates and inhomogeneous stress relief, limit its scope of application in coal mines. These problems mean that gas extraction efficiency is low. Conventional fracturing may leave hidden pockets of gas, which will be safety hazards for subsequent coal mining operations. Based on a new drilling technique applicable to drilling boreholes in coal seams, this paper proposes a tree-type fracturing technique for stimulating reservoir volumes. Tree-type fracturing simulation experiments using a large-scale triaxial testing apparatus were conducted in the laboratory. In contrast to the single hole drilled for conventional hydraulic fracturing, the tree-type sub-boreholes induce radial and tangential fractures that form complex fracture networks. These fracture networks can eliminate the “blank area” that may host dangerous gas pockets. Gas seepage in tree-type fractures was analyzed, and gas seepage tests after tree-type fracturing showed that permeability was greatly enhanced. The equipment developed for tree-type fracturing was tested in the Fengchun underground coal mine in China. After implementing tree-type fracturing, the gas extraction rate was around 2.3 times greater than that for traditional fracturing, and the extraction rate remained high for a long time during a 30-day test. This shortened the gas drainage time and improved gas extraction efficiency.

Gas Emission Prediction Model of Coal Mine Based on CSBP Algorithm

Directory of Open Access Journals (Sweden)

Xiong Yan

2016-01-01

Full Text Available In view of the nonlinear characteristics of gas emission in a coal working face, a prediction method is proposed based on cuckoo search algorithm optimized BP neural network (CSBP. In the CSBP algorithm, the cuckoo search is adopted to optimize weight and threshold parameters of BP network, and obtains the global optimal solutions. Furthermore, the twelve main affecting factors of the gas emission in the coal working face are taken as input vectors of CSBP algorithm, the gas emission is acted as output vector, and then the prediction model of BP neural network with optimal parameters is established. The results show that the CSBP algorithm has batter generalization ability and higher prediction accuracy, and can be utilized effectively in the prediction of coal mine gas emission.

Wabash River Coal Gasification Combined Cycle Repowering Project: Clean Coal Technology Program

International Nuclear Information System (INIS)

1993-05-01

The proposed project would result in a combined-cycle power plant with lower emissions and higher efficiency than most existing coal-fired power plants of comparable size. The net plant heat rate (energy content of the fuel input per useable electrical generation output; i.e., Btu/kilowatt hour) for the new repowered unit would be a 21% improvement over the existing unit, while reducing SO 2 emissions by greater than 90% and limiting NO x emissions by greater than 85% over that produced by conventional coal-fired boilers. The technology, which relies on gasified coal, is capable of producing as much as 25% more electricity from a given amount of coal than today's conventional coal-burning methods. Besides having the positive environmental benefit of producing less pollutants per unit of power generated, the higher overall efficiency of the proposed CGCC project encourages greater utilization to meet base load requirements in order to realize the associated economic benefits. This greater utilization (i.e., increased capacity factor) of a cleaner operating plant has global environmental benefits in that it is likely that such power would replace power currently being produced by less efficient plants emitting a greater volume of pollutants per unit of power generated

Effect of temperature on the permeability of gas adsorbed coal under triaxial stress conditions

Science.gov (United States)

Li, Xiangchen; Yan, Xiaopeng; Kang, Yili

2018-04-01

The combined effects of gas sorption, stress and temperature play a significant role in the changing behavior of gas permeability in coal seams. The effect of temperature on nitrogen and methane permeability of naturally fractured coal is investigated. Coal permeability, P-wave velocity and axial strain were simultaneously measured under two effective stresses and six different temperatures. The results showed that the behavior of nitrogen and methane permeability presented nonmonotonic changes with increasing temperature. The variation in the P-wave velocity and axial strain showed a good correspondence with coal permeability. A higher effective stress limited the bigger deformation and caused the small change in permeability. Methane adsorption and desorption significantly influence the mechanical properties of coal and play an important role in the variations in coal permeability. The result of coal permeability during a complete stress-strain process showed that the variation in permeability is determined by the evolution of the internal structure. The increase in the temperature of the gas saturated coal causes the complex interaction between matrix swelling, matrix shrinkage and micro-fracture generation, which leads to the complex changes in coal structure and permeability. These results are helpful to understand the gas transport mechanism for exploiting coal methane by heat injection.

CFD analysis of NOx reduction by domestic natural gas added to coal combustion

Energy Technology Data Exchange (ETDEWEB)

Bar-Ziv, E.; Yasur, Y.; Chudnovsky, B. [Ben-Gurion University of the Negev, Beer-Sheva (Israel). Dept. of Mechanical Engineering and Inst. for Applied Research

2004-07-01

To date, Israel's electrical energy has been based only on imported fuels. However, with the recently discovered natural gas in the Ashqulon shores, Israel can examine the benefits to its energy resources, environment, and economy of blending its domestic natural gas with imported coal. As for using natural gas, the proposal is to burn it in existing IEC coal-fired boilers in order to significantly reduce NOx emission by reburning. An important aspect is to provide retrofitting in existing IEC boilers by replacing a fraction of the coal by natural gas. This would allow the purchase of coal with a wide range of parameters, which is less expensive. Hence, mixed gas-coal burning would benefit Israel. The authors have made numerical simulations in order to study the optimal conditions of operation and evaluate the economic as well as environmental benefits. Indeed, extensive simulations have shown that there is a significant reduction of NOx emission, as expected, with the addition of relatively small amounts of natural gas. Experiments will now be carried out in a test facility that will provide accurate physicochemical properties of the mixed fuel for more reliable simulations. 19 refs., 6 figs., 1 tab.

Central Arkansas Energy Project. Coal to medium-Btu gas

Science.gov (United States)

1982-05-01

The Central Arkansas Energy Project has as its objective the conversion of coal in a central location to a more readily usable energy source, medium Btu gas (MBG), for use at dispersed locations as fuel for power production and steam generation, or as a feedstock for chemical processing. The project elements consist of a gasification facility to produce MBG from coal, a pipeline to supply the MBG to the dispersed sites. The end of line users investigated were the repowering or refueling of an existing Arkansas Power and Light Co. Generating station, an ammonia plant, and a combined cycle cogeneration facility for the production of steam and electricity. Preliminary design of the gasification plant including process engineering design bases, process flow diagrams, utility requirements, system description, project engineering design, equipment specifications, plot plan and section plot plans, preliminary piping and instrument diagrams, and facilities requirements. Financial analyses and sensitivities are determined. Design and construction schedules and manpower loadings are developed. It is concluded that the project is technically feasible, but the financial soundness is difficult to project due to uncertainty in energy markets of competing fuels.

Clean coal technology challenges for China

Energy Technology Data Exchange (ETDEWEB)

Mao, J. [Tsinghua University, Beijing (China). Dept. of Thermal Engineering

2001-01-01

China is rich in coal reserves and also the largest coal producer and consumer in the world. Coal constitutes over 70% of the total energy consumption, some 86% of coal production is burned directly, which causes serious air pollution problems. However, based on China's specific energy structure, coal utilisation will remain the dominant means of energy usage and clean coal technology must be the way forward if the environmental problems are to be resolved. This article discusses China's Clean Coal Technology Program, its implementation, including the clean coal technologies being developed and introduced, with reference to the key R & D institutes for each of the coal-using sectors. The article is an edited version of the 2000 Robens Coal Science Lecture, delivered in London in October 2000. The China Coal Technology Program for the 9th Five-Year Plan (1996-2000) was approved in 1997. The technologies included in the Program considered in this article are in: coal washing and grading, coal briquette, coal water slurry; circulating fluidised bed technology; pressurised fluidised bed combined cycle; integrated gasification combined cycle; coal gasification, coal liquefaction and flue gas desulfurisation. 4 tabs.

Can Switching from Coal to Shale Gas Bring Net Carbon Reductions to China?

Science.gov (United States)

Qin, Yue; Edwards, Ryan; Tong, Fan; Mauzerall, Denise L

2017-03-07

To increase energy security and reduce emissions of air pollutants and CO 2 from coal use, China is attempting to duplicate the rapid development of shale gas that has taken place in the United States. This work builds a framework to estimate the lifecycle greenhouse gas (GHG) emissions from China's shale gas system and compares them with GHG emissions from coal used in the power, residential, and industrial sectors. We find the mean lifecycle carbon footprint of shale gas is about 30-50% lower than that of coal in all sectors under both 20 year and 100 year global warming potentials (GWP 20 and GWP 100 ). However, primarily due to large uncertainties in methane leakage, the upper bound estimate of the lifecycle carbon footprint of shale gas in China could be approximately 15-60% higher than that of coal across sectors under GWP 20 . To ensure net GHG emission reductions when switching from coal to shale gas, we estimate the breakeven methane leakage rates to be approximately 6.0%, 7.7%, and 4.2% in the power, residential, and industrial sectors, respectively, under GWP 20 . We find shale gas in China has a good chance of delivering air quality and climate cobenefits, particularly when used in the residential sector, with proper methane leakage control.

ECONOMICS AND FEASIBILITY OF RANKINE CYCLE IMPROVEMENTS FOR COAL FIRED POWER PLANTS

Energy Technology Data Exchange (ETDEWEB)

Richard E. Waryasz; Gregory N. Liljedahl

2004-09-08

ALSTOM Power Inc.'s Power Plant Laboratories (ALSTOM) has teamed with the U.S. Department of Energy National Energy Technology Laboratory (DOE NETL), American Electric Company (AEP) and Parsons Energy and Chemical Group to conduct a comprehensive study evaluating coal fired steam power plants, known as Rankine Cycles, equipped with three different combustion systems: Pulverized Coal (PC), Circulating Fluidized Bed (CFB), and Circulating Moving Bed (CMB{trademark}). Five steam cycles utilizing a wide range of steam conditions were used with these combustion systems. The motivation for this study was to establish through engineering analysis, the most cost-effective performance potential available through improvement in the Rankine Cycle steam conditions and combustion systems while at the same time ensuring that the most stringent emission performance based on CURC (Coal Utilization Research Council) 2010 targets are met: > 98% sulfur removal; < 0.05 lbm/MM-Btu NO{sub x}; < 0.01 lbm/MM-Btu Particulate Matter; and > 90% Hg removal. The final report discusses the results of a coal fired steam power plant project, which is comprised of two parts. The main part of the study is the analysis of ten (10) Greenfield steam power plants employing three different coal combustion technologies: Pulverized Coal (PC), Circulating Fluidized Bed (CFB), and Circulating Moving Bed (CMB{trademark}) integrated with five different steam cycles. The study explores the technical feasibility, thermal performance, environmental performance, and economic viability of ten power plants that could be deployed currently, in the near, intermediate, and long-term time frame. For the five steam cycles, main steam temperatures vary from 1,000 F to 1,292 F and pressures from 2,400 psi to 5,075 psi. Reheat steam temperatures vary from 1,000 F to 1,328 F. The number of feedwater heaters varies from 7 to 9 and the associated feedwater temperature varies from 500 F to 626 F. The main part of the

Coal yearbook 1993

International Nuclear Information System (INIS)

Anon.

1993-01-01

This book is the first coal yearbook published by ATIC (France). In a first chapter, economical context of coal worldwide market is analyzed: comparative evaluations on coal exports and imports, coal industry, prices, production in USA, Australia, South Africa, China, former USSR, Poland, Colombia, Venezuela and Indonesia are given. The second chapter describes the french energy context: national coal production, imports, sectorial analysis, maritime transport. The third chapter describes briefly the technologies of clean coal and energy saving developed by Charbonnages de France: fossil-fuel power plants with combined cycles and cogeneration, fluidized beds for the recovery of coal residues, recycling of agricultural wastes (sugar cane wastes) in thermal power plant, coal desulfurization for air pollution abatement. In the last chapter, statistical data on coal, natural gas and crude oil are offered: world production, world imports, world exports, french imports, deliveries to France, coal balance, french consumption of primary energy, power generation by fuel type

To extract gas of the coal

International Nuclear Information System (INIS)

Carta Petrolera

2001-01-01

The paper analyzes the characteristics and advantages of extracting gas of the coal, idea that from previous years Colombia wanted to develop, and owing to the association contract Rio Rancheria; Colombia decided to carry out it using modern technologies used today in day in the international environment

Current developments on the coal and gas markets and their retroactive effects on the Merit Order

International Nuclear Information System (INIS)

Hecking, Harald; Cam, Eren; Schoenfisch, Max; Schulte, Simon

2017-01-01

Coal and gas continue to play a significant role in the European power generation system, especially in Germany. According to the AG energy balances, the share of hard coal in German gross electricity generation in 2016 was 17.2% and natural gas 12.4%. In addition to the CO 2 price, the prices for steam coal and natural gas are a key factor in determining which gas or coal power station is in Merit Order and whether it comes to a fuel switch. Declining gas prices have been rising sharply since the middle of 2016, and the volatile prices for steam coal have been rising. This article discusses the developments and factors responsible for these developments, which could be expected in the near future, and the implications for the gas-coal spread in the electricity market. [de

Closed Brayton cycle power conversion systems for nuclear reactors :

Energy Technology Data Exchange (ETDEWEB)

Wright, Steven A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lipinski, Ronald J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Vernon, Milton E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sanchez, Travis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2006-04-01

This report describes the results of a Sandia National Laboratories internally funded research program to study the coupling of nuclear reactors to gas dynamic Brayton power conversion systems. The research focused on developing integrated dynamic system models, fabricating a 10-30 kWe closed loop Brayton cycle, and validating these models by operating the Brayton test-loop. The work tasks were performed in three major areas. First, the system equations and dynamic models for reactors and Closed Brayton Cycle (CBC) systems were developed and implemented in SIMULINKTM. Within this effort, both steady state and dynamic system models for all the components (turbines, compressors, reactors, ducting, alternators, heat exchangers, and space based radiators) were developed and assembled into complete systems for gas cooled reactors, liquid metal reactors, and electrically heated simulators. Various control modules that use proportional-integral-differential (PID) feedback loops for the reactor and the power-conversion shaft speed were also developed and implemented. The simulation code is called RPCSIM (Reactor Power and Control Simulator). In the second task an open cycle commercially available Capstone C30 micro-turbine power generator was modified to provide a small inexpensive closed Brayton cycle test loop called the Sandia Brayton test-Loop (SBL-30). The Capstone gas-turbine unit housing was modified to permit the attachment of an electrical heater and a water cooled chiller to form a closed loop. The Capstone turbine, compressor, and alternator were used without modification. The Capstone systems nominal operating point is 1150 K turbine inlet temperature at 96,000 rpm. The annular recuperator and portions of the Capstone control system (inverter) and starter system also were reused. The rotational speed of the turbo-machinery is controlled by adjusting the alternator load by using the electrical grid as the load bank. The SBL-30 test loop was operated at

Non-mine technology of hydrocarbon resources production at complex development of gas and coal deposits

International Nuclear Information System (INIS)

Saginov, A.S.; Adilov, K.N.; Akhmetbekov, Sh.U.

1997-01-01

Non-mine technology of coal gas seams exploitation is new geological technological method of complex exploitation of coal gas deposits. The method allows sequentially to extract hydrocarbon resources in technological aggregative-mobile condensed states. According to natural methane content in seams the technology includes: methane extraction from sorption volume where it is bounded up with coal; gas output intensification of coal is due to structural changes of substance at the cost of physico-chemical treatment of seam; increase of seam permeability by the methods of active physical and physico-chemical actions on coal seam (hydro-uncovering, pneumatic hydro action etc.). Pilot testing shows efficiency of well mastering with help of depth pumps. In this case works of action of pumping out of operating liquid and gas extraction from coal seam are integrated

Feasibility of Ericsson type isothermal expansion/compression gas turbine cycle for nuclear energy use

International Nuclear Information System (INIS)

Shimizu, Akihiko

2007-01-01

A gas turbine with potential demand for the next generation nuclear energy use such as HTGR power plants, a gas cooled FBR, a gas cooled nuclear fusion reactor uses helium as working gas and with a closed cycle. Materials constituting a cycle must be set lower than allowable temperature in terms of mechanical strength and radioactivity containment performance and so expansion inlet temperature is remarkably limited. For thermal efficiency improvement, isothermal expansion/isothermal compression Ericsson type gas turbine cycle should be developed using wet surface of an expansion/compressor casing and a duct between stators without depending on an outside heat exchanger performing multistage re-heat/multistage intermediate cooling. Feasibility of an Ericsson cycle in comparison with a Brayton cycle and multi-stage compression/expansion cycle was studied and technologies to be developed were clarified. (author)

Fast and safe gas detection from underground coal fire by drone fly over.

Science.gov (United States)

Dunnington, Lucila; Nakagawa, Masami

2017-10-01

Underground coal fires start naturally or as a result of human activities. Besides burning away the important non-renewable energy resource and causing financial losses, burning coal seams emit carbon dioxide, carbon monoxide, sulfur oxide and methane, and is a leading cause of smog, acid rain, global warming, and air toxins. In the U.S. alone, the combined cost of coal-fire remediation projects that have been completed, budgeted, or projected by the U.S. Department of the Interior's Office of Surface Mining Remediation and Enforcement (OSM), exceeds $1 billion. It is estimated that these fires generate as much as 3% of the world's annual carbon dioxide emissions and consume as much as 5% of its minable coal. Considering the magnitude of environmental impact and economic loss caused by burning underground coal seams, we have developed a new, safe, reliable surface measurement of coal fire gases to assess the nature of underground coal fires. We use a drone mounted with gas sensors. Drone collected gas concentration data provides a safe alternative for evaluating the rank of a burning coal seam. In this study, a new method of determining coal rank by gas ratios is developed. Coal rank is valuable for defining parameters of a coal seam such as burn temperature, burn rate, and volume of burning seam. Copyright © 2017 Elsevier Ltd. All rights reserved.

Efficient power generation from large 7500C heat sources. Application to coal-fired and nuclear power station

International Nuclear Information System (INIS)

Tilliette, Z.P.; Pierre, B.

1980-03-01

Considering the future concern about a more efficient, rational use of heat sources, and also about a greater location flexibility of power plants owing to dry cooling possibility, closed gas cycles can offer new solutions for fossil or nuclear energy. An efficient heat conversion into power is obtained by the combination of a main non-intercooled helium cycle with a flexible, superheated, low pressure bottoming steam cycle. Emphasis is placed on the matching of the two cycle; for that, a recuperator by-pass arrangement is used. The operation of the main gas turbocompressor does not depend upon the operation of the small steam cycle. Results are given for a conservative turbine inlet temperature of 750 0 C. Applications are made to a coal-fired power plant and to a gas turbine, gas-cooled nuclear reactor. Overall net plant efficiencies of 39 per cent and 46 per cent respectively are reached. For a cycle top temperature equal to 850 0 C, corresponding net efficiencies would be 42 and 49 per cent

Potential health and environmental impacts attributable to the nuclear and coal fuel cycles: Final report

International Nuclear Information System (INIS)

Gotchy, R.L.

1987-06-01

Estimates of mortality and morbidity are presented based on present-day knowledge of health effects resulting from current component designs and operations of the nuclear and coal fuel cycles, and anticipated emission rates and occupational exposure for the various fuel cycle facilities expected to go into operation during the next decade. The author concluded that, although there are large uncertainties in the estimates of potential health effects, the coal fuel cycle alternative has a greater health impact on man than the uranium fuel fycle. However, the increased risk of health effects for either fuel cycle represents a very small incremental risk to the average individual in the public for the balance of this century. The potential for large impacts exists in both fuel cycles, but the potential impacts associated with a runaway Greenhouse Effect from combustion of fossil fuels, such as coal, cannot yet be reasonably quantified. Some of the potential environmental impacts of the coal fuel cycle cannot currently be realistically estimated, but those that can appear greater than those from the nuclear fuel cycle. 103 refs., 1 fig., 18 tabs

Integrated process for synthetic natural gas production from coal and coke-oven gas with high energy efficiency and low emission

International Nuclear Information System (INIS)

Man, Yi; Yang, Siyu; Qian, Yu

2016-01-01

Highlights: • A novel coal and coke-oven gas to SNG (CGtSNG) process is proposed. • Energy efficiency of CGtSNG increases 8% compared to coal-to-SNG process. • CGtSNG reduces 60% CO_2 emission and 72% effluent discharge. • CGtSNG proposes an idea of using redundant coke-oven gas for producing SNG production. - Abstract: There was a rapid development of coal to synthetic natural gas (SNG) projects in the last few years in China. The research from our previous work and some other researchers have found coal based SNG production process has the problems of environmental pollution and emission transfer, including CO_2 emission, effluent discharge, and high energy consumption. This paper proposes a novel co-feed process of coal and coke-oven gas to SNG process by using a dry methane reforming unit to reduce CO_2 emissions, more hydrogen elements are introduced to improve resource efficiency. It is shown that the energy efficiency of the co-feed process increases by 4%, CO_2 emission and effluent discharge is reduced by 60% and 72%, whereas the production cost decreases by 16.7%, in comparison to the conventional coal to SNG process. As coke-oven gas is a waste gas in most of the coking plant, this process also allows to optimize the allocation of resources.

Modular High Temperature Gas-Cooled Reactor heat source for coal conversion

International Nuclear Information System (INIS)

Schleicher, R.W. Jr.; Lewis, A.C.

1992-09-01

In the industrial nations, transportable fuels in the form of natural gas and petroleum derivatives constitute a primary energy source nearly equivalent to that consumed for generating electric power. Nations with large coal deposits have the option of coal conversion to meet their transportable fuel demands. But these processes themselves consume huge amounts of energy and produce undesirable combustion by-products. Therefore, this represents a major opportunity to apply nuclear energy for both the environmental and energy conservation reasons. Because the most desirable coal conversion processes take place at 800 degree C or higher, only the High Temperature Gas-Cooled Reactors (HTGRs) have the potential to be adapted to coal conversion processes. This report provides a discussion of this utilization of HTGR reactors

Evaporative gas turbine cycles. A thermodynamic evaluation of their potential

Energy Technology Data Exchange (ETDEWEB)

Rosen, P M

1993-03-01

The report presents a systematic method of thermodynamically evaluating different gas turbine cycles, treating the working fluids as ideal gases (c{sub p}=c{sub p}(T)). All models used to simulate different components in the cycles are presented in the report in detail and then connected in a computer program fully developed by the author. The report focuses on the theme of evaporative gas turbine cycles, in which low level heat is used to evaporate water into the compressed air stream between the compressor and recuperator. This leads to efficiency levels close to a comparable combined cycle but without the steam bottoming cycle. A parametric analysis has been conducted with the aim of deciding the best configuration of an evaporative cycle both for an uncooled expander and for a cooled expander. The model proposed to simulate the cooled expander is a combination between two existing models. (121 refs., 35 figs.,).

Forecast and Prevention of Coal and Gas Outbursts in the Case of Application of a New Mining Method - Drilling of a Coal Pillar

Directory of Open Access Journals (Sweden)

Vlastimil Hudeček

2010-10-01

Full Text Available Coal and gas outbursts are one of risk factors accompanying the mining of coal in low seams in the Ostrava-Karviná Coalfield.At the use of the method of longwall mining, all coal reserves have not been mined out owing to tectonic faults. For mining outthe residual reserves, the application of a new mining method - drilling of a coal pillar was proposed.The method of mining of a coal seam utilizing long large diameter boreholes is verified in the Paskov Mine (company OKD, JSC –Czech Republic under conditions of rock mass with hazard of rock and gas outbursts in localities of residual pillars left in seams afterfinishing the mining operations performed with using the classical method of longwall working along the strike. [5]Forecast and preventive measures applied to the verification of the new method were based on previous experience withthe mining of seams with hazard of coal and gas outbursts. They accepted fully valid legislation, i.e. Ordinance of Ostrava RegionalMining Authority No. 3895/2002 and supplementary materials (Instructions and Guidelines. The proposed measures respectedthe character of the method being verified. [4]For all areas being mined, projects containing also chapters specifying the problems of ensuring the safety of mining worksand operation under conditions of hazard of coal and gas outbursts were prepared.In the contributions, basic proposals for the principles of coal and gas outburst forecast and prevention when applying the newmining method – drilling of a coal pillar are presented

Assessment of the external costs of the coal fuel cycle and the wind energy cycle in Spain

International Nuclear Information System (INIS)

Linares, P.; Montes, J.; Saez, R.M.

1995-09-01

This study is part of the ExternE Project, a joint effort of the European Commission and the US Dept. of Energy to assess the externalities of different fuel cycles, and quantify them in monetary terms, as kWh price adders. For Spain, this assessment has been carried out for a coal plant hypothetically sited in Valdecaballeros, in Southwestern Spain, and for an existing farm in Cabo Villano, in the Northwestern corner. In this first stage, only environmental externalities have been assessed. The first section contains a description of the methodology used in the European project, based mostly on a damage function approach, and its adaptation to Spanish conditions. In the last section, this methodology has been applied to the fuel cycles mentioned. The impacts assessed have been, for the coal fuel cycle, health effects, agricultural and forest production losses, and global warming. For wind energy, the main impacts considered have been noise, loss of visual amenity, accidents and global warning. The results obtained can only be considered as underestimates, as there are still impacts that have not been assessed or quantified, specially for the coal fuel cycle. Thus, further research is needed for a complete assessment

GASCON and MHDGAS: FORTRAN IV computer codes for calculating gas and condensed-phase compositions in the coal-fired open-cycle MHD system

Energy Technology Data Exchange (ETDEWEB)

Blackburn, P E

1977-12-01

Fortran IV computer codes have been written to calculate the equilibrium partial pressures of the gaseous phase and the quantity and composition of the condensed phases in the open-cycle MHD system. The codes are based on temperature-dependent equilibrium constants, mass conservation, the mass action law, and assumed ideal solution of compounds in each of two condensed phases. It is assumed that the phases are an oxide-silicate phase and a sulfate-carbonate-hydroxide phase. Calculations are iterated for gas and condensate concentrations while increasing or decreasing the total moles of elements, but keeping mole ratios constant, to achieve the desired total pressure. During iteration the oxygen partial pressure is incrementally changed. The decision to increase or decrease the oxygen pressure in this process depends on comparison of the oxygen content calculated in the gas and condensate phases with the initial amount of oxygen in the ash, coal, seed, and air. This process, together with a normalization step, allows the elements to converge to their initial quantities. Two versions of the computer code have been written. GASCON calculates the equilibrium gas partial pressures and the quantity and composition of the condensed phases in steps of thirteen temperature and pressure combinations in which the condensate is removed after each step, simulating continuous slag removal from the MHD system. MHDGAS retains the condensate for each step, simulating flow of condensate (and gas) through the MHD system.

Coal fired flue gas mercury emission controls

CERN Document Server

Wu, Jiang; Pan, Weiguo; Pan, Weiping

2015-01-01

Mercury (Hg) is one of the most toxic heavy metals, harmful to both the environment and human health. Hg is released into the atmosphere from natural and anthropogenic sources and its emission control has caused much concern. This book introduces readers to Hg pollution from natural and anthropogenic sources and systematically describes coal-fired flue gas mercury emission control in industry, especially from coal-fired power stations. Mercury emission control theory and experimental research are demonstrated, including how elemental mercury is oxidized into oxidized mercury and the effect of

Near-Zero Emissions Oxy-Combustion Flue Gas Purification Task 2: SOx/Nox/Hg Removal for High Sulfur Coal

Energy Technology Data Exchange (ETDEWEB)

Nick Degenstein; Minish Shah; Doughlas Louie

2012-05-01

The goal of this project is to develop a near-zero emissions flue gas purification technology for existing PC (pulverized coal) power plants that are retrofitted with oxy-combustion technology. The objective of Task 2 of this project was to evaluate an alternative method of SOx, NOx and Hg removal from flue gas produced by burning high sulfur coal in oxy-combustion power plants. The goal of the program was not only to investigate a new method of flue gas purification but also to produce useful acid byproduct streams as an alternative to using a traditional FGD and SCR for flue gas processing. During the project two main constraints were identified that limit the ability of the process to achieve project goals. 1) Due to boiler island corrosion issues >60% of the sulfur must be removed in the boiler island with the use of an FGD. 2) A suitable method could not be found to remove NOx from the concentrated sulfuric acid product, which limits sale-ability of the acid, as well as the NOx removal efficiency of the process. Given the complexity and safety issues inherent in the cycle it is concluded that the acid product would not be directly saleable and, in this case, other flue gas purification schemes are better suited for SOx/NOx/Hg control when burning high sulfur coal, e.g. this project's Task 3 process or a traditional FGD and SCR.

Methanogenic pathways of coal-bed gas in the Powder River Basin, United States: The geologic factor

Energy Technology Data Exchange (ETDEWEB)

Flores, Romeo M.; Rice, Cynthia A.; Stricker, Gary D.; Warden, Augusta; Ellis, Margaret S. [U.S. Geological Survey, Box 25046, MS 939, Denver, Colorado 80225 (United States)

2008-10-02

Coal-bed gas of the Tertiary Fort Union and Wasatch Formations in the Powder River Basin in Wyoming and Montana, U.S. was interpreted as microbial in origin by previous studies based on limited data on the gas and water composition and isotopes associated with the coal beds. To fully evaluate the microbial origin of the gas and mechanisms of methane generation, additional data for 165 gas and water samples from 7 different coal-bed methane-bearing coal-bed reservoirs were collected basinwide and correlated to the coal geology and stratigraphy. The C{sub 1}/(C{sub 2} + C{sub 3}) ratio and vitrinite reflectance of coal and organic shale permitted differentiation between microbial gas and transitional thermogenic gas in the central part of the basin. Analyses of methane {delta}{sup 13}C and {delta}D, carbon dioxide {delta}{sup 13}C, and water {delta}D values indicate gas was generated primarily from microbial CO{sub 2} reduction, but with significant gas generated by microbial methyl-type fermentation (aceticlastic) in some areas of the basin. Microbial CO{sub 2} reduction occurs basinwide, but is generally dominant in Paleocene Fort Union Formation coals in the central part of the basin, whereas microbial methyl-type fermentation is common along the northwest and east margins. Isotopically light methane {delta}{sup 13}C is distributed along the basin margins where {delta}D is also depleted, indicating that both CO{sub 2}-reduction and methyl-type fermentation pathways played major roles in gas generation, but gas from the latter pathway overprinted gas from the former pathway. More specifically, along the northwest basin margin gas generation by methyl-type fermentation may have been stimulated by late-stage infiltration of groundwater recharge from clinker areas, which flowed through highly fractured and faulted coal aquifers. Also, groundwater recharge controlled a change in gas composition in the shallow Eocene Wasatch Formation with the increase of nitrogen and

Preliminary assessment of the environmental and health impacts of nuclear and coal fuel cycles

International Nuclear Information System (INIS)

Yang Yin; Chen Zhuzhou; Pan Ziqiang

1992-01-01

The paper reports on the environmental impacts and health effects of coal and nuclear fuel cycles in China. Data of interest for China are presented in a comparative manner; epidemiological investigations in Shanxi province indicate that the incidences of chronic pulmonary diseases and infant cogenital malformation were apparently increased over the fall-out areas of coal-fired power stations and coal mines. The authors outline the framework of a research project on environmental assessment of nuclear energy and other energy systems. The main features of the project are: environmental and health impacts of coal and nuclear fuel cycles, environmental impact assessment of coal transportation, cost accounting of nuclear and other energy sources, health risk assessment. (author). 24 refs, 4 tabs

The future of coal as an energy source

International Nuclear Information System (INIS)

Rose, Ian

1998-01-01

The position of coal as the preferred fossil fuel for power generation is being challenged by gas. The total cost of production in $/kW/annum of coal generation compared with combined cycle gas turbine plant is illustrated for a range of annual capacity factors and fuel costs in the Australian context. lt is shown that plant capacity factors over 80%are required for coal-fired plants to be price competitive with gas. Unlike other fossil fuel energy types, the high capital cost of coal-fired plant means that new coal-fired plant will generally need to be base-loaded throughout their operating life to be competitive. However, experience shows that having installed the plant, it will operate as base-loaded, intermediate or peaking duty depending on market circumstances. Existing plants In New South Wales, Victoria and Queensland are generally operating at annual capacity factors that are below optimum levels. It is concluded that the coal-fired energy industry can be strongly challenged for the foreseeable future

The evolution of gasification processes and reactors and the utilization of the coal gas. A proposition for the implementation of the gasification technology

International Nuclear Information System (INIS)

Pasculete, E.; Iorgulescu, S.

1996-01-01

Thermochemical treatment of coal by gasification, considered as a non-polluting technology to turn the coal highly-profitably is one of the alternative ways to produce gas with a high effective caloric capacity. Due to its advantages, the gasification has made through the last few decades significant advances from the point of view of the process efficiency (chemical, thermal), of motor outputs (in m 3 producer gas / m 2 reactor cross section x hour), of the solutions of supplying energy to support the endothermic reactions implied by the process, and especially of the reactors. Reactors have been developed from gas generators. Starting from gas generators various advanced reactors (of 1 st to 3 rd generation) have been developed to produce air gas, water gas or mixed gas. Applications of the producer gas were developed using it either as fuel or as synthesis gas in chemical industry or else as a substitute to the natural gas in combined cycle gas turbines where the gasification plant was integrated. In Romania there are projects in the field of coal gasification, namely at ICPET-RESEARCH, that can offer advanced technologies. One of these projects deals with the construction of the first demonstrative gasification plant based on a highly efficient process and equipped with a 10 G cal/h reactor. (author). 1 tab., 12 refs

Upper Paleozoic coal measures and unconventional natural gas systems of the Ordos Basin, China

Directory of Open Access Journals (Sweden)

Xuan Tang

2012-11-01

Full Text Available Upper Paleozoic coal measures in the Ordos Basin consist of dark mudstone and coal beds and are important source rocks for gas generation. Gas accumulations include coal-bed methane (CBM, tight gas and conventional gas in different structural areas. CBM accumulations are mainly distributed in the marginal area of the Ordos Basin, and are estimated at 3.5 × 1012 m3. Tight gas accumulations exist in the middle part of the Yishan Slope area, previously regarded as the basin-centered gas system and now considered as stratigraphic lithologic gas reservoirs. This paper reviews the characteristics of tight gas accumulations: poor physical properties (porosity < 8%, permeability < 0.85 × 10−3 μm2, abnormal pressure and the absence of well-defined gas water contacts. CBM is a self-generation and self-reservoir, while gas derived from coal measures migrates only for a short distance to accumulate in a tight reservoir and is termed near-generation and near-reservoir. Both CBM and tight gas systems require source rocks with a strong gas generation ability that extends together over wide area. However, the producing area of the two systems may be significantly different.

The impact of carbon sequestration on the production cost of electricity and hydrogen from coal and natural-gas technologies in Europe in the medium term

International Nuclear Information System (INIS)

Tzimas, Evangelos; Peteves, Stathis D.

2005-01-01

Carbon sequestration is a distinct technological option with a potential for controlling carbon emissions; it complements other measures, such as improvements in energy efficiency and utilization of renewable energy sources. The deployment of carbon sequestration technologies in electricity generation and hydrogen production will increase the production costs of these energy carriers. Our economic assessment has shown that the introduction of carbon sequestration technologies in Europe in 2020, will result in an increase in the production cost of electricity by coal and natural gas technologies of 30-55% depending on the electricity-generation technology used; gas turbines will remain the most competitive option for generating electricity; and integrated gasification combined cycle technology will become competitive. When carbon sequestration is coupled with natural-gas steam reforming or coal gasification for hydrogen production, the production cost of hydrogen will increase by 14-16%. Furthermore, natural-gas steam reforming with carbon sequestration is far more economically competitive than coal gasification

A sequential approach to control gas for the extraction of multi-gassy coal seams from traditional gas well drainage to mining-induced stress relief

International Nuclear Information System (INIS)

Kong, Shengli; Cheng, Yuanping; Ren, Ting; Liu, Hongyong

2014-01-01

Highlights: • The gas reservoirs characteristics are measured and analyzed. • A sequential approach to control gas of multi-gassy coal seams is proposed. • The design of gas drainage wells has been improved. • The utilization ways of different concentrations of gas production are shown. - Abstract: As coal resources become exhausted in shallow mines, mining operations will inevitably progress from shallow depth to deep and gassy seams due to increased demands for more coal products. However, during the extraction process of deeper and gassier coal seams, new challenges to current gas control methods have emerged, these include the conflict between the coal mine safety and the economic benefits, the difficulties in reservoirs improvement, as well as the imbalance between pre-gas drainage, roadway development and coal mining. To solve these problems, a sequential approach is introduced in this paper. Three fundamental principles are proposed: the mining-induced stress relief effect of the first-mined coalbed should be sufficient to improve the permeability of the others; the coal resource of the first-mined seams must be abundant to guarantee the economic benefits; the arrangement of the vertical wells must fit the underground mining panel. Tunlan coal mine is taken as a typical example to demonstrate the effectiveness of this approach. The approach of integrating surface coalbed methane (CBM) exploitation with underground gas control technologies brings three major benefits: the improvement of underground coal mining safety, the implementation of CBM extraction, and the reduction of greenhouse gas emissions. This practice could be used as a valuable example for other coal mines having similar geological conditions

Coal, energy of the future

International Nuclear Information System (INIS)

Lepetit, V.; Guezel, J.Ch.

2006-01-01

Coal is no longer considered as a 'has been' energy source. The production and demand of coal is growing up everywhere in the world because it has some strategic and technological advantages with respect to other energy sources: cheap, abundant, available everywhere over the world, in particular in countries with no geopolitical problems, and it is independent of supplying infrastructures (pipelines, terminals). Its main drawback is its polluting impact (dusts, nitrogen and sulfur oxides, mercury and CO 2 ). The challenge is to develop clean and high efficiency coal technologies like supercritical steam power plants or combined cycle coal gasification plants with a 50% efficiency, and CO 2 capture and sequestration techniques (post-combustion, oxy-combustion, chemical loop, integrated gasification gas combined cycle (pre-combustion)). Germany, who will abandon nuclear energy by 2021, is massively investing in the construction of high efficiency coal- and lignite-fired power plants with pollution control systems (denitrification and desulfurization processes, dust precipitators). (J.S.)

Secondary biogenic coal seam gas reservoirs in New Zealand: A preliminary assessment of gas contents

Energy Technology Data Exchange (ETDEWEB)

Butland, Carol I. [Department of Geological Sciences, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Moore, Tim A. [Department of Geological Sciences, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Solid Energy NZ Ltd., P.O. Box 1303, Christchurch (New Zealand)

2008-10-02

Four coal cores, one from the Huntly (Eocene), two from the Ohai (Cretaceous) and one from the Greymouth (Cretaceous) coalfields, were sampled and analysed in terms of gas content and coal properties. The coals vary in rank from subbituminous B-A (Huntly) to subbituminous C-A (Ohai), and high volatile A bituminous (Greymouth). Average gas contents were 1.60 m{sup 3}/t (s 0.2) in the Huntly core, 4.80 m{sup 3}/t (s = 0.8) in the Ohai cores, and 2.39 m{sup 3}/t (s = 0.8) in the Greymouth core. The Ohai core not only contained more gas but also had the highest saturation (75%) compared with the Huntly (33%) and Greymouth (45%) cores. Carbon isotopes indicate that the Ohai gas is more mature, containing higher {delta}{sup 13}C isotopes values than either the Huntly or Greymouth gas samples. This may indicate that the gas was derived from a mixed biogenic and thermogenic source. The Huntly and Greymouth gases appear to be derived solely from a secondary biogenic (by CO{sub 2} reduction) source. Although the data set is limited, preliminary analysis indicates that ash yield is the dominant control on gas volume in all samples where the ash yield was above 10%. Below 10%, the amount of gas variation is unrelated to ash yield. Although organic content has some influence on gas volume, associations are basin and/or rank dependent. In the Huntly core total gas content and structured vitrinite increase together. Although this relationship does not appear for the other core data for the Ohai SC3 core, lost gas and fusinite are associated whereas gelovitrinite (unstructured vitrinite) correlates positively with residual gas for the Greymouth data. (author)

Static and dynamic modelling of gas turbines in advanced cycles

Energy Technology Data Exchange (ETDEWEB)

Gustafsson, Jan-Olof

1998-12-01

Gas turbines have been in operation for at least 50 years. The engine is used for propulsion of aircraft and high speed ships. It is used for power production in remote locations and for peak load and emergency situations. Gas turbines have been used in combined cycles for 20 to 30 years. Highly efficient power plants based on gas turbines are a competitive option for the power industry today. The thermal efficiency of the simple cycle gas turbine has increased due to higher turbine inlet temperatures and improved compressor and expander designs. Equally important are the improved cycles in which the gas turbine operates. One example is the combined cycle that uses steam for turbine cooling. Steam is extracted from the bottoming cycle, then used as airfoil coolant in a closed loop and returned to the bottoming cycle. The Evaporative Gas Turbine (EvGT), also known as the Humid Air Turbine (HAT), is another advanced cycle. A mixture of air and water vapour is used as working media. Air from the compressor outlet is humidified and then preheated in a recuperator prior to combustion. The static and dynamic performance is changed when the gas turbine is introduced in an evaporative cycle. The cycle is gaining in popularity, but so far it has not been demonstrated. A Swedish joint program to develop the cycle has been in operation since 1993. As part of the program, a small pilot plant is being erected at the Lund Institute of Technology (LTH). The plant is based on a 600 kW gas turbine, and demonstration of the EvGT cycle started autumn 1998 and will continue, in the present phase, for one year. This thesis presents static and dynamic models for traditional gas turbine components, such as, the compressor, combustor, expander and recuperator. A static model for the humidifier is presented, based on common knowledge for atmospheric humidification. All models were developed for the pilot plant at LTH with the objective to support evaluation of the process and individual

An investigation on groundwater recovery rate within sub sea floor tunnels at closed coal mines

International Nuclear Information System (INIS)

Nakata, Eiji; Suenaga, Hiroshi; Oyama, Takahiro; Nomura, Tokisada; Ichihara, Yoshihisa

2008-01-01

The groundwater recovery rate investigated at the closed coal mines extended within sub sea floor tunnels. The Ikeshima and the Taiheiyo coal mine companies exploited the deep coal-bearing strata beneath the ocean. Ikeshima coal mine, excavated S.L. -650m to 6km offshore from Ikeshima island, was closed at November 2002, and Taiheiyo coal mine, excavated S.L. -720m to 9km offshore from Hokkaido, was stopped to excavate from the deep area at January 2003. After closing and stopping of development, we began the investigation of the groundwater recovery rate at both coal mines. The groundwater level of Ikeshima coal mine raised +405m per 1.8 years at the main shaft. The permeability coefficient estimated between 10 - 8 m /s and 10 -6 m/s to use the water recovery rate at the shaft. Otherwise, at Taiheiyo coal mine, we measured the air pressure in tubes used by 3.5km 2.5km, and 1.5km length 2mm diameters tubes to estimate the groundwater recovery level at the 3.2km offshore plug site. Groundwater didn't reach 4.7km (1.5+3.2km) area until November 2004. There were breakdown of shotcleate and rock mass from the roof of tunnel at 5.3km from offshore line. In this paper, we try to show the groundwater recovery rate of these sub sea floor collieries. (author)

Advanced design nuclear power plants: Competitive, economical electricity. An analysis of the cost of electricity from coal, gas and nuclear power plants

International Nuclear Information System (INIS)

1992-06-01

This report presents an updated analysis of the projected cost of electricity from new baseload power plants beginning operation around the year 2000. Included in the study are: (1) advanced-design, standardized nuclear power plants; (2) low emissions coal-fired power plants; (3) gasified coal-fired power plants; and (4) natural gas-fired power plants. This analysis shows that electricity from advanced-design, standardized nuclear power plants will be economically competitive with all other baseload electric generating system alternatives. This does not mean that any one source of electric power is always preferable to another. Rather, what this analysis indicates is that, as utilities and others begin planning for future baseload power plants, advanced-design nuclear plants should be considered an economically viable option to be included in their detailed studies of alternatives. Even with aggressive and successful conservation, efficiency and demand-side management programs, some new baseload electric supply will be needed during the 1990s and into the future. The baseload generating plants required in the 1990s are currently being designed and constructed. For those required shortly after 2000, the planning and alternatives assessment process must start now. It takes up to ten years to plan, design, license and construct a new coal-fired or nuclear fueled baseload electric generating plant and about six years for a natural gas-fired plant. This study indicates that for 600-megawatt blocks of capacity, advanced-design nuclear plants could supply electricity at an average of 4.5 cents per kilowatt-hour versus 4.8 cents per kilowatt-hour for an advanced pulverized-coal plant, 5.0 cents per kilowatt-hour for a gasified-coal combined cycle plant, and 4.3 cents per kilowatt-hour for a gas-fired combined cycle combustion turbine plant

Biogeochemical interactions between of coal mine water and gas well cement

Science.gov (United States)

Gulliver, D. M.; Gardiner, J. B.; Kutchko, B. G.; Hakala, A.; Spaulding, R.; Tkach, M. K.; Ross, D.

2017-12-01

Unconventional natural gas wells drilled in Northern Appalachia often pass through abandoned coal mines before reaching the Marcellus or Utica formations. Biogeochemical interactions between coal mine waters and gas well cements have the potential to alter the cement and compromise its sealing integrity. This study investigates the mineralogical, geochemical, and microbial changes of cement cores exposed to natural coal mine waters. Static reactors with Class H Portland cement cores and water samples from an abandoned bituminous Pittsburgh coal mine simulated the cement-fluid interactions at relevant temperature for time periods of 1, 2, 4, and 6 weeks. Fluids were analyzed for cation and anion concentrations and extracted DNA was analyzed by 16S rRNA gene sequencing and shotgun sequencing. Cement core material was evaluated via scanning electron microscope. Results suggest that the sampled coal mine water altered the permeability and matrix mineralogy of the cement cores. Scanning electron microscope images display an increase in mineral precipitates inside the cement matrix over the course of the experiment. Chemistry results from the reaction vessels' effluent waters display decreases in dissolved calcium, iron, silica, chloride, and sulfate. The microbial community decreased in diversity over the 6-week experiment, with Hydrogenophaga emerging as dominant. These results provide insight in the complex microbial-fluid-mineral interactions of these environments. This study begins to characterize the rarely documented biogeochemical impacts that coal waters may have on unconventional gas well integrity.

Cogeneration Technology Alternatives Study (CTAS). Volume 6: Computer data. Part 1: Coal-fired nocogeneration process boiler, section A

Science.gov (United States)

Knightly, W. F.

1980-01-01

Various advanced energy conversion systems (ECS) are compared with each other and with current technology systems for their savings in fuel energy, costs, and emissions in individual plants and on a national level. About fifty industrial processes from the largest energy consuming sectors were used as a basis for matching a similar number of energy conversion systems that are considered as candidates which can be made available by the 1985 to 2000 time period. The sectors considered included food, textiles, lumber, paper, chemicals, petroleum, glass, and primary metals. The energy conversion systems included steam and gas turbines, diesels, thermionics, stirling, closed cycle and steam injected gas turbines, and fuel cells. Fuels considered were coal, both coal and petroleum based residual and distillate liquid fuels, and low Btu gas obtained through the on-site gasification of coal. Computer generated reports of the fuel consumption and savings, capital costs, economics and emissions of the cogeneration energy conversion systems (ECS's) heat and power matched to the individual industrial processes are presented for coal fired process boilers. National fuel and emissions savings are also reported for each ECS assuming it alone is implemented.

Coal liquefaction and gas conversion: Proceedings. Volume 1

Energy Technology Data Exchange (ETDEWEB)

1993-12-31

Volume I contains papers presented at the following sessions: AR-Coal Liquefaction; Gas to Liquids; and Direct Liquefaction. Selected papers have been processed separately for inclusion in the Energy Science and Technology Database.

Technical project of complex fast cycle heat treatment of hydrogenous coal preparation

OpenAIRE

Moiseev, V. A.; Andrienko, V. G.; Pileckij, V. G.; Urvancev, A. I.; Gvozdyakov, Dmitry Vasilievich; Gubin, Vladimir Evgenievich; Matveev, Aleksandr Sergeevich; Savostiyanova, Ludmila Viktorovna

2015-01-01

Problems of heat-treated milled hydrogenous coal preparation site creation in leading fast cycle heat treatment complex were considered. Conditions for effective use of electrostatic methods of heat-treated milled hydrogenous coal preparation were set. Technical project of heat treatment of milled hydrogenous coal preparation site was developed including coupling of working equipment complex on fast heat treatment and experimental samples of equipment being designed for manufacturing. It was ...

Clean coal reference plants: Pulverized coal boiler with flue gas desulfurization. Topical report

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-09-01

The Clean Coal Technology Demonstration Program (CCT) is a government and industry cofunded technology development effort to demonstrate a new generation of innovative coal utilization processes in a series of full-scale facilities. The goal of the program is to provide the U.S. energy marketplace with a number of advanced, more efficient, and environmentally responsive coal-using technologies. To achieve this goal, a multiphased effort consisting of five separate solicitations has been completed. The Morgantown Energy Technology Center (METC) has the responsibility for monitoring the CCT Projects within certain technology categories, which, in general, correspond to the center`s areas of technology development. Primarily the categories of METC CCT projects are: atmospheric fluid bed combustion, pressurized fluidized bed combustion, integrated gasification combined cycle, mild gasification, and industrial applications.

Determination of coalbed methane potential and gas adsorption capacity in Western Kentucky coals

Science.gov (United States)

Mardon, S.M.; Takacs, K.G.; Hower, J.C.; Eble, C.F.; Mastalerz, Maria

2006-01-01

The Illinois Basin has not been developed for Coalbed Methane (CBM) production. It is imperative to determine both gas content and other parameters for the Kentucky portion of the Illinois Basin if exploration is to progress and production is to occur in this area. This research is part of a larger project being conducted by the Kentucky Geological Survey to evaluate the CBM production of Pennsylvanian-age western Kentucky coals in Ohio, Webster, and Union counties using methane adsorption isotherms, direct gas desorption measurements, and chemical analyses of coal and gas. This research will investigate relationships between CBM potential and petrographic, surface area, pore size, and gas adsorption isotherm analyses of the coals. Maceral and reflectance analyses are being conducted at the Center for Applied Energy Research. At the Indiana Geological Survey, the surface area and pore size of the coals will be analyzed using a Micrometrics ASAP 2020, and the CO2 isotherm analyses will be conducted using a volumetric adsorption apparatus in a water temperature bath. The aforementioned analyses will be used to determine site specific correlations for the Kentucky part of the Illinois Basin. The data collected will be compared with previous work in the Illinois Basin and will be correlated with data and structural features in the basin. Gas composition and carbon and hydrogen isotopic data suggest mostly thermogenic origin of coalbed gas in coals from Webster and Union Counties, Kentucky, in contrast to the dominantly biogenic character of coalbed gas in Ohio County, Kentucky.

Life Cycle Energy Consumption and Greenhouse Gas Emissions Analysis of Natural Gas-Based Distributed Generation Projects in China

Directory of Open Access Journals (Sweden)

Hansi Liu

2017-10-01

Full Text Available In this paper, we used the life-cycle analysis (LCA method to evaluate the energy consumption and greenhouse gas (GHG emissions of natural gas (NG distributed generation (DG projects in China. We took the China Resources Snow Breweries (CRSB NG DG project in Sichuan province of China as a base scenario and compared its life cycle energy consumption and GHG emissions performance against five further scenarios. We found the CRSB DG project (all energy input is NG can reduce GHG emissions by 22%, but increase energy consumption by 12% relative to the scenario, using coal combined with grid electricity as an energy input. The LCA also indicated that the CRSB project can save 24% of energy and reduce GHG emissions by 48% relative to the all-coal scenario. The studied NG-based DG project presents major GHG emissions reduction advantages over the traditional centralized energy system. Moreover, this reduction of energy consumption and GHG emissions can be expanded if the extra electricity from the DG project can be supplied to the public grid. The action of combining renewable energy into the NG DG system can also strengthen the dual merit of energy conservation and GHG emissions reduction. The marginal CO2 abatement cost of the studied project is about 51 USD/ton CO2 equivalent, which is relatively low. Policymakers are recommended to support NG DG technology development and application in China and globally to boost NG utilization and control GHG emissions.

Observer-based Coal Mill Control using Oxygen Measurements

DEFF Research Database (Denmark)

Andersen, Palle; Bendtsen, Jan Dimon; S., Tom

2006-01-01

This paper proposes a novel approach to coal flow estimation in pulverized coal mills, which utilizes measurements of oxygen content in the flue gas. Pulverized coal mills are typically not equipped with sensors that detect the amount of coal injected into the furnace. This makes control...... of the coal flow difficult, causing stability problems and limits the plant's load following capabilities. To alleviate this problem without having to rely on expensive flow measurement equipment, a novel observer-based approach is investigated. A Kalman filter based on measurements of combustion air flow led...... into the furnace and oxygen concentration in the flue gas is designed to estimate the actual coal flow injected into the furnace. With this estimate, it becomes possible to close an inner loop around the coal mill itself, thus giving a better disturbance rejection capability. The approach is validated against...

Report for fiscal 1993 by coal gasification committee; 1993 nendo sekitan gas ka iinkai hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1984-03-01

This report is a compilation mainly of distributed material. In the development of entrained bed coal gasification power generation, gasification is tested in a 2t/d-capable facility and gasification efficiency and operation characteristics are grasped, these constituting the studies of elements to assist pilot plant operation etc. The fluid temperature point of slag is found to decrease by 200 degrees C at the maximum upon addition of flux (CaO), and this improves on slag fluidity. For the development of a demonstration gas turbine, an experimentally built combustor is tested using a real gas. A combined cycle power system is studied by simulation. In the study of pilot plant operation, measures relative to slagging are implemented, inspection and maintenance are conducted for each facility, and the combustor for a demonstration plant is subjected to oil and coal combustion tests. In the study of a pilot plant for developing technologies for hydrogen production using coal, the plant stably runs more than 1,000 hours under 100% load at in a RUN-8-3 operation. Some deposit collects in the neighborhood of the contracted area of the blow nozzle and on some part in the slip stream, but it does not affect operation. No abnormalities are detected in the cyclone or heat recovery boiler. The pilot plant is let to continue its operation, and excellent results are achieved, which are beyond the targets of carbon conversion efficiency of 98% or higher and gas cooling efficiency of 78% or higher. (NEDO)

Environmental life cycle assessment of methanol and electricity co-production system based on coal gasification technology.

Science.gov (United States)

Śliwińska, Anna; Burchart-Korol, Dorota; Smoliński, Adam

2017-01-01

This paper presents a life cycle assessment (LCA) of greenhouse gas emissions generated through methanol and electricity co-production system based on coal gasification technology. The analysis focuses on polygeneration technologies from which two products are produced, and thus, issues related to an allocation procedure for LCA are addressed in this paper. In the LCA, two methods were used: a 'system expansion' method based on two approaches, the 'avoided burdens approach' and 'direct system enlargement' methods and an 'allocation' method involving proportional partitioning based on physical relationships in a technological process. Cause-effect relationships in the analysed production process were identified, allowing for the identification of allocation factors. The 'system expansion' method involved expanding the analysis to include five additional variants of electricity production technologies in Poland (alternative technologies). This method revealed environmental consequences of implementation for the analysed technologies. It was found that the LCA of polygeneration technologies based on the 'system expansion' method generated a more complete source of information on environmental consequences than the 'allocation' method. The analysis shows that alternative technologies chosen for generating LCA results are crucial. Life cycle assessment was performed for the analysed, reference and variant alternative technologies. Comparative analysis was performed between the analysed technologies of methanol and electricity co-production from coal gasification as well as a reference technology of methanol production from the natural gas reforming process. Copyright © 2016 Elsevier B.V. All rights reserved.

Dual Expander Cycle Rocket Engine with an Intermediate, Closed-cycle Heat Exchanger

Science.gov (United States)

Greene, William D. (Inventor)

2008-01-01

A dual expander cycle (DEC) rocket engine with an intermediate closed-cycle heat exchanger is provided. A conventional DEC rocket engine has a closed-cycle heat exchanger thermally coupled thereto. The heat exchanger utilizes heat extracted from the engine's fuel circuit to drive the engine's oxidizer turbomachinery.

Tunable Diode Laser Sensors to Monitor Temperature and Gas Composition in High-Temperature Coal Gasifiers

Energy Technology Data Exchange (ETDEWEB)

Hanson, Ronald [Stanford Univ., CA (United States); Whitty, Kevin [Univ. of Utah, Salt Lake City, UT (United States)

2014-12-01

The integrated gasification combined cycle (IGCC) when combined with carbon capture and storage can be one of the cleanest methods of extracting energy from coal. Control of coal and biomass gasification processes to accommodate the changing character of input-fuel streams is required for practical implementation of integrated gasification combined-cycle (IGCC) technologies. Therefore a fast time-response sensor is needed for real-time monitoring of the composition and ideally the heating value of the synthesis gas (here called syngas) as it exits the gasifier. The goal of this project was the design, construction, and demonstration an in situ laserabsorption sensor to monitor multiple species in the syngas output from practical-scale coal gasifiers. This project investigated the hypothesis of using laser absorption sensing in particulateladen syngas. Absorption transitions were selected with design rules to optimize signal strength while minimizing interference from other species. Successful in situ measurements in the dusty, high-pressure syngas flow were enabled by Stanford’s normalized and scanned wavelength modulation strategy. A prototype sensor for CO, CH4, CO2, and H2O was refined with experiments conducted in the laboratory at Stanford University, a pilot-scale at the University of Utah, and an engineering-scale gasifier at DoE’s National Center for Carbon Capture with the demonstration of a prototype sensor with technical readiness level 6 in the 2014 measurement campaign.

Exhaust circulation into dry gas desulfurization process to prevent carbon deposition in an Oxy-fuel IGCC power generation

International Nuclear Information System (INIS)

Kobayashi, Makoto; Nakao, Yoshinobu; Oki, Yuso

2014-01-01

Highlights: • Power plant with semi-closed gas turbine and O 2 –CO 2 coal gasifier was studied. • We adopt dry gas sulfur removal process to establish the system. • The exhaust gas circulation remarkably prevented carbon deposition. • Efficiency loss for exhaust gas circulation is quite small. • Appropriate operating condition of sulfur removal process is revealed. - Abstract: Semi-closed cycle operation of gas turbine fueled by oxygen–CO 2 blown coal gasification provides efficient power generation with CO 2 separation feature by excluding pre-combustion type CO 2 capture that usually brings large efficiency loss. The plant efficiency at transmission end is estimated as 44% at lower heating value (LHV) providing compressed CO 2 with concentration of 93 vol%. This power generation system will solve the contradiction between economical resource utilization and reduction of CO 2 emission from coal-fired power plant. The system requires appropriate sulfur reduction process to protect gas turbine from corrosion and environment from sulfur emission. We adopt dry gas sulfur removal process to establish the system where apprehension about the detrimental carbon deposition from coal gas. The effect of circulation of a portion of exhaust gas to the process on the retardation of carbon deposition was examined at various gas compositions. The circulation remarkably prevented carbon deposition in the sulfur removal sorbent. The impact of the circulation on the thermal efficiency is smaller than the other auxiliary power consumption. Thus, the circulation is appropriate operation for the power generation

Water Extraction from Coal-Fired Power Plant Flue Gas

Energy Technology Data Exchange (ETDEWEB)

Bruce C. Folkedahl; Greg F. Weber; Michael E. Collings

2006-06-30

The overall objective of this program was to develop a liquid disiccant-based flue gas dehydration process technology to reduce water consumption in coal-fired power plants. The specific objective of the program was to generate sufficient subscale test data and conceptual commercial power plant evaluations to assess process feasibility and merits for commercialization. Currently, coal-fired power plants require access to water sources outside the power plant for several aspects of their operation in addition to steam cycle condensation and process cooling needs. At the present time, there is no practiced method of extracting the usually abundant water found in the power plant stack gas. This project demonstrated the feasibility and merits of a liquid desiccant-based process that can efficiently and economically remove water vapor from the flue gas of fossil fuel-fired power plants to be recycled for in-plant use or exported for clean water conservation. After an extensive literature review, a survey of the available physical and chemical property information on desiccants in conjunction with a weighting scheme developed for this application, three desiccants were selected and tested in a bench-scale system at the Energy and Environmental Research Center (EERC). System performance at the bench scale aided in determining which desiccant was best suited for further evaluation. The results of the bench-scale tests along with further review of the available property data for each of the desiccants resulted in the selection of calcium chloride as the desiccant for testing at the pilot-scale level. Two weeks of testing utilizing natural gas in Test Series I and coal in Test Series II for production of flue gas was conducted with the liquid desiccant dehumidification system (LDDS) designed and built for this study. In general, it was found that the LDDS operated well and could be placed in an automode in which the process would operate with no operator intervention or

Production of activated char from Illinois coal for flue gas cleanup

Science.gov (United States)

Lizzio, A.A.; DeBarr, J.A.; Kruse, C.W.

1997-01-01

Activated chars were produced from Illinois coal and tested in several flue gas cleanup applications. High-activity chars that showed excellent potential for both SO2 and NOx removal were prepared from an Illinois No. 2 bituminous coal. The SO2 (120 ??C) and NOx (25 ??C) removal performance of one char compared favorably with that of a commercial activated carbon (Calgon Centaur). The NOx removal performance of the same char at 120 ??C exceeded that of the Centaur carbon by more than 1 order of magnitude. Novel char preparation methods were developed including oxidation/thermal desorption and hydrogen treatments, which increased and preserved, respectively, the active sites for SO2 and NOx adsorption. The results of combined SO2/NOx removal tests, however, suggest that SO2 and NOx compete for similar adsorption sites and SO2 seems to be more strongly adsorbed than NO. A low-activity, low-cost char was also developed for cleanup of incinerator flue gas. A three-step method involving coal preoxidation, pyrolysis, and CO2 activation was used to produce the char from Illinois coal. Five hundred pounds of the char was tested on a slipstream of flue gas from a commercial incinerator in Germany. The char was effective in removing >97% of the dioxins and furans present in the flue gas; mercury levels were below detectable limits.

Gas-Generator Augmented Expander Cycle Rocket Engine

Science.gov (United States)

Greene, William D. (Inventor)

2011-01-01

An augmented expander cycle rocket engine includes first and second turbopumps for respectively pumping fuel and oxidizer. A gas-generator receives a first portion of fuel output from the first turbopump and a first portion of oxidizer output from the second turbopump to ignite and discharge heated gas. A heat exchanger close-coupled to the gas-generator receives in a first conduit the discharged heated gas, and transfers heat to an adjacent second conduit carrying fuel exiting the cooling passages of a primary combustion chamber. Heat is transferred to the fuel passing through the cooling passages. The heated fuel enters the second conduit of the heat exchanger to absorb more heat from the first conduit, and then flows to drive a turbine of one or both of the turbopumps. The arrangement prevents the turbopumps exposure to combusted gas that could freeze in the turbomachinery and cause catastrophic failure upon attempted engine restart.

Development of standardized air-blown coal gasifier/gas turbine concepts for future electric power systems

Energy Technology Data Exchange (ETDEWEB)

Sadowski, R.S.; Brown, M.J.; Harriz, J.T.; Ostrowski, E.

1991-01-01

The cost estimate provided for the DOE sponsored study of Air Blown Coal Gasification was developed from vendor quotes obtained directly for the equipment needed in the 50 MW, 100 MW, and 200 MW sized plants and from quotes from other jobs that have been referenced to apply to the particular cycle. Quotes were generally obtained for the 100 MW cycle and a scale up/down factor was used to generate the cost estimates for the 200 MW and 50 MW cycles, respectively. Information from GTPro (property of Thermoflow, Inc.) was used to estimate the cost of the 200 MW and 50 MW gas turbine, HRSG, and steam turbines. To available the use of GTPro's estimated values for this equipment, a comparison was made between the quotes obtained for the 100 MW cycle (ABB GT 11N combustion turbine and a HSRG) against the estimated values by GTPro.

Next-generation coal utilization technology development study. Environmentally-friendly coal combustion technology; topping cycles; Sekitan riyo jisedai gijutsu kaihatsu chosa. Kankyo chowagata sekitan nensho gijutsu bun`ya (topping nensho gijutsu)

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-03-01

As a realistic measure to reduce environmental pollutants emitted from coal-fueled boilers, a developmental study was conducted of high-efficient combustion systems. In fiscal 1994, four types of topping cycles which are different in system structure and gasifier type were selected, and topping cycles assuming a 300MW-class power plant were trially designed. Further, an evaluation of adaptability of these systems was made, and an selection of the optimum system for the early development was made among the systems. As a result, the evaluation was obtained that `a system using air blown gasifier` is most suitable for conducting the next-stage research. In the element test on the topping combustion technology, collection was made of data of desulfurization activity, desulfurization oxidation mechanism and alkali metal behavior at the laboratory level, data of temperatures and gas concentration distribution in coal gasification, data of simulation of the gasifier reaction, and the other data. 262 figs., 66 tabs.

Closed-cycle 1-kHz-pulse-repetition-frequency HF(DF) laser

Science.gov (United States)

Harris, Michael R.; Morris, A. V.; Gorton, Eric K.

1998-05-01

We describe the design and performance of a closed cycle, high pulse repetition frequency HF(DF) laser. A short duration, glow discharge is formed in a 10 SF6:1 H2(D2) gas mixture at a total pressure of approximately 110 torr. A pair of profiled electrodes define a 15 X 0.5 X 0.5 cm3 discharge volume through which gas flow is forced in the direction transverse to the optical axis. A centrifugal fan provides adequate gas flow to enable operation up to 3 kHz repetition frequency. The fan also passes the gas through a scrubber cell in which ground state HF(DF) is eliminated from the gas stream. An automated gas make-up system replenishes the spent fuel gases removed by the scrubber. Total gas admission is regulated by monitoring the system pressure, whilst the correct fuel balance is maintained through measurement of the discharge voltage. The HF(DF) generation rate is determined to be close to 5 X 1019 molecules per second per watt of laser output. Typical mean laser output powers of up to 3 watts can be delivered for extended periods of time. The primary limitation to life is found to be the discharge pre- ionization system. A distributed resistance corona pre- ionizer is shown to be advantageous when compared with an alternative arc array scheme.

Hot coal gas desulfurization with manganese-based sorbents. Final report, September 1992--December 1994

Energy Technology Data Exchange (ETDEWEB)

Hepworth, M.T.; Slimane, R.B.

1994-11-01

The focus of much current work being performed by the Morgantown Energy Technology Center (METC) of the Department of Energy on hot coal-derived fuel gas desulfurization is in the use of zinc-based sorbents. METC has shown interest in formulating and testing manganese-based pellets as alternative effective sulfur sorbents in the 700 to 1200{degree}C temperature range. To substantiate the potential superiority of Mn-based pellets, a systematic approach toward the evaluation of the desulfurizing power of single-metal sorbents is developed based on thermodynamic considerations. This novel procedure considered several metal-based sorbents and singled out manganese oxide as a prime candidate sorbent capable of being utilized under a wide temperature range, irrespective of the reducing power (determined by CO{sub 2}/CO ratio) of the fuel gas. Then, the thermodynamic feasibility of using Mn-based pellets for the removal of H{sub 2}S from hot-coal derived fuel gases, and the subsequent oxidative regeneration of loaded (sulfided) pellets was established. It was concluded that MnO is the stable form of manganese for virtually all commercially available coal-derived fuel gases. In addition, the objective of reducing the H{sub 2}S concentration below 150 ppMv to satisfy the integrated gasification combined cycle system requirement was shown to be thermodynamically feasible. A novel process is developed for the manufacture of Mn-based spherical pellets which have the desired physical and chemical characteristics required.

Repowering with natural gas

International Nuclear Information System (INIS)

Wilkinson, P.L.

1992-01-01

This chapter examines the concept of combined-cycle repowering with natural gas as one possible solution to the impending dilemma facing electric utilities - tight capacity margins in the 1990s and the inordinate expense of traditional powerplants. Combined-cycle repowering refers to the production of electricity through the integration of new and used equipment at an existing site, with the final equipment configuration resembling a new gas-fired combined-cycle unit (i.e., gas turbine, waste heat recovery unit and steam turbine/generator). Through the utilization of improved waste heat recovery and gas-fired equipment, repowering provides both additional capacity and increased generating efficiency. Three modes of repowering are considered: (1) peak turbine repowering refers to the addition of a steam turbine and heat recovery unit to an existing gas turbine, with the efficiency improvement allowing the unit to convert from peaking to baseload operation; (2) heat recovery repowering is the replacement of an old coal boiler with a gas turbine and heat recovery unit, leaving the existing steam turbine in place; and (3) boiler repowering, in which the exhaust from a new gas turbine is fed into an existing coal boiler, replacing existing forced-draft fans and air heaters. These three options are compared with the option of adding new coal-fired boilers on the basis of economics, energy efficiency and environmental impacts

Portable rapid gas content measurement - an opportunity for a step change in the coal industry?

International Nuclear Information System (INIS)

Beamish, Basil; Kizil, Mehmet; Gu, Ming

2013-01-01

The last major advance in gas content measurement for coal seams was the introduction of the quick crush technique in the early 1990s. This is a laboratory test method that has proven very reliable over the years. Recent laboratory testing using a portable quick crushing device, known as the portable gas content analyser, has produced consistent gas content results for a set of core samples obtained from a single borehole that intersected four coal seams. The retained gas content values obtained for the seams show the same increasing gas content pattern and gas composition change with depth as the standard quick crush technique. Use of the portable gas content analyser provides the opportunity to produce rapid, reliable gas content measurement of coal that could be developed for assessing gas compliance cores and outburst-prone conditions at a mine site.

Integrated petrographic and geochemical study of coal and gas shales from the Sabinas and Chihuahua basins, North of Mexico: estimation of methane gas resources

International Nuclear Information System (INIS)

De La O Burrola, Francisco

2013-01-01

This comprehensive characterization study was performed using organic petrology and geochemistry conducted in the Sabinas basin and Chihuahua in northern Mexico. This information allowed a numerical modeling of gas formation, considering the thermal subsidence of coal and carbonaceous shales. The objectives of this thesis are: - Establish a characterization methodology for the studied rocks - Estimate potential gas generator and its regional distribution - Estimate the methane gas resources For the development of this project, we conducted an intensive campaign representative sampling of coal, carbonaceous shales and coal gas 'in situ'. For the Sabinas basin were studied 97 samples and 114 samples in the basin of Chihuahua. The analyses carried out that were used on the samples analyzed allowed to characterize the kerogen and gas. The methodology used to cross petrographic and geochemical information to analyze the petroleum system by numerical modeling. Analyses were: Petrographic, reflectance %Ro, elemental analysis and immediate, Rock Eval6 R (Bulk rock), isotopic analysis, δ 13 C, δD, (coal gas), scanning electron microscopy, image analysis and analysis of macerals fluid inclusions. The analyzes that were used on the samples allowed to characterize the sample, the kerogen and gas. The methodology used to cross petrographic and geochemical information for analyze the oil system by numerical modeling. Analyses were: Petrographic, reflectance %Ro, elemental analysis and immediate, Rock Eval6 R (Bulk rock), isotopic analysis, δ 13 C, δD, (coal gas), scanning electron microscopy, image analysis and analysis of macerals fluid inclusions A computer program was constructed to cross the information with the analysis of samples of artificial maturation experiments in the laboratory. This approach allowed estimation of methane gas resources generated by coal and carbonaceous shales. The main results obtained for Sabinas Basin were: - The kerogen of the

Thermochemical Equilibrium Model of Synthetic Natural Gas Production from Coal Gasification Using Aspen Plus

Directory of Open Access Journals (Sweden)

Rolando Barrera

2014-01-01

Full Text Available The production of synthetic or substitute natural gas (SNG from coal is a process of interest in Colombia where the reserves-to-production ratio (R/P for natural gas is expected to be between 7 and 10 years, while the R/P for coal is forecasted to be around 90 years. In this work, the process to produce SNG by means of coal-entrained flow gasifiers is modeled under thermochemical equilibrium with the Gibbs free energy approach. The model was developed using a complete and comprehensive Aspen Plus model. Two typical technologies used in entrained flow gasifiers such as coal dry and coal slurry are modeled and simulated. Emphasis is put on interactions between the fuel feeding technology and selected energy output parameters of coal-SNG process, that is, energy efficiencies, power, and SNG quality. It was found that coal rank does not significantly affect energy indicators such as cold gas, process, and global efficiencies. However, feeding technology clearly has an effect on the process due to the gasifying agent. Simulations results are compared against available technical data with good accuracy. Thus, the proposed model is considered as a versatile and useful computational tool to study and optimize the coal to SNG process.

Coupling Effect of Intruding Water and Inherent Gas on Coal Strength Based on the Improved (Mohr-Coulomb Failure Criterion

Directory of Open Access Journals (Sweden)

Yiyu Lu

2016-11-01

Full Text Available When employing hydraulic processes to increase gas drainage efficiency in underground coal mines, coal seams become a three-phase medium, containing water intruding into the coal pores with the inherent occurrence of gas. This can change the stress state of the coal and cause instability. This work studied the mechanical properties of coal containing water and gas and derived an appropriate failure criterion. Based on mixture theory of unsaturated porous media, the effective stress of coal, considering the interaction of water and gas, was analyzed, and the failure criterion established by combining this with the Mohr–Coulomb criterion. By introducing the stress factor of matrix suction and using fitted curves of experimentally determined matrix suction and moisture content, the relationships between coal strength, gas pressure, and moisture content were determined. To verify the established strength theory, a series of triaxial compression strength tests of coal containing water and gas were carried out on samples taken from the Songzao, Pingdingshan, and Tashan mines in China. The experimental results correlated well with the theoretical predictions. The results showed a linear decrease in the peak strength of coal with increasing gas pressure and an exponential reduction in peak strength with increasing moisture content. The strength theory of coal containing water and gas can become an important part of multiphase medium damage theory.

A new method for calculating gas content of coal reservoirs with consideration of a micro-pore overpressure environment

Directory of Open Access Journals (Sweden)

Jinxing Song

2017-05-01

Full Text Available When the gas content of a coal reservoir is calculated, the reservoir pressure measured by well logging and well testing is generally used for inversion calculation instead of gas pressure. However, the calculation result is not accurate because the reservoir pressure is not equal to the gas pressure in overpressure environments. In this paper, coal samples of different ranks in Shanxi and Henan are collected for testing the capillary pressure of coal pores. Based on the formation process of CBM reservoirs and the hydrocarbon generation and expulsion history of coal beds, the forming mechanisms of micro-pore overpressure environments in coal reservoirs were analyzed. Accordingly, a new method for calculating the gas content of coal reservoirs with consideration of a micro-pore overpressure environment was developed. And it was used to calculate the gas content of No. 1 coal bed of the 2nd member of Lower Permian Shanxi Fm in the Zhongmacun Coal Mine in Jiaozuo, Henan. It is indicated that during the formation and evolution of coals, some solid organic matters were converted into gas and water, and gas–water contact is surely formed in pores. In the end, capillary pressure is generated, so the gas pressure in micro-pores is much higher than the hydrostatic column pressure, which results in a micro-pore overpressure environment. Under such an environment, gas pressure is higher than reservoir pressure, so the gas content of coal reservoirs calculated previously based on the conventional reservoir pressure evaluation are usually underestimated. It is also found that the micro-pore overpressure environment exerts a dominating effect on the CBM content calculation of 3–100 nm pores, especially that of 3–10 nm pores, but a little effect on that of pores >100 nm. In conclusion, this new method clarifies the pressure environment of CBM gas reservoirs, thereby ensuring the calculation accuracy of gas content of coal reservoirs.

Dustfall design of open coal yard in the power plant-a case study on the closed reconstruction project of coal storage yard in shengli power plant

Science.gov (United States)

Wang, Kunpeng; Ji, Weidong; Zhang, Feifei; Yu, Wei; Zheng, Runqing

2018-02-01

This thesis, based on the closed reconstruction project of the coal storage yard of Shengli Power Plant which is affiliated to Sinopec Shengli Petroleum Administration, first makes an analysis on the significance of current dustfall reconstruction of open coal yard, then summarizes the methods widely adopted in the dustfall of large-scale open coal storage yard of current thermal power plant as well as their advantages and disadvantages, and finally focuses on this project, aiming at providing some reference and assistance to the future closed reconstruction project of open coal storage yard in thermal power plant.

Life-cycle analysis of shale gas and natural gas.

Energy Technology Data Exchange (ETDEWEB)

Clark, C.E.; Han, J.; Burnham, A.; Dunn, J.B.; Wang, M. (Energy Systems); ( EVS)

2012-01-27

The technologies and practices that have enabled the recent boom in shale gas production have also brought attention to the environmental impacts of its use. Using the current state of knowledge of the recovery, processing, and distribution of shale gas and conventional natural gas, we have estimated up-to-date, life-cycle greenhouse gas emissions. In addition, we have developed distribution functions for key parameters in each pathway to examine uncertainty and identify data gaps - such as methane emissions from shale gas well completions and conventional natural gas liquid unloadings - that need to be addressed further. Our base case results show that shale gas life-cycle emissions are 6% lower than those of conventional natural gas. However, the range in values for shale and conventional gas overlap, so there is a statistical uncertainty regarding whether shale gas emissions are indeed lower than conventional gas emissions. This life-cycle analysis provides insight into the critical stages in the natural gas industry where emissions occur and where opportunities exist to reduce the greenhouse gas footprint of natural gas.

Implications of the recent reductions in natural gas prices for emissions of CO2 from the US power sector.

Science.gov (United States)

Lu, Xi; Salovaara, Jackson; McElroy, Michael B

2012-03-06

CO(2) emissions from the US power sector decreased by 8.76% in 2009 relative to 2008 contributing to a decrease over this period of 6.59% in overall US emissions of greenhouse gases. An econometric model, tuned to data reported for regional generation of US electricity, is used to diagnose factors responsible for the 2009 decrease. More than half of the reduction is attributed to a shift from generation of power using coal to gas driven by a recent decrease in gas prices in response to the increase in production from shale. An important result of the model is that, when the cost differential for generation using gas rather than coal falls below 2-3 cents/kWh, less efficient coal fired plants are displaced by more efficient natural gas combined cycle (NGCC) generation alternatives. Costs for generation using NGCC decreased by close to 4 cents/kWh in 2009 relative to 2008 ensuring that generation of electricity using gas was competitive with coal in 2009 in contrast to the situation in 2008 when gas prices were much higher. A modest price on carbon could contribute to additional switching from coal to gas with further savings in CO(2) emissions.

Sustainable global energy development: The case of coal

International Nuclear Information System (INIS)

Brendow, Klaus

2004-01-01

Market-driven scenarios anticipate world coal demand to increase during the entire 21st century. The increase during 2000-2030 would range from 53 % to 100 %. Developing countries would take the lead in world coal demand growth. In western Europe, demand, and more so production, would decline, in central and eastern Europe increase. Carbon abatement policies would not impact on coal demand before 2020 - 2030. By 2050 however, under such constraints, coal demand would have declined by one third (only), - less in developing, more in developed countries. Under market conditions, the share of coal in world primary energy supplies, at 26 % in 2000, would decline to 24 % in 2020 and 22 % 2050. Carbon constraints would reduce the share of coal to 11 % in 2050, which (nevertheless) corresponds to 2.1 bill. tce (2000: 3.4 bill. tce). The major short-term competitor of coal would be gas, particularly under CO 2 emission constraints, although marginal gas is hardly better in terms of life cycle GHG emissions than marginal oil or coal. During 2001-2025, the increase of CO 2 emissions from coal (+1.1 bill. t of carbon) would be lower than for gas (+1.3 bill. t) and oil (+1.5 bill. t). In the longer term, new nuclear could emerge as a serious competitor. Electricity generators would remain the predominant customer for coal. By 2030, coal would cover 45 % of world electricity generation compared with 37 % in 2000. By 2020, coal-based methanol and hydrogen would cover 3 % of the world's transportation fuel demand (100 Mtoe), by 2050 14 % (660 Mtoe). Cumulative investments in coal mining, shipping and combustion during 2001-2030 would amount to USD 1900 billion, - 12 % of world investments in energy supply. International prices of coal relative to oil and gas would continue evolving in favour of coal enhancing its competitiveness. Almost nil in 2000, advanced coal combustion technologies would cover 33 % of world power generation in 2030, and 72 % of coal-based power generation

Measurements of Gasification Characteristics of Coal and Char in CO2-Rich Gas Flow by TG-DTA

Directory of Open Access Journals (Sweden)

Zhigang Li

2013-01-01

Full Text Available Pyrolysis, combustion, and gasification properties of pulverized coal and char in CO2-rich gas flow were investigated by using gravimetric-differential thermal analysis (TG-DTA with changing O2%, heating temperature gradient, and flow rate of CO2-rich gases provided. Together with TG-DTA, flue gas generated from the heated coal, such as CO, CO2, and hydrocarbons (HCs, was analyzed simultaneously on the heating process. The optimum O2% in CO2-rich gas for combustion and gasification of coal or char was discussed by analyzing flue gas with changing O2 from 0 to 5%. The experimental results indicate that O2% has an especially large effect on carbon oxidation at temperature less than 1100°C, and lower O2 concentration promotes gasification reaction by producing CO gas over 1100°C in temperature. The TG-DTA results with gas analyses have presented basic reference data that show the effects of O2 concentration and heating rate on coal physical and chemical behaviors for the expected technologies on coal gasification in CO2-rich gas and oxygen combustion and underground coal gasification.

Gas, electricity, coal: 1998 statistical data

International Nuclear Information System (INIS)

1999-01-01

This document brings together the main statistical data from the French direction of gas, electricity and coal and presents a selection of the most significant numbered data: origin of production, share of the consumption, price levels, resources-employment status. These data are presented in a synthetic and accessible way in order to make useful references for the actors of the energy sector. (J.S.)

Underground Coal Gasification: Rates of Post Processing Gas Transport

Czech Academy of Sciences Publication Activity Database

Soukup, Karel; Hejtmánek, Vladimír; Stanczyk, K.; Šolcová, Olga

2014-01-01

Roč. 68, č. 12 (2014), s. 1707-1715 ISSN 0366-6352 R&D Projects: GA MŠk 7C12017 Grant - others:RFCS(XE) RFCR-CT-2011-00002 Institutional support: RVO:67985858 Keywords : underground coal gas ification * gas transport * textural properties Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.468, year: 2014

Report on Seminar on Clean Coal Technology '93; Clean coal technology kokusai seminar hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-11-01

The program of the above clean coal technology (CCT) event is composed of 1) Coal energy be friendly toward the earth, 2) Research on CCT in America (study of coal structure under electron microscope), and 3) Research on CCT in Australia (high intensity combustion of ultrafine coal particles in a clean way). Remarks under item 1) are mentioned below. As for SO{sub 2} emissions base unit, Japan's is 1 at its coal-fired thermal power station while that of America is 7.8. As for the level of SO{sub 2}/NOx reduction attributable to coal utilization technologies, it rises in the order of flue gas desulfurizer-aided pulverized coal combustion, normal pressure fluidized bed combustion, pressurized fluidized bed combustion, integrated coal gasification combined cycle power generation, and integrated coal gasification combined cycle power generation/fuel cell. As for the level of CO2 reduction attributable to power generation efficiency improvement, provided that Japan's average power generation efficiency is 39% and if China's efficiency which is now 28% is improved to be similar to that of Japan, there will be a 40% reduction in CO2 emissions. Under item 2) which involves America's CCT program, reference is made to efforts at eliminating unnecessary part from the catalytic process and at reducing surplus air, to the export of CCT technology, and so forth. Under item 3), it is stated that coal cleaning may govern reaction efficiency in a process of burning coal particles for gasification. (NEDO)

Effect of replacing nitrogen with helium on a closed cycle diesel engine performance

Directory of Open Access Journals (Sweden)

Alaa M. Abo El Ela

2016-09-01

Full Text Available One of most important problems of closed cycle diesel engine is deterioration of cylinder pressure and consequently the engine power. Therefore this research aimed to establish a multi zone model using Computational Fluid Dynamic (CFD code; ANSYS Fluent 14.0 to enhance the closed cycle diesel engine performance. The present work investigates the effect of replacing nitrogen gas with helium gas in different concentration under different engine load and equivalence ratios. The numerical model results were validated with comparing them with those obtained from the previous experimental results. The engine which was used for the simulation analysis and the previous experimental work was a single cylinder with a displacement volume of 825 cm3, compression ratio of 17 and run at constant speed of 1500 RPM. The numerical results showed that replacing nitrogen with helium resulted in increasing the in-cylinder pressure. The results showed also that a percentage of 0.5–10% of helium on mass basis is sufficient in the recovery needed to overcome the drop in-cylinder pressure and hence power due to the existence of CO2 in the recycled gas up to 25%. When the CO2 % reaches 25%, it is required to use at least 10% of He as replacement gas to achieve the required recovery.

China's coal price disturbances: Observations, explanations, and implications for global energy economies

International Nuclear Information System (INIS)

Yang, Chi-Jen; Xuan, Xiaowei; Jackson, Robert B.

2012-01-01

Since China decontrolled coal prices, its coal price has risen steadily and been unusually volatile. In 2011 in particular, high coal prices and capped electricity prices in China discouraged coal-fired power generation, triggering widespread power shortages. We suggest that these coal-price disturbances could be symptomatic of a major change in pricing dynamics of global fossil-fuel markets, with increasing correspondence between coal and oil prices globally. Historically, global coal prices have been more stable and lower than oil and natural gas prices on a per-heat basis. In recent years, however, coal prices have been increasingly volatile worldwide and have tracked other fossil fuel prices more closely. Meanwhile, the recent development of unconventional gas has substantially decoupled US natural gas and oil prices. Technically, low US natural gas prices, with potential fuel switching, could drive US domestic coal prices lower. However, this effect is unlikely to counteract the overall trend in increasing coal consumption globally. China's market size and unique, partially-controlled energy system make its reform agenda a key force in the global economy. Policymakers in the US, E.U. and elsewhere should monitor China's economic reform agenda to anticipate and respond to changes accompanying China's increasing importance in the global energy economy. - Highlights: ► Since China decontrolled its coal prices, the price of coal has risen steadily in China, accompanied by unusual volatility. ► Relatively high and volatile coal prices have triggered widespread power shortages in China. ► Coal and oil prices have already become, and continue to become, more closely linked globally. ► China's demand will likely drive up global coal prices and make them as volatile as that of other fossil fuels. ► Policymakers should monitor China's economic reform agenda to anticipate and respond to changes in the global energy economy.

Comparative emissions from Pakistani coals and traditional coals

Energy Technology Data Exchange (ETDEWEB)

Du, Y X [Guangzhou Medical College (China). Dept. of Hygiene; Huang, L F [Guangzhou Health and Anti-epidemic Station (China)

1994-12-31

Briquette coal has been widely used for domestic cooking and heating in many Chinese cites over the last two decades. To determine whether burning briquette coal contributes significantly to indoor air pollution, a study was performed in cities-of Southern China in which the measured levels of SO{sub 2}, NO{sub x}, TSP, SD, B(a)P in the kitchens of coal burning families were compared with levels obtained in families using gas. Significantly higher contentions of these pollutants, whose peaks correlated with daily cooking episodes, were detected in coal burning families. The levels of TSP and B(a)P were further found to be dependent on cooking methods, with deep frying and stir-frying of meat generating the most indoor TSP and B(a)P. Briquette coal burning was found to be the source of B(a)P contamination in food. A higher incidence of chronic pharyngitis as well as a suppressed salivary bacteriolytic enzyme activity were found in children of coal burning families. Epidemiologic and laboratory studies also show a close association between coal burning and the incidence of lung cancer in females. (author)

Study on the propagation law of shock wave resulting from coal and gas outburst

Institute of Scientific and Technical Information of China (English)

WANG Kai; ZHOU Ai-tao; ZHANG Pin; LI Chuan; GUO Yan-wei

2011-01-01

According to the formation of shock wave resulting from coal and gas outburst, the gas flow of coal and gas outburst was transformed from an unsteady flow to a steady one based on selected appropriate reference coordinates, and the mathematical expressions were then established by applying mass conservation, momentum conservation equation, and energy conservation equation. On this basis, analyzed gas flow mitigation of variable cross-section area and the outburst intensity, and the relations between cross-section area, velocity, and density; the relations between overpressures and outburst intensity were deduced. Furthermore, shock waves resulting from coal and gas outburst and outburst intensity were measured by experimental setup, the overpressure and outburst intensity of different gas pressures were obtained, and the similar conditions of the experiment were numerically simulated. The averaged overpressure and gas flow velocity of variable cross-section under different gas pressures were numerically derived. The results show that the averaged overpressure and outburst intensity obtained from simulation are in good agreement with the experimental results. Moreover, the gas flow velocity of variable cross-sections approximates to the theoretical analysis.

The closed fuel cycle

International Nuclear Information System (INIS)

Froment, Antoine; Gillet, Philippe

2007-01-01

Available in abstract form only. Full text of publication follows: The fast growth of the world's economy coupled with the need for optimizing use of natural resources, for energy security and for climate change mitigation make energy supply one of the 21. century most daring challenges. The high reliability and efficiency of nuclear energy, its competitiveness in an energy market undergoing a new oil shock are as many factors in favor of the 'renaissance' of this greenhouse gas free energy. Over 160,000 tHM of LWR1 and AGR2 Used Nuclear Fuel (UNF) have already been unloaded from the reactor cores corresponding to 7,000 tons discharged per year worldwide. By 2030, this amount could exceed 400,000 tHM and annual unloading 14,000 tHM/year. AREVA believes that closing the nuclear fuel cycle through the treatment and recycling of Used Nuclear Fuel sustains the worldwide nuclear power expansion. It is an economically sound and environmentally responsible choice, based on the preservation of natural resources through the recycling of used fuel. It furthermore provides a safe and secure management of wastes while significantly minimizing the burden left to future generations. (authors)

The application of a coupled artificial neural network and fault tree analysis model to predict coal and gas outbursts

Energy Technology Data Exchange (ETDEWEB)

Ruilin, Zhang [School of Safety Science and Engineering, Henan Polytechnic University, Jiaozuo, Henan Province, 454003, PR (China); Lowndes, Ian S. [Process and Environmental Research Division, Faculty of Engineering, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom)

2010-11-01

This paper proposes the use of a coupled fault tree analysis (FTA) and artificial neural network (ANN) model to improve the prediction of the potential risk of coal and gas outburst events during the underground mining of thick and deep Chinese coal seams. The model developed has been used to investigate the gas emission characteristics and the geological conditions that exist within the Huaibei coal mining region, Anhui province, China. The coal seams in this region exhibit a high incidence of coal and gas outbursts. An analysis of the results obtained from an initial application of an FTA model, identified eight dominant model parameters related to the gas content or geological conditions of the coal seams, which characterize the potential risk of in situ coal and gas outbursts. The eight dominant model parameters identified by the FTA method were subsequently used as input variables to an ANN model. The results produced by the ANN model were used to develop a qualitative risk index to characterize the potential risk level of occurrence of coal and gas outburst events. Four different potential risk alarm levels were defined: SAFE, POTENTIAL, HIGH and STRONG. Solutions to the prediction model were obtained using a combination of quantitative and qualitative data including the gas content or gas pressure and the geological and geotechnical conditions of coal seams. The application of this combined solution method identified more explicit and accurate model relationships between the in situ geological conditions and the potential risk of coal and gas outbursts. An analysis of the model solutions concluded that the coupled FTA and ANN model may offer a reliable alternative method to forecast the potential risk of coal and gas outbursts. (author)

Wabash Valley Integrated Gasification Combined Cycle, Coal to Fischer Tropsch Jet Fuel Conversion Study

Energy Technology Data Exchange (ETDEWEB)

Shah, Jayesh [Lummus Technology Inc., Bloomfield, NJ (United States); Hess, Fernando [Lummus Technology Inc., Bloomfield, NJ (United States); Horzen, Wessel van [Lummus Technology Inc., Bloomfield, NJ (United States); Williams, Daniel [Lummus Technology Inc., Bloomfield, NJ (United States); Peevor, Andy [JM Davy, London (United Kingdom); Dyer, Andy [JM Davy, London (United Kingdom); Frankel, Louis [Canonsburgh, PA (United States)

2016-06-01

This reports examines the feasibility of converting the existing Wabash Integrated Gasification Combined Cycle (IGCC) plant into a liquid fuel facility, with the goal of maximizing jet fuel production. The fuels produced are required to be in compliance with Section 526 of the Energy Independence and Security Act of 2007 (EISA 2007 §526) lifecycle greenhouse gas (GHG) emissions requirements, so lifecycle GHG emissions from the fuel must be equal to or better than conventional fuels. Retrofitting an existing gasification facility reduces the technical risk and capital costs associated with a coal to liquids project, leading to a higher probability of implementation and more competitive liquid fuel prices. The existing combustion turbine will continue to operate on low cost natural gas and low carbon fuel gas from the gasification facility. The gasification technology utilized at Wabash is the E-Gas™ Technology and has been in commercial operation since 1995. In order to minimize capital costs, the study maximizes reuse of existing equipment with minimal modifications. Plant data and process models were used to develop process data for downstream units. Process modeling was utilized for the syngas conditioning, acid gas removal, CO₂ compression and utility units. Syngas conversion to Fischer Tropsch (FT) liquids and upgrading of the liquids was modeled and designed by Johnson Matthey Davy Technologies (JM Davy). In order to maintain the GHG emission profile below that of conventional fuels, the CO₂ from the process must be captured and exported for sequestration or enhanced oil recovery. In addition the power utilized for the plant’s auxiliary loads had to be supplied by a low carbon fuel source. Since the process produces a fuel gas with sufficient energy content to power the plant’s loads, this fuel gas was converted to hydrogen and exported to the existing gas turbine for low carbon power production. Utilizing low carbon fuel gas and

Conversion of Coal Mine Gas to LNG

Energy Technology Data Exchange (ETDEWEB)

None, None

2016-02-05

This project evolved from a 1995, DOE-NETL competitive solicitation for practical CMM capture and utilization concepts. Appalachian Pacific was one of three companies selected to proceed with the construction and operation of a cost-shared demonstration plant. In the course of trying to proceed with this demonstration plant, AP examined several liquefaction technologies, discussed obtaining rights to coal mine methane with a number of coal companies, explored marketing potential with a wide variety of customers in many sections of the United States, studied in great detail the impact of a carbon credit exchange, and developed a suite of analytical tools with which to evaluate possible project options. In the end, the newness of the product, reluctance on the part of the coal companies to venture away from time tested practices, difficulty with obtaining financing, the failure of a carbon credit market to develop and the emergence of shale derived gas production prevented a demonstration plant from being built.

PALLADIUM/COPPER ALLOY COMPOSITE MEMBRANES FOR HIGH TEMPERATURE HYDROGEN SEPARATION FROM COAL-DERIVED GAS STREAMS; F

International Nuclear Information System (INIS)

J. Douglas Way; Robert L. McCormick

2001-01-01

Recent advances have shown that Pd-Cu composite membranes are not susceptible to the mechanical, embrittlement, and poisoning problems that have prevented widespread industrial use of Pd for high temperature H(sub 2) separation. These membranes consist of a thin ((approx)10(micro)m) film of metal deposited on the inner surface of a porous metal or ceramic tube. Based on preliminary results, thin Pd(sub 60)Cu(sub 40) films are expected to exhibit hydrogen flux up to ten times larger than commercial polymer membranes for H(sub 2) separation, and resist poisoning by H(sub 2)S and other sulfur compounds typical of coal gas. Similar Pd-membranes have been operated at temperatures as high as 750 C. The overall objective of the proposed project is to demonstrate the feasibility of using sequential electroless plating to fabricate Pd(sub 60)Cu(sub 40) alloy membranes on porous supports for H(sub 2) separation. These following advantages of these membranes for processing of coal-derived gas will be demonstrated: High H(sub 2) flux; Sulfur tolerant, even at very high total sulfur levels (1000 ppm); Operation at temperatures well above 500 C; and Resistance to embrittlement and degradation by thermal cycling. The proposed research plan is designed to providing a fundamental understanding of: Factors important in membrane fabrication; Optimization of membrane structure and composition; Effect of temperature, pressure, and gas composition on H(sub 2) flux and membrane selectivity; and How this membrane technology can be integrated in coal gasification-fuel cell systems

Coal Mining and Coal Seam Gas on Gomeroi country: Sacred lands, economic futures and shifting alliances

International Nuclear Information System (INIS)

Norman, Heidi

2016-01-01

North western NSW has seen a host of interest groups working in alliance opposing coal and coal seam gas mining. These groups - farmers, residents and environmentalists share concerns about the impact on the unique black soil and aquifer, of fossil fuel more broadly. While these shared alliances across class, gender and generations are emergent, Aboriginal citizens are uniquely placed in this contest over land, environment and resources. This paper sets out to show the historical and contemporary significance of the place of Aboriginal people in the debate over land use, arguing that, for the first time in history, Aboriginal worlds are central to community futures. In this space, new relationships are being forged and new discourse is required to comprehend the complex position Aboriginal citizens have as custodians of place and at the same time, the responsibility to provide for families and communities, otherwise excluded from the prevailing modern economy. With reference to the history of both relationship to land and land usage over Gomeroi country, and drawing on ethnographic along with archival research, this article seeks to contribute to a critical understanding of Aboriginal people's dealings in relation to their land, their cultural and economic interests with in an emerging regional coal economy, and in turn how they are redefining the context for energy resource extraction, and energy policy. - Highlights: • Aboriginal worlds are central to community futures in Australia. • Prospecting for coal and coal seam gas is forcing Aboriginal land holders into new relationships. • The nexus between the coal economy & Aboriginal self-determination is deeply contested. • New discourses are emerging to comprehend the custodianship of place in the context of mining.

Water cycles in closed ecological systems: effects of atmospheric pressure.

Science.gov (United States)

Rygalov, Vadim Y; Fowler, Philip A; Metz, Joannah M; Wheeler, Raymond M; Bucklin, Ray A

2002-01-01

In bioregenerative life support systems that use plants to generate food and oxygen, the largest mass flux between the plants and their surrounding environment will be water. This water cycle is a consequence of the continuous change of state (evaporation-condensation) from liquid to gas through the process of transpiration and the need to transfer heat (cool) and dehumidify the plant growth chamber. Evapotranspiration rates for full plant canopies can range from ~1 to 10 L m-2 d-1 (~1 to 10 mm m-2 d-1), with the rates depending primarily on the vapor pressure deficit (VPD) between the leaves and the air inside the plant growth chamber. VPD in turn is dependent on the air temperature, leaf temperature, and current value of relative humidity (RH). Concepts for developing closed plant growth systems, such as greenhouses for Mars, have been discussed for many years and the feasibility of such systems will depend on the overall system costs and reliability. One approach for reducing system costs would be to reduce the operating pressure within the greenhouse to reduce structural mass and gas leakage. But managing plant growth environments at low pressures (e.g., controlling humidity and heat exchange) may be difficult, and the effects of low-pressure environments on plant growth and system water cycling need further study. We present experimental evidence to show that water saturation pressures in air under isothermal conditions are only slightly affected by total pressure, but the overall water flux from evaporating surfaces can increase as pressure decreases. Mathematical models describing these observations are presented, along with discussion of the importance for considering "water cycles" in closed bioregenerative life support systems.

Water cycles in closed ecological systems: effects of atmospheric pressure

Science.gov (United States)

Rygalov, Vadim Y.; Fowler, Philip A.; Metz, Joannah M.; Wheeler, Raymond M.; Bucklin, Ray A.; Sager, J. C. (Principal Investigator)

2002-01-01

In bioregenerative life support systems that use plants to generate food and oxygen, the largest mass flux between the plants and their surrounding environment will be water. This water cycle is a consequence of the continuous change of state (evaporation-condensation) from liquid to gas through the process of transpiration and the need to transfer heat (cool) and dehumidify the plant growth chamber. Evapotranspiration rates for full plant canopies can range from 1 to 10 L m-2 d-1 (1 to 10 mm m-2 d-1), with the rates depending primarily on the vapor pressure deficit (VPD) between the leaves and the air inside the plant growth chamber. VPD in turn is dependent on the air temperature, leaf temperature, and current value of relative humidity (RH). Concepts for developing closed plant growth systems, such as greenhouses for Mars, have been discussed for many years and the feasibility of such systems will depend on the overall system costs and reliability. One approach for reducing system costs would be to reduce the operating pressure within the greenhouse to reduce structural mass and gas leakage. But managing plant growth environments at low pressures (e.g., controlling humidity and heat exchange) may be difficult, and the effects of low-pressure environments on plant growth and system water cycling need further study. We present experimental evidence to show that water saturation pressures in air under isothermal conditions are only slightly affected by total pressure, but the overall water flux from evaporating surfaces can increase as pressure decreases. Mathematical models describing these observations are presented, along with discussion of the importance for considering "water cycles" in closed bioregenerative life support systems.

Community perspectives of natural resource extraction: coal-seam gas mining and social identity in Eastern Australia

Directory of Open Access Journals (Sweden)

David Lloyd

2013-01-01

Full Text Available Using a recent case study of community reaction to proposed coal-seam gas mining in eastern Australia, we illustrate the role of community views in issues of natural resource use. Drawing on interviews, observations and workshops, the paper explores the anti-coal-seam gas social movement from its stages of infancy through to being a national debate linking community groups across and beyond Australia. Primary community concerns of inadequate community consultation translate into fears regarding potential impacts on farmland and cumulative impacts on aquifers and future water supply, and questions regarding economic, social and environmental benefits. Many of the community activists had not previously been involved in such social action. A recurring message from affected communities is concern around perceived insufficient research and legislation for such rapid industrial expansion. A common citizen demand is the cessation of the industry until there is better understanding of underground water system interconnectivity and the methane extraction and processing life cycle. Improved scientific knowledge of the industry and its potential impacts will, in the popular view, enable better comparison of power generation efficiency with coal and renewable energy sources and better comprehension of the industry as a transition energy industry. It will also enable elected representatives and policy makers to make more informed decisions while developing appropriate legislation to ensure a sustainable future.

Lack of oil and gas resources leads to concentration on coal and nuclear energy

Energy Technology Data Exchange (ETDEWEB)

1989-10-20

The Bulgarian energy sector is characterised by a marked shortage of domestic resources. The country has no oil to speak of, no gas, relatively little hydro potential compared with its neighbours, and the one resource it does have in fair abundance - coal - is of the poorest quality. This poverty of resources has led to an extraordinary dependence on the Soviet Union for supplies of every resource and for technology to utilise them. Most oil, all gas, some electricity and even significant quantities of coal are all imported from the USSR. There is little Bulgaria can do about its oil needs for the transport sector, but otherwise current policy is to concentrate development in the nuclear and coal sectors. One of the main thrusts of the energy policy is to continue expansion of coal, largely opencast lignite deposits, in order to feed thermal power stations and, when clean coal technology is developed, to use coal in CHP plants. The country uses a small amount of natural gas but no development is foreseen; instead district heating is considered a more efficient use of resources. 5 figs., 1 tab.

Gas production strategy of underground coal gasification based on multiple gas sources.

Science.gov (United States)

Tianhong, Duan; Zuotang, Wang; Limin, Zhou; Dongdong, Li

2014-01-01

To lower stability requirement of gas production in UCG (underground coal gasification), create better space and opportunities of development for UCG, an emerging sunrise industry, in its initial stage, and reduce the emission of blast furnace gas, converter gas, and coke oven gas, this paper, for the first time, puts forward a new mode of utilization of multiple gas sources mainly including ground gasifier gas, UCG gas, blast furnace gas, converter gas, and coke oven gas and the new mode was demonstrated by field tests. According to the field tests, the existing power generation technology can fully adapt to situation of high hydrogen, low calorific value, and gas output fluctuation in the gas production in UCG in multiple-gas-sources power generation; there are large fluctuations and air can serve as a gasifying agent; the gas production of UCG in the mode of both power and methanol based on multiple gas sources has a strict requirement for stability. It was demonstrated by the field tests that the fluctuations in gas production in UCG can be well monitored through a quality control chart method.

Development of coal gas production technology acceptable for fuel cells; Nenryo denchiyo sekitan gas seizo gijutsu ni kansuru kenkyu

Energy Technology Data Exchange (ETDEWEB)

Watanabe, T [Center for Coal Utilization, Japan, Tokyo (Japan); Kimura, N; Omata, K [Electric Power Development Co. Ltd., Tokyo (Japan)

1996-09-01

In utilizing coal for high-efficiency direct power generation using fuel cells, it is necessary that coal be fed into the fuel cells after having been made into ash-free gaseous fuel. Research and development works are being carried out with an objective to develop a coal gasification furnace most suitable for fuel cells and establish a system to refine coal up to the one that can be fed into fuel cells. Fiscal 1995 has conducted investigations on coal gasification technologies, air separation technologies, and gas refining technologies as the important element technologies, and a trial design on integrated coal gasification fuel cell (IGFC) systems. This paper reports from among the above items the result of the trial design on an IGFC system using molten carbonate fuel cells. The paper describes system comparison on paths of produced gases and anode waste gas, comparison on refining processes using a wet system and a dry system, and parameter studies on oxygen concentration in gasifying agents. It was made clear that the suitable furnace is an oxygen blown coal gasification furnace, and the power generation efficiency at the system terminal can be higher than 53%. 11 figs., 6 tabs.

Hydrogen sulfide removal from hot coal gas by various mesoporous silica supported Mn2O3 sorbents

International Nuclear Information System (INIS)

Zhang, Z.F.; Liu, B.S.; Wang, F.; Wang, W.S.; Xia, C.; Zheng, S.; Amin, R.

2014-01-01

Graphical abstract: - Highlights: • Mn 2 O 3 /KIT-1 presented the best desulfurization performance at 600–850 °C. • High sulfur capacity of Mn 2 O 3 /KIT-1 correlated closely with 3-D channel of KIT-1. • Desulfurization character depended strongly on framework structure of sorbents. • High steam content suppressed greatly the occurrence of sulfidation reaction. - Abstract: A series of 50 wt% Mn 2 O 3 sorbents was prepared using various mesoporous silica, MCM-41, HMS, and KIT-1 as support. The influence of textural parameters of mesoporous silica, especially type of channel on the desulfurization performance of Mn 2 O 3 sorbents was investigated at 600–850 °C using hot coal gas containing 0.33 vol.% H 2 S. The fresh and used sorbents were characterized by means of N 2 -adsorption, x-ray diffraction (XRD), high resolution transmission microscopy (HRTEM) and H 2 temperature- programmed reduction (H 2 -TPR) techniques. The results confirmed that the manganese oxide was dispersed highly in regular pore channel of the mesoporous supports due to high surface area. Compared with the Mn 2 O 3 /diatomite, all mesoporous silica supported Mn 2 O 3 sorbents exhibited high breakthrough sulfur capacity and a sharp deactivation rate after the breakthrough point. Compared to Mn 2 O 3 /MCM-41 and Mn 2 O 3 /HMS sorbent, the Mn 2 O 3 /KIT-1 showed better desulfurization performance because of the 3D wormhole-like channel. The high sulfur capacity of the Mn 2 O 3 /KIT-1 sorbent was maintained during the eight consecutive desulfurization-regeneration cycles. The Mn 2 O 3 /KIT-1 still presented high desulfurization activity when hot coal gas contained low steam (<5%)

Health effects attributable to coal and nuclear fuel cycle alternatives

International Nuclear Information System (INIS)

Gotchy, R.L.

1977-09-01

Estimates of mortality and morbidity are presented based on present-day knowledge of health effects resulting from current component designs and operations of the fuel cycles, and anticipated emission rates and occupational exposure for the various fuel cycle facilities expected to go into operation in approximately the 1975-1985 period. It was concluded that, although there are large uncertainties in the estimates of potential health effects, the coal fuel cycle alternative has a greater health impact on man than the uranium fuel cycle. However, the increased risk of health effects for either fuel cycle represents a very small incremental risk to the average individual in the public

Evaluating the gas content of coals and isolated maceral concentrates from the Paleocene Guasare Coalfield, Venezuela

International Nuclear Information System (INIS)

Berbesi, L.A.; Marquez, G.; Martinez, M.; Requena, A.

2009-01-01

This work presents the results from evaluating the gases sorbed by coal samples extracted from the Paleocene Guasare Coalfield (Marcelina Formation, northwestern Venezuela), as well as by their distinct maceral concentrates. The aim of this work has been to obtain an initial experimental main value of the gas content per unit weight of high volatile bituminous A coal samples from the open-pit Paso Diablo mine. An additional goal was to study differences in the CH 4 storage ability of the distinct maceral groups forming part of the coal matrix. Both the coal samples and the maceral concentrates were studied by thermogravimetric analysis (TGA) in order to determine the temperature to be used in subsequent experiments. On-line analyses of hydrocarbons (C 1 , C 2 , C 3 ) and CO 2 yielded gas concentrations, plus δ 13 C values. Thermogenic gas is prevalent in the Guasare coals with vitrinite reflectance (%R o ) values from 0.65% to 0.88%. The amount of gas retained in the coals and maceral concentrates was measured with a special device that allows determination of the volume of gas sorbed by a solid sample subjected to controlled thermal treatment. The average coalbed gas concentration obtained was 0.51 cm 3 /g. The following list of maceral concentrates shows the relative capacity for the volume of sorbed gas per unit weight: inertinite > low-density vitrinite > liptinite ∼ high-density vitrinite. It is concluded that the gas volumes retained in the distinct maceral concentrates are not controlled by porosity but rather by their microscopic morphology.

Development of closed cycle infrastructure at VNIPIET

International Nuclear Information System (INIS)

Onufrienko, S.V.; Kuzin, A.S.; Shafrova, N.P.; Zavadskij, M.I.

2012-01-01

Background to the creation of a closed nuclear fuel cycle is described. Achievements and future development projects of the Leading Institute VNIPIET are listed. The diagram of the closed nuclear fuel cycle in Russia with separate uranium and plutonium recycling is given. The major milestones of the VNIPIET history are reported [ru

Coal gasification and the power production market

International Nuclear Information System (INIS)

Howington, K.; Flandermeyer, G.

1995-01-01

The US electric power production market is experiencing significant changes sparking interest in the current and future alternatives for power production. Coal gasification technology is being marketed to satisfy the needs of the volatile power production industry. Coal gasification is a promising power production process in which solid coal is burned to produce a synthesis gas (syn gas). The syn gas may be used to fuel combustion integrated into a facility producing electric power. Advantages of this technology include efficient power production, low flue gas emissions, flexible fuel utilization, broad capability for facility integration, useful process byproducts, and decreased waste disposal. The primary disadvantages are relatively high capital costs and lack of proven long-term operating experience. Developers of coal gasification intend to improve on these disadvantages and lop a strong position in the power generation market. This paper is a marketing analysis of the partial oxidation coal gasification processes emerging in the US in response to the market factors of the power production industry. A brief history of these processes is presented, including the results of recent projects exploring the feasibility of integrated gasification combined cycle (IGCC) as a power production alternative. The current power generation market factors are discussed, and the status of current projects is presented including projected performance

Numerical simulation of coupled binary gas-solid interaction during carbon dioxide sequestration in a coal bed

International Nuclear Information System (INIS)

Feng Qiyan; Zhou Lai; Chen Zhongwei; Liu Jishan

2008-01-01

Complicated coupled binary gas-solid interaction arises during carbon dioxide sequestration in a coal seam, which combines effects of CO 2 -CH 4 counter adsorption, CO 2 -CH 4 counter diffusion, binary gas flow and coal bed deformation. Through solving a set of coupled field governing equations, a novel full coupled Finite Element (FE) model was established by COMSOL Multiphysics. The new FE model was applied to the quantification of coal porous pressure, coal permeability, gas composition fraction and coal displacement when CO 2 was injected in a CH 4 saturated coal bed. Numerical results demonstrate that CH 4 is swept by the injected CO 2 accompanied by coal volumetric deformation. Compared to the single CH 4 in situ, CH 4 -CO 2 counter-diffusion induced coal swelling can make more compensation for coal shrinkage due to effective stress. Competing influences between the effective stress and the CH 4 -CO 2 counter-diffusion induced volume change governs the evolution of porous pressure and permeability, which is controlled by the porous pressure correspondingly. This achievement extends our ability to understand the coupled multi-physics of the CO 2 geological sequestration and CO 2 enhanced coal bed methane recovery under field conditions. (authors)

Slag processing system for direct coal-fired gas turbines

Science.gov (United States)

Pillsbury, Paul W.

1990-01-01

Direct coal-fired gas turbine systems and methods for their operation are provided by this invention. The gas turbine system includes a primary zone for burning coal in the presence of compressed air to produce hot combustion gases and debris, such as molten slag. The turbine system further includes a secondary combustion zone for the lean combustion of the hot combustion gases. The operation of the system is improved by the addition of a cyclone separator for removing debris from the hot combustion gases. The cyclone separator is disposed between the primary and secondary combustion zones and is in pressurized communication with these zones. In a novel aspect of the invention, the cyclone separator includes an integrally disposed impact separator for at least separating a portion of the molten slag from the hot combustion gases.

Coal geopolitics

International Nuclear Information System (INIS)

Giraud, P.N.; Suissa, A.; Coiffard, J.; Cretin, D.

1991-01-01

This book divided into seven chapters, describes coal economic cycle. Chapter one: coals definition; the principle characteristics and properties (origin, calorific power, international classification...) Chapter two: the international coal cycle: coal mining, exploration, coal reserves estimation, coal handling coal industry and environmental impacts. Chapter three: the world coal reserves. Chapter four: the consumptions, productions and trade. Chapter five: the international coal market (exporting mining companies; importing companies; distributors and spot market operators) chapter six: the international coal trade chapter seven: the coal price formation. 234 refs.; 94 figs. and tabs [fr

Modeling and simulation of syngas purification and power generation in integrated gasification combined cycle (IGCS)

Energy Technology Data Exchange (ETDEWEB)

Mehmood, N; Zaman, Z U; Mehran, M T [National Development, Islamabad (Pakistan)

2011-07-01

Integrated Gasification Combined Cycle (IGCC) is one of the most promising technologies for power generation; The environmental benefits and the higher energy conversion efficiency distinguish it from traditional coal generation technologies. This work presents a structured and validated conceptual model of purification of coal gas produced during the Underground Coal Gasification (UCG) of coal containing high sulfur contents. Gas cleaning operations for CO/sub 2/, H/sub 2/S and moisture removal have been modeled in steady and dynamic state. The power generation from combined cycle is also modeled. The model has been developed using Aspen HYSYS and Aspen Plus simulation software. Predicted results of clean gas composition and generated power present a good agreement with industrial data and efficiency parameters. This study is aimed at obtaining optimal assessment of an integrated gasification combined cycle (IGCC) power plant configurations. (author)

Modeling and simulation of syngas purification and power generation in integrated gasification combined cycle (IGCS)

International Nuclear Information System (INIS)

Mehmood, N.; Zaman, Z.U.; Mehran, M.T.

2011-01-01

Integrated Gasification Combined Cycle (IGCC) is one of the most promising technologies for power generation; The environmental benefits and the higher energy conversion efficiency distinguish it from traditional coal generation technologies. This work presents a structured and validated conceptual model of purification of coal gas produced during the Underground Coal Gasification (UCG) of coal containing high sulfur contents. Gas cleaning operations for CO/sub 2/, H/sub 2/S and moisture removal have been modeled in steady and dynamic state. The power generation from combined cycle is also modeled. The model has been developed using Aspen HYSYS and Aspen Plus simulation software. Predicted results of clean gas composition and generated power present a good agreement with industrial data and efficiency parameters. This study is aimed at obtaining optimal assessment of an integrated gasification combined cycle (IGCC) power plant configurations. (author)

Experience with unconventional gas turbine fuels

Energy Technology Data Exchange (ETDEWEB)

Mukherjee, D K [ABB Power Generation Ltd., Baden (Switzerland)

1997-12-31

Low grade fuels such as Blast Furnace Gas, biomass, residual oil, coke, and coal - if used in conjunction with appropriate combustion, gasification, and clean-up processes and in combination with a gas turbine combined cycle -offer attractive and environmentally sound power generation. Recently, the Bao Shan Iron and Steel Company in Shanghai placed an order with Kawasaki Heavy Industries, Japan, to supply a combined-cycle power plant. The plant is to employ ABB`s GT 11N2 with a combustor modified to burn blast furnace gas. Recent tests in Shanghai and at Kawasaki Steel, Japan, have confirmed the burner design. The same basic combustor concept can also be used for the low BTU gas derived from airblown gasification processes. ABB is also participating in the API project: A refinery-residual gasification combined-cycle plant in Italy. The GT 13E2 gas turbine employees MBTU EV burners that have been successfully tested under full operating conditions. These burners can also handle the MBTU gas produced in oxygenblown coal gasification processes. ABB`s vast experience in burning blast furnace gas (21 plants built during the 1950s and 1960s), residuals, crude, and coal in various gas turbine applications is an important asset for building such power plants. This presentation discusses some of the experience gained in such plants. (orig.) 6 refs.

Experience with unconventional gas turbine fuels

Energy Technology Data Exchange (ETDEWEB)

Mukherjee, D.K. [ABB Power Generation Ltd., Baden (Switzerland)

1996-12-31

Low grade fuels such as Blast Furnace Gas, biomass, residual oil, coke, and coal - if used in conjunction with appropriate combustion, gasification, and clean-up processes and in combination with a gas turbine combined cycle -offer attractive and environmentally sound power generation. Recently, the Bao Shan Iron and Steel Company in Shanghai placed an order with Kawasaki Heavy Industries, Japan, to supply a combined-cycle power plant. The plant is to employ ABB`s GT 11N2 with a combustor modified to burn blast furnace gas. Recent tests in Shanghai and at Kawasaki Steel, Japan, have confirmed the burner design. The same basic combustor concept can also be used for the low BTU gas derived from airblown gasification processes. ABB is also participating in the API project: A refinery-residual gasification combined-cycle plant in Italy. The GT 13E2 gas turbine employees MBTU EV burners that have been successfully tested under full operating conditions. These burners can also handle the MBTU gas produced in oxygenblown coal gasification processes. ABB`s vast experience in burning blast furnace gas (21 plants built during the 1950s and 1960s), residuals, crude, and coal in various gas turbine applications is an important asset for building such power plants. This presentation discusses some of the experience gained in such plants. (orig.) 6 refs.

Enabling Technology for Monitoring & Predicting Gas Turbine Health & Performance in COAL IGCC Powerplants

Energy Technology Data Exchange (ETDEWEB)

Kenneth A. Yackly

2004-09-30

The ''Enabling & Information Technology To Increase RAM for Advanced Powerplants'' program, by DOE request, has been re-directed, de-scoped to two tasks, shortened to a 2-year period of performance, and refocused to develop, validate and accelerate the commercial use of enabling materials technologies and sensors for Coal IGCC powerplants. The new program has been re-titled as ''Enabling Technology for Monitoring & Predicting Gas Turbine Health & Performance in IGCC Powerplants'' to better match the new scope. This technical progress report summarizes the work accomplished in the reporting period April 1, 2004 to August 31, 2004 on the revised Re-Directed and De-Scoped program activity. The program Tasks are: Task 1--IGCC Environmental Impact on high Temperature Materials: This first materials task has been refocused to address Coal IGCC environmental impacts on high temperature materials use in gas turbines and remains in the program. This task will screen material performance and quantify the effects of high temperature erosion and corrosion of hot gas path materials in Coal IGCC applications. The materials of interest will include those in current service as well as advanced, high-performance alloys and coatings. Task 2--Material In-Service Health Monitoring: This second task develops and demonstrates new sensor technologies to determine the in-service health of advanced technology Coal IGCC powerplants, and remains in the program with a reduced scope. Its focus is now on only two critical sensor need areas for advanced Coal IGCC gas turbines: (1) Fuel Quality Sensor for detection of fuel impurities that could lead to rapid component degradation, and a Fuel Heating Value Sensor to rapidly determine the fuel heating value for more precise control of the gas turbine, and (2) Infra-Red Pyrometer to continuously measure the temperature of gas turbine buckets, nozzles, and combustor hardware.

Proceedings of the advanced coal-fired power systems `95 review meeting, Volume I

Energy Technology Data Exchange (ETDEWEB)

McDaniel, H.M.; Mollot, D.J.; Venkataraman, V.K.

1995-06-01

This document contains papers presented at The advanced Coal-Fired Power Systems 1995 Review Meeting. Research was described in the areas of: integrated gasification combined cycle technology; pressurized fluidized-bed combustion; externally fired combined cycles; a summary stauts of clean coal technologies; advanced turbine systems and hot gas cleanup. Individual projects were processed separately for the United States Department of Energy databases.

Production of gasoline from coal or natural gas by the methanol-to-gasoline process

Energy Technology Data Exchange (ETDEWEB)

Heinritz-Adrian, M.; Brandl, A.; Zhoa, Xinjin; Tabak, S. [Uhde GmbH, Dortmund (Germany)

2007-07-01

After discussing the basis of the methanol-to-gas (MTG) process, the fixed bed and fluid bed versions are described. The Motunui and MTG complex near Montunui, New Zealand that methanol uses natural gas is briefly described. Shanxi Jincheng, Anthracite Coal Mining Co. is currently building its first coal-based MTG plant. 7 refs., 2 tabs.

Wettability determination by contact angle measurements: hvbB coal-water system with injection of synthetic flue gas and CO2.

Science.gov (United States)

Shojai Kaveh, Narjes; Rudolph, E Susanne J; Wolf, Karl-Heinz A A; Ashrafizadeh, Seyed Nezameddin

2011-12-01

Geological sequestration of pure carbon dioxide (CO(2)) in coal is one of the methods to sequester CO(2). In addition, injection of CO(2) or flue gas into coal enhances coal bed methane production (ECBM). The success of this combined process depends strongly on the wetting behavior of the coal, which is function of coal rank, ash content, heterogeneity of the coal surface, pressure, temperature and composition of the gas. The wetting behavior can be evaluated from the contact angle of a gas bubble, CO(2) or flue gas, on a coal surface. In this study, contact angles of a synthetic flue gas, i.e. a 80/20 (mol%) N(2)/CO(2) mixture, and pure CO(2) on a Warndt Luisenthal (WL) coal have been determined using a modified pendant drop cell in a pressure range from atmospheric to 16 MPa and a constant temperature of 318 K. It was found that the contact angles of flue gas on WL coal were generally smaller than those of CO(2). The contact angle of CO(2) changes from water-wet to gas-wet by increasing pressure above 8.5 MPa while the one for the flue gas changes from water-wet to intermediate-wet by increasing pressure above 10 MPa. Copyright © 2011 Elsevier Inc. All rights reserved.

Closed-Cycle, Frequency-Stable CO2 Laser Technology

Science.gov (United States)

Batten, Carmen E. (Editor); Miller, Irvin M. (Editor); Wood, George M., Jr. (Editor); Willetts, David V. (Editor)

1987-01-01

These proceedings contain a collection of papers and comments presented at a workshop on technology associated with long-duration closed-cycle operation of frequency-stable, pulsed carbon dioxide lasers. This workshop was held at the NASA Langley Research Center June 10 to 12, 1986. The workshop, jointly sponsored by the National Aeronautics and Space Administration (NASA) and the Royal Signals and Radar Establishment (RSRE), was attended by 63 engineers and scientists from the United States and the United Kingdom. During the 2 1/2 days of the workshop, a number of issues relating to obtaining frequency-stable operation and to the catalytic control of laser gas chemistry were discussed, and specific recommendations concerning future activities were drafted.

Size Effect on Acoustic Emission Characteristics of Coal-Rock Damage Evolution

OpenAIRE

Wen, Zhijie; Wang, Xiao; Chen, Lianjun; Lin, Guan; Zhang, Hualei

2017-01-01

Coal-gas outburst, rock burst, and other mine dynamic disasters are closely related to the instability and failure of coal-rock. Coal-rock is the assemblies of mineral particles of varying sizes and shapes bonded together by cementing materials. The damage and rupture process of coal-rock is accompanied by acoustic emission (AE), which can be used as an effective means to monitor and predict the instability of coal-rock body. In this manuscript, considering the size effect of coal-rock, the i...

Prediction and control of rock burst of coal seam contacting gas in deep mining

Energy Technology Data Exchange (ETDEWEB)

En-yuan Wang; Xiao-fei Liu; En-lai Zhao; Zhen-tang Liu [China University of Mining and Technology, Xuzhou (China). School of Safety Engineering

2009-06-15

By analyzing the characteristics and the production mechanism of rock burst that goes with abnormal gas emission in deep coal seams, the essential method of eliminating abnormal gas emission by eliminating the occurrence of rock burst or depressing the magnitude of rock burst was considered. The No.237 working face in Nanshan coal mine was selected as the typical working face contacting gas in deep mining; aimed at this working face, a system of rock burst prediction and control for coal seam contacting gas in deep mining was established using the three-dimensional distinct element code software 3DEC. This system includes three parts: (1) regional prediction of rock burst hazard before mining; (2) local prediction of rock burst hazard during mining; and (3) rock burts control by an electromagnetic radiation method and specific drilling method. 8 refs., 4 figs., 1 tab.

Coal fired steam generation for heavy oil recovery

International Nuclear Information System (INIS)

Firmin, K.

1992-01-01

In Alberta, some 21,000 m 3 /d of heavy oil and bitumen are produced by in-situ recovery methods involving steam injection. The steam generation requirement is met by standardized natural-gas-fired steam generators. While gas is in plentiful supply in Alberta and therefore competitively priced, significant gas price increases could occur in the future. A 1985 study investigating the alternatives to natural gas as a fuel for steam generation concluded that coal was the most economic alternative, as reserves of subbituminous coal are not only abundant in Alberta but also located relatively close to heavy oil and bitumen production areas. The environmental performance of coal is critical to its acceptance as an alternate fuel to natural gas, and proposed steam generator designs which could burn Alberta coal and control emissions satisfactorily are assessed. Considerations for ash removal, sulfur dioxide sorption, nitrogen oxides control, and particulate emission capture are also presented. A multi-stage slagging type of coal-fired combustor has been developed which is suitable for application with oilfield steam generators and is being commissioned for a demonstration project at the Cold Lake deposit. An economic study showed that the use of coal for steam generation in heavy oil in-situ projects in the Peace River and Cold Lake areas would be economic, compared to natural gas, at fuel price projections and design/cost premises for a project timing in the mid-1990s. 7 figs., 3 tabs

Fiscal 1999 report on basic research for promotion of joint implementation programs. Research on collection and utilization of coal mine methane gas in Russia (Kuznetsk coal field); Russia (Kuznetsk tanden) ni okeru tanko methane gas kaishu riyo chosa hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

The above-mentioned effort is to comply with the COP3 (Third Session of the Conference of the Parties to the United Nations Framework Convention on Climate Change) joint implementation clause. At this coal field, mining facilities are growing superannuated and obsolescent in the prolonged business depression, causing frequent occurrence of disasters such as gas explosions. The coal mine gas collection rate at the Kuznetsk coal field is as low as 17%, with concern for safety discouraging sufficient collection. Even the small amount of the collected gas is, in the absence of gas utilizing facilities, totally discharged into the air. For the mitigation of global warming, for mining safety, and for the establishment of a foundation for business, it is desired that coal mine methane gas collection/utilization facilities and related technologies be introduced into the coal field. Gas purging from the pits is incomplete, which is attributed to the lack of equipment capable of excavating proper-diameter bores longer than 100m for longwall mining. Ventilation also needs improvement. The research is under way on the premise that highly reliable intermediate range (300m) boring equipment and gas management technologies will be available. Collection of gas of a 30-35% concentration level at a collection rate of 40% is the target. (NEDO)

The challenge for gas: get price-competitive with coal-fired electricity

International Nuclear Information System (INIS)

Gill, Len

1999-01-01

The challenge for the gas industry is to become price competitive with coal-fired electricity if it wants a larger share of the energy market. Returning to the issue of greater use of gas for electricity generation, the author points out that although electricity prices were rising they were still below the point where gas-fired electricity generation was viable. Copyright (1999) The Australian Gas Journal

Gas Production Strategy of Underground Coal Gasification Based on Multiple Gas Sources

Directory of Open Access Journals (Sweden)

Duan Tianhong

2014-01-01

Full Text Available To lower stability requirement of gas production in UCG (underground coal gasification, create better space and opportunities of development for UCG, an emerging sunrise industry, in its initial stage, and reduce the emission of blast furnace gas, converter gas, and coke oven gas, this paper, for the first time, puts forward a new mode of utilization of multiple gas sources mainly including ground gasifier gas, UCG gas, blast furnace gas, converter gas, and coke oven gas and the new mode was demonstrated by field tests. According to the field tests, the existing power generation technology can fully adapt to situation of high hydrogen, low calorific value, and gas output fluctuation in the gas production in UCG in multiple-gas-sources power generation; there are large fluctuations and air can serve as a gasifying agent; the gas production of UCG in the mode of both power and methanol based on multiple gas sources has a strict requirement for stability. It was demonstrated by the field tests that the fluctuations in gas production in UCG can be well monitored through a quality control chart method.

Development of the first coal seam gas exploration program in Indonesia: Reservoir properties of the Muaraenim Formation, south Sumatra

Energy Technology Data Exchange (ETDEWEB)

Sosrowidjojo, I.B. [R and D Centre for Oil and Gas Technology, LEMIGAS, Jakarta (Indonesia); Saghafi, A. [CSIRO Energy Technology, P O Box 330, Newcastle, NSW, 2300 (Australia)

2009-09-01

The Late Miocene Muaraenim Formation in southern Sumatra contains thick coal sequences, mostly of low rank ranging from lignite to sub-bituminous, and it is believed that these thick low rank coals are the most prospective for the production of coal seam gas (CSG), otherwise known as coalbed methane (CBM), in Indonesia. As part of a major CSG exploration project, gas exploration drilling operations are being undertaken in Rambutan Gasfields in the Muaraenim Formation to characterize the CSG potential of the coals. The first stage of the project, which is described here, was designed to examine the gas reservoir properties with a focus on coal gas storage capacity and compositional properties. Some five CSG exploration boreholes were drilled in the Rambutan Gasfield, south of Palembang. The exploration boreholes were drilled to depths of {proportional_to} 1000 m into the Muaraenim Formation. Five major coal seams were intersected by these holes between the depths of 450 and 1000 m. The petrography of coal samples collected from these seams showed that they are vitrinite rich, with vitrinite contents of more than 75% (on a mineral and moisture free basis). Gas contents of up to 5.8 m{sup 3}/t were measured for the coal samples. The gas desorbed from coal samples contain mainly methane (CH{sub 4}) ranging from 80 to 93% and carbon dioxide (CO{sub 2}) ranging from 6 to 19%. The composition of the gas released into the production borehole/well is, however, much richer in CH{sub 4} with about 94 to 98% CH{sub 4} and less than 5% CO{sub 2}. The initial results of drilling and reservoir characterization studies indicate suitable gas recovery parameters for three of the five coal seams with a total thickness of more than 30 m. (author)

Closed-cycle gas turbine power generating system

International Nuclear Information System (INIS)

Jubb, A.; Ward, R.G.; Hurst, J.N.; Holliday, J.B.; Ashley, J.W.

1975-01-01

The invention deals with a gas-cooled reactor with at least one condenser, one turbin and one off-gas heat exchanger for preheating the coolant arranged in the pressure vessel inside a common supporting structure in the from of a pipe cylinder. This supporting structure can be removed from the pressure vessel independently of the core. The pipe cylinder is connected with the core feeding and recirculation lines. It has axial coolant channels in the cylindrical wall. The heat exchanger consists of a large number of coolant channels in axial direction. The feeding line is surrounded by several interpenetrating elastic ring elements. (HP) [de

Closed cycle device

International Nuclear Information System (INIS)

Ruby, L.E.; Witt, D.L.; Staley, C.F.

1975-01-01

A gas dynamic laser wherein the lasing fluid is recirculated in a closed loop is described. The flow can be assumed to start with the lasing gas passing through a cascade of supersonic nozzles. This low pressure, high velocity gas is then passed through a lasing cavity where the lasing action takes place. The energy of the high velocity gas stream is converted back to static pressure in a supersonic diffuser. The diffuser is constructed with (1) variable geometry, and (2) provisions for bleeding off the boundary layer for improved efficiency. Downstream of the supersonic diffuser there is a heat exchanger which partially cools the gas in the loop. This partially cooled gas is then supplied to a compressor where the pressure and temperature are raised back to the level at the start of the flow. The lasing gas is directed from the exit of the compressor to a manifold upstream of the cascade of supersonic nozzles. The compressor only supplies a pressure rise equal to the pressure loss by inefficiencies in the nozzle, the supersonic diffuser and the pressure drop in the heatexchanger and plumbing. To provide for cooling of the compressor, the gas bled from the diffuser is cooled by a second heat exchanger and pumped back to compressor inlet pressure and introduced into the compressor for cooling. In steady state operation, both heat exchangers referred to above, are designed to regulatethe nozzle inlet gas temperature by removing the amount of heat energy added by compressing minus the amount of energy extracted in the lasing beam and energy lost to the environment. The compressor and pumping means for cooling the compressor can be driven by any means desired. (U.S.)

Highly stable and regenerable Mn-based/SBA-15 sorbents for desulfurization of hot coal gas

International Nuclear Information System (INIS)

Zhang, F.M.; Liu, B.S.; Zhang, Y.; Guo, Y.H.; Wan, Z.Y.; Subhan, Fazle

2012-01-01

Highlights: ► A series of mesoporous Cu x Mn y O z /SBA-15 sorbents were fabricated for hot coal gas desulfurization. ► 1Cu9Mn/SBA-15 sorbent with high breakthrough sulfur capacity is high stable and regenerable. ► Utilization of SBA-15 constrained the sintering and pulverization of sorbents. - Abstract: A series of mesoporous xCuyMn/SBA-15 sorbents with different Cu/Mn atomic ratios were prepared by wet impregnation method and their desulfurization performance in hot coal gas was investigated in a fixed-bed quartz reactor in the range of 700–850 °C. The successive nine desulfurization–regeneration cycles at 800 °C revealed that 1Cu9Mn/SBA-15 presented high performance with durable regeneration ability due to the high dispersion of Mn 2 O 3 particles incorporated with a certain amount of copper oxides. The breakthrough sulfur capacity of 1Cu9Mn/SBA-15 observed 800 °C is 13.8 g S/100 g sorbents, which is remarkably higher than these of 40 wt%LaFeO 3 /SBA-15 (4.8 g S/100 g sorbents) and 50 wt%LaFe 2 O x /MCM-41 (5.58 g S/100 g sorbents) used only at 500–550 °C. This suggested that the loading of Mn 2 O 3 active species with high thermal stability to SBA-15 support significantly increased sulfur capacity at relatively higher sulfidation temperature. The fresh and used xCuyMn/SBA-15 sorbents were characterized by means of BET, XRD, XPS, XAES, TG/DSC and HRTEM techniques, confirmed that the structure of the sorbents remained intact before and after hot coal gas desulfurization.

Radiation heat transfer within an open-cycle MHD generator channel

Science.gov (United States)

Delil, A. A. M.

1983-05-01

Radiation heat transfer in an MHD generator was modeled using the Sparrow and Cess model for radiation in an emitting, absorbing and scattering medium. The resulting general equations can be considerably reduced by introducing simplifying approximations for the channel and MHD gas properties. The simplifications lead to an engineering model, which is very useful for one-dimensional channel flow approximation. The model can estimate thermo-optical MHD gas properties, which can be substituted in the energy equation. The model considers the contribution of solid particles in the MHD gas to radiation heat transfer, considerable in coal-fired closed cycle MHD generators. The modeling is applicable also for other types of flow at elevated temperatures, where radiation heat transfer is an important quantity.

Effects of coal storage in air on physical and chemical properties of coal and on gas adsorption

Science.gov (United States)

Mastalerz, Maria; Solano-Acosta, W.; Schimmelmann, A.; Drobniak, A.

2009-01-01

This paper investigates changes in the high-volatile bituminous Lower Block Coal Member from Indiana owing to moisture availability and oxidation in air at ambient pressure and temperature over storage time. Specifically, it investigates changes in chemistry, in surface area, and pore structure, as well as changes in methane and carbon dioxide adsorption capacities. Our results document that the methane adsorption capacity increased by 40%, whereas CO2 adsorption capacity increased by 18% during a 13-month time period. These changes in adsorption are accompanied by changes in chemistry and surface area of the coal. The observed changes in adsorption capacity indicate that special care must be taken when collecting samples and preserving coals until adsorption characteristics are measured in the laboratory. High-pressure isotherms from partially dried coal samples would likely cause overestimation of gas adsorption capacities, lead to a miscalculation of coal-bed methane prospects, and provide deceptively optimistic prognoses for recovery of coal-bed methane or capture of anthropogenic CO2. ?? 2009 Elsevier B.V. All rights reserved.

Method for increasing the calorific value of gas produced by the in situ combustion of coal

Science.gov (United States)

Shuck, Lowell Z.

1978-01-01

The present invention relates to the production of relatively high Btu gas by the in situ combustion of subterranean coal. The coal bed is penetrated with a horizontally-extending borehole and combustion is initiated in the coal bed contiguous to the borehole. The absolute pressure within the resulting combustion zone is then regulated at a desired value near the pore pressure within the coal bed so that selected quantities of water naturally present in the coal will flow into the combustion zone to effect a hydrogen and carbon monoxide-producing steam-carbon reaction with the hot carbon in the combustion zone for increasing the calorific value of the product gas.

Life-Cycle Analysis of Greenhouse Gas Emissions and Water Consumption – Effects of Coal and Biomass Conversion to Liquid Fuels as Analyzed with the GREET Model

Energy Technology Data Exchange (ETDEWEB)

Li, Qianfeng [Argonne National Lab. (ANL), Argonne, IL (United States); Cai, Hao [Argonne National Lab. (ANL), Argonne, IL (United States); Han, Jeongwoo [Argonne National Lab. (ANL), Argonne, IL (United States)

2017-06-01

The vast reserves of coal in the U.S. provide a significant incentive for the development of processes for coal conversion to liquid fuels (CTL). Also, CTL using domestic coal can help move the U.S. toward greater energy independence and security. However, current conversion technologies are less economically competitive and generate greater greenhouse gas (GHG) emissions than production of petroleum fuels. Altex Technologies Corporation (Altex, hereinafter) and Pennsylvania State University have developed a hybrid technology to produce jet fuel from a feedstock blend of coal and biomass. Collaborating with Altex, Argonne National Laboratory has expanded and used the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET®) model to assess the life-cycle GHG emissions and water consumption of this hybrid technology. Biomass feedstocks include corn stover, switchgrass, and wheat straw. The option of biomass densification (bales to pellets) is also evaluated in this study. The results show that the densification process generates additional GHG emissions as a result of additional biomass process energy demand. This process coproduces a large amount of char, and this study investigates two scenarios to treat char: landfill disposal (Char-LF) and combustion for combined heat and power (CHP). Since the CHP scenarios export excess heat and electricity as coproducts, two coproduct handling methods are used for well-to-wake (WTWa) analysis: displacement (Char-CHP-Disp) and energy allocation (Char-CHP-EnAllo). When the feedstock contains 15 wt% densified wheat straw and 85 wt% lignite coal, WTWa GHG emissions of the coal-and-biomass-to-liquid pathways are 116, 97, and 137 gCO2e per megajoule (MJ) under the Char-LF, Char-CHP-Disp, and Char-CHP-EnAllo scenarios, respectively, as compared to conventional jet fuel production at 84 gCO2e/MJ. WTWa water consumption values are 0.072, -0.046, and 0.044 gal/MJ for Char-LF, Char-CHP-Disp, and Char

Evaluation of dense-phase ultrafine coal (DUC) as a fuel alternative for oil- and gas-designed boilers and heaters. Final report

Energy Technology Data Exchange (ETDEWEB)

1986-12-01

Utility and industrial firms currently using oil- and gas-fired boilers have an interest in substitution of coal for oil and gas as the primary boiler fuel. This interest stems from coal`s two main advantages over oil and gas-lower cost and security of supply. Recent efforts in the area of coal conversion have been directed to converting oil- and gas- fired boilers which were originally designed for coal-firing or were designed with some coal-firing capability. Boilers designed exclusively for oil- or gas-firing have not been considered viable candidates for coal conversion because they generally require a significant capacity derating and extensive and costly modifications. As a result, conversion of boilers in this class to coal-firing has generally been considered unattractive. Renewed interest in the prospects for converting boilers designed exclusively for oil- and gas-firing to coal firing has centered around the concept of using ``ultra fine`` coal as opposed to ``conventional grind`` pulverized coal. The main distinction being the finer particle size to which the former is ground. This fuel type may have characteristics which ameliorate many of the boiler problems normally associated with pulverized coal-firing. The overall concept for ultrafine coal utilization is based on a regional large preparation plant with distribution of a ready to fire fuel directly to many small users. This differs from normal practice in which final coal sizing is performed in pulverizers at the user`s site.

Air extraction in gas turbines burning coal-derived gas

Energy Technology Data Exchange (ETDEWEB)

Yang, Tah-teh; Agrawal, A.K.; Kapat, J.S.

1993-11-01

In the first phase of this contracted research, a comprehensive investigation was performed. Principally, the effort was directed to identify the technical barriers which might exist in integrating the air-blown coal gasification process with a hot gas cleanup scheme and the state-of-the-art, US made, heavy-frame gas turbine. The guiding rule of the integration is to keep the compressor and the expander unchanged if possible. Because of the low-heat content of coal gas and of the need to accommodate air extraction, the combustor and perhaps, the flow region between the compressor exit and the expander inlet might need to be modified. In selecting a compressed air extraction scheme, one must consider how the scheme affects the air supply to the hot section of the turbine and the total pressure loss in the flow region. Air extraction must preserve effective cooling of the hot components, such as the transition pieces. It must also ensure proper air/fuel mixing in the combustor, hence the combustor exit pattern factor. The overall thermal efficiency of the power plant can be increased by minimizing the total pressure loss in the diffusers associated with the air extraction. Therefore, a study of airflow in the pre- and dump-diffusers with and without air extraction would provide information crucial to attaining high-thermal efficiency and to preventing hot spots. The research group at Clemson University suggested using a Griffith diffuser for the prediffuser and extracting air from the diffuser inlet. The present research establishes that the analytically identified problems in the impingement cooling flow are factual. This phase of the contracted research substantiates experimentally the advantage of using the Griffith diffuser with air extraction at the diffuser inlet.

Comparative assessment of severe accident risks in the coal, oil and natural gas chains

International Nuclear Information System (INIS)

Burgherr, Peter; Eckle, Petrissa; Hirschberg, Stefan

2012-01-01

This study compared severe accident risks of fossil energy chains (coal, oil and natural gas), based on the historical experience contained in the comprehensive database ENSAD. Considered risk indicators focused on human health impacts, i.e., fatality rates and maximum consequences were calculated for a broad range of country groups. Generally, expected fatality rates were lowest for natural gas, intermediate for oil and highest for coal. Concerning maximum consequences of a single accident, natural gas also performed best, followed by coal, whereas accidents in the oil chain can claim significantly more fatalities. In general, OECD and EU 27 ranked top, while non-OECD countries and China in the case of coal were worst. The consideration of numerous additional country groups enabled a more detailed differentiation within the main bounding groups. Furthermore, differences among country groups are distinctly decreasing from coal to oil and natural gas, both for fatality rates and maximum consequences. The use of import adjusted-fatality rates indicates that fatality risks in supply countries are an essential aspect to understand how specific risk reduction strategies may affect other components of energy security, and thus tradeoffs and compromises are necessary. Finally, the proposed fatality risk score for fossil chains (FRS F ) allows a comparison of the combined accident risk for the considered fossil energy chains across individual countries, which can be visualized using risk mapping.

A study on different thermodynamic cycle schemes coupled with a high temperature gas-cooled reactor

International Nuclear Information System (INIS)

Qu, Xinhe; Yang, Xiaoyong; Wang, Jie

2017-01-01

Highlights: • The features of three different power generation schemes, including closed Brayton cycle, non-reheating combined cycle and reheating combined cycle, coupled with high temperature gas-cooled reactor (HTGR) were investigated and compared. • The effects and mechanism of reactor core outlet temperature, compression ratio and other key parameters over cycle characteristics were analyzed by the thermodynamic models.. • It is found that reheated combined cycle has the highest efficiency. Reactor outlet temperature and main steam parameters are key factors to improve the cycle’s performance. - Abstract: With gradual increase in reactor outlet temperature, the efficient power conversion technology has become one of developing trends of (very) high temperature gas-cooled reactors (HTGRs). In this paper, different cycle power generation schemes for HTGRs were systematically studied. Physical and mathematical models were established for these three cycle schemes: closed Brayton cycle, simple combined cycle, and reheated combined cycle. The effects and mechanism of key parameters such as reactor core outlet temperature, reactor core inlet temperature and compression ratio on the features of these cycles were analyzed. Then, optimization results were given with engineering restrictive conditions, including pinch point temperature differences. Results revealed that within the temperature range of HTGRs (700–900 °C), the reheated combined cycle had the highest efficiency, while the simple combined cycle had the lowest efficiency (900 °C). The efficiencies of the closed Brayton cycle, simple combined cycle and reheated combined cycle are 49.5%, 46.6% and 50.1%, respectively. These results provide insights on the different schemes of these cycles, and reveal the effects of key parameters on performance of these cycles. It could be helpful to understand and develop a combined cycle coupled with a high temperature reactor in the future.

Mathematical modelling of flue gas tempered flames produced from pulverised coal fired with oxygen

Energy Technology Data Exchange (ETDEWEB)

Breussin, A.; Weber, R.; Kamp, W.L. van de

1997-10-01

The combustion of pulverised coal in conventional utility boilers contributes significantly to global CO{sub 2} emissions. Because atmospheric air is used as the combustion medium, the exhaust gases of conventional pulverised coal fired utility boilers contain approximately 15 % CO{sub 2}. This relatively low concentration makes separating and recovering CO{sub 2} a very energy-intensive process. This process can be simplified if N{sub 2} is eliminated from the comburent before combustion by firing the pulverised coal with pure oxygen. However, this concept will result in very high flames temperatures. Flue gas recirculation can be used to moderate the flame temperature, whilst generating a flue gas with a CO{sub 2} concentration of 95 %. In this presentation, both experimental and modelling work will be described. The former deals with identifying the issues related to the combustion of pulverised coal in simulated turbine exhaust gas, particularly with respect to stability, burnout and pollutant emissions. The second part of this presentation describes mathematical modelling of type 2 as well as type 1 swirling pulverised coal flames. Future work will concentrate on high CO{sub 2} levels environments. (orig.)

Report for fiscal 1995 by Coal Gasification Committee; 1995 nendo sekitan gas ka iinkai hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

This is a summary primarily of the distributed material. As of December 14, 1995, the 200t/d pilot plant for power generation by entrained bed coal gasification records a total coal gasification operation time of 4,485 hours with an accumulated amount of power generation of 9,227MWh. A large combustor is tested, and it is found that combustion is stable under a 1/4 load with low NOx emissions. The combustor is sufficiently cooled with a small supply of air. Coal ash and coal, supplied in a constant state for an improved heat recovery efficiency in the development of hydrogen-from-coal technology, are heated to a temperature near their melting points. They are then allowed to impinge at a heat transfer plane simulating a gasifier heat recovery section, and a study is made of the mechanism of ash adhesion, molten or semi-molten, to the heat recovery section. The reduction of the heat transfer coefficient due to added grains is 30-50%, and the reduction is small when the heat transfer pipe surface velocity is high or when the carbon concentration in the grains is high. In another effort, utilization of coal-derived gas as town gas is studied. As for yields as indicated by the Curie gas pyrolyzer, the gas yield increases and liquid yield decreases when the reaction temperature is high. Using a small test unit, it is found that a rise in the hydrogen partial pressure increases the production of both gas and liquid. (NEDO)

Distilling coal

Energy Technology Data Exchange (ETDEWEB)

Blythe, F C

1914-09-14

In the destructive distillation of bituminous coal, heavy hydrocarbon oil, such as petroleum, kerosine, shale oil, and heavy tar oil, obtained in some cases during the process, is added to the coal, which is then distilled under pressure and at a comparatively low temperature regulated so as to produce a large proportion of hydrocarbon oils and a small proportion of permanent gas. In one method, about 5 to 10 parts of hydrocarbon oil are mixed with 100 parts of crushed or ground coal, and the mixture is heated in a closed vessel, provided in some cases with an agitator, under a pressure of about 60 lb/in/sup 2/, and the temperature may be gradually raised to 350/sup 0/C and then to about 500/sup 0/C. The heating may be by means of superheated steam with or without external heat.

Method of gas emission control for safe working of flat gassy coal seams

Science.gov (United States)

Vinogradov, E. A.; Yaroshenko, V. V.; Kislicyn, M. S.

2017-10-01

The main problems at intensive flat gassy coal seam longwall mining are considered. For example, mine Kotinskaja JSC “SUEK-Kuzbass” shows that when conducting the work on the gassy coal seams, methane emission control by means of ventilation, degassing and insulated drain of methane-air mixture is not effective and stable enough. It is not always possible to remove the coal production restrictions by the gas factor, which leads to financial losses because of incomplete using of longwall equipment and the reduction of the technical and economic indicators of mining. To solve the problems, the authors used a complex method that includes the compilation and analysis of the theory and practice of intensive flat gassy coal seam longwall mining. Based on the results of field and numerical researches, the effect of parameters of technological schemes on efficiency of methane emission control on longwall panels, the non-linear dependence of the permissible according to gas factor longwall productivity on parameters of technological schemes, ventilation and degassing during intensive mining flat gassy coal seams was established. The number of recommendations on the choice of the location and the size of the intermediate section of coal heading to control gassing in the mining extracted area, and guidelines for choosing the parameters of ventilation of extracted area with the help of two air supply entries and removal of isolated methane-air mixture are presented in the paper. The technological scheme, using intermediate entry for fresh air intake, ensuring effective management gassing and allowing one to refuse from drilling wells from the surface to the mined-out space for mining gas-bearing coal seams, was developed.

Estimating externalities of coal fuel cycles. Report No. 3 on the external costs and benefits of fuel cycles: a study by the US Department of Energy and the Commission of the European Communities

International Nuclear Information System (INIS)

1994-09-01

The report, one of a series of eight reports, is primarily about a methodology for estimating coal fuel cycle externalities. The study considered the stages of a typical coal fuel cycle and identified the more important ones: coal mining coal transportation, and electric power generation. Chapter headings are: introduction; alternative contexts for the study; prior studies of damages and benefits; methods development; organization, interpretation and use of results; reference technology and sites; priority impact-pathways for the coal fuel cycle; estimating the externalities of coal mining; estimating coal transportation externalities; estimating-the externalities of electric power generation; tabulation of numerical results; and fundings, conclusions, and recommendations. The study demonstrated the application of the damage function approach to estimating the externalities of coal fuel cycles. A number of analytical methods were applied within that framework to several impact-pathways. 580 refs., 40 figs., 130 tabs., 3 apps

Thermodynamic analyses of solar thermal gasification of coal for hybrid solar-fossil power and fuel production

International Nuclear Information System (INIS)

Ng, Yi Cheng; Lipiński, Wojciech

2012-01-01

Thermodynamic analyses are performed for solar thermal steam and dry gasification of coal. The selected types of coal are anthracite, bituminous, lignite and peat. Two model conversion paths are considered for each combination of the gasifying agent and the coal type: production of the synthesis gas with its subsequent use in a combined cycle power plant to generate power, and production of the synthesis gas with its subsequent use to produce gasoline via the Fischer–Tropsch synthesis. Replacement of a coal-fired 35% efficient Rankine cycle power plant and a combustion-based integrated gasification combined cycle power plant by a solar-based integrated gasification combined cycle power plant leads to the reduction in specific carbon dioxide emissions by at least 47% and 27%, respectively. Replacement of a conventional gasoline production process via coal gasification and a subsequent Fischer–Tropsch synthesis with gasoline production via solar thermal coal gasification with a subsequent Fischer–Tropsch synthesis leads to the reduction in specific carbon dioxide emissions by at least 39%. -- Highlights: ► Thermodynamic analyses for steam and dry gasification of coal are presented. ► Hybrid solar-fossil paths to power and fuels are compared to those using only combustion. ► Hybrid power production can reduce specific CO 2 emissions by more than 27%. ► Hybrid fuel production can reduce specific CO 2 emissions by more than 39%.

Method for enhancing the desulfurization of hot coal gas in a fluid-bed coal gasifier

Science.gov (United States)

Grindley, Thomas

1989-01-01

A process and apparatus for providing additional desulfurization of the hot gas produced in a fluid-bed coal gasifier, within the gasifier. A fluid-bed of iron oxide is located inside the gasifier above the gasification bed in a fluid-bed coal gasifier in which in-bed desulfurization by lime/limestone takes place. The product gases leave the gasification bed typically at 1600.degree. to 1800.degree. F. and are partially quenched with water to 1000.degree. to 1200.degree. F. before entering the iron oxide bed. The iron oxide bed provides additional desulfurization beyond that provided by the lime/limestone.

Study on the supercritical CO2 power cycles for landfill gas firing gas turbine bottoming cycle

International Nuclear Information System (INIS)

Kim, Min Seok; Ahn, Yoonhan; Kim, Beomjoo; Lee, Jeong Ik

2016-01-01

In this paper, a comparison of nine supercritical carbon dioxide (S-CO 2 ) bottoming power cycles in conjunction with a topping cycle of landfill gas (LFG) fired 5MWe gas turbine is presented. For the comparison purpose, a sensitivity study of the cycle design parameters for nine different cycles was conducted and each cycle thermodynamic performance is evaluated. In addition, the cycle performance evaluation dependency on the compressor inlet temperature variation is performed to investigate how S-CO 2 cycles sensitive to the heat sink temperature variation. Furthermore, the development of new S-CO 2 cycle layouts is reported and the suggested cycles' performances are compared to the existing cycle layouts. It was found that a recompression cycle is not suitable for the bottoming cycle application, but a partial heating cycle has relatively higher net produced work with a simple layout and small number of components. Although a dual heated and flow split cycle has the highest net produced work, it has disadvantages of having numerous components and complex process which requires more sophisticated operational strategies. This study identified that the recuperation process is much more important than the intercooling process to the S-CO 2 cycle design for increasing the thermal efficiency and the net produced work point of view. - Highlights: • Study of nine S-CO 2 power cycle layouts for a small scale landfill gas power generation application. • Development of new S-CO 2 cycle layouts. • Sensitivity analysis of S-CO 2 cycles to evaluate and compare nine cycles' performances.

Medium Btu gas from coal: a possible solution to the U. S. energy crisis

Energy Technology Data Exchange (ETDEWEB)

Taffe, P

1978-03-03

The future of coal gasification in the US, and in particular the potential of the Winkler process, are discussed. The economics and the efficiency of the Winkler process are considered. It is believed that medium Btu gas from coal is a better solution to the US energy crisis than is SNG made from coal.

NOx results from two combustors tested on medium BTU coal gas

Science.gov (United States)

Sherlock, T. P.; Carl, D. E.; Vermes, G.; Schwab, J.; Notardonato, J. J.

1982-01-01

The results of tests of two combustor configurations using coal gas from a 25 ton/day fluidized bed coal gasifier are reported. The trials were run with a ceramic-lined, staged rich/lean burner and an integral, all metal multiannular swirl burner (MASB) using a range of temperatures and pressures representative of industrial turbine inlet conditions. A lean mixture was examined at 104, 197, and 254 Btu/Scf, yielding NO(x) emissions of 5, 20, and 70 ppmv, respectively. The MASB was employed only with a gas rated at 220-270 Btu/Scf, producing 80 ppmv NO(x) at rated engine conditions. The results are concluded to be transferrable to current machines. Further tests on the effects of gas composition, the scaling of combustors to utility size, and the development of improved wall cooling techniques and variable geometry are indicated.

Clean Coal Day '93. Hokkaido Seminar; Clean Coal Day '93. Hokkaido Seminar

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-11-01

The titles of the lectures in this record are 1) Coal energy be friendly toward the earth, 2) Future development of coal-fired thermal power generation, 3) Current status of research and development of coalbed methane in the U.S., and 4) PFBC (pressurized fluidized bed combustion combined cycle) system. Under title 1), the reason is explained why coal is back as an energy source and is made much of. The actualities of coal being labelled as a dirty energy source are explained. The rapid growth of demand for coal in Asia is commented on and what is expected of clean coal technology is stated. Under title 2), it is predicted that atomic energy, LNG (liquefied natural gas), and coal will be the main energy sources for electric power in Japan. Under title 3), it is stated that 10% of America's total amount of methane production is attributable to coal mining, that methane is the cleanest of the hydrocarbon fuels although it is a pollution source from an environmental point of view, and that it is therefore reasonable to have its collection and utilization placed in the domain of clean coal technology. Under title 4), a PFBC system to serve as the No. 3 machine for the Tomahigashi-Atsuma power plant is described. (NEDO)

Coal waste slurries as a fuel for integrated gasification combined cycle plants

Directory of Open Access Journals (Sweden)

Lutynski Marcin A.

2016-01-01

Full Text Available The article summarizes recent development in integrated gasification combined cycle technology and lists existing and planned IGCC plants. A brief outlook on the IGCC gasification technology is given with focus on entrained-flow gasifiers where the low-quality coal waste slurry fuel can be used. Desired properties of coal and ash for entrained-flow gasifiers are listed. The coal waste slurries, which were deposited at impoundments in Upper Silesian Coal Basin, were considered as a direct feed for such gasifiers. The average ash content, moisture content and lower heating value were analysed and presented as an average values. Entrained-flow commercial gasifiers can be considered as suitable for the coal slurry feed, however the ash content of coal slurries deposited in impoundments is too high for the direct use as the feed for the gasifiers. The moisture content of slurries calculated on as received basis meets the requirements of entrained-flow slurry feed gasifiers. The content of fines is relatively high which allow to use the slurries in entrained-flow gasifiers.

Analysis of CO2 Separation from Flue Gas, Pipeline Transportation, and Sequestration in Coal

Energy Technology Data Exchange (ETDEWEB)

Eric P. Robertson

2007-09-01

This report was written to satisfy a milestone of the Enhanced Coal Bed Methane Recovery and CO2 Sequestration task of the Big Sky Carbon Sequestration project. The report begins to assess the costs associated with separating the CO2 from flue gas and then injecting it into an unminable coal seam. The technical challenges and costs associated with CO2 separation from flue gas and transportation of the separated CO2 from the point source to an appropriate sequestration target was analyzed. The report includes the selection of a specific coal-fired power plant for the application of CO2 separation technology. An appropriate CO2 separation technology was identified from existing commercial technologies. The report also includes a process design for the chosen technology tailored to the selected power plant that used to obtain accurate costs of separating the CO2 from the flue gas. In addition, an analysis of the costs for compression and transportation of the CO2 from the point-source to an appropriate coal bed sequestration site was included in the report.

Technical surveys on MHD combustors. Surveys on incorporation of pressurized coal partial combustion furnaces; MHD combustor gijutsu chosa. Kaatsugata sekitan bubun nenshoro no donyu chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

1991-03-01

The pressurized coal partial combustion (PCPC) furnace is surveyed/studied for its incorporation in MHD generation. The technical development of the atmospheric CPC has been basically completed, and the concept is demonstrated using a test system of commercial size. Many techniques developed for the atmospheric CPC are applicable to the PCPC system. These include structures of the CPC furnace walls, and slag handling and simulation techniques. Combination of PFBC with PCPC or IGCC can bring about many merits, e.g., enhanced efficiency and abated NOx emissions for the combined cycle power generation. These topping cycles, therefore, should be developed in the early stage. MHD power generation is one of the concepts that can enhance efficiency. In particular, the techniques for closed cycle MHD generation have notably advanced recently. The PCPC techniques are useful for coal combustors for MHD generation. Full-scale development works for the direct coal combustion gas turbine systems have been just started for the IGCC systems of the next generation, and the PCPC-related techniques are expected to serve as the central techniques for these turbine systems. (NEDO)

First status seminar `Druckflamm`. Development of a coal-fuelled combined cycle process with liquid ash separation. Conference report; Erstes Statusseminar `Druckflamm`. Entwicklung eines kohlegefeuerten Gas- und Dampfturbinenprozesses mit Fluessigascheabscheidung. Tagungsband

Energy Technology Data Exchange (ETDEWEB)

Hannes, K. [ed.

1999-09-01

Six industrial enterprises in the Ruhr, plus several universities and national rsearch centers are working on the `Druckflamm` process of pressurized coal dust combustion, which is described in this status report and is scheduled to be implementable within the next 20 years. To this end, an experimental facility (DKSF) was constructed at Dorsten. The plant works by a coal-fuelled combined cycle process in which the flue gas can be led directly onto a gas turbine after purification. This means that the flue gas must be free of particulate materials and noxious vapours, i.e. a particle size of less than 3 mg/m{sup 3}, a particle diameter of less than 3 {mu}m and an alkali concentration of less than 1 ppm. The Dorsten plant is fuelled with coal; it has a thermal capacity of 1 MW and can be operated at pressures up to 20 bar. The contribution presents an outline drawing of the plant and a survey of the results and information obtained so far. Material problems and methods of measurement are reported separately. The fuel coals were of different composition, with slag flow points between 1200 and 1400 degrees centigrade. [Deutsch] Im Ruhrgebiet wird an einem neuen Verfahren zur Verstromung von Steinkohle gearbeitet. Es soll in etwa 20 Jahren mit einem neuen Kraftwerkstyp einsetzbar sein. Kennzeichen dieses Verfahrens sind ein hoher Wirkungsgrad von mehr als 50% und eine geringe CO{sub 2}-Emission. Entwickelt wird das ``Druckkohlenstaubfeuerung`` genannte Projekt von sechs Industrieunternehmen. Zusaetzlich arbeiten an diesem Thema weitere Unternehmen sowie Universitaeten und Grossforschungseinrichtungen unter dem Arbeitstitel ``Druckflamm``. Bisherige Ergebnisse der grundlegenden Entwicklungsarbeiten sind in diesem Statusbericht zusammengefasst. Ziel des Verbundprojektes Druckkohlenstaubfeuerung (DKSF) in Dorsten ist, einen GUD-Prozess auf Kohlebasis zu entwickeln, der dadurch charakterisiert ist, dass das Rauchgas nach Reinigung unmittelbar auf eine Gasturbine geleitet

Gas: the great depression?

International Nuclear Information System (INIS)

Mary, Olivier

2013-01-01

This article describes the worrying situation of gas industry: thermal plants are being closed one after the other because of the concurrence of renewable energies and of consumption decrease. European gas industries outline that gas plants could be used for back-up production in case of consumption peaks, and criticize subsidies awarded to renewable energies. Several factors impact this situation: decrease of gross prices, decrease of energy consumption due to a better energy efficiency, development of shale gas production in the USA and in Canada, revival of coal plants (coal is now competitive with respect to gas, and CO 2 is very cheap on the ETS)

Coal seam has boom - powering North Queensland industrial growth

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-06-01

Reduced operating costs, lower greenhouse gas emissions and security of supply are being cited by North Queensland industry leaders as the reasons for investing more than A$550 million to expand operations and convert to coal seam gas as their preferred fuel source. The article, by Enertrade, reports that just a few months after commissioning its North Queensland Gas Pipeline to transport coal seam gas from Moranbah to Townsville, Enertrade has signed contracts that will see combined cycle gas-fired baseload electricity generated in Townsville and the Queensland Nickel Refinery, and Xstrata Copper Refinery switch from liquid fuels to gas. The development has been driven by state government policy that 13% of Queensland's electricity be sourced from gas-fired power generation from 1 January 2005. Further information is available from Enertrade on Tel +617 3331 9929. 2 photos.

A nuclear gas turbine perspective: The indirect cycle (IDC) offers a practical solution

International Nuclear Information System (INIS)

McDonald, C.F.

1996-01-01

The current generation of nuclear power plants are based on light water reactors and steam cycle power conversion systems. This coupling yields a power plant efficiency of less than 30% when dry-cooled. By utilizing a higher temperature heat source, and a more efficient prime-mover, the next generation of nuclear power plants have the potential for an efficiency of close to 50%, with attendant fuel savings and reduced heat rejection to the environment. The nuclear closed Brayton cycle (NCBC) gas turbine plant involves the coupling of a high temperature reactor (HTR) and a high efficiency helium gas turbine. Studies over many years have shown the merits of an indirect cycle (IDC) approach in which an intermediate heat exchanger is used to transfer the reactor thermal energy to the prime-mover. The major advantages of this include the following: (1) multipurpose nuclear heat source; (2) gas turbine operation in a clean non-nuclear environment; (3) power conversion system simplicity; and (4) maximum utilization of existing technology. An additional factor, which may dominate the above is that the IDC approach is in concert with the only active gas-cooled reactor program remaining in the world, namely a high temperature test reactor (HTTR) under construction in Japan, the culmination of which will be the demonstration of a viable high temperature nuclear heat source. The major theme of this paper is that the IDC nuclear gas turbine offers a practical NCBC power plant concept for operation in the second or third decades of the 21st century

The Efficiency Improvement by Combining HHO Gas, Coal and Oil in Boiler for Electricity Generation

Directory of Open Access Journals (Sweden)

Chia-Nan Wang

2017-02-01

Full Text Available Electricity is an essential energy that can benefit our daily lives. There are many sources available for electricity generation, such as coal, natural gas and nuclear. Among these sources, coal has been widely used in thermal power plants that account for about 41% of the worldwide electricity supply. However, these thermal power plants are also found to be a big pollution source to our environment. There is a need to explore alternative electricity sources and improve the efficiency of electricity generation. This research focuses on improving the efficiency of electricity generation through the use of hydrogen and oxygen mixture (HHO gas. In this research, experiments have been conducted to investigate the combined effects of HHO gas with other fuels, including coal and oil. The results show that the combinations of HHO with coal and oil can improve the efficiency of electricity generation while reducing the pollution to our environment.

Moderate temperature gas purification system: Application to high calorific coal-derived fuel

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, M.; Shirai, H.; Nunokawa, M. [Central Research Institute of Electric Power Industry, Kanagawa (Japan)

2008-01-15

Simultaneous removal of dust, alkaline and alkaline-earth metals, halides and sulfur compounds is required to enlarge application of coal-derived gas to the high-temperature fuel cells and the fuel synthesis through chemical processing. Because high calorific fuel gas, such as oxygen-blown coal gas, has high carbon monoxide content, high-temperature (above 450{sup o}C) gas purification system is always subjected to the carbon deposition. We suggest moderate temperature (around 300{sup o}C) operation of the gas purification system to avoid the harmful disproportionation reaction and efficient removal of the various contaminants. Because the reaction rate is predominant to the performance of contaminant removal in the moderate temperature gas purification system, we evaluated the chemical removal processes; performance of the removal processes for halides and sulfur compounds was experimentally evaluated. The halide removal process with sodium aluminate sorbent had potential performance at around 300{sup o}C. The sulfur removal process with zinc ferrite sorbent was also applicable to the temperature range, though the reaction kinetics of the sorbent is essential to be approved.