Study of the equilibrium of air-blown gasification of biomass to coal evolution fuels

International Nuclear Information System (INIS)

Biagini, Enrico

2016-01-01

Highlights: • Equilibrium model validated for coals, torrefied/green biomasses, in different gasifiers. • Maps of syngas composition, LHV and CGE for ER = 0–0.6, T = 500–2000 K, EBP = 0.004–0.158. • Effect of unconverted carbon, fuel moisture and overoxidation quantified. • Parameters for the maximum efficiency determined as functions of EBP. • EBP proven to be a good parameter for the quantitative comparison of different fuels. - Abstract: A non-stoichiometric equilibrium model based on the minimization of the Gibbs free energy was used to study the isothermal and adiabatic air-blown gasification of solid fuels on a carbonization curve from fossil (hard/brown coals, peat) to renewable (green biomasses and cellulose) fuels, including torrefied biofuels. The maps of syngas composition, heating value and process efficiency were provided as functions of equivalent ratio (oxygen-to-fuel ratio) in the range 0–0.6, temperature in 500–2000 K, and a fuel parameter, which allowed different cases to be quantitatively compared. The effect of fuel moisture, unconverted carbon and conditions to limit the tar formation was also studied. Cold gas efficiency >0.75 can be achieved for coals at high temperature, using entrained beds (which give low unconverted carbon), and improved by moisture/added steam. The bigger efficiency of green biomasses is only potential, as the practical limits (high temperature required to limit tar formation, moisture content and unconverted carbon in small gasifiers) strongly reduce the gasification performance. Torrefied biomasses (and plastics having an intermediate fuel parameter between coals and green biomasses) can attain high efficiency also in real conditions. The results shown in this work can be useful to evaluate the most promising feedstock (depending on its composition and possible pre-treatment/upgrading), define the operating conditions for maximizing the syngas heating value or the global efficiency, assess the

Slag Behavior in Gasifiers. Part I: Influence of Coal Properties and Gasification Conditions

Directory of Open Access Journals (Sweden)

Ping Wang

2013-02-01

Full Text Available In the entrained-flow gasifiers used in integrated gasification combined cycle (IGCC plants, the majority of mineral matter transforms to liquid slag on the wall of the gasifier and flows out the bottom. However, a small fraction of the mineral matter is entrained (as fly ash with the raw syngas out of the gasifier to downstream processing. This molten/sticky fly ash could cause fouling of the syngas cooler. To improve gasification availability through better design and operation of the gasification process, a better understanding of slag behavior and the characteristics of the slagging process is needed. Char/ash properties, gas compositions in the gasifier, the gasifier wall structure, fluid dynamics, and plant operating conditions (mainly temperature and oxygen/carbon ratio all affect slagging behavior. Because coal has varying ash content and composition, different operating conditions are required to maintain the slag flow and limit problems downstream. In Part I, we review the main types and the operating conditions of entrained-flow gasifiers and coal properties used in IGCC plants; we identify and discuss the key coal ash properties and the operating conditions impacting slag behavior; finally, we summarize the coal quality criteria and the operating conditions in entrained-flow gasifiers. In Part II, we discuss the constitutive modeling related to the rheological studies of slag flow.

Development and Application of SKSSIM Simulation Software for the Oxygen Bottom Blown Copper Smelting Process

Directory of Open Access Journals (Sweden)

Qinmeng Wang

2017-10-01

Full Text Available The oxygen bottom blown copper smelting process (SKS process is a newly developed intense smelting process, which has been widely applied to copper production in China. A multiphase equilibrium model for the SKS process was established based on its mechanism characteristics and the principle of Gibbs energy minimization, and an efficient simulation software—SKSSIM (SKS Simulation—was developed based on the model. Industrial data from the SKS process were used to compare with the calculated data from the SKSSIM software. The calculated data on the compositions of slag and matte as well as the distribution ratios of minor elements (such as Pb, Zn, As, Sb and Bi among the slags, mattes and off-gases were in good agreement with the actual plant data. Accordingly, the SKSSIM simulation software has the potentail to be used for the prediction of smelting production and for optimizing the operating parameters of the SKS process.

Processing precious metals in a top-blown rotary converter

Science.gov (United States)

Whellock, John G.; Matousek, Jan W.

1990-09-01

Copper-nickel/platinum-palladium flotation concentrates produced by the Stillwater Mining Company were smelted and refined in an integrated pilot plant consisting of a submerged-arc electric furnace and top-blown rotary converter. The conversion of high-iron electric furnace mattes was achieved with apparent oxygen efficiencies in excess of 100 percent. Platinum and palladium recoveries averaged 99 percent, and copper and nickel recoveries were 94 percent.

Gasifier selection, design and gasification of oil palm fronds with preheated and unheated gasifying air.

Science.gov (United States)

Guangul, Fiseha M; Sulaiman, Shaharin A; Ramli, Anita

2012-12-01

Oil palm frond biomass is abundantly available in Malaysia, but underutilized. In this study, gasifiers were evaluated based on the available literature data and downdraft gasifiers were found to be the best option for the study of oil palm fronds gasification. A downdraft gasifier was constructed with a novel height adjustment mechanism for changing the position of gasifying air and steam inlet. The oil palm fronds gasification results showed that preheating the gasifying air improved the volumetric percentage of H(2) from 8.47% to 10.53%, CO from 22.87% to 24.94%, CH(4) from 2.02% to 2.03%, and higher heating value from 4.66 to 5.31 MJ/Nm(3) of the syngas. In general, the results of the current study demonstrated that oil palm fronds can be used as an alternative energy source in the energy diversification plan of Malaysia through gasification, along with, the resulting syngas quality can be improved by preheating the gasifying air. Copyright © 2012 Elsevier Ltd. All rights reserved.

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.

Comparison of pulp-mill-integrated hydrogen production from gasified black liquor with stand-alone production from gasified biomass

International Nuclear Information System (INIS)

Andersson, E.; Harvey, S.

2007-01-01

When gasified black liquor is used for hydrogen production, significant amounts of biomass must be imported. This paper compares two alternative options for producing hydrogen from biomass: (A) pulp-mill-integrated hydrogen production from gasified back liquor; and (B) stand-alone production of hydrogen from gasified biomass. The comparison assumes that the same amount of biomass that is imported in Alternative A is supplied to a stand-alone hydrogen production plant and that the gasified black liquor in Alternative B is used in a black liquor gasification combined cycle (BLGCC) CHP unit. The comparison is based upon equal amounts of black liquor fed to the gasifier, and identical steam and power requirements for the pulp mill. The two systems are compared on the basis of total CO 2 emission consequences, based upon different assumptions for the reference energy system that reflect different societal CO 2 emissions reduction target levels. Ambitions targets are expected to lead to a more CO 2 -lean reference energy system, in which case hydrogen production from gasified black liquor (Alternative A) is best from a CO 2 emissions' perspective, whereas with high CO 2 emissions associated with electricity production, hydrogen from gasified biomass and electricity from gasified black liquor (Alternative B) is preferable. (author)

Liquid CO₂/Coal Slurry for Feeding Low Rank Coal to Gasifiers

Energy Technology Data Exchange (ETDEWEB)

Marasigan, Jose [Electric Power Research Institute, Inc., Palo Alto, CA (United States); Goldstein, Harvey [Electric Power Research Institute, Inc., Palo Alto, CA (United States); Dooher, John [Electric Power Research Institute, Inc., Palo Alto, CA (United States)

2013-09-30

This study investigates the practicality of using a liquid CO₂/coal slurry preparation and feed system for the E-Gas™ gasifier in an integrated gasification combined cycle (IGCC) electric power generation plant configuration. Liquid CO₂ has several property differences from water that make it attractive for the coal slurries used in coal gasification-based power plants. First, the viscosity of liquid CO₂ is much lower than water. This means it should take less energy to pump liquid CO₂ through a pipe compared to water. This also means that a higher solids concentration can be fed to the gasifier, which should decrease the heat requirement needed to vaporize the slurry. Second, the heat of vaporization of liquid CO₂ is about 80% lower than water. This means that less heat from the gasification reactions is needed to vaporize the slurry. This should result in less oxygen needed to achieve a given gasifier temperature. And third, the surface tension of liquid CO₂ is about 2 orders of magnitude lower than water, which should result in finer atomization of the liquid CO₂ slurry, faster reaction times between the oxygen and coal particles, and better carbon conversion at the same gasifier temperature. EPRI and others have recognized the potential that liquid CO₂ has in improving the performance of an IGCC plant and have previously conducted systemslevel analyses to evaluate this concept. These past studies have shown that a significant increase in IGCC performance can be achieved with liquid CO₂ over water with certain gasifiers. Although these previous analyses had produced some positive results, they were still based on various assumptions for liquid CO₂/coal slurry properties.

Commercial demonstration of atmospheric medium BTU fuel gas production from biomass without oxygen the Burlington, Vermont Project

Energy Technology Data Exchange (ETDEWEB)

Rohrer, J.W. [Zurn/NEPCO, South Portland, MA (United States); Paisley, M. [Battelle Laboratories, Columbus, OH (United States)

1995-12-31

The first U.S. demonstration of a gas turbine operating on fuel gas produced by the thermal gasification of biomass occurred at Battelle Columbus Labs (BCL) during 1994 using their high throughput indirect medium Btu gasification Process Research Unit (PRU). Zurn/NEPCO was retained to build a commercial scale gas plant utilizing this technology. This plant will have a throughput rating of 8 to 12 dry tons per hour. During a subsequent phase of the Burlington project, this fuel gas will be utilized in a commercial scale gas turbine. It is felt that this process holds unique promise for economically converting a wide variety of biomass feedstocks efficiently into both a medium Btu (500 Btu/scf) gas turbine and IC engine quality fuel gas that can be burned in engines without modification, derating or efficiency loss. Others are currently demonstrating sub-commercial scale thermal biomass gasification processes for turbine gas, utilizing both atmospheric and pressurized air and oxygen-blown fluid bed processes. While some of these approaches hold merit for coal, there is significant question as to whether they will prove economically viable in biomass facilities which are typically scale limited by fuel availability and transportation logistics below 60 MW. Atmospheric air-blown technologies suffer from large sensible heat loss, high gas volume and cleaning cost, huge gas compressor power consumption and engine deratings. Pressurized units and/or oxygen-blown gas plants are extremely expensive for plant scales below 250 MW. The FERCO/BCL process shows great promise for overcoming the above limitations by utilizing an extremely high throughout circulation fluid bed (CFB) gasifier, in which biomass is fully devolitalized with hot sand from a CFB char combustor. The fuel gas can be cooled and cleaned by a conventional scrubbing system. Fuel gas compressor power consumption is reduced 3 to 4 fold verses low Btu biomass gas.

Experience in a 6.2 MW{sub e} pressurized fluidized bed gasifier with high ash Indian coals

Energy Technology Data Exchange (ETDEWEB)

Viswanathan, G.; Rajasekaran, A.; Periyakaruppan, V.; Krishnamoorthy, S. [Bharat Heavy Electricals Ltd., Tiruchirappalli (India)

2006-07-01

Bharat Heavy Electrical Limited has installed a 165 tons/day air-blown pressurized fluidized bed gasifier (PFBG) as an add-on to their 6.2 MW IGCC demonstration plant and has operated it for more than 4000 hours. Improvements in the gasifier refractory lining, ash extraction and cooling devices, air distribution and temperature measuring devices were incorporated to improve the reliability and performance. Coal with 30-42% ash and high calorific value in the range of 15-20 MJ/kg was used during these operations with crushed coal of 1-4 mm as well as -6 mm coal with fines. Tests were conducted at gasifier pressure of 0.3-1.0 MPa, fluidized bed temperature of 980-1050{sup o}C and at various fluidized velocities and air to steam ratios. Once through carbon conversion efficiency of 90%, cold gas efficiency of 69% and dry gas calorific value of 4.4-4.6 MJ/Nm{sup 3} were obtained. About 15% char in fly ash (with 40% ash coal) was established by TGA. Seal pot system was added for recyling fly ash from the first cyclone to enhance carbon conversion, other parameters and to reduce the char in fly ash to acceptable level. Trends and correlations were established for constituents of gas, carbon conversion efficiency, cold gas efficiency, calorific value of gas and gas yield. BHEL is currently working with a partner to install a 125 MW IGCC plant. The paper elaborates the schematic and constructional details of the PFBG, operating experience and performance. 3 refs., 9 figs.

The R.D.F. gasifier of Florentine area

Energy Technology Data Exchange (ETDEWEB)

Barducci, G. [Studio Tecnico di Ingegneria Ambientale, Firenze (Italy)

1993-12-31

L.E.G. (Low Energy Gas) from large biomass gasification plants, to be used as a fuel for electricity production, is a suitable means for adding value -- from an energetic point of view -- to the R.D.F. (Refuse Derived Fuel) and to the agricultural and forestry residues. R.D.F. can be converted to a clean gas turbine fuel by gasification that consists in a partial combustion with oxygen or air and steam. In that sense it seems worthwhile to analyze the capacity of a gasifier such as the Greve in Chianti`s recirculating fluidized bed gasifier. The world`s first full-scale R.D.F. gasification plant has been designed in Florence; it is now realized in Greve in Chianti and, at the moment, is starting the industrial management. The plant is designed to gasify 200 t/d of pelletized R.D.F. producing about 17.000/19.000 Nmc/h of low energy gas (LEG) with a net calorific value (NCV) of about 5 MJ/Nmc and a total energy content (at the outlet of the gasifiers) of about 7.5 MJ/Nmc. The produced LEG will be partly burned on site for power production while partly will be cooled, dedusted and transported to the kiln of the adjacent cement factory. The design idea of R.D.F. gasification starts from field of waste treatment and recycling and develops new, advanced technical and economical sinergy with the field of industrial production and electric power generation. The gasification of fuels derived from selected wastes (and/or industrial refuse) and the exploitation of the lean gas produced is the most advanced point in the development of heat conversion processes.

Gasification - Status and technology

Energy Technology Data Exchange (ETDEWEB)

Held, Joergen

2012-06-15

In this report gasification and gas cleaning techniques for biomass are treated. The main reason for gasifying biomass is to refine the fuel to make it suitable for efficient CHP production, as vehicle fuel or in industrial processes. The focus is on production of synthesis gas that can be used for production of vehicle fuel and for CHP production. Depending on application different types of gasifiers, gasification techniques and process parameters are of interest. Two gasification techniques have been identified as suitable for syngas generation, mainly due to the fact that they allow the production of a nitrogen free gas out of the gasifier; Indirect gasification and pressurized oxygen-blown gasification For CHP production there are no restrictions on the gas composition in terms of nitrogen and here air-blown gasification is of interest as well. The main challenge when it comes to gas cleaning is related to sulphur and tars. There are different concepts and alternatives to handle sulphur and tars. Some of them are based on conventional techniques with well-proven components that are commercially available while others, more advantageous solutions, still need further development.

Compartment modeling of coal gasification in an entrained flow gasifier: A study on the influence of operating conditions

International Nuclear Information System (INIS)

Kong, Xiangdong; Zhong, Weimin; Du, Wenli; Qian, Feng

2014-01-01

Highlights: • Gasification of Shenfu coal in an industrial Texaco gasifier for syngas production. • An equivalent compartment model is developed using Aspen Plus. • Effects of operating parameters on gasification performance indices are studied. • Choosing a reasonable ROC to enhance the gasification efficiency can be flexible. - Abstract: Coal gasifiers are core components of coal-based polygeneration systems for power and chemical production. To study the effects of operational parameters on the performance of entrained flow coal gasifiers, this paper presents an equivalent compartment model (CM) using the Aspen Plus process simulator. The CM blocking is established based on gasifier flow field analysis, using a number of compartments. A simple configuration of these compartments involving material recirculation should be able to simulate the main flow and provide the temperature and gas component distributions. The model predictions exhibit good agreement with industrial data in the model validation. The influences of the oxygen-to-carbon ratio (ROC) and the coal slurry concentration on the gasification performance are discussed. Within the calculation range, the increase in the coal slurry concentration enhances the yield of the effective compositions in product gas. For a given slurry concentration of 62%, the efficient gas yield is a maximum for ROC of 1.43 kg/kg, whereas the oxygen consumption is a minimum for ROC of 1.37 kg/kg. According to the intended final use, however, choosing a reasonable ROC to obtain a higher efficient syngas yield and lower oxygen consumption can be flexible

Refractory for Black Liquor Gasifiers

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Laing

2005-10-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

CANMET Gasifier Liner Coupon Material Test Report

Energy Technology Data Exchange (ETDEWEB)

Mark Fitzsimmons; Dave Grimmett; Bryan McEnerney

2007-01-31

This report provides detailed test results consisting of test data and post-test inspections from Task 1 ''Cooled Liner Coupon Development and Test'' of the project titled ''Development of Technologies and Capabilities for Coal Energy Resources--Advanced Gasification Systems Development (AGSD)''. The primary objective of this development and test program is to verify that ceramic matrix composite (CMC) liner materials planned for use in an advanced gasifier pilot plant will successfully withstand the environments in a commercial gasifier. Pratt & Whitney Rocketdyne (PWR) designed and fabricated the cooled liner test assembly article that was tested in a slagging gasifier at CANMET Energy Technology Center (CETC-O) in Ottawa, Ontario, Canada. The test program conducted in 2006 met the objective of operating the cooled liner test article at slagging conditions in a small scale coal gasifier at CETC-O for over the planned 100 hours. The test hardware was exposed to at least 30 high temperature excursions (including start-up and shut-down cycles) during the test program. The results of the testing has provided valuable information on gasifier startup and required cooling controls in steady state operation of future advanced gasifiers using similar liners. The test program also provided a significant amount of information in the areas of CMC materials and processing for improved capability in a gasifier environment and insight into CMC liner fabrication that will be essential for near-term advanced gasifier projects.

OUT Success Stories: Biomass Gasifiers

International Nuclear Information System (INIS)

Jones, J.

2000-01-01

The world's first demonstration of an efficient, low-pressure biomass gasifier capable of producing a high-quality fuel is now operating in Vermont. The gasifier converts 200 tons of solid biomass per day into a clean-burning gas with a high energy content for electricity generation

Carbon formation and metal dusting in hot-gas cleanup systems of coal gasifiers

Energy Technology Data Exchange (ETDEWEB)

Judkins, R.R.; Tortorelli, P.F.; Judkins, R.R.; DeVan, J.H.; Wright, I.G. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

1995-11-01

The product gas resulting from the partial oxidation of Carboniferous materials in a gasifier is typically characterized by high carbon and sulfur, but low oxygen, activities and, consequently, severe degradation of the structural and functional materials can occur. The objective of this task was to establish the potential risks of carbon deposition and metal dusting in advanced coal gasification processes by examining the current state of knowledge regarding these phenomena, making appropriate thermochemical calculations for representative coal gasifiers, and addressing possible mitigation methods. The paper discusses carbon activities, iron-based phase stabilities, steam injection, conditions that influence kinetics of carbon deposition, and influence of system operating parameters on carbon deposition and metal dusting.

Development and Testing of Prototype Commercial Gasifier Sensor

Energy Technology Data Exchange (ETDEWEB)

Zelepouga, Serguei [Gas Technology Inst., Des Plaines, IL (United States); Moery, Nathan [Gas Technology Inst., Des Plaines, IL (United States); Wu, Mengbai [Gas Technology Inst., Des Plaines, IL (United States); Saveliev, Alexei [Gas Technology Inst., Des Plaines, IL (United States)

2015-01-31

This report presents the results of the sensor development and testing at the Wabash River gasifier. The project work was initiated with modification of the sensor software (Task 2) to enable real time temperature data acquisition, and to process and provide the obtained gasifier temperature information to the gasifier operators. The software modifications were conducted by the North Carolina State University (NCSU) researchers. The modified software was tested at the Gas Technology Institute (GTI) combustion laboratory to assess the temperature recognition algorithm accuracy and repeatability. Task 3 was focused on the sensor hardware modifications needed to improve reliability of the sensor system. NCSU conducted numerical modeling of the sensor probe’s purging flow. Based on the modeling results the probe purging system was redesigned to prevent carbon particulates deposition on the probe’s sapphire window. The modified design was evaluated and approved by the Wabash representative. The modified gasifier sensor was built and installed at the Wabash River gasifier on May 1 2014. (Task 4) The sensor was tested from the startup of the gasifier on May 5, 2015 until the planned autumn gasifier outage starting in the beginning of October, 2015. (Task 5) The project team successfully demonstrated the Gasifier Sensor system’s ability to monitor gasifier temperature while maintaining unobstructed optical access for six months without any maintenance. The sensor examination upon completion of the trial revealed that the system did not sustain any damage.

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr.; Alireza Rezaie

2003-12-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the materials problems encountered during the operation of low-pressure high-temperature (LFHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

Refractory for Black Liquor Gasifiers

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Alireza Rezaie

2003-12-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the materials problems encountered during the operation of low-pressure high-temperature (LFHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

Refractory for Black Liquor Gasifiers

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Alireza Rezaie; Xiaoting Liang; Musa Karakus; Jun Wei

2005-12-01

The University of Missouri-Rolla identified materials that permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project was to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study attempted to define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials were selected or developed that reacted with the gasifier environment to form protective surfaces in

Refractory for Black Liquor Gasifiers

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Liang

2005-10-01

The University of Missouri-Rolla identified materials that permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project was to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study attempted to define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials were selected/developed that either react with the gasifier environment to form protective surfaces in

Refractory for Black Liquor Gasifiers

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick; Musa Karakus; Alireza Rezaie

2004-03-30

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Liang; Alireza Rezaie

2004-07-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Liang; Alireza Rezaie

2004-10-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Liang; Jun Wei

2005-01-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Liang; Jun Wei

2005-04-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Liang

2005-07-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr.; Alireza Rezaie

2004-04-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the materials problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

TASK 3: PILOT PLANT GASIFIER TESTING

Energy Technology Data Exchange (ETDEWEB)

Fusselman, Steve

2015-11-01

Aerojet Rocketdyne (AR) has developed an innovative gasifier concept incorporating advanced technologies in ultra-dense phase dry feed system, rapid mix injector, and advanced component cooling to significantly improve gasifier performance, life, and cost compared to commercially available state-of-the-art systems. Design, fabrication and initial testing of the pilot plant compact gasifier was completed in 2011 by a development team led by AR. Findings from this initial test program, as well as subsequent gasifier design and pilot plant testing by AR, identified a number of technical aspects to address prior to advancing into a demonstration-scale gasifier design. Key among these were an evaluation of gasifier ability to handle thermal environments with highly reactive coals; ability to handle high ash content, high ash fusion temperature coals with reliable slag discharge; and to develop an understanding of residual properties pertaining to gasification kinetics as carbon conversion approaches 99%. The gasifier did demonstrate the ability to withstand the thermal environments of highly reactive Powder River Basin coal, while achieving high carbon conversion in < 0.15 seconds residence time. Continuous operation with the high ash fusion temperature Xinyuan coal was demonstrated in long duration testing, validating suitability of outlet design as well as downstream slag discharge systems. Surface area and porosity data were obtained for the Xinyuan and Xinjing coals for carbon conversion ranging from 85% to 97%, and showed a pronounced downward trend in surface area per unit mass carbon as conversion increased. Injector faceplate measurements showed no incremental loss of material over the course of these experiments, validating the commercially traceable design approach and supportive of long injector life goals. Hybrid testing of PRB and natural gas was successfully completed over a wide range of natural gas feed content, providing test data to anchor predictions

Mixing Phenomena in a Bottom Blown Copper Smelter: A Water Model Study

Science.gov (United States)

Shui, Lang; Cui, Zhixiang; Ma, Xiaodong; Akbar Rhamdhani, M.; Nguyen, Anh; Zhao, Baojun

2015-03-01

The first commercial bottom blown oxygen copper smelting furnace has been installed and operated at Dongying Fangyuan Nonferrous Metals since 2008. Significant advantages have been demonstrated in this technology mainly due to its bottom blown oxygen-enriched gas. In this study, a scaled-down 1:12 model was set up to simulate the flow behavior for understanding the mixing phenomena in the furnace. A single lance was used in the present study for gas blowing to establish a reliable research technique and quantitative characterisation of the mixing behavior. Operating parameters such as horizontal distance from the blowing lance, detector depth, bath height, and gas flow rate were adjusted to investigate the mixing time under different conditions. It was found that when the horizontal distance between the lance and detector is within an effective stirring range, the mixing time decreases slightly with increasing the horizontal distance. Outside this range, the mixing time was found to increase with increasing the horizontal distance and it is more significant on the surface. The mixing time always decreases with increasing gas flow rate and bath height. An empirical relationship of mixing time as functions of gas flow rate and bath height has been established first time for the horizontal bottom blowing furnace.

Commercial gasifier for IGCC applications study report

Energy Technology Data Exchange (ETDEWEB)

Notestein, J.E.

1990-06-01

This was a scoping-level study to identify and characterize the design features of fixed-bed gasifiers appearing most important for a gasifier that was to be (1) potentially commercially attractive, and (2) specifically intended for us in integrated coal gasification/combined-cycle (IGCC) applications. It also performed comparative analyses on the impact or value of these design features and on performance characteristics options of the whole IGCC system since cost, efficiency, environmental traits, and operability -- on a system basis -- are what is really important. The study also reviewed and evaluated existing gasifier designs, produced a conceptual-level gasifier design, and generated a moderately advanced system configuration that was utilized as the reference framework for the comparative analyses. In addition, technical issues and knowledge gaps were defined. 70 figs., 31 tabs.

Down-flow moving-bed gasifier with catalyst recycle

Science.gov (United States)

Halow, John S.

1999-01-01

The gasification of coal and other carbonaceous materials by an endothermic gasification reaction is achieved in the presence of a catalyst in a down-flow, moving-bed gasifier. Catalyst is removed along with ash from the gasifier and is then sufficiently heated in a riser/burner by the combustion of residual carbon in the ash to volatilize the catalyst. This volatilized catalyst is returned to the gasifier where it uniformly contacts and condenses on the carbonaceous material. Also, the hot gaseous combustion products resulting from the combustion of the carbon in the ash along with excess air are introduced into the gasifier for providing heat energy used in the endothermic reaction.

Carbon formation and metal dusting in advanced coal gasification processes

Energy Technology Data Exchange (ETDEWEB)

DeVan, J.H.; Tortorelli, P.F.; Judkins, R.R.; Wright, I.G.

1997-02-01

The product gases generated by coal gasification systems contain high concentrations of CO and, characteristically, have relatively high carbon activities. Accordingly, carbon deposition and metal dusting can potentially degrade the operation of such gasifier systems. Therefore, the product gas compositions of eight representative gasifier systems were examined with respect to the carbon activity of the gases at temperatures ranging from 480 to 1,090 C. Phase stability calculations indicated that Fe{sub 3}C is stable only under very limited thermodynamic conditions and with certain kinetic assumptions and that FeO and Fe{sub 0.877}S tend to form instead of the carbide. As formation of Fe{sub 3}C is a necessary step in the metal dusting of steels, there are numerous gasifier environments where this type of carbon-related degradation will not occur, particularly under conditions associated with higher oxygen and sulfur activities. These calculations also indicated that the removal of H{sub 2}S by a hot-gas cleanup system may have less effect on the formation of Fe{sub 3}C in air-blown gasifier environments, where the iron oxide phase can exist and is unaffected by the removal of sulfur, than in oxygen-blown systems, where iron sulfide provides the only potential barrier to Fe{sub 3}C formation. Use of carbon- and/or low-alloy steels dictates that the process gas composition be such that Fe{sub 3}C cannot form if the potential for metal dusting is to be eliminated. Alternatively, process modifications could include the reintroduction of hydrogen sulfide, cooling the gas to perhaps as low as 400 C and/or steam injection. If higher-alloy steels are used, a hydrogen sulfide-free gas may be processed without concern about carbon deposition and metal dusting.

Commissioning an Engineering Scale Coal Gasifier

Energy Technology Data Exchange (ETDEWEB)

Reid, Douglas J.; Bearden, Mark D.; Cabe, James E.

2010-07-01

This report explains the development, commissioning, and testing of an engineering scale slagging coal gasifier at PNNL. The initial objective of this project was to commission the gasifier with zero safety incidents. The commissioning work was primarily an empirical study that required an engineering design approach. After bringing the gasifier on-line, tests were conducted to assess the impact of various operating parameters on the synthesis gas (syngas) product composition. The long-term intent of this project is to produce syngas product for use by internal Pacific Northwest National Laboratory (PNNL) researchers in catalyst, materials, and instrumentation development. Future work on the project will focus on improving the reliability and performance of the gasifier, with a goal of continuous operation for greater than 4 hours using coal feedstock. In addition, alternate designs that allow for increased flexibility regarding the fuel sources that can be used for syngas production is desired. Continued modifications to the fuel feed system will be pursued to address these goals. Alternative feed mechanisms such as a coal/methanol slurry are being considered.

Condensate from a two-stage gasifier

DEFF Research Database (Denmark)

Bentzen, Jens Dall; Henriksen, Ulrik Birk; Hindsgaul, Claus

2000-01-01

Condensate, produced when gas from downdraft biomass gasifier is cooled, contains organic compounds that inhibit nitrifiers. Treatment with activated carbon removes most of the organics and makes the condensate far less inhibitory. The condensate from an optimised two-stage gasifier is so clean...... that the organic compounds and the inhibition effect are very low even before treatment with activated carbon. The moderate inhibition effect relates to a high content of ammonia in the condensate. The nitrifiers become tolerant to the condensate after a few weeks of exposure. The level of organic compounds...... and the level of inhibition are so low that condensate from the optimised two-stage gasifier can be led to the public sewer....

Numerical investigation of slag formation in an entrained-flow gasifier

Science.gov (United States)

Zageris, G.; Geza, V.; Jakovics, A.

2018-05-01

A CFD mathematical model for an entrained-flow gasifier is constructed – the model of an actual gasifier is rendered in 3D and appropriately meshed. Then, the turbulent gas flow in the gasifier is modeled with the realizable k-ε approach, taking devolatilization, combustion and coal gasification in account. Various such simulations are conducted, obtaining results for different air inlet positions and by tracking particles of varying sizes undergoing devolatilization and gasification. The model identifies potential problematic zones where most particles collide with the gasifier walls, indicating risk regions where ash deposits could most likely form. In conclusion, effects on the formation of an ash layer of air inlet positioning and particle size allowed in the main gasifier tank are discussed, and viable solutions such as radial inlet positioning for decreasing the amount of undesirable deposits are proposed. We also conclude that the particular chemical reactions that take place inside the gasifier play a significant role in determining how slagging occurs inside a gasifier.

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Jun Wei

2005-03-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

Biomass Gasifier for Computer Simulation; Biomassa foergasare foer Computer Simulation

Energy Technology Data Exchange (ETDEWEB)

Hansson, Jens; Leveau, Andreas; Hulteberg, Christian [Nordlight AB, Limhamn (Sweden)

2011-08-15

This report is an effort to summarize the existing data on biomass gasifiers as the authors have taken part in various projects aiming at computer simulations of systems that include biomass gasification. Reliable input data is paramount for any computer simulation, but so far there is no easy-accessible biomass gasifier database available for this purpose. This study aims at benchmarking current and past gasifier systems in order to create a comprehensive database for computer simulation purposes. The result of the investigation is presented in a Microsoft Excel sheet, so that the user easily can implement the data in their specific model. In addition to provide simulation data, the technology is described briefly for every studied gasifier system. The primary pieces of information that are sought for are temperatures, pressures, stream compositions and energy consumption. At present the resulting database contains 17 gasifiers, with one or more gasifier within the different gasification technology types normally discussed in this context: 1. Fixed bed 2. Fluidised bed 3. Entrained flow. It also contains gasifiers in the range from 100 kW to 120 MW, with several gasifiers in between these two values. Finally, there are gasifiers representing both direct and indirect heating. This allows for a more qualified and better available choice of starting data sets for simulations. In addition to this, with multiple data sets available for several of the operating modes, sensitivity analysis of various inputs will improve simulations performed. However, there have been fewer answers to the survey than expected/hoped for, which could have improved the database further. However, the use of online sources and other public information has to some extent counterbalanced the low response frequency of the survey. In addition to that, the database is preferred to be a living document, continuously updated with new gasifiers and improved information on existing gasifiers.

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

Gasification of municipal solid waste in a downdraft gasifier: Analysis of tar formation

Directory of Open Access Journals (Sweden)

Tabitha Geoffrey Etutu

2016-04-01

Full Text Available In this study, municipal solid waste (MSW from a dumpsite was converted into refuse derived fuel (RDF and used as feedstock for an air-blown gasification process. The gasification process was conducted in a 10 kg.hr -1 downdraft gasifier at different air flow rates of 300, 350, 400, 450 and 550 NL.min1 at atmospheric pressure in order to investigate the quantity and quality of tar formed. It was shown that the increase in the air flow rate from 300 NL.min1 to 550 NL.min1 led to an increase in the oxidation temperature from 719°C to 870°C and an increase in the reduction temperature from 585°C to 750°C, respectively. Tar was reduced from 15 g.Nm3 to 4.7 g.Nm3 respectively. Heavy tar compounds (>C17 e.g. pyrene and phenathrene, decreased with the increase in the light tar compounds (

Design and techno economic evaluation of biomass gasifier for ...

African Journals Online (AJOL)

This paper addresses the design, performance and economic evaluation of biomass based open core downdraft gasifier for industrial process heat application. The gasifier is having feed rate as 90 kg h-1 and producing about 850 MJ h-1 of heat. The gasifier has been installed in M/S Phosphate India Pvt. Limited, Udaipur ...

Gasification processes old and new: a basic review of the major technologies

International Nuclear Information System (INIS)

Breault, R. W.

2010-01-01

This paper has been put together to provide a single source document that not only reviews the historical development of gasification but also compares the process to combustion. It also provides a short discussion on integrated gasification and combined cycle processes. The major focus of the paper is to describe the twelve major gasifiers being marketed today. Some of these are already fully developed while others are in various stages of development. The hydrodynamics and kinetics of each are reviewed along with the most likely gas composition from each of the technologies when using a variety of fuels under different conditions from air blown to oxygen blown and atmospheric pressure to several atmospheres. (author)

Exergetic comparison of two KRW-based IGCC power plants

International Nuclear Information System (INIS)

Tsatsaronis, G.; Tawfik, T.; Lin, L.; Gallaspy, D.T.

1991-01-01

In studies supported by the U.S. Department of Energy and the Electric Power Research Institute, several design configurations of Kellogg-Rust-Westinghouse (KRW)-based Integrated Gasification-Combined-Cycle (IGCC) power plants were developed. Two of these configurations are compared in this paper, from the exergetic viewpoint. The exergetic comparison identifies the causes of performance differences between the two cases: differences in the exergy destruction of the gasification system, the gas turbine system, and the gas cooling process, as well as differences in the exergy loss accompanying the solids to disposal stream. The potential for using oxygen-blown versus air-blown KRW gasifiers, and hot gas versus cold gas cleanup processes is evaluated

Thermochemical equilibrium modelling of a gasifying process

International Nuclear Information System (INIS)

Melgar, Andres; Perez, Juan F.; Laget, Hannes; Horillo, Alfonso

2007-01-01

This article discusses a mathematical model for the thermochemical processes in a downdraft biomass gasifier. The model combines the chemical equilibrium and the thermodynamic equilibrium of the global reaction, predicting the final composition of the producer gas as well as its reaction temperature. Once the composition of the producer gas is obtained, a range of parameters can be derived, such as the cold gas efficiency of the gasifier, the amount of dissociated water in the process and the heating value and engine fuel quality of the gas. The model has been validated experimentally. This work includes a parametric study of the influence of the gasifying relative fuel/air ratio and the moisture content of the biomass on the characteristics of the process and the producer gas composition. The model helps to predict the behaviour of different biomass types and is a useful tool for optimizing the design and operation of downdraft biomass gasifiers

Design, development and testing of small downdraft gasifiers for domestic cookstoves

International Nuclear Information System (INIS)

Sutar, Kailasnath B.; Kohli, Sangeeta; Ravi, M.R.

2017-01-01

The design methodology available in the literature for downdraft gasifiers of large capacity (∼40–600 kW_t_h) is not directly applicable to very small sized gasifiers. In the present work, design and development of small downdraft gasifiers of 4 kW_t_h and 2.5 kW_t_h nominal capacities, for domestic cookstove application, have been carried out by non-linear extrapolation of data in literature for large gasifiers. The prototypes thus developed were found to give maximum gasification efficiency close to 80%. Extensive experimentation was conducted in the laboratory to study the effect of two operating parameters, viz., gasification air flow rate and the fuel particle size, on the performance of these gasifiers. The performance parameters studied included calorific value of the gas, gasification efficiency, air-biomass ratio and the hearth load. Through detailed analysis of the results, it has been shown that the two operating parameters affect the gasifier performance primarily through their impact on reactor temperature and the total particle surface area available for the reactions. This explains the observation of an optimal gasification air flow rate for best gasification efficiency. It is also shown that the producer gas flow rate varies linearly with gasification air flow rate for a wide range of operating conditions on different sizes of gasifiers. It is also seen that different sizes of the gasifiers can have a different hearth load corresponding to best efficiency. - Highlights: • Developed a design methodology for small downdraft gasifiers by adapting guidelines meant for larger gasifiers. • Developed two prototypes of gasifiers: 4 kW_t_h and 2.5 kW_t_h with gasification efficiency ∼80%. • Reactor temperature and total particle surface area available for reactions affect the gasifier performance. • The optimal gasification air flow rate and particle size for best gasification efficiency are explained using the above. • Producer gas versus

Improved Gasifier Availability with Bed Material and Additives

Energy Technology Data Exchange (ETDEWEB)

Grootjes, A.J.; Van der Meijden, C.M.; Visser, H.J.M.; Van der Drift, A. [ECN Biomass and Energy Efficiency, Petten (Netherlands)

2013-07-15

In order to valorize several feedstock, gasification is one of the technologies developed over the past decades. ECN developed the MILENA gasifier. In order for MILENA to become a commercial success, the gasifier needs to be feedstock flexible, robust and economically sound, operating with high availability. One of the characteristics of MILENA is high efficiency but with a higher tar content, compared to some other Dual Fluidized Bed (DFB) gasifiers. In order to reduce the issues that are associated with high tar levels in the product gas, the effect of a number of primary measures was studied. This paper presents results obtained in the last two years, focused on improving the gasifier availability by conducting experiments in a 25 kWth lab scale MILENA gasifier. Amongst others, gas composition, tar content and calorific value of the product gas were compared. Scanning Electron Microscope analysis was used to investigate bed material changes. Results show that Austrian olivine can be activated by Fuel B as well as by Additive A and B. The water-gas shift reaction is enhanced and the tar content is reduced significantly, especially the heavy tars that dominate the tar dew point. Activated olivine has a calcium-rich layer. The results show that with MILENA, we are able to lower and control the tar dew point, which will possibly increase the availability of a MILENA gasifier.

Performance evaluation of open core gasifier on multi-fuels

Energy Technology Data Exchange (ETDEWEB)

Bhoi, P.R.; Singh, R.N.; Sharma, A.M.; Patel, S.R. [Thermo Chemical Conversion Division, Sardar Patel Renewable Energy Research Institute (SPRERI), Vallabh Vidyanagar 388 120, Gujarat (India)

2006-06-15

Sardar Patel renewable energy research institute (SPRERI) has designed and developed open core, throat-less, down draft gasifier and installed it at the institute. The gasifier was designed for loose agricultural residues like groundnut shells. The purpose of the study is to evaluate the gasifier on multi-fuels such as babul wood (Prosopis juliflora), groundnut shell briquettes, groundnut shell, mixture of wood (Prosopis juliflora) and groundnut shell in the ratio of 1:1 and cashew nut shell. The gasifier performance was evaluated in terms of fuel consumption rate, calorific value of producer gas and gasification efficiency. Gasification efficiency of babul wood (Prosopis juliflora), groundnut shell briquettes, groundnut shell, mixture of Prosopis juliflora and groundnut shell in the ratio of 1:1 and cashew nut shell were 72%, 66%, 70%, 64%, 70%, respectively. Study revealed that babul wood (Prosopis juliflora), groundnut shell briquettes, groundnut shell, mixture of wood (Prosopis juliflora) and groundnut shell in the ratio of 1:1 and cashew nut shell were satisfactorily gasified in open core down draft gasifier. The study also showed that there was flow problem with groundnut shell. (author)

Efficiency enhancement in IGCC power plants with air-blown gasification and hot gas clean-up

International Nuclear Information System (INIS)

Giuffrida, Antonio; Romano, Matteo C.; Lozza, Giovanni

2013-01-01

Air-blown IGCC systems with hot fuel gas clean-up are investigated. In detail, the gas clean-up station consists of two reactors: in the first, the raw syngas exiting the gasifier and passed through high-temperature syngas coolers is desulfurized by means of a zinc oxide-based sorbent, whereas in the second the sulfided sorbent is duly regenerated. The hot fuel gas clean-up station releases H 2 S-free syngas, which is ready to fuel the combustion turbine after hot gas filtration, and a SO 2 -laden stream, which is successively treated in a wet scrubber. A thermodynamic analysis of two air-blown IGCC systems, the first with cold fuel gas clean-up and the second with hot fuel gas clean-up, both with a state-of-the-art combustion turbine as topping cycle, shows that it is possible to obtain a really attractive net efficiency (more than 51%) for the second system, with significant improvements in comparison with the first system. Nevertheless, higher efficiency is accomplished with a small reduction in the power output and no sensible efficiency improvements seem to be appreciated when the desulfurization temperature increases. Other IGCC systems, with an advanced 1500 °C-class combustion turbine as the result of technology improvements, are investigated as well, with efficiency as high as 53%. - Highlights: ► Hot fuel gas clean-up is a highly favorable technology for IGCC concepts. ► Significant IGCC efficiency improvements are possible with hot fuel gas clean-up. ► Size reductions of several IGCC components are possible. ► Higher desulfurization temperatures do not sensibly affect IGCC efficiency. ► IGCC efficiency as high as 53% is possible with a 1500°C-class combustion turbine

Blown-up orbifolds

International Nuclear Information System (INIS)

Cvetic, M.

1987-05-01

A method to repair - ''blow-up'' - the singularities of the Abelian (2,2) orbifolds to obtain the corresponding (2,2) Calabi-Yau manifolds is presented. This approach makes use of the fact that with each orbifold singularity there are associated massless scalar fields - blowing-up modes - whose potential is flat to all orders in the string perturbation theory. The zero vacuum expectation values (VEV's) of the blowing-up modes correspond to the orbifold limit, while nonzero VEV's yield the corresponding Calabi-Yau manifold. One can then calculate explicitly, for such Calabi-Yau manifolds, the mass spectrum, Yukawa couplings, and all the other parameters of the effective Lagrangian by inserting successively all the background blowing-up modes with nonzero vacuum expectation value into the corresponding orbifold amplitudes. The results are exact at the string tree-level; however, they are perturbative in the blowing-up procedure. Mass spectra and Yukawa couplings for the blown-up Z 3 and Z 4 orbifolds are explicitly calculated. In particular all the E 6 singlets except the ones associated with the moduli-space of the blown-up orbifolds receive the mass; while the 27's and anti 27's do not pair up

SYSTEM ANALYSIS OF NUCLEAR-ASSISTED SYNGAS PRODUCTION FROM COAL

International Nuclear Information System (INIS)

E. A. Harvego; M. G. McKellar; J. E. O'Brien

2008-01-01

A system analysis has been performed to assess the efficiency and carbon utilization of a nuclear-assisted coal gasification process. The nuclear reactor is a high-temperature helium-cooled reactor that is used primarily to provide power for hydrogen production via high-temperature electrolysis. The supplemental hydrogen is mixed with the outlet stream from an oxygen-blown coal gasifier to produce a hydrogen-rich gas mixture, allowing most of the carbon dioxide to be converted into carbon monoxide, with enough excess hydrogen to produce a syngas product stream with a hydrogen/carbon monoxide molar ratio of about 2:1. Oxygen for the gasifier is also provided by the high-temperature electrolysis process. Results of the analysis predict 90.5% carbon utilization with a syngas production efficiency (defined as the ratio of the heating value of the produced syngas to the sum of the heating value of the coal plus the high-temperature reactor heat input) of 66.1% at a gasifier temperature of 1866 K for the high-moisture-content lignite coal considered. Usage of lower moisture coals such as bituminous can yield carbon utilization approaching 100% and 70% syngas production efficiency

System Analysis of Nuclear-Assisted Syngas Production from Coal

International Nuclear Information System (INIS)

Harvego, E.A.; McKellar, M.G.; O'Brien, J.E.

2009-01-01

A system analysis has been performed to assess the efficiency and carbon utilization of a nuclear-assisted coal gasification process. The nuclear reactor is a high-temperature helium-cooled reactor that is used primarily to provide power for hydrogen production via high temperature electrolysis. The supplemental hydrogen is mixed with the outlet stream from an oxygen-blown coal gasifier to produce a hydrogen-rich gas mixture, allowing most of the carbon dioxide to be converted into carbon monoxide, with enough excess hydrogen to produce a syngas product stream with a hydrogen/carbon monoxide molar ratio of about 2:1. Oxygen for the gasifier is also provided by the high-temperature electrolysis process. Results of the analysis predict 90.5% carbon utilization with a syngas production efficiency (defined as the ratio of the heating value of the produced syngas to the sum of the heating value of the coal plus the high-temperature reactor heat input) of 64.4% at a gasifier temperature of 1866 K for the high-moisture-content lignite coal considered. Usage of lower moisture coals such as bituminous can yield carbon utilization approaching 100% and 70% syngas production efficiency.

Fundamental Study of Black Liquor Gasification Kinetics. Quarterly progress report for the period October 1999 to December 1999

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-01-31

The overall objective of this research is to evaluate the kinetics of gasification of kraft black liquor under laboratory conditions simulating pressurized, oxygen-blown gasification. The significant independent variables are gasifier temperature, black liquor composition particle size, and particle residence time. The authors will quantify their impact on the concentration of major and trace gas phase species, as well as the composition of condensed phase inorganic products, including specification of the Na- and S-containing compounds and overall carbon conversion.

Modeling work of a small scale gasifier/SOFC CHP system

Energy Technology Data Exchange (ETDEWEB)

Liu, M.; Aravind, P.V.; Qu, Z.; Woudstra, N.; Verkooijen, A.H.M. [Delft University of Technology (Netherlands). Dept. of Mechanical Engineering], Emails: ming.liu@tudelft.nl, p.v.aravind@tudelft.nl, z.qu@tudelft.nl, n.woudstra@tudelft.nl, a. h. m. verkooijen@tudelft.nl; Cobas, V.R.M. [Federal University of Itajuba (UNIFEI), Pinheirinhos, MG (Brazil). Dept. of Mechanical Engineering], E-mail: vlad@unifei.edu.br

2009-07-01

For a highly efficient biomass gasification/Solid Oxide Fuel Cell (SOFC) Combined Heat and Power (CHP) generation system, the gasifier, the accompanying gas cleaning technologies and the CHP unit must be carefully designed as an integrated unit. This paper describes such a system involving a two-stage fixed-bed down draft gasifier, a SOFC CHP unit and a gas cleaning system. A gas cleaning system with both low temperature and high temperature sections is proposed for coupling the gasifier and the SOFC. Thermodynamic modeling was carried out for the gasifier/SOFC system with the proposed gas cleaning system. The net AC electrical efficiency of this system is around 30% and the overall system efficiency is around 60%. This paper also describes various exergy losses in the system and the future plans for integrated gasifier-GCU-SOFC experiments from which the results will be used to validate the modeling results of this system. (author)

A rice husk gasifier for paddy drying

International Nuclear Information System (INIS)

Mirani, A.A.; Kalwar, S.A.; Ahmad, M.

2013-01-01

Due to energy crisis and constant increase in the price of fossil fuels, the world's trend changes to renewable sources of energy like solar, wind and biomass gasification. Substantial biomass potential is available in Pakistan in the form of agriculture or forest residue (rice straw, rice husk, cotton stalks, corn cobs, wood chips, wood saw, etc.). These can be best utilised for the production of producer gas or synthetic gas that can be used for drying of agricultural crops. The drying process is an important activity of post harvest processing for long-term storage. Rice husk is nowadays commonly used for biomass gasification and its heat content value is about 15MJ/kg. It constitutes about 30 percent of rice production. A rice husk gasifier was developed and evaluated on paddy drying at Japan International Cooperation Agency (JICA), Tsukuba International Center (TBIC), Japan. Rice husk gasifier has following major components; husk feeding system, ash chamber, burner, centrifugal fan, drying chamber, gasifier reactor, air duct and an electric motor of 0.37kW. The average drying plenum air temperature was recorded as 45 degree C during the drying process. The paddy 'IR 28' from initial moisture content of 24% was dried up to 14% moisture content for about 3.33h consuming 3kg/h of rice husk. The efficiency was found to be 58%. The rice husk gasifier can also be used for drying the fruits and vegetables, provided that heat exchanger should be attached with it. The overall performance of rice husk gasifier was satisfactory and will be beneficial for small scale farmers, food processors and millers as well. (author)

Performance and Characteristics of a Cyclone Gasifier for Gasification of Sawdust

Science.gov (United States)

Azman Miskam, Muhamad; Zainal, Z. A.; Idroas, M. Y.

The performance and characteristics of a cyclone gasifier for gasification of sawdust has been studied and evaluated. The system applied a technique to gasify sawdust through the concept of cyclonic motion driven by air injected at atmospheric pressure. This study covers the results obtained for gasification of ground sawdust from local furniture industries with size distribution ranging from 0.25 to 1 mm. It was found that the typical wall temperature for initiating stable gasification process was about 400°C. The heating value of producer gas was about 3.9 MJ m-3 that is sufficient for stable combustion in a dual-fuel engine generator. The highest thermal output from the cyclone gasifier was 57.35 kWT. The highest value of mass conversion efficiency and enthalpy balance were 60 and 98.7%, respectively. The highest efficiency of the cyclone gasifier obtained was 73.4% and this compares well with other researchers. The study has identified the optimum operational condition for gasifying sawdust in a cyclone gasifier and made conclusions as to how the steady gasification process can be achieved.

Development of standardized air-blown coal gasifier/gas turbine concepts for future electric power systems. Volume 3, Appendix B: NO{sub x} and alkali vapor control strategies: Final report

Energy Technology Data Exchange (ETDEWEB)

1990-07-01

CRS Sirrine (CRSS) is evaluating a novel IGCC process in which gases exiting the gasifier are burned in a gas turbine combustion system. The turbine exhaust gas is used to generate additional power in a conventional steam generator. This results in a significant increase in efficiency. However, the IGCC process requires development of novel approaches to control SO{sub 2} and NO{sub x} emissions and alkali vapors which can damage downstream turbine components. Ammonia is produced from the reaction of coal-bound nitrogen with steam in the reducing zone of any fixed bed coal gasifier. This ammonia can be partially oxidized to NO{sub x} when the product gas is oxidized in a gas turbine combustor. Alkali metals vaporize in the high-temperature combustion zone of the gasifier and laser condense on the surface of small char or ash particles or on cooled metal surfaces. It these alkali-coated materials reach the gas turbine combustor, the alkali will revaporize condense on turbine blades and cause rapid high temperature corrosion. Efficiency reduction will result. PSI Technology Company (PSIT) was contracted by CRSS to evaluate and recommend solutions for NO{sub x} emissions and for alkali metals deposition. Various methods for NO{sub x} emission control and the potential process and economic impacts were evaluated. This included estimates of process performance, heat and mass balances around the combustion and heat transfer units and a preliminary economic evaluation. The potential for alkali metal vaporization and condensation at various points in the system was also estimated. Several control processes and evaluated, including an order of magnitude cost for the control process.

Scaling up biomass gasifier use: an application-specific approach

International Nuclear Information System (INIS)

Ghosh, Debyani; Sagar, Ambuj D.; Kishore, V.V.N.

2006-01-01

Biomass energy accounts for about 11% of the global primary energy supply, and it is estimated that about 2 billion people worldwide depend on biomass for their energy needs. Yet, most of the use of biomass is in a primitive and inefficient manner, primarily in developing countries, leading to a host of adverse implications on human health, environment, workplace conditions, and social well being. Therefore, the utilization of biomass in a clean and efficient manner to deliver modern energy services to the world's poor remains an imperative for the development community. One possible approach to do this is through the use of biomass gasifiers. Although significant efforts have been directed towards developing and deploying biomass gasifiers in many countries, scaling up their dissemination remains an elusive goal. Based on an examination of biomass gasifier development, demonstration, and deployment efforts in India-a country with more than two decades of experiences in biomass gasifier development and dissemination, this article identifies a number of barriers that have hindered widespread deployment of biomass gasifier-based energy systems. It also suggests a possible approach for moving forward, which involves a focus on specific application areas that satisfy a set of criteria that are critical to deployment of biomass gasifiers, and then tailoring the scaling up strategy to the characteristics of the user groups for that application. Our technical, financial, economic and institutional analysis suggests an initial focus on four categories of applications-small and medium enterprises, the informal sector, biomass-processing industries, and some rural areas-may be particularly feasible and fruitful

Design and techno economic evaluation of biomass gasifier for ...

African Journals Online (AJOL)

user

2Department of Renewable Energy Sources, College of Technology and Engineering, Maharana Pratap University of. Agriculture ... downdraft gasifier for industrial process heat application. The gasifier is ... generation and biofuels production, and it may be pro- ... Nomenclature: ηg, The hot gas efficiency of the gasification.

Green power production by co-gasification of biomass in coal-fired oxygen-blown entrained-flow based IGCC processes

Energy Technology Data Exchange (ETDEWEB)

Van Ree, R; Korbee, R; De Smidt, R P; Jansen, D [ECN Fuels Conversion and Environment, Petten (Netherlands); Baumann, H R; Ullrich, N [Krupp Uhde, Dortmund (Germany); Haupt, G; Zimmerman, [Siemens, Erlangen (Germany)

1998-11-01

The use of coal for large scale power production meets a growing environmental concern. In spite of the fact that clean coal conversion technologies integrated with high-efficiency power production facilities, such as IGCC, are developed, the aim for sustainable development strives for a power production system based on renewable energy sources. One of the most promising renewable energy sources that can be used in the Netherlands is biomass, i.e. organic waste materials and/or energy crops. To accelerate the introduction of this material, in a technical and economically acceptable way, co-gasification with fossil fuels, in particular coal, in large scale IGCC processes is considered. In this paper the technical feasibility, economic profitability, and environmental acceptability of co-gasification of biomass in coal-fired oxygen-blown entrained-flow based IGM is discussed. Both a base-case coal-fired oxygen-blown entrained-flow based IGCC process - showing strong resemblance to the Puertollano IGCC plant in Spain - and three co-gasification concepts, viz.: (1) a concept with separate dry coal and biomass feeding systems, (2) a concept with a combined dry coal/biomass-derived pyrolysis char feeding system, and (3) a concept with parallel biomass pre-treatment/gasification and combined fuel gas clean-up/power production, were defined for further consideration. The base-case system and the co-gasification concepts as well are modelled in the flowsheet simulation package ASPEN{sup +}. Steady-state integral system calculations resulted in an overall net electrical plant efficiency for the base-case system of 50. 1 %LHV (48.3 %HHV). Replacing about 10 % of the total thermal plant input (coal) by biomass (willow) resulted in a decrease of the overall net electrical plant efficiency of 1.4 to 2.1 %-points LHV, avoided specific CO2 emissions of 40-49 g/kWh{sub e}, and total avoided CO2 emissions of about 129 to 159 kt/a, all depending on the co-gasification concept

Test of pyrolysis gasifier stoves in two institutional kitchens in Uganda

DEFF Research Database (Denmark)

Wendelbo, Pall; Nielsen, Per Sieverts

1998-01-01

: The main purpose of the paper is to evaluate tests of institutional kitchens carried out at schools in Uganda 1997. The results of the tests for the institutional kitchen with pyrolysis gasifier stoves are compared with the fuel use in traditional kitchens with three-stone stoves. The project......, respectively. The cooking place was build up with a rotating plate on which tree gasifier units were placed. In this way it was possible to change on of the gasifier units when necessary. The pot was then mounted on a tripod app. 10 cm above the gasifier units. The results of the tests show that the improved...

Handbook of biomass downdraft gasifier engine systems

Energy Technology Data Exchange (ETDEWEB)

Reed, T B; Das, A

1988-03-01

This handbook has been prepared by the Solar Energy Research Institute under the US Department of Energy /bold Solar Technical Information Program/. It is intended as a guide to the design, testing, operation, and manufacture of small-scale (less than 200 kW (270 hp)) gasifiers. A great deal of the information will be useful for all levels of biomass gasification. The handbook is meant to be a practical guide to gasifier systems, and a minimum amount of space is devoted to questions of more theoretical interest.

On the gasification of biomass in a steam-oxygen blown CFB gasifier with the focus on gas quality upgrading : Technology background, experiments and mathematical modeling

NARCIS (Netherlands)

Siedlecki, M.

2011-01-01

This work presents and discusses the results of the research on the gasification of biomass in an atmospheric circulating fluidized bed, with a mixture of steam and oxygen as fluidization / gasification medium. The main objectives of this research were to investigate and improve the gasification

Exergetic assessment of an integrated gasifier/boiler system for hydrogen production with different biomass types

International Nuclear Information System (INIS)

Kalinci, Y.; Hepbasli, A.; Dincer, I.

2009-01-01

In this study, we utilize some experimental data taken from the literature, especially on the air blown gasification characteristics of six different biomass fuels, namely almond shell (ASF), walnut pruning (WPF), rice straw (RSF), whole tree wood chips (WWF), sludge (SLF) and non-recyclable waste paper (NPF) for hydrogen production from an integrated gasifier-boiler power system. Then, we undertake an exergy analysis of this integrated system and assess its performance through energy and exergy efficiencies. The exergy content values calculated for the biomass fuels range from 15.89 to 22.07 MJ/kg. The stack gas is examined at cyclone out, and the hydrogen concentrations determined change between 7 and 18 (%v/v) for NPF and ASF. Furthermore, the system considered is studied in terms of irreversibility and improvement potential rates. These rate values change from 6.82 to 43.11 kW for irreversibility and 6.01 to 41.24 kW for improvement potential, respectively. The exergy efficiencies of the system are calculated as 4.33 to 11.89%. Finally, we consider N and NH 3 contents of the six biomass fuels and their stack gas compositions. (author)

Numerical Investigation for the Plasma Coal Gasifier of 150kW and 1400kW

Energy Technology Data Exchange (ETDEWEB)

Choi, Hyeong Yeong; Suh, Jae Seung [Hannam University, Daejeon (Korea, Republic of); Lho, Tai Hyeop [National Fusion Research Institute, Daejeon (Korea, Republic of)

2016-05-15

This study has verification of simulation for the gasifier of 150kWe and focuses on prediction of performance for the gasifier of 1.4MWe with a computational fluid dynamics (CFD) method. It is possible to predict flow patterns, tracks of particles, combustion characteristics, temperature distributions and chemical distributions using the commercial CFD solver ANSYS/FLUENT. Integrated coal gasification combined cycle (IGCC) has gained a lot of interest because they can produce cleaner gaseous fuels such as hydrogen, carbon monoxide and methane. Therefore, the National Fusion Research Institute (NFRI) plant has been investigating the application of their plasma technology to gasify coal. It is a fusion plasma technology for better efficiency of low-carbon fuels. They recently completed experiment for the gasifier of 150kwe, and are currently trying experiment for the gasifier of 1.4MWe. They have tried to design the gasifier that has cold gases of a higher efficiency. However it is considerably complicated and expensive that performance of gasifier is experimentally studied, because it is difficult to measure or control gases of very high temperature. This study has numerical investigation for the phenomena of coal gasification for coal gasifier of 150kWe and 1.4MWe at experiment operating conditions. This study has verification of simulation for the gasifier of 150kWe, and predicts performance for the gasifier of 1.4MWe. The gasifier of 1.4MWe will have a cold gas of higher efficiency than gasifier of 150kWe because can generate many hydrogen gas. So this gasification has the potential to become cornerstone technology in many hydrogen industries.

Performance and emission reduction potential of micro-gasifier improved through better design

Directory of Open Access Journals (Sweden)

Kamil Dino Adem

2017-01-01

Full Text Available Biomass gasification is getting popular for household cooking application in most developing countries including Ethiopia. The preference for biomass gasification is due to the generation of less CO (Carbon Monoxide and PM (Particulate Matter in comparison with other biomass cookstoves. Our study showed the improvement in thermal efficiency and emission reduction potential of micro-gasifier. A prototype micro-gasifier was built and tested using the water boiling test protocol. The test results gave a thermal efficiency of 39.6% and a specific fuel consumption of 57 g of fuel/ liter of water. With regard to indoor air pollution, the maximum CO & PM registered were 12.5 ppm and 1.85 mg/m3, respectively. Using clean development mechanism (CDM methodology, the estimated emission reduction potential of the micro-gasifier is 1.30 tCO2 per micro-gasifier per year. Generally, the micro-gasifier has better performance compared to the previous designs proposed by other researchers. Thus, disseminating our micro-gasifier at a larger scale in developing countries such as Ethiopia will be beneficial in reducing deforestation and emission that will be brought about by using open-fire stoves and thus, helps to obtain carbon credit.

Slagging gasifier refractories. A new pathway to longer refractory life

Energy Technology Data Exchange (ETDEWEB)

Schnake, Mark [Harbinson-Walker Refractories Company, Mexico, MO (United States)

2013-07-01

Solid fuel slagging gasification to convert coal or petroleum coke feedstocks into syngas has rapidly evolved over the last 25 years. The gasifier is a high temperature, high pressure reaction chamber. Operating temperatures are between 1250 and 1575 C. Pressures will be between 20.4 and 68 atm. Syngas has been typically used for chemical feedstocks, fuel for power plants, or for steam and hydrogen generation in other industrial applications. Ash which comes from the solid fuel during gasification has many impurities. It melts during the gasifier reactor operation forming a liquid that penetrates the refractory lining. Given time, the refractory will wear away from thermal spalling, structural spalling, or overheating of the refractory. In some cases, all three wear mechanisms are seen in the same gasifier lining. Industry users have identified refractory life as one major limiting factor in worldwide use of this technology. Users have stated if the refractory liner can increase on-line availability of the gasifier operation, more industry acceptance of this technology is possible. Harbison-Walker Refractories Company will review destructive factors affecting lining life and discuss new refractory materials that have dramatically increased gasifier lining life and reliability. New refractory materials will be presented and supported by field trial results and post mortem analysis.

Gasification of ‘Loose' Groundnut Shells in a Throathless Downdraft Gasifier

OpenAIRE

Kuhe, Aondoyila; Aliyu, Samuel Jacob

2015-01-01

In this paper, gasification potential of biomass residue was investigated using a laboratory scale throatless downdraft gasifier. Experimental results of groundnut shell was gasified in the throatless downdraft gasifier to produce a clean gas with a calorific value of around 5.92 MJ/Nm3 and a combustible fraction of 45% v/v. Low moisture (8.6%) and ash content (3.19%) are the main advantages of groundnut shells for gasification. It is suggested that gasification of shell waste products is a ...

FY 1996 report on the results of the development of an entrained bed coal gasification power plant. Part 2. Investigational study of verification plant; 1995 nendo seika hokokusho. Funryusho sekitan gaska hatsuden plant kaihatsu - Sono 2. Jissho plant ni kansuru chosa kenkyu hen

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-01-01

For the purpose of developing the technology of the integrated coal gasification combined cycle power generation, an investigational study of verification plant was made, and the FY 1996 results were summarized. In this fiscal year, the conceptual design was made of the Nakoso method based on the method of Nakoso pilot plant, the fixed bed method in which fixed bed gas refining facilities tested in Nakoso pilot plant were adopted, and the packed bed method. In the Nakoso method, 5 cases were studied using the air blown two-stage entrained bed for gasifier, dry two-stage fluidized bed for desulfurization and dry granular bed packed bed for dust removal. In the fixed bed method, 2 cases were studied using the air blown two-stage entrained bed for gasifier and dry fixed bed for gas refining. In the packed bed method, 2 cases were studied using the air blown two-stage entrained bed for gasifier and dry packed bed for gas refining. As to gas turbine facilities, 5 cases were studied in which GT output is 115MW - 215MW (output of combined cycle power generation: 220MW - 420MW). (NEDO)

A moving-bed gasifier with internal recycle of pyrolysis gas

NARCIS (Netherlands)

Susanto, H.; Beenackers, A.A C M

A co-current moving bed gasifier with internal recycle and separate combustion of pyrolysis gas has been developed with the aim of producing a design suitable for scaling-up downdraft gasifiers while maintaining a low tar content in the producer gas. Using wood chips with a moisture content of 7-9

Effects of upgrading systems on energy conversion efficiency of a gasifier - fuel cell - gas turbine power plant

International Nuclear Information System (INIS)

Pedrazzi, Simone; Allesina, Giulio; Tartarini, Paolo

2016-01-01

Highlights: • An advanced gasifier-SOFC-MGT system is modeled. • An overall electrical efficiency of 32.81% is reached. • Influence of all the sub-system modeled on the power plant efficiency is discussed. • Compression storage of syngas is taken into account. - Abstract: This work focuses on a DG-SOFC-MGT (downdraft gasifier - solid oxide fuel cell - micro gas turbine) power plant for electrical energy production and investigates two possible performance-upgrading systems: polyphenylene oxide (PPO) membrane and zeolite filters. The first is used to produce oxygen-enriched air used in the reactor, while the latter separates the CO_2 content from the syngas. In order to prevent power plant shutdowns during the gasifier reactor scheduled maintenance, the system is equipped with a gas storage tank. The generation unit consists of a SOFC-MGT system characterized by higher electrical efficiency when compared to conventional power production technology (IC engines, ORC and EFGT). Poplar wood chips with 10% of total moisture are used as feedstock. Four different combinations with and without PPO and zeolite filtrations are simulated and discussed. One-year energy and power simulation were used as basis for comparison between all the cases analyzed. The modeling of the gasification reactions gives results consistent with literature about oxygen-enriched processes. Results showed that the highest electrical efficiency obtained is 32.81%. This value is reached by the power plant equipped only with PPO membrane filtration. Contrary to the PPO filtering, zeolite filtration does not increase the SOFC-MGT unit performance while it affects the energy balance with high auxiliary electrical consumption. This solution can be considered valuable only for future work coupling a CO_2 sequestration system to the power plant.

Numerical Model of Dephosphorization Reaction Kinetics in Top Blown Converter Coupled with Flow Field

Science.gov (United States)

Liu, Wei; Yang, Shufeng; Li, Jingshe; Wang, Minghui

2017-07-01

A 3D transient numerical model of dephosphorization kinetics coupled with flow field in a top blown converter was built. Through the model the dephosphorization reaction rate influenced by the oxygen jets and the steel flow were simulated. The results show that the dephosphorization rate at the droplet metal-slag interface is two orders of magnitude faster than that at bath metal-slag interface. When the lance oxygen pressure increases from 0.7 to 0.8 MPa, the dephosphorization rate increases notably and the end content of P has a decrease of 19 %. However, when the pressure continues rising to 0.9 MPa, the dephosphorization rate has no significant increase. In addition, the lance height shows a nearly linear relation to the end P content of steel, that the lower the height, the faster the dephosphorization rate.

Method for online measurement of the CHON composition of raw gas from biomass gasifier

International Nuclear Information System (INIS)

Neves, Daniel; Thunman, Henrik; Tarelho, Luís; Larsson, Anton; Seemann, Martin; Matos, Arlindo

2014-01-01

Highlights: • Measuring the CHON composition of a raw gas by current methods is challenging. • An alternative method is to burn the raw gas before measuring the CHON composition. • The CHON contents of the raw gas can be accurately measured by the alternative method. • Measuring the CHON contents of the raw gas is now performed in a “one-step” analysis. • The new method is used to evaluate the operation of a dual fluidised bed gasifier. - Abstract: For unattended biomass gasification processes, rapid methods for monitoring the elemental composition (CHON) of the raw gas leaving the gasifier are needed. Conventional methods rely on time-consuming and costly laboratory procedures for analysing the condensable part of the raw gas. An alternative method, presented in this work, assesses the CHON composition of raw gas in a “one step” analysis without the need to previously characterise its chemical species composition. Our method is based on the quantitative conversion of a raw gas of complex chemical composition into CO 2 , H 2 O, and N 2 in a small combustor. The levels of these simple species can be measured with high accuracy and good time resolution, and the CHON composition of the raw gas can be determined from the mass balance across the combustor. To evaluate this method, an online combustion facility was built and used to analyse the raw gas from the Chalmers 2-MW th dual fluidised bed steam gasifier. Test runs of the developed facility demonstrated complete combustion of the raw gas and the measurements were both fast and reliable. The new method used in combination with zero-dimensional reactor modelling provides valuable data for the operational monitoring of gasification processes, such as the degree of fuel conversion, composition of the char exiting the gasifier, oxygen transport by catalytic bed material, and amount of condensables in raw gas

Artificial neural network models for biomass gasification in fluidized bed gasifiers

DEFF Research Database (Denmark)

Puig Arnavat, Maria; Hernández, J. Alfredo; Bruno, Joan Carles

2013-01-01

Artificial neural networks (ANNs) have been applied for modeling biomass gasification process in fluidized bed reactors. Two architectures of ANNs models are presented; one for circulating fluidized bed gasifiers (CFB) and the other for bubbling fluidized bed gasifiers (BFB). Both models determine...

Emission characterization for a down draft gasifier

Energy Technology Data Exchange (ETDEWEB)

Alves, Charles Denys da Luz; Nogueira, Manoel Fernandes Martins [Federal University of Para (UFPA), Belem, PA (Brazil). Lab. de Engenharia Mecanica], E-mail: mfmn@ufpa.br

2010-07-01

Gasification is the thermal-chemical conversion of biomass into combustible gas, which can be used as combustion fuel in internal combustion motors or syngas with applications across the chemical industry. To check the performance of a gasifier one needs to quantify the contained energy in the produced gas as well as the quantity of produced carbon for the calculation of mean energy efficiency and the carbon conversion factor of the gas using experimentally obtained data. Energy efficiency is quantified value that describes the relationship between the respective quantities of energy contained in the biomass used and the gas produced, in the same sense, the carbon conversion is a quantity of carbonaceous compounds present in used biomass and the amount of carbon in the produced gas. The present document evaluates the energy efficiency and the carbon conversion factor of a prototype model of a downdraft gasifier from India that was modified by a local company. The nominal parameters of the gasifier's function are as follows: gas production capacity running on 45 kW, biomass consumption (acai seeds) of 15 kg/h. The gasifier dimensions are as follows: diameter of 150 mm and height of 2000 mm. The energy efficiency and the carbon conversion rate are quantified, the pressure loss due to the bed reactor and the temperature of the gases are also measured at the reactor exit; the tar, particle composite and non-condensable gas (CO, CO{sub 2}, CH{sub 4}, SO{sub 2}, N{sub 2} e NO{sub x}) concentrations were measured in the produced gas at the cleaning process. (author)

The physics of wind-blown sand and dust.

Science.gov (United States)

Kok, Jasper F; Parteli, Eric J R; Michaels, Timothy I; Karam, Diana Bou

2012-10-01

The transport of sand and dust by wind is a potent erosional force, creates sand dunes and ripples, and loads the atmosphere with suspended dust aerosols. This paper presents an extensive review of the physics of wind-blown sand and dust on Earth and Mars. Specifically, we review the physics of aeolian saltation, the formation and development of sand dunes and ripples, the physics of dust aerosol emission, the weather phenomena that trigger dust storms, and the lifting of dust by dust devils and other small-scale vortices. We also discuss the physics of wind-blown sand and dune formation on Venus and Titan.

Analysis of wind-blown sand movement over transverse dunes.

Science.gov (United States)

Jiang, Hong; Huang, Ning; Zhu, Yuanjian

2014-12-01

Wind-blown sand movement often occurs in a very complicated desert environment where sand dunes and ripples are the basic forms. However, most current studies on the theoretic and numerical models of wind-blown sand movement only consider ideal conditions such as steady wind velocity, flat sand surface, etc. In fact, the windward slope gradient plays a great role in the lift-off and sand particle saltation. In this paper, we propose a numerical model for the coupling effect between wind flow and saltating sand particles to simulate wind-blown sand movement over the slope surface and use the SIMPLE algorithm to calculate wind flow and simulate sands transport by tracking sand particle trajectories. We furthermore compare the result of numerical simulation with wind tunnel experiments. These results prove that sand particles have obvious effect on wind flow, especially that over the leeward slope. This study is a preliminary study on windblown sand movement in a complex terrain, and is of significance in the control of dust storms and land desertification.

Gasification of ‘Loose’ Groundnut Shells in a Throathless Downdraft Gasifier

Directory of Open Access Journals (Sweden)

Aondoyila Kuhe

2015-07-01

Full Text Available In this paper, gasification potential of biomass residue was investigated using a laboratory scale throatless downdraft gasifier. Experimental results of groundnut shell was gasified in the throatless downdraft gasifier to produce a clean gas with a calorific value of around 5.92 MJ/Nm3 and a combustible fraction of 45% v/v. Low moisture (8.6% and ash content (3.19% are the main advantages of groundnut shells for gasification. It is suggested that gasification of shell waste products is a clean energy alternative to fossil fuels. The product gas can be used efficiently for heating and possible usage in internal combustion engines.

A Philippines gasifier case study

International Nuclear Information System (INIS)

Bernardo, F.P.; Kilayko, G.U.

1991-01-01

The gasifier programme failed to achieve its objective of significantly reducing farmers' dependence on diesel fuel and in improving their financial positions both on Panay Island and elsewhere in the Philippines. The causes appear to be institutional and managerial rather than any inherent weakness in the technology itself. 2 tabs

Second stage gasifier in staged gasification and integrated process

Science.gov (United States)

Liu, Guohai; Vimalchand, Pannalal; Peng, Wan Wang

2015-10-06

A second stage gasification unit in a staged gasification integrated process flow scheme and operating methods are disclosed to gasify a wide range of low reactivity fuels. The inclusion of second stage gasification unit operating at high temperatures closer to ash fusion temperatures in the bed provides sufficient flexibility in unit configurations, operating conditions and methods to achieve an overall carbon conversion of over 95% for low reactivity materials such as bituminous and anthracite coals, petroleum residues and coke. The second stage gasification unit includes a stationary fluidized bed gasifier operating with a sufficiently turbulent bed of predefined inert bed material with lean char carbon content. The second stage gasifier fluidized bed is operated at relatively high temperatures up to 1400.degree. C. Steam and oxidant mixture can be injected to further increase the freeboard region operating temperature in the range of approximately from 50 to 100.degree. C. above the bed temperature.

Catalytic Combustion of Gasified Waste

Energy Technology Data Exchange (ETDEWEB)

Kusar, Henrik

2003-09-01

This thesis concerns catalytic combustion for gas turbine application using a low heating-value (LHV) gas, derived from gasified waste. The main research in catalytic combustion focuses on methane as fuel, but an increasing interest is directed towards catalytic combustion of LHV fuels. This thesis shows that it is possible to catalytically combust a LHV gas and to oxidize fuel-bound nitrogen (NH{sub 3}) directly into N{sub 2} without forming NO{sub x} The first part of the thesis gives a background to the system. It defines waste, shortly describes gasification and more thoroughly catalytic combustion. The second part of the present thesis, paper I, concerns the development and testing of potential catalysts for catalytic combustion of LHV gases. The objective of this work was to investigate the possibility to use a stable metal oxide instead of noble metals as ignition catalyst and at the same time reduce the formation of NO{sub x} In paper II pilot-scale tests were carried out to prove the potential of catalytic combustion using real gasified waste and to compare with the results obtained in laboratory scale using a synthetic gas simulating gasified waste. In paper III, selective catalytic oxidation for decreasing the NO{sub x} formation from fuel-bound nitrogen was examined using two different approaches: fuel-lean and fuel-rich conditions. Finally, the last part of the thesis deals with deactivation of catalysts. The various deactivation processes which may affect high-temperature catalytic combustion are reviewed in paper IV. In paper V the poisoning effect of low amounts of sulfur was studied; various metal oxides as well as supported palladium and platinum catalysts were used as catalysts for combustion of a synthetic gas. In conclusion, with the results obtained in this thesis it would be possible to compose a working catalytic system for gas turbine application using a LHV gas.

Energetic, ecologic and fluid-dynamic analysis of a fluidized bed gasifier operating with sugar cane bagasse

International Nuclear Information System (INIS)

Diniz Filho, Paulo Tasso; Silveira, Jose Luz; Tuna, Celso Eduardo; Lamas, Wendell de Queiroz

2013-01-01

This work aims to study the thermodynamic, ecological and fluid-dynamic aspects of a circulating fluidized bed gasifier using sugar cane bagasse as biomass, in order to estimate a model of its normal operation. In the initial stage was analysed the composition of biomass selected (sugar cane bagasse) and its lower heating value (LHV) was calculated. The energy balance of the gasifier was done, being the volumetric flow of air, synthesis gas and biomass estimated. Also the power produced by this gasifier was theoretically estimated. Then the circulating fluidized bed gasifier was designed for operation with approximately 100 kg/h of processed biomass. Cross-sectional area of the reactor, feeder size, diameter of the exit zone of the gases and minimum height of the expanded bed were selected. Some bed gasifier hydrodynamic factors were also studied. The minimum fluidization velocity, fluidization terminal velocity, and average fluidizing velocity were calculated, in order to understand the fluid-dynamic behaviour of gasification of this fuel. It was obtained a theoretical model that can support a possible prototype of circulating fluidized bed gasifier biomass. Finally, there were studied the ecological aspects of the gasifier, through an overall methodology. Ecological efficiencies were estimated for two scenarios: first considering the carbon cycle and thereafter disregarding the carbon cycle. In both cases, it can be proved the ecological viability of the project. -- Highlights: • we develop a methodology to size a fluidized bed gasifier. • we validate this methodology comparing to a fixed bed gasifier values. • we aggregate ecological efficiency to this methodology

A conceptual design of catalytic gasification fuel cell hybrid power plant with oxygen transfer membrane

Science.gov (United States)

Shi, Wangying; Han, Minfang

2017-09-01

A hybrid power generation system integrating catalytic gasification, solid oxide fuel cell (SOFC), oxygen transfer membrane (OTM) and gas turbine (GT) is established and system energy analysis is performed. In this work, the catalytic gasifier uses steam, recycled anode off-gas and pure oxygen from OTM system to gasify coal, and heated by hot cathode off-gas at the same time. A zero-dimension SOFC model is applied and verified by fitting experimental data. Thermodynamic analysis is performed to investigate the integrated system performance, and system sensitivities on anode off-gas back flow ratio, SOFC fuel utilization, temperature and pressure are discussed. Main conclusions are as follows: (1) System overall electricity efficiency reaches 60.7%(HHV) while the gasifier operates at 700 °C and SOFC at 850 °C with system pressure at 3.04 bar; (2) oxygen enriched combustion simplify the carbon-dioxide capture process, which derives CO2 of 99.2% purity, but results in a penalty of 6.7% on system electricity efficiency; (3) with SOFC fuel utilization or temperature increasing, the power output of SOFC increases while GT power output decreases, and increasing system pressure can improve both the performance of SOFC and GT.

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.

Modelling of a downdraft gasifier fed by agricultural residues

International Nuclear Information System (INIS)

Antonopoulos, I.-S.; Karagiannidis, A.; Gkouletsos, A.; Perkoulidis, G.

2012-01-01

Highlights: ► Development of software for downdraft gasification simulation. ► Prediction of the syngas concentration. ► Prediction of the syngas heating value. ► Investigation of the temperature effect in reduction zone in syngas concentration. - Abstract: A non-stoichiometric model for a downdraft gasifier was developed in order to simulate the overall gasification process. Mass and energy balances of the gasifier were calculated and the composition of produced syngas was predicted. The capacity of the modeled gasifier was assumed to be 0.5 MW, with an Equivalence Ratio (EQ) of 0.45. The model incorporates the chemical reactions and species involved, while it starts by selecting all species containing C, H, and O, or any other dominant elements. Olive wood, miscanthus and cardoon were tested in the formulated model for a temperature range of 800–1200 °C, in order to examine the syngas composition and the moisture impact on the supplied fuel. Model results were then used in order to design an olive wood gasification reactor.

An update on field test results for an engineered refractory for slagging gasifiers

Energy Technology Data Exchange (ETDEWEB)

Dogan, O.N.; Alman, D.E.; Jablonski, P.D.; Hawk, J.A.

2006-05-01

The widespread commercial adaptation of slagging gasifier technology to produce power, fuel, and/or chemicals from coal will depend in large measure on the technology’s ability to prove itself both economic and reliable. Improvements in gasifier reliability, availability, and maintainability will in part depend on the development of improved performance structural materials with longer service life in this application. Current generation refractory materials used to line the air-cooled, slagging gasifier vessel, and contain the gasification reaction, often last no more than three to 18 months in commercial applications. The downtime required for tear-out and replacement of these critical materials contributes to gasifier on-line availabilities that fall short of targeted goals. In this talk we will discuss the development of an improved refractory material engineered by the NETL for longer service life in this application, and provide an update on recent field test results.

High Performance Gasification with the Two-Stage Gasifier

DEFF Research Database (Denmark)

Gøbel, Benny; Hindsgaul, Claus; Henriksen, Ulrik Birk

2002-01-01

, air preheating and pyrolysis, hereby very high energy efficiencies can be achieved. Encouraging results are obtained at a 100 kWth laboratory facility. The tar content in the raw gas is measured to be below 25 mg/Nm3 and around 5 mg/Nm3 after gas cleaning with traditional baghouse filter. Furthermore...... a cold gas efficiency exceeding 90% is obtained. In the original design of the two-stage gasification process, the pyrolysis unit consists of a screw conveyor with external heating, and the char unit is a fixed bed gasifier. This design is well proven during more than 1000 hours of testing with various...... fuels, and is a suitable design for medium size gasifiers....

Simulation of the biomass updraft gasifier

Energy Technology Data Exchange (ETDEWEB)

Teislev, B.

2006-07-15

A consistent (steady state, one-dimensional) mathematical model for a biomass updraft gasifier has been developed based on mass- and energy balances and assuming ideal mixtures of gases and solids. The gases considered are 0{sub 2}, N{sub 2}, H{sub 2}O, CO{sub 2}, H{sub 2}, CO, CH{sub 4} and TAR and the solids are Ash, Carbon, dry Wood and HzO moisture and described by their partial densities in the gasifier bed, together with their axial velocities and temperature. The processes considered are Carbon Oxidation, H{sub 2}0 and CO{sub 2} reduction, the Water Gas Shift process, dry Wood Pyrolysis and Moist Biomass Drying and are described by their temperature and concentration dependant reaction rates. The same mathematical formulation is used throughout the reactor and the methodology used is to solve the resulting 16 partial and algebraic equations (with 16 variables, 8 gaseous partial densities, 4 solids partial densities, 2 velocities and 2 temperatures) in a Newton-Raphson approach using variable length of the integration step. The transition through oxidation and reduction and the passage through the drying zone has been preliminary verified to be in accordance with experimental evidence, but the software developed has not yet been able to describe the transition to pyrolysis and drying and therefore, the final product gas composition from the updraft gasifier has not been verified (apart from verification using a zero-dimensional model). For use in further work an Addendum describing the approach in the form of a 'pseudo code' (including several comments for readers not conversant with the programming language used in the present work - Visual Basic) is included. (au)

Development of standardized air-blown coal gasifier/gas turbine concepts for future electric power systems. Volume 5, Appendix D: Cost support information: Final report

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.

Lignite chemical conversion in an indirect heat rotary kiln gasifier

Directory of Open Access Journals (Sweden)

Hatzilyberis Kostas S.

2006-01-01

Full Text Available The results on the gasification of Greek lignite using two indirect heat (allothermal pilot rotary kiln gasifiers are reported in the present work. The development of this new reactor-gasifier concept intended for solid fuels chemical conversion exploits data and experience gained from the following two pilot plants. The first unit A (about 100 kg/h raw lignite demonstrated the production of a medium heating value gas (12-13 MJ/Nm3 with quite high DAF (dry ash free coal conversions, in an indirect heat rotary gasifier under mild temperature and pressure conditions. The second unit B is a small pilot size unit (about 10 kg/h raw lignite comprises an electrically heated rotary kiln, is an operation flexible and exhibits effective phase mixing and enhanced heat transfer characteristics. Greek lignite pyrolysis and gasification data were produced from experiments performed with pilot plant B and the results are compared with those of a theoretical model. The model assumes a scheme of three consecutive-partly parallel processes (i. e. drying, pyrolysis, and gasification and predicts DAF lignite conversion and gas composition in relatively good agreement with the pertinent experimental data typical of the rotary kiln gasifier performance. Pilot plant B is currently being employed in lime-enhanced gasification studies aiming at the production of hydrogen enriched synthesis gas. Presented herein are two typical gas compositions obtain from lignite gasification runs in the presence or not of lime. .

Simulation of the biomass updraft gasifier

Energy Technology Data Exchange (ETDEWEB)

Teislev, B.

2006-07-15

A consistent (steady state, one-dimensional) mathematical model for a biomass updraft gasifier has been developed based on mass- and energy balances and assuming ideal mixtures of gases and solids. The gases considered are 0{sub 2}, N{sub 2}, H{sub 2}0, CO{sub 2}, H{sub 2}, CO, CH{sub 4} and TAR and the solids are Ash, Carbon, dry Wood and H{sub 2}O moisture and described by their partial densities in the gasifier bed - together with their axial velocities and temperature. The processes considered are Carbon Oxidation, H{sub 2}0 and CO{sub 2} reduction, the Water Gas Shift process, dry Wood Pyrolysis and Moist Biomass Drying and are described by their temperature and concentration dependant reaction rates. The same mathematical formulation is used throughout the reactor and the methodology used is to solve the resulting 16 partial and algebraic equations (with 16 variables - 8 gaseous partial densities, 4 solids partial densities, 2 velocities and 2 temperatures) in a Newton-Raphson approach using variable length of the integration step. The transition through oxidation and reduction and the passage through the drying zone has been preliminary verified to be in accordance with experimental evidence, but the software developed has not yet been able to describe the transition to pyrolysis and drying and therefore, the final product gas composition from the updraft gasifier has not been verified (apart from verification using a zero-dimensional model). For use in further work an Addendum describing the approach in the form of a 'pseudo code' (including several comments for readers not conversant with the programming language used in the present work - Visual Basic) is included. (au)

Possibility study of gasifier with axial circulating flue gas for reducing Tar

Science.gov (United States)

Poowadin, T.; Polsongkram, M.; Khantikomol, P.

2018-01-01

This present research article aims to study the possibility of gasification by axial core flue gas circulating kiln and find the efficiency of syngas production. An axial core flue gas circulating tube was installed in the center of the updraft gasifier in purposing of tar reducing. In the present study, the eucalyptus wood chip 4, 8, and 10 kg with the moisture content 16% were examined. Several type-K thermocouples were employed to measure the temperatures at preheat, combustion, reduction, pyrolysis, drying, and gas outlet zone. The results showed that the temperatures in the combustion and the reduction zone of the kiln with the axial core flue gas recirculating were lower than the kiln without the core owing to installing the core would reduce the combustion zone area in biomass burning. Obviously, the temperature in the pyrolysis and drying zone were nearly the same as both with and without the core. In consideration of syngas components, it was found that CO production from the gasifier with the core was higher than the gasifier without the core about 25%. Other gases, however, were almost same. The syngas production efficiency obtained from the gasifier with the core decreased with increasing the mass of biomass. It showed that the highest efficiency was 30% at 4 kg supplying biomass. In comparison, the efficiencies of both the kilns with and without the core were not different. For liquid product, the amount of liquid decreased about 47.23% comparing with the gasifier without the core.

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

Science.gov (United States)

Grindley, T.

1988-04-05

A process and apparatus for providing additional desulfurization of the hot gas produced in a fluid-bed coal gasifier, within the gasifier is described. 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 to 1800 F and are partially quenched with water to 1000 to 1200 F before entering the iron oxide bed. The iron oxide bed provides additional desulfurization beyond that provided by the lime /limestone. 1 fig.

Power Systems Development Facility Gasification Test Run TC07

Energy Technology Data Exchange (ETDEWEB)

Southern Company Services

2002-04-05

This report discusses Test Campaign TC07 of the Kellogg Brown & Root, Inc. (KBR) Transport Reactor train with a Siemens Westinghouse Power Corporation (Siemens Westinghouse) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The Transport Reactor is an advanced circulating fluidized-bed reactor designed to operate as either a combustor or a gasifier using a particulate control device (PCD). The Transport Reactor was operated as a pressurized gasifier during TC07. Prior to TC07, the Transport Reactor was modified to allow operations as an oxygen-blown gasifier. Test Run TC07 was started on December 11, 2001, and the sand circulation tests (TC07A) were completed on December 14, 2001. The coal-feed tests (TC07B-D) were started on January 17, 2002 and completed on April 5, 2002. Due to operational difficulties with the reactor, the unit was taken offline several times. The reactor temperature was varied between 1,700 and 1,780 F at pressures from 200 to 240 psig. In TC07, 679 hours of solid circulation and 442 hours of coal feed, 398 hours with PRB coal and 44 hours with coal from the Calumet mine, and 33 hours of coke breeze feed were attained. Reactor operations were problematic due to instrumentation problems in the LMZ resulting in much higher than desired operating temperatures in the reactor. Both reactor and PCD operations were stable and the modifications to the lower part of the gasifier performed well while testing the gasifier with PRB coal feed.

Prediction of the working parameters of a wood waste gasifier through an equilibrium model

Energy Technology Data Exchange (ETDEWEB)

Altafini, Carlos R.; Baretto, Ronaldo M. [Caxias do Sul Univ., Dept. of Mechanical Engineering, Caxias do Sul, RS (Brazil); Wander, Paulo R. [Caxias do Sul Univ., Dept. of Mechanical Engineering, Caxias do Sul, RS (Brazil); Federal Univ. of Rio Grande do Sul State (UFRGS), Mechanical Engineering Postgraduation Program (PROMEC), RS (Brazil)

2003-10-01

This paper deals with the computational simulation of a wood waste (sawdust) gasifier using an equilibrium model based on minimization of the Gibbs free energy. The gasifier has been tested with Pinus Elliotis sawdust, an exotic specie largely cultivated in the South of Brazil. The biomass used in the tests presented a moisture of nearly 10% (wt% on wet basis), and the average composition results of the gas produced (without tar) are compared with the equilibrium models used. Sensitivity studies to verify the influence of the moisture sawdust content on the fuel gas composition and on its heating value were made. More complex models to reproduce with better accuracy the gasifier studied were elaborated. Although the equilibrium models do not represent the reactions that occur at relatively high temperatures ( {approx_equal} 800 deg C) very well, these models can be useful to show some tendencies on the working parameter variations of a gasifier. (Author)

Thermodynamic Model for Updraft Gasifier with External Recirculation of Pyrolysis Gas

Directory of Open Access Journals (Sweden)

Fajri Vidian

2016-01-01

Full Text Available Most of the thermodynamic modeling of gasification for updraft gasifier uses one process of decomposition (decomposition of fuel. In the present study, a thermodynamic model which uses two processes of decomposition (decomposition of fuel and char is used. The model is implemented in modification of updraft gasifier with external recirculation of pyrolysis gas to the combustion zone and the gas flowing out from the side stream (reduction zone in the updraft gasifier. The goal of the model obtains the influences of amount of recirculation pyrolysis gas fraction to combustion zone on combustible gas and tar. The significant results of modification updraft are that the increases amount of recirculation of pyrolysis gas will increase the composition of H2 and reduce the composition of tar; then the composition of CO and CH4 is dependent on equivalence ratio. The results of the model for combustible gas composition are compared with previous study.

Biomass Power Generation through Direct Integration of Updraft Gasifier and Stirling Engine Combustion System

Directory of Open Access Journals (Sweden)

Jai-Houng Leu

2010-01-01

Full Text Available Biomass is the largest renewable energy source in the world. Its importance grows gradually in the future energy market. Since most biomass sources are low in energy density and are widespread in space, small-scale biomass conversion system is therefore more competitive than a large stand-alone conversion plant. The current study proposes a small-scale solid biomass power system to explore the viability of direct coupling of an updraft fixed bed gasifier with a Stirling engine. The modified updraft fixed bed gasifier employs an embedded combustor inside the gasifier to fully combust the synthetic gas generated by the gasifier. The flue gas produced by the synthetic gas combustion inside the combustion tube is piped directly to the heater head of the Stirling engine. The engine will then extract and convert the heat contained in the flue gas into electricity automatically. Output depends on heat input. And, the heat input is proportional to the flow rate and temperature of the flue gas. The preliminary study of the proposed direct coupling of an updraft gasifier with a 25 kW Stirling engine demonstrates that full power output could be produced by the current system. It could be found from the current investigation that no auxiliary fuel is required to operate the current system smoothly. The proposed technology and units could be considered as a viable solid biomass power system.

Simulation of the gasification of animal wastes in a dual gasifier using Aspen Plus®

International Nuclear Information System (INIS)

Fernandez-Lopez, M.; Pedroche, J.; Valverde, J.L.; Sanchez-Silva, L.

2017-01-01

Highlights: • The gasification of manure was evaluated using the software Aspen Plus®. • Composition and LHV of the obtained syngas depends on the operating conditions. • CO 2 net emissions for the steam and CO 2 gasification processes were calculated. • Manure steam gasification can be used as feedstock for Fischer-Tropsch. • Manure CO 2 gasification lead to a syngas suitable for energy production. - Abstract: The gasification of an animal waste biomass (manure) in a dual gasifier was studied using the software Aspen Plus®. For this purpose, a model based on a Gibbs free energy reactor was considered. Effects of the gasification temperature, the gasifying/biomass ratio and the use of steam and CO 2 as the gasifying agents on the composition and the low heating value (LHV) of the produced syngas were evaluated. In this sense, the H 2 /CO ratio and the LHV were the parameters calculated to stablish the best operating conditions for the production of either hydrocarbons via Fischer-Tropsch or energy. Furthermore, the CO 2 net emissions generated by the gasification process were also important in the selection of the best operating conditions from an environmental point of view. The obtained results showed that for both gasifying agents the H 2 and CO production was favoured at high temperatures whereas the production of CH 4 and CO 2 was favoured at low ones. On the other hand, the H 2 production was higher when steam was used as the gasifying agent and the formation of CO was enhanced when CO 2 was considered as gasification agent. An increase of the gasifying agent/biomass ratio had a negatively influence on the production of CH 4 , leading to a decrease of the LHV. Therefore, steam as the gasifying agent and high temperatures favoured the obtaining of a syngas suitable for the Fischer-Tropsch process whereas CO 2 and low gasification temperatures enhanced a syngas with a high LHV which could be used for energy production. Finally, the net CO 2

Gasification of rice straw in a fluidized-bed gasifier for syngas application in close-coupled boiler-gasifier systems.

Science.gov (United States)

Calvo, L F; Gil, M V; Otero, M; Morán, A; García, A I

2012-04-01

The feasibility and operation performance of the gasification of rice straw in an atmospheric fluidized-bed gasifier was studied. The gasification was carried out between 700 and 850 °C. The stoichiometric air-fuel ratio (A/F) for rice straw was 4.28 and air supplied was 7-25% of that necessary for stoichiometric combustion. Mass and power balances, tar concentration, produced gas composition, gas phase ammonia, chloride and potassium concentrations, agglomeration tendencies and gas efficiencies were assessed. Agglomeration was avoided by replacing the normal alumina-silicate bed by a mixture of alumina-silicate sand and MgO. It was shown that it is possible to produce high quality syngas from the gasification of rice straw. Under the experimental conditions used, the higher heating value (HHV) of the produced gas reached 5.1 MJ Nm(-3), the hot gas efficiency 61% and the cold gas efficiency 52%. The obtained results prove that rice straw may be used as fuel for close-coupled boiler-gasifier systems. Copyright © 2012 Elsevier Ltd. All rights reserved.

Straw Gasification in a Two-Stage Gasifier

DEFF Research Database (Denmark)

Bentzen, Jens Dall; Hindsgaul, Claus; Henriksen, Ulrik Birk

2002-01-01

- and to maintain a high fuel reactivity, a mixture of phosphorus acid, calcium hydroxide, molasses and water was mixed into the ground pellets. Following the gasifier was running continuously for more than 50 hours as planned. Several tar, gas and particle measurements were carried out during the test, and the ash...

The UNDP/World Bank monitoring program on small scale biomass gasifiers (BTG's experience on tar measurements)

Energy Technology Data Exchange (ETDEWEB)

Knoef, H.A.M. [Biomass Technology Group BTG, Enschede (Netherlands)

2000-07-01

By the time that small-scale biomass gasifiers were 'rediscovered' and promoted for use in developing countries (1970s), UNDP and the World Bank were well aware of the pitfalls of previous attempts to diffuse decentralized energy technologies. Therefore they decided to initiate a technology assessment programme before endorsing and/or stimulating a widespread gasifier introduction programme in developing countries. On July 1, 1983, the UNDP/WB worldwide Small-scale biomass gasifier monitoring was initiated, which was to {sup c}ollect uniform data on the actual field performance, economics, safety and public acceptability of biomass gasifiers currently operating in developing countries{sup .} For the UNDP/WB program BTG developed a tar measuring protocol which was used at twenty gasifiers worldwide (Indonesia, Philippines, Brazil, Mali, Seychelles, Vanuatu and Burundi). Other parameters monitored include pressure and temperatures at various spots, gasflow, fuel consumption, lubrication oil analyses, gas-composition analyses, emission measurements. The seven year programme showed that most of donor funded projects failed, mainly because there was not sufficient commitment from involved parties. National programs on the utilization of loca available biomass resources mostly failed because the fuel did not suit the requirements of gasifier reactor. In case of proper project design/set-up most of the small scale biomass gasifiers operated without major problems. Examples of such projects are the ones in Balong and Majalengka (Indonesia) Onesua (Vanuatu), Espara Feliz (Brazil) and Dogofiry (Mali). A motivated team of technicians, operators, managers is one the most important items within this respect. Most of the heat gasifiers are installed commercially and are much more successful compared to the subsidized power gasifiers. Local manufactured gasifiers are generally constructed of low quality materials causing frequent technical problems. However, locally

Uncertainty Quantification Analysis of Both Experimental and CFD Simulation Data of a Bench-scale Fluidized Bed Gasifier

Energy Technology Data Exchange (ETDEWEB)

Shahnam, Mehrdad [National Energy Technology Lab. (NETL), Morgantown, WV (United States). Research and Innovation Center, Energy Conversion Engineering Directorate; Gel, Aytekin [ALPEMI Consulting, LLC, Phoeniz, AZ (United States); Subramaniyan, Arun K. [GE Global Research Center, Niskayuna, NY (United States); Musser, Jordan [National Energy Technology Lab. (NETL), Morgantown, WV (United States). Research and Innovation Center, Energy Conversion Engineering Directorate; Dietiker, Jean-Francois [West Virginia Univ. Research Corporation, Morgantown, WV (United States)

2017-10-02

Adequate assessment of the uncertainties in modeling and simulation is becoming an integral part of the simulation based engineering design. The goal of this study is to demonstrate the application of non-intrusive Bayesian uncertainty quantification (UQ) methodology in multiphase (gas-solid) flows with experimental and simulation data, as part of our research efforts to determine the most suited approach for UQ of a bench scale fluidized bed gasifier. UQ analysis was first performed on the available experimental data. Global sensitivity analysis performed as part of the UQ analysis shows that among the three operating factors, steam to oxygen ratio has the most influence on syngas composition in the bench-scale gasifier experiments. An analysis for forward propagation of uncertainties was performed and results show that an increase in steam to oxygen ratio leads to an increase in H2 mole fraction and a decrease in CO mole fraction. These findings are in agreement with the ANOVA analysis performed in the reference experimental study. Another contribution in addition to the UQ analysis is the optimization-based approach to guide to identify next best set of additional experimental samples, should the possibility arise for additional experiments. Hence, the surrogate models constructed as part of the UQ analysis is employed to improve the information gain and make incremental recommendation, should the possibility to add more experiments arise. In the second step, series of simulations were carried out with the open-source computational fluid dynamics software MFiX to reproduce the experimental conditions, where three operating factors, i.e., coal flow rate, coal particle diameter, and steam-to-oxygen ratio, were systematically varied to understand their effect on the syngas composition. Bayesian UQ analysis was performed on the numerical results. As part of Bayesian UQ analysis, a global sensitivity analysis was performed based on the simulation results, which shows

Advanced One-Dimensional Entrained-Flow Gasifier Model Considering Melting Phenomenon of Ash

Directory of Open Access Journals (Sweden)

Jinsu Kim

2018-04-01

Full Text Available A one-dimensional model is developed to represent the ash-melting phenomenon, which was not considered in the previous one-dimensional (1-D entrained-flow gasifier model. We include sensible heat of slag and the fusion heat of ash in the heat balance equation. To consider the melting of ash, we propose an algorithm that calculates the energy balance for three scenarios based on temperature. We also use the composition and the thermal properties of anorthite mineral to express ash. gPROMS for differential equations is used to solve this algorithm in a simulation; the results include coal conversion, gas composition, and temperature profile. Based on the Texaco pilot plant gasifier, we validate our model. Our results show good agreement with previous experimental data. We conclude that the sensible heat of slag and the fusion heat of ash must be included in the entrained flow gasifier model.

Date palm waste gasification in downdraft gasifier and simulation using ASPEN HYSYS

International Nuclear Information System (INIS)

Bassyouni, M.; Waheed ul Hasan, Syed; Abdel-Aziz, M.H.; Abdel-hamid, S.M.-S.; Naveed, Shahid; Hussain, Ahmed; Ani, Farid Nasir

2014-01-01

Highlights: • Simulation of date palm waste gasification using ASPEN HYSYS was studied. • A steady state simulation of downdraft gasifier has been developed. • The results were used to predict synthesis gas composition. • Simulation results and experimental results are in good agreement. - Abstract: The present research aims to study the simulation of date palm waste gasification using ASPEN HYSYS. A steady state simulation of downdraft gasifier firing date palm leaves has been developed. The model is able to predict syngas composition with sound accuracy and can be used to find optimal operating conditions of the gasifier. Biomass is defined as an unconventional hypothetical solid component in HYSYS. A set of six reactor models simulates various reaction zones of the downdraft gasifier in accordance with its hydrodynamics. Biomass decomposition into constituents in the pyrolysis zone is modeled with a conversion reactor. The combustion of char and volatiles in the combustion zone are modeled with equilibrium and Gibbs reactor models respectively. The gasification zone is modeled with a Gibbs and equilibrium reactor. The results of simulation are validated against experimental results of a parametric variability study on a lab scale gasifier. The proportion of synthesis gas increase as temperature increases (concentration, molar fraction, and partial pressure). CO 2 and CH 4 in the product gases were also found to decrease with increasing temperature. At 800 °C, the exit gas reaches a stable molar composition (H 2 = 56.27%, CO = 21.71%, CO 2 = 18.24%, CH 4 = 3.78%). Increasing steam to biomass ratio increases CO 2 and H 2 at the expense of CO, governed by shift reaction. Steam induction increases the methane contents, thereby improves the heating value of the product gas

Date palm waste gasification in downdraft gasifier and simulation using ASPEN HYSYS

Energy Technology Data Exchange (ETDEWEB)

Bassyouni, M. [Department of Chemical and Materials Engineering, King Abdulaziz University, Rabigh 21911 (Saudi Arabia); Department of Chemical Engineering, Higher Technological Institute, Tenth of Ramdan City (Egypt); Waheed ul Hasan, Syed [Department of Chemical and Materials Engineering, King Abdulaziz University, Rabigh 21911 (Saudi Arabia); Abdel-Aziz, M.H., E-mail: helmy2002@gmail.com [Department of Chemical and Materials Engineering, King Abdulaziz University, Rabigh 21911 (Saudi Arabia); Chemical Engineering Department, Faculty of Engineering, Alexandria University, Alexandria (Egypt); Abdel-hamid, S. M.-S. [Department of Chemical Engineering, Higher Technological Institute, Tenth of Ramdan City (Egypt); Naveed, Shahid [Punjab Institute of Contemporary Sciences, 5.5 KM Raiwind Road, Lahore (Pakistan); Hussain, Ahmed [Department of Nuclear Engineering, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Ani, Farid Nasir [Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, UTM 81310 Johor Bahru (Malaysia)

2014-12-15

Highlights: • Simulation of date palm waste gasification using ASPEN HYSYS was studied. • A steady state simulation of downdraft gasifier has been developed. • The results were used to predict synthesis gas composition. • Simulation results and experimental results are in good agreement. - Abstract: The present research aims to study the simulation of date palm waste gasification using ASPEN HYSYS. A steady state simulation of downdraft gasifier firing date palm leaves has been developed. The model is able to predict syngas composition with sound accuracy and can be used to find optimal operating conditions of the gasifier. Biomass is defined as an unconventional hypothetical solid component in HYSYS. A set of six reactor models simulates various reaction zones of the downdraft gasifier in accordance with its hydrodynamics. Biomass decomposition into constituents in the pyrolysis zone is modeled with a conversion reactor. The combustion of char and volatiles in the combustion zone are modeled with equilibrium and Gibbs reactor models respectively. The gasification zone is modeled with a Gibbs and equilibrium reactor. The results of simulation are validated against experimental results of a parametric variability study on a lab scale gasifier. The proportion of synthesis gas increase as temperature increases (concentration, molar fraction, and partial pressure). CO{sub 2} and CH{sub 4} in the product gases were also found to decrease with increasing temperature. At 800 °C, the exit gas reaches a stable molar composition (H{sub 2} = 56.27%, CO = 21.71%, CO{sub 2} = 18.24%, CH{sub 4} = 3.78%). Increasing steam to biomass ratio increases CO{sub 2} and H{sub 2} at the expense of CO, governed by shift reaction. Steam induction increases the methane contents, thereby improves the heating value of the product gas.

[Tampa Electric Company IGCC project]. 1996 DOE annual technical report, January--December 1996

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

Tampa Electric Company`s Polk Power Station Unit 1 (PPS-1) Integrated Gasification Combined Cycle (IGCC) demonstration project uses a Texaco pressurized, oxygen-blown, entrained-flow coal gasifier to convert approximately 2,000 tons per day of coal to syngas. The gasification plant is coupled with a combined cycle power block to produce a net 250 MW electrical power output. Coal is slurried in water, combined with 95% pure oxygen from an air separation unit, and sent to the gasifier to produce a high temperature, high pressure, medium-Btu syngas with a heat content of about 250 BTUs/cf (HHV). The syngas then flows through a high temperature heat recovery unit which cools the syngas prior to its entering the cleanup systems. Molten coal ash flows from the bottom of the high temperature heat recovery unit into a water-filled quench chamber where it solidifies into a marketable slag by-product. Approximately 10% of the raw, hot syngas at 900 F is designed to pass through an intermittently moving bed of metal-oxide sorbent which removes sulfur-bearing compounds from the syngas. PPS-1 will be the first unit in the world to demonstrate this advanced metal oxide hot gas desulfurization technology on a commercial unit. The emphasis during 1996 centered around start-up activities.

Decomposition of tar in gas from updraft gasifier by thermal cracking

DEFF Research Database (Denmark)

Brandt, Peder; Henriksen, Ulrik Birk

2000-01-01

Continuing earlier work with tar reduction by partial oxidation of pyrolysis gas [1] thermal cracking has been evaluated as a gas cleaning process. The work has been focusing on cleaning gas from updraft gasifiers, and the long term purpose is to develop a tar cleaning unit based on thermal...... cracking. An experimental set-up has been built, in which a flow of contaminated gas can be heated up to 1290°C in a reactor made of pure Al2O3. Four measurements were made. Three with gas from a pyrolysis unit simulating updraft gasifier, and one with gas from an updraft gasifier. Cracking temperatures...... was 1200, 1250 and 1290°C, and the residence time at this temperature was 0.5 second. The measurements show that at the selected residence time of 0.5 second, the gas flow in a thermal tar cracking unit has to be heated to at least 1250°C to achieve sufficient tar cleaning. At 1290°C, a tar content as low...

Techno-economic analysis of lignite fuelled IGCC with CO{sub 2} capture. Comparing fluidized bed and entrained flow gasifiers

Energy Technology Data Exchange (ETDEWEB)

Liu, Guangjian; Wu, Zhen; Zhang, Haiying [North China Electric Power Univ., Beijing (China). School of Energy and Power Engineering

2013-07-01

Integrated coal gasification combined cycle (IGCC) plants with pre-combustion capture of CO{sub 2} represent one of the most promising options for generating low-cost decarbonized power using bituminous coals. This work systematically quantify the effect of coal rank on the efficiency and economics of IGCC systems with CO2 capture and storage (CCS), with a special focus on comparison of systems using fluidized-bed gasifier (U-GAS) and entrained flow gasifier (Shell). It was found that the Shell IGCCs are little affect by low rank coal after pre-drying in terms of thermal efficiency and the levelized cost of electricity (LCOE) is only increase by 2-6% for lignite cases with and without CCS compared with bituminous coal cases. The specific CO{sub 2} emissions of U-GAS gasifier based lignite fuelled IGCC with CCS is 198 g/kWhe, almost two times of shell gasifier cases, mainly due to lower carbon conversion in the gasifier and the higher methane in the raw gas of gasifier. However, the total capital cost and COE of U-Gas IGCCs are 15-20% less than that of Shell IGCCs because of lower capital cost of gasifier, coal drying units and air separate units per kWe.

Thermodynamic modeling of small scale biomass gasifiers: Development and assessment of the ''Multi-Box'' approach.

Science.gov (United States)

Vakalis, Stergios; Patuzzi, Francesco; Baratieri, Marco

2016-04-01

Modeling can be a powerful tool for designing and optimizing gasification systems. Modeling applications for small scale/fixed bed biomass gasifiers have been interesting due to their increased commercial practices. Fixed bed gasifiers are characterized by a wide range of operational conditions and are multi-zoned processes. The reactants are distributed in different phases and the products from each zone influence the following process steps and thus the composition of the final products. The present study aims to improve the conventional 'Black-Box' thermodynamic modeling by means of developing multiple intermediate 'boxes' that calculate two phase (solid-vapor) equilibriums in small scale gasifiers. Therefore the model is named ''Multi-Box''. Experimental data from a small scale gasifier have been used for the validation of the model. The returned results are significantly closer with the actual case study measurements in comparison to single-stage thermodynamic modeling. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sulfate reduction in an entrained-flow black liquor gasifier

Energy Technology Data Exchange (ETDEWEB)

Kymaelaeinen, M.; Janka, K. [Tampella Power, Tampere (Finland); Frederick, W.J.; Littau, M.; Sricharoenchaikul, V.; Jivakanun, N.; Waag, K. [Oregon State Univ., Corvallis, OR (United States). Dept. of Chemical Engineering

1995-12-31

Sulfate reduction and carbon conversion during pyrolysis and gasification of black liquor particles were experimentally studied in a laminar entrained-flow reactor. A model was also developed to simulate an entrained-flow black liquor gasifier. Experimental results were then compared to model calculations. Results indicated that carbon must be present to get a high degree of sulfate reduction during gasification. It is therefore important to balance the rates of carbon conversion and sulfate reduction. High local temperatures in the reactor should be avoided so that carbon does not convert too rapidly, but temperatures of nearly 1000 degrees C are required to achieve good sulfate reduction. It was suggested that a new equation was needed to adequately predict sulfate reduction in an entrained-flow black liquor gasifier. 12 refs., 8 figs., 5 tabs.

High temperature corrosion in gasifiers

Directory of Open Access Journals (Sweden)

Bakker Wate

2004-01-01

Full Text Available Several commercial scale coal gasification combined cycle power plants have been built and successfully operated during the last 5-10 years. Supporting research on materials of construction has been carried out for the last 20 years by EPRI and others. Emphasis was on metallic alloys for heat exchangers and other components in contact with hot corrosive gases at high temperatures. In this paper major high temperature corrosion mechanisms, materials performance in presently operating gasifiers and future research needs will be discussed.

Results with a bench scale downdraft biomass gasifier for agricultural and forestry residues

Energy Technology Data Exchange (ETDEWEB)

Olgun, Hayati [TUBITAK Marmara Research Center, Energy Institute, P.O. Box 21, 41470 Gebze, Kocaeli (Turkey); Ozdogan, Sibel; Yinesor, Guzide [Marmara University-Goztepe Campus, Faculty of Engineering - Department of Mechanical Engineering, 34722 Kuyubasi Kadikoy Istanbul (Turkey)

2011-01-15

A small scale fixed bed downdraft gasifier system to be fed with agricultural and forestry residues has been designed and constructed. The downdraft gasifier has four consecutive reaction zones from the top to the bottom, namely drying, pyrolysis, oxidation and reduction zones. Both the biomass fuel and the gases move in the same direction. A throat has been incorporated into the design to achieve gasification with lower tar production. The experimental system consists of the downdraft gasifier and the gas cleaning unit made up by a cyclone, a scrubber and a filter box. A pilot burner is utilized for initial ignition of the biomass fuel. The product gases are combusted in the flare built up as part of the gasification system. The gasification medium is air. The air to fuel ratio is adjusted to produce a gas with acceptably high heating value and low pollutants. Within this frame, different types of biomass, namely wood chips, barks, olive pomace and hazelnut shells are to be processed. The developed downdraft gasifier appears to handle the investigated biomass sources in a technically and environmentally feasible manner. This paper summarizes selected design related issues along with the results obtained with wood chips and hazelnut shells. (author)

Comparison of Shell, Texaco, BGL and KRW gasifiers as part of IGCC plant computer simulations

Energy Technology Data Exchange (ETDEWEB)

Zheng, L.; Furimsky, E. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Energy Technology Centre

2005-07-01

The performances of four IGCC plants employing Shell, Texaco, BGL and KRW gasifiers were simulated using ASPEN Plus software for three different feeds. Performance analyses and comparisons of all four IGCC plants were performed based on the established data bank from the simulation. Discussions were focused on gas compositions, gasifier selection and overall performance.

Exergetic optimisation of a production process of Fischer-Tropsch fuels from biomass

NARCIS (Netherlands)

Prins, M.J.; Ptasinski, K.J.; Janssen, F.J.J.G.

2005-01-01

An exergy analysis of Biomass Integrated Gasification-Fischer–Tropsch process is presented. The process combines an air-blown, atmospheric gasifier, using sawdust as feedstock, with a Fischer–Tropsch reactor and a steam-Rankine cycle for electricity generation from the Fischer–Tropsch tail gas.

Comparison of Refractory Performance in Black Liquor Gasifiers and a Smelt Test System

International Nuclear Information System (INIS)

Peascoe, RA

2001-01-01

Prior laboratory corrosion studies along with experience at the black liquor gasifier in New Bern, North Carolina, clearly demonstrate that serious material problems exist with the gasifier's refractory lining. Mullite-based and alumina-based refractories used at the New Bern facility suffered significant degradation even though they reportedly performed adequately in smaller scale systems. Oak Ridge National Laboratory's involvement in the failure analysis, and the initial exploration of suitable replacement materials, led to the realization that a simple and reliable, complementary method for refractory screening was needed. The development of a laboratory test system and its suitability for simulating the environment of black liquor gasifiers was undertaken. Identification and characterization of corrosion products were used to evaluate the test system as a rapid screening tool for refractory performance and as a predictor of refractory lifetime. Results from the test systems and pl ants were qualitatively similar

Fluid Dynamics of Pressurized, Entrained Coal Gasifiers

International Nuclear Information System (INIS)

1997-01-01

Pressurized, entrained gasification is a promising new technology for the clean and efficient combustion of coal. Its principle is to operate a coal gasifier at a high inlet gas velocity to increase the inflow of reactants, and at an elevated pressure to raise the overall efficiency of the process. Unfortunately, because of the extraordinary difficulties involved in performing measurements in hot, pressurized, high-velocity pilot plants, its fluid dynamics are largely unknown. Thus the designer cannot predict with certainty crucial phenomena like erosion, heat transfer and solid capture. In this context, we are conducting a study of the fluid dynamics of Pressurized Entrained Coal Gasifiers (PECGs). The idea is to simulate the flows in generic industrial PECGs using dimensional similitude. To this end, we employ a unique entrained gas-solid flow facility with the flexibility to recycle--rather than discard--gases other than air. By matching five dimensionless parameters, suspensions in mixtures of helium, carbon dioxide and sulfur hexafluoride simulate the effects of pressure and scale-upon the fluid dynamics of PECGs. Because it operates under cold, atmospheric conditions, the laboratory facility is ideal for detailed measurements

Test of different biomass into the IISc open-top co-current gasifier

Energy Technology Data Exchange (ETDEWEB)

Giordano, P. [Xylowatt SA, Chatel-St-Denis (Switzerland); Hasler, P. [Verenum SA, Zuerich (Switzerland); Dasappa, S. [Indian Institute of Science, Combustion Gasification and Propulsion Laboratory, Bangalore (India)

2001-07-01

This report made for the Swiss Federal Office of Energy (SFOE) describes the efforts made to demonstrate the technical feasibility of combined heat and power generation using wood gasification. The report describes a project involving a small open-top gasifier based on a design realised by the Indian Institute of Science (IISc). The tests made with various wood fuels such as clean wood chips, waste-wood chips, pecan nut shells, crushed oak briquettes, wood pellets, coffee hull pellets and chicken litter pellets are described and the results of measurements made concerning particulate matter, tar and certain organic compounds are presented. The discussion of the results shows that certain types of biomass can easily be used as a fuel for the small gasifier whereas others, such as coffee hull pellets, are less suitable. The report suggests that other possible fuels, such as olive and apricot stones, sludge from waste water treatment plant or plastic residue from refuse treatment should be tested in the gasifier. These tests could also provide the opportunity of testing appropriate gas treatment equipment at the same time.

Reaction Mechanism and Distribution Behavior of Arsenic in the Bottom Blown Copper Smelting Process

Directory of Open Access Journals (Sweden)

Qinmeng Wang

2017-08-01

Full Text Available The control of arsenic, a toxic and carcinogenic element, is an important issue for all copper smelters. In this work, the reaction mechanism and distribution behavior of arsenic in the bottom blown copper smelting process (SKS process were investigated and compared to the flash smelting process. There are obvious differences of arsenic distribution in the SKS process and flash process, resulting from the differences of oxygen potentials, volatilizations, smelting temperatures, reaction intensities, and mass transfer processes. Under stable production conditions, the distributions of arsenic among matte, slag, and gas phases are 6%, 12%, and 82%, respectively. Less arsenic is reported in the gas phase with the flash process than with the SKS process. The main arsenic species in gas phase are AsS (g, AsO (g, and As2 (g. Arsenic exists in the slag predominantly as As2O3 (l, and in matte as As (l. High matte grade is harmful to the elimination of arsenic to gas. The changing of Fe/SiO2 has slight effects on the distributions of arsenic. In order to enhance the removal of arsenic from the SKS smelting system to the gas phase, low oxygen concentration, low ratios of oxygen/ore, and low matte grade should be chosen. In the SKS smelting process, no dust is recycled, and almost all dust is collected and further treated to eliminate arsenic and recover valuable metals by other process streams.

A numerical model for chemical reaction on slag layer surface and slag layer behavior in entrained-flow gasifier

Directory of Open Access Journals (Sweden)

Liu Sheng

2013-01-01

Full Text Available The paper concerns with slag layer accumulation, chemical reaction on slag layer surface, and slag layer flow, heat and mass transfer on the wall of entrained-flow coal gasifier. A slag layer model is developed to simulate slag layer behaviors in the coal gasifier. This 3-D model can predict temperature, slag particle disposition rate, disposition particle composition, and syngas distribution in the gasifier hearth. The model is used to evaluate the effects of O2/coal ratio on slag layer behaviors.

Performance Evaluation of Throatless Gasifier Using Pine Needles as a Feedstock for Power Generation

Directory of Open Access Journals (Sweden)

Dhaundiyal Alok

2016-03-01

Full Text Available This paper deals with the performance evaluation of a throatless gasifier TG-SI-10E. Evaluation of the throatless gasifier was done in three streams, which were the thermal, design and economic aspects. It was tested with pine needles, derived from the Himalayan chir pine (Pinus roxburghii. A non-isokinetic sampling technique was used for measuring the tar and dust contents. The carbon dioxide and carbon monoxide emission at the exhaust of engine was in the range of 12.8% and 0.1-0.5% respectively. The maximum temperature of producer gas measured at the outlet of the gasifier was 505 °C. The specific biomass consumption rate of pine needles was calculated to be 1.595 kg/kWh (electrical. Specific gasification rate for the given design was found to be 107 kg/m2h. Economic evaluation was based on direct tax incidence.

Gasification - Status and Technology; Foergasning - Status och teknik

Energy Technology Data Exchange (ETDEWEB)

Held, Joergen

2011-07-15

In this report gasification and gas cleaning techniques for biomass are treated. The main reason for gasifying biomass is to refine the fuel to make it suitable for efficient CHP production, as vehicle fuel or in industrial processes. The focus is on production of synthesis gas that can be used for production of vehicle fuel and for CHP production. Depending on application different types of gasifiers, gasification techniques and process parameters are of interest. Two gasification techniques have been identified as suitable for syngas generation, mainly due to the fact that they allow the production of a nitrogen free gas out of the gasifier; Indirect atmospheric gasification and Pressurized oxygen blown gasification For CHP production there are no restrictions on the gas composition in terms of nitrogen and here air-blown gasification is of interest as well. The main challenge when it comes to gas cleaning is related to sulphur and tars. There are different concepts and alternatives to handle sulphur and tars. Some of them is based on conventional techniques with well-proven components that are commercially available while others more advantageous solutions, still need further development. The report deals to a minor extent with the conversion of syngas to synthetic fuels. The ongoing research and development of gasification techniques is extensive, both on national and international level. Although many process concepts and components have been demonstrated, there is still no full-scale plant for the production of synthetic fuels based on biomass. Factors affecting the choice of technology are plant size, operating conditions, the possibility for process integration, access to feedstock, market aspects, incentives and economic instruments et cetera. Increased competition for biofuels will inevitably lead to higher raw material costs. This in turn means that the fuel chains with high efficiency, such as biomethane through gasification and methanation, are favored

Techno-economic Analysis for the Thermochemical Conversion of Lignocellulosic Biomass to Ethanol via Acetic Acid Synthesis

Energy Technology Data Exchange (ETDEWEB)

Zhu, Yunhua; Jones, Susanne B.

2009-04-01

Biomass is a renewable energy resource that can be converted into liquid fuel suitable for transportation applications. As a widely available biomass form, lignocellulosic biomass can have a major impact on domestic transportation fuel supplies and thus help meet the Energy Independence and Security Act renewable energy goals (U.S. Congress 2007). This study performs a techno-economic analysis of the thermo chemical conversion of biomass to ethanol, through methanol and acetic acid, followed by hydrogenation of acetic acid to ethanol. The conversion of syngas to methanol and methanol to acetic acid are well-proven technologies with high conversions and yields. This study was undertaken to determine if this highly selective route to ethanol could provide an already established economically attractive route to ethanol. The feedstock was assumed to be wood chips at 2000 metric ton/day (dry basis). Two types of gasification technologies were evaluated: an indirectly-heated gasifier and a directly-heated oxygen-blown gasifier. Process models were developed and a cost analysis was performed. The carbon monoxide used for acetic acid synthesis from methanol and the hydrogen used for hydrogenation were assumed to be purchased and not derived from the gasifier. Analysis results show that ethanol selling prices are estimated to be $2.79/gallon and $2.81/gallon for the indirectly-heated gasifier and the directly-heated gasifier systems, respectively (1stQ 2008$, 10% ROI). These costs are above the ethanol market price for during the same time period ($1.50 - $2.50/gal). The co-production of acetic acid greatly improves the process economics as shown in the figure below. Here, 20% of the acetic acid is diverted from ethanol production and assumed to be sold as a co-product at the prevailing market prices ($0.40 - $0.60/lb acetic acid), resulting in competitive ethanol production costs.

Catalytic combustion of gasified waste - Experimental part. Final report

Energy Technology Data Exchange (ETDEWEB)

Jaeraas, Sven; Kusar, Henrik [Royal Institute of Technology, Stockholm (Sweden). Chemical Engineering and Technology

2003-08-01

This final report covers the work that has been performed within the project P 10547-2, 'Catalytic combustion of gasified waste - system analysis ORWARE'. This project is part of the research programme 'Energy from Waste' financed by the Swedish National Energy Administration. The project has been carried out at the division of Industrial Ecology and at the division of Chemical Technology at Royal Inst. of Technology. The aim of the project has been to study the potentials for catalytic combustion of gasified waste. The supposed end user of the technique is a smaller community in Sweden with 15,000-20,000 inhabitants. The project contains of two sub projects: an experimental part carried out at Chemical Technology and a system analysis carried out at Industrial Ecology. This report covers the experimental part of the project carried out at Chemical Technology. The aim for the experimental part has been to develop and test catalysts with long life-time and a high performance, to reduce the thermal-NO{sub x} below 5 ppm and to significantly reduce NO{sub x} formed from fuel-bound nitrogen. Different experimental studies have been carried out within the project: a set-up of catalytic materials have been tested over a synthetic mixture of the gasified waste, the influence of sulfur present in the gas stream, NO{sub x} formation from fuel bound nitrogen, kinetic studies of CO and H{sub 2} with and without the presence of water and the effects of adding a co-metal to palladium catalysts Furthermore a novel annular reactor design has been used to carry out experiments for kinetic measurements. Real gasification tests of waste pellets directly coupled to catalytic combustion have successfully been performed. The results obtained from the experiments, both the catalytic combustion and from the gasification, have been possible to use in the system analysis. The aim of the system analysis of catalytic combustion of gasified waste takes into consideration

The Design, Construction and Operation of a 75 kW Two-Stage Gasifier

DEFF Research Database (Denmark)

Henriksen, Ulrik Birk; Ahrenfeldt, Jesper; Jensen, Torben Kvist

2003-01-01

The Two-Stage Gasifier was operated for several weeks (465 hours) and of these 190 hours continuously. The gasifier is operated automatically unattended day and night, and only small adjustments of the feeding rate were necessary once or twice a day. The operation was successful, and the output...... as expected. The engine operated well on the produced gas, and no deposits were observed in the engine afterwards. The bag house filter was an excellent and well operating gas cleaning system. Small amounts of deposits consisting of salts and carbonates were observed in the hot gas heat exchangers. The top...

Biomass downdraft gasifier with internal cyclonic combustion chamber: design, construction, and experimental results.

Science.gov (United States)

Patil, Krushna; Bhoi, Prakash; Huhnke, Raymond; Bellmer, Danielle

2011-05-01

An exploratory downdraft gasifier design with unique biomass pyrolysis and tar cracking mechanism is evolved at Oklahoma State University. This design has an internal separate combustion section where turbulent, swirling high-temperature combustion flows are generated. A series of research trials were conducted using wood shavings as the gasifier feedstock. Maximum tar cracking temperatures were above 1100°C. Average volumetric concentration levels of major combustible components in the product gas were 22% CO and 11% H(2). Hot and cold gas efficiencies were 72% and 66%, respectively. Copyright © 2011 Elsevier Ltd. All rights reserved.

Achievement report (edition B) for fiscal 1999 on development of technology to manufacture coal gas for fuel cells. Studies by using pilot test facilities (Volumes for equipment fabrication and constructions, and trial run design); 1999 nendo seika hokokusho (B ban). Nenryo denchi you sekitan gas seizo gijutsu kaihatsu - Pilot setsubi ni yoru kenkyu (kisokoji kiki seisaku hen shiunten sekkei hen)

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

With an objective to develop a coal gas manufacturing system for fuel cells, research and development has been performed on a oxygen-blown coal gasifier and researches on a technology to purify gases for fuel cells. This paper summarizes the achievements in fiscal 1999. The current fiscal year has performed, among other the pilot plant construction works, execution of the above-the-ground constructions for the operation center and compressor room building, construction of the cooling water tanks, and partial improvement of roads in the plant site. In the gasifier facilities, items of equipment were fabricated, some of the outsourced articles were procured, and the installations thereof were carried out. For the gas purifying equipment, installation of the gas analyzer room was executed. In the trial run design, discussions were given on the systematic improvements in the test items, the gas sampling procedures, the unit protecting interlock, and the facility protecting logic. For the trial run design, establishment has been implemented on the efficient and functional test plans by establishing priority on the tests to be executed, so that the development items demanded in the pilot test and research can be achieved within the limited test processes. (NEDO)

Validation of Continuous CHP Operation of a Two-Stage Biomass Gasifier

DEFF Research Database (Denmark)

Ahrenfeldt, Jesper; Henriksen, Ulrik Birk; Jensen, Torben Kvist

2006-01-01

The Viking gasification plant at the Technical University of Denmark was built to demonstrate a continuous combined heat and power operation of a two-stage gasifier fueled with wood chips. The nominal input of the gasifier is 75 kW thermal. To validate the continuous operation of the plant, a 9-day...... measurement campaign was performed. The campaign verified a stable operation of the plant, and the energy balance resulted in an overall fuel to gas efficiency of 93% and a wood to electricity efficiency of 25%. Very low tar content in the producer gas was observed: only 0.1 mg/Nm3 naphthalene could...... be measured in raw gas. A stable engine operation on the producer gas was observed, and very low emissions of aldehydes, N2O, and polycyclic aromatic hydrocarbons were measured....

Optical and Mechanical Properties of Glass Blown In Vacuo

Science.gov (United States)

Manning, andrew; Tucker, Dennis; Mooney, Theodore; Herren, Kenneth; Gregory, Don A.

2006-01-01

Theoretically, the strength of glass processed in vacuum should be higher due to outgassing of contaminants normally present in the glass, such as bulk water in the form of OH bonds that tends to weaken the glass structure. In this research, small discs of a few types of glass have been subjected to various temperatures for extended periods of time in vacuum. Their strength was then tested using a standard flexure technique, facilitated by a custom-designed test fixture, and the results were compared to glass tested in air using the same fixture. The purpose of the glass blowing investigation was to prove the basic feasibility of a high-level concept for in-space manufacture of optical elements. The central requirement was that the glass bubble had to be blown into a support structure such that the bubble could be handled by manipulation of the structure. The blown bubble attached itself to a mullite ring geometrically and mechanically, as a demonstration in the initial experiments described here, by expanding through and around it. The vacuum system used was custom made, as were most of the components of the system, such as the heating element, the glass and ring support structure, and the gas inlet system that provided the pressure needed to blow the glass.

On a clean power generation system with the co-gasification of biomass and coal in a quadruple fluidized bed gasifier.

Science.gov (United States)

Yan, Linbo; He, Boshu

2017-07-01

A clean power generation system was built based on the steam co-gasification of biomass and coal in a quadruple fluidized bed gasifier. The chemical looping with oxygen uncoupling technology was used to supply oxygen for the calciner. The solid oxide fuel cell and the steam turbine were combined to generate power. The calcium looping and mineral carbonation were used for CO 2 capture and sequestration. The aim of this work was to study the characteristics of this system. The effects of key operation parameters on the system total energy efficiency (ŋ ten ), total exergy efficiency (ŋ tex ) and carbon sequestration rate (R cs ) were detected. The energy and exergy balance calculations were implemented and the corresponding Sankey and Grassmann diagrams were drawn. It was found that the maximum energy and exergy losses occurred in the steam turbine. The system ŋ ten and ŋ tex could be ∼50% and ∼47%, and R cs could be over unit. Copyright © 2017 Elsevier Ltd. All rights reserved.

Particle Distribution in a Fixed Bed Down Draft Wood Gasifier

DEFF Research Database (Denmark)

Hindsgaul, Claus

2005-01-01

Char particle samples were collected from six distances above the grate in a fixed bed of a down draft biomass gasifier. Each sample was separated into twelve size fractions by screening through standard sieves in order to determine the local particle size distribution. The ash contents of each...

The role of water content in triboelectric charging of wind-blown sand.

Science.gov (United States)

Gu, Zhaolin; Wei, Wei; Su, Junwei; Yu, Chuck Wah

2013-01-01

Triboelectric charging is common in desert sandstorms and dust devils on Earth; however, it remains poorly understood. Here we show a charging mechanism of sands with the adsorbed water on micro-porous surface in wind-blown sand based on the fact that water content is universal but usually a minor component in most particle systems. The triboelectric charging could be resulted due to the different mobility of H(+)/OH(-) between the contacting sands with a temperature difference. Computational fluid dynamics (CFD) and discrete element method (DEM) were used to demonstrate the dynamics of the sand charging. The numerically simulated charge-to-mass ratios of sands and electric field strength established in wind tunnel agreed well with the experimental data. The charging mechanism could provide an explanation for the charging process of all identical granular systems with water content, including Martian dust devils, wind-blown snow, even powder electrification in industrial processes.

Advanced gasifier and water gas shift technologies for low cost coal conversion to high hydrogen syngas

Energy Technology Data Exchange (ETDEWEB)

Kramer, Andrew Kramer [Gas Technology Inst., Des Plaines, IL (United States)

2016-09-30

The Gas Technology Institute (GTI) and team members RTI International (RTI), Coanda Research and Development, and Nexant, are developing and maturing a portfolio of technologies to meet the United States Department of Energy (DOE) goals for lowering the cost of producing high hydrogen syngas from coal for use in carbon capture power and coal-to-liquids/chemicals. This project matured an advanced pilot-scale gasifier, with scalable and commercially traceable components, to readiness for use in a first-of-a-kind commercially-relevant demonstration plant on the scale of 500-1,000 tons per day (TPD). This was accomplished through cold flow simulation of the gasifier quench zone transition region at Coanda and through an extensive hotfire gasifier test program on highly reactive coal and high ash/high ash fusion temperature coals at GTI. RTI matured an advanced water gas shift process and catalyst to readiness for testing at pilot plant scale through catalyst development and testing, and development of a preliminary design basis for a pilot scale reactor demonstrating the catalyst. A techno-economic analysis was performed by Nexant to assess the potential benefits of the gasifier and catalyst technologies in the context of power production and methanol production. This analysis showed an 18%reduction in cost of power and a 19%reduction in cost of methanol relative to DOE reference baseline cases.

Production of 800 kW of electrical power using medium calorific gas from a biomass gasifier integrated in a combined cycle

Energy Technology Data Exchange (ETDEWEB)

Gulyurtlu, I.; Cabrita, I. [Instituto Nacional de Engenharia e Tecnologia Industrial, Lisboa (Portugal)

1993-12-31

An allothermal fluidized bed biomass gasifier is under construction to operate at a pressure slightly above atmospheric to produce a gaseous fuel of medium heating value. The output of the gasifier is 2.5 {times} 10{sup 6} kcal/h and will be attached to a gas turbine that is specifically modified to burn the gas produced. The amount of electricity to be generated will be 800 kW. The gasifying medium used is superheated steam at 2.5 bars and 400{degrees}C and the amount needed will be 280 kg/h. The gasifier will have a cross sectional area of 2.1 m{sup 2} with dimensions of 1 500 mm {times} 1 400 mm. There is a heat exchanger to provide the heat needed for the gasification reactions. The gasifier will operate at about 850{degrees}C and the biomass throughput will be about 950 kg/h. The amount of gas that is to be produced will be about 1 300 kg/h or 1 900 Nm{sup 3}/h. Part of the gas obtained will be burned in an external combustor to provide the heat for the gasifier. The gas turbine to be employed is a single shaft turbine designed to drive 750 kVA electrical generator. The turbine combustion chamber is somewhat modified to allow for the lower heating value of the gas. However, there is no loss of efficiency in the turbine output due to lower calorific value of the fuel. The turbine inlet temperature is 900/{degrees}C and that of the exhaust will be 500{degrees}C. The amount of gas to be used is about 745 Nm{sup 3}/h. The paper reports the experimental results obtained from a pilot-scale gasifier operating under similar conditions. The results of test runs carried out with a gas turbine are also presented.

Design of structure and simulation of the three-zone gasifier of dense layer of the inverted process

Science.gov (United States)

Zagrutdinov, R. Sh; Negutorov, V. N.; Maliykhin, D. G.; Nikishanin, M. S.; Senachin, P. K.

2017-11-01

Experts of LLC “New Energy Technologies” have developed gasifiers designs, with the implementation of the three-zone gasification method, which satisfy the following conditions: 1) the generated gas must be free from tar, soot and hydrocarbons, with a given ratio of CO/H2; 2) to use as the fuel source a wide range of low-grade low-value solid fuels, including biomass and various kinds of carbonaceous wastes; 3) have high reliability in operation, do not require qualified operating personnel, be relatively inexpensive to produce and use steam-air blowing instead of expensive steam-oxygen one; 4) the line of standard sizes should be sufficiently wide (with a single unit capacity of fuel from 1 to 50-70 MW). Two models of gas generators of the inverted gasification process with three combustion zones operating under pressure have been adopted for design: 1) gas generator with a remote combustion chamber type GOP-VKS (two-block version) and 2) a gas generator with a common combustion chamber of the GOP-OK type (single-block version), which is an almost ideal model for increasing the unit capacity. There have been worked out various schemes for the preparation of briquettes from practically the entire spectrum of low-grade fuel: high-ash and high-moisture coals, peat and biomass, including all types of waste - solid household waste, crop, livestock, poultry, etc. In the gas generators there are gasified the cylindrical briquettes with a diameter of 20-25 mm and a length of 25-35 mm. There have been developed a mathematical model and computer code for numerical simulation of synthesis gas generation processes in a gasifier of a dense layer of inverted process during a steam-air blast, including: continuity equations for the 8 gas phase components and for the solid phase; the equation of the heat balance for the entire heterogeneous system; the Darcy law equation (for porous media); equation of state for 8 components of the gas phase; equations for the rates of 3 gas

Process for electrochemically gasifying coal using electromagnetism

Science.gov (United States)

Botts, Thomas E.; Powell, James R.

1987-01-01

A process for electrochemically gasifying coal by establishing a flowing stream of coal particulate slurry, electrolyte and electrode members through a transverse magnetic field that has sufficient strength to polarize the electrode members, thereby causing them to operate in combination with the electrolyte to electrochemically reduce the coal particulate in the slurry. Such electrochemical reduction of the coal produces hydrogen and carbon dioxide at opposite ends of the polarized electrode members. Gas collection means are operated in conjunction with the process to collect the evolved gases as they rise from the slurry and electrolyte solution.

Prepare to be blown away

CERN Multimedia

Katarina Anthony

2013-01-01

On 16 April, the TE-VSC team began identifying and repairing the LHC’s faulty radiofrequency fingers. Their main tool: an “RF ball” that will be – quite literally – blown through the beam pipe.   RF ball tests carried out in 2007. In the bellows of the LHC interconnects, you’ll find the vacuum pipe held together by some flexible metallic connectors known as “RF fingers”. These RF fingers maintain the electrical contact between the LHC magnets, ensuring the continuity of the beam pipe. As the magnets contract and expand when heated up and cooled down, the fingers preserve their connection by simply sliding over each other. However, experience has shown that the movement of the LHC magnets can cause the fingers to buckle. “It’s not a question of bad design,” explains Vincent Baglin, from TE's Vacuum, Surfaces and Coatings (TE-VSC) group. “Rather, there were slight non...

Experimental Gasification of Biomass in an Updraft Gasifier with External Recirculation of Pyrolysis Gases

Directory of Open Access Journals (Sweden)

Adi Surjosatyo

2014-01-01

Full Text Available The updraft gasifier is a simple type of reactor for the gasification of biomass that is easy to operate and has high conversion efficiency, although it produces high levels of tar. This study attempts to observe the performance of a modified updraft gasifier. A modified updraft gasifier that recirculates the pyrolysis gases from drying zone back to the combustion zone and gas outlet at reduction zone was used. In this study, the level of pyrolysis gases that returned to the combustion zone was varied, and as well as measurements of gas composition, lower heating value and tar content. The results showed that an increase in the amount of pyrolysis gases that returned to the combustion zone resulted in a decrease in the amount of tar produced. An increase in the amount of recirculated gases tended to increase the concentrations of H2 and CH4 and reduce the concentration of CO with the primary (gasification air flow held constant. Increasing the primary air flow tended to increase the amount of CO and decrease the amount of H2. The maximum of lower heating value was 4.9 MJ/m3.

Water-Blown Polyurethane Foams Showing a Reversible Shape-Memory Effect

Directory of Open Access Journals (Sweden)

Elena Zharinova

2016-11-01

Full Text Available Water-blown polyurethane (PU foams are of enormous technological interest as they are widely applied in various fields, i.e., consumer goods, medicine, automotive or aerospace industries. The discovery of the one-way shape-memory effect in PU foams provided a fresh impetus for extensive investigations on porous polymeric actuators over the past decades. High expansion ratios during the shape-recovery are of special interest when big volume changes are required, for example to fill an aneurysm during micro-invasive surgery or save space during transportation. However, the need to program the foams before each operation cycle could be a drawback impeding the entry of shape-memory polymeric (SMP foams to our daily life. Here, we showed that a reversible shape-memory effect (rSME is achievable for polyurethane water-blown semicrystalline foams. We selected commercially available crystallizable poly(ε-caprolactone-diols of different molecular weight for foams synthesis, followed by investigations of morphology, thermal, thermomechanical and shape-memory properties of obtained compositions. Densities of synthesized foams varied from 110 to 180 kg∙m−3, while peak melting temperatures were composition-dependent and changed from 36 to 47 °C, while the melting temperature interval was around 15 K. All semicrystalline foams exhibited excellent one-way SME with shape-fixity ratios slightly above 100% and shape-recovery ratios from the second cycle of 99%. The composition with broad distribution of molecular weights of poly(ε-caprolactone-diols exhibited an rSME of about 12% upon cyclic heating and cooling from Tlow = 10 °C and Thigh = 47 °C. We anticipate that our experimental study opens a field of systematic investigation of rSMEs in porous polymeric materials on macro and micro scale and extend the application of water-blown polyurethane foams to, e.g., protective covers with zero thermal expansion or even cushions adjustable to a certain body

Experimental study on the gasification characteristics of coal and orimulsion in 0.5 T/D gasifier

Energy Technology Data Exchange (ETDEWEB)

Park, Ho Young; Kim, Jong Young; An, Dal Hong; Park, Tae Jun [Korea Electric Power Corp. (KEPCO), Taejon (Korea, Republic of). Research Center

1995-12-31

For the construction of commercial plant for IGCC imported from aboard in near future, it is aimed to get gasification data, practice the gasification design capability, and develop a fundamental key technology through the experiments for different kinds of coals (Datong, Roto, Alaska) by 0.5 T/D gasifier. We performed the experiments for physical properties and reactivities on selected coals by means of Drop Tube Reactor, numerical analysis for the reactor. Throughout the characteristic studies of orimulsion gasification, feasibility studies for orimulsion gasification as a fuel for power plant be performed. With the six experiment runs for the coal gasifier, several problems were found to remedy. After remedies, the gasifier could run at good operating conditions maintaining with 200% design feed rate over 1200-1550 degree. The third and fourth gasification runs with Roto were satisfactorily completed, during which gross heating values from produced gas were 7200-8200 Kcal/Nm{sup 3}. (author). 118 refs., 145 figs.

Experimental study on the gasification characteristics of coal and orimulsion in 0.5 T/D gasifier

Energy Technology Data Exchange (ETDEWEB)

Park, Ho Young; Kim, Jong Young; An, Dal Hong; Park, Tae Jun [Korea Electric Power Corp. (KEPCO), Taejon (Korea, Republic of). Research Center

1996-12-31

For the construction of commercial plant for IGCC imported from aboard in near future, it is aimed to get gasification data, practice the gasification design capability, and develop a fundamental key technology through the experiments for different kinds of coals (Datong, Roto, Alaska) by 0.5 T/D gasifier. We performed the experiments for physical properties and reactivities on selected coals by means of Drop Tube Reactor, numerical analysis for the reactor. Throughout the characteristic studies of orimulsion gasification, feasibility studies for orimulsion gasification as a fuel for power plant be performed. With the six experiment runs for the coal gasifier, several problems were found to remedy. After remedies, the gasifier could run at good operating conditions maintaining with 200% design feed rate over 1200-1550 degree. The third and fourth gasification runs with Roto were satisfactorily completed, during which gross heating values from produced gas were 7200-8200 Kcal/Nm{sup 3}. (author). 118 refs., 145 figs.

Temperature and pressure distributions in a 400 kW{sub t} fluidized bed straw gasifier

Energy Technology Data Exchange (ETDEWEB)

Erguedenler, A.; Ghaly, A.E.; Hamdullahpur, F. [Technical Univ. of Nova Scotia, Halifax (Canada)

1993-12-31

The temperature and pressure distribution characteristics of a 400 kW (thermal) dual-distributor type fluidized bed straw gasifier were investigated. The effects of the bed height, equivalence ratio (actual air-fuel ratio:stoichiometric air-fuel ratio) and fluidization velocity on the temperature and pressure variations in the gasifier were studied. Generally, the bed temperature reached the steady state condition within 15--20 minutes. The average temperature of the dense bed ranged from 649{degrees}C to 875{degrees}C depending on the levels of operating parameters used. The bed temperature increased linearly with increases in the equivalence ratio, higher bed temperatures were observed with lower bed height and no clear trend for the bed temperature with respect to variations in fluidization velocity was observed. The bed height, equivalence ratio and fluidization velocity affected the pressure drop in the fluidized bed gasifier. Increasing the fluidization velocity and/or decreasing the equivalence ratio resulted in higher pressure drops in the dense bed and the freeboard regions whereas increasing the bed height increased the pressure drop only in the dense bed.

Computer simulation of a downdraft wood gasifier for tea drying

Energy Technology Data Exchange (ETDEWEB)

Jayah, T.H.; Lu Aye; Fuller, R.J.; Stewart, D.F. [University of Melbourne, Victoria (Australia). International Technologies Centre, Department of Civil and Environmental Engineering

2003-10-01

A gasifier has been fabricated on Sri Lanka for the tea industry, but there is a lack of knowledge of the effect of certain key operating parameters and design features on its performance. Experimental testing of the design under various conditions has produced data that has been used to calibrate a computer program, developed to investigate the impact of those parameters and features on conversion efficiency. The program consists of two sub-models of the pyrolysis and gasification zones, respectively. The pyrolysis sub-model has been used to determine the maximum temperature and the composition of the gas entering the gasification zone. The gasification zone sub-model has been calibrated using data gathered from the experiments. It was found that a wood chip size of 3-5 cm with a moisture content below 15% (d.b.) should be used in this gasifier. Feed material with a fixed carbon content of higher than 30% and heat losses of more than 15% should be avoided. For the above parameters, the gasification zone should be 33 cm long to achieve an acceptable conversion efficiency. (author)

Thermodynamic Model of a Very High Efficiency Power Plant based on a Biomass Gasifier, SOFCs, and a Gas Turbine

Directory of Open Access Journals (Sweden)

P V Aravind

2012-07-01

Full Text Available Thermodynamic calculations with a power plant based on a biomass gasifier, SOFCs and a gas turbine are presented. The SOFC anode off-gas which mainly consists of steam and carbon dioxides used as a gasifying agent leading to an allothermal gasification process for which heat is required. Implementation of heat pipes between the SOFC and the gasifier using two SOFC stacks and intercooling the fuel and the cathode streams in between them has shown to be a solution on one hand to drive the allothermal gasification process and on the other hand to cool down the SOFC. It is seen that this helps to reduce the exergy losses in the system significantly. With such a system, electrical efficiency around 73% is shown as achievable.

Production of pulsed atomic oxygen beams via laser vaporization methods

International Nuclear Information System (INIS)

Brinza, D.E.; Coulter, D.R.; Liang, R.H.; Gupta, A.

1987-01-01

Energetic pulsed atomic oxygen beams were generated by laser-driven evaporation of cryogenically frozen ozone/oxygen films and thin films of indium-tin oxide (ITO). Mass and energy characterization of beams from the ozone/oxygen films were carried out by mass spectrometry. The peak flux, found to occur at 10 eV, is estimated from this data to be 3 x 10(20) m(-2) s(-1). Analysis of the time-of-flight data indicates a number of processes contribute to the formation of the atomic oxygen beam. The absence of metastable states such as the 2p(3) 3s(1) (5S) level of atomic oxygen blown off from ITO films is supported by the failure to observe emission at 777.3 nm from the 2p(3) 3p(1) (5P/sub J/) levels. Reactive scattering experiments with polymer film targets for atomic oxygen bombardment are planned using a universal crossed molecular beam apparatus

On generalization of electric field strength in longitudinally blown arcs

OpenAIRE

Yas'ko, O.I.; Esipchuk, A.M.; Qing, Z.; Schram, D.C.; Fauchais, P.

1997-01-01

Generalization of av. elec. field strength for different discharge conditions in longitudinally blown arcs is considered. Exptl. data for distinctive devices and different gases were used for phys. modeling. Anal. showed that heat transfer processes are responsible for I-E characteristic formation. Turbulent heat transfer is the most effective for atm. pressure discharges while convection plays the main role in vacuum arcs. A generalized I-E characteristic was obtained. [on SciFinder (R)

Sampling of contaminants from product gases of biomass gasifiers

Energy Technology Data Exchange (ETDEWEB)

Staahlberg, P.; Lappi, M.; Kurkela, E.; Simell, P.; Oesch, P.; Nieminen, M. [VTT Energy, Espoo (Finland). New Energy Technologies

1998-12-01

Reliable sampling and analysis of products from biomass gasification are essential for the successful process development and economical operation of commercial gasifiers. One of the most important and most difficult analytical tasks is to characterise the emissions from the gasifiers. This report presents a review of the sampling and analytical systems employed and developed when doing research on coal and biomass gasification. In addition to the sampling systems published in the literature, experiences obtained in various biomass gasification R and D projects of VTT in 1985-1995 are described. The present sampling methods used for different gas contaminants at VTT are also briefly presented. This report focuses mainly on the measurement of tars, nitrogen compounds and sulphur gases. Isokinetic and non-isokinetic sampling train systems are described and, in addition, special sampling apparatus based on liquid-quenched probe and gas dilution is briefly outlined. Sampling of tars with impinger systems and sampling of heavy tars with filter techniques are described in detail. Separate sampling of particulates is briefly discussed. From inorganic compounds the sampling systems used for H{sub 2}S and other sulphur gases, NH{sub 3} and HCN and HCl are presented. Proper storage of the samples is also included in the report. (orig.) 90 refs.

Gas generation by co-gasification of biomass and coal in an autothermal fluidized bed gasifier

International Nuclear Information System (INIS)

Wang, Li-Qun; Chen, Zhao-Sheng

2013-01-01

In this study, thermochemical biomass and coal co-gasification were performed on an autothermal fluidized bed gasifier, with air and steam as oxidizing and gasifying media. The experiments were completed at reaction temperatures of 875 °C–975 °C, steam-to-biomass ratio of 1.2, and biomass-to-coal ratio of 4. This research aims to determine the effects of reaction temperature on gas composition, lower heating value (LHV), as well as energy and exergy efficiencies, of the product gas. Over the ranges of the test conditions used, the product gas LHV varies between 12 and 13.8 MJ/Nm 3 , and the exergy and energy efficiencies of the product gas are in the ranges of 50.7%–60.8% and 60.3%–85.1%, respectively. The results show that high reaction temperature leads to higher H 2 and CO contents, as well as higher exergy and energy efficiencies of the product gas. In addition, gas LHV decreases with temperature. The molar ratio of H 2 /CO is larger than 1 at temperatures above 925 °C. Our experimental analysis shows that co-gasification of biomass and coal in an autothermal fluidized bed gasifier for gas production is feasible and promising. -- Highlights: • An innovative steam co-gasification process for gas production was proposed. • Co-gasification of biomass and coal in an autothermal fluidized bed gasifier was tested. • High temperature favors H 2 production. • H 2 and CO contents increase, whereas CO 2 and CH 4 levels decrease with increase in T. • Exergy and energy efficiencies of gases increase with increase in T

Sustainable model for financial viability of decentralized biomass gasifier based power projects

NARCIS (Netherlands)

Palit, D.; Malhotra, R.; Kumar, Atul

2011-01-01

This paper made a modest attempt for designing a sustainable model for financial viability of biomass gasifier power projects for enhancing electricity access in India and other developing countries. For long term sustainability of distributed generation projects in remote rural areas, viability

Results from tests of a Stirling engine and wood chips gasifier plant

DEFF Research Database (Denmark)

Carlsen, Henrik; Bovin, Jonas Kabell; Werling, J.

2002-01-01

The combination of thermal gasification and a Stirling engine is an interesting concept for use in small Combined Heat and Power (CHP) plants based on biomass, because the need for gas cleaning is eliminated and problems with fouling of the Stirling engine heater are considerably reduced....... Furthermore, the overall electric efficiency of the system can be improved. At the Technical University of Denmark a small CHP plant based on a Stirling engine and an updraft gasifier has been developed and tested successfully. The advantages of updraft gasifiers are the simplicity and that the amount...... of the Stirling engine reduces the problems with tar to a minor problem in the design of the burner. The Stirling engine, which has an electric power output of 35 kW, is specifically designed for utilisation of fuels with a content of particles. The gas burner for the engine is designed for low specific energy...

FY 1991 report on the results of the demonstration test on the methanol conversion at oil-fired power plant. Feasibility study of a new system for the stabilized supply of fuel use methanol; 1991 nendo sekiyu karyoku hatsudensho metanoru tenkan tou jissho shiken. Nenryo you metanoru kyokyu antei ka no tameno shin system no kanosei chosa hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1992-03-01

As a part of the project on the demonstration test on the methanol conversion at oil-fired power plant, feasibility study was made of a new system for methanol production by using abundant hydraulic power energy overseas and by combining water electrolysis and coal gasification technology, and the FY 1991 results were summarized. As a result of the survey, the following were selected as water electrolysis facilities: high efficiency/high current density/simplification system and solid polyelectrolyte electrolysis system with a high purity of hydrogen gas. As the coal gasifier, the oxygen blown furnace was selected which has a high carbon utilization factor, is able to gasify coal at high pressure, has no unnecessary N{sub 2}, and is being used in the integrated coal gasification combined cycle power system. As methanol synthesis facilities, the MGC/MHI method super converter was selected. Assuming the output of hydroelectric power generation to be 4,000MW, conceptual design of the optimum system was made. The methanol cost was estimated under the conditions written below: cost of hydroelectric power generation at site: 2-5 yen/kWh, coal unit price at site: 5,000-6,000 yen/t, transportation distance: 5,000-10,000 km. (NEDO)

A laser-based sensor for measurement of off-gas composition and temperature in basic oxygen steelmaking

International Nuclear Information System (INIS)

Ottesen, D.; Allendorf, S.; Ludowise, P.; Hardesty, D.; Miller, T.; Goldstein, D.; Smith, C.; Bonin, M.

1999-01-01

We are developing an optical sensor for process control in basic oxygen steelmaking. The sensor measures gas temperature and relative CO/CO 2 concentration ratios in the furnace off-gas by transmitting the laser probe beam directly above the furnace lip and below the exhaust hood during oxygen blowing. Dynamic off-gas information is being evaluated for optimizing variables such as lance height, oxygen flow, post-combustion control, and prediction of final melt-carbon content. The non-invasive nature of the optical sensor renders it robust and relatively maintenance-free. Additional potential applications of the method are process control for electric arc furnace and bottom-blown oxygen steelmaking processes. (author)

A financial evaluation of biomass-gasifier-based power generation in India

International Nuclear Information System (INIS)

Tripathi, A.K.; Iyer, P.V.R.; Kandpal, T.C.

1997-01-01

A preliminary financial evaluation of biomass-gasifier-based power generation in India was undertaken. Simple cost functions were developed and used for this purpose. The unit cost of electricity has been estimated for a variety of scenarios taking into account some of the uncertainties associated with this emerging technology in India. (author)

Design, scale-up, Six Sigma in processing different feedstocks in a fixed bed downdraft biomass gasifier

Science.gov (United States)

Boravelli, Sai Chandra Teja

This thesis mainly focuses on design and process development of a downdraft biomass gasification processes. The objective is to develop a gasifier and process of gasification for a continuous steady state process. A lab scale downdraft gasifier was designed to develop the process and obtain optimum operating procedure. Sustainable and dependable sources such as biomass are potential sources of renewable energy and have a reasonable motivation to be used in developing a small scale energy production plant for countries such as Canada where wood stocks are more reliable sources than fossil fuels. This thesis addresses the process of thermal conversion of biomass gasification process in a downdraft reactor. Downdraft biomass gasifiers are relatively cheap and easy to operate because of their design. We constructed a simple biomass gasifier to study the steady state process for different sizes of the reactor. The experimental part of this investigation look at how operating conditions such as feed rate, air flow, the length of the bed, the vibration of the reactor, height and density of syngas flame in combustion flare changes for different sizes of the reactor. These experimental results also compare the trends of tar, char and syngas production for wood pellets in a steady state process. This study also includes biomass gasification process for different wood feedstocks. It compares how shape, size and moisture content of different feedstocks makes a difference in operating conditions for the gasification process. For this, Six Sigma DMAIC techniques were used to analyze and understand how each feedstock makes a significant impact on the process.

Predictive Model to determine the composition of the gas generated in a downdraft gasifier

International Nuclear Information System (INIS)

D'Espaux Shelton, Elbis; Copa Rey, José Ramón; Brito Sauvanel, Angel Luis

2017-01-01

There is currently a trend of using gasification modeling to describe the process without the need to develop experiments, which can be costly. This work presented the necessary tools to analyze the development of a mathematical model with the objective of predicting the chemical composition of the gas generated in a fixed bed downdraft gasifier, with parallel flows and air as a gasification agent as a function of kind of biomass used and the operating parameters of the equipment. This model allows the calculation of thermochemical processes that occur inside a downdraft gasifier and also the determination of temperature profiles. The model developed was based on the energy balance and species equations approach and the control volumes method was used. (author)

Techno-economic Analysis for the Conversion of Lignocellulosic Biomass to Gasoline via the Methanol-to-Gasoline (MTG) Process

Energy Technology Data Exchange (ETDEWEB)

Jones, Susanne B.; Zhu, Yunhua

2009-05-01

Biomass is a renewable energy resource that can be converted into liquid fuel suitable for transportation applications. As a widely available biomass form, lignocellulosic biomass can have a major impact on domestic transportation fuel supplies and thus help meet the Energy Independence and Security Act renewable energy goals (U.S. Congress 2007). With gasification technology, biomass can be converted to gasoline via methanol synthesis and methanol-to-gasoline (MTG) technologies. Producing a gasoline product that is infrastructure ready has much potential. Although the MTG technology has been commercially demonstrated with natural gas conversion, combining MTG with biomass gasification has not been shown. Therefore, a techno-economic evaluation for a biomass MTG process based on currently available technology was developed to provide information about benefits and risks of this technology. The economic assumptions used in this report are consistent with previous U.S. Department of Energy Office of Biomass Programs techno-economic assessments. The feedstock is assumed to be wood chips at 2000 metric ton/day (dry basis). Two kinds of gasification technologies were evaluated: an indirectly-heated gasifier and a directly-heated oxygen-blown gasifier. The gasoline selling prices (2008 USD) excluding taxes were estimated to be $3.20/gallon and $3.68/gallon for indirectly-heated gasified and directly-heated. This suggests that a process based on existing technology is economic only when crude prices are above $100/bbl. However, improvements in syngas cleanup combined with consolidated gasoline synthesis can potentially reduce the capital cost. In addition, improved synthesis catalysts and reactor design may allow increased yield.

Cost and operational acceptability improvements to gasifiers

Energy Technology Data Exchange (ETDEWEB)

Connor, A.

2003-07-01

This work reports on the operation of two gasifiers by Biomass Engineering Ltd. in Northern Ireland, and the simplification of their gas conditioning system. Details are given of the high tar destruction levels achieved, the locally available wood waste and pallet wood, and the use of a back-pulsable dry ceramic filtration system for removing trace organics and particulates from the resulting gas prior to gas cooling, final filtration and use in a gas engine. The results of a techno-economic assessment of the original scrubbing system and the new ceramic filtration system indicating cost savings are presented. Further work to optimise the parameters of the filters is planned.

Product Characterization for Entrained Flow Coal/Biomass Co-Gasification

Energy Technology Data Exchange (ETDEWEB)

Maghzi, Shawn; Subramanian, Ramanathan; Rizeq, George; Singh, Surinder; McDermott, John; Eiteneer, Boris; Ladd, David; Vazquez, Arturo; Anderson, Denise; Bates, Noel

2011-09-30

The U.S. Department of Energy‘s National Energy Technology Laboratory (DOE NETL) is exploring affordable technologies and processes to convert domestic coal and biomass resources to high-quality liquid hydrocarbon fuels. This interest is primarily motivated by the need to increase energy security and reduce greenhouse gas emissions in the United States. Gasification technologies represent clean, flexible and efficient conversion pathways to utilize coal and biomass resources. Substantial experience and knowledge had been developed worldwide on gasification of either coal or biomass. However, reliable data on effects of blending various biomass fuels with coal during gasification process and resulting syngas composition are lacking. In this project, GE Global Research performed a complete characterization of the gas, liquid and solid products that result from the co-gasification of coal/biomass mixtures. This work was performed using a bench-scale gasifier (BSG) and a pilot-scale entrained flow gasifier (EFG). This project focused on comprehensive characterization of the products from gasifying coal/biomass mixtures in a high-temperature, high-pressure entrained flow gasifier. Results from this project provide guidance on appropriate gas clean-up systems and optimization of operating parameters needed to develop and commercialize gasification technologies. GE‘s bench-scale test facility provided the bulk of high-fidelity quantitative data under temperature, heating rate, and residence time conditions closely matching those of commercial oxygen-blown entrained flow gasifiers. Energy and Environmental Research Center (EERC) pilot-scale test facility provided focused high temperature and pressure tests at entrained flow gasifier conditions. Accurate matching of syngas time-temperature history during cooling ensured that complex species interactions including homogeneous and heterogeneous processes such as particle nucleation, coagulation, surface condensation, and

Product Characterization for Entrained Flow Coal/Biomass Co-Gasification

Energy Technology Data Exchange (ETDEWEB)

Maghzi, Shawn [General Electric Global Research, Niskayuna, NY (United States); Subramanian, Ramanathan [General Electric Global Research, Niskayuna, NY (United States); Rizeq, George [General Electric Global Research, Niskayuna, NY (United States); Singh, Surinder [General Electric Global Research, Niskayuna, NY (United States); McDermott, John [General Electric Global Research, Niskayuna, NY (United States); Eiteneer, Boris [General Electric Global Research, Niskayuna, NY (United States); Ladd, David [General Electric Global Research, Niskayuna, NY (United States); Vazquez, Arturo [General Electric Global Research, Niskayuna, NY (United States); Anderson, Denise [General Electric Global Research, Niskayuna, NY (United States); Bates, Noel [General Electric Global Research, Niskayuna, NY (United States)

2011-12-11

The U.S. Department of Energy's National Energy Technology Laboratory (DOE NETL) is exploring affordable technologies and processes to convert domestic coal and biomass resources to high-quality liquid hydrocarbon fuels. This interest is primarily motivated by the need to increase energy security and reduce greenhouse gas emissions in the United States. Gasification technologies represent clean, flexible and efficient conversion pathways to utilize coal and biomass resources. Substantial experience and knowledge had been developed worldwide on gasification of either coal or biomass. However, reliable data on effects of blending various biomass fuels with coal during gasification process and resulting syngas composition are lacking. In this project, GE Global Research performed a complete characterization of the gas, liquid and solid products that result from the co-gasification of coal/biomass mixtures. This work was performed using a bench-scale gasifier (BSG) and a pilot-scale entrained flow gasifier (EFG). This project focused on comprehensive characterization of the products from gasifying coal/biomass mixtures in a high-temperature, high-pressure entrained flow gasifier. Results from this project provide guidance on appropriate gas clean-up systems and optimization of operating parameters needed to develop and commercialize gasification technologies. GE's bench-scale test facility provided the bulk of high-fidelity quantitative data under temperature, heating rate, and residence time conditions closely matching those of commercial oxygen-blown entrained flow gasifiers. Energy and Environmental Research Center (EERC) pilot-scale test facility provided focused high temperature and pressure tests at entrained flow gasifier conditions. Accurate matching of syngas time-temperature history during cooling ensured that complex species interactions including homogeneous and heterogeneous processes such as particle nucleation, coagulation, surface condensation

Investigation of flow behaviour of coat/ash particles in an advanced pressurised fluidized bed gasifier (APFBG) using radiotracer technique

International Nuclear Information System (INIS)

Pant, H.J.; Sharma, V.K.; Gursharan Singh; Vidhya Kamadu, M.; Prakash, S.G.; Krishanamoorthy, S.; Ramani, N.V.S.; Sonde, R.R.

2004-01-01

Knowledge of Residence Time Distribution (RTD), Mean Residence Time (MRT) and degree of backmixing of solid phase is important for efficient operation of the coal gasifier. Radiotracer technique was used for measure RTD of coal/ash particles in a pilot-scale gasifier and obtain the values of MRT and backmixing. Lanthanum 140 labeled coal (100 g) was used as a tracer. The tracer was instantaneously injected into the coal feed line and monitored at ash and gas outlets of the gasifier using collimated scintillation detectors. The measured RTD data were treated and MRTs of coal/ash particles were determined. The treated data were simulated using tank-in-series model. The simulation RTD data indicated good degree of mixing with minor bypassing/short-circulating of coal particles. The results of the investigation were found useful for scale-up of the gasification process. (author)

The Low temperature CFB gasifier

DEFF Research Database (Denmark)

Stoholm, P.; Nielsen, Rasmus Glar; Fock, Martin W.

2003-01-01

%) particle separation by the hot secondary cyclone. The next LT-CFB experiment, currently under preparation, is expected to be on either municipal/industrial waste or animal manure. Eventually a 500 kW LT-CFB test plant scheduled for commission during summer 2003, and the anticipated primary LT......The Low Temperature Circulating Fluidised Bed (LT-CFB) gasification process aims at avoiding problems due to ash deposition and agglomeration when using difficult fuels such as agricultural biomass and many waste materials. This, as well as very simple gas cleaning, is achieved by pyrolysing...... the fuel at around 650?C in a CFB reaction chamber and subsequently gasifying the char at around 730oC in a slowly fluidised bubbling bed chamber located in the CFB particle recirculation path. In this paper the novel LT-CFB concept is further described together with the latest test results from the 50 k...

Ground tests of 120 kW(heat) biomass fired gasifier diesel installation

Energy Technology Data Exchange (ETDEWEB)

Zyssin, L.V.; Maronet, I.J.; Morshin, V.N. [Energotechnology Ltd., St. Petersburg (Russian Federation)

1996-12-31

For the 1 MW and less power range diesel gasifier power plants could be considered as one of the main energy sources. The brief information about works carried out in Russia according to this direction is presented. Data of preliminary tests for gas diesel installations are presented. (orig.)

Ground tests of 120 kW(heat) biomass fired gasifier diesel installation

Energy Technology Data Exchange (ETDEWEB)

Zyssin, L V; Maronet, I J; Morshin, V N [Energotechnology Ltd., St. Petersburg (Russian Federation)

1997-12-31

For the 1 MW and less power range diesel gasifier power plants could be considered as one of the main energy sources. The brief information about works carried out in Russia according to this direction is presented. Data of preliminary tests for gas diesel installations are presented. (orig.)

Modeling of flow conditions in down draft gasifiers using tin film models

DEFF Research Database (Denmark)

Jensen, Torben Kvist; Gøbel, Benny; Henriksen, Ulrik Birk

2003-01-01

In order to examine how an inhomogeneous char bed affects the gas flow through the bed, a dynamic model have been developed to describe the flow distribution in a down draft gasifier. The gas flow distribution through the bed was determined using a thin film model approach. The temperatures...

Statistical Investigation on Coherent Vortex Structure in Turbulent Drag Reducing Channel Flow with Blown Polymer Solution

International Nuclear Information System (INIS)

Ishitsuka, Shota; Motozawa, Masaaki; Kawaguchi, Yasuo; Iwamoto, Kaoru; Ando, Hirotomo; Senda, Tetsuya

2011-01-01

Coherent vortex structure in turbulent drag-reducing channel flow with blown polymer solution from the wall was investigated. As a statistical analysis, we carried out Galilean decomposition, swirling strength and linear stochastic estimation of the PIV data obtained by the PIV measurement in x – y plane. Reynolds number based on bulk velocity and channel height was set to 40000. As a result, the angle of shear layer that cleared up by using Galilean decomposition becomes small in the drag-reducing flow. Q3 events were observed near the shear layer. In addition, as a result of linear stochastic estimation (LSE) based on swirling strength, we confirmed that the velocity under the vortex core is strong in the water flow. This result shows Q2 (ejection) are dominant in the water flow. However, in the drag-reducing flow with blown polymer solution, the velocity above the vortex core become strong, that is, Q4 (sweep) events are relatively strong around the vortex core. This is the result of Q4 events to come from the channel center region because the polymer solution does not exist in this region. The typical structure like this was observed in the drag -reducing flow with blown polymer solution from the wall.

Modeling the emissions of a dual fuel engine coupled with a biomass gasifier-supplementing the Wiebe function.

Science.gov (United States)

Vakalis, Stergios; Caligiuri, Carlo; Moustakas, Konstantinos; Malamis, Dimitris; Renzi, Massimiliano; Baratieri, Marco

2018-03-12

There is a growing market demand for small-scale biomass gasifiers that is driven by the economic incentives and the legislative framework. Small-scale gasifiers produce a gaseous fuel, commonly referred to as producer gas, with relatively low heating value. Thus, the most common energy conversion systems that are coupled with small-scale gasifiers are internal combustion engines. In order to increase the electrical efficiency, the operators choose dual fuel engines and mix the producer gas with diesel. The Wiebe function has been a valuable tool for assessing the efficiency of dual fuel internal combustion engines. This study introduces a thermodynamic model that works in parallel with the Wiebe function and calculates the emissions of the engines. This "vis-à-vis" approach takes into consideration the actual conditions inside the cylinders-as they are returned by the Wiebe function-and calculates the final thermodynamic equilibrium of the flue gases mixture. This approach aims to enhance the operation of the dual fuel internal combustion engines by identifying the optimal operating conditions and-at the same time-advance pollution control and minimize the environmental impact.

Ash behavior and de-fluidization in low temperature circulating fluidized bed biomass gasifier

DEFF Research Database (Denmark)

Narayan, Vikas

ensures that high-alkali biomass fuels can be used without risks of bed de-fluidization. This thesis aims to understand the behavior of alkali metals and ash in the LTCFB system. The thesis work involved measurements made on bed material and product gas dust samples on a 100kW LTCFB gasifier placed......Biomass is increasingly used as a fuel for power generation. Herbaceous fuels however, contain high amounts of alkali metals which get volatilized at high temperatures and forms salts with low melting points and thus condense on pipelines, reactor surfaces and may cause de-fluidization. A Low......-Temperature Circulating Fluidized Bed System (LTCFB) gasifier allows pyrolysis and gasification of biomass to occur at low temperatures thereby improving the retention of alkali and other ash species within the system and minimizing the amount of ash species in the product gas. In addition, the low reactor temperature...

JV Task - 129 Advanced Conversion Test - Bulgarian Lignite

Energy Technology Data Exchange (ETDEWEB)

Michael Swanson; Everett Sondreal; Daniel Laudal; Douglas Hajicek; Ann Henderson; Brandon Pavlish

2009-03-27

The objectives of this Energy & Environmental Research Center (EERC) project were to evaluate Bulgarian lignite performance under both fluid-bed combustion and gasification conditions and provide a recommendation as to which technology would be the most technically feasible for the particular feedstock and also identify any potential operating issues (such as bed agglomeration, etc.) that may limit the applicability of a potential coal conversion technology. Gasification tests were run at the EERC in the 100-400-kg/hr transport reactor development unit (TRDU) on a 50-tonne sample of lignite supplied by the Bulgarian Lignite Power Project. The quality of the test sample was inferior to any coal previously tested in this unit, containing 50% ash at 26.7% moisture and having a higher heating value of 5043 kJ/kg after partial drying in preparation for testing. The tentative conclusion reached on the basis of tests in the TRDU is that oxygen-blown gasification of this high-ash Bulgarian lignite sample using the Kellogg, Brown, and Root (KBR) transport gasifier technology would not provide a syngas suitable for directly firing a gas turbine. After correcting for test conditions specific to the pilot-scale TRDU, including an unavoidably high heat loss and nitrogen dilution by transport air, the best-case heating value for oxygen-blown operation was estimated to be 3316 kJ/m{sup 3} for a commercial KRB transport gasifier. This heating value is about 80% of the minimum required for firing a gas turbine. Removing 50% of the carbon dioxide from the syngas would increase the heating value to 4583 kJ/m{sup 3}, i.e., to about 110% of the minimum requirement, and 95% removal would provide a heating value of 7080 kJ/m{sup 3}. Supplemental firing of natural gas would also allow the integrated gasification combined cycle (IGCC) technology to be utilized without having to remove CO{sub 2}. If removal of all nitrogen from the input gas streams such as the coal transport air were

Allothermal steam gasification of biomass in cyclic multi-compartment bubbling fluidized-bed gasifier/combustor - new reactor concept.

Science.gov (United States)

Iliuta, Ion; Leclerc, Arnaud; Larachi, Faïçal

2010-05-01

A new reactor concept of allothermal cyclic multi-compartment fluidized bed steam biomass gasification is proposed and analyzed numerically. The concept combines space and time delocalization to approach an ideal allothermal gasifier. Thermochemical conversion of biomass in periodic time and space sequences of steam biomass gasification and char/biomass combustion is simulated in which the exothermic combustion compartments provide heat into an array of interspersed endothermic steam gasification compartments. This should enhance unit heat integration and thermal efficiency and procure N(2)-free biosyngas with recourse neither to oxygen addition in steam gasification nor contact between flue and syngas. The dynamic, one-dimensional, multi-component, non-isothermal model developed for this concept accounts for detailed solid and gas flow dynamics whereupon gasification/combustion reaction kinetics, thermal effects and freeboard-zone reactions were tied. Simulations suggest that allothermal operation could be achieved with switch periods in the range of a minute supporting practical feasibility for portable small-scale gasification units. Copyright 2009 Elsevier Ltd. All rights reserved.

Influence of Low-Temperature Plasma Treatment on The Liquid Filtration Efficiency of Melt-Blown PP Nonwovens in The Conditions of Simulated Use of Respiratory Protective Equipment

Directory of Open Access Journals (Sweden)

Majchrzycka Katarzyna

2017-06-01

Full Text Available Filtering nonwovens produced with melt-blown technology are one of the most basic materials used in the construction of respiratory protective equipment (RPE against harmful aerosols, including bio- and nanoaerosols. The improvement of their filtering properties can be achieved by the development of quasi-permanent electric charge on the fibres. Usually corona discharge method is utilized for this purpose. In the presented study, it was assumed that the low-temperature plasma treatment could be applied as an alternative method for the manufacturing of conventional electret nonwovens for the RPE construction. Low temperature plasma treatment of polypropylene nonwovens was carried out with various process gases (argon, nitrogen, oxygen or air in a wide range of process parameters (gas flow velocity, time of treatment and power supplied to the reactor electrodes. After the modification, nonwovens were evaluated in terms of filtration efficiency of paraffin oil mist. The stability of the modification results was tested after 12 months of storage and after conditioning at elevated temperature and relative humidity conditions. Moreover, scanning electron microscopy and ATR-IR spectroscopy were used to assess changes in surface topography and chemical composition of the fibres. The modification of melt-blown nonwovens with nitrogen, oxygen and air plasma did not result in a satisfactory improvement of the filtration efficiency. In case of argon plasma treatment, up to 82% increase of filtration efficiency of paraffin oil mist was observed in relation to untreated samples. This effect was stable after 12 months of storage in normal conditions and after thermal conditioning in (70 ± 3°C for 24 h. The use of low-temperature plasma treatment was proven to be a promising improvement direction of filtering properties of nonwovens used for the protection of respiratory tract against harmful aerosols.

Investigation of sewage sludge gasification with use of flue gas as a gasifying agent

Directory of Open Access Journals (Sweden)

Maj Izabella

2017-01-01

Full Text Available The paper presents results of investigation of low-temperature sewage sludge gasification with use of flue gas as a gasifying agent. Tests were conducted in a laboratory stand, equipped with a gasification reactor designed and constructed specifically for this purpose. During presented tests, gas mixture with a composition of typical flue gases was used as a gasifying agent. The measuring system ensures online measurements of syngas composition: CO, CO2, H2, CH4. As a result of gasification process a syngas with combustible components has been obtained. The aim of the research was to determine the usability of sewage sludge for indirect cofiring in power boilers with the use of flue gas from the boiler as a gasifying agent and recirculating the syngas to the boiler’s combustion chamber. Results of presented investigation will be used as a knowledge base for industrial-scale sewage sludge gasification process. Furthermore, toxicity of solid products of the process has been determined by the use of Microtox bioassay. Before tests, solid post-gasification residues have been ground to two particle size fractions and extracted into Milli-Q water. The response of test organisms (bioluminescent Aliivibrio fischeri bacteria in reference to a control sample (bacteria exposed to 2% NaCl solution was measured after 5 and 15 minutes of exposure. The obtained toxicity results proved that thermal treatment of sewage sludge by their gasification reduces their toxicity relative to water organisms.

Bio-Based Polyols from Seed Oils for Water-Blown Rigid Polyurethane Foam Preparation

Directory of Open Access Journals (Sweden)

Paweena Ekkaphan

2016-01-01

Full Text Available The preparation of water-blown rigid polyurethane (RPUR foams using bio-based polyols from sesame seed oil and pumpkin seed oil has been reported. Polyols synthesis involved two steps, namely, hydroxylation and alcoholysis reaction. FTIR, NMR, and ESI-MS were used to monitor the process of the synthesized polyols and their physicochemical properties were determined. The resulting polyols have OH number in the range of 340–351 mg KOH/g. RPUR foams blown with water were produced from the reaction of biopolyols with commercial polymeric methylene diphenyl diisocyanate (PMDI. The proper PUR formulations can be manipulated to produce the desired material applications. These seed oil-based RPUR foams exhibited relatively high compressive strength (237.7–240.2 kPa with the density in the range of 40–45 kg/m3. Additionally, the cell foam morphology investigated by scanning electron microscope indicated that their cellular structure presented mostly polygonal closed cells. The experimental results demonstrate that these bio-based polyols can be used as an alternative starting material for RPUR production.

Comparison of ORC Turbine and Stirling Engine to Produce Electricity from Gasified Poultry Waste

Directory of Open Access Journals (Sweden)

Franco Cotana

2014-08-01

Full Text Available The Biomass Research Centre, section of CIRIAF, has recently developed a biomass boiler (300 kW thermal powered, fed by the poultry manure collected in a nearby livestock. All the thermal requirements of the livestock will be covered by the heat produced by gas combustion in the gasifier boiler. Within the activities carried out by the research project ENERPOLL (Energy Valorization of Poultry Manure in a Thermal Power Plant, funded by the Italian Ministry of Agriculture and Forestry, this paper aims at studying an upgrade version of the existing thermal plant, investigating and analyzing the possible applications for electricity production recovering the exceeding thermal energy. A comparison of Organic Rankine Cycle turbines and Stirling engines, to produce electricity from gasified poultry waste, is proposed, evaluating technical and economic parameters, considering actual incentives on renewable produced electricity.

Measurement and modeling the coefficient of restitution of char particles under simulated entrained flow gasifier conditions

Science.gov (United States)

Gibson, LaTosha M.

Inefficiencies in plant operations due to carbon loss in flyash, necessitate control of ash deposition and the handling of the slag disposal. Excessive char/ash deposition in convective coolers causes reduction in the heat transfer, both in the radiative (slagging) section and in the low-temperature convective (fouling) heating section. This can lead to unplanned shutdowns and result in an increased cost of electricity generation. CFD models for entrained flow gasification have used the average bulk coal composition to simulate slagging and ash deposition with a narrow particle size distribution (PSD). However, the variations in mineral (inorganic) and macerals (organic) components in coal have led to particles with a variation in their inorganic and organic composition after grinding as governed by their Particle Size Distribution (PSD) and mineral liberation kinetics. As a result, each particle in a PSD of coal exhibits differences in its conversion, particle trajectory within the gasifier, fragmentation, swelling, and slagging probability depending on the gasifier conditions (such as the temperature, coal to oxygen ratio, and swirling capacity of the coal injector). Given the heterogeneous behavior of char particles within a gasifier, the main objective of this work was to determine boundary conditions of char particle adhering and/or rebounding from the refractory wall or a layer of previously adhered particles. In the past, viscosity models based on the influence of ash composition have been used as the method to characterize sticking. It is well documented that carbon contributes to the non-wettability of particles. Therefore, it has been hypothesized that viscosity models would not be adequate to accurately predict the adhesion behavior of char. Certain particle wall impact models have incorporated surface tension which can account the contributions of the carbon content to the adhesive properties of a char particle. These particle wall impact models also

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.

Experimental and computational studies on a gasifier based stove

International Nuclear Information System (INIS)

Varunkumar, S.; Rajan, N.K.S.; Mukunda, H.S.

2012-01-01

Highlights: ► A simple method to calculate the fraction of HHC was devised. ► η g for stove is same as that of a downdraft gasifier. ► Gas from stove contains 5.5% of CH 4 equivalent of HHC. ► Effect of vessel size on utilization efficiency brought out clearly. ► Contribution of radiative heat transfer from char bed to efficiency is 6%. - Abstract: The work reported here is concerned with a detailed thermochemical evaluation of the flaming mode behaviour of a gasifier based stove. Determination of the gas composition over the fuel bed, surface and gas temperatures in the gasification process constitute principal experimental features. A simple atomic balance for the gasification reaction combined with the gas composition from the experiments is used to determine the CH 4 equivalent of higher hydrocarbons and the gasification efficiency (η g ). The components of utilization efficiency, namely, gasification–combustion and heat transfer are explored. Reactive flow computational studies using the measured gas composition over the fuel bed are used to simulate the thermochemical flow field and heat transfer to the vessel; hither-to-ignored vessel size effects in the extraction of heat from the stove are established clearly. The overall flaming mode efficiency of the stove is 50–54%; the convective and radiative components of heat transfer are established to be 45–47 and 5–7% respectively. The efficiency estimates from reacting computational fluid dynamics (RCFD) compare well with experiments.

Investigation of flow behaviour of coal particles in a pilot-scale fluidized bed gasifier (FBG) using radiotracer technique.

Science.gov (United States)

Pant, H J; Sharma, V K; Kamudu, M Vidya; Prakash, S G; Krishanamoorthy, S; Anandam, G; Rao, P Seshubabu; Ramani, N V S; Singh, Gursharan; Sonde, R R

2009-09-01

Knowledge of residence time distribution (RTD), mean residence time (MRT) and degree of axial mixing of solid phase is required for efficient operation of coal gasification process. Radiotracer technique was used to measure the RTD of coal particles in a pilot-scale fluidized bed gasifier (FBG). Two different radiotracers i.e. lanthanum-140 and gold-198 labeled coal particles (100 gm) were independently used as radiotracers. The radiotracer was instantaneously injected into the coal feed line and monitored at the ash extraction line at the bottom and gas outlet at the top of the gasifier using collimated scintillation detectors. The measured RTD data were treated and MRTs of coal/ash particles were determined. The treated data were simulated using tanks-in-series model. The simulation of RTD data indicated good degree of mixing with small fraction of the feed material bypassing/short-circuiting from the bottom of the gasifier. The results of the investigation were found useful for optimizing the design and operation of the FBG, and scale-up of the gasification process.

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.

Distributed Fiber Optic Sensor for On-Line Monitoring of Coal Gasifier Refractory Health

Energy Technology Data Exchange (ETDEWEB)

Wang, Anbo [Center for Photonics Technology, Blacksburgh, VA (United States); Yu, Zhihao [Center for Photonics Technology, Blacksburgh, VA (United States)

2015-11-30

This report summarizes technical progress on the program “Distributed Fiber Optic Sensor for On-Line Monitoring of Coal Gasifier Refractory Health,” funded by the National Energy Technology Laboratory of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The scope of work entails analyses of traveling grating generation technologies in an optical fiber, as well as the interrogation of the gratings to infer a distributed temperature along the fiber, for the purpose of developing a real-time refractory health condition monitoring technology for coal gasifiers. During the project period, which is from 2011-2015, three different sensing principles were studied, including four-wave mixing (FWM), coherent optical time-domain reflectometer (C-OTDR) and Brillouin optical time-domain analysis (BOTDA). By comparing the three methods, the BOTDA was selected for further development into a complete bench-top sensing system for the proposed high-temperature sensing application. Based on the input from Eastman Chemical, the industrial collaborator on this project, a cylindrical furnace was designed and constructed to simulate typical gasifier refractory temperature conditions in the laboratory, and verify the sensor’s capability to fully monitor refractory conditions on the back-side at temperatures up to 1000°C. In the later stages of the project, the sensing system was tested in the simulated environment for its sensing performance and high-temperature survivability. Through theoretical analyses and experimental research on the different factors affecting the sensor performance, a sensor field deployment strategy was proposed for possible future sensor field implementations.

Testing of downstream catalysts for tar destruction with a guard bed in a fluidised bed biomass gasifier at pilot plant scale

Energy Technology Data Exchange (ETDEWEB)

Aznar, M.P.; Frances, E.; Campos, I.J.; Martin, J.A.; Gil, J. [Saragossa Univ. (Spain). Dept. of Chemistry and Environment Engineering; Corella, J. [Complutense Univ. of Madrid (Spain). Dept. of Chemical Engineering

1996-12-31

A new pilot plant for advanced gasification of biomass in a fast fluidised bed is now fully operative at University of Saragossa, Spain. It is a `3rd generation` pilot plant. It has been built up after having used two previous pilot plants for biomass gasification. The main characteristic of this pilot plant is that it has two catalytic reactors connected in series, downstream the biomass gasifier. Such reactors, of 4 cm i.d., are placed in a slip stream in a by-pass from the main gasifier exit gas. The gasification is made at atmospheric pressure, with flow rates of 3-50 kg/in, using steam + O{sub 2} mixtures as the gasifying agent. Several commercial Ni steam-reforming catalyst are being tested under a realistic raw gas composition. Tar eliminations or destructions higher than 99 % are easily achieved. (orig.) 2 refs.

Testing of downstream catalysts for tar destruction with a guard bed in a fluidised bed biomass gasifier at pilot plant scale

Energy Technology Data Exchange (ETDEWEB)

Aznar, M P; Frances, E; Campos, I J; Martin, J A; Gil, J [Saragossa Univ. (Spain). Dept. of Chemistry and Environment Engineering; Corella, J [Complutense Univ. of Madrid (Spain). Dept. of Chemical Engineering

1997-12-31

A new pilot plant for advanced gasification of biomass in a fast fluidised bed is now fully operative at University of Saragossa, Spain. It is a `3rd generation` pilot plant. It has been built up after having used two previous pilot plants for biomass gasification. The main characteristic of this pilot plant is that it has two catalytic reactors connected in series, downstream the biomass gasifier. Such reactors, of 4 cm i.d., are placed in a slip stream in a by-pass from the main gasifier exit gas. The gasification is made at atmospheric pressure, with flow rates of 3-50 kg/in, using steam + O{sub 2} mixtures as the gasifying agent. Several commercial Ni steam-reforming catalyst are being tested under a realistic raw gas composition. Tar eliminations or destructions higher than 99 % are easily achieved. (orig.) 2 refs.

Review on fiber morphology obtained by bubble electrospinning and blown bubble spinning

Directory of Open Access Journals (Sweden)

He Ji-Huan

2012-01-01

Full Text Available Here we show an intriguing phenomenon in the bubble electrospinning process that the ruptured film might be stripped upwards by an electronic force to form a very thin and long plate-like strip, which might been received in the metal receiver as discontinuous backbone-like wrinkled materials, rather than smooth nano-fibers or microspheres. The processes are called the bubble electrospinning. The electronic force can be replaced by a blowing air, and the process is called as the blown bubble spinning. We demonstrate that the size and thickness of the ruptured film are the crucial parameters that are necessary to understand the various observations including beads and nanoporous materials. We identify the conditions required for a ruptured film to form discontinuous structure, and a critical width of the ruptured film to form a cylindrical fiber, above which a long and thin plate-like strip might be obtained, and a criterion for oscillatory jet diameter, which leads to bead morphology of the obtained fibers. The space of the adjacent beads depends on the fiber size. We anticipate our assay to be a starting point for more sophisticated study of the bubble electrospinning and the blown bubble spinning and for mass-production of both nanofibers and nanoscale discontinuous materials.

Gasification of solid waste — potential and application of co-current moving bed gasifiers

NARCIS (Netherlands)

Groeneveld, M.J.; van Swaaij, Willibrordus Petrus Maria

1979-01-01

A review is given of gasification processes for solid fuels with special emphasis on waste gasification. Although the co-current moving bed gasifier has not been under consideration for a long time, it offers interesting possibilities for waste gasification. Some operational data are given. Two

Novel intrinsic-based submodel for char particle gasification in entrained-flow gasifiers: Model development, validation and illustration

International Nuclear Information System (INIS)

Schulze, S.; Richter, A.; Vascellari, M.; Gupta, A.; Meyer, B.; Nikrityuk, P.A.

2016-01-01

Highlights: • Model resolving intra-particle species transport for char conversion was formulated. • TGA experiments of char particle conversion in gas flow were conducted. • The experimental results for char conversion validated the model. • CFD simulations of endothermic reactor with developed model were carried out. - Abstract: The final carbon conversion rate is of critical importance in the efficiency of gasifiers. Therefore, comprehensive modeling of char particle conversion is of primary interest for designing new gasifiers. This work presents a novel intrinsic-based submodel for the gasification of a char particle moving in a hot flue gas environment considering CO 2 and H 2 O as inlet species. The first part of the manuscript describes the model and its derivation. Validations against experiments carried out in this work for German lignite char are reported in the second part. The comparison between submodel predictions and experimental data shows good agreement. The importance of char porosity change during gasification is demonstrated. The third part presents the results of CFD simulations using the new submodel and a surface-based submodel for a generic endothermic gasifier. The focus of CFD simulations is to demonstrate the crucial role of intrinsic based heterogeneous reactions in the adequate prediction of carbon conversion rates.

Efficiency tests on the pyrolysis gasifier stove Peko Pe

DEFF Research Database (Denmark)

Nielsen, Per Sieverts

1996-01-01

This paper presents results from water boiling tests on the pyrolysis gasifier stove Peko Pe, which has been developed by the Norwegian Paal Wendelbo. The stove efficiency determined vary between 21 and 29% when burning dry Danish woodchips (10% moisture) with an estimated caloric value of 16 MJ...... the water content in the grass. In Adjumani refugee camp it was furthermore found that the stove was able to provide sufficient energy from solid combustion, after the pyrolysis was stopped, to boil water for additional 25-30 minutes with lid. This effect was not seen in the tests on woodchips in Denmark...

Effects of Temperature, Oxygen Partial Pressure, and Materials Selection on Slag Infiltration into Porous Refractories for Entrained-Flow Gasifiers

Science.gov (United States)

Kaneko, Tetsuya Kenneth

The penetration rate of molten mineral contents (slag) from spent carbonaceous feedstock into porous ceramic-oxide refractory linings is a critical parameter in determining the lifecycle of integrated gasification combined cycle energy production plants. Refractory linings that withstand longer operation without interruption are desirable because they can mitigate consumable and maintenance costs. Although refractory degradation has been extensively studied for many other high-temperature industrial processes, this work focuses on the mechanisms that are unique to entrained-flow gasification systems. The use of unique feedstock mixtures, temperatures from 1450 °C to 1600 °C, and oxygen partial pressures from 10-7 atm to 10-9 atm pose engineering challenges in designing an optimal refractory material. Experimentation, characterization, and modeling show that gasifier slag infiltration into porous refractory is determined by interactions between the slag and the refractory that either form a physical barrier that impedes fluid flow or induce an increased fluid viscosity that decelerates the velocity of the fluid body. The viscosity of the slag is modified by the thermal profile of the refractory along the penetration direction as well as reactions between the slag and refractory that alter the chemistry, and thereby the thermo-physical properties of the fluid. Infiltration experiments reveal that the temperature gradient inherently present along the refractory lining limits penetration. A refractory in near-isothermal conditions demonstrates deeper slag penetration as compared to one that experiences a steeper thermal profile. The decrease in the local temperatures of the slag as it travels deeper into the refractory increases the viscosity of the fluid, which in turn slows the infiltration velocity of fluid body into the pores of the refractory microstructure. With feedstock mixtures that exhibit high iron-oxide concentrations, a transition-metal-oxide, the oxygen

Evaluation of energy plantation crops in a high-throughput indirectly heated biomass gasifier

Energy Technology Data Exchange (ETDEWEB)

Paisley, M.A.; Litt, R.D. [Battelle, Columbus, OH (United States)

1993-12-31

Experiments were run in Battelle`s 10 ton per day Process Research Unit (PRU) gasifier using two high-growth, energy plantation crops -- hybrid poplar -- and an herbaceous biomass crop -- switch grass. The results show that both feedstocks provide gas production rates, product gas compositions, and heating value similar to other biomass feedstocks tested in the Battelle gasification process. The ash compositions of the switch grass and hybrid poplar feedstocks were high in potassium relative to previously tested biomass feedstocks. High growth biomass species tend to concentrate minerals such as potassium in the ash. The higher potassium content in the ash can then cause agglomeration problems in the gasification system. A method for controlling this agglomeration through the addition of small amounts (approximately 2 percent of the wood feed rate) of an additive could adequately control the agglomeration tendency of the ash. During the testing program in the PRU, approximately 50 tons of hybrid poplar and 15 tons of switch grass were gasified to produce a medium Btu product gas.

Adoption and use of a semi-gasifier cooking and water heating stove and fuel intervention in the Tibetan Plateau, China

Science.gov (United States)

Clark, S.; Carter, E.; Shan, M.; Ni, K.; Niu, H.; Tseng, J. T. W.; Pattanayak, S. K.; Jeuland, M.; Schauer, J. J.; Ezzati, M.; Wiedinmyer, C.; Yang, X.; Baumgartner, J.

2017-07-01

Improved cookstoves and fuels, such as advanced gasifier stoves, carry the promise of improving health outcomes, preserving local environments, and reducing climate-forcing air pollutants. However, low adoption and use of these stoves in many settings has limited their benefits. We aimed to improve the understanding of improved stove use by describing the patterns and predictors of adoption of a semi-gasifier stove and processed biomass fuel intervention in southwestern China. Of 113 intervention homes interviewed, 79% of homes tried the stove, and the majority of these (92%) continued using it 5-10 months later. One to five months after intervention, the average proportion of days that the semi-gasifier stove was in use was modest (40.4% [95% CI 34.3-46.6]), and further declined over 13 months. Homes that received the stove in the first batch used it more frequently (67.2% [95% CI 42.1-92.3] days in use) than homes that received it in the second batch (29.3% [95% CI 13.8-44.5] days in use), likely because of stove quality and user training. Household stove use was positively associated with reported cooking needs and negatively associated with age of the main cook, household socioeconomic status, and the availability of substitute cleaner-burning stoves. Our results show that even a carefully engineered, multi-purpose semi-gasifier stove and fuel intervention contributed modestly to overall household energy use in rural China.

Process for gasifying fuels with the recovery of rich gases

Energy Technology Data Exchange (ETDEWEB)

Jahns, F

1921-04-10

A process for gasifying fuels with recovery of water-free, rich-in-tar gases in a ring-gas-producer characterized by hot-gas-stream arising from the gasification bed of a fresh chamber in the known way is divided. One part is conducted through an old chamber, the other part is led first during the drying through the fresh fuel and with the received water-vapor also through the old chamber and then during the carbonization with the carbonization products is led to the carbonization-gas conduit.

A dual fired downdraft gasifier system to produce cleaner gas for power generation: Design, development and performance analysis

International Nuclear Information System (INIS)

Raman, P.; Ram, N.K.; Gupta, Ruchi

2013-01-01

The existing biomass gasifier systems have several technical challenges, which need to be addressed. They are reduction of impurities in the gas, increasing the reliability of the system, easy in operation and maintenance. It is also essential to have a simple design of gasifier system for power generation, which can work even in remote locations. A dual fired downdraft gasifier system was designed to produce clean gas from biomass fuel, used for electricity generation. This system is proposed to overcome a number of technical challenges. The system is equipped with dry gas cleaning and indirect gas cooling equipment. The dry gas cleaning system completely eliminates wet scrubbers that require large quantities of water. It also helps to do away with the disposal issues with the polluted water. With the improved gasifier system, the tar level in the raw gas is less than 100 mg Nm −3 .Cold gas efficiency has improved to 89% by complete gasification of biomass and recycling of waste heat into the reactor. Several parameters, which are considered in the design and development of the reactors, are presented in detail with their performance indicators. - Highlights: • Hot air injection in dual fired reactor reduces the tar content to less than 100 mg Nm −3 . • In clean gas the tar content is 35 mg Nm −3 and the dust content is nil. • The specific gasification rate is 2.8 Nm 3 kg −1 of fuel wood and cold gas efficiency is 89.7%. • CV of the gas: 5.3 MJ Nm −3 , SFC: 1.1 kg kWh −1 and wood to power efficiency: 21%. • Cold gas efficiency is improved by optimizing the reactor's design and recycling the waste heat from hot gas

Development of a modified equilibrium model for biomass pilot-scale fluidized bed gasifier performance predictions

International Nuclear Information System (INIS)

Rodriguez-Alejandro, David A.; Nam, Hyungseok; Maglinao, Amado L.; Capareda, Sergio C.; Aguilera-Alvarado, Alberto F.

2016-01-01

The objective of this work is to develop a thermodynamic model considering non-stoichiometric restrictions. The model validation was done from experimental works using a bench-scale fluidized bed gasifier with wood chips, dairy manure, and sorghum. The model was used for a further parametric study to predict the performance of a pilot-scale fluidized biomass gasifier. The Gibbs free energy minimization was applied to the modified equilibrium model considering a heat loss to the surroundings, carbon efficiency, and two non-equilibrium factors based on empirical correlations of ER and gasification temperature. The model was in a good agreement with RMS <4 for the produced gas. The parametric study ranges were 0.01 < ER < 0.99 and 500 °C < T < 900 °C to predict syngas concentrations and its LHV (lower heating value) for the optimization. Higher aromatics in tar were contained in WC gasification compared to manure gasification. A wood gasification tar simulation was produced to predict the amount of tars at specific conditions. The operating conditions for the highest quality syngas were reconciled experimentally with three biomass wastes using a fluidized bed gasifier. The thermodynamic model was used to predict the gasification performance at conditions beyond the actual operation. - Highlights: • Syngas from experimental gasification was used to create a non-equilibrium model. • Different types of biomass (HTS, DM, and WC) were used for gasification modelling. • Different tar compositions were identified with a simulation of tar yields. • The optimum operating conditions were found through the developed model.

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.

A combined system comprising a biomass gasifier and a Stirling engine. Design and optimisation for continuous operation; Eine Anlagenkombination aus Biomassevergaser und Stirlingmotor. Anlagendesign und Auslegung fuer den Dauerbetrieb

Energy Technology Data Exchange (ETDEWEB)

Huelscher, Manfred [Qalovis Farmer Automatic Energy GmbH, Laer (Germany)

2010-07-01

Conventional wood gasifiers consist of a gasifier, gas filter, and internal combustion engine. The contribution presents a novel system comprising a gasifier, burner, and Stirling engine. To enhance the electric efficiency, the burner is operated with air preheated via reculperation. The Stirling characteristic is known, and the gasification/combustion system can be calculated and designed on the basis of the Stirling data. The dust problem of the Stirling heat exchanger is solved by an automatic filter system, so that low-maintenance long-term operation becomes possible.

Effectiveness factors for a commercial steam reforming (Ni) catalyst and for a calcined dolomite used downstream biomass gasifiers

Energy Technology Data Exchange (ETDEWEB)

Corella, J; Narvaez, I; Orio, A [Madrid Univ. (Spain). Dept. of Chem. Eng.

1997-12-31

A commercial steam reforming catalyst from BASF, the G1-25 S one, and a calcined dolomite, Norte-1, from Cantabria-Spain, have been used, once crushed and sieved to different particle fractions between 1.0 and 4.0 mm. The materials have been tested downstream small pilot biomass gasifiers, bubbling fluidized bed type, gasifying with air and with steam. The Thiele modulus and the effectiveness factor have been calculated at temperatures of 750-850 deg C. It is experimentally shown that diffusion control plays an important part when particle size is larger than ca. 0.5 mm. This has to be taken into account when comparing the quality of the solids for tar elimination. (author) (5 refs.)

Effectiveness factors for a commercial steam reforming (Ni) catalyst and for a calcined dolomite used downstream biomass gasifiers

Energy Technology Data Exchange (ETDEWEB)

Corella, J.; Narvaez, I.; Orio, A. [Madrid Univ. (Spain). Dept. of Chem. Eng.

1996-12-31

A commercial steam reforming catalyst from BASF, the G1-25 S one, and a calcined dolomite, Norte-1, from Cantabria-Spain, have been used, once crushed and sieved to different particle fractions between 1.0 and 4.0 mm. The materials have been tested downstream small pilot biomass gasifiers, bubbling fluidized bed type, gasifying with air and with steam. The Thiele modulus and the effectiveness factor have been calculated at temperatures of 750-850 deg C. It is experimentally shown that diffusion control plays an important part when particle size is larger than ca. 0.5 mm. This has to be taken into account when comparing the quality of the solids for tar elimination. (author) (5 refs.)

Optimal operation for 3 control parameters of Texaco coal-water slurry gasifier with MO-3LM-CDE algorithms

Energy Technology Data Exchange (ETDEWEB)

Cao, Cuiwen; Zhang, Yakun; Gu, Xingsheng [Ministry of Education, East China Univ. of Science and Technology, Shanghai (China). Key Lab. of Advanced Control and Optimization for Chemical Processes

2013-07-01

Optimizing operation parameters for Texaco coal-water slurry gasifier with the consideration of multiple objectives is a complicated nonlinear constrained problem concerning 3 BP neural networks. In this paper, multi-objective 3-layer mixed cultural differential evolution (MO-3LM-CDE) algorithms which comprise of 4 multi-objective strategies and a 3LM-CDE algorithm are firstly presented. Then they are tested in 6 benchmark functions. Finally, the MO-3LM-CDE algorithms are applied to optimize 3 control parameters of the Texaco coal-water slurry gasifier in methanol production of a real-world chemical plant. The simulation results show that multi-objective optimal results are better than the respective single-objective optimal operations.

Gasified rice hull biochar affects nutrition and growth of five horticulture crops in container culture

Science.gov (United States)

Phosphate fertilizers used in the production of greenhouse crops can be problematic if released into the environment. Furthermore, the price of phosphate is increasing as demand increases and world supplies decrease. The objective of this research was to determine if gasified rice hull biochar (GR...

The use of oxygen-enriched air for biomass gasification: initial scoping study

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-07-01

The article reports an initial scoping study which is aimed at assessing the potential impact of using non-cryogenic oxygen, or oxygen-enriched air, for biomass gasification with respect to cost, design and operation of stationary biomass-fuelled generators in the range 5 to 15 MW(e). The study is expected to lead to identification of options worthy of more detailed study. The format of the scoping study is as follows: (i) using data on performance and cost from the manufacturers, minimum cost-saving potential is assessed; (ii) the performance and component costs of various gasifier types and engine types are reviewed to identify possible savings in monetary cost; (iii) an assessment of the likely impact of low-cost fuels is made and (iv) areas for detailed investigation are highlighted.

Wind-blown sandstones cemented by sulfate and clay minerals in Gale Crater, Mars

OpenAIRE

Milliken, R. E.; Ewing, Ryan C.; Fischer, W. W.; Hurowitz, J.

2014-01-01

Gale Crater contains Mount Sharp, a ~5km thick stratigraphic record of Mars’ early environmental history. The strata comprising Mount Sharp are believed to be sedimentary in origin, but the specific depositional environments recorded by the rocks remain speculative. We present orbital evidence for the occurrence of eolian sandstones within Gale Crater and the lower reaches of Mount Sharp, including preservation of wind-blown sand dune topography in sedimentary strata—a phenomenon ...

PLA and single component silicone rubber blends for sub-zero temperature blown film packaging applications

Science.gov (United States)

Meekum, Utai; Khiansanoi, Apichart

2018-06-01

The poly(lactic acid) (PLA) blend with single component silicone rubber in the presence of reactive amino silane coupling agent and polyester polyols plasticizer were studied. The manufacturing of film packaging for sub-zero temperature applications from the PLA blend was the main objective. The mechanical properties, especially the impact strengths, of PLA/silicone blends were significantly depended on the silicone loading. The outstanding impact strengths, tested at sub-zero temperature, of the blend having silicone content of 8.0 phr was achieved. It was chosen as the best candidate for the processability improvement. Adding the talc filler into the PLA/silicone blend to enhance the rheological properties was investigated. The ductility of the talc filled blends were decreased with increasing the filler contents. However, the shear viscosity of the blend was raised with talc loading. The blend loaded with 40 phr of talc filler was justified as the optimal formula for the blown film process testing and it was successfully performed with a few difficulties. The obtained blown film showed relative good flexibility in comparison with LDPE but it has low transparency.

Mechanical behavior and essential work of fracture of starch-based blown films

Science.gov (United States)

Nottez, M.; Chaki, S.; Soulestin, J.; Lacrampe, M. F.; Krawczak, P.

2015-05-01

A fracture mechanics approach (Essential Work of Fracture, EWF) was applied to assess the toughness of novel partly starch-grafted polyolefin blown films, compared to that of a neat polyethylene reference. Tests were performed on double-end notched samples. The digital image correlation method was used to monitor the deformation field around the notch. Regular tensile and tear tests were also carried out. The specific essential work of fracture is a characteristic which is much more sensitive to materials structural modifications than the tensile or tear properties.

Combustion performance of cellulosic biomass in a gasifier-based cookstove

Science.gov (United States)

Sulaiman, Shaharin A.; Romli, Raffisyazana

2012-06-01

Depletion in fossil fuel and increase in the world population may change the trend in future kitchens in households. Cooking with LPG fuel may one day become impossible and households would have to consider alternatives such as electric stoves. One other solution to this problem is through the use of biomass cook stoves. However, traditional cook stoves, predominantly used in the households, are not efficient and its utilizations for domestic cooking have been a major contributor to the ill effects related in respiratory and other health problem. Improved cook stoves programs implemented in the developing world attempt to address these problems. Biomass gasification appears to have significant potential in Asia for domestic cooking applications. Gasifier-based cook stoves are fuel efficient in comparison to traditional cook stove. The objective of this paper is to study the performance of various type of cellulosic biomass in a gasifier-based cook stove. The biomass considered in this study are oil palm fronds, dried leaves, wood sticks, coconut shells, bagasse, charcoal, and saw dust. The samples are analyzed in order to study their chemical properties. The thermochemical properties of the biomass were characterized. The performance of the each of the samples is studied by observing the time taken to boil water. It is found that oil palm fronds are the best type of biomass for the gasifer cook stove. It is also concluded that the higher the carbon content and the calorific value in a biomass, the lesser the time taken to boil the water.

Spatial variation in wind-blown sediment transport in geomorphic units in northern Burkina Faso using geostatistical mapping

NARCIS (Netherlands)

Visser, S.M.; Sterk, G.; Snepvangers, J.J.J.C.

2004-01-01

Due to rapid population growth, farmers in northern Burkina Faso have started to cultivate areas less suitable for agricultural production. In fields, situated at various geomorphologic settings, erodibility is highly variable resulting in variable wind-blown sediment fluxes. Furthermore, at a field

High melt strength, tear resistant blown film based on poly(lactic acid)

Science.gov (United States)

Edmonds, Neil R.; Plimmer, Peter N.; Tanner, Chris

2015-05-01

A major problem associated with the commercial manufacture of thin films from PLA is inferior processing characteristics on blown film lines compared to low density polyethylene. PLA has poor melt strength (leading to bubble instability) and develops a permanent crease in the flattened film as it exits the tower of the film line. In addition, the thin film product has poor tear strength and an unacceptable `noise' level when converted into flexible packaging. Furthermore, fabricated articles based on PLA are known to show an unattractive tendency toward dimensional instability. This behaviour is associated with `cold crystallization', a phenomenon which also causes exudation of any plasticizer added for improving flexibility. Blow moulded articles based on PLA also exhibit dimensional sensitivity above 60°C. All of these issues have been overcome by the technology described in this paper. This has been accomplished without loss of the valuable compostability characteristic of PLA; this was confirmed by evaluation of film in a commercial composting operation. These results have been achieved through novel reactive compounding technology which: (a) Creates a PLA-rich structure containing long chain crosslinks, (b) generates a low glass transition temperature phase covalently bonded to the PLA structure, and (c) provides a material which performs like LDPE in a blown film manufacturing operation. The technology developed is covered by NZ Patent 580231 (3). The patent is held by UniServices Ltd, The University of Auckland, New Zealand.

CHP from Updraft Gasifier and Stirling Engine

DEFF Research Database (Denmark)

Jensen, N.; Werling, J.; Carlsen, Henrik

2002-01-01

The combination of thermal gasification with a Stirling engine is an interesting concept for use in small combined heat and power plants based on biomass. By combining the two technologies a synergism can potentially be achieved. Technical problems, e.g. gas cleaning and fouling of the Stirling...... engine heat exchanger, can be eliminated and the overall electric efficiency of the system can be improved. At the Technical University of Denmark a Stirling engine fueled by gasification gas has been developed. In this engine the combustion system and the geometry of the hot heat exchanger...... of the Stirling engine has been adapted to the use of a gas with a low specific energy content and a high content of tar and particles. In the spring of 2001 a demonstration plant has been built in the western part of Denmark where this Stirling engine is combined with an updraft gasifier. A mathematical...

Thermodynamic modelling of an onsite methanation reactor for upgrading producer gas from commercial small scale biomass gasifiers.

Science.gov (United States)

Vakalis, S; Malamis, D; Moustakas, K

2018-06-15

Small scale biomass gasifiers have the advantage of having higher electrical efficiency in comparison to other conventional small scale energy systems. Nonetheless, a major drawback of small scale biomass gasifiers is the relatively poor quality of the producer gas. In addition, several EU Member States are seeking ways to store the excess energy that is produced from renewables like wind power and hydropower. A recent development is the storage of energy by electrolysis of water and the production of hydrogen in a process that is commonly known as "power-to-gas". The present manuscript proposes an onsite secondary reactor for upgrading producer gas by mixing it with hydrogen in order to initiate methanation reactions. A thermodynamic model has been developed for assessing the potential of the proposed methanation process. The model utilized input parameters from a representative small scale biomass gasifier and molar ratios of hydrogen from 1:0 to 1:4.1. The Villar-Cruise-Smith algorithm was used for minimizing the Gibbs free energy. The model returned the molar fractions of the permanent gases, the heating values and the Wobbe Index. For mixtures of hydrogen and producer gas on a 1:0.9 ratio the increase of the heating value is maximized with an increase of 78%. For ratios higher than 1:3, the Wobbe index increases significantly and surpasses the value of 30 MJ/Nm 3 . Copyright © 2017 Elsevier Ltd. All rights reserved.

Techno-economic assessment of a solar PV, fuel cell, and biomass gasifier hybrid energy system

Directory of Open Access Journals (Sweden)

Anand Singh

2016-11-01

Full Text Available The interest of power is expanding step by step all through the world. Because of constrained measure of fossil fuel, it is vital to outline some new non-renewable energy frameworks that can diminish the reliance on ordinary energy asset. A hybrid off-grid renewable energy framework might be utilized to reduction reliance on the traditional energy assets. Advancement of crossover framework is a procedure to choose the best mix of part and there cost that can give shabby, solid and successful option energy resource. In this paper sun oriented photovoltaic, fuel cell, biomass gasifier generator set, battery backup and power conditioning unit have been simulated and optimized for educational institute, energy centre, Maulana Azad National Institute of Technology, Bhopal in the Indian state of Madhya Pradesh. The area of the study range on the guide situated of 23°12′N latitude and 77°24′E longitude. In this framework, the essential wellspring of power is sun based solar photovoltaic system and biomass gasifier generator set while fuel cell and batteries are utilized as reinforcement supply. HOMER simulator has been utilized to recreate off the grid and it checks the specialized and financial criteria of this hybrid energy system. The execution of every segment of this framework is dissected lastly delicate examination has been performing to enhance the mixture framework at various conditions. In view of the recreation result, it is found that the cost of energy (COE of a biomass gasifier generator set, solar PV and fuel cell crossover energy system has been found to be 15.064 Rs/kWh and complete net present cost Rs.51,89003. The abundance power in the proposed framework is observed to be 36 kWh/year with zero rates unmet electrical burden.

Simulation of petcoke gasification in slagging moving bed reactors

Energy Technology Data Exchange (ETDEWEB)

Nagpal, Soumitro; Sarkar, T.K.; Sen, P.K. [Research and Development Center, Engineers India Limited, Gurgaon 122001 (India)

2005-03-25

A mathematical model for simulation of moving bed petcoke gasifiers was developed. The model introduces a new feed characterization method, gas-phase resistance and volatilization models. The model is validated using reported data for a slagging gasifier. Effect of feed oxygen-to-coke and steam-to-coke ratios and feed coke rates on gasification performance was examined. Slagging zone moving bed gasifier operation with very high petcoke fluxes of over 4000 kg/m{sup 2}/h was possible with high petcoke conversion. Peak gas temperatures exceeded 1500 {sup o}C. Fluxes higher than 5000 kg/m{sup 2}/h are limited by an approach to fluidization of small particles in the combustion zone. The moving bed gasifier performance was found superior to performance of an entrained flow gasifier (EFG) with respect to energy efficiency and oxygen consumption.

The study of solid circulation rate in a compartmented fluidized bed gasifier (CFBG)

Science.gov (United States)

Wee, S. K.; Pok, Y. W.; Law, M. C.; Lee, V. C. C.

2016-06-01

Biomass waste has been abundantly available in Malaysia since the booming of palm oil industry. In order to tackle this issue, gasification is seen a promising technology to convert waste into energy. In view of the heat requirement for endothermic gasification reaction as well as the complex design and operation of multiple fluidized beds, compartmented fluidized bed gasifier (CFBG) with the combustor and the gasifier as separate compartments is proposed. As such, solid circulation rate (SCR) is one of the essential parameters for steady gasification and combustion to be realized in their respective compartments. Experimental and numerical studies (CFD) on the effect of static bed height, main bed aeration, riser aeration and v-valve aeration on SCR have been conducted in a cold- flow CFBG model with only river sand as the fluidizing medium. At lower operating range, the numerical simulations under-predict the SCR as compared to that of the experimental results. Also, it predicts slightly different trends over the range. On the other hand, at higher operating range, the numerical simulations are able to capture those trends as observed in the experimental results at the lower operating range. Overall, the numerical results compare reasonably well with that of the experimental works.

Successful completion of the development and testing of a coal to fuel cell grade hydrogen technology package for New Zealand

Energy Technology Data Exchange (ETDEWEB)

Anthony H. Clemens; Tana P. Levi; Robert S. Whitney; Alister I. Gardiner

2009-07-01

A technology package for the production, from New Zealand lignite, of high purity hydrogen suitable for use in an alkaline fuel cell has been successfully developed and tested. The technology involves the integration of an air-blown 1 tonne per day fluidised bed gasifier with a range of downstream syngas clean-up components leading to the fuel cell. The development of the technology package was built on earlier work that showed New Zealand lignites to be among the most reactive in the world and well suited to fluidised bed gasification. The reason for their high reactivity was shown to be due to the presence of ion-exchanged calcium within the lignite structure. The clean-up line is comprised of some commonly used 'off the shelf' technologies. These include a cyclone and Venturi scrubber for particulate and condensables capture respectively and a high temperature water gas shift reactor. It also contains a less commonly used counterflow caustic wash packed column for H{sub 2}S removal and an experimental membrane for final hydrogen separation. The clean-up line is constructed so that it may be used to testbed other new syngas clean-up technologies. The paper describes the new technology package, considers several issues that arose during its development and how these were addressed. It also considers the future development of the technology including co-gasification with biomass and conversion to an oxygen blown unit for synfuel production. 20 refs., 4 figs., 1 tab.

Gasification of biomass and coal in a pressurised fluidised bed gasifier

Energy Technology Data Exchange (ETDEWEB)

Andries, J; Jong, W de; Hein, K R.G. [Technische Univ. Delft (Netherlands)

1998-09-01

During a 3 year (1996-1998) multinational JOULE project, partly funded by the EU, experimental and theoretical research is being done on co-gasification of biomass (pelletised straw and Miscanthus) and coal in a pressurised fluidised bed reactor. The influence of feedstock and operating conditions on gasification characteristics has been studied using a 1.5 MW{sub th} gasifier, which has been operated at a pressure of 5 bar and temperatures up to 900 C. The project and the test rig are described and results obtained in the first part of the project are presented and analysed. (orig.)

Thermal valorization of post-consumer film waste in a bubbling bed gasifier

International Nuclear Information System (INIS)

Martínez-Lera, S.; Torrico, J.; Pallarés, J.; Gil, A.

2013-01-01

Highlights: • Film waste from packaging is a common waste, a fraction of which is not recyclable. • Gasification can make use of the high energy value of the non-recyclable fraction. • This waste and two reference polymers were gasified in a bubbling bed reactor. • This experimental research proves technical feasibility of the process. • It also analyzes impact of composition and ER on the performance of the plant. - Abstract: The use of plastic bags and film packaging is very frequent in manifold sectors and film waste is usually present in different sources of municipal and industrial wastes. A significant part of it is not suitable for mechanical recycling but could be safely transformed into a valuable gas by means of thermal valorization. In this research, the gasification of film wastes has been experimentally investigated through experiments in a fluidized bed reactor of two reference polymers, polyethylene and polypropylene, and actual post-consumer film waste. After a complete experimental characterization of the three materials, several gasification experiments have been performed to analyze the influence of the fuel and of equivalence ratio on gas production and composition, on tar generation and on efficiency. The experiments prove that film waste and analogue polymer derived wastes can be successfully gasified in a fluidized bed reactor, yielding a gas with a higher heating value in a range from 3.6 to 5.6 MJ/m 3 and cold gas efficiencies up to 60%

Sustainable model for financial viability of decentralized biomass gasifier based power projects

International Nuclear Information System (INIS)

Palit, Debajit; Malhotra, Ramit; Kumar, Atul

2011-01-01

This paper made a modest attempt for designing a sustainable model for financial viability of biomass gasifier power projects for enhancing electricity access in India and other developing countries. For long term sustainability of distributed generation projects in remote rural areas, viability from both project implementing agency (PIA) and the end-users need to be ensured. The minimum required prices of electricity from both PIA and end-user perspective have been estimated. While for PIA the cost recovery is the key for viability, the affordability to pay the electricity cost is crucial for the end users. Analysis carried out in this paper on the basis of data obtained from operational projects implemented in India reveal that it is essential to operate the system at a higher capacity utilization factor. While this can be achieved though creating convergence with locally relevant economic activity, it is also observed that micro-enterprises cannot pay beyond a certain price of electricity to keep it sustainable. This paper sets forth a case for developing a regulatory mechanism to extend the tariff fixation for the projects and providing cross-subsidies to ensure long term sustainability of off-grid project. - Highlights: → We design sustainable financial model for viability of biomass gasifier projects. → Analysis based on field data obtained from operational projects in India. Estimated electricity pricing from both implementing agency and end-users perspective. → A regulatory mechanism for tariff fixation and cross subsidization is recommended.

Measuring Density Profiles of Electrons and Heavy Particles in a Stable Axially Blown Arc

Science.gov (United States)

Carstensen, J.; Stoller, P.; Galletti, B.; Doiron, C. B.; Sokolov, A.

2017-08-01

Two-color spatial carrier wave interferometry employing pulsed 532- and 671-nm lasers is used to measure the electron-density and heavy-particle-density profiles in the stagnation point of a stable, axially blown arc in argon for currents of 50 to 200 A and stagnation point pressures of 0.2 to 16 bar. This technique takes advantage of the fact that the free-electron contribution to the refractive index depends strongly on the wavelength, while that of the heavy particles does not. The high spatial resolution achieved allows the hot core of the arc to be readily distinguished from the surrounding boundary layer. A custom-built test device is used to ensure flow conditions that lead to a stable, axisymmetric arc; this permits the reconstruction of the density and temperature profiles using a single projection (interferometric image) of the refractive-index distribution through the arc (at two wavelengths). The arc radius determined from the heavy-particle density decreases with increasing stagnation pressure and increases with the current. These measurements are in good agreement with a simple axially blown arc model taking into account Ohmic heating, radiation losses, and enthalpy flow for core temperatures of approximately 16 500 K. The measured electron density at the center of the arc agrees well with a prediction based on local thermodynamic equilibrium.

Influence of operating conditions on the air gasification of dry refinery sludge in updraft gasifier

International Nuclear Information System (INIS)

Ahmed, R; Sinnathambi, C M

2013-01-01

In the present work, details of the equilibrium modeling of dry refinery sludge (DRS) are presented using ASPEN PLUS Simulator in updraft gasifier. Due to lack of available information in the open journal on refinery sludge gasification using updraft gasifier, an evaluate for its optimum conditions on gasification is presented in this paper. For this purpose a Taguchi Orthogonal array design, statistical software is applied to find optimum conditions for DRS gasification. The goal is to identify the most significant process variable in DRS gasification conditions. The process variables include; oxidation zone temperature, equivalent ratio, operating pressure will be simulated and examined. Attention was focused on the effect of optimum operating conditions on the gas composition of H 2 and CO (desirable) and CO 2 (undesirable) in terms of mass fraction. From our results and finding it can be concluded that the syngas (H 2 and CO) yield in term of mass fraction favors high oxidation zone temperature and at atmospheric pressure while CO 2 acid gas favor at a high level of equivalent ratio as well as air flow rate favoring towards complete combustion.

Agglomeration and reaction characteristics of various coal chars in fluidized-bed coal gasifier; Ryudoso sekitan gas ka ronai deno sekitan no gyoshu tokusei to hanno tokusei

Energy Technology Data Exchange (ETDEWEB)

Uemiya, S.; Aoki, K.; Mori, S.; Kojima, T. [Seikei University, Tokyo (Japan). Faculty of Engineering

1996-10-28

With relation to the coals delivered as common samples in the coal fundamental technology development project, an experimental study was conducted on agglomeration characteristics and reaction characteristics in the fluidized-bed coal gasifier. For the experiment, used was a fluidized bed gasifier inserted with a cone-shape dispersion plate with a nozzle in the center. After raising the temperature of the gasifier up to 773K, gasification was conducted sending to the gasifier air from the nozzle and steam from the dispersion plate. The mean particle diameter and gas concentration of chars were measured till the temperature reaches 1373K. As a result of the experiment, it was confirmed that the carbon conversion ratio increases with a decrease in coalification degree of the coal. Moreover, influence of the coal kind was markedly observed at the grid zone of the lower part of the bed, and it was clarified that the lower carbon content ratio the coal kind has, the faster the speed of CO formation and water gasification get. The agglomeration temperature of charcoal which is a product of the condensate is lower by as many as several hundred K than the point of softening, and it was considered to be necessary to study the relation with the temperature distribution in the bed. 3 refs., 3 figs., 1 tab.

A new model for coal gasification on pressurized bubbling fluidized bed gasifiers

International Nuclear Information System (INIS)

Sánchez, Cristian; Arenas, Erika; Chejne, Farid; Londoño, Carlos A.; Cisneros, Sebastian; Quintana, Juan C.

2016-01-01

Highlights: • A new model was proposed for the simulation of fluidized bed reactors. • The model was validated against experimental data found in the literature. • The model was compared and found to be superior to other models reported in the literature. • Effects of pressure, temperature, steam/coal and air/coal ratios over gas composition were studied. - Abstract: Many industries have taken interest in the use of coal gasification for the production of chemicals and fuels. This gasification can be carried out inside a fluidized bed reactor. This non-ideal reactor is difficult to predict due to the complex physical phenomena and the different chemical changes that the feedstock undergoes. The lack of a good model to simulate the reactor’s behavior produces less efficient processes and plant designs. Various approaches to the proper simulation of such reactor have been proposed. In this paper, a new model is developed for the simulation of a pressurized bubbling fluidized bed (PBFB) gasifier that rigorously models the physical phenomena and the chemical changes of the feedstock inside the reactor. In the model, the reactor is divided into three sections; devolatilization, volatile reactions and combustion-gasification. The simulation is validated against experimental data reported in the literature and compared with other models proposed by different authors; once the model is validated, the dependence of the syngas composition on operational pressure, temperature, steam/coal and air/coal ratios are studied. The results of this article show how this model satisfactorily predicts the performance of PBFB gasifiers.

Numerical simulation of a 200 kW down draft gasifier using acai seed (Euterpe oleracea mart.) as fuel

Energy Technology Data Exchange (ETDEWEB)

Itai, Y.; Rocha, H.M.Z. [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Faculdade de Engenharia Mecanica]. E-mails: yuuitai@ufpa.br; hendrick@ufpa.br; Brasil, A.M. [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Faculdade de Engenharia Sanitaria e Ambiental]. E-mail: ambrasil@ufpa.br; Malico, I. [Universidade de Evora (Portugal)]. E-mail: imbm@uevora.pt

2008-07-01

In this work a thermochemical equilibrium model for downdraft gasifiers has been proposed. The model was compared to the model developed in Gordon and McBride (1994). The properties such as efficiency of cold gas, LHV and temperature of an Amazonian biomass Euterpe olearacea Mart. was simulated. The numerical simulations aimed the maximization of H{sub 2} and CH{sub 4} in a gasification process. The model simulated numerically the influence of the gasifying relative fuel/air ratio and the biomass moisture content on the syngas composition. Two values of moisture content 33% and 37.5% were suggested for the gasification of acai seed for the maximization of the H{sub 2} and CH{sub 4} concentrations in a range of the equivalence ratio, {phi}, between 2.3 and 4. The results also showed that to achieve the maximization of CH{sub 4} with {phi} = 4 the reaction temperature drops in average of 35.44%. (author)

Advancement of High Temperature Black Liquor Gasification Technology

Energy Technology Data Exchange (ETDEWEB)

Craig Brown; Ingvar Landalv; Ragnar Stare; Jerry Yuan; Nikolai DeMartini; Nasser Ashgriz

2008-03-31

Weyerhaeuser operates the world's only commercial high-temperature black liquor gasifier at its pulp mill in New Bern, NC. The unit was started-up in December 1996 and currently processes about 15% of the mill's black liquor. Weyerhaeuser, Chemrec AB (the gasifier technology developer), and the U.S. Department of Energy recognized that the long-term, continuous operation of the New Bern gasifier offered a unique opportunity to advance the state of high temperature black liquor gasification toward the commercial-scale pressurized O2-blown gasification technology needed as a foundation for the Forest Products Bio-Refinery of the future. Weyerhaeuser along with its subcontracting partners submitted a proposal in response to the 2004 joint USDOE and USDA solicitation - 'Biomass Research and Development Initiative'. The Weyerhaeuser project 'Advancement of High Temperature Black Liquor Gasification' was awarded USDOE Cooperative Agreement DE-FC26-04NT42259 in November 2004. The overall goal of the DOE sponsored project was to utilize the Chemrec{trademark} black liquor gasification facility at New Bern as a test bed for advancing the development status of molten phase black liquor gasification. In particular, project tasks were directed at improvements to process performance and reliability. The effort featured the development and validation of advanced CFD modeling tools and the application of these tools to direct burner technology modifications. The project also focused on gaining a fundamental understanding and developing practical solutions to address condensate and green liquor scaling issues, and process integration issues related to gasifier dregs and product gas scrubbing. The Project was conducted in two phases with a review point between the phases. Weyerhaeuser pulled together a team of collaborators to undertake these tasks. Chemrec AB, the technology supplier, was intimately involved in most tasks, and focused primarily on the

Power Systems Development Facility Gasification Test Campaign TC24

Energy Technology Data Exchange (ETDEWEB)

Southern Company Services

2008-03-30

In support of technology development to utilize coal for efficient, affordable, and environmentally clean power generation, the Power Systems Development Facility (PSDF), located in Wilsonville, Alabama, routinely demonstrates gasification technologies using various types of coals. The PSDF is an engineering scale demonstration of key features of advanced coal-fired power systems, including a KBR Transport Gasifier, a hot gas particulate control device, advanced syngas cleanup systems, and high-pressure solids handling systems. This report summarizes the results of TC24, the first test campaign using a bituminous coal as the feedstock in the modified Transport Gasifier configuration. TC24 was conducted from February 16, 2008, through March 19, 2008. The PSDF gasification process operated for about 230 hours in air-blown gasification mode with about 225 tons of Utah bituminous coal feed. Operational challenges in gasifier operation were related to particle agglomeration, a large percentage of oversize coal particles, low overall gasifier solids collection efficiency, and refractory degradation in the gasifier solids collection unit. The carbon conversion and syngas heating values varied widely, with low values obtained during periods of low gasifier operating temperature. Despite the operating difficulties, several periods of steady state operation were achieved, which provided useful data for future testing. TC24 operation afforded the opportunity for testing of various types of technologies, including dry coal feeding with a developmental feeder, the Pressure Decoupled Advanced Coal (PDAC) feeder; evaluating a new hot gas filter element media configuration; and enhancing syngas cleanup with water-gas shift catalysts. During TC24, the PSDF site was also made available for testing of the National Energy Technology Laboratory's fuel cell module and Media Process Technology's hydrogen selective membrane.

Environmental performance of gasified willow from different lands including land-use changes

DEFF Research Database (Denmark)

Saez de Bikuna Salinas, Koldo; Hauschild, Michael Zwicky; Pilegaard, Kim

2017-01-01

A life-cycle assessment (LCA) of a low-input, short rotation coppice (SRC) willow grown on different Danish lands was performed. Woodchips are gasified, producer gas is used for co-generation of heat and power (CHP) and the ash-char output is applied as soil amendment in the field. A hybrid model...... for abandoned farmland, as a relative C stock loss compared to natural regeneration. ILUC results show that area related GHG emissions are dominant (93% of iLUCfood and 80% of iLUCfeed), transformation being more important (82% of iLUCfood) than occupation (11%) impacts. LCA results show that CHP from willow...

Comprehensive report to Congress, Clean Coal Technology program: Pinon Pine IGCC Power Project

International Nuclear Information System (INIS)

1992-06-01

The objective of the proposed project is to demonstrate an advanced IGCC system based upon the air-blown, fluidized-bed KRW gasifier with in-bed desulfurization using limestone sorbent and an external fixed- bed zinc ferrite sulfur removal system. Sierra Pacific Power Company (SPPC) requested financial assistance from DOE for the design, construction, and operation of a nominal 800 ton-per-day (86-Megawatt gross), air blown integrated gasification combined-cycle (IGCC) demonstration plant. The project, named the Pinon Pine IGCC Power Project, is to be located at SPPC's Tracy Station, a power generation facility located on a rural 400-acre plot about 17 miles east of Reno. The demonstration plant will produce electrical power for the utility grid. The project, including the demonstration phase, will last 96 months at a total cost of $269,993,100. DOE's share of the project cost will be 50 percent, or $134,996,550

Introduction of an energy efficiency tool for small scale biomass gasifiers – A thermodynamic approach

International Nuclear Information System (INIS)

Vakalis, S.; Patuzzi, F.; Baratieri, M.

2017-01-01

Highlights: • Analysis of plants for electricity, heat and materials production. • Thermodynamic analysis by using exergy, entransy and statistical entropy. • Extrapolation of a single efficiency index by combining the thermodynamic parameters. • Application of methodology for two monitored small scale gasifiers. - Abstract: Modern gasification plants, should be treated as poly-generation facilities because, alongside the production of electricity and heat, valuable or waste materials streams are generated. Thus, integrated methods should be introduced in order to account for the full range and the nature of the products. Application of conventional hybrid indicators that convert the output into monetary units or CO_2 equivalents are a source of bias because of the inconsistency of the conversion factors and unreliability of the available data. Therefore, this study introduces a novel thermodynamic-based method for assessing gasification plants performance by means of exergy, entransy and statistical entropy. A monitoring campaign has been implemented on two small scale gasifiers and the results have been applied on the proposed method. The energy plants are compared in respect to their individual thermodynamic parameters for energy production and materials distribution. In addition, the method returns one single value which is a resultant of all the investigated parameters and is a characteristic value of the overall performance of an energy plant.

Application of Scaling-Law and CFD Modeling to Hydrodynamics of Circulating Biomass Fluidized Bed Gasifier

Directory of Open Access Journals (Sweden)

Mazda Biglari

2016-06-01

Full Text Available Two modeling approaches, the scaling-law and CFD (Computational Fluid Dynamics approaches, are presented in this paper. To save on experimental cost of the pilot plant, the scaling-law approach as a low-computational-cost method was adopted and a small scale column operating under ambient temperature and pressure was built. A series of laboratory tests and computer simulations were carried out to evaluate the hydrodynamic characteristics of a pilot fluidized-bed biomass gasifier. In the small scale column solids were fluidized. The pressure and other hydrodynamic properties were monitored for the validation of the scaling-law application. In addition to the scaling-law modeling method, the CFD approach was presented to simulate the gas-particle system in the small column. 2D CFD models were developed to simulate the hydrodynamic regime. The simulation results were validated with the experimental data from the small column. It was proved that the CFD model was able to accurately predict the hydrodynamics of the small column. The outcomes of this research present both the scaling law with the lower computational cost and the CFD modeling as a more robust method to suit various needs for the design of fluidized-bed gasifiers.

Biomass gasification hot gas cleanup for power generation

Energy Technology Data Exchange (ETDEWEB)

Wiant, B.C.; Bachovchin, D.M. [Westinghouse Electric Corp., Orlando, FL (United States); Carty, R.H.; Onischak, M. [Institute of Gas Technology, Chicago, IL (United States); Horazak, D.A. [Gilbert/Commonwealth, Reading, PA (United States); Ruel, R.H. [The Pacific International Center for High Technology Research, Honolulu, HI (United States)

1993-12-31

In support of the US Department of Energy`s Biomass Power Program, a Westinghouse Electric led team consisting of the Institute of Gas Technology (IGT), Gilbert/Commonwealth (G/C), and the Pacific International Center for High Technology Research (PICHTR), is conducting a 30 month research and development program. The program will provide validation of hot gas cleanup technology with a pressurized fluidized bed, air-blown, biomass gasifier for operation of a gas turbine. This paper discusses the gasification and hot gas cleanup processes, scope of work and approach, and the program`s status.

Defluidization in fluidized bed gasifiers using high-alkali content fuels

DEFF Research Database (Denmark)

Narayan, Vikas; Jensen, Peter Arendt; Henriksen, Ulrik Birk

2016-01-01

samples,agglomeration could be attributed to viscous silicate melts formed from reaction of inorganic alkalineand alkali earth species with silica from the bed particles. A mathematical model that addresses the defluidization behavior of alkali-rich samples was developed based on the experiments performed...... and calcium, which may form viscous melts that adhere on the surface of the colliding bed particles and bind them to form agglomerates. In this paper, studies were made to understand the behavior of inorganic elements (mainly K, Si and Ca) on agglomeration and de-fluidization of alkali rich bed...... in the bench-scale fluidized bed reactor as well as on results from literature. The model was then used topredict the de-fluidization behavior of alkali-rich bed material in a large-scale LTCFB gasifier....

Effect of reverse Boudouard reaction catalyst on the performance of solid oxide carbon fuel cells integrated with a dry gasifier

International Nuclear Information System (INIS)

Kim, Sun-Kyung; Mehran, Muhammad Taqi; Mushtaq, Usman; Lim, Tak-Hyoung; Lee, Jong-Won; Lee, Seung-Bok; Park, Seok-Joo; Song, Rak-Hyun

2016-01-01

Highlights: • The addition of K_2CO_3 catalyst in carbon fuel improves the performance of SO-CFC. • Thermal and electrochemical analyses done to elucidate the catalytic enhancement. • Material characterization of SO-CFC performed after long-term degradation test. - Abstract: A solid oxide carbon fuel cell (SO-CFC) integrated with a dry gasifier was operated on activated carbon fuel and the effect of adding a reverse Boudouard gasification catalyst on the performance and long-term operation characteristics of the SO-CFC was investigated. The reactivity of the carbon fuels for the Boudouard gasification reaction was analyzed by a thermal analysis at various operating conditions. The SO-CFC was then operated on gasified fuel gas consisting of CO_2 and CO obtained from the integrated dry gasifier. The SO-CFC operated on activated carbon fuel with 5 wt.% K_2CO_3 achieved a maximum power density of 202, 262, and 271 mW/cm"2 at 750, 800, and 850 °C, respectively; the SO-CFC fueled with activated carbon fuel without a catalyst meanwhile yielded maximum power density of 168 mW/cm"2 at 850 °C. By using electrochemical impedance spectroscopy, the effect of adding the catalyst on the gasification products and subsequently on the performance of the SO-CFC was studied. A long-term degradation test was conducted by continuously operating the SO-CFC at 50 mA/cm"2 for 518 h at 750 °C. During the long-term degradation test, the average degradation rate of the SO-CFC was found to be 183 mV/kh. The post-mortem SEM and XRD analyses of the SO-CFC after the long-term test revealed the presence of carbon deposits and oxidation of Ni at the anode, causing a relatively higher degree of degradation in the SO-CFC integrated with the dry gasifier during the long-term operation. The addition of the K_2CO_3 based dry gasification catalyst significantly enhances the performance of the SO-CFC integrated with dry gasification, but during long-term operation, the degradation rate is found

Polystyrene foam products equation of state as a function of porosity and fill gas

International Nuclear Information System (INIS)

Mulford, Roberta N.; Swift, Damian C.

2009-01-01

An accurate EOS for polystyrene foam is necessary for analysis of numerous experiments in shock compression, inertial confinement fusion, and astrophysics. Plastic to gas ratios vary between various samples of foam, according to the density and cell-size of the foam. A matrix of compositions has been investigated, allowing prediction of foam response as a function of the plastic-to-air ratio. The EOS code CHEETAH allows participation of the air in the decomposition reaction of the foam. Differences between air-filled, Ar-blown, and CO 2 -blown foams are investigated, to estimate the importance of allowing air to react with products of polystyrene decomposition. O 2 -blown foams are included in some comparisons, to amplify any consequences of reaction with oxygen in air. He-blown foams are included in some comparisons, to provide an extremum of density. Product pressures are slightly higher for oxygen-containing fill gases than for non-oxygen-containing fill gases. Examination of product species indicates that CO 2 decomposes at high temperatures.

Blown films of PA6/MMT nanocomposites: structural characterization by SAXs

International Nuclear Information System (INIS)

Marini, J.; Beatrice, C.A.G.; Lucas, A.A.; Bretas, R.E.S.

2016-01-01

In this work the influence of the processing conditions (take up and blow up ratios, TUR and BUR, respectively) in the nano-periodicity and lamellae orientation of PA6 nanocomposites blown films with natural (MMT) and organically modified montmorillonite (oMMT) was studied by SAXS. Unexpectedly, a preferred orientation of the crystalline lamellae along the normal direction (ND) was observed for all analyzed films. Such behavior can be explained by the preservation of the initial lamellae orientation of the PA6 chains imposed by the spiral flow in the die, almost null elastic recovery and fast crystallization kinetics of PA6 at the processing conditions applied. The orientation of the nanoparticles (measured by TEM) showed to be directly dependent on the TUR and BUR. The presence of the reinforcing fillers and the different processing conditions showed no significant influence on the nanoperiodicity. (author)

Hydrogen production with short contact time. Catalytic partial oxidation of hydrocarbons and oxygenated compounds: Recent advances in pilot- and bench-scale testing and process design

Energy Technology Data Exchange (ETDEWEB)

Guarinoni, A.; Ponzo, R.; Basini, L. [ENI Refining and Marketing Div., San Donato Milanese (Italy)

2010-12-30

ENI R and D has been active for fifteen years in the development of Short Contact Time - Catalytic Partial Oxidation (SCT-CPO) technologies for producing Hydrogen/Synthesis Gas. From the beginning the experimental work addressed either at defining the fundamental principles or the technical and economical potential of the technology. Good experimental responses, technical solutions' simplicity and flexibility, favourable techno-economical evaluations promoted the progressive widening of the field of the investigations. From Natural Gas (NG) the range of ''processable'' Hydrocarbons extended to Liquefied Petroleum Gas (LPG) and Gasoils, including those characterised by high levels of unsaturated and sulphurated molecules and, lately, to other compounds with biological origin. The extensive work led to the definition of different technological solutions, grouped as follows: Technology 1: Air Blown SCT-CPO of Gaseous Hydrocarbons and/or Light Compounds with biological origin Technology 2: Enriched Air/Oxygen Blown SCT-CPO of Gaseous Hydrocarbons and/or Light Compounds with biological origin Technology 3: Enriched Air/Oxygen Blown SCT-CPO of Liquid Hydrocarbons and/or Compounds with biological origin Recently, the licence rights on a non-exclusive basis for the commercialisation of SCT-CPO based processes for H{sub 2}/Synthesis gas production from light hydrocarbons with production capacity lower than 5,000 Nm{sup 3}/h of H{sub 2} or 7,500 Nm3/h of syngas have been assigned to two external companies. In parallel, development of medium- and large-scale plant solutions is progressing within the ENI group framework. These last activities are addressed to the utilisation of SCT-CPO for matching the variable Hydrogen demand in several contexts of oil refining operation. This paper will report on the current status of SCT-CPO with a focus on experimental results obtained, either at pilot- and bench- scale level. (orig.)

Artificial neural network modelling approach for a biomass gasification process in fixed bed gasifiers

International Nuclear Information System (INIS)

Mikulandrić, Robert; Lončar, Dražen; Böhning, Dorith; Böhme, Rene; Beckmann, Michael

2014-01-01

Highlights: • 2 Different equilibrium models are developed and their performance is analysed. • Neural network prediction models for 2 different fixed bed gasifier types are developed. • The influence of different input parameters on neural network model performance is analysed. • Methodology for neural network model development for different gasifier types is described. • Neural network models are verified for various operating conditions based on measured data. - Abstract: The number of the small and middle-scale biomass gasification combined heat and power plants as well as syngas production plants has been significantly increased in the last decade mostly due to extensive incentives. However, existing issues regarding syngas quality, process efficiency, emissions and environmental standards are preventing biomass gasification technology to become more economically viable. To encounter these issues, special attention is given to the development of mathematical models which can be used for a process analysis or plant control purposes. The presented paper analyses possibilities of neural networks to predict process parameters with high speed and accuracy. After a related literature review and measurement data analysis, different modelling approaches for the process parameter prediction that can be used for an on-line process control were developed and their performance were analysed. Neural network models showed good capability to predict biomass gasification process parameters with reasonable accuracy and speed. Measurement data for the model development, verification and performance analysis were derived from biomass gasification plant operated by Technical University Dresden

To gasify or not to gasify torrefied wood? : Investigating the effect of torrefaction on oxygen steam blown circulating fluidized bed gasification of wood, focusing on permanent gas and tar composition, and environmental performance

NARCIS (Netherlands)

Tsalidis, G.A.

2018-01-01

Biomass is a sustainable biofuel as long as it does not compete with food and feed production. Gasification is a versatile technology that produces a gas which can be converted into various high value products. Torrefaction is a technology that converts biomass to a more coal alike product with

Assessment of the gasification characteristics of some agricultural and forest industry residues using a laboratory gasifier

Energy Technology Data Exchange (ETDEWEB)

Williams, R O; Goss, J R

1979-01-01

Gasification means here the reaction of solid fuels with air to yield a low calorific value gas, suitable as a fuel. The solid fuels considered are agricultural and forest industry residues. A laboratory-scale downdraft gasifier was used to study the gasification properties of certain biomass fuels. The grate is the most critical part of the gasifier. Two designs were tested: a rotating eccentric grate and a perforated steel basket. The latter was specifically designed for use with granular fuels such as mulled walnut shells. Batch tests were performed with different biomass fuels and at varying fuel consumption rates. The composition of the generated gas and the mass and heat balances were determined. Substantial closure errors are reported. These are considered to be the result of tars in the gas which were not accounted for. Yields varied from 75.5% in the case of walnut shells to 46% for rice hulls. With a biomass fuel consisting of a mixture of two sizes of walnut shells, yields in excess of 80% were recorded at high fuel consumption rates. Some practical aspects concerning the gasification of biomass fuels and problems associated with cotton gin trash, rice hulls, and wood residues are discussed.

Fixed-bed gasifier and cleanup system engineering summary report through Test Run No. 100

Energy Technology Data Exchange (ETDEWEB)

Pater, K. Jr.; Headley, L.; Kovach, J.; Stopek, D.

1984-06-01

The state-of-the-art of high-pressure, fixed-bed gasification has been advanced by the many refinements developed over the last 5 years. A novel full-flow gas cleanup system has been installed and tested to clean coal-derived gases. This report summarizes the results of tests conducted on the gasifier and cleanup system from its inception through 1982. Selected process summary data are presented along with results from complementary programs in the areas of environmental research, process simulation, analytical methods development, and component testing. 20 references, 32 figures, 42 tables.

Benefits of Allothermal Biomass Gasification for Co-Firing

Energy Technology Data Exchange (ETDEWEB)

Van der Meijden, C.M.; Van der Drift, A.; Vreugdenhil, B.J. [ECN Biomass and Energy Efficiency, Petten (Netherlands)

2012-04-15

Many countries have set obligations to reduce the CO2 emissions from coal fired boilers. Co-firing of biomass in existing coal fired power plants is an attractive solution to reduce CO2 emissions. Co-firing can be done by direct mixing of biomass with coal (direct co-firing) or by converting the biomass into a gas or liquid which is fired in a separate burner (indirect co-firing). Direct co-firing is a rather simple solution, but requires a high quality and expensive biomass fuel (e.g. wood pellets). Indirect co-firing requires an additional installation that converts the solid biomass into a gas or liquid, but has the advantage that it can handle a wide range of cheap biomass fuels (e.g. demolition wood) and most of the biomass ash components are separated from the gas before it enters the boiler. Separation of biomass ash can prevent fouling issues in the boiler. Indirect co-firing, using biomass gasification technology, is already common practice. In Geertruidenberg (the Netherlands) a 80 MWth Lurgi CFB gasifier produces gas from demolition wood which is co-fired in the Amer PC boiler. In Ruien (Belgium) a 50 MWth Foster Wheeler fluidized bed gasifier is in operation. The Energy research Centre of the Netherlands (ECN) developed a 'second generation' allothermal gasifier called the MILENA gasifier. This gasifier has some major advantages over conventional fluidized bed gasifiers. The heating value of the produced gas is approximately 2.5 times higher than of gas produced by conventional bubbling / circulating fluidized bed gasifiers. This results in smaller adaptations to the membrane wall of the boiler for the gas injection, thus lower costs. A major disadvantage of most fluidized bed gasifiers is the incomplete conversion of the fuel. Typical fuel conversions vary between 90 and 95%. The remaining combustible material, also containing most of the biomass ash components, is blown out of the gasifier and removed from the gas stream by a cyclone to

MICROBIOLOGICAL CHARACTERISTICS OF THE AIR BLOWN BY WARM AIR HAND DRYERS

Directory of Open Access Journals (Sweden)

Recai OÐUR; Omer Faruk TEKBAS; Osman HANCI; Umut OZCAN

2005-02-01

Full Text Available The aim of the study was to determine the microbiological characteristics of air blown from warm air hand dryers, and to compare findings with the microbiological characteristics of indoor air in which the dryer settled. Air samples was taken from different public places (shopping centers, restaurants and hospitals and investigated for total viable counts, coagulase negative Staphylococcus, E. Coli, Staphylococcus aureus and enteric pathogens. There were differences between sampling indoor places for some of the microorganisms, but all of the air samples taken from dryers contained more microorganisms than indoor air, and the differences between hand dryers and indoor air were statistically significant (p<0.05 except for enteric pathogens. As a result it could be said that warm air hand dryers could be microbiological contamination sources in restrooms or the other places that they are used. [TAF Prev Med Bull 2005; 4(1.000: 1-7

The causes and consequences of blown-up coal dust

International Nuclear Information System (INIS)

Vrins, E.L.M.; Van Zuylen, E.J.

1991-11-01

The goal of the Dutch National Research Program Coal (NOK), which started in 1983, is to eliminate technical, economic and ecological objections, connected with the large-scale use of coal. The Blown-up Coal Dust program, which is completed in 1991, aimed at problems that arise, due to the dispersion of coal dust in the vicinity of coal storage and transshipment areas. The accumulated knowledge is categorized according to the route the dust itself follows, starting with activities that cause the dust and continuing up to the effects, of which nuisance in the neighborhood is the most important. The successive chapters are: Activities, Emission, Concentration, Deposition, Pollution and Nuisance and other effects. Inventories of available knowledge, models and measuring equipment have been carried out for each part. The models describe the connection between the various stages of the progress of the dust, from cause to consequence. Newly developed measuring equipment was tested in practice. Various analysis techniques were used and evaluated, such as gravimetric, chemical and optical analysis. A specific coal dust analysis technique is not available. 15 figs., 23 tabs., 1 appendix, 263 refs

Inhalation exposure and risk of polycyclic aromatic hydrocarbons (PAHs) among the rural population adopting wood gasifier stoves compared to different fuel-stove users

Science.gov (United States)

Lin, Nan; Chen, Yuanchen; Du, Wei; Shen, Guofeng; Zhu, Xi; Huang, Tianbo; Wang, Xilong; Cheng, Hefa; Liu, Junfeng; Xue, Chunyu; Liu, Guangqing; Zeng, Eddy Y.; Xing, Baoshan; Tao, Shu

2016-12-01

Polycyclic aromatica hydrocarbons (PAHs) are a group of compounds with carcinogenic potentials and residential solid fuel combustion is one major source of PAHs in most developing countries. Replacement of traditional stoves with improved ones is believed to be a practical approach to reduce pollutant emissions, however, field assessments on the performance and consequent impacts on air quality and human health after adopting improved stoves are rare. The study is the first time to quantify inhalation exposure to PAHs among the residents who adopted wood gasifier stoves. The results were compared to those still burning coals in the region and compared to exposure levels for different fuel/stove users in literature. The results showed that the PAHs exposure levels for the wood gasifier stove users were significantly lower than the values for those using traditional wood stoves reported in literature, and the daily exposure concentrations of BaPeq (Benzo[a]pyrene equivalent concentration) can be reduced by 48%-91% if traditional wood stoves were replaced by wood gasifier stoves. The corresponding Incremental Lifetime Cancer Risk (ILCR) decreased approximately four times from 1.94 × 10-4 to 5.17 × 10-5. The average concentration of the total 26 PAHs for the wood users was 1091 ± 722 ng/m3, which was comparable to 1060 ± 927 ng/m3 for those using anthracite coals, but the composition profiles were considerably different. The average BaPeq were 116 and 25.8 ng/m3 for the wood and coal users, respectively, and the corresponding ILCR of the anthracite coal users was 1.69 × 10-5, which was nearly one third of those using the wood gasifier stoves. The wood users exposed to not only high levels of high molecular weight PAHs, but relatively high fractions of particulate phase PAHs in small particles compared to the coal users, resulting in high exposure risks.

TVA coal-gasification commercial demonstration plant project. Volume 5. Plant based on Koppers-Totzek gasifier. Final report

Energy Technology Data Exchange (ETDEWEB)

1980-11-01

This volume presents a technical description of a coal gasification plant, based on Koppers-Totzek gasifiers, producing a medium Btu fuel gas product. Foster Wheeler carried out a conceptual design and cost estimate of a nominal 20,000 TPSD plant based on TVA design criteria and information supplied by Krupp-Koppers concerning the Koppers-Totzek coal gasification process. Technical description of the design is given in this volume.

Cogeneration applications of biomass gasifier/gas turbine technologies in the cane sugar and alcohol industries

International Nuclear Information System (INIS)

Ogden, J.M.; Williams, R.H.; Fulmer, M.E.

1994-01-01

Biomass integrated gasifier/gas turbine (BIG/GT) technologies for cogeneration or stand-alone power applications hold forth the promise of being able to produce electricity at lower cost in many instances than most alternatives, including large central-station, coal-fired, steam-electric power plants with fuel gas desulphurization, nuclear power plants, and hydroelectricity power plants. BIG/GT technologies offer environmental benefits as well, including the potential for zero net carbon dioxide emissions, if the biomass feedstock is grown renewably. (author). 77 refs., 9 figs., 16 tabs

Making the most of South Africa’s low-quality coal: Converting high-ash coal to fuel gas using bubbling fluidised bed gasifiers

CSIR Research Space (South Africa)

Engelbrecht, AD

2010-08-31

Full Text Available for process heating or for power generation using the IGCC (Integrated Gasification Combined Cycle) process. A high-ash coal from the Waterberg coalfield was tested in a bubbling fluidised bed gasifier using various gasification agents and operating conditions...

Development of thermoplastic starch blown film by incorporating plasticized chitosan.

Science.gov (United States)

Dang, Khanh Minh; Yoksan, Rangrong

2015-01-22

The objective of the present work was to improve blown film extrusion processability and properties of thermoplastic starch (TPS) film by incorporating plasticized chitosan, with a content of 0.37-1.45%. The effects of chitosan on extrusion processability and melt flow ability of TPS, as well as that on appearance, optical properties, thermal properties, viscoelastic properties and tensile properties of the films were investigated. The possible interactions between chitosan and starch molecules were evaluated by FTIR and XRD techniques. Chitosan and starch molecules could interact via hydrogen bonds, as confirmed from the blue shift of OH bands and the reduction of V-type crystal formation. Although the incorporation of chitosan caused decreased extensibility and melt flow ability, as well as increased yellowness and opacity, the films possessed better extrusion processability, increased tensile strength, rigidity, thermal stability and UV absorption, as well as reduced water absorption and surface stickiness. The obtained TPS/chitosan-based films offer real potential application in the food industry, e.g. as edible films. Copyright © 2014 Elsevier Ltd. All rights reserved.

Carbon Formation and Metal Dusting in Hot-Gas Cleanup Systems of Coal Gasifiers

Energy Technology Data Exchange (ETDEWEB)

Tortorelli, Peter F.; Judkins, Roddie R.; DeVan, Jackson H.; Wright, Ian G.

1995-12-31

There are several possible materials/systems degradation modes that result from gasification environments with appreciable carbon activities. These processes, which are not necessarily mutually exclusive, include carbon deposition, carburization, metal dusting, and CO disintegration of refractories. Carbon formation on solid surfaces occurs by deposition from gases in which the carbon activity (a sub C) exceeds unity. The presence of a carbon layer CO can directly affect gasifier performance by restricting gas flow, particularly in the hot gas filter, creating debris (that may be deposited elsewhere in the system or that may cause erosive damage of downstream components), and/or changing the catalytic activity of surfaces.

Polystyrene foam products equation of state as a function of porosity and fill gas

Energy Technology Data Exchange (ETDEWEB)

Mulford, Roberta N [Los Alamos National Laboratory; Swift, Damian C [LLNL

2009-01-01

An accurate EOS for polystyrene foam is necessary for analysis of numerous experiments in shock compression, inertial confinement fusion, and astrophysics. Plastic to gas ratios vary between various samples of foam, according to the density and cell-size of the foam. A matrix of compositions has been investigated, allowing prediction of foam response as a function of the plastic-to-air ratio. The EOS code CHEETAH allows participation of the air in the decomposition reaction of the foam. Differences between air-filled, Ar-blown, and CO{sub 2}-blown foams are investigated, to estimate the importance of allowing air to react with products of polystyrene decomposition. O{sub 2}-blown foams are included in some comparisons, to amplify any consequences of reaction with oxygen in air. He-blown foams are included in some comparisons, to provide an extremum of density. Product pressures are slightly higher for oxygen-containing fill gases than for non-oxygen-containing fill gases. Examination of product species indicates that CO{sub 2} decomposes at high temperatures.

Power Systems Development Facility Gasification Test Campaign TC25

Energy Technology Data Exchange (ETDEWEB)

Southern Company Services

2008-12-01

In support of technology development to utilize coal for efficient, affordable, and environmentally clean power generation, the Power Systems Development Facility (PSDF), located in Wilsonville, Alabama, routinely demonstrates gasification technologies using various types of coals. The PSDF is an engineering scale demonstration of key features of advanced coal-fired power systems, including a KBR Transport Gasifier, a hot gas particulate control device, advanced syngas cleanup systems, and high-pressure solids handling systems. This report summarizes the results of TC25, the second test campaign using a high moisture lignite coal from the Red Hills mine in Mississippi as the feedstock in the modified Transport Gasifier configuration. TC25 was conducted from July 4, 2008, through August 12, 2008. During TC25, the PSDF gasification process operated for 742 hours in air-blown gasification mode. Operation with the Mississippi lignite was significantly improved in TC25 compared to the previous test (TC22) with this fuel due to the addition of a fluid bed coal dryer. The new dryer was installed to dry coals with very high moisture contents for reliable coal feeding. The TC25 test campaign demonstrated steady operation with high carbon conversion and optimized performance of the coal handling and gasifier systems. Operation during TC25 provided the opportunity for further testing of instrumentation enhancements, hot gas filter materials, and advanced syngas cleanup technologies. The PSDF site was also made available for testing of the National Energy Technology Laboratory's fuel cell module and Media Process Technology's hydrogen selective membrane with syngas from the Transport Gasifier.

Effect of sewage sludge content on gas quality and solid residues produced by cogasification in an updraft gasifier

Energy Technology Data Exchange (ETDEWEB)

Seggiani, Maurizia, E-mail: m.seggiani@diccism.unipi.it [Department of Chemical Engineering, Industrial Chemistry and Material Science, University of Pisa, Largo Lucio Lazzarino 1, 56126 Pisa (Italy); Puccini, Monica, E-mail: m.puccini@diccism.unipi.it [Department of Chemical Engineering, Industrial Chemistry and Material Science, University of Pisa, Largo Lucio Lazzarino 1, 56126 Pisa (Italy); Raggio, Giovanni, E-mail: g.raggio@tiscali.it [Italprogetti Engineering SPA, Lungarno Pacinotti, 59/A, 56020 San Romano (Pisa) (Italy); Vitolo, Sandra, E-mail: s.vitolo@diccism.unipi.it [Department of Chemical Engineering, Industrial Chemistry and Material Science, University of Pisa, Largo Lucio Lazzarino 1, 56126 Pisa (Italy)

2012-10-15

Highlights: Black-Right-Pointing-Pointer Cogasification of sewage sludge with wood pellets in updraft gasifier was analysed. Black-Right-Pointing-Pointer The effects of sewage sludge content on the gasification process were examined. Black-Right-Pointing-Pointer Sewage sludge addition up to 30 wt.% reduces moderately the process performance. Black-Right-Pointing-Pointer At high sewage sludge content slagging and clinker formation occurred. Black-Right-Pointing-Pointer Solid residues produced resulted acceptable at landfills for non-hazardous waste. - Abstract: In the present work, the gasification with air of dehydrated sewage sludge (SS) with 20 wt.% moisture mixed with conventional woody biomass was investigated using a pilot fixed-bed updraft gasifier. Attention was focused on the effect of the SS content on the gasification performance and on the environmental impact of the process. The results showed that it is possible to co-gasify SS with wood pellets (WPs) in updraft fixed-bed gasification installations. However, at high content of sewage sludge the gasification process can become instable because of the very high ash content and low ash fusion temperatures of SS. At an equivalent ratio of 0.25, compared with wood pellets gasification, the addition of sewage sludge led to a reduction of gas yield in favor of an increase of condensate production with consequent cold gas efficiency decrease. Low concentrations of dioxins/furans and PAHs were measured in the gas produced by SS gasification, well below the limiting values for the exhaust gaseous emissions. NH{sub 3}, HCl and HF contents were very low because most of these compounds were retained in the wet scrubber systems. On the other hand, high H{sub 2}S levels were measured due to high sulfur content of SS. Heavy metals supplied with the feedstocks were mostly retained in gasification solid residues. The leachability tests performed according to European regulations showed that metals leachability was

A Low Cost, High Capacity Regenerable Sorbent for Pre-combustion CO{sub 2} Capture

Energy Technology Data Exchange (ETDEWEB)

Alptekin, Gokhan

2012-09-30

The overall objective of the proposed research is to develop a low cost, high capacity CO{sub 2} sorbent and demonstrate its technical and economic viability for pre-combustion CO{sub 2} capture. The specific objectives supporting our research plan were to optimize the chemical structure and physical properties of the sorbent, scale-up its production using high throughput manufacturing equipment and bulk raw materials and then evaluate its performance, first in bench-scale experiments and then in slipstream tests using actual coal-derived synthesis gas. One of the objectives of the laboratory-scale evaluations was to demonstrate the life and durability of the sorbent for over 10,000 cycles and to assess the impact of contaminants (such as sulfur) on its performance. In the field tests, our objective was to demonstrate the operation of the sorbent using actual coal-derived synthesis gas streams generated by air-blown and oxygen-blown commercial and pilot-scale coal gasifiers (the CO{sub 2} partial pressure in these gas streams is significantly different, which directly impacts the operating conditions hence the performance of the sorbent). To support the field demonstration work, TDA collaborated with Phillips 66 and Southern Company to carry out two separate field tests using actual coal-derived synthesis gas at the Wabash River IGCC Power Plant in Terre Haute, IN and the National Carbon Capture Center (NCCC) in Wilsonville, AL. In collaboration with the University of California, Irvine (UCI), a detailed engineering and economic analysis for the new CO{sub 2} capture system was also proposed to be carried out using Aspen PlusTM simulation software, and estimate its effect on the plant efficiency.

Effect of hydrogen chloride on the corrosion of an FeCrAlY alloy in simulated coal gasifier atmospheres

Energy Technology Data Exchange (ETDEWEB)

Coley, K.S.; Rhoades-Brown, J.E.; Blick, K.

1989-03-01

An iron chromium aluminium yttrium steel was exposed to a simulated coal gasifier atmosphere containing 1000 ppm and 2200 ppm hydrogen chloride at 450/sup 0/C. Increasing hydrogen chloride content was found to accelerate reaction rates, and significantly alter the microstructure and composition of the corrosion product. Tentative explanations for these results, involving vapour phase transport of metal chlorides are proposed.

Climate effect of an integrated wheat production and bioenergy system with Low Temperature Circulating Fluidized Bed gasifier

International Nuclear Information System (INIS)

Sigurjonsson, Hafthor Ægir; Elmegaard, Brian; Clausen, Lasse Røngaard; Ahrenfeldt, Jesper

2015-01-01

Highlights: • Wheat straw removal from agricultural system has considerable GWP effect. • Changing the carbon conv. in the gasifier to 0.8–0.86 mitigates those effects. • Considerable difference is between sequestration potential of straw and biochar. • Lowering the carbon conversion improves GWP, but depends on subst. technology. - Abstract: When removing biomass residues from the agriculture for bioenergy utilization, the nutrients and carbon stored within these “residual resources” are removed as-well. To mitigate these issues the energy industry must try to conserve and not destroy the nutrients. The paper analyses a novel integration between the agricultural system and the energy system through the Low Temperature Circulating Fluidized Bed (LT-CFB) gasifier from the perspective of wheat grain production and electricity generation using wheat straw, where the effects of removing the straw from the agricultural system are assessed along with the effects of recycling the nutrients and carbon back to the agricultural system. The methods used to assess the integration was Life Cycle Assessment (LCA) with IPCC’s 2013 100 year global warming potential (GWP) as impact assessment method. The boundary was set from cradle to gate with two different functional units, kg grain and kW h electricity produced in Zealand, Denmark. Two cases were used in the analysis: 1. nutrient balances are regulated by mineral fertilization and 2. the nutrient balances are regulated by yield. The analysis compare three scenarios of gasifier operation based on carbon conversion to two references, no straw removal and straw combustion. The results show that the climate effect of removing the straws are mitigated by the carbon soil sequestration with biochar, and electricity and district heat substitution. Maximum biochar production outperforms maximum heat and power generation for most substituted electricity and district heating scenarios. Irrespective of the substituted

Potentials of Selected Malaysian Biomasses as Co-Gasification Fuels with Oil Palm Fronds in a Fixed-Bed Downdraft Gasifier

Directory of Open Access Journals (Sweden)

Moni Mohamad Nazmi Zaidi

2014-07-01

Full Text Available Oil palm frond (OPF has been successfully gasified to produce syngas and has since deemed as a potential source of biomass fuel in Malaysia. However, if OPF is to be utilized as a main fuel for industrial-scale firing/gasification plant, interruption in fuel supply may occur due to numerous reasons, for instance inefficient fuel processing and ineffective transportation. A secondary supporting solid fuel is therefore necessary as a partial component to the main fuel in such cases, where the secondary fuel is combusted with the main fuel to adhere to main fuel shortage. Gasification of two fuels together, known as co-gasification, is practiced worldwide, some in industrial scale. However, current practice utilizes biomass fuel as the secondary fuel to coal in co-gasification. This investigation explores into the feasibility of co-gasifying two biomass fuels together to produce syngas. OPF was chosen as the primary fuel and a selection of Malaysian biomasses were studied to discover their compatibility with OPF in co-gasification. Biomass selection was made using score-and-rank method and their selection criteria are concisely discussed.

Pyrolysis of Pinus pinaster in a two-stage gasifier: Influence of processing parameters and thermal cracking of tar

Energy Technology Data Exchange (ETDEWEB)

Fassinou, Wanignon Ferdinand; Toure, Siaka [Laboratoire d' Energie Solaire-UFR-S.S.M.T. Universite de Cocody, 22BP582 Abidjan 22 (Ivory Coast); Van de Steene, Laurent; Volle, Ghislaine; Girard, Philippe [CIRAD-Foret, TA 10/16, 73, avenue J.-F. Breton, 34398 Montpellier, Cedex 5 (France)

2009-01-15

A new two-stage gasifier with fixed-bed has recently been installed on CIRAD facilities in Montpellier. The pyrolysis and the gasifier units are removable. In order to characterise the pyrolysis products before their gasification, experiments were carried out, for the first time only with the pyrolysis unit and this paper deals with the results obtained. The biomass used is Pinus pinaster. The parameters investigated are: temperature, residence time and biomass flow rate. It has been found that increasing temperature and residence time improve the cracking of tars, gas production and char quality (fixed carbon rate more than 90%, volatile matter rate less than 4%). The increase of biomass flow rate leads to a bad char quality. The efficiency of tar cracking, the quality and the heating value of the charcoal and the gases, indicate that: temperature between 650 C and 750 C, residence time of 30 min, biomass flow rate between 10 and 15 kg/h should be the most convenient experimental conditions to get better results from the experimental device and from the biomass pyrolysis process. The kinetic study of charcoal generation shows that the pyrolysis process, in experimental conditions, is a first-order reaction. The kinetic parameters calculated are comparable with those found by other researchers. (author)

Properties and effects of remaining carbon from waste plastics gasifying on iron scale reduction.

Science.gov (United States)

Zhang, Chongmin; Chen, Shuwen; Miao, Xincheng; Yuan, Hao

2011-06-01

The carbonous activities of three kinds of carbon-bearing materials gasified from plastics were tested with coal coke as reference. The results showed that the carbonous activities of these remaining carbon-bearing materials were higher than that of coal-coke. Besides, the fractal analyses showed that the porosities of remaining carbon-bearing materials were higher than that of coal-coke. It revealed that these kinds of remaining carbon-bearing materials are conducive to improve the kinetics conditions of gas-solid phase reaction in iron scale reduction. Copyright © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Catalytic upgrading nitrogen-riched wood syngas to liquid hydrocarbon mixture over Fe-Pd/ZSM-5 catalyst

Science.gov (United States)

Qiangu Yan; Fei Yu; Zhiyong Cai; Jilei Zhang

2012-01-01

Biomass like wood chips, switchgrass and other plant residues are first converted to syngas through gasification process using air, oxygen or steam. A downdraft gasifier is performed for syngas production in Mississippi State. The syngas from the gasifier contains up to 49% (vol) N2. High-level nitrogen-containing (nitrogen can be up to 60%)...

IRAS 18153-1651: an H II region with a possible wind bubble blown by a young main-sequence B star

Science.gov (United States)

Gvaramadze, V. V.; Mackey, J.; Kniazev, A. Y.; Langer, N.; Chené, A.-N.; Castro, N.; Haworth, T. J.; Grebel, E. K.

2017-04-01

We report the results of spectroscopic observations and numerical modelling of the H II region IRAS 18153-1651. Our study was motivated by the discovery of an optical arc and two main-sequence stars of spectral type B1 and B3 near the centre of IRAS 18153-1651. We interpret the arc as the edge of the wind bubble (blown by the B1 star), whose brightness is enhanced by the interaction with a photoevaporation flow from a nearby molecular cloud. This interpretation implies that we deal with a unique case of a young massive star (the most massive member of a recently formed low-mass star cluster) caught just tens of thousands of years after its stellar wind has begun to blow a bubble into the surrounding dense medium. Our 2D, radiation-hydrodynamics simulations of the wind bubble and the H II region around the B1 star provide a reasonable match to observations, both in terms of morphology and absolute brightness of the optical and mid-infrared emission, and verify the young age of IRAS 18153-1651. Taken together our results strongly suggest that we have revealed the first example of a wind bubble blown by a main-sequence B star.

Wind-blown sandstones cemented by sulfate and clay minerals in Gale Crater, Mars

Science.gov (United States)

Milliken, R. E.; Ewing, R. C.; Fischer, W. W.; Hurowitz, J.

2014-02-01

Gale Crater contains Mount Sharp, a ~5 km thick stratigraphic record of Mars' early environmental history. The strata comprising Mount Sharp are believed to be sedimentary in origin, but the specific depositional environments recorded by the rocks remain speculative. We present orbital evidence for the occurrence of eolian sandstones within Gale Crater and the lower reaches of Mount Sharp, including preservation of wind-blown sand dune topography in sedimentary strata—a phenomenon that is rare on Earth and typically associated with stabilization, rapid sedimentation, transgression, and submergence of the land surface. The preserved bedforms in Gale are associated with clay minerals and elsewhere accompanied by typical dune cross stratification marked by bounding surfaces whose lateral equivalents contain sulfate salts. These observations extend the range of possible habitable environments that may be recorded within Gale Crater and provide hypotheses that can be tested in situ by the Curiosity rover payload.

Electricity cogeneration evaluation from cane bagasse in gasifier systems/gas turbine; Avaliacao da cogeracao de eletricidade a partir de bagaco de cana em sistemas de gaseificador/turbina a gas

Energy Technology Data Exchange (ETDEWEB)

Coelho, Suani Teixeira

1992-07-01

Before the beginning of PROALCOOL in 1975, the first effective program in the world using biomass in large scale as an automotive fuel, sugar/alcohol industries already used sugar cane bagasse - a by-product of sugar/alcohol production - to generate energy for sugar production. Currently, besides the fact that they are self-sufficient in thermal/electrical energy, sugar/alcohol industries produce small electricity excess which is exported to local utilities. Gasifier/gas turbine systems are more advanced technologies which are being developed and shall be commercialized in eight to ten years approximately, presenting much higher efficiency, at low cost and inducing more exportable electricity. In this study, possibilities of gasifier/gas turbine systems are evaluated and projections of bagasse based electricity production are presented, until year 2010, for Sao Paulo state and Brazil. Generation costs of gasified bagasse based electricity are calculated: they shall be lower than electricity cost from fossil origin. Influence of electricity sale on the reduction of alcohol production cost are also evaluated for several opportunity costs of bagasse. Environmental and social impacts are analyzed, including evaluation of the cost of avoided carbon, related to the substitution of fossil fuel by sugar cane bagasse in thermoelectric power plants. (author)

Biomass-gasifier steam-injected gas turbine cogeneration for the cane sugar industry

International Nuclear Information System (INIS)

Larson, E.D.; Williams, R.H.; Ogden, J.M.; Hylton, M.G.

1991-01-01

Steam injection for power and efficiency augmentation in aeroderivative gas turbines has been commercially established for natural gas-fired cogeneration since 1980. Steam-injected gas turbines fired with coal and biomass are being developed. A performance and economic assessment of biomass integrated-gasifier steam-injected gas turbine (BIG/STIG) cogeneration systems is carried out here. A detailed economic case study is presented for the second largest sugar factory in Jamaica, with cane residues as the fuel. BIG/STIG cogeneration units would be attractive investments for sugar producers, who could sell large quantities of excess electricity to the utility, or for the utility, as a low-cost generating option. Worldwide, the cane sugar industry could support some 50,000 MW of BIG/STIG electric generation capacity. The relatively modest development effort required to commercialize the BIG/STIG technology is discussed in a companion paper prepared for this conference

Opportunities for and limits to Academics as System builders-The case of realizing the potential of gasified biomass in Austria

International Nuclear Information System (INIS)

Hellsmark, Hans; Jacobsson, Staffan

2009-01-01

Gasified biomass is a technology that has the potential to partially replace fossil fuels for the production of heat, electricity, transport fuels, synthetic natural gas (BioSNG) and chemicals. In the context of climate change, biomass gasification is an attractive technology. It is, however, still in the early phase of its diffusion and much of the knowledge resides in the academic sector and in small companies-the technological innovation system (TIS) is in the process of being formed. Austria is one of the leading European countries in this field and much of the development in Austria can be traced to one prominent individual, Professor Hermann Hofbauer at the Technical University of Vienna. The purpose of this paper is to analyze how and the extent to which an individual academic, Professor Hofbauer, has influenced the formation of a TIS centred on gasified biomass in Austria. We find that his impact is multidimensional and significant but that there is also a frictional and intentional resistance that obstructs the commercialisation of the new technology. These sources of resistance go beyond the ability of an individual system builder to handle. Policy makers, therefore, need to add a strong element of system building activities that interact with and supplement those pursued by Professor Hofbauer.

Detailed model for practical pulverized coal furnaces and gasifiers

Energy Technology Data Exchange (ETDEWEB)

Smith, P.J.; Smoot, L.D.

1989-08-01

This study has been supported by a consortium of nine industrial and governmental sponsors. Work was initiated on May 1, 1985 and completed August 31, 1989. The central objective of this work was to develop, evaluate and apply a practical combustion model for utility boilers, industrial furnaces and gasifiers. Key accomplishments have included: Development of an advanced first-generation, computer model for combustion in three dimensional furnaces; development of a new first generation fouling and slagging submodel; detailed evaluation of an existing NO{sub x} submodel; development and evaluation of an improved radiation submodel; preparation and distribution of a three-volume final report: (a) Volume 1: General Technical Report; (b) Volume 2: PCGC-3 User's Manual; (c) Volume 3: Data Book for Evaluation of Three-Dimensional Combustion Models; and organization of a user's workshop on the three-dimensional code. The furnace computer model developed under this study requires further development before it can be applied generally to all applications; however, it can be used now by specialists for many specific applications, including non-combusting systems and combusting geseous systems. A new combustion center was organized and work was initiated to continue the important research effort initiated by this study. 212 refs., 72 figs., 38 tabs.

Role of Chinese wind-blown dust in enhancing environmental pollution in Metropolitan Seoul

Energy Technology Data Exchange (ETDEWEB)

Kim, Wonnyon [Department of Earth and Environmental Sciences, Korea University, Seoul 136-713 (Korea, Republic of); Doh, Seong-Jae [Department of Earth and Environmental Sciences, Korea University, Seoul 136-713 (Korea, Republic of)], E-mail: sjdoh@korea.ac.kr; Yu, Yongjae; Lee, Meehye [Department of Earth and Environmental Sciences, Korea University, Seoul 136-713 (Korea, Republic of)

2008-05-15

A suite of rock magnetic experiments and intensive microscopic observations were carried out on Asian dust deposits in Seoul, Korea, collected on 19 and 23 March 2002, 9 April 2002 and 12 April 2003. Desert-sand and loess from the dust source regions in China were also analyzed as a comparison. Asian dust showed a higher magnetic concentration than the source region samples, indicating a significant influx of magnetic particles into Asian dust had occurred during its transportation. Electron microscopy identified carbon-bearing iron-oxides as the added material. These iron-oxides were likely to have been produced by anthropogenic pollution (fossil fuel combustion) while the wind-blown dusts passing across the industrial areas of eastern China and western Korea. Such wind-paths were confirmed by a simulation of the air-mass trajectories. The magnetic technique appears to be useful for determining the anthropogenic pollution of Asian dust. - Magnetic quantification of anthropogenic pollution of Asian dust.

Role of Chinese wind-blown dust in enhancing environmental pollution in Metropolitan Seoul

International Nuclear Information System (INIS)

Kim, Wonnyon; Doh, Seong-Jae; Yu, Yongjae; Lee, Meehye

2008-01-01

A suite of rock magnetic experiments and intensive microscopic observations were carried out on Asian dust deposits in Seoul, Korea, collected on 19 and 23 March 2002, 9 April 2002 and 12 April 2003. Desert-sand and loess from the dust source regions in China were also analyzed as a comparison. Asian dust showed a higher magnetic concentration than the source region samples, indicating a significant influx of magnetic particles into Asian dust had occurred during its transportation. Electron microscopy identified carbon-bearing iron-oxides as the added material. These iron-oxides were likely to have been produced by anthropogenic pollution (fossil fuel combustion) while the wind-blown dusts passing across the industrial areas of eastern China and western Korea. Such wind-paths were confirmed by a simulation of the air-mass trajectories. The magnetic technique appears to be useful for determining the anthropogenic pollution of Asian dust. - Magnetic quantification of anthropogenic pollution of Asian dust

Achievement report for fiscal 1997 on investigative research on society compatibility of development of coal hydrogasification technology; 1997 nendo sekitan suiso tenka gas ka gijutsu kaihatsu shakai tekigosei ni kansuru chosa kenkyu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-03-01

In view of possibility of the future tightness in natural gas supply, establishment of coal gasification technology was set as the final objective, which can supply cheaply and stably the substitution natural gas of high quality by using coal existing affluently over the world as the raw material. An investigative research is carried out under a five-year plan on society compatibility required to assess the possibility of the practical application thereof. Fiscal 1997 has performed in continuation from the previous year the 'survey on process level elevation' and 'survey on the society compatibility'. This report summarizes the achievements thereon. In the investigative research on the process level elevation, the Shell's methane synthesis process based on an oxygen blown and dry feed coal gasifier was evaluated, and the calculation process was pursued on material balance in a hydrogasification reactor as having been performed in the 'survey on developing the coal hydrogasification technology' in which its reasonability was verified. In the survey on the society compatibility of the process, a survey was carried out on natural gas (including non-conventional methane hydrate and coal bed methane) and coals as raw materials for hydrogasification. (NEDO)

Low-Cost Syngas Shifting for Remote Gasifiers: Combination of CO2 Adsorption and Catalyst Addition in a Novel and Simplified Packed Structure

Directory of Open Access Journals (Sweden)

Ricardo A. Narváez C.

2018-02-01

Full Text Available This paper presents the technical validation of a novel, low-complexity alternative based on the inclusion of a patented (IEPI-MU-2016-185 packed bed for improving the performance of remote, small-scale gasification facilities. This study was carried out in an updraft, atmospheric-pressure gasifier, outfitted with a syngas reflux line, air and oxygen feed, and an upper packed-bed coupled to the gasification unit to improve the syngas quality by catalytic treatment and CO2 adsorption. The experimental facility is located in the rural community San Pedro del Laurel, Ecuador. Gasification experiments, with and without packed material in the upper chamber, were performed to assess its effect on the syngas quality. The assessment revealed that the packed material increases the carbon monoxide (CO content in the syngas outlet stream while carbon dioxide (CO2 was reduced. This option appears to be a suitable and low-complexity alternative for enhancing the content of energy vectors of syngas in gasification at atmospheric pressure since CO/CO2 ratios of 5.18 and 3.27 were achieved against reported values of 2.46 and 0.94 for operations which did not include the addition of packed material. It is concluded that the upper packed-bed is an active element able to modify syngas characteristics since CO2 content was reduced.

Phosphorus leaching from soils amended with thermally gasified piggery waste ash

DEFF Research Database (Denmark)

Kuligowski, Ksawery; Poulsen, Tjalfe

2009-01-01

In regions with intensive livestock farming, thermal treatment for local energy extraction from the manure and export of the P rich ash as a fertilizer has gained interest. One of the main risks associated with P fertilizers is eutrophication of water bodies. In this study P and K mobility in ash...... from anaerobically digested, thermally gasified (GA) and incinerated (IA) piggery waste has been tested using water loads ranging from 0.1 to 200 ml g−1. Leaching of P from soil columns amended with GA was investigated for one P application rate (205 kg P ha−1 corresponding to 91 mg P kg−1 soil dry...... matter) as a function of precipitation rate (9.5 and 2.5 mm h−1), soil type (Jyndevad agricultural soil and sand), amount of time elapsed between ash amendment and onset of precipitation (0 and 5 weeks) and compared to leaching from soils amended with a commercial fertilizer (Na2HPO4). Water soluble P...

Catalytic destruction of tar in biomass derived producer gas

International Nuclear Information System (INIS)

Zhang Ruiqin; Brown, Robert C.; Suby, Andrew; Cummer, Keith

2004-01-01

The purpose of this study is to investigate catalytic destruction of tar formed during gasification of biomass, with the goal of improving the quality of the producer gas. This work focuses on nickel based catalysts treated with alkali in an effort to promote steam gasification of the coke that deposits on catalyst surfaces. A tar conversion system consisting of a guard bed and catalytic reactor was designed to treat the producer gas from an air blown, fluidized bed biomass gasifier. The guard bed used dolomite to crack the heavy tars. The catalytic reactor was used to evaluate three commercial steam reforming catalysts. These were the ICI46-1 catalyst from Imperial Chemical Industry and Z409 and RZ409 catalysts from Qilu Petrochemical Corp. in China. A 0.5-3 l/min slipstream from a 5 tpd biomass gasifier was used to test the tar conversion system. Gas and tar were sampled before and after the tar conversion system to evaluate the effectiveness of the system. Changes in gas composition as functions of catalytic bed temperature, space velocity and steam/TOC (total organic carbon) ratio are presented. Structural changes in the catalysts during the tests are also described

Power Systems Development Facility

Energy Technology Data Exchange (ETDEWEB)

None

2003-07-01

This report discusses Test Campaign TC12 of the Kellogg Brown & Root, Inc. (KBR) Transport Gasifier train with a Siemens Westinghouse Power Corporation (SW) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The Transport Gasifier is an advanced circulating fluidized-bed reactor designed to operate as either a combustor or a gasifier using a particulate control device (PCD). While operating as a gasifier, either air or oxygen can be used as the oxidant. Test run TC12 began on May 16, 2003, with the startup of the main air compressor and the lighting of the gasifier start-up burner. The Transport Gasifier operated until May 24, 2003, when a scheduled outage occurred to allow maintenance crews to install the fuel cell test unit and modify the gas clean-up system. On June 18, 2003, the test run resumed when operations relit the start-up burner, and testing continued until the scheduled end of the run on July 14, 2003. TC12 had a total of 733 hours using Powder River Basin (PRB) subbituminous coal. Over the course of the entire test run, gasifier temperatures varied between 1,675 and 1,850 F at pressures from 130 to 210 psig.

Potential of synthesis gas production from rubber wood chip gasification in a bubbling fluidised bed gasifier

International Nuclear Information System (INIS)

Kaewluan, Sommas; Pipatmanomai, Suneerat

2011-01-01

Experiments of rubber wood chip gasification were carried out in a 100-kW th bubbling fluidised bed gasifier to investigate the effect of air to fuel ratio (represented as equivalence ratio - ER) on the yield and properties of synthesis gas. For all experiments, the flow rate of ambient air was fixed, while the feed rate of rubber wood chip was adjusted to vary ER in the range of 0.32-0.43. Increasing ER continuously raised the bed temperature, which resulted in higher synthesis gas yield and lower yield of ash and tar. However, higher ER generally gave synthesis gas of lower heating value, partly due to the dilution of N 2 . Considering the energy efficiency of the process, the optimum operation was achieved at ER = 0.38, which yielded 2.33 Nm 3 of synthesis gas per kg of dry biomass at the heating value of 4.94 MJ/Nm 3 . The calculated carbon conversion efficiency and gasification efficiency were 97.3% and 80.2%, respectively. The mass and energy balance of the gasification process showed that the mass and energy distribution was significantly affected by ER and that the energy losses accounted for ∼25% of the total output energy. The economical assessment of synthesis gas utilisation for heat and electricity production based on a 1-MW th bubbling fluidised bed gasifier and the operational data resulting from the rubber wood chip gasification experiments in this study clearly demonstrated the attractiveness of replacing heavy fuel oil and natural gas by the synthesis gas for heat applications in terms of 70% and 50% annual saving of fuel cost, respectively. However, the case of electricity production does not seem a preferable option due to its current technical and non-technical barriers.

A Water Model Study on Mixing Behavior of the Two-Layered Bath in Bottom Blown Copper Smelting Furnace

Science.gov (United States)

Shui, Lang; Cui, Zhixiang; Ma, Xiaodong; Jiang, Xu; Chen, Mao; Xiang, Yong; Zhao, Baojun

2018-05-01

The bottom-blown copper smelting furnace is a novel copper smelter developed in recent years. Many advantages of this furnace have been found, related to bath mixing behavior under its specific gas injection scheme. This study aims to use an oil-water double-phased laboratory-scale model to investigate the impact of industry-adjustable variables on bath mixing time, including lower layer thickness, gas flow rate, upper layer thickness and upper layer viscosity. Based on experimental results, an overall empirical relationship of mixing time in terms of these variables has been correlated, which provides the methodology for industry to optimize mass transfer in the furnace.

An investigation into heat recovery from the surface of a cyclone dust collector attached to a downdraft biomass gasifier

International Nuclear Information System (INIS)

Nwokolo, Nwabunwanne; Mamphweli, Sampson; Makaka, Golden

2016-01-01

Highlights: • At a temperature of 450 °C–500 °C, hot syngas is regarded as a good heat carrier. • A significant quantity of energy (665893.07 kcal) is lost via the surface of the cyclone. • The surface temperature 150 °C–220 °C was within the low waste heat recovery temperature. - Abstract: The gas leaving the reactor of a downdraft biomass gasifier contains large quantities of heat energy; this is due to the fact that the gas passes through a hot bed of charcoal before leaving the reactor. This heat is normally wasted in the gas scrubber/cooler that cools it from between 400 °C–500 °C to ambient temperature (around 25 °C). The waste heat stream under consideration is the raw syngas that emanates from a gasification process in a downdraft gasifier situated at Melani Village, Eastern Cape. This loss of heat is undesirable as it impacts on the thermal efficiency of the system. This study investigates the feasibility of heat recovery from the surface of the cyclone dust collector prior to entering the gas scrubber. It was shown that there was a downward decrease in temperature along the length of the cyclone. It is found that the total quantity of heat contained in the gas was 665893.07 kcal, which could indicate the viability of recovering heat from the cyclone.

Gasification and co-gasification of biomass wastes: Effect of the biomass origin and the gasifier operating conditions

Energy Technology Data Exchange (ETDEWEB)

Lapuerta, Magin; Hernandez, Juan J.; Pazo, Amparo; Lopez, Julio [Universidad de Castilla-La Mancha, Escuela Tecnica Superior de Ingenieros Industriales (Edificio Politecnico), Avenida Camilo Jose Cela s/n. 13071 Ciudad Real (Spain)

2008-09-15

Air gasification of different biomass fuels, including forestry (pinus pinaster pruning) and agricultural (grapevine and olive tree pruning) wastes as well as industry wastes (sawdust and marc of grape), has been carried out in a circulating flow gasifier in order to evaluate the potential of using these types of biomass in the same equipment, thus providing higher operation flexibility and minimizing the effect of seasonal fuel supply variations. The potential of using biomass as an additional supporting fuel in coal fuelled power plants has also been evaluated through tests involving mixtures of biomass and coal-coke, the coke being a typical waste of oil companies. The effect of the main gasifier operating conditions, such as the relative biomass/air ratio and the reaction temperature, has been analysed to establish the conditions allowing higher gasification efficiency, carbon conversion and/or fuel constituents (CO, H{sub 2} and CH{sub 4}) concentration and production. Results of the work encourage the combined use of the different biomass fuels without significant modifications in the installation, although agricultural wastes (grapevine and olive pruning) could to lead to more efficient gasification processes. These latter wastes appear as interesting fuels to generate a producer gas to be used in internal combustion engines or gas turbines (high gasification efficiency and gas yield), while sawdust could be a very adequate fuel to produce a H{sub 2}-rich gas (with interest for fuel cells) due to its highest reactivity. The influence of the reaction temperature on the gasification characteristics was not as significant as that of the biomass/air ratio, although the H{sub 2} concentration increased with increasing temperature. (author)

Production of methanol/DME from biomass

DEFF Research Database (Denmark)

Ahrenfeldt, Jesper; Henriksen, Ulrik Birk; Münster-Swendsen, Janus

In this project the production of DME/methanol from biomass has been investigated. Production of DME/methanol from biomass requires the use of a gasifier to transform the solid fuel to a synthesis gas (syngas) - this syngas can then be catalytically converted to DME/methanol. Two different gasifier...... cleaning. This was proved by experiments. Thermodynamic computer models of DME and methanol plants based on using the Two-Stage Gasification concept were created to show the potential of such plants. The models showed that the potential biomass to DME/methanol + net electricity energy efficiency was 51...... gasification, but little information exists on using these types of gasifiers for biomass gasification. The experiments performed provided quantitative data on product and gas composition as a function of operation conditions. Biomass can be gasified with less oxygen consumption compared to coal. The organic...

Computational Fluid Dynamics (CFD) Investigation of Submerged Combustion Behavior in a Tuyere Blown Slag-fuming Furnace

Science.gov (United States)

Huda, Nazmul; Naser, Jamal; Brooks, G. A.; Reuter, M. A.; Matusewicz, R. W.

2012-10-01

A thin-slice computational fluid dynamics (CFD) model of a conventional tuyere blown slag-fuming furnace has been developed in Eulerian multiphase flow approach by employing a three-dimensional (3-D) hybrid unstructured orthographic grid system. The model considers a thin slice of the conventional tuyere blown slag-fuming furnace to investigate details of fluid flow, submerged coal combustion dynamics, coal use behavior, jet penetration behavior, bath interaction conditions, and generation of turbulence in the bath. The model was developed by coupling the CFD with the kinetics equations developed by Richards et al. for a zinc-fuming furnace. The model integrates submerged coal combustion at the tuyere tip and chemical reactions with the heat, mass, and momentum interfacial interaction between the phases present in the system. A commercial CFD package AVL Fire 2009.2 (AVL, Graz, Austria) coupled with several user-defined subroutines in FORTRAN programming language were used to develop the model. The model predicted the velocity, temperature field of the molten slag bath, generated turbulence and vortex, and coal use behavior from the slag bath. The tuyere jet penetration length ( l P) was compared with the equation provided by Hoefele and Brimacombe from isothermal experimental work ( {{l_{{P}} }/{d_{o }} = 10.7( {N^' }_{Fr} } )^{0.46} ( {ρ_{{g}} /ρl } )^{0.35} } ) and found 2.26 times higher, which can be attributed to coal combustion and gas expansion at a high temperature. The jet expansion angle measured for the slag system studied is 85 deg for the specific inlet conditions during the simulation time studied. The highest coal penetration distance was found to be l/L = 0.2, where l is the distance from the tuyere tip along the center line and L is the total length (2.44 m) of the modeled furnace. The model also predicted that 10 pct of the injected coal bypasses the tuyere gas stream uncombusted and carried to the free surface by the tuyere gas stream, which

Energy study of the energy supply systems for isolated communities in Cuba from the use of biomass gasifiers downdraft

International Nuclear Information System (INIS)

Pla Duparté, Manuel

2015-01-01

At work a comprehensive energy analysis of plants generating electricity from the gasification of various biomass that currently conceived by the management of the Electric Union for the electrification of isolated communities in the fields of Cuba is made. For this, based on the properties of the main biomass available, the calculations needed are performed to evaluate the efficiency of the gasifier and other components of energy transformation system. The power generation are taken into consideration and an assessment of the needs of biomass in each case is made. (full text)

DEVELOPMENT OF REACTION-DRIVEN IONIC TRANSPORT MEMBRANES (ITMs) TECHNOLOGY: PHASE IV/BUDGET PERIOD 6 “Development of ITM Oxygen Technology for Integration in IGCC and Other Advanced Power Generation Systems”

Energy Technology Data Exchange (ETDEWEB)

David, Studer

2012-03-01

Air Products and Chemicals, along with development participants and in association with the U.S. Department of Energy, has made substantial progress in developing a novel air separation technology. Unlike conventional cryogenic processes, this method uses high-temperature ceramic membranes to produce high-purity oxygen. The membranes selectively transport oxygen ions with high flux and infinite theoretical selectivity. Reaction-driven ceramic membranes are fabricated from non-porous, multi-component metallic oxides, operate at temperatures typically over 700°C, and have exceptionally high oxygen flux and selectivity. Oxygen from low-pressure air permeates as oxygen ions through the ceramic membrane and is consumed through chemical reactions, thus creating a chemical driving force that pulls oxygen ions across the membrane at high rates. The oxygen reacts with a hydrocarbon fuel in a partial oxidation process to produce a hydrogen and carbon monoxide mixture – synthesis gas. This project expands the partial-oxidation scope of ITM technology beyond natural gas feed and investigates the potential for ITM reaction-driven technology to be used in conjunction with gasification and pyrolysis technologies to provide more economical routes for producing hydrogen and synthesis gas. This report presents an overview of the ITM reaction-driven development effort, including ceramic materials development, fabrication and testing of small-scale ceramic modules, ceramic modeling, and the investigation of gasifier integration schemes

Thermal valorization of post-consumer film waste in a bubbling bed gasifier.

Science.gov (United States)

Martínez-Lera, S; Torrico, J; Pallarés, J; Gil, A

2013-07-01

The use of plastic bags and film packaging is very frequent in manifold sectors and film waste is usually present in different sources of municipal and industrial wastes. A significant part of it is not suitable for mechanical recycling but could be safely transformed into a valuable gas by means of thermal valorization. In this research, the gasification of film wastes has been experimentally investigated through experiments in a fluidized bed reactor of two reference polymers, polyethylene and polypropylene, and actual post-consumer film waste. After a complete experimental characterization of the three materials, several gasification experiments have been performed to analyze the influence of the fuel and of equivalence ratio on gas production and composition, on tar generation and on efficiency. The experiments prove that film waste and analogue polymer derived wastes can be successfully gasified in a fluidized bed reactor, yielding a gas with a higher heating value in a range from 3.6 to 5.6 MJ/m3 and cold gas efficiencies up to 60%. Copyright © 2013 Elsevier Ltd. All rights reserved.

Antimicrobial Activity of Nisin and Natamycin Incorporated Sodium Caseinate Extrusion-Blown Films: A Comparative Study with Heat-Pressed/Solution Cast Films.

Science.gov (United States)

Colak, Basak Yilin; Peynichou, Pierre; Galland, Sophie; Oulahal, Nadia; Prochazka, Frédéric; Degraeve, Pascal

2016-05-01

Antimicrobial edible films based on sodium caseinate, glycerol, and 2 food preservatives (nisin or natamycin) were prepared by classical thermomechanical processes. Food preservatives were compounded (at 65 °C for 2.5 min) with sodium caseinate in a twin-screw extruder. Anti-Listeria activity assays revealed a partial inactivation of nisin following compounding. Thermoplastic pellets containing food preservatives were then used to manufacture films either by blown-film extrusion process or by heat-press. After 24 h of incubation on agar plates, the diameters of K. rhizophila growth inhibition zones around nisin-incorporated films prepared by solution casting (control), extrusion blowing or heat pressing at 80 °C for 7 min of nisin-containing pellets were 15.5 ± 0.9, 9.8 ± 0.2, and 8.6 ± 1.0 mm, respectively. Since heat-pressing for 7 min at 80 °C of nisin-incorporated pellets did not further inactivate nisin, this indicates that nisin inactivation during extrusion-blowing was limited. Moreover, the lower diameter of the K. rhizophila growth inhibition zone around films prepared with nisin-containing pellets compared to that observed around films directly prepared by solution casting confirms that nisin inactivation mainly occurred during the compounding step. Natamycin-containing thermoplastic films inhibited Aspergillus niger growth; however, by contrast with nisin-containing films, heat-pressed films had higher inhibition zone diameters than blown films, therefore suggesting a partial inactivation of natamycin during extrusion-blowing. © 2016 Institute of Food Technologists®

Formation and removal of biomass-derived contaminants in fluidized-bed gasification processes

Energy Technology Data Exchange (ETDEWEB)

Kurkela, E [VTT Energy, Espoo (Finland). Energy Production Technologies

1997-12-31

The objectives of this thesis were to examine the effects of the feedstock and the operating conditions of a fluidized-bed gasifier on the formation of tars and nitrogen-containing compounds and to study the effectiveness of the hot gas cleaning methods developed for the removal of particulates, alkali metals, tars and nitrogen-containing compounds. The most essential part of the work was carried out in the pressurized fluidized-bed gasification test facilities composed of an air-blown bubbling fluidized-bed gasifier and subsequent hot gas filter unit. The operation pressure of the test rig could be varied in the range 0.3 - 1.0 MPa and the maximum allowable gasification temperature was 1 050 deg C. The maximum capacity with biomass fuels was 80 kg/h. A wide range of feedstocks from hard coals, lignite and peat to different wood derived fuels and straw were used in the gasification tests. Two different types of ceramic filters were tested in the filter unit connected to the pressurized fluidized-bed gasifier. The filter unit was operated in a temperature range of 400 - 740 deg C. The particulate removal requirements set by the gas turbines were met by both types of filters and with product gases derived from all the feedstocks tested. In addition to the gasification and gas filtration tests, catalytic tar and ammonia decomposition was studied using both laboratory and bench-scale test facilities. Inexpensive calcium-based bulk materials, dolomites and limestones, were efficient tar decomposition catalysts in atmospheric-pressure tests

Formation and removal of biomass-derived contaminants in fluidized-bed gasification processes

Energy Technology Data Exchange (ETDEWEB)

Kurkela, E. [VTT Energy, Espoo (Finland). Energy Production Technologies

1996-12-31

The objectives of this thesis were to examine the effects of the feedstock and the operating conditions of a fluidized-bed gasifier on the formation of tars and nitrogen-containing compounds and to study the effectiveness of the hot gas cleaning methods developed for the removal of particulates, alkali metals, tars and nitrogen-containing compounds. The most essential part of the work was carried out in the pressurized fluidized-bed gasification test facilities composed of an air-blown bubbling fluidized-bed gasifier and subsequent hot gas filter unit. The operation pressure of the test rig could be varied in the range 0.3 - 1.0 MPa and the maximum allowable gasification temperature was 1 050 deg C. The maximum capacity with biomass fuels was 80 kg/h. A wide range of feedstocks from hard coals, lignite and peat to different wood derived fuels and straw were used in the gasification tests. Two different types of ceramic filters were tested in the filter unit connected to the pressurized fluidized-bed gasifier. The filter unit was operated in a temperature range of 400 - 740 deg C. The particulate removal requirements set by the gas turbines were met by both types of filters and with product gases derived from all the feedstocks tested. In addition to the gasification and gas filtration tests, catalytic tar and ammonia decomposition was studied using both laboratory and bench-scale test facilities. Inexpensive calcium-based bulk materials, dolomites and limestones, were efficient tar decomposition catalysts in atmospheric-pressure tests

DOE Coal Gasification Multi-Test Facility: fossil fuel processing technical/professional services

Energy Technology Data Exchange (ETDEWEB)

Hefferan, J.K.; Lee, G.Y.; Boesch, L.P.; James, R.B.; Rode, R.R.; Walters, A.B.

1979-07-13

A conceptual design, including process descriptions, heat and material balances, process flow diagrams, utility requirements, schedule, capital and operating cost estimate, and alternative design considerations, is presented for the DOE Coal Gasification Multi-Test Facility (GMTF). The GMTF, an engineering scale facility, is to provide a complete plant into which different types of gasifiers and conversion/synthesis equipment can be readily integrated for testing in an operational environment at relatively low cost. The design allows for operation of several gasifiers simultaneously at a total coal throughput of 2500 tons/day; individual gasifiers operate at up to 1200 tons/day and 600 psig using air or oxygen. Ten different test gasifiers can be in place at the facility, but only three can be operated at one time. The GMTF can produce a spectrum of saleable products, including low Btu, synthesis and pipeline gases, hydrogen (for fuel cells or hydrogasification), methanol, gasoline, diesel and fuel oils, organic chemicals, and electrical power (potentially). In 1979 dollars, the base facility requires a $288 million capital investment for common-use units, $193 million for four gasification units and four synthesis units, and $305 million for six years of operation. Critical reviews of detailed vendor designs are appended for a methanol synthesis unit, three entrained flow gasifiers, a fluidized bed gasifier, and a hydrogasifier/slag-bath gasifier.

Ecological restoration and recovery in the wind-blown sand hazard areas of northern China: relationship between soil water and carrying capacity for vegetation in the Tengger Desert.

Science.gov (United States)

Li, XingRong; Zhang, ZhiShan; Tan, HuiJuan; Gao, YanHong; Liu, LiChao; Wang, XingPing

2014-05-01

The main prevention and control area for wind-blown sand hazards in northern China is about 320000 km(2) in size and includes sandlands to the east of the Helan Mountain and sandy deserts and desert-steppe transitional regions to the west of the Helan Mountain. Vegetation recovery and restoration is an important and effective approach for constraining wind-blown sand hazards in these areas. After more than 50 years of long-term ecological studies in the Shapotou region of the Tengger Desert, we found that revegetation changed the hydrological processes of the original sand dune system through the utilization and space-time redistribution of soil water. The spatiotemporal dynamics of soil water was significantly related to the dynamics of the replanted vegetation for a given regional precipitation condition. The long-term changes in hydrological processes in desert areas also drive replanted vegetation succession. The soil water carrying capacity of vegetation and the model for sand fixation by revegetation in aeolian desert areas where precipitation levels are less than 200 mm are also discussed.

Biomass Thermochemical Conversion Program. 1983 Annual report

Energy Technology Data Exchange (ETDEWEB)

Schiefelbein, G.F.; Stevens, D.J.; Gerber, M.A.

1984-08-01

Highlights of progress achieved in the program of thermochemical conversion of biomass into clean fuels during 1983 are summarized. Gasification research projects include: production of a medium-Btu gas without using purified oxygen at Battelle-Columbus Laboratories; high pressure (up to 500 psia) steam-oxygen gasification of biomass in a fluidized bed reactor at IGT; producing synthesis gas via catalytic gasification at PNL; indirect reactor heating methods at the Univ. of Missouri-Rolla and Texas Tech Univ.; improving the reliability, performance, and acceptability of small air-blown gasifiers at Univ. of Florida-Gainesville, Rocky Creek Farm Gasogens, and Cal Recovery Systems. Liquefaction projects include: determination of individual sequential pyrolysis mechanisms at SERI; research at SERI on a unique entrained, ablative fast pyrolysis reactor for supplying the heat fluxes required for fast pyrolysis; work at BNL on rapid pyrolysis of biomass in an atmosphere of methane to increase the yields of olefin and BTX products; research at the Georgia Inst. of Tech. on an entrained rapid pyrolysis reactor to produce higher yields of pyrolysis oil; research on an advanced concept to liquefy very concentrated biomass slurries in an integrated extruder/static mixer reactor at the Univ. of Arizona; and research at PNL on the characterization and upgrading of direct liquefaction oils including research to lower oxygen content and viscosity of the product. Combustion projects include: research on a directly fired wood combustor/gas turbine system at Aerospace Research Corp.; adaptation of Stirling engine external combustion systems to biomass fuels at United Stirling, Inc.; and theoretical modeling and experimental verification of biomass combustion behavior at JPL to increase biomass combustion efficiency and examine the effects of additives on combustion rates. 26 figures, 1 table.

A water blown urethane insulation for use in cryogenic environments

Science.gov (United States)

Blevins, Elana; Sharpe, Jon

1995-01-01

Thermal Protection Systems (TPS) of NASA's Space Shuttle External Tank include polyurethane and polyisocyanurate modified polyurethane foam insulations. These insulations, currently foamed with CFC 11 blowing agent, serve to maintain cryogenic propellant quality, maintain the external tank structural temperature limits, and minimize the formation of ice and frost that could potentially damage the ceramic insulation on the space shuttle orbiter. During flight the external tank insulations are exposed to mechanical, thermal and acoustical stresses. TPS must pass cryogenic flexure and substrate adhesion tests at -253 C, aerothermal and radiant heating tests at fluxes up to approximately 14 kilowatts per square meter, and thermal conductivity tests at cryogenic and elevated temperatures. Due to environmental concerns, the polyurethane insulation industry and the External Tank Project are tasked with replacing CFC 11. The flight qualification of foam insulations employing HCFC 141b as a foaming agent is currently in progress; HCFC 141b blown insulations are scheduled for production implementation in 1995. Realizing that the second generation HCFC blowing agents are an interim solution, the evaluation of third generation blowing agents with zero ozone depletion potential is underway. NASA's TPS Materials Research Laboratory is evaluating third generation blowing agents in cryogenic insulations for the External Tank; one option being investigated is the use of water as a foaming agent. A dimensionally stable insulation with low friability, good adhesion to cryogenic substrates, and acceptable thermal conductivity has been developed with low viscosity materials that are easily processed in molding applications. The development criteria, statistical experimental approach, and resulting foam properties will be presented.

Wake Measurement Downstream of a Hybrid Wing Body Model with Blown Flaps

Science.gov (United States)

Lin, John C.; Jones, Gregory S.; Allan, Brian G.; Westra, Bryan W.; Collins, Scott W.; Zeune, Cale H.

2010-01-01

Flow-field measurements were obtained in the wake of a full-span Hybrid Wing Body model with internally blown flaps. The test was performed at the NASA Langley 14 x 22 Foot Subsonic Tunnel at low speeds. Off-body measurements were obtained with a 7-hole probe rake survey system. Three model configurations were investigated. At 0deg angle of attack the surveys were completed with 0deg and 60deg flap deflections. At 10deg angle of attack the wake surveys were completed with a slat and a 60deg flap deflection. The 7-hole probe results further quantified two known swirling regions (downstream of the outboard flap edge and the inboard/outboard flap juncture) for the 60deg flap cases with blowing. Flowfield results and the general trends are very similar for the two blowing cases at nozzle pressure ratios of 1.37 and 1.56. High downwash velocities correlated with the enhanced lift for the 60deg flap cases with blowing. Jet-induced effects are the largest at the most inboard station for all (three) velocity components due in part to the larger inboard slot height. The experimental data are being used to improve computational tools for high-lift wings with integrated powered-lift technologies.

Fate of alkali and trace metals in biomass gasification

International Nuclear Information System (INIS)

Salo, K.; Mojtahedi, W.

1998-01-01

The fate of alkali metals (Na, K) and eleven toxic trace elements (Hg, Cd, Be, Se, Sb, As, Pb, Zn, Cr, Co, Ni) in biomass gasification have been extensively investigated in Finland in the past ten years. The former due to the gas turbine requirements and the latter to comply with environmental regulations. In this paper the results of several experimental studies to measure Na and K in the vapor phase after the gas cooler of a simplified (air-blown) Integrated Gasification Combined-Cycle (IGCC) system are reported. Also, trace element emissions from an IGCC plant using alfalfa as the feedstock are discussed and the concentration of a few toxic trace metals in the vapor phase in the gasifier product gas are reported. (author)

CFD-Modeling of the Multistage Gasifier Capacity of 30 KW

Science.gov (United States)

Levin, A. A.; Kozlov, A. N.; Svishchev, D. A.; Donskoy, I. G.

2017-11-01

Single-stage fuel gasification processes have been developed and widely studied in Russia and abroad throughout the 20th century. They are fundamental to the creation and design of modern gas generator equipment. Many studies have shown that single-stage gasification process, have already reached the limit of perfection, which was a significant improvement in their performance becomes impossible and unprofitable. The most fully meet modern technical requirements of multistage gasification technology. In the first step of the process, is organized allothermic biomass pyrolysis using heat of exhaust gas and generating power plant. At this stage, the yield of volatile products (gas and tar) of fuel. In the second step, the layer of fuel is, the tar is decomposed by the action of hot air and steam, steam-gas mixture is formed further reacts with the charcoal in the third process stage. The paper presents a model developed by the authors of the multi-stage gasifier for wood chips. The model is made with the use of CFD-modeling software package (COMSOL Multiphisics). To describe the kinetics of wood pyrolysis and gasification of charcoal studies were carried out using a set of simultaneous thermal analysis. For this complex developed original methods of interpretation of measurements, including methods of technical analysis of fuels and determine the parameters of the detailed kinetics and mechanism of pyrolysis.

The development of solid fuel gasification systems for cost-effective power generation with low environmental impacts

Energy Technology Data Exchange (ETDEWEB)

Nieminen, M; Kurkela, E; Staahlberg, P; Laatikainen-Luntama, J; Ranta, J; Hepola, J; Kangasmaa, K [VTT Energy, Espoo (Finland). Gasification and Advanced Combustion

1997-10-01

Relatively low carbon conversion is a disadvantage related to the air-blown fluidised-bed coal-biomass co-gasification process. Low carbon conversion is due to different reactivities and ash sintering behaviour of coal and biomass which leads to compromises in definition of gasification process conditions. In certain cases co-gasification may also lead to unexpected deposit formations or corrosion problems in downstream components especially when high alkali metal or chlorine containing biomass feedstocks are co-gasified with coal. During the reporting period, the work focused on co-gasification of coal and wood waste. The objectives of the present work were to find out the optimum conditions for improving the carbon conversion and to study the formation of different gas impurities. The results based on co-gasification tests with a pressurised fluidised-bed gasifies showed that in co-gasification even with only 15 % coal addition the heavy tar concentration was decreased significantly and, simultaneously, an almost total carbon conversion was achieved by optimising the gasification conditions. The study of filter fines recirculation and solid residues utilisation was started by characterizing filter dust. The work was carried out with an entrained-flow reactor in oxidising, inert and reducing gas conditions. The aim was to define the conditions required for achieving increased carbon conversion in different reactor conditions

Simulation of biomass and/or coal gasification systems integrated with fuel cells

Energy Technology Data Exchange (ETDEWEB)

Ersoz, A; Ozdogan, S; Caglayan, E; Olgun, H [TUBITAK Marmara Research Center, Kocaeli (Turkey). Institute of Energy

2006-11-15

This paper presents the results of a system simulation study. The HYSYS 3.1 - ASPEN code has been used for simulation. The system consists of a fixed bed gasifier followed by reforming and clean-up units. The produced hydrogen gas is fed to a PEM fuel cell. The gasified hydrocarbons are hazelnut shells, bark, rice straw, animal waste, and two lignites. Hydrocarbon properties, gasification, and reforming process parameters all affect the system efficiency. The effect of the moisture content and oxygen to carbon ratio of the hydrocarbon fees on the fuel processing and overall system efficiencies are presented. The overall efficiency of the system increases with increasing hydrocarbon fees oxygen to carbon ratio; this tendency is more evident at higher moisture levels.

Biomass gasifier projects for decentralized power supply in India: A financial evaluation

International Nuclear Information System (INIS)

Nouni, M.R.; Mullick, S.C.; Kandpal, T.C.

2007-01-01

Results of a techno-economic evaluation of biomass gasifier based projects for decentralized power supply for remote locations in India are presented. Contributions of different components of diesel engine generator (DG) sets, dual fuel (DF) engine generator sets and 100% producer gas (HPG) engine generator sets to their capital costs as well as to the levelized unit cost of electricity (LUCE) delivered by the same have been analyzed. LUCE delivered to the consumers has been estimated to be varying in the range of Rs. 13.14-24.49/kWh (US$ 0.30-0.55/kWh) for DF BGPP. LUCE increases significantly if BGPP is operated at part loads. Presently available 40kW capacity HPG systems in India are expected to be financially competitive with a DG set of equivalent capacity beyond a break-even diesel price of Rs. 34.70/l. It is expected to be financially more attractive than an equivalent capacity DF BGPP for diesel prices of more than Rs. 44.29/l. In certain specific conditions operating two smaller capacity systems has been found to be attractive as against a single larger capacity system

Development of a micro-turbine plant to run on gasifier producer gas

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-07-01

This report presents the results of a work programme to test a Capstone micro gas turbine using producer gas (1) in a test facility using synthetic producer gas at Advantca's research laboratories and (2) at the premises of Biomass Engineering Ltd where the micro gas turbine was coupled to an existing 80 kWe downdraft gasifier operating on clean wood and wood wastes. The initial tests at Advantica achieved successful operation of the Capstone micro gas turbine on 100% producer gas at a net electrical output of 5.5 kWe and with very low NOx emissions (<2 ppm). The micro turbine was then moved and recommissioned at a site belonging to Biomass Engineering where 350 hours of operation were achieved using producer gas and over 800 hours using natural gas. Problems were experienced during start-up due to limited access to control software and late delivery of the gas compressor for the micro turbine. Gas emissions and performance were deemed satisfactory. The report describes the test work at Advantica and at Biomass Engineering and discusses the technical and economic aspects of biomass gasification and micro turbine systems.

Economic analysis of a 20 kW gasifier; Analise economica de um gaseificador de 20 kW

Energy Technology Data Exchange (ETDEWEB)

Silva, Marcos Vinicius Miranda da; Rocha, Brigida Ramati Pereira da [Universidade Federal do Para (NEDS/UFPA), Belem, PA (Brazil). Nucleo de Energia para o Desenvolvimento Sustentavel], e-mail: neds@ufpa.br

2006-07-01

The gasification of biomass residues has been pointed as an alternative in electricity supplying for small communities of the Amazon region, because it promotes a significant substitution of the diesel oil in the electric power generation. This paper presents an economic analysis of an electricity generation system (gasifier and generator set) of 20 kw that is installed in the community of Jenipauba, in the State of Para. That analysis confirms the economic attractiveness of that energy alternative on the generator sets that operate exclusively with diesel oil. It also shows the impact of the labor law on electricity generation cost, as well as the need of subsidizing the electric power generation, because the community of Jenipauba is very poor. (author)

Mathematical Modeling of Ultra-Superheated Steam Gasification

Science.gov (United States)

Xin, Fen

Pure steam gasification has been of interest in hydrogen production, but with the challenge of supplying heat for endothermic reactions. Traditional solutions included either combusting feedstocks at the price of decreasing carbon conversion ratio, or using costly heating apparatus. Therefore, a distributed gasifier with an Ultra-Superheated-Steam (USS) generator was invented, satisfying the heat requirement and avoiding carbon combustion in steam gasification. This project developed the first version of the Ultra-Superheated-Steam-Fluidization-Model (USSFM V1.0) for the USS gasifier. A stand-alone equilibrium combustion model was firstly developed to calculate the USS mixture, which was the input to the USSFM V1.0. Model development of the USSFM V1.0 included assumptions, governing equations, boundary conditions, supporting equations and iterative schemes of guessed values. There were three nested loops in the dense bed and one loop in the freeboard. The USSFM V1.0 included one main routine and twenty-four subroutines. The USSFM V1.0 was validated with experimental data from the Enercon USS gasifier. The calculated USS mixture had a trace of oxygen, validating the initial expectation of creating an oxygen-free environment in the gasifier. Simulations showed that the USS mixture could satisfy the gasification heat requirement without partial carbon combustion. The USSFM V1.0 had good predictions on the H2% in all tests, and on other variables at a level of the lower oxygen feed. Provided with higher oxygen feed, the USSFM V1.0 simulated hotter temperatures, higher CO% and lower CO2%. Errors were explained by assumptions of equilibrium combustion, adiabatic reactors, reaction kinetics, etc. By investigating specific modeling data, gas-particle convective heat transfers were found to be critical in energy balance equations of both emulsion gas and particles, while bubble size controlled both the mass and energy balance equations of bubble gas. Parametric study

Increase of gastric area and weight gain in rats submitted to the ingestion of gasified water Aumento de área gástrica e ganho de peso em ratos submetidos à ingestão de água gaseificada

Directory of Open Access Journals (Sweden)

José Roberto Ferreira Santiago

2004-06-01

Full Text Available PURPOSE: Due to the progressive increasing in the use of gasified drinks and weight gain in the Brazilian population, in addition to the fact that carbonic gas is present in all soft drinks, an experimental study was conducted using rats as the subject to investigate the effects of gasified water in the hydric ingestion and food intake, weight gain, gastric area, blood sugar, hematocrit, and hemoglobin. METHODS: Four groups of 12 rats were studied for 36 days while receiving the following daily diet, four times per day: Group 1 - 35g/day of rat food "ad libitum" and 20ml of non-gasified water; Group 2 - 35g/day of rat food "ad libitum" and 20 ml of gasified water; Group 3 - 10g/day of rat food "ad libitum" and 20ml of non-gasified water; and Group 4 - 10g/day of rat food "ad libitum" and 20ml of gasified water. RESULTS: The results showed that the animals submitted to the treatment with gasified water (Groups 2 and 4, presented a larger volume of hydric ingestion and significant increase of the gastric area (pOBJETIVO: Em virtude do aumento progressivo da utilização de bebidas gaseificadas e do ganho de peso na população brasileira, e sabendo-se que os refrigerantes têm no gás carbônico um fator em comum, planejou-se um estudo experimental em ratos para investigar os efeitos da água gaseificada na ingestão hídrica e alimentar, ganho de peso, área gástrica, glicemia, hematócrito e hemoglobina. MÉTODOS: Foram constituídos 4 grupos de 12 ratos acompanhados por 36 dias. Ao Grupo-1 foi oferecido 35 g/dia de ração "ad libitum" e 20 ml de água não gaseificada em 4 períodos diários, ao Grupo-2 foi oferecido 35 g/dia de ração "ad libitum" e 20 ml de água gaseificada em 4 períodos diários, ao Grupo-3 foi oferecido 10 g/dia de ração "ad libitum" e 20 ml de água não gaseificada em 4 períodos diários e ao Grupo-4 foi oferecido 10 g/dia de ração "ad libitum" e 20 ml de água gaseificada em 4 períodos diários. RESULTADOS: Os

BIOMASS GASIFICATION AND POWER GENERATION USING ADVANCED GAS TURBINE SYSTEMS

Energy Technology Data Exchange (ETDEWEB)

David Liscinsky

2002-10-20

A multidisciplined team led by the United Technologies Research Center (UTRC) and consisting of Pratt & Whitney Power Systems (PWPS), the University of North Dakota Energy & Environmental Research Center (EERC), KraftWork Systems, Inc. (kWS), and the Connecticut Resource Recovery Authority (CRRA) has evaluated a variety of gasified biomass fuels, integrated into advanced gas turbine-based power systems. The team has concluded that a biomass integrated gasification combined-cycle (BIGCC) plant with an overall integrated system efficiency of 45% (HHV) at emission levels of less than half of New Source Performance Standards (NSPS) is technically and economically feasible. The higher process efficiency in itself reduces consumption of premium fuels currently used for power generation including those from foreign sources. In addition, the advanced gasification process can be used to generate fuels and chemicals, such as low-cost hydrogen and syngas for chemical synthesis, as well as baseload power. The conceptual design of the plant consists of an air-blown circulating fluidized-bed Advanced Transport Gasifier and a PWPS FT8 TwinPac{trademark} aeroderivative gas turbine operated in combined cycle to produce {approx}80 MWe. This system uses advanced technology commercial products in combination with components in advanced development or demonstration stages, thereby maximizing the opportunity for early implementation. The biofueled power system was found to have a levelized cost of electricity competitive with other new power system alternatives including larger scale natural gas combined cycles. The key elements are: (1) An Advanced Transport Gasifier (ATG) circulating fluid-bed gasifier having wide fuel flexibility and high gasification efficiency; (2) An FT8 TwinPac{trademark}-based combined cycle of approximately 80 MWe; (3) Sustainable biomass primary fuel source at low cost and potentially widespread availability-refuse-derived fuel (RDF); (4) An overall integrated

Gasification of Rice Husk in a Downdraft Gasifier: The Effect of Equivalence Ratio on the Gasification Performance, Properties, and Utilization Analysis of Byproducts of Char and Tar

Directory of Open Access Journals (Sweden)

Zhongqing Ma

2015-03-01

Full Text Available Rice husks (RH are a potential biomass source for bio-energy production in China, such as bio-gas production by gasification technology. In this paper, a bench-scale downdraft fixed bed gasifier (DFBG and a tar sampling system were designed. The effect of equivalence ratio (ER on gasification performance in terms of the temperature in the gasifier, the composition distribution of the producer gas, and the tar content in the producer gas was studied. The maximum lower heating value of 4.44 MJ/Nm3, minimum tar content of 1.34 g/Nm3, and maximum cold gas efficiency of 50.85% were obtained at ER of 0.211. In addition, the characteristics of gasification byproducts, namely bio-char and bio-tar, were analyzed. The proximate and ultimate analysis (especially of the alkali metal, the surface morphology, the surface area, and the pore size distribution of the rice husk char (RHC were obtained by the use of X-ray fluorescence (XRF and scanning electron microscopy (SEM, as well as by using the Brunauer-Emmett-Teller (BET method. The components of light tar and heavy tar were obtained by using gas chromatography-mass spectrometry (GC-MS.

Toxicological and chemical characterization of the process stream materials and gas combustion products of an experimental low-btu coal gasifier.

Science.gov (United States)

Benson, J M; Hanson, R L; Royer, R E; Clark, C R; Henderson, R F

1984-04-01

The process gas stream of an experimental pressurized McDowell-Wellman stirred-bed low-Btu coal gasifier, and combustion products of the clean gas were characterized as to their mutagenic properties and chemical composition. Samples of aerosol droplets condensed from the gas were obtained at selected positions along the process stream using a condenser train. Mutagenicity was assessed using the Ames Salmonella mammalian microsome mutagenicity assay (TA98, with and without rat liver S9). All materials required metabolic activation to be mutagenic. Droplets condensed from gas had a specific mutagenicity of 6.7 revertants/microgram (50,000 revertants/liter of raw gas). Methylnaphthalene, phenanthrene, chrysene, and nitrogen-containing compounds were positively identified in a highly mutagenic fraction of raw gas condensate. While gas cleanup by the humidifier-tar trap system and Venturi scrubber led to only a small reduction in specific mutagenicity of the cooled process stream material (4.1 revertants/microgram), a significant overall reduction in mutagenicity was achieved (to 2200 revertants/liter) due to a substantial reduction in the concentration of material in the gas. By the end of gas cleanup, gas condensates had no detectable mutagenic activity. Condensates of combustion product gas, which contained several polycyclic aromatic compounds, had a specific mutagenicity of 1.1 revertants/microgram (4.0 revertants/liter). Results indicate that the process stream material is potentially toxic and that care should be taken to limit exposure of workers to the condensed tars during gasifier maintenance and repair and to the aerosolized tars emitted in fugitive emissions. Health risks to the general population resulting from exposure to gas combustion products are expected to be minimal.

Bolivia: A Gasified Democracy

Directory of Open Access Journals (Sweden)

Willem Assies

2004-04-01

Full Text Available In October 2003 a wave of popular protest  brought down the Sánchez de Lozada government  in Bolivia. The intention to export natural gas to  the United States and Mexico triggered the protests, but actually stood for widespread discontent  with the Sánchez de Lozada government, the  preceding governments and the economic policies  pursued since 1985. The events belie the opinion  of various students of the Latin American democratic transitions who held that Bolivian democracy  was on its way towards consolidation and suggest that the recent inquiries into the quality of Latin  American democracies may point a way ahead in  rethinking democracy in the region. Taking such  assessments as a reference, this article reviews the  ‘gas war’ and looks at the Bolivian political regime as it has functioned over the past decades. It  will be argued that the ‘pacted democracy’, that  until now sustained institutionality, and the economic model adopted in 1985 have excluded an  important part of the population, both in political terms and where poverty alleviation and equity is  concerned. Increasing popular protest has been  met with increasing repression, which gradually  turned Bolivia into a ‘democradura’, or a ‘gasified  democracy’ that relies on teargas and bullets to  uphold itself. At present the country finds itself at  a crossroads. It either may reinvent democracy or  become an institutionalized ‘democradura’. Resumen: Bolivia: una democracia gasificadaEn octubre de 2003 una ola de protesta popular  llevó a la caída del gobierno de Sánchez de Lozada en Bolivia. La intención de exportar gas natural a los Estados Unidos y México gatilló dichas  protestas, aunque en realidad reflejaron un descontento general con el gobierno Sánchez de  Lozada, los gobiernos anteriores y las políticas  económicas implementadas desde 1985. Los  sucesos desmienten la opinión de varios analistas  de las

Enhanced model for integrated simulation of an entrained bed gasifier implemented as Aspen Hysys extension

Energy Technology Data Exchange (ETDEWEB)

Perez-Fortes, M; Bojarski, A; Ferrer-Nadal, S; Kopanos, G; Mitta, N; Pinilla, C A; Nougues, J M; Velo, E; Puigjaner, L [Universitat Politecnica de Catalunya, Barcelona (Spain). Dept. of Chemical Engineering-CEPIMA

2007-07-01

In this work an enhanced mathematical model of an entrained bed gasifier has been developed for improved synthesis gas production. The gasification model considers five stages: pyrolysis, volatiles combustion, char combustion, gasification and a final gas equilibrium zone. Mathematical simulations are carried out to help finding out feasible operating conditions of the process to achieve improved process performance. Visual Basic (VB) is tested as tool for modelling, by using the Aspen Hysys Extension (AHE) interface standards. This standard provides a suitable environment for this purpose, since it allows the creation of completely custom modules which are easy to plug and use thus facilitating the handling of complex models ready to interact with commercial simulation platforms. In this work, integration of different models is accomplished in Aspen Hysys (AH), which provides the basic connectivity within models components, and the thermodynamic framework needed. The integrated modules simulation environment platform uses data from ELCOGAS for validation purposes with excellent preliminary results. 9 refs., 2 figs.

Fluidised bed gasification of high-ash South African coals: An experimental and modelling study

CSIR Research Space (South Africa)

Engelbrecht, AS

2011-11-01

Full Text Available model (CeSFaMB). The predictive capability of the model was analysed in terms of the degree of variation between experimental and simulated results for each test. The calibrated model was used to design a 15 MW fluidised bed coal gasifier...-scale BFBG are given in Figure 1 and Table 1. Process description Coal, air, oxygen and steam are the input streams to the process which produce the output streams: gas and char (ash). Coal is fed to the gasifier by means of a screw conveyor at a...

Production of methanol/DME from biomass

Energy Technology Data Exchange (ETDEWEB)

Ahrenfeldt, J.; Birk Henriksen, U.; Muenster-Swendsen, J.; Fink, A.; Roengaard Clausen, L.; Munkholt Christensen, J.; Qin, K.; Lin, W.; Arendt Jensen, P.; Degn Jensen, A.

2011-07-01

In this project the production of DME/methanol from biomass has been investigated. Production of DME/methanol from biomass requires the use of a gasifier to transform the solid fuel to a synthesis gas (syngas) - this syngas can then be catalytically converted to DME/methanol. Two different gasifier types have been investigated in this project: 1) The Two-Stage Gasifier (Viking Gasifier), designed to produce a very clean gas to be used in a gas engine, has been connected to a lab-scale methanol plant, to prove that the gas from the gasifier could be used for methanol production with a minimum of gas cleaning. This was proved by experiments. Thermodynamic computer models of DME and methanol plants based on using the Two-Stage Gasification concept were created to show the potential of such plants. The models showed that the potential biomass to DME/methanol + net electricity energy efficiency was 51-58% (LHV). By using waste heat from the plants for district heating, the total energy efficiencies could reach 87-88% (LHV). 2) A lab-scale electrically heated entrained flow gasifier has been used to gasify wood and straw. Entrained flow gasifiers are today the preferred gasifier type for commercial coal gasification, but little information exists on using these types of gasifiers for biomass gasification. The experiments performed provided quantitative data on product and gas composition as a function of operation conditions. Biomass can be gasified with less oxygen consumption compared to coal. The organic fraction of the biomass that is not converted to gas appears as soot. Thermodynamic computer models of DME and methanol plants based on using entrained flow gasification were created to show the potential of such plants. These models showed that the potential torrefied biomass to DME/methanol + net electricity energy efficiency was 65-71% (LHV). Different routes to produce liquid transport fuels from biomass are possible. They include production of RME (rapeseed oil

Theoretical study on composition of gas produced by coal gasification; Sekitan gas ka de seiseisuru gas no sosei ni kansuru kosatsu (HYCOL data no doteki kaiseki)

Energy Technology Data Exchange (ETDEWEB)

Kaiho, M.; Yasuda, H.; Kobayashi, M.; Yamada, O.; Soneda, Y.; Makino, M. [National Institute for Resources and Environment, Tsukuba (Japan)

1996-10-28

In relation to considerations on composition of gas produced by coal gasification, the HYCOL hydrogen generation process data were analyzed. From the fact that CO concentration (Y) decreases linearly with CO2 concentration (X), element balance of gasification of reacted coal was used to introduce a reaction analysis equation. The equation includes a term of oxygen excess {Delta}(amount of oxygen consumed for combustion of CO and H2 in excess of the theoretical amount), derived by subtracting the stoichiometric oxygen amount used to gasify coal into CO and H2 from the consumed oxygen amount. The {Delta} can be used as a reference to oxygen utilization efficiency. An equation for the {Delta} was introduced. Also introduced was a term for steam decomposition amount derived by subtracting the generated steam from the supplied steam. These terms may be used as a clue to permeate into the gasifying reaction process. This suggestion was discussed by applying the terms to gas composition value during operation. According to the HYCOL analysis, when a gasification furnace is operated at higher than the reference oxygen amount, coal supply variation is directly reflected to the combustion reaction, making the {Delta} distribution larger. In an inverse case, unreacted carbon remains in the furnace due to oxygen shortage, and shift reaction may occur more easily even if oxygen/coal supply ratio varies. 6 figs., 1 ref.

Gasification of algal biomass (Cladophora glomerata L.) with CO2/H2O/O2 in a circulating fluidized bed.

Science.gov (United States)

Ebadi, Abdol Ghaffar; Hisoriev, Hikmat

2017-11-28

Gasification is one of the most important thermochemical routes to produce both synthesis gas (syngas) and chars. The quality of produced syngas wieldy depends on the operating conditions (temperature, residence time, heating rate, and gasifying agent), hydrodynamic properties of gasifier (particle size, minimum fluidization velocity, and gasifier size), and type of feedstock (coal, biomass, oil, and municipal solid wastes). In the present study, simulation of syngas production via circulating fluidized bed (CFB) gasification of algal biomass (Cladophora glomerata L.) at different gasifying agents and particle sizes was carried out, using Aspen Plus simulator. The model which has been validated by using experimental data of the technical literature was used to evaluate the influence of operating conditions on gas composition and performance parameters. The results show that biomass gasification using pure oxygen as the gasification agent has great potential to improve the caloric value of produced gas and performance indicators. It was also found that the produced gas caloric value, syngas yield, and performance parameters (CCE and CGE) increase with reaction temperature but are inversely proportional to the biomass particle size.

Process integration and optimization of a solid oxide fuel cell – Gas turbine hybrid cycle fueled with hydrothermally gasified waste biomass

International Nuclear Information System (INIS)

Facchinetti, Emanuele; Gassner, Martin; D’Amelio, Matilde; Marechal, François; Favrat, Daniel

2012-01-01

Due to its suitability for using wet biomass, hydrothermal gasification is a promising process for the valorization of otherwise unused waste biomass to synthesis gas and biofuels. Solid oxide fuel cell (SOFC) based hybrid cycles are considered as the best candidate for a more efficient and clean conversion of (bio) fuels. A significant potential for the integration of the two technologies is expected since hydrothermal gasification requires heat at 673–773 K, whereas SOFC is characterized by heat excess at high temperature due to the limited electrochemical fuel conversion. This work presents a systematic process integration and optimization of a SOFC-gas turbine (GT) hybrid cycle fueled with hydrothermally gasified waste biomass. Several design options are systematically developed and compared through a thermodynamic optimization approach based on First Law and exergy analysis. The work demonstrates the considerable potential of the system that allows for converting wet waste biomass into electricity at a First Law efficiency of up to 63%, while simultaneously enabling the separation of biogenic carbon dioxide for further use or sequestration. -- Highlights: ► Hydrothermal gasification is a promising process for the valorization of waste wet biomass. ► Solid Oxide Fuel Cell – Gas Turbine hybrid cycle emerges as the best candidates for conversion of biofuels. ► A systematic process integration and optimization of a SOFC-GT hybrid cycle fuelled with hydrothermally gasified biomass is presented. ► The system may convert wet waste biomass to electricity at a First Law efficiency of 63% while separating the biogenic carbon dioxide. ► The process integration enables to improve the First Law efficiency of around 4% with respect to a non-integrated system.

Methodology for sizing, energy analysis and selection of equipment for a biomass gasifier to drive an internal combustion engine; Metodologia de dimensionamento, analise energetica e selecao de equipamentos de um gaseificador de biomassa para o acionamento de um motor de combustao interna

Energy Technology Data Exchange (ETDEWEB)

Coronado, Christian Rodriguez; Silveira, Jose Luz [Universidade Estadual Paulista (FEG/UNESP), Guaratingueta, SP (Brazil). Fac. de Engenharia], e-mails: christian@feg.unesp.br, joseluz@feg.unesp.br; Arauzo, Jesus Perez [University of Zaragoza (UNIZAR), Zaragoza (Spain). Centro Politecnico Superior. Chemical and Environmental Engineering Dept.], e-mail: qtarauzo@unizar.es

2006-07-01

Alter both oil crisis, of 1973 and 1979, a bad effect of the elevated costs and continuously increment of the oil prices was noted, for this reason, the interest for renewable energies sources widely available in developing countries was increased. All over the world, governments have formulated main objectives for energies savings and search for friendly technologies, taking into account the effects related with the environment. The imminent scarcity of fossil fuels has made humanity the rational use of primary energies, as a result of these; new plants with improved technology have been conceived taking into account energy savings and efficiency improvement. In this context, biomass gasification technologies are important, since they consist in techniques of parallel production of electricity and heat from just one fuel. This work consists in the development of a gasifier down draft of 100 kW for an internal combustion engine, which includes its sizing process and its energy analysis. The sizing includes design facts and the parameters of the conditioning systems for the exhaust gas. This part is mainly based in the experience of a work group of the Zaragoza State University - Spain, UNIZAR, specialists in the construction of small down draft gasifiers, for every case, air will be used as a gasifier agent and as biomass forestall. The availability of biomass resources and the application of the national energetic view system are relevant. The gasifier will have a 100 kg/h of feeding, the energetic analysis includes the matter and energy balance and the respective efficient such cold as hot efficient of the exhaust gas. Moreover it will be tried the equipment recommended for the cleaning and conditioning of this gas fuel for this equipment in particular. (author)

Multi-gene genetic programming based predictive models for municipal solid waste gasification in a fluidized bed gasifier.

Science.gov (United States)

Pandey, Daya Shankar; Pan, Indranil; Das, Saptarshi; Leahy, James J; Kwapinski, Witold

2015-03-01

A multi-gene genetic programming technique is proposed as a new method to predict syngas yield production and the lower heating value for municipal solid waste gasification in a fluidized bed gasifier. The study shows that the predicted outputs of the municipal solid waste gasification process are in good agreement with the experimental dataset and also generalise well to validation (untrained) data. Published experimental datasets are used for model training and validation purposes. The results show the effectiveness of the genetic programming technique for solving complex nonlinear regression problems. The multi-gene genetic programming are also compared with a single-gene genetic programming model to show the relative merits and demerits of the technique. This study demonstrates that the genetic programming based data-driven modelling strategy can be a good candidate for developing models for other types of fuels as well. Copyright © 2014 Elsevier Ltd. All rights reserved.

Mathematical modeling of a fluidized bed gasifier for steam gasification of coal using high-temperature nuclear reactor heat

International Nuclear Information System (INIS)

Kubiak, H.; vanHeek, K.-H.; Juntgen, H.

1986-01-01

Coal gasification is a well-known technique and has already been developed and used since a long time. In the last few years, forced by the energy situation, new efforts have been made to improve known processes and to start new developments. Conventional gasification processes use coal not only as feedstock to be gasified but also for supply of energy for reaction heat, steam production, and other purposes. With a nuclear high temperature reactor (HTR) as a source for process heat, it is possible to transform the whole of the feed coal into gas. This concept offers advantages over existing gasification processes: saving of coal, as more gas can be produced from coal; less emission of pollutants, as the HTR is used for the production of steam and electricity instead of a coal-fired boiler; and lower production costs for the gas

Thermodynamic assessment of IGCC power plants with hot fuel gas desulfurization

International Nuclear Information System (INIS)

Giuffrida, Antonio; Romano, Matteo C.; Lozza, Giovanni G.

2010-01-01

In IGCC power plants, hot gas desulfurization (HGD) represents an attractive solution to simplify syngas treatments and to improve the efficiency, potentially reducing the final cost of electricity. In the present study, the various consequences of the introduction of a HGD station in the power plant are discussed and evaluated, in comparison with conventional near-ambient temperature clean-up. Attention is paid to the potential improvements of the overall energy balance of the complete power station, along with the requirements of the sorbent regeneration process, to the influence of the desulfurization temperature and to the different solutions needed to control the NO x emissions (altered by the presence of HGD). The net performance of complete IGCC power plants (with HGD or with conventional desulfurization) were predicted, with reference to status-of-the-art solutions based on an entrained flow, dry-feed, oxygen-blown gasifier and on an advanced, FB-class combined cycle. The net efficiency experiences about 2.5% point improvement with HGD, even if a small reduction in the power output was predicted, when using the same combustion turbine. An exhaustive sensitivity analysis was carried out to evaluate the effects of different working conditions at the HGD station, e.g. desulfurization temperature and oxygen content in the gaseous stream for sorbent regeneration. According to the obtained results, these parameters have a weak influence on the efficiency. In particular, a very elevated desulfurization temperature (above 400-500 o C) does not provide decisive thermodynamic advantages. Therefore, the HGD unit optimization can be driven by technical and economical aspects and by emission abatement requirements. For instance, utilization of nitrogen for HGD sorbent regeneration (rather than for syngas dilution) and higher fuel temperature may improve the NO formation. Hence, different strategies to achieve acceptable NO x emissions (e.g. steam dilution) and their

Medline Plus

Full Text Available ... between the respiratory system and the bloodstream. Oxygen molecules attach to red blood cells, which travel back ... heart. At the same time, the carbon dioxide molecules in the alveoli are blown out of the ...

Enriched-air fluidized bed gasification using bench and pilot scale reactors of dairy manure with sand bedding based on response surface methods

International Nuclear Information System (INIS)

Nam, Hyungseok; Maglinao, Amado L.; Capareda, Sergio C.; Rodriguez-Alejandro, David Aaron

2016-01-01

Enriched-air gasification was performed in fluidized bed reactors using the processed dairy manure which was mixed with sand bedding. The effects of temperature, modified equivalence ratio (ER_m), and oxygen concentration on the gas products were investigated based on the statistical models using a bench-scale reactor in order to obtain empirical correlations. Then, the empirical equations were applied to compare the produced gases from a pilot-scale fluidized bed gasifier. The empirical and actual H_2 and CH_4 compositions were within a 10% error, while the sum of produced CO and CO_2 gases showed similar composition within 3% error. The most influential factors for the syngas heating value were temperature followed by the oxygen concentration and ER (equivalence ratio). The composition of H_2 (2.1–11.5%) and CO (5.9–20.3%) rose with an increase in temperature and oxygen concentration. The variation of CO_2 (16.8–31.6%) was mainly affected by the degree of oxygen concentration in the gasifying agent. The ranges of the LHV (lower heating value), carbon conversion efficiency and cold gas efficiency were discussed. An economic review showed favorable indications for on-site dairy manure gasification process for electric power based on the depreciable payback period and the power production costs. - Highlights: • Sand mixed dairy manure obtained directly from a dairy farm was processed and used. • Response surface methodology was used to investigate the enriched-air gasification. • Syngas results from bench and pilot scale gasifiers were compared and reviewed. • A highest LVH of 8 MJ/Nm"3 was obtained from the enriched-air gasification. • The power production costs were determined to be $0.053/kWh

Air gasification of agricultural waste in a fluidized bed gasifier: hydrogen production performance

Energy Technology Data Exchange (ETDEWEB)

Wan Ab Karim Ghani, W. A.; Moghadam, R. A.; Mohd Salleh, M. A. [Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Alias, A. B. [Chemical Engineering, Universiti Teknologi MARA Malaysia, 54500 Shah Alam, Selangor (Malaysia)

2009-07-01

Recently, hydrogen production from biomass has become an attractive technology for power generation. The main objective pursued in this work is to investigate the hydrogen production potential from agricultural wastes (coconut coir and palm kernel shell) by applying the air gasification technique. An experimental study was conducted using a bench-scale fluidized bed gasifier with 60 mm diameter and 425 mm height. During the experiments, the fuel properties and the effects of operating parameters such as gasification temperatures (700 to 900 {sup o}C), fluidization ratio (2 to 3.33 m/s), static bed height (10 to 30 mm) and equivalence ratio (0.16 to 0.46) were studied. It was concluded that substantial amounts of hydrogen gas (up to 67 mol%) could be produced utilizing agricultural residues such as coconut and palm kernel shell by applying this fluidization technique. For both samples, the rise of temperature till 900 {sup o}C favored further hydrocarbon reactions and allowed an increase of almost 67 mol% in the release of hydrogen. However, other parameters such as fluidising velocity and feed load showed only minor effects on hydrogen yield. In conclusion, agricultural waste can be assumed as an alternative renewable energy source to the fossil fuels, and the environmental pollution originating from the disposal of agricultural residues can be partially reduced. (author)

Air Gasification of Agricultural Waste in a Fluidized Bed Gasifier: Hydrogen Production Performance

Directory of Open Access Journals (Sweden)

A. B. Alias

2009-05-01

Full Text Available Recently, hydrogen production from biomass has become an attractive technology for power generation. The main objective pursued in this work is to investigate the hydrogen production potential from agricultural wastes (coconut coir and palm kernel shell by applying the air gasification technique. An experimental study was conducted using a bench-scale fluidized bed gasifier with 60 mm diameter and 425 mm height. During the experiments, the fuel properties and the effects of operating parameters such as gasification temperatures (700 to 900°C, fluidization ratio (2 to 3.33 m/s, static bed height (10 to 30 mm and equivalence ratio (0.16 to 0.46 were studied. It was concluded that substantial amounts of hydrogen gas (up to 67 mol% could be produced utilizing agricultural residues such as coconut and palm kernel shell by applying this fluidization technique. For both samples, the rise of temperature till 900°C favored further hydrocarbon reactions and allowed an increase of almost 67 mol% in the release of hydrogen. However, other parameters such as fluidizing velocity and feed load showed only minor effects on hydrogen yield. In conclusion, agricultural waste can be assumed as an alternative renewable energy source to the fossil fuels, and the environmental pollution originating from the disposal of agricultural residues can be partially reduced.

Experimental study on two-stage air supply downdraft gasifier and dual fuel engine system

Energy Technology Data Exchange (ETDEWEB)

Nhuchhen, Daya Ram; Salam, P.A. [Asian Institute of Technology, Energy Field of Study, School of Environment Resource and Development, P. O. Box 4, Klong Luang, Pathumthani (Thailand)

2012-06-15

Biomass is a widely used renewable energy resource with net balanced carbon dioxide absorptions and emissions. An inefficient use of solid biomass in combustion process emits more gaseous pollutants, increasing the pollution level. Biomass gasification is one of the techniques to support efficient use of biomass. Multistage gasification is a method of gasification to improve quality of the producer gas in which two separate reactors are designed for separating gasification reactions. This study presents experimental results of gasification using Eucalyptus wood in a single long cylindrical reactor with two air supply ports, i.e., primary and secondary. The effect of different air supply rates on the heating values of the producer gas was studied. Optimum primary and secondary air supply rate of 100 and 80 l/min at equivalence ratio of 0.38 was observed with producer gas lower heating value of 4.72 MJ Nm{sup -3}. The performance of a diesel engine in the dual fuel mode was also evaluated. The overall gasifier engine system efficiency was 13.86 % at an electrical load of 10.54 kW{sub e} with specific energy consumption of 16.22 MJ kWh{sup -1}. The heat recovery system was designed and tested to recover heat from producer gas in the form of hot water. (orig.)

Producer gas production of Indonesian biomass in fixed-bed downdraft gasifier as an alternative fuels for internal combustion engines

Science.gov (United States)

Simanjuntak, J. P.; Lisyanto; Daryanto, E.; Tambunan, B. H.

2018-03-01

downdraft biomass gasification reactors, coupled with reciprocating internal combustion engines (ICE) are a viable technology for small scale heat and power generation. The direct use of producer gas as fuel subtitution in an ICE could be of great interest since Indonesia has significant land area in different forest types that could be used to produce bioenergy and convert forest materials to bioenergy for use in energy production and the versatility of this engine. This paper will look into the aspect of biomass energie as a contributor to energy mix in Indonesia. This work also contains information gathered from numerous previews study on the downdraft gasifier based on experimental or simulation study on the ability of producer gas as fuels for internal combustion engines aplication. All data will be used to complement the preliminary work on biomass gasification using downdraft to produce producer gas and its application to engines.

From coal to biomass gasification: Comparison of thermodynamic efficiency

International Nuclear Information System (INIS)

Prins, Mark J.; Ptasinski, Krzysztof J.; Janssen, Frans J.J.G.

2007-01-01

The effect of fuel composition on the thermodynamic efficiency of gasifiers and gasification systems is studied. A chemical equilibrium model is used to describe the gasifier. It is shown that the equilibrium model presents the highest gasification efficiency that can be possibly attained for a given fuel. Gasification of fuels with varying composition of organic matter, in terms of O/C and H/C ratio as illustrated in a Van Krevelen diagram, is compared. It was found that exergy losses in gasifying wood (O/C ratio around 0.6) are larger than those for coal (O/C ratio around 0.2). At a gasification temperature of 927 deg. C, a fuel with O/C ratio below 0.4 is recommended, which corresponds to a lower heating value above 23 MJ/kg. For gasification at 1227 deg. C, a fuel with O/C ratio below 0.3 and lower heating value above 26 MJ/kg is preferred. It could thus be attractive to modify the properties of highly oxygenated biofuels prior to gasification, e.g. by separation of wood into its components and gasification of the lignin component, thermal pre-treatment, and/or mixing with coal in order to enhance the heating value of the gasifier fuel

Wabash River Coal Gasification Repowering Project: A DOE Assessment; FINAL

International Nuclear Information System (INIS)

National Energy Technology Laboratory

2002-01-01

The goal of the U.S. Department of Energy (DOE) Clean Coal Technology Program (CCT) is to furnish the energy marketplace with a number of advanced, more efficient, and environmentally responsible coal utilization technologies through demonstration projects. These projects seek to establish the commercial feasibility of the most promising advanced coal technologies that have developed beyond the proof-of-concept stage. This document serves as a DOE post-project assessment (PPA) of a project selected in CCT Round IV, the Wabash River Coal Gasification Repowering (WRCGR) Project, as described in a Report to Congress (U.S. Department of Energy 1992). Repowering consists of replacing an existing coal-fired boiler with one or more clean coal technologies to achieve significantly improved environmental performance. The desire to demonstrate utility repowering with a two-stage, pressurized, oxygen-blown, entrained-flow, integrated gasification combined-cycle (IGCC) system prompted Destec Energy, Inc., and PSI Energy, Inc., to form a joint venture and submit a proposal for this project. In July 1992, the Wabash River Coal Gasification Repowering Project Joint Venture (WRCGRPJV, the Participant) entered into a cooperative agreement with DOE to conduct this project. The project was sited at PSI Energy's Wabash River Generating Station, located in West Terre Haute, Indiana. The purpose of this CCT project was to demonstrate IGCC repowering using a Destec gasifier and to assess long-term reliability, availability, and maintainability of the system at a fully commercial scale. DOE provided 50 percent of the total project funding (for capital and operating costs during the demonstration period) of$438 million

Experience of more than 1000 h of operation with oxygen carriers and solid biomass at large scale

International Nuclear Information System (INIS)

Berdugo Vilches, Teresa; Lind, Fredrik; Rydén, Magnus; Thunman, Henrik

2017-01-01

Highlights: • First large scale experience (MW) of biomass combustion at CLC-relevant conditions. • Manganese and ilmenite were applied successfully at semi-industrial scale. • 60% combustion under challenging conditions: 830 °C, over-bed fuel feeding. • Volatiles conversion limited by mixing to a significant extent. - Abstract: This paper presents an overview of the experience gained from operating a dual fluidized bed system with oxygen carriers and biomass for more than 1000 h. The tests were carried out in the Chalmers boiler/gasifier loop (with inputs of 12 MW_t_h and 2–4 MW_t_h, respectively), which is 2–4 orders of magnitude larger than most existing CLC units. Coarse biomass particles (i.e., commercial wood pellets) were fed as fuel onto the surface of a mild fluidized bed. This limits significantly the contacts between the volatiles and the oxygen carrier particles, as the flotsam fuel tends to remain on the surface of the bed while the volatiles are released. The oxygen carrier materials tested were ilmenite and a manganese ore. The influences on biomass conversion of fluidization velocity, fuel feeding rate, and circulation rate of the bed material were investigated. Both bed materials efficiently transported oxygen between the reactors, achieving up to 60% combustion of the gases released in the reactor at a relatively low temperature, i.e., 830 °C. The ilmenite outperformed the manganese ore under the conditions investigated. With oxygen carriers, the yield of hydrocarbons heavier than benzene was in the range of 10–11 g/N m"3, which was 70% (w/w) lower than that obtained in a reference case with silica-sand as the bed material. The conversion of volatile species to CO_2 was limited by gas-solids mixing, which could be enhanced by altering the fluidization velocity. The circulation rate of the bed material and the fuel feeding rate were found to have important influences on the rate of char gasification. Given the relatively low

Conditions for testing the corrosion rates of ceramics in coal gasification systems

Energy Technology Data Exchange (ETDEWEB)

Hurley, J.P.; Nowok, J.W. [Univ. of North Dakota, Grand Forks, ND (United States)

1996-08-01

Coal gasifier operating conditions and gas and ash compositions affect the corrosion rates of ceramics used for construction in three ways: (1) through direct corrosion of the materials, (2) by affecting the concentration and chemical form of the primary corrodents, and (3) by affecting the mass transport rate of the primary corrodents. To perform an accurate corrosion test on a system material, the researcher must include all relevant corrodents and simulate conditions in the gasifier as closely as possible. In this paper, the authors present suggestions for conditions to be used in such corrosion tests. Two main types of corrosion conditions are discussed: those existing in hot-gas cleanup systems where vapor and dry ash may contribute to corrosion and those experienced by high-temperature heat exchangers and refractories where the main corrodent will be coal ash slag. Only the fluidized-bed gasification systems such as the Sierra Pacific Power Company Pinon Pine Power Project system are proposing the use of ceramic filters for particulate cleanup. The gasifier is an air-blown 102-MWe unit employing a Westinghouse{trademark} ceramic particle filter system operating at as high as 1100{degrees}F at 300 psia. Expected gas compositions in the filter will be approximately 25% CO, 15% H{sub 2}, 5% CO{sub 2}, 5% H{sub 2}O, and 50% N{sub 2}. Vapor-phase sodium chloride concentrations are expected to be 10 to 100 times the levels in combustion systems at similar temperatures, but in general the concentrations of the minor primary and secondary corrodents are not well understood. Slag corrosiveness will depend on its composition as well as viscosity. For a laboratory test, the slag must be in a thermodynamically stable form before the beginning of the corrosion test to assure that no inappropriate reactions are allowed to occur. Ideally, the slag would be flowing, and the appropriate atmosphere must be used to assure realistic slag viscosity.

Pinon Pine power project nears start-up

Energy Technology Data Exchange (ETDEWEB)

Tatar, G.A. [Sierra Pacific Power Co., Reno, NV (United States); Gonzalez, M. [Foster Wheeler USA Corp., Clinton, NJ (United States); Mathur, G.K. [M.W. Kellogg Co., Houston, TX (United States)

1997-12-31

The IGCC facility being built by Sierra Pacific Power Company (SPPCo) at their Tracy Station in Nevada is one of three IGCC facilities being cost-shared by the US Department of Energy (DOE) under their Clean Coal Technology Program. The specific technology to be demonstrated in SPPCo`s Round Four Project, known as the Pinon Pine IGCC Project, includes the KRW air blown pressurized fluidized bed gasification process with hot gas cleanup coupled with a combined cycle facility based on a new GE 6FA gas turbine. Construction of the 100 MW IGCC facility began in February 1995 and the first firing of the gas turbine occurred as scheduled on August 15, 1996 with natural gas. Mechanical completion of the gasifier and other outstanding work is due in January 1997. Following the startup of the plant, the project will enter a 42 month operating and testing period during which low sulfur western and high sulfur eastern or midwestern coals will be processed.

Preparation and Characterization of Polypropylene Non-woven Fabrics Prepared by Melt-blown Spinning for Filtration Membranes

Energy Technology Data Exchange (ETDEWEB)

Chu, Konghee; Park, Mira; Kim, Hakyong [Chonbuk National Univ., Jeonju (Korea, Republic of); Jin, Fanlong; Park, Soojin [Inha Univ., Incheon (Korea, Republic of)

2014-06-15

PP non-woven fabrics were prepared by melt-blown spinning, followed by heat and plasma treatments. After heat treatment, the PP non-woven fabrics displayed decreased water flux, increased tensile strength, decreased elongation, and an average pore size of 0.7 μm. The hydrophilicity of the PP non-woven fabrics was improved by plasma treatment. The water flux of the PP non-woven fabrics increased about two fold after the plasma treatment. The particle removal efficiency was determined to be 97.2-99.4% for 1-3 μm sized particles, demonstrating a high particle removal efficiency. Polypropylene (PP) non-woven fabrics have been widely used as filtration membranes in wastewater purification with industrial applications due to their low cost, good mechanical strength, and high thermal and chemical stability. The membrane fouling behavior depends strongly on the physical and mechanical properties of the membrane, including pore size, porosity, morphology, and hydrophilicity. In general, PP non-woven fabrics have poor hydrophilicity; this has limited their application in the biomedical field. It is therefore necessary to develop PP non-woven fabrics with improved surface hydrophilicity to increase the scope of their use. Plasma treatment, an environmentally friendly alternative to traditional chemical activation, only changes the uppermost atomic layers of a membrane surface without affecting the bulk properties of the polymer.

Correction of Dynamic Characteristics of SAR Cryogenic GTE on Consumption of Gasified Fuel

Science.gov (United States)

Bukin, V. A.; Gimadiev, A. G.; Gangisetty, G.

2018-01-01

When the gas turbine engines (GTE) NK-88 were developed for liquid hydrogen and NK-89 for liquefied natural gas, performance of the systems with a turbo-pump unitary was improved and its proved without direct regulation of the flow of a cryogenic fuel, which was supplied by a centrifugal pump of the turbo-pump unit (TPU) Command from the “kerosene” system. Such type of the automatic control system (SAR) has the property of partial “neutralization” of the delay caused by gasification of the fuel. This does not require any measurements in the cryogenic medium, and the failure of the centrifugal cryogenic pump does not lead to engine failure. On the other hand, the system without direct regulation of the flow of cryogenic fuel has complex internal dynamic connections, their properties are determined by the characteristics of the incoming units and assemblies, and it is difficult to maintain accurate the maximum boundary level and minimum fuel consumption due to the influence of a booster pressure change. Direct regulation of the consumption of cryogenic fuel (prior to its gasification) is the preferred solution, since for using traditional liquid and gaseous fuels this is the main and proven method. The scheme of correction of dynamic characteristics of a single-loop SAR GTE for the consumption of a liquefied cryogenic fuel with a flow rate correction in its gasified state, which ensures the dynamic properties of the system is not worse than for NK-88 and NK-89 engines.

Fuel conversion efficiency and energy balance of a 400 kW{sub t} fluidized bed straw gasifier

Energy Technology Data Exchange (ETDEWEB)

Erguedenler, A.; Ghaly, A.E.; Hamdullahpur, F. [Technical Univ. of Nova Scotia, Halifax (Canada)

1993-12-31

A 400 kW (thermal) dual-distributor type fluidized bed gasifier developed for the energy recovery from cereal straw was used to investigate the effects of equivalence ratio (actual air-fuel ratio: stoichiometric air-fuel ratio), fluidization velocity and bed height on the fuel conversion efficiency from wheat straw. The energy balance was also performed on the system under those operating conditions. The results indicated that the equivalence ratio was the most significant parameter affecting the fuel conversion efficiency and the energy recovered from the straw in the form of gas. Both the fuel conversion efficiency and the energy recovery increased with increases in the equivalence ratio. The fluidization velocity and bed height had minimal effects on these parameters. A fuel conversion efficiency as high as 98% was obtained at the equivalence ratio of 0.35. The energy recovered in the form of gas and the sensible heat of the produced gas were in the ranges of 40--70% and 9--17%, respectively. Unaccounted losses showed a dramatic increase at lower equivalence ratios and were in the range of 6--53% depending on the operating condition.

Biomass CFB gasifier connected to a 350 MW{sub t}h steam boiler fired with coal and natural gas - THERMIE demonstration project in Lahti in Finland

Energy Technology Data Exchange (ETDEWEB)

Palonen, J. [Foster Wheeler Energia Oy, Varkaus (Finland). Varkaus Global New Products

1997-12-31

The successful experience in developing the advanced Foster Wheeler Energi Oy`s (former Ahlstroem Pyropower) Circulating Fluidized Bed combustion system subsequently led to the development of the CFB gasification technology in the early 1980s. The driving force for the developing work was the dramatic increase in oil price during the oil crises. The primary advantage of CFB gasification technology is that the it enables the substitution of expensive fuels e.g. oil or gas with cheap solid fuels. These cheap fuels are typically different types of waste woods, bark or other biofuels. In the CFB gasifier these solid fuels are converted to gaseous fuel which can be used instead of other expensive fuels. In some cases this also solves a waste disposal problem, providing a secondary economic and environmental benefit. Foster Wheeler Energia Oy has supplied four commercial scale atmospheric CFB gasifiers in the mid 80s to the pulp and paper industry with capacities from 17 to 35 MW based on fuel input. These applications utilize waste wood as feedstock and the units are still successfully operation today. Lahden Laempoevoima Oy is a Finnish power company producing power and district heat for the city of Lahti. The company is 50 % owned by the city of Lahti and 50 % by Imatran Voima Oy, which is the largest utility power company in Finland. Lahden Laempoevoima Oy operates the Kymijaervi power plant locating nearby the city of Lahti in Southern Finland. To keep the energy prices as low as possible, Lahden Laempoevoima is continuously looking for the most economical fuel sources, and simultaneously, trying to improve the environmental acceptability of the energy production. At the moment, about 300 GWh/a different type of biofuels and refuse fuels are available in the Lahti area. On an annual basis, the available amount of biofuels and refuse fuels is enough to substitute for about 15 % of the fuels burned in the main boiler equalling max 30 % of coal. The aim in this Lahden

Biomass CFB gasifier connected to a 350 MW{sub t}h steam boiler fired with coal and natural gas - THERMIE demonstration project in Lahti in Finland

Energy Technology Data Exchange (ETDEWEB)

Palonen, J [Foster Wheeler Energia Oy, Varkaus (Finland). Varkaus Global New Products

1998-12-31

The successful experience in developing the advanced Foster Wheeler Energi Oy`s (former Ahlstroem Pyropower) Circulating Fluidized Bed combustion system subsequently led to the development of the CFB gasification technology in the early 1980s. The driving force for the developing work was the dramatic increase in oil price during the oil crises. The primary advantage of CFB gasification technology is that the it enables the substitution of expensive fuels e.g. oil or gas with cheap solid fuels. These cheap fuels are typically different types of waste woods, bark or other biofuels. In the CFB gasifier these solid fuels are converted to gaseous fuel which can be used instead of other expensive fuels. In some cases this also solves a waste disposal problem, providing a secondary economic and environmental benefit. Foster Wheeler Energia Oy has supplied four commercial scale atmospheric CFB gasifiers in the mid 80s to the pulp and paper industry with capacities from 17 to 35 MW based on fuel input. These applications utilize waste wood as feedstock and the units are still successfully operation today. Lahden Laempoevoima Oy is a Finnish power company producing power and district heat for the city of Lahti. The company is 50 % owned by the city of Lahti and 50 % by Imatran Voima Oy, which is the largest utility power company in Finland. Lahden Laempoevoima Oy operates the Kymijaervi power plant locating nearby the city of Lahti in Southern Finland. To keep the energy prices as low as possible, Lahden Laempoevoima is continuously looking for the most economical fuel sources, and simultaneously, trying to improve the environmental acceptability of the energy production. At the moment, about 300 GWh/a different type of biofuels and refuse fuels are available in the Lahti area. On an annual basis, the available amount of biofuels and refuse fuels is enough to substitute for about 15 % of the fuels burned in the main boiler equalling max 30 % of coal. The aim in this Lahden

Comparison between externally fired gas turbine and gasifier-gas turbine system for the olive oil industry

International Nuclear Information System (INIS)

Vera, D.; Jurado, F.; Mena, B. de; Schories, G.

2011-01-01

The olive oil industry generates during the extraction process several solid wastes as olive tree leaves and prunings, exhausted pomace and olive pits. These renewable wastes could be used for power and heat applications. The aim of this paper is to compare the performance of two small-scale CHP systems: a gasification- gas turbine system and an EFGT (externally fired gas turbine system). For this reason, several parameters have been calculated: generated heat and power, electric and overall efficiencies, biomass consumption, exergy efficiency, optimum pressure ratio, etc. These systems provide 30 kW e and about 60kW th . Simulation results show that the electrical and overall efficiencies achieved in EFGT system (19.1% and 59.3%, respectively) are significantly higher than those obtained in the gasification plant (12.3% and 45.4%). The proposed CHP systems have been modeled using Cycle-Tempo ® software. -- Highlights: ► Comparison between externally fired gas turbine and gasifier-gas turbine system. ► Olive oil industry generates several solid wastes as olive tree leaves and prunings. ► Thermodynamic parameters have been calculated. ► Systems have been modeled using Cycle-Tempo ® software. ► Simulation results show electrical and overall efficiencies achieved in the systems.

40 CFR 60.142a - Standards for particulate matter.

Science.gov (United States)

2010-07-01

... the steel production cycle of any top-blown BOPF or during hot metal transfer or skimming operations... Emissions from Basic Oxygen Process Steelmaking Facilities for Which Construction is Commenced After January... occur once per steel production cycle. (2) Exit from a control device used solely for the collection of...

Singlet oxygen quenching by oxygen in tetraphenyl-porphyrin solutions

International Nuclear Information System (INIS)

Dedic, Roman; Korinek, Miloslav; Molnar, Alexander; Svoboda, Antonin; Hala, Jan

2006-01-01

Time-resolved measurement of singlet oxygen infrared phosphorescence is a powerful tool for determination of quantum yields and kinetics of its photosensitization. This technique was employed to investigate in detail the previously observed effect of singlet oxygen quenching by oxygen. The question whether the singlet oxygen is quenched by oxygen in ground or in excited state was addressed by study of two complementary dependencies of singlet oxygen lifetimes: on dissolved oxygen concentration and on excitation intensity. Oxygen concentration dependence study of meso-tetra(4-sulphonato)phenylporphyrin (TPPS 4 ) phosphorescence kinetics showed linearity of the dependence of TPPS 4 triplet state rate-constant. Corresponding bimolecular quenching constant of (1.5±0.1)x10 9 l/mol s was obtained. On the other hand, rate constants of singlet oxygen depopulation exhibit nonlinear dependence on oxygen concentration. Comparison of zero oxygen concentration-extrapolated value of singlet oxygen lifetime of (6.5±0.4) μs to (3.7±0.1) μs observed under air-saturated conditions indicates importance of the effect of quenching of singlet oxygen by oxygen. Upward-sloping dependencies of singlet oxygen depopulation rate-constant on excitation intensity evidence that singlet oxygen is predominantly quenched by oxygen in excited singlet state

LINEAR RELATION FOR WIND-BLOWN BUBBLE SIZES OF MAIN-SEQUENCE OB STARS IN A MOLECULAR ENVIRONMENT AND IMPLICATION FOR SUPERNOVA PROGENITORS

Energy Technology Data Exchange (ETDEWEB)

Chen Yang; Zhou Ping [Department of Astronomy, Nanjing University, Nanjing 210093 (China); Chu Youhua [Department of Astronomy, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, IL 61801 (United States)

2013-05-20

We find a linear relationship between the size of a massive star's main-sequence bubble in a molecular environment and the star's initial mass: R{sub b} Almost-Equal-To 1.22 M/M{sub Sun} - 9.16 pc, assuming a constant interclump pressure. Since stars in the mass range of 8 to 25-30 M{sub Sun} will end their evolution in the red supergiant phase without launching a Wolf-Rayet wind, the main-sequence wind-blown bubbles are mainly responsible for the extent of molecular gas cavities, while the effect of the photoionization is comparatively small. This linear relation can thus be used to infer the masses of the massive star progenitors of supernova remnants (SNRs) that are discovered to evolve in molecular cavities, while few other means are available for inferring the properties of SNR progenitors. We have used this method to estimate the initial masses of the progenitors of eight SNRs: Kes 69, Kes 75, Kes 78, 3C 396, 3C 397, HC 40, Vela, and RX J1713-3946.

Pre-Combustion Carbondioxide Capture in Integrated Gasification Combined Cycles

Directory of Open Access Journals (Sweden)

M. Zeki YILMAZOĞLU

2010-02-01

Full Text Available Thermal power plants have a significant place big proportion in the production of electric energy. Thermal power plants are the systems which converts heat energy to mechanical energy and also mechanical energy to electrical energy. Heat energy is obtained from combustion process and as a result of this, some harmful emissions, like CO2, which are the reason for global warming, are released to atmosphere. The contribution of carbondioxide to global warming has been exposed by the previous researchs. Due to this fact, clean energy technologies are growing rapidly all around the world. Coal is generally used in power plants and when compared to other fossil energy sources unit electricity production cost is less than others. When reserve rate is taken into account, coal may be converted to energy in a more efficient and cleaner way. The aim for using the clean coal technologies are to eradicate the harmful emissions of coal and to store the carbondioxide, orginated from combustion, in different forms. In line with this aim, carbondioxide may be captured by either pre-combustion, by O2/CO2 recycling combustion systems or by post combustion. The integrated gasification combined cycles (IGCC are available in pre-combustion capture systems, whereas in O2/CO2 recycling combustion systems there are ultrasuper critical boiler technologies and finally flue gas washing systems by amines exists in post combustion systems. In this study, a pre-combustion CO2 capture process via oxygen blown gasifiers is compared with a conventional power plant in terms of CO2 emissions. Captured carbondioxide quantity has been presented as a result of the calculations made throughout the study.

DDGS chars gasification with CO{sub 2}: a kinetic study using TG analysis

Energy Technology Data Exchange (ETDEWEB)

Meng, Xiangmei; Jong, Wiebren de; Fu, Ningjie; Verkooijen, Adrian H.M. [Delft University of Technology, Process and Energy Department, Faculty of Mechanical, Maritime and Materials Engineering, Delft (Netherlands)

2011-12-15

Dry Distiller's Grains with Solubles (DDGS) is a by-product during ethanol production from cereals which is currently mainly used as feedstock for cattle. With the growth of the ethanol industry, the increasing supply of DDGS may saturate the livestock feed market; thus, its potential applications need to be explored. DDGS gasification in a 100-kW{sub th} circulating fluidized bed (CFB) steam-O{sub 2} blown gasifier has been studied. However, the modeling of DDGS gasification process encounters difficulties due to the unavailable knowledge of DDGS char gasification kinetics. Therefore, in this paper, gasification kinetics of DDGS char with CO{sub 2} was investigated using thermogravimetric analysis (TGA). Two different types of char samples have been tested. Char type one (PYR-Char) was obtained after DDGS pyrolysis in a TGA at a final temperature of 750 C or 850 C for 20 min. Char type two (CFB-Char) was obtained after DDGS gasification in the 100-kW{sub th} CFB gasifier within the temperature range of 790 C to 820 C with a steam/biomass mass ratio of 0.81 and oxygen to biomass stoichiometric ratio of approximately 0.38. The influences of pyrolysis temperature (750 C, 850 C), heating rate (10 C/min, 30 C/min, 50 C/min, 70 C/min), CO{sub 2} concentration (10, 20, 30 vol.%), and gasification temperature (900 C, 1,000 C, 1,100 C) on the reaction rate of char-CO{sub 2} reaction were determined. Two representative gas-solid reaction models, the volumetric reaction model (VRM) and the shrinking core model (SCM) were applied in order to determine kinetic parameters. It was found that the calculated activation energy (E{sub a}) values using SCM were slightly lower than those using VRM. The calculated E{sub a} values for PYR-Char using both models were in the range of 100-165 kJ/mol, while the calculated E{sub a} values for CFB-Char were in the range of 55-100 kJ/mol. It was observed by scanning electron microscopy (SEM) that CFB-Char was more fragile and PYR

A polygeneration from a dual-gas partial catalytic oxidation coupling with an oxygen-permeable membrane reactor

International Nuclear Information System (INIS)

Hao, Yanhong; Huang, Yi; Gong, Minhui; Li, Wenying; Feng, Jie; Yi, Qun

2015-01-01

Highlights: • A new polygeneration system (PL-PCO-OPMR) to DME/methanol/power is proposed. • Exergeo-economic analysis is adopted to disclose the performance of systems. • Key technological conditions and parameters for PL-PCO-OPMR are optimized. • PL-PCO-OPMR shows high energy efficiency and low CO_2 emission. • PL-PCO-OPMR is an attractive way for high efficient and clean use of COG and CGG. - Abstract: Polygeneration system, typically involving chemicals/fuels and electricity co-production, is a promising technology for the sustainable development of energy and environment. In this study, a new polygeneration system based on coal and coke oven gas (COG) inputs for co-production of dimethyl ether (DME)/methanol and electricity is proposed. In the new system, an appropriate syngas for the synthesis of DME is from coal gasified gas (CGG) reforming of COG coupled with an oxygen-permeable membrane reactor, in which both COG and CGG reforming process and fuel combustion process are incorporated, which reduces exergy destruction in the whole reforming process. In order to obtain the best performance of CO_2 reduction, energy saving and economic benefit, the key operation parameters of the proposed process are analyzed and optimized. The new system is compared with the process based on CH_4/CO_2 dry reforming, in terms of exergy efficiency, exergy cost and CO_2 emissions. Through the new system, the exergy efficiency can be increased by 7.8%, the exergy cost can be reduced by 0.88 USD/GJ and the CO_2 emission can be reduced by 0.023 kg/MJ. These results suggest that the polygeneration system from CGG and COG partial catalytic oxidation coupling with an oxygen-permeable membrane reactor (PL-PCO-OPMR) would be a more attractive way for highly efficient and clean use of CGG and COG.

CHP biomass gasifier for the Zwarts Gerbera Nursery. Technical and economic feasibility; Biomassavergasser-WKK voor Gerberakwekerij Zwarts. Technische inpassing en economische haalbaarheid

Energy Technology Data Exchange (ETDEWEB)

Peeters, S.; Hart, A. [Energy Matters, Driebergen (Netherlands)

2011-10-15

This report describes the feasibility of a CHP gasifier at the Zwarts gerbera nursery. Using the insights from this study, a picture has been sketched for energy production by means of gasification in the horticultural sector. Note, however, that each plant specie has its own specific growth requirements in terms of nutrients, heating-cooling, light, but also relative humidity and CO2. So a 'typical' horticulturer with an 'average' energy requirement is hard to define. The economic viability must be determined for each individual situation. The outcomes of this study can therefore not be automatically used for other projects. Technically, a lot is possible, so the submitted quotes show. Of the 16 suppliers, 3 offer CHP gasifiers which, subject to conditions, not only burn wood but also other low-grade residual waste such as road verge grass, reed and miscanthus. This low-grade residual waste has the advantage of being cheaper than wood. A low biomass price lowers the operating costs and improves the economic profitability of the relatively expensive installations. The investment for a complete CHP gasifier is 5 to 10 times higher than for a normal gas CHP installation. The CO2 consumption also influences the economic profitability. Buying CO2 is a costly business. The technical and economic feasibility of harvesting CO2 from flue gas was therefore explored. Two CO2 harvesting installations (of Procede and Knook) were examined for this purpose. According to Procede and Knook, CO2 harvesting is not economically profitable for a CHP gasifier with a relatively low power capacity (up to 800 kWe). CO2 procurement or generation by means of the existing gas-fired boiler therefore seems more viable. The technical-economic feasibility study shows that an investment in a CHP gasifier is not profitable due to the relatively high investment and maintenance costs. CO2 demand and the uncertain biomass prices are stumbling blocks. However, the picture changes

Biomass Thermochemical Conversion Program. 1984 annual report

Energy Technology Data Exchange (ETDEWEB)

Schiefelbein, G.F.; Stevens, D.J.; Gerber, M.A.

1985-01-01

The objective of the program is to generate scientific data and conversion process information that will lead to establishment of cost-effective process for converting biomass resources into clean fuels. The goal of the program is to develop the data base for biomass thermal conversion by investigating the fundamental aspects of conversion technologies and by exploring those parameters that are critical to the conversion processes. The research activities can be divided into: (1) gasification technology; (2) liquid fuels technology; (3) direct combustion technology; and (4) program support activities. These activities are described in detail in this report. Outstanding accomplishments during fiscal year 1984 include: (1) successful operation of 3-MW combustor/gas turbine system; (2) successful extended term operation of an indirectly heated, dual bed gasifier for producing medium-Btu gas; (3) determination that oxygen requirements for medium-Btu gasification of biomass in a pressurized, fluidized bed gasifier are low; (4) established interdependence of temperature and residence times on biomass pyrolysis oil yields; and (5) determination of preliminary technical feasibility of thermally gasifying high moisture biomass feedstocks. A bibliography of 1984 publications is included. 26 figs., 1 tab.

Macauba gasification; Gaseificacao da macauba

Energy Technology Data Exchange (ETDEWEB)

Santos Filho, Jaime dos; Oliveira, Eron Sardinha de [Instituto Federal de Educacao, Ciencia e Tecnologia da Bahia (IFBA), Vitoria da Conquista, BA (Brazil)], E-mail: jaime@ifba.edu.br; Silva, Jadir Nogueira da; Galvarro, Svetlana Fialho Soria [Universidade Federal de Vicosa (UFV), MG (Brazil); Chaves, Modesto Antonio [Universidade Estadual do Sudoeste da Bahia (UESB), Itapetinga, BA (Brazil). Dept. de Engenharia de Alimentos

2009-07-01

For development of a productive activity, with reduced environmental degradation, the use of renewable energy sources as an important option. The gasification has been increasing among the ways of obtaining energy from biomass, and consists of a process where the necessary oxygen to the complete combustion of a fuel it is restricts and, in high temperatures it generates fuel gas of high-quality. In this direction, this work is justified and has its importance as the study of a renewable energy source, macauba coconut (Acrocomia aculeata [Jacq] Lodd), with the gasification process. The objective of this study is to build a biomass concurrent gasifier and evaluate the viability to provide heating for dehydration of fruits, using the macauba coconut as fuel. It was measured the temperature in five points distributed in both gasifier and combustor chamber, being the input area of primary combustor air and also the speed of rotation of the electric motor, using a factorial 3X3 experimental design with three repetitions and interval of measurements of five minutes. The analytical results take to infer that the macauba coconut have potential to be gasified and used for the dehydration of fruits. (author)

Fluidised bed gasification of low grade South African coals

CSIR Research Space (South Africa)

North, BC

2006-09-01

Full Text Available gasifiers. Fluidised bed Entrained flow Coal particle size 0.5 mm – 5 mm 0 – 0.5 mm Coal moisture Dry Dry/slurry Coal type Non-caking coals Any coal Ash in coal < 60% < 30% Gasification agents Air/steam/oxygen Steam/oxygen Gasification... properties important for fluidised bed gasification are: square4 Coal reactivity in atmospheres of CO2 and H2O square4 Caking index and free swelling index (FSI) square4 Ash fusion temperature (AFT) 5.1 Coal reactivity The gasifcation reactions (1...

Results from study of potential early commercial MHD power plants and from recent ETF design work. [Engineering Test Facility

Science.gov (United States)

Hals, F.; Kessler, R.; Swallom, D.; Westra, L.; Zar, J.; Morgan, W.; Bozzuto, C.

1980-01-01

The study deals with different 'moderate technology' entry-level commercial MHD power plants. Two of the reference plants are based on combustion of coal with air preheated in a high-temperature regenerative air heater separately fired with a low-BTU gas produced in a gasifier integrated with the power plant. The third reference plant design is based on the use of oxygen enriched combustion air. Performance calculations show that an overall power plant efficiency of the order of 44% can be reached with the use of oxygen enrichment.

Results from study of potential early commercial MHD power plants and from recent ETF design work

Science.gov (United States)

Hals, F.; Kessler, R.; Swallom, D.; Westra, L.; Zar, J.; Morgan, W.; Bozzuto, C.

1980-06-01

The study deals with different 'moderate technology' entry-level commercial MHD power plants. Two of the reference plants are based on combustion of coal with air preheated in a high-temperature regenerative air heater separately fired with a low-BTU gas produced in a gasifier integrated with the power plant. The third reference plant design is based on the use of oxygen enriched combustion air. Performance calculations show that an overall power plant efficiency of the order of 44% can be reached with the use of oxygen enrichment.

Equilibrium modeling of gasification: Gibbs free energy minimization approach and its application to spouted bed and spout-fluid bed gasifiers

International Nuclear Information System (INIS)

Jarungthammachote, S.; Dutta, A.

2008-01-01

Spouted beds have been found in many applications, one of which is gasification. In this paper, the gasification processes of conventional and modified spouted bed gasifiers were considered. The conventional spouted bed is a central jet spouted bed, while the modified spouted beds are circular split spouted bed and spout-fluid bed. The Gibbs free energy minimization method was used to predict the composition of the producer gas. The major six components, CO, CO 2 , CH 4 , H 2 O, H 2 and N 2 , were determined in the mixture of the producer gas. The results showed that the carbon conversion in the gasification process plays an important role in the model. A modified model was developed by considering the carbon conversion in the constraint equations and in the energy balance calculation. The results from the modified model showed improvements. The higher heating values (HHV) were also calculated and compared with the ones from experiments. The agreements of the calculated and experimental values of HHV, especially in the case of the circular split spouted bed and the spout-fluid bed were observed

Aerodynamic excitation and sound production of blown-closed free reeds without acoustic coupling: The example of the accordion reed

Science.gov (United States)

Ricot, Denis; Caussé, René; Misdariis, Nicolas

2005-04-01

The accordion reed is an example of a blown-closed free reed. Unlike most oscillating valves in wind musical instruments, self-sustained oscillations occur without acoustic coupling. Flow visualizations and measurements in water show that the flow can be supposed incompressible and potential. A model is developed and the solution is calculated in the time domain. The excitation force is found to be associated with the inertial load of the unsteady flow through the reed gaps. Inertial effect leads to velocity fluctuations in the reed opening and then to an unsteady Bernoulli force. A pressure component generated by the local reciprocal air movement around the reed is added to the modeled aerodynamic excitation pressure. Since the model is two-dimensional, only qualitative comparisons with air flow measurements are possible. The agreement between the simulated pressure waveforms and measured pressure in the very near-field of the reed is reasonable. In addition, an aeroacoustic model using the permeable Ffowcs Williams-Hawkings integral method is presented. The integral expressions of the far-field acoustic pressure are also computed in the time domain. In agreement with experimental data, the sound is found to be dominated by the dipolar source associated by the strong momentum fluctuations of the flow through the reed gaps. .

The formation of filamentary structures from molten silicates: Peleʼs hair, angel hair, and blown clinker

Science.gov (United States)

Villermaux, Emmanuel

2012-08-01

We conduct an analysis of the concomitant, competing phenomena at play in the formation of long filamentary structures from a stream of hot, very viscous and cohesive liquid as it is blown by a fast, cool air stream. The situation is relevant to a broad class of problems, namely volcanic glass threads or fibers formed when small particles of molten material are thrown into the air and spun out by the wind into long hair-like strands (called Pele's hair), to the process of prilling, the manufacture of glass fibers, and the formation of coke in furnaces and combustion chambers. The air stream blowing on the molten material both breaks up the liquid into fragments stabilized by capillarity, and cools the liquid down to solidification. There are, in this problem, four characteristic times. First, a deformation time of the liquid masses, setting the rate at which drops elongate into ligaments. Then, two timescales set the time of capillary breakup of these ligaments, one prevailing on the other depending on the relative weight of inertia on viscous slowing (that point is illustrated by an original experiment). Finally, a solidification time of the ligaments. Thin solid strands will only form when solidification occurs before capillary breakup. We have discovered that this condition is likely to apply when the liquid is strongly viscous, as for clinker in the cement industry, considered here as a generic example. We formulate recommendations to remove (or enhance) the formation of these objects.

WABASH RIVER INTEGRATED METHANOL AND POWER PRODUCTION FROM CLEAN COAL TECHNOLOGIES (IMPPCCT)

Energy Technology Data Exchange (ETDEWEB)

Doug Strickland; Albert Tsang

2002-10-14

The Wabash River Integrated Methanol and Power Production from Clean Coal Technologies (IMPPCCT) project is evaluating integrated electrical power generation and methanol production through clean coal technologies. The project is conducted by a multi-industry team lead by Gasification Engineering Corporation (GEC), and supported by Air Products and Chemicals, Inc., Dow Chemical Company, Dow Corning Corporation, Methanex Corporation, and Siemens Westinghouse Power Corporation. Three project phases are planned for execution over a three year period, including: (1) Feasibility study and conceptual design for an integrated demonstration facility, and for fence-line commercial plants operated at Dow Chemical or Dow Corning chemical plant locations; (2) Research, development, and testing to define any technology gaps or critical design and integration issues; and (3) Engineering design and financing plan to install an integrated commercial demonstration facility at the existing Wabash River Energy Limited (WREL) plant in West Terre Haute, Indiana. This report describes management planning, work breakdown structure development, and feasibility study activities by the IMPPCCT consortium in support of the first project phase. Project planning activities have been completed, and a project timeline and task list has been generated. Requirements for an economic model to evaluate the West Terre Haute implementation and for other commercial implementations are being defined. Specifications for methanol product and availability of local feedstocks for potential commercial embodiment plant sites have been defined. The WREL facility is a project selected and co-funded under the fifth phase solicitation of the U.S. Department of Energy's Clean Coal Technology Program. In this project, coal and/or other solid fuel feedstocks are gasified in an oxygen-blown, entrained-flow gasifier with continuous slag removal and a dry particulate removal system. The resulting product synthesis

FY 1993 report on the results of the subsidy project for the Sunshine Project. Development of coal use hydrogen production technology (Support study of pilot plant - Study using the small equipment); 1993 nendo Sunshine keikaku hojo jigyo seika hokokusho. Sekitan riyo suiso seizo gijutsu kaihatsu - Pilot plant no shien kenkyu (Kogata souchi ni yoru kenkyu)

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-03-01

As to the development of coal use hydrogen production technology, the paper studied the reactivity of char and ignition characteristics of various coals in the use of electric furnace and the participation in pilot plant test and the improvement, and the FY 1993 results were reported. In the study of reactivity of char, it was found that the reactivity was the same, regardless of the equipment and kind of raw coal, if considered of the ratio of the total oxygen amount (the char-containing oxygen amount added to the oxygen supply amount) to the carbon supply amount in char. In the test on ignition characteristics of overseas coals, the same characteristics as those of the Taiheiyo coal conventionally tested were obtained and it was found that it was good to use the same method for start-up of gasifier as conventionally used. In the pilot plant test in the previous year, slag and ash stuck to the outlet of the gasification part and heat recovery part and developed, which hindered the continued operation. To improve it, the following were carried out: model study, study of ash sintering, study using the synthetic test equipment, analysis of the deposit in gasifier, etc. Based on these results, the plant was improved, and the continued operation of 1,149 hours was stably achieved in RUN8. (NEDO)

Integrated Sensing and Controls for Coal Gasification - Development of Model-Based Controls for GE's Gasifier and Syngas Cooler

Energy Technology Data Exchange (ETDEWEB)

Aditya Kumar

2010-12-30

This report summarizes the achievements and final results of this program. The objective of this program is to develop a comprehensive systems approach to integrated design of sensing and control systems for an Integrated Gasification Combined Cycle (IGCC) plant, using advanced model-based techniques. In particular, this program is focused on the model-based sensing and control system design for the core gasification section of an IGCC plant. The overall approach consists of (i) developing a first-principles physics-based dynamic model of the gasification section, (ii) performing model-reduction where needed to derive low-order models suitable for controls analysis and design, (iii) developing a sensing system solution combining online sensors with model-based estimation for important process variables not measured directly, and (iv) optimizing the steady-state and transient operation of the plant for normal operation as well as for startup using model predictive controls (MPC). Initially, available process unit models were implemented in a common platform using Matlab/Simulink{reg_sign}, and appropriate model reduction and model updates were performed to obtain the overall gasification section dynamic model. Also, a set of sensor packages were developed through extensive lab testing and implemented in the Tampa Electric Company IGCC plant at Polk power station in 2009, to measure temperature and strain in the radiant syngas cooler (RSC). Plant operation data was also used to validate the overall gasification section model. The overall dynamic model was then used to develop a sensing solution including a set of online sensors coupled with model-based estimation using nonlinear extended Kalman filter (EKF). Its performance in terms of estimating key unmeasured variables like gasifier temperature, carbon conversion, etc., was studied through extensive simulations in the presence sensing errors (noise and bias) and modeling errors (e.g. unknown gasifier kinetics, RSC

The potential for control of carbon dioxide emissions from integrated gasification/combined-cycle systems

Energy Technology Data Exchange (ETDEWEB)

Livengood, C.D.; Doctor, R.D.; Molburg, J.C.; Thimmapuram, P.; Berry, G.F.

1994-06-01

Initiatives to limit carbon dioxide (CO{sub 2}) emissions have drawn considerable interest to integrated gasification/combined-cycle (IGCC) power generation, a process that reduces CO{sub 2} production through efficient fuel used is amenable to CO{sub 2} capture. This paper presents a comparison of energy systems that encompass fuel supply, an IGCC system, CO{sub 2} recovery using commercial technologies, CO{sub 2} transport by pipeline, and land-based sequestering in geological reservoirs. The intent is to evaluate the energy-efficiency impacts of controlling CO{sub 2} in such systems and to provide the CO{sub 2} budget, or an to equivalent CO{sub 2}`` budget, associated with each of the individual energy-cycle steps. The value used for the ``equivalent CO{sub 2}`` budget is 1 kg/kWh CO{sub 2}. The base case for the comparison is a 457-MW IGCC system that uses an air-blown Kellogg-Rust-Westinghouse (KRW) agglomerating fluidized-bed gasifier, Illinois No. 6 bituminous coal, and in-bed sulfur removal. Mining, preparation, and transportation of the coal and limestone result in a net system electric power production of 454 MW with a 0.835 kg/kwh CO{sub 2} release rate. For comparison, the gasifier output is taken through a water-gas shift to convert CO to CO{sub 2} and then processed in a glycol-based absorber unit to recover CO{sub 2} Prior to the combustion turbine. A 500-km pipeline then transports the CO{sub 2} for geological sequestering. The net electric power production for the system with CO{sub 2} recovery is 381 MW with a 0.156 kg/kwh CO{sub 2} release rate.

Using fuzzy logic to control the power of a biomass gasifier ventilation system motor to ensure suitable oxidation temperature for tar cracking; Uso da logica fuzzy para controle da potencia do motor do sistema de ventilacao de um gaseificador de biomassa que assegure temperatura de oxidacao adequada para craqueamento do alcatrao

Energy Technology Data Exchange (ETDEWEB)

Rezende, Oscar L.T.; Kulitz, Hans H. [Instituto Federal de Educacao, Ciencia e Tecnologia do Espirito Santo (IFES), Vitoria, ES (Brazil)], email: oscar@ifes.edu.br; Silva, Jadir N.; Galvarro, Svetlana F.S. [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Engenharia Agricola; Martin, Samuel [Universidade de Brasilia (FAV/UNB), DF (Brazil). Fac. de Agronomia e Medicina Veterinaria

2011-07-01

There are several models of biomass gasifier. The one used in this study was the concurrent model, in which fuel is fed through the top and air feed occurs in descending flow through combustion and reduction zones, producing low-tar gas. Nevertheless, total tar burning must be ensured in order to produce a gas, suitable for several applications. This study aimed at developing a fuzzy-based algorithm to control the active power applied to a gasifier ventilation system motor, which can ensure adequate oxidation temperature for cracking tar that may be present in the gas produced. The input variables of the fuzzy controller were oxidation zone temperature and the variation rate of this temperature. The output variable was active power. The rule base was created using experimental data. The tests performed with this algorithm allowed observing that the oxidation temperature can be set to a value desired, which does not occur in gasification processes without ventilation system control. (author)

Oxygen toxicity

Directory of Open Access Journals (Sweden)

C. A. van der Westhuizen

1990-07-01

Full Text Available Oxygen has been discovered about 200 years ago. Since then the vital physiological involvement of oxygen in various biologi­cal processes, mainly energy production, has been established. However, in the body molecular oxygen can be converted to toxic oxygen metabolites such as superoxide anion, hydrogen peroxide, the hydroxyl radical and singlet oxygen. These toxic metabolites are produced mainly in the mitochondria, plasma membranes and endoplasmic reticulum.

IGCC demonstration project status combustion engineering IGCC repowering project

International Nuclear Information System (INIS)

Glamuzina, R.W.; Allen, R.J.; Peletz, L.J.

1993-01-01

This demonstration project was originally conceived as the repowering of an existing plant facility, the Lakeside Station in Springfield, Illinois. The Owner, City Water, Light and Power (CWL ampersand P), has removed five of the original boilers and three of the original turbines. The buildings have had asbestos insulation removed and the interiors have been prepared for the construction of a single Integrated Gasification Combined Cycle (IGCC) process train that will generate a net output of 60 megawatts. The plant consists of a combined cycle (gas turbine, heat recovery steam generator, steam turbine) power train located in the existing buildings and a coal gasification system in a new building. The gasification system contains ABB CE's air-blown, entrained flow, two stage gasifier, an advanced hot gas desulfurization system by General Electric Environmental Services, Inc. and the necessary auxiliary systems. The plant is designed to produce a nominal 60 MW net output with an ambient air temperature of 95 degrees F and a cooling water temperature of 89 degrees F on either Natural Gas or Illinois No. 5 coal

Comprehensive report to Congress Clean Coal Technology Program

Energy Technology Data Exchange (ETDEWEB)

1990-10-01

This project will demonstrate Integrated Gasification Combined Cycle (IGCC) technology in a commercial application by the repowering of an existing City Water, Light and Power (CWL P) Plant in Springfield, Illinois. The project duration will be 126 months, including a 63-month demonstration period. The estimated cost of the project is $270,700,000 of which $129,357,204 will be funded by DOE. The IGCC system will consist of CE's air-blown, entrained-flow, two-stage, pressurized coal gasifier; an advanced hot gas cleanup process; a combustion turbine modified to use low Btu coal gas; and all necessary coal handling equipment. An existing 25-MWe steam turbine and associated equipment will also be part of the IGCC system. The result of repowering will be an IGCC power plant with low environmental emissions and high net plant efficiency. The repowering will increase plant output by 40 MWe through addition of the combustion turbine, thus providing a total IGCC capacity of a nominal 65 MWe. 3 figs., 2 tabs.

The effect of gastric dilatation in rats submitted to gasified water ingestion under the hepatic metabolic function Efeito da dilatação gástrica em ratos submetidos à ingestão de água gaseificada sobre a função metabólica hepática

Directory of Open Access Journals (Sweden)

José Roberto Ferreira Santiago

2008-10-01

Full Text Available INTRODUCTION: The amounts of people that are overweight have been increasing within the population in significant ways during the last decades. In this view, gasified beverages have become an important environmental concern in relation to the eating habits of people, especially who lives in the USA, Mexico, and Brazil. In this order, these three countries constitute the major beverages producers and consumers of the whole world. PURPOSE: To investigate the effects of gastric dilatation in rats submitted to gasified water ingestion, uniform vehicle for all soft drinks, under metabolic patterns of the hepatic function. METHODS: Two groups of 15 rats were formed and observed during two weeks. The rats of the group I, were fed with 200g/day of rat food ad libitum and 100ml of non-gasified water during three daily periods. The rats composing the group II, were fed with 200g/day of rat food ad libitum and 100ml of gasified water within 3 daily periods. The media (x and standard deviation (s were calculated through the paired t-test for each group in order to compare the effects of the different types of water and its effect in each one of them. RESULTS: The results indicated that the animals which were submitted to the treatment with gasified water (G-II, presented an increase of glutamic-pyruvic transaminase (GPT and alkaline phosphatase (ALP (pp>0,05 and increase of the gastric area with macroscopic morphologic alterations, such as the loss of the characteristic linear depressions on the surface of the mucous membrane. CONCLUSION: The gasified water favored the expansion of the gastric area and contributed to the extinction of the linear depressions of the mucous organ, which caused metabolic alterations of the hepatic function.INTRODUÇÃO: O excesso de peso na população aumentou de forma significante nas últimas décadas e as bebidas gasosas tornaram-se um fator ambiental importante no comportamento alimentar das pessoas, sendo os EUA, M�

Mixed oxygen ion/electron-conducting ceramics for oxygen separation

Energy Technology Data Exchange (ETDEWEB)

Stevenson, J.W.; Armstrong, T.R.; Armstrong, B.L. [Pacific Northwest National Lab., Richland, WA (United States)

1996-08-01

Mixed oxygen ion and electron-conducting ceramics are unique materials that can passively separate high purity oxygen from air. Oxygen ions move through a fully dense ceramic in response to an oxygen concentration gradient, charge-compensated by an electron flux in the opposite direction. Compositions in the system La{sub 1{minus}x}M{sub x}Co{sub 1{minus}y{minus}z}Fe{sub y}N{sub z}O{sub 3{minus}{delta}}, perovskites where M=Sr, Ca, and Ba, and N=Mn, Ni, Cu, Ti, and Al, have been prepared and their electrical, oxygen permeation, oxygen vacancy equilibria, and catalytic properties evaluated. Tubular forms, disks, and asymmetric membrane structures, a thin dense layer on a porous support of the same composition, have been fabricated for testing purposes. In an oxygen partial gradient, the passive oxygen flux through fully dense structures was highly dependent on composition. An increase in oxygen permeation with increased temperature is attributed to both enhanced oxygen vacancy mobility and higher vacancy populations. Highly acceptor-doped compositions resulted in oxygen ion mobilities more than an order of magnitude higher than yttria-stabilized zirconia. The mixed conducting ceramics have been utilized in a membrane reactor configuration to upgrade methane to ethane and ethylene. Conditions were established to balance selectivity and throughput in a catalytic membrane reactor constructed from mixed conducting ceramics.

Maximizing biofuel production in a thermochemical biorefinery by adding electrolytic hydrogen and by integrating torrefaction with entrained flow gasification

DEFF Research Database (Denmark)

Clausen, Lasse Røngaard

2015-01-01

double the biofuel production per biomass input by converting almost all of the carbon in the biomass feed to carbon stored in the biofuel product. Water or steam electrolysis can supply the hydrogen to the biorefinery and also the oxygen for the gasifier. This paper presents the design and thermodynamic...... analysis of two biorefineries integrating water electrolysis for the production of methanol. In both plants, torrefied woody biomass is supplied to an entrained flow gasifier, but in one of the plants, the torrefaction process occurs on-site, as it is integrated with the entrained flow gasification process....... The analysis shows that the biorefinery with integrated torrefaction has a higher biomass to methanol energy ratio (136% vs. 101%) as well as higher total energy efficiency (62% vs. 56%). By comparing with two identical biorefineries without electrolysis, it is concluded that the biorefinery with integrated...

Static Thermochemical Model of COREX Melter Gasifier

Science.gov (United States)

Srishilan, C.; Shukla, Ajay Kumar

2018-02-01

COREX is one of the commercial smelting reduction processes. It uses the finer size ore and semi-soft coal instead of metallurgical coke to produce hot metal from iron ore. The use of top gas with high calorific value as a by-product export gas makes the process economical and green. The predictive thermochemical model of the COREX process presented here enables rapid computation of process parameters such as (1) required amount of ore, coal, and flux; (2) amount of slag and gas generated; and (3) gas compositions (based on the raw material and desired hot metal quality). The model helps in predicting the variations in process parameters with respect to the (1) degree of metallization and (2) post-combustion ratio for given raw material conditions. In general reduction in coal, flux, and oxygen, the requirement is concomitant with an increase in the degree of metallization and post-combustion ratio. The model reported here has been benchmarked using industrial data obtained from the JSW Steel Plant, India.

Closed Loop Control of Oxygen Delivery and Oxygen Generation

Science.gov (United States)

2017-08-01

were used for this study and were connected via a USB cable to allow communication. The ventilator was modified to allow closed loop control of oxygen...connected via a USB cable to allow communication. The ventilator was modified to allow closed loop control of oxygen based on the oxygen saturation...2017-4119, 28 Aug 2017. oximetry (SpO2) and intermittent arterial blood sampling for arterial oxygen tension (partial pressure of oxygen [PaO2]) and

High-Energy-Density Metal-Oxygen Batteries: Lithium-Oxygen Batteries vs Sodium-Oxygen Batteries.

Science.gov (United States)

Song, Kyeongse; Agyeman, Daniel Adjei; Park, Mihui; Yang, Junghoon; Kang, Yong-Mook

2017-12-01

The development of next-generation energy-storage devices with high power, high energy density, and safety is critical for the success of large-scale energy-storage systems (ESSs), such as electric vehicles. Rechargeable sodium-oxygen (Na-O 2 ) batteries offer a new and promising opportunity for low-cost, high-energy-density, and relatively efficient electrochemical systems. Although the specific energy density of the Na-O 2 battery is lower than that of the lithium-oxygen (Li-O 2 ) battery, the abundance and low cost of sodium resources offer major advantages for its practical application in the near future. However, little has so far been reported regarding the cell chemistry, to explain the rate-limiting parameters and the corresponding low round-trip efficiency and cycle degradation. Consequently, an elucidation of the reaction mechanism is needed for both lithium-oxygen and sodium-oxygen cells. An in-depth understanding of the differences and similarities between Li-O 2 and Na-O 2 battery systems, in terms of thermodynamics and a structural viewpoint, will be meaningful to promote the development of advanced metal-oxygen batteries. State-of-the-art battery design principles for high-energy-density lithium-oxygen and sodium-oxygen batteries are thus reviewed in depth here. Major drawbacks, reaction mechanisms, and recent strategies to improve performance are also summarized. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Oxygen Therapy

Directory of Open Access Journals (Sweden)

Bonnie Solmes

2000-01-01

Full Text Available LTOT is prescribed for people with chronic lung disease in whom there is a decrease in the ability of the lungs to supply enough oxygen to the body. The heart is obliged to pump faster to meet the body's oxygen requirements. This may place undue stress on the heart, resulting in palpitations, dizziness and fatigue. A low oxygen level in arterial blood is also harmful to the heart, the brain and the pulmonary blood vessels. Oxygen therapy is used to break this cycle. A person with low blood oxygen will often be able to accomplish more with less fatigue with the help of supplemental oxygen therapy. Shortness of breath is a mechanical problem resulting from the effects of chronic obstructive pulmonary disease. Oxygen therapy may or may not reduce shortness of breath, but it will help the lungs and heart to function with less stress.

[Domiciliary oxygen therapy].

Science.gov (United States)

Abdel Kafi, S

2010-09-01

In Belgium, oxygen therapy is becoming more and more accessible. When oxygen is needed for short periods or for special indications as palliative care, an agreement between mutual insurance companies and pharmacists allows the practitioner the home installation of gazeous oxygen cylinder or of oxygen concentrator. When long term oxygen therapy (LTOT) is indicated for patients with respiratory insufficiency, the pneumologist must first ask the INAMI the authorization to install one of the following modalities: oxygen concentrator with or without demand oxygen delivery cylinder and liquid oxygen. The goal of LTOT is to increase survival and quality of life. The principal and well accepted indication for LTOT is severe hypoxemia. The beneficial effects of oxygen therapy limited at night or on exertion are controversial. In order to increase patient's autonomy, oxygen can be prescribed for ambulation, respecting prescription's rules. At each step of oxygen therapy implementing (indication, choice of the device and follow-up) the patient under oxygen may benefit from a joint approach between the general practitioner and the chest specialist.

Oxygen therapy - infants

Science.gov (United States)

... breathe increased amounts of oxygen to get normal levels of oxygen in their blood. Oxygen therapy provides babies with the extra oxygen. Information Oxygen is a gas that the cells in your body need to work properly. The ...

Ambitious coal to gasoline plan

Energy Technology Data Exchange (ETDEWEB)

Taffe, P

1979-06-20

A design study carried out by Badger Energy concludes that the first US commercial gasoline from coal facility could be completed in eight years. The cost of gasoline would be 1.09 US dollars/gal. in 1990 with coal at 25 US dollars/ton. The process involves oxygen-blown coal gasification, conversion to methanol by the Mobil process, gas fractionation and HF alkylation.

Experimental numerical study utilizing CFD in a stratified gasifier operating with biomass; Estudio numerico experimental de un gasificador estratificado que opera con biomasa, utilizando CFD

Energy Technology Data Exchange (ETDEWEB)

Rogel Ramirez, Alejandro

2007-07-01

The central idea behind this work is the developing of a numeric-experimental model, useful to optimize the biomass stratified gasifier design. Firstly, model validation will be carried up by comparison with reference experimental data available. This study describes a 1-D + 2-D numerical model used to simulate the gasification of pine wood pellets in a stratified downdraft gasifier whereby Eulerian conservation equations are solved for particle and gas phase components, velocities and specific enthalpies. The model takes into account the biomass particle process such as heating up, drying, primary pyrolysis of biomass, secondary pyrolysis of tar, homogeneous reactions and heterogeneous combustion/gasification reactions, and particle size change. This CFD model can be used to predict temperature profiles, gas composition, producer gas lower heating value, and carbon conversion efficiency, and the reactor performance when operating parameters and feed properties are changed. The standard {kappa}-{epsilon} and RNG {kappa}-{epsilon} models were used to simulate the turbulent flow conditions. [Spanish] La idea central del presente trabajo es el desarrollo de un modelo numerico- experimental, para optimizar el diseno de gasificadores estratificados de biomasa. Primeramente, el modelo sera validado utilizando datos experimentales disponibles en la literatura. Este estudio describe un modelo numerico 1-D+2-D, utilizado para simular la gasificacion de 'pelets' de madera de pino en un gasificador estratificado de flujos paralelos, en el que se resuelven ecuaciones de conservacion Eulerianas para los componentes de la fase gaseosa, la fase solida, velocidades y entalpias especificas. El modelo considera procesos como: calentamiento, secado de la biomasa, pirolisis primaria de la madera, pirolisis secundaria de los alquitranes, reacciones homogeneas, reacciones heterogeneas de combustion/gasificacion y cambio en el tamano de la particula. Este modelo CFD puede ser

CFD modelling of an open core downdraft moving bed biomass gasifier; Modelado de un gasificador estratificado de lecho movil de biomasa, utilizando CFD

Energy Technology Data Exchange (ETDEWEB)

Rogel-Ramirez, A [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)]. E-mail: ARogelR@iingen.unam.mx

2008-10-15

This paper contains the description of a bidimensional Computational Fluid Dynamics (CFD), model Developer to simulate the flow and reaction in a stratified downdraft biomass gasifier, whereby Eulerian conservation equations are solved for particle and gas phase components, velocities and specific enthalpies. The model is based on the PHOENICS package and represents a tool which can be used in gasifier analysis and design. Contributions of chemical kinetics and the mixing rate using the EBU approach are considered in the gas phase global homogeneous reactions. The harmonic blending of chemical kinetics and mass transfer effects, determine the global heterogeneous reactions between char and O{sub 2}, CO{sub 2} and H{sub 2}O. The turbulence effect in the gas phase is accounted by the standard {kappa}-{epsilon} approach. The model provides information of the producer gas composition, velocities and temperature at the outlet, and allows different operating parameters and feed properties to be changed. Finally, a comparison with experimental data available in literature was done, which showed satisfactory agreement from a qualitative point of view, though further validation is required. [Spanish] Este estudio describe un modelo numerico bidimensional, basado en Dinamica de Fluidos Computacional (CFD), desarrollado para simular el flujo y las reacciones que ocurren en un gasificador estratificado de flujos paralelos, en el que se resuelven ecuaciones de conservacion Eulerianas para los componentes de la fase gaseosa, la fase solida, velocidades y entalpias especificas. El modelo esta basado en el codigo PHOENICS y representa una herramienta que puede ser utilizada en el analisis y diseno de gasificadores. En las reacciones globales homogeneas se consideran las contribuciones de la cinetica quimica y la rapidez de mezclado, usando el modelo Eddy Brake-UP (EBU). La medida harmonica de la cinetica quimica y la transferencia de masa, determinan las velocidades globales de

Oxygen diffusion and oxygen effect in tumor tissue

International Nuclear Information System (INIS)

Eissa, H.M.; Hehn, G.

1979-06-01

The diffusion of oxygen in tumor cords of bronchus carcinoma of the lung have been studied with refined computer methods for solving the diffusion equation in axis symmetric tumor structures. In this tumor configuration we may find three different regions consisting of euoxic cells, hypoxic tumor cells and necrotic parts. In the case of oxygen supply from a capillary inside a cylinder of tumor tissue with radius 200 μm or in a tumor cord of radius 300 μm with oxygen supply by capillaries outside, we get a relation of well oxygenated cells to hypoxic cells approximately as 1:8 or as 1:1.1 respectively. Of course most of the tumor cords observed in histological slices have smaller diameters, so that an average of approximately 20% hypoxic cells can be assumed. Based on the work of Ardenne, the diffusion of oxygen and glucose in a tumor of type DS-carcinosarcom has been investigated in both intact tumor and tumor treated with ionizing radiation. We can show that a strong reoxygenation effect takes place in that the well supplied regions may increase in some tumor configurations up to a factor of four by volume. The biological consequences of the oxygen pressure determined in tumor cells are discussed in detail. The investigation of oxygen diffusion in the intercapillary tumor region should give a quantitative physical basis for considering the oxygen effect with the aim to explain the advantages of neutron therapy against conventional radiotherapy. (orig./MG) [de

Biomass gasification for electric power generation. Biomassa vergassing voor elektriciteitsopwekking

Energy Technology Data Exchange (ETDEWEB)

Croezen, H J

1992-10-01

Attention is paid to power generation by means of the use of synthesis gas, produced by biomass gasification, in internal combustion engines and gas turbines. Descriptions are given of the biomass gasification process and several types of gasifiers: cocurrent or downcraft gasifiers, countercurrent gasifiers, crosscurrent gasifiers and fluidized bed gasifiers. The first aim of this report is to assess which gasifier is the most appropriate gasifier to be used in combination with an internal combustion engine or a gas turbine. The second aim is to determine the quality of the biomass fuel, which must be gasified in a particular gasifier. In chapter two the notion biomass is discussed, and in chapter three attention is paid to the gasification process. An overview of the characteristics of available gasifiers is presented in chapter four (performance, quality of the synthesis gas and the biomass fuel, investment costs, and state of the art). In chapter five and six the internal combustion engine and the gas turbine are dealt with, as well as the experiences with and the consequences of the use of synthesis gas. Also the economic feasibility of the application of combined gasifier/engine systems and gasifier/gas turbine systems is discussed. 39 figs., 20 tabs., 43 refs.

Technical and economic assessment of producing hydrogen by reforming syngas from the Battelle indirectly heated biomass gasifier

International Nuclear Information System (INIS)

Mann, M.K.

1995-08-01

The technical and economic feasibility of producing hydrogen from biomass by means of indirectly heated gasification and steam reforming was studied. A detailed process model was developed in ASPEN Plus trademark to perform material and energy balances. The results of this simulation were used to size and cost major pieces of equipment from which the determination of the necessary selling price of hydrogen was made. A sensitivity analysis was conducted on the process to study hydrogen price as a function of biomass feedstock cost and hydrogen production efficiency. The gasification system used for this study was the Battelle Columbus Laboratory (BCL) indirectly heated gasifier. The heat necessary for the endothermic gasification reactions is supplied by circulating sand from a char combustor to the gasification vessel. Hydrogen production was accomplished by steam reforming the product synthesis gas (syngas) in a process based on that used for natural gas reforming. Three process configurations were studied. Scheme 1 is the full reforming process, with a primary reformer similar to a process furnace, followed by a high temperature shift reactor and a low temperature shift reactor. Scheme 2 uses only the primary reformer, and Scheme 3 uses the primary reformer and the high temperature shift reactor. A pressure swing adsorption (PSA) system is used in all three schemes to produce a hydrogen product pure enough to be used in fuel cells. Steam is produced through detailed heat integration and is intended to be sold as a by-product

Oxygen effect and intracellular oxygen content (adaptation hypothesis)

Energy Technology Data Exchange (ETDEWEB)

Yarmonenko, S P; Ehpshtejn, I M [Akademiya Meditsinskikh Nauk SSSR, Moscow. Onkologicheskij Tsentr

1977-01-01

Experimental data indicating that a radiomodifying action of hypoxia is dependent on the ''prehistory'' of the irradiated object are considered. This dependence manifests itself in a decreased protective action of acute hypoxia on the hypoxia-adapted objects. To explain this a hypothesis is proposed connecting a degree of cell radiosensitivity modification, determined by the oxygen effect, with the intracellular oxygen content. The latter, in accord with current ideas, is regulated by variations in the diffusion resistance to oxygen shown by the cytoplasmic membranes depending on the energy level of the cell and the degree of its oxygenation.

Oxygen effect and intracellular oxygen content (adaptation hypothesis)

International Nuclear Information System (INIS)

Yarmonenko, S.P.; Ehpshtejn, I.M.

1977-01-01

Experimental data indicating that a radiomodifying action of hypoxia is dependent on the ''prehistory'' of the irradiated object are considered. This dependence manifests itself in a decreased protective action of acute hypoxia on the hypoxia-adapted objects. To explain this a hypothesis is proposed connecting a degree of cell radiosensitivity modification, determined by the oxygen effect, with the intracellular oxygen content. The latter, in accord with current ideas, is regulated by variations in the diffusion resistance to oxygen shown by the cytoplasmic membranes depending on the energy level of the cell and the degree of its oxygenation

The issue of ensuring the safe explosion of the spent orbital stages of a launch vehicle with propulsion rocket engine

Directory of Open Access Journals (Sweden)

Trushlyakov Valeriy I.

2017-01-01

Full Text Available A method for increasing the safe explosion of the spent orbital stages of a space launch vehicle (SLV with a propulsion rocket engine (PRE based on the gasification of unusable residues propellant and venting fuel tanks. For gasification and ventilation the hot gases used produced by combustion of the specially selected gas generating composition (GGC with a set of physical and chemical properties. Excluding the freezing of the drainage system on reset gasified products (residues propellant+pressurization gas+hot gases in the near-Earth space is achieved by selecting the physical-chemical characteristics of the GGC. Proposed steps to ensure rotation of gasified products due to dumping through the drainage system to ensure the most favorable conditions for propellant gasification residues. For example, a tank with liquid oxygen stays with the orbital spent second stage of the SLV “Zenit”, which shows the effectiveness of the proposed method.

Fiscal 2000 achievement report. Development of coal gas production technology for fuel cells (Research using pilot test facility - for public release); 2000 nendo seika hokokusho (Kokai you). Nenryo denchi you sekitan gas seizo gijutsu kaihatsu - Pilot shiken setsubi ni yoru kenkyu

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

For the development of a coal gasification furnace optimum for fuel cells, research and development was conducted of a coal gas production technology using the oxygen-blown coal gasification technology, and the fiscal 2000 results are put together. In the construction of the pilot test facility, part of the road in the site was constructed as continued from the preceding fiscal year. In the construction of the coal gasification facility, some of the devices were built, which were the coal feeding system, coal gasification furnace, heat recovery boiler, and the char recovery device, and some of the thus-built devices and procured devices were installed. In the study of the control of the operation of the oxygen-blown coal gasification system, the pilot test facility was divided into unit devices and, for each of the unit devices, detailed procedures for pre-start preparation, start, stop, and for the stop of accessorise were deliberated, and important operating steps were worked out. Timing charts were prepared for the operation of each of the facilities during plant start/stop operations. In the effort to deal with serious accidents, special operation procedures were studied and prepared on the case-by-case basis. (NEDO)

Preliminary experiments on dynamic biology of micro-organisms to avoid any specific full-blown syndrome on humans

Science.gov (United States)

Meer, Sneer

2002-06-01

The aim of this paper is to apply an efficient system to detect, identify and quicken suppression of any dangerous micro-organism which threatens the health of the human body in any form. It is well known that some specimens of this kind of possess a specific energy related to their speed of division, toxin emissions and high-powered interaction with human and animal cells which have the capacity to provide certain deadly full-blown syndromes. Many problems relating to the above-mentioned properties have not been clarified to date, and it is vital to find a rapid and valid reply as soon as possible. Inter-disciplinary sciences directed us to start some experiments to solve such problems, considering that the human body is dotted with a multiple interactive system of energy release, a fact which can explain the source of the micro-organism's energy also, for their necessity to manifest their deadly pathology. From practical preliminary experiments with some micro-mechanical systems using light-microscopy, connected to video TV Recorder System, one obtains optical enlarged TV images of certain processes which indicated the right way towards our crucial target; ie: the preparation of safe vaccines and safe medicines. This will constitute a basic system to a void deadly manifestations of dangerous micro-organisms and/or even regular infections on earth and in space, a system which will probably be applied at the ISS Space Station and other future actions in space in long and very long flights. We look forward to applying this system of dynamic biology towards preparation of a real and valid vaccine(s) against HIV virus on AIDS diseases.

Theory and development of fluorescence-based optochemical oxygen sensors: oxygen optodes.

Science.gov (United States)

Opitz, N; Lübbers, D W

1987-01-01

As the preceding considerations concerning the physical and technical features of oxygen optodes have demonstrated, fluorescence-based optochemical oxygen sensors possess certain advantages and peculiarities compared to conventionally applied electrochemical sensors such as polarographic oxygen electrodes. First, in contrast to oxygen electrodes, oxygen measurements with oxygen optodes do not suffer from distortions caused by the reference electrodes. In addition, because of the polarographic process, platinum electrodes continuously consume oxygen, which falsifies the results, especially when small sample volumes or long-term measurements, or both, are involved, whereas the sensor layer of oxygen optodes must only be equilibrated. Moreover, the surface of the platinum wire has to be catalytically clean in order to obtain a plateau of the polarogram and, consequently, to achieve a low rest current at zero PO2. Unfortunately, the demand for catalytically clean platinum surfaces turns out to be rather critical, since surface contamination occurs even with membranized electrodes, resulting in the well-known phenomenon of "electrode poisoning." The question of the specificity of oxygen electrodes also must be considered. In this context, CO2 and halothane may interfere with oxygen measurements, whereas fluorescence quenching is unaffected by CO2 and halothane affects the measurements only slightly, depending on the special indicator used. Furthermore, because of the flow dependence, oxygen measurements with the oxygen electrode show a distinct "stirring effect" caused by the turbulence in front of the electrode, which disturbs the diffusion field. Because of the completely different physical principle of fluorescence optical sensors, such influences are not observed with oxygen optodes. In addition, isolation and shielding of electrical circuits found in electrodes are not necessary for optodes. Furthermore, the sensitivity of oxygen optodes can be tuned to the desired

Oxygen Therapy

Science.gov (United States)

... their breathing to dangerously low levels. Will I need oxygen when I sleep? Usually if you use supplemental oxygen during the ... your health care provider tells you you only need to use oxygen for exercise or sleep. Even if you feel “fine” off of your ...

Retinal Vessel Oxygen Saturation during 100% Oxygen Breathing in Healthy Individuals.

Directory of Open Access Journals (Sweden)

Olof Birna Olafsdottir

Full Text Available To detect how systemic hyperoxia affects oxygen saturation in retinal arterioles and venules in healthy individuals.Retinal vessel oxygen saturation was measured in 30 healthy individuals with a spectrophotometric retinal oximeter (Oxymap T1. Oximetry was performed during breathing of room air, 100% oxygen (10 minutes, 6L/min and then again room air (10 minutes recovery.Mean oxygen saturation rises modestly in retinal arterioles during 100% oxygen breathing (94.5%±3.8 vs. 92.0%±3.7% at baseline, p<0.0001 and dramatically in retinal venules (76.2%±8.0% vs. 51.3%±5.6%, p<0.0001. The arteriovenous difference decreased during 100% oxygen breathing (18.3%±9.0% vs. 40.7%±5.7%, p<0.0001. The mean diameter of arterioles decreased during 100% oxygen breathing compared to baseline (9.7±1.4 pixels vs. 10.3±1.3 pixels, p<0.0001 and the same applies to the mean venular diameter (11.4±1.2 pixels vs. 13.3±1.5 pixels, p<0.0001.Breathing 100% oxygen increases oxygen saturation in retinal arterioles and more so in venules and constricts them compared to baseline levels. The dramatic increase in oxygen saturation in venules reflects oxygen flow from the choroid and the unusual vascular anatomy and oxygen physiology of the eye.

Techno-Economic Analysis of Biofuels Production Based on Gasification

Energy Technology Data Exchange (ETDEWEB)

Swanson, R. M.; Platon, A.; Satrio, J. A.; Brown, R. C.; Hsu, D. D.

2010-11-01

This study compares capital and production costs of two biomass-to-liquid production plants based on gasification. The first biorefinery scenario is an oxygen-fed, low-temperature (870?C), non-slagging, fluidized bed gasifier. The second scenario is an oxygen-fed, high-temperature (1,300?C), slagging, entrained flow gasifier. Both are followed by catalytic Fischer-Tropsch synthesis and hydroprocessing to naphtha-range (gasoline blend stock) and distillate-range (diesel blend stock) liquid fractions. Process modeling software (Aspen Plus) is utilized to organize the mass and energy streams and cost estimation software is used to generate equipment costs. Economic analysis is performed to estimate the capital investment and operating costs. Results show that the total capital investment required for nth plant scenarios is $610 million and $500 million for high-temperature and low-temperature scenarios, respectively. Product value (PV) for the high-temperature and low-temperature scenarios is estimated to be $4.30 and $4.80 per gallon of gasoline equivalent (GGE), respectively, based on a feedstock cost of $75 per dry short ton. Sensitivity analysis is also performed on process and economic parameters. This analysis shows that total capital investment and feedstock cost are among the most influential parameters affecting the PV.

Amine-based post-combustion CO2 capture in air-blown IGCC systems with cold and hot gas clean-up

International Nuclear Information System (INIS)

Giuffrida, A.; Bonalumi, D.; Lozza, G.

2013-01-01

Highlights: • Hot fuel gas clean-up is a very favorable technology for IGCC concepts. • IGCC net efficiency reduces to 41.5% when realizing post-combustion CO 2 capture. • Complex IGCC layouts are necessary if exhaust gas recirculation is realized. • IGCC performance does not significantly vary with exhaust gas recirculation. - Abstract: This paper focuses on the thermodynamic performance of air-blown IGCC systems with post-combustion CO 2 capture by chemical absorption. Two IGCC technologies are investigated in order to evaluate two different strategies of coal-derived gas clean-up. After outlining the layouts of two power plants, the first with conventional cold gas clean-up and the second with hot gas clean-up, attention is paid to the CO 2 capture station and to issues related to exhaust gas recirculation in combined cycles. The results highlight that significant improvements in IGCC performance are possible if hot coal-derived gas clean-up is realized before the syngas fuels the combustion turbine, so the energy cost of CO 2 removal in an amine-based post-combustion mode is less strong. In particular, IGCC net efficiency as high as 41.5% is calculated, showing an interesting potential if compared to the one of IGCC systems with pre-combustion CO 2 capture. Thermodynamic effects of exhaust gas recirculation are investigated as well, even though IGCC performance does not significantly vary against a more complicated plant layout

Oxidation of carbon based first wall materials of ITER

International Nuclear Information System (INIS)

Moormann, R.R.M.; Hinssen, H.K.; Wu, C.H.

2001-01-01

The safety relevance of oxidation reactions on carbon materials in fusion reactors is discussed. Because tritium codeposited in ITER will probably exceed tolerable limits, countermeasures have to be developed: In this paper ozone is tested as oxidising agent for removal of codeposited layers on thick a-C:D-flakes from TEXTOR. In preceeding experiments the advantageous features of using ozonised air instead of ozonised oxygen, reported in literature for reactions with graphite, is not found for nuclear grade graphite. At 185 deg. C = 458 K ozone (0.8-3.4 vol-% in oxygen) is able to gasify the carbon content of these flakes with initial rates, comparable to initial rates in oxygen (21 kPa) for the same material at >200K higher temperatures. The layer reduction rate in ozone drops with increasing burn-off rapidly from about 0.9-2.0 μm/h to 0.20-0.25 μm/h, but in oxygen it drops to zero for all temperatures ≤ 450 deg. C = 723 K, before carbon is completely gasified. Altogether, ozone seems to be a promising oxidising agent for removal of codeposited layers, but further studies are necessary with respect to rate dependence on temperature and ozone concentration even on other kinds of codeposited layers. Further on, the optimum reaction temperature considering the limited thermal stability of ozone has to be found out and studies on the general reaction mechanism have to be done. Besides these examinations on codeposited layers, a short overview on the status of our oxidation studies on different types of fusion relevant C-based materials is given; open problems in this field are outlined. (author)

International Seminar on Gasification 2008

Energy Technology Data Exchange (ETDEWEB)

Held, Joergen [ed.

2008-11-15

results in a product gas free of nitrogen and hence suitable for production of biomethane. The concept has been proven at the Guessing plant using a slip-stream but still we are awaiting the first commercial plant that produce biomethane suitable as vehicle fuel or for grid injection. Several demonstration projects are related to air-blown gasification and CHP production. The two-stage Viking gasifier developed at Technical University of Denmark produces a gas with low tar content (<5 mg/Nm3) suitable for combined heat and power production where a gas engine is used for the electricity production. The 70 kW{sub th} pilot plant has an electric efficiency of 25 %. With a scale-up to 0.2-2 MW{sub e} and improved internal heat recovery an electric efficiency of >37 % is expected. In Skive, Denmark, biomass gasification in a 20 MW{sub th} gasifier based on technology developed at GTI, USA and commercialized by Carbona, Finland is demonstrated. The total investment cost is 30 million Euro. Expected pay-back time is approx. 10 years. The project is delayed and the official opening is planned to April 2009. The delay reflects the inherent uncertainty related to large-scale demonstration of new technology. There are several other demonstrations related to biomass gasification and gas cleaning on their way and the field of gasification seems to experience a renaissance. Gas engines utilizing gasified biomass are commercially available. GE Jenbacher has installed gas engines in many biomass gasification plants in Europe. The accumulated hours of operation for the gas engines well exceed 100,000 hours. The plants with installed gas engines span over different gasification technologies (e.g. fixed bed - updraft, fixed bed - down draft and indirect gasification) and different gas compositions with lower heating values ranging from 5.4 MJ/Nm3 to 10.5 MJ/Nm3. High CO content in the gas results in high CO emissions from the gas engine which calls for exhaust gas after-treatment. To avoid

Oxygen-Partial-Pressure Sensor for Aircraft Oxygen Mask

Science.gov (United States)

Kelly, Mark; Pettit, Donald

2003-01-01

A device that generates an alarm when the partial pressure of oxygen decreases to less than a preset level has been developed to help prevent hypoxia in a pilot or other crewmember of a military or other high-performance aircraft. Loss of oxygen partial pressure can be caused by poor fit of the mask or failure of a hose or other component of an oxygen distribution system. The deleterious physical and mental effects of hypoxia cause the loss of a military aircraft and crew every few years. The device is installed in the crewmember s oxygen mask and is powered via communication wiring already present in all such oxygen masks. The device (see figure) includes an electrochemical sensor, the output potential of which is proportional to the partial pressure of oxygen. The output of the sensor is amplified and fed to the input of a comparator circuit. A reference potential that corresponds to the amplified sensor output at the alarm oxygen-partial-pressure level is fed to the second input of the comparator. When the sensed partial pressure of oxygen falls below the minimum acceptable level, the output of the comparator goes from the low state (a few millivolts) to the high state (near the supply potential, which is typically 6.8 V for microphone power). The switching of the comparator output to the high state triggers a tactile alarm in the form of a vibration in the mask, generated by a small 1.3-Vdc pager motor spinning an eccentric mass at a rate between 8,000 and 10,000 rpm. The sensation of the mask vibrating against the crewmember s nose is very effective at alerting the crewmember, who may already be groggy from hypoxia and is immersed in an environment that is saturated with visual cues and sounds. Indeed, the sensation is one of rudeness, but such rudeness could be what is needed to stimulate the crewmember to take corrective action in a life-threatening situation.

Synthetic fuel production using Texas lignite and a very high temperature reactor for process heat

International Nuclear Information System (INIS)

Ross, M.A.; Klein, D.E.

1982-01-01

Two approaches for synthetic fuel production from coal are studied using Texas lignite as the feedstock. First, the gasification and liquefaction of coal are accomplished using Lurgi gasifiers and Fischer-Tropsch synthesis. A 50 000 barrel/day facility, consuming 13.7 million tonne/yr (15.1 million ton/yr) of lignite, is considered. Second, a nuclear-assisted coal conversion approach is studied using a very high temperature gas-cooled reactor with a modified Lurgi gasifier and Fischer-Tropsch synthesis. The nuclear-assisted approach resulted in a 35% reduction in coal consumption. In addition, process steam consumption was reduced by one-half and the oxygen plants were eliminated in the nuclear assisted process. Both approaches resulted in a synthetic oil price higher than the March 1980 imported price of $29.65 per barrel: $36.15 for the lignite-only process and $35.16 for the nuclear-assisted process. No tax advantage was assumed for either process and the utility financing method was used for both economic calculations

Release of chlorine from biomass at gasification conditions

Energy Technology Data Exchange (ETDEWEB)

Bjoerkman, E.; Stroemberg, B. [TPS Termiska Processer AB, Nykoeping (Sweden)

1997-05-01

The objective of the project was to investigate the influence of different gasifying atmospheres on the release of chlorine from biomass during gasification conditions. Furthermore, the purpose was also to try and identify the formed chloro compounds. The results showed that O{sub 2}, H{sub 2}O and CO{sub 2} had negligible effect on the chlorine release at temperatures under 700 deg C. At temperatures above 800 deg C the reactivity towards CO{sub 2} increased and could be seen as higher chlorine release and less solid residue. No chloro organic compounds (aliphatic one to six carbons or aromatic one to two rings) could be detected in the tar or the fuel gas produced during pyrolysis/gasifying. On the other hand, comparable amounts of chlorinated benzenes were found in the cooling section during combustion of lucerne and of synthetic waste, indicating that oxygen is essential for chlorination reactions. 11 refs, 4 figs, 1 tab

Release of chlorine from biomass at gasification conditions

International Nuclear Information System (INIS)

Bjoerkman, E.; Stroemberg, B.

1997-05-01

The objective of the project was to investigate the influence of different gasifying atmospheres on the release of chlorine from biomass during gasification conditions. Furthermore, the purpose was also to try and identify the formed chloro compounds. The results showed that O 2 , H 2 O and CO 2 had negligible effect on the chlorine release at temperatures under 700 deg C. At temperatures above 800 deg C the reactivity towards CO 2 increased and could be seen as higher chlorine release and less solid residue. No chloro organic compounds (aliphatic one to six carbons or aromatic one to two rings) could be detected in the tar or the fuel gas produced during pyrolysis/gasifying. On the other hand, comparable amounts of chlorinated benzenes were found in the cooling section during combustion of lucerne and of synthetic waste, indicating that oxygen is essential for chlorination reactions. 11 refs, 4 figs, 1 tab

Blown Away

Science.gov (United States)

Scott, Alan

2014-01-01

On Aug. 13, 2011, at 8:45 p.m. country music fans were eagerly awaiting the band Sugarland to make its entry onto the main stage at the Indiana State Fairgrounds. Also competing for the fans' attention was an approaching storm. Sugarland never made their entrance. At 8:49 p.m. the stage rigging was hit by 59 mile/h (94 km/h) winds causing it to…

Blown Away.

Science.gov (United States)

Harrington-Lueker, Donna

1992-01-01

The number of students killed or injured by gunfire while at schools is increasing. The National Rifle Association, the nation's powerful gun lobby, has a gun safety program; however, children's advocates say stricter gun-control laws are necessary. Briefly cites 24 gun incidents and describes 4 semiautomatic pistols that were among the firearms…

Aviary heating: control of air temperature heated by a set biomass gasifier-combustor in a co-current flow, using a frequency inverter; Aquecimento de aviarios: controle da temperatura do ar aquecido por um conjunto gaseificador-combustor de biomassa de fluxo concorrente, utilizando um inversor de frequencia

Energy Technology Data Exchange (ETDEWEB)

Santos, William Rosario dos [Universidade Presidente Antonio Carlos (UNIPAC), Ponte Nova, MG (Brazil); Silva, Jadir Nogueira; Oliveira Filho, Delly; Martins, Marcio Aredes; Oliveira, Jofran Luiz de [Universidade Federal de Vicosa (UFV), MG (Brazil)], Emails: jadir@ufv.br, delly@ufv.br, aredes@ufv.br, jofran.oliveira@ufv.br

2009-07-01

One of the problems with using the gasifier for heating purposes in poultry facilities is the waste of energy during the day, once the equipment does not have control of the thermal and power generated. During this period, the difference in temperature between the air and the standard for the birds inside the building is lower than when compared with the nocturnal period. During the day, the temperature inside the poultry house is controlled by curtains, which occurs without diminishing the biomass burning. Another way to control the temperature is the shutdown of the system, which requires the constant attention of the operator. In this way, there is a potential for energy savings if the thermal power could be controlled according to the demand, which can be represented by the temperature gradient. The purpose of this study was to control the temperature of exhaustion air from a set combustor-gasifier (down draft), based on the model developed by Martin et al. (2006), through the control of speed of the fan engine and also controlling the flow contributions of primary and secondary air in the combustor. The experiment was carried out in the Energy and Pre-processing of Agricultural Products areas, at the Department of Agricultural Engineering - Federal University of Vicosa. (author)

Density functional theory study the effects of oxygen-containing functional groups on oxygen molecules and oxygen atoms adsorbed on carbonaceous materials.

Science.gov (United States)

Qi, Xuejun; Song, Wenwu; Shi, Jianwei

2017-01-01

Density functional theory was used to study the effects of different types of oxygen-containing functional groups on the adsorption of oxygen molecules and single active oxygen atoms on carbonaceous materials. During gasification or combustion reactions of carbonaceous materials, oxygen-containing functional groups such as hydroxyl(-OH), carbonyl(-CO), quinone(-O), and carboxyl(-COOH) are often present on the edge of graphite and can affect graphite's chemical properties. When oxygen-containing functional groups appear on a graphite surface, the oxygen molecules are strongly adsorbed onto the surface to form a four-member ring structure. At the same time, the O-O bond is greatly weakened and easily broken. The adsorption energy value indicates that the adsorption of oxygen molecules changes from physisorption to chemisorption for oxygen-containing functional groups on the edge of a graphite surface. In addition, our results indicate that the adsorption energy depends on the type of oxygen-containing functional group. When a single active oxygen atom is adsorbed on the bridge site of graphite, it gives rise to a stable epoxy structure. Epoxy can cause deformation of the graphite lattice due to the transition of graphite from sp2 to sp3 after the addition of an oxygen atom. For quinone group on the edge of graphite, oxygen atoms react with carbon atoms to form the precursor of CO2. Similarly, the single active oxygen atoms of carbonyl groups can interact with edge carbon atoms to form the precursor of CO2. The results show that oxygen-containing functional groups on graphite surfaces enhance the activity of graphite, which promotes adsorption on the graphite surface.

Improvement of producer gas of Palm Oil Empty Fruit Bunch in a 50 kg/ hr prototype down draft gasifier by palletization

International Nuclear Information System (INIS)

Kerdsuwan, Somrat; Cherdphong, Somphot; Uthaikiattikul, Tada

2010-01-01

The main residue from palm oil industry is Palm Oil Empty Fruit Bunch (PEFB) which was considered as null-waste, can be rethinking and used as renewable or alternative fuel, since there is still hiding energy storage within. The proper technology for converting PEFB to renewable energy carrier is gasification technology. The gasification process of PEFB with and without feedstock preparation was investigated and compared in order to improve the efficiency of gasification process by pelletizing PEFB and to characterize the gasification reaction of pelletized PEFB. As received PEFB is solar dried and pelletized in a cylindrical form. The proximate and ultimate analysis of pelletized PEFB is investigated. Thereafter, the gasification process of as-received PEFB and pelletized PEFB was carried out in a 50 kg/ hr prototype down draft gasifier with varying the operating conditions, to characterize the gasification behavior of pelletized PEFB. From the experiments, the feedstock preparation, in this case pelletizing, can improve the performance of PEFB gasification. The results of experiment reveals that the heating value of producer gas and cold gas efficiency increases from 5.18 MJ/ Nm 3 for PEFB gasification without preparation to 6.5 MJ/ Nm 3 with feedstock preparation and from 61.72% to 79.73% respectively. (author)

Oxygen permeation through oxygen ion oxide-noble metal dual phase composites

NARCIS (Netherlands)

Chen, C.S.; Chen, C.S.; Kruidhof, H.; Bouwmeester, Henricus J.M.; Verweij, H.; Burggraaf, Anthonie; Burggraaf, A.J.

1996-01-01

Oxygen permeation behaviour of three composites, yttria-stabilized zirconia-palladium, erbia-stabilized bismuth oxidenoble metal (silver, gold) was studied. Oxygen permeation measurements were performed under controlled oxygen pressure gradients at elevated temperatures. Air was supplied at one side

Liquid Oxygen/Liquid Methane Integrated Power and Propulsion

Science.gov (United States)

Banker, Brian; Ryan, Abigail

2016-01-01

The proposed paper will cover ongoing work at the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) on integrated power and propulsion for advanced human exploration. Specifically, it will present findings of the integrated design, testing, and operational challenges of a liquid oxygen / liquid methane (LOx/LCH4) propulsion brassboard and Solid Oxide Fuel Cell (SOFC) system. Human-Mars architectures point to an oxygen-methane economy utilizing common commodities, scavenged from the planetary atmosphere and soil via In-Situ Resource Utilization (ISRU), and common commodities across sub-systems. Due to the enormous mass gear-ratio required for human exploration beyond low-earth orbit, (for every 1 kg of payload landed on Mars, 226 kg will be required on Earth) increasing commonality between spacecraft subsystems such as power and propulsion can result in tremendous launch mass and volume savings. Historically, propulsion and fuel cell power subsystems have had little interaction outside of the generation (fuel cell) and consumption (propulsion) of electrical power. This was largely due to a mismatch in preferred commodities (hypergolics for propulsion; oxygen & hydrogen for fuel cells). Although this stove-piped approach benefits from simplicity in the design process, it means each subsystem has its own tanks, pressurization system, fluid feed system, etc. increasing overall spacecraft mass and volume. A liquid oxygen / liquid methane commodities architecture across propulsion and power subsystems would enable the use of common tankage and associated pressurization and commodity delivery hardware for both. Furthermore, a spacecraft utilizing integrated power and propulsion could use propellant residuals - propellant which could not be expelled from the tank near depletion due to hydrodynamic considerations caused by large flow demands of a rocket engine - to generate power after all propulsive maneuvers are complete thus utilizing

The oxygen effect and adaptive response of cells. Report 3. Simulation of respiratory oxygenation and oxygen permeability of cells

International Nuclear Information System (INIS)

Ehpshtejn, I.M.

1978-01-01

Variations in the oxygen concentration in extracellural [O 2 ] 0 and intracellular [Osub(2)]sub(i) media of cells small in size (d = 2 ] 0 - t-curves). It is shown that the Value of [Osub(2)]sub(i) may be expressed by four variants of its functional dependence: (a) on enzymic reaction of oxygen consumption, (b) on the order of reaction with respect to oxygen, (c) on physiological parameters of cells, and (d) on characteristic oxygen concentrations in the system. Items (c) and (d) are based on the postulated diffusion-kinetic model of oxygen consumption by an idealized cell of small size that consists of a drop of homogenous solution of the respiratory enzyme which is characterized by an equivalent Michaelis constant. The drop is enveloped in a uniform membrane that possesses a definite diffuse resistance to oxygen

Proterozoic atmospheric oxygen

DEFF Research Database (Denmark)

Canfield, Donald Eugene

2014-01-01

This article is concerned with the evolution of atmospheric oxygen concentrations through the Proterozoic Eon. In particular, this article will seek to place the history of atmospheric oxygenation through the Proterozoic Eon in the context of the evolving physical environment including the history...... of continental growth and volcanic outgassing, as well as biogeochemical processing of elements within the oceans. The author will seek to explore constraints on the history of oxygenation and understand which processes have regulated oxygen through this eon....

Gas flow calculation with a turbulence model in a packed bed; Ranryu model wo mochiita juten sonai no gas nagare no keisan

Energy Technology Data Exchange (ETDEWEB)

Takeda, K [Kawasaki Steel Corp., Tokyo (Japan); Lockwood, F

1996-06-01

For the rationalization of blast furnace operation, the gas flow in a packed bed is calculated using a turbulence model. For accurately determining the mixing of gasses, dispersion of particulates in a turbulence, turbulence diffusion, response rate, etc., in a packed bed, turbulence characteristics need be elucidated. For the calculation of combustion behavior of powdered coal blown into the blast furnace tuyere, in particular, the evaluation of gas turbulence behavior in the blow pipe and packed bed is indispensable. The dissipation rate of {kappa} has been defined from the mixing length Lm with the hydraulic diameter of the packed bed as its function and the turbulence energy ({kappa}), and now a {kappa}-Lm model is proposed, capable of evaluating the turbulence behavior in the packed bed. The parameters in the model may be determined using the actually measured values about diffusion behavior. The diffusion behavior of a tracer blown into the packed bed is simulated, and then agreement is found between the calculated values and measured values. Oxygen distribution under simplified raceway conditions is calculated. Once in the raceway, the radial concentration gradient of oxygen is much gentler suddenly, indicating the excellent mixture characteristics of the packed layer. 21 refs., 9 figs.

Fiscal 2001 achievement report. Development of coal gas production technology for fuel cells - Research using pilot test facility - for public release (Part 1 - Construction and test operation); 2001 nendo seika hokokusho (Kokai you). Nenryo denchi you sekitan gas seizo gijutsu kaihatsu - Pilot shiken setsubi ni yoru kenkyu (Sono 1 - Koji shiken unten hen)

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-03-01

For the development of a coal gasification furnace optimum for fuel cells, research and development was conducted of a coal gas production technology using the oxygen-blown coal gasification technology, and the fiscal 2001 results are put together. In the construction of the pilot test facility, work involved the road in the site, road illumination system installation in the site, and an unauthorized entry prevention system. In the construction of the coal gasification facility, work involved electrical instrumentation and painting for the coal feeding system, coal gasification furnace, heat recovery boiler, and so forth, and the installation of a series of devices was completed. In July following the completion, power was received and test operations were started, which included the operation of the coal gasification facility alone. Renting was started in August for the coal pretreatment facility, air separation facility, and the slag treatment device. In the study of the operation control technology for the oxygen-blown coal gasification furnace system, test operations were conducted based on the operating procedures prepared in the preceding fiscal year, which included a test operation performed for the pilot test facility alone. Parameters for equipment control obtained through the test operations, and improvements on operating steps carried out as required, were all reflected on the operating procedures. (NEDO)

Oxygen respiration rates of benthic foraminifera as measured with oxygen microsensors

DEFF Research Database (Denmark)

Geslin, E.; Risgaard-Petersen, N.; Lombard, Fabien

2011-01-01

of the foraminiferal specimens. The results show a wide range of oxygen respiration rates for the different species (from 0.09 to 5.27 nl cell−1 h−1) and a clear correlation with foraminiferal biovolume showed by the power law relationship: R = 3.98 10−3 BioVol0.88 where the oxygen respiration rate (R) is expressed......Oxygen respiration rates of benthic foraminifera are still badly known, mainly because they are difficult to measure. Oxygen respiration rates of seventeen species of benthic foraminifera were measured using microelectrodes and calculated on the basis of the oxygen fluxes measured in the vicinity...... groups (nematodes, copepods, ostracods, ciliates and flagellates) suggests that benthic foraminifera have a lower oxygen respiration rates per unit biovolume. The total contribution of benthic foraminifera to the aerobic mineralisation of organic matter is estimated for the studied areas. The results...

A Gibbs Energy Minimization Approach for Modeling of Chemical Reactions in a Basic Oxygen Furnace

Science.gov (United States)

Kruskopf, Ari; Visuri, Ville-Valtteri

2017-12-01

In modern steelmaking, the decarburization of hot metal is converted into steel primarily in converter processes, such as the basic oxygen furnace. The objective of this work was to develop a new mathematical model for top blown steel converter, which accounts for the complex reaction equilibria in the impact zone, also known as the hot spot, as well as the associated mass and heat transport. An in-house computer code of the model has been developed in Matlab. The main assumption of the model is that all reactions take place in a specified reaction zone. The mass transfer between the reaction volume, bulk slag, and metal determine the reaction rates for the species. The thermodynamic equilibrium is calculated using the partitioning of Gibbs energy (PGE) method. The activity model for the liquid metal is the unified interaction parameter model and for the liquid slag the modified quasichemical model (MQM). The MQM was validated by calculating iso-activity lines for the liquid slag components. The PGE method together with the MQM was validated by calculating liquidus lines for solid components. The results were compared with measurements from literature. The full chemical reaction model was validated by comparing the metal and slag compositions to measurements from industrial scale converter. The predictions were found to be in good agreement with the measured values. Furthermore, the accuracy of the model was found to compare favorably with the models proposed in the literature. The real-time capability of the proposed model was confirmed in test calculations.

A model for oxygen conservation associated with titration during pediatric oxygen therapy.

Directory of Open Access Journals (Sweden)

Grace Wu

Full Text Available Continuous oxygen treatment is essential for managing children with hypoxemia, but access to oxygen in low-resource countries remains problematic. Given the high burden of pneumonia in these countries and the fact that flow can be gradually reduced as therapy progresses, oxygen conservation through routine titration warrants exploration.To determine the amount of oxygen saved via titration during oxygen therapy for children with hypoxemic pneumonia.Based on published clinical data, we developed a model of oxygen flow rates needed to manage hypoxemia, assuming recommended flow rate at start of therapy, and comparing total oxygen used with routine titration every 3 minutes or once every 24 hours versus no titration.Titration every 3 minutes or every 24 hours provided oxygen savings estimated at 11.7% ± 5.1% and 8.1% ± 5.1% (average ± standard error of the mean, n = 3, respectively. For every 100 patients, 44 or 30 kiloliters would be saved-equivalent to 733 or 500 hours at 1 liter per minute.Ongoing titration can conserve oxygen, even performed once-daily. While clinical validation is necessary, these findings could provide incentive for the routine use of pulse oximeters for patient management, as well as further development of automated systems.

Report on diagnosis and survey on research cooperation in the research cooperation promotion project in fiscal 1994. Research cooperation on manufacturing clean fuel for consumer use from gasified coal gas / Research cooperation on a method for pulp manufacturing of low-pollution and energy saving type by using non-wood raw materials; 1994 nendo kenkyu kyoryoku suishin jigyo 'kenkyu kyoryoku shindan chosa' hokokusho. Sekitan gas ka gas kara no minseiyo clean nenryo seizo ni kansuru kenkyu kyoryoku / himokuzaikei genryo wo mochiita teikogai shoenegata pulp seizoho ni kansuru kenkyu kyoryoku

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-03-01

In solving the problems in developing technologies peculiar to developing countries, Japan will provide cooperation. This paper describes the achievements in diagnosis and survey in fiscal 1994. Development will be made on a manufacturing process for dimethylether (DME), a synthesizable and portable clean fuel, by using coal produced in China. Annual DME production of 10,000 tons will make it possible to supply 50,000 households with the fuel of one year consumption, whereas return on the construction investment and profit can be expected. At the Shanxi Coal Chemistry Research Institute, a 500 tons a year plant making DME from gasified coal gas is scheduled to begin operation. Development will be made on a pulp manufacturing technology in China, in which environmental pollution due to waste water is largely reduced, and operation cost is reduced. Application of the oxygen-alkaline evaporation and decomposition process developed in Japan will be considered, which uses non-wood raw material such as rice straw, wheat straw and megass). The raw materials are immersed continually in low-concentration alkaline solution, dehydrated, and then lignin is oxidized and decomposed by using oxygen in a continuous oxidation reactor to make the material into pulp. China uses non-wood materials as paper raw materials at 80%, whereas effects are expected in waste water pollution prevention, energy saving, resource saving and economics. (NEDO)

On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement

Energy Technology Data Exchange (ETDEWEB)

Kristie Cooper; Gary Pickrell; Anbo Wang

2005-11-01

This report summarizes technical progress April-September 2005 on the Phase II program ''On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement'', funded by the Federal Energy Technology Center of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The outcome of the first phase of this program was the selection of broadband polarimetric differential interferometry (BPDI) for further prototype instrumentation development. This approach is based on the measurement of the optical path difference (OPD) between two orthogonally polarized light beams in a single-crystal sapphire disk. The objective of this program is to bring the sensor technology, which has already been demonstrated in the laboratory, to a level where the sensor can be deployed in the harsh industrial environments and will become commercially viable. Due to the difficulties described on the last report, field testing of the BPDI system has not continued to date. However, we have developed an alternative high temperature sensing solution, which is described in this report. The sensing system will be installed and tested at TECO's Polk Power Station. Following a site visit in June 2005, our efforts have been focused on preparing for that field test, including he design of the sensor mechanical packaging, sensor electronics, the data transfer module, and the necessary software codes to accommodate this application.. We are currently ready to start sensor fabrication.

Dry piston coal feeder

Science.gov (United States)

Hathaway, Thomas J.; Bell, Jr., Harold S.

1979-01-01

This invention provides a solids feeder for feeding dry coal to a pressurized gasifier at elevated temperatures substantially without losing gas from the gasifier by providing a lock having a double-acting piston that feeds the coals into the gasifier, traps the gas from escaping, and expels the trapped gas back into the gasifier.

Artificial oxygen transport protein

Science.gov (United States)

Dutton, P. Leslie

2014-09-30

This invention provides heme-containing peptides capable of binding molecular oxygen at room temperature. These compounds may be useful in the absorption of molecular oxygen from molecular oxygen-containing atmospheres. Also included in the invention are methods for treating an oxygen transport deficiency in a mammal.

Aircraft Oxygen Generation

Science.gov (United States)

2012-02-01

An Oxygen Enriched Air System for the AV-8A Harrier (NADC-81198-60).” 70 Horch , T., et. al. “The F-16 Onboard Oxygen Generating System: Performance...Only and Safety Privileged). Horch , T., Miller, R., Bomar, J., Tedor, J., Holden, R., Ikels, K., & Lozano, P. (1983). The F-16 Onboard Oxygen

Oxygen enrichment incineration

International Nuclear Information System (INIS)

Kim, Jeong Guk; Yang, Hee Chul; Park, Geun Il; Kim, Joon Hyung

2000-10-01

Oxygen enriched combustion technology has recently been used in waste incineration. To apply the oxygen enrichment on alpha-bearing waste incineration, which is being developed, a state-of-an-art review has been performed. The use of oxygen or oxygen-enriched air instead of air in incineration would result in increase of combustion efficiency and capacity, and reduction of off-gas product. Especially, the off-gas could be reduced below a quarter, which might reduce off-gas treatment facilities, and also increase an efficiency of off-gas treatment. However, the use of oxygen might also lead to local overheating and high nitrogen oxides (NOx) formation. To overcome these problems, an application of low NOx oxy-fuel burner and recycling of a part of off-gas to combustion chamber have been suggested

Oxygen enrichment incineration

Energy Technology Data Exchange (ETDEWEB)

Kim, Jeong Guk; Yang, Hee Chul; Park, Geun Il; Kim, Joon Hyung

2000-10-01

Oxygen enriched combustion technology has recently been used in waste incineration. To apply the oxygen enrichment on alpha-bearing waste incineration, which is being developed, a state-of-an-art review has been performed. The use of oxygen or oxygen-enriched air instead of air in incineration would result in increase of combustion efficiency and capacity, and reduction of off-gas product. Especially, the off-gas could be reduced below a quarter, which might reduce off-gas treatment facilities, and also increase an efficiency of off-gas treatment. However, the use of oxygen might also lead to local overheating and high nitrogen oxides (NOx) formation. To overcome these problems, an application of low NOx oxy-fuel burner and recycling of a part of off-gas to combustion chamber have been suggested.

Hybrid Molten Bed Gasifier for High Hydrogen Syngas Production

Energy Technology Data Exchange (ETDEWEB)

Rue, David [Gas Technology Institute, Des Plaines, IL (United States)

2017-05-23

was stable over the full oxygen to fuel firing range (0.8 to 1.05 of fuel gas stoichiometry) and with all fuel gases (natural gas and two syngas compositions), with steam, and without steam. The lower Btu content of the syngases presented no combustion difficulties. The molten bed was stable throughout testing. The molten bed was easily established as a bed of molten glass. As the composition changed from glass cullet to cullet with slag, no instabilities were encountered. The bed temperature and product syngas temperature remained stable throughout testing, demonstrating that the bed serves as a good heat sink for the gasification process. Product syngas temperature measured above the bed was stable at ~1600ºF. Testing found that syngas quality measured as H₂/CO ratio increased with decreasing oxygen to fuel gas stoichiometric ratio, higher steam to inlet carbon ratio, higher temperature, and syngas compared with natural gas. The highest H₂/CO ratios achieved were in the range of 0.70 to 0.78. These values are well below the targets of 1.5 to 2.0 that were expected and were predicted by modeling. The team, however, is encouraged that the HMB process can and will achieve H₂/CO ratios up to 2.0. Changes needed include direct injection of coal into the molten bed of slag to prevent coal particle bypass into the product gas stream, elevation of the molten bed temperature to approximately 2500ºF, and further decrease of the oxygen to fuel gas ratio to well below the 0.85 minimum ratio used in the testing in this project.

Effects of oxygen concentration on atmospheric pressure dielectric barrier discharge in Argon-Oxygen Mixture

Science.gov (United States)

Li, Xuechun; Li, Dian; Wang, Younian

2016-09-01

A dielectric barrier discharge (DBD) can generate a low-temperature plasma easily at atmospheric pressure and has been investigated for applications in trials in cancer therapy, sterilization, air pollution control, etc. It has been confirmed that reactive oxygen species (ROS) play a key role in the processes. In this work, we use a fluid model to simulate the plasma characteristics for DBD in argon-oxygen mixture. The effects of oxygen concentration on the plasma characteristics have been discussed. The evolution mechanism of ROS has been systematically analyzed. It was found that the ground state oxygen atoms and oxygen molecular ions are the dominated oxygen species under the considered oxygen concentrations. With the oxygen concentration increasing, the densities of electrons, argon atomic ions, resonance state argon atoms, metastable state argon atoms and excited state argon atoms all show a trend of decline. The oxygen molecular ions density is high and little influenced by the oxygen concentration. Ground state oxygen atoms density tends to increase before falling. The ozone density increases significantly. Increasing the oxygen concentration, the discharge mode begins to change gradually from the glow discharge mode to Townsend discharge mode. Project supported by the National Natural Science Foundation of China (Grant No. 11175034).

Limitations of potentiometric oxygen sensors operating at low oxygen levels

DEFF Research Database (Denmark)

Lund, Anders; Jacobsen, Torben; Hansen, Karin Vels

2011-01-01

The electrochemical processes that limit the range of oxygen partial pressures in which potentiometric oxygen sensors can be used, were analysed using a theoretical and an experimental approach. Electrochemical impedance spectroscopy was performed on porous Pt/yttria stabilised zirconia (YSZ......) electrodes between 10−6 and 0.2 bar and at temperatures between 500 and 950 °C. The flow of oxide ions and electron holes through a sensor cell, with a YSZ electrolyte, were calculated under similar conditions. The oxygen permeation of the sensor cell was insignificant at an oxygen partial pressure of 10......−6 bar for an inlet flow rate higher than 2 L h−1 between 600 and 800 °C. The polarisation resistance measured between 10−6 and 10−4 bar was found to be inversely proportional to the oxygen partial pressure, nearly temperature independent and inversely proportional to the inlet gas flow rate, which shows...

Plasma gasification of refuse derived fuel in a single-stage system using different gasifying agents.

Science.gov (United States)

Agon, N; Hrabovský, M; Chumak, O; Hlína, M; Kopecký, V; Masláni, A; Bosmans, A; Helsen, L; Skoblja, S; Van Oost, G; Vierendeels, J

2016-01-01

The renewable evolution in the energy industry and the depletion of natural resources are putting pressure on the waste industry to shift towards flexible treatment technologies with efficient materials and/or energy recovery. In this context, a thermochemical conversion method of recent interest is plasma gasification, which is capable of producing syngas from a wide variety of waste streams. The produced syngas can be valorized for both energetic (heat and/or electricity) and chemical (ammonia, hydrogen or liquid hydrocarbons) end-purposes. This paper evaluates the performance of experiments on a single-stage plasma gasification system for the treatment of refuse-derived fuel (RDF) from excavated waste. A comparative analysis of the syngas characteristics and process yields was done for seven cases with different types of gasifying agents (CO2+O2, H2O, CO2+H2O and O2+H2O). The syngas compositions were compared to the thermodynamic equilibrium compositions and the performance of the single-stage plasma gasification of RDF was compared to that of similar experiments with biomass and to the performance of a two-stage plasma gasification process with RDF. The temperature range of the experiment was from 1400 to 1600 K and for all cases, a medium calorific value syngas was produced with lower heating values up to 10.9 MJ/Nm(3), low levels of tar, high levels of CO and H2 and which composition was in good agreement to the equilibrium composition. The carbon conversion efficiency ranged from 80% to 100% and maximum cold gas efficiency and mechanical gasification efficiency of respectively 56% and 95%, were registered. Overall, the treatment of RDF proved to be less performant than that of biomass in the same system. Compared to a two-stage plasma gasification system, the produced syngas from the single-stage reactor showed more favourable characteristics, while the recovery of the solid residue as a vitrified slag is an advantage of the two-stage set-up. Copyright �

Nature of oxygen donors and radiation defects in oxygen-doped germanium

International Nuclear Information System (INIS)

Fukuoka, Noboru; Atobe, Kozo; Honda, Makoto; Matsuda, Koji.

1991-01-01

The nature of oxygen donors and radiation defects in oxygen-doped germanium were studied through measurements of the infrared absorption spectrum, deep level transient spectroscopy spectrum and carrier concentration. It is revealed that a new donor is not formed in oxygen-doped germanium. An A-center (interstitial oxygen-vacancy pair) forms a complex with a thermal donor in its annealing stage at 60degC-140degC. The introduction rate of defects by 1.5 MeV electron irradiation was enhanced in thermal-donor-doped samples. (author)

Intraportal islet oxygenation.

Science.gov (United States)

Suszynski, Thomas M; Avgoustiniatos, Efstathios S; Papas, Klearchos K

2014-05-01

Islet transplantation (IT) is a promising therapy for the treatment of diabetes. The large number of islets required to achieve insulin independence limit its cost-effectiveness and the number of patients who can be treated. It is believed that >50% of islets are lost in the immediate post-IT period. Poor oxygenation in the early post-IT period is recognized as a possible reason for islet loss and dysfunction but has not been extensively studied. Several key variables affect oxygenation in this setting, including (1) local oxygen partial pressure (pO(2)), (2) islet oxygen consumption, (3) islet size (diameter, D), and (4) presence or absence of thrombosis on the islet surface. We discuss implications of oxygen-limiting conditions on intraportal islet viability and function. Of the 4 key variables, the islet size appears to be the most important determinant of the anoxic and nonfunctional islet volume fractions. Similarly, the effect of thrombus formation on the islet surface may be substantial. At the University of Minnesota, average size distribution data from clinical alloislet preparations (n = 10) indicate that >150-µm D islets account for only ~30% of the total islet number, but >85% of the total islet volume. This suggests that improved oxygen supply to the islets may have a profound impact on islet survivability and function since most of the β-cell volume is within large islets which are most susceptible to oxygen-limiting conditions. The assumption that the liver is a suitable islet transplant site from the standpoint of oxygenation should be reconsidered. © 2014 Diabetes Technology Society.

[Correlation between the inspired fraction of oxygen, maternal partial oxygen pressure, and fetal partial oxygen pressure during cesarean section of normal pregnancies].

Science.gov (United States)

Castro, Carlos Henrique Viana de; Cruvinel, Marcos Guilherme Cunha; Carneiro, Fabiano Soares; Silva, Yerkes Pereira; Cabral, Antônio Carlos Vieira; Bessa, Roberto Cardoso

2009-01-01

Despite changes in pulmonary function, maternal oxygenation is maintained during obstetric regional blocks. But in those situations, the administration of supplementary oxygen to parturients is a common practice. Good fetal oxygenation is the main justification; however, this has not been proven. The objective of this randomized, prospective study was to test the hypothesis of whether maternal hyperoxia is correlated with an increase in fetal gasometric parameters in elective cesarean sections. Arterial blood gases of 20 parturients undergoing spinal block with different inspired fractions of oxygen were evaluated and correlated with fetal arterial blood gases. An increase in maternal inspired fraction of oxygen did not show any correlation with an increase of fetal partial oxygen pressure. Induction of maternal hyperoxia by the administration of supplementary oxygen did not increase fetal partial oxygen pressure. Fetal gasometric parameters did not change even when maternal parameters changed, induced by hyperoxia, during cesarean section under spinal block.

Dynamic simulation of a low-temperature rectification Column as part of an IGCC power plant

Energy Technology Data Exchange (ETDEWEB)

Hanke, R. [Leipzig University of Applied Sciences, Department of Mechanical and Energy Engineering, P.O. Box 300066, D-04251 Leipzig (Germany); Hannemann, F. [Siemens AG - Power Generation, PG CTET, P.O. Box 3220, D-91050 Erlangen (Germany); Sundmacher, K. [Max Planck Institute of Dynamics of Complex Technical Systems, Sandtorstrasse 1, D-39106 Magdeburg (Germany); Otto-von-Guericke University Magdeburg, Faculty of Process and Systems Engineering, P.O. Box 4120, D-39106 Magdeburg (Germany)

2003-11-01

IGCC plants offer the opportunity to utilize fossil energy sources, like coal or heavy refinery residues, to satisfy increasing energy demand while considering strict environmental constraints. Such a plant consists of a combined power cycle, a fuel gasifier with downstream fuel gas conditioning and an air separation unit (ASU), where the oxygen required for gasification is produced. The low-temperature rectification column as the core of the ASU strongly affects the transient behavior of the system. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

Coenzyme Q10 prevented full blown splenomegaly and decreased melarsoprol-induced reactive encephalopathy in mice infected with Trypanosoma brucei rhodesiense

Directory of Open Access Journals (Sweden)

James Nyabuga Nyariki

2015-03-01

Full Text Available Objective: To establish the modulatory effects of coenzyme Q10 on experimental trypanosome infections in mice and evaluate the risk of occurrence and severity of melarsoprol-induced post treatment reactive encephalopathy (PTRE. Methods: Female Swiss white mice were orally administered with 200 mg/kg of coenzyme Q10 after which they were intraperitoneally inoculated with Trypanasoma brucei rhodesiense (T. b. rhodesiense. The resultant infection was allowed to develop and simulate all phases of human African trypanosomiasis and PTRE. Parasitaemia development, packed cell volume, haematological and pathological changes were determined. Results: A histological study in the brain tissue of T. b. rhodesiense infected mice demonstrated neuroinflammatory pathology which was highly amplified in the PTRE-induced groups. A prominent reduction in the severity of the neuroinflammatory response was detected when coenzyme-Q10 was administered. Furthermore, the mean tissue weight of spleen to body ratio in coenzyme Q10 supplemented group was significantly (P<0.05 different compared to un-supplemented groups, and clearly indicated that coenzyme Q10 prevented full blown splenomegaly pathogenesis by T. b. rhodesiense. A significant (P<0.05 increase in hemoglobin levels and red blood cells was observed in coenzyme Q10 mice compared to those infected and un-supplemented with coenzyme Q10. Conclusions: The capacity of coenzyme Q10 to alter the pathogenesis of T. b. rhodesiense infection in mice and following treatment with melarsoprol, may find application by rendering humans and animals less susceptible to deleterious effects of trypanosome infection such as splenomegaly and melarsoprol-induced PTRE and neurotoxicity.

Developments in modelling and simulation of coal gasification

Energy Technology Data Exchange (ETDEWEB)

NONE

2014-02-01

In recent years, the considerable increase in the price of crude oil and natural gas and concerns about their security of supply focused attention on whether fuel for power production and feedstocks for the chemical industry could be obtained from the gasification of coal. The need to reduce greenhouse gas emissions has enhanced the prospects of power generation from Integrated Gasification Combined Cycle (IGCC) plant. However, the higher capital costs and concerns about reliability and availability of IGCC plant have limited their market penetration. The coal gasifier has been a significant source of operational issues. A thorough understanding of the processes occurring in a gasifier is essential both for addressing existing causes of gasifier unavailability and improving designs for the future. Many complex processes take place in a gasifier and developing models of gasifiers results in a greater insight into these processes. Computational models in conjunction with plant data can be used to evaluate gasifier operation, solve operational problems, probe new designs and provide performance data for commercial scale-up. This report has surveyed models which are currently available for modelling gasifiers. The report contains a brief description of the three types of gasifiers which are most commonly used. The models available for each type of gasifier are considered. Insight gained by modelling has advanced the design of gasifiers and can improve gasifier performance. In some cases, the results have been compared with plant data and it has been possible to choose model inputs to give reasonable fit with the measured data. However, there are fewer examples where modelling has directly solved operational problems.

Yeast alter micro-oxygenation of wine: oxygen consumption and aldehyde production.

Science.gov (United States)

Han, Guomin; Webb, Michael R; Richter, Chandra; Parsons, Jessica; Waterhouse, Andrew L

2017-08-01

Micro-oxygenation (MOx) is a common winemaking treatment used to improve red wine color development and diminish vegetal aroma, amongst other effects. It is commonly applied to wine immediately after yeast fermentation (phase 1) or later, during aging (phase 2). Although most winemakers avoid MOx during malolactic (ML) fermentation, it is often not possible to avoid because ML bacteria are often present during phase 1 MOx treatment. We investigated the effect of common yeast and bacteria on the outcome of micro-oxygenation. Compared to sterile filtered wine, Saccharomyces cerevisiae inoculation significantly increased oxygen consumption, keeping dissolved oxygen in wine below 30 µg L -1 during micro-oxygenation, whereas Oenococcus oeni inoculation was not associated with a significant impact on the concentration of dissolved oxygen. The unfiltered baseline wine also had both present, although with much higher populations of bacteria and consumed oxygen. The yeast-treated wine yielded much higher levels of acetaldehyde, rising from 4.3 to 29 mg L -1 during micro-oxygenation, whereas no significant difference was found between the bacteria-treated wine and the filtered control. The unfiltered wine exhibited rapid oxygen consumption but no additional acetaldehyde, as well as reduced pyruvate. Analysis of the acetaldehyde-glycerol acetal levels showed a good correlation with acetaldehyde concentrations. The production of acetaldehyde is a key outcome of MOx and it is dramatically increased in the presence of yeast, although it is possibly counteracted by the metabolism of O. oeni bacteria. Additional controlled experiments are necessary to clarify the interaction of yeast and bacteria during MOx treatments. Analysis of the glycerol acetals may be useful as a proxy for acetaldehyde levels. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Oxygen configurations in silica

International Nuclear Information System (INIS)

Chelikowsky, James R.; Chadi, D. J.; Binggeli, N.

2000-01-01

We propose a transition state for oxygen in silica. This state is produced by the insertion of an oxygen molecule into the Si-O-Si bond, i.e., it consists of producing a Si-O-O-O-Si bond. This state allows molecular oxygen diffusion in silica without breaking the molecular O 2 bond and it is energetically more stable than a peroxy configuration. This configuration may allow for exchange of molecular oxygen with the oxygen in the silica framework. (c) 2000 The American Physical Society

Oxygen transport by oxygen potential gradient in dense ceramic oxide membranes

Energy Technology Data Exchange (ETDEWEB)

Maiya, P.S.; Balachandran, U.; Dusek, J.T.; Mieville, R.L. [Argonne National Lab., IL (United States). Energy Technology Div.; Kleefisch, M.S.; Udovich, C.A. [Amoco Exploration/Production, Naperville, IL (United States)

1996-05-01

Numerous studies have been conducted in recent years on the partial oxidation of methane to synthesis gas (syngas: CO + H{sub 2}) with air as the oxidant. In partial oxidation, a mixed-oxide ceramic membrane selectively transports oxygen from the air; this transport is driven by the oxygen potential gradient. Of the several ceramic materials the authors have tested, a mixed oxide based on the Sr-Fe-Co-O system has been found to be very attractive. Extensive oxygen permeability data have been obtained for this material in methane conversion experiments carried out in a reactor. The data have been analyzed by a transport equation based on the phenomenological theory of diffusion under oxygen potential gradients. Thermodynamic calculations were used to estimate the driving force for the transport of oxygen ions. The results show that the transport equation deduced from the literature describes the permeability data reasonably well and can be used to determine the diffusion coefficients and the associated activation energy of oxygen ions in the ceramic membrane material.

Comparison of domiciliary oxygen using liquid oxygen and concentrator in northern Taiwan

Directory of Open Access Journals (Sweden)

Chien-Ling Su

2014-01-01

Conclusion: Patients in the LOG used oxygen for longer hours, went on more outings, and were more likely to travel with oxygen than patients in the OCG. Being ambulatory with liquid oxygen might enable patients with COPD to walk more effectively.

Simultaneous Monitoring of Vascular Oxygenation and Tissue Oxygen Tension of Breast Tumors Under Hyperbaric Oxygen Exposure

Science.gov (United States)

2008-04-01

28. Alagoz, T., R. Buller, B. Anderson, K. Terrell , R...and oxygenation Ann . New Acad. Sci. 838 29–45 Chapman J D, Stobbe C C, Arnfield M R, Santus R, Lee J and McPhee M S 1991 Oxygen dependency of tumor

Recombination and detachment in oxygen discharges: the role of metastable oxygen molecules

International Nuclear Information System (INIS)

Gudmundsson, J T

2004-01-01

A global (volume averaged) model of oxygen discharges is used to study the transition from a recombination dominated discharge to a detachment dominated discharge. The model includes the metastable oxygen molecules O 2 (a 1 Δ g ) and O 2 (b 1 Σ g + ) and the three Herzberg states O 2 (A 3 Σ u + , A' 3 Δ u , c 1 Σ u - ). Dissociative attachment of the oxygen molecule in the ground state O 2 ( 3 Σ g - ) and the metastable oxygen molecule O 2 (a 1 Δ g ) are the dominating channels for creation of the negative oxygen ion O - . At high pressures, dissociative attachment of the Herzberg states contributes significantly to the creation of the negative oxygen ion, O - . The detachment by a collision of the metastable oxygen molecule O 2 (b 1 Σ g + ) with the oxygen ion, O - , is a significant loss process for the O - at pressures above 10 mTorr. Its contribution to the loss is more significant at a lower applied power, but at the higher pressures it is always significant. Detachment by collision with O( 3 P) is also an important loss mechanism for O - . We find that ion-ion recombination is the dominating loss process for negative ions in oxygen discharges at low pressures and calculate the critical pressure where the contributions of recombination reactions and detachment reactions are equal. This critical pressure depends on the applied power, increases with applied power and is in the range 5-14 mTorr in the pressure and power range investigated

Effect of hypolimnetic oxygenation on oxygen depletion rates in two water-supply reservoirs.

Science.gov (United States)

Gantzer, Paul A; Bryant, Lee D; Little, John C

2009-04-01

Oxygenation systems, such as bubble-plume diffusers, are used to improve water quality by replenishing dissolved oxygen (DO) in the hypolimnia of water-supply reservoirs. The diffusers induce circulation and mixing, which helps distribute DO throughout the hypolimnion. Mixing, however, has also been observed to increase hypolimnetic oxygen demand (HOD) during system operation, thus accelerating oxygen depletion. Two water-supply reservoirs (Spring Hollow Reservoir (SHR) and Carvins Cove Reservoir (CCR)) that employ linear bubble-plume diffusers were studied to quantify diffuser effects on HOD. A recently validated plume model was used to predict oxygen addition rates. The results were used together with observed oxygen accumulation rates to evaluate HOD over a wide range of applied gas flow rates. Plume-induced mixing correlated well with applied gas flow rate and was observed to increase HOD. Linear relationships between applied gas flow rate and HOD were found for both SHR and CCR. HOD was also observed to be independent of bulk hypolimnion oxygen concentration, indicating that HOD is controlled by induced mixing. Despite transient increases in HOD, oxygenation caused an overall decrease in background HOD, as well as a decrease in induced HOD during diffuser operation, over several years. This suggests that the residual or background oxygen demand decreases from one year to the next. Despite diffuser-induced increases in HOD, hypolimnetic oxygenation remains a viable method for replenishing DO in thermally-stratified water-supply reservoirs such as SHR and CCR.

Spray generator of singlet oxygen for a chemical oxygen-iodine laser

Czech Academy of Sciences Publication Activity Database

Jirásek, Vít; Hrubý, Jan; Špalek, Otomar; Čenský, Miroslav; Kodymová, Jarmila

2010-01-01

Roč. 100, č. 4 (2010), s. 779-791 ISSN 0946-2171 Grant - others:European Office of Aerospace R&D(US) FA8655-09-1-3091 Institutional research plan: CEZ:AV0Z10100523; CEZ:AV0Z20760514 Keywords : spray generator of singlet oxygen * singlet oxygen * chemical oxygen-iodine laser Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.239, year: 2010

Effects of the oxygenation level on formation of different reactive oxygen species during photodynamic therapy.

Science.gov (United States)

Price, Michael; Heilbrun, Lance; Kessel, David

2013-01-01

We examined the effect of the oxygenation level on efficacy of two photosensitizing agents, both of which target lysosomes for photodamage, but via different photochemical pathways. Upon irradiation, the chlorin termed NPe6 forms singlet oxygen in high yield while the bacteriopheophorbide WST11 forms only oxygen radicals (in an aqueous environment). Photokilling efficacy by WST11 in cell culture was impaired when the atmospheric oxygen concentration was reduced from 20% to 1%, while photokilling by NPe6 was unaffected. Studies in a cell-free system revealed that the rates of photobleaching of these agents, as a function of the oxygenation level, were correlated with results described above. Moreover, the rate of formation of oxygen radicals by either agent was more sensitive to the level of oxygenation than was singlet oxygen formation by NPe6. These data indicate that the photochemical process that leads to oxygen radical formation is more dependent on the oxygenation level than is the pathway leading to formation of singlet oxygen. © 2013 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2013 The American Society of Photobiology.

Advanced Oxygen Systems for Aircraft (Systemes d’Oxygene Avances)

Science.gov (United States)

1996-04-01

Oxygen Generating System (NAOGS), SAM-TR-80-12, Brooks AFB TX 78235, 1980. 11. Horch TC, Miller RL, Bomar JB, Tedor JB, Holden RD, Ikels KG, and...sieve oxygen generation sys- tem. Data from Horch et al (15). cabin altitude. The minimum and maximum oxygen concen- tration lines depict the...an AV-8A Aircraft; Naval Air Test Center Report No. SY-136R-81, 1981. 15. Horch TC, Miller RL, Bomar JB Jr, Tedor JB, Holden RD, Ikels KG, and

Kinetics of oxygen species in an electrically driven singlet oxygen generator

Science.gov (United States)

Azyazov, V. N.; Torbin, A. P.; Pershin, A. A.; Mikheyev, P. A.; Heaven, M. C.

2015-12-01

The kinetics of oxygen species in the gaseous medium of a discharge singlet oxygen generator has been revisited. Vibrationally excited ozone O3(υ) formed in O + O2 recombination is thought to be a significant agent in the deactivation of singlet oxygen O2(a1Δ), oxygen atom removal and ozone formation. It is shown that the process O3(υ ⩾ 2) + O2(a1Δ) → 2O2 + O is the main O2(a1Δ) deactivation channel in the post-discharge zone. If no measures are taken to decrease the oxygen atom concentration, the contribution of this process to the overall O2(a1Δ) removal is significant, even in the discharge zone. A simplified model for the kinetics of vibrationally excited ozone is proposed. Calculations based on this model yield results that are in good agreement with the experimental data.

Oxygen therapy reduces postoperative tachycardia

DEFF Research Database (Denmark)

Stausholm, K; Kehlet, H; Rosenberg, J

1995-01-01

Concomitant hypoxaemia and tachycardia in the postoperative period is unfavourable for the myocardium. Since hypoxaemia per se may be involved in the pathogenesis of postoperative tachycardia, we have studied the effect of oxygen therapy on tachycardia in 12 patients randomly allocated to blinded...... air or oxygen by facemask on the second or third day after major surgery. Inclusion criteria were arterial hypoxaemia (oxygen saturation 90 beat.min-1). Each patient responded similarly to oxygen therapy: an increase in arterial oxygen saturation and a decrease...... in heart rate (p oxygen has a positive effect on the cardiac oxygen delivery and demand balance....

Dependence of nitrite oxidation on nitrite and oxygen in low-oxygen seawater

Science.gov (United States)

Sun, Xin; Ji, Qixing; Jayakumar, Amal; Ward, Bess B.

2017-08-01

Nitrite oxidation is an essential step in transformations of fixed nitrogen. The physiology of nitrite oxidizing bacteria (NOB) implies that the rates of nitrite oxidation should be controlled by concentration of their substrate, nitrite, and the terminal electron acceptor, oxygen. The sensitivities of nitrite oxidation to oxygen and nitrite concentrations were investigated using 15N tracer incubations in the Eastern Tropical North Pacific. Nitrite stimulated nitrite oxidation under low in situ nitrite conditions, following Michaelis-Menten kinetics, indicating that nitrite was the limiting substrate. The nitrite half-saturation constant (Ks = 0.254 ± 0.161 μM) was 1-3 orders of magnitude lower than in cultivated NOB, indicating higher affinity of marine NOB for nitrite. The highest rates of nitrite oxidation were measured in the oxygen depleted zone (ODZ), and were partially inhibited by additions of oxygen. This oxygen sensitivity suggests that ODZ specialist NOB, adapted to low-oxygen conditions, are responsible for apparently anaerobic nitrite oxidation.

Hot and Dry Cleaning of Biomass-Gasified Gas Using Activated Carbons with Simultaneous Removal of Tar, Particles, and Sulfur Compounds

Directory of Open Access Journals (Sweden)

Kinya Sakanishi

2012-05-01

Full Text Available This study proposes a gas-cleaning process for the simultaneous removal of sulfur compounds, tar, and particles from biomass-gasified gas using Fe-supported activated carbon and a water-gas shift reaction. On a laboratory scale, the simultaneous removal of H2S and COS was performed under a mixture of gases (H2/CO/CO2/CH4/C2H4/N2/H2S/COS/steam. The reactions such as COS + H2 → H2S + CO and COS + H2O → H2S + CO2 and the water-gas shift reaction were promoted on the Fe-supported activated carbon. The adsorption capacity with steam was higher than that without steam. On a bench scale, the removal of impurities from a gas derived from biomass gasification was investigated using two activated filters packed with Fe-supported activated carbon. H2S and COS, three- and four-ring polycyclic aromatic hydrocarbons (PAHs, and particles were removed and a water-gas shift reaction was promoted through the first filter at 320–350 °C. The concentrations of H2S and COS decreased to less than 0.1 ppmv. Particles and the one- and two-ring PAHs, except for benzene, were then removed through the second filter at 60–170 °C. The concentration of tar and particles decreased from 2428 to 102 mg Nm−3 and from 2244 to 181 mg Nm−3, respectively.

Analysis of IGCC-based plants with carbon capture for an efficient and flexible electric power generation

International Nuclear Information System (INIS)

Sorgenfrei, Max

2016-01-01

In this work, systems based on the Integrated gasification combined cycle (IGCC) technology with carbon capture are analyzed regarding an efficient and flexible electric power generation. All analysis are related to a high-efficiency or low-cost IGCC base case with carbon capture which are both commercially available. In the high-efficiency base case, thermodynamic inefficiencies are determined based on a conventional exergy analysis. The gasifier followed by the combustion chamber of the gas turbine running on syngas are rated to the largest inefficiencies. Based on an advanced exergy analysis, the inefficiencies are split into an avoidable and unavoidable part as well as an endogenous and exogenous part. For example, it was found that about half of the inefficiencies within the gasifier are caused by other components of the overall system(exogenous part). Further investigations on the combination of both splitting types are presented. The gas turbine system is identified to be a major component and therefore a detailed model was developed using state-of-the-art technologies. Based on this model, 12 types of characteristic inefficiencies were determined and rated by their exergy destruction. Chemical-Looping Combustion (CLC) is one of the most promising technologies to enhance the available IGCC design. CLC uses composite metal particles acting as an oxygen carrier to transport oxygen from the air to the fuel gas through a redox-cycle. Thus, the inefficiencies associated with the combustion process decrease and the application of physical absorption for capturing CO 2 is replaced by an inherent CO 2 -capture. In this work, the most suitable oxygen carriers for CLC using syngas (nickel oxide and iron oxide) are analyzed at different temperatures. Moreover, different types of gasifier as well as CLC reactor designs are analyzed. Regenerating the oxygen carrier by steam and air, produces additional hydrogen from the reduction of steam which is further combusted

Hyperbaric Oxygen Therapy and Oxygen Compatibility of Skin and Wound Care Products.

Science.gov (United States)

Bernatchez, Stéphanie F; Tucker, Joseph; Chiffoleau, Gwenael

2017-11-01

Objective: Use test methods to assess the oxygen compatibility of various wound care products. Approach: There are currently no standard test methods specifically for evaluating the oxygen compatibility and safety of materials under hyperbaric oxygen (HBO) conditions. However, tests such as the oxygen index (OI), oxygen exposure (OE), and autogenous ignition temperature (AIT) can provide useful information. Results: The OI test measures the minimum oxygen concentration that will support candle-like burning, and it was used to test 44 materials. All but two exhibited an OI equal to or greater (safer) than a control material commonly used in HBO. The OE test exposes each material to an oxygen-enriched atmosphere (>99.5% oxygen) to monitor temperature and pressure for an extended duration. The results of the OE testing indicated that none of the 44 articles tested with this method self-ignited within the 60°C, 3 atm pressurized oxygen atmosphere. The AIT test exposes materials to a rapid ramp up in temperature in HBO conditions at 3 atm until ignition occurs. Ten wound care materials and seven materials usually avoided in HBO chambers were tested. The AIT ranged from 138°C to 384°C for wound care products and from 146°C to 420°C for the other materials. Innovation: This work provides useful data and recommendations to help develop a new standard approach for evaluating the HBO compatibility of wound care products to ensure safety for patients and clinicians. Conclusion: The development of an additional test to measure the risk of electrostatic discharge of materials in HBO conditions is needed.

Oxygen transfer rate during the production of alginate by Azotobacter vinelandii under oxygen-limited and non oxygen-limited conditions

Directory of Open Access Journals (Sweden)

Peña Carlos F

2011-02-01

Full Text Available Abstract Background The oxygen transfer rate (OTR and dissolved oxygen tension (DOT play an important role in determining alginate production and its composition; however, no systematic study has been reported about the independent influence of the OTR and DOT. In this paper, we report a study about alginate production and the evolution of the molecular mass of the polymer produced by a wild-type A. vinelandii strain ATCC 9046, in terms of the maximum oxygen transfer rate (OTRmax in cultures where the dissolved oxygen tension (DOT was kept constant. Results The results revealed that in the two dissolved oxygen conditions evaluated, strictly controlled by gas blending at 0.5 and 5% DOT, an increase in the agitation rate (from 300 to 700 rpm caused a significant increase in the OTRmax (from 17 to 100 mmol L-1 h-1 for DOT of 5% and from 6 to 70 mmol L-1 h-1 for DOT of 0.5%. This increase in the OTRmax improved alginate production, as well as the specific alginate production rate (SAPR, reaching a maximal alginate concentration of 3.1 g L-1 and a SAPR of 0.031 g alg g biom-1 h-1 in the cultures at OTRmax of 100 mmol L-1 h-1. In contrast, the mean molecular mass (MMM of the alginate isolated from cultures developed under non-oxygen limited conditions increased by decreasing the OTRmax, reaching a maximal of 550 kDa at an OTRmax of 17 mmol L-1 h-1 . However, in the cultures developed under oxygen limitation (0.5% DOT, the MMM of the polymer was practically the same (around 200 kDa at 300 and 700 rpm, and this remained constant throughout the cultivation. Conclusions Overall, our results showed that under oxygen-limited and non oxygen-limited conditions, alginate production and its molecular mass are linked to the OTRmax, independently of the DOT of the culture.

A theoretical model for oxygen transport in skeletal muscle under conditions of high oxygen demand.

Science.gov (United States)

McGuire, B J; Secomb, T W

2001-11-01

Oxygen transport from capillaries to exercising skeletal muscle is studied by use of a Krogh-type cylinder model. The goal is to predict oxygen consumption under conditions of high demand, on the basis of a consideration of transport processes occurring at the microvascular level. Effects of the decline in oxygen content of blood flowing along capillaries, intravascular resistance to oxygen diffusion, and myoglobin-facilitated diffusion are included. Parameter values are based on human skeletal muscle. The dependence of oxygen consumption on oxygen demand, perfusion, and capillary density are examined. When demand is moderate, the tissue is well oxygenated and consumption is slightly less than demand. When demand is high, capillary oxygen content declines rapidly with axial distance and radial oxygen transport is limited by diffusion resistance within the capillary and the tissue. Under these conditions, much of the tissue is hypoxic, consumption is substantially less than demand, and consumption is strongly dependent on capillary density. Predicted consumption rates are comparable with experimentally observed maximal rates of oxygen consumption.

Oxygen-transfer performance of a newly designed, very low-volume membrane oxygenator.

Science.gov (United States)

Burn, Felice; Ciocan, Sorin; Carmona, Natalia Mendez; Berner, Marion; Sourdon, Joevin; Carrel, Thierry P; Tevaearai Stahel, Hendrik T; Longnus, Sarah L

2015-09-01

Oxygenation of blood and other physiological solutions are routinely required in fundamental research for both in vitro and in vivo experimentation. However, very few oxygenators with suitable priming volumes (parallel-oriented microporous polypropylene hollow fibres, placed inside a hollow shell with a lateral-luer outlet, and sealed at both extremities. With this design, perfusate is delivered via the core-tube to the centre of the mini-oxygenator, and exits via the luer port. A series of mini-oxygenators were constructed and tested in an in vitro perfusion circuit by monitoring oxygen transfer using modified Krebs-Henseleit buffer or whole porcine blood. Effects of perfusion pressure and temperature over flows of 5-60 ml × min(-1) were assessed. Twelve mini-oxygenators with a mean priming volume of 1.5 ± 0.3 ml were evaluated. With buffer, oxygen transfer reached a maximum of 14.8 ± 1.0 ml O2 × l(-1) (pO2: 450 ± 32 mmHg) at perfusate flow rates of 5 ml × min(-1) and decreased with an increase in perfusate flow to 7.8 ± 0.7 ml ml O2 × l(-1) (pO2: 219 ± 24 mmHg) at 60 ml × min(-1). Similarly, with blood perfusate, oxygen transfer also decreased as perfusate flow increased, ranging from 33 ± 5 ml O2 × l(-1) at 5 ml × min(-1) to 11 ± 2 ml O2 × l(-1) at 60 ml × min(-1). Furthermore, oxygen transfer capacity remained stable with blood perfusion over a period of at least 2 h. We have developed a new miniaturized membrane oxygenator with an ultra-low priming volume (circuits, such as small animal extracorporeal circulation and ex vivo organ perfusion. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Carbon mineralization and oxygen dynamics in sediments with deep oxygen penetration, Lake Superior

DEFF Research Database (Denmark)

Li, Jiying; Crowe, Sean Andrew; Miklesh, David

2012-01-01

To understand carbon and oxygen dynamics in sediments with deep oxygen penetration, we investigated eight locations (160–318-m depth) throughout Lake Superior. Despite the 2–4 weight percent organic carbon content, oxygen penetrated into the sediment by 3.5 to > 12 cm at all locations. Such deep ...... volume-specific carbon degradation rates were 0.3–1.5 µmol cm−3 d−1; bioturbation coefficient near the sediment surface was 3–8 cm2 yr−1. These results indicate that carbon cycling in large freshwater systems conforms to many of the same trends as in marine systems.......To understand carbon and oxygen dynamics in sediments with deep oxygen penetration, we investigated eight locations (160–318-m depth) throughout Lake Superior. Despite the 2–4 weight percent organic carbon content, oxygen penetrated into the sediment by 3.5 to > 12 cm at all locations. Such deep......, suggesting that temporal variability in deeply oxygenated sediments may be greater than previously acknowledged. The oxygen uptake rates (4.4–7.7 mmol m−2 d−1, average 6.1 mmol m−2 d−1) and carbon mineralization efficiency (∼ 90% of deposited carbon) were similar to those in marine hemipelagic and pelagic...

Spatially monitoring oxygen level in 3D microfabricated cell culture systems using optical oxygen sensing beads.

Science.gov (United States)

Wang, Lin; Acosta, Miguel A; Leach, Jennie B; Carrier, Rebecca L

2013-04-21

Capability of measuring and monitoring local oxygen concentration at the single cell level (tens of microns scale) is often desirable but difficult to achieve in cell culture. In this study, biocompatible oxygen sensing beads were prepared and tested for their potential for real-time monitoring and mapping of local oxygen concentration in 3D micro-patterned cell culture systems. Each oxygen sensing bead is composed of a silica core loaded with both an oxygen sensitive Ru(Ph2phen3)Cl2 dye and oxygen insensitive Nile blue reference dye, and a poly-dimethylsiloxane (PDMS) shell rendering biocompatibility. Human intestinal epithelial Caco-2 cells were cultivated on a series of PDMS and type I collagen based substrates patterned with micro-well arrays for 3 or 7 days, and then brought into contact with oxygen sensing beads. Using an image analysis algorithm to convert florescence intensity of beads to partial oxygen pressure in the culture system, tens of microns-size oxygen sensing beads enabled the spatial measurement of local oxygen concentration in the microfabricated system. Results generally indicated lower oxygen level inside wells than on top of wells, and local oxygen level dependence on structural features of cell culture surfaces. Interestingly, chemical composition of cell culture substrates also appeared to affect oxygen level, with type-I collagen based cell culture systems having lower oxygen concentration compared to PDMS based cell culture systems. In general, results suggest that oxygen sensing beads can be utilized to achieve real-time and local monitoring of micro-environment oxygen level in 3D microfabricated cell culture systems.

Oxygen evolution reaction catalysis

Energy Technology Data Exchange (ETDEWEB)

Haber, Joel A.; Jin, Jian; Xiang, Chengxiang; Gregoire, John M.; Jones, Ryan J.; Guevarra, Dan W.; Shinde, Aniketa A.

2016-09-06

An Oxygen Evolution Reaction (OER) catalyst includes a metal oxide that includes oxygen, cerium, and one or more second metals. In some instances, the cerium is 10 to 80 molar % of the metals in the metal oxide and/or the catalyst includes two or more second metals. The OER catalyst can be included in or on an electrode. The electrode can be arranged in an oxygen evolution system such that the Oxygen Evolution Reaction occurs at the electrode.

Relating oxygen partial pressure, saturation and content: the haemoglobin-oxygen dissociation curve.

Science.gov (United States)

Collins, Julie-Ann; Rudenski, Aram; Gibson, John; Howard, Luke; O'Driscoll, Ronan

2015-09-01

The delivery of oxygen by arterial blood to the tissues of the body has a number of critical determinants including blood oxygen concentration (content), saturation (S O2 ) and partial pressure, haemoglobin concentration and cardiac output, including its distribution. The haemoglobin-oxygen dissociation curve, a graphical representation of the relationship between oxygen satur-ation and oxygen partial pressure helps us to understand some of the principles underpinning this process. Historically this curve was derived from very limited data based on blood samples from small numbers of healthy subjects which were manipulated in vitro and ultimately determined by equations such as those described by Severinghaus in 1979. In a study of 3524 clinical specimens, we found that this equation estimated the S O2 in blood from patients with normal pH and S O2 >70% with remarkable accuracy and, to our knowledge, this is the first large-scale validation of this equation using clinical samples. Oxygen saturation by pulse oximetry (S pO2 ) is nowadays the standard clinical method for assessing arterial oxygen saturation, providing a convenient, pain-free means of continuously assessing oxygenation, provided the interpreting clinician is aware of important limitations. The use of pulse oximetry reduces the need for arterial blood gas analysis (S aO2 ) as many patients who are not at risk of hypercapnic respiratory failure or metabolic acidosis and have acceptable S pO2 do not necessarily require blood gas analysis. While arterial sampling remains the gold-standard method of assessing ventilation and oxygenation, in those patients in whom blood gas analysis is indicated, arterialised capillary samples also have a valuable role in patient care. The clinical role of venous blood gases however remains less well defined.

Relating oxygen partial pressure, saturation and content: the haemoglobin–oxygen dissociation curve

Directory of Open Access Journals (Sweden)

Julie-Ann Collins

2015-09-01

The delivery of oxygen by arterial blood to the tissues of the body has a number of critical determinants including blood oxygen concentration (content, saturation (SO2 and partial pressure, haemoglobin concentration and cardiac output, including its distribution. The haemoglobin–oxygen dissociation curve, a graphical representation of the relationship between oxygen satur­ation and oxygen partial pressure helps us to understand some of the principles underpinning this process. Historically this curve was derived from very limited data based on blood samples from small numbers of healthy subjects which were manipulated in vitro and ultimately determined by equations such as those described by Severinghaus in 1979. In a study of 3524 clinical specimens, we found that this equation estimated the SO2 in blood from patients with normal pH and SO2 >70% with remarkable accuracy and, to our knowledge, this is the first large-scale validation of this equation using clinical samples. Oxygen saturation by pulse oximetry (SpO2 is nowadays the standard clinical method for assessing arterial oxygen saturation, providing a convenient, pain-free means of continuously assessing oxygenation, provided the interpreting clinician is aware of important limitations. The use of pulse oximetry reduces the need for arterial blood gas analysis (SaO2 as many patients who are not at risk of hypercapnic respiratory failure or metabolic acidosis and have acceptable SpO2 do not necessarily require blood gas analysis. While arterial sampling remains the gold-standard method of assessing ventilation and oxygenation, in those patients in whom blood gas analysis is indicated, arterialised capillary samples also have a valuable role in patient care. The clinical role of venous blood gases however remains less well defined.

Integrated turbomachine oxygen plant

Science.gov (United States)

Anand, Ashok Kumar; DePuy, Richard Anthony; Muthaiah, Veerappan

2014-06-17

An integrated turbomachine oxygen plant includes a turbomachine and an air separation unit. One or more compressor pathways flow compressed air from a compressor through one or more of a combustor and a turbine expander to cool the combustor and/or the turbine expander. An air separation unit is operably connected to the one or more compressor pathways and is configured to separate the compressed air into oxygen and oxygen-depleted air. A method of air separation in an integrated turbomachine oxygen plant includes compressing a flow of air in a compressor of a turbomachine. The compressed flow of air is flowed through one or more of a combustor and a turbine expander of the turbomachine to cool the combustor and/or the turbine expander. The compressed flow of air is directed to an air separation unit and is separated into oxygen and oxygen-depleted air.

Oxygen sensitive polymeric nanocapsules for optical dissolved oxygen sensors

Science.gov (United States)

Sun, Zhijuan; Cai, Chenxin; Guo, Fei; Ye, Changhuai; Luo, Yingwu; Ye, Shuming; Luo, Jianchao; Zhu, Fan; Jiang, Chunyue

2018-04-01

Immobilization of the oxygen-sensitive probes (OSPs) in the host matrix greatly impacts the performance and long-term usage of the optical dissolved oxygen (DO) sensors. In this work, fluorescent dyes, as the OSPs, were encapsulated with a crosslinked fluorinated polymer shell by interfacial confined reversible addition fragmentation chain transfer miniemulsion polymerization to fabricate oxygen sensitive polymeric nanocapsules (NCs). The location of fluorescent dyes and the fluorescent properties of the NCs were fully characterized by fourier transform infrared spectrometer, x-ray photoelectron spectrometer and fluorescent spectrum. Dye-encapsulated capacity can be precisely tuned from 0 to 1.3 wt% without self-quenching of the fluorescent dye. The crosslinked fluorinated polymer shell is not only extremely high gas permeability, but also prevents the fluorescent dyes from leakage in aqueous as well as in various organic solvents, such as ethanol, acetone and tetrahydrofuran (THF). An optical DO sensor based on the oxygen sensitive NCs was fabricated, showing high sensitivity, short response time, full reversibility, and long-term operational stability of online monitoring DO. The sensitivity of the optical DO sensor is 7.02 (the ratio of the response value in fully deoxygenated and saturated oxygenated water) in the range 0.96-14.16 mg l-1 and the response time is about 14.3 s. The sensor’s work curve was fit well using the modified Stern-Volmer equation by two-site model, and its response values are hardly affected by pH ranging from 2 to 12 and keep constant during continuous measurement for 3 months. It is believed that the oxygen sensitive polymeric NCs-based optical DO sensor could be particularly useful in long-term online DO monitoring in both aqueous and organic solvent systems.

Effects of motexafin gadolinium on tumor oxygenation and cellular oxygen consumption

International Nuclear Information System (INIS)

Donnelly, E.T.; Liu, Y.; Rockwell, S.; Magda, D.

2003-01-01

Full text: Recent work in our laboratory showed that motexafin gadolinium (MGd, Xcytrin), a drug currently in Phase III clinical trials as an adjuvant to radiation therapy, modulates the oxygen tensions in EMT6 tumors. The median pO 2 increased from the control value of 1.5±0.4 mmHg to 7.4 ± 3.8 mmHg six hours after treatment with 40 μmol/kg MGd and the percentage of severely hypoxic readings in the tumors ( 7 plateau phase EMT6 cells in 3 mL Dulbecco's Modified Eagle's Medium supplemented with 10% dialyzed fetal bovine serum, which contains no ascorbic acid. In the absence of ascorbic acid, 100 μM MGd did not alter the cellular oxygen consumption rate for EMT6 cells significantly. Marked inhibition of cellular oxygen consumption was observed when cells were incubated with 100 μM MGd in medium supplemented with equimolar ascorbic acid (a 31.5% decrease in consumption was observed after 6 hours of treatment). The 5% mannitol vehicle solution with equimolar ascorbic acid had no discernible effect on cellular oxygen consumption. Ascorbic acid may facilitate cellular uptake of MGd via the intermediate formation of a MGd-oxalate complex. These studies suggest that changes in cellular oxygen consumption could contribute to the changes in tumor oxygenation seen after administration of MGd. These experiments were supported by Pharmacyclics and training grant T32CA09085 from the NIH (E.T.D.). We thank Dr. Raymond Russell for allowing us to use his oxygen electrode apparatus

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.

Internal-reference solid-electrolyte oxygen sensor

International Nuclear Information System (INIS)

Haaland, D.M.

1977-01-01

A new solid-electrolyte oxygen sensor has been developed that eliminates the conventional oxygen reference in previous solid-electrolyte oxygen sensor designs and is, therefore, ideally suited as an insertion device for remote oxygen monitoring applications. It is constructed with two cells of stabilized zirconia sealed into a small unit using a new high-temperature platinum-zirconia seal. One electrochemical cell monitors the ratio of oxygen partial pressures inside and outside the sensor while the other solid-electrolyte cell is used for quantitative electrochemical pumping of oxygen. The internal oxygen reference is generated by initially pumping all oxygen out of the known internal volume of the sensor and then quantitatively pumping oxygen back in until oxygen partial pressures are equal inside and out. This information is used with the ideal gas law to calculate oxygen partial pressures. Tests were conducted from 400 to 1000 0 C in mixtures of oxygen and nitrogen spanning approximately 0.2 to 21 percent oxygen concentration range. Sensors with sputtered platinum and porous platinum paste electrodes were compared

Non-self-sustained electric discharge in oxygen gas mixtures: singlet delta oxygen production

CERN Document Server

Ionin, A A; Kotkov, A A; Kochetov, I V; Napartovich, A P; Seleznev, L V; Sinitsyn, D V; Hager, G D

2003-01-01

The possibility of obtaining a high specific input energy in an electron-beam sustained discharge ignited in oxygen gas mixtures O sub 2 : Ar : CO (or H sub 2) at the total gas pressures of 10-100 Torr was experimentally demonstrated. The specific input energy per molecular component exceeded approx 6 kJ l sup - sup 1 atm sup - sup 1 (150 kJ mol sup - sup 1) as a small amount of carbon monoxide was added into a gas mixture of oxygen and argon. It was theoretically demonstrated that one might expect to obtain a singlet delta oxygen yield of 25% exceeding its threshold value needed for an oxygen-iodine laser operation at room temperature, when maintaining a non-self-sustained discharge in oxygen gas mixtures with molecular additives CO, H sub 2 or D sub 2. The efficiency of singlet delta oxygen production can be as high as 40%.

Ambient oxygen promotes tumorigenesis.

Directory of Open Access Journals (Sweden)

Ho Joong Sung

2011-05-01

Full Text Available Oxygen serves as an essential factor for oxidative stress, and it has been shown to be a mutagen in bacteria. While it is well established that ambient oxygen can also cause genomic instability in cultured mammalian cells, its effect on de novo tumorigenesis at the organismal level is unclear. Herein, by decreasing ambient oxygen exposure, we report a ∼50% increase in the median tumor-free survival time of p53-/- mice. In the thymus, reducing oxygen exposure decreased the levels of oxidative DNA damage and RAG recombinase, both of which are known to promote lymphomagenesis in p53-/- mice. Oxygen is further shown to be associated with genomic instability in two additional cancer models involving the APC tumor suppressor gene and chemical carcinogenesis. Together, these observations represent the first report directly testing the effect of ambient oxygen on de novo tumorigenesis and provide important physiologic evidence demonstrating its critical role in increasing genomic instability in vivo.

Oxygen Tension in the Aqueous Humor of Human Eyes under Different Oxygenation Conditions

Directory of Open Access Journals (Sweden)

Farideh Sharifipour

2013-01-01

Full Text Available Purpose: To measure oxygen tension in the aqueous humor of human eyes under different oxygenation conditions. Methods: This prospective comparative interventional case series consisted of two parts. In the first part, 120 consecutive patients scheduled for cataract surgery were randomized into group I (control group in which surgery was performed under local anesthesia inhaling 21% oxygen; group II in whom general anesthesia using 50% oxygen was employed; and group III receiving general anesthesia with 100% oxygen. After aspirating 0.2 ml aqueous humor under sterile conditions, the aqueous sample and a simultaneously drawn arterial blood sample were immediately analyzed using a blood gas analyzer. In part II the same procedures were performed in 10 patients after fitting a contact lens and patching the eye for 20 minutes (group IV and in 10 patients after transcorneal delivery of oxygen at a flow rate of 5 L/min (group V. Results: Mean aqueous PO2 in groups I, II and III was 112.3±6.2, 141.1±20.4, and 170.1±27 mmHg, respectively (P values <0.001 and mean arterial PO2 was 85.7±7.9, 184.6±46, and 379.1±75.9 mmHg, respectively (P values <0.001. Aqueous PO2 was 77.2±9.2 mmHg in group IV and 152.3±10.9 mmHg in group V (P values <0.001. There was a significant correlation between aqueous and blood PO2 (r=0.537, P<0.001. The contribution of atmospheric oxygen to aqueous PO2 was 23.7%. Conclusion: Aqueous oxygen tension is mostly dependent on the systemic circulation and in part on the atmosphere. Increasing inspiratory oxygen and transcorneal oxygen delivery both increase aqueous PO2 levels.

A Low-Pressure Oxygen Storage System for Oxygen Supply in Low-Resource Settings.

Science.gov (United States)

Rassool, Roger P; Sobott, Bryn A; Peake, David J; Mutetire, Bagayana S; Moschovis, Peter P; Black, Jim Fp

2017-12-01

Widespread access to medical oxygen would reduce global pneumonia mortality. Oxygen concentrators are one proposed solution, but they have limitations, in particular vulnerability to electricity fluctuations and failure during blackouts. The low-pressure oxygen storage system addresses these limitations in low-resource settings. This study reports testing of the system in Melbourne, Australia, and nonclinical field testing in Mbarara, Uganda. The system included a power-conditioning unit, a standard oxygen concentrator, and an oxygen store. In Melbourne, pressure and flows were monitored during cycles of filling/emptying, with forced voltage fluctuations. The bladders were tested by increasing pressure until they ruptured. In Mbarara, the system was tested by accelerated cycles of filling/emptying and then run on grid power for 30 d. The low-pressure oxygen storage system performed well, including sustaining a pressure approximately twice the standard working pressure before rupture of the outer bag. Flow of 1.2 L/min was continuously maintained to a simulated patient during 30 d on grid power, despite power failures totaling 2.9% of the total time, with durations of 1-176 min (mean 36.2, median 18.5). The low-pressure oxygen storage system was robust and durable, with accelerated testing equivalent to at least 2 y of operation revealing no visible signs of imminent failure. Despite power cuts, the system continuously provided oxygen, equivalent to the treatment of one child, for 30 d under typical power conditions for sub-Saharan Africa. The low-pressure oxygen storage system is ready for clinical field trials. Copyright © 2017 by Daedalus Enterprises.

LT-CFB. Applications and follow-up. CP Kelco. Appendix 1. [Low Temperature Circulating Fluid Bed gasifier]; LT-CFB. Anvendelsesmuligheder og opfoelgning. CP Kelco. Bilag 1

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-04-15

This appendix describes how LT-CFB advantageously can gasify residual products at the company CP Kelco's factory. CP Kelco produces the gelation, thickeners and stabilizers carrageenan and pectin from seaweed and citrus peel. Residues from the production consist of a fiber-containing biological material, which has a calorific value of dry matter about 15 to 20 MJ / kg. In addition, there are waste products from the wastewater treatment plant, which are also proposed re-used in the project. The report describes the economic analyses, the overall data and system design for two scenarios, whereas the description of the plant capacities, sizes and detailed data etc. are described only for one scenario. In addition to savings in the purchase of natural gas the gas production also results in a significant reduction in CO{sub 2} emissions, the product gas being characterized as CO{sub 2} neutral. Since CP Kelco is subject to the CO{sub 2} quota system the saved amount of CO{sub 2} emissions represents a significant value. In the economic analyses, the value of 1 ton of CO{sub 2} is set at DKK 100. (LN)

Simultaneous sampling of tissue oxygenation and oxygen consumption in skeletal muscle.

Science.gov (United States)

Nugent, William H; Song, Bjorn K; Pittman, Roland N; Golub, Aleksander S

2016-05-01

Under physiologic conditions, microvascular oxygen delivery appears to be well matched to oxygen consumption in respiring tissues. We present a technique to measure interstitial oxygen tension (PISFO2) and oxygen consumption (VO2) under steady-state conditions, as well as during the transitions from rest to activity and back. Phosphorescence Quenching Microscopy (PQM) was employed with pneumatic compression cycling to achieve 1 to 10 Hz sampling rates of interstitial PO2 and simultaneous recurrent sampling of VO2 (3/min) in the exteriorized rat spinotrapezius muscle. The compression pressure was optimized to 120-130 mmHg without adverse effect on the tissue preparation. A cycle of 5s compression followed by 15s recovery yielded a resting VO2 of 0.98 ± 0.03 ml O2/100 cm(3)min while preserving microvascular oxygen delivery. The measurement system was then used to assess VO2 dependence on PISFO2 at rest and further tested under conditions of isometric muscle contraction to demonstrate a robust ability to monitor the on-kinetics of tissue respiration and the compensatory changes in PISFO2 during contraction and recovery. The temporal and spatial resolution of this approach is well suited to studies seeking to characterize microvascular oxygen supply and demand in thin tissues. Copyright © 2015 Elsevier Inc. All rights reserved.

Kinetics of oxygen species in an electrically driven singlet oxygen generator

International Nuclear Information System (INIS)

Azyazov, V.N.; Torbin, A.P.; Pershin, A.A.; Mikheyev, P.A.; Heaven, M.C.

2015-01-01

Highlights: • Vibrational excitation of O_3 increases the rate constant for O_3 + O_2(a) → 2O_2(X) + O. • Vibrationally excited O_3 is produced by the O + O_2(X) + M → O_3 + M reaction. • Ozone concentrations are impacted by the reactions of vibrationally excited O_3. • Relevant to ozone concentrations in oxygen discharges and the upper atmosphere. - Abstract: The kinetics of oxygen species in the gaseous medium of a discharge singlet oxygen generator has been revisited. Vibrationally excited ozone O_3(υ) formed in O + O_2 recombination is thought to be a significant agent in the deactivation of singlet oxygen O_2(a"1Δ), oxygen atom removal and ozone formation. It is shown that the process O_3(υ ⩾ 2) + O_2(a"1Δ) → 2O_2 + O is the main O_2(a"1Δ) deactivation channel in the post-discharge zone. If no measures are taken to decrease the oxygen atom concentration, the contribution of this process to the overall O_2(a"1Δ) removal is significant, even in the discharge zone. A simplified model for the kinetics of vibrationally excited ozone is proposed. Calculations based on this model yield results that are in good agreement with the experimental data.

Neuroprotection of hyperbaric oxygen therapy in sub-acute traumatic brain injury: not by immediately improving cerebral oxygen saturation and oxygen partial pressure.

Science.gov (United States)

Zhou, Bao-Chun; Liu, Li-Jun; Liu, Bing

2016-09-01

Although hyperbaric oxygen (HBO) therapy can promote the recovery of neural function in patients who have suffered traumatic brain injury (TBI), the underlying mechanism is unclear. We hypothesized that hyperbaric oxygen treatment plays a neuroprotective role in TBI by increasing regional transcranial oxygen saturation (rSO 2 ) and oxygen partial pressure (PaO 2 ). To test this idea, we compared two groups: a control group with 20 healthy people and a treatment group with 40 TBI patients. The 40 patients were given 100% oxygen of HBO for 90 minutes. Changes in rSO 2 were measured. The controls were also examined for rSO 2 and PaO 2 , but received no treatment. rSO 2 levels in the patients did not differ significantly after treatment, but levels before and after treatment were significantly lower than those in the control group. PaO 2 levels were significantly decreased after the 30-minute HBO treatment. Our findings suggest that there is a disorder of oxygen metabolism in patients with sub-acute TBI. HBO does not immediately affect cerebral oxygen metabolism, and the underlying mechanism still needs to be studied in depth.

OXYGEN MANAGEMENT DURING ALCOHOLIC FERMENTATION

OpenAIRE

MOENNE VARGAS, MARÍA ISABE

2013-01-01

Oxygen additions are a common practice in winemaking, as oxygen has a positive effect in fermentative kinetics, biomass synthesis and improvement of color, structure and :flavor in treated wines. However, most oxygen additions are carried out heuristically through pump-over operations solely on a know-how basis, which is difficult to manage in terms of the exact quantity of oxygen transferred to the fermenting must. It is important to estímate the amount of oxygen added because...

Medical oxygen and air travel.

Science.gov (United States)

Lyznicki, J M; Williams, M A; Deitchman, S D; Howe, J P

2000-08-01

This report responds to a resolution that asked the American Medical Association (AMA) to take action to improve airport and airline accommodations for passengers requiring medical oxygen. Information for the report was derived from a search of the MEDLINE database and references listed in pertinent articles, as well as through communications with experts in aerospace and emergency medicine. Based on this information, the AMA Council on Scientific Affairs determined that commercial air travel exposes passengers to altitude-related hypoxia and gas expansion, which may cause some passengers to experience significant symptoms and medical complications during flight. Medical guidelines are available to help physicians evaluate and counsel potential passengers who are at increased risk of inflight hypoxemia. Supplemental oxygen may be needed for some passengers to maintain adequate tissue oxygenation and prevent hypoxemic complications. For safety and security reasons, federal regulations prohibit travelers from using their own portable oxygen system onboard commercial aircraft. Many U.S. airlines supply medical oxygen for use during flight but policies and procedures vary. Oxygen-dependent passengers must make additional arrangements for the use of supplemental oxygen in airports. Uniform standards are needed to specify procedures and equipment for the use of medical oxygen in airports and aboard commercial aircraft. Revision of federal regulations should be considered to accommodate oxygen-dependent passengers and permit them to have an uninterrupted source of oxygen from departure to destination.

Oxygen transport membrane

DEFF Research Database (Denmark)

2015-01-01

The present invention relates to a novel composite oxygen transport membrane as well as its preparation and uses thereof.......The present invention relates to a novel composite oxygen transport membrane as well as its preparation and uses thereof....

TASK 2: QUENCH ZONE SIMULATION

Energy Technology Data Exchange (ETDEWEB)

Fusselman, Steve

2015-09-30

Aerojet Rocketdyne (AR) has developed an innovative gasifier concept incorporating advanced technologies in ultra-dense phase dry feed system, rapid mix injector, and advanced component cooling to significantly improve gasifier performance, life, and cost compared to commercially available state-of-the-art systems. A key feature of the AR gasifier design is the transition from the gasifier outlet into the quench zone, where the raw syngas is cooled to ~ 400°C by injection and vaporization of atomized water. Earlier pilot plant testing revealed a propensity for the original gasifier outlet design to accumulate slag in the outlet, leading to erratic syngas flow from the outlet. Subsequent design modifications successfully resolved this issue in the pilot plant gasifier. In order to gain greater insight into the physical phenomena occurring within this zone, AR developed a cold flow simulation apparatus with Coanda Research & Development with a high degree of similitude to hot fire conditions with the pilot scale gasifier design, and capable of accommodating a scaled-down quench zone for a demonstration-scale gasifier. The objective of this task was to validate similitude of the cold flow simulation model by comparison of pilot-scale outlet design performance, and to assess demonstration scale gasifier design feasibility from testing of a scaled-down outlet design. Test results did exhibit a strong correspondence with the two pilot scale outlet designs, indicating credible similitude for the cold flow simulation device. Testing of the scaled-down outlet revealed important considerations in the design and operation of the demonstration scale gasifier, in particular pertaining to the relative momentum between the downcoming raw syngas and the sprayed quench water and associated impacts on flow patterns within the quench zone. This report describes key findings from the test program, including assessment of pilot plant configuration simulations relative to actual

Integration of oxygen membranes for oxygen production in cement plants

DEFF Research Database (Denmark)

Puig Arnavat, Maria; Søgaard, Martin; Hjuler, Klaus

2015-01-01

The present paper describes the integration of oxygen membranes in cement plants both from an energy, exergy and economic point of view. Different configurations for oxygen enrichment of the tertiary air for combustion in the pre-calciner and full oxy-fuel combustion in both pre-calciner and kiln...

Relationship Between Cerebral Oxygenation and Hemodynamic and Oxygen Transport Parameters in Surgery for Acquired Heart Diseases

Directory of Open Access Journals (Sweden)

A. I. Lenkin

2012-01-01

Full Text Available Objective: to evaluate the relationship between cerebral oxygenation and hemodynamic and oxygen transport parameters in surgical correction of concomitant acquired heart diseases. Subjects and methods. Informed consent was received from 40 patients who required surgery because of concomitant (two or more acquired heart defects. During procedure, perioperative monitoring of oxygen transport and cerebral oxygenation was performed with the aid of PiCCO2 monitor (Pulsion Medical Systems, Germany and a Fore-Sight cerebral oximeter (CASMED, USA. Anesthesia was maintained with propofol and fen-tanyl, by monitoring the depth of anesthesia. Early postoperative intensive therapy was based on the protocol for early targeted correction of hemodynamic disorders. Oxygen transport and cerebral oxygenation parameters were estimated intraopera-tively and within 24 postoperative hours. A statistical analysis including evaluation of Spearman correlations was performed with the aid of SPSS 15.0. Results. During perfusion, there was a relationship between cerebral oximetry values and hemat-ocrit levels, and oxygen partial pressure in the venous blood. Furthermore, a negative correlation between cerebral oximetry values and blood lactate levels was found 30 minutes after initiation of extracorporeal circulation (EC. During the study, there was a positive correlation between cerebral oxygenation and values of cardiac index, central venous saturation, and oxygen delivery index. There was a negative relationship between cerebral oxygenation and extravascular lung water at the beginning of surgery and a correlation between cerebral oximetry values and oxygenation index by the end of the first 24 postoperative hours. Conclusion. The cerebral oxygenation values correlate -with the main determinants of oxygen transport during EC and after cardiac surgical procedures. Cerebral oximetry may be used in early targeted therapy for the surgical correction of acquired combined

Oxygenation measurements in head and neck cancers during hyperbaric oxygenation

International Nuclear Information System (INIS)

Becker, A.; Kuhnt, T.; Dunst, J.; Liedtke, H.; Krivokuca, A.; Bloching, M.

2002-01-01

Background: Tumor hypoxia has proven prognostic impact in head and neck cancers and is associated with poor response to radiotherapy. Hyperbaric oxygenation (HBO) offers an approach to overcome hypoxia. We have performed pO 2 measurements in selected patients with head and neck cancers under HBO to determine in how far changes in the oxygenation occur and whether a possible improvement of oxygenation parameters is maintained after HBO. Patients and Methods: Seven patients (five male, two female, age 51-63 years) with squamous cell cancers of the head and neck were investigated (six primaries, one local recurrence). The median pO 2 prior to HBO was determined with the Eppendorf histograph. Sites of measurement were enlarged cervical lymph nodes (n = 5), the primary tumor (n = 1) and local recurrence (n = 1). Patients then underwent HBO (100% O 2 at 240 kPa for 30 minutes) and the continuous changes in the oxygenation during HBO were determined with a Licox probe. Patients had HBO for 30 minutes (n = 6) to 40 minutes (n = 1). HBO was continued because the pO 2 had not reached a steady state after 30 minutes. After decompression, patients ventilated pure oxygen under normobaric conditions and the course of the pO 2 was further measured over about 15 minutes. Results: Prior to HBO, the median tumor pO 2 in the Eppendorf histography was 8.6 ± 5.4 mm Hg (range 3-19 mm Hg) and the pO 2 measured with the Licox probe was 17.3 ± 25.5 mm Hg (range 0-73 mm Hg). The pO 2 increased significantly during HBO to 550 ± 333 mm Hg (range 85-984 mm Hg, p = 0.018). All patients showed a marked increase irrespective of the oxygenation prior to HBO. The maximum pO 2 in the tumor was reached after 10-33 minutes (mean 17 minutes). After leaving the hyperbaric chamber, the pO 2 was 282 ± 196 mm Hg. All patients maintained an elevated pO 2 for further 5-25 minutes (138 ± 128 mm Hg, range 42-334 mm Hg, p = 0.028 vs the pO 2 prior to HBO). Conclusions: Hyperbaric oxygenation resulted in a

Transportation fuel production from gasified biomass integrated with a pulp and paper mill – Part A: Heat integration and system performance

International Nuclear Information System (INIS)

Isaksson, Johan; Jansson, Mikael; Åsblad, Anders; Berntsson, Thore

2016-01-01

Production of transportation fuels from biorefineries via biomass gasification has been suggested as a way of introducing renewable alternatives in the transportation system with an aim to reduce greenhouse gas emissions to the atmosphere. By co-locating gasification-based processes within heat demanding industries, excess heat from the gasification process can replace fossil or renewable fuels. The objective of this study was to compare the heat integration potential of four different gasification-based biorefinery concepts with a chemical pulp and paper mill. The results showed that the choice of end-product which was either methanol, Fischer-Tropsch crude, synthetic natural gas or electricity, can have significant impact on the heat integration potential with a pulp and paper mill and that the heat saving measures implemented in the mill in connection to integration of a gasification process can increase the biomass resource efficiency by up to 3%-points. Heat saving measures can reduce the necessary biomass input to the biorefinery by 50% if the sizing constraint is to replace the bark boiler with excess heat from the biorefinery. A large integrated gasification process with excess steam utilisation in a condensing turbine was beneficial only if grid electricity is produced at below 30% electrical efficiency. - Highlights: • Biomass gasification integrated with a pulp and paper mill. • Different sizing constraints of integrated biofuel production. • The biofuel product largely influence the heat integration potential. • An oversized gasifier for increased power production could be favourable.

Kinetics of oxygen species in an electrically driven singlet oxygen generator

Energy Technology Data Exchange (ETDEWEB)

Azyazov, V.N., E-mail: azyazov@fian.smr.ru [Samara State Aerospace University, 443086 (Russian Federation); Lebedev Physical Institute of RAS, Samara 443011 (Russian Federation); Torbin, A.P.; Pershin, A.A. [Samara State Aerospace University, 443086 (Russian Federation); Lebedev Physical Institute of RAS, Samara 443011 (Russian Federation); Mikheyev, P.A., E-mail: mikheyev@fian.smr.ru [Samara State Aerospace University, 443086 (Russian Federation); Lebedev Physical Institute of RAS, Samara 443011 (Russian Federation); Heaven, M.C., E-mail: mheaven@emory.edu [Emory University, Atlanta, GA 30322 (United States)

2015-12-16

Highlights: • Vibrational excitation of O{sub 3} increases the rate constant for O{sub 3} + O{sub 2}(a) → 2O{sub 2}(X) + O. • Vibrationally excited O{sub 3} is produced by the O + O{sub 2}(X) + M → O{sub 3} + M reaction. • Ozone concentrations are impacted by the reactions of vibrationally excited O{sub 3}. • Relevant to ozone concentrations in oxygen discharges and the upper atmosphere. - Abstract: The kinetics of oxygen species in the gaseous medium of a discharge singlet oxygen generator has been revisited. Vibrationally excited ozone O{sub 3}(υ) formed in O + O{sub 2} recombination is thought to be a significant agent in the deactivation of singlet oxygen O{sub 2}(a{sup 1}Δ), oxygen atom removal and ozone formation. It is shown that the process O{sub 3}(υ ⩾ 2) + O{sub 2}(a{sup 1}Δ) → 2O{sub 2} + O is the main O{sub 2}(a{sup 1}Δ) deactivation channel in the post-discharge zone. If no measures are taken to decrease the oxygen atom concentration, the contribution of this process to the overall O{sub 2}(a{sup 1}Δ) removal is significant, even in the discharge zone. A simplified model for the kinetics of vibrationally excited ozone is proposed. Calculations based on this model yield results that are in good agreement with the experimental data.

A theoretical model for the effects of reduced hemoglobin-oxygen affinity on tumor oxygenation

International Nuclear Information System (INIS)

Kavanagh, Brian D.; Secomb, Timothy W.; Hsu, Richard; Lin, P.-S.; Venitz, Jurgen; Dewhirst, Mark W.

2002-01-01

Purpose: To develop a theoretical model for oxygen delivery to tumors, and to use the model to simulate the effects of changing the affinity of hemoglobin for oxygen on tumor oxygenation. Methods and Materials: Hemoglobin affinity is expressed in terms of P 50 , the partial pressure of oxygen (Po 2 ) at half saturation. Effects of changing P 50 on arterial Po 2 are predicted using an effective vessel approach to describe diffusive oxygen transport in the lungs, assuming fixed systemic oxygen demand and fixed blood flow rate. The decline in oxygen content of blood as it flows through normal tissue before entering the tumor region is assumed fixed. The hypoxic fraction of the tumor region is predicted using a three-dimensional simulation of diffusion from a network of vessels whose geometry is derived from observations of tumor microvasculature in the rat. Results: In air-breathing rats, predicted hypoxic fraction decreases with moderate increases in P 50 , but increases with further increases of P 50 , in agreement with previous experimental results. In rats breathing hyperoxic gases, and in humans breathing either normoxic or hyperoxic gases, increased P 50 is predicted to improve tumor oxygenation. Conclusions: The results support the administration of synthetic agents to increase P 50 during radiation treatment of tumors

Wabash River Coal Gasification Repowering Project: A DOE Assessment; FINAL

International Nuclear Information System (INIS)

National Energy Technology Laboratory

2002-01-01

The goal of the U.S. Department of Energy (DOE) Clean Coal Technology Program (CCT) is to furnish the energy marketplace with a number of advanced, more efficient, and environmentally responsible coal utilization technologies through demonstration projects. These projects seek to establish the commercial feasibility of the most promising advanced coal technologies that have developed beyond the proof-of-concept stage. This document serves as a DOE post-project assessment (PPA) of a project selected in CCT Round IV, the Wabash River Coal Gasification Repowering (WRCGR) Project, as described in a Report to Congress (U.S. Department of Energy 1992). Repowering consists of replacing an existing coal-fired boiler with one or more clean coal technologies to achieve significantly improved environmental performance. The desire to demonstrate utility repowering with a two-stage, pressurized, oxygen-blown, entrained-flow, integrated gasification combined-cycle (IGCC) system prompted Destec Energy, Inc., and PSI Energy, Inc., to form a joint venture and submit a proposal for this project. In July 1992, the Wabash River Coal Gasification Repowering Project Joint Venture (WRCGRPJV, the Participant) entered into a cooperative agreement with DOE to conduct this project. The project was sited at PSI Energy's Wabash River Generating Station, located in West Terre Haute, Indiana. The purpose of this CCT project was to demonstrate IGCC repowering using a Destec gasifier and to assess long-term reliability, availability, and maintainability of the system at a fully commercial scale. DOE provided 50 percent of the total project funding (for capital and operating costs during the demonstration period) of$438 million. Construction for the demonstration project was started in July 1993. Pre-operational tests were initiated in August 1995, and construction was completed in November 1995. Commercial operation began in November 1995, and the demonstration period was completed in December

Optic nerve oxygenation

DEFF Research Database (Denmark)

Stefánsson, Einar; Pedersen, Daniella Bach; Jensen, Peter Koch

2005-01-01

The oxygen tension of the optic nerve is regulated by the intraocular pressure and systemic blood pressure, the resistance in the blood vessels and oxygen consumption of the tissue. The oxygen tension is autoregulated and moderate changes in intraocular pressure or blood pressure do not affect...... the optic nerve oxygen tension. If the intraocular pressure is increased above 40 mmHg or the ocular perfusion pressure decreased below 50 mmHg the autoregulation is overwhelmed and the optic nerve becomes hypoxic. A disturbance in oxidative metabolism in the cytochromes of the optic nerve can be seen...... at similar levels of perfusion pressure. The levels of perfusion pressure that lead to optic nerve hypoxia in the laboratory correspond remarkably well to the levels that increase the risk of glaucomatous optic nerve atrophy in human glaucoma patients. The risk for progressive optic nerve atrophy in human...

Corrosion and flow resistance of metal filter elements used in the cleanup of syngas from the Transport Gasifier at the Power Systems Development Facility

Energy Technology Data Exchange (ETDEWEB)

Robert S. Dahlin; E. Carl Landham; Xiaofeng Guan [Southern Research Institute, Wilsonville, AL (United States). Power Systems Development Facility

2008-07-01

At the Power Systems Development Facility (PSDF), a variety of filter elements and failsafes are being tested for the cleanup of coal-generated syngas from the Kellogg Brown and Root (KBR) Transport Gasifier. Thus far, no evidence of corrosion or plugging has been found in the HR-160 failsafes or sinterned metal fiber elements. However, a progressive corrosion and increase in pressure drop has been noted in the iron aluminide elements. The corrosion was first detected as reddish-brown spots of iron oxide after about 2,000 to 3,000 hours of syngas exposure. As the corrosion progressed, the spots of iron oxide merged to form a continuous scale after about 5,000 to 5,500 hours of exposure. With additional exposure, a black scale containing iron sulfide also appeared, and localized areas of sulfidation and plugging were noted in element cross sections. These effects have not resulted in any significant reduction in tensile strength, but a gradual increase in the clean element pressure drop has been noted. Flow test results suggest that there is an interaction between the corroded filter surface and the dustcake that effectively increases the residual cake flow resistance and baseline pressure drop. 10 refs., 14 figs., 1 tab.

Quantifying wind blown landscapes using time-series airborne LiDAR at White Sands Dune Field, New Mexico

Science.gov (United States)

Ewing, R. C.

2011-12-01

Wind blown landscapes are a default geomorphic and sedimentary environment in our solar system. Wind sand dunes are ubiquitous features on the surfaces of Earth, Mars and Titan and prevalent within the aeolian rock records of Earth and Mars. Dunes are sensitive to environmental and climatic changes and a complete understanding of this system promises a unique, robust and quantitative record of paleoclimate extending to the early histories of these worlds. However, our understanding of how aeolian dune landscapes evolve and how the details of the wind are recorded in cross-strata is limited by our lack of understanding of three-dimensional dune morphodynamics related to changing boundary conditions such as wind direction and magnitude and sediment source area. We use airborne LiDAR datasets over 40 km2 of White Sands Dune Field collected from June 2007, June 2008, January 2009, September 2009 and June 2010 to quantify 1) three-dimensional dune geometries, 2) annual and seasonal patterns of erosion and deposition across dune topography, 3) spatial changes in sediment flux related to position within the field, 4) spatial changes in sediment flux across sinuous crestlines and 5) morphologic changes through dune-dune interactions. In addition to measurements, we use the LiDAR data along with wind data from two near-by weather stations to develop a simple model that predicts depositional and stratigraphic patterns on dune lee slopes. Several challenges emerged using time series LiDAR data sets at White Sands Dune Field. The topography upon which the dunes sit is variable and rises by 16 meters over the length of the dune field. In order to compare individual dune geometries across the field and between data sets a base surface was interpolated from local minima and subtracted from the dune topography. Co-registration and error calculation between datasets was done manually using permanent vegetated features within the active dune field and structures built by the

Oxygen and animal evolution: Did a rise of atmospheric oxygen trigger the origin of animals?

DEFF Research Database (Denmark)

Mills, Daniel Brady; Canfield, Donald Eugene

2014-01-01

Recent studies challenge the classical view that the origin of animal life was primarily controlled by atmospheric oxygen levels. For example, some modern sponges, representing early-branching animals, can live under 200 times less oxygen than currently present in the atmosphere - levels commonly...... thought to have been maintained prior to their origination. Furthermore, it is increasingly argued that the earliest animals, which likely lived in low oxygen environments, played an active role in constructing the well-oxygenated conditions typical of the modern oceans. Therefore, while oxygen is still...

Kinetics of oxygen uncoupling of a copper based oxygen carrier

International Nuclear Information System (INIS)

Hu, Wenting; Donat, Felix; Scott, S.A.; Dennis, J.S.

2016-01-01

Highlights: • The kinetics of a Cu-based oxygen carrier was determined using a TGA. • A diffusion model was applied to remove mass transfer effects from rate parameters. • Thermodynamics are separated from kinetics, usually difficult for the CLOU reaction. • The rate parameters correctly described the behaviour in a fluidised bed. • The rate parameters can be used to predict performance of large CLOU systems. - Abstract: Here, an oxygen carrier consisting of 60 wt% CuO supported on a mixture of Al_2O_3 and CaO (23 wt% and 17 wt% respectively) was synthesised by wet-mixing powdered CuO, Al(OH)_3 and Ca(OH)_2, followed by calcination at 1000 °C. Its suitability for chemical looping with oxygen uncoupling (CLOU) was investigated. After 25 repeated redox cycles in either a thermogravimetric analyser (TGA) or a laboratory-scale fluidised bed, (with 5 vol% H_2 in N_2 as the fuel, and air as the oxidant) no significant change in either the oxygen uncoupling capacity or the overall oxygen availability of the carrier was found. In the TGA, it was found that the rate of oxygen release from the material was controlled by intrinsic chemical kinetics and external transfer of mass from the surface of the particles to the bulk gas. By modelling the various resistances, values of the rate constant for the decomposition were obtained. The activation energy of the reaction was found to be 59.7 kJ/mol (with a standard error of 5.6 kJ/mol) and the corresponding pre-exponential factor was 632 m"3/mol/s. The local rate of conversion within a particle was assumed to occur either (i) by homogeneous chemical reaction, or (ii) in uniform, non-porous grains, each reacting as a kinetically-controlled shrinking core. Upon cross validation against a batch fluidised bed experiment, the homogeneous reaction model was found to be more plausible. By accurately accounting for the various artefacts (e.g. mass transfer resistances) present in both TGA and fluidised bed experiments, it was

Heme biomolecule as redox mediator and oxygen shuttle for efficient charging of lithium-oxygen batteries

Science.gov (United States)

Ryu, Won-Hee; Gittleson, Forrest S.; Thomsen, Julianne M.; Li, Jinyang; Schwab, Mark J.; Brudvig, Gary W.; Taylor, André D.

2016-01-01

One of the greatest challenges with lithium-oxygen batteries involves identifying catalysts that facilitate the growth and evolution of cathode species on an oxygen electrode. Heterogeneous solid catalysts cannot adequately address the problematic overpotentials when the surfaces become passivated. However, there exists a class of biomolecules which have been designed by nature to guide complex solution-based oxygen chemistries. Here, we show that the heme molecule, a common porphyrin cofactor in blood, can function as a soluble redox catalyst and oxygen shuttle for efficient oxygen evolution in non-aqueous Li-O2 batteries. The heme's oxygen binding capability facilitates battery recharge by accepting and releasing dissociated oxygen species while benefiting charge transfer with the cathode. We reveal the chemical change of heme redox molecules where synergy exists with the electrolyte species. This study brings focus to the rational design of solution-based catalysts and suggests a sustainable cross-link between biomolecules and advanced energy storage. PMID:27759005

Optimal Tuning of Decentralized PI Controller of Nonlinear Multivariable Process Using Archival Based Multiobjective Particle Swarm Optimization

Directory of Open Access Journals (Sweden)

R. Kotteeswaran

2014-01-01

Full Text Available A Multiobjective Particle Swarm Optimization (MOPSO algorithm is proposed to fine-tune the baseline PI controller parameters of Alstom gasifier. The existing baseline PI controller is not able to meet the performance requirements of Alstom gasifier for sinusoidal pressure disturbance at 0% load. This is considered the major drawback of controller design. A best optimal solution for Alstom gasifier is obtained from a set of nondominated solutions using MOPSO algorithm. Performance of gasifier is investigated at all load conditions. The controller with optimized controller parameters meets all the performance requirements at 0%, 50%, and 100% load conditions. The investigations are also extended for variations in coal quality, which shows an improved stability of the gasifier over a wide range of coal quality variations.

Nitric Oxide is Required for Homeostasis of Oxygen and Reactive Oxygen Species in Barley Roots under Aerobic Conditions

DEFF Research Database (Denmark)

Gupta, Kapuganti J; Hebelstrup, Kim; Kruger, Nicholas J

2014-01-01

Oxygen, the terminal electron acceptor for mitochondrial electron transport, is vital for plants because of its role in the production of ATP by oxidative phosphorylation. While photosynthetic oxygen production contributes to the oxygen supply in leaves, reducing the risk of oxygen limitation of ...... electron transport chain (Gupta et al., 2011). Thus, NO could influence oxygen consumption under normal aerobic conditions in roots, and it is this specific function that is assessed here.......Oxygen, the terminal electron acceptor for mitochondrial electron transport, is vital for plants because of its role in the production of ATP by oxidative phosphorylation. While photosynthetic oxygen production contributes to the oxygen supply in leaves, reducing the risk of oxygen limitation...

Design and evaluation of an IGCC power plant using iron-based syngas chemical-looping (SCL) combustion

International Nuclear Information System (INIS)

Sorgenfrei, Max; Tsatsaronis, George

2014-01-01

Highlights: • A new concept for power generation including carbon capture was found. • The air reactor temperature significantly influences the net efficiency. • The use of a CO 2 turbine decreases the net efficiency. • Compared to a conventional IGCC with 90% CO 2 capture the net efficiency increases. - Abstract: Chemical-looping combustion (CLC) is a novel and promising combustion technology with inherent separation of the greenhouse gas CO 2 . This paper focuses on the design and thermodynamic evaluation of an integrated gasification combined-cycle (IGCC) process using syngas chemical looping (SCL) combustion for generating electricity. The syngas is provided by coal gasification; the gas from the gasifier is cleaned using high-temperature gas desulfurization (HGD). In this study, the oxygen carrier iron oxide (Fe 2 O 3 ) is selected to oxidize the syngas in a multistage moving-bed reactor. The resulting reduced iron particles then consist of FeO and Fe 3 O 4 . To create a closed-cycle operation, these particles are partially re-oxidized with steam in a fluidized-bed regenerator to pure Fe 3 O 4 and then fully re-oxidized in a fluidized-bed air combustor to Fe 2 O 3 . One advantage of this process is the co-production of hydrogen diluted with water vapor within the steam regenerator. Both the HGD and CLC systems are not under commercial operation so far. This mixture is fed to a gas turbine for the purpose of generating electricity. The gas turbine is expected to exhibit low NO x emissions due to the high ratio of water in the combustion chamber. Cooling the flue gas in the HRSG condenses the water vapor to yield high-purity CO 2 for subsequent compression and disposal. To evaluate the net efficiency, two conventional syngas gasifiers are considered, namely the BGL slagging gasifier and the Shell entrained-flow gasifier. The option of using a CO 2 turbine after the SCL-fuel reactor is also investigated. A sensitivity analysis is performed on the SCL

High Selectivity Oxygen Delignification

Energy Technology Data Exchange (ETDEWEB)

Lucian A. Lucia

2005-11-15

Project Objective: The objectives of this project are as follows: (1) Examine the physical and chemical characteristics of a partner mill pre- and post-oxygen delignified pulp and compare them to lab generated oxygen delignified pulps; (2) Apply the chemical selectivity enhancement system to the partner pre-oxygen delignified pulps under mill conditions (with and without any predetermined amounts of carryover) to determine how efficiently viscosity is preserved, how well selectivity is enhanced, if strength is improved, measure any yield differences and/or bleachability differences; and (3) Initiate a mill scale oxygen delignification run using the selectivity enhancement agent, collect the mill data, analyze it, and propose any future plans for implementation.

Investigation of the singlet delta oxygen and ozone yields from the pulsed radiolysis of oxygen and oxygen-noble gas mixtures

International Nuclear Information System (INIS)

Zediker, M.S.

1984-01-01

The experiments discussed herein were performed with a flowing gas apparatus coupled to the University of Illinois TRIGA reactor. The detectors (lambda = 1.27 μ 634 nm) were calibrated with a novel NO 2 titration scheme and the absorbed dose was estimated from the ozone concentrations measured in pure oxygen. The results of these experiments revealed an O 2 (a 1 Δ) production efficiency of 0.14% for direct nuclear pumping in an argon-oxygen mixture. Extensive modeling of the oxygen and argon-oxygen mixtures were benchmarked against these and other experiments. However, good agreement over a broad absorbed dose range was only possible if the O 4 + + O 4 - neutralization reaction was assumed to be nondissociative. In a second set of experiments with a nuclear sustained electrical discharge (low E/N), the O 2 (a 1 Δ) production efficiency was approx.0.40% for the electrical power densities examined. In addition, the O 2 (a 1 Δ) was observed to scale with the square root of the electrical power deposition but was independent of the oxygen concentration. A simple analytic model was developed which explains this behavior as a characteristic of an externally sustained discharge involving an electron attaching gas such as oxygen. The results of these experiments and the modeling of the chemical kinetics are discussed with an emphasis on optimizing the O 2 (a 1 Δ) and O 3 yields

Improved arterial blood oxygenation following intravenous infusion of cold supersaturated dissolved oxygen solution.

Science.gov (United States)

Grady, Daniel J; Gentile, Michael A; Riggs, John H; Cheifetz, Ira M

2014-01-01

One of the primary goals of critical care medicine is to support adequate gas exchange without iatrogenic sequelae. An emerging method of delivering supplemental oxygen is intravenously rather than via the traditional inhalation route. The objective of this study was to evaluate the gas-exchange effects of infusing cold intravenous (IV) fluids containing very high partial pressures of dissolved oxygen (>760 mm Hg) in a porcine model. Juvenile swines were anesthetized and mechanically ventilated. Each animal received an infusion of cold (13 °C) Ringer's lactate solution (30 mL/kg/hour), which had been supersaturated with dissolved oxygen gas (39.7 mg/L dissolved oxygen, 992 mm Hg, 30.5 mL/L). Arterial blood gases and physiologic measurements were repeated at 15-minute intervals during a 60-minute IV infusion of the supersaturated dissolved oxygen solution. Each animal served as its own control. Five swines (12.9 ± 0.9 kg) were studied. Following the 60-minute infusion, there were significant increases in PaO2 and SaO2 (P < 0.05) and a significant decrease in PaCO2 (P < 0.05), with a corresponding normalization in arterial blood pH. Additionally, there was a significant decrease in core body temperature (P < 0.05) when compared to the baseline preinfusion state. A cold, supersaturated dissolved oxygen solution may be intravenously administered to improve arterial blood oxygenation and ventilation parameters and induce a mild therapeutic hypothermia in a porcine model.

A review of the primary measures for tar elimination in biomass gasification processes

International Nuclear Information System (INIS)

Devi, Lopamudra; Ptasinski, K.J.; Janssen, F.J.J.G.

2003-01-01

Tar formation is one of the major problems to deal with during biomass gasification. Tar condenses at reduced temperature, thus blocking and fouling process equipments such as engines and turbines. Considerable efforts have been directed on tar removal from fuel gas. Tar removal technologies can broadly be divided into two approaches; hot gas cleaning after the gasifier (secondary methods), and treatments inside the gasifier (primary methods). Although secondary methods are proven to be effective, treatments inside the gasifier are gaining much attention as these may eliminate the need for downstream cleanup. In primary treatment, the gasifier is optimized to produce a fuel gas with minimum tar concentration. The different approaches of primary treatment are (a) proper selection of operating parameters, (b) use of bed additive/catalyst, and (c) gasifier modifications. The operating parameters such as temperature, gasifying agent, equivalence ratio, residence time, etc. play an important role in formation and decomposition of tar. There is a potential of using some active bed additives such as dolomite, olivine, char, etc. inside the gasifier. Ni-based catalyst are reported to be very effective not only for tar reduction, but also for decreasing the amount of nitrogenous compounds such as ammonia. Also, reactor modification can improve the quality of the product gas. The concepts of two-stage gasification and secondary air injection in the gasifier are of prime importance. Some aspects of primary methods and the research and development in this area are reviewed and cited in the present paper

In vivo integrated photoacoustic and confocal microscopy of hemoglobin oxygen saturation and oxygen partial pressure.

Science.gov (United States)

Wang, Yu; Hu, Song; Maslov, Konstantin; Zhang, Yu; Xia, Younan; Wang, Lihong V

2011-04-01

We developed dual-modality microscope integrating photoacoustic microscopy (PAM) and fluorescence confocal microscopy (FCM) to noninvasively image hemoglobin oxygen saturation (sO₂) and oxygen partial pressure (pO₂) in vivo in single blood vessels with high spatial resolution. While PAM measures sO₂ by imaging hemoglobin optical absorption at two wavelengths, FCM quantifies pO₂ using phosphorescence quenching. The variations of sO₂ and pO₂ values in multiple orders of vessel branches under hyperoxic (100% oxygen) and normoxic (21% oxygen) conditions correlate well with the oxygen-hemoglobin dissociation curve. In addition, the total concentration of hemoglobin is imaged by PAM at an isosbestic wavelength.

Microsensor and transcriptomic signatures of oxygen depletion in biofilms associated with chronic wounds: Biofilms and oxygen

Energy Technology Data Exchange (ETDEWEB)

James, Garth A. [Center for Biofilm Engineering, Montana State University, Bozeman Montana; Ge Zhao, Alice [Division of Dermatology, Department of Medicine, University of Washington, Seattle Washington; Usui, Marcia [Division of Dermatology, Department of Medicine, University of Washington, Seattle Washington; Underwood, Robert A. [Division of Dermatology, Department of Medicine, University of Washington, Seattle Washington; Nguyen, Hung [The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman Washington; Beyenal, Haluk [The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman Washington; deLancey Pulcini, Elinor [Center for Biofilm Engineering, Montana State University, Bozeman Montana; Agostinho Hunt, Alessandra [Department of Microbiology and Molecular Genetics, 5180 Biomedical and Physical Sciences, Michigan State University, East Lansing Michigan; Bernstein, Hans C. [Pacific Northwest National Laboratory, Chemical and Biological Signature Science, Richland Washington; Fleckman, Philip [Division of Dermatology, Department of Medicine, University of Washington, Seattle Washington; Olerud, John [Division of Dermatology, Department of Medicine, University of Washington, Seattle Washington; Williamson, Kerry S. [Center for Biofilm Engineering, Montana State University, Bozeman Montana; Franklin, Michael J. [Center for Biofilm Engineering, Montana State University, Bozeman Montana; Stewart, Philip S. [Center for Biofilm Engineering, Montana State University, Bozeman Montana

2016-02-16

Polymicrobial biofilms have been implicated in delayed wound healing, although the mechanisms by which biofilms impair wound healing are poorly understood. Many species of bacteria produce exotoxins and exoenzymes that may inhibit healing. In addition, oxygen consumption by biofilms may impede wound healing. In this study, we used oxygen microsensors to measure oxygen transects through in vitro-cultured biofilms, biofilms formed in vivo in a diabetic (db/db) mouse model, and ex vivo human chronic wound specimens. The results show that oxygen levels within both euthanized and live mouse wounds had steep gradients that reached minima ranging from 19 to 61% oxygen partial pressure, compared to atmospheric oxygen levels. The oxygen gradients in the mouse wounds were similar to those observed for clinical isolates cultured in vitro and for human ex vivo scabs. No oxygen gradients were observed for heat-killed scabs, suggesting that active metabolism by the viable bacteria contributed to the reduced oxygen partial pressure of the wounds. To characterize the metabolic activities of the bacteria in the mouse wounds, we performed transcriptomics analyses of Pseudomonas aeruginosa biofilms associated with the db/db mice wounds using Affymetrix microarrays. The results demonstrated that the bacteria expressed genes for metabolic activities associated with cell growth. Interestingly, the transcriptome results indicated that the bacteria within the wounds also experienced oxygen-limitation stress. Among the bacterial genes that were expressed in vivo were genes associated with the Anr-mediated hypoxia-stress response. Other bacterial stress response genes highly expressed in vivo were genes associated with stationary-phase growth, osmotic stress, and RpoH-mediated heat shock stress. Overall, the results support the hypothesis that the metabolic activities of bacteria in biofilms act as oxygen sinks in chronic wounds and that the depletion of oxygen contributes to the

Effects of the Oxygenation level on Formation of Different Reactive Oxygen Species During Photodynamic Therapy

OpenAIRE

Price, Michael; Heilbrun, Lance; Kessel, David

2013-01-01

We examined the effect of the oxygenation level on efficacy of two photosensitizing agents, both of which target lysosomes for photodamage but via different photochemical pathways. Upon irradiation, the chlorin termed NPe6 forms singlet oxygen in high yield while the bacteriopheophorbide WST11 forms only oxygen radicals (in an aqueous environment). Photokilling efficacy by WST11 in cell culture was impaired when the atmospheric oxygen concentration was reduced from 20% to 1%, while photokilli...

Determining the Source of Water Vapor in a Cerium Oxide Electrochemical Oxygen Separator to Achieve Aviator Grade Oxygen

Science.gov (United States)

Graf, John; Taylor, Dale; Martinez, James

2014-01-01

More than a metric ton of water is transported to the International Space Station (ISS) each year to provide breathing oxygen for the astronauts. Water is a safe and compact form of stored oxygen. The water is electrolyzed on ISS and ambient pressure oxygen is delivered to the cabin. A much smaller amount of oxygen is used each year in spacesuits to conduct Extra Vehicular Activities (EVAs). Space suits need high pressure (>1000 psia) high purity oxygen (must meet Aviator Breathing Oxygen "ABO" specifications, >99.5% O2). The water / water electrolysis system cannot directly provide high pressure, high purity oxygen, so oxygen for EVAs is transported to ISS in high pressure gas tanks. The tanks are relatively large and heavy, and the majority of the system launch weight is for the tanks and not the oxygen. Extracting high purity oxygen from cabin air and mechanically compressing the oxygen might enable on-board production of EVA grade oxygen using the existing water / water electrolysis system. This capability might also benefit human spaceflight missions, where oxygen for EVAs could be stored in the form of water, and converted into high pressure oxygen on-demand. Cerium oxide solid electrolyte-based ion transport membranes have been shown to separate oxygen from air, and a supported monolithic wafer form of the CeO2 electrolyte membrane has been shown to deliver oxygen at pressures greater than 300 psia. These supported monolithic wafers can withstand high pressure differentials even though the membrane is very thin, because the ion transport membrane is supported on both sides (Fig 1). The monolithic supported wafers have six distinct layers, each with matched coefficients of thermal expansion. The wafers are assembled into a cell stack which allows easy air flow across the wafers, uniform current distribution, and uniform current density (Fig 2). The oxygen separation is reported to be "infinitely selective" to oxygen [1] with reported purity of 99.99% [2

Spatially monitoring oxygen level in 3D microfabricated cell culture systems using optical oxygen sensing beads

OpenAIRE

Wang, Lin; Acosta, Miguel A.; Leach, Jennie B.; Carrier, Rebecca L.

2013-01-01

Capability of measuring and monitoring local oxygen concentration at the single cell level (tens of microns scale) is often desirable but difficult to achieve in cell culture. In this study, biocompatible oxygen sensing beads were prepared and tested for their potential for real-time monitoring and mapping of local oxygen concentration in 3D micro-patterned cell culture systems. Each oxygen sensing bead is composed of a silica core loaded with both an oxygen sensitive Ru(Ph2phen3)Cl2 dye and ...

Femoral venous oxygen saturation is no surrogate for central venous oxygen saturation

NARCIS (Netherlands)

van Beest, Paul A.; van der Schors, Alice; Liefers, Henriëtte; Coenen, Ludo G. J.; Braam, Richard L.; Habib, Najib; Braber, Annemarije; Scheeren, Thomas W. L.; Kuiper, Michaël A.; Spronk, Peter E.

2012-01-01

Objective: The purpose of our study was to determine if central venous oxygen saturation and femoral venous oxygen saturation can be used interchangeably during surgery and in critically ill patients. Design: Prospective observational controlled study. Setting: Nonacademic university-affiliated

Oxygen Deficit: The Bio-energetic Pathophysiology

Directory of Open Access Journals (Sweden)

ABHAY KUMAR PANDEY

2014-09-01

Full Text Available Scarcity of oxygen in humans arises via three modes. The environment may have low oxygen to breath. There can be disease in respiratory system causing hindrance to uptake of oxygen from environment and the circulatory system may be sluggish to supply to body parts that starve for oxygen. Thirdly the chemico-cellular components of blood which carry oxygen may be lowered or defective. In reference to body cells several limiting sites and mechanisms affect the amount of oxygen delivered to them, and these are under regulatory control of several functional and metabolic systems.