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04627 Carbon research in the Czech Republic
04
04 97104623
BY-PRODUCTS TO FUELS Algicidal
and fungicidal
concrete
treatment
on fabrication
of
Yasuda. E. er al. Carbon Carbonaceous Compos. Mater.: Stnrct:Prop. Relat., /Conf.j. 1995, (Pub. 1996), 409-417. Edited by Palmer, K. R. et al., World Scientific. Singapore. The effect of iodine treatment on fabrication of pitch based carbon fibrei carbon matrix composites was investigated. Coal tar pitch having the softening point of 101°C was used as a matrix precursor in this research. The specimen, 20 mm.’ in size and Vr = 43%. was put into a test tube with iodine powder. After sealing the tube, the specimen was heated at 90’C for iodine treatment. The iodine-treated specimens were heated at a rate of 2.5”Cimin up to 800°C in Ar flow for carbonization. Carbon yield of the specimen increased from 73 to 93% after 20 h of iodine treatment. For the 20 h-treated specimen, the matrix pitch did not flow out from the fibre bundle after carbonization. As the iodine treatment period increased, optical microstructure of the matrix in the carbonized specimens changed from a flow type texture to a mosaic one. 97104625
calcium
Binder compositions containing chloride, and lime component
fly ash, gypsum,
Russ. RU 2,077,516 (Cl. C04B7/28), Elesin, S. M. et al. Appl. 94,032,X07, 8 Sep 1994. (In Russian)
97104626
Some carbon-related
activities
20 Apr
related to fuels
97104631 Characteristics of chars produced from devolatilization of Yallourn brown coal at elevated pressure Yeasmin, H. et al. DGMK Tagungsber., 1997, 9703, (Proceedings ICCS ‘97.
RELATED
Maruyama, T. er al. Jpn. Kokai Tokkyo Koho JP 09 02,859 (97 02.8591 (Cl. CO4B28102). 7 Jan 1997, Appl. 95/155,001. 21 Jun 1995, 6 pp. (In Japanese) In the preparation of the concrete, the following are mixed: (A) concrete raw materials containing cement and aggregates, (B) algicides and fungicides, and, for example, selective organic herbicides and/or bactericidal inorganic metal ions, preferably Ag ions, and (C) SiOz fume, fly ash and/or powered blast furnace slags. The herbicides are added to readymixed concrete prepared from A and C and water in an amount of 0.3-6 kg/ m’, and the concrete is used in building.
Application of iodine 97104624 pitch based C/C composites
By-products
Volume 2), 689-692. Yallourn brown coal was devolatized under rapid heating conditions in pressurized drop-tube furnace using a sample of size fraction 37-53 rrm. Tests were carried out under a Nz atmosphere at pressures of 100 and 500 kPa, temperatures of 873, 1073, and 1273 K, and at residence times ranging from 0.2 to 2 s. For each run, weight loss was determined. Char structural parameters, such as CO2 surface area, true densities, micropore volume, and particle size distribution were studied. Only a small swelling was evident at 100 kPa and 873 K, at residence times ~0.14 s. At >873 K, more reactions shifted from the micropore region to the macropore region and surface area remained constant during the initial weight loss region and >7O weight loss.
97104632 Characterization of coal-derived pitches as precursors for advanced carbon materials by chromatographic and related techniques Machnikowski, J. et al. J. Chromatogr.. A, 1997, 778, (I + 2), 403-413. Thermal treatment with formation of an intermediate liquid crystal phase (mesophase) is involved in most pitch applications. The nature of the raw material is a crucial factor in the formation, growth and development of mesophase spheres. Therefore an improved understanding of the pitch constitution is essential for both determining the suitability of a given pitch for a specific application and improving the carbonization behaviour. Differences in chemical composition of two selected pitches derived from coat (coal-tar and coal-hydrogenation pitches) have been evaluated by gas chomatography and probe-mass spectrometry of the extrographic fractions. Coal hydrogenation pitch is constituted by a higher amount of neutral polycyclic aromatic hydrocarbons with lower molecular mass and polynuclear aromatic compounds of higher polarity than the coal-tar pitch. These compositional differences can explain the lower residue yield, the higher mesophase formation and the polydispersive size of mesophase spheres as compared to the coal-tar pitch.
1997,
in Australia
Taylor, G. H. Tanso, 1997, 178. 114-I 16. Information is given regarding the carbon-related projects currently underway in Australia. Studies include such varied work as, for example, on anodes and other carbons used in the metallurgical industry, blast furnace cokes, mesophase and mesophase-related carbons, carbon fibres and composites, diamonds, fullerenes and associated carbons, and coalderived products such as soil ameliorants. Some examples are summarized.
Carbon research in the Czech Republic 97104627 Glogar, P. Carbon Carbonnceous Compos. Mater.: Struct.-Prop. R&t., /Corrf./. 1995, (Pub. 1996) 421-425. Edited by Palmer, K. R. et al., World Scientific, Singapore. This review discusses thin layers, composites, biomaterials, carbon separation membranes, electrochemical carbon, carbon electrodes, fullerenes, coal tar pitch, and industrial plants. 97104628 Catalytic cracking of a coal tar in a fluid bed reactor Velegol, D. et al. Powder Tech~ol., 1997, 93, (2), 93-100. Catalytical cracking of a coal tar from mild gasification was conducted in a fluidized-bed reactor. Several commercial catalysts were tested and their effectiveness in decomposing tar and releasing sulfur was compared. The effects of process variables such as temperature and residence time were also tested. It was found that the Linde LZ-Y82 zeolite was the most effective catalyst tested for tar conversion to coke and gases and in converting the sulfur compounds in the tar into hydrogen sulfide. LZ-Y82 cracked most effectively in the temperature range 500-530°C.
Catalytic pyrolysis of tars. A kinetic approach 97104629 Faundez, J. et al. DCMK Tagungsber., 1997, 9703 (Proceedings ICCS ‘97, Volume 2) h25-628. An attempt to describe the catalytic pyrolysis of tars in this proposed kinetic model is presented. Validation of the model is also carried out through the pyrolysis of twq tars of different characteristics and origin. Calcined limestone (1I m-/g) was used as catalyst. The model assumes that tars are composed of two pseudocomponents: (i) heavy tar, and (ii) light tar. Tar pyrolysis is described by two simultaneous chemical reactions; catalyst deactivation due to carbon deposition is also considered. After mathematical resolution, expressions for product’s concentration as functions of residence time. selectivity and the deactivation were obtained. Char gasification in fluidized bed with CO* 97104630 Tang, Z. et al. Ranshao Kexrte Yu Jishu., 1996, 2, (1) 31-37. (In Chinese) Char gasification took place in a @-48mm fluidized bed with CO? over the temperature range of 900-1100°C and gas flow range of 170-360 mlimin. The results show that the rate of gasification was controlled by kinetic and transfer rate, and there is a critical temperature between lOOO-1050°C. The experiment results were calculated with three models and an activation energy of 80 and 155 kJ/mol was found.
97104633 Chemical evolution of cementitious high proportion of fly ash and slag
materials
with
Chemical Degrad. Cem. -Based $wt., Proc. Bakharev, T. et al. Mechanical Mater. Res. Sot. Symp., 1997, 307-314. Edited by Scrivener, K. L. and Young, J. F., E & FN Span, London, UK. In order to assess their suitability to immobilize simulated off-gas waste solutions, cement mixtures containing high proportions of slag and fly ash were tested. Materials were mixed with carbonated or alkali solutions and cured, initially adiabatically, then at 70°C. Chemical changes were monitored for 7 months using X-ray diffraction, selective dissolution and SEM; NMR was utilized to follow the polymerization of silicate species. Over the first months of curing the process of hydration was characterized by formation of quite crystalline Al-substituted C-S-H structurally related to 1.1 nm tobermorite and traces of zeolites in some materials. Calcium hydroxide content was low in all materials after I month of curing. Rapidly decreasing porosity was shown by SEM, giving the mixtures long-term durability.
97104634 Chemically flv ash based cement
activated
fly ash (CAFA):
a new type of
Rbstami, H. and Silverstrim, T. Proc. Annu. Int. Pittsburgh Coal Con/; 1996. 13th. (21. 11)74-lfl79. Chemical Activated Fly-Ash (CAFA) is a new cementitious material, which is used to produce concrete for construction. CAFA can be used to create a variety of concrete strengths and could revolutionize the concrete product manufacturing industry due to its economy. CAFA contains 80-95% Class F fly ash and is used as cement to bind sand, stone, and fibres creating concrete. CAFA concrete has been tested for strength, durability, mechanical properties and, most importantly, economic viability and was found to be economically and technically viable for many construction applications. Some properties include rapid strength gain (90% of Ultimate in I day), high ultimate strengths (16,000 psi in 1 day), excellent acid resistance, and freeze thaw durability. CAFA’s resistance to chemical attack, such as sulfuric (HzS04), nitric (HN02), hydrochloric (HCI), and organic acids, is far better than portland cement concrete. Near term applications of CAFA material are, block, pipe. burial vaults, median barriers, sound barriers, and overlaying materials. High strength construction products, bridge beams, pre-stressed members, concrete tanks, highway appurtenances, and other concrete products are targeted as eventual markets.
97104635 Chemically modified wasted fly ash from the Konin power plant and its adsorption properties Pol. J. Environ. Stud., 1997, 6, (2), Sarbak, Z. and Kramer-Wachowiak, M. 53-57. Power plant waste fly ash was modified by treatment with NaOH, NHdHCOj and NaOH, RCI, or EDTA. Chemically modified lignite fly ash showed a zeolite-like structure resulting from X-ray diffraction, IR spectroscopy, and thermogravimetry examinations. The zeolitized coal ash samples are effective adsorbents for n-butylamine removal.
Fuel and Energy Abstracts
November
1997
401
04 97104623
BY-PRODUCTS TO FUELS Algicidal
and fungicidal
concrete
treatment
on fabrication
of
Yasuda. E. er al. Carbon Carbonaceous Compos. Mater.: Stnrct:Prop. Relat., /Conf.j. 1995, (Pub. 1996), 409-417. Edited by Palmer, K. R. et al., World Scientific. Singapore. The effect of iodine treatment on fabrication of pitch based carbon fibrei carbon matrix composites was investigated. Coal tar pitch having the softening point of 101°C was used as a matrix precursor in this research. The specimen, 20 mm.’ in size and Vr = 43%. was put into a test tube with iodine powder. After sealing the tube, the specimen was heated at 90’C for iodine treatment. The iodine-treated specimens were heated at a rate of 2.5”Cimin up to 800°C in Ar flow for carbonization. Carbon yield of the specimen increased from 73 to 93% after 20 h of iodine treatment. For the 20 h-treated specimen, the matrix pitch did not flow out from the fibre bundle after carbonization. As the iodine treatment period increased, optical microstructure of the matrix in the carbonized specimens changed from a flow type texture to a mosaic one. 97104625
calcium
Binder compositions containing chloride, and lime component
fly ash, gypsum,
Russ. RU 2,077,516 (Cl. C04B7/28), Elesin, S. M. et al. Appl. 94,032,X07, 8 Sep 1994. (In Russian)
97104626
Some carbon-related
activities
20 Apr
related to fuels
97104631 Characteristics of chars produced from devolatilization of Yallourn brown coal at elevated pressure Yeasmin, H. et al. DGMK Tagungsber., 1997, 9703, (Proceedings ICCS ‘97.
RELATED
Maruyama, T. er al. Jpn. Kokai Tokkyo Koho JP 09 02,859 (97 02.8591 (Cl. CO4B28102). 7 Jan 1997, Appl. 95/155,001. 21 Jun 1995, 6 pp. (In Japanese) In the preparation of the concrete, the following are mixed: (A) concrete raw materials containing cement and aggregates, (B) algicides and fungicides, and, for example, selective organic herbicides and/or bactericidal inorganic metal ions, preferably Ag ions, and (C) SiOz fume, fly ash and/or powered blast furnace slags. The herbicides are added to readymixed concrete prepared from A and C and water in an amount of 0.3-6 kg/ m’, and the concrete is used in building.
Application of iodine 97104624 pitch based C/C composites
By-products
Volume 2), 689-692. Yallourn brown coal was devolatized under rapid heating conditions in pressurized drop-tube furnace using a sample of size fraction 37-53 rrm. Tests were carried out under a Nz atmosphere at pressures of 100 and 500 kPa, temperatures of 873, 1073, and 1273 K, and at residence times ranging from 0.2 to 2 s. For each run, weight loss was determined. Char structural parameters, such as CO2 surface area, true densities, micropore volume, and particle size distribution were studied. Only a small swelling was evident at 100 kPa and 873 K, at residence times ~0.14 s. At >873 K, more reactions shifted from the micropore region to the macropore region and surface area remained constant during the initial weight loss region and >7O weight loss.
97104632 Characterization of coal-derived pitches as precursors for advanced carbon materials by chromatographic and related techniques Machnikowski, J. et al. J. Chromatogr.. A, 1997, 778, (I + 2), 403-413. Thermal treatment with formation of an intermediate liquid crystal phase (mesophase) is involved in most pitch applications. The nature of the raw material is a crucial factor in the formation, growth and development of mesophase spheres. Therefore an improved understanding of the pitch constitution is essential for both determining the suitability of a given pitch for a specific application and improving the carbonization behaviour. Differences in chemical composition of two selected pitches derived from coat (coal-tar and coal-hydrogenation pitches) have been evaluated by gas chomatography and probe-mass spectrometry of the extrographic fractions. Coal hydrogenation pitch is constituted by a higher amount of neutral polycyclic aromatic hydrocarbons with lower molecular mass and polynuclear aromatic compounds of higher polarity than the coal-tar pitch. These compositional differences can explain the lower residue yield, the higher mesophase formation and the polydispersive size of mesophase spheres as compared to the coal-tar pitch.
1997,
in Australia
Taylor, G. H. Tanso, 1997, 178. 114-I 16. Information is given regarding the carbon-related projects currently underway in Australia. Studies include such varied work as, for example, on anodes and other carbons used in the metallurgical industry, blast furnace cokes, mesophase and mesophase-related carbons, carbon fibres and composites, diamonds, fullerenes and associated carbons, and coalderived products such as soil ameliorants. Some examples are summarized.
Carbon research in the Czech Republic 97104627 Glogar, P. Carbon Carbonnceous Compos. Mater.: Struct.-Prop. R&t., /Corrf./. 1995, (Pub. 1996) 421-425. Edited by Palmer, K. R. et al., World Scientific, Singapore. This review discusses thin layers, composites, biomaterials, carbon separation membranes, electrochemical carbon, carbon electrodes, fullerenes, coal tar pitch, and industrial plants. 97104628 Catalytic cracking of a coal tar in a fluid bed reactor Velegol, D. et al. Powder Tech~ol., 1997, 93, (2), 93-100. Catalytical cracking of a coal tar from mild gasification was conducted in a fluidized-bed reactor. Several commercial catalysts were tested and their effectiveness in decomposing tar and releasing sulfur was compared. The effects of process variables such as temperature and residence time were also tested. It was found that the Linde LZ-Y82 zeolite was the most effective catalyst tested for tar conversion to coke and gases and in converting the sulfur compounds in the tar into hydrogen sulfide. LZ-Y82 cracked most effectively in the temperature range 500-530°C.
Catalytic pyrolysis of tars. A kinetic approach 97104629 Faundez, J. et al. DCMK Tagungsber., 1997, 9703 (Proceedings ICCS ‘97, Volume 2) h25-628. An attempt to describe the catalytic pyrolysis of tars in this proposed kinetic model is presented. Validation of the model is also carried out through the pyrolysis of twq tars of different characteristics and origin. Calcined limestone (1I m-/g) was used as catalyst. The model assumes that tars are composed of two pseudocomponents: (i) heavy tar, and (ii) light tar. Tar pyrolysis is described by two simultaneous chemical reactions; catalyst deactivation due to carbon deposition is also considered. After mathematical resolution, expressions for product’s concentration as functions of residence time. selectivity and the deactivation were obtained. Char gasification in fluidized bed with CO* 97104630 Tang, Z. et al. Ranshao Kexrte Yu Jishu., 1996, 2, (1) 31-37. (In Chinese) Char gasification took place in a @-48mm fluidized bed with CO? over the temperature range of 900-1100°C and gas flow range of 170-360 mlimin. The results show that the rate of gasification was controlled by kinetic and transfer rate, and there is a critical temperature between lOOO-1050°C. The experiment results were calculated with three models and an activation energy of 80 and 155 kJ/mol was found.
97104633 Chemical evolution of cementitious high proportion of fly ash and slag
materials
with
Chemical Degrad. Cem. -Based $wt., Proc. Bakharev, T. et al. Mechanical Mater. Res. Sot. Symp., 1997, 307-314. Edited by Scrivener, K. L. and Young, J. F., E & FN Span, London, UK. In order to assess their suitability to immobilize simulated off-gas waste solutions, cement mixtures containing high proportions of slag and fly ash were tested. Materials were mixed with carbonated or alkali solutions and cured, initially adiabatically, then at 70°C. Chemical changes were monitored for 7 months using X-ray diffraction, selective dissolution and SEM; NMR was utilized to follow the polymerization of silicate species. Over the first months of curing the process of hydration was characterized by formation of quite crystalline Al-substituted C-S-H structurally related to 1.1 nm tobermorite and traces of zeolites in some materials. Calcium hydroxide content was low in all materials after I month of curing. Rapidly decreasing porosity was shown by SEM, giving the mixtures long-term durability.
97104634 Chemically flv ash based cement
activated
fly ash (CAFA):
a new type of
Rbstami, H. and Silverstrim, T. Proc. Annu. Int. Pittsburgh Coal Con/; 1996. 13th. (21. 11)74-lfl79. Chemical Activated Fly-Ash (CAFA) is a new cementitious material, which is used to produce concrete for construction. CAFA can be used to create a variety of concrete strengths and could revolutionize the concrete product manufacturing industry due to its economy. CAFA contains 80-95% Class F fly ash and is used as cement to bind sand, stone, and fibres creating concrete. CAFA concrete has been tested for strength, durability, mechanical properties and, most importantly, economic viability and was found to be economically and technically viable for many construction applications. Some properties include rapid strength gain (90% of Ultimate in I day), high ultimate strengths (16,000 psi in 1 day), excellent acid resistance, and freeze thaw durability. CAFA’s resistance to chemical attack, such as sulfuric (HzS04), nitric (HN02), hydrochloric (HCI), and organic acids, is far better than portland cement concrete. Near term applications of CAFA material are, block, pipe. burial vaults, median barriers, sound barriers, and overlaying materials. High strength construction products, bridge beams, pre-stressed members, concrete tanks, highway appurtenances, and other concrete products are targeted as eventual markets.
97104635 Chemically modified wasted fly ash from the Konin power plant and its adsorption properties Pol. J. Environ. Stud., 1997, 6, (2), Sarbak, Z. and Kramer-Wachowiak, M. 53-57. Power plant waste fly ash was modified by treatment with NaOH, NHdHCOj and NaOH, RCI, or EDTA. Chemically modified lignite fly ash showed a zeolite-like structure resulting from X-ray diffraction, IR spectroscopy, and thermogravimetry examinations. The zeolitized coal ash samples are effective adsorbents for n-butylamine removal.
Fuel and Energy Abstracts
November
1997
401