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Ceramic membrane apparatus and method for separating gases such as In removal of carbon dioxide from methane
12 Refractories/ceramics
12
Properties, production, 03/01420 iwwrzg
applications
Ceramic membrane apparatus and method for gaws such as in removal of carbon dioxide from
Gobina, E. PCT Int. Appl. WO 02 74,421 (Cl. BOlD53/22), 26 Sep 2002, GB Appl. 2001/6,478. A mixture of gases, such as carbon dioxide and methane, are separated by an inorganic membrane comprising a ceramic support and a silica layer. The invention can efficiently separate the gaseous mixture and can also cope with the extreme conditions found in e.g. hydrocarbonproducing wells and in methane-containing biogas from landfills.
03/01421 Coapoettions for glass ceramics and marbieiike glasses produced from coat ash with modffyirfg adcNtlves Raichel, A. and Raichel, S. U.S. Pat. Appl. Publ. US 2002 132,722 (Cl. Cl. 501-155; CO4B35/00), 19 Sep 2002, US Appl. PV259,901. The invention relates to a crystal composition, a polycrystal product and an article of manufacture comprising an amount of SiOz, AI203, CaO, FezOj, TiOl, KzO, PzOsr Cr203, ZnO, MgO, NazO, LizO, CeOz, ZrOz and MnOz and methods for preparation. The crystal composition may be obtained from a coal ash waste with glass-forming component(s), and a crystallization aid. The present invention provides for obtaining and using coal ash for the production of glass-ceramic polycrystal products, and is particularly applicable to coal ash that contains large amounts of calcium oxide and metals such as iron, manganese, chromium, titanium. Thus, cordierite glass-ceramic was produced from coal fly ashes from different sources to adjust the composition to produce a cordierite phase. The ratio AlzOs:SiOz in the ashes approximately corresponded to cordierite without MgO, so magnesium salts were added to crystallization. Catalysts used were titanium dioxide, chromium oxide and/or zinc oxide. The coloured glass-ceramics produced were of black and light- and dark brown colour; coloured with a shining and non-glossy surface; and coloured marblelike products with intense black colour.
Current status of dense ceramic membranes for hydrogen separation
03/01422
Conference
U. et al. Proceedings of the International Technical on Coal Urilization & Fuel Systems, 2002, 2, (27), 1155-
1165. Novel cermet (i.e. ceramic metal composite) membranes have been developed for separating hydrogen from gas mixtures at high temperature and pressure. The hydrogen permeation rate in the temperature range of 600-900°C has been measured for three classes (ANL-1, -2, and -3) of cermet membranes. ANL-3 membranes provide the highest hydrogen flux (16.2 cm3(STP)/min-cm’ for 40 pm-thick ANL-3a at 900°C using 100% Hz as the feed gas). The effects of membrane thickness and hydrogen partial pressure on the hydrogen flux indicate that the bulk diffusion of hydrogen is rate-limiting for ANL-3 membranes with thickness >0.04 mm. ANL-3b membranes were tested in simulated syngas at several temperatures for times approaching -200 h, and no degradation in performance was observed. The lack of degradation in simulated syngas suggests that the membrane is chemical stable and may be suitable for long-term operation.
03/01423 Effect of inclination angle on the tight trwemiHtmoe Ot cendensate covered homogeneous thin trawparent mate&is Pollet, I. V. and Pieters, 2002,
J. G. Solar Energy Materials and Solar Cells,
73, (4), 435439.
The inclination angle of a transparent material exposed to solar radiation strongly varies depending on the application. It is well known that the inclination angle can highly influence the shape of condensation drops - which are sometimes unavoidable in solar thermal applications - via its effect on the receding and advancing contact angles of the drops. By means of a laboratory set-up, the effect of condensate on the transmittance of 25” and 90” (i.e. vertical) inclined single glass, polyethylene and anti-drop condensation polyethylene was measured for incidence angles up to 45”. No significant impact of the inclination angle on the transmittance of the three transparent materials in the wet state was observed. This means that transmittance results obtained on wet materials can be applied irrespective of the inclination angle of the material.
applications)
modulus and
Xie, X.-.Q. et al. Zeitschrifr fuer Metallkunde, 2002, 93, (6), 559-564. The eIastic modulus and damping capacity of woodceramics (porous carbon) have been investigated by using a dynamic mechanical thermal anaIyser. The elastic modulus of woodceramics decreases with increasing temperature. The values are almost independent of vibration frequency, show different variation with strain amplitude for different woodceramics, and increase with increasing sintering temperature Woodceramics exhibit significant damping gains, especially at room temperature, higher strain amplitudes, and higher vibration frequencies. The damping capacity increases with increasing vibration frequency and strain amplitude, decrease with increasing temperature and sintering temperature. Defect damping, including point defect damping, interface damping, and micropore/microcrack damping is supposed to be the main contributor to the damping of woodceramics. At elevated temperatures interface damping is likely to responsible for the majority of the damping.
influence of gas emission on heat transfer in porous ceramics
03/01425
T. International 2003, 46, (3), 385-397.
Gambaryan-Roisman, Transfer,
Balachandran,
_v=oaatk
a
REFRACTORIES/ CERAMICS
(properties, production,
Journal
of‘ Heat
aud
Mass
It is known that thermal diffusivity, a, of several types of porous ceramic and refractory materials decreases with decreasing gas pressure. However, a of several ceramics (e.g. magnesite refractories with porosity about 25%) measured in vacuum by the monotonous heating exceeds the comparable data registered at atmospheric pressure. A similar effect was found for thermal diffusivity of several insulating materials. However, for some porous ceramics this phenomenon is absent or less prominent. It had been known that several heterogeneous physico-chemical processes take place on pore surfaces of ceramic materials. These processes include heterogeneous chemical reactions accompanied by emission of gaseous products. It had been conjectured that these processes affect thermophysical properties of ceramic materials, especially during fast heating or cooling. In this study a quantitative model was developed for the apparent thermal diffusivity, as measured by the non-stationary monotonous heating method. It takes into account the emission and adsorption of the gas on the opposite pore sides along the temperature gradient, the diffusive gas motion inside the pores and its removal from the pores due to the material gas permeability. The effect of these processes is shown to produce an additional heat flux inside the pore or crack and, hence, to increase the measured thermal diffusivity. In the presence of the passive gas, the rates of gas emission and its transport within the pore are significantly reduced, which leads to diminution of the effect of gas emission-adsorption on the heat transfer across the pore. Consequently, it is shown that this leads to a situation (observed in experiment) where thermal diffusivity of a material measured at high temperature in vacuum may exceed the comparable property at atmospheric pressure. When the reaction terminates due to the full conversion of the available solid reactant, the additional heat flow due to the gas emission and adsorption terminates, and the measured thermal diffusivity decreases. The rates of gas removal and of chemical conversion depend on the amount of reactant available within the specimen and on the heating rate. It is shown that as a result of this, the measured thermophysical properties depend on the material thermal history and heating parameters, and, hence, cannot be regarded as true material properties. 0301426 Mechanical aspect on drying of wet porous media Kowalski, S. J. Porous Media, 2002, 169-197. Edited by Ehlers. Wolfgang; Bluhm, Joachim An aspect of thermomechanics of fluid saturated capillary-porous media concerning the mechanical phenomena accompanying the heat and mass transfer during drying processes is presented. The wet materials tend to shrink during drying and the shrinkage generates internal stresses, which may cause fracturing of the dried body. The constitutive relations and the heat and mass rate equations are developed. The forces that produce shrinkage and the mechanisms responsible for transport of heat and moisture are examined. The considerations are based on the thermodynamic of irreversible processes and the continuum mechanics of porous media. The studies are quite general but the final form of the drying model is simplified by the assumptions admissible in practical applications. The example of convective drying of a ceramic cylinder is presented for illustration of the theory.
03IO1427
Practlcai improvements in CaO-swelling cements
D. and Reichetseder, P. Journal of Petroleum Science and Engineering, 2002, 36, (l-2), 61-70. Calcium oxide-swelling cement expansion behaviour was studied to improve results of annular sealing during well cementing and underground gas storage. Calcium oxide cement compositions expand during hardening. Cement slurry expansion, resistance to flow (to assess
Appah,
Fuel and Energy Abstracts
July 2003 251
12
Properties, production, 03/01420 iwwrzg
applications
Ceramic membrane apparatus and method for gaws such as in removal of carbon dioxide from
Gobina, E. PCT Int. Appl. WO 02 74,421 (Cl. BOlD53/22), 26 Sep 2002, GB Appl. 2001/6,478. A mixture of gases, such as carbon dioxide and methane, are separated by an inorganic membrane comprising a ceramic support and a silica layer. The invention can efficiently separate the gaseous mixture and can also cope with the extreme conditions found in e.g. hydrocarbonproducing wells and in methane-containing biogas from landfills.
03/01421 Coapoettions for glass ceramics and marbieiike glasses produced from coat ash with modffyirfg adcNtlves Raichel, A. and Raichel, S. U.S. Pat. Appl. Publ. US 2002 132,722 (Cl. Cl. 501-155; CO4B35/00), 19 Sep 2002, US Appl. PV259,901. The invention relates to a crystal composition, a polycrystal product and an article of manufacture comprising an amount of SiOz, AI203, CaO, FezOj, TiOl, KzO, PzOsr Cr203, ZnO, MgO, NazO, LizO, CeOz, ZrOz and MnOz and methods for preparation. The crystal composition may be obtained from a coal ash waste with glass-forming component(s), and a crystallization aid. The present invention provides for obtaining and using coal ash for the production of glass-ceramic polycrystal products, and is particularly applicable to coal ash that contains large amounts of calcium oxide and metals such as iron, manganese, chromium, titanium. Thus, cordierite glass-ceramic was produced from coal fly ashes from different sources to adjust the composition to produce a cordierite phase. The ratio AlzOs:SiOz in the ashes approximately corresponded to cordierite without MgO, so magnesium salts were added to crystallization. Catalysts used were titanium dioxide, chromium oxide and/or zinc oxide. The coloured glass-ceramics produced were of black and light- and dark brown colour; coloured with a shining and non-glossy surface; and coloured marblelike products with intense black colour.
Current status of dense ceramic membranes for hydrogen separation
03/01422
Conference
U. et al. Proceedings of the International Technical on Coal Urilization & Fuel Systems, 2002, 2, (27), 1155-
1165. Novel cermet (i.e. ceramic metal composite) membranes have been developed for separating hydrogen from gas mixtures at high temperature and pressure. The hydrogen permeation rate in the temperature range of 600-900°C has been measured for three classes (ANL-1, -2, and -3) of cermet membranes. ANL-3 membranes provide the highest hydrogen flux (16.2 cm3(STP)/min-cm’ for 40 pm-thick ANL-3a at 900°C using 100% Hz as the feed gas). The effects of membrane thickness and hydrogen partial pressure on the hydrogen flux indicate that the bulk diffusion of hydrogen is rate-limiting for ANL-3 membranes with thickness >0.04 mm. ANL-3b membranes were tested in simulated syngas at several temperatures for times approaching -200 h, and no degradation in performance was observed. The lack of degradation in simulated syngas suggests that the membrane is chemical stable and may be suitable for long-term operation.
03/01423 Effect of inclination angle on the tight trwemiHtmoe Ot cendensate covered homogeneous thin trawparent mate&is Pollet, I. V. and Pieters, 2002,
J. G. Solar Energy Materials and Solar Cells,
73, (4), 435439.
The inclination angle of a transparent material exposed to solar radiation strongly varies depending on the application. It is well known that the inclination angle can highly influence the shape of condensation drops - which are sometimes unavoidable in solar thermal applications - via its effect on the receding and advancing contact angles of the drops. By means of a laboratory set-up, the effect of condensate on the transmittance of 25” and 90” (i.e. vertical) inclined single glass, polyethylene and anti-drop condensation polyethylene was measured for incidence angles up to 45”. No significant impact of the inclination angle on the transmittance of the three transparent materials in the wet state was observed. This means that transmittance results obtained on wet materials can be applied irrespective of the inclination angle of the material.
applications)
modulus and
Xie, X.-.Q. et al. Zeitschrifr fuer Metallkunde, 2002, 93, (6), 559-564. The eIastic modulus and damping capacity of woodceramics (porous carbon) have been investigated by using a dynamic mechanical thermal anaIyser. The elastic modulus of woodceramics decreases with increasing temperature. The values are almost independent of vibration frequency, show different variation with strain amplitude for different woodceramics, and increase with increasing sintering temperature Woodceramics exhibit significant damping gains, especially at room temperature, higher strain amplitudes, and higher vibration frequencies. The damping capacity increases with increasing vibration frequency and strain amplitude, decrease with increasing temperature and sintering temperature. Defect damping, including point defect damping, interface damping, and micropore/microcrack damping is supposed to be the main contributor to the damping of woodceramics. At elevated temperatures interface damping is likely to responsible for the majority of the damping.
influence of gas emission on heat transfer in porous ceramics
03/01425
T. International 2003, 46, (3), 385-397.
Gambaryan-Roisman, Transfer,
Balachandran,
_v=oaatk
a
REFRACTORIES/ CERAMICS
(properties, production,
Journal
of‘ Heat
aud
Mass
It is known that thermal diffusivity, a, of several types of porous ceramic and refractory materials decreases with decreasing gas pressure. However, a of several ceramics (e.g. magnesite refractories with porosity about 25%) measured in vacuum by the monotonous heating exceeds the comparable data registered at atmospheric pressure. A similar effect was found for thermal diffusivity of several insulating materials. However, for some porous ceramics this phenomenon is absent or less prominent. It had been known that several heterogeneous physico-chemical processes take place on pore surfaces of ceramic materials. These processes include heterogeneous chemical reactions accompanied by emission of gaseous products. It had been conjectured that these processes affect thermophysical properties of ceramic materials, especially during fast heating or cooling. In this study a quantitative model was developed for the apparent thermal diffusivity, as measured by the non-stationary monotonous heating method. It takes into account the emission and adsorption of the gas on the opposite pore sides along the temperature gradient, the diffusive gas motion inside the pores and its removal from the pores due to the material gas permeability. The effect of these processes is shown to produce an additional heat flux inside the pore or crack and, hence, to increase the measured thermal diffusivity. In the presence of the passive gas, the rates of gas emission and its transport within the pore are significantly reduced, which leads to diminution of the effect of gas emission-adsorption on the heat transfer across the pore. Consequently, it is shown that this leads to a situation (observed in experiment) where thermal diffusivity of a material measured at high temperature in vacuum may exceed the comparable property at atmospheric pressure. When the reaction terminates due to the full conversion of the available solid reactant, the additional heat flow due to the gas emission and adsorption terminates, and the measured thermal diffusivity decreases. The rates of gas removal and of chemical conversion depend on the amount of reactant available within the specimen and on the heating rate. It is shown that as a result of this, the measured thermophysical properties depend on the material thermal history and heating parameters, and, hence, cannot be regarded as true material properties. 0301426 Mechanical aspect on drying of wet porous media Kowalski, S. J. Porous Media, 2002, 169-197. Edited by Ehlers. Wolfgang; Bluhm, Joachim An aspect of thermomechanics of fluid saturated capillary-porous media concerning the mechanical phenomena accompanying the heat and mass transfer during drying processes is presented. The wet materials tend to shrink during drying and the shrinkage generates internal stresses, which may cause fracturing of the dried body. The constitutive relations and the heat and mass rate equations are developed. The forces that produce shrinkage and the mechanisms responsible for transport of heat and moisture are examined. The considerations are based on the thermodynamic of irreversible processes and the continuum mechanics of porous media. The studies are quite general but the final form of the drying model is simplified by the assumptions admissible in practical applications. The example of convective drying of a ceramic cylinder is presented for illustration of the theory.
03IO1427
Practlcai improvements in CaO-swelling cements
D. and Reichetseder, P. Journal of Petroleum Science and Engineering, 2002, 36, (l-2), 61-70. Calcium oxide-swelling cement expansion behaviour was studied to improve results of annular sealing during well cementing and underground gas storage. Calcium oxide cement compositions expand during hardening. Cement slurry expansion, resistance to flow (to assess
Appah,
Fuel and Energy Abstracts
July 2003 251