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High Solid Loading (high + solid_loading)
Selected AbstractsDispersion Behavior of ZrB2 Powder in Aqueous SolutionJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 11 2007Sea-Hoon Lee Dispersion conditions of ZrB2 powder in water were investigated using poly(ethyleneimine) (PEI) as a dispersant. Pulverization of ZrB2 powder to submicrometer size was difficult and a substantial amount of large particles remained after an intensive planatery milling for 72 h. The isoelectric point (IEP) of ZrB2 powder was measured to be pH 5.8 by electrophoresis, which shifted to pH 6.2 after milling. The application of PEI changed the IEP of the boride slurry to ,pH 11. Well-dispersed aqueous ZrB2 slurries with a high solid loading (up to 45 vol%) were fabricated at pH 6.5,7.5 by the application of 1.5 wt% PEI. [source] Improvement of the Dispersion of Al2O3 Slurries Using EDTA-4NaJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 4 2006Jingxian Zhang Polyacrylic acid (PAA) is known to be an effective dispersant for Al2O3 powder in aqueous media. However, at high solid loading (>55 vol%), the dispersion of the Al2O3 suspensions became difficult with only PAA as a dispersant. In this paper, ethylenediaminetetraacetic acid, tetrasodium salt, dihydrate (EDTA-4Na) was introduced to improve the dispersion of the Al2O3 suspensions. With the aid of EDTA-4Na, the adsorption amount of sodium polyacrylic acid (PAA-Na) increased, while the apparent viscosity of 60 vol% Al2O3 slurries decreased significantly. Particle size measurements showed that EDTA-4Na could help to reduce larger agglomerates, possibly by modifying the adsorbed layer thickness. The interactions between EDTA-4Na and PAA-Na were studied using Fourier-transform infrared spectroscopy analysis. Results showed that it was possible to introduce EDTA-4Na as the second dispersant to improve the dispersion of high solid content Al2O3 slurries. [source] Alkali-based AFEX pretreatment for the conversion of sugarcane bagasse and cane leaf residues to ethanolBIOTECHNOLOGY & BIOENGINEERING, Issue 3 2010Chandraraj Krishnan Abstract Sugarcane is one of the major agricultural crops cultivated in tropical climate regions of the world. Each tonne of raw cane production is associated with the generation of 130,kg dry weight of bagasse after juice extraction and 250,kg dry weight of cane leaf residue postharvest. The annual world production of sugarcane is ,1.6 billion tones, generating 279 MMT tones of biomass residues (bagasse and cane leaf matter) that would be available for cellulosic ethanol production. Here, we investigated the production of cellulosic ethanol from sugar cane bagasse and sugar cane leaf residue using an alkaline pretreatment: ammonia fiber expansion (AFEX). The AFEX pretreatment improved the accessibility of cellulose and hemicelluloses to enzymes during hydrolysis by breaking down the ester linkages and other lignin carbohydrate complex (LCC) bonds and the sugar produced by this process is found to be highly fermentable. The maximum glucan conversion of AFEX pretreated bagasse and cane leaf residue by cellulases was ,85%. Supplementation with hemicellulases during enzymatic hydrolysis improved the xylan conversion up to 95,98%. Xylanase supplementation also contributed to a marginal improvement in the glucan conversion. AFEX-treated cane leaf residue was found to have a greater enzymatic digestibility compared to AFEX-treated bagasse. Co-fermentation of glucose and xylose, produced from high solid loading (6% glucan) hydrolysis of AFEX-treated bagasse and cane leaf residue, using the recombinant Saccharomyces cerevisiae (424A LNH-ST) produced 34,36,g/L of ethanol with 92% theoretical yield. These results demonstrate that AFEX pretreatment is a viable process for conversion of bagasse and cane leaf residue into cellulosic ethanol. Biotechnol. Bioeng. 2010;107: 441,450. © 2010 Wiley Periodicals, Inc. [source] Particle Size of Pneumatically Conveyed Powders Measured Using Impact DurationPARTICLE & PARTICLE SYSTEMS CHARACTERIZATION, Issue 6 2007Peter J. Coghill Abstract CSIRO Minerals has developed a technique for measuring particle size in pneumatically conveyed powders [1] by measurement of the acoustic waves produced by particle impacts upon a specially designed transducer. Previous work has focused on using the peak acoustic wave amplitude to determine particle size. This produces a spectrum that is hard to determine the particle size from, as the peak amplitude is a non-linear function of particle diameter, and is strongly affected by angle of incidence and velocity of the impacting particle. In this paper impact duration measurements are used to overcome these difficulties while retaining the advantages of being able to measure in high solids loadings of up to at least 0.5,kg/m3 of powder. In laboratory tests the impact size monitor's (ISM) results have been correlated with optical diffraction measurements of the mean (by number) powder size with a correlation coefficient of 0.985 and a relative error of 5.5,%. The ISM operated successfully in the laboratory at a loading of 0.5,kg/m3 of powder and measured particles down to 50,microns in size. [source] | ||||||||||