Effect of inorganic additives in limestone on desulfurization efficiency of SO₂ was investigated for dry desulfurization process with powder-particle fluidized bed (PPFB). The addition of inorganic compounds such as sodium chloride and sodium carbonate enhanced the reactivity of calcined lime powder with SO₂ in the PPFB. When 2wt% Na₂CO₃ or NaCl was added into limestone, the pore structure of lime powder was changed and SO₂ removal capacity was enhanced. In particular, Na₂CO₃ addition resulted in higher SO₂ removal efficiency than NaCl. When the average residence time of gas in the bed is as short as 0.1s, the SO₂ removal efficiency reached almost 100% at 1173K and Ca/S molar ratio of 2 for 7μm sorbent powder prepared from limestone with 2wt% Na₂CO₃, while for 5.3μm untreated lime, the corresponding SO₂ removal efficiency was 70%.

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Metallic alloy particles of silver (Ag) and palladium (Pd) in submicron size range were prepared using an ultrasonic spray pyrolysis of AgNO₃ and Pd (NO₃)₂ solutions. The particles were prepared with two distinct heating pattterns. One is the heating of droplets at a constant temperature in a pyrolyzing furnace, where the temperature was kept at the same value from the entrance to the exit. The other is the heating of droplets with gradually-increasing temperature from entrance to exit. The exit temperature was set at the same temperature as that for the constant heating. TG mass change of particle during oxidization in air was examined. The mass change at stepwise heating was lower than that at constant heating for high Pd/Ag ratio. The oxidation mechanism was investigated by thermal analysis and compared with the thermal decomposition difference between AgNO₃ and Pd (NO₃)₂ solutions.

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Vacuum filtration tests of Korean kaolin slurry were conducted under various filtration pressures using a nutsche equipped with a floating disk. The floating disk was used to determine the filtrate volume by its displacement. The average porosity of filter cake was obtained based on the principle of sudden reduction of filtration area during filtration. Compression-permeability cell data such as the local specific filtration resistance and the local porosity were evaluated as functions of the local solid compressive pressure on the basis of vacuum filtration data. The expression characteristics of slurry under relatively large expression pressure conditions were well evaluated based on the compression-permeability cell data determined from the vacuum filtration data under low pressure conditions. In addition, an approximate method has been developed for obtaining the permeability data on the basis of expression data.

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We quantitatively investigated a process for concentrating and desalinating bovine serum albumin (BSA) in potassium chloride solution by multi-stage operation with superabsorbent-crosslinked hydrogels. The process employs swelling of gel particles by the absorption of water and electrolyte with exclusion of protein molecules. In the two-stage operation, the concentrated solution was diluted with water, and then other gels were added to the diluted solution in order to further concentrate the protein. As a result, the solution was effectively concentrated and desalinated with the superabsorbent hydrogels, and the characteristics of concentration and desalination of a protein solution by multi-stage operations are well expressed by the swelling behavior of superabsorbent hydrogels for a variety of electrolyte concentrations. Furthermore, the optimum dosage of gel particles in each stage was also determined.

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