Young Bok Ryu

Surfactant effects on SF6 hydrate formation

Sulfur hexafluoride (SF(6)) has been widely used in a variety of industrial processes, but it is one of the most potent greenhouse gases. For this reason, it is necessary to separate or collect it from waste gas streams. One separation method is through hydrate crystal formation. In this study, SF(6) hydrate was formed in aqueous surfactant solutions of 0.00, 0.01, 0.05, 0.15 and 0.20 wt% to investigate the effects of surfactants on the hydrate formation rates. Three surfactants, Tween 20 (Tween), sodium dodecyl sulfate (SDS) and linear alkyl benzene sulfonate (LABS), were tested in a semi-batch stirred vessel at the constant temperature and pressures of 276.2 K and 0.78 MPa, respectively. All surfactants showed kinetic promoter behavior for SF(6) hydrate formation. It was also found that SF(6) hydrate formation proceeded in two stages with the second stage being the most rapid. In situ Raman spectroscopy analysis revealed that the increased gas consumption rate with the addition of surfactant was possibly due to the increased gas filling rate in the hydrate cavity.

Synthesis of Polyglycerol Fatty Acid Ester for Insulating Oil

Offshore wind power is eco-friendly new regeneration energy producing electricity using a strong wind of the sea. Offshore wind power consists of pitch controller, nacelle, blade and transformer. Insulating oil for transformer needed to low pour point, high flash point and biodegradable considering the low temperature of the sea and environmental pollution. In this study, polyglycerol fatty acid ester was prepared polyglycerol and fatty acid using various catalysts for insulating oils. We investigated the effect of catalysts on the yield of polyglycerol fatty acid ester. In addition, we were measured the pour point and flash point of the prepared polyglycerol fatty acid ester.

Drying Characteristics of Succinic acid using the Microwave

Abstract Recently, biodegradable polymers are gaining more and more attention due to international environmental issues. Succinic acid is synthesised by chemical process of hydrogenation. Succinic acid synthesized has certain amount water content. To remove the water contained in succinic acid is used generally by hot air drying process. But recently, microwave drying process having the advantage of shortening the drying time and uniform drying of product are gaining more attention. In this study, hot air drying and microwave drying efficiency were compared at drying process. In addition, we confirmed commercial applicability in microwave drying process of succinic acid. Microwave drying process has higher efficiency than 70% compared with hot air drying process at thickness of 1cm. Economic efficiency were compared through examination of power consumption for complete drying of succinic acid at microwave and hot air dyring Key Words : Drying process, Hot air oven, Microwave, Succinic acid

Synthesis of Glycerol Carbonate from Biomass Glycerol: Focus on the Calcination Temperature

We carried out a reaction in which glycerol carbonate was synthesized by using glycerol and urea. The physical properties of the prepared catalysts were investigated by BET surface area, X-ray diffraction, temperature programmed desorption, and Field-emission scanning electron microcopy. In addition, we confirmed the conversion of the glycerol and the yield of the glycerol carbonate according to calcination temperature. From XRD results, the crystalline of prepared ZnAl2O4 was slowly increased with an increasing of the calcination temperature. When the calcination temperature of ZnAl2O4 was 500 , the conversion of the glycerol was 74.4% and the yield of the glycerol carbonate was 73.3%. The conversion of the glycerol and the yield of the glycerol carbonate can be obtained higher when acid/base ratio is approx. 1. From this result, we may conclude that the acid & base site density and ratio of catalysts were very important parameters in the synthesis of glycerol carbonate from urea and glycerol.