• Clean Technology
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• v.26 no.2
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• pp.102-108
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• 2020

In recent years, packed column has been widely used in separation processes, such as absorption, desorption, distillation, and extraction, in the petrochemical, fine chemistry, and environmental industries. Packed column is used as a contacting facility for gas-liquid and liquid-liquid systems filled with random packed materials in the column. Packed column has various advantages such as low pressure drop, economical efficiency, thermally sensitive liquids, easy repairing restoration, and noxious gas treatment. The performance of a packed column is highly dependent on the maintenance of good gas and liquid distribution throughout a packed bed; thus, this is an important consideration in a design of packed column. In this study, hydraulic pressure drop, hold-up as a function of liquid load, and mass transfer in the air, air/water, and air-NH₃/water systems were studied to find the geometrical characteristic for raschig super-ring experiment dry pressure drop. Based on the results, design factors and operating conditions to handle noxious gases were obtained. The dry pressure drop of the random packing raschig super-ring was linearly increased as a function of gas capacity factor with various liquid loads in the Air/Water system. This result is lower than that of 35 mm Pall-ring, which is most commonly used in the industrial field. Also, it can be found that the hydraulic pressure drop of raschig super-ring is consistently increased by gas capacity factor with various liquid loads. When gas capacity factor with various liquid loads is increased from 1.855 to 2.323 kg^-1/2 m^-1/2 S^-1, hydraulic pressure drop increases around 17%. Finally, the liquid hold-up related to packing volume, which is a parameter of specific liquid load depending on gas capacity factor, shows consistent increase by around 3.84 kg^-1/2 m^-1/2 S^-1 of the gas capacity factor. However, liquid hold-up significantly increases above it.

• Clean Technology
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• v.18 no.1
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• pp.102-110
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• 2012

In this study, the production of bio-diesel from animal oil by esterification and trans-esterification was investigated. There were three different extraction methods for oil extraction from raw animal fat. Heterogeneous catalysts such as Amberlyst-15 and Amberlyst BD-20 and a homogeneous catalyst such as sulfuric acid were used for esterification. Among three catalysts, the removal efficiency of Free Fatty Acid (FFA) was the highest in sulfuric acid. Response surface method was carried out to find the optimal esterification condition of sulfuric acid and methanol. After the esterification under the optimal condition, this animal fat was used for the trans-esterification. Animal oil used for trans-esterification was below 1% of FFA content and 0.09% of water content. The catalysts for trans-esterification were KOH, NaOH and $NaOCH_3$. To investigate the effects of catalyst type and amount on trans-esterification, The amount of catalyst were changed with 0.3, 0.6 and 0.9 wt%. The molar ratio of methanol/oil was changed with 4, 6, 9 and 12. The amount of catalyst was fixed to 0.8 wt%. The KOH catalyst showed the highest FAME conversion for trans- esterification, and the optimal methanol/oil weight ratio was 6. In the experiments of various catalysts and methanol molar ratios, the highest content of FAME is 96%. However, this FAME content was below Korean bio-diesel standard which is 96.5% of FAME content. After distillation, FAME content increased to 98%.