• Membrane Journal
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• v.33 no.6
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• pp.352-361
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• 2023

Steam methane reforming is currently the most widely used technology for producing hydrogen, a clean fuel. Hydrogen produced by steam methane reforming contains impurities such as carbon monoxide, and it is essential to undergo an appropriate post-purification step for commercial usage, such as fuel cells. Recently, membrane separation technology has been gaining great attention as an effective purification method; in this study, we evaluated the feasibility of using commercial polysulfone membranes for biogas upgrading to separate and recover hydrogen from a hydrogen/carbon monoxide gas mixture. Initially, we examined the physicochemical properties of the commercial membrane used. We then conducted performance evaluations of the commercial membrane module under various conditions using mixed gas, considering factors such as stage-cut and operating pressure. Finally, based on the evaluation results, we carried out simulations for process design. The maximum H₂ permeability and H₂/CO separation factor for the commercial membrane process were recorded at 361 GPU and 20.6, respectively. Additionally, the CO removal efficiency reached up to 94%, and the produced hydrogen concentration achieved a maximum of 99.1%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.181-187
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• 2016

Silica is an essential material in the electronics industries of LCDs and OLEDs, which particularly require high purity. This study attempted to find the optimal design of a magnetic separator for silica sand containing iron compounds using CFD simulation. Three designs of magnetic separation were prepared and their efficiency was examined. As a result of the evaluation, the sufficient contact of particulate silica with the surface of magnetic emitters improved the magnetic separation effects. In addition, the loss of $SiO_2$ and the removal rate of $Fe_2O_3$ depended strongly on the particle size, flow rate and magnetic flux density. In addition, magnetic separation is quite effective for a particle size of $10{\mu}m$ with a 0.2 m/s flow rate.

• Clinical and Experimental Reproductive Medicine
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• v.10 no.2
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• pp.1-11
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• 1983

${\beta}$-Glucuronidase from bull seminal plasma was partially purified by $(NH_4)_2SO_4$fractionation, two successive DEAE-cellulose columns, isoelectric focusing (pH 4 to 6) and Gel filtration on Sephadex G-200. Only one form of ${\beta}$-glucuronidase was obtained by isoelectric focusing at pH 5.13. Highly purified ${\beta}$-glucuronidase had specific activity of 34 units/mg protein and showed one major and some minor contaminants by disc gelk electrophoresis. The enzyme showed maximum activity at pH 5.2 and at $48^{\circ}C$. The enzyme was completely inhibited by 1,4 saccharo-${\alpha}$-lactone (5 mM). Albumin and 0.15 M NaCl increased the ${\beta}$-glucuronidase activity. Km of ${\beta}$-glucuronidase using phenolphthalein mono-${\beta}$-glucuronic acid as substrate was 2.9 mM and Vmax was $0.8{\mu}$mole/min. The enzyme appeared to be a glycoprotein by its binding to concanvalin·A. Rabbit and human sperm-acrosomal extracts and seminal plasma showed high ${\beta}$-glucuronidase activity.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.915-923
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• 2017

The by-products of red ginseng marc showing the improvement of health has been strongly studied because of the expectation of possibility to be used as the functional foods. This research was to investigate the extraction, separation, isolation, and evaluation of crude acidic polysaccharides related to antioxidant activity, sequently chemical structure of those products was evaluated by FT-IR and NMR. Compared with other solvents such as ethanol, methanol, propanol, acetone, and butanol, ethanol was selected. The concentration of red ginseng solution for extraction was selected as 10%(w/v) related to extraction yield(11.95%) and amount(11.8 mg/ml). In the ion exchange chromatography, aidic polysaccharides showing the highest antioxidant activity was obtained when eluted by distilled water. As results of structural analysis by FT-IR and NMR, peaks corresponding to C-O, C-O-O-, C-H, anomeric C-6, and repeated C-1 and C-6 linkages was to be presumed to be ($1{\rightarrow}6$) glycosidic linkage with the typical acidic polysaccharide.

• Resources Recycling
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• v.23 no.1
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• pp.58-63
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• 2014

Variety of volatile materials is present in crude-Zinc oxide recovered from EAFD(Electric arc furnace steel dust). Commonly, it is purified by oxidizing roasting. In this study, spherical each specimen prepared crude-zinc oxide like 1~3 mm and 10 mm was tested in vertical tube furnace at the temperature range $600^{\circ}C$ to $1200^{\circ}C$ in oxidizing atmosphere. Oxidizing roasting properties of zinc oxide were investigated using XRD, XRF and ICP-OES. At temperature blow $950^{\circ}C$ volatilization rate were remarkably low. As the temperature increases, the concentration of Zn increased and the concentration and XRD peaks of impurities decreased. The result indicated that volatilization rate depended on specimen size and roasting temperature.

• Korean Chemical Engineering Research
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• v.43 no.4
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• pp.467-473
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• 2005

Liquid phase nitrous oxide ($N_2O$) contains air, carbon monoxide, water, carbon dioxide and NOx as main impurities. It is known to be very dangerous to obtain a very pure $N_2O$ product by using solidification at low temperature. In this study a new method to obtain a high purity of $N_2O$ product based on a continuous distillation process was introduced. For the modeling of the continuous distillation process to obtain a product having a purity over 99.999％ of $N_2O$ stream, Intalox wire gauze packing- No. SCH-80S gauze packing column was used. Peng-Robinson equation of state was used for the modeling of the continuous distillation process and refrigeration system. Computational results performed in this work showed a good agreement with Aspen Plus simulation results.

• Resources Recycling
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• v.24 no.4
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• pp.50-55
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• 2015

In this study, we have investigated solvent extraction of Ga and recovery of high pure Ga solution from MOCVD dust for manufacturing of LED chip. Effect of extractan, concentration of extractant were examined for choosing the more effective extractant and high pure Ga solution was fabricated by multi-stage extraction/stripping process. For extraction/separation of Ga based on the analysis of raw-material in previous study, 3 different extractants PC 99A, DP-8R, Cyanex 272 has been investigated and the extraction efficiency of 1.5 M Cyanex 272 was 43.8%. It was conformed that extraction efficiency of Ga was 83% in multi-stage extraction and 5N high purity Ga stripping solution without impurities also obtained.

• KSBB Journal
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• v.21 no.3
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• pp.199-203
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• 2006

Precipitation and reactive distillation were employed to recover lactic acid from fermentation broth. Lime was initially added to fermentation broth in order to convert soluble lactic acid to an insoluble calcium lactate form. Drowning-out crystallization was used to decrease the solubility of calcium lactate by adding ethanol as a co-precipitant. In the ideal solution of organic acids as well as fermentation broth, precipitation experiments were performed with varying amounts of ethanol. Precipitation process was followed by reactive distillation. Carboxylate salts formed in the previous precipitation process were mixed with carbon dioxide and triethylamine to precipitate as calcium carbonate. The remaining liquid was distilled for 1 hr at different temperatures. Triethylamine and water were recovered from the top of the distiller, while organic acids, inducing lactic acid as a main component remained in feeding bottle. The yield of recovered lactic acid was 67.5% with the purity of 99.7%.

• Korean Journal of Microbiology
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• v.41 no.3
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• pp.216-224
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• 2005

Chromatography has now been used successfully to provide the requisite purity for human plasma-derived biop-harmaceuticals such as coagulation factors and immunoglobulins. Recently, increasing attention has been focused on establishing efficient cleaning procedures to prevent potential contamination by microorganisms as well as carry-over contamination from batch to batch. The purpose of present study was to develop a cleaning validation system for the assurance of virus removal and/or inactivation during chromatography process. In order to establish an assay system for the validation of virus clearance during chromatography cleaning process, a quantitative real-time PCR method for porcine parvovirus(PPV) was developed, since PPV, a model virus for human parvovirus B19, has a high resistance to a range of physico-chemical treatment. Specific primers for amplification of PPV DNA was selected, and PPV DNA was quantified by use of SYBR Green I. The sensitivity of the assay was calculated to be 1.5 $TCID_{50}/ml$. The established real-time PCR assay was successfully applied to the validation of PPV removal and cleaning during SP-Sepharose cation chromatography for thrombin purification and Q-Sepharose anion chromatography for factor VIII purification. The comparative results obtained by real-time PCR assay and infectivity titrations suggested that the real-time PCR assay could be a useful method for chromatography cleaning validation and that it could have an additive effect on the interpretation and evaluation of virus clearance during the virus removal process.

• Korean Journal of Pharmacognosy
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• v.5 no.2
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• pp.111-124
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• 1974

The radioactive compound sodium $acetate-U-C^{14}\;(C^{14}-acetate)$ was administered to two- and four-year-old July and September American ginseng (Araliaceae, Panax quinquefolium L.) plants and cuttings. The $C^{14}-acetate$ uptake was approximately 99%. The autoradiochromatograms suggest that the saponins isolated by preparative thin-layer chromatography contained impurities, especially those isolated from the leaf and stem extracts. The root and fruit methanol extracts yielded relatively pure saponins. The large amounts of panaquilin B and its proximity to panaquilin C on preparative thin-layer plates resulted in some admixing. The average concentration (% plant dry weight) of semi-purified saponins were high in the leaves (13.8%), as compared to fruits (9.8%), stems (7.9%) and roots (6.3%). The average percentage of $C^{14}-acetate$ incorporation into panaquilins was 4.8%. The average percentage of $C^{14}-acetate$ incorporation into panaquilins B and C was higher (1.40% and 1.13%, respectively) than that into panaquilins C, (d), G-1 and G-2 (0.75%, 0.65%, 0.13% and 0.53%, respectively). Panaquilin synthesis may be depending upon the part, collection period and age of the plant. The average percentage of $C^{14}-acetate$ incorporation into panaquilin B is high in roots (0.58%) and stems (0.48%); that into panaquilins C and (d) high in leaves (0.40% and 0.45%, respectively); and that into panaquilin E high in roots and leaves (0.55% and 0.50%, respectively). Panaquilin G-2 was synthesized in all parts of plants. The panaquilins appear to be biosynthesized more actively in July than September (exception-panaquilin G-1). Panaquilins B, C and G-1 may be biosynthesized more actively in four-year-old plants and panaquilins (d) and E more actively in two-year-old plants. The results from expectance with cuttings suggest that the panaquilins are synthesized de novo in the above-ground parts of ginseng plants, and that panaquilin G-1 may be synthesized de novo in the leaf. It is known from the tissue culture studies that panaquilins are produced by leaf, stem and root callus tissues and cailus-root cultures of American and Korean ginseng plants. Panaquilins may actively be synthesized de novo in most any cell or organ of the ginseng plants. It was verified that $C^{14}-acetate$ was incorporated into the panaxadiol portions of the panaquilins of two-year-old plants (sp. act. 0.56 mmcCi/mg) and four-year-old plants $(sp.\;act.\;0.54\;m{\mu}Ci/mg)$.