• Journal of Korean Society of Environmental Engineers
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• v.27 no.5
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• pp.491-498
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• 2005

J sewage treatment plant (WWTP) in Busan has used methanol as an external carbon source for the biological denitrification process. Methanol is widely used. but rather expensive and very dangerous in handling. Therefore, it has been required that the economic alternative carbon source must be developed. By-product from a fine chemical industry can be Purified by removing high molecular weight substances using the ultrafilter membrane separation process and RBDCOD fraction becomes $98{\sim}99%$ of COD substances in the purified by-product. The purified by-product containing three types of alcohols, methanol, prophylenglycol and methoxypropanol; showed similar chemical characteristics to the methanol, a main external carbon source, in biodegradation pathway. Shown above, the compatibility between main and alternative carbon sources has been achieved. Also very short or no adaptation period is necessary in the case of exchanging these carbon sources. The compatibility between external carbon sources is an essential element for stabilizing WWTP operations. During the full-scale application test of the by-product, the alternative carbon source line got on par with the treatment efficiency of the methanol line. With the test result, J-WWTP changed methanol to a fine chemical by-product, in two out of three J-WWTP lines. Moreover, it is expected that 55.4% of the external carbon source cost reduction can be achieved in the alternative carbon source applied lines.

• Journal of the Korean Applied Science and Technology
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• v.21 no.3
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• pp.225-230
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• 2004

Synthesis gas is a high valued compound as a basic chemicals at various chemical processes. Synthesis gas is mainly produced commercially by a steam reforming process. However, the process is highly endothermic so that the process is very energy-consuming process. Thus, this study was carried out to produce synthesis gas by the partial oxidation of methane to decrease the energy cost. The effects of reaction temperature and flow rate of reactants on the methane conversion, product selectivity, product ratio, and carbon deposition were investigated with 13wt% Ni/MgO catalyst in a fluidized bed reactor. With the fluidized bed reactor, $CH_4$ conversion was 91%, and Hz and CO selectivities were both 98% at 850$^{\circ}C$ and total flow rate of 100 mL/min. These values were higher than those of fixed bed reactor. From this result, we found that with the use of the fluidized bed reactor it was possible to avoid the disadvantage of fixed bed reactor (explosion) and increase the productivity of synthesis gas.

• Journal of the Korean Chemical Society
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• v.55 no.1
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• pp.92-97
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• 2011

The effect of Group I alkali acetate promoters on vinyl acetate (VA) synthesis was evaluated. Catalyst product selectivity and ethylene conversion are compared to the unpromoted catalyst in the fixed-bed reactor with oxidation reaction of ethylene and acetic acid in gaseous phase over Pd-Au/$SiO_2$ catalyst. It was found that: a) the promoters were stabilized on the catalyst surface, b) common effect for the alkali promoted Pd-Au catalysts increaseed in product selectivity and ethylene conversion compared to unpromoted catalyst (these effects increase from top to the bottom of Group I). These promoting effect is due to the common-ion effect of acetate, present in the reaction, resulting in an increase in the activity of the catalyst. In addition a complementary theory for the effect of Au in the structure of the catalyst is proposed the imposition of distribution of palladium particles through decreasing the particle's diameter.

• Korean Chemical Engineering Research
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• v.49 no.5
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• pp.521-529
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• 2011

Methanol-to-olefin (MTO) reaction was studied over MWW zeolite with independently developed two pores (circular and straight) and MFI zeolite with intercrossed sinusoidal and straight pores in order to investigate the effect of pore structure on their catalytic behavior. MWW and MFI zeolites with similar acidity exhibited commonly high conversion and slow deactivation in the MTO reaction, but their product selectivities were considerably different: linear hydrocarbons of $C_3-C_9$ were mainly produced on MWW, while the yield of $C_2{^=}$ and aromatics were high on MFI. Polyaroamatic hydrocarbons (PAHs) were accumulated on MWW, but a small amount of benzene and aromatics on MFI. The impregnation of phosphorous on MWW caused significant decreases in the catalytic activity and toluene adsorption, but the decreases were relatively small on MFI. Although the straight pores of MWW were inactive in the MTO reaction due to the accumulation of PAHs, its circular pores which suppressed the formation of PAHs sustained catalytic activity for the production of linear hydrocarbons. Therefore, the impregnation of phosphorous on the circular pores of MWW caused a significant decrease in catalytic activity. The phosphorous impregnation on the cross sections of MFI altered the product selectivity due to the neutralization of strong acid sites, but catalytic deactivation was negligible. The difference of MWW and MFI zeolites in the MTO reaction was explained by their difference in pore structure.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.467-476
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• 2023

Schisandra chinensis (S. chinensis) is a deciduous broad-leaved cave plant belonging to the Schisandraceae family and is widely distributed in East Asia including Korea, Japan, China, and Taiwan. It has been reported that the main components contained in S. chinensis include lignan compounds and triterpenoid compounds. To distinguish the characteristics of S. chinensis by production region of Korea, a discriminant was established by performing metabolite profiling and principal component analysis, a multivariate statistical analysis technique. As a result, 16 types of triterpenoids, 9 types of lignan, and 1 type each of flavonoid, phenylpropanoid, and fatty acid were identified. In addition, through multivariate statistical analysis, it was confirmed that the four groups in Danyang, Moongyeong, Geochang, and Pyeongchang were divided, by applying the s-plot model of orthogonal partial least squares discriminant analysis. Biomarkers were identified: lanostane, cycloartane, schiartane triterpenoid, and dibenzocyclo-octadiene lignan were identified as chemical markers, respectively.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.05a
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• pp.217-220
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• 2001

In the shearing process the burr or rollover must be minimized in order to improve the quality of product. The burr size can be minimized by control of several process parameters. But removal of all burrs are impossible. Most mechanical type deburring methods (vibrating bowls, rotating barrels, shot blasting, for example.) will remove large burrs, other methods use chemical (electro-chemical deburring) or heat (thermal energy deburring). The electro-chemical deburring process removes burrs by the deplating method. Electro-chemical deburring equipment is requires a small capital investment than other methods(mechanical or thermal methods). Electro-chemical deburring method need to many parameters for control such as a time, voltage and concentration of electrolyte. In this paper shows relations of these parameters by experiment.

• Natural Product Sciences
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• v.9 no.4
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• pp.213-219
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• 2003

Five aromatic compounds, of which two are new glucosides, and six flavonols were isolated and identified for the first time from the flower heads and aerial shoots of Helichrysum conglobatum (Asteraceae). Their structures were established on the basis of chemical and spectroscopic methods including UV, MS, 1D- and 2D-NMR. Some fractions and isolates were screened for anti-microbial activities. This is the first report of the isolation of the chemical constituents of this species.

• The Korean Journal of Pesticide Science
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• v.8 no.2
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• pp.129-136
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• 2004

In order to determine the amounts of impurities and to identify the chemical structures of the impurities in the technical product of the plant growth regulator Atonic, the extracts of diethyl ether and dichloromethane were analyzed with GC-FID and GC-MSD. resulting in detection of five impurities and identification of their chemical structures. The amount of the active ingredient atonic in the technical product was about 84% and those of the impurities ranged from 0.24 to 10.74%. The identified impurities in this technical product are 2-methoxyphenol (guaiacol, m/z 124), 2-chloro-6-methoxyphenol and/or 4-chloro-6-methoxyphenol (m/z 158), 1,2-dimethoxy-4-nitrobenzene (m/z 183), and 2,6-bis(1,1-dimethylethyl)-4-methylphenol (m/z 220), suggesting that they are not hazardous impurities.

• Journal of the Korean Wood Science and Technology
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• v.48 no.3
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• pp.303-314
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• 2020

Gambir is a non-wood forest product with a potential of being used as wood adhesive, due to about 33% catechin in it. Meanwhile, catechins and sucrose have not been studied as adhesives. Therefore, basic characteristics of gambir-sucrose adhesives were investigated. In this research, adhesives were prepared by dissolving gambir and sucrose in distilled water, at different blending ratios of the gambir/sucrose such as 100/0, 75/25, 50/50, and 25/75 wt%. Furthermore, gas chromatography-mass spectrometry (GC-MS) was employed to determine the gambir chemical compositions, and Fourier transform-infrared (FTIR) spectroscopy was carried out to identify chemical bonds. Particleboards with a target density of 0.8 g/㎤ were then manufactured by hot-pressing for 10 min at 200℃. The internal bond (IB) strength of particleboard was subsequently measured. Based on the GC-MS analysis, 31.11% of catechin was identified. In addition, the viscosity, density, solid content, and gelation time of the adhesives, and insoluble matter content (IMC) in boiling water were 7.30~33.24 mPa.s, 1.2~1.3 g/㎤, 25.56~28.44%, 73~420 min, and 29.75~62.10%, respectively. Adding sucrose to the adhesive was observed to raise the IMC from 49.05 to 62.10%, at 180℃ and 200℃. FT-IR analysis showed that the gambir absorption peaks occurred at approximately 1620 cm^-1, assigned to the C=O stretching of 5-hydroxymethylfurfural, which tended to increase with the addition of sucrose. The reaction between gambir and sucrose was observed in the form of the dimethylene ether bridge. The 25/75 wt% gambir-sucrose adhesives and 200℃ hot-pressed temperature resulted in the highest IB strength (0.89 MPa), and met the requirement of JIS A5908-2003 type 18. Consequently, the gambir-sucrose adhesive could be used as a particleboard adhesive.

• Food Science of Animal Resources
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• v.25 no.4
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• pp.436-441
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• 2005

This experiment was conducted to study the effect of dried persimmon by-product on physico-chemical properties of chicken meat One hundred sixty broilers were fed diet for five weeks containing 0, 1, 3, and $5\%$ of dried persimmon by-product The pH was not significantly different between control and treatment groups. The shear force and cooking loss of the treatment groups were higher than the control group inn the water holing capacity (WHC) was higher in the control groups (P<0.05). The meat color of the treatments group showed redder than that of the control group owing to higher $a^*\;and\;b^*$ value. The flavor evaluated by sensory evaluation were improved by treatments group (P<0.05). In minerals, P content of the treatment groups were higher than that of the control group. The result of this experiment indicated that dried persimmon by-product tended to improve the flavor.