• Title/Summary/Keyword: supercritical water

Search Result 248, Processing Time 0.024 seconds

Antiallergic Effect of Two Variants of Artemisia princeps Pampanini

  • Shin, Yong-Wook;Bae, Eun-Ah;Lee, Bo-Mi;Min, Sung-Won;Lee, Jin-Hee;Baek, Nam-In;Ryu, Su-No;Chung, Hae-Gon;Kim, Nam-Jae;Kim, Dong-Hyun
    • Natural Product Sciences
    • /
    • v.12 no.2
    • /
    • pp.67-73
    • /
    • 2006
  • Antiallergic activities of two variants of Artemisia princeps Pampanini SJ-1 (named as Sajabalssuk) and SS-1 (named as Sajuarissuk) cultivated in Ganghwado, which contain high content of eupatilin compared to those cultured by other places, were investigated to evaluate the possibility as inhibitors against allergic diseases. Ethanol and supercritical fluid extracts of SJ-1 and SS-1 inhibited the release of ${\beta}-hexosaminidase$ from RBL-2H3 cells, although their water extracts were inactive. These extracts potently inhibited lipopolysaccharide-induced NO production of RAW264.7. However, these extracts almost did not scavenge free radicals. Oral administration of these extracts to mice inhibited passive cutaneous anaphylaxis reaction induced by IgE, and acute dermatitis induced by 12-O-tetradecanoylphorbol-13-acetate. However, these extracts did not inhibit chronic dermatitis. Scratching behaviors, vascular permeability, and writhing syndromes were weakly inhibited by these extract at a dose of 50 mg/kg. Based on these findings, we believe that SJ-1 and SS-1 can improve IgE-induced allergic diseases such as rhinitis and asthma.

Catalytic Gasification of Mandarin Waste Residue using Ni/CeO2-ZrO2

  • Kim, Seong-Soo;Kim, Jeong Wook;Park, Sung Hoon;Jung, Sang-Chul;Jeon, Jong-Ki;Ryu, Changkook;Park, Young-Kwon
    • Bulletin of the Korean Chemical Society
    • /
    • v.34 no.11
    • /
    • pp.3387-3390
    • /
    • 2013
  • Catalytic gasification of mandarin waste residue was carried out using direct and indirect catalyst-contact methods for the first time. In the indirect method, non-catalytic reaction in a reactor was followed by catalytic upgrading of vapor product in another reactor. Two different catalysts, $Ni/{\gamma}-Al_2O_3$ and $Ni/CeO_2-ZrO_2$, were employed. $CeO_2-ZrO_2$ support was prepared using hydrothermal synthesis in supercritical water. The catalysts were characterized by $H_2$-temperature programmed reduction and Brunauer-Emmett-Teller analyses. Under the condition of equivalent ratio (ER) = 0, the indirect catalyst-contact method led to a higher gas yield than the direct method. Under ER = 0.2, the yield of biogas obtained over $Ni/CeO_2-ZrO_2$ was higher than that obtained over $Ni/{\gamma}-Al_2O_3$. Also, the coke formation of $Ni/CeO_2-ZrO_2$ was lower than that of $Ni/{\gamma}-Al_2O_3$. Such results were attributed to the higher reducibility and better lattice oxygen mobility of $Ni/CeO_2-ZrO_2$, which were advantageous for partial oxidation reaction.

A Study on the Thermodynamic Analysis and the Computer Simulation for the $CO_2$ and $H_{2}S$ Capture Process Using Methanol as a Solvent (메탄올 용매를 이용한 이산화탄소와 황화수소 포집공정의 열역학적 해석 및 전산모사에 관한 연구)

  • Cho, Jung-Ho;Lee, Ji-Hwan
    • Clean Technology
    • /
    • v.14 no.4
    • /
    • pp.287-292
    • /
    • 2008
  • In this study, computer simulation works have been performed for the capture process of the $CO_2$ and $H_{2}S$ gases contained in the effluent stream using methanol aqueous solution. In order to increase the solubilities of the $CO_2$ and $H_{2}S$ in the methanol aqueous stream, the operating pressure of the absorber was raised to 30 bar and the feeding temperature of the solvent was lowered to $-20^{\circ}C$ by using refrigeration cycle. NRTL liquid activity coefficient model was used to estimate the liquid phase nonidealities for methanol and water. Soave-Redlich-Kwong equation of state was used for the vapor phase nonidealities. Henry's law option was also used to calculate the solubilities of the supercritical noncondensible gases into the methanol aqueous solvent stream.

  • PDF

Separation and Characteristics of Essential Oil from Dendropanax morbiferus (황칠나무 정유의 분리 및 특성)

  • Kim, Seung-Geon;Lee, Ho-Won
    • Applied Chemistry for Engineering
    • /
    • v.33 no.1
    • /
    • pp.44-49
    • /
    • 2022
  • Essential oil was separated from Dendropanax morbiferus (DM) by means of hot water extraction and supercritical extraction, respectively, and the separated essential oil was analyzed qualitatively and quantitatively, and the antioxidant effect of essential oil was investigated. In addition, yields of essential oil and Caryophyllene according to the drying and extraction methods for each part of DM were obtained and compared, respectively. The yield of essential oil was found to be high in the order of bark > leaves > twigs > limb. When the freeze-dried DM leaves were supercritically extracted, the yields of essential oil and Caryophyllene were 23.2 g/kg DM and 429.6 mg Caryophyllene/kg DM, respectively. The essential oil of DM showed an antioxidant effect even at a low concentration, and the concentration of the essential oil of SC50, which means 50% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, was about 0.34%.

Enhancing Carbon Dioxide Storage Efficiency in Aquifers through Surfactant Application (계면활성제 활용에 따른 공극 규모 이산화탄소 저장 효율 향상)

  • Gang, Seokgu;Jung, Jongwon
    • Journal of the Korean Geotechnical Society
    • /
    • v.39 no.11
    • /
    • pp.63-70
    • /
    • 2023
  • Underground carbon dioxide (CO2) storage emerges as a pivotal strategy for mitigating atmospheric CO2 emissions and addressing global warming concerns. This study investigates techniques to optimize storage efficiency in aquifers, which stand out for their superior capacity compared to other geological layers. The focus is on the application of nonionic and anionic surfactants to enhance CO2 storage efficiency within confined spaces. A specialized micromodel facilitating fluid flow observation was employed for the evaluation. Experimental results revealed a noteworthy minimum 40% increase in storage efficiency at the lowest injection rate when utilizing nonionic and anionic surfactants, in comparison to pure water injection. Interestingly, no significant variations in storage efficiency were observed based on the ionicity and concentration of the surfactants under investigation. These findings have implications for guiding the selection and concentration determination of surfactants in future underground CO2 storage endeavors.

Comparison of Volatile Compounds from Thymus Magnus Nakai by Three Different Extraction Methods (추출방법에 따른 섬백리향의 휘발성 향기성분 비교)

  • Lee, Sa Eun;Kim, Songmun;Lim, Won Churl;Kang, Ki Choon;Pyo, Hyeong Bae
    • Journal of the Society of Cosmetic Scientists of Korea
    • /
    • v.40 no.2
    • /
    • pp.171-178
    • /
    • 2014
  • The purpose of this study was to analyse the volatile components of Thymus magnus Nakai extracted by different extraction methods and reproduce scent close to original plant based on the results. For this purpose, the essential oil of T. magnus was extracted by supercritical fluid extraction (SFE), water and steam distillation (WSD) and simultaneous steam distillation and extraction (SDE) methods. The compositions of the essential oil were analyzed by gas chromatography-mass spectrometry (GC-MS). Consequently, linalool (0.1%) and trans-sabinene hydrate (0.9%) contents in the essential oil extracted by SFE method of $40^{\circ}C$ - 400 bar condition were relatively higher than compositions of the essential oil extracted by different conditions. The contents of borneol (3.82%), terpinen-4-ol (0.3%) and caryophyllene oxide (2.2%) were relatively higher at $50^{\circ}C$ - 400 bar and the contents of ${\beta}$-bisabolene (5.88%), 1-octen-3-ol (0.31%), caryophyllene (2.91%), p-cymene (2.04%) and ${\gamma}$-terpinene (0.52%) were extracted relatively higher at $50^{\circ}C$ - 300 bar. The compositions of the essential oil extracted by SFE method of $50^{\circ}C$ - 200 bar condition contained relatively higher contents of thymol (77.63%) and carvacrol (5.65%). The contents of ${\alpha}$-bisabolol (0.17%), caryophyllene (6.46%), cis-${\alpha}$-bisabolene (1.52%) and ${\beta}$-bisabolene (20.65%) in the essential oil extracted by WSD method were relatively higher than compositions of the essential oil extracted by SFE method, and by SDE method we couldn't obtained essential oil. The results of this study could be utilized to reproduce scent close to original scent of T. magnus.

The pH Reduction of the Recycled Aggregate Originated from the Waste Concrete by the scCO2 Treatment (초임계 이산화탄소를 이용한 폐콘크리트 순환골재의 중성화)

  • Chung, Chul-woo;Lee, Minhee;Kim, Seon-ok;Kim, Jihyun
    • Economic and Environmental Geology
    • /
    • v.50 no.4
    • /
    • pp.257-266
    • /
    • 2017
  • Batch experiments were performed to develop the method for the pH reduction of recycled aggregate by using $scCO_2$ (supercritical $CO_2$), maintaining the pH of extraction water below 9.8. Three different aggregate types from a domestic company were used for the $scCO_2$-water-recycled aggregate reaction to investigate the low pH maintenance of aggregate during the reaction. Thirty five gram of recycled aggregate sample was mixed with 70 mL of distilled water in a Teflon beaker, which was fixed in a high pressurized stainless steel cell (150 mL of capacity). The inside of the cell was pressurized to 100 bar and each cell was located in an oven at $50^{\circ}C$ for 50 days and the pH and ion concentrations of water in the cell were measured at a different reaction time interval. The XRD and SEM-EDS analyses for the aggregate before and after the reaction were performed to identify the mineralogical change during the reaction. The extraction experiment for the aggregate was also conducted to investigate the pH change of extracted water by the $scCO_2$ treatment. The pH of the recycled aggregate without the $scCO_2$ treatment maintained over 12, but its pH dramatically decreased to below 7 after 1 hour reaction and maintained below 8 for 50 day reaction. Concentration of $Ca^{2+}$, $Si^{4+}$, $Mg^{2+}$ and $Na^+$ increased in water due to the $scCO_2$-water-recycled aggregate reaction and lots of secondary precipitates such as calcite, amorphous silicate, and hydroxide minerals were found by XRD and SEM-EDS analyses. The pH of extracted water from the recycled aggregates without the $scCO_2$ treatment maintained over 12, but the pH of extracted water with the $scCO_2$ treatment kept below 9 of pH for both of 50 day and 1 day treatment, suggesting that the recycled aggregate with the $scCO_2$ treatment can be reused in real construction sites.

The Effect of Temperature on the Process of Immiscible Displacement in Pore Network (공극 구조 내 비혼성 대체 과정에서 주입 온도가 유체 거동에 미치는 영향)

  • Park, Gyuryeong;Kim, Seon-ok;Lee, Minhee;Wang, Sookyun
    • Economic and Environmental Geology
    • /
    • v.51 no.3
    • /
    • pp.223-232
    • /
    • 2018
  • The viscous force of fluids and the capillary force acting on the pore network of the porous media are important factors determining the immiscible displacement during geological $CO_2$ sequestration, these were directly affected by geological formation conditions and injection conditions. This study aimed to observe the migration and distribution of injected fluid and pore water, and quantitatively investigate displacement efficiency on various injection temperatures. This study aimed to perform micromodel experiments by applying n-hexane used as a proxy fluid for supercritical $CO_2$. In this study, immiscible displacement process from beginning of n-hexane injection to equilibrium of the distribution of the n-hexane and pore water was observed. The images from experiment were used to observe the displacement pattern and estimate the areal displacment efficiency of the n-hexane. For investigate the affects of the injection temperatures on the migration in macroscopic, migration of n-hexane in single pore was analyzed. The measurement revealed that the displacement efficiency at equilibrium state decreases as the temperature increases. The result from experiments indicate that the temperatures can affect the displacement pattern by changing the viscous forces and the capillary forces. The experimental results could provide important fundamental information on reservoir conditions and fluid injection conditions during geological $CO_2$ sequestration.

Removal of 5-hydroxymethylfurfural and Furfural in Sugar Hydrolysate by Wood Charcoal Treatment (목탄 처리에 의한 당화액 내 5-hydroxymethylfurfural 및 푸르푸랄 제거)

  • Jeong, Hanseob;Kim, Yong Sik;Lee, Jaejung;Chea, Kwang-Seok;Ahn, Byoung Jun;Lee, Soo Min
    • Journal of the Korean Wood Science and Technology
    • /
    • v.44 no.5
    • /
    • pp.705-715
    • /
    • 2016
  • The main aim of this study was to investigate the potential of wood charcoal on removing furan compounds (5-hydroxymethylfurfural (5-HMF), furfural) known as fermentation inhibitors in sugar hydrolysates obtained from supercritical water treatment of lignocellulosic biomass. For this aim, model hydrolysate was prepared, and removal rates of sugars or furan compounds depending on wood charcoal concentration and treatment time were calculated and analyzed in comparison with the case of activated carbon. 0.5, 1, 2, 4, 8, or 12% (w/v) of wood charcoal or activated carbon was loaded into the model hydrolysate, containing glucose, xylose, 5-HMF, and furfural, and treatment was conducted for 1, 3, 6, 12, or 24 h. After treatment, removal rates of 5-HMF and furfural gradually increased as wood charcoal concentration or treatment time increased, and over 95% of 5-HMF and furfural were removed at 8% of wood charcoal concentration and 3 h of treatment time, while the loss of sugars (< 2%) was hardly observed. On the other hand, in the case of activated carbon treatment, removal rates of 5-HMF and furfural were over 95% at mild condition (activated carbon concentration: 8%, treatment time: 1 h), but over 10% of glucose and xylose were removed. Therefore, considering sugar production and further process applied sugar, the wood charcoal treatment of sugar hydrolysate was more effective for removing furan compounds and maintaining the sugar yield.

Study of Optimized Extraction Conditions for Simultaneous Anti-inflammatory and Antioxidant Activity of Artemisia iwayomogi using Response Surface Methodology (반응표면분석을 이용한 한인진의 항염 및 항산화 복합 활성 최적 추출 조건에 관한 연구)

  • Park, Dawon;Choi, Woo Seok;Lee, Chang Hyeon
    • Journal of the Society of Cosmetic Scientists of Korea
    • /
    • v.45 no.3
    • /
    • pp.319-331
    • /
    • 2019
  • This study was conducted to find a solvent, a extraction method and optimized conditions for Artemisia iwayomogi extract. which is effective to anti-inflammatory and antioxidant activity. A. iwayomogi extract by distilled water, ethanol, methanol, hexane and ethyl acetate using ultrasonic, high-pressure and supercritical extraction was investigated for NO inhibitory and DPPH radical scavenging activity. Extract obtained by ethanol and ultrasonic extraction method showed high NO production inhibitory activity, DPPH free radical scavenging activity and yield. Response surface methodology (RSM) was applied to find a optimized ultrasonic extraction conditions. Results showed that the optimum conditions for the higher yield were ethanol solvent of 45.71% concentration with extraction time and ultrasonic power of 63.33min and 308.84 W, respectively. This condition predicted 15.85% yield, but real yield was $16.40{\pm}0.28%$. The optimum conditions for simultaneous anti-inflammatory and antioxidant activity were established as ethanol concentration (80.81%), extraction time (90.00 min) and ultrasonic power (400.00 W). NO production inhibitory and antioxidant activity were $89.77{\pm}1.37%$ and $60.12{\pm}0.39%$, respectively. These results showed similar to the predicted values of 94.54%, 58.03% respectively.