WorldWideScience

Sample records for competitive supercritical-co2 cycle

  1. Optimized, Competitive Supercritical-CO2 Cycle GFR for Gen IV Service

    Energy Technology Data Exchange (ETDEWEB)

    M.J. Driscoll; P. Hejzlar; G. Apostolakis

    2008-09-08

    An overall plant design was developed for a gas-cooled fast reactor employing a direct supercritical Brayton power conversion system. The most important findings were that (1) the concept could be capital-cost competitive, but startup fuel cycle costs are penalized by the low core power density, specified in large part to satisfy the goal of significatn post-accident passive natural convection cooling; (2) active decay heat removal is preferable as the first line of defense, with passive performance in a backup role; (3) an innovative tube-in-duct fuel assembly, vented to the primpary coolant, appears to be practicable; and (4) use of the S-Co2 GFR to support hydrogen production is a synergistic application, since sufficient energy can be recuperated from the product H2 and 02 to allow the electrolysis cell to run 250 C hotter than the reactor coolant, and the water boilers can be used for reactor decay heat removal. Increasing core poer density is identified as the top priority for future work on GFRs of this type.

  2. Scaling considerations for a multi-megawatt class supercritical CO2 brayton cycle and commercialization.

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, Darryn D.; Holschuh, Thomas Vernon,; Conboy, Thomas M.; Pasch, James Jay; Wright, Steven A; Rochau, Gary E; Fuller, Robert Lynn

    2013-11-01

    Small-scale supercritical CO2 demonstration loops are successful at identifying the important technical issues that one must face in order to scale up to larger power levels. The Sandia National Laboratories supercritical CO2 Brayton cycle test loops are identifying technical needs to scale the technology to commercial power levels such as 10 MWe. The small size of the Sandia 1 MWth loop has demonstration of the split flow loop efficiency and effectiveness of the Printed Circuit Heat Exchangers (PCHXs) leading to the design of a fully recuperated, split flow, supercritical CO2 Brayton cycle demonstration system. However, there were many problems that were encountered, such as high rotational speeds in the units. Additionally, the turbomachinery in the test loops need to identify issues concerning the bearings, seals, thermal boundaries, and motor controller problems in order to be proved a reliable power source in the 300 kWe range. Although these issues were anticipated in smaller demonstration units, commercially scaled hardware would eliminate these problems caused by high rotational speeds at small scale. The economic viability and development of the future scalable 10 MWe solely depends on the interest of DOE and private industry. The Intellectual Property collected by Sandia proves that the ~10 MWe supercritical CO2 power conversion loop to be very beneficial when coupled to a 20 MWth heat source (either solar, geothermal, fossil, or nuclear). This paper will identify a commercialization plan, as well as, a roadmap from the simple 1 MWth supercritical CO2 development loop to a power producing 10 MWe supercritical CO2 Brayton loop.

  3. Operation and analysis of a supercritical CO2 Brayton cycle.

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Steven Alan; Radel, Ross F.; Vernon, Milton E.; Pickard, Paul S.; Rochau, Gary Eugene

    2010-09-01

    Sandia National Laboratories is investigating advanced Brayton cycles using supercritical working fluids for use with solar, nuclear or fossil heat sources. The focus of this work has been on the supercritical CO{sub 2} cycle (S-CO2) which has the potential for high efficiency in the temperature range of interest for these heat sources, and is also very compact, with the potential for lower capital costs. The first step in the development of these advanced cycles was the construction of a small scale Brayton cycle loop, funded by the Laboratory Directed Research & Development program, to study the key issue of compression near the critical point of CO{sub 2}. This document outlines the design of the small scale loop, describes the major components, presents models of system performance, including losses, leakage, windage, compressor performance, and flow map predictions, and finally describes the experimental results that have been generated.

  4. Control system options and strategies for supercritical CO2 cycles.

    Energy Technology Data Exchange (ETDEWEB)

    Moisseytsev, A.; Kulesza, K. P.; Sienicki, J. J.; Nuclear Engineering Division; Oregon State Univ.

    2009-06-18

    The Supercritical Carbon Dioxide (S-CO{sub 2}) Brayton Cycle is a promising alternative to Rankine steam cycle and recuperated gas Brayton cycle energy converters for use with Sodium-Cooled Fast Reactors (SFRs), Lead-Cooled Fast Reactors (LFRs), as well as other advanced reactor concepts. The S-CO{sub 2} Brayton Cycle offers higher plant efficiencies than Rankine or recuperated gas Brayton cycles operating at the same liquid metal reactor core outlet temperatures as well as reduced costs or size of key components especially the turbomachinery. A new Plant Dynamics Computer Code has been developed at Argonne National Laboratory for simulation of a S-CO{sub 2} Brayton Cycle energy converter coupled to an autonomous load following liquid metal-cooled fast reactor. The Plant Dynamics code has been applied to investigate the effectiveness of a control strategy for the S-CO{sub 2} Brayton Cycle for the STAR-LM 181 MWe (400 MWt) Lead-Cooled Fast Reactor. The strategy, which involves a combination of control mechanisms, is found to be effective for controlling the S-CO{sub 2} Brayton Cycle over the complete operating range from 0 to 100 % load for a representative set of transient load changes. While the system dynamic analysis of control strategy performance for STARLM is carried out for a S-CO{sub 2} Brayton Cycle energy converter incorporating an axial flow turbine and compressors, investigations of the S-CO{sub 2} Brayton Cycle have identified benefits from the use of centrifugal compressors which offer a wider operating range, greater stability near the critical point, and potentially further cost reductions due to fewer stages than axial flow compressors. Models have been developed at Argonne for the conceptual design and performance analysis of centrifugal compressors for use in the SCO{sub 2} Brayton Cycle. Steady state calculations demonstrate the wider operating range of centrifugal compressors versus axial compressors installed in a S-CO{sub 2} Brayton Cycle as

  5. Review of supercritical CO2 power cycle technology and current status of research and development

    Directory of Open Access Journals (Sweden)

    Yoonhan Ahn

    2015-10-01

    Full Text Available The supercritical CO2 (S-CO2 Brayton cycle has recently been gaining a lot of attention for application to next generation nuclear reactors. The advantages of the S-CO2 cycle are high efficiency in the mild turbine inlet temperature region and a small physical footprint with a simple layout, compact turbomachinery, and heat exchangers. Several heat sources including nuclear, fossil fuel, waste heat, and renewable heat sources such as solar thermal or fuel cells are potential application areas of the S-CO2 cycle. In this paper, the current development progress of the S-CO2 cycle is introduced. Moreover, a quick comparison of various S-CO2 layouts is presented in terms of cycle performance.

  6. Supercritical CO2 Power Cycles: Design Considerations for Concentrating Solar Power

    Energy Technology Data Exchange (ETDEWEB)

    Neises, Ty; Turchi, Craig

    2014-09-01

    A comparison of three supercritical CO2 Brayton cycles: the simple cycle, recompression cycle and partial-cooling cycle indicates the partial-cooling cycle is favored for use in concentrating solar power (CSP) systems. Although it displays slightly lower cycle efficiency versus the recompression cycle, the partial-cooling cycle is estimated to have lower total recuperator size, as well as a lower maximum s-CO2 temperature in the high-temperature recuperator. Both of these effects reduce recuperator cost. Furthermore, the partial-cooling cycle provides a larger temperature differential across the turbine, which translates into a smaller, more cost-effective thermal energy storage system. The temperature drop across the turbine (and by extension, across a thermal storage system) for the partial-cooling cycle is estimated to be 23% to 35% larger compared to the recompression cycle of equal recuperator conductance between 5 and 15 MW/K. This reduces the size and cost of the thermal storage system. Simulations by NREL and Abengoa Solar indicate the partial-cooling cycle results in a lower LCOE compared with the recompression cycle, despite the former's slightly lower cycle efficiency. Advantages of the recompression cycle include higher thermal efficiency and potential for a smaller precooler. The overall impact favors the use of a partial-cooling cycle for CSP compared to the more commonly analyzed recompression cycle.

  7. Potential Improvements of Supercritical CO2 Brayton Cycle by Modifying Critical Point of CO2

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Woo Seok; Lee, Jeong Ik; Jeong, Yong Hoon; No, Hee Cheon [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2009-10-15

    A Sodium-cooled Fast Reactor (SFR) is one of strong candidates for a next generation nuclear reactor. However, the conventional design of a SFR concept with an indirect Rankine cycle is subjected to a sodium water reaction, which can deteriorate the safety of a SFR. To prevent any hazards from sodium-water reaction, a SFR with the Brayton cycle using Helium or Supercritical Carbon dioxide (S-CO2) as working fluids can be an alternative approach to improve the current SFR design. As in a helium cycle, there has been an investigation to modify thermo-physical properties to increase the efficiency of the cycle and reduce the size of turbomachineries. Particularly, He-Xe or He-N2 binary mixture were successful to decrease the stages of turbomachines due to the increment of molecular weight of gas mixture than that of pure helium. Similar to the case of helium, CO2 has a potential to modify its thermo-physical properties by mixing with other gases. For instance, it was reported that critical point of CO2 can be shifted by mixing with different gases. Since, the efficiency of a S-CO2 cycle is limited to the critical point of CO2, the shift in critical point implies that there is a possibility of improving the cycle efficiency than the current design. This paper presents the results of a preliminary analysis to identify the effects of CO2 critical point modification on the Brayton cycle performance.

  8. Performance of a Supercritical CO2 Bottoming Cycle for Aero Applications

    National Research Council Canada - National Science Library

    Florian Jacob; Andrew Martin Rolt; Joshua Marius Sebastiampillai; Vishal Sethi; Mathieu Belmonte; Pedro Cobas

    2017-01-01

    .... This could provide additional shaft power. Supercritical carbon dioxide closed-circuit power cycles are currently being investigated primarily for stationary power applications, but their high power density and efficiency, even for modest...

  9. Supercritical CO2 direct cycle Gas Fast Reactor (SC-GFR) concept.

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Steven Alan; Parma, Edward J., Jr.; Suo-Anttila, Ahti Jorma (Computational Engineering Analysis, Albuquerque, NM); Al Rashdan, Ahmad (Texas A& M University, College Station, TX); Tsvetkov, Pavel Valeryevich (Texas A& M University, College Station, TX); Vernon, Milton E.; Fleming, Darryn D.; Rochau, Gary Eugene

    2011-05-01

    This report describes the supercritical carbon dioxide (S-CO{sub 2}) direct cycle gas fast reactor (SC-GFR) concept. The SC-GFR reactor concept was developed to determine the feasibility of a right size reactor (RSR) type concept using S-CO{sub 2} as the working fluid in a direct cycle fast reactor. Scoping analyses were performed for a 200 to 400 MWth reactor and an S-CO{sub 2} Brayton cycle. Although a significant amount of work is still required, this type of reactor concept maintains some potentially significant advantages over ideal gas-cooled systems and liquid metal-cooled systems. The analyses presented in this report show that a relatively small long-life reactor core could be developed that maintains decay heat removal by natural circulation. The concept is based largely on the Advanced Gas Reactor (AGR) commercial power plants operated in the United Kingdom and other GFR concepts.

  10. Modeling and experimental results for condensing supercritical CO2 power cycles.

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Steven Alan; Conboy, Thomas M.; Radel, Ross F.; Rochau, Gary Eugene

    2011-01-01

    This Sandia supported research project evaluated the potential improvement that 'condensing' supercritical carbon dioxide (S-CO{sub 2}) power cycles can have on the efficiency of Light Water Reactors (LWR). The analytical portion of research project identified that a S-CO{sub 2} 'condensing' re-compression power cycle with multiple stages of reheat can increase LWR power conversion efficiency from 33-34% to 37-39%. The experimental portion of the project used Sandia's S-CO{sub 2} research loop to show that the as designed radial compressor could 'pump' liquid CO{sub 2} and that the gas-cooler's could 'condense' CO{sub 2} even though both of these S-CO{sub 2} components were designed to operate on vapor phase S-CO{sub 2} near the critical point. There is potentially very high value to this research as it opens the possibility of increasing LWR power cycle efficiency, above the 33-34% range, while lowering the capital cost of the power plant because of the small size of the S-CO{sub 2} power system. In addition it provides a way to incrementally build advanced LWRs that are optimally designed to couple to S-CO{sub 2} power conversion systems to increase the power cycle efficiency to near 40%.

  11. Compressor Modeling for Transient Analysis of Supercritical CO2 Brayton Cycle by using MARS code

    Energy Technology Data Exchange (ETDEWEB)

    Park, Joo Hyun; Park, Hyun Sun; Kim, Tae Ho; Kwon, Jin Gyu [POSTECH, Pohang (Korea, Republic of); Bae, Sung Won; Cha, Jae Eun [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    In this study, SCIEL (Supercritical CO{sub 2} Integral Experimental Loop) was chosen as a reference loop and the MARS code was as the transient cycle analysis code. As a result, the compressor homologous curve was developed from the SCIEL experimental data and MARS analysis was performed and presented in the paper. The advantages attract SCO{sub 2}BC as a promising next generation power cycles. The high thermal efficiency comes from the operation of compressor near the critical point where the properties of SCO{sub 2}. The approaches to those of liquid phase, leading drastically lower the compression work loss. However, the advantage requires precise and smooth operation of the cycle near the critical point. However, it is one of the key technical challenges. The experimental data was steady state at compressor rotating speed of 25,000 rpm. The time, 3133 second, was starting point of steady state. Numerical solutions were well matched with the experimental data. The mass flow rate from the MARS analysis of approximately 0.7 kg/s was close to the experimental result of 0.9 kg/s. It is expected that the difference come from the measurement error in the experiment. In this study, the compressor model was developed and implemented in MARS to study the transient analysis of SCO{sub 2}BC in SCIEL. We obtained the homologous curves for the SCIEL compressor using experimental data and performed nodalization of the compressor model using MARS code. In conclusions, it was found that numerical solutions from the MARS model were well matched with experimental data.

  12. Pore-scale Evolution of Supercritical CO2 within Bentheimer Sandstone during Multiple Drainage-Imbibition Cycles

    Science.gov (United States)

    Herring, A. L.; Andersson, L.; Wildenschild, D.

    2014-12-01

    Geologic CO2 sequestration has been proposed as a climate change mitigation strategy to limit emissions of CO2 to the atmosphere from large fossil-fuel burning CO2 point sources; however, there are concerns associated with the long-term stability of a mobile subsurface CO2 plume. The large-scale movement of subsurface supercritical CO2 (scCO2) can be prevented via capillary trapping, wherein scCO2 is immobilized in the subsurface by capillary interactions between the solid surface, resident brine, and scCO2. Capillary trapping occurs in two steps: first, the porous medium undergoes drainage as scCO2 is injected into the system; then, wetting fluid re-enters the medium in an imbibition process, isolating small bubbles of scCO2 in the pore bodies of the medium. There are many empirical models which predict capillary trapping for a single drainage-imbibition cycle; however, in an engineered CO2 sequestration project, it is possible to implement cyclic scCO2-water injections in a water-alternating-gas (WAG) injection scheme in which the system may undergo multiple CO2 injections to potentially increase the trapping efficiency of scCO2. We present experimental results of multiple drainage-imbibition cycles of scCO2 and 1:6 by mass potassium iodide (KI) brine within Bentheimer sandstone. Capillary (differential) pressure and absolute pressures for each phase were continuously measured throughout each flow process, which is a unique feature of our experimental system. Experiments were conducted at a working pressure of 8.3 MPa (1200 PSI) and 40oC, and synchrotron x-ray computed microtomography (x-ray CMT) images were collected of the drainage and imbibition process endpoints at a resolution of 3.19 μm at the Advanced Photon Source at Argonne National Laboratory. The evolution of the connectivity, topology, morphology, and capillary trapping of scCO2 phase is analyzed as a function of capillary pressure, scCO2 saturation, and sample history. Preliminary results suggest

  13. Thermodynamic optimisation of supercritical CO2 Brayton power cycles coupled to Direct Steam Generation Line-Focusing solar fields

    OpenAIRE

    Coco Enriquez, Luis; Muñoz Antón, Javier; Martínez-Val Peñalosa, Jose Maria

    2016-01-01

    In this paper a new generation line-focusing solar plants coupled to a s-CO2 Brayton power cycles are studied. These innovative CSP will increase the plant energy efficiency, and subsequently optimizing the SF effective aperture area and SF investment cost for a fixed power output. Two SF configurations were assessed: the Configuration 1 with a condenser between the SF and the Balance Of Plant (BOP), for Turbine Inlet Temperatures (TIT) up to 400oC, and the Configuration 2, for higher TIT up ...

  14. Pore-scale Simulations of Capillary Trapping of Supercritical CO2 after Multiple Drainage and Imbibition Cycles

    Science.gov (United States)

    Schaap, M. G.

    2015-12-01

    Carbon capture and storage (CCS) of carbon dioxide emissions generated by production or combustion of fossil fuels is a technologically viable means to reduce the build-up of CO2 in the atmosphere and oceans. On a fundamental level, capillary trapping of scCO2 is a pore-scale process that shares mechanisms that are relevant, for example in oil recovery and remediation of NAPL-contaminated aquifers. Capillary trapping of scCO2 differs rather significantly from trapping of oil recovery and NAPL remediation in that the goal is to maximize the amount of NWP storage, whereas the objective of the other applications is to minimize the amount of residual NWP. This difference makes research into capillary trapping of scCO2 unique, but also complex because scCO2 phase properties (e.g. viscosity, density, and interfacial tension) exhibit large shifts with pressure and temperature which can strongly alter the trapping potential and efficiency. In this presentation we compare direct pore-scale observations of the Brine-CO2 drainage and imbibition process with lattice Boltzmann model simulations. The observations were conducted with the synchrotron-based x-ray microtomography facility at the Advanced Photon Source (APS) at Argonne National Laboratory using a novel x-ray compatible, high-pressure, elevated temperature setup. The "large" volumes (~1200 mm3; 6.3 mm diameter and 40 mm in length) were segmented into solid phase (Bentheimer Sandstone), Brine (KI, 1140 kg/m3) and scCO2. We will present LB simulations of small (64^3 voxels) and large sections of the scanned cores with a simple Shan-Chen-type model and a more advanced Equation of State-type model and compare model results to pressure and CO2 saturation levels that were observed for the CO2 invasion and Brine re-imbibition process. We will present results for the smaller sections under multiple drainage and imbibition cycles to investigate whether this will lead to enhanced trapping of scCO2 as found in earlier research.

  15. Supercritical CO2 Extraction of Ethanol

    OpenAIRE

    GÜVENÇ, A.; MEHMETOĞLU, Ü.; ÇALIMLI, A.

    1999-01-01

    Extraction of ethanol was studied from both synthetic ethanol solution and fermentation broth using supercritical CO2 in an extraction apparatus in ranges of 313 to 333 K and 80 to 160 atmospheres, for varying extraction times. The experimental system consists mainly of four parts: a CO2 storage system, a high-pressure liquid pump, an extractor and a product collection unit. Samples were analyzed by gas chromatography. Effects of temperature, pressure, extraction time, initial ethan...

  16. 10 MW Supercritical CO2 Turbine Test

    Energy Technology Data Exchange (ETDEWEB)

    Turchi, Craig

    2014-01-29

    The Supercritical CO2 Turbine Test project was to demonstrate the inherent efficiencies of a supercritical carbon dioxide (s-CO2) power turbine and associated turbomachinery under conditions and at a scale relevant to commercial concentrating solar power (CSP) projects, thereby accelerating the commercial deployment of this new power generation technology. The project involved eight partnering organizations: NREL, Sandia National Laboratories, Echogen Power Systems, Abengoa Solar, University of Wisconsin at Madison, Electric Power Research Institute, Barber-Nichols, and the CSP Program of the U.S. Department of Energy. The multi-year project planned to design, fabricate, and validate an s-CO2 power turbine of nominally 10 MWe that is capable of operation at up to 700°C and operates in a dry-cooled test loop. The project plan consisted of three phases: (1) system design and modeling, (2) fabrication, and (3) testing. The major accomplishments of Phase 1 included: Design of a multistage, axial-flow, s-CO2 power turbine; Design modifications to an existing turbocompressor to provide s-CO2 flow for the test system; Updated equipment and installation costs for the turbomachinery and associated support infrastructure; Development of simulation tools for the test loop itself and for more efficient cycle designs that are of greater commercial interest; Simulation of s-CO2 power cycle integration into molten-nitrate-salt CSP systems indicating a cost benefit of up to 8% in levelized cost of energy; Identification of recuperator cost as a key economic parameter; Corrosion data for multiple alloys at temperatures up to 650ºC in high-pressure CO2 and recommendations for materials-of-construction; and Revised test plan and preliminary operating conditions based on the ongoing tests of related equipment. Phase 1 established that the cost of the facility needed to test the power turbine at its full power and temperature would exceed the planned funding for Phases 2 and 3. Late

  17. Towards Overhauser DNP in supercritical CO2

    Science.gov (United States)

    van Meerten, S. G. J.; Tayler, M. C. D.; Kentgens, A. P. M.; van Bentum, P. J. M.

    2016-06-01

    Overhauser Dynamic Nuclear Polarization (ODNP) is a well known technique to improve NMR sensitivity in the liquid state, where the large polarization of an electron spin is transferred to a nucleus of interest by cross-relaxation. The efficiency of the Overhauser mechanism for dipolar interactions depends critically on fast local translational dynamics at the timescale of the inverse electron Larmor frequency. The maximum polarization enhancement that can be achieved for 1H at high magnetic fields benefits from a low viscosity solvent. In this paper we investigate the option to use supercritical CO2 as a solvent for Overhauser DNP. We have investigated the diffusion constants and longitudinal nuclear relaxation rates of toluene in high pressure CO2. The change in 1H T1 by addition of TEMPO radical was analyzed to determine the Overhauser cross-relaxation in such a mixture, and is compared with calculations based on the Force Free Hard Sphere (FFHS) model. By analyzing the relaxation data within this model we find translational correlation times in the range of 2-4 ps, depending on temperature, pressure and toluene concentration. Such short correlation times may be instrumental for future Overhauser DNP applications at high magnetic fields, as are commonly used in NMR. Preliminary DNP experiments have been performed at 3.4 T on high pressure superheated water and model systems such as toluene in high pressure CO2.

  18. Towards Overhauser DNP in supercritical CO2.

    Science.gov (United States)

    van Meerten, S G J; Tayler, M C D; Kentgens, A P M; van Bentum, P J M

    2016-06-01

    Overhauser Dynamic Nuclear Polarization (ODNP) is a well known technique to improve NMR sensitivity in the liquid state, where the large polarization of an electron spin is transferred to a nucleus of interest by cross-relaxation. The efficiency of the Overhauser mechanism for dipolar interactions depends critically on fast local translational dynamics at the timescale of the inverse electron Larmor frequency. The maximum polarization enhancement that can be achieved for (1)H at high magnetic fields benefits from a low viscosity solvent. In this paper we investigate the option to use supercritical CO2 as a solvent for Overhauser DNP. We have investigated the diffusion constants and longitudinal nuclear relaxation rates of toluene in high pressure CO2. The change in (1)H T1 by addition of TEMPO radical was analyzed to determine the Overhauser cross-relaxation in such a mixture, and is compared with calculations based on the Force Free Hard Sphere (FFHS) model. By analyzing the relaxation data within this model we find translational correlation times in the range of 2-4ps, depending on temperature, pressure and toluene concentration. Such short correlation times may be instrumental for future Overhauser DNP applications at high magnetic fields, as are commonly used in NMR. Preliminary DNP experiments have been performed at 3.4T on high pressure superheated water and model systems such as toluene in high pressure CO2.

  19. Plasticisation and complexation of certain polymers in supercritical CO2

    CSIR Research Space (South Africa)

    Labuschagne, Philip W

    2004-09-01

    Full Text Available A polymer system (polyvinylpyrrolidone + polyvinyl acetate-co-crotonic acid) was successfully identified for use as encapsulation material for sensitive actives using supercritical CO2 as plasticisation medium, having the following properties: 1...

  20. Isolation of Organochlorine Pesticide from Ginseng with Supercritical CO2

    Institute of Scientific and Technical Information of China (English)

    李淑芬; 王幼君; 全灿; 田松江

    2005-01-01

    The feasibility of removal of the organochlorine pesticides residues of hexachlorocyclohexane(BHC) from radix ginseng with supercritical CO2 was explored. Some factors, such as extraction pressure, extraction temperature, and kinds of co-solvents were investigated. The experimental results indicate that it is possible to reduce BHC residues in radix ginseng to the level of 0.1 × 10-6 with supercritical CO2 in the presence of suitable amount of co-solvent, such as water.

  1. SOLID PHASE TRANSITION OF SYNDIOTACTIC POLYSTYRENE IN SUPERCRITICAL CO2

    Institute of Scientific and Technical Information of China (English)

    Yu-ying Li; Jia-song He

    2002-01-01

    Solid phase transition of the a form crystals to the β form crystals in syndiotactic polystyrene (sPS) samples has occurred in supercritical CO2. This transformation is different from those detected under other conditions. The effects of some factors (e.g. time, temperature, and pressure) on the solid phase transformation of sPS in supercritical CO2 were analyzed in detail. Experimental results show that longer time, higher temperature or higher pressure favors the transformation of the α form crystals to the β form crystals.

  2. [Chemical constituents from supercritical CO2 extraction of Schisandra chinensis].

    Science.gov (United States)

    Zhu, Hong-yan; Lin, Hai-cheng; Wang, Guo-li; Zhang, Lian-xue

    2014-11-01

    To study the chemical constituents from the supercritical CO2 extraction of Schisandra chinensis. The compounds were separated and purified by conventional column chromatography and their structures were identified by spectroscopic methods. Nine compounds were isolated from the supercritical CO2 extraction of Schisandra chinensis, and their structures were identified as chrysophanol(1),schisandrin B(2), β-sitosterol(3), schisandrin C(4),schisandrol A(5), angeloylgomisin H(6), daucosterol(7) 1, 5-dimethyl citrate (8), and shikimic acid (9). Compounds 1, 8 and 9 are isolated from Schisandra chinensis for the first time,and compound 1 as an anthraquinone is isolated from this genus for the first time.

  3. Design of an efficient space constrained diffuser for supercritical CO2 turbines

    Science.gov (United States)

    Keep, Joshua A.; Head, Adam J.; Jahn, Ingo H.

    2017-03-01

    Radial inflow turbines are an arguably relevant architecture for energy extraction from ORC and supercritical CO 2 power cycles. At small scale, design constraints can prescribe high exit velocities for such turbines, which lead to high kinetic energy in the turbine exhaust stream. The inclusion of a suitable diffuser in a radial turbine system allows some exhaust kinetic energy to be recovered as static pressure, thereby ensuring efficient operation of the overall turbine system. In supercritical CO 2 Brayton cycles, the high turbine inlet pressure can lead to a sealing challenge if the rotor is supported from the rotor rear side, due to the seal operating at rotor inlet pressure. An alternative to this is a cantilevered layout with the rotor exit facing the bearing system. While such a layout is attractive for the sealing system, it limits the axial space claim of any diffuser. Previous studies into conical diffuser geometries for supercritical CO 2 have shown that in order to achieve optimal static pressure recovery, longer geometries of a shallower cone angle are necessitated when compared to air. A diffuser with a combined annular-radial arrangement is investigated as a means to package the aforementioned geometric characteristics into a limited space claim for a 100kW radial inflow turbine. Simulation results show that a diffuser of this design can attain static pressure rise coefficients greater than 0.88. This confirms that annular-radial diffusers are a viable design solution for supercritical CO2 radial inflow turbines, thus enabling an alternative cantilevered rotor layout.

  4. Preparation of PMMA Foam by Supercritical CO2 with Ethanol

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Supercritical CO2 with ethanol as blowing agent foamed poly(methylmethacrylate) (PMMA) fiber at 308.15K and in the pressure range from 12-15MPa. The foam structure was detected using scanning electron microscope. It was found that the concentration of ethanol in the fluid is a major parameter to affect the foam structure.

  5. Supercritical CO2 impregnation of polyethylene components for medical purposes

    Directory of Open Access Journals (Sweden)

    Gamse Thomas

    2007-01-01

    Full Text Available Modem hip and knee endoprosthesis are produced in titanium and to reduce the friction at the contact area polymer parts, mainly ultra-high molecular weight polyethylene (UHMW-PE, are installed. The polyethylene is impregnated with a-tocopherol (vitamin E before processing for remarkable decrease of oxidative degradation. Cross linked UHMW-PE offers much higher stability, but a-tocopherol cannot be added before processing, because a-tocopherol hinders the cross linking process accompanied by a heavy degradation of the vitamin. The impregnation of UHMW-PE with a-tocopherol has to be performed after the cross linking process and an accurate concentration has to be achieved over the cross section of the whole material. In the first tests UHMW-PE-cubes were stored in pure a-tocopherol under inert atmosphere at temperatures from 100 to 150 °C resulting in a high mass fraction of a-tocopherol in the edge zones and no constant concentration over the cross section. For better distribution and for regulating the mass fraction of a-tocopherol in the cross linked UHMW-PE material supercritical CO2 impregnation tests were investigated. Again UHMW-PE-cubes were impregnated in an autoclave with a-tocopherol dissolved in supercritical CO2 at different pressures and temperatures with variable impregnation times and vitamin E concentrations. Based on the excellent results of supercritical CO2 impregnation standard hip and knee cups were stabilized nearly homogeneously with varying mass fraction of a-tocopherol.

  6. Supercritical CO2 extraction of essential oils from Thymus vulgaris

    Directory of Open Access Journals (Sweden)

    S.A.B. Vieira de Melo

    2000-09-01

    Full Text Available Supercritical CO2 extraction of essential oil from Thymus vulgaris leaves was studied using experimental data recently obtained in the Florys S.p.A. laboratory. Mass transfer coefficients in the supercritical and solid phases from extraction curves at 40°C and 20 MPa were evaluated using a mathematical model based on the local adsorption equilibrium of essential oil on lipid in leaves. The adsorption equilibrium constant was fitted to these experimental data, and internal and external mass transfer resistances were calculated, allowing identification of the mechanism controlling the extraction process.

  7. Asymmetric Synthesis Using Enzymes in Supercritical CO2

    Institute of Scientific and Technical Information of China (English)

    T. Matsuda

    2005-01-01

    @@ 1Introduction Great efforts have been extended to catalysis in supercritical CO2 (scCO2) since the early 1990's due to the environmental friendliness, high diffusivity, high solubilizing power, easiness of the product separation,etc.. A combined process of scCO2 and enzymatic catalyst system would be a promising synthetic tool to produce optically active compounds because the enzyme has advantages of being natural and having high enantioselectivity in nature. Here we report asymmetric synthesis using lipase and alcohol dehydrogenase in scCO2[1,2].

  8. Hazelnut oil production using pressing and supercritical CO2 extraction

    Directory of Open Access Journals (Sweden)

    Jokić Stela

    2016-01-01

    Full Text Available In the hazelnut oil production it is very important to find an appropriate method to recover the oil from kernels. The objective of this study was to evaluate the oil extraction process from hazelnuts by screw pressing followed by extraction with supercritical CO2. The effects of temperature head presses, frequency and nozzle size in pressing experiments on oil temperature and recovery were monitored. The optimal pressing condition using response surface methodology was determined. In obtained hazelnut oil the following quality parameters were determined: peroxide value 0 mmol O2/kg, free fatty acids 0.23%, insoluble impurities 0.42%, moisture content 0.045%, iodine value 91.55 g I2/100 g, saponification value 191.46 mg KOH/g and p-anisidine value 0.19. Rosemary extract was the most effective in protecting the oil from oxidative deterioration. The residual oil that remained in the cake after pressing was extracted totally with supercritical CO2 and such defatted cake, free of toxic solvents, can be used further in other processes.

  9. [Effect of entrainer on supercritical CO2 for extraction of tradition and herbal drugs].

    Science.gov (United States)

    Xi, Yanbin; Xia, Xiaohui; Jin, Ran; Zhang, Yu; Yang, Liqin; Tang, Shihuan

    2009-06-01

    Type, mode of affiliating, mechanism of action of entrainer in Supercritical CO2 on extraction of Chinese traditional and herbal drugs were briefly reviewed. Application of entrainer in Supercritical CO2 on extraction of flavones, terpenes, sterols, and saponins in Chinese traditional and herbal drugs were recommended in particular. Some problems and directions in research of entrainer in Supercritical CO2 on extraction of Chinese traditional and herbal drugs were shown in this paper.

  10. [Extraction of lobetyolin from codonopsis with supercritical CO2].

    Science.gov (United States)

    Liu, Tongju; Li, Shufen; Min, Jiang; Bao, Xiaomei

    2009-03-01

    To develop a green and rapid method for extraction of lobetyolin from C. pilosula. Extraction of lobetyolin from C. pilosula with supercritical carbon dioxide in the presence of ethanol was studied. The effects of pressure, temperature, volume of cosolvent and extraction time on efficiency and their interactive relationships were discussed, based on central composite design and response surface methodology (RSM). The key effect factor was volume of cosolvent. The extraction yield of lobetyolin was 0.078 6 mg x g(-1) when C. pilosula (40-60 mesh) was extracted at 30 MPa, 60 degrees C and 2 L x min(-1) (as CO2 in normal pressure and temperature) for 100 minutes with supercritical CO2 and 1 mL x min(-1) ethanol as dynamic cosolvent. This result is better than that obtained from traditional method. Therefore, the optimized process is valuable for extraction of lobetyolin from C. pilosula.

  11. Oxidation of Styrene with Molecular Oxygen in Supercritical CO2

    Institute of Scientific and Technical Information of China (English)

    Tao JIANG; Bu Xing HAN; Guo Ying ZHAO; Zhong Hao LI; Yan Hong CHANG; Hai Xiang GAO; Jun Chun LI

    2004-01-01

    The oxidation of styrene with molecular oxygen catalyzed by PdCl2+CuCl2 has been investigated in supercritical CO2 with a batch reactor. The oxidative system of styrene contains four components at the beginning and seven components during the reaction. The critical temperature, critical pressure, and critical density at different conversions are determined by using a high-pressure view cell. The effect of phase behavior on the conversion and selectivity were studied. Experimental results showed that the critical parameters of the reaction mixture at fixed initial molar ratio changed with the conversion of reactant. The conversion of styrene reached maximum near the critical density of the reaction mixture. Product selectivity also varied with density of reaction mixture and could be tuned to some degree.

  12. Supercritical CO2 assisted process for the production of high-purity and sterile nano-hydroxyapatite/chitosan hybrid scaffolds.

    Science.gov (United States)

    Ruphuy, G; Souto-Lopes, M; Paiva, D; Costa, P; Rodrigues, A E; Monteiro, F J; Salgado, C L; Fernandes, M H; Lopes, J C; Dias, M M; Barreiro, M F

    2017-05-04

    Hybrid scaffolds composed of hydroxyapatite (HAp), in particular in its nanometric form (n-HAp), and chitosan (CS) are promising materials for non-load-bearing bone graft applications. The main constraints of their production concern the successful implementation of the final purification/neutralization and sterilization steps. Often, the used purification strategies can compromise scaffold structural features, and conventional sterilization techniques can result in material's thermal degradation and/or contamination with toxic residues. In this context, this work presents a process to produce n-HAp/CS scaffolds mimicking bone composition and structure, where an innovative single step based on supercritical CO2 extraction was used for both purification and sterilization. A removal of 80% of the residual acetic acid was obtained (T = 75°C, p = 8.0 MPa, 2 extraction cycles of 2 h) giving rise to scaffolds exhibiting adequate interconnected porous structure, fast swelling and storage modulus compatible with non-load-bearing applications. Moreover, the obtained scaffolds showed cytocompatibility and osteoconductivity without further need of disinfection/sterilization procedures. Among the main advantages, the proposed process comprises only three steps (n-HAp/CS dispersion preparation; freeze-drying; and supercritical CO2 extraction), and the supercritical CO2 extraction show clear advantages over currently used procedures based on neutralization steps. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017. © 2017 Wiley Periodicals, Inc.

  13. MALEIC ANHYDRIDE HYDROGENATION OF PD/AL2O3 CATALYST UNDER SUPERCRITICAL CO2 MEDIUM

    Science.gov (United States)

    Hydrogenation of maleic anhydride (MA) to either y-butyrolactone of succinic anhydride over simple Pd/Al2O3 impregnated catalyst in supercritical CO2 medium has been studied at different temperatures and pressures. A comparison of the supercritical CO2 medium reaction with the c...

  14. Adsorption of ethyl acetate onto modified clays and its regeneration with supercritical CO2

    Directory of Open Access Journals (Sweden)

    A. M. Cavalcante

    2005-03-01

    Full Text Available Modified clays were used to remove ethyl acetate from aqueous solutions. These clays were regenerated using supercritical CO2. Structural changes in the montmorillonite clay after treatment with quaternary amines were studied. The surface properties of the modified clay changed from highly hydrophilic to highly organophilic. The clay was regenerated by percolation of a stream of CO2 through the porous montmorillonite matrix. Different pressures and temperatures were employed, resulting in different fluid conditions (gas, liquid, and supercritical. The experimental data was fitted with a simplified model. The best desorption result was found under supercritical conditions. A crossover effect was observed. The capacity of the modified clay as a pollutant attenuator remained almost unchanged after a regeneration cycle.

  15. Comparision of conventional and supercritical CO2-extracted rosehip oil

    Directory of Open Access Journals (Sweden)

    J.M. del Valle

    2000-09-01

    Full Text Available Supercritical CO2 (SCO2 can be utilized to extract oils from a number of plant materials as a nontoxic alternative to hexane, and there is industrial interest in using SCO2 extraction to obtain high-quality oils for cosmetics and other high-value applications. A possible substrate is rosehip (Rosa aff. rubiginosa seed. The scope of our work was to select SCO2 extraction conditions and to compare cold-pressed, hexane-extracted and SCO2-extracted rosehip oil. We used a fractional factorial experimental design with extraction temperature (T, 40-60 °C, extraction pressure (p, 300-500 bar and dynamic extraction time (t, 90-270 min as independent variables and yield and color as response variables. Samples of 100 g flaked rosehip seeds were extracted with 21 g CO2/min, following a static extraction (15 min adjustment period. Resulting data were analyzed using response surface methodology. Extracted oil (4.7-7.1% in our experimental region increased slightly with p and more pronouncedly with T and specially t. On the other hand, the photometric color index was independent of t but worsened (increased as a result of an increase in either p or specially T. We extracted five batches of 250 g seeds with 21 g CO2/min at 40 °C and 300 bar for 270 min and compared the oil with samples obtained by solvent extraction (a batch of 2.5 kg of laminated seeds was treated with 10 L hexane and rotaevaporated until there was virtually no residual hexane and cold pressing, by determining color, fatty acid composition, iodine index and saponification index. It was concluded that SCO2 allows an almost complete recovery of rosehip oil (6.5% yield, which is of a better quality than the oil extracted with hexane. Yield was higher than it was when using a cold-pressing process (5.0% yield.

  16. [Optimization for supercritical CO2 extraction with response surface methodology of Prunus armeniaca oil].

    Science.gov (United States)

    Chen, Fei-Fei; Wu, Yan; Ge, Fa-Huan

    2012-03-01

    To optimize the extraction conditions of Prunus armeniaca oil by Supercritical CO2 extraction and identify its components by GC-MS. Optimized of SFE-CO extraction by response surface methodology and used GC-MS to analysis Prunus armeniaca oil compounds. Established the model of an equation for the extraction rate of Prunus armeniaca oil by supercritical CO2 extraction, and the optimal parameters for the supercritical CO2 extraction determined by the equation were: the extraction pressure was 27 MPa, temperature was 39 degrees C, the extraction rate of Prunus armeniaca oil was 44.5%. 16 main compounds of Prunus armeniaca oil extracted by supercritical CO2 were identified by GC-MS, unsaturated fatty acids were 92.6%. This process is simple, and can be used for the extraction of Prunus armeniaca oil.

  17. Molecular dynamics simulation of the key characteristics of the supercritical CO2-pentaerythritol tetraacetate system

    Science.gov (United States)

    Lei, Peiyu; Jin, Zunlong; Liu, Hong; Wang, Dingbiao; Liu, Donglai

    2016-12-01

    Supercritical CO2 is widely used in many fields of industry. Investigation of statistical mechanics of CO2 fluid under quasi critical and supercritical state has great significance. Equilibrium molecular dynamics (EMD) simulations are carried out to investigate the statistical mechanics and macroscopic performance of CO2 fluid under the quasi critical and supercritical state. The results show that the bond length and bond angle distributions for supercritical CO2 are Gaussian distribution basically. The dimers' proportion of supercritical CO2 system changes with pressure increasing. T-type dimer has high share within the system when pressure is higher than 9MPa. It can be inferred that T-type dimer leads to CO2 physical properties changing tempestuously under supercritical state. The effect that lubricating oil has on microstructure and heat transfer of supercritical CO2 is also investigated in the present work. The results show the lubricating oil produces significant effect on the dimers' structure under low pressure.

  18. Modeling and optimization of a concentrated solar supercritical CO2 power plant

    Science.gov (United States)

    Osorio, Julian D.

    Renewable energy sources are fundamental alternatives to supply the rising energy demand in the world and to reduce or replace fossil fuel technologies. In order to make renewable-based technologies suitable for commercial and industrial applications, two main challenges need to be solved: the design and manufacture of highly efficient devices and reliable systems to operate under intermittent energy supply conditions. In particular, power generation technologies based on solar energy are one of the most promising alternatives to supply the world energy demand and reduce the dependence on fossil fuel technologies. In this dissertation, the dynamic behavior of a Concentrated Solar Power (CSP) supercritical CO2 cycle is studied under different seasonal conditions. The system analyzed is composed of a central receiver, hot and cold thermal energy storage units, a heat exchanger, a recuperator, and multi-stage compression-expansion subsystems with intercoolers and reheaters between compressors and turbines respectively. The effects of operating and design parameters on the system performance are analyzed. Some of these parameters are the mass flow rate, intermediate pressures, number of compression-expansion stages, heat exchangers' effectiveness, multi-tank thermal energy storage, overall heat transfer coefficient between the solar receiver and the environment and the effective area of the recuperator. Energy and exergy models for each component of the system are developed to optimize operating parameters in order to lead to maximum efficiency. From the exergy analysis, the components with high contribution to exergy destruction were identified. These components, which represent an important potential of improvement, are the recuperator, the hot thermal energy storage tank and the solar receiver. Two complementary alternatives to improve the efficiency of concentrated solar thermal systems are proposed in this dissertation: the optimization of the system's operating

  19. Research on Flow Characteristics of Supercritical CO2 Axial Compressor Blades by CFD Analysis

    Science.gov (United States)

    Takagi, Kazuhisa; Muto, Yasushi; Ishizuka, Takao; Kikura, Hiroshige; Aritomi, Masanori

    A supercritical CO2 gas turbine of 20MPa is suitable to couple with the Na-cooled fast reactor since Na - CO2 reaction is mild at the outlet temperature of 800K, the cycle thermal efficiency is relatively high and the size of CO2 gas turbine is very compact. In this gas turbine cycle, a compressor operates near the critical point. The property of CO2 and then the behavior of compressible flow near the critical point changes very sharply. So far, such a behavior is not examined sufficiently. Then, it is important to clarify compressible flow near the critical point. In this paper, an aerodynamic design of the axial supercritical CO2 compressor for this system has been carried out based on the existing aerodynamic design method of Cohen1). The cycle design point was selected to achieve the maximum cycle thermal efficiency of 43.8%. For this point, the compressor design conditions were determined. They are a mass flow rate of 2035kg/s, an inlet temperature of 308K, an inlet static pressure of 8.26MPa, an outlet static pressure of 20.6MPa and a rotational speed of 3600rpm. The mean radius was constant through axial direction. The design point was determined so as to keep the diffusion factor and blade stress within the allowable limits. Number of stages and an expected adiabatic efficiency was 14 and 87%, respectively. CFD analyses by FLUENT have been done for this compressor blade. The blade model consists of one set of a guide vane, a rotor blade and a stator blade. The analyses were conducted under the assumption both of the real gas properties and also of the modified ideal gas properties. Using the real gas properties, analysis was conducted for the 14th blade, whose condition is remote from the critical point and the possibility of divergence is very small. Then, the analyses were conducted for the blade whose conditions are nearer to the critical point. Gradually, divergence of calculation was encountered. Convergence was relatively easy for the modified ideal

  20. Forsterite Carbonation in Wet Supercritical CO2 and Sodium Citrate

    Science.gov (United States)

    Qiu, L.; Schaef, T.; Wang, Z.; Miller, Q.; McGrail, P.

    2013-12-01

    CO3-3H2O], which reached a maximum concentration of 85 wt% within ~30 hours of the experiment before decreasing below detection limit. Detection of the anhydrous magnesium carbonate, magnesite [MgCO3], first occurred at 15 hours, but increased dramatically over the remaining course of the experiment to levels near 90 wt%. In contrast, the presence of sodium citrate solutions in the reactor could eliminate the formation of nesquehonite. Based on the in situ HXRD results, nesquehonite did not form during experiments having sodium citrate solutions of 0.1 M, and the forsterite carbonation proceeded directly to magnesite at a concentration 90 wt% after 80 hours. Testing with less or more concentrated sodium citrate solutions (0.01 or 0.5 M), the nesquehonite formation was not attenuated or overall carbonation rates were decreased, respectively. These results indicate the possibility of organic compounds to dissolve into wet supercritical CO2 fluids and impact the formation of hydrated crystalline carbonates (often considered as transitional phases in carbonation routes to more stable minerals). Likely processes under consideration include the formation of organic complexes with metal cations in the thin water film. These results also have implications for ex situ carbonation processes and highlight the possibility of utilizing organic additives to enhance mineral dissolution prior to carbonation.

  1. [Supercritical CO2 extraction and component analysis of Aesculus wilsonii seed oil].

    Science.gov (United States)

    Chen, Guang-Yu; Shi, Zhao-Hua; Li, Hai-Chi; Ge, Fa-Huan; Zhan, Hua-Shu

    2013-03-01

    To research the optimal extraction process of supercritical CO2 extraction and analyze the component of the oil extracted from Aesculus wilsonii seed. Using the yield of Aesculus wilsonii seed oil as the index, optimized supercritical CO2 extraction parameter by orthogonal experiment methodology and analysed the compounds of Aesculus wilsonii seed oil by GC-MS. The optimal parameters of the supercritical CO2 extraction of the oil extracted from Aesculus wilsoniit seed were determined: the extraction pressure was 28 MPa and the temperature was 38 degrees C, the separation I pressure was 12 MPa and the temperature was 40 degrees C, the separation II pressure was 5 MPa and the temperature was 40 degrees C, the extraction time was 110 min. The average extraction rate of Aesculus wilsonii seed oil was 1.264%. 26 kinds of compounds were identified by GC-MS in Aesculus wilsonii seed oil extracted by supercritical CO2. The main components were fatty acids. Comparing with the petroleum ether extraction, the supercritical CO2 extraction has higher extraction rate, shorter extraction time, more clarity oil. The kinds of fatty acids with high amounts in Aesculus wilsonii seed oil is identical in general, the kinds of fatty acids with low amounts in Aesculus wilsonii seed oil have differences.

  2. Use of reverse osmosis membranes for the separation of lemongrass essential oil and supercritical CO2

    Directory of Open Access Journals (Sweden)

    L.A.V. Sarmento

    2004-06-01

    Full Text Available Although it is still used very little by industry, the process of essential oil extraction from vegetable matrices with supercritical CO2 is regarded as a potentially viable technique. The operation of separating the extract from the solvent is carried out by reducing the pressure in the system. Separation by membranes is an alternative that offers lower energy consumption and easier operation than traditional methods of separation. Combining the processes essential oil extraction with supercritical CO2 and separation by membranes permits the separation of solvent and oil without the need for large variations in extraction conditions. This results in a large energy savings in the case of solvent repressurisation and reuse. In this study, the effectiveness of reverse osmosis membranes in separating lemongrass essential oil from mixtures with supercritical CO2 was tested. The effects of feed oil concentration and transmembrane pressure on CO2 permeate flux and oil retention were studied for three membrane models.

  3. [Extraction of 10-Deacetyl Baccatin by Supercritical CO2 from Taxus yunnanensis Branches and Leaves].

    Science.gov (United States)

    Tang, Yang-qin; Li, Hai-chi; Huang, Wen-jie; Xiong, Yan; Ge, Fa-huan

    2015-04-01

    To study the supercritical CO2 fluids extraction (SFE) method to extract the components from Taxus yunnanensis. Medicinal meterials were extracted by supercritical CO2, and then purified by industrial chromatography. Using the extraction yield of 10-DAB as the index,single factor test was carried out to investigate the effect of co-solvent, extraction time, extraction pressure, extraction temperature, pressure and temperature of separation kettle I. Then orthogonal experiment was used to optimize the best extraction condition. The suitable extraction condition was as follows: the ratio of co-solvent (80% ethanol) amount and the madicinal materials was 3: 1, Separation kettle I pressure was 14 MPa, separation kettle I temperature was 40 °C, extraction pressure was 25 MPa, extraction temperature was 60 T and extraction time was 90 min. The extract was separated by industrial chromatographic and then crystallized. The supercritical CO2 extraction and purification process of 10-DAB were simple and feasible.

  4. Combination of supercritical CO2 and vacuum distillation for the fractionation of bergamot oil.

    Science.gov (United States)

    Fang, Tao; Goto, Motonobu; Sasaki, Mitsuru; Hirose, Tsutomu

    2004-08-11

    Supercritical CO2 can be used to separate oxygenated compounds from essential oils. This technique still cannot replace vacuum distillation as an industrial process because of low recoveries and inconsistent results. In the present work, a comparison between the two methods was made in terms of composition, recovery, and color. Vacuum distillation and supercritical CO2 are complementary processes for producing high quality oxygenated compounds with high recovery rates. The former is more suitable for removing monoterpenes at low fraction temperatures ( or =85%) and without other macromolecules, such as pigments and waxes.

  5. [Supercritical CO2 fluid extraction of Rosmarinus officinalis and capability of extracts eliminate OH radical].

    Science.gov (United States)

    Zhang, Chong; Li, Jia-Cheng; Zhang, De-La; Feng, Yu-Hong; Zhang, Ya-Nan; Chen, Si-Li

    2008-05-01

    Supercritical CO2 fluid extraction process of antioxidation active components from Rosmarinus officinalis was studied. A new extraction process of components extracted from R. officinalis by supercritical CO2 fluid extraction (SFE-CO2 ) was studied in detail. The capability of that the extract eliminate *OH radical was tested by electron paramagnetic resonance (EPR) technique and spin catch technique. With free radical clearance as index, by range and variance analysis, the optimum extraction process conditions were: keeping pressure at 30 MPa and temperature at 75 degrees C for 1 h, in the same time adding alcohol 0.30 mL x g(-1).

  6. CFD analysis of supercritical CO2 used as HTF in a solar tower receiver

    Science.gov (United States)

    Roldán, M. I.; Fernández-Reche, J.

    2016-05-01

    The relative cost of a solar receiver can be minimized by the selection of an appropriate heat transfer fluid capable of achieving high receiver efficiencies. In a conventional central receiver system, the concentrated solar energy is transferred from the receiver tube walls to the heat transfer fluid (HTF), which passes through a heat exchanger to generate steam for a Rankine cycle. Thus, higher working fluid temperature is associated with greater efficiency in receiver and power cycle. Emerging receiver designs that can enable higher efficiencies using advanced power cycles, such as supercritical CO2 (s-CO2) closed-loop Brayton cycles, include direct heating of s-CO2 in tubular receiver designs capable of withstanding high internal fluid pressures (around 20 MPa) and temperatures (900 K). Due to the high pressures required and the presence of moving components installed in pipelines (ball-joints and/or flexible connections), the use of s-CO2 presents many technical challenges due to the compatibility of seal materials and fluid leakages of the moving connections. These problems are solved in solar tower systems because the receiver is fixed. In this regard, a preliminary analysis of a tubular receiver with s-CO2 as HTF has been developed using the design of a molten-salt receiver which was previously tested at Plataforma Solar de Almería (PSA). Therefore, a simplified CFD model has been carried out in this study in order to analyze the feasibility of s-CO2 as HTF in solar towers. Simulation results showed that the heat gained by s-CO2 was around 75% greater than the one captured by molten salts (fluid inlet temperature of 715 K), but at a pressure range of 7.5-9.7 MPa. Thus, the use of s-CO2 as HTF in solar tower receivers appears to be a promising alternative, taking into account both the operating conditions required and their maintenance cost.

  7. The combined extraction of sage (Salvia officinalis L.): ultrasound followed by supercritical CO2 extraction.

    Science.gov (United States)

    Glisic, Sandra B; Ristic, Mihajlo; Skala, Dejan U

    2011-01-01

    A wide spectrum of phytochemicals could be isolated from sage (Salvia officinalis L.) using different extraction or distillation technique: the supercritical fluid extraction (SFE), the volatiles compounds (monoterpenes and sesquiterpenes) isolation using hydrodistillation or higher molecular compounds with Soxhlet extraction or ultrasound-assisted extraction. The combination of ultrasound-assisted extraction followed by re-extraction of obtained extract with supercritical CO(2) was performed in this study. The goal of performed investigation was to concentrate diterpenes present in sage extract which are generally considered to be responsible for antioxidant activity of extracted compounds. The fractionation using the supercritical CO(2), and different combination of the ultrasound-assisted solvent extractions (water-ethanol mixture or only water) followed by supercritical CO(2) re-extraction of obtained extract or treated plant material were analyzed and compared. Based on the results of these investigations it could be proposed the best extraction procedure: the ultrasound pretreatment of plant material with distilled water and re-extraction of plant material (residue) using supercritical CO(2). That procedure gives two valuable products: the ultrasound extract which is rich in sugars and possess the immunomodulatory activity and supercritical extract which is rich in diterpenes and sesquiterpenes.

  8. Use of liquid/supercritical CO2 extraction process for butanol recovery from fermentation broth

    Science.gov (United States)

    In order for butanol fermentation to be a viable option, it is essential to recover it from fermentation broth using economical alternate in-situ product recovery techniques such as liquid/supercritical CO2 extraction as compared to distillation. This technique (liquid CO2 extraction & supercritical...

  9. Supercritical CO2-assisted preparation of ibuprofen loaded PEG-PVP complexes

    CSIR Research Space (South Africa)

    Labuschagne, Philip W

    2010-06-01

    Full Text Available Stoichiometric ratios of poly (ethylene glycol) (PEG, Mw = 400) with poly(vinylpyrrolidone) (PVP, Mw = ±3.1 x 104 & Mw = 1.25 x 106 Mw) were prepared from ethanol cast solutions and in supercritical CO2. The complex formation was studied via glass...

  10. Relationship between the density of supercritical CO2 +ethanol binary system and its critical properties

    Institute of Scientific and Technical Information of China (English)

    张敬畅; 张建军; 曹维良

    2003-01-01

    The dependent relation between temperature and pressure of supercritical CO2 + ethanol binary system under the pressure range from 5 to 10 MPa with the variety of densities and mole fractions of ethanol that range from 0 to 2% was investigated by the static visual method in a constant volume. The critical temperature and pressure were experimentally determined simultaneously. The PTρ figures at different ethanol contents were described based on the determined pressure and temperature data, from which pressure of supercritical CO2 + ethanol binary system was found to increase linearly with the increasing temperature. P-T lines show certain convergent feature in a specific concentration of ethanol and the convergent points shift to the region of higher temperature and pressure with the increasing ethanol compositions. Furthermore, the effect of density and ethanol concentration on the critical point of CO2 + ethanol binary system was discussed in details. Critical points increase linearly with the increasing mole fraction of ethanol in specific density and critical points change at different densities. The critical compressibility factors Zc of supercritical CO2 + ethanol binary systems at different compositions of ethanol were calculated and Zc-ρ figure was obtained accordingly. It was found from Zc-ρ figure that critical compressibility factors of supercritical CO2 unitary or binary systems decline linearly with the increasing density, by which the critical point can be predicted precisely.

  11. Cosolvent Effect on the Tautomerism of Ethyl Acetoacetate in Supercritical CO2

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The effect of cosolvent cyclohexane, chloroform, and acetonitrile on the keto-enol tautomeric equilibrium of ethyl acetoacetate in supercritical CO2 was studied by UV-Vis spectroscopy over the pressure range from 76 to 110 bar at 308.15 K. It was found that the equilibrium constant decreases with increasing polarity of the cosolvents.

  12. Materials, Turbomachinery and Heat Exchangers for Supercritical CO2 Systems

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Mark; Nellis, Greg; Corradini, Michael

    2012-10-19

    The objective of this project is to produce the necessary data to evaluate the performance of the supercritical carbon dioxide cycle. The activities include a study of materials compatibility of various alloys at high temperatures, the heat transfer and pressure drop in compact heat exchanger units, and turbomachinery issues, primarily leakage rates through dynamic seals. This experimental work will serve as a test bed for model development and design calculations, and will help define further tests necessary to develop high-efficiency power conversion cycles for use on a variety of reactor designs, including the sodium fast reactor (SFR) and very high-temperature gas reactor (VHTR). The research will be broken into three separate tasks. The first task deals with the analysis of materials related to the high-temperature S-CO{sub 2} Brayton cycle. The most taxing materials issues with regard to the cycle are associated with the high temperatures in the reactor side heat exchanger and in the high-temperature turbine. The system could experience pressures as high as 20MPa and temperatures as high as 650°C. The second task deals with optimization of the heat exchangers required by the S-CO{sub 2} cycle; the S-CO{sub 2} flow passages in these heat exchangers are required whether the cycle is coupled with a VHTR or an SFR. At least three heat exchangers will be required: the pre-cooler before compression, the recuperator, and the heat exchanger that interfaces with the reactor coolant. Each of these heat exchangers is unique and must be optimized separately. The most challenging heat exchanger is likely the pre-cooler, as there is only about a 40°C temperature change but it operates close to the CO{sub 2} critical point, therefore inducing substantial changes in properties. The proposed research will focus on this most challenging component. The third task examines seal leakage through various dynamic seal designs under the conditions expected in the S-CO{sub 2} cycle

  13. Extraction of lapachol from Tabebuia avellanedae wood with supercritical CO2: an alternative to Soxhlet extraction?

    Directory of Open Access Journals (Sweden)

    Viana L.M.

    2003-01-01

    Full Text Available The solubility of lapachol in supercritical CO2 was determined at 40°C and pressures between 90 and 210 bar. Supercritical fluid extraction of lapachol and some related compounds by CO2 from Tabebuia avellanedae wood is compared to Soxhlet extraction with different solvents. A standard macroscale (100-200 g wood and a microscale (~10 mg wood experimental setup are described and their results are compared. The latter involved direct spectrophotometric quantification in a high-pressure autoclave with an integrated optical path and a magnetic stirrer, fitted directly into a commercial spectrophotometer. The relative amount of lapachol extracted by supercritical CO2 at 40°C and 200 bar was about 1.7%, which is similar to the results of Soxhlet extractions. Lower contents of alpha- and beta-lapachone as well as dehydro-alpha-lapachone are also reported.

  14. Chemicals loading in acetylated bamboo assisted by supercritical CO2 based on phase equilibrium data

    Science.gov (United States)

    Silviana, Petermann, M.

    2015-12-01

    Indonesia has a large tropical forest. However, the deforestation still appears annually and vastly. This reason drives a use of bamboo as wood alternative. Recently, there are many modifications of bamboo in order to prolong the shelf life. Unfortunately, the processes need more chemicals and time. Based on wood modification, esterifying of bamboo was undertaken in present of a dense gas, i.e. supercritical CO2. Calculation of chemicals loading referred to ASTM D1413-99 by using the phase equilibrium data at optimum condition by a statistical design. The results showed that the acetylation of bamboo assisted by supercritical CO2 required 14.73 kg acetic anhydride/m3 of bamboo for a treatment of one hour.

  15. Extraction of lapachol from Tabebuia avellanedae wood with supercritical CO2: an alternative to Soxhlet extraction?

    Directory of Open Access Journals (Sweden)

    L.M. Viana

    2003-09-01

    Full Text Available The solubility of lapachol in supercritical CO2 was determined at 40°C and pressures between 90 and 210 bar. Supercritical fluid extraction of lapachol and some related compounds by CO2 from Tabebuia avellanedae wood is compared to Soxhlet extraction with different solvents. A standard macroscale (100-200 g wood and a microscale (~10 mg wood experimental setup are described and their results are compared. The latter involved direct spectrophotometric quantification in a high-pressure autoclave with an integrated optical path and a magnetic stirrer, fitted directly into a commercial spectrophotometer. The relative amount of lapachol extracted by supercritical CO2 at 40°C and 200 bar was about 1.7%, which is similar to the results of Soxhlet extractions. Lower contents of alpha- and beta-lapachone as well as dehydro-alpha-lapachone are also reported.

  16. Swelling-induced changes in coal microstructure due to supercritical CO2 injection

    Science.gov (United States)

    Zhang, Yihuai; Lebedev, Maxim; Sarmadivaleh, Mohammad; Barifcani, Ahmed; Iglauer, Stefan

    2016-09-01

    Enhanced coalbed methane recovery and CO2 geostorage in coal seams are severely limited by permeability decrease caused by CO2 injection and associated coal matrix swelling. Typically, it is assumed that matrix swelling leads to coal cleat closure, and as a consequence, permeability is reduced. However, this assumption has not yet been directly observed. Using a novel in situ reservoir condition X-ray microcomputed tomography flooding apparatus, for the first time we observed such microcleat closure induced by supercritical CO2 flooding in situ. Furthermore, fracturing of the mineral phase (embedded in the coal) was observed; this fracturing was induced by the internal swelling stress. We conclude that coal permeability is drastically reduced by cleat closure, which again is caused by coal matrix swelling, which again is caused by flooding with supercritical CO2.

  17. Metal extraction from the artificially contaminated soil using supercritical CO2 with mixed ligands.

    Science.gov (United States)

    Park, Kwangheon; Lee, Jeongken; Sung, Jinhyun

    2013-04-01

    Supercritical fluids have good penetrating power with a high capacity to dissolve certain solutes in the fluid itself, making it applicable for soil cleaning. Supercritical CO2 along with mixed ligands has been used for cleaning artificially contaminated soil. The extraction of metal from the soil was successful, and the molar ratio of ligands to the extracted metal was as low as 3. Complicated structures with a large surface area of the real soil seemed to cause the lower efficiency. Reduced efficiency was also observed over time after the sample preparation, indicating the possibility of chemisorption of the metal ion onto the soil. The use of supercritical CO2 with dissolved mixed ligands was sufficient to extract metal from the soil. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Catalytic nanoreactors in continuous flow: hydrogenation inside single-walled carbon nanotubes using supercritical CO2.

    Science.gov (United States)

    Chamberlain, Thomas W; Earley, James H; Anderson, Daniel P; Khlobystov, Andrei N; Bourne, Richard A

    2014-05-25

    One nanometre wide carbon nanoreactors are utilised as the reaction vessel for catalytic chemical reactions on a preparative scale. Sub-nanometre ruthenium catalytic particles which are encapsulated solely within single-walled carbon nanotubes offering a unique reaction environment are shown to be active when embedded in a supercritical CO2 continuous flow reactor. A range of hydrogenation reactions were tested and the catalyst displayed excellent stability over extended reaction times.

  19. Cold Pressing and Supercritical CO2 Extraction of Hemp (Cannabis sativa) Seed Oil

    OpenAIRE

    Aladić, K.; S. Jokić; Moslavac, T.; Tomas, S.; S Vidović; Vladić, J.; Šubarić, D.

    2015-01-01

    In the past few decades, the Cannabis sativa L. hemp variety has been unfairly neglected because of its similarity to the illegal kind Cannabis indica used as a narcotic. The objective of this study was to evaluate the process of oil extraction from Cannabis sativa seeds by cold pressing, followed by extraction with supercritical CO2. In the pressing experiments, the response surface methodology was conducted in order to study the effects of temperature, frequency, and nozzle size on oil reco...

  20. Cold Pressing and Supercritical CO2 Extraction of Hemp (Cannabis sativa) Seed Oil

    OpenAIRE

    Aladić, K.; S. Jokić; Moslavac, T.; Tomas, S.; S Vidović; Vladić, J.; Šubarić, D.

    2015-01-01

    In the past few decades, the Cannabis sativa L. hemp variety has been unfairly neglected because of its similarity to the illegal kind Cannabis indica used as a narcotic. The objective of this study was to evaluate the process of oil extraction from Cannabis sativa seeds by cold pressing, followed by extraction with supercritical CO2. In the pressing experiments, the response surface methodology was conducted in order to study the effects of temperature, frequency, and nozzle size on oil reco...

  1. Plant Growth Biostimulants, Dietary Feed Supplements and Cosmetics Formulated with Supercritical CO2 Algal Extracts

    OpenAIRE

    Izabela Michalak; Katarzyna Chojnacka; Agnieszka Saeid

    2017-01-01

    The review paper presents the use of algal extracts as safe and solvent-free components of plant growth biostimulants, dietary feed additives and cosmetics. Innovative technology that uses extracts obtained by supercritical CO2 extraction, as a method of isolation of biologically active compounds from algal biomass, is presented. An important part of the complete technology is the final formulation of the product. This enabled realization of the further step which was assessment of the utilit...

  2. Water-in-Supercritical CO2 Microemulsion Stabilized by a Metal Complex.

    Science.gov (United States)

    Luo, Tian; Zhang, Jianling; Tan, Xiuniang; Liu, Chengcheng; Wu, Tianbin; Li, Wei; Sang, Xinxin; Han, Buxing; Li, Zhihong; Mo, Guang; Xing, Xueqing; Wu, Zhonghua

    2016-10-17

    Herein we propose for the first time the utilization of a metal complex for forming water-in-supercritical CO2 (scCO2 ) microemulsions. The water solubility in the metal-complex-stabilized microemulsion is significantly improved compared with the conventional water-in-scCO2 microemulsions stabilized by hydrocarbons. Such a microemulsion provides a promising route for the in situ CO2 reduction catalyzed by a metal complex at the water/scCO2 interface.

  3. Solubility of caffeine from green tea in supercritical CO2: a theoretical and empirical approach.

    Science.gov (United States)

    Gadkari, Pravin Vasantrao; Balaraman, Manohar

    2015-12-01

    Decaffeination of fresh green tea was carried out with supercritical CO2 in the presence of ethanol as co-solvent. The solubility of caffeine in supercritical CO2 varied from 44.19 × 10(-6) to 149.55 × 10(-6) (mole fraction) over a pressure and temperature range of 15 to 35 MPa and 313 to 333 K, respectively. The maximum solubility of caffeine was obtained at 25 MPa and 323 K. Experimental solubility data were correlated with the theoretical equation of state models Peng-Robinson (PR), Soave Redlich-Kwong (SRK), and Redlich-Kwong (RK). The RK model had regressed experimental data with 15.52 % average absolute relative deviation (AARD). In contrast, Gordillo empirical model regressed the best to experimental data with only 0.96 % AARD. Under supercritical conditions, solubility of caffeine in tea matrix was lower than the solubility of pure caffeine. Further, solubility of caffeine in supercritical CO2 was compared with solubility of pure caffeine in conventional solvents and a maximum solubility 90 × 10(-3) mol fraction was obtained with chloroform.

  4. The effect of selected supercritical CO2 plant extract addition on user properties of shower gels

    Directory of Open Access Journals (Sweden)

    Vogt Otmar

    2014-12-01

    Full Text Available The formulations of washing cosmetics i.e. shower gels, containing extracts obtained during supercritical CO2 extraction process as active ingredient, were developed. The subject of the study was the analysis of the physicochemical and user properties of the obtained products. In the work supercritical CO2 extracts of black currant seeds, strawberry seeds, hop cones and mint leafs were used. The formulation contains a mixture of surfactants (disodium cocoamphodiacetate, disodium laureth sulfosuccinate, cocoamide DEA, cocoamidepropyl betaine, Sodium Laureth Sulfate. Various thickener agents were applied to the obtained desired rheological properties of the cosmetics. Among others, sorbitol acetal derivatives, methylhydroxypropylcellulose and C10-30 alkyl acrylate crosspolymer were used. For stable products, the effect of extracts addition (black currants seeds, strawberries seeds, mint and hops, obtained from supercritical CO2 extraction process on the cosmetics properties, such as pH, viscosity, detergency and foam ability, were determined. The obtained results showed that the extracts could be used as components of shower gels.

  5. Experimental Evaluation of Permeability of Coal in Supercritical CO2 and N2 Injection Under Stress and Strain Restricted Conditions

    National Research Council Canada - National Science Library

    KIYAMA, Tamotsu; NISHIMOTO, Soshi; FUJIOKA, Masaji; XUE, Zique; MIYAZAWA, Daisuke; ISHIJIMA, Yoji

    2010-01-01

    .... In this study, the strain and stress constraint conditions were created in-laboratory and N2 and supercritical CO2 were injected repeatedly in a coal specimen for observation of the permeability, Vp...

  6. Flow of subcritical and supercritical CO2 in coal at variable insitu conditions

    Science.gov (United States)

    Vishal, V.

    2016-12-01

    Fluid flow in unconventional reservoirs is influenced by various conditions such as the insitu pressure, temperature, pore pressure, effective stresses, reservoir characteristics such as porosity, permeability, etc. Many laboratory, pilot scale and field scale activities have only enhanced the understanding of these reservoirs such as shale and coal. An important domain of investigation, however, is the phase of the fluid itself. CO2 that is being injected into the subsurface for the purpose of geologic sequestration is likely to experience a transition of phases in the reservoirs. The present work examines the effects of change in phase of CO2 on the permeability evolution of porous coal. Experiments were conducted to examine the effects of change of phase of CO2 from gas to liquid and gas to supercritical state on the flow and deformation of coal. It was found that the permeability of coal to supercritical CO2 was nearly half than that using liquid CO2. Further, upon saturation of the sample for two days using CO2, further reduction of permeability was observed. Saturation with liquid CO2 led to nearly 24% decline in permeability of coal while supercritical CO2 led to nearly 40% reduction in the same. It is hypothesized that liquid and supercritical CO2 lead to large amount of coal matrix deformation and in turn, the matrix swelling leads to the closure of path of fluid flow, resulting in high reduction of permeability. This study presents the real-term underground scenarios likely to be encountered during CO2 flow in coal.

  7. The influence of water and supercritical CO2 on the failure behavior of chalk

    Science.gov (United States)

    Liteanu, E.; Spiers, C. J.; de Bresser, J. H. P.

    2013-06-01

    Reduction of compressive strength by injection of water into chalk is a well-known mechanism responsible for increased compaction in chalk reservoirs. This raises the question of whether such effects might be enhanced in the context of long-term storage of CO2 or of CO2 injection for enhanced oil and gas recovery (EOR/EGR) purposes. Therefore, data regarding the effect of supercritical CO2 on the mechanical behavior of chalk are needed. The effect of supercritical CO2 on the short-term failure behavior of wet chalk was accordingly investigated by means of conventional triaxial deformation experiments, performed on Maastrichtian chalk cores under dry conditions, in the presence of saturated chalk solution and using CO2-saturated solution at temperatures simulating reservoir conditions (20-80 °C) and effective confining pressures up to 7 MPa. Increasing temperature from 20 to 80 °C did not show any significant effects on the strength of the dry samples. Addition of aqueous solution to the samples led to drastic weakening of the chalk, the effect being more pronounced at high effective confining pressures (Peff > 3 MPa). Addition of 10 MPa supercritical CO2 to wet samples did not produce any significant additional effect in comparison with the wet samples. All samples showed a yield strength envelope characterized by shear failure at low effective mean stresses giving way to a compaction cap at high mean stresses. The weakening effect of aqueous solution was explained in terms of a reduction in frictional resistance of the material, due to water-enhanced grain-contact cracking, and perhaps pressure solution, with a possible contribution by disjoining pressure effects caused by water adsorption. While CO2 does not seem to reduce short-term failure strength of wet chalk, processes such as intergranular pressure solution have to be considered for assessing mechanical stability of chalk in the context of long-term CO2 storage or EOR/EGR operations.

  8. Supercritical CO2 recovery of caffeine from green coffee oil: new experimental solubility data and modeling

    OpenAIRE

    Azevedo, Álvaro Bandeira Antunes de; Kieckbusch,Theo Guenter; Tashima,Alexandre Keiji; Mohamed,Rahoma Sadeg; Mazzafera,Paulo; Melo, Silvio Alexandre Beisl Vieira de

    2008-01-01

    p. 1319-1323. The caffeine solubility in supercritical CO2 was studied by assessing the effects of pressure and temperature on the extraction of green coffee oil (GCO). The Peng-Robinson1 equation of state was used to correlate the solubility of caffeine with a thermodynamic model and two mixing rules were evaluated: the classical mixing rule of van der Waals with two adjustable parameters (PR-VDW) and a density dependent one, proposed by Mohamed and Holder2 with two (PR-MH, two parameters...

  9. Supercritical CO 2 -philic nanoparticles suitable for determining the viability of carbon sequestration in shale

    KAUST Repository

    Xu, Yisheng

    2015-01-01

    © The Royal Society of Chemistry. A fracture spacing less than a decimeter is probably required for the successful sequestration of CO2 in shale. Tracer experiments using inert nanoparticles could determine if a fracturing this intense has been achieved. Here we describe the synthesis of supercritical CO2-philic nanoparticles suitable for this application. The nanoparticles are ~50 nm in diameter and consist of iron oxide (Fe3O4) and silica (SiO2) cores functionalized with a fluorescent polymeric corona. The nanoparticles stably disperse in supercritical carbon dioxide (scCO2) and are detectable to concentrations of 10 ppm. This journal is

  10. Non-catalytic transfer hydrogenation in supercritical CO2 for coal liquefaction

    Science.gov (United States)

    Elhussien, Hussien

    This thesis presents the results of the investigation on developing and evaluating a low temperature (coal dissolution in supercritical CO2. The main idea behind the thesis was that one hydrogen atom from water and one hydrogen atom from the hydrogen transfer agent (HTA) were used to hydrogenate the coal. The products of coal dissolution were non-polar and polar while the supercritical CO2, which enhanced the rates of hydrogenation and dissolution of the non-polar molecules and removal from the reaction site, was non-polar. The polar modifier (PM) for CO2 was added to the freed to aid in the dissolution and removal of the polar components. The addition of a phase transfer agent (PTA) allowed a seamless transport of the ions and by-product between the aqueous and organic phases. DDAB, used as the PTA, is an effective phase transfer catalyst and showed enhancement to the coal dissolution process. COAL + DH- +H 2O → COAL.H2 + DHO-- This process has a great feature due to the fact that the chemicals were obtained without requir-ing to first convert coal to CO and H2 units as in indirect coal liquefaction. The experiments were conducted in a unique reactor set up that can be connected through two lines. one line to feed the reactor with supercritical CO 2 and the other connected to gas chromatograph. The use of the supercritical CO2 enhanced the solvent option due to the chemical extraction, in addition to the low environmental impact and energy cost. In this thesis the experiment were conducted at five different temperatures from atmos-pheric to 140°C, 3000 - 6000 psi with five component of feed mixture, namely water, HTA, PTA, coal, and PM in semi batch vessels reactor system with a volume of 100 mL. The results show that the chemicals were obtained without requiring to first convert coal to CO and H2 units as in indirect coal liquefaction. The results show that the conversion was found to be 91.8% at opti-mum feed mixtures values of 3, 1.0 and 5.4 for water: PM

  11. [The extraction technology of epigoitri from isatidis radix by supercritical CO2 fluid].

    Science.gov (United States)

    Nian, Si-Hui; Liu, Chun-Yun; Liu, Li-Min; Yang, Li-Fen

    2013-07-01

    To study the extraction technology of epigoitri from Isatidis Radix by supercritical CO2 fluid. The effects of pressure, temperature, time, concentration and dosage of alcohol were studied by single factor analysis and orthogonal test. The optimized conditions were as follows: The pressure was 20 MPs, the temperature was 50 degrees C, the time was 2 h, concentration of alcohol was 100%, dosage was 80 mL. The content of epigoitri in the extract could reach 38.63% under the above conditions. This method is simple, rapid and it is suitable for the extraction of epigoitri from Isatidis Radix.

  12. Supercritical CO2 Extraction of Rice Bran Oil -the Technology, Manufacture, and Applications.

    Science.gov (United States)

    Sookwong, Phumon; Mahatheeranont, Sugunya

    2017-06-01

    Rice bran is a good source of nutrients that have large amounts of phytochemicals and antioxidants. Conventional rice bran oil production requires many processes that may deteriorate and degrade these valuable substances. Supercritical CO2 extraction is a green alternative method for producing rice bran oil. This work reviews production of rice bran oil by supercritical carbon dioxide (SC-CO2) extraction. In addition, the usefulness and advantages of SC-CO2 extracted rice bran oil for edible oil and health purpose is also described.

  13. Supercritical CO2 extraction of mentha (Mentha piperita L. at different solvent densities

    Directory of Open Access Journals (Sweden)

    DUŠAN ADAMOVIĆ

    2009-04-01

    Full Text Available The chemical composition of mentha essential oil and mentha extracts obtained at different pressures/temperatures by supercritical fluid extraction (SFE were studied by GC–MS. The menthol content was also determined spectrophotometrically. The predominant compounds in the essential oil and in the CO2 extract obtained at 100 bar were L-menthon and menthole but at higher pressures (from 150 to 400 bar, squalene was dominant. The equation of Naik et al. was used for modelling the mentha–supercritical CO2 system.

  14. Clay hydration/dehydration in dry to water-saturated supercritical CO2: Implications for caprock integrity

    Energy Technology Data Exchange (ETDEWEB)

    Loring, John S.; Schaef, Herbert T.; Thompson, Christopher J.; Turcu, Romulus VF; Miller, Quin R.; Chen, Jeffrey; Hu, Jian Z.; Hoyt, David W.; Martin, Paul F.; Ilton, Eugene S.; Felmy, Andrew R.; Rosso, Kevin M.

    2013-01-01

    Injection of supercritical CO2 (scCO2) for the geologic storage of carbon dioxide will displace formation water, and the pore space adjacent to overlying caprocks could eventually be dominated by dry to water-saturated scCO2. Wet scCO2 is highly reactive and capable of carbonating and hydrating certain minerals, whereas anhydrous scCO2 can dehydrate water-containing minerals. Because these geochemical processes affect solid volume and thus porosity and permeability, they have the potential to affect the long-term integrity of the caprock seal. In this study, we investigate the swelling and shrinkage of an expandable clay found in caprock formations, montmorillonite (Ca-STx-1), when exposed to variable water-content scCO2 at 50 °C and 90 bar using a combination of in situ probes, including X-ray diffraction (XRD), in situ magic angle spinning nuclear magnetic resonance spectroscopy (MAS NMR), and in situ attenuated total reflection infrared spectroscopy (ATR-IR). We show that the extent of montmorillonite clay swelling/shrinkage is dependent not only on water hydration/dehydration, but also on CO2 intercalation reactions. Our results also suggest a competition between water and CO2 for interlayer residency where increasing concentrations of intercalated water lead to decreasing concentrations of intercalated CO2. Overall, this paper demonstrates the types of measurements required to develop fundamental knowledge that will enhance modeling efforts and reduce risks associated with subsurface storage of CO2.

  15. [Study on supercritical CO2 extraction of xiaoyaosan and its GC-MS fingerprint].

    Science.gov (United States)

    Zuo, Ya-Mei; Tian, Jun-Sheng; Guo, Xiao-Qing; Zhou, Yu-Zhi; Gao, Xiao-Xia; Qin, Xue-Mei

    2014-02-01

    To determine the optimum conditions of supercritical CO2 extraction of Xiaoyaosan, and establish its fingerprint by gas chromatography-mass spectrometry (GC-MS), the yield of extract were investigated, an orthogonal test was used to quantify the effects of extraction temperature, pressure, CO2 flow rate and time, and fingerprint analysis of different batches of extracts were by GC-MS. The optimal extraction conditions were determined as follows: extraction pressure 20 MPa, extraction temperature 50 degrees C, CO2 flow rate 25 kg x h(-1), extraction time 3 h, and average yield 2.2%. The GC-MS fingerprint was established and 27 common peaks were found, whose contents add up to 81.89% of the total peak area. Among them, 21 compounds were identified, accounting for 53.20% of the total extract. The extraction process is reasonable and favorable for industrial production. The GC-MS method is accurate, reliable, reproducible, and can be used for quality control of supercritical CO2 extract from Xiaoyaosan.

  16. MICROPOROUS PVDF-HFP-BASED POLYMER MEMBRANES FORMED FROM SUPERCRITICAL CO2 INDUCED PHASE SEPARATION

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Microporous poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)membranes following supercritical CO2 induced phase separation process were prepared using four solvents.The solid electrolytes of PVDF-HFP were formed by microporous PVDF-HFP membranes filled and swollen by a liquid electrolyte.The effect of the solvents on the morphology and structure,electrolyte absorptions and lithium ionic conductivity of the activated membranes were investigated.It was approved that all the membrane had the similar"sponge-like"and asymmetric structure when different solvent was used.As the mutual affinity between solvent and supercritical CO2 decreased,the membrane porosity and the average pore diameter increased.The PVDF-HFP membrane with porosity at 88% and pore size at 10 μm were successfully prepared.The uptake of electrolyte solution and lithium ionic conductivity could reach 487 wt% and 3.09×10-3 S/cm respectively for obtained membrane.

  17. Particle seeding enhances interconnectivity in polymeric scaffolds foamed using supercritical CO(2).

    Science.gov (United States)

    Collins, Niki J; Bridson, Rachel H; Leeke, Gary A; Grover, Liam M

    2010-03-01

    Foaming using supercritical CO(2) is a well-known process for the production of polymeric scaffolds for tissue engineering. However, this method typically leads to scaffolds with low pore interconnectivity, resulting in insufficient mass transport and a heterogeneous distribution of cells. In this study, microparticulate silica was added to the polymer during processing and the effects of this particulate seeding on the interconnectivity of the pore structure and pore size distribution were investigated. Scaffolds comprising polylactide and a range of silica contents (0-50 wt.%) were produced by foaming with supercritical CO(2). Scaffold structure, pore size distributions and interconnectivity were assessed using X-ray computed microtomography. Interconnectivity was also determined through physical measurements. It was found that incorporation of increasing quantities of silica particles increased the interconnectivity of the scaffold pore structure. The pore size distribution was also reduced through the addition of silica, while total porosity was found to be largely independent of silica content. Physical measurements and those derived from X-ray computed microtomography were comparable. The conclusion drawn was that the architecture of foamed polymeric scaffolds can be advantageously manipulated through the incorporation of silica microparticles. The findings of this study further establish supercritical fluid foaming as an important tool in scaffold production and show how a previous limitation can be overcome.

  18. Silver nanoparticles generated by pulsed laser ablation in supercritical CO2 medium

    Science.gov (United States)

    Machmudah, Siti; Sato, Takayuki; Wahyudiono; Sasaki, Mitsuru; Goto, Motonobu

    2012-03-01

    Pulsed laser ablation (PLA) has been widely employed in industrial and biological applications and in other fields. The environmental conditions in which PLA is conducted are important parameters that affect both the solid particle cloud and the deposition produced by the plume. In this work, the generation of nanoparticles (NPs) has been developed by performing PLA of silver (Ag) plates in a supercritical CO2 medium. Ag NPs were successfully generated by allowing the selective generation of clusters. Laser ablation was performed with an excitation wavelength of 532 nm under various pressures and temperatures of CO2 medium. On the basis of the experimental result, both surface of the irradiated Ag plate and structure of Ag NPs were significantly affected by the changes in supercritical CO2 pressure and temperature. With increasing irradiation pressure, plume deposited in the surrounding crater created by the ablation was clearly observed. In Field Emission Scanning Electron Microscopy (FE-SEM) the image of the generated Ag NPs on the silicon wafer and the morphology of Ag particles were basically a sphere-like structure. Ag particles contain NPs with large-varied diameter ranging from 5 nm to 1.2 μm. The bigger Ag NPs melted during the ablation process and then ejected smaller spherical Ag NPs, which formed nanoclusters attached on the molten Ag NPs. The smaller Ag NPs were also formed around the bigger Ag NPs. Based on the results, this new method can also be used to obtain advanced nano-structured materials.

  19. [Supercritical CO2 fluid extraction and component analysis of leaves oil from Taxus chinensis var. mairei].

    Science.gov (United States)

    Tang, Bin; Zhang, Feng-su; Li, Xiang; Chen, Jian-wei; Yao, Xiao

    2013-12-01

    To research the optimal extraction process of supercritical CO2 extraction and analyze the component of the oil extracted from leaves of Taxus chinensis var. mairei. Using the yield of leaves oil from Taxus chinensis var. mairei as the index, investigated the effect of the extraction pressure, extraction temperature and extraction time on the extracting-rate of leaves oil. The chemical composition of the extracted leaves oil was analyzed by derivatized GC-MS. The optimal parameters of the supercritical CO2 extraction of the oil extracted from leaves of Taxus chinensis var. mairei were determined: CO2 compressor pump frequency was 10 Hz, the extraction pressure was 25 MPa and the temperature of extraction was 45 degrees C, the extraction time was 120 min, the isolator I pressure was 8.0 MPa and the temperature of extraction was 40 degrees C, the isolator II pressure was 5.0 MPa and the temperature of extraction was 35 degrees C. The extracted leaves oil was derivatized with boron trifluoride-methanol complex. Thirty-three kinds of fatty acids were identified by GC-MS. The yield of leaves oils are different from Taxus chinensis var. mairei from 3 habitats. The yield of leaves oil from Donggang, Wuxi city is the highest, about 2.61%. The kinds of fatty acids with high amounts in leaves oil from Taxus chinensis var. mairei is identical in general, the kinds of fatty acids with low amounts in leaves oil from Taxus chinensis var. mairei have differences.

  20. A comparative study of solvent and supercritical CO2 extraction of Simarouba gluaca seed oil

    Directory of Open Access Journals (Sweden)

    B. Anjaneyulu

    2017-09-01

    Full Text Available In the present study, the supercritical carbon dioxide (CO2 extraction of oil from Simarouba gluaca seeds was carried out at varying conditions of pressure (300–500 bar, temperature (50–70 °C and CO2 flow rate (10–30 g·min-1. The extraction condition for maximum oil yield was obtained at 500 bar pressure, 70 °C and at 30 g·min-1 flow rate of CO2. The extracted oil was analyzed thoroughly for physico-chemical properties and compared with those of conventional solvent extracted oil. An interesting observation is a significant reduction in the phosphorus content of the oil (8.4 mg·kg-1 extracted using supercritical CO2 compared to the phosphorous content of the solvent extracted oil (97 mg·kg-1. Moreover, the content of total tocopherols in supercritically extracted oil (135.6 mg·kg-1 was found to be higher than the solvent extracted oil (111 mg·kg-1. The rest of the physico-chemical properties of the two differently extracted oils matched well with each other. The results indicated the possible benefits of supercritical CO2 extraction over solvent extraction of Simarouba gluaca seed oil.

  1. [Study on supercritical CO2 extraction of fatty oils from the seed of Akebia trifoliata (Thunb) Koidz].

    Science.gov (United States)

    Xie, Xiao-xia; Ge, Fa-huan

    2007-03-01

    The extraction of fatty oils from the seed of Akebia trifoliata (Thunb) Koidz with supercritical CO2 was studied. The effects of extraction pressure, extraction temperature on the yields were discussed. The optimal condition of this method was as follow: extraction pressure 30 MPa, extraction temerature 45 degrees C, separator I pressure 11 MPa, separator I temperature 50 degrees C, separator II pressure 6MPa, separator II temperature 45 degrees C, extraction period 2 hours. Compared with the traditional solvent extraction, with a GC-MS analysis, it revealed that the component extracted with supercritical CO2 was basically consistent with that extracted with petroleum ether, and it was rich unsaturated fatty acid.

  2. 3-D loaded scaffolds obtained by supercritical CO2 assisted process

    Science.gov (United States)

    Cardea, S.; Reverchon, E.

    2014-08-01

    In this work, a supercritical CO2 (SC-CO2) drying process for the formation of 3-D PVDF-HFP loaded scaffolds was tested. Experiments at pressures ranging between 150 and 250 bar and at temperatures ranging between 35 and 55°C were performed. The PVDF-HFP- acetone-ethanol solution at 15% w/w polymer was selected as the base case. The drug (amoxicillin) concentration was varied from 20 to 30% w/w with respect to PVDF-HFP. SC- CO2 drying process was confirmed to be a valid alternative to generate loaded structures; indeed, scaffolds characterized by nanometric networks (with mean pore diameter of about 300 nm) with a homogeneous drug distribution were obtained. Drug controlled release experiments were also performed and a quasi-zero order release kinetic was observed.

  3. Supercritical CO2 recovery of caffeine from green coffee oil: new experimental solubility data and modeling

    Directory of Open Access Journals (Sweden)

    Álvaro Bandeira Antunes de Azevedo

    2008-01-01

    Full Text Available The caffeine solubility in supercritical CO2 was studied by assessing the effects of pressure and temperature on the extraction of green coffee oil (GCO. The Peng-Robinson¹ equation of state was used to correlate the solubility of caffeine with a thermodynamic model and two mixing rules were evaluated: the classical mixing rule of van der Waals with two adjustable parameters (PR-VDW and a density dependent one, proposed by Mohamed and Holder² with two (PR-MH, two parameters adjusted to the attractive term and three (PR-MH3 two parameters adjusted to the attractive and one to the repulsive term adjustable parameters. The best results were obtained with the mixing rule of Mohamed and Holder² with three parameters.

  4. The experimental study of heat extraction of supercritical CO2 in the geothermal reservoir

    Directory of Open Access Journals (Sweden)

    Huang Cyun-Jie

    2016-01-01

    Full Text Available The heat transfer phenomena of supercritical CO2 are experimentally investigated in a horizontal tube for improving the efficiency of CO2-EGS.This study discuss the experimental verification of the numerical simulations. The experiment is conducted for the pressure, the flow rate, and particle size 1.54mm. In addition, the experiment and simulation that the maximum heat extraction is occurred at the 9MPa pressure and mass flow rate of 0.00109 kg/s. The maximum specific heat extraction at 9MPa and flow rate of 0.00082 kg/s. The results show that the numerical model has been experimentally verified of the feasibility. Furthermore, the pseudo-critical point had a significant influence on the heat extraction, temperature difference and specific heat extraction.

  5. Characterisation of natural fibre reinforced PLA foams prepared by supercritical CO2 assisted extrusion

    Directory of Open Access Journals (Sweden)

    K. Bocz

    2016-09-01

    Full Text Available Natural fibre reinforced polylactic acid (PLA foams, as potential green replacements for petroleum-based polymer foams, were investigated. Highly porous (ε > 95% microcellular PLA foams were manufactured by supercritical CO2 assisted extrusion process. To overcome the inherently low melt strength of PLA, epoxy-functionalized chain extender was applied, while talc was added to improve its crystallization kinetics. The combined application of chain extender and talc effectively promoted the formation of uniform cell structures. The effect of cellulose and basalt fibre reinforcement on the foamability, morphology, structure and mechanical properties of the PLA foams were investigated as well. The addition of 5 wt% natural fibres promoted the cell nucleation, but caused non-uniform distribution of cell size due to the microholes induced by local fibre-matrix debonding. The compression strength of the manufactured basalt fibre reinforced PLA foams reached 40 kPa.

  6. Drug loading of polymer implants by supercritical CO2 assisted impregnation: A review.

    Science.gov (United States)

    Champeau, M; Thomassin, J-M; Tassaing, T; Jérôme, C

    2015-07-10

    Drug loaded implants also called drug-eluting implants have proven their benefits over simple implants. Among the developed manufacturing processes, the supercritical CO2 (scCO2) assisted impregnation has attracted growing attention to load Active Pharmaceutical Ingredients into polymer implants since it enables to recover a final implant free of any solvent residue and to operate under mild temperature which is suitable for processing with thermosensitive drugs. This paper is a review of the state-of-the-art and the application of the scCO2 assisted impregnation process to prepare drug-eluting implants. It introduces the process and presents its advantages for biomedical applications. The influences of the characteristics of the implied binary systems and of the experimental conditions on the drug loading are described. Then, the various current applications of this process for manufacturing drug-eluting implants are reviewed. Finally, the new emerging variations of this process are described.

  7. [Optimization of extraction process for tannins from Geranium orientali-tibeticum by supercritical CO2 method].

    Science.gov (United States)

    Xie, Song; Tong, Zhi-Ping; Tan, Rui; Liu, Xiao-Zhen

    2014-08-01

    In order to optimize extraction process conditions of tannins from Geranium orientali-tibeticum by supercritical CO2, the content of tannins was determined by phosphomolybdium tungsten acid-casein reaction, with extraction pressure, extraction temper- ature and extraction time as factors, the content of tannins from extract of G. orientali-tibeticum as index, technology conditions were optimized by orthogonal test. Optimum technology conditions were as follows: extraction pressure was 25 MPa, extraction temperature was 50 °C, extracted 1.5 h. The content of tannins in extract was 12.91 mg x g(-1), extract rate was 3.67%. The method established could be used for assay the contents of tannin in G. orientali-tibeticum. The circulated extraction was an effective extraction process that was stable and feasible, and that provides a way of the extraction process conditions of tannin from G. orientali-tibeticum.

  8. Safety study of an experimental apparatus for extraction with supercritical CO2

    Directory of Open Access Journals (Sweden)

    V. B. Soares

    2012-09-01

    Full Text Available During the process of supercritical CO2 extraction it is necessary to use high pressures in the procedure. The explosion of a pressure vessel can be harmful to people and cause serious damage to the environment. The aim of this study is to investigate the probability of death and injury in a laboratory unit for supercritical fluid extraction in the case of an explosion of the extractor vessel. The procedure is explained via a case study involving fatty acid extraction from vegetable oils with carbon dioxide above its supercritical conditions and under optimum operating conditions. According to the results, more importance should be given to the use of a protective headset because the probability of eardrum injury is superior to the probability of death from lung injury.

  9. [Optimization of extraction process for tannins from Geranium orientali-tibeticum by supercritical CO2 method].

    Science.gov (United States)

    Xie, Song; Tong, Zhi-Ping; Tan, Rui; Liu, Xiao-Zhen

    2014-08-01

    In order to optimize extraction process conditions of tannins from Geranium orientali-tibeticum by supercritical CO2, the content of tannins was determined by phosphomolybdium tungsten acid-casein reaction, with extraction pressure, extraction temper- ature and extraction time as factors, the content of tannins from extract of G. orientali-tibeticum as index, technology conditions were optimized by orthogonal test. Optimum technology conditions were as follows: extraction pressure was 25 MPa, extraction temperature was 50 °C, extracted 1.5 h. The content of tannins in extract was 12.91 mg x g(-1), extract rate was 3.67%. The method established could be used for assay the contents of tannin in G. orientali-tibeticum. The circulated extraction was an effective extraction process that was stable and feasible, and that provides a way of the extraction process conditions of tannin from G. orientali-tibeticum.

  10. [Studies on extraction of active fraction from Rhizoma et Radix Ligustici by supercritical CO2 extraction].

    Science.gov (United States)

    Mao, Cai-Ni; He, Wei; Li, Yong; Yuan, Wan-Rui

    2008-10-01

    To study the conditions of extraction of active fraction in Rhizoma et Radix Ligustici by supercritical CO2 extraction (SFE). Using the content of ferulic acid as the index, conditions for the extraction including extracting pressure, extracting temperature, temperature of resolution and extracting time were optimized by uniform design. The best SFE conclusions were as follows: cosolvent was 50% ethanol (ml/g), extracting pressure was 40 MPa, extracting temperature was 50 degrees C, pressure of resolution was 6 MPa, temperature of resolution was 50 degrees C, extracting time was 3.5 hours. The optimum extraction has high extraction ratio of active fraction in Rhizoma et Radix Ligustici, so it is reasonable and practicable.

  11. [Study on supercritical CO2 extraction of flavonoids from Cynomorium songaricum].

    Science.gov (United States)

    Luan, Na; Li, Di

    2010-07-01

    To study the extraction technology of flavonoids from Cynomorium songaricum by supercritical CO2 extraction. The effects of pressure, temperature, time, concentration of alcohol, dosage of chemical preparation, flux of CO2 and particle size were studied by single factor analysis and orthogonal test. The optimized conditions were as follows: particle size 60 - 80 sieve mesh, the pressure was 30 MPa, the temperature was 50 degrees C, the time was 75 min, concentration of alcohol was 50%, entrainment rate was 8%, flux of CO2 was 5 mL/min. The total flavonoids yield could reach 21.18% under the above conditions. This method is simple, rapid and higher extraction yield, so it is suitable for the extraction of flavonoids from Cynomorium songaricum.

  12. Design of experimental setup for supercritical CO2 jet under high ambient pressure conditions.

    Science.gov (United States)

    Shi, Huaizhong; Li, Gensheng; He, Zhenguo; Wang, Haizhu; Zhang, Shikun

    2016-12-01

    With the commercial extraction of hydrocarbons in shale and tight reservoirs, efficient methods are needed to accelerate developing process. Supercritical CO2 (SC-CO2) jet has been considered as a potential way due to its unique fluid properties. In this article, a new setup is designed for laboratory experiment to research the SC-CO2 jet's characteristics in different jet temperatures, pressures, standoff distances, ambient pressures, etc. The setup is composed of five modules, including SC-CO2 generation system, pure SC-CO2 jet system, abrasive SC-CO2 jet system, CO2 recovery system, and data acquisition system. Now, a series of rock perforating (or case cutting) experiments have been successfully conducted using the setup about pure and abrasive SC-CO2 jet, and the results have proven the great perforating efficiency of SC-CO2 jet and the applications of this setup.

  13. A Conceptual Study of a Supercritical CO2-Cooled Micro Modular Reactor

    Directory of Open Access Journals (Sweden)

    Hwanyeal Yu

    2015-12-01

    Full Text Available A neutronics conceptual study of a supercritical CO2-cooled micro modular reactor (MMR has been performed in this work. The suggested MMR is an extremely compact and truck-transportable nuclear reactor. The thermal power of the MMR is 36.2 MWth and it is designed to have a 20-year lifetime without refueling. A salient feature of the MMR is that all the components including the generator are integrated in a small reactor vessel. For a minimal volume and long lifetime of the MMR core, a fast neutron spectrum is utilized in this work. To enhance neutron economy and maximize the fuel volume fraction in the core, a high-density uranium mono-nitride U15N fuel is used in the fast-spectrum MMR. Unlike the conventional supercritical CO2-cooled fast reactors, a replaceable fixed absorber (RFA is introduced in a unique way to minimize the excess reactivity and the power peaking factor of the core. For a compact core design, the drum-type control absorber is adopted as the primary reactivity control mechanism. In this study, the neutronics analyses and depletions have been performed by using the continuous energy Monte Carlo Serpent code with the evaluated nuclear data file ENDF/B-VII.1 Library. The MMR core is characterized in view of several important safety parameters such as control system worth, fuel temperature coefficient (FTC and coolant void reactivity (CVR, etc. In addition, a preliminary thermal-hydraulic analysis has also been performed for the hottest channel of the Korea Advanced Institute of Science and Technology (KAIST MMR.

  14. Microfluidic study for investigating migration and residual phenomena of supercritical CO2 in porous media

    Science.gov (United States)

    Park, Gyuryeong; Wang, Sookyun; Lee, Minhee; Um, Jeong-Gi; Kim, Seon-Ok

    2017-04-01

    The storage of CO2 in underground geological formation such as deep saline aquifers or depleted oil and gas reservoirs is one of the most promising technologies for reducing the atmospheric CO2 release. The processes in geological CO2 storage involves injection of supercritical CO2 (scCO2) into porous formations saturated with brine and initiates CO2 flooding with immiscible displacement. The CO2 migration and porewater displacement within geological formations, and , consequentially, the storage efficiency are governed by the interaction of fluid and rock properties and are affected by the interfacial tension, capillarity, and wettability in supercritical CO2-brine-mineral systems. This study aims to observe the displacement pattern and estimate storage efficiency by using micromodels. This study aims to conduct scCO2 injection experiments for visualization of distribution of injected scCO2 and residual porewater in transparent pore networks on microfluidic chips under high pressure and high temperature conditions. In order to quantitatively analyze the porewater displacement by scCO2 injection under geological CO2 storage conditions, the images of invasion patterns and distribution of CO2 in the pore network are acquired through a imaging system with a microscope. The results from image analysis were applied in quantitatively investigating the effects of major environmental factors and scCO2 injection methods on porewater displacement process by scCO2 and storage efficiency. The experimental observation results could provide important fundamental information on capillary characteristics of reservoirs and improve our understanding of CO2 sequestration progress.

  15. New Class of Amphiphiles Designed for Use in Water-in-Supercritical CO2 Microemulsions.

    Science.gov (United States)

    Sagisaka, Masanobu; Ogiwara, Shunsuke; Ono, Shinji; James, Craig; Yoshizawa, Atsushi; Mohamed, Azmi; Rogers, Sarah E; Heenan, Richard K; Yan, Ci; Peach, Jocelyn Alice; Eastoe, Julian

    2016-11-29

    Water-in-supercritical CO2 microemulsions formed using the hybrid F-H surfactant sodium 1-oxo-1-[4-(perfluorohexyl)phenyl]hexane-2-sulfonate, FC6-HC4, have recently been shown to have the highest water-solubilizing power ever reported. FC6-HC4 demonstrated the ability to outperform not only other surfactants but also other FCm-HCn analogues containing different fluorocarbon and hydrocarbon chain lengths (Sagisaka, M. et al. Langmuir 2015, 31, 7479-7487). With the aim of clarifying the key structural features of this surfactant, this study examined the phase behavior and water/supercritical CO2 aggregate formation of 1-oxo-1-[4-(perfluorohexyl)phenyl]hexane (Nohead FC6-HC4), which is an FC6-HC4 analogue but now, interestingly, without the sulfonate headgroup. Surprisingly, Nohead FC6-HC4, which would not normally be identified as a classic surfactant, yielded transparent single-phase W/CO2 microemulsions with polar cores able to solubilize a water-soluble dye, even at pressures and temperatures so low as to approach the critical point of CO2 (e.g., ∼100 bar at 35 °C). High-pressure small-angle scattering (SANS) measurements revealed the transparent phases to consist of ellipsoidal nanodroplets of water. The morphology of these droplets was shown to be dependent on the pressure, Nohead FC6-HC4 concentration, and water-to-surfactant molar ratio. Despite having almost the same structure as Nohead FC6-HC4, analogues containing both shorter and longer hydrocarbons were unable to form W/CO2 microemulsion droplets. This shows the importance of the role of the hydrocarbon chain in the stabilization of W/CO2 microemulsions. A detailed examination of the mechanism of Nohead FC6-HC4 adsorption onto the water surface suggests that the hexanoyl group protrudes into the aqueous core, allowing for association between the carbonyl group and water.

  16. Modeling of mass transfer of Phospholipids in separation process with supercritical CO2 fluid by RBF artificial neural networks

    Science.gov (United States)

    An artificial Radial Basis Function (RBF) neural network model was developed for the prediction of mass transfer of the phospholipids from canola meal in supercritical CO2 fluid. The RBF kind of artificial neural networks (ANN) with orthogonal least squares (OLS) learning algorithm were used for mod...

  17. Drug-polymer filled micro-containers for oral delivery loaded using supercritical CO2 aided-impregnation

    DEFF Research Database (Denmark)

    Marizza, Paolo; Keller, Stephan Sylvest; Rades, T.

    2013-01-01

    In this work we present an effective loading technique of micro-containers for oral drug delivery of a poorly water soluble drug in a solid dispersion with polymer. By combining inkjet printing and supercritical CO2 impregnation we load ketoprofen in a solid dispersion with poly...

  18. Effect of supercritical CO2 on the morphology and fluorescent behavior of fluorinated polyylidenefluorenes derivative/graphene oxide nanohybrids

    NARCIS (Netherlands)

    Li, Jing; Zheng, Shijun; Wang, Xiaobo; Yang, Hongxia; Loos, Katja; Xu, Qun

    2015-01-01

    Fluorinated polyylidenefluorenes derivative, poly [(9-ylidene-{2-tetradecyloxy-5-tetrafluorophthalimide-phenyl}fluorenyl-2,7-diyl)-alt-(1,4-phenyl)] (PFFB)/graphene oxide (GO) nanohybrids (SC-PFFB/GO) were successfully fabricated via a facile method with the assistance of supercritical CO2 (SC CO2).

  19. Experimental Determination and Modeling of the Phase Behavior for the Selective Oxidation of Benzyl Alcohol in Supercritical CO2

    DEFF Research Database (Denmark)

    Tsivintzelis, Ioannis; Beier, Matthias Josef; Grunwaldt, Jan-Dierk

    2011-01-01

    In this study the phase behavior of mixtures relevant to the selective catalytic oxidation of benzyl alcohol to benzaldehyde by molecular oxygen in supercritical CO2 is investigated. Initially, the solubility of N2 in benzaldehyde as well as the dew points of CO2–benzyl alcohol–O2 and CO2...

  20. Effect of supercritical CO2 on the morphology and fluorescent behavior of fluorinated polyylidenefluorenes derivative/graphene oxide nanohybrids

    NARCIS (Netherlands)

    Li, Jing; Zheng, Shijun; Wang, Xiaobo; Yang, Hongxia; Loos, Katja; Xu, Qun

    2015-01-01

    Fluorinated polyylidenefluorenes derivative, poly [(9-ylidene-{2-tetradecyloxy-5-tetrafluorophthalimide-phenyl}fluorenyl-2,7-diyl)-alt-(1,4-phenyl)] (PFFB)/graphene oxide (GO) nanohybrids (SC-PFFB/GO) were successfully fabricated via a facile method with the assistance of supercritical CO2 (SC CO2).

  1. HYDROGENATION OF 4-OXOISOPHORONE OVER PD/AL2/O2 CATALYST UNDER SUPERCRITICAL CO2 MEDIUM

    Science.gov (United States)

    Hydrogenation of 4-oxoisophorone has been studied over 1% Pd/Al2O3 impregnated catalyst in supercritical CO2 medium at different reaction conditions. The effect of temperature, pressure and reaction medium on the conversion and product selectivity is discussed. Phase behavior stu...

  2. [Optimization for supercritical CO2 extraction with response surface methodology and component analysis of Sapindus mukorossi oil].

    Science.gov (United States)

    Wu, Yan; Xiao, Xin-yu; Ge, Fa-huan

    2012-02-01

    To study the extraction conditions of Sapindus mukorossi oil by Supercritical CO2 Extraction and identify its components. Optimized SFE-CO2 Extraction by response surface methodology and used GC-MS to analysie Sapindus mukorossi oil compounds. Established the model of an equation for the extraction rate of Sapindus mukorossi oil by Supercritical CO2 Extraction, and the optimal parameters for the Supercritical CO2 Extraction determined by the equation were: the extraction pressure was 30 MPa, temperature was 40 degrees C; The separation I pressure was 14 MPa, temperature was 45 degrees C; The separation II pressure was 6 MPa, temperature was 40 degrees C; The extraction time was 60 min and the extraction rate of Sapindus mukorossi oil of 17.58%. 22 main compounds of Sapindus mukorossi oil extracted by supercritical CO2 were identified by GC-MS, unsaturated fatty acids were 86.59%. This process is reliable, safe and with simple operation, and can be used for the extraction of Sapindus mukorossi oil.

  3. Effect of combined treatment with supercritical CO2 and rosemary on microbiological and physicochemical properties of ground pork stored at 4°C.

    Science.gov (United States)

    Huang, Shirong; Liu, Bin; Ge, Du; Dai, Jiehui

    2017-03-01

    The effect of combined treatment with supercritical CO2 (2000psi, 35°C for 2h) and rosemary powder (2.5% and 5.0% (w/w)) on microbiological and physicochemical properties of ground pork stored at 4°C was investigated. The changes in total viable count, pH, total volatile base nitrogen (TVB-N), lipid oxidation and instrumental color (CIE L(⁎), a(⁎), b(⁎)) were analyzed during a week period of refrigerated storage. It was found that microbial populations were reduced by supercritical CO2 treatment, with the more pronounced effect being achieved by combined treatment with supercritical CO2 and 5.0g rosemary powder/100g meat. Supercritical CO2 treatment for 2h could accelerate lipid oxidation of ground pork during refrigerated storage, whereas combination with rosemary can significantly slow down the increase of oxidation rate. Combined treatment of supercritical CO2 and rosemary significantly increased L(⁎) and b(⁎) values of the ground pork, while the a(⁎), pH and TVB-N value were not affected as compared to the treatment with supercritical CO2 alone. The results of this study indicate that combined treatment of supercritical CO2 and rosemary may be useful in the meat industry to enhance the storage stability of ground pork treated with long time exposure of supercritical CO2 during refrigerated storage.

  4. Phytochemical profile, antioxidant and antimicrobial activity of extracts obtained from erva-mate (Ilex paraguariensis) fruit using compressed propane and supercritical CO2.

    Science.gov (United States)

    Fernandes, Ciro E F; Scapinello, Jaqueline; Bohn, Aline; Boligon, Aline A; Athayde, Margareth L; Magro, Jacir Dall; Palliga, Marshall; Oliveira, J Vladimir; Tres, Marcus V

    2017-01-01

    Traditionally, Ilex paraguariensis leaves are consumed in tea form or as typical drinks like mate and terere, while the fruits are discarded processing and has no commercial value. The aim of this work to evaluate phytochemical properties, total phenolic compounds, antioxidant and antimicrobial activity of extracts of Ilex paraguariensis fruits obtained from supercritical CO2 and compressed propane extraction. The extraction with compressed propane yielded 2.72 wt%, whereas with supercritical CO2 1.51 wt% was obtained. The compound extracted in larger amount by the two extraction solvents was caffeine, 163.28 and 54.17 mg/g by supercritical CO2 and pressurized propane, respectively. The antioxidant activity was more pronounced for the supercritical CO2 extract, with no difference found in terms of minimum inhibitory concentration for Staphylococcus aureus for the two extracts and better results observed for Escherichia coli when using supercritical CO2.

  5. Insights into Silicate Carbonation Processes in Water-Bearing Supercritical CO2 Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Quin RS; Thompson, Christopher J.; Loring, John S.; Windisch, Charles F.; Bowden, Mark E.; Hoyt, David W.; Hu, Jian Z.; Arey, Bruce W.; Rosso, Kevin M.; Schaef, Herbert T.

    2013-07-01

    Long-term geologic storage of carbon dioxide (CO2) is considered an integral part to moderating CO2 concentrations in the atmosphere and subsequently minimizing effects of global climate change. Although subsurface injection of CO2 is common place in certain industries, deployment at the scale required for emission reduction is unprecedented and therefore requires a high degree of predictability. Accurately modeling geochemical processes in the subsurface requires experimental derived data for mineral reactions occurring between the CO2, water, and rocks. Most work in this area has focused on aqueous-dominated systems in which dissolved CO2 reacts to form crystalline carbonate minerals. Comparatively little laboratory research has been conducted on reactions occurring between minerals in the host rock and the wet supercritical fluid phase. In this work, we studied the carbonation of wollastonite [CaSiO3] exposed to variably hydrated supercritical CO2 (scCO2) at a range of temperatures (50, 55 and 70 °C) and pressures (90,120 and 160 bar) that simulate conditions in geologic repositories. Mineral transformation reactions were followed by three novel in situ high pressure techniques, including x-ray diffraction that tracked the rate and extents of wollastonite conversion to calcite. Increased dissolved water concentrations in the supercritical CO2 resulted in increased silicate carbonation approaching ~50 wt. %. Development of thin water films on the mineral surface were directly observed with infrared spectroscopy and determined to be critical for facilitating carbonation processes. Even in extreme low water conditions, magic angle spinning nuclear magnetic resonance detected formation of Q3 [Si(OSi)3OH] and Q4 [Si(OSi)4] amorphous silica species. Unlike the thick (<10 μm) passivating silica layers observed in the fully water saturated scCO2 experiments, images obtained from a focused ion beam sectioned sample indicted these coatings were chemically wollastonite

  6. Plant Growth Biostimulants, Dietary Feed Supplements and Cosmetics Formulated with Supercritical CO2 Algal Extracts

    Directory of Open Access Journals (Sweden)

    Izabela Michalak

    2017-01-01

    Full Text Available The review paper presents the use of algal extracts as safe and solvent-free components of plant growth biostimulants, dietary feed additives and cosmetics. Innovative technology that uses extracts obtained by supercritical CO2 extraction, as a method of isolation of biologically active compounds from algal biomass, is presented. An important part of the complete technology is the final formulation of the product. This enabled realization of the further step which was assessment of the utilitarian properties of the extract-based products. The extracts were analysed for the presence of biologically active molecules (e.g., plant hormones, polyphenols which provide useful properties such as antioxidant, antiviral, anti-inflammatory and antibacterial. The bio-products were tested in germination tests and underwent field trials to search for plant growth biostimulatory properties. Tests on animals (laying hens experiments were conducted to assess pro-health properties of new dietary feed supplement. Another application were cosmetic formulations (dermatological tests. The results of the application tests were very promising, however further studies are required for the registration of the products and successful implementation to the market.

  7. Inactivation of Staphylococcus aureus in raw salmon with supercritical CO2 using experimental design

    Directory of Open Access Journals (Sweden)

    Mônica CUPPINI

    2016-01-01

    Full Text Available Abstract Considering the microbial safety of consumption of raw foods (Asian food, this study aimed to explore the inactivation S. aureus in raw salmon by supercritical CO2 treatment (SC-CO2. For this purpose, experimental design methodology was employed as a tool to evaluate the effects of pressure (120-220 bar, the depressurization rate (10 to 100 bar.min–1 and the salmon:CO2 mass relation (1:0.2 to 1:1.0. It was observed that the pressure and the depressurization rate was statistically significant, i.e. the higher the system pressure and depressurization rate, the greater the microbial inactivation. The salmon: CO2 mass relation did not influence the S. aureus inactivation in raw salmon. There was a total reduction in S. aureus with 225 bar, a depressurizing rate of 100 bar.min–1, a salmon: CO2 mass relation of 1:0.6, for 2 hours at 33 °C.

  8. Supercritical CO2 Foaming of Radiation Cross-Linked Isotactic Polypropylene in the Presence of TAIC

    Directory of Open Access Journals (Sweden)

    Chen-Guang Yang

    2016-12-01

    Full Text Available Since the maximum foaming temperature window is only about 4 °C for supercritical CO2 (scCO2 foaming of pristine polypropylene, it is important to raise the melt strength of polypropylene in order to more easily achieve scCO2 foaming. In this work, radiation cross-linked isotactic polypropylene, assisted by the addition of a polyfunctional monomer (triallylisocyanurate, TAIC, was employed in the scCO2 foaming process in order to understand the benefits of radiation cross-linking. Due to significantly enhanced melt strength and the decreased degree of crystallinity caused by cross-linking, the scCO2 foaming behavior of polypropylene was dramatically changed. The cell size distribution, cell diameter, cell density, volume expansion ratio, and foaming rate of radiation-cross-linked polypropylene under different foaming conditions were analyzed and compared. It was found that radiation cross-linking favors the foamability and formation of well-defined cell structures. The optimal absorbed dose with the addition of 2 wt % TAIC was 30 kGy. Additionally, the foaming temperature window was expanded to about 8 °C, making the handling of scCO2 foaming of isotactic polypropylene much easier.

  9. Atomic Layer Deposition of High-k Dielectrics Using Supercritical CO2

    Science.gov (United States)

    Shende, Rajesh

    2005-03-01

    Atomic layer deposition (ALD) of high-κdielectric was performed in supercritical CO2 (SCCO2), using a two-step reaction sequence. In step one, tetraethoxy silane (TEOS) precursor was injected in SCCO2 at 80-100 C and 50 MPa pressure to obtain a chemisorbed surface monolayer, which was then oxidized into SiO2 using peroxide entrained in SCCO2. ALD process was controlled by estimating precursor solubility and its mass transport with respect to the density of SCCO2, and correlating these parameters with precursor injection volume. In the ALD process, 7 pulses of precursor were used anticipating deposition of one atomic layer in each of the pulses. The thickness of the SiO2 atomic layers deposited using SCCO2 was measured by variable angle spectroscopic ellipsometry (VASE), and the C-V measurements were also performed. The result obtained using VASE indicates that there were 7 monolayers of SiO2 with total thickness of 35 å, and the dielectric constant of the deposited layers was 4.0±0.1. Our initial findings clearly demonstrate that SCCO2 is capable of atomic layer deposition of high quality dielectric films at very low process temperatures preventing interface reaction. More research is in progress to achieve ALD of HfO2 and TiO2 in SCCO2.

  10. Features of the supercritical CO2-assisted immobilization of fluorinated tetraphenylporphyrins into tetrafluoroethylene copolymers

    Science.gov (United States)

    Shershnev, I. V.; Cherkasova, A. V.; Kopylov, A. S.; Glagolev, N. N.; Bragina, N. A.; Solov'eva, A. B.

    2017-07-01

    The immobilization of fluorinated tetraphenylporphyrins (FTPPs) into tetrafluoroethylene copolymers (fluoroplast F-42 and MF-4SK, a perfluorinated sulfonic acid cation exchanger in H+-form) is conducted in supercritical CO2 (scCO2). The effects the conditions of immobilization (the temperature and pressure of scCO2, reaction time, and the addition of cosolvents) and the structure of the carrier polymer have on the content of porphyrin in these polymers is studied. The porphyrin-loaded polymer systems are shown to exhibit photosensitizing activity in anthracene and cholesterol oxidation in scCO2. Under conditions of photocatalysis, chemical and functional stability is a feature of only MF-4SK polymer systems; this is attributed to the formation of protonated forms of the porphyrins and their interaction with SO3 --groups of the polymer (an ion exchange process), which prevents leaching of the FTPP from the polymer matrix. The photocatalytic process actually occurs inside the matrix of the perfluorinated copolymer, with the protonated form of the porphyrin acting as a photosensitizer. The rate constant of anthracene photooxidation in the presence of FTPP-loaded MF-4SK films in scCO2 is found to pass through a maximum as a function of the porphyrin content and the polymer film thickness. The use of such catalytic systems for cholesterol photooxidation in scCO2 is shown to produce a virtual monoproduct (yield, 10%): 6-formyl-B-norcholestane-3,5-diol, a compound with high biological activity.

  11. Extraction of oil and minor lipids from cold-press rapeseed cake with supercritical CO2

    Directory of Open Access Journals (Sweden)

    E. Uquiche

    2012-09-01

    Full Text Available This study examines the extraction of oil from cold-press rapeseed cake using Supercritical CO2(SC-CO2. The effects of pressure (20, 30, and 40 MPa, temperature (40, 50, and 60 ºC, and extraction time (60, 90, and 120 min on oil yield and composition (tocopherols and carotenoids were studied using response surface design. The results indicated that pressure influenced the most the yield of oil, followed by temperature and extraction time. Extraction time had no effect on oil composition. Extraction pressure and temperature did not affect the tocopherol concentration of the oil to a great extent, whereas temperature had no affect in its carotenoid concentration. A comparison was made between the relative qualities of oil extracted with SC-CO2at 40 MPa and 60 ºC and with n-hexane. Neither solvent affected the unsaponifiable matter content or the composition of phytosterols (mainly β-sitosterol, campesterol and brassicasterol of the oils, although there was a significant difference (p<0.05 in tocopherol. Extraction with SC-CO2at 40 MPa and 60 ºC is recommended to obtain rapeseed-oil enriched with tocopherols and carotenoids as important functional components.

  12. Capillary pressure heterogeneity and hysteresis for the supercritical CO2/water system in a sandstone

    Science.gov (United States)

    Pini, Ronny; Benson, Sally M.

    2017-10-01

    We report results from an experimental investigation on the hysteretic behaviour of the capillary pressure curve for the supercritical CO2-water system in a Berea Sandstone core. Previous observations have highlighted the importance of subcore-scale capillary heterogeneity in developing local saturations during drainage; we show in this study that the same is true for the imbibition process. Spatially distributed drainage and imbibition scanning curves were obtained for mm-scale subsets of the rock sample non-invasively using X-ray CT imagery. Core- and subcore-scale measurements are well described using the Brooks-Corey formalism, which uses a linear trapping model to compute mobile saturations during imbibition. Capillary scaling yields two separate universal drainage and imbibition curves that are representative of the full subcore-scale data set. This enables accurate parameterisation of rock properties at the subcore-scale in terms of capillary scaling factors and permeability, which in turn serve as effective indicators of heterogeneity at the same scale even when hysteresis is a factor. As such, the proposed core-analysis workflow is quite general and provides the required information to populate numerical models that can be used to extend core-flooding experiments to conditions prevalent in the subsurface, which would be otherwise not attainable in the laboratory.

  13. Effects of Supercritical CO 2 Conditioning on Cross-Linked Polyimide Membranes

    KAUST Repository

    Kratochvil, Adam M.

    2010-05-25

    The effects of supercritical CO2 (scCO2) conditioning on high-performance cross-linked polyimide membranes is examined through gas permeation and sorption experiments. Under supercritical conditions, the cross-linked polymers do not exhibit a structural reorganization of the polymer matrix that was observed in the non-cross-linkable, free acid polymer. Pure gas permeation isotherms and mixed gas permeabilities and selectivities show the cross-linked polymers to be much more stable to scCO2 conditioning than the free acid polymer. In fact, following scCO2 conditioning, the mixed gas CO2 permeabilities of the cross-linked polymers increased while the CO2/CH4 separation factors remained relatively unchanged. This response highlights the stability and high performance of these cross-linked membranes in aggressive environments. In addition, this response reveals the potential for the preconditioning of cross-linked polymer membranes to enhance productivity without sacrificing efficiency in practical applications which, in effect, provides another tool to \\'tune\\' membrane properties for a given separation. Finally, the dual mode model accurately describes the sorption and dilation characteristics of the cross-linked polymers. The changes in the dual mode sorption model parameters before and after the scCO2 exposure also provide insights into the alterations in the different glassy samples due to the cross-linking and scCO2 exposure. © 2010 American Chemical Society.

  14. Effect of matrix pretreatment on the supercritical CO2 extraction of Satureja montana essential oil

    Directory of Open Access Journals (Sweden)

    Damjanović-Vratnica Biljana

    2016-01-01

    Full Text Available The effect of different matrix pretreatment of winter savory(Satureja montana L. on the supercritical CO2(SC-CO2 extraction - yield, composition and antimicrobial activity of extracts and essential oil (EO was investigated. Herb matrix was submitted to conventional mechanical grinding, physical disruption by fast decompression of supercritical and subcritical CO2 and physical disruption by mechanical compression. The analyses of the essential oil obtained by SC-CO2 extraction and hydrodistillation were done by GC/FID method. Major compounds in winter savory EO obtained by SC-CO2 extraction and hydrodistillation were: thymol (30.4-35.4% and 35.3%, carvacrol (11.5-14.1% and 14.1%, γ-terpinene (10.2-11.4% and 9.1% and p-cymene (8.3-10.1% and 8.6%, respectively. The gained results revealed that physical disruption of essential oils glands by fast CO2 decompression in supercritical region (FDS achieved the highest essential oil yield as well as highest content of thymol, carvacrol and thymoquinone. Antimicrobial activity of obtained winter savory SC-CO2 extracts was the same (FDS or weaker compared to essential oil obtained by hydrodistillation.

  15. Genotoxicity of rice bran oil extracted by supercritical CO2 extraction.

    Science.gov (United States)

    Choi, Jae-Suk; Cheon, Eun Jin; Kim, Tae-Uk; Moon, Woi-Sook; Kim, Joo-Wan; Kim, Mi-Ryung

    2014-01-01

    Rice bran oil extracted by supercritical CO2 extraction (RB-SCE) reportedly exhibits pharmacological activities such as antioxidant and in vivo hair growth-inducing effects. Such activities raise the possibility of the development of novel hair growth-inducing agents using RB-SCE. The aim of this study was to investigate the potential genotoxic effects of RB-SCE in three short-term mutagenicity assays (bacterial reverse mutation assay, in vitro mammalian chromosomal aberration test, and in vivo micronucleus assay). RB-SCE showed no genotoxicity in the bacterial reverse mutation assay up to 5000 mg/plate and in the in vivo micronucleus test up to 600 mg/kg body weight. However, at 120 µg/mL with S9 mix and 200 µg/mL without S9 mix RB-SCE showed significantly different genotoxicity than the negative control in the in vitro chromosome aberration test. The induction of chromosomal aberrations under the present conditions may have no biological significance. We have herein demonstrated that RB-SCE can be regarded as a non-genotoxic material based on the available in vivo and in vitro results.

  16. [Harmful elements removal from Polygonum multiflorum by supercritical CO2 extraction].

    Science.gov (United States)

    Wen, Zhen; Liu, Bo; Zheng, Zong-Kun; You, Xin-Kui; Pu, Yi-Tao; Dang, Zhi

    2008-10-01

    To remove harmful elements as copper, lead and arsenic from Polygonum multiflorum, a Chinese traditional medicine, by supercritical carbon dioxide extraction. With sodium diethyldithiocarbamate (NaDDC) as a chelating agent and ethanol as a modifier, the effects of extraction style, time, pressure, temperature and amount of chelating agent on chelating extraction process were discussed. The condition was optimized as following: 28 MP as extraction pressure, 60 degrees C as extraction temperature, 1 h as static extraction time, 2 h as dynamic extraction time, m(herb) : m(NaDDC) = 5 : 1, m(herb) : m(ethanol) = 1 : 1. Under this condition, the extraction rate of Cu, Pb and As were up to 60% which achieved US FDA standard, while the physioloically active substance of 2,3,5,4'-tetrahydroxy-silbene-2-O-beta-D-glucoside was not extracted. The results show chelating extraction by supercritical CO2 can provide a non-destructive method to decrease the content of harmful elements from Chinese traditional medicines.

  17. Supercritical CO2 extraction of lipids from grain sorghum dried distillers grains with solubles.

    Science.gov (United States)

    Wang, Lijun; Weller, Curtis L; Schlegel, Vicki L; Carr, Timothy P; Cuppett, Susan L

    2008-03-01

    Experiments were carried out on a lab supercritical CO(2) extraction system to determine the effects of extraction conditions, including mass ratio of CO(2) consumed to distillers dry grain with solubles (DDGS) extracted, extraction pressure, extraction temperature and time, on yield and composition of extracted lipids. A maximum lipid yield of 150 g/kg DDGS was achieved with a mass ratio approximately 45, an extraction pressure at 27.5 MPa, an extraction temperature at 70 degrees C and an extraction time of 4 h. Under these extraction conditions, the contents of tocols, phytosterols, policosanols and free fatty acids were 0.44, 15.6, 31.2 and 155.3 mg/g in the extract. Experimental results indicated that shorter extraction time and higher flow rate of CO(2) can achieve higher contents of tocols, phytosterols and policosanols but lower content of free fatty acids in the lipid extract. Extraction conditions had no observed effects on the composition of free fatty acids in the extract. Palmitic, oleic and linoleic acids were three main free fatty acids extracted and constituted about 94% of all free fatty acids.

  18. The Role of H2O in the Carbonation of Forsterite in Supercritical CO2

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Ja Hun; Hu, Jian Z.; Turcu, Romulus VF; Rosso, Kevin M.; Ilton, Eugene S.; Wang, Chong M.; Sears, Jesse A.; Engelhard, Mark H.; Felmy, Andrew R.; Hoyt, David W.

    2011-07-01

    The water concentration dependence of forsterite carbonation in supercritical CO2 (scCO2) at 80°C and 76 bars was investigated by a combination of NMR, XRD, TEM and XPS. Reaction products were not detected using scCO2 alone without added H2O. When trace amounts of water were included, limited reaction was observed. Below saturation, reaction products were a mixture of partially hydrated/hydroxylated magnesium carbonates and hydroxylated silica species that were mainly in an amorphous state, forming a non-resolved layer on the forsterite surface. At water concentrations above saturation, where forsterite was in contact with both a CO2-saturated aqueous fluid and a water-saturated scCO2 fluid, solid reaction products were magnesite (MgCO3) and an amorphous polymerized SiO2 dominated by Q4, and to a lesser extent by Q3 silica coordination. Formation of these phases implies H2O initially bound in precursor hydrated/hydroxylated reaction products was liberated, inducing further reaction. Hence, for a given fluid/mineral ratio there is a water threshold above which a significant portion of the water serves in a catalytic role where more extensive carbonation reaction occurs. Defining the role of water, even in low water content environments, is therefore critical to determining the long term impact of CO2 reactivity in the subsurface.

  19. Formation of Magnesite at Low Temperature in Mineral:Supercritical CO2 Systems

    Science.gov (United States)

    Qafoku, O.; Hu, J.; Arey, B.; Liu, J.; Ilton, E. S.; Felmy, A.

    2013-12-01

    One of the most promising options for mitigating the impacts of greenhouse gases on global warming is storage and sequestration of the anthropogenic CO2 in deep geologic formations. Consequently, evaluating mineral-fluid interaction in aqueous systems saturated with supercritical CO2 (scCO2) has been the focus for subsurface CO2 storage research. An important factor in assessing mineral-fluid interactions is the potential for the formation of stable divalent metal carbonates, principally Ca and Mg, which can immobilize the disposed CO2 as mineral precipitates. The formation of some of these phases, especially the Mg anhydrous phase magnesite (MgCO3), has been hindered by slow precipitation kinetics owing to the strong affinity of Mg2+ ion for the waters of hydration. Understanding conditions that lead to formation of magnesite at temperatures significant to subsurface disposal of CO2 can be substantial in the development of efficient carbon sequestration techniques. Here we present recently obtained experimental data on the formation of magnesite at low temperature (as low as 350C) and microscopy data that can elucidate factors that might contribute to magnesite formation. The experimental studies were conducted over a range of temperature, pressure, pH, and initial Mg(HCO3)2 concentration to map out the specific solution phase conditions which result in nucleation of magnesite in aqueous solution saturated with scCO2.

  20. Micronization of Griseofulvin by Ress in Supercritical CO2 with Cosolvent Acetone

    Institute of Scientific and Technical Information of China (English)

    胡国勤; 陈鸿雁; 蔡建国; 邓修

    2003-01-01

    Griseofulvin (GF) is an antifungal drug whose pharmaceutical activity can be improved by reducing particle size. In this study the rapid expansion of supercritical solution (RESS) was employed to micronize GF.Carbon dioxide with cosolvent acetone was chosen as a supercritical mixed solvent. The solubility of GF in super-critical CO2 with cosolvent acetone was measured using a dynamic apparatus at pressures between 12 and 32 MPa,temperatures at 313, 323 and 333 K and cosolvent concentration at 1.5, 3.0, 4.5 and 6.0% (by mole). The effect of pre-expansion pressure, extraction temperature, spraying distance, nozzle size and concentration of cosolvent on the precipitated particles was investigated. The results show that the mean particle size of griseofulvin precipitated by RESS was less than 1.2μm. An increase in pre-expansion pressure, extraction temperature, spraying distance and concentration of cosolvent resulted in a decrease in particle size under the operating condition studied. With the decrease of nozzle diameter the particle size reduces. The crystallinity and melting point of the original material and the processed particle by RESS were tested by X-ray diffraction (XRD) and differential scanning calorimetry (DSC).No evident modification in the crystal habit was found under the experimental conditions tested. The morphology of particles precipitated was analyzed bY scanning electron microscopy (SEM).

  1. Significant improvement of thermal stability for CeZrPrNd oxides simply by supercritical CO(2 drying.

    Directory of Open Access Journals (Sweden)

    Yunzhao Fan

    Full Text Available Pr and Nd co-doped Ce-Zr oxide solid solutions (CZPN were prepared using co-precipitation and microemulsion methods. It is found that only using supercritical CO(2 drying can result in a significant improvement of specific surface area and oxygen storage capacity at lower temperatures for CZPN after aging at 1000°C for 12 h in comparison with those using conventional air drying and even supercritical ethanol drying. Furthermore, the cubic structure was obtained in spite of the fact that the atomic ratio of Ce/(Ce+Zr+Pr+Nd is as low as 29%. The high thermal stability can be attributed to the loosely aggregated morphology and the resultant Ce enrichment on the nanoparticle surface, which are caused by supercritical CO(2 drying due to the elimination of surface tension effects on the gas-liquid interface.

  2. Effect of Co-solvent and Pressure on the Thermal Decomposition of 2, 2' Azobis - (isobutyronitrile) in Supercritical CO2

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The thermal decomposition of 2, 2'-azobis (isobutyronitrile) (AIBN) in supercritical CO2 with cosolvent methanol or cyclohexane has been studied by using UV/Vis spectroscopic method at 335.15 K and at 12.0 MPa and 14.0 MPa. Both of the cosolvents can accelerate the decomposition rate, and the effect of methanol is more significant than that of the cyclohexane.

  3. Endogenous, Imperfectly Competitive Business Cycles

    DEFF Research Database (Denmark)

    Whitta-Jacobsen, Hans Jørgen

    by monopolistic competition. An implicit assumption of barriers to entry justifies that the number of firms is fixed even when positive profits occur. It turns out that both market power of firms on the product markets and market power of unions on the labor markets make the occurrence of cycles more likely......We investigate how imperfect competition affects the occurrence and the properties of endogenous, rational expectations business cycles in an overlapping generations model with constant returns to scale in production. The model has explicit product and labor markets all characterized....... In particular, imperfect competition on the product markets and the positive profits associated with it may have the effect that there is a cycle even if the labor supply curve is increasing in the real-wage rate. For competitive cycles is required not only a decreasing labor supply curve, but a wage elasticity...

  4. Research on the physical properties of supercritical CO2 and the log evaluation of CO2-bearing volcanic reservoirs

    Science.gov (United States)

    Pan, Baozhi; Lei, Jian; Zhang, Lihua; Guo, Yuhang

    2017-10-01

    CO2-bearing reservoirs are difficult to distinguish from other natural gas reservoirs during gas explorations. Due to the lack of physical parameters for supercritical CO2, particularly neutron porosity, at present a hydrocarbon gas log evaluation method is used to evaluate CO2-bearing reservoirs. The differences in the physical properties of hydrocarbon and CO2 gases have led to serious errors. In this study, the deep volcanic rock of the Songliao Basin was the research area. In accordance with the relationship between the density and acoustic velocity of supercritical CO2 and temperature and pressure, the regularity between the CO2 density and acoustic velocity, and the depth of the area was established. A neutron logging simulation was completed based on a Monte Carlo method. Through the simulation of the wet limestone neutron logging, the relationship between the count rate ratio of short and long space detectors and the neutron porosity was acquired. Then, the nature of the supercritical CO2 neutron moderation was obtained. With consideration given to the complexity of the volcanic rock mineral composition, a volcanic rock volume model was established, and the matrix neutron and density parameters were acquired using the ECS log. The properties of CO2 were applied in the log evaluation of the CO2-bearing volcanic reservoirs in the southern Songliao Basin. The porosity and saturation of CO2 were obtained, and a reasonable application was achieved in the CO2-bearing reservoir.

  5. Supercritical CO2 Cleaning System for Planetary Protection and Contamination Control Applications

    Science.gov (United States)

    Lin, Ying; Zhong, Fang; Aveline, David C.; Anderson, Mark S.

    2012-01-01

    Current spacecraft-compatible cleaning protocols involve a vapor degreaser, liquid sonication, and alcohol wiping. These methods are not very effective in removing live and dead microbes from spacecraft piece parts of slightly complicated geometry, such as tubing and loosely fitted nuts and bolts. Contamination control practices are traditionally focused on cleaning and monitoring of particulate and oily residual. Vapor degreaser and outgassing bakeout have not been proven to be effective in removing some less volatile, hydrophilic biomolecules of significant relevance to life detection. A precision cleaning technology was developed using supercritical CO2 (SCC). SCC is used as both solvent and carrier for removing organic and particulate contaminants. Supercritical fluid, like SCC, is characterized by physical and thermal properties that are between those of the pure liquid and gas phases. The fluid density is a function of the temperature and pressure. Its solvating power can be adjusted by changing the pressure or temperature, or adding a secondary solvent such as alcohol or water. Unlike a regular organic solvent, SCC has higher diffusivities, lower viscosity, and lower surface tension. It readily penetrates porous and fibrous solids and can reach hard-to-reach surfaces of the parts with complex geometry. Importantly, the CO2 solvent does not leave any residue. The results using this new cleaning device demonstrated that both supercritical CO2 with 5% water as a co-solvent can achieve cleanliness levels of 0.01 mg/cm2 or less for contaminants of a wide range of hydrophobicities. Experiments under the same conditions using compressed Martian air mix, which consists of 95% CO2, produced similar cleaning effectiveness on the hydrophobic compounds. The main components of the SCC cleaning system are a high-pressure cleaning vessel, a boil-off vessel located downstream from the cleaning vessel, a syringe-type high-pressure pump, a heat exchanger, and a back pressure

  6. Behavior of water in supercritical CO2: adsorption and capillary condensation in porous media

    Science.gov (United States)

    Heath, J. E.; Bryan, C. R.; Dewers, T. A.; Wang, Y.

    2011-12-01

    The chemical potential of water in supercritical CO2 (scCO2) may play an important role in water adsorption, capillary condensation, and evaporation under partially saturated conditions at geologic CO2 storage sites, especially if initially anhydrous CO2 is injected. Such processes may affect residual water saturations, relative permeability, shrink/swell of clays, and colloidal transport. We have developed a thermodynamic model of water or brine film thickness as a function of water relative humidity in scCO2. The model is based on investigations of liquid water configuration in the vadose zone and uses the augmented Young-Laplace equation, which incorporates both adsorptive and capillary components. The adsorptive component is based on the concept of disjoining pressure, which reflects force per area normal to the solid and water/brine-scCO2 interfaces. The disjoining pressure includes van der Waals, electrostatic, and structural interactions. The van der Waals term includes the effects of mutual dissolution of CO2 and water in the two fluid phases on partial molar volumes, dielectric coefficients, and refractive indices. Our approach treats the two interfaces as asymmetric surfaces in terms of charge densities and electrostatic potentials. We use the disjoining pressure isotherm to evaluate the type of wetting (e.g., total or partial wetting) for common reservoir and caprock minerals and kerogen. The capillary component incorporates water activity and is applied to simple pore geometries with slits and corners. Finally, we compare results of the model to a companion study by the coauthors on measurement of water adsorption to mineral phases using a quartz-crystal microbalance. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  7. Biological Properties of Fucoxanthin in Oil Recovered from Two Brown Seaweeds Using Supercritical CO2 Extraction

    Directory of Open Access Journals (Sweden)

    Saravana Periaswamy Sivagnanam

    2015-05-01

    Full Text Available The bioactive materials in brown seaweeds hold great interest for developing new drugs and healthy foods. The oil content in brown seaweeds (Saccharina japonica and Sargassum horneri was extracted by using environmentally friendly supercritical CO2 (SC-CO2 with ethanol as a co-solvent in a semi-batch flow extraction process and compared the results with a conventional extraction process using hexane, ethanol, and acetone mixed with methanol (1:1, v/v. The SC-CO2 method was used at a temperature of 45 °C and pressure of 250 bar. The flow rate of CO2 (27 g/min was constant for the entire extraction period of 2 h. The obtained oil from the brown seaweeds was analyzed to determine their valuable compounds such as fatty acids, phenolic compounds, fucoxanthin and biological properties including antioxidant, antimicrobial, and antihypertension effects. The amounts of fucoxanthin extracted from the SC-CO2 oils of S. japonica and S. horneri were 0.41 ± 0.05 and 0.77 ± 0.07 mg/g, respectively. High antihypertensive activity was detected when using mixed acetone and methanol, whereas the phenolic content and antioxidant property were higher in the oil extracted by SC-CO2. The acetone–methanol mix extracts exhibited better antimicrobial activities than those obtained by other means. Thus, the SC-CO2 extraction process appears to be a good method for obtaining valuable compounds from both brown seaweeds, and showed stronger biological activity than that obtained by the conventional extraction process.

  8. Biological Properties of Fucoxanthin in Oil Recovered from Two Brown Seaweeds Using Supercritical CO2 Extraction.

    Science.gov (United States)

    Sivagnanam, Saravana Periaswamy; Yin, Shipeng; Choi, Jae Hyung; Park, Yong Beom; Woo, Hee Chul; Chun, Byung Soo

    2015-05-29

    The bioactive materials in brown seaweeds hold great interest for developing new drugs and healthy foods. The oil content in brown seaweeds (Saccharina japonica and Sargassum horneri) was extracted by using environmentally friendly supercritical CO2 (SC-CO2) with ethanol as a co-solvent in a semi-batch flow extraction process and compared the results with a conventional extraction process using hexane, ethanol, and acetone mixed with methanol (1:1, v/v). The SC-CO2 method was used at a temperature of 45 °C and pressure of 250 bar. The flow rate of CO2 (27 g/min) was constant for the entire extraction period of 2 h. The obtained oil from the brown seaweeds was analyzed to determine their valuable compounds such as fatty acids, phenolic compounds, fucoxanthin and biological properties including antioxidant, antimicrobial, and antihypertension effects. The amounts of fucoxanthin extracted from the SC-CO2 oils of S. japonica and S. horneri were 0.41 ± 0.05 and 0.77 ± 0.07 mg/g, respectively. High antihypertensive activity was detected when using mixed acetone and methanol, whereas the phenolic content and antioxidant property were higher in the oil extracted by SC-CO2. The acetone-methanol mix extracts exhibited better antimicrobial activities than those obtained by other means. Thus, the SC-CO2 extraction process appears to be a good method for obtaining valuable compounds from both brown seaweeds, and showed stronger biological activity than that obtained by the conventional extraction process.

  9. Fayalite Dissolution and Siderite Formation in Water-Saturated Supercritical CO2

    Energy Technology Data Exchange (ETDEWEB)

    Qafoku, Odeta; Kovarik, Libor; Kukkadapu, Ravi K.; Ilton, Eugene S.; Arey, Bruce W.; Tucek, Jiri; Felmy, Andrew R.

    2012-11-25

    Olivines, a significant constituent of basaltic rocks, have the potential to immobilize permanently CO2 after it is injected in the deep subsurface, due to carbonation reactions occurring between CO2 and the host rock. To investigate the reactions of fayalitic olivine with supercritical CO2 (scCO2) and formation of mineral carbonates, experiments were conducted at temperatures of 35 °C to 80 °C, 90 atm pressure and anoxic conditions. For every temperature, the dissolution of fayalite was examined both in the presence of liquid water and H2O-saturated scCO2. The experiments were conducted in a high pressure batch reactor at reaction time extending up to 85 days. The newly formed products were characterized using a comprehensive suite of bulk and surface characterization techniques X-ray diffraction, Transmission/Emission Mössbauer Spectroscopy, Scanning Electron Microscopy coupled with Focused Ion Beam, and High Resolution Transmission Electron Microscopy. Siderite with rhombohedral morphology was formed at 35 °C, 50 °C, and 80 °C in the presence of liquid water and scCO2. In H2O-saturated scCO2, the formation of siderite was confirmed only at high temperature (80 °C). Characterization of reacted samples in H2O-saturated scCO2 with high resolution TEM indicated that siderite formation initiated inside voids created during the initial steps of fayalite dissolution. Later stages of fayalite dissolution result in the formation of siderite in layered vertical structures, columns or pyramids with a rhombus base morphology.

  10. High Resolution X-ray CMT Imaging of Supercritical CO2 in Porous Media: Experimental Challenges, Solutions, and Results

    Science.gov (United States)

    Herring, A. L.; Andersson, L.; Newell, D. L.; Carey, J. W.; Wildenschild, D.

    2013-12-01

    Geologic carbon dioxide (CO2) sequestration has been proposed as a climate change mitigation strategy to limit emissions of CO2 to the atmosphere from large fossil-fuel burning CO2 point sources; however, there are concerns associated with the long-term stability of a mobile subsurface CO2 plume. Capillary trapping of supercritical CO2 (scCO2), wherein the CO2 is held within the pore structure of the geologic matrix by capillary forces, is a more secure form of subsurface storage than structural trapping, which relies on an impermeable caprock to contain the buoyant CO2 plume. To understand the multiphase physics of CO2 transport, and to subsequently produce quantitative estimates of potential CO2 capillary trapping, it is necessary to study field, core, and pore-scale processes. X-ray computed microtomography (x-ray CMT) allows for three-dimensional (3D) in-situ visualization of fluid phases within and the physical structure of a porous medium at the pore-scale. We have designed and built a mobile experimental set-up capable of running at pressures up to 2000 PSI and temperatures up to 50°C, made with materials that are compatible with corrosive fluids. Our experimental procedure includes pressurizing, mixing, and separating fluids; and subsequently running immiscible drainage and imbibition flow experiments with brine and supercritical CO2. With this set-up and procedure, we successfully conducted a brine-scCO2 drainage experiment in Bentheimer sandstone at 1200 PSI and 36°C, and confirmed and quantified CO2 flow in the sandstone core via synchrotron-based x-ray CMT with a resolution of 4.65 μm at the Advanced Photon Source at Argonne National Laboratory. We have proven that we can observe, on a pore-scale basis, the movement of supercritical CO2 within a porous media. The properties of supercritical CO2 (e.g. viscosity, density, interfacial tension and solubility in brine) vary significantly with changes in pressure and temperature; consequently, precise

  11. CO2在超临界区管内冷却的换热关联式%Heat Transfer Correlations for In-tube Cooling of Supercritical CO2

    Institute of Scientific and Technical Information of China (English)

    周子成

    2015-01-01

    自然制冷剂CO2 的应用日益广泛, 尤其是在跨临界循环的热泵热水器中. 本文综述了超临界CO2 在管内冷却传热关联式的比较和验证.%The natural refrigerant CO2 is used widely, especially in trans -critical cycle heat pump water heat-ers. In this paper, the comparison and validation of heat transfer correlations for in-tube cooling of supercritical CO2 is discussed.

  12. Optimization and evaluation of wheat germ oil extracted by supercritical CO2

    Directory of Open Access Journals (Sweden)

    Niu, LiYa

    2011-06-01

    Full Text Available Box-Behnken design combined with response surface methodology (RSM was used to optimize the parameters of supercritical CO2 extraction (SFE of wheat germ oil. The quality of the oil and residual meal obtained by SFE and solvent extraction (SE were evaluated from proximate analysis, fatty acid composition and antioxidant activity. A maximum oil yield of 10.46% was achieved under the optimal conditions of wheat germ particle size 60-80 mesh; water content 4.37%; pressure 30MPa; temperature 40°C extraction time 1.7h. The oil obtained by SFE showed stronger DPPH radical scavenging ability than SE oil at the same concentration. The fatty acid composition of SFE oil was similar to SE oil. Higher contents of protein (34.3% and lysine (2.47g/100g were found in the residual meal obtained by SFE. The results show that oil and defatted meal obtained by SFE can be promising nutritional sources for food.Un diseño Box-Behnken combinado con metodología de superficie de respuesta (RSM fue usado para optimizar los parámetros de extracción con fluido supercrítico (SFE del aceite de germen de trigo. La calidad del aceite y de la harina residual obtenida por SFE y por extracción con solvente (SE fue evaluada mediante su análisis porcentual, composición de ácidos grasos y actividad antioxidante. Un máximo rendimiento de aceite del 10.46% fue obtenido con las condiciones óptimas de 60-80 mesh de tamaño de partícula del germen de trigo; 4.37% contenido de agua; 30MPa de presión; 40°C de temperatura y 1.7 h de tiempo de extracción. El aceite obtenido por SFE mostró una capacidad atrapadora de radicales libres mucho mayor que el aceite obtenido por SE a la misma concentración. La composición de ácidos grasos del aceite SFE fue similar al aceite SE. El mayor contenido de proteínas (34% y de lisina (2.47g/100g fue encontrado en las harinas residuales obtenidas por SFE. Los resultados muestran que el aceite y la harina desengrasada obtenidas por SFE

  13. Partitioning of Organic Compounds into Supercritical CO2 in Depleted Oil Reservoirs - A Review

    Science.gov (United States)

    Burant, A.; Lowry, G. V.; Karamalidis, A.

    2012-12-01

    Depleted oil reservoirs, with enhanced oil recovery, will be one of the first adopters of carbon capture and storage (CCS), which is a promising mitigation strategy for global climate change. The large scale implementation of CCS mandates better understanding of the risks associated with CO2 injection, especially in regards to potential leakage of the stored CO2. Organics, in the residual oil and dissolved in the brine, can partition into supercritical CO2 (sc-CO2) and move with that phase if it leaks. This review presents an overview of the thermodynamic models and trends in experimental partitioning data needed to understand what compounds may be expected to move with the sc-CO2. There are two main types of thermodynamic models used for predicting the solubility of organic compounds in sc-CO2, equations of state and quantitative structure activity relationships. Both can predict the partitioning behavior of one compound in sc-CO2, however only equations of state can predict solubility in multicomponent systems. In addition, equations of state have been developed to determine the effect of electrolytes on the partitioning behavior of organics dissolved in brines. There are three main trends in the partitioning behavior of organics in sc-CO2: Pure phase solubility follows trends in vapor pressure; compounds with higher volatility have higher solubility in sc-CO2. Second, the partitioning from water to sc-CO2 follows trends in Henry's constants, which follow the relative solubility of a compound in both the sc-CO2 and aqueous phases. Thirdly, the solubility of a compound can be enhanced by the presence of another; highly volatile compounds enhance the solubility of compounds with lower volatility. Finally, the review presents the gaps in experimental research that can be used to improve the modeling of the partitioning behavior of organics in sc-CO2, specifically in regards to co-solvency effects and the effects of electrolytes on the partitioning of dissolved

  14. Formation of curcumin nanoparticles via solution-enhanced dispersion by supercritical CO2

    Directory of Open Access Journals (Sweden)

    Zhao Z

    2015-04-01

    solubility and dissolution rate of the curcumin nanoparticles were found to be higher than that of the original curcumin powder (approximately 1.4 µg/mL vs 0.2 µg/mL in 180 minutes. This study revealed that supercritical CO2 technologies had a great potential in fabricating nanoparticles and improving the bioavailability of poorly water-soluble drugs.Keywords: curcumin, crystalline sate, dissolution rate, solubility

  15. Silicate Carbonation Processes in Water-Bearing Supercritical CO2 Fluids: Implications for Geologic Carbon Sequestration

    Science.gov (United States)

    Miller, Q. R.; Schaef, T.; Thompson, C.; Loring, J. S.; Windisch, C. F.; Bowden, M. E.; Arey, B. W.; McGrail, P.

    2012-12-01

    Global climate change is viewed by many as an anthropogenic phenomenon that could be mitigated through a combination of conservation efforts, alternative energy sources, and the development of technologies capable of reducing carbon dioxide (CO2) emissions. Continued increases of atmospheric CO2 concentrations are projected over the next decade, due to developing nations and growing populations. One economically favorable option for managing CO2 involves subsurface storage in deep basalt formations. The silicate minerals and glassy mesostasis basalt components act as metal cation sources, reacting with the CO2 to form carbonate minerals. Most prior work on mineral reactivity in geologic carbon sequestration settings involves only aqueous dominated reactions. However, in most sequestration scenarios, injected CO2 will reside as a buoyant fluid in contact with the sealing formation (caprock) and slowly become water bearing. Comparatively little laboratory research has been conducted on reactions occurring between minerals in the host rock and the wet scCO2. In this work, we studied the carbonation of wollastonite [CaSiO3] exposed to variably wet supercritical CO2 (scCO2) at a range of temperatures (50, 55 and 70 °C) and pressures (90,120 and 160 bar) in order to gain insight into reaction processes. Mineral transformation reactions were followed by two novel in situ high pressure techniques, including x-ray diffraction that tracked the rate and extents of wollastonite conversion to calcite. Increased dissolved water concentrations in the scCO2 resulted in increased carbonation approaching ~50 wt. %. Development of thin water films on the mineral surface were directly observed with infrared (IR) spectroscopy and indirectly with 18O isotopic labeling techniques (Raman spectroscopy). The thin water films were determined to be critical for facilitating carbonation processes in wet scCO2. Even in extreme low water conditions, the IR technique detected the formation of

  16. Investigation of Mineral Transformations in Wet Supercritical CO2 by Electron Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Arey, Bruce W.; Kovarik, Libor; Wang, Zheming; Felmy, Andrew R.

    2011-10-10

    The capture and storage of carbon dioxide and other greenhouse gases in deep geologic formations represents one of the most promising options for mitigating the impacts of greenhouse gases on global warming. In this regard, mineral-fluid interactions are of prime importance since such reactions can result in the long term sequestration of CO2 by trapping in mineral phases. Recently it has been recognized that interactions with neat to water-saturated non-aqueous fluids are of prime importance in understanding mineralization reactions since the introduced CO2 is likely to contain water initially or soon after injection and the supercritical CO2 (scCO2) is less dense than the aqueous phase which can result in a buoyant scCO2 plume contacting the isolating caprock. As a result, unraveling the molecular/microscopic mechanisms of mineral transformation in neat to water saturated scCO2 has taken on an added important. In this study, we are examining the interfacial reactions of the olivine mineral forsterite (Mg2SiO4) over a range of water contents up to and including complete water saturation in scCO2. The surface precipitates that form on the reacted forsterite grains are extremely fragile and difficult to experimentally characterize. In order to address this issue we have developed experimental protocols for preparing and imaging electron-transparent samples from fragile structures. These electron-transparent samples are then examined using a combination of STEM/EDX, FIB-TEM, and helium ion microscope (HIM) imaging (Figures 1-3). This combination of capabilities has provided unique insight into the geochemical processes that occur on scCO2 reacted mineral surfaces. The experimental procedures and protocols that have been developed also have useful applications for examining fragile structures on a wide variety of materials. This research was performed using EMSL, a national scientific user facility sponsored by the Department of Energy's Office of Biological and

  17. Breaking it into pieces for storage: An engineering approach to enhancing supercritical CO2 entrapment

    Science.gov (United States)

    Wang, Y.; Bryan, C. R.; Dewers, T. A.; Heath, J. E.

    2011-12-01

    Geologic carbon sequestration and storage (CSS) is a possible option for the mitigation of carbon dioxide (CO2) emissions to the atmosphere. Residual trapping of a non-wetting liquid phase in a brine reservoir is considered as an important mechanism for long-term CSS, because similar processes have been observed in a variety of fields such as oil recovery and groundwater remediation of non-aqueous phase liquids. Residual trapping can potentially relax stringent requirements for the integrity of cap rocks and allow utilization of open or dipping structures for carbon storage. Here, we propose an engineering approach to enhancing the immobilization of supercritical CO2 (scCO2) in a brine reservoir. This approach is based on the concept of viscous instability of immiscible flow and the dynamics of the movement of scCO2 ganglia in porous media. The movement of a non-wetting ganglion is inversely dependent on its dimension: the smaller the ganglion, the more difficult to move. The critical size (lc) for a ganglion to become immobilized, given its buoyancy, is determined by: lc=2βσ/(rkrw Δρg) where β is the geometric factor characterizing the grain size and pore neck radius (r), σ is the interfacial tension between scCO2 and water, rkrw is the relative permeability to water, Δρ is the density difference between water and scCO2, and g is the gravity. This suggests that, by dispersing injected scCO2 into small ganglia, we can potentially immobilize the injected scCO2 for very long times. The dispersal of scCO2 into small ganglia could be accomplished by controlling the injection rate and the alternating injection of scCO2 and water. The injection rate is required to be high enough to ensure the scCO2 at the advancing front to be broken into pieces, small enough for immobilization, through viscous instability: v>(2π2 r2 krkrw Δρ2 g2)/(μβ2 σ) where v is the velocity of the advancement of scCO2 front, k is the permeability of water and μ is the viscosity of

  18. Pore-scale supercritical CO2 dissolution and mass transfer under drainage conditions

    Science.gov (United States)

    Chang, Chun; Zhou, Quanlin; Oostrom, Mart; Kneafsey, Timothy J.; Mehta, Hardeep

    2017-02-01

    Recently, both core- and pore-scale imbibition experiments have shown non-equilibrium dissolution of supercritical CO2 (scCO2) and a prolonged depletion of residual scCO2. In this study, pore-scale scCO2 dissolution and mass transfer under drainage conditions were investigated using a two-dimensional heterogeneous micromodel and a novel fluorescent water dye with a sensitive pH range between 3.7 and 6.5. Drainage experiments were conducted at 9 MPa and 40 °C by injecting scCO2 into the sandstone-analogue pore network initially saturated by water without dissolved CO2 (dsCO2). During the experiments, time-lapse images of dye intensity, reflecting water pH, were obtained. These images show non-uniform pH in individual pores and pore clusters, with average pH levels gradually decreasing with time. Further analysis on selected pores and pore clusters shows that (1) rate-limited mass transfer prevails with slowly decreasing pH over time when the scCO2-water interface area is low with respect to the volume of water-filled pores and pore clusters, (2) fast scCO2 dissolution and phase equilibrium occurs when scCO2 bubbles invade into water-filled pores, significantly enhancing the area-to-volume ratio, and (3) a transition from rate-limited to diffusion-limited mass transfer occurs in a single pore when a medium area-to-volume ratio is prevalent. The analysis also shows that two fundamental processes - scCO2 dissolution at phase interfaces and diffusion of dsCO2 at the pore scale (10-100 μm) observed after scCO2 bubble invasion into water-filled pores without pore throat constraints - are relatively fast. The overall slow dissolution of scCO2 in the millimeter-scale micromodel can be attributed to the small area-to-volume ratios that represent pore-throat configurations and characteristics of phase interfaces. This finding is applicable for the behavior of dissolution at pore, core, and field scales when water-filled pores and pore clusters of varying size are surrounded

  19. Supercritical CO2 decaffeination of unroasted coffee beans produces melanoidins with distinct NF-κB inhibitory activity.

    Science.gov (United States)

    Chen, Yumin; Brown, Peter H; Hu, Kang; Black, Richard M; Prior, Ronald L; Ou, Boxin; Chu, Yi-Fang

    2011-09-01

    The supercritical CO(2)-decaffeination process causes unroasted coffee beans to turn brown. Therefore, we suspected that the decaffeinated beans contained melanoidins. Decaffeinated unroasted coffee extract absorbed light at 405 nm with a specific extinction coefficient, K(mix 405 nm), of 0.02. Membrane dialysis (molecular weight cut-off, 12 to 14 kDa) increased the K(mix 405 nm) value 15 fold. Gel filtration chromatography showed that the high-MW fraction (MW > 12 kDa) had an elution profile closer to that of melanoidins of medium-roast coffee than to the corresponding fraction of unroasted coffee, indicating the presence of melanoidins in decaffeinated unroasted beans. Using murine myoblast C2C12 cells with a stably transfected nuclear factor-κB (NF-κB) luciferase reporter gene, we found that the high-MW fraction of decaffeinated unroasted beans had an NF-κB inhibitory activity of IC(50) = 499 μg/mL, more potent than that of regular-roast coffee (IC(50) = 766 μg/mL). Our results indicate that melanoidins form during the supercritical CO(2)-decaffeination process and possess biological properties distinct from those formed during the regular roasting process. We discovered the roasting effect of decaffeination process, reporting the discovery of melanoidins in green (unroasted) decaf coffee beans. Our results indicated that melanoidins form during the supercritical CO2-decaffeination process and possess biological properties distinct from those formed during the regular roasting process. Our results offer new insights into the formation of bioactive coffee components during coffee decaffeination process. © 2011 Institute of Food Technologists®

  20. Effect of Allelochemicals of Chinese—fir root extracted by supercritical CO2 extraction on Chinese fir

    Institute of Scientific and Technical Information of China (English)

    LINSi-zu; CAOGuang-qiu; DULing; WANGAi-ping

    2003-01-01

    Allelochemicals of Chinese-fir root was extracted by technology of supercritical CO2 extraction under orthogonal experiment design, and it was used to analyze allelopathic activity of Chinese-fir through bioassay of seed germination, The results showed that as to the available rate of allelochemicals, the pressure and temperature of extraction were the most im-portant factors, The allelochemicals of Chinese-fir root extracted by pure CO2 and ethanol mixed with CO2 have different al-lelopathic activities to seed germination, and the allelochemicals extracted by ethanol mixed with CO2 had stronger inhibitory effects on seed Qermination than that extracted by pure CO2.

  1. [Analysis of the chemical constituents of volatile oil from the Folium Rhododendri Daurici by supercritical CO2 extraction].

    Science.gov (United States)

    Jiao, Shu-qing; Liu, Feng-hua

    2009-02-01

    To compare the chemical constituents of volatile oils from Folium Rhododendri Daurici between supercritical CO2 extraction (SCE-CO2) and steam distillation (SD). The chemical constituents of volatile oils obtained by two methods were analyzed by GC-MS. 52 compounds in the volatile oil extracted by SCE-CO2 and 48 compounds in the volatile oil extracted by SD were separated and identified separately. There were 45 same components. The chemical constituents obtained by SCE-CO2 and SD are approached.

  2. EXTRACTION OF OIL FROM PRESSED PALM OIL (Elaes guineensis FIBERS USING SUPERCRITICAL CO2

    Directory of Open Access Journals (Sweden)

    Luiz F. FRANÇA

    1997-12-01

    Full Text Available Residual fibers from palm oil production are a good source of carotene, since they contain more than 5% of the original oil, with about 5000 ppm of carotenoids. As carotenoids are thermosensitive molecules, supercritical CO2 can be used for oil recovery, because this technique employs low temperatures. In this work results of oil extraction experiments from pressed palm oil fibers are shown. Fibers were from AGROPALMA, an industry which is located in Tailândia (Pará, Brazil. Extractions were carried out at 200, 250 and 300 bar and at temperatures of 45 and 55oC. Oil was analyzed by UV/vis spectrophotometry for total carotene determination. Results showed a large increase in extraction rate from 200 to 250 bar and a small variation from 250 to 300 bar. The total amount of carotenes did not increase in the course of extraction at 300 bar, but it showed a large increase at 200 and at 250 bar. Free fatty acids are present in amounts larger than those found in commercial oils.As fibras residuais do processo de produção de óleo de palma (óleo de dendê, podem ser uma boa fonte de carotenos, pois contém, ainda, mais de 5% do óleo original, com cerca de 5.000 ppm de carotenóides. Como os carotenóides são moléculas termodegradáveis, é importante um estudo do emprego de CO2 supercrítico na extração deste óleo, visto que esta é uma técnica que emprega baixas temperaturas. Neste trabalho são mostrados os resultados de experimentos de extração do óleo das fibras prensadas de dendê, feitas a 200, 250 e 300 bar e temperaturas de 45 e 55oC. As fibras prensadas foram obtidas da produção industrial da indústria AGROPALMA, localizada em Tailândia (Pará, Brasil. O óleo obtido foi analisado por espectrofotometria UV/vis para a determinação do teor de carotenos totais. Os resultados mostram um aumento na taxa de extração entre 200 e 250 bar, mas esta variação foi pequena entre 250 e 300 bar. O teor de carotenos totais não aumenta

  3. Pore-scale supercritical CO2 dissolution and mass transfer under imbibition conditions

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Chun; Zhou, Quanlin; Kneafsey, Timothy J.; Oostrom, Mart; Wietsma, Thomas W.; Yu, Qingchun

    2016-06-01

    In modeling of geological carbon storage, dissolution of supercritical CO2 (scCO2) is often assumed to be instantaneous with equilibrium phase partitioning. In contrast, recent core-scale imbibition experiments have shown a prolonged depletion of residual scCO2 by dissolution, implying a non-equilibrium mechanism. In this study, eight pore-scale scCO2 dissolution experiments in a 2D heterogeneous, sandstone-analogue micromodel were conducted at supercritical conditions (9 MPa and 40 °C). The micromodel was first saturated with deionized (DI) water and drained by injecting scCO2 to establish a stable scCO2 saturation. DI water was then injected at constant flow rates after scCO2 drainage was completed. High resolution time-lapse images of scCO2 and water distributions were obtained during imbibition and dissolution, aided by a scCO2-soluble fluorescent dye introduced with scCO2 during drainage. These images were used to estimate scCO2 saturations and scCO2 depletion rates. Experimental results show that (1) a time-independent, varying number of water-flow channels are created during imbibition and later dominant dissolution by the random nature of water flow at the micromodel inlet, and (2) a time-dependent number of water-flow channels are created by coupled imbibition and dissolution following completion of dominant imbibition. The number of water-flow paths, constant or transient in nature, greatly affects the overall depletion rate of scCO2 by dissolution. The average mass fraction of dissolved CO2 (dsCO2) in water effluent varies from 0.38% to 2.72% of CO2 solubility, indicating non-equilibrium scCO2 dissolution in the millimeter-scale pore network. In general, the transient depletion rate decreases as trapped, discontinuous scCO2 bubbles and clusters within water-flow paths dissolve, then remains low with dissolution of large bypassed scCO2 clusters at their interfaces with longitudinal water flow, and finally increases with coupled transverse water flow and

  4. Uranium extraction from TRISO-coated fuel particles using supercritical CO2 containing tri-n-butyl phosphate.

    Science.gov (United States)

    Zhu, Liyang; Duan, Wuhua; Xu, Jingming; Zhu, Yongjun

    2012-11-30

    High-temperature gas-cooled reactors (HTGRs) are advanced nuclear systems that will receive heavy use in the future. It is important to develop spent nuclear fuel reprocessing technologies for HTGR. A new method for recovering uranium from tristructural-isotropic (TRISO-) coated fuel particles with supercritical CO(2) containing tri-n-butyl phosphate (TBP) as a complexing agent was investigated. TRISO-coated fuel particles from HTGR fuel elements were first crushed to expose UO(2) pellet fuel kernels. The crushed TRISO-coated fuel particles were then treated under O(2) stream at 750°C, resulting in a mixture of U(3)O(8) powder and SiC shells. The conversion of U(3)O(8) into solid uranyl nitrate by its reaction with liquid N(2)O(4) in the presence of a small amount of water was carried out. Complete conversion was achieved after 60 min of reaction at 80°C, whereas the SiC shells were not converted by N(2)O(4). Uranyl nitrate in the converted mixture was extracted with supercritical CO(2) containing TBP. The cumulative extraction efficiency was above 98% after 20 min of online extraction at 50°C and 25 MPa, whereas the SiC shells were not extracted by TBP. The results suggest an attractive strategy for reprocessing spent nuclear fuel from HTGR to minimize the generation of secondary radioactive waste.

  5. Decontamination of Uranium-Contaminated Soil Sand Using Supercritical CO2 with a TBP–HNO3 Complex

    Directory of Open Access Journals (Sweden)

    Kwangheon Park

    2015-09-01

    Full Text Available An environmentally friendly decontamination process for uranium-contaminated soil sand is proposed. The process uses supercritical CO2 as the cleaning solvent and a TBP–HNO3 complex as the reagent. Four types of samples (sea sand and coarse, medium, and fine soil sand were artificially contaminated with uranium. The effects of the amount of the reagent, sand type, and elapsed time after the preparation of the samples on decontamination were examined. The extraction ratios of uranium in all of the four types of sand samples were very high when the time that elapsed after preparation was less than a few days. The extraction ratio of uranium decreased in the soil sand with a higher surface area as the elapsed time increased, indicating the possible formation of chemisorbed uranium on the surface of the samples. The solvent of supercritical CO2 seemed to be very effective in the decontamination of soil sand. However, the extraction of chemisorbed uranium in soil sand may need additional processes, such as the application of mechanical vibration and the addition of bond-breaking reagents.

  6. Supercritical CO2 extraction of oil and omega-3 concentrate from Sacha inchi (Plukenetia volubilis L. from Antioquia, Colombia

    Directory of Open Access Journals (Sweden)

    D. M. Triana-Maldonado

    2017-03-01

    Full Text Available Sacha inchi (Plukenetia volubilis L. seeds were employed for oil extraction with supercritical CO2 at laboratory scale. The supercritical extraction was carried out at a temperature of 60 °C, pressure range of 400–500 bars and CO2 flow of 40–80 g/min. The maximum recovery was 58% in 180 min, favored by increasing the residence time of CO2 in the extraction tank. Subsequently, the process was evaluated at pilot scale reaching a maximum recovery of 60% in 105 min, with a temperature of 60 °C, pressure of 450 bars and CO2 flow of 1270 g/min. The fatty acid composition of the oil was not affected for an extraction period of 30–120 min. The Sacha inchi oil was fractionated with supercritical CO2 to obtain an omega-3 concentrate oil without finding a considerable increase in the proportion of this compound, due to the narrow range in the carbon number of fatty acids present in the oil (16–18 carbons, making it difficult for selective separation.

  7. Relative permeabilities of supercritical CO2 and brine in carbon sequestration by a two-phase lattice Boltzmann method

    Science.gov (United States)

    Xie, Jian.-Fei.; He, S.; Zu, Y. Q.; Lamy-Chappuis, B.; Yardley, B. W. D.

    2017-08-01

    In this paper, the migration of supercritical carbon dioxide (CO2) in realistic sandstone rocks under conditions of saline aquifers, with applications to the carbon geological storage, has been investigated by a two-phase lattice Boltzmann method (LBM). Firstly the digital images of sandstone rocks were reproduced utilizing the X-ray computed microtomography (micro-CT), and high resolutions (up to 2.5 μm) were applied to the pore-scale LBM simulations. For the sake of numerical stability, the digital images were "cleaned" by closing the dead holes and removing the suspended particles in sandstone rocks. In addition, the effect of chemical reactions occurred in the carbonation process on the permeability was taken into account. For the wetting brine and non-wetting supercritical CO2 flows, they were treated as the immiscible fluids and were driven by pressure gradients in sandstone rocks. Relative permeabilities of brine and supercritical CO2 in sandstone rocks were estimated. Particularly the dynamic saturation was applied to improve the reliability of the calculations of the relative permeabilities. Moreover, the effects of the viscosity ratio of the two immiscible fluids and the resolution of digital images on the relative permeability were systematically investigated.

  8. Eco-Efficient Synthesis of Highly Porous CoCO3 Anodes from Supercritical CO2 for Li(+) and Na(+) Storage.

    Science.gov (United States)

    Li, Hui-Ying; Tseng, Chuan-Ming; Yang, Cheng-Hsien; Lee, Tai-Chou; Su, Ching-Yuan; Hsieh, Chien-Te; Chang, Jeng-Kuei

    2017-06-09

    An eco-efficient synthetic route for the preparation of high-performance carbonate anodes for Li(+) and Na(+) batteries is developed. With supercritical CO2 (scCO2 ) as the precursor, which has gas-like diffusivity, extremely low viscosity, and near-zero surface tension, CoCO3 particles are uniformly formed and tightly connected on graphene nanosheets (GNSs). This synthesis can be conducted at 50 °C, which is considerably lower than the temperature required for conventional preparation methods, minimizing energy consumption. The obtained CoCO3 particles (ca. 20 nm in diameter), which have a unique interpenetrating porous structure, can increase the number of electroactive sites, promote electrolyte accessibility, shorten ion diffusion length, and readily accommodate the strain generated upon charging/discharging. With a reversible capacity of 1105 mAh g(-1) , the proposed CoCO3 /GNS anode shows an excellent rate capability, as it can deliver 745 mAh g(-1) in 7.5 min. More than 98 % of the initial capacity is retained after 200 cycles. These properties are clearly superior to those of previously reported CoCO3 -based electrodes for Li(+) storage, indicating the merit of our scCO2 -based synthesis, which is facile, green, and can be easily scaled up for mass production. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Impact of supercritical CO2 injection on petrophysical and rock mechanics properties of chalk: an experimental study on chalk from South Arne field, North Sea

    DEFF Research Database (Denmark)

    Alam, Mohammad Monzurul; Hjuler, Morten Leth; Christensen, Helle Foged

    2011-01-01

    Changes in chalk due to EOR by injecting supercritical CO2 (CO2-EOR) can ideally be predicted by applying geophysical methods designed from laboratory-determined petrophysical and rock mechanics properties. A series of petrophysical and rock mechanics tests were performed on Ekofisk Formation...... and Tor Formation chalk of the South Arne field to reveal the changes in petrophysical and rock mechanics properties of chalk due to the injection of CO2 at supercritical state. An increase in porosity and decrease in specific surface was observed due to injection of supercritical CO2. This indicates...... as indicated by NMR T2 relaxation time was observed. Rock mechanics testing indicates that in 30% porosity chalk from the South Arne field, injection of supercritical CO2 has no significant effect on shear strength and compaction properties, while there is probably a slight decrease in stiffness properties...

  10. Ionic Effects on Supercritical CO2-Brine Interfacial Tensions: Molecular Dynamics Simulations and a Universal Correlation with Ionic Strength, Temperature, and Pressure.

    Science.gov (United States)

    Zhao, Lingling; Ji, Jiayuan; Tao, Lu; Lin, Shangchao

    2016-09-13

    For geological CO2 storage in deep saline aquifers, the interfacial tension (IFT) between supercritical CO2 and brine is critical for the storage security and design of the storage capacitance. However, currently, no predictive model exists to determine the IFT of supercritical CO2 against complex electrolyte solutions involving various mixed salt species at different concentrations and compositions. In this paper, we use molecular dynamics (MD) simulations to investigate the effect of salt ions on the incremental IFT at the supercritical CO2-brine interface with respect to that at the reference supercritical CO2-water interface. Supercritical CO2-NaCl solution, CO2-CaCl2 solution and CO2-(NaCl+CaCl2) mixed solution systems are simulated at 343 K and 20 MPa under different salinities and salt compositions. We find that the valence of the cations is the primary contributor to the variation in IFT, while the Lennard-Jones potentials for the cations pose a smaller impact on the IFT. Interestingly, the incremental IFT exhibits a general linear correlation with the ionic strength in the above three electrolyte systems, and the slopes are almost identical and independent of the solution types. Based on this finding, a universal predictive formula for IFTs of CO2-complex electrolyte solution systems is established, as a function of ionic strength, temperature, and pressure. The predicted IFTs using the established formula agree perfectly (with a high statistical confidence level of ∼96%) with a wide range of experimental data for CO2 interfacing with different electrolyte solutions, such as those involving MgCl2 and Na2SO4. This work provides an efficient and accurate route to directly predict IFTs in supercritical CO2-complex electrolyte solution systems for practical engineering applications, such as geological CO2 sequestration in deep saline aquifers and other interfacial systems involving complex electrolyte solutions.

  11. Using ground and intact coal Samples to evaluate hydrocarbon fate during supercritical CO2 injection into coal beds: effects of particle size and coal moisture

    Science.gov (United States)

    Kolak, Jon; Hackley, Paul C.; Ruppert, Leslie F.; Warwick, Peter D.; Burruss, Robert

    2015-01-01

    To investigate the potential for mobilizing organic compounds from coal beds during geologic carbon dioxide (CO2) storage (sequestration), a series of solvent extractions using dichloromethane (DCM) and using supercritical CO2 (40 °C and 10 MPa) were conducted on a set of coal samples collected from Louisiana and Ohio. The coal samples studied range in rank from lignite A to high volatile A bituminous, and were characterized using proximate, ultimate, organic petrography, and sorption isotherm analyses. Sorption isotherm analyses of gaseous CO2 and methane show a general increase in gas storage capacity with coal rank, consistent with findings from previous studies. In the solvent extractions, both dry, ground coal samples and moist, intact core plug samples were used to evaluate effects of variations in particle size and moisture content. Samples were spiked with perdeuterated surrogate compounds prior to extraction, and extracts were analyzed via gas chromatography–mass spectrometry. The DCM extracts generally contained the highest concentrations of organic compounds, indicating the existence of additional hydrocarbons within the coal matrix that were not mobilized during supercritical CO2 extractions. Concentrations of aliphatic and aromatic compounds measured in supercritical CO2 extracts of core plug samples generally are lower than concentrations in corresponding extracts of dry, ground coal samples, due to differences in particle size and moisture content. Changes in the amount of extracted compounds and in surrogate recovery measured during consecutive supercritical CO2extractions of core plug samples appear to reflect the transition from a water-wet to a CO2-wet system. Changes in coal core plug mass during supercritical CO2 extraction range from 3.4% to 14%, indicating that a substantial portion of coal moisture is retained in the low-rank coal samples. Moisture retention within core plug samples, especially in low-rank coals, appears to inhibit

  12. [Technology of extraction of essential oil from leaves of Vitex negundo L. var. heterophylla (Franch.) Rehd. by supercritical CO2 apparatus].

    Science.gov (United States)

    Xie, Jianchun; Sun, Baoguo; Zheng, Fuping; Yu, Min

    2005-12-01

    By the designation of mono-factor experiments and orthogonal multifactor experiments, influences of extraction temperature, extraction pressure, CO2 flow rate and extraction times on the yield of oil from the leaves of Vitex negundo L. var. heterophylla (Franch.) Rehd. in the supercritical CO2 extraction process were investigated. The obtained optimal extraction technology was: the extraction pressure: 22 MPa; the extraction temperature: 45 degrees C; the CO2 flow rate: 25 L/h and the extraction time: 3h. The oil yield on the above supercritical CO2 extraction conditions was 3.22%.

  13. 超临界CO2技术在PP中应用进展%Application Progress of Supercritical CO2 Technology for Polypropylene

    Institute of Scientific and Technical Information of China (English)

    李峰; 康鹏; 金滟

    2012-01-01

    The application of the supercritical CO2 technology to polypropylene in grafting modification, crystallizing modification, microporous foamed material, processing and composite material at home and abroad is reviewed. And the application prospect of the supercritical CO2 technology is predicted.%综述了超临界CO2(SC-CO2)技术在聚丙烯(PP)接枝改性、结晶改性、PP微发泡材料、加工和复合材料等方面应用,并展望了SC-CO2技术在PP中的应用前景.

  14. Inhibition of AKT signaling by supercritical CO2 extract of mango ginger (Curcuma amada Roxb.) in human glioblastoma cells.

    Science.gov (United States)

    Ramachandran, Cheppail; Portalatin, Gilda; Quirin, Karl-W; Escalon, Enrique; Khatib, Ziad; Melnick, Steven J

    2015-12-01

    Mango ginger (Curcuma amada Roxb.) is a less-investigated herb for anticancer properties than other related Curcuma species. AKT (a serine/threonine protein kinase B, originally identified as an oncogene in the transforming retrovirus AKT8) plays a central role in the development and promotion of cancer. In this investigation, we have analyzed the effect of supercritical CO2 extract of mango ginger (CA) on the genetic pathways associated with AKT signaling in human glioblastoma cells. The inhibitory effect of supercritical CO2 extract of mango ginger (Curcuma amada) on AKT signaling was investigated in U-87MG glioblastoma cells. CA was highly cytotoxic to glioblastoma cell line (IC50=4.92±0.81 µg/mL) compared to mHypoE-N1 normal mouse hypothalamus cell line (IC50=40.57±0.06 µg/mL). CA inhibits AKT (protein Kinase B) and adenosine monophophate -activated protein kinase α (AMPKα) phosphorylation significantly in a dose-dependent manner. The cell migration which is necessary for invasion and metastasis was also inhibited by CA treatment, with about 43% reduction at 20 µg/mL concentration. Analysis of mRNA and protein expression of genes associated with apoptosis, cell proliferation and angiogenesis showed that CA modulates expression of genes associated with apoptosis (Bax, Bcl-2, Bcl-X, BNIP3, caspase-3, mutant p53 and p21), cell proliferation (Ki67) and angiogenesis vascular endothelial growth factor (VEGF). Additionally, heat shock protein 90 (HSP90) and AMPKα genes interacting with the AKT signaling pathway were also downregulated by CA treatment. These results indicate the molecular targets and mechanisms underlying the anticancer effect of CA in human glioblastoma cells.

  15. Synthesis of a proline-modified acrylic acid copolymer in supercritical CO2 for glass-ionomer dental cement applications.

    Science.gov (United States)

    Moshaverinia, Alireza; Roohpour, Nima; Darr, Jawwad A; Rehman, Ihtesham U

    2009-06-01

    Supercritical (sc-) fluids (such as sc-CO(2)) represent interesting media for the synthesis of polymers in dental and biomedical applications. Sc-CO(2) has several advantages for polymerization reactions in comparison to conventional organic solvents. It has several advantages in comparison to conventional polymerization solvents, such as enhanced kinetics, being less harmful to the environment and simplified solvent removal process. In our previous work, we synthesized poly(acrylic acid-co-itaconic acid-co-N-vinylpyrrolidone) (PAA-IA-NVP) terpolymers in a supercritical CO(2)/methanol mixture for applications in glass-ionomer dental cements. In this study, proline-containing acrylic acid copolymers were synthesized, in a supercritical CO(2) mixture or in water. Subsequently, the synthesized polymers were used in commercially available glass-ionomer cement formulations (Fuji IX commercial GIC). Mechanical strength (compressive strength (CS), diametral tensile strength (DTS) and biaxial flexural strength (BFS)) and handling properties (working and setting time) of the resulting modified cements were evaluated. It was found that the polymerization reaction in an sc-CO(2)/methanol mixture was significantly faster than the corresponding polymerization reaction in water and the purification procedures were simpler for the former. Furthermore, glass-ionomer cement samples made from the terpolymer prepared in sc-CO(2)/methanol exhibited higher CS and DTS and comparable BFS compared to the same polymer synthesized in water. The working properties of glass-ionomer formulations made in sc-CO(2)/methanol were comparable and better than the values of those for polymers synthesized in water.

  16. SELECTIVE HYDROGENATION OF MALEIC ANHYDRIDE TO Y-BUTYROLACTONE OVER PD/AL(2)O(3) CATALYST USING SUPERCRITICAL CO(2) AS SOLVENT

    Science.gov (United States)

    A selective hydrogenation of maleic anhydride to either y-butyrolactone or succinic anhydride over simple Pd/Al(2)O(3) catalyst under supercritical CO(2) medium is described for the first time which has considerable promise for obht lab-scale as well as industrial selective hydro...

  17. Substantial rate enhancements of the esterification reaction of phthalic anhydride with methanol at high pressure and using supercritical CO2 as a co-solvent in a glass microreactor

    NARCIS (Netherlands)

    Benito-Lopez, F.; Tiggelaar, Roald M.; Salblut, K.; Huskens, Jurriaan; Egberink, Richard J.M.; Reinhoudt, David; Gardeniers, Johannes G.E.; Verboom, Willem

    2007-01-01

    The esterification reaction of phthalic anhydride with methanol was performed at different temperatures in a continuous flow glass microreactor at pressures up to 110 bar and using supercritical CO2 as a co-solvent. The design is such that supercritical CO2 can be generated inside the microreactor.

  18. The use of solvent extractions and solubility theory to discern hydrocarbon associations in coal, with application to the coal-supercritical CO2 system

    Science.gov (United States)

    Kolak, Jonathan J.; Burruss, Robert A.

    2014-01-01

    Samples of three high volatile bituminous coals were subjected to parallel sets of extractions involving solvents dichloromethane (DCM), carbon disulfide (CS2), and supercritical carbon dioxide (CO2) (40 °C, 100 bar) to study processes affecting coal–solvent interactions. Recoveries of perdeuterated surrogate compounds, n-hexadecane-d34 and four polycyclic aromatic hydrocarbons (PAHs), added as a spike prior to extraction, provided further insight into these processes. Soxhlet-DCM and Soxhlet-CS2 extractions yielded similar amounts of extractable organic matter (EOM) and distributions of individual hydrocarbons. Supercritical CO2 extractions (40 °C, 100 bar) yielded approximately an order of magnitude less EOM. Hydrocarbon distributions in supercritical CO2 extracts generally mimicked distributions from the other solvent extracts, albeit at lower concentrations. This disparity increased with increasing molecular weight of target hydrocarbons. Five- and six-ring ring PAHs generally were not detected and no asphaltenes were recovered in supercritical CO2 extractions conducted at 40 °C and 100 bar. Supercritical CO2 extraction at elevated temperature (115 °C) enhanced recovery of four-ring and five-ring PAHs, dibenzothiophene (DBT), and perdeuterated PAH surrogate compounds. These results are only partially explained through comparison with previous measurements of hydrocarbon solubility in supercritical CO2. Similarly, an evaluation of extraction results in conjunction with solubility theory (Hildebrand and Hansen solubility parameters) does not fully account for the hydrocarbon distributions observed among the solvent extracts. Coal composition (maceral content) did not appear to affect surrogate recovery during CS2 and DCM extractions but might affect supercritical CO2 extractions, which revealed substantive uptake (partitioning) of PAH surrogates into the coal samples. This uptake was greatest in the sample (IN-1) with the highest vitrinite content. These

  19. 超临界CO2与润滑油体系的分子动力学研究%Molecular Dynamics Simulation on the Hybrid System of Supercritical CO2 with Lubricating Oil

    Institute of Scientific and Technical Information of China (English)

    雷佩玉; 李赵; 刘东来; 王永庆; 靳遵龙

    2016-01-01

    应用平衡分子动力学模拟的方法,研究了CO2流体在超临界状态下的微观结构和宏观性能。结果表明,超临界CO2的键长和键角分布基本符合高斯分布规律,超临界CO2系统中二聚体的比例随着压力的增加而发生变化。当系统内压力大于9 MPa时,T形二聚体的比例较大,推断出T形二聚体的存在使得CO2在超临界状态下的物理性质变化剧烈。同时研究了润滑油对超临界CO2的微观特性和传热的影响,结果表明,一定含量的润滑油的混入,改变了CO2团簇体的分布比例,从而给制冷循环系统的流动与换热带来负面影响。%Equilibrium molecular dynamics ( EMD) simulations were carried out to investigate the micro-mechanism and macro performance of CO2 fluid in the supercritical state. The results showed that the bond length and bond angle distributions of supercritical CO2 were Gaussian distribution basically. The dimers’ proportion of supercritical CO2 system changed with the increase of pressure. T-type dimer had high share within the system when pressure was higher than 9 MPa. It could be inferred that T-type dimer led to CO2 physical properties changing violently in supercritical state. The effect that lubricating oil made on microstructure and heat transfer of supercritical CO2 was also investigated. The results showed that a certain concentration of lubricating oil would change the distribution ratio of CO2 cluster body. Then it would have a negative impact on flow and heat transfer of the refrigeration cycle system.

  20. Conceptual System Design of a Supercritical CO2 cooled Micro Modular Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seong Gu; Oh, Bongseong; Baik, Seung Joon; Yu, Hwanyeal; Kim, Yonghee; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of)

    2015-05-15

    The S-CO2 Brayton cycle has many advantages for SMR's power conversion system. The S-CO2 cycle can achieve small component size and simple cycle layout as shown in Fig. 1. Therefore, a concept of one module containing the S-CO2 cooled fast reactor core and power conversion system is realizable. Thanks to the compact heat exchanger technology such as Printed Circuit Heat Exchanger (PCHE), the supercritical fluid with mediocre heat transfer performance can be utilized to a thermal cycle. This concept of fully modularized reactor is named as KAIST Micro Modular Reactor (MMR). It can achieve large economic by production in series, and transported in the land way or sea way. Based on the design results and dimensions of the reactor core and cycle components, the authors propose a conceptual layout of KAIST MMR. Based on this concept of reactor core, power conversion system, and decay heat removal system, the seasonal operation and transient analysis will be performed in the further works.

  1. Supercritical CO2 pipeline transportation and safety%超临界CO2管道输送与安全

    Institute of Scientific and Technical Information of China (English)

    蒋秀; 屈定荣; 刘小辉

    2013-01-01

    Supercritical CO2 transportation by pipeline is the most economical and feasible method to transport large-scale CO2.There are already some short distance gaseous CO2 pipelines in China,but not long distance supercritical CO2 pipelines yet.The paper introduces the status quo of supercritical CO2 pipelines overseas,and there are no design and operation reference standards and CO2 quality control standards yet.The risk and security issues related to pipeline transmission,such as corrosion,elastomeric seals,leakage and running fracture of supercritical CO2 pipeline are analyzed.The aim of this paper is to draw upon the design,operating and risk control experiences gained from the existing CO2 pipeline networks to provide references to the design and operation of supercritical CO2 pipeline in China.Special attention should be paid on safety since the supercritical CO2 pipeline will inevitably pass through densely populated areas in China.%通过管道输送超临界CO2是大规模运输CO2最经济、可行的方法,国内目前仅有少量短程气态CO2输送管道,尚无超临界CO2长输管道.介绍了国外超临界CO2管道的发展现状,迄今尚无针对性的管道设计、运行参考标准及管输超临界CO2的质量控制标准.分析了超临界CO2管道腐蚀、橡胶溶胀、泄漏、断裂等影响超临界CO2管道运行安全的因素及控制经验,可为中国未来超临界CO2管道的设计与运行提供参考.国内建设超临界CO2输送管道必然经过人口密集区域,运行风险增大,应予以重视.

  2. Effects of salinity and the extent of water on supercritical CO2-induced phlogopite dissolution and secondary mineral formation.

    Science.gov (United States)

    Shao, Hongbo; Ray, Jessica R; Jun, Young-Shin

    2011-02-15

    To ensure the viability of geologic CO2 sequestration (GCS), we need a holistic understanding of reactions at supercritical CO2 (scCO2)-saline water-rock interfaces and the environmental factors affecting these interactions. This research investigated the effects of salinity and the extent of water on the dissolution and surface morphological changes of phlogopite [KMg2.87Si3.07Al1.23O10(F,OH)2], a model clay mineral in potential GCS sites. Salinity enhanced the dissolution of phlogopite and affected the location, shape, size, and phase of secondary minerals. In low salinity solutions, nanoscale particles of secondary minerals formed much faster, and there were more nanoparticles than in high salinity solutions. The effect of water extent was investigated by comparing scCO2-H2O(g)-phlogopite and scCO2-H2O(l)-phlogopite interactions. Experimental results suggested that the presence of a thin water film adsorbed on the phlogopite surface caused the formation of dissolution pits and a surface coating of secondary mineral phases that could change the physical properties of rocks. These results provide new information for understanding reactions at scCO2-saline water-rock interfaces in deep saline aquifers and will help design secure and environmentally sustainable CO2 sequestration projects.

  3. New Linear Partitioning Models based on Experimental Water – Supercritical CO2 Partitioning Data of Selected Organic Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Burant, Aniela S.; Thompson, Christopher J.; Lowry, Gregory; Karamalidis, Athanasios

    2016-05-17

    Partitioning coefficients of organic compounds between water and supercritical CO2 (sc-CO2) are necessary to assess the risk of migration of these chemicals from subsurface CO2 storage sites. Despite the large number of potential organic contaminants, the current data set of published water-sc-CO2 partitioning coefficients is very limited. Here, the partitioning coefficients of thiophene, pyrrole, and anisole were measured in situ over a range of temperatures and pressures using a novel pressurized batch reactor system with dual spectroscopic detectors: a near infrared spectrometer for measuring the organic analyte in the CO2 phase, and a UV detector for quantifying the analyte in the aqueous phase. Our measured partitioning coefficients followed expected trends based on volatility and aqueous solubility. The partitioning coefficients and literature data were then used to update a published poly-parameter linear free energy relationship and to develop five new linear free energy relationships for predicting water-sc-CO2 partitioning coefficients. Four of the models targeted a single class of organic compounds. Unlike models that utilize Abraham solvation parameters, the new relationships use vapor pressure and aqueous solubility of the organic compound at 25 °C and CO2 density to predict partitioning coefficients over a range of temperature and pressure conditions. The compound class models provide better estimates of partitioning behavior for compounds in that class than the model built for the entire dataset.

  4. Supercritical CO2 extraction of beta-carotene from a marine strain of the cyanobacterium Synechococcus species.

    Science.gov (United States)

    Montero, Olimpio; Macías-Sánchez, Maria Dolores; Lama, Carmen M; Lubián, Luis M; Mantell, Casimiro; Rodríguez, Miguel; de la Ossa, Enrique M

    2005-12-14

    Dynamic extraction of carotenoids from a marine strain of Synechococcus sp. (Cyanophyceae) with supercritical CO2 (SC-CO2) was investigated with regard to operation pressure and temperature effects on extraction efficiency. Extraction yield (milligrams of pigment per gram of dry weight) for SC-CO2) was compared with the extraction yield for dimethylformamide (DMF). Carotenoids extracted with SC-CO2 were beta-carotene (Ct), zeaxanthin (Z), beta-cryptoxanthin (Cr), and equinenone; chlorophyll a was poorly extracted, whereas myxoxanthophyll, another major carotenoid, was not extracted under any experimental condition. The highest relative yield, which is defined here as y(r) = [(mg of pigment(SC-CO2)/mg of pigment(DMF))] x 100, was 76.1 +/- 8.6% for Ct, but it rose to 87.0 +/- 3.4% when 15% ethanol was used as cosolvent. The pressure effect on y(r) was found to be significant (p extraction were determined to be (358, 50) for Ct, (454, 59) for Cr, and (500, 60) for Z. Cell disruption by sonication or detergent treatment of the biomass did not improve the extraction efficiency. Matrix structure together with material state could explain the low carotenoid extraction yield obtained with SC-CO2 as compared to DMF in Synechococcus sp. However, the process can be applied to selective extraction of different carotenoids.

  5. SYNTHESIS AND CHARACTERIZATION OF HIERARCHICALLY POROUS SILICA WITH POPLAR TISSUE AS TEMPLATE WITH ASSISTANCE OF SUPERCRITICAL CO2

    Directory of Open Access Journals (Sweden)

    Wei Ni

    2008-05-01

    Full Text Available Hierarchically porous silica samples, ranging from mesopores to macropores, were prepared by “nanoscale casting using supercritical (SC fluids” (NC-SCF technology and bionics, achieving a biomineralization process in an environmentally friendly and efficient way. These wood-templated SiO2 samples, having special hierarchical pore sizes from 3.3 nm up to 50 μm, were obtained with SC-CO2 precursor solution by a wood-silication method. For this method, the precursor, tetraethyl orthosilicate (TEOS, was dissolved in SC-CO2 and impregnated into poplar tissue cells using SC-CO2 as a mass carrier. After removal of the wood template by calcination in air at suitable temperatures, the porous silica was obtained. The effects of CO2 pressure and precursor concentration on the impregnating ratio were studied, and the products were characterized. SEM experimental results showed that the obtained silica had the same external and internal structures of the original wood. XRD and N2 absorption-desorption results indicated that the silica was amorphous but crystallized with the calcination temperature up to 1000℃, and had a preferable BET surface area being up to 469 m2/g (600℃. So this work provides a simple and timesaving route to obtain and control the special microstructure of silica with the aid of a wood template in supercritical CO2.

  6. Lattice Boltzmann simulations of supercritical CO2-water drainage displacement in porous media: CO2 saturation and displacement mechanism.

    Science.gov (United States)

    Yamabe, Hirotatsu; Tsuji, Takeshi; Liang, Yunfeng; Matsuoka, Toshifumi

    2015-01-06

    CO2 geosequestration in deep aquifers requires the displacement of water (wetting phase) from the porous media by supercritical CO2 (nonwetting phase). However, the interfacial instabilities, such as viscous and capillary fingerings, develop during the drainage displacement. Moreover, the burstlike Haines jump often occurs under conditions of low capillary number. To study these interfacial instabilities, we performed lattice Boltzmann simulations of CO2-water drainage displacement in a 3D synthetic granular rock model at a fixed viscosity ratio and at various capillary numbers. The capillary numbers are varied by changing injection pressure, which induces changes in flow velocity. It was observed that the viscous fingering was dominant at high injection pressures, whereas the crossover of viscous and capillary fingerings was observed, accompanied by Haines jumps, at low injection pressures. The Haines jumps flowing forward caused a significant drop of CO2 saturation, whereas Haines jumps flowing backward caused an increase of CO2 saturation (per injection depth). We demonstrated that the pore-scale Haines jumps remarkably influenced the flow path and therefore equilibrium CO2 saturation in crossover domain, which is in turn related to the storage efficiency in the field-scale geosequestration. The results can improve our understandings of the storage efficiency by the effects of pore-scale displacement phenomena.

  7. Experimental study of crossover from capillary to viscous fingering for supercritical CO2-water displacement in a homogeneous pore network.

    Science.gov (United States)

    Wang, Ying; Zhang, Changyong; Wei, Ning; Oostrom, Mart; Wietsma, Thomas W; Li, Xiaochun; Bonneville, Alain

    2013-01-02

    Carbon sequestration in saline aquifers involves displacing brine from the pore space by supercritical CO(2) (scCO(2)). The displacement process is considered unstable due to the unfavorable viscosity ratio between the invading scCO(2) and the resident brine. The mechanisms that affect scCO(2)-water displacement under reservoir conditions (41 °C, 9 MPa) were investigated in a homogeneous micromodel. A large range of injection rates, expressed as the dimensionless capillary number (Ca), was studied in two sets of experiments: discontinuous-rate injection, where the micromodel was saturated with water before each injection rate was imposed, and continuous-rate injection, where the rate was increased after quasi-steady conditions were reached for a certain rate. For the discontinuous-rate experiments, capillary fingering and viscous fingering are the dominant mechanisms for low (logCa ≤ -6.61) and high injection rates (logCa ≥ -5.21), respectively. Crossover from capillary to viscous fingering was observed for logCa = -5.91 to -5.21, resulting in a large decrease in scCO(2) saturation. The discontinuous-rate experimental results confirmed the decrease in nonwetting fluid saturation during crossover from capillary to viscous fingering predicted by numerical simulations by Lenormand et al. (J. Fluid Mech.1988, 189, 165-187). Capillary fingering was the dominant mechanism for all injection rates in the continuous-rate experiment, resulting in monotonic increase in scCO(2) saturation.

  8. Antioxidant effect of supercritical CO2 extracted Nigella sativa L. seed extract on deep fried oil quality parameters.

    Science.gov (United States)

    Solati, Zeinab; Baharin, Badlishah Sham

    2015-06-01

    Effect of supercritical CO2 extracted Nigella sativa L. seed extract (NE) on frying performance of sunflower oil and refined, bleached and deodorized (RBD) palm olein was investigated at concentrations of 1.2 % and 1.0 % respectively. Two frying systems containing 0 % N. sativa L. extract (Control) and 0.02 % butylated hydroxytoluene (BHT) were used for comparison. Physicochemical properties such as fatty acid composition (FAC), Peroxide Value (PV), Anisidine Value (AV), Totox Value (TV), Total Polar Content (TPC), C18:2/C16:0 ratio and viscosity of frying oils were determined during five consecutive days of frying. Results have shown that N. sativa L. extract was able to improve the oxidative stability of both frying oils during the frying process compared to control. The stabilizing effect of antioxidants were in the order of BHT > NE. RBD palm olein was found to be more stable than sunflower oil based on the ratio of linoleic acid (C18:2) to palmitic acid (C16:0) and fatty acid composition.

  9. The effect of processing variables on morphological and mechanical properties of supercritical CO2 foamed scaffolds for tissue engineering.

    Science.gov (United States)

    White, Lisa J; Hutter, Victoria; Tai, Hongyun; Howdle, Steven M; Shakesheff, Kevin M

    2012-01-01

    The porous structure of a scaffold determines the ability of bone to regenerate within this environment. In situations where the scaffold is required to provide mechanical function, balance must be achieved between optimizing porosity and maximizing mechanical strength. Supercritical CO(2) foaming can produce open-cell, interconnected structures in a low-temperature, solvent-free process. In this work, we report on foams of varying structural and mechanical properties fabricated from different molecular weights of poly(DL-lactic acid) P(DL)LA (57, 25 and 15 kDa) and by varying the depressurization rate. Rapid depressurization rates produced scaffolds with homogeneous pore distributions and some closed pores. Decreasing the depressurization rate produced scaffolds with wider pore size distributions and larger, more interconnected pores. In compressive testing, scaffolds produced from 57 kDa P(DL)LA exhibited typical stress-strain curves for elastomeric open-cell foams whereas scaffolds fabricated from 25 and 15 kDa P(DL)LA behaved as brittle foams. The structural and mechanical properties of scaffolds produced from 57 kDa P(DL)LA by scCO(2) ensure that these scaffolds are suitable for potential applications in bone tissue engineering.

  10. The dependence of Nusselt number on Reynolds number for a hot-wire sensor in supercritical CO2 flow

    Science.gov (United States)

    Vukoslavcevic, Petar; Wallace, James

    2005-11-01

    An analysis of the heat transfer mechanism around a hot-wire sensor in superctitical CO2 flow has been performed, and the dependence of the Nusselt number (Nu) on the Reynolds number (Re) has been determined. A special, closed flow loop, capable of inducing variable speed flow at different pressures and temperatures in the ranges of 0.15-2 m/s, 15-70^oC and 1-100 bar, has been used to create a supercritical CO2 flow around a hot-wire sensor operated in the constant temperature mode. The Nu and Re numbers were determined based on the known heat convected from the sensor, the flow speed and the sensor temperature and dimensions. The experiment was performed along a line of constant 80 bar pressure in the temperature range of 25-65^oC. It was found that, at a given pressure and temperature, the relation Nu=F(Re) has the classical form Nu=M+NRe^n, with the parameters M and N being functions of pressure and temperature. The dependence of these parameters on temperature was analyzed, and the most convenient reference temperature was chosen. In contrast to the operation of hot-wires in air and water, the dependence of the parameters M and N on the Prandtl number can result in nonunique solutions.

  11. A study on amphiphilic fluorinated block copolymer in graphite exfoliation using supercritical CO2 for stable graphene dispersion.

    Science.gov (United States)

    Kim, Young Hyun; Lee, Hyang Moo; Choi, Sung Wook; Cheong, In Woo

    2017-09-18

    In this study, poly(2,2,2-trifluoroethyl methacrylate)-block-poly(4-vinylpyridine) (PTFEMA-b-PVP) was synthesized by stepwise reversible addition-fragmentation chain transfer (RAFT) polymerization for the preparation of graphene by the exfoliation of graphite nanoplatelets (GPs) in supercritical CO2 (SCCO2). Two different block copolymers (low and high molecular weights) were prepared with the same block ratio and used at different concentrations in the SCCO2 process. The amount of PTFEMA-b-PVP adsorbed on the GPs and the electrical conductivity of the SCCO2-treated GP samples were evaluated using thermogravimetric analysis (TGA) and four-point probe method, respectively. All GP samples treated with SCCO2 were then dispersed in methanol and the dispersion stability was investigated using online turbidity measurements. The concentration and morphology of few-layer graphene stabilized with PTFEMA-b-PVP in the supernatant solution were investigated by gravimetry, scanning electron microscopy, and Raman spectroscopy. Destabilization study of the graphene dispersions revealed that the longer block copolymer exhibited better affinity for graphene, resulting in a higher yield of stable graphene with minimal defects. Copyright © 2017. Published by Elsevier Inc.

  12. Formation of submicron magnesite during reaction of natural forsterite in H2O-saturated supercritical CO2

    Science.gov (United States)

    Qafoku, Odeta; Hu, Jianzhi; Hess, Nancy J.; Hu, Mary Y.; Ilton, Eugene S.; Feng, Ju; Arey, Bruce W.; Felmy, Andrew R.

    2014-06-01

    Natural forsterite was reacted in bulk liquid water saturated with supercritical CO2 (scCO2) and scCO2 saturated with water at 35-80 °C and 90 atm. The solid reaction products were analyzed with nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), and confocal Raman spectroscopy. Two carbonate phases, nesquehonite (MgCO3·3H2O) and magnesite (MgCO3), were identified with the proportions of the two phases depending on experimental conditions. In liquid water saturated with scCO2, nesquehonite was the dominant carbonate phase at 35-80 °C with only a limited number of large, micron size magnesite particles forming at the highest temperature, 80 °C. In contrast, in scCO2 saturated with H2O magnesite formation was identified at all three temperatures: 35, 50, and 80 °C. Magnesite was the dominant carbonation reaction product at 50 and 80 °C, but nesquehonite was dominant at 35 °C. The magnesite particles formed under scCO2 saturated with H2O conditions exhibited an extremely uniform submicron grain-size and nearly identical rhombohedral morphologies at all temperatures. The distribution and form of the particles were not consistent with nucleation and growth on the forsterite surface.

  13. Formation of Submicron Magnesite during Reaction of Natural Forsterite in H2O-Saturated Supercritical CO2

    Energy Technology Data Exchange (ETDEWEB)

    Qafoku, Odeta; Hu, Jian Z.; Hess, Nancy J.; Hu, Mary Y.; Ilton, Eugene S.; Feng, Ju; Arey, Bruce W.; Felmy, Andrew R.

    2014-06-01

    Natural forsterite was reacted in a) liquid water saturated with supercritical CO2 (scCO2) and in b) H2O-saturated scCO2 at 35-80 °C and 90 atm. The solid reaction products were analyzed with nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), and confocal Raman spectroscopy. Two carbonate phases, nesquehonite (MgCO3.3H2O) and magnesite (MgCO3), were identified with the proportions of the two phases depending on experimental conditions. In water saturated with scCO2, nesquehonite was the dominant carbonate phase at 35-80 °C with only a limited number of large, micron size magnesite particles forming at the highest temperature, 80 °C. In contrast, in H2O-saturated scCO2 magnesite formation was identified at all three temperatures: 35 °, 50 °, and 80 °C. Magnesite was the dominant carbonation reaction product at 50 ° and 80 °C; but nesquehonite was dominant at 35 °C. The magnesite particles formed under H2O-saturated scCO2 conditions exhibited an extremely uniform submicron grain-size and nearly identical rhombohedral morphologies at all temperatures. The distribution and form of the particles were not consistent with epitaxial nucleation and growth on the forsterite surface.

  14. Impact of solvents and supercritical CO2 drying on the morphology and structure of polymer-based biofilms

    Science.gov (United States)

    Causa, Andrea; Salerno, Aurelio; Domingo, Concepción; Acierno, Domenico; Filippone, Giovanni

    2014-05-01

    In the present work, two-dimensional systems based on biodegradable polymers such as poly(ɛ-caprolactone) (PCL), poly(ethylene oxide) (PEO) and polylactic acid (PLA) are fabricated by means of a sustainable approach which consists in inducing phase separation in solutions of such polymers and "green" solvents, namely ethyl lactate (EL) and ethyl acetate (EA). The extraction of the solvent is promoted by a controlled drying process, which is performed in either air or supercritical CO2. The latter can indeed act as both an antisolvent, which favors the deposition of the polymer by forming a mixture with EL and EA, and a plasticizing agent, whose solvation and transport properties may considerably affect the microstructure and crystallinity of the polymer films. The morphological, topographical and crystalline properties of the films are tailored through a judicial selection of the materials and the processing conditions and assessed by means of thermal analyses, polarized optical microscopy, scanning electron microscopy and confocal interferometric microscopy. The results show that the morphological and crystalline properties of the films are strongly dependent on the choice of both the polymer/solvent system and the operating conditions during the drying step. In particular, the morphological, topographical and thermal properties of films prepared starting from highly crystalline polymers, namely PCL and PEO, are greatly affected by the crystallization of the material. Conversely, the less crystalline PLA forms almost completely amorphous films.

  15. Terminal sterilization of BisGMA-TEGDMA thermoset materials and their bioactive surfaces by supercritical CO2.

    Science.gov (United States)

    Donati, Ivan; Benincasa, Monica; Foulc, Marie-Pierre; Turco, Gianluca; Toppazzini, Mila; Solinas, Dario; Spilimbergo, Sara; Kikic, Ireneo; Paoletti, Sergio

    2012-04-09

    The development of biomaterials endowed with bioactive features relies on a simultaneous insight into a proper terminal sterilization process. FDA recommendations on sterility of biomaterials are very strict: a sterility assurance level (SAL) of 10(-6) must be guaranteed for biomaterials to be used in human implants. In the present work, we have explored the potential of supercritical CO(2) (scCO(2)) in the presence of H(2)O(2) as a low-temperature sterilization process for thermoset materials and their bioactive surfaces. Different conditions allowing for terminal sterilization have been screened and a treatment time-amount of H(2)O(2) relationship proposed. The selected terminal sterilization conditions did not notably modify the mechanical properties of the thermoset nor of their fiber-reinforced composites. This was confirmed by μCT analyses performed prior to and after the treatment. On the contrary, terminal sterilization in the presence of H(2)O(2) induced a slight decrease in the surface hardness. The treatment of the thermoset material with scCO(2) led to a reduction in the residual unreacted monomers content, as determined by means of high performance liquid chromatography (HPLC) analyses. Finally, it was found that a thermoset coated with a polysaccharide layer containing silver nanoparticles maintained a very high antimicrobial efficacy even after the scCO(2)-based terminal sterilization.

  16. Impact of supercritical CO2 injection on petrophysical and rock mechanics properties of chalk: an experimental study on chalk from South Arne field, North Sea

    DEFF Research Database (Denmark)

    Alam, Mohammad Monzurul; Hjuler, Morten Leth; Christensen, Helle Foged

    2011-01-01

    Changes in chalk due to EOR by injecting supercritical CO2 (CO2-EOR) can ideally be predicted by applying geophysical methods designed from laboratory-determined petrophysical and rock mechanics properties. A series of petrophysical and rock mechanics tests were performed on Ekofisk Formation...... and Tor Formation chalk of the South Arne field to reveal the changes in petrophysical and rock mechanics properties of chalk due to the injection of CO2 at supercritical state. An increase in porosity and decrease in specific surface was observed due to injection of supercritical CO2. This indicates...... that a reaction between CO2 enriched water and particles takes place which smoothens the particle surface. Accordingly, partial increase in permeability was also noticed. An effect is also observed from the decrease in pore-space stiffness, calculated from sonic velocity. No significant effect on wettability...

  17. A Conceptual Study on a Supercritical CO2-cooled KAIST Micro Modular Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yu, HwanYeal; Hartanto, Donny; Kim, Yonghee [KAIST, Daejeon (Korea, Republic of)

    2015-05-15

    Small Modular Reactors (SMRs) are nuclear reactors that are completely built in a factory and shipped to the designated site for installation. As such, the SMR is especially advantageous as a flexible and cost-effective energy source for remote and isolated areas. Furthermore, the concept requires a relatively low capital cost, which makes it attractive for developing countries with limited electricity grid. In addition, the SMR concepts also generate more interest after the Fukushima accident since it can easily be designed with a passive decay heat removal system. One of the major advantages of a water-cooled SMR is its relatively small core size. Nonetheless, in spite of its small core size, the volume and area required for its steam-cycle power conversion unit is still significant. In this study, neutronics feasibility of a fully compact and transportable KAIST micro-modular reactor (MMR) was demonstrated. Rated thermal power of the core was 36.2 MWth with total weight of about 39.6 tons. The core was loaded with 15.5 w/o uranium mono-nitride U15N fuels in order to achieve a targeted lifetime of 20 EFPYs. To achieve targeted lifetime, initial excess reactivity of the core should be quite high, around 4,707 pcm. To reduce the high excess reactivity to about 2,500 pcm, a replaceable burnable absorber was utilized in the design. As a result, the MMR has a 20-year lifetime with a relatively small burnup reactivity swing. Several important safety parameters of the KAIST MMR core were also determined in this study. The Doppler reactivity coefficients and CVRs were demonstrated to negative. Worth of the primary control drums and secondary control rod were much higher than initial excess reactivity.

  18. In Situ 13C and 23Na Magic Angle Spinning NMR Investigation of Supercritical CO2 Incorporation in Smectite-Natural Organic Matter Composites

    Energy Technology Data Exchange (ETDEWEB)

    Bowers, Geoffrey M.; Hoyt, David W.; Burton, Sarah D.; Ferguson, Brennan O.; Varga, Tamas; Kirkpatrick, Robert J.

    2014-01-29

    This paper presents an in situ NMR study of clay-natural organic polymer systems (a hectoritehumic acid [HA] composite) under CO2 storage reservoir conditions (90 bars CO2 pressure, 50°C). The 13C and 23Na NMR data show that supercritical CO2 interacts more strongly with the composite than with the base clay and does not react to form other C-containing species over several days at elevated CO2. With and without organic matter, the data suggest that CO2 enters the interlayer space of Na-hectorite equilibrated at 43% relative humidity. The presence of supercritical CO2 also leads to increased 23Na signal intensity, reduced line width at half height, increased basal width, more rapid 23Na T1 relaxation rates, and a shift to more positive resonance frequencies. Larger changes are observed for the hectorite-HA composite than for the base clay. In light of recently reported MD simulations of other polymer-Na-smectite composites, we interpret the observed changes as an increase in the rate of Na+ site hopping in the presence of supercritical CO2, the presence of potential new Na+ sorption sites when the humic acid is present, and perhaps an accompanying increase in the number of Na+ ions actively involved in site hopping. The results suggest that the presence of organic material either in clay interlayers or on external particle surfaces can significantly affect the behavior of supercritical CO2 and the mobility of metal ions in reservoir rocks.

  19. Formation of methotrexate-PLLA-PEG-PLLA composite microspheres by microencapsulation through a process of suspension-enhanced dispersion by supercritical CO2

    Directory of Open Access Journals (Sweden)

    Chen AZ

    2012-06-01

    Full Text Available Ai-Zheng Chen,1,2 Guang-Ya Wang,1 Shi-Bin Wang,1,2 Li Li,1 Yuan-Gang Liu,1,2 Chen Zhao11College of Chemical Engineering, 2Institute of Pharmaceutical Engineering, Institute of Biomaterials and Tissue Engineering, Huaqiao University, Xiamen 361021, ChinaBackground: The aim of this study was to improve the drug loading, encapsulation efficiency, and sustained-release properties of supercritical CO2-based drug-loaded polymer carriers via a process of suspension-enhanced dispersion by supercritical CO2 (SpEDS, which is an advanced version of solution-enhanced dispersion by supercritical CO2 (SEDS.Methods: Methotrexate nanoparticles were successfully microencapsulated into poly (L-lactide-poly(ethylene glycol-poly(L-lactide (PLLA-PEG-PLLA by SpEDS. Methotrexate nanoparticles were first prepared by SEDS, then suspended in PLLA-PEG-PLLA solution, and finally microencapsulated into PLLA-PEG-PLLA via SpEDS, where an "injector" was utilized in the suspension delivery system.Results: After microencapsulation, the composite methotrexate (MTX-PLLA-PEG-PLLA microspheres obtained had a mean particle size of 545 nm, drug loading of 13.7%, and an encapsulation efficiency of 39.2%. After an initial burst release, with around 65% of the total methotrexate being released in the first 3 hours, the MTX-PLLA-PEG-PLLA microspheres released methotrexate in a sustained manner, with 85% of the total methotrexate dose released within 23 hours and nearly 100% within 144 hours.Conclusion: Compared with a parallel study of the coprecipitation process, microencapsulation using SpEDS offered greater potential to manufacture drug-loaded polymer microspheres for a drug delivery system.Keywords: drug loading, encapsulation efficiency, methotrexate, nanoparticles, poly(L-lactide, supercritical CO2 sustained release

  20. Advance in Polymer Modifications by Supercritical CO2%超临界CO2在聚合物改性中的应用

    Institute of Scientific and Technical Information of China (English)

    张爱丰; 张子勇

    2003-01-01

      综述了超临界CO2在聚合物改性中的研究进展。用超临界CO2作为介质进行聚合物改性的途径包括:挤出共混、聚合共混、与小分子复合、接枝、交联以及表面改性等。采用不同的改性方法,可制备具有各种不同性能的高分子材料。超临界CO2作为一种绿色反应介质,将在聚合物改性方面发挥巨大的作用。%  Advance in polymer modifications by supercritical CO2 was reviewed. The methods of polymer modifications by using supercritical CO2 medium include the blend by extruding or impregnating, composite with small molecules, cross-linking, grafting and surface refinement and so on. Various different ways were used to prepare polymer materials with special properties. Supercritical CO2, as a green medium, should play an important role in the polymer modifications.

  1. 超临界CO2辅助聚合物加工%Supercritical CO2 assisted polymer processing

    Institute of Scientific and Technical Information of China (English)

    赵玲; 刘涛

    2013-01-01

    近年来,以超临界CO2替代聚合物加工过程中大量使用的有机溶剂实现超临界CO2辅助聚合物加工过程已引起人们越来越多的关注.CO2在聚合物中的溶解扩散可导致其结构和形态的变化,能够溶胀增塑聚合物并且将溶解于其中的小分子物质携带输运到聚合物基体中,进而影响聚合物的结晶及晶型转变行为,聚合物/CO2体系界面张力以及聚合物/CO2体系流变行为等基本物性的变化.利用聚合物基本物性的变化可实现CO2辅助聚合物接枝反应,CO2辅助聚合物渗透小分子物质以及CO2辅助聚合物发泡等超临界CO2辅助聚合物加工过程的应用.结合本研究室的实例,探讨了CO2作用下等规聚丙烯和间规聚丙烯的结晶行为以及一种多晶型聚合物——等规聚丁烯-1的晶型转变行为;探讨了利用CO2对等规聚丙烯、聚乳酸和聚酯三种典型的低熔体强度结晶聚合物具有的不同诱导结晶作用,调控聚合物的结晶行为,使其具备发泡所需的熔体强度,制备了具有不同结构特征的发泡聚合物材料.%The use of CO2 for substituting volatile organic compounds in polymer processing, i. e. , supercritical CO2-assisted polymer processing, has attracted increasing attention in recent years. Dissolution of CO2 in polymer could swell, plasticize and deliver small molecules into the polymer matrixes. Consequently, the structure and morphology of the polymer would change, as well as the fundamental properties, including polymer crystallization, interfacial tension between polymer and gas, and rheology of CO2 /polymers melt. CO2 -induced changes in these properties could be used to realize the supercritical CO2-assisted polymer processing, e.g., CO2-assisted polymer grafting, CO2-assisted penetrating of small molecules into polymer and CO2-assisted polymer foaming. Several cases from the authors' laboratory are presented for elucidating how to use the changes to manipulate

  2. Therapeutic Effect of Supercritical CO2 Extracts of Curcuma Species with Cancer Drugs in Rhabdomyosarcoma Cell Lines.

    Science.gov (United States)

    Ramachandran, Cheppail; Quirin, Karl-W; Escalon, Enrique A; Lollett, Ivonne V; Melnick, Steven J

    2015-08-01

    Synergistic effect of supercritical CO2 extracts of Curcuma species with conventional chemotherapeutic drugs was investigated in human alveolar (SJRH30) and embryonal (RD) rhabdomyosarcoma cell lines. The Curcuma amada (mango ginger) (CA) extract showed the highest levels of cytotoxicity with inhibitory concentration IC50 values of 7.133 µg/ml and 7.501 µg/ml for SJRH30 and RD cell lines, respectively, as compared with Curcuma longa (turmeric) and Curcuma xanthorrhiza (Javanese turmeric) extracts. CA showed synergistic cytotoxic effects with vinblastine (VBL) and cyclophosphamide (CP) as indicated by the combination index values of <1 for VBL + CA, CP + CA, and VBL + CP + CA combinations in both embryonal and alveolar rhabdomyosarcomas. When lower doses of CA (0.1-0.2 µg/ml) were combined with cancer drugs like CP and VBL, caspase-3 activity increased significantly compared with individual agents and correlated with the percentage of apoptotic cells. CA in combination with VBL and CP induced a higher percentage of apoptosis than single agents in both cell lines. CA also modulated the expression of genes associated with intrinsic pathway of apoptosis (Bcl-2, Bax, Bak, and p53) and also inhibited the expression of genes associated with inflammation such as COX-2 and NF-κB. Xenograft studies with SJRH30 tumors in nude mice showed that CA treatment inhibited tumor growth rate with and without VBL and increased the survival rate significantly. These results suggest that CA can be evaluated further as an adjuvant with cancer drugs for the treatment of rhabdomyosarcoma patients. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  3. Determination of extraction conditions of Ginkgo biloba L. leaves by supercritical CO2 using response surface methodology

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    Milošević Svetlana G.

    2011-01-01

    Full Text Available The effects of process parameters on the extraction of Ginkgo biloba L. leaves with supercritical carbon dioxide were investigated. The investigated parameters include particle size (mean particle diameter 0.19, 0.467 and 1.009 mm, solvent flow rate (1.5810-3, 3.2210-3 and 4.1610-3 kg CO2/min and pressure (100-300 bar, which were obtained by the response surface methodology (RSM under the following condition ranges: temperature 40-50-60ºC, pressure 100-140-180 bar and extraction time of 2-3-4 h at the flow rate of 3.2210-3 kg/min. Based on the experimental results of kinetics of Ginkgo biloba leaves extraction with supercritical carbon dioxide, modeling of the extraction system of Ginkgo biloba-supercritical CO2 was done. Two mathematical models (Reverchon-Sesti Osseo and Sovová were applied to correlate the experimental data. RSM was applied to optimize the process parameters of supercritical carbon dioxide extraction of Ginkgo biloba L. leaves. A second-order polynomial response surface equation was developed indicating the effect of variables on Ginkgo biloba extraction yield. The statistical analysis of the experiment indicated that pressure (X1, extraction time (X3, the quadratic of temperature (X22, and the interaction between pressure and extraction time (X1X3, show significant effect on the extraction yield. The results showed that the data were adequately fitted into the second-order polynomial model. It was predicted that the optimum extraction process parameters within the experimental ranges would be the extraction temperature of 52.7ºC, the pressure of 184.4 bar, and the extraction time of 3.86 h. Under these conditions, the predicted extraction yield is 2.39% (g/100 g drug.

  4. Chemical Processes with Supercritical CO2 in Engineered Geologic Systems: Significance, Previous Study, and Path Forward (Invited)

    Science.gov (United States)

    Xu, T.; Pruess, K.

    2009-12-01

    Chemical reactions with dissolved CO2 in the aqueous phase have long been considered in fundamental geosciences and practical applications. Recently, studies on geologic carbon sequestration and enhanced geothermal systems using CO2 as heat transmission fluid have brought new interests in chemical reaction processes directly with supercritical CO2 (scCO2, or gas phase). In the vicinity of a CO2 injection well, the aqueous fluid initially present in a geological formation would be quickly removed by dissolution (evaporation) into the flowing gas stream and by immiscible displacement by the scCO2, creating a gas phase dominant zone. In this zone, the water evaporation could cause formation dry-out and precipitation of salt near the injection well, reducing formation porosity, permeability, and injectivity. The scCO2 may directly attack well construction materials such as cement. Over time, the gas phase will tend to migrate upwards towards the caprock because the density of the scCO2 is lower than that of the aqueous phase. In the upper portions of the reservoir, the scCO2 will directly react with caprock minerals and alter the hydrological properties and mechanical strength. On the other hand, the scCO2 phase will maintain the dissolution into the aqueous phase, lowering pH, inducing mineral dissolution, complexing with dissolved cations, increasing CO2 solubility, increasing the density of the aqueous phase, and promoting “convective mixing”. Chemical processes are quite different in the scCO2 dominant geologic systems. The absence of an aqueous phase poses unique questions, as little is presently known about the chemistry of non-aqueous systems. Additional issues arise from the reactivity of water that is dissolved in the ScCO2 phase. In this presentation, the author will discuss the importance, state of the studies performed, and future research directions.

  5. Supercritical CO2 Foaming of Thermoplastic Materials Derived from Maize: Proof-of-Concept Use in Mammalian Cell Culture Applications

    Science.gov (United States)

    Trujillo-de Santiago, Grissel; Portales-Cabrera, Cynthia Guadalupe; Portillo-Lara, Roberto; Araiz-Hernández, Diana; Del Barone, Maria Cristina; García-López, Erika; Rojas-de Gante, Cecilia; de los Angeles De Santiago-Miramontes, María; Segoviano-Ramírez, Juan Carlos; García-Lara, Silverio; Rodríguez-González, Ciro Ángel; Alvarez, Mario Moisés; Di Maio, Ernesto; Iannace, Salvatore

    2015-01-01

    Background Foams are high porosity and low density materials. In nature, they are a common architecture. Some of their relevant technological applications include heat and sound insulation, lightweight materials, and tissue engineering scaffolds. Foams derived from natural polymers are particularly attractive for tissue culture due to their biodegradability and bio-compatibility. Here, the foaming potential of an extensive list of materials was assayed, including slabs elaborated from whole flour, the starch component only, or the protein fraction only of maize seeds. Methodology/Principal Findings We used supercritical CO2 to produce foams from thermoplasticized maize derived materials. Polyethylene-glycol, sorbitol/glycerol, or urea/formamide were used as plasticizers. We report expansion ratios, porosities, average pore sizes, pore morphologies, and pore size distributions for these materials. High porosity foams were obtained from zein thermoplasticized with polyethylene glycol, and from starch thermoplasticized with urea/formamide. Zein foams had a higher porosity than starch foams (88% and 85%, respectively) and a narrower and more evenly distributed pore size. Starch foams exhibited a wider span of pore sizes and a larger average pore size than zein (208.84 vs. 55.43 μm2, respectively). Proof-of-concept cell culture experiments confirmed that mouse fibroblasts (NIH 3T3) and two different prostate cancer cell lines (22RV1, DU145) attached to and proliferated on zein foams. Conclusions/Significance We conducted screening and proof-of-concept experiments on the fabrication of foams from cereal-based bioplastics. We propose that a key indicator of foamability is the strain at break of the materials to be foamed (as calculated from stress vs. strain rate curves). Zein foams exhibit attractive properties (average pore size, pore size distribution, and porosity) for cell culture applications; we were able to establish and sustain mammalian cell cultures on zein

  6. Optimisation of biological and physical parameters for lycopene supercritical CO2 extraction from ordinary and high-pigment tomato cultivars.

    Science.gov (United States)

    Lenucci, Marcello S; Caccioppola, Alessandro; Durante, Miriana; Serrone, Lucia; Leonardo, Rescio; Piro, Gabriella; Dalessandro, Giuseppe

    2010-08-15

    Lycopene is used for several industrial applications. Supercritical CO(2) (SC-CO(2)) extraction from red-ripe tomato fruits is an excellent technique to replace the use of harmful solvents. In this study, starting from red-ripe tomatoes of ordinary and high-lycopene cultivars, the effect of different agronomical and technical aspects on lycopene content, stability and yield was evaluated throughout the production process from fresh tomatoes to the final SC-CO(2)-extracted oleoresin containing lycopene. Red-ripe tomato cultivars differed in their lycopene content. Irrigation excess or deficit caused an increase in the amount of lycopene in the fruits. Fresh tomatoes were processed into a lyophilised matrix suitable for SC-CO(2) extraction, which could be stored for more than 6 months at -20 degrees C without lycopene loss. Under the optimal extraction conditions, efficiencies of up to 80% were achieved, but the recovery of lycopene in the extracted oleoresin was very low (approximately 24%). Co-extraction of the tomato matrix mixed with a lipid co-matrix allowed the recovery of approximately 90% of lycopene in the oleoresin. Using the high-lycopene cultivars, the yield of total extracted lycopene increased by approximately 60% with respect to the ordinary cultivars. Lipids and other biologically active molecules were present in the oleoresin. A method for extracting, from a tomato matrix, a natural and solvent-free oleoresin containing lycopene dissolved in a highly unsaturated vegetable oil has been described. The oleoresin represents an excellent product for testing on cancer and cardiovascular disease prevention. Copyright (c) 2010 Society of Chemical Industry.

  7. Supercritical CO2 foaming of thermoplastic materials derived from maize: proof-of-concept use in mammalian cell culture applications.

    Directory of Open Access Journals (Sweden)

    Grissel Trujillo-de Santiago

    Full Text Available Foams are high porosity and low density materials. In nature, they are a common architecture. Some of their relevant technological applications include heat and sound insulation, lightweight materials, and tissue engineering scaffolds. Foams derived from natural polymers are particularly attractive for tissue culture due to their biodegradability and bio-compatibility. Here, the foaming potential of an extensive list of materials was assayed, including slabs elaborated from whole flour, the starch component only, or the protein fraction only of maize seeds.We used supercritical CO2 to produce foams from thermoplasticized maize derived materials. Polyethylene-glycol, sorbitol/glycerol, or urea/formamide were used as plasticizers. We report expansion ratios, porosities, average pore sizes, pore morphologies, and pore size distributions for these materials. High porosity foams were obtained from zein thermoplasticized with polyethylene glycol, and from starch thermoplasticized with urea/formamide. Zein foams had a higher porosity than starch foams (88% and 85%, respectively and a narrower and more evenly distributed pore size. Starch foams exhibited a wider span of pore sizes and a larger average pore size than zein (208.84 vs. 55.43 μm2, respectively. Proof-of-concept cell culture experiments confirmed that mouse fibroblasts (NIH 3T3 and two different prostate cancer cell lines (22RV1, DU145 attached to and proliferated on zein foams.We conducted screening and proof-of-concept experiments on the fabrication of foams from cereal-based bioplastics. We propose that a key indicator of foamability is the strain at break of the materials to be foamed (as calculated from stress vs. strain rate curves. Zein foams exhibit attractive properties (average pore size, pore size distribution, and porosity for cell culture applications; we were able to establish and sustain mammalian cell cultures on zein foams for extended time periods.

  8. Reaction of water-saturated supercritical CO2 with forsterite: Evidence for magnesite formation at low temperatures

    Science.gov (United States)

    Felmy, Andrew R.; Qafoku, Odeta; Arey, Bruce W.; Hu, Jian Zhi; Hu, Mary; Todd Schaef, H.; Ilton, Eugene S.; Hess, Nancy J.; Pearce, Carolyn I.; Feng, Ju; Rosso, Kevin M.

    2012-08-01

    The nature of the reaction products that form on the surfaces of nanometer-sized forsterite particles during reaction with H2O-saturated supercritical CO2 (scCO2) at 35 °C and 50 °C were examined under in situ conditions and ex situ following reaction. The in situ analysis was conducted by X-ray diffraction (XRD). Ex situ analysis consisted of scanning electron microscopy (SEM) examination of the surface phases and chemical characterization of precipitates using a combination of confocal Raman spectroscopy, 13C and 29Si NMR spectroscopy, and energy-dispersive X-ray spectroscopy (EDS). The results show that the forsterite surface is highly reactive with the primary reaction products being a mixture of nesquehonite (MgCO3·3H2O) and magnesite (MgCO3) at short reaction times (˜3-4 days) and then magnesite (MgCO3) and a highly porous amorphous silica phase at longer reaction times (14 days). After 14 days of reaction most of the original forsterite transformed to reaction products. Importantly, the formation of magnesite was observed at temperatures much lower (35 °C) than previously thought needed to overcome its well-known sluggish precipitation kinetics. The conversion of nesquehonite to magnesite liberates H2O which can potentially facilitate further metal carbonation, as postulated by previous investigators, based upon studies at higher temperature (80 °C). The observation that magnesite can form at lower temperatures implies that water recycling may also be important in determining the rate and extent of mineral carbonation in a wide range of potential CO2 storage reservoirs.

  9. Reaction of Water-Saturated Supercritical CO2 with Forsterite: Evidence for Magnesite Formation at Low Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Felmy, Andrew R.; Qafoku, Odeta; Arey, Bruce W.; Hu, Jian Z.; Hu, Mary Y.; Schaef, Herbert T.; Ilton, Eugene S.; Hess, Nancy J.; Pearce, Carolyn I.; Feng, Ju; Rosso, Kevin M.

    2012-08-01

    The nature of the reaction products that form on the surfaces of nanometer-sized forsterite particles during reaction with H2O saturated supercritical CO2 (scCO2) at 35 C and 50 C were examined under in situ conditions and ex situ following reaction. The in situ analysis was conducted by X-ray diffraction (XRD). Ex situ analysis consisted of scanning electron microscopy (SEM) examination of the surface phases and chemical characterization of precipitates using a combination of confocal Raman spectroscopy, 13C and 29Si NMR spectroscopy, and energy-dispersive X-ray Spectroscopy (EDS). The results show that the forsterite surface is highly reactive with the primary reaction products being a mixture of nesquehonite (MgCO3.3H2O) and magnesite (MgCO3) at short reaction times ({approx}3-4 days) and then magnesite (MgCO3) and a highly porous amorphous silica phase at longer reaction times (14 days). After 14 days of reaction most of the original forsterite transformed to reaction products. Importantly, the formation of magnesite was observed at temperatures much lower (35 C) than previously thought needed to overcome its well known sluggish precipitation kinetics. The conversion of nesquehonite to magnesite liberates H2O which can potentially facilitate further metal carbonation, as postulated by previous investigators, based upon studies at higher temperature (80 C). The observation that magnesite can form at lower temperatures implies that water recycling may also be important in determining the rate and extent of mineral carbonation in a wide range of potential CO2 storage reservoirs.

  10. Isolation of Organochlorine Pesticide from Ginseng with Supercritical CO2%超临界流体萃取脱除人参中痕量有机氯农药

    Institute of Scientific and Technical Information of China (English)

    李淑芬; 王幼君; 全灿; 田松江

    2005-01-01

    The feasibility of removal of the organochlorine pesticides residues of hexachlorocyclohexane(BHC)from radix ginseng with supercritical CO2 was explored. Some factors, such as extraction pressure, extraction temperature, and kinds of co-solvents were investigated. The experimental results indicate that it is possible to reduce BHC residues in radix ginseng to the level of 0.1 × 10-6 with supercritical CO2 in the presence of suitable amount of co-solvent, such as water.

  11. Experimental methods for the simulation of supercritical CO2 injection at laboratory scale aimed to investigate capillary trapping

    Science.gov (United States)

    Trevisan, L.; Illangasekare, T. H.; Rodriguez, D.; Sakaki, T.; Cihan, A.; Birkholzer, J. T.; Zhou, Q.

    2011-12-01

    Geological storage of carbon dioxide in deep geologic formations is being considered as a technical option to reduce greenhouse gas loading to the atmosphere. The processes associated with the movement and stable trapping are complex in deep naturally heterogeneous formations. Three primary mechanisms contribute to trapping; capillary entrapment due to immobilization of the supercritical fluid CO2 within soil pores, liquid CO2 dissolving in the formation water and mineralization. Natural heterogeneity in the formation is expected to affect all three mechanisms. A research project is in progress with the primary goal to improve our understanding of capillary and dissolution trapping during injection and post-injection process, focusing on formation heterogeneity. It is expected that this improved knowledge will help to develop site characterization methods targeting on obtaining the most critical parameters that capture the heterogeneity to design strategies and schemes to maximize trapping. This research combines experiments at the laboratory scale with multiphase modeling to upscale relevant trapping processes to the field scale. This paper presents the results from a set of experiments that were conducted in an intermediate scale test tanks. Intermediate scale testing provides an attractive alternative to investigate these processes under controlled conditions in the laboratory. Conducting these types of experiments is highly challenging as methods have to be developed to extrapolate the data from experiments that are conducted under ambient laboratory conditions to high temperatures and pressures settings in deep geologic formations. We explored the use of a combination of surrogate fluids that have similar density, viscosity contrasts and analogous solubility and interfacial tension as supercritical CO2-brine in deep formations. The extrapolation approach involves the use of dimensionless numbers such as Capillary number (Ca) and the Bond number (Bo). A set of

  12. In-situ Optical Spectroscopy Investigation of Water and Its influence on Forsterite Transformation in Supercritical CO2

    Science.gov (United States)

    Wang, Z.; Thompson, C. J.; Joly, A. G.; Sklarew, D. S.; Poindexter, L.; Rosso, K. M.

    2009-12-01

    Carbon capture and sequestration (CCS) from coal/gas-burning power plants is currently viewed as one of the most promising technologies for mitigating green house gas emissions. This strategy involves injection of supercritical CO2 (scCO2) into deep geological formations such as depleted oil and gas reservoirs and deep saline aquifers. The feasibility of this approach and the ultimate fate of the stored CO2 are determined by the interactions between scCO2, various minerals in the rock formations, and the host fluids. Currently, there is only limited knowledge about both the thermodynamic and kinetic aspects of the physical and chemical processes that occur between scCO2 and relevant minerals, such as metal silicates and metal aluminosilicates, and the role of water activity for catalyzing mineral transformation reactions. In this work, we have developed a modular in situ optical spectroscopic platform that integrates a scCO2 generation and manipulation system with an array of optical and laser spectroscopies including UV-visible, IR, Raman and laser fluorescence spectroscopy. We have used the system to study i) the dissolution and quantification of H2O/D2O in scCO2 and ii) interaction between scCO2 and a model metal silicate, forsterite (Mg2SiO4), and the effects of the presence of water under variable pressure, temperature and water content. Our results showed that H2O and D2O have unique IR spectral features over a broad spectral range from 700 cm-1 to ~ 2900 cm-1 in scCO2 and their concentrations are directly proportional to the characteristic IR bands that correspond to their stretching (D2O) and bending frequencies (both D2O and H2O). These bands offer a unique spectroscopic signature useful for qualitative and quantitative analysis of the properties and reactivity of small amounts of H2O in scCO2.

  13. Supercritical CO2 Extraction of Lavandula angustifolia Mill. Flowers: Optimisation of Oxygenated Monoterpenes, Coumarin and Herniarin Content.

    Science.gov (United States)

    Jerković, Igor; Molnar, Maja; Vidović, Senka; Vladić, Jelena; Jokić, Stela

    2017-07-14

    Lavandula angustifolia is good source of oxygenated monoterpenes containing coumarins as well, which are all soluble in supercritical CO2 (SC-CO2 ). The study objective is to investigate SC-CO2 extraction parameters on: the total yield; GC-MS profile of the extracts; relative content of oxygenated monoterpenes; the amount of coumarin and herniarin; and to determine optimal SC-CO2 extraction conditions by response surface methodology (RSM). SC-CO2 extraction was performed under different pressure, temperature and CO2 flow rate determined by Box-Behnken design (BBD). The sample mass and the extraction time were kept constant. The chemical profiles and relative content of oxygenated monoterpenes (as coumarin equivalents, CE) were determined by GC-MS. Coumarin and herniarin concentrations were dosed by HPLC. SC-CO2 extracts contained linalool (57.4-217.9 mg CE/100 g), camphor (10.6-154.4 mg CE/100 g), borneol (6.2-99.9 mg CE/100 g), 1,8-cineole (5.0-70.4 mg CE/100 g), linalyl acetate (86.1-267.9 mg CE/100 g), coumarin (0.95-18.16 mg/100 g), and herniarin (0.95-13.63 mg/100 g). The interaction between the pressure and CO2 flow rate as well as between the temperature and CO2 flow rate showed statistically significant influence on the extraction yield. Applying BBD, the optimum extraction conditions for higher monoterpenes and lower coumarin content were at 10 MPa, 41°C and CO2 flow rate 2.3 kg/h, and at 30 MPa, 50°C and CO2 flow rate 3 kg/h for higher monoterpenes and coumarin content. SC-CO2 extraction is a viable technique for obtaining lavender extracts with desirable flavour components. The second-order model based on BBD predicts the results for SC-CO2 extraction quite satisfactorily. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  14. Measuring water adsorption on mineral surfaces in air, CO2, and supercritical CO2 with a quartz-crystal microbalance

    Science.gov (United States)

    Bryan, C. R.; Wells, R. K.; Burton, P. D.; Heath, J. E.; Dewers, T. A.; Wang, Y.

    2011-12-01

    Carbon sequestration via underground storage in geologic formations is a proposed approach for reducing industrial CO2 emissions. However, current models for carbon injection and long-term storage of supercritical CO2 (scCO2) do not consider the development and stability of adsorbed water films at the scCO2-hydrophilic mineral interface. The thickness and properties of the water films control the surface tension and wettability of the mineral surface, and on the core scale, affect rock permeability, saturation, and capillary properties. The film thickness is strongly dependent upon the activity of water in the supercritical fluid, which will change as initially anhydrous scCO2 absorbs water from formation brine. As described in a companion paper by the coauthors, the thickness of the adsorbed water layer is controlled by the disjoining pressure; structural and van der Waals components dominate at low water activity, while electrostatic forces become more important with increasing film thickness (higher water activities). As scCO2 water activity and water layer thickness increase, concomitant changes in mineral surface properties and reservoir/caprock hydrologic properties will affect the mobility of the aqueous phase and of scCO2. Moreover, the development of a water layer may be critical to mineral dissolution reactions in scCO2. Here, we describe the use of a quartz-crystal microbalance (QCM) to monitor adsorption of water by mineral surfaces. QCMs utilize a piezoelectrically-stimulated quartz wafer to measure adsorbed or deposited mass via changes in vibrational frequency. When used to measure the mass of adsorbed liquid films, the frequency response of the crystal must be corrected for the viscoelastic, rather than elastic, response of the adsorbed layer. Results are presented for adsorption to silica in N2 and CO2 at one bar, and in scCO2. Additional data are presented for water uptake by clays deposited on a QCM wafer. In this case, water uptake occurs by the

  15. Dispersion and deagglomerat1on of nano-SiO2 particles with a silane modification reagent in supercritical CO2

    Directory of Open Access Journals (Sweden)

    Stojanović Dušica B.

    2007-01-01

    Full Text Available The supercritical CO2 method was used in order to perform deagglomeration and improve the dispersion of nano-SiO2 particles. γ-Met-hacryloxypropyltrimethoxysilane was used as the surface modification reagent. The conventional method for coating nano-SiO2 particles was used as the comparison method. Considerable improvement of the dispersion and deagglomeration was found using supercritical CO2. Analysis of the TEM micrographs and DLS results showed the reduction of the average size of the agglomerates with the silane coupling reagent. Thermogravimetric analysis (TGA showed that the particles treated in super­critical CO2 were more thermally stable than particles treated by conventional method. Encapsulation of several particles coated with the silane coupling reagent was observed in certain parts of the primary particles. A chemical reaction takes place between the modification reagent, MEMO silane, and active hydroxyl groups on the surface of the nano-SiO2 particles. A larger quantity of MEMO silane reacted using the con­ventional method instead of the supercritical method. On the other hand, the reacted silane molecules were better arranged around the particle surface in the supercritical method because of the formation of covalent or self-assembled structures. Polycondensed structures were preferentially obtained in the conventional method. This was achieved by using supercritical CO2, which has a high solvating power such as organic solvents and physical properties (low viscosity, low surface tension and high diffusion coefficient similar to gases on the other side. These properties enable the sufficient and uniform wettability of nano-SiO2 particle surfaces. These results are important for obtaining nanofillers with improved dispersion and polymer wettability. Such nanofillers can be used to obtain composite materials with considerably improved mechanical characteristics.

  16. Determination of the potency of a novel saw palmetto supercritical CO2 extract (SPSE for 5α-reductase isoform II inhibition using a cell-free in vitro test system

    Directory of Open Access Journals (Sweden)

    Pais P

    2016-04-01

    Full Text Available Pilar Pais, Agustí Villar, Santiago Rull Euromed, Barcelona, Spain Background: The nicotinamide adenine dinucleotide phosphate-dependent membrane protein 5α-reductase catalyses the conversion of testosterone to the most potent androgen – 5α-dihydrotestosterone. Two 5α-reductase isoenzymes are expressed in humans: type I and type II. The latter is found primarily in prostate tissue. Saw palmetto extract (SPE has been used extensively in the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH. The pharmacological effects of SPE include the inhibition of 5α-reductase, as well as anti-inflammatory and antiproliferative effects. Clinical studies of SPE have been inconclusive – some have shown significant results, and others have not – possibly the result of varying bioactivities of the SPEs used in the studies. Purpose: To determine the in vitro potency in a cell-free test system of a novel SP supercritical CO2 extract (SPSE, an inhibitor of the 5α-reductase isoenzyme type II. Materials and methods: The inhibitory potency of SPSE was compared to that of finasteride, an approved 5α-reductase inhibitor, on the basis of the enzymatic conversion of the substrate androstenedione to the 5α-reduced product 5α-androstanedione. Results: By concentration-dependent inhibition of 5α-reductase type II in vitro (half-maximal inhibitory concentration 3.58±0.05 µg/mL, SPSE demonstrated competitive binding toward the active site of the enzyme. Finasteride, the approved 5α-reductase inhibitor tested as positive control, led to 63%–75% inhibition of 5α-reductase type II. Conclusion: SPSE effectively inhibits the enzyme that has been linked to BPH, and the amount of extract required for activity is comparatively low. It can be confirmed from the results of this study that SPSE has bioactivity that promotes prostate health at a level that is superior to that of many other phytotherapeutic extracts. The

  17. Extraction of rare earth elements from their oxides using organophosphorus reagent complexes with HNO_3 and H_2O in supercritical CO_2

    Institute of Scientific and Technical Information of China (English)

    段五华; 曹丕佳; 朱永(贝睿)

    2010-01-01

    Direct extraction of metals from solids with complexing agents in supercritical CO2(SC-CO2) has recently attracted interests in separation,purification,recovery,and analysis of metals.In the present study,the static/dynamic extraction of rare earth elements(Nd,Ce) from their oxides(Nd2O3,CeO2) with organophosphorus complexes with HNO3 and H2O in SC-CO2 was investigated.The static extraction efficiency of Nd from Nd2O3 with the tri-n-butylphosphate(TBP)-HNO3 complex could reach 95% under optimized experiment...

  18. Genomic insights into growth and survival of supercritical-CO2 tolerant bacterium MIT0214 under conditions associated with geologic carbon dioxide sequestration

    Science.gov (United States)

    Peet, K. C.; Freedman, A. J.; Hernandez, H.; Thompson, J. R.

    2011-12-01

    Carbon capture and storage (CCS) of CO2 has the potential to significantly reduce the emissions of greenhouse gasses associated with fossil fuel combustion. The largest potential for storing captured CO2 in the United Sates is in deep geologic saline formations. Currently, little is known about the effects of CO2 storage on biologically active microbial communities found in the deep earth biosphere. Therefore, to investigate how deep earth microbial communities will be affected by the storage of CO2 we have enriched for a microbial consortium from the saline formation waters of the Frio 2 project site (Texas Gulf Coast) that is capable of growth in nutrient media under a supercritical CO2 headspace (Hernandez, et al). The cultivation of actively growing cells in an environment containing scCO2 is unexpected based on previous experimental evidence of microbial sterilization attributed to the acidic, desiccating, and solvent-like properties of scCO2. We have isolated strain MIT0214 from this supercritical CO2 based enrichment and have sequenced its genome using the Illumina platform followed by de novo assembly of reads and targeted Sanger sequencing to reduce gaps in the draft assembly. The genome of strain MIT0214 is approximately 5,551,062 base pairs with 35% GC-content and is most similar to nonpathogenic Bacillus cereus strain ATCC 14597. Annotation of the draft assembly of the MIT0214 genome by the Rapid Annotation using Subsystem Technology (RAST) server revealed 5538 coding sequences where 4145 of the coding sequences were assigned putative functions. These functions were enriched in cell wall and capsule formation, phage/prophage and plasmids, gene regulation and signaling, and nitrogen and sulfur metabolism relative to the genome of the most closely-related surface-isolated B. cereus reference (ATCC 14597) and in total 773,416 bp of the MIT0214 genome content was distinct from the B. cereus reference. Notably, this set of distinct sequences were most

  19. Etchant solutions for the removal of Cu(0) in a supercritical CO2-based "dry" chemical mechanical planarization process for device fabrication.

    Science.gov (United States)

    Bessel, Carol A; Denison, Ginger M; DeSimone, Joseph M; DeYoung, James; Gross, Stephen; Schauer, Cynthia K; Visintin, Pamela M

    2003-04-30

    The microelectronics industry is focused on increasing chip complexity, improving the density of electron carriers, and decreasing the dimensions of the interconnects into the sub-0.25 mum regime while maintaining high aspect ratios. Water-based chemical mechanical planarization or polishing (CMP) faces several technical and environmental challenges. Condensed CO2 has significant potential for replacing current CMP solvents as a "dry" etching medium because of its unique properties. In working toward a condensed CO2-based CMP process, we have successfully investigated the oxidation and chelation of solid copper metal in liquid and supercritical CO2 using ethyl peroxydicarbonate and a beta-diketone chelating agent.

  20. [Optimize the extraction process with supercritical CO2 fluid from lotus leaves by the uniform design and analysis on the chemical constituents by GC-MS].

    Science.gov (United States)

    Yin, Hui-jing; Qian, Yi-fan; Pu, Cun-hai

    2007-04-01

    To study the optimum parameters of the supercritical CO, fluid extraction of lotus leaves and chemical constituents of extractive matters. Supercritical CO2 fluid extraction condition was selected by uniform design. The extraction pressure, extraction temperature, extraction time were three factors in the experiment. GC-MS was applied for analyzing the extraction. The optimum condition were obtained: the extraction pressure was 26 Mpa, the extraction temperature was 40 degrees C, the extracion time was 90 minutes. The major constituent was 1H-Pyrrole-2-carboxaldehyde, 1-ethyl-in extractive matters. Uniform design can optimize the CO2 Supercritical Fluid Extraction process quickly and accuratly with satisfactory results.

  1. Investigation of Wyoming Bentonite Hydration in Dry to Water-Saturated Supercritical CO2: Implications for Caprock Integrity

    Science.gov (United States)

    Loring, J. S.; Chen, J.; Thompson, C.; Schaef, T.; Miller, Q. R.; Martin, P. F.; Ilton, E. S.; Qafoku, O.; Felmy, A. R.; Rosso, K. M.

    2012-12-01

    The effectiveness of geologic sequestration as an enterprise for CO2 storage depends partly on the reactivity of supercritical CO2 (scCO2) with caprock minerals. Injection of scCO2 will displace formation water, and the pore space adjacent to overlying caprocks could eventually be dominated by dry to water-saturated scCO2. Caprock formations have high concentrations of clay minerals, including expandable montmorillonites. Water-bearing scCO2 is highly reactive and capable of hydrating or dehydrating clays, possibly leading to porosity and permeability changes that directly impact caprock performance. Dehydration will cause montmorillonite clay minerals in caprocks to contract, thereby decreasing solid volume and possibly increasing caprock permeability and porosity. On the other hand, water intercalation will cause these clays to expand, thereby increasing solid volume and possibly leading to self-sealing of caprock fractures. Pacific Northwest National Laboratory's Carbon Sequestration Initiative is developing capabilities for studying wet scCO2-mineral reactions in situ. Here, we introduce novel in situ infrared (IR) spectroscopic instrumentation that enables quantitative titrations of reactant minerals with water in scCO2. Results are presented for the infrared spectroscopic titrations of Na-, Ca-, and Mg-saturated Wyoming betonites with water over concentrations ranging from zero to scCO2 saturated. These experiments were carried out at 50°C and 90 bar. Transmission IR spectroscopy was used to measure concentrations of water dissolved in the scCO2 or intercalated into the clays. The titration curves evaluated from the transmission-IR data are compared between the three types of clays to assess the effects of the cation on water partitioning. Single-reflection attenuated total reflection (ATR) IR spectroscopy was used to collect the spectrum of the clays as they hydrate at every total water concentration during the titration. Clay hydration is evidenced by

  2. Preparation of Poly-(Methyl vinyl ether-co-maleic Anhydride Nanoparticles by Solution-Enhanced Dispersion by Supercritical CO2

    Directory of Open Access Journals (Sweden)

    Yong-Qiang Kang

    2012-10-01

    Full Text Available The supercritical CO2-based technologies have been widely used in the formation of drug and/or polymer particles for biomedical applications. In this study, nanoparticles of poly-(methyl vinyl ether-co-maleic anhydride (PVM/MA were successfully fabricated by a process of solution-enhanced dispersion by supercritical CO2 (SEDS. A 23 factorial experiment was designed to investigate and identify the significance of the processing parameters (concentration, flow and solvent/nonsolvent for the surface morphology, particle size, and particle size distribution of the products. The effect of the concentration of PVM/MA was found to be dominant in the results regarding particle size. Decreasing the initial solution concentration of PVM/MA decreased the particle size significantly. After optimization, the resulting PVM/MA nanoparticles exhibited a good spherical shape, a smooth surface, and a narrow particle size distribution. Fourier transform infrared spectroscopy (FTIR spectra demonstrated that the chemical composition of PVM/MA was not altered during the SEDS process and that the SEDS process was therefore a typical physical process. The absolute value of zeta potential of the obtained PVM/MA nanoparticles was larger than 40 mV, indicating the samples’ stability in aqueous suspension. Analysis of thermogravimetry-differential scanning calorimetry (TG-DSC revealed that the effect of the SEDS process on the thermostability of PVM/MA was negligible. The results of gas chromatography (GC analysis confirmed that the SEDS process could efficiently remove the organic residue.

  3. Near-infrared spectroscopic study of a water-in-supercritical CO2 microemulsion as a function of the water content.

    Science.gov (United States)

    Takebayashi, Yoshihiro; Sagisaka, Masanobu; Sue, Kiwamu; Yoda, Satoshi; Hakuta, Yukiya; Furuya, Takeshi

    2011-05-19

    A water-in-supercritical CO(2) microemulsion is a reverse micelle encapsulating a nanometer-size water droplet dispersed in supercritical CO(2). In the microemulsion solution, water exists not only in the reverse micelle but also in the solvent CO(2). For quantitative analysis of the water distribution, near-infrared spectra of water + CO(2) and water + surfactant + CO(2) mixtures were measured over a wide range of water/CO(2) ratios from 0.1 to 1.0 wt% at 60 °C and 30.0 MPa. The stretching combination band of water was decomposed into two components, a sharp one peaked at 7194 cm(-1) assigned to monomeric water dissolved in CO(2) and a broad one around 7000 cm(-1) corresponding to aggregated water in the microemulsion. Integrated molar absorptivities of these types of water were negligibly different from each other, despite the different hydrogen-bonding environments. The spectral decomposition revealed that water is distributed mainly into CO(2) at water contents smaller than 0.5 wt% and then is introduced into the microemulsion after saturation of water in CO(2) and full hydration of the surfactant headgroup.

  4. Supercritical CO2 extraction, chemical characterisation and antioxidant potential of Brassica oleracea var capitata against HO·, O2(·-) and ROO·.

    Science.gov (United States)

    Dal Prá, Valéria; Dolwitsch, Carolina Bolssoni; da Silveira, Géssica Domingos; Porte, Liliane; Frizzo, Clarissa; Tres, Marcus Vinicius; Mossi, Vinicius; Mazutti, Marcio Antonio; do Nascimento, Paulo Cícero; Bohrer, Denise; de Carvalho, Leandro Machado; Viana, Carine; da Rosa, Marcelo Barcellos

    2013-12-15

    In this work were extracted bioactive compounds from Brassica oleracea var capitata using supercritical CO2 and evaluated the antioxidant potential of the extracts. Five extractions were accomplished to investigate the influence of pressure (10-25 MPa) and temperature (20-60 °C) in the extraction yield, chemical composition and antioxidant potential towards peroxyl, superoxide and hydroxyl radicals. The highest extraction yield was obtained at 60 °C and 25 MPa, which was 0.47 wt% (run 2). In the characterisation of the extracts obtained was possible the identification of sulforaphane and iberin nitrile that present known biological properties. The extracts of all runs presented antioxidant activities towards the three radicals, but the highest activities for all radicals were using the extracts obtained in the run 2. The use of supercritical CO2 extraction to obtain bioactive compounds of B. oleracea var capitata showed to be a promising alternative to conventional extraction methods, since allowed the extraction of compounds with scientific and industrial interest. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Investigation of parameter estimation and impact of injection rate on relative permeability measurements for supercritical CO2 and water by unsteady-state method

    Science.gov (United States)

    Hiratsuka, Y.; Yamamoto, H.

    2014-12-01

    CCS (Carbon dioxide Capture and Storage) is a promising option for mitigating climate changes. To predict the behavior of injected CO2 in a deep reservoir, relative permeability of supercritical CO2 and water of the reservoir rock is one of the most fundamental and influential properties. For determining the relative permeability, we employed the unsteady state method, in which the relative permeability is determined based on history matching of transient monitoring data with a multi-phase flow model. The unsteady-state method is relatively simple and short, but obviously its accuracy strongly depends on the flow model assumed in the history matching. In this study, we conducted relative permeability measurements of supercritical CO2-water system for Berea sandstone with the unsteady-state method under a reservoir condition at a 1km depth (P= 9.5MPa, T = 44˚C). Automatic history matching was performed with an inversion simulator iTOUGH2/ECO2N for multi-phase flow system of supercritical CO2, NaCl, and water. A sensitivity analysis of relative permeability parameters for CO2 and water was carried out to better understand the uniqueness and the uncertainty of the optimum solution estimated by the history matching. Among the parameters of the Corey-type curve employed in this study, while the end-point permeability could be optimized in a limited range, the other parameters were correlated and their combinations were not unique. However it was found that any combination of these parameters results in nearly identical shapes of the curve in the range of CO2 saturation in this study (0 to 60%). The optimally estimated curve from the unsteady-method was well comparable with those from the steady-state method acquired in the previous studies. Our experiment also focuses on the impact of injection rate on the estimates of relative permeability, as it is known that the injection rate could have a significant effect on fluid distribution such as viscous fingering with

  6. Phase Equilibrium Calculation of Mixtures: Comparison of SAFT, Modified SAFT, and BACK EOS for Supercritical CO2-C2H5OH System

    Institute of Scientific and Technical Information of China (English)

    张志禹; 胡中桥; 杨基础; 李以圭

    2002-01-01

    Three calculational models, statistical associating fluid theory (SAFT), modified SAFT, and Boublík-Alder-Chen-Kreglewshi (BACK) are compared for supercritical CO2-C2H5OH using a set of van der Waals type mixing rules for both the BACK equation of state (EOS) and the SAFT EOS. Equations are presented for the residual Helmholtz free energy, residual chemical potentials, and compressibilty factor for mixtures. A comparison with experimental vapor-liquid equilibrium (VLE) data reveals that the BACK EOS together with the suggested mixing rules provides more accurate prediction of the binary system than the SAFT or the modified SAFT model with no adjustable binary parameters. The correlation results are improved with an adjustable parameter.

  7. One-pot synthesis of ZnS/polymer composites in supercritical CO2-ethanol solution and their applications in degradation of dyes.

    Science.gov (United States)

    Xie, Yun; Zhang, Chengliang; Miao, Shiding; Liu, Zhimin; Ding, Kunlun; Miao, Zhenjiang; An, Guimin; Yang, Zhenzhong

    2008-02-01

    A facile method to decorate the polymeric hollow spheres with ZnS nanoparticles has been presented. In this method, the precursors, Zn(Ac)(2)H(2)O and CH(3)CSNH(2), were first adsorbed by the polymer substrate in supercritical CO(2)-ethanol solution at 35 degrees C. Followed by heating the mixture at 100 degrees C for 2 h, ZnS/polymer composites were obtained. The as-produced ZnS/polymer composites were characterized by means of IR spectra, X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy. It was demonstrated that crystalline ZnS nanoparticles with size of 3-5 nm were uniformly decorated on the polymer spheres under suitable conditions. The resultant ZnS/polymer composites exhibited high efficiency for degrading eosin B, methyl orange and methylene blue under UV light irradiation.

  8. Preparation and Investigation Performance of Water- Based Epoxy Coating Containing Supercritical CO2 Synthesized SelfDoped Polyaniline-Expanded Graphite Nanohybrids As A Anti Corrosion Pigment

    Directory of Open Access Journals (Sweden)

    M.R.Baghezadeh

    2017-03-01

    Full Text Available In this research, self- doped polyaniline- expanded graphite nanohybrid (SPEG was synthesized by supercritical CO2 method and the anti-corrosion performance of SPEG in water- based epoxy coatings was considered. For this purpose, SPEG was introduced into water- based hardener and epoxy resin, separately via direct mixing under an ultrasonic homogenizer. The distribution of SPEG in both matrices was studied by zeta sizer, XRD and TEM characterization methods. The corrosion behavior of coatings was characterized salt spray and electrochemical impedance spectroscopy (EIS in 3.5 % NaCl solution. The results showed that coatings prepared by using SPEG in water-based hardener had the best corrosion resistance.

  9. [Comparison of Chemical Components of Essential Oil from Ocimum basilicum var. pilosum Extracted by Supercritical CO2 Fluid and Steam Distillation].

    Science.gov (United States)

    Wang, Zhao-yu; Zheng, Jia-huan; Shi, Sheng-ying; Luo, Zhi-xiong; Ni, Shun-yu; Lin, Jing-ming

    2015-11-01

    To compare the chemical components of essential oil prepared by steam distillation extraction (SD) and supercritical CO2 fluid extraction (SFE-CO2) from Ocimum basilicum var. pilosum whole plant. The essential oil of Ocimum basilicum var. pilosum were extracted by SD and SFE-CO2. The chemical components of essential oil were separated and analyzed by gas chromatography-mass spectrometry( GC-MS). Their relative contents were determined by normalization of peak area. 40 and 42 compounds were detected in the essential oil prepared by SD and SFE-CO2 respectively. 25 compounds were common. Thereare significant differences of the chemical components between the Ocimum basilicum var. pilosum essential oil prepared by SD and thatby SFE-CO2. Different methods showed different extraction efficiency with a special compound. It might be a good idea to unite several methods in the modern traditional Chinese medicine industry.

  10. Quantifying the flow dynamics of supercritical CO2-water displacement in a 2D porous micromodel using fluorescent microscopy and microscopic PIV

    Science.gov (United States)

    Kazemifar, Farzan; Blois, Gianluca; Kyritsis, Dimitrios C.; Christensen, Kenneth T.

    2016-09-01

    The multi-phase flow of liquid/supercritical CO2 and water (non-wetting and wetting phases, respectively) in a two-dimensional silicon micromodel was investigated at reservoir conditions (80 bar, 24 °C and 40 °C). The fluorescent microscopy and microscopic particle image velocimetry (micro-PIV) techniques were combined to quantify the flow dynamics associated with displacement of water by CO2 (drainage) in the porous matrix. To this end, water was seeded with fluorescent tracer particles, CO2 was tagged with a fluorescent dye and each phase was imaged independently using spectral separation in conjunction with microscopic imaging. This approach allowed simultaneous measurement of the spatially-resolved instantaneous velocity field in the water and quantification of the spatial configuration of the two fluid phases. The results, acquired with sufficient time resolution to follow the dynamic progression of both phases, provide a comprehensive picture of the flow physics during the migration of the CO2 front, the temporal evolution of individual menisci, and the growth of fingers within the porous microstructure. During that growth process, velocity jumps 20-25 times larger in magnitude than the bulk velocity were measured in the water phase and these bursts of water flow occurred both in-line with and against the bulk flow direction. These unsteady velocity events support the notion of pressure bursts and Haines jumps during pore drainage events as previously reported in the literature [1-3]. After passage of the CO2 front, shear-induced flow was detected in the trapped water ganglia in the form of circulation zones near the CO2-water interfaces as well as in the thin water films wetting the surfaces of the silicon micromodel. To our knowledge, the results presented herein represent the first quantitative spatially and temporally resolved velocity-field measurements at high pressure for water displacement by liquid/supercritical CO2 injection in a porous micromodel.

  11. Porous TiO(2)/SiO(2) composite prepared using PEG as template direction reagent with assistance of supercritical CO(2).

    Science.gov (United States)

    Jiao, Jianxia; Xu, Qun; Li, Limin

    2007-12-15

    Titania-silica mesoporous composites have been prepared using polyethylene glycol (PEG) 20,000 as a template direction reagent with the assistance of supercritical carbon dioxide (SC CO(2)). For this preparation method, the composite precursors of tetrabutyl titanate (TBTT) and tetraethyl orthosilicate (TEOS) were dissolved in supercritical CO(2) and impregnated into PEG 20,000 using SC CO(2) as swelling agent and carrier. After removal of the PEG template by calcination in air at suitable temperatures, porous titania-silica composites were obtained. Effects of CO(2) pressure and temperature have been studied on the impregnation ratio during the supercritical fluid condition. The composite products were characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), FTIR spectroscopy, nitrogen sorption-desorption experiments, scanning electronic microscope (SEM), and transmission electron microscope (TEM). XRD and nitrogen sorption-desorption experimental results indicate that the titania-silica composite crystallized in anatase phase and has a preferable BET surface area up to 301.98 m(2)/g. It was also demonstrated that the microstructure and macroproperty of TiO(2)/SiO(2) composites depend strongly on the experimental pressure during the impregnation process in SC CO(2). At suitable CO(2) pressure, silica even can be found in a single crystalline structure in nature by observation of TEM. At the same time, SEM indicates that the composite product existed in a spheric form or a cubic form inserted with many holes. So this work provides a new route to control and obtain the special micrography of TiO(2)/SiO(2) composites with the aid of suitable polymer templates in supercritical CO(2).

  12. Morphological effects of porous poly-d,l-lactic acid/hydroxyapatite scaffolds produced by supercritical CO2 foaming on their mechanical performance.

    Science.gov (United States)

    Rouholamin, Davood; van Grunsven, William; Reilly, Gwendolen C; Smith, Patrick J

    2016-08-01

    A novel supercritical CO2 foaming technique was used to fabricate scaffolds of controllable morphology and mechanical properties, with the potential to tailor the scaffolds to specific tissue engineering applications. Biodegradable scaffolds are widely used as temporary supportive structures for bone regeneration. The scaffolds must provide a sufficient mechanical support while allowing cell attachment and growth as well as metabolic activities. In this study, supercritical CO2 foaming was used to prepare fully interconnected porous scaffolds of poly-d,l-lactic acid and poly-d,l-lactic acid/hydroxyapatite. The morphological, mechanical and cell behaviours of the scaffolds were measured to examine the effect of hydroxyapatite on these properties. These scaffolds showed an average porosity in the range of 86%-95%, an average pore diameter of 229-347 µm and an average pore interconnection of 103-207 µm. The measured porosity, pore diameter, and interconnection size are suitable for cancellous bone regeneration. Compressive strength and modulus of up to 36.03 ± 5.90 and 37.97 ± 6.84 MPa were measured for the produced porous scaffolds of various compositions. The mechanical properties presented an improvement with the addition of hydroxyapatite to the structure. The relationship between morphological and mechanical properties was investigated. The matrices with different compositions were seeded with bone cells, and all the matrices showed a high cell viability and biocompatibility. The number of cells attached on the matrices slightly increased with the addition of hydroxyapatite indicating that hydroxyapatite improves the biocompatibility and proliferation of the scaffolds. The produced poly-d,l-lactic acid/hydroxyapatite scaffolds in this study showed a potential to be used as bone graft substitutes.

  13. A numerical study of the supercritical CO2 plate heat exchanger subject to U-type, Z-type, and multi-pass arrangements

    Science.gov (United States)

    Zhu, Chen-Xi; Wang, Chi-Chuan

    2017-07-01

    This study proposes a numerical model for plate heat exchanger that is capable of handling supercritical CO2 fluid. The plate heat exchangers under investigation include Z-type (1-pass), U-type (1-pass), and 1-2 pass configurations. The plate spacing is 2.9 mm with a plate thickness of 0.8 mm, and the size of the plate is 600 mm wide and 218 mm in height with 60 degrees chevron angle. The proposed model takes into account the influence of gigantic change of CO2 properties. The simulation is first compared with some existing data for water-to-water plate heat exchangers with good agreements. The flow distribution, pressure drop, and heat transfer performance subject to the supercritical CO2 in plate heat exchangers are then investigated. It is found that the flow velocity increases consecutively from the entrance plate toward the last plate for the Z-type arrangement, and this is applicable for either water side or CO2 side. However, the flow distribution of the U-type arrangement in the water side shows opposite trend. Conversely, the flow distribution for U-type arrangement of CO2 depends on the specific flow ratio (C*). A lower C* like 0.1 may reverse the distribution, i.e. the flow velocity increases moderately alongside the plate channel like Z-type while a large C* of 1 would resemble the typical distribution in water channel. The flow distribution of CO2 side at the first and last plate shows a pronounced drop/surge phenomenon while the channels in water side does not reveal this kind of behavior. The performance of 2-pass plate heat exchanger, in terms of heat transfer rate, is better than that of 1-pass design only when C* is comparatively small (C* < 0.5). Multi-pass design is more effective when the dominant thermal resistance falls in the CO2 side.

  14. High Materials Performance in Supercritical CO2 in Comparison with Atmospheric Pressure CO2 and Supercritical Steam

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, Gordon [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Tylczak, Joseph [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Carney, Casey [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Dogan, Omer N. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)

    2017-02-26

    This presentation covers environments (including advanced ultra-supercritical (A-USC) steam boiler/turbine and sCO2 indirect power cycle), effects of pressure, exposure tests, oxidation results, and mechanical behavior after exposure.

  15. Desorptionof Carbon Dioxidein Supercritical CO2-Swollen Polymers%二氧化碳从它溶胀后的聚合物中的解吸

    Institute of Scientific and Technical Information of China (English)

    叶树集; 陈鸣才; 姜明; 伏义路

    2000-01-01

    A study was undertaken to investigate the desorption of CO2 in the six polymers,namely,LDPE,PP,PA6,EVA,PS and PU.The six polymers were treated in supercritical CO2.The temperature of supercritical CO2 was 40℃,pressure was from 8.0 to 14.0MPa.The weight change of polymers after treatment was fitted with two functions.One function was Y=Y0+Aexp{-(t-t0)/τ},the other was Y=Y0+A(t-t0)1/2.The result indicated that the weight change of polymers after treatment in mass with time showed a dependence on the logarithm of time.The desorption equation of CO2 in polymers was given in accordance with Fickian diffusion law.The diffusion coefficient of CO2 was calculated with the desorption equation.The result suggested that the diffusion coefficient of CO2 was about 10-7cm2/s and it depended on the amount of CO2 in polymer,temperature and the treated pressure.%研究了经过40℃,8.0~14.0MPa的超临界二氧化碳溶胀后的6种聚合物LDPE、PP、PA6、EVA、PS和PU中的CO2解吸情况,模拟了聚合物中CO2的解吸规律,即以时间的自然指数递减规律,并根据Fick扩散定理从理论上推导出CO2在聚合物中的解吸方程,由解吸方程计算解吸扩散系数,结果表明CO2的解吸扩散系数数量级达10-7cm2/s,解吸扩散系数与CO2在聚合物中的浓度和温度以及解吸前聚合物在超临界二氧化碳中的压力有关。

  16. Study on Extraction Technology of Tea Seed Oil by Supercritical CO2%超临界CO2萃取茶叶籽油

    Institute of Scientific and Technical Information of China (English)

    陈升荣; 张彬; 罗家星; 邓丹雯

    2012-01-01

    In this paper, microwave is used to bake tea seed kernel, and the optimal parameter of tea seed oil extraction process by supercritical CO2 is studied. Experimental results show that the optimal conditions are: extrac- tion temperature 60℃ , extraction pressure 30MPa, extraction time 100 min, CO2 flow rate 45 - 55 kg/h, and the ex- traction rate is 94.1%. The physical and chemical properties and the fatty acid composition of the tea seed oil are de- termined.%采用微波加热茶叶籽仁粉,用超临界CO2萃取茶叶籽油,探讨了超临界CO2萃取茶叶籽油适宜工艺参数。实验结果表明:在萃取温度60℃、萃取压力30MPa,萃取时间100min,CO2流量45~55kg/h条件下,油脂提取率为94.1%,并测定了茶叶籽油的理化性质及脂肪酸组成。

  17. Probing Lewis Acid-Base Interactions with Born-Oppenheimer Molecular Dynamics: The Electronic Absorption Spectrum of p-Nitroaniline in Supercritical CO2.

    Science.gov (United States)

    Cabral, Benedito J Costa; Rivelino, Roberto; Coutinho, Kaline; Canuto, Sylvio

    2015-07-02

    The structure and dynamics of p-nitroaniline (PNA) in supercritical CO2 (scCO2) at T = 315 K and ρ = 0.81 g cm(-3) are investigated by carrying out Born-Oppenheimer molecular dynamics, and the electronic absorption spectrum in scCO2 is determined by time dependent density functional theory. The structure of the PNA-scCO2 solution illustrates the role played by Lewis acid-base (LA-LB) interactions. In comparison with isolated PNA, the ν(N-O) symmetric and asymmetric stretching modes of PNA in scCO2 are red-shifted by -17 and -29 cm(-1), respectively. The maximum of the charge transfer (CT) absorption band of PNA in scSCO2 is at 3.9 eV, and the predicted red-shift of the π → π* electronic transition relative to the isolated gas-phase PNA molecule reproduces the experimental value of -0.35 eV. An analysis of the relationship between geometry distortions and excitation energies of PNA in scCO2 shows that the π → π* CT transition is very sensitive to changes of the N-O bond distance, strongly indicating a correlation between vibrational and electronic solvatochromism driven by LA-LB interactions. Despite the importance of LA-LB interactions to explain the solvation of PNA in scCO2, the red-shift of the CT band is mainly determined by electrostatic interactions.

  18. Dyeing PET Textile with C.I. Disperse Red 60 and C.I. Disperse Orange 25 in Supercritical CO2

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-yi; MENG Ting-yu; LIU Xue-wu; XIA Yuan-jing; HU Da-peng

    2008-01-01

    For a better understanding of the feasibility of supercritical fluid dyeing(SFD)and more available information for the process development,the experiments of dyeing PET textile with C.I.disperse red 60(anthraquinone type)and C.I.disperse orange 25(azo type)in supercritical CO2 were carried out with a high-pressure dyeing apparatus at temperatures from 80 to 130℃ and pressure up to 31 MPa.The effect of operating conditions on color yield(K/S)was investigated in SFD experiment,and the optimum operating conditions for the above two disperse dyes were obtained as follows:the temperature 120℃,the pressure 25 MPa and the dyeing time 100 min.As compared with SFD,the conventional water dyeing(CWD)was carded out with the same dyes and textile.The results show that the better fastness,IeveIness and apparent color can be achieved in SFD and the SFD process has many significant advantages over the CWD process.

  19. Antiageing Mechanisms of a Standardized Supercritical CO2 Preparation of Black Jack (Bidens pilosa L. in Human Fibroblasts and Skin Fragments

    Directory of Open Access Journals (Sweden)

    Gustavo Dieamant

    2015-01-01

    Full Text Available The use of topical retinoids to treat skin disorders and ageing can induce local reactions, while oral retinoids are potent teratogens and produce several unwanted effects. This way, efforts to explore complementary care resources should be supported. Based on this, we evaluate the antiageing effects of a supercritical CO2 extract from Bidens pilosa L. (BPE-CO2A containing a standardized multicomponent mixture of phytol, linolenic, palmitic, linoleic, and oleic acids. BPE-CO2A was assessed for its effects on human dermal fibroblasts (TGF-β1 and FGF levels using ELISA; collagen, elastin, and glycosaminoglycan by colorimetric assays, and mRNA expression of RXR, RAR, and EGFr by qRT-PCR and human skin fragments (RAR, RXR, collagen, elastin, and glycosaminoglycan by immunohistochemical analysis. Levels of extracellular matrix elements, TGF-β1 and FGF, and EGFr gene expression were significantly increased by BPE-CO2A. The modulation of RXR and RAR was positively demonstrated after the treatment with BPE-CO2A or phytol, a component of BPE-CO2A. The effects produced by BPE-CO2A were similar to or better than those produced by retinol and retinoic acid. The ability to stimulate extracellular matrix elements, increase growth factors, and modulate retinoid and rexinoid receptors provides a basis for the development of preparation containing BPE-CO2A as an antiageing/skin-repair agent.

  20. Safety and Efficacy of Rice Bran Supercritical CO2 Extract for Hair Growth in Androgenic Alopecia: A 16-Week Double-Blind Randomized Controlled Trial.

    Science.gov (United States)

    Choi, Jae-Suk; Park, Jae Beom; Moon, Woi-Sook; Moon, Jin-Nam; Son, Sang Wook; Kim, Mi-Ryung

    2015-01-01

    We conducted a 16-week double-blind randomized controlled single-center trial to evaluate the safety and efficacy of dermal rice bran supercritical CO2 extract (RB-SCE) in the treatment of androgenic alopecia. Fifty alopecia patients were randomly assigned to the experimental and placebo groups. The experimental group received a dermal application of 0.5% RB-SCE (8 mL/d) to the head skin for 16 weeks while the control group received a dermal application of placebo. Changes in hair count, diameter, and density were evaluated with a Folliscope(®). Patient satisfaction was evaluated via questionnaire and clinical photographs were rated by dermatologists. The results showed that RB-SCE significantly increased hair density and hair diameter in male subjects. Patient satisfaction and the evaluation of photographs by dermatologists also confirmed the effectiveness of RB-SCE in the treatment of alopecia. No adverse reactions related to RB-SCE were reported. Therefore, RB-SCE shows promise for use in functional cosmetics and pharmaceuticals.

  1. Chemical composition of Lycium europaeum fruit oil obtained by supercritical CO2 extraction and evaluation of its antioxidant activity, cytotoxicity and cell absorption.

    Science.gov (United States)

    Rosa, Antonella; Maxia, Andrea; Putzu, Danilo; Atzeri, Angela; Era, Benedetta; Fais, Antonella; Sanna, Cinzia; Piras, Alessandra

    2017-09-01

    We studied the total phenols and flavonoids, liposoluble antioxidants, fatty acid and triacylglycerol profiles, and oxidative status of oil obtained from Lycium europaeum fruits following supercritical CO2 extraction (at 30MPa and 40°C). Linoleic (52%), palmitic (18%), oleic (13%), and α-linolenic (6%) were the main oil fatty acids, while trilinolein and palmitodilinolein/oleodilinolein represented the main triacylglycerols. The oil was characterized by high levels of all-trans-zeaxanthin and all-trans-β-carotene (755 and 332μg/g of oil, respectively), α-tocopherol (308μg/g of oil), total phenols (13.6mg gallic acid equivalents/g of oil), and total flavonoids (6.8mg quercetin equivalents/g of oil). The oil showed radical scavenging activities (ABTS and DPPH assays) and inhibited Caco-2 cell growth. Moreover, the incubation of differentiated Caco-2 cells with a non-toxic oil concentration (100μg/mL) induced a significant intracellular accumulation of essential fatty acids. The results qualify L. europaeum oil as a potential source for food/pharmaceutical applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Optimization of process parameters of extraction of amentoflavone, quercetin and ginkgetin from Taxus chinensis using supercritical CO2 plus co-solvent.

    Science.gov (United States)

    Ruan, Xiao; Yan, Liu-Ye; Li, Xian-Xian; Liu, Ben; Zhang, Huan; Wang, Qiang

    2014-10-31

    The effects of extraction time, temperature, pressure and different concentration of ethanol and their interactions on the yields of amentoflavone, quercetin and ginkgetin extracted from Taxus chinensis by supercritical CO2 were investigated by using a central composite design (CCD). An CCD experimental design with four factors and five levels was used to optimize the extraction parameters. Ultra performance liquid chromatography (UPLC) was used to analyze the content of the tree components in the extracts. Experimental results show that the main effects of factors and their interactions are significant on the yields (p extraction conditions were established for the three compounds: yield of 4.47 mg/g for amentoflavone at 48 °C, 25 MPa, 2.02 h and 78.5% ethanol, 3.73 mg/g for quercetin at 46 °C, 24 MPa, 2.3 h, 82% ethanol and 3.47 mg/g for ginkgetin at 48 °C, 20 MPa, 2.38 h, 82% ethanol, respectively.

  3. In Situ Natural Abundance (17)O and (25)Mg NMR Investigation of Aqueous Mg(OH)2 Dissolution in the Presence of Supercritical CO2.

    Science.gov (United States)

    Hu, Mary Y; Deng, Xuchu; Thanthiriwatte, K Sahan; Jackson, Virgil E; Wan, Chuan; Qafoku, Odeta; Dixon, David A; Felmy, Andrew R; Rosso, Kevin M; Hu, Jian Zhi

    2016-11-15

    We report an in situ high-pressure NMR capability that permits natural abundance (17)O and (25)Mg NMR characterization of dissolved species in aqueous solution and in the presence of supercritical CO2 fluid (scCO2). The dissolution of Mg(OH)2 (brucite) in a multiphase water/scCO2 fluid at 90 atm pressure and 50 °C was studied in situ, with relevance to geological carbon sequestration. (17)O NMR spectra allowed identification and distinction of various fluid species including dissolved CO2 in the H2O-rich phase, scCO2, aqueous H2O, and HCO3(-). The widely separated spectral peaks for various species can all be observed both dynamically and quantitatively at concentrations as low as 20 mM. Measurement of the concentrations of these individual species also allows an in situ estimate of the hydrogen ion concentration, or pCH(+) values, of the reacting solutions. The concentration of Mg(2+) can be observed by natural abundance (25)Mg NMR at a concentration as low as 10 mM. Quantum chemistry calculations of the NMR chemical shifts on cluster models aided in the interpretation of the experimental results. Evidence for the formation of polymeric Mg(2+) clusters at high concentrations in the H2O-rich phase, a possible critical step needed for magnesium carbonate formation, was found.

  4. Silicate Carbonation in Supercritical CO2 Containing Dissolved H2O: An in situ High Pressure X-Ray Diffraction Study

    Energy Technology Data Exchange (ETDEWEB)

    Schaef, Herbert T.; Miller, Quin RS; Thompson, Christopher J.; Loring, John S.; Bowden, Mark E.; Arey, Bruce W.; McGrail, B. Peter; Rosso, Kevin M.

    2013-06-30

    Technological advances have been significant in recent years for managing environmentally harmful emissions (mostly CO2) resulting from combustion of fossil fuels. Deep underground geologic formations are emerging as reasonable options for long term storage of CO2 but mechanisms controlling rock and mineral stability in contact with injected supercritical fluids containing water are relatively unknown. In this paper, we discuss mineral transformation reactions occurring between supercritical CO2 containing water and the silicate minerals forsterite (Mg2SiO4), wollastonite (CaSiO3), and enstatite (MgSiO3). This study utilizes newly developed in situ high pressure x-ray diffraction (HXRD) and in situ infra red (IR) to examine mineral transformation reactions. Forsterite and enstatite were selected as they are important minerals present in igneous and mafic rocks and have been the subject of a large number of aqueous dissolution studies that can be compared with non-aqueous fluid tests in this study. Wollastonite, classified as a pyroxenoid (similar to a pyroxene), was chosen as a suitably fast reacting proxy for examining silicate carbonation processes associated with a wet scCO2 fluid as related to geologic carbon sequestration. The experiments were conducted under modest pressures (90 to 160 bar), temperatures between 35° to 70° C, and varying concentrations of dissolved water. Under these conditions scCO2 contains up to 3,500 ppm dissolved water.

  5. Optimization and Comparison of Direct and Indirect Supercritical Carbon Dioxide Power Plant Cycles for Nuclear Applications

    Energy Technology Data Exchange (ETDEWEB)

    Edwin A. Harvego; Michael G. McKellar

    2011-11-01

    There have been a number of studies involving the use of gases operating in the supercritical mode for power production and process heat applications. Supercritical carbon dioxide (CO2) is particularly attractive because it is capable of achieving relatively high power conversion cycle efficiencies in the temperature range between 550 C and 750 C. Therefore, it has the potential for use with any type of high-temperature nuclear reactor concept, assuming reactor core outlet temperatures of at least 550 C. The particular power cycle investigated in this paper is a supercritical CO2 Recompression Brayton Cycle. The CO2 Recompression Brayton Cycle can be used as either a direct or indirect power conversion cycle, depending on the reactor type and reactor outlet temperature. The advantage of this cycle when compared to the helium Brayton cycle is the lower required operating temperature; 550 C versus 850 C. However, the supercritical CO2 Recompression Brayton Cycle requires an operating pressure in the range of 20 MPa, which is considerably higher than the required helium Brayton cycle operating pressure of 8 MPa. This paper presents results of analyses performed using the UniSim process analyses software to evaluate the performance of both a direct and indirect supercritical CO2 Brayton Recompression cycle for different reactor outlet temperatures. The direct supercritical CO2 cycle transferred heat directly from a 600 MWt reactor to the supercritical CO2 working fluid supplied to the turbine generator at approximately 20 MPa. The indirect supercritical CO2 cycle assumed a helium-cooled Very High Temperature Reactor (VHTR), operating at a primary system pressure of approximately 7.0 MPa, delivered heat through an intermediate heat exchanger to the secondary indirect supercritical CO2 Brayton Recompression cycle, again operating at a pressure of about 20 MPa. For both the direct and indirect cycles, sensitivity calculations were performed for reactor outlet temperature

  6. VIABILITY AND ACTIVITY OF MICROORGANISMS IN SUPERCRITICAL CO2%超临界二氧化碳中微生物的存活率与催化活性

    Institute of Scientific and Technical Information of China (English)

    张宝泉; 刘秀凤; 甘一如; 贾士儒

    2003-01-01

    @@ INTRODUCTION In-situ removal of inhibitory products by supercritical fluid extraction(SCFE)has drawn much attention recently[1,2].Supercritical CO2(SCCO2) possesses many advantages over organic solvents due to its special characteristics and environmental benefits [1,3-5].It has been widely used in food processing and preservation, alcohol production, and enzyme-catalyzed reactions [1-6].

  7. The interplay between the paracetamol polymorphism and its molecular structures dissolved in supercritical CO2 in contact with the solid phase: In situ vibration spectroscopy and molecular dynamics simulation analysis.

    Science.gov (United States)

    Oparin, Roman D; Moreau, Myriam; De Walle, Isabelle; Paolantoni, Marco; Idrissi, Abdenacer; Kiselev, Michael G

    2015-09-18

    The aim of this paper is to characterize the distribution of paracetamol conformers which are dissolved in a supercritical CO2 phase being in equilibrium with their corresponding crystalline form. The quantum calculations and molecular dynamics simulations were used in order to characterize the structure and analyze the vibration spectra of the paracetamol conformers in vacuum and in a mixture with CO2 at various thermodynamic state parameters (p,T). The metadynamics approach was applied to efficiently sample the various conformers of paracetamol. Furthermore, using in situ IR spectroscopy, the conformers that are dissolved in supercritical CO2 were identified and the evolution of the probability of their presence as a functions of thermodynamic condition was quantified while the change in the crystalline form of paracetamol have been monitored by DSC, micro IR and Raman techniques. The DSC analysis as well as micro IR and Raman spectroscopic studies of the crystalline paracetamol show that the subsequent heating up above the melting temperature of the polymorph I of paracetamol and the cooling down to room temperature in the presence of supercritical CO2 induces the formation of polymorph II. The in situ IR investigation shows that two conformers (Conf. 1 and Conf. 2) are present in the phase of CO2 while conformer 3 (Conf. 3) has a high probability to be present after re-crystallization. Copyright © 2015. Published by Elsevier B.V.

  8. Extraction of Flavonoids from the Flowers of Abelmoschus manihot (L. Medic by Modified Supercritical CO2 Extraction and Determination of Antioxidant and Anti-Adipogenic Activity

    Directory of Open Access Journals (Sweden)

    Jingjing Li

    2016-06-01

    Full Text Available Abelmoschus manihot (L. Medic has been used for many years in Chinese traditional medicine. In this study, supercritical CO2 plus a modifier was utilized to extract flavonoids from the flowers of Abelmoschus manihot (L. Medic. The effects of temperature (40 °C–60 °C, pressure (10–30 MPa and different concentrations of ethanol as modifier (60%–90%, ethanol:water, v/v on major flavonol content and the antioxidant activity of the extracts were studied by response surface methodology (RSM using a Box-Behnken design. The flavonol content was calculated as the sum of the concentrations of seven major flavonoids, namely rutin, hyperin, isoquercetin, hibifolin, myricetin, quercetin-3′-O-glucoside and quercetin, which were simultaneously determined by a HPLC method. The antioxidant activity was evaluated by a 2,2-diphenyl-1-picrylhydarzyl (DPPH free radical-scavenging assay. The results showed that three factors and their interactions could be well fitted to second-order polynomial models (p < 0.05. At the optimal extraction conditions for flavonol content (20 MPa, 52 °C, and 85% ethanol content, the yield of flavonoids was 41.96 mg/g and the IC50 value was 0.288 mg/mL, respectively, suggesting the extract has high antioxidant activity. Furthermore, the anti-adipogenic activity of the extract on the 3T3-L1 cell line was investigated. The results indicated that it can downregulate PPARγ and C/EBPα expression at mRNA. In summary, in this study, we have established a cost-effective method for the extraction of flavonoids from the flowers of Abelmoschus manihot (L. Medic using supercritical fluid extraction and the extracts exhibited potent antioxidant and anti-adipogenic effects, suggesting a possible therapeutic approach for the prevention and treatment of obesity.

  9. Extraction of passion fruit seed oil using supercritical CO2: a study of mass transfer and rheological property by Bayesian inference

    Directory of Open Access Journals (Sweden)

    Cardoso de Oliveira, R.

    2013-09-01

    Full Text Available The extraction of oil from passion fruit seeds using supercritical CO2 was studied. Experimental data were obtained for extraction conducted at 15, 20 and 25 MPa; at temperatures of 40 and 50 °C with CO2 flow rates of 1.5 and 3.0 mL min–1. An increase in the pressure, temperature and CO2 flow rate increased the yield. The maximum extraction yield obtained was 18.5%. The mass transfer coefficients for passion fruit oil were found to be 8.496 3 10-5 s-1 at 25 MPa, 50 °C and 3 mL s–1 CO2 flow rate. Dilatant fluid behavior was observed in all tests of the rheological study.Se ha estudiado la extracción de aceite de semillas de frutos de la pasión con CO2 supercrítico. Los datos experimentales se obtuvieron para una extracción llevada a cabo a 15, 20 y 25 MPa; a temperaturas de 40 y 50 °C y a flujos de CO2 de 1,5 y 3,0 mL min–1. Un incremento de la presión, la temperatura y del flujo de CO2 aumentó el rendimiento. El máximo rendimiento de la extracción obtenida fue de 18,5%. Los coeficientes de transferencia de masa para el aceite de fruta de la pasión encontrados fueron 8,496 3 10-5 s–1 a 25 MPa, 50 °C y 3 mL s–1 de flujo de CO2. Se observó un comportamiento de fluido dilatante en todos los ensayos reológicos.

  10. In situ investigation of supercritical CO2 assisted impregnation of drugs into a polymer by high pressure FTIR micro-spectroscopy.

    Science.gov (United States)

    Champeau, M; Thomassin, J-M; Jérôme, C; Tassaing, T

    2015-02-01

    An original experimental set-up combining a FTIR micro-spectrometer with a high pressure cell has been built in order to analyze in situ the impregnation of a solute into microscopic polymer samples, such as fibers or films, subjected to supercritical CO2. Thanks to this experimental set-up, key factors governing the impregnation process can be simultaneously followed such as the swelling of the polymeric matrix, the CO2 sorption, the kinetics of impregnation and the drug loading into the matrix. Moreover, the solute/polymer interactions and the speciation of the solute can be analyzed. We have monitored in situ the impregnation of aspirin and ketoprofen into PEO (Polyethylene Oxide) platelets at T = 40 °C and P = 5; 10 and 15 MPa. The kinetics of impregnation of aspirin was quicker than the one of ketoprofen and the final drug loading was also higher in the case of aspirin. Whereas the CO2 sorption and the PEO swelling remain constant when PEO is just subjected to CO2 under isobaric conditions, we noticed that both parameters can increase while the drug impregnates PEO. Coupling these results with DSC measurements, we underlined the plasticizing effect of the drug that also leads to a decrease in the crystallinity of PEO in situ thus favoring the sorption of CO2 molecules into the matrix and the swelling of the matrix. The plasticizing effect increases with the drug loading. Finally, the speciation of drugs was investigated considering the shift of the carboxyl bands of the drugs. Both drugs were found to be mainly homogeneously dispersed into PEO.

  11. In situ mid-infrared spectroscopic titration of forsterite with water in supercritical CO2: Dependence of mineral carbonation on quantitative water speciation

    Science.gov (United States)

    Loring, J. S.; Thompson, C. J.; Wang, Z.; Schaef, H. T.; Martin, P.; Qafoku, O.; Felmy, A. R.; Rosso, K. M.

    2011-12-01

    Geologic sequestration of carbon dioxide holds promise for helping mitigate CO2 emissions generated from the burning of fossil fuels. Supercritical CO2 (scCO2) plumes containing variable water concentrations (wet scCO2) will displace aqueous solution and dominate the pore space adjacent to caprocks. It is important to understand possible mineral reactions with wet scCO2 to better predict long-term caprock integrity. We introduce novel in situ instrumentation that enables quantitative titrations of reactant minerals with water in scCO2 at temperatures and pressures relevant to target geologic reservoirs. The system includes both transmission and attenuated total reflection mid-infrared optics. Transmission infrared spectroscopy is used to measure concentrations of water dissolved in the scCO2, adsorbed on mineral surfaces, and incorporated into precipitated carbonates. Single-reflection attenuated total reflection infrared spectroscopy is used to monitor water adsorption, mineral dissolution, and carbonate precipitation reactions. Results are presented for the infrared spectroscopic titration of forsterite (Mg2SiO4), a model divalent metal silicate, with water in scCO2 at 100 bar and at both 50 and 75°C. The spectral data demonstrate that the quantitative speciation of water as either dissolved or adsorbed is important for understanding the types, growth rates, and amounts of carbonate precipitates formed. Relationships between dissolved/adsorbed water, water concentrations, and the role of liquid-like adsorbed water are discussed. Our results unify previous in situ studies from our laboratory based on infrared spectroscopy, nuclear magnetic resonance spectroscopy and X-ray diffraction.

  12. Energy Conversion Alternatives Study (ECAS), General Electric Phase 1. Volume 2: Advanced energy conversion systems. Part 1: Open-cycle gas turbines

    Science.gov (United States)

    Brown, D. H.; Corman, J. C.

    1976-01-01

    Ten energy conversion systems are defined and analyzed in terms of efficiency. These include: open-cycle gas turbine recuperative; open-cycle gas turbine; closed-cycle gas turbine; supercritical CO2 cycle; advanced steam cycle; liquid metal topping cycle; open-cycle MHD; closed-cycle inert gas MHD; closed-cycle liquid metal MHD; and fuel cells. Results are presented.

  13. Optimization of Operation Parameters for Helical Flow Cleanout with Supercritical CO2 in Horizontal Wells Using Back-Propagation Artificial Neural Network

    Science.gov (United States)

    Song, Xianzhi; Peng, Chi; Li, Gensheng

    2016-01-01

    Sand production and blockage are common during the drilling and production of horizontal oil and gas wells as a result of formation breakdown. The use of high-pressure rotating jets and annular helical flow is an effective way to enhance horizontal wellbore cleanout. In this paper, we propose the idea of using supercritical CO2 (SC-CO2) as washing fluid in water-sensitive formation. SC-CO2 is manifested to be effective in preventing formation damage and enhancing production rate as drilling fluid, which justifies tis potential in wellbore cleanout. In order to investigate the effectiveness of SC-CO2 helical flow cleanout, we perform the numerical study on the annular flow field, which significantly affects sand cleanout efficiency, of SC-CO2 jets in horizontal wellbore. Based on the field data, the geometry model and mathematical models were built. Then a numerical simulation of the annular helical flow field by SC-CO2 jets was accomplished. The influences of several key parameters were investigated, and SC-CO2 jets were compared to conventional water jets. The results show that flow rate, ambient temperature, jet temperature, and nozzle assemblies play the most important roles on wellbore flow field. Once the difference between ambient temperatures and jet temperatures is kept constant, the wellbore velocity distributions will not change. With increasing lateral nozzle size or decreasing rear/forward nozzle size, suspending ability of SC-CO2 flow improves obviously. A back-propagation artificial neural network (BP-ANN) was successfully employed to match the operation parameters and SC-CO2 flow velocities. A comprehensive model was achieved to optimize the operation parameters according to two strategies: cost-saving strategy and local optimal strategy. This paper can help to understand the distinct characteristics of SC-CO2 flow. And it is the first time that the BP-ANN is introduced to analyze the flow field during wellbore cleanout in horizontal wells. PMID

  14. Comparison of quantitative PCR and flow cytometry as cellular viability methods to study bacterial membrane permeabilization following supercritical CO2 treatment.

    Science.gov (United States)

    Tamburini, Sabrina; Ballarini, Annalisa; Ferrentino, Giovanna; Moro, Albertomaria; Foladori, Paola; Spilimbergo, Sara; Jousson, Olivier

    2013-06-01

    Foodborne illness due to bacterial pathogens is increasing worldwide as a consequence of the higher consumption of fresh and minimally processed food products, which are more easily cross-contaminated. The efficiency of food pasteurization methods is usually measured by c.f.u. plate counts, a method discriminating viable from dead cells on the basis of the ability of cells to replicate and form colonies on standard growth media, thus ignoring viable but not cultivable cells. Supercritical CO2 (SC-CO2) has recently emerged as one of the most promising fresh food pasteurization techniques, as an alternative to traditional, heat-based methods. In the present work, using three SC-CO2-treated foodborne bacteria (Listeria monocytogenes, Salmonella enterica and Escherichia coli) we tested and compared the performance of alternative viability test methods based on membrane permeability: propidium monoazide quantitative PCR (PMA-qPCR) and flow cytometry (FCM). Results were compared based on plate counts and fluorescent microscopy measurements, which showed that the former dramatically reduced the number of cultivable cells by more than 5 log units. Conversely, FCM provided a much more detailed picture of the process, as it directly quantifies the number of total cells and distinguishes among three categories, including intact, partially permeabilized and permeabilized cells. A comparison of both PMA-qPCR and FCM with plate count data indicated that only a fraction of intact cells maintained the ability to replicate in vitro. Following SC-CO2 treatment, FCM analysis revealed a markedly higher level of bacterial membrane permeabilization of L. monocytogenes with respect to E. coli and S. enterica. Furthermore, an intermediate permeabilization state in which the cellular surface was altered and biovolume increased up to 1.5-fold was observed in L. monocytogenes, but not in E. coli or S. enterica. FCM thus compared favourably with other methods and should be considered as an

  15. Optimization of Operation Parameters for Helical Flow Cleanout with Supercritical CO2 in Horizontal Wells Using Back-Propagation Artificial Neural Network.

    Directory of Open Access Journals (Sweden)

    Xianzhi Song

    Full Text Available Sand production and blockage are common during the drilling and production of horizontal oil and gas wells as a result of formation breakdown. The use of high-pressure rotating jets and annular helical flow is an effective way to enhance horizontal wellbore cleanout. In this paper, we propose the idea of using supercritical CO2 (SC-CO2 as washing fluid in water-sensitive formation. SC-CO2 is manifested to be effective in preventing formation damage and enhancing production rate as drilling fluid, which justifies tis potential in wellbore cleanout. In order to investigate the effectiveness of SC-CO2 helical flow cleanout, we perform the numerical study on the annular flow field, which significantly affects sand cleanout efficiency, of SC-CO2 jets in horizontal wellbore. Based on the field data, the geometry model and mathematical models were built. Then a numerical simulation of the annular helical flow field by SC-CO2 jets was accomplished. The influences of several key parameters were investigated, and SC-CO2 jets were compared to conventional water jets. The results show that flow rate, ambient temperature, jet temperature, and nozzle assemblies play the most important roles on wellbore flow field. Once the difference between ambient temperatures and jet temperatures is kept constant, the wellbore velocity distributions will not change. With increasing lateral nozzle size or decreasing rear/forward nozzle size, suspending ability of SC-CO2 flow improves obviously. A back-propagation artificial neural network (BP-ANN was successfully employed to match the operation parameters and SC-CO2 flow velocities. A comprehensive model was achieved to optimize the operation parameters according to two strategies: cost-saving strategy and local optimal strategy. This paper can help to understand the distinct characteristics of SC-CO2 flow. And it is the first time that the BP-ANN is introduced to analyze the flow field during wellbore cleanout in

  16. Laboratory Seismic Monitoring and X-ray CT imaging of Supercritical CO2 Injection in Reservoir Sand: WESTCAB King Island Project

    Science.gov (United States)

    Nakashima, S.; Kneafsey, T. J.; Nakagawa, S.; Harper, E. J.

    2013-12-01

    The Central Valley of California contains promising locations for on-shore geologic CO2 storage. DOE's WESTCARB (West Coast Regional Carbon Sequestration Partnership) project drilled and cored a borehole (Citizen Green Well) at King Island (near Stockton, CA) to study the CO2 storage capability of saline and gas-bearing formations in the southwestern Sacramento Basin. Potential reservoirs encountered in the borehole include Domengine, Mokelumne River (primary target), and Top Starkey formations. In anticipation of geophysical monitoring of possible CO2 injection into this particular borehole and of the long-term migration of the CO2, we conducted small-scale CO2 injection experiments on three core samples retrieved from the well (Mokelumne River sand A and B) and from a mine outcrop (Domengine sandstone). During the experiment, a jacketed core sample (diameter 1.5 inches, length 4.0-6.0 inches) saturated with brine- (1% NaCl aq.) was confined within a pressure vessel via compressed nitrogen to 3,500-4,000psi, and supercritical CO2 was injected into the core at 2,000-2,500psi and 45-60 degrees C. The CO2 pressure and temperature were adjusted so that the bulk elastic modulus of the CO2 was close to the expected in-situ modulus--which affects the seismic properties most--while keeping the confining stress within our experimental capabilities. After the CO2 broke through the core, fresh brine was re-injected to remove the CO2 by both displacement and dissolution. Throughout the experiment, seismic velocity and attenuation of the core sample were measured using the Split Hopkinson Resonant Bar method (Nakagawa, 2012, Rev. Sci. Instr.) at near 1 kHz (500Hz--1.5 kHz), and the CO2 distribution determined via x-ray CT imaging. In contrast to relatively isotropic Mokelumne sand A, Domengine sandstone and Mokelumne sand B cores exhibited CO2 distributions strongly controlled by the bedding planes. During the CO2 injection, P-wave velocity and attenuation of the layered

  17. Extraction of lobetyolin from codonopsis with supercritical CO_2%超临界流体萃取党参中党参炔苷的研究

    Institute of Scientific and Technical Information of China (English)

    刘同举; 李淑芬; 闵江; 包小妹

    2009-01-01

    目的:党参炔苷是党参中开发一条绿色快速的工艺路线,提取党参中的重要的有效成分之一党参炔苷(lobetyolin).方法:本实验对党参中党参炔苷的超临界CO_2萃取工艺进行了研究.采用中心实验设计结合响应曲面法考察了压力、温度、萃取时间和夹带剂用量等因素对党参炔苷得率的影响及其交互作用.结果:确定了夹带剂用量是关键因素,在动态夹带剂乙醇流速为1 mL·min~(-1),常压CO_2流速为2L·min~(-1)30 MPa,60℃下条件下萃取100 min,党参炔苷得率为0.078 6 mg·g~(-1),优于传统超声萃取法.结论:采用带夹带剂的超临界流体萃取党参中党参炔苷是可行的.%Objective: To develop a green and rapid method for extraction of lobetyolin from C. pilosula.Method:Extraction of lobetyolin from C. pilosula with supercritical carbon dioxide in the presence of ethanol was studied. The effects of pressure,temperature,volume of cosolvent and extraction time on efficiency and their interactive relationships were discussed, based on central composite design and response surface methodology (RSM). Result:The key effect factor was volume of cosolvent. The extraction yield of lobetyolin was 0. 078 6 mg·g~(-1) when C. pilosula (40-60 mesh) was extracted at 30 MPa, 60℃ and 2 L·min~(-1)(as CO_2 in normal pressure and temperature) for 100 minutes with supercritical CO_2 and 1 mL·min~(-1) ethanol as dynamic cosolvent. Conclusion: This result is better than that obtained from traditional method. Therefore, the optimized process is valuable for extraction of lobetyotin from C. pilosula.

  18. Comparative studies on exchange reactions of hexafluoroacetylacetonate in bis(hexafluoroacetylacetonato)(dimethyl sulfoxide)dioxouranium(VI) in nonaqueous solvent and supercritical CO(2).

    Science.gov (United States)

    Kachi, Yoshihiro; Kayaki, Yoshihito; Tsukahara, Takehiko; Ikariya, Takao; Ikeda, Yasuhisa

    2008-01-07

    Exchange reactions of hexafluoroacetylacetonate (hfacac) in UO2(hfacac)2DMSO (DMSO = dimethyl sulfoxide) in o-C6D4Cl2 and supercritical CO2 (sc-CO2) have been studied using the NMR line-broadening method to compare reactivity in a nonaqueous solvent with that in sc-CO2. It was found that the exchange rates of hfacac in both systems are dependent on the concentration of the enol isomer ([Henol]) of hexafluoroacetylacetone and become slow with an increase in the concentration of free DMSO ([DMSO]). The exchange reaction between free and coordinated DMSO in UO2(hfacac)2DMSO has been also examined in o-C6D4Cl2 and sc-CO2. As a result, the exchange rate of DMSO was found to depend on [DMSO]. From these results, the hfacac exchange reactions in UO2(hfacac)2DMSO in o-C6D4Cl2 and sc-CO2 were proposed to proceed through the mechanism that the ring-opening for one of two coordinated hfacac in UO2(hfacac)2DMSO is the rate-determining step, and the resulting vacant site is coordinated by the incoming Henol, followed by the proton transfer from Henol to hfacac and the ring closure of unidentate hfacac. The rate constants at 60 degrees C and the activation parameters (DeltaH and DeltaS) for the ring-opening path are 35.8 +/- 3.2 s(-1), 57.8 +/- 2.7 kJ.mol(-1), and -42.9 +/- 7.7 J.mol(-1).K(-1) for the o-C6D4Cl2 system, and 518 +/- 50 s(-1), 18.9 +/- 1.8 kJ.mol(-1), and -138 +/- 5 J.mol(-1).K(-1) for the sc-CO2 system, respectively. Differences in kinetic parameters between sc-CO2 and o-C6D4Cl2 systems were proposed to be attributed to the solute-solvent interactions such as Lewis acid-Lewis base interactions and hydrogen bondings between sc-CO2 and beta-diketones.

  19. Reactivity of Forsterite, Lizardite, and Antigorite in Dry to Water-Saturated Supercritical CO2 - An In Situ Infrared Spectroscopic Investigation

    Science.gov (United States)

    Loring, J. S.; Thompson, C. J.; Wang, Z.; Schaef, H. T.; Felmy, A. R.; Rosso, K. M.

    2010-12-01

    Geologic carbon sequestration (GCS) is a promising technology for reducing anthropogenic emissions of CO2 into the atmosphere. Olivines and serpentines are potentially important mineral phases in GCS because they are widespread in basalt formations and caprocks, are rich in Ca, Mg, and Fe, and react exothermically with CO2 to form carbonate solids. Previous work in aqueous systems has shown that carbonation rates of serpentines are lower than those of olivines, unless heat or acid pretreatments are applied. To the best of our knowledge, the comparative reactivities of olivines and serpentines have not yet been explored in dry to water saturated supercritical CO2 (scCO2) under conditions relevant to geologic sequestration. In this study, we used in situ infrared spectroscopy to investigate the carbonation of forsterite (Mg2SiO4), a representative of the olivine group and two serpentine polymorphs, antigorite and lizardite (Mg3Si2O5(OH)4). Experiments were carried out at 35 °C and 100 bar using a flow-through system equipped with a high-pressure mid-infrared cell. One ZnSe window of the transmission cell was coated with a thin overlayer of the mineral under investigation. Absorbance spectra were recorded as a function of time for 24 hours after exposing the overlayer to scCO2 containing water at concentrations corresponding to 0%, 50% and 95% saturation. Experiments were also performed with an approximately 2-fold excess concentration of water. In these latter experiments, a controlled temperature gradient was used to intentionally condense a liquid water film on the mineral surfaces. Little reaction was observed for the minerals exposed to dry scCO2. At water concentrations of 50% and 95% saturation, a very thin, liquid-like water film was detected on the mineral surface. A relatively minor extent of reaction occurred, and most of the transformation was observed during the first three hours of the experiments. Much greater reactivity was evident when a thicker

  20. Metal Carbonation of Forsterite in Supercritical CO2 and H2O Using Solid State 29Si, 13C NMR Spectroscop

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Ja Hun; Hu, Jian Z.; Hoyt, David W.; Sears, Jesse A.; Wang, Chong M.; Rosso, Kevin M.; Felmy, Andrew R.

    2010-03-11

    Ex situ solid state NMR was used for the first time to study fundamental mineral carbonation processes and reaction extent relevant to geologic carbon sequestration (GCS) using a model silicate mineral forsterite (Mg2SiO4)+supercriticalCO2 with and without H2O. Run conditions were 80 C and 96 atm. 29Si NMR clearly shows that in the absence of CO2, the role of H2O is to hydrolyze surface Mg-O-Si bonds to produce dissolved Mg2+, and mono- and oligomeric hydroxylated silica species. Surface hydrolysis products contain only Q0 (Si(OH)4) and Q1(Si(OH)3OSi) species. An equilibrium between Q0, Q1 and Mg2+ with a saturated concentration equivalent to less than 3.2% of the Mg2SiO4 conversion is obtained at a reaction time of up to 7 days. Using scCO2 without H2O, no reaction is observed within 7 days. Using both scCO2 and H2O, the surface reaction products for silica are mainly Q3 (SiOH(OSi)3) species accompanied by a lesser amount of Q2 (Si(OH)2(OSi)2) and Q4 (Si(OSi)4). However, no Q0 and Q1 were detected, indicating the carbonic acid formation/deprotonation and magnesite (MgCO3) precipitation reactions are faster than the forsterite hydrolysis process. Thus it can be concluded that the Mg2SiO4 hydrolysis process is the rate limiting step of the overall mineral carbonation process. 29Si NMR combined with XRD, TEM, SAED and EDX further reveal that the reaction is a surface reaction with the Mg2SiO4 crystallite in the core and with condensed Q2-Q4 species forming amorphous surface layers. 13C MAS NMR identified a possible reaction intermediate as (MgCO3)4-Mg(OH)2-5H2O. However, at long reaction times only crystallite magnesite MgCO3 products are observed.

  1. Metal Carbonation of Forsterite in Wet Supercritical CO2: The Role of H2O Studied by Solid State C-13 and Si-29 NMR Spectroscopy

    Science.gov (United States)

    Hu, J.; Kwak, J.; Turcu, R. V.; Rosso, K. M.; Ilton, E. S.; Wang, C.; Sears, J. A.; Felmy, A. R.; Hoyt, D. W.

    2010-12-01

    Selected as a model mineral carbonation system for geological carbon sequestration in mafic host rocks, chemical mechanisms of forsterite carbonation in supercritical CO2 containing water varied from dry to well above saturation, including at saturation, were investigated by a combination of solid state NMR (C-13 SP-, CP-MAS, Si-29 SP-, CP-MAS), XRD, TEM and XPS. Run conditions were 80 degrees (C) and 75 bars. Major findings are as follows. At high water contents where a bulk aqueous solution coexisted with water-saturated scCO2, forsterite was converted into magnesite and a separate Mg-free amorphous SiO2 reaction product characterized by highly polymerized oligomeric Q4, and to a lesser extent by Q3 silica species. As the amount of added water was reduced, hydrated intermediate reaction products that did not evolve to magnesite could be identified until at zero water no reaction intermediates or magnesite carbonation products were observed. The intermediate reaction products identified were a complex mixture of partially hydrated/hydroxylated magnesium carbonate species and a variety of surface silica species with low polymerization extent. The intermediates were mainly in an amorphous state, forming a thin layer on the surface. Formation of these intermediate species consumes water by hydrolysis of Mg-O-Si linkages at the forsterite surface as well as by incorporation of water in the lattice. If insufficient water is available, the reaction is found not to proceed far enough to form magnesite and amorphous SiO2. Water in excess of this limit appears necessary for the intermediates to evolve to anhydrous magnesite, a process that is expected to liberate water for continued reaction. Hence, for a given fluid/forsterite ratio there appears to be a water threshold (i.e., the formation of H2O film with sufficient thickness estimated to be between 3.2 and 18.4 nm) above which a significant portion of the water is recycled in an apparent quasi-catalytic role for the

  2. Flow behaviour of supercritical CO2 and brine in Berea sandstone during drainage and imbibition revealed by medical X-ray CT images

    Science.gov (United States)

    Zhang, Yi; Nishizawa, Osamu; Kiyama, Tamotsu; Chiyonobu, Shun; Xue, Ziqiu

    2014-06-01

    We injected Berea sandstone with supercritical CO2 and imaged the results with a medical X-ray computed tomography (CT) scanner. The images were acquired by injecting CO2 into a core of brine-saturated sandstone (drainage), and additional images were acquired during reinjection of brine (imbibition) after drainage. We then analysed the temporal variations of CO2 saturation maps obtained from the CT images. The experiments were performed under a confining pressure of 12 MPa, a pore pressure of 10 MPa and a temperature of 40 °C. Porosity and CO2 saturation were calculated for each image voxel of the rock on the basis of the Hounsfield unit values (CT numbers) measured at three states of saturation: dry, full brine saturation and full CO2 saturation. The saturation maps indicated that the distributions of CO2 and brine were controlled by the sub-core-scale heterogeneities which consisted of a laminated structure (bedding) with high- and low-porosity layers. During drainage, CO2 preferentially flowed through the high-porosity layers where most of the CO2 was entrapped during low flow-rate imbibition. The entrapped CO2 was flushed out when high flow-rate imbibition commenced. Plots of the voxel's CT number against porosity revealed the relationship between fluid replacement and porosity. By reference to the CT numbers at the full brine-saturated stage, differential CT numbers were classified into three bins corresponding to voxel porosity: high, medium and low porosity. Distributions of the differential CT number for the three porosity bins were bimodal and in order with respect to the porosity bins during both drainage and imbibitions; however, the order differed between the two stages. This difference suggested that different replacement mechanisms operated for the two processes. Spatial autocorrelation of CO2 saturation maps on sections perpendicular to the flow direction revealed remarkable changes during passage of the replacement fronts during both drainage and

  3. PREPARATION OF EPA AND DHA ESTERS WITH HIGH PURITY BY SUPERCRITICAL CO2 EXTRACTION AND RECTIFICATION%超临界CO2萃取精馏制取高纯度EPA乙酯和DHA乙酯

    Institute of Scientific and Technical Information of China (English)

    邱榕; 范维澄; 陈钧

    2001-01-01

    Fish oil ethyl esters complexed with aqueous silver nitrate solution were extracted and rectified by supercritical CO2 to obtain DHA ester and EPA ester with high purity. The effects of some independent variables,such as extraction pressure, temperature gradient of rectifying column and programmed pressure,on rectification were investigated.The results showed that programmed pressure is suitable for purification of EPA and DHA esters. Increase of column temperature gradient from bottom to top is one of the key elements in rectification. Furthermore, higher temperature gradient leads to better separation effect.

  4. Experimental and Simulating Study of Supercritical CO2 Extraction of Ginger Essential Oil%超临界二氧化碳萃取生姜油实验研究与数值模拟

    Institute of Scientific and Technical Information of China (English)

    刘学武; 李志义; 陈淑花; 詹世平; 夏远景; 魏勇

    2005-01-01

    An experimental setup for separating ginger essential oil by supercritical fluid extraction is established.The effects of the extraction pressure, temperature, CO2 flow rate and particle size of raw material on the extraction rate are investigated, and the optimum process conditions of supercritical CO2 extraction are determined. A mathematical simulation model is established based on the mass conservation in differential units of extraction bed.The total mass transfer driving force and the equilibrium absorption constant are evaluated by the linear driving force theory. The results from numerical simulation agree well with the experimental data.

  5. Development of Research in Corrosion on Supercritical CO2 Transportation Pipelines%超临界CO2输送管道的腐蚀研究进展

    Institute of Scientific and Technical Information of China (English)

    左甜; 刘小辉; 蒋秀; 周乐平

    2011-01-01

    The Carbon capture and storage which is a leading - edge technology of great potential for reduction of green gas emission, has received great attention of science & technology fields and industries. Whereas, the internal corrosion in CO2 transportation pipeline may become one of the critical issues restricting the development and application of carbon sequestration technology. The importance of carbon sequestration technology for carbon reduction emission is emphasized, and the corrosion laws and mechanisms in supercritical CO2 transportation environment are studied, The properties of supercritical CO2 in CO2 transportation are discussed. The essential difference between supercritical CO2 corrosion in the Carbon Capture and Storage (CCS) and general CO2 corrosion in oil and gas system is analyzed. The impact factors and corrosion control techniques of supercritical CO2 corrosion in transportation are reviewed.%碳捕集与封存(Carbon Capture and Storage,简称CCS)技术是极具潜力的一项减缓温室气体排放的前沿技术,已受到国际科技和产业界的密切关注,其中CO2运输管道的内腐蚀问题可能成为制约碳封存技术发展及应用的关键问题之一。强调了CCS技术对于碳减排的重要性,研究碳钢在超临界CO2运输环境中的腐蚀规律和机理以及CO2输送过程中的超临界CO2的性质显得十分重要。阐述了碳捕集与封存技术(CCS)中超临界CO2输输送管道的腐蚀与油气系统的CO2输腐蚀的本质区别,对输送过程中超临界CO2腐蚀的影响因素进行了分析,并且对腐蚀控制研究动态进行了回顾。

  6. Application of Supercritical CO2 on the Extraction of Functional Components from Winery Wastes%SC-CO2在葡萄酒渣功能性成分提取中的应用

    Institute of Scientific and Technical Information of China (English)

    宋金慧; 李双石; 马越; 曹奇光; 谢国莉

    2014-01-01

    There are large amounts of winery wastes generated in industrial wine production. Winery wastes contain high levels of functional components that can act as antioxidants and have health-promoting activities. Supercritical CO2 extraction technique is a new technique that concludes rectification and extraction processes, by which high and good quality products can be separated. This paper summarizes the supercritical CO2 extraction technological principle, characteristics and its application on the extraction of functional components from winery wastes. It would provide scientific foundations for utilization of winery wastes.%葡萄酒工业产生大量的废弃物即葡萄酒渣,葡萄酒渣富含具有抗氧化活性和医疗保健功能的组分。超临界二氧化碳萃取技术是近年来兴起的一项具有精馏和萃取两过程的高新物质分离精制技术。介绍了超临界二氧化碳萃取的原理、特点及其在葡萄酒渣功能性成分提取中应用的研究进展,旨在为葡萄酒渣的综合利用提供一定的参考和借鉴。

  7. 川芎油在超临界二氧化碳中溶解度的测定与关联%Measurement and Correlation of the Solubility of Ligusticum Chuanxiong oil in Supercritical CO2

    Institute of Scientific and Technical Information of China (English)

    孙永跃; 李淑芬

    2005-01-01

    Extraction of the Ligusticum Chuanxiong oil with supercritical CO2 (SC-CO2) was investigated at the temperatures ranging from 55℃ to 70℃ and pressure from 25 MPa to 35 MPa. The mass of Ligusticum Chuanxiong oil extracted increased with pressure at constant temperature. The initial slope of the extraction was considered as the solubility of oil in SC-CO2. Chrastil equation was used to correlate the solubility data of Ligusticum Chuanxiong oil. An improved Chrastil equation was also presented and was employed to correlate the solubility data. The correlation results show that the values of the average absolute relative deviation are 5.94 % and 3.33%respectively, indicating the improved version has better correlation accuracy than that of Chrastil equation.

  8. Supercritical CO2 Extracting Technology of Garlic Essential Oil and Active Components Analysis%大蒜精油的超临界 CO2萃取技术与有效成分分析

    Institute of Scientific and Technical Information of China (English)

    李羿为; 赖万东

    2013-01-01

      Introduce the garlic essential oil properties and its application in life and production , summarize supercritical CO 2 extraction principle and process characteristics , analyze the technology application and development prospects , and also describe qualitative and quantitative detection methods of garlic essential oil .%  介绍大蒜精油的性质及其在生活生产中的应用,阐述超临界萃取技术的原理及工艺特点,分析其应用现状及发展前景,并介绍了大蒜精油有效成分的定性和定量检测方法。

  9. Antimicrobial Activities of Methanol, Ethanol and Supercritical CO2 Extracts of Philippine Piper betle L. on Clinical Isolates of Gram Positive and Gram Negative Bacteria with Transferable Multiple Drug Resistance.

    Directory of Open Access Journals (Sweden)

    Demetrio L Valle

    Full Text Available Piper betle L. has traditionally been used in alternative medicine in different countries for various therapeutic purposes, including as an anti-infective agent. However, studies reported in the literature are mainly on its activities on drug susceptible bacterial strains. This study determined the antimicrobial activities of its ethanol, methanol, and supercritical CO2 extracts on clinical isolates of multiple drug resistant bacteria which have been identified by the Infectious Disease Society of America as among the currently more challenging strains in clinical management. Assay methods included the standard disc diffusion method and the broth microdilution method for the determination of the minimum inhibitory concentration (MIC and the minimum bactericidal concentrations (MBC of the extracts for the test microorganisms. This study revealed the bactericidal activities of all the P. betle leaf crude extracts on methicillin-resistant Staphylococcus aureus (MRSA, vancomycin-resistant Enterococcus (VRE, extended spectrum β-lactamase-producing Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae, and metallo-β-lactamase-producing Pseudomonas aeruginosa and Acinetobacter baumannii, with minimum bactericidal concentrations that ranged from 19μg/ml to 1250 μg/ml. The extracts proved to be more potent against the Gram positive MRSA and VRE than for the Gram negative test bacteria. VRE isolates were more susceptible to all the extracts than the MRSA isolates. Generally, the ethanol extracts proved to be more potent than the methanol extracts and supercritical CO2 extracts as shown by their lower MICs for both the Gram positive and Gram negative MDRs. MTT cytotoxicity assay showed that the highest concentration (100 μg/ml of P. betle ethanol extract tested was not toxic to normal human dermal fibroblasts (HDFn. Data from the study firmly established P. betle as an alternative source of anti-infectives against multiple drug resistant

  10. Antimicrobial Activities of Methanol, Ethanol and Supercritical CO2 Extracts of Philippine Piper betle L. on Clinical Isolates of Gram Positive and Gram Negative Bacteria with Transferable Multiple Drug Resistance.

    Science.gov (United States)

    Valle, Demetrio L; Cabrera, Esperanza C; Puzon, Juliana Janet M; Rivera, Windell L

    2016-01-01

    Piper betle L. has traditionally been used in alternative medicine in different countries for various therapeutic purposes, including as an anti-infective agent. However, studies reported in the literature are mainly on its activities on drug susceptible bacterial strains. This study determined the antimicrobial activities of its ethanol, methanol, and supercritical CO2 extracts on clinical isolates of multiple drug resistant bacteria which have been identified by the Infectious Disease Society of America as among the currently more challenging strains in clinical management. Assay methods included the standard disc diffusion method and the broth microdilution method for the determination of the minimum inhibitory concentration (MIC) and the minimum bactericidal concentrations (MBC) of the extracts for the test microorganisms. This study revealed the bactericidal activities of all the P. betle leaf crude extracts on methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), extended spectrum β-lactamase-producing Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae, and metallo-β-lactamase-producing Pseudomonas aeruginosa and Acinetobacter baumannii, with minimum bactericidal concentrations that ranged from 19μg/ml to 1250 μg/ml. The extracts proved to be more potent against the Gram positive MRSA and VRE than for the Gram negative test bacteria. VRE isolates were more susceptible to all the extracts than the MRSA isolates. Generally, the ethanol extracts proved to be more potent than the methanol extracts and supercritical CO2 extracts as shown by their lower MICs for both the Gram positive and Gram negative MDRs. MTT cytotoxicity assay showed that the highest concentration (100 μg/ml) of P. betle ethanol extract tested was not toxic to normal human dermal fibroblasts (HDFn). Data from the study firmly established P. betle as an alternative source of anti-infectives against multiple drug resistant bacteria.

  11. Supercritical CO2 fluid-foaming of polymers to increase porosity: a method to improve the mechanical and biocompatibility characteristics for use as a potential alternative to allografts in impaction bone grafting?

    Science.gov (United States)

    Tayton, Edward; Purcell, M; Aarvold, A; Smith, J O; Kalra, S; Briscoe, A; Shakesheff, K; Howdle, S M; Dunlop, D G; Oreffo, R O C

    2012-05-01

    Disease transmission, availability and cost of allografts have resulted in significant efforts to find an alternative for use in impaction bone grafting (IBG). Recent studies identified two polymers with both structural strength and biocompatibility characteristics as potential replacements. The aim of this study was to assess whether increasing the polymer porosity further enhanced the mechanical and cellular compatibility characteristics for use as an osteogenic biomaterial alternative to allografts in IBG. Solid and porous poly(DL-lactide) (P(DL)LA) and poly(DL-lactide-co-glycolide) (P(DL)LGA) scaffolds were produced via melt processing and supercritical CO(2) foaming, and the differences characterized using scanning electron microscopy (SEM). Mechanical testing included milling and impaction, with comparisons made using a shear testing rig as well as a novel agitation test for cohesion. Cellular compatibility tests for cell number, viability, and osteogenic differentiation using WST-1 assays, fluorostaining, and ALP assays were determined following 14 day culture with skeletal stem cells. SEM showed excellent porosity throughout both of the supercritical-foam-produced polymer scaffolds, with pores between 50 and 200 μm. Shear testing showed that the porous polymers exceeded the shear strength of allograft controls (P<0.001). Agitation testing showed greater cohesion between the particles of the porous polymers (P<0.05). Cellular studies showed increased cell number, viability, and osteogenic differentiation on the porous polymers compared to solid block polymers (P<0.05). The use of supercritical CO(2) to generate porous polymeric biodegradable scaffolds significantly improves the cellular compatibility and cohesion observed compared to non-porous counterparts, without substantial loss of mechanical shear strength. These improved characteristics are critical for clinical translation as a potential osteogenic composite for use in IBG.

  12. 超临界CO2对碳纤维环氧树脂的界面性能的改善%Performance Improvements of Supercritical CO2 on Interface Property of the Carbon Fiber/Epoxy Resin

    Institute of Scientific and Technical Information of China (English)

    刘魁; 孟令辉; 曾竟成; 冯学斌

    2012-01-01

    为提高碳纤维/环氧树脂复合材料的界面结合性能,采用超临界CO2对碳纤维表面进行处理.结果表明:在处理后碳纤维的单丝拉伸强度下降2.81%,碳纤维/环氧树脂界面剪切强度和层间剪切强度在处理后分别提高25.19%和17.11%.通过对碳纤维原子力显微镜(AFM)观察,经过处理的碳纤维表面粗糙度增加明显,同时对复合材料层间剪切断口端面用扫描电子显微镜(SEM)观察,经过超临界CO2处理后的碳纤维与环氧树脂的复合性能得到改善.%To improve the carbon fiber/epoxy resin composite' s interfacial bonding performance; treatment of supercritical CO2 was used to the carbon fiber surface.The single strands of carbon fiber tensile strength decreased by 2.81% and interfacial shear strength and interlaminar shear strength of the carbon fiber/ epoxy resin composite improved by 25.19% and 17.Irrespectively.By atomic force microscopy (AFM) investigation on the carbon fiber surface,it showed that surface roughness increased significantly,while through scanning electron microscope(SEM)investigation on the fracture surface of composite after treatment,it showed that the performance of carbon fiber and epoxy composite improved after the treatment of supercritical CO2.

  13. 超临界CO_2萃取与水蒸汽减压蒸馏萃取柑桔皮精油比较%Comparison Study on Extraction of Essential Oil from Peel of Citrus by Supercritical CO_2 and Vacuum Distillation

    Institute of Scientific and Technical Information of China (English)

    李燕; 黄萧逸

    2012-01-01

    使用超临界CO2萃取法和水蒸汽减压蒸馏萃取柑桔皮精油,两种方法精油收率相当,最高收率均为1.2%。但水蒸汽减压蒸馏法提取的精油质量好,为浅黄色流动性液体,气味具有新鲜柑桔皮的清香,流程简单,超临界CO2萃取所得产品质量差,流动性差,为深黄色半流动性液体,杂质较多。%Essential oil was extracted from peel of citrus by the methods of supercritical CO2 extraction and steam distillation extraction.The extraction yield of two methods was equal,the highest yield was 1.2%.The quality of the volatile oil extracted by steam distillation extraction was better than those extracted by supercritical CO2,and was light yellow fluidity liquid and smell fresh citrus scent.Technological process of steam distillation extraction was simple than that of supercritical CO2 extraction.The essential oi extracted by supercritical CO2 was dark yellow semi-liquid liquid impurities.

  14. 超临界CO 2萃取脱皮菜籽饼粕油脂的可行性%Feasibility of extraction of oil from dehulled rapeseed cake using supercritical CO2

    Institute of Scientific and Technical Information of China (English)

    万楚筠; 胡双喜; 李文林; 邓乾春; 黄凤洪

    2014-01-01

    The double-low rapeseed contains ≤2%erucic acid in its oil and ≤35μmol/g of dry meal. The oil of double-low rapeseed contains very low levels of saturated fatty acids (6%), high levels of oleic acid (≥60%), and intermediate levels of linoleic and linolenic acids (20%and 10%, respectively). Because of its higher oil content and numerous agricultural advantages, double-low rapeseed is getting worldwide attention. The rapeseed oil, which was extracted by a traditional process with pre-press and solvent extraction, is of bad quality. Commercial hexane, which has been used as a solvent for crude edible oil extraction, has toxicological and environmental safety issues. Carbon dioxide in its supercritical state has properties and extraction capacities very similar to liquids. Supercritical carbon dioxide extraction is a new technique for oil extraction and is similar to conventional solvent extraction in that the material to be extracted is withdrawn from the substrate by using a solvent. In its supercritical state, carbon dioxide is the most commonly used supercritical solvent due to its nontoxicity, non-flammability, low cost, availability in bulk quantities, ease of removal from the extracted materials, and low critical temperature and pressure (31.06 ℃ and 7.38 MPa, respectively). To improve the additional value of oils and meals obtained from the cold press cake of double-low dehulled rapeseed, supercritical CO 2 is used to extract double-low rapeseed oil and then the quality of the oil and meal obtained is studied. The affection of factors, which includes extraction pressure, temperature, and time effecting on oil yield, is investigated by Box-Behnken’s response surface methodology. The model equation for predicting the optimum response values is established by Design Expert software. The adequacy of the model equation for predicting the optimum response values was effectively verified by the validation. The experiment result indicates that affection of

  15. Physiological Demands of Simulated Off-Road Cycling Competition.

    Science.gov (United States)

    Smekal, Gerhard; von Duvillard, Serge P; Hörmandinger, Maximilian; Moll, Roland; Heller, Mario; Pokan, Rochus; Bacharach, David W; LeMura, Linda M; Arciero, Paul

    2015-12-01

    The purpose of the study was to measure the demands of off-road cycling via portable spirometry, leg-power output (PO), heart rate (HR) and blood lactate (BLa) concentration. Twenty-four male competitive cyclists (age: 29±7.2 yrs, height: 1.79 ± 0.05 m, body mass: 70.0 ± 4.9 kg, VO2peak: 64.9 ± 7.5 ml·kg(-1)·min(-1)) performed simulated mountain bike competitions (COMP) and laboratory tests (LabT). From LabT, we determined maximal workload and first and second ventilatory thresholds (VT1, VT2). A high-performance athlete (HPA) was used for comparison with three groups of subjects with different sport-specific performance levels. Load profiles of COMP were also investigated during uphill, flat and downhill cycling. During the COMP, athletes achieved a mean oxygen uptake (VO2COMP) of 57.0 ± 6.8 ml·kg(-1)·min(-1) vs. 71.1 ml·kg(-1)·min(-1) for the HPA. The POCOMP was 2.66±0.43 W·kg(-1) and 3.52 W·kg(-1) for the HPA. POCOMP, VO2COMP and HRCOMP were compared to corresponding variables at the VT2 of LabT. LabT variables correlated with racing time (RTCOMP) and POCOMP (p cycling is characterized by high oxygen costs due to the high muscle mass simultaneously working to fulfill the demands of this kind of sports.Heart rate and blood lactate concentration measures are not sensitive enough to assess the energy requirements of COMP. Therefore, respiratory gas and power output measures are helpful to provide new information to physiological profile of cross- country cycling.An excellent cycling-specific capacity is a prerequisite for successful off-road cycling.Data determined from LabT might be utilized to describe semi-specific abilities of MB- athletes on a cycle ergometer, while data originating from COMP might be useful when designing a mountain bike specific training.

  16. Review on Corrosion Behaviors of Steels under Supercritical CO2 Condition%超临界CO2条件下钢的腐蚀行为研究进展

    Institute of Scientific and Technical Information of China (English)

    张玉成; 屈少鹏; 庞晓露; 高克玮

    2011-01-01

    低压CO2腐蚀规律已经被人们广泛认识,而超临界CO2腐蚀方面的研究却非常有限。国内外的研究主要集中在钢在超临界CO2环境中的腐蚀速率、腐蚀产物膜的结构、形貌、组成及电化学行为等。然而,现有的研究均未涉及到超临界CO2腐蚀机理问题。本文综述了目前国内外超临界CO2条件下钢的腐蚀行为的研究成果,指出了现有研究中的不足,并对超临界CO2腐蚀的研究前景进行了展望,期望能对科研工作者全面了解超临界CO2腐蚀提供参考和借鉴,并能够为油气工业中管道的选材提供理论指导。%The CO2 corrosion under low partial pressure has been recognized widely, but the researches on supercritical carbon dioxide (SC CO2) corrosion were very limited. By far, investigations on steel corrosion under SC CO2 conditions were mainly about the corrosion rate, structure, morphology and composition of corrosion scales, and the electrochemical behaviors. However, present studies were not related to the corrosion mechanism in SC CO2. This paper reviews the research results on corrosion behaviors of steel under supercritical COe conditions, points out the shortcomings in the present investigations and finally looks forward to the research prospects on supercritical CO2 corrosion. It is expected that this paper can not only provide reference for the workers in the field of supercritical CO2 corrosion, but also be served as a theoretical guidance for materials selection in oil and gas industry.

  17. Wettability-Water/brine Film Thickness Relationship and the Effect of Supercritical CO2 Pre-contact for CO2/brine/mineral Systems under Geologic CO2 Sequestration Conditions: Insights from Molecular Dynamics Simulations

    Science.gov (United States)

    Chen, C.; Song, Y.; Li, W.

    2016-12-01

    Injection CO2 into deep saline aquifers is one of the main options for geologic carbon sequestration (GCS). A successful GCS in saline aquifers requires full knowledge about CO2/brine/mineral systems under sequestration conditions to reduce uncertainties during subsurface storage of CO2. Adsorbed water film thickness and wettability on mineral surfaces are two key characteristics for CO2/brine/mineral systems. Wettability and water/brine film thickness have been measured experimentally and predicted by molecular simulation (MD) studies. However, these studies only consider the films apart from contact angles. Investigations on wettability for CO2/brine/mineral systems only consider contact angles without measurements on film thickness. The relationship between film thicknesses with water contact angles is open to questions. In this paper, MD simulations have been performed to investigate the interrelationship between water film thicknesses and water contact angles. Three silica surfaces with different silanol group number densities (Q3, Q3-50%, Q3/Q4) were selected to represent silica surfaces with different wettabilities. We found that as water contact angle increases, the film thickness decreases. We also studied the effect of CO2-mineral pre-contact and found that: on Q3 surface, if a CO2 bubble was pre-contacted with the surface, it can remain on the surface without forming a water film; however, if a CO2 bubble was placed certain distances away from the surface, it formed a water film. Wettability analysis revealed that on the same surface, water contact angle was larger when there was no water film. These findings show that on some silica surfaces, water film may be destroyed by supercritical CO2 even the silica surfaces are hydrophilic. A water film rupture mechanism was propsed for CO2 adhesion on mineral surfaces [Wang (2013) Environ. Sci. Technol. 47, 11858; Zhang (2016) Environ. Sci. Technol. Lett. 10.1021/acs.estlett.5b00359]. The rupture of water film

  18. 超临界 CO2萃取烟草精油的工艺研究%Study on the Extraction Process of Essential Oil from Tobacco by Supercritical CO2 Fluid

    Institute of Scientific and Technical Information of China (English)

    刘亚娟; 刘芸; 王志祥

    2014-01-01

    Using tobacco as raw material,with the extraction rate of essential oil and neophytadiene,the quality of essential oil as evaluation indexes,the effects of volume fraction and flux of modifier,extraction pres-sure,extraction temperature,supercritical CO2 fluid flux,extraction time on extraction efficiency were investiga-ted by single factor experiment.Based on the results obtained,the optimum process parameters were determined by orthogonal experiment as follows:with 94% ethanol at the flux of 0.04 mL·min-1 as modifier,extraction pressure was 25 MPa,extraction temperature was 50 ℃,supercritical CO2 fluid flux was 2.0 L·min-1 ,extrac-tion time was 3.0 h.Under the optimal conditions,the essential oil was golden in color and had fewer residues, the extraction rate of essential oil and neophytadiene was 37.58 mg·g-1 and 4.045 mg·g-1 ,respectively.%以烟草为材料,以精油提取率、新植二烯提取率、精油品质为评价指标,通过单因素实验考察夹带剂乙醇的体积分数、夹带剂流量、萃取压力、萃取温度、CO2流量、萃取时间等因素对萃取效果的影响。在此基础上,通过正交实验优选萃取工艺条件为:94%乙醇为夹带剂、夹带剂流量0.04 mL·min-1、萃取压力25 MPa、萃取温度50℃、CO2流量2.0 L·min-1、萃取时间3.0 h,在此条件下萃取的精油金黄透亮,夹带剂残留少,精油提取率为37.58 mg·g-1,新植二烯提取率为4.045 mg·g-1。

  19. 超临界CO2萃取云南松松子油提取工艺研究%Extraction Technology of Pinus yunnanensis Franch Nut Oil by Supercritical CO 2 Fluid Extraction

    Institute of Scientific and Technical Information of China (English)

    李林开

    2014-01-01

    本试验采用超临界CO2萃取云南松松子油,以萃取温度、萃取压力和萃取时间3个因素进行单因素试验,在单因素试验结果的基础上,利用响应面法中的Box-Behnken和中心旋转组合设计对超临界CO2萃取云南松松子油的提取工艺条件进行了优化。各个条件均做3次重复试验,以平均值作为最后结果。试验结果表明:萃取温度、萃取压力和萃取时间3个因素对松子出油率影响都显著。经过验证性试验后,最终得到超临界CO2萃取云南松松子油的最佳工艺条件为:萃取温度36.7℃、萃取压力40.6MPa 和萃取时间112.6min,在最佳条件下的出油率24.68%。%Oil extraction from Pinus yunnanensis Franch seeds with supercritical CO2 fluid was studied. Based on results of single factor experiment, extraction process conditions were optimized by using Box-Behnken and central com-posite rotatable design. Each condition was repeated three times, and average value was taken as final result. Results showed that temperature, pressure and time of these three factors were significant effects on pine nut oil yield. Optimal operation conditions was supercritical CO2 fluid extraction temperature at 36.7℃, pressure 40.6MPa and time 112.6min. Oil yield was 24.68%under optimum conditions.

  20. Attachment and growth of fibroblasts on poly(L-lactide/epsilon-caprolactone) scaffolds prepared in supercritical CO2 and modified by polyethylene imine grafting with ethylene diamine-plasma in a glow-discharge apparatus.

    Science.gov (United States)

    Aydin, H M; Türk, M; Calimli, A; Pişkin, E

    2006-09-01

    In this study, a copolymer of L-lactide and epsilon-caprolactone (Mn: 73,523, Mw: 127,990 and PI: 1.74) was synthesized by ring-opening polymerization by using stannous octoate as the catalyst. FTIR, 1H-NMR and DSC confirmed the copolymer formation. The copolymer films were prepared and a novel method was developed to produce highly porous sponges for potential use in tissue engineering. Films were subjected to supercritical CO2 at 3300 psi and 70 degrees C to create porous structures for production of possible tissue engineering scaffolds. The pore sizes were in the range of 40-80 microm. The copolymer films were pre-wetted with polyethylene imine (PEI) and then treated with ethylene diamine (EDA)-plasma in glow-discharge apparatus. Gas plasma surface modification of three-dimensional scaffolds fabricated by supercritical carbon dioxide technique was demonstrated to enhance cell adhesion, proliferation, and differentiation over 6 days in culture using L929 fibroblast cell line. Alkaline phosphatase (ALP) activity and glucose uptake in cell culture medium were followed in the cell culture experiments. Fibroblastic cell attachment and growth on the EDA-plasma treated scaffolds were rather low. However, both cell attachment and growth were significantly increased by PEI pre-treatment before EDA-plasma. The changes in ALP activity and glucose uptake also supported the cell growth behavior on these PEI and EDA-plasma treated scaffolds.

  1. Process optimization of total flavonoids from chuan bergamot by supercritical CO2 extraction%川佛手中总黄酮的超临界CO2萃取工艺优化

    Institute of Scientific and Technical Information of China (English)

    邓祥; 黄小梅; 吴狄

    2014-01-01

    采用超临界CO2萃取技术提取川佛手中的总黄酮,通过单因素分析和正交试验,确定了川佛手中总黄酮的最佳提取工艺参数,即萃取压力为30 MPa,萃取温度为50℃,料液比为100:120 g/mL和萃取时间为2.0 h,在此条件下总黄酮的萃取率达到3.79%.%The total flavonoids was extracted from Chuan Bergamot by supercritical CO2 extraction. The optimal parameters were determined as follows:extraction pressure was 30 MPa;extraction temperature was 50 ℃;solid-liquid ratio was 100:120( g/mL)and extraction time was 2. 0 h by single factor tests and orthogonal experiments. Under these conditions,the extraction yield of total flavonoids is 3. 79%.

  2. 乳香挥发油的超临界CO2萃取工艺研究%Study on supercritical CO2 extraction technology of frankincense essential oil

    Institute of Scientific and Technical Information of China (English)

    郭志军; 胡凯莉; 奉建芳

    2011-01-01

    Objective To optimize the technology for extracting the frankincense essential oil by supercritical CO2 extraction.Methods The orthogonal test was adopted, and the factors such as pressure, temperature and CO2 flow were investigated for optimizing the processes with the volatile oil extraction rate as measurement indicators.Results The better extraction technology was that the extraction pressure was 15MPa, the temperature was 35℃, the CO2 flow was 30L/h.Conclusion The technology is stable and feasible, and lays the foundation for further development of the frankincense essential oil.%目的 优化超临界CO2流体萃取技术提取乳香挥发油的工艺.方法 采用正交试验,以挥发油萃取率为考查指标,研究超临界CO2流体萃取乳香挥发油过程中压力、温度、CO2流量的影响.结果 确定的较佳提取工艺是压力15MPa,温度35℃,CO2流量30L/h.结论 该工艺稳定可行,为乳香挥发油的进一步开发奠定基础.

  3. 超临界CO2萃取神香草精油的工艺研究%Study on the Supercritical CO2 Extraction Technology of Essential Oil of Hyssopus Officinalis

    Institute of Scientific and Technical Information of China (English)

    吴晓菊

    2015-01-01

    研究超临界CO2萃取神香草精油的工艺,探讨萃取压力、温度、时间和CO2流量对神香草精油得率的影响,正交试验确定最佳工艺条件,各因素对神香草精油得率影响程度是:萃取压力>CO2流量>萃取温度>萃取时间.优化的工艺条件为萃取压力12 MPa、温度40℃、CO2流量20 L/h、萃取时间90 min,神香草精油得率为2.558%.%Study of supercritical CO2 extraction technology of essential oil of Hyssopus officinalis, extraction pressure, temperature,time and flow rate on the yield of essential oil Hyssopus officinalis CO2 effect,orthogonal experiment to determine the optimal process conditions,the factors on the yield of essential oil Hyssopus officinalis:influence of extraction pressure>CO2>extraction temperature,extraction time flow. Optimization of process conditions for the extraction pressure,12 MPa;extraction temperature,40 ℃ ;CO2 flow,20 L/h;extraction time,90 min;hyssop oil rate was 2.558%.

  4. 薄荷挥发油超临界CO2萃取工艺参数的研究%Study on Extraction of Volatile Oil from Mentha haplocalyx by Supercritical CO2 Method

    Institute of Scientific and Technical Information of China (English)

    任吉君; 王艳; 周荣; 文素珍; 伍彩旺

    2011-01-01

    The pressure, temperature and time of extracting volatile oil from Asian mint by supercritical CO2 method were studied through orthogonal experiment. The results showed that pressure has the greatest impact on extracting ratio; while time had minimal impact. The optimized extraction conditions were, pressure, 12Mpa; temperature, 55℃; time 1.5h.%以亚洲薄荷作为试验材料,采用超临界CO2萃取法,运用正交设计,针对萃取压力、萃取温度和萃取时间3个因素对薄荷挥发油萃取的影响进行了研究.结果表明,对薄荷挥发油萃取量的影响从大到小依次为萃取压力、萃取温度、萃取时间,超临界CO2萃取薄荷挥发油的最佳工艺参数组合为A3B2C2,即萃取压力12 MPa、萃取温度50℃、萃取时间1-5 h.

  5. 超临界CO2萃取茶叶中咖啡碱工艺研究%Preparation of Caffeine from Tea by supercritical CO2 extraction

    Institute of Scientific and Technical Information of China (English)

    赵旭壮; 郭维强; 唐远谋; 赵宇

    2011-01-01

    The caffeine was extracted from tea by supercritical CO2 extraction technology in this paper. The caffeine was measured by ultraviolet spectrophotometry method. The extracting rate of the caffeine was chosen as the detective index and the optimum extraction conditions were investigated. The orthogonal test was used to investigate the effects of pressure, temperature, extract time, the species of cosolvent on the extracting rate of the caffeine. The results indicated that when using 30% ethanol as cosolvent, extracting pressure was 25MPa ,at 4CC for 4h,The extracting rate of the caffeine was up to 3.95%.%以茶叶为原料,采用超临界CO2萃取技术提取咖啡碱,用紫外分光光度法测定咖啡碱含量,采用正交试验设计考察了压力、温度、时间和夹带剂种类对咖啡碱提取率的影响.结果表明:30%乙醇做夹带剂,萃取温度为40℃,萃取压力为25MPa,萃取4h,此工艺条件下咖啡碱的提取率为3.95%.

  6. Competition between microstructure and defect in multiaxial high cycle fatigue

    Directory of Open Access Journals (Sweden)

    F. Morel

    2015-07-01

    Full Text Available This study aims at providing a better understanding of the effects of both microstructure and defect on the high cycle fatigue behavior of metallic alloys using finite element simulations of polycrystalline aggregates. It is well known that the microstructure strongly affects the average fatigue strength and when the cyclic stress level is close to the fatigue limit, it is often seen as the main source of the huge scatter generally observed in this fatigue regime. The presence of geometrical defects in a material can also strongly alter the fatigue behavior. Nonetheless, when the defect size is small enough, i.e. under a critical value, the fatigue strength is no more affected by the defect. The so-called Kitagawa effect can be interpreted as a competition between the crack initiation mechanisms governed either by the microstructure or by the defect. Surprisingly, only few studies have been done to date to explain the Kitagawa effect from the point of view of this competition, even though this effect has been extensively investigated in the literature. The primary focus of this paper is hence on the use of both FE simulations and explicit descriptions of the microstructure to get insight into how the competition between defect and microstructure operates in HCF. In order to account for the variability of the microstructure in the predictions of the macroscopic fatigue limits, several configurations of crystalline orientations, crystal aggregates and defects are studied. The results of each individual FE simulation are used to assess the response at the macroscopic scale thanks to a probabilistic fatigue criterion proposed by the authors in previous works. The ability of this criterion to predict the influence of defects on the average and the scatter of macroscopic fatigue limits is evaluated. In this paper, particular emphasis is also placed on the effect of different loading modes (pure tension, pure torsion and combined tension and torsion on

  7. Maximal strength training improves cycling economy in competitive cyclists.

    Science.gov (United States)

    Sunde, Arnstein; Støren, Oyvind; Bjerkaas, Marius; Larsen, Morten H; Hoff, Jan; Helgerud, Jan

    2010-08-01

    The purpose of the present study was to investigate the effect of maximal strength training on cycling economy (CE) at 70% of maximal oxygen consumption (Vo2max), work efficiency in cycling at 70% Vo2max, and time to exhaustion at maximal aerobic power. Responses in 1 repetition maximum (1RM) and rate of force development (RFD) in half-squats, Vo2max, CE, work efficiency, and time to exhaustion at maximal aerobic power were examined. Sixteen competitive road cyclists (12 men and 4 women) were randomly assigned into either an intervention or a control group. Thirteen (10 men and 3 women) cyclists completed the study. The intervention group (7 men and 1 woman) performed half-squats, 4 sets of 4 repetitions maximum, 3 times per week for 8 weeks, as a supplement to their normal endurance training. The control group continued their normal endurance training during the same period. The intervention manifested significant (p < 0.05) improvements in 1RM (14.2%), RFD (16.7%), CE (4.8%), work efficiency (4.7%), and time to exhaustion at pre-intervention maximal aerobic power (17.2%). No changes were found in Vo2max or body weight. The control group exhibited an improvement in work efficiency (1.4%), but this improvement was significantly (p < 0.05) smaller than that in the intervention group. No changes from pre- to postvalues in any of the other parameters were apparent in the control group. In conclusion, maximal strength training for 8 weeks improved CE and efficiency and increased time to exhaustion at maximal aerobic power among competitive road cyclists, without change in maximal oxygen uptake, cadence, or body weight. Based on the results from the present study, we advise cyclists to include maximal strength training in their training programs.

  8. CYCLING EFFICIENCY IN TRAINED MALE AND FEMALE COMPETITIVE CYCLISTS

    Directory of Open Access Journals (Sweden)

    James Hopker

    2010-06-01

    Full Text Available The aim of this study was to examine differences in cycling efficiency between competitive male and female cyclists. Thirteen trained male (mean ± SD: 34 ± 8 yr, 74.1 ± 6.0 kg, Maximum Aerobic Power (MAP 414 ± 40 W, VO2max 61.3 ± 5.4 ml·kg-1·min-1 and 13 trained female (34 ± 9 yr, 60.1 ± 5.2 kg, MAP 293 ± 22 W, VO2max 48.9 ± 6.1 ml·kg-1·min-1 competitive cyclists completed a cycling test to ascertain their gross efficiency (GE. Leg and lean leg volume of all cyclists was also measured. Calculated GE was significantly higher in female cyclists at 150W (22.5 ± 2.1 vs 19.9 ± 1. 8%; p < 0.01 and 180W (22.3 ± 1.8 vs 20.4 ± 1.5%; p = 0.01. Cadence was not significantly different between the groups (88 ± 6 vs 91 ± 5 rev·min-1. Lean leg volume was significantly lower for female cyclists (4.04 ± 0.5 vs 5.51 ± 0.8 dm3; p < 0.01 and was inversely related to GE in both groups at 150 and 180W (r = -0.59 and -0.58; p < 0.05. Lean leg volume was shown to account for the differences in GE between the males and females. During an "unloaded" pedalling condition, male cyclists had a significantly higher O2 cost than female cyclists (1.0 ± 0.1 vs 0.7 ± 0.1 L·min-1; p < 0.01, indicative of a greater non-propulsive cost of cycling. These results suggest that differences in efficiency between trained male and female cyclists can be partly accounted for by sex-specific variation in lean leg volume

  9. CO2超临界萃取技术对金枪鱼油挥发性成分的分析%The Analysis of the Effect of Supercritical CO2 Extraction Technology on Volatile Component of Tuna Oils

    Institute of Scientific and Technical Information of China (English)

    王亚男; 季晓敏; 黄健; 王求娟; 陈义芳; 夏静波; 苏秀榕

    2015-01-01

    Based on the existing evaluation indexes of oil oxidation degree,supercritical CO2 extraction technol-ogy was used to refine crude fish oil.Electronic nose and headspace -solid phase micro -extraction (HS -SPME) coupled with gas chromatography -mass spectrometry (GC -MS)were used to analyze the volatiles of tuna fish oil which was extracted differently.The results showed that the AV and POV of the products of fish oil met the require-ments of industry standard,and the AV was the lowest by 32 ℃,20 MPa ,the POV was the lowest by 32 ℃,30 MPa and 40 ℃,20 MPa,and electronic nose can be sensitive to detect the volatiles change of fish oil.The volatiles of crude fish oil which were tested by 32 ℃,20 MPa、32 ℃,30 MPa and 40 ℃,20 MPa were significantly different by PCA and LDA methods.There were 46,19,12,and 23 kinds of volatile compounds including acids,aldehydes,ke-tones,and hydrocarbons,alcohols,esters,as well as a number of heterocyclic compounds,amines.The odor which may affect fish oil including aldehydes,ketones,amines,etc,were removed up to 100% by using supercritical CO2 extraction technology,besides,the acids were removed efficiently.%采用超临界 CO2萃取技术精制金枪鱼粗鱼油,依据现有对油脂氧化程度的评价指标:过氧化值(POV)和酸值(AV),运用电子鼻和顶空固相微萃取-气质联用法对不同萃取条件下的鱼油进行分析。结果表明,超临界 CO2精制的鱼油酸值和过氧化值符合水产行业标准对精制鱼油的要求,32℃,20 MPa 酸值最小,30 MPa 过氧化值最小。电子鼻能够快速、灵敏的检测到鱼油中挥发性物质的变化,通过 PCA 和 LDA 方法分析原鱼油、32℃,20 MPa、32℃,30 MPa 和40℃,20 MPa 条件精制的鱼油挥发性物质明显不同,利用 GC -MS分别检测出46、19、12和23种挥发性物质,包括酸类、醛类、烃类、酮类、醇类、酯类,还有少量杂环化合物、胺类等。超临界 CO2

  10. 竹纤维改性聚丙烯超临界CO2发泡性能的研究%INVESTIGATION OF PP/BAMBOO FIBER BLEND FOAMS USING SUPERCRITICAL CO2

    Institute of Scientific and Technical Information of China (English)

    王传宝; 应三九; 肖正刚

    2011-01-01

    为了提高竹纤维的分散性,借鉴打浆造纸法制备得到了已表面处理的竹纤维和聚丙烯纤维的复合材料,并在扫描电镜下对复合材料样品的断面进行了表征.结果表明,打浆造纸法这种工艺很好地解决了竹纤维在聚丙烯中的分散,得到了竹纤维分布均匀的竹纤维/聚丙烯复合材料;并以竹纤维含量为25%的复合材料作为超临界CO2发泡的研究对象,根据异相成核机理通过快速降压法制备得到了竹纤维/聚丙烯发泡材料,并探讨了发泡工艺条件(饱和压力、饱和时间和饱和温度)对泡孔参数的影响.用扫描电镜对发泡样品的泡孔结构进行了表征,结果表明,竹纤维的加入大大改善了聚丙烯的发泡能力,得到了泡孔尺寸均一、分布均匀的竹纤维/聚丙烯发泡材料,泡孔直径最小达到5.24 μm时,泡孔密度则达到最大值1.92 × 109 cells/cm3.%In order to solve the problem of the dispersion of bamboo fiber, the preparation of the surface treated bamboo fiber and polypropylene composite was carried out in reference to the way of papermaking. The fracture surface of the composite was characterized by the scanning electron microscope. The result showed: the processes of papermaking method solved the problem of the dispersion of bamboo fiber in the composite, and obtained the uniform bamboo fiber distribution of the bamboo fiber/PP composite materials. The composites which contained 25 wt% bamboo fiber were autoclave-foamed in a batch process in supercritical CO2 according to the heterogeneous nucleation mechanism using supercritical CO2 as physical blowing agents, and the influences of the foam process conditions ( such as saturated pressure, saturated time and saturated temperature) on the bubble pore parameters were discussed. Using a scanning microscope,the cell structures of the foaming samples were also investigated, the result indicated: the bamboo fiber had a great positive impact on

  11. Physiological Demands of Simulated Off-Road Cycling Competition

    Directory of Open Access Journals (Sweden)

    Gerhard Smekal, Serge P. von Duvillard, Maximilian Hörmandinger, Roland Moll, Mario Heller, Rochus Pokan, David W. Bacharach, Linda M. LeMura, Paul Arciero

    2015-12-01

    Full Text Available The purpose of the study was to measure the demands of off-road cycling via portable spirometry, leg-power output (PO, heart rate (HR and blood lactate (BLa concentration. Twenty-four male competitive cyclists (age: 29±7.2 yrs, height: 1.79 ± 0.05 m, body mass: 70.0 ± 4.9 kg, VO2peak: 64.9 ± 7.5 ml·kg-1·min-1 performed simulated mountain bike competitions (COMP and laboratory tests (LabT. From LabT, we determined maximal workload and first and second ventilatory thresholds (VT1, VT2. A high-performance athlete (HPA was used for comparison with three groups of subjects with different sport-specific performance levels. Load profiles of COMP were also investigated during uphill, flat and downhill cycling. During the COMP, athletes achieved a mean oxygen uptake (VO2COMP of 57.0 ± 6.8 ml·kg-1·min-1 vs. 71.1 ml·kg-1·min-1 for the HPA. The POCOMP was 2.66±0.43 W·kg-1 and 3.52 W·kg-1 for the HPA. POCOMP, VO2COMP and HRCOMP were compared to corresponding variables at the VT2 of LabT. LabT variables correlated with racing time (RTCOMP and POCOMP (p < 0.01 to <0.001; r-0.59 to -0.80. The VO2peak (LabT accounted for 65% of variance of a single COMP test. VO2COMP, POCOMP and also endurance variables measured from LabTs were found as important determinants for cross-country performance. The high average VO2COMP indicates that a high aerobic capacity is a prerequisite for successful COMP. Findings derived from respiratory gas measures during COMPs might be useful when designing mountain bike specific training.

  12. GC-FID/MS Profiling of Supercritical CO2 Extracts of Peels from Citrus aurantium, C. sinensis cv. Washington navel, C. sinensis cv. Tarocco and C. sinensis cv. Doppio Sanguigno from Dubrovnik Area (Croatia).

    Science.gov (United States)

    Jerković, Igor; Drulžić, Jasmina; Marijanović, Zvonimir; Gugić, Mirko; Jokić, Stela; Roje, Marin

    2015-07-01

    The peels of Citrus aurantium L. and Citrus sinensis Osbeck cultivars from the Dubrovnik region (south Croatia) were extracted by supercritical CO2 at 40 degrees C and 10 MPa at 1.76 kg/h to obtain enriched extracts in comparison with simple pressing of the peels. The extracts were analyzed in detail by gas chromatography and mass spectrometry (GC-FID/MS). Relevant similarities among the peel oil compositions of C. aurantium and C. sinensis cultivars were found with limonene predominance (up to 54.3%). The principal oxygenated monoterpenes were linalool (3.0%-5.9%), α-terpineol (0.7%-2.4%), linalyl acetate (0.0%-5.0%), geranyl acetate (0.0%-0.4%), (Z)-citral (0.0%-1.8%) and (E)-citral (0.0%-1.9%). Several sesquiterpenes were found with minor percentages. Coumarin derivatives were identified in all the samples among the relevant compounds. Isogeijerin dominated in the peels of C. sinensis cv. Tarocco (15.3%) and C. aurantium (11.2%). Scoparone ranged from 0.1% to 0.5% in all the samples. Bergapten (up to 1.4%), osthole (up to 1.1%) and 7-methoxy-8-(2-formylpropyl)coumarin (up to 1.1%) were found mostly in C. sinensis cv. Doppio Sanguigno. It was possible to indicate a few other differences among the extracts such as higher percentage of linalool, linalyl and geranyl acetates, as well as the abundance of sabinene and isogeijerin in C. aurantium or the occurrence of β-sinensal in C. sinensis cultivars.

  13. Response surface methodology as an approach to optimization of ethereal Oil from cassia by supercritical CO2 extraction%CO2超临界萃取桂皮精油工艺条件的优化

    Institute of Scientific and Technical Information of China (English)

    刘成国; 王冬冬; 陈瑶; 罗扬

    2011-01-01

    Cassia was used as raw material to extract ethereal oil using supercritical CO2 extraction.Scavenging effect of DPPH · (2,2-Diphenyl-l-Picryhydrazyl)was used as antioxidant activity index, based on single factor experiments, the optimal extraction process was determined using central composite design combined with response surface methodology.Optimal conditions of supereritical CO2 extraction of ethereal oil from cassia can be concluded as follows: Extraction pressure 33.5 MPa, extraction time 1.7 h, extraction temperature 60.5 ℃.On these conditions, the observed and predicted values of the scavenging effect of DPPH · were 84.98% and 85.17%.%以桂皮为原料,利用CO超临界萃取法提取桂皮精油.在单因素试验的基础上,以二苯代苦味酰基自由基清除率(2,2-Diphenyl-1-Picryhydrazyl,DPPH·)为抗氧化性指标,利用Box-Benhnken中心组合试验和响应面分析法,确定提取桂皮精油的最适工艺条件:萃取压力33.5 MPa,萃取时间1.7 h,萃取温度60.5℃.该条件下测得桂皮精油的DPPH·清除率为84.98%,预测值为85.17%.

  14. Screening of Six Medicinal Plant Extracts Obtained by Two Conventional Methods and Supercritical CO2 Extraction Targeted on Coumarin Content, 2,2-Diphenyl-1-picrylhydrazyl Radical Scavenging Capacity and Total Phenols Content

    Directory of Open Access Journals (Sweden)

    Maja Molnar

    2017-02-01

    Full Text Available Six medicinal plants Helichrysum italicum (Roth G. Don, Angelica archangelica L., Lavandula officinalis L., Salvia officinalis L., Melilotus officinalis L., and Ruta graveolens L. were used. The aim of the study was to compare their extracts obtained by Soxhlet (hexane extraction, maceration with ethanol (EtOH, and supercritical CO2 extraction (SC-CO2 targeted on coumarin content (by high performance liquid chromatography with ultraviolet detection, HPLC-UV, 2,2-diphenyl-1-picrylhydrazyl radical (DPPH scavenging capacity, and total phenols (TPs content (by Folin–Ciocalteu assay. The highest extraction yields were obtained by EtOH, followed by hexane and SC-CO2. The highest coumarin content (316.37 mg/100 g was found in M. officinalis EtOH extracts, but its SC-CO2 extraction yield was very low for further investigation. Coumarin was also found in SC-CO2 extracts of S. officinalis, R. graveolens, A. archangelica, and L. officinalis. EtOH extracts of all plants exhibited the highest DPPH scavenging capacity. SC-CO2 extracts exhibited antiradical capacity similar to hexane extracts, while S. officinalis SC-CO2 extracts were the most potent (95.7%. EtOH extracts contained the most TPs (up to 132.1 mg gallic acid equivalents (GAE/g from H. italicum in comparison to hexane or SC-CO2 extracts. TPs content was highly correlated to the DPPH scavenging capacity of the extracts. The results indicate that for comprehensive screening of different medicinal plants, various extraction techniques should be used in order to get a better insight into their components content or antiradical capacity.

  15. Study on Optimization of Process for Extracting Ginger Oil by Supercritical CO2 Extraction Technology%超临界CO2萃取姜油树脂的工艺研究

    Institute of Scientific and Technical Information of China (English)

    张建立; 李公春

    2011-01-01

    [目的]优化采用超临界CO_2萃取取姜油树脂的工艺.[方法]利用超临界CO_2流体作为萃取溶剂从干姜中提取姜油树脂,研究萃取压力、萃取时间和萃取温度对姜油树脂萃取率的影响,通过正交试验确定了姜油树脂萃取工艺的最佳萃取条件.[结果]姜油树脂超临界CO_2萃取的最佳萃取工艺条件为:萃取压力35MPa,萃取时间2.5h,萃取温度40℃,在此条件下,姜油树脂的萃取率为2.86%.[结论]该研究可为调味料科研工作者和生产厂家提供参考.%[ Objective] The research aimed to optimize the process of extracting ginger oil by supercritical CO2 extraction technology. [ Method] The ginger oil was extracted from dry ginger by supercritical CO, fluid, and the effects of extraction pressure, extraction time and extraction temperature on extraction rate of ginger oil were studied. The optimum extraction condition of ginger oil was determined through orthogonal test. [Result] The optimum extraction process of ginger oil was extraction pressure of 35 Mpa, extraction time of 2.5 h, extraction temperature of 40 ℃. Under this condition, the extraction rate of ginger oil was 2.86%. [ Conclusion] The study can provide reference for scientists researching flavoring and manufacturers.

  16. Supercritical CO2 fluid extraction of terpenoids in platycladus orientalis leaves%超临界CO2流体萃取侧柏叶萜烯化合物方法的讨论

    Institute of Scientific and Technical Information of China (English)

    王骏; 吴京科

    2011-01-01

    Adding entrainer in supercritical CO2 fluid will increase the extraction quantity and extracted types of terpenoids in platycladus orientalis leaves. In this paper, terpenoids α-pinene and (β-caryophyllene in platy-cladus orientalis leaves were extracted through controlling the single factor and by using ethanol and ethyl acetate as entrainers, and were detected by GC and GC/MS. The results showed that using an extraction vessel with a volume of 10mL, the optimal extraction rate for a-pinene and β-caryophyllene was achieved when 2mL ethanol was used as entrainer and the fresh platycladus orientalis leaves was 1. 5g, with the extraction temperature of 38℃ and the extraction pressure of 30 Mpa.%在改变温度和压力条件下尤其是添加夹带剂后,超临界CO2流体可进一步增加侧柏叶萜烯类化合物的萃取量和化合物种类.本文通过控制单因子变化,选取无水乙醇和乙酸乙酯为夹带剂,对侧柏叶中萜烯类化合物α-蒎烯、β-石竹烯进行萃取和GC、GC/MS检测.研究结果表明,应用体积10mL的萃取釜,在鲜侧柏叶1.5g,萃取温度为38℃、压力为30MPa时,2mL无水乙醇对侧柏叶α-蒎烯、β-石竹烯的提取率较好.

  17. 芫荽子超临界CO2萃取及其成分分析%Extraction of Coriander Seed by Supercritical CO2 Fluidand Analysis of the Extract

    Institute of Scientific and Technical Information of China (English)

    李列; 熊国玺; 喻世涛; 王娜; 张辉; 朱巍

    2014-01-01

    Orthogonal experimental design was used to optimize the process of extraction of coriander seed by supercritical CO2 fluid. The optimal conditions obtained were as follows:extraction pressure 26 MPa and temperature 50 ℃ for 60 min,the volume dosage of absolute ethyl alcohol as entrainer 10% ,the separate temperature 40℃ and pressure 5 MPa,under which the extraction rate was 23 .78% . The components of extract were analyzed by GC-MS,and 27 kinds of component were identified, which amounted to 89.02% of total extract,the main components wereα-terpinyl acetate,ethyl oleate,caryophyllene oxide, etc. The method is simple,rapid,and the extract obtained was in paste form with pure odor.%采用正交试验法优化芫荽子的萃取工艺条件,确定了超临界 CO2萃取芫荽子的最佳条件:萃取压力26 MPa,萃取温度50℃,选择无水乙醇为夹带剂,夹带剂用量(体积比)为10%,萃取时间为60 min,解析压力为5 MPa,解析温度为40℃,获得萃取率为23.78%。利用GC-MS法对提取物成分进行分析,共检测出α-乙酸松油酯、油酸乙酯、石竹烯氧化物等25种主要化合物,总质量比约为89.02%。与传统提取方法相比,该法简便、快速,得到的膏状萃取物香气纯正。

  18. 超临界CO2从含铀氧化物粉末中直接萃取铀方法研究%Study on Direct Extraction of Uranium from Uranium Oxides Powder Using Supercritical CO2

    Institute of Scientific and Technical Information of China (English)

    李佳; 朱常桂; 刘小龙; 任萌; 刘锦洪

    2013-01-01

    采用超临界CO2/硝酸-磷酸三丁酯(SC-CO2/HNO3-TBP)为萃取体系,研究各影响因素对其直接从含铀氧化物粉末中萃取铀的影响规律.结果表明:HNO3/TBP比值增大,铀萃取效率(EU)明显增大,比值为1.4时有利于萃取;比值一定时,随有机相总体积增加EU呈线性增加;萃取反应大致分为3个阶段:体系趋于稳定时的较慢阶段,稳定状态下的快速萃取阶段以及受粉末状态影响的缓慢阶段;随温度升高,EU在60℃时达到最大值91.4%;随萃取体系压力增大,EU在12 MPa时达到萃取峰值94.7%;萃取产物分离采用二级减压分离方式,在1#分离器8 MPa、2#分离器5 MPa条件下,能对萃取产物实现很好地分离.%The factors with effects on direct extraction of uranium from uranium oxides powder is studied using supercritical CO2/TBP-HNO3 extraction system.The results show that the extraction efficiency of uranium (EU) is increasing obviously with an increased HNO3/TBP,and EU is the best at the ratio value of 1.4;Under certain HNO3/TBP,EU is direct proportional to the volume of organic phase.The extraction reaction can be divided into three phases:react slowly in initial phase,fast in stable phase and slowly in final phase due to powder condition; As temperature increasing,EU has maximum value 91.4% at 60℃; As pressure increasing,EU has maximum value 94.7% at 12 MPa; According to extraction equipment condition,the best separation of extraction products can be achieved in 8 MPa (separation vessel 1) and 5 MPa (separation vessel 2).

  19. 超临界CO2对铝塑复合材料废弃物的剥离效果%Separation of Aluminum-Plastics Composite Material Waste Through Supercritical CO2

    Institute of Scientific and Technical Information of China (English)

    巩波; 雷华

    2013-01-01

    Aluminum-plastics composite material has a multilay er structure composed of aluminum foil and plastics,of which the recycling should be based on the separation of aluminum foil and plastics.In order to avoid the shortcoming of the existing methods which easily led to secondary pollution,a new technology called “popcorn” separation method to separate aluminum foil and plastics was proposed,which takes advantage of the characteristics of supercritical CO2 that rapidly penetrate in plastics layer,swell the plastics but without any effect on aluminum foil,and cause rapid expansion of the volume of the plastics after fast discharging.Through the research of the effects of a variety of operating factors on separation degree,the optimum separation conditions were obtained with a pressure of 25MPa,a temperature of 60 ℃,a balance time of 3 h and a rapid discharging process that the pressure drops more than 50 % in 30 seconds.This method is an efficient and environmentally friendly separation technology.%铝塑复合材料是铝箔和塑料组成的多层结构材料,其回收利用必须剥离开铝箔和塑料.针对现有方法易带来二次污染的缺点,文中利用超临界CO2流体在塑料层渗透速度快、能溶胀聚合物而对铝箔不产生作用以及快速卸压引发聚合物的体积快速膨胀特点,提出了“爆米花”式剥离铝塑复合材料废弃物的新技术.通过研究对分离度产生影响的各种操作因素,获得了最优化的剥离工艺条件:压力25MPa,温度60℃,平衡时间3h,快速卸压满足在30s内压力下降50%以上.该方法是一种高效环保的分离技术.

  20. 超临界CO2萃取辣根精油及其在酱油中的应用%Supercritical CO2 Extraction of Horseradish Essential Oil and Its Application in Soy Sauce

    Institute of Scientific and Technical Information of China (English)

    毛文颖; 刘丽; 张燕燕; 姚婉莹; 李书斌; 马文娟; 赵晓; 孙波

    2012-01-01

    Horseradish essential oil was extracted by supercritical CO2.The effects of extraction pressure,extraction temperature and extraction time on extraction rate of essential oil were investigated.The optimal extraction conditions were optimized by orthogonal tests.The minimal inhibitory concentration(MIC) of horseradish essential oil and its application in soy sauce was determined.The results showed that the optimal extraction process parameters were extraction pressure of 25 MPa,extraction temperature of 40 ℃ and extraction time of 90 min.Under the optimal extraction process,the extraction rate of horseradish essential oil was up to 0.91%.The MIC of horseradish essential oil against Escherichia coli and Bacillus subtilis were 0.04μL/mL.Compared with 1.0 g/kg sodium benzoate,0.04μL/mL horseradish essential oil or 0.02μL/mL horseradish essential oil coupled with 0.5 g/kg sodium benzoate could remain good quality of soy sauce after 30 days storage at 37 ℃.The simultaneous application of both antioxidants is better than their single applications.%采用超临界CO2萃取辣根精油,研究萃取压力、萃取温度和萃取时间对得率的影响,并利用正交试验优化最适的萃取条件,将萃取的辣根精油进行最小抑菌浓度(minimal inhibitory concentration,MIC)和酱油中应用的实验。结果表明:当萃取压力25MPa、萃取温度40℃、萃取时间90min时,辣根精油得率为0.91%;辣根精油对大肠杆菌和枯草芽孢杆菌的MIC均为0.04μL/mL;与添加1.0g/kg苯甲酸钠相比,单独添加0.04μL/mL辣根精油或同时添加0.02μL/mL辣根精油和0.5g/kg苯甲酸钠,均使酱油在37℃条件下保藏30d品质良好,其中同时添加两种物质的应用性更好。

  1. Evaluation of in vitro anti-inflammatory effects of crude ginger and rosemary extracts obtained through supercritical CO2 extraction on macrophage and tumor cell line: the influence of vehicle type.

    Science.gov (United States)

    Justo, Oselys Rodriguez; Simioni, Patricia Ucelli; Gabriel, Dirce Lima; Tamashiro, Wirla Maria da Silva Cunha; Rosa, Paulo de Tarso Vieira; Moraes, Ângela Maria

    2015-10-29

    Numerous plants from have been investigated due to their anti-inflammatory activity and, among then, extracts or components of ginger (Zingiber officinale Roscoe) and rosemary (Rosmarinus officinalis L.), sources of polyphenolic compounds. 6-gingerol from ginger rhizome and carnosic acid and carnosol from rosemary leaves present anti-tumor, anti-inflammatory and antioxidant activities. However, the evaluation of the mechanisms of action of these and other plant extracts is limited due to their high hydrophobicity. Dimethylsulfoxide (DMSO) is commonly used as a vehicle of liposoluble materials to mammalian cells in vitro, presenting enhanced cell penetration. Liposomes are also able to efficiently deliver agents to mammalian cells, being capable to incorporate in their structure not only hydrophobic molecules, but also hydrophilic and amphiphilic compounds. Another strategy is based on the use of Pluronic F-68, a biocompatible low-foaming, non-ionic surfactant, to disperse hydrophobic components. Here, these three delivery approaches were compared to analyze their influence on the in vitro anti-inflammatory effects of ginger and rosemary extracts, at different concentrations, on primary mammalian cells and on a tumor cell line. Ginger and rosemary extracts free of organic solvents were obtained by supercritical fluid extraction and dispersed in DMSO, Pluronic F-68 or liposomes, in variable concentrations. Cell viability, production of inflammatory mediators and nitric oxide (NO) release were measured in vitro on J774 cell line and murine macrophages primary culture stimulated with bacterial lipopolysaccharide and interferon-γ after being exposed or not to these extracts. Ginger and rosemary extracts obtained by supercritical CO2 extraction inhibited the production of pro-inflammatory cytokines and the release of NO by peritoneal macrophages and J774 cells. The delivery vehicles influenced the anti-inflammatory effects. Comparatively, the ginger extract showed the

  2. Corrosion Behaviour of 13Cr in Supercritical CO2 Environment%超临界CO2环境13Cr材质腐蚀行为研究

    Institute of Scientific and Technical Information of China (English)

    邢希金; 谢仁军; 马岩; 刘书杰

    2016-01-01

    ABSTRACT:Objective The Dongfang gas field in western South China Sea is under high temperature and high pressure condition, with gas reservoir temperature of 141℃, CO2 content of 50%, and CO2 partial pressure of 27.9 MPa, and the CO2 in downhole is under supercritical state. The suitable downhole anticorrosion material for this gas field was chosen by the simula-tion of underground environment corrosion experiment.Methods In this paper, HTHP FCZ magnetic driving reactor was used to simulate the composition and content of underground water ions, and 13Cr steel materials produced by China or Japan were chosen for anticorrosion experiment under supercritical CO2condition in Dongfang gas field. The chemical composition and microstructure of the metal materials in two different regions were compared.Results The experimental results showed that pit- ting did not occurr on the 13Cr martensitic stainless steel in either liquid phase or gas phase. The uniform corrosion rate was lower than 0.0013 mm/a. Meanwhile, the corrosion products were uniform and the structure of them was compact.Conclusion Simulated corrosion experiments in Dongfang gas field showed that the corrosion resistance of 13Cr steel in two different re-gions was similar. Considering the influence of gas flow velocity and sand production in high pressure gas wells, the application condition of 13Cr martensitic stainless steel in supercritical CO2 gas wells was discussed. To reduce the damage to corrosion product film, the flow rate in practical and decrease erosion in tubing should be reduced.%目的:我国南海西部东方气田高温高压,气层温度高达141℃,CO2体积分数高达50%,CO2分压值高达27.9 MPa,井下CO2处于超临界状态,通过模拟井下环境腐蚀实验为该气田选择合适的井下防腐材质。方法室内模拟地层水离子组成与含量,利用高温高压 FCZ 磁力驱动反应釜,选取中国产和日本原产的13Cr钢在东方气田超临界CO2

  3. Optimization for Supercritical CO2 Extraction with Response Surface Methodology and Component Analysis of Sapindus mukorossi Oil%响应曲面法优化无患子油超临界CO2萃取工艺研究及其成分分析

    Institute of Scientific and Technical Information of China (English)

    吴燕; 肖新玉; 葛发欢

    2012-01-01

    目的:研究无患子油超临界CO2萃取工艺及其成分分析.方法:以无患子为材料,采用响应曲面法优化无患子油超临界CO2萃取工艺,并采用GC-MS对无患子油成分进行分析.结果:建立了一个能较好预测萃取结果的数学模型,并根据该方程对无患子油的超临界萃取工艺参数进行了优选.确定了无患子油超临界CO2萃取最佳工艺为:萃取压力30 MPa,萃取温度40℃,分离I压力14 MPa、温度45℃,分离Ⅱ压力6MPa、温度40℃,萃取时间60 min,得率为17.58%;并对无患子油进行了GC-MS分析,鉴定了22种成分,其中不饱和脂肪酸含量为86.59%.结论:优化后的工艺合理可行,操作简单,可用于无患子油的提取.%Objective:To study the extraction conditions of Sapindus mukorossi oil by Supercritical CO2 Extraction and identify its components. Methods: Optimized SFE-CO, Extraction by Response Surface Methodology and used GC-MS to analysis Sapindus mukorossi oil compounds. Results: Established the model of an equation for the extraction rate of Sapindus mukorossi oil by Supercritical CO2 Extraction, and the optimal parameters for the Supercritical CO2 Extraction determined by the equation were:the extraction pressure was 30 MPa, temperature was 40 ℃; The separation I pressure was 14 MPa. temperature was 45℃ ; The separation Ⅱ pressure was 6 MPa, temperature was 40℃ ; The extraction time was 60 min and the extraction rate of Sapindus mukorossi oil of 17.58%. 22 main compounds of Sapindus mukorossi oil extracted by supercritical CO2 were identified by GC-MS, unsaturated fatty acids were 86. 59%. Conclusion·This process is reliable, safe and with simple operation, and can be used for the extraction of Sapindus mukorossi oil.

  4. 超临界CO2法制备褪黑素脂质体的工艺优化%Technology optimization of melatonin liposome using supercritical CO2

    Institute of Scientific and Technical Information of China (English)

    赵少杰; 叶盛英; 欧春凤; 郑森鸿

    2014-01-01

    .2% with the supercritical time of 35 min, the supercritical temperature of 50℃, ethanol concentration of 7.5%. Preparing melatonin liposome using supercritical CO2 method was able to be controlled in laboratory. This method is encouraged for promotion in industrial production due to its high entrapment rate, small particle and great stability.%为了优化褪黑素脂质体的生产工艺、提高包封率以及褪黑素的生物利用度,采用响应面法优化超临界CO2制备褪黑素脂质体的工艺参数。在单因素试验基础上以共溶剂浓度、超临界时间、超临界压力为影响因素,脂质体的包埋率为响应值,运用分析法建立了二次多项式数学模型,并分析模型的有效性及各因素间的交互作用。最终响应面法优化的工艺参数为:乙醇浓度为7.5%,超临界温度为50℃,超临界时间为35 min,此时包埋率可高达83.2%。采用超临界二氧化碳法制备褪黑素脂质体具有工艺简单、重现性好,且脂质体包封率高、颗粒粒径小、稳定性较高等优点,为今后的实际生产提供了理论基础和科学依据。

  5. Anticonvulsant Effects of Supercritical-CO2 Alcohol Fluid Extractions of Rhizoma Pinelliae%天南星超临界CO2乙醇萃取物抗惊厥作用的实验研究

    Institute of Scientific and Technical Information of China (English)

    杨蓉; 王明正; 成银霞

    2013-01-01

    Objective To investigate the antagonize action of supercritical - CO2 alcohol fluid extraction of rhizoma pmelhae(SFE -CO2 RP) on different convulsive model and explore its mechanism of anticonvulsant action. Method Maximal electroshock seizure (MES) and Metrazol seizure test (MET) were used to analyze the anticonvulsant effects in mice treated by SFE-CO2 RP. The model of seizure rats induced by penicillin injected in cortex was used to investigate effect of SFE - CO2 RP on the convulsant behaviors and hippocampus EEG. Result SFE - CO2 RP was dose - dependently antagonize MES, and could prolong latent period (P<0.01) on MET in mice,and could also prolong the latent period on the penicillin -induced seizure and lighten the extent of seizure. At the same time,it could prolong latent period of epileptiform discharge,reduce the frequency of epileptiform discharge,and decrease the highest wave of hippocampus EEG. All above indexes were significantly difference between model group and control groups(P<0.05 or P< 0.01). Conclusion SFE -CO2 RP was dose -dependently antagonize MES and antagonize MET in mice,it also could antagonize penicillin-kindling seizure in rats. Anticonvulsant properties of SFE - CO2 RP was resemble as TPM.%目的 研究中草药天南星超临界CO2乙醇萃取物对不同惊厥动物模型的对抗作用,并探讨其作用机制.方法 采用最大电休克(MES)和戊四唑惊厥模型(MET),以托吡酯(TPM)为阳性对照,观察其抗惊厥作用;建立大鼠皮层定位注射青霉素点燃模型,观察其灌胃给药对惊厥行为和脑电图的影响.结果 天南星超临界CO2萃取物对MES模型有对抗作用,且量效呈正相关性.可延长MET惊厥潜伏期(P<0.01),对抗MET发作.对青霉素点燃模型亦产生对抗作用,可延长痫性发作潜伏期、减轻发作程度,延长痫性放电的潜伏期,减少痫波发放频率,减小放电最高波幅,与模型组比较,差异有统计学意义(P<0.05或P<0.01).结论

  6. Anticonvulsive action of Pinellia Pedatisecta Schott extract prepared by ethanol-modified supercritical CO2 extraction%掌叶半夏超临界CO2乙醇萃取物的抗惊厥作用

    Institute of Scientific and Technical Information of China (English)

    陈靖京; 杨蓉; 王明正; 成银霞; 何新嘏; 马勇刚; 杨李华; 何巧燕

    2007-01-01

    AIM To investigate the anticonvulsive action of supercritical CO2 ethanol extract from Pinellia Pedatisecta Schott(SEE-CO2PP). METHODS The rat convulsive model was induced by penicillin localized injected in rat cortex. The effects of SEE-CO2PP on the latency of seizure and changes of convulsive behaviors were investigated. The latency of epileptiform discharge, and frequency and amplitude of highest wave in cortex and hippocampus were recorded by using RM6240C multichannel physiological signal collection and analysis recorder. At the same time, the contents of glutamic acid (Glu), aspartic acid (Asp), glycine (Gly) and γ-aminobutyric acid (GABA) in hippocampus were determined with high performance liquid chromatography. RESULTS SEE-CO2PP 15 and 30 g·kg-1, ig, prolonged the latent period of seizure and weakened the extent. SEE-CO2PP also prolonged the latent period of epileptiform discharge, reduced the frequency and decreased amplitude of the highest wave in both cortex and hippocampus. Moreover, SEE-CO2PP increased the content of GABA in hippocampus, but the levels of Gly,Asp and Glu had no obvious changes. CONCLUSION SEE-CO2PP inhibits the epileptiform discharge and convulsive behaviors of convulsive model rats, which suggests SEE-CO2PP has anticonvulsive action.%目的 研究掌叶半夏超临界CO2乙醇萃取物(SEE-CO2PP)对青霉素诱发惊厥的对抗作用.方法 采用大鼠皮质局部定位注射青霉素诱发惊厥模型,研究SEE-CO2PP对惊厥发作的潜伏期以及惊厥行为变化的影响,并用RM6240C型多道生理信号采集处理仪记录皮质和海马痫性放电的潜伏期、频率和痫波最高发放波幅,同时应用高效液相色谱法测定海马谷氨酸(Glu)、天冬氨酸 (Asp)、甘氨酸(Gly)和γ-氨基丁酸(GABA)递质的含量.结果 SEE-CO2PP 15和30 g·kg-1 (ig)可延长青霉素诱发惊厥的潜伏期,并减弱发作强度.SEE-CO2PP能够延长痫性放电的潜伏期,减少痫性放电的频率,减小皮质

  7. GC-MS Analysis of the Essential Oil from Ultrafine-Powder of Ganoderma sinense by Supercritical CO2 Fluid Extraction%超临界流体萃取紫芝挥发油成分的GC-MS分析

    Institute of Scientific and Technical Information of China (English)

    吴建国; 王宏雨; 吴岩斌; 陈体强

    2012-01-01

    Objective: Further to analysis chemical components in the essential oil (EO) of Ganoderma sinense. Methods: EO was extracted using Supercritical CO2 fluid extraction (SFE-CO2 ) technique from the ultrafine-powder of Ganoderma sinense, and detected by Gas chromatography-mass spectrometry (GC-MS) . Results: 46 compounds were checked out from the EO extract (with 1.47% of extract rate, ω/ω), and 26 compounds (matching degree >83%) were identified representing 79. 2% of the total EO, including n-Hexadecanoic acid, (E)-9-Octadecenoic acid methyl ester, (E)-9- Octadecenoic acid and (E,E)-2,4- Decadienal, 9-Methyl-Z-10-tetradecen-1-ol acetate, 1, 8, 8-trimethyl-2-( 3-oxocyclo- pentenyl )-Tricyclo [3.2.1.0 (2, 4)] octane-3, 3-dicarbonitrile, (Z)-9-Octadecenoic acid-2-hydroxy-l- (hydroxymethyl) ethyl ester and E-11-Hexadecen-l-ol and so on. Collusion: The results indicated that chemical components and their relative contents of the EO extracted by SFE-CO2 were different from that by steam distillation(SD) after ether refluxing.%为进一步研究紫芝挥发油的化学成分,采用超临界CO2流体萃取法从紫芝超细粉中提取分离挥发油,气相色谱-质谱联用分析其化学成分.从挥发油萃取物(1.47%,w/w)中检出46个峰(组分),鉴定了其中26个化合物(匹配度>83%),总相对含量占79.2%,主要成分有十六(烷)酸(18.88%)、(E)-十八碳-9-烯酸甲脂(18.74%)、(Z)-9-十八碳烯酸(24.33%)、(E)-2-癸烯醛(0.77%)、(E,E)-葵二烯醛(1.53%)、1,8,8-三甲基-2-(3-氧代环戊基)-三环[3.2.1.0(2,4)]辛烷-3,3-二腈(4.41%)、9-甲基-Z-1-十四碳-1-醇乙脂(1.20%)、(Z)-9-十八碳烯酸-2-羟基-1-羟甲基乙脂(1.95%)和E-11-十六烯-1-醇(2.38%)等.超临界流体萃取分离的紫芝挥发油成分及其相对含量有别于乙醚回流-水蒸气蒸馏法提取得到的挥发油成分.

  8. Biocompósitos de acetato de celulose e fibras curtas de Curauá tratadas com CO2 supercrítico Biocomposites based on cellulose acetate and short Curaua fibers treated with supercritical CO2

    Directory of Open Access Journals (Sweden)

    Miguel C. Gutiérrez

    2012-01-01

    Full Text Available Neste trabalho foram desenvolvidos biocompósitos baseados em acetato de celulose e fibras curtas de Curauá tratadas com dióxido de carbono supercrítico. O tratamento das fibras resultou na extração parcial de lignina, sendo este um método interessante pois não resulta em rejeitos químicos. Duas séries de biocompósitos, uma delas plastificada com ftalato de dioctila (DOP e outra com citrato de trietila (TEC, foram preparadas por extrusão. Para ambas ocorreu a fibrilação e distribuição uniforme das fibrilas. Como conseqüência, os biocompósitos apresentaram maior capacidade calorífica, menor condutividade térmica e maior coeficiente de expansão térmica em comparação ao acetato de celulose plastificado. O tratamento das fibras com CO2 supercrítico intensificou as variações destas propriedades. Dentre os plastificantes, o DOP mostrou-se ligeiramente mais eficiente, resultando em materiais com menores valores de Tg e de módulo de Young. A adição das fibras teve um impacto relativamente baixo sobre o módulo (10%, porém houve uma perda significativa da resistência ao impacto. O conjunto de resultados permite concluir que estes biocompósitos apresentam potencial de aplicação como isolantes térmicos, sendo que os plastificados com TEC apresentam como vantagem o fato de todos seus componentes serem biodegradáveis.In this work, the effect of pre-processing of short Curaua fibers with supercritical carbon dioxide on the properties of biocomposites with cellulose acetate was studied. The treatment with supercritical CO2 may result in the partial lignin extraction from the fibers. Two series of biocomposites, one plasticized with dioctyl phtalate (DOP and another with triethyl citrate (TEC, were prepared by extrusion. Fibrilation and uniform distribution of fibers in the cellulose acetate matrix were observed for both biocomposites. As a consequence, the composites showed a higher specific heat, lower thermal conductivity

  9. Microcelluar Foaming of Polypropylene/Nano-TiO2 Blends Using Supercritical CO2%聚丙烯/纳米二氧化钛复合材料的超临界流体微孔发泡

    Institute of Scientific and Technical Information of China (English)

    李彩凤; 应三九; 肖正刚

    2012-01-01

    以聚丙烯(PP)/nano-TiO2复合材料为研究对象,采用快速降压超临界微孔发泡技术,制备了泡孔密度、泡孔直径分别为2.8×107cell/cm3~3.15×109cell/cm3,46.36μm~6.08μm的PP/nano-TiO2微孔复合材料。研究了复合材料中nano-TiO2的质量分数、饱和压力及发泡温度对PP/nano-TiO2复合材料发泡行为的影响,通过扫描电镜(SEM)对微孔形貌进行表征。结果表明,加入nano-TiO2可以改善PP的发泡性能,并得到泡孔分布均匀的闭孔发泡材料;随复合材料中nano-TiO2质量分数由1%提高到5%,泡孔密度增加,泡孔直径减小。对于nano-TiO2质量分数为3%的PP/nano-TiO2复合材料,随着饱和压力的增加,泡孔直径和泡孔密度都增加;随着发泡温度的升高,泡孔密度减小,泡孔直径变大。%This research presents the foaming behaviors of polypropylene/nano-TiO2 nanocomposites which blown with supercritical CO2 during rapid pressure reduction process. Microcellular nanocomposities with 2.8×10^7 cm-3 to 3.15×10^9 cm-3 cell density and 46.36 μm to 6.08 μm cell diameter were prepared. Through studying the effects of nano-TiO2 quality score, saturation pressure, foaming temperature on the foaming behavior of PP/nano-TiO2 composite materials, the cell structures are characterized by Scanning electronic microscopy (SEM). The experimental results indicated that the addition of nano-TiO2 can significantly improving the foaming behaviors of PP, foaming materials with can be cell distribution more evenly of closed pore obtained. With the nano-TiO2 content increasing, the cell diameter reduced and the cell density increased, in addition, the cell distribution was more uniform. For the PP/nano-TiO2 composite materials with 3% nano-TiO2, when the saturation pressure increased, both the cell diameter and cell density increased. The cell diameter increased and the cell density decreased with the elevated temperature.

  10. 半夏等7种中药超临界CO2萃取物抗惊厥作用比较%Comparison Study of Supercritical-CO2 Fluid Extractions of Pinellia Rhizoma on Anticonvulsant Action

    Institute of Scientific and Technical Information of China (English)

    杨蓉; 王明正; 成银霞

    2012-01-01

    Objective: To compare the anticonvulsion effect of supercritical-CO2 fluid extractions (SFE-CO2) of Bupleuri Radix , and explore their mechanism. Method: One thousand and sixty mice were randomly divided into 11 groups; RB Ⅰ group, RB Ⅱ group, RAT Ⅰ group, RAT Ⅱ group, AR Ⅱ group, UN Ⅱ group, PR Ⅱ group, SCL Ⅰ group, PS Ⅰ group, topamax group and NS group. Every group was divided into 4-6 dose groups. The maximal electroshock seizure ( MES) was used to observe the anticonvulsion effect. ED50 dose against MES was considered as the administrated dosage to observe the anticonvulsant affects in metrazol seizure test ( MET). The rat seizure model was reduced by cortex localion injection of penicillin to investigate the effect of extractions on the convulsant behaviors and hippocampus EEG (the doses were converted by ED95 of MES). Result: ①Except for RB Ⅱ and PS Ⅰ , all the other seven extractions (PR Ⅱ , UN Ⅱ , RAT Ⅰ , PR Ⅱ , SCL Ⅰ , RB Ⅰ , RAT Ⅱ ) could dose-dependently antagonize MES in mice. ②All of the seven extractions could prolong the latent period of MET in mice, and the sequence from maximum to minimum was RP Ⅱ , UN Ⅱ , RAT Ⅰ , PR Ⅱ , SCL Ⅰ , RB Ⅰ , RATⅡ . The effect of RP Ⅱ (11. 06 ±4. 32) min was better than topamax (9. 57 ± 4. 47) min. ③ The extractions with SFE-CO2 showed a faster onset and shorter duration of he anticonvulsant action than that of supercritical-CO2 alcohol fluid extractions (SAFE-CO2). ④PR Ⅱ , AR Ⅱ , UN Ⅱ , RAT Ⅰ , RAT Ⅱ and RB Ⅰ could prolong the latent period of epileptiform discharge, reduce the frequency of epileptiform discharge, and decrease the highest wave of hippocampus EEG. Conclusion: AR Ⅱ , UN Ⅱ , RAT Ⅰ , PTⅡ , SCL Ⅰ , RB Ⅰ , RATⅡ could dose-dependently antagonize MES and MET in mice; PR Ⅱ , ARⅡ , UN Ⅱ , RAT Ⅰ and RB Ⅰ could antagonize penicillin-kindling seizure in rats. PT Ⅱ may be the most effective extraction in antagonizing

  11. NASA's Robotics Mining Competition Provides Undergraduates Full Life Cycle Systems Engineering Experience

    Science.gov (United States)

    Stecklein, Jonette

    2017-01-01

    NASA has held an annual robotic mining competition for teams of university/college students since 2010. This competition is yearlong, suitable for a senior university engineering capstone project. It encompasses the full project life cycle from ideation of a robot design to actual tele-operation of the robot in simulated Mars conditions mining and collecting simulated regolith. A major required element for this competition is a Systems Engineering Paper in which each team describes the systems engineering approaches used on their project. The score for the Systems Engineering Paper contributes 25% towards the team's score for the competition's grand prize. The required use of systems engineering on the project by this competition introduces the students to an intense practical application of systems engineering throughout a full project life cycle.

  12. NASA's Robotic Mining Competition Provides Undergraduates Full Life Cycle Systems Engineering Experience

    Science.gov (United States)

    Stecklein, Jonette

    2017-01-01

    NASA has held an annual robotic mining competition for teams of university/college students since 2010. This competition is yearlong, suitable for a senior university engineering capstone project. It encompasses the full project life cycle from ideation of a robot design, through tele-operation of the robot collecting regolith in simulated Mars conditions, to disposal of the robot systems after the competition. A major required element for this competition is a Systems Engineering Paper in which each team describes the systems engineering approaches used on their project. The score for the Systems Engineering Paper contributes 25% towards the team’s score for the competition’s grand prize. The required use of systems engineering on the project by this competition introduces the students to an intense practical application of systems engineering throughout a full project life cycle.

  13. Effects of intraspecific competition on the life cycle of the stonefly, Nemurella pictetii (Plecoptera: Nemouridae

    Directory of Open Access Journals (Sweden)

    Zwick Peter

    2008-04-01

    Full Text Available Abstract Background Considerable variation of life cycle duration in given insect species has been frequently recorded. Splitting of populations into cohorts with different life cycle lengths may occur, sometimes even between siblings from the same batch. Larval populations of the stonefly Nemurella pictetii in central Europe regularly split into a very fast developing and a normal univoltine cohort, leading to partial multivoltinism. The causes for such variation remain unknown but presumably act on the larval stage in which most of the life cycle is spent. We therefore studied possible effects of intraspecific competition on growth and development of larvae in the laboratory. Results Intraspecific competition had important influence on growth and development of the larvae. High larval densities led to reduced growth and retarded development through interference, not through exploitative competition. All specimens were negatively affected by frequent encounters and the resulting disturbance. There were no dominant individuals able to grow and develop faster than the rest, at the expense of the others. Conclusion Differences in life cycle length of Nemurella pictetii may result from different larval densities in different microhabitats and resultant different degrees of interference competition. Although competition alone probably does not cause splitting of populations into cohorts with different life cycle duration differences in size and development caused by other factors are certainly enhanced by intraspecific competition.

  14. Effect of temperature and cycle length on microbial competition in PHB-producing sequencing batch reactor

    NARCIS (Netherlands)

    Jiang, Y.; Marang, L.; Kleerebezem, R.; Muyzer, G.; van Loosdrecht, M.C.M.

    2011-01-01

    The impact of temperature and cycle length on microbial competition between polyhydroxybutyrate (PHB)-producing populations enriched in feast-famine sequencing batch reactors (SBRs) was investigated at temperatures of 20 °C and 30 °C, and in a cycle length range of 1-18 h. In this study, the microbi

  15. Researching the Competitiveness Factors of High-Tech Enterprises in the Dynamics of Life Cycle Stages

    Directory of Open Access Journals (Sweden)

    Kyriy Valentyna V.

    2017-06-01

    Full Text Available The article is aimed at studying the competitiveness factors that have the greatest impact on the IT industry enterprises, as well as determining the interrelationship between these factors and the life-cycle model of enterprise. Competitiveness factors were divided into general and sectoral according to the effect on enterprise. The sectoral factors were divided into groups by the attribute of the sphere of influence on enterprise: organizational, managerial, personal, market and factors of scientific-technical progress. The interrelationship between the competitiveness factors and the life cycle stages of an enterprise in the Greiner model has been determined. Attention is also paid to the specific weight of the factor groups at each stage, the indicators relevant to the factors by which the competitive position of the enterprise can be evaluated have been provided.

  16. Demands of World Cup Competitions in Elite Women Road Cycling.

    Science.gov (United States)

    Menaspà, Paolo; Sias, Marco; Bates, Gene; La Torre, Antonio

    2017-03-02

    Describing the demand of recent World Cup (WC) races comparing Top 10 (T10) and non-Top 10 (N-T10) performances using power data. Race data were collected in 1-day World Cup races during the 2012-2015 road cycling seasons. Seven female cyclists completed 49 WC races, finishing 25 times in T10 and 24 times N-T10. Peak power (1 s) and Maximal Mean Power (MMP) for durations of 5, 10, 20 and 30 s and 1, 2, 5, 10, 20, 30 and 60 min expressed as power to weight ratio were analysed in T10 and N-T10. The percentage of total race time spent at different power bands was compared between T10 and N-T10 using 0.75 W˖kg(-1) power bands, ranging from 7.50 W˖kg(-1). The number of efforts in which the power output remained above 7.50 W˖kg(-1) for at least 10 seconds were recorded. MMP were significantly higher in T10 than in N-Top 10, with a large effect size for durations between 10 seconds and 5 minutes. N-T10 spent more time in the 3.01-3.75 W·kg(-1) power band when compared to T10 (P=0.011); conversely, T10 spent more time in the 6.75-7.50 and >7.50 W·kg(-1) power bands (P=0.009 and 0.005, respectively) than N-T10. A significantly higher number of short and high intensity efforts (≥10s, >7.5 W·kg(-1)) was ridden by T10, compared to N-T10 (P=0.002). Specifically, 46±20 and 30±15 efforts for T10 and N-T10, respectively. The ability to ride at high intensity was determinant for successful road cycling performances in WC races.

  17. Supercritical CO2 Extraction and Composition Analysis of Essential Oil from Kuerle Fragrant Pear*%超临界CO2萃取法提取库尔勒香梨精油及其成分分析研究

    Institute of Scientific and Technical Information of China (English)

    娄在祥; 柳杨; 王洪新

    2011-01-01

    The essential oil from kuerle fragrant pear is extracted by supercritical CO2 extraction method,steam distillation and the solid phase micro-extraction. The results show that compared to the yield of essential oil by supercritical CO2 extraction of essential oils was 0.0549% , which was higher than that of steam distillation and solid phase micro extraction. Sensory analysis results showed that the essential oil obtained by supercritical CO2 extraction was orange, transparent liquid oil, and taste good. 28 compounds were identified in the essential oil of kuerle fragrant pear. The compositions of the essential oil was then identified by gas chromatography-mass spectrometry (GC-MS) ,28 compounds had been characterized. The content of Ethyl butyrate was the highest, which was 5. 19%.%采用超临界CO2萃取法提取库尔勒香梨精油,用气相色谱-串联质谱技术对其成分进行分析,并对几种提取方法进行综合比较。结果表明,与水蒸气蒸馏法、固相微萃取法相比,超临界CO2萃取法具有香梨精油提取率最高,为0.0549%。感官分析的结果表明,超临界CO2萃取法所得的库尔勒香梨精油颜色为橙色透明液体,而且风味好。气相色谱-质谱联用(GC-MS)分析结果表明:超临界CO2萃取法所得的香梨精油中共鉴定出28种成分。丁酸乙酯、顺-7-十四烯-1-醇和乙酸己酯的含量最高,含量分别为5.19%、4.85%和4.37%。

  18. Activity cycles of National Rugby League and National Youth Competition matches.

    Science.gov (United States)

    Gabbett, Tim J

    2012-06-01

    Examination of ball-in-play periods (i.e., match activity cycles) is a method used to provide insight into the physical demands of team sport competition. However, to date, no study has investigated the ball-in-play time of rugby league matches. This study investigated the activity cycles (i.e., ball-in-play periods) of elite National Rugby League (NRL) and National Youth Competition (NYC) matches. Video recordings of 393 NRL matches and 388 NYC matches were coded for activity and recovery cycles. Time when the ball was continuously in play was considered activity, whereas any stoppages during the match (e.g., for scrums, penalties, line drop-outs, tries, and video referee decisions) were considered recovery. The total time the ball was in play for NRL and NYC matches was approximately 55 minutes and 50 minutes, respectively. In comparison with NYC matches, NRL matches had longer average activity cycles (81.2 ± 16.1 vs. 72.0 ± 14.7 seconds, effect size [ES] = 0.60). The average longest activity cycle was also higher (ES = 0.48) in NRL (318.3 ± 65.4 seconds) than in NYC (288.9 ± 57.5 seconds) matches. The longest activity cycle from any match was 667 and 701 seconds for NRL and NYC matches, respectively. The NRL matches had a smaller proportion of short duration (91-600 seconds) activity cycles. In conclusion, meaningful differences in activity cycles were observed between NRL and NYC matches, with NRL competition demonstrating longer ball-in-play periods, a smaller proportion of short duration activity cycles, and a larger proportion of longer duration activity cycles. These findings suggest that the ability to perform prolonged high-intensity exercise, coupled with the capacity to recover during brief stoppages in play, is a critical requirement of professional rugby league match play.

  19. Modeling of the competition life cycle using the software complex of cellular automata PyCAlab

    Science.gov (United States)

    Berg, D. B.; Beklemishev, K. A.; Medvedev, A. N.; Medvedeva, M. A.

    2015-11-01

    The aim of the work is to develop a numerical model of the life cycle of competition on the basis of software complex cellular automata PyCAlab. The model is based on the general patterns of growth of various systems in resource-limited settings. At examples it is shown that the period of transition from an unlimited growth of the market agents to the stage of competitive growth takes quite a long time and may be characterized as monotonic. During this period two main strategies of competitive selection coexist: 1) capture of maximum market space with any reasonable costs; 2) saving by reducing costs. The obtained results allow concluding that the competitive strategies of companies must combine two mentioned types of behavior, and this issue needs to be given adequate attention in the academic literature on management. The created numerical model may be used for market research when developing of the strategies for promotion of new goods and services.

  20. Protective Effects of Supercritical CO2 Extracts of Armeniacae Semen Amarum on Human Fibroblast Damaged by Ultraviolet A%杏仁超临界CO2萃取物抗 UVA 对成纤维细胞的损伤作用

    Institute of Scientific and Technical Information of China (English)

    陈巧云; 王业秋; 张宁; 任燕冬; 井丽巍

    2012-01-01

    目的 探讨杏仁超临界CO2萃取物对UVA诱导的人皮肤成纤维细胞(ESF-1)损伤的保护作用及其作用机制.方法 用20J.cm-2的UVA照射ESF-1细胞建立光老化细胞模型,以不同浓度杏仁超临界CO2萃取物处理光老化细胞,MTT法检测细胞活力,羟胺法检测细胞SOD活性,比色法检测GSH-Px活性,TBA法检测MDA含量,酶联免疫法检测TNF-α、IL-1β分泌量.结果 UVA照射ESF-1细胞后,细胞活力、SOD、GSH-Px活性降低,MDA含量升高,TNF-α、IL-1β分泌量增加(P<0.01),40 μg·mL-1和80 μg·mL-1杏仁超临界CO2萃取物能显著提高成纤维细胞活力、SOD、GSH-Px活性,降低MDA含量,减少TNF-α、IL-1β分泌(P<0.05或P<0.01).结论 杏仁超临界CO2萃取物能减轻UVA对人皮肤成纤维细胞的损伤,其机制可能与其清除氧自由基,抗脂质过氧化,抑制氧化损伤,减少炎症细胞因子分泌有关.%OBJECTIVE To observe the protective of supercritical CO2 extracts of Armeniacae Semen Amarum on human fibroblasts iniured by irradiation of ultraviolet A and explore its possible mechanism. METHODS The model of photoaging fibroblasts was established by irradiating of ultraviolet light(20 J·cm-2). The different concentration of supercritical CO2 extracts of Armeniacae Semen Amarum were used for photoaging cell. The cell viability,SOD activity,GSH-Px activity,MDA content were assayed by MTT,hydroxylamine,colorimetric and TBA methods,respectively. The secretion levels of TNF-α and IL-1β of cultured ESF-1 cells were detected by ELISA. RESULTS After the UVA irradiation,the cell viability,the activities of SOD and GSH-Px were decreased,the content of MDA,TNF-α,and IL-lβ were increased(P<0.01) by 40 μg·mL-1 and 80 μg·mL-1 supercritical CO2 extracts of Armeniacae Semen Amarum. CONCLUSION The supercritical CO2 extracts of Armeniacae Semen Amarum might inhibit the proliferation decreasing which induced by UVA. And its mechanism may have relationship with the ability of

  1. 响应面法优化超临界CO2萃取丁香酚的工艺研究%Optimization of supercritical CO2 extraction of eugenol from clove (Eugenia caryophyllata Thunb) bud by response surface methodology

    Institute of Scientific and Technical Information of China (English)

    谢莹莹; 王志祥; 史益强; 丁朝中

    2013-01-01

    Objective To optimize the supercritical CO2 extraction process of cugcnol from colve(Eugenia caryophyllata Thunb). Method On the basis of single factors, using extraction rate as reference, extraction conditions of cugcnol from clove (Eugenia car yo phyllala Thunb) bud with supercritical CO2 extraction was optimized with response surface analysis. Results The optimum extraction conditions were as follows: power 25 Mpa, temperature 55 ℃ , time 1 h, volume fraction of alcohol 90%, and flow of modifier 0.04 mL · min-1 ,particle size 100 mesh. Under these conditions cugenol extraction rate could reach to 17. 41 %. Conclusion The optimized process conditions arc stable and practicable in manufacture.%目的 优选丁香中丁香酚的超临界CO2萃取工艺.方法 以丁香酚得率为考察指标,在单因素实验的基础上,采用响应面法对超临界CO2萃取丁香酚的工艺条件进行优化.结果 得到优选萃取条件为:萃取压力25 MPa,萃取温度55 ℃,萃取时间1 h,夹带剂体积分数90%乙醇,夹带剂流量0.04 mL·min-1,原料粒径100目,在此条件下丁香酚得率可达到17.41%.结论 优选的萃取工艺稳定、可行.

  2. 超临界CO2萃取牛蒡片挥发油及气相色谱-质谱联用分析%GC-MS analysis of volatile oil from slices of Arctium Lappa L.by supercritical CO2 extraction

    Institute of Scientific and Technical Information of China (English)

    窦德宇; 刘炎; 柳春燕; 杨丽芬; 陈靠山

    2012-01-01

    Objective :To verify the feasibility of obtaining the volatile oil from slices of Arctium Lappa L. By supercritical carbon dioxide (C02 ) extraction and determine the chemical components of the extract. Methods: The volatile oil was obtained by supercritical CO2 and the chemical components were isolated and identified by gas chromatography-mass spec-trometry(GC-MS). Results-. The extraction rate was 0. 84 % , and 31 compounds were identified from 41 extraction peaks. Conclusion; The technology is competent for extracting the volatile oil from slices of Arctium Lappa L. By supercritical CO2 , and the oil was identified as a mixture of multiple chemical components.%目的:探讨超临界CO2萃取牛蒡片挥发油的可行性并检测其化学成分.方法:采用超临界CO2萃取得到牛蒡片挥发油,并用气相色谱-质谱联用(GC-MS)对其化学成分进行分析.结果:挥发油的萃取率为0.84%,从挥发油中分离出41个峰,鉴定出其中31种化合物.结论:超临界CO2萃取可作为一种有效提取牛蒡片挥发油的方法,其挥发油为多种类型化合物的混合物.

  3. Competition

    NARCIS (Netherlands)

    Boone, J.

    2000-01-01

    Competition has been modelled in the literature in a number of ways.What do these different parametrizations of competition have in common?For instance, it turns out that it is not always the case that a rise in competition reduces price cost margins, industry wide profits or concentration.All param

  4. Competition.

    Science.gov (United States)

    Chambers, D W

    1997-01-01

    Our ambivalence toward competition can be traced to an unspoken preference for certain types of competition which give us an advantage over the types we value less. Four types are defined (a) pure (same rules, same objectives), (b) collaborative (same rules, shared objective), (c) market share (different rules, same objectives), and (d) market growth (different rules, value added orientation). The defining characteristics of the four types of competition are respectively: needing a referee, arguing over the spoils, differentiation and substitutability, and customer focus. Dentistry has features of all four types of competition, thus making it difficult to have a meaningful discussion or frame a coherent policy on this topic.

  5. 维药神香草挥发油与超临界 CO2流体萃取物化学成分的比较研究%The comparison of chemical constituents in the volatile oil and supercritical CO2 fluid extracts of Hyssopus officinalis L

    Institute of Scientific and Technical Information of China (English)

    祖丽菲亚·吾斯曼; 努尔江·肉孜; 买吾拉尼江·依孜布拉; 麦合苏木·艾克木

    2015-01-01

    目的:研究维药神香草水蒸气蒸馏提取挥发油与超临界 CO2流体萃取物化学成分的异同。方法采用水蒸气蒸馏法与超临界 CO2流体萃取法分别提取神香草挥发油和超临界 CO2流体萃取物,并通过气相色谱-质谱(GC-MS)联用仪对其化学成分进行分析和鉴定。结果维药神香草挥发油的水蒸气蒸馏法提取率为0.68%,GC-MS 分析、鉴定出所有65种化合物,其中含量较高的是亚油酸(13.83%)、棕榈酸(13.80%)、(+)-胡薄荷酮(8.31%)、(+)斯巴醇(6.27%)、二十一烷(5.34%)、香茅酸(4.07%)、二十六烷(4.02%)、二十四烷(3.28%)、二十烷(3.06%)。维药神香草超临界 CO2流体萃取物的萃取得率为5.5%,GC-MS 分析、鉴定出所有34种化合物,其中γ-谷甾醇(31.882%)、二十八烷(19.953%)、亚麻酸(16.279%)、三十六烷(15.939%)、棕榈酸(10.658%)、亚麻酸乙酯(12.471%)、三十一烷(12.215%)、9,12,15-十八烷三烯酸乙酯(9.057%)化合物含量较高。结论维药神香草挥发油与超临界 CO2流体萃取物化学组成存在较大的差异,超临界 CO2流体萃取物中的γ-谷甾醇、亚麻酸、亚麻酸乙酯等被认为是具有较强生物活性的化合物,且含量较高,具有较大的潜在研究前景。%Objective To study the similarity and differences in chemical composition and relative content of volatile oil by steam distillation and supercritical CO2 Fluid extraction extracts of Hyssopus officinalis L. (Hyssop),a Traditional Uighur Hreb Medicine.Methods Hyssopus volatile oil and SFE exctracts was extracted by steam distillation and supercritical CO2 Fluid extraction methods and the gas chromatography-mass spectrometry (GC-MS)were used to analyze its chemical composition.Then,relative content of each component has been calculated

  6. Competition

    NARCIS (Netherlands)

    F. Bridoux

    2014-01-01

    Competition traditionally refers to the actions that firms take in a product market to outperform rivals in attracting customers and generating revenues. Yet, competition extends beyond product markets to other arenas such as factor markets, where firms compete for resources, and the political arena

  7. 川芎水蒸气蒸馏和超临界CO2提取物化学成分的GC-MS分析鉴别%GC-MS Analysis and Determination of Chemical Components of the Extracts from Ligusticum Chuanxiong Hort.by Steam Distillation and Supercritical CO2 Extraction

    Institute of Scientific and Technical Information of China (English)

    曾志; 谢润乾; 谭丽贤; 张涛

    2011-01-01

    The chemical components of Ligusticum chuanxiong Hort. Were extracted by steam distillation and supercritical C02 extraction, and analyzed by combined capillary gas chromatography-mass spectrometry(GC-MS). Thirty and thirty four compounds were identified, respectively, and their relative contents were determined. This study revealed that the major components of L chuanxiong Hort. By steam distillation and supercritical CO2 extraction were (Z) -ligustilide. The chemical components from L chuanxiong Hort. Extracted by supercritical CO2 extraction possessed more bioactive substances such as butylphthalide, butylidene phthalide, senkyunolide A, (Z)-ligustilide, (E)-ligustilide and senkyunobde I. However, the components from L chuanxiong Hort. Extracted by steam distillation contained more terpenes except for the bioactive substances. Therefore, supercritical CO2 extraction has more productivity than steam distillation for the extraction of the bioactive substances from L chuanxiong Hort. Through the interpretation and summarization of the regular patterns of the lactones with unsaturated and saturated side chains from L. Chuanxiong Hort. , the structures of the lactones with unsaturated side chain such as (Z)-ligustilide, (E)-ligustilide, butylidene phthalide and senkyunolide I as well as the lactones with saturated side chain such as butylphthalide and senkyunolide A have been determined.%用水蒸气蒸馏和超临界CO2提取方法对川芎药材中的化学成分进行提取,用气相色谱-质谱联用技术(GC-MS)对提取物进行分析,分别鉴定出30和34个化合物,测定了其相对含量.结果表明,水蒸气蒸馏和超临界CO2提取物的主要成分均为(Z)-藁本内酯.超临界CO2提取方法能提取出较多的川芎药效物质,如丁基酞内酯、丁烯基酞内酯、川芎内酯A、(Z)-藁本内酯、(E)-藁本内酯和川芎内酯I.而水蒸气蒸馏提取物中除了川芎药效物质外,还含有较多的萜烯类化

  8. Chemical constituents of essential oil from a Tibetan herb-Bibilin (Piper longum L.) extracted by supercritical CO2 fluid extraction%藏药毕毕林二氧化碳超临界流体萃取精油化学成分研究

    Institute of Scientific and Technical Information of China (English)

    热增才旦; 刘斌; 董芳; 王英锋

    2011-01-01

    目的 研究习称为“三辛药”之一的藏药毕毕林精油化学成分及其相对含量.方法 采用超临界CO2流体萃取法提取毕毕林精油,采用气相色谱-质谱联用方法分离鉴定精油化学成分并测定其相对含量.结果 毕毕林超临界CO2流体萃取精油得率为9.7%,分离得到59个色谱峰,鉴定出52种成分,主要成分是胡椒碱(19.24%)、毕澄茄烯(l0.62%)、4-硝基苯酯邻甲氧基苯甲酸(6.47%)、1-(1-氧代-11,14-二十碳三烯基)-吡咯烷(4.75%)、14(E)-十六碳烯醛(4.38%)、十五烷(4.35%)和反亚油酸甲酯(4.28%)等.结论 二氧化碳超临界流体萃取精油是藏药毕毕林的药效组分之一,且是其辛味的主要物质基础.%Objective To study the chemical constituents and relevant content of essential oil from a Tibetan herb-Bibilin (Piper longum L. ) , which was usually considered as one of "three pungent herbs". Methods The essential oil from Bibilin was extracted by using supercritical CO2 fluid extraction, the chemical constituents were separated and identified and their relevant content was determined by using gas chromatography-mass spectrometry ( GC-MS). Results The yield of the essential oil was 9. 7%. There were 59 peaks separated and 52 constituents identified. The main constituents were piperylpiperidine (19.24% ), cubebene (10.62% ), 4-nitrophenyl o-anisic ester (6.47% ), l-( 1-oxo-11, 14-eicosadienyl)-pyrrolidine (4.75%), E-14-hexadecenal (4.38%), n-pentadecane (4.35%) and trans-methyl linolelaidate (4.28% ). ConclusionThe essential oil extracted by supercritical CO2 fluid extraction is one of effective components of Bibilin, which is the major material base of its pungent flavor.

  9. 用FeCl3作为反应剂超临界CO2浸取砂岩型铀矿中的铀%Supercritical CO2 fluid leaching of uranium from sandstone type ores using FeCl3 as reactant

    Institute of Scientific and Technical Information of China (English)

    王艳龙; 谭凯旋; 屈慧琼; 李春光; 胡杨; 李咏梅

    2014-01-01

    铀是重要的核能燃料,而超临界CO2是一种新型高效且环境安全性的铀提取方法。在FeCl3作为反应剂的前提下,考察了主要因素压力和时间对浸取效果的影响。恒定时间下随着压力的增加浸出率是先增加后减少,恒定压力下随着时间的增加浸出率是先增加然后是到稳定状态。最佳浸出条件为压力10MPa,浸出率可达90%。与传统的酸碱浸取铀相比,浸取效果要明显高于常规采铀。所以超临界 CO2流体浸取有望应用于低品位砂岩铀矿的地浸采铀中。%Uranium is an important nuclear fuel,and supercritical CO2 fluid leaching is a new,efficient and environmentally safe uranium extraction method. The aim of this experiment was to investigate the impact of pressure and time on uranium leaching efficiency with FeCl3 as reactant. Leaching efficiency first increased and then decreased with the increase of pressure. Under a constant specific pressure leaching efficiency first increased with increasiing time and then stabilized at a fixed value. The optimum leaching pressure was 10MPa,and leaching efficiency could reach 90%. Compared with the traditional acid-alkali leaching of uranium,leaching effect was significantly higher. Supercritical CO2 fluid leaching could be used for in-situ uranium leaching of low grade sandstone-type uranium deposits.

  10. 超临界CO2流体萃取-精馏联用技术提取脱酸月见草油的工艺优选%Optimization of Supercritical CO2 Fluid Extraction-Fractionation Technology for One Step Deacidification of Evening Primrose Oil

    Institute of Scientific and Technical Information of China (English)

    谷满仓; 钱亚芳

    2013-01-01

    Objective:To optimize extraction technology conditions of deacidification evening primrose oil by supercritical CO2 fluid extraction-fractionation technology (SCFEF).Method:With yield of oil and the content of γ-linolenic acid as indexes,single factor tests were adopted to investigate effect of extraction pressure,extraction temperature,separation pressure and separation temperature on extraction technology of evening primrose oil.And quality differences of evening primrose oil was compared,which were extracted by SCFEF and supercritical CO2 fluid extraction (SCFE).Result:Optimal extraction parameters were as follows:extraction pressure 22 MPa,extraction temperature 36 ℃,separation pressure 10-12 MPa,separation temperature 48 ℃,dosage of CO2 45 kg,oil yield 16.7%-18.1%,the acid values of 0.85-1.21 mg KOH · g-1,each physical and chemical indicators of evening primrose oil from SCFEF were better than that from SCFE.Conclusion:SCFEF successfully prepared deacidified evening primrose oil by integration of extraction,separation and purification processions into one step.%目的:优选超临界CO2流体萃取-精馏联用技术(SCFEF)提取脱酸月见草油的工艺条件.方法:以得油率和γ-亚麻酸含量为指标,采用单因素试验考察萃取压力、萃取温度、分离压力和分离温度对月见草油提取工艺的影响.比较SCFEF与超临界CO2流体萃取技术(SCFE)提取的月见草油质量差异.结果:优选的脱酸月见草油提取工艺参数为萃取压力22 MPa,萃取温度308 K,分离压力10~12 MPa,分离温度321 K,CO2用量45 kg,脱酸月见草油得率16.7%~18.1%,酸值0.85~1.21 mg KOH·g-1,所得脱酸月见草油各项理化指标均优于SCFE所得月见草油.结论:SCFEF通过将萃取、分离与纯化工序耦合,可做到一步提取脱酸月见草油.

  11. 超临界CO2萃取冷破碎苹果皮蜡质工艺优化及其成分分析%Optimization of extracting process of waxes from cold-break apple peel by supercritical CO2 and analysis of the composition

    Institute of Scientific and Technical Information of China (English)

    李卓; 郭玉蓉; 闫玉培

    2012-01-01

    The extraction condition of waxes from cold-break apple peel by supercritical CO_2 extraction technology was studied and the composition of apple waxes was analyzed by GC-MS.The optimum condition of supercritical CO_2 were as follows:extraction pressure 35MPa,extraction temperature 50℃,raw material particle size100 mesh,extraction time 1.5h.Under optimal conditions,the yield of apple waxes was 2.081%.36 compounds of apple waxes were detected.Main ingredients were hydrocarbons and esters which account for 41.44% and 37.41% respectively of all the detected compounds.Alcohols,fatty acids,ketones,β-sitosterol and friedelin were also detected.%以冷破碎苹果皮渣为原料,研究超临界CO2萃取苹果皮蜡质的工艺条件,并用气相色谱-质谱联用技术(GC-MS)分析苹果皮蜡质的化学组成。结果表明:超临界CO2萃取苹果皮蜡质的最佳工艺条件为:萃取压力35MPa,萃取温度50℃,萃取时间1.5h,原料粒度〉100目,该条件下萃取率为2.081%;用GC-MS检测到萃取物中36种化合物,其中主要成分是饱和烷烃和酯类,这两类物质的相对含量分别为41.44%和37.41%;其次,苹果皮蜡质还含有醇类、脂肪酸、酮类、β-谷甾醇、木栓酮等成分。

  12. 响应面设计优化超临界CO2法制备盐酸小檗碱脂质体的处方工艺%Response surface methodology optimization of formulation using supercritical CO2 to prepare berberine liposome

    Institute of Scientific and Technical Information of China (English)

    张志丽; 张少华; 张志云; 郭永学; 周丽莉

    2012-01-01

    目的 采用中心复合设计实验优化超临界CO2法制备盐酸小檗碱脂质体的处方工艺.方法 考察药脂质量比和磷脂质量浓度对盐酸小檗碱脂质体包封率的影响,采用中心复合设计实验对超临界制备盐酸小檗碱处方工艺进行优化,并利用响应曲面法进行优化分析.结果 最优的工艺条件为:药脂质量比为13.2∶60,磷脂质量浓度为30 g·L-1,理论包封率为73.30%,载药量为15.98%.在此条件下的实际包封率为(72.15±1.9)%,载药量为15.74%,接近理论预测值.结论 作者研究的超临界CO2法制备盐酸小檗碱脂质体,实现了包封率与载药量的最佳组合,且工艺简单,适合工业生产.%Objective To develop a procedure to prepare and characterize berberine liposome using supercritical CO2. Methods The investigation of drug to phospholipid ratio(m- m) and the concentration of soya phos-phatidyl choline(SPC)on berberine hydrochloride liposome entrapment efficiency influence were studied to get the range of critical factors and then optimized by central composite design experiment using response surface methodology (RSM) to get the maximum entrapment efficiency and drug loading. Results The optimal formulation was as follow;the ratio of the amount of drug to phospholipid was 13. 25:60,and the concentration of soya phosphatidyl choline ( SPC) was 30 g·L-1,15. 74% berberine was loaded on liposomes and the entrapment efficiency reached 72. 15%. Conclusions The preparation of berberine hydrochloride liposome by using supercritical CO2 technology is proved to be the optimal combination both for entrapment efficiency and drug loading. The procedure is simple and suitable for the industrial production.

  13. Competition

    Institute of Scientific and Technical Information of China (English)

    吕思思

    2007-01-01

    <正> The term competition reminds me of asoul-stirring fight between a mother monkeyand a crocodile,The crocodile caught her babywhen the baby was drinking water in a pool,Inthe end,the mother got her baby,but herbaby’s body only,She lost her child forever,just for a mouthful of water.Such is competition,cruel and merciless,But if we see the other side of the coin,we’ll

  14. Effect of temperature and cycle length on microbial competition in PHB-producing sequencing batch reactor.

    Science.gov (United States)

    Jiang, Yang; Marang, Leonie; Kleerebezem, Robbert; Muyzer, Gerard; van Loosdrecht, Mark C M

    2011-05-01

    The impact of temperature and cycle length on microbial competition between polyhydroxybutyrate (PHB)-producing populations enriched in feast-famine sequencing batch reactors (SBRs) was investigated at temperatures of 20 °C and 30 °C, and in a cycle length range of 1-18 h. In this study, the microbial community structure of the PHB-producing enrichments was found to be strongly dependent on temperature, but not on cycle length. Zoogloea and Plasticicumulans acidivorans dominated the SBRs operated at 20 °C and 30 °C, respectively. Both enrichments accumulated PHB more than 75% of cell dry weight. Short-term temperature change experiments revealed that P. acidivorans was more temperature sensitive as compared with Zoogloea. This is particularly true for the PHB degradation, resulting in incomplete PHB degradation in P. acidivorans at 20 °C. Incomplete PHB degradation limited biomass growth and allowed Zoogloea to outcompete P. acidivorans. The PHB content at the end of the feast phase correlated well with the cycle length at a constant solid retention time (SRT). These results suggest that to establish enrichment with the capacity to store a high fraction of PHB, the number of cycles per SRT should be minimized independent of the temperature.

  15. Monopolistic Competition, International Trade and Firm Heterogeneity - a Life Cycle Perspective

    DEFF Research Database (Denmark)

    Nielsen, Jørgen Ulff-Møller; Hansen, Jørgen Drud; Kvedaras, Virmantas

    This paper presents a dynamic international trade model based on monopolistic competition, where observed intra-industry differences at a given point in time reflect different stages of the firm's life cycle. New product varieties of still higher quality enter the market every period rendering old...... varieties obsolescent in a process of creative destruction. For given technology (variety) production costs decrease after an infant period due to learning. It is shown that several patterns of exports may arise depending primarily on the size of fixed trade costs. At a given point in time firms therefore...

  16. Healthy competition: A qualitative study investigating persuasive technologies and the gamification of cycling.

    Science.gov (United States)

    Barratt, Paul

    2016-10-28

    Changing socio-technical practices occurring within cycling are leading the pursuit, and its participants, to become ever more embedded into the networked digital world. GPS enabled mobile-technologies have introduced a new element of competition into recreational riding, whether on the road, competing over timed virtual segments, or online dissecting and comparing the data that has been logged and shared via dedicated ride-logging applications. In order to understand these technologies qualitative study using reflective diaries and semi-structured interviews has been conducted with experienced club cyclists who had fully experienced the effects of their arrival. These riders claim that the applications influence their route choice and motivate them to cycle more frequently, and at a greater intensity although the engagement changes over time. This paper explores how this increased motivation to exercise and compete is instigated, manifested and maintained in the everyday practices of cyclists, as well as the negative consequences of gamification.

  17. Design and Application of CO2 Compressor Used for Exhaust Gas Recovery in the Process of Supercritical CO2 Fluid Extraction%超临界CO2流体萃取流程中CO2尾气回收压缩机的设计及应用

    Institute of Scientific and Technical Information of China (English)

    王高平; 张和平

    2012-01-01

    某公司超临界CO2流体萃取流程中CO2尾气回收压缩机抽气时间比预期时间超出4倍以上,为解决这一问题,通过对超临界流体萃取流程和CO2的特性分析,提出了萃取流程中CO2尾气回收压缩机的设计方法及回收流程方案的选择,并对压缩机的使用与保养做了阐述.%The suction time for the CO2 compressor used for exhaust gas recovery in the process of supercritical CO2 fluid extraction is the four times above than expected time.In order to solve the problem,the design method for CO2 compressor used for exhaust gas recovery in the extraction process and the selection of recycling process scheme are pointed out based on the characteristic analysis of supercritical fluid extraction process and of CO2-And the use and maintenance of compressor are specified in this paper.

  18. Preliminary conceptual design of the secondary sodium circuit-eliminated JSFR (Japan Sodium Fast Reactor) adopting a supercritical CO2 turbine system, 1; Sodium/CO2 heat exchanger

    OpenAIRE

    木曽原 直之; 阪本 善彦; 小竹 庄司

    2014-01-01

    JAEA has performed a design study of an S-CO2 gas turbine system applied to the JSFR. In this study, the S-CO2 cycle turbine system was directly connected to the primary sodium system of the JSFR to eliminate the secondary sodium circuit, aiming for further economical improvement. The Na/CO2 heat exchanger is one of the key components, and this report describes its structure and the safety in case of CO2 leak. A Printed Circuit Heat Exchanger (PCHE) is employed to the heat exchanger. A SiC/Si...

  19. Three-dimensional kinematics of competitive and recreational cyclists across different workloads during cycling.

    Science.gov (United States)

    Bini, Rodrigo R; Dagnese, Frederico; Rocha, Emmanuel; Silveira, Mateus C; Carpes, Felipe P; Mota, Carlos B

    2016-08-01

    Although the link between sagittal plane motion and exercise intensity has been highlighted, no study assessed if different workloads lead to changes in three-dimensional cycling kinematics. This study compared three-dimensional joint and segment kinematics between competitive and recreational road cyclists across different workloads. Twenty-four road male cyclists (12 competitive and 12 recreational) underwent an incremental workload test to determine aerobic peak power output. In a following session, cyclists performed four trials at sub-maximal workloads (65, 75, 85 and 95% of their aerobic peak power output) at 90 rpm of pedalling cadence. Mean hip adduction, thigh rotation, shank rotation, pelvis inclination (latero-lateral and anterior-posterior), spine inclination and rotation were computed at the power section of the crank cycle (12 o'clock to 6 o'clock crank positions) using three-dimensional kinematics. Greater lateral spine inclination (p road to recreational cyclists. When conducting assessment of joint and segment motions, workload between 65 and 95% of individual cyclists' peak power output could be used.

  20. A pilot study: bovine colostrum supplementation and hormonal and autonomic responses to competitive cycling.

    Science.gov (United States)

    Shing, C M; Peake, J M; Suzuki, K; Jenkins, D G; Coombes, J S

    2013-10-01

    The aim of this pilot investigation was to examine the influence of bovine colostrum protein concentrate (CPC) supplementation on salivary hormones, salivary IgA and heart rate variability over consecutive days of competitive cycling. Ten highly-trained male road cyclists (mean±SEM; age=22.2±4.7 yr; mass=70.5±4.5 kg; VO2max=72.9±3.8 mL.kg-1.min-1) were randomly assigned to a control (N.=6, 10g whey protein concentrate/day) or bovine CPC group (N.=4, 10 g bovine CPC/day). Cyclists provided a baseline saliva sample before commencing eight weeks of supplementation, and competing in a five day cycle race. Cyclists provided saliva samples and measured heart rate variability (HRV) each day of the race. Saliva samples were analysed for cortisol, testosterone and IgA concentrations. Bovine CPC supplementation was associated with increased morning cortisol concentration on the first day of racing when compared to the control group (P=0.004) and significantly prevented a decrease in testosterone concentration over the race period (P≤0.05). Across the race period parasympathetic indices of HRV were elevated in the bovine CPC group and reduced in the control group (P≤0.05), while there were no significant differences in salivary IgA between groups. Bovine CPC supplementation maintained salivary testosterone concentration and modulated autonomic activity over consecutive days of competitive cycling. This pilot study provides justification to explore the effects of bovine CPC on recovery in endurance athletes further.

  1. Competition

    CERN Multimedia

    Staff Association

    2017-01-01

    Get ready for the Easter Egg Hunt! The Staff Association is organising a competition from 10 to 21 April 2017. There are several Go Sport gift vouchers to win, with a value of 50 € each. Try your luck! Count the number of different eggs that we have hidden on our website. Then indicate your answer in the online form. To participate, you just need to be a member of the Staff Association. Winners will be randomly drawn among the correct answers.

  2. Competition

    CERN Multimedia

    Staff Association

    2016-01-01

      The Staff Association is organising a competition from 13 to 21 December 2016. There are several Go Sport vouchers to win with a value of 50 € each. Try your luck! To participate, you just have to be a member of the Staff Association and take the online quiz: https://ap-vote.web.cern.ch/content/jeu-concours-de-noel. The winners will be drawn among the correct answers.

  3. Competition

    CERN Multimedia

    Staff Association

    2016-01-01

      The Staff Association is organising a competition from April 11 to 20. There are several Go Sport gift vouchers with a value of 50 € each to win. Try your luck! To participate, you just have to be a member of the Staff Association and take the online quiz: https://ap-vote.web.cern.ch/content/jeu-concours. The winners will be drawn among the correct answers.

  4. Seated versus standing cycling in competitive road cyclists: uphill climbing and maximal oxygen uptake.

    Science.gov (United States)

    Tanaka, H; Bassett, D R; Best, S K; Baker, K R

    1996-04-01

    Seven competitive road cyclists (M +/- SE = 23.7 +/- 1.5 yr, 70.5 +/- 1.7 kg) participated to determine the effects of cycling body position on physiological responses during uphill cycling and maximal oxygen uptake (VO2max). There was no significant difference in VO2max between seated and standing positions on a cycle ergometer (66.4 +/- 1.6 vs. 66.4 +/- 1.7 ml . kg-1 . min-1). When the subjects rode their own bicycle on a treadmill, oxygen uptake and heart rate were significantly (p < 0.05) higher during standing when subjects bicycled at 20.0 km . h-1 (4% grade), but no difference was observed when riding at 12.3 km . h-1 (10% grade). Leg RPE was significantly (p < 0.05) lower for standing position up a 10% grade. The results suggest that the standing position is less economical during moderate hill climbing, but during steep hill climbing, it results in a decreased sensation of effort in the legs.

  5. Process Optimization and Principal Component Analysis of Extracts from Chinese Torreya by Supercritical CO2 Technology%超临界 CO2萃取香榧假种皮提取物的工艺优化及其主要成分分析

    Institute of Scientific and Technical Information of China (English)

    于勇杰; 韩琴; 倪穗; 邬玉芬; 桑卫国

    2015-01-01

    采用响应面法优化了超临界 CO2流体萃取(SCE)香榧假种皮提取物的工艺,并采用气相色谱质谱联用仪(GC -MS)对其提取物成分进行了分析。在单因素试验的基础上,选取动态萃取时间、萃取温度、萃取压力作为变量,以香榧假种皮提取物得率为指标,采用 Box -Behnken 试验设计方法进行Í因素Í水平试验,根据回归方程的预测模型对结果进行响应面分析,确定超临界 CO2流体萃取香榧假种皮提取物的优化工艺为:粉碎度40目,静态萃取时间20 min,动态萃取时间2.5 h、萃取温度45℃、萃取压力34 MPa,在此条件下提取物平均提取率为(22.12±0.09)%。经过 GC -MS 检测分析,香榧假种皮提取物的主要成分为二萜类物质,其次为羧酸、酯类、倍半萜类和单萜类物质。%A response surface method (RSM)was used to optimize supercritical CO2 extraction (SCE)of the extracts from Chinese Torreya aril and the main components of aril extracts was analyzed by gas chromatograph -mass spectrometer (GC -MS).Based on the single factor experiments,the dynamic extraction time,extraction tempera-ture and extraction pressure were selected as variables.The extraction yield of Chinese Torreya aril was regarded as index and the three -factor and three -level experiment was conducted by Box -Behnke experiment design method. The optimization process of extracts of Chinese Torreya aril by supercritical CO2 extraction was particle size of 40 mush,extraction time of 20 min,dynamic time of 2.5 h,temperature of 45 ℃ and pressure of 34 MPa.The optimal yield (22.12 ±0.09%)was obtained at the operating conditions.The results of GC -MS analysis showed that the main complements of aril extracts were diterpenoids,fatty acid,followed by sesquiterpenoids and monoterpenoids.

  6. Optimization of supercritical CO2 extraction of astaxanthin from pacific white shrimp(Litopenaeus vannamei) using response surface methodology%超临界CO2萃取南美白对虾虾青素的工艺优化

    Institute of Scientific and Technical Information of China (English)

    杨霞; 张志胜; 郑乾魏; 祖铁红; 淑英

    2013-01-01

    In order to improve the extraction yield and content of astaxanthin, supercritical CO2 fluid extraction was used to extract astaxanthin from the head of Pacific White Shrimp, high performance liquid chromatography (HPLC) was adopted to determine the content of astaxanthin after saponification, the influence of extraction parameters on the extraction yield and astaxanthin content was determined by single factor test, then response surface method was employed to optimize technical parameters. The results showed that the influence of extraction parameters on the extraction yield of astaxanthin was not significant(p>0.05),but significant on the astaxanthin content (p<0.05). When the particle size of material was 40 mesh, moisture content was 9%, the theory optimum conditions for extraction astaxanthin with supercritical CO2 extraction were confirmed as follow:pressure 403.95 Pa, extraction temperature 39.95 , CO℃ 2 flow rate 1.16 L/min, under the conditions, the astaxanthin content was 796.3 mg/g. In application, the astaxanthin content in validation test was 789.61 mg/g when the extraction pressure was 400 Pa, the extraction temperature was 40 and the CO℃ 2 flow rate was 1.2 L/min. The results can provide a reference for extraction and purification of astaxanthin.%  为提高虾青素萃取物得率和虾青素纯度,采用超临界CO2萃取南美白对虾虾头废弃物中的虾青素,皂化后用高效液相色谱对虾青素含量进行测定。单因素试验确定萃取参数对虾青素萃取物得率和虾青素纯度的影响,然后进一步运用响应面法对萃取工艺参数进行优化。结果表明:超临界CO2萃取工艺参数对虾青素萃取物得率影响不显著(P>0.05),但对虾青素纯度影响显著(P<0.05);物料粒径40目,质量含水率9%时,响应面理论优化最佳萃取参数为萃取压力403.95 Pa,萃取温度39.95℃,CO2流量1.16 L/min,虾青素纯度为796.3mg/g。结合实际应用

  7. N2、CH4对超临界CO2管线温降的影响规律%Research on the Effect of N2 and CH4 for Temperature Drop of Supercritical CO2 Pipeline Transportation

    Institute of Scientific and Technical Information of China (English)

    李传宪; 杨惠宇; 杨飞; 杨爽; 刘帅帅

    2016-01-01

    The physical properties of supercritical CO2 are impacted by gas impurities, which affect the pipeline transportation. In order to study the influence of Nitrogen and Methane on the temperature drop along supercritical CO2 pipeline, physical properties of CO2 were simulated using HYSYS software. The temperature dropping model was estab-lished based on Sukhoi formula and the program to calculate temperature change along the pipeline was written using VB6. 0 software. The results show that PR equation is better than other equation in the simulation of physical property of CO2 containing impurities;When the Nitrogen and Methane are mixed,the density and viscosity of CO2 decrease appar-ently while the heat capacity and compressibility factor increase;In normal operation,the sta-ble temperature field is formed around the pipe which influences the temperature change along the pipe, the temperature decline of CO2 pipeline transportation accelerated when the Nitrogen and Methane are mixed.%气体杂质的存在会不同程度地对超临界状态下CO2的物理性质产生影响,进而影响管道的安全运行.为研究N 2、CH4对超临界CO2管道沿线温降的影响规律,利用HYSYS软件对含N 2、CH4的超临界CO2的物理性质进行模拟计算,在苏霍夫公式的基础上建立超临界CO2管线的温降模型,利用VB 6.0软件编写温降计算程序,采用循环迭代的方法计算管道沿线温度变化.研究表明,PR方程对含N 2、CH4的超临界CO2体系在物理性质模拟计算方面优于其他状态方程;N 2、CH4的存在使超临界CO2的密度、黏度减小,比热容、压缩因子增大;正常运行时,管道周围形成稳定的温度场,管内超临界CO2的沿线温度降低,N 2、CH4的混入会减小超临界CO2管道输送过程中的温度衰降.

  8. Extraction of carotenoids from calyx of Physalis alkekengi var.francheti by supercritical CO2%超临界CO2流体用于萃取酸浆宿萼中类胡萝卜素的研究

    Institute of Scientific and Technical Information of China (English)

    马晴; 黄震

    2011-01-01

    The supercritical CO2 extraction has been examined for carotenoids extraction from Physalis alkekengi var. francheti calyx. The influences of the extraction pressure, temperature, time and particle size on the extraction yield were investigated. By means of UV spectrometry analysis,the stability of the extracted carotenoids was also investigated under several different conditions. The results showed that the obtained carotenoids were thermostable but very sensitive to sun-shining light. They were also strongly affected by some metal ion such as Fe3+ ,Fe2+ and Al3+ ,relatively weakly influenced by Cu2+ ,Zn2+ and Ca2+ ,and nearly not affected by two earth ions of Na+ and K+.%采用超临界CO2流体从酸浆宿萼中提取类胡萝卜素,探讨了萃取压力、温度、时间和原料粒度等萃取参数对提取量的影响.还利用UV定量地考察了所提取类胡萝卜素的耐光照稳定性、耐热稳定性和抗金属离子稳定性.结果表明,这些提取物耐热稳定,但对光很敏感.与金属离子的相互作用结果显示,Fe3+、Fe2+和Al3+对类胡萝卜素提取物的影响很显著,Cu2+、Zn2+和Ca2+等金属离子的影响相对较小,而Na+和K+基本没有影响.

  9. Study on Optimization of Extraction Conditions of Catechin from Roasted Green Tea by Supercritical-CO2 Fluid Extraction%炒青绿茶儿茶素超临界CO2萃取工艺优化研究

    Institute of Scientific and Technical Information of China (English)

    毛世红; 邱涛涛

    2014-01-01

    The extraction conditions of catechin from roasted green tea by supercritical-CO 2 fluid extraction (SFE-CO2)were studied. Influences of extraction temperature, extraction pressure, materiel-liquid ratio, and extraction time on the content of catechin were investigated, and the effect of extraction conditions on the extraction rate of catechin from extracts was evaluated by single factor and orthogonal tests.Experimental results showed that the successive order of diferent effect factors on yield of catechin was extraction pressure>materiel-liquid ratio>extraction time>materiel granularity. The optimal extraction conditions of catechin from roasted green tea as follows:extraction temperature 50℃, extraction time 120 min, extraction pressure 25 MPa, 1∶2.5 of solid to liquid ratio was used as a modifier, and 0.65 mm of particle size. The maximum SFE-CO2 extracting rate of catechin 6.053 6%.%采用单因素试验和正交试验对炒青绿茶儿茶素超临界CO2萃取工艺进行探讨,确定萃取效果影响的程度从高到低依次为:萃取压力>夹带剂乙醇用量>萃取时间>萃取粒度,最佳萃取工艺为:底物与夹带剂(乙醇)之比为100 g/250 mL,萃取压力25 MPa,萃取温度50℃,粒度为60目,萃取120 min。按照该工艺茶叶中儿茶素粗提物的得率为6.0536%。

  10. Extractive fermentation of aroma with supercritical CO2

    Science.gov (United States)

    Fabre; Condoret; Marty

    1999-08-20

    This work deals with the feasibility of achieving an extractive fermentation of 2-phenylethyl alcohol, the rose aroma, coupling fermentation with Kluyveromyces marxianus and supercritical carbon dioxide (SCCO2) extraction. The extractive process is, in this case, of special interest due to the strong yeast inhibition by 2-phenylethyl alcohol. First results confirmed that direct SCCO2 extraction is not possible, due to a drastic CO2 effect on cell viability. It is therefore necessary to perform cell separation prior to the extraction. Aroma extraction conditions from a synthetic mixture were then optimized, a pressure of 200 bar and a temperature in the range 35-45 degrees C being chosen. Under these conditions, the distribution coefficient Kd is 2 times higher than during the extraction using a conventional organic solvent, n-hexane. Using a simple model of aroma partition between aqueous and SCCO2 phases, the parameters of a continuous extraction from a synthetic broth were defined. The two substrates, glucose and phenylalanine, are not extracted whatever the conditions. As predicted by the model, more than 90% of 2-phenylethyl alcohol can be extracted, while the extraction of ethanol, the second main product, can be easily tuned with respect to operating conditions, as a function of its influence on the fermentation. Finally, the feasibility of the aroma recovery using two depressurization steps at the outflow of the extraction vessel was demonstrated; 97% of the extracted aroma was recovered, and a mass purity of 91% was achieved. Copyright 1999 John Wiley & Sons, Inc.

  11. QENS FROM POLYMER AGGREGATES IN SUPERCRITICAL CO2. (R826115)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  12. Alteration of bentonite when contacted with supercritical CO2

    Science.gov (United States)

    Jinseok, K.; Jo, H. Y.; Yun, S. T.

    2014-12-01

    Deep saline formations overlaid by impermeable caprocks with a high sealing capacity are attractive CO2 storage reservoirs. Shales, which consist of mainly clay minerals, are potential caprocks for the CO2 storage reservoirs. The properties of clay minerals in shales may affect the sealing capacity of shales. In this study, changes in clay minerals' properties when contacted with supercritical (SC) CO2 at various conditions were investigated. Bentonite, whichis composed of primarily montmorillonite, was used as the clay material in this study. Batch reactor tests on wet bentonite samples in the presence of SC CO2 with or without aqueous phases were conducted at high pressure (12 MPa) and moderate temperature (50 oC) conditions for a week. Results show that the bentonite samples obtained from the tests with SC CO2 had less change in porosity than those obtained from the tests without SC CO2 (vacuum-drying) at a given reaction time, indicating that the bentonite samples dried in the presence of SC CO2 maintained their structure. These results suggest that CO2 molecules can diffuse into interlayer of montmorillonite, which is a primary mineral of bentonite, and form a single CO2 molecule layer or double CO2 molecule layers. The CO2 molecules can displace water molecules in the interlayer, resulting in maintaining the interlayer spacing when dehydration occurs. Noticeable changes in reacted bentonite samples obtained from the tests with an aqueous phase (NaCl, CaCl2, or sea water) are decreases in the fraction of plagioclase and pyrite and formation of carbonate minerals (i.e., calcite and dolomite) and halite. In addition, no significant exchanges of Na or Ca on the exchangeable complex of the montmorillonite in the presence of SC CO2 occurred, resulting in no significant changes in the swelling capacity of bentonite samples after reacting with SC CO2 in the presence of aqueous phases. These results might be attributed by the CO2 molecule layer, which prevents diffusion of ions into the interlayer.

  13. Phase behaviour of sterols and vitamins in supercritical CO2

    Directory of Open Access Journals (Sweden)

    Gerszt R.

    2000-01-01

    Full Text Available Extraction with supercritical solvents has been used in different areas, such as petroleum desasphaltation, descaffeination of coffee and tea and in the separation of other types of natural products. The supercritical solvent most frequently utilized in the extraction of natural products is carbon dioxide (CO2 due to its several advantages over other solvents such as low cost, atoxicity and volatility. The design, evaluation and optimization of a supercritical extraction that is based on phase equilibrium require phase equilibrium data. This type of data is very scarce for natural compounds like sterols and vitamins. These natural compounds are produced synthetically, but nowadays interest in their extraction from natural sources is increasing. Therefore, the objective of this work is to study the thermodynamic modelling equilibrium of systems containing vitamins A, D, E and K, using the predictive LCVM model. The sensitivity of critical properties in the calculation of the phase behavior was also studied. This study proved that the choice of a group contribution method to calculate thermodynamic properties is very important for obtaining good results in the phase equilibrium calculations.

  14. Supercritical CO2 Cleaning for Planetary Protection and Contamination Control

    Science.gov (United States)

    Lin, Ying; Zhong, Fang; Aveline, David; Anderson, Mark; Chung, Shirley; Mennella, Jerami; Schubert, Wayne

    2010-01-01

    We have designed and built a prototype Supercritical CO? Cleaning (SCC) system at JPL. The key features of the system are: 1) the parts inside a high-pressure vessel can be rotated at high speeds; 2) the same thermodynamic condition is maintained during First-In First-Out flushing to keep solvent power constant; and 3) the boil-off during decompression is induced in a separate vessel downstream. Our goal is to demonstrate SCC's ability to remove trace amounts of microbial and organic contaminants down to parts per billion levels from spacecraft material surfaces for future astrobiology missions. The initial cleaning test results showed that SCC can achieve cleanliness levels of 0.01 microgram/cm(sup 2) or less for hydrophobic contaminants such as dioctyl phthalate and silicone and it is less effective in the removal and inactivation of the hydrophilic bacterial spores as expected. However, with the use of a polar co-solvent, the efficacy may improve dramatically. The same results were obtained using liquid CO?. This opens up the possibility of using subcritical cleaning conditions, which may prove to be more compatible with certain spacecraft hardware.

  15. POLYMERIC NANOPARTICLES FROM SUPERCRITICAL CO2 MICROEMULSION POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Wei-jun Ye; Jason S. Keiper; Joseph M. DeSimone

    2006-01-01

    Herein, we reported the microemulsion polymerization in supercritical carbon dioxide. With the aid of an anionic phosphate fluorosurfactant (bis-[2-(F-hexyl)ethyl]phosphate sodium), water-soluble/CO2-insoluble acryloxyethyltrimethyl ammonium chloride monomer and N,N'-methylene-bisacrylamide cross-linker were solubilized into CO2 continuous phase via the formation of water-in-CO2 (w/c) microemulsion water pools. Initiated by a CO2-soluble initiator, 2,2'-azo-bisisobutyronitrile (AIBN), cross-linked poly(acryloxyethyltrimethyl ammonium chloride) particles were produced and stabilized in these w/c internal water pools. Nano-sized particles with sizes less than 20 nm in diameter and narrow particle size distributions were obtained.

  16. Water extractable arabinoxylan aerogels prepared by supercritical CO2 drying.

    Science.gov (United States)

    Marquez-Escalante, Jorge; Carvajal-Millan, Elizabeth; Miki-Yoshida, Mario; Alvarez-Contreras, Lorena; Toledo-Guillén, Alma Rosa; Lizardi-Mendoza, Jaime; Rascón-Chu, Agustín

    2013-05-14

    Water extractable arabinoxylan (WEAX) aerogels were prepared by extracting the solvent from the alcogels (WEAX hydrogels with an alcohol as the solvent) with carbon dioxide under supercritical conditions. WEAX aerogels were characterized using scanning electron microscopy and adsorption and desorption nitrogen isotherms. The micrographs indicate a heterogeneous porous network structure in WEAX aerogel. Adsorption/desorption nitrogen isotherms of this material were type IV, which confirm that this material possess a mesoporous structure. WEAX aerogels rehydration capability was evaluated and the water absorption mechanism was determined. The WEAX aerogels water absorption mechanism was non-Fickian (n = 0.54).

  17. Supercritical CO2 extraction of essential oils from Chamaecyparis obtusa.

    Science.gov (United States)

    Jin, Yinzhe; Han, Dandan; Tian, Minglei; Row, Kyung-Ho

    2010-03-01

    Supercritical carbon dioxide (SC-CO2) extraction and hydrodistillation (HD) were used to determine the essential oil composition of the trunks and leaves of Chamaecyparis obtusa. The optimal extraction conditions for the oil yield within the experimental range of variables examined were temperature 50 degrees C, pressure 12 MPa, carbon dioxide flow rate 40 mL/min and extraction time 90 min. The maximum measured extraction yield was 2.9%. Entrainer solvents, such as methanol in water, had no additional effect on the extraction of essential oils. The chemical composition of the essential oils was analyzed by GC-MS. The major components were alpha-terpinyl acetate (>10.9%), 1-muurolol (>13.2%) and elemol (>8.1%). Sesquiterpenoids formed the major class of compounds present.

  18. Extraction of oil from wheat germ by supercritical CO2.

    Science.gov (United States)

    Piras, Alessandra; Rosa, Antonella; Falconieri, Danilo; Porcedda, Silvia; Dessì, Maria A; Marongiu, Bruno

    2009-07-15

    This study examined the supercritical fluid extraction of wheat germ oil. The effects of pressure (200-300 bar at 40 degrees C) and extraction time on the oil quality/quantity were studied. A comparison was also made between the relative qualities of material obtained by SFE and by organic solvent extraction. The extracts were analyzed for alpha-tocopherol and polyunsaturated fatty acid content. The maximum wheat germ oil yield at about 9% was obtained with supercritical carbon dioxide extraction at 300 bar, while fatty acid and alpha-tocopherol composition of the extracts was not remarkable affected by either pressure or the extraction method.

  19. Water Extractable Arabinoxylan Aerogels Prepared by Supercritical CO2 Drying

    Directory of Open Access Journals (Sweden)

    Agustín Rascón-Chu

    2013-05-01

    Full Text Available Water extractable arabinoxylan (WEAX aerogels were prepared by extracting the solvent from the alcogels (WEAX hydrogels with an alcohol as the solvent with carbon dioxide under supercritical conditions. WEAX aerogels were characterized using scanning electron microscopy and adsorption and desorption nitrogen isotherms. The micrographs indicate a heterogeneous porous network structure in WEAX aerogel. Adsorption/desorption nitrogen isotherms of this material were type IV, which confirm that this material possess a mesoporous structure. WEAX aerogels rehydration capability was evaluated and the water absorption mechanism was determined. The WEAX aerogels water absorption mechanism was non-Fickian (n = 0.54.

  20. Energy Efficiency as a Factor of Engineering Product Competitiveness and its Formation on Product Economic Life Cycle Stages

    OpenAIRE

    Ivan V. Evstratov

    2011-01-01

    This article discusses the concept of energy efficiency of enterprises and engineering products. The author research how energy efficiency effect on engineering product competitiveness and how rate of enterprise and engineering product formation on stages of the economic product life cycle.

  1. Energy Efficiency as a Factor of Engineering Product Competitiveness and its Formation on Product Economic Life Cycle Stages

    Directory of Open Access Journals (Sweden)

    Ivan V. Evstratov

    2011-11-01

    Full Text Available This article discusses the concept of energy efficiency of enterprises and engineering products. The author research how energy efficiency effect on engineering product competitiveness and how rate of enterprise and engineering product formation on stages of the economic product life cycle.

  2. EGS rock reactions with Supercritical CO2 saturated with water and water saturated with Supercritical CO2

    Energy Technology Data Exchange (ETDEWEB)

    Earl D. Mattson; Travis L. McLing; William Smith; Carl Palmer

    2013-02-01

    EGS using CO2 as a working fluid will likely involve hydro-shearing low-permeability hot rock reservoirs with a water solution. After that process, the fractures will be flushed with CO2 that is maintained under supercritical conditions (> 70 bars). Much of the injected water in the main fracture will be flushed out with the initial CO2 injection; however side fractures, micro fractures, and the lower portion of the fracture will contain connate water that will interact with the rock and the injected CO2. Dissolution/precipitation reactions in the resulting scCO2/brine/rock systems have the potential to significantly alter reservoir permeability, so it is important to understand where these precipitates form and how are they related to the evolving ‘free’ connate water in the system. To examine dissolution / precipitation behavior in such systems over time, we have conducted non-stirred batch experiments in the laboratory with pure minerals, sandstone, and basalt coupons with brine solution spiked with MnCl2 and scCO2. The coupons are exposed to liquid water saturated with scCO2 and extend above the water surface allowing the upper portion of the coupons to be exposed to scCO2 saturated with water. The coupons were subsequently analyzed using SEM to determine the location of reactions in both in and out of the liquid water. Results of these will be summarized with regard to significance for EGS with CO2 as a working fluid.

  3. Thermoeconomic Analysis and Optimization of a New Combined Supercritical Carbon Dioxide Recompression Brayton/Kalina Cycle

    Directory of Open Access Journals (Sweden)

    S. Mohammad S. Mahmoudi

    2016-10-01

    Full Text Available A new combined supercritical CO2 recompression Brayton/Kalina cycle (SCRB/KC is proposed. In the proposed system, waste heat from a supercritical CO2 recompression Brayton cycle (SCRBC is recovered by a Kalina cycle (KC to generate additional electrical power. The performances of the two cycles are simulated and compared using mass, energy and exergy balances of the overall systems and their components. Using the SPECO (Specific Exergy Costing approach and employing selected cost balance equations for the components of each system, the total product unit costs of the cycles are obtained. Parametric studies are performed to investigate the effects on the SCRB/KC and SCRBC thermodynamic and thermoeconomic performances of key decision parameters. In addition, considering the exergy efficiency and total product unit cost as criteria, optimization is performed for the SCRBC and SCRB/KC using Engineering Equation Solver software. The results indicate that the maximum exergy efficiency of the SCRB/KC is higher than that of the SCRBC by up to 10%, and that the minimum total product unit cost of the SCRB/KC is lower than that of the SCRBC by up to 4.9%.

  4. 响应面法优化烟草花超临界二氧化碳萃取工艺及香气分析%Optimization of Supercritical CO2 Fluid Extraction of Flowers of Nicotiana tabacum by Response Surface Method and Analysis of Aroma Components

    Institute of Scientific and Technical Information of China (English)

    刘煜宇; 李仙; 念小魁; 普元柱; 郑琳

    2013-01-01

    Supercritical CO2 fluid extraction (SCFE) was optimized by response surface method (RSM) to study the utilization of flowers of Nicotiana tabacum in tobacco,spice and medicine,etc.Taking the extraction yield of flowers of Nicotiana tabacum as response value,the effects of technical conditions on the extraction yield were determined by designing experiments according to Box-Behnken Design (BBD).The volatile components in the extract were identified by GC/MS method.The results showed that:1) The optimal extraction conditions were:pressure 31.9 MPa,temperature 47.3 ℃,and time 108.5 mins.2) 28 components were identified,and their contents were determined with peak area normalization method,among them,the component with the highest content (43.81%) was 1,5,9-trimethyl-12-(1-methylethyl)-4,8,13-cyclotetradecatriene-1,3-diol.%为了研究烟草花在烟草、香料、医药等方面的应用,以响应面法对烟草花超临界CO2萃取工艺进行了优化.以烟草花萃取率为响应值,根据Box-Behnken Design(BBD)设计实验,确定各工艺条件对萃取率的影响;采用气相色谱-质谱法对萃取物挥发性成分进行分析鉴定.结果表明:①烟草花的最佳超临界CO2萃取条件为:萃取压力31.9 MPa,萃取温度47.3℃,萃取时间108.5 min.②烟草花超临界CO2提取物中共鉴定出28种化合物,其中,含量最高的是1,5,9-三甲基-12-(1-异丙基)-4,8,13-环十四碳三烯-1,3-二醇(43.81%).

  5. Extraction of Essential Oil from the Flower of Chionanthus retusus Lindl. et Paxton by Supercritical CO2 and Its Antibacterial Activities%流苏花精油的超临界CO2萃取及抗菌活性研究

    Institute of Scientific and Technical Information of China (English)

    刘普; 李小方; 高嘉屿; 尹卫平; 邓瑞雪

    2015-01-01

    Single factor experiment and orthogonal experiment design were used to study the influences of extraction conditions on the yield of essential oil from the flower of Chionanthus retusus Lindl. et Paxton by supercritical CO2 method. The components of the essential oil were analyzed by gas chromatography-mass spectrometry ( GC-MS ) . The in vitro antibacterial activity of the eessential oil was characterized. The optimum extraction parameters were established with the extraction pressure 25 MPa, extraction temperature 45 ℃,extraction time 2. 0 h,and the fluent of CO2 22 kg/h. The yield of essential oil was up to 0. 409%. Sixty compositions were separated. Among them,57 components were identified and respresented 96. 18% of the total detected constituents. The results of the antibacteria,i. e. , assay showed that the essential oil displayed good antibacterial activity against the tested bacterial,i. e. Staphyloccocus aureu,Staphyloccocus albus,Escherichia coli.%采用单因素和正交试验法讨论了超临界CO2流体法萃取流苏花精油的工艺条件,利用气相色谱-质谱( GC-MS)联用技术分析了精油的化学成分,并对精油的抑菌活性进行了评价. 结果表明采用超临界CO2流体技术萃取流苏花精油的最佳工艺条件是:100 g流苏花粉末在萃取压力25 MPa,萃取温度45 ℃,萃取时间2. 0 h,CO2流量22 kg/h,在最佳工艺条件下精油的得率为0. 409%. 从流苏花精油中共分离出60个峰,确定了其中的57种化合物,所鉴定成分占总馏出峰面积的96. 18%. 体外抑菌试验结果表明,流苏花精油对金黄色葡萄球菌、白葡萄球菌和大肠杆菌等菌株具有较好的抑制作用.

  6. Research on Supercritical CO2 Fluid Extraction of Piper nigrum L .and Its GC-MS Fingerprints%白胡椒挥发油的超临界CO2萃取及其GC-MS指纹图谱的建立

    Institute of Scientific and Technical Information of China (English)

    肜霖; 张敦铁; 夏秋冬; 朱巍; 赵同林; 吴昭; 谭烨; 邵兴伟; 黄龙

    2014-01-01

    In order to develop new natural cigarette flavors,Pipernigrum L.was extracted with supercritical CO2 .The ob-tained oil was analyzed by GC-MS,and its fingerprints was estabilished,the method was investigated by methodological ap-proach as well .The results showed that:①the optimum extraction conditions were extraction temperature 45 ℃ ,extraction pressure 35 MPa,extraction time 2 h,the appropriate particle size 0.3 mm;②66 components in the extract were identified by GC-MS,mainly including terpenes,alcohols,acids and esters;③12 common peaks with their retention time and peak area of the components appeared the chromatographic fingerprints of this oil;④ the fingerprints would be beneficial for the quality and stability control for piper oil obtained by suppercritical CO2 fluid extraction method.%为开发新的天然烟用香料,研究了超临界CO2萃取白胡椒挥发油的工艺,采用GC-MS法分析了白胡椒挥发油的成分,同时建立了挥发油GC-MS指纹图谱,并进行了方法学考察。结果表明:①超临界CO2萃取白胡椒挥发油的最佳工艺条件为萃取温度45℃、萃取压力35 MPa、萃取时间2 h,原料粉碎至粒径0.3 mm;②以GC-MS方法分析白胡椒挥发油共鉴定出66种成分,主要是萜烯类、醇类、酸类物质;③12个主要成分的出峰次序及其相对含量构成了超临界 CO2萃取白胡椒挥发油的特征指纹图谱;④利用所建立的指纹图谱,可以控制超临界CO2萃取白胡椒挥发油的质量及稳定性。

  7. Synthesis of Salicylic Acid from Phenol Catalyzed by K2CO3 in Supercritical CO2%碳酸钾催化苯酚在超临界CO2中合成水杨酸的实验研究

    Institute of Scientific and Technical Information of China (English)

    徐明仙; 胡斯翰; 丁春晓; 林春绵

    2011-01-01

    The process of direct synthesis of salicylic acid from phenol catalyzed by K2CO3 in supercritical CO2 was studied. CO2 could act not only as a reagent but also as a solvent in this process. The conventional two-step synthesizing process of organic phenolic acid by Kolbe Schmitt reaction was improved, and the salicylic acid was synthesized by only one step. The influences of temperature (from 160 to 220℃), pressure (from 4 to 14 MPa), reaction time, amount of catalyst used were investigated. The highest salicylic acid yield could reach 54%, by-product is p-hydroxybenzoic acid of a very small amount, and selectivity is higher than 99%. The obtained optimum conditions of the reaction are as following: reaction temperature 190℃, reaction pressure 8 MPa, reaction time 3~5 h, amount of catalyst 10 mmol(n K2CO3/n phenol=l).%在超临界CO2中以K2CO3为催化剂,由苯酚一步直接合成了水杨酸.改进了传统的有机酚酸(Kolbe-Schmitt 反应)的两步法合成工艺.在CO2压力4~14 MPa、温度160~220℃,考察温度、压力、反应时间、催化剂用量等条件对水杨酸收率的影响.水杨酸最高得率接近54%,产物的选择性在99%以上,副产物有极少量对羟基苯甲酸.较为理想的反应条件为:反应温度190℃,反应压力8 MPa,反应时间3~5 h,催化剂用量10 mmol(nk2co3/n phenol=1).

  8. Aerobic and anaerobic power characteristics of competitive cyclists in the United States Cycling Federation.

    Science.gov (United States)

    Tanaka, H; Bassett, D R; Swensen, T C; Sampedro, R M

    1993-08-01

    The purpose of this study was to characterize the aerobic and anaerobic capabilities of United States Cycling Federation cyclists in different categories. To determine aerobic and anaerobic power, 38 competitive road cyclists (32 males, 6 females) performed a VO2max test and a Wingate anaerobic test, respectively. Male cyclists in category II had the highest VO2max, both in absolute and relative terms. Their VO2max was 6% and 10% higher than category III and IV cyclists, respectively (4.98 +/- 0.14 vs 4.72 +/- 0.15 vs 4.54 +/- 0.12 l/min). A significant difference existed between category II and IV male cyclists (p < 0.05). VO2max for female cyclists (3.37 +/- 0.13 l/min) was significantly (p < 0.05) lower than those for males. The Wingate anaerobic test revealed that male cyclists in category II also had the highest anaerobic power output. The peak power output in category II, III and IV was 13.86 +/- 0.23, 13.55 +/- 0.25, and 12.80 +/- 0.41 W/kg, respectively. The mean power output in category II, III, and IV was 11.22 +/- 0.18, 11.06 +/- 0.15, and 10.40 +/- 0.30 W/kg, respectively. The difference in the mean power output between category II and IV was significant (p < 0.05). Female cyclists recorded significantly less peak and mean power output than their male counterparts (p < 0.05). However, when expressed relative to lean body mass, anaerobic power was similar for both sexes. No inter-correlation was found in any measurement between the aerobic and anaerobic power values. On the whole, category II male cyclists were characterized by higher aerobic and anaerobic power outputs.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. The impact of the menstrual cycle and hormonal contraceptives on competitiveness

    NARCIS (Netherlands)

    Buser, T.

    2012-01-01

    We examine whether competitiveness in women is influenced by biological factors. Female participants in a laboratory experiment solve a simple arithmetics task first under a piece rate and then under a competitive tournament scheme. Participants can then choose which compensation scheme to apply in

  10. Scaling from individual plants to the globe in an Earth System Model: height structured competition and carbon cycling

    Science.gov (United States)

    Weng, E.; Malyshev, S.; Lichstein, J. W.; Farrior, C. E.; Dybzinski, R.; Zhang, T.; Shevliakova, E.; Pacala, S. W.

    2014-12-01

    The long-term and large scale dynamics of ecosystems are in large part determined by the performances of individual plants in competition with one another for light, water and nutrients. Woody biomass, a pool of carbon (C) larger than that in the atmosphere, exists because of height-structured competition for light. However, none of the current Earth System Models that predict climate change and C cycle feedbacks includes a mechanistic formulation for height-structured competition for light, or an explicit scaling from individual plants to the globe. In this study, we incorporate height-structured competition and explicit scaling from individuals to ecosystems into the land model (LM3) currently used in the Earth System Models developed by the Geophysical Fluid Dynamics Laboratory based on the Perfect Plasticity Approximation model (PPA), which has been shown to scale accurately from individual plants to stands in individual-based simulation models of plant competition for light, water and nutrients. Because of the tractability of the PPA, the coupled LM3-PPA model is able to include a large number of phenomena across a range of spatial and temporal scales, and still retain computational and mathematical tractability. We test a range of predictions against data from the temperate forests in northern USA. The results show the model predictions agree with diurnal and annual C fluxes, growth rates of individual trees in the canopy and understory, tree size distributions, and species-level population dynamics during succession. We also show how the competitively optimal allocation strategy shifts at different atmospheric CO2 concentrations due to competition with alternative strategies in the model. The results show that the competitively optimal allocation of carbon to leaves, wood, and fine roots depends on the atmospheric CO2 concentration, and that C sinks caused by CO2 fertilization in forests limited by light and water are down-regulated if allocation tracks

  11. 地层水侵入对超临界CO2钻井井筒温度和压力的影响%Influences of formation water invasion on the well bore temperature and pressure in supercritical CO2 drilling

    Institute of Scientific and Technical Information of China (English)

    王海柱; 沈忠厚; 李根生

    2011-01-01

    Aiming to study the influence of formation water invasion on the well bore temperature and pressure in SC-CO2 (supercritical CO2) drilling with coiled tubing, this paper builds up a weilbore flow model with formation water invasion in SC-CO2 drilling with coiled tubing, based on the comprehensive investigation of the influence of viscosity, density, thermal conductivity, isobaric heat capacity and Joule-Thompson coefficient of SC-CO2. The wellbore temperature and pressure distribution were calculated by the method of coupling among these parameters. The results show that the bigger the rate of invaded formation water and the bigger the density of mixed fluid,the bigger the convective heat transfer coefficient in the annulus. Because of the .Joule-Thompson cooling effect caused by nozzle throttling, the annulus mixture fluid density increased abruptly and the convective heat transfer coefficient decreased abruptly at the well depth of about 1 900 m (about 10 m to bottom hole). Meanwhile the wellbore fluid temperature increased with the invasion rate of formation water, and the same Joule-Thompson cooling effect caused the wellbore fluid temperature to decrease abruptly at the well depth of about 1 900 m. Moreover, the wellbore annulus pressure increased with the increasing of invaded formation water quantity, butthe amplitude is not obvious.%为了研究sC-CO(超临界CO)连续油管钻井过程中地层水侵入对井筒温度和压力的影响,在综合考虑CO流体的黏度、密度、导热系数、热容、焦耳-汤姆逊系数等参数影响的基础上,建立了SC-CO连续油管钻井地层水侵入井筒流动模型,并采用各参数相互耦合的方法对井筒温度和压力分布进行了计算.结果表明,地层水侵入速度越大其混合流体密度越高,环空混合流体对流换热系数越大,但由于喷嘴节流产生的焦耳-汤姆逊冷却效应,在井深约1 900 m处(离井底约10 m处)环空混合流体密度突然增大、对流

  12. Competition in size-structured populations: mechanisms inducing cohort formation and population cycles

    NARCIS (Netherlands)

    de Roos, A.M.; Persson, L.

    2003-01-01

    In this paper we investigate the consequences of size-dependent competition among the individuals of a consumer population by analyzing the dynamic properties of a physiologically structured population model. Only 2 size-classes of individuals are distinguished: juveniles and adults. Juveniles and a

  13. CCND1-CDK4-mediated cell cycle progression provides a competitive advantage for human hematopoietic stem cells in vivo.

    Science.gov (United States)

    Mende, Nicole; Kuchen, Erika E; Lesche, Mathias; Grinenko, Tatyana; Kokkaliaris, Konstantinos D; Hanenberg, Helmut; Lindemann, Dirk; Dahl, Andreas; Platz, Alexander; Höfer, Thomas; Calegari, Federico; Waskow, Claudia

    2015-07-27

    Maintenance of stem cell properties is associated with reduced proliferation. However, in mouse hematopoietic stem cells (HSCs), loss of quiescence results in a wide range of phenotypes, ranging from functional failure to extensive self-renewal. It remains unknown whether the function of human HSCs is controlled by the kinetics of cell cycle progression. Using human HSCs and human progenitor cells (HSPCs), we report here that elevated levels of CCND1-CDK4 complexes promoted the transit from G0 to G1 and shortened the G1 cell cycle phase, resulting in protection from differentiation-inducing signals in vitro and increasing human leukocyte engraftment in vivo. Further, CCND1-CDK4 overexpression conferred a competitive advantage without impacting HSPC numbers. In contrast, accelerated cell cycle progression mediated by elevated levels of CCNE1-CDK2 led to the loss of functional HSPCs in vivo. Collectively, these data suggest that the transition kinetics through the early cell cycle phases are key regulators of human HSPC function and important for lifelong hematopoiesis. © 2015 Mende et al.

  14. GC-MS Analysis and Biological Activities in vitro of the Supercritical CO2 Extracts from the Roots of Poly-althia nemoralis%陵水暗罗根超临界CO2萃取物的GC-MS分析及其体外生物活性评价

    Institute of Scientific and Technical Information of China (English)

    黄冬苑; 刘嘉炜; 李武国; 林伟杰

    2016-01-01

    OBJECTIVE:To extract and identify the volatile components of the roots of Polyalthia nemoralis,and to evaluate its biological activity in vitro. METHODS:Supercritical CO2 extraction (SFE-CO2) was performed to extract volatile compounds from the roots of P. nemoralis,and the volatile components were separated and determined by GC-MS. Human hepatic cancer Huh-7 cells were cultured with 0(blank control),5,10,20,30,40 and 50 μg(medicinal material)/ml extract for 24 h,and then MTT assay was used to detect the inhibitory effect of the extracts on cells. Relative cell viability and IC50 were calculated. The an-ti-bacterial activities of extract to Staphylococcus aureus,Methicillin-resistant Staphylococcus aureus,Enterococcus faecalis and oth-er strain were determined by Kirby-bauer method and broth dilution method. RESULTS:Forty compounds were identified from the SFE-CO2 extracts from the roots of P. nemoralis. The main constituents were(Z,Z,Z)-9,12,15-octa-decatrien-1-ol,glycerin,cinna-maldehyde,n-hexadecanoic acid and eugenol. Compared with blank control group,SFE-CO2 extracts from the roots of P. nemoralis 5 μg(medicinal material)/ml and above showed significant inhibitory effect on cell growth(P<0.05),and the inhibitory effect was strengthened as the concentration of extracts increased,IC50 values was 5.2 μg(medicinal material)/ml. However,the supercritical extract didn't showed antibacterial activity against three microorganisms in 2 kinds of antibacterial tests. CONCLUSIONS:SFE-CO2 and GC-MS method can effectively extract and identify volatile components of the roots of P. nemoralis,and supercritical extracts can inhibit the viability of cells but have no antibacterial activity.%目的:提取、鉴定陵水暗罗根提取物中挥发性成分,并评价其体外生物活性.方法:采用超临界CO2萃取法提取陵水暗罗根中的挥发性化学成分,气相色谱-质谱联用(GC-MS)法分析其化学成分组成;以0(空白对照)、5、10、20、30、40、50

  15. Blow Up of a Cycle in Lotka-Volterra Type Equations with Competition-Cooperation Terms and Quasi-Linear Systems

    CERN Document Server

    Bouse, E

    2010-01-01

    We consider systems where a cycle born via the Hopf bifurcation blows up to infinity as a parameter ranges over a finite interval. Two examples demonstrating this effect are presented: planar Lotka-Volterra type systems with a competition-cooperation term and quasi-linear higher order equations.

  16. Evolution of Tidal Influence During the ETS Seismic Cycle Reveals Competition Between Tectonic Loading and Fault Healing

    Science.gov (United States)

    Houston, H.

    2015-12-01

    Following the discovery of the evolution of tremor response to tidal stress over the duration of ETS slip at a spot (Houston 2015; Royer et al 2015;Yabe et al 2015), we investigate whether and how it may evolve between major large ETSs, which occur quasi-periodically in several subduction zones. Preliminary results show that tidal response does evolve over the average interETS period in northern Cascadia - decaying over the first quarter of the cycle to lowest values then climbing back up in the second half of the cycle part of the way toward the strong response seen late during major ETSs. Thus far, we have ignored the possible role of transient stresses during interETS tremor because tremor bursts are mostly small. We explore a strength-threshold model where tidal influence is stronger when stress is close to strength and weaker when they are farther apart. Shortly after a major ETS, both stress and strength are presumed to have fallen over the large region where slow slip occurred. Then, however, stress rebuilds quasi-linearly by plate tectonic loading, whereas strength rebuilds as the logarithm of time (e.g., Vidale et al 1994). Thus, model stress and strength diverge the most midway through the interETS cycle, the period of weakest tidal sensitivity. Tidal stresses become more effective in triggering tremor later in the cycle as the linearly-growing stress approaches the logarithmically-growing strength. This model broadly fits our observed evolution of tidal response. However, the tendency of ETSs to initiate downdip may require an additional process that varies along dip. This approach illuminates the competition between healing on the plate interface and reloading with tectonic stress, and can help constrain and perhaps even monitor physical conditions on the deep subduction interface. The figure shows the evolution of two measures of tidal influence on tremor, consistency and sensitivity (right), and the data on which they are based - probability

  17. The effect of a one-piece competition speedsuit on swimming performance and thermoregulation during a swim-cycle trial in triathletes.

    Science.gov (United States)

    Peeling, Peter; Landers, Grant

    2007-10-01

    This study investigated the thermoregulatory response to wearing a one-piece competition speedsuit during the swim-cycle aspect of a sprint-distance triathlon. Eight highly trained, male triathletes completed a graded-exercise test, and two swim-cycle trials including a 750 m swimming time trial followed by 30 min of cycling at 95% lactate threshold. Cycling was conducted inside a climate regulated chamber set to 30.0+/-0.3 degrees C and 60.3+/-0.3% humidity. Throughout each swim-cycle testing session, the athletes wore either standard swimming bathers only (BATHERS), or a competition speedsuit (SPEEDSUIT). During the swim-cycle trial, the athletes core temperature (T(c)) and skin temperature (T(sk)) were recorded via a telemetric temperature pill and a series of skin thermistors, respectively. Blood lactate concentration (BLa), heart rate (HR) and ratings of perceived thermal sensation (RPTS) were collected at the conclusion of the swim and during cycling. The SPEEDSUIT swim time (590+/-20s) was significantly faster (3.2%, p0.05). During the 30 min cycle, there were not significant differences between the mean values for power output, T(c), T(sk), HR, BLa or RPTS (SPEEDSUIT: 289+/-13W, 38.65+/-0.27 degrees C, 34.30+/-0.71 degrees C, 7.8+/-1.1 mmol L(-1), 17+/-1, BATHERS: 288+/-14W, 38.35+/-0.10 degrees C, 33.50+/-0.57 degrees C, 7.1+/-0.9 mmol L(-1), 17+/-1, respectively) (p>0.05). The use of a competition speedsuit improved the triathletes' swim time without effecting temperature regulation during a laboratory-based swim-cycle trial.

  18. Unholy marriages and eternal triangles: how competition in the mushroom life cycle can lead to genomic conflict

    Science.gov (United States)

    Nygren, Kristiina; Aanen, Duur K.

    2016-01-01

    In the vast majority of sexual life cycles, fusion between single-celled gametes is directly followed by nuclear fusion, leading to a diploid zygote and a lifelong commitment between two haploid genomes. Mushroom-forming basidiomycetes differ in two key respects. First, the multicellular haploid mating partners are fertilized in their entirety, each cell being a gamete that simultaneously can behave as a female, i.e. contributing the cytoplasm to a zygote by accepting nuclei, and a male gamete, i.e. only donating nuclei to the zygote. Second, after gamete union, the two haploid genomes remain separate so that the main vegetative stage, the dikaryon, has two haploid nuclei per cell. Only when the dikaryon produces mushrooms, do the nuclei fuse to enter a short diploid stage, immediately followed by meiosis and haploid spore formation. So in basidiomycetes, gamete fusion and genome mixing (sex) are separated in time. The ‘living apart together’ of nuclei in the dikaryon maintains some autonomy for nuclei to engage in a relationship with a different nucleus. We show that competition among the two nuclei of the dikaryon for such ‘extramarital affairs’ may lead to genomic conflict by favouring genes beneficial at the level of the nucleus, but deleterious at that of the dikaryon. This article is part of the themed issue ‘Weird sex: the underappreciated diversity of sexual reproduction’. PMID:27619697

  19. Deceptive manipulation of competitive starting strategies influences subsequent pacing, physiological status and perceptual responses during cycling time trials

    Directory of Open Access Journals (Sweden)

    Emily L Williams

    2016-11-01

    Full Text Available Little is currently known regarding competitor influence on pacing at the start of an event and in particular the subsequent effect on the remaining distance. The purpose of the present study was to investigate the influence of starting pace on the physiological and psychological responses during cycling time trials (TT utilising an innovative approach allowing pace to be accurately and dynamically replicated, as well as deceptively manipulated. Ten competitive male cyclists completed five 16.1 km TT, two baseline trials performed alone (BLs, and three with a simulated, dynamic avatar of which they were to match the pace of for the initial 4 km. The avatar represented either the cyclist’s fastest BL performance (NORM, 105% (FAST, or 95% (SLOW, of fastest BL performance (FBL. Physiological and psychological responses were measured every quartile of the TT. Despite manipulating a starting speed of ± 5% of fastest previous performance, there was no effect on overall 16.1 km TT performance. Manipulated starting strategies did however evoke different physiological and perceptual responses. Whole trial differences found that SLOW produced lower HR, VO2, BLa and RPE than FBL (p ≤ 0.03 and higher SE than FAST (p ≤ 0.03. Additionally, FAST had greater internal attention than NORM (p < 0.04. Over time all psychological and physiological variables had a significant condition x quartile interaction in the initial or second quartile mediated by the prescribed starting strategies. Furthermore, RPE, affect and internal attention remained elevated throughout FAST despite an attenuation in pace during self-selection of pace. There were no differences in performance time when manipulating a 16.1km cycling TT starting strategy. A slow start, encouraged greater positive perceptions, less negative physiological consequences than a faster start, and produces no impairment to performance time. It would therefore be considered an advantage in a non

  20. Competitive interactions between methane- and ammonia-oxidizing bacteria modulate carbon and nitrogen cycling in paddy soil

    Directory of Open Access Journals (Sweden)

    Y. Zheng

    2014-03-01

    Full Text Available Pure culture studies have demonstrated that methanotrophs and ammonia oxidizers can both carry out the oxidation of methane and ammonia. However, the expected interactions resulting from these similarities are poorly understood, especially in complex, natural environments. Using DNA-based stable isotope probing and pyrosequencing of 16S rRNA and pmoA genes, we report on biogeochemical and molecular evidence for growth stimulation of methanotrophic communities by ammonium fertilization, and that methane modulates nitrogen cycling by competitive inhibition of nitrifying communities in a rice paddy soil. Pairwise comparison between microcosms amended with CH4, CH4+Urea, and Urea indicated that urea fertilization stimulated methane oxidation activity by 6-fold during a 19 day incubation period, while ammonia oxidation activity was significantly inhibited in the presence of CH4. Pyrosequencing of the total 16S rRNA genes revealed that urea amendment resulted in rapid growth of Methylosarcina-like type Ia MOB, and nitrifying communities appeared to be suppressed by methane. High-throughput sequencing of the 13C-labeled DNA further revealed that methane amendment resulted in clear growth of Methylosarcina-related MOB while methane plus urea led to equal increase in Methylosarcina and Methylobacter-related MOB, indicating the differential growth requirements of representatives of these genera. Strikingly, type Ib MOB did not respond to methane nor to urea. Increase in 13C-assimilation by microorganisms related to methanol oxidizers clearly indicated carbon transfer from methane oxidation to other soil microbes, which was enhanced by urea addition. The active growth of type Ia methanotrops was significantly stimulated by urea amendment, and the pronounced growth of methanol-oxidizing bacteria occurred in CH4-treated microcosms only upon urea amendment. Methane addition inhibited the growth of Nitrosospira and Nitrosomonas in urea-amended microcosms, in

  1. Competitive interactions between methane- and ammonia-oxidizing bacteria modulate carbon and nitrogen cycling in paddy soil

    Science.gov (United States)

    Zheng, Y.; Huang, R.; Wang, B. Z.; Bodelier, P. L. E.; Jia, Z. J.

    2014-06-01

    Pure culture studies have demonstrated that methanotrophs and ammonia oxidizers can both carry out the oxidation of methane and ammonia. However, the expected interactions resulting from these similarities are poorly understood, especially in complex, natural environments. Using DNA-based stable isotope probing and pyrosequencing of 16S rRNA and functional genes, we report on biogeochemical and molecular evidence for growth stimulation of methanotrophic communities by ammonium fertilization, and that methane modulates nitrogen cycling by competitive inhibition of nitrifying communities in a rice paddy soil. Pairwise comparison between microcosms amended with CH4, CH4+Urea, and Urea indicated that urea fertilization stimulated methane oxidation activity 6-fold during a 19-day incubation period, while ammonia oxidation activity was significantly suppressed in the presence of CH4. Pyrosequencing of the total 16S rRNA genes revealed that urea amendment resulted in rapid growth of Methylosarcina-like MOB, and nitrifying communities appeared to be partially inhibited by methane. High-throughput sequencing of the 13C-labeled DNA further revealed that methane amendment resulted in clear growth of Methylosarcina-related MOB while methane plus urea led to an equal increase in Methylosarcina and Methylobacter-related type Ia MOB, indicating the differential growth requirements of representatives of these genera. An increase in 13C assimilation by microorganisms related to methanol oxidizers clearly indicated carbon transfer from methane oxidation to other soil microbes, which was enhanced by urea addition. The active growth of type Ia methanotrops was significantly stimulated by urea amendment, and the pronounced growth of methanol-oxidizing bacteria occurred in CH4-treated microcosms only upon urea amendment. Methane addition partially inhibited the growth of Nitrosospira and Nitrosomonas in urea-amended microcosms, as well as growth of nitrite-oxidizing bacteria. These

  2. Reflection on Full Life Cycle Green Architectural Design of Passive Priority---Taking the Award Design of China Merchants Property 2013 Green Architectural Design Competition as an Example

    Institute of Scientific and Technical Information of China (English)

    ZhenHe Fan; Yan Qiao

    2014-01-01

    In the China merchants property 2013 green architectural design competition, feature of this award-winning program is the design method based on the principles of passive priority and comprehensive utilization of full life cycle. The passive priority can be achieved by building form derived from the simulation and analysis of wind environment, improvement of the building envelope insulation and the dehumidification of fresh air, the use of solar energy. The full life cycle utilization can be accomplished by the combination of exhibition and residents’ leisure activities, and the integration with local cultural tradition, thereby improving energy efficiency and the utilization of the building.

  3. 竞技健美操年度训练周期特征%Features of annual training cycle of competitive aerobics

    Institute of Scientific and Technical Information of China (English)

    李芳; 郑丽敏; 李非

    2011-01-01

    竞技健美操的训练周期是根据运动员竞技状态的形成和发展规律以及重大比赛日程而制定的,一个完整的训练周期包括准备期、竞赛期和过渡期三个相对独立而又互相联系的训练过程。准备期、竞赛期和过渡期每个训练时期都有不同的训练时间、训练内容、训练方法和负荷变化,每个时期都有其独特的周期特征。%The training cycle of the competitive aerobics is designed according to the athlete's competitive state and development rules and the schedules of the important competitions.A complete training cycle consists of preparation period,competition period and transition period.Each period has its own training time,training content,training method and load change.Each period has its own features.

  4. Dietary Intake, Body Composition, and Menstrual Cycle Changes during Competition Preparation and Recovery in a Drug-Free Figure Competitor: A Case Study

    Science.gov (United States)

    Halliday, Tanya M.; Loenneke, Jeremy P.; Davy, Brenda M.

    2016-01-01

    Physique competitions are events in which competitors are judged on muscular appearance and symmetry. The purpose of this retrospective case study was to describe changes in dietary intake, body mass/composition, and the menstrual cycle during the 20-week competition preparation (PREP) and 20-week post competition recovery (REC) periods of a drug-free amateur female figure competitor (age = 26–27, BMI = 19.5 kg/m2). Dietary intake (via weighed food records) and body mass were assessed daily and averaged weekly. Body composition was estimated via Dual-energy X-ray absorptiometry (DXA) and 7-site skinfold measurements. Energy intake, body mass and composition, and energy availability decreased during the 20-week PREP period (changes of ~298 kcals, 5.1 kg, 6.5% body fat, and 5.4 kcal/kg fat free mass, respectively) and returned to baseline values by end of the 20-week REC period. Menstrual cycle irregularity was reported within the first month of PREP and the last menstruation was reported at week 11 of PREP. Given the potentially adverse health outcomes associated with caloric restriction, future, prospective cohort studies on the physiological response to PREP and REC are warranted in drug-free, female physique competitors. PMID:27879627

  5. 半夏等6种中药超临界CO2萃取物对青霉素诱发大鼠痫性放电和海马区相关递质含量的比较研究%Comparative study of 6 kinds of Chinese herbal medicine of supercritical CO2 extract of penicillin induced epileptic discharge and related neurotransmitters in hippocampus

    Institute of Scientific and Technical Information of China (English)

    杨蓉; 王明正; 成银霞

    2013-01-01

    Objective:To compare the anticonvulsion effect of supercritical-CO2 fluid extractions(SFE-CO2) of Pinellia Tuber et al,on the mode of seizure rats induced by penicillin and explore its mechanism of anticonvulsant action.Methods:Using the model of seizure rats induced by penicillin localized injected in cortex investigated the effect of extractions on the convulsant behaviors and hippocampus EEG.The neurotransmitters (Glu,Asp,Gly and GABA) of extractions in hippocampus were determined by high performance liquid chromatography (HPLC).Results:(1) PT Ⅱ,RP Ⅱ,UN l,RAT Ⅰ,RATⅡ and RB Ⅰ can prolong the latent period of epileptiform discharge,reduce the frequency of epileptiform discharge,and decrease the highest wave of hippocampus EEG.(2) UN Ⅱ and PT Ⅱ can significantly decrease the level of Glu(P<0.05) ; RB Ⅰ,RAT Ⅰ,RPⅡ and PTⅡ can obviously increase the level of GABA(P <0.01 or P <0.05).Conclusions:(1) PT Ⅱ,RP Ⅱ,UN Ⅱ,RAT Ⅰ and RB Ⅰ can antagonize penicillin-kindling seizure in rats.PT Ⅱ was the most effective extraction to antagonize the penicillin-induced seizure.Anticonvulsant properties of PT Ⅱ resembled Topamax,and the effect of it was better than Topamax.(2) The anticonvulsant mechanism of RB Ⅰ,RAT Ⅰ and RP Ⅱmight have been due to increase the level of GABA,however,UN Ⅱ related to decrease Glu level.The anticonvulsant mechanism of PT Ⅱ might had relation with these two aspects.%目的:比较半夏等6种中草药的超临界CO2萃取物对大鼠皮层定位注射青霉素诱发惊厥模型的对抗作用,并探讨其作用机制.方法:建立大鼠皮层定位注射青霉素惊厥模型,比较灌胃各药对惊厥行为和脑电图的影响;采用HPLC法比较各药对海马区Glu、Asp、Gly和GABA的含量影响.结果:(1)半Ⅱ、柴Ⅰ、天Ⅱ、钩Ⅱ、石Ⅰ、石Ⅱ均可不同程度地延长青霉素诱发痫性的发作潜伏期,减轻发作程度,延长痫性放电的潜伏期,减少痫波发放频

  6. CCND1–CDK4–mediated cell cycle progression provides a competitive advantage for human hematopoietic stem cells in vivo

    Science.gov (United States)

    Mende, Nicole; Kuchen, Erika E.; Lesche, Mathias; Grinenko, Tatyana; Kokkaliaris, Konstantinos D.; Hanenberg, Helmut; Lindemann, Dirk; Dahl, Andreas; Platz, Alexander; Höfer, Thomas; Calegari, Federico

    2015-01-01

    Maintenance of stem cell properties is associated with reduced proliferation. However, in mouse hematopoietic stem cells (HSCs), loss of quiescence results in a wide range of phenotypes, ranging from functional failure to extensive self-renewal. It remains unknown whether the function of human HSCs is controlled by the kinetics of cell cycle progression. Using human HSCs and human progenitor cells (HSPCs), we report here that elevated levels of CCND1–CDK4 complexes promoted the transit from G0 to G1 and shortened the G1 cell cycle phase, resulting in protection from differentiation-inducing signals in vitro and increasing human leukocyte engraftment in vivo. Further, CCND1–CDK4 overexpression conferred a competitive advantage without impacting HSPC numbers. In contrast, accelerated cell cycle progression mediated by elevated levels of CCNE1–CDK2 led to the loss of functional HSPCs in vivo. Collectively, these data suggest that the transition kinetics through the early cell cycle phases are key regulators of human HSPC function and important for lifelong hematopoiesis. PMID:26150472

  7. Development of a Novel Catalytic Membrane Reactor for Heterogeneous Catalysis in Supercritical CO2

    Directory of Open Access Journals (Sweden)

    Toshiro Yokoyama

    2010-01-01

    Full Text Available A novel type of high-pressure membrane reactor has been developed for hydrogenation in supercritical carbon dioxide (scCO2. The main objectives of the design of the reactor are the separate feeding of hydrogen and substrate in scCO2 for safe reactions in a continuous flow process, and to reduce the reaction time. By using this new reactor, hydrogenation of cinnamaldehyde into hydrocinnamaldehyde has been successfully carried out with 100% selectivity at 50 °C in 10 MPa (H2: 1 MPa, CO2: 9 MPa with a flow rate of substrate ranging from 0.05 to 1.0 mL/min.

  8. Phase equilibria of oleic, palmitic, stearic, linoleic and linolenic acids in supercritical CO2

    Directory of Open Access Journals (Sweden)

    P. L. Penedo

    2009-03-01

    Full Text Available The knowledge of the phase equilibrium is one of the most important factors to study the design of separation processes controlled by the equilibrium. Fatty acids are present in high concentration as by-products in vegetable oils but the equilibrium data involving these components is scarce. The objective of this work is the experimental determination of the liquid-vapor equilibrium of five binary different systems formed by carbon dioxide and palmitic acid (C16:0, stearic acid (C18:0, oleic acid (C18:1, linoleic acid (C18:2 and linolenic acid (C18:3. The equilibrium experimental data was collected at 40, 60 and 80ºC at 60, 90 and 120 bar, at the extract and raffinate phases, using an experimental apparatus containing an extractor, a gas cylinder and pressure and temperature controllers. The data was modeled using the cubic equation of state of Peng-Robinson with the mixing rule of van der Waals with binary interaction parameters. The model was adequate to treat the experimental data at each temperature and at all the temperatures together. The best model that includes the van der Waals mixing rule with two parameters has maximum deviation of 17%. The distribution coefficients were also analyzed and it was concluded that the fractionation of the fatty acids is possible using supercritical carbon dioxide.

  9. Supercritical CO2 as a substitute of volatile hydrocarbons; Superkritisch CO2 vervangt vluchtige koolwaterstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Folkerts, G. (ed.)

    2006-05-15

    In many cases supercritical carbon dioxide can replace volatile hydrocarbons in extraction processes. Currently gaseous or liquid CO2 is already used for industrial purification processes, extraction of caffeine from coffee and as a solvent for paint. Although supercritical extraction s a batch process the technique can be applied as a continuous process. [Dutch] In processen waar vluchtige koolwaterstoffen worden ingezet om stoffen te extraheren, biedt superkritisch CO2 een milieuvriendelijk alternatief. Het koolzuur dat zowel in de vloeistof- als gasfase zit, wordt dan ook steeds meer ingezet in extractieprocessen.

  10. Supercritical CO2 interpolymer complex encapsulation improves heat stability of probiotic bifidobacteria

    CSIR Research Space (South Africa)

    Thantsha, MS

    2014-02-01

    Full Text Available The probiotic industry faces the challenge of retention of probiotic culture viability as numbers of these cells within their products inevitably decrease over time. In order to retain probiotic viability levels above the therapeutic minimum over...

  11. Carotenoids extraction from Japanese persimmon (Hachiya-kaki) peels by supercritical CO(2) with ethanol.

    Science.gov (United States)

    Takahashi, Mayako; Watanabe, Hiromoto; Kikkawa, Junko; Ota, Masaki; Watanabe, Masaru; Sato, Yoshiyuki; Inomata, Hiroshi; Sato, Nobuyuki

    2006-11-01

    The extraction of carotenoids from Japanese persimmon peels by supercritical fluid extraction (SFE), of which the solvent was CO(2), was performed. In order to enhance the yield and selectivity of the extraction, some portion of ethanol (5 - 20 mol%) was added as an entrainer. The extraction temperature ranged from 313 to 353 K and the pressure was 30 MPa. The effect of temperature on the extraction yield of carotenoids was investigated at 10 mol% of the ethanol concentration in the extraction solvent, and a suitable temperature was found to be 333 K among the temperatures studied with respect to the carotenoid yield. With increasing the entrainer amount from 0 to 10 mol% at a constant temperature (333 K), the carotenoid yield in the extraction was improved, whereas the selectivity of the extracted carotenoids was drastically depressed. We also conducted qualitative and quantitative analyses for the carotenoid components in the extract by HPLC, and analyzed the extraction behavior of each individual carotenoid (alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, lutein, and zeaxanthin). The selectivity of each carotenoid changed with the elapsed time and its time evolution was dependent on the carotenoid component, indicating that the location profile and the content can be important factors to understand the SFE behavior of each carotenoid in persimmon peels.

  12. Supercritical CO2: a ‘green’ route for the encapsulation of drugs

    CSIR Research Space (South Africa)

    Labuschagne, Philip W

    2010-09-01

    Full Text Available -PVP loaded with ibuprofen (a non-steroidal anti-inflammatory drug often used in transdermal delivery for treatment of rheumatoid arthritis and osteoarthritis) were prepared. One of the requirements for effective transdermal delivery is that the drug...

  13. Pretreatment of Corn Stover Using Supercritical CO2 with Water-Ethanol as Co-solvent

    Institute of Scientific and Technical Information of China (English)

    L(U) Huisheng; REN Miaomiao; ZHANG Minhua; CHEN Ying

    2013-01-01

    Supercritical carbon dioxide,with water-ethanol as co-solvent,was applied to pretreat corn stover to enhance its enzymatic hydrolysis.The efficiency of pretreatment was evaluated by the final reducing sugar yield obtained from the enzymatic hydrolysis of cellulose.Under the operation conditions of pretreatment pressure 15 MPa,temperature 180 ℃ and time 1 h,the optimal sugar yield of 77.8% was obtained.Scanning electron microscopy (SEM) and chemical composition analysis were applied to the pretreated corn stover.The results showed that the surface morphology and microscopic structure of pretreated corn stover were greatly changed.After the pretreatment,the contents of hemicellulose and lignin were reduced obviously.Thus more cellulose was exposed,increasing the sugar yield.

  14. Assembling Metal-Organic Frameworks in Ionic Liquids and Supercritical CO2.

    Science.gov (United States)

    Zhang, Bingxing; Zhang, Jianling; Han, Buxing

    2016-10-06

    Ionic liquids (ILs) and supercritical carbon dioxide (scCO2 ) are both considered to be green solvents with tunable properties. Recently, studies of the synthesis of metal-organic frameworks (MOFs) in the presence of ILs and scCO2 has become a burgeoning direction in chemistry and materials science. ILs have been shown to be ideal media for the synthesis of a variety of MOFs owing to their unique properties including the ability to dissolve a wide range of organic and inorganic compounds and flexible designability. scCO2 has adjustable solvent power and excellent mass-transfer characteristics that offer the opportunity to replace organic solvents for MOF activation, MOF aerogel synthesis, and MOF construction. More interestingly, the simultaneous utilization of IL and scCO2 can combine the advantages of the two liquids, which provides novel routes for the fabrication of MOF structures. This review describes the advances in MOF synthesis in ILs, scCO2 , and IL/scCO2 systems. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Microparticle Formation and Crystallization Rate of HMX with Supercritical CO2 Antisolvent Recrystallization

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Microparticle formation and crystallization rate of 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX) in acetone solution using supercritical carbon dioxide antisolvent (GAS) recrystallization were studied. Scanning electronic microscopy, X-ray diffraction and infrared radiation were used to examine particle size, crystallinity and chemical structure. The results show that β-HMX microparticle in different average size (2-9.5μm) and with narrow size distribution were obtained by controlling the expansibility, expansion speed, initial concentration and temperature during recrystallization of HMX. The formation of nuclei may be a main cause of consumption of solute when the solution is expanded rapidly enough and the equilibrium concentration is lower, in which almost monodisperse microparticle can be obtained.

  16. Microparticle Formation and Crystallization Rate of HMX with Supercritical CO2 Antisolvent Recrystallization

    Institute of Scientific and Technical Information of China (English)

    蔡建国; 周展云; 邓修

    2001-01-01

    Microparticle formation and crystallization rate of 1,3,5,7-tetranitro-l,3,5,7-tetraazacyclooctane (HMX) in acetone solution using supercritical carbon dioxide antisolvent (GAS) recrystallization were studied. Scanning electronic microscopy, X-ray diffraction and infrared radiation were used to examine particle size, crystallinity and chemical structure. The results show that β-HMX microparticle in different average size (2--9.5μm) and with narrow size distribution were obtained by controlling the expansibility, expansion speed, initial concentration and temperature during recrystallization of HMX. The formation of nuclei may be a main cause of consumption of solute when the solution is expanded rapidly enough and the equilibrium concentration is lower, in which almost monodisperse microparticle can be obtained.

  17. The cooling heat transfer characteristics of the supercritical CO2 in micro-fin tube

    Science.gov (United States)

    Lee, Ho-Saeng; Kim, Hyeon-Ju; Yoon, Jung-In; Choi, Kwang-Hwan; Son, Chang-Hyo

    2013-02-01

    This study intended to verify the cooling heat transfer characteristics of supercritical gas for refrigerating and air-conditioning devices that use CO2, a natural refrigerant, as the operating fluid. Experiments were performed with a gas cooler, which was the test part. The gas cooler was a heat exchanger made of a micro-fin tube with an inner diameter of 4.6 mm and an outer diameter of 5.0 mm. The experiment results are summarized as follows. The heat transfer coefficient, according to the mass flux, peaked at the low cooling pressure of 8.0 MPa in the gas cooler, and reached its minimum at the high pressure of 10.0 MPa. Furthermore, when the mass flux of the refrigerant increased, the coefficient increased faster with the lower cooling pressure in the gas cooler. The heat transfer coefficient, according to the shape of the heat transfer tube, showed that the maximum values of the CO2 cooling heat transfer coefficients of the smooth tube and the micro-fin tube were found at 44.7 °C, which were the pseudo-critical temperatures for the entrance pressures. It was found that the cooling heat transfer coefficient of the micro-fin tube increased by 12-39 % more than that of the smooth tube. The experiment results for the CO2 heat transfer coefficients of the smooth tube and the micro-fin tube were compared with the results estimated from previous correlations. It was found that the experiment values generally significantly differed from and the experiment values greater than the estimated values. The differences were especially greater in the vicinity of the critical temperature points. Based on these results, a new correlation was suggested that includes the density ratio and the specific heat ratio.

  18. Leaching of organic acids from macromolecular organic matter by non-supercritical CO2

    Science.gov (United States)

    Sauer, P.; Glombitza, C.; Kallmeyer, J.

    2012-04-01

    The storage of CO2 in underground reservoirs is discussed controversly in the scientific literature. The worldwide search for suitable storage formations also considers coal-bearing strata. CO2 is already injected into seams for enhanced recovery of coal bed methane. However, the effects of increased CO2 concentration, especially on organic matter rich formations, are rarely investigated. The injected CO2 will dissolve in the pore water, causing a decrease in pH and resulting in acidic formation waters. Huge amounts of low molecular weight organic acids (LMWOAs) are chemically bound to the macromolecular matrix of sedimentary organic matter and may be liberated by hydrolysis, which is enhanced by the acidic porewater. Recent investigations outlined the importance of LMWOAs as a feedstock for microbial life in the subsurface [1]. Therefore, injection of CO2 into coal formations may result in enhanced nutrient supply for subsurface microbes. To investigate the effect of high concentrations of dissolved CO2 on the release of LMWOAs from coal we developed an inexpensive high-pressure high temperature system that allows manipulating the partial pressure of dissolved gases at pressures and temperatures up to 60 MPa and 120° C, respectively. In a reservoir vessel, gases are added to saturate the extraction medium to the desired level. Inside the extraction vessel hangs a flexible and inert PVDF sleeve (polyvinylidene fluoride, almost impermeable for gases), holding the sample and separating it from the pressure fluid. The flexibility of the sleeve allows for subsampling without loss of pressure. Coal samples from the DEBITS-1 well, Waikato Basin, NZ (R0 = 0.29, TOC = 30%). were extracted at 90° C and 5 MPa, either with pure or CO2-saturated water. Subsamples were taken at different time points during the extraction. The extracted LMWOAs such as formate, acetate and oxalate were analysed by ion chromatography. Yields of LMWOAs were higher with pure water than with CO2-saturated water, revealing a suppressing effect of CO2. Both extractions had higher yields than those reported for soxhlet extraction [2]. LMWOAs found in the extraction fluid may not just result from hydrolysis but also from different secondary reactions. It was suggested that oxalate in aqueous extracts of coals is a result of the decomposition of 1,2-dihydroxy-carboxylic acids [3]. We assume that for oxalate (and maybe for other LMWOAs as well) the extraction yield is not only affected by hydrolysis but also by secondary reactions, which may be inhibited or suppressed in the presence of CO2 in the extraction medium. During soxhlet extraction the sample only gets into contact with freshly distilled water, not with an acidic fluid. This may explain the lower yields.

  19. Liberation of microbial substrates from macromolecular organic matter by non-supercritical CO2

    Science.gov (United States)

    Sauer, P.; Glombitza, C.; Kallmeyer, J.

    2012-12-01

    The worldwide search for suitable underground storage formations for CO2 also considers coal-bearing strata. CO2 is already injected into coal seams for enhanced recovery of coal bed methane. However, the geochemical and microbiological effects of increased CO2 concentrations on organic matter rich formations are rarely investigated. The injected CO2 will dissolve in the pore water, causing a decrease in pH and resulting in acidic formation waters. Low molecular weight organic acids (LMWOAs) are chemically bound to the macromolecular matrix of sedimentary organic matter and may be liberated by hydrolysis, which is enhanced under acidic conditions. Recent investigations outlined the importance of LMWOAs as a feedstock for subsurface microbial life [1]. Therefore, injection of CO2 into coal formations may result in enhanced nutrient supply for subsurface microbes. To investigate the effects of highly CO2-saturated waters on the release of LMWOAs from coal, we developed an inexpensive high-pressure-high-temperature system that allows manipulating the concentration of dissolved gases up to 60 MPa and 120°C, respectively. The sample is placed in a flexible, gas-tight and inert PVDF sleeve, separating it from the pressure fluid and allowing for subsampling without loss of pressure. Lignite samples from the DEBITS-1 well, Waikato Basin, NZ and the Welzow-Süd open-cast mine, Niederlausitz, Germany, were extracted at 90° C and 5 MPa, with either pure water, CO2-saturated water, CO2/NO2 or CO2/SO2-saturated water. Subsamples were taken at different time points during the 72 hrs. long extraction. Extraction of LMWOAs from coal samples with our pressurised system resulted in yields that were up to four times higher than those reported for Soxhlet extraction [2]. These higher yields may be explained by the fact that during Soxhlet extraction the sample only gets into contact with freshly distilled water, whereas in our system the extraction fluid is circulated, resulting in more acidic extraction conditions. In comparison to pure water extractions, CO2-saturated water affected the extraction yield in both directions by up to 40 percent. For the lignite from DEBITS-1 well, CO2-saturated water resulted in a permanently lower yield, whereas the lignites from the Lausitz showed an increase in formate and a decrease in oxalate. LMWOAs found in the extraction fluid may not just result from hydrolysis but also from different secondary reactions. It was suggested that oxalate in aqueous extracts of coals is a result of the decomposition of 1,2-dihydroxy-carboxylic acids [3]. We assume that for oxalate (and maybe for other LMWOAs as well) the extraction yield is not only affected by hydrolysis but also by secondary reactions, which may be suppressed in the presence of CO2 and other gasses dissolved in the extraction medium. These results show the importance of performing laboratory simulations of subsurface processes under conditions that resemble the true in-situ conditions as closely as possible. References [1] Glombitza et al., 2009, Org. Geochem. 40, 175-183 [2] Vieth et al., 2008, Org. Geochem. 39, 985-991 [3] Bou-Raad et al., 2000, Fuel 79, 1185-1193

  20. Supercritical CO2 extraction of functional compounds from Spirulina and their biological activity

    National Research Council Canada - National Science Library

    K.G, Mallikarjun Gouda; K, Udaya Sankar; R, Sarada; G.A, Ravishankar

    2015-01-01

    Supercritical carbon dioxide (SCCO2) extraction and fractionation of Spirulina platensis was carried out to obtain functional compounds with antioxidant, antimicrobial and enzyme inhibitory activities...

  1. Surface and Electrochemical Behavior of HSLA in Supercritical CO2-H2O Environment

    Energy Technology Data Exchange (ETDEWEB)

    M. Ziomek-Moroz; G. R. Holcomb; J. Tylczak; J. Beck; M. Fedkin; S. Lvov

    2012-01-11

    General corrosion was observed on high strength low alloy carbon steel after electrochemical impedance spectroscopy experiments (EIS) performed in H{sub 2}O saturated with CO{sub 2} at 50 C and 15.2 MPa. However, general and localized were observed on the same material surfaces after the EIS experiments performed in supercritical CO{sub 2} containing approximately 6100 ppmv H{sub 2}O at 50 C and 15.2 MPa. The general corrosion areas were uniformly covered by the FeCO{sub 3}-like phase identified by X-ray diffraction (XRD). In the area of localized corrosion, XRD also revealed FeCO{sub 3}-rich islands embedded in {alpha}-iron. The energy dispersive X-ray (EDX) analysis revealed high concentrations of iron, carbon, and oxygen in the area affected by general corrosion and in the islands formed in the area of localized corrosion. The real and imaginary impedances were lower in H{sub 2}O saturated with CO{sub 2} than those in the supercritical CO{sub 2} containing the aqueous phase indicating faster corrosion kinetics in the former.

  2. A Single-phase of Supercritical CO2/Polystyrene Solution in Foam Extrusion

    Institute of Scientific and Technical Information of China (English)

    WU Xiaodan; CENG Haohua; CAI Yiebin; PENG Yucheng

    2008-01-01

    The high quality single-phase solution of CO2/Polystyrene was achieved,by analyzing the influential factors for polymer microcellular foaming extrusion.The curve of pressure distribution along the barrel was determined.The axial position of gas-injecting port on the barrel was chosen form the results of stable foaming,and the number of gas-injecting ports in the circumference of the barrel was determined from the CO2 solubility in polymer.The effect of the screw rotation speed on CO2 solubility was studied,and the effects of pressure difference between the gas and the polymer melt on gas-injecting process and on the foaming stability were investigated.The influence of the gas temperature before injection on the single-phase of CO2/Polystyrene solution also was studied.

  3. Phase behavior of supercritical CO2 microemulsion with food-grade surfactant AOT

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yongsheng; AN Xueqin; SHEN Weiguo; ZHANG Yinghua

    2006-01-01

    Phase behavior of scCO2 microemulsion formed with food grade surfactant sodium bis-(2-ethylhexyl) sulfosuccinate (AOT) was studied. Critical microemulsion concentration (cμc) was deduced from the dependence of pressure of cloud points on the concentration of surfactant AOT at constant temperature and water concentration. The results show that there are transition points on the cloud point curve in a very narrow range of concentration of surfactant AOT. The transition points were changed with the temperature and water concentration. These phenomena show that lower temperature is suitable to forming microemulsion droplet and the microemulsion with high water concentration is likely to absorb more surfactants to structure the interface.

  4. Fracture healing and transport properties of wellbore cement in the presence of supercritical CO2

    NARCIS (Netherlands)

    Liteanu, E.; Spiers, C.J.

    2011-01-01

    This paper investigates the process and rate of carbonation reaction of Class A wellbore cement exposed to CO2-saturated solution at confined conditions similar to those employed in geological storage of CO2. The main goal was to investigate whether reaction improves or degrades the sealing/healing

  5. Economic Assessment of Supercritical CO2 Extraction of Waxes as Part of a Maize Stover Biorefinery

    Directory of Open Access Journals (Sweden)

    Thomas M. Attard

    2015-07-01

    Full Text Available To date limited work has focused on assessing the economic viability of scCO2 extraction to obtain waxes as part of a biorefinery. This work estimates the economic costs for wax extraction from maize stover. The cost of manufacture (COM for maize stover wax extraction was found to be €88.89 per kg of wax, with the fixed capital investment (FCI and utility costs (CUT contributing significantly to the COM. However, this value is based solely on scCO2 extraction of waxes and does not take into account the downstream processing of the biomass following extraction. The cost of extracting wax from maize stover can be reduced by utilizing pelletized leaves and combusting the residual biomass to generate electricity. This would lead to an overall cost of €10.87 per kg of wax (based on 27% combustion efficiency for electricity generation and €4.56 per kg of wax (based on 43% combustion efficiency for electricity generation. A sensitivity analysis study showed that utility costs (cost of electricity had the greatest effect on the COM.

  6. High-pressure Phase Equilibria for Binary Ethanol System Containing Supercritical CO2

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    High-pressure phase behavior of supercritical (SC) CO2+ethanol system was investigated at 333.2 K, 348.2 K, 353.2 K, 368.2 K, 413.2 K and 453.2 K and pressure from 2.0 MPa to 14.3 MPa. The measurement was carried out in a cylindrical autoclave with a moveable piston and a window for adjustment and observation of phase equilibria at given T and p. The samples were taken from two coexisting phases and were analyzed to obtain their compositions. It is shown that the solubility of SC CO2 in ethanol increases drastically with pressures at the given temperature, but the content of ethanol in CO2-rich phase increase faintly.

  7. Inhibitory effect of monogalactosyldiacylglycerol, extracted from spinach using supercritical CO2, on mammalian DNA polymerase activity.

    Science.gov (United States)

    Iijima, Hiroshi; Musumi, Keiichi; Hada, Takahiko; Maeda, Naoki; Yonezawa, Yuko; Yoshida, Hiromi; Mizushina, Yoshiyuki

    2006-03-08

    We investigated the effective extraction of monogalactosyldiacylglycerol (MGDG) from dried spinach (Spinacia oleracea) using supercritical fluid carbon dioxide (SC-CO(2)) with a modifier/entrainer. The yield of MGDG in the SC-CO(2) extract was not influenced by increasing temperature at a constant pressure, although the total extract yield was decreased. The total extract yield and MGDG yield in the extract from commercially purchased spinach (unknown subspecies), were greatly influenced by lower pressure. In a modifier (i.e., ethanol) concentration range of 2.5-20%, both the extract and MGDG yield increased as the ethanol concentration rose. The highest total extract yield (69.5 mg/g of spinach) and a good MGDG yield (16.3 mg/g of spinach) were obtained at 80 degrees C, 25 MPa, and 20% ethanol. The highest MGDG concentration (76.0% in the extract) was obtained at 80 degrees C, 25 MPa, and 2.5% ethanol, although the total extract yield under these conditions was low (5.2 mg/g of spinach). The optimal conditions for the extraction of MGDG were 80 degrees C, 20 MPa, and 10% ethanol. Of the 11 subspecies of spinach tested under these conditions, "Ujyou" had the highest concentration of MGDG. The total extract yield and MGDG concentration of Ujyou were 20.4 mg of the extract/g of spinach and 70.5%, respectively. The concentration of MGDG was higher in the SC-CO(2) extract than in the extract obtained using solvents such as methanol and n-hexane. The extract of Ujyou, which was the optimal subspecies for the extraction of MGDG, inhibited the activity of calf DNA polymerase alpha with IC(50) values of 145 microg/mL but was not effective against DNA polymerase beta.

  8. Micronization, characterization and in-vitro dissolution of shellac from PGSS supercritical CO2 technique

    CSIR Research Space (South Africa)

    Labuschagne, Philip W

    2016-02-01

    Full Text Available and temperature. In addition, it was possible to produce shellac microparticles ranging in average diameter from 180 to 300µm. It was also shown that processing shellac in sc-CO2 resulted in accelerated esterification reactions, potentially limiting the extent...

  9. Swelling kinetics and impregnation of PLA with thymol under supercritical CO2 conditions

    Directory of Open Access Journals (Sweden)

    Milovanović Stoja L.

    2016-01-01

    Full Text Available The present work was aimed to study swelling kinetics of polylactic acid (PLA and its impregnation with thymol in supercritical carbon dioxide (scCO2 medium. The influences of temperature and soaking time on the swelling kinetics and impregnation yield of PLA cylindrical disc and film were investigated. Swelling experiments were performed in a high pressure view cell at 10 MPa and temperatures of 40°C, 60°C and 75°C for 2 to 24 h. On the basis of swelling kinetics, pressure of 10 MPa and temperature of 40°C were chosen for supercritical solvent impregnation (SSI of the PLA samples during 2 to24 h. The highest swelling extent was observed for the PLA monolith after 24 h treatment with pure scCO2 (7.5% and scCO2 with thymol (118.3%. It was shown that sufficiently high amount of thymol can be loaded into both PLA monolith and film using SSI after only 2 h (10.0% and 6.6%, respectively. Monolith and film of PLA impregnated with thymol could be suitable for active food packaging and sterile medical disposables.

  10. Experimental study on supercritical CO2 adsorption on coals from Upper Silesian coal Basin

    Science.gov (United States)

    Weishauptová, Zuzana; Přibyl, Oldřich; Sýkorová, Ivana

    2014-05-01

    Although coal seams, besides saline aquifers and depleted oil and gas reservoirs, have the lowest capacity for deposition of carbon dioxide yet this relatively new technology is considered advantageous from an economical standpoint, especially in the case of location of a repository in the vicinity of a power plant producing carbon dioxide. Another appreciable positive aspect is injection of carbon dioxide into unmineable methane-bearing seams, which simultaneously increases production of coal methane as a valuable energetic resource. Suitability of coal seams as carbon dioxide repositories is given by exceptional properties of coal, which during the coalification process retained in its interior spatial arrangement a substantial part of the porous structure of the original plant material with predominance of cavities of an effective size coal porous system. The effectivity of the sorption process depends on properties of the coal matter, seam environment, and carbon dioxide under the conditions corresponding to the situation in situ. Among the basic parameters for selection of a suitable repository based on simulation of the deposition process there is determination of its sorption capacity. The capacity can be determined in a laboratory by measuring the amount of carbon dioxide captured in a coal sample at a pressure and temperature corresponding to supercritical conditions in situ using high pressure sorption techniques. Similarly, the amount of methane bound in coal is based on high pressure measurement of it sorbed amount The present study has been aimed at investigation of the effect of the coal properties on the carbon dioxide and methane sorption capacities. High pressure sorption experiments with carbon dioxide and methane were carried out at the temperature 45 oC and the pressure up to 15 MPa with three samples of methane-bearing, medium rank coals in a moisture equilibrated state using a manometric method. The samples were taken from selected positions of drill cores from exploration boreholes in the Bohemian part of the Upper Silesian Basin, and were characterized by a narrow range of the degree of coalification and extremely different petrographic composition. A positive correlation has been found between the equilibrium moisture in the coal samples and the total abundance of oxygen functional groups determined by FTIR. The experimental isotherm data were fitted partly by the modified Langmuir sorption isotherm, partly by the modified Dubinin-Radushkevich sorption isotherm. The calculated values of sorption capacities were compared. After recalculation to the mineral-matter free basis, a positive trend has been observed in the studied samples in the dependence of the sorption capacity on the micropore volume, as well as a positive trend in the dependence on percentage of vitrinite and collotelinite, which forms a major part of vitrinite. On the contrary, a negative trend has been found in the dependence on inertinite percentage.

  11. Biocompatibility of supercritical CO2-treated titanium implants in a rat model.

    Science.gov (United States)

    Hill, C M; Kang, Q K; Wahl, C; Jimenez, A; Laberge, M; Drews, M; Matthews, M A; An, Y H

    2006-04-01

    Supercritical phase CO2 is a promising method for sterilizing implantable devices and tissue grafts. The goal of this study is to evaluate the biocompatibility of titanium implants sterilized by supercritical phase CO2 in a rat subcutaneous implantation model. At 5 weeks post implantation titanium implants sterilized by supercritical phase CO2 produce a soft tissue reaction that is comparable to other methods of sterilization (steam autoclave, ultraviolet light radiation, ethylene oxide gas, and radio-frequency glow-discharge), as indicated by the thickness and density of the foreign body capsule, although there were some differences on the capillary density. Overall the soft tissue response to the implants was similar among all methods of sterilization, indicating supercritical phase CO2 treatment did not compromise the biocompatibility of the titanium implant.

  12. Supercritical CO2 interpolymer complex encapsulation improves heat stability of probiotic bifidobacteria.

    Science.gov (United States)

    Thantsha, M S; Labuschagne, P W; Mamvura, C I

    2014-02-01

    The probiotic industry faces the challenge of retention of probiotic culture viability as numbers of these cells within their products inevitably decrease over time. In order to retain probiotic viability levels above the therapeutic minimum over the duration of the product's shelf life, various methods have been employed, among which encapsulation has received much interest. In line with exploitation of encapsulation for protection of probiotics against adverse conditions, we have previously encapsulated bifidobacteria in poly-(vinylpyrrolidone)-poly-(vinylacetate-co-crotonic acid) (PVP:PVAc-CA) interpolymer complex microparticles under supercritical conditions. The microparticles produced had suitable characteristics for food applications and also protected the bacteria in simulated gastrointestinal fluids. The current study reports on accelerated shelf life studies of PVP:PVAc-CA encapsulated Bifidobacterium lactis Bb12 and Bifidobacterium longum Bb46. Samples were stored as free powders in glass vials at 30 °C for 12 weeks and then analysed for viable counts and water activity levels weekly or fortnightly. Water activities of the samples were within the range of 0.25-0.43, with an average a(w) = 0.34, throughout the storage period. PVP:PVAc-CA interpolymer complex encapsulation retained viable levels above the recommended minimum for 10 and 12 weeks, for B. longum Bb46 and B. lactis Bb12, respectively, thereby extending their shelf lives under high storage temperature by between 4 and 7 weeks. These results reveal the possibility for manufacture of encapsulated probiotic powders with increased stability at ambient temperatures. This would potentially allow the supply of a stable probiotic formulation to impoverished communities without proper storage facilities recommended for most of the currently available commercial probiotic products.

  13. Supercritical CO2 generation of nanometric structure from Ocimum basilicum mucilage prepared for pharmaceutical applications.

    Science.gov (United States)

    Akbari, Iman; Ghoreishi, Seyyed M; Habibi, Neda

    2015-04-01

    Plant-derived polymers are widely used in the pharmaceutical industry due to their emollient, lack of toxicity, and irritating nature and low cost. In this work, basil seed mucilage was dried using supercritical carbon dioxide phase inversion technique to form a nanometric structure. The obtained polymeric structures were characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) method, and Fourier transform infrared spectroscopy (FTIR) and compared with the oven-derived sample group. It was demonstrated that the product morphology could be controlled by altering the composition of methanol which functioned as the co-solvent in the nonsolvent stream. The most homogeneous product (60-nm mean pore size diameter, 78 m(2)/g BET surface area with no agglomeration) was obtained with 2.5% methanol. The FTIR data showed that the presence of hydroxyl and carboxyl groups suggested the bioadhesive property of basil seed mucilage was good and many active pharmaceutical compounds might be loaded to the resultant nanometric structure to enhance drug release. Furthermore, the FTIR analyses indicated that the nature of the final product did not change during the supercritical drying procedure.

  14. Kinetics of the extraction of pumpkin seed oil (Cucurbita pepo L by supercritical CO2

    Directory of Open Access Journals (Sweden)

    Sovilj Milan N.

    2005-01-01

    Full Text Available This paper deals with the supercritical carbon dioxide extraction of pumpkin seed oil (Cucurbita pepo L. Supercritical fluid extraction (SFE has been used to obtain total lipid extracts from other oilseeds, and it has also proved successful in the isolation and enrichment of sterols from oilseeds. The SFE of pumpkin seed oil on a laboratory scale was investigated in thus paper, with special interest in the influence of the extraction pressure on the overall yield of pumpkin seed oil. Extractions were carried out at the pressures of 15, 25 and 30 MPa and at 313 K, and at a pressure of 30 MPa and the temperatures 313, 323, and 333 K. The yield of the extractions conducted at 15 MPa was rather low, 0.1814 g oil per 1g of seed feed (18.4% for an extraction time of 14 h. However, extractions at higher pressures yielded greater quantities of the oil; at 22.5 MPa for 9 h, 36.3% of the oil and at 30 MPa for 6 h, 41.0% of the oil. For comparison, hexane extraction of the seed material yielded less than 40% of the oil. Temperature did not influence the extraction yield. At a pressure of 30 MPa, the color of the fractions yielded during successive extraction time intervals varied greatly, from pail yellow (the first 2 h, through orange-yellow (from 2-4 h to red (after 4 h. The experimental results of the oil yields were compared with the data obtained by the mathematical model of Hong et al., presented in the literature.

  15. Evaluation of the composition of Carica papaya L. seed oil extracted with supercritical CO2

    Directory of Open Access Journals (Sweden)

    Pedro T.W. Barroso

    2016-09-01

    Full Text Available Among the most important tropical fruit grown in the world today and in Brazil, papaya occupies a prominent place. Native to tropical America, papaya has spread to several regions of the world, and Brazil accounts for 12.74% of the world production, followed by Mexico, Nigeria and India. The culture reached a harvested area of 441,042 ha and production of 12,420,585 t worldwide. The largest interest in this fruit relies on its main constituent compounds, like vitamins A, B and C, alkaloids (carpaine and pseudocarpaine, proteolytic enzymes (papain and quimiopapain and benzyl isothiocyanate, more known as BITC, which has anthelmintic activity. Because of that, the present work has as objective the evaluation of the efficiency and composition of the oil extracted from Carica papaya L. seeds with supercritical carbon dioxide. The experiments were performed in a unit containing mainly a high-pressure pump and a stainless steel extractor with 42 mL of volume. The sampling was performed at each 20 min until the saturation of the process. About 6.5 g of sample were fed for each experiment done at 40, 60 and 80 °C under the pressures of 100, 150 and 200 bar. Samples of the Carica papaya L. fruit were acquired in a popular market and free for personal use intended for the study. After collection, the seeds were crushed with the help of a pestle, and dried at 60 °C for 60 min. For each operational condition, the extraction curves were constructed relating cumulative mass of oil extracted in function of the operational time. The better efficiencies were found at 40 °C and 200 bar (1.33% followed by 80 °C and 200 bar (2.56%. Gas chromatography and NMR analysis could identify an insecticide component (BITC that enables new applications of this residue in pharmaceutical and chemical industries.

  16. Preparation of Porous Biodegradable Polymer and Its Nanocomposites by Supercritical CO2 Foaming for Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Xia Liao

    2012-01-01

    Full Text Available Using supercritical carbon dioxide (scCO2 as an alternative to conventional methods in the preparation of porous biodegradable polymer and polymer/nanocomposites for tissue engineering has attracted increasing interest in recent years due to the absence of using organic solvents and the ability to incorporate thermosensitive biologicals without loss of bioactivity. Additionally, scCO2 can exert a high level of control over porosity and morphology of scaffolds by tuning the processing parameters. This paper describes the newly achievements on the preparation of porous polymer materials using scCO2 foaming technology with focus on the porous biodegradable materials and its nanocomposites relevant to tissue engineering.

  17. Economic Assessment of Supercritical CO2 Extraction of Waxes as Part of a Maize Stover Biorefinery

    Science.gov (United States)

    Attard, Thomas M.; McElroy, Con Robert; Hunt, Andrew J.

    2015-01-01

    To date limited work has focused on assessing the economic viability of scCO2 extraction to obtain waxes as part of a biorefinery. This work estimates the economic costs for wax extraction from maize stover. The cost of manufacture (COM) for maize stover wax extraction was found to be €88.89 per kg of wax, with the fixed capital investment (FCI) and utility costs (CUT) contributing significantly to the COM. However, this value is based solely on scCO2 extraction of waxes and does not take into account the downstream processing of the biomass following extraction. The cost of extracting wax from maize stover can be reduced by utilizing pelletized leaves and combusting the residual biomass to generate electricity. This would lead to an overall cost of €10.87 per kg of wax (based on 27% combustion efficiency for electricity generation) and €4.56 per kg of wax (based on 43% combustion efficiency for electricity generation). A sensitivity analysis study showed that utility costs (cost of electricity) had the greatest effect on the COM. PMID:26263976

  18. Amphiphilic conetworks as activating carriers for the enhancement of enzymatic activity in supercritical CO2.

    Science.gov (United States)

    Bruns, Nico; Bannwarth, Willi; Tiller, Joerg C

    2008-09-01

    Enzymatic reactions in supercritical carbon dioxide (scCO2) represent a way of combining the advantages of biocatalysis with the environmental benign nature of scCO2 as a solvent. Here we demonstrate that activities of enzymes in scCO2 can be greatly enhanced by incorporating them into amphiphilic conetworks (APCNs), a novel type of enzyme support. Two sets of hydrophilic/scCO2-philic APCNs, poly(2-hydroxyethyl acrylate)-linked by-poly(dimethylsiloxane) (PHEA-l-PDMS) and poly(2-hydroxyethyl acrylate)-linked by-perfluoropolyether (PHEA-l-PFPE), were prepared and loaded with the synthetically relevant lipase from Rhizomucor miehei. The effect of the APCNs' composition on the amount of the absorbed lipase was studied. It is observed that both sets of lipase-loaded APCNs enhance the catalytic activity of the enzyme in scCO2. The chemical nature of the scCO2-philic phase as well as the conetworkscomposition greatly influences the activity of the lipase in the conetworks. Activities obtained with PFPE-basedAPCNS were up to 10-fold higher than those obtained with PDMS-based conetworks. The highest specific activity measured corresponds to a 2,000-fold activation compared to the lyophilized enzyme powder. This activity is 10 times higher than the specific activity of the lipase immobilized on an optimized commercial carrier.

  19. Optimization of Supercritical CO2 Extraction of Fish Oil from Viscera of African Catfish (Clarias gariepinus

    Directory of Open Access Journals (Sweden)

    Mohamed Zaidul Islam Sarker

    2012-09-01

    Full Text Available Fish oil was extracted from the viscera of African Catfish using supercritical carbon dioxide (SC-CO2. A Central Composite Design of Response Surface methodology (RSM was employed to optimize the SC-CO2 extraction parameters. The oil yield (Y as response variable was executed against the four independent variables, namely pressure, temperature, flow rate and soaking time. The oil yield varied with the linear, quadratic and interaction of pressure, temperature, flow rate and soaking time. Optimum points were observed within the variables of temperature from 35 °C to 80 °C, pressure from 10 MPa to 40 MPa, flow rate from 1 mL/min to 3 mL/min and soaking time from 1 h to 4 h. However, the extraction parameters were found to be optimized at temperature 57.5 °C, pressure 40 MPa, flow rate 2.0 mL/min and soaking time 2.5 h. At this optimized condition, the highest oil yields were found to be 67.0% (g oil/100 g sample on dry basis in the viscera of catfish which was reasonable to the yields of 78.0% extracted using the Soxhlet method.

  20. Supercritical CO(2) extraction of beta-carotene and lycopene from tomato paste waste.

    Science.gov (United States)

    Baysal, T; Ersus, S; Starmans, D A

    2000-11-01

    Lycopene and beta-carotene were extracted from tomato paste waste using supercritical carbon dioxide (SC-CO(2)). To optimize supercritical fluid extraction (SFE) results for the isolation of lycopene and beta-carotene, a factorial designed experiment was conducted. The factors assessed were the temperature of the extractor (35, 45, 55, and 65 degrees C), the pressure of the extraction fluid (200, 250, and 300 bar), addition of cosolvent (5, 10, and 15% ethanol), extraction time (1, 2, and 3 h), and CO(2) flow rate (2, 4, and 8 kg/h). The total amounts of lycopene and beta-carotene in the tomato paste waste, extracts, and residues were determined by HPLC. A maximum of 53.93% of lycopene was extracted by SC-CO(2) in 2 h (CO(2) flow rate = 4 kg/h) at 55 degrees C and 300 bar, with the addition of 5% ethanol as a cosolvent. Half of the initially present beta-carotene was extracted in 2 h (flow rate = 4 kg/h), at 65 degrees C and 300 bar, also with the addition of 5% ethanol.

  1. Grafting poly ethylene glycol chains for antifouling purposes using supercritical CO2

    DEFF Research Database (Denmark)

    Lokanathan, Arcot R.

    2011-01-01

    Poly (ethylene glycol) (PEG) brushes are widely used for making antifouling surfaces1. High graft density, which is desirable for optimal antifouling activity can be achieved using techniques such as atom transfer radical polymerisation2 (ATRP), cloud point grafting1, and underbrushes formation...

  2. HYDROGENATION OF 4-OXOISOPHORONE IN SUPERCRITICAL CO2 MEDIUM OVER ALUMINA SUPPORTED PALLADIUM CATALYST

    Science.gov (United States)

    Ketoisophorone or 4-oxoisophorone (2,6,6-trimethyl-cyclohex-2-ene-1,4-dione) is a cyclic enedione of tremendous industrial importance due to its use as a key intermediate in the synthesis of various carotenoids and flavoring agents. The catalytic hydrogenation and enzymatic reduc...

  3. Supercritical CO2-driven,periodic patterning on one-dimensionals carbon nanomaterials

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    One-dimensional carbon nano-materials,in particular carbon nanotubes (CNTs) and carbon nanofibers (CNFs),are of scientific and technological interest due to their satisfactory properties and ability to serve as templates for directed assembly.In this work,linear high density polyethylene (PE) was periodically decorated on CNTs and CNFs using a supercritical carbon dioxide (scCO2)antisolvent-induced polymer epitaxy (SAIPE) method,leading to nano-hybrid shish-kebab (NHSK) structures.The formation mechanism of different morphologies of PE lamellae on CNTs and CNFs has been discussed.Palladium nanoparticles were synthesized and immobilized on the PE/CNF NHSK structure with the assistance of scCO2.The obtained hierarchical nano-hybrid architecture may find applications in microfabrication and other related fields.

  4. Micro-PIV Study of Supercritical CO2-Water Interactions in Porous Micromodels

    Science.gov (United States)

    Kazemifar, Farzan; Blois, Gianluca; Christensen, Kenneth T.

    2015-11-01

    Multiphase flow of immiscible fluids in porous media is encountered in numerous natural systems and engineering applications such as enhanced oil recovery (EOR), and CO2 sequestration among others. Geological sequestration of CO2 in saline aquifers has emerged as a viable option for reducing CO2 emissions, and thus it has been the subject of numerous studies in recent years. A key objective is improving the accuracy of numerical models used for field-scale simulations by incorporation/better representation of the pore-scale flow physics. This necessitates experimental data for developing, testing and validating such models. We have studied drainage and imbibition processes in a homogeneous, two-dimensional porous micromodel with CO2 and water at reservoir-relevant conditions. Microscopic particle image velocimetry (micro-PIV) technique was applied to obtain spatially- and temporally-resolved velocity vector fields in the aqueous phase. The results provide new insight into the flow processes at the pore scale.

  5. PREPARATION OF MACROPOROUS TIO2 BY STARCH MICROSPHERES TEMPLATE WITH ASSISTANCE OF SUPERCRITICAL CO2

    Directory of Open Access Journals (Sweden)

    Lin-Qi Tang

    2009-02-01

    Full Text Available In this work a green route is reported to prepare a TiO2 macroporous network using corn starch microspheres flake as a bio-template. The starch microspheres prepared by emulsion technology were used as a template into which precursor tetrabutyl titanate (TBOT was permeated using supercritical carbon dioxide (scCO2 as a forceful carrier or infiltration media, resulting in the formation of an organic/inorganic hybrid material; then the coated template was gelled and dried during the scCO2-coating and the depressurization processes, followed by removal of the template by calcination at 700°C; finally, TiO2 inverse-opals-like material reversely replicating the starch microspheres template was obtained. Scanning electron microscopy (SEM, nitrogen sorption measurements, and X-ray diffraction (XRD indicated that the products were the inverse replicas from their templates. The obtained TiO2 inverse opals-like material showed a wide dispersion of pore sizes from mesopores to macropores – a few nanometers to several micrometers –with the BET surface area up to 103 m2/g, and a predominantly anatase crystalline phase. In addition, the wall thickness of the macropores varied with tunable pressure for closed cells or open-cell foams. So this facile and environmentally friendly process for the preparation of high-surface area, thermally-stable, metal-oxide catalysts and supports by a starch microsphere templating approach may have widespread potential applications in catalysis, absorbents, photoelectric materials, and so on.

  6. Extraction of citronella (Cymbopogon nardus essential oil using supercritical co2: experimental data and mathematical modeling

    Directory of Open Access Journals (Sweden)

    C. F. Silva

    2011-06-01

    Full Text Available Citronella essential oil has more than eighty components, of which the most important ones are citronellal, geranial and limonene. They are present at high concentrations in the oil and are responsible for the repellent properties of the oil. The oil was extracted using supercritical carbon dioxide due to the high selectivity of the solvent. The operational conditions studied varied from 313.15 to 353.15 K for the temperature and the applied pressures were 6.2, 10.0, 15.0 and 180.0 MPa. Better values of efficiency of the extracted oil were obtained at higher pressure conditions. At constant temperature, the amount of extracted oil increased when the pressure increased, but the opposite occurred when the temperature increased at constant pressure. The composition of the essential oil was complex, although there were several main components in the oil and some waxes were presented in the extracted oils above 10.0 MPa. The results were modeled using a mathematical model in a predictive way, reproducing the extraction curves over the maximum time of the process.

  7. Influence of pressure and time on extraction process using supercritical CO2

    Directory of Open Access Journals (Sweden)

    Mićić V.

    2008-01-01

    Full Text Available The supercritical fluid extraction (SFE by carbon dioxide (CO2 of Salvia officinalis L. was investigated. SFE by CO2 was performed at different pressure (80, 100, 150, 200 and 300 bar and constant temperature of 40ºC (all other extraction conditions, such are flow rate, particle diameter of Salvia officinalis, extraction time were kept constant. The GC-MS method was used for determination of qualitative and quantitative composition of obtained extracts and essential oils.

  8. Evaluation of the composition of Carica papaya L. seed oil extracted with supercritical CO2.

    Science.gov (United States)

    Barroso, Pedro T W; de Carvalho, Pedro P; Rocha, Thiago B; Pessoa, Fernando L P; Azevedo, Debora A; Mendes, Marisa F

    2016-09-01

    Among the most important tropical fruit grown in the world today and in Brazil, papaya occupies a prominent place. Native to tropical America, papaya has spread to several regions of the world, and Brazil accounts for 12.74% of the world production, followed by Mexico, Nigeria and India. The culture reached a harvested area of 441,042 ha and production of 12,420,585 t worldwide. The largest interest in this fruit relies on its main constituent compounds, like vitamins A, B and C, alkaloids (carpaine and pseudocarpaine), proteolytic enzymes (papain and quimiopapain) and benzyl isothiocyanate, more known as BITC, which has anthelmintic activity. Because of that, the present work has as objective the evaluation of the efficiency and composition of the oil extracted from Carica papaya L. seeds with supercritical carbon dioxide. The experiments were performed in a unit containing mainly a high-pressure pump and a stainless steel extractor with 42 mL of volume. The sampling was performed at each 20 min until the saturation of the process. About 6.5 g of sample were fed for each experiment done at 40, 60 and 80 °C under the pressures of 100, 150 and 200 bar. Samples of the Carica papaya L. fruit were acquired in a popular market and free for personal use intended for the study. After collection, the seeds were crushed with the help of a pestle, and dried at 60 °C for 60 min. For each operational condition, the extraction curves were constructed relating cumulative mass of oil extracted in function of the operational time. The better efficiencies were found at 40 °C and 200 bar (1.33%) followed by 80 °C and 200 bar (2.56%). Gas chromatography and NMR analysis could identify an insecticide component (BITC) that enables new applications of this residue in pharmaceutical and chemical industries.

  9. Analysis of Required Supporting Systems for the Supercritical CO(2) Power Conversion System

    Science.gov (United States)

    2007-09-01

    Environmental Protection Agency EPDM Ethylene-Propylene Diene Monomer EPMA Electron Probe Micro-Analysis ETGBR Existing Technology Gas Breeder Reactor FID...second stabilization period before starting the CO2 transfer to see if the initial density would stabilize closer to the values provided by NIST...closed valve at all. Valve sizing methods can be found in Ouderkirk, 2002. Neoprene, nylon, ethylene-propylene diene monomer ( EPDM ), and

  10. Investigations of Localized Corrosion of Stainless Steel after Exposure to Supercritical CO2

    Energy Technology Data Exchange (ETDEWEB)

    M. Ziomek-Moroz; W. O’Connor; S. Bullard

    2012-03-11

    Severe localized corrosion of a 316 stainless steel autoclave occurred during investigating Type H Portland cement stability in 0.16 M CaCl{sub 2} + 0.02 M MgCl{sub 2} + 0.82 M NaCl brine in contact with supercritical CO{sub 2} containing 4% O{sub 2}. The system operated at 85 C and pressure of 29 MPa. However, no corrosion was observed in the same type of autoclave being exposed to the same environment, containing Type H Portland cement cylindrical samples, also operating at pressure of 29 MPa but at 50 C. The operation time for the 85 C autoclave was 53 days (1272 hours) while that for the 50 C autoclave was 66 days (1584 hours). Debris were collected from the base of both autoclaves and analyzed by X-ray diffraction (XRD). Corrosion products were only found in the debris from the 85 C autoclave. The cement samples were analyzed before and after the exposure by X-ray florescence (XRF) methods. Optical microscopy was used to estimate an extent of the 316 stainless steel corrosion degradation.

  11. A facile synthesis of poly(3-octylthiophene)-titanium dioxide nanocomposite particles in supercritical CO2.

    Science.gov (United States)

    Yuvaraj, Haldorai; Woo, Min Hee; Park, Eun Ju; Gal, Yeong-Soon; Lim, Kwon Taek

    2008-09-01

    Poly(3-octylthiophene) (P3OT)-titanium dioxide (TiO2) nanocomposite powder where TiO2 was embedded with homogeneous dispersion was synthesized by in-situ chemical oxidative polymerization of 3-octylthiophene in the presence of TiO2 nanoparticles in supercritical carbon dioxide (scCO2), using ferric chloride as the oxidant. The synthesized materials could be obtained as dry powder upon venting of CO2 after the polymerization. The composites were subsequently characterized by FT-IR spectroscopy, transmission electron microscopy (TEM), X-ray diffraction studies (XRD), thermogravimetric analysis (TGA) and photoluminescence (PL). The incorporation of TiO2 in the composite was endorsed by FT-IR studies. TGA revealed enhanced thermal stability of P3OT/TiO2 nanocomposite compared to 3-octylthiophene. TEM analysis showed that well dispersed TiO2 nanoparticles in the polymer matrix. Photoluminescence quenching increased with increasing TiO2 concentration in the composite.

  12. Development and stability of semisolid preparations based on a supercritical CO2 Arnica extract.

    Science.gov (United States)

    Bilia, Anna Rita; Bergonzi, Maria Camilla; Mazzi, Giovanni; Vincieri, Franco Francesco

    2006-05-03

    Conventional herbal drug preparations (HDP) based on Arnica montana L. have a low content of the active principles, sesquiterpene lactones, which show poor stability and low physical compatibility in semisolid formulations. Recently, an innovative supercritical carbon dioxide (CO2) extract with high sesquiterpene content has been marketed. Development of six semisolid preparations (cetomacrogol, polysorbate 60, polawax, anphyphil, natrosol and sepigel) based on this innovative CO2 extract is discussed. Stability of these preparations was investigated according to ICH guidelines. The evaluation of in vitro release of active constituents was performed using the cell method reported in the European Pharmacopoeia. Preliminary data on in vivo permeation of three selected formulations is demonstrated using the "skin stripping" test, according to the FDA, in healthy subjects. Analysis of sesquiterpene lactones within the extract and in vitro and in vivo studies was performed by RP-HPLC-DAD-MS method. The cetomacrogol showed the best release profile in the in vitro test, while in the in vivo test the best preparation resulted polysorbate 60 and polawax.

  13. Catalytic hydrodechlorination of dioxins over palladium nanoparticles in supercritical CO2 swollen microcellular polymers.

    Science.gov (United States)

    Wu, Ben-Zen; Chen, Hsiang-Yu; Wang, Joanna S; Tan, Chung-Sung; Wai, Chien M; Liao, Weisheng; Chiu, KongHwa

    2012-08-15

    In this study, palladium nanoparticles embedded in monolithic microcellular high density polyethylene supports are synthesized as heterogeneous catalysts for remediation of 1,6-dichlorodibenzo-p-dioxin and 2,8-dichlorodibenzofuran in 200 atm of supercritical carbon dioxide containing 10 atm of hydrogen gas and at 50-90°C. Stepwise removal of chlorine atoms takes place first, followed by saturation of two benzene rings with slower reaction rates. The pseudo first order rate constant of initial hydrodechlorination for 2,8-dichlorodibenzofuran is 4.3 times greater than that for 1,6-dichlorodibenzo-p-dioxin at 78°C. The catalysts are easily separated from products and can be recyclable and reusable without complicated recovery and cleaning procedures.

  14. Vaccinium meridionale Swartz Supercritical CO2 Extraction: Effect of Process Conditions and Scaling Up

    Science.gov (United States)

    López-Padilla, Alexis; Ruiz-Rodriguez, Alejandro; Restrepo Flórez, Claudia Estela; Rivero Barrios, Diana Marsela; Reglero, Guillermo; Fornari, Tiziana

    2016-01-01

    Vaccinium meridionale Swartz (Mortiño or Colombian blueberry) is one of the Vaccinium species abundantly found across the Colombian mountains, which are characterized by high contents of polyphenolic compounds (anthocyanins and flavonoids). The supercritical fluid extraction (SFE) of Vaccinium species has mainly focused on the study of V. myrtillus L. (blueberry). In this work, the SFE of Mortiño fruit from Colombia was studied in a small-scale extraction cell (273 cm3) and different extraction pressures (20 and 30 MPa) and temperatures (313 and 343 K) were investigated. Then, process scaling-up to a larger extraction cell (1350 cm3) was analyzed using well-known semi-empirical engineering approaches. The Broken and Intact Cell (BIC) model was adjusted to represent the kinetic behavior of the low-scale extraction and to simulate the large-scale conditions. Extraction yields obtained were in the range 0.1%–3.2%. Most of the Mortiño solutes are readily accessible and, thus, 92% of the extractable material was recovered in around 30 min. The constant CO2 residence time criterion produced excellent results regarding the small-scale kinetic curve according to the BIC model, and this conclusion was experimentally validated in large-scale kinetic experiments. PMID:28773640

  15. Supercritical CO2 extraction of functional compounds from Spirulina and their biological activity.

    Science.gov (United States)

    K G, Mallikarjun Gouda; K, Udaya Sankar; R, Sarada; G A, Ravishankar

    2015-06-01

    Supercritical carbon dioxide (SCCO2) extraction and fractionation of Spirulina platensis was carried out to obtain functional compounds with antioxidant, antimicrobial and enzyme inhibitory activities. Extraction of SCCO2 was carried out using 200 g of Spirulina powder at 40 ºC under 120 bar pressure with CO2 flow rate of 1.2 kg h(-1). SCCO2 fraction obtained was further treated with hexane and ethyl acetate to identify its components. Individual components were identified by comparing mass spectra of samples with standard data and retention indices (RI) of C5-C20 n-alkanes mixture using the kovat index formula. The phenolic and flavonoid content of the SCCO2 extract was found to be 0.34 ± 0.01 g/100 g and 0.12 ± 0.01 g/100 g respectively. The SCCO2 extract had antioxidant activity with IC50 value of 109.6 ± 3.0 μg mL(-1) for DPPH (2,2-Diphenyl-1-picryl hydrazyl radical), IC50 value of 81.66 ± 2.5 μg mL(-1) for reducing power and IC50 value of 112.70 ± 0.8 μg mL(-1) for hydroxyl radical scavenging activity. Further, antioxidant activity study on oxidative induced DNA damage was analysed to elucidate the positive role of SCCO2 extract. SCCO2 extracts showed high antimicrobial activity against Gram-positive bacteria (Staphylococcus aureus FRI 722 and Bacillus cereus F 4810) compared to that of Gram negative bacteria (Escherichia coli MTCC 108 and Yersinia enterocolitica MTCC 859). The SCCO2 extract exhibited inhibitory activity on both Angiotensin-1 converting enzyme and α-glucosidase with IC50 values of 274 ± 1.0 μg mL(-1) and 307 ± 2.0 μg mL(-1) respectively.

  16. Extraction of Lutein Diesters from Tagetes Erecta using Supercritical CO2 and Liquid Propane.

    Science.gov (United States)

    Skerget, Mojca; Bezjak, Miran; Makovšek, Katja; Knez, Zeljko

    2010-03-01

    The efficiency of high pressure extraction of lutein diesters from marigold (Tagetes erecta) flower petals has been investigated. The solvents used for extraction were supercritical carbon dioxide and liquid propane. Operating parameters were 300 bar and 40, 60 and 80 °C for CO2 and 100, 150, 200 bar and 40 and 60 °C for propane, respectively. The influence of process parameters on the total yield of extraction and content of lutein diesters in the extracts was investigated. The results show, that solvent power of propane for lutein diesters is approximately 3.5 times higher than of CO2. The calculation procedure based on the Fick's second law was applied to determine the diffusivities of lutein diesters during extraction from marigold flower petals for both extraction stages: a constant rate stage followed by a stage of decreasing rate. The mathematical model based on the Fick's second law well described the experimental extraction results.

  17. Vaccinium meridionale Swartz Supercritical CO2 Extraction: Effect of Process Conditions and Scaling Up

    Directory of Open Access Journals (Sweden)

    Alexis López-Padilla

    2016-06-01

    Full Text Available Vaccinium meridionale Swartz (Mortiño or Colombian blueberry is one of the Vaccinium species abundantly found across the Colombian mountains, which are characterized by high contents of polyphenolic compounds (anthocyanins and flavonoids. The supercritical fluid extraction (SFE of Vaccinium species has mainly focused on the study of V. myrtillus L. (blueberry. In this work, the SFE of Mortiño fruit from Colombia was studied in a small-scale extraction cell (273 cm3 and different extraction pressures (20 and 30 MPa and temperatures (313 and 343 K were investigated. Then, process scaling-up to a larger extraction cell (1350 cm3 was analyzed using well-known semi-empirical engineering approaches. The Broken and Intact Cell (BIC model was adjusted to represent the kinetic behavior of the low-scale extraction and to simulate the large-scale conditions. Extraction yields obtained were in the range 0.1%–3.2%. Most of the Mortiño solutes are readily accessible and, thus, 92% of the extractable material was recovered in around 30 min. The constant CO2 residence time criterion produced excellent results regarding the small-scale kinetic curve according to the BIC model, and this conclusion was experimentally validated in large-scale kinetic experiments.

  18. Economic Assessment of Supercritical CO2 Extraction of Waxes as Part of a Maize Stover Biorefinery.

    Science.gov (United States)

    Attard, Thomas M; McElroy, Con Robert; Hunt, Andrew J

    2015-07-31

    To date limited work has focused on assessing the economic viability of scCO2 extraction to obtain waxes as part of a biorefinery. This work estimates the economic costs for wax extraction from maize stover. The cost of manufacture (COM) for maize stover wax extraction was found to be € 88.89 per kg of wax, with the fixed capital investment (FCI) and utility costs (CUT) contributing significantly to the COM. However, this value is based solely on scCO2 extraction of waxes and does not take into account the downstream processing of the biomass following extraction. The cost of extracting wax from maize stover can be reduced by utilizing pelletized leaves and combusting the residual biomass to generate electricity. This would lead to an overall cost of € 10.87 per kg of wax (based on 27% combustion efficiency for electricity generation) and €4.56 per kg of wax (based on 43% combustion efficiency for electricity generation). A sensitivity analysis study showed that utility costs (cost of electricity) had the greatest effect on the COM.

  19. A comparative study of solvent and supercritical CO2 extraction of Simarouba gluaca seed oil

    National Research Council Canada - National Science Library

    B. Anjaneyulu; S. Satyannarayana; Sanjit Kanjilal; V. Siddaiah; K. N. Prasanna Rani

    2017-01-01

    In the present study, the supercritical carbon dioxide (CO2) extraction of oil from Simarouba gluaca seeds was carried out at varying conditions of pressure (300–500 bar), temperature (50–70 °C) and CO2 flow rate (10–30 g·min-1...

  20. Application of supercritical CO2 for extraction of polyisoprenoid alcohols and their esters from plant tissues.

    Science.gov (United States)

    Jozwiak, Adam; Brzozowski, Robert; Bujnowski, Zygmunt; Chojnacki, Tadeusz; Swiezewska, Ewa

    2013-07-01

    In this study, a method of supercritical fluid extraction (SFE) with carbon dioxide of polyisoprenoids from plant photosynthetic tissues is described. SFE was an effective extraction method for short- and medium-chain compounds with even higher yield than that observed for the "classical extraction" method with organic solvents. Moreover, SFE-derived extracts contained lower amounts of impurities (e.g., chlorophylls) than those obtained by extraction of the same tissue with organic solvents. Elevated temperature and extended extraction time of SFE resulted in a higher rate of extraction of long-chain polyisoprenoids. Ethanol cofeeding did not increase the extraction efficiency of polyisoprenoids; instead, it increased the content of impurities in the lipid extract. Optimization of SFE time and temperature gives the opportunity of prefractionation of complex polyisoprenoid mixtures accumulated in plant tissues. Extracts obtained with application of SFE are very stable and free from organic solvents and can further be used directly in experimental diet supplementation or as starting material for preparation of semisynthetic polyisoprenoid derivatives, e.g., polyisoprenoid phosphates.

  1. Comparative study of lipid extraction from microalgae by organic solvent and supercritical CO2.

    Science.gov (United States)

    Cheng, Chen-Hsi; Du, Tz-Bang; Pi, Hsien-Chueh; Jang, Shyue-Ming; Lin, Yun-Huin; Lee, Hom-Ti

    2011-11-01

    Pavlova sp. was employed to evaluate the efficiency of different lipid extraction methods. The microalgal crude lipids content determined using the mixed solvent with ultrasonic method was 44.7 wt.%. The triglyceride content obtained by the mixed solvent method was 15.6 wt.%. The extraction yield was the FAME yield divided by the maximum FAME (15.9 wt.%). The extraction yield was improved by cell disruption prior to extraction, and the highest triglyceride extraction yield of 98.7% was observed using the supercritical fluid extraction (SFE) method with bead-beating. The results indicate that the SFE method is effective and provides higher selectivity for triglyceride extraction though the total lipid extracted was less than that using solvent extraction. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Supercritical CO2-based solvents in next generation micro- electronics processing

    Institute of Scientific and Technical Information of China (English)

    ZHANG XiaoGang; Keith P.JOHNSTON

    2007-01-01

    Large amount of chemicals and highly purified-water are needed in microelectronic manufacture. The ability of solutions to penetrate tiny spaces will become significantly more challenging as the feature size of semiconductor devices decreases to nanoscale dimensions and the functional complexity of integrated circuitries (ICs) ever increases. Supercritical fluids (SCFs) possess a unique combination of properties (no surface tension and gas-like viscosity) that can potentially be exploited for application in microelectronics manufacturing and processing in response to needs for material-compatible cleaning systems, small-dimension developing solvents, and low chemical-use processes. Recent microelectronics processes for cleaning and rinsing of patterned porous low-k dielectrics and drying of photoresist in CO2-based solvents are the main focus of this review. Additional topics in supercritical fluid processing include spin coating of photoresists, development with nanoscale dimensions, metal deposition and silylation.

  3. EVALUATION OF RESERVOIR ROCK AND WELL BORE CEMENT ALTERATION WITH SUPERCRITICAL CO2

    Energy Technology Data Exchange (ETDEWEB)

    William k. O' Connor; Gilbert E Rush

    2009-01-01

    An evaluation of the alteration of reservoir rock and well bore cement at their interface, under supercritical CO{sub 2} (SCCO{sub 2}), was conducted at the laboratory-scale using simulated brine solutions at down-hole conditions. These studies were intended to identify potential leakage pathways for injected CO{sub 2} due to degradation of the well bore. Two distinct test series were conducted on core samples of the Mt. Simon sandstone from the Illinois Basin, IL, and the Grand Ronde basalt from the Pasco Basin, WA. LaFarge Class H well bore cement was used for both series. Reservoir rock/cement cores were immersed within a CO{sub 2}-saturated brine for up to 2000 hours at 35 degrees C and 100 atm CO{sub 2}. Results suggest that the impact of SCCO{sub 2} injection is reservoir-specific, being highly dependent on the reservoir brine and rock type. Brine pH can be significantly altered by CO{sub 2} injection, which in turn can dramatically impact the dissolution characteristics of the reservoir rock. Finally, well bore cement alteration was identified, particularly for fresh cast cement allowed to cure at SCCO{sub 2} conditions. However, this alteration was generally limited to an outer rind of carbonate and Ca-depleted cement which appeared to protect the majority of the cement core from further attack. These studies indicate that at the cement-rock interface, the annular space may be filled by carbonate which could act as an effective barrier against further CO{sub 2} migration along the well bore.

  4. Identification of Fragile Microscopic Structures during Mineral Transformations in Wet Supercritical CO2

    Energy Technology Data Exchange (ETDEWEB)

    Arey, Bruce W.; Kovarik, Libor; Qafoku, Odeta; Wang, Zheming; Hess, Nancy J.; Felmy, Andrew R.

    2013-04-01

    In this study we examine the nature of highly fragile reaction products that form in low water content super critical carbon dioxide (scCO2) using a combination of scanning electron microscopy/focus ion beam (SEM/FIB), confocal Raman spectroscopy, helium ion microscopy (HeIM), and transmission electron microscopy (TEM). HeIM images show these precipitates to be fragile rosettes that can readily decompose even under slight heating from an electron beam. Using the TEM revealed details on the interfacial structure between the newly formed surface precipitates and the underlying initial solid phases. The detailed microscopic analysis revealed that the growth of the precipitates either followed a tip growth mechanism with precipitates forming directly on the forsterite surface if the initial solid was non-porous (natural forsterite) or growth from the surface of the precipitates where fluid was conducted through the porous (nanoforsterite) agglomerates to the growth center. The mechanism of formation of the hydrated/hydroxylated magnesium carbonate compound (HHMC) phases offers insight into the possible mechanisms of carbonate mineral formation from scCO2 solutions which has recently received a great deal of attention as the result of the potential for CO2 to act as an atmospheric greenhouse gas and impact overall global warming. The techniques used here to examine these fragile structures an also be used to examine a wide range of fragile material surfaces. SEM and FIB technologies have now been brought together in a single instrument, which represents a powerful combination for the studies in biological, geological and materials science.

  5. In Situ Infrared Spectroscopic Study of Forsterite Carbonation in Wet Supercritical CO2

    Energy Technology Data Exchange (ETDEWEB)

    Loring, John S.; Thompson, Christopher J.; Wang, Zheming; Joly, Alan G.; Sklarew, Deborah S.; Schaef, Herbert T.; Ilton, Eugene S.; Rosso, Kevin M.; Felmy, Andrew R.

    2011-07-19

    Carbonation reactions are central to the prospect of CO2 trapping by mineralization in geologic reservoirs. In contrast to the relevant aqueous-mediated reactions, little is known about the propensity for carbonation in the long-term partner fluid: water-containing supercritical carbon dioxide (‘wet’ scCO2). We employed in situ mid-infrared spectroscopy to follow the reaction of a model silicate mineral (forsterite, Mg2SiO4) for 24 hr with wet scCO2 at 50°C and 180 atm, using water concentrations corresponding to 0%, 55%, 95%, and 136% saturation. Results show a dramatic dependence of reactivity on water concentration and the presence of liquid water on the forsterite particles. Exposure to neat scCO2 showed no detectable carbonation reaction. At 55% and 95% water saturation, a liquid-like thin water film was detected on the forsterite particles; less than 1% of the forsterite transformed, mostly within the first 3 hours of exposure to the fluid. At 136% saturation, where an (excess) liquid water film approximately several nanometers thick was intentionally condensed on the forsterite, the carbonation reaction proceeded continuously for 24 hr with 10% to 15% transformation. Our collective results suggest constitutive links between water concentration, water film formation, reaction rate and extent, and reaction products in wet scCO2.

  6. Research on Model and Related Parameters of Supercritical CO2 Injection into Depleted Reservoir

    Science.gov (United States)

    Ma, Pinghua; He, Jun

    2017-07-01

    On the basis of the research on CO2 geological storage and enhanced oil recovery(EOR) technology, a random porosity distribution model which conforms to logarithmic normal distribution was adopted in order to describe the heterogeneous characteristics of pore structure. On this basis, the two-phase flow model of CO2-formation water was established to describe the displacement process. Through the simulation of CO2 injection into depleted reservoir, it confirmed that injection point pressure was associated with the temperature and depth of the formation except heterogeneity. But the saturation distribution was greatly influenced by formation heterogeneity and depth. Thus, the space utilization of the injection layer reduced gradually with the depth increasing. The related research is important for CO2 storage, migration and evolution in depleted reservoir.

  7. The influence of water and supercritical CO2 on the failure behavior of chalk

    NARCIS (Netherlands)

    Liteanu, E.; Spiers, C.J.; de Bresser, J.H.P.

    2013-01-01

    Reduction of compressive strength by injection of water into chalk is a well-known mechanism responsible for increased compaction in chalk reservoirs. This raises the question of whether such effects might be enhanced in the context of long-term storage of CO2 or of CO2 injection for enhanced oil

  8. Improved neuroprotective effects by combining Bacopa monnieri and Rosmarinus officinalis supercritical CO2 extracts.

    Science.gov (United States)

    Ramachandran, Cheppail; Quirin, Karl-Werner; Escalon, Enrique; Melnick, Steven J

    2014-04-01

    Ethnobotanical evidence suggests that herbs such as brahmi (Bacopa monnieri) and rosemary (Rosmarinus officinalis) may possess antioxidant and neuroprotective properties. We compared the antioxidant and neuroprotective effects of supercritical extract of Bacopa monnieri and rosemary antioxidant extract obtained from Rosmarinus officinalis as well as their combination to examine the effects on human glial (U-87 MG) and embryonic mouse hypothalamus cells. Bacopa monnieri extract, rosemary antioxidant extract, and their combination (1:1) are not cytotoxic in both glial and embryonic mouse hypothalamus cell lines up to 200 μg/mL concentration. The combination of extracts of Bacopa monnieri + rosemary antioxidant has better antioxidant potential and antilipid peroxidation activity than either agent alone. Although the extract of Bacopa monnieri + rosemary antioxidant showed almost similar inhibition of phospho tau expression as Bacopa monnieri or rosemary antioxidant extract alone, the combination has better inhibitory effect on amyloid precursor protein synthesis and higher brain-derived neurotrophic factor production in hypothalamus cells than single agents. These results suggest that the extract of Bacopa monnieri + rosemary antioxidant is more neuroprotective than Bacopa monnieri or rosemary antioxidant extract.

  9. Supercritical CO(2) extraction of carotenoids from pitanga fruits (Eugenia uniflora L.)

    OpenAIRE

    FILHO, Genival L.; ROSSO, VeridianaV. De; M. Angela A. MEIRELES; ROSA, Paulo T. V.; OLIVEIRA, Alessandra L.; MERCADANTE, Adriana Z.; CABRAL,Fernando A.

    2008-01-01

    Supercritical carbon dioxide (SC-CO(2)) extraction was employed to extract carotenoids from the freeze-dried pulp of pitanga fruits (Eugenia uniflora L.), an exotic fruit, rich in carotenoids and still little explored commercially. The SC-CO(2) extraction was carried out at two temperatures, 40 and 60 degrees C, and seven pressures, 100, 150, 200, 250, 300, 350 and 400 bar. The carotenoids were determined by high-performance liquid chromatography connected to photodiode array and mass spectro...

  10. Supercritical CO2 extraction applied toward the production of a functional beverage from wine

    OpenAIRE

    Ruiz-Rodríguez, Alejandro; Fornari, Tiziana; Jaime, Laura; Vázquez, Erika; Amador, Beatriz; Nieto, Juan Antonio; Reglero, Guillermo

    2012-01-01

    NOTICE: this is the author’s version of a work that was accepted for publication in Journal of Supercritical Fluids . Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in JOURNAL OF SUPERCRITICAL FLUIDS 61 (2012) http://dx.doi.org...

  11. Development of a Novel Catalytic Membrane Reactor for Heterogeneous Catalysis in Supercritical CO2

    Science.gov (United States)

    Islam, Nazrul M.; Chatterjee, Maya; Ikushima, Yutaka; Yokoyama, Toshiro; Kawanami, Hajime

    2010-01-01

    A novel type of high-pressure membrane reactor has been developed for hydrogenation in supercritical carbon dioxide (scCO2). The main objectives of the design of the reactor are the separate feeding of hydrogen and substrate in scCO2 for safe reactions in a continuous flow process, and to reduce the reaction time. By using this new reactor, hydrogenation of cinnamaldehyde into hydrocinnamaldehyde has been successfully carried out with 100% selectivity at 50 °C in 10 MPa (H2: 1 MPa, CO2: 9 MPa) with a flow rate of substrate ranging from 0.05 to 1.0 mL/min. PMID:20162008

  12. Study on Purifying Technology of Andrographolide by Supercritical CO2 Secondary Gradient Crystallization

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wen-cheng; PAN Jian

    2004-01-01

    The effects of the secondary gradient crystallizing pressure, temperature and time on the purity and crystallization ratio of andrographolide were investigated via single factor experiments. The shape of crystal was observed with scanning electron microscopy (SEM). The purity of andrographolide was determined by high pressure liquid chromatography (HPLC). It was found that the optimized parameters were pressure 14 MPa, temperature 55℃,time 60 min, and CO2 flow rate 15 L min-1, under these conditions the particle of andrographolide was much smaller, the crystal of andrographolide was distributed in floccule on crystal board, with the purity of andrographolide 92.5%, the crystallization ratio 48.9%.

  13. Extraction of garlic with supercritical CO2 and conventional organic solvents

    Directory of Open Access Journals (Sweden)

    J. M. del Valle

    2008-09-01

    Full Text Available Garlic (Allium sativum L. and garlic extracts have therapeutical properties that stem from their sulfur-containing compounds, mainly allicin. The main objective of this work was to compare conventional and "premium" garlic extracts in terms of yield and quality, with the latter being obtained using supercritical carbon dioxide (SC-CO2 as the solvent. Yield ranged between 0.65 and 1.0% and increased with extraction pressure (150-400 bar at a constant temperature of 50°C. Extraction temperature (35-60°C, on the other hand, had little effect at a constant pressure of 300 bar. Based on yield and quality considerations, the best extraction conditions using SC-CO2 were 35-50°C and 300-400 bar. A yield of 5.5% was obtained by conventional extraction using ethanol as the solvent, but ethanol appeared to be less selective for valuable components than SC-CO2. The use of fresh garlic resulted in extracts that more closely resembled commercial products, possibly because of thermal and oxidative degradation of valuable microconstituents during drying.

  14. Hydrolases in supercritical CO2 and their use in a high-pressure membrane reactor.

    Science.gov (United States)

    Knez, Z; Habulin, M; Primozic, M

    2003-03-01

    The thermal stability and activity of enzymes in supercritical carbon dioxide (SC CO(2)) and near-critical propane were studied at a pressure of 300 bar in the temperature range 20-90 degrees C. Proteinase from Carica papaya was incubated in microaqueous SC CO(2) at atmospheric pressure in a nonaqueous system. Lipase stability in an aqueous medium at atmospheric pressure and in SC CO(2) as well as near-critical propane at 100 bar and 40 degrees C was studied. In order to investigate the impact of solvent on lipases, these were chosen from different sources: Pseudomonas fluorescences, Rhizpous javanicus, Rhizopus niveus and porcine pancreas. On the basis of our previous study on lipase activities in dense gases, a high-pressure continuous flat-shape membrane reactor was designed. The hydrolysis of sunflower oil in SC CO(2) was performed as a model reaction in this reactor. The reaction was catalyzed by the lipase preparation Lipolase 100T and was performed at 50 degrees C and 200 bar.

  15. Lipase-catalyzed transesterification of soybean oil and phytosterol in supercritical CO2.

    Science.gov (United States)

    Hu, Lizhi; Llibin, Sun; Li, Jun; Qi, Liangjun; Zhang, Xu; Yu, Dianyu; Walid, Elfalleh; Jiang, Lianzhou

    2015-12-01

    The transesterification of phytosterol and soybean oil was performed using Novozym 435 in supercritical carbon dioxide (SC-CO2). The transesterification reaction was conducted in soybean oil containing 5-25% phytosterol at 55-95 °C and free-water solvent. The effects of temperature, reaction time, phytosterol concentration, lipase dosage and reaction pressure on the conversion rate of transesterification were investigated. The optimal reaction conditions were the reaction temperature (85 °C), reaction time (1 h), phytosterol concentration (5%), reaction pressure (8 Mpa) and lipase dosage (1%). The highest conversion rate of 92% could be achieved under the optimum conditions. Compared with the method of lipase-catalyzed transesterification of phytosterol and soybean oil at normal pressure, the transesterification in SC-CO2 reduced significantly the reaction temperature and reaction time.

  16. Impregnation of pet films and PHB granules with curcumin in supercritical CO2

    Directory of Open Access Journals (Sweden)

    L. C. S. Herek

    2006-06-01

    Full Text Available The process of dyeing poly(ethylene terephthalate - PET films at 50, 60 and 65ºC and poly(hydroxybutyrate - PHB granules at 60, 70 and 80ºC using supercritical carbon dioxide (scCO2 as solvent and ethanol as cosolvent was studied by DSC, TGA analysis and measurements of shrinkage to determine the morphological modifications caused by the scCO2 treatment of these materials. A comparison of the effects of annealing both polymers in scCO2 provided evidence that PHB had plasticization activity due to its crystallinity and that PET favored the dyeing process at high pressure when its temperature was raised to close to the Tg value. DSC and TGA measurements were obtained for all the samples. The DSC results showed that there was no significant structural change and the TGA data showed that thermal stability was not affected in the samples analyzed.

  17. Evaluation of a multiple-cycle, recombinant virus, growth competition assay that uses flow cytometry to measure replication efficiency of human immunodeficiency virus type 1 in cell culture.

    Science.gov (United States)

    Dykes, Carrie; Wang, Jiong; Jin, Xia; Planelles, Vicente; An, Dong Sung; Tallo, Amanda; Huang, Yangxin; Wu, Hulin; Demeter, Lisa M

    2006-06-01

    Human immunodeficiency virus type 1 (HIV-1) replication efficiency or fitness, as measured in cell culture, has been postulated to correlate with clinical outcome of HIV infection, although this is still controversial. One limitation is the lack of high-throughput assays that can measure replication efficiency over multiple rounds of replication. We have developed a multiple-cycle growth competition assay to measure HIV-1 replication efficiency that uses flow cytometry to determine the relative proportions of test and reference viruses, each of which expresses a different reporter gene in place of nef. The reporter genes are expressed on the surface of infected cells and are detected by commercially available fluorescence-labeled antibodies. This method is less labor-intensive than those that require isolation and amplification of nucleic acids. The two reporter gene products are detected with similar specificity and sensitivity, and the proportion of infected cells in culture correlates with the amount of viral p24 antigen produced in the culture supernatant. HIV replication efficiencies of six different drug-resistant site-directed mutants were reproducibly quantified and were similar to those obtained with a growth competition assay in which the relative proportion of each variant was measured by sequence analysis, indicating that recombination between the pol and reporter genes was negligible. This assay also reproducibly quantified the relative fitness conferred by protease and reverse transcriptase sequences containing multiple drug resistance mutations, amplified from patient plasma. This flow cytometry-based growth competition assay offers advantages over current assays for HIV replication efficiency and should prove useful for the evaluation of patient samples in clinical trials.

  18. Using a combination of weighting factor method and imperialist competitive algorithm to improve speed and enhance process of reloading pattern optimization of VVER-1000 reactors in transient cycles

    Energy Technology Data Exchange (ETDEWEB)

    Rahmani, Yashar, E-mail: yashar.rahmani@gmail.com [Department of Physics, Faculty of Engineering, Islamic Azad University, Sari Branch, Sari (Iran, Islamic Republic of); Shahvari, Yaser [Department of Computer Engineering, Payame Noor University (PNU), P.O. Box 19395-3697, Tehran (Iran, Islamic Republic of); Kia, Faezeh [Golestan Institute of Higher Education, Gorgan 49139-83635 (Iran, Islamic Republic of)

    2017-03-15

    Highlights: • This article was an attempt to optimize reloading pattern of Bushehr VVER-1000 reactor. • A combination of weighting factor method and the imperialist competitive algorithm was used. • The speed of optimization and desirability of the proposed pattern increased considerably. • To evaluate arrangements, a coupling of WIMSD5-B, CITATION-LDI2 and WERL codes was used. • Results reflected the considerable superiority of the proposed method over direct optimization. - Abstract: In this research, an innovative solution is described which can be used with a combination of the new imperialist competitive algorithm and the weighting factor method to improve speed and increase globality of search in reloading pattern optimization of VVER-1000 reactors in transient cycles and even obtain more desirable results than conventional direct method. In this regard, to reduce the scope of the assumed searchable arrangements, first using the weighting factor method and based on values of these coefficients in each of the 16 types of loadable fuel assemblies in the second cycle, the fuel assemblies were classified in more limited groups. In consequence, the types of fuel assemblies were reduced from 16 to 6 and consequently the number of possible arrangements was reduced considerably. Afterwards, in the first phase of optimization the imperialist competitive algorithm was used to propose an optimum reloading pattern with 6 groups. In the second phase, the algorithm was reused for finding desirable placement of the subset assemblies of each group in the optimum arrangement obtained from the previous phase, and thus the retransformation of the optimum arrangement takes place from the virtual 6-group mode to the real mode with 16 fuel types. In this research, the optimization process was conducted in two states. In the first state, it was tried to obtain an arrangement with the maximum effective multiplication factor and the smallest maximum power peaking factor. In

  19. Are integrated coal gasification combined-cycle power plants competitive?; Sind Kombi-Kraftwerke mit integrierter Kohlevergasung wettbewerbsfaehig?

    Energy Technology Data Exchange (ETDEWEB)

    Pruschek, R. [Essen Univ. (Gesamthochschule) (Germany); Haupt, G.; Zimmermann, G. [Siemens AG Energieerzeugung KWU, Erlangen (Germany); Ullrich, N. [Krupp Uhde GmbH, Dortmund (Germany)

    1999-08-01

    From investigations into improvements that are feasible already today for integrated coal gasification combined-cycle power plants net plant efficiencies of 51.5% (with reference to the calorifica value), not considering the calorific value of the separated elemental sulfur. Specific investment costs (plant supply price) have been determined with US-dollars 1100/kW. With the given market conditions, assumptions and investigation results the IGCC power plant is in a position to compete with a modern hard coal-fired steam power plant. Detailed investigations show a further efficiency potential of about 56% under consideration of future developments. With SOFC fuel cells upstream of the plant a further increase is conceivable. (orig.) [Deutsch] Aus Untersuchungen von bereits heute durchfuehrbaren Verbesserungen bei Kombi-Kraftwerken mit integrierter Kohlevergasung errechnet sich ein Netto-Anlagenwirkungsgrad von 51,5% (auf den Heizwert bezogen). Dabei ist der Heizwert des in der Entschwefelungsanlage abgetrennten elementaren Schwefels nicht beruecksichtigt. Die spezifische Investition (Anlagenlieferpreis) wurde zu US-Dollar 1100/kW ermittelt. Unter den beschriebenen Marktbedingungen, Annahmen und Untersuchungsergebnissen kann das IGCC-Kraftwerk bei einer Ausnutzungsdauer von 7000 h/a mit einem modernen Steinkohle-Dampfkraftwerk konkurrieren. Detaillierte Untersuchungen zeigen unter Einbeziehung zukuenftiger Entwicklungsschritte ein weiteres Wirkungsgradpotential bis etwa 56%. Mit SOFC-Brennstoffzellen als Vorschaltstufe ist eine weitere Erhoehung denkbar. (orig.)

  20. Optimization of Organic Rankine Cycles for Off-Shore Applications

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Larsen, Ulrik; Nguyen, Tuong-Van

    2013-01-01

    In off-shore oil and gas platform efficiency, the reliability and fuel flexibility are the major concerns when selecting the gas turbine to support the electrical and mechanical demand on the platform. In order to fulfill these requirements, turbine inlet temperature and pressure ratio are not in......, cyclohexane at 55.5 bar is the preferable working fluid with a combined thermal efficiency of 44.3%. The supercritical CO2 cycle with a maximum pressure of 192.9 bar is found to be the best alternative if an extremely low hazard is required....... are not increased up to the optimal values and one or more redundant gas turbines may be employed. With increasing incentives for reducing the CO2 emissions off-shore, improving the thermal efficiency has become a focus area. Due to the peculiar low turbine outlet temperature and due to space and weight constraints...... characteristics of the fluids, e.g. stability, environmental and human health impacts, and safety issues. Both supercritical and subcritical ORCs are included in the analysis. The optimization procedure is first applied to a conservative ORC where the maximum pressure is limited to 20 bar. Subsequently...

  1. Use of Multiple Reheat Helium Brayton Cycles to Eliminate the Intermediate Heat Transfer Loop for Advanced Loop Type SFRs

    Energy Technology Data Exchange (ETDEWEB)

    Haihua Zhao; Hongbin Zhang; Samuel E. Bays

    2009-05-01

    The sodium intermediate heat transfer loop is used in existing sodium cooled fast reactor (SFR) plant design as a necessary safety measure to separate the radioactive primary loop sodium from the water of the steam Rankine power cycle. However, the intermediate heat transfer loop significantly increases the SFR plant cost and decreases the plant reliability due to the relatively high possibility of sodium leakage. A previous study shows that helium Brayton cycles with multiple reheat and intercooling for SFRs with reactor outlet temperature in the range of 510°C to 650°C can achieve thermal efficiencies comparable to or higher than steam cycles or recently proposed supercritical CO2 cycles. Use of inert helium as the power conversion working fluid provides major advantages over steam or CO2 by removing the requirement for safety systems to prevent and mitigate the sodium-water or sodium-CO2 reactions. A helium Brayton cycle power conversion system therefore makes the elimination of the intermediate heat transfer loop possible. This paper presents a pre-conceptual design of multiple reheat helium Brayton cycle for an advanced loop type SFR. This design widely refers the new horizontal shaft distributed PBMR helium power conversion design features. For a loop type SFR with reactor outlet temperature 550°C, the design achieves 42.4% thermal efficiency with favorable power density comparing with high temperature gas cooled reactors.

  2. On Endogenous Competitive Business Cycles

    Science.gov (United States)

    1984-01-01

    generations model by Azariadis and Balasko [19^^31, and Stiglitz [1983]. The effects of a variation of the money supply through Government... Azariadis (19^1] and D. Cass and K. Shell [198I, 1983]. Independently of the present work, a forthcoming paper by C. Azariadis and R. Guesnerie...perfect foresight. See e.g., Azariadis [19^^11, Cass [1980] , Benhabib and Day [1982], Gale [19T3]. The same sort of approach has been used in

  3. Effects of an endurance cycling competition on resting serum insulin-like growth factor I (IGF-I) and its binding proteins IGFBP-1 and IGFBP-3

    Science.gov (United States)

    Chicharro, J; Lopez-Calderon, A; Hoyos, J; Martin-Velasco, A; Villa, G; Villanua, M; Lucia, A

    2001-01-01

    Objectives—To determine whether consecutive bouts of intense endurance exercise over a three week period alters serum concentrations of insulin-like growth factor I (IGF-I) and/or its binding proteins. Methods—Seventeen professional cyclists (mean (SEM) VO2MAX, 74.7 (2.1) ml/kg/min; age, 27 (1) years) competing in a three week tour race were selected as subjects. Blood samples were collected at each of the following time points: t0 (control, before the start of competition), t1 (end of first week), and t3 (end of third week). Serum levels of both total and free IGF-I and IGF binding proteins 1 and 3 (IGFBP-1 and IGFBP-3) were measured in each of the samples. Cortisol levels were measured in nine subjects. Results—A significant (p<0.01) increase was found in total IGF-I and IGFBP-1 at both t1 and t3 compared with to (IGF-I: 110.9 (17.7), 186.8 (12.0), 196.9 (14.7) ng/ml at t0, t1, and t3 respectively; IGFBP-1: 54.6 (6.6), 80.6 (8.0), and 89.2 (7.9) ng/ml at t0, t1, and t3 respectively). A significant (p<0.01) decrease was noted in free IGF-I at t3 compared with both to and t1 (t0: 0.9 (0.1) ng/ml; t1: 0.9 (0.1) ng/ml; t3: 0.7 (0.1) ng/ml); in contrast, IGFBP-3 levels remained stable throughout the race. Conclusions—It would appear that the increase in circulating levels of both IGF-I and its binding protein IGFBP-1 is a short term (one week) endocrine adaptation to endurance exercise. After three weeks of training, total IGF-I and IGFBP-1 remained stable, whereas free IGF-I fell below starting levels. Key Words: cycling; insulin-like growth factor; exercise; endurance; binding proteins PMID:11579061

  4. Competitive Intelligence.

    Science.gov (United States)

    Bergeron, Pierrette; Hiller, Christine A.

    2002-01-01

    Reviews the evolution of competitive intelligence since 1994, including terminology and definitions and analytical techniques. Addresses the issue of ethics; explores how information technology supports the competitive intelligence process; and discusses education and training opportunities for competitive intelligence, including core competencies…

  5. Growing TiO2 nanowires on the surface of graphene sheets in supercritical CO2: characterization and photoefficiency

    Science.gov (United States)

    Farhangi, Nasrin; Medina-Gonzalez, Yaocihuatl; Chowdhury, Rajib Roy; Charpentier, Paul A.

    2012-07-01

    Tremendous interest exists towards synthesizing nanoassemblies for dye-sensitized solar cells (DSSCs) using earth-abundant and -friendly materials with green synthetic approaches. In this work, high surface area TiO2 nanowire arrays were grown on the surface of functionalized graphene sheets (FGSs) containing -COOH functionalities acting as a template by using a sol-gel method in the green solvent, supercritical carbon dioxide (scCO2). The effect of scCO2 pressure (1500, 3000 and 5000 psi), temperature (40, 60 and 80 °C), acetic acid/titanium isopropoxide monomer ratios (HAc/TIP = 2, 4 and 6), functionalized graphene sheets (FGSs)/TIP weight ratios (1:20, 1:40 and 1:60 w/w) and solvents (EtOH, hexane) were investigated. Increasing the HAc/TIPweight ratio from 4 to 6 in scCO2 resulted in increasing the TiO2 nanowire diameter from 10 to 40 nm. Raman and high resolution XPS showed the interaction of TiO2 with the -COOH groups on the surface of the graphene sheets, indicating that graphene acted as a template for polycondensation growth. UV-vis diffuse reflectance and photoluminescence spectroscopy showed a reduction in titania’s bandgap and also a significant reduction in electron-hole recombination compared to bare TiO2 nanowires. Photocurrent measurements showed that the TiO2nanowire/graphene composites prepared in scCO2 gave a 5× enhancement in photoefficiency compared to bare TiO2 nanowires.

  6. Preparation of Semi-interpenetrating Polymer Network of Silicon Rubber and Poly(methyl methylacrylate) Using Supercritical CO2

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The heterogeneous free-radical polymerization of methyl methylacrylatc (MMA) and divinylbenzene (DVB) as cross-linker within supercritical carbon dioxide-swollen silicon rubber (SR) has been studied as an approach to preparing semi-interpenetrating polymer network (semi IPN) of SR and poly(methyl methylacrylate) (PMMA). The SR/PMMA semi-IPNs were characterized by scanning electron microscopy (SEM) and dynamic mechanical analyzer (DMA).

  7. Preparation of Semi—interpenetrating Polymer Network of Silicon Rubber and Poly (methyl methylacrylate) Using Supercritical CO2

    Institute of Scientific and Technical Information of China (English)

    ZhiMinLIU; JiaQiuWANG; 等

    2002-01-01

    The heterogeneous free-radical polymerization of methyl methylacrylate(MMA) and divinylbenzene (DVB) as cross-linker within supercritical carbon dioxide-swollen silicon rubber (SR) has been studied as an approach to preparing semi-interpenetrating polymer network (semi-IPN) of SR and poly(methyl methylacrylate)(PMMA). The SR/PMMA semi-IPNs were characterized by scanning electron microscopy(SEM) and dynamic mechanical analyzer (DMA).

  8. Assessment of the spatial distribution in sub- and supercritical CO(2) using the nearest neighbor approach: a molecular dynamics analysis.

    Science.gov (United States)

    Idrissi, A; Vyalov, I; Damay, P; Frolov, A; Oparin, R; Kiselev, M

    2009-12-03

    The nearest neighbor approach was used to characterize the local structure of CO(2) fluid along its coexistence curve (CC) and along the critical isochore (CI). The distributions of the distances, orientations, and interaction energies between a reference CO(2) molecule and its subsequent nearest neighbors were calculated. Our results show that the local structure may be resolved into two components or subshells: one is characterized by small radial fluctuations, the parallel orientation and a dominance of the attractive part of both the electrostatic (EL) and Lennard-Jones (LJ) to the total interaction energy. Conversely, the second subshell is characterized by large radial fluctuations, a perpendicular orientation, and a concomitant increase of the repulsive contribution of the EL interaction and a shift to less attractive character of the LJ contribution. When the temperature increases along the liquid-gas CC, the first subshell undergoes large changes which are characterized by an obvious increase of the radial fluctuations, by an increase of the random character of the orientation distribution except for the first nearest neighbor which maintains its parallel orientation, and by a drastic decrease of the EL interaction contribution to the total interaction energy. When the temperature is close to the critical isochore, the local structure is no longer resolved into two subshells. Starting from the idea that the profile of vibration modes is sensitive to the local structure as revealed from the nearest neighbor approach, the hypothesis that the CO(2) vibration profile may be deconvoluted into two contributions is discussed in a qualitative manner.

  9. Effect of impurities on the corrosion behavior of CO2 transmission pipeline steel in supercritical CO2-water environments.

    Science.gov (United States)

    Choi, Yoon-Seok; Nesic, Srdjan; Young, David

    2010-12-01

    The corrosion property of carbon steel was evaluated using an autoclave under CO(2)-saturated water phase and water-saturated CO(2) phase with impurities (O(2) and SO(2)) at 80 bar CO(2) and 50 °C to simulate the condition of CO(2) transmission pipeline in the carbon capture and storage (CCS) applications. The results showed that the corrosion rate of carbon steel in CO(2)-saturated water was very high and it increased with adding O(2) in the system due to the inhibition effect of O(2) on the formation of protective FeCO(3). It is noteworthy that corrosion took place in the water-saturated CO(2) phase under supercritical condition when no free water is present. The addition of O(2) increased the corrosion rates of carbon steel in water-saturated CO(2) phase. The addition of 0.8 bar SO(2) (1%) in the gas phase dramatically increased the corrosion rate of carbon steel from 0.38 to 5.6 mm/y. This then increased to more than 7 mm/y with addition of both O(2) and SO(2). SO(2) can promote the formation of iron sulfite hydrate (FeSO(3)·3H(2)O) on the steel surface which is less protective than iron carbonate (FeCO(3)), and it is further oxidized to become FeSO(4) and FeOOH when O(2) is present with SO(2) in the CO(2)-rich phase. The corrosion rates of 13Cr steel were very low compared with carbon steel in CO(2)-saturated water environments with O(2), whereas it was as high as carbon steel in a water-saturated CO(2) phase with O(2) and SO(2).

  10. Flexible low-voltage polymer thin-film transistors using supercritical CO2-deposited ZrO2 dielectrics.

    Science.gov (United States)

    Wei, Qingshuo; You, Eunyoung; Hendricks, Nicholas R; Briseno, Alejandro L; Watkins, James J

    2012-05-01

    The fabrication of low-voltage flexible organic thin film transistors using zirconia (ZrO(2)) dielectric layers prepared via supercritical fluid deposition was studied. Continuous, single-phase films of approximately 30 nm thick ZrO(2) were grown on polyimide (PI)/aluminum (Al) substrates at 250 °C via hydrolysis of tetrakis(2,2,6,6-tetramethyl-3,5-heptane-dionato) zirconium in supercritical carbon dioxide. This dielectric layer showed a high areal capacitance of 317 nF cm(-2) at 1 kHz and a low leakage current of 1.8 × 10(-6) A cm(-2) at an applied voltage of -3 V. By using poly(3-hexylthiophene) (P3HT) as a semiconductor, we have fabricated flexible thin film transistors operating at V(DS) = -0.5 V and V(G) in a range from 0.5 V to -4 V, with on/off ratios on the order of 1 × 10(3) and mobility values higher than 0.1 cm(2)/(V s).

  11. Effect of ultrasound pre-treatment of hemp (Cannabis sativa L.) seed on supercritical CO2 extraction of oil.

    Science.gov (United States)

    Da Porto, C; Natolino, A; Decorti, D

    2015-03-01

    Ultrasound pre-treatment of intact hemp seeds without any solvent assistance was carried out for 10, 20 and 40 min prior to SCCO2 extraction at 40 °C, 300 bar and 45 kg CO2/kg feed. Sonication time effect on SC-CO2 extraction was investigated by the extraction kinetics. The maximum extraction yield was estimated to be 24.03 (% w/w) after 10 min of ultrasonic pre-treatment. The fatty acid compositions of the oils extracted by SC-CO2 without and with ultrasound pre-treatments was analyzed using gas chromatography. It was shown that the content of linoleic, α-linolenic and oleic acids (the most abundant unsaturated fatty acids) of the hemp seed oils were not affected significantly by the application of ultrasound. UV spectroscopy indices (K232 and K268) and antiradical capacity were used to follow the quality of oils. Significant were the changes in their antiradical capacity due to ultrasound treatment. A comparison with the oil extracted by Soxhlet was also given.

  12. Effect of ultrasound pre-treatment of hemp (Cannabis sativa L.) seed on supercritical CO2 extraction of oil

    OpenAIRE

    Da Porto, C.; Natolino, A.; Decorti, D.

    2013-01-01

    Ultrasound pre-treatment of intact hemp seeds without any solvent assistance was carried out for 10, 20 and 40 min prior to SCCO2 extraction at 40 °C, 300 bar and 45 kg CO2/kg feed. Sonication time effect on SC-CO2 extraction was investigated by the extraction kinetics. The maximum extraction yield was estimated to be 24.03 (% w/w) after 10 min of ultrasonic pre-treatment. The fatty acid compositions of the oils extracted by SC-CO2 without and with ultrasound pre-treatments was analyzed using...

  13. Direct synthesis of dimethyl carbonate and propylene glycol using potassium bicarbonate as catalyst in supercritical CO2

    National Research Council Canada - National Science Library

    Yicun Wen; Rui Zhang; Yu Cang; Jianchao Zhang; Lixiao Liu; Xuhong Guo; Bin Fan

    2015-01-01

    The improved one-pot synthesis of dimethyl carbonate and propylene glycol from propylene oxide, supercritical carbon dioxide, and methanol with potassium bicarbonate as the catalyst has been reported in this paper...

  14. Direct synthesis of dimethyl carbonate and propylene glycol using potassium bicarbonate as catalyst in supercritical CO2

    Directory of Open Access Journals (Sweden)

    Wen Yicun

    2015-03-01

    Full Text Available The improved one-pot synthesis of dimethyl carbonate and propylene glycol from propylene oxide, supercritical carbon dioxide, and methanol with potassium bicarbonate as the catalyst has been reported in this paper. As far as we know, it is the first time to use potassium bicarbonate only as the catalyst in the production process which is simple and cheap. Satisfactory conversion rate of propylene oxide and yield of the products could be achieved at the optimized conditions with quite a small amount of by-products. Our new method offers an attractive choice for the production of dimethyl carbonate in large-scale industry efficiently and environmental friendly.

  15. Direct synthesis of dimethyl carbonate and propylene glycol using potassium bicarbonate as catalyst in supercritical CO2

    OpenAIRE

    Wen Yicun; Zhang Rui; Cang Yu; Zhang Jianchao; Liu Lixiao; Guo Xuhong; Fan Bin

    2015-01-01

    The improved one-pot synthesis of dimethyl carbonate and propylene glycol from propylene oxide, supercritical carbon dioxide, and methanol with potassium bicarbonate as the catalyst has been reported in this paper. As far as we know, it is the first time to use potassium bicarbonate only as the catalyst in the production process which is simple and cheap. Satisfactory conversion rate of propylene oxide and yield of the products could be achieved at the optimized conditions with quite a small ...

  16. Supercritical CO2-Assisted Spray Drying of Strawberry-Like Gold-Coated Magnetite Nanocomposites in Chitosan Powders for Inhalation

    Directory of Open Access Journals (Sweden)

    Marta C. Silva

    2017-01-01

    Full Text Available Lung cancer is one of the leading causes of death worldwide. Therefore, it is of extreme importance to develop new systems that can deliver anticancer drugs into the site of action when initiating a treatment. Recently, the use of nanotechnology and particle engineering has enabled the development of new drug delivery platforms for pulmonary delivery. In this work, POXylated strawberry-like gold-coated magnetite nanocomposites and ibuprofen (IBP were encapsulated into a chitosan matrix using Supercritical Assisted Spray Drying (SASD. The dry powder formulations showed adequate morphology and aerodynamic performances (fine particle fraction 48%–55% and aerodynamic diameter of 2.6–2.8 µm for deep lung deposition through the pulmonary route. Moreover, the release kinetics of IBP was also investigated showing a faster release of the drug at pH 6.8, the pH of lung cancer. POXylated strawberry-like gold-coated magnetite nanocomposites proved to have suitable sizes for cellular internalization and their fluorescent capabilities enable their future use in in vitro cell based assays. As a proof-of-concept, the reported results show that these nano-in-micro formulations could be potential drug vehicles for pulmonary administration.

  17. Determination of extractability of pine bark using supercritical CO(2) extraction and different solvents: optimization and prediction.

    Science.gov (United States)

    Yesil-Celiktas, Ozlem; Otto, Frank; Gruener, Sabine; Parlar, Harun

    2009-01-28

    Bark from Pinus brutia was extracted with supercritical fluid extraction (SFE), using CO(2), at various extraction conditions both at laboratory and at pilot scale. Optimized parameters were 200 bar, 60 degrees C, and 3% ethanol at a solvent/feed ratio of 30. Additionally, the pine bark was sonicated (1 h at 50 degrees C) by different solvents (n-hexane, dichloromethane, ethyl acetate, and ethanol) to investigate the correlation between the different extraction setups and to obtain information on SFE up-scaling possibilities. Analyzed by HPLC, 7.2% of (-)-catechin was extractable at laboratory scale, and 58.4% (800 bar) and 47.8% (200 bar), both with modifiers, at pilot scale. By sonication with ethanol, 46.8% of (-)-catechin and almost 100% of (-)-epicatechin and (-)-catechin gallate were extracted. Ethyl acetate extract revealed high correlations with the laboratory scale SFE (r = 0.98) and also pilot scale SFE runs at 200 (r = 0.99) and 800 bar (r = 0.98) without modifiers.

  18. Measurement and correlation of supercritical CO2 and ionic liquid systems for design of advanced unit operations

    Institute of Scientific and Technical Information of China (English)

    Hiroshi MACHIDA; Ryosuke TAGUCHI; Yoshiyuki SATO; Louw J.FLORUSSE; Cor J.PETERS; Richard L.SMITH,Jr

    2009-01-01

    Ionic liquids combined with supercritical fluid technology hold great promise as working solvents for developing compact processes. Ionic liquids, which are organic molten salts, typically have extremely low volatility and high functionality, but possess high viscos-ities, surface tensions and low diffusion coefficients, which can limit their applicability. CO2, on the other hand,especially in its supercritical state, is a green solvent that can be used advantageously when combined with the ionic liquid to provide viscosity and surface tension reduction and to promote mass transfer. The solubility of CO2 in the ionic liquid is key to estimating the important physical properties that include partition coefficients, viscosities,densities, interfacial tensions, thermal conductivities and heat capacities needed in contactor design. In this work, we examine a subset of available high pressure pure component ionic liquid PVT data and high pressure CO2-ionic liquid solubility data and report new correlations for CO2-ionic liquid systems with equations of state that have some industrial applications including: (1) general, (2) fuel desulfurization, (3) CO2 capture, and (4) chiral separation.New measurements of solubility data for the CO2 and 1-butyl-3-methylimidazolium octyl sulfate, [bmim][OcSO4] system are reported and correlated. In the correlation of the CO2 ionic liquid phase behavior, the Peng-Robinson and the Sanchez-Lacombe equations of state were considered and are compared. It is shown that excellent correlation of CO2 solubility can be obtained with either equation and they share some common characteristics regarding inter-action parameters. In the Sanchez-Lacombe equation,parameters that are derived from the supercritical region were found to be important for obtaining good correlation of the CO2-ionic liquid solubility data.

  19. Synthesis of siliceous hollow spheres with large mesopore wall structure by supercritical CO2-in-water interface templating.

    Science.gov (United States)

    Wang, Jiawei; Xia, Yongde; Wang, Wenxin; Mokaya, Robert; Poliakoff, Martyn

    2005-01-14

    Hollow silica spheres with large mesopore wall structures have been synthesized via CO(2)-in-water emulsion templating in the presence of PEO-PPO-PEO block copolymers under supercritical fluid conditions.

  20. Novel polymer composites from waste ethylene-propylene-diene-monomer rubber by supercritical CO2 foaming technology.

    Science.gov (United States)

    Jeong, Keuk Min; Hong, Yeo Joo; Saha, Prosenjit; Park, Seong Ho; Kim, Jin Kuk

    2014-11-01

    In this study, a composite has been prepared by mixing waste rubber, such as ethylene-propylene-diene-monomer and low-density poly ethylene foaming, with supercritical carbon dioxide. In order to optimise the foaming process of the waste ethylene-propylene-diene-monomer-low-density poly ethylene composite, the variations of pressure and temperature on the foamed Microcell formation were studied. As indicated in scanning electron microscope photographs, the most uniform microcellular pattern was found at 200 bar and 100 °C using 30% by weight of waste ethylene-propylene-diene-monomer. Carbon dioxide could not be dissolved uniformly during foaming owing to extensive cross-linking of the waste ethylene-propylene-diene-monomer used for the composite. As a result the presence of un-uniform microcells after foaming were observed in the composite matrix to impart inferior mechanical properties of the composite. This problem was solved with uniform foaming by increasing the cross-link density of low-density poly ethylene using 1.5 parts per hundred dicumyl peroxide that enhances composite tensile and compressive strength up to 57% and 15%, respectively. The composite has the potential to be used as a foaming mat for artificial turf.

  1. Dexamethasone-loaded poly(ε-caprolactone)/silica nanoparticles composites prepared by supercritical CO2 foaming/mixing and deposition.

    Science.gov (United States)

    de Matos, M B C; Piedade, A P; Alvarez-Lorenzo, C; Concheiro, A; Braga, M E M; de Sousa, H C

    2013-11-18

    A supercritical carbon dioxide (scCO2)-assisted foaming/mixing method (SFM) was implemented for preparing dexamethasone (DXMT)-loaded poly(ε-caprolactone)/silica nanoparticles (PCL/SNPs) composite materials suitable for bone regeneration. The composites were prepared from PCL and mesoporous SNPs (MCM-41/SBA-15) by means of scCO2-assisted SFM at several operational pressures, processing times and depressurization conditions. DXMT was loaded into SNPs (applying a scCO2 solvent impregnation/deposition method - SSID) and into PCL/SNPs composites (using the SFM method). The effects of the employed operational and compositional variables on the physicochemical and morphological features as well as in the in vitro release profiles of DXMT were analyzed in detail. This work demonstrates that the above-referred scCO2-based methods can be very useful for the preparation of DXMT-loaded PCL/SNPs composites with tunable physicochemical, thermomechanical, morphological and drug release properties and suitable for hard-tissue regeneration applications.

  2. Batch production of micron size particles from poly(ethylene glycol) using supercritical CO2 as a processing solvent

    NARCIS (Netherlands)

    Nalawade, Sameer P.; Picchioni, Francesco; Janssen, L. P. B. M.

    2007-01-01

    The major advantage of using supercritical carbon dioxide (CO2) as a solvent in polymer processing is an enhancement in the free volume of a polymer due to dissolved CO2, which causes a considerable reduction in the viscosity. This allows spraying the polymer melt at low temperatures to produce micr

  3. Economic Analysis of an Integrated Annatto Seeds-Sugarcane Biorefinery Using Supercritical CO2 Extraction as a First Step

    Science.gov (United States)

    Albarelli, Juliana Q.; Santos, Diego T.; Cocero, María José; Meireles, M. Angela A.

    2016-01-01

    Recently, supercritical fluid extraction (SFE) has been indicated to be utilized as part of a biorefinery, rather than as a stand-alone technology, since besides extracting added value compounds selectively it has been shown to have a positive effect on the downstream processing of biomass. To this extent, this work evaluates economically the encouraging experimental results regarding the use of SFE during annatto seeds valorization. Additionally, other features were discussed such as the benefits of enhancing the bioactive compounds concentration through physical processes and of integrating the proposed annatto seeds biorefinery to a hypothetical sugarcane biorefinery, which produces its essential inputs, e.g., CO2, ethanol, heat and electricity. For this, first, different configurations were modeled and simulated using the commercial simulator Aspen Plus® to determine the mass and energy balances. Next, each configuration was economically assessed using MATLAB. SFE proved to be decisive to the economic feasibility of the proposed annatto seeds-sugarcane biorefinery concept. SFE pretreatment associated with sequential fine particles separation process enabled higher bixin-rich extract production using low-pressure solvent extraction method employing ethanol, meanwhile tocotrienols-rich extract is obtained as a first product. Nevertheless, the economic evaluation showed that increasing tocotrienols-rich extract production has a more pronounced positive impact on the economic viability of the concept. PMID:28773616

  4. Pore-scale observation and 3D simulation of wettability effects on supercritical CO2 - brine immiscible displacement in drainage

    Science.gov (United States)

    Hu, R.; Wan, J.; Chen, Y.

    2016-12-01

    Wettability is a factor controlling the fluid-fluid displacement pattern in porous media and significantly affects the flow and transport of supercritical (sc) CO2 in geologic carbon sequestration. Using a high-pressure micromodel-microscopy system, we performed drainage experiments of scCO2 invasion into brine-saturated water-wet and intermediate-wet micromodels; we visualized the scCO2 invasion morphology at pore-scale under reservoir conditions. We also performed pore-scale numerical simulations of the Navier-Stokes equations to obtain 3D details of fluid-fluid displacement processes. Simulation results are qualitatively consistent with the experiments, showing wider scCO2 fingering, higher percentage of scCO2 and more compact displacement pattern in intermediate-wet micromodel. Through quantitative analysis based on pore-scale simulation, we found that the reduced wettability reduces the displacement front velocity, promotes the pore-filling events in the longitudinal direction, delays the breakthrough time of invading fluid, and then increases the displacement efficiency. Simulated results also show that the fluid-fluid interface area follows a unified power-law relation with scCO2 saturation, and show smaller interface area in intermediate-wet case which suppresses the mass transfer between the phases. These pore-scale results provide insights for the wettability effects on CO2 - brine immiscible displacement in geologic carbon sequestration.

  5. Comparative analysis of the oil and supercritical CO(2) extract of Schinus molle L. growing in Yemen.

    Science.gov (United States)

    Ali, Nasser A Awadh; Marongiu, Bruno; Piras, Alessandra; Porcedda, Silvia; Falconieri, Danilo; Al-Othman, Al-Husein M R

    2011-08-01

    In this study, we report the preliminary data on the chemical composition of Yemeni Schinus molle L. volatile oil obtained by supercritical extraction with carbon dioxide (40°C and 90 bar), SFE, and by hydrodistillation (HD). The composition of the volatile oil has been analysed by GC and GC-MS. The content of the major constituents in the oils from leaves varied in the following ranges: germacrene D 3.7% in SFE and 16.7% in HD; β-caryophyllene 19.1% in SFE and 13.5% in HD. The amount of monoterpenes constituted 4%, in all the analysed samples, while the number of sesquiterpenes was 44% in supercritical and 67% in HD oil. Some compounds were not identified by GC-MS and it will require further analysis using other analytical techniques.

  6. Supercritical CO2 extraction of Schinus molle L with co-solvents: mathematical modeling and antimicrobial applications

    OpenAIRE

    Rodrigo Scopel; Roberto Góes Neto; Manuel Alves Falcão; Eduardo Cassel; Rubem Mário Figueiró Vargas

    2013-01-01

    This work investigates the antimicrobial activity of the Schinus molle L. leaves extracts obtained under supercritical conditions using carbon dioxide and co-solvents. Antimicrobial qualitative evaluation was carried out through the bioautography technique and the microorganisms studied were Staphylococcus aureus, Pseudomonas aeruginosas, Escherichia coli, Micrococcus luteus, and Salmonella choleraesuis. The supercritical fluid extraction was carried out in a pilot scale equipment using carbo...

  7. Batch production of micron size particles from poly(ethylene glycol) using supercritical CO2 as a processing solvent

    NARCIS (Netherlands)

    Nalawade, Sameer P.; Picchioni, Francesco; Janssen, L. P. B. M.

    The major advantage of using supercritical carbon dioxide (CO2) as a solvent in polymer processing is an enhancement in the free volume of a polymer due to dissolved CO2, which causes a considerable reduction in the viscosity. This allows spraying the polymer melt at low temperatures to produce

  8. Extraction and Separation of Volatile and Fixed Oils from Berries of Laurus nobilis L. by Supercritical CO2

    Directory of Open Access Journals (Sweden)

    M. Assunta Dessì

    2008-08-01

    Full Text Available Isolation of volatile and fixed oils from dried berries of Laurus nobilis L. from Tunisia have been obtained by supercritical fractioned extraction with carbon dioxide. Extraction experiments were carried out at a temperature of 40 °C and pressures of 90 and 250 bar. The extraction step performed at 90 bar produced a volatile fraction mainly composed of (E-β-ocimene (20.9%, 1,8-cineole (8.8%, α-pinene (8.0%, β-longipinene (7.1%, linalool acetate (4.5%, cadinene (4.7%, β-pinene (4.2%, α-terpinyl acetate (3.8% and α-bulnesene (3.5%. The oil yield in this step of the process was 0.9 % by weight charged. The last extraction step at 250 bar produced an odorless liquid fraction, in which a very small percentage of fragrance compounds was found, whereas triacylglycerols were dominant. The yield of this step was 15.0 % by weight. The most represented fatty acids of the whole berry fixed oil were 12:0 (27.6%, 18:1 n-9 (27.1%, 18:2 n-6 (21.4%, and 16:0 (17,1%, with the 18:1 n-9 and 18:2 n-6 unsaturated fatty acids in particular averaging 329 μg/mg of oil.

  9. Application of a phosphazene derivative as a flame retardant for cotton fabric using conventional method and supercritical CO2

    Science.gov (United States)

    Conventional pad-dry-cure (non-scCO2) and supercritical carbon dioxide (scCO2) application methods were investigated to study the effectiveness of a phosphazene derivative as a flame retardant on cotton fabric. 1,1',4,5-tetrahydrotrispiro[1,3,2-diazaphosphole-2,2'-[1,3,5,2,4,6]triazatriphosphinine-4...

  10. Enrichment desired quality chitosan fraction and advance yield by sequential static and static-dynamic supercritical CO2.

    Science.gov (United States)

    Hsieh, Yi-Yin; Chin, Hui Yen; Tsai, Min-Lang

    2015-11-20

    This study aimed to establish the sequential static and static-dynamic supercritical carbon dioxide (SDCO2) fractionation conditions to obtain a higher yield and desired chitosan with lower polydispersity index (PDI) and higher degree of deacetylation (DD). The yield increased with increasing DD of used chitosan and amount of cosolvent. The yield of acetic acid cosolvent was higher than those of malic and citric acid cosolvents. SDCO2, compared to static supercritical carbon dioxide, has higher yield. The yield of extracted chitosan was 5.82-14.70% by SDCO2/acetic acid, which increases with increasing pressure. The DD of fractionated chitosan increased from 66.1% to 70.81-85.33%, while the PDI decreased from 3.97 to 1.69-3.16. The molecular weight changed from 622kDa to 412-649kDa, which increased as density of supercritical carbon dioxide increases. Hence, higher DD and lower PDI extracted chitosan can be obtained through controlling the temperature and pressure of SDCO2.

  11. Supercritical CO2 extraction of Schinus molle L with co-solvents: mathematical modeling and antimicrobial applications

    Directory of Open Access Journals (Sweden)

    Rodrigo Scopel

    2013-06-01

    Full Text Available This work investigates the antimicrobial activity of the Schinus molle L. leaves extracts obtained under supercritical conditions using carbon dioxide and co-solvents. Antimicrobial qualitative evaluation was carried out through the bioautography technique and the microorganisms studied were Staphylococcus aureus, Pseudomonas aeruginosas, Escherichia coli, Micrococcus luteus, and Salmonella choleraesuis. The supercritical fluid extraction was carried out in a pilot scale equipment using carbon dioxide modified by the addition of co-solvents, such as ethanol and water at 150 bar and 333 K. A mathematical modeling of the process was also performed.

  12. Hydroxyapatite-TiO(2)-based nanocomposites synthesized in supercritical CO(2) for bone tissue engineering: physical and mechanical properties.

    Science.gov (United States)

    Salarian, Mehrnaz; Xu, William Z; Wang, Zhiqiang; Sham, Tsun-Kong; Charpentier, Paul A

    2014-10-08

    Calcium phosphate-based nanocomposites offer a unique solution toward producing scaffolds for orthopedic and dental implants. However, despite attractive bioactivity and biocompatibility, hydroxyapatite (HAp) has been limited in heavy load-bearing applications due to its intrinsically low mechanical strength. In this work, to improve the mechanical properties of HAp, we grew HAp nanoplates from the surface of one-dimensional titania nanorod structures by combining a coprecipitation and sol-gel methodology using supercritical fluid processing with carbon dioxide (scCO2). The effects of metal alkoxide concentration (1.1-1.5 mol/L), reaction temperature (60-80 °C), and pressure (6000-8000 psi) on the morphology, crystallinity, and surface area of the resulting nanostructured composites were examined using scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), and Brunauer-Emmet-Teller (BET) method. Chemical composition of the products was characterized using Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and X-ray absorption near-edge structure (XANES) analyses. HAp nanoplates and HAp-TiO2 nanocomposites were homogeneously mixed within poly(ε-caprolactone) (PCL) to develop scaffolds with enhanced physical and mechanical properties for bone regeneration. Mechanical behavior analysis demonstrated that the Young's and flexural moduli of the PCL/HAp-TiO2 composites were substantially higher than the PCL/HAp composites. Therefore, this new synthesis methodology in scCO2 holds promise for bone tissue engineering with improved mechanical properties.

  13. Economic Analysis of an Integrated Annatto Seeds-Sugarcane Biorefinery Using Supercritical CO2 Extraction as a First Step

    OpenAIRE

    Albarelli, Juliana Q.; Diego T. Santos; María José Cocero; M. Angela A. MEIRELES

    2016-01-01

    Recently, supercritical fluid extraction (SFE) has been indicated to be utilized as part of a biorefinery, rather than as a stand-alone technology, since besides extracting added value compounds selectively it has been shown to have a positive effect on the downstream processing of biomass. To this extent, this work evaluates economically the encouraging experimental results regarding the use of SFE during annatto seeds valorization. Additionally, other features were discussed such as the ben...

  14. Supercritical CO2 Assisted Synthesis of EDTA-Fe3O4 Nanocomposite with High Adsorption Capacity for Hexavalent Chromium

    Directory of Open Access Journals (Sweden)

    Gunjan Bisht

    2016-01-01

    Full Text Available Efficiency of EDTA functionalized nanoparticles in adsorption of chromium (VI from water was investigated in this study. Magnetic iron oxide nanoparticles (IONPs were synthesized by a simple chemical coprecipitation route and EDTA coating onto IONPs was attained via supercritical carbon dioxide (Sc CO2, a technology with green sustainable properties. The obtained nanoparticles were then characterized by UV-Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR, X-ray powder diffraction (XRD, transmission electron microscopy (TEM, scanning electron microscopy (SEM, and vibrating magnetometric analysis (VSM. The synthesized nanoparticle and its modified variant were evaluated as adsorbent for chromium (VI removal from water through batch adsorption technique and the effect of analytic concentration; contact time and adsorbent concentration were studied at pH 2. The results showed higher removal efficiency for modified magnetic iron oxide nanoparticles (MIONPs (i.e., 99.9% than their nonmodified variant IONPs, that is, 34.06% for the same concentration after 18 hours of incubation. Also maximum adsorption capacity (qe = 452.26 mg/g of MIONPs attained can be related to their preparation in Sc CO2 as qe calculated from IONPs, that is, 170.33 mg/g, is lower than that of MIONPs. The adsorption data fit well with Freundlich isotherm equation while kinetic adsorption studies of chromium (VI were modeled by pseudo-second-order model.

  15. Supercritical CO2 extract and essential oil of bay (Laurus nobilis L.) – chemical composition and antibacterial activity

    OpenAIRE

    2010-01-01

    The present study deals with the supercritical carbon dioxide (SC-CO2) extraction and hydrodistillation (HD) of dried bay leaves (Laurus nobilis L.). The chemical composition and antibacterial activity of the SC-CO2 extract and essential oil (EO) from dried leaves of bay were compared to each other and literature data. Qualitative and quantitative analyses of the SC-CO2 extract and EO were performed using GC–FID and GC–MS analytical methods. A significant difference in the chemical compositio...

  16. Supercritical CO(2)-extracted tomato Oleoresins enhance gap junction intercellular communications and recover from mercury chloride inhibition in keratinocytes.

    Science.gov (United States)

    Leone, Antonella; Zefferino, Roberto; Longo, Cristiano; Leo, Lucia; Zacheo, Giuseppe

    2010-04-28

    A nutritionally relevant phytochemical such as lycopene, found in tomatoes and other fruits, has been proposed to have health-promoting effects by modulating hormonal and immune systems, metabolic pathways, and gap junction intercellular communication (GJIC). This work analyzes lycopene extracts, obtained from tomato and tomato added with grape seeds by using a safe and environmentally friendly extraction process, based on supercritical carbon dioxide technology (S-CO(2)). Analysis of the innovative S-CO(2)-extracted oleoresins showed peculiar chemical composition with high lycopene concentration and the presence of other carotenoids, lipids, and phenol compounds. The oleoresins showed a higher in vitro antioxidant activity compared with pure lycopene and beta-carotene and the remarkable ability to enhance the GJIC and to increase cx43 expression in keratinocytes. The oleoresins, (0.9 microM lycopene), were also able to overcome, completely, the GJIC inhibition induced by 10 nM HgCl(2), mercury(II) chloride, suggesting a possible action mechanism.

  17. Supercritical CO2 extract and essential oil of bay (Laurus nobilis L. – chemical composition and antibacterial activity

    Directory of Open Access Journals (Sweden)

    JASNA IVANOVIĆ

    2010-03-01

    Full Text Available The present study deals with the supercritical carbon dioxide (SC-CO2 extraction and hydrodistillation (HD of dried bay leaves (Laurus nobilis L.. The chemical composition and antibacterial activity of the SC-CO2 extract and essential oil (EO from dried leaves of bay were compared to each other and literature data. Qualitative and quantitative analyses of the SC-CO2 extract and EO were performed using GC–FID and GC–MS analytical methods. A significant difference in the chemical composition of the SC-CO2 extract and EO was observed. The EO comprised high contents of monoterpenes and their oxygenated derivates (98.4 %, principally 1,8-cineole (33.4 %, linalool (16.0 % and α-terpinyl acetate (13.8 %, sabinene (6.91 % and methyl eugenol (5.32 %. The SC-CO2 extract comprised twice less monoterpenes and their oxygenated derivates (43.89 %, together with sesquiterpenes (12.43 %, diterpenes (1.33 % and esters (31.13 %. The major components were methyl linoleate (16.18 %, α-terpinyl acetate (12.88 %, linalool (9.00 %, methyl eugenol (8.67 %, methyl arachidonate (6.28 % and eugenol (6.14 %. An investigation of the antibacterial activity of bay SC-CO2 extract and EO was completed on different Staphylococcus strains using the broth macrodilution method. Staphylococcus intermedius strains were the most susceptible to both the SC-CO2 extract and EO (MIC = 640 µg/ml.

  18. Supercritical CO2 extraction of candlenut oil: process optimization using Taguchi orthogonal array and physicochemical properties of the oil.

    Science.gov (United States)

    Subroto, Erna; Widjojokusumo, Edward; Veriansyah, Bambang; Tjandrawinata, Raymond R

    2017-04-01

    A series of experiments was conducted to determine optimum conditions for supercritical carbon dioxide extraction of candlenut oil. A Taguchi experimental design with L9 orthogonal array (four factors in three levels) was employed to evaluate the effects of pressure of 25-35 MPa, temperature of 40-60 °C, CO2 flow rate of 10-20 g/min and particle size of 0.3-0.8 mm on oil solubility. The obtained results showed that increase in particle size, pressure and temperature improved the oil solubility. The supercritical carbon dioxide extraction at optimized parameters resulted in oil yield extraction of 61.4% at solubility of 9.6 g oil/kg CO2. The obtained candlenut oil from supercritical carbon dioxide extraction has better oil quality than oil which was extracted by Soxhlet extraction using n-hexane. The oil contains high unsaturated oil (linoleic acid and linolenic acid), which have many beneficial effects on human health.

  19. [Optimization of supercritical CO2 extraction of plantaginis semen oil by response surface methodology and studies on its antioxidant activity].

    Science.gov (United States)

    Xu, Wei; Ling, Weijian; Chu, Kedan; Li, Huang; Chen, Lidian; Zhang, Yuqin; Chen, Xianwen

    2011-12-01

    The optimum conditions of SFE-CO2 extraction of Plantaginis Semen oil (SPO), the composition of SPO and its antioxidant activities of SPO were all investigated in this paper. Response surface method (RSM) was used