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Supercritical Fluids: Properties and Applications

What Is a Supercritical Liquid?

Any matter pushed to temperatures and pressures where it is no longer possible to distinguish between the liquid and gas phase becomes a supercritical fluid. Examples of such processes include decaffeination and power generation.

Supercritical fluids feature the favourable properties of both gases and liquids. They can be manipulated by adjusting their temperature and pressure.

Temperature

Any material pushed to higher temperatures and pressures beyond its critical point stops being liquid or gas, becoming a supercritical fluid.

The density of a supercritical fluid is between that of a gas and that of a liquid. Diffusion is faster and viscosity lower than in liquids, which enables the rapid matrix penetration of extraction solvents. This makes it easier to extract samples and elute them faster than in HPLC.

Surface tension is also lower, which helps to reduce the dilution effect and minimizes sample loss. These properties are essential for high-throughput chromatography, where SCF’s larger solvent power enables shorter reaction times than HPLC. Also, extraction in SCF prevents the heating that occurs during traditional methods, minimizing decomposition of temperature-sensitive materials.

Pressure

When a supercritical fluid is heated to its critical point it no longer exists as distinct gas and liquid phases. At this point it is highly compressible, with a small change in temperature resulting in a large change in its density.

This property makes it possible to use supercritical carbon dioxide for extraction. It can effuse through porous solids like a gas, overcoming mass transfer limitations that slow the dissolution of liquids through these materials. It can also dissolve solids such as minerals, making it an effective substitute for organic solvents in many processes.

In addition, scCO2 has solvent power similar to that of light hydrocarbons for most solutes. Moreover, a high degree of selectivity can be achieved by controlling both the temperature and pressure.

Density

The density of a supercritical fluid can vary depending on the temperature and pressure. At lower temperatures, the density is higher than that of a liquid and at higher temperatures it is lower. At a temperature and pressure above the critical point, the density becomes equal to that of a gas and the distinction between the two phases disappears.

In this phase, the SCF can effuse through porous solids like a gas and dissolve materials that are difficult for gases to penetrate into, such as proteins (see Figure 1). This makes SCFs suitable as substitutes for organic solvents in many industrial processes, including coffee decaffeination and power generation.

The solvent strength of a SCF is related to its density. Typically, a substance with densities of greater than 1.0 g/cm3 has solvent strengths comparable to light hydrocarbons for most solutes.

Viscosity

A supercritical fluid is neither a gas nor a liquid but an intermediate state between the two extremes. It has a density property close to that of a liquid and solvent power comparable to that of a gas.

Solubility in a supercritical fluid is influenced by both temperature and pressure. In general, solubility increases with increased temperature and decreases with increasing pressure, compared to ambient conditions.

SCFs have many properties that can be fine-tuned by varying the temperature and pressure. This makes them ideal green alternatives to organic solvents in numerous key industrial processes. For example, scCO2 is the preferred solvent for dyeing polyester fibres with disperse (non-ionic) dyes. Its high solubility also allows the SCF to effuse through porous solid materials such as polymer sludges, overcoming mass transfer limitations that slow a liquid transport in these materials.

Solubility

Solubility is a property of a substance that determines its ability to dissolve other substances. This is based on the principle that like dissolves like, such as petroleum jelly dissolving in gasoline. Other separation methods, such as absorption and extraction, rely on differences in solubility to separate materials.

The solubility of a supercritical fluid increases as the temperature and pressure are increased. The limiting point of this increase is known as the critical temperature and pressure (Tc and Pc). Below Tc and Pc the distinction between gases and liquids disappears.

At these conditions, a supercritical fluid can diffuse through solids as a gas and dissolve materials as a liquid. This makes it a very versatile solvent. It is used in a variety of industrial processes such as dyeing textiles and tanning leather.

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Extraction using Supercritical Fluid Technology: A Clean and Efficient Method for Substance Extraction

Extraction Using Supercritical Fluid Technology

Supercritical fluid technology (SCF) is one of the most promising technologies in pharmaceutical formulation due to its non-toxic, inert, economical and environmentally friendly characteristics. It can be used for numerous applications such as RESS and anti-solvent micronization techniques, porous emulsion-based drug carriers and SCF-guided encapsulation of active ingredients (AIs) in aerogels.

Extraction

Extraction using supercritical fluid technology is a simple, fast, inexpensive and clean method that can be used to extract a variety of substances such as chemicals, polymers, pharmaceuticals, biologicals, food products, metals and ceramics. The extraction procedure does not produce any waste and the extracted substance is not harmful for the environment, a significant advantage over traditional extraction methods.

Supercritical carbon dioxide is an attractive solvent for extraction because of its close solvating properties to liquids, high diffusivity and near zero surface tension characteristics similar to gases. It also has a critical temperature and pressure that can be adjusted.

Temperature and pressure can significantly influence the extraction yield. Increasing the temperature decreases the solvent density, thus reducing solubility and decreasing oil extraction. Alternatively, increasing the pressure at a constant temperature increases the oil yield. Therefore, the optimal extraction parameters should be carefully selected.

Fractionation

A fluid is considered supercritical when its temperature and pressure are above the critical point (Tc, Pc). Beyond this critical value, the fluid cannot be transformed into gas or liquid by increasing either the temperature or the pressure.

It has the properties of both a gas and a liquid: its density is similar to that of a liquid but it has the diffusivity of a gas. This makes it a good processing medium for many types of extractions.

For example, using supercritical carbon dioxide, it is possible to extract non-polar compounds like alkanes. For polar compounds, a small amount of co-solvent is added to the system.

The resulting mixture is then transferred to the separation unit, mostly a chromatography instrument. This process avoids the extra manipulation step required in off-line extraction, and minimizes errors due to handling. This method is especially useful for cellular fractionation. The lysed components are directly transported from the extraction system to the chromatography instrument without being manipulated.

Separation

In order to separate a desired compound from the supercritical fluid, its properties can be altered by varying temperature and pressure. For example, by lowering the temperature of CO2 it can pass from liquid to gas without crossing the boundary between the two states, making separation possible.

Another benefit of using SCF is that unlike conventional extraction techniques which require the use of toxic and flammable organic solvents, separation is performed without any residues. This is known as green chemistry and contributes to safer production environments.

In the PGSS process, a pharmaceutical substance is solubilized by adding a polymer to a supercritical solution of carbon dioxide and then expanding it through a nozzle. This results in the precipitation of desire particles free from residual solvent. The solubility of a polymer in SCF-CO2 depends on its molecular weight, intermolecular hydrogen bonding and polarity. A limitation of this technique is that the solubility in high temperatures can result in particle aggregation and nozzle blockage.

Purification

Extraction using supercritical fluids is far more efficient than traditional extraction methods. The solvents used are non-toxic and very environmentally friendly. They are also very powerful, allowing for the removal of substances that would not be possible with conventional solvents. For example, coffee beans that need to be decaffeinated can be treated with CO2, which will remove the caffeine without damaging the bean. The supercritical carbon dioxide will simply be vented once the process is complete, eliminating the need for a separate ventilation system and leaving no residual solvent behind.

In addition, SFC provides a solution for the processing of temperature-sensitive compounds and materials with low vapor pressure/volatility. The high pressure conditions make it possible to work with materials that would be difficult or impossible to analyze under normal HPLC conditions, since they require a very hot temperature. The diffusivity of components within a supercritical fluid is also much higher than that of traditional liquid mobile phases, making the SFC separation more effective.

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Experiencing the NBA: The Thrill, Excitement, and Global Community

The thrill of basketball is universal, and when it comes to the NBA, the excitement reaches fever pitch levels. Fans around the globe are eager to catch every dribble, dunk, and dramatic finish, which makes the ability to watch NBA games live a coveted experience. For many enthusiasts in Korea, finding a reliable NBA중계 (NBA broadcast) is essential to staying connected with their favorite teams and players.

Basketball is more than just a game; it’s a showcase of athleticism, strategy, and the unyielding spirit of competition. The NBA, with its array of superstar talents and storied franchises, offers a spectacle that is unmatched in the world of sports. To follow every moment of this thrilling league, an NBA중계 provides fans with the live action as it unfolds, creating a communal experience for discussions, celebrations, and real-time reactions.

One might wonder, why is the NBA so captivating? Imagine the scene: the clock is ticking down, the crowd is on its feet, and the ball is in the hands of the team’s star player. It’s these moments that transcend the screen and draw viewers into the heart of the action. Through an NBA중계, fans are transported courtside, feeling every tension-filled second.

The NBA’s influence stretches across oceans, resonating with fans who appreciate the blend of skill, finesse, and sheer physicality. Korean fans, much like those anywhere else in the world, look for that connection to the global basketball community. An NBA중계 serves as their link, allowing them to follow the latest storylines, whether it’s the emergence of a rookie sensation, the dominance of established veterans, or the unfolding drama of the playoffs.

As the season progresses, each game gains in significance. An NBA중계 not only broadcasts these games but also brings the culture and excitement of the NBA into living rooms. It allows young fans to model their layups after their idols or debate with friends over the most clutch performer. This isn’t just watching a sport; it’s an engagement with a culture that reverberates through every slam dunk and three-pointer.

In conclusion, the quest for live NBA action among Korean fans is about more than staying updated with scores and stats. It’s about experiencing the highs and lows of the season, witnessing history in the making, and being a part of a community that celebrates excellence in sportsmanship and athletic prowess. With a reliable NBA중계, every game is a chance to be a part of something bigger—a global family of basketball devotees.

FAQs:

1. What is an NBA중계?
An NBA중계 is a live broadcast of NBA basketball games, providing fans with real-time coverage of the action as it happens.

2. Why is the NBA popular in Korea?
The NBA’s mix of high-level athleticism, competitive games, and basketball culture has garnered a significant following in Korea, where many fans appreciate the global nature of the sport.

3. Can I follow my favorite NBA team through an NBA중계?
Yes, an NBA중계 typically offers coverage of all NBA teams, allowing fans to follow their favorite teams and players throughout the season.

4. Are NBA중계 services available in the Korean language?
Many NBA broadcast services offer Korean language options to cater to the local audience, enhancing the viewing experience.

5. How do live NBA broadcasts enhance the fan experience?
Live NBA broadcasts create a sense of immediacy and community, allowing fans to experience the game’s excitement and engage in discussions and social interactions around the sport in real-time.…

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Supercritical fluids: a greener alternative to organic solvents for various industrial processes.

Green Alternative to Organic Solvents

Many industrial processes can be done using supercritical fluids as a green alternative to organic solvents. SCF is non-toxic, non-flammable and chemically inert.

Its high diffusion enables it to flow over and impregnate solid substances, such as dyeing textile fibres or tanning leather. Its low critical temperature and pressure allows for a large range of industrial applications.

Extraction

Supercritical fluids are mixtures of gases and liquids, whose properties can be manipulated through temperature and pressure. They are typically used as solvents for industrial extraction and characterization of natural products, among other applications. They can also be used to control the particle size of raw materials. The UASFE process is an example of this application.

During this method, the supercritical CO2 is pumped into an extraction vessel where it passes through a bed of milled raw material. The pressure of the SCF is regulated by a back pressure regulator. The bed is heated to avoid agglomeration and promote dissolution of the particles.

The analytes are then collected in a trap, inert or active, which is then transferred to a gas chromatograph for analysis. This method can be applied on a laboratory scale to extract components from solid or liquid matrices, as well as at a larger scale for chiral separations. It is a greener alternative to conventional solvents such as hexane and ethyl acetate.

Micronisation

A supercritical fluid can be used to micronise solid materials. The process involves dissolving a solid substance in a SCF, then rapidly expanding it through depressurization to form a fine particle system. The technique is more efficient than conventional methods and allows for faster chemical reactions. It is also more environmentally friendly and cost effective than conventional solvents.

A SCF behaves like a liquid at a pressure above its critical point, but has the density of a gas and the diffusivity of a gas. This property makes it useful for industrial applications such as extraction, dyeing and other processes that require high-pressure fluids.

For example, CO2 at high pressure acts like an organic solvent and can dissolve oils, fats, cholesterol and ibuprofen. It is used in coffee and tea decaffeination, hop extract for beer production, leather tanning, removing TCA from cork and extraction of essential oils. It can also be used in cleaning products and to make synthetic chemicals.

Impregnation

Supercritical CO2 impregnation is a greener alternative to organic solvents and improves both flexibility and active substance penetration in entangled polymer chains. In addition, it also allows a faster contact time and a more quantitative application than conventional aqueous or solvent-based methods.

The process uses food grade carbon dioxide as the extracting solvent and is generally operated in batch mode on milled material (or pellets, granulates). Extraction conditions are above the critical pressure of CO2. After extraction, the solution is rapidly expanded by depressurization and dissolved materials quickly precipitate for collection.

A Raman spectrometer was used to observe unmixing of the supercritical fluid and silicate melts. Spectra showed the presence of monomers in the 770 cm band of the aqueous and supercritical silicate liquids. Interestingly, the 770 cm band in the spectra of scCO2 was relatively sharp and was not significantly modified by cooling, suggesting the existence of a phase boundary at a low temperature.

Diffusion

A supercritical fluid (SCF) is a compressed gas that exhibits properties of both liquids and gases. The SCF has a density close to that of liquids and a diffusion rate similar to that of gases. It also has the ability to dissolve and extract materials. These features make it a versatile, green alternative to organic solvents.

The SCF has a number of key industrial applications. For example, it is used in extraction processes such as coffee/tea decaffeination, hop extraction for beer production and removal of TCA from cork. It can also be used to extract non-polar or slightly polar compounds such as oils and pharmaceuticals such as ibuprofen.

In addition, the SCF can be used to impregnate polymer fibres with dyes or chemicals. In this process, the SCF flows over an inert substrate and saturates it with the chemical. This can be used in textile dyeing and impregnating wood, among other processes. The SCF also serves as an excellent plasticising agent, which reduces the glass transition temperature.

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Exploring the Potential of Supercritical Fluid Plasmas

What is Supercritical Fluid Plasma?

Supercritical fluid (SCF) has the properties of a gas and a liquid. It has a long lifetime for ions and electrons generated in discharge plasmas, resulting in solvated particles.

These particles can interact with each other by a Coulomb force. SCF also allows for pseudo-microgravity conditions. This opens up a new area of strongly coupled plasmas.

What is a supercritical fluid?

A supercritical fluid (SCF) is a substance above its critical temperature and pressure point, where the liquid and gas phases no longer exist. It has a density higher than that of gases, but lower than that of liquids (see Fig. 1). Close to the critical point, small changes in pressure cause large changes in the density of an SCF.

Because of this, SCFs can effuse through porous solids like a gas while dissolving materials like a liquid. They can also overcome the mass transfer limitations that slow the movement of liquids through such materials.

Supercritical CO2 is used in a wide range of industrial applications, such as decaffeination and the extraction of botanical oils. It can also be used to perform biomass gasification, a process that converts renewable biofuels into fuel for energy. This technology can provide a more sustainable alternative to traditional methods for extracting natural products. Supercritical water is also used in a variety of industrial applications, including removing toxic chemicals from foods and reducing the glass transition temperature of polymers.

What is a supercritical plasma?

Plasmas generated in high-density medium have received increasing attention from both pure sciences and materials processing applications. Especially, plasmas in supercritical fluid have attracted attention from the point of view of nanomaterials synthesis.

A supercritical fluid (SCF) is a mixture of solvent and non-solvent gases at pressures above the critical pressure. It occurs naturally in the atmospheres of Jupiter, Saturn, Venus and Uranus, as well as Earth’s hydrothermal vents. On Earth, SCF is used in many industrial processes such as decaffeination and power generation.

SCF can be sprayed on the surface of solids, enabling them to dry without the usual distortions caused by surface tension. The technique is also useful for preparing samples for electron microscopy. This process has advantages over other methods of drying, such as vacuum evaporation and oven baking. It can also remove organic film from a sample surface, which could otherwise oxidize in the air.

What are the properties of a supercritical fluid?

The properties of a supercritical fluid vary according to the temperature and pressure conditions in which it is in a critical state. This region on the vapor pressure curve is called the critical point. Substances in this state have the properties of both a gas and a liquid: they are much more dense than gases, but less dense than solids.

This allows them to dissolve and solvate species far more effectively than a pure gas can. They also have high diffusivities compared to the low values of liquid solvents, which improves mass transfer processes.

Additionally, they can be tuned by modifying the operating temperature and pressure to optimize the properties for a specific process. Due to their properties, supercritical fluids have been used in several industrial processes including adsorption, extraction, particle formation, and depressurization. They are non-flammable, non-toxic, and environmentally safe. This makes them a great alternative to organic solvents with their environmental and safety issues such as volatility, residue, and toxicity.

What are the properties of a supercritical plasma?

A supercritical fluid has properties between those of a liquid and gas. It is able to diffuse through solids like a gas and dissolve materials such as polymers better than a liquid, but can also change its density rapidly upon small changes in temperature and pressure. It is a key ingredient of the industrial process for decaffeinating coffee, for example.

Baron Charles Cagniard de la Tour discovered the critical point for a substance by listening to discontinuities in the sound of a rolling flint ball in his cannon barrel experiments. Above this point the gas and liquid phases cannot coexist in equilibrium with each other.

Plasmas generated in high-density medium have been receiving much attention for their usefulness in materials processing, such as nanomaterials synthesis. In particular, plasmas near the critical point of Carbon Dioxide have been investigated with an emphasis on molecular clustering and density fluctuations. They are promising candidates for a wide range of applications, including natural products, pharmaceuticals, functional food ingredients, powders, bio- and functional materials, microelectronics, fossil and bio-fuels and energy.

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Experience the Excitement of mlb중계

Experience the Thrill of mlb중계

If you’re a baseball fan, you surely understand how exciting it is to follow the . With a rich heritage and a competitive field, the Major League Baseball (MLB) games from MLB중계 brings the stadium’s electrifying energy right into your living room.

HEAR the crack of a bat with mlb중계

Just imagine this scenario. You’re sitting in your favorite chair, perhaps with your favorite snack, and you tune in to . The sound of audiences cheering, the crack of the bat as it sends a baseball flying – the sound alone transports you to the game, making your heart beat faster with exhilaration. Isn’t it fantastic?

SEE the action with mlb중계

The visuals are just as captivating. The green field, the players in action, the gritty determination visible on their faces – everything about screams passion, drama, and a love for the sport. You become a part of the excitement, sharing the joys of victory and the disappointment of defeat with the players.

FEEL the energy with mlb중계

The allure of mlb중계 is not just about the sights and sounds. It’s about the thrill of the chase, the unpredictable twists and turns, and the jaw-dropping moments that leave you at the edge of your seat. You can feel the palpable energy and tension, and that’s what makes mlb중계 such a fascinating experience.

Conclusion

Mlb중계 is not just the transmission of Major League Baseball games. It’s the embodiment of the thrill, the tensions, and the exhilarating highs of professional baseball. It brings you right into the heart of the action, providing a dynamic and immersive viewing experience that is difficult to match.

FAQs:

How can I access mlb중계?

You can access mlb중계 through various providers that offer live streaming of Major League Baseball games.

Is mlb중계 available worldwide?

Mlb중계 is generally available worldwide, although certain areas may have restrictions due to licensing agreements.

How can I enhance my viewing experience with mlb중계?

To enhance your viewing experience, you might want to consider getting a good quality screen and speakers to really get into the game.

Is every MLB game broadcast on mlb중계?

Most games are broadcast on mlb중계, although there may be some exceptions due to scheduling conflicts or other factors.

Can I watch previous games on mlb중계?

Some providers may offer archives or replays of previous games as part of their mlb중계 service.…

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Superiority of Supercritical Fluids in Chemical Engineering Processes

Supercritical Fluid Video

Supercritical fluids (SCF) are a key component in sustainable chemical engineering processes. They exhibit the advantages of both liquids and gases.

They are non-toxic, inert, low flammability and cost effective. They are also non-polluting, which makes them ideal for industrial applications such as extraction and synthesis.

This journal focuses on fundamental and applied aspects of the science and technology of SCF. Topics include thermodynamics and phase equilibria, reaction kinetics and rate processes, thermal properties, and transport phenomena.

What is a supercritical fluid?

A supercritical fluid is a gas that has reached its critical temperature and pressure. When a substance is pushed to these conditions it loses its ability to differentiate between liquid and gas phases and has properties of both.

The density of a supercritical fluid can be manipulated by varying the pressure. It also has the solvent power of a liquid and can diffuse rapidly. This makes it useful for extracting organic materials such as coffee beans and flowers.

Carbon dioxide (scCO2) is the most common supercritical fluid used in industrial applications. Its mild critical temperature and relatively low pressure make it ideal for use with thermally labile samples. It is also environmentally friendly, non-toxic and does not contribute to CO2 accumulation in the atmosphere. It is a highly efficient solvent for chemical processes such as textile dyeing and impregnating leather. It can also be used to disperse polymers, improve their flexural properties and reshape them.

What are the benefits of using a supercritical fluid?

SCFs offer a gentle extraction process that eliminates the need for high pressures and harsh chemicals. They can also be used to control the particle size of solid materials – an important feature in many pharmaceutical applications.

Supercritical fluids combine the favourable properties of liquids and gases at once. They have the density of a liquid and the solvating power of a gas. SCFs can be manipulated to change their properties by changing the temperature and/or pressure.

This allows mass transfer to be accelerated, leading to shorter extraction times. It also reduces the degradation of heat labile compounds and provides higher extraction yields. SFE also offers selectivity, ensuring that only the desired compound is extracted and not other undesirable elements. This helps maintain the quality and safety of the final product. SFE can also be performed at mild temperatures, preventing damage to heat sensitive compounds. These benefits make SFE an excellent alternative to conventional solvent extraction methods.

What are the equipment requirements for a supercritical fluid extraction?

Supercritical fluid extraction (SFE) is a treatment alternative to organic solvents that protects extracts from thermal degradation and environmental contamination. It is also less time consuming than traditional methods.

Using a supercritical carbon dioxide solution allows for the rapid and highly selective dissolution of materials without the evaporation steps required in other techniques. This reduces process times, saves energy and produces higher yields than traditional extraction processes.

With the addition of a co-solvent, the diffusivity of the SCF can approach that of a liquid while still maintaining gas properties, thus enabling high selectivity during extraction. This can be achieved by adjusting both temperature and pressure.

Using the BR back pressure regulator in a supercritical CO2 system allows the reactor to maintain its extraction pressure independently of the flow system rate. This avoids the Joules-Thompson effect which can cause ice and extraction oil buildup and blockage in other back pressure control devices. The BR’s flexible diaphragm material allows for virtually any SCF and co-solvent combination to be used.

What are the instrumentation requirements for a supercritical fluid extraction?

Supercritical fluids are created by increasing the temperature and pressure of a substance above its critical point. These dense fluids exhibit the properties of both liquids and gases, diffusing through solids like a gas while dissolving materials like a liquid. SCFs are environmentally friendly, avoiding the use of organic solvents and have a fast mass transfer rate.

Carbon dioxide is a common SCF used in natural products extraction as it has a relatively low critical point, good extraction properties, is available as a gaseous natural state and is safe for handling. The polarity of CO2 can be adjusted by the addition of modifiers such as acetone, methanol or hexane improving selectivity for the analysis of polar compounds.

SFE is a versatile technique that can be used for a range of applications such as decaffeination, production of natural colourants, milk sterilisation and extraction of botanical oils. It is also suitable for the extraction of phytochemicals which have potential nutrient and therapeutic properties.

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