For example, water boils at degrees Fahrenheit, while ethanol boils at degrees Fahrenheit. By heating a water-ethanol mixture to degrees Fahrenheit, you can convert ethanol from a liquid state into a vapor, effectively removing it from the mixture and leaving behind only water. The distillation process occurs in a column — a piece of equipment designed to contain the feed, apply heat to it, condense the volatiles and collect the separated constituents.
In its simplest form, distillation equipment has three basic components:. Depending on the chemical properties of the feed itself and the desired product, the distillation column may differ in terms of its size and diameter, as well as the level of pressure inside the column and the temperature the mixture is heated and cooled to.
As such, distillation columns can become exceptionally more complicated than the simple column described above. Distillation works well on liquid mixtures that have a high relative volatility, meaning there is a significant difference in volatility levels between the product and its contaminants.
Additionally, distillation can be used on any feed that has one or more components, making it useful in industrial settings where many contaminants affect the product. To achieve the purest distillate possible, multiple feed containers can be set up in a row, increasing the concentration levels of the volatile in the mixture at each stage. Building a distillation column that allows for multiple stages of the heat-condense cycle improves the purity of the final product.
The distillation method of liquid separation is more difficult to achieve with mixtures that have a low relative volatility. In this case, specialized techniques are needed to achieve greater precision. Substances with the highest boiling points can never be completely removed from the mixture, and remain as residue in the feed.
In addition to imperfect separation, one of the major downsides to the distillation method is that it consumes enormous amounts of energy during the heating and condensing processes. As a result, the distillation method is less desirable in industrial settings processing high volumes of feed. Additionally, safety experts warn that distillation can be a hazard due to the quantities of pressurized boiling liquid present in the distillation column.
Thermal expansion can occur, which can lead to fire or explosion. What is the difference between stripping and distillation?
While distillation uses heat to boil the volatiles into vapor and then condense and remove them, stripping uses the principles of absorption. Absorption is the chemical process whereby molecules in a bulk phase — either a liquid or solid — are taken into a gaseous substance. When applied in the context of stripping, engineers use steam as the gas that absorbs liquid molecules.
In a steam stripping column, the liquid molecules being separated from the feed get absorbed by the water vapor, effectively isolating them from the desired product. Steam stripping is also sometimes referred to as steam distillation, though distillation is a different chemical process.
Like distillation, steam stripping is also used to remove volatiles like ethanol, methane, benzene or hexane from the feed, particularly in situations where these compounds threaten environmental health and safety, such as water or air pollution.
Where is estimated as follows. Ignore the contribution of the solute to the physical properties of the carrier streams and assume a vapor flooding velocity of 3.
Assume a foaming factor of 0. Assume a tray spacing of 24 inches. What is according to. We will use maximum hole diameter. The weirs have a height of 2. What is the pressure drop per tray? The SlideShare family just got bigger. Home Explore Login Signup. Successfully reported this slideshow. We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads.
You can change your ad preferences anytime. Absorption and Stripping - mass transfer. Upcoming SlideShare. Like this presentation? Why not share! Embed Size px. Start on. Show related SlideShares at end. WordPress Shortcode. Next SlideShares. Download Now Download to read offline and view in fullscreen. Download Now Download Download to read offline. What is Absorption 3. What is Stripping 4. Absorption is a chemical process where atoms, molecules or ions enter a bulk phase which is a liquid or a solid material.
This process is different from adsorption because, in adsorption, the atoms, molecules, or ions adhere onto the bulk surface, whereas in absorption, atoms, molecules or ions enter into the bulk material.
However, the term sorption covers both absorption and adsorption processes, as well as the ion-exchange process. The absorption process refers to a substance being captured and the transformation of energy. In this process, the bulk material that captures the components is absorbent, and the components that are being captured are absorbates.
Similarly, in the adsorption process, the corresponding terms are adsorbent and adsorbate. There are different types of absorption processes, such as chemical absorption and physical absorption.
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