EXTRACTION PROCESSING INDUSTRIAL CHEMISTRY CLASS : XII SEMESTER : 5

The Extraction  Extraction is the separation of a substance mixed with a substance solute division between the two solvent which can not be mixed to take the substance solute from one solvent to another solvent.  Often a mixture of solid and liquid materials can not be separated or exacting method with mechanical or thermal separation that have been discussed.

 For instance, because the components are mixed with each other very closely, is sensitive to heat, different physical attributes too small, or in concentrations that are too low. In such a case. that, extraction is often the only process that can be used or that may be most economical.  As an example of making ester (essence) for the odor syrup or in making perfume, the caffeine from tea leaves, coffee beans or cacao bean and can be seen that day-to-day is solution components using coffee with hot water from the coffee beans that have been burned or grinding Teknologi dan Rekayasa

The terms in the general extraction  Material extraction: Mixed material extracted  solvent (extraction medium): a fluid used to perform extraction  Extract: Materials separated from the extraction  solvent extracts: solvent processes extracts after

 Refined (extraction residue): Material taken after extraction  Extractor: extraction tool  solid-liquid extraction: Extraction, from the solid material  liquid-liquid extraction (solvent extraction with solvent extraction =): Extraction of the liquid extraction Teknologi dan Rekayasa

Kinetics of extraction  It is important to investigate the rate at which the solute is transferred between the two phases, in some cases by an alteration of the contact time it is possible to alter the selectivity of the extraction.  For instance, the extraction of palladium or nickel can be very slow because the rate of lagan exchange at these metal centre is much lower than the rates for iron or silver complexes.

Aqueous completing agents  If a completing agent is present in the aqueous phase then it can lower the distribution ratio.  For instance, in the case of iodine being distributed between water and an inert organic solvent such as carbon tetrachloride then the presence of iodide in the aqueous phase can alter the extraction chemistry.

 Instead of being a constant it becomes = k[[I2.Organic]]/[I2.Aqueous] [[I-.Aqueous]]  This is because the iodine reacts with the iodide to form I3-. The I3- anion is an example of a anion which is quite common. Teknologi dan Rekayasa

 An organic MTBE solution is extracted with aqueous sodium bicarbonate solution. This base removes benzoic acid as benzoate but leaves non-acidic benzil (yellow) behind in the upper organic phase.

Simple laboratory-scale extraction apparatus

Tools of the laboratory-scale extraction column

Small-scale industry extraction apparatus

The process of extraction  In the extraction does not occur immediately from the separation of materials that will be obtained, (extracts), but initially only going collection extract (in solvent).  After the extraction process is complete, is often required other stages. In the solid- liquid extraction can be pre-processing (diminution) material extraction or processing of information refined (with the goal of getting back remains of solvent).

Extraction steps  mix the material with the solvent extraction and leaving mutual contact. In this case, the mass movement occurs with the diffusion in the field of the interface material and solvent extraction. Thus happens to the actual extraction, the extracts solution. Separating solvent extracts from refined, most with a cleaning or filtration. extracts from the isolate solution extract and recover solvent, is generally carried out with solvent vapor.

Preparing materials to be extracted and solvent  Selectivity  Solubility  Separating ability with each other  Density  Reaktivity  Boiling point  Because almost no solvent that meets all the requirements above, then for each extraction process must be sought the most suitable solvent.

Selectivity  Solvent can soluble extract only the desired, not the other components of extraction.  In practice, especially in the extraction of natural materials, often also other materials (such as fat, resin) be involved together with the extract as desired.  In the case of the solvent extracts tercemar that must be cleaned, for example, that is extracted again with the second solvent.

Solubility  Wherever possible solvent has the ability to extract large melarutkan (needs less solvent).

Ability is not mixed with each other  In the liquid-liquid extraction, solvent can not (or only a limited) dissolved in the material which being extracted.

Density  Especially in the liquid-liquid extraction, there are considerable differences in density between the large and solvent extraction.  This meant that the second phase can be easily separated again after the mixing (separation with gravity).  When different density small, often a separation must be done by using the centrifugal force (in centrifugal extractor).

Reactivity  In general, solvent should not cause chemical changes in the components material extraction.  Conversely, in the things required of a specific chemical reaction (such as the formation of salt) to obtain a high selectivity.

 Extraction is also often accompanied by chemical reaction.  In this case the material will be separated absolutely must be in the form of a solution. Teknologi dan Rekayasa

Boiling point  Because the solvent extracts and usually must be separated with the evaporation, distillation or rectification, the second point.  Material that can not be too close, and they do not form azeotroph. Reviewed in terms of the economy, will benefit if the process of extraction solvent boiling point is not too high (as was the case with the evaporation of a low heat).

Other Criteria  Wherever possible should be solvent  Cheap  Available in large numbers - not toxic  Unable to burn  No explosive when mixed with air - not corrosive  Not cause terbentuknya emulsion - have a low viskositas  Stable in chemical and thermal.

Solvents  Water  Organic acid and inorganic  Saturated hydrocarbons  Toluen  Carbon disulfida,  Ether,  Aseton,  Hydrocarbons containing chlor,  Isopropanol,  Ethanol.

Multistage extraction  Extraction akan more beneficial if implemented in a number of stages that many. Each stage uses a little solvent.  loss are: the concentration of solvent extract the longer the lower, and the total amount of solvent needed to be large, so that the solvent to get back into high costs.

Solid-liquid extraction  In the solid-liquid extraction, one or more components that can be separated from the dissolved solid material with the help of solvent.  This process is technically used in large scale, especially in the field of industrial and natural foods.  For example, to obtain the active ingredients from plants or organs - organs of animals for pharmaceutical, sugar from tubers, oil from seeds, and coffee from the coffee beans

Extractors Tools continuous extraction is not usually continuous and is part of a complete installation, consisting of:  Tools for early processing (size diminution, drying) material extraction  Extractor the actual  Equipment to separate (with the cleaning or filtering) from the solvent extract refined (often integrates with extractor)  Tools to isolate or extract to increase the concentration of solvent extract and recover solvent (with the evaporation).

Extractor Basket  In extractor basket (basket turn rotary extractor), the extraction constant is inserted in the cells in the segment (sector) of a rotor that rotates slowly encircle axis.

 The bottom of the cells is closed by a sieve plate. During a round, solid material from the opposite direction drabble by solvent or solvent extracts of concentration increased. Teknologi dan Rekayasa

 Solvent or solvent is pumped from cell to cell and sprinkle to the top of the solid material. Finally, the material is removed and the entire process take place automatic. Teknologi dan Rekayasa

Belt extractor  In this extractor, material extraction is fed continuously above the belt around the sieve.  Along the belt drabble by solvent or solvent extracts increased with the concentration and flow the opposite direction.  Once the material is removed from ekstrakor.

Liquid-liquid extraction  In the liquid-liquid extraction, one or more of the components of an inseparable mixture with the help of solvent.  This process is technically used in large scale such as to obtain the vitamins, antibiotics, materials odor, oil product and salt-salt. metal.  The process used to clean the very day of waste water and solvent extracts of solid liquid extraction.

 Liquid-liquid extraction is used especially when the separation of the mixture with distilation ways not possible (for example, because the formation isotropy or kepekaannya because of the heat) or not economical.  As the liquid-solid extraction, liquid- liquid extraction always consist of at least two stages, is intensively mixing the materials with solvent extraction, and separation of the second liquid phase that may perfect Teknologi dan Rekayasa

Batch liquid-liquid extractor  Materials repeatedly extraction liquid is mixed with fresh solvent in a tank mixer (preferably with the outlet at the bottom).  Solvent extracts generated each time separated by a rarefaction (the influence of gravity).

 The construction process more profitable for the mixing tank and separation is that the lower taper (which is equipped with a gear mixer, under the distributor, and glass visual spread on the entire height).  Tools not continuous as simple as it used to prepare material for example in small large, or if only occasionally performed extraction. Teknologi dan Rekayasa

Continuous liquid extractor  Operation in continuous liquid-liquid extraction can be carried out with simple, because not only solvent, but also the extraction liquid can be flowed easily with the help of pumps.  In this material extraction repeatedly mixed with the solvent or solvent extract in the opposite direction of concentration constantly increasing.

Extraction Column  Similar as known in the rectification or adsorption, in a vertical column extraction of solvent extraction and liquid mutual conducted with the opposite flow direction.  With the help of pumps, liquid that is lighter is inserted from the bottom, and a heavy liquid from the top of the column continuously.  In a column in a process that occurs repeatedly, the mixing between the intensive. second liquid mass movement that happens.

 Events that followed as much as possible with a perfect separation of the second phase.  However, in the field, this process is the extraction and often no longer can be distinguished. Teknologi dan Rekayasa

 Field phase boundary between heavy and light phase is located on the top edge or bottom edge (known through the experiment).  Position maintained by a constant the higher the surface, controlling the discharge of the heavy phase. Teknologi dan Rekayasa

Caring Extractor  Care of equipment for the extraction will be influenced by several factors related to the extraction rate.  If the diffusion of liquids to be taken (solute) on the solid particles is the controlling factor, particles should be small, so that the distance berdifusi substances solute to be small.

Factors influence extractor care 1.Size particles 2.Solvent substances 3.Temperature 4.Mixing of fluids

Particle Size  Size of particles affect the extraction rate in some cases.  The small size, the larger the surface of solid wide & liquid; transfer so that the rate becomes large.  With in other words, the distance to berdifusi experienced by substances in solute solids is small.

Solvent  Solution that would be used as a solvent substances should be the best choice of solvent and low viscosity to circulation easily.  Usually, the solvent pure oxygen will be used initially, but after the extraction process ends, the concentration of oxygen solute will extraction pace up and down, because the first  Find and concentration will be reduced because the two substances solution become more viscous.

Temperature  In many cases, oxygen solubility solute (in the extracted particles) in the solvent will increase along with increase in temperature provide for the extraction rate is higher.

Mixing of fluids  Mixing on oxygen because the solvent is shelter will increase the process of diffusion, so that the transfer of material from the surface particles to solvent oxygen.

Care for equipment "leaching" There are three processes that need to be at the time of treatment equipment leaching occurs:  Solution between solvent substances with substances solute  Separation of solid substances solute  Washing solid to separate substances-substances that do not want or to get results as much as possible