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Solvent Extraction The problem with using solvents to extract essential oils is that most of the time, residual solvents or impurities remain in the end product. This rapid extraction method uses lower temperatures and higher pressure to transform carbon dioxide, a gas, into a liquid. When the extraction process is complete, the carbon dioxide is returned back to a gaseous state therefore, no residual remains. www.aromanaturals.net /solvent-extraction.htm   (568 words)

Extraction article - Extraction chemistry mixture solubility solvents solute vegoil immiscible - What-Means.com   (Site not responding. Last check: 2007-09-26) Liquid-liquid extraction is based on the transfer of a solute substance from one liquid phase into another liquid phase according to the solubility. In medicine, extraction is the surgical removal of a tooth from the mouth. Simple extractions may be done by a dentist; more complicated extractions are usually performed by an oral surgeon. www.what-means.com /encyclopedia/Extraction   (176 words)

Extraction -- Facts, Info, and Encyclopedia article   (Site not responding. Last check: 2007-09-26) Liquid-liquid extraction is based on the transfer of a (The dissolved substance in a solution; the component of a solution that changes its state) solute substance from one liquid phase into another liquid phase according to the solubility. Simple extractions may be done by a (A person qualified to practice dentistry) dentist; more complicated extractions are usually performed by an oral (A physician who specializes in surgery) surgeon. Extraction may imply the rescuing of entities from grave danger or immediate conditions that they are incapable of surviving within. www.absoluteastronomy.com /encyclopedia/e/ex/extraction.htm   (332 words)

Chemical Extraction Chemical extraction is a process that separates contaminants from soils and thereby reduces the volume of the hazardous waste that must be treated. Solvent extraction uses an organic solvent, to remove metals and mixtures of metal and organic compounds. Solvent extraction is used to treat soils containing organic contaminants such as SVOCs, VOCs, and fuels, as well as metals. www.cpeo.org /techtree/ttdescript/chemex.htm   (437 words)

A Citizen's Guide to Solvent Extraction   (Site not responding. Last check: 2007-09-26) Solvent extraction is a treatment technology that uses a solvent (a fluid that can dissolve another substance) to separate or remove hazardous organic contaminants from sludges, sediments, or soil. Solvent extraction can be both an effective and cost efficient process for separating hazardous contaminants from non-hazardous materials and concentrating the hazardous materials for further treatment. Solvent extraction has been shown to be effective in treating sediments, sludges, and soils containing primarily organic contaminants, such as polychlorinated biphenyls (PCBs), volatile organic compounds (VOCs), halogenated solvents (solvents containing halogens, which are bromine, chlorine, or iodine), and petroleum wastes. www.p2pays.org /ref/07/06190   (1510 words)

Armfield - Batch Solvent Extraction and Desolventising Unit - FT29 Extraction by recirculating miscella This involves priming the miscella tank with clean solvent then pumping the solvent to the extractor where it percolates through the material bed and drains as miscella back into the tank for recirculation. When the extraction is complete, the static hold-up of solvent remaining in the material must be removed and this is achieved using a combination of direct and indirect steam and vacuum. The solvent vapourises and is condensed along with the direct steam and the condensate mixture of solvent and water is separated and stored in the solvent water separator tank. www.armfield.co.uk /ft29_datasheet.html   (1161 words)

solvent extraction in precious metal refining In some cases if solvent extraction is governed by an irreversible chemical reaction of the solute with other components in the solvent the process can be performed in a stirred tank reactor as a batch mixer-settler process. In cases if solvent extraction is enabled by a chemical reaction (at the interphase of aqueous/organic or in one or both of the bulk phases) or if a prevailing chemical reaction is accelerating the basic physical mass tranfer, this process is called reactive extraction. the solubilities of solvents and extractants in the aqueous liquids are of superior importance; during solvent extraction system design in the lab phase extractant/solvent combinations must be selected comprising as low aqueous solubility as possible; otherwise those chemicals might be harmfull to the environment. www.haltech.de /solvent-extraction.htm   (1364 words)

Microwave-Assisted Extraction and Accelerated Solvent Extraction with Ethyl Acetate-Cyclohexane before Determination of ...   (Site not responding. Last check: 2007-09-26) Focused open-vessel microwave-assisted extraction (FOV—MAE), closed-vessel microwave-assisted extraction (CV—MAE), and accelerated solvent extraction (ASE) were used for extraction before determination of organochlorine compounds (polychlorinated biphenyls, DDT, toxaphene, chlordane, hexachlorobenzene, hexachlorocyclohexanes, and dieldrin) in cod liver and fish fillets. Extractions were performed with the solvent mixture ethyl acetate—cyclohexane (1 + 1, v/v), which allowed direct use of gel-permeation chromatography without solvent exchange. For this reason, the extraction procedure for wet fish tissue required 2 extraction steps: the first for manual removal of coextracted water, and the second for quantitative extraction of the organochlorine compounds with the pure solvent. www.aoac.org /pubs/JOURNAL/2000/Nov_Dec/Microwave_Assisted.htm   (257 words)

[No title]   (Site not responding. Last check: 2007-09-26) Solvent extraction systems reduce the toxicity and volume of contaminated material by solubilizing and removing contaminants from the waste matrix and concentrating them in oils in the solvent recovery systems. The ability of solvent extraction systems to reduce the toxicity or volume of contamination at a site is assessed based on the following considerations: Reduction in toxicity of contaminated material Reduction in volume of contaminated material Irreversibility of treatment Each of these considerations is addressed below. Solvent extraction does not remove metals from wastes; therefore, treatment of wastes containing metals above the TCLP standards may produce treated solids that exceed RCRA TCLP standards or that may pose a risk at the site. www.copa.org /bbs_file/fs4474.txt   (391 words)

Solvent extraction of copper, nickel with methyl hexyl dioxime - Patent 4248837 In the recovery process, the dioxime dissolved in the solvent forms a complex with the metal to be extracted, which complex is soluble in the organic solvent. The solvent for the dioximes in the second series was a mixture of 50% amyl alcohol and 50% kerosene, the solvent for LIX 64N was kerosene. Extraction rates were measured as the number of shakes required for complete extraction of copper from an aqueous solution. www.freepatentsonline.com /4248837.html   (3424 words)

Solvent extraction in limited coalescence processes - Patent 5580692 Multiple stage extraction is advantageous when a large amount of extracting liquid is required to complete the extraction step (e.g., when the extracting liquid and the dispersant have relatively low mutual miscibilities or in relatively large scale production). Continuous extraction is performed, for example, by providing a continuous stream of extracting liquid that mixes with a continuous stream of the suspension. In addition, the extraction methods can also be used to perform an initial, bulk removal of dispersant with the remaining dispersant removed by conventional means such as evaporating, vacuum drying, or oven drying. www.freepatentsonline.com /5580692.html   (6174 words)

Vol.13 - 6. Rendering As with the shift from batch to continuous processing, the decline in the use of solvent extraction in the late 1970s has been suggested as a contributing factor in the emergence of the BSE epidemic. When solvent extraction was common, small rendering plants often concentrated on the production of tallow, selling their greaves to other processors for further processing and grinding. In particular, a movement away from solvent extraction seems to have been a common factor worldwide, and certainly the main equipment manufacturers sold their models throughout the world. www.bseinquiry.gov.uk /report/volume13/chapted3.htm   (2324 words)

SX Kinetics, Inc. - Specialists in Solvent Extraction: List of Projects Manufactured a bench scale solvent extraction and electrowinning pilot plant for the recovery of copper for an ore body in Russia. The process utilized two solvent extraction circuits: The primary circuit used Primine JM-T extractant for the recovery tantalum, and the secondary used a mixture of DEHPA and Cyanex 923 for the recovery of uranium and scandium. Solvent extraction for the separation of cobalt from nickel was evaluated. www.sxkinetics.com /projects.htm   (3135 words)

Air Assisted Solvent Extraction   (Site not responding. Last check: 2007-09-26) Abstract: Solvent extraction using a solvent coated bubble (air assisted solvent extraction) is introduced. Coating of a bubble with an organic solvent consisting of 3 v/v% (di-(2-ethylhexyl)-phosphoric acid) DEHPA in kerosene is shown to be thermodynamically favourable and is demonstrated experimentally. Aset up to generate a single stream of solvent coated bubbles is described. pubs.nrc-cnrc.gc.ca /cmq/27742-3.html   (151 words)

[No title]   (Site not responding. Last check: 2007-09-26) Worker Safety The solvents used in extraction are not considered hazardous; however, they must be stored in appropriate containers with secondary containment. Air emissions from solvent extraction would be minimal because the process basically operates in a closed loop. The results of air monitoring conducted during solvent extraction demonstration tests indicate that air emissions would not be a significant problem. www.copa.org /bbs_file/fs4475.txt   (567 words)

Clean Solvent Extraction Using Polyethylene Glycol-Based Traditional solvent extraction employs partitioning of a solute between two immiscible phases, typically an organic solvent and an aqueous solution. Further, liquid/liquid extraction is capable of large volume throughput and is amenable to large-scale separations, and can be engineered for high selectivity and efficiency by the use of multistage contactors. ABS retain all of the practical advantages of liquid/liquid extraction and also have a number of unique advantages due, in large part, to their aqueous nature. bama.ua.edu /~rdrogers/webdocs/cleansx.html   (1054 words)

Caustic Side Solvent Extraction   (Site not responding. Last check: 2007-09-26) The basic principle of solvent extraction (liquid-liquid extraction) is to use a sparingly soluble diluent material that carries an extractant that will complex with cesium ions in the caustic solution. Following cesium extraction, the solvent is scrubbed with dilute caustic to remove other salts from the solvent stream (in the Scrub Stages). The solvent is then contacted in a countercurrent flow with a dilute acid stream to transfer cesium to the acid stream (in the Strip Stages). www.srs.gov /general/outreach/srs-cab/ShortList/CSSE.htm   (206 words)

Lipid extraction, general methods Several extraction procedures may be found in books and articles aiming at the improvement of lipid recovery from any kind of organisms, tissues or cell types. After the first famous studies of Chevreul on the dissolution of lipid materials in various solvents, it is necessary to jump to 1879 when Franz von Soxhlet described the first method based on an automatic solvent extraction (diethyl ether) for milk lipids (Die gewichtsanalytische Bestimmung des Milchfettes, Dingler's Polytechnisches J 1879, 232, 461). Soft tissues may be minced with scissors in the cold and homogenized in solvent with an Ultraturax type device, a Warring blender or a glass-Teflon Potter. www.cyberlipid.org /extract/extr0002.htm   (588 words)

Pressurized Solvent Extraction   (Site not responding. Last check: 2007-09-26) Traditional extraction techniques use large amounts of solvent and require lengthy extraction periods to remove the analytes from the sample matrices. Pressurized solvent extraction uses reduced quantities of conventional solvents at elevated temperatures (50-200°C) and pressures (1,500-3,000 psi) to rapidly extract analytes from their sample matrices. If the solvent reaches its boiling point (Tbp) and turns into a gas, it is no longer capable of dissolving compounds, dropping efficiency to zero. www.crescentscientific.com /pse2.htm   (183 words)

Solvent Extraction Plants Sizes of vapour lines is an important safety factor in designing a solvent extraction plant. Similarly, though the entire process of solvent extraction is carried out in totally enclosed equipment, it is necessary to connect them directly or indirectly to a final vent so that no undesirable pressures are created inside the equipment. Therefore, the operators of the solvent plant must be instructed to close the main steam supply valve to the plants as soon as the power fails. www.mecpro.com /solvent-proc2.htm   (602 words)

Aromatherapy , Extraction Methods , Solvent Extraction   (Site not responding. Last check: 2007-09-26) Solvent extraction uses very little heat so it's able to produce essential oils from plants whose fragrance would be destroyed or altered during steam distillation. Solvent extraction is used almost exclusively on delicate plants and produces higher amounts of essential oils at a lower cost than could be achieved by enfluage. The solvent is then boiled off under a vacuum or in a centrifugal force machine to help separate it from the oil. www.itselixir.com /public/page.cfm?CatID=619   (347 words)

Solvent Extraction Notes Solvent Extraction is an important tool in the analytical laboratory. Cell membranes can be viewed as an organic solvent into which compounds can partition and a compounds lipophillicity can be a crucial factor in the compounds ability to pass into the cell. We removed more for the aqueous phase but each added extraction would end up spreading the extracted substance into more and more volume and the ratios of a two compound system would stay fixed and the relative amounts of A and B would remain the same. www.rit.edu /~lprsch/scha312ext_a.html   (2828 words)

Killing Three Birds With One Stone: A Solvent Extraction Strategy. Extraction and stripping tests of a candidate solvent for Cs extraction alone and for combined Cs, Tc, and Sr have so far been successfully conducted on a batch scale on actual Hanford DSSF waste. Results of PNNL tests of the same solvent on Hanford DSSF show in Table 2 that Cs and Tc may be extracted and stripped successfully from actual waste; Sr was present at insignificant levels and was not reliably measured in the test. It is proposed for FY 1999 to begin development of a solvent suitable for the combined extraction of Cs and Sr from SBW and DCW. www.ornl.gov /sci/casd/csg/TEMtank.html   (2283 words)

ARS | Publication request: Evaluation of Accelerated Solvent Extraction (Ase) for Analysis of Pesticide Residues in Soil In addition, large amounts of solvents are often needed, and their purchase and waste disposal further add to the overall cost of sample analysis. Technical Abstract: Accelerated solvent extraction, or ASE, is a new extraction technique that is similar in principle to Soxhlet extraction, but the use of elevated temperature and pressure with ASE allows the extraction to be completed within a short time and with a small quantity of solvent. In this study, we investigated the effect of residue aging, solvent type, and ASE conditions on the recovery of atrazine and alachlor from different soils, and compared the efficiency of ASE with that of Soxhlet and solvent- shake extractions. www.ars.usda.gov /research/publications/publications.htm?SEQ_NO_115=103401   (340 words)

4-15 Chemical Extraction Solvent extraction is a common form of chemical extraction using organic solvent as the extractant. Solvent extraction has been shown to be effective in treating sediments, sludges, and soils containing primarily organic contaminants such as PCBs, VOCs, halogenated solvents, and petroleum wastes. Traces of solvent may remain in the treated solids; the toxicity of the solvent is an important consideration. www.frtr.gov /matrix2/section4/4-15.html   (1251 words)

Amazon.ca: Books: Solvent Extraction in Biotechnology   (Site not responding. Last check: 2007-09-26) Solvent Extraction in Biotechnology deals with the recovery and purification of primary and secondary metabolites by solvent extraction. Several practical examples are given for the recovery of different metabolites as well as for the calculation of the extraction processes necessary for equipment design. Besides solvent extraction, novel separation techniques with liquid membrane, microemulsion and reversed micelles are also presented. www.amazon.ca /exec/obidos/ASIN/0387576940   (361 words)

lipid extraction If hexane is the most commonly used solvent, isohexane appears to be the most likely candidate to replace n-hexane as the preferred oilseed extraction solvent, mainly in USA to avoid federal environmental regulations applying to the use of n-hexane. The lipid sample is dissolved in the same solvent mixture and 2.5 ml are applied to the column followed by 5 ml of the same mixture, 2.5 ml of chloroform / methanol (2/1) and finally by 2.5 ml of chloroform / methanol / water (48/35/10). Evaporation of solvents: When a large amount of solvent must be evaporated, it should done in a rotary film evaporator, the flask containing the extract being maintained at no more than 50°C with a water bath. www.cyberlipid.org /extract/extr0001.htm   (2287 words)

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