Extraction of liquids

Experiments have been carried out on the partitioning of aromatics between gasoline and diesel and superheated water [84]. The increase in the partition coefficient between ambient and 200°C was —10 for benzene, toluene, ethyl benzene and xylenes and -60 for naphthalene, for example. This behavior could be the basis of a process for the removal of benzene from gasoline in particular, and for the removal of aromatics from petroleum products in general. 

There are two major challenges in the technique. The first is that if the effluent from the column needs to be cooled before entering the detector, the coiled tubing 

Superheated water extraction has been coupled to superheated chromatography both on line [97] and offline with an intermediate sorbent concentration step [98]. Mixtures with other solvents have been used at high temperatures, such as dimethyl sulfoxide [99] and methanol [100]. Superheated deuterium chromatography has been used so that it could be coupled to NMR spectroscopy [101]. 

Hawthorne, D.J. Miller, A.J-M, Laga-dec, P.p Hammond andA.A. Clifford, 

Gallagher and G.S. Kell, NBS/NRC Steam tables. Hemisphere Publishing, Washington, DC, 1984. 

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Sometimes an air bubble enters the tube E and prevents the regular flow of liquid from B the air bubble is easily removed by shaking the rubber tube. The flask A is heated (e.g., by a ring burner) so that distillation proceeds at a rapid rate the process is a continuous one. If the liquid to be steam distilled is lighter than water, the receiver must be modified so that the aqueous liquors are drawn off from the bottom (see Continvmia Extraction of Liquids, Section H, 44). 

Selected Adsorbents for Solid-Phase Extraction of Liquid Samples... 

Supercritical fluid solvents have been tested for reactive extractions of liquid and gaseous fuels from heavy oils, coal, oil shale, and biomass. In some cases the solvent participates in the reactions, as in the hydrolysis of coal and heavy oils with water. Related applications include conversion of cellulose to glucose in water, dehgnincation of wood with ammonia, and liquefaction of lignin in water. 

The terms oil production and gas production refer to rates of extraction of liquid and gaseous hydrocarbon materials from natural underground deposits. Reserves and resources, on the other hand, refer to amounts of oil and gas that are present in the deposits, the difference between reserves and resources being whether or not the amounts can be economically recovered under current conditions. Supply refers to the amount of a product that becomes available for... 

Some commercial cylinders are provided with an eductor tube, which allows the extraction of liquid ammonia when the cylinder is... 

SFE has been used extensively in the analysis of solid polymers. Supercritical fluid extraction of liquid samples is undertaken less widely because dissolution or entrainment of the matrix can occur. As illustrated elsewhere SFE has also been applied for the analysis of liquid poly(alkylene glycol) (PAG) lubricants and sorbitan ester formulations [370]. The analysis of PAG additives (antioxidants, biocides and anticorrosion, antiwear and antifoaming agents) is hindered by the presence of the low molecular weight PAG matrix (liquid) and therefore a method for the selective separation of additives from PAG is required. The PAG... 

Combalbert S, Pype ML, Bemet N, Hemandez-Raquet G (2010) Enhanced methods for conditioning, storage, and extraction of liquid and solid samples of manure for determination of steroid hormones by solid-phase extraction and gas chromatography-mass spectrometry. Anal Bioanal Chem 398 973-984... 

Conglomerate, 25 Congruent melting point, 29 Congo red, 979 Conjugate solutions, 17-20 Consolute temperature, 17, 18, 19, 20 Continuous extraction, of liquids by solvents, 152-154... 

Continuous extractions of liquids. When the organic compounds is more soluble in water than in the organic solvent (i.e. the distribution coefficient between the organic solvent and water is small), very large quantities of organic solvent must be employed to obtain even a moderately efficient extraction. This may be avoided by the use of an apparatus for continuous extraction where only relatively small volumes of solvent are required. 

Extraction of solid samples Homogenization extractions Sonication extractions Microwave assisted extractions Soxhlet extractions Accelerated solvent extractions Supercritical fluid extractions Extraction of liquid samples Liquid-liquid extractions Solid phase extractions (SPE)... 

POROCRITICAL FLUID EXTRACTION A NEW TECHNIQUE FOR CONTINUOUS EXTRACTION OF LIQUIDS WITH NEAR-CRITICAL FLUIDS. Marc Sims, James R. Robinson and Anthony J. Dennis, (Marc Sims SFE, Setec Inc., Tastemaker), 1012 Grayson... 

A new supercritical fluid process has been developed for the continuous extraction of liquids. The most useful solvent employed in the recently patented process is supercritical or near-critical carbon dioxide(l). At the heart of the process are porous membranes. Their porosity combined with a near-critical fluid s high diffusivity create a dynamic non-dispersive contact between solvent and feed liquid. The technique is dubbed porocritical fluid extraction and will be commercialized as the Porocrit Process. 

The turn-key multipurpose high pressure pilot unit shown in picture 1 can be used for the continuous extraction of liquid products in a column with structured packings and for the batch extraction of solids in a extraction vessel. It is assembled using the following proven basic modules (see also figure 1) ... 

The use of supercritical fluids in extraction processes has become well established. Until now, the extraction of liquids, as for example vitamins or vegetable edible oils, has been carried out in countercurrent columns. Dense gases offer several advantages over conventional solvents such as selective dissolving power, reduced thermal stress of the products or its physiological harmlessness. A supercritical fluid also has a density close to those for liquids, the viscosity is nearly 100 times lower and the diffusivity is up to 100 times higher than those of ordinary liquids as can be seen in table 1. 

A New Design of a Multi-Purpose Plant for Extraction of Liquids with Supercritical Fluids... 

As reported in a lot of reviews, extractions with supercritical solvents have a very promising commercial potential. Until now the commercialization is mainly restricted to batchwise extraction of solids with carbon dioxide (e g. decaffeination of coffee and tea, extraction of hop). Laboratory experiments and operation of small-scale pilot plants gave favourable economic values for continuous extraction of liquids with C02 and other gases. Only a few extractions with C02 or C HS are performed already on a small industrial scale. For research purposes and product development a new high pressure counter-current extraction plant was erected. To get greater amounts of product the explosionproof plant was constructed in pilot scale using a special modular concept and an effective visual control system. 

Lastly, the shape of the vessel does not appear to have an influence on the efficiency of the extraction, although some practical considerations such as the ease of filling the vessels needs to be taken into account. The SFE of liquid matrices, on the other hand, is technically problematic. A vessel permitting the extraction of liquid matrices is today commercialized by Jasco (Hachioji, Japan). 

Adams, R.P., M.F, Balandrin, K.J. Brown, G.A. Stone, S.M. Gruel (1986) Extraction of Liquid Fuels and Chemicals from Terrestrial Higher Plants, 1. Yields from a Survey of 614 Western U.S. Plant Taxa, Biomass 9 255-292. 

The design of a multi-purpose plant for the continuous extraction of liquids with supercritical fluids is presented. To provide flexibility in order to treat different feedstocks, a modular concept was developed based on experience gained in the operation of bench-scale and pilot plants. Four test systems were chosen in order to determine the proper dimensions for the equipment. Based on experimental data, e.g. measurements of flooding points and maximum flows for various column internals, the design pressure and temperature and heat exchange requirements were determined. The plant was built by a German manufacturer and was operated successfully by a Canadian company in Edmonton, Alberta. 

Separation by Centrifugal Force.—The three possible separations which can be made by centrifugal machines are (1) The extraction of liquids from solid material, such as textiles, fibers, leather, crystals, etc. Examples of this mode... 

Truly continuous is the extraction of liquids if the extractor is replaced by a column. The liquid is pumped continuously onto the head of the pressurised column and flows down by gravity. Supercritical fluid extraction is normally operated in the so-called droplet regime and not in the film regime. This means the liquid in contact with the... 

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