Pressure extraction system

The pressure extraction system (see Fig. 5.1) is operated as follows. The quantity of petroleum from each oil well (produced with the natural layer pressure) is serially measured using an automatic group measurement unit. Then, the petroleum from various oil wells in the field is transported to the local separation station. The quantity of the petroleum from the oil wells is measured after the preliminary gas separation with the centrifugal separator. After that, the petroleum and gas are directed to a local separation unit, where gas is separated from the petroleum by the first stage separator at the pressure 4—5 bar and then directed to the gas processing station. Petroleum with layer water and solved gases will be pumped to the central processing station, where the second step of separation 

Marcel Dekker, Inc. 270 Madison Avenue, New York, New York 10016 

This pressure extraction system is completely hermetically sealed. Therefore it excludes loss of gas and light petroleum fractions. The pressure extraction system allows for petroleum preparation at a central processing station for oils from several oil wells located in an area up to a 100-km radius. However, long distances for petroleum transport can lead to the creation of stable emulsions. With high humidity of the petroleum, this can lead to an increase in operations and transport costs. Nevertheless, it is one of the promising systems of petroleum extraction that is widely applied. 

There are many technological schemes for petroleum preparation. However, technical and economic considerations determine which scheme is used and the location of installation. It is known that the lowest capital investment and operational costs for petroleum preparation are for installations in locations of the greatest petroleum concentration (collector stations, commodity parks, and head offices). 

The optimal technological scheme for petroleum preparation is obtained with a scheme that allows petroleum to be processed to the allowable contents of water and salts, and with the necessary depth of stabilization at the lowest costs, in the shortest possible process time. 

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Hood entry loss The pressure drop (energy loss) that occurs due to turbulence at the entrance to the extraction system. 

Fire authorities may stipulate pressurization of certain areas such as stairways and may require smoke-extract systems to be brought into operation automatically in the event of a fire. They should be consulted at an early stage of the design. 

When using any solvent extraction system, one of the most important decisions is the selection of the solvent to be used. The properties which should be considered when choosing the appropriate solvent are selectivity distribution coefficients insolubility recoverability density interfacial tension chemical reactivity viscosity vapour pressure freezing point safety and cost. A balance must be obtained between the efficiency of extraction (the yield), the stability of the additive under the extraction conditions, the (instrumental and analyst) time required and cost of the equipment. Once extracted the functionality is lost and... 

For dust extraction systems, the concentration of solids usually is quite low. For this reason, the methods employed to calculate pressure loss are based on air-only conditions. Comprehensive information is available (ASHRAE, 1985 ACGIH, 1992) to assist the designer in estimating the pressure loss caused by pipe branches, ducts, elbows, etc. 

Pressure-relieving systems are unique compared with other systems within a chemical plant hopefully they will never need to operate, but when they do, they must do so flawlessly. Other systems, such as extraction and distillation systems, usually evolve to their optimum performance and reliability. This evolution requires creativity, practical knowledge, hard work, time, and the cooperative efforts of the plant, design, and process engineers. This same effort and creativity is essential when developing relief systems however, in this case the relief system development must be optimally designed and demonstrated within a research environment before the plant start-up. 

McLoughlin, D.A., Olah, T.V., and Gilbert, J.D. 1997. A direct technique for the simultaneous determination of 10 drug candidates in plasma by liquid chromatography/atmospheric pressure chemical ionization mass spectrometry interfaced to a Prospekt solid-phase extraction system. J. Pharm. Biomed. Anal. 15 1893. 

Several points need to be considered when applying this pressure method of sample collection. All of the extraction system parts must be explosion proof and the distance from the ceramic cup to the sample bottle must be as short as possible. The sample collection bottle should be at the same level as the ceramic cup. If it is higher, additional vacuum will need to be applied to move the sample water into the sample bottle. Sample storage, once the water is collected, is determined by the analyte of interest. 

The costs of three sizes of a proprietary dual-phase extraction system were estimated in 1991. The costs associated with Radian International s AquaDetox/SVE system (see summary T0641) are detailed in Table 1. The system uses a moderate vacuum stripping tower and low-pressure... 

Extraction System. The flow-through extraction system used in this study is shown in Figure 1. The system is operable up to 400 bar at 200°C. It consists of solvent delivery systems (Fluid 1, Fluid 2, Fluid 3), a flow-through reactor (FR), a set of separator traps (TP1, TP2), and the temperature and pressure control units. The reactor, traps, micrometering valves, and tubing connections are housed in a heated oven. 

We have demonstrated in this paper that two and four samples can be extracted in parallel with supercritical carbon dioxide without significant impact on data quality. Modifications made to an off-line extractor involved addition of a multiport manifold for the distribution of supercritical fluid to four extraction vessels and of a 12-port, two-way switching valve that allowed collection of two fractions per sample in unattended operation. The only limitation that we have experienced with the four-vessel extraction system was in the duration of the extraction. When working with 2-mL extraction vessels and 50-/zm restrictors, and using the pressure/temperature conditions mentioned above, the 250-mL syringe pump allows us a maximum extraction time of 60 min. During this time, two 30-min fractions can be collected with the present arrangement. 

The robustness of a sample preparation technique is characterized by the reliability of the instrumentation used and the variability (precision) of the information obtained in the subsequent sample analysis. Thus, variations in controlled parameters and sequences are to be avoided. In sample preparation methods employing supercritical fluids as the extracting solvents, it has been our experience that minimal variations in efficient analyte recoveries are possible using a fully automated extraction system. The extraction solvent operating parameters under automated control are temperature, pressure (thus density), composition and flow rate through the sample. The precision of the technique will be discussed by presenting replicability, repeatability, and reproducibility data for the extraction of various analytes from such matrices as sands and soils, river sediment, and plant and animal tissue. Censored data will be presented as an indicator of instrumental reliability. 

A hot water dynamic extraction device was constructed using the solubilization apparatus of Miller and Hawthorne (10) as a model and was used for pressurized extraction of milk thistle seed meal. Figure 2 shows a schematic diagram of the apparatus. Water, the extraction solvent, was pressurized and pumped using a Bio-Rad 2800 HPLC solvent delivery system (Hercules, C A) to an extraction cell housed in the oven of a Hewlett-Packard 5890 gas chromatography (GC) oven (Wilmington, DE). Before... 

One of the extraction vessels is equipped with a temperature and pressure sensor/control unit. Figure 3.10 shows the schematic diagram of a control vessel as well as a standard vessel. A fiber-optic temperature probe is built into the cap and the cover of the control vessel. The standard EPA method requires the microwave extraction system to be capable of sensing the temperature to within +2.5°C and adjusting the microwave field output power... 

The solid sample is placed in the preheated extraction thimble, and the modified CO2 is added to the desired extraction pressure. The system is held static at the extraction temperature and pressure. At the end of the period, the system is vented into a collection vial containing chloroform. This is followed by a dynamic flush of the system with the CO2 solvent at the same temperature and pressure. Mercury complexed with fluorinated diethyl-dithiocarbamate was extracted from dried aquatic plant material with 95% efficiency by methanol-modified CO2. 

With the need to provide PCR-amplifiable DNA, multiple approaches for incorporation of the extraction protocol onto microchips were examined. Recent development includes the implementation of a solid-phase extraction of DNA on a microchip [49]. The extraction procedure utilized was based on adsorption of the DNA onto bare silica. The silica beads were immobilized into the channel using a sol-gel network. This method made possible the extraction and elution of DNA in a pressure-driven system. 

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