Volume recovery process

Figure 2. Volume recovery process of poly (vinyl acetate) after a sudden cooling fromTi = 313 KtoTf = 303 Kfor different gravity parameter ag where curves A, B and C are for ag = 0,5 (A), 5,0 (B) and 15,0 (C), respectively and Vf is the final volume at 7 = 303 K for ag = 0...

Figure 3 shows the volume recovery process after a sudden cooling for three different values of Op where the initial and final temperature are, respectively, Ti = 313 K and Tf = 303 K. The curves A, B and C are for otp = 2 x 10, 4 X 10 and 8 x 10", respectively. Basically from Figure 3 we note that the curves show similar variation except that the final constant value of V depends on oCp, and with larger otp we get a higher value of V implying a slower relaxation. For the range of otp studied in our analysis V can be enhanced by almost 50 %. 

Most by-product acetylene from ethylene production is hydrogenated to ethylene in the course of separation and purification of ethylene. In this process, however, acetylene can be recovered economically by solvent absorption instead of hydrogenation. Commercial recovery processes based on acetone, dimetbylform amide, or /V-metby1pyrro1idinone have a long history of successfiil operation. The difficulty in using this relatively low cost acetylene is that each 450, 000 t/yr world-scale ethylene plant only produces from 7000 9000 t/yr of acetylene. This is a small volume for an economically scaled derivatives unit. 

Process Dewatering Applications RO is usebil in many small appheations where there is a volume of water containing a small amount of contaminant. RO is often able to recover most of the water at a purity high enough for reuse. The waste is concentrated making its disposal less costly, which generally pays for the recovery process. 

M. Knickrehm, E. Caballero, P. Romualdo, and J. Sandidge. Use of chlorine dioxide in a secondary recovery process to inhibit bacterial fouling and corrosion. In Proceedings Volume. NACE Corrosion 87 (San Francisco, CA, 3/9-3/13), 1987. 

As with all process equipment, the design size of an evaporator system is dependent upon volumetric flow, specifically the rinsewater flow rate required and the volume of process solution dragout. When operated properly, a commercial evaporator can attain a 99% material recovery rate. 

Recent research and field tests have focused on the use of relatively low concentrations or volumes of chemicals as additives to other oil recovery processes. Of particular interest is the use of surfactants as CO (184) and steam mobility control agents (foam). Also combinations of older EOR processes such as surfactant enhanced alkaline flooding and alkaline-surfactant-polymer flooding have been the subjects of recent interest. Older technologies polymer flooding (185,186) and micellar flooding (187-189) have been the subject of recent reviews. In 1988 84 commercial products polymers, surfactants, and other additives, were listed as being marketed by 19 companies for various enhanced oil recovery applications (190). 

Increasing the water-wet surface area of a petroleum reservoir is one mechanism by which alkaline floods recover incremental oil(19). Under basic pH conditions, organic acids in acidic crudes produce natural surfactants which can alter the wettability of pore surfaces. Recovery of incremental oil by alkaline flooding is dependent on the pH and salinity of the brine (20), the acidity of the crude and the wettability of the porous medium(1,19,21,22). Thus, alkaline flooding is an oil and reservoir specific recovery process which can not be used in all reservoirs. The usefulness of alkaline flooding is also limited by the large volumes of caustic required to satisfy rock reactions(23). 

Several factors affect the overall economics of PHA production. These include PHA productivity, PHA content, yield of PHA on carbon source, carbon substrate cost, and recovery method employed. Figure 1 shows the production costs of P(3HB) by various P(3HB) contents and P(3HB) productivities [29]. The effect of P(3HB) productivity on the production cost is only related to the cost of the fermentation equipment [18]. However, the P(3HB) content has multiple effects on the volume of the fermentation equipment and the recovery process [17,18]. The increase of P(3HB) yield on carbon source and the use of less expensive carbon substrates reduce the cost of carbon substrate [17, 29]. Development of an efficient recovery method, which will be different for each bacterium employed, is also important to overall economics of PHA production. When the actual fermentation processes employing many different re-... 

Reaction of K3Co(CN) with PMMA. A 1.0 g sample of PMMA and 1.0g of the cobalt compound were combined in a standard vessel and pyrolyzed for 2 hrs at 375°C. The tube was removed from the oven and the contents of the tube were observed to be solid (PMMA is liquid at this temperature). The tube was reattached to the vacuum line via the break-seal and opened. Gases were determined by pressure-volume-temperature measurements on the vacuum line and identified by infrared spectroscopy. Recovered were 0.22g of methyl methacrylate and 0.11 g of CO and C02. The tube was then removed from the vacuum line and acetone was added. Filtration gave two fractions, 1.27g of acetone insoluble material and 0.30g of acetone soluble (some soluble material is always lost in the recovery process). The acetone insoluble fraction was then slurried with water, 0.11 g of material was insoluble in water. Infrared analysis of this insoluble material show both C-H and C-0 vibrations and are classified as char based upon infrared spectroscopy. Reactions were also performed at lower temperature, even at 260°C some char is evident in the insoluble fraction. 

Figure 2.2-1 illustrates how arsenic wastewater flows through that facility. The first three arsenic sources were thought to be minor and composed of soluble araenic. These waste streams flow directly to the HF preholding tank and are not involved in the Slurry Recovery process. Sample acquisition for these sources required the operator to perform the wash process in a container with graduations on the sides for volume measurement. Samples were taken after the processes were completed. Arsenic analysis waa done on the measured wash solution and with this analysis and the number of ingots or wafers cleaned or etched, a total arsenic contribution was calculated. 

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