Membranes Reflux

Reflux overhead vapor recompression, staged crude pre-heat, mechanical vacuum pumps Fluid coking to gasification, turbine power recovery train at the FCC, hydraulic turbine power recovery, membrane hydrogen purification, unit to hydrocracker recycle loop Improved catalysts (reforming), and hydraulic turbine power recovery Process management and integration... 

Sol-gel is one of the most useful techniques for preparation of inorganic membranes with fine pores in the nanometer range (1-5 nm). The sol is a stable suspension of colloidal solid particles within soft uniform solution. The gel was obtained by hydrolysis with open reflux in 24 hours at 85-90 °C. The advantage of sol-gel technology is the ability to produce... 

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The IPE functionalized membranes were generated as an intermediate step to obtaining the PA functionalized films. Our attempts to hydrolyze the MPE to the PA group were not successful, however the IPE was successfully converted to the acid form. To synthesize the acid form, the IPE functionalized membranes were refluxed in concentrated (37 wt%) hydrochloric acid for 17 hours. 

Figure 19.6. Gas permeation equipment and performance, (a) Cutaway of a Monsanto Prism hollow fiber module for gas separation by permeation, (b) Flowsketch of a continuous column membrane gas separator, (c) Composition profiles of a mixture of C02 and Oz in a column 5 m long operated at total reflux [Thorman and Hwang in ( Turbak, Ed.), Synthetic Membranes II, American Chemical Society, Washington DC, 1981, pp. 259-279],...

Molecular weight determinations were carried out osmometrically on a Hitachi Perkin Elmer model 115 molecular weight apparatus with the complex dissolved in benzene and at 38°C (the lowest possible temperature). The isomerization was followed by GLC analysis (Perkin Elmer model 11, Squalane column). The desired amount of the complex was placed in a reaction flask which was then flushed with N2. Benzene and 1-hexene which had been degassed by refluxing over sodium in an N2-atmosphere, were injected through a membrane attached to the flask. Samples were removed through the membrane and injected immediately into the gas chromatograph. 

Figure 9.19 Fraction of benzene in permeate as a function of feed mixture composition for pervaporation at the reflux temperature of a binary benzene/cyclohexane mixture. A 20-qm-thick crosslinked blend membrane of cellulose acetate and polystyrene phosphate) was used [54]. Reprinted with permission from I. Cabasso, Organic Liquid Mixtures Separation by Selective Polymer Membranes, Ind. Eng. Chem. Prod. Res. Dev. 22, 313. Copyright 1983 American Chemical Society...

To perform a dialytic extraction, the apparatus is assembled and preextracted for 48 hours using pyridine and methylene chloride outside and inside the membrane, respectively. The coal ftvlOO g) is then slurried in a 2-3 fold excess of pyridine (ACS reagent grade) and placed in the sample compartment, where it is constantly stirred. The methylene chloride reflux is begun at this point, and the extract collects in the receiver. When the buildup of pyridine in the receiver results in stoppage of the reflux cycle, the contents of the receiver are collected, and it is refilled with clean methylene chloride. The overflow from the sample compartment was evaporated under a flow of dry nitrogen, redissolved in pyridine, and replaced in the sample compartment daily. The dialytic extraction is slower than the soxhlet procedure, and the yield is substantially less. For example, the yield of a four day dialytic extraction of Powhatan Coal was 6%, while a two day pyridine soxhlet on the same coal yields 12-15% extract. 

Ultrafiltration, 631 applications, 633 membranes, 637-639 Underwood minimum reflux binaty, 387 multicomponent, 397 Units, conversion of, 671, 672 UMQUAC equation, 475 Upflow fixed beds, 609 Uranium recovery, 515 Utilities, typical characteristics, 15... 

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