Continuous flow gas

The above equations can be used to predict the output 1/ in the effluent from a continuous-flow gas-liquid contractor. Let the flow rate of phase a be F. Then, a macroscopic balance at a steady state leads to the equation ... 

Brain tissue Homogenization in coid 0.01 M NaOH. Centrifuge and resuspend pellet add zinc acetate and ascorbic acid readjust pH use continuous flow gas dialysis system to separate sulfide. Gas dialysis/ion chromatography with ECD 0.02 pg/g 95-100% Goodwin et al. 1989... 

Since oxygen is a substrate, Vmax and Km are functions of the oxygen concentration co2> which is fixed by Po2 in the continuously flowing gas phase. At low values of CG, the reaction is pseudo-first-order with respect to glucose, and (A) simplifies to... 

Continuous-flow gas anesthesia system (2Biological Instraments, Besozzo, Italy). 

A continuous flow gas anesthesia system is used to deliver isofiurane to the mice. The mice are placed in an induction chamber for initial anesthetization and then supplied the gas... 

Tundo, P. and Selva, M. (2005). Continuous-flow, gas phase synthesis of 1-chlorobutane (1-bromobutane) from 1-butanol and aqueous HCl (HBr) over silica-supported quaternary phosphonium salt. Green Chem., 7,464-467. 

For example, little is known about the isotopic composition of formaldehyde in the atmosphere. Formaldehyde is a chemical intermediate in hydrocarbon oxidation. The carbon (8 C) and hydrogen (8D) isotopic composition of atmospheric formaldehyde is analyzed using continuous flow gas chromatography isotope ratio mass spectrometry." Isotope ratios were measured using GC-IRMS (Finnigan MAT 253 stable isotope ratio mass spectrometer, single-sector field with electron impact ion source and multiple ion collection) with a precision of 1.1 and 50%(lo ) for 8 C and 8D, respectively. The accuracy of the online continuous flow isotope technique was verified by calibrating three aliquots of the gas phase standard via the offline dual inlet IRMS technique. The concentration of formaldehyde in ambient air was determined on IRMS major ion peak areas (i.e., mass 44 for 8 C and mass 2 for 8D)." ... 

The apparatus for open-tube diffusion consists of a silica furnace tube with a continuously flowing gas. The exit end may be at atmospheric pressure or at reduced pressure. The impurity source may be a vaporizing solid whose vapors are carried to the semiconductor by a carrier gas. The carrier gas may be bubbled through a liquid impurity source. The carrier gas takes up source molecules, which then decompose at elevated temperatures. Liquid sources are maintained at or near room temperature. This arrangement has an advantage over the use of solid sources in terms of easier control of source temperature and, thus, impurity concentrations in the carrier gas. 

I Ls can also be immobilized by impregnation of an inorganic support. This is a direct transposition of the Supported Aqueous-Phase Catalysis (SAPC) concept to ionic liquids (see Section 2.6). Supported Ionic Liquid Phase (SILP) catalysts containing Rh-biphosphine ligands were applied to perform continuous-flow gas-phase hydroformylation of propene in [BMIMJIPFg] or [BMIMJIRSOJ (R=octyl). 

Similar results were recently published for the continuous-flow gas-phase hydroformylation of propene [51]. This time, the supported system was prepared by direct impregnation of an unmodified silica gel with methanol solution containing [Rh(CO)2(acac)j, the ligand, and the IL. The sulfonated xantphos used in this investigation must be added in large excess (10-20 equiv. per Rh) to afford the expected selectivity for the linear aldehyde n/i = 16.9). The performance of the optimized catalytic support remains stable up to 5 h before a decrease in activity and selectivity was observed. This work was also completed using other ligands derived from the series developed in classical biphasic IL systems, and applied to the continuous hydroformylation of propene and 1-octene [52]. 

Other advantages of the tubular reactor relative to stirred tanks include suitability for use at higher pressures and temperatures and the fact that severe energy transfer constraints may be surmounted readily using this configuration. The tubular reactor is usually employed for liquid phase reactions when relatively short residence times are needed to effect the desired chemical transformation. Tubular reactors are the configuration of choice for continuous flow gas phase operations. 

Monomer (I) is synthesized from hexafluoroacetone and ethylene oxide in four steps as shown in Scheme 16.2 [8], Monomer (I) is a colorless liquid with a boiling point of 33°C and has a high polymerization reactivity. Monomer (H) is synthesized by the following continuous-flow, gas-phase process (Scheme 16.3). It is also a colorless liquid with a boiling point of 30-32°C. 

Let us consider a semibatch reactor with a continuously flowing gas phase. The liquid phase is assumed to remain in batch. If the gas flow rate is zero, then the reactor is converted into aBR. 

Fig. 2.12 Schematic diagram of the Quantachrome continuous flow gas chromatographic apparatus.

Dimethyl carbonate can be used for methylation of nitrogen in amine compounds at a temperature of 180°C under continuous-flow gas-liquid phase-transfer catalysis conditions (which involve transfer of organic ionic reactant species between water and an organic phase) as shown below for the methylation of aniline ... 

For reductive amination of acetone with ammonia two types of catalysts were designed (i) skeletal Ni catalyst prepared form a Ni-Al alloy and Ci) its tin modified versions. Both types of catalysts were used in a continuous flow gas phase reactor. The requirements for these catalysts were as follows high thermal and mechanical stability, high rates for the formation of both primary and secondary amines and suppression of the formation of isopropyl alcohol from acetone. 

The hydrodechlorination of chlorobenzene, and conversion 4-chlo-ro-2-nitrQ-aniline to orthophenylenediamine was carried out under different reaction conditions using stirred tank and trickle bed reactors in the pressure range of 1-70 bar. The reductive amination of acetone was studied in a continuous flow gas phase reactor at 20-50 bar and 1B0-2DQ°C. Both in the hydrodehalogenation and reductive amination the reaction products were analysed by gas chromatography. ... 

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