Reactor Varian

All reactions involving lactic acids were performed in 300 mL Parr Autoclave batch reactor. All reagents, including the resin catalyst, were charged into the reactor and heated up to the desired reaction temperature. Stirring was commenced once the desired temperature was reached this was noted as zero reaction time. Reaction sample were withdrawn periodically over the course of reaction and analysed for ester, water and alcohol using a Varian 3700 gas chromatograph with a thermal conductivity detector (TCD) and a stainless steel... 

The transformation of cyclopentanol-cyclohexanone mixture was carried out in a fixed-bed reactor at 200°C and 250°C under atmospheric pressure and in the presence of nitrogen (nitrogen/reactant molar ratio = 4). The reactant was an equimolar mixture of cyclopentanol and cyclohexanone. The reaction products were analyzed on line by GC (VARIAN 3400 chromatograph, equipped with a SGE CIDEX B 25 m x 0.22 mm column and a flame ionization detector). The deactivation profile was obtained by analyzing reaction effluent for various times-on-stream (TOS). 

The activity of calcined HTs was determined in self-condensation reaction of acetone (J.T. Baker) by using a fixed bed catalytic reactor with an on-line GC. Prior to the catalytic test, catalysts were pretreated in-situ under nitrogen atmosphere at 450°C for 5h. Acetone was supplied to the reactor by bubbling nitrogen gas through the acetone container at 0 °C. The reaction temperature was established at 200 C. The products were analyzed by means of GC (Varian CP-3800) using a WCOT Fused silica column, equipped with a FID detector. 

Catalytic activities for n-hexane cracking were performed using an isothermally operated flow reactor. The feed stream of nitrogen was saturated at 3°C with hexane. With the help of a bypass it was possible to determine both the reactor inlet and outlet concentration of hexane using a gas chromatograph (Varian Star 3400) with FID-detector. 

The gases left the reactor at the bottom and flew to a 4-way valve. The tubes after the reactor were heated with heating jackets (60-80°C). The products were either analysed on-line or collected in a condenser for off-line analysis (Varian 3400 gas chromatograph with a packed column, 10% OV-17 on chromosorb W detector TCD). 

DA, MEK, methyl vinyl ketone (MVK), propionaldehyde (PrH), and acetaldehyde (AcH) were analysed by on-line gas chromatography using a Varian 3400 GC equipped with a thermal conductivity detector and a 2m column containing 25% w/w B.B -oxydipropionitrile on Chromosorb W (80-100 mesh) operated at 60°C He was used as the carrier gas. Acetic acid (AcOH) was collected in 2ml of water from the effluent stream over a period of 1 hour and later analysed on a Porapak QS column at 150°C. CO2 was tested by removal of 2ml samples from the exit of the reactor with a gas syringe and injecting them onto a Porapak QS column operated at 60°C. 

Equipment. A commercial 300 ml magnedrive autoclave (Autoclave Engineers) reactor was used for all reaction studies and has been previously described (3-6). Varian gas chromatographs (Model 920 and 1800) were used for analysis of gas samples and products from the hydrotreating reactions. 

The total sulfur concentration of the coal charged to the reactor and that of the solid product were determined by use of a Fischer Total Sulfur Analyzer. Liquids were analyzed on a Perkin Elmer Sigma 3 gas chromatograph and gas analyses were performed on a Varian Model 3400 gas chromatograph. 

A second approach to a cold wall system is the single-wafer CVD reactor developed by Varian-Torrex. A schematic of the reaction chamber is shown in Figure 25. Again, tungsten silicide is deposited in this cold-wall reactor. Other conducting films such as blanket and selective tungsten can also be deposited. 

Figure 25 Varian-Torrex 5101 single-wafer CVD reactor system.

All product analysis of effluent gas streams was performed by on-line gas chromatography. Two different gas chromatographs were employed, each with heated sample valve connected to the reactor effluent stream. Analysis of light (Ci-C5) hydrocarbons and dimethyl ether was performed by a Varian 1400 GC equipped with flame ionization detector. Separation of the products was accomplished by a 20 column (1/8" O.D.) packed with Porapak Q. Analysis of hydrocarbons in the C5 to... 

The effluent gas composition was determined using a dual column Varian 3700 gas chromatograph. The permanent gases H2, O2, N2, CH, and CO were measured on a Molecular Sieve 13 column H2, CH, CO2, C2H, and C2H on a Chiomosorb 106 column. Aigon was used as a carrier gas. The bed temperature (12 different points) and the reactor pressure were measured continuously. 

Details can be found in Bdlare (ref. 3). The experimental equipment consists of a cumene reservoir, a thermogravimetric analyzer (TGA) and a gas chromatograph (GC). The hdium-cumene mixture enters the TGA, a Cahn System 113DC with a Cahn 2000 Recording Electrobalance, a quartz tubular reactor, and an external split-shell furnace. The catalyst is placed in the sample pan of the microbalance inside the quartz reactor, kept at a controlled temperature in the center of the split-shell furnace. The incremental weight due to coke deposition on the catalyst is monitored by an IBM PC. The reactor exit stream is injected into a Varian 3700 GC using FID. 

The reaction was performed in a batch reactor in an autoclave under 20 atmospheres of hydrogen and at room temperature. A liquid sampler allowed the progress of the reaction to be followed by product analyses. The products were analysed by gas chromatography in a Varian GC-3400 equipped with a capillary column (PONA) allowing the separation of the different reactant and products. 

The thiophene hydrodesulfurization and cyclohexene hydrogenation activity of the catalysts were measured in a high pressure reactor. The experimental conditions for the activity tests were a feedstock of thiophene (15000 ppm), cyclohexane (90%) and cyclohexene (10%), flow rate 0.353 ml/min, total pressure = 26 Kg/cm and LHSV=52 l/h. Additional experiences with toluene (90%) and cyclohexene (10%) were also carried out. The operative conditions for the hydrotreating test were selected according to the recent experience about the C0M06 [3]. The products were analysed by gas chromatography by means of a Varian Start 3400 gas chromatograph, with FID detector. 

Rates of hydrolysis were measured on a Varian Cary 219 UV spectrophotometer equipped with a Haake constant temperature bath. A stirred batch tank reactor was placed in a water bath maintained at 26.0 0.1 C and the solution was transported to a micro flow UV cell located in the spectrophotometer via silicone rubber tubing using a precision flow peristaltic pump (MHRE 22) manufactured by the New Brunswick Scientific Company. 

The Nb-Ti-V-P-O-catalyst was evaluated in a fixed bed microreactor unit described elsewhere [15], modified in such a manner, that all reactor effluent lines were heated to 200 C to prevent condensation of products. The product stream was analyzed by an on-line Varian Model 3600 GC for oxygenates and hydrocarbons and a Carle refinary gas analyzer for the lower hydrocarbons and fixed gases. 

The reactor contained between 0.1 and 0.2 g of catalyst, and was situated inside another section of quartz tubing (12mm i.d.) which was wound with nichrome wire and insulated. The catalyst temperature was monitored by a thermocouple placed between the two quartz tubes. The products of the conversion were analysed by a Varian 3700 gas chromatograph fitted with TCD and FID detectors. The output of both detectors was fed into an apple lie computer for integration and data storage. 

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