Analysis of the product gas

Figure 3.1 shows a typical laboratory flow reactor for the study of catalytic kinetics. A gas chromatograph (GC, lower shelf) and a flow meter allow the complete analysis of samples of product gas (analysis time is typically several minutes), and the determination of the molar flow rate of various species out of the reactor (R) contained in a furnace. A mass spectrometer (MS, upper shelf) allows real-time analysis of the product gas sampled just below the catalyst charge and can follow rapid changes in rate. Automated versions of such reactor assemblies are commercially available. 

The analysis of the product gas, calculated to a hydrogen-free basis, is shown in Table II. The high percentage of methane and the predominance of n-butane and n-pentane over the branched compounds suggest that they were produced by a thermal cracking reaction with hydrogenation of the olefins. 

A GC or an MS is used for analysis of the product gas. The unit described in Fig. 2 is largely controlled by a PC/Labview application via an interface controller... 

A gas turbine power plant receives a shipment of hydrocarbon fuel whose composition is uncertain but may be represented by the expression Cj Hy. ITie fuel is burned with excess air. An analysis of the product gas gives the following results on a moisture-free basis 10.5%(v/v) CO2, 5.3% O2, and 84.2% Nj. 

If liquid-petroleum gas (LPG) is used as a feedstock, the two gases propane (CsHg) and butane (C4H10) must be monitored. Analysis of the product gas can be performed by gas chromatography (GC). The experimental results lead to two conversion values, one for propane and the other for butane ... 

Gas chromatographic analysis of the product on a 1-m column packed with 20% Silicone SE-30 at 180°C should give a single peak. The product has the fallowing spectral properties IR (film) cm" 1710, 1630 (C=C) ... 

Gas chromatographic analysis of the product (1.5 m. by 0.5 cm. glass column, KF-54 on Chromosorb W, 60-80 mesh) showed a single peak with a retention time of 2.60 minutes at 170°. 

Gas chromatographic analysis of the product showed two major peaks (relative intensity, 5 1), and the mass spectrum of each peak revealed a molecular ion at i/e 210. The proton magnetic resonance spectrum of the mixture showed that the two products were geometrically isomeric esters. 

The analysis of the neutral gas composition in a discharge yields useful information on the mechanisms and kinetics of silane dissociation. However, it should be borne in mind that with mass-spectrometric analysis one only detects the final products of a possibly long chain of reactions. 

The stability of molecules depends in the first place on limiting conditions. Small, mostly triatomic silylenes and germylenes have been synthesized successfully at high temperatures and low pressures, 718). Their reactions can be studied by warming up the frozen cocondensates with an appropriate reactant, whereas their structures are determined by matrix techniques 17,18). In addition, reactions in the gas phase or electron diffraction are valuable tools for elucidating the structures and properties of these compounds. In synthetic chemistry, adequate precursors are often used to produce intermediates which spontaneously react with trapping reagents 7). The analysis of the products is then utilized to define more accurately the structure of the intermediate. 

The heatpipe reformer process concept for hydrogen-rich syngas production. (Reproduced from Karellas, S., Metz, T., Kuhn, S., and Karl, J., Online analysis of the tar content of the product gas from biomass gasification. Application on the BIOHPR. 14th European Biomass Conference Exhibition, Biomass for Energy, Industry and Climate Protection, ETA-Renewable Energies, Paris, 2005. With permission.)... 

C30 oil, homopolymer of 1-decene, Ethyl Corp., Inc.) served as the start-up solvent for the experiments. The catalyst (ca. 5-8 g) was added to start-up solvent (ca. 300 g) in the CSTR. The reactor temperature was then raised to 270°C at a rate of l°C/min. The catalyst was activated using CO at a space velocity of 3.0 sl/h/g Fe at 270°C and 175 psig for 24 h. FTS was then started by adding synthesis gas mixture (H2 CO ratio of 0.7) to the reactor at a space velocity of either 3.1 or 5.0 sl/h/g Fe. The conversions of CO and H2 were obtained by gas chromatography (GC) analysis (HP Quad Series Micro-GC equipped with thermal conductivity detectors) of the product gas mixture. The reaction products were collected in three traps maintained at different temperatures—a hot trap (200°C), a warm trap (100°C), and a cold trap (0°C). The products were separated into different fractions (rewax, wax, oil, and aqueous) for quantification by GC analysis. However, the oil and the wax (liquid at room temperature) fractions were mixed prior to GC analysis. 

Furthermore, it is sometimes questionable to use literature data for modeling purposes, as small variations in process parameters, reactor hydrodynamics, and analytical equipment limitations could skew selectivity results. To obtain a full product spectrum from an FT process, a few analyses need to be added together to form a complete picture. This normally involves analysis of the tail gas, water, oil, and wax fractions, which need to be combined in the correct ratio (calculated from the drainings of the respective phases) to construct a true product spectrum. Reducing the number of analyses to completely describe the product spectrum is one obvious way to minimize small errors compounding into large variations in... 

Gas chromatographic analysis of the product from three consecutive preparations showed less than 0.1% impurity. Similar results were obtained on 0.005-ml. samples in an F. and M. 202 Temperature Programed Gas Chromatograph using two columns a 12-foot column of 10% HiVac grease and 5% Marlex-50 on 100-140 mesh Gas Chrom A, at a constant temperature of 275°, with a helium flow rate of 120 ml. per minute and a 20-foot column of 20% GE-SE 30 on 100-140 mesh Gas Chrom A, programed at 3.3° per minute from 250° to 300°, with a helium flow rate of 120 ml. per minute. 

For gas chromatographic analysis of the products, the submitter used a 3 ft. x 0.125 in. stainless steel column of 5% LAC-446 (cross-linked diethylene glycol-adipic ester) on Diatoport S (60-80 mesh), which was heated at 140° and swept with prepurified nitrogen at 30 ml. per minute. The four isomers were observed as three peaks at retention times of 3.08, 3.69, and 4.07 minutes. The checkers used aim. x 4 mm. glass column of 10% DECS on Gas Chrome Q (60-80 mesh), which was heated at 200° and swept with prepurified nitrogen at 75 ml. per minute. 

The analysis of the water gas so far given enumerates the chief constituents, but in reality there are traces of other products, such as carbon bisulphide, carbonyl sulphide, and thiophene, derived from the sulphur in the uel, which, minute in quantity, may nevertheless in the certain chemical processes produce appreciable and un-iesirable results from the iron contained in the fuel, ninute amounts of iron carbonyl are formed, which in nost processes in which water gas is used is a matter jf no importance, but if the gas is to be used for ighting with incandescent mantles, its removal is de-.irable. 

Gas chromatographic analysis of the product shows that the product is at least 99.2% pure and is contaminated only with trace amounts of cyclohexanol. The submitter reported a 62-69% yield (15.7-17.5 g.) using the indicated scale. 

Gas chromatographic analysis of the product (Hewlett-Packard fused silica, cross-linked methyl silicone capillary column, 25 m x 20 mm, column temperature 100-270°C, injection temperature 250°C) shows that the product is over 99% chemically and isomerically pure, (Z,E)-l-Phenyl-l,3-octadiene shows the following spectral properties IR (neat) cm 1640, 1595, 1490, 985 ... 

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