Carbon dioxide analyser

This new and novel method to study the photochemical degradation of Kevlar-29 fabric in air divides into four steps (1) fabric cleaning, (2) photolysis at specified temperature and time in 0.2 atm - 02, (3) preparation of the degraded (DMAc-soluble) sample surface for decarboxylation at 25° and 196°C in the concentrated sulfuric acid, and (4) the total carbon dioxide analyses by gas chromatography and the isotopic carbon dioxide ( °C02 and 48co2) ratios by GC-mass spectrometer. 

Carbon dioxide is not a common oxidation product in periodate work, but it does appear in the oxidation of ketoses,49 a-keto acids,14,39 and a-hydroxy acids,14 39 and it is often a product23 141 of overoxidation. Carbon dioxide analyses have been carried out using the Plantefol apparatus,49 the Warburg apparatus,14 23 and the Van Slyke-Neill mano-metric apparatus,39 and by absorption in standard sodium hydroxide141 followed by back-titration with acid. A most convenient method is the very old, barium hydroxide absorption scheme.16 The carbon dioxide is swept from the reaction mixture into a saturated, filtered barium hydroxide solution by means of a stream of pure nitrogen. The precipitated barium carbonate is filtered, dried, and weighed. This method is essentially a terminal assay. The manometric methods permit kinetic measurements, but involve use of much more complicated apparatus. 

Sharp [48] has described a dry combustion-direct injection system built for oceanographic analyses. This unit used 100 xl samples, injected into a 900 °C oven in an atmosphere of oxygen. The output from a non-dispersive infrared carbon dioxide analyser was linearised and integrated. 

The fust of the more sophisticated approaches requires a specialised instrument, the Corning 965 carbon dioxide analyser. 

In a number of surveys, Lovell (1979), Lovell and Hale (1983) and Lovell et al. (1979, 1983) used a Taylor Servomex DA272 oxygen analyser and a Lab-Line 2245 carbon dioxide analyser. These instruments were connected in series and samples of soil air from a probe driven about 1 m into the ground were introduced by means of a hand pump. 

Carbon dioxide analysers, based on heat capacity, electrical conductivity or partial pressure measurements, but especially on IR light absorption, are therefore used at various points in industrial processes. Carbon monoxide and dioxide are the species most commonly analysed for by the last of the above-mentioned detection techniques, which is also employed in a variety of processes [6], namely (a) control of the hydrogenation of plant oils in order to avoid production of unwanted trans isomers (b) measurement of sugars and CO2 In soft drinks (c) measurement of moisture (d) determination of CO2 In Industrial environments (e) determination of isocyanates In the production of polyurethane (f) determination of methane In argon from nuclear plants (g) control of the efficiency of solvent clean-up and recovery systems. 

Carbon dioxide analyses may be done continuously by infrared or more simply, cheaply and reliably by passing a... 

Clearly, the carbon dioxide tax will be a dominant factor in future economic analyses of novel cycles. It would appear that a tax of about 3 c/kg of CO2 produced would make some of the CO2 removal cycles economic when compared to the standard basic cycles. 

Figure 14.7 Typical clnomatogram obtained by using the refinery analyser system shown in Figure 14.6. Peak identification is as follows 1, hydrogen 2, Cg+, 3, propane 4, acetylene 5, propene 6, hydrogen sulfide 6, iso-butane 8, propadiene 9, n-butane, 10. iso-butene 11, 1-butene 12, traw-2-butene 13, cw-2-butene 14, 1,3-butadiene 15, iso-pentane 16, w-pen-tane 17, 1-pentene 18, tro 5-2-pentene 19, cw-2-pentene 20, 2-inethyl-2-butene 21, carbon dioxide 22, ethene 23, ethane 24, oxygen + argon, 25, niti Ogen, 26, carbon monoxide.

The dry analysis is on the basis of the water being removed from the sample prior to analysis, and the maximum theoretical carbon dioxide content is 11.87 per cent. Most flue analyses are carried out on the dry basis. 

Carbon Dioxide Adsorption on Dried Polymer. Other unexpected interactions of these hydrolytic polymers have been noted previously during the measurement of infrared spectra of dried Pu(IV) polymers (like those used for diffraction studies). Vibrational bands first attributed to nitrate ion were observed in samples exposed to room air however, these bands were not present in samples prepared under nitrogen atmospheres (see Fig. 4) (6). Chemical analyses established enough carbon in the exposed samples to confirm the assignment of the extraneous bands to the carbonate functional group... 

Future emissions and concentration of carbon dioxide Key ocean/atmosphere/land analyses. Tech. Pap. 31, Div. of Atmos. Res., Comm. Sci. and Ind. Res. Org., Melbourne, Victoria, Australia. 

In a first set of experiments, the impact of the sodium hydroxide concentration (0.1, 1.0, 2.0 M) and gas-flow direction (co-current, counter-flow) was analysed (50 ml h liquid flow, 65 pm film thickness) [5]. The higher the base concentration, the higher is the conversion of carbon dioxide. For aU concentrations, complete absorption is achieved, but at different carbon dioxide contents in the gas mixture. The higher the carbon dioxide content, the higher is the gas flow velocity and the larger must be the sodium hydroxide concentration for complete absorption. The gas flow direction had no significant effect on carbon dioxide absorption as the gas velocities were still low, so that no pronounced co- or counter-flow operation was realized. 

This reaction serves as a known model reaction to characterize mass transfer efficiency in micro reactors [7]. As it is a very fast reaction, mass transfer can be analysed solely The analysis can be done simply by monitoring color changes from pH indicators. Ammonia absorption in aqueous acidic solutions generally is even faster than carbon dioxide absorption in alkaline solutions. 

Carbon dioxide fugacity (fc02h The /CO2 values can be estimated from (1) gangue mineral assemblages including carbonates and (2) fluid inclusion analyses. 

Carbon dioxide chemisorptions were carried out on a pulse-flow microreactor system with on-line gas chromatography using a thermal conductivity detector. The catalyst (0.4 g) was heated in flowing helium (40 cm3min ) to 723 K at 10 Kmin"1. The samples were held at this temperature for 2 hours before being cooled to room temperature and maintained in a helium flow. Pulses of gas (—1.53 x 10"5 moles) were introduced to the carrier gas from the sample loop. After passage through the catalyst bed the total contents of the pulse were analysed by GC and mass spectroscopy (ESS MS). 

Lehaitre et al. [23] have described a fibre-optic spectrophotometric method for the in situ measurement of biological and chemical species. This instrument can measure phytoplanktonic species, and the potential for chemical measurement such as dissolved carbon dioxide is analysed. 

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