Carbon dioxide transmission

Carbon dioxide transmission rate (CO2TR) mmol cm/ cm hkPa Test temperature = 273-298 K various types of mLLDPE 8-50 (xlO- ) (38, 39)... 

The permeability - water vapor, oxygen, and carbon dioxide - of polylactide nanocomposites reinforced with MMT, was affected using two types of MMT (Cloisite 30B and Nanofil 2), with the addition of two organic modifiers (poly(methyl methacrylate) and ethylene/vinyl alcohol copolymer) and two compatibilizers (PCL and poly(ethylene glycol)). Zenkiewicz and Richert [287] found that Cloisite 30B decreased the film permeability much more than Nanofil 2 and that all the modifiers and compatibilizers reduced the carbon dioxide transmission rate, while only the modifiers reduced the transmission rates of water vapor and oxygen. 

Aydinly, M. Tutas, M. (2000). Water sorption and water vapour and carbon dioxide transmissions of cellulose-based edible films. Lebensm. Wiss. U. Technol, 33(1), 63-67... 

The effect of plasticizers and temperature on the permeabiUty of small molecules in a typical vinyUdene chloride copolymer has been studied thoroughly. The oxygen permeabiUty doubles with the addition of about 1.7 parts per hundred resin (phr) of common plasticizers, or a temperature increase of 8°C (91). The effects of temperature and plasticizer on the permeabiUty are shown in Figure 4. The moisture (water) vapor transmission rate (MVTR or WVTR) doubles with the addition of about 3.5 phr of common plasticizers (92). The dependence of the WVTR on temperature is a Htde more comphcated. WVTR is commonly reported at a constant difference in relative humidity and not at a constant partial pressure difference. WVTR is a mixed term that increases with increasing temperature because both the fundamental permeabiUty and the fundamental partial pressure at constant relative humidity increase. Carbon dioxide permeabiUty doubles with the addition of about 1.8 phr of common plasticizers, or a temperature increase of 7°C (93). 

Atmospheric attenuation is the consequence of absorption of radiation by the medium present between emitter and receiver. For thermal radiation, atmospheric absorption is primarily due to water vapor and, to a lesser extent, to carbon dioxide. Absorption also depends on radiation wavelength, and consequently, on hie temperature. Duiser approximates transmissivity as... 

Hotthl., H.C. and Mangf.lsdorf, H.G. Trans. Am. Inst. Chem. Eng. 31 (1935) 517. Heal transmission by radiation from non-luminous gases. Experimental study of carbon dioxide and water vapour,... 

Land/atmospheric interfacial processes which impact climate and biological activity on earth are illustrated in Figure 3. Emissions of carbon dioxide, methane, nitrogen dioxide, and chlorofluorocarbons (CFCs) have been linked to the transmission of solar radiation to the surface of the earth as well as to the transmission of terrestrial radiation to space. Should solar radiation be an internal process or an external driver of the hydrologic cycle, weather, and air surface temperatures Compounds of sulfur and nitrogen are associated with acidic precipitation and damage to vegetation, aquatic life, and physical structures. 

Carbon dioxide gas (CO2) exhibits a set of relatively strong absorption bands at approximately 2 pm, which coincides with the infra-red edge of the transmission band of silica optical fibres (see Figure 6). These absorption... 

Figure 3 is the absorbance spectrum of a sample of the ambient laboratory air drawn into the cell. Here, in accord with the usual procedure, the initially determined spectrum was first corrected for radiation that had reached the detector without having passed through the sample (room temperature background radiation entering the optical path via imperfect optical components and nonoverlap of the source and detector pupils and fields), ratioed against a zero-sample spectrum, and converted to absorbance. Trace (A) shows the spectrum from 3600-600 cm l. The massive absorbances seen here truncated at 1% transmission are due to water vapor and to carbon dioxide. 

A powerful characteristic of the cell described above is the opportunities it affords for the determination of the compositions of both the lower (denser) and upper (lighter) phases. In particular, the combination of ATR and transmission IR spectroscopy shows the distribution of the catalyst between the two phases. For example, in the homogeneously catalyzed formylation of morpholine with carbon dioxide and hydrogen by a ruthenium catalyst, a two-phase system was found at a... 

The facilities on this combined drilling and production plotform are designed to produce ond treot the reservoir fluid which contains up to 4% carbon dioxide ond is saturated with water vapour, so that the gas and hydrocarbon liquids can be sofely transmitted to shore without corroding the transmission pipeline. 

Polymers Mixed by Milling. The effect of EVA concentration in the blends on gas permeation and light transmission through the film was studied. The permeability and the diffusion coefficients at 50 °C for the penetrants helium, argon, and carbon dioxide are shown in Figures 1, 2,... 

Liquefied natural gas (LNG) is a very clean fuel in that the few impurities present in natural gas (water vapor, hydrogen sulfide, carbon dioxide, particulates and foreign matter, etc.) are removed almost completely when the natural gas is liquefied. Liquefaction also removes most of the hydrocarbons heavier than propane so that the resulting fuel is 95-99% methane with the remainder being primarily ethane with a smaller amount of propane. The liquefaction process is so efficient at removing contaminants that it removes the odorant placed in natural gas for transmission over pipelines (natural gas odorants are primarily mer-captans which contain sulfur and are relatively large molecules). 

The application of malonyl-a-aminopyridine (37) was claimed in shampoo as a coupler (81GEP3009833). The 3-butyl derivative of malonyl-a-aminopyridine (694, R = Bu) inhibited senescence of illuminated soybean seedlings under low carbon dioxide conditions, but did not decrease leaf light transmission at ambient carbon dioxide levels (84MI14). 3-Arylazo derivatives of malonyl-a-aminopyridine (694, R = Ar—N= N—) are used as dyestuffs, and the effect of the substituents of the aryl ring on the color of azo dyes was investigated (89MI6). 

Pannell and coworkers34 described the use of poly(ferrocenylsilanes) as coatings in optical fiber gas sensors. In these devices a small change in refractive index of the polymer film results in a large change in the optical transmission of a tapered optical fiber. This is useful for remote sensing of ammonia or carbon dioxide. Polymers of type 6.20 with R/R = Me/Ph and copolymers from monomers with R/R = Me/Ph and Me/Me were found to be effective for this application. 

Standard Reference Material 1470 is a 23 micrometer thick polyester film whose gas transmission characteristics with respect to helium, carbon dioxide, oxygen, and nitrogen have been carefully measured. A completely computerized manometric permeation measuring facility developed at NBS was used for the measurements. The steps taken to characterize the gas transmission rate of this material over the range of pressures from 67.5 kPa to 135 kPa and over the range of temperatures from 18 °C to 31 °C are described. The results obtained in these measurements are compared with those in the literature. The role of Standard Reference Material 1470 in improving the repeatability and reproducibility of gas transmission measurements employing other instrumentation is discussed. 

Depending on source, geographic location, and the extent of extraction, the acid gas content of fuel gases often exceeds pipeline specifications. Certain natural gases and landfill gases can contain up to 50% carbon dioxide. Bulk removal of both carbon dioxide and hydrogen sulfide from such sources, i.e., the process of sweetening, not only improves the fuel value of the gas, but also helps reduce corrosion of pipelines and transmission equipment. Membranes are suitable for this application especially where the scale is relatively small and the economics favor scalable membrane systems. 

The H/C ratio of the coke deposits was quantified by temperature programmed oxidation (TPO) in a 1 % oxygen helium mixture. Temperature was raised to 850° C at a heating rate of 10° min 1. The calculations of the H/C ratio involved the results from the measurements of carbon dioxide production and oxygen uptake (according to Ref. [8]). Coke deposits were also characterized by thermogravimetry and transmission electron microscopy. 

If the natural gas stream contains unacceptable quantities of hydrogen sulfide and/or carbon dioxide, they must be removed in order to make the gas suitable for transmission and sale. The details of removal of H2S and C02 from natural gas streams are beyond the scope of this chapter, but excellent discussions are available.10,12 There are many different processes available, depending upon the contaminants to be removed and their concentration in both the sour gas available and the sweetened gas to be produced. The dominant treating process is still the use of an alka-nolamine. A typical flow diagram for an amine sweetening installation for removal of hydrogen sulfide and carbon dioxide from a natural gas stream is shown in Fig. 20.10.12... 

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