The Transportation of Gases

The transportation of gases may be roughly divided into the problems involving the use of air piped under more or less pressure, those of the removal of waste industrial gases by chimneys, and the carriage of highly-compressed gases in tanks.  

Tempera- ture, degrees Fahren- heit Weight of 1 cu. ft. of dry air (at 14 lb. per square inch or 28.5 in. of Hg.), pounds Increase or decrease of weight for each 0.1 lb. change in pressure, pounds Increase or decrease of weight for each 1 in. of Hg. change of pressure, pounds Decrease of weight for each 10 per cent increase in relative humidity, pounds 

2 Acknowledgment is here made to Marks Mechanical Engineers Handbook and to the Standard Handbook for Electrical Engineers for much of the material in this chapter. The individuals whose work was thus used are H. J. Thorkelson, L. C. Loewenstein, E. E. Williams, Joseph H. Brown, Jr., and R. J. S. Pigott.—Editor. 

General Properties of Gases.—Gases when compressed or expanded isotherm-ally approximately follow the law pv = RmT, where p = pressure, v = volume, R is the so-called gas constant (approximately 0.08207), m the mass of the gas in grams and T the absolute temperature (Boyle s law). A more nearly correct 

Hydrogen sulphide... Hydrogen phosphide. Hydrogen telluride... 

---

Existing methods for monitoring the transport of gases were inadequate for studying aerosols. To solve the problem, qualitative and quantitative information were needed to determine the sources of pollutants and their net contribution to the total dry deposition at a given location. Eventually the methods developed in this study could be used to evaluate models that estimate the contributions of point sources of pollution to the level of pollution at designated locations. 

Buried steel pipelines for the transport of gases (at pressures >4 bars) and of crude oil, brine and chemical products must be cathodically protected against corrosion according to technical regulations [1-4], The cathodic protection process is also used to improve the operational safety and economics of gas distribution networks and in long-distance steel pipelines for water and heat distribution. Special measures are necessary in the region of insulated connections in pipelines that transport electrolytically conducting media. 

How would you design the architecture of a catalyst to be used under conditions where there are severe limitations on the transport of gases into the catalyst particle ... 

FIGURE 5.16 Schematic of resistance model for diffusion, uptake, and reaction of gases with liquids. Tg represents the transport of gases to the surface of the particle, a the mass accommodation coefficient for transfer across the interface, rso, the solubilization and diffusion in the liquid phase, riM the bulk liquid-phase reaction, and rinlcrl.ll c the reaction of the gas at the interface. 

Every sorption set-up also allows for the extraction of information about sorption dynamics and gas transport provided that the resolution in time of the sensor applied is adjusted to the process under investigation. In an earlier publication we studied the transport of gases into the mesopores of monolithic materials by analyzing the pressure relaxation after the dosing of a defined amount of gas onto the sample [3]. An improvement of the resolution in time allows to investigate also small monoliths or samples with larger pores. 

Poly( inyl chloride), poly(acrylonitrile) and the high acrylonitrile copolymers have presented the major problems with respect to reducing the residual monomer content to extremely low levels. These are in the glas state tmder the conditions where monomer removal must be carried out. In principle, the temperature should be raised above the glass temperature to facilitate monomer removal. In practice, however, the systems are usually lattices or slurries of suspension polymer and coagulation could become a problem. In any case, both the rubbery and glassy states must be considered in any discussion of the monomer removal problem. The basic principles of the transport of gases in both situations have been presented briefly and with appropriate literature references in the introductory section of this review. 

Quantitative Model of Single-Gas Transport through Microporous Materials Usually the transport of gases is described by Pick s first law ... 

Datta, R., et al. Generalized model for the transport of gases in porous, non-porous, and leaky membranes. I. Application to single gases, J. Membr. Sci., 75, 245, 1992. 

The transport of gases in and through glassy polymers is best... 

Figure 8.9. Schematic representation of the transport of gases along a crack to its tip.

---