Gas-displacement processes

The mobility ratio between injected gas and the displaced oil bank in CO2 and other miscible gas-displacement processes is typically very unfavorable because of the relatively low viscosity of the injected phase. For example, the viscosity of CO2 at 110°F is about 0.03 cp at 1,500 psia and 0.06 cp at 2,500 psia. Viscosity ratios, Ao Ac02> floods conducted in west Texas have been reported to be between 8 and 50. As discussed in Chaps. 3 and 4, an unfavorable mobility ratio results in viscous fingering and reduced volumetric sweep efficiency. 

The oil-fiimace process, based on the partial combustion of Hquid aromatic residual hydrocarbons, was first introduced in the United States at the end of World War II. It rapidly displaced the then dominant channel (impingement) and gas-furnace processes because it gave improved yields and better product quahties. It was also independent of the geographical source of raw materials, a limitation on the channel process and other processes dependent on natural gas, making possible the worldwide location of manufacturing closer to the tire customers. Environmentally it favored elimination of particulate air pollution and was more versatile than all other competing processes. 

Fe(III) displacement of Al(III), Ga(III), or In(III) from their respective complexes with these tripodal ligands, have been determined. The M(III)-by-Fe(III) displacement processes are controlled by the ease of dissociation of Al(III), Ga(III), or In(III) Fe(III) may in turn be displaced from these complexes by edta (removal from the two non-equivalent sites gives rise to an appropriate kinetic pattern) (343). Kinetics and mechanism of a catalytic chloride ion effect on the dissociation of model siderophore-hydroxamate iron(III) complexes chloride and, to lesser extents, bromide and nitrate, catalyze ligand dissociation through transient coordination of the added anion to the iron (344). A catechol derivative of desferrioxamine has been found to remove iron from transferrin about 100 times faster than desferrioxamine itself it forms a significantly more stable product with Fe3+ (345). 

Research and development technologists at the Dow Chemical Company can characterize materials in a variety of ways. One material property that is especially critical in polymer foaming and processing technology is density. A tool used for measuring the density of a material is called a pycnometer. There are many different manual and automatic types to choose from. For extremely accurate and precise density measurements, an easy-to-use, fully automatic gas displacement pycnometer is utilized. Analyses are commenced with a single keystroke. Once an analysis is initiated, data are collected, calculations performed, and results displayed without further operator intervention. 

Miscible fluid displacement (miscible displacement) is an oil displacement process in which an alcohol, a refined hydrocarbon, a condensed petroleum gas, carbon dioxide, liquefied natural gas, or even exhaust gas is injected into an oil reservoir, at pressure levels such that the injected gas or fluid and reservoir oil are miscible the process may include the concurrent, alternating, or subsequent injection of water. 

The early findings in the field of nucleophilic displacement reactions in aromatic systems have been reviewed226. Two examples of these gas-phase processes, which are thought to proceed according to the addition/elimination sequence (S Ar) well established in solution chemistry, are reported in equations 30274 and 31. 

Multicomponent phase ecjuilibria involving three or more coexisting fluid phases is frequently encountered in liquefied natural gas processes (1), tertiary oil recovery by miscible gas displacement (2), and the use of surfactants in enhanced oil recovery (3). 

When comparing the gas-drive processes GDS and GDW the presence of surfactant in the displaced liquid has a great effect on the displacement mechanisms and flow patterns. Figure 9 shows schematically the final extent of sweep for gas-drive of brine without surfactant (Frame a) and with surfactant (Frame b). In each case the gas appears to have preferentially flowed through a few large channels that zig-zag across the raicromodel however, in... 

Natural gas displaced most manufactured gas for municipal distribution in industrialized countries after World War II. In the 1960s and 1970s, interest in developing advanced coal gasification processes was rekindled when it was believed that natural gas reserves would become insufficient in a few years to meet demand. This activity has since declined, but several coal gasification processes developed during this period have been commercialized and are used for production of fuel and synthesis gas. 

The present study describes the reactions of neutral alcohols with protonated carboxylic, carbonate, and organophosphorus acids or derivatives generated as gaseous ions under ion cyclotron resonance conditions. Evidence is presented on the mechanisms of these gas-phase ion-molecule reactions, which formally resemble acid-catalyzed acylation and phosphorylation commonly observed in solution. Gas-phase acylation appears to be a displacement process involving acylium ion transfer. Phosphorylation was not observed as such, but ions corresponding to dimethyl metaphosphate reacted rapidly with methanol in an exchange process. 

The two major pathways for phosphorylation reactions in condensed phase are strikingly similar to those for the corresponding acylation reactions (19). One pathway is an addition-elimination process whereby a nucleophile adds to the phosphoryl group to give a pentacoordinate intermediate that collapses to product by elimination of a nucleophile (mechanism A, Scheme VI). The other pathway is a displacement process in which the phosphoryl group is transferred as tricoordinate metaphosphate to the attacking nucleophile (mechanism B, Scheme VI). Numerous studies have documented the intervention of metaphosphate in phosphorylation reactions in condensed phase, although metaphosphate has eluded direct detection (19-24). The purpose of the ICR study reported here was to see if gas-phase phosphorylation can be achieved and whether metaphosphate intermediates are involved. 

Chapter 11 deals with the application of these concq>ts to process calculations in large-scale vacuum and pressure filters used in continuous and batch processes, hi all the examples presented, the importance of the consideration of the fiill filter cycle is stressed. Along with the development of modem fitters capable of operating in thin-cake conditions, units are also included for the dewatering of cakes by gas displacement and squeezing. 

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