Condenser separation system

Whether heat integration is restricted to the separation system or allowed with the rest of the process, integration always benefits from colder reboiler streams and hotter condenser streams. This point is dealt with in more general terms in Chap. 12. In addition, when column pressures are allowed to vary, columns with smaller temperature differences are easier to integrate, since smaller changes in pressure are required to achieve suitable integration. This second point is explained in more detail in Chap. 14. 

One common approximation is to separate the nuclear and electronic degrees of freedom. Since the nuclei are considerably more massive than the electrons, it can be assumed that the electrons will respond mstantaneously to the nuclear coordinates. This approximation is called the Bom-Oppenlieimer or adiabatic approximation. It allows one to treat the nuclear coordinates as classical parameters. For most condensed matter systems, this assumption is highly accurate [11, 12]. 

The first molecular dynamics simulation of a condensed phase system was performed by Alder and Wainwright in 1957 using a hard-sphere model [Alder and Wainwright 1957]. In this model, the spheres move at constant velocity in straight lines between collisions. All collisions are perfectly elastic and occur when the separation between the centres of... 

An alternative way of deriving the BET equation is to express the problem in statistical-mechanical rather than kinetic terms. Adsorption is explicitly assumed to be localized the surface is regarded as an array of identical adsorption sites, and each of these sites is assumed to form the base of a stack of sites extending out from the surface each stack is treated as a separate system, i.e. the occupancy of any site is independent of the occupancy of sites in neighbouring stacks—a condition which corresponds to the neglect of lateral interactions in the BET model. The further postulate that in any stack the site in the ith layer can be occupied only if all the underlying sites are already occupied, corresponds to the BET picture in which condensation of molecules to form the ith layer can only take place on to molecules which are present in the (i — l)th layer. 

Care should be exercised when sampling for aerosols that are condensable. Some separating systems, such as wet impingers, may remove the condensables from the gas stream, whereas others, such as electrostatic precipitators, will not. Of equal concern should be possible reactions in the sampling system to form precipitates or aerosols which are not normally found when the stack gases are exhausted directly to the atmosphere. SO-,... 

From a hydrate melting standpoint it is possible in the winter time to have too cold a liquid temperature and thus plug the liquid outlet of the low temperature separator. It is easier for field personnel to understand and operate a line heater for hydrate control and a multistage flash or condensate stabilizer system to maximize liquids recovery. 

Figure 6-3 shows a condensate stabilizer system. The well stream flows to a high pressure, three-phase separator. Liquids containing a high fraction of light ends are cooled and enter the stabilizer tower at approxi-... 

Entrainment Separators. In any process in which the product is volatilized, including both Gas Recycle and Liquid Recycle, ppm or ppb levels of metal catalyst may be entrained in the vapors leaving the separation system. Entrainment separators (Figure 2.9) are often included to recover the metal. Vaporous product effluent from a gas recycle reactor may be sent to a separator where it is passed through a demisting pad to return some aldehyde and condensation product and particularly to prevent potential carryover of catalyst. [6]... 

A soil is a condensed colloid system because the negatively charged, plateshaped crystals are assembled in parallel or near-parallel alignment, to form stable operational entities, described as clay domains. The crystals within a day domain can be represented by a three-plate crystal model in which one crystal separates the other two crystals to produce a slit-shaped pore, where the crystals overlap. This situation is illustrated in Figure 3.4. 

The onshore complex comprises a slugcatcher and separator system, condensate stabilisation and storoge, domestic gos plont and future LNG plant. 

Effluent woter from the Primory Woter/Condensate Separator is essentially hydrocorbon free and is discharged into the Drain Sump Coisson, which also collects the other effluent streams from the platform droinage systems. Any hydrocarbon accumulated in the droin caisson is recovered in the Skimmer Vessel, stored and finolly injected into the pipeline. 

Gas specifications will be inqportant only if the gas is to be delivered to a gas pipeline system. If the gas is to be injected in the producing field the only usual critical requirement is to dehydrate the gas adequately to prevent hydrate formation anywhere in the system. The gas pipeline specification which most Influences the design of oil-gas separation systems is the hydrocarbon dewpoint limitation. This is usually expressed as a maximum dewpoint temperature at a specified pressure. For onshore gas pipelines in the USA end Europe this specification may be in the range of 32°F (0°C) at 1000 paia (68 atmospheres), which is adequate to prevent condensation of liquids in the pipelines in the normal range of onshore pipeline operating pressures from 900 to 1000 psl. In the USA this specification is seldom iiqposcd on producers and is controlled with pipeline facilities. 

Wet gases are usually separated in two-stage separation systems such as Figure 13-1. At the surface, the well stream is separated into stock-tank liquid (condensate), separator gas, and stock-tank gas. All three of these fluids must be included in the recombination calculation. 

Since helium and neon have boiling points considerably below that of nitrogen, these gases will collect on the nitrogen side of the condenser-reboiler associated with the double-column air separation system. Recovery of these gases is accomplished by periodic venting of a small portion of the gas from the dome of the condenser and transfer to a small condenser-rectifier refrigerated with... 

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