Rich oil

The rich oil from the absorber is expanded through a hydrauHc turbiae for power recovery. The fluid from the turbiae is flashed ia the rich-oil flash tank to 2.1 MPa (300 psi) and —32°C. The flash vapor is compressed until it equals the inlet pressure before it is recycled to the inlet. The oil phase from the flash passes through another heat exchanger and to the rich-oil deethanizer. The ethane-rich overhead gas produced from the deethanizer is compressed and used for produciag petrochemicals or is added to the residue-gas stream. 

The lean oil from the lean-oil fractionator passes through several heat exchangers and then through a refrigerator where the temperature is lowered to —37° C. Part of the lean oil is used as a reflux to the lower section of the rich-oil deethanizer. Most of the lean oil is presaturated ia the top section of the deethanizer, is cooled again to —37° C, and is returned to the top of the absorber, thus completing the oil cycle. 

In Estonia, most of the rich oil shale, 209 L/1 kukersite, is burned as a soHd fuel to produce electric power (37). The kukersite, although technically an oil shale, is actually similar to a high ash, low grade coal (qv) ideally suited for this use. 

Convergence was achieved rapidly in five iterations by using Eq. (13-88) as the criterion. Computed compositions for lean gas and rich oil are ... 

The oldest kind of gas plants are absorption/lean oil plants, where a kerosene type oil is circulated through the plant as shown in Figure 9-1. The lean oil is used to ab.sorb light hydrocarbon components from the gas. The light components are separated from the rich oil and the lean oil is recycled. 

Rich oil flows to the rich oil de-ethanizer (or de-methanizer) to reject the methane and ethane (or the methane alone) as flash gas. In most lean... 

The ROD is similar to a cold feed stabilizing tower for the rich oil. Heat is added at the bottom to drive off almost all the methane (and most likely ethane) from the bottoms product by exchanging heat with the hot lean oil coming from the still. A reflux is provided by a small stream of cold lean oil injected at the top of the ROD. Gas off the tower overhead is used as plant fuel and/or is compressed. The amount of intermediate components flashed with this gas can be controlled by adjusting the cold loan oil retlux rate. 

Example 8-20 Open Steam Stripping of Heavy Absorber Rich Oil of Li t Hydrocarbon Content (used by permission following the method of R. W. EUerbee, Chemical Engineering [127])... 

Figure 8-41. Open steam stripping light hydrocarbons from a rich oil. Modified for Example 8-20 and used by pemnission, Ellerbee, R. W., C/iem. Eng. Mar. 4 (1974), p. 108.

Many operations in petrochemical plants require the absorption of components from gas streams into lean oils or solvents. The resultant rich oil is then stripped or denuded of the absorbed materials. The greatest use of this operation utilizes hydrocarbon materials, but the basic principles are applicable to other systems provided adequate equilibrium data are available. 

Note that no recovery can be greater than 1.00, so any value so calculated is recorded as 1.00, indicating that the component is completely stripped from the rich oil. Calculate mols stripped per hour for each component as in Step 2. 

For final detail, recalculate mols stripped per hour from new Eg, values and the total quantities of each component in the incoming rich oil. If values do not check exactly, adjustments can be made in steam rate and SYj to give exact values. In many cases this accuracy is not justified since the method is subject to some deviation from theoretically correct values. 

The composition and quantity of rich oil, and percent recovery of a specified key component are known, also column pressure and temperature. 

Effective Absorption Factor for n-C4. The total rich oil out is estimated as... 

Component 90°F K 75 psia Feed Gas In (mols/hr) Lean Oil in (Mol. Fraction) Initial Estimate Of Net Amount Absorbed (mols/hr) Off-Gas Lean Oil In (mols/hr) Rich Oil Out (mols/hr)... 

The total intercooler duty is the difference between the total heat in of the rich gas and lean oil and the total heat out of the off gas and rich oil all at the terminal calculated or design conditions. The total duty is often divided between several coolers placed to re-cool the oil as it passes down the column. If intercoolers are not used, then the absorption cannot meet the design terminal outlet conditions and the quantity of material absorbed will be reduced. If the intercooling is too great so as to sub-cool, then greater absorption may be achieved, but this can be controlled by the intercooler operation. 

Mols/hour rich oil entering stripper Liquid leaving bottom absorber tray, mols/hr. Mols/hr lean oil entering absorber, or leaving snipper... 

Batch with Constant Reflux Ratio, 48 Batch with Variable Reflux Rate Rectification, 50 Example 8-14 Batch Distillation, Constant Reflux Following the Procedure of Block, 51 Example 8-15 Vapor Boil-up Rate for Fixed Trays, 53 Example 8-16 Binary Batch Differential Distillation, 54 Example 8-17 Multicomponent Batch Distillation, 55 Steam Distillation, 57 Example 8-18 Multicomponent Steam Flash, 59 Example 8-18 Continuous Steam Flash Separation Process — Separation of Non-Volatile Component from Organics, 61 Example 8-20 Open Steam Stripping of Heavy Absorber Rich Oil of Light Hydrocarbon Content, 62 Distillation with Heat Balance,... 

If the rich oil is being returned from the secondary absorber, consider different processing. 

Today n-paraffms are exclusively produced from the corresponding distillation cuts of paraffin-rich oils with the use of molecular sieves. Molecular sieves are synthetically manufactured aluminum silicates of the zeolite type, which after dehydration have hollow spaces of specific diameters with openings of specific diameters. The molecules are then able to penetrate the openings in the correct size and form and are held in the hollow spaces by electrostatic or van der Waals forces. The diameter of the zeolite type used for the production of paraffins is 5 A and is refined so that the n-paraffins (C5-C24) can penetrate the hollow spaces while the iso- and cyclic paraffins are unable to pass through [15]. 

Propagation Release of rich oil and gas, formation of vapor cloud, ignition of vapor cloud by recompressors, collapse of absorber tower across pipe rack... 

During 2004, the Board requested all Governments to provide information on the manufacture of and trade in safrole and safrole-rich oils. By 1 November 2004, 65 Governments had responded to that request. 

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