Hydrocarbons liquid

Adsorption may occur from the vapor phase rather than from the solution phase. Thus Fig. Ill-16 shows the surface tension lowering when water was exposed for various hydrocarbon vapors is the saturation pressure, that is, the vapor pressure of the pure liquid hydrocarbon. The activity of the hydrocarbon is given by its vapor pressure, and the Gibbs equation takes the form... 

This preparation illustrates the preparation of a liquid hydrocarbon from a Grignard reagent. The Grignard reagent from n-hexyl bromide may be decomposed either with dilute sulphuric acid or with solid ammonium chloride the latter gives a somewhat better 3neld. 

Separations based upon differences in the chemical properties of the components. Thus a mixture of toluene and anihne may be separated by extraction with dilute hydrochloric acid the aniline passes into the aqueous layer in the form of the salt, anihne hydrochloride, and may be recovered by neutralisation. Similarly, a mixture of phenol and toluene may be separated by treatment with dilute sodium hydroxide. The above examples are, of comse, simple apphcations of the fact that the various components fah into different solubihty groups (compare Section XI,5). Another example is the separation of a mixture of di-n-butyl ether and chlorobenzene concentrated sulphuric acid dissolves only the w-butyl other and it may be recovered from solution by dilution with water. With some classes of compounds, e.g., unsaturated compounds, concentrated sulphuric acid leads to polymerisation, sulphona-tion, etc., so that the original component cannot be recovered unchanged this solvent, therefore, possesses hmited apphcation. Phenols may be separated from acids (for example, o-cresol from benzoic acid) by a dilute solution of sodium bicarbonate the weakly acidic phenols (and also enols) are not converted into salts by this reagent and may be removed by ether extraction or by other means the acids pass into solution as the sodium salts and may be recovered after acidification. Aldehydes, e.g., benzaldehyde, may be separated from liquid hydrocarbons and other neutral, water-insoluble hquid compounds by shaking with a solution of sodium bisulphite the aldehyde forms a sohd bisulphite compound, which may be filtered off and decomposed with dilute acid or with sodium bicarbonate solution in order to recover the aldehyde. 

We shonld also utilize liquid hydrocarbons, which frequently accompany natural gas. These so-called natural gas liquids currently have little use besides their caloric heat value. They consist mainly of saturated straight hydrocarbons chains containing 3-6 carbon atoms, as well as some aromatics. As we found (Chapter 8), it is possible by superacidic catalytic treatment to upgrade these liquids to high-octane, commercially usable gasoline. Their use will not per se solve our long-... 

A similarly accurate but slightly more complex method for prediction of densities of defined hqiiid hydrocarbon mixtures at their bubble points was published by Hanldnson and Thomson and was previously cited for prediction of pure liquid hydrocarbons. 

TABLE 27-13 Basic Approaches of Coal Conversion to Liquid Hydrocarbons... 

Fischer-Tropsch Synthesis The best-known technology for producing hydrocarbons from synthesis gas is the Fischer-Tropsch synthesis. This technology was first demonstrated in Germany in 1902 by Sabatier and Senderens when they hydrogenated carbon monoxide (CO) to methane, using a nickel catalyst. In 1926 Fischer and Tropsch were awarded a patent for the discovery of a catalytic technique to convert synthesis gas to liquid hydrocarbons similar to petroleum. 

Zanker, Adam, Estimating Surface Tension Changes For Liquids, Hydrocarbon Processing, April 1980, p. 207. 

An easy to use nomograph has been developed for the solubility of liquid hydrocarbons in water at ambient conditions (25°C). The accuracy of the nomograph has been checked against available solubility data. Performance of the nomograph has been compared with the predictions given by two available analytical correlations. The nomograph is much simpler to use and far more accurate than either of the analytical methods. 

Regression Constants and Nomograph Coordinates for the Soiubilities of Liquid Hydrocarbons in Water at 25°C... 

Water or water plus methanol has negligible effeet on predicted liquid-hydrocarbon knockout. 

Methanol eoncentration has essentially no effect on predicted water content of the liquid-hydrocarbon phase. The water eontent (not shown in the tables) was about 0.02 mol%. 

Liquid Hydrocarbon Fuei Mass Transfer Number B... 

In this process ethylene, dissolved in a liquid hydrocarbon such as cyclohexane, is polymerised by a supported metal oxide catalyst at about 130-160°C and at about 200-500 Ibf/in (1.4-3.5 MPa) pressure. The solvent serves to dissolve polymer as it is formed and as a heat transfer medium but is otherwise inert. 

The VPS overhead consists of steam, inerts, condensable and non-condensable hydrocarbons. The condensables result from low boiling material present in the reduced crude feed and from entrainment of liquid from the VPS top tray. The noncondensables result from cracking at the high temperatures employed in the VPS. Inerts result from leakage of air into the evacuated system. Steam and condensable hydrocarbons are condensed using an overhead water-cooled condenser. The distillate drum serves to separate inerts and non-condensables from condensate, as well as liquid hydrocarbons from water. Vacuum is maintained in the VPS using steam jet ejectors. 

Contingencies by which liquid hydrocarbon could be discharged through the atmospheric vent must be positively eliminated. 

Disposal of Drainage of Process Equipment Contents - When items of onsite process equipment are taken out of service, either individually during plant operation or for general turnaround, means of draining and safe disposal of the residual liquid hydrocarbon contents must be provided. The following are important considerations and terminology in the design ... 

The term inventory refers to liquid hydrocarbon contents at the top of the working level range. Tray holdup is included, but piping contents are disregarded. 

Table 1 provides a summary of the safe practices applied to the disposal of liquid hydrocarbon contents from various sources. 

The purpose of a blowdown drum is to disengage closed safety valve releases and various drainage, blowdown and diverted materials into liquid and vapor streams which can be safely disposed of to appropriate storage and flaring facilities, respectively. Entrainment of liquid hydrocarbons into a flare stack is not acceptable, since the potential exists for burning liquid falling onto the ground or adjacent facilities. For this reason, a blowdown drum is required. 

The first vessel in the blowdown system is therefore an acid-hydrocarbon separator. This drum is provided with a pump to transfer disengaged acid to the spent acid tank. Disengaged liquid hydrocarbon is preferably pumped back to the process, or to slop storage or a regular non-condensible lowdown drum. The vented vapor stream from the acid-hydrocarbon separator is bubbled through a layer of caustic soda solution in a neutralizing drum and is then routed to the flare header. To avoid corrosion in the special acid blowdown system, no releases which may contain water or alkaline solutions are routed into it. 

Four skimming connections with trycocks are normally provided at the outlet end of the drum, at the normal liquid level, and at 150 mm, 450 mm, and 500 mm below the normal level. Liquid hydrocarbon skimmed from these connections can be pumped to a suitable slop system. A coimection to the suction of a blowdown drum pumpout pump, if available, is adequate for this purpose. 

In some cases, it is possible to combine the functions of blowdown and disengaging drums in one vessel. However, PR devices discharging liquid hydrocarbons lighter than pentane should not be connected into the drum if there is a possibility that such liquids could accumulate and be released to the sewer through the seal leg. Also, the drum vent should be sized to prevent pressure buildup due to vaporization. In these applications, the design criteria for both services must be met and special attention should be paid to potential hazards and problems which may be introduced, such as ... 

Liquid hydrocarbons accumulated in non-condensible blowdown drums, originating from safety valves, closed drain headers, knockout drum drainage, etc. Facilities are normally provided at the drum for weathering volatile liquids and cooling hot liquids before disposal. 

---