Heavy Normal Paraffin Separation

J. V. Bmnnock, Separation and distribution of normal paraffins from petroleum heavy distillates by molecular sieve adsorption and gas cliromatogr aphy , Anal. Chem. 38 1648-1652(1966). 

The sulfoxidation of normal Cl4-CI7 paraffins with sulfur dioxide, oxygen, and water is performed under UV radiation in parallel reactors (1 in Fig. 3). The reaction enthalpy is dissipated by cooling of the paraffin in heat exchangers. The 30- to 60-kW UV lamps are cooled by a temperature-controlled water cycle. The reaction mixture leaving the reactors separates spontaneously into two phases in 2. The lighter paraffin phase is recirculated to the reactors. The composition of the heavy raw acid phase is shown in Table 5. 

Kulprathipanja, S. (1991) Adsorptive separation process for the purification of heavy normal paraffins with non-normal hydrocarbon pre-pulse stream. U.S. Patent 4,992,618. 

In 2009 the estimated worldwide detergent range normal paraffin capacity was approximately 3.6 x lO t/year. With more than 27 Ucensed Molex units, liquid-phase adsorption separation is the predominant technology for heavy normal paraffin production. 

Description Straight-run kerosine is fed to a stripper (1) and a rerun column (2) to remove light and heavy materials. The remaining heart-cut kerosine is heated in a charge heater (3) and then treated in a Unionfining reactor (4) to remove impurities. The reactor effluent is sent to a product separator (5) to separate gas for recycle, and then the liquid is sent to a product stripper (6) to remove light ends. The bottoms stream from the product stripper is sent to a Molex unit (7) to recover normal paraffins. 

Source J. V. Brunnock, Separation and Distribution of Normal Paraffins from Petroleum Heavy Distillates by Molecular Sieve Adsorption and Gas Chromatography, Analytical Chemistry 38 1648-1652 (1966). With permission. 

SDA. The most common method used for asphaltene precipitation. It uses a solvent (light paraffin such as C3,C4,C5, and C7) to separate a residue into a deasphalted oil (DAO) and a pitch (asphaltene), containing the latter most of the impurities of the feedstock. DAO is normally used as FCC or hydroaacker feed. SDA is used in refineries to upgrade heavy bottoms streams to DAO that may be processed to produce transportation fuels. The process may also be used in the oil field to enhance the value of heavy crude oil before it gets to the refinery (Billon et al., 1997 McOrath, 2008). 

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