Separation of Byproduct Components

SEPARATION OF BYPRODUCT COMPONENTS 611 TABLE 6. Composition of Deodorizer Distiiiate from Various Oiis (192). 

Separation of desire< components from waste or byproduct matter... 

Some small amount of byproduct formation occurs. The principal byproduct is di-isopropyl ether. The reactor product is cooled, and a phase separation of the resulting vapor-liquid mixture produces a vapor containing predominantly propylene and propane and a liquid containing predominantly the other components. Unreacted propylene is recycled to the reactor, and a purge prevents the buildup of propane. The first distillation in Fig. 10.3a (column Cl) removes... 

The separation of a racemic mixture into its enantiomeric components is termed resolution The first resolution that of tartaric acid was carried out by Louis Pasteur m 1848 Tartaric acid IS a byproduct of wine making and is almost always found as its dextrorotatory 2R 3R stereoisomer shown here m a perspective drawing and m a Fischer projection... 

Gum turpentine is obtained from wounding living trees to get an exudate containing turpentine and rosin. Turpentine is separated from the rosin by continuous steam distillation and further fractionation. Wood turpentine comes from the extraction of stumps of pine trees using naphtha, and subsequent separation of rosin and turpentine by fractional distillation. Tail-oil turpentine is a byproduct of the Kraft sulphate paper manufacture. Terpenes are isolated from the sulphate terpentine and separated from the black digestion liquor. The composition of turpentine oils depends on its source, although a-pinene and p-pinene are the major components. 

We have seen several examples of a technique for separation of gas mixtures which, in contrast with most commercial processes, requires no physical transfer of solvent, handling of solids, or cycling of temperature or pressure. The energy requirements can also be far lower The thermodynamic minimum work of separation is, under isothermal conditions, the free energy difference between the process stream and byproduct, or permeate, stream. When this difference is due only to the partial pressure difference of component 1, it becomes ... 

Gas-separation manager includes both vapor recovery and gas-separation systems. Vapor recovery handles the recovery of valuable condensable components from a gas stream or the removal of undesired components since they are corrosive, toxic, polymerizable, have a bad odor, etc. Gas separation deals with the recovery of recycled gaseous reactants, as well as with the delivery of purified products and byproducts. Douglas [6] recommends the following heuristics for placing the vapor-recovery system ... 

The reactor/separator/recycle structure is decided by considering the physical properties of the species found in the reactor effluent (Table 9.1). The catalyst and the organic phase are immiscible. Therefore, they can be separated by liquid-liquid splitting. The separation of the organic components by distillation seems easy. In a direct sequence, the inert and any light byproduct will be removed in the first column. The second column will separate the reactants, which have adjacent volatilities. Therefore, there will be only one recycle for both reactants. The third column will separate the product from the heavies. The reactor/separation/ recycle structure of the flowsheet is presented in Figure 9.2. 

Byproducts of conventional oil extraction and refining have been investigated as raw materials for the concentration of bioactive components. Birtigh et al. (115) investigated SFE of carotenes and tocopherols from waste products of pahn oil production (i.e., the residue of mechanical processing and palm leaves). Ibanez et al. (116) studied the separation of tocopherols from olive byproducts using fractional... 

Always include any component that has a specified limit in any of the feeds. These components can be a source of byproducts or can act as catalyst or enzyme inhibitors. They must be tracked to ensure that they do not accumulate in the process or make it difficult to meet product specifications. In some cases, an additional separation may be needed to remove a feed contaminant. 

Of course, PO is a highly reactive molecule and the by-product chemistry, often involving the titanium-on-silica catalyst, including isomerization, dimerization, hydrolysis, and alcoholysis, has also been (re)investigated. Not surprisingly, PO yield loss (and MPC, via adduct formation) and the separation of PO from trace components with similar boiling points, such as lower aldehydes, are the main byproduct issues here. Due to space limitations, this chemistry will not be discussed further here. 

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