Folded oils, processing

The term folded oils refers to concentrated oils. This typically involves a distillation process however, alcohol washing can also be used. Alcohol washing is based on the insolubility of d-limonene in 60% to 70% ethanol. These processes predominately remove terpene compounds, although aldehydes (octanal) are also reduced. Oils that are more than 20-fold concentrated are called terpeneless oils and are more stable. Distillation is predominately used by flavor houses. Flavor houses purchase cold-pressed oil, which is concentrated and fractionated. These fractionated portions are sold for flavorings or flavor precursors. 

In this process, different batches of the same essential oil may be mixed together. Oils become more concentrated in some components and other components may become relatively reduced. The term folded oil is also used for essential oils with a component removed in order to concentrate more desirable constituents. When terpenes are removed, the resultant oil is termed a... 

Perfume materials obtained by distillation are referred to as essential oils. Thus, for example, the oil obtained by steam distillation of lavender is known as the essential oil of lavender or lavender oil. Sometimes, the monoterpenoid hydrocarbons are removed from the oils by distillation or solvent extraction to give a finer odour in the product. The process is known as deterpenation and the product is referred to as a terpeneless oil or folded oil. 

Vacuum distillation, steam distillation, extraction with solvents, and adsorption processes are used for folding cold-pressed oils. How each affects the quality of the folded oil will be briefly described. 

Process plant design has come a long way from the early 1930s when process designers used the rule-of-thumb that a process faciUty could not be scaled-up more than 10-fold (2). American Oil s Ultracracking unit (Texas City, Texas) for example, was designed from data from a small pilot plant with a scale-up factor of 80,000 (3). 

Later, Saito et al. [58] studied anodes with a layered structure consisting of Li/ protective film/additive/protective film/Li/ protective film/additive/ -. They made the anode by dropping the additive on a lithium sheet, folding the lithium sheet, and then compressing the folded lithium with an oil press. They repeated this process more than ten times. The FOM in LiAsF6-EC/2MeTHF electrolyte was 7.41, 13.5, and 37.0 for a lithium anode without additives, a lithium anode with toluene in the electrolyte, and a layered-structure lithium anode containing toluene, respectively. 

Sasol is now a public company and its shares are listed on the Johannesburg Stock Exchange. Despite the fluctuations in the price of crude oil, the commercial success of the process is reflected by the four-fold increase in the share prices since 1979. The reason for the viability of the process in South Africa is the combination of three factors ... 

Because of their high molecular weight and complexity, the asphaltenes remain an unknown entity in the hydrodesulfurization process. There are indications that, with respect to some residua and heavy oils, removal of the asphaltenes prior to the hydrodesulfurization step brings out a several fold increase in the rate of hydrodesulfurization and that, with these particular residua (or heavy oils), the asphaltenes must actually inhibit hydrodesulfurization. As a result of the behavior of the asphaltenes, there have been several attempts to focus attention on the asphaltenes during hydrodesulfurization studies. The other fractions of a... 

In the process (Figure 8-20), the residuum is mixed with several-fold volume of a low-boiling hydrocarbon solvent and passed into the asphaltene separator vessel. Asphaltenes rejected by the solvent are separated from the bottom of the vessel and are further processed by heating and steam stripping to remove a small quantity of dissolved solvent. The solvent free asphaltenes are pumped to fuel oil blending or further processing. 

The E-factors of different types of chemical processes are shown in Table 13.4.32 In general, processes performed on a larger scale tend to involve fewer operations and form simpler products. Both facets help lead to lower E-factor values. Remarkably, oil refining generates approximately 10-fold more product than waste. In contrast, pharmaceutical processes can be less than 1% efficient based on waste production. The commercial process of sildenafil (13.73), highlighted in the Case Study below, has been optimized more extensively than the typical pharmaceutical synthesis. 

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