Miscellas

Screw-pressed oil is aUowed to stand to settle out suspended soUds, filtered through plate filter presses, and then pumped to storage. The oil-rich solvent (miscella) from the solvent-extraction process is filtered or clarified, and most of the solvent is removed in a long tube evaporator. FinaUy, the concentrated oil passes through a stripping column where sparging steam is injected to remove the residual solvent. A metric ton of cottonseed yields ca 91... 

Miscella- neous Incorporate IPE insight into the nrL i.itor training program (b,p)... 

Radiation Exposure From Consumer Products and Miscella-... 

The demand for nitrogen in a chemically fixed form (as opposed to elemental nitrogen gas) drives a huge international industry that encompasses the production of many nitrogen products. Nitrogen products had a total annual commercial value on the order of 50 billion in 1996. The cornerstone of this industry is ammonia. Virtually all ammonia is produced in anhydrous form via the Haber process. Anhydrous ammonia is the basic raw material in the manufacture of fertilizers, livestock feeds, commercial and military explosives, polymer intermediates, and miscella- neous chemicals.35... 

Hardly any batch-type oilseed solvent extractors remain. Three of the more popular types currently manufactured include (1) shallow bed-type extractors, where a 0.5-1.5 m thick layer of collets or flakes is pulled across a linear screen and extracted by drenching with a countercurrent flowing miscella consisting of solvent and solubilized oil (Fig. 34.13) (2) diffusion belt type, where deeper beds of collets or flakes are conveyed on a woven mesh or folding-pan belt while drenched in countercur-... 

In processing most oilseeds, hexane is stripped from the miscella by distillation to produce a crude oil that subsequently is alkali or physically refined. However, gossy-pol and other pigments become extremely difficult to bleach if left in warm cottonseed oil for more than a few days. It is normal practice for cottonseed oil mills to send their crude oil immediately to an alkali refinery or to operate an on-site miscella refinery, where phosphatides, FFA, and color pigments are removed by alkali treatment of the oil-extraction solvent mixture. Cooling the crude oil as produced, until refining, also slows fixing of color. 

In the process, miscella leaves the extractor at about 30-35 percent oil and is concentrated to approximately 65 percent oil by evaporation. The FFA in the concentrate then is reacted with alkali (sodium hydroxide solution) to produce soaps that are removed with other water-soluble compounds by centrifugation. Next, the solvent is removed from the miscella-refined oil by further evaporation, and the soapstock is spread on the meal in the DT to recover its solvent. Hexane vapors from the miscella and the DT are condensed, and the solvent is recycled to the extractor for reuse. The noncondensable gases are passed through a mineral oil stripper to recover the last traces of hexane. 

The liquid enters the steam stripper at the same temperature it had leaving the Miscella still. 

Overall heat-transfer coefficient in cookers and in Miscella stills = 100 Btu/(hXft2X°F) (applies for walls or tubes). 

The liquid leaving the Miscella still may be assumed to contain 8 percent solvent by weight. 

No agitators are necessary in the cookers or Miscella tanks, because the boiling supplies sufficient agitation. 

It will be necessary to purchase the cookers, the Miscella stills, the condensers and the heaters for these pieces of equipment, and all pumps. 

Tanks. Suitable for cookers or Miscella stills (diameter less than 9 ft) ... 

The Production of Soy Lecithin. The soy beans are cleaned, de-hulled and cracked, followed by rolling to obtain thin flakes. These flakes are then treated with solvent, where the resulting mixture is known as a miscella. After filtration the solvent is removed by vacuum distillation, leaving the residue, a reddish yellow oil, which contains some 2% impure lecithin. The oil and lecithin mix is heated to 70-90 °C and... 

In the extractor, the solids, which are at about 80°C, are solvent-washed in stages, first with hexane already high in oil content (miscella) and then with progressively... 

Copra undergoes an accelerated preliminary extraction with a controlled residual oil content of 14-18% in the expeller meal expeller throughput rate is almost doubled. Hexane (bp 68.7°C) is widely used as the solvent for extraction. In an extraction unit that operates on a countercurrent system, the cake is met by oil-rich miscella (hexane + oil) and leaves the extractor as it is rinsed with pure hexane. The solvent-extracted cake has a residual oil content of approximately 3.5%. 

Hexane in miscella and cake is recovered for reuse in succeeding operations. Escaping hexane vapors are trapped by cold mineral oil spray to preclude hazards and maximize solvent recovery. 

Miscella (oil-solvent mixture) MARC (solvent ladden collets or flakes) 1... 

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