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ARS Home » Research » Publications at this Location » Publication #118999


item Cermak, Steven - Steve
item Isbell, Terry

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/2/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary: How do you separate two or more items from one another? How can you turn a dark, useless solution into something that is useful and lighter in color? The answer to these questions is by the help of distillation. Distillation, which uses heat and vacuum, was used to help remove unwanted substances from a U.S. crop called meadowfoam. One of the current problems with meadowfoam is purifying enough material to be used by companies. With the help of a pilot plant molecular still, which is just a very big distillation unit, our lab was able to develop new ways to purify this new crop. Purified meadowfoam compounds are currently used in shampoo and conditioners. These new products are very mild on the hair as well as on the environment because they biodegrade, which means they break down, dissolve and disappear once they enter rivers or landfills. By inventing new and better ways to get meadowfoam into the cosmetic industry, we can look good as well as feel good about the environment.

Technical Abstract: A molecular distillation unit is a powerful method of separation. The separation occurs at extremely low pressures and, therefore, at reduced temperatures. Consequently, with these parameters, the molecular distillation unit is very useful in the distillation of either molecules of high molecular weight or those which are sensitive to thermal conditions. Centrifugal and falling films are two basic types of molecular distillation which require a short exposure of the distilled liquid on the evaporating cylinder. Crude meadowfoam fatty acids, which are mainly long chain monoenes, ?-5 C20, were distilled using a Myers 15 pilot plant centrifugal molecular distillation unit to give a distillate that was light in color (Gardner Color = 1). The optimal distillation conditions were explored by varying the rotor temperature, degas temperature, rotor preheat, and flow rate onto the rotor. As the conditions were varied, the distillate was monitored for color, fatty acid composition, and mass split between distillate and residue. At very high rotor temperatures, the color of the distillate and the fatty acid composition deteriorated, but the same split was observed as with a low rotor temperature. All the conditions played a vital role in conducting a successful distillation and, in most cases, there were direct correlations between temperatures & amounts of different fatty acids. The optimum conditions were determined through the course of numerous trials. These conditions were then employed to distill the remaining 25 gallons of meadowfoam fatty acids, thus verifying that the parameters were correct.