tanacetum parthenium l. known as feverfew is a medicinal herb which is found in many old gardens. it has been used in folk medicine for reducing fever. feverfew is a member of the daisy family; it is used primarily to prevent migraine headaches and to treat rheumatoid arthritis.it hasa colorless essential oil that contains one or more of the sesquiterpene lactones as active principle. tanasetum...

Sneesby et al. recently suggested that adding trays in the stripping and rectifying sections of a reacti®e distillation column can degrade performance. This effect, if true, is not only counterintuiti®e, but ®ery disturbing because it suggests that the design of reacti®e distillation columns cannot use conser®ati®e estimates of tray numbers, that is, we cannot simply add excess trays, as in con...

The U.S. Dept. of Energy estimates that there are more than 40,000 distillation columns in North America, and that they consume about 40% of the total energy used to operate plants in the refining and bulk chemical industries (1). Improving the energy efficiency of this unit operation, therefore, is important to achieving overall plant energy savings. Reducing the energy consumption of distilla...

Extractive distillation is an alternative for ethanol dehydration processes that has been shown to be more effective than azeotropic distillation and, in close proximity, to be very competitive against the process that uses adsorption with molecular sieves. Glycols have been shown to be the most effective solvents in extractive distillation, mainly ethylene glycol and glycerol. In this work, an...

Topic distillation is the process of finding representative pages relevant to a given query. Well-known topic distillation approaches such as the HITS algorithm have shown to be useful in identifying high quality pages of the most popular topic within a query specific graph of hyperlinked documents. Many succeeding researchers focus on augmenting HITS with further content analysis to alleviate ...

many parameters affect essential oil yield and chemical composition of aromatic plants. for obtaining the highest quantity and quality of essential oil, it is necessary to know the proper methods of drying and distillation. the aim of this research was to investigate the influence of drying and extraction methods on the yield and chemical composition of the essential oil of eucalyptus sargentii...

The composition of the essential oils of Teucrium chamaedrys L. belongs to the family Lamiaceae, It is growing wild in the margin of mountainous roads of arid and cold climate of north Iran. In this research, essential oils of Teucrium chamaedrys L., extracted and measured at the different location by different methods of distillationand then were analyzed by GC and GC/MS. Investigation and com...

Reactive distillation is an excellent example of recent advances in process intensification. It combines reaction and separation operations in one piece of equipment. This paper studies the steady-state economic optimum design of a chemical process with a generic exothermic reversible reaction A+B↔C+D for two different process flowsheets: a conventional multi-unit reactor/separator/recycle stru...

The development of a reactive distillation process for the production of n-butyl acetate by transesterification of methyl acetate with n-butanol is presented. Thermodynamic aspects of the quaternary system n-butyl acetate – n-butanol – methyl acetate – methanol are discussed and UNIQUAC interaction parameters derived using the Dortmund Data Bank (DDB) are given. The reaction kinetics of the het...