Study On Synthetic Perfume From Turpentine

Turpentine, an important renewable resource, plays an important role in thesynthesis of flavor and fragrances. It is well known that α-pinene and β-pinene can beconveniently separated by fractional distillation from turpentine. In this thesis, wemainly investigate the synthesis of various kinds of flavor and fragrances fromα-pinene and β-pinene as raw materials. This thesis is composed of two parts. Thefirst part is the method of preparation of ocimene from thermal isomerization ofα-pinene.And the second part is the synthesis of nerol and geraniol from myrcene.The first part is the method of preparation of ocimene from thermalisomerization of α-pinene. The key is to overcome the shortcomings of thermalisomerization reaction, such as poor selectivity, low yield, high costs, and so on. Inthis work, four kinds of pyrolysis apparatus are designed. The influence of thetemperature, pressure, time and other process conditions on thermal isomerization ofα-pinene in the gas phase and liquid phase is respectively discussed. Under gas phaseconditions, the conversion rate of α-pinene is80-90%and the selectivity of ocimene is28-33%. Under liquid phase conditions, the conversion rate of α-pinene is50-60%and the selectivity of ocimene is50-55%. Because a fast isomerization reaction ofocimene at a relatively high temperature is found in experiments, the yield of ocimenecan be decreased. Thus, the kinetics and mechanism of thermal isomerization ofocimene into allo-ocinene in the liquid phase are studied. The conclusion is that theocimene is safe when temperature is below100℃. The mechanism and kineticbehavior of thermal isomerization of α-pinene are discussed. The conclusion is thatthe gas phase reaction temperature is calculated to be400-450℃and the liquid phasereaction temperature is calculated to be450-500℃. The process of fractionaldistillation of ocimene is researched. The method of manufacturing ocimene isalready designed in industrial scale. The technology has achieved considerableeconomic benefits.The second part is the synthesis of nerol and geraniol from myrcene. The key is toovercome the shortcomings of the addition reaction, such as poor selectivity, lowyield, polluting environment, and so on. Myrcene can be obtained in good yield by thermal isomerization of β-pinene. Myrcene is treated with dry hydrogen chloride inthe presence of cuprous chloride, obtaining geranyl chloride, neryl chloride. Thechlorides are treated with sodium acetate to yield the corresponding acetates. Thehydrolysis of acetates leads to the desired alcohols. The influence of the catalyst,temperature, time and other process conditions on selectivity of addition reaction isrespectively discussed.