Preparation Of Linalool By Hydrogenation Of Dehydrolinalool

Among the bulk fragrances,linalool series fragrances account for a large proportion in the formula of daily chemical and edible flavors,and are the core raw materials of the world's major fragrance manufacturers.Its core technology has long been monopolized by BASF and other international enterprises.In addition,linalool is not only an important spice,but also an important intermediate in the synthesis of violet ketone,raspberry ketone,Vitamin E and Vitamin K,which is in great demand every year.At present,the quality of linalool in the market requires the main content?98%and the content of dihydrolinalool?1%.The fragrance of linalyl requires both floral,fruity and woody,with a soft,light and penetrating aroma.If the content of dihydrolinalool is too high,it tends to have a strong fruity flavor,covering up the fragrance of flowers.Therefore,dihydrolinalool is a key control index in hydrogenated liquid.At present,in the process of preparing linalool by hydrogenation of dehydrolinalool,the content of dihydrolinalool in hydrogenated liquid is about 3%.In this paper,the hydrogenation of dehydrolinalool to prepare linalool was studied,with the purpose of reducing the content of dihydrolinalool in the hydrogenated reaction liquid,so as to reduce the distillation separation cost and improve the flavor of linalool.In this study,various factors including catalyst type,catalyst dosage,solvent type,solvent ratio,reaction assistant and reaction conditions were screened for exploratory study,and their aroma was also improved.Dehydrogenation of linalool to prepare linalool is a typical catalytic hydrogenation process.Catalytic hydrogenation is one of the most dangerous chemical processes under national supervision.In history,heavy casualties caused by hydrogenation process are numerous.Therefore,it is necessary to evaluate the safety of hydrogenation process.On the one hand,the danger of hydrogenation comes from the reaction heat,on the other hand,it is closely related to the material properties.In this paper,the stability and runaway exothermic reaction of the reaction were studied and the risk was evaluatedThe results show that lindera catalyst,water as a solvent and sodium carbonate as a additiv at 75? and the reaction pressure is gradually reduced,which is beneficial to control the content of dihydrolinalool in hydrogenated liquid.For the separation of hydrogenated liquid,the separation of the recombination component first and the separation of the light component is beneficial to the promotion of product aroma.At the same time,the safety risk assessment shows that the risk of the hydrogenation process is level 1,and the overall risk of the hydrogenation process is controllable.Through the above experimental studies,we have a deeper understanding of preparing linalool by dehydrolinalool,and the screened experimental conditions can be applied to large-scale production,which is conducive to saving production costs and ensuring safe production.