Study On Synthesis Of 1,3-dihydroxyacetone From Glycerol

In recent years, with the rise of production and utilization of biodiesel and other renewable energy, using glycerine, the by-product of biodiesel as raw material preparation into high value-added fine chemicals become a hot research topic in the field of biological and chemical. Among them, the conversion of glycerol to prepare1,3-dihydroxyacetone( DHA) is an important way of transformation.1,3-dihydroxyacetone is an important fine chemicals, it is widely used and has a high value of application. In this paper, a series of research work was carried out on the preparation of 1,3-dihydroxyacetone by glycerol, and a series of studies were carried out on the preparation of the intermediate product separation, catalytic oxidation and magnetic nano supported catalyst. It is divided into three aspects:(1) glycerol and benzaldehyde acetal reaction, get two kinds of products:cis- and trans-2-phenyl-1,3-dioxane-5-alcohol(HPD) and cis-and trans-4-hydroxymethyl-2-phenyl-1,3-dioxolane(HMPD), using acid catalyzed balance exists between the products and the differences in solubility in the mixed solution of benzene and petroleum ether, the directional transformation and crystallization separation were studied, we get cis-2-phenyl-1,3-dioxane-5-alcohol(cis-HPD),the maximum yield is96.6%, the purity is 96.5%.(2) Useing H2O2 and tert-Butyl nitrite(TBN)/2,2,6,6-Tetramethylpiperidinooxy(TEMPO)/O2,two kinds of clean, efficient and safe catalytic oxidation system to oxidize the cis-2-phenyl-1,3-dioxane-5-alcohol to corresponding carbonyl compounds2-phenyl-1,3-dioxane-5-ketone(PDO), the effects of different reaction conditions on the oxidation reaction was studied by single factor experiment of better system of TBN/TEMPO/O2, determine the optimum reaction conditions, the maximum yield of PDO was 95%. Through the acid hydrolysis of PDO, the 1,3-dihydroxyacetone(yield98%) was obtained.(3) in order to solve the problem of high price、hard to recycling of the TEMPO which in the TBN/TEMPO/O2 oxidation system, we designed and prepared theparticle size distribution of 10~50nm magnetic nanoparticles Fe3O4@SiO2-TEMPO catalyst,the load of TEMPO is 0.28mmol/g and saturation magnetization is26.6emu/g, its application in cis-2-phenyl-1,3-dioxane-5-alcohol and get the maximum yield of product of PDO was 91%. After 10 cycles, the magnetic properties and the activity of the magnetic response are not obviously decreased.