Study On The Hydrogenation Of Methyl 3-Hydroxypropionate To 1,3-Propanediol

1,3-propanediol (1,3-PDO) was widely used in chemical industry as an important material. It has attracted attention as an important monomer to synthesize a new type of polyester, polytrimethylene terephthalate. At present, chemical method was the main industrial route to synthesize 1,3-propanediol. Owing to lower selectivity and productivity by traditional chemical synthesis method under higher temperature, higher pressure, which had hindered the utilization of 1,3-PDO in polymer industries, so much attention has recently been paid to new synthesis routes. In the thesis, hydrogenation of methyl 3-hydroxypropionate (MHP) as material to 1,3-propanediol was studied.As methyl 3-hydroxypropionate B-hydroxyl was abnormal lively, when methyl 3-hydroxypropionate was hydrogenated, the general catalysts would easily induce the dehydration reaction, the products of hydrogenation were not only 1,3-PDO, but also mainly propanol, propionate, and other by-products. Therefore, preparation of a very neutral catalyst was the key to the reaction. In the paper, on the basis of the vast literature investigation and experiment, by comparing three existing hydrogenation catalysts for carbonyl group, the viewpoint was that the catalyst in which colloidal silica was used as a carrier, copper as component, by addition of Mn, P, Zn, La, Mg, Co, Ba and other promoter elements, prepared by co-precipitation, had high activity and selectivity.In the thesis, nano Cu-M-0/Si02 catalysts were prepared by co-precipitation method and the performance of catalytic hydrogenation for methyl 3-hydroxy-propionate to 1,3-propanediol on the nano catalysts were studied under a high-pressure micro continuum fixed-bed reactor. The effects of structure, texture and composition of the catalysts on the catalytic performance were investigated by characterizing the catalysts with XRD, TG-DTG, SEM, TEM, XPS and N2 adsorption/desorption analysis technique. The results showed that addition of promoters enhanced the activity and selectivity of Cu-M-O/SiO2 catalysts which promoted the dispersion of the active components effectively and stabilized the active center of the catalysts. Especially the copper-based catalyst of loaded P could restrain side-reaction effectively and improve selectivity obviously. Under the reaction conditions of 160°C, 6.8 MPa, hydrogen flux 95 mL/min and the volume ratio of MHP to MeOH 1:7, the conversion of MHP and the selectivity of 1,3-PDO could be 91.30 % and reach 90.15% respectively.