泵注入方式进料催化菊芋根茎溶液制备多元醇

以硝酸镍和偏钨酸铵为前驱体,活性炭(AC)为载体,通过等体积浸渍氢气还原法分别制备Ni-W2C/AC和Ni/AC催化剂,利用N2吸附仪、XRD、TEM、TG和XRF等对催化剂及原料进行表征。釜式反应器中,对催化剂催化果糖或果糖基能源植物菊芋根茎制备多元醇高附加值化合物进行评价。结果表明,相同反应温度下,与间歇进料方式相比,泵注入方式能进一步提高1,2-丙二醇和乙二醇收率。以果糖为底物,泵速0.5 m L·min-1条件下,氢气起始压力4.0 MPa、温度245℃时,1,2-丙二醇和乙二醇收率分别为41.4%和18.7%,二者总收率较间歇进料增加17.9个百分点;以菊芋根茎为底物,氢气起始压力3.5 MPa、温度255℃时,1,2-丙二醇和乙二醇收率分别为37.7%和27.4%,二者总收率较间歇进料增加10.7个百分点。结合果糖、葡萄糖分子在氢气气氛下进行的逆羟醛缩合和加氢过程,分析泵注入进料提高1,2-丙二醇和乙二醇收率的主要原因。

Synthesis of polyols by catalyzed hydrogenation of jerusalem artichoke rhizome solution with pump injection way

Using nickel nitrate and ammonium metatungstate as the precursors and active carbon(AC) as the support,Ni-W₂C/AC and Ni/AC catalysts were prepared respectively by incipient-wetness impregnation and hydrogen reduction method.The raw material of JAT and catalysts were characterized by N₂-physisorption,XRD,TEM,TG and XRF.A series of tests of catalytic hydrogenation of fructose or fructose-based energy plant Jerusalem artichoke rhizomes(JAR) to some high value-added polyols were implemented to evaluate the difference between the pump injection and intermittent feeding ways in the tank reactor.The results showed that pump injection feeding way could effectively improve the yields of 1,2-propanediol(1,2-PD) and ethanediol(ED),compared with the intermittent feeding mode at the same reaction temperature.The yields of 1,2-PD and ED were 41.4% and 18.7% from fructose under the condition of initial H₂ pressure 4.0 MPa,temperature 245 ℃,feed rate 0.5 mL·min^-1,and 4%Ni-20%W₂C/AC catalyst,and the total yield increased by 17.9 percentage point.The yields of 1,2-PD and ED were 37.7% and 27.4%,respectively,under the condition as follows:initial H₂ pressure 3.5 MPa and temperature 255 ℃ and JAR as the substrate,and the total yield of two polyols increased by 10.7 percentage point,compared with that of intermittent feeding way.The reasons for improving the yields of 1,2-PD and ED by pump injection feeding mode were also analyzed in combination with the retro-aldol and hydrogenation processes of fructose and glucose under the hydrogen atmosphere.