生物质基粗甘油反应蒸馏制备羟基丙酮

以亚铬酸铜为催化剂,采用反应蒸馏工艺,通过实验考察了反应温度、甘油浓度、催化剂用量、反应物进料流量等因素对粗甘油脱水制羟基丙酮反应的影响.研究结果表明,在半连续操作条件下,反应温度对甘油转化率、羟基丙酮选择性和羟基丙酮收率有较大的影响;亚铬酸铜作为粗甘油脱水制羟基丙酮反应的催化剂容易失活.在该实验的装置中,适宜的反应条件为:反应温度范围为220～240%,甘油浓度为16.37～17.75mol/L,催化剂用量为45g/L,反应物进料流量为8ml/min.     

离子液体的固载化及其在甘油醚化中的性能

将实验室自制的离子液体[BMIM]BF_4固载在活性炭上作为催化剂,研究其在甘油与叔丁醇醚化反应中的催化性能,并利用单因素实验考察反应温度、反应时间、n(叔丁醇)∶n(甘油)和催化剂离子液体负载量对甘油转化率以及醚化产物选择性的影响。结果表明,在无需额外添加溶剂、n(叔丁醇)∶n(甘油)=4∶1和离子液体负载量为甘油质量的9%条件下,在85℃,以150 r·min~(-1)速率反应10 h,甘油羟基转化率最高可达73%,甘油二醚和甘油三醚选择性分别为32.67%和16.81%。     

软土地基上建筑物的相邻影响

一、在软土地基上相邻影响距离的计算公式: 由于相邻影响造成建筑物沉陷的现象是普遍存在的。目前国内外均用“角点法”来计算相邻影响的沉降量。我们根据几十个相邻影响的实例,得出下列关系公式,可初步估算相邻建筑物互相影响的距离。     

成核剂二-(3,4-二甲基苄叉)山梨醇在聚丙烯中的成核效应

研究成核剂二-(3,4-二甲基苄叉)山梨醇(DMDBS)对等规聚丙烯力学性能、光学性能和结晶行为的影响.结果表明:DMDBS可以大幅度提高聚丙烯的力学性能、光学性能和结晶峰温度,具有很好的成核性能.当成核剂DMDBS添加浓度为0.2%时,与空白聚丙烯相比,成核聚丙烯的拉伸强度和弯曲模量可分别提高7.46%和11.96%,雾度可降低52.32%,结晶峰温度T_c可从119℃左右提高到130℃左右.同时,DMDBS的加入可大幅度降低聚丙烯的球晶尺寸.     

阳离子交换树脂作催化剂合成乙酸乙酯的研究

以DOWEX MARATHONC型强酸性阳离子树脂为催化剂,在常压液相下用乙酸和乙醇合成乙酸乙酯。考察了反应温度、反应时间、催化剂用量和反应物初始摩尔比等参数对反应体系的乙酸乙酯收率影响。通过正交实验得到优化反应条件:反应时间为55 min,反应温度为70℃,催化剂用量为110 g/L,醇与酸摩尔比为1.5∶1,乙酸乙酯收率可达62%。     

生物质甘油醚类调和燃料的QSPR研究

基于距离矩阵建立单拓扑指数X,根据Grumberg-Nissan等公式建立并运用新的混合拓扑指数G对甘油醚类调和燃料的相关理化性质(密度、运动粘度、低热值)进行回归分析,建立定量结构-性质关系(QSPR)模型。所建QSPR模型皆具有良好的稳定性与预测能力,能较好地反映甘油醚类调和燃料的相关理化性质的变化规律。     

新型拓扑电负性指数模拟烃类物质闪点的标度

在距离矩阵的基础上采用原子的平衡电负性和相对键长校正含有多重键的化合物提出了两个新颖的拓扑电负性指数Y_C、W_C,结合路径数P3对92个碳氢化合物的局部化学微环境进行结构表征,并对化合物的闪点进行了QSPR研究。采用线性回归得到模型的复相关系数R和标准偏差S分别为0.9924和5.1799,模型实验值与计算值的平均绝对误差仅3.86K,相对误差1.46%。同时采用内部及外部双重验证的办法对所建模型进行检验,留一法（LOO）检验和训练集、检验集闪点的预测值和实验值较为吻合,结果表明模型具有良好的内部稳定性和外部预测能力。     

Estimation of surface tension of organic compounds using quantitative structure-property relationship

A novel quantitative structure-property relationship (QSPR) model for estimating the solution surface tension of 92 organic compounds at 20 °C was developed based on newly introduced atom-type topological indices. The data set contained non-polar and polar liquids, and saturated and unsaturated compounds. The regression analysis shows that excellent result is obtained with multiple linear regression. The predictive power of the proposed model was discussed using the leave-one-out (LOO) cross-validated (CV) method. The correlation coefficient (R) and the leave-one-out cross-validation correlation coefficient (R _CV) of multiple linear regression model are 0.991 4 and 0.991 3, respectively. The new model gives the average absolute relative deviation of 1.81% for 92 substances. The result demonstrates that novel topological indices based on the equilibrium electro-negativity of atom and the relative bond length are useful model parameters for QSPR analysis of compounds.     

柴油-生物柴油-乙醇溶解性及其调和燃料特性的研究

以自制的生物柴油为助溶剂,研究了生物柴油对乙醇和柴油调和燃料的助溶作用;研究了不同比例的柴油-生物柴油-乙醇调和燃料的理化特性及稳定性。结果表明,当生物柴油含量为12.55%时,柴油和燃料乙醇可以以任意比例互溶;乙醇含量过高会导致燃料的各种理化性能下降;乙醇含量为10%,生物柴油含量>12.55%为混合燃料较为适宜的调和比列。     

Cu-ZnO-Al_2O_3催化剂上甘油氢解制1,2-丙二醇的反应动力学(英文)

A series of Cu-ZnO-Al2O3 catalysts with various metal compositions of Cu/Zn/Al were prepared by the co-precipitation method,and screened for glycerol hydrogenolysis to propylene glycol.The catalyst with a Cu/Zn/Al molar ratio of 1:1:0.5 exhibited the best performance for glycerol hydrogenolysis,and thus selected for kinetic investigation.Under elimination of external and internal diffusion limitation,kinetic experiments were performed in an isothermal fixed-bed reactor at a hydrogen pressure range of 3.0-5.0 MPa and a temperature range of 493-513 K. Based on a dehydration-hydrogenation two-step hydrogenolysis mechanism,a two-site Langmuir-Hinshelwood kinetic model taking into account competitive adsorption of glycerol,acetol and propylene glycol was proposed and successfully fitted to the experimental data.The average relative errors between observed and predicted outlet concentrations of glycerol and propylene glycol were 6.3%and 7.6%,respectively.The kinetic and adsorption parameters were estimated by using the fourth-order Runge-Kutta method together with the Rosenbrock algorithm.The activation energies for dehydration and hydrogenation reactions were 86.56 and 57.80 kJ·mol-1,respectively.