油脂催化加氢转化制备第二代生物柴油研究进展

生物柴油是一种清洁的可再生能源,是应对温室效应、环境污染、能源短缺等问题最有潜力的发展方向之一。第二代生物柴油是油脂与氢气(H_(2))进行加氢转化反应制得的与传统石化柴油组成类似的烃类混合物,除具有绿色环保、十六烷值高、可再生等优点外,还具有低温流动性好、含氧量低、稳定性高、热值高等特点,可与石化柴油无比例限制地混合使用。系统总结了近年来油脂催化加氢转化制备第二代生物柴油方面的研究进展,包括加氢转化机理、催化剂活性相、催化剂载体和加氢转化工艺四个方面,着重介绍高效加氢转化催化剂的设计和开发。此外,还分析了油脂催化加氢转化制备第二代生物柴油领域所面临的机遇和挑战,并对未来的发展方向进行了展望。

Preparation of modified LiMn_(2)O_(4) by solid-state reaction

Modified lithium manganese oxides were prepared by solid-state reaction of LiMn_(2)O_(4)and LiCoO_(2)as raw materials.A study was carried out by TG-DSC,XRD,DSC and electrochemical to analyse the reaction process and structural characterization of products.The results show that the LiMn_(2)O_(4)reacts chemically with LiCoO_(2)at high temperature.All of Li and partial Co atoms can insert into the LiMn_(2)O_(4)crystal lattice and a newly formed spinel phase-modified LiMn_(2)O_(4)was obtained.The distribution of Co content is even in modified LiMn_(2)O_(4)compound.The modified LiMn_(2)O_(4)compound exhibits improved cycling stability at room and elevated temperature in comparison with the pure LiMn_(2)O_(4).

低浓度铷的萃取分离试验研究

针对低品位含铷矿石的低铷高钾、钠浸出液,研究了采用溶剂萃取法分离铷和钾、钠,考察了萃取剂浓度、料液碱度、相比等对萃取分离效果的影响,并进行了串级模拟试验。有机相为1.0 mol/L t-BAMBP+二甲苯,料液碱度N k为0.8~1.0,洗涤剂为纯水,反萃取剂为1 mol/L盐酸。结果表明:在萃取相比(VO/VA)为3/1、洗涤相比(VO/VA)为5/1、反萃取相比(VO/VA)为10/1,萃取、洗涤和反萃取时间均为2 min,3级萃取、7级洗涤、2级反萃取条件下,铷与钾、钠得到较好分离,反萃取液中[Rb^+]/[K^+]和[Rb^+]/[Na^+]为476,铷回收率达87%。