Physical solvent extraction of levulinic acid from dilute aqueous solution with 2-methyltetrahydrofuran

The results of the present investigation reveal that 2-methyltetrahydrofuran is a potential solvent for the extraction of levulinic acid from dilute aqueous solution. This conclusion is based on the relatively high values of distribution coefficient K_d (1.3-1.6) measured for the system of levulinic acid – water – 2-methyltetrahydrofuran at temperatures 298.2 K, 313.2 K, and 328.2 K, as well as encouraging performance of the continuous counter current Kühni column. The results give reason to believe, that 2-methyltetrahydrofuran can be considered for the extraction of other low molecular weight acids, such as formic or lactic acid, as well.     

Solvent and Extraction Conditions Control the Assayable Phenolic Content and Antioxidant Activities of Seeds of Black Beans,Canola and Millet

The effects of extraction solvent and conditions on the total phenolic content (TPC) and antioxidant activity of black beans, canola and foxtail millet were investigated. The antioxidant activity was assayed using 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging activity (DRSA) and oxygen radical absorbance capacity (ORAC). Four solvent systems, namely 70 % acetone, 80 % ethanol, 80 % methanol and a mixture of acetone/methanol/water (7:7:6, v/v/v) were used. The extraction methods adopted in this study included refluxing, homogenization, cold extraction and sonication. The TPC as measured using the Folin Ciocalteu's method were 12.35–28.39, 2.43–16.73, and 1.78–5.06 µmol catechin equivalents/g dry matter (dm) for canola, black beans and foxtail millet, respectively. Aqueous acetone afforded the highest TPC for black beans and canola. Within the same solvent system used, the TPC, DRSA and ORAC obtained from different extraction techniques differed for black beans, canola and foxtail millet. The results demonstrated that the solvent system as well as method influenced the extraction of phenolic compounds and their antioxidant activities, depending on the type of matrix in which phenolics were embedded.     

水杨酸在超临界二氧化碳中络合萃取汞离子

测试水杨酸在超临界二氧化碳中的溶解度数据,研究了水杨酸络合剂在超临界二氧化碳中萃取汞离子,分别讨论了配比、压力、温度、时间对萃取效率的影响。得到了最佳的萃取条件为20 MPa、323 K、45 min和[Hg+]:[SAL]:[PFOSANEt4]=1:200:200,在最佳萃取条件下萃取效率达到95.5%,可以进行工业领域的推广应用。水杨酸作为络合剂在超临界二氧化碳中萃取汞离子的研究未见有关报道。     

HDEHP从硝酸底液中萃取UO_2~(2+)动力学研究

本文采用上升液滴法研究HDEHP-煤油溶液从硝酸底液中萃取UO_2~(2+)的动力学。根据本文实验数据,HDEHP萃取UO_2~(2+)的速率可以下列动力学方程表示:R=K[UO_2~(2+)]aq[HA]~2(o)实验测定了改变温度(15至40℃)对萃取速率的影响,用Arrhenius式可求得萃取反应的表观活化能为16.0kJ/mol。由实验结果推测,HDEHP从硝酸底液萃取UO_2~(2+)的反应,可能按下列三步进行:其中反应(1)生成两相界面配合物是萃取速率的控制步骤.     

从碳酸盐型含钨的泥质铀矿石中提取铀及铀钨分离

本文阐述了从含钨泥质铀矿石中回收铀及铀钨分离的试验研究。对碳酸盐含量高的该种矿石,采用加压碱浸、离子交换分离铀、钨和吸附后溶液全部返回浸出回路的流程,可获得部颁一级品重铀酸铵产品,并使浸出剂碳酸钠的用量大幅度降低。     

高浓铀脉冲筛板塔溶剂萃取过程自动控制研究

本文主要叙述了高浓铀塔式萃取自动控制系统在衡阳铀厂扩大试验中的运行情况，着重阐述 了自动化仪器、仪表的使用，自动控制回路及脉冲筛板塔溶剂萃取过程最佳回控点等。作者指出了 这次实验的成功之处，也提出了在今后生产应用中，自动控制、仪器仪表方面应该注意的一些问 题。     

萃取体系反向胶束和W／O微乳液的形成

本文评述了国内外学者在萃取体系反向胶束和微乳液领域的研究成果。探讨了胺类萃取和协同萃取体系中反向胶束的形成对萃取分配比的影响，以及某些萃取体系第三相与ＷｉｎｓｏｒⅢ微乳液的关系，并从形成反向胶束或微乳液的角度对萃取规律作了概括。     

利用原料1生产金属化阳极板试验研究

本文介绍了利用原料1在合金硫化炉进行金属化阳极板试验的过程。通过在合金硫化炉中进行原料1硫化、吹炼等试验过程,达到提镍降硫的目的。并在试验过程中摸索出了生产金属化阳极板的关键参数,同时对金属化阳极板中化学成分、镍直收率、钴直收率等关键指标进行了分析,为金属化阳极板的工业化生产提供了理论依据。     

Removal of contaminants from polluted drilling mud using supercritical carbon dioxide extraction

Liquid drilling fluid is often called drilling mud is heavy, viscous fluid mixtures use to carry rock cuttings to the surface and lubricate and cool the drill bit. During carrying cuttings they contaminated which not only reduce their functionality but also make them a hazardous and dangerous wastes which cannot be discharged anywhere without treatment. Due to this fact, in the present study, supercritical extraction process was used to remove contaminants from the drilling mud. Regarding this, effect of different parameters including extraction temperature (313–338 K) and pressure (100–200 bar), flow rate of CO₂ (0.05–0.36 cm³/s) and static time (20–130 min) on the removal of contaminations from drilling mud was examined using the design of experiment of changing one factor at a time. The obtained results revealed that the optimum operational conditions that lead to the highest removal degree of contaminations are temperature and pressure of 333 K and 180 bar, respectively, flow rate of lower than 0.1 cm³/s and the static time of 110 min. In addition, to examine the effect of the supercritical extraction on the crystalline structure modification and removal contaminations X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses were performed which confirmed the successful removal of contaminations from the drilling mud without significant crystalline modification.     

芹菜膳食纤维制备工艺的探讨

本文采用正交设计法,研究了以榨汁后的芹菜渣为原料来提取芹菜膳食纤维的工艺.分别以产率和不溶性膳食纤维含量为主要指标,寻找碱解与酸解最佳工艺.最佳工艺结果表明:芹菜膳食纤维总产率达79.5%,其中不溶性膳食纤维含量达69.0%,溶胀性为12.2ml /g,持水力为2.11g/g.