共查询到18条相似文献,搜索用时 78 毫秒
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研究了餐饮废油在甲醇钠的催化作用下制取生物柴油的工艺条件,实验表明其酯交换过程的最佳工艺条件是醇油物质的量比为7∶1、反应时间为1.5 h、催化剂质量为废油的1.5%及反应温度为60℃。通过对生成的生物柴油作理化性质检测,结果表明,其质量指标完全符合柴油优级品的标准。 相似文献
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以植物油脚-皂脚为原料,采用酸化、酯化、酯交换的方法来制取生物柴油。通过正交实验得到酸化植物油脚-皂脚与甲醇酯化、酯交换的最佳工艺条件:醇油脚比为6∶1,催化剂用量4%,反应温度65℃,反应时间4 h,脂肪酸甲酯的收率达到76.8%,酸值为0.5 mg KOH/g。制备的生物柴油,其主要性能指标与0#柴油接近,比其他柴油组分的调和性好,具有较好的社会经济效益。 相似文献
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直接从脂肪醇的分子结构提取了三个结构参数碳碳键的个数Nc—c,羟基所连接碳原子上的氢原子个数α—H和烷基极化效应指数PEI,来与59种脂肪醇的溶解度进行相关分析,得到方程:-lgSw=-0.9734PEI+0.5821Nc—c+0.2011α—H-1.0015。该方程相关系数达到了0.9939,标准偏差仅为0.1933。运用留一法确证该方程具有一定的稳定性和较好的预测能力。该方程所运用参数计算简单,物理意义明确,能够被广泛使用。 相似文献
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在50℃、46℃和常压下实验测定了对苯二酚在二异丙基醚和苯酚中的饱和溶解度。把它与水-二异丙醚-苯酚-对苯二酚四元系中的对苯二酚浓度作比较,其最大溶解度既小于醚相也小于水相中对苯二酚的最大浓度,这一结果可能意味着水有增溶作用。 相似文献
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研究化合物水溶解性对控释亲水骨架系统释放动力学的影响.采用搅拌策法测试卡巴咪嗪及扑热息痛从亲水骨架片中的溶出速率,并对测量数据分别进行线性及非线性回归分析,得出低水溶性化合物(例如卡巴咪嗪)的释放动力学通常为零级过程,而水溶性适中的化合物(如扑热息痛)释放过程则呈异常扩散的结果.研究表明亲水骨架系统的释放动力学特征取决于化合物的水溶解性. 相似文献
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Experimental study has been conducted to determine the solubility of natural gas in liquid at temperatures of 293.15, 298.15, 303.15 and 313.15 K at atmosphere pressure. Ethanol, n-bexane and n-heptane were selected as solvents in the experiment. The solubility data of methane in the mixing solvents were determined and the experimental data were calculated with the PR and PRSV equation of state(EOS). The calculated average absolute deviations for the two kinds of ternary systems CH4/n-C6H14-C2H6O and CH4/n-C7H16-C2H6O are 1.92% and 1.85% for PR EOS and 2.11% and 1.87% for PRSV EOS, respectively. 相似文献
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通过考察硝酸硫胺重结晶过程中的各关键组分的浓度变化 ,建立了硝酸硫胺的溶解度模型 ,模型预测结果与实验结果吻合很好 .该模型的建立对于研究结晶过程中的成核和晶体成长过程具有重要意义 ,也为类似的沉淀结晶过程提供了一种研究方法 相似文献
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王建鸣 《黄冈师范学院学报》2004,24(3):81-83
实验采用分光光度法测定PbI2的溶度积原理是用NaNO2将PbI2饱和溶液中的I-氧化成I2,测定其吸光度,并在标准曲线上查找出对应的I-浓度.计算出PbI2的溶度积常数为KSP=1.37×10-8,与文献值相比误差较小. 相似文献
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Enhancing the dispersion and dissolution of substrate particles in substrate water suspension is a feasible way to improve steroid bioconversion. The aim of the present study is to investigate the effects of applying surfactant to microbial conversion system on the dispersion, solubilization and in turn bioconversion of steroid substrate. The model system is hydroxylation of substrate 19α- 17α-epoxy- 4-pregnene- 3.2It-dine by microbial enzymes from Rhizopus nigricanl. The results show that the presence of substrate leads to an increase in critical micelle concentration ( CMC) of surfactant PSE compared with the normal CMC of PSE in aqueous solution. The grinding time during substrate suspension preparation affects the substrate aqueous solubility differently with the varied surfactant concentrations while barely making any difference in substrate solubility in the absence of surfactant. The properly prolonged grinding time can make up for the loss in substrate solubility arising from the reduction in surfactant concentration. The surfactant complexes composed of surfactants PSE and MGE at appropriate ratios are screened out with orthodoxy experiment method. the interaction between PSE and MGE exerts the most prominent effects on substrate bioconversion, and the surfactant complexes show more beneficial effects on steroid bioconversion than the surfactant PSE used alone. 相似文献