共查询到17条相似文献,搜索用时 187 毫秒
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以强酸性阳离子交换树脂NKC-9为催化剂、乙二胺四乙酸二钠(EDTA-Na2)为助催化剂,使用低浓度双氧水与甲酸原位反应生成过氧甲酸(PA);以PA为氧化剂、玉米原油为原料合成环氧玉米油。考察了EDTA-Na2、NKC-9、双氧水、甲酸溶液的用量,反应温度,反应时间对环氧化反应的影响,确定了最佳反应工艺条件为:EDTA-Na2、NKC-9、双氧水、甲酸溶液的用量分别为玉米原油质量的0.01%、13%、110%、17%,反应温度55℃,反应时间6 h。在最佳反应条件下,环氧玉米油的环氧值达到6.49%,环氧率为85.85%,未反应率为2.83%,开环率为11.32%;与传统硫酸催化工艺相比,使用NKC-9催化产品的环氧率比硫酸催化高,并且开环率低约0.7个百分点。 相似文献
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以强酸性阳离子交换树脂NKC-9为催化剂、乙二胺四乙酸二钠(EDTA-Na2)为助催化剂,使用低浓度双氧水与甲酸原位反应生成过氧甲酸(PA);以PA为氧化剂、玉米原油为原料合成环氧玉米油。考察了EDTA-Na2、NKC-9、双氧水、甲酸溶液的用量,反应温度,反应时间对环氧化反应的影响,确定了最佳反应工艺条件为:EDTA-Na2、NKC-9、双氧水、甲酸溶液的用量分别为玉米原油质量的0.01%、13%、110%、17%,反应温度55℃,反应时间6 h。在最佳反应条件下,环氧玉米油的环氧值达到6.49%,环氧率为85.85%,未反应率为2.83%,开环率为11.32%;与传统硫酸催化工艺相比,使用NKC-9催化产品的环氧率比硫酸催化高,并且开环率低约0.7个百分点。 相似文献
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以甲酸为活性氧的载体、硬脂酸为催化剂,在超声条件下对大豆油进行环氧化,考察了甲酸、硬脂酸用量,双氧水与甲酸摩尔比以及超声频率,超声功率,超声温度,超声时间等因素对大豆油环氧值的影响。确定的最佳反应条件为:甲酸用量为大豆油质量的20%,硬脂酸用量为大豆油质量的2.0%,双氧水与甲酸的摩尔比7.76∶1,超声频率28 kHz,超声功率120 W,超声温度65℃,超声时间30 min。在最佳反应条件下得到的环氧大豆油环氧值为5.93%,比相同反应时间内非超声反应得到的环氧大豆油环氧值提高了17.19%,而且在达到相同环氧值时,超声条件比非超声条件的反应时间缩短了一半。 相似文献
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以磷钨酸为催化剂,考察了乳化剂季铵盐的种类对合成环氧大豆油的影响。其中,十六烷基三甲基氯化铵的效果相对较好。结合磷钨酸的催化性能与十六烷基三甲基氯化铵的乳化性能,实现大豆油的高效环氧化,且易溶于反应体系的磷钨酸与十六烷基三甲基氯化铵可原位生成不溶的磷钨酸季铵盐固体,易于与产物分离。此外,也考察了反应温度、甲酸用量、双氧水用量、磷钨酸与十六烷基三甲基氯化铵的总用量和反应时间对合成环氧大豆油的影响。在大豆油:甲酸:双氧水:磷钨酸:十六烷基三甲基氯化铵=1: 0.12: 1.20: 0.0062: 0.002(以大豆油的质量为基准),反应温度70℃,反应时间6h的优化条件下,合成的环氧大豆油环氧值为6.15% ,碘值为2.46%。经FT-IR表征,大豆油的不饱和键已基本转化为环氧大豆油的环氧基团。 相似文献
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以大豆油为原料,氯化胆碱-甲磺酸形成的低共熔溶剂为催化剂,考察反应温度、催化剂用量、乙酸用量、过氧化氢用量及反应时间等因素对环氧化反应的影响,并通过响应面分析法优化环氧大豆油制备工艺。研究表明,氯化胆碱-甲磺酸低共熔溶剂具有较好的催化环氧化反应性能,以其为催化剂,并通过响应面分析法优化的环氧大豆油最佳合成条件为:反应温度73 ℃,催化剂量4.8 wt%,H2O2用量为72 wt%,反应时间3.6 h,乙酸用量9 wt %,此条件下,环氧大豆油的环氧值为6.98,该结果与模型预测值基本相符。 相似文献
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G. N. BOOKWALTER H. A. MOSER L. T. BLACK E. L. GRIFFIN JR. 《Journal of food science》1971,36(5):737-741
SUMMARY —CSM is a high-protein food supplement for infants and preschool children; it consists of partially gelatinized corn meal, toasted soy flour and nonfat dry milk and is fortified with vitamins and minerals. The original CSM formulation contained only 2% fat. Storage stability characteristics were determined for CSM blends containing as much as 6% fat. The fat sources tested were corn germ, full-fat soy flour, refined soybean oil, expeller crude corn oil and a combination of high-fat corn meal with full-fat soy flour. Tests for changes in flavor, free fatty acids, peroxide values and available lysine were made on blends stored at 120°F for 56 days, 100°F for 6 months and 77°F for 1 year. Higher fat content was associated with improved palatability. Flavor scores declined at about the same rate under all test conditions. In experimental blends containing crude corn oil, palatability varied with the particular sample tested. One sample of crude corn oil was satisfactory while another caused off-flavors in the blends. 相似文献
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The production and stability of glyoxylic acid was followed during the storage of tartaric acid solutions under various conditions. The solutions were prepared both with and without ethanol. Quantification of glyoxylic acid and other oxidation products, including hydrogen peroxide and formic acid, were performed using ion exclusion chromatography. Glyoxylic acid was only detected in tartaric acid samples that had been stored outdoors and sunlight was identified as the critical component of outdoor storage that allowed its formation. The hydrogen peroxide and glyoxylic acid generated under these conditions were of limited stability due to their reaction with each other to produce formic acid. The concentration of the glyoxylic acid was greatly increased when ethanol was omitted from the sample matrix. Copper(II) enhanced the stability of glyoxylic acid but slowed its production. The reaction pathway responsible for the sunlight-induced production and subsequent stability of glyoxylic acid is discussed. 相似文献
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研究过甲酸制备过程中反应时间、反应温度、甲酸浓度和过氧化氢用量对活性氧转化及稳定性的影响。结果表明:随反应时间的延长,过甲酸活性氧含量先升高,然后降低;随反应温度的升高,过甲酸的生成速率和分解速率同时提高;随甲酸浓度的增加,过甲酸活性氧含量升高;随过氧化氢用量的增加,过甲酸活性氧含量几乎成比例增加。 相似文献