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准确地测定聚丙烯酰胺的含量、水解度等各项指标,是研究聚丙烯酰胺驱油的重要工作。实验室内关于聚合物滞留量的研究,需要准确地测定模型进口、出口的聚丙烯酰胺含量,通过物料平衡,计算聚合物在砂岩模型中的滞留量。在聚台物矿场试验中,也要对产出液进行聚合物含量测定。对于矿场试验所用聚丙烯酰胺,应按要求进行各种技术指标的检测,其中聚丙烯酰胺含量及水解度,是两项重要指标。目前,已有一些测定聚丙烯酰胺含量的方法,如“浊度法”,“粘度法”等,但由于聚合物在多孔介质中往往会发生剪切降解,以及采出液中含有油、砂等杂质,这些方 相似文献
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论述了聚丙烯酰胺溶解及水溶液的流动特征,给出了聚丙烯酰胺水溶液管输摩阻与流速,雷诺数、管径的关系,讨论了聚丙烯酰胺减阻效果与浓度的关系以及入口效应,根据实验和理论分析,提出了在管道输送过程的不均匀应力场作用下,具有粘弹性的聚丙烯酰胺水溶液在管道内壁边界层处存在着低粘性流体层。 相似文献
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驱油用超高分子量聚丙烯酰胺的合成 总被引:10,自引:0,他引:10
以丙烯酰胺丙烯酸钠为原料 ,利用一种新型氧化还原引发体系 ,采用水溶液共聚法合成了固含量4 5 .6%、水解度 2 5 .7%、过滤比 1 .32、分子量达 2 .2× 1 0 7的超高分子量聚丙烯酰胺。研究了甲酸钠用量、总单体浓度、p H值、单体配比对聚丙烯酰胺分子量的影响。确定了反应的最佳工艺条件 :单体总浓度 4 5 % ;p H值9.5 ;1 %氧化剂 0 .5 m L;1 %还原剂 1 .0 m L;起始温度 1 0℃ ;0 .1 %甲酸钠 80μL;丙烯酸钠∶丙烯酰胺为 1∶3(摩尔比 ) 相似文献
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大庆炼化公司聚丙烯酰胺装置全套引进法国SNF公司技术与设备,装置设计采用均聚工艺生产阴离子型聚丙烯酰胺。预研磨设备处于生产线反应工艺和造粒工艺之间,其作用是初步粉碎胶体、向造粒机供料。螺杆是预研磨设 相似文献
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高分子量丙烯酰胺-DAC共聚物的研制 总被引:7,自引:0,他引:7
采用复合引发体系 ,以丙烯酰胺 (AM)和阳离子单体丙烯酰氧乙基三甲基氯化铵(DAC)为共聚体 ,进行水溶液绝热聚合 ,研制了一种DAC单体含量为 4 0 %~ 5 0 %、相对分子质量大于 1× 10 7的阳离子型聚丙烯酰胺。 相似文献
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新一代全自动加酸电热板消解仪能有效避免传统电热板存在的酸雾大、易伤害操作人员等问题。湿法消解土壤样品具有操作条件简单、溶剂易挥发、处理成本低等优点,广泛运用于各类土壤样品前处理。处理方法为在0.1 g土壤样品中加入4 mL HNO3、1 mL HF,120℃下加热1 h后再加入1 mL HClO4,140℃下加热1 h后再加入1 mL HClO4,然后在180℃下加热1 h,因大庆油田土壤具有含污油、有机物难去除、易对检测产生干扰的特点,通常需要再加入适量的HF和HClO4,反复消解和赶酸,直至去除污油。经消解处理后的土壤样品采用ICP-MS方法检测,方法的检出限为0.5~2.4 mg/kg,线性范围为0~400μg/L,相对标准偏差为3.9%~6.5%,对照相关国家标准,各项实验结果均满足要求。使用大庆油田的含油土壤样品作为基体,加标回收率为80.5%~110.4%。研究表明,该方法适用于大庆油田的含油土壤样品中Cu、Zn、Ni、Pb、Cd、Cr的测定。 相似文献
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为适应蜡油原料重质化、劣质化发展趋势,延长装置运转周期,采用具有粒子尺寸大且粒径分布集中、相对结晶度高的特种氧化铝载体材料及Ⅱ类活性相调节技术,开发了具有较大孔径和孔体积、更高抗金属和容金属能力的FF-34蜡油加氢处理催化剂。工业应用结果表明:在入口压力10.0 MPa、体积空速高达1.00 h-1、氢油体积比558、入口反应温度仅334℃条件下,精制蜡油硫质量分数约3000μg/g,氮质量分数为1321μg/g,化学氢耗为0.73%,说明了FF-34催化剂具有良好的加氢脱硫和加氢脱氮性能。 相似文献
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针对部分水解聚丙烯酰胺在高矿化度条件下增黏能力下降的问题,采用仪器检测和物理模拟等方法,对具有能够去除或屏蔽水中Ca2+、Mg2+的络合剂进行筛选、复配和评价,并在此基础上,进行流动性实验和驱油效果实验研究。结果表明,10种络合剂中,氨基三甲叉膦酸与羟基乙叉二膦酸对部分水解聚丙烯酰胺具有很好的增黏效果,增黏率达到了30%左右。综合考虑增黏效果、稳黏效果、反应时间和成本等方面因素,将10种络合剂复配,其中,“SY-Ⅰ”络合剂提高初始黏度效果明显,“SY-Ⅱ”络合剂提高黏度稳定性效果明显。与未加络合剂的聚合物溶液相比较,加入络合剂的聚合物溶液分子线团尺寸更大,黏弹性更好,阻力系数和残余阻力系数更大,驱油效果更好。矿场试验表明,加入络合剂的聚合物在驱替过程中注入压力明显提升,采油井的含水明显下降,产油量明显增加,增油降水效果显著。该研究对提高聚合物驱技术经济效益、指导矿场实践应用具有重要意义。 相似文献
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A total of 40 samples of domestic and imported soy sauces with the greatest diversity were investigated for the presence and contents of deoxynivalenol (DON) by using GC–MS after pre-column derivatisation. Results showed that 97.5% of samples investigated were contaminated with DON, and there was a remarkable variation in the DON contents across soy sauce samples. The average incidence rate of DON in domestic soy sauces was 97.1% (range 4.5–1245.6 μg/l, average value 141.5 μg/l), while for those imported from Japan was 100% (range 30.5–238.3 μg/l, average value 113.7 μg/l). Manufacturing process and quality grade were found to have significant influences on the levels of DON in soy sauces. Generally, domestic soy sauces produced with low salt solid state fermentation and with higher quality grade exhibited higher DON contents. The present results also indicated that the exposure to DON from the consumption of soy sauces is at a very low risk level. 相似文献
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Rapid qualitative analysis of phthalates added to food and nutraceutical products by direct analysis in real time/orbitrap mass spectrometry 总被引:1,自引:0,他引:1
Randy L. SelfWen-Hsin Wu 《Food Control》2012,25(1):13-16
A recent food safety issue involves the contamination of a broad range of food and nutraceutical products from Taiwan with industrial plasticizers. Among the suspected contaminants are selected phthalic acid esters, such as benzyl butyl phthalate, dibutyl phthalate, diisobutyl phthalate, di-2-ethylhexyl phthalate, di-n-octyl phthalate, diisononyl phthalate, and diisodecyl phthalate. Described in this study is an analytical method to rapidly qualitatively analyze these compounds in a wide variety of food and nutraceutical matrices suspected in this crisis. The method utilizes direct analysis in real time (DART) ionization coupled to a Thermo Exactive orbitrap mass spectrometer. The method is shown to be capable of detecting these compounds at levels greater than 1.0 μg/mL in all food products examined and 0.5 μg/mL in most of the samples tested. In the nutraceutical samples tested, the compounds were detected at levels of 50 μg/g for all samples with some detected as low as 1.0 μg/g. 相似文献
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《Food Control》2014
Samples of locally (Malawian) processed and imported maize- and groundnut-based food products (peanut butters, roasted groundnuts, peanut based therapeutic foods, instant baby cereals, maize puffs and de-hulled maize flour) were collected from popular markets of Lilongwe City, Malawi. The samples were analysed in order to determine the frequency and extent of aflatoxin contamination, using immuno-affinity column and reversed-phase liquid chromatography with post-column photochemical derivatization and fluorescence detection. No aflatoxins were detected in all samples of imported baby cereal and locally processed de-hulled maize flour. However, all locally processed maize based baby foods had aflatoxins above EU maximum tolerable level of 0.1 μg/kg. In 75% of locally processed maize puffs, aflatoxins were detected at levels of up to 2 μg/kg. Peanut based therapeutic foods had aflatoxin level between 1.6 and 2.9 μg/kg, exceeding the EU tolerable maximum level (0.1 μg/kg) set for food for health purposes. Locally processed peanut butters had aflatoxins levels in the range of 34.2–115.6 μg/kg, which was significantly higher than their imported counterparts (<0.2–4.3 μg/kg). Samples of locally processed skinned and de-skinned roasted groundnuts had aflatoxins in range of 0.5–2.5 μg/kg and 0.6–36.9 μg/kg, respectively. These results highlight the need for rigorous monitoring of aflatoxins in commercially available processed products in order to reduce likely health risks associated with dietary aflatoxin intake. 相似文献
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利用石墨炉原子吸收法测定不同批次的水处理剂聚合硫酸铁中痕量镉的含量。镉在0.2μg/L~1.2μg/L范围内具有较好的线性关系,测试结果相对标准偏差为1.2%,回收率在95.0%~101.0%,测试具有较好的精密度和回收率,具有一定的实用价值。 相似文献