降低FCC汽油烯烃含量研究进展

介绍了降低催化裂化(FCC)汽油烯烃含量反应的基本原理,分析了降低FCC汽油烯烃含量的方法。针对我国FCC汽油中烯烃含量高及汽油调和组分中FCC汽油所占比例过大,导致成品汽油中烯烃含量高的现象,可调整优化FCC技术,并采用新型降烯烃催化剂。要从根本上解决问题,必需对汽油生产结构进行调整,多建催化重整、烷基化和异构化装置,减少成品汽油中FCC汽油的比例。     

催化裂化汽油降烯烃技术研究进展

从FCC技术、醚化改质技术、芳构化改质技术等方面介绍了催化裂化汽油降烯烃技术的发展状况。对FCC自身进行改造的方法简单易行;轻汽油醚化和芳构化改质技术不仅降低了汽油的烯烃含量,同时可以大大提高汽油的辛烷值,但汽油中醚类及芳烃的含量都有一定的限制。目前要降低汽油烯烃含量,需要发展一整套综合技术或措施,然而要从根本上解决问题,必须对汽油的生产结构进行调整,降低催化裂化汽油的比重,增加烷基化、异构化、芳构化、重整等汽油的比例。     

催化裂化汽油降烯烃技术研究进展

随着环保意识的不断增强，对汽油中烯烃含量的限制越来越严格。针对近期的发展动态，从FCC技术、醚化改制技术、芳构化技术等方面介绍了催化裂化汽油降烯烃技术的发展状况。对FCC自身进行改造的方法简单易行；轻汽油醚化芳构化改制技术不仅降低了FCC汽油的烯烃含量，同时可以大大提高汽油的辛烷值，但汽油中醚和芳烃的含量都有一定限制；要从根本上解决问题，还要对汽油的生产结构进行调整，降低催化裂化汽油的比重，增加芳构化、烷基化、重整等汽油的比例。     

FCC汽油降烯烃技术进展

概述了FCC汽油的特点，分析了FCC汽油降烯烃的方法应该具有的技术特征，介绍了FCC汽油降烯烃催化剂和助剂的开发应用情况，重点介绍了降低汽油烯烃含量的FCC新工艺，主要是MGD工艺、MIP工艺、FVI工艺、TSRFCC工艺和FDFCC工艺等。     

FCC汽油改质降烯烃技术综述

随着对环保问题的日益重视,人们对燃料的要求也越来越高,降低FCC 汽油中的烯烃含量迫在眉睫。本文从FCC 汽油降烯烃技术的反应机理出发,介绍了国内外最近为降低汽油中烯烃的含量所开发的新技术、新型催化剂及助剂,并根据我国当今发展状况提出了今后FCC 汽油降烯烃技术的发展方向。     

催化裂化汽油降烯烃技术的现状及发展

随着环保意识的不断增强,对汽油中烯烃含量的限制越来越严格。针对这一情况和我国汽油池的特殊性,提出了现阶段我国催化裂化汽油降烯烃工艺需要达到降烯烃幅度大,辛烷值损失小,高液收,和低硫要求。本文介绍了目前国内外主要的降低FCC汽油烯烃技术的发展状况及其工艺技术的改进等。通过上述措施,不仅降低了FCC汽油的烯烃含量,同时可以提高汽油的辛烷值,要运用这些技术还要结合各自装置的实际情况。但是要从根本上解决问题,还要对汽油的生产结构进行调整,降低催化裂化汽油的比重,增加芳构化、烷基化、重整等汽油的比例。     

降低我国车用汽油烯烃含量的措施探讨

降低我国车用汽油烯烃含量的关键是降低催化裂化汽油的烯烃含量,而国内目前广泛采用的在催化裂化装置上使用降烯烃催化剂的方法是降低FCC汽油烯烃含量,此外国内开发的一些新型的催化裂化反应工艺,如MIP、MGD、FDFCC等也能明显降低FCC汽油的烯烃含量。指出为了进一步降低汽油烯烃含量,以应对更加严格的车用汽油标准,我国炼油业应在大力推行加氢工艺的基础上优化加工流程,发展重整、烷基化、醚化等多种工艺,彻底改变我国车用汽油池组成单一的现状。     

FCC汽油脱硫降烯烃技术最新进展

介绍了国内外降低催化汽油中硫和烯烃的技术。降低FCC汽油烯烃和硫含量的主要技术有对FCC原料油进行加氢预处理、在FCC过程中使用具有降低汽油烯烃和硫含量的催化剂或助剂以及对 FCC 汽油进行脱硫和降烯烃精制处理三类。     

催化裂化汽油降烯烃技术进展

随着环保法规的日益严格,清洁汽油的需求也越来越大。长期以来,催化裂化装置在我国原油的二次加工中占有非常重要的地位。而催化裂化汽油烯烃含量高达50%左右,难以满足清洁汽油发展要求。本文基于催化裂化工艺(FCC)特点,介绍了改进工艺操作条件和原料条件、改变FCC工艺过程,改进FCC催化剂等三方面技术降低汽油烯烃含量。     

流化催化裂化汽油改质和增产低碳烯烃的研究

采用GL型催化剂,在小型固定流化床实验装置上考察了反应温度、剂油比、空速和水油比等操作条件对流化催化裂化(FCC)汽油催化改质汽油的产品分布、低碳烯烃(丁烯、丙烯和乙烯)产率和族组成的影响。实验结果表明,在一定反应条件下,FCC汽油通过催化改质可以降低烯烃含量,提高芳烃含量和辛烷值,在满足新汽油标准的同时提高了低碳烯烃的产率。此外,较高的反应温度、剂油比和水油比以及较低的空速有利于FCC汽油催化改质和增产低碳烯烃。     

佛山市顺德新城区降水中污染物的监测和分析

为掌握佛山市顺德新城区降水中污染物的情况,2015年7月至8月,文章作者分别在雨天进行了降水取样,对降水中的pH、电导率、常见阴离子(F-、Cl~-、NO_3~(2-)、SO_4~(2-))及部分重金属(铅和镉)进行监测分析。选择有相关数据的珠江三角洲和石家庄、厦门等地的降水中污染物的情况进行对比。结果表明,顺德新城区降水中的p H和部分阴离子浓度优于珠江三角洲平均值,酸雨类型属于硫酸和硝酸混合型;其水体洁净程度略差于石家庄;铅和镉的浓度也高于厦门,甚至部分超出了人体能直接接触的安全范围。     

Metabolism of trideuterated iso-lignoceric acid in rats in Vivo and in human fibroblasts in culture

Saturated very long chain fatty acids (fatty acids with greater than 22 carbon atoms; VLCFA) accumulate in peroxisomal disorders, but there is little information on their turnover in patients. To determine the suitability of using stable isotope-labeled VLCFA in patients with these disorders, the metabolism of 22-methyl[23,23,23-²H₃]tricosanoic (iso-lignoceric) acid was studied in rats in vivo and in human skin fibroblasts in culture. The deuterated iso-VLCFA was degraded to the corresponding 16- and 18-carbon iso-fatty acids by rats in vivo and by normal human skin fibroblasts in culture, but there was little or no degradation in peroxisome-deficient (Zellweger’s syndrome) fibroblasts, indicating that its oxidation was peroxisomal. Neither the 14-, 20-, and 22-carbon iso-fatty acids nor the corresponding odd-chain metabolites could be detected. In the rat, the organ containing most of the iso-lignoceric acid, and its breakdown products, was the liver, whereas negligible amounts were detected in the brain, suggesting that little of the fatty acid crossed the blood-brain barrier. Our data indicate that VLCFA labeled with deuterium at the ω-position of the carbon chain are suitable derivatives for the in vivo investigation of patients with defects in peroxisomal β-oxidation because they are metabolized by the same pathways as the corresponding n-VLCFA. Moreover, as iso-VLCFA and their β-oxidation products are readily separated from the corresponding n-fatty acids by normal chromatographic procedures, the turnover of VLCFA can be more precisely measured. A preliminary report of part of this work (Reference 18) was presented at the 5th International Symposium on the Synthesis and Applications of Isotopes and Isotopically Labelled Compounds, Strasbourg, France, June 20–24, 1994.     

高效液相色谱法分析化妆品中微量成分的研究进展

综述了高效液相色谱法在化妆品中防腐剂、防晒剂中紫外线吸收剂以及性激素的检测等几个方面的应用;同时,介绍了分析所用的色谱柱、流动相、使用的检测手段以及样品的提取方法;最后针对目前存在的问题,提出了高效液相色谱用于化妆品中微量成分分析的研究方向和发展前景。     

Denitrification in shallow groundwater in a coastal agricultural area in Japan

In a coastal agricultural area in the central part of Japan (Shizuoka), we found decreasing nitrate concentration with depth in a shallow groundwater, where the depth to water table varied between 0.6 and 1.2 m below ground surface. High nitrate concentrations (5–29 mg N L^–1) were often observed in the upper layer (0–2 m) of the groundwater, but the concentration decreased to less than 1 mg N L^–1 in the deeper layer. Ammonium was scarcely detected, and the concentration of dissolved oxygen was usually low (< 1 mgO₂ L^–1) in the groundwater. Nitrate in the groundwater often had very heavy nitrogen stable isotope ratios (>20{}). There was a negative relationship between nitrogen stable isotope ratio of nitrate and its concentration. When nitrate was injected into the groundwater with acetylene and bromide (a conservative tracer), nitrate concentration decreased to 20% of the initial level within 5 days, accompanied by the increase in nitrite and nitrous oxide concentration and a little change in bromide concentration. These results indicate that microbial denitrification plays a potential role in the decrease of nitrate in shallow groundwater at the study site.     

我国硝酸工业生产技术新进展

系统叙述了我国硝酸工业2000-2007年生产现状及主要技术成果,尤其指出了国产"四合一"机组的成功投运,使我国硝酸国产化装置取得较大的进步,表现在吨酸的铂耗、氨耗和能耗等方面接近国外引进装置水平,同时介绍了国外双加压法硝酸生产技术的进展.我国已成为硝酸生产大国,仍需以先进的技术改造和发展我国硝酸工业,确保我国硝酸工业健康有序地发展,加快从硝酸生产大国向强国迈进的步伐.