多晶硅副产物四氯化硅的利用

随着绿色能源太阳能的大规模开发利用,光伏电池原料多晶硅的用途越来越广泛.生产多晶硅的方法以西门子法用的最广,在生产多晶硅原料三氯氢硅的过程中会产生大量的副产物四氯化硅,其对环境的污染相当严重,如何处理这些副产物,这个问题亟待解决.介绍了多种四氯化硅的再利用方法,如可以用来制造气相白炭黑,合成有机硅产品,制备高纯光纤,用...     

Studies in autoxidation Part I. The volatile by-products resulting from the autoxidation of unsaturated fatty acid methyl esters

The by-products produced during the autoxidation of the methyl esters of three unsaturated fatty acids, under the influence of a number of promoters, have been studied. The components of the by-products have been separated and identified using GC-MS methods. Mechanisms are proposed to account for their formation.     

间苯三酚法合成TATB产品中副产物的鉴定及性能表征

为研究间苯三酚法合成无氯TATB副产物对TATB性能的影响,采用柱层析法将TATB中含有的微量副产物进行了有效分离,结合红外光谱、质谱及核磁对分离得到的副产物进行定性分析;通过差示扫描量热法、热失重法研究TATB及副产物的热分解性能;基于密度泛函数理论计算了TATB及副产物的部分爆轰性能参数。结果表明,TATB中含有的副产物为1-氨基-3,5-二乙氧基-2,4,6-三硝基苯(AETB)和1,3-二氨基-5-乙氧基-2,4,6-三硝基苯(EDATB);副产物的热分解性能与TATB间存在一定差异,TATB及副产物均只有一个热失重过程,但副产物失重过程的起始温度及速率远低于TATB;在相同升温速率下,AETB和EDATB的放热分解峰温分别比TATB低109.2℃和121.4℃;TATB仅在较高温度下存在一个放热分解的过程,副产物EDATB和AETB在较低温度下均存在明显的吸热熔化现象,温度继续上升到一定值后逐渐发生放热分解,副产物的热安定性远低于TATB;由密度泛函理论计算获得副产物的爆热值与TATB十分接近,但是密度、爆速及爆压值均低于TATB。     

Computer-assisted prediction of by-products for industrial organic reactions

Prediction of by-products for industrial reactions is central to the design of chemical process plants. By-products are formed in every chemical reaction used to transform raw materials into desired products. It is important for the designer to know what by-products can possible form, in the event that they are explosive or toxic in nature. Also, since the formation of by-products is related to the reaction conditions, attempts to optimize the process conditions requires knowledge about the type and amounts of the by-products formed.In this paper, the problem of predicting by-products has been formalized. An interactive computer program named PRODUCTS, an acronym for Prediction of Reasonable Organic Derivatives Using Computer Techniques has been developed to predict the by-products formed in organic reactions. The program uses a data-base of sub-structure and mechanistic reactions to generate possible by-products.By-products have been generated by the PRODUCTS program for an alkane oxidation example.     

管网中的饮用水消毒副产物研究进展

控制管网中消毒副产物生成是研究热点,对管网消毒副产物变化规律进行研究,可为控制管网消毒副产物提供指导。在管网中,余氯、季节变化和管材是影响管网消毒副产物的重要因素,余氯量越大,THMs和HAAs的量就越多;季节变化主要会影响化学作用和微生物活性,消毒副产物的生成速率随温度的升高而显著加快,夏秋生成的消毒副产物更多,春冬生成的消毒副产物相对少一些;铁管的腐蚀能使消毒副产物增加,但产生的Fe2＋也能使部分消毒副产物被还原。HAAs与AOC前体物间具有相似性,含量呈正相关性,存在较好的线形关系。     

Agriculture wastes. A source of bulk products?

Biotechnological production processes for low-molecular bulk chemicals can only compete with their petrochemical counterparts on using inexpensive raw materials, e.g., agricultural by-products or wastes, otherwise requiring disposal. The upgrading of by-products/wastes of potato starch production and the use of potato protein liquor and potato pulp for the production of bulk chemicals were investigated. It transpired that the economy of these processes depends on the waste disposal costs of the upgrading processes. In addition, it is shown that specialty chemicals can be produced economically from wastes. However, since they are produced in a large quantities, the upgraded product cannot be put on the market without ruining existing prices.     

栲胶脱硫副产物对脱硫液粘度的影响

模拟栲胶脱硫液中副产物的积累过程,配制了含有不同浓度副产物的仿栲胶脱硫液,考察了栲胶脱硫液中Na2SO4、Na2S2O3、NaHCO3、NaSCN等副产物对脱硫液粘度的影响。结果表明,这些副产物的积累均会使栲胶脱硫液粘度增大,其中Na2S2O3和NaSCN是影响栲胶脱硫液粘度的主要因素;讨论了脱硫液粘度与主要副产物浓度之间的关系,用Excel软件进行了回归分析,得到很好的线性关系,为实际生产中估算栲胶脱硫液的粘度提供了一定的理论依据。     

利用生产钛白粉的废酸和低品位软锰矿生产硫酸锰

介绍用生产钛白粉的废酸和低品位软锰矿为原料生产应用广泛的硫酸锰的方法。该法对生产钛白粉的废酸和因杂质含量高难以开发利用的副产物硫酸亚铁的治理及低品位软锰矿的利用开辟了新路。     

By-products Formation during the Ozonation of the Reactive Dye Uniblu-A

The degradation by ozone of the hydrolyzed Uniblu-A (Uniblu-OH), i.e. the compound found in the spent bath resulting from dyeing process with the reactive dye Uniblu-A, has been studied with the aim of identifying intermediate as well as end by-products formed. The experimental results, obtained by ozonating (16 mg O₃/L in the feed gas at 100 mL/min) aqueous solutions (500 ml) of Uniblu-OH (40 mg/L), in the presence or not of t-butanol, show that the oxy-dye is completely removed within 30 minutes and that its decay results only slightly affected by the presence of t-butanol. Several organic by-products have been identified by liquid chromatography-mass spectrometry (turboionspray interface) as a result of the oxy-dye degradation. Such by-products result from oxidation of the amino group, hydroxylation of the aromatic rings, cleavage of the alkyl chain, cleavage of the sulfoalkylbenzene group leaving substituted anthraquinone structures and cleavage of the latter structures leading to phthalic acid. Such by-products are further degraded leading to the formation of low molecular weight aldehydes and acids, nitrate and sulphate. As for the formation of inorganic end by-products, after 120 minutes of ozonation, the percentages of nitrate and sulphate conversion resulted 6 and 7 %, 53 and 89% in the absence and in the presence of t-butanol respectively.     

乳化炸药用油相材料的研究

对一种炼油副产品作为乳化炸药油相材料的可行性进行了研究。该炼油副产品价格低廉,可降低乳化炸药的生产成本。通过对乳化效果、乳化基质稳定性以及敏化效果进行实验发现,此种炼油副产品能取代目前的油相材料制备乳化炸药。将炼油副产品和机械油、微晶蜡复配具有较强的乳化效果,所制备的乳化基质稳定性较好。此外,采用炼油副产品制备的乳化基质可按目前的敏化配方和工艺进行敏化。     

铬盐生产过程中含铬副产物的综合利用

系统介绍了含铬芒硝、含铬硫酸氢钠及含铬铝泥等多种利用方法的原理、特点及效果，并提出了体会与建议     

Selectivity in the electrochemical epoxidation of propylene

The distribution of by-products produced during the indirect epoxidation of propylene in a bipolar trickle tower has been measured. The distribution changed with both propylene oxide concentration (time) and operating conditions, however, the selectivity with respect to the major product always remained high (c. 97%). Mechanisms giving rise to the important by-products are discussed.     

Studies in autoxidation Part III. The synthesis and autoxidation of some novel dienes

6,9-Pentadecadiene, 8-methyl-6,9-pentadecadiene and 8,8-dimethyl-6, 9-pentadecadiene have been synthesised. The by-products resulting from the autoxidation of these novel dienes under the influence of two promoters have been examined using GC-MS methods. The by-products have been compared with those derived from the autoxidation of naturally occurring fatty acids, and mechanisms have been proposed to account for their formation.     

Influence of Industrial and Agricultural by-Products as Cementitious Blends in Self-Compacting Concrete – A Review

Silicon - Globally, the annual generation of industrial and agricultural by-products is exceeding a thousand million tons and forecasted to tremendously inflate in the future. The by-products are...     

The Determination of Carbonyl Compounds in Ozonated Water by the PFBOA Method

PFBOA, O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine, is excellent as a derivatizing agent in the GC determination of carbonyl compounds in ozonated water samples. Surface and waste waters have been ozonated. The carbonyl ozonation by-products were identified as PFBOA derivatives by gas chromatography-mass spectrometry. The main by-products of ozonation identified were formaldehyde, glyoxal, methylglyoxal, and 13 other compounds. The characteristics of the first three compounds with respect to production and decomposition during ozonation are discussed.     

Ozonation Reactions of Monomer and Dimer Lignin Models: Influence of a Catalytic Amount of a Manganese Cyclam Derivative on the Ozonation Reaction

This work focuses on the study of the reactivity of ozone with lignin models such as vanillin and dehydro-di-isoeugenol (DHDIE) in methanol solution. The primary by-products formed are characterized by Gas Chromatography - Mass Spectrometry (GC-MS) and possible mechanisms for the formation of these by-products are suggested. In the presence of a catalytic amount of a manganese tetraazamacrocyclic complex, other degradation derivatives are identified during DHDIE ozonation, proving that the complex induces a different reactivity of ozone towards the model.     

氯化消毒副产物及二氧化氯消毒剂的应用

介绍了水中微量有机污染物种类，包括饮用水中有机污染物、大分子天然有机物、氯化消毒副产物和藻类及其代谢产物。常规给水处理工艺消毒副产物及对饮用水水质影响。并介绍了二氧化氯作为消毒剂的研究现状及其消毒副产物的去除。     

Studies in autoxidation: Part II. An evaluation of the by-products formed by the autoxidation of fatty acid modified alkyd resins under the influence of different promoters

A study has been made of the by-products formed during the autoxidation of a number of drying oil modified alkyd resins when catalysed by a range of different promoters. The by-product components have been separated and identified using GC-MS methods, and their composition correlated with that of the naturally occurring fatty acids present in the individual drying oils. Mechanisms are proposed to account for the formation of the components.     

The Effect of reaction by-products on the viscosities of sodium lauryl sulfate solutions

The fact that free oil and inorganic salts have pronounced influence on lauryl sulfate solution viscosity is a widely recognized but little studied phenomenon. This investigation of the effects of these materials has resulted in the derivation of a correlation function which relates the concentrations of the by-products to the solution viscosity. The contributions of the reaction by-products are found to be independent additive effects which contribute exponentially to solution viscosity. The results can be explained mechanistically in terms of the micellar model for surfactant solutions.     

Determination and risk assessment of by-products resulting from photocatalytic oxidation of toluene

The generation of harmful by-products during photocatalytic oxidation (PCO) of volatile organic compounds (VOCs) is a bottleneck problem for the application of PCO technology in indoor environment. Toluene is a typical VOC found in indoor air. In this work, the by-products at ppb level were studied during PCO decomposition of toluene in a plate-type reactor and identified using PTR-MS (proton transfer reaction-mass spectrometry) and GC–MS (gas chromatography–mass spectroscopy). The results indicated that benzaldehyde, methanol, acetaldehyde, acetone/propionaldehyde, formic acid/ethanol and acetic acid were the main by-products in the gas phase. By adjusting the concentration of water vapor, some compounds adsorbed on the TiO₂ surface were ascertained, which resulted in the deactivation of TiO₂. They were benzoic acid, benzene, acrylaldehyde, butyraldehyde and pentanal. Some of these by-products have not been reported in the literature. Possible photocatalytic oxidation pathways of toluene were proposed. A health-related index (HRI) was introduced to assess the risk level to human health of these ppb-level by-products. It concludes that although some undesired by-products (even carcinogenic) are generated during PCO decomposition of toluene, it seems that these by-products do not have negative effects to human health because of their low concentrations.