低碳烷烃制备硝基烷烃

硝基烷烃(Nitro paraffin)指低碳原子数的硝基化合物。目前市场上出现的为碳原子数小于3的伯、仲硝基化合物,硝基甲烷(Ntromethane)、硝基乙烷(Nitroethane)、1-硝基丙烷(1-Nitropropane)和2-硝基丙烷(2-Nitropropane)均为无色透明液体,具有芳香味,能与水部份互溶并形成共沸混合物。 硝基烷烃以它特有的物化性质成为药物、溶剂、表面活性剂、乳化剂和润滑剂等精细化学品领域的重要原料。硝基烷烃     

硝基甲烷的制备和应用

一、概述早期硝基甲烷是用间接方式(如氯乙酸与亚硝酸钠反应)合成的.后来有人试图用硝化芳烃的方法硝化烷烃来制备,但未成功.Hass 等人研究烷烃气相硝化的成功,才奠定了硝基低级烷烃工业生产的基     

气相硝化制备硝基烷烃

介绍了硝基烷烃气相硝化的发展历程。综述了低碳烷烃、脂肪醇、羧酸、醛和酮类均相气相硝化制备方法。并对最新的高压硝化法制备硝基烷烃进行了简介。随着气相硝化技术的不断发展,硝基烷烃将得到更为广泛的应用。     

硝基乙烷生产中乙基硫酸钠的回收利用

１前言硝基乙烷可用作硝酸纤维素、醋酸纤维素、树脂、蜡、脂肪和染料等的溶剂和火箭的燃料,也可用于合成农药、医药等重要化合物。硝基乙烷的合成方法主要有乙烷硝化法、氯乙烷硝化法和硫酸二乙酯硝化法。前二者均需在加压条件下进行反应,反应条件复杂,不易控制。硫酸...     

甲烷/乙烷与甲烷/丙烷混合燃料着火特性

利用激波管与CHEMKIN软件研究了不同初始条件下乙烷和丙烷的掺混对甲烷着火延迟时间的影响规律,并从化学动力学角度分析了掺混乙烷和丙烷对甲烷着火延迟时间造成影响的原因。实验与模拟研究表明乙烷和丙烷的掺混会造成甲烷着火延迟时间的大幅度缩短,但随着温度的升高,其对甲烷着火延迟时间的影响逐渐变小。通过敏感性分析发现无论是甲烷/乙烷混合燃料还是甲烷/丙烷混合燃料,对着火促进最大的基元反应都是H+O_2=O+OH(R1),在甲烷/乙烷和甲烷/丙烷混合燃料的着火反应中对着火抑制最大的两个基元反应是CH_4+H=CH_3+H_2(R128)和CH_4+OH=CH_3+H_2O(R129)。通过路径分析发现在甲烷/乙烷与甲烷/丙烷混合燃料中,随着混合燃料中乙烷与丙烷比例的增加,甲烷的主要反应路径基本不发生变化,主要影响了CH_3的消耗速率。     

2-硝基丙烷合成工艺进展

本文概述了2-硝基丙烷的用途及常见合成路线,包括亚硝酸盐置换法、直接硝化法、双氧水氧化丙酮法及肟氧化法。重点介绍了这四条合成路线的合成进展、反应原理、工艺条件和生产技术现状。最后对2-硝基丙烷未来在我国的发展进行了展望。     

化工专利

连续三塔顺序精馏分离硝基甲烷－硝基乙烷－硝基丙烷的方法 公开（公告）号：CN102229535A 公开（公告）日：2011．11．02     

化学系统公司评述利用烷烃的新技术

据英国化学系统咨询公司的一份题为“烷烃活化：将来的石化原料”的报告，目前正在开发的甲烷或乙烷氧化制醋酸、丁烷氧化制甲基丙烯酸甲酯（ＭＭＡ）等生产工艺吸引着技术和工业化开发的兴趣。这些技术路线使用新催化剂与低价格的Ｃ１～４烷烃原料配合，有可能使产品的可变成本比传统技术生产的产品低３８０美元／ｔ。从７５种用甲烷、乙烷、丙烷和丁烷为原料制造的有发展前途的产品和有关技术中，化学系统公司选出了１１种最有前途的技术践线，其中包括乙烷氯氧化制氯乙烯单体，丙烷氨氧化制丙烯腈。新技术中包括加拿大天然资源公司正在以…     

甲烷/乙烷与甲烷/丙烷混合燃料着火特性

利用激波管与CHEMKIN软件研究了不同初始条件下乙烷和丙烷的掺混对甲烷着火延迟时间的影响规律,并从化学动力学角度分析了掺混乙烷和丙烷对甲烷着火延迟时间造成影响的原因。实验与模拟研究表明乙烷和丙烷的掺混会造成甲烷着火延迟时间的大幅度缩短,但随着温度的升高,其对甲烷着火延迟时间的影响逐渐变小。通过敏感性分析发现无论是甲烷/乙烷混合燃料还是甲烷/丙烷混合燃料,对着火促进最大的基元反应都是H+O₂=O+OH（R1）,在甲烷/乙烷和甲烷/丙烷混合燃料的着火反应中对着火抑制最大的两个基元反应是CH₄+H=CH₃+H₂（R128）和CH₄+OH=CH₃+H₂O（R129）。通过路径分析发现在甲烷/乙烷与甲烷/丙烷混合燃料中,随着混合燃料中乙烷与丙烷比例的增加,甲烷的主要反应路径基本不发生变化,主要影响了CH₃的消耗速率。     

以烷烃做石化原料的新工艺路线

在化学系统公司的名为《烷烃作为未来石化原料的活力》的报告中指出,正在开发的新工艺路线,如甲烷或乙烷氧化生成醋酸、丁烷氧化生成ＭＭＡ,非常具有技术和商业吸引力。与传统技术相比,这些工艺路线将低成本的Ｃ１～Ｃ４烷烃进料与新型催化剂相结合,可能会节约可变成本达３８０美元／ｔ。在以甲烷、乙烷、丙烷和丁烷为原料的７５种较有前景的产品和技术中,化学系统公司列示出最有前景的１１种工艺路线,包括最先进的和已公开的工艺,如乙烷氧氯化制ＶＣＭ、丙烷氨氧化制丙烯腈。新兴工艺有加拿大自然资源公司正在开发和中试的甲烷氧化…     

A theoretical explanation of solvent effects in zeolite catalysis

In a previous study of solid acid catalysis (Nature (1998) 389, 832) we showed that the catalytic activity of zeolites could be increased by the coadsorption of “solvent” molecules, such as nitromethane. These coadsorbates do not participate directly in the reaction, but alter the environment within the zeolite such that reactivity is increased. In this work we provide further theoretical explanation of the increased reactivity observed upon coadsorption. We first use density functional theory (DFT) to study the proton affinity of acetone, and complexes of acetone with propane, bromomethane, nitromethane, nitroethane, nitropropane, and acetonitrile. We find that the proton affinity of acetone in the complexes is much higher than for acetone alone. Optimizations and frequency calculations at the B3LYP/6–311++G** level predict proton affinity increases that range from 0.9 kcal/mol for the acetone/propane complex to 12.8 kcal/mol for the acetone/acetonitrile complex. The increase in proton affinity due to the coadsorbed molecules is one of the causes of the increased reactivity observed experimentally. We also used DFT (B3LYP/DZVP2) to optimize the geometry of acetone and the acetone–nitromethane complex in contact with a cluster model of HZSM-5. There is greater proton transfer from the zeolite to acetone when nitromethane is present, as is reflected in the shorter distance between the acidic zeolite proton and the carbonyl carbon of acetone. Predictions of ¹H and ¹³C NMR isotropic chemical shifts also indicate increased proton transfer to acetone in the presence of nitromethane. This further demonstrates how coadsorbates promote reactivity. This revised version was published online in June 2006 with corrections to the Cover Date.     

Role of organic nitro compounds in selective reduction of NOx with ethanol over different supported silver catalysts

The adsorption of organic nitro compounds such as nitromethane and nitroethane on different supported silver catalysts (Ag/Al₂O₃, Ag/TiO₂, Ag/SiO₂) has been studied using infrared spectroscopy. The adsorbed NCO species formation was strongly influenced by the catalyst support and therefore clearly detected on Ag/Al₂O₃ and Ag/TiO₂ catalysts by thermal decomposition of nitromethane and nitroethane at temperatures higher than 150°C. With the Ag/SiO₂ catalyst, very little NCO formation was observed at 350°C. On the other hand, the catalyst support was found to affect the N₂ formation in the selective reduction of NO_x on supported silver catalysts. On the basis of these findings, the role of adsorbed nitromethane, nitroethane and isocyanate species in the selective reduction of NO_x is discussed with respect to the catalyst support effect and the catalytic activity. This revised version was published online in July 2006 with corrections to the Cover Date.     

关于硝基氯苯生产中氯苯硝化的几点体会

理论与实践相结合探讨了影响氯苯硝化反应的因素,包括硝化剂、温度、搅拌、硝酸比,总结出氯苯硝化反应过程的工艺条件为：（１）混酸中各组分的质量分数为硫酸５５％、硝酸３６％、水９％;（２）硝化温度５５℃;（３）搅拌速度３００ｒ／ｍｉｎ;（４）反应后物料中硝酸过剩量１％～５％。并介绍了硝化工序中工艺设计和生产操作中的一些经验。     

多维气相色谱法测定汽油中硝基化合物含量

本文论述了利用气相色谱法检测添加了燃油清净助燃MAZ剂的汽油中有效成分含量的方法,MAZ剂有效成分主要是硝基甲烷、硝基乙烷和硝基丙烷三种硝基化合物,其加入量直接影响发动机的除碳和喷油与引擎内部组件保护效果,因此测定汽油中硝基化合物含量是非常重要的,本文提出的方法测定范围为0.1～0.6 mg/mL,分析时间为23 min内,重复测定结果的相对标准偏差(RSD)小于6.5%,标准加入回收率在90～120%范围,方法准确可靠。     

Copper Complex of Aminoisoborneol Schiff Base Cu2(SBAIB‐d)2: An Efficient Catalyst for Direct Catalytic Asymmetric Nitroaldol (Henry) Reaction

A new bifunctional copper complex of the aminoisoborneol Schiff base – Cu₂(SBAIB‐d)₂ – has been developed for the effective direct catalytic asymmetric Henry reaction. One mol% of this catalyst produces the expected Henry products in high yields (up to 99%) with excellent enantioselectivities (up to 98% ee). The utility of the present catalyst was also extended to the Henry reaction with nitroethane and 1‐nitropropane that furnished the corresponding products in moderate to high yields (up to 99%) with moderate to high enantioselectivities of syn (up to 98% ee) and anti (up to 98% ee) diastereomers. The highlights of this catalytic system are easy manipulation, air and moisture tolerance, the need for 1 mol% of an easily synthesizable catalyst and the high enantioselectivities achieved for a wide range of substrates.     

硝基苯清洁生产催化剂及工艺的研究

从硝化剂、催化剂和工艺等方面阐述了用于清洁生产硝基苯的方法。讨论各种固体酸催化剂对苯硝化的催化活性、反应温度、苯与硝化剂物质的量比等工艺条件对硝基苯基本收率的影响。     

Thermal properties of cellulose triacetate as prepared from low-grade dissolving pulp

Because cellulose triacetate is prepared from low-grade dissolving pulp, a considerable amount of the insoluble residue was present in the acetylation medium of the acetic acid/acetic anhydride/sulfuric acid system. To reduce the insoluble residues, a solvent, such as nitromethane, nitroethane, or dichloroacetic acid, added to the acetylation medium was found to be very effective for its reduction. By exploring the optimum conditions for acetylation with these solvents, nitromethane added and dichloroacetic acid added systems with solvent/acetic acid = 3/7 (v/v) were found to have a particularly high transmittance at λ = 670 nm in their acetylation solution with a low insoluble residue. The obtained acetates revealed good thermal properties similar to that from high-grade dissolving pulps. Therefore, a high quality cellulose triacetate can be manufactured from acetylation systems with even low-grade dissolving pulps with an appropriate solvent added. © 1996 John Wiley & Sons, Inc.     

丙烷丙烯分离塔操作优化研究

介绍了丙烯的生产工艺方法,利用化工软件的模拟计算结合实际生产标定探索丙烷丙烯分离塔的操作优化,并分析了丙烷丙烯分离塔生产波动的原因,提出了操作优化方案。     

High Pressure Raman Spectroscopic Study of the Effects of n‐Ethylamines and Water on the 2‐Nitropropane/Nitric Acid System

High pressure Raman spectroscopy measurements in a diamond anvil cell (0–10 GPa) on 2‐nitropropane/nitric acid/X (X=triethylamine, diethylamine, and water) ternary systems and 2‐nitropropane/nitric acid/water/Y (Y=triethylamine and diethylamine) quaternary systems are reported. The modifications of the chemical behavior of the 2‐nitropropane/nitric acid model system, induced by the presence of triethylamine, diethylamine, and/or water, were studied at ambient and high pressure. At ambient pressure, the ionization of the nitric acid has been observed with each of the additives. Moreover, in the case of ethylamines, new peaks have been observed and the hypothesis of a 2‐nitropropane/ethylamine complex is advanced. At high pressure, the decomposition of the 2‐nitropropane/nitric acid system, with an oxygen balance near zero, has been observed only in presence of triethylamine. The role of each additive to the 2‐nitropropane/nitric acid system in the modification of the respective reducing and oxidizing character of the components, and in the reactivity of the system, is discussed. Several hypotheses are advanced concerning the sensitizing effect of the additives on the 2‐nitropropane/nitric acid system.     

硝基甲烷与氨基及羟基化合物间的相互作用

利用密度泛函理论方法,在B3LYP/6-311++G**水平下研究了硝基甲烷与乙二胺、乙二醇、1,1-二氨基丙烷和1,1,3-丙三醇的相互作用。通过基组重叠误差和零点能校正,得到它们的相互作用能。结果表明,硝基甲烷与1,1,3-丙三醇的相互作用能为-19.90kJ/mol;含有多羟基的化合物可增加硝基化合物的热稳定性。通过热重分析方法检测添加1,1,3-丙三醇前后硝基甲烷的完全失重温度,发现添加微量1,1,3-丙三醇可明显提高硝基甲烷的完全失重温度和热稳定性。计算结果与实验数据吻合。