二硝基甲苯液相加氢催化剂研究进展

甲苯二胺(TDA)作为甲苯二异氰酸酯(TDI)的合成中间体,广泛应用于聚氨酯工业中.本综述介绍了二硝基甲苯(DNT)液相加氢制TDA催化剂在国内外的研究进展,对各类催化剂催化DNT加氢性能进行了分析,指出了各类催化剂的优缺点,提出了DNT液相加氢催化剂由晶态向非晶态方向的发展趋势.     

甲苯二胺制备技术国内外进展

从二硝基甲苯(DNT)催化加氢、甲苯二胺(TDA)分离精制、过程集成与强化等方面介绍了TDA生产技术进展,评述了我国TDA技术与国外存在的差距,指出了今后我国TDA技术应大力提高单套装置的生产规模,并利用过程技术对生产流程进行能量质量集成,以达到节能减排、安全环保、连续稳定生产的目的.     

二硝基甲苯加氢工艺研究进展

介绍了二硝基甲苯加氢反应制备二氨基甲苯的生产工艺,综述了其中加氢反应器、催化剂及温度控制等关键技术的最新研究成果,并展望了加氢工艺的发展方向。     

二甲硫基甲苯二胺

由美国Albemarle公司生产的二甲硫基甲苯二胺,主要用作两液型聚氨酯弹性体及建筑、土木行业用聚氨酯材料的氨硬化剂。目前,全球的年用量约为1000t。预计,随着美国EPA组织对二甲硫基甲苯二胺为指定物规定的解除,其需求量将大幅增加。     

2,4-二硝基甲苯无外加溶剂的加氢表观动力学

在自行设计的反应装置中以骨架镍为催化剂,在无外加溶剂的环境下催化2,4-二硝基甲苯(DNT)加氢合成2,4-甲苯二胺(TDA).考察了温度(100～140 ℃)、氢气压力(1.0～3.0 MPa)、催化剂质量浓度(0.03%～2.0%)、TDA质量浓度(30%～70%)对反应的影响.该反应的表观动力学研究表明,反应速率跟氢气压力成正比;DNT加氢反应在高浓度区(DNT浓度大于7.14 mol/m3)为吸附脱附控制,催化剂浓度与反应速率成正比,DNT浓度对反应速率无影响;而在低浓度区(DNT浓度小于7.14 mol/m3)该反应为界面反应控制;催化剂浓度在一定范围内对反应速率影响不大,DNT浓度对反应速率影响为一级.DNT低浓度区和高浓度区的活化能分别为17.62 kJ/mol和15.67 kJ/mol,表明无外加溶剂条件下催化剂可大幅降低反应活化能而使反应更易进行;在实验条件范围内TDA含量对反应速率基本无影响.并由工程数据验证了得到的该反应表观反应动力学模型的正确性     

十二碳二腈加氢制十二碳二胺催化反应的研究

通过试验,优选了十二碳二腈加氢制十二碳二胺用骨架镍催化剂。介绍了催化剂的制备方法、活化条件以及反应温度、反应压力、接触时间、搅拌速率和催化剂用量等因素对转化率的影响,研究了骨架镍催化剂的反应特性和用于十二碳二腈加氢反应的最佳操作条件。     

二甲硫基甲苯二胺

由美国Ａｌｂｅｍａｒｌｅ公司生产的二甲硫基甲基二胺,主要用作两液型聚氨酯弹性体及建筑、土木行业用聚氨酯材料的氨硬化剂。目前,全球的年用量约为１０００ｔ。预计,随着美国ＥＰＡ组合对二甲硫基甲基安为指定物规定的解除,其需求量将大幅增加。     

癸二睛加氢制癸二胺骨架镍催化剂的研究

本文介绍了癸二脯加氢制癸二胺用骨架镍催化剂的制备方法、活化条件,以及反应温度、压力、接触时间等因素对转化率的影响,揭示了骨架镍催化剂的反应特性和用于癸二脑加氮的最佳操作条件。     

二乙基甲苯二胺的合成与应用

进行了二乙基甲苯二胺的合成与应用研究。采用三乙基铝（ＴＥＡ）作为烷基化反应的催化剂，运用正交实验方法，找出了较佳的合成工艺。进行了精制研究，制得了合格产品。应用表明，合成产品与国外同类产品质量相当。     

二甲硫基甲苯二胺的合成及分析

本文讨论了交联剂二甲硫基甲苯二胺的合成方法及反应影响因素，提出了一种简便，快速的反混合物分离方法，对产品胺值进行了分析。     

二硝基甲苯氢化焦油的分析研究

采用化学分析和仪器分析研究了二硝基甲苯氢化焦油中的相关组分。结果表明,氢化焦油中间位TDA含量约为30%,固相催化剂含量3.44%,Ni含量0.437%。     

加氢还原新工艺及设备

介绍了二硝基甲苯液相加氢还原制备二氨基甲苯的生产工艺 ,催化剂采用含 0 1%～ 0 3%骨架镍的浆状催化剂 ,反应温度为 10 0℃ ,氢气压力在 15～ 2 0MPa,所得二氨基甲苯的纯度为 99%。还介绍了带复合式搅拌器的加氢反应釜、环式加氢反应器、循环反应器、卧式连续加氢反应器和三相固定床反应器。     

Catalyst preparation and support effects for triglyceride hydrogenation over supported nickel

Nickel catalysts have been prepared by impregnation and precipitation methods on silica and charcoal. Metal loadings were in the range 1–40% w/w Ni on the support. The catalysts were investigated by temperature programmed reduction (TPR) and subsequently reduced in the temperature range 200–500°C. Metal surface areas were measured via H₂ and CO chemisorption and limited studies of the catalysts were carried out using X-ray photon spectroscopy (XPS), X-ray diffraction (XRD) and transmission electron microscopy (TEM) to determine the chemical and physical state of the nickel after reduction. Reduced catalysts were employed for triglyceride (soya bean oil) hydrogenation (1 atmos H₂, 160°C) in a stirred reactor (1000 rpm) and reaction rates (catalyst activity) and product distributions were determined. Charcoal supported catalysts were active and zero valent nickel was detected after reduction. However, surface areas were variable, the performance of such catalysts being affected by pore effects, agglomeration and possibly nickel–charcoal interaction. Silica supported precipitated catalysts were of relatively high activity and metal surface if methanol washed before activation and inactive (irreducible) if only water washed. Although silica supported precipitated catalysts were more active per unit weight of metal than charcoal supported counterparts, they were less active per unit metal area and gave rise to greater trans-acid production. This may be due to triglyceride molecules excluding hydrogen from small nickel crystallites.     

Selective liquid-phase hydrogenation of 2,6-dinitrotoluene with platinum catalysts

The kinetics of the consecutive liquid-phase hydrogenation of 2,6-dinitrotoluene to 2-amino-6-nitrotoluene and 2,6-diaminotoluene was studied in ethanol with 0·5% Pt/Al₂O₃ as a catalyst using a stirred tank slurry reactor in the temperature and pressure ranges of 313 to 348 K and 0·5 to 10 MPa, respectively. The intrinsic kinetics of the consecutive reaction can be described by a Langmuir-Hinshelwood type model with non-competitive adsorption of organic species and hydrogen on the catalyst surface. At 313 K a maximum yield for the intermediate 2-amino-6-nitrotoluene of over 95% can be achieved if heat and mass transfer effects are eliminated.     

Structure and catalytic properties of Cu-Ni bimetallic catalysts for hydrogenation

The dependence of catalytic activity and selectivity of Cu-Ni bimetallic catalysts for oil hydrogenation on CuNi ratios have been investigated while they were reduced at low temperature (230 °C). Two maxima occurred at Cu₂Ni₁ and Cu₁Ni₃ in the activity-CuNi curve. Cu riched catalysts have higher selectivity than Ni riched ones, and may cause dehydrogenation and isomerization of linoleate at the beginning of the reaction. The structures of the catalysts reduced at different temperatures have been studied by means of XRD, XPS, EXAFS and FMR et al. The structure of the catalysts reduced at 230 °C can be described as an aggregate of Cu particles inlaid with Ni atoms and unreduced NiO, and the easily reduced Cu always segregates on the surface, while homogeneous solid solution particles can be formed in the case 400 °C being used as reduction temperature.     

催化裂解汽油加氢催化剂及工艺研究

根据催化裂解汽油组成特点,开发了“切C5-脱砷-切C9-两段加氢”工艺技术路线及配套的一、二段加氢催化剂.采用该工艺技术路线,利用自制催化剂对催化裂解汽油进行加氢处理,500 h稳定性评价结果表明,开发的工艺技术路线合理、可靠,催化剂性能稳定,产品溴价小于1.0 g Br/100 g,硫含量小于1.0 μg/g,满足芳烃抽提要求.     

加氢催化剂的器外再生

介绍了国内外再生技术的发展状况，对比器内和器外再生技术的优缺点以及催化剂活性恢复率的差异，说明器外再生技术是催化剂再生的发展方向。     

Novel cluster-derived catalysts for the selective hydrogenation of crotonaldehyde

The controlled pyrolysis of transition metal cluster substituted metal carboxylates, e.g., M₄O[(CO)₉Co₃CCO₂]₆, where M = Co and Zn, and M'₂(CO)₉Co₃CCOO₄, where M' = Co, Mo, and Cu, results in the formation of high surface area, amorphous solids that are active and selective catalysts for the hydrogenation of crotonaldehyde. In contrast to conventional metal catalysts that are selective for the double bond hydrogenation, these new solids exhibit high regioselectivities for the conversion of crotonaldehyde (2-butenal) to crotyl alcohol (2-butenol). Further, the observed selectivities depend on the metal cluster carboxylate structure.     

Influence of water and ammonia on hydrotreating catalysts and activity for tetralin hydrogenation

The effects of H₂O and NH₃ on the kinetics of the liquid phase hydrogenation of tetralin to decalin at 6.9 MPa and 330°C over commercial P---Ni---Mo/alumina catalysts in the presence of H₂S have been investigated. H₂O functioned as a mild kinetic inhibitor to an extent sensitive to the H₂S level. Quasi in situ XPS was used to investigate the catalyst structure after exposure to H₂0/H₂S.