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。     

4-氨基二苯胺的合成研究

采用二苯胺法,用复合骨架镍为催化剂,在中低压条件下加氢还原制备4-氨基二苯胺.文章对加氢反应进行了重点研究,考察了催化剂及其用量、温度、压力以及物料浓度对加氢反应的影响.优惠条件下的稳定性实验表明:催化剂活性稳定,加氢反应的转化率稳定在99.5%以上,4-氨基二苯胺的收率稳定在95%以上.该实验结果对开发4-氨基二苯胺新工艺具有重要意义.     

Ni/硅藻土催化2,4-二硝基甲苯加氢反应研究

以Ni/硅藻土为催化剂,研究了2,4-二硝基甲苯(2,4-DNT)在2,4-二氨基甲苯(2,4-TDA)和乙醇混合溶剂中加氢生成2,4-TDA的反应历程,考察了反应温度、反应时间和氢气压力等条件对2,4-DNT加氢的影响。结果表明,反应温度和反应时间是影响2,4-DNT加氢的主要因素,最佳反应条件为:反应温度120～130℃、氢气压力2.5～3.0MPa,反应时间140min。     

改进型LY-C_2-02催化剂模拟抚顺石化碳二加氢装置的侧线运行性能

针对抚顺石化碳二后加氢装置的特点,制备了改进型LY-C2-02催化剂,与G-58C催化剂进行对比,进行了12天的一、二段反应器串联运行的工业侧线运行试验,考察了改进型LY-C2-02催化剂的运行性能。结果表明,LY-C2-02催化剂在模拟抚顺碳二加氢装置工况情况下,在一段反应器除炔量为1.0%,高于G-58C催化剂0.04%;在二段反应器选择性为81.5%,高于G-58催化剂3.5%;综合运行性能达到G-58C催化剂水平。说明改进型LY-C2-02催化剂满足抚顺石化碳二加氢装置一、二段反应器的工艺要求,适宜应用于该装置一、二段反应器。     

渣油悬浮床加氢工艺研究

介绍了渣油悬浮床加氢技术领域的现状及抚顺石油化工研究院渣油悬浮床加氢技术特点。在不同反应器规模的连续式悬浮床加氢装置上的试验结果表明，研制的水溶性催化剂具有较强的原料适应性，在中等压力、空速约1.0 h^－1、催化剂加入量低于300 μg/g和一次通过的条件下处理常压渣油，小于500℃馏分油收率为70%～90%；处理减压渣油，小于500 ℃馏分油收率可达60%～80%，而过程甲苯不溶物质量分数低于10%。将悬浮床加氢技术与其他重油加工过程组合，可增加悬浮床加氢技术的灵活性，并有利于提高过程的总液体收率和经济性。     

2,4-二硝基甲苯加氢影响因素研究

采用负载型Ni/硅藻土催化剂,以乙醇为溶剂,用于2,4-二硝基甲苯催化加氢法合成2,4-二氨基甲苯(2,4-二氨基甲苯)的反应。考察了搅拌转速、催化剂浓度、反应温度、氢气压力和反应时间对2,4-二硝基甲苯的转化率、加氢反应的速率和副产物焦油量的影响。结果表明,反应温度、催化剂浓度和反应时间是影响2,4-二硝基甲苯加氢的主要因素,最佳反应条件为:催化剂浓度0.9%～1.4%;反应温度110～120℃;氢气压力2.2～2.8 MPa;反应时间120 min。     

3,5-二羟基苯甲酸甲酯催化加氢制备3,5-二羟基甲苯

研究了用于3,5-二羟基苯甲酸甲酯加氢反应的催化剂,得到具有良好活性和选择性的CuO-ZnO催化剂。实验结果表明：采用Cu∶Zn原子比为1∶2、还原温度为200℃的CuO-ZnO催化剂,在反应温度200℃和压力9MPa条件下,反应时间1.6h,3,5-二羟基苯甲酸甲酯的转化率为100%,3,5-二羟基甲苯的收率达到87.4%。加氢反应历程的研究结果表明,3,5-二羟基甲苯的苯环易被加氢,生成带基团的环己烷系列副产物,使其收率下降,控制反应时间是提高反应收率的一个重要因素。     

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.     

二次苯加氢工艺改进

前　言在苯加氢生产中 ,一次加氢工艺明显不如二次加氢 ,它需高温且低产量和低质量 ,而二次加氢较一次加氢又有反应温度低、质量好、产量高等优点 ,因此在工艺上改一次苯加氢为二次苯加氢。1　一次、二次加氢流程及工艺1.1　一次苯加氢一次苯加氢的氢气自换热器出来后与来自苯泵的苯在气化器处汇合气化 ,再经过热器过热至 150℃时进入列管式反应器 ,经一次反应后进入换热器和冷凝器冷凝成液体环己烷进入烷贮槽。苯加料量为50 0Ｌ/ｈ ,热点温度为 2 0 0℃ ,进反应器前的压力为0 .12 4ＭＰａ ,产品纯度为 98%。1.2　二次苯加氢二次苯加氢是苯…     

二硝基甲苯加氢制甲苯二胺催化剂的研究进展

综述了二硝基甲苯液相加氢合成甲苯二胺催化剂的研究进展,并介绍了(Pd+Pt)/C等贵金属催化剂、雷尼镍催化剂、负载型镍基催化剂、非晶态镍催化剂和漆原镍催化剂的最新研究成果。通过对比上述各催化剂在生产成本、制备工艺及催化二硝基甲苯加氢性能等方面的优缺点,发现非晶态镍催化剂不但价格低廉,而且在1 MPa低压二硝基甲苯液相加氢的反应中表现出与(Pd+Pt)/C工业催化剂相似的活性和选择性,是替代二硝基甲苯液相加氢贵金属和雷尼镍工业催化剂的首要选择;漆原镍催化剂制备工艺简单,价格低廉,且在众多的加氢反应中表现出与骨架镍催化剂相似的催化性能,也具有较大的工业化潜质。     

Diffusion effects in the hydrogenation of 3-methyl crotonaldehyde over zeolite-supported Ru

The activity and selectivity in gas-phase hydrogenation of the unsaturated aldehyde 3-methyl crotonaldehyde (UAL) over zeolite-supported Ru was found to depend markedly on the partial pressures of the two reactants in the gas phase, with the rate increasing as the ratio decreased. Anomalously low apparent activation energies were found compared to the same reaction over Ru/SiO₂, and secondary reactions to produce the totally hydrogenated product occurred much more readily in the zeolite-supported Ru. These observations led to the suggestion that these reactions were under diffusion control.     

Catalytic hydrogenation of nitrile–butadiene copolymer emulsion

Two processes have been developed for the selective hydrogenation of the CC bonds in nitrile–butadiene rubber emulsions (NBR emulsions) in the presence of a number of RuCl₂(PPh₃)₃ complex catalysts. One of the processes is carried out in a homogeneous system, in which an organic solvent, which can dissolve the NBR polymer and catalyst and which is compatible with the emulsion, is used. The other process is carried out in a heterogeneous system, in which an organic solvent which is capable of dissolving the catalyst and swelling the polymer particle but is not miscible with the aqueous emulsion phase, is used. In both processes, quantitative hydrogenation of the CC bonds of the NBR emulsion is achieved in the presence of RuCl₂(PPh₃)₃. It is also found that the addition of certain types of additives can improve the activities of the Ru-based catalysts. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 667-675, 1997     

Hydrogenation of cyclohexene and benzene over an amorphous pd-zr alloy

Amorphous Pd-Zr alloys, produced by a rapid solidification technique, were studied to determine their catalytic activity for the hydrogenation of cyclohexene and benzene. The activity of the amorphous alloy without pretreatment by air was lower than that of the corresponding crystalline alloy, but it was gradually increased with the pretreatment. The surface area and the hydrogen adsorption activity of the alloys were simultaneously increased with the pretreatment. It is found from X-ray diffraction pattern and SEM observation that palladium, which is an active species for hydrogenation in the amorphous alloys, is highly dispersed on the granulated ZrO₂ surface by the pretreatment.     

Hydrogenation of C=C and C=O groups on ruthenium-tin catalysts

The effect of addition of tin on the catalytic activity of Ru/C catalysts has been investigated in the liquid phase hydrogenation of -methylstyrene and hydrocinnamaldehyde. On increasing the Sn content, the amount of CO chemisorbed decreases, indicating a decrease in the number of Ru surface atoms. In the hydrogenation of -methylstyrene the specific activity of Ru (calculated per Ru surface atom) remains constant regardless of the Sn/Ru ratio. An increase of specific activity is however observed in the hydrogenation of hydrocinnamaldehyde. It is suggested that tin, present mainly as Sn ions, enhances the reactivity of the C=O group.     

含聚双烯烃链节聚合物的加氢

介绍了目前用于含聚双烯烃链节的聚合物加氢的催化剂的种类,讨论了SBS加氢的机理及加氢动力学的研究进展。     

我国C9加氢石油树脂研究进展

综述了我国C9加氢石油树脂的研究进展,重点介绍了C9加氢石油树脂催化剂研究、浆态加氢工艺、固定床加氢工艺及C9加氢石油树脂的应用,指出了我国C9加氢石油树脂今后的研究方向。     

Ni-Mo/γ-Al_2O_3催化剂加氢处理工艺条件的优化

采用固定床加氢装置对原料油(蜡油)进行加氢精制研究,采用控制变量法,考察了反应温度,液时空速,氢油比等对加氢效果的影响。以Ni-Mo/γ-Al_2O_3作为催化剂对加氢工艺进行优化,由数据表明升高温度、适当降低液时空速、增大氢油体积比,均有助于提高催化剂的脱硫和脱氮效果。Ni-Mo/γ-Al_2O_3催化剂在中高压条件下,反应温度为400℃,液时空速为0.25 h~(-1),氢油体积比在2 000左右时,加氢精制的效果最好。     

我国开发的几项重要加氢技术

随着原油质量变差和环保要求的日益严格,石油炼制行业面临着巨大的挑战。本文在我国炼油技术现状的同时,介绍了我国开发的几项重要加氢技术。     

Unexpected inversion of enantioselectivity during the hydrogenation of ethyl pyruvate using hydroquinine and hydroquinidine modified Pt/Al2O3

In the enantioselective hydrogenation of ethyl pyruvate using hydroquinidine 4-chlorobenzoate modified Pt/γ-Al₂O₃ catalyst, the sense of the enantioselectivity is a function of the modifier concentration. At low concentration (S)-ethyl lactate is preferred and at higher concentration (R)-ethyl lactate is formed; the opposite trend is observed with hydroquinine 4-chlorobenzoate. This is the first example where enantio-inversion is induced solely as a function of the chiral modifier concentration.     

Catalytic transfer hydrogenation of soybean oil

The catalytic transfer hydrogenation of soybean oil by various hydrogen donors and solvents with palladium-oncarbon catalyst was investigated in batch and continuous modes. The choice of reaction conditions, donor and catalyst allowed the manufacture of partially hydrogenated oils or semi-solid fats with controlled fatty acid contents, iodine value, melting point and solid content index. The level of “iso” forms of fatty acids was similar to, and average initial selectivity was higher than that obtained with gaseous hydrogenation under pressure with a catalyst of the same type. The best results were obtained in aqueous solution with sodium formate as hydrogen donor at 60°C.