清洁生产在氯化苯生产中的应用

通过在氯化苯生产中推行清洁生产,减少了生产过程中污染物的排放量,降低了原材料消耗,取得了显著的环境效益和经济效益。     

组合导向浮阀在氯化苯初、精馏中的应用

主要介绍了组合导向浮阀在氯化苯装置初、精馏塔设计中的模拟计算和优化。组合导向浮阀很好的解决了塔器放大中的滞止区增加、返混加剧、液面梯度变大等不利因素,同时还提高了塔板效率,使产品的纯度得到了进一步的改善。     

In situ production of nickel/graphitic carbon nanofiber composites and application in catalytic hydrodechlorination

The action of Ni/SiO₂ in the gas phase hydrodechlorination (at 573 K) of chlorobenzene, 1,3-dichlorobenzene and 1,3,5-trichlorobenzene is compared with that of a Ni/SiO₂ + C composite. The latter was prepared in situ by the decomposition of chlorobenzene at 873 K to generate graphitic carbon nanofibers bearing Ni particles at the fiber tips. The Ni/SiO₂ and Ni/SiO₂ + C (with varying C content) catalysts have been characterized by TEM, SEM, XRD and H₂ chemisorption. While the Ni/SiO₂ + C system delivered a lower initial fractional dechlorination, the composite outperformed the starting Ni/SiO₂ in terms of long-term activity, an effect that is linked to the structural characteristics.     

Kinetics Study of the Hydrodechlorination of Chlorobenzene Catalyzed by Immobilized Copper Complexes

The hydrodechlorination of chlorobenzene to benzene and biphenyl was studied using poly(4-vinylpyridine)-immobilized Cu catalysts under CO in basic (NaOH, N(C₂H₅)₃ or Na(CH₃CO₂)) aqueous 2-ethoxyethanol medium. This Cu system also catalyzed the water gas shift reaction. The catalytic activities for hydrodechlorination of chlorobenzene to benzene were studied as functions of the reaction parameters (nature of the base, reaction time, [Cu], P(CO), T, and S/C). Among the different base studied activity is maximum for NaOH. The rate of benzene formation displays a first-order dependence on [Cu] over the range 1.25–12.50 wt%. This observation was interpreted in terms of the presence of active species having the same nuclearity. The catalytic activity towards benzene formation proved to be first order dependence on P(CO) over the range 5–35 atm. The kinetics behavior with respect to P(CO) leads to the proposal that CO addition to the catalytic species precedes the rate-limiting step. The catalytic activity proved to be non-linear in chlorobenzene/Cu content, over the range 50–400 molar ratio. The results suggest that the rate-limiting step is preceded by reversible oxidative addition of chlorobenzene to Cu immobilized species.     

氯化苯生产中苯流失的分析与对策

分析了氯化苯生产过程中苯的流失问题,并提出了减少苯耗、降低污染的对策。     

Solid-liquid phase equilibria of (α-methylnaphthalene + β-methylnaphthalene) and (chlorobenzene + bromobenzene) systems under high Pressures

Solid-liquid phase equilibria of the (-methylnaphthalene + -methylnaphthalene) and the (chlorobenzene + bromobenzene) systems have been investigated at temperatures from 278 to 343 K and pressures up to 500 MPa using a high-pressure optical vessel. The uncertainties of the measurements of temperature, pressure, and composition were within ±0.1 K, ±0.5 MPa, and ±0.001 mole fraction, respectively. In both systems, the freezing and melting pressures at a constant composition increase almost linearly with increasing temperatures. In the former system, where the two components can form a solid solution with one another to a limit extent, the eutectic point shifts to a higher temperature and to a -methylnaphthalene-rich composition with increasing pressures. In the latter system, where the two components are completely soluble in each other in the solid phase, the freezing points of all mixtures lie between those of the pure components at each pressure. It is found that the coexistence curves obtained can be expressed by a quadratic equation in pressure.     

苯质量对氯苯生产的影响

通过对原料苯中杂质的色谱分析，发现原料苯含有噻吩、环己烷、正庚烷，甲基环己烷等杂质，论述了这些杂质对生产工艺条件及原料消耗的影响。     

正丁醇-氯苯-苯乙酮三元体系等压汽液平衡的测定与关联

正丁醇-氯苯常压下存在最低共沸现象,首先应用汽液平衡法从6种备选溶剂中筛选出苯乙酮作为最佳萃取剂,然后分别测定了正丁醇-氯苯、正丁醇-苯乙酮、氯苯-苯乙酮3个二元体系以及正丁醇-氯苯-苯乙酮三元体系在101.33 kPa下的汽液平衡数据。所有实验数据都通过了Herington法和Van Ness法的热力学一致性检验,采用Wilson、NRTL和UNIQUAC 3种活度系数模型进行关联计算,其二元拟合数据与实验数据吻合较好。使用关联得到的二元交互参数推算三元汽液平衡数据,并与实验值进行对比,偏差在合理范围以内。结果表明,苯乙酮作为萃取剂可以有效地改变正丁醇与氯苯的相对挥发度,在溶剂质量比为1：1时能够使共沸现象消失。为工业上使用萃取精馏分离正丁醇-氯苯体系提供参考,也为汽液平衡数据库补充新的内容。     

Pd/Ce基催化剂催化氧化氯苯的性能

采用等体积浸渍法制备Pd/Al₂O₃系列催化剂,考察不同Pd负载量对催化剂催化氯苯活性的影响,结果表明0.75%Pd/Al₂O₃催化剂活性最优,采用BET、H₂-TPR、SEM等对催化剂进行表征分析,表明添加Ce后氧化能力增强,催化氧化效率提高。对催化产物进行分析,使用离子色谱分析了无机Cl^-生成情况及其选择性,使用GC-MS定性分析了有机副产物,发现350℃时有少量苯生成。同时考察了焙烧温度、氯苯浓度、空速对催化活性的影响,结果表明焙烧温度过高或过低都会影响催化剂的活性,在550℃焙烧的催化剂活性更优,400℃时氯苯转化率为96%;氯苯入口处质量浓度在1500～6000mg/m³时,浓度升高,催化氯苯活性降低;空速在15000～30000h^-1时,空速对氯苯催化活性影响不大,但继续提高空速会明显降低催化活性。     

氯苯硝化工艺条件的研究

研究了影响硝化反应的主要因素，实验证明，提高硝化反应温度有利于邻位异构物的生成，增加反应时间和原料配比有利于对位异构物的生成．另外，加入磷酸和多价金属盐有利于生成邻位异构物．