氢氟酸改性USY分子筛催化合成ETBE反应本征动力学

以乙醇和叔丁醇为原料、氢氟酸改性USY分子筛为催化剂合成乙基叔丁基醚，建立了反应动力学模型。反应过程在钢密封间歇反应釜中进行，且消除了内、外扩散的影响。改变原料浓度和反应温度得到醚化反应本征动力学实验数据。实际动力学线性回归方程约为is_r=k_c^1.5A_c^-0．5B，频率因子A=1.4×10⁸h^-1，反应活化能Ea=72.51 kJ·mol^-1。依据L-H和R-E机理推导出的模型方程约为is_r=k_c^1.5A_c^-0．5B，频率因子A′=1.3×10⁸h^-1，活化能Ea=70.47 kJ·mol^-1。因此，可近似认为表面反应是反应的速率控制步骤。     

苯与长链烯烃在HPWA/SBA-15催化剂上的本征反应动力学研究

采用HPWA/SBA-15催化剂对苯与长链烯烃的烷基化反应过程进行了研究。反应过程在固定床反应器中进行,且消除了内外扩散的影响。在反应压力2.0 MPa,原料苯烯摩尔比10∶1的条件下,改变反应温度和质量空速得到了烷基化反应本征动力学实验数据。实际动力学方程计算线形回归约为r=kcA,频率因子k0=2.35×1019h-1,反应活化能Ea=153.93 kJ/mol。依据L-H和R-E机理推导出的模型方程约为r=k′cA,频率因子k0′=1.08×1019h-1,活化能Ea=151.39 kJ/mol。因此,可近似认为表面反应是反应的速率控制步骤。     

HY分子筛催化合成油酸乙酯

采用NaY分子筛催化剂,经离子交换和高温焙烧制得HY分子筛,以油酸和乙醇为原料,在间歇反应釜进行酯化反应研究。考察反应温度、原料配比、催化剂用量和反应时间等条件对酯化反应的影响。结果表明,在反应温度180 ℃、n(油酸)∶n(乙醇)＝1∶2.5、催化剂用量为原料总质量的1.0%和反应时间4 h条件下,油酸转化率可达81.18%。实验中的HY分子筛表现出较高的活性和良好的稳定性。     

阳离子交换树脂催化合成乙酸正丁酯的动力学

在间歇反应釜中,以A-36阳离子交换树脂作催化剂,考察了搅拌速率、催化剂粒径、温度、催化剂浓度和酸醇比对乙酸正丁酯合成的影响,并采用LHHW动力学模型对实验数据进行处理.结果表明,表面反应为乙酸和正丁醇酯化反应的控制步骤,其反应焙为-1.838×104 J/mol,正反应与逆反应的活化能分别为5.283×104J/mol和3.929×104J/mol,指前因子分别为1.015×104 mol/(g·s)和3.148 mol/(g·s).     

顺酐加氢制备丁二酸的动力学研究

在等温积分固定床反应器及自制催化剂上,对顺酐加氢生成丁二酸的反应动力学进行了研究,得到该反应的活化能Ea为63.13 kJ/mol,指前因子A为1.98×106L.mol-1.h-1,反应的动力学方程为:r=1.98×106×exp(-63130/RT)×CMA。     

甲醇和异丁烯在HBT6分子筛上的反应机理

研究了甲醇、异丁烯和甲基叔丁基醚 (MTBE)在HBT6分子筛上的吸附 ,探讨了HBT6分子筛催化剂上合成MTBE反应的机理 ,并结合本征动力学实验结果 ,提出了反应的机理动力学模型 .结果表明 ,甲醇、异丁烯、MTBE均吸附在催化剂的酸性OH基上 ,其中异丁烯主要以π络合形式吸附 ,这种吸附态容易转变为叔丁基正碳离子 .甲醇与异丁烯在HBT6分子筛催化剂上的醚化反应按照L -H机理进行 ,表面反应为速度控制步骤     

硫酸氢钠催化合成乙酸乙酯动力学研究

在间歇反应釜中以硫酸氢钠为催化剂,乙醇和乙酸为原料催化合成乙酸乙酯。在消除内外扩散影响的前提下,以初始速率法回归动力学方程。在催化剂过200目分子筛,实验转速为200 r/min条件下,反应内外扩散可以消除。在实验范围内获得动力学方程参数为:活化能33609.35 J.mol-1,指前因子k0=24874.29 mol-1.L·min-1,反应动力学方程为:-rA=(0.0657x-0.00746)×2487.29×e-33609.35/RT×(CACB-CECW/3.51)。     

HPWA/SBA-15催化合成对叔丁基苯酚

以SBA-15负载磷钨酸（HPWA）为催化剂、甲基叔丁基醚（MTBE）和苯酚为原料在钢密封间歇反应釜中进行催化合成对叔丁基苯酚的实验研究。考察了HPWA负载量、催化剂用量、反应温度、反应时间及原料配比对烷基化反应的影响。实验结果表明,反应温度为160 ℃、负载HPWA质量分数30%、反应时间3 h、催化剂用量为原料质量的5%和原料配比n(MTBE)∶n(苯酚)＝2∶1时,苯酚的转化率为85.1%, 对叔丁基苯酚的选择性66.87%。实验中HPWA/SBA-15分子筛表现出较高的活性及选择性。     

HY型分子筛负载Pd催化剂用于乙炔氢氯化反应制氯乙烯的催化性能

以水热法合成HY分子筛为载体,等体积浸渍法制备HY型分子筛负载Pd催化剂(Pd/HY)。在反应温度160℃、空速120 h-1和V(HCl)∶V(C2H2)=1.1∶1条件下,考察催化剂用于乙炔氢氯化反应制氯乙烯的催化性能及载体中硅铝比对催化剂催化性能的影响。用XRD、FI-IR、SEM和BET对Pd/HY催化剂的物化性质进行表征,结果表明,Pd/HY(HY分子筛的Si/Al=8)催化剂表现出较好的催化活性,乙炔转化率为97.67%,氯乙烯选择性为98.44%。与工业HY型分子筛为载体的催化剂相比,乙炔转化率提高29%,寿命较长,稳定性良好。     

新型负载磷钨杂多酸的轻汽油醚化性能

用球磨共混法制备了磷钨杂多酸负载于HY、Hβ和HZSM-5上的双组元催化剂,分别考察了磷钨杂多酸(HPWA)、HY、Hβ和HZSM-5单组元催化剂及其HPWA与分子筛负载的双组元催化剂对轻汽油与甲醇醚化的反应性能。在自生压力反应釜进行反应的实验结果表明,负载质量分数40％HPWA的HPWA/Hβ具有优良的反应性能。对40％HPWA/Hβ催化剂进行反应条件优化实验结果表明,该催化剂的最优反应条件为：剂油质量比1∶12,反应温度90 ℃,醇油质量比1∶3,甲醇含水量4％,反应时间2 h。在此条件下,烯烃转化率55.78％,醚化选择性64.00％,醚收率35.69％。     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

几种乙炔加压设备性能的比较

阐述并比较了几种加压设备在乙炔加压清净过程中的性能和特点。     

三种煤样燃烧热的测定

本文通过三个厂家提供的三种煤样燃烧热的测定,由测定结果综合得出3号煤样燃烧最完全、燃烧热也最大,是三个煤样中最好的一种。     

Semi-empirical equation of state of metals. Equation of state of aluminum

A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO₂) of density 0.08 g/cm³. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008.     

小议汽车涂装工艺设计对涂装成本的影响

论述了涂装工艺设计对涂装设备投资、涂装生产成本的影响。     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

Measurement of the gradient of viscosity with composition of mixtures of non-ideal gases

A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%.     

Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone

A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out.     

塔设备改造选型的分析

就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后，着重介绍一种新型塔板（导向梯形浮阀塔板）和一种新型填料（波环填料——乾隆帕克）。     

Effect of degree of deacetylation of chitin on the properties of chitin crystallites

In the present article, chitin from crab shell was systematically deacetylated using a NaOH treatment with control of the reaction time. The degree of deacetylation, monitored using solid-state NMR, revealed that the reaction was pseudo-first order. Based on this, swollen and NaOH-saturated particles are proposed as the reaction system. The weight loss of the partially saponified and neutralized samples after HCl hydrolysis increased linearly with the degree of deacetylation. The crystallinity of the samples was found to increase after acid hydrolysis. According to conductimetric titration, the surface charge density of the crystallites, after acid hydrolysis, was found to increase with base treatment time. The effect of surface charge on the formation of a chiral nematic phase, due to the rodlike nature of the crystallites, was explored. These results show that because the contribution of charged particles to the ionic strength was significant the double layer compression was affected, especially since the surface charge density was close to the Manning limit. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:373–380, 1997