环戊烯氧化反应宏观动力学模型

建立环戊烯氧化制戊二醛过程反应宏观动力学模型,并进行模型检验。结果表明,根据模型进行的模拟计算结果与实验结果符合较好,说明采用所确定的反应动力学模型及模型参数,进行环戊烯氧化反应过程的模拟计算和优化研究是可行。     

乙苯液相过氧化反应自由基动力学模型的应用研究

利用乙苯液相过氧化反应的自由基动力学模型得到的计算值和实验数据十分接近,说明该模型符合反应实际。利用该模型可以进行多段降温过程的工艺优化模拟计算,从而达到同时兼顾反应速率和选择性的目的。     

双环戊二烯解聚制环戊二烯的工程开发研究

对双环戊二烯解聚制环戊二烯的反应过程进行了热力学与动力学分析 ,建立了解聚反应器的数学模型 ,包括反应动力学模型与传递过程模型。在中试装置上对反应动力学模型进行了检验 ,模拟计算结果与中试反应器实际反应结果符合较好     

环戊烯合成环戊基甲醚的反应动力学研究

研究了甲醇与环戊烯合成环戊基甲醚(CPME)的宏观反应动力学。环戊烯与甲醇摩尔比为1∶1,温度区间为115~130℃,采用离子交换树脂催化剂,反应在固定床反应器内发生,在液相条件下得到了相应的动力学数据。结果表明,甲醇优先紧紧地吸附在催化剂的活性位上,环戊烯吸附在相同的催化剂活性位上参与反应,反应呈现明显的一级反应的特征。采用非线性曲线拟合方法处理实验数据,建立了环戊烯醚化反应动力学方程。用动力学模型求得的计算值与实验值的相对误差均在5%以内,说明所建动力学模型能较好的描述环戊烯醚化反应,具有良好的外推性。     

环戊烯合成环戊基甲醚的反应动力学研究

研究了甲醇与环戊烯合成环戊基甲醚(CPME)的宏观反应动力学。环戊烯与甲醇摩尔比为1∶1,温度区间为115¹30℃,采用离子交换树脂催化剂,反应在固定床反应器内发生,在液相条件下得到了相应的动力学数据。结果表明,甲醇优先紧紧地吸附在催化剂的活性位上,环戊烯吸附在相同的催化剂活性位上参与反应,反应呈现明显的一级反应的特征。采用非线性曲线拟合方法处理实验数据,建立了环戊烯醚化反应动力学方程。用动力学模型求得的计算值与实验值的相对误差均在5%以内,说明所建动力学模型能较好的描述环戊烯醚化反应,具有良好的外推性。     

对二甲苯二次氧化过程中液相反应的研究

通过半连续实验考察了对二甲苯(PX)二次氧化过程中的液相氧化,并对该过程进行了模拟计算。设计和进行了包含PX液相氧化、中断反应以及降温二次液相氧化三个阶段的实验;通过动力学实验测定和数据回归确定了基于芳烃氧化自由基链式反应机理的PX液相氧化动力学模型的参数;采用建立的PX液相氧化机理模型对PX分段氧化过程进行了预测。结果表明,对中断反应后的降温二次液相氧化间歇过程,采用第一阶段末期自由基浓度做初值时模型预测值与实验值符合良好;而假设自由基初值浓度为零时,PX液相氧化动力学模型对二次氧化的液相反应预测效果较差,其原因可能是中断降温后的氧化母液中存在过氧基团会使二次液相氧化反应极快地被再引发启动。     

环戊烯催化氧化合成戊二醛及其动力学

对在非水溶剂存在下过氧化氢一步催化氧化环戊烯制备戊二醛过程中的催化体系进行了研究。考察了具有脱水功能的Ｂ２Ｏ３的作用及用量，确立了具有优良催化性能的催化体系ＷＯ３－Ｂ２Ｏ３；实验测定了反应动力学数据，采用非线性回归Ｐｏｗｅｌ共扼法求得了反应动力学方程。在推荐的催化剂体系和工艺条件下，环戊烯转化率６７％，戊二醛收率６３％，选择性９１％。     

苯酚装置氧化反应器扩能改造

分析了异丙苯液相氧化反应原理及影响因素开始,通过氧化工艺技术的对比,确定了改造工艺技术;利用ASPEN PLUS模拟计算软件,引入了溶氧因子f对氧化反应理想动力学模型进行修正,确定了合理的动力学模型参数;在此基础上,对氧化反应器改造的二塔、三塔、四塔流程进行了比较,确定了最佳的改造方案.     

天然气燃烧中NOx减排的数学模型

在燃烧过程氮氧化物生成的基元反应和反应动力学基础上,推导并建立了新的NOx生成化学动力学模型,并利用流体力学计算软件及湍流模型分析手段,对天然气燃烧过程NOx生成进行了模拟计算,预测结果与实验结果吻合良好。研究表明,新模型比平衡模型和部分平衡模型预测更加接近实验结果,实现了对NOx生成数学模型的优化。     

裂解汽油中混合烯烃选择性加氢反应动力学

采用高压搅拌釜式反应器,在消除催化剂外扩散影响的基础上,对裂解汽油选择性加氢反应动力学进行了研究。以反应组分环戊二烯、苯乙烯、1-己烯与溶剂正庚烷的混合物为模型化合物,考察了反应温度和压力的影响。结果表明,环戊二烯、苯乙烯、1-己烯和环戊烯在催化剂表面为竞争加氢,双烯的反应速率远大于单烯。采用Langmuir-Hinshelwood反应机理,导出了反应动力学模型,并采用非线性最小二乘法对动力学模型参数进行估值。实验结果验证了动力学模型的合理性。     

Data mining macrokinetic approach based on ANN and its application to model industrial oxidation of p-xylene to terephthalic acid

Considering that kinetics and thermodynamics are coupled with heat and mass transfer effects being present in the liquid-phase catalytic oxidation of p-xylene to terephthalic acid (OXTA) in an industrial type of continuous stirred tank reactor (CSTR) and that the time evolution of the concentration of all the interest intermediate and final products of OXTA in the industrial CSTR cannot be obtained to estimate macrokinetic parameters, a novel data mining macrokinetic approach based on artificial neural network (ANN) was proposed to develop the macrokinetic model of OXTA in the industrial CSTR, which mines intrinsic kinetics and transport phenomena information from the sample data collected from OXTA in the industrial CSTR. Firstly, the reaction orders of OXTA are estimated by the mass transfer-free experiment data in the laboratory semi-batch stirred tank reactor. The kinetics of OXTA in the industrial CSTR is assumed to be zeroth-order with respect to gaseous reactants, 0.65-order with respect to p-xylene, and first-order with respect to the other liquid reactants, respectively. Secondly, ANN is employed to model the influence of the reaction parameters on the rate constants of OXTA in the industrial CSTR. Based on the sample data collected from OXTA in the industrial CSTR, heuristic differential evolution algorithm is employed to adjust the weights and thresholds of the rate constant ANN in such a way that it minimizes the prediction error of the macrokinetic model, and thus the optimal weights and thresholds are obtained and the macrokinetic model of OXTA in the industrial CSTR is developed. The reliability of the macrokinetic model was investigated and the satisfactory results were obtained. Further, a generalized macrokinetic approach for multi-phase reaction in industrial reactor was suggested too.     

氧在重组毕氏酵母发酵过程中的摄取与传递

引言 在生物发酵过程中,氧的供需是一个至关重要的问题[1-2].好气性微生物需要足够的溶解氧以维持自身的呼吸代谢.     

环氧乙烷非均相催化水合动力学及均温反应器热稳定性分析

采用碳纳米管增强复合材料催化剂,在等温积分反应器中获得环氧乙烷非均相催化水合宏观反应动力学实验数据,建立了幂函数型宏观反应动力学方程,采用Levenberg-Marquardt法对动力学模型参数进行估算,并以该动力学模型为基础,分析了均温反应器的热稳定性。结果表明,生成乙二醇主反应的表观活化能为71.7 k J/mol,与两个典型的串联副反应的活化能接近。模型参数统计检验结果表明,该宏观动力学方程参数是适定的,可用于工业反应器的设计。给出的反应器关键参数的计算方法,可为乙二醇合成反应器的模拟计算和设计开发提供必要的依据。     

General treatment of polymer crystallization kinetics—Part 2. The kinetics of nonisothermal crystallization

The isothermal macrokinetic equation of polymer crystallization has been generalized to cover nonisothermal situations as well. The process of nonisothermal crystallization of poly(caproamide) has been studied experimentally. It is shown that the macrokinetic equation of the autocatalytic type can be used to solve both direct and inverse problems of nonisothermal polymer crystallization. Use of the inverse approach has made it possible to establish the value of the constants of the new kinetic equation. The general statement of the problem of nonisothermal crystallization of polymers in an inhomogeneous temperature field is considered. Inhomogeneous temperature and conversion fields have been calculated for model products of different sizes and configurations.     

Kinetic behaviour of packed and fluidised bed electrodes

For the reaction of electrochemical quinone reduction at packed and fluidised bed electrodes an experimental parameter analysis of macrokinetic bed cd was carried out showing the influence of electrode potential, flow velocity, bed depth parallel to current flow direction, and electrolyte conductivity. A macrokinetic model of three-dimensional electrodes is established by introducing overpotential distribution within the electrode into the microkinetic rate equation. Theoretical calculations of macrokinetic bed cds yield reliable values as is shown by comparison with the experimental results. Both for packed and for fluidised bed electrodes analytical expressions are derived for penetration depth of diffusion limiting cd into bed electrodes.     

T305脱硫剂脱除H2S反应宏观动力学行为

用热重法研究了T305氧化锌脱硫剂脱除H₂S反应的宏观动力学。研究表明,脱硫反应动力学行为可用等效粒子模型猫迷。给出了该模型的各参数估值,分析了孔扩散、粒子内扩散及烧结对反应行为的影响。     

Adiabatic anionic polymerization of caprolactam in the presence of N-acylated caprolactam macroactivator: Kinetic study

In this study, bis ?-caprolactam bis-diphenyl methane diisocyanate polypropylene glycol 1000 used as the macroactivator was prepared and well characterized prior to use. The anionic polymerization of ?-caprolactam with the macroactivator as a function of the macroactivator concentration was adiabatically carried out. The adiabatic temperature rise method as well as the macrokinetics were used for elucidation of the kinetics of the polymerization. A nonlinear regression technique was used for determining the parameters of the macrokinetic equation. The equilibrium conversion and equilibrium time obtained were 94–96% and 2–9 min depending on the macroactivator concentration. The effects of the concentrations of macroactivator and ?-caprolactam on the initial rate, apparent overall reaction rate, and the empirical parameters were studied. A side reaction induced by the transfer of the proton in the isocyanurate group of the macroactivator to caprolactam anion was found. According to this finding, a new reaction kinetic model was proposed by properly modifying the macrokinetic equation. © 1993 John Wiley & Sons, Inc.     

乙基叔丁基醚合成反应动力学

乙基叔丁基醚一般由乙醇和异丁烯合成,以阳离子交换树脂为催化剂．研究了外扩散阻力为零时的合成反应宏观动力学模型．其本征动力学采用广义Langmuir-Hinshelwood速率方程,将反应速率用液相活度系数关联．内扩散用广义Maxwell-Stefen方程描述,以组分的化学位梯度为扩散推动力．本模型较好地描述了非理想反应物系统的吸附特性和扩散过程．用文献中的实验数据对模型作了检验.     

Passivation of Compacted Samples Made of Pyrophoric Iron Nanopowders during Their Interaction with Air

Combustion, Explosion, and Shock Waves - Various macrokinetic modes of interaction (self-ignition or combustion) of compact samples from nonpassivated (pyrophoric) and passivated iron nanopowders...