一种浓缩液直接回用生产尼龙6切片的生产方法

为提高萃取液的利用率，采用裂解工艺，先对尼龙6聚合过程中未完全反应的低聚物和单体进行解聚，解聚后的产物直接进入反应器中，可用于高黏度有光尼龙6切片的聚合生产中。对比了优化前后的聚合工艺流程，具体介绍了纯化、浓缩、裂解、聚合、切粒、萃取、干燥等工序。采用优化工艺，既省去了复杂的蒸馏和精制工序，又节约了能源，制得的高黏度有光尼龙6切片的分子质量分布可达1.008左右。     

尼龙6/粘土纳米复合材料的研究

综述尼龙6／粘土纳米复合材料的研究进展、各种制备方法、复合机理及其微观性能的表征。粘土足一种层状硅酸盐，以纳米尺寸分布在聚合物中能提高聚合物的各种性能，尼龙6和粘土无论是通过原位聚合法还是熔融法都能制得剥离态的尼龙6倦土纳米复合材料。     

基于官能团非等活性假设的尼龙66盐溶液聚合动力学模型

尼龙66盐溶液聚合过程属于动力学控制过程。基于官能团非等活性假设，在Mallon酸催化3阶反应动力学模型基础上，引入尼龙盐脱水反应，建立了新的尼龙66盐溶液聚合反应动力学模型，拟合得到了关键反应动力学模型参数，其中盐脱水反应速率常数为8.17×10^-3 kg?mol^-1?h^-1、活化能为19859 cal?mol^-1。与Mallon模型相比，新模型拟合效果更优，可在更宽的温度和水含量范围内准确预测聚合过程的变化。模拟仿真发现，盐脱水反应对聚合过程有重要影响，低温和高水含量下尼龙盐浓度高，聚合效率低；适当提高反应温度或降低初始水含量可以加快尼龙盐脱水反应，从而提高聚合反应效率。新的尼龙盐聚合动力学建模方法不仅适用于尼龙66，也可应用于尼龙1212等盐溶液聚合体系。     

尼龙6固相聚合研究

对不同聚合方式、不同尼龙 6预聚体切片以及固相缩聚过程中缩聚副产物小分子在聚合物固体内或表面的扩散 ,在不同聚合温度和聚合时间进行了研究。结果表明 ,在本实验条件下 ,副产物小分子水在尼龙 6固体聚合物中的扩散速度是尼龙 6固相缩聚反应速度的控制步骤 ,而与气体副产物水分子在尼龙 6聚合物固体表面的扩散速度几乎无关。在相同条件下固定床固相聚合时能获得较高的数均相对分子质量尼龙 6产品。数均相对分子质量随聚合温度升高、聚合时间增加、预聚体切片粒子直径减小而增加     

基于尼龙6生产过程的聚合反应模拟优化

采用Aspen Plus模拟软件对己内酰胺水解聚合生产尼龙6工业过程进行模拟分析与优化,建立了尼龙6水解聚合生产工艺流程模型,考察了进料水含量,反应温度、前聚合管反应器压力、后聚合管反应器的真空度等影响低聚物生成的影响因素。模拟结果表明,通过降低生产工艺的反应温度、减少进料水含量、提高聚合管反应器的真空度以及降低反应器压力等方式均能有效降低聚合产品中环状聚物的含量。通过减少聚合反应过程中低聚物生成,提出了尼龙6工业生产过程中控制环状低聚物生成的工艺路线。     

尼龙6溶解于1-乙基-3-甲基咪唑溴盐的实验研究

研究了尼龙6溶解于1-乙基-3-甲基咪唑溴盐([Emim]Br),并使用去离子水作为非溶剂回收。利用红外光谱、热重及差热分析和X-射线衍射研究了再生尼龙6的结构性能,并考察了物料配比、反应温度、反应时间对尼龙6回收率的影响。结果表明:[Emim]Br能够溶解尼龙6,回收得到的尼龙6的结构和热稳定性均未发生变化,晶体类型为α型。在尼龙6与[Emim]Br的质量比为6.25%时,180℃下反应时间1.5 h,得到尼龙6最大的回收率为96.18%。     

胺类改性剂对尼龙6热氧稳定性能的影响

在己内酰胺水解聚合时加入一定量的受阻胺类改性剂，合成出含有改性剂的改性尼龙6树脂，研究了胺类改性剂对尼龙6的熔体稳定性、相对粘度、端氨基含量及机械性能在热氧作用下的改善效果。实验表明：随着胺类改性剂的加入，尼龙6熔体表观粘度随剪切速率的升高而下降的趋势变缓，熔体加工稳定性提高；与空白试样相比，改性尼龙6的端氨基含量都有不同程度的提高，高温作用下纤维的断裂强度及伸长率的变化幅度明显减小，热氧稳定性得到改善。添加0．1份改性剂后，尼龙6在热加工过程中相对粘度及端氨基含量的变化程度减小；树脂的初始热分解温度、最大热分解温度分别提高3．62℃和5．68℃。     

反应挤出己内酰胺阴离子开环聚合尼龙6的研究进展

作为一种可连续化生产,残留单体易于脱除,产物分子量高,分子量分布窄,产品性价比高的制备方法,反应挤出阴离子聚合法在尼龙6的研究中应用广泛。简要介绍了反应挤出阴离子聚合尼龙6的反应机理、工艺流程,并对国内外研究现状及发展趋势进行了分析,详细综述了反应挤出阴离子聚合尼龙6在纳米复合材料、尼龙6为基体的合金以及尼龙6为分散相的合金研究中的最新进展。     

反应挤出玻璃纤维增强尼龙6工艺初探

采用双螺杆挤出机作为聚合反应器，进行反应挤出玻璃纤维增强尼龙6的操作工艺条件探索。结果显示，加入未经处理的玻璃纤维对聚合影响较大，复合材料中的单体含量较纯反应挤出尼龙6的高，处理过的玻璃纤维与尼龙6经反应挤出后，材料的性能各项指标有明显提高。     

原位聚合制备尼龙6/纳米SiO2复合材料研究

对原位聚合制备尼龙6／纳米SiO2进行研究。结果表明，无论是否对纳米SiO2复合材料进行偶联化处理，其表面均将在原位聚合过程中与尼龙6产生接枝；SiO2表面接枝物的生成，可在某种程度上造成体系结晶程度的降低，但复合体系的力学性能主要由SiO2粒子的分散程度、粒子和其体之间的相界面性质等因素决定；采用经偶联剂处理并具有较小粒径和较大比表面积的SiO2对尼龙6进行复合，可使复合体系的力学性能指标达到较高的水平，且硅烷偶联剂的最佳用是为SiO2的3％左右。     

Entwurf und Betrieb eines Rohrreaktors mit enger Verweilzeitverteilung

In process engineering the residence time is an important design parameter, and a narrow residence time distribution is advantageous to avoid possible by-products in complex chemical reactions. A good radial mixing with low axial dispersion provides a narrow residence time distribution in a tube reactor. The axial dispersion of laminar flow in a straight tube is very high and generates a wide residence time distribution. However, secondary flows improve the radial mixing, which are investigated in this paper for curved tube reactors. Design notes for good radial mixing and geometric designs of tube reactors with baffles are presented.     

Effect of impeller type on the mixing in torus reactors

Torus reactors are characterized by a homogeneous fluid circulation without dead zones. Torus reactors were used for applications in biotechnology, food processing, polymerization and liquid waste treatments. The relatively simple extrapolation of performances, due to the absence of dead volume, is one of the main advantages of this reactor, with low shear stresses and an effective radial mixing allowing efficient heat dissipation. This study is based on the mixing in order to analyse the fluid circulation, mainly in turbulent flow regime, and to characterize the torus reactor with the axial dispersion plug flow model. The objective of this study is to characterize the flow and the mixing in the torus reactors in batch and continuous modes. The mixing analysis was made according to the flow parameters and to the geometrical characteristics of the reactor and impeller. The mixing in the torus reactor can be characterized by the Péclet number, Pe_D, defined with torus diameter. A representative model based on plug flow with axial dispersion and partial recirculation was proposed.     

Cold flow studies of a slurry transport reactor-hydrocyclon system

The fluid dynamics of a new reaction system composed of a slurry transport reactor-hydrocyclon were studied using two column diameters at different gas and liquid linear velocities. The cold models used a gas collector in the top that allowed measurement of the gas disengaged by radial zones and a conductimetric probe that measured the frequency of the bubbles exiting from the top of the reactor. Gas and liquid hold-ups were determined. Liquid and solid tracers were also employed to determine the resident time distribution (RTD), global residence time, and the recycle of slurry near the wall. The results show the effect of sparger and disengaging design, as well as the effect of gas and liquid flow rate on the radial and axial gas hold-up profiles and on the recycle of slurry by the wall. This recycle is similar to those observed with a draft tube. No significant effect of column diameter was observed. A smooth circulation of slurry and solid was achieved through a mechanical optimization of the inlet and outlet of the reactor. It was demonstrated that the RTD of the system can be simulated using a set of continuous stirred tank reactors and plug flow reactor in a recycle (three parameters). Empirical equations are proposed for predicting the hold-up and the three parameters needed by the model. The similarity to a spouted bed reactor is discussed.     

Polymerization of styrene in a continuous filled tubular reactor

Free radical solution polymerization of styrene has been studied using a binary mixture of symmetrical bifunctional initiators in a filled tubular reactor packed with static mixers. Owing to intensive radial mixing induced by the static mixers, a near plug flow pattern was obtained in the reactor with some axial dispersion effect. The axial mass dispersion coefficient was determined from the residence time distribution experiment and a dynamic axial dispersion model has been developed and solved to investigate steady state and transient behavior of the filled tubular reactor. With a solvent volume fraction of 0.3, the monomer conversion up to 70% was obtained without fouling problems in the temperature range 90 to 120°C. The experimental filled tubular reactor was operated under various reaction conditions and a reasonably good agreement between the model and the experimental data was obtained without using any adjustable parameters.     

内循环式无梯度反应器的研究

设计了一种内循环式无梯度反应器,可用以进行气固相催化反应动力学的研究。反应器的结构简单。采用电磁搅拌器以克服旋转轴径向密封的困难。催化剂可静置于多孔板上,或放在转篮中与轴一起运动。催化剂的粒度从零点几毫米至工业粒度均可适用。经停留时间分布测定证明反应器内气体的流动状况属于理想混合。径向及轴向的温度差甚小。这种反应器可以在800℃以下的温度操作。 研究了不同的气体体积流量下停留时间分布和搅拌速率间的关系。为了达到完全混合状态,较高的气体流量要求较高的搅拌速率。此外,在不同的搅拌速率下,还测定了反应器出口反应物的浓度,当搅拌速率增加至某一定数值后,组成不再改变。     

复合扰流柱的螺旋内构件反应器内流体的宏观混合

在管式反应器内插入复合扰流柱的螺旋型内构件,采用脉冲示踪法测定了反应器内流体的停留时间分布,研究了器内流体的宏观混合特性,分析了该内构件强化混合的机理. 结果表明,复合扰流柱的螺旋型内构件反应器内的流体流动更接近于活塞流,其轴向扩散模型参数Pe为螺旋型内构件反应器的1.02~1.28倍,为不带内构件反应器的1.35~1.77倍. 复合扰流柱的螺旋型内构件能显著增强器内的二次流动,从而强化了宏观混合效果.     

MICROMIXING EFFECTS ON BARIUM SULFATE PRECIPITATION IN AN MSMPR REACTOR

The Effects of non-ideal and nonhomogeneous mixing on barium sulfate precipitation in an MSMPR reactor were observed experimentally and analyzed theoretically. To generate nonhomogeneous mixing the unmixed feed streams were fed to the reactor at the same location (joint feeding mode) or a plug flow reactor was connected to the MSMPR reactor. These nonhomogeneous mixing conditions resulted in significant reductions in particle size and increases in particle numbers. These non ideal mixing effects were dependent on the impeller speed, feed stream velocity and residence time in the connected plug flow reactor and are believed to result from elevated supersaturation levels in a premixing zone which are controlled by turbulent micromixing

To model the effect of nonhomogeneous mixing (premixing) in the MSM PR reactor a plug flow-stirred lank reactor series model was developed. The plug flow reactor represents the premixing region of the MSMPR reactor in which turbulent micromixing is important, and the stirred tank reactor describes the homogeneous mixing region of the MSMPR reactor where particle growth is important. The model predicts that the premixing effect is strongly dependent on micromixing of the feeds in the premixing region, and thus, as the turbulent mixing intensity in this region is increased, the particle size in the product suspension is reduced and the particle population is increased. These predictions of the model arc in good agreement with the experimental data. An interesting prediction of the model is that as the impeller speed increases, the precipitation of barium sulfate in an MSMPR reactor deviates increasingly from the precipitation in a perfectly mixed (ideal) reactor.     

连续进出料鼓泡流化床颗粒停留时间分布

针对双流化床气化或双床热解气化工艺中鼓泡床反应器的设计,采用脉冲法研究了Geldart B类固体颗粒在连续颗粒进料和出料的矩形流化床内的停留时间分布(RTD),考察了气速、床料高度、粒径、物料流率等操作参数对RTD的影响. 结果表明,物料流率、床料高度、粒径是影响颗粒RTD的主要因素,而气速则是次要因素. 随物料流率和粒径增加,鼓泡床内颗粒流动向平推流靠近;随床料高度增加,物料在床内的混合更加充分,颗粒流动向全混流靠近. 根据实验结果,推荐采用比理想平推流时间低9%~18%计算平均颗粒停留时间.     

管式振荡流反应器的流动模式研究(Ⅰ)PIV和RTD实验研究

采用粒子成像可视化（PIV）技术研究了管式振荡流反应器（OFR）内的流场形态和混合特点,并采用脉冲进样法测定了OFR在不同振荡条件下的停留时间分布函数。实验结果表明,OFR的混合特性十分复杂,并随振荡强度的变化呈现出不同的特征。振荡强度较低时,振荡使得OFR径向混合加强,减少了滞留区,流体的流动趋于平推流;振荡强度较高时,腔室内布满数目、尺寸和位置不断变化的漩涡,使每个腔室趋向于全混,腔室问的返混增大。实验数据与多级串联全混釜模型的比较结果显示,OFR的混合特性远非简单流动模式模型所能表征。     

Characterization of the performances of an innovative heat-exchanger/reactor

The use of heat exchanger/reactors (HEX/reactors) is a promising way to overcome the barrier of poor heat transfer in batch reactors. However to reach residence time long enough to complete the chemistry, low Reynolds number has to be combined with both a plug flow behaviour and the intensification of heat and mass transfers. This work concerns the experimental approach used to characterize an innovative HEX/reactor. The pilot is made of three process plates sandwiched between five utility plates. The process stream flows in a 2 mm corrugated channel. Pressure drop and residence time distribution characterizations aim at studying the flow hydrodynamics. Identified Darcy correlations point out the transition between laminar and turbulent flow around a Reynolds number equal to 200. Moreover the flow behaves like a quasi-plug flow (Pe > 185). The heat transfer and mixing time have also been investigated. The ratio between the reaction kinetics and the mixing time is over 100 and the intensification factor ranges from 5000 to 8000 kW m⁻³ K⁻¹. As a consequence, no limitations were identified which allows the implementation of an exothermic reaction. It has been successfully performed under severe temperature and concentration conditions, batchwise unreachable. Thus, it highlights the interest of using this continuous HEX/reactor.