工业PTA溶剂脱水过程动态模拟与分析

Dynamic model for dehydration process of industrial purified terephthalic acid solvent is investigated to understand and characterize the process.A temperature differential expression is presented,which ensures the equation to convergence and short computation time.The model is used to study the dynamic behavior of an azeotropic distillation column separating acetic acid and water using n-butyl acetate as the entrainer.Responses of the column to feed flow and aqueous reflux flow are simulated.The movement of temperature front is also simulated.The comparison between simulation and industrial values shows that the model and algorithm are effective.On the basis of simulation and analysis,control strategy,online optimization and so on can be implemented effectively in dehydration process of purified terephthalic acid solvent.     

基于自联想递阶神经网络的多输入参数化工过程软传感器(英文)

To explore the problems of monitoring chemical processes with large numbers of input parameters, a method based on Auto-associative Hierarchical Neural Network (AHNN) is proposed. AHNN focuses on dealing with datasets in high-dimension. AHNNs consist of two parts:groups of subnets based on well trained Auto-associative Neural Networks (AANNs) and a main net. The subnets play an important role on the performance of AHNN. A simple but effective method of designing the subnets is developed in this paper. In this method, the subnets are designed according to the classification of the data attributes. For getting the classification, an effective method called Extension Data Attributes Classification (EDAC) is adopted. Soft sensor using AHNN based on EDAC (EDAC-AHNN) is introduced. As a case study, the production data of Purified Terephthalic Acid (PTA) solvent system are selected to examine the proposed model. The results of the EDAC-AHNN model are compared with the experimental data extracted from the literature, which shows the efficiency of the proposed model.     

基于粒子群优化算法的水分配网络系统综合的最优化研究

The problem of optimal synthesis of an integrated water system is addressed in this study, where water using processes and water treatment operations are combined into a single network such that the total cost of fresh water and wastewater treatment is globally minimized. A superstructure that incorporates all feasible design alterna- tives for wastewater treatment, reuse and recycle, is synthesized with a non-linear programming model. An evolutionary approach--an improved particle swarm optimization is proposed for optimizing such systems. Two simple examples are .Presented.to illustrate the global op.timization of inte.grated water networks using the proposed algorithm.     

用基团贡献+神经网络+颗粒群优化相结合的方法来预测有机化合物的闪点温度

The flash points of organic compounds were estimated using a hybrid method that includes a simple group contribution method (GCM) implemented in an artificial neural network (ANN) with particle swarm optimization (PSO). Different topologies of a multilayer neural network were studied and the optimum architecture was determined. Property data of 350 compounds were used for training the network. To discriminate different substances the molecular structures defined by the concept of the classical group con-tribution method were given as input variables. The capabilities of the network were tested with 155 substances not considered in the training step. The study shows that the proposed GCM+ANN+PSO method represent an excellent alternative for the estimation of flash points of organic compounds with acceptable accuracy (AARD 1.8%; AAE 6.2 K).     

采用极性及非极性溶剂从酸洗后的红法夫酵母中高效萃提虾青素的研究(英文)

method of extracting astaxanthin from Phaffia rhodozyma with various solvents after acid washing was investigated.The extraction efficiency was distinctly increased after acid washing of P.rhodozyma cells.When the concentration of HCl was 0.4 mol·L-1,the highest extraction efficiency of astaxanthin was achieved which was about three times higher than the control.Acetone or benzene as single polar or non-polar solvent was the most effective solvent in our research.With a combination of isopropanol and n-hexane(volume ratio of 2:1),the maximal extraction efficiency was achieved,approximately 60% higher than that obtained with a single solvent.The liquid-solid ratio and the extracting time were also optimized.Under the optimum extraction conditions,the extraction yield of astaxanthin exceeded 98%.     

基于复合神经网络的离散非线性系统建模与控制

An adaptive inverse controller for nonliear discrete-time system is proposed in this paper. A compound neural network is constructed to identify the nonlinear system, which includes a linear part to approximate the nonlinear system and a recurrent neural network to minimize the difference between the linear model and the real nonlinear system. Because the current control input is not included in the input vector of recurrent neural network (RNN), the inverse control law can be calculated directly. This scheme can be used in real-time nonlinear single-input single-output (SISO) and multi-input multi-output (MIMO) system control with less computation work. Simulation studies have shown that this scheme is simple and affects good control accuracy and robustness.     

降低腈纶溶剂NaSCN系统含杂的研究

针对超滤技术在腈纶溶剂二步法硫氰酸钠系统应用中存在的问题开展试验研究,主要考察了不同类型超滤膜(内、外压膜差异以及膜丝固定形式差异)的投用效果、产料反冲洗及进料方式对膜运行周期的影响等。通过试验可知:投用超滤膜对二步法料液中水不溶物有一定的去除效果;采用新型超滤膜(膜丝一端固定),其过滤周期是传统两端固定超滤膜的2.5倍;内压式超滤膜不适用于处理二步法硫氰酸钠料液;增加产料反冲洗能显著提高过滤时间、过滤总流量。经过优化,基本解决了存在的膜通量无法恢复、过滤时间短、通量衰减过快等问题,为产业化改造提供依据。     

溶剂浮选法回收湿法磷酸中碘的研究

溶剂浮选法回收湿法磷酸中的碘是一种新工艺.采用二次回归旋转实验设计方法组织实验,对实验数据处理得到的预测回归方程在实验范围内可以较好地预测各因素在不同条件下对碘回收率的影响.结果表明,影响碘回收率的最重要的因素是浮选时间、溶剂量和氧化时间.以碘回收率为指标,得出溶剂浮选法回收湿法磷酸中碘的最佳工艺条件(固定条件:湿法磷酸用量50 mL,N2流速40 mL/min):捕收剂CTMAB用量0.065 g、溶剂苯用量12 mL、氧化时间18 min、浮选时间25 min.     

精对苯二甲酸(PTA)结晶动力学

建立了精对苯二甲酸连续多级降压蒸发结晶过程的数学模型,通过工业实验获得了各级结晶器不同操作条件下的产品粒度分布数据,并构造了模型计算值和工业实验值相拟合的优化目标函数,采用单纯形法优化回归得到了精对苯二甲酸结晶动力学参数。研究结果表明,优化回归得到的精对苯二甲酸结晶动力学方程能够较好地模拟PTA连续多级降压蒸发结晶过程。     

精对苯二甲酸项目的节能评估及建议

介绍了固定资产投资项目的节能评估依据;以1 200 kt/a精对苯二甲酸(PTA)项目为例,分析了项目用能情况,比较了能耗计算方法 GB/T 2589—2008和GB/T 50441—2007标准的差异;对1 200 kt/a PTA项目进行了节能评估并提出建议。经评估,1 200 kt/a PTA项目装置综合能耗为5.18 GJ/t,低于限额规定值,项目技术先进;PTA项目节能评估需要分别对生产装置和全厂综合能耗进行测算,通常全厂综合能耗大于装置综合能耗;对不同PTA装置进行能耗对比时,宜采用GB/T 50441—2007,与宏观经济相关的能耗计算,宜采用GB/T 2589—2008。     

精对苯二甲酸产品和方法标准的研究进展

精对苯二甲酸（PTA）是一种重要的化工原料,主要用于生产聚对苯二甲酸乙二醇酯（PET）及后续产品,如纤维、瓶片、薄膜以及工程塑料,其质量品质和标准对下游聚酯产品稳定生产和性能具有重要影响,受到行业越来越多的关注。本文概述了国内工业用PTA技术标准的发展历程,介绍了PTA行业标准的现状、主要技术内容以及存在的问题,重点解析了PTA国家标准包括1项产品标准、7项配套方法标准的研究背景,与行业标准相比所作的重要技术调整和技术水平的提升;介绍了PTA国际标准化研究的进展,特别是近年来由中国石化主导制定的7项PTA系列ASTM标准取得的突破性成果;在此基础上,对未来PTA标准技术的研究进行了思考,提出了加强微量杂质控制、关注影响高端聚酯产品质量控制指标等建议。     

高温下对苯二甲酸在醋酸-水溶液中的溶解度预测

在醋酸摩尔分数0.73,温度130～270℃的范围内利用UNIFAC模型估算了对苯二甲酸在醋酸 水溶液中的溶解度,估算值与文献值的平均相对误差7.74%,表明本文所建方法在缺乏实验数据的情况下可以用来预测高温下TA在醋酸 水溶液中的溶解度。因此,用该方法预测了130～270℃范围内60%～90%醋酸 水溶液中的TA的溶解度,给出了不同组成下的溶解度 温度图。     

对苯二甲酸和对羧基苯甲醛在醋酸水溶液中的溶解度

测定了420-505K温度范围内,对苯二甲酸和对羧基苯甲醛在醋酸水溶液中溶解度。在70%-100%醋酸水溶液中,70%醋酸使对苯二甲酸的溶解度对温度最敏感,随着醋酸浓度增加,对苯二甲酸的溶解度减少。当温度低于470K时,对苯二甲酸在水中的溶解性低于醋酸中的溶解度;温度高于470K时,对苯二甲酸在水中的溶解性对温度敏感明显提高。40%醋酸使对羧基苯甲醛的溶解度对温度最敏感, 随着醋酸浓度增加, 对羧基苯甲醛的溶解度增加。实验数据用修正的Apelblat方程进行了对苯二甲酸和对羧基苯甲醛在醋酸水溶液中溶解度关联,计算与实验值吻合良好。     

精对苯二甲酸氧化反应器中气体停留时间分布

对苯二甲酸的工业生产多采用对二甲苯液相催化氧化方法,因此,氧化气体的混合特性就成为氧化反应器设计、放大的重要参数。文中针对工业中采用的涡轮桨和斜叶桨组合搅拌反应器型式,以氢气为示踪剂,采用阶跃激发响应技术测定了不同气量、搅拌转速下气体停留时间分布,同时开展了对二甲苯氧化试验,了解了气体混合对氧化中间产物含量影响。研究结果表明,只有当搅拌桨叶尖速度高于一个临界值,使气体接近全混的状态,才能实现单釜氧化目的产物的高收率。     

优化TA工艺 降低醋酸单耗

结合PTA生产技术的发展 ,抓住影响醋酸消耗高的主要因素 ,展开技术攻关。通过减少氧化反应器跳车次数、对氧化反应实施降温降压、工艺运行参数调优和优化日常作业提高溶剂回收率等 ,达到降低酸耗的目的     

PTA装置降低乙酸单耗的方法

通过对PTA生产工艺现状的研究,确定了造成乙酸损失的几个主要因素。提出了有效降低乙酸单耗的几点措施:(1)将氧化反应器的温度控制在195℃以下;(2)将溶剂脱水塔塔顶温度控制在85℃以下;(3)将残渣蒸发器筒体内压力控制在6.8～7.4 MPa,锥部压力不低于1.2 MPa;(4)将母液中的Na+质量分数控制在100×10-6以下;(5)高压吸收塔塔顶喷淋水流量控制在3.4 t/h;(6)升高第一结晶器的压力。     

精对苯二甲酸的灰分测量结果不确定度评定

讨论了用GB/T7531标准方法测定精对苯二甲酸中灰分的测量结果不确定度的各种影响因素。通过对影响结果不确定度分量的分析和量化,以及分量之间相关性的计算,求出精对苯二甲酸中灰分测量结果的标准不确定度和扩展不确定度,对测定结果进行了表述。