硫化氢的提纯及应用

概括了介绍了硫化氢的应用及提纯工艺。     

膜分离-变压吸附联合工艺生产燃料电池氢气

将膜分离技术和变压吸附两种气体分离与净化技术相结合．充分发挥了两种工艺模式的优点．使得装置整体性能指标在稳定性、产品品质和氧气回收率上均有优异的表现,最终使得单位原料气的获利大幅挺高。另外,联合工艺具有广泛的适应性,能够灵活采用各种运行模式以适用于各种不同的气源。     

氢气的分离与纯化技术的发展

本文在叙述了氢气的来源和传统的分离与纯化技术的基础上,论述了 PSA 法Prism 法、低温法、金属氢化物法等在氢气的分离与纯化方面的开发现状、工艺过程、分离原理及其发展前景。     

Pinch Location of the Hydrogen Network with Purification Reuse

In the hydrogen network with the minimum hydrogen utility flow rate, the pinch appears at the point with zero hydrogen surplus, while the hydrogen surpluses of all the other points are positive. In the hydrogen purity profiles, the pinch can only lie at the sink-tie-line intersecting the source purity profile. According to the alternative distribution of the negative and positive regions, the effect of the purification to the hydrogen surplus is analyzed. The results show that when the purification is applied, the pinch point will appear neither above the purification feed nor between the initial pinch point and the purification feed, no matter the purification feed lies above or below the initial pinch point. This is validated by two case studies.     

乙炔气体湿法净化及改造

针对50万米~3/年乙炔站清净工序的生产性质及要求,采用了以次氯酸钠液湿法净化乙炔气的方法,并阐述了清净工序的改造设计。净化后的乙炔气中硫化氢、磷化氢含量总和小于10ppm,净化效果好,安全可靠,成本低,效益好,值得乙炔站推广。     

人工神经网络专家系统注塑工艺参数在线调控系统

依据专家系统控制原理提出注塑工艺参数智能调控系统的结构,具体说明了人工神经网络与专家系统相结合的方法,描述了用BP神经网络产生专家控制系统规则的过程。     

Comparative Analysis of Synthetic Natural Gas versus Hydrogen Production from Bagasse

A rigorous and comparative evaluation of two biomass‐to‐gases (BtG) conversion routes was performed and, according to this outcome, it is suggested which of the options evaluated is most desirable. These options, the hydrogen and synthetic natural gas (SNG) production, were designed in Aspen Plus process simulation software. Sugar cane bagasse was considered as feedstock. Mass and energy balance data were extracted from the simulations, and consequently thermodynamic (exergy analysis), economic (financial and uncertainty analysis), and environmental (CO₂ emissions) evaluations were carried out. Exergy and environmental analysis favor the SNG production while the hydrogen route provides higher profits.     

基于双轨图的网络控制系统稳定性分析

网络控制系统中网络时延的引入,影响系统性能,甚至引起不稳定.为了便于分析网络时延对控制系统稳定性的影响,采用简单的比例控制器,利用双轨图,分析了单摆网络控制系统存在网络时延时的稳定性问题,给出了不稳定范围和稳定范围.同时也给出了单摆网络控制系统稳定性与阻尼系数之间的关系.结果显示利用双轨图进行有时间延迟的网络控制系统稳...     

工艺参数对沉降斑影响的实验研究

采用实验方法考察工艺参数对沉降斑的影响。基于一个带凸台的平板模具,采用L27(313)正交矩阵进行实验,研究了几何尺寸、熔体温度、注射时间、保压压力及保压时间对厚度突变处沉降斑形成的影响,同时还考虑了熔体温度和注射时间以及保压压力和注射时间之间的交互作用影响;通过性噪比分析和F检验优化成型工艺条件并对工艺参数的影响进行显著性分析。结果表明,对于厚度突变的平板制品,厚度突变的程度对其沉降斑形成的影响最大,其次为熔体温度,保压压力,保压时间等;采取减小厚度变化,降低熔体温度或增加保压压力和保压时间等措施,可以减小厚度突变处沉降斑,从而减少其对外观质量的影响;因素之间的交互作用对制品沉降斑的形成有一定的影响,熔体温度B和注射时间C之间的交互作用影响较为明显,而保压压力D和注射时间C之间的交互作用对该质量指标的影响最小,可以并入误差。     

A Process Integration based Approach for the Analysis of an Evaporator System

A scalable new mathematical model based on the principles of Process Integration has been developed for the analysis of multiple effect evaporator (MEE) systems. It uses the concepts of stream analysis, temperature path and internal heat exchange for the formulation of the model equations. In addition to the above concepts, the model also takes into account the variable physico‐thermal properties of steam/vapor, condensate and liquor, while simulating the MEE system. The present model consists of a set of linear equations and does not present any stability or oscillation problems during solution as is generally seen in the case of models that are based on sets of nonlinear equations. The model equations are automatically generated through a computer program and the model was run for three different liquor and flow sequences to prove its utility. The results obtained are compared with published models.     

Purification of Wet‐Process Phosphoric Acid by Hydrogen Peroxide Oxidation,Activated Carbon Adsorption and Electrooxidation

In this work, three technologies are studied for the purification of phosphoric acid produced by the wet process: chemical oxidation with hydrogen peroxide, adsorption onto activated carbon, and electrochemical oxidation by boron‐doped diamond anodes. The treatment of wet‐process phosphoric acid by chemical oxidation with H₂O₂ as oxidizing agent can remove 75 % of the initial TOC as maximum, indicating that this wet‐process phosphoric acid contains an important amount of organics that cannot be oxidized by hydrogen peroxide under the operation conditions used. High temperatures and hydrogen peroxide/TOC ratios close to 150 g H₂O₂/g TOC allow obtaining the best chemical oxidation results. The adsorption onto activated carbon can remove between 40 and 60 % of the initial TOC as maximum. Adsorption times of 2 hours and activated carbon/WPA ratios close to 12 g AC/Kg WTP assure both steady state and maximum adsorption of organics. The electrochemical process is the only technique by which complete mineralization of WPA organics can be achieved. Operating at 60 mA cm^–2 and at room temperature, high current efficiencies are achieved which only seem to decrease by mass transport limitations.     

Hopfield神经网络与专家系统相结合的换热网络设计方法有效性分析

在利用Ｈｏｐｆｉｅｌｄ神经网络（ＨＮＮ）模型搜索换热网络中最佳物流匹配方式时,通过建立专家系统来描述匹配过程中必须考虑的定性及定量因素,协助调整ＨＮＮ模型运行过程中的寻优方向,以减小ＨＮＮ模型的搜索空间,保证问题的全局优解。文章通过实例说明了该混合方法的有效性。     

基于缩痕最小的汽车保险杠成型工艺参数优化

针对某汽车保险杠出现的缩痕问题,在实验设计及数值模拟的基础上,通过方差分析技术确定了该保险杠缩痕指数的显著性会影响成型工艺参数;采用响应曲面法建模理论,建立了可以适当描述该保险杠缩痕指数与主要成型工艺参数之间的评价数学模型;并运用改进遗传算法优化了该模型,得出了一组基于缩痕最小的工艺参数,并经模拟实验验证了该优化组合的工艺可行性。     

化工设备设计部门网络系统的建立与实施

针对目前化工设备设计人员使用单机工作,给设计带来诸多不便,笔者根据自己的实际建网经验,提出了适合化工设备设计部门使用的廉价局域网,并给出了具体建立方法与实施步骤。     

渣油加氢处理过程中氢分压对杂质脱除率的影响

针对渣油加氢过程中不同功能催化剂级配装填的特点,运用渣油加氢中试装置,考察了氢分压对不同活性催化剂加氢处理产物性质的影响,分析了渣油中杂质的脱除分布规律。结果表明,在渣油加氢处理过程中,氢分压恒定时,随着加氢深度的增加,渣油中硫、氮、金属和残炭等杂质含量都降低;同一反应器中,随着氢分压升高,加氢产物中杂质含量总体呈降低趋势。随氢分压升高,渣油中各杂质的总脱除率先升高后略有降低,其中氮和残炭的总脱除率变化最明显。氮主要是在R4和R5反应器中脱除,而残炭则主要是在R2、R3和R4反席器中脱除．并日．两种杂质的脱除率随氧分压的变化旱姗不同的蛮化规律。     

基于Aspen Hysys的沼气中N_2对净化工艺的影响

沼气净化技术主要包括脱硫、脱水、脱碳等工艺,而很少涉及N_2对净化工艺的影响。系统地研究了沼气中氮含量对其净化效果的影响。利用化工过程模拟软件,对沼气虚拟临界性质、热值、定压比热容等进行了物性分析,以及对压缩机功耗进行了模拟计算。研究发现,随着N_2含量从0%增至9%时,沼气的临界温度下降12.53℃,热值下降9.03%;N_2含量的增加,也使得在脱碳工序中,对沼气进行冷却降温时所需的换热量增加,且冷却效率明显降低;在相同排气压强工况下,随着N_2含量的增加,压缩机功耗增加明显。     

基于导数分析的反应器网络综合方法

对反应器网络综合问题进行了研究，分析了瞬时选择性对关键组份组成的偏导数与最佳反应器类型之间的关系，给出了确定最优反应器的三条规则。对δS/δC符号不变的反应体系，用这些规则可获得最优反应器网络。对一般的反应体系，假设了五种典型S－CA曲线所对应的反应过程，分别对不同曲线类型给出了确定最优反应器网络的方法。此外，按本文方法所得的最优反应器网络结构是一个CSTR或PFR或由CSTR、PFR组成的串联结构。由dS/dCA的符号及其变化情况决定。给出了两个说明本文方法的例子，结果表明本文方法简单并可获得与文献相同或相似的结果。     

基于缩痕最小的空调面框注塑成型工艺参数优化

针对带有网格的框形薄壁注塑件容易出现缩痕的问题,开展基于缩痕最小的空调面框注塑成型工艺参数优化研究。首先构建空调面框三维几何模型,设计浇道系统和冷却流道,在运用Moldfl ow数值模拟和四水平正交试验L16(45)的基础上,以注射时间、模具温度、熔体温度、相对保压压力、保压时间为设计变量,采用极差分析和方差分析得到各参数对缩痕指数的影响程度,并获得了最优的工艺参数组合,其缩痕指数降低为2.159%,最后通过注塑成型试验验证该方法的有效性。这为框形薄壁注塑件低成本高质量设计提供了一种新的途径。     

基于神经网络-遗传算法优化制氢工艺水碳比

根据某炼油厂制氢车间的生产数据,用人工神经网络(ANN)的反向传播(BP)算法建立了制氢装置转化生产中的水碳比神经网络预测模型,生产数据的检验表明,ANN方法能准确地关联和预报制氢装置转化生产中的水碳比,水碳比预测平均相对误差为2．83％;该神经网络预测模型用遗传算法优化并得到了最佳制氢工艺操作条件。     

Kinetic Study and Optimum Control of the Ozone/UV Process Measuring Hydrogen Peroxide Formed In-situ

This study was conducted to develop a kinetic model of the ozone/UV process by monitoring the trend of in-situ hydrogen peroxide formation. A specifically devised setup, which could continuously measure the concentration of hydrogen peroxide as low as 10 μg/L, was used. The kinetic equations, comprised of several intrinsic constants with semi-empirical parameters (k_chain and k_R3) were developed to predict the time varied residual ozone and hydrogen peroxide formed in situ along with the hydroxyl radical concentration at steady state,[OH°]_ss, in the ozone/UV process. The optimum ozone dose was also investigated at a fixed UV dose using the removal rate of UV absorbance at 254 nm (A₂₅₄) in raw drinking water. The result showed that the continuous monitoring of hydrogen peroxide formed in situ in an ozone/UV process could be used as an important tool to optimize the operation of the process.