基于Aspen Plus的气流床煤气化炉三段平衡模型(英文)

A three stage equilibrium model is developed for coal gasification in the Texaco type coal gasifiers based on Aspen Plus to calculate the composition of product gas, carbon conversion, and gasification temperature. The model is divided into three stages including pyrolysis and combustion stage, char gas reaction stage, and gas phase reaction stage. Part of the water produced in the pyrolysis and combustion stage is assumed to be involved in the second stage to react with the unburned carbon. Carbon conversion is then estimated in the second stage by steam participation ratio expressed as a function of temperature. And the gas product compositions are calculated from gas phase reactions in the third stage. The simulation results are consistent with published experimental data.     

孔隙尺寸、盐度和气体组分对水合物相平衡的影响(英文)

An experimental device was set up to study the hydrate formation conditions. Effects of pore size, salinity, and gas composition on the formation and dissociation of hydrates were investigated. The result indicates that the induction time for the formation of hydrates in porous media is shorter than that in pure water. The decrease in pore size, by decreasing the size of glass beads, increases the equilibrium pressure when the salinity and temperature are kept constant. In addition, higher salinity causes higher equilibrium pressure when the pore size and temperature are kept constant. It is found that the effects of pore size and salinity on the hydrate equilibrium are quite different. At lower methane concentration, the hydrate equilibrium is achieved at lower pressure and higher temperature.     

甲烷水合物储气实验研究

1 INTRODUCTION Methane gas hydrates (MGH) are solid phase crystalline inclusion compounds (also called clathrates) that consist of a host water lattice with cavities in which methane gas is caged as a guest gas.Methane gas hydrate might contain 164 volumes (at standard pressure and temperature)of methane and 0.87 volumes of water per volume hydrate.     

STUDY FOR NATURAL GAS HYDRATE CONVERSED FROM ICE

Natural gas hydrates are crystalline clathrate compounds composed of water and gases of small molecular diameters that can be used for storage and transport of natural gas as a novel method. In the paper a series of experiments of aspects and kinetics for hydrate formed from natural gas and ice were carried out on the industrial small scale production apparatus. The experimental results show that formation conditions of hydrate conversed from ice are independent of induction time, and bigger degrees of supersaturation and supercooling improved the driving force and advanced the hydrate formation. Superpressure is also favorable for ice particle conversion to hydrate. In addition, it was found there have an optimal reaction time during hydrate formation.     

GIBBS ENSEMBLE MONTE CARLO SIMULATION OF VAPORLIQUID EQUILIBRIA FOR SIMPLE FLUIDS

The Gibbs ensemble Monte Carlo simulation method has been investigated and used to calculate the vaporliquid equilibria of a real binary mixture, argon-methane. In this simulation, the micro-structural and macroscopic properties, including the distribution function, internal energy, densities and compositions of coexisting vapor and liquid phases as well as the enthalpy of vaporization are obtained. Compared with experimental data and calculated results from equations of state, our simulated phase equilibrium properties are of good accuracy, which demonstrates that this simulation methods is a powerful tool in research on phase equilibria of fluids.     

Application of response surface methodology for optimization of purge gas recycling to an industrial reactor for conversion of CO2 to methanol

Nowadays, by the increasing attention to environment and high rate of fuel production, recycling of purge gas as reactant to a reactor is highly considered. In this study, it is proposed that the purge gases of methanol production unit, which are approximately15.018 t·h~(-1) in the largest methanol production complexes in the world, can be recycled to the reactor and utilized for increasing the production rate. Purge gas streams contain 63% hydrogen,20% carbon monoxide and carbon dioxide as reactants and 17% nitrogen and methane as inert. The recycling effect of beneficial components on methanol production rate has been investigated in this study. Simulation results show that methanol production enhances by recycling just hydrogen, carbon dioxide and carbon monoxide which is an effective configuration among the others. It is named as Desired Recycle Configuration(DRC) in this study. The optimum fraction of returning purge gas is calculated via one dimensional modeling of process and Response Surface Methodology(RSM) is applied to maximize the methanol flow rate and minimize the carbon dioxide flow rate. Simulation results illustrate that methanol flow rate increases by 0.106% in DRC compared to Conventional Recycle Configuration(CRC) which therefore shows the superiority of applying DRC to CRC.     

Mg2+在胜利褐煤中的负载量对其平衡复吸水含量的影响及其机理分析（英文）

Mg ion-exchanged samples were prepared with acid-washed Shengli lignite. The chemical composition of the ash of the raw sample was determined by X-ray fluorescence. The equilibrium adsorption water contents of sam-ples were determined in a range of relative humidity. The ion-exchange process was characterized by FT-IR, ash content, and pH value. A possible mechanism is proposed for equilibrium adsorption water of ion-exchanged samples at different humidities. The extent of ion-exchange reaction between Mg2+and lignite is control ed by the concentration of Mg2+in MgSO4 solution. The effect of Mg2+on equilibrium adsorption water content varies with relative humidity and content of Mg2+. The factor that controls equilibrium adsorption water content at low relative humidity is water interactions with sorption sites, which are Mg2+–carboxyl group complex. At middle relative humidity capil ary force between Mg2+–water clusters Mg+(H2O)n and capil ary is more impor-tant. At high relative humidity, free water–free water interactions are more significant.     

UNIFAC模型法计算含己内酰胺体系的相平衡(英文)

An extended liquid-liquid equilibrium (LLE) UNIFAC model is proposed to describe phase equilibria of mixtures containing caprolactam. In this model, caprolactam is introduced as a new group. New group interaction parameters are calibrated from 156 sets of liquid-liquid equilibrium data. The present model gives satisfactory correlation and prediction in liquid-liquid equilibrium, including quaternary systems containing the mixed solvent of an alcohol and an alkane. The model can be applied to predict caprolactam solubility in water and benzene accurately. Freezing point and vapor-liquid equilibrium of binary systems containing caprolactam are also predicted with the extended LLE UNIFAC model. Satisfactory prediction results are obtained.     

采用CO2吸附剂吸附强化的甲烷水蒸汽反应制药厂氢过程特点

The objective of the present study is to characterize the production of hydrogen with a sorptionenhanced steam-methane reaction process using Ca(OH)2 as the CO2 adsorbent. Theoretical equilibrium compositions at different operation conditions were calculated using an iterative method. It was found that with Ca(OH)2 as the CO2 sorbent, the concentration of CO2 adsorption was reduced in the product stream, that gave rise to higher methane conversion and higher H2 concentration. An experimental setup was built to test the theoretical calculation. The effects of sorbents and the particle size of Ca(OH)2 on the concentration of CO2 and H2 were investigated in detail. Results showed that the reactor packed with catalyst and Ca(OH)2 particles produced H2 concentration of 94%. It was nearly 96% of the theoretical equilibrium limit, much higher than H2 equilibrium concentration of 67.5% without CO2 sorption under the same conditions of 500℃, 0.2 MPa pressure and a steam-to-methane ratio 6. In addition, the residual mole fraction of CO2 was less than 0.001.     

多孔载体海绵对CH4-N2-O2瓦斯气体水合分离影响（英文）

The findings were presented from laboratory investigations on the hydrate formation and dissociation processes employed to recover methane from coal mine gas.The separation process of coal mine methane(CMM) was carried out at 273.15K under 4.00 MPa.The key process variables of gas formation rate,gas volume stored in hydrate and separation concentration were closely investigated in twelve THF-SDS-sponge-gas systems to verify the sponge effect in these hydrate-based separation processes.The gas volume stored in hydrate is calculated based on the measured gas pressure.The CH4 mole fraction in hydrate phase is measured by gas chromatography to confirm the separation efficiency.Through close examination of the overall results,it was clearly verified that sponges with volumes of 40,60 and 80 cm 3 significantly increase gas hydrate formation rate and the gas volume stored in hydrate,and have little effect on the CH4 mole fraction in hydrate phase.The present study provides references for the application of the kinetic effect of porous sponge media in hydrate-based technology.This will contribute to CMM utilization and to benefit for local and global environment.     

油水乳液体系水合分离塔的模拟计算

在水合物法辅助分离乙烯裂解气流程中,水合物分离塔是非常关键的单元操作设备。气体混合物在塔内的分离过程与气体吸收塔类似,但因涉及气-液-液-固4相,所以计算更加复杂。将速率法和平衡级法相结合,提出了油水微乳体系吸收-水合分离塔的模拟计算方法。模拟计算了一典型乙烯裂解气在水合分离塔内的分离状况。为了确定适宜的操作条件,分别考核计算了操作温度和气液比对分离效果及能量消耗的影响。所得结果对水合分离塔的设计、操作条件的确定以及乙烯裂解气分离流程的制定有很重要的意义。计算结果还表明,通过水合物技术在0℃左右可实现氢气、甲烷和C₂以上组分的有效分离,因此可以节约大量制冷功耗。     

水合物法分离H2＋CH4体系的非平衡级模拟

针对H₂+CH₄体系在四氢呋喃(THF)水溶液中H₂的分离，提出了适合水合物多级分离技术的非平衡级算法——微元法，对此方法做了详尽的阐述.以湿壁塔为例，采用微元法计算了气、固相组成及其负荷，同时对不同温度、压力以及流量对水合物多级分离的影响做了比较.     

包硅改性纳米碳酸钙应用于高温CO2吸附的性能

引言 二氧化碳吸附强化制氢(SERP)的原理是将甲烷水蒸气重整反应过程产生的CO2用吸附剂脱除,从而打破化学反应平衡,降低反应平衡常数,使反应温度由800～1000℃降低至500℃左右,使制氢反应条件更温和、能耗更低.该技术的工业可行性研究的关键是甲烷水蒸气重整反应过程中采用的高温CO2的吸附剂的性能研究[1].     

近-超临界水中Ni/ZrO2催化气化聚乙二醇水溶液的产氢特性

在连续流超临界水反应器中,以Ni/ZrO₂为催化剂,以聚乙二醇（polyethylene glycol,PEG）水溶液作为研究对象,考察了近-超临界状态下的有机质气化产氢特性。实验结果显示,PEG的气化产物主要成分为H₂、CO、CH₄和CO₂;其中,当加入90 g 15% Ni/ZrO₂时,在430℃、压力24 MPa、停留时间300 s的条件下,可以生成70.14 mmol H_2^·（g PEG）^-1,为不加入催化剂时的5.1倍,为加入90 g ZrO₂时的2.6倍,相应的TOC去除率、碳气化率和氢气化率分别达到88.84%、88.50%和169.40%;增大活性组分Ni的质量分数可以提高气化效果,在410℃、压力24 MPa、停留时间180 s的条件下,Ni质量分数从5%提高到15%时,TOC去除率、碳气化率和氢气化率分别从45.31%、44.55%和78.25%提高到58.66%、58.16%和112.49%;反应温度的上升和停留时间的延长对气化效果有正影响,明显提高H₂的摩尔产率;PEG浓度的上升可抑制水气转换反应并促进甲烷化反应的进行而导致其气化效率下降,其中,H₂产量急剧下降,CO₂产量先上升后下降,而CH₄产量随PEG浓度上升而上升。研究结果证明了所研制的Ni/ZrO₂催化剂在近-超临界水中对PEG的催化气化特别是产H₂表现出高活性,在达到相同反应效率前提条件下使反应温度降低约80℃。     

硅胶载体上制备纳米TiO2

引　言通过控制反应空间的尺度而限制晶核的生长 ,为制备纳米粒子提供了一种相对简易的方法 ,微乳液和反相微乳液就是典型的纳米反应器[1～ 3] ,而利用硅藻土、高岭土等材料的层状结构和孔隙限制粒子生长、制备纳米复合材料的发展也很快[4 ] .近年来 ,Dekany等在这一思想基础上     

水溶液中新生态MnO2对苯酚的吸附作用

研究了新生态MnO^₂对水溶液中苯酚的吸附作用.对一些影响因素，如pH、高价正离子Al³⁺和高价负离子PO^3-₄进行了考察，并探讨了反应机理.实验结果表明，新生态MnO₂对苯酚的吸附等温线为“S”形，对苯酚的吸附过程包括表面吸附和孔内扩散两部分.pH在6～9的范围内，随pH升高苯酚吸附量下降，但变化不大;当pH≥10时，苯酚去除率几乎降为零.少量铝离子有利于苯酚的吸附.因为铝离子吸附在新生态MnO₂表面，改变了新生态MnO₂的表面性质，有利于苯酚的吸附.磷酸根离子极易与苯酚络合而带负电荷，不利于新生态MnO₂对苯酚的吸附.     

纳米MnO2离子筛的锂吸附性能

通过控制水热合成反应条件制备了不同晶相的一维纳米MnO₂，进一步用浸渍法制备了Li-Mn-O三元氧化物前驱体，并经酸处理后得到对锂离子具有特殊选择性的离子筛。用XRD、TEM、吸附等温线及反应动力学等手段对产物的晶相结构和锂吸附性能进行了研究。实验结果表明，反应物浓度对MnO₂不同晶面的生长速率有不同的影响；从TEM图像中可以清楚地看到，水热合成法制备出了尺寸为φ5nm×400nm的一维MnO₂纳米线；在pH＝9.19时每克离子筛的单分子层锂离子饱和吸附量Q_m为2.43mmol·g^-1；吸附速率常数为2.17×10^-6 s^-1；吸附量随溶液pH值的增加而增加，当pH=12.5时，相应的吸附量为3.47mmol·g^-1。     

Ni-Rh/Al2O3催化剂上甲烷-氘化氢间的氢氘交换性能

采用Ni-Rh/Al₂O₃催化剂,在固定床微型反应器上考察了Ni-Rh/Al₂O₃催化剂对甲烷的氢氘交换的催化性能。结果表明,在进料组成不变的条件下,当温度低于692K时,甲烷的转化率随温度的升高而快速升高,当温度高于692K时,甲烷的转化率不随温度的升高而变化;当温度低于692K时,甲烷的转化率随反应物流量的增加而明显减小,当温度高于692K时,甲烷的转化率基本不随温度和反应物流量的变化而变化;在反应物总流量不变的条件下,当HD/CH₄流量比为1.1～2.5时,甲烷的转化率随着HD/CH₄流量比增加而减小。     

球形TiCl4/MgCl2催化剂引发丙烯气相聚合动力学

采用微机在线控制的半连续烯烃聚合反应器，在加压条件下进行了球形TiCl₄/MgC_l2催化剂催化的丙烯气相聚合，测定了单体瞬时聚合速率等重要的动力学数据，考察了不同聚合条件对聚合动力学的影响，并用Flory-Huggins方程估算了聚合物非晶区中的单体浓度C_m.研究表明聚合速率与C_m成正比;丙烯聚合速率在反应一开始就迅速衰减，之后是缓慢的衰减.提出了一个n级衰减的丙烯气相聚合动力学模型，根据实验数据拟合得到了模型的各个参数，其中活性中心的衰减级数为2.5，气相聚合的表观增长活化能为77.1 kJ•mol^-1.用该模型可以较好地模拟加压条件下的丙烯气相聚合动力学行为.     

迎头色谱法测定人参皂苷Rg1和Re的吸附量

制备色谱分离条件优化的基础是吸附等温线的测定及保留时间的预测。本文以人参皂甙Rg₁、Re为研究对象，用色谱单柱制备了人参粗粉中的人参皂甙Rg₁、Re,以迎头法测定了人参皂甙Rg₁、Re在C₁₈球形固定相中的吸附等温线，在竞争Langmuir模型基础上确定了吸附参数G和b，并应用非线性色谱理论的结果预测了人参皂甙Re的保留时间，上述结果与实验值进行了比较，平均相对误差为3.68%。在实验中发现了运用竞争Langmuir模型进行拟合的一些问题并进行了讨论。