采用纳米Al203和碳纳米管颗粒强化CO2吸收的理论及实验研究（英文）

The influence of nano-particles on CO2 absorption was studied experimentally in a stirred thermostatic reactor. Nano-A1203 and carbon nanotube （CNT） particles which showed different hydrophobic properties were chosen for the investigation. The experimental results were compared with that of micron-size activated carbon （AC） and Al2O3 particles. From the results, no enhancement by micron-size A1203 was found, and with the increase of A1203 concentration, the enhancement factor decreased. However, nano-Al203 showed a weak enlaancement tor me COz absorption. AC and CNT particles all intensified the gas-liquid mass transfer effectively, yet the trend of the enhancement factor with stirring speed for the two particles was different. With increasing stirring speed, the enhancement factor of AC particles was decreased, wl＇iereas in CNT suspensions it was increased. The experimental phenomena demonstrated a difference in enhancement mechanism for different size particles. For nano-particles, besides the influence of adsorbability and hydrophobicity, the micro-convection caused by Brownian motion should be also taken into account. Considering the micro-convection effect, a theoretical model was developed to shed light on the absorption enhancement bv nano-oarticles.     

MgO-Cr2O3/Al2O3催化剂对丙烷脱氢反应的再生性能

制备了Mg改性Cr₂O₃/Al₂O₃催化剂,利用XRD,UV-Vis,XPS,H₂-TPR,NH₃-TPD,TG等方法考察了新鲜和再生后催化剂的结构与性能。实验结果表明,助剂Mg的添加有利于催化剂再生后的物相结构稳定;随再生次数的增加,催化剂孔径增大,比表面积降低,催化剂表面Cr⁶⁺含量降低,Cr⁶⁺组分逐渐不可逆还原为Cr³⁺等稳定状态;催化剂表面主要为弱酸和中强酸,随再生次数的增加,酸量减少,但酸强度增加,Cr物种价态及其与载体的相互作用影响了表面酸性进而影响了催化剂活性;新鲜催化剂催化活性略高于再生催化剂,经多次再生后催化剂性能趋于稳定,丙烷转化率稳定在30%左右,丙烯选择性在88%以上。     

新型吸收剂在湿法烟气脱硫中的应用

SO2是现今主要的大气污染物,而我国以煤为主要燃料的特点使SO2的污染日益严重。因此,控制SO2的排放,积极应用二氧化硫控制技术,对改善大气污染状况至关重要。介绍了传统的石灰石一石膏法,探讨了硫酸亚铁法、有机胺法、尿素法、亚硫酸钠循环法、柠檬酸钠循环法、过氧化氢法等应用新型吸收剂的湿法烟气脱硫技术,并对它们的优缺点做了简单评述。     

分子筛疏水改性对CO2吸收强化的影响

Two methods of the modification of zeolite were employed:framework element modification and surface coating,and the influence of the zeolites before and after modification on the CO₂ absorption was investigated.It was found that although hydrophobicity of zeolite could be obtained by means of the surficial organic coating in the method of surface coating modification,partial channel of zeolite would be plugged,as a result,leading to the surface area reducing greatly.Distinctively,the framework element modification method could maintain not only complete lattice structure and adsorption capability of zeolite,but would also obtain a good hydrophobic property.Consequently,significant enhancement on gas absorption by this modified zeolite was achieved and up to a maxi-mum enhancement factor of 2.62.This shows that the solid particles with good enhancement role to gas absorption need not only good adsorptive capability but also certain hydrophobicity.An unsteady heterogeneous model was employed to predict enhancement factor and the calculated results agree well with the experimental data.     

化工设计课程教学改革模式研究

在化工工程中,化工设计作为可以将化工工程从设想转变为现实的建设,帮助化工工程更好地进行建设和设计。在化工设计的教学中,化工设计涉及了多种不同类型的知识,从化工工艺学、化工设备、化工热力学和物理化学等多种方面进行综合学习。在化工设计课程的教学中,必须要通过对教学模式的改革来帮助教师更好地进行教学,以便提高化工设计课程的教学效率。     

第三分散相液滴增强气体吸收的一维非稳态非均相传质模型

A model for one-dimensional unsteady heterogeneous mass transfer was developed based on Danckwerts’ surface renewal theory in order to describe the mass transfer enhancement of absorption process for a slightly soluble gas in a gas-liquid-liquid system. The model accounts for the mass transfer resistance within the dispersed phase and the effect of emulsion viscosity on mass transfer. An analytical solution for enhancement factor was obtained by Laplace domain transformation. The absorption rates of carbon dioxide in the dodecane-in-water and castor oil-in-water systems were measured in a thermostatic reactor, and the enhancement factors were calculated at different volume fractions of dispersed phase and stirrer speeds. The model predictions agree well with the experi-mental data.     

无溶剂法烷基烯酮二聚体的制备及工艺改进

以三乙胺和硬脂酰氯为原料,采用无溶剂法制备了烷基烯酮二聚体(AKD),为了避免蒸馏法回收过量三乙胺所带来的高能耗,提出了一种新的工艺对AKD后处理过程进行改进,反应产物在热过滤除去三乙胺盐酸盐后,在低温下过滤得到AKD,所得滤液循环使用。研究了不同参数对反应收率和AKD纯度的影响,最佳反应温度为60℃,反应时间为1.5 h。当三乙胺和硬脂酰氯的摩尔比R_(TEA/STC)5时,尽管首次采用新鲜原料时反应收率较低,但并不影响后续的循环反应收率,循环反应收率可达86%,而且较高的原料配比可使反应在较低的黏度下进行。多次的循环实验表明,采用文中所提出的方法,操作易于控制、能耗低、反应条件温和,值得进行工业推广。     

聚合氯化铁与阳离子瓜尔胶的复配及其对染料墨水的脱色性能

为了提高聚铁絮凝剂对染料墨水的脱色性能,采用聚合氯化铁(PFC)和阳离子瓜尔胶(CGG)制备聚合氯化铁-阳离子瓜尔胶(PFC-CGG)复合絮凝剂,考察不同因素,如PFC与CGG复配比例、絮凝剂投加量、废水初始pH值及废水电导率等对墨水废水脱色率的影响,并利用Zeta电势对脱色机理进行分析。结果表明:相对于单独使用PFC和CGG,PFC和CGG复配有效地提高了脱色性能,中性条件下,在复配质量比mCGG∶mPFC=0.05时PFC-CGG脱色率达到95.3%,明显高于相同条件下PFC和CGG的脱色效果;FT-IR及SEM对絮凝剂的结构及表观形貌的表征显示CGG和PFC之间产生了交联,这种交联使得PFC-CGG复合絮凝剂在PFC较强电中和作用的基础上又增加了CGG长分子链的卷扫网捕能力,使脱色效果得以有效提高。     

活性炭粒子对K2CO3溶液中CO2化学吸收的强化

The enhancement of chemical absorption of CO2 by K2CO3/H2O absorbents in the presence of activated carbon (AC) particles was investigated. The results show that the gas absorption rates can be enhanced significantly in the presence of AC particles,and the maximum enhancement factor 3.7 was observed at low stirring intensities.The enhancement factor increased rapidly with the solid loading during the initial period of absorption and then became mild gradually to a maximum value. Both the liquid-solid contact area and the probability of solid particles residing at the gas-liquid interface decreased with the increase of the particle size,leading to a negative effect on the enhancement of mass transfer. The influence of the particles on gas absorption decreased with the reaction rate. The stirring speed changed the interfacial coverage and mass transfer rate on the liquid side and consequently affected the mass transfer between the gas and liquid phases; the enhancement factor decreased with the stirring intensity. A heterogeneous two-zone model was proposed for predicting the enhancement factor and the calculated results agreed well with the experimental data.     

微细固体颗粒对CO2吸收速率的影响

利用恒温反应器研究了颗粒性质对CO2在浆液中吸收的影响。实验选用三种溶剂：水、环己烷和大豆油,在其中分别加入不同性质的固体颗粒：活性炭、活性氧化铝和硅胶作为研究体系。结果发现,水溶液中只有活性炭表现出了明显的吸收强化效果;而在环己烷溶液中则相反,活性炭失去了强化作用,Al2O3和硅胶却对吸收起到了促进效果。由此说明能够具有吸收强化效果的颗粒需要具有两方面的性质：憎溶剂性及对溶质较高的吸附容量。同时,根据实验结果,增强因子随颗粒浓度的增加会渐进地趋于一个恒定值;搅拌速度提高强化因子会随之降低。表明强化因子与颗粒在气液界面的覆盖率有关,搅拌速度提高界面覆盖率下降。