不同类型双效精馏流程节能特性的研究

本研究利用工程模拟软件,选择乙醇-水二元物系为模型,对不同类型的3种双效精馏流程(平流双效精馏、顺流双效精馏和逆流双效精馏)进行了流程模拟,考查了不同的原料组成、不同的进料温度在分离要求相同的情况下,与普通精馏塔相比,各类型流程节能率的变化情况。结果表明,(1)原料组成变化对平流双效精馏节能率基本没影响,进料温度在泡点下,平流双效精馏节能率更高;(2)对于顺流双效精馏,进料温度的变化对其节能率的影响较大,进料温度越高两种流程的节能率越低,原进料组成中轻组分含量越多,节能率越高;(3)逆流双效精馏流程适合进料中低沸组分浓度高于高沸组分浓度的物系精馏分离。低沸组分的浓度越大,应用逆流双效精馏流程的节能率会越高。对于逆流双效精馏流程的3种不同流程的节能率均随着进料温度的升高而下降。     

基于双效精馏回收乙醇的节能效果模拟研究

采用NRTL-RK热力学计算模型,通过稳态模拟优化计算,基于双效精馏流程回收乙醇,考察进料温度对三种不同结构的双效精馏流程节能效果的影响。研究结果表明:双效精馏A节能率在33%以上,较适合低温气体进料;双效精馏B节能率约为16%左右,双效精馏C节能率约为8%左右,且双效精馏B和C较适合高温气体进料。研究结果可为回收乙醇的双效精馏流程的选择和进料温度的确定提供理论依据。     

新型节能精馏流程——气体进料作再沸器热源双效精馏节能率的研究

由于常见的双效精馏、顺流双效精馏、逆流双效精馏、平流双效精馏在泡点以上温度进料时,节能效果不是很理想,针对泡点以上温度进料,我们研究了新型节能流程--气体进料作再沸器热源双效精馏流程,以乙醇-水为实验物系,通过模拟计算,考察进料组成和进料温度对其节能率的影响.研究结果表明,当进料中轻组分含量大于0.4时,气体进料作再沸器热源双效精馏A流程的节能效果最好,节能率在36%以上.当进料中轻组分含量小于0.4时,气体进料作再沸器热源双效精馏B节能效果最好,节能率均在20%以上.当进料温度在露点附近或者高于250℃时这3种流程节能效果较好.     

逆流双效精馏节能率的模拟研究

以乙醇-水为物系,通过模拟计算,研究进料组成和进料温度对三种逆流双效精馏节能效果的影响.研究结果表明,逆流双效精馏B流程的节能效果最好,当进料中轻重组分的含量相当时,节能率高达49.83%.逆流双效精馏C流程的节能效果次之,逆流双效精馏A流程的节能效果最低,这两种流程最好应用在进料中轻组分含量大于重组分含量的条件下.三种逆流双效精馏流程的节能率均随着进料温度的升高而下降,因此逆流双效精馏最好应用在进料温度小于泡点温度的情况下.     

一种新型高效节能双效精馏流程的开发与研究

由于常见的平流双效精馏、顺流双效精馏、逆流双效精馏在进料温度小于泡点温度时,节能效果显著,在进料温度高于泡点温度时,节能效果不是很理想。因此针对泡点以上气体进料,在双效精馏基础上进行改进,开发了新型节能流程——气相进浓缩塔双效精馏流程,包括三种不同流程,以乙醇-水为实验物系,通过模拟计算,考察进料组成和进料温度对其节能率的影响。验证结果表明,其节能率最高达54%,最低也在15%以上,已满足了工业节能的需要。     

顺流双效精馏节能率的模拟研究

本研究采用工程模拟软件对顺流双效精馏进行了模拟设计和优化,以乙醇-水物系为模型,对单塔精馏和二种顺流双效精馏进行模拟,在分离任务相同的情况下,考察进料组成、进料温度对各精馏流程的能耗的影响,与单塔精馏相比顺流双效精馏节能效果明显,达到了节能减排的目的。     

顺流双效精馏节能率的模拟研究

本研究采用工程模拟软件对顺流双效精馏进行了模拟设计和优化,以乙醇-水物系为模型,对单塔精馏和二种顺流双效精馏进行模拟,在分离任务相同的情况下,考察进料组成、进料温度对各精馏流程的能耗的影响,与单塔精馏相比顺流双效精馏节能效果明显,达到了节能减排的目的。     

进料组成对双效精馏节能效果的影响

以乙醇-水为物系,通过模拟计算,研究了进料组成对平流双效精馏、顺流双效精馏和逆流双效精馏节能效果的影响。结果表明,平流双效精馏和逆流双效精馏的节能率随进料中易挥发组分质量分数的增加而增大,节能率均在40%以上。而顺流双效HGL精馏节能率随进料中易挥发组分质量分数的增加而略有降低,节能率近50%。因此,当进料中轻、重组分质量分数差不多,或轻组分质量分数较多时,选用平流双效精馏和逆流双效精馏节能效果较好,当进料中重组分质量分数较多时,顺流双效精馏节能效果较好。     

三效精馏节能规律研究及应用系统设计

用工程模拟软件PROII对不同条件下的各三效精馏流程进行优化模拟,研究进料温度、进料组成、进料相对挥发度对节能效率的影响.结果表明,三效精馏更适宜于进料相对挥发度小于6的物系,节能率可达50％以上,除逆流三效塔釜进料精馏适用于常温进料外,其余各流程均适用于泡点及以上温度进料,除顺流三效塔顶进料精馏外其余各流程均适用于进...     

三效精馏优化专家系统的设计

将三效精馏流程分为5类,研究了进料温度、进料组成、进料相对挥发度对节能效率的影响。结果表明:三效精馏更适宜于进料相对挥发度小于6的物系,节能率可达50%以上;除逆流三效塔釜进料精馏适用于常温进料外,其余各流程均适用于泡点及以上温度进料;除顺流三效塔顶进料精馏外,其余各流程均适用于进料中轻组分摩尔分数大于重组分摩尔分数的情况。进料温度对节能率的影响比进料相对挥发度和进料组成要显著,是关键的影响因素。根据三效精馏节能规律,设计了三效精馏优化专家系统,本系统由用户界面、知识库和推理机3部分组成,其开发基于Windows XP操作系统,以Visual Basic 6.0作为开发工具,实现推理机对知识库的访问,实现VB 6.0与工程模拟软件(PRO/Ⅱ)之间的数据传输,从而实现对最优流程的智能选择,为三效精馏的应用设计、流程选择提供了平台。     

1D, 2D and 3D Knitted Composite Reinforcements

Abstract

Knitted fabric properties are extremely variable. It allows to use them for many different purposes. One of the possibilities is the reinforcement of so called textile composites, which have already been widely used and very probably are going to be spread much more yet in the future. What are the possibilities of such knitted fabrics construction, including double layer and three dimensional products etc., is briefly described in this article.     

CFD simulations of bubble column reactors: 1D, 2D and 3D approach

CFD simulations have been carried out for the predictions of flow pattern in bubble column reactors using 1D, 2D and 3D k-ε models. An attempt has been made to develop a complete correspondence between the operation of a real column and the simulation. Attention has been focused on the cylindrical bubble columns because of their widespread applications in the industry. All the models showed good agreement with the experimental data for axial liquid velocity and the fractional gas hold-up profiles. However, as regards to eddy diffusivity, only the 3D model predictions agree closely with the experimental data.The CFD model has been extended for the estimation of an axial dispersion coefficient (D_L) using 1D, 2D and 3D models. Excellent agreement was found only between the experimental values and the 3D predictions. The 1D and 2D simulations, however, yielded D_L values, which were lower by 25-50%. For this, a mechanistic explanation has been provided.     

A comparative study of superhydrophobicity of 0D/1D/2D thermally functionalized carbon nanomaterials

Superhydrophobic coatings promise various practical applications. A one-step, ingenious yet economical thermal curing method is devised to render the carbon nanomaterials superhydrophobic. This study aims to compare the degree of superhydrophobicity of the carbon/polydimethylsiloxane (PDMS) synthesized from the 2D graphene nanoplatelets (GNPs), 1D multiwalled carbon nanotubes (MWCNTs), and 0D carbon black (CB) nanomaterials. The superhydrophobic GNPs/PDMS, MWCNTs/PDMS and CB/PDMS are synthesized when thermally functionalized with the siloxane groups. The Fourier transform infrared spectroscopy data signifies the successful functionalization of the carbon nanostructures by siloxane chains and the Raman spectroscopy analyses indicate that GNPs/PDMS manifests the highest degree of structural defects due to functionalization. The degree of superhydrophobicity induced on the carbon/PDMS coatings correlates with the dimensions of the carbon nanomaterials (0D, 1D and 2D), which is intimately associated with the effective surface areas of the nanomaterials susceptible of chemical functionalization. The promising applications of the superhydrophobic coatings are demonstrated. This study proposes a novel wettability tuning method and provides insightful analyses and characterization of the superhydrophobicity of the thermally functionalized carbon nanomaterials with different dimensions of varied nano-geometries.     

粉煤灰高性能混凝土一维/二维/三维碳化性能研究

通过粉煤灰高性能混凝土碳化依时深度试验,结合SEM、XRD等微观分析手段,研究了粉煤灰掺量、水胶比、养护龄期等因素对粉煤灰高性能混凝土一维、二维和三维碳化深度值的影响.结果 表明:混凝土抗碳化能力随粉煤灰用量和水胶比增加而降低;前期养护时间的延长有利于混凝土抵抗碳化反应.由于叠加效应,粉煤灰混凝土三维、二维碳化较一维碳化更为严重,同试验周期下碳化深度值升高1.39～ 2.88倍.     

D-青霉胺的制备

采用青霉素GK和苯肼或2，4-二硝基苯肼为原料，以水为溶剂，在氮气流保护下，加热回流，使用乙醇处理后制备青霉胺，将青霉胺粗品使用N，N-二甲基甲酰胺为重结晶溶剂重结晶，得到精品青霉胺，收率为75％-85％，产品质量达到中国药典2000版的标准。     

D and D/He plasma interactions with diamond: Surface modification and D retention

Chemical vapour deposition (CVD) diamond is of interest as a plasma facing material in magnetically confined nuclear fusion devices. CVD diamond samples were exposed to ion fluences between 1.5 × 10²² ions m^− 2 and 1 × 10²⁴ ions m^− 2 in D, D/He and He plasmas. A significant surface coverage of 10 nm–100 nm sized hemispherical and conical surface features resulted from chemical erosion and subsequent redeposition on samples exposed to ≥ 10²³ ions m^− 2 when exposed to D containing plasmas. Near edge X-ray absorption fine structure (NEXAFS) spectra showed strong diamond features following plasma exposure, indicating that the diamond crystal structure on the surface was largely retained. A small increase in the sp² fraction (from 1.2% to 4–7%), was observed suggesting some amorphous carbon formation. Elastic recoil detection analysis (ERDA) revealed that D retention saturates at ~ 5.4% averaged over the depth resolution of 20 nm from the surface, for an ion fluence of ~ 10²³ ions m^− 2. The addition of He to the plasma resulted in a slower uptake of D, which was attributed to He ion induced desorption of D.     

三维编织技术及管状三维编织物的编织

本文简要介绍了三维（３Ｄ）编织技术的发展情况、特点和３Ｄ编织物的性能，也介绍了管状３Ｄ编织物的编织过程。     

二维与三维机织复合材料的力学性能实验研究

通过对超厚三维正交机织复合材料及二维机织层合板分别进行拉伸和压缩实验，研究比较两复合材料刚度和强度特性的差异；研究发现无论是三维机织材料的拉、压，还是二维层合板的拉、压的应力一应变曲线都可近似为直线关系，而且具有脆性破坏的特点；三维复合材料的拉、压强度要高于二维层合板，是由于不同的增强相结构及纤维含量造成；不同的破坏模式对材料强度影响很大。     

From 1D chain to 2D layer and 3D network: Solvent-free syntheses of new metal oxalates

Four metal oxalates, Hdpa⋅Cr(ox)₂ (1), (Hdpa)₂⋅ Zn₂(ox)₃ ⋅ 2H₂O (2), Zn(H₂O)(ox) (3), and (Hgua)(H₃O) ⋅ Cd(C₂O₄)₂ (4), have been synthesized under solvent-free conditions, where dpa = diisopropylamine, ox = oxalate, and gua = guanidine. These compounds have extended structures varying from 1D chain (for 1), to 2D layer (for 2 and 3), and 3D framework network (for 4). The temperature dependence of the magnetic susceptibility of compound 1 indicates the existence of antiferromagnetic interactions between the chromium ions. Upon excitation at 230 nm, compound 3 exhibits an extensive luminescence with a peak centered at 501 nm.