Single electrode heat of molten NaCl electrolysis: measurement by electrolytic calorimeter and heat flux transducer (HFT)

An electrolytic calorimeter employing a heat flux transducer (HFT) has been developed. By means of this apparatus the single electrode Peltier heat for the anodic chlorine evolution reaction in the electrolysis of molten NaCl-ZnCl₂ using a-alumina diaphragm was measured. The value of the single electrode Peltier heat obtained by such a method was 0.697 J C^–1 at 377° C, which is very close to the value 0.614 J C^–1 previously determined by a thermoelectric power measurement. The coincidence between the two methods indicates that a thermoelectric power measurement is quite valid for determining the single electrode Peltier heat.     

水电解电极材料

叙述了国内外水电解的生产、研究及发展趋势 ,分析了目前影响水电解生产的关键因素 ,提出了阴极和阳极材料的选择和加工方法 ,以降低氢氧过电位 ,使电解槽槽电压在 1.7～ 1.8V之间 ,能耗在 3.7～3.9kW·h/ (m3 H2 ) (2 0℃ )之间 ,提高我国水电解的生产水平     

AZF工艺水热平衡分析

由于AZF复合肥生产工艺（管式反应器喷浆造粒工艺）的产业链短,所用原料价格居高不下,成本高,使得该类工艺的装置开车率较低。为配合AZF工艺装置的技改,对AZF工艺全系统及造粒、干燥、洗涤等关键部分进行了水、热平衡的计算分析,为技改提供一条可行的分析思路和方法：     

离子膜电解技术在废水处理中的应用研究进展

离子膜电解是电渗析和电解结合的具有综合功能特性的技术,近年来在废水处理方面的应用逐渐兴起.根据离子膜电解技术在污染治理中已取得的成果,对离子膜电解技术处理废水的原理及应用现状进行了综述,并对其存在问题及今后发展方向作了一定的探索.     

电解节能技术的应用

分析电解生产能耗的主要影响因素,介绍天津大沽化工股份有限公司离子膜法烧碱和隔膜法烧碱的节能技术,包括:活性阴极技术、改性隔膜技术和扩张阳极技术,着重推荐了零极距单元槽。     

An application of Durbin-Watson statistics to electrochemical science

Durbin-Watson statistics provide a means of determining whether adjacent/consecutive residuals related to a simple first-order regression are mutually interdependent, i.e. whether the postulated number of independent variables is sufficient for the sake of modeling. This paper shows three specific applications to linear models fitting electrochemical data.     

回收电解余热 实现全卤制碱

通过对电解反应释放余热的衡算,确定了合理利用余热能达到的最终用卤量;利用新型脱氯塔及配套的二次脱氯工艺,脱除淡盐水中多余的水分,实现全卤制碱;采用新的芒硝脱水法,解决了制约高芒卤水制碱的技术瓶颈。     

离子膜电解装置中低位热能的回收利用

通过热量交换和换热面积的计算．说明了通过加热过滤盐水来回收湿氯气或脱氯淡盐水的低位热能是可行的。同峙指出了这2种低位热能回收利用的优、缺点。指出了离子膜电解槽生产的湿氯气在进行热量交换计算时,与隔膜法电解产生的湿氯气的区别是要分为显热段和潜热段来进行计算。     

氯酸钠电化生产的歧化反应热计算

电解氯化钠制氯酸钠的过程会产生歧化反应热,歧化反应热的多少关系到移走这部分热量的换热器设计和这部分热能的开发利用价值.但由于氯酸钠电化生产过程能量衡算复杂(既有电功、又有化学反应热效应、相变热),一般化工设计类书籍中,很难找到这类反应的能量衡算方法.对氯酸钠电解歧化反应热的理论计算和实际测算方法进行了探讨,给出了合理、简便的理论计算和实际测算方法.并且两种方法计算结果相差较小.然后利用已有的实际生产数据进行了佐证,最后综合计算结果和已有生产数据,得出电解电能30%～35%转化为可利用的歧化反应热,以氯酸钠产量计歧化反应热为5.55×106～6.34×106 kJ/t的结论.数据可靠性满足设计开发者使用.     

Simulation of polydisperse multiphase systems using population balances and example application to bubbly flows

In this work the relationship between multiphase computational fluid dynamics models and population balance models is illustrated by deriving the main governing equations from the generalized population balance equation. The resulting set of equations, consisting of the well known two-fluid model coupled with a bivariate population balance model, is then implemented in the CFD code OpenFOAM. The implementation is used to simulate a particular multiphase problem: bubbly flow in a rectangular column. Results show that, although the different mesoscale models for drag force, coalescence, breakup and mass transfer, can be improved, the agreement with experiments is nevertheless good. Moreover, although the problem investigated is quite complex, as the evolution of bubbles is solved in real-space, time and phase-space (i.e. bubble size and composition) the resulting computational costs are reasonable. This is due to the fact that the bivariate population balance model is solved here with the so-called conditional quadrature method of moments, that very efficiently deals with these problems. The overall approach is demonstrated to be efficient and robust and is therefore suitable for the simulation of many polydisperse multiphase flows.     

钛涂铂电极在电解功能水机中的应用研究

钛涂铂电极是近年来活跃应用在电解功能水机中的一种新型电极材料。本文介绍了钛涂铂电极制造的工艺条件,用扫描电镜对钛涂铂电极表面形貌进行了表征。采用电化学工作站,在三电极体系中测试了钛涂铂电极析氧极化曲线及循环伏安曲线。测试数据表明,在水电解中,钛涂铂电极析氧活性高于钛镀铂电极。     

内电解法处理印染废水的效果研究与分析

印染废水成分复杂、色度高、CODCr高且难降解,对环境造成较大污染。印染废水处理一般采用生化一混凝沉淀法、混凝气浮法、化学氧化及活性炭吸附法等,但这些方法存在运行费用较高、不易管理等缺点。内电解的基本原理是利用铁屑中的铁和炭组分构成微小原电池的正极和负极,以充入的废水为电解质溶液,发生氧化-还原反应,形成原电池。利用内电解对印染废水进行预处理,脱色率可达75％。90％,CODCr去除率达55％左右。另外还可提高废水的可生化性,废水的BOD5/CODCr值从原来的0.23提高到0．57,为后续生化处理和处理后达标排放奠定了基础,且运行成本低,易于管理。     

Use of electrochemical techniques to study natural convection heat and mass transfer

This paper is specifically concerned with the application of the electrochemical limiting current technique to the study of mass transfer and heat transfer by natural convection. A variety of geometrics are considered including upward facing discs, inclined plates, cones, cylinders, cuboids and cavities. The case of natural convection due to simultaneous concentration and thermal effects is also considered. A particular feature of the work described is the use of Schlieren photography to obtain flow pattern information. This allows the mass/heat transfer behaviour to be better understood in the light of hydrodynamic observations.This paper was presented at the Workshop on Electrodiffusion Flow Diagnostics, CHISA, Prague, August 1990.     

An application of nonparametric censored-data analysis to certain electrochemical observations

If a physical component or a device, employed in a process fails at a certain time instant T⁺, but due to an event unrelated to the evolution of the process, or its mechanism, the observed survival time is called censored. Since the true survival time T might have been found to be any time instant T > T⁺, had the process-independent event not occurred, analysis is different from purely uncensored-data analysis. The subject matter is numerically treated for an electrochemical system by estimating its survival function, and by two-sample observation sets of cathode failure in comparing tank-flow to tubular-flow electrolyzer performance.     

Investigation of 304L stainless steel in a NaCl solution using a microcapillary electrochemical droplet cell: Comparison with conventional electrochemical techniques

In this work a comparison has been made between a localized (micro scale) and a conventional (large-scale) corrosion study of 304L stainless steel in a sodium chloride solution using Tafel plots and electrochemical impedance spectra. Results show the high ability of microelectrochemical techniques for the local investigation of corrosion procedures on solid surfaces, something which is not feasible with conventional large-scale techniques. In the second experiment the microelectrochemical behavior of a faulty copper layer on 304L stainless steel was investigated using linear sweep voltammetry. Glass capillaries touching only small areas of the surface were used and the copper coated surface of the steel sample was scanned in a 9 by 6 matrix (54 measurements) while acquiring data. The obtained corrosion potentials for both defect and intact areas were used to map the surface. The surface plot shows the exact position of the defect point in the coating layer.     

Material properties of cation exchange membranes for chloralkali electrolysis,water electrolysis and fuel cells

Owing to the development of perfluorinated ion-exchange membranes, the application of the membranes in electrochemical cells has advanced greatly, especially in chloralkali electrolysis. Material properties of perfluorinated carboxylate membranes used for chloralkali electrolysis are described in relation to the conditions of their use. Some new membranes for water electrolysis and fuel cells are briefly described.Paper presented at the meeting on Materials Problems and Material Sciences in Electrochemical Engineering Practice organised by the Working Party on Electrochemical Engineering of the European Federation of Chemical Engineers held at Maastricht, The Netherlands. September 17th and 18th 1987.     

Reaction pathways in the electrochemical degradation of thiocarbamate herbicides in NaCl solution

We have identified the intermediates and end products which are formed during the electrolytic degradation of thiocarbamate pesticides in aqueous NaCl solutions and investigated how the intermediate and end product volumes and ratios depend on reaction conditions. Further, we have defined both the reaction pathways leading to intermediate and end product formation and the methods affecting this process. The degradation of the molecular part containing the N atom is accounted for, as are the listed reactions and reaction pathways that affect degradation. If pH is changed, the ratio of degradation products NO ₃ ⁻ and N₂ can be influenced in favour of N₂ gas. This pH change can then be produced without additional material by changing the construction of an electroflotation cell. To implement degradation, “flotation electrolysis” has been found to be an effective method as it facilitates a regulated pH-shift, foam handling and gas bubble rising velocity. The efficiency of the method can be further enhanced by UV photolysis.