NUCLEAR HYDROGEN DEVERLOPMENT AND DEMONSTRATION PROGRAM IN KOREA

The Korea Atomic Energy Research Institute (KAERI) launched a nuclear hydrogen program to develop and demonstrate a hydrogen mass production system by 2019. The key feature of the system is to produce the hydrogen from water using nuclear power. No fossil fuel (energy) will be used and no greenhouse gas will be emitted. The high temperature gas-cooled reactor (HTGR), which has high safety characteristics with competitive economy, is being developed to provide a high temperature heat (about 1000℃) required to produce hydrogen from water. A decision will be made on the reactor specifications after the pre-conceptual design works. Both thermo-chemical process and high temperature electrolysis are to he used for the production of hydrogen from water using nuclear heat. The production of hydrogen from water by nuclear power is one of the most viable options for the mass production of the hydrogen using non-fossil fuels. In 2020s, the nuclear based hydrogen is planned to provide about 20% of total energy consumed in the transportation of Korea. The nuclear hydrogen is expected to make a considerable contribution to the national energy security of Korea.     

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.     

面向可持续发展的半导体制造的集成产品和过程控制

Semiconductor fabrication is a manufacturing sequence with hundreds of sophisticated unit operations and it is always challenged by strategy development for ensuring the yield of defect-free products. In this paper, an advanced control strategy through integrating product and process control is established. The proposed multiscale scheme contains three layers for coordinated equipment control, process control and product quality control. In the upper layer, online control performance assessment is applied to reduce the quality variation and maximize the overall product performance (OPP). It serves as supervisory control to update the recipe of the process controller in the middle layer. The process controller is designed as an exponentially weighted moving average (EWMA) run-to-run controller to reject disturbances, such as process shift, drift and tool worn out, that are exerted to the op-eration. The equipment in the process is individually controlled to maintain its optimal operational status and maximize the overall equipment effectiveness (OEE), based on the set point given by the process controller. The ef-ficacy of the proposed integrated control scheme is demonstrated through case studies, where both the OPP (for product) and the OEE (for equipment) are enhanced.     

Selective propylene epoxidation in liquid phase using highly dispersed Nb catalysts incorporated in mesoporous silicates

Selective propylene epoxidation to propylene oxide(PO) with hydrogen peroxide(H_2O_2) was carried out in a catalytic semi-batch reactor.High propylene epoxidation activity(44 h~(-1)) was observed over Nb based mesoporous silicate materials Nb-TUD-1 under mild operating conditions.The physical and chemical properties of the Nb based silicates characterized using BET,FTIR,TPD,TEM and UV–Vis revealed that the site isolation and surface acidity are crucial for PO production.Catalyst synthesis methods were investigated for their effects on PO productivity,PO selectivity and H_2O_2 utilization efficiency.It is found that Nb-TUD-1 material synthesized by the sol–gel method is more active and selective than impregnated materials for liquid phase propylene epoxidation.Surface characterization confirms that thus synthesized Nb-TUD-1 catalysts have more Lewis acidity and less Bronsted acidity compared to the catalysts by impregnation.     

ABSTRACTS

Design Summary for 10 kt/a Acid Production from Phosphorus Mud
Abstract： For the fact that there is large amount of by-product phosphorus mud from electric furnace phosphorus production in China, and problems of low phosphorus recovery and secondary pollution in many ways for recovery for element phosphorus in it, and based on the actual design of a 10 kt/a acid production plant from phosphorus mud of a yellow phosphorus production enterprise, the process flow, control system, equipment selection and technical features of acid production from phosphorus mud are introduced. The process offers features like high phosphorus recovery, free of secondary pollution, high level of automation, and the ability for continuous production, which is worth of promotion.     

废物最小化的过程集成方法及多目标优化

By avoiding or reducing the production of waste, waste minimization is an effective approach to solve the pollution problem in chemical industry. Process integration supported by multi-objective optimization provides a framework for process design or process retrofit by simultaneously optimizing on the aspects of environment and economics. Multi-objective genetic algorithm is applied in this area as the solution approach for the multi-objective optimization problem.     

Simulation of hydrocarbons pyrolysis in a fast-mixing reactor

Currently, thermal decomposition of hydrocarbons for the production of basic petrochemicals (ethylene, propyl-ene) is carried out in steam-cracking processes. Aside from the conventional method, under consideration are alternative ways purposed for process intensification. In the context of these activities, the method of high-temperature pyrolysis of hydrocarbons in a heat-carrier flow is studied, which differs from previous ones and is based on the ability of an ultra-short time of feedstock/heat-carrier mixing. This enables to study the pyrolysis process at high temperature (up to 1500 K) at the reactor inlet. A set of model experiments is conducted on the lab scale facility. Liquefied petroleum gas (LPG) and naphtha are used as a feedstock. The detailed data are obtain-ed on temperature and product distributions within a wide range of the residence time. A theoretical model based on the detailed kinetics of the process is developed, too. The effect of governing parameters on the pyrolysis process is analyzed by the results of the simulation and experiments. In particular, the optimal temperature is detected which corresponds to the maximum ethylene yield. Product yields in our experiments are compared with the similar ones in the conventional pyrolysis method. In both cases (LPG and naphtha), ethylene selectivity in the fast-mixing reactor is substantial y higher than in current technology.     

Fenton氧化法处理填埋渗滤液

Central composite design (CCD), the most popular design of response surface methodology (RSM), was employed to investigate the effect of total organic carbon (TOC) ratio of high molecular weight organic matter (HMW) to low molecular weight organic matter (LMW), the LMW strength and molar ratio of hydrogen peroxide to ferrous ion on landfill leachate treatment by Fention process. Based on the experimental data, a response surface quadratic model in terms of actual factors was obtained through analysis of variance (ANOVA). The model showed that TOC removal increased with the increase of HMW to LMW ratio and the decrease of LMW strength. There existed an optimal hydrogen peroxide to ferrous ion molar ratio for TOC removal.     

超临界水中添加过氧化苯甲酰对聚丙烯降解的促进作用

The effect of benzoyl peroxide （BPO） on polypropylene （PP） degradation in supercritical water was investigated with the aim of developing a process for recycling of waste plastics. A series of experiments with and without BPO were carried out at temperatures of 653 K and 673 K under pressure about 26 MPa for 30, 75 and 120 min respectively. Products were analyzed by an Ostward-type viscometer, gas chromatography and spectrometry （GC/MS） etc. The results indicated that mean molecular weight of the samples decreased greatly along with the time elapsing or with the temperature increasing, and PP was decomposed to Miphatic and cycloparaftinic hydrocarbons but a few benzenoid hydrocarbons. By comparing the experiments with and without BPO, it was made clear that BPO is an effective additive on PP degradation in supercritical water.     

Bioorganic Municipal Waste Management to Deploy a Sustainable Solid Waste Disposal Practice in China

The utilization of bioorganic municipal waste (BMW) is considered essentially for the further development of integrated waste management practice in China. Awareness and knowledge about the importance of BMW management and source separation of waste on household level, as a precondition for the implementation of an economically feasible integrated waste management infrastructure, were developed in Europe during the last decade. The Sino-German RRU-BMW Project is facilitating applied research investigations in 4 pilot areas in Shenyang to assess the population's behavior to develop the design criteria for appropriate process technologies and to provide the basis to adopt BMW management policy in China.     

催化剂对制备二氧化氯的动力学数据的影响

为设计出合适的反应器,在加入催化剂和未加催化剂的条件下对过氧化氢法制备二氧化氯的各种反应物进行了动力学研究。研究表明,加入催化剂后反应速率变快;温度升高反应速率升高;在一定的浓度范围内,硫酸、双氧水、氯酸钠的浓度变高,反应速率变大。反应物的反应级数都比较小,活化能比较低,反应较容易进行。     

环境友好氧化消毒剂二氧化氯发生技术的进展

介绍了以亚氯酸盐、氯酸盐为主要原料的二氧化氯发生技术的进展 ,重点评述以氯离子、甲醇或过氧化氢为还原剂的氯酸盐工艺。指出以过氧化氢为还原剂的二氧化氯发生方法可以从源头上减少氯气和酸性芒硝的生成 ,建议国内企业和科研机构尽快开发出具有知识产权的特色二氧化氯发生技术 ,同时制定有关二氧化氯纯度和发生器等相关标准     

纸浆绿色漂白——二氧化氯漂白

二氧化氯是ECF漂白工艺的主要漂白剂之一,已被应用于制浆厂的多段漂白。生产实践表明,在相同有效氯用量下,二氧化氯漂白产生的可吸附有机卤化物(AOX)仅为氯气漂白的1/5,而不影响脱木素。二氧化氯具有强氧化性,较强的脱木素能力和脱木素选择性。在ClO2漂白过程中,缓冲体系的建立有利于维持pH的稳定,二甲基亚砜(DMSO)、H2O2、NaClO2等一些助剂减少了ClO2漂白过程中AOX的生成量。ClO2生产设备国有化、采用灵活多变的漂白工艺是今后发展的趋势。     

Mechanism of the ClO2 generation from the H2O2‐HClO3 reaction

The development of chlorine containing species during the hydrogen peroxide‐based chlorine dioxide generation process has been determined. Accordingly, two distinct phases, namely the induction period and the steady‐state phase, were identified. In the induction period, it was observed that chloride and chlorous acid are generated, while chlorine, a byproduct from some methanol‐based processes, is not detectable. The absence of chlorine is explained by the fast reaction kinetics between hydrogen peroxide and chlorine, which results in the formation of chloride. In the steady‐state phase, due to the accumulation of chloride and chlorous acid during the induction period, the reaction between chloric acid and chlorous acid, which is responsible for the generation of chlorine dioxide in the hydrogen peroxide‐based ClO₂ process, becomes possible. Chloride is a catalyst in such a reaction.     

高纯二氧化氯二次供水消毒系统的应用

纯度和使用成本限制了二氧化氯的应用,在DTJ-HP法高效、高纯稳定二氧化氯溶液生产技术基础上研制的高纯二氧化氯二次供水消毒系统很好的解决了这个问题,该装置以氯酸钠、双氧水、硫酸为主要原料,通过PLC可编程控制系统,实现了运行成本低、性能稳定、无泄漏、安全可靠。根据发生器的额定消耗量计,投加量为0.1~0.3 mg/L的浓度下,水质达标,每吨水消毒成本仅为0.002~0.005元。     

二氧化氯发生器在二次供水消毒系统中的应用

纯度和使用成本限制了二氧化氯的应用,在DTJ-HP法高效、高纯稳定二氧化氯溶液生产技术基础上研制的高纯二氧化氯二次供水消毒系统很好地解决了这个问题,该装置以氯酸钠,双氧水,硫酸为主要原料,通过PLC可编程控制系统实现了运行成本低、性能稳定、无泄漏、安全可靠.根据发生器的额定消耗量计,投加质量浓度为0.1～0.3 mg/L条件下,水质达标,每吨水消毒成本仅为0.003～0.005元.     

Mechanism and kinetics of chlorine dioxide reaction with hydrogen peroxide under acidic conditions

The reaction of chlorine dioxide with hydrogen peroxide was studied in a well stirred batch reactor in a pH range of 3.60 to 5.07, which is of interest for commercial chlorine dioxide bleaching of chemical pulp. The reaction rate was determined by following the consumption of chlorine dioxide and hydrogen peroxide and the formation of chlorite. The rate equation was established. It was found that the concentration dependencies of chlorine dioxide, hydrogen peroxide and hydroxide ion were all first-order. A reaction mechanism compatible with the rate equation was proposed. Since it was found in previous work that chlorite in chlorine dioxide solution by the addition of small amount of hydrogen peroxide potentially led to a decrease in the formation of organically bound chlorine during chlorine dioxide bleaching, two methods were suggested to implement this technique in a bleach plant.     

An Eco-Benign Approach for Unhairing Goat Skin Using Ozone

Unhairing or hair removal is an important step in leather processing. The conventional lime-sulfide process used for unhairing operation generates considerable waste and toxic hydrogen sulfide in the effluent when mixed with acidic effluent. Oxidative chemicals offer an alternative to the use of sodium sulfide in a rapid unhairing reaction. Oxidative unhairing was investigated using hydrogen peroxide, chlorine dioxide, and calcium peroxide, with unsatisfactory results. Ozone being a good oxidative agent was tried in this work in unhairing goat skin. Experiments on the use of ozone with oxygen/air as feed gas were carried out to study the unhairing effect on different regions of a goat skin. Unhairing was done in a static reactor. The wet blue produced from the skin underwent physical testing and was compared with the conventional operation. COD of the spent liquors were tested for comparison. The experimental results indicate that ozone as an oxidative agent could be used for depilation without affecting the physical and chemical characteristics of the resulting leather. The use of ozone for unhairing operation in place of sodium sulfide results in hair recovery and reduction of pollution loads.     

The final bleaching of eucalypt kraft pulps with hydrogen peroxide: relationship with industrial ECF bleaching history and cellulose degradation

BACKGROUND: The process of chemical pulp bleaching is based for the most part in chlorine dioxide within elemental chlorine free (ECF) technologies. The use of greener alternatives such as bleaching with hydrogen peroxide (P stage) is not widely used owing to selectivity concerns related to transition metal‐catalyzed decomposition reactions. Even at the final stage where peroxide is recognized to boost brightness and improve the brightness stability of the bleached pulp, cellulose degradation often overcomes these advantages. This paper presents the results of studies intended to optimize final peroxide bleaching performance considering two standard ECF industrial bleaching sequences: the conventional DED and the ECF‐light OQ(PO)D (stages name: D—chlorine dioxide; E—alkaline extraction; O—oxygen; Q—chelation, (PO)—hydrogen peroxide pressurized with oxygen). RESULTS: The addition of sodium diethylenetriaminepentaacetate (DTPA) was the most effective option in terms of DED pulp bleachability and selectivity with hydrogen peroxide, as well as in terms of brightness reversion. As regards the OQ(PO)D pulp, a blend of DTPA and magnesium was the most beneficial in those properties. CONCLUSIONS: The choice of the best hydrogen peroxide stabilizer, among the different tested combinations of magnesium and chelants (EDTA and DTPA) studied, in terms of pulp bleachability, bleaching selectivity and brightness reversion is dependent on the impact of the previous bleaching stages on metallic nature and content. The pulp Mg/(Fe + Cu) ratio was highlighted as a process parameter controlling cellulose degradation in peroxide bleaching. Copyright © 2010 Society of Chemical Industry     

用氯水治理亚磷酸三甲酯废水

阐述了利用氯氧化特性，将氯氢处理过程中产生的氯水用于处理亚磷酸三甲酯废水，使废水中的COD值及胺含量大大降低的氧化机理及工艺过程。