氢同位素液相催化交换技术进展

简要介绍了核反应堆中含氚水进行氢同位素液相催化交换技术的原理,系统性分析介绍了联合电解催化交换(CECE)工艺技术流程、电解单元富集重组分原理及催化性能评价方法,同时对目前国内外正在研究探索的双温催化交换技术研究进行了描述和进展介绍。     

空气-水界面氧化物薄膜研究现状及展望

介绍了一种新型的无机纳米薄膜——空气-水界面氧化物薄膜。用表面活性剂为模板,在特殊区位空气-水界面自组装纳米无机薄膜,已成为一个重要研究课题。在应用基础研究方面,建立了高分子稳定空气-水界面无机薄膜模型,来更系统的理解这些无机薄膜的物理、化学性质。采用了X射线衍射、透射电子显微镜等一系列分析手段,对这种薄膜样品的结构、性质、机理等诸多方面进行了研究。     

以太网交换技术现状及展望

介绍交换式以太网的常用技术。交换机是以太网中的关键设备，它分析到来的帧、生成和维护地址表、存储转发帧。交换机采用专门器件ASIC结构，生成树、VLAN和第三层交换等技术加强了其功能。建立对信息流实施优先级控制、高度容错、自动管理的智能型安全网络，是交换式以太网的发展方向。     

氢燃料电池质子交换膜研究现状及展望

使用氢燃料电池能够有效解决汽车的碳排放问题,而质子交换膜是其中最为核心的原材料之一.目前氢燃料电池质子交换膜的研究主要集中在降低成本、提升寿命、改善环境耐受性等方面,重点关注膜的机械强度、质子电导率、热稳定性和化学稳定性等核心性能指标.基于氢燃料电池质子交换膜现有基础研究和产业化研究现状,从聚合物基体的选择及改性方式、...     

高温氢-水蒸汽相催化交换研究

蒸汽相催化交换是水去氚化的一项经典技术,通常反应温度为200℃。本文开展了200℃以上的高温蒸汽相催化交换实验研究,包括填充材料对比测试、不同温度下的交换平衡常数测定以及不同工艺条件下的催化交换实验;结果表明,泡沫镍适合用作高温催化交换反应的填料,交换平衡常数在200～500℃间随着温度升高不断增大,气/水比增大会导致氢和水中氘浓度都降低,泡沫镍填料在300℃、气/水比1∶1条件下的催化交换反应的空速为380h~(-1);本研究可为蒸汽相催化交换水降氚的工程设计提供有益参考。     

氢同位素气相色谱分析研究现状与展望

氢同位素气体分析在氚处理工艺及聚变堆燃料循环系统中有着非常重要的应用.由于同位素具有相同的化学性质,其分析只能利用其物理性质的微小差别来实现,带有低温分离柱的气相色谱仪是分析氢同位素的重要方法之一,而近年来在研究应用方面取得重要进展的微气相色谱有望大幅缩短分析时间,实现在线分析,具有潜在的重要应用前景.本文阐述了气相色...     

煤催化气化催化剂发展现状及研究展望

煤与气化剂(如水蒸气、CO2、H2和O2)之间的气化反应最有效的催化剂主要为碱金属、碱土金属以及过渡金属的盐类,根据其组成,详细论述了煤催化气化催化剂的特性。据研究,在气化反应中碱金属催化剂如Na、K等易与煤中矿物质如Si或Al反应致使催化剂失活,同时过渡金属易被煤中S毒化,这在一定程度上制约了煤催化气化工业化进程。论述了煤催化气化催化剂的研究方向,认为开发新型高效、低廉且易回收催化剂是有必要的。     

用于氢同位素交换的一种高分子催化剂

<正> 氘是核聚变的主要燃料,氘的氧化物——重水是反应堆中最有效的中子减速剂(高速中子通过与减速剂原子的原子核反复碰撞而失去能量)和传热介质。目前制取重水较好的方法是高分子负载铂催化的氢-水(液)交换法。由于所用的催化剂是疏水的,因而在低温(接近常温)下用于氢-水(液)交换反应不会失活,并具有分离系数大、氘提取率高、无毒、无腐蚀和操作费用低等优点。这种疏水性的高分子负载铂催化剂,尚可用于从重水中回收氚。     

丙烷催化脱氢制丙烯现状及展望

1 前言丙烯,作为基本有机化工原料,其经济价值为众所周知。一般来讲,目前丙烯主要靠乙烯装置副产或FCC气体回收。随着石油化学工业的发展,丙烯愈加供不应求。为了扩大丙烯的来源,一些工业化国家研究开发了丙烷催化脱氢制丙烯技术。我国有着较为丰富的丙烷资源,     

非晶态钴-铁合金水氧化催化研究

可再生电力驱动的催化水裂解为生产氢和氧分子提供了一种很有前途的策略,但其效率受到阳极析氧反应动力学缓慢的严重限制。非晶态催化剂表现出良好的析氧活性,非晶结构的短程有序结构能增加活性位点的数量,从而提高了非晶催化剂在析氧反应中的电催化活性,但对其潜在来源知之甚少,这阻碍了高性能非晶态析氧反应催化剂的发展。在此,我们通过一种简单手段来制备用于析氧反应的无定形钴-铁合金催化剂,同时研究了不同金属比例对非晶催化剂性能的影响。优化制备的Co0.25Fe0.75催化剂在1.0 M KOH溶液中20 mA·cm-2电流密度下的析氧过电位仅为314 mV,而且具有20 h的长期电解稳定性。     

智能分注技术发展现状与应用前景

我国水驱油田已经进入了高含水开发期,国内分层注水工艺进入了智能测调时代。以"桥式偏心+钢管电缆直读测调"为主体的智能化分层注水技术,在油田注水中已得到大规模推广应用,大幅提高了注水井测调效率,缩短了测调时间。但是,目前的分层注水工艺技术水平仍然面临较多的问题:测调周期逐年缩短、层间矛盾加剧、无法进行油藏模拟等,为了进一步满足生产要求,有必要发展智能化分层注水技术,扩大注入水的波及体积,提高注水驱油效率,实现对注水层的精细控水。在当前或未来的国内油田生产中会逐步进行推广应用。分层注水工艺将继续会以实现多油层高效注水为目标,融合大数据处理与人工智能技术,向一体化、智能化、高效化方向发展,为油田稳产、增产提供技术保障。     

稳定同位素的分离与应用

介绍了国内外稳定同位素的发展以及Ｄ，＾１３Ｃ，＾１５Ｎ，＾１８Ｏ等稳定同位素的分离，并对标记化合物的生产和应用作了概述。     

Separation of Uranium Isotopes by the Chemical Exchange Method

Abstract

The basic chemical process and technology for producing 3-5% enriched uranium has been established, through advances which allowed increases in the electron-exchange and adsorption-desorption reaction rates, effective uranium adsorption band formation and maintenance, reduction of the mobile-phase dispersion, and reduction in the height of the separation unit, which is largely determined by the diffusion coefficient, the electron exchange reaction rate of uranium ions, and the non-uniform flow pattern in the adsorption band. Physical theory and experimental results show the attainment of a specific separation power of approximately 500 SWU/m³·yr for the process, and the possibility of an enrichment cost of $41/SWU in its commercial-scale application as calculated with depreciation terms of 15 years for equipment and 45 years for buildings and interest payments at 8% on investment capital. Inherent advantages of the process, in addition to low enrichment cost, are simple, stable operation and facilitation of the nuclear fuel cycle, with efficient separation of uranium-235 from the other uranium isotopes of spent nuclear fuel and elimination of the need for UF₆ conversion.     

Separation of Gallium and Indium Isotopes by Cation and Anion Exchange Chromatography

Ion exchange chromatography was applied to study chemical isotope effects of gallium and indium in ligand exchange reactions. A strongly acidic cation and a strongly basic anion exchange resin were used as a solid phase, and aqueous HCl as a liquid phase. On the cation exchanger, the light isotope ⁶⁹Ga was enriched at the front part of the elution band and the heavy isotope ⁷¹Ga at the end part. Instead, the light ¹¹³In isotope was enriched at the end part, and the heavy isotope ¹¹⁵In at the front part. The isotope separation factor ? is equal to 3.3?×?10^–5 for gallium and 2.0?×?10^–4 for indium. On the anion exchanger, the heavy gallium isotope was enriched at the front part, whereas the heavy indium isotope at the end part of the band, with ? equal to ～10^–3 and 1.7?×?10^–4, respectively. This pattern of enrichment is caused by stronger Ga³⁺–OH₂ than Ga³⁺–Cl^? bond, and by inverse order of bond strength for indium. In the displacement method, gallium and indium on anion exchanger also show opposite enrichment of their isotopes, but the ? values (1.5?×?10^–2 for gallium and 5?×?10^–3 for indium) are greater than those found in the elution method, probably due to much higher concentrations of the metals.     

Hydrogen Isotope Separation by Catalyzed Exchange Between Hydrogen and Liquid Water

Abstract

The discovery, at Chalk River Nuclear Laboratories, of a simple method of wetproofing platinum catalysts so that they retain their activity in liquid water stimulated a concentrated research program for the development of catalysts for the hydrogen-water isotopic exchange reaction. This paper reviews 10 years of study which have resulted in the development of highly active platinum catalysts which remain effective in water for periods greater than a year.

The most efficient way to use these catalysts for the separation of hydrogen isotopes is in a trickle bed reactor which effects a continuous separation. The catalyst is packed in a column with hydrogen and water flowing countercurrently through the bed. The overall isotope transfer rate measured for the exchange reaction is influenced by various parameters, such as hydrogen and water flow rates, temperature, hydrogen pressure, and platinum metal loading. The effect of these parameters as well as the improved performance obtained by diluting the hydrophobic catalyst with inert hydrophilic packing are discussed.

The hydrophobic catalysts can be effectively used in a variety of applications of particular interest in the nuclear industry. A Combined Electrolysis Catalytic Exchange - Heavy Water Process (CECE-HWP) is being developed at Chalk River with the ultimate aim of producing parasitic heavy water from electrolytic hydrogen streams. Other more immediate applications include the final enrichment of heavy water and the extraction of tritium from light and heavy water. Pilot plant studies on these latter processes are currently in progress.     

Improved Donors for the Separation of the Boron Isotopes by Gas-Liquid Exchange Reactions

Abstract

Chemical exchange between gaseous boron trifluoride (BF₃) and the liquid BF₃·dimethyl ether complex has been used extensively for the commercial fractionation of boron isotopes. Several compounds never before studied as donors in the isotope exchange reaction were examined to determine if they were viable replacements for the dimethyl ether system. For the first time, ketones were studied as donors in the boron isotope exchange reaction. The ketones examined were acetone, methyl isobutyl ketone, and diisobutyl ketone. The ideal single stage separation factors, α, measured for these ketones were between 1.038 and 1.043 at 30°C. The observed separation factor for a fourth donor system, nitromethane, was 1.067 at 30°C, well above that predicted by theory or observed for any known BF₃/donor system. For each of the systems studied, the separation factors were greater than the value of α = 1.027 reported for the dimethyl ether/BF₃ system at 30°C. In view of the experimentally observed separation factors, these donor systems are potential replacements for dimethyl ether in large-scale boron isotope fractionation schemes. It is concluded that plant size could be significantly reduced by using any of these donors rather than dimethyl ether.

     

不锈钢三角螺旋高效填料在水-氢交换工艺中的性能研究

对液相水-氢交换工艺中的小型高效三角螺旋填料进行脱脂除油、亲水等进行了表面处理;通过总有机碳方法 TOC分析,处理工艺对填料的脱油效果明显,扫描电子显微镜SEM分析表明该处理工艺明显改善了填料比表面积。在典型的水-氢交换工艺条件下,处理过后的小型高效填料与Pt-SDB催化剂分层填装,该处理方式显著提高了水-氢交换性能,等板高度HETP降低至13.46 cm;进一步实验测定水-氢交换柱流体力学性能:床层持液量为0.03 m3/m3、床层压降为20 Pa/m,与理论计算一致。     

膜技术在氢气分离中的应用

与传统分离方法相比,膜分离技术在气体分离中的应用具有许多优势。氢气既是重要的工业原料又是清洁的燃料,近年来需求量剧增。简述了膜分离净化氢气的机理、使用的膜材料,并对其应用前景进行展望。     

膜分离氢回收技术的应用

三明化工有限责任公司合成氨厂的合成氨生产能力为25万t／a。为保证合成气中惰性气体含量处于适宜范围内，需要不断地排放部分循环气，这部分气体称为合成吹除气。吹除气量约4000～5000^m3／h，其组分体积分数为H257．28％、N219．11％、CH416．92％、Ar6．91％、NH39％。吹除气除供三聚氰胺及白炭黑生产所需外，其余均作为生活煤气使用。     

陶瓷分离膜技术在环境保护中的应用现状和展望

本文综述了陶瓷分离膜技术的发展过程及其主要的特点，并分类介绍了陶瓷分离膜技术在环境保护工程中的应用，最后对其的发展趋势进行了展望。