氟康唑在3%HCl溶液中对45钢的缓蚀性能

有机缓蚀剂用于钢铁的腐蚀防护具有用量少、缓蚀性能佳的特点,已得到广泛研究,其中,三氮唑类抗真菌药品氟康唑对碳钢的缓蚀研究报道较少。通过失重试验和电化学测试研究了氟康唑在3%HCl中对45钢的缓蚀性能。结果表明,氟康唑浓度较低时,缓蚀效率随浓度的增大而升高,浓度为650 mg/L左右时,缓蚀效率达到85.8%以上;但用量过高,缓蚀效率反而随浓度的增加而降低。动电位极化曲线测试证实氟康唑是一种抑制阳极过程为主的混合型缓蚀剂。氟康唑分子在碳钢表面的吸附行为服从Langmuir吸附等温式的自发过程,是物理吸附与化学吸附共同作用的结果。     

邻菲罗啉及其衍生物在1mol/L盐酸中的缓蚀性能研究

目的 制备高效、经济的邻菲罗啉衍生物缓蚀剂。方法 采用失重法、极化曲线、电化学阻抗法研究邻菲罗啉（PHEN）及其衍生物2-苯基-1H-咪唑[4,5-f]-1.10邻菲罗啉（PIPH）在不同浓度、不同温度下,在盐酸溶液中对低碳钢的缓蚀性能。采用扫描电镜（SEM）观测了未添加和添加不同缓蚀剂时低碳钢表面的腐蚀形貌。利用量子化学计算初步探讨了PHEN和PIPH分子结构与缓蚀效能的关系。结果 PHEN和PIPH的缓蚀效率均随着浓度的增加而增加,随着温度的升高而降低,在相同条件下,PIPH的缓蚀性能好于PHEN。30 ℃、缓蚀剂浓度为1 mmol/L时,PHEN和PIPH的缓蚀效率最高,分别为97.4%和99.5%。缓蚀剂在低碳钢表面遵循Langmiur吸附, 分别为?21.44和?24.28 kJ/mol。电化学测试结果显示,二者均为以阳极抑制为主的混合型缓蚀剂。扫描电镜结果显示,缓蚀剂有效抑制了盐酸对低碳钢的腐蚀。结论 PHEN和PIPH这两种缓蚀剂在1 mol/L盐酸介质中均表现出良好的缓蚀性能,且含有多氮吸附中心的PIPH缓蚀效果明显好于PHEN。     

PRO-pHx 酸活剂在电镀零件酸洗中的应用研究

目的研究PRO-p Hx酸活剂对酸洗过程及酸洗质量的影响,达到节酸、减排、降低成本的目标。方法通过添加PRO-p Hx酸活剂,对比分析酸洗溶液更换周期,以及不同的使用酸周期的成本。结果PRO-p Hx酸活剂体积分数在1%以下,即可长期保持钢铁零件酸洗液的活性以及零件的表面酸洗质量和电镀层质量,同时减少酸液废弃量。其中,1200 L的硫酸酸洗槽加入体积分数为1%的PRO-p Hx酸活剂,到第30个使用周期成本节约了33.6%,且随周期延长酸洗成本会进一步降低。结论 PRO-p Hx酸活剂添加到酸洗溶液中,在保证钢铁零件表面酸洗质量和电镀层质量的前提下,实现了节酸、减排、降低成本。     

A simple and fast method for the preparation of super active Pd/CNTs catalyst toward ethanol electrooxidation

For the first time, galvanic reduction by zinc sheet is used as a new strategy to prepare modified electrodes. In this work, glassy carbon electrode (GCE) was modified by decoration of Pd nanostructures on carbon nanotubes (Pd/CNTs). In this method, deposited PdCl₂ on CNTs was directly reduced to metallic Pd nanostructure using a zinc sheet in HCl (2% w/w) solution. This approach offers a number of advantages including being very fast, simple and green; and modified electrodes show high activity. The prepared catalyst is characterized by Field Emission Scanning Electron Microscopy, X-Ray Diffraction and energy-dispersive X-ray and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). In addition, electrochemical measurements show that the performance as well as the stability of the as-prepared catalyst for ethanol oxidation is outstanding. The Pd/CNTs catalyst shows higher mass current density, which is 7.9 times as high as that of commercial Pd/C.     

不同类型萃取剂对盐酸介质中钛、铁的萃取分离性能研究

在美国俄特尔公司提出的盐酸法萃取生产钛白粉萃取工艺和理论分析的基础上,研究了不同类型萃取剂D2EHPA、TOPO、TBP、TOA和N1923对不同浓度盐酸介质中钛、铁的萃取分离性能。研究结果表明：萃取剂D2EHPA、TOA分别可实现8~12M盐酸和4~12M盐酸介质中钛、铁的萃取分离;D2EHPA-TOPO萃取体系可实现6~12M盐酸介质中钛、铁的同时萃取。     

4,5-二甲基-1,3-二氧杂环戊烯-2-酮的合成

该文以有机碱作为缚酸剂,研究了4-氯-4,5-二甲基-1,3-二氧杂环戊烷-2-酮(CDMDO)脱氯化氢制备4,5-二甲基-1,3-二氧杂环戊烯-2-酮(DMDO)的工艺。优化的工艺条件为:N,N-二甲基苯胺作为缚酸剂,甲苯为溶剂,反应温度110℃,CDMDO转化率70%。     

硫酸钾生产装置配套生产氯磺酸

介绍利用曼海姆法生产硫酸钾的尾气(HCI气)与硫酸生产装置转化器3段引出的SO3气体在合成塔中生产氯磺酸(S02CIOH)的生产技术、工艺流程、运行中的问题与解决措施.该技术适宜在产生HCI尾气的装置和制硫酸装置共存的企业推广应用.     

Biogas from lignocellulosic feedstock: A review on the main pretreatments,inocula and operational variables involved in anaerobic reactor efficiency

Research focused on reusing lignocellulosic waste has been gaining ground, both for the purpose of obtaining energy from renewable sources, as well as for reducing feedstock costs and preventing environmental pollution. Despite being currently evaluated as a promising feedstock, large-scale application of lignocellulosic waste to obtain bioenergy is still scarce. One of the obstacles in terms of reusing it is its recalcitrant composition, often requiring pretreatment applications to break its fibers, increasing its bioavailability. In addition to the type of substrate, there are many operational parameters that may affect the process efficiency, including the type of reactor, temperature, pH, inoculum source, among others. Considering this, it is interesting to consider using statistical tools instead of “one-factor-at-a-time” methods for simultaneous optimization of these variables to increase the production of value-added compounds, such as Plackett-Burman screening design and Central Composite Rotational Design. In this context, this review aimed at compiling data regarding obtaining value-added compounds, focusing on bio-H₂ and bio-CH₄, from different lignocellulosic waste, such as sugarcane bagasse, citrus peel waste, coffee and cereal husks, brewer's spent grain, cocoa processing waste, sawdust, among others, considering the main operational parameters involved (temperature, pH, inoculum) and the type of pretreatment applied (physical, chemical and/or biological). The results described here may support future research on reusing residual lignocellulosic waste, in addition to elucidating the importance of different operational parameters to convert this waste into H₂ and/or CH₄.     

Simulation of chlorine-mediated autothermal methane pyrolysis for hydrogen production

Given the present need to access a large-scale supply of hydrogen in the short-term, methane pyrolysis for hydrogen production could be utilized as a transition technology, since existing natural gas infrastructures can be exploited. Here, a novel chlorine-mediated pyrolysis process is presented that overcomes the considerable challenges posed by the input of external energy in the direct methane pyrolysis. By operating at a methane to chlorine inlet ratio of roughly 1.5 to 1, the heat released by the exothermic chlorination reaction can be leveraged to generate hydrogen by pyrolysis in addition to the hydrogen chloride. A downstream hydrochloric acid electrolysis enables the chlorine to be recycled and produces further hydrogen resulting in an overall hydrogen yield of 99%. An approximate cost calculation highlights the main costs of the process and reveals the high outlays for the electrolysis unit.