Sulfur addition to aldimines: thioamides,not thiaziridines,as products; revision of an old report

The reaction of 4-(phenylimino)butan-2-ol with ammonium polysulfide in refluxing EtOH yields 3-hydroxy-N-phenylbutanethioamide as the only isolated product. The structure has been established by single-crystal X-ray diffraction. Treatment of N-benzylidenamines with ammonium polysulfide has proven a general method for the preparation of thiobenzamides.     

关于如何对低硫灰口铸铁进行孕育处理的探讨

研究了低硫情况下电炉熔炼如何改进孕育效果的方法．研究表明，对含硫较低铸铁的孕育方法的改进，不一定非要通过补硫或改善孕育剂的方法来实现；通过增加原有孕育剂的数量、改进孕育方法同样能改善孕育效果．     

苯基异硫腈钴（I）配合物的合成与结构及性质

本文报导了三－三苯基膦氧化钴（Ｉ）与过量的异硫氰酸苯酯反应，依据快原子轰击质谱（ＦＡＢ－ＭＳ），证实生成物的结构为四员钴杂环配合物。该配合物不稳定，容易脱硫，生成苯基异腈钴（Ⅱ）配合物。     

硫自养反硝化中亚硝酸盐积累的研究现状与展望

以硫化物为基质的硫自养反硝化耦合厌氧氨氧化技术不但能除硫,还可以在硫循环的条件下实现高效脱氮.为实现该技术需要将硫自养反硝化过程控制在亚硝化阶段,随后进行以亚硝酸盐为电子受体的厌氧氨氧化反应.其关键在于如何实现亚硝酸盐的积累.文中介绍了硫自养反硝化的反应机理以及如何对影响亚硝酸盐,积累的因素进行精准调控,探讨了厌氧氨氧化-自养反硝化技术的主要途径.     

潜山高含硫井钻井优化设计与实践

结合潜山高含硫井的实际情况,对高含硫井井身结构、井眼轨迹进行了优化设计,对钻井液进行了优选,结合工程实际情况选择了相应级别的防硫井口装置和套管及主要附件,满足了高含硫井钻井施工安全、快速的要求。技术实用性强,为今后该类井在实际生产中的发展与应用提供了宝贵的经验。     

循环流化床锅炉脱硫的工业试验及模型预测

通过在７５ｔ／ｈ循环流化床锅炉上所进行的试验研究,取得了加石灰石脱硫的动态特性。依据循环流化床锅炉运行特点,对原有的循环流化床锅炉脱硫模型进行了部分改进,成为已建的循环流化床锅炉总体数学模型的一个子模型。运用该模型对循环流化床锅炉炉内ＳＯ２的生成和脱除进行模拟,模拟结果与工业试验结果吻合。模拟结果还揭示了加石灰石脱硫对循环流化床锅炉运行的影响。     

低浓度SO_2冶炼烟气液相催化气化初步扩大实验研究

在单层塔板泡沫吸收塔中对 SO_2液相催化氧化进行了初步扩大实验研究,当SO_2净化效率(单板效率)为50%时,得到10%(wt)H_2SO_4;硫酸生或速率为1.8%/h;SO_2吸收最佳液气比≤5 l/Nm~3;添加表面活性剂及鼓氧操作对 SO_2液相催化氧化有明显促进作用;冶炼烟气 SO_2浓度波动对吸收效率影响不大.实验结果表明,该法具有明显的环境,经济效益.     

SULFUR RECOVERY WITH REDUCED EMISSIONS, LOW CAPITAL INVESTMENT AND HYDROGEN CO-PRODUCTION

The main disadvantage of the Claus process is that by introducing air as oxidant a large volume of tail gas is produced. This must be treated to reduce atmospheric emissions of sulfur-containing gases. The costs of the tail-gas unit are a significant fraction of the total capital and operating costs for sulfur recovery. A new process uses thermal decomposition of hydrogen sulfide in the presence of carbon dioxide instead of air oxidation. The products of this reaction are hydrogen, carbon monoxide, elemental sulfur, water vapor and carbonyl sulfide. Carbonyl sulfide is easily converted to H₂S and C0₂ by liquid- or vapor-phase hydrolysis. Unreacted H₂S and C0₂ are recovered by absorption and recycled to the reactor. Since no air is introduced, there is no tail gas and the tail-gas unit is eliminated, giving a substantial reduction in capital investment. The concentrations of sulfur-containing gases in the product streams depend only on the operation of the absorber and stripper units and can be controlled to very low levels by increasing stripper boil-up. Process operating costs depend on the level of sulfur recovery required and can also be much lower than those of the modified Claus Process.

The process chemistry depends on a shift in the equilibrium of H₂S decomposition caused by reaction of hydrogen with C0₂ by the reverse of the water-gas-shift reaction. Catalysts for this chemistry have been identified. Reactor conversion is further improved by rapid cooling of the reactor effluent gas. Other aspects of process design and operation confer further advantages with respect to the Claus process; however, the process equipment used is similar to that used in a Claus plant. Retrofit of existing plant to the new technology can therefore be considered.     

采用有机盐─石膏脱硫剂的烟气脱硫新工艺

介绍一种利用有机羧酸盐作为吸收剂、以熟石灰作还原剂的烟气脱硫系统，在日本投入生产运行，其脱硫效率达９０％以上。     

Sulfur production from smelter off-gas using CO–H2 gas mixture as the reducing agent over modified Fe/γ-Al2O3 catalysts

A series of modified γ-Al₂O₃ supported iron-based catalysts (M-Fe/γ-Al₂O₃) was developed to reduce SO₂ in actual smelter off-gases using CO–H₂ gas mixture as reducing agent for sulfur production. Used as modifiers, three metal additives — Ni, Co, and Ce were added to Fe/γ-Al₂O₃ catalysts. Changes in catalyst structure and active phase were characterized with X-ray diffraction, XPS, SEM, and EDS. The reduction ability of catalysts was exhibited via CO-TPR. The prepared catalysts only need to be pre-reacted for a period of time, eliminating the need for presulfidation treatment. Reaction conditions were optimized in a fixed bed reactor to achieve high SO₂ conversion and sulfur selectivity. XRD characterization was carried out to verify the resulting sulfur products. Combining in situ infrared characterization and catalyst evaluation of support and active component, the reaction mechanism was investigated and proposed.