有机碱作为蒽醌降解物再生催化剂的研究

为克服蒽醌法生产过氧化氢工艺中普遍使用的蒽醌降解物再生催化剂碱式氧化铝的缺点,以苯胺、1-萘胺、吡啶、N,N′-二丁基苯胺、N,N′-二甲基苯胺、N-甲基吗啉、乙胺、乙二胺8种有机碱作为再生催化剂,研究了这些催化剂对工作液中蒽醌降解物的再生效果。结果表明,工作液中有效蒽醌增量随着有机碱催化剂碱性的增加呈现先增后减的规律。电离平衡常数pKa在5.20~5.49的3种有机碱N,N′-二甲基苯胺（pKa=5.20）、吡啶（pKa=5.30）、 N,N′-二丁基苯胺（pKa=5.49）为催化剂时,工作液中2-乙基蒽醌（EAQ）增量和有效蒽醌增量均比碱式氧化铝为催化剂时高,其中以N,N′-二丁基苯胺的催化性能和稳定性最好。最佳反应条件：催化剂用量为0.8%（质量分数）、反应时间为24 h、反应温度为40 ℃、氧气流速为30 mL/min。     

新型蒽醌加氢催化剂的制备及加氢性能研究

在蒽醌法生产过氧化氢中,采用蝶形氧化铝载体,通过控制贵金属浸渍条件,制备出蛋壳分布的新型钯催化剂。催化剂贵金属负载量低,活性组分浸渍层薄,催化剂活性高及反应稳定性好。实验室和工业模式评价实验表明,制备的催化剂表现出良好的活性及稳定性,其时空产率为工业用催化剂的1.5倍以上。     

新型蒽醌加氢催化剂的制备及性能研究

以蒽醌法生产过氧化氢,采用齿轮球形氧化铝载体,通过载体硅改性和负载活性组分Pd,制备新型固定床蒽醌加氢催化剂EK-CL。与目前工业使用的催化剂相比,新型蒽醌加氢催化剂具有最可几孔径大、活性组分浸渍层薄、堆积密度低以及活性组分含量低的优点。在小试和中试装置上考察催化剂的催化性能,结果表明,催化剂表现出较好的活性及较低的氢化塔压力降,具有良好的工业应用前景。     

Heterogeneous Fenton catalyst derived from hydroxide sludge as an efficient and reusable catalyst for anthraquinone dye degradation

Hydroxide sludge (HS) is the main by-product of drinking water production stations. In our work, we have promoted the valorization of these sludge, we convert it into activated carbon to serve as a support as a heterogeneous Fenton catalyst for reactive blue 19 (RB 19) degradation. The HS and Fe/HS-300 were characterized by means of SEM, EDX-ray, FTIR and XRD analysis. RB 19 and TOC removals were 92% and 41% respectively in optimal condition. More importantly, Fe/HS-300 exhibited an excellent stability and low Fe ion leaching (0.2–0.7mg/L), it was recycled 6 runs still maintaining the same efficiency.     

Hydrogenation of fats and oils. Isomerization during hydrogenation

This presentation includes a survey of the development of the presently accepted theory for the formation of isomers based on a half hydrogenation-dehydrogenation mechanism with atomic hydrogen, an appraisal of the relevant work of recent years for its significance when applied to the problem of isomerization, and certain experimental evidence from other fields of heterogeneous catalysis of interest in the hydrogenation of fats and oils. Effects of temperature, pressure, catalyst concentration, and degree of agitation used in commercial plants on the degree of isomerization are discussed. In addition the conditions necessary for the proper application of the term “selective” to a hydrogenation are examined. An interpretation of recent work to reduce isomerization while retaining selectivity by extending the normal range of the variables and by the use of solvents is covered. Selected works on catalysis from related fields are used to indicate possible modifications of the isomerization mechanism and, perhaps, to reveal fruitful avenues of research. Presented at the AOCS meeting in New Orleans, 1962.     

N-bromosuccinimide in the conjugation of fatty acids and oils

1. A series of methyl esters of fatty acids were reacted with N-bromosuccinimide, and the products were dehydrobrominated by heating.
2. In the reaction of metyyl erucate and methyl oleate with equivalent amounts of N-bromosuccinimide, bromination occurred in the allylic position farthest from the carboxyl group. Products of dehydrobromination contained 30–40% conjugated dienoic acids.
3. Use of excess N-bromosuccinimide led to production of both diene and triene conjugation.
4. Products from mono-acetylenic fatty acids had a double bond conjugated to the triple bond initially present.
5. The product from methyl 9∶12-linoleate was a complex mixture having diene, triene, and tetraene conjugation.
6. Mustard seed, peanut, olive, karanja, neem, tobacco seed, and safflower oils were reacted with N-bromosuccinimide. The bromo derivatives could not be satisfactorily dehydrobrominated by heat alone; heating in pyridine, quinoline, or 2∶4∶6-collidine was more effective. The products from safflower and tobacco seed oils partially gelled during the process. The films of all the treated oils dried in wrinkled patterns.

     

异构化制清洁汽油工艺及催化剂

介绍了异构化工艺制清洁汽油的研究现状,综述了近年来国内外轻石脑油异构化工艺及催化剂的应用与发展。简述了目前国内外主要工业化应用的异构化工艺。从活性金属和载体两方面简单介绍了双功能型金属/酸异构化催化剂的研究与发展。着重阐述了固体超强酸异构化催化剂的特点,详细说明了通过促进剂、载体及活性金属元素的引入等方面对SO₄^2-/ZrO₂型固体超强酸异构化催化剂改性方面的研究进展。通过对目前已商业应用的异构化工艺的对比,对异构化催化剂所面临的主要问题进行探讨。最终指出异构化制清洁汽油将成为我国汽油生产的重要技术手段之一,经济、环保、高效的固体超强酸催化剂将大规模工业应用于异构化催化中。     

Isomerization of d-glucose into d-fructose with a heterogeneous catalyst in organic solvents

The isomerization of d-glucose into d-fructose was investigated in view to afford carbohydrate source for the production of 5-hydroxymethylfurfural (HMF) without the use of toxic metallic catalyst. The process uses a basic heterogeneous catalyst in organic solvent mixtures to lead up to 72% selectivity of d-fructose for 68% conversion of d-glucose. The catalyst has been recycled four times with little decrease of the selectivity. The resulting carbohydrates solution can be directly dehydrated to afford HMF.     

Bleaching of drying oils by ionizing radiation

Summary (1) Changes in the absorption spectra of drying oils, especially safflower, on exposure to ionizing radiation were followed. (2) Bleaching of the oil was plotted as a linear function of the logarithm of the absorption in the visible spectrumversus the dose. (3) Oxygen inhibited radiation bleaching. (4) The cost of bleaching safflower and similar oils by electrons was estimated to be about 4 cents/pound. (5) The mechanism of radiation bleaching was postulated to involve hydrogenation of the pigments by hydrogen atoms. These were obtained by dehydrogenation of the oils or by decarboxylation of fatty acids.     

蒽醌降解物再生新型催化剂的制备与表征

以氢氧化铝直接快速脱水为原料制备蒽醌降解物再生新型催化剂。运用表面原位生长技术,采用固体碱与催化剂掺杂复配技术,制备出了孔容≥0.55 mL/g、比表面积≥180 m2/g、再生活性≥5 g/L、使用寿命≥90 d的条状蒽醌降解物再生新型催化剂。表面原位生长技术有利于氧化铝一次粒子长大,增大间隙孔,从而制备出大孔容、高比表面积的活性氧化铝;固体碱与催化剂掺杂可以强化碱性活性组分与载体的相互作用,避免碱液活性组分的快速流失,从而大大提高新型催化剂的活性和使用寿命。     

蒽醌生产方法及其催化剂研究进展

论述了国内外制备蒽醌的方法及其催化剂,并简单介绍了国内蒽醌生产方法的应用。通过比较,认为蒽气相氧化法具有原料充足、环境友好、操作简便等优点,符合目前环境对蒽醌生产行业的要求,是较为理想的蒽醌生产方法。催化剂是以Al2O3为载体的V2O5为主体的复合催化剂。国内近年大量上马一批蒽气相氧化项目,但多引进国外技术,研究和开发国产催化剂和设备已成为蒽醌生产行业的迫切任务。     

The use of nitrogen-doped graphene supporting Pt nanoparticles as a catalyst for methanol electrocatalytic oxidation

Nitrogen-doped graphene (N-G) was prepared by thermal annealing of graphene oxide in ammonia at different temperatures. The resultant N-G was used as a conductive support for Pt nanoparticles (Pt/N-G) and the electrocatalytic activity of the Pt/N-G catalysts towards methanol oxidation was examined. To investigate the microstructure and morphology of the synthesized catalysts, X-ray diffraction, scanning and transmission electron microscopy and X-ray photoelectron spectroscopy were used. The catalytic activity of the catalysts towards the oxidation of methanol was evaluated by cyclic voltammetry. Compared to a control catalyst of Pt loaded on undoped graphene, the Pt/N-G materials show higher electrochemical activity towards methanol oxidation. The excellent electrochemical performance of Pt/N-G is mainly attributed to the nitrogen doping and the uniform distribution of Pt particles on the doped graphene support. These results indicate that N-doped graphene has great potential as a high-performance catalyst support for fuel cell electrocatalysis.     

Survey of seed oils for use as diesel fuels

Fifty-one out of 364 plant seeds being surveyed had fatty acid contents greater than 15% (dry weight), and their methyl esters had cetane indices higher than 50. Rambutan seed was an exception, with a lipid content of only 14.7%, but a high cetane index (67.1); thus, it was included in this report. Twenty seed oil methyl esters had cetane indices greater than 60. Three seed oils from the Sapindaceae family not only had high cetane indices but also contained long-chain fatty acids of 20 carbon atoms. Gross heats of combustion of the fatty acid methyl esters were slightly higher than those of neat oil, ranging from 38.2 to 40.8 j/g, whereas the heating values of the oils ranged from 37.4 to 40.5 j/g. Thus, these plant seed oils have great potential for development as diesel fuel or diesel fuel extender.     

蒽醌加氢钯催化剂载体改性研究

针对Pd/Al2O3催化剂载体的改性进行研究,将1 000℃焙烧后的氧化铝粉末与未焙烧的活性氧化铝粉末按不同比例混合和焙烧制备载体,采用等体积浸渍法制得负载Pd的Pd/Al2O3催化剂。采用XRD、BET、NH3-TPD和HOT对载体以及催化剂进行表征,并考察催化剂的蒽醌加氢性能。结果表明,提高载体中焙烧后氧化铝粉末的比例,导致载体中γ-Al2O3减少和δ-Al2O3增多,载体酸性降低,Pd分散度变大,从而提高了催化剂氢化效率。当焙烧后氧化铝质量分数为40%时,分散度和活性表面积达到最大,晶粒度最小,氢化效率最高,催化活性最佳。