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吡啶萃取对烟煤热解过程焦油生成特性的影响 《燃料化学学报》2017,45(11):1281-1288
煤中含有以非共价键结合的可萃取物,煤的萃取物和萃余物热解反应性不同。本研究首先用醋酸消除煤中静电作用力,再以吡啶萃取消除氢键作用力,通过热重和固定床研究了煤萃取物和萃余物的热解特性。相对于原煤,萃取物(E1)的H/C原子比较高,而萃余物(R1)比原煤的孔径有所增大。热重实验表明,萃取物热分解温度低,失重率大;萃余物在485℃之前失重大于原煤,温度高于485℃小于原煤。固定床氮气热解表明,萃取物(E1)的焦油产率和气体比原煤高;萃余物(R1)的焦油产率低于原煤焦油产率。而氢气气氛下,萃取残渣的焦油产率明显高于原煤,这是由于吡啶萃余物具有更开放的孔结构,有利于加氢热解过程氢向孔内扩散,减少了缩聚反应。 相似文献
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双(十二烷基亚磺酰)乙烷溶剂萃取钯及其机理的研究 总被引:2,自引:0,他引:2
本文研究用双(十二烷基亚磺酰)乙烷萃取钯的性能,在KI存在下从7mol/L盐酸介质中用含有BDSE的氯仿能定量萃取钯,有机的钯可被硫脲或氨溶液反萃继之用TMK-TritonX-100光度法测定,研究了萃取的最佳条件及干扰情况,斜率法测得萃合物组成为Pd:I:BDSE=1:2:1,红外光谱证实萃合物中BDSE的二个亚砜以硫原子与钯配位,萃合物为异位体络合物,提出了选择性萃取分离钯的新方法。 相似文献
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本文研究了标题化合物对铁(Ⅲ)、钴(Ⅱ)和镍(Ⅱ)的萃取行为,其pH_(1/2)值分别为2,43、5.08和4.51。斜率法求得萃合物组成分别为Fe_2A_3、CoA和NiA。对固态铁萃合物作了红外光谱和热谱研究,并用饱和萃取法和等摩尔系列法对其组成作了进一步证实。 相似文献
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《燃料化学学报》2017,(11)
煤中含有以非共价键结合的可萃取物,煤的萃取物和萃余物热解反应性不同。本研究首先用醋酸消除煤中静电作用力,再以吡啶萃取消除氢键作用力,通过热重和固定床研究了煤萃取物和萃余物的热解特性。相对于原煤,萃取物(E1)的H/C原子比较高,而萃余物(R1)比原煤的孔径有所增大。热重实验表明,萃取物热分解温度低,失重率大;萃余物在485℃之前失重大于原煤,温度高于485℃小于原煤。固定床氮气热解表明,萃取物(E1)的焦油产率和气体比原煤高;萃余物(R1)的焦油产率低于原煤焦油产率。而氢气气氛下,萃取残渣的焦油产率明显高于原煤,这是由于吡啶萃余物具有更开放的孔结构,有利于加氢热解过程氢向孔内扩散,减少了缩聚反应。 相似文献
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BPMOPP与1,10—菲咯啉对铈的协同萃取 总被引:3,自引:1,他引:3
研究了1,2-双(1'-苯基-3'-甲基-5'-氧化吡唑-4'-基)-1,2苯二酮对盐酸介质中铈的萃取变价为及与1,10-菲咯啉从盐酸及盐与甲酸钠缓冲溶液中对铈的协同萃取得为,斜率法测定协萃合物的组成的CeA.HAphen,求得了协萃平衡常数,萃取法制得了固态配合物,对其组成,UV,IR,HNMR,TG-DTA进行了研究,讨论了协萃机理豚萃合物的可能结构。 相似文献
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三正辛基氧化膦萃取钯的研究 总被引:6,自引:0,他引:6
本文研究了用三正辛基氧化膦(TOPO)煤油溶液从盐酸介质中萃取钯及用硫脲反萃钯的条件。用等摩尔系列法、饱和法、化学分析法和斜率法确定了萃合物的组成。用紫外-可见光谱法探讨了TOPO萃取钯的机理。 相似文献
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逐级提取-高效液相色谱法快速测定植物组织中8种有机酸 总被引:2,自引:0,他引:2
针对植物组织中草酸存在的不同形态,建立了水和稀盐酸作为提取介质的逐级提取方法,获得了水溶态和酸溶态草酸及乙醇酸、乙醛酸、酒石酸、苹果酸、乙酸、柠檬酸、琥珀酸等有机酸。采用Hypersil ODS (200 mm×4.6 mm, 5 μm)色谱柱,以5 mmol/L磷酸二氢钾水溶液(pH 2.8)作为流动相,在进样量5 μL、检测波长210 nm、柱温30 ℃的条件下,通过分时段控制流速实现了8种有机酸的快速分离,同时去除了盐酸对酸溶态草酸测定的干扰。本方法精确灵敏、回收率高、重复性好,可应用于实际样品的测定分析。 相似文献
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C. S. Kedari S. S. Pandit A. Ramanujam 《Journal of Radioanalytical and Nuclear Chemistry》1997,222(1-2):141-147
The process of in situ electro-oxidation of Ce(III) to Ce(IV) followed by its extraction into the organic phase has been investigated for its applicability in the separation of Ce from nitrate medium. Solvent extraction of cerium from nitric acid after its electro-oxidation to fourth valency state was carried out using tributyl phosphate (TBP) and 2-ethylhexyl hydrogen 2-ethylhexyl phosphonate (KSM-17, equivalent to PC-88A). The efficiency of the extractants at different aqueous phase nitric acid concentrations and different electrode potentials were determined. Various reducing agents such as hydroxylamine hydrochloride, sodium nitrite, ferrous sulphate as well as complexing agents like EDTA, oxalic acid etc, were studied as strippants for the back extraction of cerium from the loaded organic phase. The method developed for the extraction of cerium was further extended to the partitioning of cerium from Ce-Am mixture obtained during the KSM-17 based extraction chromatographic elemental fractionation of PUREX High Activity Waste (HAW) solutions. Recovery of Ce obtained in the extraction experiments by batch as well as by continuous flow organic phase was >95% with good radiochemical purity. 相似文献
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反相高效液相色谱法测定植物组织及根分泌物中草酸 总被引:12,自引:0,他引:12
采用反相C1 8柱 ,2 2 0nm紫外检测 ,0 .5 %KH2 PO4 0 .5mmol L四丁基硫酸氢铵 (tetrabutylammoniumhydrogensulfate ,TBA) (pH 2 .0 )的水溶液体系 ,可使草酸及其它测试的 6种有机酸及硝酸有效分离。进一步研究了该方法测定植物组织及根分泌物中草酸的效果 ,结果表明其精确灵敏、回收率高、重复性好 ,并且成本低、操作简便 ,可应用于各种生物材料、食品、饮料等产品中的草酸含量检测。 相似文献
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Extraction of oxalic acid by ion-pair formation with application to the determination of oxalic acid in urineThe yield of ion-pair extraction of oxalic acid by trioctylamine and triisooctylamine in chloroform depends on the pH of the aqueous phase. The optimum pH is 2.7, proving that hydrogenoxalate ion is the extractable form. Extraction yield depends on the acid used for pH adjustment and dissolution of the calcium oxalate formed in complex medium. The best results are obtained with hydrochloric and sulfuric acids and with trioctylamine extraction. This extraction was applied to oxalic acid determination by colorimetry and gas chromatography in urines from twenty healthy patients. Mean excretion was found to be Extraction yields lie between 94 and 106%. 相似文献
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The extraction of strontium from nitric acid medium was investigated employing DCH18C6 in aliphatic alcohols as the diluents. 80% Butanol-20% octanol mixture was found to give higher D(Sr) values as compared to other alcohols investigated. A linear correlation between the organic phase water content and D(Sr) was observed, based on which the extraction mechanism was postulated. Effect of anion, cation, extractant concentration, nitric acid concentration and temperature on D(Sr) was also studied. Conditions for recovery (>90%) were arrived at and selectivity with respect to other interfering fission products was observed with most of the metal ions studied. 相似文献
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Aqueous-phase chemistry of glyoxal may play an important role in the formation of highly oxidized secondary organic aerosol (SOA) in the atmosphere. In this work, we use a novel design of photochemical reactor that allows for simultaneous photo-oxidation and atomization of a bulk solution to study the aqueous-phase OH oxidation of glyoxal. By employing both online aerosol mass spectrometry (AMS) and offline ion chromatography (IC) measurements, glyoxal and some major products including formic acid, glyoxylic acid, and oxalic acid in the reacting solution were simultaneously quantified. This is the first attempt to use AMS in kinetics studies of this type. The results illustrate the formation of highly oxidized products that likely coexist with traditional SOA materials, thus, potentially improving model predictions of organic aerosol mass loading and degree of oxidation. Formic acid is the major volatile species identified, but the atmospheric relevance of its formation chemistry needs to be further investigated. While successfully quantifying low molecular weight organic oxygenates and tentatively identifying a reaction product formed directly from glyoxal and hydrogen peroxide, comparison of the results to the offline total organic carbon (TOC) analysis clearly shows that the AMS is not able to quantitatively monitor all dissolved organics in the bulk solution. This is likely due to their high volatility or low stability in the evaporated solution droplets. This experimental approach simulates atmospheric aqueous phase processing by conducting oxidation in the bulk phase, followed by evaporation of water and volatile organics to form SOA. 相似文献
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用H2O2氧化苯乙烯合成苯甲酸 总被引:2,自引:1,他引:1
摘要:以30%H2O2做为氧化剂,钨酸钠与含O双齿有机配体(草酸)形成的络合物为催化剂,在无有机溶剂、无相转移剂的条件下,研究了苯乙烯氧化制苯甲酸的反应。研究结果表明,最佳反应条件为:苯乙烯100.0mmol,n(钨酸钠):n(草酸):n(苯乙烯):n(30%H2O2)=2.0:3.2:100.0:440.0,于92℃反应24h,苯甲酸收率98.6%。用GC—MS跟踪了氧化过程中4种主要物质苯乙烯、1-苯基邻二醇、羟基苯乙酮及苯甲酸含量随反应时间的变化关系,提出了其主要氧化机理为苯乙烯经过环氧化反应、水解生成生成1-苯基邻二醇,1-苯基邻二醇再氧化为羟基苯乙酮、最后氧化为苯甲酸。 相似文献
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Lamouroux C Moulin C Tabet JC Jankowski CK 《Rapid communications in mass spectrometry : RCM》2000,14(19):1869-1877
Liquid-liquid extraction of zirconium, one of the most important fission products, was followed using electrospray ionization mass spectrometry under conditions simulating reprocessing of nuclear spent fuel. Zr(IV) can precipitate from the organic phase after extraction by dibutylphosphoric acid (HDBP), the most common degradation product of tributylphosphate (TBP) radiolysis. Different complexes were detected with electrospray used in positive or negative ion modes, according to the extraction conditions such as the ligand/metal ratio. Stoichiometry of the Zr(IV) complexes was determined by combining isotopic labeling [H(15)NO(3)] of the aqueous phase in the extraction system and tandem mass spectrometry experiments. These results were compared with the species observed using other techniques reported in the literature. The mechanisms of ionization/desorption of these complexes are proposed depending on the organic ligand character (neutral (L) such as TBP, or acidic (HL') such as HDBP), and the ionization mode used. Copyright 2000 John Wiley & Sons, Ltd. 相似文献
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采用草酸脱铝对USY分子筛进行了改性,考察了草酸加入量对USY相对结晶度(CRX)、硅铝比(nS iO2/nA l2O3)、比表面积、孔结构及加氢裂化性能的影响,并采用程序升温脱附和原位红外光谱技术对改性USY型分子筛的酸性进行了表征。结果表明,随草酸加入量的增加,在脱除USY中非骨架铝的同时,骨架铝被脱除的量也逐渐增多,致使USY的相对结晶度先提高而后降低、硅铝比提高、酸强度和酸量降低。正癸烷的加氢裂化结果表明,当草酸的加入质量比为0.2时,正癸烷的转化率和一次裂化产物的选择性分别为68.5%和80.1%。草酸改性USY具有高催化活性是因为该分子筛具有空旷的介孔结构和较多的可接近的酸性位;一次裂化产物选择性高是因为空旷的介孔结构使裂化产物快速离开酸性位而避免了二次裂化。 相似文献