硅酸锆负载壳聚糖吸附废水中铅离子的工艺研究

以颗粒状硅酸锆(ZrSiO4)作为载体,通过浸渍的方法将壳聚糖负载其上,制得壳聚糖-ZrSiO4吸附剂。用该吸附剂处理废水中的铅离子(Pb2+),考察了体系pH值、温度、时间等工艺条件对吸附和脱附效果的影响。结果表明,在Pb2+溶液初始质量浓度为5.0 mg/L,pH值为6.0,吸附剂用量为24.0 g/L,吸附温度为30℃,吸附时间为1 h的优化条件下,该吸附剂对溶液中Pb2+的最大吸附率为86.4%,相应其最大吸附容量为180.1μg/g;用去离子水洗涤壳聚糖-ZrSiO4饱和吸附剂,调节脱附体系pH值为2.0,在10℃震荡10 min,该吸附剂对Pb2+的脱附率可达93.5%。     

改性蒙脱土与壳聚糖复合吸附剂制备及对Cu2+吸附性能评价

以壳聚糖和改性蒙脱土为原料,制备了改性蒙脱土与壳聚糖复合吸附剂.考察了复合吸附剂用量、显色剂双硫腙用量、溶液pH、反应温度及反应时间对Cu2+吸附率的影响.结果表明,在复合吸附剂用量0.4 mL,吸附时间30 min,显色剂用量1.5 mL,溶液pH 5.5～6.5,cu2+浓度(o.1～0.5)×10-3mg·mL-1,反应温度60℃的条件下,复合吸附剂对Cu2+的吸附率可达90%以上.     

Mn（Ⅱ）催化硝酸氧化草酸反应动力学及机理分析

硝酸体系内以草酸为还原剂，以Mn²⁺离子为催化剂，对Mn(Ⅱ)催化硝酸氧化草酸反应进行动力学研究，掌握其中的反应机理。分析草酸与硝酸浓度对反应过程造成的影响，得出初始动力学速率情况，判断Mn²⁺离子与亚硝酸钠的浓度对反应速率产生的影响。经过研究得知：Mn²⁺离子浓度在达到0.02mol/L时，Mn²⁺的反应级数是0.6742。由此可见，Mn²⁺离子和亚硝酸钠浓度的提高会促进草酸的消耗，提高草酸消耗速度，缩短草酸分解时间，关于该实验的反应机理，即Mn²⁺离子促进亚硝酸生成，亚硝酸和草酸的氧化还原反应能够推动草酸的进一步分解，发挥草酸与Mn²⁺离子的还原剂与催化剂应用作用。     

炼油厂VOCs吸收-吸附耦合工艺研究

采用负载浸渍法,将活性金属铜引入活性炭孔道内部,并且对其进行N₂吸附-脱附及透射电镜表征。使用改性后的AC-2活性炭吸附剂吸附脱除苯模型化合物,当入口苯质量浓度为6.5 g/m³、体积空速为1 000 h^-1、吸附温度为20℃时,穿透时间为13 h,吸附量为132 g。经过8个吸附-再生周期,AC-2活性炭吸附剂仍可将固定床吸附器出口苯质量浓度控制在30mg/m³以下。使用改性后的AC-2活性炭吸附剂吸收-吸附脱除石脑油中的VOCs（挥发性有机物）,在进气口VOCs质量浓度为100～150 g/m³、体积空速为1 000 h^-1、吸附温度为20℃的条件下,其穿透时间为4.5 h。经过4个柴油吸收-吸附-再生周期,AC-2活性炭吸附剂仍维持较稳定的脱VOCs性能。热脱附模型相较于常温脱附模式,更加适用于活性炭吸附剂的脱附再生。     

负载型杂多酸的制备、表征及其对煤焦油的脱氮性能

采用等体积浸渍法制备了3种负载型杂多酸吸附剂,通过傅里叶红外光谱、N_2吸附-脱附(BET)对吸附剂进行了表征。以煤焦油为原料,硅胶负载杂多酸为吸附剂,考察了不同条件对煤焦油脱氮率的影响,分别应用拟一阶、拟二阶动力学模型、Freundlich吸附等温方程和Langmuir吸附等温方程对实验数据进行了拟合。结果表明,在磷钨酸负载质量分数为30%、吸附温度为60℃、吸附时间为50min、剂油质量比为1∶5的条件下煤焦油的脱氮率为85.7%。吸附过程符合准二级动力学模型,吸附剂对碱性氮化物的理论平衡吸附量为qe′=7.161mg/g,Langmuir吸附等温式的拟合度较好,吸附作用为单分子层吸附。     

介孔碳及其铁改性材料吸附水中对硝基苯酚

采用水热合成法以F127为模板剂制备介孔碳材料（MC）,一步合成法引入Fe(NO ₃ ) ₃ •9H₂O得到铁改性介孔碳材料（Fe/MC-x,x为合成原料中铁源与间苯二酚的摩尔比,x=0.5、1、1.5）,对改性前后的材料进行TEM、N₂吸-脱附、XRD及FI-TR表征,通过考察吸附剂量、吸附等温线、吸附动力学对其吸附水中对硝基苯酚（p-NP）进行了研究。结果表明,所得MC和Fe/MC-x的孔径分布集中于3~4 nm,比表面积分别为643.6、635.6、636.0和587.2m²/g。实验条件下,Fe/MC-x的吸附性能优于MC,其中Fe/MC-1.0有最大吸附量220.35 mg/g,对应去除率为92.33%;平衡吸附量均与初始浓度呈正相关,与吸附剂投加量呈负相关,高温不利于吸附,P-NP在MC和MC-x上的吸附行为符合Freundlich模型;改性行为加快了吸附速率,吸附过程符合准二级动力学模型,主要为化学吸附控制吸附速率。     

稀土元素对Cu~+-13X分子筛吸附2,5-二甲基噻吩和苯并噻吩的影响

采用离子交换法制备了Cu~+-13X及负载稀土元素Ce的Cu~+-13X分子筛(Ce/Cu~+-13X)吸附剂,分别从静态吸附平衡及动力学测试两方面考察了两种吸附剂对2,5-二甲基噻吩和苯并噻吩的吸附性能;分别采用Langmuir模型和修正的Langmuir模型对单、双组分静态吸附平衡数据进行拟合,采用Crank单孔扩散模型对动力学数据进行拟合。拟合结果表明,数据与模型吻合均很好。计算得到了Ce/Cu~+-13X吸附剂对2,5-二甲基噻吩和苯并噻吩单组分的最大吸附量分别为165.1,193.0 mg/g,分别大于Cu~+-13X吸附剂对2,5-二甲基噻吩和苯并噻吩的最大吸附量(153.6,180.2 mg/g)。负载稀土元素对Cu~+-13X吸附剂的吸附性能有一定的促进作用,能够减弱2,5-二甲基噻吩和苯并噻吩之间的竞争吸附。     

硫脲改性壳聚糖微球对Pt~(4+)和Pd~(2+)的吸附特性Ⅰ.吸附平衡和动力学

利用反相乳液法制备了壳聚糖微球,并经硫脲改性得到硫脲改性壳聚糖微球(TCS),将其用于吸附Pt4+和Pd2+,考察了TCS对Pt4+和Pd2+的吸附特性;利用扫描电子显微镜、傅里叶变换红外光谱和N2吸附-脱附等方法对TCS进行了表征。表征结果显示,TCS的粒径为10～30μm、比表面积为95.6m2/g、平均孔径为12.6nm、孔体积为0.298cm3/g。实验结果表明,在pH=2时,TCS对Pt4+和Pd2+的吸附性能最佳;吸附动力学可用拟二级模型拟合,表明TCS对Pt4+和Pd2+的吸附以化学吸附反应为主;吸附等温线可用Langmuir模型拟合,Pt4+和Pd2+的饱和吸附容量分别为129.87,112.36mg/g。双组分吸附实验结果表明,TCS对Pt4+和Pd2+有良好的吸附选择性,可实现Pt4+(或Pd2+)与Cu2+,Pb2+,Cd2+,Zn2+,Ca2+的选择性分离。     

交联壳聚糖对酸性红B的吸附研究

实验以壳聚糖为原料,在碱性条件下以环氧氯丙烷对壳聚糖进行了化学改性,制得不溶于水的交联壳聚糖。研究了交联壳聚糖对偶氮染料酸性红B的吸附平衡规律,探讨了交联壳聚糖对酸性红B的吸附动力学规律以及初始浓度、pH值对吸附的影响,并且与壳聚糖在相同条件下做了对比实验。结果表明:交联壳聚糖对酸性红B的吸附性能优于壳聚糖。其吸附规律符合Langmuir吸附等温式,最大吸附容量为227.27 mg/g;其吸附动力学模型可以用准二级速率方程来描述,准二级动力学常数为4.06×10~(-4)g/(mg·min)。     

USY分子筛对碱性氮的吸附性能及在焦化蜡油脱氮中的应用

在间歇式微型反应釜、微型固定床反应器中,以USY分子筛为吸附剂,分别进行静态吸附和动态吸附脱除油品中碱性氮化物的试验,研究其吸附脱氮工艺条件及性能。结果表明:碱性氮化物在USY分子筛上吸附的最佳温度为140℃,适宜剂油质量比为1∶30,适宜的吸附时间为30min,此时,吸附量为31.4mg/g,脱氮率为89.5%;吸附动力学可用准二级动力学方程表示为:qt=t/(0.024 5+0.031 2 t);吸附等温线是典型的化学吸附曲线,可用Langmuir等温吸附式表示为:Qe=14.35Ce/(1+0.451 2Ce);USY分子筛可将焦化蜡油中的碱性氮含量由1 705.2μg/g吸附脱除降低到813.1μg/g。     

A novel La3+–Zn2+–Al3+–MoO42− layered double hydroxides photocatalyst for the decomposition of dibenzothiophene in diesel oil

A new type of photocatalyst, La³⁺-Zn²⁺-Al³⁺-MoO₄^2? layered double hydroxide (LDH) (La:Zn:Al = 1:7:2), was prepared by a complexing agent-assisted homogeneous precipitation technique. The LDHs were used as catalysts for the desulfurization of diesel oil under UV irradiation. As revealed by the results, the catalyst showed superior desulfurization efficiency and recycling performance. Under UV irradiation, the desulfurization efficiency was 84% in 60 min. In La³⁺–Zn²⁺–Al³⁺–MoO₄^2? LDHs, the introduction of MoO₄^2? increased the interlayer space for promoting the adsorption of dibenzothiophene, and MoO₄^2? might act as the active sites for the oxidation of dibenzothiophene, resulting in the high desulfurization efficiency.     

Na+质量浓度对三元复合体系的影响

 阳离子对三元复合体系(表面活性剂+聚合物+NaOH,alkaline/surfactant/polymer,简称ASP)的性能影响较大。在纯水配制的三元复合体系中,利用NaOH和NaCl的质量分数来调节其中Na⁺的质量浓度,考察三元复合体系中Na⁺质量浓度对体系黏度及其与原油之间油-水界面张力的影响。结果表明,三元复合体系中Na⁺质量浓度达到较高值时,三元复合体系黏度就不再变化。在三元复合体系中,无论是NaOH质量分数高而NaCl质量分数低,还是NaCl质量分数高而NaOH质量分数低,只要体系中Na⁺质量浓度在5200~7700 mg/L,就能与原油形成超低油 水界面张力,这是三元复合体系Na⁺质量浓度的变化导致表面活性剂分子在油-水界面上的吸附发生变化的结果。     

硅-铝催化剂酸中心失活与再生的分析

含 Si、Al 元素的固体酸催化剂,其活性来源于其酸性,催化剂的失活与再生一定程度上是其酸性中心的失活与再生。L酸中心具有吸引孤对电子的空轨道,空轨道是L酸中心的活性中心;B酸中心能提供 H⁺,H⁺是B酸中心的活性中心。L酸中心的空轨道被孤对电子占据后,L酸中心失去活性,B酸中心给出 H⁺后也会失去活性。烯烃在L酸中心作用下生成了环正碳离子,环正碳离子从失活的L酸中心获取H^-生成了环烷烃,而失活的L酸中心在给出 H^-的同时,占据活性中心的1对电子被去掉,变成为空轨道,这样L酸中心又具有吸引孤对电子的能力,又恢复了活性。如果环正碳离子提供 H⁺给失活的B酸中心,C⁺与相邻的提供 H⁺的C原子各自的2个sp³轨道相互作用形成-C=C-双键,即生成了环烯烃,使失活的B酸中心再次获得 H⁺后其活性也得到了恢复。     

MANAGEMENT OF COAL MACERALS IN THE LIQUEFACTION OF LOW RANK COALS

ABSTRACT

Three Alberta subbituminous coals were selected to investigate the contribution of different macerals to liquefaction. These coals represent the full range of geographic, rank and geological variations present In the Alberta Plains Coal Region. In addition, for comparison, two U.S. lignites (Texas and North Dakota) were included in these investigations. To enhance maceral concentration, density fractionation was carried out on these samples. Though liquefaction yields appear to increase with increase in vitrinite (huminite) content, a clear-cut correlation between conversion and maceral content is not established because of (a) uncertain behaviour of semi-inert macerals and (b) differences in behaviour within the vitrinite (huminite) macera1 group.     

4,10-Dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo[5.5.0.05,903,11]dodecane Synthesis

4,10-Dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo[5.5.0.0^5,90^3,11]dodecane (TEX) was obtained by nitrolysis of 1,4-diformyl-2,3,5,6-tetrahydroxypiperazine reaction using a mixture of fuming nitric acid and concentrated sulfuric acid. The optimal process temperature was 54–56°C. The yield of the synthesis depends inter alia on the rate the reactants are introduced into the reaction medium and on the time of conditioning of the reaction mixture. A maximal yield of ca. 40% was achieved at the reactant addition time of 2 h and conditioning time of 2 h. None of the other nitrating mixtures examined proved superior to the conventional nitrating mixture. The product was examined by high-performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), and differential scanning calorimetry (DSC) techniques and the results are reported.     

Effect of Severity on Hydrotreating of Demetallized Oil Monitored by 1H-NMR Spectroscopy

Abstract

A study on aromatic hydrogenation of demetallized oil has been carried out using a commercial catalyst under pilot plant reaction conditions similar to those found in industrial processes. The feedstock was contacted with the catalysts in a trickled bed reactor unit at 330°C, 350°C, and 370°C. A combination of physicochemical characterization of feed and products and ¹H-NMR spectra was used to monitor changes in the aromatic fractions caused by variation in reaction temperature. Analysis of the ¹H-NMR spectra, along with the quantitative variation in the areas of the resonance lines, showed that the diaromatics with relatively long alkyl changes present in the lightest distillation cuts of the products were highly hydrogenated. In contrast, smaller changes in aromaticity in the heaviest fractions were observed under the same conditions. A limit of about 2 wt% of the integrals corresponding to the diaromatic+ species suggests a thermodynamical limitation of hydrogenation under the studied reaction conditions.     

Prediction of Caged Polyaza Polynitroamine (Tetracyclo-HMX) as Energetic Compound

By fusing four HMX rings into a cage, a powerful nitroamine explosive was predicted. The heat of formation (HOF) of hetero pentacyclo-icosane nitro compound of dodecanitrododecaza-pentacyclo[9.5.1.1^3,9. 1^5,15. 1^7,13]icosane (DNDAPI or, alternatively, tetracyclo-HMX) was obtained by using density functional theory B3LYP method with 6-31G? basis set. The isodesmic reactions designed for the evaluation of HOF keep most of the basic ring structures of the title compounds and thus ensure the credibility of the result. The value of HOF is 1394.59 kJ/mol. The predicted detonation velocity of the title compound is 10.6 km/s and detonation pressure is 56.8 GPa, even at 90% of its theoretical density. These values are much larger than those of the widely used 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX), indicating that DNDAPI is a promising candidate of high energy material. The dissociation energy for the N-NO₂ bond in the cage skeleton of the title compound is 125.36 kJ/mol.     

Effects of low-salinity water coupled with silica nanoparticles on wettability alteration of dolomite at reservoir temperature

Wettability alteration in porous media is one of the mechanisms for enhancing oil recovery through injecting low-salinity water into carbonate reservoirs, in which active ions can remove the carboxylic oil component from the rock surface, altering the rock's wettability toward a water-wet condition. This study investigated the concomitant effects of low-salinity water and hydrophilic SiO₂ nanoparticles on oil-wet dolomite rock. Results revealed that low-salinity water coupled with hydrophilic nano-SiO₂ in oil-wet dolomite rock remarkably affected the wettability alteration of the rock, showing that the simultaneous presence of ions in water and hydrophilic nano-SiO₂ led to considerable wettability alteration compared with using just low-salinity water.     

定量核磁共振氢谱法测定苄基喹啉季铵盐产品中二聚体的含量

目的 苄基喹啉季铵盐(BQC)是一种常用的酸化缓蚀剂,其合成中的副产物苄基喹啉季铵盐二聚体(BQD)被发现对金属腐蚀具有更高效的缓蚀作用。为了明确合成产物中BQD的有效含量,建立了测定BQD含量的定量核磁共振氢谱法。方法 通过合成并提纯得到了BQD,使用元素分析、质谱、核磁、红外等手段对其结构进行表征;以氘代氯仿作溶剂,选择化学位移在δ 12附近的BQD单峰和化学位移在δ 5附近的内标物二溴甲烷的单峰作为定量峰,根据两峰的面积之比,计算得到产物中BQD的有效含量。结果 合成产物中BQD质量分数为11.6%,与加入BQD纯品的比对实验结论基本一致。结论 建立的核磁共振氢谱内标法是一种简便、快捷、结果可靠的BQD含量检测方法。     

Research on paleo-fluid sources and hydrocarbon preservation conditions in marine carbonates in the central Yangtze, China

87Sr/86Sr,δ18O andδ13C ratios of calcite,dolomite,gypsum filling vugs and fissures in marine carbonates and their host rocks from the Sinian to the middle Triassic,are employed to trace the possible source and migration path of key fluids related to development of hydrocarbon,hydrocarbon preservation condition are then discussed further.Comprehensive research,based on the paleo-fluid,the property of formation water and the deformation intensity etc.,indicates that the preservation conditionsin the Shizhu synclinorium zone and Fangdoushan anticlinorium zone are the most predominant in the central Yangtze.Three sets of fluid systems in the Shizhu synclinorium zone are identified.Little fluid exchange occurs between the upper-middle fluid system and the lower fluid system,so two independent preservation units have developed.Both the Permian and the Triassic in the upper preservation unitsand the Dengying Formation of the Sinian and the lower Cambrian in the lower preservation units havegood preservation conditions.The preservation condition in the lower association(Z-S)located in the Huaguoping synclinorium zone in the western Hubei and Hunan is better than that in other tectonic units,where the fluids in the lower association migrated vertically across strata when the fluid isolating intervalswere destroyed,the regional seals are absent and the conditions for the preservation of hydrocarbon accumulations are totally destroyed.The preservation condition is increasingly more favorable from the western Jiangxi and Hunan to the western Hubei&eastern Chongqing on the whole.