Ecological Behavior of Linear Alkylbenzene Sulfonate (LAS) in Soil-Plant Systems

More and more linear alkylbenzene sulfonate (LAS) has contaminated the water and soil ma pollution discharge, making it important to identify the ecological behavior and toxicity of LAS so as to carry out measures that will reduce its negative effects on the ecosystem. The ecological behavior of LAS. including degradation, migration, and plant uptake, in both soil-paddy rice and soil-soybean systems was studied. Reduction of LAS in pot and field plots followed the first order reaction kinetics with degradation half-lives of 35-50 days with LAS decreasing to very low concentrations after a season of crop growth. Strong migration ability for LAS was found and the breakthrough time in a 1.5 in soil monolith was significantly shortened to 23 days by preferential flow. Leachate volumes of soil-paddy and soil-soybean systems at preferential breakthrough were much different, while the leachate volumes at equilibrium governed by soil adsorption/desorption processes were very similar. Significant uptake of LAS in both paddy rice and sovbeans was observed in pot and field experiments (P < 0.05). In aquatic culture, 20 μg mL-1 and above of LAS significantly inhibited the growth of paddy seedlings (P < 0.05). The critical concentration for LAS in soil inhibiting the growth and yield of paddy was 160 μg g-1; when higher, there was a strong negative influence, with decreases in height, spike length, and production, when lower than 80 μg g-1, paddy growth was stimulated. There was little effect of LAS on soybeans.

Effect of Dermal Exposure to Paraphenylenediamine and Linear Alkylbenzene Sulphonate in Guinea Pigs

To study the effects of paraphenylenediamine （PPD） and linear alkylbenzene sulphonate （LAS） alone and in combination on the skin. Methods Forty-eight guinea pigs were divided equally into 4 groups and exposed to PPD （4 mg/kg）, LAS （12 mg/kg） and PPD （4 mg/kg） plus LAS （12 mg/kg） for 30 days. The biochemical parameters such as acid phosphatase, gtutathione-s-transferase, glutathione peroxidase, glutathione, lipid peroxidafion and histamine contents in exposed skin were estimated. The histopathological examination of the exposed skin was also carried out. Results The skin enzymes, lipid peroxidation, and histamine increased while glutathione decreased in skin. The simultaneously exposed group showed additive toxic effects. The histopathological examination showed severe hyperkeratosis, thickening of collagen fibres and vacuolisation of epidermal cells in PPD plus LAS exposed skin. Conclusion The findings of the present study suggest that simultaneous exposure to PPD and LAS has additive toxic effects.

Kinetic Model of Hydrogenation for Removal of Trace Olefins from Alkylation Mixture Formed during Linear Alkylbenzene Synthesis

Through the hydrogenation experiments for removal of olefin impurities in effluent mixture obtained from alkylation reactor for linear alkylbenzene synthesis, the reaction kinetics was studied. The experimental results showed that the catalytic activity of Pd/Al2 O3 among four kinds of catalysts was the highest, and the olefin conversion reached 100%when the reaction temperature was higher than 140 ℃. The kinetic model was established through parameters estimation.The experimental validation of the kinetic model showed that the kinetic model had higher simulation accuracy. The results of prediction by the kinetic model indicated that with the intensification of reaction conditions, the olefin conversion would increase and the bromine index of the linear alkyl benzene would decrease. Under the conditions covering a WHSV of 2.0 h^(-1),a temperature of 90 ℃, and a hydrogen partial pressure of 1.5 MPa, the olefin conversion was 99.67%, and the bromine index of the linear alkyl benzene could be reduced to less than 20.00 mgBr/(100 g).

Simulation of Suspension Catalytic Distillation for Synthesis of Linear Alkylbenzene

Suspension catalytic distillation (SCD) has been developed recently as an innovative technology in catalytic distillation. In this paper, a brief introduction to SCD is given and an equilibrium stage (EQ) modei is developed to simulate this new process for synthesis of linear alkylbenzene (LAB) from benzene and 1-dodecene. Since non-ideality of this reaction systern is not strong, EQ modei developed could be applied to it successfully. Simulation results agree well with experimental data, and indicate some characteristics of SCD process as an advanced technology for the production of LAB: 100% conversion of olefins, low temperature (90-100℃) and low benzene/olefin mole ratio.

Surfactant Linear Alkylbenzene Sulfonate Effect on Soil Cd Fractions and Cd Distribution in Soybean Plants in a Pot Experiment

A pot experiment was conducted to study the effect of an anionic surfactant linear alkylbenzene sulfonate(LAS) application on cadmium(Cd)fractions in soils and Cd distribution in different tissues of soybean(Glycine max)plants as well as soil pH.Soil samples were treated with three levels of Cd(0,5,and 10 mg kg^(-1))and five levels of LAS(0,5, 15,50,and 100 mg L^(-1)).Results indicated that compared to the control soils(no Cd and no LAS treatment),soil pH increased and available Cd decreased in the soil treated with external Cd and watered with LAS solutions.Meanwhile, soil exchangeable Cd and Cd bound to carbonates decreased;Cd bound to amorphous iron and manganese oxides and Cd bound to organic matter increased.In addition,LAS application could reduce enrichment of Cd in soybean plants, resulting in decreased Cd in the soybean plants.Thus,suitable LAS application could decrease bioavailability and mobility of soil Cd.

OXIDATION OF ALKYLBENZENES CATALYZED BY IRON( Ⅱ,Ⅲ)-1,10-PHENANTHROLINE AND 2, 2'-BIPYRIDINE COMPLEXES

Oxidation of alkybenzenes PhCH_2R(R=H, CH_3, C_2H_5 and n-C_3H_7) under 1 atm. of O_2 or air catalyzed by iron(Ⅱ, Ⅲ)-2,2'-bipyridine and 1,10-phenanthroline complexes, affords the aryl-substituted ketones and alcohols with the conversion of 15.00％～34.58％ containing of 97.60％～99.80％ ketones and alcohols. The turnover numbers of these catalysts are over 3500 mol-cat. ^(-1)for 3.5 h.

Linear Alkylbenzene Sulfonates in the Groundwater and Surface Waters： Ergene Basin Case Study

Ergene Basin is one of the most important industrial centers due to the geographical location in Turkey. Uncontrolled and rapidly increasing industrialization brings together a large number of environmental problems in the basin. In this study, pollution was investigated in the water samples taken at time intervals and different parts of groundwater and surface water resources located within Ergene Basin by methylene blue anionic surfactants （MBAS） analysis method. Turbidity, temperature, pH, electrical conductivity （EC）, concentrations of total P and linear alkylbenzene sulfonates （LAS） were simultaneously determined in the investigated water resources. The results were compared with the Turkish Water Pollution Control Regulation specified in the Quality Criteria of the Inland Water Resources according to their class. The total P and LAS concentrations of surface waters are generally higher than groundwater. In terms of LAS concentrations, the groundwater is Ⅰ-Ⅱ class and the surface water is Ⅱ-Ⅳ class.

Two Copper Complexes Based on Pyrazole-3-carboxylic Acid as Heterogeneous Catalysts for Highly Selective Oxidation of Alkylbenzenes

Two new copper complexes based on pyrazole-3-carboxylic acid （H2pca） ligand, Cu（Hpca）2（H2O）2？2H2O （1） and Cu2（pca）2（H2O）4 （2） have been synthesized and fully characterized by single-crystal X-ray diffraction （SXRD）, infrared spectroscopy （IR）, thermal gravity analysis （TGA）, powder X-ray diffraction （PXRD） and elemental analyses. Complex 1 is mononuclear while complex 2 shows a dinuclear structure. Complex 1 crystallizes in the monoclinic system, space group P21/c with Z = 2, a = 6.5591（5）, b = 21.696（2）, c = 4.9486（2） ？, V = 680.94（9） ？3, F（000） = 366, Dc = 1.745 g/cm3, μ = 1.650 mm-1, the final R = 0.0340 and wR = 0.0792. Complex 2 crystallizes in the monoclinic system, space group P21/n with Z = 2, a = 5.1935（4）, b = 9.6052（7）, c = 12.7347（9） ？, V = 634.44（8） ？3, F（000） = 420, Dc = 2.195 g/cm3, μ = 3.404 mm-1, the final R = 0.0305 and wR = 0.0653. The three-dimensional frameworks of two complexes are formed by the O？H？？？O and N？H？？？O hydrogen bonding interactions. Notably, two copper complexes are further used as catalysts in the oxidation of alkylbenzenes using t-butylhydroperoxide （TBHP） as the oxidant and they exhibit excellent catalytic performance （Conv. up to 98.9%, Sele. up to 98.7%）.

Synthesis of Linear Alkylbenzene in a Novel Liquid-Solid Circulating Moving Bed Reactor

For the alkylation of benzene with long-chain olefins, using Hβzeolite catalyst as replacement of HF or AlCl3 has the advantages of no corrosion, less environmental pollution, and much more 2-phenyl isomer, which has the highest biodegradability and solubility, and better detergent properties among the related isomers. The characterization of the coke shows that the deactivation of catalyst is caused by the jam of bulkier molecules, such as naphthalene, indane and linear alkylbenzenes, which are too big to move quickly in the intracrystalline pores of catalyst. The deactivated catalyst can be regenerated by benzene washing at higher temperature. To make the processes of reaction and regeneration continuous, a novel moving bed reactor is developed. Comparing with the processes with fixed bed reactors, the processes in this work have the advantages of continuous operation, low temperature, low pressure, low mole ratio of benzene to olefins, and high weight hourly space velocity.

Alkylbenzene Project in Xinjiang Approved

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全二维气相色谱测定汽油馏分中芳烃详细组成

采用全二维气相色谱-氢火焰离子化检测器(GC×GC-FID)对汽油中芳烃组分特别是C_(9+)芳烃进行了详细的定性和定量分析。全二维色谱系统采用固态调制器,一维色谱柱采用非极性二甲基聚硅氧烷固定相的色谱柱,二维色谱柱采用极性聚乙二醇固定相的色谱柱。在优化的色谱条件下,一次进样可以实现153种C_(6)~C _(12)芳烃组分的分离。汽油族组成中的芳烃在全二维谱图中呈带状分布,瓦片效应明显。考察了直馏汽油、重整汽油、催化汽油、焦化汽油、裂解汽油等不同类型组分汽油的全二维色谱的分离情况,裂解汽油中所含芳烯烃组分与烷基苯可以获得很好的分离。建立的采用内标法定量测定车用汽油中单体芳烃特别是C 9+芳烃含量方法的结果重复性和准确度良好,可以对清洁汽油生产工艺研究以及汽油产品的质量控制提供基础数据及方法支持。

Investigating the potential of using acoustic frequency on the degradation of linear alkylbenzen sulfonates from aqueous solution

The effectiveness of using acoustical （sonochemical） reactor for degradation of linear alkylbenzen sulfonate （LAS） from aqueous solution was investigated. LASs are anionic surfactants, found in relatively high amounts in domestic and industrial wastewaters. In this study, experiments on LAS solution were performed using methylene blue active substances （MBAS） method. The effectiveness of acoustical processor reactor for LAS degradation is evaluated with emphasis on the effect of treatment time and initial LAS concentration. Experiments were performed at initial concentrations of 0.2, 0.5, 0.8 and 1.0 mg/L, acoustic frequency of 130 kHz, applied power of 500 W and temperature of 18℃-20℃. At the conditions involved, LAS degradation was found to increase with increasing sonochemical time. In addition, as the concentration increased, the LAS degradation rate decreased in the acoustical processor reactor.

化学驱高效乳化提高驱油效率研究进展

综述了石油磺酸盐与重烷基苯磺酸盐的乳化性能,调研了2种表面活性剂与不同材料混合后形成的复配体系的乳化性能变化,以及乳化能力与原油采收率的关系,并对乳化驱油在油田现场的应用进行了总结与展望。

氢氟酸与烷基化油快速分离

氢氟酸(HF)烷基化是烷基苯生产的主流工艺,酸烃分离器是该工艺的关键设备之一,由于HF催化剂的高腐蚀性、高危险性,至今仍沿袭大罐沉降的分离方法,导致反应流出物停留时间长、HF储量巨大,给烷基苯装置带来巨大的安环风险。工艺介质的特殊性造成国内外对该体系快速分离的研究处于空白,本文创新开发了适用于HF和烷基化油快速分离的聚结分离器,开展了中试试验,分离器油相出口酸含量(≤0.2%)及酸相出口循环酸浓度(≥98.5%)满足工艺指标,酸烃分离速率可提高约2倍,分离器容积及HF储量缩减2/3以上,同时针对该反应体系的乳化现象,试验测算了乳化液产率及消减速率,解决了分离器内酸、烃、乳化层的多层界位分布状况不明晰的难题,对涉及HF催化工艺的升级改造具有普遍参考价值。

乙醇对烷基苯磺酸盐Gemini表面活性剂Ia水溶液性质的影响

采用TX-500型旋转滴界面张力仪和CHI900电化学工作站进行测试,研究了乙醇对烷基苯磺酸盐Gemini表面活性剂Ia水溶液性质的影响。结果发现:乙醇的加入可以使溶液体系中Ia的临界胶束浓度增大,溶液的界面张力值和Ia的胶束扩散系数降低。原因可能是因为乙醇的两亲结构可以使其通过疏水效应插入到表面活性剂之间,减小Ia分子间的距离,使Ia分子更好地分散在溶液中,更加紧密、有规律地排列在界面上,最终降低溶液体系的界面张力;但乙醇的存在对于Ia分子的聚合是不利的,不利于Ia胶束的形成,所以乙醇的加入使Ia分子的临界胶束浓度增大,Ia分子胶束尺寸变大,从而表现出较小的胶束扩散系数。

分子筛结构与直链烷基苯催化合成性能的构效关系

研究了不同拓扑结构的分子筛在直链烷基苯(LAB)催化合成反应中的构效关系,对性能较优的Y型分子筛进行了孔道和酸性调变,并进行了苯和1-十二烯烷基化催化性能评价。采用X射线荧光光谱(XRF)、X射线衍射(XRD)、NH_(3)程序升温脱附(NH_(3)-TPD)、N_(2)低温吸附-脱附等方法对分子筛物化性质进行了表征。结果表明:酸性是影响分子筛催化活性的关键因素,中强酸酸量较高的分子筛烷基化初活性及稳定性较好;具有一维孔道结构的分子筛催化合成LAB产物中2-LAB质量分数高达83.9%,但烷基化稳定性较差;多维孔道更有利于产物扩散,烷基化稳定性较好。较小孔道尺寸的分子筛直链度和2-LAB含量较高;超笼结构不利于产物择形。Y型分子筛具有较高的中强酸酸量和十二元环多维孔道结构,烷基化活性和稳定性最优,对其进行扩孔改性、增加介孔比例,寿命可提高约33%。

直链烷基苯催化剂研究进展

综述了直链烷基苯(LAB)合成中涉及固体酸和离子液体等新型催化剂的研究进展,并介绍了提高2-LAB选择性和催化剂稳定性的研究,综合对比了新型催化剂的优缺点。结果表明:负载型杂多酸、分子筛、黏土、离子交换树脂、离子液体等催化剂在烷基化反应中展现出良好的稳定性、催化活性,并在催化剂再生与产物分离方面有较好的优势,但在烷基苯的收率、选择性以及再生方面还存在许多不足。研究结果对苯与长直链烯烃烷基化反应催化剂的选型具有一定的指导意义。

烷基苯磺酸的生产技术和老化机理

首先分析了烷基苯磺酸的主要生产技术,然后对其老化机理进行分析,包括实验设计、中和值对烷基苯磺酸老化过程的影响、烷基苯磺酸老化过程中的动力学分析,以及主要的实验结论。

直链重烷基苯磺酸盐的驱油能力研究

研究了所合成的各种结构的直链烷基苯磺酸盐单剂及其复配体系在不同碱质量分数情况下对大庆四厂油 /水界面张力情况。结果表明 :对同一碳链长度的直链烷基苯磺酸盐 ,带甲基的比带乙基、异丙基和苯环上不带取代基的烷基苯磺酸盐降低界面张力的能力强 ;同样结构的十六碳链长的烷基苯磺酸盐又较其他碳链长度的烷基苯磺酸盐效果更优 ;长、短碳链的带甲基的直链烷基苯磺酸盐按一定比例复配 ,协同效应显著 ;与支链烷基苯磺酸盐复配后 ,体系的驱油能力、抗稀释性和抗Ca2 +、Mg2 +能力明显增加。

TH-06催化剂合成直链烷基苯Ⅰ-工艺条件的研究

对ＴＨ－ ０６ 分子筛催化剂上长链烯烃与苯烷基化反应过程进行了研究。首先考察了工业原料中杂质及水含量对反应的影响，并提出了原料精制的方法；然后采用精制工业原料对反应的工艺条件进行了探讨。结果表明，该催化剂活性高，稳定性好，可反复再生，且产物分布好。