枯草芽孢杆菌提高原油采收率的物模驱油实验

针对目前常规采油开采技术的限制和原油采收率较低等问题,本研究采用单因素法对一株从油污中分离的枯草芽孢杆菌(Bacillus subtilis 32811)代谢产生物表面活性剂的发酵条件进行优化并进行微生物驱油实验。优化条件实验确定了以葡萄糖为唯一碳源,最佳的无机培养基配方(g/L):ρ(C_6H_(12)O_6)30.0,ρ(NH_4NO_3)1.0,ρ(KH_2PO_4)4.1,ρ(Na_2HPO_4·12H_2O)14.3,ρ(MgSO_4)0.096,ρ(CaCl_2)0.0008,ρ(FeSO_4)0.0011,ρ(C_(10)H_(16)N_2Na_2O_8)0.0015。发酵液表面张力从65mN/m降至25mN/m。通过微生物对原油降解的物模驱油实验,得出原油出现乳化及原油重质组分含量明显降低的结果。物模驱油实验中分别注入发酵液及先注入微生物再注入无机培养液能提高原油采收率26.1%和31.4%。说明枯草芽孢杆菌有利于提高剩余油的采收率,具有良好的应用前景。     

Effect of Protolysis Reactions on the Shape of Chronopotentiograms of a Homogeneous Anion-Exchange Membrane in NaH<Subscript>2</Subscript>PO<Subscript>4</Subscript> Solution

Single-pulse and double-pulse chronopotentiograms of a homogeneous anion-exchange membrane AX in 0.02 M solutions of NaCl (system 1) or NaH₂PO₄ (system 2) have been recorded in underlimiting and overlimiting current modes. It has been found that in the case of exceeding the limiting current (i > i _lim ^Lev ) calculated using the convection–diffusion model, the time required to establish a steady state in system 2 increases by more than an order of magnitude compared to system 1. The slow growth of the potential drop is due to a gradual transition of the membrane from the form in which the main counterion is H₂PO ₄ ^– to the HPO ₄ ^2– form. This transition is due to the deprotonation of a part of H₂PO ₄ ^– ions forming HPO ₄ ^2– and protons as they enter the membrane. The participation of H⁺ in charge transfer in the depleted diffusion layer at a given current density causes a lower value of the potential drop than in system 1 for the same i/i _lim ^Lev ratio. In intense current regimes, chronopotentiograms of system 2 exhibit two inflection points. The first point corresponds to the classical Sand transition time and is due to reaching the limiting current of H₂PO ₄ ^– ions (the main charge carrier for i < i _lim ^Lev ) in the depleted diffusion layer. The second point is associated with a critical current that can be called the second limiting current in the system with NaH₂PO₄ and has no analogue in the system with NaCl. This current, which is approximately 2i _lim ^Lev , corresponds to the state when the membrane is completely transformed into the HPO ₄ ^2– form. Meanwhile, the source of protons due to the transformation of H₂PO ₄ ^– into HPO ₄ ^2– ions as they enter the membrane is exhausted. After reaching this critical value of the potential drop, either the HPO ₄ ^2– deprotonation reaction to give triply charged PO ₄ ^3– ions in the membrane or the water splitting on fixed groups located at the membrane/solution interface may occur.     

PRECIPITATION OF IRON,SODIUM, AND POTASSIUM IMPURITIES FROM SYNTHETIC SOLUTIONS MODELING SPENT ACID STREAMS FROM A CHEMICAL COAL CLEANING PROCESS

ABSTRACT

Experiments on treating model spent acid streams from a chemical coal cleaning process by double salt precipitation indicated that simple heating of solutions containing Fe₂(SO₄)3, Na₂SO₄, and K₂SO₄ caused jarosite (KFe₃(SO₄7)₂(OH)₆) to form preferentially to natrojarosite (NaFe₃(SO₄)₂(OH)₆), and precipitate yields were higher than when Na₂SO₄ was the only alkali sulfate present. Virtually all of the K, about 90% of the Fe, and about 30% of the SO₄ ^2? could be precipitated at 95°C, while little or no Na was removed. However, simply heating Fe₂(SO₄)₃/Na₂SO₄ solutions up to 95°C for <12 hours did not produce adequate precipitate yield's. When Na was the only alkali metal present, the Fe concentration in the solution had to be increased to avoid formation of undesirable iron compounds. Increasing the Fe concentration to about 6 g/L by adding excess Fe₂(SO₄)₃ suppressed the formation of undesirable iron salts and increased natrojarosite yields significantly, but the amount of precipitate obtained was less than half of the theoretical yield based on concentrations of the ions in solution. When either CaCO₃, Ca(OH)₂ or ZnO was used to maintain a pH value of 1.5 in solutions of Na₂SO₄/Fe₂(SO₄)₃ containing excess Fe, precipitate yields increased dramatically at 80 and 95°C. When CaCO₃ was used, the precipitate consisted of natrojarosite and gypsum (CaSO₄·2H₂O). In one of the tests, at least 99% of the Fe and 50-75% of the Na was removed. Complete removal of Na in those tests was probably precluded by hydronium ion substitution for the Na     

Effect of composition of tungsten(VI) and phosphorus(V) peroxoheteropoly derivatives on the efficiency of epoxidation of olefins under phase-transfer catalysis conditions

Epoxidation of hexene-1 and cyclohexene in the systems H₂WO₄/H₂O₂-H₂O/H₃PO₄ was studied under the phase-transfer catalysis conditions depending on the ratio between the reactants Na₂WO₄ and H₃PO₄ (in the presence of excess H₂O₂) and pH of the water phase. The interrelation between the pH of the aqueous phase, the composition of phosphatooxoperoxotungstate ions formed, and the catalytic activity of the systems was established. The complexes Q₃[PO₄{WO(O₂)₂}₄] and Q₂[HPO₄{WO(O₂)₂}₂], where Q⁺ is the lipophilic cation of a phase-transfer agent whose nature can have a noticeable effect on the composition of peroxoheteropoly compounds formed, exhibited the highest activity. To achieve the maximum catalytic activity, it is necessary to maintain the stoichiometric reactant ratio corresponding to the composition of peroxo complexes that prevail in a given pH range.     

Oxidative desulfurization of catalytically cracked gasoline with hydrogen peroxide

Hydrogen peroxide desulfurization at 50°C of a catalytically cracked gasoline fraction containing methyl- and dimethylthiophenes and traces of benzothiophene and dibenzothiophene and boiling in the range of IBP-70°C in the presence of transition metal compounds Na₂MoO₄, Na₂WO₄, VOSO₄, and [Cu(NH₃)₄]CO₃ followed by adsorption on alumina has been studied. The successive oxidation of the hydrocarbon fraction in the presence of the copper and molybdenum compounds under phase transfer conditions ensures the removal of up to 96% of total sulfur.     

金属助剂对Ni2P/SBA-15催化剂结构及二苯并噻吩加氢脱硫性能的影响

 以介孔分子筛SBA-15为载体,硝酸镍为镍源,磷酸氢二铵为磷源,采用共浸渍法制备了 P/Ni 摩尔比为0.8的 Ni₂P/SBA-15催化剂,然后添加 Li、Na、K、Mg、Ca、Sr 和 Ba 等金属助剂,制备了一系列不同金属助剂的M-Ni₂P/SBA-15(其中M为 Li、Na、K、Mg、Ca、Sr 和 Ba)催化剂。采用 XRD 对该系列催化剂的结构进行了表征,并以二苯并噻吩质量分数为1%的二苯并噻吩/十氢萘溶液为模型化合物,在微型固定床反应器上评价它们的加氢脱硫(HDS)性能。结果表明,M-Ni₂P/SBA-15催化剂的活性相为 Ni₂P。不同的金属助剂对催化剂性能的促进作用不同,其中碱土金属Ca能够明显地提高 Ni₂P/SBA-15催化剂的 HDS 活性,Ca 质量分数为3.5%的Ca-Ni₂P/SBA-15催化剂的 HDS 活性最好。在反应压力3.0 MPa、反应温度360℃的条件下,3.5%Ca-Ni₂P/SBA-15催化剂催化的二苯并噻吩 HDS 的转化率达到98.6%。不同金属助剂以不同方式影响加氢脱硫反应的机理。       

无导向剂快速合成小晶粒Y分子筛

考察了无有机模板剂、无导向剂条件下合成Y分子筛体系的n(Na₂O)/n(SiO₂)、n(SiO₂)/n(Al₂O₃)及硅源对Y分子筛结晶过程及其粒径的影响。结果表明,增加n(Na₂O)/n(SiO₂)有利于促进Y分子筛的形成,但同时也加速Y分子筛的转晶。Y分子筛的粒径随n(Na₂O)/n(SiO₂)的增加而减小,n(Na₂O)/n(SiO₂)=0.6和0.88的合成体系在100℃下反应3 h后,所得产物的平均粒径分别为0.4和0.3μm,n(Na₂O)/n(SiO₂)=1.04时形成的小晶粒Y分子筛易发生团聚而形成大颗粒。Y分子筛的n(SiO₂)/n(Al₂O₃)随n(SiO₂)/n(Al₂O₃)的增加而减小。n(SiO₂)/n(Al₂O₃)减少时,Y分子筛的粒径分布变宽(0.2～0.7μm)。以硅溶胶或固体纳米SiO₂为硅源合成所得Y分子筛的粒径分布较窄（0.3～0.5μm）,而以硅酸钠为硅源合成所得Y分子筛的粒径分布较宽(0.2～1.0 μm)。     

硫酸盐热化学还原生成H2S实验研究

H_2S作为有毒的酸性气体,在稠油注汽热采过程中主要由硫酸盐热化学还原(TSR)产生。通过实验探究CaSO_4、Na_2SO_4、MgSO_4和Al_2(SO_4)_34种不同硫酸盐发生TSR反应生成H_2S的作用机制及影响。实验结果表明:(1)水是产生TSR反应的必要条件,固态硫酸盐并不能引发TSR反应;(2)硫酸盐的溶解度决定TSR反应速率,溶解度越高,反应速率越快;(3)水溶性硫酸盐的金属阳离子电荷数决定TSR反应的难易程度,电荷数越多,反应越容易进行。     

Poly (3-Hydroxybutyrate) Production from Crude Oil by Haloarcula sp. IRU1: Optimization of Culture Conditions by Taguchi Method

Abstract

Petroleum contamination is a widespread and well-recognized global environmental threat to human health and ecosystems. Haloarcula sp. IRU1 was cultivated axenically in synthetic liquid media with crude oil as sole carbon and energy source. After 5 days' incubation, cell dry weight (CDW) and poly (3-hydroxybutyrate) (PHB) production were studied by conventional methods. The optimized conditions for the maximum production of PHB were temperature 47°C, crude oil 2%, yeast extract 0.4%, and NaH₂PO₄, 0.016% as carbon, nitrogen, and phosphorus sources, respectively. In conclusion, Haloarcula sp. IRU1 can biodegrade crude oil and use it as a carbon source for PHB production.     

Hexammine metal perchlorates as energetic burning rate modifiers

Abstract

Four transition metal hexammine perchlorates namely, [Cu(NH₃)₆](ClO₄)₂, [Co(NH₃)₆](ClO₄)₂, [Ni(NH₃)₆](ClO₄)₂ and [Zn(NH₃)₆](ClO₄)₂ have been prepared, characterized and used as ballistic modifiers in the combustion of hydroxy terminated polybutadiene (HTPB)-Ammonium perchlorate (AP) composite solid propellants. Burning rate was considerably enhanced with [Co(NH₃)₆](ClO₄)₂ and [Cu(NH₃)₆](ClO₄)₂ whereas moderately with [Ni(NH₃)₆](ClO₄)₂ and [Zn(NH₃)₆](ClO₄)₂ at low concentration (2% by wt). [Co(NH₃)₆](ClO₄)₂ was found to accelerate the burning rate by three fold at two percent concentration and it can be exploited as potential energetic burning rate modifier for HTPB-AP propellants. Further, ignition delay studies showed that the deflagration of propellants and AP was accelerated by these additives.     

Study of methanol steam reforming and ethanol conversion in conventional and membrane reactors

Research results for methanol steam reforming and ethanol conversion in a conventional and a membrane reactor in the presence of Ru–Rh/DND, LiZr₂(PO₄)₃, and Li_1.1Zr_1.9In_0.1(PO₄)₃ catalysts have been described. The samples have been characterized by X-ray diffraction, scanning electron microscopy, and the BET method. The study of the catalytic properties of the catalyst composites has shown that the Ru–Rh/DND catalyst mostly mediates the dehydrogenation process, while LiZr₂(PO₄)₃ and Li_1.1Zr_1.9In_0.1(PO₄)₃ exhibit activity in both the dehydration and dehydrogenation reactions. The membrane process with a Pd–Ru alloy membrane provides a 20% increase in the hydrogen yield.     

The Effect of Pd Precursors on the Catalytic Activity of a Pd/Al2O3 Catalyst for Cumene Hydroperoxide Hydrogenation

Abstract

Abstract Pd/Al₂O₃ catalysts were prepared by wet impregnation using K₂PdCl₄, (NH₄)₂PdCl₄, and Pd(NO₃)₂ as precursors. All catalysts were characterized by means of inductively coupled plasma-atomic emission spectroscopy (ICP-AES), temperature-programmed reduction (TPR), X-ray diffraction (XRD), and CO chemisorption. The results obtained in the hydrogenation of cumene hydroperoxide (CHP) to α-cumyl alcohol (CA) showed that Pd/Al₂O₃ catalyst prepared from Pd(NO₃)₂ exhibited the highest turnover frequency (TOF) value and the greatest deactivation extent, whereas Pd/Al₂O₃ catalyst prepared from (NH₄)₂PdCl₄ displayed the lowest TOF value but the best stability.     

Kinetics and mechanism of thermolysis of hexammine metal perchlorates

Abstract

The thermal decomposition studies on four transition metal hexammine perchlorates, viz. [Cu(NH₃)₆](CIO₄)2, [Co(NH₃)₆](CIO₄)₂, [Ni(NH₃)₆](CIO₄)₂ and [Zn(NH₃)₆](CIO₄)₂. have been carried out using Thermogravimetry (TG), derivative thermogravimetry (DTG) and explosion delay (D_E) measurements. Although, the kinetics of thermolysis of these complexes were evaluated by fitting isothermal TG data in nine mechanism-based kinetic models but the contracting area (n=2) and contracting cube (n=3) give the best fits. It has been observed that deammination takes place at lower temperatures and ammine metal perchlorates and/or metal perchlorates are formed as intermediates which decompose to metal oxides at higher temperatures. The decomposition pathways for hexammine metal perchlorates have also been suggested.     

催化裂化烟气脱硫、脱氮吸附剂的初步研究

 在微型连续床式反应装置上,考察了催化裂化催化剂吸附烟气中 SO₂、NO_x的性能。当SO₂、NO_x的体积分数分别为1800和1900 μL/L、反应温度为220℃、微正压操作时,新鲜吸附剂90%的SO₂脱除率维持在140~200s,70%的NO_x脱除率维持在220~470s;吸附容量为11.4~16.2 mg/g。SO₂、NO_x与吸附剂以物理吸附和化学吸附方式相作用;吸附运转剂表面的S和N分别以SO^2-₄和 NO^-₃存在。     

A Novel Approach for Environmentally Friendly Production of Single Cell Protein From Petrochemical Wastewater Using a Halophilic Microorganism in Different Conditions

In this study, biodegradation of petrochemical wastewater and production of single cell protein from it as carbon source was investigated using several process parameters. The process parameters such as carbon source, type of phosphorus source, phosphorus source concentration, type of nitrogen source, nitrogen source concentration, and temperature were considered. In order to investigate the influence of process parameters, a factorial design using Taguchi method was applied with six factors at four levels. The optimum medium composition for single cell protein production was found to contain petrochemical wastewater 8%, peptone 0.2%, and K₂HPO₄ 0.008% at temperature 37°C. The percentage ratio of single cell protein to cell dry weight in optimal conditions was 76.4%. In conclusion, Haloarcula sp. IRU1 can degrade petrochemical wastewater and use it as carbon source for single cell protein production in different conditions.     

Effect of sulfide pollution on the stability of Cu–Al–5Ni alloy in 3.5% NaCl solution

The stability of Cu–Al–5Ni ternary alloy used in the manufacture of NaCl and Na₂SO₄ from the Lake Qaroun in Egypt was investigated in 3.5% NaCl in the presence of sulfide ions. The electrochemical reactions of Cu–Al–5Ni electrode in the test solutions were studied using electrochemical impedance spectroscopy measurements. In addition surface examination and morphological studies were applied using scanning electron microscopy (SEM) and energy dispersive analysis of X-rays (EDAX). The results of impedance measurements at open circuit potential have shown that the overall impedance of the system decreases with the increase in sulfide ion concentration and increases with immersion time due to continuous growth of the passive film on the alloy surface. The EDAX analysis showed the presence of copper, aluminum and nickel compounds, Cu-oxides, Cu-chlorides and Cu₂S on the alloy surface.     

硫化行为对Ni2P/SBA-15催化剂结构和加氢脱硫性能的影响

以介孔分子筛SBA-15为载体、硝酸镍为镍源、磷酸氢二铵为磷源,等体积浸渍法制备了Ni2P/SBA-15催化剂前驱体,然后在H2流中程序升温还原,得到Ni2P/SBA-15催化剂,再用CS2溶液对催化剂进行了硫化处理,制备出了硫化态xCS2-Ni2P/SBA-15催化剂。采用XRD、N2吸附-脱附、XPS对催化剂的结构进行了表征,对催化剂的二苯并噻吩加氢脱硫活性进行了评价,考察了硫化条件对催化剂结构和二苯并噻吩加氢脱硫催化活性的影响。结果表明,xCS2-Ni2P/SBA-15催化剂的物相有Ni2P、Ni12P5、Ni3S2,催化剂的比表面积随硫化溶液中CS2质量分数的增加有一定程度的增加,催化剂表面的Ni以Niδ+和Ni 2+形式存在,P以Pδ-和P5+形式存在。采用5%CS2硫化溶液硫化的催化剂对二苯并噻吩加氢脱硫具有最高的催化活性,380℃时二苯并噻吩的转化率可达99.3%。硫化过程形成的Ni3S2活性物相对二苯并噻吩的转化和直接脱硫都有利。     

The decomposition pathways of ammonium dinitramide on the basis of ab initio calculations

Quantum chemistry calculations incorporating solvent effects were used to investigate the decomposition pathways in molten Ammonium dinitramide (ADN). Optimized structures for reactants and products were obtained at the CBS-QB3//ωB97XD/6–311++G(d,p)/SCRF = (solvent = water) level of theory, considering the isomers ADN_I (NH₄–N(NO₂)₂) and ADN_II (NH₄–ON(O)NNO₂) and the four ADN_II conformers, which are minimal clusters of anion and cation in molten ADN. In the initial stage of decomposition, the ADN_II decomposes to NO₂? and NNO₂NH₄. Following the initial decomposition, NNO₂NH₄? decomposes to N₂O, NH₃, and OH?, and the OH? combines NO₂? to yield HNO₃. This decomposition can be written using one global formula: ADN → N₂O + NH₄NO₃ (NH₃ + HNO₃).     

The influence of nature of the anion in tetraalkylammonium salts on the crystallization of zeolite beta

The influence of the nature of anion X in the tetraethylammonium salt [N(C₂H₅)₄]X on the selectivity of the formation zeolite beta in the SiO₂-Al₂O₃-Na₂O-[N(C₂H₅)₄]X-H₂O system under hydrothermal conditions without seed crystals was studied. It was shown that the test anions can be arranged in the following series in terms of the preferential formation of zeolite beta: F^?, SO ₄ ^2? , PO ₄ ^3? , (CH₂COO) ₂ ^2? > HCOO^? > (COO) ₂ ^2? , CH₃COO^? ? Cl^? ～ NO ₃ ^? ? Br^? ? I^? ? ClO ₄ ^? . In particular, the fluoride and the anions of polybasic acids facilitate the formation of zeolite, whereas perchlorate, bromide, and iodide ions inhibit its formation. The experiments showed that anions facilitating the formation of zeolite beta make it possible to synthesize zeolite within the same broad range of chemical composition of the reaction mixture as in the case of [N(C₂H₅)₄]OH. The reveled classification of anions into groups coincides with their categorization by Samoilov into anions with positive and negative hydration.     

Colloidal silver complex as an alternative to sulphur dioxide in winemaking

The use of sulphur dioxide in the food industry has come increasingly into question because it can lead to pseudo-allergies. The aim of this work was to study the effectiveness of a colloidal silver complex (CSC) as an antiseptic instead of SO₂ in both white and red winemaking. We show that the CSC at doses of 1 g/kg of grape is an effective antiseptic, able to control acetic acid and lactic acid bacteria development, allowing the growth of Saccharomyces cerevisiae at rates similar to those observed with SO₂, up to sugars were exhausted. Silver concentration in finished white and red wines, 18.4 μg/L and 6.5 μg/L, respectively, was well below the legal limits. Wine composition was slightly affected, but CSC wines had a lower alcoholic degree and acetaldehyde content than SO₂ wines. CSC is a promising antiseptic for wine industry, although a major drawback, its lack of antioxidant activity, should be considered.