Alkyl-tetralin base oils synthesized from coal-based chemicals and evaluation of their lubricating properties

Naphthenic base oil is an important lubricating base oil and very scarce in the global petroleum resources.Herein,a series of alkylated tetralin fluids similar to naphthenic base oils were produced by the alkylation of tetralin and a-olefins(n-hexene,n-octene,n-decene)with ionic liquid Et_3NHCl/AlCl_(3)as the catalyst,where the applied raw materials are totally derived from the coal chemical industry.The product composition could be controlled by adjusting the feeding ratio of tetralin and olefin.The synthetic fluids were evaluated as lubricating base oils to reveal the structure-property correlations.Their principal physicochemical and tribological properties depend on the chain-length of a-olefins and the number of alkyl groups onto the aromatic rings.Bis-(octyl-or decyl-)alkyl tetralin exhibited good properties in terms of viscosity,thermo-oxidation stability and pour point,as well as friction-reducing and anti-wear performance,showing great potential for producing naphthenic base synthetic oils from coal-based chemicals.

Research Progress in Catalytic Cracking Reaction of Tetralin and Decalin

The integrated catalytic hydrogenation and catalytic cracking process has been gradually adopted by refineries to satisfy the requirements for manufacture of light and clean petroleum products. To explore the reaction laws of hydrogenated aromatics in hydrotreated oil, the catalytic cracking reaction laws of hydrogenated aromatics have been reviewed by taking tetralin and decalin as examples of different degrees of hydrogenated aromatics. Moreover, the reaction mechanism of tetralin and decalin has been analyzed emphatically. The effects of zeolite pore structure, acid properties and process parameters on reaction laws have been analyzed carefully. It is considered that the catalytic cracking performance of hydrogenated aromatics with different hydrogen saturation degrees is quite different. It is necessary to control the hydrogenation depth, optimize the hydrocarbon composition of catalytic cracking feed materials for maximizing the yield of target products.

Selective catalytic hydrogenation of naphthalene to tetralin over a NiMo/Al2O3 catalyst

The selective catalytic hydrogenation of naphthalene to high-value tetralin was systematically investigated.A series of Al2O3 catalysts containing different active metals(Co,Mo,Ni,W)were prepared by incipient wetness impregnation.The effects of different active metals forms(oxidation,reduction,sulfuration)and reaction conditions on naphthalene hydrogenation were investigated and the catalysts were characterized by XRD,XPS,BET,NH3-TPD and SEM.Especially,Ni-Mo/Al2O3 was first used in this reactive system.The results show that the oxidative4%Ni O-20%MoO3/Al2O3 is the best catalyst for the preparation of tetralin.The conversion of naphthalene and the selectivity of tetralin can reach 95.62%and 99.75%respectively at 200℃,8 h and 6 MPa.Compared with reduced and sulfureted 4%Ni O-20%MoO3/Al2O3 catalysts,oxidative 4%Ni O-20%MoO3/Al2O3 has a well dispersed and uniform monolayer of the active metals,larger pore volume and size,and larger total acidity.NiO-MoO3/Al2O3 has a synergistic effect between NiO activity and MoO3 selectivity.

8-hydroxy-2-(di-n-propylamino)tetralin intervenes with neural cell apoptosis following diffuse axonal injury

Previous studies have reported a neuroprotective effect of 8-hydroxy-2-（di-n-propylamino）tetralin （8-OH-DPAT） against traumatic brain injury. In accordance with the Marmarou method, rat models of diffuse axonal injury were established. 8-OH-DPAT was intraperitoneally injected into model rats. 8-OH-DPAT treated rats maintained at constant temperature served as normal temperature controls TUNEL results revealed that neural cell swelling, brain tissue necrosis and cell apoptosis occurred around the injured tissue. Moreover, the number of Bax-, Bcl-2- and caspase-3-positive cells increased at 6 hours after diffuse axonal injury, and peaked at 24 hours. However, brain injury was attenuated, the number of apoptotic cells reduced, Bax and caspase-3 expression decreased, and Bcl-2 expression increased at 6, 12, 24, 72 and 168 hours after diffuse axonal injury in normal temperature control and in 8-OH-DPAT-intervention rats. The difference was most significant at 24 hours. All indices in 8-OH-DPAT-intervention rats were better than those in the constant temperature group. These results suggest that 8-OH-DPAT inhibits Bax and caspase-3 expression, increases Bcl-2 expression, and reduces neural cell apoptosis, resulting in neuroprotection against diffuse axonal injury. This effect is associated with a decrease in brain temperature.

Preparation of a highly efficient Pt/USY catalyst for hydrogenation and selective ring-opening reaction of tetralin

Ultrastable Y zeolite（USY）-supported Pt catalyst was prepared by gas-bubbling-assisted membrane reduction. The influence of reaction conditions and the metal and acid sites of catalysts on the catalytic performance of catalyst in hydrogenation and selective ring opening of tetralin, 1,2,3,4-tetrahydronaphthalene（THN）, was studied. It was found that the optimal reaction conditions were at a temperature of 280 °C, hydrogen pressure of 4 MPa, liquid hourly space velocity of 2 h^-1 and H2/THN ratio of 750. Under these optimal conditions, a high conversion of almost 100% was achieved on the 0.3 Pt/USY catalyst. XRD patterns and TEM images revealed that Pt particles were highly dispersed on the USY, favorable to the hydrogenation reaction of tetralin. Ammonia temperature-programmed desorption and Py-IR results indicated that the introduction of Pt can reduce the acid sites of USY, particularly the strong acid sites of USY. Thus, the hydrocracking reaction can be suppressed.

Design,synthesis and antifungal activities in vitro of novel tetralin compounds

Novel chiral tetralin compounds were designed and synthesized, and their antifungal activities in vitro were tested. The results showed that all of target compounds had potent antifungal activities, and were stronger than that of control compounds tetrahydroisoquinolines. The binding model of lead molecules in the active site of CYP51 of Candida albicans showed that lead compound specifically interacted with the amino acids residues in the active site, without binding with the heme of CYP51, which was different from azole antifungal drugs. The present study might afford a novel lead molecule to develop non-azole CYP51 inhihitars of fungi.

Tetralin Hydrocracking Reaction Network to Single-Ring Aromatics on Bifunctional Catalysts

Conversion of LCO(light cycle oil)to BTX(benzene,toluene,and xylene)is an economically valuable method for refineries.However,this approach still faces difficulties as the main reactions are not clearly understood.Here we study the detailed hydrocracking pathway of typical reactants,1-methylnaphthalene and tetralin,through molecular simulations and experiments to improve our understanding of the conversion process of LCO to BTX.Molecular simulations demonstrate that the rate-determining step is the isomerization pathway of six-membered ring to five-membered ring in tetralin as its activation energy(ΔEa)is the highest among all the reactions and the order ofΔEa of reactions is isomerization>ring-opening≈side-chain cleavage.The results of experiments show that with the increase in reaction depth,i.e.,through a high temperature(350-370℃)and low LHSV(4.5-6.0 h^(−1)),isomerization,ring-opening,and side-chain cleavage reactions occurred,thus improving the selectivity and yield of alkyl aromatics.

Diffusion and Adsorption of Tetralin Hydrocracking Reaction on Different Zeolites by Molecular Simulation

Three different zeolite catalysts with different pore sizes(MFI-type,BEA-type,and FAU-type zeolites)have been prepared.The influence of different zeolite catalysts on reactivity and product shape selectivity of tetralin is investigated.Clear differences are observed in the reactivity of tetralin and distribution of products achieved by different catalysts.The diffusion and adsorption behavior of the reactant tetralin and its intermediates,n-butylbenzene and 1-methylindane under the reaction conditions are simulated using molecular simulation methods.Upon combining simulation results and experimental observations,it is shown that the difference in diffusion coefficient and competitive adsorption capacity can explain the reactivity of tetralin and the selectivity of products.The steric hindrance of the MFI-type zeolite mainly limits the key step of ring opening of tetralin,leading to lower selectivity of ring-opening products.n-Butylbenzene molecules can diffuse sufficiently fast in the large pores of FAU-type zeolite and the weak adsorption capacity of n-butylbenzene leads to its insufficient cracking.In addition,it also explains the reason that the BEA-type zeolite has the best BTX selectivity,because it can satisfy both good ring-opening activity and sufficient butylbenzene cracking depth.

Optimizing support acidity of NiMo catalysts for increasing the yield of benzene, toluene and xylene in tetralin hydrocracking

To enhance the yields of benzene,toluene,and xylene in tetralin hydrocracking,the effect of the support acid properties of NiMo catalysts on hydrocracking performance of tetralin were investigated in this study.NaY zeolites were modified by hydrothermal treatment to form USY zeolites at different temperatures and adjust the type and amount of acid.In addition,H-Beta was loaded into the USY to further adjust the acidic properties of the catalysts.The result shows that when the total B acid content of the catalyst is maintained between 150 and 200μmol·g^(-1),the total acid amount is maintained between 1.7 and 1.9 mmol·g^(-1),and the L/B(L and B acids)ratio is maintained between 1.5 and 2,the catalysts have favorable performances on tetralin hydrocracking.Under this condition,the catalysts have a yield of benzene,toluene,and xylene higher than 30 wt%and a selectivity for benzene,toluene,and xylene higher than 35%.The tetralin conversion is greater than 85 wt%.The AB6 catalyst obtains the best hydrocracking effect with the conversion of tetralin reaching 90.24 wt%,the yields of benzene,toluene,and xylene reaching 33.58 wt%,and the selectivity of benzene,toluene,and xylene reaching 37.21%,respectively.

ZSM-5/USY/Beta分子筛催化剂对四氢萘加氢裂化制备BTEX的性能研究

分别采用ZSM-5、USY、Beta 3种分子筛通过等体积浸渍法制备了NiMo/ZSM-5、NiMo/USY、NiMo/Beta 3种催化剂,分别标记为cat-1、cat-2、cat-3。利用XRD、NH3-TPD、SEM对催化剂进行表征分析,在固定床反应器上以四氢萘作为模型化合物,研究其加氢裂化制备BTEX的催化性能,考察了四氢萘加氢裂化的工艺条件,并探讨了加氢裂化机理。结果表明,Beta分子筛制备的催化剂cat-3金属组分颗粒大小均匀,呈现出高度分散的状态,并且酸量适中。在反应温度为400℃、氢油比为600、反应压力为4MPa、2h-1空速的最佳反应条件下,与cat-1、cat-2相比,cat-3具有最佳的四氢萘转化率和BTEX选择性,分别高达95%和70%左右。

HDS of dibenzothiophenes and hydrogenation of tetralin over a SiO2 supported Ni-Mo-S catalyst

A one-step synthesized Ni-Mo-S catalyst supported on SiO2 was prepared and used for hydrodesulphurization （HDS） of dibenzothiophene （DBT）, and 4,6-dimethyl-dibenzothiophene （4,6-DMDBT）, and for hydrogenation of tetralin. The catalyst showed relatively high HDS activity with complete conversion of DBT and 4,6-DMDBT at temperature of 280℃ and a constant pressure of 435 psi. The HDS conversions of DBT and 4,6- DMDBT increased with increasing temperature and pressure, and decreasing liquid hourly space velocity （LHSV）. The HDS of DBT proceeded mostly through the direct desulphurization （DDS） pathway whereas that of 4,6-DMDBT occurred mainly through the hydrogenation- desulphurization （HYD） pathway. Although the catalyst showed up to 24% hydrogenation/dehydrogenation con- version oftetralin, it had low conversion and selectivity for ring opening and contraction due to the competitive adsorption of DBT and 4,6-DMDBT and insufficient acidic sites on the catalyst surface.

LCO高效加氢转化关键技术专用催化剂的开发与应用

面向解决催化裂化轻循环油(LCO)出路和富余柴油产能高值化利用的重大需求,以破解LCO加氢转化过程中芳环的加氢、环烷环的开环、烷基侧链的裂化和聚合结焦等关键反应对催化剂活性中心需求不一致的矛盾为切入点,通过创制新型催化材料、优化金属体系并改善制备方法等措施,开发了定向强化开环反应的柴油加氢改质催化剂RIC-3和兼具高开环与高断侧链性能的柴油加氢裂化专用催化剂RHC-100,构建了提高催化剂活性中心有效性、定向性和高效性的活性中心精细调控关键技术平台,形成了以RIC-3和RHC-100为核心、靶向调控多环芳烃加氢开环与裂化反应活性与选择性的催化剂族,可将劣质LCO转化为清洁柴油组分或高辛烷值汽油调合组分,为多环芳烃高效加氢转化技术的开发与应用提供技术支撑。

机械活化硫铁矿催化剂的表征及催化性能评价

煤直接液化工业催化剂面临原料成本高、水耗高和产生含盐废水等问题,有必要使用机械活化后的天然矿物作为煤直接液化催化剂,但需解决矿物催化剂粒径较大、过滤干燥后易板结及影响分散性和催化性能等问题。以某硫铁矿物为原料,以具有良好供氢性能的四氢萘为研磨介质,通过控制机械活化时间,得到一系列平均粒径小于5μm的矿物催化剂,催化剂无需过滤干燥,可直接加入煤直接液化反应体系中使用。利用扫描电镜、粒径分析、X射线衍射光谱和X射线光电能谱等手段对催化剂进行表征,矿物原料经机械活化后未发生明显聚集,活化2 h后催化剂平均粒径快速减小至2.82μm,延长活化时间后粒径减小速度放缓。机械活化过程对矿物中活性相FeS 2晶型无明显影响,但活化后催化剂表面Fe 2+和S 2-2量均明显增加,有利于催化活性的提高。催化剂在四氢萘中的沉降速度受粒径影响小,小粒径催化剂分散性基本相同。在相同的反应条件下,平均粒径为2.46μm的硫铁矿催化剂具有最佳的煤直接液化反应性能,转化率和油产率分别达到83.30%和43.53%。

Effects of some Nitrogen Bases on the Oxygenation of Tetralin with Sodium Periodate Catalyzed by Manganese（Ⅲ）meso- Tetraphenylporphyrin as a Model Compound of Cytochrome P-450

The effect of some nitrogen bases on the oxygenation of tetralin by sodium periodate, catalyzed by Mn（TPP）OAc, was evaluated. A series of eight bases, including imidazole, pyridine, and quinuclidine, was used. Binding of axial ligand to the four-coordinate Mn（Ⅲ）-center influenced the efficiency and selectivity of the catalytic oxygenation system.

Environmentally Friendly Room Temperature Synthesis of 1-Tetralone over Layered Double Hydroxide-Hosted Sulphonato-Salen-Nickel(II) Complex

1-Tetralone, a useful synthetic intermediate in the manufacture of pharmaceuticals, agrochemicals and dyes, can be prepared by liquid phase catalytic oxidation of tetralin. Selective oxidation of tetralin to 1-tetralone is still a big challenge with low-temperature processes using environmentally friendly routes even after decades of research. Herein, we demonstrate room-temperature oxidation of tetralin to 1-tetralone over layered double hydroxide-hosted sulphonato-salen-nickel(II) complex, LDH-[Ni-salen]. The layered double hydroxide-hosted sulphonato-salen-nickel(II) compound was characterized by powder X-ray diffraction, Fourier transform infrared spectrometer (FTIR), UV-Visible diffuse reflectance spectra, scanning electron microscopy (SEM) and elemental analysis. The theoretical calculations of free sulphonato-salen-nickel(II) complex using Density Functional Theory/CAM-B3LYP at the 6-311++ G(d,p) level of theory were also used to determine the orientation of the Ni-salen compound within the layered structure. The immobilized compound, LDH-[Ni-salen] was found to be an effective reusable catalyst for the oxidation of tetralin to 1-tetralone using a combination of trimethylacetaldehyde and molecular oxygen (14.5 psi) and at 25°C. At 45.5% conversion, tetralin was converted to 1-tetralone with 77.2% selectivity at room temperature and atmospheric pressure after 24 h. The catalyst recycles test and hot filtration experiment showed that oxidation proceeded through Ni(II) sites in LDH-[Ni-salen]. The catalysts were reused several times without losing their catalytic activity and selectivity. The present results may provide a convenient strategy for the preparation of 1-tetralone using layered double hydroxide-based heterogeneous catalyst at ambient temperature for industrial application in near future.

分子筛复配协同催化四氢萘裂解反应规律

采用压片法制备了USY分子筛、ZSM-5分子筛、Beta分子筛和复配分子筛,利用XRD、N2吸附-脱附、NH_(3)-TPD、Py-FTIR等方法对分子筛进行了表征,并利用固定床微型反应装置,考察了分子筛对四氢萘催化裂解反应规律的影响。实验结果表明,USY分子筛的反应转化率较高,但低碳烯烃和轻质芳烃的选择性较低;Beta分子筛反应转化率较高,且丙烯和轻质芳烃选择性较好;ZSM-5分子筛的低碳烯烃和轻质芳烃的选择性最好,但反应转化率最低。分子筛复配后,反应活性和氢转移能力均有改善,尤其是Beta分子筛与ZSM-5分子筛复配,可实现分子筛开环与择形性能的协同强化,相比Beta分子筛,低碳烯烃和轻质芳烃的选择性显著提高,其中丙烯选择性提高最多。

ZnW/β中ZnO含量对其催化四氢萘加氢裂化反应性能的影响

Zn的引入不仅可以调控β分子筛的酸性质,而且还会影响催化剂的加氢活性。为了研究Zn的引入对催化剂加氢裂化反应性能的影响,利用浸渍法合成了一系列不同ZnO含量的ZnW/β加氢裂化催化剂,并对其物理化学性能进行了分析表征。研究了ZnO含量对其催化四氢萘加氢裂化制备BTX(苯/甲苯/二甲苯)催化性能的影响。结果表明,最高BTX收率随着ZnO含量的增加先升高(质量分数<1%时)后降低(质量分数>1%时),这是由于随着ZnO含量的增加,ZnW/β催化剂的强酸量和总酸量明显减小,抑制了四氢萘的过度裂化。而当ZnO的负载量达到1%(质量分数)后,ZnO与WO_(3)反应会生成非活性组分ZnWO4晶体,非活性组分ZnWO4晶体的生成量随着ZnO的含量增大而增大,降低了催化剂中加氢活性组分WO_(3)的含量,导致ZnW/β催化剂的加氢中心与酸中心匹配不佳。ZnO负载量为1%的ZnW/β催化剂在反应空时为0.36 h时达到最高的BTX收率(41.57%,质量分数),说明该催化剂的酸量适中且加氢中心与酸中心匹配最佳。因此,催化剂金属中心与酸中心合适的匹配及适中的酸强度是提高BTX收率的关键。

四氢萘催化裂化研究进展

加氢处理油中含有一定量的环烷基单环芳烃,研究四氢萘催化裂化有利于加强对更多环数环烷基单环芳烃催化裂化的认识。综述了四氢萘催化裂化过程的反应机理,认为四氢萘主要遵循单分子裂化机理;从反应活化能、扩散、吸附等动力学角度对四氢萘裂解行为进行了解释;催化剂适宜的孔径和Bronsted酸强度有利于四氢萘开环;随着反应温度升高、剂/油质量比增大、质量空速减小,四氢萘反应活性增强,同时氢转移反应愈发明显。适宜的催化剂孔径和Bronsted酸强度、反应温度、剂/油质量比以及质量空速有利于四氢萘裂化生成低碳烯烃。

四氢萘加氢裂化反应规律研究

以四氢萘为模型化合物原料,采用加氢精制剂和裂化剂分级配比的模式,在高压微反固定床装置上进行加氢裂化反应。采用XRD、N_(2)吸附-脱附、TEM和NH_(3)-TPD方法对加氢精制剂和裂化剂进行了表征,并基于4因素6水平的正交实验,研究了采用不同酸量裂化剂时反应条件对加氢裂化产物收率的影响。实验结果表明,生产汽油的最佳反应条件是No.1裂化剂,反应温度360℃、反应压力8 MPa、氢油体积比600、质量空速3.5 h^(-1),最高汽油收率为11.13%;加氢反应的最佳反应条件是No.1裂化剂、反应温度405℃、反应压力7 MPa、氢油体积比400、质量空速2.0 h^(-1),最高加氢产物收率为32.21%;异构反应的最佳反应条件是No.1裂化剂、反应温度390℃、反应压力10 MPa、氢油体积比400、质量空速3.5 h^(-1),最高异构产物收率为35.03%;脱氢反应的最佳反应条件是No.2裂化剂、反应温度330℃、反应压力5 MPa、氢油体积比800、质量空速2.5 h^(-1),最低脱氢产物收率为0.62%。

四氢萘催化裂化反应行为及生焦研究

采用小型固定流化床(ACE)试验装置,在反应温度为460~540℃、质量空速为4~16 h^(-1)范围内研究了模型化合物四氢萘在稀土Y分子筛催化剂(REY-C)和超稳Y分子筛催化剂(USY-C)上催化裂化的反应行为及生焦规律。结果表明:四氢萘在REY-C、USY-C上的裂化产物类型相似,主要生成C_(3)~C_(5)烃以及C_(6)~C_(10)单环芳烃和茚满、甲基茚满、萘等双环芳烃;在REY-C、USY-C上,产物收率由大到小的顺序均为:双环芳烃>单环芳烃>非芳烃;分子筛的酸性强有利于催化裂化反应;焦炭的产率随着反应温度、四氢萘转化率、分子筛酸量的升高而增大,而随着空速的升高而降低。