柠檬酸对Ni-W焦化蜡油加氢处理催化剂性能的影响

以含改性HY分子筛的TiO₂-SiO₂复合氧化物为载体,以Ni、W为活性金属组分,采用等体积溶液浸渍法制得了焦化蜡油加氢处理催化剂,考察了浸渍液中加入柠檬酸对催化剂性质及加氢精制性能的影响。BET、FT-IR、XRD、UV-Vis DRS和TG-DSC等表征结果表明,柠檬酸与金属组分间的络合作用提高了金属活性组分的分散度,改变了金属组分的存在状态,促进了单一形式的聚钨酸盐和高活性的六配位八面体Ni物种的形成。柠檬酸改性的Ni-W系催化剂对焦化蜡油的加氢精制性能明显改善,尤其是加氢脱氮性能得以大幅度提高。     

加氢处理的新催化剂

丹麦海德罗-托普索（Haldor—Topsoe）公司开发了两种新的加氢催化剂，该催化剂基于其专有的BTIM技术。两种催化剂均为NiMo型，可应用于直接脱硫，对边缘活性中心（位于催化剂的基层）和Ⅱ型活性中心（边缘活性中心）的加氢进行了优化。     

制备过程中碳对加氢处理催化剂性能的影响

采用γ-Al_2O_3为载体,常规浸渍法制备加氢处理催化剂。在浸渍液中加入丙二醇,经过不同温度进行热处理,得到不同碳含量的催化剂。通过H_2-TPR、TEM、XPS等对催化剂表征,考察不同碳含量对加氢处理催化剂加氢性能的影响。结果表明,经过热处理后,有机助剂转化为碳,碳作为隔离分子存在于活性组分与载体之间,削弱活性组分与载体间相互作用力,使活性组分易于还原,活性组分分散度变大;同时MoS_2片晶层数增多、平均长度缩短,活性中心数目增加。催化剂性能评价结果表明,加氢处理催化剂上含有一定量的碳,有利于提高其加氢活性。     

原料对石脑油加氢催化剂性能的影响

对石脑油加氢处理产品硫、氮含量严重超标现象进行了研究 ,重点探讨了原料性质对催化剂活性的影响。研究表明 :直馏石脑油中高硫、氮含量蜡质混合物组分会引起NHT催化剂中毒 ,造成催化剂失活 ,此时通过提高反应温度和压力及降低空速对硫、氮的脱除效果影响不大 ,只有限制这种高硫、氮含量蜡质混合物进入装置 ,才能保证装置产品质量合格     

助剂B对含硅NiMo/Al2O3加氢处理催化剂性能的影响

考察了助剂B对含硅NiMo/Al₂O₃催化剂孔结构及表面酸性的影响，制备出一种孔容和比表面积大、孔分布集中、金属分布均匀和酸性适宜的加氢精制催化剂。分析结果表明，B的加入可以改善含硅氧化铝载体及催化剂的孔结构及表面酸性，有利于C—N键的断裂，从而提高催化剂的加氢脱氮性能。活性评价结果表明，采用适量B助剂改性的加氢处理催化剂具有高的加氢脱氮活性和稳定性。     

Ni-Mo/γ-Al_2O_3催化剂加氢处理工艺条件的优化

采用固定床加氢装置对原料油(蜡油)进行加氢精制研究,采用控制变量法,考察了反应温度,液时空速,氢油比等对加氢效果的影响。以Ni-Mo/γ-Al_2O_3作为催化剂对加氢工艺进行优化,由数据表明升高温度、适当降低液时空速、增大氢油体积比,均有助于提高催化剂的脱硫和脱氮效果。Ni-Mo/γ-Al_2O_3催化剂在中高压条件下,反应温度为400℃,液时空速为0.25 h~(-1),氢油体积比在2 000左右时,加氢精制的效果最好。     

催化剂性能对渣油加氢处理催化剂杂质沉积分布的影响

催化剂性能会改变催化剂运转过程中杂质的沉积分布规律。通过对催化剂物化性质的调整,可有效改善催化剂上杂质的分布,提高床层金属容纳能力、减少积炭,延长装置运转周期。通过对工业运转后的渣油加氢催化剂进行分析发现,中国石油化工股份有限公司石油化工科学研究院开发的新一代高效渣油加氢处理RHT系列催化剂在物化性质方面的改善使其性能明显优于第一代RHT催化剂,具有高脱金属活性、高容金属能力和减少催化剂表面积炭的能力,有利于发挥催化剂整体优势和延长运转周期。     

铁基催化剂对铁厂沟煤加氢热解特性的影响

利用固定床反应器,考察了浸渍法添加硝酸铁、氯化铁和硫酸亚铁铵等铁基催化剂对煤加氢热解特性的影响,对提高焦油产率较显著的硫酸亚铁铵的作用过程进行了探讨,并对其焦油进行了分析评价.结果表明,添加这三种催化剂时煤加氢热解的转化率都有提高,其中在添加5%(质量分数,以铁计)的硫酸亚铁铵时焦油的产率提高最为显著,由不加催化剂时的14.3%(质量分数,daf)提高到17.9%;铁的价态不同对煤加氢热解的催化作用不同,铵根的存在有利于煤热解转化率和焦油产率的提高;采用硫酸亚铁铵为催化剂时煤热解得到的焦油品质优于无催化剂时得到的焦油品质.     

预硫化型加氢精制催化剂SK-1对FCC柴油加氢改质性能小试研究

在100mL小型加氢装置上,对预硫化型加氢催化剂SK-1的FCC柴油加氢改质性能和开工处理条件进行了考察,研究结果表明,在340℃、4.0 MPa和2.0 h-1缓和加氢条件下,SK-1可使FCC柴油十六烷值提高约9.5个单位,柴油脱硫率约达93%,脱氮率可达78%,柴油的苯胺点约提高6℃,SK-1的脱硫活性基本与FC-1和CK-2相当,SK-1的脱氮率高于对比催化剂FC-1和CK-2,SK-1的柴油实际收率高于FC-1和CK-2.预硫化型加氢催化剂SK-1的开工处理过程简便、不需预硫化,易操作,无污染,开工时间大大缩短,催化剂床层不存在温度骤然升高(飞温)的现象.     

加氢处理催化剂制备技术研究进展

从过渡金属硫化物催化剂活性相理论出发,认为在加氢催化剂制备过程中保证活性组分的适度分散和金属-载体之间适度的相互作用能提高加氢催化剂的性能。本文针对加氢处理催化剂的制备技术,综述了添加有机助剂、平衡吸附法、浆液浸渍法等浸渍改进技术以及水热沉积法、原位晶化法、化学气相沉积法等新型的制备技术,并介绍了相关的国内外研究进展。分析指出有机助剂能与载体、金属作用,进而改变金属在载体表面的存在形态,有利于高活性CoMoS相的生成;水热沉积法和原位晶化法能够使活性组分在载体上均匀吸附沉积,从而实现活性组分在载体上的分散,并形成堆积程度更高的高活性Ⅱ型活性中心。     

Effect of preparation variables on the activity of Ni-W/Al2O3 hydrotreating catalysts

Studies have been carried out on the influence of preparation parameters on the activity of nickel-tungsten (Ni-W) catalysts, used to promote the hydrotreatment of model compounds representative of nitrogen, sulphur, oxygen and aromatic containing compounds which typically occur in coal derived liquids. The preparation variables considered for optimisation were the pH of the impregnating solution, the impregnation order, the starting Ni salts, the Ni/Ni + W ratio, the drying conditions and the calcination temperature. It was found that changes in pH, within the range where binding of the starting ions to alumina takes place, is not a significant variable influencing the activity. The use of nickel nitrate as a precursor yields better catalysts. If W is impregnated first it is redistributed during subsequent nickel impregnation, and better catalysts are obtained when Ni is impregnated first. The optimum Ni/Ni + W ratio is between 0.3 and 0.4, based on the total active metals present on the catalyst. The hydrodesulphurisation hydrodeoxygenation and hydrogenation activities decrease with increase in the drying temperature; the reverse is true for hydrodenitrogenation. An optimum activity is obtained when drying at 100°C in a closed oven. The optimum calcination temperature was found to be 500°C.     

Effect of vacuum gas oil hydrotreating reactor on multiple reactors and hydrogen network

The inlet temperature of the Vacuum Gas Oil (VGO) hydrotreating reactor of a refinery is analyzed with the integration of multiple series reactors and hydrogen network considered. The effect of the inlet temperature (T₁) on hydrogen sinks/sources and the product output is analyzed systematically based on the simulation of the series reactors, including VGO hydrotreating reactor, hydrocracking reactor, fluid catalytic cracking reactor and visbreaking reactor. The general relation between the Hydrogen Utility Adjustment (HUA) and multiple pairs of varying sinks and sources is deduced, and correlations between varying streams and T₁ are linearly fitted. Based on this, the quantitative equation between HUA and T₁ is derived, and corresponding diagram is constructed. The T₁ corresponding the minimum hydrogen consumption is identified to be 345℃.     

Effect of EDTA on hydrotreating activity of CoMo/γ-Al2O3 catalyst

γ-Al₂O₃ supported Co (0–4.5 wt%) Mo (9.0 wt%) sulfide catalysts were prepared in the presence and the absence of ethylenediaminetetraacetic acid (EDTA). The hydrodenitrogenation (HDN) activity of these catalysts was studied in the model reaction of 2,6-dimethylaniline (DMA) at 300 °C under 4 MPa. The CoMo/Al₂O₃ catalysts prepared with the EDTA showed higher HDN of DMA than those prepared without EDTA. The maximum of 36% increase in rate constant of HDN of DMA was observed over the catalyst with 3% Co prepared using EDTA. The FT-IR spectroscopy of adsorbed CO on CoMo catalysts showed that EDTA addition promoted the formation of catalytically active “CoMoS” phase as evidenced from increases in intensity of band at 2070 cm⁻¹, which is maximum for 3% Co loaded catalysts. The HDN and hydrodesulfurization (HDS) activity of 3% Co loaded catalyst prepared using EDTA was tested and compared with those catalyst prepared without EDTA in a trickle bed reactor using heavy gas oil derived from Athabasca bitumen in the temperature range 370–400 °C and 8.8 MPa. Improved HDN and HDS conversion of heavy gas oil was obtained for the catalyst prepared with EDTA.     

EDTA对硅垢形成过程的影响机理

为揭示EDTA对硅酸聚合沉淀过程的影响机理,本文结合浊度分析法和粒度分析法研究了有无添加EDTA的不同浓度硅酸钠溶液的浊度变化及粒径变化.浊度分析结果发现,硅酸钠浓度为400 mg·L-1和800 mg·L-1时,溶液的浊度基本相同,在3 NTU左右.而硅酸钠浓度大于800 mg·L-1时,溶液浊度随浓度的增大而增大.在同样的硅酸钠溶液中添加一定浓度的EDTA时,混合溶液的浊度大于相应的硅酸钠溶液的浊度,且添加的EDTA浓度越大浊度越大,说明EDTA促进硅酸的聚合反应.粒度分析结果发现,添加EDTA的混合溶液中所形成的硅胶颗粒的粒径比相应的硅酸钠溶液的粒径大,且随EDTA浓度的增加而增大,说明EDTA促进硅胶颗粒的生长.根据FT-IR分析结果推测EDTA对硅酸聚合沉淀的促进机理如下:EDTA分子内所含的羰基上的氧原子或胺基上的氮原子通过氢键与溶液中已形成的硅胶体表面的Si-OH官能团相互作用,通过P-P反应把小的硅胶颗粒集聚到一起,促进硅胶颗粒的生长,从而促进硅酸的聚合沉淀反应.     

Effect of EDTA concentration on the physical and optical properties of Cds thin films

Application of ethylenediamine tetraacetic acid (EDTA) in the chemical bath solution to enhance the physical and optical properties of chemical bath deposited CdS film was realised. The observed beneficial effect on the crystallisation of CdS crystallites in the bath solution followed by deposition on glass substrates reduces the amorphousity and enhances the crystallinity of the film. The optical transparency of the film attains a maximum of 80% over the wavelength range of 650–1100 nm for the film deposited from EDTA‐added solution having the concentration of 0.006 mol/L. Also, the observed intensity of the characteristic photoluminescence emission was found to be dependent on the concentration of EDTA in the bath solution. © 2011 Canadian Society for Chemical Engineering     

EDTA配合滴定法测定食盐中的钙含量

钙是人体所不可或缺的营养素之一,但受地域和环境条件的影响,我国人口中缺钙的情况依然存在。目前市场上供应的加钙盐和其他一些营养盐可以满足人们补充体内钙元素的需要,因此研究营养盐中钙的含量具有非常重要的意义。为建立快速简便的钙含量测定方法,采用EDTA配合滴定法测定加钙盐中钙的含量,测定结果加钙食盐中钙含量均符合国家标准。实验操作简单,结果准确,易于推广。     

PHF-101型催化剂在2.0Mt·a~(-1)柴油加氢装置的工业应用

介绍了PHF-101型柴油加氢精制催化剂在中国石油乌鲁木齐石化分公司2.0 Mt·a~(-1)柴油加氢装置的工业应用情况,结果表明,在反应器入口压力7.83 MPa、空速1.84 h~(-1)、平均温度358℃和氢油体积比476∶1条件下,加工硫含量1 835μg·g~(-1)的混合汽油和柴油原料,精制柴油硫含量4.8μg·g~(-1),十六烷值提高4.0个单位。PHF-101型催化剂加氢性能优良,运转稳定性良好,满足国Ⅳ和国Ⅴ柴油生产需求。     

微膨胀床渣油加氢处理反应器的研究

为考察微膨胀床渣油加氢处理反应器的气液流动状态、床层膨胀率及反应性能,常温、常压下用模拟油气在冷模实验装置上进行了近似模拟,并采用微膨胀床/固定床中型实验装置处理了中东高硫渣油。结果表明:按返混程度微膨胀床反应器可分为3个区域;大粒径、低堆密度催化剂易膨胀;空塔气速对床层膨胀率影响大于空塔液速;中型实验装置可脱除渣油中80%以上硫和钒以及50%以上镍和残炭,其中微膨胀床脱除率占50%以上。