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1.
Hydrodesulfurization(HDS) of sour crude oil is an effective way to address the corrosion problems in refineries and is an economic way to process sour crude oil in an existing refinery built for sweet oil.Siberian crude oil transported through the Russia-China pipeline could be greatly sweetened and could be refined directly in local refinery designed for Daqing crude oil after the effective HDS treatment.In this study,the HDS of Siberian crude oil was carried out in a continuous flow isothermal trickle-bed reactor over Ni-Mo/γ-Al_2 O_3.The effects of temperature,pressure and LHSV were investigated in the ranges of 320-360℃,3-5 MPa and 0.5-2 h~(-1),keeping constant hydrogen to oil ratio at 600 L·L~(-1).The HDS conversion could be up to 92.89% at the temperature of 360℃, pressure of 5 MPa,and LHSV of 0.5 h~(-1), which is sufficient for local refineries(84%).A three phase heterogeneous model was established to analyze the performance of the trickle-bed reactor based on the two-film theory using Langmuir-Hinshelwood mechanism.The order of sulfur component is estimated as 1.28,and the order of hydrogen is 0.39.By simulating the reactor using the established model,the concentration of H_2, H_2 S and sulfur along the catalyst bed is discussed.The model is significantly useful for industrial application with respect to reactor analysis,optimization and reactor design,and can provide further insight of the HDS of Siberian crude oil. 相似文献
2.
A commercial Co---Mo/Al 2O 3 catalyst was labeled with the radioisotope 35S in hydrodesulfurization (HDS) of 35S-labeled dibenzothiophene ( 35S-DBT) in a high-pressure flow reactor at 50 kg/cm 2. Then, HDS of 4-methyldibenzothiophene (4-MDBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) or sulfur exchange of H 2S were carried out on the labeled catalyst at 50 kg/cm 2 and 260–360°C. The amounts of labile sulfur participating in the reaction were determined from the radioactivity of 35S---H 2S released from the 35S-labeled catalyst. In the HDS reactions, the amount of labile sulfur participating in the reaction decreased in the order: DBT> 4-MDBT> 4,6-DMDBT. In the sulfur exchange reaction with H 2S, the adsorption of H 2S on the catalyst reached saturation above a H 2S partial pressure of 0.36 kg/cm 2. It was suggested that the release of H 2S from the labile sulfur may be the rate determining step of the HDS reaction. 相似文献
3.
Hydrodesulfurization (HDS) of sour crude oil is an effective way to address the corrosion problems in refineries, and is an economic way to process sour crude oil in an existing refinery built for sweet oil. In the current study, the HDS of Siberian crude oil was carried out in a slurry reactor. The Co–Mo, Ni–Mo, and Ni–W catalysts supported on γ-Al 2O 3 were compared at the temperature of 340 °C and the pressure of 4.5 MPa. The HDS activity follows the order of Co–Mo > Ni–Mo > Ni–W at a high concentration of H 2S, and the difference between Co–Mo and Ni–Mo becomes insignificant at a low concentration of H 2S. The influence of reaction temperature 320–360 °C and reaction pressure 3–5.5 MPa was investigated, and both play a positive role in the HDS reaction. A kinetic model over Ni–Mo/Al 2O 3 in the slurry reactor was established. The activation energy is estimated as 60.34 kJ·mol −1; the orders of sulfur components and hydrogen partial pressure are 1.43 and 1.30, respectively. The kinetic parameters are compared with those in a trickle-bed reactor, implying that the mass transfer is greatly enhanced in the slurry reactor. The back mixing effect is present in the slurry reactor and can be reduced by a multi-stage design, which would lead to higher reactor efficiency in industrial application. 相似文献
4.
Sulfidation of trimetallic CoNiMo/Al 2O 3 catalysts was studied by thermogravimetry at 400 °C under flow and pressure conditions. Results were compared with those obtained on prepared and industrial CoMo/Al 2O 3 and NiMo/Al 2O 3 catalysts. The amount of sorbed H 2S on the sulfided solids was measured at 300 °C in the H 2S pressure range 0–3.5 MPa at constant H 2 pressure (3.8 MPa). The adsorption isotherms were simulated using a model featuring dissociated adsorption of H 2S on supported metal sulfides and bare alumina. The amount of sulfur-vacancy sites could thus be determined under conditions close to industrial practice. A relationship with activity results for thiophene HDS and benzene hydrogenation was sought for. 相似文献
5.
The relative-volume activities (RVAs) for real feedstocks HDS of four commercial CoMo/Al 2O 3 catalysts have been compared to the rates for thiophene and dibenzothiophene conversion. The reaction of thiophene competing with H 2S was studied in flow microreactors under a wide range of conditions: 300–400°C, overall pressure 0.1 or 3 MPa, thiophene pressure 8–125 kPa, H 2S content 0–15 mol%. The reaction of dibenzothiophene (DBT, 2 wt% in decaline) was carried out in a batch reactor at 335°C and 4 MPa. The conversion of the two model molecules proceeds through the same mechanism with a preliminary dearomatization step followed by parallel hydrogenolysis and hydrogenation. From kinetic modeling, the global rates and the contribution of the hydrogenation and hydrogenolysis routes to HDS were determined. Under pressure, hydrogenolysis was predominant. In that case, thiophene and DBT behaved similarly and their initial relative rates did not correlate the RVA. Industrial HDS is controlled by hydrogenation as evidenced by the good correlation between RVA and the rates of dearomatization of thiophene at atmospheric pressure and hydrogenation of the product biphenyl from DBT under pressure. It is concluded that the reaction of model molecules under selected conditions can appraise rapidly industrial HDS. 相似文献
6.
The feasibility of using a cobalt-molybdenum (Co-Mo) sulfide catalyst that was prepared from a commercial Co-Mo oxide catalyst for the production of elemental sulfur from hydrogen sulfide (H 2S) and carbon dioxide (CO 2) in a packed bed catalytic reactor was studied. It was demonstrated that the desired sulfide catalyst could be prepared by first reducing, then sulphiding the corresponding oxide. The results showed that the prepared catalyst was capable of producing elemental sulfur from the thermal decomposition of H 2S in the presence of CO 2 over a temperature range of 465-700°C and at atmospheric pressure. A specific rate coefficient was calculated as well as the Arrhenius parameters for the non-equilibrated reaction. The H 2S decomposition reaction was found to be a second order reaction and have an activation energy of 114.4kJ/mol(27.3kcal/mol). 相似文献
7.
Catalytic desulphurization of benzothiophene (BTH) in a water/toluene emulsion, a model system for heavy oil emulsions, was achieved at 340°C using a water-soluble phosphomolybdic acid (PMA), a precursor for dispersed Mo catalyst. This process is based on the activation of H 2O to generate H 2 in situ via the water gas shift reaction (WGSR) for hydrodesulphurization (HDS). At 340°C with an initial CO loading of 4.14 MPa, essentially complete sulphur removal was obtained. Kinetic expressions for the WGSR and HDS of BTH with in situ generated H 2 and externally supplied H 2 were developed and verified experimentally. The kinetic analysis indicates that WGSR is rate-determining and desulphurization with in situ generated H 2 is a relatively fast step. Apparently, in situ H 2 is about seven times more active than externally supplied H 2 for the hydrogenation of BTH. A mechanism for desulphurization involving initial hydrogenation of BTH to dihydrobenzothiophene (DHBTH) followed by hydrogenolysis to give ethylbenzene (EB) and H 2S is proposed. 相似文献
8.
The effect of the TiO 2–Al 2O 3 mixed oxide support composition on the hydrodesulfurization (HDS) of gasoil and the simultaneous HDS and hydrodenitrogenation (HDN) of gasoil+pyridine was studied over two series of CoMo and NiMo catalysts. The intrinsic activities for gasoil HDS and pyridine HDN were significantly increased by increasing the amount of TiO 2 into the support, and particularly over rich- and pure-TiO 2-based catalysts. It is suggested that the increase in activity be due to an improvement in reducing and sulfiding of molybdena over TiO 2. The inhibiting effect of pyridine on gasoil HDS was found to be similar for all the catalysts, i.e., was independent of the support composition. The ranking of the catalysts for the gasoil HDS test differed from that obtained for the thiophene test at different hydrogen pressures. In the case of gasoil HDS, the activity increases with TiO 2 content and large differences are observed between the catalysts supported on pure Al 2O 3 and pure TiO 2. In contrast, in the case of the thiophene test, the pure Al 2O 3-based catalyst appeared relatively more active than the catalysts supported on mixed oxides. Also, in the thiophene test the difference in intrinsic activity between the pure Al 2O 3-based catalyst appeared relatively more active than the catalysts supported on mixed oxides. Also in the thiophene test, the difference in intrinsic activity between the pure Al 2O 3- and pure TiO 2-based catalysts is relatively small and dependent on the H 2 pressure used. Such differences in activity trend among the gasoil and the thiophene tests are due to a different sensitivity of the catalysts (by different support or promoter) to the experimental conditions used. The results of the effect of the H 2 partial pressure on the thiophene HDS, and on the effect of H 2S concentration on gasoil HDS demonstrate the importance of these parameters, in addition to the nature of the reactant, to perform an adequate catalyst ranking. 相似文献
9.
以Beta分子筛为载体,采用等体积浸渍法制备不同双组分金属类型(Ni-Mo、Ni-W和Co-Mo)加氢裂化催化剂,利用XRD、BET、NH3-TPD、Py-IR和H2-TPR等对催化剂进行表征。在固定床连续加氢反应器上考察催化剂对四氢萘加氢裂化性能的影响,结果表明,催化剂CAT-a(Ni-Mo/Beta)有较适宜的比表面积和孔体积,酸量和酸强度最大,四氢萘转化率和BTX选择性最高。以Ni-Mo/Beta催化剂为研究对象,考察不同金属负载量对催化剂物化性质及四氢萘反应性能的影响,结果表明,Beta分子筛载体上金属负载质量分数18%的催化剂最适宜四氢萘加氢裂化多产BTX类物质。 相似文献
11.
以NNY分子筛和Hβ分子筛为酸性组分,以γ-Al 2O 3为载体原料、Ni-W为金属组分、P为改性剂,采用较合适的配比利用挤条成型法和等体积饱和浸渍法制备较优的中油型加氢裂化催化剂,并针对此催化剂,在恒压15 MPa条件下,反应温度、空速和氢油体积比的变化对加氢裂化过程中馏分油转化率、产品分布、中油选择性和HDS、HDN效果的影响进行探究。结果表明,随着反应温度升高,转化率增大,产品分布向轻组分偏移,脱硫率和脱氮率增加,但中油选择性降低;随着空速增大,转化率、脱硫率和脱氮率均降低,中油选择性增大;随着氢油体积比增大,转化率、脱硫率和脱氮率先增大后趋于稳定,产品分布和中油选择性基本不变。在反应压力15 MPa、反应温度380 ℃、空速0.7 h -1和氢油体积比1 500∶1条件下,转化率84.6%,中油选择性91.3%,生成油硫含量9.28 μg·g -1,氮含量1.46 μg·g -1。 相似文献
12.
Sulfur uptake by reduced Mo0 3 and CoMoO 4 catalysts when passing H 235S pulses was measured. Also, the release of labelled sulfur was monitored when thiophene and cyclohexanol pulses were reacted over these catalysts. The sulfur release was about 20% of the retained amount in the H 2S/thiophene system. Here the conversion of thiophene in HDS was inversely proportional with the amount of irreversibly retained sulfur. A few pulses of cyclohexanol could stop sulfur uptake indicating that oxygen can be more firmly held by the catalyst than sulfur. All these arc in favor of interpreting the active sites as anion vacancies. @KEYWORDS: Catalysts, Sulfur, Radiotracer, Mo and Co-Mo Catalysts. 相似文献
13.
以中低温煤焦油360℃的馏分油为原料,Ni-Mo/γ-Al2O3为催化剂,在小型固定床单管加氢反应器上进行加氢实验。在压力13 MPa、空速0.4 h-1、氢油体积比1 700∶1和反应温度370℃工艺条件下进行催化加氢反应,通过对原料油和加氢产物的GC-MS的检测结果分析,确定了酚类、萘类、联苯类和菲类化合物的加氢转化路径,得到煤焦油馏分油中主要化合物的加氢反应网络。 相似文献
14.
采用工业Ni-Mo/Al 2O 3-HZSM-5催化剂在小型固定床加氢微反装置上对催化裂化(FCC)汽油临氢改质过程的反应特性进行了研究,通过考察反应温度、压力、空速和氢油体积比对改质后的FCC汽油烃类组成的影响,分析了汽油中不同烃类的转化性能。结果表明,氢油比对产物组成影响不大,高温、低压、低空速有利于增加芳烃的选择性,低温、高压、高空速则有利于增加异构烷烃的选择性;临氢改质后,FCC汽油的烯烃含量明显降低,芳烃和异构烷烃含量增加,因而产品汽油的辛烷值基本保持不变;全馏分、轻馏分和重馏分FCC汽油临氢改质实验结果表明,烯烃含量较高的轻馏分具有更高的转化活性;在FCC汽油临氢改质过程中,同碳数的端烯烃反应活性高于内烯烃,直链烯烃的反应活性高于支链烯烃。 相似文献
15.
In this work, we explored the potential of mesoporous zeolite-supported Co–Mo catalyst for hydrodesulfurization of petroleum resids, atmospheric and vacuum resids at 350–450°C under 6.9 MPa of H 2 pressure. A mesoporous molecular sieve of MCM-41 type was synthesized; which has SiO 2/Al 2O 3 ratio of about 41. MCM-41 supported Co–Mo catalyst was prepared by co-impregnation of Co(NO 3) 2·6H 2O and (NH 4) 6Mo 7O 24 followed by calcination and sulfidation. Commercial Al 2O 3 supported Co–Mo (criterion 344TL) and dispersed ammonium tetrathiomolybdate (ATTM) were also tested for comparison purposes. The results indicated that Co–Mo/MCM-41(H) is active for HDS, but is not as good as commercial Co–Mo/Al 2O 3 for desulfurization of petroleum resids. It appears that the pore size of the synthesized MCM-41 (28 Å) is not large enough to convert large-sized molecules such as asphaltene present in the petroleum resids. Removing asphaltene from the resid prior to HDS has been found to improve the catalytic activity of Co–Mo/MCM-41(H). The use of ATTM is not as effective as that of Co–Mo catalysts, but is better for conversions of >540°C fraction as compared to noncatalytic runs at 400–450°C. 相似文献
16.
Factors controlling the product ratio of CO 2/(CO+CO 2) and methods for inhibiting deactivation of catalyst for steam reforming of gasoline were studied. Syngas (H 2+CO) as major product was produced on Ni-Mo/Al 2O 3 and the major product on Ni-Re/Al 2O 3 was H 2 and CO 2 at the same reaction conditions. Hydrogen with a high CO 2/(CO+CO 2) ratio of about 92% was produced by coupling reaction of steam reforming and water gas shift on Ni-Re/Al 2O 3 catalyst at 805 K. The multifunctional activity of the bimetallic catalyst of Ni-Re/Al 2O 3 and the suitable reaction temperature were of crucial significance for the coupling reaction. Although no deactivation could be observed on both Ni-Mo/Al 2O 3 and Ni-Re/Al 2O 3 catalysts for steam reforming of sulfur-free fuels in about 200 h of time on stream, the activity and sulfur-tolerance of Ni-Re/Al 2O 3 was much better than the values of Ni-Mo/Al 2O 3 for steam reforming of sulfur-containing fuels because of the unique role of rhenium in the Ni-Re catalyst. The unique role of rhenium in Ni-Re catalyst was mainly because of alloying of rhenium with nickel to form bimetallic Ni-Re sites and interaction of rhenium with sulfur to form S-Re binds. The sulfur-tolerance of Ni-Re/Al 2O 3 for steam reforming of sulfur-containing gasoline was improved further by addition of a small amount of ZSM-5. The activity and sulfur-tolerance of Ni-Mo/Al 2O 3 was also enhanced by the addition of ZSM-5. 相似文献
17.
The room temperature wet catalytic oxidation was conducted in a batch reactor with Fe/MgO catalyst. Fe/MgO catalyst was prepared by the dissolution–precipitation method. XRD and temperature-programmed reductions (TPR) indicate that Fe oxide in the Fe/MgO is finely dispersed in the MgO support. The high H 2S removal capacities of Fe/MgO can be explained by the finely dispersed iron oxide MgO. The H 2S removal capacities of Fe/MgO are dependent on oxygen partial pressure (1.0 g H 2S/g cat in air and 2.6 g H 2S/g cat in oxygen). The valence state analysis of Fe/MgO catalyst suggests that the H 2S oxidation on Fe/MgO can occur by a redox couple reaction, reducing Fe 3+ into Fe 2+ by H 2S and oxidizing Fe 2+ to Fe 3+ by O 2. 相似文献
18.
A novel process was developed for the bitumen emulsion upgrading, wherein emulsion breaking and upgrading occurred in the same reactor using H 2 generated in situ from the water in the emulsion via the water gas shift reaction (WGSR). In this study, dibenzothiophene (DBT) was chosen as a model compound to investigate the effect of water and in situ H 2 on hydrodesulfurization (HDS). All the experiments were performed in a 1-L autoclave reactor at temperatures between 300 and 380 °C using in situ H 2 and ex situ H 2 (externally supplied H 2) over a dispersed Mo catalyst formed from phosphomolybdic acid (PMA). At very low water content, water was found to promote the HDS reaction in the ex situ H 2 run probably because it facilitates the formation of more active dispersed MoS x species. At higher water content, however, water inhibits every individual reaction in the reaction network in the HDS of DBT, blocking the hydrogenation pathway more than the hydrogenolysis pathway. The relative reactivity of the in situ and ex situ H 2 depends on the water content present in the reaction system. At an optimized mole ratio of H 2O:CO (1.35), higher HDS activity was observed in the in situ H 2 run compared to ex situ H 2 run, and particularly, the hydrogenation pathway was promoted in the in situ H 2 run. 相似文献
19.
采用等体积浸渍法制备了以TiO_2-Al_2O_3为载体,Ni、W为活性金属组分的加氢脱硫催化剂,考察了稀土金属镧(La)、乙二胺四乙酸(EDTA)改性以及La-EDTA组合改性对催化剂结构和加氢脱硫性能的影响。通过X射线衍射、N2吸附-脱附、H2-程序升温还原和扫描电子显微镜对催化剂进行表征分析。结果表明,La和EDTA均可改善活性组分与载体间的相互作用,增加了Ni-W-S活性相的数量,有利于金属组分的还原;同时能够丰富催化剂孔道,抑制催化剂表面金属离子聚集,得到更好的孔结构、更高的活性相分散度。La或EDTA以及两者同时改性后的催化剂噻吩硫脱除率均明显高于未改性催化剂,其中Ni-W-La-E催化剂上噻吩转化率为99.7%。 相似文献
20.
To define the roles of H 2S and pyrrhotite in high temperatures employed for normal coal liquefaction, diphenylmethane hydrocracking with H 2 and H 2-H 2S was carried out with and without pyrrhotite. H 2S promotes diphenylmethane hydrocracking with H 2 both in the presence and absence of pyrrhotite, and the reaction is dependent upon the H 2S pressure in both instances. It is also dependent on the H 2 pressure when pyrrhotite is present. The results are interpreted in terms of H 2S acting as a hydrogen transfer catalyst. 相似文献
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