Diesel Intensive Desulfurization

The research to diesel super intensivedesulfurization through oxidative ex-traction undertaken by AcademicianLi Can from CAS Dalian Research In-stitute of Chemistry and Physics hasmade a major breakthrough and ap-plied for two invention patents inChina. A high-effect hydrophilic/     

Diesel Yield with Biological Enzyme Process Reaches Over 90%

According to the information released byTsinghua University on March 29,an en-tirely new biological enzyme process thathas simple operation and can effectivelytransform animal and plant grease intobiological diesel has made successful     

Alumina Supported Co–K–Mo Based Catalytic Material for Diesel Soot Oxidation

Alumina supported Co–K–Mo based mixed metal oxide type catalytic materials have been prepared by co-impregnation. These catalysts show excellent activity for carbon as well as diesel soot oxidation, which could be due to the redox properties of Mo and Co as well as to a synergistic effect of molybdenum, cobalt, and K contents. The catalyst containing 5 wt% molybdenum shows a lowering of carbon oxidation by about 190 °C under loose contact conditions as compared to the non-catalyzed reaction, as well as to bare alumina. Characterization studies suggest a composite nature of these materials, while thermal stability investigations confirm the stable nature. The selected catalyst has been studied by XPS, however, it is difficult to conclude which are the important factors contributing to the catalytic activity. It appears to be a synergistic effect of Co, K, and Mo components as these catalysts show much improved activity as compared to the individual components in supported and unsupported forms.     

Selective Hydrocracking of Fischer–Tropsch Waxes to High-quality Diesel Fuel Over Pt-promoted Polyoxocation-pillared Montmorillonites

Polyoxocation ([AlO₄Al₁₂(OH)₂₄(H₂O)₁₂]⁷⁺ and [Zr₄(OH)₁₄(H₂O)₁₀]²⁺)-pillared montmorillonites were prepared by ion exchange, and they were used as solid acid catalysts, in comparison to some other solid acids, for the selective hydrocracking of Fischer–Tropsch waxes to diesel-ranged hydrocarbons. XRD patterns and elemental analyses proved that the polyoxocations were successfully introduced into the interlayer region of the montmorillonites. N₂ adsorption–desorption measurement indicated that polyoxocation-pillared montmorillonites have large BET surface areas (>230 m² g^?1), high thermal stability (>673 K), and large pores (comparing to those in zeolites). FT-IR spectra of chemisorbed pyridine indicated that polyoxocation-pillared montmorillonites possess both Lewis and Bronsted acid sites on the solid surface. Temperature-programmed desorption of ammonia indicated that the acidity strength of the polyoxocation-pillared montmorillonites was weaker than those of H–ZSM-5, H–Y, WO₃/ZrO₂, and Al₂O₃–SiO₂. In the hydrocracking of Fischer–Tropsch (F–T) waxes, the acidity strength of the solid acids in bifunctional catalysts greatly influences the product composition. Pt-promoted H–Y afforded a high yield of gasoline-ranged hydrocarbons (>90%) while Pt-promoted H–ZSM-5 afforded a larger amount of gas products due to its strong solid acid sites. On the other hand, among various catalysts, Pt-modified polyoxocation-pillared montmorillonites afforded the highest yield of diesel-ranged hydrocarbons (>70%) due to the appropriately weak acid strength, high thermal stability, large BET surface area, and large pore size. Pt is necessary for the hydrocracking of F–T waxes because it enables hydrogenation/dehydrogenation. However, a high Pt loading on the catalyst produces more light hydrocarbons due to the stimulation of hydrogenolysis. High hydrogen pressure improved the selectivity for diesel-ranged hydrocarbons but decreased the conversion of F–T waxes due to the suppression of alkane dehydrogenation. The hydrocracking of F–T waxes at a low temperature with a large amount of catalyst for longer reaction time increased the yield of diesel-ranged hydrocarbons.     

Influence of Methanol–Biodiesel Blends on the Particulate Emissions of a Direct Injection Diesel Engine

In this study, Euro V diesel fuel, biodiesel, and methanol–biodiesel blends were tested in a 4-cylinder direct-injection diesel engine to investigate the combustion characteristics and particulate emissions of the diesel engine under five engine loads at the maximum torque engine speed of 1800 rpm. Compared with Euro V diesel fuel, biodiesel gives lower and earlier heat release rate. For the blended fuels, the peak heat release rate becomes higher and retarded. With regard to particulate mass concentration, biodiesel generates less than Euro V diesel fuel, while the blended fuels result in significant reduction especially at high engine loads. Compare with Euro V diesel fuel, the total particle number concentration of using biodiesel is always higher while the geometric mean diameter (GMD) of the particles is lower. With the blended fuel, the total number concentration and GMD decrease in comparison with pure biodiesel. Further analysis shows that the difference between the total number concentration of biodiesel and Euro V diesel fuel is in particles smaller than 50 nm rather than in the larger particles. The use of methanol–biodiesel blends, compared with biodiesel, could reduce the number concentration of all sizes. A comparison between the particulate mass emission and total particulate number concentration with the mass of fuel burned in the diffusion mode show that they are strongly related to each other, even for the blended fuel.     

The Effect of Sulphur and Water Treatments on the Performance of Pd/��-Zeolite Diesel Oxidation Catalysts

Sulphur, sulphur-water, and water pretreatments were done to find out the effect of these compounds on a diesel oxidation Pd/??-zeolite catalyst and ??-zeolite washcoat. After pretreatments, the samples were analysed by BET, XRF, TEM-SEM, and XPS. In addition, the activity of fresh and pretreated Pd/??-zeolite catalysts was studied utilizing the by Gasmet FT-IR in production gas analysis. Sulphur compounds (SO₂ or ?SO₄) were found to have a deactivating effect on the activity of the studied Pd/??-zeolite catalyst.     

LaCo1−x Pd x O3 Perovskite-Type Oxides: Synthesis, Characterization and Simultaneous Removal of NO x and Diesel Soot

A series of naometric perovskite catalysts LaCo_1?x Pd _x O₃ (x = 0, 0.01, 0.03) were prepared via a solution combustion synthesis route using metal nitrates as oxidizers and urea as fuel. It is essential to add a certain amount of ammonia aqueous solution to Pd²⁺ ions solution in the catalyst preparation process. Homogeneous nanoparticles LaCo_1?x Pd _x O₃ catalysts with the sizes in the range of 68–122 nm were obtained and characterized by using of XRD, BET, H₂-TPR, XPS, SEM and TEM. Pd was successfully introduced into the LaCoO₃ perovskite lattices. Further information was obtained by using XPS upon the LaCo_0.97Pd_0.03O₃ (with NH₄OH) sample after H₂-TPR. The results revealed that surface Pd was reduced to the metallic state at the end of the first step in the H₂-TPR experiment, and some surface Co could be reduced to metallic Co simultaneously. The catalytic properties were investigated for simultaneous NO _x -soot removal reaction. The performance of LaCo_1?x Pd _x O₃ catalysts were greatly improved by the partial substitution of Pd. The maximum NO conversion into N₂ and the ignition temperature of soot are 32.8% and 265 °C, respectively.     

Effect of Acid–Base Properties on the Catalytic Activity of Pt/Al2O3 Based Catalysts for Diesel NO Oxidation

The activity of Pt catalysts supported on Al₂O₃ modified with various acid–base additives has been investigated for oxidation of NO to NO₂. Although Pt dispersion was changed by the additives, there was no clear effect of Pt dispersion on the catalytic activity. The measurement of solid acid–base properties of the modified Pt/Al₂O₃ indicated that the NO oxidation activity increased by the increase of surface density of strong acid sites and decreased by the increase of basic sites. It was suggested that platinum on the acidic supports keeps its highly active metallic state for NO oxidation, while the formation of nitrate/nitrite on the basic supports inhibits the reaction on the Pt surface.     

The Effect of Copper Substitution on La2Ni1−x Cu x O4 Catalysts Activity for Simultaneous Removal of NOx and Diesel Soot

A series of the La₂Ni_1?x Cu _x O₄ (0 ≤ x ≤ 1.0) perovskite-like complex oxide catalysts, prepared and characterized by XRD, H₂-TPR, O₂-TPD and XPS, and catalytic activity tests, proved to be effective in the simultaneous removal of NOx and soot. The results indicated that the catalysts show the single orthorhombic K₂NiF₄-like phase. The doping of Cu led to the increase of orthorhombic distortion and the decrease of capability to accommodate non-stoichiometric oxygen, as well as the increase of the reducibility of lattice oxygen, resulting in improving catalytic activities. The La₂Ni_0.4Cu_0.6O₄ catalyst showed the highest activity. The maximum conversion of nitrogen oxide to molecular nitrogen was 15.6% and the ignition temperature decreased from 440 to 246 °C, as compared with the uncatalyzed soot combustion reaction.     

Reforming of Diesel Fuel for Hydrogen Production over Catalysts Derived from LaCo1−x M x O3 (M = Ru, Fe)

Catalysts derived from perovskite type oxides LaCo_1?x M _x O₃ (M = Ru or Fe, x = 0.2) synthesized by a modified citrate sol–gel method were tested in the oxidative reforming of diesel for hydrogen production. Physicochemical characterization of the samples revealed differences in the surface area, crystalline size, reducibility and relative distribution of the cobalt active phase on the surface of catalyst. These properties have important implications in the catalytic behaviour of the samples in the oxidative reforming of diesel. The increase in reducibility and metal exposition implies higher reforming activity as it was observed for the catalyst derived from LaCo_0.8Ru_0.2O₃.     

NH3–NO/NO2 SCR for Diesel Exhausts Aftertreatment: Reactivity, Mechanism and Kinetic Modelling of Commercial Fe- and Cu-Promoted Zeolite Catalysts

The activity and the mechanism of the main reactions in the NO/NO₂–NH₃ SCR reacting system were comparatively investigated over a Fe- and a Cu-promoted commercial zeolite catalyst for the aftertreatment of Diesel exhausts. A dynamic micro-kinetic model in close agreement with all the details of the SCR catalytic chemistry was also developed.     

柴油机燃料用ENI淤浆法加氢处理工艺（英文）——ENI Slurry Hydroprocessing Technology for Diesel Fuel，2003，6，44页

附录提供了生产公司专利索引，专利参考文献，设计基础和成本估算及聚苯乙烯、ABS树脂生产的工艺流程图。     

Highly Active La1−x K x CoO3 Perovskite-type Complex Oxide Catalysts for the Simultaneous Removal of Diesel Soot and Nitrogen Oxides Under Loose Contact Conditions

The nanometric La_1?x K _x CoO₃ (x = 0–0.30) perovskite-type oxides were prepared by a citric acid-ligated method. The catalysts were characterized by means of XRD, IR, BET, XPS and SEM. The catalytic activity for the simultaneous removal of soot and nitrogen oxides was evaluated by a technique of the temperature-programmed oxidation reaction. In the LaCoO₃ catalyst, the partial substitution of La³⁺ at A-site by alkali metal K⁺ enhanced the catalytic activity for the oxidation of soot particle and reduction of NO _x . The La_0.70K_0.30CoO₃ oxides are good candidate catalysts for the simultaneous removal of soot particle and NO _x . The combustion temperatures for soot particles over the La_0.70K_0.30CoO₃ catalyst are in the range from 289 to 461 °C, the selectivity of CO₂ is 98.4% and the conversion of NO to N₂ is 34.6% under loose contact conditions. The possible reasons that can lead to the activity enhancement for the K-substitution samples compared to the unsubstituted sample (LaCoO₃) were given. The particle size has a large effect on its catalytic performance for the simultaneous removal of diesel soot and nitrogen oxides.     

Effect of Si-Doping on Thermal Stability and Diesel Oxidation Activity of Pt Supported Porous γ-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Monolithic Catalyst

Abstract  

A series of different contents of Si-stabilized aluminas with high thermal stability were synthesized by the coprecipitation method and were used as the support of Pt diesel oxidation catalysts. The physicochemical properties of SiO₂–Al₂O₃ (SA) and the catalytic performance of Pt/SiO₂–Al₂O₃ (Pt/SA) were characterized in detail by TG–DTA, XRD, infrared spectroscopy, N₂ adsorption, NMR, CO-TPD, and the catalytic activity evaluation of CO and C₃H₆ oxidations as well as NO reduction in simulating diesel exhaust. The results indicate that the presence of Si can remarkably enhance the thermal stability and phase transition temperature of alumina. It was also found that the catalytic activity is virtually independent of surface area, and only appropriate amount of Si doping can improve the diesel oxidation activity, as compared to pure Pt/Al₂O₃ under the same conditions as a result of the better dispersion of Pt on SA–W supports.