Study on Desulfurization of Gasoline by Electrochemical Oxidation and Extraction

In order to further reduce the sulfur content in gasoline, a new desulfurization process was proposed by using catalytic oxidation and extraction realized in an electrochemical fluidized reactor. The fluidized layer of loaded catalyst particles consisted of lead dioxide (PbO2) supported on activated carbon particles (PbO2/C) and the electrolyte was aqueous NaOH solution. The PbO2/C particle anodes could remarkably accelerate the electrochemical reaction rate and promote the electrochemical catalysis of sulfur compounds. The sulfur compounds were at first oxidized to sulfones or sulfoxides, which were then re- moved after extraction. The experimental results indicated that the optimal desulfurization conditions were as follows: The cell voltage was 3.2 V, the concentration of hydroxyl ions in electrolyte was 0.12 mol/L, and the feed rate was 300 mL/min. Under these conditions the concentration of sulfur in gasoline was reduced from 310 ppm to 70 ppm. Based on these experimental results, a mechanism of indirect electrochemically catalytic oxidation was proposed.     

Study on Disproportionation Reaction of FCC Gasoline on Acid Catalyst

Based on the experimental data relating to the reaction of FCC gasoline on acid catalyst the analysis of product distribution, and composition of gasoline and diesel fractions have been analyzed. The occurrence of disproportionation reaction of FCC gasoline on acid catalyst and the network of disproportionation reaction have been identified. Study has also shown that different reaction temperatures can result in different pathways of disproportionation reactions on acid catalyst.     

Study on Reaction Mechanism for Cracking FCC Gasoline on Acid Catalyst

This article is based on the experimental data on reaction of FCC naphtha in the presence of acid catalysts. The data published in the literature were reprocessed and compared with experimental data and the relationship of hydrogen and methane contained in the dry gas with the conversion rate was identified. The similarity between the route for cracking of olefin enriched FCC gasoline and the route for reaction of individual hydrocarbons was deduced, while the route for formation of ethylene in dry gas was also proposed to identify the relationship between the reaction path for formation of ethylene and the conversion rate.     

Study on Modified Y Zeolites and Their Behaviors in Selective Adsorptive Desulfurization of FCC Gasoline(Ⅰ)

Na Y zeolite was modified through dealumination with oxalic acid,and the HY zeolite was obtained by calcination of the modified NaY zeolite.The zeolite molding process was carried out at ambient temperature(25℃),and the influence of solid/fuel mass ratio and adsorptive desulfurization time on the HY zeolite were investigated through tests on static selective adsorptive desulfurization of FCC gasoline containing organic sulfur compounds(with a S content=135 ppm).The sulfur content and sulphide types in the FCC gasoline were analyzed by a GC 2010 sulfur analyzer and a GC-SCD chromatograph.The test results showed that the molded HY zeolite was better than the unmolded HY zeolite.At a static adsorptive desulfurization time on the molded HY zeolite equating to 6 hours,a solid/fuel mass ratio of 1:3,the sulfur content of FCC gasoline was decreased to 30 ppm,and the desulfurization rate was equal to 78%.When the breakthrough point of the molded HY was equal to 50 ppm,the molded HY zeolite was capable of adsorbing 4.86 mg of sulfur per gram of adsorbent.And the regeneration rate of molded HY zeolite was equal to 98%.     

Application of High Shear Agitation for Desulfurization of Gasoline Using Ionic Liquids

The high shear agitation device was first adopted for gasoline desulfurization by ionic liquids. The effect of benzylimidazol fluoborate in desulfurization of gasoline and the influence of moisture on deuslfurization rate were investigated. The experimental results showed that the ionic liquid could effectively decrease the sulfur content of gasoline and the optimal conditions were as follows: The reaction could be carried out at room temperature, a volumetric ratio between oil and the liquid of 2∶1, a volumetric ratio between water and ionic liquid of 0.04∶1, a rotational speed of 5 krad/s, and a reaction time of 1 minute. The desulfurization rate of gasoline reached 53.6%, and the gasoline yield was up to 97.3%. The ionic liquid could be recycled for repeated use, and the use of high shear agitation for gasoline would have good prospects.     

Study on Modified Y Zeolites and Their Behaviors in Selective Adsorptive Desulfurization of FCC Gasoline （II）

Ce (Ⅲ) Y zeolite was prepared by liquid-phase ion-exchange of NaY with 0.1 mol/L Ce(NO3)3 solution at 100℃ for 4 h. After calcining the resultant Ce (Ⅲ) Y zeolite at 550℃in air, Ce (Ⅳ) Y zeolite was obtained. Desulfurization of FCC gasoline was studied by selective adsorption with Ce (Ⅳ) Y zeolite. The results showed that Ce (Ⅳ) Y zeolite can remove thiophene via d-complexation directly, while thiophene and Ce (Ⅳ) can form stable chemical bonds (sulfur-metal bonds) that can enhance the capability of Ce (Ⅳ) Y zeolite for adsorption of thiophene.     

Study on Reduction of Sulfur Content in FCC Gasoline

Reduction of sulfur content in FCC gasoline was studied in a fixed fluid bed (FFB) unit by using metal-modified LV-23 FCC catalyst. The results showed that the sulfur content in FCC gasoline could be reduced with LV-23 catalyst modified with zinc, palladium, zinc-palladium, zinc-cobalt, and zinc-nickel. Among these metals or metal combinations, palladium-containing catalyst was the most effective. Desulfufization of the heavy fraction of FCC gasoline was more effective than full-range gasoline under the same conditions with palladium-containing catalysts. A high reaction temperature was favorable to desulfurization, but it would reduce the yield of liquid product. After desulfurization reaction, the olefm content of product gasoline decreased while the aromatic and iso-alkane contents increased. Removal of thiophene and benzothiophene is higher.     

Analysis of Factors Affecting Olefin Content in FCC Gasoline

In order to meet the urgent need for reducing olefin content in cracked naphtha,the influence of feedstock characteristics on the olefin content was discussed.The different types and perfomance of catalysts developed by RIPP were introduced,Moreover,some effective operation approaches in commercial units presented to serve as a reference to the refiners for catalyst selection.     

Etherification of FCC Light Gasoline over Mo-Modified β Zeolite Catalyst

Abstract

Etherification activity of several molecular sieve catalysts for FCC light gasoline was studied in a fixed-bed reactor. H-Beta zeolite was found to be high active than that of others and close to cation exchanged resin catalyst. H-Beta zeolite also showed good activity and selectivity and could not be deactivated easily, and could be easily regenerated after deactivation. In order to further improve etherification activity, the surface acidity and pore structure of zeolite could be modified, by loading different metal oxides. The result showed that the highest conversion of tert-olefin was obtained over Mo/Hβ (1%). The influence of reaction temperature, methanol and tert-olefin molar ratio, reaction pressure, and LHSV on the conversion was investigated. At optimized reaction conditions, tert-olefin conversion of 57.42% had been reached with Mo/Hβ (1%).     

Selective Hydrodesulfurization of FCC Gasoline Using LH—07 Catalyst

1.Introduction Since the environmental regulations are increasingly strin gent than ever, the production of clean automobile fuel is a vital target in China, especially after China has become a WTO member. However, the sulfur content in gasoline pool of China is still very high. Over 95% of the sulfur in gaso line pool comes from FCC naphtha. It is necessary to remove sulfur in FCC naphtha.     

Study on Commercial Application of FCC with Auxiliary Gasoline Reactor for Improving FCC Naphtha Quality

This article introduces the commercial application of FCC technology equipped with a gasoline auxiliary reactor in the RFCC unit at PetroChina Harbin Petrochemical Branch Company. Test results have shown the excellent outcome for commercial application of the gasoline upgrading in the auxiliary reactor to reduce the olefin content in FCC naphtha. Application of this technology can reduce the olefin content in FCC naphtha to less than 35 v%. Adjustment of the FCC operation towards more severe conditions can further reduce the olefin content in FCC naphtha to less than 20 v%, so that the FCC naphtha can meet the current standard or meet more stringent specification requirements in the future to achieve compelling economic and social benefits.     

A “Green” Cyclohexanone Oxidation Route Catalyzed by Hollow Titanium Silicate Zeolite for Preparing ε-Caprolactone,6-Hydroxyhexanoic Acid and Adipic Acid

Hollow titanium silicalite (HTS) molecular sieve has been synthesized, and information on its structure, physico-chemical characterization, as well as surface property was investigated by a host of analytical methods, such as XRF, XRD, low-temperature N2 adsorption/desorption, TEM, FT-IR, UV-Vis, 29Si MAS NMR, and XPS techniques. The characterization results suggest that HTS zeolite has a special hollow crystal structure and its mesopore volume is larger than that of TS-1 zeolite. The titanium species in this zeolite are composed of the framework tetrahedral Ti (IV) ions and extra-framework octahedral Ti (IV) ions, which tend to disperse into its bulk phase. This zeolite material also has been applied to catalyze the cyclohexanone oxidation process, and the products are not completely consistent with those results obtained by using TS-1 zeolite, which might be caused by their difference in pore structure and pore volume, especially the mesopore volume. Cyclohexanone oxidation catalyzed by HTS zeolite is a representative consecutive reaction, the main target products of which are e-caprolactone, 6-hydroxyhexanoic acid and adipic acid. The effect of H2O2/cyclohexanone mole ratio on the cyclohexanone conversion, the total target product selectivity, the distribution of three target products selectivity and their variations along with reaction time is also researched and analyzed, which indicate that HTS zeolite shows a high performance for the Baeyer-Villiger reaction of cyclohexanone and catalytic oxidation of 6-hydroxyhexanoic acid under mild conditions, and the quantity of active surface titanium species as well as the pore structure and mesopore volume controlling the mass diffusion rate are the key factors determining the catalytic activity of HTS zeolite and product selectivity.     

Commercial Test of HGY-2000R FCC Catalyst for Maximizing Gasoline Yield

HGY-2000R catalyst developed by Research Institute of Petroleum Processing, SINOPEC was tested in the RFCC unit, Ulsan complex, SK Corporation, Korea from July to August 2002. The primary results of commercial test show that it has good performance of higher activity, good hydrotherrnal stability,higher residue cracking ability, good coke selectivity and good fluidization properties as well as maximizing gasoline yield with a lower olefin content.     

Desulfurization From Model of Gasoline by Extraction With Synthesized [BF4]−- and [PF6]−-based Ionic Liquids

Abstract

The authors report that 1-octyl-3-methylimidazolium tetrafluoroborate, [OMIM][BF₄], and 1-butyl-3-methylimidazolium hexafluorophosphate, [BMIM][PF₆], ionic liquids were synthesized and tested for their capability to desulfurization from model of gasoline. The results show that the aromatic sulfur compounds with higher π-electron density were favorably adsorbed. The results also show that [BF₄]^?-based ionic liquid displays higher extraction efficiencies than [PF₆]^?-based ionic liquid. Thus, it was shown that the extractive ability of the imidazolium ionic liquids was dominated by the structure of cation and anion. It is also found that the sizes of ionic liquids are important factors affecting the absorption capacity for aromatic sulfur compounds.     

Improving Stability of Gasoline by Using Ionic Liquid Catalyst

The composition, characteristics and preparation of ionic liquids are presented. The factors influencing the stability of gasoline and the significance of improving gasoline stability are discussed. A novel way to improve the stability of gasoline by using ionic liquid catalyst is developed. The contents of olefin, basic nitrogen and sulfur in gasoline are determined and the optimal experimental conditions for improving gasoline stability are established.The ionic liquid catalyst, which is environmentally friendly, can reduce the olefin content in gasoline, and such process is noted for mild reaction conditions, simple operation, short reaction time, easy recycling of the ionic liquid catalyst and ready separation of products and catalyst.     

Commercial Test of Multi-functional Desulfurizing Agent TS-01 for Gasoline in FCC Process

Experimental use of multi-functional desulfurizing agent TS-01 for FCC gasoline in the FCC unit of SINOPEC Jiujiang Company shows that the multi-functional desulfurizing agent can effectively remove various kinds of sulfur in FCC gasoline and diesel fuel and fulfill passivation on heavy metals.     

A New Approach to Dearomatization of Gasoline by Ionic Liquid and Liquid–Liquid Extraction

Abstract

The objective of this article was the development of a separation technology for the selective recovery of the aromatic compounds such as benzene, toluene, ethylbenzene, and xylenes (BTEX) from gasoline by extraction. A liquid–liquid extraction method using ionic liquid (IL) was optimized simultaneously for some aromatic hydrocarbons in gasoline. 1-Butyl-3-methyl imidazolium tetrachloroaluminate ionic liquid or [BMIM][AlCl₄] was used to extract aromatic compounds from gasoline. [BMIM][AlCl₄] was found to be effective for the selective removal of aromatic hydrocarbons from gasoline. The dearomatization experiments were carried out with a 1:1 volume ratio of ionic liquid to gasoline for 60 min at 50°C. The aromatic hydrocarbons removal selectivity followed the order benzene > toluene > xylene > ethylbenzene.     

Kinetic Pecularities of Benzene Production from the Benzene–Toluene–Xylene Fraction of Pyrolysis Gasoline by Catalytic Hydrodealkylation at High Temperature

Abstract

Hydrodealkylation (HDA) of the benzene–toluene–xylene (BTX) fraction of pyrolysis gasoline is an industrial route to produce benzene. Complicated kinetics of aromatic and nonaromatic hydrocarbon reactions has been experimentally investigated at the conditions of this process, employing a polyfunctional Al–Cr–KF catalyst with a high benzene selectivity, model feeds and BTX. The study reports effects of nonaromatic hydrocarbons on high temperature catalytic conversion of toluene. Above 525°C the process is found to be thermo-catalytic meaning that reactions take place on the catalyst surface and between catalyst pellets. The “pure” catalytic component of conversion is taken to be the difference between a thermo-catalytic and a thermal (i.e., without catalyst) run at the same conditions. Nonaromatic hydrocarbons substantially boost interpellet toluene HDA which is explained by a mechanism involving very fast decomposition of the nonaromatics into active radicals. The accompanying slight fall in catalytic toluene HDA, on the other hand, is considered to be due to nonaromatics and/or their hydrocracking products impeding toluene diffusion to the catalyst surface whose active centers they partially occupy. There is evidence that the C6–C8 nonaromatics of BTX influence the toluene conversion in the same manner as n-octane and cyclohexane. Benzene seems to render a small fall in surface conversion of toluene probably by inhibiting its diffusion. It apparently has no significant influence on nonaromatic hydrocracking or thermal toluene HDA. The hydrocracking products of the model feeds and BTX are 97–99 mol% C1–C4 alkanes and 1–3 mol% C2–C4 alkenes irrespective of the run type (i.e., thermal or catalytic). Moreover, given more time the hydrocracking reactions in the voids surpass those on the catalyst surface. Changing hydrogen:BTX molar ratio from 1.5 to 10 raises thermal (respectively “pure” catalytic) contribution significantly (respectively slightly) to conversions of toluene, C8 aromatics, n-octane, cyclohexane, and other C6–C8 nonaromatics.     

Highly Selective Conversion of Olefin Components in FCC Gasoline to Propylene in Monolithic Catalytic Reactors

1 Introduction Monolithic reactors have found applications in industrial cata- lytic processes[1]. One of such successful examples is its ap- plication as the mobile exhaust cleaning catalysts installed on thousands of vehicles. The reduction of SOx and NOx from a fixed source is another commercial application. Recently, monolithic catalysts and reactors as an interesting technol- ogy applied in multiphase catalytic processes have been at- tracting more attention[2]. Some chemical and refini…     

Alkylation of Benzene with Propylene Catalyzed by Ionic Liquids

1. Introduction The alkylation of benzene with propylene produces cumene, a very important petrochemical feedstock used for the production of phenol and acetone (Yang, 1990). More than 90% of the global phenol demand is derived from cumene. Hence, the growth rate of cumene production is closely associated with that of phenol. Cumene demand is expected to grow by about 3.5% annually over the next 5 years (Kleinloh, 1997). The global cumene capacity from some 40 plants worldwide is about 8 mil…