Fluid Catalytic Cracking Gasoline Research Articles

Reactive Adsorption Desulfurization of FCC Gasoline over NiO/ZnO-Al2O3-SiO2 in a Fixed-fluidized Bed Reactor

The oxides adsorbent of NiO/ZnO-Al2O3-SiO2 was prepared by a co-precipitation method. NiO/ZnO-SiO2-Al2O3 is an effective adsorbent for reactive adsorption desulfurization of fluid catalytic cracking gasoline. The reaction conditions, such as reaction temperature, total pressure, weight hourly space velocity, and volume ratio of hydrogen to oil for desulfurization over NiO/ZnO-SiO2-Al2O3 in a fixed-fluidized bed reactor were investigated. With the optimum conditions, the sulfur content of FCC gasoline can be decreased from 180 to 11.6 mg·L−1, and the loss of olefin content of gasoline product is 1.05%, the research octane number loss of gasoline product is only 1.3 unit.

An Estimate of the Aromatization Processing Function for FCC Gasoline and LPG

The aromatization reaction of fluid catalytic cracking (FCC) gasoline and C4 liquefied petroleum gas (LPG) have been studied by using three FCC gasolines and three C4 LPGs as raw material and LBO-A as a catalyst. Thus, the aromatization processing function has been put forward. They can predict the gasoline yield and the aromatics yield under various operating conditions and the change trend of Lanlian FCC gasoline, Fushun FCC gasoline, Huabei FCC gasoline, Huabei C4 LPG, Hua'ebin C4 LPG, and Qilu C4 LPG with the change of the aromatics processing function. The calculated values of gasoline production and aromatics yield are close to the experimental values.

The Preparation and Application of a Novel Catalyst for Gasoline Hydrodesulfurization

A novel multifunctional catalyst was prepared and used for hydrodesulfurization of fluid catalytic cracked (FCC) gasoline. The selectivity of hydrodesulfurization increased under the catalysis of Mo-Co-Ni multimetal component catalyst. The amount of the low olefin and the loss of octane number were reduced simultaneously. The sulfur content in FCC gasoline decreased from 1,200 to 115 μg·g−1 and the olefin content dropped from 44.2 to 20.5 vol%. The research octane number (RON) loss was 0.5 units. The stability test of the catalyst indicated that the catalyst was very stable and could run for 2,000 hr.

Effects of composition and morphology of active phase of CoMo/Al2O3 catalysts prepared using Co2Mo10–heteropolyacid and chelating agents on their catalytic properties in HDS and HYD reactions

CoMo/Al2O3 catalysts were synthesised from the ammonium and Co salts of [CoMo6O24H6]3− and [Co2Mo10O38H4]6− anions as well as Co–chelate complexes with nitrilotriacetic, ethylenediaminetetraacetic, citric and tartaric acids. The catalysts were characterised using X-ray powder diffraction, Raman spectroscopy, N2 physisorption, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. The catalysts were tested in the hydrotreating (HDT) of a mixture containing thiophene and n-hexene-1, the hydrodesulphurisation (HDS) of dibenzothiophene and 4,6-dimethyldibenzothiophene and the HDT of diesel. The type of chelating agent significantly affects the structure of the active phase and catalytic properties. The catalytic activity, selectivity and turnover frequency during the HDS and hydrogenation reactions depend on the number and location of CoMoS sites, as well as the shape of the active phase crystallites. New “structure–activity” relationships were established. These approaches yielded catalysts that demonstrated high efficiency towards the deep diesel HDT and selective HDS of a model fluid catalytic cracking gasoline.

Extractive and Catalytic Oxidative Desulfurization of Gasoline by Methyltrioxorhenium in Ionic Liquids

For the first time, methyltrioxorhenium (MTO) is used as a catalyst for the extractive and catalytic oxidative desulfurization (ECODS) of model oil and fluid catalytic cracking (FCC) gasoline, with 30% H2O2 as the oxidant and ionic liquids as the solvent and extractant for the removal of organic sulfur at moderate temperatures (below 60 degrees C). The ECODS is highly efficient with low catalyst loading (1-5 mol %). The mono- and bisperoxorhenium compounds formed via the reactions of MTO and H2O2 are proven to be catalytic active species for the oxidation of organic sulfides, such as thioethers, thiophene, and alkyl thiophenes contained in the FCC gasoline. After the oxidation, the oxidized products were easily extracted into the ionic liquid phase from the oil phase. The sulfur removal can reach up to 99% for the model oil (with an initial sulfur content of 200 mu g/mL) and 91% of the Fushun FCC gasoline (with an initial sulfur content of ca. 142 mu g/mL) within 2 h under the optimized conditions. The octane number of the gasoline is reduced by only about 0.7, without significant changes in hydrocarbon group composition after desulfurization.

Synthesis of ordered hierarchically porous L-SBA-15 material and its hydro-upgrading performance for FCC gasoline

A micro/mesoporous composite L-SBA-15 (LS) material was successfully in situ synthesized using low-cost solid silica–alumina microspheres by a two-step hydrothermal crystallization method, and the as-synthesized material was used as support additive to prepare the hydro-upgrading catalyst for fluid catalytic cracking (FCC) gasoline. LS and the corresponding catalyst CoMo/LS-γ-Al2O3(CoMo/LSA) were characterized by means of XRD, SEM, TEM, nitrogen adsorption, 27Al MAS NMR and Py-FTIR. The physicochemical properties of the CoMo/LSA were compared with those of CoMo/Al2O3 catalyst and the ones incorporated with other different support additives such as zeolite L, SBA-15 and Al-SBA-15. The characterization results demonstrated that LS possessed the typical characteristics of mesoporous silica SBA-15 and microporous zeolite L. The textural properties of the composite material were dramatically improved and the results of acidity measurements indicated that LS exhibited a high acid amount and an appropriate Brönsted and Lewis acid distribution. The catalyst CoMo/LSA showed superior hydro-upgrading catalytic performances, i.e., excellent hydrodesulfurization (HDS), hydroisomerization, aromatization activities and a good preserving ability of the octane number, which can be attributed to the hierarchically porous structure and the properly acidic properties of LS. Thus, LS has potential application for clean gasoline upgrading.

Gasoline Desulfurization by Catalytic Alkylation over Methanesulfonic Acid

Methanesulfonic acid (MSA) was used as catalyst to remove trace organic sulfur (thiophene) from Fluid Catalytic Cracking gasoline (FCC) via alkylation with olefins. The reactions were conducted in Erlenmeyer flask equipped with a water-bath under atmospheric pressure. The influence of the temperature, the reaction time, and the mass ration of MSA were investigated. After a 60 min reaction time at 343 K, the thiophene conversion of 98.7% was obtained with a mass ration of MSA to oil of 10%. The catalyst was reused without a reactivation treatment, and the thiophene conversion reached 92.9% at the third time. The method represents an environmentally benign route to desulfur, because MSA could easily be separated from the reaction mixture via decantation and it could be reused.

An Introduction to the Lump Kinetics Model and Reaction Mechanism of FCC Gasoline

Lump kinetics models and reaction mechanism of fluid catalytic cracking (FCC) gasoline are introduced. Nine lump kinetics model, eight lump kinetics model, ten lump kinetics model, thirteen lump kinetics model, seventeen lump kinetics model, and twenty lump kinetics model have been put forward on the basis of lump theory and the reaction mechanism. In the network, the aromatization reaction species were first lumped into 9, 8, 10, 13, 17, and 20 parts, respectively. A mathematical method is first introduced to calculate a lump model of FCC gasoline. The results from experimental data are in accordance with the quantitative analytical conclusions drawn from the calculated data.

Poly[bis(p-methyl phenyl) phosphazene] Pervaporative Membranes for Separating Organosulfur Compounds from n-Heptane and Its Surface Functionalization

This work investigates the application of poly[bis(p-methyl phenyl) phosphazene] (PMePP) for separating organosulfur compounds from n-heptane. PMePP was synthesized and characterized by NMR, X-ray photo spectroscopy, thermogravimetric analysis, scanning electron microscopy, and Fourier transformed infrared spectroscopy. Membranes based on PMePP were fabricated and investigated for desulfurization of FCC (fluid catalytic cracking) model gasoline by pervaporation. The effects of operating temperature, feed composition, and feed sulfur content on the performance of PMePP membranes were investigated. The experimental results showed that the PMePP-based membranes are effective for FCC gasoline pervaporative desulfurization. To provide active spots for future grafting modification, the surface functionalization of PMePP was carried out to convert the methyl units into carboxylic units. The surface-functionalized membrane was also investigated for its pervaporation performance, and results showed the increased in enrichment factor and less temperature dependence.

Desulfurization of Fluid Catalytic Cracking Gasoline by Extractive Distillation Coupled with Hydrodesulfurization of Heavy Fraction

Desulfurization of a fluid catalytic cracking (FCC) gasoline by extractive distillation was investigated. A modified Ellis dual-circulating vapor–liquid distiller was used to measure vapor–liquid equilibrium data of the FCC gasoline and various solvents. N-Formyl morpholine (NFM) was selected as the solvent for extractive distillation desulfurization. The desulfurization effect of FCC gasoline was investigated on a continuous extractive distillation column. At the optimal conditions, the distillate yield reached to 64.18 vol %, and sulfur content was 26.03 mg·L–1. After that, the heavy fraction was hydrodesulfurized on a FGH-31 catalyst in a fixed bed reactor. Results showed that the sulfur compounds in the heavy cut could be reduced to 9.5 mg·L–1. Light fraction of the extractive distillation and the hydrodesulfurized heavy cut are of primer blending compounds for producing low sulfur gasoline.

Coke Deactivation Kinetics for FCC Gasoline and C4 LPG

The aromatization reaction of fluid catalytic cracking (FCC) gasoline and C4 liquefied petroleum gas (LPG) has been studied by using three FCC gasolines and three C4 LPGs as raw material and LBO-A as a catalyst. The reaction mechanism, the relationship between aromatics production yield and aromatization processing function, and coke deactivation kinetics are explained in detail. The calculated values are almost close to the experimental values and can predict the catalyst coke yield very well for the different FCC gasolines and C4 LPG.

An insight into effect of methanol on catalytic behavior of Amberlyst 35 resins for alkylation desulfurization of fluid catalytic cracking gasoline

Alkylation desulfurization of fluid catalytic cracking (FCC) gasoline over solid acid catalysts is considered to be a viable path to meet environmental regulations of sulfur emissions. However, side reactions in the process such as alkenes oligomerization and aromatic alkylation lead to the formation of significant amounts of coke, which will greatly reduce the catalyst lifetime and require keeping high catalyst selectivity for thiophenic compounds alkylation. In this paper, both the experimental and theoretical investigations were carried out to further explain the effect of methanol on the catalytic behavior of macroporous sulfonic resins Amberlyst 35 (A35) in the alkylation desulfurization process of FCC gasoline. The results indicated that adding suitable amount of methanol (about 1.0wt% of the feed gasoline) was beneficial to improve the catalytic behavior of A35 in this process. The competition adsorption of suitable amount of methanol and its ether product with isoalkenes could greatly reduce the activated alkenes on the acid sites of A35 and have little impact on the alkylation of thiophenic sulfurs. They could also decrease the alkenes conversion for side reactions of alkenes oligomerization, which was favorable for improving the catalytic selectivity for thiophenic compounds alkylation and prolonging the catalytic lifetime of A35.

Mass transfer of hydroxyethyl cellulose membranes for desulfurization of FCC gasoline: Experimental and modeling

Hydroxyethyl cellulose (HEC) pervaporation membranes were employed for the desulfurization of fluid-catalytic-cracking (FCC) gasoline. Based on solution-diffusion mechanism, the solubility of sulfur during the pervaporation process was studied by carrying out experiments and modeling, and UNIFAC-FV, UNIFAC-ZM, and Entropic-FV models were compared. The results show that the prediction by UNIFAC-FV model is more accurate than the other two models, especially when the sulfur mass fraction in the feed is <4000μgg−1. The mass fraction of sulfur adsorbed onto the polymer surfaces increases with increasing temperature and sulfur content in the feed, and the latter is more effective than the former. The distribution coefficients of thiophene and n-heptane were calculated by using UNIFAC-FV model, and further compared to the experimental results.

In Situ Upgrading of Light Fluid Catalytic Cracking Naphtha for Minimum Loss

The key to reducing the olefin content in fluid catalytic cracking (FCC) gasoline is to upgrade the olefin-rich light FCC naphtha (LCN). To minimize the naphtha loss, several parameters were investigated in a pilot-scale riser FCC apparatus. The results indicate that, besides the reaction temperature, the catalyst-to-oil ratio, and the catalyst type, the boiling range and the olefin content of LCNs also have significant influence on the upgrading effect. Moreover, a relatively short residence time is beneficial for efficiently upgrading LCNs. In addition, the influence of the reactor structure should be brought to our attention. When a novel structurally changed reactor with a multinozzle feed system was used, significantly increased olefin conversion and decreased naphtha loss can be achieved. The calculation of hydrogen balance indicates that, because of the decrease of dry gas and coke yields, more hydrogen in the feed can be distributed into the desired products.

Enhancing FCC gasoline desulfurization performance in a polyphosphazene pervaporative membrane

Nowadays, pervaporation is widely investigated as a promising process in FCC (fluid catalytic cracking) gasoline deep desulfurization, in which the membrane plays a decisive role. In this work, a membrane with high desulfurization performance was initiated and its pervaporation performance was evaluated using FCC model gasoline composed of thiophene and heptane. The membrane was prepared from chlorine incompletely substituted poly [bis (phenoxy) phosphazene] (Cl-PBPP) followed by simple self-crosslinking at room temperature. Compared with previous jobs, the Cl-PBPP is 12times increased in pervaporation separation index. Moreover, via self-crosslinking the trade-off effect is eliminated. The highest enrichment factor and flux of Cl-PBPP membrane for separating thiophene from heptane are 5.6 and 1.38kg/(m2h), respectively. The obtained results are promising for industrial trial.

Synergistic Process for Coker Gas Oil Catalytic Cracking and Gasoline Reformation

The most critical problem of processing coker gas oil (CGO) is its high nitrogen content, especially the basic nitrogen compounds, which limits its cracking performance in the fluid catalytic cracking (FCC) process. For enhancing the conversion of CGO, three processing schemes were evaluated in a pilot-scale riser FCC unit. Four indexes (thermal cracking index, dehydrogenation index, hydrogen transfer coefficient, and isomerization reaction index) were used to investigate the effects of operating conditions on the reactions of CGO cracking. Results show that the optimal operating conditions for CGO cracking are high reaction temperature and large catalyst-to-oil ratio with a short residence time. Therefore, we proposed a synergistic process by selectively recycling light FCC gasoline (LCG) from the upper position of the riser reactor, which can provide a high-severity reaction zone for CGO cracking and a low-severity reaction zone for gasoline upgrading. To further investigate the mutual effect of the two...

Ionic Liquid‐Coated Nickel Phosphide Catalysts for Selective Hydrodesulfurization

AbstractNi2P/SiO2 catalysts were coated with the ionic liquid (IL) 1‐butyl‐3‐methylimidazolium bis[(trifluoromethyl)sulfonyl]amide with different coating thicknesses and their selective hydrodesulfurization performances were investigated using a model fluid catalytic cracking gasoline. The selective factor on the IL‐coated catalysts (IL‐Ni2P/SiO2) first increased and then decreased as the initial mass ratio of IL to Ni2P/SiO2 catalyst ranged from 0.02 to 0.18. A maximum selectivity factor of 16.7 was found at a mass ratio of 0.10 which corresponds to full monolayer coverage on the original Ni2P/SiO2 catalyst by the IL. In comparison, the selectivity factor was 6.7 for the Ni2P/SiO2 catalyst, indicating a significant selectivity improvement by the IL coating method.

Multifunctional Two-Stage Riser Catalytic Cracking of Heavy Oil

The continuous deterioration of feedstocks, the increasing demand of diesel, and the increasingly strict environmental regulations on gasoline call for the development of fluid catalytic cracking (FCC) technology. To increase the feed conversion and the diesel yield as well as produce low-olefin gasoline, the multifunctional two-stage riser (MFT) FCC process was proposed. Experiments were carried out in a pilot-scale riser FCC apparatus. Results show that a higher reaction temperature is appropriate for heavy cycle oil (HCO) conversion, and the semispent catalyst can also be used to upgrade light FCC gasoline (LCG). The synergistic process of cracking HCO and upgrading LCG in the second-stage riser can significantly enhance the conversion of HCO while reducing the olefin content of gasoline at less expense of gasoline yield. Furthermore, the novel structure riser reactor can increase the conversion of olefins in gasoline. Because of the significant increase of HCO conversion, the fresh feedstock can be cr...

Process Simulation Based on Experimental Investigations for 3-Methylthiophene Alkylation with Isobutylene in a Reactive Distillation Column

A new approach that substitutes the original two-step olefinic alkylation of thiophenic sulfur (OATS) technology with a reactive distillation (RD) column was proposed to remove sulfur compounds from fluid catalytic cracking (FCC) gasoline. 3-Methylthiophene (3MT) and isobutylene (IB) were designated as the model compounds for sulfide and olefin, respectively; NKC-9 cation exchange resin mixed with the 2 mm × 2 mm θ ring packing was used as the catalyst bed. The process parameters such as feed composition, molar ratio of 3MT to IB, and reflux ratio were investigated experimentally in the RD column. Simulation for this process was carried out by using the equilibrium stage model—the RADFRAC module of Aspen Plus. The multicomponent vapor–liquid equilibria were predicted by an UNIQUAC method, and the kinetics model that is essential in the RD process was obtained from our previous work. The key design factors (e.g., number of reactive and nonreactive stages, location of feed stage, column pressure, mass ratio...

Gasoline Desulfurization with Two Catalytic Distillation Columns

A new approach was proposed to remove sulfuric compounds from fluid catalytic cracking (FCC) gasoline by combining an alkylation desulfurization catalytic distillation (ADCD) column with a hydrodesulfurization catalytic distillation (HDS-CD) column. In the ADCD column, isobutylene (IB) and 3-methylthiophene (3MT) were designated as the model compounds for olefin and sulfide, respectively; NKC-9 cation exchange resin was used as the catalyst. In the HDS-CD column, dibenzothiophene (DBT) was chosen as the model sulfides; Nickel phosphide supported on the TiO2-Al2O3 composite oxide prepared by our laboratory were designated as the HDS catalyst. Simulations for these two CD columns were carried out by RADFRAC module of Aspen Plus. The optimization results revealed that the ADCD column had an alkylation selectivity of 96%, and the sulfur content in the overhead stream was less than 8 μg/g. The simulation results of the HDS-CD process showed that the sulfide in the bottom stream of ADCD column can be removed practically by 100% and the clean oil stream from the bottom of HDS-CD column has hardly any sulfur.