Gasoline Olefins Research Articles

Investigation of the Operating Conditions on Decreasing FCC Gasoline Olefin Content by GOR-Q Catalyst

Based on a fixed-fluid-bed reactor and a GOR-Q catalyst, the influence of process parameters on decreasing gasoline olefin content was studied. The results show that the catalyst had an obvious effect on the decreasing gasoline olefins. A higher catalyst-to-oil ratio, lower weighted hourly space velocity, and lower reactor temperature give rise to lower gasoline olefin content. The reduction of fluid catalytic cracking (FCC) gasoline olefin content is achieved by decreasing olefins of low carbon number. Reaction temperature under 520°C and catalyst-to-oil ratio = 7.0 for a GOR-Q catalyst are advantageous for decreasing olefin content of FCC gasoline.

Influence of Shaping Condition on Etherification Performance of Hβ Zeolite

Etherification reaction of FCC light gasoline over Hβ zeolite was investigated to decrease the light olefins in motor gasoline while enhancing octane. Etherification activity of several molecular sieve catalysts for FCC light gasoline was studied in a fixed-bed reactor. The influence of pore-enlarging agent (PEG) with different molecular weight, binder (γ-Al2O3), and peptizing agent (HNO3) in the shaping process on etherification activity of Hβ zeolite was studied. The impregnating ways of precursor of oxides and the order of extruding and impregnating were also investigated. The results show that the activity of extruded Hβ zeolite before impregnating precursor of oxides is higher than the reverse order. The best shaping condition obtained was PEG-4000 10%, γ-Al2O3 20%, and HNO3 10%. At the optimal reaction condition, the conversion of tert-olefins reached the peak. 62.93%, the yield of TAME, is also high and the technology can be applied to industry as well.

Deep Desulfurization of Gasoline by Selective Adsorption over Nickel-Based Adsorbent for Fuel Cell Applications

Adsorptive desulfurization of model gasoline fuels and a real gasoline over a nickel-based adsorbent Ni−Al was conducted in a flowing adsorption system at a temperature range of 25−200 °C under ambient pressure without using H2 gas in order to evaluate the desulfurization performance of the adsorbent for producing ultra-low-sulfur gasoline for fuel cell applications. Adsorptive capacity and selectivity of the Ni−Al adsorbent for various sulfur compounds and the effects of coexisting olefin in gasoline as well as adsorptive conditions on the adsorptive performance were examined. It was found that the nickel-based adsorbent shows high capacity and selectivity for the adsorptive desulfurization of gasoline. Olefins in gasoline have a strong inhibiting effect on the desulfurization performance of the nickel-based adsorbent at room temperature. Increasing the temperature to 200 °C can significantly improve the desulfurization performance of the nickel-based adsorbent for real gasoline. The adsorption mechanism and selectivity are discussed on the basis of the experimental results and computational analysis. The adsorption of sulfur compounds on the nickel surface involves C−S bond cleavage, as evidenced by the formation of ethylbenzene from benzothiophene in the absence of H2 gas in the flow adsorption system.

A reactive analytical approach for the estimation of olefinic content in gasoline-range hydrocarbons by gas chromatography.

The estimation of olefinic content in conversion processes such as the etherification of olefins in fluid catalytic cracking (FCC) gasoline is essentially required. Gas chromatography (GC) is the well-established method for the quantitative analysis of olefins in etherification processes. The current state-of-the-art GC methods employing highly specific long single capillary columns such as Petrocol-DH are being used for the analysis of gasoline-range hydrocarbons. However, the method needs many standard reference samples of respective components in a complex mixture of hydrocarbons, which limits the scope of the analytical method. The alternative approach followed by this investigation is based on the reactive method of the analysis of olefins in FCC light gasoline by subjecting them to hydrogenation and estimating the olefinic content by GC comparing the gas chromatograms of the original feed and hydrogenated product using a Petrocol-DH column. A decrease in the quantity and disappearances of the peaks are assumed as olefins, and their number and total composition is calculated. In this study the bromine number method is used to estimate the olefinic content for a comparison of results with the adopted proposed methodology. The adopted methodology quantitates olefinic content in FCC light gasoline, which is comparable with reported literature values and the bromine number method. With the availability of standard reference samples of some important major reactive olefins, the adopted methodology can also give component-wise analysis as well as total olefinic content in a single step in processes such as etherification. The methodology can be also useful in reactions in which the conversion of total olefinic content is needed such as hydration, esterification, and alkylation of olefins in a complex mixture of hydrocarbons apart from the etherification of olefins in FCC gasoline.

ATMOSPHERIC RESIDUE AS FEEDSTOCK TO HIGH-SEVERITY FLUID CATALYTIC CRACKING

ABSTRACT The effect of atmospheric residue as a feedstock to a high-severity fluid catalytic cracking (HS-FCC) process has been investigated using a small-scale HS-FCC pilot plant (0.1 b/d) with a down flow reactor. This novel FCC process has been developed to enhance the yield of light olefins under high severity reaction conditions. Hydrotreated and virgin vacuum gas oils (VGO) as well as hydrotreated and virgin atmospheric residues (AR) were tested in the study. The yield of desired products such as gasoline and light olefins produced from virgin VGO cracking was 79 wt%, much higher than that obtained from a conventional FCC process whereas in case of hydrotreated VGO, the yield of desired products decreased to 76%. On the other hand, AR feeds exhibited performance similar to VGO with a slight increase in coke formation.

ZSM-5 Additive in Fluid Catalytic Cracking. 1. Effect of Additive Level and Temperature on Light Olefins and Gasoline Olefins

The effects of ZSM-5 additive and riser reactor temperature on the product selectivity in fluid catalytic cracking of gas oil were systematically investigated in an adiabatic circulating riser reactor. In addition to the fact that ZSM-5 can substantially increase propylene and butene, it is found that ethylene yield linearly increases with the amount of ZSM-5 in the system. The ethylene is likely from the overcracking of C5 and C6 olefins. The effect of ZSM-5 on gasoline range olefins was clarified. In the temperature range of 794−839 K (970−1050 °F) studied in the current work, ZSM-5 additive always reduces C6 + olefins. The effect of ZSM-5 on C5 is different. C5 olefin increases at 794 K, but decreases at 839 K. Since C5 olefins account for about one-third to one-half of the gasoline olefins, the overall gasoline olefin contents were dominated by the behavior of C5 olefins. Compared with the effect of ZSM-5, the effects of temperature on light olefins are relatively small. Most of the olefin increases w...

Gasoline selective ZSM-5 FCC additives: Model reactions of C 6–C 10 olefins over steamed 55:1 and 450:1 ZSM-5

The reactions of C 6–C 10 olefins over a 55:1 SiO 2/Al 2O 3 ZSM-5 and a 450:1 ZSM-5 catalyst were studied, in order to understand the origin of the relatively low gasoline loss per octane gain observed when high-silica “gasoline selective” ZSM-5 is added to the FCC. The ratio of isomerization to cracking rates for hexene and octene was higher over the 450:1 catalyst; isomerization to more highly branched olefins can increase gasoline octane rating with no gasoline yield loss. Also, the cracking rates of the higher (e.g. C + 8) olefins, compared to cracking of C 7− olefins, were higher for the 450:1 ZSM-5. Thus, for a given amount of cracking of the higher gasoline olefins, more of the lighter (C 5–C 7) olefins will be retained in the gasoline. The cracking of higher olefins can boost octanes through removal of low-octane long-chain olefins, which also serves to prevent formation of very low octane long-chain paraffins from these olefins by hydrogen transfer over the base catalyst, and by formation of high-octane branched C 5–C 6 olefins. Compared to reactions over the 55:1 ZSM-5, the rates of the fastest reactions (cracking of higher olefins and isomerization), which tend to boost octane with little or no gasoline yield loss, are accelerated over the 450:1 ZSM-5 relative to the slower reactions (cracking, especially of C 5–C 7 olefins), which tend to reduce gasoline yield with less gain in octane. These reactivity patterns can largely explain the higher gasoline selectivity observed commercially for the high-silica ZSM-5 FCC additives. A likely basis for these differences in reactivity is that the less-active high-silica ZSM-5 is less subject to diffusional limitation of reaction rates.

Application of oxymercuration-demercuration for analysis of olefins in pyrolysis gasoline

Application of oxymercuration-demercuration for analysis of olefins in pyrolysis gasoline

Method of determining normal paraffin and olefin hydrocarbons in gasoline and diesel fractions of secondary processes of oil refining

1. A method was proposed for determining the content of paraffins and olefins in gasoline and diesel fractions, using synthetic zeolites. 2. The method was extremely simple and does not require complex apparatus; the amount of the sample for analysis does not exceed 1–2 ml. 3. The error of the determination does not exceed 2% abs., or 14% rel. The discrepancy between parallel determinations is no more than 1%. 4. The zeolites used for the quantitative determination of normal hydrocarbons should posess a capacity with respect to n-heptane of no less than 8 g/100 g of zeolite.

The magnetohydrodynamic squeeze film : D. C. Kuzma, E. R. Maki and R. J. Donelly, J. Fluid Mech., 19 (3) (1964) 395–400

The growing interest of chemical and oil refining industries in the catalytic oligomerization of alkenes for the production of synthetic fuels and additives formulated around light gasoline olefins is due to recent environmental restrictions and increasing diesel demand. Furthermore, the drive towards sustainability and the emergent contribution of biorefineries for the manufacture of intermediate and platform chemicals envisages olefins produced from biomass derived alcohols as an important feedstock for subsequent oligomerization.Over the last years much work has been published on the catalytic oligomerization of propene, butene, isobutene and isoamylene over cation exchange resins, such as Amberlyst and Purolite, and others like Nafion. For instance, isobutene dimers and trimers are accepted additives for gasoline (octane booster) and diesel (cetane booster) while isobutene higher oligomers can be a source for heavier fuels and synthetic lube oils. This paper presents a deep and critical review in the field discussing the influence of the resin (resin-type and their physical and structural properties), the operating conditions and additives used (polar compounds like alcohols), upon oligomerization conversion and selectivity.

Determination of Olefins in Gasoline

Determination of Olefins in Gasoline

Correspondence. Determination of Olefins, Aromatics, Paraffins, and Naphthenes in Gasoline

Correspondence. Determination of Olefins, Aromatics, Paraffins, and Naphthenes in Gasoline

Determination of Olefins, Aromatics, Paraffins, and Naphthenes in Gasoline

Determination of Olefins, Aromatics, Paraffins, and Naphthenes in Gasoline