Production of Linear Octenes from Oligomerization of 1-Butene over Carbon-Supported Cobalt Catalysts

Abstract

Linear octenes were produced in high (70–85%) selectivity from oligomerization of liquid 1-butene using carbon-supported cobalt oxide catalysts in a continuous flow reactor. The liquid products were characterized by two-dimensional gas chromatography–mass spectrometry. Above 95% of the oligomers were C8 olefins, with the other products primarily being branched C12 olefins. The linear octene products at a conversion of 9.77% decreased in selectivity according to 3-octene > trans-2-octene > cis-2-octene > 4-octene. Methyl-heptenes including trans/cis-5-methyl-2-heptene > trans/cis-5-methyl-3-heptene > trans-3-methyl-2-heptene (at the lowest conversion) were the other major products summing to 15.6%. The selectivity of linear octenes decreased from 84 to 78% as the conversion increased from 10% to 29%. The product distribution suggests the reaction pathway involves a head-to-head coupling of two 1-butene molecules to form internal linear octenes. Head-to-tail coupling of two 1-butene molecules or a coupling between 1-butene and 2-butene forms the observed methyl-heptenes. The rate of head-to-head coupling is higher than the rate of head-to-tail or the rate of 1-butene to 2-butene coupling as indicated by the higher selectivity of linear octenes. The activated catalyst contained both Co3O4 and CoO as confirmed by X-ray diffraction (XRD), in situ Raman spectroscopy, and X-ray absorption spectroscopy. The cobalt oxide particle size was estimated to be between 5 and 10 nm by high-resolution transmission electron microscopy and XRD. The Co3O4/CoO ratio decreased with increasing pretreatment temperature. Metallic cobalt, which has a low catalytic activity, formed at 550 °C.

Improvement of the Catalytic Efficiency of Butene Oligomerization Using Alkali Metal Hydroxide-Modified Hierarchical ZSM-5 Catalysts

“…Figure S1 illustrates the typical step of the Reaction scheme in butene oligomerization. According to a previous report [53], oligomerization of light olefins is a cascade reaction. Traditionally, butene derivatives, C 8 (octenes), are produced by dimerization, and C 8 can further react with surplus butene to produce largely hydrocarbons.…”

Ethylene Dimerization and Oligomerization to 1-Butene and Higher Olefins with Chromium-Promoted Cobalt on Carbon Catalyst

“…The 13 wt % cobalt on carbon catalyst was synthesized based on a wetness impregnation method previously described in the literature. , The catalyst is denoted as CoO X /N–C. The chromium-promoted cobalt on carbon catalyst was synthesized as follows: 2.00 g of sieved activated carbon (Norit, Darco MRXm-1721; BET surface area 600–800 m 2 /g; 250–600 μm particle size) was first treated with 1.8 mL of 30% NH 4 OH solution at room temperature.…”

“…The ethylene oligomerization reactions were conducted in a tubular down-flow fixed-bed reactor described elsewhere. , The length of the reactor tube is 30.5 cm long, and the catalyst bed is between 2.07 cm (0.5 g) and 8.29 cm (2.0 g). The temperature is measured by a built-in thermocouple touching the reactor wall at the center of the catalyst bed.…”

“…The gas effluent was analyzed by an online gas chromatograph (GC–FID, Shimadzu) every 0.5 h. The liquid products were gathered from a cold trap and analyzed by a comprehensive two-dimensional gas chromatograph–mass spectrometer (2D GC–MS). The GC operation conditions and the compound standard information can be found elsewhere. , Ethylene conversion, product selectivity, product yield, α-butene distribution, and weight hourly space velocity (WHSV) were calculated on the basis of eqs –. …”

Synthesis of jet fuel range high-density polycycloalkanes with vanillin and cyclohexanone

“…Jet fuel is one of the most demanded transportation fuels. During the past few years, great efforts have been devoted to the synthesis of jet fuel range hydrocarbons by the C–C coupling reactions (such as aldol condensation, 3 hydroxyalkylation/alkylation, 4 alkylation, 5 Michael addition, 6 olefin oligomerization, 7 benzoic condensation, 8 Robinson annulation 9 and photo-catalyzed 2 + 2 cycloaddition 10 ) of lignocellulose derived platform compounds, followed by hydrodeoxygenation (HDO) or hydrogenation. However, most of the reported work was focused on the synthesis of jet fuel with cellulose and hemicellulose derived platform compounds.…”