Cleaner technology for the production of linear long-chain α-olefins through a “millisecond” oxidative cracking process: a positive impact of the reactant carbon chain length

Abstract

The oxidative cracking of n-decane, n-dodecane, n-tetradecane and n-hexadecane was assessed at millisecond contact times on a platinum catalyst at a C/O molar ratio of 1.8. The thermal mapping of the reactor showed the similar thermal behaviour of the millisecond reactor at the steady-state for all reactants, corresponding to the autothermal operation of the combustion catalyst in the range of 440–550 °C. The heat provided led to a thermal gradient in the post-catalytic gas-phase and sustained the endothermic formation of valuable linear α-olefins (LAOs). The LAO yields increased with the carbon chain length of the reactant from 11.4 wt% starting from n-decane to 20.2 wt% starting from n-hexadecane. Furthermore, the LAO carbon chain length tends to be higher when feeding the MSR with larger n-alkanes. Two mathematical models are able to predict the distributions of organic products: (i) the Anderson-Schultz-Flory law for cracking products, i.e. LAO and n-aldehydes and (ii) a model based on the hydrogen atom abstraction probability for oxygenated compounds, the formation of which does not involve carbon–carbon bond cleavage, i.e. tetrahydrofurans, oxiranes and ketones.

---

Introduction

Linear α-olefins are key petrochemical intermediates. The global production was 5 Mt in 2017 and should grow in the following years to reach 6.2 Mt in 2024.¹ The current industrial production involves the steam cracking of hydrocarbons at high temperatures (>750 °C) followed by ethylene oligomerisation.^2,3 This reaction requires high pressures (>10 atm) and is carried out in an organic solvent with homogeneous Ziegler or nickel complex catalysts.^3–5 The chain lengths of LAOs thus extend from 4 to 30 carbon atoms and follow the Schulz–Flory distribution for high-temperature oligomerisation (Gulfene and SHOP processes) or the Poisson distribution for low-temperature oligomerisation (ethyl process).^3,6,7 LAOs then supply the markets of polyethene, surfactants, lubricants and plasticisers.^3,8

The oxidative cracking (OC) of hydrocarbons in a millisecond reactor (MSR) appears as a promising alternative to synthesise these raw materials in one step at atmospheric pressure.^9–13 Hydrocarbons react at millisecond contact times with a heterogeneous combustion catalyst (e.g. Pt/Al₂O₃) to produce LAOs through an autothermal way.^11,14 In this homogeneous process assisted by heterogeneous catalysis, complete and partial catalysed combustion of a part of the reactant provides the required heat for the gas-phase formation of olefins by oxidative and thermal cracking.^{10,11,13,15–19} The MSR is then a 2-zone reaction system involving consideration of both the thermal equilibrium and chemical transformation.

The studies of Schmidt et al. of various reactants highlight the dependence of the chemical nature of the organic products on the reactant structure. Alkanes produce mostly olefins,^{9,11,12,19–21} while cyclic reactants produce aromatics^22–24 and oxygenated reactants result in oxygenated compounds.^25–27 In some studies of diesel n-paraffin OC in a MSR,^10,11 Schmidt et al. showed the relevance of this technology to produce LAOs. They highlight an increase in the length and the yield of LAOs with n-alkane length. Nevertheless, the impact of the reactant carbon chain length on olefin formation and MSR behaviour still requires clarification. It is well established that the reactivity of n-alkanes increases with their carbon chain length when the conversion occurs through gas-phase oxidation,²⁸ catalytic combustion,²⁹ acidic-catalysed reaction^30,31 or thermal cracking.^32–34 In the case of thermal cracking, heavier hydrocarbons lead to higher yields of ethylene. The complex reaction system involved in a MSR with various chemical transformations requires a thorough study of the different reactivities of the diesel n-alkanes.

The MSR is a chemical process combining several reactions leading to products with a wide range of chemical natures.¹⁸ Peroxyalkyl radicals were identified as key intermediates for the formation of organic products from the n-decane OC.¹⁸ Their formation involves a random secondary hydrogen atom abstraction from the n-alkane followed by molecular oxygen addition. The peroxyalkyl radical then undergoes an internal secondary hydrogen atom transfer (HT) to form a hydroperoxyalkyl radical. The nature of the final organic product depends on the hydrogen atom position abstracted during the internal transfer step. A HT on the third carbon atom from the peroxyradical position leads to the formation of an olefin and an n-aldehyde after a β-scission of a C–C bond and a HO˙ elimination; the olefin production occurs mainly from this path and in smaller amounts from the thermal cracking of the n-alkane. A HT occurring on the same position, or on the second or fourth carbon atom from the peroxyradical position, leads respectively to the formation of a ketone, an oxirane or a tetrahydrofuran (THF) after the HO˙ elimination. These three oxygenated compounds are obtained with the same carbon atom number as the reactant. A mathematical model was established¹⁸ to predict the distributions of THF, oxiranes and ketones resulting from the n-decane OC. It is based on the hydrogen atom abstraction probability (HAAP); the distribution is calculated as the sum of the probabilities to abstract the correct secondary hydrogen atom at the two mechanism steps (abstraction from n-alkane and internal transfer), leading to the formation of the considered compound. Each secondary hydrogen atom is considered to have similar reactivity.

This study aims to assess the impact of the carbon chain length of the reactant on the performance of the MSR dedicated to LAO production and the transposition of the model of the organic compound distributions to higher n-alkanes. The thermal mapping of the reactor and the online quantification (through gas-phase chromatography) of products obtained during the oxidative cracking of model molecules, n-decane (n-C₁₀), n-dodecane (n-C₁₂), n-tetradecane (n-C₁₄) and n-hexadecane (n-C₁₆), will allow the characterisation and deep understanding of the thermal and chemical phenomena involved in the MSR. Oxidative cracking will be carried out on new platinum-based catalysts at a C/O molar ratio of 1.8, with a similar heat flow at the reactor inlet for all the studied reactants.

Experimental

Catalyst preparation

Platinum catalysts were prepared by gamma-alumina washcoating of cordierite monoliths followed by impregnation of platinum. The detailed procedure can be found in a previous study.¹⁸ Monoliths (CTI, 15.8 mm diameter, 5 mm length, 600 CPSI) were immersed into a sol composed of boehmite (Dispersal P2, Sasol) and urea (Sigma-Aldrich) in acidified water. The alumina content reached 10 wt% of the washcoated material. The monoliths were then calcinated at 500 °C and impregnated with an aqueous solution containing H₂PtCl₆ (Alfa Aesar) as a precursor salt; its concentration was adjusted to reach 2 wt% of the final washcoated material. New catalysts were obtained after calcination at 500 °C followed by reduction at 800 °C. The BET surface measured by nitrogen sorptiometry using a Micromeritics Tristar 2 device and calculated according to the t-plot method was around 150 m² g⁻¹ washcoat. The platinum particules were close to 1.5 nm and a dispersion of 80% was obtained according to transmission electron microscopy measurements performed using a JEOL 2100 UHR microscope.

Catalytic tests

The experimental setup involving a millisecond reactor, product analysis and experimental procedure was described in detail in a previous study.¹⁸

Millisecond reactor setup

The reactor was a quartz cylinder (16 mm inner diameter, 755 mm length) fed with 2 N L min⁻¹ of air through a mass flow controller. Liquid hydrocarbons were pulverised onto the reactor walls using an automotive injector. A first tubular oven was used to preheat and vaporise the liquid reactants, and mix them homogeneously with air. A second tubular oven was used to ignite the reactions. K-Type thermocouples (1 mm diameter) were inserted in a thermocouple well inside the reactor to record the catalyst temperature, and the post-catalytic gas-phase temperatures at 0, 20, 40, 60, 100, 120, 185 and 235 mm from the catalyst back face. Part of the flow at the reactor outlet was subjected to online gas-phase chromatography (GPC) for mass balance quantification and the other part was cooled down in a condenser for the offline identification of products through GC-MS.

Product quantification online

The products were analysed through online gas-phase chromatography. The device was fitted with a thermal conductivity detector connected to a Hayesep Q (0.25 m × 1/16 in outer diameter (OD), 1 mm internal diameter (ID), 80–100 mesh) packed column followed by a Molsieve 13X (0.25 m × 1/16 in OD, 1 mm ID, 80–100 mesh) packed column to quantify CO, CO₂, N₂, O₂ and H₂. Two flame ionisation detectors were used to quantify hydrocarbons and oxygenated compounds. The products were separated on a capillary precolumn CP-Wax 58 CB (50 m × 0.32 mm, 0.5 μm film thickness) connected to a Rt-Alumina/MAPD (30 m × 0.32 mm, 0.5 μm film thickness) capillary column for lighter hydrocarbons (C₁ to C₅) and a SCION-1MS (30 m × 0.32 mm, 0.5 μm film thickness) capillary column for heavier hydrocarbons. The TCD detector was calibrated with mixtures of compounds diluted in nitrogen. FID detectors were calibrated and the carbon response coefficient was determined using a hydrocarbon cylinder (Air Liquide) containing alkanes and 1-alkenes from C₁ to C₆. The effective carbon number (ECN) concept³⁵ was used to estimate the response coefficients of oxygenated compounds after offline identification through GC-MS.

Product identification offline

Prior to analysis, the condensates were fractionated through distillation at atmospheric pressure and solid-phase extraction (SPE) using a silica cartridge (Bond Elut-SI, 1.5 g, 3 mL, 40 μm, Agilent) eluted with CH₂Cl₂ and then methanol. The products in the fractions were identified using a GC (Agilent 7890A)-MS (Agilent Accurate-mass QTOF 7200) device, fitted with a DB-Wax (40 m × 0.18 mm, 0.30 μm film thickness) capillary column followed by a SCION-1MS (30 m × 0.32 mm, 0.25 μm film thickness) capillary column. The fractions were then analysed with the online GPC to determine the retention times of the identified products.

Experimental procedure

Prior to the catalytic test, the first tubular oven was preheated to 100 °C above the theoretical boiling point of the evaluated n-alkane and the second oven at 420 °C, under a flow of 2 NL min⁻¹ air. Once each temperature was stable, the reactor temperature was recorded, corresponding to the starting of the catalytic test (t = 0 min). After 1 min, the reactor was fed with 14 mg s⁻¹ of the hydrocarbon reactant and 2 NL min⁻¹ of air, which corresponds to a carbon to oxygen (C/O) molar ratio of 1.8. The second tubular oven was shut off at the startup of the process (t = 0 min) and acted as thermal insulation. The reactor pressure, measured by a gauge, did not exceed 112 kPa during the test.

The flow at the outlet of the reactor was analysed through online GPC after 10, 70 and 135 min to quantify the products.

The molar flow of a compound i (F_i in mol min⁻¹) was determined from the calibrations with inert nitrogen as the internal standard:

where A_i and A_N2 are the chromatogram peaks areas, and K_i and K_N2 are the response factors of compounds i and N₂, respectively.

The conversion of n-alkane (X_n–alkane) was determined as follows:

where x_i is the number of carbon atoms in the compound i.

Dioxygen conversion (X_O2) was calculated from the inlet molar flow (F_O2,0) provided by the mass flow controller:

The yield of the hydrocarbon product j (Y_j) was reported on a carbon atom basis as follows:

The oxygen atom balance was closed to calculate the water molar flow rate. Carbon and hydrogen atom balances were typically closed within ± 8%, close to L.D. Schmidt et al.^10,12

Results

The oxidative cracking of n-C₁₀, n-C₁₂, n-C₁₄ and n-C₁₆ was carried out at a C/O molar ratio of 1.8 and at a contact time of 10 ms. The temperature was recorded in the post-catalytic gas-phase with K-type thermocouples. Fig. 1 depicts the evolution of the stream temperature (through a colour scale) alongside the reactor post-catalytic area: from the exit of the monolithic platinum catalyst (D = 0 mm) to 235 mm below, as a function of time on stream (TOS) for the four n-alkanes.

Fig. 1 Temperature evolutions in the post-catalytic gas-phase as a function of time-on-stream and measured at different distances (D) from the catalyst back face during the oxidative cracking of n-decane (n-C₁₀), n-dodecane (n-C₁₂), n-tetradecane (n-C₁₄), and n-hexadecane (n-C₁₆).

The catalyst temperature increases immediately after feeding the reactor with the air–hydrocarbon mixture, which corresponds to a TOS of 1 min. After some minutes, the MSR reaches an autothermal steady-state. The catalyst temperature equilibrates then at 490 to 550 °C for the n-decane and 440 °C for the other n-alkanes. A thermal gradient establishes within the post-catalytic gas-phase during the operation, from the catalyst back face to 235 mm below. The hydrocarbon flow stop results in an exotherm on the catalyst surface and 20 mm below inside the gas phase, followed by the fast cooling of the reactor. The thermal behaviours of the MSR for the four n-alkanes (Fig. 1) are similar to the previous one observed during n-decane oxidative cracking.¹⁸

The yields of carbonaceous products and dioxygen conversion are depicted in Fig. 2 for n-decane, n-dodecane, n-tetradecane and n-hexadecane at TOS of 10, 70 and 135 min. Hydrocarbon conversions, i.e. the sum of yields is close to 50% and the oxygen conversion is higher than 75% for each of the reactants.

Fig. 2 Product yields (bart chart) and oxygen conversion (■) at different times-on-stream (and the related equilibrium catalyst temperature) for n-decane (n-C₁₀), n-dodecane (n-C₁₂), n-tetradecane (n-C₁₄), and n-hexadecane (n-C₁₆) oxidative cracking.

The OC of these n-paraffins produces compounds with similar chemical natures: partial and total oxidation compounds, i.e. CO and CO₂, small amounts of methane (yields ≤ 1.5%) and organic products. Organic products are oxygenated compounds with n-aldehydes, THF, oxiranes, ketones and olefins. Olefins are mainly light olefins, i.e. ethylene and propylene, and α-olefins. Small amounts of positional isomers of the alkene function having the same number of carbon atoms as the reactive n-alkane (yields ≈ 3 wt%) are produced. The typical chromatograms of heavy organic products obtained during the four n-alkanes OC are depicted in the ESI† in Fig. S1. The increase of the carbon chain length of the reactant induces a broadening of the number of compounds in these organic product families. Heavier α-olefins and n-aldehydes are produced, and their formation involves C–C bond cracking.¹⁸ The number of position isomers increases for THF, oxiranes, ketones and olefins with the same carbon atom number as the parent n-alkane. They result from peroxy radical decomposition.

Yields and distributions of olefins

The left panel of Fig. 3 depicts the yields of olefins obtained from the OC of the four n-alkanes during the stationary state of the MSR.

Fig. 3 Bar chart (left panel) of the yields of α-olefins (solid bars) and double bond isomers from the parent n-alkane as a function of the carbon chain length (n_Carbons) obtained at times-on-stream of 70 and 135 min. Pseudo-Anderson-Schulz-Flory plots (right panel) at a time-on-stream of 135 min for n-decane (n-C₁₀), n-dodecane (n-C₁₂), n-tetradecane (n-C₁₄), and n-hexadecane (n-C₁₆) oxidative cracking.

Their size range extends from ethylene to olefins having the same number of carbon atoms as the evaluated n-alkane.

The yields show the same asymmetrical appearance, with a more significant amount of light olefins (ethylene and propylene) than that of LAOs. In the case of LAOs, the yield profiles flatten out with the increase in the size of the carbon chain of the reactant, and then the production of LAOs tends towards equimass formation.

The Anderson-Schultz-Flory (ASF) law^5,6 allows modelling the evolution of the molar distributions of LAOs resulting from cracking according to the following equation:

where is the molar distribution of a LAO and x is its number of carbons.

The ASF law is usually used to describe the distribution of LAOs synthesised from chain growing processes such as ethylene oligomerisation^5,6 or Fisher–Tropsh.³⁶ It reports competition between twin reactions: propagation of the chain growth and termination of the polymerisation process. The term α in eqn (5) corresponds to the probability of chain growth, defined as the ratio of the rate of the propagation reaction (k_p) and the sum of the rates of the propagation and termination reactions (k_t):

where the α parameter allows the distribution of a LAO to be described: the closer its value is to 1, the more balanced the size distribution of the LAO is.^5,6

In the MSR process, the LAO results from chain cleavage; by analogy with these chain-growth processes, the term α can transcribe a possible over-cracking. A low value of α corresponds to the most light olefin formation, i.e. significant over-cracking by homolytic cleavage or β-scission of C–C bonds. A value close to 1 corresponds to a balanced distribution, i.e. stabilization of terminal alkyl radicals by β-scission of a C–H bond and preservation of olefins formed from possible over-cracking reactions, such as new initiations by the homolytic cleavage of C–C bonds.

The ASF plots of LAO resulting from OC of n-C₁₀, n-C₁₂, n-C₁₄ and n-C₁₆ are depicted in Fig. 3. The size distributions of LAO consecutive from breaking a bond between two secondary carbon atoms follow the ASF law (Fig. 3). The olefin with one carbon atom less than the reactive n-alkane involves a different first stage of formation, corresponding to the cleavage of a bond between the primary and secondary carbon atoms. Therefore, the ASF law cannot be used to model their molar distributions. Ethylene and propylene formation do not involve the competition step between over-cracking and stabilization. Likewise, light olefin molar distributions are not described by the ASF law.

Yields and distributions of oxygenated compounds

The oxygenated compounds are sorted into two categories, depending on whether their formation involves carbon–carbon bond breaking (n-aldehydes) or preserves the carbon backbone (THFs, oxiranes and ketones).¹⁸

Yields and distributions of n-aldehydes

The yields of n-aldehydes resulting from the OC of the four n-paraffins are depicted in Fig. 4. The size range of these products extends from ethanol to n-aldehyde, having two carbon atoms less than the parent n-alkane. The yields exhibit the same trend as olefins (Fig. 3), with a higher production of light aldehydes.

Fig. 4 Bar chart (left panel) of the yields of n-aldehydes and plots of the hydrogen atom abstraction probability model at a time-on-stream of 135 min. Pseudo-Anderson-Schulz-Flory plots (right panel) at a time-on-stream of 135 min for n-decane (n-C₁₀), n-dodecane (n-C₁₂), n-tetradecane (n-C₁₄), and n-hexadecane (n-C₁₆) oxidative cracking.

Two models were considered to fit the molar distributions of n-aldehydes: (1) the HAAP model¹⁸ and (2) the ASF law. The plots are depicted respectively in the left panel and the right panel of Fig. 4. As observed in a previous study about n-C₁₀ oxidative cracking,¹⁸ the HAAP model does not fit the n-aldehyde distributions. The ASF law previously used to model olefin distributions suitably fits n-aldehyde distributions.

Yields and distributions of THFs, oxiranes and ketones

The OC of n-decane, n-dodecane, n-tetradecane and n-hexadecane leads to the formation of oxygenated compounds having the same nature: tetrahydrofurans, epoxides and ketones (Fig. 5). They result from the addition of molecular oxygen followed by the decomposition of the peroxyalkyl radical^18,37 and have the same number of carbon atoms as the parent n-paraffin. All the positions of the oxygenated functions are observed. Therefore, the number of compounds in each of these families increases with the size of the reactant carbon chain (one isomer per increment of two carbon atoms). The OC of higher n-alkanes leads to THF as the main oxygenated product (Fig. 5) as for the pure gas-phase oxidation of n-C₁₀ and n-C₁₆.^37,38 The HAAP model fits well the distributions of THFS, oxiranes and ketones (Fig. 5). Therefore, the addition of molecular oxygen to secondary carbon atoms occurs randomly.

Fig. 5 Bar charts of the yields of tetrahydrofurans (left panel), oxiranes (middle panel) and ketones (right panel) and plots of the hydrogen atom abstraction probability model at a time-on-stream of 135 min for n-decane (n-C₁₀), n-dodecane (n-C₁₂), n-tetradecane (n-C₁₄), and n-hexadecane (n-C₁₆) oxidative cracking.

Discussion

The equilibrium temperatures of the catalyst reach similar values at a TOS of 135 min: 440 °C for n-C₁₂, n-C₁₄ and n-C₁₆ and 490 °C for n-C₁₀ (Fig. 6). For the four n-alkanes, the gas phase temperature from 0 to 235 mm at the catalyst outlet is above the autoignition point of the n-paraffin³⁹ (Fig. 1). The thermal behaviour of the MSR depicts a 2-zone reaction system with the catalyst as an energy provider (the hottest point of the reactor) and the gas phase as a homogeneous oxidation area.

Fig. 6 Conversions of n-alkane and molecular oxygen and equilibrium catalyst temperature at a time on stream of 135 min as a function of the carbon number of the reactive n-alkane.

The homogeneous area is larger than the heterogeneous one (several tens of millimeters and 10 mm respectively for the gas phase and the catalyst). Furthermore, the length of the homogeneous reaction area is not constant and decreases with TOS, as depicted in Fig. 1 by the post-catalytic gas-phase temperature bottom-up cooling down (235 mm). This characterization of the MSR thermal behaviour is consistent with L. D. Schmidt's observations.^13,17 At a TOS of 135 min, the MSR reaches its steady-state, and the conversions of n-alkanes increase with their carbon chain length, while dioxygen conversion remains constant (Fig. 6). Therefore, the yields of partial and total combustion products (Fig. 7A) and oxygenated products (Fig. 7B) are similar. The increase of the carbon chain length of the reactant allows extending the production of LAO without the effect on light olefins and olefins having the same number of carbon atoms as the parent n-paraffin (Fig. 7C).

Fig. 7 Yields of combustion products (A), oxygenated compounds (B) and olefins (C) at a time on stream of 135 min as a function of the carbon number of the reactive n-alkane.

The n-alkane transformation through OC in a MSR involves different paths of transformation¹⁸ among the catalytic partial and total combustion, the homogeneous cracking implying molecular oxygen and the thermal cracking of the carbon chain. Olefin production can come with oxygenated compound formation (molecular oxygen implication, i.e. the peroxyalkyl pathway) or without the formation of side-products (thermal cracking, i.e. the pyrolytic pathway). In the present study, the reactivity of n-alkanes increases with their carbon chain length regarding thermal cracking and results in higher yields of LAOs.

The constant yields of olefins having the same number of carbon atoms as the reactive n-alkane (Fig. 7C) depict that the increase of initiated n-alkane occurs mainly through C–C bond cleavage (i.e. intramolecular initiation), rather than H˙ abstraction (i.e. intermolecular initiation). It agrees with the carbon–carbon bond energy decreasing with the length of the n-paraffin chain.⁴⁰

The Anderson-Schulz-Flory parameters increase with the number of carbon atoms of the reagent concerning LAO and n-aldehyde distributions (Fig. 8).

Fig. 8 Anderson-Schultz-Flory parameters from the α-olefin and n-aldehyde distribution modelisation at a time on stream of 135 min as a function of the carbon number of the reactive n-alkane.

It depicts a flattening of the size distributions of cracking products and thus a formation with longer linear carbon chains. Thus, the MSR operation conditions preserve the length of the chains of terminal alkyl radicals coming from the random cleavage of the carbon chain of n-alkanes. The stable formation of light olefins (ethylene and propylene) indicates that C–H cleavage reactions predominate over C–C β-cleavage for terminal alkyl radical transformation.

In addition, the absence of di-olefinic compounds (such as 1,3-butadiene) highlights the absence of over-cracking reactions through new intramolecular initiations.

Conclusion

The oxidative cracking of n-decane, n-dodecane, n-tetradecane and n-hexadecane through a MSR was evaluated at steady-state temperatures between 440 °C and 490 °C at a C/O molar ratio of 1.8. The first stages of the radical mechanism involve mainly molecular oxygen and hydrogen atoms from the hydrocarbon reagent. The initiation of n-alkane occurs statistically on all secondary carbon atoms in the chain through an equiprobable hydrogen atom abstraction. Therefore, the number of products having the same chemical nature increases with the lengthening of the n-alkane carbon chain. The sizes of the cracking products as linear α-olefins and n-aldehydes widen, and all the position isomers of products with the same carbon atom number as the reagent, THFs, oxiranes, ketones and olefins, are formed. Two mathematical models allow fitting the distributions of organic products through: (i) the Anderson-Schultz-Flory law for LAOs and n-aldehydes and (ii) a model based on the hydrogen atom abstraction probability for tetrahydrofurans, oxiranes and ketones.

The reactivity of n-alkanes increases with their length due to a significant initiation by breaking of carbon–carbon bonds. Consequently, the yields of LAOs increase, while the oxygenated compounds and total and partial combustion products are formed in similar proportions. The experimental conditions of the MSR, i.e. temperature and residence time, preserve these primary products from secondary transformations, such as over-cracking or oxidation. Likewise, the probability of stabilizing a terminal alkyl radical into a linear α-olefin through β-scission of a C–H bond is more significant than successive ethylene elimination through β-scission of a C–C bond. Higher carbon chain n-paraffins allow longer linear α-olefin production by fast stabilization of the cracking fragments.

Author contributions

H. Cruchade: formal analysis, investigation methodology, and writing – original draft; Y. Pouilloux: supervision; R. Beauchet: supervision; and L. Pinard: conceptualisation, supervision, and writing – review and editing.

Conflicts of interest

There are no conflicts to declare.

Acknowledgements

The authors acknowledge financial support from the European Union (ERDF) and the “Région Nouvelle Aquitaine”. Hugo Cruchade acknowledges the “Ministère de ľenseignement supérieur, de la recherche et de ľinnovation” for the PhD grant.

References

1. Alpha Olefin Market Size & Share | Global Industry Report, 2019–2025, https://www.grandviewresearch.com/industry-analysis/alpha-olefins-market, (accessed November 4, 2021).
2. T. Ren, M. Patel and K. Blok, Energy, 2006, 31, 425–451.
3. G. R. Lappin, L. H. Nemec, J. D. Sauer and J. D. Wagner, Kirk-Othmer Encyclopedia of Chemical Technology, American Cancer Society, 2010, pp. 1–20.
4. J. Skupinska, Chem. Rev., 1991, 91, 613–648.
5. O. L. Sydora, Organometallics, 2019, 38, 997–1010.
6. C. T. Young, R. von Goetze, A. K. Tomov, F. Zaccaria and G. J. P. Britovsek, Top. Catal., 2020, 63, 294–318.
7. W. Keim, Angew. Chem., Int. Ed., 2013, 52, 12492–12496.
8. A. Forestière, H. Olivier-Bourbigou and L. Saussine, Oil Gas Sci. Technol. - Rev. IFP, 2009, 64, 649–667.
9. N. J. Degenstein, R. Subramanian and L. D. Schmidt, Appl. Catal., A, 2006, 305, 146–159.
10. J. J. Krummenacher, K. N. West and L. D. Schmidt, J. Catal., 2003, 215, 332–343.
11. J. J. Krummenacher and L. D. Schmidt, J. Catal., 2004, 222, 429–438.
12. G. J. Panuccio, B. J. Dreyer and L. D. Schmidt, AIChE J., 2007, 53, 187–195.
13. G. J. Panuccio, K. A. Williams and L. D. Schmidt, Chem. Eng. Sci., 2006, 61, 4207–4219.
14. L. D. Schmidt, M. Huff and S. S. Bharadwaj, Chem. Eng. Sci., 1994, 49, 3981–3994.
15. R. Horn, N. J. Degenstein, K. A. Williams and L. D. Schmidt, Catal. Lett., 2006, 110, 169–178.
16. B. C. Michael, D. N. Nare and L. D. Schmidt, Chem. Eng. Sci., 2010, 65, 3893–3902.
17. D. A. Henning and L. D. Schmidt, Chem. Eng. Sci., 2002, 57, 2615–2625.
18. H. Cruchade, C. Veit, J.-J. Colin, R. Beauchet, Y. Batonneau, Y. Pouilloux, B. Leroux and L. Pinard, Appl. Catal., A, 2021, 610, 117944.
19. R. Subramanian, G. J. Panuccio, J. J. Krummenacher, I. C. Lee and L. D. Schmidt, Chem. Eng. Sci., 2004, 59, 5501–5507.
20. G. J. Panuccio and L. D. Schmidt, Appl. Catal., A, 2006, 313, 63–73.
21. A. G. Dietz, A. F. Carlsson and L. D. Schmidt, J. Catal., 1998, 176, 459–473.
22. R. P. O’Connor and L. D. Schmidt, J. Catal., 2000, 191, 245–256.
23. R. P. O’Connor, E. J. Klein, D. Henning and L. D. Schmidt, Appl. Catal., A, 2003, 238, 29–40.
24. C. M. Balonek, J. L. Colby and L. D. Schmidt, AIChE J., 2010, 56, 979–988.
25. R. Subramanian and L. D. Schmidt, Angew. Chem., Int. Ed., 2005, 44, 302–305.
26. D. C. Rennard, J. S. Kruger and L. D. Schmidt, ChemSusChem, 2009, 2, 89–98.
27. E. C. Wanat, B. Suman and L. D. Schmidt, J. Catal., 2005, 235, 18–27.
28. J. Biet, M. H. Hakka, V. Warth, P.-A. Glaude and F. Battin-Leclerc, Energy Fuels, 2008, 22, 2258–2269.
29. Y.-F. Y. Yao, Ind. Eng. Chem. Prod. Res. Dev., 1980, 19, 293–298.
30. J. Abbot and P. R. Dunstan, Ind. Eng. Chem. Res., 1997, 36, 76–82.
31. C. Marcilly, Acido-basic Catalysis: Application to Refining and Petrochemistry, Editions Technip, 2005.
32. P. Zámostný, Z. Bělohlav, L. Starkbaumová and J. Patera, J. Anal. Appl. Pyrolysis, 2010, 87, 207–216.
33. J. G. Speight, in Natural and Laboratory-Simulated Thermal Geochemical Processes, ed. R. Ikan, Springer, Netherlands, Dordrecht, 2003, pp. 31–52.
34. M. Watanabe, T. Adschiri and K. Arai, Ind. Eng. Chem. Res., 2001, 40, 2027–2036.
35. J. T. Scanlon and D. E. Willis, J. Chromatogr. Sci., 1985, 23, 333–340.
36. M. Claeys and E. van Steen, in Studies in Surface Science and Catalysis, ed. A. Steynberg and M. Dry, Elsevier, 2004, vol. 152, pp. 601–680.
37. P. Dagaut, M. Reuillon, M. Cathonnet and D. Voisin, J. Chim. Phys., 1995, 92, 47–76.
38. P. Dagaut, M. Reuillon and M. Cathonnet, Combust. Sci. Technol., 1994, 103, 349–359.
39. C. L. Yaws, Yaws’ handbook of thermodynamic and physical properties of chemical compounds: physical, thermodynamic and transport properties for 5,000 organic chemical compounds, Norwich, N.Y., McGraw-Hill, 2003.
40. S. W. Benson, J. Chem. Educ., 1965, 42, 502.

---

Footnote

† Electronic supplementary information (ESI) available. See DOI: 10.1039/d1nj05910f

---