An experimental and modeling study of 2-methyl-1-butanol oxidation in a jet-stirred reactor

International audienc

The Combustion of Synthetic Jet Fuels (Gas to Liquid and Coal to Liquid) and Multi-Component Surrogates: Experimental and Modeling Study

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Decomposition studies of isopropanol in a variable pressure flow reactor

Journal articleAlternatives to traditional petroleum derived transportation fuels, particularly alcohols, have been investigated increasingly over the last 5 years. Isopropanol has received little attention despite bridging the gap between smaller alcohols (methanol and ethanol) and the next generation alcohols (butyl alcohols) to be used in transportation fuels. Previous studies have shown that decomposition reactions that dehydrate are important in the high-temperature oxidation of alcohols. Here we report new data on the dehydration reaction for isopropanol (iC(3)H(7)OH -> C3H6 + H2O) in a Variable Pressure Flow Reactor at 12.5 atm pressure and temperatures from 976-1000 K. Pyrolysis experiments are performed in the presence of a radical trapper (1,3,5 trimethyl benzene or toluene) to inhibit secondary reactions of radicals with the fuel and product species. The recommended rate constant for the dehydration reaction is determined using an indirect method along with Latin Hypercube sampling to estimate uncertainties. Comparison of the rate constant data to previous works show that the reaction is considerably more rapid than the high level theoretical predictions of Bui et al. (Bui et al., J. Chem. Phys., 2002). The dehydration reaction rate for isopropanol is well described by k = 8.52 x 10(6)T(2.12) exp(-30, 667/T) with an estimated uncertainty of sigma(2)(lnA) = 0.0195.The C-C bond fission reaction is also investigated, but the insensitivity of the decomposition data to this reaction results in an uncertainty in the determined rate constants to approximately 2 orders of magnitude. Theoretical estimates lie within these experimental uncertainties.U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences - Award Number DE-SC0001198

A JET-STIRRED REACTOR STUDY OF THE OXIDATION AND PYROLYSIS OF DI-N-PROPYL-ETHER

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Decomposition Studies of Isopropanol in a Variable Pressure Flow Reactor

Alternatives to traditional petroleum derived transportation fuels, particularly alcohols, have been investigated increasingly over the last 5 years. Isopropanol has received little attention despite bridging the gap between smaller alcohols (methanol and ethanol) and the next generation alcohols (butyl alcohols) to be used in transportation fuels. Previous studies have shown that decomposition reactions that dehydrate are important in the high-temperature oxidation of alcohols. Here we report new data on the dehydration reaction for isopropanol (iC3H7OH → C3H6 + H2O) in a Variable Pressure Flow Reactor at 12.5 atm pressure and temperatures from 976–1000 K. Pyrolysis experiments are performed in the presence of a radical trapper (1,3,5 trimethyl benzene or toluene) to inhibit secondary reactions of radicals with the fuel and product species. The recommended rate constant for the dehydration reaction is determined using an indirect method along with Latin Hypercube sampling to estimate uncertainties. Comparison of the rate constant data to previous works show that the reaction is considerably more rapid than the high level theoretical predictions of Bui et al. (Bui et al., J. Chem. Phys., 2002). The dehydration reaction rate for isopropanol is well described by k = 8.52 × 106T2.12 exp (− 30, 667/T) with an estimated uncertainty of σ  ln  A2 = 0.0195. The C–C bond fission reaction is also investigated, but the insensitivity of the decomposition data to this reaction results in an uncertainty in the determined rate constants to approximately 2 orders of magnitude. Theoretical estimates lie within these experimental uncertainties

Comparative study of the high‐temperature auto‐ignition of cyclopentane and tetrahydrofuran

International audienceAbstract Cyclopentane (C 5 H 10 ) and tetrahydrofuran (C 4 H 8 O) are both five‐membered ring compounds. The present study compares the auto‐ignition of cyclopentane and tetrahydrofuran in a high‐pressure shock‐tube (20 atm). Twelve different mixtures were investigated at two different fuel initial mole fractions (1% and 2%): at X fuel = 1%, three equivalence ratios, kept constant between cyclopentane and tetrahydrofuran, were studied (0.5, 1, and 2), whereas three X fuel /X O2 were investigated when X fuel = 2%. A detailed kinetic mechanism was developed to reproduce cyclopentane and tetrahydrofuran auto‐ignition. The agreement between our experimental results and the modeling is very good. This mechanism was used to explain the similarities and differences observed between cyclopentane and tetrahydrofuran auto‐ignition

Computational Kinetic Study for the Unimolecular Decomposition Pathways of Cyclohexanone

There has been evidence lately that several endophytic fungi can convert lignocellulosic biomass into ketones among other oxygenated compounds. Such compounds could prove useful as biofuels for internal combustion engines. Therefore, their combustion properties are of high interest. Cyclohexanone was identified as an interesting second-generation biofuel (Boot, M.; et al. Cyclic Oxygenates: A New Class of Second-Generation Biofuels for Diesel Engines? Energy Fuels 2009, 23, 1808−1817; Klein-Douwel, R. J. H.; et al. Soot and Chemiluminescence in Diesel Combustion of Bio-Derived, Oxygenated and Reference Fuels. Proc. Combust. Inst. 2009, 32, 2817–2825). However, until recently (Serinyel, Z.; et al. Kinetics of Oxidation of Cyclohexanone in a Jet- Stirred Reactor: Experimental and Modeling. Proc. Combust. Inst. 2014; DOI: 10.1016/j.proci.2014.06.150), no previous studies on the kinetics of oxidation of that fuel could be found in the literature. In this work, we present the first theoretical kinetic study of the unimolecular decomposition pathways of cyclohexanone, a cyclic ketone that could demonstrate important fuel potential. Using the quantum composite G3B3 method, we identified six different decomposition pathways for cyclohexanone and computed the corresponding rate constants. The rate constants were calculated using the G3B3 method coupled with Rice–Ramsperger–Kassel–Marcus theory in the temperature range of 800–2000 K. Our calculations show that the kinetically more favorable channel for thermal decomposition is pathway 2 that produces 1,3-butadien-2-ol, which in turn can isomerize easily to methyl vinyl ketone through a small barrier. The results presented here can be used in a future kinetic combustion mechanism

Experimental and numerical kinetic study of the oxidation of C5H10O2 esters isomers

International audienc

Decomposition Studies of Isopropanol in a Variable Pressure Flow Reactor

Alternatives to traditional petroleum derived transportation fuels, particularly alcohols, have been investigated increasingly over the last 5 years. Isopropanol has received little attention despite bridging the gap between smaller alcohols (methanol and ethanol) and the next generation alcohols (butyl alcohols) to be used in transportation fuels. Previous studies have shown that decomposition reactions that dehydrate are important in the high-temperature oxidation of alcohols. Here we report new data on the dehydration reaction for isopropanol (iC3H7OH → C3H6 + H2O) in a Variable Pressure Flow Reactor at 12.5 atm pressure and temperatures from 976–1000 K. Pyrolysis experiments are performed in the presence of a radical trapper (1,3,5 trimethyl benzene or toluene) to inhibit secondary reactions of radicals with the fuel and product species. The recommended rate constant for the dehydration reaction is determined using an indirect method along with Latin Hypercube sampling to estimate uncertainties. Comparison of the rate constant data to previous works show that the reaction is considerably more rapid than the high level theoretical predictions of Bui et al. (Bui et al., J. Chem. Phys., 2002). The dehydration reaction rate for isopropanol is well described by k = 8.52 × 106T2.12 exp (− 30, 667/T) with an estimated uncertainty of σ  ln  A2 = 0.0195. The C–C bond fission reaction is also investigated, but the insensitivity of the decomposition data to this reaction results in an uncertainty in the determined rate constants to approximately 2 orders of magnitude. Theoretical estimates lie within these experimental uncertainties

A comparative high-pressure jet-stirred reactor study on the oxidation of pentanol isomers: 1-, 2- and 3- pentanol

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