Oxidative reforming of n-heptane in gliding arc plasma reformer for hydrogen production

The exploration of novel technologies to reduce the air pollution and greenhouse gas emissions has been of great interest. Gliding arc plasma reformer at atmospheric pressure has been developed for converting n-heptane to hydrogen. The system has been evaluated by H₂ yield and energy yield via continuous n-heptane oxidative reforming at room temperature. Effects of some process parameters (discharge gap, input power, residence time, and O/C) have been studied on the reaction performance. The maximum H₂ yield and energy yield are 50.1% and 94.5 L (kW h)⁻¹. To investigate the role of inert gas (N₂, Ar) in the plasma oxidative reforming system, the performance of C₇H₁₆/air, C₇H₁₆/N₂/O₂/Ar and C₇H₁₆/O₂/Ar have been investigated. The results show that N₂ (B³Π_g) and Ar¹ can accelerate the formation of active oxygen species (such as O⁺, O (¹D) and O). The presence of active oxygen species promotes the progress of the oxidative reforming reaction. What's more, N₂ (B³Π_g) is also conducive to the direct conversion of n-heptane. The reaction mechanism of hydrogen production from gliding arc plasma oxidative reforming of n-heptane was proposed based on the analysis of the OES and GC–MS.     

Vibrational nonequilibrium and reaction heat effect in diluted hydrogen-oxygen mixtures behind reflected shock waves at 1000 < T < 1300 K

Vibrationally nonequilibrium model of kinetics in the reacting mixture H₂ + O₂ + Ar behind the reflected shock wave is formulated as a non-isothermal process occurring adiabatically at a constant volume. The model takes into account the vibrational nonequilibrium for the starting (primary) H₂ and O₂ molecules, as well as the molecular intermediates HO₂, OH, O₂(¹Δ), and the main reaction product H₂O. Calculation results that simulate experimental data on the ignition induction time measurements in the hydrogen oxygen mixtures behind reflected shock waves by the methods of absorption spectroscopy (monitoring the OH(²Π) radical) and emission spectroscopy (monitoring the OH*(²Σ⁺) radical) at temperatures of 1000 < T < 1300 K and pressures p < 3 atm are compared with experimental data and analyzed. It has been shown that the vibrational nonequilibrium determines the mechanism and rate of the process as a whole. The self-heating effect in diluted reacting mixtures at concentrations of the reacting additive ≤5% is demonstrated and discussed.     

Investigation of hydrogen storage on Sc/Ti-decorated novel B24N24

Inspired by the TM−N₄ coordination environment in single-atom catalysts, four novel TM-decorated B₂₄N₂₄ (TM = Sc, Ti) fullerenes with six TM−N₄ or TM−B₄ units are designed. Molecular dynamic simulations confirm that the four TM₆B₂₄N₂₄ fullerenes are thermodynamically stable. Their hydrogen storage properties were investigated using density functional theory calculations. Sc/Ti atoms bind to the N₄/B₄ cavities with an average interaction energy of 6.30–11.96 eV. Hence, the problem of clustering can be avoided. 36H₂ could be adsorbed with average hydrogen adsorption energies of 0.18–0.55 eV. The lowest hydrogen desorption temperatures at atmospheric pressure for Sc₆B₂₄N₂₄(N₄)–36H₂, Sc₆B₂₄N₂₄(B₄)–36H₂, Ti₆B₂₄N₂₄(N₄)–36H₂, and Ti₆B₂₄N₂₄(B₄)–36H₂ are 255 K, 318 K, 243 K, and 408 K, respectively. The maximum hydrogen gravimetric densities of the Sc₆B₂₄N₂₄ and Ti₆B₂₄N₂₄ systems are 7.74 wt% and 7.50 wt%, respectively. Therefore, the novel Sc₆B₂₄N₂₄ and Ti₆B₂₄N₂₄ could be suitable as potential hydrogen storage materials at ambient temperature.     

Synthesis,structural characterization and thermal decomposition studies of (N2H5)2B12H12 and its solvates

A series of salts of the B₁₂H₁₂²⁻ anion has been prepared: a solvent-free (N₂H₅)₂B₁₂H₁₂, its solvates – (N₂H₅)₂B₁₂H₁₂·H₂O, (N₂H₅)₂B₁₂H₁₂·2(CH₃CN), (N₂H₅)₂B₁₂H₁₂·(CH₃OH), and the salt of a protonated azine – [(CH₃)₂CNNHC(CH₃)₂]₂B₁₂H₁₂. These compounds have been synthesized from the commercially available precursors via one- or two-step procedures and fully identified on the basis of single-crystal and powder X-ray diffraction. At room temperature (N₂H₅)₂B₁₂H₁₂ crystallizes in C2/c space group, with a = 18.480(5) Å, b = 6.5344(19) Å, c = 13.106(4) Å and β = 131.911(16)^o, V = 1177.8(7) ų, Z = 4. While this compound nominally contains ca. 10.7 wt% of hydrogen, it thermally decomposes above 200 °C releasing mainly N₂ and NH₃, with H₂ being only the minor gaseous product. Contrary to the recently reported case of hydrazinates of borohydrides, doping with 5 mol% of FeCl₃ does not increase the relative amount of hydrogen significantly, however, it alters the ratio of N₂ and NH₃.     

Hydrogen production by steam-oxidative reforming of bio-ethanol assisted by Laval nozzle arc discharge

The hydrogen production from an easily transported liquid feedstock can be an efficient alternative for fuel cells application. The steam-oxidative reforming of bio-ethanol by a novel gliding arc discharge named Laval nozzle arc discharge (LNAD) was investigated in this paper at low temperature and atmospheric pressure. The conversion efficiency and product distributions, mainly of H₂ and CO, were studied as functions of O/C ratio, S/C ratio, the ethanol flow rate and input power. The voltage–ampere (V–I) characteristic is also discussed here concerning the non-thermal plasma effect on the bio-ethanol reforming. A high conversion rate and fair H₂ yield have been achieved, 90% and 40% respectively. When the ethanol flow rate (G_ethanol) was 0.15 g s⁻¹ and S/C = 2.0, the minimum specific energy requirement of H₂ and CO were achieved at O/C = 1.4 with the specific energy input of 55.44 kJ per ethanol mole, 72.92 kJ mol⁻¹ and 80.20 kJ mol⁻¹ respectively. The optimal conditions for ethanol reforming seem to be S/C = 2.0 and O/C = 1.4–1.6, which are higher than those of the reaction's stoichiometry. This paper shows interesting results in comparison with the ethanol reforming assisted by other discharges. Compared with others, it features good conversion rate, low energy consumption and significantly reduced nitrogen oxide emission.     

CeO2–ZrO2-promoted CuO/ZnO catalyst for methanol steam reforming

The Cu-based catalysts with different supports (CeO₂, ZrO₂ and CeO₂–ZrO₂) for methanol steam reforming (MSR) were prepared by a co-precipitation procedure, and the effect of different supports was investigated. The catalysts were characterized by means of N₂ adsorption–desorption, X-ray diffraction, temperature-programmed reduction, oxygen storage capacity and N₂O titration. The results showed that the Cu dispersion, reducibility of catalysts and oxygen storage capacity evidently influenced the catalytic activity and CO selectivity. The introduction of ZrO₂ into the catalyst improved the Cu dispersion and catalyst reducibility, while the addition of CeO₂ mainly increased oxygen storage capacity. It was noticed that the CeO₂–ZrO₂-containing catalyst showed the best performance with lower CO concentration, which was due to the high Cu dispersion and well oxygen storage capacity. Further investigation illuminated that the formation of CO on CuO/ZnO/CeO₂–ZrO₂ catalyst mainly due to the reverse water gas shift. In addition, the CuO/ZnO/CeO₂–ZrO₂ catalyst also had excellent reforming performance with no deactivation during 360 h run time and was used successfully in a mini reformer. The maximum hydrogen production rate in the mini reformer reached to 162.8 dm³/h, which can produce 160–270 W electric energy power by different kinds of fuel cells.     

Carbon nanotubes and hydrogen production from the reforming of toluene

Catalytic steam reforming of liquid hydrocarbons is one of the promising alternatives for hydrogen production. However, coke deposition on the reacted catalyst results in catalyst deactivation and also CO₂ emission during reforming are among the main challenges in the process. In this work, the production of high-value carbon nanotubes (CNTs) during hydrogen production from catalytic reforming of toluene has been investigated. Thus, less carbon emission and higher product values can be expected from the process. A two-stage fixed bed pyrolysis-reforming reactor was used in this work. The results showed that the addition of a Ni–Mg–Al catalyst, with an additional downstream stainless steel mesh, increased hydrogen production from 24.8 to 54.8 (mmol H₂ g⁻¹ toluene), when water (steam) was injected at a rate of 0.01 g min⁻¹. CNTs were also produced in the process in the presence of the Ni–Mg–Al catalyst and with a water injection rate of 0.01 g min⁻¹ had the highest band ratio of G′/G when analyzed by Raman spectrometry, indicating the highest purity of CNTs. In addition, Raman spectra of the generated CNTs showed that the purity of CNTs was reduced with the addition of water for reforming without the Ni–Mg–Al catalyst. The presence of the Ni–Mg–Al catalyst significantly increased the yield of CNTs formed on the surface of the stainless steel mesh and also improved the quality of the CNTs in relation to the distribution of diameters and their length.     

Metal-free hybrid composite particles with phosphorus and oxygen-doped graphitic carbon nitride dispersed on kaolin for catalytic activity toward efficient hydrogen release

Here, hybrid kaolin-g-C₃N₄ heterostructure particles were fabricated by calcination in the first step, followed by hydrothermal phosphoric acid activation in the second step, and phosphorus (P) and oxygen (O) doped kaolin-g-C₃N₄ metal-free catalyst was synthesized. This hybrid metal-free catalyst was used for the first time for the production of effective hydrogen (H₂) from sodium borohydride (NaBH₄) methanolysis. The hydrogen generation rate (HGR) value of 5500 ml min⁻¹g⁻¹ was obtained with the P and O doped kaolin-g-C₃N₄ catalyst. The activation energy (Ea) of 31.90 kJ mol⁻¹ by P and O doped kaolin-g-C₃N₄ for the production of H₂ was obtained. The kaolin-g-C₃N₄ and P and O doped kaolin-g-C₃N₄ metal-free catalysts were systematically characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR). Based on the results obtained, the mechanism of P and O-doped kaolin-g-C₃N₄ catalyst on H₂ production from NaBH₄ methanolysis was also proposed.     

Renewable hydrogen from ethanol by a miniaturized nonthermal arc plasma-catalytic reforming system

Ethanol–water mixtures were reformed directly into H₂-rich gas without extra heat source with conversion rates of 69.8% and 88.0% by nonthermal arc plasma and plasma-catalytic reactors, respectively. The plasma reactor consists of a Laval nozzle electrode and a central electrode. The ethanol, water and air mixtures were mixed by a spray nozzle, and then introduced into the Laval nozzle. In terms of energy efficiency, the optimal reforming condition was determined to be O/C ∼ 0.5 and S/C ∼ 1.0 with an ethanol input rate of ∼0.10 g s⁻¹. Furthermore, it is also found that applying Ni/γ-Al₂O₃ catalyst just at the downstream of the discharge region contributed to a better conversion extent and a higher hydrogen production rate, while the power consumption increased slightly, thus the specific energy required for hydrogen production reduced from 68.5 to 40.1 kJ mol⁻¹ at O/C = 0.44, S/C = 1.28 and inlet ethanol = 0.10 g s⁻¹. This reforming technology has promising prospects not only for low-cost hydrogen generation and efficiency improvement for inner combustion engine, but also for many other potential chemical applications, such as nanophase material preparation and solar fuel cell manufacturing.     

Microwave plasma torches driven by surface wave applied for hydrogen production

A microwave (2.45 GHz) Ar plasma torch at atmospheric pressure has been applied for hydrogen production from the decomposition of alcohols (methanol and ethanol). The hydrogen yield dependence on the gas fluxes and the microwave input power has been investigated both in Ar and Ar + water plasma environments. Mass and FTIR spectroscopy have been used to detect the molecular hydrogen produced and the H₂O, CO₂ and CO molecules in the exhaust gas stream. Nearly 100% decomposition of methanol molecules was achieved in the Ar plasma torch. It was further found that the H₂ yield increases significantly when water is added into the Ar/methanol/ethanol mixtures. Moreover, optical emission spectroscopy has been applied to determine the gas temperature, the electron density and the radiative species present in the plasma torch. The results clearly show that this device provides an efficient plasma environment for hydrogen production.     

Gliding arc plasma oxidative steam reforming of a simulated syngas containing naphthalene and toluene

Conversion of a simulated syngas containing vaporized toluene and naphthalene was studied in a non-equilibrium gliding arc plasma reformer. The reformer was designed for efficient reforming of high temperature syngas (greater than 650 °C) containing heavy hydrocarbons, air, and water vapor. The reactor utilized forward vortex flow, where a preheated simulated syngas containing vaporized naphthalene and toluene tar surrogate was injected tangentially in the flow to ensure effective mixing and reforming of all components. At low tar concentration (30 g/m³), over 90% naphthalene and toluene conversion was achieved at the benchmark specific energy input of 0.1 kWh/m³ and energy efficiencies of 62.5 g/kWh for naphthalene and 215 g/kWh for toluene. At higher tar concentration (75 g/m³), over 70% naphthalene and toluene conversion was achieved at the benchmark specific energy input of 0.1 kWh/m³ and energy efficiencies of 93.6 g/kWh for naphthalene and 369 g/kWh for toluene. Explanations for the results include effective gas mixing and plasma chemistry, such as the very fast reaction kinetics from ions, radicals and active species, specifically hydroxyl.     

Experimental study on high temperature catalytic conversion of tars and organic sulfur compounds

A 400 cpsi noble metal catalyst was used to test the conversion of tars and sulfur containing hydrocarbons in the presence of steam, hydrogen sulfide and ethene. In order to reproduce producer gas from biomass gasification, higher molecular hydrocarbons (toluene, naphthalene, phenanthrene, pyrene) and sulfur containing hydrocarbons (thiophene, benzothiophene, dibenzothiophene) were added to a syngas. The syngas consisted of H₂, CH₄, H₂O, CO, CO₂ and N₂. The catalyst was operated at temperatures between 620 °C and 750 °C and at gas hourly space velocity (GHSV) of 9000 h⁻¹ and 18,000 h⁻¹.     

A novel silver oxides oxygen evolving catalyst for water splitting

A novel silver oxides oxygen evolving catalyst (Ag-OEC) for hydrogen production by water splitting was formed in situ on an indium tin oxide anode, in a near-neutral potassium tetraborate (K₂B₄O₇) electrolyte. The catalyst exhibited high activity and low overpotential for O₂ evolution under mild conditions. The main functional composition of the catalyst was a redox couple of Ag₂O/AgO. Catalytic activity during oxygen evolution was evaluated by cyclic voltammetry and Tafel plot. The effects of the concentration, temperature, and pH of K₂B₄O₇ solution on the catalyst, and the Faradaic efficiency of the oxygen evolving reaction were examined. The results show that the Ag-OEC exhibits excellent oxygen evolution properties, with an oxygen evolving overpotential of 318 mV at a current density of 1 mA/cm².     

Sc/Ti-decorated and B-substituted defective C60 as efficient materials for hydrogen storage

Doping heteroatoms and producing defects are perfect methods to improve the hydrogen storage property of TM-decorated carbon materials. In this view, four novel Sc/Ti-decorated and B- substituted defective C₆₀ fullerenes (B₂₄C₂₄) are explored. The special stability, large specific surface, uniform distribution of the metal and positively charged states make these four fullerenes have high hydrogen storage capacities. Especially, each Sc atom in Sc₆B₂₄C₂₄(B₄) can adsorb up to five H₂ molecules with a storage capacity of 6.80 wt %. The adsorbed H₂ molecules in Sc₆B₂₄C₂₄(B₄)–30H₂ begin to relax at 190 K and are 100% released at 290 K. Moreover, a comparative study is carried out for hydrogen storage properties of Sc-decorated B₄, C₄, or N₄ coordination environments. These results provide a new focus on the nature of B-, and N-substituted defective carbon nanomaterials.     

Hydrogen-rich gas production from biomass steam gasification in an updraft fixed-bed gasifier combined with a porous ceramic reformer

This paper investigates the hydrogen-rich gas produced from biomass employing an updraft gasifier with a continuous biomass feeder. A porous ceramic reformer was combined with the gasifier for producer gas reforming. The effects of gasifier temperature, equivalence ratio (ER), steam to biomass ratio (S/B), and porous ceramic reforming on the gas characteristic parameters (composition, density, yield, low heating value, and residence time, etc.) were investigated. The results show that hydrogen-rich syngas with a high calorific value was produced, in the range of 8.10–13.40 MJ/Nm³, and the hydrogen yield was in the range of 45.05–135.40 g H₂/kg biomass. A higher temperature favors the hydrogen production. With the increasing gasifier temperature varying from 800 to 950 °C, the hydrogen yield increased from 74.84 to 135.4 g H₂/kg biomass. The low heating values first increased and then decreased with the increased ER from 0 to 0.3. A steam/biomass ratio of 2.05 was found as the optimum in the all steam gasification runs. The effect of porous ceramic reforming showed the water-soluble tar produced in the porous ceramic reforming, the conversion ratio of total organic carbon (TOC) contents is between 22.61% and 50.23%, and the hydrogen concentration obviously higher than that without porous ceramic reforming.     

Solid oxide cells with cermet of silver and gadolinium-doped-ceria symmetrical electrodes for high-performance power generation and water electrolysis

A cermet of silver and gadolinium-doped-ceria (Ag-GDC) is investigated as novel symmetrical electrode material for (ZrO₂)_0.92(Y₂O₃)_0.08 (YSZ) electrolyte-supported solid oxide cells (SOCs) operated in fuel cell (SOFC) and electrolysis (SOEC) modes. The electrochemical performances are evaluated by measuring the current density-voltage characteristics and impedance spectra of the SOCs. The activity of hydrogen and air electrodes is investigated by recording overpotential versus current density in symmetrical electrode cells, respectively in hydrogen and air, using a three-electrode method. Conventional hydrogen electrode, Ni-YSZ, and oxygen electrode, LSCF (La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ)-GDC, are tested as comparison. The results show that, as an oxygen electrode, Ag-GDC is more active than LSCF-GDC in catalyzing both oxygen reduction reaction (ORR) in an SOFC and oxygen evolution reaction (OER) in an SOEC. As a hydrogen electrode, Ag-GDC is more active than Ni-YSZ in catalyzing hydrogen oxidation reaction (HOR) in an SOFC and hydrogen evolution reaction (HER) in an SOEC, especially in high steam concentration. An SOC with symmetrical Ag-GDC electrodes operated in a fuel cell mode, with 3% H₂O humidified H₂ as the fuel, displays a peak power density of 395 mWcm^?2 at 800 °C. Its polarization resistance at open circuit voltage is 0.21 Ω cm². Ag-GDC electrode can be operated even at pure steam. An SOEC operated for electrolyzing 100% H₂O, the current density reaches 720 mA cm^?2 under 1.3 V at 800 °C.     

Steam reforming of volatile fatty acids (VFAs) over supported Pt/Al2O3 catalysts

Volatile fatty acids (VFAs), easily produced using acid fermentation of biomass, were used to generate hydrogen via steam reforming. Three short-chain carboxylic acids (C2-C4) - acetic, propionic and butyric acids - were used as model compounds in addition to VFAs produced in a typical anaerobic batch reactor. Catalytic steam reforming of VFAs using alumina-supported platinum catalysts was studied in a fixed-bed quartz reactor at various temperatures between 300 and 600 °C. The influence of reaction conditions such as temperature, oxygen to carbon ratio (O/C) and gas hourly space velocity (GHSV) was investigated. VFAs were successfully converted to CO_x and hydrogen. A hydrogen yield of up to 70% was achieved, based on typical stoichiometry at 600 °C and a GHSV of 25,000 h⁻¹. Temperature-programmed oxidation (TPO), X-ray diffraction (XRD) and pore size distribution (PSD) were used to characterize coke deposition. Graphitic carbon on catalysts was not identified by XRD, which implies that amorphous coke had formed in the small pores. The catalysts could be reactivated by oxidation and reduction. A detrimental effect on hydrogen yield was observed by adding a small amount of O₂ to the VFA feed, due to the high concentration of oxygen in the feed composition. Steam reforming of real VFAs (S/C = 9) in the acid fermentation of food waste was performed with different GHSVs at a reaction temperature of 600 °C. Conversion of VFAs decreased significantly with increasing GHSV, but the hydrogen selectivity was still above 60%. The conversion pathways of the VFAs to CO_x and hydrogen are most likely complex, particularly due to the variety of the chemical compounds present in the real VFAs. The steam reforming of VFAs was investigated over various noble metal (Ruthenium, Palladium, Rodium, Nickel) catalysts supported on alumina, the specific activity based on the active surface area decreased in the order of Ru > Pd∼Rh > Pt > Ni.     

CO2-promoted hydrolysis of KBH4 for efficient hydrogen co-generation

Hydrolysis of metal borohydrides in the presence of CO₂ has not been studied so far, although carbon dioxide contained in air is known to accelerate hydrogen generation. KBH₄ hydrolysis promoted by CO₂ gas put through an aqueous solution was studied by time-resolved ATR-FTIR spectroscopy, showing a transformation of BH₄⁻ into B₄O₅(OH)₄²⁻, and a drastically accelerated hydrogen production which can be completed within minutes. This process can be used to produce hydrogen on-board from exhaust gases (CO₂ and H₂O). We found a new intermediate, K₉[B₄O₅(OH)₄]₃(CO₃)(BH₄)·7H₂O, forming upon hydrolysis on air via a slow adsorption of the atmospheric CO₂. The same intermediate can be crystallized from partly hydrolyzed solutions of KBH₄ + CO₂, but not from the fully reacted sample saturated with CO₂. This phase was studied by single-crystal and powder X-ray diffraction, DSC, TGA, Raman, IR and elemental analysis, all data are fully consistent with the presence of the three different anions and of the crystallized water molecules. Its crystal structure is hexagonal, space group P-62c, with lattice parameters a = 11.2551(4), c = 17.1508(8) Å. Formation of the intermediate produces 16 mol of H₂ per mole of adsorbed CO₂ and thus is very efficient both gravimetrically and volumetrically. It allows also for an elimination of carbon dioxide from exhaust gases.     

Chemical looping steam reforming of ethanol without and with in-situ CO2 capture

Chemical looping steam reforming (CLSR) of ethanol using oxygen carriers (OCs) for hydrogen production has been considered a highly efficient technology. In this study, NiO/MgAl₂O₄ oxygen carriers (OCs) were employed for hydrogen production via CLSR with and without CaO sorbent for in-situ CO₂ removal (sorption enhanced chemical looping steam reforming, SE-CLSR). To find optimal reaction conditions of the CLSR process, including reforming temperatures, the catalyst mass, and the NiO loadings on hydrogen production performances were studied. The results reveal that the optimal temperature of OCs for hydrogen production is 650 °C. In addition, 96% hydrogen selectivity and a 'dead time' (the reduced time of OCs) less than 1 minute is obtained with the 1 g 20NiO/MgAl₂O₄ catalysts. The superior catalytic activity of 20NiO/MgAl₂O₄ is due to the maximal quantity of NiO loadings providing the most Ni active surface centers. High purity hydrogen is successfully produced via CLSR coupling with CaO sorbent in-situ CO₂ removal (SE-CLSR), and the breakthrough time of CaO is about 20 minutes under the condition that space velocity was 1.908 h^?1. Stability CLSR experiments found that the hydrogen production and hydrogen selectivity decreased obviously from 207 mmol to 174 mmol and 95%–85% due to the inevitable OCs sintering and carbon deposition. Finally, stable hydrogen production with the purity of 89%～87% and selectivity of 96%～93% was obtained in the modified stability SE-CLSR experiments.     

Effects of N2O addition on the ignition of H2–O2 mixtures: Experimental and detailed kinetic modeling study

Ignition delay times of H₂/O₂ mixtures highly diluted with Ar and doped with various amounts of N₂O (100, 400, 1600, 3200 ppm) were measured in a shock tube behind reflected shock waves over a wide range of temperatures (940–1675 K). The pressure range investigated during this work (around 1.6, 13 and 32 atm) allows studying the effect of N₂O on hydrogen ignition at pressure conditions that have never been heretofore investigated. Ignition delay times were decreased when N₂O was added to the mixture only for the higher nitrous oxide concentrations, and some changes in the activation energy were also observed at 1.5 and 32 atm. When it occurred, the decrease in the ignition delay time was proportional to the amount of N₂O added and depended on pressure and temperature conditions. A detailed chemical kinetics model was developed using kinetic mechanisms from the literature. This model predicts well the experimental data obtained during this study and from the literature. The chemical analysis using this model showed that the decrease in the ignition delay time was mainly due to the reaction N₂O + M ? N₂ + O + M which provides O atoms to strengthen the channel O + H₂ ? OH + H.