Propanol Isomers Research Articles

Study on laminar combustion characteristics and the optimization of the coupling mechanism in a mixture of propanol and gasoline

When both isopropanol and n-propanol are incorporated, the utilization of propanol as a fuel substitute (or a gasoline additive) presents promising potential for enhancing the combustion efficiency and thermal performance in compact, turbocharged, direct-injection gasoline engines upon blending. However, the complexity of the laminar combustion behavior of propanol-blended gasoline has yet to be fully investigated, as current coupling mechanisms are insufficiently sophisticated to precisely mirror the complex experimental conditions.This study establishes a testbed specifically designed for measuring laminar burning velocity (LBV) using the heat flux method. This setup is employed to measure the LBV of pure n-heptane and isooctane, as well as the LBV of the gasoline surrogate fuel TRF with two distinct blend ratios. Additionally, it measures the LBV of propanol and its blends with TRF. The research findings reveal that isooctane demonstrates a heightened sensitivity to fuel preheating temperature, whereas the toluene proportion in TRF fuels exerts the most pronounced influence on combustion behavior. At an equivalence ratio of 1.1, the LBV of n-propanol differs from that of its isomer, isopropanol, by 4.65 cm/s. Notably, the LBV exhibits a discernible upward trend, corresponding to the increasing proportion of toluene in the blended fuel. Furthermore, there is a pronounced distinction in LBV among the propanol isomers, with blended TRF occupying an intermediate position between pure propanol and TRF. After the enhancement of the mechanism based on experimental benchmarks of LBV, a rigorous validation process demonstrated a substantial improvement in the alignment between simulated outcomes and empirical LBV measurements.

Propeller shaped triarylamine acid: An ultra-sensitive fluorescence probe for distinguishing propanol isomers and water sensing in organic solvents

The photophysical properties of conformationally flexible (TPA-C) and partially rigidified (Cz-C) triarylamine acids were explored in solid as well as solution state and correlated with the structure. TPA-C and Cz-C exhibited moderate solid-state fluorescence (Φf = 6.2 % (TPA-C) and 5.6 % (Cz-C)) and self-reversible mechanofluorochromism. TPA-C produced fluorescent polymorphs (TPA-C-1 and TPA-C-2) with tunable fluorescence. TPA-C-1 showed unusual carboxylic acid intermolecular interactions whereas TPA-C-2 and Cz-C showed usual carboxylic acid dimer. TPA-C exhibited strong solvent polarity dependent tunable fluorescence (Φf = 0.01 to 0.11 compared to quinine sulphate standard) but Cz-C was non-emissive in the solution state. The dual emissive TPA-C showed highly sensitive fluorescence changes in organic solvents (CH3CN, THF, DMF, EtOH) when trace amount of water was added. In CH3CN, TPA-C showed weak fluorescence at 474 nm and addition of water (1 %) exhibited significant blue shift (λmax = 416 nm). The fluorescence intensity was gradually decreased with blue shifting in DMF, THF and EtOH with water addition. Importantly, TPA-C showed drastically different fluorescence in n-propanol (n-PA) and iso-propanol (IPA). TPA-C in n-PA showed fluorescence at 408 nm that was clearly red shifted to 438 nm with 0.1 % addition of IPA. The limit of detection (LOD) of water in CH3CN, DMF, THF and EtOH by TPA-C revealed 0.02, 0.7, 0.08 and 0.77 %, respectively. The LOD of IPA sensing in n-PA is 0.05 % and indicated the very efficient sensing and distinguishing propanol isomers. Thus, simple triphenylamine acid showed excellent water sensing and propanol isomers discrimination that could be attributed to the twisted intramolecular charge transfer (TICT) formation.

Studies on thermodynamics properties of binary mixtures of amyl acetate with propanol at T = 298.15 K to 318.15 K

The thermophysical properties of amyl acetate and isomers of propanol are critical for a variety of industrial, scientific, and safety–related applications. The density (ρ), viscosity (η), speed of sound (u), and refractive index (nD) of binary amyl acetate (1) + propanol (2) mixtures were measured at T = 298.15 K–318.15 K and pressure of 0.1 MPa. The excess molar volume (VmE), deviation in viscosity (Δη), deviation in speed of sound (Δu), excess isentropic compressibility (κsE), and deviation in refractive index (ΔnD) were derived from measured data. The deviation parameters in binary mixtures are affected by H–bonding, interstitial accommodation, and dipole–dipole interactions. The VmE, Δη and κsE values were described with Graph theory, Prigogine-Flory-Patterson (PFP) theory, Singh model, and ab–initio approach. While the VmE and Δη rise with increment in temperature whereas Δu and ΔnD decrease with increase in temperature.

Volumetric and acoustic studies of binary mixtures of n-butylamine with propanol at T = (298.15-318.15) K

ABSTRACT This study investigated the molecular interactions within mixtures of n-butylamine (NBA) and isomers of propanol. We conducted an exhaustive analysis of excess molar volume ( V m E ), deviation in ultrasonic speed ( Δ u ), and excess isentropic compressibility ( κ s E ) by utilising the measured data of density ( ρ ) and ultrasonic speed ( u ) at T = 298.15 K to 318.15 K under pressure at 0.1 MPa. This led to the derivation of secondary properties such as partial ( V ˉ i ), excess partial ( V ˉ iE ), and apparent molar volume ( V φi ). As the temperature rises, the V m E become more negative, while the Δu values more positive. The RK equation was employed to fit the excess properties data, with further exploration through additional theories. The findings presented here offer vital insights into amine – alcohol mixtures and their thermodynamic and acoustic properties, which are invaluable for optimising related chemical engineering and industrial processes.

Experimental investigation and modeling of boundary layer flashback for non-swirling premixed prevaporized n-propanol/air and /isopropanol/air flames

The idea of utilizing lean, premixed and prevaporized (LPP) combustion could be a step towards sustainable aviation in the future, with the absolute absence of soot particles and very low nitrogen oxide emissions. However, premixing with compressed hot air presents a challenge for both conventional jet fuel and synthetically produced sustainable aviation fuel (SAF) due to self-ignition and flashbacks. Our group is thus seeking LPP-compatible advanced sustainable aviation fuels, which are evaluated based on their flashback propensity. Preliminary studies indicate that short-chain alcohols, with their higher ignition delay times and lower flame velocities, may be appropriate for LPP combustion concepts. In this study, the isomers of propanol, n-propanol, and isopropanol, are the first representatives of the short-chain alcohols to be investigated experimentally and numerically with respect to their flame stability limits. The experimental determination of stability limits for n- and isopropanol/air premixed flames was conducted on a generic, non-swirled atmospheric burner for an equivalence ratio range of 0.82 to 1.11. A fully automated measurement procedure was used to generate 119 measurement points with Reynolds numbers in the range from 1430 to 2750. The influence of the positional isomerism and of the preheat temperature (422 K, 446 K and 466 K) of the unburned mixture are investigated. A clear influence of the isomeric fuel structure is found. A theoretical analysis shows that it can be related to the different laminar flame speed and laminar flame thickness of the isomers. Moreover, a detailed analysis shows that the critical velocity gradient concept to describe boundary layer flashback is well usable with a Péclet number model.

Volumetric, acoustic, and optical properties of binary mixtures of diethyl ether with alkanol at T = 293.15 K to 303.15 K

Density (ρ), ultrasonic speed (u), and refractive index (nD) of binary liquid mixtures such as diethyl ether (DEE) (1) + alkanol (isomers of propanol and 1-butanol) (2) were experimentally measured at T = 293.15 K to 303.15 K and at 0.1 MPa pressure. By using these measurements excess molar volume (VmE), deviation in ultrasonic speed (Δu), excess isentropic compressibility (κsE), and deviation in refractive index (ΔnD) were computed and associated with the Redlich-Kister polynomial equation. It was found that deviation parameters are influenced by H–bonding, interstitial accommodation, and dipole–dipole molecular interactions between binary mixtures. The VmE values have been interpreted by the Prigogine–Flory–Patterson (PFP) theory and the Flory–Treszczanowicz–Benson (FTB) model. The FTB model and PFP theory anticipated the VmE curves and were able to depict the perfect shape and magnitude of VmE values. The numeric values of u and nD were computed by using several empirical correlations and mixing rules. This study discusses the comparative significance of these relationships with the measured values of u and nD.

An Experimental Investigation into the Performance and Emission Characteristics of a Gasoline Direct Injection Engine Fueled with Isopropanol Gasoline Blends

Propanol isomers, which are oxygen-rich fuels, possess superior octane ratings and energy density in comparison to methanol and ethanol. Recently, due to advancements in fermentation techniques, these propanol isomers have garnered increased interest as additives for engines. They are being explored to decrease emissions and reduce the usage of conventional fossil fuels. This study delves into this emerging field. One of the alternatives is the use of alcohol fuels in their pure state or as additives to traditional fuels. Alcohols, due to their higher volumetric energy density, are better fuels for spark ignition engines than hydrogen and biogas. Alcohol-blended fuels or alcohol fuels in their pure state may be used in gasoline engines to reduce exhaust emissions. The current research emphasizes the effect of isopropanol gasoline blends on the performance and emissions characteristics of a gasoline direct injection (GDI) engine. This investigation was conducted with different blends of isopropanol and gasoline (by volume: 10% isopropanol [IP10], 20% isopropanol [IP10], 30% isopropanol [IP30], 40% isopropanol [IP40], and 50% isopropanol [IP50]). The reviewed results showed that with increasing isopropanol in the fuel blends, engine brake power increased while BSFC decreased. In terms of emissions, with the increase in isopropanol in the fuel blends, CO and HC emissions decreased while CO2 and NOx emissions increased.

Ozone-initiated low-temperature oxidation of two propanol isomers: revealing the effects of Ö/ȮH atoms/radicals

The low-temperature oxidation of propanol isomers (n-propanol and iso-propanol) initiated by ozone addition was carried out in a jet-stirred reactor at an equivalence ratio of 0.5, in a temperature range of 400–800 K and at atmospheric pressure. Synchrotron vacuum ultraviolet photoionization mass spectrometry was used to follow the temperature dependence of key intermediates, including aldehydes, ketones, hydroperoxides, alcohols, alkanes, and alkenes, to explore their low-temperature oxidation reaction pathways. n-Propanol and iso-propanol presented different intermediate distributions during low-temperature oxidation, due to the different position of the hydroxyl group in the molecular structure. The elucidation of the distribution of these intermediate species contributed to the understanding of the low-temperature oxidation reaction network of n-propanol and iso-propanol. Furthermore, a detailed kinetic model of propanol isomers was tentatively developed by systematically updating the sub-mechanism of β-hydroxypropyl radical and by adding the four reaction channels for CO2 formation. These four reactions involve the reactions of the Ö/ȮH atom/radical with formaldehyde/acetaldehyde. The rate of production analysis reveals the crucial roles of Ö/ȮH atoms/radicals on the whole reaction process, highlighting the controlling effects of reactions directly related to Ö/ȮH atoms/radicals. Especially, the reaction between HȮ2 radicals and ozone dominates ȮH radical formation at lower temperatures of ca. 400–475 K, while Waddington reactions, the cyclization reactions of hydroperoxyl hydroxyalkyl radicals and the H-atom abstraction reactions of fuels/intermediates are dominantly responsible for the formation of ȮH radicals at elevated temperatures of ca. > 500 K.

Crossed-Beam Imaging of the Reaction of OH with Propanol Isomers.

We present a crossed-beam imaging study of the reactions of OH radicals with 1- and 2-propanol at a collision energy of 8 kcal mol-1 using 157 nm probe of the radical product. Our detection is selective for the α-H and β-H abstraction in the 1-propanol case and for the α-H abstraction only in the 2-propanol case. The results show direct dynamics. A sharply peaked backscattered angular distribution is seen for the 2-propanol system and broader backward-sideways scattering for 1-propanol consistent with the different abstraction sites. The translational energy distributions peak at ∼35% of the collision energy, far from the heavy-light-heavy kinematic propensity. As this is ∼10% of the available energy, substantial vibrational excitation in the water product is inferred. The results are discussed in relation to analogous OH + butane and O(3P) + propanol reactions.

Toward Planar Atomic-Gold Decorated Polyaniline Gas Sensors for Enhanced Electrochemical Sensing

With the rapid advancement in complex chemical information systems and biomimetic models, the need for chemical sensors with partially overlapping selectivities has grown more than ever. Fabrication of multiple sensing films for chemical sensing is tedious, and time-consuming-newer approaches are needed. By using novel sensing materials such as noble-metal-based single-atom catalysts decorated on conducting polymers, multiple sensing films can be fabricated. In this research, bi-atomic gold (or nanostructure of two gold atoms) electrocatalyst has been successfully decorated on a polyaniline (PANI) matrix to yield sensing films capable of discriminating between propanol isomers in both liquid and gas phases. Sensor miniaturization was achieved by combining the ionic liquid electrolyte and silver–silver chloride pseudo-reference on a planar substrate. The sensor was operational with a static electrochemical potential and the sensor response with bi-atomic gold was larger than with no gold electrode. Furthermore, the sensor with bi-atomic gold showed both linear and nonlinear response curves to each of the two propanol isomers pointing to selectivity. Sensor drift is a significant issue with such pseudo-reference electrode-based sensor configuration, and alternative approaches are suggested.

Comparative Study of the Adsorption of 1- and 2-Propanol on Ice by Means of Grand Canonical Monte Carlo Simulations

In this paper, we use Grand Canonical Monte Carlo simulations to compare the adsorption characteristics of two propanol isomers (1- and 2-propanol) on crystalline ice, at the temperature of 227 K (i.e., typical of the Earth’s troposphere), for which experimental data are available in the literature. The adsorption isotherms simulated for these two isomers show a very good agreement with the reported experimental data, giving thus confidence in the two interaction potential models used in the calculations. The results of the simulations thus nicely support the experimental conclusion that 2-propanol is preferentially adsorbed on ice with respect to 1-propanol, at least in the low pressure range where only a few molecules are trapped by the ice surface. The accuracy of the approach used, as tested here in tropospheric conditions, opens the way for its use in modeling studies also relevant to astrophysical context.

An Ultra‐Sensitive Fluorescent Probe Based on Hybridized Local and Charge‐Transfer Materials for Quantitative Detection of Propanol Isomers

AbstractIsopropanol has been widely applied in various fields as an important chemical solvent, which is produced by direct hydration of propylene accompanied with the byproduct of n‐propanol. Herein, an ultra‐sensitive fluorescent probe of TPA‐9AC, based on a non‐equivalent hybridized local and charge‐transfer (HLCT) material, is designed and synthesized to quantitatively detect the percentage of n‐propanol in propanol isomers. Owing to the stronger electron acceptor ability of n‐propanol, the excited state of probe transfers from highly emissive HLCT state to non‐emissive charge‐transfer state, resulting in the substantial fluorescence quenching. The low limit of detection (LOD) is achieved as sensitive as 0.02% v/v of n‐propanol in isopropanol. This contribution demonstrates a new approach to distinguish propanol isomers and an effective strategy for designing real‐time fluorescent sensors with high performances.

Sooting tendencies of ethylene diffusion flame doped by C[formula omitted]-C[formula omitted] alcohols

The sooting propensity of steady laminar coflow ethylene/air flames is modified doping the fuel stream with vapors of alcohol and evaluated as a function of both the position of the alcohol function and the ramification level (linear/branched) of the molecule. To identify general trends, a range of 3 alcohol sizes (C3, C4, and C5) are compared: the 2 propanol isomers (primary and secondary), the 4 butanol isomers (2 primaries with 1 branched, 1 secondary, 1 tertiary), and 7 pentanol isomers (3 primaries with 2 branched, 3 secondary with 1 branched and 1 tertiary). Every alcohol has been injected as a doping vapor in the central tube of a Santoro’s burner. To evaluate the sooting tendencies, a Line-of-Sight Attenuation (LOSA) setup allows the extinction of a collimated laser beam operating at 645 nm to be measured yielding the field of local soot volume fraction fv. Two indicators are used and contrasted, i.e. one using integrated data (raw data from the camera capturing the laser extinction) and one using the local field (deconvoluted data). From these results, several conclusions can be drawn. The two indicators being in good agreement, it seems unnecessary to obtain local data to compare sooting tendencies at different conditions (for a given experimental setup). The noise from the deconvolution procedure can be drastically reduced by a classical image processing described precisely in the paper, i.e. an average filter. These results reveal a good correlation between alkene produced in rich premixed C2H4 flame. The sooting tendencies are consistent with the literature: linear molecule < branched molecule and primary alcohol < secondary alcohol < tertiary alcohol. Moreover, the number of carbon NC, here varied from 3 to 5, leads to a modification of the sooting tendency that is significantly narrower than that associated with the structure of the alcohol at a given NC.

An experimental and kinetic modeling study on the effects of molecular structure on oxidation of propanol isomers at engine-relevant condition in a variable pressure laminar flow reactor

Fuel combustion mechanism at different temperature and pressure range can be highly divers. In combustion process, many reactions are strongly pressure-dependent. Reactions that are important at low pressures may not be that important when pressure gets higher. Kinetic models developed and validated only at atmospheric conditions can have a large deviation when directly applied for higher pressures. Thus, experimental and kinetic studies at elevated to high pressures are essential for the understanding of fuel properties at engine-relevant conditions. However, speciation studies at such conditions are rare, which limits prediction accuracy of kinetic models. Propanol is the smallest alcohol that has isomers, and can be produced via carbon–neutral routes. Study on propanol can reveal the effect of isomerization and facilitate kinetic studies of larger alcohols. In present work, experiments have been carried out at elevated pressure in a variable pressure laminar flow reactor. Speciation data has been measured and compared. Moreover, a previous kinetic model has been modified and validated to improve prediction accuracy at elevated pressure and has been used for further kinetic analysis. The structural difference between two isomers affects their oxidation pathways and intermediate species. The position of hydroxyl moiety and bond dissociation energy of α-H have led to different oxidation properties of these two isomers. Through present work, the effect of molecular structure on oxidation properties of propanol isomers at elevated pressure have been studied. Speciation database of propanol isomers at elevated pressure has been enriched, and prediction accuracy of a previous model at present conditions has been improved.

Difference in the hydration state of water at the hydrophobic interface of structural isomers of propanol investigated by U.V visible absorption and Raman spectroscopic study

In this work, the nature of hydration shell water around hydrophobic groups of alcohol has been investigated by studying the U.V visible absorption energy shift of p-nitro-aniline upon interaction with water-alcohol mixture in different proportion. Analysis shows that, at low mole fraction of alcohol the absorption energy shift with composition of alcohol-water mixture originates from the interaction of hydrophobically modified water with PNA. It is further observed that, the absorption energy changes nonlinearly with the chain length of alkyl group of alcohol. From Raman studies it is apparent that, the absorption energy shift originates from the changing population of dangling OH interacting with PNA. The central part of the study has been to investigate the difference in the hydrophobic environment due to variation in the arrangement of hydrophobic groups in propanol. The U.V visible absorption studies of PNA in 1-propanol and 2-propanol water mixture show that 1-propanol bears higher population of dangling OH compared to 2-propanol. In addition, we have also performed Raman spectroscopic studies in the region of OH stretch. The spectra of hydration shell water are extracted by RD-SCF method. The characteristic peak due to dangling OH was analyzed and it also shows 1-propanol to possess relatively higher amount of dangling OH compared to 2-propanol. This joint study confirms that arrangement of hydrophobic moiety in small molecules can affect the water hydrogen bonding of water at the hydrophobic interface.

Investigation on the autoignition characteristics of propanol and butanol isomers under diluted lean conditions for stratified low temperature combustion

Low-temperature combustion (LTC), which can be achieved through either fuel-lean mixtures or high dilution, is an effective way to reduce NOx and soot emission for an internal combustion engine. Alcohols are considered suitable fuels for LTC as they have the advantage of better fuel-air mixing, such as high autoignition resistance and fast vaporization. Propanol and butanol can be produced as bio- or electro-fuels, which are carbon-neutral and become candidates as transportation fuels. This work focuses on investigating the autoignition and emission behavior of these alcohols regarding the application in stratified LTC. The autoignition properties of propanol and butanol isomers have been investigated in a rapid compression machine (RCM) under 90% dilution, at temperatures from 800 K to 1100 K, pressures of 20 and 40 bar and equivalence ratios of 0.25, 0.5 and 0.9. Under all investigated conditions, the order of reactivity among butanol isomers is consistent, namely n-butanol > isobutanol ≅ 2-butanol > tert‑butanol, while n-propanol is always more reactive than isopropanol. The reactivity of propanol isomers is similar to that of iso and 2-butanol. It was observed in the measurement that the difference between the reactivity of different fuels was not constant in the investigated temperature range, which was explained by the autoignition chemistry transition between 800 K and 950 K. According to the modeling, emissions of all butanol and propanol isomers are similar. The non-diluted mixtures can only achieve low-temperature combustion (LTC) in extreme lean conditions, while the diluted mixtures can achieve LTC in a wider range of equivalence ratios and have both low NOx and hydrocarbon emissions.

Kinetic Modeling Study on the Combustion Characterization of Synthetic C3 and C4 Alcohols for Lean Premixed Prevaporized Combustion

To reach sustainable aviation, one approach is to use electro-fuels (e-fuels) within the gas turbine engines. E-fuels are CO2-neutral synthetic fuels which are produced employing electrical energy generated from renewable resources, where the carbon is taken out of the atmosphere or from biomass. Our approach is, to find e-fuels, which can be utilized in the lean premixed prevaporized (LPP) combustion, where most of the non-CO2 emissions are prevented. One of the suitable e-fuel classes is alcohols with a low number of carbons. In this work, the autoignition properties of propanol isomers and butanol isomers as e-fuels were investigated in a high-pressure shock tube (HPST) at temperatures from 1200 to 1500 K, the pressure of 10 bar, and lean fuel-air conditions. Additional investigations on the low-temperature oxidation and flame speed of C3 and C4 alcohols from the literature were employed to develop a comprehensive mechanism for the prediction of ignition delay time (IDT) and laminar burning velocity (LBV) of the above-mentioned fuels. A numerical model based on newly developed chemical kinetics was applied to further study the IDT and LBV of fuels in comparison to the Jet-A surrogate at the engine-related conditions along with the emissions prediction of the model at lean fuel-air conditions.

Theoretical kinetics of hydrogen abstraction reactions from propanol isomers by hydroperoxyl radical: Implication for combustion modeling

Propanol isomers are potential alternatives to conventional fossil fuels and have attracted considerable attentions from combustion community. Hydrogen atom abstraction reactions from alcohols by HO2 radical plays an important role in alcohol oxidation chemistry. In this work, the temperature-dependent rate constants and branching ratios of the hydrogen atom abstraction reactions from n-propanol and iso-propanol by HO2 were calculated using the multistructural variational transition state theory with small-curvature tunneling approach. Results show that the multistructural torsional anharmonicity effects significantly influence the calculation of site-specific rate constants and branching ratios, which need to be considered for reaction systems having multiple distinguishable structures. Significant discrepancy observed in the theoretically calculated rate constants from different sources highlight the necessity and importance of accurate calculation efforts, as it can provide the experimentally unavailable site-dependent rate constants and branching ratios. The effects of our newly calculated rate constants were examined by incorporating them into a recent chemical kinetic model developed by Saggese et al. The chemical kinetic model implemented with our newly calculated rate constants exhibits decreased fuel reactivity, especially at low temperatures and high pressures. Also, the chemical kinetic model using our theoretical calculations shows better prediction in the mole fractions of aldehydes, which are key oxidation intermediates in propanol oxidation.

High-temperature oxidation of propanol isomers in the mixtures with N2O at high Ar dilution conditions

This work provides, for the first time, new information regarding the kinetics interaction between N2O and propyl alcohol isomers. To this end, the formation and consumption of atomic oxygen were measured behind the reflected shock waves using Atomic Resonance Absorption Spectroscopy (ARAS) technique for 1–10 ppm n- i-propanol + 10 ppm N2O + Ar mixtures, at 2–3 bar and over a wide temperature range of 1700–3200 K. The Konnov and POLIMI detailed combustion mechanisms were assessed against experimental data and also employed to study the main reactions influencing the oxidation dynamics of fuel mixtures under the investigated conditions. The study highlighted a certain difficulty by the models tested in predicting the formation of atomic oxygen at T < 2000 K. The rate of production and the sensitivity analysis was performed with the attempt to identify the most important reactions involved in the process oxidation for future kinetic model refinements.

Effects of propanol isomers enrichment on in-cylinder thermochemical fuel reforming (TFR) in spark ignition natural gas engine

This paper investigates the effects of propanol isomers enrichment on natural gas TFR engine via experiment and simulation. The results indicate that the reforming effect of TFR cylinder with n-propanol enrichment is the best, followed by that with iso-propanol, and with that of the natural gas being the worst. The impact of negative effect due to lack of fire was the most significant on the reforming effects with n-propanol enrichment, less on those with iso-propanol, and the least on those with natural gas. According to the kinetics analysis, the rate of H2 formation depends on the rates of H, O, OH, and HO2 formation. The n-propanol had the fastest production rate for H, O, OH, and HO2 radicals in the early stage of combustion, compared with iso-propanol and methane. The performance analysis of the normal cylinder shows that n-propanol enriched normal cylinders produced the lowest fuel consumption.