The Experts below are selected from a list of 147 Experts worldwide ranked by ideXlab platform
Guanyi Chen - One of the best experts on this subject based on the ideXlab platform.
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Technical review on jet fuel production
Renewable & Sustainable Energy Reviews, 2013Co-Authors: Guanyi ChenAbstract:In present study, we investigated jet fuel production process, including the crude oil-based conventional process, unconventional oil sources-based process, Fischer–Tropsch synthesis (F–T) process and renewable jet fuel process and analyzed the details of each jet fuel production process. Among these jet fuel production technologies, the F–T synthesis and renewable jet fuel process supply alternative fuels with potential environmental benefit of reduced life cycle greenhouse gas (GHG) emissions and the economic benefits associated with increased fuel availability and lower fuel costs. The F–T synthesis has a major advantage with the possibility of accepting any carbon-based input, which makes it suitable for using a variety of sources such as coal, natural gas and 2nd generation biomass as feedstocks. The renewable jet fuel process such as Bio-Synfining™ (Syntroleum) and Ecofining™ (UOP) as well as C-L™ (Tianjin University) is a low capital cost process of producing high quality synthetic paraffinic kerosene (SPK) from bio-renewable feeds like vegetable oils/fats and waste cooking oils/fats, greases, energy plants of jatropha and algal. The SPK has superior fuel properties to other options available today, with higher cetane number, lower cloud point and lower emissions
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Technical review on jet fuel production
Renewable and Sustainable Energy Reviews, 2013Co-Authors: Guangrui Liu, Beibei Yan, Guanyi ChenAbstract:In present study, we investigated jet fuel production process, including the crude oil-based conventional process, unconventional oil sources-based process, Fischer-Tropsch synthesis (F-T) process and renewable jet fuel process and analyzed the details of each jet fuel production process. Among these jet fuel production technologies, the F-T synthesis and renewable jet fuel process supply alternative fuels with potential environmental benefit of reduced life cycle greenhouse gas (GHG) emissions and the economic benefits associated with increased fuel availability and lower fuel costs. The F-T synthesis has a major advantage with the possibility of accepting any carbon-based input, which makes it suitable for using a variety of sources such as coal, natural gas and 2nd generation biomass as feedstocks. The renewable jet fuel process such as Bio-Synfining™ (Syntroleum) and Ecofining™ (UOP) as well as C-L™ (Tianjin University) is a low capital cost process of producing high quality synthetic paraffinic kerosene (SPK) from bio-renewable feeds like vegetable oils/fats and waste cooking oils/fats, greases, energy plants of jatropha and algal. The SPK has superior fuel properties to other options available today, with higher cetane number, lower cloud point and lower emissions. © 2013 Published by Elsevier Ltd.
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Evaluation of Bio-Derived Synthetic Paraffinic Kerosenes (Bio-SKPs)
Energy and Fuels, 2010Co-Authors: Guangrui Liu, D L Daggett, Robert C Hendricks, Edwin Corporan, Clifford A Moses, Beibei Yan, Tim Edwards, Rainer Walther, Guanyi Chen, Frederick DryerAbstract:In 2009 a new ASTM specification (D7566-09, Standard Specification for Aviation Turbine Fuel Containing Synthesized Hydrocarbons) was developed for aviation turbine fuels. Contained in the D7566-09 specification is a specification for a synthetic paraffinic kerosene (SPK) blend component made from synthesis gas using the Fischer- Tropsch process commonly referred to as FT-SPK. Also contained in the D7566-09 specification is a specification for a blend of SPK with conventional petroleum based jet fuel. The specification allows for a maximum of a 50% blend of SPK with conventional jet fuel. It’s the intent of this report to demonstrate that a suitable SPK can be produced from a bio-derived source (Bio-SPK) that can satisfy the requirements outlined in D7566- 09. Further, it’s also the intent of this report to demonstrate that a 50% (v) Bio-SPK fuel blend with conventional petroleum jet fuel is suitable for use in turbine engines for commercial aviation. The report followed the guidelines outlined in the current version of ASTM D4054, “Standard Practice for the qualification and Approval of new Aviation Turbine Fuels and Fuels Additives”. Samples of Bio-SPK fuels were provided from six different fuel producers using a variety of feedstocks. The 100% and 50% (v) Bio-SPK fuels were compared to 100% and 50% (v) FT-SPK fuels using the same analytical method and plotted on the same graph whenever possible. FT-SPK fuel samples were produced by Sasol, Syntroleum, and Shell. In addition to the extensive amount of analytical fit-for purpose testing that was performed on both the Bio-SPK and FT-SPK neat and fuel blends the report includes engine ground test data using Bio-SPK fuel blends conducted by GE/CFM and Honeywell. The engine ground tests included performance, operability, and emission testing. Data obtained from three Bio-SPK test flights with Air New Zealand, Continental Airlines, and Japan Airlines are also included in this report. The fuel used for all three tests flights were a 50% (v) blend of Bio-SPK with conventional jet fuel (Jet A or Jet A- 1). Evaluation of Bio-Derived Synthetic Paraffinic Kerosenes (Bio-SPKs) Version 3.0 PAGE
Silke Schiewer - One of the best experts on this subject based on the ideXlab platform.
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Microbial Degradation of Different Hydrocarbon Fuels with Mycoremediation of Volatiles.
Microorganisms, 2020Co-Authors: Agota Horel, Silke SchiewerAbstract:Naturally occurring microorganisms in soil matrices play a significant role in overall hydrocarbon contaminant removal. Bacterial and fungal degradation processes are major contributors to aerobic remediation of surface contaminants. This study investigated degradation of conventional diesel, heating diesel fuel, synthetic diesel (Syntroleum), fish biodiesel and a 20% biodiesel/diesel blend by naturally present microbial communities in laboratory microcosms under favorable environmental conditions. Visible fungal remediation was observed with Syntroleum and fish biodiesel contaminated samples, which also showed the highest total hydrocarbon mineralization (>48%) during the first 28 days of the experiment. Heating diesel and conventional diesel fuels showed the lowest total hydrocarbon mineralization with 18–23% under favorable conditions. In concurrent experiments with growth of fungi suspended on a grid in the air space above a specific fuel with little or no soil, fungi were able to survive and grow solely on volatile hydrocarbon compounds as a carbon source. These setups involved negligible bacterial degradation for all five investigated fuel types. Fungal species able to grow on specific hydrocarbon substrates were identified as belonging to the genera of Giberella, Mortierella, Fusarium, Trichoderma, and Penicillium.
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impact of voc removal by activated carbon on biodegradation rates of diesel Syntroleum and biodiesel in contaminated sand
Science of The Total Environment, 2016Co-Authors: Agota Horel, Silke SchiewerAbstract:Abstract The degradation of conventional diesel (D), synthetic diesel (Syntroleum), and pure fish biodiesel (B100) by indigenous microbes was investigated in laboratory microcosms containing contaminated sand. The fate of volatiles and the influence of volatilization on degradation rates were examined by placing activated carbon (AC) in microcosm headspaces to sorb volatiles. Three AC regimes were compared: no activated carbon (NAC), regular weekly AC change (RAC), and frequent AC change (FAC), where the frequency of activated carbon exchange declined from daily to weekly. Generally, the alternative fuels were biodegraded faster than diesel fuel. Hydrocarbon mineralization percentages for the different fuel types over 28 days were between 23% (D) and 48% (B100) in the absence of activated carbon, decreased to 12% (D) – 37% (B100) with weekly AC exchange, and were further reduced to 9–22% for more frequent AC change. Sorption of volatiles to AC lowered their availability as a substrate for microbes, reducing respiration. Volatilization was negligible for the biodiesel. A mass balance for the carbon initially present as hydrocarbons in microcosms with activated carbon in the head space was on average 92% closed, with 45–70% remaining in the soil after 4 weeks, 9–37% mineralized and up to 12% volatilized. Based on nutrient consumption, up to 29% of the contaminants were likely converted into biomass.
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Effect of concentration gradients on biodegradation in bench-scale sand columns with HYDRUS modeling of hydrocarbon transport and degradation
Environmental Science and Pollution Research, 2015Co-Authors: Agota Horel, Silke Schiewer, Debasmita MisraAbstract:The present research investigated to what extent results obtained in small microcosm experiments can be extrapolated to larger settings with non-uniform concentrations. Microbial hydrocarbon degradation in sandy sediments was compared for column experiments versus homogenized microcosms with varying concentrations of diesel, Syntroleum, and fish biodiesel as contaminants. Syntroleum and fish biodiesel had higher degradation rates than diesel fuel. Microcosms showed significantly higher overall hydrocarbon mineralization percentages ( p
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Influence of inocula with prior hydrocarbon exposure on biodegradation rates of diesel, synthetic diesel, and fish-biodiesel in soil.
Chemosphere, 2014Co-Authors: Agota Horel, Silke SchiewerAbstract:Abstract To achieve effective bioremediation within short warm seasons of cold climates, microbial adaptation periods to the contaminant should be brief. The current study investigated growth phases for soil spiked with diesel, Syntroleum, or fish biodiesel, using microbial inocula adapted to the specific substrates. For modeling hydrocarbon degradation, multi-phase first order kinetics was assumed, comparing linear regression with nonlinear parameter optimization of rate constants and phase durations. Lag phase periods of 5 to >28 d were followed by short and intense exponential growth phases with high rate constants (e.g. from k Fish = 0.0013 ± 0.0002 to k Syntr = 0.015 ± 0.001 d −1 ). Hydrocarbon mineralization was highest for Syntroleum contamination, where up to three times higher cumulative CO 2 production was achieved than for diesel fuel, with fish biodiesel showing initially the slowest degradation. The amount of hydrocarbons recovered from the soil by GC–MS decreased in the order fish biodiesel > diesel > Syntroleum. During initial weeks, biodegradation was higher for microbial inocula adapted to a specific fuel type, whereby the main effect of the inoculum was to shorten the lag phase duration; however, the inoculum’s importance diminished after daily respiration peaked. In conclusion, addition of an inoculum to increase biodegradation rates was not necessary.
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Investigation of the physical and chemical parameters affecting biodegradation of diesel and synthetic diesel fuel contaminating Alaskan soils
Cold Regions Science and Technology, 2009Co-Authors: A. Horel, Silke SchiewerAbstract:Abstract In cold regions, biodegradation of fuel spills can take a prolonged period of time. Conventional fuels and crude oil contain contaminants such as aromatics and PAH which can pose risks to humans and the environment. The goal of the present study was therefore to investigate the biological degradation of an alternative synthetic fuel, Syntroleum, which is less toxic and, as shown in this study, more easily biodegradable than conventional diesel fuel. Use of alternative fuels such as Syntroleum would be especially beneficial in sensitive regions where spills of conventional fuel are highly undesirable. Gravel and sand from Interior Alaska were spiked with diesel and synthetic diesel fuel (arctic-grade Syntroleum). After adding an inoculum, samples were incubated in the laboratory at different temperatures (6 °C and 20 °C), contamination levels (2000 mg and 4000 mg of fuel/kg dry soil), nutrient dosages (300 mg N/kg soil and 0 mg N/kg soil) and moisture contents (2%, 4%, 8% and 12% gravimetric water content). The objective of this research was to investigate the effect of physical and chemical environmental conditions on the biodegradability of contaminants and to determine optimal conditions for biodegradation by indigenous microorganisms. The respiration rate (CO 2 production) was measured as an indicator of microbial activity and mineralization of contaminants, and complemented by analysis for hydrocarbons at the end of the experiment by gas chromatography/mass spectrometry. Both fuel types were biodegraded, with up to 75% mineralization after 17 weeks. The faster degradation rate was achieved in Syntroleum-contaminated soils with a degradation-rate constant of 0.0064–0.0106 d − 1 at 20 °C. At 6 °C, diesel fuel showed minimal degradation during several short-term studies (4–6 weeks), less than 5% total mineralization of the hydrocarbons in the fuel. The average degradation-rate constant for Syntroleum at 6 °C was 0.0016 d − 1 during a 4-week study, while the degradation-rate constants became much higher (0.0045–0.005 d − 1 ) for the long-term experiments (12–17 weeks), resulting in significant mineralization of total carbon present. The different moisture contents in the sandy soil showed no significant impact on respiration. The addition of fertilizer was essential to achieve good degradation rates. After the end of the 17-week experiment, the recovered contaminant was approximately 50% less in the case of Syntroleum when nutrients were added to the soil as compared with nutrient-deficient conditions. Respiration rates were higher in sand than in gravel, which may be due to differences in soil porosity and the available surface area for more even hydrocarbon distribution. Degradation rates varied significantly over time. A first-order model, which used different rate constants for three growth phases, was able to model cumulative carbon dioxide production quite well over a period of four months. In the carbon mass balance, the sum of the diesel range organics recovered from the soil plus the produced carbon dioxide accounted for approximately 30–85%. The remaining amount of carbon either was incorporated into biomass, degraded incompletely, or evaporated.
Eric L. Petersen - One of the best experts on this subject based on the ideXlab platform.
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Laminar Flame Speed Experiments of Alternative Liquid Fuels
Journal of Engineering for Gas Turbines and Power-transactions of The Asme, 2019Co-Authors: Charles L. Keesee, Eric L. PetersenAbstract:Abstract New laminar flame speed experiments have been collected for two alternative liquid fuels. Understanding the combustion characteristics of these synthetic fuels is an important step in developing new chemical kinetics mechanisms that can be applied to real fuels. Included in this study are two synthetic Jet fuels: Syntroleum S-8 and Shell GTL. The precise composition of these fuels is known to change from sample to sample. Since these are low-vapor pressure fuels, there are additional uncertainties in their introduction into gas-phase mixtures, leading to uncertainty in the mixture equivalence ratio. An in-situ laser absorption technique was implemented to verify the procedure for filling the vessel and to minimize and quantify the uncertainty in the experimental equivalence ratio. The diagnostic utilized a 3.39-μm HeNe laser in conjunction with Beer's law. The resulting spherically expanding, laminar flame experiments were conducted over a range of equivalence ratios from φ = 0.7 to φ = 1.5 at initial conditions of 1 atm and 403 K in the high-temperature, high-pressure (HTHP) constant-volume vessel at Texas A&M University. The experimental results show that both fuels have similar flame speeds with a peak value just under 60 cm/s. However, it is shown that when comparing the results from different datasets for these real fuels, equivalence ratio may not be the best parameter to use. Fuel mole fraction may be a better parameter to use as it is independent of the average fuel molecule or fuel surrogate used to calculate equivalence ratio in these real fuel/air mixtures.
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Autoignition Study of “Gas-to-Liquid” Fischer-Tropsch Jet Fuels
Volume 3: Coal Biomass Hydrogen and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration; Organic Rankine Cycle Power Sys, 2019Co-Authors: Sulaiman A. Alturaifi, Tatyana M. Atherley, Olivier Mathieu, Eric L. PetersenAbstract:Abstract In recent years, there has been an interest in finding a jet fuel alternative to the crude oil-based kerosene. Gas-to-liquid (GtL) fuel is being derived via Fischer-Tropsch synthesis processes by converting natural gas to longer-chain hydrocarbons which form the basis for jet fuel. In this study, new experimental ignition delay time measurements of GtL jet fuels have been determined at elevated pressures and temperatures. The measurements were conducted in a heated, high-pressure shock-tube facility capable of initial temperatures up to 200°C. Two GtL jet fuels were investigated, Shell GTL and Syntroleum S-8, which can be used in aviation applications at concentrations up to 50% blended with conventional oil-based kerosene. The ignition delay time measurements were conducted behind reflected shock waves for gaseous-phase fuel in air at a pressure around 10 atm and over a temperature range of 966 to 1266 K for two equivalence ratios, fuel lean (ϕ = 0.5) and stoichiometric (ϕ = 1.0). Ignition delay time was determined by observing the pressure and electronically excited OH chemiluminescence around 307 nm at the endwall location. Similar ignition delay times were observed for the two fuels at the fuel lean condition, while Syntroleum S-8 showed shorter ignition delay times at the stoichiometric condition. Comparisons are made with ignition delay time measurements for Jet-A previously conducted in the same facility and showed reasonable agreement over the tested conditions. The predictions from the available literature for GtL fuel surrogate kinetics models were obtained and compared with the experimental measurements.
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Laminar Flame Speed Experiments of Alternative Liquid Fuels
Volume 3: Coal Biomass Hydrogen and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration; Organic Rankine Cycle Power Sys, 2019Co-Authors: Charles L. Keesee, Eric L. PetersenAbstract:Abstract New laminar flame speed experiments have been collected for multiple alternative liquid fuels. Understanding the combustion characteristics of these synthetic fuels is an important step in developing new chemical kinetics mechanisms that can be applied to real fuels. Included in this study are two synthetic Jet fuels: Syntroleum S-8 and Shell GTL. The precise composition of these fuels is known to change from sample to sample. Since these are low vapor pressure fuels, there are additional uncertainties in their introduction into gas-phase mixtures, leading to uncertainty in the mixture equivalence ratio. An in-situ laser absorption technique was implemented to verify the procedure for filling the vessel and to minimize and quantify the uncertainty in the experimental equivalence ratio. The diagnostic utilized a 3.39-μm HeNe laser in conjunction with Beer’s Law. The resulting spherically expanding flame experiments were conducted over a range of equivalence ratios from φ = 0.7 to φ = 1.5 at initial conditions of 1 atm and 403 K in the high-temperature, high-pressure constant-volume vessel at Texas A&M University. The experimental results show that both fuels have similar flame speeds with a peak value just under 60 cm/s. However, it is shown that when comparing the results from different data sets for these real fuels, equivalence ratio is not necessarily the best parameter to use. Fuel mole fraction may be a better parameter to use as it is independent of the average fuel molecule or fuel surrogate used to calculate equivalence ratio in these real fuel/air mixtures.
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Fischer-Tropsch Fuel Characterization via Microturbine Testing and Fundamental Combustion Measurements
Volume 1: Aircraft Engine; Ceramics; Coal Biomass and Alternative Fuels; Manufacturing Materials and Metallurgy; Microturbines and Small Turbomachiner, 2008Co-Authors: Aditya Srinivasan, B. Ellis, John Crittenden, William E. Lear, Brandon Rotavera, Eric L. PetersenAbstract:Synthetic fuels such as Fischer-Tropsch (FT) fuels are of interest as a replacement for aviation, diesel, and other petroleum-based fuels, and the present paper outlines a joint program to study the combustion behavior of FT synthetic fuels. To this end, shock-tube spray and high-recirculation combustion rig experiments are being utilized to study the ignition delay times, formation of soot, and emissions of FT jet fuels. Undiluted shock tube spray experiments were conducted using a recently developed heterogeneous technique wherein the fuel is sprayed directly into the test region of a shock tube. The high recirculation combustion rig is a complete gas turbine system where Syntroleum FT jet fuel was combusted, and soot formation and emission characteristics were observed. Reduction of soot volume fraction and unchanged emissions were observed, in agreement with previous investigations. The fundamental shock tube results were found to be consistent with the observations made in the experimental engine.Copyright © 2008 by ASME
Guangrui Liu - One of the best experts on this subject based on the ideXlab platform.
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Technical review on jet fuel production
Renewable and Sustainable Energy Reviews, 2013Co-Authors: Guangrui Liu, Beibei Yan, Guanyi ChenAbstract:In present study, we investigated jet fuel production process, including the crude oil-based conventional process, unconventional oil sources-based process, Fischer-Tropsch synthesis (F-T) process and renewable jet fuel process and analyzed the details of each jet fuel production process. Among these jet fuel production technologies, the F-T synthesis and renewable jet fuel process supply alternative fuels with potential environmental benefit of reduced life cycle greenhouse gas (GHG) emissions and the economic benefits associated with increased fuel availability and lower fuel costs. The F-T synthesis has a major advantage with the possibility of accepting any carbon-based input, which makes it suitable for using a variety of sources such as coal, natural gas and 2nd generation biomass as feedstocks. The renewable jet fuel process such as Bio-Synfining™ (Syntroleum) and Ecofining™ (UOP) as well as C-L™ (Tianjin University) is a low capital cost process of producing high quality synthetic paraffinic kerosene (SPK) from bio-renewable feeds like vegetable oils/fats and waste cooking oils/fats, greases, energy plants of jatropha and algal. The SPK has superior fuel properties to other options available today, with higher cetane number, lower cloud point and lower emissions. © 2013 Published by Elsevier Ltd.
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Evaluation of Bio-Derived Synthetic Paraffinic Kerosenes (Bio-SKPs)
Energy and Fuels, 2010Co-Authors: Guangrui Liu, D L Daggett, Robert C Hendricks, Edwin Corporan, Clifford A Moses, Beibei Yan, Tim Edwards, Rainer Walther, Guanyi Chen, Frederick DryerAbstract:In 2009 a new ASTM specification (D7566-09, Standard Specification for Aviation Turbine Fuel Containing Synthesized Hydrocarbons) was developed for aviation turbine fuels. Contained in the D7566-09 specification is a specification for a synthetic paraffinic kerosene (SPK) blend component made from synthesis gas using the Fischer- Tropsch process commonly referred to as FT-SPK. Also contained in the D7566-09 specification is a specification for a blend of SPK with conventional petroleum based jet fuel. The specification allows for a maximum of a 50% blend of SPK with conventional jet fuel. It’s the intent of this report to demonstrate that a suitable SPK can be produced from a bio-derived source (Bio-SPK) that can satisfy the requirements outlined in D7566- 09. Further, it’s also the intent of this report to demonstrate that a 50% (v) Bio-SPK fuel blend with conventional petroleum jet fuel is suitable for use in turbine engines for commercial aviation. The report followed the guidelines outlined in the current version of ASTM D4054, “Standard Practice for the qualification and Approval of new Aviation Turbine Fuels and Fuels Additives”. Samples of Bio-SPK fuels were provided from six different fuel producers using a variety of feedstocks. The 100% and 50% (v) Bio-SPK fuels were compared to 100% and 50% (v) FT-SPK fuels using the same analytical method and plotted on the same graph whenever possible. FT-SPK fuel samples were produced by Sasol, Syntroleum, and Shell. In addition to the extensive amount of analytical fit-for purpose testing that was performed on both the Bio-SPK and FT-SPK neat and fuel blends the report includes engine ground test data using Bio-SPK fuel blends conducted by GE/CFM and Honeywell. The engine ground tests included performance, operability, and emission testing. Data obtained from three Bio-SPK test flights with Air New Zealand, Continental Airlines, and Japan Airlines are also included in this report. The fuel used for all three tests flights were a 50% (v) blend of Bio-SPK with conventional jet fuel (Jet A or Jet A- 1). Evaluation of Bio-Derived Synthetic Paraffinic Kerosenes (Bio-SPKs) Version 3.0 PAGE
Hameed Metghalchi - One of the best experts on this subject based on the ideXlab platform.
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Effects of diluent on laminar burning speed and flame structure of gas to liquid fuel air mixtures at high temperatures and moderate pressures
Fuel, 2018Co-Authors: Ziyu Wang, Guangying Yu, Sai C. Yelishala, Hameed MetghalchiAbstract:Abstract Gas to liquid (GTL) fuel has gained attention recently because of its clean combustion behavior. Experimental studies have been performed to investigate fundamental combustion characteristics such as laminar burning speed and flame structure of GTL/air/diluent premixed flames. In the present study, the GTL fuel was designated by Syntroleum S-8, supplied by US Air Force Research Laboratory (AFRL), which was synthesized from natural gas using the Fisher–Tropsch (F–T) process. A mixture of 32% iso-octane, 25% n-decane and 43% n-dodecane by volume was used as a surrogate for GTL fuel. In this work, two diluent concentrations of 5% and 10% were used. The diluent is a blend of 86% N2 and 14% CO2 having the same specific heat as the burned gases. Experiments were conducted using a spherical vessel for laminar burning speeds measurement and a cylindrical vessel to investigate the flame structures. The cylindrical vessel was set up in a Z-shape Schlieren system coupled with a high-speed CMOS camera that was used to capture evolutionary behavior of flames at up to 40,000 frames per second. A multi-shell thermodynamic model was used to calculate the laminar burning speed for the smooth and low stretch flames. During the flame expansion, measured pressure rise as a function of time was the input into the thermodynamic model. Power law correlations for laminar burning speeds of GTL/air/diluent premixed flames over a wide range of temperatures (from 490 K to 610 K), pressures (from 0.5 atm to 3.2 atm), equivalence ratios (from 0.7 to 1.2), and two different diluent concentrations of 5% and 10% have been reported. Experimental burning speed results were compared with simulation values calculated by the solution of one dimensional steady premixed flame code from CANTERA using Ranzi’s chemical kinetics mechanisms. Results of simulations are close to the measured values.
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Flame structure and laminar burning speed of gas to liquid fuel air mixtures at moderate pressures and high temperatures
Fuel, 2017Co-Authors: Ziyu Wang, Guangying Yu, Mohammed Alswat, Moaz Omar Allehaibi, Hameed MetghalchiAbstract:Abstract Gas to liquid (GTL) fuel, synthesized from natural gas through Fisher–Tropsch (F–T) process, has gained significant attention due to its cleaner combustion characteristics when compared to conventional fuels. Combustion properties such as flame structure and laminar burning speed of GTL/air mixture premixed flames have been investigated. The GTL fuel used in this research was provided by Air Force Research Laboratory (AFRL), designated by Syntroleum S-8, which was derived from natural gas via F–T process. A mixture of 32% iso-octane, 25% n-decane, and 43% n-dodecane by volume is considered as the surrogates of GTL fuel for filling process. Experiments were conducted using a cylindrical chamber to study the flame structure and a spherical chamber for laminar burning speeds measurement. The cylindrical chamber was set up in a Z-shape schlieren system coupled with a high-speed CMOS camera that was used to capture evolutionary behavior of flames at up to 40,000 frames per second. Pressure rise as a function of time during the flame propagation in the spherical vessel was the primary input of the multi-shell thermodynamic model used to calculate the laminar burning speed for the smooth flames. Power law correlations over a wide range of pressures (from 0.5 atm up to 4.3 atm), temperatures (from 490 K up to 620 K), and equivalence ratios (from 0.7 to 1.2) have been developed for laminar burning speeds of GTL/air flames. Experimental burning speed results have been compared with simulation values obtained by the solution of one dimensional steady premixed flame code from CANTERA using Ranzi’s chemical kinetics mechanisms. Comparisons show very good agreement with the available experimental data in this study.
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Theoretical Prediction of Laminar Burning Speed and Ignition Delay Time of Gas-to-Liquid Fuel
Journal of Energy Resources Technology-transactions of The Asme, 2016Co-Authors: Guangying Yu, Omid Askari, Fatemeh Hadi, Ziyu Wang, Hameed Metghalchi, Kumaran Kannaiyan, Reza SadrAbstract:Gas-to-liquid (GTL), an alternative synthetic jet fuel derived from natural gas through Fischer–Tropsch (F–T) process, has gained significant attention due to its cleaner combustion characteristics when compared to conventional counterparts. The effect of chemical composition on key performance aspects such as ignition delay, laminar burning speed, and emission characteristics has been experimentally studied. However, the development of chemical mechanism to predict those parameters for GTL fuel is still in its early stage. The GTL aviation fuel from Syntroleum Corporation, S-8, is used in this study. For theoretical predictions, a mixture of 32% iso-octane, 25% n-decane, and 43% n-dodecane by volume is considered as the surrogate for S-8 fuel. In this work, a detailed kinetics model (DKM) has been developed based on the chemical mechanisms reported for the GTL fuel. The DKM is employed in a constant internal energy and constant volume reactor to predict the ignition delay times for GTL over a wide range of temperatures, pressures, and equivalence ratios. The ignition delay times predicted using DKM are validated with those reported in the literature. Furthermore, the steady one-dimensional premixed flame code from CANTERA is used in conjunction with the chemical mechanisms to predict the laminar burning speeds for GTL fuel over a wide range of operating conditions. Comparison of ignition delay and laminar burning speed shows that the Ranzi et al. mechanism has a better agreement with the available experimental data, and therefore is used for further evaluation in this study.
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Auto-Ignition Characteristics Study of Gas-to-Liquid Fuel at High Pressures and Low Temperatures
Journal of Energy Resources Technology-transactions of The Asme, 2016Co-Authors: Omid Askari, Mimmo Elia, Matthew Ferrari, Hameed MetghalchiAbstract:Onset of auto-ignition of premixed gas-to-liquid (GTL)/air mixture has been determined at high pressures and low temperatures over a wide range of equivalence ratios. The GTL fuel used in this study was provided by Air Force Research Laboratory (AFRL), designated by Syntroleum S-8, which is derived from natural gas via the Fischer–Tropsch (F–T) process. A blend of 32% iso-octane, 25% n-decane, and 43% n-dodecane is employed as the surrogates of GTL fuel for chemical kinetics study. A spherical chamber, which can withstand high pressures up to 400 atm and can be heated up to 500 K, was used to collect pressure rise data, due to combustion, to determine the onset of auto-ignition. A gas chromatograph (GC) system working in conjunction with specialized heated lines was used to verify the filling process. A liquid supply manifold was used to allow the fuel to enter and evaporate in a temperature-controlled portion of the manifold using two cartridge heaters. An accurate high-temperature pressure transducer was used to measure the partial pressure of the vaporized fuel. Pressure rise due to combustion process was collected using a high-speed pressure sensor and was stored in a local desktop via a data acquisition system. Measurements for the onset of auto-ignition were done in the spherical chamber for different equivalence ratios of 0.8–1.2 and different initial pressures of 8.6, 10, and 12 atm at initial temperature of 450 K. Critical pressures and temperatures of GTL/air mixture at which auto-ignition takes place have been identified by detecting aggressive oscillation of pressure data during the spontaneous combustion process throughout the unburned gas mixture. To interpret the auto-ignition conditions effectively, several available chemical kinetics mechanisms were used in modeling auto-ignition of GTL/air mixtures. For low-temperature mixtures, it was shown that auto-ignition of GTL fuel is a strong function of unburned gas temperature, and propensity of auto-ignition was increased as initial temperature and pressure increased.
