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Several studies have found that pilot injection enhances the mixture and combustion of the main injection fuel, which effectively improves performance and reduces emission. However, only a few investigations have focused on remediating the negative effect of pilot injection, which is that it restricts the advancement of the split injection. Therefore we study the influence of pilot-main injection...
Ignition delay experiments for gas phase n-nonane/air mixtures have been performed behind reflected shock waves over a wide temperature range of 684–1448K, pressures of 2.0–15.0atm, and equivalence ratios of 0.5, 1.0, and 2.0. Ignition delay times were determined using electronically excited CH emission and reflected shock pressure signals monitored at the sidewall of the shock tube. A negative-temperature-coefficient...
This work reports the hydrogen production of aluminate spinel type materials, MAl2O4 (M=Mg, Sr, and Ba), prepared by solid state method. Characterization was carried out by means of X-ray diffraction (XRD), scanning electronic microscopic (SEM), UV–vis spectroscopy, BET method, chronoamperometry, and EIS. Through electrochemical impedance and UV–vis spectroscopy it was possible the determination of...
The swelling and sorption experiments were carried out simultaneously for two block coal samples under CO2 and CH4 pressure (up to 16MPa) at three temperatures (25, 45 and 65°C). The absolute sorption isotherms present type-II pattern and can be described by a modified BET model. The swelling isotherms present L-type pattern and can be described by a modified Langmuir model. The relationship between...
Different tests used to predict asphaltene stability in crude oils, such as colloidal instability index, colloidal stability index, Stankiewicz plot, qualitative-quantitative analysis, stability cross plot, Heithaus parameter, toluene equivalence, Bureau of Mines correlation index – toluene equivalence, and oil compatibility model are reported in this work. In addition, SARA fractionation, asphaltene...
A diesel engine with 6-cylinder, turbocharged intercooling and common rail system was modified to operate on diesel/methanol dual fuel (DMDF). To optimize combustion process at high methanol substitution ratio (MSR) and further decrease exhaust emissions of DMDF engine at low load condition, pilot injection strategy was applied on it and the combustion, regulated and unregulated gaseous emission (included...
The vapor-liquid water-hydrate (V-Lw-H) phase equilibria are essential for multiple processes involving methane substitution by carbon dioxide. This work developed a model to predict the multiphase equilibria of CH4CO2H2O systems using molecule-based statistical association fluid theory (SAFT2) equation of states for the vapor and liquid phases and the statistical model by van der Waals-Platteeuw...
The moisture content (MC) of a fuel is generally determined through gravimetric analysis where a sample is dehydrated in an oven over a period of approximately 24h; the MC is then calculated by dividing the difference between the initial and final mass, by the initial mass. Handheld moisture meters offer the benefit of near-instantaneous measurements and should provide accurate and dependable results...
In this study, co-gasification of coal and biomass chars with CO2 in the presence of CO was investigated at three different temperatures: 850, 875, and 900°C. A coal–biomass (bituminous-pineapple sawdust) mixture with a mass ratio of 1:1 was used for devolatilization and co-gasification. Random pore model was employed to determine the kinetic coefficient from experimentally obtained carbon conversion...
It is well known that premixed and non-premixed flamelets coexist in the combustion system, especially for multiphase combustion (Luo et al., 2011; Bai et al., 2016). In this work, a multi-regime combustion model for partially premixed multiphase combustion (2PMC) is developed in the framework of large eddy simulation (LES). In this model, the multi-regime combustion mode is decomposed into two pure...
For the purpose of producing biocrude from pretreated and washed sweet sorghum bagasse, hydrothermal liquefaction (HTL) was conducted with six different catalysts at two temperatures. The six catalysts were: K2CO3, KOH, formic acid, Ni/SiAl, Ni2P and zeolite. The two temperatures were 300 and 350°C. Based on two selection criteria, high yield of biocrude and low yield of biochar, K2CO3, KOH, and Ni/SiAl...
A poro-elasticity reservoir simulation model was developed to analyze the huff-n-puff operations in the Fuyu continental tight oil layer. The model was based on the “two-way” coupling of a geomechanical model and a compositional model. The pressures induced from the compositional model were set as input for the geomechanical model, and the effective stresses calculated from the geomechanical model...
In coal-bed methane (CBM) reservoirs, gas is mainly stored in matrix as adsorbed gas and the cleats are commonly saturated with water. To produce the adsorbed gas, the cleat pressure should be reduced to critical desorption pressure by dewatering first. But how to dewater more efficiently is a difficult issue. Apparently low dewatering rate is uneconomical due to excessive development times required...
Libraries of kinetic hydrate inhibitors (KHIs) based on poly(N-isopropylacrylamide) (PNIPAM) were synthesized by post-synthetic modification of an existing PNIPAM copolymer. Unlike other synthetic routes this generates accurately controlled libraries of KHIs with similar molecular weight (M‾w), molecular weight distribution, end groups and composition. This allows for accurate interpretation of the...
Hierarchical TS-1 (HTS-1) zeolite has been successfully synthesized through a novel three-step crystallization method by using a cheap and eco-friendly polymer PVA as the mesopore template. The HTS-1 particles possess an interesting stacking structure and are constructed of smaller crystals with an average diameter of 30nm. The mesopores of HTS-1 are formed by the stacking of the smaller TS-1 nanocrystals...
This paper presents numerical and experimental analysis of diesel engine spray dynamics in the region very close to the nozzle exit. Diesel fuel is injected through a single solid cone injector with sharp-edged nozzle inlet. Numerical investigations are conducted in an Eulerian framework by applying a Volume of Fluid interface capturing technique integrated with Large-Eddy Simulation turbulence modelling...
To achieve economic viability, biorefineries need to increase efficiency through characterization of byproducts for the purpose of valorization. One such byproduct is the liquid stream produced after autohydrolysis pretreatment, autohydrolyzate liquor, which contains valuable organic derivatives of hemicellulose and lignin from biomass. To characterize the autohydrolysis liquor, we employed a novel...
This study presents an experimental investigation of the ignition and combustion characteristics of single biomass pellets in air and O2/CO2 atmospheres containing 21%, 30%, 40%, 50% and 100% oxygen mole fractions. In this experiment, the temperature of the gas surrounding the biomass pellets was set respectively at 873K, 973K and 1073K. The rate of co-flow gas was set at 10L/min, 15L/min and 20L/min...
Based on previous experimental adsorption kinetic and equilibrium data for mercuric chloride (HgCl2) adsorption onto raw activated carbon (AC), a comprehensive model was formulated for its removal in the ductwork and fabric filter by raw AC injection in coal combustion flue gas. Various factors that can impact the performance and sorbent utilization were investigated, including inlet HgCl2 concentration,...
Free-piston engine generator (FPEG) is an unconventional engine; which is characterized by freely moving pistons without crankshaft system. This paper focused on an experimental analysis for the combustion and heat release characteristics of a free-piston diesel engine generator. An experimental prototype was established to test the operation performances of the new engine under different injection...
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