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An optimized design for hydraulic fracturing is of great importance especially with the growing demand for this method as a means of production enhancement from unconventional gas reservoirs. The first Optimum Fracture Design (OFD) approach, which maximizes well productivity for a given fracture volume, was introduced by Prats in 1960 for single-phase Darcy flow systems. This was then further developed...
The objective of this work is to optimize direct injection, single cylinder diesel engine with respect to brake power, fuel economy and smoke emissions through experimental investigation and response surface methodology. A single cylinder 3.8kW engine was selected for this experimentation. Three parameters viz. compression ratio (CR), injection pressure (IP) and injection timing (IT) were varied and...
The general purpose of this work is to evaluate the relationship between the fuel quality and the gaseous and particulate matter (PM) emissions in a domestic boiler fired with five different types of pellets, namely, two commercial pellets from pine residues, commercial pellets from cork residues, and in-house made pellets from olive wood and olive pruning residues. Initially, to evaluate if the pellets...
A Brønsted solid acid was prepared from waste coal fly ash by acid treatment with concentrated H 2 SO 4 at 473K. The prepared solid acid was characterized by X-ray diffraction (XRD), Fourier-transform Infrared spectra (FT-IR), solid-state nuclear magnetic resonance (NMR) and scanning electron microscope (SEM). The characterization results show that the solid acid contains two types...
Regardless of the emergent use of fluorescence as an analytical method to investigate biodiesel no detailed discussion about the origin of the visible fluorescence in different biodiesel samples has been reported. Here, UV–Vis absorption and fluorescence analysis of biodiesels (soybean, corn, canola, and sunflower), standard methyl esters (stearate, palmitate, oleate, linoleate and linolenate), phenolic...
The reaction mechanism of the acid-catalyzed transesterification of butyric acid monoglyceride was studied employing Density Functional Theory (DFT). Solvent effects were included by means of the integral equation formalism for the polarizable continuum model (IEFPCM). It was found that both in the gas phase and in solution the reaction proceeds through a concerted mechanism with a single transition...
The objective of this study is to measure apparent rate parameters for pinewood char gasification with CO 2 using large particles with relevance to practical gasifiers. The novel features of this work include: (1) char gasification for CO 2 recycling, which is studied less in the past than char gasification in other environments, (2) independent measurements involving gravimetric analyses...
The interactions between vitrinite and inertinite-rich coals and the ionic liquid butylimidazolium chloride ([bmim][Cl]) heated to 100°C have been characterised. Differences in the interactions of coal macerals and ionic liquids have been identified. [bmim][Cl] is able to dissolve 22wt% of a high-vitrinite coal fraction compared to 14wt% of a high-inertinite coal fraction. The vitrinite-rich coal...
A model based on the framework of possibility density function (PDF) was used to simulate the sub-grid scale eddies “seen” by the droplets in an evaporating isopropyl alcohol spray. LES was used to simulate the fluid flow. The motion and evaporation of the droplets were solved in Lagrangian method and the filtered density function (FDF) transport equation was adopted to solve the sub-grid scale velocity...
We report a detailed compositional characterization of a bio-crude oil and aqueous by-product from hydrothermal liquefaction of Nannochloropsis salina by direct infusion Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) in both positive- and negative-ionization modes. The FT-ICR MS instrumentation approach facilitates direct assignment of elemental composition to >7000 resolved...
Heavy oil and bitumen resources will need to be exploited to supplement depleting conventional oils worldwide as they gradually approach their peak production in the forthcoming decades. However, the physico-chemical characteristics of heavy oil and bitumen include high density, low distillates fraction, high viscosity, and high hetero-atom content which make extraction difficult and relatively expensive...
Magmatic intrusion into coal-bearing sequences can significantly affect the rank of the intruded coal and change the macromolecular and pore structures. Here, we use Raman microscope and Atomic force microscope (AFM) to obtain quantitative information on these transformations. Six coal samples of different ranks taken from a magmatic intrusion zone of Huainan Coalfield, China, were studied. The Raman...
Coal-fired boilers often develop massive fouling and slagging deposits on heat transfer surfaces in areas where coal ash particles have relatively high viscosities (⩾10 6 Pas). In order to investigate the characteristics and mechanism of the problems, experiments were performed in a drop tube furnace and by use of a slagging probe in this study. The results showed that fouling deposits developed...
Rare earth elements have been identified by the European Commission as a critical raw material. Six European coal fly ashes have been investigated for their rare earth element content. A coal fly ash from the UK has levels of rare earth element that are approaching that which might be commercially viable to exploit. After classification there was found to be a slight enrichment in the smaller non-magnetic...
Effect of Karanja biodiesel (Karanja oil methyl ester; KOME) and its blends on engine performance, emissions and combustion characteristics in a direct injection compression ignition (DICI) engine of a medium size utility vehicle with varying engine speed and load has been investigated. Maximum torque attained by 10% and 20% KOME blends were higher than mineral diesel, while higher biodiesel blends...
A series of ternary hydrotalcites in the nitrate form was prepared with a modified-urea method to obtain active Co-based catalysts for the Fischer–Tropsch synthesis. An optimization study concerning the amount of cobalt in the catalysts (range 5–35wt%.) and the reaction temperature (220–260°C) is reported. All the samples were characterized by several methods, including XRPD, ICP-OES, SEM, TEM, FT-IR,...
Intensive development of the transport sector and a rise in the prices of fossil fuels boost the demand for fuels from alternative sources of energy, including biofuels. New energy-efficient technologies of fuel production from renewable resources are developed. The aim of the present study was to examine the factors influencing the effectiveness of the process of simultaneous saccharification and...
Different amounts of low-density polyethylene (LDPE) were added to a bituminous coal used to produce metallurgical coke. The effect of the plastic waste on the carbonization process and more exactly, on the coking pressure were investigated. A movable wall oven at semi-pilot scale was used for measuring coking pressure generated. It was found that coking pressure increases for low LDPE addition levels...
Red mud which enriched with various metal oxides was impregnated into oil palm biomass-empty fruit bunch (EFB) to study its effect on pyrolysis product. During impregnation, most of the biomass inherent minerals (mainly K, Ca and Mg) were removed and simultaneously red mud compounds (mainly Fe, Al and Ti) were impregnated into EFB. Biomass impregnation of red mud derived compounds was enhanced by...
This work presents a facile and rapid approach for the preparation of graphene sheet (GS) decorated by nanometer scaled molybdenum disulfide (MoS 2 ) with effective hydrodesulfurization activity for carbonyl sulfide conversion at low temperature (<300°C). Using functionalized GS as microwave susceptor and ammonium tetrathiomolybdate as the precursor of MoS 2 , nanocomposites consisting...
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