Abstract: The objective of this research is to study the technical
and economic performance of wind/diesel/battery (W/D/B) system
supplying a remote small gathering of six families using HOMER
software package. The electrical energy is to cater for the basic needs
for which the daily load pattern is estimated. Net Present Cost (NPC)
and Cost of Energy (COE) are used as economic criteria, while the measure of performance is % of power shortage. Technical and
economic parameters are defined to estimate the feasibility of the
system under study. Optimum system configurations are estimated for two sites. Using HOMER software, the simulation results showed that W/D/B systems are economical for the assumed community sites
as the price of generated electricity is about 0.308 $/kWh, without
taking external benefits into considerations. W/D/B systems are more
economical than W/B or diesel alone systems, as the COE is 0.86 $/kWh for W/B and 0.357 $/kWh for diesel alone.
Abstract: The increasing industrialization and motorization of the world has led to a steep rise for the demand of petroleum-based fuels. Petroleum-based fuels are obtained from limited reserves. These finite reserves are highly concentrated in certain regions of the world. Therefore, those countries not having these resources are facing energy/foreign exchange crisis, mainly due to the import of crude petroleum. Hence, it is necessary to look for alternative fuels which can be produced from resources available locally within the country such as alcohol, biodiesel, vegetable oils etc. Biodiesel is a renewable, domestically produced fuel that has been shown to reduce particulate, hydrocarbon, and carbon monoxide emissions from combustion. In the present study an experimental investigation on emission characteristic of a liquid burner system operating on several percentage of biodiesel and gas oil is carried out. Samples of exhaust gas are analysed with Testo 350 Xl. The results show that biodiesel can lower some pollutant such as CO, CO2 and particulate matter emissions while NOx emission would increase in comparison with gas oil. The results indicate there may be benefits to using biodiesel in industrial processes.
Abstract: Chicken fat was employed as a feedstock for
producing of biodiesel by trasesterification reaction with methanol
and alkali catalyst (KOH). In this study chicken fat biodiesel with
1.4% free fatty acid, methanol and various amount of potassium
hydroxide for 2 hour were studied. The progression of reaction and
conversion of triglycerides to methyl ester were checked by IR
spectrum method.
Abstract: In this study, effects of premixed and equivalence
ratios on CO and HC emissions of a dual fuel HCCI engine are
investigated. Tests were conducted on a single-cylinder engine with
compression ratio of 17.5. Premixed gasoline is provided by a
carburetor connected to intake manifold and equipped with a screw
to adjust premixed air-fuel ratio, and diesel fuel is injected directly
into the cylinder through an injector at pressure of 250 bars. A heater
placed at inlet manifold is used to control the intake charge
temperature. Optimal intake charge temperature results in better
HCCI combustion due to formation of a homogeneous mixture,
therefore, all tests were carried out over the optimum intake
temperature of 110-115 ºC. Timing of diesel fuel injection has a great
effect on stratification of in-cylinder charge and plays an important
role in HCCI combustion phasing. Experiments indicated 35 BTDC
as the optimum injection timing. Varying the coolant temperature in
a range of 40 to 70 ºC, better HCCI combustion was achieved at 50
ºC. Therefore, coolant temperature was maintained 50 ºC during all
tests. Simultaneous investigation of effective parameters on HCCI
combustion was conducted to determine optimum parameters
resulting in fast transition to HCCI combustion. One of the
advantages of the method studied in this study is feasibility of easy
and fast transition of typical diesel engine to a dual fuel HCCI
engine. Results show that increasing premixed ratio, while keeping
EGR rate constant, increases unburned hydrocarbon (UHC)
emissions due to quenching phenomena and trapping of premixed
fuel in crevices, but CO emission decreases due to increase in CO to
CO2 reactions.
Abstract: It is estimated that the total cost of abnormal
conditions to US process industries is around $20 billion dollars in
annual losses. The hydrotreatment (HDT) of diesel fuel in petroleum
refineries is a conversion process that leads to high profitable
economical returns. However, this is a difficult process to control
because it is operated continuously, with high hydrogen pressures
and it is also subject to disturbances in feed properties and catalyst
performance. So, the automatic detection of fault and diagnosis plays
an important role in this context. In this work, a hybrid approach
based on neural networks together with a pos-processing
classification algorithm is used to detect faults in a simulated HDT
unit. Nine classes (8 faults and the normal operation) were correctly
classified using the proposed approach in a maximum time of 5
minutes, based on on-line data process measurements.
Abstract: The reduction in vehicle exhaust emissions achieved
in the last two decades is offset by the growth in traffic, as well as by
changes in the composition of emitted pollutants. The present
investigation illustrates the emissions of in-use gasoline and diesel
passenger cars using the official European driving cycle and the
ARTEMIS real-world driving cycle. It was observed that some of the
vehicles do not comply with the corresponding regulations.
Significant differences in emissions were observed between driving
cycles. Not all pollutants showed a tendency to decrease from Euro 3
to Euro 5.
Abstract: The quest for alternatefuels for a CI engine has
become all the more imperative considering its importance in the
economy of a nation and from the standpoint of preserving the environment. Reported in this paper are the combustion performance and P-θ characteristics of a CI engine operating on B20 biodiesel fuel derived from Jatropha oil.Itis observed that the twin effect of advancing the injection timing and increasing the injector opening pressure (IOP) up to 220 barhas resulted in minimum brake specific
energy consumption and higherpeak pressure. It is also observed that
the crank angle of occurrence of peak pressure progressestowards top
dead center (TDC) as the timing is advanced and IOP is increased.
Abstract: With the growth of modern civilization and
industrialization in worldwide, the demand for energy is increasing
day by day. Majority of the world-s energy needs are met through
fossil fuels and natural gas. As a result the amount of fossil fuels is
on diminishing from year to year. Since the fossil fuel is nonrenewable,
so fuel price is gouging as a consequence of spiraling
demand and diminishing supply. At present the power generation of
our country is mainly depends on imported fossil fuels. To reduce the
dependency on imported fuel, the use of renewable sources has
become more popular. In Bangladesh coconut is widely growing tree.
Especially in the southern part of the country a large area will be
found where coconut tree is considered as natural asset. So, our
endeavor was to use the coconut oil as a renewable and alternative
fuel. This article shows the prospect of coconut oil as a renewable
and alternative fuel of diesel fuel. Since diesel engine has a versatile
uses including small electricity generation, an experimental set up is
then made to study the performance of a small diesel engine using
different blends of bio diesel converted from coconut oil. It is found
that bio diesel has slightly different properties than diesel. With
biodiesel the engine is capable of running without difficulty.
Different blends of bio diesel (i.e. B80, B60, and B 50 etc.) have
been used to avoid complicated modification of the engine or the fuel
supply system. Finally, a comparison of engine performance for
different blends of biodiesel has been carried out to determine the
optimum blend for different operating conditions.
Abstract: The composition, vapour pressure, and heat capacity
of nine biodiesel fuels from different sources were measured. The
vapour pressure of the biodiesel fuels is modeled assuming an ideal
liquid phase of the fatty acid methyl esters constituting the fuel. New
methodologies to calculate the vapour pressure and ideal gas and
liquid heat capacities of the biodiesel fuel constituents are proposed.
Two alternative optimization scenarios are evaluated: 1) vapour
pressure only; 2) vapour pressure constrained with liquid heat
capacity. Without physical constraints, significant errors in liquid
heat capacity predictions were found whereas the constrained
correlation accurately fit both vapour pressure and liquid heat
capacity.
Abstract: The present energy situation and the concerns
about global warming has stimulated active research interest
in non-petroleum, carbon free compounds and non-polluting
fuels, particularly for transportation, power generation, and
agricultural sectors. Environmental concerns and limited
amount of petroleum fuels have caused interests in the
development of alternative fuels for internal combustion (IC)
engines. The petroleum crude reserves however, are declining
and consumption of transport fuels particularly in the
developing countries is increasing at high rates. Severe
shortage of liquid fuels derived from petroleum may be faced
in the second half of this century. Recently more and more
stringent environmental regulations being enacted in the USA
and Europe have led to the research and development
activities on clean alternative fuels. Among the gaseous fuels
hydrogen is considered to be one of the clean alternative fuel.
Hydrogen is an interesting candidate for future internal
combustion engine based power trains. In this experimental
investigation, the performance and combustion analysis were
carried out on a direct injection (DI) diesel engine using
hydrogen with diesel following the TMI(Time Manifold
Injection) technique at different injection timings of 10
degree,45 degree and 80 degree ATDC using an electronic
control unit (ECU) and injection durations were controlled.
Further, the tests have been carried out at a constant speed of
1500rpm at different load conditions and it can be observed
that brake thermal efficiency increases with increase in load
conditions with a maximum gain of 15% at full load
conditions during all injection strategies of hydrogen. It was
also observed that with the increase in hydrogen energy share
BSEC started reducing and it reduced to a maximum of 9% as
compared to baseline diesel at 10deg ATDC injection during
maximum injection proving the exceptional combustion
properties of hydrogen.
Abstract: The objective of this work is to produce heterotrophic
microalgal lipid in flask-batch fermentation. Chlorella sp. KKU-S2
supported maximum values of 0.374 g/L/d, 0.478 g lipid/g cells, and
0.112 g/L/d for volumetric lipid production rate, and specific yield of
lipid, and specific rate of lipid production, respectively when culture
was performed on BG-11 medium supplemented with 50g/L glucose.
Among the carbon sources tested, maximum cell yield coefficient
(YX/S, g/L), maximum specific yield of lipid (YP/X, g lipid/g cells) and
volumetric lipid production rate (QP, g/L/d) were found of 0.728,
0.237, and 0.619, respectively, using sugarcane molasses as carbon
source. The main components of fatty acid from extracted lipid were
palmitic acid, stearic acid, oleic acid and linoleic acid which similar
to vegetable oils and suitable for biodiesel production.
Abstract: Biodiesel production results in glycerol production as
the main by-product in biodiesel industry.One of the utilizations of
glycerol obtained from biodiesel production is as a cement grinding
aid (CGA). Results showed that crude glycerol content was 40.19%
whereas pure glycerol content was 82.15%. BSS value of the cement
with CGA supplementation was higher than that of nonsupplemented
cement (blank) indicating that CGA-supplemented
cement had higher fineness than the non-supplemented one. It was
also found that pure glycerol 95% and TEA 5% at 80ºC was the
optimum CGA used to result in finest cement with BSS value of
4.836 cm2/g. Residue test showed that the smallest percent residue
value (0.11%) was obtained in cement with supplementation of pure
glycerol 95% and TEA 5%. Results of residue test confirmed those of
BSS test showing that cement with supplementation of pure glycerol
95% and TEA 5% had the finest particle size.
Abstract: A zero dimensional model has been used to investigate
the combustion performance of a single cylinder direct injection
diesel engine fueled by biofuels with options like supercharging and
exhaust gas recirculation. The numerical simulation was performed at
constant speed. The indicated pressure, temperature diagrams are
plotted and compared for different fuels. The emissions of soot and
nitrous oxide are computed with phenomenological models. The
experimental work was also carried out with biodiesel (palm stearin
methyl ester) diesel blends, ethanol diesel blends to validate
simulation results with experimental results, and observed that the
present model is successful in predicting the engine performance with
biofuels.
Abstract: In a bi-fuel diesel engine, the carburetor plays a vital
role in switching from fuel gas to petrol mode operation and viceversa.
The carburetor is the most important part of the fuel system of
a diesel engine. All diesel engines carry variable venturi mixer
carburetors. The basic operation of the carburetor mainly depends on
the restriction barrel called the venturi. When air flows through the
venturi, its speed increases and its pressure decreases. The main
challenge focuses on designing a mixing device which mixes the
supplied gas is the incoming air at an optimum ratio. In order to
surmount the identified problems, the way fuel gas and air flow in
the mixer have to be analyzed. In this case, the Computational Fluid
Dynamics or CFD approach is applied in design of the prototype
mixer. The present work is aimed at further understanding of the air
and fuel flow structure by performing CFD studies using a software
code. In this study for mixing air and gas in the condition that has
been mentioned in continuance, some mixers have been designed.
Then using of computational fluid dynamics, the optimum mixer has
been selected. The results indicated that mixer with 12 holes can
produce a homogenous mixture than those of 8-holes and 6-holes
mixer. Also the result showed that if inlet convergency was smoother
than outlet divergency, the mixture get more homogenous, the reason
of that is in increasing turbulence in outlet divergency.
Abstract: TiO2 supported nano-ZnO catalyst was prepared by
deposition-precipitation and tested for the trans-esterification
reaction of soybean oil to biodiesel. The TiO2 support stabilized the
nano-ZnO in a dispersed form with limited crystallite size compared
to the unsupported ZnO. The final ZnO dispersion and crystallite size
and the material transfer resistance in the catalyst significantly
influenced the supported nano-ZnO catalyst performance.
Abstract: The daily increase of organic waste materials resulting
from different activities in the country is one of the main factors for
the pollution of environment. Today, with regard to the low level of
the output of using traditional methods, the high cost of disposal
waste materials and environmental pollutions, the use of modern
methods such as anaerobic digestion for the production of biogas has
been prevailing. The collected biogas from the process of anaerobic
digestion, as a renewable energy source similar to natural gas but
with a less methane and heating value is usable. Today, with the help
of technologies of filtration and proper preparation, access to biogas
with features fully similar to natural gas has become possible. At
present biogas is one of the main sources of supplying electrical and
thermal energy and also an appropriate option to be used in four
stroke engine, diesel engine, sterling engine, gas turbine, gas micro
turbine and fuel cell to produce electricity. The use of biogas for
different reasons which returns to socio-economic and environmental
advantages has been noticed in CHP for the production of energy in
the world. The production of biogas from the technology of anaerobic
digestion and its application in CHP power plants in Iran can not only
supply part of the energy demands in the country, but it can
materialize moving in line with the sustainable development. In this
article, the necessity of the development of CHP plants with biogas
fuels in the country will be dealt based on studies performed from the
economic, environmental and social aspects. Also to prove the
importance of the establishment of these kinds of power plants from
the economic point of view, necessary calculations has been done as
a case study for a CHP power plant with a biogas fuel.
Abstract: Group contribution methods such as the UNIFAC are
of major interest to researchers and engineers involved synthesis,
feasibility studies, design and optimization of separation processes as
well as other applications of industrial use. Reliable knowledge of
the phase equilibrium behavior is crucial for the prediction of the fate
of the chemical in the environment and other applications. The
objective of this study was to predict the solubility of selected
volatile organic compounds (VOCs) in glycol polymers and
biodiesel. Measurements can be expensive and time consuming,
hence the need for thermodynamic models. The results obtained in
this study for the infinite dilution activity coefficients compare very
well those published in literature obtained through measurements. It
is suggested that in preliminary design or feasibility studies of
absorption systems for the abatement of volatile organic compounds,
prediction procedures should be implemented while accurate fluid
phase equilibrium data should be obtained from experiment.
Abstract: The present work describes an experimental
investigation concerning the determination of viscosity behavior with
shear rate and temperature of edible oils: canola; sunflower; corn;
soybean and the no edible oil: Jatropha curcas. Besides these, it was
tested a blend of canola, corn and sunflower oils as well as sunflower
and soybean biodiesel. Based on experiments, it was obtained shear
stress and viscosity at different shear rates of each sample at 40ºC, as
well as viscosity of each sample at various temperatures in the range
of 24 to 85ºC. Furthermore, it was compared the curves obtained for
the viscosity versus temperature with the curves obtained by
modeling the viscosity dependency on temperature using the Vogel
equation. Also a test in a stationary engine was performed in order to
study the energy generation using blends of soybean oil and soybean
biodiesel with diesel.
Abstract: Partial combustion of biomass in the gasifier generates producer gas that can be used for heating purposes and as supplementary or sole fuel in internal combustion engines. In this study, the virgin biomass obtained from hingan shell is used as the feedstock for gasifier to generate producer gas. The gasifier-engine system is operated on diesel and on esters of vegetable oil of hingan in liquid fuel mode operation and then on liquid fuel and producer gas combination in dual fuel mode operation. The performance and emission characteristics of the CI engine is analyzed by running the engine in liquid fuel mode operation and in dual fuel mode operation at different load conditions with respect to maximum diesel savings in the dual fuel mode operation. It was observed that specific energy consumption in the dual fuel mode of operation is found to be in the higher side at all load conditions. The brake thermal efficiency of the engine using diesel or hingan oil methyl ester (HOME) is higher than that of dual fuel mode operation. A diesel replacement in the tune of 60% in dual fuel mode is possible with the use of hingan shell producer gas. The emissions parameters such CO, HC, NOx, CO2 and smoke are higher in the case of dual fuel mode of operation as compared to that of liquid fuel mode.
Abstract: Although oil-based drilling fluids are of paramount practical and economical interest, they represent a serious source of pollution, once released into the environment as drill cuttings. The aim of this study is to assess the capability of isolated microorganisms to degrade gasoil fuel. The commonly used physicochemical and biodegradation remediation techniques of petroleum contaminated soil were both investigated. The study revealed that natural biodegradation is favorable. Even though, the presence of heavy metals, the moisture level of (8.55%) and nutrient deficiencies put severe constrains on microorganisms- survival ranges inhibiting the biodegradation process. The selected strains were able to degrade the diesel fuel at significantly high rates (around 98%).