Abstract: The demand of hydrocarbons has increased the
construction of pipelines and the protection of the physical and
mechanical integrity of the already existing infrastructure. Corrosion
is the main reason of failures in the pipeline and it is mostly produced
by acid (HCOOCH3). In this basis, a CFD code was used, in order to
study the corrosion of internal wall of hydrocarbons pipeline. In this
situation, the corrosion phenomenon shows a growing deposit, which
causes defect damages (welding or fabrication) at diverse positions
along the pipeline. The solution of the pipeline corrosion is based on
the diminution of the Naphthenic acid.
Abstract: Combustion, emission and performance
characterization of a single cylinder diesel engine using methanol
diesel blends was carried out. The blends were 5% (v/v) methanol in
diesel (MD05) and 10% (v/v) methanol in diesel (MD10). The
problem of solubility of methanol and diesel was addressed by an
agitator placed inside the fuel tank to prevent phase separation. The
results indicated that total combustion duration was reduced by15.8%
for MD05 and 31.27% for MD10compared to the baseline data.
Ignition delay was increased with increasing methanol volume
fraction in the test fuel. Total cyclic heat release was reduced by
1.5% for MD05 and 6.7% for MD10 as compared to diesel baseline.
Emissions of carbon monoxide, hydrocarbons along with smoke were
reduced and that of nitrogen oxides were increased with rising
methanol contents in the test fuel. Full load brake thermal efficiency
was marginally reduced with increased methanol composition in the
blend.
Abstract: Surface sediment samples were collected from the
Canon River mouth, Taiwan and analyzed for polycyclic aromatic
hydrocarbons (PAHs). Total PAHs concentrations varied from 337 to
1,252 ng/g dry weight, with a mean concentration of 827 ng/g dry
weight. The spatial distribution of PAHs reveals that the PAHs
concentration is relatively high in the river mouth region, and
gradually diminishes toward the harbor region. Diagnostic ratios
showed that the possible source of PAHs in the Canon River mouth
could be petroleum combustion. The toxic equivalent concentrations
(TEQcarc) of PAHs varied from 47 to 112 ng TEQ/g dry weight. Higher
total TEQcarc values were found in the river mouth region. As
compared with the US Sediment Quality Guidelines (SQGs), the
observed levels of PAHs at Canon River mouth were lower than the
effects range low (ERL), and would probably not exert adverse
biological effects.
Abstract: This work presents the experimental results obtained
at a pilot plant which works with a slow, wet and catalytic pyrolysis
process of dry fowl manure. This kind of process mainly consists in
the cracking of the organic matrix and in the following reaction of
carbon with water, which is either already contained in the organic
feed or added, to produce carbon monoxide and hydrogen. Reactions
are conducted in a rotating reactor maintained at a temperature of
500°C; the required amount of water is about 30% of the dry organic
feed. This operation yields a gas containing about 59% (on a volume
basis) of hydrogen, 17% of carbon monoxide and other products such
as light hydrocarbons (methane, ethane, propane) and carbon
monoxide in lesser amounts. The gas coming from the reactor can be
used to produce not only electricity, through internal combustion
engines, but also heat, through direct combustion in industrial
boilers. Furthermore, as the produced gas is devoid of both solid
particles and pollutant species (such as dioxins and furans), the
process (in this case applied to fowl manure) can be considered as an
optimal way for the disposal and the contemporary energetic
valorization of organic materials, in such a way that is not damaging
to the environment.
Abstract: Some of the polycyclic aromatic hydrocarbons (PAHs)
are the strongest known carcinogens compounds; the majority of
them are mostly produced by the incomplete combustion of fossil
fuels; Motor vehicles are a significant source of polycyclic aromatic
hydrocarbon (PAH) where diesel emission is one of the main sources
of such compounds available in the ambient air. There is a big
concern about the increasing concentration of PAHs in the
environment. Researchers are trying to explore optimal methods to
reduce those pollutants and improve the quality of air. Water blended
fuel is one of the possible approaches to reduce emission of PAHs
from the combustion of diesel in urban and domestic vehicles. In this
work a modeling study was conducted using CHEMKIN-PRO
software to simulate spray combustion at similar diesel engine
conditions. Surrogate fuel of (80 % n-heptane and 20 % toluene) was
used due to detailed kinetic and thermodynamic data needed for
modeling is available for this kind of fuel but not available for diesel.
An emulsified fuel with 3, 5, 8, 10 and 20 % water by volume is used
as an engine feed for this study. The modeling results show that water
has a significant effect on reducing engine soot and PAHs precursors
formation up to certain extent.
Abstract: This work focuses on the remediation of polycyclic
aromatic hydrocarbons (PAHs)-contaminated soil via Fenton
treatment coupled with novel chelating agent (CA). The feasibility of
chelated modified Fenton (MF) treatment to promote PAH oxidation
in artificially contaminated soils was investigated in laboratory scale
batch experiments at natural pH. The effects of adding inorganic and
organic CA are discussed. Experiments using different iron catalyst
to CA ratios were conducted, resulting in hydrogen peroxide: soil:
iron: CA weight ratios that varied from 0.049: 1: 0.072: 0.008 to
0.049: 1: 0.072: 0.067. The results revealed that (1) inorganic CA
could provide much higher PAH removal efficiency and (2) most of
the proposed CAs were more efficient than commonly utilised CAs
even at mild ratio. This work highlights the potential of novel
chelating agents in maintaining a suitable environment throughout
the Fenton treatment, particularly in soils with high buffer capacity.
Abstract: As the demand and prices of various petroleum products have been on the rise in recent years, there is a growing need for alternative fuels. Biodiesel, which consists of alkyl monoesters of fatty acids from vegetable oils and animal fats, is considered as an alternative to petroleum diesel. Biodiesel has comparable performance with that of diesel and has lower brake specific fuel consumption than diesel with significant reduction in emissions of CO, hydrocarbons (HC) and smoke with however, a slight increase in NOx emissions. This paper analyzes the effect of cooled exhaust gas recirculation in the combustion characteristics of a direct injection compression ignition engine using biodiesel blended fuel as opposed to the conventional system. The combustion parameters such as cylinder pressure, heat release rate, delay period and peak pressure were analyzed at various loads. The maximum cylinder pressure reduces as the fraction of biodiesel increases in the blend the maximum rate of pressure rise was found to be higher for diesel at higher engine loads.
Abstract: The implementation of Super-Ultra Low Emission
Vehicle standards requires more efficient exhaust gas purification. To
increase the efficiency of exhaust gas purification, an the adsorbent
capable of holding hydrocarbons up to 250-300 ОС should be
developed. The possibility to design such adsorbents by modification
of zeolites of mordenite type, ZSM-5 and NaY, using different
metals cations has been studied.
It has been shown that introducing Cr, Cs, Zn, Ni, Co, Li, Mn in
zeolites results in modification of the toluene TPD and toluene
sorption capacity.
5%LiZSM-5 zeolite exhibits the most attractive TPD curve, with
toluene desorption temperature ranging from 250 to 350ОС. The
sorption capacity of 5%Li-ZSM-5 is 0.4 mmol/g. NaY zeolite has the
highest sorption capacity, up to 2 mmol/g, and holds toluene up to
350ОС, but at 120ОС toluene desorption starts, which is not desirable,
since the adsorbent of cold start hydrocarbons should retain them
until 250-300ОС. Therefore 5%LiZSM-5 zeolite was found to be the
most promising to control the cold-start hydrocarbon emissions
among the samples studied.
Abstract: There is growing interest in biodiesel (fatty acid
methyl ester or FAME) because of the similarity in its properties
when compared to those of diesel fuels. Diesel engines operated on
biodiesel have lower emissions of carbon monoxide, unburned
hydrocarbons, particulate matter, and air toxics than when operated
on petroleum-based diesel fuel. Production of fatty acid methyl ester
(FAME) from rapeseed (nonedible oil) fatty acid distillate having
high free fatty acids (FFA) was investigated in this work. Conditions
for esterification process of rapeseed oil were 1.8 % H2SO4 as
catalyst, MeOH/oil of molar ratio 2 : 0.1 and reaction temperature
65 °C, for a period of 3h. The yield of methyl ester was > 90 % in 1
h.
The amount of FFA was reduced from 93 wt % to less than 2 wt %
at the end of the esterification process. The FAME was pureed by
neutralization with 1 M sodium hydroxide in water solution at a
reaction temperature of 62 °C. The final FAME product met with the
biodiesel quality standard, and ASTM D 6751.
Abstract: Solid oxide fuel cells have been considered in the last years as one of the most promising technologies for very highefficiency electric energy generation from hydrogen or other hydrocarbons, both with simple fuel cell plants and with integrated gas turbine-fuel cell systems. In the present study, a detailed thermodynamic analysis has been carried out. Mass and exergy balances are performed not only for the whole plant but also for each component in order to evaluate the thermal efficiency of combined cycle. Moreover, different sources of irreversibilities within the SOFC stack have been discussed and a parametric study conducted to evaluate the effect of temperature as well as pressure on SOFC irreversibilities and its performance. In this investigation methane and hydrogen have been used for fueling the SOFC stack and combustion chamber.
Abstract: Partial oxidation (POX) of light hydrocarbons (e.g.
methane) is occurred in the first part of the autothermal reformer
(ATR). The results of the detailed modeling of the reformer based on
the thermodynamic model of the POX and 1D heterogeneous
catalytic model for the fixed bed section are considered here.
According to the results, the overall performance of the ATR can be
improved by changing the important feed parameters.
Abstract: Fischer-Tropsch synthesis is one of the most
important catalytic reactions that convert the synthetic gas to light
and heavy hydrocarbons. One of the main issues is selecting the type
of reactor. The slurry bubble reactor is suitable choice for Fischer-
Tropsch synthesis because of its good qualification to transfer heat
and mass, high durability of catalyst, low cost maintenance and
repair. The more common catalysts for Fischer-Tropsch synthesis are
Iron-based and Cobalt-based catalysts, the advantage of these
catalysts on each other depends on which type of hydrocarbons we
desire to produce. In this study, Fischer-Tropsch synthesis is modeled
with Iron and Cobalt catalysts in a slurry bubble reactor considering
mass and momentum balance and the hydrodynamic relations effect
on the reactor behavior. Profiles of reactant conversion and reactant
concentration in gas and liquid phases were determined as the
functions of residence time in the reactor. The effects of temperature,
pressure, liquid velocity, reactor diameter, catalyst diameter, gasliquid
and liquid-solid mass transfer coefficients and kinetic
coefficients on the reactant conversion have been studied. With 5%
increase of liquid velocity (with Iron catalyst), H2 conversions
increase about 6% and CO conversion increase about 4%, With 8%
increase of liquid velocity (with Cobalt catalyst), H2 conversions
increase about 26% and CO conversion increase about 4%. With
20% increase of gas-liquid mass transfer coefficient (with Iron
catalyst), H2 conversions increase about 12% and CO conversion
increase about 10% and with Cobalt catalyst H2 conversions increase
about 10% and CO conversion increase about 6%. Results show that
the process is sensitive to gas-liquid mass transfer coefficient and
optimum condition operation occurs in maximum possible liquid
velocity. This velocity must be more than minimum fluidization
velocity and less than terminal velocity in such a way that avoid
catalysts particles from leaving the fluidized bed.
Abstract: The hydrogen peroxide treatment was able to
remediate chlorophenols, polycyclic aromatic hydrocarbons, diesel
and transformer oil contaminated soil. Chemical treatment of
contaminants adsorbed in peat resulted in lower contaminants-
removal and required higher addition of chemicals than the treatment
of contaminants in sand. The hydrogen peroxide treatment was found
to be feasible for soil remediation at natural soil pH. Contaminants in
soil could degrade with the addition of hydrogen peroxide only
indicating the ability of transition metals ions and minerals of these
metals presented in soil to catalyse the reaction of hydrogen peroxide
decomposition.
Abstract: Hydrogenated biodiesel is one of the most promising
renewable fuels. It has many advantages over conventional biodiesel,
including higher cetane number, higher heating value, lower
viscosity, and lower corrosiveness due to its absence of oxygen.
From previous work, Pd/TiO2 gave high conversion and selectivity in
hydrogenated biodiesel. In this work, the effect of biomass feedstocks
(i.e. beef fat, chicken fat, pork fat, and jatropha oil) on the production
of hydrogenated biodiesel over Pd/TiO2 has been studied. Biomass
feedstocks were analyzed by ICP-OES (inductively coupled plasma
optical emission spectrometry) to identify the content of impurities
(i.e. P, K, Ca, Na, and Mg). The deoxygenation catalyst, Pd/TiO2,
was prepared by incipient wetness impregnation (IWI) and tested in a
continuous flow packed-bed reactor at 500 psig, 325°C, H2/feed
molar ratio of 30, and LHSV of 4 h-1 for its catalytic activity and
selectivity in hydrodeoxygenation. All feedstocks gave high
selectivity in diesel specification range hydrocarbons and the main
hydrocarbons were n-pentadecane (n-C15) and n-heptadecane (n-
C17), resulting from the decarbonylation/decarboxylation reaction.
Intermediates such as oleic acid, stearic acid, palmitic acid, and esters
were also detected in minor amount. The conversion of triglycerides
in jatropha oil is higher than those of chicken fat, pork fat, and beef
fat, respectively. The higher concentration of metal impurities in
feedstock, the lower conversion of feedstock.
Abstract: The steam cracking reactions are always accompanied with the formation of coke which deposits on the walls of the tubular reactors. The investigation has attempted to control catalytic coking by the applying aluminum, zinc and ceramic coating like aluminum-magnesium by thermal spray and pack cementation method. Rate of coke formation during steam cracking of naphtha has been investigated both for uncoated stainless steel (with different alloys) and metal coating constructed with thermal Spray and pack cementation method with metal powders of Aluminum, Aluminum-Magnesium, zinc, silicon, nickel and chromium. The results of the study show that passivating the surface of SS321 with a coating of Aluminum and Aluminum-Magnesium can significantly reduce the rate of coke deposition during naphtha pyrolysis. SEM and EDAX techniques (Philips XL Series) were used to examine the coke deposits formed by the metal-hydrocarbon reactions. Our objective was to separate the different stages by identifying the characteristic morphologies.
Abstract: Environmental contamination is a common problem in ex-industrial and industrial sites. This article gives a brief description of general applied environmental investigation methodologies and possible remediation applications in Latvia. Most of contaminated areas are situated in former and active industrial, military areas and ports. Industrial and logistic activities very often have been with great impact for more than hundred years thus the contamination level with heavy metals, hydrocarbons, pesticides, persistent organic pollutants is high and is threatening health and environment in general. 242 territories now are numbered as contaminated and fixed in the National Register of contaminated territories in Latvia. Research and remediation of contamination in densely populated areas are of important environmental policy domain. Four different investigation case studies of contaminated areas are given describing the history of use, environmental quality assessment as well as planned environmental management actions. All four case study locations are situated in Riga - the capital of the Republic of Latvia. The aim of this paper is to analyze the situation and problems with management of contaminated areas in Latvia, give description of field research methods and recommendations for remediation industry based on scientific data and innovations.
Abstract: Theobjective of this study was to evaluate the optimal
treatment condition of Fenton oxidation process to removal
contaminant in soil slurry contaminated by petroleum hydrocarbons.
This research studied somefactors that affect the removal efficiency
of petroleum hydrocarbons in soil slurry including molar ratio of
hydrogen peroxide (H2O2) to ferrous ion(Fe2+), pH condition and
reaction time.The resultsdemonstrated that the optimum condition
was that the molar ratio of H2O2:Fe3+ was 200:1,the pHwas 4.0and
the rate of reaction was increasing rapidly from starting point to 7th
hour and destruction kinetic rate (k) was 0.24 h-1. Approximately
96% of petroleum hydrocarbon was observed(initialtotal petroleum
hydrocarbon (TPH) concentration = 70±7gkg-1)
Abstract: Borate minerals have attracted considerable attention in the past years due to their structural chemistry and mechanical properties in several industries. Recently, increasing attention has been paid to the use of; synthetically produced magnesium borates as catalysts reinforcing material for plastics, the conversion of hydrocarbons, electro-conductive treating agent, anti-wear and anti-corrosion materials. Magnesium borates can be synthesized by several methods such as; hydrothermal and solid-state (thermal) processes. In this study the hydrothermal production method was applied at the modest temperature of 80C along with convenient crystal growth. Using MgCl2.6H2O, H3BO3, and NaOH as starting materials, 30, 60, 120, 240 minutes of reaction times were studied. After all, the crystal structure and the morphology of the products were examined by X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). As a result the forms of Admontite and Mcallisterite minerals were synthesized.
Abstract: The pollution of sediments sampled from the North
Port by polycyclic aromatic hydrocarbons (PAHs) was investigated.
Concentrations of PAHs estimated in the port sediments ranged from
199 to 2851.2 μg/kg dw. The highest concentration was found which
is closed to the Berth line, this locations affected by intensive
shipping activities and Land based runoff and they were dominated
by the high molecular weight PAHs (4–6- rings). Source
identification showed that PAHs originated mostly from the
pyrogenic source either from the combustion of fossil fuels, grass,
wood and coal (majority of the samples). Ecological Risk Assessment
on the port sediments presented that slightly adverse ecological
effects to biological community are expected to occur at the vicinity
of the stations 1 and 4. Thus PAHs are not considered as pollutants of
concern in the North Port.
Abstract: Transesterified vegetable oils (biodiesel) are promising alternative fuel for diesel engines. Used vegetable oils are disposed from restaurants in large quantities. But higher viscosity restricts their direct use in diesel engines. In this study, used cooking oil was dehydrated and then transesterified using an alkaline catalyst. The combustion, performance and emission characteristics of Used Cooking oil Methyl Ester (UCME) and its blends with diesel oil are analysed in a direct injection C.I. engine. The fuel properties and the combustion characteristics of UCME are found to be similar to those of diesel. A minor decrease in thermal efficiency with significant improvement in reduction of particulates, carbon monoxide and unburnt hydrocarbons is observed compared to diesel. The use of transesterified used cooking oil and its blends as fuel for diesel engines will reduce dependence on fossil fuels and also decrease considerably the environmental pollution.