Abstract: In this study, a reformer model simulation to use
refinery (Farashband refinery, Iran) waste natural gas. In the
petroleum and allied sectors where natural gas is being encountered
(in form of associated gas) without prior preparation for its positive
use, its combustion (which takes place in flares, an equipment through
which they are being disposed) has become a great problem because
of its associated environmental problems in form of gaseous emission.
The proposed model is used to product syngas from waste natural gas.
A detailed steady model described by a set of ordinary differential and
algebraic equations was developed to predict the behavior of the
overall process. The proposed steady reactor model was validated
against process data of a reformer synthesis plant recorded and a good
agreement was achieved. H2/CO ratio has important effect on Fischer-
Tropsch synthesis reactor product and we try to achieve this parameter
with best designing reformer reactor. We study different kind of
reformer reactors and then select auto thermal reforming process of
natural gas in a fixed bed reformer that adjustment H2/CO ratio with
CO2 and H2O injection. Finally a strategy was proposed for prevention
of extra natural gas to atmosphere.
Abstract: Commercial hydroxyapatite (HA) was reinforced by
adding 2, 5, and 10 wt % of 28.5%CaO-28.5%P2O5-38%Na2 O-
5%CaF2 based glass and then sintered. Although HA shows good
biocompatibility with the human body, its applications are limited to
non load-bearing areas and coatings due to its poor mechanical
properties. These mechanical properties can be improved
substantially with addition of glass ceramics by sintering. In this
study, the effects of sintering hydroxyapatite with above specified
phosphate glass additions are quantified. Each composition was
sintered over a range of temperatures. Scanning electron microscopy
and x-ray diffraction were used to characterize the microstructure and
phases of the composites. The density, microhardness, and
compressive strength were measured using Archimedes Principle,
Vickers Microhardness Tester (at 0.98 N), and Instron Universal
Testing Machine (cross speed of 0.5 mm/min) respectively. These
results were used to indicate which composition provided suitable
material for use in hard tissue replacement. Composites containing 10
wt % glass additions formed dense HA/TCP (tricalcium phosphate)
composite materials possessing good compressive strength and
hardness than HA. In-vitro bioactivity was assessed by evaluating
changes in pH and Ca2+ ion concentration of SBF-simulated body
fluid on immersion of these composites in it for two weeks.
Abstract: The effects of different parameters on the
hydrodynamics of trickle bed reactors were discussed for Newtonian
and non-Newtonian foaming systems. The varying parameters are
varying liquid velocities, gas flow velocities and surface tension. The
range for gas velocity is particularly large, thanks to the use of dense
gas to simulate very high pressure conditions. This data bank has
been used to compare the prediction accuracy of the different
trendlines and transition points from the literature. More than 240
experimental points for the trickle flow (GCF) and foaming pulsing
flow (PF/FPF) regime were obtained for present study.
Hydrodynamic characteristics involving dynamic liquid saturation
significantly influenced by gas and liquid flow rates. For 15 and 30
ppm air-aqueous surfactant solutions, dynamic liquid saturation
decreases with higher liquid and gas flow rates considerably in high
interaction regime. With decrease in surface tension i.e. for 45 and 60
ppm air-aqueous surfactant systems, effect was more pronounced
with decreases dynamic liquid saturation very sharply during regime
transition significantly at both low liquid and gas flow rates.
Abstract: In this research sodium bicarbonate (NaHCO3) was introduced to generate carbon dioxide gas (CO2) to the existing nitrogen gas (N2) of elastomeric foam, to lower thermal conductivity (K). Various loadings of NaHCO3 (0 to 60 phr) were added into the azodicarbonamide (AZC)-containing compound and its properties were then determined. Two vulcanization methods, i.e., hot air and infrared (IR), were employed and compared in this study. Results revealed that compound viscosity tended to increase slightly with increasing NaHCO3 content but cure time was delayed. The effect of NaHCO3 content on thermal conductivity depended on the vulcanization method. For hot air method, the thermal conductivity was insignificantly changed with increasing NaHCO3 up to 40 phr whereas it tended to decrease gradually for IR method. At higher NaHCO3 content (60 phr), unexpected increase of thermal conductivity was observed. The water absorption was also determined and foam structures were then used to explain the results.
Abstract: A mathematical model of the surface roughness
has been developed by using response surface methodology
(RSM) in grinding of AISI D2 cold work tool steels. Analysis
of variance (ANOVA) was used to check the validity of the
model. Low and high value for work speed and feed rate are
decided from design of experiment. The influences of all
machining parameters on surface roughness have been
analyzed based on the developed mathematical model. The
developed prediction equation shows that both the feed rate
and work speed are the most important factor that influences
the surface roughness. The surface roughness was found to be
the lowers with the used of low feed rate and low work speed.
Accuracy of the best model was proved with the testing data.
Abstract: Chemical industry project management involves
complex decision making situations that require discerning abilities
and methods to make sound decisions. Project managers are faced
with decision environments and problems in projects that are
complex. In this work, case study is Research and Development
(R&D) project selection. R&D is an ongoing process for forward
thinking technology-based chemical industries. R&D project
selection is an important task for organizations with R&D project
management. It is a multi-criteria problem which includes both
tangible and intangible factors. The ability to make sound decisions
is very important to success of R&D projects. Multiple-criteria
decision making (MCDM) approaches are major parts of decision
theory and analysis. This paper presents all of MCDM approaches
for use in R&D project selection. It is hoped that this work will
provide a ready reference on MCDM and this will encourage the
application of the MCDM by chemical engineering management.
Abstract: Palm shell obtained from coastal part of southern
India was studied for the removal for the adsorption of Hg (II) ions.
Batch adsorption experiments were carried out as a function of pH,
concentration of Hg (II) ions, time, temperature and adsorbent dose.
Maximum removal was seen in the range pH 4.0- pH 7.0. The palm
shell powder used as adsorbent was characterized for its surface area,
SEM, PXRD, FTIR, ion exchange capacity, moisture content, and
bulk density, soluble content in water and acid and pH. The
experimental results were analyzed using Langmuir I, II, III, IV and
Freundlich adsorption isotherms. The batch sorption kinetics was
studied for the first order reversible reaction, pseudo first order;
pseudo second order reaction and the intra-particle diffusion reaction.
The biomass was successfully used for removal Hg (II) from
synthetic and industrial effluents and the technique appears
industrially applicable and viable.
Abstract: Controlled release urea has become popular in agricultural industry as it helps to solve environmental issues and increase crop yield. Recently biomass was identified to replace the polymer used as a coating material in the conventional coated urea. In this paper spreading and contact angle of biomass droplet (lignin, cellulose and clay) on urea surface are investigated experimentally. There were two tests were conducted, sessile drop for contact angle measurement and pendant drop for contact angle measurement. A different concentration of biomass droplet was released from 30 mm above a substrate. Glass was used as a controlled substrate. Images were recorded as soon as the droplet impacted onto the urea before completely adsorb into the urea. Digitized droplets were then used to identify the droplet-s surface tension and contact angle. There is large difference observed between the low surface tension and high surface tension liquids, where the wetting and spreading diameter is higher for lower surface tension. From the contact angle results, the data showed that the biomass coating films were possible as wetting liquid (θ < 90º). Contact angle of biomass coating material gives good indication for the wettablity of a liquid on urea surface.
Abstract: Perturbed-Chain Statistical Association Fluid Theory (PC-SAFT) equation of state (EOS) is a modified SAFT EOS with three pure component specific parameters: segment number (m), diameter (σ) and energy (ε). These PC-SAFT parameters need to be determined for each component under the conditions of interest by fitting experimental data, such as vapor pressure, density or heat capacity. PC-SAFT parameters for propane, ethylene and hydrogen in supercritical region were successfully estimated by fitting experimental density data available in literature. The regressed PCSAFT parameters were compared with the literature values by means of estimating pure component density and calculating average absolute deviation between the estimated and experimental density values. PC-SAFT parameters available in literature especially for ethylene and hydrogen estimated density in supercritical region reasonably well. However, the regressed PC-SAFT parameters performed better in supercritical region than the PC-SAFT parameters from literature.
Abstract: Catalytic converters are used for minimizing the release of pollutants to the atmosphere. It is during the warm-up period that hydrocarbons are seen to be released in appreciable quantities from these converters. In this paper the conversion of a fast oxidizing hydrocarbon propylene is analysed using two numerical methods. The quasi steady state method assumes the accumulation terms to be negligible in the gas phase mass and energy balance equations, however this term is present in the solid phase energy balance. The unsteady state model accounts for the accumulation term to be present in the gas phase mass and energy balance and in the solid phase energy balance. The results derived from the two models for gas concentration, gas temperature and solid temperature are compared.
Abstract: Three alumina-supported Pt-Sn catalysts have been
prepared by means of co-impregnation and characterized by XRD and
N2 adsorption. The influence of catalyst composition and reaction
conditions on the conversion and selectivity were investigated in the
hydrogenation of acetic acid in an isothermal integral fixed bed
reactor. The experiments were performed on the temperature interval
468-548 K, liquid hourly space velocity (LHSV) of 0.3-0.7h-1,
pressures between 1.0 and 5.0Mpa. A good compromise of
0.75%Pt-1.5%Sn can act as an optimized acetic acid hydrogenation
catalyst, and the conversion and selectivity can be tuned through the
variation of reaction conditions.
Abstract: This paper presents the modeling results of an
innovative system for the temperature control in the interior
compartment of a stationary automobile facing the solar energy from
the sun. A very thin layer of PCM inside a pouch placed in the
ceiling of the car in which the heating energy is absorbed and release
with melting and solidification of phase change materials. As a result
the temperature of the car interior is maintained in the comfort
condition. The amount of required PCM has been calculated to be
about 755 g. The PCM-temperature controlling system is simple and
has a potential to be implemented as a practical solution to prevent
undesirable heating of the automobile-s cabin.
Abstract: A composite made of plasma functionalized multiwall
carbon nanotubes (MWNTs) coated with SnO2 was synthesized by
sonochemical precipitation method. Thick layer of this
nanocomposite material was used as ethanol sensor at low
temperatures. The composite sensitivity for ethanol has increased by
a factor of 2 at room temperature and by a factor of 13 at 250°C in
comparison to that of pure SnO2. SEM image of nanocomposite
material showed MWNTs were embedded in SnO2 matrix and also a
higher surface area was observed in the presence of functionalized
MWNTs. Greatly improved sensitivity of the composite material to
ethanol can be attributed to new gas accessing passes through
MWNTs and higher specific surface area.
Abstract: In the past many uneconomic solutions for limitation
and interruption of short-circuit currents in low power applications
have been introduced, especially polymer switch based on the
positive temperature coefficient of resistance (PCTR) concept.
However there are many limitations in the active material, which
consists of conductive fillers. This paper presents a significantly
improved and simplified approach that replaces the existing current
limiters with faster switching elements. Its elegance lies in the
remarkable simplicity and low-cost processes of producing the device
using polyaniline (PANI) doped with methane-sulfonic acid (MSA).
Samples characterized as lying in the metallic and critical regimes of
metal insulator transition have been studied by means of electrical
performance in the voltage range from 1V to 5 V under different
environmental conditions. Moisture presence is shown to increase the
resistivity and also improved its current limiting performance.
Additionally, the device has also been studied for electrical resistivity
in the temperature range 77 K-300 K. The temperature dependence of
the electrical conductivity gives evidence for a transport mechanism
based on variable range hopping in three dimensions.
Abstract: Herein, the organic semiconductor methyl orange
(MO), is investigated for the first time for its electronic applications.
For this purpose, Al/MO/n-Si heterojunction is fabricated through
economical cheap and simple “drop casting” technique. The currentvoltage
(I-V) measurements of the device are made at room
temperature under dark conditions. The I-V characteristics of
Al/MO/n-Si junction exhibits asymmetrical and rectifying behavior
that confirms the formation of diode. The diode parameters such as
rectification ratio (RR), turn on voltage (Vturn on), reverse saturation
current (I0), ideality factor (n), barrier height ( b
f ), series resistance
(Rs) and shunt resistance (Rsh) are determined from I-V curves using
Schottky equations. These values of these parameters are also
extracted and verified by applying Cheung’s functions. The
conduction mechanisms are explained from the forward bias I-V
characteristics using the power law.
Abstract: A phorbol-12-myristate-13-acetate (TPA) is a synthetic analogue of phorbol ester (PE), a natural toxic compound of Euphorbiaceae plant. The oil extracted from plants of this family is useful source for primarily biofuel. However this oil might also be used as a foodstuff due to its significant nutrition content. The limitations for utilizing the oil as a foodstuff are mainly due to a toxicity of PE. Currently, a majority of PE detoxification processes are expensive as include multi steps alcohol extraction sequence.
Ozone is considered as a strong oxidative agent. It reacts with PE by attacking the carbon-carbon double bond of PE. This modification of PE molecular structure yields a non toxic ester with high lipid content.
This report presents data on development of simple and cheap PE detoxification process with water application as a buffer and ozone as reactive component. The core of this new technique is an application for a new microscale plasma unit to ozone production and the technology permits ozone injection to the water-TPA mixture in form of microbubbles.
The efficacy of a heterogeneous process depends on the diffusion coefficient which can be controlled by contact time and interfacial area. The low velocity of rising microbubbles and high surface to volume ratio allow efficient mass transfer to be achieved during the process. Direct injection of ozone is the most efficient way to process with such highly reactive and short lived chemical.
Data on the plasma unit behavior are presented and the influence of gas oscillation technology on the microbubble production mechanism has been discussed. Data on overall process efficacy for TPA degradation is shown.
Abstract: Sport is one of the sectors in which the largest
technical projections regarding the functions of textiles can be found.
He is a large consumer of high performance composite materials and
new fibers. It is one of the sectors where the innovation is the most
important when the greatest numbers of spectacular developments are
aimed at increasing performance. In medicine, textile innovation is
used and contributes in the amelioration of different materials such as
dressing, orthosis, bandages, etc. The hygienic textiles in non-woven
materials record a strong growth. The objective of this study is to
show the different advances of development we obtained in the both
ways (sport and medicine). Polyamide fibers where developed
tacking into account the specification of the high level athlete’s
performance like swimming and triathlon (Olympic Games, Brazil
2016). The first textile utilization was for skiing (Olympic Games,
Sotchi 2014). The different textiles technologies where adapted for
medicine.
Abstract: A new generation product made from bamboo strips,
known as laminated bamboo, has gained importance. The objective
of this research was to experiment the effect of three factors on the
mechanical property of laminated bamboo. The interested factors for
experimental design were (A) four bamboo species, namely Bambusa
blumeana Schultes (Pai See Suk), Dendrocalamus asper Backer (Pai
Tong), Dendrocalamus hamiltonii Nees (Pai Hok) and
Dendrocalamus sericeus Munro (Pai Sang Mon), (B) two types of
glue adhesive, polyvinyl acetate emulsion (PVAC) fortified with
urea-formaldehyde (UF) and urea-formaldehyde (UF) to make
parallel-oriented bamboo strips laminates and (C) glue weight per
strip area, 150 g/m2 and 190 g/m2. Experimental results showed that
Dendrocalamus asper Backer (Pai Tong) and Dendrocalamus
sericeus Munro (Pai Sang Mon) were best used for manufacturing
due to their highest MOR and MOE. The amount of glue weight 150
g/m2 yielded higher MOR and MOE than the amount of glue weight
190 g/m2. At the conclusion, the laminated bamboo manufacturers
can benefit from this research in order to select right materials
according to strength, cost and accessibility.
Abstract: In this study, the ability of Aspergillus niger and
Penicillium simplicissimum to extract heavy metals from a spent
refinery catalyst was investigated. For the first step, a spent
processing catalyst from one of the oil refineries in Iran was
physically and chemically characterized. Aspergillus niger and
Penicillium simplicissimum were used to mobilize Al/Co/Mo/Ni from
hazardous spent catalysts. The fungi were adapted to the mixture of
metals at 100-800 mg L-1 with increments in concentration of 100 mg
L-1. Bioleaching experiments were carried out in batch cultures. To
investigate the production of organic acids in sucrose medium,
analyses of the culture medium by HPLC were performed at specific
time intervals after inoculation. The results obtained from Inductive
coupled plasma-optical emission spectrometry (ICP-OES) showed
that after the one-step bioleaching process using Aspergillus niger,
maximum removal efficiencies of 27%, 66%, 62% and 38% were
achieved for Al, Co, Mo and Ni, respectively. However, the highest
removal efficiencies using Penicillium simplicissimum were of 32%,
67%, 65% and 38% for Al, Co, Mo and Ni, respectively
Abstract: The bromination of five selected pharmaceuticals
(metoprolol, naproxen, amoxicillin, hydrochlorotiazide and
phenacetin) in ultrapure water and in three water matrices (a
groundwater, a surface water from a public reservoir and a secondary
effluent from a WWTP) was investigated. The apparent rate
constants for the bromination reaction were determined as a function
of the pH, and the sequence obtained for the reaction rate was
amoxicillin > naproxen >> hydrochlorotiazide ≈ phenacetin ≈
metoprolol. The proposal of a kinetic mechanism, which specifies the
dissociation of bromine and each pharmaceutical according to their
pKa values and the pH allowed the determination of the intrinsic rate
constants for every elementary reaction. The influence of the main
operating conditions (pH, initial bromine dose, and the water matrix)
on the degradation of pharmaceuticals was established. In addition,
the presence of bromide in chlorination experiments was
investigated. The presence of bromide in wastewaters and drinking
waters in the range of 10 to several hundred μg L-1 accelerated
slightly the oxidation of the selected pharmaceuticals during chorine
disinfection.