Abstract: This paper reports the three-phase (gas + liquid +
hydrate) equilibrium pressure versus temperature data for a (O3 + O2 +
CO2 + H2O) system for developing the hydrate-based technology to
preserve ozone, a chemically unstable substance, for various
industrial, medical and consumer uses. These data cover the
temperature range from 272 K to 277 K, corresponding to pressures
from 1.6 MPa to 3.1 MPa, for each of the three different (O3 +
O2)-to-CO2 or O2-to-CO2 molar ratios in the gas phase, which are
approximately 4 : 6, 5 : 5, respectively. The mole fraction of ozone in
the gas phase was ~0.03 , which are the densest ozone fraction to
artificially form O3 containing hydrate ever reported in the literature.
Based on these data, the formation of hydrate containing
high-concentration ozone, as high as 1 mass %, will be expected.
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: In this study, the kinetics of osmotic dehydration of melons (Tille variety) in a ternary system followed by air-drying for preserving melons in the summer to be used in the winter were investigated. The effect of different osmotic solution concentrations 30, 40 and 50% (w/w) of sucrose with 10% NaCl salt and fruit to solution ratios 1:4, 1:5 and 1:6 on the mass transfer kinetics during osmotic dehydration of melon in ternary solution namely sucrosesalt- water followed by air-drying were studied. The diffusivity of water during air-drying was enhanced after the fruit samples were immersed in the osmotic solution after 60 min. Samples non-treated and pre-treated during one hour in osmotic solutions with 60% (w/w) of sucrose with 10% NaCl salt and fruit to solution ratio of 1:4 were dried in a hot air-dryer at 60oC (2 m/s) until equilibrium was achieved.
Abstract: Fly ash is one of the residues generated in
combustion, and comprises the fine particles that rise with the flue
gases. Ash which does not rise is termed bottom ash [1]. In our
country, it is expected that will be occurred 50 million tons of waste
ash per year until 2020. Released waste from the thermal power
plants is caused very significant problems as known. The fly ashes
can be evaluated by using as adsorbent material.
The purpose of this study is to investigate the possibility of use of
Tuncbilek fly ash like low-cost adsorbents for heavy metal
adsorption. First of all, Tuncbilek fly ash was characterized. For this
purpose; analysis such as sieve analysis, XRD, XRF, SEM and FT-IR
were performed.
Abstract: The catalytic dehydroxylation of glycerol to propylene
glycol was investigated over Cu-ZnO/Al2O3 prepared by incipient
wetness impregnation (IWI) method with different purity feedstocks -
refined glycerol and technical grade glycerol. The main purpose is to
investigate the effects of feed impurities that cause the catalyst
deactivation. The prepared catalyst were tested for its catalytic
activity and selectivity in a continuous flow fixed bed reactor at 523
K, 500 psig, H2/feed molar ratio of 4 and WHSV of 3 h-1. The results
showed that conversion of refined glycerol and technical grade
glycerol at time on stream 6 hour are 99% and 71% and selectivity to
propylene glycol are 87% and 56% respectively. The ICP-EOS and
TPO results indicated that the cause of catalyst deactivation was the
amount of impurities in the feedstock. The higher amount of
impurities (especially Na and K) the lower catalytic activity.
Abstract: Biodisel is a type of biofuel having similar properties of diesel fuel but lacks substances (undesirable emissions) such as sulfur, nitrogen and aromatic polycyclic. Upon filtration of waste oil, the biodiesel fuel was produced via carrying out transestrification reaction of triglycerides followed by conducting viscosity, density, flash point, cloud point, pour point and copper strip corrosion tests on the samples and comparing with EN14214 and ASTM 6751 standards and all results were found in the permitted limit. The highest yield of biodiesel production reaction was found 46.6435 g when Sodium Hydroxide catalyst in amount of 0.375g was employed, 44.2347 g when Sodium methoxide catalyst in amount of 0.5g was employed and 56.5124 g when acid sulfuric catalyst in amount of 1g was employed and 47.3290 g when two stage reaction was done.
Abstract: In the previous multi-solid models,¤ò approach is
used for the calculation of fugacity in the liquid phase. For the first
time, in the proposed multi-solid thermodynamic model,γ approach
has been used for calculation of fugacity in the liquid mixture.
Therefore, some activity coefficient models have been studied that
the results show that the predictive Wilson model is more appropriate
than others. The results demonstrate γ approach using the predictive
Wilson model is in more agreement with experimental data than the
previous multi-solid models. Also, by this method, generates a new
approach for presenting stability analysis in phase equilibrium
calculations. Meanwhile, the run time in γ approach is less than the
previous methods used ¤ò approach. The results of the new model
present 0.75 AAD % (Average Absolute Deviation) from the
experimental data which is less than the results error of the previous
multi-solid models obviously.
Abstract: Lignocellulosic materials are new targeted source to
produce second generation biofuels like biobutanol. However, this
process is significantly resisted by the native structure of biomass.
Therefore, pretreatment process is always essential to remove
hemicelluloses and lignin prior to the enzymatic hydrolysis.
The goals of pretreatment are removing hemicelluloses and
lignin, increasing biomass porosity, and increasing the enzyme
accessibility. The main goal of this research is to study the important
variables such as pretreatment temperature and time, which can give
the highest total sugar yield in pretreatment step by using dilute
phosphoric acid. After pretreatment, the highest total sugar yield of
13.61 g/L was obtained under an optimal condition at 140°C for 10
min of pretreatment time by using 1.75% (w/w) H3PO4 and at 15:1
liquid to solid ratio. The total sugar yield of two-stage process
(pretreatment+enzymatic hydrolysis) of 27.38 g/L was obtained.
Abstract: In this paper, vapour-liquid critical locus for the
binary system acetone + chloroform was determined experimentally
over the whole range of composition. The critical property
measurements were carried out using a dynamic-synthetic apparatus,
employed in the dynamic mode. The critical points are visually
determined by observing the critical opalescence and the
simultaneous disappearance and reappearance of the meniscus in the
middle of a high-pressure view cell which withstands operations up
to 673K and 20MPa. The experimental critical points measured in
this work were compared to those available in literature.
Abstract: The submitted paper deals with the problems of
trapping and enriching the gases and aerosols of the substances to be
determined in the ambient atmosphere. Further, the paper is focused
on the working principle of the miniaturized portable continuous
concentrator we have designed and the possibilities of its
application in air sampling and accumulation of organic and
inorganic substances with which the air is contaminated. The stress is
laid on trapping vapours and aerosols of solid substances with the
comparatively low vapour tension such as explosive compounds.
Abstract: Anaerobic treatment has many advantages over other
biological method particularly when used to treat complex
wastewater such as petroleum refinery wastewater. In this study two
Up-flow Anaerobic Sludge Blanket (UASB) reactors were operated
in parallel to treat six volumetric organic loads (0.58, 1.21, 0.89,
2.34, 1.47 and 4.14 kg COD/m3·d) to evaluate the chemical oxygen
demand (COD) removal efficiency. The reactors were continuously
adapting to the changing of operation condition with increase in the
removal efficiency or slight decrease until the last load which was
more than two times the load, at which the reactor stressed and the
removal efficiency decreased to 75% with effluent concentration of
1746 mg COD/L. Other parameters were also monitored such as pH,
alkalinity, volatile fatty acid and gas production rate. The UASB
reactor was suitable to treat petroleum refinery wastewater and the
highest COD removal rate was 83% at 1215 kg/m3·d with COD
concentration about 356 mg/L in the effluent.
Abstract: Poly (ethylene glycol) (PEG) molecules attached to surfaces have shown high potential as a protein repellent due to their flexibility and highly water solubility. A quartz crystal microbalance recording frequency and dissipation changes (QCM-D) has been used to study the adsorption from aqueous solutions, of lysozyme and α-lactalbumin proteins (the last with and without calcium) onto modified stainless steel surfaces. Surfaces were coated with poly(ethylene imine) (PEI) and silicate before grafting on PEG molecules. Protein adsorption was also performed on the bare stainless steel surface as a control. All adsorptions were conducted at 23°C and pH 7.2. The results showed that the presence of PEG molecules significantly reduced the adsorption of lysozyme and α- lactalbumin (with calcium) onto the stainless steel surface. By contrast, and unexpected, PEG molecules enhanced the adsorption of α-lactalbumin (without calcium). It is suggested that the PEG -α- lactalbumin hydrophobic interaction plays a dominant role which leads to protein aggregation at the surface for this latter observation. The findings also lead to the general conclusion that PEG molecules are not a universal protein repellent. PEG-on-PEI surfaces were better at inhibiting the adsorption of lysozyme and α-lactalbumin (with calcium) than with PEG-on-silicate surfaces.
Abstract: Biodiesel is traditionally produced from oleaginous
plants. On the other hand, increasing biodiesel production from these
raw materials could create problems of food supply. Producing
biodiesel from microalgae could help to overcome this difficulty,
because microalgae are rich in lipids and do not compete for arable
lands. However, no studies had compared vegetable and microalgae
oil-based biodiesel in terms of yield, viscosity and heat of
combustion. In the present study, commercial canola and microalgae
oil were therefore transesterified with methanol under a homogenous
alkali catalyst (potassium hydroxide) at 100oC for 1h. The result
showed that microalgae-based oil has a higher yield in biodiesel with
89.7% (g biodiesel/g oil) and a lower kinematic viscosity (22oC) of
4.31 mm/s2 than canola oil.
Abstract: A simple method for the simultaneous determination
of hippuric acid and benzoic acid in urine using reversed-phase high
performance liquid chromatography was described. Chromatography
was performed on a Nova-Pak C18 (3.9 x 150 mm) column with a
mobile phase of mixed solution methanol: water: acetic acid
(20:80:0.2) and UV detection at 254 nm. The calibration curve was
linear within concentration range at 0.125 to 6.0 mg/ml of hippuric
acid and benzoic acid. The recovery, accuracy and coefficient
variance of hippuric acid were 104.54%, 0.2% and 0.2% respectively
and for benzoic acid were 98.48%, 1.25% and 0.60% respectively.
The detection limit of this method was 0.01ng/l for hippuric acid and
0.06ng/l for benzoic acid. This method has been applied to the
analysis of urine samples from the suspected of toluene abuser or
glue sniffer among secondary school students at Johor Bahru.
Abstract: Among the chemicals used for ammunition production, TNT (Trinitrotoluene) play a significant role since World War I and II. Various types of military weapon utilize TNT in casting process. However, the TNT casting process for warhead is difficult to control the cooling rate of the liquid TNT. This problem occurs because the casting process lacks the equipment to detect the temperature during the casting procedure This study presents the temperature detected by infrared camera to illustrate the cooling rate and cooling zone of curing, and demonstrates the optimization of TNT condition to reduce the risk of air gap occurred in the warhead which can result in the destruction afterward. Premature initiation of explosive-filled projectiles in response to set-back forces during gunfiring cause by casting defects. Finally the study can help improving the process of the TNT casting. The operators can control the curing of TNT inside the case by rising up the heating rod at the proper time. Consequently this can reduce tremendous time of rework if the air gaps occur and increase strength to lower elastic modulus. Therefore, it can be clearly concluded that the use of Infrared Cameras in this process is another method to improve the casting procedure.
Abstract: Polyurethane foams (PUF) were formed by a chemical
reaction of polyol and isocyanate. The polyol was manufactured by
ring-opening hydrolysis of epoxidized soybean oil in the presence of
phosphoric acid under varying experimental conditions. Other
factors in the foam formulation such as water content and surfactant
were kept constant. The effect of the amount of solvents, phosphoric
acid, and their derivates in the foam formulation on the properties of
polyurethane foams were studied. The properties of the material were
measured via a number of parameters, which are water content of
prepared polyol, polymer density and cellular structures.
Abstract: Cobalt was acid nitric leached from a mixed cobaltcopper
oxide with variable acid concentration. Resulting
experimental data were used to analyze effects of increase in acid
concentration, based on a shrinking core model of the process. The
mathematical simulation demonstrated that the time rate of the
dissolution mechanism is an increasing function of acid
concentration. It was also shown that the magnitude of the acid
concentration effect is time dependent and the increase in acid
concentration is more effective at earlier stage of the dissolution than
at later stage. The remaining process parameters are comprehensively
affected by acid concentration and their interaction is synergetic.
Abstract: The possibility of producing drinking water from
brackish ground water using Vacuum membrane distillation (VMD)
process was studied. It is a rising technology for seawater or brine
desalination process. The process simply consists of a flat sheet
hydrophobic micro porous PTFE membrane and diaphragm vacuum
pump without a condenser for the water recovery or trap. In this
work, VMD performance was investigated for aqueous NaCl solution
and natural ground water. The influence of operational parameters
such as feed flow rate (30 to 55 l/h), feed temperature (313 to 333 K),
feed salt concentration (5000 to 7000 mg/l) and permeate pressure
(1.5 to 6 kPa) on the membrane distillation (MD) permeation flux
have been investigated. The maximum flux reached to 28.34 kg/m2 h
at feed temperature, 333 K; vacuum pressure, 1.5 kPa; feed flow rate,
55 l/h and feed salt concentration, 7000 mg/l. The negligible effects
in the reduction of permeate flux found over 150 h experimental run
for salt water. But for the natural ground water application over 75 h,
scale deposits observed on the membrane surface and 29% reduction
in the permeate flux over 75 h. This reduction can be eliminated by
acidification of feed water. Hence, promote the research attention in
apply of VMD for the ground water purification over today-s
conventional RO operation.
Abstract: The dissolution of spherical particles in liquids is analyzed dynamically. Here, we consider the case the dissolution of solute yields a solute-free solid phase in the outer portion of a particle. As dissolution proceeds, the interface between the undissolved solid phase and the solute-free solid phase moves towards the center of the particle. We assume that there exist two resistances for the diffusion of solute molecules: the resistance due to the solute-free portion of the particle and that due to a surface layer near solid-liquid interface. In general, the equation governing the dynamic behavior of dissolution needs to be solved numerically. However, analytical expressions for the temporal variation of the size of the undissoved portion of a particle and the variation of dissolution time can be obtained in some special cases. The present analysis takes the effect of variable bulk solute concentration on dissolution into account.
Abstract: A horizontal anaerobic digester was developed and
tested in pilot scale for Korean food waste with high water contents
(>80%). The hydrogen sulfide in the biogas was removed by a
biological desulfurization equipment integrated in the horizontal
digester. A mixer of the horizontal digester was designed to easily
remove the sediment in the bottom and scum layers on surface in the
digester. Experimental result for 120 days of operation of the pilot
plant showed a high removal efficiency of 81.2% for organic
substance and high stability during the whole operation period were
acquired. Also food waste was treated at high organic loading rates
over 4 kg•VS/m3∙day and a methane gas production rate of 0.62
m3/kg•VSremoved was accomplished.
The biological desulfurization equipment inside the horizontal
digester was proven to be an economic and effective method to reduce
the biogas desulfurization cost by removing hydrogen sulfide more
than 90% without external desulfurization equipments.