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1.
Won-Joon Choi Jong-Beom Seo Sang-Won Cho Sang-Wook Park Kwang-Joong Oh 《Korean Journal of Chemical Engineering》2009,26(3):705-710
To enhance the absorption rate for CO2 and SO2, aqueous ammonia (NH3) solution was added to an aqueous 2-amino-2-methyl-1-propanol (AMP) solution. The simultaneous absorption rates of AMP and
a blend of AMP+ NH3 for CO2 and SO2 were measured by using a stirred-cell reactor at 303 K. The process operating parameters of interest in this study were the
solvent and concentration, and the partial pressures of CO2 and SO2. As a result, the addition of NH3 solution into aqueous AMP solution increased the reaction rate constants of CO2 and SO2 by 144 and 109%, respectively, compared to that of AMP solution alone. The simultaneous absorption rate of CO2/SO2 on the addition of 1 wt% NH3 into 10 wt% AMP at a p
A1 of 15 kPa and p
A2 of 1 kPa was 5.50×10−6 kmol m−2 s−1, with an increase of 15.5% compared to 10 wt% AMP alone. Consequently, the addition of NH3 solution into an aqueous AMP solution would be expected to be an excellent absorbent for the simultaneous removal of CO2/SO2 from the composition of flue gas emitted from thermoelectric power plants. 相似文献
2.
Bong Gill Choi Gyo Hee Kim Kwang Bok Yi Jong-Nam Kim Won Hi Hong 《Korean Journal of Chemical Engineering》2012,29(4):478-482
Although aqueous ammonia solution has been focused on the removal of CO2 from flue gas, there have been very few reports regarding the underlying analysis of the reaction between CO2 and NH3. In this work, we explored the reaction of CO2-NH3-H2O system at various operating temperatures: 40 °C, 20 °C, and 5 °C. The CO2 removal efficiency and the loss of ammonia were influenced by the operating temperatures. Also, infrared spectroscopy measurement
was used in order to understand the formation mechanism of ion species in absorbent, such as NH2COO−, HCO3−, CO32−, and NH4+, during CO2, NH3, and H2O reaction. The reactions of CO2-NH3-H2O system at 20 °C and 40 °C have similar reaction routes. However, a different reaction route was observed at 5 °C compared
to the other operating temperatures, showing the solid products of ammonium bicarbonates, relatively. The CO2 removal efficiency and the formation of carbamate and bicarbonate were strongly influenced by the operating temperatures.
In particular, the analysis of the formation carbamate and bicarbonate by infrared spectroscopy measurement provides useful
information on the reaction mechanism of CO2 in an aqueous ammonia solution. 相似文献
3.
The novel half-titanocene catalyst bearing reactive functional amino group, η5-pentamethylcyclopentadienyltri(p-amino-phenoxyl) titanium [Cp∗Ti(p-OC6H4NH2)3],
was easily synthesized by the reaction of η5-pentamethylcyclopentadienyltrichloride
titanium (Cp∗TiCl3) with p-amino
phenol in the presence of triethyl amine (NEt3). Cp∗Ti(p-OC6H4NH2)3
covalently anchored on MgCl2/AlEtn(OEt)3-n
support obtained from the reaction of triethylaluminium (AlEt3) with the adduct
of magnesium chloride (MgCl2) and ethanol (EtOH), has been investigated and used
to catalyze syndiospecific polymerization of styrene. Influences of the support structure, cocatalyst,
and the molar ratio of Al in methylaluminoxane (MAO) and Ti (AlMAO/Ti) on catalytic
activity, syndiotacticity and molecular weight of the resultant polystyrene were investigated. Compared
with the corresponding Cp∗Ti(p-OC6H4NH2)3
homogeneous catalyst, a considerable increase in activity and molecular weight of syndiotactic polystyrene
(sPS) was observed for the Cp∗Ti(p-OC6H4NH2)3-MgCl2/AlEtn(OEt)3-n
supported catalyst even at a relatively low AlMAO/Ti ratio of 50, and the kinetics
of polymerization was stable during the reaction process. 相似文献
4.
Feng Wu Huaquan Lu Yuefeng Su Ning Li Liying Bao Shi Chen 《Journal of Applied Electrochemistry》2010,40(4):783-789
The Li-rich layered cathode material, Li[Ni0.2Li0.2Mn0.6]O2, was synthesized via a “mixed oxalate” method, and its structural and electrochemical properties were compared with the same
material synthesized by the sol–gel method. X-ray diffraction (XRD) shows that the synthesized powders have a layered O3–LiCoO2-type structure with the R-3m symmetry. X-ray photoelectron spectroscopy (XPS) indicates that in the above material, Ni and Mn exist in the oxidation states
of +2 and +4, respectively. The layered material exhibits an excellent electrochemical performance. Its discharge capacity
increases gradually from the initial value of 228 mA hg−1 to a stable capacity of over 260 mA hg−1 after the 10th cycle. It delivers a larger capacity of 258 mA hg−1 at the 30th cycle. The dQ/dV curves suggest that the increasing capacity results from the redox-reaction of Mn4+/Mn3+. 相似文献
5.
The Sb2O3 doping lead-free glass in Bi2O3-B2O3-BaO ternary system were prepared in the composition of several different subsystem, and the glass powder was produced through
the process of water quenching. Glass transition temperatures (T
g
), glass soften temperatures(T
s
), the volume resistivity (ρ) in the temperature range of 80–200°C, and linear thermal coefficients of expansion in the temperatures
range of 25–300°C (α25–300) were measured for subsystems along with the different ratio of Bi2O3, B2O3 and BaO. For these subsystems, T
g
ranged from 458 to 481°C, and T
s
ranged from 490 to 512°C, both decreasing with the increasing of Bi2O3/B2O3 ratio, and increasing with the increasing of BaO/B2O3 ratio. The measured α25–300 ranged from 65.3 to 76.3 × 10−7 K−1, with values increasing with increasing Bi2O3/B2O3 and BaO/B2O3 ratio. The volume resistivity remains at a high standards, which may caused by it’s non-alkali composition, and it fluctuated
from 1013 to 1011 Ω cm with the temperature varied from 80–200°C. The structure of Bi2O3-B2O3-BaO ternary leadfree glass system was mearsured by FT-IR. The IR studies indicate that these glasses are made up of [BiO6], [BO3], and [BO4] basic structural units, and it appears that Ba2+ acts as a glass-modifier in this ternary system, but the Bi3+ has entered the glass network when it is in relative high content so as to change the α25–300, T
s
and T
g
. 相似文献
6.
A. Yu. Krylova V. I. Kurkin M. V. Kulikova A. S. Lyadov S. A. Sagitov 《Solid Fuel Chemistry》2011,45(4):281-285
It was demonstrated that R
2–R
4 saturated monohydric alcohols can be synthesized from CO and H2 in the presence of Fe catalysts containing a carbon support of the Sibunit type with granule sizes of 3–5, 1–2, and 0.05–0.1
mm in a fixed-bed reactor at 3 MPa and 240–300°C. It was found that the activity of Fe/Sibunit catalysts and their selectivity
for the formation of liquid synthetic products increased with the size of granules and the amount of iron. The catalysts make
it possible to obtain fatty alcohols, in which the fraction of R
2–R
4 alcohols is as high as 75%, in yields to 56 g/m3. 相似文献
7.
Hanne Rönkkönen Pekka Simell Matti Reinikainen Outi Krause 《Topics in Catalysis》2009,52(8):1070-1078
The effect of sulfur on biomass gasification gas clean-up over ZrO2, Y2O3–ZrO2 and SiO2–ZrO2 catalysts was examined. Experiments were carried out at the temperature range of 600–900 °C with sulfur free and 100 ppm
H2S containing simulated gasification gas feeds. A mixture of toluene and naphthalene was used as a tar model compound. Results
revealed that the sulfur addition affected positively on the catalyst properties mainly at 600 and 700 °C: over Y2O3–ZrO2 and ZrO2 sulfur addition improved naphthalene and ammonia conversion. However, over SiO2–ZrO2 no clear effect with H2S addition was observed. The effect of sulfur addition on the catalyst properties was connected to the formation of SO2 from H2S when oxygen was available. The intensity of the sulfur effect increased with the Lewis basicity strength of the catalysts.
This indicates that the sulfur adsorption has a role in generating new type of active sites and/or plays role in changing
the redox properties of the zirconia. Since the biomass gasification gas contains usually significant amounts of H2S the sulfur tolerance of the zirconia based catalysts is a remarkable benefit. 相似文献
8.
This study investigated the removal of ammonia in wastewater by an electrochemical method using titanium electrodes coated
with ruthenium and iridium (RuO2–IrO2–TiO2/Ti) with low chlorine evolution over-voltage. The effects of operating parameters, including chloride ion concentration,
current density and initial pH, were also investigated. The results were evaluated primarily by considering the efficiency
of the elimination of NH4+-N. The removal of ammonia by electrochemical oxidation mainly resulted from the indirect oxidation effect of chlorine/hypochlorite
produced during electrolysis. The direct anodic oxidation efficiency of ammonia was less than 5%, and the current efficiency
was less than 10%. The ammonia removal followed pseudo-first-order kinetics. The electrochemical process can be applied successfully
as a final polishing step, or as an alternative method to biological nitrification. The process seems to be most beneficial
for small coastal cities 相似文献
9.
S. S. Ordan’yan D. D. Nesmelov S. V. Vikhman 《Refractories and Industrial Ceramics》2009,50(5):391-393
Experiments and calculations have been applied to the structure of the triple eutectic system SiC–W2B5–LaB6(T
eu = 1900 ± 40°C), composition in mol.%: 10 LaB6, 44 SiC, 46 W2B5, error ±2–3%, which opens up prospects for making ceramic materials for various purposes. 相似文献
10.
Zeolite Mazzite (MAZ) analogue was synthesized directly using piperazine as a structure directing agent. The reactive gel
composition used was (5.0–7.0) piperazine:(6.0–7.0) Na2O:Al2O3:20.0SiO2:400H2O. Using this composition, the reaction time was shortened greatly to 4 days and the crystallization time was reduced as well.
The DTA data showed that piperazine, in as-synthesized zeolite omega decomposed easily. The decomposition of the piperazine
occurred at 400–480°C. NH3-TPD analysis proved that zeolite H-omega from piperazine had strong surface acidity with ammonia desorption temperature up
to 590°C. 相似文献
11.
Ying‐Chien Chung Yu‐Yen Lin Ching‐Ping Tseng 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2004,79(6):570-577
The removal of high concentrations of H2S from waste gases containing mixtures of H2S and NH3 was studied using the pilot‐scale biofilter. Granular activated carbon (GAC), selected as support material in this study, demonstrated its high adsorption capacity for H2S and good gas distribution. Extensive tests to determine removal characteristics, removal efficiency, and removal capacity of high H2S levels and coexisting NH3 in the system were performed. In seeking the appropriate operating conditions, the response surface methodology (RSM) was employed. H2S removal capacities were evaluated by the inoculated bacteria (biological conversion) and BDST (Bed Depth Service Time) methods (physical adsorption). An average 98% removal efficiency for 0.083–0.167 mg dm?3 of H2S and 0.004–0.021 mg dm?3 of NH3 gases was achieved during the operational period because of rapid physical adsorption by GAC and subsequently an effective biological regeneration of GAC by inoculated Pseudomonas putida CH11 and Arthrobacter oxydans CH8. The results showed that H2S removal efficiency for the system was not affected by inlet NH3 concentrations. In addition, no acidification was observed in the BAC biofilter. High buffer capacity and low moisture demand were also advantages of this system. The maximal inlet loading and critical loading for the system were 18.9 and 7.7 g‐H2S m?3 h?1, respectively. The results of this study could be used as a guide for the further design and operation of industrial‐scale systems. Copyright © 2004 Society of Chemical Industry 相似文献
12.
A. M. Starik B. I. Lukhovitskii N. S. Titova 《Combustion, Explosion, and Shock Waves》2008,44(3):249-261
The possibility of intensification of ignition of a methane-oxygen mixture in a supersonic flow behind the front of an oblique
shock wave by means of excitation of O2 molecules to the states a
1Δg and b
1Σg+ in an electric discharge is discussed. Through numerical simulations, activation of O2 molecules by an electric discharge is demonstrated to speed up chain reactions in the CH4-O2 mixture and to reduce the induction-zone length. Even a small amount of energy input to O2 molecules in the discharge (≈3·0−2 J/cm3) can reduce the ignition-delay length by a factor of hundreds and initiate combustion at distances of ≈1 m from the discharge
zone at comparatively low temperatures of the gas behind the front (≈1000 K) and moderate pressures (≈105 Pa). Excitation of O2 molecules by an electric discharge is much more efficient than simple heating of the mixture.
__________
Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 3, pp. 3–16, May–June, 2008. 相似文献
13.
Nanoporous silica membrane without any pinholes and cracks was synthesized by organic templating method. The tetrapropylammoniumbromide
(TPABr)-templating silica sols were coated on tubular alumina composite support ( γ-Al2O3/ α-Al2O3 composite) by dip coating and then heat-treated at 550 °C. By using the prepared TPABr templating silica/alumina composite
membrane, adsorption and membrane transport experiments were performed on the CO2/N2, CO2/H2 and CH4/H2 systems. Adsorption and permeation by using single gas and binary mixtures were measured in order to examine the transport
mechanism in the membrane. In the single gas systems, adsorption characteristics on the α-Al2O3 support and nanoporous unsupport (TPABr templating SiO2/ γ-Al2O3 composite layer without α-Al2O3 support) were investigated at 20–40 °C conditions and 0.0–1.0 atm pressure range. The experimental adsorption equilibrium
was well fitted with Langmuir or/and Langmuir-Freundlich isotherm models. The α-Al2O3 support had a little adsorption capacity compared to the unsupport which had relatively larger adsorption capacity for CO2 and CH4. While the adsorption rates in the unsupport showed in the order of H2> CO2> N2> CH4 at low pressure range, the permeate flux in the membrane was in the order of H2≫N2> CH4> CO2. Separation properties of the unsupport could be confirmed by the separation experiments of adsorbable/non-adsorbable mixed
gases, such as CO2/H2 and CH4/H2 systems. Although light and non-adsorbable molecules, such as H2, showed the highest permeation in the single gas permeate experiments, heavier and strongly adsorbable molecules, such as
CO2 and CH4, showed a higher separation factor (CO2/H2=5-7, CH4/H2=4-9). These results might be caused by the surface diffusion or/and blocking effects of adsorbed molecules in the unsupport.
And these results could be explained by surface diffusion.
This paper is dedicated to Professor Hyun-Ku Rhee on the occasion of his retirement from Seoul National University. 相似文献
14.
G. A. Makhov 《Combustion, Explosion, and Shock Waves》2007,43(6):628-635
A method for estimating absolute concentrations of C2H5 and H radicals in hydrocarbon diffusion flames is proposed and substantiated. Concentration profiles of C2H5 and H on the flame axis are obtained. In the method proposed, the concentration of C2H5 is determined from the equality of two quantities — the rate of loss of n-butane by diffusion and the rate of its formation by recombination of two C2H5 radicals. The concentration of H radicals is determined from the relation between the ratio C2H5/H and experimental profiles of C2H4, C2H6, and O2.
__________
Translated from Fizika Goreniya i Vzryva, Vol. 43, No. 6, pp. 13–20, November–December, 2007. 相似文献
15.
Synthetic spinels of the system MgO-Cr2O3-Al2O3-Fe2O3 are considered and the desirability of organizing their production for the refractory industry is demonstrated.
Translated from Novye Ogneupory, No. 6, pp. 32–35, June 2008. 相似文献
16.
V. A. Lomonosov A. S. Panasyugin O. L. Smorygo V. A. Mikutskii A. N. Romashko S. F. Tikhov V. S. Sadykov 《Catalysis in Industry》2010,2(4):387-392
The results from investigating the influence of temperature, concentration, and flow rate on the catalytic oxidation of vapors
of volatile organic compounds (VOCs) in the presence of Pd/γ-Al2O3 catalyst on cellular supports are presented. The activity of Pd/γ-Al2O3 catalysts on ceramic and metal monolith supports with a cellular structure during the catalytic neutralization of VOC (ethanol,
ethyl acetate) vapors under laboratory conditions was determined, and the most stable catalyst for the preliminary study of
a large batch was chosen. A pilot unit was created to test a large batch of cellular monolith catalyst in neutralizing VOC
vapors under conditions of flexographic production. It was established that a high rate of conversion (> 99 %) was achieved
for VOC concentrations of 0.5 g/m3 at space velocities of up to ∼104 h−1, and for VOC concentrations of 5.0 g/m3 at space velocities of up to ∼5 × 105 h−1. The change in the activity of the catalysts on metal (nickel alloyed by aluminum) and ceramic cellular supports in service
was investigated. After 300–500 min of operation, virtually complete deactivation of catalyst on a metal support was observed,
accompanied by the formation of nickel oxide and acetate. Pilot unit tests with catalyst on cellular supports having a volume
of 14.5 l in neutralizing the ventilation exhausts of flexographic production confirmed the possibility of more than 90% conversion
at VOC concentrations of ∼0.1 g/m3 and more than 97% at VOC concentrations of over 1 g/m3. A consistently high conversion of VOC was observed during a 100 h test of the pilot unit. A system for recovering the heat
released during VOC oxidation lowers the operating costs of the pilot unit. 相似文献
17.
Amy J. Heston Debasish Banerjee Peter L. Rinaldi Claire A. Tessier 《Journal of Inorganic and Organometallic Polymers and Materials》2007,17(2):477-481
The by-product chlorophosphazenes obtained from the reaction of PCl5 and NH4Cl at ∼ 140°, have been characterized by 2D 31P–15N HMQC and DOSY NMR spectroscopy. These NMR spectra show that the byproducts are a very complex mixture.
CAT would like to thank Chris Allen for an being an important role model. By his actions, she learned that wanting to be both
a good scientist and a good parent need not be mutually exclusive. 相似文献
18.
E. Pousse P. A. Glaude R. Fournet F. Battin-Leclerc 《Combustion, Explosion, and Shock Waves》2010,46(2):132-139
In order to better understand the chemistry involved during the combustion of diesel fuel components, the structure of a laminar
lean premixed methane flame doped with indane has been investigated. This flame contains 7.1% (molar) of methane, 36.8% of
oxygen, and 0.90% of indane, corresponding to an equivalence ratio of 0.74 and a C9H10/CH4 ratio of 12.75%, with argon used as a dilutant. The flame has been stabilized on a burner at a pressure of 6.7 kPa, with
the gas velocity at the burner exit equal to 49.2 cm/sec at 333 K. Quantified species include usual methane combustion products
C0–C2, but also eleven C3–C5 hydrocarbons and three C1–C3 oxygenated compounds, as well as 17 aromatic products, namely benzene, toluene, phenylacetylene, styrene, ethylbenzene, xylenes,
trimethylbenzenes, ethyltoluenes, indene, methylindane, methylindene, naphthalene, phenol, benzaldehyde, and benzofuran. The
temperature has been measured by a PtRh(6%)-PtRh(30%) thermocouple settled inside the enclosure: from 800 K close to the burner
up to 2000 K in the burned gases. 相似文献
19.
M. Benabdellah A. Ousslim B. Hammouti A. Elidrissi A. Aouniti A. Dafali K. Bekkouch M. Benkaddour 《Journal of Applied Electrochemistry》2007,37(7):819-826
The inhibiting effect of two organic copolymers namely poly(vinyl caprolactone-co-vinyl pyridine) (PVCVP) and poly(vinyl imidazol-co-vinyl
pyridine) (PVIVP) on the corrosion of steel in phosphoric acid was investigated at various temperatures. The study was carried
out by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and weight loss measurements. Inhibition
efficiency (E %) increased with polymer concentration to attain 85% at 10−4 M for PVIVP. Adsorption of polymers on the steel surface in 2 M H3PO4 followed the Langmuir isotherm model. EIS measurements show that the dissolution of steel occurs under activation control.
Polarisation curves indicate that the tested polymers functioned as cathodic inhibitors. E % values obtained from various methods used are in good agreement with each other. The temperature effect on the corrosion
behaviour of steel in 2 M H3PO4 in the presence and absence of the inhibitor was studied in the temperature range 298–338 K. The adsorption free energy (ΔG
o
ads) and the activation parameters (E
a, , ΔS
o
a) for the steel dissolution reaction in the presence of polymer were determined. 相似文献
20.
Heqin Guo Debao Li Haicheng Xiao Jianli Zhang Wenhuai Li Yuhan Sun 《Korean Journal of Chemical Engineering》2009,26(3):902-906
A series of SBA-15 supported H3PMo12O40 catalysts were prepared for the one-step oxidation of methanol to dimethoxymethane (DMM). The evaluation and characterization
revealed that higher DMM selectivity obtained on the incipient wetness impregnation (IM) catalyst was related to the instability
of H3PMo12O40 on it. Raman spectra showed that 12-molybdophosphoric acid was more stable on the direct synthesis (DS) catalyst than on
the IM catalyst and the existence of SBA-15 support enhanced the stability of H3PMo12O40. Moreover, higher H3PMo12O40 loading resulted in more acid sites and low DMM selectivity, furthermore the thermal pretreatment on H3PMo12O40 influenced its structure and thus affected DMM selectivity.
This paper was presented at the 7
th
Korea-China Workshop on Clean Energy Technology held at Taiyuan, China, June 26–28, 2008. 相似文献