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Sample records for oxidative desulfurization ods

  1. Deep catalytic oxidative desulfurization (ODS) of dibenzothiophene (DBT) with oxalate-based deep eutectic solvents (DESs).

    Science.gov (United States)

    Lü, Hongying; Li, Pengcheng; Deng, Changliang; Ren, Wanzhong; Wang, Shunan; Liu, Pan; Zhang, Han

    2015-07-07

    An oxalate-based DES with a tetrabutyl ammonium chloride and oxalate acid molar ratio of 1/2 (TBO1 : 2) exhibited high activity in oxidative desulfurization (ODS) of dibenzothiophene (DBT) under mild reaction conditions. It is potentially a promising and highly environmentally friendly approach for desulfurization of fuels.

  2. L-proline-based deep eutectic solvents (DESs) for deep catalytic oxidative desulfurization (ODS) of diesel.

    Science.gov (United States)

    Hao, Lingwan; Wang, Meiri; Shan, Wenjuan; Deng, Changliang; Ren, Wanzhong; Shi, Zhouzhou; Lü, Hongying

    2017-10-05

    A series of L-proline-based DESs was prepared through an atom economic reaction between L-proline (L-Pro) and four different kinds of organic acids. The DESs were characterized by Fourier transform infrared spectroscopy (FT-IR), H nuclear magnetic resonance ( 1 HNMR), cyclic voltammogram (CV) and the Hammett method. The synthesized DESs were used for the oxidative desulfurization and the L-Pro/p-toluenesultonic acid (L-Pro/p-TsOH) system shows the highest catalytic activity that the removal of dibenzothiophene (DBT) reached 99% at 60°C in 2h, which may involve the dual activation of the L-Pro/p-TsOH. The acidity of four different L-proline-based DESs was measured and the results show that it could not simply conclude that the correlation between the acidity of DESs and desulfurization capability was positive or negative. The electrochemical measurements evidences and recycling experiment indicate a good stability performance of L-Pro/p-TsOH in desulfurization. This work will provide a novel and potential method for the deep oxidation desulfurization. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Ultrasound-assisted oxidative desulfurization of bitumen

    Science.gov (United States)

    Kamal, Wan Mohamad Ikhwan bin Wan; Okawa, Hirokazu; Kato, Takahiro; Sugawara, Katsuyasu

    2017-07-01

    Bitumen contains a high percentage of sulfur (about 4.6 wt %). A hydrodesulfurization method is used to remove sulfur from bitumen. The drawback of this method is the requirement for a high temperature of >300 °C. Most of the sulfur in bitumen exists as thiophene. Oxidative desulfurization (ODS), involving oxidizing sulfur using H2O2, then removing it using NaOH, allows the removal of sulfur in thiophene at low temperatures. We removed sulfur from bitumen using ODS treatment under ultrasound irradiation, and 52% of sulfur was successfully removed. Additionally, the physical action of ultrasound assisted the desulfurization of bitumen, even at low H2O2 concentrations.

  4. Oxidative desulfurization: kinetic modelling.

    Science.gov (United States)

    Dhir, S; Uppaluri, R; Purkait, M K

    2009-01-30

    Increasing environmental legislations coupled with enhanced production of petroleum products demand, the deployment of novel technologies to remove organic sulfur efficiently. This work represents the kinetic modeling of ODS using H(2)O(2) over tungsten-containing layered double hydroxide (LDH) using the experimental data provided by Hulea et al. [V. Hulea, A.L. Maciuca, F. Fajula, E. Dumitriu, Catalytic oxidation of thiophenes and thioethers with hydrogen peroxide in the presence of W-containing layered double hydroxides, Appl. Catal. A: Gen. 313 (2) (2006) 200-207]. The kinetic modeling approach in this work initially targets the scope of the generation of a superstructure of micro-kinetic reaction schemes and models assuming Langmuir-Hinshelwood (LH) and Eley-Rideal (ER) mechanisms. Subsequently, the screening and selection of above models is initially based on profile-based elimination of incompetent schemes followed by non-linear regression search performed using the Levenberg-Marquardt algorithm (LMA) for the chosen models. The above analysis inferred that Eley-Rideal mechanism describes the kinetic behavior of ODS process using tungsten-containing LDH, with adsorption of reactant and intermediate product only taking place on the catalyst surface. Finally, an economic index is presented that scopes the economic aspects of the novel catalytic technology with the parameters obtained during regression analysis to conclude that the cost factor for the catalyst is 0.0062-0.04759 US $ per barrel.

  5. Oxidative desulfurization: Kinetic modelling

    International Nuclear Information System (INIS)

    Dhir, S.; Uppaluri, R.; Purkait, M.K.

    2009-01-01

    Increasing environmental legislations coupled with enhanced production of petroleum products demand, the deployment of novel technologies to remove organic sulfur efficiently. This work represents the kinetic modeling of ODS using H 2 O 2 over tungsten-containing layered double hydroxide (LDH) using the experimental data provided by Hulea et al. [V. Hulea, A.L. Maciuca, F. Fajula, E. Dumitriu, Catalytic oxidation of thiophenes and thioethers with hydrogen peroxide in the presence of W-containing layered double hydroxides, Appl. Catal. A: Gen. 313 (2) (2006) 200-207]. The kinetic modeling approach in this work initially targets the scope of the generation of a superstructure of micro-kinetic reaction schemes and models assuming Langmuir-Hinshelwood (LH) and Eley-Rideal (ER) mechanisms. Subsequently, the screening and selection of above models is initially based on profile-based elimination of incompetent schemes followed by non-linear regression search performed using the Levenberg-Marquardt algorithm (LMA) for the chosen models. The above analysis inferred that Eley-Rideal mechanism describes the kinetic behavior of ODS process using tungsten-containing LDH, with adsorption of reactant and intermediate product only taking place on the catalyst surface. Finally, an economic index is presented that scopes the economic aspects of the novel catalytic technology with the parameters obtained during regression analysis to conclude that the cost factor for the catalyst is 0.0062-0.04759 US $ per barrel

  6. Oxidative Desulfurization of Gasoline by Ionic Liquids Coupled with Extraction by Organic Solvents

    OpenAIRE

    Abro, Rashid; Gao, Shurong; Chen, Xiaochun; Yu, Guangren; Abdeltawab, Ahmed A.; Al-Deyab, Salem S.

    2016-01-01

    In this work, desulfurization of real fluidized catalytic cracking (FCC) gasoline was investigated in dual steps; first in oxidative desulfurization (ODS) using imidazolium and pyrrolidonium based Brønsted acidic ionic liquids (ILs) as solvent and catalyst and hydrogen peroxide as oxidant. In second step, extractive desulfurization took place using organic solvents of furfural, furfural alcohol and ethylene glycol. Variety of factors such as temperature, time, mass ratio of oil/ILs and regene...

  7. Rare earth oxides in gaseous desulfurization

    International Nuclear Information System (INIS)

    Kay, D.A.R.; Wilson, W.G.

    1988-01-01

    Phase stability diagrams are used to predict the abilities of lanthanum and cerium oxides to desulfurize coal gasification products in the temperature range 800-1000 C. Results of desulfurization studies in laboratory fixed bed reactors illustrate the effects of sorbent preparation, input gas quality and temperature, on the desulfurization reaction: 2CeO( 2 - x )(s) + H 2 S(g) + (1-2x)H 2 = Ce 2 O 2 S(s) + 2(1 - x)H 2 O(g). The results of desulfurization/oxidation regeneration cycles are also reported

  8. Effect of gasoline composition on oxidative desulfurization using a phosphotungstic acid/activated carbon catalyst with hydrogen peroxide

    International Nuclear Information System (INIS)

    Xiao, Jing; Wu, Luoming; Wu, Ying; Liu, Bing; Dai, Lu; Li, Zhong; Xia, Qibin; Xi, Hongxia

    2014-01-01

    Highlights: • Concerned with the question why ODS catalyst is not effective for real gasoline. • Reported the strong inhibiting effect of gasoline composition on ODS for the 1st time. • ODS reactivity is suggested to be determined by partial charge on S atom of thiophene. • Proposed approaches to improve ODS selectivity for real gasoline desulfurization. - Abstract: This work is concerned with the question of why oxidative desulfurization (ODS) catalyst that show good catalytic performance for ODS of model gasoline thiophenic compounds is not effective for real gasoline. For the first time, the effects of gasoline composition on ODS using a phosphotungstic acid/activated carbon (HPW/AC) catalyst with H 2 O 2 were investigated. ODS of thiophene, one of the most difficult thiophenic compounds to be oxidized, was studied in a model fuel system, where a high thiophene conversion rate of 90% could be reached in 2 h at 90 °C. However, when applying the ODS to a real gasoline, the ODS conversion rate decreased to only 32%, suggesting a strong inhibiting effect of gasoline composition on ODS. The ODS studies in different model fuels suggested that the inhibiting effect can be ascribed to the competitive adsorption and oxidation with the presence of the alkenes and alkylated aromatic hydrocarbons in real gasoline. The active pi-electrons in alkenes and alkyl groups in alkylated aromatic hydrocarbons may react with polyoxoperoxo species or peroxo-metallate complexes formed by phosphotungstic acid–H 2 O 2 interaction. Additionally, it was indicated that the ODS selectivity followed the order of benzothiophene > trimethylthiophene > dimethylthiophene ∼ methylthiophene > thiophene, suggesting the partial charge on the electron-rich sulfur atom may play a decisive role for its oxidation reactivity. To mitigate the inhibiting effect of gasoline composition on ODS, we propose (a) implementation of selective separation–oxidation processes; (b) choice of suitable

  9. Oxidative desulfurization of tire pyrolysis oil

    OpenAIRE

    Ahmad Shahzad; Ahmad Muhammad Imran; Naeem Khawar; Humayun Muhammad; Sebt-E-Zaeem; Faheem Farrukh

    2016-01-01

    This paper presents a low cost method for the purification of oils obtained from the pyrolysis of used tires. Oxidative desulfurization is a promising route for purification of tire pyrolysis oils as hydro-desulfurization may not be affordable for small scale industries. Different additives and acids have been employed for the enhancement of properties of pyrolytic oils. The experimental conditions were kept identical throughout, i.e. atmospheric pressure a...

  10. Ultrasound-Assisted Oxidative Desulfurization of Diesel

    OpenAIRE

    Niran K. Ibrahim; Walla A. Noori; Jaffar M. Khasbag

    2016-01-01

    Due to the dramatic environmental impact of sulfur emissions associated with the exhaust of diesel engines, last environmental regulations for ultra-low-sulfur diesel require a very deep desulfurization (up to 15 ppm), which cannot be met by the conventional hydrodesulfurization units alone. The proposed method involves a batch ultrasound-assisted oxidative desulfurization (UAODS) of a previously hydrotreated diesel (containing 480 ppm sulfur) so as to convert the residual sulfur-bearing comp...

  11. Oxidative desulfurization of tire pyrolysis oil

    Directory of Open Access Journals (Sweden)

    Ahmad Shahzad

    2016-01-01

    Full Text Available This paper presents a low cost method for the purification of oils obtained from the pyrolysis of used tires. Oxidative desulfurization is a promising route for purification of tire pyrolysis oils as hydro-desulfurization may not be affordable for small scale industries. Different additives and acids have been employed for the enhancement of properties of pyrolytic oils. The experimental conditions were kept identical throughout, i.e. atmospheric pressure and 50°C temperature for comparison of performance of various additives. The use of hydrogen peroxide-acetic acid mixture (10 wt.% was found more economical and effective in desulfurization and improvement of fuel properties of sample oils. The contribution of sulfuric acid in desulfurization and decreasing viscosity was also satisfactory but due to high price of concentrated sulfuric acid its use may not be economical. Calcium oxide and Fuller’s earth was not found to be effective in desulfurization. Results indicate that oxidative desulfurization could render tire pyrolysis oils suitable for blending as heating fuel.

  12. The oxidation and corrosion of ODS alloys

    Science.gov (United States)

    Lowell, Carl E.; Barrett, Charles A.

    1990-01-01

    The oxidation and hot corrosion of high temperature oxide dispersion strengthened (ODS) alloys are reviewed. The environmental resistance of such alloys are classified by oxide growth rate, oxide volatility, oxide spalling, and hot corrosion limitations. Also discussed are environmentally resistant coatings for ODS materials. It is concluded that ODS NiCrAl and FeCrAl alloys are highly oxidation and corrosion resistant and can probably be used uncoated.

  13. Oxidation And Hot Corrosion Of ODS Alloy

    Science.gov (United States)

    Lowell, Carl E.; Barrett, Charles A.

    1993-01-01

    Report reviews oxidation and hot corrosion of oxide-dispersion-strengthened (ODS) alloys, intended for use at high temperatures. Classifies environmental resistances of such alloys by rates of growth of oxides, volatilities of oxides, spalling of oxides, and limitations imposed by hot corrosion. Also discusses environmentally resistant coatings for ODS materials. Concludes ODS NICrAl and FeCrAl alloys highly resistant to oxidation and corrosion and can be used uncoated.

  14. High temperature oxidation behavior of ODS steels

    Science.gov (United States)

    Kaito, T.; Narita, T.; Ukai, S.; Matsuda, Y.

    2004-08-01

    Oxide dispersion strengthened (ODS) steels are being developing for application as advanced fast reactor cladding and fusion blanket materials, in order to allow increased operation temperature. Oxidation testing of ODS steel was conducted under a controlled dry air atmosphere to evaluate the high temperature oxidation behavior. This showed that 9Cr-ODS martensitic steels and 12Cr-ODS ferritic steels have superior high temperature oxidation resistance compared to 11 mass% Cr PNC-FMS and 17 mass% Cr ferritic stainless steel. This high temperature resistance is attributed to earlier formation of the protective α-Cr 2O 3 on the outer surface of ODS steels.

  15. Ultrasound-Assisted Oxidative Desulfurization of Diesel

    Directory of Open Access Journals (Sweden)

    Niran K. Ibrahim

    2016-11-01

    Full Text Available Due to the dramatic environmental impact of sulfur emissions associated with the exhaust of diesel engines, last environmental regulations for ultra-low-sulfur diesel require a very deep desulfurization (up to 15 ppm, which cannot be met by the conventional hydrodesulfurization units alone. The proposed method involves a batch ultrasound-assisted oxidative desulfurization (UAODS of a previously hydrotreated diesel (containing 480 ppm sulfur so as to convert the residual sulfur-bearing compounds into their corresponding highly polar oxides, which can be eliminated easily by extraction with a certain highly polar solvent. The oxidizing system utilized was H2O2 as an oxidant, CH3COOH as a promoter, with FeSO4 as a catalyst; whereas acetonitrile was used as extractant. The major influential parameters related to UAODS process have been investigated, namely: ratio of oxidant/fuel, ratio of the promoter/oxidant, dose of catalyst, reaction temperature, and intensity of ultrasonic waves. Kinetics of the reaction has been also studied; it was observed that the UAODS of diesel fuels fitted pseudo-first-order kinetics under the best experimental conditions, whereas values of the apparent rate constant and activation energy were 0.373 min-1 and 24 KJ/mol, respectively. The oxidation treatment, in combination with ultrasonic irradiation, revealed a synergistic effect for diesel desulfurization. The experimental results showed that sulfur removal efficiency could amount to 98% at mild operating conditions (70 ○C and 1 bar. This indicates that the process is efficient and promising for the production of ultra-low-sulfur diesel fuels.

  16. Gas-exfoliated porous monolayer boron nitride for enhanced aerobic oxidative desulfurization performance

    Science.gov (United States)

    Wu, Yingcheng; Wu, Peiwen; Chao, Yanhong; He, Jing; Li, Hongping; Lu, Linjie; Jiang, Wei; Zhang, Beibei; Li, Huaming; Zhu, Wenshuai

    2018-01-01

    Hexagonal boron nitride has been regarded to be an efficient catalyst in aerobic oxidation fields, but limited by the less-exposed active sites. In this contribution, we proposed a simple green liquid nitrogen gas exfoliation strategy for preparation of porous monolayer nanosheets (BN-1). Owing to the reduced layer numbers, decreased lateral sizes and artificially-constructed pores, increased exposure of active sites was expected, further contributed to an enhanced aerobic oxidative desulfurization (ODS) performance up to ˜98% of sulfur removal, achieving ultra-deep desulfurization. This work not only introduced an excellent catalyst for aerobic ODS, but also provided a strategy for construction of some other highly-efficient monolayer two-dimensional materials for enhanced catalytic performance.

  17. Synthesis and application of different phthalocyanine molecular sieve catalyst for oxidative desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Na; Li, Siwen; Wang, Jinyi; Zhang, Ronglan [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry & Material Science, Northwest University, Xi’an 710069, Shaanxi (China); Composites Research Institute, Weinan Normal University, Weinan 714000 (China); Gao, Ruimin [Research Institute of Shaanxi Yanchang Petroleum Group Corp. Ltd., Xi’an 710075 (China); Composites Research Institute, Weinan Normal University, Weinan 714000 (China); Zhao, Jianshe, E-mail: jszhao@nwu.edu.cn [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry & Material Science, Northwest University, Xi’an 710069, Shaanxi (China); Composites Research Institute, Weinan Normal University, Weinan 714000 (China); Wang, Junlong [Research Institute of Shaanxi Yanchang Petroleum Group Corp. Ltd., Xi’an 710075 (China); Composites Research Institute, Weinan Normal University, Weinan 714000 (China)

    2015-05-15

    M{sub 2}(PcAN){sub 2} (M=Fe, Co, Ni, Cu, Zn and Mn) anchored onto W-HZSM-5 (M{sub 2}(PcAN){sub 2}–W-HZSM-5) or the M{sub 2}(PcTN){sub 2} doping W-HZSM-5 (M{sub 2}(PcTN){sub 2}/W-HZSM-5) were prepared and their catalytic performances were tested for oxidative desulfurization in the presence of oxygen. Thiophene (T), benzothiophene (BT), and dibenzothiophene (DBT) were considered as sulfur compounds. Among zeolite-based catalysts, the Cu{sub 2}(PcAN){sub 2}–W-HZSM-5 and Cu{sub 2}(PcTN){sub 2}/W-HZSM-5 showed superior desulfurization performance and the activity of selectivity followed the order: T>BT>DBT. The effects of phthalocyanine concentration were studied by UV–Vis and calcination temperature was obtained by TG-DSC for Cu{sub 2}(PcTN){sub 2}/W-HZSM-5. Catalysts were characterized by EA, IR, XRD, SEM, TEM, ICP, and N{sub 2} adsorption. Reaction time, temperature and the amount of catalyst were investigated as the important parameters for optimization of the reaction. Furthermore, a possible process of oxidative desulfurization and the reaction products were proposed. - Graphical abstract: The ODS reaction schematic shows the reaction mechanism of ultra-deep desulfurization. The sulfur compounds are oxidized to their corresponding sulfoxides or sulfones through the use of oxygen and catalysts. The reaction process of ultra-deep desulfurization. - Highlights: • A kind of novel catalyst for deep desulfurization was synthesized. • Cu{sub 2}(PcAN){sub 2}–W-HZSM-5 exhibits excellent catalytic performance for desulfurization. • The reaction conditions that affect desulfurization efficiency are investigated. • The reaction process of model sulfur compounds is proposed.

  18. Synthesis and application of different phthalocyanine molecular sieve catalyst for oxidative desulfurization

    International Nuclear Information System (INIS)

    Zhao, Na; Li, Siwen; Wang, Jinyi; Zhang, Ronglan; Gao, Ruimin; Zhao, Jianshe; Wang, Junlong

    2015-01-01

    M 2 (PcAN) 2 (M=Fe, Co, Ni, Cu, Zn and Mn) anchored onto W-HZSM-5 (M 2 (PcAN) 2 –W-HZSM-5) or the M 2 (PcTN) 2 doping W-HZSM-5 (M 2 (PcTN) 2 /W-HZSM-5) were prepared and their catalytic performances were tested for oxidative desulfurization in the presence of oxygen. Thiophene (T), benzothiophene (BT), and dibenzothiophene (DBT) were considered as sulfur compounds. Among zeolite-based catalysts, the Cu 2 (PcAN) 2 –W-HZSM-5 and Cu 2 (PcTN) 2 /W-HZSM-5 showed superior desulfurization performance and the activity of selectivity followed the order: T>BT>DBT. The effects of phthalocyanine concentration were studied by UV–Vis and calcination temperature was obtained by TG-DSC for Cu 2 (PcTN) 2 /W-HZSM-5. Catalysts were characterized by EA, IR, XRD, SEM, TEM, ICP, and N 2 adsorption. Reaction time, temperature and the amount of catalyst were investigated as the important parameters for optimization of the reaction. Furthermore, a possible process of oxidative desulfurization and the reaction products were proposed. - Graphical abstract: The ODS reaction schematic shows the reaction mechanism of ultra-deep desulfurization. The sulfur compounds are oxidized to their corresponding sulfoxides or sulfones through the use of oxygen and catalysts. The reaction process of ultra-deep desulfurization. - Highlights: • A kind of novel catalyst for deep desulfurization was synthesized. • Cu 2 (PcAN) 2 –W-HZSM-5 exhibits excellent catalytic performance for desulfurization. • The reaction conditions that affect desulfurization efficiency are investigated. • The reaction process of model sulfur compounds is proposed

  19. Desulfurization of AL-Ahdab Crude Oil using Oxidative Processes

    OpenAIRE

    Neran Khalel Ibrahim; Saja Mohsen Jabbar

    2015-01-01

    Two different oxidative desulfurization strategies based on oxidation/adsorption or oxidation/extraction were evaluated for the desulfurization of AL-Ahdab (AHD) sour crude oil (3.9wt% sulfur content). In the oxidation process, a homogenous oxidizing agent comprising of hydrogen peroxide and formic acid was used. Activated carbons were used as sorbent/catalyst in the oxidation/adsorption process while acetonitrile was used as an extraction solvent in the oxidation/extraction process. For the ...

  20. Utilization of a by-product produced from oxidative desulfurization process over Cs-mesoporous silica catalysts.

    Science.gov (United States)

    Kim, Hyeonjoo; Jeong, Kwang-Eun; Jeong, Soon-Yong; Park, Young-Kwon; Kim, Do Heui; Jeon, Jong-Ki

    2011-02-01

    We investigated the use of Cs-mesoporous silica catalysts to upgrade a by-product of oxidative desulfurization (ODS). Cs-mesoporous silica catalysts were characterized through N2 adsorption, XRD, CO2-temperature-programmed desorption, and XRF. Cs-mesoporous silica prepared by the direct incorporation method showed higher catalytic performance than a Cs/MCM-41 catalyst by impregnation method for the catalytic decomposition of sulfone compounds produced from ODS process.

  1. Oxidative desulfurization of model diesel via dual activation by a protic ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Lü, Hongying, E-mail: hylv@ytu.edu.cn; Wang, Shunan; Deng, Changliang; Ren, Wanzhong; Guo, Baocun

    2014-08-30

    Highlights: • A protic ionic liquid, [Hnmp]HCOO, was used as in ODS. • The mechanism of ODS was involved in dual activation by the PIL. • The [Hnmp]HCOO exhibited high catalytic activity in ODS. • The amounts of PILs and oxidant dosage play vital roles in desulfurization system. • This system can be recycled five times with an unnoticeable decrease in activity. - Abstract: A novel and green carboxylate-anion-based protic ionic liquid (PIL), [Hnmp]HCOO, was prepared through a simple and atom economic neutralization reaction between N-methyl-2-pyrrolidonium (NMP) and formic acids. Both FT-IR spectra and {sup 1}H NMR confirmed its simple salt structure. [Hnmp]HCOO exhibited so high catalytic activity that the dibenzothiophene (DBT) removal reached 99% at 50 °C in 3 h under conditions of V{sub PIL}/V{sub model} {sub oil} = 1:10 and H{sub 2}O{sub 2}/DBT (O/S, molar ratio) = 5. The catalytic oxidation reactivity of S-compounds was found to be in the order of DBT > 4,6-dimethyldibenzothiophene (4,6-DMDBT) > benzothiophene (BT). The investigation on mechanism showed that oxidative desulfurization was realized through dual activation of PIL. Moreover, [Hnmp]HCOO can be recycled for five times with an unnoticeable decrease in desulfurization activity.

  2. Oxidative desulfurization of model diesel via dual activation by a protic ionic liquid

    International Nuclear Information System (INIS)

    Lü, Hongying; Wang, Shunan; Deng, Changliang; Ren, Wanzhong; Guo, Baocun

    2014-01-01

    Highlights: • A protic ionic liquid, [Hnmp]HCOO, was used as in ODS. • The mechanism of ODS was involved in dual activation by the PIL. • The [Hnmp]HCOO exhibited high catalytic activity in ODS. • The amounts of PILs and oxidant dosage play vital roles in desulfurization system. • This system can be recycled five times with an unnoticeable decrease in activity. - Abstract: A novel and green carboxylate-anion-based protic ionic liquid (PIL), [Hnmp]HCOO, was prepared through a simple and atom economic neutralization reaction between N-methyl-2-pyrrolidonium (NMP) and formic acids. Both FT-IR spectra and 1 H NMR confirmed its simple salt structure. [Hnmp]HCOO exhibited so high catalytic activity that the dibenzothiophene (DBT) removal reached 99% at 50 °C in 3 h under conditions of V PIL /V model oil = 1:10 and H 2 O 2 /DBT (O/S, molar ratio) = 5. The catalytic oxidation reactivity of S-compounds was found to be in the order of DBT > 4,6-dimethyldibenzothiophene (4,6-DMDBT) > benzothiophene (BT). The investigation on mechanism showed that oxidative desulfurization was realized through dual activation of PIL. Moreover, [Hnmp]HCOO can be recycled for five times with an unnoticeable decrease in desulfurization activity

  3. Desulfurization of AL-Ahdab Crude Oil using Oxidative Processes

    Directory of Open Access Journals (Sweden)

    Neran Khalel Ibrahim

    2015-07-01

    Full Text Available Two different oxidative desulfurization strategies based on oxidation/adsorption or oxidation/extraction were evaluated for the desulfurization of AL-Ahdab (AHD sour crude oil (3.9wt% sulfur content. In the oxidation process, a homogenous oxidizing agent comprising of hydrogen peroxide and formic acid was used. Activated carbons were used as sorbent/catalyst in the oxidation/adsorption process while acetonitrile was used as an extraction solvent in the oxidation/extraction process. For the oxidation/adsorption scheme, the experimental results indicated that the oxidation desulfurization efficiency was enhanced on using activated carbon as catalyst/sorbent. The effects of the operating conditions (contact time, temperature, mixing speed and sorbent dose on the desulfurization efficiency were examined. The desulfurization efficiency measured at the best operating conditions(optimum conditions: 60 , 500rpm, 60min contact time and sorbent dose of 0.7g AC/100 ml AHD crude, was 32.8% corresponding to a sulfur content of 2.6 wt%. Applying the same optimum operating conditions and at 3:1 solvent/oil ratio, the oxidation/extraction method gave comparable desulfurization efficiency of 31.5%.

  4. Desulfurization of Diesel Fuel by Oxidation and Solvent Extraction

    OpenAIRE

    Wadood Taher Mohammed; Raghad Fareed Kassim Almilly; Sheam Bahjat Abdulkareem Al-Ali

    2015-01-01

    This research presents a study in ultra-desulfurization of diesel fuel produced from conventional hydro desulfurization process, using oxidation and solvent extraction techniques. Dibenzothiophene (DBT) was the organosulfur compound that had been detected in sulfur removal. The oxidation process used hydrogen peroxide as an oxidant and acetic acid as homogeneous catalyst . The solvent extraction process used acetonitrile (ACN) and N-methyl – 2 - pyrrolidone (NMP) as extractants . Also the ef...

  5. Oxidative desulfurization of thiophene on TiO2/ZSM-12 zeolite

    OpenAIRE

    Santos,Marília Ramalho Figueiredo dos; Pedrosa,Anne Michelle Garrido; Souza,Marcelo José Barros de

    2016-01-01

    In this work the hydrothermal synthesis of ZSM-12 zeolite was performed, varying the MTEACl/SiO2 ratio, where the synthesis temperature was 140 ºC and the crystallization time was 144 hours. The catalysts were characterized by XRD, FTIR and TG. TiO2/ZSM-12 catalysts were used with titanium ions concentrations of 5, 10 and 15%. The oxidative desulfurization (ODS) reactions were performed using a model mixture containing n-heptane as solvent and thiophene as sulfur compound, H2O2 as an oxidizin...

  6. Bicarbonate-induced activation of H₂O₂ for metal-free oxidative desulfurization.

    Science.gov (United States)

    Bokare, Alok D; Choi, Wonyong

    2016-03-05

    Efficient oxidative desulfurization (ODS) of model oil containing dibenzothiophene (DBT) and aromatic thiophenic derivatives has been achieved at room temperature using hydrogen peroxide activation by inorganic bicarbonate (HCO3(-)). Using in-situ formation of peroxymonocarbonate as oxidant, the transformation of main model substrate DBT to corresponding DBT-sulfone was easily accomplished in biphasic reaction conditions. In the presence of water-acetonitrile polar phase, increasing the water content upto 50% decreased the extraction capacity more than 3 times, but ∼ 90% DBT oxidation was still achieved. The oxidizing capacity of bicarbonate catalyst was maintained during repeated ODS cycles, but DBT removal efficiency was critically dependent on the extraction capacity of the polar phase. Under heterogeneous reaction conditions, bicarbonate-modified ion-exchange resin achieved similar ODS activity compared to the homogeneous catalytic system. Additionally, the efficient formation of peroxymonocarbonate using gaseous CO2 precursor in alkaline conditions was also utilized for DBT oxidation. The present study proposes the NaHCO3/H2O2 catalytic system as an efficient and cheap metal-free alternative for the oxidative removal of aromatic sulfur compounds from fuel oil. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Mechanism of extractive/oxidative desulfurization using the ionic liquid inimidazole acetate: a computational study.

    Science.gov (United States)

    Wang, Hanlu; Xu, Mingsheng; Zhou, Rujin

    2017-02-01

    The dual role of the ionic liquid 1-butyl-3-methyl-imidazolium trifluoroacetic acid ([C 4 mim]TFA) as an extractant for thiophene (TH) and a catalyst for the oxidation of TH was explored at the molecular level by performing density functional theory (DFT) calculations. The calculated interaction energies demonstrated why [C 4 mim]TFA is a better extractant for thiophene sulfone (THO 2 ) than for TH. Two pathways were proposed for the oxidation of TH to THO 2 with [C 4 mim]TFA acting as a catalyst. In the dominant pathway, a peracid is formed which then oxidizes TH to the sulfoxide and sulfones. The presence of [C 4 mim]TFA was found to greatly reduce the barrier to the oxidative desulfurization (ODS) of TH using H 2 O 2 as an oxidant. Graphical Abstract Possible reaction mechanisms of TH with the aid of [C4mim]TFAᅟ.

  8. Efficient oxidative desulfurization (ODS) of model fuel with H{sub 2}O{sub 2} catalyzed by MoO{sub 3}/{gamma}-Al{sub 2}O{sub 3} under mild and solvent free conditions

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Yuhua; Li, Gang; Ning, Guiling [State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology (China)

    2011-01-15

    An efficient process to remove organic sulfur compounds from model fuel has been explored. Dibenzothiophene (DBT) and 4, 6-dimethyldibenzothiophene (4, 6-DMDBT) can be completely oxidized into their corresponding sulfones by H{sub 2}O{sub 2} over 14 wt.% MoO{sub 3}/{gamma}-Al{sub 2}O{sub 3} catalyst under mild conditions in 15 min. The effects of solvent, initial sulfide concentration, loading of MoO{sub 3} and amount of catalyst on oxidative removal of DBT were studied. The employments of solvents have decreased the reaction rate of DBT, which can be attributed to the competitive adsorption between the sulfide and solvent. The oxidative reactivity increases in the order of thiophene (Th) < benzothiophene (BT) < DBT < 4, 6-DMDBT. The catalyst can be regenerated by methanol washing at 333 K. (author)

  9. Hydrothermal Synthesis of MoO2 and Supported MoO2 Cata-lysts for Oxidative Desulfurization of Dibenzothiophene

    Institute of Scientific and Technical Information of China (English)

    Wang Danhong; Zhang Jianyong; Liu Ni; Zhao Xin; Zhang Minghui

    2014-01-01

    A novel method for obtaining spherical MoO2 nanoparticles and SiO2-Al2O3 supported MoO2 by hydrothermal reduction of Mo (VI) species was studied. The obtained MoO2 catalysts show very high catalytic activity in the oxidative desulfurization (ODS) process. The effect of hydrothermal temperature and crystallization temperature on ODS activity was investigated. The ODS activity of supported MoO2 catalysts with various MoO2 contents were also investigated. The mecha-nism for formation of MoO2 involving oxalic acid was proposed.

  10. Novel Oxidative Desulfurization of a Model Fuel with H2O2 Catalyzed by AlPMo12O40 under Phase Transfer Catalyst-Free Conditions

    OpenAIRE

    José da Silva, Márcio; Faria dos Santos, Lidiane

    2013-01-01

    A novel process was developed for oxidative desulfurization (ODS) in the absence of a phase transfer catalyst (PTC) using only Keggin heteropolyacids and their aluminum salts as catalysts. Reactions were performed in biphasic mixtures of isooctane/acetonitrile, with dibenzothiophene (DBT) as a model sulfur compound and hydrogen peroxide as the oxidant. Remarkably, only the AlPMo12O40-catalyzed reactions resulted in complete oxidation of DBT into DBT sulfone, which was totally extracted by ace...

  11. Economic analysis of ultrasound-assisted oxidative desulfurization

    OpenAIRE

    Anderson, K.; Atkins, M.P.; Borges, P; Chan, Z.P.; Rafeen, M.S.; Sebran, N.H.; van der Pool, E; Vleeming, J.H.

    2017-01-01

    Oxidative desulfurization is a method of removing sulfur from diesel fuel that has the potential to compete with conventional hydrodesulfurization processes in refineries. Ultrasound has been shown to greatly increase peroxide oxidation rates of sulfur compounds and can thereby enhance the technology. Through the use of conceptual design modeling, this article critically assesses a range of novel process options. Calculations show that the rate enhancement achieved by ultrasound can translate...

  12. Application of Two Cobalt-Based Metal-Organic Frameworks as Oxidative Desulfurization Catalysts.

    Science.gov (United States)

    Masoomi, Mohammad Yaser; Bagheri, Minoo; Morsali, Ali

    2015-12-07

    Two new porous cobalt-based metal-organic frameworks, [Co6(oba)5(OH)2(H2O)2(DMF)4]n · 5DMF (TMU-10) and [Co3(oba)3(O) (Py)0.5] n · 4DMF · Py (TMU-12) have been synthesized by solvothermal method using a nonlinear dicarboxylate ligand. Under mild reaction conditions, these compounds exhibited good catalytic activity and reusability in oxidative desulfurization (ODS) reaction of model oil which was prepared by dissolving dibenzothiophene (DBT) in n-hexane. FT-IR and Mass analysis showed that the main product of DBT oxidation is its corresponding sulfone, which was adsorbed on the surfaces of catalysts. The activation energy was obtained as 13.4 kJ/mol.

  13. Deep Desulfurization of Diesel Fuels with Plasma/Air as Oxidizing Medium, Diperiodatocuprate (III) as Catalyzer and Ionic Liquid as Extraction Solvent

    Science.gov (United States)

    Ban, Lili; Liu, Ping; Ma, Cunhua; Dai, Bin

    2013-12-01

    In this paper, the oxidative desulfurization (ODS) system is directly applied to deal with the catalytic oxidation of sulfur compounds of sulfur-containing model oil by dielectric barrier discharge (DBD) plasma in the presence of air plus an extraction step with the oxidation-treated fuel put over ionic liquid [BMIM]FeCl4 (1-butyl-3-methylimidazolium tetrachloroferrate). This new system exhibited an excellent desulfurization effect. The sulfur content of DBT in diesel oil decreased from 200 ppm to 4.92 ppm (S removal rate up to 97.5%) under the following optimal reaction conditions: air flow rate (ν) of 60 mL/min, amplitude of applied voltage (U) on DBD of 16 kV, input frequency (f) of 79 kHz, catalyst amount (ω) of 1.25 wt%, reaction time (t) of 10 min. Moreover, a high desulfurization rate was obtained during oxidation of benzothiophene (BT) or 4,6-DMDBT (4,6-dimethyl-dibenzothiophene) under the aforementioned conditions. The oxidation reactivity of different S compounds was decreased in the order of DBT, 4,6-DMDBT and BT. The remarkable advantage of the novel ODS system is that the desulfurization condition applies in the presence of air at ambient conditions without peroxides, aqueous solvent or biphasic oil-aqueous solution system.

  14. Deep Desulfurization of Diesel Fuels with Plasma/Air as Oxidizing Medium, Diperiodatocuprate (III) as Catalyzer and Ionic Liquid as Extraction Solvent

    International Nuclear Information System (INIS)

    Ban Lili; Liu Ping; Ma Cunhua; Dai Bin

    2013-01-01

    In this paper, the oxidative desulfurization (ODS) system is directly applied to deal with the catalytic oxidation of sulfur compounds of sulfur-containing model oil by dielectric barrier discharge (DBD) plasma in the presence of air plus an extraction step with the oxidation-treated fuel put over ionic liquid [BMIM]FeCl 4 (1-butyl-3-methylimidazolium tetrachloroferrate). This new system exhibited an excellent desulfurization effect. The sulfur content of DBT in diesel oil decreased from 200 ppm to 4.92 ppm (S removal rate up to 97.5%) under the following optimal reaction conditions: air flow rate (ν) of 60 mL/min, amplitude of applied voltage (U) on DBD of 16 kV, input frequency (f) of 79 kHz, catalyst amount (ω) of 1.25 wt%, reaction time (t) of 10 min. Moreover, a high desulfurization rate was obtained during oxidation of benzothiophene (BT) or 4,6-DMDBT (4,6-dimethyl-dibenzothiophene) under the aforementioned conditions. The oxidation reactivity of different S compounds was decreased in the order of DBT, 4,6-DMDBT and BT. The remarkable advantage of the novel ODS system is that the desulfurization condition applies in the presence of air at ambient conditions without peroxides, aqueous solvent or biphasic oil-aqueous solution system. (plasma technology)

  15. Oxidative desulfurization of benzothiophene and thiophene with WOx/ZrO2 catalysts: Effect of calcination temperature of catalysts

    International Nuclear Information System (INIS)

    Hasan, Zubair; Jeon, Jaewoo; Jhung, Sung Hwa

    2012-01-01

    Highlights: ► Oxidative desulfurization was studied with WO x /ZrO 2 calcined at different temp. ► The importance of the phases of zirconia and tungsten oxide was suggested. ► The catalyst was analyzed thoroughly with Raman and XRD techniques. ► The importance of electron density on S was confirmed with the kinetics of oxidation. - Abstract: Oxidative desulfurization (ODS) of model fuel containing benzothiophene (BT) or thiophene (Th) has been carried out with WO x /ZrO 2 catalyst, which was calcined at various temperatures. Based on the conversion of BT in the model fuel, it can be shown that the optimum calcination temperature of WO x /ZrO 2 catalyst is around 700 °C. The most active catalyst is composed of tetragonal zirconia (ZrO 2 ) with well dispersed polyoxotungstate species and it is necessary to minimize the contents of the crystalline WO 3 and monoclinic ZrO 2 for a high BT conversion. The oxidation rate was interpreted with the first-order kinetics, and it demonstrated the importance of electron density since the kinetic constant for BT was higher than that for Th even though the BT is larger than Th in size. A WO x /ZrO 2 catalyst, treated suitably, can be used as a reusable active catalyst in the ODS.

  16. Desulfurization of Diesel Fuel by Oxidation and Solvent Extraction

    Directory of Open Access Journals (Sweden)

    Wadood Taher Mohammed

    2015-02-01

    Full Text Available This research presents a study in ultra-desulfurization of diesel fuel produced from conventional hydro desulfurization process, using oxidation and solvent extraction techniques. Dibenzothiophene (DBT was the organosulfur compound that had been detected in sulfur removal. The oxidation process used hydrogen peroxide as an oxidant and acetic acid as homogeneous catalyst . The solvent extraction process used acetonitrile (ACN and N-methyl – 2 - pyrrolidone (NMP as extractants . Also the effect of five parameters (stirring speed :150 , 250 , 350 , and 450 rpm, temperature (30 , 40 , 45 , and 50 oC, oxidant/simulated diesel fuel ratio (0.5 , 0.75 , 1 , and 1.5 , catalyst/oxidant ratio(0.125,0.25,0.5,and0.75 , and solvent/simulated diesel fuel ratio(0.5,0.6,0.75,and1 were examined as well as solvent type. The results exhibit that the highest removal of sulfur is 98.5% using NMP solvent while it is 95.8% for ACN solvent. The set of conditions that show the highest sulfur removal is: stirring speed of 350 rpm , temperature 50oC , oxidant/simulated diesel fuel ratio 1 , catalyst/oxidant ratio 0.5 , solvent/simulated diesel fuel ratio 1. These best conditions were applied upon real diesel fuel (produced from Al-Dora refinerywith 1000 ppm sulfur content . It was found that sulfur removal was 64.4% using ACN solvent and 75% using NMP solvent.

  17. Desulfurization of oxidized diesel using ionic liquids

    Science.gov (United States)

    Wilfred, Cecilia D.; Salleh, M. Zulhaziman M.; Mutalib, M. I. Abdul

    2014-10-01

    The extraction of oxidized sulfur compounds from diesel were carried out using ten types of ionic liquids consisting of different cation and anion i.e. 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazoium thiocyanate, 1-butyl-3-methylimidazoium dicyanamide, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazoliumhexafluorophosphate, 1-hexyl-3-methylimidazolium trifluoromethanesulfonate, trioctylmethylammonium chloride, 1-propionitrile-3-butylimidazolium thiocyanate, 1-propionitrile-3-butylimidazolium dicyanamide and 1-butyl-6-methylquinolinium dicyanamide. The oxidation of diesel was successfully done using phosphotungstic acid as the catalyst, hydrogen peroxide (H2O2) as the oxidant and trioctylmethylammonium chloride as the phase transfer agent. The oxidation of diesel changes the sulfur compounds into sulfone which increases its polarity and enhances the ionic liquid's extraction performance. Result showed that ionic liquid [C4mquin][N(CN)2] performed the highest sulfur removal (91% at 1:5 diesel:IL ratio) compared to the others.

  18. Oxide Evolution in ODS Steel Resulting From Friction Stir Welding

    Science.gov (United States)

    2014-06-01

    the SZ on both the AS and RS of 304L stainless steel , from [16]. ...........................................12  Figure 7.  Past research conditions...being done on void swelling and embrittlement effects. Reduced activation ferritic/ martensitic (RAFM) steels and oxide dispersion strengthened (ODS...growth by grain boundary pinning at higher temperatures. Another type of ODS steel is 9-Cr martensitic steel , which is not considered in this research

  19. High temperature oxidation test of oxide dispersion strengthened (ODS) steel claddings

    International Nuclear Information System (INIS)

    Narita, Takeshi; Ukai, Shigeharu; Kaito, Takeji; Ohtsuka, Satoshi; Matsuda, Yasushi

    2006-07-01

    In a feasibility study of ODS steel cladding, its high temperature oxidation resistance was evaluated. Although addition of Cr is effective for preventing high temperature oxidation, excessively higher amount of Cr leads to embrittlement due to the Cr-rich α' precipitate formation. In the ODS steel developed by the Japan Atomic Energy Agency (JAEA), the Cr content is controlled in 9Cr-ODS martensite and 12Cr-ODS ferrite. In this study, high temperature oxidation test was conducted for ODS steels, and their results were compared with that of conventional austenitic stainless steel and ferritic-martensitic stainless steel. Following results were obtained in this study. (1) 9Cr-ODS martensitic and 12Cr-ODS ferritic steel have superior high temperature oxidation resistance compared to 11mass%Cr PNC-FMS and even 17mass% SUS430 and equivalent to austenitic PNC316. (2) The superior oxidation resistance of ODS steel was attributed to earlier formation of the protective alpha-Cr 2 O 3 layer at the matrix and inner oxide scale interface. The grain size of ODS steel is finer than that of PNC-FMS, so the superior oxidation resistance of ODS steel can be attributed to the enhanced Cr-supplying rate throughout the accelerated grain boundary diffusion. Finely dispersed Y 2 O 3 oxide particles in the ODS steel matrix may also stabilized the adherence between the protective alpha-Cr 2 O 3 layer and the matrix. (author)

  20. Zircaloy cladding ID/OD oxidation studies. Final report

    International Nuclear Information System (INIS)

    Westerman, R.E.; Hesson, G.M.

    1977-11-01

    The ID/OD oxide ratio that forms on Zircaloy tubing at temperatures relevant to postulated LOCA conditions was measured as a function of time, temperature, and distance from the rupture. The average ratio at the rupture position was less than unity, and decreased with decreasing test time and increasing distance from the point of rupture. The maximum observed ID/OD oxide ratio was 1.4. Ratios in excess of unity were typically found to be a consequence of the OD oxide being thinner than would have been anticipated from the nominal test conditions. Confirmatory data were also obtained on the isothermal oxidation kinetics of Zircaloy. These data are in good agreement with those obtained by other investigators and confirm the conservative nature of the Baker-Just equation that is required for use in licensing calculations

  1. Oxidative desulfurization of fuel oil by pyridinium-based ionic liquids.

    Science.gov (United States)

    Zhao, Dishun; Wang, Yanan; Duan, Erhong

    2009-10-28

    In this work, an N-butyl-pyridinium-based ionic liquid [BPy]BF(4) was prepared. The effect of extraction desulfurization on model oil with thiophene and dibenzothiophene (DBT) was investigated. Ionic liquids and hydrogen peroxide (30%) were tested in extraction-oxidation desulfurization of model oil. The results show that the ionic liquid [BPy]BF(4) has a better desulfurization effect. The best technological conditions are: V(IL)/V(Oil) /V(H(2)O(2)) = 1:1:0.4, temperature 55 degrees C, the time 30 min. The ratio of desulfurization to thiophene and DBT reached 78.5% and 84.3% respectively, which is much higher than extraction desulfurization with simple ionic liquids. Under these conditions, the effect of desulfurization on gasoline was also investigated. The used ionic liquids can be recycled up to four times after regeneration.

  2. Oxidative Desulfurization of Fuel Oil by Pyridinium-Based Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Erhong Duan

    2009-10-01

    Full Text Available In this work, an N-butyl-pyridinium-based ionic liquid [BPy]BF4 was prepared. The effect of extraction desulfurization on model oil with thiophene and dibenzothiophene (DBT was investigated. Ionic liquids and hydrogen peroxide (30% were tested in extraction-oxidation desulfurization of model oil. The results show that the ionic liquid [BPy]BF4 has a better desulfurization effect. The best technological conditions are: V(IL/V(Oil /V(H2O2 = 1:1:0.4, temperature 55 °C, the time 30 min. The ratio of desulfurization to thiophene and DBT reached 78.5% and 84.3% respectively, which is much higher than extraction desulfurization with simple ionic liquids. Under these conditions, the effect of desulfurization on gasoline was also investigated. The used ionic liquids can be recycled up to four times after regeneration.

  3. Intensification of oxidative desulfurization of gas oil by ultrasound irradiation: Optimization using Box–Behnken design (BBD)

    International Nuclear Information System (INIS)

    Jalali, Mohammad Reza; Sobati, Mohammad Amin

    2017-01-01

    Highlights: • Ultrasound-assisted oxidative desulfurization (UAOD) of gas oil was studied. • The influences of the different operating parameters were investigated. • Response surface methodology (RSM) was used to find the best operating parameters. • An accurate correlation was developed for the sulfur removal. • Ultrasound-assisted desulfurization process was compared with conventional process. - Abstract: In the present work, ultrasound assisted oxidative desulfurization (UAOD) of gas oil as the feedstock with sulfur content of 2210 ppmw was investigated using a mixture of hydrogen peroxide and formic acid as the oxidant and catalyst, respectively. The influences of main process variables such as sonication time (2–30 min), oxidation temperature (40–70 °C), hydrogen peroxide to sulfur molar ratio (10–50), formic acid to oxidant molar ratio (2–4), ultrasound power per gas oil volume (5.56–8.89 W/mL), and number of extraction stages (1–4) on the sulfur removal of gas oil were investigated. Response surface methodology (RSM) based on Box–Behnken design (BBD) and single-factor experiments were employed. The best performance of UAOD process for gas oil was achieved at 50 °C of reaction temperature, oxidant to sulfur molar ratio of 46.36, formic acid to oxidant molar ratio of 3.22, sonication time of 19.81 min, and 7.78 W/mL as the ultrasound power per gas oil volume. The sulfur removal of UAOD process was evaluated after oxidation under the abovementioned conditions followed by (a) one stage extraction and (b) four stages extraction using acetonitrile as solvent. The observed sulfur removal was 87 for case (a) and 96.2% for case (b). The UAOD process was also compared with conventional ODS process. Considerable improvement on the sulfur removal was observed specially in lower reaction time in the case of using ultrasound irradiation in comparison with conventional mixing.

  4. Casting technology for ODS steels - the internal oxidation approach

    Science.gov (United States)

    Miran, S.; Franke, P.; Möslang, A.; Seifert, H. J.

    2017-07-01

    The formation of stainless ODS steel by internal oxidation of as-cast steel has been investigated. An alloy (Fe-16Cr-0.2Al-0.05Y, wt.%) was embedded in a (VO/V2O3) powder mixture serving as an oxygen activity buffer and heat treated at 1450 °C for 20 h. After this procedure no oxide scale was present on the surface of the sample but a zone of internal oxidation with a depth of about 2000 μm was formed in its interior. The precipitates within this zone consisted of two types of oxides. Discrete aluminium oxide particles with a size of a few micrometres were formed in outer regions of the specimen. Finer aluminium-yttrium oxides with a size of some hundred nanometres were mainly precipitated in inner regions of the sample. The results can be considered as a promising step towards an alternative production route for ODS steels.

  5. Catalytic oxidative desulfurization of diesel utilizing hydrogen peroxide and functionalized-activated carbon in a biphasic diesel-acetonitrile system

    Energy Technology Data Exchange (ETDEWEB)

    Haw, Kok-Giap; Bakar, Wan Azelee Wan Abu; Ali, Rusmidah; Chong, Jiunn-Fat [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia); Kadir, Abdul Aziz Abdul [Department of Petroleum Engineering, Faculty of Chemical and Natural Resources Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia)

    2010-09-15

    This paper presents the development of granular functionalized-activated carbon as catalysts in the catalytic oxidative desulfurization (Cat-ODS) of commercial Malaysian diesel using hydrogen peroxide as oxidant. Granular functionalized-activated carbon was prepared from oil palm shell using phosphoric acid activation method and carbonized at 500 C and 700 C for 1 h. The activated carbons were characterized using various analytical techniques to study the chemistry underlying the preparation and calcination treatment. Nitrogen adsorption/desorption isotherms exhibited the characteristic of microporous structure with some contribution of mesopore property. The Fourier Transform Infrared Spectroscopy results showed that higher activation temperature leads to fewer surface functional groups due to thermal decomposition. Micrograph from Field Emission Scanning Electron Microscope showed that activation at 700 C creates orderly and well developed pores. Furthermore, X-ray Diffraction patterns revealed that pyrolysis has converted crystalline cellulose structure of oil palm shell to amorphous carbon structure. The influence of the reaction temperature, the oxidation duration, the solvent, and the oxidant/sulfur molar ratio were examined. The rates of the catalytic oxidative desulfurization reaction were found to increase with the temperature, and H{sub 2}O{sub 2}/S molar ratio. Under the best operating condition for the catalytic oxidative desulfurization: temperature 50 C, atmospheric pressure, 0.5 g activated carbon, 3 mol ratio of hydrogen peroxide to sulfur, 2 mol ratio of acetic acid to sulfur, 3 oxidation cycles with 1 h for each cycle using acetonitrile as extraction solvent, the sulfur content in diesel was reduced from 2189 ppm to 190 ppm with 91.3% of total sulfur removed. (author)

  6. Catalytic oxidative desulfurization of liquid hydrocarbon fuels using air

    Science.gov (United States)

    Sundararaman, Ramanathan

    Conventional approaches to oxidative desulfurization of liquid hydrocarbons involve use of high-purity, expensive water soluble peroxide for oxidation of sulfur compounds followed by post-treatment for removal of oxidized sulfones by extraction. Both are associated with higher cost due to handling, storage of oxidants and yield loss with extraction and water separation, making the whole process more expensive. This thesis explores an oxidative desulfurization process using air as an oxidant followed by catalytic decomposition of sulfones thereby eliminating the aforementioned issues. Oxidation of sulfur compounds was realized by a two step process in which peroxides were first generated in-situ by catalytic air oxidation, followed by catalytic oxidation of S compounds using the peroxides generated in-situ completing the two step approach. By this technique it was feasible to oxidize over 90% of sulfur compounds present in real jet (520 ppmw S) and diesel (41 ppmw S) fuels. Screening of bulk and supported CuO based catalysts for peroxide generation using model aromatic compound representing diesel fuel showed that bulk CuO catalyst was more effective in producing peroxides with high yield and selectivity. Testing of three real diesel fuels obtained from different sources for air oxidation over bulk CuO catalyst showed different level of effectiveness for generating peroxides in-situ which was consistent with air oxidation of representative model aromatic compounds. Peroxides generated in-situ was then used as an oxidant to oxidize sulfur compounds present in the fuel over MoO3/SiO2 catalyst. 81% selectivity of peroxides for oxidation of sulfur compounds was observed on MoO3/SiO2 catalyst at 40 °C and under similar conditions MoO3/Al2O3 gave only 41% selectivity. This difference in selectivity might be related to the difference in the nature of active sites of MoO3 on SiO2 and Al2O 3 supports as suggested by H2-TPR and XRD analyses. Testing of supported and bulk Mg

  7. Extractive oxidative desulfurization of model oil/crude oil using KSF montmorillonite-supported 12-tungstophosphoric acid

    Directory of Open Access Journals (Sweden)

    Ezzat Rafiee

    2016-10-01

    Full Text Available Abstract 12-Tungstophosphoric acid (PW supported on KSF montmorillonite, PW/KSF, was used as catalyst for deep oxidative desulfurization (ODS of mixed thiophenic compounds in model oil and crude oil under mild conditions using hydrogen peroxide (H2O2 as an oxidizing agent. A one-factor-at-a-time method was applied for optimizing the parameters such as temperature, reaction time, amount of catalyst, type of extractant and oxidant-to-sulfur compounds (S-compounds molar ratio. The corresponding products can be easily removed from the model oil by using ethanol as the best extractant. The results showed high catalytic activity of PW/KSF in the oxidative removal of dibenzothiophene (DBT and mixed thiophenic model oil under atmospheric pressure at 75 °C in a biphasic system. To investigate the oxidation and adsorption effects of crude oil composition on ODS, the effects of cyclohexene, 1,7-octadiene and o-xylene with different concentrations were studied.

  8. Oxidative Desulfurization of Fuel Oil by Pyridinium-Based Ionic Liquids

    OpenAIRE

    Erhong Duan; Dishun Zhao; Yanan Wang

    2009-01-01

    In this work, an N-butyl-pyridinium-based ionic liquid [BPy]BF4 was prepared. The effect of extraction desulfurization on model oil with thiophene and dibenzothiophene (DBT) was investigated. Ionic liquids and hydrogen peroxide (30%) were tested in extraction-oxidation desulfurization of model oil. The results show that the ionic liquid [BPy]BF4 has a better desulfurization effect. The best technological conditions are: V(IL)/V(Oil) /V(H2O2) = 1:1:0.4, temperature 55 °C, the time 30 min. The ...

  9. The effect of annealing and desulfurization on oxide spallation of turbine airfoil material

    International Nuclear Information System (INIS)

    Briant, C.L.; Murphy, W.H.; Schaeffer, J.C.

    1995-01-01

    In this paper the authors report a study that addresses the sulfur-induced spallation theory. Previous work has shown that a high temperature anneal in hydrogen desulfurizes nickel-base alloys and greatly improves their resistance to oxide spallation. The authors will show that such an anneal can be applied successfully to a Ni-base airfoil material. Both Auger segregation experiments and chemical analyses show that this anneal desulfurizes the material, at least in the absence of yttrium. However, the results suggest that factors other than desulfurization may be contributing to the improvement in spallation resistance produced by the anneal

  10. Fracture behavior of the ODS steels prepared by internal oxidation

    Czech Academy of Sciences Publication Activity Database

    Stratil, Luděk; Šiška, Filip; Hadraba, Hynek; Bártková, Denisa; Fintová, Stanislava; Puchý, V.

    2017-01-01

    Roč. 124, NOV (2017), s. 1108-1111 ISSN 0920-3796 R&D Projects: GA ČR GJ15-21292Y; GA ČR(CZ) GA14-25246S Institutional support: RVO:68081723 Keywords : ODS * Internal oxidation * Fracture toughness * J-R curve * Fracture analysis Subject RIV: JG - Metallurgy OBOR OECD: Materials engineering Impact factor: 1.319, year: 2016

  11. Speciation of Raney Copper Oxide during High-Temperature Desulfurization

    International Nuclear Information System (INIS)

    Wang, T. C.; Chen, C. Y.; Huang, H.-L.; Wang, H. Paul; Wei Yuling

    2007-01-01

    Speciation of copper in the Raney copper oxides (R-CuO) during high-temperature desulfurization has been studied by X-ray absorption spectroscopy. The preedge XANES spectra (8975-8979 eV) of R-CuO exhibit a very weak 1s-to-3d transition forbidden by the selection rule in the case of the perfect octahedral symmetry. A shoulder at 8985-8988 eV and an intense band at 8994-9002 eV can be attributed to the 1s-to-4p transition that indicates the existence of the Cu(II) species. The preedge band at 8981-8984 eV can be attributed to the dipole-allowed 1s-to-4p transition of Cu(I), suggesting an existence of Cu2S during sulfurization. An enhanced absorbance at 9003 eV shows that Cu(0) species may be formed in the sulfurized R-CuO. The main copper species in regenerated R-CuO are CuO (96%) and Cu2S (4%)

  12. Gas cleaning and hydrogen sulfide removal for COREX coal gas by sorption enhanced catalytic oxidation over recyclable activated carbon desulfurizer.

    Science.gov (United States)

    Sun, Tonghua; Shen, Yafei; Jia, Jinping

    2014-02-18

    This paper proposes a novel self-developed JTS-01 desulfurizer and JZC-80 alkaline adsorbent for H2S removal and gas cleaning of the COREX coal gas in small-scale and commercial desulfurizing devices. JTS-01 desulfurizer was loaded with metal oxide (i.e., ferric oxides) catalysts on the surface of activated carbons (AC), and the catalyst capacity was improved dramatically by means of ultrasonically assisted impregnation. Consequently, the sulfur saturation capacity and sulfur capacity breakthrough increased by 30.3% and 27.9%, respectively. The whole desulfurizing process combined selective adsorption with catalytic oxidation. Moreover, JZC-80 adsorbent can effectively remove impurities such as HCl, HF, HCN, and ash in the COREX coal gas, stabilizing the system pressure drop. The JTS-01 desulfurizer and JZC-80 adsorbent have been successfully applied for the COREX coal gas cleaning in the commercial plant at Baosteel, Shanghai. The sulfur capacity of JTS-01 desulfurizer can reach more than 50% in industrial applications. Compared with the conventional dry desulfurization process, the modified AC desulfurizers have more merit, especially in terms of the JTS-01 desulfurizer with higher sulfur capacity and low pressure drop. Thus, this sorption enhanced catalytic desulfurization has promising prospects for H2S removal and other gas cleaning.

  13. Ultrasound-assisted oxidative desulfurization of bunker-C oil using tert-butyl hydroperoxide.

    Science.gov (United States)

    Tang, Qiong; Lin, Song; Cheng, Ying; Liu, Sujun; Xiong, Jun-Ru

    2013-09-01

    This work investigated the ultrasonic assisted oxidative desulfurization of bunker-C oil with TBHP/MoO3 system. The operational parameters for the desulfurization procedure such as ultrasonic irradiation time, ultrasonic wave amplitude, catalyst initial concentration and oxidation agent initial concentration were studied. The experimental results show that the present oxidation system was very efficient for the desulfurization of bunker-C oil and ~35% sulfur was removed which was dependent on operational parameters. The application of ultrasonic irradiation allowed sulfur removal in a shorter time. The stronger the solvent polarity is, the higher the sulfur removal rate, but the recovery rate of oil is lower. The sulfur compounds in bunker-C oil reacted with TBHP to produce corresponding sulfoxide, and further oxidation produced the corresponding sulfone. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Oxidative desulfurization of benzothiophene and thiophene with WOx/ZrO2 catalysts: effect of calcination temperature of catalysts.

    Science.gov (United States)

    Hasan, Zubair; Jeon, Jaewoo; Jhung, Sung Hwa

    2012-02-29

    Oxidative desulfurization (ODS) of model fuel containing benzothiophene (BT) or thiophene (Th) has been carried out with WO(x)/ZrO2 catalyst, which was calcined at various temperatures. Based on the conversion of BT in the model fuel, it can be shown that the optimum calcination temperature of WOx/ZrO2 catalyst is around 700 °C. The most active catalyst is composed of tetragonal zirconia (ZrO2) with well dispersed polyoxotungstate species and it is necessary to minimize the contents of the crystalline WO3 and monoclinic ZrO2 for a high BT conversion. The oxidation rate was interpreted with the first-order kinetics, and it demonstrated the importance of electron density since the kinetic constant for BT was higher than that for Th even though the BT is larger than Th in size. A WOx/ZrO2 catalyst, treated suitably, can be used as a reusable active catalyst in the ODS. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Oxidative desulfurization of benzene fraction on transition metal oxides

    Science.gov (United States)

    Boikov, E. B.; Vishnetskaya, M. V.

    2013-02-01

    It is established that molecular oxygen is able to oxidize thiophene selectively in a mixture with benzene on V2O5 · MoO3. The introduction of thiophene inhibits the oxidation of benzene. It is shown that the conversion of thiophene during operation of the catalyst is reduced at first and then increases until it reaches its initial value.

  16. The desulfurization mechanism of iron-manganese compound oxide desulfurizer for removal of COS from coal gas

    Energy Technology Data Exchange (ETDEWEB)

    Wang Fang-fang; Zhao Hai; Zhang De-xiang; Gao Jin-sheng [East China University of Science and Technology. Shanghai (China). School of Resource and Environmental Engineering

    2008-02-15

    The sorbent, atmospheric and components of outlet gas were analyzed by mass spectra, XRD, SEM, EDS etc. Desulfurisation performance of sorbents is good at 240 - 400 {sup o}C, atmospheric pressure and space speed of 500 - 2,000 h {sup -1}. The possible mechanism of desulfurisation reactions was obtained by analyzing the reduction- adsorption-sulfidation process. Carbon oxysulfide (COS) was converted to H{sub 2}S by hydrogen in strongly reducing atmosphere firstly. Then H{sub 2}S was adsorbed on the surface of desulfurizers, reacted with active component and transformed metal sulfides and water. Efficiency of removal of carbonyl sulfur is better in an atmosphere without carbonaceous oxide than in one with it, under test conditions. The existence of carbonaceous oxide restrains hydrogenation and the hydrolytic process of COS, which leads to a higher concentration of COS in the outlet. It is shown that chemical conversion is the main pathway in the reaction system of COS. Hydrogenation is the main process in the removal of COS from syngas. COS is preferentially catalyzed with active components n desulfurization sorbents, and generates H{sub 2}S which is subsequently absorbed. 13 refs., 4 figs., 2 tabs.

  17. Enhancement of Oxidative Desulfurization Performance over UiO-66(Zr) by Titanium Ion Exchange.

    Science.gov (United States)

    Ye, Gan; Qi, Hui; Li, Xiaolin; Leng, Kunyue; Sun, Yinyong; Xu, Wei

    2017-07-19

    Oxidative desulfurization is considered to be one of the most promising methods for producing ultra-low-sulfur fuels because it can effectively remove refractory sulfur-containing aromatic compounds under mild conditions. In this work, the oxidative desulfurization performance over UiO-66(Zr) is greatly enhanced by Ti ion exchange. This strategy is not only efficient for UiO-66(Zr) with crystal defects but also for UiO-66(Zr) with high crystallinity. In particular, the performance of UiO-66(Zr) with high crystallinity in the oxidative desulfurization of dibenzothiophene can be improved more than 11-fold, which can be mainly attributed to the introduction of active Ti sites. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Highly flexible sub-1 nm tungsten oxide nanobelts as efficient desulfurization catalysts.

    Science.gov (United States)

    He, Jie; Liu, Huiling; Xu, Biao; Wang, Xun

    2015-03-01

    Ultrathin tungsten oxide nanobelts are successfully synthesized via a facile solvothermal method. Sub-1 nm thickness and hydrophobic surface property endow the nanobelts with flexibility, viscosity, gelation, and good catalytic performance in oxidative desulfurization. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. High Velocity Oxidation and Hot Corrosion Resistance of Some ODS Alloys

    Science.gov (United States)

    Lowell, C. E.; Deadmore, D. L.

    1977-01-01

    Several oxide dispersion strengthened (ODS) alloys were tested for cyclic, high velocity, oxidation, and hot corrosion resistance. These results were compared to the resistance of an advanced, NiCrAl coated superalloy. An ODS FeCrAl were identified as having sufficient oxidation and hot corrosion resistance to allow potential use in an aircraft gas turbine without coating.

  20. Multi-objective optimization of oxidative desulfurization in a sono-photochemical airlift reactor.

    Science.gov (United States)

    Behin, Jamshid; Farhadian, Negin

    2017-09-01

    Response surface methodology (RSM) was employed to optimize ultrasound/ultraviolet-assisted oxidative desulfurization in an airlift reactor. Ultrasonic waves were incorporated in a novel-geometry reactor to investigate the synergistic effects of sono-chemistry and enhanced gas-liquid mass transfer. Non-hydrotreated kerosene containing sulfur and aromatic compounds was chosen as a case study. Experimental runs were conducted based on a face-centered central composite design and analyzed using RSM. The effects of two categorical factors, i.e., ultrasound and ultraviolet irradiation and two numerical factors, i.e., superficial gas velocity and oxidation time were investigated on two responses, i.e., desulfurization and de-aromatization yields. Two-factor interaction (2FI) polynomial model was developed for the responses and the desirability function associate with overlay graphs was applied to find optimum conditions. The results showed enhancement in desulfurization ability corresponds to more reduction in aromatic content of kerosene in each combination. Based on desirability approach and certain criteria considered for desulfurization/de-aromatization, the optimal desulfurization and de-aromatization yields of 91.7% and 48% were obtained in US/UV/O 3 /H 2 O 2 combination, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Oxidative desulfurization of dibenzothiophene from model oil using ionic liquids as extracting agent

    Science.gov (United States)

    Taha, Mohd F.; Atikah, N.; Chong, F. K.; Shaharun, Maizatul S.

    2012-09-01

    The oxidative desulfurization of dibenzothiophene (DBT) from model oil (in n-dodecane) was carried out using ionic liquid as the extractant and catalyst, and hydrogen peroxide (H2O2) in combination with acetic acid (CH3COOH) and sulphuric acid (H2SO4) as the oxidant. The ionic liquids used were 1-butyl-3-methylimidazolium octyl sulphate ([Bmim][OcSO4]) and 1-butyl-3-methylimidazolium acetate ([Bmim][Ac]). The effect of the amounts of H2O2 on oxidative desulphurization of model oil was first investigated without the usage of ionic liquids at room temperature. The results indicate that greater amount of H2O2 give higher desulfurization and the maximum desulfurization in this study, i.e. 34 %, was occurred when the molar ratio of H2O2 to sulfur was 5:1. With the usage of ionic liquid and the molar ratio of 5:1 (H2O2:sulfur), the efficiency of DBT removal from model oil was increased significantly in terms of percent removal and removal time. Ionic liquid of [Bmim][OcSO4] performed better than [Bmim][Ac] with 72 % DBT removal. When molar ratio of H2O2 to sulphur was 5:1, volume ratio of ionic liquid to model oil was 1:1 and mixing time was 60 min at room temperature. The results indicate the potential of ionic liquids as the extractant and catalyst for oxidative desulfurization of hydrocarbon fuels.

  2. Polymeric carbon nitride nanomesh as an efficient and durable metal-free catalyst for oxidative desulfurization.

    Science.gov (United States)

    Shen, Lijuan; Lei, Ganchang; Fang, Yuanxing; Cao, Yanning; Wang, Xinchen; Jiang, Lilong

    2018-03-06

    We report the first use of polymeric carbon nitride (CN) for the catalytic selective oxidation of H 2 S. The as-prepared CN with unique ultrathin "nanomeshes" structure exhibits excellent H 2 S conversion and high S selectivity. In particular, the CN nanomesh also displays better durability in the desulfurization reaction than traditional catalysts, such as carbon- and iron-based materials.

  3. Desulfurization from thiophene by SO(4)(2-)/ZrO(2) catalytic oxidation at room temperature and atmospheric pressure.

    Science.gov (United States)

    Wang, Bo; Zhu, Jianpeng; Ma, Hongzhu

    2009-05-15

    Thiophene, due to its poison, together with its combustion products which causes air pollution and highly toxic characteristic itself, attracted more and more attention to remove from gasoline and some high concentration systems. As the purpose of achieving the novel method of de-thiophene assisted by SO(4)(2-)/ZrO(2) (SZ), three reactions about thiophene in different atmosphere at room temperature and atmospheric pressure were investigated. SO(4)(2-)/ZrO(2) catalyst were synthesized and characterized by X-ray photoelectron spectroscopy (XPS), Fourier transformation infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscope (SEM). The products were detected by gas chromatography-mass spectrometry (GC-MS). XP spectra show that ozone-catalyst system (SZO) have two forms of sulfur element (S(6+) and S(2-)) on the catalyst surface, which distinguished from that of air-catalyst system (SZA) and blank-catalyst system (SZB) (S(6+)). And the results of GC-MS exhibited that some new compounds has been produced under this extremely mild condition. Especially, many kinds of sulfur compounds containing oxygen, that is easier to be extracted by oxidative desulfurization (ODS), have been detected in the SZA-1.5h and SZB-3h system. In addition, some long chain hydrocarbons have also been detected. While in SZO-0.5h system, only long chain hydrocarbons were found. The results show that total efficiency of desulfurization from thiophene with ozone near to 100% can be obtained with the SO(4)(2-)/ZrO(2) catalytic oxidation reaction.

  4. Desulfurization from thiophene by SO42-/ZrO2 catalytic oxidation at room temperature and atmospheric pressure

    International Nuclear Information System (INIS)

    Wang Bo; Zhu Jianpeng; Ma Hongzhu

    2009-01-01

    Thiophene, due to its poison, together with its combustion products which causes air pollution and highly toxic characteristic itself, attracted more and more attention to remove from gasoline and some high concentration systems. As the purpose of achieving the novel method of de-thiophene assisted by SO 4 2- /ZrO 2 (SZ), three reactions about thiophene in different atmosphere at room temperature and atmospheric pressure were investigated. SO 4 2- /ZrO 2 catalyst were synthesized and characterized by X-ray photoelectron spectroscopy (XPS), Fourier transformation infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscope (SEM). The products were detected by gas chromatography-mass spectrometry (GC-MS). XP spectra show that ozone-catalyst system (SZO) have two forms of sulfur element (S 6+ and S 2- ) on the catalyst surface, which distinguished from that of air-catalyst system (SZA) and blank-catalyst system (SZB) (S 6+ ). And the results of GC-MS exhibited that some new compounds has been produced under this extremely mild condition. Especially, many kinds of sulfur compounds containing oxygen, that is easier to be extracted by oxidative desulfurization (ODS), have been detected in the SZA-1.5 h and SZB-3 h system. In addition, some long chain hydrocarbons have also been detected. While in SZO-0.5 h system, only long chain hydrocarbons were found. The results show that total efficiency of desulfurization from thiophene with ozone near to 100% can be obtained with the SO 4 2- /ZrO 2 catalytic oxidation reaction

  5. Deep desulfurization of diesel via peroxide oxidation using phosphotungstic acid as phase transfer catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Sachdeva, T.O.; Pant, K.K. [Department of Chemical Engineering, Indian Institute of Technology, Delhi, New Delhi, 110016 (India)

    2010-09-15

    High sulfur level in diesel fuel has been identified as a major contributor to air pollutant in term of sulfur dioxide (SO{sub x}) through diesel fueled vehicles. The main aim of the present work is to develop a promising methodology for ultra deep desulfurization of diesel fuel using oxidation followed by phase transfer of oxidized sulfur. Experiments were carried out in a batch reactor using n-decane as the model diesel compound and also using commercial diesel feedstock. To remove sulfur tetraoctylammonium bromide, phosphotungstic acid, and hydrogen peroxide were used as phase transfer agent, catalyst and oxidant respectively. The percent sulfur removal increases with increasing the initial concentration of sulfur in fuel and with increasing the reaction temperature. Similar trends were observed when commercial diesel was used to carry out desulfurization studies. The amphiphilic catalyst serves as a catalyst and also as an emulsifying agent to stabilize the emulsion droplets. The effects of temperature, agitation speed, quantity of catalyst and the phase transfer agent were studied to estimate the optimal conditions for the reactions. The sulfur removal from a commercial diesel by phase transfer catalysis has been found effective and removal efficiency was more than 98%. Kinetic experiments carried out for the desulfurization revealed that the sulfur removal results are best fitted to a pseudo first order kinetics and the apparent activation energy of desulfurization was 30.6 kJ/mol. (author)

  6. Deep desulfurization of diesel via peroxide oxidation using phosphotungstic acid as phase transfer catalyst

    International Nuclear Information System (INIS)

    Sachdeva, T.O.; Pant, K.K.

    2010-01-01

    High sulfur level in diesel fuel has been identified as a major contributor to air pollutant in term of sulfur dioxide (SO x ) through diesel fueled vehicles. The main aim of the present work is to develop a promising methodology for ultra deep desulfurization of diesel fuel using oxidation followed by phase transfer of oxidized sulfur. Experiments were carried out in a batch reactor using n-decane as the model diesel compound and also using commercial diesel feedstock. To remove sulfur tetraoctylammonium bromide, phosphotungstic acid, and hydrogen peroxide were used as phase transfer agent, catalyst and oxidant respectively. The percent sulfur removal increases with increasing the initial concentration of sulfur in fuel and with increasing the reaction temperature. Similar trends were observed when commercial diesel was used to carry out desulfurization studies. The amphiphilic catalyst serves as a catalyst and also as an emulsifying agent to stabilize the emulsion droplets. The effects of temperature, agitation speed, quantity of catalyst and the phase transfer agent were studied to estimate the optimal conditions for the reactions. The sulfur removal from a commercial diesel by phase transfer catalysis has been found effective and removal efficiency was more than 98%. Kinetic experiments carried out for the desulfurization revealed that the sulfur removal results are best fitted to a pseudo first order kinetics and the apparent activation energy of desulfurization was 30.6 kJ/mol. (author)

  7. Water corrosion test of oxide dispersion strengthened (ODS) steel claddings

    International Nuclear Information System (INIS)

    Narita, Takeshi; Ukai, Shigeharu; Kaito, Takeji; Ohtsuka, Satoshi; Matsuda, Yasushi

    2006-07-01

    As a part of feasibility study of ODS steel cladding, its water corrosion resistance was examined under water pool condition. Although addition of Cr is effective for preventing water corrosion, excessive Cr addition leads to embrittlement due to the Cr-rich α' precipitate formation. In the ODS steel developed by the Japan Atomic Energy Agency (JAEA), the Cr content is controlled in 9Cr-ODS martensite and 12Cr-ODS ferrite. In this study, water corrosion test was conducted for these ODS steels, and their results were compared with that of conventional austenitic stainless steel and ferritic-martensitic stainless steel. Following results were obtained in this study. (1) Corrosion rate of 9Cr-ODS martensitic and 12Cr-ODS ferritic steel are significantly small and no pitting was observed. Thus, these ODS steels have superior resistance for water corrosion under the condition of 60degC and pH8-12. (2) It was showed that 9Cr-ODS martensitic steel and 12Cr-ODS ferritic steel have comparable water corrosion resistance to that of PNC316 and PNC-FMS at 60degC for 1,000h under varying pH of 8, 10. Water corrosion resistance of these alloys is slightly larger than that of PNC316 and PNC-FMS at pH12 without significant difference of appearance and uneven condition. (author)

  8. Oxidative desulfurization of diesel with TBHP/isobutyl aldehyde/air oxidation system

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Wei; Wang, Chengyong; Lin, Peng; Lu, Xiaoping [Institute of Sonochemical Engineering, Nanjing University of Technology, Nanjing 210009, Jiangsu (China)

    2011-01-15

    Oxidative desulfurization of hydrogenation diesel (40 mL) was studied using air as oxidant, tert-butyl hydroperoxide (TBHP) as radical initiator at ambient pressure and moderate temperature in the presence of isobutyl aldehyde. TBHP could accelerate the production of carbonyl radical and its peroxidation. When the molar fraction of TBHP was 5 mmol, the conversion of DBT could reach 96.1% in the present of 20 mmol isobutyl aldehyde and air, which was more than that of 85.5% without initiator. The air was an effective oxidant and acetonitrile was an optimal solvent in this process. The sulfur content of the hydrogenation diesel could be reduced from 403 to 13 ppm (96.8% removed) under the synergistic effect of air, TBHP and isobutyl aldehyde. (author)

  9. Desulfurization of fuels with ionic liquids by extraction and oxidative extraction processes

    OpenAIRE

    Rodríguez Cabo, Borja

    2014-01-01

    The excessive emission of pollutants to the atmosphere has been a problem during the last few decades due to, among other reasons, the massive use of transports. In order to avoid this problem, many methods are being investigated as an alternative to the classical hydrodesulfurization technique, such as adsorption, biodesulfurization, extraction and oxidation. The extractive desulfurization is one of the most promising alternatives. Moreover, its enhancement with selective oxidation of sulfur...

  10. Synthesis and application of different phthalocyanine molecular sieve catalyst for oxidative desulfurization

    Science.gov (United States)

    Zhao, Na; Li, Siwen; Wang, Jinyi; Zhang, Ronglan; Gao, Ruimin; Zhao, Jianshe; Wang, Junlong

    2015-05-01

    M2(PcAN)2 (M=Fe, Co, Ni, Cu, Zn and Mn) anchored onto W-HZSM-5 (M2(PcAN)2-W-HZSM-5) or the M2(PcTN)2 doping W-HZSM-5 (M2(PcTN)2/W-HZSM-5) were prepared and their catalytic performances were tested for oxidative desulfurization in the presence of oxygen. Thiophene (T), benzothiophene (BT), and dibenzothiophene (DBT) were considered as sulfur compounds. Among zeolite-based catalysts, the Cu2(PcAN)2-W-HZSM-5 and Cu2(PcTN)2/W-HZSM-5 showed superior desulfurization performance and the activity of selectivity followed the order: T>BT>DBT. The effects of phthalocyanine concentration were studied by UV-Vis and calcination temperature was obtained by TG-DSC for Cu2(PcTN)2/W-HZSM-5. Catalysts were characterized by EA, IR, XRD, SEM, TEM, ICP, and N2 adsorption. Reaction time, temperature and the amount of catalyst were investigated as the important parameters for optimization of the reaction. Furthermore, a possible process of oxidative desulfurization and the reaction products were proposed. The reaction process of ultra-deep desulfurization.

  11. Oxidative desulfurization of benzothiophene and thiophene with WO{sub x}/ZrO{sub 2} catalysts: Effect of calcination temperature of catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Zubair; Jeon, Jaewoo [Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Jhung, Sung Hwa, E-mail: sung@knu.ac.kr [Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, Daegu 702-701 (Korea, Republic of)

    2012-02-29

    Highlights: Black-Right-Pointing-Pointer Oxidative desulfurization was studied with WO{sub x}/ZrO{sub 2} calcined at different temp. Black-Right-Pointing-Pointer The importance of the phases of zirconia and tungsten oxide was suggested. Black-Right-Pointing-Pointer The catalyst was analyzed thoroughly with Raman and XRD techniques. Black-Right-Pointing-Pointer The importance of electron density on S was confirmed with the kinetics of oxidation. - Abstract: Oxidative desulfurization (ODS) of model fuel containing benzothiophene (BT) or thiophene (Th) has been carried out with WO{sub x}/ZrO{sub 2} catalyst, which was calcined at various temperatures. Based on the conversion of BT in the model fuel, it can be shown that the optimum calcination temperature of WO{sub x}/ZrO{sub 2} catalyst is around 700 Degree-Sign C. The most active catalyst is composed of tetragonal zirconia (ZrO{sub 2}) with well dispersed polyoxotungstate species and it is necessary to minimize the contents of the crystalline WO{sub 3} and monoclinic ZrO{sub 2} for a high BT conversion. The oxidation rate was interpreted with the first-order kinetics, and it demonstrated the importance of electron density since the kinetic constant for BT was higher than that for Th even though the BT is larger than Th in size. A WO{sub x}/ZrO{sub 2} catalyst, treated suitably, can be used as a reusable active catalyst in the ODS.

  12. A recyclable ionic liquid-oxomolybdenum(vi) catalytic system for the oxidative desulfurization of model and real diesel fuel.

    Science.gov (United States)

    Julião, Diana; Gomes, Ana C; Pillinger, Martyn; Valença, Rita; Ribeiro, Jorge C; Gonçalves, Isabel S; Balula, Salete S

    2016-10-14

    The oxidative desulfurization of model and real diesel has been studied using the complex [MoO2Cl2(4,4'-di-tert-butyl-2,2'-bipyridine)] as (pre)catalyst, aq. H2O2 as oxidant, and an ionic liquid as extraction solvent. Under moderate conditions (50 °C) and short reaction times (desulfurization and ECODS steps, 76% sulfur removal was achieved for a real diesel (Sinitial = 2300 ppm). For both the model and real diesels, the catalyst/IL phase could be easily recycled and reused with no loss of desulfurization efficiency.

  13. Overview of welding of oxide dispersion strengthened (ODS) alloys for advanced nuclear reactor applications

    International Nuclear Information System (INIS)

    Kalvala, Prasad Rao; Raja, K.S.; Misra, Manoranjan; Tache, Ricard A.

    2009-01-01

    Oxide dispersion strengthened (ODS) alloys are very promising materials for Generation IV reactors with a potential to be used at elevated temperatures under severe neutron exposure environment. Welding of the ODS alloys is an understudied problem. In this paper, an overview of welding of the ODS alloys useful for advanced nuclear reactor applications is presented. The microstructural changes and the resultant mechanical properties obtained by various solid state welding processes are reviewed. Based on our results on PM2000, an approach for future work on welding of the ODS alloys is suggested. (author)

  14. Superoxide radical and UV irradiation in ultrasound assisted oxidative desulfurization (UAOD): A potential alternative for greener fuels

    Science.gov (United States)

    Chan, Ngo Yeung

    This study is aimed at improving the current ultrasound assisted oxidative desulfurization (UAOD) process by utilizing superoxide radical as oxidant. Research was also conducted to investigate the feasibility of ultraviolet (UV) irradiation-assisted desulfurization. These modifications can enhance the process with the following achievements: (1) Meet the upcoming sulfur standards on various fuels including diesel fuel oils and residual oils; (2) More efficient oxidant with significantly lower consumption in accordance with stoichiometry; (3) Energy saving by 90%; (4) Greater selectivity in petroleum composition. Currently, the UAOD process and subsequent modifications developed in University of Southern California by Professor Yen's research group have demonstrated high desulfurization efficiencies towards various fuels with the application of 30% wt. hydrogen peroxide as oxidant. The UAOD process has demonstrated more than 50% desulfurization of refractory organic sulfur compounds with the use of Venturella type catalysts. Application of quaternary ammonium fluoride as phase transfer catalyst has significantly improved the desulfurization efficiency to 95%. Recent modifications incorporating ionic liquids have shown that the modified UAOD process can produce ultra-low sulfur, or near-zero sulfur diesels under mild conditions with 70°C and atmospheric pressure. Nevertheless, the UAOD process is considered not to be particularly efficient with respect to oxidant and energy consumption. Batch studies have demonstrated that the UAOD process requires 100 fold more oxidant than the stoichiometic requirement to achieve high desulfurization yield. The expected high costs of purchasing, shipping and storage of the oxidant would reduce the practicability of the process. The excess use of oxidant is not economically desirable, and it also causes environmental and safety issues. Post treatments would be necessary to stabilize the unspent oxidant residual to prevent the waste

  15. Enrichment and cultivation of a sulfide-oxidizing bacteria consortium for its deploying in full-scale biogas desulfurization

    International Nuclear Information System (INIS)

    González Sánchez, Armando; Flores Márquez, Trinidad Eliseo; Revah, Sergio; Morgan Sagastume, Juan Manuel

    2014-01-01

    Operational experiences and strategies to get suitable chemolithoautotrophic sulfide-oxidizing biomass from activated sludge wastewater treatment plant for its deploying in a full-scale biogas desulfurization plant are described. An economic nutrient source was applied to foster microbial selection and rapid growth. Respirometry was implemented on full-scale installations to monitor the ability of the specialized bacteria consortium to oxidize reduced sulfur i.e. H 2 S. During the deployment in the full-scale desulfurization reactor, intermittent sulfide feed from biogas scrubbing was performed to accelerate the startup the desulfurization process. - Highlights: • A simple method for reaching high amounts of specialized sulfide-oxidizing bacterial consortium from activated sludge was developed. • The full-scale desulfurization process can be continuously monitored by respirometry allowing fast decision making if problems arise. • The dissolved sulfide concentration was estimated with an empirical correlation between measurements of ORP, dissolved oxygen and pH

  16. Growth mechanisms of oxide scales on ODS alloys in the temperature range 1000-1100deg C

    International Nuclear Information System (INIS)

    Quadakkers, W.J.

    1990-01-01

    After a short overview of the production, microstructure and mechanical properties of nickel- and iron-based oxide dispersion strengthened (ODS) alloys, the oxidation properties of this class of materials is extensively discussed. The excellent oxidation resistance of ODS alloys is illustrated by comparing their behaviour with conventional chromia and alumina forming wrought alloys of the same base composition. ODS alloys exhibit improved scale adherence, decreased oxide growth rates, enhanced selective oxidation and decreased oxide grain size compared to corresponding non-ODS alloys. It is shown, that these experimental observations can be explained by a change in oxide growth mechanism. The presence of the oxide dispersion reduces cation diffusion in the scale, causing the oxides on the ODS alloys to grow mainly by oxygen grain boundary transport. As oxide grain size increases with time, the oxide growth kinetics obey a sub-parabolic time dependence especially in the case of the alumina forming iron-based ODS alloy. (orig.) [de

  17. o-Iodoxybenzoic acid mediated oxidative desulfurization initiated domino reactions for synthesis of azoles.

    Science.gov (United States)

    Chaudhari, Pramod S; Pathare, Sagar P; Akamanchi, Krishnacharaya G

    2012-04-20

    A systematic exploration of thiophilic ability of o-iodoxybenzoic acid (IBX) for oxidative desulfurization to trigger domino reactions leading to new methodologies for synthesis of different azoles is described. A variety of highly substituted oxadiazoles, thiadiazoles, triazoles, and tetrazoles have been successfully synthesized in good to excellent yields, starting from readily accessible thiosemicarbazides, bis-diarylthiourea, 1,3-disubtituted thiourea, and thioamides. © 2012 American Chemical Society

  18. Low temperature oxidative desulfurization with hierarchically mesoporous titaniumsilicate Ti-SBA-2 single crystals.

    Science.gov (United States)

    Shi, Chengxiang; Wang, Wenxuan; Liu, Ni; Xu, Xueyan; Wang, Danhong; Zhang, Minghui; Sun, Pingchuan; Chen, Tiehong

    2015-07-21

    Hierarchically porous Ti-SBA-2 with high framework Ti content (up to 5 wt%) was firstly synthesized by employing organic mesomorphous complexes of a cationic surfactant (CTAB) and an anionic polyelectrolyte (PAA) as templates. The material exhibited excellent performance in oxidative desulfurization of diesel fuel at low temperature (40 °C or 25 °C) due to the unique hierarchically porous structure and high framework Ti content.

  19. Oxidative desulfurization of diesel fuel using amphiphilic quaternary ammonium phosphomolybdate catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Jianghua; Wang, Guanghui; Zeng, Danlin; Tang, Yan [College of Chemical Engineering and Technology, Wuhan University of Science and Technology, Wuhan 430081 (China); Wang, Meng; Li, Yanjun [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China)

    2009-12-15

    Phosphomolybdic acid (HPMo) modified respectively with tetramethyl ammonium chloride (TMAC), dodecyl trimethyl ammonium chloride (DTAC) and hexadecyl trimethyl ammonium chloride (HTAC) as the catalysts were prepared and characterized by FT-IR, XRD and SEM. The catalysts were evaluated for the oxidative desulfurization of benzothiophene (BT), dibenzothiophene (DBT) and straight-run diesel using hydrogen peroxide as an oxidant. Results show that all of the catalysts keep the Keggin structures and are finely dispersed with mixing of quaternary ammonium salts. Hexadecyl chains are more favorable to wrap up DBT to the catalytic center and form stable emulsion system with higher conversion rates of DBT. The shorter dodecyl chains can wrap up BT more suitably and bring smaller steric hindrance, which display higher conversion rates of BT. The oxidative reactions fit apparent first-order kinetics, and the apparent activation energies of DBT are much lower than those of BT. The desulfurization rate of straight-run diesel can be up to 84.4% with the recovery rate of 98.1% catalyzed by [HPMo][HTAC]{sub 2} in 2 h. When increasing the extraction times, the desulfurization rates increase, but the recovery rates of diesel decrease significantly. (author)

  20. Removal of Sulfur from CaF2 Containing Desulfurization Slag Exhausted from Secondary Steelmaking Process by Oxidation

    Science.gov (United States)

    Hiraki, Takehito; Kobayashi, Junichi; Urushibata, Satomi; Matsubae, Kazuyo; Nagasaka, Tetsuya

    2012-08-01

    The oxidation behavior of sulfur in desulfurization slag generated from the secondary steelmaking process with air has been investigated in the temperature range of 973 K to 1373 K (700 °C to 1100 °C). Although a high removal rate of sulfur is not achieved at temperatures lower than 1273 K (1000 °C) because of the formation of CaSO4, most of the sulfur is rapidly removed from slag as SO2 gas in the 1273 K to 1373 K (700 °C to 1100 °C) range. This finding indicates that the desulfurization slag generated from the secondary steelmaking process can be reused as a desulfurized flux through air oxidation, making it possible to reduce significantly the amount of desulfurization slag for disposal.

  1. A complementary and synergistic effect of Fe-Zn binary metal oxide in the process of high-temperature fuel gas desulfurization

    Institute of Scientific and Technical Information of China (English)

    翁斯灏; 吴幼青

    1996-01-01

    57Fe Mossbauer spectroscopy was used to investigate the evolution of Fe-Zn binary metal oxide sorbent in the process of high-temperature fuel gas desulfurization. The results of phase analyses show that Fe-Zn binary metal oxide sorbent is rapidly reduced in hot fuel gas and decomposed to new phases of highly dispersed microcrystalline elemental iron and zinc oxide, both of which become the active desulfurization constituents. A complementary and synergistic effect between active iron acting as a high sulfur capacity constituent and active zinc oxide acting as a deep refining desulfurization constituent exists in this type of sorbent for hot fuel gas desulfurization.

  2. Oxidation behavior of austenitic iron-base ODS alloy in supercritical water

    Energy Technology Data Exchange (ETDEWEB)

    Behnamian, Y.; Dong, Z.; Zahiri, R.; Kohandehghan, A.; Mitlin, D., E-mail: behnamia@ualberta.ca, E-mail: zdong@ualberta.ca, E-mail: kohandeh@ualberta.ca, E-mail: rzahiris@ualberta.ca, E-mail: dave.mitlin@ualberta.ca [Univ. of Alberta, Edmondon, AB (Canada); Zhou, Z., E-mail: zhouzhj@mater.ustb.edu.cn [Univ. of Science and Tech. Beijing, Beijing (China); Chen, W.; Luo, J., E-mail: weixing.chen@ualberta.ca, E-mail: Jingli.luo@ualberta.ca [Univ. of Alberta, Edmonton, AB (Canada); Zheng, W., E-mail: wenyue@nrcan.gc.ca [Natural Resources Canada, Canmet MATERIALS, Hamilton, ON (Canada); Guzonas, D. [Atomic Energy of Canada Limited, Chalk River, ON (Canada)

    2014-07-01

    In this study, the effect of exposure time on the corrosion of the 304 stainless steel based oxide dispersion strengthened alloy, SS304ODS, in supercritical water was investigated at 650 {sup o}C with constant dissolved oxygen concentration. The results show that the oxidation of SS304ODS in supercritical water followed a parabolic law at 650 {sup o}C. Discontinuous oxide scale with two distinct layers has formed after 550 hours. The inner layer was chromium-rich while the outer layer was iron-rich (Magnetite). The oxide islands grow with increasing the exposure time. With increasing exposure time, the quantity of oxide islands increased in which major preferential growth along oxide-substrate interface was observed. The possible mechanism of SS304ODS oxidation in supercritical water was also discussed. (author)

  3. Synthesis and characterization of porous metal oxides and desulfurization studies of sulfur containing compounds

    Science.gov (United States)

    Garces Trujillo, Hector Fabian

    This thesis contains two parts: 1) synthesis and characterization of porous metal oxides that include zinc oxide and a porous mixed-valent manganese oxide with an amorphous structure (AMO) 2) the desulfurization studies for the removal of sulfur compounds. Zinc oxide with different nano-scale morphologies may result in various porosities with different adsorption capabilities. A tunable shape microwave synthesis of ZnO nano-spheres in a co-solvent mixture is presented. The ZnO nano-sphere material is investigated as a desulfurizing sorbent in a fixed bed reactor in the temperature range 200 to 400 °C and compared with ZnO nanorods and platelet-like morphologies. Fresh and sulfided materials were characterized by X-ray diffraction (XRD), BET specific surface area, pore volume, scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (SEM/EDX), Raman spectroscopy, and thermogravimetric analysis (TGA). The tunable shape microwave synthesis of ZnO presents a high sulfur sorption capacity at temperatures as low as 200 °C which accounts for a three and four fold enhancement over the other preparations presented in this work, and reached 76 % of the theoretical sulfur capacity (TSC) at 300 °C. Another ZnO material with a bimodal micro- and mesopore size distribution investigated as a desulfurizing sorbent presents a sorption capacity that reaches 87% of the theoretical value for desulfurization at 400 °C at breakthrough time. A deactivation model that considers the activity of the solid reactant was used to fit the experimental data. Good agreement between the experimental breakthrough curves and the model predictions are obtained. Manganese oxides are a type of metal oxide materials commonly used in catalytic applications. Little is known about the adsorption capabilities for the removal of sulfur compounds. One of these manganese oxides; amorphous manganese oxide (AMO) is highly promising material for low temperature sorption processes. Amorphous

  4. Structure of Oxide Nanoparticles in Fe-16Cr MA/ODS Ferritic Steel

    Energy Technology Data Exchange (ETDEWEB)

    Hsiung, L; Fluss, M; Kimura, A

    2010-04-06

    Oxide nanoparticles in Fe-16Cr ODS ferritic steel fabricated by mechanical alloying (MA) method have been examined using high-resolution transmission electron microscopy (HRTEM) techniques. A partial crystallization of oxide nanoparticles was frequently observed in as-fabricated ODS steel. The crystal structure of crystalline oxide particles is identified to be mainly Y{sub 4}Al{sub 2}O{sub 9} (YAM) with a monoclinic structure. Large nanoparticles with a diameter larger than 20 nm tend to be incoherent and have a nearly spherical shape, whereas small nanoparticles with a diameter smaller than 10 nm tend to be coherent or semi-coherent and have faceted boundaries. The oxide nanoparticles become fully crystallized after prolonged annealing at 900 C. These results lead us to propose a three-stage formation mechanism of oxide nanoparticles in MA/ODS steels.

  5. Oxidative desulfurization of dibenzothiophene with molecular oxygen using emulsion catalysis.

    Science.gov (United States)

    Lü, Hongying; Gao, Jinbo; Jiang, Zongxuan; Yang, Yongxing; Song, Bo; Li, Can

    2007-01-14

    Dibenzothiophene (DBT) is oxidized to the corresponding sulfoxide and sulfone in an emulsion system (W/O) composed of polyoxometalate anion [C(18)H(37)N(CH(3))3](5)[PV(2)Mo(10)O(40)] as both the surfactant and catalyst, using molecular oxygen as the oxidant and aldehyde as the sacrificial agent under mild conditions.

  6. Deep desulfurization of diesel oil oxidized by Fe (VI) systems

    Energy Technology Data Exchange (ETDEWEB)

    Shuzhi Liu; Baohui Wang; Baochen Cui; Lanlan Sun [Daqing Petroleum Institute, Daqing (China). College of Chemistry and Chemical Engineering

    2008-03-15

    Fe (VI) compound, such as K{sub 2}FeO{sub 4}, is a powerful oxidizing agent. Its oxidative potential is higher than KMnO{sub 4}, O{sub 3} and Cl{sub 2}. Oxidation activity of Fe (VI) compounds can be adjusted by modifying their structure and pH value of media. The reduction of Fe (VI), differing from Cr and Mn, results in a relatively non-toxic by-product Fe (III) compounds, which suggests that Fe (VI) compound is an environmentally friendly oxidant. Oxidation of model sulfur compound and diesel oil by K{sub 2}FeO{sub 4} in water-phase, in organic acid and in the presence of phase-transfer catalysts is investigated, respectively. The results show that the activity of oxidation of benzothiophene (BT) and dibenzothiophene (DBT) is low in water-phase, even adding phase-transfer catalyst to the system, because K{sub 2}FeO{sub 4} reacts rapidly with water to form brown Fe(OH){sub 3} to lose ability of oxidation of organic sulfur compounds. The activity of oxidation of the BT and DBT increases markedly in acetic acid. Moreover, the addition of the solid catalyst to the acetic acid medium promotes very remarkably oxidation of organic sulfur compounds. Conversions of the DBT and BT are 98.4% and 70.1%, respectively, under the condition of room temperature, atmospheric pressure, acetic acid/oil (v/v) = 1.0, K{sub 2}FeO{sub 4}/S (mol/mol) = 1.0 and catalyst/K{sub 2}FeO{sub 4} (mol/mol) = 1.0. Under the same condition, diesel oil is oxidized, followed by furfural extraction, the results display sulfur removal rate is 96.7% and sulfur content in diesel oil reduces from 457 ppm to 15.1 ppm. 11 refs., 9 figs., 5 tabs.

  7. Radiation Stability of Nanoclusters in Nano-structured Oxide Dispersion Strengthened (ODS) Steels

    International Nuclear Information System (INIS)

    Certain, Alicia G.; Kuchibhatla, Satyanarayana; Shutthanandan, V.; Allen, T. R.

    2013-01-01

    Nanostructured oxide dispersion strengthened (ODS) steels are considered candidates for nuclear fission and fusion applications at high temperature and dose. The complex oxide nanoclusters in these alloys provide high-temperature strength and are expected to afford better radiation resistance. Proton, heavy ion, and neutron irradiations have been performed to evaluate cluster stability in 14YWT and 9CrODS steel under a range of irradiation conditions. Energy-filtered transmission electron microscopy and atom probe tomography were used in this work to analyze the evolution of the oxide population.

  8. Evaluation of oxide dispersion strengthened (ODS) molybdenum and molybdenum-rhenium alloys

    International Nuclear Information System (INIS)

    Mueller, A.J.; Bianco, R.; Buckman, R.W. Jr.

    1999-01-01

    Oxide dispersion strengthened (ODS) molybdenum alloys being developed for high temperature applications possess excellent high temperature strength and creep resistance. In addition they exhibit a ductile-to-brittle transition temperature (DBIT) in the worked and stress-relieved condition under longitudinal tensile load well below room temperature. However, in the recrystallized condition, the DBTT maybe near or above room temperature, depending on the volume fraction of oxide dispersion and the amount of prior work. Dilute rhenium additions (7 and 14 wt.%) to ODS molybdenum were evaluated to determine their effect on low temperature ductility. The addition of 7 wt.% rhenium to the ODS molybdenum did not significantly enhance the mechanical properties. However, the addition of 14 wt.% rhenium to the ODS molybdenum resulted in a DBTT well below room temperature in both the stress-relieved and recrystallized condition. Additionally, the tensile strength of ODS Mo-14Re is greater than the base ODS molybdenum at 1,000 to 1,250 C

  9. Durable zinc oxide-containing sorbents for coal gas desulfurization

    Science.gov (United States)

    Siriwardane, Ranjani V.

    1996-01-01

    Durable zinc-oxide containing sorbent pellets for removing hydrogen sulfide from a gas stream at an elevated temperature are made up to contain titania as a diluent, high-surface-area silica gel, and a binder. These materials are mixed, moistened, and formed into pellets, which are then dried and calcined. The resulting pellets undergo repeated cycles of sulfidation and regeneration without loss of reactivity and without mechanical degradation. Regeneration of the pellets is carried out by contacting the bed with an oxidizing gas mixture.

  10. Mixing-assisted oxidative desulfurization of model sulfur compounds using polyoxometalate/H2O2 catalytic system

    OpenAIRE

    Angelo Earvin Sy Choi; Susan Roces; Nathaniel Dugos; Meng-Wei Wan

    2016-01-01

    Desulfurization of fossil fuel derived oil is needed in order to comply with environmental regulations. Dibenzothiophene and benzothiophene are among the predominant sulfur compound present in raw diesel oil. In this study, mixing-assisted oxidative desulfurization of dibenzothiophene and benzothiophene were carried out using polyoxometalate/H2O2 systems and a phase transfer agent. The effects of reaction time (2–30 min) and temperature (30–70 °C) were examined in the oxidation of model sulfu...

  11. Ultrasound-assisted oxidative desulfurization and denitrogenation of liquid hydrocarbon fuels: A critical review.

    Science.gov (United States)

    Ja'fari, Mahsa; Ebrahimi, Seyedeh Leila; Khosravi-Nikou, Mohammad Reza

    2018-01-01

    Nowadays, a continuously worldwide concern for development of process to produce ultra-low sulfur and nitrogen fuels have been emerged. Typical hydrodesulfurization and hydrodenitrogenation technology deals with important difficulties such as high pressure and temperature operating condition, failure to treat some recalcitrant compounds and limitations to meet the stringent environmental regulations. In contrary an advanced oxidation process that is ultrasound assisted oxidative desulfurization and denitrogenation satisfies latest environmental regulations in much milder conditions with more efficiency. The present work deals with a comprehensive review on findings and development in the ultrasound assisted oxidative desulfurization and denitrogenation (UAOD) during the last decades. The role of individual parameters namely temperature, residence time, ultrasound power and frequency, pH, initial concentration and types of sulfur and nitrogen compounds on the efficiency are described. What's more another treatment properties that is role of phase transfer agent (PTA) and solvents of extraction step, reaction kinetics, mechanism of the ultrasound, fuel properties and recovery in UAOD are reviewed. Finally, the required future works to mature this technology are suggested. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Ultrasound-assisted oxidative desulfurization of liquid fuels and its industrial application.

    Science.gov (United States)

    Wu, Zhilin; Ondruschka, Bernd

    2010-08-01

    Latest environmental regulations require a very deep desulfurization to meet the ultra-low sulfur diesel (ULSD, 15 ppm sulfur) specifications. Due to the disadvantages of hydrotreating technology on the slashing production conditions, costs and safety as well as environmental protection, the ultrasound-assisted oxidative desulfurization (UAOD) as an alternative technology has been developed. UAOD process selectively oxidizes sulfur in common thiophenes in diesel to sulfoxides and sulfones which can be removed via selective adsorption or extractant. SulphCo has successfully used a 5000 barrel/day mobile "Sonocracking" unit to duplicate on a commercial scale its proprietary process that applies ultrasonics at relatively low temperatures and pressures. The UAOD technology estimate capital costs less than half the cost of a new high-pressure hydrotreater. The physical and chemical mechanisms of UAOD process are illustrated, and the effective factors, such as ultrasonic frequency and power, oxidants, catalysts, phase-transfer agent, extractant and adsorbent, on reaction kinetics and product recovery are discussed in this review. Copyright 2009 Elsevier B.V. All rights reserved.

  13. Oxidative desulfurization of Cayirhan lignites by permanganate solution

    Energy Technology Data Exchange (ETDEWEB)

    Guru, M.; Tuzun, F.N.; Murathan, A.S.; Asan, A.; Kiyak, T. [Gazi University, Ankara (Turkey). Dept. for Chemical Engineering

    2008-07-01

    Unless important developments record new and renewable energy sources, the role of fossil fuels as an energy resource goes on. It is possible to detect sulfur, heavy metals, and tracer elements such as arsenic and selenium by decreasing calorific value of coals. Sulfur oxides, which are the main pollutants in atmosphere, are irritative to humans and plants, and erosion occurs on buildings. Although there are high lignite reservoirs, high sulfur content limits the efficient use of them. In this research, it is aimed to convert combustible sulfur in coal to non-combustible sulfur form in the ash by oxidizing it with permanganate solution. During this research, the effect of two different parameters of potassium permanganate concentration, processing time, and mean particle size were investigated at constant room temperature and shaking rate. The conversion of combustible sulfur to non-combustible sulfur form was achieved optimally with 0.14 M potassium permanganate solution, 0.1 mm mean particle size at 16 h of treatment time, and the combustible sulfur amount was decreased by 46.37% compared to undoped conditions.

  14. Development of Oxide Dispersion Strengthened (ODS) Ferritic Steel Through Powder Forging

    Science.gov (United States)

    Kumar, Deepak; Prakash, Ujjwal; Dabhade, Vikram V.; Laha, K.; Sakthivel, T.

    2017-04-01

    Oxide dispersion strengthened (ODS) ferritic steels are candidates for cladding tubes in fast breeder nuclear reactors. In this study, an 18%Cr ODS ferritic steel was prepared through powder forging route. Elemental powders with a nominal composition of Fe-18Cr-2 W-0.2Ti (composition in wt.%) with 0 and 0.35% yttria were prepared by mechanical alloying in a Simoloyer attritor under argon atmosphere. The alloyed powders were heated in a mild steel can to 1473 K under flowing hydrogen atmosphere. The can was then hot forged. Steps of sealing, degassing and evacuation are eliminated by using powder forging. Heating ODS powder in hydrogen atmosphere ensures good bonding between alloy powders. A dense ODS alloy with an attractive combination of strength and ductility was obtained after re-forging. On testing at 973 K, a loss in ductility was observed in yttria-containing alloy. The strength and ductility increased with increase in strain rate at 973 K. Reasons for this are discussed. The ODS alloy exhibited a recrystallized microstructure which is difficult to achieve by extrusion. No prior particle boundaries were observed after forging. The forged compacts exhibited isotropic mechanical properties. It is suggested that powder forging may offer several advantages over the traditional extrusion/HIP routes for fabrication of ODS alloys.

  15. Oxidative desulfurization of fuels catalyzed by Fenton-like ionic liquids at room temperature.

    Science.gov (United States)

    Jiang, Yunqing; Zhu, Wenshuai; Li, Huaming; Yin, Sheng; Liu, Hua; Xie, Qingjie

    2011-03-21

    Oxidation of the sulfur-containing compounds benzothiophene (BT), dibenzothiophene (DBT), and 4,6-dimethyldibenzothiophene (4,6-DMDBT) has been studied in a desulfurization system composed of model oil, hydrogen peroxide, and different types of ionic liquids [(C(8)H(17))(3)CH(3)N]Cl/FeCl(3), [(C(8)H(17))(3)CH(3)N]Cl/CuCl(2), [(C(8)H(17))(3)CH(3)N]Cl/ZnCl(2), [(C(8)H(17))(3)CH(3)N]Cl/SnCl(2), [(C(4)H(9))(3)CH(3)N]Cl/FeCl(3), [C(10)H(21)(CH(3))(3)N]Cl/FeCl(3), [(C(10)H(21))(2)(CH(3))(2)N]Cl/FeCl(3). Deep desulfurization is achieved in the Fenton-like ionic liquid [(C(8)H(17))(3)CH(3)N]Cl/FeCl(3) at 25 °C for 1 h. The desulfurization of DBT reaches 97.9%, in consuming very low amount of [(C(8)H(17))(3)CH(3)N]Cl/FeCl(3) (only 0.702 mmol). The reaction conditions, for example, the amount of [(C(8)H(17))(3)CH(3)N]Cl/FeCl(3) or H(2)O(2), the temperature, and the molar ratio of FeCl(3) to [(C(8)H(17))(3)CH(3)N]Cl, are investigated for this system. The oxidation reactivity of the different sulfur-containing compounds is found to decrease in the order of DBT>BT>4,6-DMDBT. The desulfurization system can be recycled six times without significant decrease in activity. The sulfur level of FCC gasoline could be reduced from 360 ppm to 110 ppm. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Photocatalytic oxidative desulfurization of dibenzothiophene catalyzed by amorphous TiO2 in ionic liquid

    International Nuclear Information System (INIS)

    Zhu, Wenshuai; Xu, Yehai; Li, Huaming; Dai, Bilian; Xu, Hui; Wang, Chao; Chao, Yanhong; Liu, Hui

    2014-01-01

    Three types of TiO 2 were synthesized by a hydrolysis and calcination method. The catalysts were characterized by X-ray powder diffraction (XRD), diffuse reflectance spectrum (DRS), Raman spectra, and X-ray photoelectron spectroscopy (XPS). The XRD and Raman spectra indicated that amorphous TiO 2 was successfully obtained at 100 .deg. C. The results indicated that amorphous TiO 2 achieved the highest efficiency of desulfurization. The photocatalytic oxidation of dibenzothiophene (DBT), benzothiophene (BT), 4,6-dimethyldibenzothiophene (4,6-DMDBT) and dodecanethiol (RSH) in model oil was studied at room temperature (30 .deg. C) with three catalysts. The system contained amorphous TiO 2 , H 2 O 2 , and [Bmim]BF 4 ionic liquid, ultraviolet (UV), which played vitally important roles in the photocatalytic oxidative desulfurization. Especially, the molar ratio of H 2 O 2 and sulfur (O/S) was only 2 : 1, which corresponded to the stoichiometric reaction. The sulfur removal of DBT-containing model oil with amorphous TiO 2 could reach 96.6%, which was apparently superior to a system with anatase TiO 2 (23.6%) or with anatase - rutile TiO 2 (18.2%). The system could be recycled seven times without a signicant decrease in photocatalytic activity

  17. Oxidative desulfurization of model diesel via dual activation by a protic ionic liquid.

    Science.gov (United States)

    Lü, Hongying; Wang, Shunan; Deng, Changliang; Ren, Wanzhong; Guo, Baocun

    2014-08-30

    A novel and green carboxylate-anion-based protic ionic liquid (PIL), [Hnmp]HCOO, was prepared through a simple and atom economic neutralization reaction between N-methyl-2-pyrrolidonium (NMP) and formic acids. Both FT-IR spectra and (1)H NMR confirmed its simple salt structure. [Hnmp]HCOO exhibited so high catalytic activity that the dibenzothiophene (DBT) removal reached 99% at 50°C in 3h under conditions of VPIL/Vmodel oil=1:10 and H2O2/DBT (O/S, molar ratio)=5. The catalytic oxidation reactivity of S-compounds was found to be in the order of DBT>4,6-dimethyldibenzothiophene (4,6-DMDBT)>benzothiophene (BT). The investigation on mechanism showed that oxidative desulfurization was realized through dual activation of PIL. Moreover, [Hnmp]HCOO can be recycled for five times with an unnoticeable decrease in desulfurization activity. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Photocatalytic oxidative desulfurization of dibenzothiophene catalyzed by amorphous TiO{sub 2} in ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Wenshuai; Xu, Yehai; Li, Huaming; Dai, Bilian; Xu, Hui; Wang, Chao; Chao, Yanhong; Liu, Hui [Jiangsu University, Zhenjiang (China)

    2014-02-15

    Three types of TiO{sub 2} were synthesized by a hydrolysis and calcination method. The catalysts were characterized by X-ray powder diffraction (XRD), diffuse reflectance spectrum (DRS), Raman spectra, and X-ray photoelectron spectroscopy (XPS). The XRD and Raman spectra indicated that amorphous TiO{sub 2} was successfully obtained at 100 .deg. C. The results indicated that amorphous TiO{sub 2} achieved the highest efficiency of desulfurization. The photocatalytic oxidation of dibenzothiophene (DBT), benzothiophene (BT), 4,6-dimethyldibenzothiophene (4,6-DMDBT) and dodecanethiol (RSH) in model oil was studied at room temperature (30 .deg. C) with three catalysts. The system contained amorphous TiO{sub 2}, H{sub 2}O{sub 2}, and [Bmim]BF{sub 4} ionic liquid, ultraviolet (UV), which played vitally important roles in the photocatalytic oxidative desulfurization. Especially, the molar ratio of H{sub 2}O{sub 2} and sulfur (O/S) was only 2 : 1, which corresponded to the stoichiometric reaction. The sulfur removal of DBT-containing model oil with amorphous TiO{sub 2} could reach 96.6%, which was apparently superior to a system with anatase TiO{sub 2} (23.6%) or with anatase - rutile TiO{sub 2} (18.2%). The system could be recycled seven times without a signicant decrease in photocatalytic activity.

  19. Investigations in physical mechanism of the oxidative desulfurization process assisted simultaneously by phase transfer agent and ultrasound.

    Science.gov (United States)

    Bhasarkar, Jaykumar B; Chakma, Sankar; Moholkar, Vijayanand S

    2015-05-01

    This paper attempts to discern the physical mechanism of the oxidative desulfurization process simultaneously assisted by ultrasound and phase transfer agent (PTA). With different experimental protocols, an attempt is made to deduce individual beneficial effects of PTA and ultrasound on the oxidative desulfurization system, and also the synergy between the effects of PTA and ultrasound. Effect of PTA is more marked for mechanically stirred system due to mass transfer limitations, while intense emulsification due to ultrasound helps overcome the mass transfer limitations and reduces the extent of enhancement of oxidation by PTA. Despite application of PTA and ultrasound, the intrinsic factors and properties of the reactants such as polarity (and hence partition coefficient) and diffusivity have a crucial effect on the extent of oxidation. The intrinsic reactivity of the oxidant also plays a vital role, as seen from the extent of oxidation achieved with performic acid and peracetic acid. The interfacial transport of oxidant in the form of oxidant-PTA complex reduces the undesired consumption of oxidant by the reducing species formed during transient cavitation in organic medium, which helps effective utilization of oxidant towards desulfurization. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. A green surfactant-assisted synthesis of hierarchical TS-1 zeolites with excellent catalytic properties for oxidative desulfurization.

    Science.gov (United States)

    Du, Shuting; Li, Fen; Sun, Qiming; Wang, Ning; Jia, Mingjun; Yu, Jihong

    2016-02-25

    Hierarchical TS-1 zeolites with uniform intracrystalline mesopores have been successfully synthesized through the hydrothermal method by using the green and cheap surfactant Triton X-100 as the mesoporous template. The resultant materials exhibit remarkably enhanced catalytic activity in oxidative desulfurization reactions compared to the conventional TS-1 zeolite.

  1. A template-free solvent-mediated synthesis of high surface area boron nitride nanosheets for aerobic oxidative desulfurization.

    Science.gov (United States)

    Wu, Peiwen; Zhu, Wenshuai; Chao, Yanhong; Zhang, Jinshui; Zhang, Pengfei; Zhu, Huiyuan; Li, Changfeng; Chen, Zhigang; Li, Huaming; Dai, Sheng

    2016-01-04

    Hexagonal boron nitride nanosheets (h-BNNs) with rather high specific surface area (SSA) are important two-dimensional layer-structured materials. Here, a solvent-mediated synthesis of h-BNNs revealed a template-free lattice plane control strategy that induced high SSA nanoporous structured h-BNNs with outstanding aerobic oxidative desulfurization performance.

  2. Evolution of oxide nanoparticles during dynamic plastic deformation of ODS steel

    DEFF Research Database (Denmark)

    Zhang, Zhenbo; Mishin, Oleg; Tao, Nairong

    2014-01-01

    The microstructure as well as the deformation behavior of oxide nanoparticles has been analyzed in the ferritic ODS steel PM2000 after compression by dynamic plastic deformation (DPD) to different strains. A dislocation cell structure forms after deformation to a strain of 1.0. DPD to a strain of 2...

  3. Extractive de-sulfurization and de-ashing of high sulfur coals by oxidation with ionic liquids

    International Nuclear Information System (INIS)

    Saikia, Binoy K.; Khound, Kakoli; Baruah, Bimala P.

    2014-01-01

    Highlights: • Extractive de-sulfurization and de-ashing process for cleaning high sulfur coals. • The process removes inorganic as well as organic sulfur components from high sulfur coals. • The process has less risk to chemists and other surroundings. - Abstract: The environmental consequences of energy production from coals are well known, and are driving the development of desulfurization technologies. In this investigation, ionic liquids were examined for extractive desulfurization and de-ashing in industrially important high sulfur sub-bituminous Indian coals. The ionic liquids, namely, 1-n-butyl-3-methylimidazolium tetrafluoroborate (IL1) and 1-n-butyl 3-methylimidazolium chloride (IL2) were employed for desulfurization of a few Indian coal samples in presence of HCOOH/H 2 O 2 and V 2 O 5 . Results show the maximum removal of 50.20% of the total sulfur, 48.00% of the organic sulfur, and 70.37 wt% of the ash in this process. The ionic liquids were recovered and subsequently used for further desulfurization. FT-IR spectra reveal the transformation of organic sulfur functionalities into the sulfoxides (S=O) and sulfones (-SO 2 ) due to the oxidative reactions. The sulfate, pyrite and sulfides (aryls) signals in the near edge X-ray absorption fine structure (NEXAFS) of the oxidized coal samples showed sulfur transformation during the desulfurization process. The study demonstrates the removal of significant amount of inorganic as well as organic sulfur (aryls) components from the original high sulfur coal samples to make them cleaner

  4. Development of ODS (oxide dispersion strengthened) ferritic-martensitic steels for fast reactor fuel cladding

    International Nuclear Information System (INIS)

    Ukai, Shigeharu

    2000-01-01

    In order to attain higher burnup and higher coolant outlet temperature in fast reactor, oxide dispersion strengthened (ODS) ferritic-martensitic steels were developed as a long life fuel cladding. The improvement in formability and ductility, which are indispensable in the cold-rolling method for manufacturing cladding tube, were achieved by controlling the microstructure using techniques such as recrystallization heat-treatment and α to γ phase transformation. The ODS ferritic-martensitic cladding tubes manufactured using these techniques have the highest internal creep rupture strength in the world as ferritic stainless steels. Strength level approaches adequate value at 700degC, which meets the requirement for commercial fast reactors. (author)

  5. Selective oxidation of refractory sulfur compounds for the production of low sulfur transportation fuel

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Kwang-Eun; Kim, Tae-Wan; Kim, Joo-Wan; Chae, Ho-Jeong; Kim, Chul-Ung; Jeong, Soon-Yong [Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of); Park, Young-Kwon [University of Seoul, Seoul (Korea, Republic of)

    2013-03-15

    The current technologies for achieving low sulfur in diesel fuel are based on hydrotreating, which requires high temperature, high pressure and excessive supply of hydrogen. Oxidative desulfurization (ODS) is considered one of the promising new methods for super deep desulfurization, which could be carried out under very mild conditions (atmospheric pressure, <100 .deg.. C) without consumption of hydrogen. In this paper, development status of ODS process by major licensors are described as well as general concepts of ODS reaction. In addition, the ODS process has been categorized into single phasic and biphasic system according to the oxidants involved. Recent trends in both systems are reviewed in detail and future work is also proposed.

  6. Selective oxidation of refractory sulfur compounds for the production of low sulfur transportation fuel

    International Nuclear Information System (INIS)

    Jeong, Kwang-Eun; Kim, Tae-Wan; Kim, Joo-Wan; Chae, Ho-Jeong; Kim, Chul-Ung; Jeong, Soon-Yong; Park, Young-Kwon

    2013-01-01

    The current technologies for achieving low sulfur in diesel fuel are based on hydrotreating, which requires high temperature, high pressure and excessive supply of hydrogen. Oxidative desulfurization (ODS) is considered one of the promising new methods for super deep desulfurization, which could be carried out under very mild conditions (atmospheric pressure, <100 .deg.. C) without consumption of hydrogen. In this paper, development status of ODS process by major licensors are described as well as general concepts of ODS reaction. In addition, the ODS process has been categorized into single phasic and biphasic system according to the oxidants involved. Recent trends in both systems are reviewed in detail and future work is also proposed

  7. Transmission electron microscopy of oxide dispersion strengthened (ODS) molybdenum: effects of irradiation on material microstructure

    International Nuclear Information System (INIS)

    Baranwal, R.; Burke, M.G.

    2003-01-01

    Oxide dispersion strengthened (ODS) molybdenum has been characterized using transmission electron microscopy (TEM) to determine the effects of irradiation on material microstructure. This work describes the results-to-date from TEM characterization of unirradiated and irradiated ODS molybdenum. The general microstructure of the unirradiated material consists of fine molybdenum grains (< 5 (micro)m average grain size) with numerous low angle boundaries and isolated dislocation networks. 'Ribbon'-like lanthanum oxides are aligned along the working direction of the product form and are frequently associated with grain boundaries, serving to inhibit grain boundary and dislocation movement. In addition to the 'ribbons', discrete lanthanum oxide particles have also been detected. After irradiation, the material is characterized by the presence of nonuniformly distributed large (∼ 20 to 100 nm in diameter), multi-faceted voids, while the molybdenum grain size and oxide morphology appear to be unaffected by irradiation

  8. Material Flow and Oxide Particle Distributions in Friction-Stir Welded F/M-ODS Sheets

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Suk Hoon; Noh, Sanghoon; Jin, Hyun Ju; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    It is well known that uniform nano-oxide dispersoids act as pinning points to obstruct dislocation and grain boundary motion in ODS(Oxide dispersion strengthened) steel. However, these advantages will disappear while the material is subjected to the high temperature of conventional fusion welding. There is only limited literature available on the joining of ODS steels. Friction stir welding (FSW) is considered to be the best welding technique for welding ODS steels as the technique helps in retaining the homogeneous nano-oxide particles distributions in matrix. FSW is a solid.state, hot.shear joining process in which a rotating tool with a shoulder and terminating in a threaded pin, moves along the butting surfaces of two rigidly clamped plates placed on a backing plate. Heat generated by friction at the shoulder and to a lesser extent at the pin surface, softens the material being welded. Severe plastic deformation and flow of this plasticised metal occurs as the tool is translated along the welding direction. Material is transported from the front of the tool to the trailing edge where it is forged into a joint. Friction stir welding appears to be a very promising technique for the welding of FMS and ODS steels. This study found that, during FSW, the forward movement of the tool pin results in loose contact between the tool pin and the receding material on the advancing side.

  9. Mechanosynthesis of A Ferritic ODS (Oxide Dispersion Strengthened) Steel Containing 14% Chromium and Its Characterization

    Science.gov (United States)

    Rivai, A. K.; Dimyati, A.; Adi, W. A.

    2017-05-01

    One of the advanced materials for application at high temperatures which is aggressively developed in the world is ODS (Oxide Dispersion strengthened) steel. ODS ferritic steels are one of the candidate materials for future nuclear reactors in the world (Generation IV reactors) because it is able to be used in the reactor above 600 °C. ODS ferritic steels have also been developed for the interconnect material of SOFC (Solid Oxide Fuel Cell) which will be exposed to about 800 °C of temperature. The steel is strengthened by dispersing homogeneously of oxide particles (ceramic) in nano-meter sized in the matrix of the steel. Synthesis of a ferritic ODS steel by dispersion of nano-particles of yttrium oxide (yttria: Y2O3) as the dispersion particles, and containing high-chromium i.e. 14% has been conducted. Synthesis of the ODS steels was done mechanically (mechanosynthesis) using HEM (High Energy ball Milling) technique for 40 and 100 hours. The resulted samples were characterized using SEM-EDS (Scanning Electron Microscope-Energy Dispersive Spectroscope), and XRD (X-ray diffraction) to analyze the microstructure characteristics. The results showed that the crystal grains of the sample with 100 hours milling time was much smaller than the sample with 40 hours milling time, and some amount of alloy was formed during the milling process even for 40 hours milling time. Furthermore, the structure analysis revealed that some amount of iron atom substituted by a slight amount of chromium atom as a solid solution. The quantitative analysis showed that the phase mostly consisted of FeCr solid-solution with the structure was BCC (body-centered cubic).

  10. PET-modified red mud as catalysts for oxidative desulfurization reactions.

    Science.gov (United States)

    do Prado, Nayara T; Heitmann, Ana P; Mansur, Herman S; Mansur, Alexandra A; Oliveira, Luiz C A; de Castro, Cinthia S

    2017-07-01

    This work describes the synthesis of catalysts based on red mud/polyethylene terephthalate (PET) composites and their subsequent heat treatment under N 2 atmosphere. The materials were characterized by scanning electron microscopy (SEM), temperature programmed reduction (TPR), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric (TG) analysis and N 2 adsorption/desorption. The catalysts were evaluated in the oxidative desulfurization reaction of dibenzothiophene (DBT) in a biphasic system. The results indicated that the PET impregnation on red mud increased the affinity of the catalyst with the nonpolar phase (fuel), in which the contaminant was dissolved, allowing a higher conversion (up to 80%) and selectivity to the corresponding dibenzothiophene sulfone. The sulfone compound is more polar than DBT and diffused into the polar solvent as indicated by the data obtained via gas chromatography-mass spectrometry (GC-MS). Copyright © 2017. Published by Elsevier B.V.

  11. A novel [Bmim]PW/HMS catalyst with high catalytic performance for the oxidative desulfurization process

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Ling; Luo, Guangqing; Kang, Lihua; Zhu, Mingyuan; Dai, Bin [Shihezi University, Shihezi (China)

    2013-02-15

    To effectively reduce the sulfur content in model fuel, [Bmim]PW/HMS catalyst was synthesized through impregnating the hexagonal mesoporous silica (HMS) support by phosphotungstic acid (HPW) and ionic liquid [Bmim] HSO{sub 4}. Physical structure characterizations of the catalysts showed that HMS retained mesoporous structure, and [Bmim] PW was well dispersed on the support of HMS. The catalytic activity of the [Bmim]PW/HMS was evaluated in the oxidative desulfurization process, and the optimal reaction conditions including loading of the catalysts, reaction temperature, catalyst amount, O/S (H{sub 2}O{sub 2}/sulfur) molar ratio and agitation speed were investigated. Under the optimal reaction conditions, the conversion of benzothiophene (BT), dibenzothiophene (DBT) and 4, 6-dimethyldibenzothiophene (4, 6-DMDBT) could reach 79%, 98%, 88%, respectively.

  12. A novel [Bmim]PW/HMS catalyst with high catalytic performance for the oxidative desulfurization process

    International Nuclear Information System (INIS)

    Tang, Ling; Luo, Guangqing; Kang, Lihua; Zhu, Mingyuan; Dai, Bin

    2013-01-01

    To effectively reduce the sulfur content in model fuel, [Bmim]PW/HMS catalyst was synthesized through impregnating the hexagonal mesoporous silica (HMS) support by phosphotungstic acid (HPW) and ionic liquid [Bmim] HSO 4 . Physical structure characterizations of the catalysts showed that HMS retained mesoporous structure, and [Bmim] PW was well dispersed on the support of HMS. The catalytic activity of the [Bmim]PW/HMS was evaluated in the oxidative desulfurization process, and the optimal reaction conditions including loading of the catalysts, reaction temperature, catalyst amount, O/S (H 2 O 2 /sulfur) molar ratio and agitation speed were investigated. Under the optimal reaction conditions, the conversion of benzothiophene (BT), dibenzothiophene (DBT) and 4, 6-dimethyldibenzothiophene (4, 6-DMDBT) could reach 79%, 98%, 88%, respectively

  13. Consideration of the oxide particle-dislocation interaction in 9Cr-ODS steel

    Science.gov (United States)

    Ijiri, Yuta; Oono, N.; Ukai, S.; Yu, Hao; Ohtsuka, S.; Abe, Y.; Matsukawa, Y.

    2017-05-01

    The interaction between oxide particles and dislocations in a 9Cr-ODS ferritic steel is investigated by both static and in situ TEM observation under dynamic straining conditions and room temperature. The measured obstacle strength (?) of the oxide particles was no greater than 0.80 and the average was 0.63. The dislocation loops around some coarsened particles were also observed. The calculated obstacle strength by a stress formula of the Orowan interaction is nearly equaled to the average experimental value. Not only cross-slip system but also the Orowan interaction should be considered as the main interaction mechanism between oxide particles and dislocation in 9CrODS ferritic steel.

  14. Preparation of AAO-CeO2 nanotubes and their application in electrochemical oxidation desulfurization of diesel

    Science.gov (United States)

    Du, Xiaoqing; Yang, Yumeng; Yi, Chenxi; Chen, Yu; Cai, Chao; Zhang, Zhao

    2017-02-01

    The coaxial arrays of AAO-CeO2 NTs have been successfully galvanostatically deposited on an anode, characterized and adopted as a catalyst for removing organic sulfurs from diesel. The influence of the main electrochemical oxidation factors on the efficiency of desulfurization have also been investigated. The results show that the fabrication process of AAO-CeO2 NTs is accompanied by the formation of a new phase, namely Al3Ce, and the main oxidation products of the diesel are soluble inorganic sulphides, especially Ce2(SO4)3. When compared with dibenzothiophene and 4, 6-dimethyldibenzothiophene, benzothiophene is much more easily removed, with a removal efficiency that reaches 87.2%. Finally, a possible electrochemical oxidation desulfurization pathway for diesel is proposed.

  15. Heterogeneous oxidative desulfurization of diesel fuel catalyzed by mesoporous polyoxometallate-based polymeric hybrid.

    Science.gov (United States)

    Yang, Huawei; Jiang, Bin; Sun, Yongli; Zhang, Luhong; Huang, Zhaohe; Sun, Zhaoning; Yang, Na

    2017-07-05

    In this work, the simple preparation of novel polymer supported polyoxometallates (POMs) catalysts has been reported. Soluble task-specific cross-linked poly (ionic liquid) (PIL) was prepared with N,​N-​dimethyl-​dodecyl-​(4-​vinylbenzyl) ammonium chloride and divinylbenzene as co-monomers. The as-prepared cationic PILs were assembled with different commercial POMs to form the interlinked mesoporous catalysts, and the formation mechanism was provided. The catalytic oxidation activities of the catalysts were closely related to the formation pathway of their corresponding peroxide active species. The catalyst with H 2 W 12 O 42 10- as counterion, which exhibited the best activity in the oxidation of benzothiophene (BT) and dibenzothiophene (DBT) to sulfones in model oil with hydrogen peroxide (H 2 O 2 , 30wt%) as oxidant, was characterized by different techniques and systematically studied for its sulfur removal performance. As for the oxidative desulfurization of a real diesel, it was observed that almost all of the original sulfur compounds could be completely converted, and the catalyst could be reused for at least eight cycles without noticeable changes in both catalytic activity and chemical structure. In the end, a catalytic mechanism was put forward with the assistant of Raman analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Deep extractive and oxidative desulfurization of dibenzothiophene with C5H9NO·SnCl2 coordinated ionic liquid.

    Science.gov (United States)

    Li, Fa-tang; Kou, Cheng-guang; Sun, Zhi-min; Hao, Ying-juan; Liu, Rui-hong; Zhao, Di-shun

    2012-02-29

    A new C5H9NO·SnCl2 coordinated ionic liquid (IL) was prepared by reacting N-methyl-pyrrolidone with anhydrous SnCl2. Desulfurization of dibenzothiophene (DBT) via extraction and oxidation with C5H9NO·SnCl2 IL as extractant, H2O2 and equal mol of CH3COOH as oxidants was investigated. The Nernst partition coefficients k(N) of C5H9NO·SnCl2 IL for the DBT in n-octane was above 5.0, showing its excellent extraction ability. During the oxidative desulfurization process, the optimal molar ratio of H2O2/DBT was six. Sulfur removal of DBT in n-octane was 94.8% in 30 min at 30 °C under the conditions of H2O2/DBT molar ratio of six and V (IL):V (oil)=1:3. Moreover, the sulfur removal increased with increasing temperature because of the high reaction rate constant, low viscosity, and high solubility of dibenzothiophene-sulfone in the IL. The kinetics of oxidative desulfurization of DBT was also investigated, and the apparent activation energy was found to be 32.5 kJ/mol. The IL could be recycled six times without a significant decrease in activity. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. HRTEM Study of Oxide Nanoparticles in K3-ODS Ferritic Steel Developed for Radiation Tolerance

    Energy Technology Data Exchange (ETDEWEB)

    Hsiung, L; Fluss, M; Tumey, S; Kuntz, J; El-Dasher, B; Wall, M; Choi, W; Kimura, A; Willaime, F; Serruys, Y

    2009-11-02

    Crystal and interfacial structures of oxide nanoparticles and radiation damage in 16Cr-4.5Al-0.3Ti-2W-0.37 Y{sub 2}O{sub 3} ODS ferritic steel have been examined using high-resolution transmission electron microscopy (HRTEM) techniques. Oxide nanoparticles with a complex-oxide core and an amorphous shell were frequently observed. The crystal structure of complex-oxide core is identified to be mainly monoclinic Y{sub 4}Al{sub 2}O{sub 9} (YAM) oxide compound. Orientation relationships between the oxide and the matrix are found to be dependent on the particle size. Large particles (> 20 nm) tend to be incoherent and have a spherical shape, whereas small particles (< 10 nm) tend to be coherent or semi-coherent and have a faceted interface. The observations of partially amorphous nanoparticles and multiple crystalline domains formed within a nanoparticle lead us to propose a three-stage mechanism to rationalize the formation of oxide nanoparticles containing core/shell structures in as-fabricated ODS steels. Effects of nanoparticle size and density on cavity formation induced by (Fe{sup 8+} + He{sup +}) dual-beam irradiation are briefly addressed.

  18. Radiation response of ODS ferritic steels with different oxide particles under ion-irradiation at 550 °C

    Science.gov (United States)

    Song, Peng; Morrall, Daniel; Zhang, Zhexian; Yabuuchi, Kiyohiro; Kimura, Akihiko

    2018-04-01

    In order to investigate the effects of oxide particles on radiation response such as hardness change and microstructural evolution, three types of oxide dispersion strengthened (ODS) ferritic steels (named Y-Ti-ODS, Y-Al-ODS and Y-Al-Zr-ODS), mostly strengthened by Y-Ti-O, Y-Al-O and Y-Zr-O dispersoids, respectively, were simultaneously irradiated with iron and helium ions at 550 °C up to a damage of 30 dpa and a corresponding helium (He) concentration of ∼3500 appm to a depth of 1000-1300 nm. A single iron ion beam irradiation was also performed for reference. Transmission electron microscopy revealed that after the dual ion irradiation helium bubbles of 2.8, 6.6 and 4.5 nm in mean diameter with the corresponding number densities of 1.1 × 1023, 2.7 × 1022 and 3.6 × 1022 m-3 were observed in Y-Ti-ODS, Y-Al-ODS and Y-Al-Zr-ODS, respectively, while no such bubbles were observed after single ion irradiation. About 80% of intragranular He bubbles were adjacent to oxide particles in the ODS ferritic steels. Although the high number density He bubbles were observed in the ODS steels, the void swelling in Y-Ti-ODS, Y-Al-ODS and Y-Al-Zr-ODS was still small and estimated to be 0.13%, 0.53% and 0.20%, respectively. The excellent swelling resistance is dominantly attributed to the high sink strength of oxide particles that depends on the morphology of particle dispersion rather than the crystal structure of the particles. In contrast, no dislocation loops were produced in any of the irradiated steels. Nanoindentation measurements showed that no irradiation hardening but softening was found in the ODS ferritic steels, which was probably due to irradiation induced dislocation recovery. The helium bubbles in high number density never contributed to the irradiation hardening of the ODS steels at these irradiation conditions.

  19. Preparation of ionic liquid-modified SBA-15 doped with molybdovanadophosphoric acid for oxidative desulfurization

    International Nuclear Information System (INIS)

    Zhuang, Jiang Zhou; Jin, Xiao Yin; Shen, Xian Lin; Tan, Jun Jun; Nie, Long Hui; Xiang, Jian; Hu, Bing

    2015-01-01

    A series of catalysts, ionic liquid-modified SBA-15 (denoted ILSBA) doped with H 5 PMo 10 V 2 O 40 (HPMoV 2 ) have been synthesized and characterized by XRD, FT-IR, 1 H NMR, TG-DTA, and TEM. The catalyst was used for the removal of dibenzothiophene (DBT) in model oil combined with hydrogen peroxide (the oxidant) and acetonitrile (the phase-transfer agent). It was observed that the sulfur content of DBT can be reduced from 500 to 2 ppm by adjusting the amount of catalyst, the reaction temperatures and the reaction time. Besides, the catalyst activity for different sulfur compounds showed a huge difference which may be mainly affected by the electron densities of sulfur atom. Moreover, the catalyst can be recycled seven times without a significant loss in activity, which could be ascribed to the strong electrostatic interaction between ILSBA and HPMoV 2 . In addition, a postulated mechanism was proposed to reveal the oxidative desulfurization process

  20. Preparation of ionic liquid-modified SBA-15 doped with molybdovanadophosphoric acid for oxidative desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, Jiang Zhou; Jin, Xiao Yin; Shen, Xian Lin; Tan, Jun Jun; Nie, Long Hui; Xiang, Jian; Hu, Bing [Dept. of chool of Chemistry and Chemical Engineering, Hubei University of Technology, Wuhan (China)

    2015-07-15

    A series of catalysts, ionic liquid-modified SBA-15 (denoted ILSBA) doped with H{sub 5}PMo{sub 10}V{sub 2}O{sub 40} (HPMoV{sub 2}) have been synthesized and characterized by XRD, FT-IR, {sup 1}H NMR, TG-DTA, and TEM. The catalyst was used for the removal of dibenzothiophene (DBT) in model oil combined with hydrogen peroxide (the oxidant) and acetonitrile (the phase-transfer agent). It was observed that the sulfur content of DBT can be reduced from 500 to 2 ppm by adjusting the amount of catalyst, the reaction temperatures and the reaction time. Besides, the catalyst activity for different sulfur compounds showed a huge difference which may be mainly affected by the electron densities of sulfur atom. Moreover, the catalyst can be recycled seven times without a significant loss in activity, which could be ascribed to the strong electrostatic interaction between ILSBA and HPMoV{sub 2}. In addition, a postulated mechanism was proposed to reveal the oxidative desulfurization process.

  1. Texture evolution in Oxide Dispersion Strengthened (ODS) steel tubes during pilgering process

    Science.gov (United States)

    Vakhitova, E.; Sornin, D.; Barcelo, F.; François, M.

    2017-10-01

    Oxide Dispersion Strengthened (ODS) steels are foreseen as fuel cladding material in the coming generation of Sodium Fast Reactors (SFR). Cladding tubes are manufactured by hot extrusion and subsequent cold forming steps. In this study, a 9 wt% Cr ODS steel exhibiting α-γ phase transformation at high temperature is cold formed under industrial conditions with a large section reduction in two pilgering steps. The influence of pilgering process parameters and intermediate heat treatment on the microstructure evolution is studied experimentally using Electron Backscattering Diffraction (EBSD) and X-ray Diffraction (XRD) methods. Pilgered samples show elongated grains and a high texture formation with a preferential orientation along the rolling direction. During the heat treatment, grain morphology is recovered from elongated grains to almost equiaxed ones, while the well-known α-fiber texture presents an unexpected increase in intensity. The remarkable temperature stability of this fiber is attributed to a crystallographic structure memory effect during phase transformations.

  2. Mixing-assisted oxidative desulfurization of model sulfur compounds using polyoxometalate/H2O2 catalytic system

    Directory of Open Access Journals (Sweden)

    Angelo Earvin Sy Choi

    2016-07-01

    Full Text Available Desulfurization of fossil fuel derived oil is needed in order to comply with environmental regulations. Dibenzothiophene and benzothiophene are among the predominant sulfur compound present in raw diesel oil. In this study, mixing-assisted oxidative desulfurization of dibenzothiophene and benzothiophene were carried out using polyoxometalate/H2O2 systems and a phase transfer agent. The effects of reaction time (2–30 min and temperature (30–70 °C were examined in the oxidation of model sulfur compounds mixed in toluene. A pseudo first-order reaction kinetic model and the Arrhenius equation were utilized in order to evaluate the kinetic rate constant and activation energy of each catalyst tested in the desulfurization process. Results showed the order of catalytic activity and activation energy of the different polyoxometalate catalysts to be H3PW12O40 > H3PM12O40 > H4SiW12O40 for both dibenzothiophene and benzothiophene.

  3. Efficient H2O2/CH3COOH oxidative desulfurization/denitrification of liquid fuels in sonochemical flow-reactors.

    Science.gov (United States)

    Calcio Gaudino, Emanuela; Carnaroglio, Diego; Boffa, Luisa; Cravotto, Giancarlo; Moreira, Elizabeth M; Nunes, Matheus A G; Dressler, Valderi L; Flores, Erico M M

    2014-01-01

    The oxidative desulfurization/denitrification of liquid fuels has been widely investigated as an alternative or complement to common catalytic hydrorefining. In this process, all oxidation reactions occur in the heterogeneous phase (the oil and the polar phase containing the oxidant) and therefore the optimization of mass and heat transfer is of crucial importance to enhancing the oxidation rate. This goal can be achieved by performing the reaction in suitable ultrasound (US) reactors. In fact, flow and loop US reactors stand out above classic batch US reactors thanks to their greater efficiency and flexibility as well as lower energy consumption. This paper describes an efficient sonochemical oxidation with H2O2/CH3COOH at flow rates ranging from 60 to 800 ml/min of both a model compound, dibenzotiophene (DBT), and of a mild hydro-treated diesel feedstock. Four different commercially available US loop reactors (single and multi-probe) were tested, two of which were developed in the authors' laboratory. Full DBT oxidation and efficient diesel feedstock desulfurization/denitrification were observed after the separation of the polar oxidized S/N-containing compounds (S≤5 ppmw, N≤1 ppmw). Our studies confirm that high-throughput US applications benefit greatly from flow-reactors. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Fast high-temperature consolidation of Oxide-Dispersion Strengthened (ODS) steels: process, microstructure, precipitation, properties

    International Nuclear Information System (INIS)

    Boulnat, Xavier

    2014-01-01

    This work aims to lighten the understanding of the behavior of a class of metallic materials called Oxide-Dispersion Strengthened (ODS) ferritic steels. ODS steels are produced by powder metallurgy with various steps including atomization, mechanical alloying and high-temperature consolidation. The consolidation involves the formation of nanoparticles in the steel and various evolutions of the microstructure of the material that are not fully understood. In this thesis, a novel consolidation technique assisted by electric field called 'Spark Plasma Sintering' (SPS) or 'Field-Assisted Sintering Technique' (FAST) was assessed. Excellent mechanical properties were obtained by SPS, comparable to those of conventional hot isostatic pressed (HIP) materials but with much shorter processing time. Also, a broad range of microstructures and thus of tensile strength and ductility were obtained by performing SPS on either milled or atomized powder at different temperatures. However, SPS consolidation failed to avoid heterogeneous microstructure composed of ultrafine-grained regions surrounded by micron grains despite of the rapid consolidation kinetics. A multi-scale characterization allowed to understand and model the evolution of this complex microstructure. An analytical evaluation of the contributing mechanisms can explain the appearance of the complex grain structure and its thermal stability during further heat treatments. Inhomogeneous distribution of plastic deformation in the powder is argued to be the major cause of heterogeneous recrystallization and further grain growth during hot consolidation. Even if increasing the solute content of yttrium, titanium and oxygen does not impede abnormal growth, it permits to control the fraction and the size of the retained ultrafine grains, which is a key-factor to tailor the mechanical properties. Since precipitation through grain boundary pinning plays a significant role on grain growth, a careful

  5. Development of accident tolerant FeCrAl-ODS steels utilizing Ce-oxide particles dispersion

    Science.gov (United States)

    Shibata, Hiroki; Ukai, Shigeharu; Oono, Naoko H.; Sakamoto, Kan; Hirai, Mutsumi

    2018-04-01

    FeCrAl-ODS ferritic steels with Ce-oxide dispersion instead of Y-oxide were produced for the accident tolerant fuel cladding of the light water reactor. Excess oxygen (Ex.O) was added to improve the mechanical property. The tensile strength at Ex.O = 0 is around 200 MPa at 700 °C, mainly owing to dispersed Ce2O3 particles in less than 10 nm size. The formation of the fine Ce2O3 particles is dominated by a coherent interface with ferritic matrix. With increasing Ex.O, an increased of number density of coarser Ce-Al type oxide particles over 10 nm size is responsible for the improvement of the tensile strength. Change of the type of oxide particle, CeO2, Ce2O3, CeAlO3, Al2O3, in FeCrAl-ODS steel was thermodynamically analyzed as a parameter of Ex.O.

  6. Oxidative desulfurization-fluorination of thioethers. Application for the synthesis of fluorinated nitrogen containing building blocks.

    Science.gov (United States)

    Hugenberg, Verena; Fröhlich, Roland; Haufe, Günter

    2010-12-21

    An oxidative desulfurization-fluorination protocol has been used to synthesize (2S)-2-(difluoromethyl)-N-tosylpyrrolidine (6a) and (2S)-2-(trifluoromethyl)-N-tosylpyrrolidine (7a) from the (2S)-prolinol-derived (2S)-2-(4-chlorophenylthiomethyl)-N-tosylpyrrolidine (9) or (2S)-2-(dithian-2-yl)-N-tosylpyrrolidine (5). Efforts to prepare 3,3-difluoroalanine similarly from an N-protected S-aryl-cysteine ester 17 gave only traces of the target compound 18. Instead, an unique N-(α,α-difluorobenzyl)-N-α',α'-dibromoglycine ester 19 was formed by an unprecedented sequence of reaction steps. A plausible mechanism is suggested involving a sulfur-assisted deoxygenation-difluorination of an imino oxygen and a haloform reaction like carbon-carbon bond fission as key-steps. Efforts to prepare (2S)-2-(fluoromethyl)-N-tosylpyrrolidine (12) from (2S)-N-tosylprolinol (3) by treatment with Fluolead™ (1-tert-butyl-4-trifluorosulfanyl-3,5-dimethylbenzene) gave only 5% of the target compound, but 95% of (3R)-3-fluoro-N-tosylpiperidine (11a) by ring enlargement.

  7. Influence of surface phenomena in oxidative desulfurization with WOx/ZrO2 catalysts

    Science.gov (United States)

    Torres-García, E.; Canizal, G.; Velumani, S.; Ramírez-Verduzco, L. F.; Murrieta-Guevara, F.; Ascencio, J. A.

    2004-12-01

    Oil refinery related catalysis, particularly hydro desulfurization is viewed as a mature technology, but still we view that more efforts have to be made to boost the efficiency of the existing catalysts. So in this article we report the use of WOx/ZrO2 catalysts for the oxidation of dibenzothiophene (DBT) as a more effective material in nanometer scales. The WOx/ZrO2 samples were prepared by solid impregnation of ZrO2-x(OH)2x with ammonium metatungstate solution maintaining the pH at 10. Detailed structural and surface morphological analyses were carried out using Raman spectroscopy and Atomic force microscopy. In order to understand the catalytic activity which is largely influenced by the surface morphology, an interpretation based on the experimental results is given. The results showed an important correlation between the catalytic efficiency with the morphology of the surface which is identified as arrays of planes with steps of around 10 nm with the structures showing faceting with a preferential angle of 90°. It was established that when the number of W atoms in the surface increase the catalytic efficiency also increases. Thus we conclude that the material efficiency as a catalyst is directly related with the surface structure.

  8. Attapulgite-CeO2/MoS2 ternary nanocomposite for photocatalytic oxidative desulfurization

    Science.gov (United States)

    Li, Xiazhang; Zhang, Zuosong; Yao, Chao; Lu, Xiaowang; Zhao, Xiaobing; Ni, Chaoying

    2016-02-01

    Novel attapulgite(ATP)-CeO2/MoS2 ternary nanocomposites were synthesized by microwave assisted assembly method. The structures of the nanocomposites were characterized by XRD, FT-IR, UV-vis, XPS and in situ TEM. The photocatalytic activities of ATP-CeO2/MoS2 composites were investigated by degradating dibenzothiophene (DBT) in gasoline under visible light irradiation. The effect of the mass ratio of CeO2 to MoS2 on photocatalytic activity was investigated. The results indicate that the three-dimensional network structure is firmly constructed by ATP skeleton, CeO2 particles and MoS2 nanosheet which effectively increase the surface area of the composites and promote the separation of electrons and holes by resulting electronic transmission channels of multi-channel in space. The degradation rate of DBT can reach 95% under 3 h irradiation when the mass ratio of CeO2/MoS2 is 4/10. A plausible mechanism for the photocatalytic oxidative desulfurization of this nanocomposite is put forward.

  9. Helium behavior in oxide dispersion strengthened (ODS) steel: Insights from ab initio modeling

    Science.gov (United States)

    Sun, Dan; Li, Ruihuan; Ding, Jianhua; Huang, Shaosong; Zhang, Pengbo; Lu, Zheng; Zhao, Jijun

    2018-02-01

    Using first-principles calculations, we systemically investigate the energetics and stability behavior of helium (He) atoms and small Hen (n = 2-4) clusters inside oxide dispersion strengthened (ODS) steel, as well as the incorporation of large amount of He atoms inside Y2O3 crystal. From the energetic point of view, He atom inside Y2O3 cluster is most stable, followed by the interstitial sites at the α-Fe/Y2O3 interface, and the tetrahedral interstitial sites inside α-Fe region. We further consider Hen (n = 2-4) clusters at the tetrahedral interstitial site surrounded by four Y atoms, which is the most stable site in the ODS steel model. The incorporation energies of all these Hen clusters are lower than that of single He atom in α-Fe, while the binding energy between two He atoms is relatively small. With insertion of 15 He atoms into 80-atom unit cell of Y2O3 crystal, the incorporation energy of He atoms is still lower than that of He4 cluster in α-Fe crystal. These theoretical results suggest that He atoms tend to aggregate inside Y2O3 clusters or at the α-Fe/Y2O3 interface, which is beneficial to prevent the He embrittlement in ODS steels.

  10. Microscopy of Alloy Formation on Arc Plasma Sintered Oxide Dispersion Strengthen (ODS) Steel

    Science.gov (United States)

    Bandriyana, B.; Sujatno, A.; Salam, R.; Dimyati, A.; Untoro, P.

    2017-07-01

    The oxide dispersed strengthened (ODS) alloys steel developed as structure material for nuclear power plants (NPP) has good resistant against creep due to their unique microstructure. Microscopy investigation on the microstructure formation during alloying process especially at the early stages was carried out to study the correlation between structure and property of ODS alloys. This was possible thanks to the arc plasma sintering (APS) device which can simulate the time dependent alloying processes. The ODS sample with composition of 88 wt.% Fe and 12 wt.% Cr powder dispersed with 1 wt.% ZrO2 nano powder was mixed in a high energy milling, isostatic compressed to form sample coins and then alloyed in APS. The Scanning Electron Microscope (SEM) with X-ray Diffraction Spectroscopy (EDX) line scan and mapping was used to characterize the microstructure and elemental composition distribution of the samples. The alloying process with unification of each Fe and Cr phase continued by the alloying formation of Fe-Cr by inter-diffusion of both Fe and Cr and followed by the improvement of the mechanical properties of hardness.

  11. An oxidative desulfurization method using ultrasound/Fenton's reagent for obtaining low and/or ultra-low sulfur diesel fuel

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Yongchuan; Qi, Yutai [Department of Applied Chemistry, School of Science, Harbin Institute of Technology, Harbin 115001 (China); Zhao, Dezhi [Department of Petroleum Chemical Engineering, Liaoning Shihua University, Fushun 113001 (China); Zhang, Huicheng [Fushun Research Institute of Petroleum and Petrochemicals of SINOPEC Corp., Fushun 113001 (China)

    2008-10-15

    The total development trend in the world is towards continuously lower of sulfur content as a quality standard of diesel fuels. Integrating of an oxidative desulfurization unit with a conventional hydrotreating unit can bring benefits to producing low and/or ultra-low sulfur diesel fuels. Using the hydrotreated Middle East diesel fuel as a feedstock, four processes of the oxidative desulfurization have been studied: a hydrogen peroxide-acetic acid system and a Fenton's reagent system both without/with ultrasound. Results showed that the oxidative desulfurization reaction mechanics fitted apparent first-order kinetics. The addition of Fenton's reagent could enhance the oxidative desulfurization efficiency for diesel fuels and sono-oxidation treatment in combination with Fenton's reagent shows a good synergistic effect. Under our best operating condition for the oxidative desulfurization: temperature 313 K, ultrasonic power 200 W, ultrasonic frequency 28 kHz, Fe{sup 2+}/H{sub 2}O{sub 2} 0.05 mol/mol, pH 2.10 in aqueous phase and reaction time 15 min, the sulfur content in the diesel fuels was decreased from 568.75 {mu}g/g to 9.50 {mu}g/g. (author)

  12. Development of a portable, modular unit for the optimization of ultrasound-assisted oxidative desulfurization of diesel

    Science.gov (United States)

    Wan, Meng-Wei

    Due to the stringent rules requiring ultra-low sulfur content in diesel fuels, it is necessary to develop alternative methods of desulfurization of fossil fuel derived oil, such as diesel. Current technology is not sufficient to solve this problem. Ultrasound applied to oxidative desulfurization which combined three complementary techniques: ultrasonication, phase transfer catalysis (PTC) and transition metal catalyzed oxidation, has accomplished high sulfur removal in a short contact time at ambient temperature and atmospheric pressure. This research has successfully demonstrated that the higher oxidation efficiency of BT to BTO and free of any by-products by using tetraoctylammonium fluoride as phase transfer agent. The oxidation rate of BT to BTO increased with increasing the carbon chain length of QAS cations. Under the same length of carbon chain, the oxidation rate of BT to BTO increased with decreasing the molecular size of QAS anions. Moreover, for diesel fuels containing various levels of sulfur content, UAOD process followed by solvent extraction has demonstrated that the sulfur reduction can reach above 95 % removal efficiency or final sulfur content below 15 ppm in mild condition. For large-scale commercial production, this research has successfully developed and operated a continuous desulfurization unit, which consists of a sonoractor, an RF amplifier, a function generator, a pretreatment tank, and a pipeline system. A single unit only needed 2' x 4' x 1' space for installation. The results indicated that the remarkable 92% removal efficiency for the sulfur in marine logistic diesel, even at a treatment rate as high as 25 lb/hour which is approximately 2 barrels per day. Therefore, this sonoreactor demonstrated the feasibility of large-scale operation even in a relatively small installation with low capital investment and maintenance cost. It also ensures the safety considerations by operating with diluted hydrogen peroxide under ambient temperature

  13. Ultrasound-assisted oxidative desulfurization process of liquid fuel by phosphotungstic acid encapsulated in a interpenetrating amine-functionalized Zn(II)-based MOF as catalyst.

    Science.gov (United States)

    Afzalinia, Ahmad; Mirzaie, Abbas; Nikseresht, Ahmad; Musabeygi, Tahereh

    2017-01-01

    In this work, ultrasound-assisted oxidative desulfurization (UAOD) of liquid fuels performed with a novel heterogeneous highly dispersed Keggin-type phosphotungstic acid (H 3 PW 12 O 40 , PTA) catalyst that encapsulated into an amino-functionalized MOF (TMU-17-NH 2 ). The prepared composite exhibits high catalytic activity and reusability in oxidative desulfurization of model fuel. Ultrasound-assisted oxidative desulfurization (UAOD) is a new way to performed oxidation reaction of sulfur-contain compounds rapidly, economically, environment-friendly and safely, under mild conditions. Ultrasound waves can be apply as an efficient tool to decrease the reaction time and improves oxidative desulfurization system performance. PTA@TMU-17-NH 2 could be completely performed desulfurization of the model oil by 20mg of catalyst, O/S molar ratio of 1:1 in presence of MeCN as extraction solvent. The obtained results indicated that the conversions of DBT to DBTO 2 achieve 98% after 15min in ambient temperature. In this work, we prepared TMU-17-NH 2 and PTA/TMU-17-NH 2 composite by ultrasound irradiation for first time and employed in UAOD process. Prepared catalyst exhibit an excellent reusability without PTA leaching and loss of activity. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Oxidative desulfurization of synthetic diesel using supported catalysts. Part 3. Support effect on vanadium-based catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Cedeno-Caero, Luis; Gomez-Bernal, Hilda; Fraustro-Cuevas, Adriana; Guerra-Gomez, Hector D.; Cuevas-Garcia, Rogelio [UNICAT, Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Cd. Universitaria 04510, Mexico D.F. (Mexico)

    2008-04-15

    Oxidesulfurization (ODS) of benzothiophenic compounds prevailing in diesel was conducted with hydrogen peroxide in presence of various catalysts, using a model diesel and actual diesel fuel. ODS activities of dibenzothiophenes (DBTs) in hexadecane for a series of V{sub 2}O{sub 5} catalysts supported on alumina, titania, ceria, niobia and silica, were evaluated. Results show that the oxidation activity of DBTs depends on the support used. It was observed that the sulfone yield is not proportional to textural properties or V content. For all catalysts, ODS of benzothiophene (BT), dibenzothiophene (DBT), 4-methyl dibenzothiophene (4-MDBT) and 4,6-dimethyl dibenzothiophene (4,6-DMDBT) decreased in the following order: DBT > 4-MDBT > 4,6-DMDBT > BT. This trend does not depend on the catalyst used or the textural properties of the catalysts and supports. In presence of indole ODS activities diminish, except with catalysts supported on alumina-titania mixed oxide, whereas with V{sub 2}O{sub 5}/TiO{sub 2} catalyst the performance is the highest. ODS of Mexican diesel fuel was carried out in presence of this catalyst and S level was diminished in about 99%. (author)

  15. Cyclic oxidation of coated Oxide Dispersion Strengthened (ODS) alloys in high velocity gas streams at 1100 deg C

    Science.gov (United States)

    Gedwill, M. A.

    1978-01-01

    Several overlay coatings on ODS NiCrAl's were tested in Mach 1 and Mach 0.3 burner rigs to examine oxidation and thermal fatigue performance. The coatings were applied by various methods. Based on weight change, macroscopic, and metallographic observations in Mach 1 tests Nascoat 70 on TD-NiCrAl exhibited the best oxidation resistance. In Mach 0.3 tests PWA 267 and ATD-1, about equally, were the best coatings on YD-NiCrAl (Nascoat 70 was not tested in Mach 0.3 rigs).

  16. Novel polyoxometalate silica nano-sized spheres: efficient catalysts for olefin oxidation and the deep desulfurization process.

    Science.gov (United States)

    Nogueira, Lucie S; Ribeiro, Susana; Granadeiro, Carlos M; Pereira, Eulália; Feio, Gabriel; Cunha-Silva, Luís; Balula, Salete S

    2014-07-07

    A novel method to prepare silica nano-sized particles incorporating polyoxometalates was developed leading to a new efficient heterogeneous oxidative catalyst. Zinc-substituted polyoxotungstate [PW11Zn(H2O)O39](5-) (PW11Zn) was encapsulated into silica nanoparticles using a cross-linked organic-inorganic core, performed through successive spontaneous reactions in water. The potassium salt of PW11Zn and the composite formed, PW11Zn-APTES@SiO2, were characterized by a myriad of solid-state methods such as FT-IR, FT-Raman, (31)P and (13)C CP/MAS solid-state NMR, elemental analysis and SEM-EDS, confirming the integrity of the PW11Zn structure immobilized in the silica nanoparticles. The new composite has shown to be a versatile catalyst for the oxidation of olefins and also to catalyze the desulfurization of a model oil using H2O2 as the oxidant and acetonitrile as the solvent. The novel composite material was capable of being recycled without significant loss of activity and maintaining its structural stability for consecutive desulfurization and olefin oxidative cycles.

  17. Copper-catalyzed oxidative desulfurization-oxygenation of thiocarbonyl compounds using molecular oxygen: an efficient method for the preparation of oxygen isotopically labeled carbonyl compounds.

    Science.gov (United States)

    Shibahara, Fumitoshi; Suenami, Aiko; Yoshida, Atsunori; Murai, Toshiaki

    2007-06-21

    A novel copper-catalyzed oxidative desulfurization reaction of thiocarbonyl compounds, using molecular oxygen as an oxidant and leading to formation of carbonyl compounds, has been developed, and the utility of the process is demonstrated by its application to the preparation of a carbonyl-18O labeled sialic acid derivative.

  18. Optimized Ultrasound-Assisted Oxidative Desulfurization Process of Simulated Fuels over Activated Carbon-Supported Phosphotungstic Acid

    Directory of Open Access Journals (Sweden)

    Peniel Jean Gildo

    2018-01-01

    Full Text Available Recent technological advancements respond to the call to minimize/eliminate emissions to the atmosphere. However, on the average, fuel oils which is one of the major raw materials, is found to increase in sulfur concentration due to a phenomenon called thermal maturation. As such, a deeper desulfurization process is needed to obtain low/ultra-low sulfur fuel oils. In the present study, the ultrasound assisted oxidative desulfurization (UAOD processes using the H2O2 and HPW-AC oxidizing system applied to simulated fuel (~2800 ppm sulfur in the form of dibenzothiophene, benzothiophene, and thiophene dissolved in toluene, were optimized. After the pre-saturation of the HPW-AC with the simulated fuel, H2O2 was added just before the reaction was commenced under ultrasonic irradiation. After the application of both 2k-factorial design of experiment for screening and Face-Centered Design of Experiment for optimization, it was found that 25.52 wt% of H2O2 concentration, 983.9 mg of catalyst dose, 9.52 mL aqueous phase per 10 mL of the organic phase and 76.36 minutes of ultrasonication time would render 94.74% oxidation of the sulfur compounds in the simulated fuel. After the application of the optimized parameters to kerosene and employing a 4-cycle extraction using acetonitrile, 99% of the original sulfur content were removed from the kerosene using the UAOD optimized parameters. The desulfurization process resulted in a low-sulfur kerosene which retained its basic fuel properties such as density, viscosity and calorific value.

  19. Indium-Catalyzed Reductive Dithioacetalization of Carboxylic Acids with Dithiols: Scope, Limitations, and Application to Oxidative Desulfurization.

    Science.gov (United States)

    Nishino, Kota; Minato, Kohei; Miyazaki, Takahiro; Ogiwara, Yohei; Sakai, Norio

    2017-04-07

    In this study an InI 3 -TMDS (1,1,3,3-tetramethyldisiloxane) reducing system effectively catalyzed the reductive dithioacetalization of a variety of aromatic and aliphatic carboxylic acids with 1,2-ethanedithiol or 1,3-propanedithiol leading to the one-pot preparation of either 1,3-dithiolane derivatives or a 1,3-dithiane derivative. Also, the intact indium catalyst continuously catalyzed the subsequent oxidative desulfurization of an in situ formed 1,3-dithiolane derivative, which led to the preparation of the corresponding aldehydes.

  20. Phosphotungstic acid encapsulated in the mesocages of amine-functionalized metal-organic frameworks for catalytic oxidative desulfurization.

    Science.gov (United States)

    Wang, Xu-Sheng; Huang, Yuan-Biao; Lin, Zu-Jin; Cao, Rong

    2014-08-21

    Highly dispersed Keggin-type phosphotungstic acid (H3PW12O40, PTA) encapsulated in the mesocages of amine-functionalized metal-organic frameworks MIL-101(Cr)-NH2 has been prepared by an anion-exchange method. PTA anions (PW12O40(3-)) are stabilized in the mesocages via the electrostatic interaction with amino groups of the MIL-101(Cr)-NH2. The obtained catalyst (denoted PTA@MIL-101(Cr)-NH2) exhibits high catalytic activity in the extractive and catalytic oxidative desulfurization (ECODS) system under mild conditions. Moreover, it can be easily recovered and recycled several times without leaching and loss of activity.

  1. Novel Methods for Desulfurization of Fuel Oils

    OpenAIRE

    H. Hosseini

    2012-01-01

    Because of the requirement for low sulfur content of fuel oils, it is necessary to develop alternative methods for desulfurization of heavy fuel oil. Due to the disadvantages of HDS technologies such as costs, safety and green environment, new methods have been developed. Among these methods is ultrasoundassisted oxidative desulfurization. Using ultrasound-assisted oxidative desulfurization, compounds such as benzothiophene and dibenzothiophene can be oxidized. As an alterna...

  2. Species Differences in the Oxidative Desulfurization of a Thiouracil-Based Irreversible Myeloperoxidase Inactivator by Flavin-Containing Monooxygenase Enzymes.

    Science.gov (United States)

    Eng, Heather; Sharma, Raman; Wolford, Angela; Di, Li; Ruggeri, Roger B; Buckbinder, Leonard; Conn, Edward L; Dalvie, Deepak K; Kalgutkar, Amit S

    2016-08-01

    N1-Substituted-6-arylthiouracils, represented by compound 1 [6-(2,4-dimethoxyphenyl)-1-(2-hydroxyethyl)-2-thioxo-2,3-dihydropyrimidin-4(1H)-one], are a novel class of selective irreversible inhibitors of human myeloperoxidase. The present account is a summary of our in vitro studies on the facile oxidative desulfurization in compound 1 to a cyclic ether metabolite M1 [5-(2,4-dimethoxyphenyl)-2,3-dihydro-7H-oxazolo[3,2-a]pyrimidin-7-one] in NADPH-supplemented rats (t1/2 [half-life = mean ± S.D.] = 8.6 ± 0.4 minutes) and dog liver microsomes (t1/2 = 11.2 ± 0.4 minutes), but not in human liver microsomes (t1/2 > 120 minutes). The in vitro metabolic instability also manifested in moderate-to-high plasma clearances of the parent compound in rats and dogs with significant concentrations of M1 detected in circulation. Mild heat deactivation of liver microsomes or coincubation with the flavin-containing monooxygenase (FMO) inhibitor imipramine significantly diminished M1 formation. In contrast, oxidative metabolism of compound 1 to M1 was not inhibited by the pan cytochrome P450 inactivator 1-aminobenzotriazole. Incubations with recombinant FMO isoforms (FMO1, FMO3, and FMO5) revealed that FMO1 principally catalyzed the conversion of compound 1 to M1. FMO1 is not expressed in adult human liver, which rationalizes the species difference in oxidative desulfurization. Oxidation by FMO1 followed Michaelis-Menten kinetics with Michaelis-Menten constant, maximum rate of oxidative desulfurization, and intrinsic clearance values of 209 μM, 20.4 nmol/min/mg protein, and 82.7 μl/min/mg protein, respectively. Addition of excess glutathione essentially eliminated the conversion of compound 1 to M1 in NADPH-supplemented rat and dog liver microsomes, which suggests that the initial FMO1-mediated S-oxygenation of compound 1 yields a sulfenic acid intermediate capable of redox cycling to the parent compound in a glutathione-dependent fashion or undergoing further oxidation to a more

  3. A non-chemically selective top-down approach towards the preparation of hierarchical TS-1 zeolites with improved oxidative desulfurization catalytic performance.

    Science.gov (United States)

    Du, Shuting; Chen, Xiaoxin; Sun, Qiming; Wang, Ning; Jia, Mingjun; Valtchev, Valentin; Yu, Jihong

    2016-02-28

    Hierarchical TS-1 zeolites with secondary macropores have been successfully prepared by using two different fluoride-containing chemical etching post-treated routes. Hierarchical TS-1 zeolites exhibited a chemical composition similar to that of the parent material and showed remarkably enhanced catalytic activity in oxidative desulfurization reaction.

  4. Assessment and comparison of oxides grown on 304l ods steel and 304l ss in water environment in supercritical conditions

    International Nuclear Information System (INIS)

    Mihalache, M.; Dinu, A.; Fulger, M.; Zhou, Z.; Mihalache, M.

    2013-01-01

    In order to fulfil superior cladding for new reactor generation G IV, the austenitic 3 04 L stainless steel was improved by oxide dispersion strengthening (ODS), using two nano-oxides: titanium and yttrium oxides. The behaviour of the new material resulted, 304 ODS, in water at supercritical temperature of about 550 O C and 25 MPa pressure, was considered. The oxidation kinetics by weigh gain measurements for both materials have been estimated and compared. The weight gain of ODS samples is higher than basic austenitic steel up to 1320 hours. The oxides developed on the ODS samples in SCPW are layered and more uniform than in 304 L SS. The protectively character of oxide films was estimated by different techniques. The morphology of oxide surface, the layering and chemical formula of oxides films were investigated by scanning electron microscopy (SEM), Energy Dispersion X-Ray Spectrometry (EDS), electrochemical impedance spectrometry (EIS) and by Small Angle X-ray Diffraction (SAXD). 1. (authors)

  5. Characterisation of high-temperature damage mechanisms of oxide dispersion strengthened (ODS) ferritic steels

    International Nuclear Information System (INIS)

    Salmon-Legagneur, Hubert

    2017-01-01

    The development of the fourth generation of nuclear power plants relies on the improvement of cladding materials, in order to achieve resistance to high temperature, stress and irradiation dose levels. Strengthening of ferritic steels through nano-oxide dispersion allows obtaining good mechanical strength at high temperature and good resistance to irradiation induced swelling. Nonetheless, studies available from open literature evidenced an unusual creep behavior of these materials: high anisotropy in time to rupture and flow behavior, low ductility and quasi-inexistent tertiary creep stage. These phenomena, and their still unclear origin are addressed in this study. Three 14Cr ODS steels rods have been studied. Their mechanical behavior is similar to those of other ODS steels from open literature. During creep tests, the specimens fractured by through crack nucleation and propagation from the lateral surfaces, followed by ductile tearing once the critical stress intensity factor was reached at the crack tip. Tensile and creep properties did not depend on the chemical environment of specimens. Crack propagation tests performed at 650 C showed a low value of the stress intensity factor necessary to start crack propagation. The cracks followed an intergranular path through the smaller-grained regions, which partly explains the anisotropy of high temperature strength. Notched specimens have been used to study the impact of the main loading parameters (deformation rate, temperature, stress triaxiality) on macroscopic crack initiation and stable propagation, from the central part of the specimens. These tests allowed revealing cavities created during high temperature loading, but unexposed to the external environment. These cavities showed a high chemical reactivity of the free surfaces in this material. The performed tests also evidenced different types of grain boundaries, which presented different damage development behaviors, probably due to differences in local

  6. Study of the stability of the nanometer-sized oxides dispersed in ODS steels under ion irradiations

    International Nuclear Information System (INIS)

    Lescoat, M.-L.

    2012-01-01

    Oxide Dispersion Strengthened (ODS) Ferritic-Martensitic (FM) alloys are expected to play an important role as cladding materials in Generation IV sodium fast reactors operating in extreme temperature (400-500 C) and irradiation conditions (up to 200 dpa). Since nano-oxides give ODS steels their high temperature strength, the stability of these particles is an important issue. The present study evaluates the radiation response of nano-oxides by the use of in-situ and ex-situ ion irradiations performed on both Fe18Cr1W0,4Ti +0,3 Y 2 O 3 and Fe18Cr1W0,4Ti + 0.3 MgO ODS steels. In particular, the results showed that Y-Ti-O nano-oxides are quite stable under very high irradiation dose, namely 219 dpa at 500 C, and that the oxide interfacial structures are likely playing an important role on the behavior under irradiation (oxide stability and point defect recombination. (author) [fr

  7. Preparation of WO3/g-C3N4 composites and their application in oxidative desulfurization

    International Nuclear Information System (INIS)

    Zhao, Rongxiang; Li, Xiuping; Su, Jianxun; Gao, Xiaohan

    2017-01-01

    Highlights: • The WO 3 /g-C 3 N 4 was successfully synthesized through simple calcination. • The process is simple and the cost raw materials is cheap. • The WO 3 /g-C 3 N 4 firstly applied to ODS. • The desulpurization rate of WO 3 /g-C 3 N 4 may attach to 91.2%. • Five recycles of WO 3 /g-C 3 N 4 still attach to 89.5% due to heterogeneous catalysis. - Abstract: WO 3 /graphitic carbon nitride (g-C 3 N 4 ) composites were successfully synthesized through direct calcining of a mixture of WO 3 and g-C 3 N 4 at 400 °C for 2 h. The WO 3 was prepared by calcination of phosphotungstic acid at 550 °C for 4 h, and the g-C 3 N 4 was obtained by calcination of melamine at 520 °C for 4 h. The WO 3 /g-C 3 N 4 composites were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and Brunner−Emmett−Teller analysis (BET). The WO 3 /g-C 3 N 4 composites exhibited stronger XRD peaks of WO 3 and g-C 3 N 4 than the WO 3 and pure g-C 3 N 4 . In addition, two WO 3 peaks at 25.7° and 26.6° emerged for the 36% −WO 3 /g-C 3 N 4 composite. This finding indicated that WO 3 was highly dispersed on the surface of the g-C 3 N 4 nanosheets and interacted with the nanosheets, which resulted in the appearance of (012) and (022) planes of WO 3 . The WO 3 /g-C 3 N 4 composite also exhibited a larger specific surface area and higher degree of crystallization than WO 3 or pure g-C 3 N 4 , which resulted in high catalytic activity of the catalyst. Desulfurization experiments demonstrated that the desulfurization rate of dibenzothiophene (DBT) in model oil reached 91.2% under optimal conditions. Moreover, the activity of the catalyst was not significantly decreased after five recycles.

  8. Creep and rupture of an ODS alloy with high stress rupture ductility. [Oxide Dispersion Strengthened

    Science.gov (United States)

    Mcalarney, M. E.; Arsons, R. M.; Howson, T. E.; Tien, J. K.; Baranow, S.

    1982-01-01

    The creep and stress rupture properties of an oxide (Y2O3) dispersion strengthened nickel-base alloy, which also is strengthened by gamma-prime precipitates, was studied at 760 and 1093 C. At both temperatures, the alloy YDNiCrAl exhibits unusually high stress rupture ductility as measured by both elongation and reduction in area. Failure was transgranular, and different modes of failure were observed including crystallographic fracture at intermediate temperatures and tearing or necking almost to a chisel point at higher temperatures. While the rupture ductility was high, the creep strength of the alloy was low relative to conventional gamma prime strengthened superalloys in the intermediate temperature range and to ODS alloys in the higher temperature range. These findings are discussed with respect to the alloy composition; the strengthening oxide phases, which are inhomogeneously dispersed; the grain morphology, which is coarse and elongated and exhibits many included grains; and the second phase inclusion particles occurring at grain boundaries and in the matrix. The creep properties, in particular the high stress dependencies and high creep activation energies measured, are discussed with respect to the resisting stress model of creep in particle strengthened alloys.

  9. Desulfurization of fuel oils using an advanced oxidation method; Desulfuracion de combustibles usando un metodo de oxidacion avanzada

    Energy Technology Data Exchange (ETDEWEB)

    Flores Velazquez, Roberto; Rodas Grapain, Arturo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2008-07-01

    In the present work, the oxidative desulfurization of fuel oils assisted by ultrasound was analyzed. It was studied the effect of hydrogen peroxide concentration, the fuel oil to aqueous solution volumetric ratio, and type of catalyst. The Fenton-like catalysts studied were ferric chloride and copper sulfate. [Spanish] En esta investigacion se analiza la desulfuracion oxidativa de combustoleo asistida con ultrasonido. Tambien se estudia el efecto de la concentracion de peroxido de hidrogeno (H{sub 2}O{sub 2}), la relacion volumetrica combustoleo/solucion acuosa y el tipo de catalizador. Los catalizadores tipo Fenton que se estudiaron fueron el cloruro ferrico (FeCl{sub 3}) y el sulfato de cobre (CuSO{sub 4}).

  10. Attapulgite-CeO{sub 2}/MoS{sub 2} ternary nanocomposite for photocatalytic oxidative desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiazhang, E-mail: lixiazhang509@163.com [Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164 (China); Jiangsu Key Laboratory for Environment Functional Materials, Suzhou University of Science and Technology, Suzhou 215009 (China); W.M.Keck Center for Advanced Microscopy and Microanalysis, University of Delaware, Newark, DE 19716 (United States); Zhang, Zuosong [School of Materials Science and Engineering, Changzhou University, Changzhou 213164 (China); Yao, Chao [Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164 (China); Lu, Xiaowang [School of Materials Science and Engineering, Changzhou University, Changzhou 213164 (China); Zhao, Xiaobing [School of Materials Science and Engineering, Changzhou University, Changzhou 213164 (China); Jiangsu Key Laboratory for Environment Functional Materials, Suzhou University of Science and Technology, Suzhou 215009 (China); Ni, Chaoying [W.M.Keck Center for Advanced Microscopy and Microanalysis, University of Delaware, Newark, DE 19716 (United States)

    2016-02-28

    Graphical abstract: - Highlights: • Novel attapulgite(ATP)-CeO{sub 2}/MoS{sub 2} ternary nanocomposites were fabricated. • ATP possessed outstanding adsorption property and enhanced the stability of the network structure. • CeO{sub 2}/MoS{sub 2} couples facilitated the separation of photo-induced electrons and holes. • Mass ratio of CeO{sub 2}/MoS{sub 2} influenced the photocatalytic oxidation desulfurization. - Abstract: Novel attapulgite(ATP)-CeO{sub 2}/MoS{sub 2} ternary nanocomposites were synthesized by microwave assisted assembly method. The structures of the nanocomposites were characterized by XRD, FT-IR, UV–vis, XPS and in situ TEM. The photocatalytic activities of ATP-CeO{sub 2}/MoS{sub 2} composites were investigated by degradating dibenzothiophene (DBT) in gasoline under visible light irradiation. The effect of the mass ratio of CeO{sub 2} to MoS{sub 2} on photocatalytic activity was investigated. The results indicate that the three-dimensional network structure is firmly constructed by ATP skeleton, CeO{sub 2} particles and MoS{sub 2} nanosheet which effectively increase the surface area of the composites and promote the separation of electrons and holes by resulting electronic transmission channels of multi-channel in space. The degradation rate of DBT can reach 95% under 3 h irradiation when the mass ratio of CeO{sub 2}/MoS{sub 2} is 4/10. A plausible mechanism for the photocatalytic oxidative desulfurization of this nanocomposite is put forward.

  11. Efficient assessment of modified nucleoside stability under conditions of automated oligonucleotide synthesis: characterization of the oxidation and oxidative desulfurization of 2-thiouridine.

    Science.gov (United States)

    Sochacka, E

    2001-01-01

    In order to efficiently assess the chemical stability of modified nucleosides to the reagents and conditions of automated oligonucleotide synthesis, we designed, developed and tested a scheme in which the modified nucleoside, directly attached to a solid support, is exposed to the cyclic chemistry of the instrument. Stability of 2-thiouridine against different oxidizers was investigated. Tertbutyl hydroperoxide (1 M) in anhydrous acetonitrile was a more effective oxidizer for the incorporation of 2-thiouridine into oligonucleotide chains than the same oxidizer in methylene chloride. Carbon tetrachloride/water in the presence of a basic catalyst was superior in maintaining the thiocarbonyl function, but its utility for RNA synthesis has yet to be fully tested, whereas 2-phenylsulfonyloxaziridine was a very efficient reagent for oxidative desulfurization of 2-thiouridine.

  12. Optimization of Deep Oxidative Desulfurization Process Using Ionic Liquid and Potassium Monopersulfate

    Directory of Open Access Journals (Sweden)

    Yinke Zhang

    2018-01-01

    Full Text Available Response surface methodology (RSM was selected to optimize a desulfurization process with metal based ionic liquids ([Bmim]Cl/CoCl2 and potassium monopersulfate (PMS together to remove benzothiophene (BT from octane (simulating oil. The four experimental conditions of PMS dosage, [Bmim]Cl/CoCl2 dosage, temperature, and reaction time were investigated. The results showed that the quadratic relationship was built up between BT removal and four experimental variables with 0.9898 fitting coefficient. The optimal conditions were 1.6 g (20 wt% PMS solution, 3.2 g [Bmim]Cl/CoCl2, 46°C, and 23 min, which were obtained based on RSM and experimental results. Under the optimal condition, predicted sulfur removal rate and experimental sulfur removal rate were 96.7% and 95.4%, respectively. The sequence of four experimental conditions on desulfurization followed the order temperature > time > [Bmim]Cl/CoCl2 dosage > PMS solution dosage.

  13. Mechanistic studies of chemical looping desulfurization of Mn-based oxides using in situ X-ray absorption spectroscopy

    International Nuclear Information System (INIS)

    König, C.F.J.; Nachtegaal, M.; Seemann, M.; Clemens, F.; Garderen, N. van; Biollaz, S.M.A.; Schildhauer, T.J.

    2014-01-01

    Highlights: • Mn sorbents remove H 2 S from hot syngas in chemical looping desulfurization process. • State of Mn followed by in situ X-ray absorption spectroscopy and mass spectrometry. • Two-step mechanism explains the formation of SO 2 under reducing conditions. - Abstract: Cleaning of producer gas from biomass gasification is required for further processing, e.g. to avoid catalyst poisoning in subsequent conversion steps. High-temperature gas cleaning, of which sulfur removal is an important part, is a promising way to improve the overall efficiency of biomass conversion. In a high temperature “chemical looping desulfurization” process, a sorbent material, here manganese oxide, is cycled between producer gas from the gasifier to remove sulfur species, and an oxidizing atmosphere, in which the sulfur species are released as SO 2 . Alternatively, the use of such material as reactive bed material could be integrated into an allothermal dual fluidized bed gasifier. In a laboratory reactor, we subjected manganese-based materials to a periodically changing gas atmosphere, simulating a “chemical looping desulfurization” reactor. The “fuel reactor” gas contained H 2 , CO, CH 4 and H 2 S, similar as in the producer gas, and the “oxidizing reactor” contained diluted O 2 . Mass spectrometry showed that most of the H 2 S is taken up by the sample in the “fuel reactor” part, while also some unwanted SO 2 is generated in the “fuel reactor” part. Most of the sulfur is released in the oxidizing reactor. Simultaneous in situ X-ray absorption spectroscopy (XAS) of the Mn materials during different stages of the chemical looping desulfurization process showed that the initial Mn 3 O 4 is transformed in the presence of H 2 S to MnS via a MnO intermediate in the fuel reactor. Oxygen from the reduction of Mn 3 O 4 oxidizes some H 2 S to the undesired SO 2 in the fuel reactor. Upon exposure to O 2 , MnS is again oxidized to Mn 3 O 4 via MnO, releasing SO

  14. Characterization of copper oxides, iron oxides, and zinc copper ferrite desulfurization sorbents by X-ray photoelectron spectroscopy and scanning electron microscopy

    Science.gov (United States)

    Siriwardane, Ranjani V.; Poston, James A.

    1993-05-01

    Characterization of copper oxides, iron oxides, and zinc copper ferrite desulfurization sorbents was performed by X-ray photoelectron spectroscopy and scanning electron microscopy/energy-dispersive spectroscopy at temperatures of 298 to 823 K. Analysis of copper oxides indicated that the satellite structure of the Cu22p region was absent in the Cu(I) state but was present in the Cu(II) state. Reduction of CuO at room temperature was observed when the ion gauge was placed close to the sample. The satellite structure was absent in all the copper oxides at 823 K in vacuum. Differentiation of the oxidation state of copper utilizing both Cu(L 3M 4,5M 4,5) X-ray-induced Auger lines and Cu2p satellite structure, indicated that the copper in zinc copper ferrite was in the + 1 oxidation state at 823 K. This + 1 state of copper was not significantly changed after exposure to H 2, CO, and H 2O. There was an increase in Cu/Zn ratio and a decrease in Fe/Zn ratio on the surface of zinc copper ferrite at 823 K compared to that at room temperature. These conditions of copper offered the best sulfidation equilibrium for the zinc copper ferrite desulfurization sorbent. Analysis of iron oxides indicated that there was some reduction of both Fe 2O 3 and FeO at 823K. The iron in zinc copper ferrite was similar to that of Fe 2O 3 at room temperature but there was some reduction of this Fe(III) state to Fe(II) at 823 K. This reduction was more enhanced in the presence of H 2 and CO. Reduction to Fe(II) may not be desirable for the lifetime of the sorbent.

  15. Continuous-flow ultrasound assisted oxidative desulfurization (UAOD) process: An efficient diesel treatment by injection of the aqueous phase.

    Science.gov (United States)

    Rahimi, Masoud; Shahhosseini, Shahrokh; Movahedirad, Salman

    2017-11-01

    A new continuous-flow ultrasound assisted oxidative desulfurization (UAOD) process was developed in order to decrease energy and aqueous phase consumption. In this process the aqueous phase is injected below the horn tip leading to enhanced mixing of the phases. Diesel fuel as the oil phase with sulfur content of 1550ppmw and an appropriate mixture of hydrogen peroxide and formic acid as the aqueous phase were used. At the first step, the optimized condition for the sulfur removal has been obtained in the batch mode operation. Hence, the effect of more important oxidation parameters; oxidant-to-sulfur molar ratio, acid-to-sulfur molar ratio and sonication time were investigated. Then the optimized conditions were obtained using Response Surface Methodology (RSM) technique. Afterwards, some experiments corresponding to the best batch condition and also with objective of minimizing the residence time and aqueous phase to fuel volume ratio have been conducted in a newly designed double-compartment reactor with injection of the aqueous phase to evaluate the process in a continuous flow operation. In addition, the effect of nozzle diameter has been examined. Significant improvement on the sulfur removal was observed specially in lower sonication time in the case of dispersion method in comparison with the conventional contact between two phases. Ultimately, the flow pattern induced by ultrasonic device, and also injection of the aqueous phase were analyzed quantitatively and qualitatively by capturing the sequential images. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Synthesis of 2-azaindolizines by using an iodine-mediated oxidative desulfurization promoted cyclization of N-2-pyridylmethyl thioamides and an investigation of their photophysical properties.

    Science.gov (United States)

    Shibahara, Fumitoshi; Kitagawa, Asumi; Yamaguchi, Eiji; Murai, Toshiaki

    2006-11-23

    Iodine-mediated, oxidative desulfurization promoted cyclization of N-2-pyridylmethyl thioamides serves as an efficient and versatile method for the preparation of 2-azaindolizines (imidazo[1,5-a]pyridines) and rare 2-azaindolizine sulfur-bridged dimers. The 2-azaindolizines prepared in this manner are readily converted to a variety of fluorescent compounds by using transition-metal-catalyzed cross-coupling reactions. [reaction: see text].

  17. Enzymatic desulfurization of coal

    Energy Technology Data Exchange (ETDEWEB)

    Boyer, Y.N.; Crooker, S.C.; Kitchell, J.P.; Nochur, S.V.

    1991-05-16

    The overall objective of this program was to investigate the feasibility of an enzymatic desulfurization process specifically intended for organic sulfur removal from coal. Toward that end, a series of specific objectives were defined: (1) establish the feasibility of (bio)oxidative pretreatment followed by biochemical sulfate cleavage for representative sulfur-containing model compounds and coals using commercially-available enzymes; (2) investigate the potential for the isolation and selective use of enzyme preparations from coal-utilizing microbial systems for desulfurization of sulfur-containing model compounds and coals; and (3) develop a conceptual design and economic analysis of a process for enzymatic removal of organic sulfur from coal. Within the scope of this program, it was proposed to carry out a portion of each of these efforts concurrently. (VC)

  18. Oxidative Desulfurization of Dibenzothiophene Using Dawson Type Heteropoly Compounds/Tantalum as Catalyst

    Directory of Open Access Journals (Sweden)

    Risfidian Mohadi

    2016-03-01

    Full Text Available Catalyst (NH46[b-P2W18O62]/Ta has been synthesized by simple wet impregnation at 30-40 °C under atmospheric conditions using Dawson type polyoxometalate (NH46[b-P2W18O62] and tantalum. The catalyst was characterized by FTIR spectrophotometer, XRD, SEM, and N2 adsorption desorption methods. FTIR spectrum of (NH46[b-P2W18O62]/Ta showed that Dawson type polyoxometalate (NH46[b-P2W18O62] and Ta was successfully impregnated which was indicated by vibration spectrum at wavenumber of 900-1100 cm-1 for polyoxometalate and 550 cm-1 for Ta. The surface area of the (NH46[b-P2W18O62]/Ta after impregnation was higher than (NH46[b-P2W18O62]•nH2O and its morphology was found to be uniform. The catalytic activity of (NH46[b-P2W18O62]/Ta toward desulfurization of dibenzothiophene was three times higher than the original catalyst of (NH46[b-P2W18O62]•nH2O without impregnation. The catalytic regeneration test of catalyst (NH46[b-P2W18O62]/Ta showed that the catalytic activity for first regeneration of catalyst has similar catalytic activity with the fresh catalyst without loss of catalytic activity indicated by almost similar percent conversion.

  19. Deep Oxidative Desulfurization of Dibenzothiophene in Simulated Oil and Real Diesel Using Heteropolyanion-Substituted Hydrotalcite-Like Compounds as Catalysts

    OpenAIRE

    Yu, Fengli; Wang, Rui

    2013-01-01

    Three heteropolyanion substituted hydrotalcite-like compounds (HPA-HTLcs) including Mg9Al3(OH)24[PW12O40](MgAl-PW12), Mg9Al3(OH)24[PMo12O40] (MgAl-PMo12) and Mg12Al4(OH)32[SiW12O40] (MgAl-SiW12), were synthesized, characterized and used as catalysts for the oxidative desulfurization of simulated oil (dibenzothiophene, DBT, in n-octane). MgAl-PMo12 was identified as an effective catalyst for the oxidative removal of DBT under very mild conditions of atmospheric pressure and 60 °C in a biphasic...

  20. Desulfurization and oxidation behavior of ultra-fine CaO particles prepared from brown coal; Kattan wo mochiite choseishita CaO chobiryushi no datsuryu tokusei to sanka tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Benjamin, G.; Roman, M.; Yamazaki, Y.; Abe, H.; Harano, Y.; Takarada, Y. [Gunma University, Gunma (Japan). Faculty of Engineering

    1996-10-28

    The effect of reaction temperature and oxygen concentration on the desulfurization and oxidation behavior of ion-exchanged brown coal by Ca as new desulfurizing agent was studied. In experiment, Yallourn coal was used for ion- exchange, and limestone produced in Tochigi prefecture was also used for comparative study. Ca-exchanged brown coal was prepared by agitating coal in Ca(OH)2 slurry for 24 hours. The desulfurization behavior of a desulfurizing agent was obtained by measuring H2S and sulfur compounds in outlet gas of a reactor, and the oxidation behavior by measuring SO2 emission in outlet gas after oxidation reaction. As the experimental result, CaO produced from Ca-exchanged brown coal offered the extremely high activity to desulfurization reaction in a temperature range of 850-950{degree}C as compared with limestone. Although the oxidation behavior was dependent on oxidation temperature and oxygen concentration, CaS obtained from Ca-exchanged brown coal was more rapidly converted to CaSO4 than limestone. 3 refs., 8 figs., 2 tabs.

  1. The use of vacuum ultraviolet irradiation to oxidize SO2 and NOx for simultaneous desulfurization and denitrification

    International Nuclear Information System (INIS)

    Ye, Junhui; Shang, Jing; Li, Qian; Xu, Weiwei; Liu, Jia; Feng, Xiang; Zhu, Tong

    2014-01-01

    Highlights: • ROS, ·OH, ·HO 2 , ·O, and O 3 were generated by VUV photolysis of water and oxygen. • SO 2 and NO x can react with ROS to offer 90% and 96% removal efficiency, respectively. • The flue gas factors’ influences on SO 2 and NO x removal efficiency were investigated. • Mechanisms were proposed based on the photooxidation reactions and ROS generation. • The final products H 2 SO 4 and HNO 3 can be used as industrial raw materials. - Abstract: A simple and efficient method for simultaneous desulfurization and denitrification via vacuum ultraviolet (VUV) irradiation and with no additional chemicals is presented. The simultaneous removal of 90% SO 2 and 96% NO x (NO + NO 2 ) was achieved from the simulated flue gas under the irradiation from a low-pressure mercury lamp with main wavelengths of 185 and 254 nm, respectively. The composition, flow rate, and temperature of the simulated flue gas, as well as the VUV light intensity, were evaluated as the factors impacting on the efficiency of SO 2 and NO x removal. The ·OH, ·HO 2 , ·O, and O 3 produced from the photolysis of H 2 O and O 2 were concluded as the major reactive oxygen species that oxidized SO 2 and NO x . The additional ·OH and ·HO 2 generated through the reactions of NO + ·HO 2 and SO 2 + ·OH/·HO 2 improved treatment efficiency, while the oxidation products of NO x , e.g., NO 2 , HNO 2 , HNO 3 , and HNO 4 , consumed massive reactive oxygen species (such as ·O, ·OH, and ·HO 2 ) and thereby reducing the removal efficiencies. The main reaction products were characterized as H 2 SO 4 and HNO 3 by ion chromatography, which could be used as chemical or fertilizer raw materials

  2. Survey of oxide candidate for advanced 9%, 14% and 17%Cr ODS steels for fusion applications

    Czech Academy of Sciences Publication Activity Database

    Hadraba, Hynek; Husák, Roman; Stratil, Luděk; Šiška, Filip; Chlup, Zdeněk; Puchý, V.; Michalička, J.

    2017-01-01

    Roč. 124, NOV (2017), s. 1028-1032 ISSN 0920-3796 R&D Projects: GA ČR(CZ) GA14-25246S; GA ČR GJ15-21292Y Institutional support: RVO:68081723 Keywords : ODS steel * Mechanical alloying * SPS * Tensile behavior * Hardness Subject RIV: JG - Metallurgy OBOR OECD: Materials engineering Impact factor: 1.319, year: 2016

  3. Oxidative desulfurization of dibenzothiophene with hydrogen peroxide catalyzed by selenium(IV)-containing peroxotungstate.

    Science.gov (United States)

    Hu, Yiwen; He, Qihui; Zhang, Zheng; Ding, Naidong; Hu, Baixing

    2011-11-28

    With stoichiometric H(2)O(2) as oxidant, dibenzothiophene (DBT) is oxidized to its corresponding sulfone with high efficiency, catalyzed by a sub-valence heteronuclear peroxotungstate, [C(18)H(37)N(CH(3))(3)](4)[H(2)Se(IV)(3)W(6)O(34)], under mild biphase conditions and the catalyst shows remarkable selectivity of catalytic oxidation towards DBT, cinnamyl alcohol and quinoline.

  4. Ion implantation-induced defects in Oxide Dispersion Strengthened (ODS) steel probed by positron annihilation spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Anwand, Wolfgang; Butterling, Maik; Brauer, Gerhard; Wagner, Andreas [HZDR, Institut fuer Strahlenphysik (Germany); Richter, Astrid [Technische Hochschule Wildau (Germany); Koegler, Reinhard [HZDR, Institut fuer Ionenstrahlphysik und Materialforschung (Germany); Chen, C.L. [I-Shou University, Kaohsiung (China)

    2012-07-01

    ODS steel is a promising candidate for an application in fission and fusion power plants of a new generation because of its advantageous properties as stability and temperature resistance. A microscopic understanding of the physical reasons of the mechanical and thermal properties as well as the behaviour of the material under irradiation is an important pre-condition for such applications. The investigated ODS FeCrAl alloy *PM2000* has been produced in a powder metallurgical way. Neutron-induced damage at ODS steel was simulated by He{sup +} and Fe{sup 2+} co-implantation with energies of 2.5 MeV and 400 keV, respectively, and different fluences. The implantation has been carried out with a dual ion beam which enables a simultaneous implantation of both ion types. Thereby the Fe{sup 2+} implantation was used for the creation of radiation defects, and He{sup +} was implanted in order to reproduce He bubbles as they are expected to appear by neutron irradiation. The implantation-induced damage was investigated by depth dependent Doppler broadening measurements using a variable energy slow positron beam.

  5. Desulfurization of Jordanian oil shale

    International Nuclear Information System (INIS)

    Abu-Jdayil, B. M.

    1990-01-01

    Oxy desulfurization process and caustic treatment were applied in this work to remove sulfur from Jordanian oil shale. The oxy desulfurization process has been studied in a batch process using a high pressure autoclave, with constant stirring speed, and oxygen and water were used as desulfurizing reagents. Temperature, oxygen pressure, batch time, and particle size were found to be important process variables, while solid/liquid ratio was found to have no significant effect on the desulfurization process. The response of different types of oil shale to this process varied, and the effect of the process variables on the removal of total sulfur, pyritic sulfur, organic sulfur, total carbon, and organic carbon were studied. An optimum condition for oxy desulfurization of El-Lajjun oil shale, which gave maximum sulfur removal with low loss of carbon, was determined from the results of this work. The continuous reaction model was found to be valid, and the rate of oxidation for El-Lajjun oil shale was of the first order with respect to total sulfur, organic sulfur, total carbon, and organic carbon. For pyritic sulfur oxidation, the shrinking core model was found to hold and the rate of reaction controlled by diffusion through product ash layer. An activation energy of total sulfur, organic sulfur, pyritic sulfur, total carbon, and organic carbon oxidation was calculated for the temperature range of 130 -190 degrees celsius. In caustic treatment process, aqueous sodium hydroxide at 160 degrees celsius was used to remove the sulfur from El-Lajjun oil shale. The variables tested (sodium hydroxide concentration and treatment time) were found to have a significant effect. The carbon losses in this process were less than in the oxy desulfurization process. 51 refs., 64 figs., 121 tabs. (A.M.H.)

  6. Deep oxidative desulfurization of dibenzothiophene in simulated oil and real diesel using heteropolyanion-substituted hydrotalcite-like compounds as catalysts.

    Science.gov (United States)

    Yu, Fengli; Wang, Rui

    2013-11-05

    Three heteropolyanion substituted hydrotalcite-like compounds (HPA-HTLcs) including Mg₉Al₃(OH)₂₄[PW₁₂O₄₀](MgAl-PW₁₂), Mg₉Al₃(OH)₂₄[PMo₁₂O₄₀] (MgAl-PMo₁₂) and Mg₁₂Al₄(OH)₃₂[SiW₁₂O₄₀] (MgAl-SiW₁₂), were synthesized, characterized and used as catalysts for the oxidative desulfurization of simulated oil (dibenzothiophene, DBT, in n-octane). MgAl-PMo₁₂ was identified as an effective catalyst for the oxidative removal of DBT under very mild conditions of atmospheric pressure and 60 °C in a biphasic system using hydrogen peroxide as oxidant and acetonitrile as extractant. The conversion of DBT was nearly 100%. As a result, because of the influence of the electron density and the space steric hindrance, the oxidation reactivity of the different sulfur compounds in simulated oil followed the order DBT > 4,6-dimethyldibenzothiophene (4,6-DMDBT) > benzothiophene (BT) > thiophene (TH). When the reaction is finished, the catalysts can be recovered from the acetonitrile phase by filtration. The recovered MgAl-PMo₁₂ retains nearly the same catalytic activity as the fresh material. Moreover, MgAl-PMo₁₂ was found to exhibit an ideal catalytic activity in the oxidative desulfurization of real diesel resulting in a total remaining sulfur content of 9.12 ppm(w).

  7. Deep Oxidative Desulfurization of Dibenzothiophene in Simulated Oil and Real Diesel Using Heteropolyanion-Substituted Hydrotalcite-Like Compounds as Catalysts

    Directory of Open Access Journals (Sweden)

    Rui Wang

    2013-11-01

    Full Text Available Three heteropolyanion substituted hydrotalcite-like compounds (HPA-HTLcs including Mg9Al3(OH24[PW12O40](MgAl-PW12, Mg9Al3(OH24[PMo12O40] (MgAl-PMo12 and Mg12Al4(OH32[SiW12O40] (MgAl-SiW12, were synthesized, characterized and used as catalysts for the oxidative desulfurization of simulated oil (dibenzothiophene, DBT, in n-octane. MgAl-PMo12 was identified as an effective catalyst for the oxidative removal of DBT under very mild conditions of atmospheric pressure and 60 °C in a biphasic system using hydrogen peroxide as oxidant and acetonitrile as extractant. The conversion of DBT was nearly 100%. As a result, because of the influence of the electron density and the space steric hindrance, the oxidation reactivity of the different sulfur compounds in simulated oil followed the order DBT > 4,6-dimethyldibenzothiophene (4,6-DMDBT > benzothiophene (BT > thiophene (TH. When the reaction is finished, the catalysts can be recovered from the acetonitrile phase by filtration. The recovered MgAl-PMo12 retains nearly the same catalytic activity as the fresh material. Moreover, MgAl-PMo12 was found to exhibit an ideal catalytic activity in the oxidative desulfurization of real diesel resulting in a total remaining sulfur content of 9.12 ppm(w.

  8. Deep desulfurization by amphiphilic lanthanide-containing polyoxometalates in ionic-liquid emulsion systems under mild conditions.

    Science.gov (United States)

    Xu, Junhua; Zhao, Shen; Ji, Yuanchun; Song, Yu-Fei

    2013-01-07

    Amphiphilic lanthanide-containing polyoxometalates (POMs) were prepared by surfactant encapsulation. Investigation of these lanthanide-containing POMs in oxidative desulfurization (ODS) showed that highly efficient deep desulfurization could be achieved in only 14 min with 100% conversion of dibenzothiophene under mild conditions by using (DDA)(9)LaW(10)/[omim]PF(6) (DDA=dimethyldioctadecylammonium, omim=1-octyl-3-methyl-imidazolium) in the presence of H(2) O(2) . Furthermore, deep desulfurization proceeds smoothly in model oil with an S content as low as 50 ppm. A scaled-up experiment in which the volume of model oil was increased from 5 to 1000 mL with S content of 1000 ppm indicated that about 99% sulfur removal can be achieved in 40 mins in an ionic-liquid emulsion system. To the best of our knowledge, the (DDA)(9)LaW(10)/[omim]PF(6) catalyst system with H(2)O(2) as oxidant is one of the most efficient desulfurization systems reported so far. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. ABB wet flue gas desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Niijhawan, P.

    1994-12-31

    The wet limestone process for flue gas desulfurization (FGD) is outlined. The following topics are discussed: wet flue gas desulfurization, wet FGD characteristics, wet scrubbers, ABB wet FGD experience, wet FGD forced oxidation, advanced limestone FGD systems, key design elements, open spray tower design, spray tower vs. packed tower, important performance parameters, SO{sub 2} removal efficiency, influence by L/G, limestone utilization, wet FGD commercial database, particulate removal efficiencies, materials of construction, nozzle layout, spray nozzles, recycle pumps, mist elimination, horizontal flow demister, mist eliminator washing, reagent preparation system, spray tower FGDS power consumption, flue gas reheat options, byproduct conditioning system, and wet limestone system.

  10. Investigation of Influential Parameters in Deep Oxidative Desulfurization of Dibenzothiophene with Hydrogen Peroxide and Formic Acid

    OpenAIRE

    Haghighat Mamaghani, Alireza; Fatemi, Shohreh; Asgari, Mehrdad

    2013-01-01

    An effective oxidative system consisting of hydrogen peroxide, formic acid, and sulfuric acid followed by an extractive stage were implemented to remove dibenzothiophene in the simulated fuel oil. The results revealed such a great performance in the case of H2O2 in the presence of formic and sulfuric acids that led to the removal of sulfur compounds. Sulfuric acid was employed to increase the acidity of media as well as catalytic activity together with formic acid. The oxidation reaction was ...

  11. Synthesis of mesoporous TS-1 using a hybrid SiO{sub 2}–TiO{sub 2} xerogel for catalytic oxidative desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Seung-Tae [Department of Chemical Engineering, Inha University, Incheon 402-751 (Korea, Republic of); Jeong, Kwang-Eun; Jeong, Soon-Yong [Research Center for Green Catalysis, Division of Green Chemistry and Engineering Research, Korea Research Institute of Chemical Technology, P.O. Box 107, 141 Gajeong-ro, Yuseong, Daejeon 305-600 (Korea, Republic of); Ahn, Wha-Seung, E-mail: whasahn@inha.ac.kr [Department of Chemical Engineering, Inha University, Incheon 402-751 (Korea, Republic of)

    2012-12-15

    Graphical abstract: Display Omitted Highlights: ► Meso-TS-1 catalyst was synthesized using a SiO{sub 2}–TiO{sub 2} xerogel with an organosilane precursor. ► Hierarchical pore structure was confirmed by characterization of the materials. ► Catalytic activity was tested using oxidative desulfurization of the model sulfur compounds. ► Meso-TS-1 demonstrated significantly improved catalytic activity than TS-1. -- Abstract: Mesoporous TS-1 (M-TS-1) was synthesized using a hybrid SiO{sub 2}–TiO{sub 2} xerogel combined with an organosilane precursor. Prepared samples were characterized by XRD, UV–vis spectroscopy, SEM, and N{sub 2} adsorption–desorption measurement. M-TS-1, prepared in 2 days, showed high crystallinity and the best textural properties among the samples. The N{sub 2} adsorption–desorption isotherms of M-TS-1 exhibited a hysteresis loop at pressure higher than P/P{sub 0} = 0.4, clearly indicating the existence of mesopores. M-TS-1 has significantly larger mesopore volume (0.48 cm{sup 3}/g) than that of conventional TS-1 (0.07 cm{sup 3}/g), and showed a narrow peak centered at ca. 6.3 nm. In the oxidative desulfurization reaction, M-TS-1 was more active than conventional TS-1 at the same Ti-loading; M-TS-1 produced a dibenzothiophene (DBT) conversion of 96%, whereas conventional TS-1 produced a final DBT conversion of 5.6% after a reaction time of 180 min. Oxidative desulfurization over TS-1 was influenced both by electron density and steric hindrance in the sulfur compounds tested.

  12. Synthesis of mesoporous TS-1 using a hybrid SiO2–TiO2 xerogel for catalytic oxidative desulfurization

    International Nuclear Information System (INIS)

    Yang, Seung-Tae; Jeong, Kwang-Eun; Jeong, Soon-Yong; Ahn, Wha-Seung

    2012-01-01

    Graphical abstract: Display Omitted Highlights: ► Meso-TS-1 catalyst was synthesized using a SiO 2 –TiO 2 xerogel with an organosilane precursor. ► Hierarchical pore structure was confirmed by characterization of the materials. ► Catalytic activity was tested using oxidative desulfurization of the model sulfur compounds. ► Meso-TS-1 demonstrated significantly improved catalytic activity than TS-1. -- Abstract: Mesoporous TS-1 (M-TS-1) was synthesized using a hybrid SiO 2 –TiO 2 xerogel combined with an organosilane precursor. Prepared samples were characterized by XRD, UV–vis spectroscopy, SEM, and N 2 adsorption–desorption measurement. M-TS-1, prepared in 2 days, showed high crystallinity and the best textural properties among the samples. The N 2 adsorption–desorption isotherms of M-TS-1 exhibited a hysteresis loop at pressure higher than P/P 0 = 0.4, clearly indicating the existence of mesopores. M-TS-1 has significantly larger mesopore volume (0.48 cm 3 /g) than that of conventional TS-1 (0.07 cm 3 /g), and showed a narrow peak centered at ca. 6.3 nm. In the oxidative desulfurization reaction, M-TS-1 was more active than conventional TS-1 at the same Ti-loading; M-TS-1 produced a dibenzothiophene (DBT) conversion of 96%, whereas conventional TS-1 produced a final DBT conversion of 5.6% after a reaction time of 180 min. Oxidative desulfurization over TS-1 was influenced both by electron density and steric hindrance in the sulfur compounds tested.

  13. ODS iron aluminides

    Energy Technology Data Exchange (ETDEWEB)

    Wright, I.G.; Pint, B.A.; Ohriner, E.K.; Tortorelli, P.F. [Oak Ridge National Lab., TN (United States)

    1996-08-01

    The overall goal of this program is to develop an oxide dispersion-strengthened (ODS) version of Fe{sub 3}Al that has sufficient creep strength and resistance to oxidation at temperatures in the range 1000 to 1200{degrees}C to be suitable for application as heat exchanger tubing in advanced power generation cycles. The program has two main thrusts: (a) alloy processing, which involves mechanical alloying and thermomechanical processing to achieve the desired size and distribution of the oxide dispersoid, and (b) optimization of the oxidation behavior to provide increased service life compared to ODS-FeCrAl alloys intended for the same applications. Control of the grain size and shape in the final alloy is very dependent on the homogeneity of the alloy powder, in terms of the size and distribution of the dispersed oxide particles, and on the level of strain and temperature applied in the recrystallization step. Studies of the effects of these variables are being made using mechanically-alloyed powder from two sources: a commercial powder metallurgy alloy vendor and an in-house, controlled environment high-energy mill. The effects of milling parameters on the microstructure and composition of the powder and consolidated alloy are described. Comparison of the oxidation kinetics of ODS-Fe{sub 3}Al alloys with commercial ODS-FeCrAl alloys in air at 1000-1300{degrees}C indicated that the best Fe{sub 3}Al-based alloys oxidized isothermally at the same rate as the ODS-FeCrAl alloys but, under thermal cycling conditions, the oxidation rate of ODS-Fe{sub 3}Al was faster. The main difference was that the ODS-Fe{sub 3}Al experienced significantly more scale spallation above 1000{degrees}C. The differences in oxidation behavior were translated into expected lifetimes which indicated that, for an alloy section thickness of 2.5 mm, the scale spallation of ODS-Fe{sub 3}Al leads to an expected service lifetime similar to that for the INCO alloy MA956 at 1100 to 1300{degrees}C.

  14. Short Communication on “Coarsening of Y-rich oxide particles in 9%Cr-ODS Eurofer steel annealed at 1350 °C”

    Energy Technology Data Exchange (ETDEWEB)

    Sandim, M.J.R.; Souza Filho, I.R.; Bredda, E.H. [Lorena School of Engineering, University of Sao Paulo, 12602-810, Lorena (Brazil); Kostka, A.; Raabe, D. [Max-Planck-Institut für Eisenforschung, D-40237, Düsseldorf (Germany); Sandim, H.R.Z., E-mail: hsandim@demar.eel.usp.br [Lorena School of Engineering, University of Sao Paulo, 12602-810, Lorena (Brazil)

    2017-02-15

    Oxide-dispersion strengthened (ODS) Eurofer steel is targeted for structural applications in future fusion nuclear reactors. Samples were cold rolled down to 80% reduction in thickness and annealed at 1350 °C up to 8 h. The microstructural characterization was performed using Vickers microhardness testing, electron backscatter diffraction, scanning and scanning transmission electron microscopies. Experimental results provide evidence of coarsening of the Y-rich oxide particles in ODS-Eurofer steel annealed at 1350 °C within delta ferrite phase field.

  15. Influence of scandium addition on the high-temperature grain size stabilization of oxide-dispersion-strengthened (ODS) ferritic alloy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lulu, E-mail: lli18@ncsu.edu; Xu, Weizong; Saber, Mostafa; Zhu, Yuntian; Koch, Carl C.; Scattergood, Ronald O.

    2015-06-11

    The influence of 1–4 at% Sc addition on the thermal stability of mechanically alloyed ODS ferritic alloy was studied in this work. Sc addition was found to significantly stabilize grain size and microhardness at high temperatures. Grain sizes of samples with 1 and 4 at% Sc was found maintained in the nanoscale range at temperatures up to 1000 °C with hardness maintained at 5.6 and 6.7 GPa, respectively. The detailed microstructure was also investigated from EDS elemental mapping, where nanofeatures [ScTiO] were observed, while nanosized [YTiO] particles were rarely seen. This is probably due to the concentration difference between Sc and Y, leading to the formation of [ScTiO] favoring that of [YTiO]. Precipitation was considered as the major source for the observed high temperature stabilization. In addition, 14YT–Sc alloys without large second phases such as Ti-oxide can exhibit better performance compared to conventional ODS materials.

  16. Silver nanocrystal-decorated polyoxometalate single-walled nanotubes as nanoreactors for desulfurization catalysis at room temperature.

    Science.gov (United States)

    Zhang, Hao; Xu, Xiaobin; Lin, Haifeng; Ud Din, Muhammad Aizaz; Wang, Haiqing; Wang, Xun

    2017-09-14

    Ultrathin nanocrystals generally provide a remarkable catalytic performance due to their high specific surface area and exposure of certain active sites. However, deactivation caused by growth and gathering limits the catalytic application of ultrathin nanocrystals. Here we report Ag nanocrystal-decorated polyoxometalate (Ag-POM) single-walled nanotubes assembled via a concise, surfactant-free soaking method as a new kind of well-defined core-sheath nanoreactor. The diameter of Ag nanocrystals inside polyoxometalate nanotubes can be controlled via simply adjusting the reactant concentration. Ag-POM provided outstanding oxidative desulfurization (ODS) catalytic performance for aromatic sulfocompounds at room temperature. It was suggested that Ag nanocrystals decorated on the inner surface played a key role in adjusting the electronic distribution and enhancing the catalytic activity. The as-prepared Ag-POM nanotubes are promising candidate catalysts with enhanced performance for practical catalytic applications in the gasoline desulfurization industry.

  17. Investigation of Influential Parameters in Deep Oxidative Desulfurization of Dibenzothiophene with Hydrogen Peroxide and Formic Acid

    Directory of Open Access Journals (Sweden)

    Alireza Haghighat Mamaghani

    2013-01-01

    Full Text Available An effective oxidative system consisting of hydrogen peroxide, formic acid, and sulfuric acid followed by an extractive stage were implemented to remove dibenzothiophene in the simulated fuel oil. The results revealed such a great performance in the case of H2O2 in the presence of formic and sulfuric acids that led to the removal of sulfur compounds. Sulfuric acid was employed to increase the acidity of media as well as catalytic activity together with formic acid. The oxidation reaction was followed by a liquid-liquid extraction stage using acetonitrile as a polar solvent to remove produced sulfones from the model fuel. The impact of operating parameters including the molar ratio of formic acid to sulfur (, hydrogen peroxide to sulfur (, and the time of reaction was investigated using Box-Behnken experimental design for oxidation of the model fuel. A significant quadratic model was introduced for the sulfur removal as a function of effective parameters by the statistic analysis.

  18. Effect of astaxanthin in combination with alpha-tocopherol or ascorbic acid against oxidative damage in diabetic ODS rats.

    Science.gov (United States)

    Nakano, Masako; Onodera, Aya; Saito, Emi; Tanabe, Miyako; Yajima, Kazue; Takahashi, Jiro; Nguyen, Van Chuyen

    2008-08-01

    The present study was performed to investigate the effect of astaxanthin in combination with other antioxidants against oxidative damage in streptozotocin (STZ)-induced diabetic Osteogenic Disorder Shionogi (ODS) rats. Diabetic-ODS rats were divided into five groups: control, astaxanthin, ascorbic acid, alpha-tocopherol, and tocotrienol. Each of the four experimental groups was administered a diet containing astaxanthin (0.1 g/kg), in combination with ascorbic acid (3.0 g/kg), alpha-tocopherol (0.1 g/kg), or tocotrienol (0.1 g/kg) for 20 wk. The effects of astaxanthin with other antioxidants on lipid peroxidation, urinary 8-hydroxy-2-deoxyguanosine (8-OHdG) excretion, serum creatinine (Cr) level, creatinine clearance (Ccr), and urinary protein content were assessed. The serum lipid peroxide levels and chemiluminescent (CL) intensity in the liver of the alpha-tocopherol and tocotrienol groups were significantly reduced in comparison to that of the control group. In the alpha-tocopherol group, urinary 8-OHdG excretion, serum Cr level, Ccr, urinary albumin excretion, and urinary protein concentration were significantly decreased as compared with those in the control group. Additionally, the CL intensity in the kidney of the alpha-tocopherol group was significantly lower, but that of the ascorbic acid group was significantly higher than that in the control group. These results indicate that dietary astaxanthin in combination with alpha-tocopherol has an inhibitory effect on oxidative stress. On the other hand, our study suggests that excessive ascorbic acid intake increases lipid peroxidation in diabetic rats.

  19. Friction stir welding and processing of oxide dispersion strengthened (ODS) alloys

    Science.gov (United States)

    Ren, Weiju

    2014-11-11

    A method of welding including forming a filler material of a first oxide dispersoid metal, the first oxide dispersoid material having first strengthening particles that compensate for decreases in weld strength of friction stir welded oxide dispersoid metals; positioning the filler material between a first metal structure and a second metal structure each being comprised of at least a second oxide dispersoid metal; and friction welding the filler material, the first metal structure and the second metal structure to provide a weld.

  20. Nano-oxide nucleation in a 14Cr-ODS steel elaborated by reactive-inspired ball-milling: Multiscale characterizations

    International Nuclear Information System (INIS)

    Brocq, M.; Legendre, F.; Sakasegawa, H.; Radiguet, B.; Cuvilly, F.; Pareige, P.; Mathon, M.H.

    2009-01-01

    Oxide dispersion strengthened (ODS) steels are promising structural materials for both fusion and fission Generation IV reactors. Indeed, they exhibit excellent mechanical and creep properties and radiation resistance thanks to a fine and dense dispersion of complex nanometric oxides. ODS steels are usually elaborated by ball-milling iron based and yttrium oxide powders and then by thermomechanical treatments. It is expected that ball-milling dissolves yttrium oxides in the metallic matrix and that annealing induces nano-oxide precipitation. However the formation mechanism remains unclear and as a consequence the process is still uncontrolled. In this context, we proposed a new approach based on reactive ball milling of iron oxide (Fe 2 O 3 ), yttria (YFe 3 ) and iron based alloy in a dedicated instrumented ball-milling device. Also, a fine scale characterization, after each step of the process including ball-milling, is performed. A Fe-14Cr-2W-1Ti-0.8Y-0.2O (%wt) ODS steel was synthesized by reactive ball-milling and was characterized at very fine scale in both as-milled and as-annealed state. Atom Probe Tomography (APT) and Small Angle Neutron Scattering (SANS) were combined. After ballmilling, most of Y and O were, as expected, in solution in the ferritic matrix but some complex Y-Ti nano-oxides were also observed, indicating that oxide nucleation can start during ball-milling. With annealing the number of nano-oxides increases. In this presentation, experimental results of APT and SANS will be detailed and compared with what is usually observed in ODS steels elaborated by conventional ball milling. Finally, a formation mechanism of nano-oxides deduced from these results will be proposed. (author)

  1. Manufacturing test of large scale hollow capsule and long length cladding in the large scale oxide dispersion strengthened (ODS) martensitic steel

    International Nuclear Information System (INIS)

    Narita, Takeshi; Ukai, Shigeharu; Kaito, Takeji; Ohtsuka, Satoshi; Fujiwara, Masayuki

    2004-04-01

    Mass production capability of oxide dispersion strengthened (ODS) martensitic steel cladding (9Cr) has being evaluated in the Phase II of the Feasibility Studies on Commercialized Fast Reactor Cycle System. The cost for manufacturing mother tube (raw materials powder production, mechanical alloying (MA) by ball mill, canning, hot extrusion, and machining) is a dominant factor in the total cost for manufacturing ODS ferritic steel cladding. In this study, the large-sale 9Cr-ODS martensitic steel mother tube which is made with a large-scale hollow capsule, and long length claddings were manufactured, and the applicability of these processes was evaluated. Following results were obtained in this study. (1) Manufacturing the large scale mother tube in the dimension of 32 mm OD, 21 mm ID, and 2 m length has been successfully carried out using large scale hollow capsule. This mother tube has a high degree of accuracy in size. (2) The chemical composition and the micro structure of the manufactured mother tube are similar to the existing mother tube manufactured by a small scale can. And the remarkable difference between the bottom and top sides in the manufactured mother tube has not been observed. (3) The long length cladding has been successfully manufactured from the large scale mother tube which was made using a large scale hollow capsule. (4) For reducing the manufacturing cost of the ODS steel claddings, manufacturing process of the mother tubes using a large scale hollow capsules is promising. (author)

  2. TiO2-Containing Carbon Derived from a Metal-Organic Framework Composite: A Highly Active Catalyst for Oxidative Desulfurization.

    Science.gov (United States)

    Bhadra, Biswa Nath; Song, Ji Yoon; Khan, Nazmul Abedin; Jhung, Sung Hwa

    2017-09-13

    A new metal-organic framework (MOF) composite consisting of Ti- and Zn-based MOFs (ZIF-8(x)@H 2 N-MIL-125; in brief, ZIF(x)@MOF) was designed and synthesized. The pristine MOF [H 2 N-MIL-125 (MOF)]- and an MOF-composite [ZIF(30)@MOF]-derived mesoporous carbons consisting of TiO 2 nanoparticles were prepared by pyrolysis (named MDC-P and MDC-C, respectively). MDC-C showed a higher surface area, larger pore sizes, and larger mesopore volumes than MDC-P. In addition, the TiO 2 nanoparticles on MDC-C have more uniform shapes and sizes and are smaller than those of MDC-P. The obtained MDC-C and MDC-P [together with MOF, ZIF(30)@MOF, pure/nanocrystalline TiO 2 , and activated carbon] were applied in the oxidative desulfurization reaction of dibenzothiophene in a model fuel. The MDC-C, even with a lower TiO 2 content than that of MDC-P, showed an outstanding catalytic performance, especially with a very low catalyst dose (i.e., a very high quantity of dibenzothiophene was converted per unit weight of the catalyst), fast kinetics (∼3 times faster than that for MDC-P), and a low activation energy (lower than that for any reported catalyst) for the oxidation of dibenzothiophene. The large mesopores of MDC-C and the well-dispersed/small TiO 2 might be the dominant factors for the superior catalytic conversions. The oxidative desulfurization of other sulfur-containing organic compounds with various electron densities was also studied with MDC-C to understand the mechanism of catalysis. Moreover, the MDC-C catalyst can be reused many times in the oxidative desulfurization reaction after a simple washing with acetone. Finally, composing MOFs and subsequent pyrolysis is suggested as an effective way to prepare a catalyst with well-dispersed active sites, large pores, and high mesoporosity.

  3. The effects of dissolved organic matter and feeding on bioconcentration and oxidative stress of ethylhexyl dimethyl p-aminobenzoate (OD-PABA) to crucian carp (Carassius auratus).

    Science.gov (United States)

    Ma, Binni; Lu, Guanghua; Yang, Haohan; Liu, Jianchao; Yan, Zhenhua; Nkoom, Matthew

    2018-03-01

    Bioconcentration of UV filters in organisms is an important indicator for the assessment of environmental hazards. However, bioconcentration testing rarely accounts for the influence of natural aquatic environmental factors. In order to better assess the ecological risk of organic UV filters (OUV-Fs) in an actual water environment, this study determined the influences of dissolved organic matter (DOM) (0, 1, 10, and 20 mg/L) and feeding (0, 0.5, 1, and 2% body weight/d) on bioconcentration of ethylhexyl dimethyl p-aminobenzoate (OD-PABA) in various tissues of crucian carp (Carassius auratus). Moreover, oxidative stress in the fish liver caused by the OD-PABA was also investigated by measuring activities of superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST), and levels of glutathione (GSH) and malondialdehyde (MDA). The bioconcentration of OD-PABA in the fish tissues was significantly decreased with the presence of DOM indicating a reduction of OD-PABA bioavailability caused by DOM. The bioconcentration factors (BCFs) decreased by 28.00~50.93% in the muscle, 72.67~96.74% in the gill, 37.84~87.72% in the liver, and 10.32~79.38% in the kidney at different DOM concentrations compared to those of the non-DOM treatments. Significant changes in SOD, CAT, GST, GSH, and MDA levels were found in the DOM- and OD-PABA-alone treatments. However, there were no significant differences in the SOD, CAT, GST, and MDA levels found when co-exposure to OD-PABA and DOM. Feeding led to lower OD-PABA concentrations in the fish tissues, and the concentrations were decreased with increasing feeding ratios. BCFs in various tissues reduced by 39.75~72.52% in the muscle, 56.86~79.73% in the gill, 66.41~87.50% in the liver, and 75.88~89.10% in the kidney, respectively. In the unfed treatments, the levels of SOD and MDA were significantly higher than those of the fed ones while GST and GSH levels were remarkably inhibited indicating the enhanced effect of starvation

  4. The Biocatalytic Desulfurization Project

    Energy Technology Data Exchange (ETDEWEB)

    David Nunn; James Boltz; Philip M. DiGrazia; Larry Nace

    2006-03-03

    The material in this report summarizes the Diversa technical effort in development of a biocatalyst for the biodesulfurization of Petro Star diesel as well as an economic report of standalone and combined desulfurization options, prepared by Pelorus and Anvil, to support and inform the development of a commercially viable process. We will discuss goals of the projected as originally stated and their modification as guided by parallel efforts to evaluate commercialization economics and process parameters. We describe efforts to identify novel genes and hosts for the generation of an optimal biocatalyst, analysis of diesel fuels (untreated, chemically oxidized and hydrotreated) for organosulfur compound composition and directed evolution of enzymes central to the biodesulfurization pathway to optimize properties important for their use in a biocatalyst. Finally we will summarize the challenges and issues that are central to successful development of a viable biodesulfurization process.

  5. Chemically produced nanostructured ODS-lanthanum oxide-tungsten composites sintered by spark plasma

    International Nuclear Information System (INIS)

    Yar, Mazher Ahmed; Wahlberg, Sverker; Bergqvist, Hans; Salem, Hanadi G.; Johnsson, Mats; Muhammed, Mamoun

    2011-01-01

    High purity W and W-0.9La 2 O 3 (wt.%) nanopowders were produced by a wet chemical route. The precursor was prepared by the reaction of ammonium paratungstate (APT) with lanthanum salt in aqueous solutions. High resolution electron microscopy investigations revealed that the tungstate particles were coated with oxide precipitates. The precursor powder was reduced to tungsten metal with dispersed lanthanum oxide. Powders were consolidated by spark plasma sintering (SPS) at 1300 and 1400 o C to suppress grain growth during sintering. The final grain size relates to the SPS conditions, i.e. temperature and heating rate, regardless of the starting powder particle size. Scanning electron microscopy revealed that oxide phases were mainly accumulated at grain boundaries while the tungsten matrix constituted of nanosized sub-grains. The transmission electron microscopy revealed that the tungsten grains consist of micron-scale grains and finer sub-grains. EDX analysis confirmed the presence of W in dispersed oxide phases with varying chemical composition, which evidenced the presence of complex oxide phases (W-O-La) in the sintered metals.

  6. TEM study of internal oxidation in an ODS-Eurofer alloy

    International Nuclear Information System (INIS)

    Klimenkov, M.; Lindau, R.; Moeslang, A.

    2009-01-01

    Analytical TEM investigations of samples from an oxide dispersion-strengthened Eurofer batch show the formation of new type of precipitates of Fe-Cr-V-O composition and a size of 40-250 nm. Structural HRTEM analysis reveals that the precipitates consist of (Mn,Fe)(Cr,V) 2 O 4 manganese chromium oxide of spinel structure. In some cases, the inclusions order along lines that can reach more than ten micrometers in length. Such lines of large particles might have a negative influence on the mechanical properties of the steel, as was observed. It is assumed that they form by internal oxidation during hot isostatic pressing due to the high oxygen content of the mechanically alloyed powder.

  7. Investigations of oxide particles in unirradiated ODS-Eurofer by TEM and 3D atom probe methods

    International Nuclear Information System (INIS)

    Aleev, A.A.; Iskandarov, N.A.; Nikitin, A.A.; Rogizhkin, S.V.; Zaluzhny, A.G.; Klimenkov, M.; Lindau, R.; Moeslang, A.; Vladimirov, P.

    2009-01-01

    Oxide dispersion strengthened steels possess better high-temperature creep and radiation resistance than conventionally produced ferritic/martensitic steels. This behavior is mainly caused by the presence of highly dispersed and extremely stable oxide particles with sizes of few nanometers. One of the promising oxides used for dispersion strengthening was yttria (Y 2 O 3 ), which was introduced into EUROFER by mechanical alloying followed by the hot isostatic pressing at temperature around 1000-1200 dg. C and pressure ∼100 MPa. It was found that mechanical properties were strongly depended on size and spatial distribution of the precipitates. Therefore considerable efforts are focused on the investigation of the chemical composition and orientation of precipitates with respect to the steel matrix. Recent studies of Eurofer ODS steel (9%-CrWVTa) by SANS revealed the presence of high number density structural features with a size of approximately one nanometer. At the same time, previous studies by TEM identified only high number of small (6-40 nm) Y 2 O 3 particles. In this work we tried to get a deeper inside into the nanostructure of this material by means of tomographic atom probe and to correlate the results with the picture obtained by TEM. The present investigations revealed fine (∼2 nm) enrichments containing not only yttrium and oxygen but also vanadium and nitrogen. Concentration of vanadium was found to be approximately at the same level as yttrium. Some of the enrichments contained only three or even two elements mentioned above. Estimated number density of enrichments is about (1/5) x 10 23 m -3 . We suppose that these enriched zones might be precursors of the larger precipitates observed by TEM. The thesis seems to be supported by the similarities of the chemical composition and spatial distribution of elements inside enriched zones and nano precipitates studied by atomic probe and analytical TEM methods. (author)

  8. Radiation methods for demercaptanization and desulfurization of oil products

    International Nuclear Information System (INIS)

    Zaykina, R.F.; Zaykin, Yu.A.; Mamonova, T.B.; Nadirov, N.K.

    2002-01-01

    A two-stage method for the desulfurization of oil is presented. The first stage strongly oxidizes sulfuric material to do away with its chemical aggressiveness and promote its removal. Desulfurization of the overall product is reached at the second stage by means of conventional methods

  9. Radiation methods for demercaptanization and desulfurization of oil products

    Science.gov (United States)

    Zaykina, R. F.; Zaykin, Yu. A.; Mamonova, T. B.; Nadirov, N. K.

    2002-03-01

    A two-stage method for the desulfurization of oil is presented. The first stage strongly oxidizes sulfuric material to do away with its chemical aggressiveness and promote its removal. Desulfurization of the overall product is reached at the second stage by means of conventional methods.

  10. Statistical analysis of oxides particles in ODS ferritic steel using advanced electron microscopy

    International Nuclear Information System (INIS)

    Unifantowicz, P.; Schäublin, R.; Hébert, C.; Płociński, T.; Lucas, G.; Baluc, N.

    2012-01-01

    In this work a combination of advanced transmission electron microscopy and spectroscopy techniques enabled a statistically significant analysis of various types of few nanometer size oxides particles in Fe–14Cr–2W–0.3Ti–0.3Y 2 O 3 ferritic steel. These methods include a scanning TEM with EDS and EFTEM coupled with EELS. In addition, principal component analysis was applied to the chemical maps obtained by EFTEM, which drastically improved the signal to noise ratio. Three types of particles were identified in a size range from 2 to 300 nm, namely Cr–Ti–O, Y–O and Y–Ti–O particles, with an average size of 33,16 and 8 nm, respectively. The Cr–Ti–O particles contain Y and Ti enriched zones, which were not observed previously. The EFTEM analysis showed that the titanium addition leads to formation of Y–Ti–O nano-particles, which constitute 84% of the oxides but also precipitation of larger Cr–Ti–O. The presence of small amount of Y–O particles indicated a not sufficient amount of Ti available for reaction during mechanical alloying or consolidation.

  11. Synthesis of geminal difluorides by oxidative desulfurization-difluorination of alkyl aryl thioethers with halonium electrophiles in the presence of fluorinating reagents and its application for 18F-radiolabeling.

    Science.gov (United States)

    Hugenberg, Verena; Wagner, Stefan; Kopka, Klaus; Schober, Otmar; Schäfers, Michael; Haufe, Günter

    2010-09-17

    Various ω-substituted 1,1-difluoroalkanes are synthesized in good yields from alkyl aryl thioethers by a new oxidative desulfurization-difluorination protocol with the reagents combination of 1,3-dibromo-5,5-dimethylhydantoin (DBH) as an oxidizer and pyridine·9HF (Py·9HF) as a fluoride source. The reaction proceeds via a fluoro-Pummerer-type rearrangement followed by an oxidative desulfurization-fluorination step. Starting from α-fluorinated thioethers, this reaction is promising for (18)F-labeling (τ(1/2) = 110 min) of ligands applicable for positron emission tomography (PET). Using the combination of DBH and carrier-added Py·9H[(18)F]F, an (18)F-labeled difluoride was synthesized from the corresponding α-fluoro thioether with a radiochemical yield of 9%.

  12. HRTEM Study of Oxide Nanoparticles in 16Cr-4Al-2W-0.3Ti-0.3Y2O3 ODS Steel

    Energy Technology Data Exchange (ETDEWEB)

    Hsiung, L; Fluss, M; Wall, M; Kimura, A

    2009-11-18

    Crystal and interfacial structures of oxide nanoparticles in 16Cr-4Al-2W-0.3Ti-0.3Y{sub 2}O{sub 3} ODS ferritic steel have been examined using high-resolution transmission electron microscopy (HRTEM) techniques. Oxide nanoparticles with a complex-oxide core and an amorphous shell were frequently observed. The crystal structure of complex-oxide core is identified to be mainly monoclinic Y{sub 4}Al{sub 2}O{sub 9} (YAM) oxide compound. Orientation relationships between the oxide and matrix are found to be dependent on the particle size. Large particles (> 20 nm) tend to be incoherent and have a spherical shape, whereas small particles (< 10 nm) tend to be coherent or semi-coherent and have a faceted interface. The observations of partially amorphous nanoparticles lead us to propose three-stage mechanisms to rationalize the formation of oxide nanoparticles containing core/shell structures in as-fabricated ODS steels.

  13. Contribution to the development of the MARS beamline to study oxide dispersion strengthened steels (ODS) irradiated with neutrons using synchrotron source: secondary phases evolution under irradiation

    International Nuclear Information System (INIS)

    Menut, Denis

    2016-01-01

    X-Ray Diffraction (XRD) coupled with X-ray Absorption Fine Structure (XAFS) analyses at the MARS beamline of the synchrotron SOLEIL facility were used to study the microstructural evolution of oxides phases found in oxide dispersion strengthened steels (ODS) irradiated in Material Testing Reactors. Two hold generations of ODS steel grades (DY and MA957) irradiated up to high fluencies (∼75 dpa) were studied. These experiments have required specific developments, in particular a dedicated sample holder. An important milestone was overcome integrating the MARS beamline to the nuclearized facilities accessible for CEA. First, XRD analysis provide new results concerning intermediate sizes of precipitates (around 100 nm) essentially from crystallographic point of view, the nano-sized oxides (from 1 to 10 nm) being not detected, due to the material itself, sample preparation as thin foil and experimental set-up calibration. Secondly, XAFS analysis is not a discriminating technique as soon as the absorber atom is involved in the chemical composition of various precipitates found in ODS. Nevertheless, the stability of the Ti with a coordination number of 5 is evidenced whatever the irradiation conditions. As our experimental study was not able to detect the nano-sized oxides, an alternative way is to perform modeling approach of the behavior of massive oxides under irradiation, compared to experimental analyses under ion irradiations. We have shown that the defect fluorite is an intermediate phase of the crystal-to-amorphous phase transition of the pyrochlore oxide structure, whatever the irradiation conditions and the ratio of the cationic radii, the Ti coordination number remaining around 5 in the amorphous state. (author) [fr

  14. Preparation of WO3/g-C3N4 composites and their application in oxidative desulfurization

    Science.gov (United States)

    Zhao, Rongxiang; Li, Xiuping; Su, Jianxun; Gao, Xiaohan

    2017-01-01

    WO3/graphitic carbon nitride (g-C3N4) composites were successfully synthesized through direct calcining of a mixture of WO3 and g-C3N4 at 400 °C for 2 h. The WO3 was prepared by calcination of phosphotungstic acid at 550 °C for 4 h, and the g-C3N4 was obtained by calcination of melamine at 520 °C for 4 h. The WO3/g-C3N4 composites were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and Brunner-Emmett-Teller analysis (BET). The WO3/g-C3N4 composites exhibited stronger XRD peaks of WO3 and g-C3N4 than the WO3 and pure g-C3N4. In addition, two WO3 peaks at 25.7° and 26.6° emerged for the 36% -WO3/g-C3N4 composite. This finding indicated that WO3 was highly dispersed on the surface of the g-C3N4 nanosheets and interacted with the nanosheets, which resulted in the appearance of (012) and (022) planes of WO3. The WO3/g-C3N4 composite also exhibited a larger specific surface area and higher degree of crystallization than WO3 or pure g-C3N4, which resulted in high catalytic activity of the catalyst. Desulfurization experiments demonstrated that the desulfurization rate of dibenzothiophene (DBT) in model oil reached 91.2% under optimal conditions. Moreover, the activity of the catalyst was not significantly decreased after five recycles.

  15. Selective catalytic oxidation: a new catalytic approach to the desulfurization of natural gas and liquid petroleum gas for fuel cell reformer applications

    Science.gov (United States)

    Lampert, J.

    In both natural gas and liquid petroleum gas (LPG), sulfur degrades the performance of the catalysts used in fuel reformers and fuel cells. In order to improve system performance, the sulfur must be removed to concentrations of less than 200 ppbv (in many applications to less than 20 ppbv) before the fuel reforming operation. Engelhard Corporation presents a unique approach to the desulfurization of natural gas and LPG. This new method catalytically converts the organic and inorganic sulfur species to sulfur oxides. The sulfur oxides are then adsorbed on a high capacity adsorbent. The sulfur compounds in the fuel are converted to sulfur oxides by combining the fuel with a small amount of air. The mixture is then heated from 250 to 270 °C, and contacted with a monolith supported sulfur tolerant catalyst at atmospheric pressure. When Engelhard Corporation demonstrated this catalytic approach in the laboratory, the result showed sulfur breakthrough to be less than 10 ppbv in the case of natural gas, and less than 150 ppbv for LPG. We used a simulated natural gas and LPG mixture, doped with a 50-170 ppmv sulfur compound containing equal concentrations of COS, ethylmercaptan, dimethylsulfide, methylethylsulfide and tetrahydrothiophene. There is no need for recycled H 2 as in the case for hydrodesulfurization.

  16. Highly efficient extraction and oxidative desulfurization system using Na7H2LaW10O36⋅32 H2O in [bmim]BF4 at room temperature.

    Science.gov (United States)

    Xu, Junhua; Zhao, Shen; Chen, Wei; Wang, Miao; Song, Yu-Fei

    2012-04-10

    Highly efficient, deep desulfurization of model oil containing dibenzothiophene (DBT), benzothiophene (BT), or 4,6-dimethyldibenzothiophene (4,6-DMDBT) has been achieved under mild conditions by using an extraction and catalytic oxidative desulfurization system (ECODS) in which a lanthanide-containing polyoxometalate Na(7)H(2)LnW(10)O(36)⋅32 H(2)O (LnW(10); Ln = Eu, La) acts as catalyst, [bmim]BF(4) (bmim = 1-butyl-3-methylimidazolium) as extractant, and H(2)O(2) as oxidant. Sulfur removal follows the order DBT>4,6-DMDBT>BT at 30 °C. DBT can be completely oxidized to the corresponding sulfone in 25 min under mild conditions, and the LaW(10)/[bmim]BF(4) system could be recycled for ten times with only slight decrease in activity. Thus, LaW(10) in [bmim]BF(4) is one of the most efficient systems for desulfurization using ionic liquids as extractant reported so far. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Preparation of WO{sub 3}/g-C{sub 3}N{sub 4} composites and their application in oxidative desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Rongxiang, E-mail: zylhzrx@126.com; Li, Xiuping, E-mail: lilili_171717@126.com; Su, Jianxun; Gao, Xiaohan

    2017-01-15

    Highlights: • The WO{sub 3}/g-C{sub 3}N{sub 4} was successfully synthesized through simple calcination. • The process is simple and the cost raw materials is cheap. • The WO{sub 3}/g-C{sub 3}N{sub 4} firstly applied to ODS. • The desulpurization rate of WO{sub 3}/g-C{sub 3}N{sub 4} may attach to 91.2%. • Five recycles of WO{sub 3}/g-C{sub 3}N{sub 4} still attach to 89.5% due to heterogeneous catalysis. - Abstract: WO{sub 3}/graphitic carbon nitride (g-C{sub 3}N{sub 4}) composites were successfully synthesized through direct calcining of a mixture of WO{sub 3} and g-C{sub 3}N{sub 4} at 400 °C for 2 h. The WO{sub 3} was prepared by calcination of phosphotungstic acid at 550 °C for 4 h, and the g-C{sub 3}N{sub 4} was obtained by calcination of melamine at 520 °C for 4 h. The WO{sub 3}/g-C{sub 3}N{sub 4} composites were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and Brunner−Emmett−Teller analysis (BET). The WO{sub 3}/g-C{sub 3}N{sub 4} composites exhibited stronger XRD peaks of WO{sub 3} and g-C{sub 3}N{sub 4} than the WO{sub 3} and pure g-C{sub 3}N{sub 4}. In addition, two WO{sub 3} peaks at 25.7° and 26.6° emerged for the 36% −WO{sub 3}/g-C{sub 3}N{sub 4} composite. This finding indicated that WO{sub 3} was highly dispersed on the surface of the g-C{sub 3}N{sub 4} nanosheets and interacted with the nanosheets, which resulted in the appearance of (012) and (022) planes of WO{sub 3}. The WO{sub 3}/g-C{sub 3}N{sub 4} composite also exhibited a larger specific surface area and higher degree of crystallization than WO{sub 3} or pure g-C{sub 3}N{sub 4}, which resulted in high catalytic activity of the catalyst. Desulfurization experiments demonstrated that the desulfurization rate of dibenzothiophene (DBT) in model oil reached 91.2% under optimal conditions. Moreover, the activity of the catalyst was not significantly decreased after five recycles.

  18. Oxidation of refractory sulfur compounds over Ti-containing mesoporous molecular sieves prepared by using a fluorosilicon compound.

    Science.gov (United States)

    Jeong, Kwang-Eun; Cho, Chin-Soo; Chae, Ho-Jeong; Kim, Chul-Ung; Jeong, Soon-Yong

    2010-05-01

    Titanium containing mesoporous molecular sieve (Ti-MMS) catalysts were studied for the oxidative desulfurization of refractory sulfur compounds. Ti-MMS catalysts were synthesized from fluorosilicon compounds and Ti with the hydrolysis reaction of H2SiF6 in an ammonia-surfactant mixed solution. The solid products were characterized by XRD, XRF, nitrogen adsorption, and diffuse reflectance UV-vis spectroscopy. Effects of Ti loading and oxidant/sulfur mole ratio, and sulfur species on ODS activity were investigated.

  19. Investigation of process variables and intensification effects of ultrasound applied in oxidative desulfurization of model diesel over MoO3/Al2O3 catalyst.

    Science.gov (United States)

    Akbari, Azam; Omidkhah, Mohammadreza; Darian, Jafar Towfighi

    2014-03-01

    A new heterogeneous sonocatalytic system consisting of a MoO3/Al2O3 catalyst and H2O2 combined with ultrasonication was studied to improve and accelerate the oxidation of model sulfur compounds of diesel, resulting in a significant enhancement in the process efficiency. The influence of ultrasound on properties, activity and stability of the catalyst was studied in detail by means of GC-FID, PSD, SEM and BET techniques. Above 98% conversion of DBT in model diesel containing 1000 μg/g sulfur was obtained by new ultrasound-assisted desulfurization at H2O2/sulfur molar ratio of 3, temperature of 318 K and catalyst dosage of 30 g/L after 30 min reaction, contrary to the 55% conversion obtained during the silent process. This improvement was considerably affected by operation parameters and catalyst properties. The effects of main process variables were investigated using response surface methodology in silent process compared to ultrasonication. Ultrasound provided a good dispersion of catalyst and oxidant by breakage of hydrogen bonding and deagglomeration of them in the oil phase. Deposition of impurities on the catalyst surface caused a quick deactivation in silent experiments resulting only 5% of DBT oxidation after 6 cycles of silent reaction by recycled catalyst. Above 95% of DBT was oxidized after 6 ultrasound-assisted cycles showing a great improvement in stability by cleaning the surface during ultrasonication. A considerable particle size reduction was also observed after 3 h sonication that could provide more dispersion of catalyst in model fuel.

  20. THE BIOCATALYTIC DESULFURIZATION PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Steven E. Bonde; David Nunn

    2003-01-01

    During the first quarter of the Biological Desulfurization project several activities were pursued. A project kickoff meeting was held at the Diversa facility in San Diego, CA. Activities that were in process before the meeting and begun afterwards by Diversa Corporation and Petro Star Inc. include: Technology transfer in the form of information generated by Enchira to Diversa, the purchase and installation of equipment by Diversa, development of synthetic methods and preparation of organo-sulfur substrates for use in determining enzyme activities, production of extract via Petro Star's CED process, detailed analysis of Petro Star Inc. diesel and CED extract, and several activities in molecular biology. Diversa Corporation, in the area of molecular biology, engaged in several activities in support of the task list of the contract. These included: construction of a genomic library; development and utilization of a sequence-based gene discovery effort; a parallel discovery approach based on functional expression of enzymes with the ability to oxidize organosulfur compounds. Biodesulfurization genes have already been identified and are being sequenced and subcloned for expression in heterologous biological hosts. Diversa has evaluated and adapted assays developed by Enchira used to assess the activities of DBT and DBTO{sub 2} monooxygenases. Finally, Diversa personnel have developed two novel selection/screen strategies for the improvement of biocatalyst strains by directed evolution.

  1. Fatigue properties of MA 6000E, a gamma-prime strengthened ODS alloy. [Oxide Dispersion Strengthened Ni-base alloy for gas turbine blade applications

    Science.gov (United States)

    Kim, Y. G.; Merrick, H. F.

    1980-01-01

    MA 6000E is a corrosion resistant, gamma-prime strengthened ODS alloy under development for advanced turbine blade applications. The high temperature, 1093 C, rupture strength is superior to conventional nickel-base alloys. This paper addresses the fatigue behavior of the alloy. Excellent properties are exhibited in low and high cycle fatigue and also thermal fatigue. This is attributed to a unique combination of microstructural features, i.e., a fine distribution of dispersed oxides and other nonmetallics, and the highly elongated grain structure which advantageously modify the deformation characteristics and crack initiation and propagation modes from that characteristic of conventional gamma-prime hardened superalloys.

  2. Preparation and Characterization of MoO3/Al2O3 Catalyst for Oxidative Desulfurization of Diesel using H2O2: Effect of Drying Method and Mo Loading

    OpenAIRE

    Azam Akbari; Mohammadreza Omidkhah; Jafar Toufighi Darian

    2012-01-01

    The mesoporous MoO3/γ-Al2O3 catalyst was prepared by incipient wetness impregnation method aiming to investigate the effect of drying method and molybdenum content on the catalyst property and performance towards the oxidation of benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyle dibenzothiophene (4,6-DMDBT) with H2O2 for deep oxidative desulfurization of diesel fuel. The catalyst was characterized by XRD, BET, BJH and SEM method. The catalyst with 10wt.% and 1...

  3. Microstructure characterization and strengthening mechanisms of oxide dispersion strengthened (ODS) Fe-9%Cr and Fe-14%Cr extruded bars

    Science.gov (United States)

    Chauhan, A.; Bergner, F.; Etienne, A.; Aktaa, J.; de Carlan, Y.; Heintze, C.; Litvinov, D.; Hernandez-Mayoral, M.; Oñorbe, E.; Radiguet, B.; Ulbricht, A.

    2017-11-01

    The collaborative study is focused on the relationship between microstructure and yield stress for an ODS Fe-9%Cr-based transformable alloy and an ODS Fe-14%Cr-based ferritic alloy. The contributions to the total room temperature yield stress arising from various strengthening mechanisms are addressed on the basis of a comprehensive description of the microstructures uncovered by means of transmission electron microscopy (TEM), electron backscatter diffraction (EBSD), small-angle neutron scattering (SANS) and atom probe tomography (APT). While these methods provide a high degree of complementarity, a reasonable agreement was found in cases of overlap of information. The derived set of microstructure parameters along with reported strengthening equations was used to calculate the room temperature yield stress. The estimates were critically compared with the measured yield stress for an extended set of alloys including data reported for Fe-Cr model alloys and steels thus covering one order of magnitude or more in grain size, dislocation density, particle density and yield stress. The comparison shows that particle strengthening, dislocation forest strengthening, and Hall-Petch strengthening are the major contributions and that a mixed superposition rule reproduces the measured yield stress within experimental scatter for the whole extended set of alloys. The wide variation of microstructures additionally underpins the conclusions and goes beyond previous work, in which one or few ODS steels and narrow microstructure variations were typically covered.

  4. ODS Alloys for Nuclear Applications

    International Nuclear Information System (INIS)

    Jang, Jin Sung

    2006-01-01

    ODS (oxide dispersion strengthening) alloy is one of the potential candidate alloys for the cladding or in reactor components of Generation IV reactors and for the structural material even for fusion reactors. It is widely accepted as very resistant material to neutron irradiation as well as strong material at high temperature due to its finely distributed and stable oxide particles. Among Generation IV reactors SFR and SCWR are anticipated in general to run in the temperature range between 300 and 550 .deg. C, and the peak cladding temperature is supposed to reach at about 620 .deg. C during the normal operation. Therefore Zr.base alloys, which have been widely known and adopted for the cladding material due to their excellent neutron economics, are no more adequate at these operating conditions. Fe-base ODS alloys in general has a good high temperature strength at the above high temperature as well as the neutron resistance. In this study a range of commercial grade ODS alloys and their applications are reviewed, including an investigation of the stability of a commercial grade 20% Cr Fe-base ODS alloy(MA956). The alloy was evaluated in terms of the fracture toughness change along with the aging treatment. Also an attempt of the development of 9% Cr Fe-base ODS alloys is introduced

  5. Desulfurization of chalcopyrite and molybdenite by atomic hydrogen

    International Nuclear Information System (INIS)

    Bagdasaryan, V.R.; Kosoyan, A.Zh.; Niazyan, O.M.

    1989-01-01

    Molybdenite (MoS 2 ) desulfurization by monatomic hydrogen in 625-800 K range was studied using helium as diluent gas. Desulfurization degree at 680 K equals 9%. Temperature growth elevates sulfur content in molybdenite. The effect of initial molybdenite enrichment with temperature growth up to 800 K is probably caused by removal of reduced molybdenum capable to form oxide in the presence of traces of oxygen contained in inert diluent gas

  6. Preparation and characterization of nanocomposite of graphitic carbon nitride and TiO2 as a porous support for nano catalyst for desulfurization process

    Directory of Open Access Journals (Sweden)

    Ezzat Rafiee

    2017-12-01

    Full Text Available A novel heterogeneous nanocatalyst H3PW12O40/TiO2/g-C3N4 (PW/TiO2/CN was successfully synthesized by immobilization of PW on TiO2/CN nanocomposite, and characterized by SEM, BET, FT-IR, XRD, EDX, TEM and ICP. Catalytic performance of the as-prepared catalyst was investigated for the selective oxidation of sulfides to sulfoxides and sulfones in the presence of H2O2 as oxidant with good conversion and high selectivity. The main factors influencing the ability for selective oxidation of sulfides were studied, including reaction temperature, amounts of the catalyst, H2O2 and type of the reaction solvent. Catalytic oxidation of the different model oils containing dibenzothiophene (DBT, benzothiophene (BT and thiophene (T into corresponding sulfone was also studied. Effects of different extractive solvents, aromatics, alkenes and nitrogen compounds on the oxidative desulfurization processes (ODS were also studied. In addition, reducing the level of sulfur content in real oil was investigated. The recyclability of the PW/TiO2/CN nanocatalyst for various cycles without a significant loss of activity was proved. The heterogeneity of the as-prepared catalyst was confirmed by leaching tests. Keywords: Graphitic carbon nitride, Extraction, Tetrabutyl titanate, Heteropoly acid, Oxidative desulfurization, Oil

  7. Material properties of oxide dispersion strengthened (ODS) ferritic steels for core materials of FBR. Mechanical strength properties of sodium exposed and Nickel diffused materials. Interim report

    International Nuclear Information System (INIS)

    Kato, Shoichi; Yoshida, Eiichi

    2004-02-01

    An oxide dispersion strengthened (ODS) ferritic steel have excellent resistance to swelling and superior creep strength, they are expected to be used as a long-life cladding material in future advanced fast reactor. In this study, sodium environmental effects on the ODS steel developed by JNC were clarified through tensile test after sodium exposure for maximum 10,000hrs and creep-rupture test in sodium at elevated temperature. The exposure to sodium was conducted using a sodium test loop constituted by austenitic steels. For the conditions of sodium exposure test, the sodium temperatures were 923 K and 973 K, the oxygen concentration in sodium was below 2ppm and sodium flow rate on the surface of specimen was less than 1x10 -4 m/s. Further the specimen with the nickel diffused was prepared, which is simulate to nickel diffusing through sodium from the surface of structural stainless steels. The main results obtained were as follows; (1) The results showed excellent sodium-resistance up to a high temperature of about 973 K in stagnant sodium conditions, and its considered that the effects of sodium environment of tensile properties were negligible. In case of stagnant sodium condition, creep-rupture strength in sodium was equal to the in argon gas, and no sodium environmental effect was observed. The same is true for the creep-rupture ductility. (2) The tensile properties of nickel diffused test specimens at high temperatures simulating microstructure change were equal to that of the thermal aging process specimens. These tensile tests suggest that sodium environmental effects can be ignored. However, the effect of nickel diffusion on creep strength are not clear at present and experimental investigation are being conducted. (3) The coefficient of nickel diffusion in the ODS steel can be estimated based on the results of nickel concentration measurement. This value is larger than that of the diffusion coefficient for typical α-Fe steel at temperature below 973 K

  8. Polymer-bound oxidovanadium(IV) and dioxidovanadium(V) complexes as catalysts for the oxidative desulfurization of model fuel diesel.

    Science.gov (United States)

    Maurya, Mannar R; Arya, Aarti; Kumar, Amit; Kuznetsov, Maxim L; Avecilla, Fernando; Costa Pessoa, João

    2010-07-19

    The Schiff base (Hfsal-dmen) derived from 3-formylsalicylic acid and N,N-dimethyl ethylenediamine has been covalently bonded to chloromethylated polystyrene to give the polymer-bound ligand, PS-Hfsal-dmen (I). Treatment of PS-Hfsal-dmen with [V(IV)O(acac)(2)] in the presence of MeOH gave the oxidovanadium(IV) complex PS-[V(IV)O(fsal-dmen)(MeO)] (1). On aerial oxidation in methanol, complex 1 was oxidized to PS-[V(V)O(2)(fsal-dmen)] (2). The corresponding neat complexes, [V(IV)O(sal-dmen)(acac)] (3) and [V(V)O(2)(sal-dmen)] (4) were similarly prepared. All these complexes are characterized by various spectroscopic techniques (IR, electronic, NMR, and electron paramagnetic resonance (EPR)) and thermal as well as field-emission scanning electron micrographs (FE-SEM) studies, and the molecular structures of 3 and 4 were determined by single crystal X-ray diffraction. The EPR spectrum of the polymer supported V(IV)O-complex 1 is characteristic of magnetically diluted V(IV)O-complexes, the resolved EPR pattern indicating that the V(IV)O-centers are well dispersed in the polymer matrix. A good (51)V NMR spectrum could also be measured with 4 suspended in dimethyl sulfoxide (DMSO), the chemical shift (-503 ppm) being compatible with a VO(2)(+)-center and a N,O binding set. The catalytic oxidative desulfurization of organosulfur compounds thiophene, dibenzothiophene, benzothiophene, and 2-methyl thiophene (model of fuel diesel) was carried out using complexes 1 and 2. The sulfur in model organosulfur compounds oxidizes to the corresponding sulfone in the presence of H(2)O(2). The systems 1 and 2 do not loose efficiency for sulfoxidation at least up to the third cycle of reaction, this indicating that they preserve their integrity under the conditions used. Plausible intermediates involved in these catalytic processes are established by UV-vis, EPR, (51)V NMR, and density functional theory (DFT) studies, and an outline of the mechanism is proposed. The (51)V NMR spectra

  9. Microstructure and phase analysis of Zirconia-ODS (Oxide Dispersion Strengthen) alloy sintered by APS with milling time variation

    Science.gov (United States)

    Sugeng, Bambang; Bandriyana, B.; Sugeng, Bambang; Salam, Rohmad; Sumariyo; Sujatno, Agus; Dimyati, Arbi

    2018-03-01

    Investigation on the relationship between the process conditions of milling time and the microstructure on the synthesis of the zirconia-ODS steel alloy has been performed. The elemental composition of the alloy was determined on 20 wt% Cr and zirconia dispersoid of 0.50 wt%. The synthesis was carried out by powder metallurgy method with milling time of 3, 5 and 7 hours, static compression of 20 Ton and sintering process for 4 minutes using the APS (Arc Plasma Sintering) equipment. SEM-EDX and XRD test was carried out to characterize the phase and morphology of the alloy and the effect to the mechanical properties was evaluated by the Vickers Hardness testing. The synthesis produced sample of ODS steel with good dense and very little porous with the Fe-Cr phase that clearly observed in the XRD peak pattern. In addition milling time increased the homogeneously of Fe-Cr phase formulation, enhanced the grain refinement of the structure and increase the hardness of the alloy.

  10. A New Approach to Deep Desulfurization of Light Cycle Oil over Ni2P Catalysts: Combined Selective Oxidation and Hydrotreating

    Directory of Open Access Journals (Sweden)

    Gwang-Nam Yun

    2018-03-01

    Full Text Available Amphiphilic phosphotungstic acid (A-PTA and Ni2P/SBA-15 catalysts were prepared to apply for selective oxidation of refractory sulfur compounds in light cycle oils and hydrotreating of the oxidized S compounds, respectively. Physical properties of the catalyst samples were analyzed by BET, CO uptake chemisorption, and TEM. Structural properties for the supported Ni2P catalysts were analyzed by X-ray diffraction (XRD and extended X-ray absorption fine structure (XAFS spectroscopy. The selective oxidation of S compounds in the LCO feed was conducted in a batch reactor at H2O2/S ratio of 10, atmospheric pressure and 353 K and then the products were fed to a continuous flow fixed-bed reactor for hydrotreating at 623 K, 3.0 MPa, and LHSV’s of 0.5–2.0 h−1. A-PTA catalyst showed a high oxidation conversion of 95% for a real LCO feed. The following hydrotreating led to a hydrodesulfurization (HDS conversion of 99.6% and a hydrodenitrogenation (HDN conversion of 94.7% over Ni2P/SBA-15, which were much higher than those of direct hydrotreating results which gave an HDS conversion of 63.5% and an HDN conversion of 17.5% based on the same LHSV of 2.0 h−1. It was revealed that the reduction in refractory nitrogen compounds after oxidative treatment contributed to the increase of the following HDS activity.

  11. Method of treating final products from flue gas desulfurization

    International Nuclear Information System (INIS)

    Bloss, W.; Mohn, U.

    1984-01-01

    A method of treating final products from a flue gas desulfurization. The flue gas desulfurization is carried out by the absorption of sulfur oxide in a spray dryer with a suspension which contains lime, or in a reactor with a dry, fine-grained, absorbent which contains lime. Prior to desulfurization, the fly ash carried along by the flue gas which is to be desulfurized is separated entirely, partially, or not at all from the flue gas, and the final products from the flue gas desulfurization, prior to any further treatment thereof, amount to 1-99% by weight, preferably 1-70% by weight, of fly ash, and 1-99% by weight, preferably 30-99% by weight, of the sum of the desulfurization products, preferably calcium sulfite hemihydrate, and/or calcium sulfite, and/or calcium sulfate dyhydrate, and/or calcium sulfate hemihydrate, and/or calcium sulfate, as well as residue of the absorbent. The reduction of the amount of calcium sulfite is implemented by a dry oxidation with air

  12. Material properties of oxide dispersion strengthened (ODS) ferritic steels for core materials of FBR. Tensile properties of sodium exposed and nickel diffused materials

    International Nuclear Information System (INIS)

    Kato, Shoichi; Yoshida, Eiichi

    2002-12-01

    An oxide dispersion strengthened (ODS) ferritic steel is candidate for a long-life core materials of future FBR, because of good swelling resistance and high creep strength. In this study, tensile tests were carried out the long-term extrapolation of sodium environmental effects on the mechanical properties of ODS steels. The tested heats of materials are M93, M11 and F95. The specimens were pre-exposed to sodium for 1,000 and 3,000 hours under non-stress conditions. The pre-exposure to sodium was conducted using a sodium test loop constituted by austenitic steels. For the conditions of sodium exposure test, the sodium temperature was 650 and 700degC, the oxygen concentration in sodium was about 1 ppm and sodium flow rate on the surface of specimen was less than 1x10 -4 m/seconds (nearly static). Further the specimen with the nickel diffused was prepared, which is simulate to nickel diffusing through sodium from the surface of structural stainless steels. The main results obtained were as follows; (1) The tensile strength and the fracture elongation after sodium exposure (maximum 3,000 hours) were same as that of as-received materials. If was considered that the sodium environmental effect is negligible under the condition of this study. (2) Tensile properties of nickel diffused specimens were slightly lower than that of the as-received specimens, but it remains equal to that of thermal aging specimens. (3) The change in microstructure such as a degraded layer was observed on the surface of nickel diffused specimen. In the region of the degraded layer, phase transformations from the α-phase to the γ-phase were recognized. But, the microscopic oxide particles were observed same as that of α-phase base metal. (author)

  13. Ultra-deep desulfurization via reactive adsorption on peroxophosphomolybdate/agarose hybrids.

    Science.gov (United States)

    Xu, Jian; Li, Huacheng; Wang, Shengtian; Luo, Fang; Liu, Yunyu; Wang, Xiaohong; Jiang, Zijiang

    2014-09-01

    A catalyst system composed of peroxophosphomolybdates as catalytic center and agarose as matrix material had been designed. The [C16H33N(CH3)3]3[PO4{MoO(O2)2}4]/agarose (C16PMo(O2)2/agarose) hybrid was found to be active for oxidation desulfurization (ODS) of dibenzothiophene (DBT) or real fuel into corresponding sulfone by H2O2 as an oxidant, while the sulfur content could be reduced to 5ppm. The higher activity comes from its components including [PO4{MoO(O2)2}4] catalytic sites, the hydrophobic quaternary ammonium cation affinity to low polarity substrates, and agarose matrix affinity to H2O2 and sulfone. During the oxidative reaction, the mass transfer resistance between H2O2 and organic sulfurs could be decreased and the reaction rate could increase by the assistance of agarose and hydrophobic tails of [C16H33N(CH3)3]3[PO4{MoO(O2)2}4]. Meanwhile, the oxidative products could be adsorbed by agarose matrix to give clean fuel avoiding the post-treatment. In addition, the hybrid was easily regenerated to be reused. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Evidence of desulfurization in the oxidative cyclization of thiosemicarbazones. Conversion to 1,3,4-oxadiazole derivatives.

    Science.gov (United States)

    Gómez-Saiz, Patricia; García-Tojal, Javier; Maestro, Miguel A; Arnaiz, Francisco J; Rojo, Teófilo

    2002-03-25

    The addition of pyridine-2-carbaldehyde 4N-methylthiosemicarbazone (C8H10N4S) to an aqueous solution of copper(II) nitrate yields [[Cu(C8H9N4S)(NO3)]2] (1). This complex consists of centrosymmetric dinuclear entities containing square-pyramidal copper(II) ions bridged through the sulfur thioamide atoms. The oxidation of 1 with KBrO3 or KIO3 gives rise to a compound with formula [[Cu(C8H8N4O)(H2O)2(SO4)]2]*2H2O (2) (C8H8N4O = 2-methylamino-5-pyridin-2-yl-1,3,4-oxadiazole). The structure of 2 is made up of centrosymmetric dimers where the copper(II) ions exhibit a distorted octahedral coordination and are connected by the oxadiazole moiety. The metal ions in 2 can be removed by addition of K4[Fe(CN)6], and then the oxadiazole ligand can be isolated and recrystallized as (C8H8N4O)*3H2O (3).

  15. Method for enhancing the desulfurization of hot coal gas in a fluid-bed coal gasifier

    Science.gov (United States)

    Grindley, Thomas

    1989-01-01

    A process and apparatus for providing additional desulfurization of the hot gas produced in a fluid-bed coal gasifier, within the gasifier. A fluid-bed of iron oxide is located inside the gasifier above the gasification bed in a fluid-bed coal gasifier in which in-bed desulfurization by lime/limestone takes place. The product gases leave the gasification bed typically at 1600.degree. to 1800.degree. F. and are partially quenched with water to 1000.degree. to 1200.degree. F. before entering the iron oxide bed. The iron oxide bed provides additional desulfurization beyond that provided by the lime/limestone.

  16. ODS alloys for structures subjected to irradiation

    International Nuclear Information System (INIS)

    Carlan, Y. de

    2010-01-01

    ODS (oxide-dispersion-strengthened) materials are considered for cladding purposes for the fourth-generation sodium-cooled fast reactors. ODS materials afford many benefits. Indeed, these high-performance materials combine, at the same time, remarkable mechanical strength, in hot conditions, and outstanding irradiation behavior. New ODS steel grades, exhibiting better performance levels than the last-generation austenitic steels, afford not only negligible swelling under irradiation, owing to their 'ferritic' body-centered cubic structure - by contrast to austenitic grades, which feature a face-centered cubic structure - but equally outstanding creep properties, owing to the nano-reinforcements present in the matrix. ODS materials are obtained by powder metallurgy, the first fabrication step involves co-grinding a metal powder together with yttrium oxide (Y 2 O 3 ) powder. At this stage, an iron oxide may also be added, or an yttrium-rich intermetallic compound in order to provide the amounts of yttrium, and oxygen required for the formation of nano-oxides. The metal powder consists of a powder pre-alloyed to the chemical composition of the desired material. Once the powder has been obtained, consolidation of the ODS materials is achieved either by hot extrusion, or by hot isostatic pressing. (A.C.)

  17. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

    Energy Technology Data Exchange (ETDEWEB)

    Jha, M.C.; Berggren, M.H.

    1989-05-02

    AMAX Research Development Center (AMAX R D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

  18. The effects of oxide evolution on mechanical properties in proton- and neutron-irradiated Fe-9%Cr ODS steel

    Energy Technology Data Exchange (ETDEWEB)

    Swenson, M.J., E-mail: matthewswenson1@u.boisestate.edu [Boise State University, 1910 University Drive, Boise, ID 83725 (United States); Dolph, C.K. [Boise State University, 1910 University Drive, Boise, ID 83725 (United States); Wharry, J.P. [Boise State University, 1910 University Drive, Boise, ID 83725 (United States); Purdue University, 400 Central Drive, West Lafayette, IN 47907 (United States)

    2016-10-15

    The objective of this study is to evaluate the effect of irradiation on the strengthening mechanisms of a model Fe-9%Cr oxide dispersion strengthened steel. The alloy was irradiated with protons or neutrons to a dose of 3 displacements per atoms at 500 °C. Nanoindentation was used to measure strengthening due to irradiation, with neutron irradiation causing a greater increase in yield strength than proton irradiation. The irradiated microstructures were characterized using transmission electron microscopy and atom probe tomography (APT). Cluster analysis reveals solute migration from the Y-Ti-O-rich nanoclusters to the surrounding matrix after both irradiations, though the effect is more pronounced in the neutron-irradiated specimen. Because the dissolved oxygen atoms occupy interstitial sites in the iron matrix, they contribute significantly to solid solution strengthening. The dispersed barrier hardening model relates microstructure evolution to the change in yield strength, but is only accurate if solid solution contributions to strengthening are considered simultaneously.

  19. Characterization of residual stress as a function of friction stir welding parameters in oxide dispersion strengthened (ODS) steel MA956

    Energy Technology Data Exchange (ETDEWEB)

    Brewer, L.N., E-mail: lnbrewer1@eng.ua.edu [Naval Postgraduate School (United States); Bennett, M.S.; Baker, B.W. [Naval Postgraduate School (United States); Payzant, E.A.; Sochalski-Kolbus, L.M. [Oak Ridge National Laboratory (United States)

    2015-10-28

    Friction stir welding (FSW) can generate large residual stresses during solid state joining of oxide dispersion strengthened steels. In this work, a plate of MA956 steel was friction stir welded at three conditions: 500 rpm/25 mm per minute (mmpm), 400 rpm/50 mmpm and 400 rpm/100 mmpm. The residual stresses across these welds were measured using both x-ray and neutron diffraction techniques. The distribution and magnitude of the residual stresses agreed well between the two techniques. Longitudinal residual stresses up to eighty percent of the yield strength were observed for the 400 rpm/100 mmpm condition. The surface residual stresses were somewhat larger on the root side of the weld than on the crown side. Increases in the relative heat input during FSW decreased the measured residual stresses in the stir zone and the thermomechanically affected zone (TMAZ). Increasing the traverse rate while holding the rotational speed fixed increased the residual stress levels. The fatigue strength of the material is predicted to decrease by at least twenty percent with cracking most likely in the TMAZ.

  20. Characterization of residual stress as a function of friction stir welding parameters in oxide dispersion strengthened (ODS) steel MA956

    International Nuclear Information System (INIS)

    Brewer, L.N.; Bennett, M.S.; Baker, B.W.; Payzant, E.A.; Sochalski-Kolbus, L.M.

    2015-01-01

    Friction stir welding (FSW) can generate large residual stresses during solid state joining of oxide dispersion strengthened steels. In this work, a plate of MA956 steel was friction stir welded at three conditions: 500 rpm/25 mm per minute (mmpm), 400 rpm/50 mmpm and 400 rpm/100 mmpm. The residual stresses across these welds were measured using both x-ray and neutron diffraction techniques. The distribution and magnitude of the residual stresses agreed well between the two techniques. Longitudinal residual stresses up to eighty percent of the yield strength were observed for the 400 rpm/100 mmpm condition. The surface residual stresses were somewhat larger on the root side of the weld than on the crown side. Increases in the relative heat input during FSW decreased the measured residual stresses in the stir zone and the thermomechanically affected zone (TMAZ). Increasing the traverse rate while holding the rotational speed fixed increased the residual stress levels. The fatigue strength of the material is predicted to decrease by at least twenty percent with cracking most likely in the TMAZ.

  1. Biological flue gas desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Buisman, C.J.N.; Dijkman, H.; Wijte, G.; Prins, W.L.; Verbraak, P.; Hartog, H.A.J. den [Paper B.V. Blak (Netherlands)

    1995-08-01

    A new biological flue gas desulfurization process (BIO-FGD) producing sulphur as a by-product was invented by Paques BV and Hoogens Technical Services in 1993. Sulphur dioxide is absorbed from flue gas using a combination of a sodium based scrubber and two biological reactors, an anaerobic and an aerobic biological reactor. The article describes the process and its evaluation in a pilot plant at 2 MW scale, designed to remove 6 kg/hr SO{sub 2} of the 2 million m{sup 3}/hr of flue gas produced at the 600 MW coal fired power station Amer-8 situated in Geertruidenberg in the south of the Netherlands. Research so far has proved the process works successfully and at low cost. A second pilot plant due to start-up in May 1995 will provide data on scale up and further information on sulphur recovery. 5 refs., 5 figs.

  2. Biological (flue) gas desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Buisman, C.J.N.; Dijkman, H. [PAQUES, Balk (Netherlands); Prins, W.L.; Verbraak, P. [Biostar CV, Balk (Netherlands); Den Hartog, A.J. [Hoogovens Groep BV, IJmuiden (Netherlands)

    1995-12-31

    Biotechnological research has been carried out to find new micro-organisms and processes to make useful products, and to reveal new ways and biotechnological mechanisms to produce elemental sulfur in waste water treatment. Biotechnological development work has been carried out and the first commercial installation (on 300 m{sup 3}/hr scale) to produce sulfur from polluted waste water was started up in 1992. The importance of this recent research and development in the area of waste water treatment was recognized. In an intensive cooperation between Hoogovens Technical Services and PACQUES the concept for a totally new Biological Flue Gas Desulfurization process (BIO-FGD), producing sulfur as by-product, was invented. It consists of the combination of a sodium scrubber with two biological reactors resulting in a very attractive new concept for a gas cleaning process. A description of the process is given and the pilot plant results are outlined. 4 figs., 5 refs.

  3. Process for desulfurizing hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    1937-04-12

    A process is described for the desulfurization of a mixture of hydrocarbons, and in particular hydrocarbons containing less than 7 atoms of carbon and sulfur compounds of the type of sulfur carbonyl, characterized by the fact that the mixture, preferably in the liquid phase, is brought in contact with a solution of caustic alkali, essentially anhydrous or preferably with a solution of alkali hydroxide in an organic hydroxy nonacid solvent, for example, an alcohol, or with an alkaline alcoholate, under conditions suitable to the formation of hydrogen sulfide which produces a hydrocarbon mixture free from sulfur compounds of the sulfur carbonyl type but containing hydrogen sulfide, and that it is treated, following mixing, having beem submitted to the first treatment, by means of aqueous alkaline hydroxide to eliminate the hydrogen sulfide.

  4. Developing clean fuels: Novel techniques for desulfurization

    Science.gov (United States)

    Nehlsen, James P.

    The removal of sulfur compounds from petroleum is crucial to producing clean burning fuels. Sulfur compounds poison emission control catalysts and are the source of acid rain. New federal regulations require the removal of sulfur in both gasoline and diesel to very low levels, forcing existing technologies to be pushed into inefficient operating regimes. New technology is required to efficiently produce low sulfur fuels. Two processes for the removal of sulfur compounds from petroleum have been developed: the removal of alkanethiols by heterogeneous reaction with metal oxides; and oxidative desulfurization of sulfides and thiophene by reaction with sulfuric acid. Alkanethiols, common in hydrotreated gasoline, can be selectively removed and recovered from a hydrocarbon stream by heterogeneous reaction with oxides of Pb, Hg(II), and Ba. The choice of reactive metal oxides may be predicted from simple thermodynamic considerations. The reaction is found to be autocatalytic, first order in water, and zero order in thiol in the presence of excess oxide. The thiols are recovered by reactive extraction with dilute oxidizing acid. The potential for using polymer membrane hydrogenation reactors (PEMHRs) to perform hydrogenation reactions such as hydrodesulfurization is explored by hydrogenating ketones and olefins over Pt and Au group metals. The dependence of reaction rate on current density suggests that the first hydrogen addition to the olefin is the rate limiting step, rather than the adsorption of hydrogen, for all of the metals tested. PEMHRs proved unsuccessful in hydrogenating sulfur compounds to perform HDS. For the removal of sulfides, a two-phase reactor is used in which concentrated sulfuric acid oxidizes aromatic and aliphatic sulfides present in a hydrocarbon solvent, generating sulfoxides and other sulfonated species. The polar oxidized species are extracted into the acid phase, effectively desulfurizing the hydrocarbon. A reaction scheme is proposed for this

  5. The Study of the Desulfurization Process of Oil and Oil Products of "Zhanazhol" Oil Field Using the Approaches of Green Chemistry

    OpenAIRE

    Zhaksyntay K. Kairbekov; Zhannur K. Myltykbaeva; Nazym T. Smagulova; Dariya K. Kanseitova

    2015-01-01

    In this paper we studied sono catalytic oxidative desulfurization of oil and diesel fraction from “Zhanazhol” oil deposits. We have established that the combined effect of the ultrasonic field and oxidant (ozone-air mixture) in the presence of the catalyst on the oil is potentially very effective method of desulfurization of oil and oil products. This method allows increasing the degree of desulfurization of oil by 62%.

  6. Nano-magnetic particles as multifunctional microreactor for deep desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Xinai; Yao, Dongdong [Engineering Research Center of Historical and Cultural Heritage Protection, Ministry of Education, School of Materials Science and Engineering, Shaanxi Normal University, Xi' an 710062 (China); Li, Hong [College of Environment and Chemical Engineering, Xi' an Polytechnic University, Xi' an 710048 (China); Yang, Juxiang [Department of Chemistry, Xi' an University of Arts and Science, Xi' an 710065 (China); Hu, Daodao, E-mail: daodaohu@snnu.edu.cn [Engineering Research Center of Historical and Cultural Heritage Protection, Ministry of Education, School of Materials Science and Engineering, Shaanxi Normal University, Xi' an 710062 (China)

    2012-02-29

    Highlights: Black-Right-Pointing-Pointer An easy-separated amphiphilic catalyst with small size was prepared for deep desulfurization. Black-Right-Pointing-Pointer The effects of several factors on desulfurization reactivity were systematically investigated. Black-Right-Pointing-Pointer The catalyst demonstrates high performance in the deep desulfurization. Black-Right-Pointing-Pointer The material could make integration of micro-reactor and micro-extractor into one system. - Abstract: Oxidation of dibenzothiophene with hydrogen peroxide using a recyclable amphiphilic catalyst has been studied. The catalyst was synthesized by surfacely covering magnetic silica nanospheres (MSN) with the complexes between 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride (AEM) and phosphotungstic acid (PTA). The morphology and components of the composite material were characterized by TEM, EDX, XPS, FT-IR, and VSM, respectively. The effects of several factors on desulfurization reactivity were systematically investigated. The results showed that the composite nanospheres have core/shell structure with the properties of amphiphilicity and superparamagnetism. The composite nanospheres have high catalytic activity in the oxidation of dibenzothiophene to corresponding sulfones by hydrogen peroxide under mild reaction conditions. The sulfur level could be lowered from 487 ppm to less than 0.8 ppm under optimal conditions. Additionally, the amphiphilic catalyst and the oxidized product could be simultaneously separated from medium by external magnetism, and the recovered composite material could be recycled for three times with almost constant activity.

  7. Nano-magnetic particles as multifunctional microreactor for deep desulfurization

    International Nuclear Information System (INIS)

    Cui, Xinai; Yao, Dongdong; Li, Hong; Yang, Juxiang; Hu, Daodao

    2012-01-01

    Highlights: ► An easy-separated amphiphilic catalyst with small size was prepared for deep desulfurization. ► The effects of several factors on desulfurization reactivity were systematically investigated. ► The catalyst demonstrates high performance in the deep desulfurization. ► The material could make integration of micro-reactor and micro-extractor into one system. - Abstract: Oxidation of dibenzothiophene with hydrogen peroxide using a recyclable amphiphilic catalyst has been studied. The catalyst was synthesized by surfacely covering magnetic silica nanospheres (MSN) with the complexes between 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride (AEM) and phosphotungstic acid (PTA). The morphology and components of the composite material were characterized by TEM, EDX, XPS, FT-IR, and VSM, respectively. The effects of several factors on desulfurization reactivity were systematically investigated. The results showed that the composite nanospheres have core/shell structure with the properties of amphiphilicity and superparamagnetism. The composite nanospheres have high catalytic activity in the oxidation of dibenzothiophene to corresponding sulfones by hydrogen peroxide under mild reaction conditions. The sulfur level could be lowered from 487 ppm to less than 0.8 ppm under optimal conditions. Additionally, the amphiphilic catalyst and the oxidized product could be simultaneously separated from medium by external magnetism, and the recovered composite material could be recycled for three times with almost constant activity.

  8. Metallurgical comparison between the experimental ED-ODS and commercial ODS steels

    International Nuclear Information System (INIS)

    Fernandez, P.; Serrano, M.; Lapena, J.

    2007-01-01

    Full text of publication follows: Recently, reduced activation oxide dispersion strengthened ferritic/martensitic steels have been identified as potential structural material candidates for first wall and blanket structures of fusion devices. These steels allow to increase the operation temperature of the fusion reactor, around of 100 deg. C or even more, because of their excellent thermal creep resistance. ODS steels are being developed and investigated for nuclear fission and fusion applications in Japan, Europe and the United States. Commercial ODS products, such as MA956 and PM2000 are available and are being used for high temperature applications. Since no reduced activation ferritic/martensitic steels are commercially available at present, the European Materials Fusion Programme has considered in the last years initiate adequate research activities to produce and characterize these materials to evaluate the feasibility of their use in the different blanket designs. Nowadays, the ODS steel that are being extensively investigated in Europe is the denominated EU-ODS. This alloy has the basic composition of the Eurofer'97 with 0.3% of Y 2 O 3 particles. In this paper, the metallurgical properties (microstructural, Charpy, etc) of the newly developed EU-ODS steel are presented and discussed together with the properties of the commercial MA956 and PM2000 ODS steels, also studied in this work, in order to show the differences and similarities between these ODS alloys. (authors)

  9. Microbiological desulfurization and conversion of coal

    International Nuclear Information System (INIS)

    Quigley, D.R.; Stoner, D.L.; Dugan, P.R.

    1991-01-01

    Bio processing of coal is a young and emerging technology. Until the early 1980's it consisted primarily of coal depyritization using Thiobacillus ferro oxidans to either oxidize pyritic sulfur or to alter particle wettability or floatation properties by binding to exposed pyrite inclusions. Since then, other major avenues of research have been pursued. One of these is the microbiologically mediated liquefaction of coal. Initial work indicated that microorganisms were able to transform low rank coal into a black liquid that was later identified as water solubilized by alkaline substances produced by the microbes and could be enhanced by the removal of multi valent cations from coal. Current work at the INEL involves of the identification and characterization of microorganisms that are able to alter the structure of polymeric desulfurization of coal. This work initially focused on the ability of microorganisms to oxidatively remove organic sulfur from model compounds that were representative of those sulfur containing moieties identified as being in coals (e.g., dibenzo thiophene). The work also focused on those organisms that were could remove the organic sulfur without degrading the carbon structure. While some organisms that are able to perform such these reactions will effectively remove organo sulfur from coal. These concerns stem from steric hindrance considerations and the thermodynamically unfavourable nature of reaction. Current work at the INEL involves the isolation and biochemical characterization of microorganisms that are able to desulfurize and solubilized coals that have high organic sulfur contents. (author)

  10. Desulfurization kinetics of molten copper by gas bubbling

    Science.gov (United States)

    Fukunaka, Y.; Nishikawa, K.; Sohn, H. S.; Asaki, Z.

    1991-02-01

    Molten copper with 0.74 wt pct sulfur content was desulfurized at 1523 K by bubbling Ar-O2 gas through a submerged nozzle. The reaction rate was significantly influenced not only by the oxygen partial pressure but also by the gas flow rate. Little evolution of SO2 gas was observed in the initial 10 seconds of the oxidation; however, this was followed by a period of high evolution rate of SO2 gas. The partial pressure of SO2 gas decreased with further progress of the desulfurization. The effect of the immersion depth of the submerged nozzle was negligible. The overall reaction is decomposed to two elementary reactions: the desulfurization and the dissolution rate of oxygen. The assumptions were made that these reactions are at equilibrium and that the reaction rates are controlled by mass transfer rates within and around the gas bubble. The time variations of sulfur and oxygen contents in the melt and the SO2 partial pressure in the off-gas under various bubbling conditions were well explained by the mathematical model combined with the reported thermodynamic data of these reactions. Based on the present model, it was anticipated that the oxidation rate around a single gas bubble was mainly determined by the rate of gas-phase mass transfer, but all oxygen gas blown into the melt was virtually consumed to the desulfurization and dissolution reactions before it escaped from the melt surface.

  11. Method and apparatus for enhancing the desulfurization of hot coal gas in a fluid-bed coal gasifier

    Science.gov (United States)

    Grindley, T.

    1988-04-05

    A process and apparatus for providing additional desulfurization of the hot gas produced in a fluid-bed coal gasifier, within the gasifier is described. A fluid-bed of iron oxide is located inside the gasifier above the gasification bed in a fluid-bed coal gasifier in which in-bed desulfurization by lime/limestone takes place. The product gases leave the gasification bed typically at 1600 to 1800 F and are partially quenched with water to 1000 to 1200 F before entering the iron oxide bed. The iron oxide bed provides additional desulfurization beyond that provided by the lime /limestone. 1 fig.

  12. Development of high performance ODS alloys

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Lin [Texas A & M Univ., College Station, TX (United States); Gao, Fei [Univ. of Michigan, Ann Arbor, MI (United States); Garner, Frank [Texas A & M Univ., College Station, TX (United States)

    2018-01-29

    This project aims to capitalize on insights developed from recent high-dose self-ion irradiation experiments in order to develop and test the next generation of optimized ODS alloys needed to meet the nuclear community's need for high strength, radiation-tolerant cladding and core components, especially with enhanced resistance to void swelling. Two of these insights are that ferrite grains swell earlier than tempered martensite grains, and oxide dispersions currently produced only in ferrite grains require a high level of uniformity and stability to be successful. An additional insight is that ODS particle stability is dependent on as-yet unidentified compositional combinations of dispersoid and alloy matrix, such as dispersoids are stable in MA957 to doses greater than 200 dpa but dissolve in MA956 at doses less than 200 dpa. These findings focus attention on candidate next-generation alloys which address these concerns. Collaboration with two Japanese groups provides this project with two sets of first-round candidate alloys that have already undergone extensive development and testing for unirradiated properties, but have not yet been evaluated for their irradiation performance. The first set of candidate alloys are dual phase (ferrite + martensite) ODS alloys with oxide particles uniformly distributed in both ferrite and martensite phases. The second set of candidate alloys are ODS alloys containing non-standard dispersoid compositions with controllable oxide particle sizes, phases and interfaces.

  13. Water corrosion resistance of ODS ferritic-martensitic steel tubes

    International Nuclear Information System (INIS)

    Narita, Takeshi; Ukai, Shigeharu; Kaito, Takeji; Ohtsuka, Satoshi; Matsuda, Yasuji

    2008-01-01

    Oxide dispersion strengthened (ODS) ferritic-martensitic steels have superior radiation resistance; it is possible to achieve a service temperature of up to around 973 K because of their superior creep strength. These advantages of ODS steels facilities their application to long-life cladding tubes in advanced fast reactor fuel elements. In addition to neutron radiation resistance, sufficient general corrosion resistance to maintain the strength of the cladding, and the stress corrosion cracking (SCC) resistance for spent-fuel-pool cooling systems and high-temperature oxidation for the fuel-clad chemical interaction (FCCI) of ODS ferritic steel are required. Although the addition of Cr to ODS is effective in preventing water corrosion and high-temperature oxidation, an excessively high amount of Cr leads to embrittlement due to the formation of a Cr-rich α' precipitate. The Cr content in 9Cr-ODS martensite and 12Cr-ODS ferrite, the ODS steels developed by the Japan Atomic Energy Agency (JAEA), is controlled. In a previous paper, it has been demonstrated that the resistances of 9Cr- and 12Cr-ODS ferritic-martensitic steels for high-temperature oxidation are superior to those of conventional 12Cr ferritic steel. However, the water corrosion data of ODS ferritic-martensitic steels are very limited. In this study, a water corrosion test was conducted on ODS steels in consideration of the spent-fuel-pool cooling condition, and the results were compared with those of conventional austenitic stainless steel and ferritic-martensitic stainless steel. (author)

  14. Stack gas desulfurization using adsorbent materials based on copper oxide; Desulfuracion de gases de combustion usando materiales adsorbentes basados en oxido de cobre

    Energy Technology Data Exchange (ETDEWEB)

    Flores Velazquez, Roberto; Rodas Grapain, Arturo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2008-07-01

    One of main fossil fuels used to date in Mexico for power generation is the fuel oil, with a total participation of 32%. The Mexican fuel oil is constituted in average by 84% in weight of carbon, 11% hydrogen, 0.4% nitrogen, 0.2% oxygen, 4% sulfur and the remaining is assumed to be metals such as vanadium, nickel, calcium, magnesium among others. The purpose of the present paper is to show a new route of preparation of materials impregnated through the application of ultrasonic energy and to evaluate its performance in the stack gas desulfurization. [Spanish] Uno de los principales combustibles fosiles empleados actualmente en Mexico para la generacion de energia electrica es el combustoleo, con una participacion total del 32%. El combustoleo mexicano esta constituido en promedio por 84% en peso de carbono, 11% de hidrogeno, 0.4% de nitrogeno, 0.2% de oxigeno, 4% de azufre y el resto se asume a metales como vanadio, niquel, calcio, magnesio entre otros. El proposito del presente trabajo es mostrar una nueva ruta de preparacion de materiales impregnados a traves de la aplicacion de energia ultrasonica y evaluar su desempeno en la desulfuracion de gases de combustion.

  15. Natural desulfurization in coal-fired units using Greek lignite.

    Science.gov (United States)

    Konidaris, Dimitrios N

    2010-10-01

    This paper analyzes the natural desulfurization process taking place in coal-fired units using Greek lignite. The dry scrubbing capability of Greek lignite appears to be extremely high under special conditions, which can make it possible for the units to operate within the legislative limits of sulfur dioxide (SO2) emissions. According to this study on several lignite-fired power stations in northern Greece, it was found that sulfur oxide emissions depend on coal rank, sulfur content, and calorific value. On the other hand, SO2 emission is inversely proportional to the parameter gammaCO2(max), which is equal to the maximum carbon dioxide (CO2) content by volume of dry flue gas under stoichiometric combustion. The desulfurization efficiency is positively correlated to the molar ratio of decomposed calcium carbonate to sulfur and negatively correlated to the free calcium oxide content of fly ash.

  16. THE BIOCATALYTIC DESULFURIZATION PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Scott Collins; David Nunn

    2003-10-01

    The analysis of Petro Star diesel sulfur species is complete and a report is attached. Further analytical efforts will concentrate on characterization of diesel fuel, hydrodesulfurized to varying degrees, in order to determine sulfur species that may be problematic to hydrogen treatment and represent potential target substrates for biodesulfurization in a combined HDS-BDS process. Quotes have been received and are being considered for the partial treatment of Petro Star Inc. marine diesel fuel. Direction of research is changing slightly; economic analysis of the hyphenated--BDSHDS, BDS-CED--has shown the highest probability of success to be with a BDS-HDS process where the biodesulfurization precedes hydrodesulfurization. Thus, the microorganisms will be tailored to focus on those compounds that tend to be recalcitrant to hydrodesulfurization and decrease the severity of the hydrodesulfurization step. A separate, detailed justification for this change is being prepared. Research activities have continued in the characterization of the desulfurization enzymes from multiple sources. Genes for all DszA, -B, -C and -D enzymes (and homologs) have been cloned and expressed. Activity determinations, on a variety of substituted benzothiophene and dibenzothiophene substrates, have been carried out and continue. In addition, chemical synthesis efforts have been carried out to generate additional substrates for analytical standards and activity determinations. The generation of a GSSM mutant library of the ''Rhodococcus IGTS8 dszA'' gene has been completed and development of protocols for a high throughput screen to expand substrate specificity are nearing completion. In an effort to obtain improved hosts as biocatalyst, one hundred-thirty ''Rhodococcus'' and related strains are being evaluated for growth characteristics and other criteria deemed important for an optimal biocatalyst strain. We have also begun an effort to generate

  17. Use of Green Mussel Shell as a Desulfurizer in the Blending of Low Rank Coal-Biomass Briquette Combustion

    Directory of Open Access Journals (Sweden)

    Mahidin Mahidin

    2016-08-01

    Full Text Available Calcium oxide-based material is available abundantly and naturally. A potential resource of that material comes from marine mollusk shell such as clams, scallops, mussels, oysters, winkles and nerites. The CaO-based material has exhibited a good performance as the desulfurizer oradsorbent in coal combustion in order to reduce SO2 emission. In this study, pulverized green mussel shell, without calcination, was utilized as the desulfurizer in the briquette produced from a mixture of low rank coal and palm kernel shell (PKS, also known as bio-briquette. The ratio ofcoal to PKS in the briquette was 90:10 (wt/wt. The influence of green mussel shell contents and combustion temperature were examined to prove the possible use of that materialas a desulfurizer. The ratio of Ca to S (Ca = calcium content in desulfurizer; S = sulfur content in briquette werefixed at 1:1, 1.25:1, 1.5:1, 1.75:1, and 2:1 (mole/mole. The burning (or desulfurization temperature range was 300-500 °C; the reaction time was 720 seconds and the air flow rate was 1.2 L/min. The results showed that green mussel shell can be introduced as a desulfurizer in coal briquette or bio-briquette combustions. The desulfurization process using that desulfurizer exhibited the first order reaction and the highest average efficiency of 84.5%.

  18. HIGH EFFICIENCY DESULFURIZATION OF SYNTHESIS GAS

    Energy Technology Data Exchange (ETDEWEB)

    Anirban Mukherjee; Kwang-Bok Yi; Elizabeth J. Podlaha; Douglas P. Harrison

    2001-11-01

    Mixed metal oxides containing CeO{sub 2} and ZrO{sub 2} are being studied as high temperature desulfurization sorbents capable of achieving the DOE Vision 21 target of 1 ppmv of less H{sub 2}S. The research is justified by recent results in this laboratory that showed that reduced CeO{sub 2}, designated CeO{sub n} (1.5 < n < 2.0), is capable of achieving the 1 ppmv target in highly reducing gas atmospheres. The addition of ZrO{sub 2} has improved the performance of oxidation catalysts and three-way automotive catalysts containing CeO{sub 2}, and should have similar beneficial effects on CeO{sub 2} desulfurization sorbents. An electrochemical method for synthesizing CeO{sub 2}-ZrO{sub 2} has been developed and the products have been characterized by XRD and TEM during year 01. Nanocrystalline particles having a diameter of about 5 nm and containing from approximately 10 mol% to 80 mol% ZrO{sub 2} have been prepared. XRD showed the product to be a solid solution at low ZrO{sub 2} contents with a separate ZrO{sub 2} phase emerging at higher ZrO{sub 2} levels. Phase separation did not occur when the solid solutions were heat treated at 700 C. A flow reactor system constructed of quartz and teflon has been constructed, and a gas chromatograph equipped with a pulsed flame photometric detector (PFPD) suitable for measuring sub-ppmv levels of H{sub 2}S has been purchased with LSU matching funds. Preliminary desulfurization tests using commercial CeO{sub 2} and CeO{sub 2}-ZrO{sub 2} in highly reducing gas compositions has confirmed that CeO{sub 2}-ZrO{sub 2} is more effective than CeO{sub 2} in removing H{sub 2}S. At 700 C the product H{sub 2}S concentration using CeO{sub 2}-ZrO{sub 2} sorbent was near the 0.1 ppmv PFPD detection limit during the prebreakthrough period.

  19. HIGH EFFICIENCY DESULFURIZATION OF SYNTHESIS GAS

    Energy Technology Data Exchange (ETDEWEB)

    Kwang-Bok Yi; Anirban Mukherjee; Elizabeth J. Podlaha; Douglas P. Harrison

    2004-03-01

    Mixed metal oxides containing ceria and zirconia have been studied as high temperature desulfurization sorbents with the objective of achieving the DOE Vision 21 target of 1 ppmv or less H{sub 2}S in the product gas. The research was justified by recent results in this laboratory that showed that reduced CeO{sub 2}, designated CeOn (1.5 < n < 2.0), is capable of achieving the 1 ppmv target in highly reducing gas atmospheres. The addition of ZrO{sub 2} has improved the performance of oxidation catalysts and three-way automotive catalysts containing CeO{sub 2}, and was postulated to have similar beneficial effects on CeO{sub 2} desulfurization sorbents. An electrochemical method for synthesizing CeO{sub 2}-ZrO{sub 2} mixtures was developed and the products were characterized by XRD and TEM during year 01. Nanocrystalline particles having a diameter of about 5 nm and containing from approximately 10 mol% to 80 mol% ZrO{sub 2} were prepared. XRD analysis showed the product to be a solid solution at low ZrO{sub 2} contents with a separate ZrO{sub 2} phase emerging at higher ZrO{sub 2} levels. Unfortunately, the quantity of CeO{sub 2}-ZrO{sub 2} that could be prepared electrochemically was too small to permit desulfurization testing. Also during year 01 a laboratory-scale fixed-bed reactor was constructed for desulfurization testing. All components of the reactor and analytical systems that were exposed to low concentrations of H{sub 2}S were constructed of quartz, Teflon, or silcosteel. Reactor product gas composition as a function of time was determined using a Varian 3800 gas chromatograph equipped with a pulsed flame photometric detector (PFPD) for measuring low H{sub 2}S concentrations from approximately 0.1 to 10 ppmv, and a thermal conductivity detector (TCD) for higher concentrations of H{sub 2}S. Larger quantities of CeO{sub 2}-ZrO{sub 2} mixtures from other sources, including mixtures prepared in this laboratory using a coprecipitation procedure, were obtained

  20. Irradiation response of ODS Eurofer97 steel

    Energy Technology Data Exchange (ETDEWEB)

    Luzginova, N.V., E-mail: luzginova@nrg.eu [Nuclear Research and Consultancy Group, Petten (Netherlands); Nolles, H.S.; Pierick, P. ten; Bakker, T.; Mutnuru, R.K.; Jong, M.; Blagoeva, D.T. [Nuclear Research and Consultancy Group, Petten (Netherlands)

    2012-09-15

    Oxide dispersion strengthened (ODS) Eurofer97 steel (EU batch, 0.3 wt.% of Y{sub 2}O{sub 3} particles), produced by mechanical alloying followed by hot rolling, is irradiated in the High Flux Reactor in Petten, The Netherlands at three different irradiation temperatures (300, 450 and 550 Degree-Sign C) up to nominal doses of 1 dpa and 3 dpa. The effect of neutron irradiation on the mechanical properties of ODS Eurofer97 material is investigated. It is shown that the irradiation hardening of ODS Eurofer97 steel occurs at 300 Degree-Sign C, whereas during irradiation at 450 and 550 Degree-Sign C no changes in mechanical properties are observed compared to the unirradiated material. This effect is possibly a result of the annealing of the irradiation damage at temperatures higher than 300 Degree-Sign C. The observed shifts in the Ductile to Brittle Transition Temperatures due to irradiation at different temperatures are discussed and compared with non-ODS Eurofer97 steel.

  1. A novel semidry flue gas desulfurization process with the magnetically fluidized bed reactor

    International Nuclear Information System (INIS)

    Zhang Qi; Gui Keting

    2009-01-01

    The magnetically fluidized bed (MFB) was used as the reactor in a novel semidry flue gas desulfurization (FGD) process to achieve high desulfurization efficiency. Experiments in a laboratory-scale apparatus were conducted to reveal the effects of approach to adiabatic saturation temperature, Ca/S molar ratio and applied magnetic field intensity on SO 2 removal. Results showed that SO 2 removal efficiency can be obviously enhanced by decreasing approach to adiabatic saturation temperature, increasing Ca/S molar ratio, or increasing applied magnetic field intensity. At a magnetic field intensity of 300 Oe and a Ca/S molar ratio of 1.0, the desulfurization efficiency (excluding desulfurization efficiency in the fabric filter) was over 80%, while spent sorbent appeared in the form of dry powder. With the SEM, XRD and EDX research, it can be found that the increase of DC magnetic field intensity can make the surface morphology on the surface of the ferromagnetic particles loose and enhance the oxidation of S(IV), hence reducing the liquid phase mass transfer resistance of the slurry droplets and increasing desulfurization reaction rate, respectively. Therefore, the desulfurization efficiency increased obviously with the increase of DC field intensity.

  2. Numerical Investigation of Desulfurization Kinetics in Gas-Stirred Ladles by a Quick Modeling Analysis Approach

    Science.gov (United States)

    Cao, Qing; Nastac, Laurentiu; Pitts-Baggett, April; Yu, Qiulin

    2018-03-01

    A quick modeling analysis approach for predicting the slag-steel reaction and desulfurization kinetics in argon gas-stirred ladles has been developed in this study. The model consists of two uncoupled components: (i) a computational fluid dynamics (CFD) model for predicting the fluid flow and the characteristics of slag-steel interface, and (ii) a multicomponent reaction kinetics model for calculating the desulfurization evolution. The steel-slag interfacial area and mass transfer coefficients predicted by the CFD simulation are used as the processing data for the reaction model. Since the desulfurization predictions are uncoupled from the CFD simulation, the computational time of this uncoupled predictive approach is decreased by at least 100 times for each case study when compared with the CFD-reaction kinetics fully coupled model. The uncoupled modeling approach was validated by comparing the evolution of steel and slag compositions with the experimentally measured data during ladle metallurgical furnace (LMF) processing at Nucor Steel Tuscaloosa, Inc. Then, the validated approach was applied to investigate the effects of the initial steel and slag compositions, as well as different types of additions during the refining process on the desulfurization efficiency. The results revealed that the sulfur distribution ratio and the desulfurization reaction can be promoted by making Al and CaO additions during the refining process. It was also shown that by increasing the initial Al content in liquid steel, both Al oxidation and desulfurization rates rapidly increase. In addition, it was found that the variation of the initial Si content in steel has no significant influence on the desulfurization rate. Lastly, if the initial CaO content in slag is increased or the initial Al2O3 content is decreased in the fluid-slag compositional range, the desulfurization rate can be improved significantly during the LMF process.

  3. Numerical Investigation of Desulfurization Kinetics in Gas-Stirred Ladles by a Quick Modeling Analysis Approach

    Science.gov (United States)

    Cao, Qing; Nastac, Laurentiu; Pitts-Baggett, April; Yu, Qiulin

    2018-06-01

    A quick modeling analysis approach for predicting the slag-steel reaction and desulfurization kinetics in argon gas-stirred ladles has been developed in this study. The model consists of two uncoupled components: (i) a computational fluid dynamics (CFD) model for predicting the fluid flow and the characteristics of slag-steel interface, and (ii) a multicomponent reaction kinetics model for calculating the desulfurization evolution. The steel-slag interfacial area and mass transfer coefficients predicted by the CFD simulation are used as the processing data for the reaction model. Since the desulfurization predictions are uncoupled from the CFD simulation, the computational time of this uncoupled predictive approach is decreased by at least 100 times for each case study when compared with the CFD-reaction kinetics fully coupled model. The uncoupled modeling approach was validated by comparing the evolution of steel and slag compositions with the experimentally measured data during ladle metallurgical furnace (LMF) processing at Nucor Steel Tuscaloosa, Inc. Then, the validated approach was applied to investigate the effects of the initial steel and slag compositions, as well as different types of additions during the refining process on the desulfurization efficiency. The results revealed that the sulfur distribution ratio and the desulfurization reaction can be promoted by making Al and CaO additions during the refining process. It was also shown that by increasing the initial Al content in liquid steel, both Al oxidation and desulfurization rates rapidly increase. In addition, it was found that the variation of the initial Si content in steel has no significant influence on the desulfurization rate. Lastly, if the initial CaO content in slag is increased or the initial Al2O3 content is decreased in the fluid-slag compositional range, the desulfurization rate can be improved significantly during the LMF process.

  4. Advanced sulfur control concepts for hot gas desulfurization technology

    International Nuclear Information System (INIS)

    1998-01-01

    The objective of this project is to develop a hot-gas desulfurization process scheme for control of H 2 S in HTHP coal gas that can be more simply and economically integrated with known regenerable sorbents in DOE/METC-sponsored work than current leading hot-gas desulfurization technologies. In addition to being more economical, the process scheme to be developed must yield an elemental sulfur byproduct. The Direct Sulfur Recovery Process (DSRP), a leading process for producing an elemental sulfur byproduct in hot-gas desulfurization systems, incurs a coal gas use penalty, because coal gas is required to reduce the SO 2 in regeneration off-gas to elemental sulfur. Alternative regeneration schemes, which avoid coal gas use and produce elemental sulfur, will be evaluated. These include (i) regeneration of sulfided sorbent using SO 2 ; (ii) partial oxidation of sulfided sorbent in an O 2 starved environment; and (iii) regeneration of sulfided sorbent using steam to produce H 2 S followed by direct oxidation of H 2 S to elemental sulfur. Known regenerable sorbents will be modified to improve the feasibility of the above alternative regeneration approaches. Performance characteristics of the modified sorbents and processes will be obtained through lab- and bench-scale testing. Technical and economic evaluation of the most promising processes concept(s) will be carried out

  5. Peroxide-mediated desulfurization of phosphorothioate oligonucleotides and its prevention.

    Science.gov (United States)

    Krotz, Achim H; Mehta, Rahul C; Hardee, Gregory E

    2005-02-01

    Desulfurization at the internucleotide phosphorothioate linkage of antisense oligonucleotides (ASOs) in dermatological formulations has been investigated using strong ion exchange chromatography and mass spectroscopy. The formation of phosphate diester linkages appeared to arise from a reaction between the phosphorothioate oligonucleotide and a potent oxidizing agent. Screening of excipients used in the formulation indicated that the cause of desulfurization was related to the presence of polyethylene glycol-derived nonionic surfactants MYRJ 52 or BRIJ 58. Autoxidation of the polyethylene glycol chain is suggested as the probable origin for the observed incompatibility. The ability of various antioxidants to prevent oxidative degradation of ASO-1 in simple test systems and in oil-in-water emulsions is described. It is found that in test systems both lipophilic and hydrophilic antioxidants are effective. However, in cream formulation (oil-in-water emulsions) of ASO-1 the addition of hydrophilic antioxidants L-cysteine or DL-alpha-lipoic acid has been shown to be superior in protecting the oligonucleotide from desulfurization upon storage. Copyright 2004 Wiley-Liss, Inc.

  6. Simple biogas desulfurization by microaeration - Full scale experience.

    Science.gov (United States)

    Jeníček, P; Horejš, J; Pokorná-Krayzelová, L; Bindzar, J; Bartáček, J

    2017-08-01

    Hydrogen sulfide in biogas is common problem during anaerobic treatment of wastewater with high sulfate concentration (breweries, distilleries, etc.) and needs to be removed before biogas utilization. Physico-chemical desulfurization methods are energetically demanding and expensive compare to biochemical methods. Microaeration, i.e. dosing of small amount of air, is suitable and cost effective biochemical method of sulfide oxidation to elemental sulfur. It has been widely used in biogas plants, but its application in anaerobic reactors for wastewater treatment has been rarely studied or tested. The lack of full-scale experience with microaeration in wastewater treatment plants has been overcome by evaluating the results of seven microaerobic digesters in central Europe. The desulfurization efficiency has been more than 90% in most of the cases. Moreover, microaeration improved the degradability of COD and volatile suspended solids. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. CONVERSION EXTRACTION DESULFURIZATION (CED) PHASE III

    Energy Technology Data Exchange (ETDEWEB)

    James Boltz

    2005-03-01

    This project was undertaken to refine the Conversion Extraction Desulfurization (CED) technology to efficiently and economically remove sulfur from diesel fuel to levels below 15-ppm. CED is considered a generic term covering all desulfurization processes that involve oxidation and extraction. The CED process first extracts a fraction of the sulfur from the diesel, then selectively oxidizes the remaining sulfur compounds, and finally extracts these oxidized materials. The Department of Energy (DOE) awarded Petro Star Inc. a contract to fund Phase III of the CED process development. Phase III consisted of testing a continuous-flow process, optimization of the process steps, design of a pilot plant, and completion of a market study for licensing the process. Petro Star and the Degussa Corporation in coordination with Koch Modular Process Systems (KMPS) tested six key process steps in a 7.6-centimeter (cm) (3.0-inch) inside diameter (ID) column at gas oil feed rates of 7.8 to 93.3 liters per hour (l/h) (2.1 to 24.6 gallons per hour). The team verified the technical feasibility with respect to hydraulics for each unit operation tested and successfully demonstrated pre-extraction and solvent recovery distillation. Test operations conducted at KMPS demonstrated that the oxidation reaction converted a maximum of 97% of the thiophenes. The CED Process Development Team demonstrated that CED technology is capable of reducing the sulfur content of light atmospheric gas oil from 5,000-ppm to less than 15-ppm within the laboratory scale. In continuous flow trials, the CED process consistently produced fuel with approximately 20-ppm of sulfur. The process economics study calculated an estimated process cost of $5.70 per product barrel. The Kline Company performed a marketing study to evaluate the possibility of licensing the CED technology. Kline concluded that only 13 refineries harbored opportunity for the CED process. The Kline study and the research team's discussions

  8. Flue gas desulfurization: Physicochemical and biotechnological approaches

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, R.A.; Biswas, R.; Chakrabarti, T.; Devotta, S. [National Environmental Engineering Research Institute, Nagpur (India)

    2005-07-01

    Various flue gas desulfurization processes - physicochemical, biological, and chemobiological - for the reduction of emission of SO{sub 2} with recovery of an economic by-product have been reviewed. The physicochemical processes have been categorized as 'once-through' and 'regenerable.' The prominent once-through technologies include wet and dry scrubbing. The wet scrubbing technologies include wet limestone, lime-inhibited oxidation, limestone forced oxidation, and magnesium-enhanced lime and sodium scrubbing. The dry scrubbing constitutes lime spray drying, furnace sorbent injection, economizer sorbent injection, duct sorbent injection, HYPAS sorbent injection, and circulating fluidized bed treatment process. The regenerable wet and dry processes include the Wellman Lord's process, citrate process, sodium carbonate eutectic process, magnesium oxide process, amine process, aqueous ammonia process, Berglau Forchung's process, and Shell's process. Besides these, the recently developed technologies such as the COBRA process, the OSCAR process, and the emerging biotechnological and chemobiological processes are also discussed. A detailed outline of the chemistry, the advantages and disadvantages, and the future research and development needs for each of these commercially viable processes is also discussed.

  9. Fatigue characteristics of ODS surface treated Zircaloy-4

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sun Han; Jung, Yan gIl; Park, Dong Jun; Park, Jung Hwan; Kim, Hyun Gil; Yang, Jae Ho; Koo, Yang Hyun [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    Various accident tolerant fuel (ATF) cladding concepts are considered and have being developed to increase the oxidation resistance and ballooning/ rupture resistance of current Zr-based cladding material under accident conditions. One concept is to form an oxidation-resistant layer on Zr cladding surface. The other is to increase high temperature mechanical strength of Zr tube. The oxide dispersion strengthened (ODS) zirconium was proposed to increase the strength of the Zr-based alloy up to high temperatures. ODS treatment is a way of improve the high temperature- oxidation resistant and mechanical stress by disperse the hardened particles inside of metal to interrupt the movement of the electric potential. In this study, the accident tolerance improved zirconium alloy by the ODS surface treatment was evaluated for the fatigue characteristics which is one of the significant items of the integrity assessment.

  10. Effect of Silicon on Desulfurization of Aluminum-killed Steels

    Science.gov (United States)

    Roy, Debdutta

    Recent reports have suggested that silicon has a beneficial effect on the rate of desulfurization of Al-killed steel. This effect is difficult to understand looking at the overall desulfurization reaction which does not include silicon. However an explanation is proposed by taking into account the (SiO2)/[Si] equilibrium in which some Al reaching the slag-metal interface is used in reducing the SiO2 in the slag. This reaction can be suppressed to some extent if the silicon content of the metal is increased and in doing so, more Al will be available at the slag-metal interface for the desulfurization reaction and this would increase the rate of the desulfurization reaction. A model was developed, assuming the rates are controlled by mass transfer, taking into account the coupled reactions of the reduction of silica, and other unstable oxides, namely iron oxide and manganese oxide, in the slag and desulfurization reaction in the steel by aluminum. The model predicts that increasing silicon increases the rate and extent of desulfurization. Plant data was analyzed to obtain rough estimates of ladle desulfurization rates and also used to validate the model predictions. Experiments have been conducted on a kilogram scale of material in an induction furnace to test the hypothesis. The major conclusions of the study are as follows: The rate and extent of desulfurization improve with increasing initial silicon content in the steel; the effect diminishes at silicon contents higher than approximately 0.2% and with increasing slag basicity. This was confirmed with kilogram-scale laboratory experiments. The effects of the silicon content in the steel (and of initial FeO and MnO in the slag) largely arise from the dominant effects of these reactions on the equilibrium aluminum content of the steel: as far as aluminum consumption or pick-up is concerned, the Si/SiO2 reaction dominates, and desulfurization has only a minor effect on aluminum consumption. The rate is primarily

  11. High yttria ferritic ODS steels through powder forging

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Deepak [Department of Metallurgical and Materials Engineering, I.I.T-Roorkee, Uttarakhand 247667 (India); Prakash, Ujjwal, E-mail: ujwalfmt@iitr.ac.in [Department of Metallurgical and Materials Engineering, I.I.T-Roorkee, Uttarakhand 247667 (India); Dabhade, Vikram V. [Department of Metallurgical and Materials Engineering, I.I.T-Roorkee, Uttarakhand 247667 (India); Laha, K.; Sakthivel, T. [Mechanical Metallurgy Group, IGCAR, Kalpakkam, Tamilnadu 603102 (India)

    2017-05-15

    Oxide dispersion strengthened (ODS) steels are being developed for future nuclear reactors. ODS Fe-18%Cr-2%W-0.2%Ti steels with 0, 0.35, 0.5, 1 and 1.5% Y{sub 2}O{sub 3} (all compositions in weight%) dispersion were fabricated by mechanical alloying of elemental powders. The powders were placed in a mild steel can and forged in a stream of hydrogen gas at 1473 K. The steels were forged again to final density. The strength of ODS steel increased with yttria content. Though this was accompanied by a decrease in tensile elongation, all the steels showed significant ductility. The ductility in high yttria alloys may be attributed to improved inter-particle bonding between milled powders due to reduction of surface oxides by hydrogen. This may permit development of ODS steels with yttria contents higher than the conventional limit of 0.5%. It is suggested that powder forging is a promising route to fabricate ODS steels with high yttria contents and improved ductility. - Highlights: •ODS steels with yttria contents beyond the conventional limit of 0.5 wt% were fabricated by powder forging in a hydrogen atmosphere. •All the alloys exhibited significant ductility. •This may be attributed to improved inter-particle bonding due to reduction of surface oxides by hydrogen. •Strength in excess of 300 MPa was obtained at 973 K for 0.5%, 1% and 1.5% yttria ODS alloys. •Powder forging is a promising route to fabricate ODS steels and permits development of compositions with up to 1.5% yttria.

  12. TEM characterization of simultaneous triple ion implanted ODS Fe12Cr

    International Nuclear Information System (INIS)

    Castro, Vanessa de; Briceno, Martha; Lozano-Perez, Sergio; Trocellier, Patrick; Roberts, Steve G.; Pareja, Ramiro

    2014-01-01

    Understanding the behavior of oxide dispersion strengthened (ODS) ferritic/martensitic steels under irradiation is vital in the design of advanced fusion reactors. In this work, a simultaneous triple ion implanted ODS Fe12Cr steel was investigated by transmission electron microscopy in order to determine the effect of irradiation on the grain and dislocation structures, oxide nanoparticles and other secondary phases present in the steel. The ODS steel was irradiated at RT with Fe 8+ , He + and H + at the JANNUS-Saclay facility to a damage of 4.4 dpa. Results show that ODS nanoparticles appear very stable under these irradiation conditions

  13. TEM characterization of simultaneous triple ion implanted ODS Fe12Cr

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Vanessa de, E-mail: vanessa.decastro@uc3m.es [Departamento de Física, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911 Leganés, Madrid (Spain); Briceno, Martha [Department of Materials, University of Oxford, Oxford OX1 3PH (United Kingdom); Johnson Matthey Technology Centre, Blount’s Court Rd, Sonning Common RG4 9NH (United Kingdom); Lozano-Perez, Sergio [Department of Materials, University of Oxford, Oxford OX1 3PH (United Kingdom); Trocellier, Patrick [CEA, DEN, Service de Recherches de Métallurgie Physique, Laboratoire JANNUS, F-91191 Gif-sur-Yvette (France); Roberts, Steve G. [Department of Materials, University of Oxford, Oxford OX1 3PH (United Kingdom); Pareja, Ramiro [Departamento de Física, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911 Leganés, Madrid (Spain)

    2014-12-15

    Understanding the behavior of oxide dispersion strengthened (ODS) ferritic/martensitic steels under irradiation is vital in the design of advanced fusion reactors. In this work, a simultaneous triple ion implanted ODS Fe12Cr steel was investigated by transmission electron microscopy in order to determine the effect of irradiation on the grain and dislocation structures, oxide nanoparticles and other secondary phases present in the steel. The ODS steel was irradiated at RT with Fe{sup 8+}, He{sup +} and H{sup +} at the JANNUS-Saclay facility to a damage of 4.4 dpa. Results show that ODS nanoparticles appear very stable under these irradiation conditions.

  14. Desulfurization sorbent regeneration

    Science.gov (United States)

    Jalan, V.M.; Frost, D.G.

    1982-07-07

    A spent solid sorbent resulting from the removal of hydrogen sulfide from a fuel gas flow is regenerated with a steam-air mixture. The mixture of steam and air may also include additional nitrogen or carbon dioxide. The gas mixture contacts the spent sorbent containing metal sulfide at a temperature above 500/sup 0/C to regenerate the sulfide to metal oxide or carbonate. Various metal species including the period four transition metals and the lanthanides are suitable sorbents that may be regenerated by this method. In addition, the introduction of carbon dioxide gas permits carbonates such as those of strontium, barium and calcium to be regenerated. The steam permits regeneration of spent sorbent without formation of metal sulfate. Moreover, the regeneration will proceed with low oxygen concentrations and will occur without the increase in temperature to minimize the risk of sintering and densification of the sorbent. This method may be used for high-temperature fuel cells.

  15. Inhibited Aluminization of an ODS FeCr Alloy

    International Nuclear Information System (INIS)

    Vande Put Ep Rouaix, Aurelie; Pint, Bruce A.

    2012-01-01

    Aluminide coatings are of interest for fusion energy applications both for compatibility with liquid Pb-Li and to form an alumina layer that acts as a tritium permeation barrier. Oxide dispersion strengthened (ODS) ferritic steels are a structural material candidate for commercial reactor concepts expected to operate above 600 C. Aluminizing was conducted in a laboratory scale chemical vapor deposition reactor using accepted conditions for coating Fe- and Ni-base alloys. However, the measured mass gains on the current batch of ODS Fe-14Cr were extremely low compared to other conventional and ODS alloys. After aluminizing at two different Al activities at 900 C and at 1100 C, characterization showed that the ODS Fe-14Cr specimens formed a dense, primarily AlN layer that prevented Al uptake. This alloy batch contained a higher (> 5000 ppma) N content than the other alloys coated and this is the most likely reason for the inhibited aluminization. Other factors such as the high O content, small (∼ 140 nm) grain size and Y-Ti oxide nano-clusters in ODS Fe-14Cr also could have contributed to the observed behavior. Examples of typical aluminide coatings formed on conventional and ODS Fe- and Ni-base alloys are shown for comparison.

  16. THE BIOCATALYTIC DESULFURIZATION PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Steven E. Bonde; David Nunn

    2003-04-01

    Research activities in the second quarter have largely been a continuation of efforts previously described in the first quarterly report as well as a degree of redirection of effort as a result of discussions during the first quarterly meeting held in San Diego. Chemical synthesis efforts have been refined and are currently being used to support generation of substrates for evaluation and evolution of enzymes for their oxidation. Analysis of the sulfur species in Petro Star diesel, CED extract and refinement of the speciation data is nearly complete. Molecular biology efforts continue with the cloning, expression and characterization of the DszA and DszC proteins as well as the flavin reductases to support regeneration of the essential FMN cofactors. In addition, we have initiated an evolution effort for the extension and improvement of DszA enzyme activity using Diversa's Gene Site Saturation Mutagenesis (GSSM{trademark}) technology. To support the evolution effort as well as of characterization of enzyme activities on a variety of substrates, a high-throughput mass spectroscopy-based assay has been developed. Two selection/screen strategies for the discovery and evolution of biocatalyst enzyme have been developed and are being evaluated for performance using gene libraries constructed from known biodesulfurization strains and environmental libraries.

  17. Void formation in ODS EUROFER produced by hot isostatic pressing

    International Nuclear Information System (INIS)

    Ortega, Y.; Monge, M.A.; Castro, V. de; Munoz, A.; Leguey, T.; Pareja, R.

    2009-01-01

    Positron annihilation experiments were performed on oxide dispersion strengthened (ODS) and non-ODS EUROFER prepared by mechanical alloying and hot isostatic pressing. The results revealed the presence of small voids in these materials in the as-HIPed conditions. Their evolution under isochronal annealing experiments was investigated. The coincidence Doppler broadening spectra of ODS EUROFER exhibited a characteristic signature attributed to positron annihilation in Ar-decorated voids at the oxide particle/matrix interfaces. The variation of the positron annihilation parameters with the annealing temperature showed three stages: up to 623 K, between 823 and 1323 K, and above 1323 K. In the temperature range 823-1323 K void coarsening had effect. Above 1323 K some voids annealed out, but others, associated to oxide particles and small precipitates, survived to annealing at 1523 K. Transmission electron microscopy observations were also performed to verify the characteristics of the surviving defects after annealing at 1523 K.

  18. Void formation in ODS EUROFER produced by hot isostatic pressing

    Energy Technology Data Exchange (ETDEWEB)

    Ortega, Y. [Departamento de Fisica, Universidad Carlos III de Madrid, 28911 Leganes (Spain)], E-mail: yanicet@fis.ucm.es; Monge, M.A. [Departamento de Fisica, Universidad Carlos III de Madrid, 28911 Leganes (Spain); Castro, V. de [Department of Materials, University of Oxford, Oxford OX1 3PH (United Kingdom); Munoz, A.; Leguey, T.; Pareja, R. [Departamento de Fisica, Universidad Carlos III de Madrid, 28911 Leganes (Spain)

    2009-04-30

    Positron annihilation experiments were performed on oxide dispersion strengthened (ODS) and non-ODS EUROFER prepared by mechanical alloying and hot isostatic pressing. The results revealed the presence of small voids in these materials in the as-HIPed conditions. Their evolution under isochronal annealing experiments was investigated. The coincidence Doppler broadening spectra of ODS EUROFER exhibited a characteristic signature attributed to positron annihilation in Ar-decorated voids at the oxide particle/matrix interfaces. The variation of the positron annihilation parameters with the annealing temperature showed three stages: up to 623 K, between 823 and 1323 K, and above 1323 K. In the temperature range 823-1323 K void coarsening had effect. Above 1323 K some voids annealed out, but others, associated to oxide particles and small precipitates, survived to annealing at 1523 K. Transmission electron microscopy observations were also performed to verify the characteristics of the surviving defects after annealing at 1523 K.

  19. Oxidative desulfurization of diesel by potato based-carbon as green support for H5PMo10V2O40: Efficient composite nanorod catalyst

    Directory of Open Access Journals (Sweden)

    Ezzat Rafiee

    2017-07-01

    Full Text Available The C@POM (carbon@polyoxometalate containing H3PMo12O40 (PMo12, H5PMo10V2O40 (PMo10V2, H6PMo9V3O40 (PMo9V3, H7PMo8V4O40 (PMo8V4, H3PW12O40 (PW, and H4SiW12O40 (SiW were prepared from natural potato as green, and cheap catalyst support source. The C@PMo10V2 was found to be a unique, effective, and eco-friendly catalyst for selective oxidation of sulfides, using 30% aq. H2O2. C@PMo10V2 composite was characterized by X-ray diffraction spectroscopy (XRD, energy dispersive X-ray spectroscopy (EDX, scanning electron microscopy (SEM, thermal gravimetric analysis (TGA, Fourier transform infrared (FT-IR spectrophotometry, zeta sizer, and zeta potential. The XRD results show that during immobilization PMo10V2 on the carbon catalyst support (CCS, the crystallite structure of PMo10V2 and CCS was not changed. The SEM results show that PMo10V2 crystals deposited on the surface CCS rods as composite nanorod structure. A variety of sulfides, sulfur-containing model and real oil were oxidized with the C@PMo10V2/H2O2 at room temperature. Recovered catalyst show excellent activity for at least four repeating cycles.

  20. Effect of zirconium addition on the microstructure and mechanical properties of ODS ferritic steels containing aluminum

    International Nuclear Information System (INIS)

    Gao, R.; Zhang, T.; Wang, X.P.; Fang, Q.F.; Liu, C.S.

    2014-01-01

    The oxide dispersion strengthened (ODS) ferritic steels with nominal composition of Fe–16Cr–2W–0.5Ti–0.4Y 2 O 3 –4Al–1Zr (16Cr–4Al–Zr–ODS) were fabricated by a sol–gel method combining with mechanical alloying and spark plasma sintering (SPS) technique, and the 16Cr–ODS and 16Cr–4Al–ODS steels were prepared for comparison in the same way. Microstructure characterization reveals that in the 16Cr–4Al–ODS steel coarse Y–Al–O particles were formed while in the 16Cr–4Al–Zr–ODS steel finer Y–Zr–O particles were formed. The mean size and number density of the nano-oxide particles in the 16Cr–4Al–Zr–ODS steel are about 25 nm and 2.6 × 10 21 /m 3 , respectively. The ultimate tensile strength (UTS) of the 16Cr–ODS steel is about 1045 MPa, but UTS of the 16Cr–4Al–ODS steel decreases to 974 MPa. However, UTS of the 16Cr–4Al–Zr–ODS steel increases to 1180 MPa while keeping a large uniform elongation up to 23%, indicating the enhancement of mechanical properties by Zr addition

  1. Microstructural stability of 11Cr ODS steel

    Energy Technology Data Exchange (ETDEWEB)

    Yamashiro, Tetsuya, E-mail: fgsjkr@eng.hokudai.ac.jp [Materials Science and Engineering, Graduate School of Engineering, Hokkaido University, N13, W-8, Kita-ku, Sapporo 060-8628 (Japan); Ukai, Shigeharu; Oono, Naoko [Materials Science and Engineering, Faculty of Engineering, Hokkaido University, N13, W-8, Kita-ku, Sapporo 060-8628 (Japan); Ohtsuka, Satoshi; Kaito, Takeji [Advanced Nuclear System R& D Directorate, Japan Atomic Energy Agency (JAEA), 4002, Narita, Oarai, Ibaraki-pref. 311-1393 (Japan)

    2016-04-15

    Aiming at further improvement of high-temperature oxidation and corrosion resistance, 11CrODS steel with martensitic base structure has been previously developed, as a candidate fuel cladding material for 4th generation advanced nuclear reactors. In this study, the microstructure of 11CrODS steel was characterized by means of EBSD and nanoindentation hardness measurement. The continuous cooling transformation (CCT) diagram was constructed. Upper critical cooling rate, which is minimum cooling rate necessary to form martensitic structure, was derived to be 60 °C/min (3600 °C/h). In contrast, lower critical cooling rate preventing from martensite formation, was derived to be 10 °C/min (600 °C/h). An area fraction of so called residual ferrite was estimated by image processing of EBSD-IQ map to be 21% of the total area. This fraction of the residual ferrite in 11CrODS steel was evaluated by considering the driving force for α to γ reverse transformation.

  2. Review of desulfurization process for biogas purification

    Science.gov (United States)

    Xiao, Cong; Ma, Yunqian; Ji, Dandan; Zang, Lihua

    2017-12-01

    Hydrogen sulfide (H2S) is a toxic and odorous compound present in biogas produced by the anaerobic digestion of biosolids and other organic materials. Elimination of H2S is necessary as it is extremely hazardous to human health, poisonous to process catalysts and corrosive to equipment. The desulfurization technology is an important part for efficient utilization of biogas. In this paper, the traditional wet and dry desulfurization technology for biogas was reviewed, and the new research progress of biological desulfurization technologies are also introduced.

  3. Effect of TMP variables upon structure and properties in ODS alloy HDA 8077 sheet. [ThermoMechanical Processing of Oxide Dispersion Strengthened nickel alloy

    Science.gov (United States)

    Rothman, M. F.; Tawancy, H. M.

    1980-01-01

    The effects of oxide content level and variations in thermomechanical processing upon the final structure and properties of HDA 8077 sheet have been systematically examined. It was found that creep strength and formability are substantially influenced by both oxide content and TMP schedule. Variations in creep properties obtained appear to correlate with observed microstructures.

  4. Desulfurization of organic sulfur from a subbituminous coal by electron-transfer process with K{sub 4}(Fe(CN){sub 6})

    Energy Technology Data Exchange (ETDEWEB)

    Dipu Borah [Pragjyotika J College, Titabar (India). Department of Chemistry

    2006-02-01

    The desulfurization reaction involving direct electron transfer from potassium ferrocyanide, K{sub 4}(Fe(CN){sub 6}), successfully removed organic sulfur from a subbituminous coal. The temperature variation of desulfurization revealed that increase of temperature enhanced the level of sulfur removal. Moreover, the desulfurization reaction was found to be dependent on the concentration of K{sub 4}(Fe(CN){sub 6}). Gradual increase in the concentration of K{sub 4}(Fe(CN){sub 6}) raised the magnitude of desulfurization, but at higher concentration the variation was not significant. The removal of organic sulfur from unoxidized coal slightly increased with reduced particle size. Desulfurization from oxidized coals (prepared by aerial oxidation) revealed a higher level of sulfur removal in comparison to unoxidized coal. Highest desulfurization of 36.4 wt % was obtained at 90{sup o}C and 0.1 M concentration of K{sub 4}(Fe(CN){sub 6}) in the 100-mesh size oxidized coal prepared at 200{sup o}C. Model sulfur compound study revealed that aliphatic types of sulfur compounds are primarily responsible for desulfurization. Because of higher stability, thiophene and condensed thiophene-type of compounds perhaps remained unaffected by the electron-transfer agent. Infrared study revealed the formation of oxidized sulfur compounds (sulfoxide, sulfone, sulfonic acid, etc.) in the oxidized coals. The desulfurization reaction in different systems is well-represented by the pseudo-first-order kinetic model. Application of the transition state theory indicated that the desulfurization reaction proceeds with the absorption of heat (endothermic reaction) and is nonspontaneous in nature. 53 refs., 6 figs., 3 tabs.

  5. Positron annihilation characteristics of ODS and non-ODS EUROFER isochronally annealed

    International Nuclear Information System (INIS)

    Ortega, Y.; Castro, V. de; Monge, M.A.; Munoz, A.; Leguey, T.; Pareja, R.

    2008-01-01

    Yttrium oxide dispersion strengthened (ODS) and non-ODS EUROFER produced by mechanical alloying and hot isostatic pressing have been subjected to isochronal annealing up to 1523 K, and the evolution of the open-volume defects and their thermal stability have been investigated using positron lifetime and coincidence Doppler broadening (CDB) techniques. Transmission electron microscopy (TEM) observations have also been performed on the studied samples to verify the characteristics of the surviving defects after annealing at 1523 K. The CDB spectra of ODS EUROFER exhibit a characteristic signature that is attributed to positron annihilation in Ar-decorated cavities at the oxide particle/matrix interfaces. The variation of the positron annihilation parameters with the annealing temperature shows three stages: up to 623 K, between 823 and 1323 K, and above 1323 K. Three-dimensional vacancy clusters, or voids, are detected in either materials in as-HIPed condition and after annealing at T ≤ 623 K. In the temperature range 823-1323 K, these voids' growth and nucleation and the growth of other new species of voids take place. Above 1323 K, some unstable cavities start to anneal out, and cavities associated to oxide particles and other small precipitates survive to annealing at 1523 K. The TEM observations and the positron annihilation results indicate that these cavities should be decorated with Ar atoms absorbed during the mechanical alloying process

  6. Positron annihilation characteristics of ODS and non-ODS EUROFER isochronally annealed

    Energy Technology Data Exchange (ETDEWEB)

    Ortega, Y. [Departamento de Fisica, Universidad Carlos III de Madrid, 28911 Leganes (Spain)], E-mail: yanicet@fis.ucm.es; Castro, V. de; Monge, M.A.; Munoz, A.; Leguey, T.; Pareja, R. [Departamento de Fisica, Universidad Carlos III de Madrid, 28911 Leganes (Spain)

    2008-05-31

    Yttrium oxide dispersion strengthened (ODS) and non-ODS EUROFER produced by mechanical alloying and hot isostatic pressing have been subjected to isochronal annealing up to 1523 K, and the evolution of the open-volume defects and their thermal stability have been investigated using positron lifetime and coincidence Doppler broadening (CDB) techniques. Transmission electron microscopy (TEM) observations have also been performed on the studied samples to verify the characteristics of the surviving defects after annealing at 1523 K. The CDB spectra of ODS EUROFER exhibit a characteristic signature that is attributed to positron annihilation in Ar-decorated cavities at the oxide particle/matrix interfaces. The variation of the positron annihilation parameters with the annealing temperature shows three stages: up to 623 K, between 823 and 1323 K, and above 1323 K. Three-dimensional vacancy clusters, or voids, are detected in either materials in as-HIPed condition and after annealing at T {<=} 623 K. In the temperature range 823-1323 K, these voids' growth and nucleation and the growth of other new species of voids take place. Above 1323 K, some unstable cavities start to anneal out, and cavities associated to oxide particles and other small precipitates survive to annealing at 1523 K. The TEM observations and the positron annihilation results indicate that these cavities should be decorated with Ar atoms absorbed during the mechanical alloying process.

  7. Ozone-depleting Substances (ODS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — This site includes all of the ozone-depleting substances (ODS) recognized by the Montreal Protocol. The data include ozone depletion potentials (ODP), global warming...

  8. Desulfurization technology in the blast furnace raceway by MgO-SiO{sub 2} flux injection

    Energy Technology Data Exchange (ETDEWEB)

    Orimoto, T.; Noda, T.; Ichida, M.; Nagasaka, T. [Hokkai Iron & Coke Corporation, Hokkaido (Japan)

    2008-07-01

    This paper presents a study on desulfurization technology in the steel industry, with attention focused on the removal of sulfur that forms acid rain, which has been creating various global problems. The study was confined to the technology that injects a mixture of serpentine and pulverized coals. Thermodynamically, a magnesium gas producing reaction occurs when magnesium oxide is turned into a hot strongly reducing atmosphere and the resulting magnesium gas forms magnesium sulfide by reaction with the sulfur in the molten iron. By dividing this desulfurization process into a magnesium gas producing reaction and a desulfurization reaction by the magnesium gas, the desulfurization effect of the magnesium oxide flux was confirmed through laboratory experiment. A thermodynamic study on the desulfurization reaction in which SiO gas resulting from the reduction of SiO{sub 2} produces a silicon sulfide gas by reaction with the sulfur in the molten iron revealed that the possibility of desulfurization of the molten iron by the silicon sulfide gas is not negligible.

  9. Simultaneous desulfurization and denitrification by microwave reactor with ammonium bicarbonate and zeolite

    Energy Technology Data Exchange (ETDEWEB)

    Wei Zaishan [School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275 (China)], E-mail: weizaishan98@163.com; Lin Zhehang; Niu Hejingying; He Haiming; Ji Yongfeng [School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275 (China)

    2009-03-15

    Microwave reactor with ammonium bicarbonate (NH{sub 4}HCO{sub 3}) and zeolite was set up to study the simultaneous removal of sulfur dioxide (SO{sub 2}) and nitrogen oxides (NO{sub x}) from flue gas. The results showed that the microwave reactor filled with NH{sub 4}HCO{sub 3} and zeolite could reduce SO{sub 2} to sulfur with the best desulfurization efficiency of 99.1% and reduce NO{sub x} to nitrogen with the best NO{sub x} purifying efficiency of 86.5%. Microwave desulfurization and denitrification effect of the experiment using ammonium bicarbonate and zeolite together is much higher than that using ammonium bicarbonate or zeolite only. NO{sub x} concentration has little effect on denitrification but has no influence on desulfurization, SO{sub 2} concentration has no effect on denitrification. The optimal microwave power and empty bed residence time (EBRT) on simultaneous desulfurization and dentrification are 211-280 W and 0.315 s, respectively. The mechanism for microwave reduced desulfurization and denitrification can be described as the microwave-induced catalytic reduction reaction between SO{sub 2}, NO{sub x} and ammonium bicarbonate with zeolite being the catalyst and microwave absorbent.

  10. Radiation-induced desulfurization of Arabian crude oil and straight-run diesel

    International Nuclear Information System (INIS)

    Basfar, A.A.; Mohamed, K.A.

    2011-01-01

    Radiation-induced desulfurization of four types of Arabian crude oils (heavy, medium, light and extra light) and straight-run diesel (SRD) was investigated over the range of 10-200 kGy. Results show that gamma radiation processing at absorbed doses up to 200 kGy without further treatment is not sufficient for desulfurization. However, the combination of gamma-irradiation with other physical/chemical processes (i.e. L/L extraction, adsorption and oxidation) may be capable of removing considerable levels of sulfur compounds in the investigated products. Currently, this approach of combined radiation/physical/chemical processes is under investigation. The findings of these attempts will be reported in the future. - Highlights: → Irradiation effect on desulfurization in Arabian crude oils and straight-run diesel was investigated. → No noticeable changes in sulfur content after irradiation up to 200 kGy were observed. → Stricter regulations on sulfur levels in fuels motivate search for improved desulfurization processes. → Limited investigations on radiation-induced desulfurization of oil products are conducted.

  11. Simultaneous desulfurization and denitrification by microwave reactor with ammonium bicarbonate and zeolite

    International Nuclear Information System (INIS)

    Wei Zaishan; Lin Zhehang; Niu Hejingying; He Haiming; Ji Yongfeng

    2009-01-01

    Microwave reactor with ammonium bicarbonate (NH 4 HCO 3 ) and zeolite was set up to study the simultaneous removal of sulfur dioxide (SO 2 ) and nitrogen oxides (NO x ) from flue gas. The results showed that the microwave reactor filled with NH 4 HCO 3 and zeolite could reduce SO 2 to sulfur with the best desulfurization efficiency of 99.1% and reduce NO x to nitrogen with the best NO x purifying efficiency of 86.5%. Microwave desulfurization and denitrification effect of the experiment using ammonium bicarbonate and zeolite together is much higher than that using ammonium bicarbonate or zeolite only. NO x concentration has little effect on denitrification but has no influence on desulfurization, SO 2 concentration has no effect on denitrification. The optimal microwave power and empty bed residence time (EBRT) on simultaneous desulfurization and dentrification are 211-280 W and 0.315 s, respectively. The mechanism for microwave reduced desulfurization and denitrification can be described as the microwave-induced catalytic reduction reaction between SO 2 , NO x and ammonium bicarbonate with zeolite being the catalyst and microwave absorbent

  12. Effects of Zr Addition on Strengthening Mechanisms of Al-Alloyed High-Cr ODS Steels.

    Science.gov (United States)

    Ren, Jian; Yu, Liming; Liu, Yongchang; Liu, Chenxi; Li, Huijun; Wu, Jiefeng

    2018-01-12

    Oxide dispersion strengthened (ODS) steels with different contents of zirconium (denoted as 16Cr ODS, 16Cr-0.3Zr ODS and 16Cr-0.6Zr ODS) were fabricated to investigate the effects of Zr on strengthening mechanism of Al-alloyed 16Cr ODS steel. Electron backscatter diffraction (EBSD) results show that the mean grain size of ODS steels could be decreased by Zr addition. Transmission electron microscope (TEM) results indicate that Zr addition could increase the number density but decrease the mean diameter and inter-particle spacing of oxide particles. Furthermore, it is also found that in addition to Y-Al-O nanoparticles, Y-Zr-O oxides with finer size were observed in 16Cr-0.3Zr ODS and 16Cr-0.6Zr ODS steels. These changes in microstructure significantly increase the yield strength (YS) and ultimate tensile strength (UTS) of ODS steels through mechanisms of grain boundary strengthening and dispersion strengthening.

  13. Modification of the Strength Anisotropy in an Austenitic ODS Steel

    International Nuclear Information System (INIS)

    Kim, T. K.; Jang, J.; Kim, S. H.; Lee, C. B.; Bae, C. S.; Kim, D. H.

    2007-01-01

    Among many candidate alloys for Gen IV reactors, the oxide dispersion strengthened (ODS) alloy is widely considered as a good candidate material for the in-reactor component, like cladding tube. The ODS alloy is well known due to its good high temperature strength, and excellent irradiation resistance. For the previous two decades in the nuclear community, the ODS alloy developments have been mostly focused on the ferritic martensitic (F-M) steel-based ones. On the other hand, the austenitic stainless steels (e.g. 316L or 316LN) have been used as a structural material due to its good high temperature strength and a good compatibility with a media. However, the austenitic stainless steel showed unfavorable characteristics in the dimensional stability under neutron irradiation and cracking behavior with the media. It is thus expected that the austenitic ODS steels restrain the dimension stability under neutron irradiation. However, the ODS alloys usually reveal the anisotropic characteristic in mechanical strength in the hoop and longitudinal directions, which is attributed to the grain morphology strongly developed parallel to the rolling direction with a high aspect ratio. This study focuses on a modification of the strength anisotropy of an austenitic ODS alloy by a recrystallization heat treatment

  14. Process for desulfurizing shale oil, etc

    Energy Technology Data Exchange (ETDEWEB)

    Escherich, F

    1922-12-17

    A process is described for the desulfurizing of shale oil or tar, with recovery of valuable oils and hydrocarbons, characterized in that the raw material is heated in an autoclave to a pressure of 100 atmospheres or more.

  15. Biocatalytic desulfurization of petroleum and middle distillates

    International Nuclear Information System (INIS)

    Monticello, D.J.

    1993-01-01

    Biocatalytic Desulfurization (BDS) represents an alternative approach to the reduction of sulfur in fossil fuels. The objective is to use bacteria to selectively remove sulfur from petroleum and middle distillate fractions, without the concomitant release of carbon. Recently, bacteria have been developed which have the ability to desulfurize dibenzothiophene (DBT) and other organosulfur molecules. These bacteria are being developed for use in a biocatalyst-based desulfurization process. Analysis of preliminary conceptual engineering designs has shown that this process has the potential to complement conventional technology as a method to temper the sulfur levels in crude oil, or remove the recalcitrant sulfur in middle distillates to achieve the deep desulfurization mandated by State and Federal regulations. This paper describes the results of initial feasibility studies, sensitivity analyses and conceptual design work. Feasibility studies with various crude oils and middle distillates achieved unoptimized desulfurization levels of 40-80%. Sensitivity analyses indicate that total desulfurization costs of about $3.00 per barrel for crude oil and less than $2.00 per barrel for diesel are possible. Key criteria for commercial success of the process include the cost and half-life of the biocatalyst, residence time in the reactor, oil/water ratios required to extract the sulfur and the disposition of the separated sulfur products. 9 refs., 3 figs

  16. Od psihoterapije do utopije

    Directory of Open Access Journals (Sweden)

    Josip Ćirić

    2015-06-01

    -metodu, Milgram (Obedience to Authority 30-31 skupio je procjene stručnjaka i nestručnjaka o očekivanu ponašanju ispitanika i one su pokazale zapanjujuću razliku naspram empirijskih ishoda – procijenjeno je da će 0,1% ispitanika elektrošokove zadavati do kraja, dok su ispitivanja pokazala da taj postotak raste do 65% (33. Logički biheviorizam u filozofiji znanosti, problem odnosa um-tijelo (za detaljnu sistematizaciju logičkog prostora ovog problema vidi Ludwig 10-11 ili pitanja vezana uz umjetnu inteligenciju u filozofiji uma samo su neke od ilustracija utjecaja filozofskih teorija na psihologiju. Fokus je našeg istraživanja na politikama koje proizlaze iz psihoterapijske teorije i prelaženju granica koje postavlja znanstveni diskurs.

  17. Microstructure and mechanical properties of friction stir welded 9Cr ODS steel

    International Nuclear Information System (INIS)

    Min, Hyoung Kee; Kang, Suk Hoon; Noh, Sanghoon; Lee, Jung Gu; Jang, Jinsung; Kim, Tae Kyu

    2013-01-01

    It is well known that the welding of ODS steel with a conventional melting.solidification process is not adequate to reserve nano-oxide particles in the matrix homogeneously. To reserve nano-oxide particles in the matrix homogeneously, friction stir welding (FSW) is the most promising technique to join ODS alloys. In this study, the effects of FSW on the microstructure and mechanical properties of a ODS steel were studied to apply the FSW process to 9Cr ODS steels. Microstructures were observed by means of optical microscopy, electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). A tensile test and hardness test were carried out to the investigate mechanical properties. FSW could successfully produce defect-free welds on ODS plates. FSW produced a fine grain structure consisting of ferrite and martensite. Tensile strengths and elongations of the SZs were excellent at 298 K, compared to those of the BM. This study suggests that FSW might be an appropriate welding method of ODS steels. Oxide dispersion strengthened (ODS) ferritic-martensitic (FM) steel containing 9 wt%Cr is a promising candidate material for high temperature components operating in aggressive environments such as nuclear fusion and fission systems because of the excellent elevated temperature strength, corrosion and radiation resistance. These characteristics come from microstructures consisting of fine grains and nano-oxide particles dispersed in high number density. However, for more applications of ODS steel in nuclear systems, its weldability is the one of the barrier to be solved

  18. Nanostructure evolution in ODS steels under ion irradiation

    Directory of Open Access Journals (Sweden)

    S. Rogozhkin

    2016-12-01

    In this work, we carried out atom probe tomography (APT and transmission electron microscopy (TEM studies of three different ODS steels produced by mechanical alloying: ODS Eurofer, 13.5Cr ODS and 13.5Cr-0.3Ti ODS. These materials were investigated after irradiation with Fe (5.6MeV or Ti (4.8MeV ions up to 1015ion/cm2 and part of them up to 3×1015ion/cm2. In all cases, areas for TEM investigation were cut at a depth of ∼ 1.3µm from the irradiated surface corresponding to the peak of the radiation damage dose. It was shown that after irradiation at RT and at 300°С the number density of oxide particles in all the samples grew up. Meanwhile, the fraction of small particles in the size distribution has increased. APT revealed an essential increase in nanoclusters number and a change of their chemical composition at the same depth. The nanostructure was the most stable in 13.5Cr-0.3Ti ODS irradiated at 300°С: the increase of the fraction of small oxides was minimal and no change of nanocluster chemical composition was detected.

  19. High yttria ferritic ODS steels through powder forging

    Science.gov (United States)

    Kumar, Deepak; Prakash, Ujjwal; Dabhade, Vikram V.; Laha, K.; Sakthivel, T.

    2017-05-01

    Oxide dispersion strengthened (ODS) steels are being developed for future nuclear reactors. ODS Fe-18%Cr-2%W-0.2%Ti steels with 0, 0.35, 0.5, 1 and 1.5% Y2O3 (all compositions in weight%) dispersion were fabricated by mechanical alloying of elemental powders. The powders were placed in a mild steel can and forged in a stream of hydrogen gas at 1473 K. The steels were forged again to final density. The strength of ODS steel increased with yttria content. Though this was accompanied by a decrease in tensile elongation, all the steels showed significant ductility. The ductility in high yttria alloys may be attributed to improved inter-particle bonding between milled powders due to reduction of surface oxides by hydrogen. This may permit development of ODS steels with yttria contents higher than the conventional limit of 0.5%. It is suggested that powder forging is a promising route to fabricate ODS steels with high yttria contents and improved ductility.

  20. Surface chemistry and catalytic properties of VOX/Ti-MCM-41 catalysts for dibenzothiophene oxidation in a biphasic system

    International Nuclear Information System (INIS)

    González, J.; Chen, L.F.; Wang, J.A.; Manríquez, Ma.; Limas, R.; Schachat, P.; Navarrete, J.; Contreras, J.L.

    2016-01-01

    Highlights: • Oxidative desulfurization of model diesel was tested in a biphasic system. • ODS activity was proportional to the V 5+ /(V 4+ + V 5+ ) values of the catalysts. • Lewis acidity was related to vanadium content and catalytic activity. • 99.9% DBT was oxidized using 25%V 2 O 5 /Ti-MCM-41 at 60 °C within 60 min. - Abstract: A series of vanadium oxide supported on Ti-MCM-41 catalysts was synthesized via the incipient impregnation method by varying the vanadia loading from 5 wt% to 10, 15, 20 and 25 wt%. These catalysts were characterized by a variety of advanced techniques for investigating their crystalline structure, textural properties, and surface chemistry information including surface acidity, reducibility, vanadium oxidation states, and morphological features. The catalytic activities of the catalysts were evaluated in a biphasic reaction system for oxidative desulfurization (ODS) of a model diesel containing 300 ppm of dibenzothiophene (DBT) where acetonitrile was used as extraction solvent and H 2 O 2 as oxidant. ODS activity was found to be proportional to the V 5+ /(V 4+ + V 5+ ) values of the catalysts, indicating that the surface vanadium pentoxide (V 2 O 5 ) was the active phase. Reaction temperature would influence significantly the ODS efficiency; high temperature, i.e., 80 °C, would lead to low ODS reaction due to the partial decomposition of oxidant. All the catalysts contained both Lewis and Brønsted acid sites but the former was predominant. The catalysts with low vanadia loading (5 or 10 wt%V 2 O 5 ) had many Lewis acid sites and could strongly adsorb DBT molecule via the electron donation/acceptance action which resulted in an inhibition for the reaction of DBT with the surface peroxometallic species. The catalyst with high vanadia loading (25wt%V 2 O 5 /Ti-MCM-41) showed the highest catalytic activity and could remove 99.9% of DBT at 60 °C within 60 min.

  1. Oxide fuel fabrication technology development of the FaCT project (5). Current status on 9Cr-ODS steel cladding development for high burn-up fast reactor fuel

    International Nuclear Information System (INIS)

    Ohtsuka, Satoshi; Kaito, Takeji; Yano, Yasuhide; Yamashita, Shinichiro; Ogawa, Ryuichiro; Uwaba, Tomoyuki; Koyama, Shinichi; Tanaka, Kenya

    2011-01-01

    This paper describes evaluation results of in-reactor integrity of 9Cr and 12Cr-ODS steel cladding tubes and the plan for reliability improvement in homogeneous tube production, both of which are key points for the commercialized use of ODS steels as long-life fuel cladding tubes. A fuel assembly in the BOR-60 irradiation test including 9Cr and 12Cr-ODS fuel pins has achieved the highest burn-up, i.e. peak burn-up of 11.9at% and peak neutron dose of 51dpa, without any fuel pin rupture and microstructure instability. In another fuel assembly containing 9Cr and 12Cr-ODS steel fuel pins whose peak burn-up was 10.5at%, one 9Cr-ODS steel fuel pin failed near the upper end of the fuel column. A peculiar microstructure change occurred in the vicinity of the ruptured area. The primary cause of this fuel pin rupture and microstructure change was shown to be the presence of metallic Cr inclusions in the 9Cr-ODS steel tube, which had passed an ultrasonic inspection test for defects. In the next stage from 2011 to 2013, the fabrication technology of full pre-alloy 9Cr-ODS steel cladding tube will be developed, where the handling of elemental powder is prohibited in the process. (author)

  2. Efficient Air Desulfurization Catalysts Derived from Pig Manure Liquefaction Char

    Directory of Open Access Journals (Sweden)

    Rajiv Wallace

    2017-11-01

    Full Text Available Biochar from the liquefaction of pig manure was used as a precursor of H2S desulfurization adsorbents. In its inorganic matter, it contains marked quantities of calcium, magnesium and iron, which are known as hydrogen sulfide oxidation catalysts. The char was used either as-received or mixed with 10% nanographite. The latter was added to increase both the content of the carbon phase and conductivity. ZnCl2 in two different ratios of char to an activation agent (1:1 and 1:2 was used to create the porosity in the carbon phase. The content of the later was between 18–45%. The activated samples adsorbed 144 mg/g H2S. Sulfur was the predominant product of reactive adsorption. Its deposition in the pore system and blockage of the most active pores ceased the materials’ activity. The presence of the catalytic phase was necessary but not sufficient to guarantee good performance. The developed porosity, which can store oxidation products in the resulting composite, is essential for the good performance of the desulfurization process. The surface of the composite with nanographite showed the highest catalytic activity, similar to that of the commercial Midas® carbon catalyst. The results obtained indicate that a high quality reactive adsorbent/catalyst for H2S removal can be obtained from pig manure liquefaction wastes.

  3. BENCH-SCALE DEMONSTRATION OF HOT-GAS DESULFURIZATION TECHNOLOGY

    International Nuclear Information System (INIS)

    Unknown

    2000-01-01

    The U.S. Department of Energy (DOE), National Energy Technology Laboratory (NETL), is sponsoring research in advanced methods for controlling contaminants in hot coal gasifier gas (coal-derived fuel-gas) streams of integrated gasification combined-cycle (IGCC) power systems. The hot gas cleanup work seeks to eliminate the need for expensive heat recovery equipment, reduce efficiency losses due to quenching, and minimize wastewater treatment costs. Hot-gas desulfurization research has focused on regenerable mixed-metal oxide sorbents that can reduce the sulfur in coal-derived fuel-gas to less than 20 ppmv and can be regenerated in a cyclic manner with air for multicycle operation. Zinc titanate (Zn(sub 2)TiO(sub 4) or ZnTiO(sub 3)), formed by a solid-state reaction of zinc oxide (ZnO) and titanium dioxide (TiO(sub 2)), is currently one of the leading sorbents. Overall chemical reactions with Zn(sub 2)TiO(sub 4) during the desulfurization (sulfidation)-regeneration cycle are shown. The sulfidation/regeneration cycle can be carried out in a fixed-bed, moving-bed, or fluidized-bed reactor configuration. The fluidized-bed reactor configuration is most attractive because of several potential advantages including faster kinetics and the ability to handle the highly exothermic regeneration to produce a regeneration offgas containing a constant concentration of SO(sub 2)

  4. BENCH-SCALE DEMONSTRATION OF HOT-GAS DESULFURIZATION TECHNOLOGY

    International Nuclear Information System (INIS)

    Unknown

    1999-01-01

    The U.S. Department of Energy (DOE), National Energy Technology Laboratory (NETL), is sponsoring research in advanced methods for controlling contaminants in hot coal gasifier gas (coal-derived fuel-gas) streams of integrated gasification combined-cycle (IGCC) power systems. The hot gas cleanup work seeks to eliminate the need for expensive heat recovery equipment, reduce efficiency losses due to quenching, and minimize wastewater treatment costs. Hot-gas desulfurization research has focused on regenerable mixed-metal oxide sorbents that can reduce the sulfur in coal-derived fuel-gas to less than 20 ppmv and can be regenerated in a cyclic manner with air for multicycle operation. Zinc titanate (Zn(sub 2)TiO(sub 4) or ZnTiO(sub 3)), formed by a solid-state reaction of zinc oxide (ZnO) and titanium dioxide (TiO(sub 2)), is currently one of the leading sorbents. Overall chemical reactions with Zn(sub 2)TiO(sub 4) during the desulfurization (sulfidation)-regeneration cycle are shown. The sulfidation/regeneration cycle can be carried out in a fixed-bed, moving-bed, or fluidized-bed reactor configuration. The fluidized-bed reactor configuration is most attractive because of several potential advantages including faster kinetics and the ability to handle the highly exothermic regeneration to produce a regeneration offgas containing a constant concentration of SO(sub 2)

  5. The filler powders laser welding of ODS ferritic steels

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Shenyong, E-mail: s_y_liang@126.com; Lei, Yucheng; Zhu, Qiang

    2015-01-15

    Laser welding was performed on Oxide Dispersion Strengthened (ODS) ferritic steel with the self-designed filler powders. The filler powders were added to weld metal to produce nano-particles (Y–M–O and TiC), submicron particles (Y–M–O) and dislocation rings. The generated particles were evenly distributed in the weld metal and their forming mechanism and behavior were analyzed. The results of the tests showed that the nano-particles, submicron particles and dislocation rings were able to improve the micro-hardness and tensile strength of welded joint, and the filler powders laser welding was an effective welding method of ODS ferritic steel.

  6. Deep-desulfurization of the petroleum diesel using the heterogeneous carboxyl functionalized poly-ionic liquid

    OpenAIRE

    Kamlesh Rudreshwar Balinge; Avinash Ganesh Khiratkar; Manikandan Krishnamurthy; Dipesh S. Patle; Cheralathan K. K.; Pundlik Rambhau Bhagat

    2016-01-01

    Acidic carboxyl functionalized poly(ionic liquid) (CFPIL) has been synthesized and characterized by various techniques like FT-NMR, Fourier transform infrared spectroscopy (FTIR). In this work, deep oxidative desulfurization of model oil (thiophene dissolved in iso-octane) by CFPIL catalyst was carried out in presence of 30 wt% H2O2 solution as an oxidant. The effects of the hydrogen peroxide, amount of CFPIL, temperature-time and recyclability are scrutinized systematically. It was found tha...

  7. Shell launches its Claus off-gas desulfurization process

    Energy Technology Data Exchange (ETDEWEB)

    Groenendaal, W; van Meurs, H C.A.

    1972-01-01

    The Shell Flue Gas Desulfurization (SFGD) Process was developed for removal of sulfur oxides from flue gases originating from oil-fired boilers or furnaces. It can also be used to remove sulfur dioxide from Claus sulfur recovery tail gases if they are combined with boiler/furnace flue gases. For Claus tail gas only, the Shell Claus off-gas desulfurization process was developed. Claus unit operation and desulfurization by low temperature Claus processes and conversion/concentration processes are discussed. The new Shell process consists of a conversion/concentration process involving a reduction section and an amine absorption section. In the reduction section, all sulfur compounds and free sulfur are completely reduced to hydrogen sulfide with hydrogen, or hydrogen plus carbon monoxide, over a cobalt/molybdenum-on-alumina catalyst at a temperature of about 300/sup 0/C. Extensive bench scale studies on the reduction system have been carried out. A life test of more than 4000 hr showed a stable activity of the reduction catalyst, which means that in commercial units, very long catalyst lives can be expected. The commercial feasibility of the reduction section was further demonstrated in the Godorf refinery of Deutsche Shell AG. More than 80 absorption units using alkanolamine (AIDP) solutions have been installed. Bench scale studies of the ADIP absorption units were compared to commercial experience.The total capital investment of the new Shell process is 0.7, 2.0, and 3.2 $ times 10 to the 6th power for 100, 500, and 1000 tons of sulfur/sd capacity Claus units, respectively. The total operating costs for these units are, respectively, 610, 1930 and 3310 $/stream day. The capital investment corresponds to about 75% of the capital investment of the preceding Claus unit.

  8. Numerical Simulation of Desulfurization Behavior in Gas-Stirred Systems Based on Computation Fluid Dynamics-Simultaneous Reaction Model (CFD-SRM) Coupled Model

    Science.gov (United States)

    Lou, Wentao; Zhu, Miaoyong

    2014-10-01

    A computation fluid dynamics-simultaneous reaction model (CFD-SRM) coupled model has been proposed to describe the desulfurization behavior in a gas-stirred ladle. For the desulfurization thermodynamics, different models were investigated to determine sulfide capacity and oxygen activity. For the desulfurization kinetic, the effect of bubbly plume flow, as well as oxygen absorption and oxidation reactions in slag eyes are considered. The thermodynamic and kinetic modification coefficients are proposed to fit the measured data, respectively. Finally, the effects of slag basicity and gas flow rate on the desulfurization efficiency are investigated. The results show that as the interfacial reactions (Al2O3)-(FeO)-(SiO2)-(MnO)-[S]-[O] simultaneous kinetic equilibrium is adopted to determine the oxygen activity, and the Young's model with the modification coefficient R th of 1.5 is adopted to determine slag sulfide capacity, the predicted sulfur distribution ratio LS agrees well with the measured data. With an increase of the gas blowing time, the predicted desulfurization rate gradually decreased, and when the modification parameter R k is 0.8, the predicted sulfur content changing with time in ladle agrees well with the measured data. If the oxygen absorption and oxidation reactions in slag eyes are not considered in this model, then the sulfur removal rate in the ladle would be overestimated, and this trend would become more obvious with an increase of the gas flow rate and decrease of the slag layer height. With the slag basicity increasing, the total desulfurization ratio increases; however, the total desulfurization ratio changes weakly as the slag basicity exceeds 7. With the increase of the gas flow rate, the desulfurization ratio first increases and then decreases. When the gas flow rate is 200 NL/min, the desulfurization ratio reaches a maximum value in an 80-ton gas-stirred ladle.

  9. Surface chemistry and catalytic properties of VO{sub X}/Ti-MCM-41 catalysts for dibenzothiophene oxidation in a biphasic system

    Energy Technology Data Exchange (ETDEWEB)

    González, J. [ESIQIE, Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional s/n, 07738 Col. Zacatenco, Mexico City (Mexico); Chen, L.F., E-mail: lchen@ipn.mx [ESIQIE, Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional s/n, 07738 Col. Zacatenco, Mexico City (Mexico); Wang, J.A.; Manríquez, Ma.; Limas, R. [ESIQIE, Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional s/n, 07738 Col. Zacatenco, Mexico City (Mexico); Schachat, P.; Navarrete, J. [Dirección de Investigación, Instituto Mexicano del Petróleo, Eje Lázaro Cárdenas 152, 07730 México D.F. (Mexico); Contreras, J.L. [Laboratorio de Catálisis y Polímeros, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-A, Av. San Pablo No. 180, 02200 México D.F. (Mexico)

    2016-08-30

    Highlights: • Oxidative desulfurization of model diesel was tested in a biphasic system. • ODS activity was proportional to the V{sup 5+}/(V{sup 4+} + V{sup 5+}) values of the catalysts. • Lewis acidity was related to vanadium content and catalytic activity. • 99.9% DBT was oxidized using 25%V{sub 2}O{sub 5}/Ti-MCM-41 at 60 °C within 60 min. - Abstract: A series of vanadium oxide supported on Ti-MCM-41 catalysts was synthesized via the incipient impregnation method by varying the vanadia loading from 5 wt% to 10, 15, 20 and 25 wt%. These catalysts were characterized by a variety of advanced techniques for investigating their crystalline structure, textural properties, and surface chemistry information including surface acidity, reducibility, vanadium oxidation states, and morphological features. The catalytic activities of the catalysts were evaluated in a biphasic reaction system for oxidative desulfurization (ODS) of a model diesel containing 300 ppm of dibenzothiophene (DBT) where acetonitrile was used as extraction solvent and H{sub 2}O{sub 2} as oxidant. ODS activity was found to be proportional to the V{sup 5+}/(V{sup 4+} + V{sup 5+}) values of the catalysts, indicating that the surface vanadium pentoxide (V{sub 2}O{sub 5}) was the active phase. Reaction temperature would influence significantly the ODS efficiency; high temperature, i.e., 80 °C, would lead to low ODS reaction due to the partial decomposition of oxidant. All the catalysts contained both Lewis and Brønsted acid sites but the former was predominant. The catalysts with low vanadia loading (5 or 10 wt%V{sub 2}O{sub 5}) had many Lewis acid sites and could strongly adsorb DBT molecule via the electron donation/acceptance action which resulted in an inhibition for the reaction of DBT with the surface peroxometallic species. The catalyst with high vanadia loading (25wt%V{sub 2}O{sub 5}/Ti-MCM-41) showed the highest catalytic activity and could remove 99.9% of DBT at 60 °C within 60 min.

  10. Activation volume of martensitic ODS steel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D. W.; Noh, S.; Kim, T. K. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Apparent activation volume as a function of temperature is 86b{sup 3}-42b{sup 3}. Activation volume decreases with increasing temperature. Activation volume changes scarcely with decreasing strain rate. Strain rate sensitivity increases with increasing temperature and decreasing strain rate. Nano-sized oxide dispersion strengthened (ODS) martensitic steel has a high strength, low thermal expansion coefficient, high thermal conductivity, and a good swelling resistance. Martensitic ODS steel is a candidate material for fuel cladding of sodium cooled fast breeder reactor (SFR). The plastic flow stress is determined through the interaction of dislocations with the obstacles encountered inside lattice. Dislocation movement through the lattice or past an obstacle requires surmounting of the energy barrier by a combination of applied stress and thermal activation. The plastic deformation of materials is a thermally activated process dependent upon time, temperature, and strain rate. Characterization of the rate controlling mechanism for plastic deformation due to dislocation motion in crystalline materials is done by the assessment of activation volume based on thermal activation analysis.

  11. Evaluation of mechanical properties and nano-meso structures of 9–11%Cr ODS steels

    Energy Technology Data Exchange (ETDEWEB)

    Tanno, Takashi, E-mail: tanno.takashi@jaea.go.jp [Japan Atomic Energy Agency, Oarai, Ibaraki 311-1393 (Japan); Ohtsuka, Satoshi; Yano, Yasuhide; Kaito, Takeji [Japan Atomic Energy Agency, Oarai, Ibaraki 311-1393 (Japan); Oba, Yojiro; Ohnuma, Masato [National Institute for Materials Science, Tsukuba 305-1195 (Japan); Koyama, Shinichi; Tanaka, Kenya [Japan Atomic Energy Agency, Oarai, Ibaraki 311-1393 (Japan)

    2013-09-15

    Highlights: • We successfully manufactured 11Cr-ODS steels with residual α-ferrite controlled. • Dispersion conditions of nano oxide particles were quantitatively characterized. • Tungsten solid solution could improve only tensile strength of ODS steels at 973 K. • Oxide dispersion strengthening was dominant in creep strength of ODS steels at 973 K. -- Abstract: This study carried out mechanical tests and microstructural characterizations of several 9Cr and 11Cr-ODS tempered martensitic steels. From those results, the appropriate chemical composition range of 11Cr-ODS tempered martensitic steel was discussed from the viewpoint of high temperature strength improvement. It was shown that the residual α-ferrite fraction in 11Cr-ODS steel was successfully controlled to the same level as the 9Cr-ODS steel, which has excellent high temperature strength, by selecting the chemical compositions on the basis of the multi-component phase diagram. The tensile strength decreased with decreasing W content from 2.0 to 1.4 wt%. On the other hand, creep strength at 973 K did not degrade by the decreasing W content. Both tensile strength and creep strength increased with increasing population of the nano-sized oxide particles. Small angle X-ray scattering analysis revealed that titanium and excess oxygen contents were key parameters in order to improve the dispersion conditions of nano-sized oxide particles.

  12. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

    Energy Technology Data Exchange (ETDEWEB)

    Berggren, M.H.; Jha, M.C.

    1989-10-01

    AMAX Research Development Center (AMAX R D) investigated methods for enhancing the reactivity and durability of zinc ferrite desulfurization sorbents. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For this program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such as size, strength, and specific surface area during 10 cycles of sulfidation and oxidation. Two base case sorbents, a spherical pellet and a cylindrical extrude used in related METC-sponsored projects, were used to provide a basis for the aimed enhancement in durability and reactivity. Sorbent performance was judged on the basis of physical properties, single particle kinetic studies based on thermogravimetric (TGA) techniques, and multicycle bench-scale testing of sorbents. A sorbent grading system was utilized to quantify the characteristics of the new sorbents prepared during the program. Significant enhancements in both reactivity and durability were achieved for the spherical pellet shape over the base case formulation. Overall improvements to reactivity and durability were also made to the cylindrical extrude shape. The primary variables which were investigated during the program included iron oxide type, zinc oxide:iron oxide ratio, inorganic binder concentration, organic binder concentration, and induration conditions. The effects of some variables were small or inconclusive. Based on TGA studies and bench-scale tests, induration conditions were found to be very significant.

  13. Friction Stir Processing of ODS and FM Steels

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Suk Hoon; Chun, Young Bum; Noh, Sang Hoon; Jang, Jin Sung; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    In ODS steels, it is well known that uniform nano-oxide dispersoids act as pinning points to obstruct dislocation and grain boundary motion, however, those advantages will be disappeared while the material is subjected to the high temperature of conventional fusion welding. Rotary friction welding, also referred to as friction stir welding (FSW), has shown great promise as a method for welding traditionally difficult to weld materials such as aluminum alloys. This relatively new technology has more recently been applied to higher melting temperature alloys such as steels, nickel-based and titanium alloys. Friction stir processing (FSP) is a method of changing the properties of a metal through intense, localized plastic deformation. FSW is the precursor of the FSP technique. When ideally implemented, this process mixes the material without changing the phase and creates a microstructure with fine, equiaxed grains. This homogeneous grain structure, separated by high-angle boundaries, allows some alloys to take on superplastic properties. In this study, FSW is used as a substitutive welding process between FMS tube and ODS parts. The dimension of tube is 7.0 OD, 0.5 T. During the FSW, dynamic-recrystallized grains are developed; the uniform oxides dispersion is preserved in the metal matrix. The microstructure and microtexture of the material near the stir zone is found to be influenced by the rotational behavior of the tool. The additive effect from FSP on sample surface is considered. Since the mechanical alloying (MA) and FSP commonly apply extreme shear deformation on materials, the dispersion of oxide particle in ODS steels is very active during both processes. Friction stir welding appears to be a very promising technique for the welding of FMS and ODS steels in the form of sheet and tube. FSW could successfully produce defect-free welds on FMS tubes and ODS ring assembly. FSW produces a fine grain structure consisting of ferrite and martensite, and the oxide

  14. Friction Stir Processing of ODS and FM Steels

    International Nuclear Information System (INIS)

    Kang, Suk Hoon; Chun, Young Bum; Noh, Sang Hoon; Jang, Jin Sung; Kim, Tae Kyu

    2013-01-01

    In ODS steels, it is well known that uniform nano-oxide dispersoids act as pinning points to obstruct dislocation and grain boundary motion, however, those advantages will be disappeared while the material is subjected to the high temperature of conventional fusion welding. Rotary friction welding, also referred to as friction stir welding (FSW), has shown great promise as a method for welding traditionally difficult to weld materials such as aluminum alloys. This relatively new technology has more recently been applied to higher melting temperature alloys such as steels, nickel-based and titanium alloys. Friction stir processing (FSP) is a method of changing the properties of a metal through intense, localized plastic deformation. FSW is the precursor of the FSP technique. When ideally implemented, this process mixes the material without changing the phase and creates a microstructure with fine, equiaxed grains. This homogeneous grain structure, separated by high-angle boundaries, allows some alloys to take on superplastic properties. In this study, FSW is used as a substitutive welding process between FMS tube and ODS parts. The dimension of tube is 7.0 OD, 0.5 T. During the FSW, dynamic-recrystallized grains are developed; the uniform oxides dispersion is preserved in the metal matrix. The microstructure and microtexture of the material near the stir zone is found to be influenced by the rotational behavior of the tool. The additive effect from FSP on sample surface is considered. Since the mechanical alloying (MA) and FSP commonly apply extreme shear deformation on materials, the dispersion of oxide particle in ODS steels is very active during both processes. Friction stir welding appears to be a very promising technique for the welding of FMS and ODS steels in the form of sheet and tube. FSW could successfully produce defect-free welds on FMS tubes and ODS ring assembly. FSW produces a fine grain structure consisting of ferrite and martensite, and the oxide

  15. A three-phase comprehensive mathematical model of desulfurization in electroslag remelting process

    International Nuclear Information System (INIS)

    Wang, Qiang; Li, Guangqiang; He, Zhu; Li, Baokuan

    2017-01-01

    Highlights: • First developed a three-phase coupled model of desulfurization in ESR process. • The MHD thermal flow in the reactor was clarified. • Distributions of sulfur concentration in the three phases were demonstrated. • An experiment was carried out to validate the simulation. - Abstract: A three-phase comprehensive mathematical model has been established to study the desulfurization behavior in electroslag remelting (ESR) process. The solutions of the mass, momentum, energy, and species conservation equations were simultaneously calculated by the finite volume method. The Joule heating and Lorentz force were fully coupled through solving the Maxwell’s equations with the assistance of the magnetic potential vector. The movements of the air-slag and slag-metal interfaces were described by the volume of fluid (VOF) approach. In order to include the influences of the air, the slag and the electric current on the desulfurization, a thermodynamic and kinetic module was introduced. An experiment was conducted to validate the model. The completely comparison between the measured and simulated data indicates that the model can describe the desulfurization behavior in the ESR process with an acceptable accuracy. The sulfur in the metal would be transferred into the slag under the combined effect of the slag treatment and the electrochemical reaction, and is primarily achieved in the period of the droplet formation. The sulfur in the slag then could be transferred into the air because of the oxidation. The maximum calculated removal ratio in the whole process is around 88%.

  16. Cerium Titanate Nano dispersoids in Ni-base ODS Alloy

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Suk Hoon; Chun, Young-Bum; Rhee, Chang-Kyu; Jang, Jinsung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Chung, Hee-Suk [Korea Basic Science Institute, Jeonju (Korea, Republic of)

    2016-10-15

    Oxide-dispersion-strengthened (ODS) nickel-base alloys have potential for use in rather demanding elevated-temperature environments, such as aircraft turbine engines, heat exchanger of nuclear reactor. For improved high temperature performance, several ODS alloys were developed which possess good elevated temperature strength and over-temperature capacity plus excellent static oxidation resistance. The high temperature strength of ODS alloys is due to the presence of a uniform dispersion of fine, inert particles. Ceria mixed oxides have been studied because of their application potential in the formation of nanoclusters. By first principle study, it was estimated that the formation energy of the Ce-O dimer with voids in the nickel base alloy is lower than other candidates. The result suggests that the dispersion of the Ceria mixed oxides can suppress the voiding or swelling behavior of nickel base alloy during neutron irradiation. In this study, the evolution of cerium titanate nano particles was investigated using in-situ TEM. It was found that the Ce{sub 2}Ti{sub 3}O{sub 9} phase was easily formed rather than remain as CeO{sub 2} during annealing; Ti was effective to form the finer oxide particles. Ce{sub 2}Ti{sub 3}O{sub 9} is expected to do the great roll as dispersoids in Ni-base alloy, contribute to achieve the better high temperature property, high swelling resistance during neutron radiation.

  17. Development of ODS-Fe{sub 3}Al alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wright, I.G.; Pint, B.A.; Tortorelli, P.F.; McKamey, C.G. [Oak Ridge National Lab., TN (United States)

    1997-12-01

    The overall goal of this program is to develop an oxide dispersion-strengthened (ODS) version of Fe{sub 3}Al that has sufficient creep strength and resistance to oxidation at temperatures in the range 1000 to 1200 C to be suitable for application as heat exchanger tubing in advanced power generation cycles. The main areas being addressed are: (a) alloy processing to achieve the desired alloy grain size and shape, and (b) optimization of the oxidation behavior to provide increased service life compared to semi-commercial ODS-FeCrAl alloys intended for the same applications. The recent studies have focused on mechanically-alloyed powder from a commercial alloy vendor. These starting alloy powders were very clean in terms of oxygen content compared to ORNL-produced powders, but contained similar levels of carbon picked up during the milling process. The specific environment used in milling the powder appears to exert a considerable influence on the post-consolidation recrystallization behavior of the alloy. A milling environment which produced powder particles having a high surface carbon content resulted in a consolidated alloy which readily recrystallized, whereas powder with a low surface carbon level after milling resulted in no recrystallization even at 1380 C. A feature of these alloys was the appearance of voids or porosity after the recrystallization anneal, as had been found with ORNL-produced alloys. Adjustment of the recrystallization parameters did not reveal any range of conditions where recrystallization could be accomplished without the formation of voids. Initial creep tests of specimens of the recrystallized alloys indicated a significant increase in creep strength compared to cast or wrought Fe{sub 3}Al, but the specimens failed prematurely by a mechanism that involved brittle fracture of one of the two grains in the test cross section, followed by ductile fracture of the remaining grain. The reasons for this behavior are not yet understood. The

  18. Methods for dry desulfurization of flue gas

    International Nuclear Information System (INIS)

    Bjondahl, F.

    2002-01-01

    In this report different types of dry desulfurization processes are de-scribed. These processes are utilized for the removal of SO 2 from flue gases. Basic process descriptions, information on different sorbent types and their properties and some comments based on the authors own experience are included. Information on disposal or use of the end product from these processes is also provided. (orig.)

  19. Ultra-high temperature tensile properties of ODS steel claddings under severe accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Y., E-mail: yano.yasuhide@jaea.go.jp [Japan Atomic Energy Agency, 4002, Narita-cho, Oarai-machi, Ibaraki, 311-1393 (Japan); Tanno, T.; Oka, H.; Ohtsuka, S.; Inoue, T.; Kato, S.; Furukawa, T.; Uwaba, T.; Kaito, T. [Japan Atomic Energy Agency, 4002, Narita-cho, Oarai-machi, Ibaraki, 311-1393 (Japan); Ukai, S.; Oono, N. [Materials Science and Engineering, Faculty of Engineering, Hokkaido University, N13, W-8, Kita-ku, Sapporo, Hokkaido, 060-8628 (Japan); Kimura, A. [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Hayashi, S. [Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Torimaru, T. [Nippon Nuclear Fuel Development Co., Ltd., 2163, Narita-cho, Oarai-machi, Ibaraki, 311-1313 (Japan)

    2017-04-15

    Ultra-high temperature ring tensile tests were performed to investigate the tensile behavior of oxide dispersion strengthened (ODS) steel claddings and wrapper materials under severe accident conditions with temperatures ranging from room temperature to 1400 °C which is close to the melting point of core materials. The experimental results showed that the tensile strength of 9Cr-ODS steel claddings was highest in the core materials at ultra-high temperatures of 900–1200 °C, but there was significant degradation in the tensile strength of 9Cr-ODS steel claddings above 1200 °C. This degradation was attributed to grain boundary sliding deformation with γ/δ transformation, which is associated with reduced ductility. By contrast, the tensile strength of recrystallized 12Cr-ODS and FeCrAl-ODS steel claddings retained its high value above 1200 °C, unlike the other tested materials.

  20. Ultra-high temperature tensile properties of ODS steel claddings under severe accident conditions

    Science.gov (United States)

    Yano, Y.; Tanno, T.; Oka, H.; Ohtsuka, S.; Inoue, T.; Kato, S.; Furukawa, T.; Uwaba, T.; Kaito, T.; Ukai, S.; Oono, N.; Kimura, A.; Hayashi, S.; Torimaru, T.

    2017-04-01

    Ultra-high temperature ring tensile tests were performed to investigate the tensile behavior of oxide dispersion strengthened (ODS) steel claddings and wrapper materials under severe accident conditions with temperatures ranging from room temperature to 1400 °C which is close to the melting point of core materials. The experimental results showed that the tensile strength of 9Cr-ODS steel claddings was highest in the core materials at ultra-high temperatures of 900-1200 °C, but there was significant degradation in the tensile strength of 9Cr-ODS steel claddings above 1200 °C. This degradation was attributed to grain boundary sliding deformation with γ/δ transformation, which is associated with reduced ductility. By contrast, the tensile strength of recrystallized 12Cr-ODS and FeCrAl-ODS steel claddings retained its high value above 1200 °C, unlike the other tested materials.

  1. Surface chemistry and catalytic properties of VOX/Ti-MCM-41 catalysts for dibenzothiophene oxidation in a biphasic system

    Science.gov (United States)

    González, J.; Chen, L. F.; Wang, J. A.; Manríquez, Ma.; Limas, R.; Schachat, P.; Navarrete, J.; Contreras, J. L.

    2016-08-01

    A series of vanadium oxide supported on Ti-MCM-41 catalysts was synthesized via the incipient impregnation method by varying the vanadia loading from 5 wt% to 10, 15, 20 and 25 wt%. These catalysts were characterized by a variety of advanced techniques for investigating their crystalline structure, textural properties, and surface chemistry information including surface acidity, reducibility, vanadium oxidation states, and morphological features. The catalytic activities of the catalysts were evaluated in a biphasic reaction system for oxidative desulfurization (ODS) of a model diesel containing 300 ppm of dibenzothiophene (DBT) where acetonitrile was used as extraction solvent and H2O2 as oxidant. ODS activity was found to be proportional to the V5+/(V4+ + V5+) values of the catalysts, indicating that the surface vanadium pentoxide (V2O5) was the active phase. Reaction temperature would influence significantly the ODS efficiency; high temperature, i.e., 80 °C, would lead to low ODS reaction due to the partial decomposition of oxidant. All the catalysts contained both Lewis and Brønsted acid sites but the former was predominant. The catalysts with low vanadia loading (5 or 10 wt%V2O5) had many Lewis acid sites and could strongly adsorb DBT molecule via the electron donation/acceptance action which resulted in an inhibition for the reaction of DBT with the surface peroxometallic species. The catalyst with high vanadia loading (25wt%V2O5/Ti-MCM-41) showed the highest catalytic activity and could remove 99.9% of DBT at 60 °C within 60 min.

  2. Photooxidative desulfurization for diesel using Fe / N - TiO2 photocatalyst

    Science.gov (United States)

    Khan, Muhammad Saqib; Kait, Chong Fai; Mutalib, Mohd Ibrahim Abdul

    2014-10-01

    A series of N - TiO2 with different mol% N was synthesized via sol-gel method and characterized using thermal gravimetric analyzer and raman spectroscopy. 0.2 wt% Fe was incorporated onto the calcined (200°C) N - TiO2 followed by calcination at 200°C, 250°C and 300°C. Photooxidative desulfurization was conducted in the presence of 0.2wt% Fe / N - TiO2 with different mol% N with and without oxidant (H2O2). Oxidative desulfurization was only achieved when H2O2 was used while without H2O2 no major effect on the sulfur removal. 0.2Fe -30N - H2O2 photocatalysts showed best performance at all calcination temperatures as compared to other mol% N - H2O2 photocatalysts. 16.45% sulfur removal was achieved using photocatalysts calcined at 300 °C.

  3. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent. Volume 1, Bench-scale testing and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jha, M.C.; Berggren, M.H.

    1989-05-02

    AMAX Research & Development Center (AMAX R&D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

  4. Two-Phase Phenomena In Wet Flue Gas Desulfurization Process

    International Nuclear Information System (INIS)

    Minzer, U.; Moses, E.J.; Toren, M.; Blumenfeld, Y.

    1998-01-01

    In order to reduce sulfur oxides discharge, Israel Electric Corporation (IEC) is building a wet Flue Gas Desulfurization (FGD) facility at Rutenberg B power station. The primary objective of IEC is to minimize the occurrence of stack liquid discharge and avoid the discharge of large droplets, in order to prevent acid rain around the stack. Liquid discharge from the stack is the integrated outcome of two-phase processes, which are discussed in this work. In order to estimate droplets discharge the present investigation employs analytical models, empirical tests, and numerical calculations of two-phase phenomena. The two-phase phenomena are coupled and therefore cannot be investigated separately. The present work concerns the application of Computational Fluid Dynamic (CFD) as an engineering complementary tool in the IEC investigation

  5. Desulfurization of dibenzothiophene by Corynebacterium sp. strain SY1

    International Nuclear Information System (INIS)

    Omori, Toshio; Monna, L.; Saiki, Yuko; Kodama, Tohru

    1992-01-01

    Strain SY1, identified as a Corynebacterium sp., was isolated on the basis of the ability to utilize dibenzothiophene (DBT) as a sole source of sulfur. Strain SY1 could utilize a wide range of organic and inorganic sulfur compounds, such as DBT sulfone, dimethyl sulfide, dimethyl sulfoxide, dimethyl sulfone, CS 2 , FeS 2 , and even elemental sulfur. Strain SY1 metabolized DBT to dibenzothiophene-5-oxide, DBT sulfone, and 2-hydroxybiphenyl, which was subsequently nitrated to produce at least two different hydroxynitrobiphenyls during cultivation. These metabolites were separated by silica gel column chromatography and identified by nuclear magnetic resonance, UV, and mass spectral techniques. Resting cells of SY1 desulfurized toluenesulfonic acid and released sulfite anion. On the basis of these results, a new DBT degradation pathway is proposed

  6. ADVANCED SULFUR CONTROL CONCEPTS FOR HOT-GAS DESULFURIZATION TECHNOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    A. LOPEZ ORTIZ; D.P. HARRISON; F.R. GROVES; J.D. WHITE; S. ZHANG; W.-N. HUANG; Y. ZENG

    1998-10-31

    a twenty-five-cycle test. The sorbent was exposed for 58 consecutive days to temperatures between 600°C and 800°C and gas atmospheres from highly reducing to highly oxidizing without measurable loss of sulfur capacity or reactivity. In the process analysis phase of this study, a two-stage desulfurization process using cerium sorbent with SO2 regeneration followed by zinc sorbent with dilute O2 regeneration was compared to a single-stage process using zinc sorbent and O2 regeneration with SO2 in the regeneration product gas converted to elemental sulfur using the direct sulfur recovery process (DSRP). Material and energy balances were calculated using the process simulation package PRO/II. Major process equipment was sized and a preliminary economic analysis completed. Sorbent replacement rate, which is determined by the multicycle sorbent durability, was found to be the most significant factor in both processes. For large replacement rates corresponding to average sorbent lifetimes of 250 cycles or less, the single-stage zinc sorbent process with DSRP was estimated to be less costly. However, the cost of the two-stage cerium sorbent process was more sensitive to sorbent replacement rate, and, as the required replacement rate decreased, the economics of the two-stage process improved. For small sorbent replacement rates corresponding to average sorbent lifetimes of 1000 cycles or more, the two-stage cerium process was estimated to be less costly. In the relatively wide middle range of sorbent replacement rates, the relative economics of the two processes depends on other factors such as the unit cost of sorbents, oxygen, nitrogen, and the relative capital costs.

  7. Advanced sulfur control concepts for hot-gas desulfurization technology

    International Nuclear Information System (INIS)

    Lopez Ortiz, A.; Harrison, D.P.; Groves, F.R.; White, J.D.; Zhang, S.; Huang, W.N.; Zeng, Y.

    1998-01-01

    twenty-five-cycle test. The sorbent was exposed for 58 consecutive days to temperatures between 600C and 800C and gas atmospheres from highly reducing to highly oxidizing without measurable loss of sulfur capacity or reactivity. In the process analysis phase of this study, a two-stage desulfurization process using cerium sorbent with SO2 regeneration followed by zinc sorbent with dilute O2 regeneration was compared to a single-stage process using zinc sorbent and O2 regeneration with SO2 in the regeneration product gas converted to elemental sulfur using the direct sulfur recovery process (DSRP). Material and energy balances were calculated using the process simulation package PRO/II. Major process equipment was sized and a preliminary economic analysis completed. Sorbent replacement rate, which is determined by the multicycle sorbent durability, was found to be the most significant factor in both processes. For large replacement rates corresponding to average sorbent lifetimes of 250 cycles or less, the single-stage zinc sorbent process with DSRP was estimated to be less costly. However, the cost of the two-stage cerium sorbent process was more sensitive to sorbent replacement rate, and, as the required replacement rate decreased, the economics of the two-stage process improved. For small sorbent replacement rates corresponding to average sorbent lifetimes of 1000 cycles or more, the two-stage cerium process was estimated to be less costly. In the relatively wide middle range of sorbent replacement rates, the relative economics of the two processes depends on other factors such as the unit cost of sorbents, oxygen, nitrogen, and the relative capital costs

  8. BENCH-SCALE DEMONSTRATION OF HOT-GAS DESULFURIZATION TECHNOLOGY

    International Nuclear Information System (INIS)

    Unknown

    1999-01-01

    The U.S. Department of Energy (DOE), Federal Energy Technology Center (FETC), is sponsoring research in advanced methods for controlling contaminants in hot coal gasifier gas (coal-derived fuel-gas) streams of integrated gasification combined-cycle (IGCC) power systems. The hot gas cleanup work seeks to eliminate the need for expensive heat recovery equipment, reduce efficiency losses due to quenching, and minimize wastewater treatment costs. Hot-gas desulfurization research has focused on regenerable mixed-metal oxide sorbents that can reduce the sulfur in coal-derived fuel-gas to less than 20 ppmv and can be regenerated in a cyclic manner with air for multicycle operation. Zinc titanate (Zn(sub 2) TiO(sub 4) or ZnTiO(sub 3)), formed by a solid-state reaction of zinc oxide (ZnO) and titanium dioxide (TiO(sub 2)), is currently one of the leading sorbents. Overall chemical reactions with Zn(sub 2) TiO(sub 4) during the desulfurization (sulfidation)-regeneration cycle are shown below: Sulfidation: Zn(sub 2) TiO(sub 4)+ 2H(sub 2)S(yields) 2ZnS+ TiO(sub 2)+ 2H(sub 2)O; Regeneration: 2ZnS+ TiO(sub 2)+ 3O(sub 2)(yields) Zn(sub 2) TiO(sub 4)+ 2SO(sub 2) The sulfidation/regeneration cycle can be carried out in a fixed-bed, moving-bed, or fluidized-bed reactor configuration. The fluidized-bed reactor configuration is most attractive because of several potential advantages including faster kinetics and the ability to handle the highly exothermic regeneration to produce a regeneration offgas containing a constant concentration of SO(sub 2)

  9. Influence of Normalizing Temperature on the Microstructure and Hardness of 9Cr-1Mo ODS Steel

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Ki Nam; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Kyu Tae [Dongguk University, Gyeongju (Korea, Republic of)

    2016-10-15

    Oxide dispersion strengthened(ODS) steel has superior high-temperature strength and creep properties because fine oxide particles having an excellent stability at high temperatures are uniformly distributed in the matrix. ODS steel has being developed for structure materials of sodium fast cooled reactor(SFR) because of its excellent irradiation resistance and mechanical properties. 9Cr-1Mo ODS steel has better high temperature strength and irradiation resistance than common 9Cr-1Mo steel because Y{sub 2}O{sub 3} nano-sized particles which interrupt dislocation movement and grain boundary slip are uniformly dispersed in the martensite matrix. The mechanical properties of the ODS steels are mainly determined by their microstructures, and the microstructure is considerably decided by the heat-treatment conditions. This study focused on the effect of normalizing temperature on microstructure and hardness of 9Cr-1Mo martensitic ODS steel so as to optimize the heat-treatment condition. In this study, the effect of normalizing temperature on mechanical property and microstructures of 9Cr-1Mo martensitic ODS steel was investigated. It was shown that the microhardness was steadily increased with increasing of the normalizing temperature. According to TEM observation, mechanical property of 9Cr-1Mo ODS steel was significantly affected by lath width. These observations, could be useful to understand the relationship between normalizing temperature and microstructure.

  10. The Knossos Od Series. An Epigraphical Study

    DEFF Research Database (Denmark)

    Nosch, Marie-Louise Bech

    This study is an epigraphical investigation of the Linear B records from the West Wing in the palace of Knossos. Its focus is the group of 61 unclassified Od tablets with the ideogram for wool. The author presents a new classification of the Od tablets by identifying new sets, and by integrating...... unclassified Od tablets into existing Od sets or into other series recording wool, such as the two well known and thoroughly researched "bureaux", the textile and the sheep administration. Recent work by FIRTH on find-places has provided new insights for this study. In the present study, 29 prefix changes...... are suggested. Only few unclassified Od tablets, however, can be associated with the initial parts of textile production in which scribes 103 and 113 set targets and manage the production. Rather, many unclassified Od tablets belong to the final stages of the textile production, that is, the finishing...

  11. ZASEBNOST OD RABE DO ZLORABE

    OpenAIRE

    Flegerič, Tamara

    2012-01-01

    Nastanek interneta in njegova popularizacija s pojavom svetovnega spleta je povzročil veliko revolucijo. Najpopularnejše orodje spleta 2.0 in s tem najpomembnejši medij spletne komunikacije so postala spletna socialna omrežja. Spletno socialno omrežje, ki je postalo pravi fenomen in kateremu smo se posvetili v pričujoči diplomski nalogi, je Facebook. V diplomskem delu z naslovom »Zasebnost od rabe do zlorabe« sta predstavljeni zasebnost in varnost na Facebooku. V teoretičnem delu se bomo posv...

  12. Microstructural and mechanical property characterization of ingot metallurgy ODS iron aluminide

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Howell, C.R. [Oak Ridge National Lab., TN (United States); Hall, F.; Valykeo, J. [Hoskins Mfg. Co., Hamburg, MI (United States)

    1997-12-01

    This paper deals with a novel, lower cost method of producing a oxide dispersion strengthened (ODS) iron-aluminide alloy. A large 250-kg batch of ODS iron-aluminide alloy designated as FAS was produced by Hoskins Manufacturing Company (Hoskins) [Hamburg, Michigan] using the new process. Plate and bar stock of the ODS alloy were the two major products received. Each of the products was characterized for its microstructure, including grain size and uniformity of oxide dispersion. Tensile tests were completed from room temperature to 1100 C. Only 100-h creep tests were completed at 800 and 1000 C. The results of these tests are compared with the commercial ODS alloy designated as MA-956. An assessment of these data is used to develop future plans for additional work and identifying applications.

  13. Age-hardening susceptibility of high-Cr ODS ferritic steels and SUS430 ferritic steel

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Dongsheng, E-mail: chen.dongsheng85@gmail.com [Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Kimura, Akihiko; Han, Wentuo; Je, Hwanil [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan)

    2015-10-15

    Highlights: • The role of oxide particles in α/α′ phase decomposition behavior; microstructure of phase decomposition observed by TEM. • The characteristics of ductility loss caused by age-hardening. • Correlation of phase decomposition and age-hardening explained by dispersion strengthened models. • Age-hardening susceptibility of ODS steels and SUS430 steel. - Abstract: The effect of aging on high-Cr ferritic steels was investigated with focusing on the role of oxide particles in α/α′ phase decomposition behavior. 12Cr-oxide dispersion strengthened (ODS) steel, 15Cr-ODS steel and commercial SUS430 steel were isothermally aged at 475 °C for up to 10,000 h. Thermal aging caused a larger hardening in SUS430 than 15Cr-ODS, while 12Cr-ODS showed almost no hardening. A characteristic of the ODS steels is that the hardening was not accompanied by the significant loss of ductility that was observed in SUS430 steel. After aging for 2000 h, SUS430 steel shows a larger ductile–brittle transition temperature (DBTT) shift than 15Cr-ODS steel, which suggests that the age-hardening susceptibility is lower in 15Cr-ODS steel than in conventional SUS430 steel. Thermal aging leaded to a large number of Cr-rich α′ precipitates, which were confirmed by transmission electron microscopy (TEM). Correlation of age-hardening and phase decomposition was interpreted by Orowan type strengthening model. Results indicate that oxide particles cannot only suppress ductility loss, but also may influence α/α′ phase decomposition kinetics.

  14. Investigation of the relationships between mechanical properties and microstructure in a Fe-9%Cr ODS steel

    OpenAIRE

    Hary Benjamin; Guilbert Thomas; Wident Pierre; Baudin Thierry; Logé Roland; de Carlan Yann

    2016-01-01

    Ferritic-martensitic Oxide Dispersion Strengthened (ODS) steels are potential materials for fuel pin cladding in Sodium Fast Reactor (SFR) and their optimisation is essential for future industrial applications. In this paper, a feasibility study concerning the generation of tensile specimens using a quenching dilatometer is presented. The ODS steel investigated contains 9%Cr and exhibits a phase transformation between ferrite and austenite around 870 °C. The purpose was to generate different ...

  15. Hydrogen Transport and Trapping in ODS-EUROFER

    International Nuclear Information System (INIS)

    Esteban, G.A.; Pena, A.; Legarda, F.; Lindau, R.

    2006-01-01

    Oxide Dispersion Strengthened (ODS) EUROFER is a candidate structural material to be used in the design of several blanket options [R. Lindau et al. Fusion Eng. Des. 75 - 79 (2005) 989]. This type of material allows higher temperature performance (650 o C) than standard RAFM steels and shows improved mechanical properties like superior tensile and creep properties in comparison to the base material EUROFER [R. Lindau, A. Moeslang, M. Schirra, P. Schlossmacher, M. Klimenkov, J. Nucl. Mater. 307-311 (2002) 769]. Together with mechanical and activation properties, the characterization of hydrogen isotope transport properties in any fusion technology material is compulsory because they affect important issues of the blanket concept using a specific collection of materials, such as the fuel economy, plasma stability and the radiological security of the fusion reactor. The hydrogen interaction properties of permeability, diffusivity and Sieverts' constant in ODS-EUROFER are experimentally evaluated by using the gas evolution permeation technique. The results are analysed together with the properties of the base material in order to study the influence of the particular microstructure of ODS in the hydrogen transport. Higher permeability of hydrogen in ODS-EUROFER has been obtained in comparison to the base material EUROFER. The effect of trapping showing a high time lag for non steady-state permeation has been noticed in the low temperature range. The trapping phenomena is identified to be the cause of such effect and the presence of nanoparticles of Yttria the reason for the source of additional trapping sites. The concluding remark is a decrease in the diffusivity and an increase in the solubility of hydrogen in the material at low temperature. All the hydrogen transport parameters obtained for ODS-EUROFER are compared to the properties of base material and available data corresponding to other RAFM steels of the same kind. (author)

  16. Radiation-induced desulfurization of Arabian crude oil and straight-run diesel

    Science.gov (United States)

    Basfar, A. A.; Mohamed, K. A.

    2011-11-01

    Radiation-induced desulfurization of four types of Arabian crude oils (heavy, medium, light and extra light) and straight-run diesel (SRD) was investigated over the range of 10-200 kGy. Results show that gamma radiation processing at absorbed doses up to 200 kGy without further treatment is not sufficient for desulfurization. However, the combination of gamma-irradiation with other physical/chemical processes (i.e. L/L extraction, adsorption and oxidation) may be capable of removing considerable levels of sulfur compounds in the investigated products. Currently, this approach of combined radiation/physical/chemical processes is under investigation. The findings of these attempts will be reported in the future.

  17. Boosting the IGCLC process efficiency by optimizing the desulfurization step

    International Nuclear Information System (INIS)

    Hamers, H.P.; Romano, M.C.; Spallina, V.; Chiesa, P.; Gallucci, F.; Sint Annaland, M. van

    2015-01-01

    Highlights: • Pre-CLC hot gas desulfurization and post-CLC desulfurization are assessed. • Process efficiency increases by 0.5–1% points with alternative desulfurization methods. • Alternative desulfurization methods are more beneficial for CFB configurations. - Abstract: In this paper the influence of the desulfurization method on the process efficiency of an integrated gasification chemical-looping combustion (IGCLC) systems is investigated for both packed beds and circulating fluidized bed CLC systems. Both reactor types have been integrated in an IGCLC power plant, in which three desulfurization methods have been compared: conventional cold gas desulfurization with Selexol (CGD), hot gas desulfurization with ZnO (HGD) and flue gas desulfurization after the CLC reactors (post-CLC). For CLC with packed bed reactors, the efficiency gain of the alternative desulfurization methods is about 0.5–0.7% points. This is relatively small, because of the relatively large amount of steam that has to be mixed with the fuel to avoid carbon deposition on the oxygen carrier. The HGD and post-CLC configurations do not contain a saturator and therefore more steam has to be mixed with a negative influence on the process efficiency. Carbon deposition is not an issue for circulating fluidized bed systems and therefore a somewhat higher efficiency gain of 0.8–1.0% point can be reached for this reactor system, assuming that complete fuel conversion can be reached and no sulfur species are formed on the solid, which is however thermodynamically possible for iron and manganese based oxygen carriers. From this study, it can be concluded that the adaptation of the desulfurization method results in higher process efficiencies, especially for the circulating fluidized bed system, while the number of operating units is reduced.

  18. Investigation of microstructure changes in ODS-EUROFER after hydrogen loading

    International Nuclear Information System (INIS)

    Emelyanova, O.V.; Ganchenkova, M.G.; Malitskii, E.; Yagodzinskyy, Y.N.; Klimenkov, M.; Borodin, V.A.; Vladimirov, P.V.; Lindau, R.; Möslang, A.; Hänninen, H.

    2016-01-01

    The effect of hydrogen on the microstructure of mechanically tested ODS-EUROFER steel was investigated by means of transmission electron microscopy, thermal desorption spectroscopy, and atomistic simulations. The presence of yttrium oxide particles notably increases hydrogen uptake in ODS-EUROFER steel as compared to ODS-free EUROFER 97. Under tensile loading, hydrogen accumulation promotes the loss of cohesion at the oxide particle interfaces. First-principles molecular dynamics simulations indicate that hydrogen can be trapped at nanoparticle/matrix interface, creating OH-groups. The accumulation of hydrogen atoms at the oxide particle surface can be the reason for the observed hydrogen-induced oxide/matrix interface weakening and de-cohesion under the action of external tensile stress.

  19. Effects of manufacturing process on impact properties and microstructures of ODS steels

    Energy Technology Data Exchange (ETDEWEB)

    Tanno, Takashi, E-mail: tanno.takashi@jaea.go.jp; Ohtsuka, Satoshi; Yano, Yasuhide; Kaito, Takeji; Tanaka, Kenya

    2014-12-15

    Oxide dispersion strengthened (ODS) steels are notable advanced alloys with durability to a high-temperature and high-dose neutron irradiation environment because of their good swelling resistance and mechanical properties under neutron irradiation. 9–12Cr-ODS martensite steels have been developed in the Japan Atomic Energy Agency as the primary candidate material for the fast reactor fuel cladding tubes. They would also be good candidates for the fusion reactor blanket material which is exposed to high-dose neutron irradiation. In this work, modification of the manufacturing process of 11Cr-ODS steel was carried out to improve its impact property. Two types of 11Cr-ODS steels were manufactured: pre-mix and full pre-alloy ODS steels. Miniature Charpy impact tests and metallurgical observations were carried out on these steels. The impact properties of full pre-alloy ODS steels were shown to be superior to those of pre-mix ODS steels. It was demonstrated that the full pre-alloy process noticeably improved the microstructure homogeneity (i.e. reduction of inclusions and pores)

  20. Liquefaction and desulfurization of coal using synthesis gas

    Science.gov (United States)

    Fu, Yuan C.

    1977-03-08

    A process for desulfurizing and liquefying coal by heating said coal at a temperature of 375.degree.-475.degree. C in the presence of a slurry liquid, hydrogen, carbon monoxide, steam, and a catalyst comprising a desulfurization catalyst and an alkali metal salt.

  1. Microstructural characterization of ODS ferritic steels at different processing stages

    Energy Technology Data Exchange (ETDEWEB)

    Gil, E., E-mail: egil@ceit.es; Ordás, N.; García-Rosales, C.; Iturriza, I., E-mail: iiturriza@ceit.es

    2015-10-15

    Highlights: • ODS ferritic stainless steel produced by new route without mechanical alloying. • Fully dense ferritic stainless steels containing Y and Ti were obtained by HIPping. • Y and Ti-rich precipitates prevent grain growth during heat treatment up to 1320 °C. • HIPping at 1220 °C dissolves the metastable oxides on PPBs. - Abstract: Nanostructured Oxide Dispersion Strengthened Reduced Activation Ferritic Stainless Steels (ODS RAF) are promising structural materials for fusion reactors, due to their ultrafine microstructure and the presence of a dispersion of Y–Ti–O nanoclusters that provide excellent creep strength at high temperatures (up to 750 °C). The traditional powder metallurgical route to produce these steels is based on Gas Atomization (GA) + Mechanical Alloying (MA) + HIP + ThermoMechanical Treatments (TMTs). Recently, alternative methods have arisen to avoid the MA step. In line with this new approach, ferritic stainless steel powders were produced by gas atomization and HIPped, after adjusting their oxygen, Y and Ti contents to form Y–Ti–O nanoclusters during subsequent heat treatments. The microstructure of as-HIPped steels mainly consists of ferrite grains, Y–Ti precipitates, carbides and oxides on Prior Particle Boundaries (PPBs). Post-HIP heat treatments performed at high temperatures (1270 and 1300 °C) evaluated the feasibility of achieving a complete dissolution of the oxides on PPBs and a precipitation of ultrafine Ti- and Y-rich oxides in the Fe14Cr2W matrix. FEG-SEM with extensive EDS analysis was used to characterize the microstructure of the atomized powders and the ODS-RAF specimens after HIP consolidation and post-HIP heat treatments. A deeper characterization of atomized powder was carried out by TEM.

  2. Advances on simultaneous desulfurization and denitrification using activated carbon irradiated by microwaves.

    Science.gov (United States)

    Ma, Shuang-Chen; Gao, Li; Ma, Jing-Xiang; Jin, Xin; Yao, Juan-Juan; Zhao, Yi

    2012-06-01

    This paper describes the research background and chemistry of desulfurization and denitrification technology using microwave irradiation. Microwave-induced catalysis combined with activated carbon adsorption and reduction can reduce nitric oxide to nitrogen and sulfur dioxide to sulfur from flue gas effectively. This paper also highlights the main drawbacks of this technology and discusses future development trends. It is reported that the removal of sulfur dioxide and nitric oxide using microwave irradiation has broad prospects for development in the field of air pollution control.

  3. Magnesite base desulfurizer of metallurgical physical chemistry research

    Directory of Open Access Journals (Sweden)

    G. D. Liu

    2017-01-01

    Full Text Available This topic put carbon thermal vacuum method in combination with magnesium based desulfurization technology with magnesite reduction of magnesium vapor directly on hot metal desulphurization. This is a new type of desulfurization technology, the retrieval related literature at home and abroad was not reported in the recent ten years, according to the relationship between heat of desulfurizer preparation MgO style content can reach 50 %.It was found that the desulfurizer sample with 50 % MgO content was in accordance with the requirements, without adding flux, but its viscosity did not meet the requirements; adding 1 % flux (CaF2, the sample viscosity was significantly reduced, and about 1 400 °C sample viscosity suitable for hot metal pretreatment desulfurization.

  4. Influence of Zr addition on the microstructures and mechanical properties of 14Cr ODS steels

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Liye [State Key Lab of Hydraulic Engineering Simulation and Safety, Tianjin key Lab of Composite and Functional Materials, Tianjin University, Tianjin 300072 (China); Yu, Liming, E-mail: lmyu@tju.edu.cn [State Key Lab of Hydraulic Engineering Simulation and Safety, Tianjin key Lab of Composite and Functional Materials, Tianjin University, Tianjin 300072 (China); Liu, Yongchang; Liu, Chenxi; Li, Huijun [State Key Lab of Hydraulic Engineering Simulation and Safety, Tianjin key Lab of Composite and Functional Materials, Tianjin University, Tianjin 300072 (China); Wu, Jiefeng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2017-05-17

    Oxide dispersion strengthened (ODS) steel is one of the most promising candidate structural materials for the high-temperature nuclear reactor application. In this study, two compositions of ODS steels (14Cr-ODS and 14Cr-Zr-ODS) were prepared to investigate the influence of Zr addition on the microstructures and mechanical properties of ODS steels. The microstructures, including dispersion morphology and crystal structures of oxide particles, particle-matrix interface coherency and particle-dislocation interactions, were characterized using TEM, HRTEM, and SEM, and the mechanical properties at room and high temperatures were measured using uniaxial tensile tests. Results show that Zr addition leads to the formation of finer precipitated particles, which was identified as rhombohedral Y{sub 4}Zr{sub 3}O{sub 12}, with denser dispersion in the matrix. The calculation results reveal that the lattice misfit, δ, at the interface between particle and matrix increases as the particle size increases. In addition, the strength and elongation of ODS steels are improved with Zr addition due to the stronger interface bonding force between fine particles and matrix as well as the larger pinning effect of small particles to dislocation movements.

  5. High resolution SEM characterization of nano-precipitates in ODS steels.

    Science.gov (United States)

    Jóźwik, Iwona; Strojny-Nędza, Agata; Chmielewski, Marcin; Pietrzak, Katarzyna; Kurpaska, Łukasz; Nosewicz, Szymon

    2018-05-01

    The performance of the present-day scanning electron microscopy (SEM) extends far beyond delivering electronic images of the surface topography. Oxide dispersion strengthened (ODS) steel is on of the most promising materials for the future nuclear fusion reactor because of its good radiation resistance, and higher operation temperature up to 750°C. The microstructure of ODS should not exceed tens of nm, therefore there is a strong need in a fast and reliable technique for their characterization. In this work, the results of low-kV SEM characterization of nanoprecipitates formed in the ODS matrix are presented. Application of highly sensitive photo-diode BSE detector in SEM imaging allowed for the registration of single nm-sized precipitates in the vicinity of the ODS alloys. The composition of the precipitates has been confirmed by TEM-EDS. © 2018 Wiley Periodicals, Inc.

  6. Desulfurization of chemical waste gases and flue gases with economic utilization of air pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Asperger, K.; Wischnewski, W.

    1983-09-01

    The technological state of recovery of sulfur dioxide from waste and flue gases in the GDR is discussed. Two examples of plants are presented: a pyrosulfuric acid plant in Coswig, recovering sulfur dioxide from gases by absorption with sodium hydroxide, followed by catalytic oxidation to sulfur trioxide, and a plant for waste sulfuric acid recovery from paraffin refining, where the diluted waste acid is sprayed into a furnace and recovered by an ammonium-sulfite-bisulfite solution from the combustion gas (with 4 to 10% sulfur dioxide content). Investment and operation costs as well as profits of both plants are given. Methods employed for power plant flue gas desulfurization in major industrial countries are further assessed: about 90% of these methods uses wet flue gas scrubbing with lime. In the USA flue gas from 25,000 MW of power plant capacity is desulfurized. In the USSR, a 35,000 m/sup 3//h trial plant at Severo-Donetzk is operating using lime, alkali and magnesite. At the 150 MW Dorogobush power plant in the USSR a desulfurization plant using a cyclic ammonia process is under construction.

  7. Effects of nano-TiO2 on combustion and desulfurization

    International Nuclear Information System (INIS)

    Zhao, Yi; Wang, Shuqin; Shen, Yanmei; Lu, Xiaojuan

    2013-01-01

    Nanosized titanium oxide powder was prepared via the sol–gel process and characterized by transmission electron microscope. The effects of nano-TiO 2 on combustion characteristics of lignite, desulfurization in combustion and the properties of ashes were investigated. The calorific value of coals and the fusion point of the coal ashes were measured by calorimeter and ash fusion point determination meter; the components of coal ashes and the contents of combustible matters in ash were determined by chemical methods; the pore-size distribution and specific surface area of the coal ash were analyzed by surface area analyzer. A thermogravimetric analyzer was used to investigate the effect of nano-TiO 2 on combustion. The results showed that the calorific value of the coal and the fusion temperature of the coal ash were lowered by adding CaO, while on the other hand adding nano-TiO 2 to coal increased the calorific value and the melting temperature effectively. Meanwhile, the coal combustion efficiency and desulfurization in combustion could be effectively improved by the co-action of TiO 2 . - Highlights: • The burn-off rate of coals was raised and the combustible contents were reduced by adding nano-TiO 2 . • The desulfurization in combustion can be achieved by adding CaO, but the combustion efficiency was inhibited. • Nano-TiO 2 can promote the transfer rate of oxygen from gas phase to the surface of char

  8. Effects of magnetic fields on improving mass transfer in flue gas desulfurization using a fluidized bed

    Science.gov (United States)

    Zhang, Qi; Gui, Keting; Wang, Xiaobo

    2016-02-01

    The effects of magnetic fields on improving the mass transfer in flue gas desulfurization using a fluidized bed are investigated in the paper. In this research, the magnetically fluidized bed (MFB) is used as the reactor in which ferromagnetic particles are fluidized with simulated flue gas under the influence of an external magnetic field. Lime slurry is continuously sprayed into the reactor. As a consequence, the desulfurization reaction and the slurry drying process take place simultaneously in the MFB. In this paper, the effects of ferromagnetic particles and external magnetic fields on the desulphurization efficiency are studied and compared with that of quartz particles as the fluidized particles. Experimental results show that the ferromagnetic particles not only act as a platform for lime slurry to precipitate on like quartz particles, but also take part in the desulfurization reaction. The results also show that the specific surface area of ferromagnetic particles after reaction is enlarged as the magnetic intensity increases, and the external magnetic field promotes the oxidation of S(IV), improving the mass transfer between sulphur and its sorbent. Hence, the efficiency of desulphurization under the effects of external magnetic fields is higher than that in general fluidized beds.

  9. Enhancing mercury removal across air pollution control devices for coal-fired power plants by desulfurization wastewater evaporation.

    Science.gov (United States)

    Bin, Hu; Yang, Yi; Cai, Liang; Yang, Linjun; Roszak, Szczepan

    2017-10-09

    Desulfurization wastewater evaporation technology is used to enhance the removal of gaseous mercury (Hg) in conventional air pollution control devices (APCDs) for coal-fired power plants. Studies have affirmed that gaseous Hg is oxidized and removed by selective catalytic reduction (SCR), an electrostatic precipitator (ESP) and wet flue gas desulfurization (WFGD) in a coal-fired thermal experiment platform with WFGD wastewater evaporation. Effects of desulfurization wastewater evaporation position, evaporation temperature and chlorine ion concentration on Hg oxidation were studied as well. The Hg 0 oxidation efficiency was increased ranging from 30% to 60%, and the gaseous Hg removal efficiency was 62.16% in APCDs when wastewater evaporated before SCR. However, the Hg 0 oxidation efficiency was 18.99% and the gaseous Hg removal efficiency was 40.19% in APCDs when wastewater evaporated before ESP. The results show that WFGD wastewater evaporation before SCR is beneficial to improve the efficiency of Hg oxidized and removed in APCDs. Because Hg 2+ can be easily removed in ACPDs and WFGD wastewater in power plants is enriched with chlorine ions, this method realizes WFGD wastewater zero discharge and simultaneously enhances Hg removal in APCDs.

  10. Microstructural evolution in friction stir welding of nanostructured ODS alloys

    International Nuclear Information System (INIS)

    Chen, C.-L.; Tatlock, G.J.; Jones, A.R.

    2010-01-01

    Nanostructured oxide dispersion strengthened (ODS) Fe-based alloys manufactured by mechanical alloying (MA) are generally considered to be promising candidate materials for high-temperature applications up to at least 1100 o C because of their excellent creep strength and good oxidation resistance. However, a key issue with these alloys is the difficulty in using fusion welding techniques to join components due to oxide particle agglomeration and loss in the weld zone and the disruption and discontinuity in the grain structure introduced at the bond. In this study, the evolution of microstructure has been comprehensively studied in friction stir welds in a ferritic ODS alloy. Initially, electron backscattering diffraction (EBSD) was used to analyze the grain orientation, the grain boundary geometries and recrystallization behaviour. It suggested that deformation heterogeneities were introduced during the friction stirring process which facilitated the onset of recrystallization. Transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) were used to observe the effects of the friction stir welding (FSW) process on the grain structure and the distribution of Y 2 O 3 and other particles in the metal substrates in the FSW and adjacent regions, after the alloys had been recrystallized at temperatures up to 1380 o C for 1 h in air. The results show that fine-equiaxed grains and a uniform distribution of oxide particles were present in the friction stirred region but that the grain boundaries in the parent metal were pinned by particles. Friction stirring appeared to release these boundaries and allowed secondary recrystallization to occur after further heat treatment. The FSW process appears to be a promising technique for joining ferritic ODS alloys in the form of sheet and tube.

  11. Desulfurization Sorbents for Transport-Bed Applications

    International Nuclear Information System (INIS)

    Gupta, Raghubir P.; Turk, Brian S.; Vierheilig, Albert A.

    1997-01-01

    This project extends the prior work on the development of fluidizable zinc titanate particles using a spray-drying technique to impart high reactivity and attrition resistance. The specific objectives are: (1) To develop highly reactive and attrition-resistant zinc titanate sorbents in 40- to 150-(micro)m particle size range for transport reactor applications; (2) To transfer sorbent production technology to private sector; and (3) To provide technical support to Sierra Pacific Clean Coal Technology Demonstration plant and FETC's Hot-Gas Desulfurization Process Development Unit (PDU), both employing a transport reactor system

  12. Initial Development in Joining of ODS Alloys Using Friction Stir Welding

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Weiju [ORNL; Feng, Zhili [ORNL

    2007-08-01

    Solid-state welding of oxide-dispersion-strengthened (ODS) alloy MA956 sheets using friction stir welding (FSW) was investigated. Butt weld was successfully produced. The weld and base metals were characterized using optical microscopy, scanning electronic microscopy, transmission electronic microscopy, and energy dispersion x-ray spectrum. Microhardness mapping was also conducted over the weld region. Analyses indicate that the distribution of the strengthening oxides was preserved in the weld. Decrease in microhardness of the weld was observed but was insignificant. The preliminary results seem to confirm the envisioned feasibility of FSW application to ODS alloy joining. For application to Gen IV nuclear reactor heat exchanger, further investigation is suggested.

  13. Influence of the fabrication process parameters on microstructures and mechanical properties of 10Cr-1Mo ODS steel

    International Nuclear Information System (INIS)

    Jin, Hyun Ju; Kim, Ki Baik; Choi, Byoung Kwon; Kang, Suk Hoon; Noh, Sang Hoon; Kim, Ga Eon; Kim, Tae Kyu

    2016-01-01

    Oxide dispersion strengthened (ODS) FM steels have been developed as the most promising core structural material for high- temperature components operating in severe environments such as nuclear fusion and fission systems owing to its excellent elevated temperature strength and radiation resistance stemming from the addition of extremely thermally stable oxide particles dispersed in a ferritic/martensitic matrix. To realize the structural components such as plates, sheets and tubes in SFR, the development of manufacturing processes is an essential issue for the ODS FM steel. While the ODS steel has superior radiation resistance and high temperature strength, in comparison with the existing commercial steels, it is difficult for the ODS steel to obtain sufficient workability for the fabrication due to high hardness and low ductility at room temperature, meaning that the manufacturing of the ODS plate including cladding tube can be complicated by the low cold workability. In order to prevent the ODS steel from any damage during the manufacturing process, thus, the introduction of intermediate heat treatments between cold rolling processes is necessary. This study investigates effects of the fabrication process parameters such as the cold working ratio, the intermediate and final heat treatments on the microstructure and mechanical properties of 10Cr-1Mo ODS steel. In an effort to optimize the manufacturing route of the ODS FM steel, the microstructural and mechanical evolutions for the ODS plate manufactured by a control of the fabrication process parameters were evaluated in the present study. In the present study, the effect of a cold rolling and intermediate heat treatments on microstructures and mechanical properties of 10Cr-1Mo FM ODS steel were investigated. During the manufacturing route the hardness measurements remained below the critical value of 400 Hv. Intermediate heat treatment with slow cooling led to a softened ferritic structures which can be further

  14. Relationship between microstructure and mechanical properties in ODS materials for nuclear application

    International Nuclear Information System (INIS)

    De Carlan, Y.

    2013-01-01

    Oxide Dispersion Strengthened ferritic/martensitic alloys are developed as prospective cladding materials for future Sodium-Cooled-Fast-Reactors (GEN IV) [1]. These advanced alloys present a good resistance to irradiation and a high creep rupture strength due to a reinforcement by the homogeneous dispersion of hard nano-sized particles (such as Y 2 O 3 or YTiO). ODS alloys are elaborated by powder metallurgy, consolidated by hot extrusion and manufactured into cladding tube using the Pilger cold-rolling process [2, 3]. ODS alloys present usually low ductility and high hardness. The aim of this talk is to present the specificity of the metallurgy of ODS materials in relationship with the main mechanical properties (tensile and creep properties, toughness, transition temperature). Two types of alloys will be presented: Fe-9Cr martensitic ODS and Fe-14Cr ferritic ODS alloys. Mechanical properties of the materials depend on the metallurgical state (fine grains, recrystallized, martensitic) and very different behaviors are observed as a function of final microstructure. For example, for a Fe-9Cr ODS alloy, tempered martensite lets obtaining material with high strength whereas softened ferrite see figure 1 [4] tolerates high deformation levels. (authors)

  15. GE`s worldwide experience with IFO based gypsum producing flue gas desulfurization systems

    Energy Technology Data Exchange (ETDEWEB)

    Saleem, A. [GE Environmental Systems, Lebanon, PA (United States)

    1994-12-31

    The In-Situ Forced Oxidation (IFO) process to produce gypsum in a commercial scale flue gas desulfurization (FGD) system was first demonstrated by GE Environmental Systems in 1980 at the Monticello Generating Station of Texas Utilities. Since then, the IFO technology developed and demonstrated by GE has become the industry standard and is used extensively on a world-wide basis to produce both commercial and disposable-grade gypsum. The paper gives an overview of the development, demonstration, commercial design and current status of the IFO technology.

  16. Characterization of precipitates in nano structured 14% Cr ODS alloys for fusion application

    International Nuclear Information System (INIS)

    He, P.; Klimenkov, M.; Lindau, R.; Möslang, A.

    2012-01-01

    Highlights: ► We examine Ti influence on microstructure and mechanical properties of ODS steels. ► Ti addition leads to bimodal grain size distribution. ► The formation of Ti oxide and Y–Ti–O particles is observed in Ti-containing steels. ► The best nanoparticle refinement and tensile strength are obtained with 0.3% Ti. ► Ti exhibits adverse effect on the Charpy impact property. - Abstract: Oxide dispersion strengthened (ODS) reduced activation ferritic (RAF) steels, have been considered as promising materials for application in fusion power reactors up to about 750 °C. Four ODS RAF steels, with compositions of Fe–13.5Cr–2W–(0–0.2–0.3–0.4)Ti–0.3Y 2 O 3 (in wt.%) were produced by powder metallurgy technique. For the different Ti-contents, the correlation between microstructure and mechanical properties was analyzed by means of scanning electron microscope (SEM) and transmission electron microscope (TEM) equipped with energy- dispersive X-ray spectrometer (EDX) and electron energy loss spectrometer (EELS). A bimodal grain size distribution was observed in all as-hipped Ti-containing ODS alloys. These alloys consisted of coarse grains typical ranging from 1 μm to 8 μm and fine grains well below 1 μm in diameter. The addition of Ti resulted in the formation of spherical Ti oxides rather than Cr oxides owing to the stronger affinity of Ti. The influence of Ti on particle size refinement was striking and the optimum effect was obtained when adding 0.3% Ti. Generally the hardness increased consistently with increasing in Ti content. The ODS alloying with 0.3% Ti exhibit the highest strength due to the optimum refinement of mean ODS particle size.

  17. Characterization of Nano Sized Microstructures in Fe and Ni Base ODS Alloys Using Small Angle Neutron Scattering

    International Nuclear Information System (INIS)

    Han, Young-Soo; Jang, Jin-Sung; Mao, Xiaodong

    2015-01-01

    Ferritic ODS(Oxide-dispersion-strengthened) alloy is known as a primary candidate material of the cladding tubes of a sodium fast reactor (SFR) in the Generation IV research program. In ODS alloy, the major contribution to the enhanced high-temperature mechanical property comes from the existence of nano-sized oxide precipitates, which act as obstacles to the movement of dislocations. In addition for the extremely high temperature application(>950 .deg. C) of future nuclear system, Ni base ODS alloys are considered as candidate materials. Therefore the characterization of nano-sized microstructures is important for determining the mechanical properties of the material. Small angle neutron scattering (SANS) technique non-destructively probes structures in materials at the nano-meter length of scale (1 - 1000 nm) and has been a very powerful tool in a variety of scientific/engineering research areas. In this study, nano-sized microstructures were quantitatively analyzed by small angle neutron scattering. Quantitative microstructural information on nanosized oxide in ODS alloys was obtained from SANS data. The effects of the thermo mechanical treatment on the size and volume fraction of nano-sized oxides were analyzed. For 12Cr ODS alloy, the experimental A-ratio is two-times larger than the theoretical A-ratio., and this result is considered to be due to the imperfections included in YTaO 4 . For Ni base ODS alloy, the volume fraction of the mid-sized particles (- 30 nm) increases rapidly as hot extrusion temperature decreases

  18. Desulfurization of petroleum induced by ionization radiation: benzothiophene behavior

    International Nuclear Information System (INIS)

    Andrade, Luana S.; Calvo, Wilson A.P.; Duarte, Celina L.

    2013-01-01

    Hydrodesulfurization (HDS) is currently the most common method used by refineries; this removes significantly sulfur compounds from petroleum fractions, however, is not highly effective for removing thiophene compounds such as benzothiophene, and generates high costs for the oil industry. Another factor, are the environmental laws, which over the years has become increasingly strict, especially regarding the sulfur content. This compound cause incalculable damage both to the industry and to the environment. Therefore new methods for petroleum desulfurization should be studied in order to minimize the impacts that these compounds cause. In the present study it was used ionizing radiation, a promising method of advanced oxidation in reducing sulfur compounds. The analysis were performed after purge and trap concentration of samples, followed by gas chromatography-mass spectrometry (GC-MS). Then benzothiophene samples with the same concentration from 27 mg.L -1 to 139 mg.L -1 were irradiated with different absorbed doses of radiation ranging from 1 kGy to 20 kGy in gamma irradiator Cobalt-60, Gammacell. These samples were analyzed by the same procedure used for the calibration curve, and the removals of benzothiophene after ionizing radiation treatment were calculated. It was observed that at higher doses there was a greater degradation of this compound and the formation of fragments, such as 1,2-dimethylbenzene and toluene, which may be removed by simple processes. (author)

  19. Optimisation of Experimental Conditions for Ex-Bed Desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, J. M.; Ruiz, E.; Otero, J.

    2010-12-22

    This report compiles the results of the work conducted by CIEMAT for Task 6.3 Sulfur and Nitrogen Compounds Abatement of the FLEXGAS project Near Zero Emission Advanced Fluidized Bed Gasification, which has been carried out with financial support from the Research Fund for Coal and Steel, RFCR-CT-2007-00005. The assignment of CIEMAT in Task 6.3 has dealt with the experimental study of ex-bed desulfurization at high temperature and high pressure. Based on a review of the state of the art, a zinc oxide sorbent was chosen as a promising candidate for bulk sulfur removal in highly reducing gases such as those from coal and waste oxygen gasification or for a polishing stage in low sulfur content gases, which is typically the case in biomass gasification gases. The work accomplished has included the study of the sulfidation and regeneration stages in order to determine successful operating conditions and the assessment of the long term performance of the sorbent over subsequent sulfidation and regeneration cycles. (Author) 36 refs.

  20. Precipitates and boundaries interaction in ferritic ODS steels

    Energy Technology Data Exchange (ETDEWEB)

    Sallez, Nicolas, E-mail: nicolas.sallez@simap.grenoble-inp.fr [Univ. Grenoble Alpes, SIMAP, F-38000 Grenoble (France); Hatzoglou, Constantinos [Groupe de Physique des Matériaux, Université et INSA de Rouen, UMR CNRS 6634, Normandie Université (France); Delabrouille, Fredéric [EDF–EDF R& D, Les Renardières, 77818 Moret-sur-Loing (France); Sornin, Denis; Chaffron, Laurent [CEA, DEN, Service de Recherches Métallurgiques Appliqué, 91191 Gif-sur-Yvette (France); Blat-Yrieix, Martine [EDF–EDF R& D, Les Renardières, 77818 Moret-sur-Loing (France); Radiguet, Bertrand; Pareige, Philippe [Groupe de Physique des Matériaux, Université et INSA de Rouen, UMR CNRS 6634, Normandie Université (France); Donnadieu, Patricia; Bréchet, Yves [Univ. Grenoble Alpes, SIMAP, F-38000 Grenoble (France)

    2016-04-15

    In the course of a recrystallization study of Oxide Dispersion Strengthened (ODS) ferritic steels during extrusion, particular interest was paid to the (GB) Grain Boundaries interaction with precipitates. Complementary and corresponding characterization experiments using Transmission Electron Microscopy (TEM), Energy Dispersive X-ray spectroscopy (EDX) and Atom Probe Tomography (APT) have been carried out on a voluntarily interrupted extrusion or extruded samples. Microscopic observations of Precipitate Free Zones (PFZ) and precipitates alignments suggest precipitate interaction with migrating GB involving dissolution and Oswald ripening of the precipitates. This is consistent with the local chemical information gathered by EDX and APT. This original mechanism for ODS steels is similar to what had been proposed in the late 80s for similar observation made on Ti alloys reinforced by nanosized yttrium oxides: An interaction mechanism between grain boundaries and precipitates involving a diffusion controlled process of precipitates dissolution at grain boundaries. It is believed that this mechanism can be of primary importance to explain the mechanical behaviour of such steels. - Highlights: • To study the microstructural evolution of a ferritic ODS steel during its extrusion, observations have been carried on samples resulting from a voluntarily interrupted extrusion and extruded materials. • A highly heterogeneous precipitate population have been observed. Nanosized coherent precipitates (2–5 nm) on both sides of the grain boundaries despite grain boundary migration after precipitation due to further thermo-mechanical processing as well as coarse precipitates (10–40 nm) alignments are observed on the grain boundaries and within the grains, parallel to the grain boundaries. • Asymmetrical PFZs can be observed around precipitates alignments and grain boundaries. Using TEM with EDX and APT we have been able to ensure that the PFZs are chemically depleted.

  1. HRTEM Study of the Role of Nanoparticles in ODS Ferritic Steel

    Energy Technology Data Exchange (ETDEWEB)

    Hsiung, L; Tumey, S; Fluss, M; Serruys, Y; Willaime, F

    2011-08-30

    Structures of nanoparticles and their role in dual-ion irradiated Fe-16Cr-4.5Al-0.3Ti-2W-0.37Y{sub 2}O{sub 3} (K3) ODS ferritic steel produced by mechanical alloying (MA) were studied using high-resolution transmission electron microscopy (HRTEM) techniques. The observation of Y{sub 4}Al{sub 2}O{sub 9} complex-oxide nanoparticles in the ODS steel imply that decomposition of Y{sub 2}O{sub 3} in association with internal oxidation of Al occurred during mechanical alloying. HRTEM observations of crystalline and partially crystalline nanoparticles larger than {approx}2 nm and amorphous cluster-domains smaller than {approx}2 nm provide an insight into the formation mechanism of nanoparticles/clusters in MA/ODS steels, which we believe involves solid-state amorphization and re-crystallization. The role of nanoparticles/clusters in suppressing radiation-induced swelling is revealed through TEM examinations of cavity distributions in (Fe + He) dual-ion irradiated K3-ODS steel. HRTEM observations of helium-filled cavities (helium bubbles) preferably trapped at nanoparticle/clusters in dual-ion irradiated K3-ODS are presented.

  2. Creep constitutive equation of dual phase 9Cr-ODS steel

    International Nuclear Information System (INIS)

    Sakasegawa, Hideo; Ukai, Shigeharu; Tamura, Manabu; Ohtsuka, Satoshi; Tanigawa, Hiroyasu; Ogiwara, Hiroyuki; Kohyama, Akira; Fujiwara, Masayuki

    2008-01-01

    9Cr-ODS (oxide dispersion strengthened) steels developed by JAEA (Japan Atomic Energy Agency) have superior creep properties compared with conventional heat resistant steels. The ODS steels can enormously contribute to practical applications of fast breeder reactors and more attractive fusion reactors. Key issues are developments of material processing procedures for mass production and creep life prediction methods in present R and D. In this study, formulation of creep constitutive equation was performed against the backdrop. The 9Cr-ODS steel displaying an excellent creep property is a dual phase steel. The ODS steel is strengthened by the δ ferrite which has a finer dispersion of oxide particles and shows a higher hardness than the α' martensite. The δ ferrite functions as a reinforcement in the dual phase 9Cr-ODS steel. Its creep behavior is very unique and cannot be interpreted by conventional theories of heat resistant steels. Alternative qualitative model of creep mechanism was formulated at the start of this study using the results of microstructural observations. Based on the alternative creep mechanism model, a novel creep constitutive equation was formulated using the exponential type creep equation extended by a law of mixture

  3. Hardness distribution and effect of irradiation in FSW-ODS ferritic steels

    International Nuclear Information System (INIS)

    Noh, Sanghoon; Kasada, Ryuta; Kimura, Akihiko; Nagasaka, Takuya; Sokolov, M.A.; Yamamoto, T.

    2014-01-01

    Oxide dispersion strengthened ferritic steels (ODS-FS) have been considered as one of the most promising structural materials for advanced nuclear systems such as fusion reactors and next generation fission reactors, because of its excellent elevated temperature strength, corrosion and radiation resistance. Especially, irradiation resistance is a critical issue for the high performance of ODS-FS. In this study, effects of the irradiation on hardness properties of friction stri processed (FSP) ODS-FS were investigated. FSP technique was employed on ODS-FS. A plate specimen was cut out from the cross section and irradiated to 1.2 dpa at 573K in the High Flux Isotope Reactor (HFIR). To investigate the effect of neutron irradiation on processed area, the hardness distributions were evaluated on the cross section. Hardness of FSP ODS-FS was various with each microstructure after irradiation to 1.2 dpa at 573K. The increase of Vickers hardness was significant in the stirred zone and heat affected zone. Base material exhibited the lowest hardening about 38HV. Since nano-oxide particles in stirred zone showed identical mean diameter and number density, it is considered that hardening differences between stirred zone and base material is due to differences in initial dislocation density. (author)

  4. On the high-temperature desulfurization of coal gas: The development of a regenerable absorbent

    Energy Technology Data Exchange (ETDEWEB)

    Van Yperen, Renee

    1994-05-18

    There is actually no solid absorbent based on bulk metal oxides available that meets the conditions for application in high-temperature desulfurization processes. This research was aimed to develop an absorbent that fulfills all the specifications for employment in hot-gas clean up. Chapter 2 deals with the development of amorphous aluminium phosphate as a support material. The influence of the preparation conditions onto the specific surface area, pore structure, thermal and chemical stability, and acidity of amorphous aluminium phosphate was investigated. The application of iron oxide onto amorphous aluminium phosphate by means of deposition-precipitation from a homogeneous solution is discussed in chapter 3. The influence of amorphous aluminium phosphate onto the stability, activity, and capacity of the iron oxide is described in detail. Chapter 4 surveys the activity and capacity of several active materials in the absorption of hydrogen sulphide. It is shown that the most promising active material is a mixture of iron oxide and molybdenum oxide. In chapter 5 the properties of iron-molybdenum mixed oxide absorbents are discussed. The effect of the iron to molybdenum ratio onto the formation of iron-(III)-sulphates and the stability of the molybdenum compound is examined. Chapter 6 deals with the preparation of iron-molybdenum mixed oxide absorbents by means of impregnation of modified pre-shaped alumina support bodies. In chapter 7 the effect of the hydrogen and carbon monoxide concentration and in chapter 8 the effect of the water concentration in the coal gas on the activity and the capacity of the iron-molybdenum mixed oxide absorbents is described. Regeneration of the loaded absorbents is an important part of the desulfurization process, dealt with in chapter 9. A number of regeneration procedures have been tested. (Abstract Truncated)

  5. Reduction in Defect Content in ODS Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ritherdon, J.; Jones, A.R.

    2000-02-01

    The work detailed within this report is a continuation of earlier work that was carried out under contract number IDX-SY382V. The earlier work comprised a literature review of the sources and types of defects found principally in Fe-based ODS alloys together with a series of experiments designed to identify defects in ODS Fe{sub 3}Al material and recommend methods of defect reduction. Defects found in the Mechanically Alloyed (MA) ODS Fe{sub 3}Al included regions of incomplete MA, porosity, intrusions and fine-grained stringers. Some defects tended to be found in association with one another e.g. intrusions and fine-grained stringers. Preliminary powder separation experiments were also performed. The scope and objectives of the present work were laid out in the technical proposal ``Reduction in Defect Content in ODS Alloys--II'' which formed the basis of amendment 3 of the current contract. The current studies were devised in the context of the preceding work with a view to extending and concluding certain experiments while exploring new avenues of investigation of defect control and reduction where appropriate. All work proposed was within the context of achieving an ODS Fe{sub 3}Al alloy of improved overall quality and potential creep performance (particularly) in the consolidated, release condition. The interim outturn of the experimental work performed is also reported.

  6. Development of ODS FeCrAl alloys for accident-tolerant fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Dryepondt, Sebastien N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hoelzer, David T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pint, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Unocic, Kinga A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-18

    FeCrAl alloys are prime candidates for accident-tolerant fuel cladding due to their excellent oxidation resistance up to 1400 C and good mechanical properties at intermediate temperature. Former commercial oxide dispersion strengthened (ODS) FeCrAl alloys such as PM2000 exhibit significantly better tensile strength than wrought FeCrAl alloys, which would alloy for the fabrication of a very thin (~250 m) ODS FeCrAl cladding and limit the neutronic penalty from the replacement of Zr-based alloys by Fe-based alloys. Several Fe-12-Cr-5Al ODS alloys where therefore fabricated by ball milling FeCrAl powders with Y2O3 and additional oxides such as TiO2 or ZrO2. The new Fe-12Cr-5Al ODS alloys showed excellent tensile strength up to 800 C but limited ductility. Good oxidation resistance in steam at 1200 and 1400 C was observed except for one ODS FeCrAl alloy containing Ti. Rolling trials were conducted at 300, 600 C and 800 C to simulate the fabrication of thin tube cladding and a plate thickness of ~0.6mm was reached before the formation of multiple edge cracks. Hardness measurements at different stages of the rolling process, before and after annealing for 1h at 1000 C, showed that a thinner plate thickness could likely be achieved by using a multi-step approach combining warm rolling and high temperature annealing. Finally, new Fe-10-12Cr-5.5-6Al-Z gas atomized powders have been purchased to fabricate the second generation of low-Cr ODS FeCrAl alloys. The main goals are to assess the effect of O, C, N and Zr contents on the ODS FeCrAl microstructure and mechanical properties, and to optimize the fabrication process to improve the ductility of the 2nd gen ODS FeCrAl while maintaining good mechanical strength and oxidation resistance.

  7. Aerobic desulfurization of biogas by acidic biotrickling filtration in a randomly packed reactor

    International Nuclear Information System (INIS)

    Montebello, Andrea M.; Mora, Mabel; López, Luis R.; Bezerra, Tercia; Gamisans, Xavier; Lafuente, Javier; Baeza, Mireia; Gabriel, David

    2014-01-01

    Highlights: • Desulfurization of high loads of H 2 S is feasible by acidic biotrickling filtration. • Robustness of the process is demonstrated in the long-term (550 d). • Biosulfur to sulfate oxidation under H 2 S starvation was successfully performed. • Lower sulfate production found at acidic pH compared to that at neutral pH. • Plastic material is recommended for long-term acidic biotrickling filtration. - Abstract: Biotrickling filters for biogas desulfurization still must prove their stability and robustness in the long run under extreme conditions. Long-term desulfurization of high loads of H 2 S under acidic pH was studied in a lab-scale aerobic biotrickling filter packed with metallic Pall rings. Reference operating conditions at steady-state corresponded to an empty bed residence time (EBRT) of 130 s, H 2 S loading rate of 52 g S–H 2 S m −3 h −1 and pH 2.50–2.75. The EBRT reduction showed that the critical EBRT was 75 s and the maximum EC 100 g S–H 2 S m −3 h −1 . Stepwise increases of the inlet H 2 S concentration up to 10,000 ppm v lead to a maximum EC of 220 g S–H 2 S m −3 h −1 . The H 2 S removal profile along the filter bed indicated that the first third of the filter bed was responsible for 70–80% of the total H 2 S removal. The oxidation rate of solid sulfur accumulated inside the bioreactor during periodical H 2 S starvation episodes was verified under acidic operating conditions. The performance under acidic pH was comparable to that under neutral pH in terms of H 2 S removal capacity. However, bioleaching of the metallic packing used as support and chemical precipitation of sulfide/sulfur salts occurred

  8. Thermodynamic Aspects of Gasification Derived Syngas Desulfurization, Removal of Hydrogen Halides and Regeneration of Spent Sorbents Based on La2O3/La2O2CO3 and Cerium Oxides.

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Karel; Leitner, J.; Havlica, Jaromír; Pohořelý, Michael; Brynda, Jiří; Šyc, Michal; Chyou, Y.-P.; Chen, P.-Ch.

    2017-01-01

    Roč. 197, JUN 1 (2017), s. 277-289 ISSN 0016-2361 R&D Projects: GA ČR GC14-09692J Institutional support: RVO:67985858 Keywords : cerium oxides * dehalogenation * thermodynamics Subject RIV: DI - Air Pollution ; Quality OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 4.601, year: 2016

  9. Thermodynamic Aspects of Gasification Derived Syngas Desulfurization, Removal of Hydrogen Halides and Regeneration of Spent Sorbents Based on La2O3/La2O2CO3 and Cerium Oxides.

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Karel; Leitner, J.; Havlica, Jaromír; Pohořelý, Michael; Brynda, Jiří; Šyc, Michal; Chyou, Y.-P.; Chen, P.-Ch.

    2017-01-01

    Roč. 197, JUN 1 (2017), s. 277-289 ISSN 0016-2361 R&D Projects: GA ČR GC14-09692J Institutional support: RVO:67985858 Keywords : cerium oxides * dehalogenation * thermodynamic s Subject RIV: DI - Air Pollution ; Quality OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 4.601, year: 2016

  10. The BGO-OD experiment. Status

    Energy Technology Data Exchange (ETDEWEB)

    Hannappel, Juergen [Physikalisches Institut der Universitaet Bonn (Germany); Collaboration: BGO-OD-Collaboration

    2015-07-01

    In the framework of an international collaboration a new detector is set up at the accelerator facility ELSA in Bonn, the BGO-OD experiment. It aims at systematic investigation of nonstrange and strange meson photoproduction, in particular t-channel processes at low momentum transfer. The setup uniquely combines a central almost 4π acceptance BGO crystal calorimeter with a large aperture forward magnetic spectrometer providing good detection of both neutral and charged particles, complementary to other setups like CB, LEPS or CLAS. An overview of the BGO-OD detector is presented. Preliminary data from the first data takings will be shown and discussed.

  11. Microstructure and mechanical behavior of ODS and non-ODS Fe–14Cr model alloys produced by spark plasma sintering

    International Nuclear Information System (INIS)

    Auger, M.A.; Castro, V. de; Leguey, T.; Muñoz, A.; Pareja, R.

    2013-01-01

    In this work the spark plasma sintering (SPS) technique has been explored as an alternative consolidation route for producing ultra-fine grained Fe–14Cr model alloys containing a dispersion of oxide nanoparticles. Elemental powders of Fe and Cr, and nanosized Y 2 O 3 powder have been mechanically alloyed in a planetary ball mill and rapidly sintered in a spark plasma furnace. Two alloys, with nominal compositions Fe–14%Cr and Fe–14%Cr–0.3%Y 2 O 3 (wt.%), have been fabricated and their microstructure and mechanical properties investigated. The results have been compared with those obtained for other powder metallurgy processed alloys of the same composition but consolidated by hot isostatic pressing. The SPS technique under the present conditions has produced Fe–14Cr materials that apparently exhibit different microstructures yielding inferior mechanical properties than the counterpart material consolidated by hot isostatic pressing. Although the presence of a dispersion of Y-rich particles is evident, the oxide dispersion strengthened (ODS) Fe–14Cr alloy consolidated by SPS exhibits poor tensile properties. The extensive decoration of the powder particle surfaces with Cr-rich precipitates and the residual porosity appear to be responsible for the impaired properties of this ODS alloy consolidated by SPS

  12. Microstructure and mechanical behavior of ODS and non-ODS Fe–14Cr model alloys produced by spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Auger, M.A.; Castro, V. de [Departamento de Física, Universidad Carlos III de Madrid, 28911 Leganés (Spain); Leguey, T., E-mail: leguey@fis.uc3m.es [Departamento de Física, Universidad Carlos III de Madrid, 28911 Leganés (Spain); Muñoz, A.; Pareja, R. [Departamento de Física, Universidad Carlos III de Madrid, 28911 Leganés (Spain)

    2013-05-15

    In this work the spark plasma sintering (SPS) technique has been explored as an alternative consolidation route for producing ultra-fine grained Fe–14Cr model alloys containing a dispersion of oxide nanoparticles. Elemental powders of Fe and Cr, and nanosized Y{sub 2}O{sub 3} powder have been mechanically alloyed in a planetary ball mill and rapidly sintered in a spark plasma furnace. Two alloys, with nominal compositions Fe–14%Cr and Fe–14%Cr–0.3%Y{sub 2}O{sub 3} (wt.%), have been fabricated and their microstructure and mechanical properties investigated. The results have been compared with those obtained for other powder metallurgy processed alloys of the same composition but consolidated by hot isostatic pressing. The SPS technique under the present conditions has produced Fe–14Cr materials that apparently exhibit different microstructures yielding inferior mechanical properties than the counterpart material consolidated by hot isostatic pressing. Although the presence of a dispersion of Y-rich particles is evident, the oxide dispersion strengthened (ODS) Fe–14Cr alloy consolidated by SPS exhibits poor tensile properties. The extensive decoration of the powder particle surfaces with Cr-rich precipitates and the residual porosity appear to be responsible for the impaired properties of this ODS alloy consolidated by SPS.

  13. A handbook of statistical graphics using SAS ODS

    CERN Document Server

    Der, Geoff

    2014-01-01

    An Introduction to Graphics: Good Graphics, Bad Graphics, Catastrophic Graphics and Statistical GraphicsThe Challenger DisasterGraphical DisplaysA Little History and Some Early Graphical DisplaysGraphical DeceptionAn Introduction to ODS GraphicsGenerating ODS GraphsODS DestinationsStatistical Graphics ProceduresODS Graphs from Statistical ProceduresControlling ODS GraphicsControlling Labelling in GraphsODS Graphics EditorGraphs for Displaying the Characteristics of Univariate Data: Horse Racing, Mortality Rates, Forearm Lengths, Survival Times and Geyser EruptionsIntroductionPie Chart, Bar Cha

  14. A fiber optics system for monitoring utilization of ZnO adsorbent beds during desulfurization for logistic fuel cell applications

    Science.gov (United States)

    Sujan, Achintya; Yang, Hongyun; Dimick, Paul; Tatarchuk, Bruce J.

    2016-05-01

    An in-situ fiber optic based technique for direct measurement of capacity utilization of ZnO adsorbent beds by monitoring bed color changes during desulfurization for fuel cell systems is presented. Adsorbents composed of bulk metal oxides (ZnO) and supported metal oxides (ZnO/SiO2 and Cusbnd ZnO/SiO2) for H2S removal at 22 °C are examined. Adsorbent bed utilization at breakthrough is determined by the optical sensor as the maximum derivative of area under UV-vis spectrum from 250 to 800 nm observed as a function of service time. Since the response time of the sensor due to bed color change is close to bed breakthrough time, a series of probes along the bed predicts utilization of the portion of bed prior to H2S breakthrough. The efficacy of the optical sensor is evaluated as a function of inlet H2S concentration, H2S flow rate and desulfurization in presence of CO, CO2 and moisture in feed. A 6 mm optical probe is employed to measure utilization of a 3/16 inch ZnO extrudate bed for H2S removal. It is envisioned that with the application of the optical sensor, desulfurization can be carried out at high adsorbent utilization and low operational costs during on-board miniaturized fuel processing for logistic fuel cell power systems.

  15. Sulfur transformations related to revegetation of flue gas desulfurization sludge disposal sites

    Energy Technology Data Exchange (ETDEWEB)

    Barlas, S.A.; Artiola, J.F.; Salo, L.F.; Goodrich-Mahoney, J.W. [University of Arizona, Tucson, AZ (United States). Dept. of Soil, Water and Environmental Sciences

    1999-10-01

    This study investigated factors controlling redox conditions in flue gas desulfurization (FGD) sludge and identified ways to minimize the production of phytotoxic reduced sulfur species at FGD sludge disposal sites. The oxidation of reduced FGD sludge (Eh-385 mV) appears to be a two-step process mostly controlled by water content. Eighty percent of total sulfide in reduced sludge was oxidized within 20 h of exposure to air with constant water evaporation. When organic carbon (OC) was added to saturated oxidized sludge, the Eh dropped exponentially. Sulfate reduction began at an Eh of about -75 mV and reached a maximum at -265 to -320 mV. Water content, degree of mixing, concentration of OC, and temperature control the rate and extent of reduction of FGD sludge. This suggests that water saturation and OC inputs to revegetated disposal sites should be controlled, especially during warm temperatures, to prevent production of phytotoxic levels of sulfides.

  16. Hot coal gas desulfurization with manganese-based sorbents. Final report, September 1992--December 1994

    Energy Technology Data Exchange (ETDEWEB)

    Hepworth, M.T.; Slimane, R.B.

    1994-11-01

    The focus of much current work being performed by the Morgantown Energy Technology Center (METC) of the Department of Energy on hot coal-derived fuel gas desulfurization is in the use of zinc-based sorbents. METC has shown interest in formulating and testing manganese-based pellets as alternative effective sulfur sorbents in the 700 to 1200{degree}C temperature range. To substantiate the potential superiority of Mn-based pellets, a systematic approach toward the evaluation of the desulfurizing power of single-metal sorbents is developed based on thermodynamic considerations. This novel procedure considered several metal-based sorbents and singled out manganese oxide as a prime candidate sorbent capable of being utilized under a wide temperature range, irrespective of the reducing power (determined by CO{sub 2}/CO ratio) of the fuel gas. Then, the thermodynamic feasibility of using Mn-based pellets for the removal of H{sub 2}S from hot-coal derived fuel gases, and the subsequent oxidative regeneration of loaded (sulfided) pellets was established. It was concluded that MnO is the stable form of manganese for virtually all commercially available coal-derived fuel gases. In addition, the objective of reducing the H{sub 2}S concentration below 150 ppMv to satisfy the integrated gasification combined cycle system requirement was shown to be thermodynamically feasible. A novel process is developed for the manufacture of Mn-based spherical pellets which have the desired physical and chemical characteristics required.

  17. Desulfurization of 2-thiouracil nucleosides: conformational studies of 4-pyrimidinone nucleosides.

    Science.gov (United States)

    Kraszewska, Karina; Kaczyńska, Iwona; Jankowski, Stefan; Karolak-Wojciechowska, Janina; Sochacka, Elzbieta

    2011-04-01

    4-Pyrimidinone ribofuranoside (H(2)o(4)U) and 4-pyrimidinone 2'-deoxyribofuranoside (dH(2)o(4)U) were synthesized by the oxidative desulfurization of parent 2-thiouracil nucleosides with m-chloroperbenzoic acid. The crystal structures of H(2)o(4)U and dH(2)o(4)U and their conformations in solution were determined and compared with corresponding 2-thiouracil and uracil nucleosides. The absence of a large 2-thiocarbonyl/2-carbonyl group in the nucleobase moiety results in C2'-endo puckering of the ribofuranose ring (S conformer) in the crystal structure of H(2)o(4)U, which is not typical of RNA nucleosides. Interestingly, the hydrogen bonding network in the crystals of dH(2)o(4)U stabilizes the sugar moiety conformation in the C3'-endo form (N conformer), rarely found in DNA nucleosides. In aqueous solution, dH(2)o(4)U reveals a similar population of the C2'-endo conformation (65%) to that of 2'-deoxy-2-thiouridine (62%), while the 62% population of the S conformer for H(2)o(4)U is significantly different from that of the parent 2-thiouridine, for which the N conformer is dominant (71%). Such a difference may be of biological importance, as the desulfurization process of natural tRNA 2-thiouridines may occur under conditions of oxidative stress in the cell and may influence the decoding process. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. High-Temperature Desulfurization of Heavy Fuel-Derived Reformate Gas Streams for SOFC Applications

    Science.gov (United States)

    Flytzani-Stephanopoulos, Maria; Surgenor, Angela D.

    2007-01-01

    Desulfurization of the hot reformate gas produced by catalytic partial oxidation or autothermal reforming of heavy fuels, such as JP-8 and jet fuels, is required prior to using the gas in a solid oxide fuel cell (SOFC). Development of suitable sorbent materials involves the identification of sorbents with favorable sulfidation equilibria, good kinetics, and high structural stability and regenerability at the SOFC operating temperatures (650 to 800 C). Over the last two decades, a major barrier to the development of regenerable desulfurization sorbents has been the gradual loss of sorbent performance in cyclic sulfidation and regeneration at such high temperatures. Mixed oxide compositions based on ceria were examined in this work as regenerable sorbents in simulated reformate gas mixtures and temperatures greater than 650 C. Regeneration was carried out with dilute oxygen streams. We have shown that under oxidative regeneration conditions, high regeneration space velocities (greater than 80,000 h(sup -1)) can be used to suppress sulfate formation and shorten the total time required for sorbent regeneration. A major finding of this work is that the surface of ceria and lanthanan sorbents can be sulfided and regenerated completely, independent of the underlying bulk sorbent. This is due to reversible adsorption of H2S on the surface of these sorbents even at temperatures as high as 800 C. La-rich cerium oxide formulations are excellent for application to regenerative H2S removal from reformate gas streams at 650 to 800 C. These results create new opportunities for compact sorber/regenerator reactor designs to meet the requirements of solid oxide fuel cell systems at any scale.

  19. Microstructure and Mechanical Property of ODS Ferritic Steels Using Commercial Alloy Powders for High Temperature Service Applications

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Sanghoon; Choi, Byoung-Kwon; Kang, Suk Hoon; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Oxide dispersion strengthening (ODS) is one of the promising ways to improve the mechanical property at high temperatures. This is mainly attributed to uniformly distributed nano-oxide particle with a high density, which is extremely stable at the high temperature and acts as effective obstacles when the dislocations are moving. In this study, as a preliminary examination to develop the advanced structural materials for high temperature service applications, ODS ferritic steels were fabricated using commercial alloy powders and their microstructural and mechanical properties were investigated. In this study, ODS ferritic steels were fabricated using commercial stainless steel 430L powder and their microstructures and mechanical properties were investigated. Morphology of micro-grains and oxide particles were significantly changed by the addition of minor alloying elements such as Ti, Zr, and Hf. The ODS ferritic steel with Zr and Hf additions showed ultra-fine grains with fine complex oxide particles. The oxide particles were uniformly located in grains and on the grain boundaries. This led to higher hardness than ODS ferritic steel with Ti addition.

  20. Microstructural Evolution of Advanced Radiation-Resistant ODS Steel with Different Lengths of Mechanical Alloying Time

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Sanghoon; Kim, Ga Eon; Kang, Suk Hoon; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Austenitic stainless steel may be one of the candidates because of good strength and corrosion resistance at the high temperatures, however irradiation swelling well occurred to 120dpa at high temperatures and this leads the decrease of the mechanical properties and dimensional stability. Compared to this, ferritic/ martensitic steel is a good solution because of excellent thermal conductivity and good swelling resistance. Unfortunately, the available temperature range of ferritic/martensitic steel is limited up to 650 .deg. C. ODS steel is the most promising structural material because of excellent creep and irradiation resistance by uniformly distributed nano-oxide particles with a high density which is extremely stable at the high temperature in ferritic/martensitic matrix. In this study, powder properties and microstructures of the ODS steel with different length of mechanical alloying time was investigated. The ODS steel milled 5h showed homogeneous grain structure with the highest hardness.

  1. Microstructural Evolution of Advanced Radiation-Resistant ODS Steel with Different Lengths of Mechanical Alloying Time

    International Nuclear Information System (INIS)

    Noh, Sanghoon; Kim, Ga Eon; Kang, Suk Hoon; Kim, Tae Kyu

    2015-01-01

    Austenitic stainless steel may be one of the candidates because of good strength and corrosion resistance at the high temperatures, however irradiation swelling well occurred to 120dpa at high temperatures and this leads the decrease of the mechanical properties and dimensional stability. Compared to this, ferritic/ martensitic steel is a good solution because of excellent thermal conductivity and good swelling resistance. Unfortunately, the available temperature range of ferritic/martensitic steel is limited up to 650 .deg. C. ODS steel is the most promising structural material because of excellent creep and irradiation resistance by uniformly distributed nano-oxide particles with a high density which is extremely stable at the high temperature in ferritic/martensitic matrix. In this study, powder properties and microstructures of the ODS steel with different length of mechanical alloying time was investigated. The ODS steel milled 5h showed homogeneous grain structure with the highest hardness

  2. Effect of Mechanical Alloying Atmospheres and Oxygen Concentration on Mechanical Properties of ODS Ferritic Steels

    International Nuclear Information System (INIS)

    Noh, Sanghoon; Choi, Byoungkwon; Han, Changhee; Kim, Kibaik; Kang, Sukhoon; Chun, Youngbum; Kim, Taekyu

    2013-01-01

    Finely dispersed nano-oxide particles with a high number density in the homogeneous grain matrix are essential to achieve superior mechanical properties at high temperatures, and these unique microstructures can be obtained through the mechanical alloying (MA) and hot consolidation process. The microstructure and mechanical property of ODS steel significantly depends on its powder property and the purity after the MA process. These contents should be carefully controlled to improve the mechanical property at elevated temperature. In particular, appropriate the control of oxygen concentration improves the mechanical property of ODS steel at high temperature. An effective method is to control the mechanical alloying atmosphere by high purity inert gas. In the present study, the effects of mechanical alloying atmospheres and oxygen concentration on the mechanical property of ODS steel were investigated. ODS ferritic alloys were fabricated in various atmospheres, and the HIP process was used to investigate the effects of MA atmospheres and oxygen concentration on the microstructure and mechanical property. ODS ferritic alloys milled in an Ar-H 2 mixture, and He is effective to reduce the excess oxygen concentration. The YH 2 addition made an extremely reduced oxygen concentration by the internal oxygen reduction reaction and resulted in a homogeneous microstructure and superior creep strength

  3. Reduction in Defect Content of ODS Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ritherdon, J

    2001-05-15

    The work detailed within this report is a continuation of earlier work carried out under contract number 1DX-SY382V. The earlier work comprises a literature review of the sources and types of defects found principally in Fe-based ODS alloys as well as experimental work designed to identify defects in the prototype ODS-Fe{sub 3}Al alloy, deduce their origins and to recommend methods of defect reduction. The present work is an extension of the experimental work already reported and concentrates on means of reduction of defects already identified rather than the search for new defect types. This report also includes results gathered during powder separation trials, conducted by the University of Groningen, Netherlands and coordinated by the University of Liverpool, involving the separation of different metallic powders in terms of their differing densities. The scope and objectives of the present work were laid out in the technical proposal ''Reduction in Defect Content in ODS Alloys-III''. All the work proposed in the ''Statement of Work'' section of the technical proposal has been carried out and all work extra to the ''Statement of Work'' falls within the context of an ODS-Fe{sub 3}Al alloy of improved overall quality and potential creep performance in the consolidated form. The outturn of the experimental work performed is reported in the following sections.

  4. OD structures in crystallography - basic concepts

    Czech Academy of Sciences Publication Activity Database

    Ďurovič, S.; Hybler, Jiří

    2006-01-01

    Roč. 221, - (2006), s. 63-76 ISSN 0044-2968 R&D Projects: GA ČR GA205/03/0439 Institutional research plan: CEZ:AV0Z10100521 Keywords : OD structures * polytypism * cronstedtite * kermesite * Fourier synthesis Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.897, year: 2006

  5. Self-ion Irradiation Damage of F/M and ODS steels

    International Nuclear Information System (INIS)

    Kang, Suk Hoon; Chun, Young-Bum; Noh, Sanghoon; Jang, Jinsung; Kim, Tae Kyu

    2014-01-01

    Oxide dispersion strengthened (ODS) ferritic steels are potential high-temperature materials that are stabilized by dispersed particles at elevated temperatures. These dispersed particles improve the tensile strength and creep rupture strength, they are expected to increase the operation temperature up to approximately 650 .deg. C and also enhance the energy efficiency of the fusion reactor. Some reports described that the nano-clusters are strongly resistant to coarsening by annealing up to 1000 .deg. C, and nanoclusters do not change after ion irradiation up to 0.7 dpa at 300 .deg. C. ODS steels will be inevitably exposed to neutron irradiation condition; the irradiation damages, creep and swelling are always great concern. The dispersed oxide particles are believed to determine the performance of the steel, even the radiation resistance. In this study, F/M and ODS model alloys of Korea Atomic Energy Research Institute (KAERI) were irradiated by Fe 3+ self-ion to emulate the neutron irradiation effect. In this study, Fe 3+ self-ion irradiation is used as means of introducing radiation damage in F/M steel and ODS steel. The ion accelerator named DuET (in Kyoto University, Japan) was used for irradiation of Fe 3+ ion by 6.4 MeV at 300 .deg. C. The maximum damage rate in F/M and ODS steels were estimated roughly 6 dpa. After radiation, point or line defects were dominantly observed in F/M steel, on the other hands, small circular cavities were typically observed in ODS steel. Nanoindentation is a useful tool to determine the irradiationinduced hardness change in the damage layer of ionirradiated iron base alloys

  6. Metabolic cooperation of ascorbic acid and glutathione in normal and vitamin C-deficient ODS rats.

    Science.gov (United States)

    Wang, Y; Kashiba, M; Kasahara, E; Tsuchiya, M; Sato, E F; Utsumi, K; Inoue, M

    2001-01-01

    Although the coordination of various antioxidants is important for the protection of organisms from oxidative stress, dynamic aspects of the interaction of endogenous antioxidants in vivo remain to be elucidated. We studied the metabolic coordination of two naturally occurring water-soluble antioxidants, ascorbic acid (AA) and reduced glutathione (GSH), in liver, kidney and plasma of control and scurvy-prone osteogenic disorder Shionogi (ODS) rats that hereditarily lack the ability to synthesize AA. When supplemented with AA, its levels in liver and kidney of ODS rats increased to similar levels of those in control rats. Hepato-renal levels of glutathione were similar with the two animal groups except for the slight increase in its hepatic levels in AA-supplemented ODS rats. Administration of L-buthionine sulfoximine (BSO), a specific inhibitor of GSH synthesis, rapidly decreased the hepato-renal levels of glutathione in a biphasic manner, a rapid phase followed by a slower phase. Kinetic analysis revealed that glutathione turnover was enhanced significantly in liver mitochondria and renal cytosol of ODS rats. Administration of BSO significantly increased AA levels in the liver and kidney of control rats but decreased them in AA-supplemented ODS rats. Kinetic analysis revealed that AA is synthesized by control rat liver by some BSO-enhanced mechanism and the de novo synthesized AA is transferred to the kidney. Such a coordination of the metabolism of GSH and AA in liver and kidney is suppressed in AA-deficient ODS rats. These and other results suggest that the metabolism of AA and GSH forms a compensatory network by which oxidative stress can be decreased.

  7. Highly stable and regenerable Mn-based/SBA-15 sorbents for desulfurization of hot coal gas

    International Nuclear Information System (INIS)

    Zhang, F.M.; Liu, B.S.; Zhang, Y.; Guo, Y.H.; Wan, Z.Y.; Subhan, Fazle

    2012-01-01

    Highlights: ► A series of mesoporous Cu x Mn y O z /SBA-15 sorbents were fabricated for hot coal gas desulfurization. ► 1Cu9Mn/SBA-15 sorbent with high breakthrough sulfur capacity is high stable and regenerable. ► Utilization of SBA-15 constrained the sintering and pulverization of sorbents. - Abstract: A series of mesoporous xCuyMn/SBA-15 sorbents with different Cu/Mn atomic ratios were prepared by wet impregnation method and their desulfurization performance in hot coal gas was investigated in a fixed-bed quartz reactor in the range of 700–850 °C. The successive nine desulfurization–regeneration cycles at 800 °C revealed that 1Cu9Mn/SBA-15 presented high performance with durable regeneration ability due to the high dispersion of Mn 2 O 3 particles incorporated with a certain amount of copper oxides. The breakthrough sulfur capacity of 1Cu9Mn/SBA-15 observed 800 °C is 13.8 g S/100 g sorbents, which is remarkably higher than these of 40 wt%LaFeO 3 /SBA-15 (4.8 g S/100 g sorbents) and 50 wt%LaFe 2 O x /MCM-41 (5.58 g S/100 g sorbents) used only at 500–550 °C. This suggested that the loading of Mn 2 O 3 active species with high thermal stability to SBA-15 support significantly increased sulfur capacity at relatively higher sulfidation temperature. The fresh and used xCuyMn/SBA-15 sorbents were characterized by means of BET, XRD, XPS, XAES, TG/DSC and HRTEM techniques, confirmed that the structure of the sorbents remained intact before and after hot coal gas desulfurization.

  8. Desulfurization performance of azole-based ionic liquids

    Directory of Open Access Journals (Sweden)

    Liubei CHENG

    2017-10-01

    Full Text Available In order to study the addition of functional groups in ionic liquid anion and cation to achieve better absorbing of SO2, the 1,1,3,3-tetramethylguanidine triazole ( is synthesized using 1,1,3,3-tetramethylguanidine and triazole as raw materials. The desulfurization performance of the synthesized is systematically studied. The desulfurization performance and desulfurization mechanism of the are discussed. The results show that the has good performance of desulfurization and regeneration. At the atmospheric pressure, 1 mol of the absorbs 2.964 mol of SO2 at 20 ℃. With the increase of temperature, the desulfurization capacity of the decreases gradually. The molar absorption ratio increases with the increase of SO2 partial pressure, and under the conditions of 130 ℃, the desorption rate of the ionic liquid after saturated adsorption reaches over 95%. The mechanism investigation results show that the interaction of SO2 and is the combination of chemical absorption and physical absorption. The results have a certain reference value to improve the efficiency of flue gas treatment.

  9. Void formation in ODS EUROFER produced by hot isostatic pressing

    Energy Technology Data Exchange (ETDEWEB)

    Ortega, Y.; Monge, M.A.; Munoz, A.; Leguey, T.; Pareja, R. [Madrid Univ. Carlos-3, Dept. de Fisica (Spain); Castro, V. de [Oxford Univ., Dept. of Materials (United Kingdom)

    2007-07-01

    Full text of publication follows: An obstacle in the development of oxide dispersion strengthened (ODS) steels for structural applications in fusion reactors is the toughness lack of the material produced by powder metallurgy and consolidated by hot isostatic pressing (HIP). In particular, ODS EUROFER steel with Y{sub 2}O{sub 3} particles appears to exhibit poor impact properties. To asses the capabilities of this material, it is necessary elucidate if its failure is an inherent characteristic of the production process that can not be mitigated by normalizing and tempering treatments. In order to investigate this particular point, the evolution of the structural defects retained in the ODS material during isochronal annealing has been probed by positron annihilation spectroscopy. The present study has been performed on bail milled EUROFER powders consolidated by HIP, containing 0.25 wt % Y{sub 2}O{sub 3} and without Y{sub 2}O{sub 3}. For comparison, un-milled EUROFER powder consolidated under identical conditions, and as-received EUROFER97 plate produced by Boehler AG have been also investigated. Samples from these four materials were isochronally annealed for 90 min up to 1323 K. Materials produced from milled powders had a longer positron lifetime than the one produced from un-milled powder or the EUROFER plate. In the material containing Y{sub 2}O{sub 3}, i.e. in ODS EUROFER, annealing above 723 K produced a continuous increase in the mean positron lifetime <{tau}> up to reach a maximum value of 208 ps after annealing at 1223 K. A similar annealing behavior was observed for Y{sub 2}O{sub 3}-free milled EUROFER (milled EUROFER), but the <{tau}> value steeply changed from {approx}160 ps at 823 K to {approx}200 ps after annealing at 1023 K. Subsequent anneals above this temperature produced meaningless changes in <{tau}>. The <{tau}> increase in milled EUROFER was accompanied by the intensity increase of a lifetime component of {approx}360 ps that is characteristic

  10. Influence of hot rolling and high speed hydrostatic extrusion on the microstructure and mechanical properties of RAF ODS steel

    International Nuclear Information System (INIS)

    Oksiuta, Z.; Kurzydlowski, K.J.; Baluc, N.

    2009-01-01

    Argon gas atomized, pre-alloyed Fe-14Cr-2W-0.3Ti oxide dispersion strengthened (ODS) ferritic steel powder was mechanically alloyed with 0.3Y2O3 (wt.%) nano-particles in attritor ball mill and consolidated by hot isostatic pressing (HIP) at 1150 deg. C under pressure of 200 MPa for 3 hrs. To improve mechanical properties of as HIPped ODS ingots the material was undergone further thermo-mechanical treatment (TMT), namely: hot rolling (HR) at 850 deg. C or high speed hot extrusion (HSHE) at 850 deg. C. After TMT both materials were annealed at 1050 deg. C for 1 h in vacuum. Transmission electron microscopy (TEM) observations of the ODS alloys after TMT and heat treatment exhibited elongated in a longitudinal direction grains with an average size of 75 μm. However, an equiaxed, smaller than 500 nm grains were also found in the microstructure of both materials. Different size and morphology of oxides particles were also observed. Bigger, about 150 nm Ti-Al-O particles were usually located at grain boundaries whereas Y-Ti-O nanoclusters of about 5 nm were uniformly distributed in ODS steel matrix. The Charpy impact tests revealed significantly better about 90% (5.8 J) upper shelf energy (USE) of material after HSHE but ductile to brittle transition temperature (DBTT) of both alloys was unsatisfactory. As-HR ODS steel has shown DBTT of about 55 deg. C whereas HSHE ODS steel has about 75 deg. C. This relatively high values of transition temperature were probably caused by oxides particles present at grain boundaries of the ODS alloys which decreased fracture properties of the ODS steels. High temperature tensile properties of both ODS alloys are found to be satisfactory in full range of the testing temperature from 23 up to 750 deg. C. However, about 15% better UTS and YS0.2 (1350 MPa and 1285 MPa, respectively) as well as ductility were measured in the case of the as-HSHE ODS steel. These results indicates that HSHE process of the ODS steel can be considered as more

  11. ODS steel fabrication: relationships between process, microstructure and mechanical properties

    International Nuclear Information System (INIS)

    Couvrat, M.

    2011-01-01

    Oxide Dispersion Strengthened (ODS) steels are promising candidate materials for generation IV and fusion nuclear energy systems thanks to their excellent thermal stability, high-temperature creep strength and good irradiation resistance. Their superior properties are attributed both to their nano-structured matrix and to a high density of Y-Ti-O nano-scale clusters (NCs). ODS steels are generally prepared by Mechanical Alloying of a pre-alloyed Fe-Cr-W-Ti powder with Y 2 O 3 powder. A fully dense bar or tube is then produced from this nano-structured powder by the mean of hot extrusion. The aim of this work was to determine the main parameters of the process of hot extrusion and to understand the link between the fabrication process, the microstructure and the mechanical properties. The material microstructure was characterized at each step of the process and bars were extruded with varying hot extrusion parameters so as to identify the impact of these parameters. Temperature then appeared to be the main parameter having a great impact on microstructure and mechanical properties of the extruded material. We then proposed a cartography giving the microstructure versus the process parameters. Based on these results, it is possible to control very accurately the obtained material microstructure and mechanical properties setting the extrusion parameters. (author) [fr

  12. Design and simulation of a 1.2 MeV electron accelerator used for desulfuration and denitrogenation

    International Nuclear Information System (INIS)

    Zhou Jun; Zhu Dajun; Liu Shenggang

    2005-01-01

    This paper presents the structural design and functional analysis of a new kind of 1.2 MeV industrial electron accelerator. PIC (Particle-In-Cell) method is used to simulate this accelerator and to optimize the design, the results show that the optics property of this accelerator has been improved. This electron accelerator is used for desulfuration and denitrogenation in environmental industry. This application purifies flue gases of the thermal power station from Sulphurous oxide and Nitrogen oxide in order to reduce the pollution in the air. (author)

  13. The effect of organisational context on organisational development (OD) interventions

    OpenAIRE

    Sanjana Brijball Parumasur

    2012-01-01

    Orientation: Systematic and congruent organisational structures, systems, strategies and designs are necessary for the successful implementation of organisational development (OD) interventions. Research purpose: This article examines national and international OD practices. It assesses the effect of diverse cultures and cultural values for determining the effectiveness of OD interventions. Motivation for the study: Most organisational change and development programmes fail and only a ...

  14. 46 CFR 280.4 - Standards governing payment of ODS.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Standards governing payment of ODS. 280.4 Section 280.4... Standards governing payment of ODS. (a) Full payment. Except to the extent otherwise provided in § 280.8, ODS shall be paid in full to the operator for vessel operations on the inbound and outbound legs of...

  15. Development of Austenitic ODS Strengthened Alloys for Very High Temperature Applications

    Energy Technology Data Exchange (ETDEWEB)

    Stubbins, James [Univ. of Illinois, Urbana-Champaign, IL (United States); Heuser, Brent [Univ. of Illinois, Urbana-Champaign, IL (United States); Robertson, Ian [Kyushu Univ. (Japan); Sehitoglu, Huseyin [Univ. of Illinois, Urbana-Champaign, IL (United States); Sofronis, Petros [Kyushu Univ. (Japan); Gewirth, Andrew [Kyushu Univ. (Japan)

    2015-04-22

    This “Blue Sky” project was directed at exploring the opportunities that would be gained by developing Oxide Dispersion Strengthened (ODS) alloys based on the Fe-Cr-Ni austenitic alloy system. A great deal of research effort has been directed toward ferritic and ferritic/martensitic ODS alloys which has resulted in reasonable advances in alloy properties. Similar gains should be possible with austenitic alloy which would also take advantage of other superior properties of that alloy system. The research effort was aimed at the developing an in-depth understanding of the microstructural-level strengthening effects of ODS particles in austentic alloys. This was accomplished on a variety of alloy compositions with the main focus on 304SS and 316SS compositions. A further goal was to develop an understanding other the role of ODS particles on crack propagation and creep performance. Since these later two properties require bulk alloy material which was not available, this work was carried out on promising austentic alloy systems which could later be enhanced with ODS strengthening. The research relied on a large variety of micro-analytical techniques, many of which were available through various scientific user facilities. Access to these facilities throughout the course of this work was instrumental in gathering complimentary data from various analysis techniques to form a well-rounded picture of the processes which control austenitic ODS alloy performance. Micromechanical testing of the austenitic ODS alloys confirmed their highly superior mechanical properties at elevated temperature from the enhanced strengthening effects. The study analyzed the microstructural mechanisms that provide this enhanced high temperature performance. The findings confirm that the smallest size ODS particles provide the most potent strengthening component. Larger particles and other thermally- driven precipitate structures were less effective contributors and, in some cases, limited

  16. Characterisation of As-deformed microstructure of ODS NI-Base superalloy and ODS ferritic steel prior to directional recrystallisation

    International Nuclear Information System (INIS)

    Baloch, M.M.; Memon, S.A.

    2007-01-01

    The materials studied are unusual in the sense that they have been prepared from mechanically alloyed procedures, including compaction and hot extrusion. It was felt necessary to characterise the initial microstructure thoroughly prior to directional recrystallisation of the alloys. Following consolidation by hot extrusion, dispersion strengthened superalloys appear to display a very fine sub-micron grain size consisting of both dislocation free recrystallised material and un- recrystallised regions of high dislocation density. It is found that there is a very fine dislocation cell structure in the ODS (Oxide Dispersion Strengthened) Ferritic stainless Steel prior to recrystallisation treatment, which shows that alloy is in old-deformed condition after mechanical alloying, extrusion I hot-working. This is in contrast to the mechanically alloyed Nickel Base Superalloy, which have consistently been found to be in primary recrystallisation state following extrusion. In order to understand the recrystallisation behaviour of the two mechanically illoyed materials with commercial designations MA6000 and MA956, a measurement of the orientation relationship between adjacent grains in the as- deformed ODS alloys has also been carried out using Transmission Electron microscope. (author)

  17. High Cr ODS steels R and D for high burnup fuel cladding

    International Nuclear Information System (INIS)

    Kimura, A.; Kasada, R.; Kishimoto, H.; Iwata, N.; Cho, H.-S.; Toda, N.; Yutani, K.; Ukai, S.; Fujiwara, M.

    2007-01-01

    High-performance cladding materials is essential to realize highly efficient and high-burnup operation over 150 GWd/t of so called Generation IV nuclear energy systems, such as supercritical-water-cooled reactor (SCWR) and lead-cooled fast reactor (LFR). Oxide dispersion strengthening (ODS) ferritic/ martensitic steels, which contain 9-12%Cr, show rather high resistance to neutron irradiation embrittlement and high strength at elevated temperatures. However, their corrosion resistance is not good enough in SCW and in lead at high temperatures. High-Cr ODS steels have been developed to improve corrosion resistance. An increase in Cr content an addition resulted in a drastic improvement of corrosion resistance in SCW and in lead. On the contrary, high-Cr steels often show an enhancement of aging embrittlement as well as irradiation embrittlement. Anisotropy in tensile properties is another issue. In order to overwhelm these issues, surveillance tests of the material performance have been performed for high Cr-ODS steels produced by new processing technologies. It is demonstrated that the dispersion of nono-sized oxide particles in high density is effective to attain high-performance and high-Cr ODS steels have a high potential as fuel cladding materials for SCWR and LFR with high efficiency and high burnup. (authors)

  18. Hardening of ODS ferritic steels under irradiation with high-energy heavy ions

    Science.gov (United States)

    Ding, Z. N.; Zhang, C. H.; Yang, Y. T.; Song, Y.; Kimura, A.; Jang, J.

    2017-09-01

    Influence of the nanoscale oxide particles on mechanical properties and irradiation resistance of oxide-dispersion-strengthened (ODS) ferritic steels is of critical importance for the use of the material in fuel cladding or blanket components in advanced nuclear reactors. In the present work, impact of structures of oxide dispersoids on the irradiation hardening of ODS ferritic steels was studied. Specimens of three high-Cr ODS ferritic steels containing oxide dispersoids with different number density and average size were irradiated with high-energy Ni ions at about -50 °C. The energy of the incident Ni ions was varied from 12.73 MeV to 357.86 MeV by using an energy degrader at the terminal so that a plateau of atomic displacement damage (∼0.8 dpa) was produced from the near surface to a depth of 24 μm in the specimens. A nanoindentor (in constant stiffness mode with a diamond Berkovich indenter) and a Vickers micro-hardness tester were used to measure the hardeness of the specimens. The Nix-Gao model taking account of the indentation size effect (ISE) was used to fit the hardness data. It is observed that the soft substrate effect (SSE) can be diminished substantially in the irradiated specimens due to the thick damaged regions produced by the Ni ions. A linear correlation between the nano-hardeness and the micro-hardness was found. It is observed that a higher number density of oxide dispersoids with a smaller average diameter corresponds to an increased resistance to irradiation hardening, which can be ascribed to the increased sink strength of oxides/matrix interfaces to point defects. The rate equation approach and the conventional hardening model were used to analyze the influence of defect clusters on irradiation hardening in ODS ferritic steels. The numerical estimates show that the hardening caused by the interstitial type dislocation loops follows a similar trend with the experiment data.

  19. Microstructure of HIPed and SPSed 9Cr-ODS steel and its effect on helium bubble formation

    International Nuclear Information System (INIS)

    Lu, Chenyang; Lu, Zheng; Xie, Rui; Liu, Chunming; Wang, Lumin

    2016-01-01

    Two 9Cr-ODS steels with the same nominal composition were consolidated by hot isostatic pressing (HIP, named COS-1) and spark plasma sintering (SPS, named COS-2). Helium ions were implanted into COS-1, COS-2 and non-ODS Eurofer 97 steels up at 673 K. Microstructures before and after helium ion implantations were carefully characterized. The results show a bimodal grain size distribution in COS-2 and a more uniform grain size distribution in COS-1. Nanoscale clusters of GP-zone type Y–Ti–O and Y_2Ti_2O_7 pyrochlore as well as large spinel Mn(Ti)Cr_2O_4 particles are all observed in the two ODS steels. The Y–Ti-enriched nano-oxides in COS-1 exhibit higher number density and smaller size than in COS-2. The Y–Ti-enriched nano-oxides in fine grains of COS-2 show higher number density and smaller size than that in coarse grains of COS-2. Nano-oxides effectively trap helium atoms and lead to the formation of high density and ultra-fine helium bubbles. - Highlights: • The microstructure changes of two ODS steels before and after helium ion implantation have been elucidated. • The mechanism of the microstructures of ODS steels under varied thermal mechanical processing paths have been explored. • The dependence of the size, density and distribution of helium bubbles on the specific microstructure features are explored.

  20. Dissimilar Joining of ODS and F/M Steel Tube by Friction Stir Welding

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Suk Hoon; Noh, Sanghoon; Kim, Jun Hwan; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    Oxide Dispersion strengthened (ODS) steels, it is well known that uniform nano-oxide dispersoids act as pinning points to obstruct dislocation and grain boundary motion, however, those advantages will be disappeared while the material is subjected to the high temperature of conventional fusion welding. Rotary friction welding, also referred to as friction stir welding (FSW), has shown great promise as a method for welding traditionally difficult to weld materials such as aluminum alloys. This relatively new technology has more recently been applied to higher melting temperature alloys such as steels, nickel-based and titanium alloys. Friction stir processing (FSP) is a method of changing the properties of a metal through intense, localized plastic deformation. FSW is the precursor of the FSP technique. When ideally implemented, this process mixes the material without changing the phase and creates a microstructure with fine, equiaxed grains. This homogeneous grain structure, separated by high-angle boundaries, allows some alloys to take on superplastic properties. In this study, FSW is used as a substitutive welding process between FMS tube and ODS parts. The dimension of tube is 7.0 OD, 0.5 T. During the FSW, dynamic-recrystallized grains are developed; the uniform oxides Dispersion is preserved in the metal matrix. The microstructure and microtexture of the material near the stir zone is found to be influenced by the rotational behavior of the tool. The additive effect from FSP on sample surface is considered. Since the mechanical alloying (MA) and FSP commonly apply extreme shear deformation on materials, the Dispersion of oxide particle in ODS steels is very active during both processes. Friction stir welding appears to be a very promising technique for the welding of FMS and ODS steels in the form of sheet and tube. FSW could successfully produce defect-free welds on FMS tubes and ODS ring assembly. FSW produces a fine grain structure consisting of ferrite and

  1. Dissimilar Joining of ODS and F/M Steel Tube by Friction Stir Welding

    International Nuclear Information System (INIS)

    Kang, Suk Hoon; Noh, Sanghoon; Kim, Jun Hwan; Kim, Tae Kyu

    2014-01-01

    Oxide Dispersion strengthened (ODS) steels, it is well known that uniform nano-oxide dispersoids act as pinning points to obstruct dislocation and grain boundary motion, however, those advantages will be disappeared while the material is subjected to the high temperature of conventional fusion welding. Rotary friction welding, also referred to as friction stir welding (FSW), has shown great promise as a method for welding traditionally difficult to weld materials such as aluminum alloys. This relatively new technology has more recently been applied to higher melting temperature alloys such as steels, nickel-based and titanium alloys. Friction stir processing (FSP) is a method of changing the properties of a metal through intense, localized plastic deformation. FSW is the precursor of the FSP technique. When ideally implemented, this process mixes the material without changing the phase and creates a microstructure with fine, equiaxed grains. This homogeneous grain structure, separated by high-angle boundaries, allows some alloys to take on superplastic properties. In this study, FSW is used as a substitutive welding process between FMS tube and ODS parts. The dimension of tube is 7.0 OD, 0.5 T. During the FSW, dynamic-recrystallized grains are developed; the uniform oxides Dispersion is preserved in the metal matrix. The microstructure and microtexture of the material near the stir zone is found to be influenced by the rotational behavior of the tool. The additive effect from FSP on sample surface is considered. Since the mechanical alloying (MA) and FSP commonly apply extreme shear deformation on materials, the Dispersion of oxide particle in ODS steels is very active during both processes. Friction stir welding appears to be a very promising technique for the welding of FMS and ODS steels in the form of sheet and tube. FSW could successfully produce defect-free welds on FMS tubes and ODS ring assembly. FSW produces a fine grain structure consisting of ferrite and

  2. MARKETING OF BYPRODUCT GYPSUM FROM FLUE GAS DESULFURIZATION

    Science.gov (United States)

    The report gives results of an evaluation of the 1985 marketing potential of byproduct gypsum from utility flue gas desulfurization (FGD), for the area east of the Rocky Mountains, using the calculated gypsum production rates of 14 selected power plants. The 114 cement plants and...

  3. Workshop on sulfur chemistry in flue gas desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, W.E. Jr.

    1980-05-01

    The Flue Gas Desulfurization Workshop was held at Morgantown, West Virginia, June 7-8, 1979. The presentations dealt with the chemistry of sulfur and calcium compounds in scrubbers. DOE and EPRI programs in this area are described. Ten papers have been entered individually into EDB and ERA. (LTN)

  4. Comments on "Ceria-Zirconia High-Temperature Desulfurization Sorbents".

    Czech Academy of Sciences Publication Activity Database

    Hartman, Miloslav; Trnka, Otakar

    2006-01-01

    Roč. 45, č. 4 (2006), s. 1548-1549 ISSN 0888-5885 Institutional research plan: CEZ:AV0Z40720504 Keywords : hydrogen sulfide * desulfurization * cerium sorbent Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.518, year: 2006

  5. Mechanical, Hygric and Thermal Properties of Flue Gas Desulfurization Gypsum

    Directory of Open Access Journals (Sweden)

    P. Tesárek

    2004-01-01

    Full Text Available The reference measurements of basic mechanical, thermal and hygric parameters of hardened flue gas desulfurization gypsum are carried out. Moisture diffusivity, water vapor diffusion coefficient, thermal conductivity, volumetric heat capacity and linear thermal expansion coefficient are determined with the primary aim of comparison with data obtained for various types of modified gypsum in the future. 

  6. Desulfurization of waste gases of the incinerator after petroleum refining

    International Nuclear Information System (INIS)

    Samesova, D.; Ladomersky, J.

    2001-01-01

    Desulfurization of waste gases of the incinerator after petroleum refining was developed. Mixing of wastes with lime (10% of additive of total volume of waste) was proved before introduction into incinerator. Concentrations of CO, CO 2 , O 2 , NO 2 , SO 2 and temperature of combustion products were measured by automatic analyser

  7. Core-in-shell sorbent for hot coal gas desulfurization

    Science.gov (United States)

    Wheelock, Thomas D.; Akiti, Jr., Tetteh T.

    2004-02-10

    A core-in-shell sorbent is described herein. The core is reactive to the compounds of interest, and is preferably calcium-based, such as limestone for hot gas desulfurization. The shell is a porous protective layer, preferably inert, which allows the reactive core to remove the desired compounds while maintaining the desired physical characteristics to withstand the conditions of use.

  8. Effect of two-stage sintering process on microstructure and mechanical properties of ODS tungsten heavy alloy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyong H. [Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 373-1 Kusong-dong, Yusong-gu, Taejon 305-701 (Korea, Republic of); Cha, Seung I. [International Center for Young Scientists, National Institute for Materials Science 1-1, Namiki, Tsukuba 305-0044 (Japan); Ryu, Ho J. [DUPIC, Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yusong-gu, Taejon 305-353 (Korea, Republic of); Hong, Soon H. [Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 373-1 Kusong-dong, Yusong-gu, Taejon 305-701 (Korea, Republic of)], E-mail: shhong@kaist.ac.kr

    2007-06-15

    Oxide dispersion strengthened (ODS) tungsten heavy alloys have been considered as promising candidates for advanced kinetic energy penetrator due to their characteristic fracture mode compared to conventional tungsten heavy alloy. In order to obtain high relative density, the ODS tungsten heavy alloy needs to be sintered at higher temperature for longer time, however, induces growth of tungsten grains. Therefore, it is very difficult to obtain controlled microstructure of ODS tungsten heavy alloy having fine tungsten grains with full densification. In this study, two-stage sintering process, consisted of primary solid-state sintering and followed by secondary liquid phase sintering, was introduced for ODS tungsten heavy alloys. The mechanically alloyed 94W-4.56Ni-1.14Fe-0.3Y{sub 2}O{sub 3} powders are solid-state sintered at 1300-1450 deg. C for 1 h in hydrogen atmosphere, and followed by liquid phase sintering temperature at 1465-1485 deg. C for 0-60 min. The microstructure of ODS tungsten heavy alloys showed high relative density above 97%, with contiguous tungsten grains after primary solid-state sintering. The microstructure of solid-state sintered ODS tungsten heavy alloy was changed into spherical tungsten grains embedded in W-Ni-Fe matrix during secondary liquid phase sintering. The two-stage sintered ODS tungsten heavy alloy from mechanically alloyed powders showed finer microstructure and higher mechanical properties than conventional liquid phase sintered alloy. The mechanical properties of ODS tungsten heavy alloys are dependent on the microstructural parameters such as tungsten grain size, matrix volume fraction and tungsten/tungsten contiguity, which can be controlled through the two-stage sintering process.

  9. Uticaj oksidacije aktivnog uglja sumpornom kiselinom i impregnacije bakar-sulfatom na sorpcionu sposobnost gasnog filtra za zaštitu od dejstva amonijaka / Study of the effects of activated carbon oxidation with sulphuric acid and impregnation with copper sulphate on the protection capacity of gas filters against ammonia

    Directory of Open Access Journals (Sweden)

    Sretko Ilić

    2002-01-01

    Full Text Available U radu je istraživana mogućnost poboljšanja kvaliteta aktivnog uglja (AU za upotrebu u sredstvima za ličnu zaštitu respiratornih organa od dejstva amonijaka. Uzorci komercijalnih AU oksidovani su različitim količinama rastvora sumporne kiseline, masenih koncentracija 10% i 15%. Na uzorke AU tretirane kiselinom deponovan je zatim bakar-sulfat, metodom dvostruke impregnacije rastvorom bakar-sulfata do početne vlažnosti uzorka. Impregnisani AU ispitanje u sloju u gasnom filtru prečnika 105 mm, čije su visine imale vrednosti od 29 mm do 41 mm, a uslovi su bill: ulazna koncentracija amonijaka -3,5 mg/dm3 (zapreminska koncentracija 0,5%, protok gasne smeše vazduh-amonijak - 30 dm3/min, relativna vlažnost 70% i ambijentna temperatura. Proboj je detektovan kvalitativno, pomoću indikatorskog papirića safenolftaleinom. AU impregnisan novim postupkom obezbedio je u sloju visine 29 mm vreme proboja 108 min, a 160 min u sloju visine 41 mm. / The objective of this paper has been the study of the possibility to enhance the properties of activated carbon (AC for using it in respiratory protective devices for ammonia removal from the air. The commercial AC samples were oxidized with different amounts of 10% and 15% sulphuric acid solutions. The acid treated AC samples were the loaded with copper sulphate with twofold impregnation by the incipient wetness method. The impregnated AC was tested in a packed bed in the gas filter with a diameter of 105 mm and a bed depth ranging from 29 mm to 41 mm under the following test conditions inlet concentration of ammonia was 3,5 mg/dm3, flow rate of 30 dm3/min at 70% relative humidity and ambient temperature. The breakthrough was detected qualitatively by the phenolphtalein indicator paper. The new impregnated AC reached the breaktrough time of 108 min for a 29 mm bed depth, and 160 min for a bed depth of 41 mm.

  10. DEEP DESULFURIZATION OF DIESEL FUELS BY A NOVEL INTEGRATED APPROACH

    Energy Technology Data Exchange (ETDEWEB)

    Xiaoliang Ma; Michael Sprague; Lu Sun; Chunshan Song

    2002-10-01

    In order to reduce the sulfur level in liquid hydrocarbon fuels for environmental protection and fuel cell applications, deep desulfurization of a model diesel fuel and a real diesel fuel was conducted by our SARS (selective adsorption for removing sulfur) process using the adsorbent A-2. Effect of temperature on the desulfurization process was examined. Adsorption desulfurization at ambient temperature, 24 h{sup -1} of LHSV over A-2 is efficient to remove dibenzothiophene (DBT) in the model diesel fuel, but difficult to remove 4-methyldibenzothiophene (4-MDBT) and 4,6-dimethyl-dibenzothiophene (4,6-DMDBT). Adsorption desulfurization at 150 C over A-2 can efficiently remove DBT, 4-MDBT and 4,6-DMDBT in the model diesel fuel. The sulfur content in the model diesel fuel can be reduced to less than 1 ppmw at 150 C without using hydrogen gas. The adsorption capacity corresponding to the break-through point is 6.9 milligram of sulfur per gram of A-2 (mg-S/g-A-2), and the saturate capacity is 13.7 mg-S/g-A-2. Adsorption desulfurization of a commercial diesel fuel with a total sulfur level of 47 ppmw was also performed at ambient temperature and 24 h{sup -1} of LHSV over the adsorbent A-2. The results show that only part of the sulfur compounds existing in the low sulfur diesel can be removed by adsorption over A-2 at such operating conditions, because (1) the all sulfur compounds in the low sulfur diesel are the refractory sulfur compounds that have one or two alkyl groups at the 4- and/or 6-positions of DBT, which inhibit the approach of the sulfur atom to the adsorption site; (2) some compounds coexisting in the commercial low sulfur diesel probably inhibit the interaction between the sulfur compounds and the adsorbent. Further work in determining the optimum operating conditions and screening better adsorbent is desired.

  11. Effect of yttrium addition on the microstructure and mechanical properties of ODS RAF steels

    International Nuclear Information System (INIS)

    Auger, M.A.; Castro, V. de; Leguey, T.; Tarcísio-Costa, J.; Monge, M.A.; Muñoz, A.; Pareja, R.

    2014-01-01

    An oxide dispersion strengthened (ODS) alloy with nominal composition Fe–14Cr–2W–0.3Ti–0.24Y (wt.%) was produced by mechanical alloying using elemental powders, and subsequent hot isostatic pressing. The microstructure of the material and characteristics of the oxide particle dispersion were investigated by electron microscopy. The effect of heat treatments on the microhardness and tensile properties at room temperature was also studied. The results show that a fine dispersion of Y–O-rich nanoparticles is achieved, together with larger (Cr, Ti)-rich precipitates. The absence of Ti is apparent in the majority of these nanoparticles, in contrast with reported results for ODS Ti-modified steels processed with Y 2 O 3 addition

  12. Effect of yttrium addition on the microstructure and mechanical properties of ODS RAF steels

    Energy Technology Data Exchange (ETDEWEB)

    Auger, M.A., E-mail: maria.auger@materials.ox.ac.uk [Departamento de Física, Universidad Carlos III de Madrid, Av Universidad 30, 28911 Leganés (Spain); Department of Materials, University of Oxford, Parks Road, OX1 3PH Oxford (United Kingdom); Castro, V. de; Leguey, T.; Tarcísio-Costa, J.; Monge, M.A.; Muñoz, A.; Pareja, R. [Departamento de Física, Universidad Carlos III de Madrid, Av Universidad 30, 28911 Leganés (Spain)

    2014-12-15

    An oxide dispersion strengthened (ODS) alloy with nominal composition Fe–14Cr–2W–0.3Ti–0.24Y (wt.%) was produced by mechanical alloying using elemental powders, and subsequent hot isostatic pressing. The microstructure of the material and characteristics of the oxide particle dispersion were investigated by electron microscopy. The effect of heat treatments on the microhardness and tensile properties at room temperature was also studied. The results show that a fine dispersion of Y–O-rich nanoparticles is achieved, together with larger (Cr, Ti)-rich precipitates. The absence of Ti is apparent in the majority of these nanoparticles, in contrast with reported results for ODS Ti-modified steels processed with Y{sub 2}O{sub 3} addition.

  13. Experimental study on desulfurization efficiency and gas-liquid mass transfer in a new liquid-screen desulfurization system

    International Nuclear Information System (INIS)

    Sun, Zhongwei; Wang, Shengwei; Zhou, Qulan; Hui, Shi'en

    2010-01-01

    This paper presents a new liquid-screen gas-liquid two-phase flow pattern with discarded carbide slag as the liquid sorbent of sulfur dioxide (SO 2 ) in a wet flue gas desulfurization (WFGD) system. On the basis of experimental data, the correlations of the desulfurization efficiency with flue gas flow rate, slurry flow rate, pH value of slurry and liquid-gas ratio were investigated. A non-dimensional empirical model was developed which correlates the mass transfer coefficient with the liquid Reynolds number, gas Reynolds number and liquid-gas ratio (L/G) based on the available experimental data. The kinetic reaction between the SO 2 and the carbide slag depends on the pressure distribution in this desulfurizing tower, gas liquid flow field, flue gas component, pH value of slurry and liquid-gas ratio mainly. The transient gas-liquid mass transfer involving with chemical reaction was quantified by measuring the inlet and outlet SO 2 concentrations of flue gas as well as the characteristics of the liquid-screen two-phase flow. The mass transfer model provides a necessary quantitative understanding of the hydration kinetics of sulfur dioxide in the liquid-screen flue gas desulfurization system using discarded carbide slag which is essential for the practical application. (author)

  14. Integrated photooxidative-extractive desulfurization system for fuel oil using Cu, Fe and Cu-Fe/TiO2 and eutectic based ionic liquids: Effect of calcination temperature and duration

    Science.gov (United States)

    Zaid, Hayyiratul Fatimah Mohd; Kait, Chong Fai; Mutalib, Mohamed Ibrahim Abdul

    2014-10-01

    Photocatalyts TiO2 doped with Cu, Fe and Cu-Fe metal at different calcination temperature and duration were successfully prepared and characterized. Photocatalytic oxidative desulfurization of model oil containing dibenzothiophene as the sulfur compound (100 ppm) using the prepared photocatalyst was investigated. The photocatalyst calcined at 500°C and duration of 1 h showed the best performance.

  15. Corrosion behavior of ODS steels with several chromium contents in hot nitric acid solutions

    Science.gov (United States)

    Tanno, Takashi; Takeuchi, Masayuki; Ohtsuka, Satoshi; Kaito, Takeji

    2017-10-01

    Oxide dispersion strengthened (ODS) steel cladding tubes have been developed for fast reactors. Tempered martensitic ODS steels with 9 and 11 wt% of chromium (9Cr-, 11Cr-ODS steel) are the candidate material in research being carried out at JAEA. In this work, fundamental immersion tests and electrochemical tests of 9 to 12Cr-ODS steels were systematically conducted in various nitric acid solutions at 95 °C. The corrosion rate decreased exponentially with effective solute chromium concentration (Creff) and nitric acid concentration. Addition of vanadium (V) and ruthenium (Ru) also decreased the corrosion rate. The combination of low Creff and dilute nitric acid could not avoid the active mass dissolution during active domain at the beginning of immersion, and the corrosion rate was high. Higher Creff decreased the partial anodic current during the active domain and assisted the passivation of the surface of the steel. Concentrated nitric acid and addition of Ru and V increased partial cathodic current and shifted the corrosion potential to noble side. These effects should have prevented the active mass dissolution and decreased the corrosion rate.

  16. Aerobic desulfurization of biogas by acidic biotrickling filtration in a randomly packed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Montebello, Andrea M.; Mora, Mabel; López, Luis R.; Bezerra, Tercia [Department of Chemical Engineering, School of Engineering, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain); Gamisans, Xavier [Department of Mining Engineering and Natural Resources, Universitat Politècnica de Catalunya, Bases de Manresa 61-73, 08240 Manresa (Spain); Lafuente, Javier [Department of Chemical Engineering, School of Engineering, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain); Baeza, Mireia [Department of Chemistry, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain); Gabriel, David, E-mail: david.gabriel@uab.cat [Department of Chemical Engineering, School of Engineering, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)

    2014-09-15

    Highlights: • Desulfurization of high loads of H{sub 2}S is feasible by acidic biotrickling filtration. • Robustness of the process is demonstrated in the long-term (550 d). • Biosulfur to sulfate oxidation under H{sub 2}S starvation was successfully performed. • Lower sulfate production found at acidic pH compared to that at neutral pH. • Plastic material is recommended for long-term acidic biotrickling filtration. - Abstract: Biotrickling filters for biogas desulfurization still must prove their stability and robustness in the long run under extreme conditions. Long-term desulfurization of high loads of H{sub 2}S under acidic pH was studied in a lab-scale aerobic biotrickling filter packed with metallic Pall rings. Reference operating conditions at steady-state corresponded to an empty bed residence time (EBRT) of 130 s, H{sub 2}S loading rate of 52 g S–H{sub 2}S m{sup −3} h{sup −1} and pH 2.50–2.75. The EBRT reduction showed that the critical EBRT was 75 s and the maximum EC 100 g S–H{sub 2}S m{sup −3} h{sup −1}. Stepwise increases of the inlet H{sub 2}S concentration up to 10,000 ppm{sub v} lead to a maximum EC of 220 g S–H{sub 2}S m{sup −3} h{sup −1}. The H{sub 2}S removal profile along the filter bed indicated that the first third of the filter bed was responsible for 70–80% of the total H{sub 2}S removal. The oxidation rate of solid sulfur accumulated inside the bioreactor during periodical H{sub 2}S starvation episodes was verified under acidic operating conditions. The performance under acidic pH was comparable to that under neutral pH in terms of H{sub 2}S removal capacity. However, bioleaching of the metallic packing used as support and chemical precipitation of sulfide/sulfur salts occurred.

  17. The Bgo-Od Experiment at Elsa

    Science.gov (United States)

    Bantes, B.; Bayadilov, D.; Beck, R.; Becker, M.; Bella, A.; Bieling, J.; Böse, S.; Braglieri, A.; Brinkmann, K.; Burdeynyi, D.; Curciarello, F.; de Leo, V.; di Salvo, R.; Dutz, H.; Elsner, D.; Fantini, A.; Frese, T.; Friedrick, S.; Frommberger, F.; Ganenko, V.; Gervino, G.; Ghio, F.; Giardina, G.; Girolami, B.; Glazier, D.; Goertz, S.; Gridnev, A.; Gutz, E.; Hammann, D.; Hannappel, J.; Hillert, W.; Ignatov, A.; Jahn, O.; Jahn, R.; Joosten, R.; Jude, T. C.; Klein, F.; Koop, K.; Krusche, B.; Lapik, A.; Levi Sandri, P.; Lopatin, I.; Mandaglio, G.; Messi, F.; Messi, R.; Metag, V.; Moricciani, D.; Nanova, M.; Nedorezov, V.; Noviskiy, D.; Pedroni, P.; Romaniuk, M.; Rostomyan, T.; Schaerf, C.; Schmieden, H.; Sumachev, V.; Tarakonov, V.; Vegna, V.; Vlasov, P.; Walther, D.; Watts, D.; Zaunick, H.-G.; Zimmermann, T.

    2014-01-01

    Meson photoproduction is a key tool for the experimental investigation of the nucleon excitation spectrum. To disentangle the specific couplings of resonances, in addition to the rather well measured pion and eta photoproduction channels it is mandatory to obtain information on channels involving strange and vector mesons and higher mass pseudoscalar mesons, and the associated multi-particle final states with both charged and neutral particles. In this respect, the new BGO-OD experiment at the ELSA accelerator of the University of Bonn's Physikalisches Institut provides unique instrumentation. We describe the experiment, present its status and the initial program of measurements.

  18. Behaviour of ODS Steels in Cyclic Loading

    Czech Academy of Sciences Publication Activity Database

    Kuběna, Ivo; Kruml, Tomáš; Polák, Jaroslav

    2016-01-01

    Roč. 69, č. 2 (2016), s. 309-313 ISSN 0972-2815. [International Conference on CREEP , FATIGUE and CREEP -FATIGUE INTERACTION /7./. Kalpakkam, 19.01.2016-22.01.2016] R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068; GA ČR GA15-08826S Institutional support: RVO:68081723 Keywords : ODS steels * low cycle fatigue * small fatigue crack * microstructure Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 0.533, year: 2016 http://link.springer.com/article/10.1007/s12666-015-0814-3

  19. Integrated Mg/TiO{sub 2}-ionic liquid system for deep desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Yee Cia, E-mail: gabrielle.ciayin@gmail.com [Department of Chemical Engineering, Universiti Teknologi PETRONAS, 31750 Tronoh, Perak (Malaysia); Kait, Chong Fai, E-mail: chongfaikait@petronas.com.my, E-mail: hayyiratulfatimah@yahoo.com, E-mail: cecili@petronas.com.my; Fatimah, Hayyiratul, E-mail: chongfaikait@petronas.com.my, E-mail: hayyiratulfatimah@yahoo.com, E-mail: cecili@petronas.com.my; Wilfred, Cecilia, E-mail: chongfaikait@petronas.com.my, E-mail: hayyiratulfatimah@yahoo.com, E-mail: cecili@petronas.com.my [Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, 31750 Tronoh, Perak (Malaysia)

    2014-10-24

    A series of Mg/TiO{sub 2} photocatalysts were prepared using wet impregnation method followed by calcination at 300, 400 and 500°C for 1 h. The photocatalysts were characterized using Thermal Gravimetric Analysis, Fourier-Transform Infrared Spectroscopy, X-Ray Diffraction, and Field Emission Scanning Electron Microscopy. The performance for deep desulfurization was investigated using model oil with 100 ppm sulfur (in the form of dibenzothiophene). The integrated system involves photocatalytic oxidation followed by ionic liquid-extraction processes. The best performing photocatalyst was 0.25wt% Mg loaded on titania calcined at 400°C (0.25Mg400), giving 98.5% conversion of dibenzothiophene to dibenzothiophene sulfone. The highest extraction efficiency of 97.8% was displayed by 1,2-diethylimidazolium diethylphosphate. The overall total sulfur removal was 96.3%.

  20. Electrochemical flue gas desulfurization: Reactions in a pyrosulfate-based electrolyte

    International Nuclear Information System (INIS)

    Scott, K.; Fannon, T.; Winnick, J.

    1988-01-01

    A new electrolyte has been found suitable for use in an electrochemical membrane cell for flue gas desulfurization (FGD). The electrolyte is primarily K/sub 2/S/sub 2/O/sub 7/ and K/sub 2/SO/sub 4/ with V/sub 2/O/sub 5/ as oxidation enhancer. This electrolyte has a melting point near 300/sup 0/C which is compatible with flue gas exiting the economizer of coal-burning power plants. Standard electrochemical tests have revealed high exchange current densities around 30 mA/cm/sup 2/, in the free electrolyte. Sulfur dioxide is found to be removed from simulated flue gas in a multiple-step process, the first of which is electrochemical reduction of pyrosulfate

  1. Novel cleavage and oligomerization reactions of nickel (o) complexes. Application to homogeneous deoxygenation and desulfurization

    International Nuclear Information System (INIS)

    Eisch, J.J.; Im, K.R.

    1979-01-01

    The ease of interaction of Ni(0) complexes with organic substrates has been shown to depend upon both the ligands on nickel and the solvent. The presence of α,α'-bipyridyl with the Ni(0) complex and the alkyne led to the isolation of a nickelacyclopropene, an observation in accord with the recently proposed metallocyclic pathway for the Ni(0)-catalyzed trimerization of alkynes. Allylic and benzylic ethers and epoxides have been observed to undergo oxidative insertion of Ni(0) into their C-O bonds with solvent (TMEDA > THF (tetrahydrofuran) > Et 2 O > C 6 H 6 ) and ligand (Et 3 P (tripthyl phosphine) > Ph 3 P (triphenyl phosphine); α,α'-bipy > COD) effects consistent with an electron-transfer attack by Ni(0). With such sulfur heterocycles as dibenzothiophene, phenoxathiin, phenothiazine, and thianthrene, a 1:1 admixture of (COD) 2 Ni with α,α'-bipyridyl gave as the principal product the desulfurized, ring-contracted cyclic product

  2. Integrated Mg/TiO2-ionic liquid system for deep desulfurization

    Science.gov (United States)

    Yin, Yee Cia; Kait, Chong Fai; Fatimah, Hayyiratul; Wilfred, Cecilia

    2014-10-01

    A series of Mg/TiO2 photocatalysts were prepared using wet impregnation method followed by calcination at 300, 400 and 500°C for 1 h. The photocatalysts were characterized using Thermal Gravimetric Analysis, Fourier-Transform Infrared Spectroscopy, X-Ray Diffraction, and Field Emission Scanning Electron Microscopy. The performance for deep desulfurization was investigated using model oil with 100 ppm sulfur (in the form of dibenzothiophene). The integrated system involves photocatalytic oxidation followed by ionic liquid-extraction processes. The best performing photocatalyst was 0.25wt% Mg loaded on titania calcined at 400°C (0.25Mg400), giving 98.5% conversion of dibenzothiophene to dibenzothiophene sulfone. The highest extraction efficiency of 97.8% was displayed by 1,2-diethylimidazolium diethylphosphate. The overall total sulfur removal was 96.3%.

  3. The Flakt-Hydro process: flue gas desulfurization by use of seawater

    Energy Technology Data Exchange (ETDEWEB)

    Xia, W.Z. [ABB China Limited, Shanghai (China)

    1999-07-01

    ABB's seawater scrubbing process (the Flakt-Hydro process) for flue gas desulfurization has recently triggered interest among power producers because of its simple operating principle and high reliability. The process uses seawater to absorb and neutralize sulfur dioxide in flue gases. The absorbed gas is oxidized and returned to the ocean in the form it originated in the first place, namely as dissolved sulfate salts. The process uses the seawater downstream of the power plant condensers. This paper gives an introduction to the basic principle of the process and presents some of the recent power plant applications, namely at the Paiton Private Power Project; Phase 1 (2 x 670 MWe) in Indonesia and at the Shenzhen West Power Plant, Unit 2 (300 MWe) in China.

  4. Integrated Mg/TiO2-ionic liquid system for deep desulfurization

    International Nuclear Information System (INIS)

    Yin, Yee Cia; Kait, Chong Fai; Fatimah, Hayyiratul; Wilfred, Cecilia

    2014-01-01

    A series of Mg/TiO 2 photocatalysts were prepared using wet impregnation method followed by calcination at 300, 400 and 500°C for 1 h. The photocatalysts were characterized using Thermal Gravimetric Analysis, Fourier-Transform Infrared Spectroscopy, X-Ray Diffraction, and Field Emission Scanning Electron Microscopy. The performance for deep desulfurization was investigated using model oil with 100 ppm sulfur (in the form of dibenzothiophene). The integrated system involves photocatalytic oxidation followed by ionic liquid-extraction processes. The best performing photocatalyst was 0.25wt% Mg loaded on titania calcined at 400°C (0.25Mg400), giving 98.5% conversion of dibenzothiophene to dibenzothiophene sulfone. The highest extraction efficiency of 97.8% was displayed by 1,2-diethylimidazolium diethylphosphate. The overall total sulfur removal was 96.3%

  5. Water oxidation by photosystem II: H(2)O-D(2)O exchange and the influence of pH support formation of an intermediate by removal of a proton before dioxygen creation.

    Science.gov (United States)

    Gerencsér, László; Dau, Holger

    2010-11-30

    Understanding the chemistry of photosynthetic water oxidation requires deeper insight into the interrelation between electron transfer (ET) and proton relocations. In photosystem II membrane particles, the redox transitions of the water-oxidizing Mn complex were initiated by nanosecond laser flashes and monitored by absorption spectroscopy at 360 nm (A(360)). In the oxygen evolution transition (S(3) + hν → S(0) + O(2)), an exponential decrease in A(360) (τ(O(2)) = 1.6 ms) can be assigned to Mn reduction and O(2) formation. The corresponding rate-determining step is the ET from the Mn complex to a tyrosine radical (Y(Z)(ox)). We find that this A(360) decrease is preceded by a lag phase with a duration of 170 ± 40 μs (τ(lag) at pH 6.2), indicating formation of an intermediate before ET and O-O bond formation and corroborating results obtained by time-resolved X-ray spectroscopy. Whereas τ(O(2)) exhibits a minor kinetic isotope effect and negligible pH dependence, formation of the intermediate is slowed significantly both in D(2)O (τ(lag) increase of ∼140% in D(2)O) and at low pH (τ(lag) of 30 ± 20 μs at pH 7.0 vs τ(lag) of 470 ± 80 μs at pH 5.5). These findings support the fact that in the oxygen evolution transition an intermediate is created by deprotonation and removal of a proton from the Mn complex, after Y(Z)(ox) formation but before the onset of electron transfer and O-O bond formation.

  6. Microbial Desulfurization of a Crude Oil Middle-Distillate Fraction: Analysis of the Extent of Sulfur Removal and the Effect of Removal on Remaining Sulfur

    Science.gov (United States)

    Grossman, M. J.; Lee, M. K.; Prince, R. C.; Garrett, K. K.; George, G. N.; Pickering, I. J.

    1999-01-01

    Rhodococcus sp. strain ECRD-1 was evaluated for its ability to desulfurize a 232 to 343°C middle-distillate (diesel range) fraction of Oregon basin (OB) crude oil. OB oil was provided as the sole source of sulfur in batch cultures, and the extent of desulfurization and the chemical fate of the residual sulfur in the oil after treatment were determined. Gas chromatography (GC), flame ionization detection, and GC sulfur chemiluminesce detection analysis were used to qualitatively evaluate the effect of Rhodococcus sp. strain ECRD-1 treatment on the hydrocarbon and sulfur content of the oil, respectively. Total sulfur was determined by combustion of samples and measurement of released sulfur dioxide by infrared absorption. Up to 30% of the total sulfur in the middle distillate cut was removed, and compounds across the entire boiling range of the oil were affected. Sulfur K-edge X-ray absorption-edge spectroscopy was used to examine the chemical state of the sulfur remaining in the treated OB oil. Approximately equal amounts of thiophenic and sulfidic sulfur compounds were removed by ECRD-1 treatment, and over 50% of the sulfur remaining after treatment was in an oxidized form. The presence of partially oxidized sulfur compounds indicates that these compounds were en route to desulfurization. Overall, more than two-thirds of the sulfur had been removed or oxidized by the microbial treatment. PMID:9872778

  7. The effect of organisational context on organisational development (OD interventions

    Directory of Open Access Journals (Sweden)

    Sanjana Brijball Parumasur

    2012-05-01

    Research purpose: This article examines national and international OD practices. It assesses the effect of diverse cultures and cultural values for determining the effectiveness of OD interventions. Motivation for the study: Most organisational change and development programmes fail and only a few result in increased competitiveness, improvements and profitability. This emphasises the need for change interventions to give sufficient attention to leadership, cultures, managing change and adopting context-based OD interventions. Research design, approach and method: This article is a literature review of the current trends and research in the area of OD interventions. It synthesises the influence that cultures and cultural orientations have on determining which OD intervention strategies organisations should adopt in different cultures. Main findings: The analysis emphasises how important it is to achieve congruence between the OD interventions organisations select and their local cultures. Practical/managerial implications: It is important to note the evolving nature of the political and economic climates that influence national cultures and that they emphasise that interventions that reflect OD values, which are tailor-made and shaped to the needs of local cultures, are necessary. Contribution/value-add: This study links various OD interventions to Hofstede’s dimensions for differentiating national cultures. It provides guidelines for aligning the practices and techniques of OD to the values and cultures of the organisations and societies in which they are to be implemented.

  8. Effect of HIP temperature and cooling rate on microstructure and hardness of joints for ODS-RAFM steels and JLF-1 steel

    International Nuclear Information System (INIS)

    Fu, Haiying; Nagasaka, Takuya; Muroga, Takeo; Kimura, Akihiko; Ukai, Shigeharu

    2016-01-01

    Dissimilar-metal joints between ODS-RAFM (oxide-dispersion-strengthened reduced activation ferritic/martensitic) steels and JLF-1 steel were fabricated by hot isostatic pressing (HIP) at 1000 - 1100degC with a cooling rate of 5degC/min. After the HIP, it was always quenched martensite for JLF-1 steel. However, coarse precipitates were found in 9Cr-ODS. Additional annealing experiments to simulate HIP conditions were conducted for 9Cr-ODS with cooling rate ranged from 0.5 to 36degC/min at 800 - 1100degC. The results showed that, to form quenched martensite for 9Cr-ODS, the HIP temperature should be above 1000degC with cooling rate no less than 25dgeC/min. When the cooling rate is increased to 36degC/min, the microstructure of 9Cr-ODS is quenched martensite with precipitate size similar as that before HIP. If the limitation of precipitate size in 9Cr-ODS is 0.2 µm, HIP temperature above 1050degC with cooling rate no less than 30degC/min is needed. In this case, post-weld heat treatment (PWHT) with only tempering is necessary to recover the microstructure of 9Cr-ODS to tempered martensite. For 12Cr-ODS, the HIP temperature and cooling rate has no effect on hardness and precipitate size. PWHT is not necessary for the single-metal joint of 12Cr-ODS from the view point of precipitation control. However, for the dissimilar-metal joints between ODS-RAFM steels and JLF-1 steel, the PWHT condition should be comprehensively determined by considering microstructural evolution of each part in the joints after HIP. (author)

  9. Microstructural Characterization of Y{sub 2}O{sub 3} ODS-Fe-Cr Model Alloy s

    Energy Technology Data Exchange (ETDEWEB)

    De Castro, V.; Jenkins, M.L. [Oxford Univ., Dept. of Materials (United Kingdom); Leguey, T.; Mufioz, A.; Pareja, R.; Monge, M.A. [Madrid Univ. Carlos 3, Dept. de Fisica (Spain)

    2007-07-01

    Full text of publication follows: Reduced activation ferritic/martensitic (RAFM) steels with Cr contents ranging between 9-12 wt% are promising candidates for use as structural materials in future fusion reactors. They are likely to be superior to austenitic steels because of their better thermal properties and higher swelling resistance. A major concern of these materials is their maximum service temperature, as this determines the overall efficiency of the reactor. It has been demonstrated that one way to increase this temperature is to homogeneously disperse hard nano-sized oxide particles, such as Y{sub 2}O{sub 3}, into the steel matrix. Oxide dispersion strengthened (ODS) steels produced by mechanical milling and hot isostatic pressing (HIP ) are considered as potential structural materials for fusion reactors. In Europe, efforts have been focused on the ODS-RAFM-9CrW steel EUROFER. These ODS steels show good tensile and creep properties, acceptable ductility, but poor impact properties. Microstructural characterization of real steels, especially of the structures of oxide/steel matrix interfaces which play an important role in the performance of the material, is a difficult task. In the present work we have fabricated and characterised a simpler model ODS system based on a Fe-Cr binary alloy, in the belief that this will help us better to understand complex ODS-RAFM steels. Two Fe-12wt% Cr batches, one containing 0.3 wt% Y{sub 2}O{sub 3} and the other Y{sub 2}O{sub 3} free have been produced by milling plus compaction by HIP. These materials are being characterized by X-ray diffraction, electron microscopy and atom probe field ion microscopy. Results will be compared with those obtained for ODS-EUROFER produced under the same conditions. (authors)

  10. Defining clusters in APT reconstructions of ODS steels.

    Science.gov (United States)

    Williams, Ceri A; Haley, Daniel; Marquis, Emmanuelle A; Smith, George D W; Moody, Michael P

    2013-09-01

    Oxide nanoclusters in a consolidated Fe-14Cr-2W-0.3Ti-0.3Y₂O₃ ODS steel and in the alloy powder after mechanical alloying (but before consolidation) are investigated by atom probe tomography (APT). The maximum separation method is a standard method to define and characterise clusters from within APT data, but this work shows that the extent of clustering between the two materials is sufficiently different that the nanoclusters in the mechanically alloyed powder and in the consolidated material cannot be compared directly using the same cluster selection parameters. As the cluster selection parameters influence the size and composition of the clusters significantly, a procedure to optimise the input parameters for the maximum separation method is proposed by sweeping the d(max) and N(min) parameter space. By applying this method of cluster parameter selection combined with a 'matrix correction' to account for trajectory aberrations, differences in the oxide nanoclusters can then be reliably quantified. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. 46 CFR 280.9 - Special rules for last year of ODS agreement.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Special rules for last year of ODS agreement. 280.9... LINER OPERATORS § 280.9 Special rules for last year of ODS agreement. (a) Reduction in payment of ODS. ODS payable during the last year of any ODS agreement shall be reduced, as provided in paragraph (b...

  12. The microstructure and mechanical properties of Al-containing 9Cr ODS ferritic alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Guangming [School of Materials Science and Engineering, University of Science and Technology, Beijing, Beijing 100083 (China); Department of Nuclear, Plasma and Radiological Engineering, University of Illinois at Urbana-Champaign, IL 61801 (United States); Zhou, Zhangjian, E-mail: zhouzhj@mater.ustb.edu.cn [School of Materials Science and Engineering, University of Science and Technology, Beijing, Beijing 100083 (China); Mo, Kun [Nuclear Engineering Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Wang, Pinghuai [Fusion Reactor & Materials Division, Southwestern Institute of Physics, Chengdu, Sichuan 610041 (China); Miao, Yinbin [Department of Nuclear, Plasma and Radiological Engineering, University of Illinois at Urbana-Champaign, IL 61801 (United States); Li, Shaofu; Wang, Man [School of Materials Science and Engineering, University of Science and Technology, Beijing, Beijing 100083 (China); Liu, Xiang [Department of Nuclear, Plasma and Radiological Engineering, University of Illinois at Urbana-Champaign, IL 61801 (United States); Gong, Mengqiang [School of Materials Science and Engineering, University of Science and Technology, Beijing, Beijing 100083 (China); Almer, Jonathan [X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Stubbins, James F. [Department of Nuclear, Plasma and Radiological Engineering, University of Illinois at Urbana-Champaign, IL 61801 (United States)

    2015-11-05

    In this study, a 9Cr oxide-dispersion strengthened (ODS) alloy with additional corrosion resistant element Al was fabricated by mechanical alloying (MA) and hot pressing (HP) to explore the impact of Al on the microstructure and mechanical property of a 9Cr ODS alloy. It is found that the Al completely dissolved into the Fe–Cr matrix after milling for 30 h. The minor phases in the Al-containing 9Cr ODS ferritic alloy were investigated by a high-energy X-ray, and were identified to be orthorhombic-YAlO{sub 3} (YAP), bcc-Y{sub 3}Al{sub 5}O{sub 12} (YAG), monoclinic-Al{sub 2}Y{sub 4}O{sub 9} (YAM), and hexagonal-YAlO{sub 3} (YAH). These phases were further confirmed by selected area diffraction pattern (SADP), energy dispersive spectroscopy (EDS), and high resolution transmission electron microscopy (HRTEM). In addition, their volume fractions were also calculated from the integrated intensities. According to the analysis of the particles and their formation sequences, the larger particles (greater than 100 nm) are identified as mainly YAG and Al{sub 2}O{sub 3} particles, while the particles with small size (less than 30 nm) are likely primarily YAM, YAH, and YAP particles. The yielding strength (YS) and ultimate tensile strength (UTS) at RT are 563 MPa and 744 MPa, respectively, while the YS and UTS at 700 °C are 245 MPa and 276 MPa, respectively. Although the addition Al in ODS alloys decreases the strength at RT, the values at high temperature are similar to those obtained for 9Cr ODS alloys strengthened by fine Y–Ti–O particles. - Graphical abstract: Synchrotron X-ray diffraction line profile of the 9CrAl ODS alloy; (Ferrite matrix phases, along with minor phases, orthorhombic YAlO{sub 3} (yttrium aluminum perovskite, YAP), bcc Y{sub 3}Al{sub 5}O{sub 12} (yttrium aluminum garnet, YAG), monoclinic Al{sub 2}Y{sub 4}O{sub 9} (yttrium aluminum monoclinic, YAM), and hexagonal YAlO{sub 3} (yttium aluminum hexagonal, YAH) were recognized.). - Highlights: • The

  13. 3D CFD Modeling of the LMF System: Desulfurization Kinetics

    Science.gov (United States)

    Cao, Qing; Pitts, April; Zhang, Daojie; Nastac, Laurentiu; Williams, Robert

    A fully transient 3D CFD modeling approach capable of predicting the three phase (gas, slag and steel) fluid flow characteristics and behavior of the slag/steel interface in the argon gas bottom stirred ladle with two off-centered porous plugs (Ladle Metallurgical Furnace or LMF) has been recently developed. The model predicts reasonably well the fluid flow characteristics in the LMF system and the observed size of the slag eyes for both the high-stirring and low-stirring conditions. A desulfurization reaction kinetics model considering metal/slag interface characteristics is developed in conjunction with the CFD modeling approach. The model is applied in this study to determine the effects of processing time, and gas flow rate on the efficiency of desulfurization in the studied LMF system.

  14. Hot rolling and annealing effects on the microstructure and mechanical properties of ODS austenitic steel fabricated by electron beam selective melting

    Science.gov (United States)

    Gao, Rui; Ge, Wen-jun; Miao, Shu; Zhang, Tao; Wang, Xian-ping; Fang, Qian-feng

    2016-03-01

    The grain morphology, nano-oxide particles and mechanical properties of oxide dispersion strengthened (ODS)-316L austenitic steel synthesized by electron beam selective melting (EBSM) technique with different post-working processes, were explored in this study. The ODS-316L austenitic steel with superfine nano-sized oxide particles of 30-40 nm exhibits good tensile strength (412 MPa) and large total elongation (about 51%) due to the pinning effect of uniform distributed oxide particles on dislocations. After hot rolling, the specimen exhibits a higher tensile strength of 482 MPa, but the elongation decreases to 31.8% owing to the introduction of high-density dislocations. The subsequent heat treatment eliminates the grain defects induced by hot rolling and increases the randomly orientated grains, which further improves the strength and ductility of EBSM ODS-316L steel.

  15. Influence of HIP pressure on tensile properties of a 14Cr ODS ferritic steel

    Energy Technology Data Exchange (ETDEWEB)

    Oksiuta, Z., E-mail: z.oksiuta@pb.edu.pl [Bialystok Technical University, Mechanical Department, Wiejska 45c, 15-351 Bialystok (Poland); Ozieblo, A.; Perkowski, K.; Osuchowski, M. [Institute of Ceramics and Building Materials, Postępu 9, 02-676 Warsaw (Poland); Lewandowska, M. [Warsaw University of Technology, Woloska 141, 02-504 Warsaw (Poland)

    2014-02-15

    Highlights: • The HIPping parameters of the 14Cr–2W–0.3Ti–0.3Y{sub 2}O{sub 3} ODS steel powder were investigated. • The density and microstructure of the tested specimens after HIPping were studied. • The mechanical properties, high temperature tensile tests, were performed. • Residual porosity was observed in all tested specimens. • HIPping pressure has negligible influence on the strength of the ODS steel however improves material ductility. - Abstract: An oxide dispersion strengthened ferritic steel with a nominal composition of Fe–14Cr–2W–0.3Ti–0.3Y{sub 2}O{sub 3} (in wt.%) was consolidated by hot isostatic pressing at 1150 °C under various pressures in the range of 185–300 MPa for 3 h. The microstructure, microhardness and high temperature tensile properties of the steel were investigated. With increasing compaction pressure the density of specimens also increased, however OM and SEM observations revealed residual porosity in all tested specimens and similar ferritic microstructure with bimodal-like grains and numerous of large oxide particles, located at the grain boundaries. Mechanical testing revealed that compaction pressure has negligible influence on the hardness and tensile strength of the ODS steel, however improves the material ductility.

  16. Influence of HIP pressure on tensile properties of a 14Cr ODS ferritic steel

    International Nuclear Information System (INIS)

    Oksiuta, Z.; Ozieblo, A.; Perkowski, K.; Osuchowski, M.; Lewandowska, M.

    2014-01-01

    Highlights: • The HIPping parameters of the 14Cr–2W–0.3Ti–0.3Y 2 O 3 ODS steel powder were investigated. • The density and microstructure of the tested specimens after HIPping were studied. • The mechanical properties, high temperature tensile tests, were performed. • Residual porosity was observed in all tested specimens. • HIPping pressure has negligible influence on the strength of the ODS steel however improves material ductility. - Abstract: An oxide dispersion strengthened ferritic steel with a nominal composition of Fe–14Cr–2W–0.3Ti–0.3Y 2 O 3 (in wt.%) was consolidated by hot isostatic pressing at 1150 °C under various pressures in the range of 185–300 MPa for 3 h. The microstructure, microhardness and high temperature tensile properties of the steel were investigated. With increasing compaction pressure the density of specimens also increased, however OM and SEM observations revealed residual porosity in all tested specimens and similar ferritic microstructure with bimodal-like grains and numerous of large oxide particles, located at the grain boundaries. Mechanical testing revealed that compaction pressure has negligible influence on the hardness and tensile strength of the ODS steel, however improves the material ductility

  17. Monolithic Approach to Oxide Dispersion Strengthened Aluminum, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Nassau Stern Company is investigating an approach for manufacturing oxide dispersion strengthened (ODS) aluminum in bulk rather than powder form. The approach...

  18. Application of wasted sea-shell to desulfurizer in fluidized bed coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Naruse, Ichiro; Saito, Katsuhiro; Murakami, Takahiro

    1999-07-01

    Almost all wasted seashells consist of CaCo{sub 3}, and are similar to limestone. It would be proposed that the seashell could be applied as a desulfurizer. In this study, desulfurization characteristics of the seashell are fundamentally studied by using a thermobalance and a bubbling fluidized coal combustor with comparing the results obtained by limestone as a reference. Under the constant calcination temperature, the desulfurization efficiency for the seashells attains more than about 70% after the desulfurization period of 30 h. For the limestones, on the other hand, the desulfurization efficiency becomes only 38%. Under practical conditions of fluidized bed coal combustion, the desulfurization efficiency for the seashells also indicates higher value than that for the limestones. The desulfurization efficiency depends on the pore size distribution of CaO rather than its specific surface area. The mean pore size of the calcined seashell is about 10 times as large as that of the calcined limestones. from Scanning Electro-Microscope (SEM) photos of the surface of CaCO{sub 3}, CaO and the sulfurized particles of the seashells the large pores can be observed. In measuring cross-sectional distribution of sulfur inside the particles by using an Energy Dispersed X-ray (EDX) system, the sulfur in the sulfurized particle of limestone is only trapped near the particle surface. For the seashells, whereas, the sulfur is distributed over the whole body of particle. Desulfurization efficiency for the limestone, into which some alkali metal compounds are added, increases with increasing the concentration of alkali metal compounds added. In order of increasing effect the key elemental species to enhance the desulfurization activities are Cl, Na and K. Alkali metal compounds can enhance the desulfurization activities, due to solution of CaO in molten NaCl. This is one of the reasons why the desulfurization efficiency for the seashells improves.

  19. Combined method for reducing emission of sulfur dioxide and nitrogen oxides from thermal power plants

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Grachev, S.P.

    1991-11-01

    Discusses the method developed by the Fossil Energy Research Corp. in the USA for combined desulfurization and denitrification of flue gases from coal-fired power plants. The method combines two methods tested on a commercial scale: the dry additive method for suppression of sulfur dioxide and the selective noncatalytic reduction of nitrogen oxides using urea (the NOXOUT process). The following aspects of joint flue gas desulfurization and denitrification are analyzed: flowsheets of the system, chemical reactions and reaction products, laboratory tests of the method and its efficiency, temperature effects on desulfurization and denitrification of flue gases, effects of reagent consumption rates, operating cost, efficiency of the combined method compared to other conventional methods of separate flue gas desulfurization and denitrification, economic aspects of flue gas denitrification and desulfurization. 4 refs.

  20. Super ODS steel R and D for fuel cladding of next generation nuclear systems. 2) Effect of minor alloying elements

    International Nuclear Information System (INIS)

    Ohnuki, S.; Hashimoto, N.; Ukai, S.; Kimura, A.; Inoue, Masaki; Kaito, Takeji; Fujisawa, T.; Okuda, T.; Abe, F.

    2009-01-01

    For development of advanced ferritic ODS steels including high concentration of Cr and Al, the effect of minor alloying elements on fine dispersion of oxide particle was investigated. Microstructural analysis for Fe-16Cr-4Al-mY 2 O 3 -nZr or mHf due to TEM indicated that 0.3Zr or 0.6Hf are the optimum concentration. The mechanism of nano-sized oxide formation was also discussed. (author)

  1. Effects of Mn addition on microstructures and mechanical properties of 10Cr ODS ferritic/martensitic steels

    International Nuclear Information System (INIS)

    Jin, Hyun Ju; Kim, Tae Kyu

    2014-01-01

    Ferritic/martensitic (FM) steels are very attractive for the structural materials of fast fission reactors such as a sodium cooled fast reactor (SFR) owing to their excellent irradiation resistance to a void swelling, but are known to reveal an abrupt loss of their creep and tensile strengths at temperatures above 600 .deg. C. Accordingly, high temperature strength should be considerably improved for an application of the FM steel to the structural materials of SFR. Oxide dispersion strengthened (ODS) FM steels are considered to be promising candidate materials for high- temperature components operating in severe environments such as nuclear fusion and fission systems due to their excellent high temperature strength and radiation resistance stemming from the addition of extremely thermally stable oxide particles dispersed in the ferritic/martensitic matrix.. To develop an advanced ODS steel for core structural materials for next generation nuclear reactor system applications, it is important to optimize its compositions to improve the high temperature strength and radiation resistance. This study investigates effects of Mn addition on microstructures and mechanical properties of 10Cr ODS FM steel. For this, two 10 Cr ODS FM steels were prepared by mechanical alloying (MA), hot isostatic pressing (HIP), and hot rolling process. Tensile tests were carried out at room temperature and 700 .deg. C to evaluate the influences of the Mn element on the mechanical properties. The microstructures were observed using SEM, electron back-scatter diffraction (EBSD) and transmission electron microscopy (TEM) with energy dispersive spectroscopy (EDS). In the present study, the effects of Mn addition on the microstructure and mechanical properties of ODS FM steels were investigated. The ODS FM steels were manufactured by the MA, HIP and hot-rolling processes

  2. Annealing effect on the microstructure and magnetic properties of 14%Cr-ODS ferritic steel

    International Nuclear Information System (INIS)

    Ding, H.L.; Gao, R.; Zhang, T.; Wang, X.P.; Fang, Q.F.; Liu, C.S.

    2015-01-01

    Graphical abstract: TEM images of microstructure for 14%Cr-ODS ferritic steel annealed for 2 h at different temperatures: (a) 600 °C, (b) 800 °C, (c) 950 °C, and (d) 1150 °C, and the evolution trends of coercivity field (H_C) and Vickers microhardness for samples annealed at above temperatures for 2 h and 50 h. - Highlights: • The thermal stability of annealed 14%Cr-ODS ferritic steel was investigated. • The particle size keeps fairly constant with increasing annealing temperature. • The grain size is still 2–4 μm even after annealing for 50 h at 1150 °C. • The hardness and H_C are almost unchanged after annealing from 800 °C to 1150 °C. - Abstract: The microstructure and magnetic properties of the 14%Cr oxide dispersion strengthened (ODS) ferritic steel fabricated by sol–gel and HIP method were investigated by annealing in vacuum for 2 h (at 300, 600, 800, 950 and 1150 °C) and 50 h (at 600, 800, 950 and 1150 °C). Microstructure analysis shows that as the annealing temperature increases, the size of oxide nanoparticles becomes smaller and their dispersion in matrix becomes more homogeneous. Grain size remains stable when the annealing temperature is below 800 °C, while above 800 °C, grain size grows with the increasing annealing temperature and time. The Vickers microhardness and coercivity (H_C) display almost similar evolution trend with annealing temperature for 2 h and 50 h. No obvious recrystallization appears after 1150 °C annealing, which indicates the high microstructural stability of 14%Cr-ODS ferritic steel. The possible mechanism for above behaviors is discussed in this paper.

  3. 2nd Gen FeCrAl ODS Alloy Development For Accident-Tolerant Fuel Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Dryepondt, Sebastien N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Massey, Caleb P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Edmondson, Philip D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-08-01

    Extensive research at ORNL aims at developing advanced low-Cr high strength FeCrAl alloys for accident tolerant fuel cladding. One task focuses on the fabrication of new low Cr oxide dispersion strengthened (ODS) FeCrAl alloys. The first Fe-12Cr-5Al+Y2O3 (+ ZrO2 or TiO2) ODS alloys exhibited excellent tensile strength up to 800 C and good oxidation resistance in steam up to 1400 C, but very limited plastic deformation at temperature ranging from room to 800 C. To improve alloy ductility, several fabrication parameters were considered. New Fe-10-12Cr-6Al gas-atomized powders containing 0.15 to 0.5wt% Zr were procured and ball milled for 10h, 20h or 40h with Y2O3. The resulting powder was then extruded at temperature ranging from 900 to 1050 C. Decreasing the ball milling time or increasing the extrusion temperature changed the alloy grain size leading to lower strength but enhanced ductility. Small variations of the Cr, Zr, O and N content did not seem to significantly impact the alloy tensile properties, and, overall, the 2nd gen ODS FeCrAl alloys showed significantly better ductility than the 1st gen alloys. Tube fabrication needed for fuel cladding will require cold or warm working associated with softening heat treatments, work was therefore initiated to assess the effect of these fabrications steps on the alloy microstructure and properties. This report has been submitted as fulfillment of milestone M3FT 16OR020202091 titled, Report on 2nd Gen FeCrAl ODS Alloy Development for the Department of Energy Office of Nuclear Energy, Advanced Fuel Campaign of the Fuel Cycle R&D program.

  4. Atom probe characterization of nano-scaled features in irradiated Eurofer and ODS Eurofer steel

    International Nuclear Information System (INIS)

    Rogozkin, S.; Aleev, A.; Nikitin, A.; Zaluzhnyi, A.; Vladimirov, P.; Moeslang, A.; Lindau, R.

    2009-01-01

    Outstanding performance of oxide dispersion strengthened (ODS) steels at high temperatures and up to high doses allowed to consider them as potential candidates for fusion and fission power plants. At the same time their mechanical parameters strongly correlate with number density of oxide particles and their size. It is believed that fine particles are formed at the last stage of sophisticated production procedures and play a crucial role in higher heat- and radiation resistance in comparison with conventional materials. However, due to their small size - only few nanometers, characterization of such objects requires considerable efforts. Recent study of ODS steel by tomographic atom probe, the most appropriate technique in this case, shown considerable stability of these particles under high temperatures and ion-irradiation. However, these results were obtained for 12/14% Cr with addition of 0.3% Y 2 O 3 and titanium which is inappropriate in case of ODS Eurofer 97 and possibility to substitute neutron by ion irradiation is still under consideration. In this work effect of neutron irradiation on nanostructure behaviour of ODS Eurofer are investigated. Irradiation was performed on research reactor BOR-60 in SSC RF RIAR (Dimitrovgrad, Russia) up to 30 dpa at 280 deg. C and 580 deg. C. Recent investigation of unirradiated state revealed high number density of nano-scaled features (nano-clusters) even without addition of Ti in steel. It was shown that vanadium played significant role in nucleation process and core of nano-clusters was considerably enriched with it. In irradiated samples solution of vanadium in matrix was observed while the size of particles stayed practically unchanged. Also no nitrogen was detected in these particles in comparison with unirradiated state where bond energy of N with V was considered to be high as VN 2+ ions were detected on mass-spectra. (author)

  5. OD in Schools: The State of the Art. Vol. II: Review of Research on OD. Final Report.

    Science.gov (United States)

    Fullan, Michael; And Others

    The purpose of this document, the second of a five-volume series, was to analyze the various reviews of organizational development (OD) in general, and case studies of school districts in particular, in order to synthesize information about OD as it applies to schools. The review is organized into four main categories: (1) values, themes, and…

  6. Atom probe characterization of yttria particles in ODS Eurofer steel

    International Nuclear Information System (INIS)

    Aleev, A.A.; Zaluzhny, A.G.; Nikitin, A.A.; Rogozhkin, S.V.; Iskandarov, N.A.; Vladimirov, P.; Moeslang, A.; Lindau, R.; Klimenkov, M.

    2009-01-01

    Oxide dispersion strengthened steels exhibit higher temperature and radiation resistance than conventionally produced ferritic/martensitic steels. Such behaviour, as believed, is mainly caused by presence of highly dispersed and extremely stable oxide particles with sizes of few nanometers. It was shown that the most promising oxide additive was yttria (Y 2 O 3 ) and as mechanical parameters were strongly depended on size and number density of formed peculiarities it is required to reduce their dimensions to few nanometers and drastically increase their number. At present, considerable effort is focused on investigation of behaviour and properties of such particles. Recent studies of Eurofer ODS steel (9%-CrWVTa) by SANS and PoAS revealed the presence of high number density structural peculiarities with size approximately one nanometer. At the same time, previous studies by TEM identified only high number of small (5-10 nm) Y 2 O 3 particles. So, the purpose of this work was to look into this material by means of tomographic atom probe and find out the chemistry and origin of peculiarities with sizes less than 5 nm. These investigations revealed fine (∼ 2 nm) particles that were enriched not only in yttrium and oxygen but also in vanadium and nitrogen. Concentration of vanadium in them is approximately at the same level as yttrium. Moreover, some particles were found to be enriched in only three or even two elements mentioned above. However, total concentration of chemical elements in these particles is considerably less than that of iron. Estimated number density for detected particles is (1 / 5) x 10 23 m -3 . (author)

  7. Oxide nanoparticles in an Al-alloyed oxide dispersion strengthened steel: crystallographic structure and interface with ferrite matrix

    DEFF Research Database (Denmark)

    Zhang, Zhenbo; Pantleon, Wolfgang

    2017-01-01

    Oxide nanoparticles are quintessential for ensuring the extraordinary properties of oxide dispersion strengthened (ODS) steels. In this study, the crystallographic structure of oxide nanoparticles, and their interface with the ferritic steel matrix in an Al-alloyed ODS steel, i.e. PM2000, were...

  8. Super ODS steels R and D for fuel cladding on next generation nuclear systems. 8) Ion irradiation effects at elevated temperatures

    International Nuclear Information System (INIS)

    Kishimoto, Hirotatsu; Kasada, Ryuta; Kimura, Akihiko; Inoue, Masaki; Okuda, Takanari; Abe, Fujio; Ohnuki, Somei; Fujisawa, Toshiharu

    2009-01-01

    The Super ODS steels, having excellent high-temperature strength and highly corrosion resistant, are considered to increase the energy efficiency by higher temperature operation and extend the lifetime of next generation nuclear systems. High-temperature strength of the ODS steels strongly depends on the dispersion of oxide particles, therefore, the irradiation effect on the dispersed oxides is critical in the material development. In the present research, ion irradiation experiments were employed to investigate microstructural stability under the irradiation environment at elevated temperatures. Ion irradiation experiments were performed with 6.4 MeV Fe ions irradiated at 650degC up to a nominal displacement damage of 60 dpa. Microstructural investigation was carried out using TEM and EDX. No significant change of grains and grain boundaries was observed by TEM investigation after the ion irradiation. Main oxide particles in the 16Cr-4Al-0.1Ti (SOC-1) ODS steel were (Y, Al) complex oxides. (Y, Ti) complex oxides were in 16Cr-0.1Ti (SOC-5) and 15.5Cr-2W-0.1Ti (SOCP-3). (Y, Zr) complex oxides were in 15.5Cr-4Al-0.6Zr (SOCP-1). No significant modification of these complex oxides was detected after the ion irradiation up to 60 dpa at 650degC. The stable complex oxides are considered to keep highly microstructural stability of the Super ODS steels under the irradiation environments. (author)

  9. Process of desulfurizing dephenolating, and cracking raw pitch obtained by dry distilling lignite, shale, etc

    Energy Technology Data Exchange (ETDEWEB)

    1932-12-21

    A process is described of desulfurizing, dephenelating, and cracking the dry pitch obtained by dry distillation of lignite, bituminous shale, asphaltic rocks, and peat and fossil coals, that is characterized by the raw material being distilled in a retort together with calcium oxide, the vapors escaping from the still being compelled to pass through a catalyst tube containing calcium oxide mixed with other metallic oxide, the catalyst being helped by suitable heating to a temperature higher than that of the retort mentioned. For the purpose of lessening the quantity of phenolic groups contained in the raw tar to eliminate a great part of the sulfur belonging to the thiophenols and hydrogen sulfide without removing the organic radical to which they are attached, to accomplish a pyrogenic dissociation at the temperature of distillation of the pitch by means of using bone acid (phosphoric) to obtain a greater yield of light hydrocarbon from heavy hydrocarbons. Another purpose is the elimination of sulfur and thiophene and whatever neutral sulfur is contained in the primary pitch, by means of iron sulfate and copper in the anhydrous state or by means of other sulfates whose metals have the ability to form sulfides with sulfur.

  10. Reactive Adsorption Desulfurization by Nanocrystalline ZnO/Zeolite A Molecular Sieves

    Directory of Open Access Journals (Sweden)

    Nada Sadoon Ahmedzeki

    2017-09-01

    Full Text Available Nanocrystalline ZnO/Zeolite type A composite was prepared by simple method of operation by . the precipitation of zinc oxide and loading on zeolite 5A in one step. Characterization was made by X-ray diffraction (XRD, X-ray fluorescence(XRF, N2 adsorption- desorption for BET surface area, and Atomic force microscopy (AFM. Results showed that zinc oxide was loaded on zeolite as noticed by the characteristic peaks and was of nano scale having an average diameter of 88.57nm. The percentage loading of ZnO on zeolite A was 28.37% and the surface area was 222m2/g. The activity of the prepared catalyst was examined in the desulfurization of double hydrogenated diesel fuel. The process was investigated in a controlled autoclave with temperature range studied 100220 oC. Results indicated an oxidation of thiophenic compounds on the surface of the catalyst coupled with adsorption. About 35% reduction was obtained and the capacity was 10.56 mg S/g catalyst.

  11. Use of Flue Gas Desulfurization (FGD) Gypsum as a Heavy Metal Stabilizer in Contaminated Soils

    Science.gov (United States)

    Flue Gas Desulfurization (FGD) gypsum is a synthetic by-product generated from the flue gas desulfurization process in coal power plants. It has several beneficial applications such as an ingredient in cement production, wallboard production and in agricultural practice as a soil...

  12. Progress on flue gas desulfurization and denitration with electron beam irradiation in CAEP

    International Nuclear Information System (INIS)

    Ren Min; Wang Baojian; Yang Ruizhuang; Huang Wenfeng; He Xiaohai; Mao Benjiang

    2005-01-01

    The first pilot plant with electron beam irradiation for desulfurization and denitration of flue gas in China and the experimental results based on the pilot plant are briefly introduced in this paper. The FGD (flue gas desulfurization) demonstration installation designed by CAEP (China Academy of Engineering Physics) in Beijing Jingfeng Thermal Powe Co., Ltd. is recommended. (author)

  13. Inhibition of carbon disulfide on bio-desulfurization in the process of ...

    African Journals Online (AJOL)

    Biological desulfurization is a novel technology for the removal of hydrogen sulfide from some biogas or sour gas, in which there are always a certain amounts of carbon disulfide together with much hydrogen sulfide. Nowadays, carbon disulfide is found to have negative effect on the biological desulfurization, but seldom ...

  14. Photocatalytic Desulfurization of Waste Tire Pyrolysis Oil

    Directory of Open Access Journals (Sweden)

    Napida Hinchiranan

    2011-11-01

    Full Text Available Waste tire pyrolysis oil has high potential to replace conventional fossil liquid fuels due to its high calorific heating value. However, the large amounts of sulfurous compounds in this oil hinders its application. Thus, the aim of this research was to investigate the possibility to apply the photo-assisted oxidation catalyzed by titanium dioxide (TiO2, Degussa P-25 to partially remove sulfurous compounds in the waste tire pyrolysis oil under milder reaction conditions without hydrogen consumption. A waste tire pyrolysis oil with 0.84% (w/w of sulfurous content containing suspended TiO2 was irradiated by using a high-pressure mercury lamp for 7 h. The oxidized sulfur compounds were then migrated into the solvent-extraction phase. A maximum % sulfur removal of 43.6% was achieved when 7 g/L of TiO2 was loaded into a 1/4 (v/v mixture of pyrolysis waste tire oil/acetonitrile at 50 °C in the presence of air. Chromatographic analysis confirmed that the photo-oxidized sulfurous compounds presented in the waste tire pyrolysis oil had higher polarity, which were readily dissolved and separated in distilled water. The properties of the photoxidized product were also reported and compared to those of crude oil.

  15. Effects of pore sizes and oxygen-containing functional groups on desulfurization activity of Fe/NAC prepared by ultrasonic-assisted impregnation

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Song [College of Architecture and Environment, Sichuan University, Chengdu 610065, Sichuan (China); Guo, Jia-Xiu, E-mail: guojiaxiu@scu.edu.cn [College of Architecture and Environment, Sichuan University, Chengdu 610065, Sichuan (China); National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065, Sichuan (China); Sichuan Provincial Environmental Protection Environmental Catalysis and Materials Engineering Technology Center, Chengdu 610065, Sichuan (China); Liu, Xiao-Li [National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065, Sichuan (China); Wang, Xue-Jiao [College of Architecture and Environment, Sichuan University, Chengdu 610065, Sichuan (China); Yin, Hua-Qiang [College of Architecture and Environment, Sichuan University, Chengdu 610065, Sichuan (China); National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065, Sichuan (China); Sichuan Provincial Environmental Protection Environmental Catalysis and Materials Engineering Technology Center, Chengdu 610065, Sichuan (China); Luo, De-Ming [National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065, Sichuan (China)

    2016-01-01

    Graphical abstract: - Highlights: • Fe/NAC-60 exhibits the best desulfurization activity. • Different oscillation time can change surface area and pore volume of catalysts. • Ultrasonic oscillation increases Fe dispersion on carrier and effective pores. • Pore sizes play a crucial role during the SO{sub 2} removal. - Abstract: A series of Fe-loaded activated carbons treated by HNO{sub 3} (Fe/NAC) were prepared by incipient impregnation method with or without ultrasonic assistance and characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy with energy disperse spectroscope (SEM-EDS), transmission electron microscopy (TEM) and N{sub 2} adsorption/desorption. The desulfurization activities were evaluated at a fixed bed reactor under a mixed gas simulated from flue gas. The results showed that desulfurization activity from excellent to poor is as follows: Fe/NAC-60 > Fe/NAC-80 > Fe/NAC-30 > Fe/NAC-15 > Fe/NAC-0 > Fe/NAC-100 > NAC. Fe/NAC-60 exhibits the best desulfurization activity and has breakthrough sulfur capacity of 319 mg/g and breakthrough time of 540 min. The introduction of ultrasonic oscillation does not change the form of Fe oxides on activated carbon but can change the dispersion and relative contents of Fe{sub 3}O{sub 4}. The types of oxygen-containing functional groups have no obvious change for all samples but the texture properties show some differences when they are oscillated for different times. The fresh Fe/NAC-60 has a surface area of 1045 m{sup 2}/g and total pore volume of 0.961 cm{sup 3}/g with micropore volume of 0.437 cm{sup 3}/g and is larger than Fe/NAC-0 (823 m{sup 2}/g, 0.733 and 0.342 cm{sup 3}/g). After desulfurization, surface area and pore volume of all samples decrease significantly, and those of the exhausted Fe/NAC-60 decrease to 233 m{sup 2}/g and 0.481 cm{sup 3}/g, indicating that some byproducts deposit on surface to cover pores. Pore size distribution

  16. Effects of pore sizes and oxygen-containing functional groups on desulfurization activity of Fe/NAC prepared by ultrasonic-assisted impregnation

    International Nuclear Information System (INIS)

    Shu, Song; Guo, Jia-Xiu; Liu, Xiao-Li; Wang, Xue-Jiao; Yin, Hua-Qiang; Luo, De-Ming

    2016-01-01

    Graphical abstract: - Highlights: • Fe/NAC-60 exhibits the best desulfurization activity. • Different oscillation time can change surface area and pore volume of catalysts. • Ultrasonic oscillation increases Fe dispersion on carrier and effective pores. • Pore sizes play a crucial role during the SO 2 removal. - Abstract: A series of Fe-loaded activated carbons treated by HNO 3 (Fe/NAC) were prepared by incipient impregnation method with or without ultrasonic assistance and characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy with energy disperse spectroscope (SEM-EDS), transmission electron microscopy (TEM) and N 2 adsorption/desorption. The desulfurization activities were evaluated at a fixed bed reactor under a mixed gas simulated from flue gas. The results showed that desulfurization activity from excellent to poor is as follows: Fe/NAC-60 > Fe/NAC-80 > Fe/NAC-30 > Fe/NAC-15 > Fe/NAC-0 > Fe/NAC-100 > NAC. Fe/NAC-60 exhibits the best desulfurization activity and has breakthrough sulfur capacity of 319 mg/g and breakthrough time of 540 min. The introduction of ultrasonic oscillation does not change the form of Fe oxides on activated carbon but can change the dispersion and relative contents of Fe 3 O 4 . The types of oxygen-containing functional groups have no obvious change for all samples but the texture properties show some differences when they are oscillated for different times. The fresh Fe/NAC-60 has a surface area of 1045 m 2 /g and total pore volume of 0.961 cm 3 /g with micropore volume of 0.437 cm 3 /g and is larger than Fe/NAC-0 (823 m 2 /g, 0.733 and 0.342 cm 3 /g). After desulfurization, surface area and pore volume of all samples decrease significantly, and those of the exhausted Fe/NAC-60 decrease to 233 m 2 /g and 0.481 cm 3 /g, indicating that some byproducts deposit on surface to cover pores. Pore size distribution influences SO 2 adsorption, and fresh Fe/NAC-60 has

  17. Desulfurization of organic sulfur from lignite by an electron transfer process

    Energy Technology Data Exchange (ETDEWEB)

    Demirbas, A. [Selcuk University, Konya (Turkey). Dept. for Chemical Engineering

    2006-10-15

    This study is an attempt to desulfurize organic sulfur from lignite samples with ferrocyanide ion as the electron transferring agent. Effect of temperature, particle size and concentration of ferrocyanide ion on desulfurization from the lignite samples has been investigated. The desulfurization process has been found to be continuous and gradually increases with increase of temperature from 298 to 368 K. The particle size has no significant impact on sulfur removal from the lignite samples. Particle size has no profound impact on the amount of sulfur removal. The desulfurization reaction has been found to be dependent on the concentration of potassium ferrocyanide. Gradual increase in the concentration of potassium ferrocyanide raised the magnitude of desulfurization, but at a higher concentration, the variation is not significant.

  18. Effects of surface acidities of MCM-41 modified with MoO{sub 3} on adsorptive desulfurization of gasoline

    Energy Technology Data Exchange (ETDEWEB)

    Shao Xinchao, E-mail: sxc86@yahoo.cn [Key Laboratory of Petrochemical Catalytic Science and Technology, Liaoning ShiHua University, Fushun 113001 (China); Zhang Xiaotong; Yu Wenguang; Wu Yuye [Key Laboratory of Petrochemical Catalytic Science and Technology, Liaoning ShiHua University, Fushun 113001 (China); Qin Yucai [Key Laboratory of Petrochemical Catalytic Science and Technology, Liaoning ShiHua University, Fushun 113001 (China); College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, Shandong 257061 (China); Sun Zhaolin [Key Laboratory of Petrochemical Catalytic Science and Technology, Liaoning ShiHua University, Fushun 113001 (China); School of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China); Song Lijuan, E-mail: lsong56@263.net [Key Laboratory of Petrochemical Catalytic Science and Technology, Liaoning ShiHua University, Fushun 113001 (China) and College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, Shandong 257061 (China)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer The MoO{sub 3}-MCM-41 samples prepared by spontaneous monolayer dispersion and impregnation with a different MoO{sub 3} filling have been studied. Black-Right-Pointing-Pointer The relative concentration of hydroxyl groups present on before and after containing MoO{sub 3} samples was monitored by in situ FTIR to speculate the bonding style of MoO{sub 3} and MCM-41. Black-Right-Pointing-Pointer The surface acidities of the MoO{sub 3}-MCM-41 adsorbents were investigated systematically and correlated with the desulfurization performance. - Abstract: A series of MCM-41 samples containing molybdenum oxide as active species in the mesoporous channels loaded by spontaneous monolayer dispersion (SMD) and impregnation (IM) have been prepared and characterized using XRD, N{sub 2} adsorption-desorption analysis, Fourier transform infrared spectroscopy (FTIR) and intelligent gravimetric analyzer (IGA). The relative number of hydroxy on the adsorbents was investigated by in situ FTIR. Surface acidities of the adsorbents were studied by infrared spectroscopy of adsorbed pyridine and correlated with reactivity for adsorptive desulfurization. The IGA technique was employed to investigate adsorption behavior of thiophene and benzene on the adsorbents at 303 K. It is shown that MoO{sub 3} can be highly dispersed up to 0.2 g g{sup -1} in the MCM-41 channels by the SMD strategy with the ordered mesoporous structure of the MoMM samples remaining intact. The ordered mesostructure of MCM-41 is, however, destroyed at higher MoO{sub 3} contents of 0.26 and 0.32 g g{sup -1} with particle sizes of 1.2 nm and 3.6 nm, respectively, observed. For the MoMI(0.2) sample prepared by the IM method, the aggregation of the MoO{sub 3} particles takes place with a particle size of 6.5 nm obtained. The results are also revealed that the dispersion extent of the MoO{sub 3} species is related to the abundant surface hydroxy of MCM-41. The host species and guest

  19. Effects of surface acidities of MCM-41 modified with MoO3 on adsorptive desulfurization of gasoline

    International Nuclear Information System (INIS)

    Shao Xinchao; Zhang Xiaotong; Yu Wenguang; Wu Yuye; Qin Yucai; Sun Zhaolin; Song Lijuan

    2012-01-01

    Highlights: ► The MoO 3 -MCM-41 samples prepared by spontaneous monolayer dispersion and impregnation with a different MoO 3 filling have been studied. ► The relative concentration of hydroxyl groups present on before and after containing MoO 3 samples was monitored by in situ FTIR to speculate the bonding style of MoO 3 and MCM-41. ► The surface acidities of the MoO 3 -MCM-41 adsorbents were investigated systematically and correlated with the desulfurization performance. - Abstract: A series of MCM-41 samples containing molybdenum oxide as active species in the mesoporous channels loaded by spontaneous monolayer dispersion (SMD) and impregnation (IM) have been prepared and characterized using XRD, N 2 adsorption–desorption analysis, Fourier transform infrared spectroscopy (FTIR) and intelligent gravimetric analyzer (IGA). The relative number of hydroxy on the adsorbents was investigated by in situ FTIR. Surface acidities of the adsorbents were studied by infrared spectroscopy of adsorbed pyridine and correlated with reactivity for adsorptive desulfurization. The IGA technique was employed to investigate adsorption behavior of thiophene and benzene on the adsorbents at 303 K. It is shown that MoO 3 can be highly dispersed up to 0.2 g g −1 in the MCM-41 channels by the SMD strategy with the ordered mesoporous structure of the MoMM samples remaining intact. The ordered mesostructure of MCM-41 is, however, destroyed at higher MoO 3 contents of 0.26 and 0.32 g g −1 with particle sizes of 1.2 nm and 3.6 nm, respectively, observed. For the MoMI(0.2) sample prepared by the IM method, the aggregation of the MoO 3 particles takes place with a particle size of 6.5 nm obtained. The results are also revealed that the dispersion extent of the MoO 3 species is related to the abundant surface hydroxy of MCM-41. The host species and guest species undergo solid-state reaction to form Si-O-Mo bonds in the mixtures which enhance both the Lewis acid and Brönsted acid of

  20. Novel ODS alloys for plant components subject to hot-gas impacts

    International Nuclear Information System (INIS)

    Lempenauer, K.; Arzt, E.

    1991-02-01

    Within the framework of the cooperative research project, novel surface layer systems have been developed for ODS, nickel-base alloys with an aluminium content of 10-12 weight %, intended for use at service temperatures between 1050 and 1100 C. They exhibit a good resistance to oxidation at high temperatures and low corrosion rates under conditions of sulfate-induced attack. The well-known chemical compatibility problems occurring at high service temperatures could be solved by an adequate variation of the activity gradients of important alloying constituents in the base material and the protective layer. Aluminium oxide layers prepared by pin-pointed pre-oxidation serve as diffusion-limiting layers between the base material and the oxidation-resistant surface layers and achieve a considerable reduction in interdiffusion processes between the surface layer and the base material. (orig.) [de

  1. Microstructure of HIPed and SPSed 9Cr-ODS steel and its effect on helium bubble formation

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Chenyang [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Material Science and Engineering, Northeastern University, Shenyang 110819, Liaoning (China); Department of Nuclear Engineering and Radiological Science, University of Michigan, Ann Arbor, MI, 48109 (United States); Lu, Zheng, E-mail: luz@atm.neu.edu.cn [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Material Science and Engineering, Northeastern University, Shenyang 110819, Liaoning (China); Xie, Rui; Liu, Chunming [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Material Science and Engineering, Northeastern University, Shenyang 110819, Liaoning (China); Wang, Lumin, E-mail: lmwang@umich.edu [Department of Nuclear Engineering and Radiological Science, University of Michigan, Ann Arbor, MI, 48109 (United States)

    2016-06-15

    Two 9Cr-ODS steels with the same nominal composition were consolidated by hot isostatic pressing (HIP, named COS-1) and spark plasma sintering (SPS, named COS-2). Helium ions were implanted into COS-1, COS-2 and non-ODS Eurofer 97 steels up at 673 K. Microstructures before and after helium ion implantations were carefully characterized. The results show a bimodal grain size distribution in COS-2 and a more uniform grain size distribution in COS-1. Nanoscale clusters of GP-zone type Y–Ti–O and Y{sub 2}Ti{sub 2}O{sub 7} pyrochlore as well as large spinel Mn(Ti)Cr{sub 2}O{sub 4} particles are all observed in the two ODS steels. The Y–Ti-enriched nano-oxides in COS-1 exhibit higher number density and smaller size than in COS-2. The Y–Ti-enriched nano-oxides in fine grains of COS-2 show higher number density and smaller size than that in coarse grains of COS-2. Nano-oxides effectively trap helium atoms and lead to the formation of high density and ultra-fine helium bubbles. - Highlights: • The microstructure changes of two ODS steels before and after helium ion implantation have been elucidated. • The mechanism of the microstructures of ODS steels under varied thermal mechanical processing paths have been explored. • The dependence of the size, density and distribution of helium bubbles on the specific microstructure features are explored.

  2. Present development status of EUROFER and ODS-EUROFER for application in blanket concepts

    Energy Technology Data Exchange (ETDEWEB)

    Lindau, R. [Forschungszentrum Karlsruhe, Institute for Materials Research I, P.O. Box 3640, 76021 Karlsruhe (Germany)]. E-mail: rainer.lindau@imf.fzk.de; Moeslang, A. [Forschungszentrum Karlsruhe, Institute for Materials Research I, P.O. Box 3640, 76021 Karlsruhe (Germany); Rieth, M. [Forschungszentrum Karlsruhe, Institute for Materials Research I, P.O. Box 3640, 76021 Karlsruhe (Germany); Klimiankou, M. [Forschungszentrum Karlsruhe, Institute for Materials Research I, P.O. Box 3640, 76021 Karlsruhe (Germany); Materna-Morris, E. [Forschungszentrum Karlsruhe, Institute for Materials Research I, P.O. Box 3640, 76021 Karlsruhe (Germany); Alamo, A. [CEA-Saclay, SRMA/SMPX, 91191 Gif-sur-Yvette Cedex (France); Tavassoli, A.-A. F. [CEA-Saclay, SRMA/SMPX, 91191 Gif-sur-Yvette Cedex (France); Cayron, C. [CEA-Grenoble, DRT/DTEN/SMP/LS2M, 17, rue des Martyrs, 38054 Grenoble Cedex 9 (France); Lancha, A.-M. [CIEMAT, Avda. Complutense no. 22, 28040 Madrid (Spain); Fernandez, P. [CIEMAT, Avda. Complutense no. 22, 28040 Madrid (Spain); Baluc, N. [CRPP-EPFL, 5232 Villigen PSI (Switzerland); Schaeublin, R. [CRPP-EPFL, 5232 Villigen PSI (Switzerland); Diegele, E. [EFDA Close Support Unit, Boltzmannstr. 2, 85748 Garching (Germany); Filacchioni, G. [ENEA CR Casaccia, Via Anguillarese 301, 00100 S. Maria di Galeria, Rome (Italy); Rensman, J.W. [NRG, MM and I, Westerduinweg 3, P.O. Box 25, 1755 ZG Petten (Netherlands); Schaaf, B. van der [NRG, MM and I, Westerduinweg 3, P.O. Box 25, 1755 ZG Petten (Netherlands); Lucon, E. [SCK-CEN, Boeretang 200, 2400 Mol (Belgium); Dietz, W. [MECS, Schoenenborner Weg 15, 51789 Lindlar (Germany)

    2005-11-15

    Within the European Union, the two major breeding blanket concepts presently being developed are the helium cooled pebble bed (HCPB), and the helium cooled lithium lead (HCLL) blankets. For both concepts, different conceptual designs are being discussed with temperature windows in the range 250-550 deg. C for conservative approaches based on reduced activation ferritic-martensitic (RAFM) steels, and in the range 250-650 deg. C for more advanced versions, taking into account oxide dispersion strengthened (ODS) steels. As a final result of a systematic development of RAFM-steels in Europe, the 9% CrWVTa alloy EUROFER was specified and produced in an industrial scale with a variety of product forms. A large characterisation program is being performed including irradiation in materials test reactors between 60 and 450 deg. C ({<=}15 dpa), and in a fast breeder reactor at 330 deg. C up to 30 dpa. EUROFER is resistant to high temperature ageing, and the existing creep-rupture data ({approx}30,000 h, 450-600 deg. C) indicate long-term stability and predictability. The ODS variant of EUROFER shows superior tensile and creep properties compared to EUROFER. Applying a new production route has diminished the problem of lower ductility and inferior impact properties. A reliable joining technique for ODS and RAFM steels employing diffusion welding was successfully developed.

  3. The influence of Cr content on the mechanical properties of ODS ferritic steels

    Science.gov (United States)

    Li, Shaofu; Zhou, Zhangjian; Jang, Jinsung; Wang, Man; Hu, Helong; Sun, Hongying; Zou, Lei; Zhang, Guangming; Zhang, Liwei

    2014-12-01

    The present investigation aimed at researching the mechanical properties of the oxide dispersion strengthened (ODS) ferritic steels with different Cr content, which were fabricated through a consolidation of mechanical alloyed (MA) powders of 0.35 wt.% nano Y2O3 dispersed Fe-12.0Cr-0.5Ti-1.0W (alloy A), Fe-16.0Cr-0.5Ti-1.0W (alloy B), and Fe-18.0Cr-0.5Ti-1.0W (alloy C) alloys (all in wt.%) by hot isostatic pressing (HIP) with 100 MPa pressure at 1150 °C for 3 h. The mechanical properties, including the tensile strength, hardness, and impact fracture toughness were tested by universal testers, while Young's modulus was determined by ultrasonic wave non-destructive tester. It was found that the relationship between Cr content and the strength of ODS ferritic steels was not a proportional relationship. However, too high a Cr content will cause the precipitation of Cr-enriched segregation phase, which is detrimental to the ductility of ODS ferritic steels.

  4. MICROSTRUCTURE AND MECHANICAL STRENGTH OF SURFACE ODS TREATED ZIRCALOY-4 SHEET USING LASER BEAM SCANNING

    Directory of Open Access Journals (Sweden)

    HYUN-GIL KIM

    2014-08-01

    Full Text Available The surface modification of engineering materials by laser beam scanning (LBS allows the improvement of properties in terms of reduced wear, increased corrosion resistance, and better strength. In this study, the laser beam scan method was applied to produce an oxide dispersion strengthened (ODS structure on a zirconium metal surface. A recrystallized Zircaloy-4 alloy sheet with a thickness of 2 mm, and Y2O3 particles of 10 μm were selected for ODS treatment using LBS. Through the LBS method, the Y2O3 particles were dispersed in the Zircaloy-4 sheet surface at a thickness of 0.4 mm, which was about 20% when compared to the initial sheet thickness. The mean size of the dispersive particles was 20 nm, and the yield strength of the ODS treated plate at 500°C was increased more than 65 % when compared to the initial state. This strength increase was caused by dispersive Y2O3 particles in the matrix and the martensite transformation of Zircaloy-4 matrix by the LBS.

  5. Ascorbic acid deficiency aggravates stress-induced gastric mucosal lesions in genetically scorbutic ODS rats.

    Science.gov (United States)

    Ohta, Y; Chiba, S; Imai, Y; Kamiya, Y; Arisawa, T; Kitagawa, A

    2006-12-01

    We examined whether ascorbic acid (AA) deficiency aggravates water immersion restraint stress (WIRS)-induced gastric mucosal lesions in genetically scorbutic ODS rats. ODS rats received scorbutic diet with either distilled water containing AA (1 g/l) or distilled water for 2 weeks. AA-deficient rats had 12% of gastric mucosal AA content in AA-sufficient rats. AA-deficient rats showed more severe gastric mucosal lesions than AA-sufficient rats at 1, 3 or 6 h after the onset of WIRS, although AA-deficient rats had a slight decrease in gastric mucosal AA content, while AA-sufficient rats had a large decrease in that content. AA-deficient rats had more decreased gastric mucosal nonprotein SH and vitamin E contents and increased gastric mucosal lipid peroxide content than AA-sufficient rats at 1, 3 or 6 h of WIRS. These results indicate that AA deficiency aggravates WIRS-induced gastric mucosal lesions in ODS rats by enhancing oxidative damage in the gastric mucosa.

  6. Adsorptive on-board desulfurization over multiple cycles for fuel-cell-based auxiliary power units operated by different types of fuels

    Science.gov (United States)

    Neubauer, Raphael; Weinlaender, Christof; Kienzl, Norbert; Bitschnau, Brigitte; Schroettner, Hartmuth; Hochenauer, Christoph

    2018-05-01

    On-board desulfurization is essential to operate fuel-cell-based auxiliary power units (APU) with commercial fuels. In this work, both (i) on-board desulfurization and (ii) on-board regeneration performance of Ag-Al2O3 adsorbent is investigated in a comprehensive manner. The herein investigated regeneration strategy uses hot APU off-gas as the regeneration medium and requires no additional reagents, tanks, nor heat exchangers and thus has remarkable advantages in comparison to state-of-the-art regeneration strategies. The results for (i) show high desulfurization performance of Ag-Al2O3 under all relevant operating conditions and specify the influence of individual operation parameters and the combination of them, which have not yet been quantified. The system integrated regeneration strategy (ii) shows excellent regeneration performance recovering 100% of the initial adsorption capacity for all investigated types of fuels and sulfur heterocycles. Even the adsorption capacity of the most challenging dibenzothiophene in terms of regeneration is restored to 100% over 14 cycles of operation. Subsequent material analyses proved the thermal and chemical stability of all relevant adsorption sites under APU off-gas conditions. To the best of our knowledge, this is the first time 100% regeneration after adsorption of dibenzothiophene is reported over 14 cycles of operation for thermal regeneration in oxidizing atmospheres.

  7. Production and performance of desulfurized rubber asphalt binder

    Directory of Open Access Journals (Sweden)

    Yanping Sheng

    2017-05-01

    Full Text Available Asphalt rubber binder typically exhibits disadvantages like segregation and high viscosity; however, this can be improved by the incorporation of desulfurized rubber powder. This study examined the swelling principle of desulfurized rubber asphalt (DRA. In addition, it evaluated the performance of DRA fabricated with various rubber powder contents under different shear conditions and development time. Superpave binders tests, including Brookfield viscosity, dynamic shear rheometer (DSR and bending beam rheometer (BBR tests, were applied on three control binders (i.e., neat, 20 mesh asphalt rubber binder, 40 mesh asphalt rubber binder and a DRA binder. Binder testing results indicated that rubber powder swelled into the base binder and resulted in enhanced stability. Optimum performance of the DRA binder was achieved by adding 20% (by weight of rubber powder into the base binder at shear rate, shear temperature, shear time and development time of 7000 r/min, 170 °C, 60 min and 45 min, respectively. Modified ranges of production conditions were also provided to widen the application of DRA in field construction. It appeared that DRA binder benefited from the recovered plasticity and viscosity of the rubber and consequently, exhibited superior performance over the neat and conventional asphalt rubber binders. Preliminary mixture evaluation was also conducted and the DRA binder was found to significantly improve the mixture resistance to permanent deformation and water damage. Overall, the DAR binder is encouraged to be used as a modified binder for flexible pavements. Keywords: Desulfurized rubber asphalt, Swelling model, Production process, Asphalt performance, Rubber asphalt

  8. Bench-Scale Demonstration of Hot-Gas Desulfurization Technology

    International Nuclear Information System (INIS)

    Portzer, Jeffrey W.; Gangwal, Santosh K.

    1997-01-01

    Prior to the current project, development of the DSRP was done in a laboratory setting, using synthetic gas mixtures to simulate the regeneration off-gas and coal gas feeds. The objective of the current work is to further the development of zinc titanate fluidized-bed desulfurization (ZTFBD) and the DSRP for hot-gas cleanup by testing with actual coal gas. The objectives of this project are to: (1) Develop and test an integrated, skid-mounted, bench-scale ZTFBD/DSRP reactor system with a slipstream of actual coal gas; (2) Test the bench-scale DSRP over an extended period with a slipstream of actual coal gas to quantify the degradation in performance, if any, caused by the trace contaminants present in coal gas (including heavy metals, chlorides, fluorides, and ammonia); (3) Expose the DSRP catalyst to actual coal gas for extended periods and then test its activity in a laboratory reactor to quantify the degradation in performance, if any, caused by static exposure to the trace contaminants in coal gas; (4) Design and fabricate a six-fold larger-scale DSRP reactor system for future slipstream testing; (5) Further develop the fluidized-bed DSRP to handle high concentrations (up to 14 percent) of SO 2 that are likely to be encountered when pure air is used for regeneration of desulfurization sorbents; and (6) Conduct extended field testing of the 6X DSRP reactor with actual coal gas and high concentrations of SO 2 . The accomplishment of the first three objectives--testing the DSRP with actual coal gas, integration with hot-gas desulfurization, and catalyst exposure testing--was described previously (Portzer and Gangwal, 1994, 1995; Portzer et al., 1996). This paper summarizes the results of previous work and describes the current activities and plans to accomplish the remaining objectives

  9. Crossed beam studies of O-+D2→OD-+D

    International Nuclear Information System (INIS)

    Johnson, S.G.; Kremer, L.N.; Metral, C.J.; Cross, R.J.

    1978-01-01

    Using the crossed-beam machine EVA we have measured the product angular and energy distributions of the reaction O - +D 2 →OD - +D in the relative energy range of 1.2-4.7 eV (5.7-23.1 eV LAB). Below 2.5 eV the product distribution is centered about the center of mass, indicating a long-lived complex. Above 2.5 eV the distribution slowly moves forward. Most of the available energy goes into internal energy of the products

  10. The rationalization of desulfurization by on-line analysis

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Y; Kohmura, S; Taketomi, H; Matsumura, S; Sasaki, Y

    1986-01-01

    Nippon Kokan uses the Takahax and Sulfiban processes for the desulfurization of coke oven gas. The authors outline the Sulfiban Process and describe a recently developed system for the on-line determination of H/sub 2/S in coke oven gas, and of CO/sub 2/ and monoethanolamine (MEA) in the wash oil. This new on-line analysis system has proved effective in rationalizing the Sulfiban Process via lower MEA production costs and decreased power consumption. The introduction of a computerized control system is now being studied. 7 figs., 4 tabs.

  11. Increasing draft capability for retrofit flue gas desulfurization systems

    International Nuclear Information System (INIS)

    Petersen, R.D.; Basel, B.E.; Mosier, R.J.

    1992-01-01

    The retrofit installation of flue gas desulfurization (FGD) systems results in significantly higher draft losses for existing generating stations. Consequently, the means for increasing draft capability must be included in many FGD retrofit projects. Consideration is given to several alternatives for increasing draft capability. Alternatives are developed for new induced draft (ID) fans to replace the existing ID fans and for new booster fans to supplement the existing ID fans. Both centrifugal and axial fans are evaluated, as are different means of fan volume control. Each alternative is evaluated on the basis of technical merit and economics. Presented are the development of fan alternatives and results of the technical and economic evaluations

  12. Fracture behaviour of the 14Cr ODS steel exposed to helium and liquid lead

    Energy Technology Data Exchange (ETDEWEB)

    Hojna, Anna, E-mail: Anna.Hojna@cvrez.cz [Centrum Vyzkumu Rez s.r.o., UJV Group, Rez 130, 250 68 Husinec (Czech Republic); Di Gabriele, Fosca [Centrum Vyzkumu Rez s.r.o., UJV Group, Rez 130, 250 68 Husinec (Czech Republic); Hadraba, Hynek; Husak, Roman; Kubena, Ivo [CEITEC IPM, Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Zizkova 22, 616 62 Brno (Czech Republic); Rozumova, Lucia; Bublikova, Petra; Kalivodova, Jana [Centrum Vyzkumu Rez s.r.o., UJV Group, Rez 130, 250 68 Husinec (Czech Republic); Matejicek, Jiri [Institute of Plasma Physics, Academy of Sciences of the Czech Republic, Za Slovankou 1782/3, 182 00 Praha (Czech Republic)

    2017-07-15

    This work describes the fracture behaviour of the 14Cr ODS steel produced by mechanical alloying process, after high temperature exposures. Small specimens were exposed to helium gas in a furnace at 720 °C for 500 h. Another set of specimens was exposed to flowing liquid lead in the COLONRI II loop at 650 °C for 1000 h. All specimens were tested for the impact and tensile behaviour. The impact test results are compared to other sets of specimens in the as received state and after isothermal annealing at 650 °C for 1000 h. The impact curves of the exposed materials showed positive shifts on the transition temperature. While the upper shelf value did not change in the Pb exposed ODS steel, it significantly increased in the He exposed one. The differences are discussed in terms of surface and subsurface microscopy observation. The embrittlement can be explained as the effect of a slight change in the grain boundary and size distribution combined with the depletion of sub-surface region from alloying elements forming oxide scale on the surface. - Highlights: •We compared the impact energy curves of as received, isothermally aged and He/Pb exposed ODS steel samples. •The highest transition temperature showed the ODS steel exposed to liquid Pb at 650 °C for 1000 h. •We observed the higher tendency of the He exposed samples to crack arrester delamination than the Pb exposed ones. •The crack arrested delamination induced apparent increase of impact energies.

  13. Preparation of Active Absorbent for Flue Gas Desulfurization From Coal Bottom Ash: Effect of Absorbent Preparation Variables

    Directory of Open Access Journals (Sweden)

    Chang Chin Li, Lee Keat Teong, Subhash Bhatia and Abdul Rahman Mohamed

    2012-08-01

    Full Text Available An active absorbent for flue gas desulfurization was prepared from coal bottom ash, calcium oxide (CaO and calcium sulfate by hydro-thermal process. The absorbent was examined for its micro-structural properties. The experiments conducted were based on Design Of Experiments (DOE according to 23 factorial design. The effect of various absorbent preparation variables such as ratio of CaO to bottom ash (A, hydration temperature (B and hydration period (C towards the BET (Brunauer-Emmett-Teller specific surface area of the absorbent were studied. At a CaO to bottom ash ratio = 2, hydration temperature = 200 ?C and hydration period = 10 hrs, absorbent with a surface area of 90.1 m2/g was obtained. Based on the analysis of the factorial design, it was concluded that factor A and C as well as the interaction of factors ABC and BC are the significant factors that effect the BET surface area of the absorbent. A linear mathematical model that describes the relation between the independent variables and interaction between variables towards the BET specific surface area of the absorbent was also developed. Analysis of variance (ANOVA showed that the model was significant at 1% level.Key Words: Absorbent, Bottom Ash, Design Of Experiments, Desulfurization, Surface Area.

  14. Removal of hazardous gaseous pollutants from industrial flue gases by a novel multi-stage fluidized bed desulfurizer.

    Science.gov (United States)

    Mohanty, C R; Adapala, Sivaji; Meikap, B C

    2009-06-15

    Sulfur dioxide and other sulfur compounds are generated as primary pollutants from the major industries such as sulfuric acid plants, cupper smelters, catalytic cracking units, etc. and cause acid rain. To remove the SO(2) from waste flue gas a three-stage counter-current multi-stage fluidized bed adsorber was developed as desulfurization equipment and operated in continuous bubbling fluidization regime for the two-phase system. This paper represents the desulfurization of gas mixtures by chemical sorption of sulfur dioxide on porous granular calcium oxide particles in the reactor at ambient temperature. The advantages of the multi-stage fluidized bed reactor are of high mass transfer and high gas-solid residence time that can enhance the removal of acid gas at low temperature by dry method. Experiments were carried out in the bubbling fluidization regime supported by visual observation. The effects of the operating parameters such as sorbent (lime) flow rate, superficial gas velocity, and the weir height on SO(2) removal efficiency in the multistage fluidized bed are reported. The results have indicated that the removal efficiency of the sulfur dioxide was found to be 65% at high solid flow rate (2.0 kg/h) corresponding to lower gas velocity (0.265 m/s), wier height of 70 mm and SO(2) concentration of 500 ppm at room temperature.

  15. The control of H2S in biogas using iron ores as in situ desulfurizers during anaerobic digestion process.

    Science.gov (United States)

    Zhou, Qiying; Jiang, Xia; Li, Xi; Jiang, Wenju

    2016-09-01

    In this study, five kinds of iron ores, limonite, hematite, manganese ore, magnetite and lava rock, were used as the in situ desulfurizers in the anaerobic digestion reactors to investigate their effects on controlling H2S in biogas. The results show that the addition of the five iron ores could significantly control the content of H2S in biogas, with the best performance for limonite. As limonite dosages increase (10-60 g/L), the contents of H2S in biogas were evidently decreased in the digesters with different initial sulfate concentrations (0-1000 mg/L). After the anaerobic digestion, the removed sulfur was mostly deposited on the surface of limonite. A possible mechanism of H2S control in biogas by limonite was proposed preliminarily, including adsorption, FeS precipitation, and Fe (III) oxidation. The results demonstrated that limonite was a promising in situ desulfurizer for controlling H2S in biogas with low cost and high efficiency.

  16. Factors Affecting Community Participation in O and OD Planning ...

    African Journals Online (AJOL)

    Factors Affecting Community Participation in O and OD Planning and ... great success at start but later dropped in number of cattle taken for dipping. ... and to establish the measures taken by the district leadership in addressing the problems.

  17. Mechanical behaviour of ferritic ODS steels - Temperature dependancy and history

    Czech Academy of Sciences Publication Activity Database

    Fournier, B.; Steckmeyer, A.; Rouffié, A.-L.; Malaplate, J.; Garnier, J.; Ratti, M.; Wident, P.; Ziolek, L.; Tournie, I.; Rabeau, V.; Gentzbittel, J.M.; Kruml, Tomáš; Kuběna, Ivo

    2012-01-01

    Roč. 430, 1-3 (2012), s. 142-149 ISSN 0022-3115 Institutional support: RVO:68081723 Keywords : ODS steels * fatigue * fracture mechanics Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 1.211, year: 2012

  18. Photodissociation of the OD radical at 226 and 243 nm

    International Nuclear Information System (INIS)

    Radenovic, Dragana C.; Roij, Andre J.A. van; Chestakov, Dmitri A.; Eppink, Andre T.J.B.; Meulen, J.J. ter; Parker, David H.; Loo, Mark P.J. van der; Groenenboom, Gerrit C.; Greenslade, Margaret E.; Lester, Marsha I.

    2003-01-01

    The photodissociation dynamics of state selected OD radicals has been examined at 243 and 226 nm using velocity map imaging to probe the angle-speed distributions of the D( 2 S) and O( 3 P 2 ) products. Both experiment and complementary first principle calculations demonstrate that photodissociation occurs by promotion of OD from high vibrational levels of the ground X 2 Π state to the repulsive 1 2 Σ - state

  19. OD Matrix Acquisition Based on Mobile Phone Positioning Data

    Directory of Open Access Journals (Sweden)

    Xiaoqing ZUO

    2014-06-01

    Full Text Available Dynamic OD matrix is basic data of traffic travel guidance, traffic control, traffic management and traffic planning, and reflects the basic needs of travelers on the traffic network. With the rising popularity of positioning technology and the communication technology and the generation of huge mobile phone users, the mining and use of mobile phone positioning data, can get more traffic intersections and import and export data. These data will be integrated into obtaining the regional OD matrix, which is bound to bring convenience. In this article, mobile phone positioning data used in the data acquisition of intelligent transportation system, research a kind of regional dynamic OD matrix acquisition method based on the mobile phone positioning data. The method based on purpose of transportation, using time series similarity classification algorithm based on piecewise linear representation of the corner point (CP-PLR, mapping each base station cell to traffic zone of different traffic characteristics, and through a series of mapping optimization of base station cell to traffic zone to realize city traffic zone division based on mobile phone traffic data, on the basis, adjacency matrix chosen as the physical data structure of OD matrix storage, the principle of obtaining regional dynamic OD matrix based on the mobile phone positioning data are expounded, and the algorithm of obtaining regional dynamic OD matrix based on mobile phone positioning data are designed and verified.

  20. Simulation of the BGO-OD experiment at ELSA

    Energy Technology Data Exchange (ETDEWEB)

    Johnstone, Russell [University of Bonn, Physikalisches Institut, Bonn (Germany); Collaboration: BGO-OD-Collaboration

    2011-07-01

    The goal of the BGO Open-Dipole (BGO-OD) project is the systematic investigation of the photoproduction of mesons off the nucleon. These processes are related to the structure of both the mesons and the baryons involved in reactions typical of low-energy hadronic physics. In order to fully understand and accurately interpret the results of the BGO-OD experiment it will be necessary to have a full detector and reaction simulation so that effects from detector resolution and acceptance can be accounted for in the final results. The simulation of the BGO-OD will be be undertaken with the Explora Virtual Monte-Carlo (VMC) software framework. This allows for one common user code to be implemented under Geant4, Geant3 and Fluka. The simulation software is also an analysis tool and such flexibility will be key to an efficient final analysis of the data from the BGO-OD experiment. Presented here are current status of the simulation software for the BGO-OD project and the relevant geometry of the BGO-OD, including the central BGO rugby ball detector with the dual-layer Multiwire Proportional Chambers (MWPCs) and the forward spectrometer, consisting of a large dipole magnet, tracking detectors and the Time-of-Flight walls. Simulation of the magnetic field will also be covered.

  1. Microstructure and phase transformations in the ODS alloys irradiated by swift heavy ions

    International Nuclear Information System (INIS)

    Zlotski, S.V.; Anishchik, V.M; Skuratov, V.A.; O’Connell, J.; Neethling, J.H.

    2015-01-01

    Microstructure of KP4 ODS alloy irradiated with 700 MeV bismuth ions at 300 K has been studied using high resolution transmission electron microscopy. No latent tracks have been observed in Y 4 Al 2 O 9 particles in KP4 irradiated with Bi ions. Small oxides (~ 5 nm) in KP4 alloy remain crystalline at Bi ion fluence 1.5*10 13 cm -2 , while subsurface regions in large (~ 20 nm) particles faced to the beam entrance became amorphous. (authors)

  2. The structural changes of Y2O3 in ferritic ODS alloys during milling

    International Nuclear Information System (INIS)

    Hilger, I.; Tegel, M.; Gorley, M.J.; Grant, P.S.; Weißgärber, T.; Kieback, B.

    2014-01-01

    Oxide dispersion strengthened (ODS) ferritic steels are usually fabricated via mechanical alloying and subsequent consolidation via hot extrusion or hot isostatic pressing. During the individual process steps, a complex evolution of the nanoparticle structure is taking place. Powders with different Y 2 O 3 contents were milled and examined by means of X-ray diffraction (XRD) and atom probe tomography (APT). It has been observed that the Y 2 O 3 is fragmented and becomes partially amorphous upon milling due to the grain refinement of Y 2 O 3 during the milling process. There was no compelling evidence for Y 2 O 3 dissociation and dissolution into the steel matrix

  3. Diffusion bonding of 9Cr ODS ferritic/martensitic steel with a phase transformation

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Sanghoon, E-mail: shnoh@kaeri.re.kr [Nuclear Materials Division, Korea Atomic Energy Research Institute, Yuseong-gu, Daejeon (Korea, Republic of); Kimura, Akihiko [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto (Japan); Kim, Tae Kyu [Nuclear Materials Division, Korea Atomic Energy Research Institute, Yuseong-gu, Daejeon (Korea, Republic of)

    2014-10-15

    Highlights: • Diffusion bonding was employed to join 9Cr oxide dispersion strengthened ferritic/martensitic steel under uniaxial hydrostatic pressure, and the microstructure and tensile properties of the joints were investigated. • ODS steel was successfully diffusion bonded at an austenization temperature to migrate a residual diffusion bonding interface. • The tensile properties of the joint region were comparable with that of the base metal with a ductile fracture occurred far from the bonding interface. • It is considered that diffusion bonding with a phase transformation can be a very useful joining method for fabricating components in next-generation nuclear systems using 9Cr ODS ferritic/martensitic steel. - Abstract: Diffusion bonding was employed to join oxide-dispersion-strengthened ferritic/martensitic steel under uniaxial hydrostatic pressure using a high vacuum hot press, and the microstructure and tensile properties of the joints were investigated. 9Cr oxide dispersion strengthened (ODS) steel was successfully diffusion bonded at 1150 °C for 1 h to migrate a residual bonding interface. Following heat treatment, including normalising at 1050 °C and tempering at 800 °C for 1 h, comparable results without inclusions or micro-voids at the bonding interface, or degradation in the base metal were achieved. Transmission electron microscopy (TEM) observation revealed that the nano-oxide particles in the bonding region were uniformly distributed in the matrix. At room temperature, the joint had nearly the same tensile properties with that of the base metal. The tensile strength of the joint region at elevated temperatures was comparable with that of the base metal. The total elongation of the joint region decreased slightly, but reached 80% of the base metal at 700 °C, and a ductile fracture occurred far from the bonding interface. Therefore, it is considered that diffusion bonding with a phase transformation can be a very useful joining method for

  4. Positron and nanoindentation study of helium implanted high chromium ODS steels

    Science.gov (United States)

    Veternikova, Jana Simeg; Fides, Martin; Degmova, Jarmila; Sojak, Stanislav; Petriska, Martin; Slugen, Vladimir

    2017-12-01

    Three oxide dispersion strengthened (ODS) steels with different chromium content (MA 956, MA 957 and ODM 751) were studied as candidate materials for new nuclear reactors in term of their radiation stability. The radiation damage was experimentally simulated by helium ion implantation with energy of ions up to 500 keV. The study was focused on surface and sub-surface structural change due to the ion implantation observed by mostly non-destructive techniques: positron annihilation lifetime spectroscopy and nanoindentation. The applied techniques demonstrated the best radiation stability of the steel ODM 751. Blistering effect occurred due to high implantation dose (mostly in MA 956) was studied in details.

  5. A Comparative Study of Welded ODS Cladding materials for AFCI/GNEP Applications

    International Nuclear Information System (INIS)

    Charit, Indrajit; Frary, Megan; Butt, Darryl; Murty, K.L.; Zirker, Larry; Cole, James; Meyer, Mitchell; Mishra, Rajiv S.; Woltz, Mark

    2011-01-01

    This research project involved working on the pressure resistance welding of oxide dispersion strengthened (ODS) alloys which will have a large role to play in advanced nuclear reactors. The project also demonstrated the research collaboration between four universities and one nation laboratory (Idaho National Laboratory) with participation from an industry for developing for ODS alloys. These alloys contain a high number density of very fine oxide particles that can impart high temperature strength and radiation damage resistance suitable for in-core applications in advanced reactors. The conventional fusion welding techniques tend to produce porosity-laden microstructure in the weld region and lead to the agglomeration and non-uniform distribution of the needed oxide particles. That is why two solid state welding methods - pressure resistance welding (PRW) and friction stir welding (FSW) - were chosen to be evaluated in this project. The proposal is expected to support the development of Advanced Burner Reactors (ABR) under the GNEP program (now incorporated in Fuel Cycle R and D program). The outcomes of the concluded research include training of graduate and undergraduate students and get them interested in nuclear related research.

  6. Development of ODS ferritic-martensitic steels for application to high temperature and irradiation environment

    International Nuclear Information System (INIS)

    Lambard, V.

    2000-01-01

    Iron oxide dispersion strengthened alloys are candidate for nuclear fuel cladding. Therefore, it is crucial to control their microstructure in order to optimise their mechanical properties at temperatures up to 700 deg C. The industrial candidates, ODS ferritic alloys, present an anisotropic microstructure which induces a weakening of mechanical properties in transversal direction as well as the precipitation of brittle phases under thermal aging and irradiation. For this purpose, we tried to develop a material with isotropic properties. We studied several 9Cr-1Mo ferritic/martensitic alloys, strengthened or not by oxide dispersion. The mechanical alloying was performed by attribution and powders were consolidated by hot extrusion. In this work, different metallurgical characterisation techniques and modelling were used to optimise a new martensitic ODS alloy. Microstructural and chemical characterization of matrix has been done. The effect of austenitizing and isochronal tempering treatments on microstructure and hardness has been studied. Oxide distribution, size and chemical composition have been studied before and after high temperature thermal treatment. The study of phase transformation upon heating has permitted the extrapolation to the equilibrium temperature formation of austenite. Phase transformation diagrams upon cooling have been determined and the transformation kinetics have been linked to austenite grain size by a simple relation. Fine grain size is unfavourable for the targeted application, so a particular thermal treatment inducing a coarser grain structure has been developed. Finally, tensile properties have been determined for the different microstructures. (author)

  7. Desulfurization Activated Phosphorothioate DNAzyme for the Detection of Thallium.

    Science.gov (United States)

    Huang, Po-Jung Jimmy; Vazin, Mahsa; Liu, Juewen

    2015-10-20

    Thallium (Tl) is a highly toxic heavy metal situated between mercury and lead in the periodic table. While its neighbors have been thoroughly studied for DNA-based sensing, little is known about thallium detection. In this work, in vitro selection of RNA-cleaving DNAzymes is carried out using Tl(3+) as the target metal cofactor. Both normal DNA and phosphorothioate (PS)-modified DNA are tested for this purpose. While no Tl(3+)-dependent DNAzymes are obtained, a DNA oligonucleotide containing a single PS-modified RNA nucleotide is found to cleave by ∼7% by Tl(3+) at the RNA position. The remaining 93% are desulfurized. By hybridization of this PS-modified oligonucleotide with the Tm7 DNAzyme, the cleavage yield increases to ∼40% in the presence of Tl(3+) and Er(3+). Tm7 is an Er(3+)-dependent RNA-cleaving DNAzyme. It cleaves only the normal substrate but is completely inactive using the PS-modified substrate. Tl(3+) desulfurizes the PS substrate to the normal substrate to be cleaved by Tm7 and Er(3+). This system is engineered into a catalytic beacon for Tl(3+) with a detection limit of 1.5 nM, which is below its maximal contamination limit defined by the U.S. Environmental Protection Agency (10 nM).

  8. Structural characterization of degradation of ODS composite using SEM and XRM techniques

    Directory of Open Access Journals (Sweden)

    Oladayo OLANIRAN

    2017-07-01

    Full Text Available The structural characteristics and mechanisms of corrosion and wear of oxide dispersion strengthened stainless steel composite were investigated. Insitu synchrotron x-ray tomography was used as experimental technique for degradation analysis from the corrosion and tribology studies. Corrosion study was carried out using potential dynamic techniques while the tribology experiments were conducted using a tribometer with ball on disc method. The x-ray micro tomography data gave chronological description of crack initiation and propagation in 3D and revealed that pitting did not result from the oxide inclusion. The results also revealed the surface imaging capacity of SEM and XRM’s capability for imaging internal structures. Taber index measurement was used as a complimenting tool for tribology measurements. Tribological behaviour of the sinter Oxide Dispersion Strengthened (ODS steel composite depends on both the composition of the composite and the loading system.

  9. Preparation of MoO2/g-C3N4 composites with a high surface area and its application in deep desulfurization from model oil

    Science.gov (United States)

    Hou, Liang-pei; Zhao, Rong-xiang; Li, Xiu-ping; Gao, Xiao-han

    2018-03-01

    A series of catalysts of composition X-MoO2/g-C3N4 (X = 0, 0.5, 1, 3, 5 wt.%) were successfully synthesized by calcination of a mixture of (NH4)6Mo7O24·4H2O and g-C3N4. Oxidative desulfurization experiments were conducted using X-MoO2/g-C3N4 as a catalyst, H2O2 as an oxidant, and ionic liquids (ILs) as extraction agents. Catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared (FT-IR), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), and Brunauer-Emmett-Teller analysis (BET). Characterization results suggested that MoO2 was present in the catalyst and its crystallinity improved with increased Mo-loading. The catalysts had a larger specific surface area due to the presence of MoO2 dispersed on g-C3N4. Experimental results showed that 3%-MoO2/g-C3N4 had the highest catalytic activity among all the catalysts tested. A desulfurization rate of 96.0% was achieved under optimal conditions. Through gas chromatography-mass spectrometry (GC-MS) analysis, it was shown that dibenzothoiphene sulfone was the sole product of the oxidation desulfurization reaction. An apparent activation energy of 61.1 kJ/mol was estimated based on Arrhenius equation. The activity of 3%-MoO2/g-C3N4 slightly decreased after six runs. A possible mechanism for the reaction has been proposed.

  10. Ultra-Deep Adsorptive Desulfurization of Light-Irradiated Diesel Fuel over Supported TiO2-CeO2 Adsorbents

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Jing; Wang, Xiaoxing; Chen, Yongsheng; Fujii, Mamoru; Song, Chunshan [SCUT-China; (Penn)

    2014-02-13

    This study investigates ultra-deep adsorptive desulfurization (ADS) from light-irradiated diesel fuel over supported TiO2–CeO2 adsorbents. A 30-fold higher desulfurization capacity of 95 mL of fuel per gram of adsorbent (mL-F/g-sorb) or 1.143 mg of sulfur per gram of adsorbent (mg-S/g-sorb) was achieved from light-irradiated fuel over the original low-sulfur fuel containing about 15 ppm by weight (ppmw) of sulfur. The sulfur species on spent TiO2–CeO2/MCM-48 adsorbent was identified by sulfur K-edge XANES as sulfones and the adsorption selectivity to different compounds tested in a model fuel decreases in the order of indole > dibenzothiophenesulfone → dibenzothiophene > 4-methyldibenzothiophene > benzothiophene > 4,6-dimethyldibenzothiophene > phenanthrene > 2-methylnaphthalene ~ fluorene > naphthalene. The results suggest that during ADS of light-irradiated fuel, the original sulfur species were chemically transformed to sulfones, resulting in the significant increase in desulfurization capacity. For different supports for TiO2–CeO2 oxides, the ADS capacity increases with a decrease in the point of zero charge (PZC) value; for silica-supported TiO2–CeO2 oxides (the lowest PZC value of 2–4) with different surface areas, the ADS capacity increases monotonically with increasing surface area. The supported TiO2–CeO2/MCM-48 adsorbent can be regenerated using oxidative air treatment. The present study provides an attractive new path to achieve ultraclean fuel more effectively.

  11. Energy-filtered TEM imaging and EELS study of ODS particles and argon-filled cavities in ferritic-martensitic steels.

    Science.gov (United States)

    Klimiankou, M; Lindau, R; Möslang, A

    2005-01-01

    Oxide-dispersion-strengthened (ODS) ferritic-martensitic steels with yttrium oxide (Y(2)O(3)) have been produced by mechanical alloying and hot isostatic pressing for use as advanced material in fusion power reactors. Argon gas, usually widely used as inert gas during mechanical alloying, was surprisingly detected in the nanodispersion-strengthened materials. Energy-filtered transmission electron microscopy (EFTEM) and electron energy loss spectroscopy (EELS) led to the following results: (i) chemical composition of ODS particles, (ii) voids with typical diameters of 1-6 nm are formed in the matrix, (iii) these voids are filled with Ar gas, and (iv) the high-density nanosized ODS particles serve as trapping centers for the Ar bubbles. The Ar L(3,2) energy loss edge at 245 eV as well as the absorption features of the ODS particle elements were identified in the EELS spectrum. The energy resolution in the EEL spectrum of about 1.0 eV allows to identify the electronic structure of the ODS particles.

  12. Microbial reduction of SO{sub 2} and NO{sub x} as a means of by-product recovery/disposal from regenerable processes for the desulfurization of flue gas. Technical progress report, March 11, 1993--June 11, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Sublette, K.L.

    1993-11-01

    There are two basic approaches to addressing the problem of SO{sub 2} and NO{sub x} emissions: (1) desulfurize (and denitrogenate) the feedstock prior to or during combustion; or (2) scrub the resultant SO{sub 2} and oxides of nitrogen from the boiler flue gases. The flue gas processing alternative has been addressed in this project via microbial reduction of SO{sub 2} and NO{sub x} by sulfate-reducing bacteria

  13. Resistance Upset Welding of ODS Steel Fuel Claddings—Evaluation of a Process Parameter Range Based on Metallurgical Observations

    Directory of Open Access Journals (Sweden)

    Fabien Corpace

    2017-08-01

    Full Text Available Resistance upset welding is successfully applied to Oxide Dispersion Strengthened (ODS steel fuel cladding. Due to the strong correlation between the mechanical properties and the microstructure of the ODS steel, this study focuses on the consequences of the welding process on the metallurgical state of the PM2000 ODS steel. A range of process parameters is identified to achieve operative welding. Characterizations of the microstructure are correlated to measurements recorded during the welding process. The thinness of the clad is responsible for a thermal unbalance, leading to a higher temperature reached. Its deformation is important and may lead to a lack of joining between the faying surfaces located on the outer part of the join which can be avoided by increasing the dissipated energy or by limiting the clad stick-out. The deformation and the temperature reached trigger a recrystallization phenomenon in the welded area, usually combined with a modification of the yttrium dispersion, i.e., oxide dispersion, which can damage the long-life resistance of the fuel cladding. The process parameters are optimized to limit the deformation of the clad, preventing the compactness defect and the modification of the nanoscale oxide dispersion.

  14. [Development and integration of the Oncological Documentation System ODS].

    Science.gov (United States)

    Raab, G; van Den Bergh, M

    2001-08-01

    To simplify clinical routine and to improve medical quality without exceeding the existing resources. Intensifying communication and cooperation between all institutions of patients' health care. The huge amount of documentation work of physicians can no longer be done without modern tools of paperless data processing. The development of ODS was a tight cooperation between physician and technician which resulted in a mutual understanding and led to a high level of user convenience. - At present all cases of gynecology, especially gynecologic oncology can be documented and processed by ODS. Users easily will adopt the system as data entry within different program areas follows the same rules. In addition users can choose between an individual input of data and assistants guiding them through highly specific areas of documentation. ODS is a modern, modular structured and very fast multiuser database environment for in- and outpatient documentation. It automatically generates a lot of reports for clinical day to day business. Statistical routines will help the user reflecting his work and its quality. Documentation of clinical trials according to the GCP guidelines can be done by ODS using the internet or offline datasharing. As ODS is the synthesis of a computer based patient administration system and an oncological documentation database, it represents the basis for the construction of the electronical patient chart as well as the digital documentation of clinical trials. The introduction of this new technology to physicians and nurses has to be done slowly and carefully, in order to increase motivation and to improve the results.

  15. Experimental study of desulfurization of Zhong Liang Shau high sulfur coal by flotation

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Z.; Huang, B.; Cao, J. [China University of Mining and Technology (China). Beijing Graduate School

    1994-12-01

    Emission of large amount of SO{sub 2} from combustion of high sulfur coal causes serious environmental pollution. Pre-combustion desulfurization of high sulfur coal has become a necessity. This paper reports test results of fine coal desulfurization with different flotation technology and the effect of pyrite depressant. Test work showed that when the coal sample from Zhong Liang Shau was processed with a Free Jet Flotation Column its pyritic sulfur content was reduced from 3.08% to 0.84%, with 72.22% recovery of combustible matter in clean coal. The concept of Desulfurization Efficiency Index E{sub ds} for comprehensive evaluation of desulfurization process is proposed, which is defined as the product of the ratio of sulfur content reduction of clean coal and the recovery of combustible matters. 6 refs., 4 figs., 3 tabs.

  16. Fundamental studies of desulfurization processes: reaction of methanethiol on ZnO and Cs/ZnO

    Science.gov (United States)

    Dvorak, Joseph; Jirsak, Tomas; Rodriguez, José A.

    2001-05-01

    The reaction of methanethiol on ZnO and Cs promoted ZnO surfaces has been studied with synchrotron based photoemission and thermal desorption spectroscopy. On ZnO, methanethiol undergoes selective reaction to produce carbon monoxide (37-58%), methane (23-38%), formaldehyde (12-15%), ethane (1-11%), and a mixture of ethylene and acetylene (3-13%). At low temperatures (cleavage occurs to yield methyl intermediate and atomic S. Carbon is removed from the surface as gaseous products above 500 K, and atomic sulfur remains bound to the zinc sites of the surface. Submonolayer amounts of cesium do not have a significant promotional effect on C-S bond cleavage, whereas Cs multilayers are found to significantly lower the activation barrier for C-S bond cleavage. This study illustrates the chemistry associated with the desulfurization of thiols on a catalytically relevant oxide surface.

  17. Integrated photooxidative extractive deep desulfurization using metal doped TiO2 and eutectic based ionic liquid

    Science.gov (United States)

    Zaid, Hayyiratul Fatimah Mohd; Kait, Chong Fai; Mutalib, Mohamed Ibrahim Abdul

    2016-11-01

    A series of metal doped TiO2 namely Fe/TiO2, Cu/TiO2 and Cu-Fe/TiO2 were synthesized and characterized, to be used as a photocatalyst in the integrated photooxidative extractive deep desulfurization for model oil (dodecane) and diesel fuel. The order of the photocatalytic activity was Cu-Fe/TiO2 followed by Cu/TiO2 and then Fe/TiO2. Cu-Fe/TiO2 was an effective photocatalyst for sulfur conversion at ambient atmospheric pressure. Hydrogen peroxide was used as the source of oxidant and eutectic-based ionic liquid as the extractant. Sulfur conversion in model oil reached 100%. Removal of sulfur from model oil was done by two times extraction with a removal of 97.06% in the first run and 2.94% in the second run.

  18. Oxidative degradation stability and hydrogen sulfide removal performance of dual-ligand iron chelate of Fe-EDTA/CA.

    Science.gov (United States)

    Miao, Xinmei; Ma, Yiwen; Chen, Zezhi; Gong, Huijuan

    2017-09-05

    Catalytic oxidation desulfurization using chelated iron catalyst is an effective method to remove H 2 S from various gas streams including biogas. However, the ligand of ethylenediaminetetraacetic acid (EDTA), which is usually adopted to prepare chelated iron catalyst, is liable to be oxidative degraded, and leads to the loss of desulfurization performance. In order to improve the degradation stability of the iron chelate, a series of iron chelates composed of two ligands including citric acid (CA) and EDTA were prepared and the oxidative degradation stability as well as desulfurization performance of these chelated iron catalysts were studied. Results show that the iron chelate of Fe-CA is more stable than Fe-EDTA, while for the desulfurization performance, the situation is converse. For the dual-ligand iron chelates of Fe-EDTA/CA, with the increase of mol ratio of CA to EDTA in the iron chelate solution, the oxidative degradation stability increased while the desulfurization performance decreased. The results of this work showed that Fe-EDTA/CA with a mol ratio of CA:EDTA = 1:1 presents a relative high oxidative degradation stability and an acceptable desulfurization performance with over 90% of H 2 S removal efficiency.

  19. Research improvement in Zn-based sorbent for hot gas desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    X. Bu; Y. Ying; C. Zhang; W. Peng [China Coal Research Institute (CCRI), Beijing (China). Beijing Research Institute of Coal Chemistry

    2005-07-01

    Two Zn-based sorbents, named as L-991 and L-992, used for hot gas desulfurization were developed. The L-992, which was prepared by changing the Zn/Ti ratio and adding a certain proportion of Cu and Mn metal oxide, acquired better performance than L-991. The suitable desulfurisation temperature was 600-700{sup o}C for the L-991 and 600-800{sup o}C for the L-992. The sulfur capacity was about 16 g/100 g and 19-21 g/100 g of L-991 and L-992 respectively. After 17 multi-cycles sulfidation/regeneration tests, the sulfur capacity of the L-991 decreased greatly, while that of the L-992 still remained at 17 g/100 g. Both the sorbents showed orderly crystalline orientation and the particle size did not change. Sulfidation and regeneration tests were done both on lab micro-fixed bed reactor and SMOVEN equipment. During the continuous tests, the H{sub 2}S concentration can be reduced from about 10 g/m{sup 3} to less than 20 mg/m{sup 3}, the H{sub 2}S removal efficiency being {gt} 99%. 14 refs., 9 figs., 2 tabs.

  20. A polyoxometalate-encapsulating cationic metal-organic framework as a heterogeneous catalyst for desulfurization.

    Science.gov (United States)

    Hao, Xiu-Li; Ma, Yuan-Yuan; Zang, Hong-Ying; Wang, Yong-Hui; Li, Yang-Guang; Wang, En-Bo

    2015-02-23

    A new cationic triazole-based metal-organic framework encapsulating Keggin-type polyoxometalates, with the molecular formula [Co(BBPTZ)3][HPMo12O40]⋅24 H2O [compound 1; BBPTZ = 4,4'-bis(1,2,4-triazol-1-ylmethyl)biphenyl] is hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, powder X-ray diffraction, and single-crystal X-ray diffraction. The structure of compound 1 contains a non-interpenetrated 3D CdSO4 (cds)-type framework with two types of channels that are interconnected with each other; straight channels that are occupied by the Keggin-type POM anions, and wavelike channels that contain lattice water molecules. The catalytic activity of compound 1 in the oxidative desulfurization reaction indicates that it is not only an effective and size-selective heterogeneous catalyst, but it also exhibits distinct structural stability in the catalytic reaction system. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Simulation of the operation of an industrial wet flue gas desulfurization system

    International Nuclear Information System (INIS)

    Kallinikos, L.E.; Farsari, E.I.; Spartinos, D.N.; Papayannakos, N.G.

    2010-01-01

    In this work the simulation of a wet flue gas desulfurization (FGD) unit with spray tower of a power plant is presented, aiming at an efficient follow-up and the optimization of the FGD system operation. The dynamic model developed to simulate the performance of the system has been validated with operation data collected over a long period of time. All the partaking physical and chemical processes like the limestone dissolution, the crystallization of calcium sulfite and gypsum and the oxidation of sulfite ions have been taken into account for the development of the simulation model while the gas absorption by the liquid droplets was based on the two-film theory. The effect of the mean diameter of the slurry droplets on the performance of the system was examined, as it was used as an index factor of the normal operation of the system. The operation limits of the system were investigated on the basis of the model developed. It is concluded that the model is capable of simulating the system for significantly different SO 2 loads and that the absorption rate of SO 2 is strongly affected by the liquid dispersion in the tower. (author)

  2. Reactive-inspired ball-milling synthesis of an ODS steel: study of the influence of ball-milling and annealing

    International Nuclear Information System (INIS)

    Brocq, M.

    2010-10-01

    In the context of the development of new ODS (Oxide Dispersion Strengthened) steels as core materials in future nuclear reactors, we investigated a new process inspired by reactive ball-milling which consists in using YFe 3 andFe 2 O 3 as starting reactants instead of Y 2 O 3 to produce a dispersion of nano-oxides in a steel matrix and the influence of synthesis conditions on the nano-oxide characteristics were studied. For that aim, ODS steels were prepared by ball-milling and then annealed. Multi-scale characterizations were performed after each synthesis step, using notably atom probe tomography and small angle neutron scattering. The process inspired by reactive ball-milling was shown to be efficient for ODS steel synthesis, but it does not modify the nano-oxide characteristics as compared to those of oxides directly incorporated in the matrix by ball-milling. Broadly speaking, the nature of the starting oxygen bearing reactants has no influence on nano-oxide formation. Moreover, we showed that the nucleation of nano-oxides nucleation can start during milling and continues during annealing with a very fast kinetic. The final characteristics of nano-oxides formed in this way can be monitored through ball-milling parameters (intensity, temperature and atmosphere) and annealing parameters (duration and temperature). (author)

  3. A Comparative Study of Welded ODS Cladding materials for AFCI/GNEP Applications

    Energy Technology Data Exchange (ETDEWEB)

    Indrajit Charit; Megan Frary; Darryl Butt; K.L. Murty; Larry Zirker; James Cole; Mitchell Meyer; Rajiv S. Mishra; Mark Woltz

    2011-03-31

    This research project involved working on the pressure resistance welding of oxide dispersion strengthened (ODS) alloys which will have a large role to play in advanced nuclear reactors. The project also demonstrated the research collaboration between four universities and one nation laboratory (Idaho National Laboratory) with participation from an industry for developing for ODS alloys. These alloys contain a high number density of very fine oxide particles that can impart high temperature strength and radiation damage resistance suitable for in-core applications in advanced reactors. The conventional fusion welding techniques tend to produce porosity-laden microstructure in the weld region and lead to the agglomeration and non-uniform distribution of the neededoxide particles. That is why two solid state welding methods - pressure resistance welding (PRW) and friction stir welding (FSW) - were chosen to be evaluated in this project. The proposal is expected to support the development of Advanced Burner Reactors (ABR) under the GNEP program (now incorporated in Fuel Cycle R&D program). The outcomes of the concluded research include training of graduate and undergraduate students and get them interested in nuclear related research.

  4. Effect of microstructure on low cycle fatigue properties of ODS steels

    Energy Technology Data Exchange (ETDEWEB)

    Kubena, Ivo, E-mail: kubena@ipm.cz [IPM, Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Zizkova 22, Brno (Czech Republic); Fournier, Benjamin [CEA/DEN/DANS/DMN/SRMA, Bat. 453, 91191 Gif-sur-Yvette Cedex (France); Kruml, Tomas [CEITEC IPM, Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Zizkova 22, Brno (Czech Republic)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Three various ODS steels are studied and compared. Black-Right-Pointing-Pointer Low cycle fatigue data at RT, 650 Degree-Sign C and 750 Degree-Sign C are given. Black-Right-Pointing-Pointer Microstructural characterization. Black-Right-Pointing-Pointer Detailed discussion of strengthening mechanisms. - Abstract: Low cycle fatigue properties at room temperature, 650 Degree-Sign C and 750 Degree-Sign C of three high chromium steels (9%Cr ferritic-martensitic and two 14%Cr ferritic steels) strengthened by oxide dispersion were studied and compared. Cyclic softening/hardening curves, cyclic deformation curves, S-N curves and Coffin-Manson curves are presented together with microstructural observations. Differences in cyclic response, stress level and fatigue life are attributed to differences in the matrix microstructure. The oxide particles stabilize the cyclic response, even if cyclic softening is detected for some experimental conditions. The strength of these steels is discussed in terms of strengthening mechanisms such as grain size effect, particle-dislocations interaction and dislocation density. Comparing three different ODS steels offers an opportunity to tests the contribution of individual mechanisms to the cyclic strength. The reduction of fatigue life in one of the ferritic steels is explained by the presence of large grains, facilitating the fatigue crack nucleation and the early growth.

  5. Analysis of high temperature deformation mechanism in ODS EUROFER97 alloy

    Science.gov (United States)

    Ramar, A.; Spätig, P.; Schäublin, R.

    2008-12-01

    Oxide dispersion in tempered martensitic EUROFER97 steel is an efficient approach to improve its strength. The oxide dispersion strengthened (ODS) EUROFER97 steel shows a good strength up to 600 °C, but degrades rapidly beyond that temperature. To understand the origin in the microstructure of this drop in strength in situ heating experiment in TEM was performed from room temperature to 1000 °C. Upon heating neither microstructure changes nor dislocation movement are observed up to 600 °C. Movement of dislocations are observed above 680 °C. Phase transformation to austenite starts at 840 °C. Yttria particles remain stable up to 1000 °C. Changes in mechanical properties thus do not relate to changes in yttria dispersion. It is attempted to relate these observations to the thermal activation parameters measured by the technique of conventional strain rate experiment, which allow to identify at a mesoscopic scale the microstructural mechanisms responsible for the degradation of ODS steel at high temperatures.

  6. Simultaneous desulfurization and denitrification of flue gas by electron beam

    International Nuclear Information System (INIS)

    Baumann, W.; Jordan, S.; Maetzing, H.; Paur, H.R.; Schikarski, W.; Wiens, H.

    1987-05-01

    The simultaneous desulfurization and denitrification by the irradiation with 300 keV electrons in the presence of stoichiometric amounts of ammonia yields removal efficiencies of more than 90%. NO X -removal efficiencies depend on the absorbed dose, NO X -concentration and NH 3 -stoichiometry. SO 2 -removal proceeds by thermal and radiation induced mechanisms. The efficiency of the SO 2 -removal process is highest for low temperatures and high NH 3 -stoichiometries. By recycling of scrubbed gas into the reaction chamber (multiple irradiation) the efficiency of the process is increased by 50%. The product aerosol has mass median diameters of 2 and NO x removals in the absence of NH 3 are predicted with reasonable accuracy by the computer model. In the presence of NH 3 experimental data show higher SO 2 removal efficiencies than calculated. This is probably due to additional heterogeneous reactions on particles, which are not covered by the computer model. With 119 figs., 86 refs [de

  7. Marble waste characterization as a desulfurizing slag component for steel

    International Nuclear Information System (INIS)

    Coleti, J.L.; Grillo, F.F.; Tenorio, J.A.S.; De Oliveira, J.R.

    2014-01-01

    The current steel market requires from steel plants better quality of its products. As a result, steel plants need to search for improvements and costs reduction in its process. Hence, the residue of marble containing significant quantities of calcium and magnesium carbonates, raw materials of steel refining slag, was characterized in order to replace the conventional lime used. Therefore, it will be possible to reduce the cost and volume of waste produced by the ornamental rock industry. The following methods were applied to test the waste potential: SEM with EDS, x-ray diffraction, x-ray fluorescence (EDX), Thermogravimetry (TG) and analysis of surface area and particle size by the BET method using dispersion leisure. The results indicated the feasibility of waste as raw material in the composition of desulfurizing slags. (author)

  8. Desulfurization and denitrogenation of coal during multi-stage hydropyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, N.; Li, W.; Li, B. [Chinese Academy of Sciences, Taiyuan (China). State Key Lab of Coal Conversion

    2001-02-01

    The elemental composition of char of high sulfur Hongmiao coal in multi-stage hydropyrolysis (MHyPy) with different heating rates were analysed and compared with that from normal hydropyrolysis (HyPy). The results illustrated that the sulfur removal in MHyPy was greater than that in HyPy, and more sulfur was evolved as the easily recycled gas H{sub 2}S. Similar with the situation of sulfur, more nitrogen transferred to the gas phase easily to be dealt with and the clean char was obtained. During MHyPy the extent of desulfurization and denitrogenation was more remarkable at high rate than that at slow heating rate. 8 refs., 2 figs., 2 tabs.

  9. STS-74 view of ODS from Payload Changout Room

    Science.gov (United States)

    1995-01-01

    Workers at Launch Pad 39A are preparing to close the payload bay doors on the Space Shuttle Atlantis for its upcoming launch on Mission STS-74 and the second docking with the Russian Space Station Mir. Uppermost in the payload bay is the Orbiter Docking System (ODS), which also flew on the first docking flight between the Space Shuttle and MIR. Lowermost is the primary payload of STS-74, the Russian-built Docking Module. During the mission, the Docking Module will first be attached to ODS and then to Mir. It will be left attached to Mir to become a permanent extension that will afford adequate clearance between the orbiter and the station during future dockings. At left in the payload bay, looking like a very long pole, is the Canadian-built Remote Manipulator System arm that will be used by the crew to hoist the Docking Module and attach it to the ODS.

  10. GRANULATION AND BRIQUETTING OF SOLID PRODUCTS FROM FLUE GAS DESULFURIZATION

    Directory of Open Access Journals (Sweden)

    Jan J. Hycnar

    2015-11-01

    Full Text Available Most flue gas desulfurization products can be characterized by significant solubility in water and dusting in dry state. These characteristics can cause a considerable pollution of air, water, and soil. Among many approaches to utilization of this waste, the process of agglomeration using granulation or briquetting has proved very effective. Using desulfurization products a new material of aggregate characteristics has been acquired, and this material is resistant to water and wind erosion as well as to the conditions of transportation and storage. The paper presents the results of industrial trials granulation and briquetting of calcium desulphurization products. The granulation of a mixture of phosphogypsum used with fly ash (in the share 1:5. The resulting granules characterized by a compressive strength of 41.6 MPa, the damping resistance of 70% and 14.2% abrasion. The granulate was used for the production of cement mix. The produced concrete mortar have a longer setting and hardening time, as compared to the traditional ash and gypsum mortar, and have a higher or comparable flexural and compressive strength during hardening. Briquetting trials made of a product called synthetic gypsum or rea-gypsum both in pure form and with the addition of 5% and 10% of the limestone dust. Briquettes have a high initial strength and resistance to abrasion. The values ​​of these parameters increased after 72 hours of seasoning. It was found that higher hardiness of briquettes with rea-gypsum was obtained with the impact of atmospheric conditions and higher resistance to elution of water-soluble components in comparison to ash briquettes.

  11. Applying ACF to desulfurization process from flue gas

    International Nuclear Information System (INIS)

    Liu Yi; Zhang Zhigang; Tang Qiang; Cao Zidong

    2004-01-01

    Inasmuch as the status of environmental pollution caused by SO 2 is more and more serious and the policy of environmental protection is executed more and more strictly, desulfurization from flue gas (FGD) is introduced to a wide-spread field of national economy. By a comparison with lime-limestone method, the application of adsorption method in FGD is more effective in desulfurization and more adapted to the situation of our country in respect of its more valuable byproduct. However, the technique of adsorption method is limited by the large amount of adsorbent used. In this paper, activated carbon fiber (ACF) is proposed as a new type of adsorbent to apply in FGD. A series of experiments have been made in order to compare the performances between ACF and granular activated carbon (GAC) which has been mostly used. Experiments show that under the same working conditions ACF's adsorption capacity is 16.6 times as high as that of GAC, mass loss rate is 1/12 of GAC's, desorption efficiency of ACF can reach 99.9%. The theory of micropore adsorption dynamics is adopted to analyze the characteristics of both adsorbents. It is indicated that adsorbability and perfectibility of desorption are tightly related to the distribution of pores and the surface micromechanism of adsorbent surface. The accessibility of pores for specified adsorptive and the effects of capillary condensation are crucial factors to influence the process of FGD. According to the research of different adsorbents, conclusion can be drawn that ACF is a kind of good material with a strong selectivity for SO 2 . Compared with the traditional methods of FGD, the use of ACF can greatly economize the consumption of adsorbent and obviously reduce the introduction of new adsorbent, and at the same time keep down the equipment investment and operating cost. (authors)

  12. The dynamics of the reaction of 16O(1D)+D218O→16OD+18OD

    International Nuclear Information System (INIS)

    Guillory, W.A.; Gericke, K.H.; Comes, F.J.

    1983-01-01

    The detailed energy partitioning in the reaction of a metastable oxygen atom O( 1 D) with D 2 O proceeding to two OD molecules has been studied. In order to distinguish the product state distribution between the two chemically identical product molecules OD, the oxygen atom in the heavy water molecule was labeled isotopically. The use of spectroscopic methods allows a complete analysis of the products' state distribution including such fine details as the distribution of the different #betta# components and of the electron spin. The vibrational energy is almost exclusively channeled into the new ( 16 OD) bond, whereas the original ( 18 OD) bond is produced (>90%) in the ground vibrational state. Both OD radicals show a broad rotational excitation and the rotational energy is equally partitioned among the two bonds. The energy distribution over the rovibrational levels strongly reflects the influence of coincident product molecules emerging from this chemical reaction. The reaction is very direct and must proceed on a time scale which does not allow for efficient energy transfer into all the available phase space

  13. Evaluation of Pb–17Li compatibility of ODS Fe-12Cr-5Al alloys

    Energy Technology Data Exchange (ETDEWEB)

    Unocic, Kinga A., E-mail: unocicka@ornl.gov; Hoelzer, David T.

    2016-10-15

    The Dual Coolant Lead Lithium (DCLL: eutectic Pb–17Li and He) blanket concept requires improved Pb–17Li compatibility with ferritic steels in order to demonstrate acceptable performance in fusion reactors. As an initial step, static Pb-17at.%Li (Pb-17Li) capsule experiments were conducted on new oxide dispersion strengthened (ODS) FeCrAl alloys ((1) Y{sub 2}O{sub 3} (125Y), (2) Y{sub 2}O{sub 3} + ZrO{sub 2} (125YZ), (3) Y{sub 2}O{sub 3} + HfO{sub 2} (125YH), and (4) Y{sub 2}O{sub 3} + TiO{sub 2} (125YT)) produced at ORNL via mechanical alloying (MA). Tests were conducted in static Pb–17Li for 1000 h at 700 °C. Alloys showed promising compatibility with Pb–17Li with small mass change after testing for 125YZ, 125YH and 125YT, while the 125Y alloy experienced the highest mass loss associated with some