The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
M.b. Chang - One of the best experts on this subject based on the ideXlab platform.
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Removal of phenol from Gas Streams via combined plasma catalysis
Journal of Industrial and Engineering Chemistry, 2017Co-Authors: Kuan Lun Pan, Dai Ling Chen, Guan Ting Pan, Siewhui Chong, M.b. ChangAbstract:Abstract A hybrid system consisting of non-thermal plasma and perovskite-like catalyst is developed and evaluated for the effectiveness in removing phenol from Gas Streams. For thermal catalysis, La0.8Sr0.2Mn0.8Cu0.2O3 shows high activity for phenol removal. Further, La0.8Sr0.2Mn0.8Cu0.2O3 is applied for combined plasma catalysis (CPC). The results indicate that phenol removal efficiency with CPC remains 100% at applied voltage range of 13–16 kV. Importantly, secondary pollutants (O3 and NOx) and energy efficiency can be inhibited and increased, respectively, as CPC is applied. Overall, this study demonstrates that combining non-thermal plasma with perovskite-like catalyst is effective in removing phenol from Gas Streams.
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Plasma-Assisted Process for Removing NO/NOx from Gas Streams with C2H4 as Additive
Journal of Environmental Engineering, 2003Co-Authors: How Ming Lee, M.b. Chang, Shyh Chaur YangAbstract:NOx removal from Gas Streams via dielectric barrier discharges (DBDs) has been experimentally evaluated. This paper investigates the effect of injecting C2H4 as an additive with respect to the De-NOx chemistry and the effect of Gas composition on NO/NOx removal efficiencies. Experimental results indicate that both removal efficiencies of NO and NOx are enhanced with increasing applied voltage, Gas temperature, and water vapor. Water vapor in Gas Streams has a distinct influence on NOx removal by generating OH radicals to convert NO2 to form HNO3. NOx removal decreases with increasing oxygen content although NO removal increases with increasing oxygen content. As high as 100% of NO and 57% of NOx are removed at 140°C for the Gas stream containing [NO]:[C2H4]:[H2O(g)]:[O2]:[N2]=0.05:0.2:3.0:5.0:91.75. Major mechanisms for NO and NOx removals in DBD processing with C2H4 as an additive are described in the text.
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Destruction and removal of toluene and MEK from Gas Streams with silent discharge plasmas
AIChE Journal, 1997Co-Authors: M.b. Chang, Chun-cheng ChangAbstract:The effectiveness of applying silent discharge plasmas (SDP) for destroying and removing volatile organic compounds (VOCs) from Gas Streams is experimentally evaluated with a laboratory-scale reactor. The VOCs selected for study include toluene and methyl ethyl ketone (MEK). Direct collision with energetic electrons and reaction with generated Gas-phase radicals are two major mechanisms responsible for destruction and removal of VOCs from Gas Streams. Operating parameters investigated include applied voltage, Gas residence time, and temperature and composition of the Gas stream. Experimental results indicate that the removal efficiency of toluene and MEK achieved with SDP can be enhanced by operating the system at a higher Gas temperature and applied voltage due to the generation of more energetic electrons and radicals. O{sub 2} is essential for removing VOCs from Gas Streams with SDP. More than 80% removal efficiencies were achieved with this system for both toluene and MEK. SDP can potentially serve as an alternative control technology for removing VOCs from Gas Streams.
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Removal of SO2 and NO from Gas Streams with Combined Plasma Photolysis
Journal of Environmental Engineering, 1993Co-Authors: M.b. Chang, Mark J Kushner, Maarten J. RoodAbstract:Combined plasma photolysis (CPP) has been developed and experimentally demonstrated as a new method to simultaneously remove SO\d2 and NO from Gas Streams. This laboratory-scale device integrates the use of a dielectric barrier discharge (DBD) plasma and ultraviolet radiation. The composition, temperature, and pressure of the treated Gas Streams simulate Gases typically generated by the combustion of fossil fuels. Simultaneous removal efficiencies for SO\d2 and NO are as high as 29% and 79%, respectively. CPP enhances SO\d2 removal efficiencies by 25% when compared to using DBDs only. NO removal efficiency achieved by CPP is 9% less than NO removal efficiency achieved by DBDs only. SO\d2 and NO removal efficiencies are limited by the power deposited into the Gas stream that could be achieved with the existing power supply. This new device shows promise as a new technique to simultaneously remove SO\d2 and NO from Gas Streams generated by the combustion of fossil fuels.
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Removal of SO2 and the simultaneous removal of SO2 and NO from simulated flue Gas Streams using dielectric barrier discharge plasmas
Plasma Chemistry and Plasma Processing, 1992Co-Authors: M.b. Chang, Mark J Kushner, Maarten J. RoodAbstract:A Gas-phase oxidation method using dielectric barrier discharges (DBDs) has been developed to remove SO2 and to simultaneously remove SO2 and NO from Gas Streams that are similar to Gas Streams generated by the combustion of fossil fuels. SO2 and NO removal efficiencies are evaluated as a function of applied voltage, temperature, and concentrations of SO2, NO, H2O(g), and NH3. With constant H2O(g) concentration, both SO2 and NO removal efficiencies increase with increasing temperature from 100 to 160°C. At 160°C with 15% by volume H20(g), more than 95% of the NO and 32% of the S02 are simultaneously removed from the Gas stream. Injection of NH3 into the Gas stream caused an increase in S02 removal efficiency to essentially 100%. These results indicate that DBD plasmas have the potential to simultaneously remove SO2 and NO from Gas Streams generated by large-scale fossil fuel combustors.
Norollah Kasiri - One of the best experts on this subject based on the ideXlab platform.
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A Novel Chemical Surface Modification for the Fabrication of PEBA/SiO2 Nanocomposite Membranes To Separate CO2 from SynGas and Natural Gas Streams
Industrial & Engineering Chemistry Research, 2014Co-Authors: Ali Ghadimi, Toraj Mohammadi, Norollah KasiriAbstract:In this work, a novel chemical modification is introduced to fabricate poly(ether-block-amide)/silica (PEBA/SiO2) nanocomposite membranes for the separation of CO2 from synGas and natural Gas Streams. cis-9-Octadecenoic acid (OA) was utilized for surface modification of the nanoparticles to restrict their agglomeration within the polymeric matrix. To our best knowledge, there is no evidence about the application of this modifier agent for the fabrication of nanocomposite membranes. The separation performance of fabricated membranes was investigated by pure and mixed Gas permeation experiments. The incorporation of modified nanoparticles into the polymeric matrix improved the separation performance of the fabricated nanocomposite membranes. For instance, by increasing the loading content of the SiO2 nanoparticles from 0 wt % (the neat PEBA membrane) to 8 wt %, at 25 °C and 2 bar, the ideal selectivity values of CO2/H2, CO2/CH4, and CO2/N2 were improved from 9, 18, and 61 to 17, 45, and 137, respectively.
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a novel chemical surface modification for the fabrication of peba sio2 nanocomposite membranes to separate co2 from synGas and natural Gas Streams
Industrial & Engineering Chemistry Research, 2014Co-Authors: Ali Ghadimi, Toraj Mohammadi, Norollah KasiriAbstract:In this work, a novel chemical modification is introduced to fabricate poly(ether-block-amide)/silica (PEBA/SiO2) nanocomposite membranes for the separation of CO2 from synGas and natural Gas Streams. cis-9-Octadecenoic acid (OA) was utilized for surface modification of the nanoparticles to restrict their agglomeration within the polymeric matrix. To our best knowledge, there is no evidence about the application of this modifier agent for the fabrication of nanocomposite membranes. The separation performance of fabricated membranes was investigated by pure and mixed Gas permeation experiments. The incorporation of modified nanoparticles into the polymeric matrix improved the separation performance of the fabricated nanocomposite membranes. For instance, by increasing the loading content of the SiO2 nanoparticles from 0 wt % (the neat PEBA membrane) to 8 wt %, at 25 °C and 2 bar, the ideal selectivity values of CO2/H2, CO2/CH4, and CO2/N2 were improved from 9, 18, and 61 to 17, 45, and 137, respectively.
Robert C. Brown - One of the best experts on this subject based on the ideXlab platform.
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Analysis of trace contaminants in hot Gas Streams using time-weighted average solid-phase microextraction: Pilot-scale validation
Fuel, 2015Co-Authors: Patrick J. Woolcock, Jacek A. Koziel, Patrick A. Johnston, Robert C. Brown, Karl M. BroerAbstract:Abstract A new method was developed for collecting, identifying and quantifying contaminants in hot process Gas Streams using time-weighted average (TWA) passive sampling with retracted solid-phase microextraction (SPME) and Gas chromatography. The previous lab scale proof-of-concept with benzene was expanded to include the remaining major tar compounds of interest in synGas: toluene, styrene, indene, and naphthalene. The new method was tested on high T (⩾100 °C) process Gas from a pilot-scale fluidized bed Gasifier feeding switchgrass and compared side-by-side with conventional impingers-based method. Fourteen additional compounds were identified, representing 40–60% improvement over the conventional method’s detection capacity. Differences between the two methods were 1–20% and as much as 40–100% depending on the sampling location. Compared to the inconsistent conventional method, the SPME-TWA offered a simplified, solvent-free approach capable of drastically reducing sampling and sample preparation time and improving analytical reliability. The improved sensitivity of the new method enabled identification and quantification of VOCs beyond the capability of the conventional approaches, reaching concentrations in the ppb range (low mg/m 3 ). RSDs associated with the TWA-SPME were 3 , with successful measurement of tar concentrations at times >4000 ppm (up to 10 g/N m 3 ). The new method can be a valid alternative to the conventional method for light tar quantification under certain conditions. The opportunity also exists to exploit TWA-SPME for process Gas Streams analysis e.g., pyrolysis vapors and combustion exhaust.
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Analysis of trace contaminants in hot Gas Streams using time-weighted average solid-phase microextraction: Proof of concept
Journal of chromatography. A, 2013Co-Authors: Patrick J. Woolcock, Jacek A. Koziel, Patrick A. Johnston, Lingshuang Cai, Robert C. BrownAbstract:Abstract Time-weighted average (TWA) passive sampling using solid-phase microextraction (SPME) and Gas chromatography was investigated as a new method of collecting, identifying and quantifying contaminants in process Gas Streams. Unlike previous TWA-SPME techniques using the retracted fiber configuration (fiber within needle) to monitor ambient conditions or relatively stagnant Gases, this method was developed for fast-moving process Gas Streams at temperatures approaching 300 °C. The goal was to develop a consistent and reliable method of analyzing low concentrations of contaminants in hot Gas Streams without performing time-consuming exhaustive extraction with a slipstream. This work in particular aims to quantify trace tar compounds found in a synGas stream generated from biomass Gasification. This paper evaluates the concept of retracted SPME at high temperatures by testing the three essential requirements for TWA passive sampling: (1) zero-sink assumption, (2) consistent and reliable response by the sampling device to changing concentrations, and (3) equal concentrations in the bulk Gas stream relative to the face of the fiber syringe opening. Results indicated the method can accurately predict Gas stream concentrations at elevated temperatures. Evidence was also discovered to validate the existence of a second boundary layer within the fiber during the adsorption/absorption process. This limits the technique to operating within reasonable mass loadings and loading rates, established by appropriate sampling depths and times for concentrations of interest. A limit of quantification for the benzene model tar system was estimated at 0.02 g m−3 (8 ppm) with a limit of detection of 0.5 mg m−3 (200 ppb). Using the appropriate conditions, the technique was applied to a pilot-scale fluidized-bed Gasifier to verify its feasibility. Results from this test were in good agreement with literature and prior pilot plant operation, indicating the new method can measure low concentrations of tar in Gasification Streams.
Patrick J. Woolcock - One of the best experts on this subject based on the ideXlab platform.
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Analysis of trace contaminants in hot Gas Streams using time-weighted average solid-phase microextraction: Pilot-scale validation
Fuel, 2015Co-Authors: Patrick J. Woolcock, Jacek A. Koziel, Patrick A. Johnston, Robert C. Brown, Karl M. BroerAbstract:Abstract A new method was developed for collecting, identifying and quantifying contaminants in hot process Gas Streams using time-weighted average (TWA) passive sampling with retracted solid-phase microextraction (SPME) and Gas chromatography. The previous lab scale proof-of-concept with benzene was expanded to include the remaining major tar compounds of interest in synGas: toluene, styrene, indene, and naphthalene. The new method was tested on high T (⩾100 °C) process Gas from a pilot-scale fluidized bed Gasifier feeding switchgrass and compared side-by-side with conventional impingers-based method. Fourteen additional compounds were identified, representing 40–60% improvement over the conventional method’s detection capacity. Differences between the two methods were 1–20% and as much as 40–100% depending on the sampling location. Compared to the inconsistent conventional method, the SPME-TWA offered a simplified, solvent-free approach capable of drastically reducing sampling and sample preparation time and improving analytical reliability. The improved sensitivity of the new method enabled identification and quantification of VOCs beyond the capability of the conventional approaches, reaching concentrations in the ppb range (low mg/m 3 ). RSDs associated with the TWA-SPME were 3 , with successful measurement of tar concentrations at times >4000 ppm (up to 10 g/N m 3 ). The new method can be a valid alternative to the conventional method for light tar quantification under certain conditions. The opportunity also exists to exploit TWA-SPME for process Gas Streams analysis e.g., pyrolysis vapors and combustion exhaust.
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Analysis of trace contaminants in hot Gas Streams using time-weighted average solid-phase microextraction: Proof of concept
Journal of chromatography. A, 2013Co-Authors: Patrick J. Woolcock, Jacek A. Koziel, Patrick A. Johnston, Lingshuang Cai, Robert C. BrownAbstract:Abstract Time-weighted average (TWA) passive sampling using solid-phase microextraction (SPME) and Gas chromatography was investigated as a new method of collecting, identifying and quantifying contaminants in process Gas Streams. Unlike previous TWA-SPME techniques using the retracted fiber configuration (fiber within needle) to monitor ambient conditions or relatively stagnant Gases, this method was developed for fast-moving process Gas Streams at temperatures approaching 300 °C. The goal was to develop a consistent and reliable method of analyzing low concentrations of contaminants in hot Gas Streams without performing time-consuming exhaustive extraction with a slipstream. This work in particular aims to quantify trace tar compounds found in a synGas stream generated from biomass Gasification. This paper evaluates the concept of retracted SPME at high temperatures by testing the three essential requirements for TWA passive sampling: (1) zero-sink assumption, (2) consistent and reliable response by the sampling device to changing concentrations, and (3) equal concentrations in the bulk Gas stream relative to the face of the fiber syringe opening. Results indicated the method can accurately predict Gas stream concentrations at elevated temperatures. Evidence was also discovered to validate the existence of a second boundary layer within the fiber during the adsorption/absorption process. This limits the technique to operating within reasonable mass loadings and loading rates, established by appropriate sampling depths and times for concentrations of interest. A limit of quantification for the benzene model tar system was estimated at 0.02 g m−3 (8 ppm) with a limit of detection of 0.5 mg m−3 (200 ppb). Using the appropriate conditions, the technique was applied to a pilot-scale fluidized-bed Gasifier to verify its feasibility. Results from this test were in good agreement with literature and prior pilot plant operation, indicating the new method can measure low concentrations of tar in Gasification Streams.
Ali Ghadimi - One of the best experts on this subject based on the ideXlab platform.
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A Novel Chemical Surface Modification for the Fabrication of PEBA/SiO2 Nanocomposite Membranes To Separate CO2 from SynGas and Natural Gas Streams
Industrial & Engineering Chemistry Research, 2014Co-Authors: Ali Ghadimi, Toraj Mohammadi, Norollah KasiriAbstract:In this work, a novel chemical modification is introduced to fabricate poly(ether-block-amide)/silica (PEBA/SiO2) nanocomposite membranes for the separation of CO2 from synGas and natural Gas Streams. cis-9-Octadecenoic acid (OA) was utilized for surface modification of the nanoparticles to restrict their agglomeration within the polymeric matrix. To our best knowledge, there is no evidence about the application of this modifier agent for the fabrication of nanocomposite membranes. The separation performance of fabricated membranes was investigated by pure and mixed Gas permeation experiments. The incorporation of modified nanoparticles into the polymeric matrix improved the separation performance of the fabricated nanocomposite membranes. For instance, by increasing the loading content of the SiO2 nanoparticles from 0 wt % (the neat PEBA membrane) to 8 wt %, at 25 °C and 2 bar, the ideal selectivity values of CO2/H2, CO2/CH4, and CO2/N2 were improved from 9, 18, and 61 to 17, 45, and 137, respectively.
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a novel chemical surface modification for the fabrication of peba sio2 nanocomposite membranes to separate co2 from synGas and natural Gas Streams
Industrial & Engineering Chemistry Research, 2014Co-Authors: Ali Ghadimi, Toraj Mohammadi, Norollah KasiriAbstract:In this work, a novel chemical modification is introduced to fabricate poly(ether-block-amide)/silica (PEBA/SiO2) nanocomposite membranes for the separation of CO2 from synGas and natural Gas Streams. cis-9-Octadecenoic acid (OA) was utilized for surface modification of the nanoparticles to restrict their agglomeration within the polymeric matrix. To our best knowledge, there is no evidence about the application of this modifier agent for the fabrication of nanocomposite membranes. The separation performance of fabricated membranes was investigated by pure and mixed Gas permeation experiments. The incorporation of modified nanoparticles into the polymeric matrix improved the separation performance of the fabricated nanocomposite membranes. For instance, by increasing the loading content of the SiO2 nanoparticles from 0 wt % (the neat PEBA membrane) to 8 wt %, at 25 °C and 2 bar, the ideal selectivity values of CO2/H2, CO2/CH4, and CO2/N2 were improved from 9, 18, and 61 to 17, 45, and 137, respectively.
