The Experts below are selected from a list of 504 Experts worldwide ranked by ideXlab platform

Bernard Dussardier - One of the best experts on this subject based on the ideXlab platform.

Kamiel Gabriel - One of the best experts on this subject based on the ideXlab platform.

  • assessment study of a four step copper chlorine cycle modified with Flash Vaporization process for hydrogen production
    International Journal of Hydrogen Energy, 2021
    Co-Authors: Faran Razi, Ibrahim Dincer, Kamiel Gabriel
    Abstract:

    Abstract This paper develops a four-step copper-chlorine cycle for hydrogen production with conceptual modification through Flash Vaporization and evaluates its economic and environmental performances through exergy approach. The Flash Vaporization method is employed as a new approach for realizing the anolyte separation under vacuum conditions for reducing the thermal requirement of the anolyte separation step and consequently of the overall cycle. A Flash Vaporization is usually employed commercially for seawater desalination purposes. However, its utilization in a thermochemical hydrogen production process has not been considered previously which is really one of primary novelties of this investigation. The obtained results for the exergoeconomic and exergoenvironmental analyses of the conceptually modified cycle are also compared with those of the existing integrated cycle at the Ontario Tech University. The exergoeconomic analysis of the cycle has also been carried out for the cycle operating with and without waste heat recovery. In this regard, waste heat recovery from a steel furnace has been considered for supplying the required thermal energy for the hydrolysis step. The cost assessment of the cycle is carried out in the Aspen-plus. Compared with the existing cycle, the cycle with the proposed modification results in a lower unit cost of hydrogen. Moreover, a significant reduction in the unit cost of hydrogen is observed when waste heat recovery is considered for the modified cycle. The average unit hydrogen cost for the modified version of the cycle is evaluated to be 4.7 $/kg which reduces to 2 $/kg with incorporation of waste heat recovery. Furthermore, the overall environmental impact of the existing cycle can be potentially minimized by considering the proposed modification through Flash Vaporization.

  • process improvement and analysis of an integrated four step copper chlorine cycle modified with a Flash Vaporization process for hydrogen production
    Energy & Fuels, 2021
    Co-Authors: Faran Razi, Ibrahim Dincer, Kamiel Gabriel
    Abstract:

    In this paper, we perform detailed energy and exergy analyses of a four-step integrated copper–chlorine cycle for hydrogen production. In this regard, we consider the incorporation of the Flash vap...

Christoph Knote - One of the best experts on this subject based on the ideXlab platform.

  • aircraft based observations of isoprene epoxydiol derived secondary organic aerosol iepox soa in the tropical upper troposphere over the amazon region
    Atmospheric Chemistry and Physics, 2018
    Co-Authors: Christiane Schulz, Johannes Schneider, Bruna Holanda, Oliver Appel, Anja Costa, V Dreiling, Daniel Futterer, Tina Jurkatwitschas, Thomas Klimach, Christoph Knote
    Abstract:

    Abstract. During the ACRIDICON-CHUVA field project (September–October 2014; based in Manaus, Brazil) aircraft-based in situ measurements of aerosol chemical composition were conducted in the tropical troposphere over the Amazon using the High Altitude and Long Range Research Aircraft (HALO), covering altitudes from the boundary layer (BL) height up to 14.4  km . The submicron non-refractory aerosol was characterized by Flash-Vaporization/electron impact-ionization aerosol particle mass spectrometry. The results show that significant secondary organic aerosol (SOA) formation by isoprene oxidation products occurs in the upper troposphere (UT), leading to increased organic aerosol mass concentrations above 10  km altitude. The median organic mass concentrations in the UT above 10  km range between 1.0 and 2.5  µ g m −3 (referring to standard temperature and pressure; STP) with interquartile ranges of 0.6 to 3.2  µ g m −3 (STP), representing 78 % of the total submicron non-refractory aerosol particle mass. The presence of isoprene-epoxydiol-derived secondary organic aerosol (IEPOX-SOA) was confirmed by marker peaks in the mass spectra. We estimate the contribution of IEPOX-SOA to the total organic aerosol in the UT to be about 20 %. After isoprene emission from vegetation, oxidation processes occur at low altitudes and/or during transport to higher altitudes, which may lead to the formation of IEPOX (one oxidation product of isoprene). Reactive uptake or condensation of IEPOX on preexisting particles leads to IEPOX-SOA formation and subsequently increasing organic mass in the UT. This organic mass increase was accompanied by an increase in the nitrate mass concentrations, most likely due to NOx production by lightning. Analysis of the ion ratio of NO+ to NO 2 + indicated that nitrate in the UT exists mainly in the form of organic nitrate. IEPOX-SOA and organic nitrates are coincident with each other, indicating that IEPOX-SOA forms in the UT either on acidic nitrate particles forming organic nitrates derived from IEPOX or on already neutralized organic nitrate aerosol particles.

Oliver Appel - One of the best experts on this subject based on the ideXlab platform.

  • design characterization and first field deployment of a novel aircraft based aerosol mass spectrometer combining the laser ablation and Flash Vaporization techniques
    Atmospheric Measurement Techniques Discussions, 2021
    Co-Authors: Oliver Appel, Andreas Hunig, Antonis Dragoneas, Sergej Molleker, Hanschristian Clemen, Frank Helleis
    Abstract:

    Abstract. In this paper, we present the design, development, and characteristics of the novel aerosol mass spectrometer ERICA (ERC Instrument for Chemical composition of Aerosols) and selected results from the first aircraft-borne field deployment. The instrument combines two well-established methods of real-time in-situ measurements of fine particle chemical composition. The first method is the single particle laser ablation technique (here with a frequency-quadrupled Nd:YAG laser at λ = 266 nm). The other method is a combination of Flash Vaporization and electron impact ionization (like the Aerodyne aerosol mass spectrometer). The aerosol sample can be analyzed with both methods, each using time-of-flight mass spectrometry. By means of the laser ablation, single particles are qualitatively analyzed (including the refractory components) while the Flash Vaporization and electron impact ionization technique provides quantitative information on the non-refractory components (i.e., particulate sulfate, nitrate, ammonia, organics, and chloride) of small particle ensembles. These techniques are implemented in two consecutive instrument stages within a common sample inlet and a common vacuum chamber. At its front end, the sample air containing the aerosol particles is continuously injected via an aerodynamic lens (ADL). All particles which are not ablated by the Nd:YAG laser in the first instrument stage continue their flight until they reach the second instrument stage and impact on the vaporizer surface (operated at 600 °C). The ERICA is capable of detecting single particles with vacuum aerodynamic diameters (dva) between ~ 180 nm and 3170 nm (d50 cut-off). The chemical characterization of single particles is achieved by recording cations and anions with a bipolar time-of-flight mass spectrometer (B-ToF-MS). For the measurement of non-refractory components, the particle size range extends from approximately 120 nm to 3.5 µm (d50 cut-off; dva), and the cations are detected with a C-ToF-MS (compact time-of-flight mass spectrometer). The compact dimensions of the instrument are such that the ERICA can be deployed on aircraft, ground stations, or mobile laboratories . During its first deployments the instrument operated fully automated during 11 research flights on the Russian high-altitude research aircraft M-55 Geophysica from ground pressure and temperature up to 20 km altitude at 55 hPa and ambient temperatures as low as −86 °C.

  • aircraft based observations of isoprene epoxydiol derived secondary organic aerosol iepox soa in the tropical upper troposphere over the amazon region
    Atmospheric Chemistry and Physics, 2018
    Co-Authors: Christiane Schulz, Johannes Schneider, Bruna Holanda, Oliver Appel, Anja Costa, V Dreiling, Daniel Futterer, Tina Jurkatwitschas, Thomas Klimach, Christoph Knote
    Abstract:

    Abstract. During the ACRIDICON-CHUVA field project (September–October 2014; based in Manaus, Brazil) aircraft-based in situ measurements of aerosol chemical composition were conducted in the tropical troposphere over the Amazon using the High Altitude and Long Range Research Aircraft (HALO), covering altitudes from the boundary layer (BL) height up to 14.4  km . The submicron non-refractory aerosol was characterized by Flash-Vaporization/electron impact-ionization aerosol particle mass spectrometry. The results show that significant secondary organic aerosol (SOA) formation by isoprene oxidation products occurs in the upper troposphere (UT), leading to increased organic aerosol mass concentrations above 10  km altitude. The median organic mass concentrations in the UT above 10  km range between 1.0 and 2.5  µ g m −3 (referring to standard temperature and pressure; STP) with interquartile ranges of 0.6 to 3.2  µ g m −3 (STP), representing 78 % of the total submicron non-refractory aerosol particle mass. The presence of isoprene-epoxydiol-derived secondary organic aerosol (IEPOX-SOA) was confirmed by marker peaks in the mass spectra. We estimate the contribution of IEPOX-SOA to the total organic aerosol in the UT to be about 20 %. After isoprene emission from vegetation, oxidation processes occur at low altitudes and/or during transport to higher altitudes, which may lead to the formation of IEPOX (one oxidation product of isoprene). Reactive uptake or condensation of IEPOX on preexisting particles leads to IEPOX-SOA formation and subsequently increasing organic mass in the UT. This organic mass increase was accompanied by an increase in the nitrate mass concentrations, most likely due to NOx production by lightning. Analysis of the ion ratio of NO+ to NO 2 + indicated that nitrate in the UT exists mainly in the form of organic nitrate. IEPOX-SOA and organic nitrates are coincident with each other, indicating that IEPOX-SOA forms in the UT either on acidic nitrate particles forming organic nitrates derived from IEPOX or on already neutralized organic nitrate aerosol particles.

Jeanfrancois Lupi - One of the best experts on this subject based on the ideXlab platform.