Characterization of the devolatilization rate of solid fuels in fluidized beds by time-resolved pressure measurements

The characterization of volatile matter (VM) emission from solid fuel particles during fluidized bed combustion/gasification is relevant to reactor performance influencing the fate of VM as it results from competing phenomena of release, mixing/segregation and burn-out. The rate and the time-history of volatile matter release strongly affect axial segregation of fuel particles in the bed, favoring the establishment of the stratified combustion regime. On the other hand, the comparison between the devolatilization and radial solids mixing time scales affects the radial distribution of volatile matter across the reactor. Short devolatilization times determine VM release localized near feeding point. The knowledge of devolatilization kinetics, as determined by thermogravimetric analysis, does not take into account key process phenomena such as the effective time-temperature history of the devolatilizing particle. A novel and easy-to-use diagnostic technique for “in-situ” characterization of the devolatilization rate of fuel particles in gas fluidized beds is proposed in the present paper. It is based on the time-resolved measurement of pressure in a bench scale fluidized bed reactor equipped with a calibrated flow restriction at the exhaust. The procedure consists of the injection of a single fuel particle (or small batches of multiple particles) and continuous monitoring of the pressure in the reactor. The bed was kept at a constant temperature by external heating and fluidized with nitrogen. Gas pressure inside the reactor increases during devolatilization as a consequence of the increased flow rate, due to the emission of volatile matter, across the calibrated flow restriction at the exhaust. Experimental data are analyzed in the light of a model of the experiment based on the transient mass balance on the reactor volume referred to the fluidizing gas and to the volatile matter. The comparison between experimental pressure time series and model computations enables the characterization of the kinetic parameters of devolatilization rate for samples of different coals as well as of non-fossil solid fuels.

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The Generation and Characterization of Ultrashort Electron Pulses and their Application to Time-Resolved Electron Diffraction.

10.21236/ada308231 ◽

1996 ◽

Author(s):

Peter M. Weber

Keyword(s):

Electron Diffraction ◽

Time Resolved ◽

Electron Pulses

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Characterization of a Novel FRET Probe in a Crowded Environment using Time-Resolved Anisotropy

Biophysical Journal ◽

10.1016/j.bpj.2016.11.1878 ◽

2017 ◽

Vol 112 (3) ◽

pp. 346a

Author(s):

Hannah Leopold ◽

Megan Currie ◽

Jacob Schwarz ◽

Arnold J. Boersma ◽

Erin D. Sheets ◽

...

Keyword(s):

Time Resolved ◽

Crowded Environment

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KD determination from time-resolved experiments on live cells with LigandTracer and reconciliation with end-point flow cytometry measurements

European Biophysics Journal ◽

10.1007/s00249-021-01560-2 ◽

2021 ◽

Author(s):

Diana Spiegelberg ◽

Jonas Stenberg ◽

Pascale Richalet ◽

Marc Vanhove

Keyword(s):

Flow Cytometry ◽

Live Cells ◽

Time Resolved ◽

Surface Receptors ◽

Full Characterization ◽

End Point ◽

Titration Curves ◽

Kinetics Of

AbstractDesign of next-generation therapeutics comes with new challenges and emulates technology and methods to meet them. Characterizing the binding of either natural ligands or therapeutic proteins to cell-surface receptors, for which relevant recombinant versions may not exist, represents one of these challenges. Here we report the characterization of the interaction of five different antibody therapeutics (Trastuzumab, Rituximab, Panitumumab, Pertuzumab, and Cetuximab) with their cognate target receptors using LigandTracer. The method offers the advantage of being performed on live cells, alleviating the need for a recombinant source of the receptor. Furthermore, time-resolved measurements, in addition to allowing the determination of the affinity of the studied drug to its target, give access to the binding kinetics thereby providing a full characterization of the system. In this study, we also compared time-resolved LigandTracer data with end-point KD determination from flow cytometry experiments and hypothesize that discrepancies between these two approaches, when they exist, generally come from flow cytometry titration curves being acquired prior to full equilibration of the system. Our data, however, show that knowledge of the kinetics of the interaction allows to reconcile the data obtained by flow cytometry and LigandTracer and demonstrate the complementarity of these two methods.

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Time-Resolved Spectroscopic Study of N,N-Di(4-bromo)nitrenium Ions in Selected Solutions

Molecules ◽

10.3390/molecules23123182 ◽

2018 ◽

Vol 23 (12) ◽

pp. 3182 ◽

Cited By ~ 5

Author(s):

Lili Du ◽

Xin Lan ◽

Zhiping Yan ◽

Ruixue Zhu ◽

David Phillips

Keyword(s):

Transient Absorption ◽

Direct Detection ◽

Reaction Pathway ◽

Addition Reactions ◽

Time Resolved ◽

Nitrenium Ions ◽

Future Studies ◽

Nitrenium Ion ◽

Design Time

Nitrenium ions are important reactive intermediates in chemistry and biology. In this work, femtosecond and nanosecond transient absorption (fs-TA and ns-TA) along with nanosecond time-resolved resonance Raman (ns-TR3) experiments were employed to examine the photochemical pathways of N-(4,4′-dibromodiphenylamino)-2,4,6-trimethylpyridinium BF4− (salt (DN) from just absorption of a photon of light to the production of the important N,N-di(4-bromophenyl)nitrenium ion 2. In acetonitrile (MeCN), the formation of halogenated diarylnitrenium ion 2 was observed within 4 ps, showing the vibrational spectra with strong intensity. The nucleophilic adduct reaction of ion 2 with H2O was also examined in aqueous solutions. The direct detection of the unique ortho adduct intermediate 3 shows that there is an efficient and exclusive reaction pathway for 2 with H2O. The results shown in this paper give new characterization of 2, which can be used to design time-resolved spectroscopy investigations of covalent addition reactions of nitrenium ions with other molecules in future studies.

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