This study is in the context of hydrogen production by thermal decomposition of methane for the purpose of reducing the CO2 footprint of hydrogen production processes. Experimental studies on methane ...conversion in a liquid tin bath were carried out and compared with existing kinetic data from other studies in order to identify a suitable reaction rate for the measured conversion. Experiments were conducted using a liquid tin bubble column stainless steel tube reactor with an inner diameter of 35.9 mm and a total length of 1150 mm, comprising a tin filling height of either 1000 mm or 600 mm. Methane gas was injected at flow rates in the range of 5–200 mln/min from the bottom of the reactor maintained at temperatures between 700 °C and 950 °C via a single hole orifice of diameter 1 mm. In general, methane conversion increased with increasing reactor temperatures and decreasing flow rates. The developed thermo-chemical model fitted well with the experimental data obtained during runs with the blank reactor. However, experimental data obtained at 900 °C at very low flow rates (≤25 mln/min – very high residence times and high conversion rates) appear to be much lower than predicted by the model. Further experiments and an improved model are required to understand the process and develop this technology further ahead.
•We investigated hydrogen production using thermal decomposition of methane.•Methane was injected into a bubble column reactor using tin as liquid media.•Methane decomposition was modeled by one first order reaction kinetic.•Liquid tin did not show a catalytic effect on the overall reaction.•A single first order kinetic is not sufficient for modeling methane decomposition.
The transition to a low-Carbon Hydrogen production will unavoidably follow a path where fossil fuels are going to play a fundamental role in the short term. The technological development of Hydrogen ...production based on sustainable, renewable energies (wind, solar, biomass) will most likely characterize the gradual substitution of fossil-based Hydrogen production in the long term. In this transition, the environmental concerns regarding greenhouse gas emissions to the atmosphere are a crucial issue, fostering the development of Hydrogen production scenarios in which either carbon capture and sequestration or decarburation could be implemented as mitigation or adaptation measures in order to avoid CO2 release from the utilization of fossil fuels. Therefore, the development of CO2-free technologies enabling fossil fuels exploitation is a must to make compatible their utilization with emission reductions. New innovative solutions should be put into practice. In this regard, methane cracking is a promising alternative and its potentials are highlighted and analyzed in this paper.
► Alternatives for CO2 Hydrogen production from fossils. ► Proposal of R&D to overcome technical difficulties. ► Coke formation and catalyst deactivation as main problems. ► Critical review of methane cracking.
The world energy demand is foreseen to increase due to the improvements of the living standard in the developing countries and to the development of the global economy. The increase in sustainability ...of the energy supply must be considered as a must to avoid spoiling the natural resources, whose availability will be crucial for next generations. The CO2-free utilization of available energy sources is one of the ways to attain such objectives. Innovative solutions should be put into practice for the CO2-free exploitation of the huge fossil fuel resources already available. In this paper we explore the possibility to enlarge the fossil fuel availability without CO2 emissions by the analysis of the technological options to obtain Hydrogen as energy carrier from hydrocarbon decarburation, mainly methane. A brief analysis of those options and a discussion about their state-of-the-art will be done, to establish their potential and the R&D required to assess their practical implementation in a medium term.
► Critical evaluation of methane cracking process. ► Proposal of R&D activities for the future regarding methane cracking. ► Coke formation and catalyst deactivation as main problems. ► Need for alternative reaction media.
•Methane pyrolysis in a liquid metal bubble column with a packed bed.•78% maximum hydrogen yield at 50mln/min methane volume flow rate and 1175°C.•Influence of different packed bed designs and feed ...gas dilution.•Carbon separation on the liquid metal interface.•No clogging issues due to solid carbon deposition.
Methane pyrolysis experiments using a quartz glass-steel bubble column reactor filled with liquid tin and cylindrical quartz glass rings serving as a packed bed were conducted at various liquid metal temperature levels in the range of 930–1175°C. Besides the liquid metal temperature, special attention was paid to the influence of the feed gas volume flow rate in the range of 50–200mln/min and the inlet feed gas dilution with nitrogen. Increasing liquid metal temperatures resulted in increasing hydrogen yields, leading to a maximum hydrogen yield of 78% at 1175°C and 50mln/min methane volume flow rate. Within all experimental runs, less than 1.5mol-% intermediate products were detected in the product gas. The produced carbon appeared as a powder consisting of flake shaped agglomerations in the size range of 15–20μm, wherein the particle size varied from 40nm to 100nm. During the experiments, the produced carbon was completely separated and accumulated at the top surface of the liquid metal. Only minor quantities were transported with the off gas stream. Within the liquid metal inventory, a thin carbon layer of about 10μm, probably partly showing the formation of nanotubes, in the hot reaction zone, had been deposited on the quartz glass reactor wall.
The decomposition of methane in a bubble column reactor, filled with tin, in combination with a packed bed, was investigated at different liquid metal temperature levels. All experiments were ...conducted with a methane feed gas volume flow rate in the range of 50–200 mln/min at temperatures up to 1273 K. The maximum hydrogen yield was 30% at 50 mln/min methane volume flow rate and a temperature level of 1273 K. The main components measured in the product gas were methane and hydrogen, intermediates were detected only in small amounts of less than 1.6 mol-%. The produced carbon was mainly accumulated as powder on top of the liquid metal interface. Within the liquid metal, only a thin carbon layer was deposited on the reactor wall. During the experiments, clogging issues due to solid carbon layers at the reactor wall did not occur. A thermo-chemical model was developed and implemented, taking into account the influence of the adjustable operating conditions as well as an experimentally determined gas residence time. Using the thermo-chemical model, a sensitivity analysis of the most dominant process parameters was performed, indicating that temperature and gas residence time have the strongest influence on the process. The model predictions were compared with the experimental results.
•Methane pyrolysis in a liquid metal bubble column with a packed bed.•30% maximum hydrogen yield at 50 mln/min methane volume flow rate and 1273 K.•New experimental setup without tin corrosion issues.•Carbon accumulated on top of the liquid metal interface without clogging issues.•Thermo-chemical model predictions are in line with the experimental results.
.
The neutron time-of-flight facility n_TOF features a white neutron source produced by spallation through 20GeV/
c
protons impinging on a lead target. The facility, aiming primarily at the ...measurement of neutron-induced reaction cross sections, was operating at CERN between 2001 and 2004, and then underwent a major upgrade in 2008. This paper presents in detail all the characteristics of the new neutron beam in the currently available configurations, which correspond to two different collimation systems and two choices of neutron moderator. The characteristics discussed include the intensity and energy dependence of the neutron flux, the spatial profile of the beam, the in-beam background components and the energy resolution/broadening. The discussion of these features is based on dedicated measurements and Monte Carlo simulations, and includes estimations of the systematic uncertainties of the mentioned quantities.
The ICARUS collaboration employed the 760-ton T600 detector in a successful 3-year physics run at the underground LNGS laboratory, performing a sensitive search for LSND-like anomalous
ν
e
appearance ...in the CERN Neutrino to Gran Sasso beam, which contributed to the constraints on the allowed neutrino oscillation parameters to a narrow region around 1 eV
2
. After a significant overhaul at CERN, the T600 detector has been installed at Fermilab. In 2020 the cryogenic commissioning began with detector cool down, liquid argon filling and recirculation. ICARUS then started its operations collecting the first neutrino events from the booster neutrino beam (BNB) and the Neutrinos at the Main Injector (NuMI) beam off-axis, which were used to test the ICARUS event selection, reconstruction and analysis algorithms. ICARUS successfully completed its commissioning phase in June 2022. The first goal of the ICARUS data taking will be a study to either confirm or refute the claim by Neutrino-4 short-baseline reactor experiment. ICARUS will also perform measurement of neutrino cross sections with the NuMI beam and several Beyond Standard Model searches. After the first year of operations, ICARUS will search for evidence of sterile neutrinos jointly with the Short-Baseline Near Detector, within the Short-Baseline Neutrino program. In this paper, the main activities carried out during the overhauling and installation phases are highlighted. Preliminary technical results from the ICARUS commissioning data with the BNB and NuMI beams are presented both in terms of performance of all ICARUS subsystems and of capability to select and reconstruct neutrino events.
The analysis of the viability of Hydrogen production without CO
2 emissions is one of the most challenging activities that have been initiated for a sustainable energy supply. As one of the tracks to ...fulfil such objective, direct methane cracking has been analysed experimentally to assess the scientific viability and reaction characterization in a broad temperature range, from 875 to 1700
°C. The effect of temperature, sweeping/carrier gas fraction proposed in some concepts, methane flow rate, residence time, and tube material and porosity has been analysed. The aggregation of carbon black particles to the reaction tube is the main technological show-stopper that has been identified.
► CO
2-free Hydrogen production from methane. ► Experimental methane cracking analysis. ► Black carbon plug as drawback for industrial application.
We report an early result from the ICARUS experiment on the search for a
ν
μ
→
ν
e
signal due to the LSND anomaly. The search was performed with the ICARUS T600 detector located at the Gran Sasso ...Laboratory, receiving CNGS neutrinos from CERN at an average energy of about 20 GeV, after a flight path of ∼730 km. The LSND anomaly would manifest as an excess of
ν
e
events, characterized by a fast energy oscillation averaging approximately to
with probability
. The present analysis is based on 1091 neutrino events, which are about 50 % of the ICARUS data collected in 2010–2011. Two clear
ν
e
events have been found, compared with the expectation of 3.7±0.6 events from conventional sources. Within the range of our observations, this result is compatible with the absence of a LSND anomaly. At 90 % and 99 % confidence levels the limits of 3.4 and 7.3 events corresponding to oscillation probabilities
and
are set respectively. The result strongly limits the window of open options for the LSND anomaly to a narrow region around (Δ
m
2
,sin
2
(2
θ
))
new
=(0.5 eV
2
,0.005), where there is an overall agreement (90 % CL) between the present ICARUS limit, the published limits of KARMEN and the published positive signals of LSND and MiniBooNE Collaborations.
Design, construction and tests of the ICARUS T600 detector Amerio, S.; Amoruso, S.; Antonello, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2004, Letnik:
527, Številka:
3
Journal Article
Recenzirano
We have constructed and operated the ICARUS T600 liquid argon (LAr) time projection chamber (TPC). The ICARUS T600 detector is the largest LAr TPC ever built, with a size of about
500
tons
of fully ...imaging mass. The design and assembly of the detector relied on industrial support and represents the applications of concepts matured in laboratory tests to the kton scale.
The ICARUS T600 was commissioned for a technical run that lasted about 3 months. During this period all the detector features were extensively tested with an exposure to cosmic-rays at surface with a resulting data collection of about 30
000 events.
The detector was developed as the first element of a modular design. Thanks to the concept of modularity, it will be possible to realize a detector with several ktons active mass, to act as an observatory for astroparticle and neutrino physics at the Gran Sasso Underground Laboratory and a second-generation nucleon decay experiment.
In this paper a description of the ICARUS T600 is given, detailing its design specifications, assembly procedures and acceptance tests. Commissioning procedures and results of the technical run are also reported, as well as results from the off-line event reconstruction.
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