105,586 research outputs found
Hydrogen from clean biogas: A proof of concept of integrated process
No full textThe steam reforming (SR) of natural gas plays a key role in the production of syngas (CO + H2) or H2, widely used to produce chemicals, fuels or energy. However, the depletion of fossil fuels and the increasing environmental constrains, have in the last decades prompted the attention towards renewable fuels. The main candidate to replace the natural gas (NG) is the biogas obtained by anaerobic fermentation of organic wastes or not edible biomass that, after removal of most pollutant compounds, is a mixture of CH4 and CO2 (clean biogas or CB) in variable amounts (35-50 vol.%) [1]. Currently CB is used to produce energy in cogeneration plants or biomethane (by CO2 SWAP) to be introduced in the NG distribution grid. The Dry Reforming (DR) may potentially convert both CH4 and CO2, although the many drawbacks (high reaction temperature and catalyst deactivation) limit its commercialization. Steam Reforming (SR) is an attractive option, although the CO2 fraction is barely converted in presence of high steam contents, decreasing the overall productivity. A promising upgrading is represented by the combined S/DR process, in which by controlling the amount of steam fed it is possible to limit catalyst deactivation and obtain syngas directly suitable for downstream applications as hydrocarbon or methanol synthesis. The syngas may be further upgraded through the Water Gas Shift (WGS) reaction, that allows to tune the H2/CO ratio or to improve the H2 production, developing an integrated processcatalysts, prepared by controlled calcination of hydrotalcite-type (HT) precursors, to be investigated in S/DR of CB or WGS of the obtained syngas [2,3]. The catalysts were deeply characterized before and after the tests to collect useful information to improve the performances by tuning catalyst composition and properties.
A Ni-Mg-Al (Ni 10 wt.%) was used as benchmark evidencing a low activity together with a fast deactivation due to carbon formation and/or Ni0 reoxidation. The addition of very small amounts of Rh gave rise to a significant increase of activity and stability with time-on-stream, regardless of the reaction conditions adopted. The H2/CO molar ratio of the outlet stream was between 1.2-2.7 as a function of the temperature and amount of steam fed. Adding a further WGS step at high (HTS) or, better, medium (MTS) temperature it was possible to increase the H2-content in the outlet stream, lowering the CO content in the outlet stream to < 1.2 vol.%. The data collected support the conceptual idea of a process, integrating S/DR and WGS steps. Aim of this work was to proof this idea by developing new Ni-based catalysts and Cu-based, with a configuration leading to advantages in the energy balance of the process and decreasing the capital and operational expenditures (CAPEX and OPEX).
1. E. Lindkvist and M. Karlsson, J. Cleaner Prod. 174, 1588-1597 (2018).
2. G. Brenna, A. Vaccari, F. Basile, G. Fornasari, R. Faure and D. Gary, EP 2,599,541 (2013) to Air Liquide.
3. R. Faure, D. Gary, G. Fornasari, A. Vaccari, C. Lucarelli, N. Schiaroli, EP 3,254,760 A1 (2016) to Air Liquide and ALMA MATER STUDIORUM – Università di Bologna.
M. RENNA, S. VACCARI, Commento all’art. 12 “Esclusioni specifiche per le concessioni nel settore idrico”, in G. ESPOSITO (a cura di), Codice dei contratti pubblici. Commentario di dottrina e giurisprudenza, Torino, Utet, 2017, I, pagg. 113 ss.
No full textCommento art. 12, d.lgs. 50/2016 "Esclusioni specifiche per le concessioni nel settore idrico
M. RENNA, S. VACCARI, Commento all’art. 12 “Esclusioni specifiche per le concessioni nel settore idrico”, in G. ESPOSITO (a cura di), Codice dei contratti pubblici. Commentario di dottrina e giurisprudenza, Torino, Utet, 2017, I, pagg. 113 ss
No full textCommento art. 12, d.lgs. 50/2016 "Esclusioni specifiche per le concessioni nel settore idrico
Neonatal hypothyroidism induces striatal dopaminergic dysfunction
No full textOral administration of the antithyroid drug methimazole (50 mg/kg per day) to rats during the last six days of pregnancy, and subsequent daily s.c. injection of methimazole (20-30 mg/kg) to their pups from birth to postnatal day 30 provoked hormonal and somatic alterations resembling (with all caution to any association between rodent and human data) those of congenital hypothyroidism. The steady-state concentrations of striatal dopamine were similar in hypothyroid and euthyroid, 32-day-old rats, while the levels of the dopamine metabolites 3,4-dihydroxyphenylacetic and homovanillic acids were markedly decreased in hypothyroidism. The results of this and our earlier study [Vaccari A. and Gessa G. L. (1989) Neurochem. Res. 14, 949-955] show that the maximal synaptosomal uptake of [3H]dopamine, an index for the density of nigrostriatal dopaminergic terminals, and the maximum number of membrane [3H]tyramine binding sites, reflecting the concentration of the vesicular transporter for dopamine, were decreased in the hypothyroid striatum. There was also a loss of those D1-type dopaminergic receptors claimed to be located on neurons intrinsic to the striatum, and, consequently, dopamine-stimulated, D1-regulated adenylate cyclase activity was depressed. It is suggested that individual dopaminergic nerve endings in the neonatal hypothyroid striatum must contain more dopamine, owing to some loss of pertinent innervation and, therefore, to the presence of less vesicular transport sites for dopamine. Hypothyroidism-related decreases in the maximum number of striatal D1- and, reportedly, D2-receptors, plus the impairment of D1-coupled second messenger activity, may play a role in the derangement of those neurobehavioural patterns where a dopaminergic regulation is putatively implied
M. RENNA, S. VACCARI, Commento all’art. 13 “Appalti nei settori speciali aggiudicati a scopo di rivendita o di locazione a terzi”, in G. ESPOSITO (a cura di), Codice dei contratti pubblici. Commentario di dottrina e giurisprudenza, Torino, Utet, 2017, I, pagg. 122 ss
No full textCommento art. 13, d.lgs. 50/2016 "Appalti nei settori speciali aggiudicati a scopo di rivendita o di locazione a terzi
M. RENNA, S. VACCARI, Commento all’art. 11 “Appalti aggiudicati da particolari enti aggiudicatori per l’acquisto di acqua e per la fornitura di energia o di combustibili destinati alla produzione di energia”, in G. ESPOSITO (a cura di), Codice dei contratti pubblici. Commentario di dottrina e giurisprudenza, Torino, Utet, 2017, I, pagg. 107 ss
No full textCommento art. 11, d.lgs. 50/2016 "Appalti aggiudicati da particolari enti aggiudicatori per l'acquisto di acqua e per la fornitura di energia o di combustibili destinati alla produzione di energia"
M. RENNA, S. VACCARI, Commento all’art. 13 “Appalti nei settori speciali aggiudicati a scopo di rivendita o di locazione a terzi”, in G. ESPOSITO (a cura di), Codice dei contratti pubblici. Commentario di dottrina e giurisprudenza, Torino, Utet, 2017, I, pagg. 122 ss.
No full textCommento art. 13, d.lgs. 50/2016 "Appalti nei settori speciali aggiudicati a scopo di rivendita o di locazione a terzi
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