1,721,020 research outputs found
Kinetics of Hydrolytic Degradation of PLA
No full textThe chemical recycling of poly(lactic acid) (PLA) to its monomer is crucial to reduce both the consumption of renewable resources for the monomer synthesis and the environmental impact related to its production and disposal. In particular, the production of lactic acid from PLA wastes, rather than from virgin raw materials, it is also possible to achieve considerable primary energy savings. The focus of this work is to analyse deeply the PLA hydrolytic decomposition by means of a kinetic model based on two reactions mechanism. To this end, new experimental data have been gathered in order to investigate a wider temperature range (from 140 to 180 A degrees C) and to extend the water/PLA ratio up to 50 % of PLA by weight. The reported results clearly highlight that more than 95 % of PLA is hydrolyzed to water-soluble lactic acid within 120 min, when it is hydrolyzed within 160-180 A degrees C. Furthermore, the kinetic constant is highly influenced by reaction temperature. The proposed "two reactions" kinetic mechanism complies satisfactorily with the experimental data under analysis.The chemical recycling of poly(lactic acid)
(PLA) to its monomer is crucial to reduce both the consumption
of renewable resources for the monomer synthesis
and the environmental impact related to its
production and disposal. In particular, the production of
lactic acid from PLA wastes, rather than from virgin raw
materials, it is also possible to achieve considerable primary
energy savings. The focus of this work is to analyse
deeply the PLA hydrolytic decomposition by means of a
kinetic model based on two reactions mechanism. To this
end, new experimental data have been gathered in order to
investigate a wider temperature range (from 140 to 180 C)
and to extend the water/PLA ratio up to 50 % of PLA by
weight. The reported results clearly highlight that more
than 95 % of PLA is hydrolyzed to water-soluble lactic
acid within 120 min, when it is hydrolyzed within
160–180 C. Furthermore, the kinetic constant is highly
influenced by reaction temperature. The proposed ‘‘two
reactions’’ k
Solar enriched methane production by steam reforming process: Reactor design
No full textA novel hybrid plant for a mixture of methane and hydrogen (enriched methane) production from a steam reforming reactor whose heat duty is supplied by a molten salt stream heated up by a concentrating solar power (CSP) plant developed by ENEA is here presented. By this way, a hydrogen stream, mixed with natural gas, is produced from solar energy by a consolidated production method as the steam reforming process and by a pre-commercial technology as molten salts parabolic mirrors solar plant. After the hydrogen production plant, the residual heat stored in molten salt stream is used to produce electricity and the plant is co-generative (hydrogen + electricity). The heat-exchanger-shaped reactor is dimensioned by a design tool developed in MatLab environment. A reactor 3.5 m long and with a diameter of 2′′ is the most efficient in terms of methane conversion (14.8%) and catalyst efficiency (4.7 Nm 3/h of hydrogen produced per kgcat). © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights
ATTIVITA’ DI RICERCA E SVILUPPO DEL GRUPPO DI REATTORI CHIMICI DELL’UNIVERSITA’ “LA SAPIENZA” DI ROMA
No full text
Experimental equilibrium data and thermodynamic modelling on the system water triethylene glycol
No full textALBUMIN-BOUND TOXIN REMOVAL IN LIVER SUPPORT DEVICES: CASE STUDY OF TRYPTOPHAN ADSORPTION AND DIALYSIS
No full textG.Marino, E. Bardone, A. Viglia Ed
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