Isopropyl alcohol vapour removal from diluted gaseous stream by adsorption: Experimental results and dynamic model

The gas phase adsorption of isopropyl alcohol (IPA) onto a commercial activated carbon at 30°C was investigated under different operating conditions. Fixed-bed experiments were performed to obtain equilibrium and kinetic data for IPA adsorption. The equilibrium data were fitted by means of the Langmuir equation and isotherm parameters were determined. A dynamic, isothermal, dilute solution adsorption model, based on the linear driving force (LDF) approximation, was developed to describe the kinetic adsorption behavior. A very good agreement between experimental and model results was found when a LDF mass-transfer-rate coefficient dependent on the gas concentration was used

Supercritical Equilibrium Data of the Systems Carbon Dioxide—Linalool and Carbon Dioxide—Orange Essential Oil

In this paper experimental equilibrium data on the system supercritical CO2–orange essential oil and the system supercritical CO2-linalool are reported at 323.15 K and 343.15 K, for pressures in the ranges 7.6–13.5 MPa. The behavior of the system supercritical CO2–orange essential oil was represented by means of thermodynamic model, based on Peng–Robinson equation of state. To this aim the orange essential oil was represented by a mixture of limonene, linalool and β-caryophyllene, selected to represent the classes of monoterpenes, oxygenated terpenes and sesquiterpenes respectively. The model uses only regression parameters calculated from binary sub-systems, CO2-limonene and CO2-β-caryophyllene (taken from literature) and CO2-linalool (calculated from the fitting of original data reported in the present work) thus being predictive with respect to the multicomponent mixture.In this paper experimental equilibrium data on the system supercritical CO2–orange essential oil and the system supercritical CO2-linalool are reported at 323.15 K and 343.15 K, for pressures in the ranges 7.6–13.5 MPa. The behavior of the system supercritical CO2–orange essential oil was represented by means of thermodynamic model, based on Peng–Robinson equation of state. To this aim the orange essential oil was represented by a mixture of limonene, linalool and β-caryophyllene, selected to represent the classes of monoterpenes, oxygenated terpenes and sesquiterpenes respectively. The model uses only regression parameters calculated from binary sub-systems, CO2-limonene and CO2-β-caryophyllene (taken from literature) and CO2-linalool (calculated from the fitting of original data reported in the present work) thus being predictive with respect to the multicomponent mixture

Phase equilibria and thermodynamic modeling of systems CO2 – bergamot oil and CO2 – linalyl acetate

In this paper experimental equilibrium data of the system CO2– bergamot essential oil are reported at323 K and 343 K, in the pressure range 7.8–13.1 MPa. Furthermore equilibrium data for the subsystemCO2– linalyl acetate at 323 K are reported in the pressure range 7.0–10.3 MPa. The equilibrium data arepredicted by means of two thermodynamic models based on Peng – Robinson and PC-SAFT equations ofstate. In particular the bergamot essential oil is described as a mixture of four components: limonene,linalool, linalyl acetate and beta-caryophyllene. In the models regression parameters are calculated fromdata of binary subsystems, CO2– limonene, CO2– linalool and CO2-beta-caryophyllene, and CO2– linalylacetate. Therefore both of the models are predictive with regard to the bergamot oil and show quite agood agreement (especially the Peng Robinson one) with respect to the experimental data

PLA recycling by hydrolysis at high temperature

In this work the process of PLA hydrolysis at high temperature was studied, in order to evaluate the possibility of chemical recycling of this polymer bio-based. In particular, the possibility to obtain the monomer of lactic acid from PLA degradation was investigated. The results of some preliminary tests, performed in a laboratory batch reactor at high temperature, are presented: the experimental results show that the complete degradation of PLA can be obtained in relatively low reaction times

Solar steam reforming for enriched methane production: Reactor configurations modeling and comparison

A solar low-temperature steam reforming process for the production of an Enriched Methane (EM) mixture composed by CH4 and H2 (20%vol) exploiting the solar energy stored in a Molten Salt stream heated up by a Concentrating Solar Plant (MS-CSP) is presented and simulated through a two-dimensional steam reforming reactor model. Two configurations are considered and compared: the Integrated Heat Exchanging (IHE) configuration, where the steam reformers are tubes-and-shell reactors continuously heated up by the hot MS stream, and the External Heat Exchanging (EHE) configuration composed by a series of heat exchangers and insulated reformers where the reactions are adiabatically driven. The effect of the main operating conditions as Gas Hourly Space Velocity (GHSV), inlet reactor temperature and reactant mixture composition is assessed for both the configurations, demonstrating the process feasibility. Furthermore, in order to increase the process performance, an electrical power generation unit is also included, exploiting the sensible heat of the residual MS stream after the EM production unit: in this case, with a feed of 2000 Nm3/h of natural gas, about 6130 Nm3/h of enriched methane and 475 kWel are produced with the EHE configuration, while 3720 Nm3/h and 585 kWel are obtained with IHE configuration. © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.A solar low-temperature steam reforming process for the production of an Enriched Methane (EM) mixture composed by CH4 and H2 (20%vol) exploiting the solar energy stored in a Molten Salt stream heated up by a Concentrating Solar Plant (MS-CSP) is presented and simulated through a two-dimensional steam reforming reactor model. Two configurations are considered and compared: the Integrated Heat Exchanging (IHE) configuration, where the steam reformers are tubes-and-shell reactors continuously heated up by the hot MS stream, and the External Heat Exchanging (EHE) configuration composed by a series of heat exchangers and insulated reformers where the reactions are adiabatically driven. The effect of the main operating conditions as Gas Hourly Space Velocity (GHSV), inlet reactor temperature and reactant mixture composition is assessed for both the configurations, demonstrating the process feasibility. Furthermore, in order to increase the process performance, an electrical power generatio

Degradation of post-consumer PLA. Hydrolysis of polymeric matrix and oligomers stabilization in aqueous phase

Degradation of post-consumer PLA to lactic acid was analysed in order to assess the economic feasibility of the PLA chemical recycling process. Hydrolysis of PLA, in batch reactor, was analysed in the temperature range of 443-473K, under autogenous pressure and a constant PLA to water ratio (equal to approximately 0.11 by weight), without the use of a catalyst. The experimental results suggest that the complete degradation of PLA can be obtained using relatively low reaction-times with the production of a mixture containing the monomer and traces of the dimer of lactic acid. The overall process was modelled using a two-step process: bulk degradation of PLA (in the solid or molten phase) with the solubilisation of low molecular weight oligomers, and their subsequent hydrolysis in water (stabilization). The model describes the trend of oligomer concentrations in the aqueous phase and PLA conversion as a function of time with both high accuracy and agreement with experimental results