Cristina Moliner

Experimental tests with rice straw on a square-based spouted bed reactor

Abstract A spouting bed reactor using rice straw as feedstock for further gasification purposes was studied in the present work. Experimental fluid dynamic tests were carried out in a conical square-based spouted bed reactor using a mixture of straw and silica, the latter acting as inert material. The influence of the initial bed of particles and the presence of coarse particles in the mixture on the pressure drop and minimum spouting velocity were evaluated. As a result, lower values of pressure drop along the bed were found compared to conventional fluidisation processes. Higher initial bed heights and higher percentage of straw in the mixture resulted in higher values of pressure drop and minimum spouting velocity. A new correlation for a cross section spouted bed reactor was proposed for the prediction of the minimum spouting velocity.

Comparative Study for the Energy Valorisation of Rice Straw

Comparative Study for the Energy Valorisation of Rice Straw Cristina Moliner*, Barbara Bosio, Elisabetta Arato, Amparo Ribes-Greus a Dipartimento di Ingegneria Civile, Chimica e Ambientale (DICCA). Università degli Studi di Genova, Via Opera Pia 15, 16145 Genova (Italy) b Departamento de Maquinas y Motores Termicos (CMT). Universidad Politècnica de València, Camino de Vera s/n, 46022. Valencia (Spain) cristina.moliner@edu.unige.it

Thermal and thermo-oxidative stability and kinetics of decomposition of PHBV/sisal composites

ABSTRACT The decomposition behaviours of composites made of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and sisal were assessed in terms of thermal stability and decomposition kinetics, under inert and oxidative conditions, by means of multi-rate linear non-isothermal thermogravimetric experiments. A statistical design of experiments was applied to study the influence of the addition of sisal (0–10–20–30%wt), the presence coupling agent (Yes/No) and the applied conditions of work (inert or oxidative). An improvement of the thermal and thermo-oxidative stability of PHBV with the addition of sisal was observed for all cases. An accurate methodology based on iso-conversional methods was applied to simulate the potential of thermal recovery technologies, such as pyrolysis and controlled combustion, to use these biocomposites after the end of their service life. The mathematical descriptions of both thermo-chemical reactions were helpful in the evaluation of the eventual optimal operational conditions to carry out a suitable energetic valorisation. A minimum of 240°C and 137 kJ/mol of activation energy in inert conditions and 236°C and 118 kJ/mol in oxidative conditions ensured the feasibility of the reactions regardless the composition of the PHBV/sisal biocomposites, which may ease the operability of further energy valorisation with the aim to turn biowaste into new fuels.

Reduction of Nitrates in Waste Water through the Valorization of Rice Straw: LIFE LIBERNITRATE Project

An improved and more sustainable waste management system is required for successful development of technologies based on renewable sources. Rice straw is submitted to controlled combustion reactions and the produced ashes are chemically treated to produce silica. After a chemical activation step, the activated silica shows potential as an adsorbent agent and will be used to remove the excess of nitrates in groundwater and wells in the area of Alginet (Valencia, Spain), selected as a vulnerable zone within the Nitrates Directive. The demonstration activity aims to have a local impact on municipalities of 200 inhabitants or fewer, decreasing from current nitrate concentrations close to 50 mg/L, to a target of 25 mg/L. In a successive step, the methodology will be transferred to other municipalities with similar nitrate problems (Piemonte, Italy) and replicated to remove different pollutants such as manure (the Netherlands) and waste waters from the textile industry (Italy).

A new approach to the solubility in aqueous salt solutions

Abstract The paper develops a new approach to the analysis of a solid–liquid phase diagram in terms of the chemical potentials of the single phases. The approach stems from the basic hypothesis that chemical potentials between different phases are equal at equilibrium. To make the idea operative, the mathematical dependence of the pertinent chemical potentials on the temperature and the mass fraction is determined by means of Aspen Plus; for definiteness a sodium chloride solution is examined. The phase diagram is established and the analytical properties of the curve are obtained. Moreover, the functional dependence of the mass fraction on the temperature at the freezing point is determined. The satisfactory agreement with new experimental data proves the validity of the procedure. The methodology so developed, provides an improved and rigorous mathematical overview for the analysis of phase diagrams. The approach is likely to be applicable to the investigation of solutions with several constituents or alloys.