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Study and optimization of aroma recovery from beer by pervaporation

This work studies the aroma extraction from beer by pervaporation, using a polyoctylmethylsiloxane/polyetherimide (POMS/PEI) composite asymmetric membrane. A response surface methodology (RSM) was used to describe the influence of the operating conditions (factors) on process performance. The factors considered for the design of experiments were the feed temperature, the feed velocity and the permeate pressure....

Comparison of nanosized gold-based and copper-based catalysts for the low-tempe...

In this paper the catalytic performances for the low-temperature water-gas shift reaction of Au/TiO2 type A (from World Gold Council), Au/CeO2 (developed at UPV-CSIC), CuO/Al2O3 (from BASF), and CuO/ZnO/ Al2O3 (from REB Research & Consulting) have been compared. The catalysts were characterized by different techniques such as Raman spectroscopy, BET surface area measurements, temperature-programmed reduction, a...

Influence of Sodium Cations of N3 Dye on the Photovoltaic Performance and Stabi...

We report on the effect of substituting the two tetrabutyl am-monium counter ions of the standard N719 dye by sodium ions on the performance and stability of dye-sensitized solar cells (DSCs). The disodium analogue of N719 in conjunction with a non-volatile electrolyte gives a conversion efficiency of 7.6% under standard global AM 1.5 sunlight. Devices maintain 99% of their initial performance after 1000 h unde...

Influence of Different Cations of N3 Dyes on Their Photovoltaic Performance and...

The N3 dye was modified by substituting two of its protons by potassium or sodium cations. The performance and stability of dye-sensitized solar cells incorporating the new dyes were evaluated under light soaking (1000W · m−2 )at50◦C. Photocurrent measurements demonstrated that proton substitution by potassiumcations rends the systemmore stable. Further characterization of the potassium-based ...

Polymeric Membrane Reactors

The aim of this chapter is the study of membrane reactors with polymeric membranes, particularly catalytic polymeric membranes. After an introduction where the main advantages and disadvantages of the use of polymeric membranes are summarised, a review of the main areas where they have been applied, integrated in chemical reactors, is presented. This excludes the field of bio-membranes processes, which is analy...

Implementing Bologna in Southern European countries: Comparative analysis of so...

From the European and national perspectives the analysis of policy implementation tends to focus on aspects related to the legal framework. At these levels, institutions offer "the vision of a triumphant march towards the objectives set for 2010" [Veiga, A., Amaral, A., 2006b, The open method of co-ordination and the implementation of Bologna process. Tert Educ Manage, 12(4): 283–295]. There are several f...

Simultaneous distillation-extraction of high-value volatile compounds from Cist...

The present paper describes a procedure to isolate volatiles from rock-rose (Cistus ladanifer L.) using simultaneous distillation–extraction (SDE). High-value volatile compounds (HVVC) were selected and the influence of the extraction conditions investigated. The effect of the solvent nature and extraction time on SDE efficiency was studied. The best performance was achieved with pentane in 1 h operation....

Pre-Treatment Effect on the Transport Properties of Sulfonated Poly(ether ether...

Teaching Laminar-Flow Reactors: From Experimentation to CFD Simulation

An integrated chemical engineering lab experiment is described in this paper. It makes use of a laminar-flow tubular reactor (LFTR) through consecutive lab sessions. In a first session (not described here), the pseudo first-order kinetic constant for the reaction between crystal violet and sodium hydroxide is determined at different temperatures in a batch reactor. Then a tracer experiment is used to characteri...

Development of a new gas sensor for binary mixtures based on the permselectivit...

Membrane-based gas sensors were developed and used for determining the composition on bi-component mixtures in the 0–100% range, such as oxygen/nitrogen and carbon dioxide/methane (biogas). These sensors are low cost and are aimed at a low/medium precision market. The paper describes the use of this sensor for two gas mixtures: carbon dioxide/methane and carbon dioxide/helium. The membranes used are poly(...