Heterogeneous Catalysts: Design, Applications and Research Insights

The cyclization of pseudoionone yields a mixture of alpha-ionone, beta-ionone and gamma-ionone. By careful control of reagent and reaction conditions, either the alpha- and beta- isomer can be favoured. The alpha-ionone has violet odour and is widely used in perfumery and flavours. beta-Ionone is the main precursor of Vitamin A and beta-carotene. Traditionally, strong homogeneous catalysts, like sulphuric acid and phosphoric acid have been used. These problems can be overcome by the use of solid acid catalysts. This work reports the cyclization of pseudoionone over USY zeolites, at 80ºC. USY It is observed that the initial activity increases with the Si/Al ratio of zeolite until a maximum, which is obtained with USY3. With higher Si/Al ratio, a decrease in the catalytic activity is observed. Selectivity to ionone isomers is around 42 %, at 75% of pseudoionone conversion, after 24 h of reaction. USY3 zeolite was reused four times with the same catalyst sample in the same condicions. It was observed a stabilization of the catalytic activity, after the second use.

Design of an Efficient Hybrid System for Electricity Production with Supervisory Control

This chapter aims to develop a new method for the economical evaluation of Hybrid Systems for electricity production. The different types of renewable sources are specifically evaluated in the economical performance of the overall equipment. The presented methodology was applied to evaluate the design of a photovoltaic-wind-diesel hybrid system to produce electricity for a community in the neighbourhood of Luanda, Angola. Once the hybrid generator is selected, it is proposed to provide the system with a supervisory control strategy to maximize its operating efficiency.