Recebido em 13/1/04; aceito em 27/1/05; publicado na web em 30/6/05 CONSTRUCTION AND PERFORMANCE STUDIES OF A CPC TYPE PHOTOCHEMICAL REACTOR. A CPC (Compound Parabolic Concentrator) reactor was projected and constructed aiming to promote the degradation of the organic matter present in considerable volumes of aqueous effluents, under the action of solar radiation. The essays were done using a model effluent which consists of a mixture of fragments of a sodium salt of lignosulphonic acid possessing a mean molecular weigth of 52,000 Daltons, and a real effluent, from a chip board industry. The volume of effluent in each test was about 50 L. The tests involved heterogeneous (TiO 2 P25 Degussa and formulations made from the association of TiO 2 with a photosensitiser), and homogeneous (thermal and photochemical Fenton reactions) catalysis of the effluents. The results demonstrate the viability of application of this kind of reactor even when the load of organic pollutants is high.

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-The macadamia tree is known for producing fruit high in fats, enclosed in very hard woody shells. Macadamia nut shell, considered as a by-product from macadamia nut processing, may be a suitable option for pyrolysis. These residues are constituted of cellulose, hemicellulose, lignin and extractives. The Independent Parallel Reaction (IPR) Model has been applied in this work to study the pyrolysis of macadamia nut shell from thermogravimetric experiments. The kinetic parameters and mass fraction of each component were estimated using the Differential Evolution Algorithm. The influence of the model parameters was also analyzed by means of sensitivity studies. The results showed that the decomposition of the macadamia nut shell is more sensitive to the parameters related to the decomposition of lignin. The results of sensitivity analysis also showed that the activation energy affects the total biomass conversion more strongly than the other parameters and the contribution of extractives in the IPR model is as important as the hemicellulose.

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