Many models for accurately predicting the performance of gasket plate heat exchangers were developed in the last decades, grouped in three categories: empirical, semi-analytical or theoretical/numerical, with the view to saving materials and energy through correct design of industrial equipment. This work addresses one such model, namely Lévêque correlation modified by Martin and by Dović, which is promising due to the correct assumption of the flow in sine duct channels and the consideration of energy losses caused by flow reversal at plate edges and the flow path changing when entering the chevron angle. This model was validated by our own experimental data under industrial conditions for vegetable oils processing, both in laminar flow (Re = 8–42) and fully developed turbulent flow (Re = 446–1137). Moreover, in this study, particular values for constants/parameters of the model were determined for the corrugation inclination angle relative to vertical direction equal to 30°. Through statistical analysis, this study demonstrates that this particularized form of the generalized Lévêque correlation can be used with confidence.

This work aims to the recovery of lignocellulosic waste in an environmentally friendly process, as an alternative to the energy-intensive technologies: steam explosion, subcritical and/or supercritical water treatment, gasification through pyrolisis, etc.A study was made to optimize the extraction conditions of potentially valuable compounds in straw degraded by the fungus Pleurotus ostreatus. The effects of solvent nature, temperature and extraction time were quantified by material balances with a special view to the extracts obtained. Confirmation of the effectiveness of the operations was done by spectrophotometric, HPLC and LC-MS analyses.Following this study, a technology localized to the farm was conceived, requiring few craftsmanship and no special utilities, to obtain a semi-product for further processing. A centralized technology could be also taken into account to process the straw by direct extraction with hot solvents, in order to obtain products yields three times higher than in the case of the aqueous extraction followed by solvent extraction at 20 o C.

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The paper has aimed at studying the rheology of macroalgae aqueous suspensions in the presence of cellulase enzyme relevant to bioethanol processing by a subsequent fermentation. Rheological measurements of aqueous suspensions of Ceramium virgatum and Cladophora vagabunda macroalgae species were performed using a Couette geometry rotational viscosimeter. The effects of operation temperature (t=25, 50 �C), cellulase/dried algae ratio (R=0, 16 U/mgda), and algal suspension mass concentration (c=5-15%) on rheological behaviour and parameters were evaluated. Algal suspensions behaved as non-Newtonian fluids obeying either a Bingham plastic linear relationship or an Ostwald-de Waele power law corresponding to a pseudoplastic fluid. Characteristic dynamic viscosity of Bingham plastic fluids were in the range 0.045-0.115 Pa�s for C. virgatum suspensions and 0.021-0.114 Pa�s for C. vagabunda ones, whereas apparent viscosity varied from 0.138 Pa�s to 43.551 Pa�s for C. virgatum and from 0.181 Pa�s to 45.417 Pa�s for C. vagabunda. Data obtained in 8 rheological tests corresponding to a Bingham plastic behaviour of C. vagabunda suspensions, which were processed according to a 23 factorial experiment, emphasized an increase in suspension viscosity with all process factors. The results could be useful for optimization of enzymatic hydrolysis process in order to develop efficient and cost effective saccharification and fermentation strategies.