• Energy Research

Fat, oil and grease produced by oil/water separation at the wastewater treatment plant of Bari West (Southern Italy) were taken, characterized and converted. After chemical activation of this fatty fraction, with the aim of converting the starting calcium soaps into the respective free fatty acids, a direct esterification was carried out under very mild conditions. Working at 345 K under atmospheric pressure, the thermodynamic conversion (more than 90%) of the free fatty acids into the respective methyl esters was obtained in less than 2 h, by using AlCl3·6H2O as catalyst. Fundamental parameters, such as kinetic and equilibrium constants at different temperatures and activation energy correlated to the use of this catalyst, were also calculated. The biodiesel was purified with a distillation under vacuum, providing a final product conformed to the EN14214 requirements. The convenience of the overall process in terms of costs (0.45 EUR L-1) and specific thermal energy supply (5.02 MJ KgFAMEs-1) make such a process a really sustainable and effective example of valorization of a waste.

Fat, oil and grease produced by oil/water separation at the wastewater treatment plant of Bari West (Southern Italy) were taken, characterized and converted. After chemical activation of this fatty fraction, with the aim of converting the starting calcium soaps into the respective free fatty acids, a direct esterification was carried out under very mild conditions. Working at 345 K under atmospheric pressure, the thermodynamic conversion (more than 90%) of the free fatty acids into the respective methyl esters was obtained in less than 2 h, by using AlCl3·6H2O as catalyst. Fundamental parameters, such as kinetic and equilibrium constants at different temperatures and activation energy correlated to the use of this catalyst, were also calculated. The biodiesel was purified with a distillation under vacuum, providing a final product conformed to the EN14214 requirements. The convenience of the overall process in terms of costs (0.45 EUR L-1) and specific thermal energy supply (5.02 MJ KgFAMEs-1) make such a process a really sustainable and effective example of valorization of a waste.

The Artificial Neural Networks by Multi-objective Genetic Algorithms (ANN-MOGA) model has been applied to gross parameters data of a Sequencing Batch Biofilter Granular Reactor (SBBGR) with the aim of providing an effective tool for predicting the fluctuations coming from touristic pressure. Six independent multivariate models, which were able to predict the dynamics of raw chemical oxygen demand (COD), soluble chemical oxygen demand (CODsol), total suspended solid (TSS), total nitrogen (TN), ammoniacal nitrogen (N-NH4 (+)) and total phosphorus (Ptot), were developed. The ANN-MOGA software application has shown to be suitable for addressing the SBBGR reactor modelling. The R (2) found are very good, with values equal to 0.94, 0.92, 0.88, 0.88, 0.98 and 0.91 for COD, CODsol, N-NH4 (+), TN, Ptot and TSS, respectively. A comparison was made between SBBGR and traditional activated sludge treatment plant modelling. The results showed the better performance of the ANN-MOGA application with respect to a wide selection of scientific literature cases.

The Artificial Neural Networks by Multi-objective Genetic Algorithms (ANN-MOGA) model has been applied to gross parameters data of a Sequencing Batch Biofilter Granular Reactor (SBBGR) with the aim of providing an effective tool for predicting the fluctuations coming from touristic pressure. Six independent multivariate models, which were able to predict the dynamics of raw chemical oxygen demand (COD), soluble chemical oxygen demand (CODsol), total suspended solid (TSS), total nitrogen (TN), ammoniacal nitrogen (N-NH4 (+)) and total phosphorus (Ptot), were developed. The ANN-MOGA software application has shown to be suitable for addressing the SBBGR reactor modelling. The R (2) found are very good, with values equal to 0.94, 0.92, 0.88, 0.88, 0.98 and 0.91 for COD, CODsol, N-NH4 (+), TN, Ptot and TSS, respectively. A comparison was made between SBBGR and traditional activated sludge treatment plant modelling. The results showed the better performance of the ANN-MOGA application with respect to a wide selection of scientific literature cases.

Homogeneous aluminium species, obtained by dissolving AlCl3?6H2O into methanol, were characterised and tested as catalysts into the direct esterification of free fatty acids with methanol. The nature and the role of this catalyst was further investigated through ESI-MS and FTIR spectroscopy, by revealing an immediate exchange reaction between methanol and the water molecules originally bounded to the aluminium, producing a final mixed methanol-aquo-complex whose reactivity was found to be comparable to that of a methanolic solution of hydrogen chloride. Reaction conditions were optimised using the desirability function applied on the response surface methodology analysis of a Box-Behnken factorial design of experiments. By carrying out the reaction at 72?C for 120min and using a catalyst amount of 1.5% (mol of Al respect to fatty acids), almost 94% of the starting acids were converted. At the end of the reaction, a biphasic system was obtained in which the upper methanolic phase, which contained most of the starting catalyst, was separated from the heaviest phase, mainly composed of fatty acid methyl esters. Such a distribution not only allowed the biodiesel to be easily separated, but also the catalysts were efficiently recovered and reused for at least four times, determining a total TON greater than 200, without revealing any loss of its activity. ? 2015 Elsevier B.V.

Homogeneous aluminium species, obtained by dissolving AlCl3?6H2O into methanol, were characterised and tested as catalysts into the direct esterification of free fatty acids with methanol. The nature and the role of this catalyst was further investigated through ESI-MS and FTIR spectroscopy, by revealing an immediate exchange reaction between methanol and the water molecules originally bounded to the aluminium, producing a final mixed methanol-aquo-complex whose reactivity was found to be comparable to that of a methanolic solution of hydrogen chloride. Reaction conditions were optimised using the desirability function applied on the response surface methodology analysis of a Box-Behnken factorial design of experiments. By carrying out the reaction at 72?C for 120min and using a catalyst amount of 1.5% (mol of Al respect to fatty acids), almost 94% of the starting acids were converted. At the end of the reaction, a biphasic system was obtained in which the upper methanolic phase, which contained most of the starting catalyst, was separated from the heaviest phase, mainly composed of fatty acid methyl esters. Such a distribution not only allowed the biodiesel to be easily separated, but also the catalysts were efficiently recovered and reused for at least four times, determining a total TON greater than 200, without revealing any loss of its activity. ? 2015 Elsevier B.V.

Two novel cardiolipin derivatives were recently detected in Halobacterium salinarum, namely an archaeal analog of bisphosphatidylglycerol (BPG) and a glycocardiolipin (GlyC). GlyC was found to be tightly bound to bacteriorhodopsin. To obtain information on the presence and distribution of these archaeal cardiolipins, we have analyzed the lipids extracted from the crystallizer ponds of the salterns of Margherita di Savoia (Italy) and Eilat (Israel) and from cultures of representative species of the Halobacteriaceae by electrospray ionization mass spectrometry. BPG was present as a minor lipid component in the lipids extracted from the biomass of the Margherita di Savoia and the Eilat salterns, while GlyC was detected only in the extract of the biomass of Margherita di Savoia. Both compounds were enriched in the membrane fraction obtained by dialysis of the cells against distilled water. We detected BPG in all members of the Halobacteriaceae tested, but GlyC has so far been found only in the genera Halobacterium and Haloarcula. A sulfated diglycosyl diether was the major glycolipid detected in the biomass of both salterns.

Two novel cardiolipin derivatives were recently detected in Halobacterium salinarum, namely an archaeal analog of bisphosphatidylglycerol (BPG) and a glycocardiolipin (GlyC). GlyC was found to be tightly bound to bacteriorhodopsin. To obtain information on the presence and distribution of these archaeal cardiolipins, we have analyzed the lipids extracted from the crystallizer ponds of the salterns of Margherita di Savoia (Italy) and Eilat (Israel) and from cultures of representative species of the Halobacteriaceae by electrospray ionization mass spectrometry. BPG was present as a minor lipid component in the lipids extracted from the biomass of the Margherita di Savoia and the Eilat salterns, while GlyC was detected only in the extract of the biomass of Margherita di Savoia. Both compounds were enriched in the membrane fraction obtained by dialysis of the cells against distilled water. We detected BPG in all members of the Halobacteriaceae tested, but GlyC has so far been found only in the genera Halobacterium and Haloarcula. A sulfated diglycosyl diether was the major glycolipid detected in the biomass of both salterns.