Abstract:The effects of increasing concentrations of oregano (Origanum vulgare L.) and rosemary (Rosmarinus officinalis L.) essentials oil (EO) on ruminal gas emissions were tested in vitro using 50 mL serum bottles. Each bottle contained a 200 mg substrate (alfalfa hay and corn meal 1:1) and a 20 mL solution composed of a buffered medium and rumen fluid (1:2). The percentage of ruminal fermentation products was quantified by an infrared analyzer. The reduction of total gas production was 6% and 9% respectively when using the 1.5 and 2.0 g/L oregano EO measurements. The reduction of methane production was 55%, 72% and 71% respectively with regard to the 1.0, 1.5 and 2.0 g/L oregano EO doses, while rosemary EO (2.0 g/L) reduced the methane production by 9%. The production of ammonia was significantly reduced (59%-78%) by all treatments with the exception of OPEN ACCESSSustainability 2015, 7 12857 rosemary EO at the lowest dose. Dry matter and neutral detergent fiber degradability was reduced by most of the treatments (respectively 4%-9% and 8%-24%). The total volatile fatty acids (VFA) concentration was markedly decreased by oregano EO and was not affected by rosemary EO. Both EOs mitigated rumen fermentations, but oregano EO gave rise to the highest reduction in methane and ammonia production. However, further research is needed to evaluate the use of these essential oils as dietary supplements by taking into account the negative effects on feed degradability.

Abstract:The Biomass Research Centre, section of CIRIAF, has recently developed a biomass boiler (300 kW thermal powered), fed by the poultry manure collected in a nearby livestock. All the thermal requirements of the livestock will be covered by the heat produced by gas combustion in the gasifier boiler. Within the activities carried out by the research project ENERPOLL (Energy Valorization of Poultry Manure in a Thermal Power Plant), funded by the Italian Ministry of Agriculture and Forestry, this paper aims at studying an upgrade version of the existing thermal plant, investigating and analyzing the possible applications for electricity production recovering the exceeding thermal energy. A comparison of Organic Rankine Cycle turbines and Stirling engines, to produce electricity from gasified poultry waste, is proposed, evaluating technical and economic parameters, considering actual incentives on renewable produced electricity.

Space conditioning is responsible for the majority of carbon dioxide emission and fossil fuel consumption during a building’s life cycle. The exploitation of renewable energy sources, together with efficiency enhancement, is the most promising solution. An innovative layout for ground-source heat pumps, featuring upstream thermal energy storage (uTES), was already proposed and proved to be as effective as conventional systems while requiring lower impact geothermal installations thanks to its ability to decouple ground and heat-pump energy fluxes. This work presents further improvements to the layout, obtained using more compact and efficient thermal energy storage containing phase-change materials (PCMs). The switch from sensible- to latent-heat storage has the twofold benefit of dramatically reducing the volume of storage (by a factor of approximately 10) and increasing the coefficient of performance of the heat pump. During the daily cycle, the PCMs are continuously melted/solidified, however, the average storage temperature remains approximately constant, allowing the heat pump to operate closer to its maximum efficiency. A life cycle assessment (LCA) was performed to study the environmental benefits of introducing PCM-uTES during the entire life cycle of the system in a comparative approach.

An innovative space-conditioning system is proposed and a life-cycle assessment (LCA) is presented. The layout is obtained starting from a ground-source heat pump system (GSHP) and includes upstream thermal storage (TS). A prototype of the system, implemented following this new approach, is currently in use for space heating and cooling of an industrial building. As a result of the TS designed to decouple the geothermal side from the heat-pump side, the system is able to provide the required thermal energy to the building with a reduced-size geothermal installation (i.e., shorter/fewer boreholes (BHs)). The performance was monitored for over 2 years, both in cooling and heating modes. A LCA study of this system is performed on the basis of specific data for implementation and operation phases. The results are given in terms of the comprehensive ReCiPe midpoint and endpoint indicator suite and are compared with literature studies of other conventional technologies for space conditioning.

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