Cinzia Buratti

Biogas production from different substrates in an experimental Continuously Stirred Tank Reactor anaerobic digester.

Different mixtures were digested in a single-stage, batch, mixed, laboratory scale mesophilic anaerobic digester at the Biomass Research Centre Laboratory (University of Perugia). The yield and the composition of biogas from the different substrates were evaluated and the cumulative curves were estimated. Two experimental campaigns were carried out, the first on three mixtures (chicken, pig and bovine manures), the second on animal and vegetal biomasses (chicken and cow manure, olive husk) with different inocula (rumen fluid and digested sludge). In the first campaign pig manure mixture showed the maximum biogas production (0.35 N m(3)/kg) and energy content (1.35 kWh/kg VS); in the second one the differences in produced biogas from the different inocula were analyzed: olive husk with piggery manure anaerobically digested as inoculum showed the higher biogas (0.28 N m(3)/kg VS) and methane yield (0.11 N m(3)/kg VS), corresponding to an energetic content of 1.07 kWh/kg VS. All data obtained from the laboratory scale anaerobic digester are comparable to the values in literature for several biomass and in particular for olive husk, dairy manure and chicken manure.

Anaerobic digestion of mechanically treated OFMSW: Experimental data on biogas/methane production and residues characterization

One of the more promising processes for the energetic transformation of waste is the anaerobic digestion of the Organic Fraction of Municipal Solid Waste (OFMSW). An experimental campaign was carried out on three different samples of OFMSW from Waste Separation (WS), one as received and two obtained after mechanical treatment (squeezing): OFMSW slurry (liquid fraction) and OFMSW Waste (residual solid fraction). Anaerobic Biogasification Potential (ABP) and anaerobic digestion tests (AD) were carried out, investigating the effects of inoculum and pH. The OFMSW Waste was also examined to evaluate the possibility to dispose of it in a landfill. Results showed that OFMSW slurry must be diluted and inoculated and that pH control in the start up phase is essential, in order to have significant biogas productions. OFMSW as received did not show a significant biogas production, while OFMSW Waste showed suitable characteristics for landfill disposal, except for Dissolved Organic Carbon.

Lighting and Energetic Characteristics of Transparent Insulating Materials: Experimental Data and Calculation

This paper reports the study of thermal and optical properties of innovative transparent insulating materials (TIM) for glazing systems: silica aerogel (pane and granular) and capillary geometric media. Twenty-one samples were assembled with several kinds of glasses in various combinations with TIM. Transmission and reflection coefficients versus wavelength were measured and the results were elaborated in compliance with UNI EN 410/2000. The better performance was given by the monolithic aerogel both for light transmittance (0.58 in interspace between two 4mm float glasses) and thermal insulation (U = 0.63 W • m— 2 • K—1). The solar factor was 0.70. The performance of the innovative glazing systems was compared with data related to windows normally used in Italy and in EU countries, in order to comply with the limits of the local normative standard required for thermal transmittance. The results showed a very promising behaviour of TIMs, in fact a 60% reduction in heat losses with respect to a double glazing with a low-e layer was achieved, with only a 27% reduction in light transmittance. For the granular systems, a U-value little higher than 1 W • m—2 • K—1 with the same total thickness was obtained, even if the light reduction was about 66%.

Thermogravimetric analysis of the behavior of sub-bituminous coal and cellulosic ethanol residue during co-combustion.

The influence of the addition of cellulosic ethanol residue (CER) on the combustion of Indonesian sub-bituminous coal was analyzed by non isothermal thermo-gravimetric analysis (TGA). The effect of blends ratio (5%, 10%, 15% and 20%), interaction mechanism, and heating rate (5°C/min, 10°C/min, 15°C/min, 20°C/min) on the combustion process was studied. The results show that the increase of the blending ratio allows to achieve the increase of the combustibility index from 7.49E-08 to 5.26E-07 at the blending ratio of 20%. Two types of non-isothermal kinetic analysis methods (Ozawa-Flynn-Wall and Vyazovkin) were also applied. Results indicate that the activation energy of the blends decreases with increasing the conversion rate. In particular, the blending ratio of 20% confirms to have the better combustion performance, with the average value of the activation energy equal to 41.10 kJ/mol obtained by Ozawa-Flynn-Wall model and 31.17 kJ/mol obtained by Vyazovkin model.

Indoor noise reduction index with open window

Indoor noise is mainlycaused byroad and railwaytraffic, especiallyin summer time due to open windows. The presence of absorbent ceilings can help to reduce reverberating noise and the global mean acoustic level. The aim of this work is to define an index to evaluate the indoor noise reduction index (NRI) with open window; it is a function of the acoustic absorption coefficient of the room ceiling. It is evaluated bymeasurements in two reverberating rooms, which simulate the real conditions. In the emission room a noise source reproduces the road and railwaynoise. In the receiving room a microphone measures the noise level and its spectrum; the ceiling is treated with different absorption materials. A comparison between the values in absence and in presence of different materials and an evaluation of NRI are carried out. Experimental results are generalised and a theoretical expression of NRI is given. # 2002 Elsevier Science Ltd. All rights reserved.

Silica nanogel for energy-efficient windows

Abstract: This chapter discusses the utilization of silica nanogel to develop high energy-efficient windows and skylights. Silica aerogels are firstly discussed in terms of chemical structure, production process, and physical, mechanical, and thermal properties. The chapter then reviews their current applications in buildings as thermal and acoustic insulation materials. Finally, the potential of the nanogel windows for energy saving in buildings and the main future research trends are discussed.

Thermal behaviour and kinetic study of the olive oil production chain residues and their mixtures during co-combustion.

The kinetic behaviour of olive tree pruning (PR), two- (2PH) and three-phase (3PH) olive pomace and their blends was investigated under combustion condition using thermogravimetric analysis. PR was blended with 2PH and 3PH at different ratios (25:75, 50:50 and 75:25) and tested in the temperature range from ambient to 1000°C in order to evaluate the co-combustion behaviour. Results showed that the thermal degradation of all samples can be divided into three regions (drying, devolatilisation, char oxidation) with different combustion properties, depending on the percentage of PR. Significant interaction was detected between the fuels, and reactivity of 2PH and 3PH was improved upon blending with PR. The iso-conversional methods, Ozawa-Flynn-Wall and Vyazovkin, were employed for the kinetic analysis of the oxidation process. The results revealed that the activation energy of PR was higher than the one of 2PH and 3PH, and the minimum value was obtained for 25PR752PH sample.

Aerogel Plasters for Building Energy Efficiency

Nowadays in many countries, the building sector is the largest energy consumer and one of the best ways to reduce energy demand of buildings is the reduction in heat losses through the envelope. In this scenario, insulating materials with aerogels have growing interest and new applications such as insulating aerogel-based renderings are in development. This chapter deals with the analysis of superinsulating applications for building envelope such as aerogel-incorporated concrete- and aerogel-based renders. After an overall analysis of the market trend for these innovative systems, the rendering compositions, the physics, thermal, acoustic, and hygrothermal properties of aerogel-based renders are discussed. In situ applications of the new developed render are analyzed and the potential of the investigated materials is highlighted, by considering experimental measurements in Sect. 2.4. Finally, a comparison with traditional solutions and the future trends are considered.

Nanogel Windows for Energy Building Efficiency

The chapter deals with the potential of highly energy-efficient windows with silica aerogel for energy saving in buildings. Aerogel is a low-density nanostructured porous material with very low thermal conductivity (about 0.018 W/m K for translucent granular aerogel at room temperature) and excellent acoustic insulation. It is ideal for energy saving in buildings, also due to its good optical transparency. The characteristics of the raw material (silica aerogel for windows: monolithic and translucent granular) are illustrated with general information about the production process, the main chemical and physical properties, and a market overview; then, nanogel windows are discussed and thermal, visual, and acoustic performance are highlighted. A useful worldwide market overview about the commercial products and the main manufactures is also included. Finally, a state-of-the-art review of nanogel windows in building applications is discussed: the potential of the investigated solutions is described by both experimental results and simulation models of the aerogel windows performance, referring to different case studies. Future research, market trends, and costs are also discussed.

Thermal degradation of driftwood: Determination of the concentration of sodium, calcium, magnesium, chlorine and sulfur containing compounds

The annual production of driftwood in Italy has been estimated to be more than 60,000 tonnes. This wood can be used as an energy source. Particular attention should be paid to its content of alkali and alkaline earth metals, sulfur and chlorine. Few works are available in the literature on this topic. For this reason, the authors propose experimental tests of combustion, gasification and pyrolysis, to evaluate the fate of alkali and alkaline earth metals, sulfur and chlorine in the solid residues and compare the three thermal degradation technologies. The results show a release of alkaline earth metals of about 45% of the initial quantity for gasification and a release of 55% of the initial quantity for combustion (while pyrolysis at 600°C has a very low release). The release of sodium is about 65% for gasification and 80% for combustion. It can be seen that the release of sodium is higher than that of alkaline earth metals; this is due to the divalency of the last ones. Dealing with the release of major elements (chlorine, sulfur and AAEMs) the tests have shown that pyrolysis process is a low emitting technology.