Sustainability in energy production

The requirement of energy in different human activities is continuously increasing; from the energetic production, chiefly by thermal systems, important and worrying environmental problems are generated: there are concerns about climate change, local air quality worsening, exhaustion of resources and land use change. To limit these negative aspects, policies of reduction in energy use must be first proposed; besides different technological, economic and planning solutions can be considered; their effect must be carefully assessed, as concerns effectiveness and practical implementation. The final political decision must consider the different tools that are at disposal, in order to define the best approach for the satisfaction of necessities with the minimum consequent impact

Technical and environmental comparison among different municipal solid waste management scenarios

In order to determine the optimal final destination of municipal solid waste, it is necessary to consider both monetary costs and environmental externalities, as well as the local availability of waste-processing industrial infrastructure. The paper examines the results obtained from a technical, economic, and environmental comparison between different scenarios for waste management: in particular, the solutions of gasification and pyrolysis were studied and, afterwards, were compared with direct combustion in incineration plant (from the point of view of the thermal treatment) and final disposal in landfill. In order to perform this analysis, 19 plants operating on full scale were analyzed. The comparison took into account environmental, energy, and economic aspects. From the environmental and energetical point of view, the tool of mass and energy balance was used to address some key environmental aspects. In particular, some indexes were defined in order to perform a comparison among the different analyzed solutions. As concerns the economic point of view, conventional economic criteria were considered. The analysis showed advantages for the examined thermal treatment solutions. The comparison methodology that has been defined can establish a more general useful approach in order to help the definition of the best solution for waste management planning

Environmental balance study for the construction of a biomass plant in a small town in Piedmont (Northern Italy)

In consideration of local critical aspects in opposition to overall environmental benefits (decrease of GHG generation), the aim of this work is to verify the local acceptability from the point of view of air quality of the territory in question for a biomass plant. The plant to be realized in a small town located in Piedmont, Northern Italy, will be constructed to produce electricity and heat. In order to verify the aspect of compatibility we performed an evaluation of the emissive flow modification that in the hypothesis of the biomass plant activation should be introduced in the municipal area. The evaluation has been conducted by using mass and energy balances as a tool. © 2011 WIT Press

Sustainability in energy production

The requirement of energy in different human activities is continuously increasing; from the energetic production, chiefly by thermal systems, important and worrying environmental problems are generated: there are concerns about climate change, local air quality worsening, exhaustion of resources and land use change. To limit these negative aspects, policies of reduction in energy use must be first proposed; besides different technological, economic and planning solutions can be considered; their effect must be carefully assessed, as concerns effectiveness and practical implementation. The final political decision must consider the different tools that are at disposal, in order to define the best approach for the satisfaction of necessities with the minimum consequent impact

Analysis of the emergent climate change mitigation technologies

A climate change mitigation refers to efforts to reduce or prevent emission of greenhouse gases. Mitigation can mean using new technologies and renewable energies, making older equipment more energy efficient, or changing management practices or consumer behavior. The mitigation technologies are able to reduce or absorb the greenhouse gases (GHG) and, in particular, the CO2 present in the atmosphere. The CO2 is a persistent atmospheric gas. It seems increasingly likely that concentrations of CO2 and other greenhouse gases in the atmosphere will overshoot the 450 ppm CO2 target, widely seen as the upper limit of concentrations consistent with limiting the increase in global mean temperature from pre-industrial levels to around 2◦C. In order to stay well below to the 2◦C temperature thus compared to the pre-industrial level as required to the Paris Agreement it is necessary that in the future we will obtain a low (or better zero) emissions and it is also necessary that we will absorb a quantity of CO2 from the atmosphere, by 2070, equal to 10 Gt/y. In order to obtain this last point, so in order to absorb an amount of CO2 equal to about 10 Gt/y, it is necessary the implementation of the negative emission technologies. The negative emission technologies are technologies able to absorb the CO2 from the atmosphere. The aim of this work is to perform a detailed overview of the main mitigation technologies possibilities currently developed and, in particular, an analysis of an emergent negative emission technology: the microalgae massive cultivation for CO2 biofixation

Economic viability and greenhouse gas (GHG) budget of the biomethane retrofit of manure-operated biogas plants: A case study from Piedmont, Italy

The management of livestock manures and slurries noticeably improved since the massive introduction of anaerobic digestion (AD) plants in Italy and other European Union (EU) countries. However, these plants heavily rely on incentives, and the recent switch of European biogas policies from electricity to biomethane potentially threatens the economic viability of manure AD. In this study, three retrofit options are analyzed for an installation in Piedmont (NW Italy) that is currently producing 999 kWel through combined heat and power (CHP). The techno-economic feasibility and the greenhouse gas (GHG) budget is analyzed for each solution. Results show that exploiting current incentives on electricity is vital to fund the retrofit of CHP plants to biomethane. Energy crop and electricity prices, the sale price of biomethane certificates after the end of incentives, and biogas productivity are the critical parameters for the economic profitability of manure AD plants, along with the possibility to deliver biomethane directly to the pipeline grid. This study provides insight to the reconversion of manure AD plants, addressing issues that affect hundreds of installations in Italy and other EU countries

VARIABILITY of EMISSION RATE DEFINITION in REGULATORY ODOUR DISPERSION MODELLING from CIVIL WASTEWATER TREATMENT PLANTS

The analysis of odour impacts in civil wastewater treatment plants (WWTPs) is a challenging task. Odour regulations still present a lack of standardization, that bring inherent levels of uncertainty to the analysis procedure. Dispersion models can provide support towards the characterization and reduction of odour nuisances. The application of dispersion models requires an adapt setting and a detailed characterization of the emission sources, in terms of emission rate. In this study odour dispersion of a large WWTP in northern Italy was considered. Simulations were carried out with the CALPUFF model. The study focused on the selection of the open field correction method for wind velocity used in the calculation of odour emission rates (OERs). Three different relationships were considered: the power law, the logarithmic law and the Deaves–Harris (D–H) law. The area underlying the 1 OU/m3, 3 OU/m3, and 5 OU/m3 concentration isopleths was considered as indicator. The results showed that OERs and impact area varied depending on the selected method. Taking the power law as the reference, the average variability of the impact area was between –33% and –48% if the logarithmic law was applied, and –83% and –94% if the D–H law was applied. The present study provides knowledge towards a better alignment of the concept of the odour impact criteria