Power generation from slaughterhouse waste materials : an emergy accounting assessment

Unidad de excelencia María de Maeztu MdM-2015-0552The linear path "extraction-production-consumption-waste", imposed by humans to natural ecosystems, where all material flows are instead circular, has become unsustainable. Understanding the potential value of some of these "by-products", in order to exploit them effectively in a biorefinery perspective, may help overcoming resource shortages and decrease environmental impacts. This study investigates energy and resource restoration from animal by-products. The slaughterhouse waste undergoes a rendering process to separate residual meal and fat. The latter is combusted in a co-generation plant to produce electricity and heat. The process is carefully assessed using Emergy Accounting approach with the aim of evaluating benefits and environmental load of the process considering the advantages achieved compared with the demand for ecosystem services and natural capital depletion. Moreover, the case aims at exploring three different methodological assumptions referring to the upstream burdens carried by the waste management system, proposing a modified exergy-based allocation rule. The electricity generated shows performances in terms of Unit Emergy Values ranging between 2.7E+05 sej/J, 2.2E+06 sej/J and 3.1E+07 sej/J among the different cases investigated, comparable to power from fossil fuels and renewables sources, and it provides an environmentally sound alternative to conventional waste disposal

Halophytes as components of lawns under different soil salinity and human impact in the health resort “Ciechocinek”

The comparison was performed on the flora of lawns located in the vicinity of three brine concentration towers in the Spa Park in the town of Ciechocinek. It was found that a different level of saline water inflow into the soil and a different use of these lawns are the main causes of the observed differences in the number and the species composition of halophytes and glycophytes. The possibility of determining the differences in the intensity of human impact on the studied systems was discussed, as well as the value of the Environmental Sustainability Index was determined through emergy analysis. Energy flow diagrams were prepared for two basic greenery management methods and salt production, which best differentiates the flora of the studied lawns

Resource use and biophysical constraints of Scottish agriculture

Agriculture is a fundamental sector of economy and society that ensures food supply, classified by the Millennium Ecosystem Assessment among the so-called “provisioning ecosystem services”. Due to the increase of food demand worldwide, farmers are shifting more and more towards intensive agriculture. This trend is connected to the unsustainable consumption of natural resources, most often exceeding the carrying capacity of natural ecosystems. In this paper, the resource use and biophysical constraints of Scottish agriculture were investigated at regional and national levels by means of the Emergy Synthesis method. The study focused on two main agroecosystems: 1) the Cairngorms National Park (CNP) and 2) the national agricultural sector of Scotland as a whole. The evolution of the agricultural sector was explored over time (years 1991, 2001, 2007), accounting for local renewable and non-renewable resources as well as imported resources. Performance and sustainability indicators were then calculated with and without including human labor and economic services (money flows). In the year 2007, the Emergy Yield Ratio (EYR) of the Scottish agricultural sector was about 46% of the same indicator calculated for the CNP (2.65 versus 5.72, respectively). A higher Environmental Loading Ratio (ELR) was calculated for the national sector than for CNP (1.25 versus 1.02, respectively). The Emergy Sustainability Index (ESI) was 2.12 for the national sector and 5.60 for CNP. Such figures were calculated without including the emergy flows supporting labor and services. If the latter are also accounted for, the ESI of the national level and CNP drop by a factor 5.6 and 3.9, respectively. Such variations suggest that larger flows of non-renewable resources strongly affect the environmental performance, increasing the dependence on non-renewable resources supporting the larger economic system in which the agricultural sectors are embedded in

Estimating the environmental impact of textiles : multimethod environmental assessment of textile products and processing

Conferència sobre la petjada ecològica dels teixits, a càrrec de Maddalena Ripa i Silvio Viglia de la parthenope University, dins el marc del 7th International Seminar on Sustainable Technology Development: Sustainable Clothing: Production and Consumption que es va dur a terme del 9 al 20 de juny de 2014.Conferència sobre la petjada ecològica dels teixits, a càrrec de Maddalena Ripa i Silvio Viglia de la parthenope University, dins el marc del 7th International Seminar on Sustainable Technology Development: Sustainable Clothing: Production and Consumption que es va dur a terme del 9 al 20 de juny de 2014

Indicators of environmental loading and sustainability of urban systems. An emergy-based environmental footprint

Cities are the engine of economic development and human wellbeing, but their dynamics needs to be supported by the convergence of large flows of material and energy resources. Assessing a city resource metabolism becomes increasingly crucial, not only concerning the relation with the environment as a source or a sink, but also concerning the internal dynamics of resource exchange among city components and sectors. We applied Emergy Accounting (EMA) and Cumulative Energy Demand (CED) methods to develop and validate indicators of urban environmental sustainability, using as case studies five urban systems of different size in Italy. CED allowed an assessment of the commercial energy consumption required on local and global scales to support the city life and economy. Airborne emissions related to direct and indirect energy consumption were also assessed. EMA was used to quantify the environmental support required for the urban metabolism, in terms of resource generation and ecosystem services supply. Combining these three aspects, a new metric is discussed and developed to estimate the environmental impact of cities, with reference to their resource use, in order to implement comprehensive indicators and suggest resource use criteria at urban level. A city's support area to buffer upstream and downstream environmental loading is also calculated. Relative and absolute sustainability concepts are introduced and discussed, showing how far the investigated cities are from a resource-based environmentally sustainable state. Finally, practices are suggested as an exit strategy from the present intensive fossil powered economy towards a higher level of environmental sustainability and wellbeing