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481.
Marco Beccali Maurizio Cellura Maria Iudicello Marina Mistretta 《Environmental management》2009,43(4):707-724
Food production and consumption cause significant environmental burdens during the product life cycles. As a result of intensive
development and the changing social attitudes and behaviors in the last century, the agrofood sector is the highest resource
consumer after housing in the EU. This paper is part of an effort to estimate environmental impacts associated with life cycles
of the agrofood chain, such as primary energy consumption, water exploitation, and global warming. Life cycle assessment is
used to investigate the production of the following citrus-based products in Italy: essential oil, natural juice, and concentrated
juice from oranges and lemons. The related process flowcharts, the relevant mass and energy flows, and the key environmental
issues are identified for each product. This paper represents one of the first studies on the environmental impacts from cradle
to gate for citrus products in order to suggest feasible strategies and actions to improve their environmental performance.
相似文献
Marina Mistretta (Corresponding author)Email: |
482.
Hirokazu Sugiyama Ulrich Fischer Elena Antonijuan Volker H. Hoffmann Masahiko Hirao Konrad Hungerbühler 《Process Safety and Environmental Protection》2009,87(6):361-370
We present an investigation on how economic and environmental assessment results change when different process options or evaluation settings are considered. As the main case study the production technology of methyl methacrylate (MMA) is investigated. Six commercial processes using different reaction routes are modelled and evaluated with respect to their economic and environmental performance. On these six base case models different process options and evaluation settings are considered and the resulting impacts on the assessment results are quantified. Major findings of the study are that the more decision-variables become fixed, the smaller becomes the impact of the decisions still to be taken—but not only with respect to the economic performance but also with regard to the environmental assessment result. Along the process development steps the potential impacts on the economic and environmental performance decrease to the same degree. The results obtained for the evaluation settings do not show such a systematic pattern as those for the process options. This finding indicates that decision makers face many options in the economic and especially the environmental assessment of chemical processes which might lead to quite different magnitudes in variability due to either the choice of method or the choice of method parameters. This paper demonstrates that the resulting variability might be crucial with respect to the decision making outcome. 相似文献
483.
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485.
F. R. Funes-Monzote Marta Monzote E. A. Lantinga H. van Keulen 《Environment, Development and Sustainability》2009,11(4):765-783
From the 1960s onwards, a ‘High External Input’ dairy production model was applied widely in Cuba. Overall milk production
of the national herd increased considerably, but the system was inefficient from both a financial and energetic point of view.
In the early 1990s, after the abrupt end of inflow of capital and other resources from Eastern Europe, the dairy sector collapsed.
In the short term, the modern infrastructure of milk production deteriorated and the sector experienced profound vulnerability.
However, in the longer term, this situation stimulated a search for more sustainable approaches, such as low external input
Mixed Farming Systems (MFS). The current study aimed to evaluate two small scale prototype farms to assess the implications
of converting ‘Low External Input’ Dairy Farming Systems into MFS. Fifteen agro-ecological and financial indicators were selected
and monitored over a 6-year period. Two configurations of MFS, i.e. the proportion of the farm area occupied by arable crops,
were tested: 25 and 50%. Productivity, energy efficiency and cost-effectiveness all improved following conversion. Total energy
input was low for both farms and decreased over time, whereas energy efficiency was high and increased over time. Human labour
input was high directly following conversion, but decreased by one-third over the 6-year period. This study demonstrates,
at an experimental scale, the potential of MFS to achieve ecological, productivity and financial advantages for dairy production
in Cuba.
Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue. 相似文献
486.
In this paper we conducted a hypothetical choice experiment in Shanghai, China, to examine whether the China Energy Efficiency Label influences consumers' choices of air conditioners and refrigerators. A latent class approach was applied to observe both heterogeneities among the respondents and product brands. Our results suggested that consumers in Shanghai were well aware of the China Energy Efficiency Label and tended to pay more attention to products with such labels. In addition, air conditioners and refrigerators affixed with a hypothetical label that indicates saving in electricity bills compared with a standard model received significant preferences, which suggested that the more information manufacturers provide, the more their products would be preferred by consumers. Finally, weighted by class probability, the willingness to pay values for more energy efficient refrigerators were higher than those for more energy efficient air conditioners, implying that Shanghai consumers have greater incentive to pay more for appliances they use more frequently. 相似文献
487.
The present paper describes the voluntary greenhouse gas (GHG) reduction agreements of six different industrial sectors in Taiwan, as well as the fluorinated gases (F-gas) reduction agreement of the semiconductor and Liquid Crystal Display (LCD) industries. The operating mechanisms, GHG reduction methods, capital investment, and investment effectiveness are also discussed. A total of 182 plants participated in the voluntary energy saving and GHG reduction in six industrial sectors (iron and steel, petrochemical, cement, paper, synthetic fiber, and textile printing and dyeing), with 5.35 Mt reduction from 2004 to 2008, or 33% higher than the target goal (4.02 Mt). The reduction accounts for 1.6% annual emission or 7.8% during the 5-yr span. The petrochemical industry accounts for 49% of the reduction, followed by the cement sector (21%) and the iron and steel industry (13%). The total investment amounted to approximately USD 716 million, in which, the majority of the investment went to the modification of the manufacturing process (89%). The benefit was valued at around USD 472 million with an average payback period of 1.5 yr. Moreover, related energy saving was achieved through different approaches, e.g., via electricity (iron and steel), steam and oil consumption (petrochemical) and coal usage (cement). The cost for unit CO2 reduction varies per industry, with the steel and iron industrial sector having the highest cost (USD 346 t−1 CO2) compared with the average cost of the six industrial sectors (USD 134 t−1 CO2). For the semiconductor and Thin-Film Transistor LCD industries, F-gas emissions were reduced from approximately 4.1 to about 1.7 Mt CO2-eq, and from 2.2 to about 1.1 Mt CO2-eq, respectively. Incentive mechanisms for participation in GHG reduction are also further discussed. 相似文献
488.
The aim of this study was to verify that in a hot environment, the subjective state could affect cognitive performance before any increase in core temperature. Eighteen volunteers performed a planning (OTS) and a reaction time task in hot and control environments. Before starting the cognitive assessment, subjects completed the Positive and Negative Affect Schedule (PANAS) and provided subjective measures of thermal comfort and thermal sensation. Our results showed that while simple tasks were not affected, complex cognitive task performance was significantly reduced in the HOT. Furthermore, although subjects responded faster during the complex task (OTS) they took longer to find the correct solution. Within the 15 min of heat exposure, skin temperature (Tskin) significantly increased by ∼3 °C. However, core temperature remained unchanged and there were cortical excitability alterations that could have influenced cognitive performance. Therefore, the increase in Tskin appears to be a sufficient physiological response to alter the subjective state of individuals and impair effective decision-making that could have important consequences in occupational settings. 相似文献
489.
M. Al Ali 《International Journal of Green Energy》2016,13(13):1342-1351
In this article, energy and exergy analyses are conducted for two integrated systems which can be used in HVAC applications. These two systems are analyzed for the cases of single generation, cogeneration and trigeneration, and their performances are evaluated through energy and exergy efficiencies. The parametric studies are performed to investigate the effects of using cogeneration and extended to trigeneration on the system performance. To perform the comparisons between the systems for multiple options, the same amounts of outputs (in terms of electricity, heating, cooling) are produced for all systems. The energy analyses of systems 1 and 2 show a great benefit for moving from single generation to trigeneration, with the trigeneration efficiencies of 83.5% and 87.2%, respectively, and single generation efficiencies of 47% for both systems. However, the exergy analyses show that trigeneration may not always become more efficient than single generation, particularly for system 1, due to the fact that the trigeneration exergy efficiency is 38.7% and the corresponding single generation efficiency is 44.3%. For system 2, the trigeneration exergy efficiency is 52.7% while the single generation efficiency becomes 44.3%. Depending on the type of cogeneration or cogeneration design, the system can be more efficient. 相似文献
490.
M. Rajagopal 《International Journal of Green Energy》2016,13(11):1109-1119
A phase change material (PCM)-based flat plate modular heat exchanger for free cooling application, suitable for the diurnal temperature variation that prevails during the summer months of Bangalore city, India is designed and experimentally investigated. The flow and other parameters selected in the present study are meant to suit the accelerated charging of the PCM in the modular heat exchanger during the early morning hours, and to provide cool energy to the room during the daytime, by circulating the ambient air through the heat exchanger at a lower velocity. It is observed from the charging experiments that the decrease in the inlet air temperature has more influence in reducing the solidification time than the increase in the inlet air velocity. The heat exchanger designed in the present investigation is capable of maintaining the room temperature around 30°C for a longer duration of 8 hr when the heat load is 0.5 kW. It is suggested to design the modular heat exchanger with a surface area proportionate to the present heat exchanger size when the room heat load increases beyond 0.5 kW, in order to maintain a minimum comfortable temperature of 30°C in the room. 相似文献