Development of impact assessment methodologies for environmental sustainability

Despite years of discussion on the merits of sustainability, there is still no consensus on how to determine if environmental sustainability is achieved or even if progress is made. The Brundtland Commission statement that sustainability “meets the needs of the present without compromising the ability of future generations to meet their own needs (World Commission on Environment and Development, Our common future, Oxford University Press, New York, 1987)” establishes the long-term focus of sustainability goals. Impact categories, such as land and water use, that can cause large spatial and long-temporal scale impacts are important for sustainability assessments, and may require detailed spatial analysis to capture all the important input parameters. Environmental sustainability impact assessments can use life cycle impact assessment methodologies, but can also be supplemented with impact assessments conducted from a variety of perspectives. Having this flexibility of perspective can allow more detailed site-specific assessments that may represent unsustainable situations. While it is necessary to provide decision support with a comprehensive assessment, aggregation of impact categories has the disadvantage of obscuring the individual vulnerabilities of each impact category, which can be critically important to the overall sustainability picture. An outline of a sustainability assessment case study focused on biomass-based alternatives required under the renewable fuel standard will be provided to demonstrate a more comprehensive view of sustainability.     

Avoiding sustainability trade-offs in environmental assessment

Progress towards sustainability requires positive steps to meet all of the interdependent core requirements for sustainability – including biophysical system integrity and basic human well-being. Where these essentials are involved trade-offs should be avoided, unless all other options are worse. In environmental assessments, it is useful to identify major trade-offs and minimize them through selection of less bad alternatives or addition of mitigations or offsets. However, the more promising approach starts earlier and encourages planning that avoids invidious trade-offs, including through re-consideration of the initial purposes and alternatives.

This paper considers two historical cases of assessments that avoided significant trade-offs through processes that gave mandatory attention to purposes and alternatives, covered the full suite of sustainability considerations, empowered citizen participants and facilitated the bumping of cases up to a more strategic level where broader alternatives offered better trade-off avoidance. These long-advocated assessment design elements are still rarely applied as a full package in existing environmental assessment law and practice. Commitment to trade-off avoidance adds to the reasons for their general adoption.     

Combined pinch and exergy analysis of an ethylene oxide production process to boost energy efficiency toward environmental sustainability

Ethylene oxide production process is one of the highest energy consumers in chemical industry, and therefore even a slight improvement in its overall efficiency can have a significant impact on the sustainability of the process. Efficiency improvement can be carried out using the exergy-aided pinch analysis outlined in this paper. The overall exergy loss distribution in different unit operations of an ethylene oxide process was first evaluated and mapped out in the form of “visualized exergetic process flowsheet”. An initial analysis of the four main functional blocks of the process showed that the exothermic reaction block contained the largest exergy loss (6043 and 428 kJ/kg of internal and external losses, respectively) which can be reduced by isothermal mixing, as well as increasing reaction temperature and reduction in pressure drop. The absorption block was also estimated to have the second highest contribution with total exergy losses of 3640 kJ/kg which were mainly due to the cooling column. These losses were then recommended to be reduced by improvements in the concentration and temperature gradients along the tower. Following the block-wise analysis, exergy analysis was then carried out for individual unit operations in each block to pinpoint the main sources of thermal exergetic inefficiency. Thermal solutions to reduce losses were also proposed in accordance with the identified sources of inefficiency, leading to a comprehensive list of cold and hot process streams that could be introduced to reduce losses. Finally, pinch analysis was brought into action to estimate the minimum energy requirements, to select utilities, and to design heat exchanger network. Thus, the methodology used in this work took advantage of both exergy and pinch analyses. The combined thermal-exergy-based pinch approach helped to set energy targets so that all the thermal possible solutions supported by exergy analysis were considered, preventing exclusion of any hot or cold process stream with high potential for heat integration during pinch analysis. Results indicated that the minimum cold utility requirement could be reduced from 601.64 MW (obtained via conventional pinch analysis) to 577.82 MW through screening of streams by the combined methodology.     

Material research for environmental sustainability in Thailand: current trends

This article covers recent developments of material research in Thailand with a focus on environmental sustainability. Data on Thailand’s consumption and economic growth are briefly discussed to present a relevant snapshot of its economy. A selection of research work is classified into three topics, namely, (a) resource utilization, (b) material engineering and manufacturing, and (c) life cycle efficiency. Material technologies have been developed and implemented to reduce the consumption of materials, energy, and other valuable resources, thus reducing the burden we place on our ecological system. At the same time, product life cycle study allows us to understand the extent of the environmental impact we impart to our planet.     

Material research for environmental sustainability in Thailand: current trends

Abstract

This article covers recent developments of material research in Thailand with a focus on environmental sustainability. Data on Thailand’s consumption and economic growth are briefly discussed to present a relevant snapshot of its economy. A selection of research work is classified into three topics, namely, (a) resource utilization, (b) material engineering and manufacturing, and (c) life cycle efficiency. Material technologies have been developed and implemented to reduce the consumption of materials, energy, and other valuable resources, thus reducing the burden we place on our ecological system. At the same time, product life cycle study allows us to understand the extent of the environmental impact we impart to our planet.     

Analyzing interrelationships among environmental sustainability innovation factors

Clean Technologies and Environmental Policy - Due to growing public awareness, governmental regulations and concerns, environmental sustainability initiatives have received increasing attention...     

Urban regeneration and impact assessment for social sustainability

This paper provides a working definition of social sustainability and highlights the growing array of social sustainability assessment tools (e.g. SIA, HIA, equality impact assessment, SA). Within EIA the social dimension has been very much the ‘poor relation’. However, changes in the UK planning system, the drive for sustainable communities, and for greater public involvement in decision making are raising the profile of the social dimension. This is particularly relevant for urban regeneration projects, which are often mixed use (including housing), and with the potential for development to be shaped by community involvement. The paper includes a review of recent environmental statements (ESs) for regeneration projects in the UK, which provides findings on, for example, the inclusion of social factors in the process; scope of such factors; methodological approaches and impact assessment tools; and role of community involvement. The research raises questions about the extent to which social issues shape outcomes; it also highlights some important challenges, including the key issue of ‘integration versus disintegration’ in the scope and process of impact assessment.     

Sustainable supply chains for supply chain sustainability: impact of sustainability efforts on supply chain risk

Supply chain managers across the globe are finding it difficult to manage the increasingly complex supply chains despite adopting a variety of risk mitigation strategies. Firms on the other hand have also been adopting various kinds of environmental and social sustainability practices in recent times to reduce carbon footprint and improve their image on the social front. However, very few studies in the extant literature have examined the impact of sustainability practices on supply chain risk. We address this important gap in literature by empirically testing this relationship, using primary data from six manufacturing sectors and 21 different countries including developed as well as emerging markets across the globe. Our findings indicate that risk mitigation strategies do not always reduce the actual supply chain risk experienced by firms, whereas sustainability efforts help reduce supply chain risk, especially in emerging market contexts. In addition, we find that, while reactive risk mitigation strategies on their own fail to reduce supply chain risk, they are effective when used in conjunction with sustainability efforts. We also find that preventive risk mitigation efforts are only effective in mature supply chains such as the OECD countries.     

Energy absorption efficiency of carbon fiber reinforced polymer laminates under high velocity impact

In this paper, response of carbon fiber reinforced polymer (CFRP) laminates subjected to high velocity impact has been investigated by experimental and numerical methods. Experiments using a two-stage light gas gun were conducted to investigate the impact process and to validate the finite element model. The energy absorption efficiency (EAE) of CFRP laminates with different thickness was investigated. According to the results of experiments and numerical calculations, thin CFRP laminates have a good EAE under relative higher velocity impact; by contraries, a superior EAE is displayed in thick laminates under relative lower velocity impact. Subsequently, EAE of CFRP laminates was compared with that of 304 stainless-steel plates. In a specific impact velocity range, EAE of CFRP laminates is higher than that of 304 stainless-steel. Thus, CFRP laminates have a potential advantage to substitute the metal plates to be used in high velocity impact resistance structures under a specific impact velocity range.     

The quality of environmental impact statements and environmental impact assessment practice in Bangladesh

This paper investigates the quality of environmental impact statements (EISs) and gives us an understanding about the performance of environmental impact assessment (EIA) practice in Bangladesh. EIA has been formally practised in Bangladesh since 1995.However, no study has yet been conducted on the quality of EISs. This study fills this gap. This empirical study shows that the quality of EISs in Bangladesh is ‘just satisfactory’ only. A significant proportion of EISs (34%) are still unsatisfactory. Finally, possible factors affecting the quality of EISs are examined and measures to improve the quality of EISs are recommended. The findings will be useful to EIA practitioners and other stakeholders in Bangladesh. This study will also provide a general guideline for other developing countries with similar socio-economic context.     

Production of green energy from co-digestion: perspectives for the Province of Cuneo, energetic balance and environmental sustainability

In Italy and many European countries, energy production from biomass is encouraged by strong economic subsidies so that biomass energy plants are getting large diffusion. Nevertheless, it is necessary to define the environmental compatibility taking into account global parameters as well as environmental impacts at regional and local scales coming from new polluting emissions. The environmental balances regarding new energy plants are of primary importance within very polluted areas such as Northern Italy where air quality limits are systematically exceeded, in particular for PM₁₀, NO₂, and ozone. The paper analyzes the renewable energy scenario relating to manure anaerobic digestion and biogas production for the Province of Cuneo, N–W Italy, and the environmental sustainability of the possible choices. The study is focused on energy producibility, heat and power, nitrogen oxides and ammonia emissions, GHG (greenhouse gases) balances dealing also with indirect releases of CH₄ and N₂O, as well as emissions due to energy crops production. The most important conclusion that can be drawn is that the production of renewable energy from anaerobic digestion could cover up to 13 % of the Province electricity consumption, but sustainability in terms of CO₂ emissions can be reached only through an overriding use of agricultural waste products (manure and by-products instead of energy crops) and cogeneration of thermal energy at disposal; the application of the best available techniques to waste gas cleaning, energy recovery, and digestate chemical–physical treatments allows positive emissive balances.     

Evaluating the environmental friendliness, economics and energy efficiency of chemical processes: heat integration

The design and improvement of chemical processes can be very challenging. The earlier energy conservation, process economics and environmental aspects are incorporated into the process development, the easier and less expensive it is to alter the process design. In this work different process design alternatives with increasing levels of energy integration are considered in combination with evaluations of the process economics and potential environmental impacts. The example studied is the hydrodealkylation (HDA) of toluene to produce benzene. This study examines the possible fugitive and open emissions from the HDA process, evaluates the potential environmental impacts and the process economics considering different process design alternatives. Results of this work show that there are tradeoffs in the evaluation of potential environmental impacts. As the level of energy integration increases process fugitive emissions increase while energy generation impacts decrease. Similar tradeoffs occur for economic evaluations, where the capital and operating costs associated with heat integration could be optimised. From the example designs considered here, an intermediate amount of energy integration produces the most economically beneficial and environmentally friendly process.     

Energy, economic, and environmental analysis of the Malaysian industrial compressed-air systems

Compressed-air systems account for about 10% of the total industrial-energy use in Malaysia and some other countries. Compressed air is typically one of the most expensive utilities in an industrial facility. Opportunities for potential savings can thus be sought and identified. This article estimates the energy used by compressed-air systems in Malaysian industries. Various energy-saving measures, such as use of high efficient motors, variable speed drive (VSD), leak prevention, use of outside intake air, reducing pressure drop, recovering waste heat, and use of efficient nozzle, were applied to save compressed-air energy and then the results were compared with available literatures. For an electric motor used in a compressed air system, a sizeable amount of electric energy and utility bill have been found to be saveable using high efficient motors and applying VSDs in matching the speed requirements. Also, significant amounts of energy and emission are reducible through various energy-saving strategies. Payback periods for different energy saving measures have been estimated and found to be economically viable in most cases.