Terms Of Global Warming Potential Research Articles

Massive timber building vs. conventional masonry building. A comparative life cycle assessment of an Italian case study

This work aims to investigate the environmental friendliness of building materials, and in particular the benefit of using biogenic products as replacement of conventional materials. The sustainability of wood as a construction material is a complex issue since the environmental impacts are strongly related to forest management, service life and, finally, to end-of-life scenarios and waste treatment processes. In this study, a Life Cycle Assessment (LCA) comparison was carried out between a semi-detached house out of cross-laminated timber (CLT) and a conventional building with similar geometric characteristics and equal thermal performance (U-value), out of light-clay bricks with a reinforced concrete structure. Particularly, the environmental impacts from raw materials supply, transportation and product processing (cradle to gate) were investigated and the Recipe mid-point method was adopted for the impact assessment to compare the environmental burdens of the two equivalent buildings. The positive environmental values resulted in the massive timber building are mainly connected to the replacement of the reinforced concrete mass used in the structure. The outcome, in terms of global warming potential, show that the use of wood as a building material instead of conventional materials results in a reduction of greenhouse gas emissions of roughly 25%. This material replacement, if extended on a large scale, could give a valid contribution on achieving the community goals of reducing emissions from the construction sector.

A comparative life-cycle assessment of hydro-, nuclear and wind power: A China study

Energy sector is one of biggest contributors to the Greenhouse Gas (GHG) emissions. As a result, it has attracted considerable attention to reduce the GHG emissions of electricity production. Hydro-electric, nuclear and wind power are the top three clean energy in China. In this study, the environmental impacts of these three technologies are analyzed, assessed and compared via a life-cycle assessment approach. The entire life cycle, including the manufacturing, construction, operation and decommissioning stages is examined. Apart from global warming potential (GWP100) caused by GHG emissions, the environmental impacts assessed in this study also included acidification potential (AP), eutrophication potential (EP), photochemical ozone creation potential (POCP) and human toxicity potential (HTP). The results show that wind power technology has the most significant environmental impacts amongst these three clean energies, followed by nuclear power and hydropower. For example, in terms of global warming potential, wind power produces 28.6 ± 3.2 g CO2-eq/kWh of GWP100 throughout its life cycle, which is higher than that of nuclear power (12.4 ± 1.5 g CO2-eq/kWh) and hydropower (3.5 ± 0.4 g CO2-eq/kWh). In addition, this study revealed that the the manufacturing stage is the largest contributor of environmental impacts for wind and hydropower. By contrast, the decommissioning stage is most significant for nuclear power in terms of environmental impacts. The comparative life cycle assessment method proposed in this study provides useful tool for the future environmental assessment of electricity production technologies. Findings of this study provide useful inputs for the sustainable transformation of the energy sector.

Integrated municipal solid waste management scheme of Hong Kong: A comprehensive analysis in terms of global warming potential and energy use

The climate and energy nexus have drawn global attention towards sustainable solutions for synthetic processes, such as waste management. Innovative policies can amend waste management systems to be more sustainable, as in Hong Kong, where besides the conventional landfilling, alternatives like incineration and biological treatment methods are being considered to develop an integrated system. However, the outcomes appear uncertain and need to be analysed for best possible integration. This study proposes a customized methodology for impact assessment of these waste treatment technologies and evaluates five integrated scenarios in terms of net greenhouse gas emissions (GHEs) and energy use by applying classified modelling approaches. The baseline results revealed that compared to the landfilling alone, integration of landfilling with combined anaerobic digestion and composting (ADC) reduced up to 56% of net GHEs. Incineration with ADC saved up to 87% GHEs and ranked as the best-case scenario in both impact categories. Considering carbon sequestration as a credit suggested that landfill-linked scenarios were suitable for GHEs saving, while landfilling alone remained the worst case. The uncertainty propagation and sensitivity analysis revealed that some key parameters can alter the ranking order of scenarios, when variated by the reported uncertainty. The study provides useful modelling insights into the critical nature of these technologies and can be considered as a decision-making tool locally, as well as a generic calculation template.

Conversion of organic resources by black soldier fly larvae: Legislation, efficiency and environmental impact

To meet the projected substantial growth in the global demand for meat, we are challenged to develop additional protein-rich feed ingredients while minimizing the use of natural resources. The larvae of the black soldier fly (BSF) have the capacity to convert low-value organic resources into a high quality protein source for pigs, chickens and fish and as such may increase both the productivity and the efficiency of the food chain. The aim of this study was to assess the environmental opportunities of BSF larvae reared on different sources using up to date literature data on the efficiency of BSF larvae in converting such resources into biomass. The current EU legislative framework was used to classify the various resources for rearing insects. Data of forty articles published until 1 September 2017 were used, reporting on in total 78 (mixtures of) resources used for growing BSF larvae. Data on the resource conversion efficiency on dry matter (DM) and N basis was presented in 11 and 5 studies, evaluating 21 and 13 resources, respectively. Resources studied included food and feed materials (A, n = 8 resources), foods not intended (anymore) for human consumption (B1, n = 4), and residual streams such as food waste (D, n = 2), and animal manure (E, n = 7). Conversion efficiency varied from 1.3 to 32.8% for DM and from 7.4 to 74.8% for N. Using life cycle assessment, our environmental results showed that resources within the legal groups (i.e. A and B1) that are, at the moment, not allowed in EU as animal feed have in general a lower impact in terms of global warming potential, energy use, and land use. On a per kg protein basis, BSF larvae reared on a resource that contains food (e.g. sorghum) and feed (e.g. dried distillers grains with solubles) products generally have higher environmental impacts than conventional feed protein sources (fishmeal and soybean meal). Using insects as feed, therefore, has potential to lower the environmental impact of food production but a careful examination of the resource is needed in terms of environmental impact, safety and economics.

Enhancements in phytoremediation technology: Environmental assessment including different options of biomass disposal and comparison with a consolidated approach

Phytoremediation represents a solution for treating soils contaminated by heavy metals, provided that appropriate plant species are selected and the proper strategy chosen. When dealing with soil contaminated with arsenic and/or lead, which are non-essential elements for plants but also among the most toxic metals, this task is particularly difficult to achieve. In a previous contribution we showed that metals accumulation by Lupinus albus, Brassica juncea and Helianthus annuus can be improved by dosing suitable chemicals (i.e. phosphate and EDTA), leading to a quicker and cheaper intervention.This study discusses the assisted phytoremediation of a real site contaminated by several metals, presenting an environmental assessment realized by using the GaBi LCA software. The environmental sustainability of the reclamation technology was analyzed in terms of Global Warming Potential (GWP-100 years), considering different destinations for the harvested biomass, and comparing its ecological footprint with the outcomes of a conventional treatment of excavation and landfill disposal.The comparison clearly shows the great advantage of the phytoremediation, in terms of environmental impact, highlighting the importance of correctly handling the disposal of contaminated biomass produced. In fact, its incineration (aimed at reducing the volumes to be disposed of) could be more onerous than a direct landfilling, but re-qualify as a more sustainable choice if combined with energy recovery. The same applies to fast pyrolysis, which seems to be the most sustainable approach to date, at least in terms of technological maturity, although this requires technical-economic considerations on the quality and use of biofuels produced.

CARBON FOOTPRINT OF WASTE MANAGEMENT IN ROMANIA IN THE CONTEXT OF CIRCULAR ECONOMY

The shift from a linear economy to the circular economy emerges as a solution to save natural resources and to decrease the effects of the climate change on the environment. Understanding the role of the waste as secondary resource and recovering it can reduce the consumption of non-renewable primary resources, the consumption of energy in the production processes and can also lower the CO2 emissions. The study aims at evaluating the environmental impact when applying the principles of the circular economy in the solid waste management and the possible savings in terms of global warming potential (CO2 eq.) in Romania. The evaluation is done with help of Life Cycle Assessment (LCA) approach on a case study in Timisoara. The study demonstrates that savings of over 40.000 t CO2 -eq. per year would be possible in a city with 300.000 inhabitants. The concept can be applied (with appropriate adjustments) also in other cities from Romania or from other countries, making possible the implementation of circular economy.

Sustainability assessment for different design solutions within the automotive field

Sustainability is a critical issue for the automotive industry, making that car manufacturers have to address also environmental issues additionally to the traditional ones. Within this context, many research and industry activities have been concentrated in the field of lightweighting through the development of innovative materials and manufacturing technologies.This study deals with the sustainability assessment of two alternative design solutions for a door demonstrator module: a reference steel-based door structure is compared to a re-engineered variant which is mainly constituted of state-of-the art aluminum. Environmental impact, energy consumption and cost are chosen as sustainability pillars and the results are expressed respectively in terms of Global Warming Potential (kg CO2 eq), Primary Energy Demand (MJ) and total cost (Euro). The analysis follows a cradle-to-gate approach, capturing the contributions due to raw materials extraction, component manufacturing and operation; the use stage is evaluated for both Internal Combustion Engine Vehicle (ICEV) and Electric Vehicle (EV) variants. The inventory for energy and impact assessment is mainly based on primary data directly measured on process site.The overall profile of the different design solutions is assessed and the main, environmental, energy and cost life-cycle hotspots are identified and critically discussed. The dependence of indicators on life-cycle mileage is investigated for both ICEV and EV case studies by means of the break-even point analysis. Finally, the effective convenience of reference and lightweight alternatives is evaluated considering the overall set of sustainability aspects through a multi-criteria decision analysis.

A radiative forcing analysis of tropical peatlands before and after their conversion to agricultural plantations.

The tropical peat swamp forests of South-East Asia are being rapidly converted to agricultural plantations of oil palm and Acacia creating a significant global "hot-spot" for CO2 emissions. However, the effect of this major perturbation has yet to be quantified in terms of global warming potential (GWP) and the Earth's radiative budget. We used a GWP analysis and an impulse-response model of radiative forcing to quantify the climate forcing of this shift from a long-term carbon sink to a net source of greenhouse gases (CO2 and CH4 ). In the GWP analysis, five tropical peatlands were sinks in terms of their CO2 equivalent fluxes while they remained undisturbed. However, their drainage and conversion to oil palm and Acacia plantations produced a dramatic shift to very strong net CO2 -equivalent sources. The induced losses of peat carbon are ~20× greater than the natural CO2 sequestration rates. In contrast, a radiative forcing model indicates that the magnitude of this shift from a net cooling to warming effect is ultimately related to the size of an individual peatland's carbon pool. The continuous accumulation of carbon in pristine tropical peatlands produced a progressively negative radiative forcing (i.e., cooling) that ranged from -2.1 to -6.7nW/m2 per hectare peatland by 2010 CE, referenced to zero at the time of peat initiation. Peatland conversion to plantations leads to an immediate shift from negative to positive trend in radiative forcing (i.e., warming). If drainage persists, peak warming ranges from +3.3 to +8.7nW/m2 per hectare of drained peatland. More importantly, this net warming impact on the Earth's radiation budget will persist for centuries to millennia after all the peat has been oxidized to CO2 . This previously unreported and undesirable impact on the Earth's radiative balance provides a scientific rationale for conserving tropical peatlands in their pristine state.

Analysis of Production System Components of Container-grown Chrysanthemum for Their Impact on Carbon Footprint and Variable Costs Using Life Cycle Assessment

Life cycle assessment (LCA) was used to analyze the production system components of a 20-cm Chrysanthemum grown for the fall market in the north Atlanta region of the United States. The model system consisted of 2 weeks of mist in a greenhouse followed by 9 weeks on an outdoor gravel bed equipped with drip irrigation. The carbon footprint, or global warming potential (GWP), was calculated as 0.555 kg CO2e and the variable costs incurred during the modeled production system (from rooting purchased cuttings to loading the truck for shipment) totaled $0.846. Use of plastics was important in terms of GWP and variable costs with the container contributing 26.7% of the GWP of the product and 12.2% of the variable costs. The substrate accounted for 44.8% of the GWP in this model but only 12.1% of the variable costs. Consumptive water use during misting was determined to be 3.9 L per plant whereas water use during outdoor production was 34.8 L. Because propagation is handled in various ways by Chrysanthemum growers, the potential impact of alternative propagation scenarios on GWP and variable costs, including the purchase of plugs, was also examined.

Impacts of feedlot floor condition, deposition frequency, and inhibitors on N2O and CH4 emissions from feedlot dung and urine patches

ABSTRACTPatches of dung and urine are major contributors to the feedlot gas emissions. This study investigated the impacts of dung deposition frequency (partly reflecting animal stocking density of a feedlot), dairy feedlot floor conditions (old floor indicated with the presence of consolidated manure pad [CMP] vs. new floor with the absence of consolidated manure pad [CMPn]), and application of dicyandiamide (DCD) and hydroquinone (HQ) on nitrous oxide (N2O) and methane (CH4) emissions from patches in the laboratory, and the integrative impacts were expressed in terms of global warming potential (CO2-equivalent). Dung deposition frequency, feedlot floor condition, and application of inhibitors showed inverse impacts on N2O and CH4 emissions from patches. Greenhouse gas (GHG) emissions from the dung, urine, and dung+urine patches on the CMP feedlot surface were approximately 7.48, 87.35, and 7.10 times those on the CMPn feedlot surface (P < 0.05). Meanwhile, GHG emissions from CMP and CMPn feedlot surfaces under high deposition frequency condition were approximately 10 and 1.7 times those under low-frequency condition. Moreover, application of HQ slightly reduced the GHG emission from urine patches, by 14.9% (P > 0.05), while applying DCD or DCD+HQ significantly reduced the GHG, by 60.3% and 65.0%, respectively (P < 0.05). Overall, it is necessary to include feedlot management such as animal stocking density and feedlot floor condition to the process of determining emission factors for feedlots. In the future, field measurements to quantitatively evaluate the relative contribution of nitrification and denitrification to the N2O emissions of feedlot surfaces are highly required for effective N2O control.Implications: This study shows that feedlot CH4 and N2O emissions inversely respond to the dicyandiamide (DCD) application. Applying DCD significantly reduces GHG emissions of feedlot urine patches. Feedlot floor condition and stocking density strongly impact feedlot GHG emissions. Including feedlot floor condition and stocking density in the feedlot EF determining process is necessary.

Investigating the feasibility of a reuse scenario for textile fibres recovered from end-of-life tyres

The management of end-of-life tyres (ELTs) is regulated by several national and international legislations aiming to promote the recovery of materials and energy from this waste. The three main materials used in tyres are considered: rubber (main product), which is currently reused in other closed-loop applications; steel, which is used for the production of virgin materials; and textile fibres (approximately 10% by weight of ELTs), which are mainly incinerated for energy recovery (open-loop scenario).This study aims to propose and validate a new closed-loop scenario for textile fibres based on material reuse for bituminous conglomerates. The final objective is to verify the technical, environmental, financial, and economic feasibility of the proposed treatment process and reuse scenario. After characterization of the textile material, which is required to determine the technological feasibility, a specific process has been developed to clean, compact, and prepare the fibres for subsequent reuse. A life cycle assessment (LCA) has been carried out to quantify the environmental benefits of reusing the fibres. Finally, a cost benefit analysis based on the LCA results was conducted to establish the long-term financial and economic sustainability.From a technological point of view, the tyre textile fibres could be a promising substitute to the reinforcement cellulose commonly used in asphalts as long as the fibres are properly prepared (compaction and pellet production) for application in the standard bituminous conglomerate production process. From an environmental point of view, relevant benefits in terms of global warming potential and acidification potential reduction were observed in comparison with the standard incineration for energy recovery (respectively −86% and −45%). Moreover, the proposed scenario can be considered as financially viable in the medium to long term (cumulative generated cash flow is positive after the 5th year) and economically sustainable (expected net present value of more than €3,000,000 and economic rate of return of approximately 30%). Finally, the sensitivity and risk analyses show that no specific issues are foreseen for the future implementation in real industrial applications.

Life-cycle assessment of bioethanol production from sweet sorghum stalks cultivated in the state of Yucatan, Mexico

Bioethanol is being promoted in Mexico to be used in a blend with gasoline. On the north of the Yucatan peninsula, bioethanol could be produced from sweet sorghum, as it can grow efficiently on this land; it can be harvested 2–3 times in a year and possesses a better agronomical stability than sugarcane with low nitrogen requirements and high productivity. In this work , the potential environmental impacts and energy efficiency of bioethanol production from sweet sorghum were evaluated using life-cycle assessment. Four scenarios were evaluated: scenario PI considered only bioethanol production from the stalk juice; scenarios PII and PIII added cogeneration from the dry-stalk biomass in single and combined cycle, respectively. Scenario PIV considered bioethanol production from both stalk juice and dry-stalk biomass. Scenario PI demanded more fossil energy than what was generated as bioethanol, while scenarios PII and PIII were fossil energy independent. Scenario PIII showed the higher net energy ratio (1.89) and a better environmental performance in all CML-IA baseline impact categories. In terms of global warming potential, the scenario PIII showed a mitigation potential of 16% with respect to the fossil reference. In the categories where the sweet sorghum scenarios represented larger emissions than the fossil reference, it was due mainly to the use of fertilizers and the conventional energy consumption in the various processing steps of the biomass. Scenario PIV showed the highest energy demand and worst environmental performance due to large demands of energy and chemicals in the bagasse pretreatment step.

Reuse scenarios of tires textile fibers: an environmental evaluation

End of Life Tires (ELT) constitute a major portion of End of life Vehicles (ELV). The treatment process of ELTs is primarily aimed at recovering steel and rubber, which jointly represent the main portion of the ELT material and are currently applied in different sectors. During the treatment of ELTs, other sub-products are generated in significant quantities (about 10-15% in weight), as textile fibers that currently are landfilled or used for energy recovery. The aim of this study is a comparative evaluation of the environmental impacts related to three different end of life scenarios for the textile fibers. In addition to landfilling and incineration, this study considers the possibility to reuse textile fibers as reinforcement in bituminous conglomerates. Results obtained through the Life Cycle Assessment study confirms that the reuse scenario leads to a relevant reduction of impacts in terms of Global Warming Potential. However, by considering other environmental metrics the reuse scenario is not always the less impactful one.

Environmental impacts along intensity gradients in Norwegian dairy production as evaluated by life cycle assessments

The aim of the study was to explore whether and how intensification would contribute to more environmentally friendly dairy production in Norway. Three typical farms were envisaged, representing intensive production strategies with regard to milk yield both per cow and per hectare in the three most important regions for dairy production in Norway. The scores on six impact categories for produced milk and meat were compared with corresponding scores obtained with a medium production intensity at a base case farm. Further, six scenario farms were derived from the base case. They were either intensified or made more extensive with regard to management practices that were likely to be varied and implemented under northern temperate conditions. The practices covered the proportion and composition of concentrates in animal diets and the production and feeding of forages with different energy concentration. Processes from cradle to farm gate were incorporated in the assessments, including on-farm activities, capital goods, machinery and production inputs. Compared to milk produced in a base case with an annual yield of 7250kg energy corrected milk (ECM) per cow, milk from farms with yields of 9000kg ECM or higher, scored better in terms of global warming potential (GWP). The milk from intensive farms scored more favourably also for terrestrial acidification (TA), fossil depletion (FD) and freshwater eutrophication (FE). However, this was not in all cases directly related to animal yield, but rather to lower burden from forage production. Production of high yields of energy-rich forage contributed substantially to the better scores on farms with higher-yielding animals. The ranking of farms according to score on agricultural land occupation (ALO) depended upon assumptions set for land use in the production of concentrate ingredients. When the Ecoinvent procedure of weighting according to the length of the cropping period was applied, milk and meat produced on diets with a high proportion of concentrates, scored better than milk and meat based on a diet dominated by forages. With regards to terrestrial ecotoxicity (TE), the score was mainly a function of the amount of concentrates fed per functional unit produced, and not of animal yield per se. Overall, the results indicated that an intensification of dairy production by means of higher yields per animal would contribute to more environment-friendly production. For GWP this was also the case when higher yields per head also resulted in higher milk yields and higher N inputs per area of land.

LCA perspective to assess the environmental impact of a novel PCM-based cold storage unit for the civil air conditioning

Cold storage is a valid solution for the energy peak reduction in the air conditioning field, which strongly affects the energy consumption in the civil sector. An innovative storage device, called ColdPeak, has been already tested in a recently published work, demonstrating unparalleled properties in terms of charging/discharging storage power. Now, the unit is analyzed from the environmental point of view by means of a LCA (Life Cycle Assessment) methodology: the air conditioning system integrating the ColdPeak unit has been compared with a conventional system from the environmental point of view, assuming the same potentiality of cold energy and including a sensitive analysis on the energy saving potential of the innovative device (5–25% of the energy required by the conventional system). In the sensitivity analysis, the energy saving is counter-balanced by the energy load required for the manufacturing and installation of an additional component in the air conditioning system (the ColdPeak device itself).The environmental footprint that considers the material and the energy to fabricate the ColdPeak is very low if compared with the amount of energy saved thanks to its application. As a matter of fact, the LCA study reports that the integration of the cold storage unit allows a significant reduction of environmental footprint in terms of Global Warming Potential (−17%), Acidification Potential (−15.5%), Eutrophication Potential (−18%), Eco-toxicity (−16%), Human Health (−18%) and Fossil Depletion (−18%). The paper also reports the temporal trend of the environmental footprint that shows a pay-back period for the construction of the innovative integrated system of less than one year for all the investigated categories.

Toward a Sustainable Impeller Production: Environmental Impact Comparison of Different Impeller Manufacturing Methods

SummaryImpellers are the core components of turbomachinery in petrochemical and aeronautical engineering. In addition to conventional manufacturing (CM), additive manufacturing (AM) and remanufacturing (RM) can also be used in impeller production. This article presents a life cycle assessment method comparing the environmental impacts of different impeller manufacturing methods, including plunge milling (CM), laser cladding forming (AM combined with CM), and additive remanufacturing (RM). Results show that RM is the most environmentally favorable option, followed by AM and CM, in terms of global warming potential (GWP), Chinese resource depletion potential (CADP), water eutrophication potential (EP), and acidification potential. However, AM is not always more environmentally friendly than CM. The comparison of impeller production by CM and pure AM, in this case, indicates that the environmental burden of production using pure AM is approximately twice than that of CM. Compared with CM, the RM of impellers would reduce GWP, CADP, and EP by 64.7%, 66.1%, and 75.4%, respectively. The results of this study contribute to a scientific basis for the selection of manufacturing methods and the sustainable manufacturing of impeller production enterprises.

Life cycle assessment of waste-to-energy (WtE) technologies for electricity generation using municipal solid waste in Nigeria

In this paper, life cycle assessment (LCA) of waste to energy (WtE) treatment plants for electricity generation in twelve selected cities of Nigeria is studied with the aim of evaluating their electricity generation potential, global warming potential (GWP), acidification potential (AP) and dioxin/furan emission potential. The WtE plants are: landfill gas to energy (LFGTE), hybrid of incineration and anaerobic digestion (INC/AD) and hybrid of incineration and landfill gas to energy (INC/LFGTE). The benefits of the WtE plants are thereafter compared to the landfilling (waste management without intention of energy recovery) in each of the locations in order to determine the option that best fit the locations in an environmentally sustainable manner. To achieve this, the waste profile of each of the locations is determined using per capita waste generation and the population data obtained from national population commission (NPC). Some of the key results reveal that the hybrid of INC/AD is potentially viable compared to other methods in terms of GWP and ecosystem potential measured by AP. However, LFGTE technology is the best in terms of carcinogenic reduction potential measured by dioxin/furan emissions. The hybrid of INC/AD has the potential of reducing GWP in the range of 75.7–93.3% compared to land filling without energy recovery. Similarly, hybrid of INC/LFGTE provided a reduction in the range of 75.3–84.8% while LFGTE could reduce the GWP by 75%. This paper could serve as a source of scientific information for decision making on environmental sustainability in waste-to-energy projects in Nigeria.

Sewage sludge as fertiliser - environmental assessment of storage and land application options.

Sewage sludge (SS) contains beneficial plant nutrients and organic matter, and therefore application of SS on agricultural land helps close nutrient loops. However, spreading operations are restricted to certain seasons and hence the SS needs to be stored. Storage and land application of SS are both potential sources of greenhouse gases and ammonia, leading to global warming, acidification and eutrophication. Covering the stored SS, treating it with urea and choosing the correct time for land application all have the potential to reduce emissions from the system. Using life cycle assessment (LCA), this study compares storage and land application options of SS in terms of global warming potential (GWP), acidification potential, eutrophication potential and primary energy use. The system with covered storage has the lowest impact of all categories. Systems with autumn application are preferable to spring application for all impact categories but, when nitrate leaching is considered, spring application is preferable in terms of eutrophication and primary energy use and, for some SS treatments, GWP. Ammonia addition reduces nitrous oxide and ammonia emissions during storage, but increases these emissions after land application. Storage duration has a large impact on GWP, while amount of chemical nitrogen fertiliser substituted has a large impact on primary energy use.

Environmental Impact Assessment of a School Building in Iceland Using LCA-Including the Effect of Long Distance Transport of Materials

Buildings are the key components of urban areas and society as a complex system. A life cycle assessment was applied to estimate the environmental impacts of the resources applied in the building envelope, floor slabs, and interior walls of the Vættaskóli-Engi building in Reykjavik, Iceland. The scope of this study included four modules of extraction and transportation of raw material to the manufacturing site, production of the construction materials, and transport to the building site, as described in the standard EN 15804. The total environmental effects of the school building in terms of global warming potential, ozone depletion potential, human toxicity, acidification, and eutrophication were calculated. The total global warming potential impact was equal to 255 kg of CO2 eq/sqm, which was low compared to previous studies and was due to the limited system boundary of the current study. The effect of long-distance overseas transport of materials was noticeable in terms of acidification (25%) and eutrophication (31%) while it was negligible in other impact groups. The results also concluded that producing the cement in Iceland caused less environmental impact in all five impact categories compared to the case in which the cement was imported from Germany. The major contribution of this work is that the environmental impacts of different plans for domestic production or import of construction materials to Iceland can be precisely assessed in order to identify effective measures to move towards a sustainable built environment in Iceland, and also to provide consistent insights for stakeholders.

Environmental impact of food waste bioconversion by insects: Application of Life Cycle Assessment to process using Hermetia illucens

Food waste management strategies are mainly focused on waste minimization, but the search for new solutions to waste valorization is also a viable and potentially advantageous alternative. In this context, the aim of this study is to assess the potential environmental impacts of food-waste bioconversion into compost and dried larvae through the action of Hermetia illucens, by applying Life Cycle Assessment (LCA). In international scientific literature, there are many studies concerning the utilization of insects for food-waste bioconversion, but very few articles relate to the application of LCA in this sector and none of these refers to Hermetia illucens. Furthermore, the process of bioconversion through Hermetia illucens is a very attractive option, considering that it represents a potential valuable solution to two problems: food waste management on the one hand and, on the other, the rising global demand for feed (dried larvae can be used in aquaculture feed production) or the competition between land use for energy crops and for food crops (dried larvae are a fat-rich resource potentially usable for the production of biodiesel). In particular, the LCA results presented in this study refer to the assessment of the potential environmental impacts of a pilot plant in which H. illucens is employed for food-waste treatment. From 10 tonnes of food-waste input, 300 kg of dried larvae and 3,346 kg of compost are produced. Three different functional units were used to carry out the analysis: the input of the production process, therefore 1) food-waste; the output composed of dried larvae, for which 2) the protein content (fundamental characteristic for using this product in aquaculture) and 3) the lipid content (to be used for biodiesel production) are considered. Results related to the functional unit of 1 tonne of food waste treated show a value of 30.2 kg CO2 eq in terms of Global Warming Potential, 215.3 MJ in terms of Energy Use, and 0.661 m2a in terms of Land Use. When compared with alternative sources of raw material for feed or biodiesel, these results show that the most significant benefits of insect production are connected to Land Use, while Energy Use is the main burden, and the estimation of Global Warming Potential is still affected by many uncertainties.