Comparative LCA Study Research Articles

To what extent do geopolitical conditions affect the environmental sustainability of the circular economy? A comparative LCA study of lactic acid production in Denmark and Iran

Transitioning to a circular economy is inevitable in well-developed and developing economies. Biowaste valorization into value-added products has shown a promising sustainable solution compared to its fossil-based counterparts. However, it has yet to be scientifically analyzed to what extent geopolitical conditions affect the environmental sustainability of the circular economy. To fill this gap, we conducted a consequential life cycle assessment of biorefining biowaste into lactic acid and bioenergy in Denmark and Iran as representative examples of developed and developing economies, respectively. Despite the notable environmental impacts associated with fossil-based energy consumption and infrastructural limitations, Iran could benefit more environmentally from the suggested biorefinery by 2030 than Denmark. This contrast arises from the fact that the existing dominant waste management solution in Iran consists of sanitized and unsanitized landfills, which appear likely to continue through 2030. Therefore, any alternative waste management scenario would help avoid the environmental impacts arising from landfills. In contrast, Denmark already has a well-established and sustainable waste management practice for biowaste, namely anaerobic digestion. Accordingly, the environmental impacts of the investigated scenarios in Denmark were, on average, 85 %, 855 %, 177 %, and 130 % higher than those in Iran regarding resource scarcity, ecosystem quality, human health, and climate change, respectively. In both countries, incineration, the culture medium, ion exchange, vacuum distillation, transportation, emissions from digestate applications on farmlands, and the inorganic waste landfilling process (only applied to IR scenarios) contributed most to the overall environmental impacts. Besides impacts arising from geopolitical conditions, our study revealed that abiotic augmentation and P. acidilactici bioaugmentation demonstrated superior environmental performance compared to other methods. The results also highlight the importance of international collaboration to implement circular economy approaches in developing countries and accelerating global environmental mitigation efforts. To comprehensively evaluate the environmental sustainability of circular bioeconomy, it is recommended to examine scenarios aligned with socio-economic pathways and various representative concentration pathways.

Sustainable synthesis of levulinic acid using waste derived silica-alumina-hydroxyapatite supported nano ZrO2 photo-acidic catalyst under synergistic UV-FIR irradiations

A novel nano-photocatalyst has been prepared using hydroxyapatite (HAp) derived from waste fish scale and fly ash-derived aluminosilicate (SiO2-Al2O3) grafted with zirconium oxide (ZrO2) active sites by innovative photo-hydrothermal protocol. The physiochemical properties of the prepared photocatalyst have been characterized by different analyses like TGA, XRD, FTIR, XPS, UV–VIS–NIR, BET, NH3-TPD, HRTEM, and DLS. The optimal catalyst has a zirconium loading of 20 wt% and has a low bandgap energy of 2.15 eV as confirmed by UV–VIS–NIR spectroscopy. The optimal catalyst also depicted a high acidity of 1.52 mmol NH3/g and a specific surface area of 62.872 m²/g. Owing to the high acidity, specific surface area, and low band gap energy the photocatalyst has led to achieving an elevated yield of 76.6% levulinic acid (LA) from glucose in hybrid irradiation reactor (HIR) deploying UV and FIR radiations at appreciably low temperature and reaction time of 115 ℃ and 2 h respectively. Under the same reaction conditions, the conventionally heated reactor (CHR) gave a very low yield of 23.7%. Individual radiation effects on LA yield evinced the synergistic advantageous effect of the hybrid irradiation technique. The catalyst reusability and regenerative study confirmed the high stability of the prepared catalyst. Also, a comparative LCA study has been conducted between HIR and CHR systems which revealed that HIR was more environmentally sustainable than CHR. HIR -based process demonstrated a reduction in 59% global warming potential, 70.66% forest resource scarcity, and 65% lower terrestrial ecotoxicity while being 120% more energy efficient than CHR-based reaction making HIR more environmentally sustainable as well as economically feasible.

Ex-ante life cycle assessment of FineFuture flotation technology: case study of Grecian Magnesite

PurposeThis study aims at evaluating the environmental performance of a novel froth flotation technology in mining industry from a life cycle perspective. The technology is being developed under EU Horizon 2020 project titled “FineFuture” (FF) with the aim of saving valuable materials in fine particles that are currently wasted due to lack of technology.MethodsFF relies on chemically enhancing the physical characteristics of particles allowing it to float and concentrate.Prospective life cycle assessment (pLCA) was conducted for two possible industrial applications of FF flotation technology in the case study of Grecian Magnesite (GM) which is a main magnesium oxide producer in Europe. Each application can be perceived as a standalone comparative LCA study comparing current system with future system incorporating FF technology on industrial scale.Results and discussionThe future scenarios did not decisively support FF technology in neither of the two applications from an environmental point of view. When applied to fines of < 4 mm granular size with the aim of material recovery, the future scenario performed better than the current situation only in 5 out of 16 impact categories. The main issue is the added burden of calcination phase. When the technology was tested to upgrade the existing magnesite concentrate before calcination, it introduced some gains in most of the impact categories, but the difference compared to the current situation is not very considerable. Testing improved scenarios showed a great benefit to the overall performance of the scenarios by introducing cleaner fuels and burners in calcination phase.Conclusion and recommendationsOverall, the results tend to favour applying FF technology to upgrade low quality concentrates rather than beneficiating < 4 mm fines. However, and in any case, if FF technology is to be applied, combining it with cleaner fuels and burners in calcination should be prioritized. Furthermore, it was found that improving the purity (i.e. quality) in the flotation tank output is a key factor from an environmental view. The results also showed little impact of the added electric energy demand from the new units. As any pLCA, the study has limitations mainly originating from the low technology readiness level (TRL) when data collection activities were carried out. Further studies should start from pilot-scale data and adopting more accurate upscaling approaches to calculate the impacts of a full industrial deployment of the technology.

Data implementation matters: Effect of software choice and LCI database evolution on a comparative LCA study of permanent magnets

AbstractLife cycle assessment (LCA) databases and software evolve. We analyzed to which extent software and evolving life cycle inventory databases affect the comparison of technology alternatives, using a comparative LCA on permanent magnets as a case study, with two selected software tools: CMLCA and Brightway LCA. We migrated the system models from the CMLCA to Brightway LCA software and alternated between the ecoinvent database versions 2.2 and 3.1 to 3.6 in the system background. When using ecoinvent v3.6 instead of v2.2, the change of the indicator results ranged from to 283%. The evolution of the ecoinvent database impacted the absolute amounts of the characterized results and the relative performance between alternatives. The impact category with the highest variability was ionizing radiation, which even showed a ranking inversion with ecoinvent v3.4. In contrast, the impact of using CMLCA or Brightway was negligible because the same data and modeling assumptions caused percentage differences below 0.4%. During the semi‐automated data migration to Brightway, we identified 23 environmental flows in the CMLCA model that were not paired with their corresponding characterization factors in the published study of reference. This error had led to an underestimation of 63% in the photochemical oxidation indicator of one of the alternatives. This underestimation relates to an interoperability issue regarding the nomenclature of environmental flows in software alternatives and is a matter of data implementation rather than an issue intrinsic to the selected software. Finally, we identified improvement opportunities for the transparency and reusability of LCA models. This article met the requirements for a Gold‐Gold JIE data openness badge described at http://jie.click/badges.

Life Cycle Assessment of UV-C based treatment systems for the removal of compounds of emerging concern from urban wastewater

In the last decades particular attention is being paid to the efficient and effective removal of compounds of emerging concern (CECs) present in wastewater before their eventual reuse or disposal. Several technologies have been developed for the degradation of CECs in aqueous matrix, in this regard advanced oxidation processes (AOPs) represent a nascent technological solution developed on a laboratory scale with applications on a prototype scale. The experimental evidences have shown that AOPs processes can oxidize numerous organic compounds in a much faster and more efficient way than that of the most common disinfection processes. The most common AOPs processes are those that involve the use of H2O2/UV, O3/UV, H2O2/O3, H2O2/O3/UV, Fenton and photo-Fenton. The aim of this work is to illustrate the results of a comparative LCA study of a laboratory scale UV-C photoreactor for the tertiary treatment of urban wastewater of three treatment systems (UV-C, UV-C + H2O2 e UV-C + TiO2). In particular, the specific objective is to evaluate, from an environmental point of view, an innovative advanced oxidation system based on nanostructures TiO2 immobilized on a stainless steel mesh. Compared to the UV-C photolysis reference system, the addition of hydrogen peroxide reduces the total environmental impact of the system by almost 75 %, while the use of the stainless-steel mesh coated by the nanostructures titanium dioxide reduces the UV-C environmental impact by 30 %. These results are due to the lower energy consumption of these last treatments compared to photolysis alone. The main impacts of the three systems are related to the electric power consumption of the centrifugal pump (63–64 %) and of the UV-C lamp (32–33 %). The LCA applied to these systems has shown that TiO2 assisted photocatalysis is not yet advantageous from an environmental point of view and that, therefore, the efficiency of the system needs to be improved.

Comparative LCA study of wood and mineral non-residential buildings in Germany and related substitution potential

The construction sector is a central source of greenhouse gas (GHG) emissions. Reducing environmental impacts along the life cycle of buildings is therefore an important target. Given recent innovations in low-energy buildings and energy supply systems with low climate impacts, additional reduction potential can mainly be found in mitigating GHG emissions in other life cycle stages. The focus of mitigation has thus shifted to emissions related to material input, and comparative life cycle analyses of buildings constructed with different material types are becoming increasingly relevant in guiding regulations to achieve emission reduction targets. This paper performs comparative life cycle assessments for 48 non-residential buildings, comparing GHG emissions according to the current European standardised calculation methods. A substitution potential is introduced to evaluate the advantage of using timber as a building material. Furthermore, a comparative method is presented for assessing the substitution potential on the building level. The results show that the substitution potential for the construction of the studied buildings ranges from 5 to 48%. Specific substitution potentials are differentiated between four subcategories of non-residential buildings. The lowest substitution potential was identified for agricultural buildings and the highest for office and administration buildings. Moreover, the current research shows that the specific materials, construction, the geometry and design all affect the substitution potential of a building. On the basis of these values, it is possible to make projections regarding GHG reduction potential in the construction sector on a national scale.

A comparative LCA study on aluminum electrolytic capacitors: From liquid-state electrolyte, solid-state polymer to their hybrid

Polymer hybrid aluminum electrolytic capacitors (PHAECs) are a new generation of aluminum electrolytic capacitors (AECs) following traditional liquid AECs (LAECs) and polymer AECs (PAECs). The differences in the potential environmental impact among the three types of AECs have not been well investigated. A cradle-to-grave comparative LCA study was conducted to evaluate whether PHAECs have ecologically environmental advantages over PAECs and LAECs throughout their entire life cycle. In this study, the functional unit was taken to be 1,000,000 pieces of the AECs with 25 V rated working voltage and 150 μF rated capacitance, each operating for 2000 h. Furthermore, a capacitor manufacturer (located in Jiangsu, China) with its suppliers was investigated to obtain the life cycle inventory data of the AECs. According to the ReCiPe2016 method, climate change, fossil depletion, and photochemical ozone formation were identified as the main categories of AECs' environmental problems. Electricity consumption and aluminum ingot use were identified as the main contributors to AECs' environmental impact based on the ReCiPe2016 normalization factors (mid-point, World). The application of conductive polymer increases the environmental impact of the AECs from cradle to gate but effectively reduces their equivalent series resistance (ESR). In addition, the liquid electrolyte in PHAEC will solve the problem of large leakage currents in PAECs. The environmental impact of PHAECs from cradle to grave, thus, is no more than 30.5% of LAECs and 50.5% of PAECs, respectively. Difference analysis, sensitivity analysis, scenario analysis, and sustainability opportunities of PHAECs were also discussed. This work would provide a quantitative benchmark and calculation framework to assess the environmental burden of the PHAECs and guide environmentally conscious design, manufacturing, marketing, operation, and recycling of future PHAEC products.

Performance Analysis of a Conventional and Renewable Energy based Electric Power Generation Systems – A Comparative LCA Study

Electricity, a readily usable form of energy is much in demand in developing countries like India due to the increase in human population and their improved lifestyles. One of the criteria to achieve the developed country tag is per capita consumption of electricity. It means that all developed countries have energy-intensive economies. With climate change effects are coming into fore, countries started scrutinizing the sources of energy and electricity too. Resource intensive traditional or conventional sources of energy with matured technologies on one side and alternative energy technologies that include renewable with developed or yet to fully developed technologies on the other side are competing for electricity pie in almost in every country. This study adopts the Life Cycle Assessment methodology to determine the energy efficiency and environmental impact assessment of two competing electric power generation systems, one based on conventional energy source and another one based on the renewable energy source. It is a common knowledge that renewable systems have better energy efficiency as they do not consume fuel energy as input and also have lower carbon emissions. This study projects what extent they are better for a unit of electricity produced by both competing systems in terms of predefined metrics such as ERR/EPBT, GWP and GWMP in terms of CO2 equivalents and Green Rating for comparative purposes. The study results may be useful for policymakers as a component in the comprehensive decision-making process for energy planning to meet the future human need or greed for electricity with sustainability and also to achieve circular economy goals.

A comparative life cycle assessment of a selective-laser-melting-produced hydraulic valve body using design for Property

Abstract Selective laser melting (SLM) is known to be potentially sustainable, enabled manufacturing with complex parts with high flexible design. Existing studies have explored the environmental sustainability of SLMed parts, but there is not yet a consolidated conclusion. In this paper, industrial hydraulic valve body was taken as an example. Its part design, material preparation, and part manufacturing were included in the comparative analysis for SLM and conventional manufacturing (CM). A redesigned part using Design for Property (DfP) method was fabricated using SLM. Then, a cradle-to-gate comparative LCA study of these SLMed and CMed parts was performed, with the data from our experiments, enterprise, literature, and databases. The environmental impact of the SLMed hydraulic valve body was found to be 37.42% lower, and the SLMed optimal design can further reduce the environmental impacts 16.84%. Powder preparation is the highest stage of unit impact. For heavier valve body, with the increase of the potentials of lightweight, the environmental impacts of SLM process will become the main phrase during life cycle. Electricity is the main reason of SLM environmental impact. Therefore, to improve environmental performance, collective efforts from both designer and manufacturer are important.

Environmental Benefits of Timber-Concrete Prefabricated Construction System for Apartment Buildings – a Simplified Comparative LCA Study

The aim of a research project TiCo (Timber Concrete) is to create a standardized flexible construction system for multifamily apartment buildings for central European climatic conditions with low environmental impact. It exploits advantages of advanced prefabrication and favourable material properties of its main elements. Prefabricated structural system was designed using concrete frame with thin columns and lightweight ceilings with reinforcing core. Façades and interior partition walls were designed from prefabricated timber frame panels. The paper presents a simplified comparative LCA study of the designed TiCo building system and conventional building solutions. The compared variants had the same key parameters – load bearing capacity and heat transfer coefficients of building’s envelope. The analyses include load-bearing structures, façade, partition walls, foundations and roof. The others like HVAC systems, floors, doors, windows or tin work were not included. A simplified comparative LCA is based on procedure described in method SBToolCZ, which evaluates the quality of buildings in terms of sustainability. The assessment covered embodied environmental impacts of the construction system structures with their replacement based of their service lives. Prefabricated concrete frame structure with timber envelope was found environmentally friendlier compared to conventional solutions. The combination of the concrete load-bearing structure and lightweight timber frame panels that benefits from favourable characteristics of both materials for the given purpose appropriately used in the construction appeared to be an efficient way of minimizing building’s environmental impact.

Demanufacturing photovoltaic panels: Comparison of end-of-life treatment strategies for improved resource recovery

Predictive models to forecast the volume and material composition of end-of-life photovoltaic (PV) panels indicate that substantial material resources can potentially be recovered from silicon based PV panels in the next decades. The technical feasibility of selective mechanical delamination through milling and cleaving was experimentally studied. The achievable material recovery results are compared to current practices in end-of-life treatment, demonstrating a substantial potential to improve resource preservation. A comparative LCA study allows to conclude that a well-designed demanufacturing strategy based on selective delamination can substantially reduce the environmental impact associated with end-of-life processing of PV panels. The improved silver recovery offers perspectives for the economic viability of the described demanufacturing strategy.

Comparative impact assessment for flax fibre versus conventional glass fibre reinforced composites: Are bio-based reinforcement materials the way to go?

In many applications the use of composite materials can offer significant weight reduction opportunities, which can have a positive influence on the life cycle impact of a component or system primarily through energy saving effects in the use phase. The impact associated with the production and end-of-life (EOL) phases, however, forms a possible counter indication for systematic replacement of conventional structures by composite solutions.Bio-composites are considered a promising strategy to limit production and EOL impact. In this paper a comparative LCA study is presented for flax fibre reinforced composites based on PP on the one hand, and functionally equivalent glass fibre reinforced PP composites on the other. The analysis results and conclusions derived from a comparative attributional LCA study are summarised in this paper.

A comparative LCA study of current and future management scenarios of food waste in daejeon metropolitan city in Korea

A comparative LCA study of current and future management scenarios of food waste in daejeon metropolitan city in Korea

Environmental Evaluation of FRP in UK Highway Bridge Deck Replacement Applications Based on a Comparative LCA Study

Within the UK bridge engineering sector, fibre-reinforced polymer (FRP) decks have been increasingly used in deck replacement applications. However, study on its environmental performance is limited. This paper examines the environmental credentials of this relatively new decking system by way of a case study comparing its life cycle environmental performance – in carbon terms – with that of conventional concrete decks. In order for the findings to be more general and informative, the bridge is assumed to carry an ‘average’ volume of traffic across the highway network where it is most likely to be present. Based on the results, areas for improvement are identified in order for this decking system to be more environmentally competitive. Uncertainties and limitations of the results are also discussed.

Life-Cycle Assessment of Biodiesel Production from Microalgae

This paper provides an analysis of the potential environmental impacts of biodiesel production from microalgae. High production yields of microalgae have called forth interest of economic and scientific actors but it is still unclear whether the production of biodiesel is environmentally interesting and which transformation steps need further adjustment and optimization. A comparative LCA study of a virtual facility has been undertaken to assessthe energetic balance and the potential environmental impacts of the whole process chain, from the biomass production to the biodiesel combustion. Two different culture conditions, nominal fertilizing or nitrogen starvation, as well as two different extraction options, dry or wet extraction, have been tested. The best scenario has been compared to first generation biodiesel and oil diesel. The outcome confirms the potential of microalgae as an energy source but highlights the imperative necessity of decreasing the energy and fertilizer consumption. Therefore control of nitrogen stress during the culture and optimization of wet extraction seem to be valuable options. This study also emphasizes the potential of anaerobic digestion of oilcakes as a way to reduce external energy demand and to recycle a part of the mineral fertilizers.

Life Cycle Assessment of Mobile Telephone Networks, with Focus on the End-of-Life Phase

Life Cycle Assessment of Mobile Telephone Networks, with Focus on the End-of-Life Phase