Dynamic Life Cycle Assessment Research Articles

Prolonged Carbon Storage and CO2 Reduction by Circular Design with Wood

The benefits of circularity and biogenic carbon storage are often overseen. This study links the circular design of buildings with prolonged biogenic carbon storage. Circularity in architectural design can involve extending the service life of a building frame, whilst forests grow back and store more carbon. Following this approach, Stora Enso has developed a mixed-use building concept with flexible and adaptable structures. Static and dynamic life cycle assessment (LCA) has been carried out to assess different scenarios, modelling and quantifying its potential benefits regarding whole life carbon. While whole life carbon is lower in all timber scenarios compared to conventional concrete buildings, dynamic LCA makes clear the benefits of carbon storage and carbon sequestration. Total emissions, considering a reference service life of 50 years, are 2,84 kg CO2-eq./m² floor area/year, considering biogenic carbon storage and carbon sequestration in regrowing forests. An increase of the building lifetime to 80 years aligns with a longer rotation time of forest trees, resulting in whole life carbon of -0,09 kg CO2-eq./m² floor area/year. This demonstrates that the effective implementation of built-in flexibility and adaptability can extend the service life of a building, unlocking environmental benefits of biogenic carbon storage of wood products in buildings.

Using dynamic life cycle assessment to evaluate the effects of industry digitalization: A steel case study

AbstractDecarbonization of steelmaking has stagnated while it has a considerable share of global greenhouse gas emissions and a growing demand. Digitalization is seen as a viable option to reduce emissions and costs of the sector in the near term and life cycle assessment (LCA) as a comprehensive framework to evaluate changes in production practices. In this study, we analyze the potential impact of using optimization algorithms to improve the operation of a steelmaking plant in Spain. Specifically, we study the potential effects of optimizing the sequence in which steel is produced to minimize losses during casting. The global warming (GW) impacts and economic costs are quantified using a dynamic LCA model, considering uncertainty and temporal variability using an open‐source LCA framework. The results indicate, on average, modest savings in costs and are inconclusive regarding GW emissions. Most of the cost savings come from a reduction in the use of additives and electricity, which are wasted when the steel is scrapped during casting. The methodological framework has proven useful in quantifying and interpreting the potential effects of digitalization. The implemented solution, tested in an industrial setting, allows an automated evaluation of production at the plant using the LCA model, facilitating the use of sustainability criteria in decision‐making.

Dynamic life cycle assessment of European electricity generation based on a retrospective approach

The composition of electricity varies significantly throughout the year. As a result, the environmental impact of the electricity mix is also highly variable. However, most LCA studies assume a static annual average electricity mix and neglect these fluctuations. Therefore, this study examines the time-varying environmental impacts of electricity generation in Germany, France, Italy, Spain, and Poland using a dynamic life cycle assessment. It shows that the impacts of environmental categories vary considerably depending on when the electricity is generated, resulting from the different energy generation patterns throughout the day and year. In particular, the integration of renewable energy sources such as photovoltaic systems and wind turbines leads to significant fluctuations of environmental impacts. To determine the magnitude of the variation, coefficients of variation are calculated for each environmental impact category for a representative year. High coefficients of variation of more than 20% can be observed for several environmental impact categories. In addition, both a production-based and a consumption-based approach were used for the dynamic life cycle assessment. Comparing these two approaches shows significant differences in impact category results, for example, for Italy, with an average of 15%. These differences highlight the importance of including cross-border electricity flows in assessing the environmental profile of electricity. Overall, the results of the study emphasize the need to implement dynamic electricity mix models in life cycle assessments, especially for systems with time-varying electricity consumption. The provided Excel spreadsheet files with hourly time profiles of environmental impacts for the countries studied facilitate the adoption of the developed models by other practitioners and provide a valuable tool for assessing environmental impacts.

Uncovering the research tapestry: bibliometric insights into BIM and LCA – exploring trends, collaborations and future directions

Uncovering the research tapestry: bibliometric insights into BIM and LCA – exploring trends, collaborations and future directions

Some modeling challenges in dynamic life cycle assessment

Life cycle assessment (LCA) has been a mainstream tool to evaluate the environmental impacts of products, services, and systems. Current LCAs inherently rely on the static basis and commonly fail to include temporal considerations. To better assist in the decision-making for sustainable development, dynamic LCA has been initiated to answer more complex and interdisciplinary questions. As in its initial phase, dynamic LCA faces many modeling challenges that at the same time are meaningful research opportunities. In modeling dynamic LCA, there are several key aspects that need more attention for contribution and close collaboration across the first three phases of the LCA framework.

Environmental evaluation of emerging bakery waste oil-derived sophorolipids production by performing a dynamic life cycle assessment

Sophorolipids (SLs) are promising biosurfactants that have gained significant attention due to their superior properties compared to their fossil-derived counterparts. However, the huge cost of the abstracts limits its massive production. This study investigates the viability of bakery waste oil (BWO) as an economically efficient and environmentally sustainable feedstock for SLs production. Although such waste valorisation minimizes the use of first-generation substrates, the systematic environmental impacts need to be assessed as the waste streams may introduce different materials and processes. For this reason, a dynamic life cycle assessment (dLCA) was employed to iteratively assess the environmental impacts of SLs production as technology evolved. To facilitate the comparison between each traversal, the functional unit (FU) is defined as the production of 1 kg of crude SLs. SimaPro software and Ecoinvent v3.5 database were used to perform the dLCA. Cumulative energy demand (CED), global warming potential (GWP), and ReCiPe 2016 Midpoint (H) methods were used as indicators. Surprisingly, this analysis reveals that the use of BWO as a feedstock for SLs production (15,803.3 MJ of CED and 1277.3 kg CO2 eq. of GWP) does not consistently lead to reduced environmental impacts compared to first-generation feedstocks like oleic acid (11,898.3 MJ of CED and 959.6 kg CO2 eq. of GWP). Then different pH regulators were added to improve the bioprocess and reduce the environmental impacts. Notably, the introduction of potassium hydroxide (KOH) as a pH regulator significantly decreased environmental footprints, with results showing a CED and GWP of 9301.1 MJ and 751.7 kg CO2 eq., respectively. In contrast, sodium hydroxide (NaOH) exacerbated these impacts, resulting in a higher CED (19,741.6 MJ) and GWP (1595.6 kg CO2 eq.). ReCiPe Midpoint results confirmed that the use of BWO significantly reduced the environmental impacts of chemicals, especially the first-generation feedstock, under the regulation of KOH. Finally, a comparison was made between the use of BWO and food waste as substrates, demonstrating that BWO has a greater potential for reducing environmental impact. Moreover, the study recommends that combining BWO and food waste, along with other productivity-enhancing techniques like fed-batch fermentation and in-situ separation, will further enhance the sustainability of SLs production.The findings from the dLCA framework provide valuable insights for achieving sustainable SLs production, simultaneously enhancing SLs yield and environmental friendliness. This study highlights the effectiveness of dLCA as a method to track and analyze emerging technologies, guiding them toward a sustainability pathway.

Life cycle assessment of carbon emissions for bridge renewal decision and its application for Maogang Bridge in Shanghai

The renewal of old bridges is sometimes restricted to avoid the high carbon emissions caused by materials and construction, which however might not be conductive to climate change mitigation due to their insufficient functions. In order to facilitate the optimization of renewal timing and strategy from the perspective of reducing the comprehensive global warming impacts, we put forward the low-carbon bridge renewal decision method referring to the ideas of consequential life cycle assessment (LCA) and dynamic LCA. In the proposed method, a comparative system boundary matching the bridge renewal characteristics is constructed, where the carbon emission reduction owing to the traffic efficiency improvement by functional updating is incorporated as the low-carbon benefits of renewal, and three types of time-dependent factors, i.e., time-dependent characterization factor, trend factors and changes of traffic demands, are introduced to characterize the influence of renewal timing. The proposed method provided guidance for the renewal of Maogang Bridge, the first long-span cable-stayed bridge in Shanghai. Results illustrate that the global warming impacts of renewal construction activities and the low-carbon benefits from functional updating decrease with the renewal timing. For Maogang Bridge, the rapidly increasing traffic demands inevitably advocated renewal in advance, and the reduction of global warming impacts from emission reduction or carbon uptake could be manifested for renewal in advance. Adopting material recycling in the disposal of old bridge helped reconstructing a new bridge while deconstructing the old one in 2019 becoming the finally selected low-carbon renewal strategy, which is expected to reduce 15.04 kt CO2e-2019 compared to the essential renewal in 2050 with the landfill disposal method. The robustness of the strategy choice has been justified, given the variations of analytical time horizon, expected emission trends and repair emissions. In this way, the low-carbon renewal decision method could build a quantitative basis for judging the urgency of functional updating and verifying the low-carbon benefits of immediate concrete recycling in up-coming urban renewals.

Temporal considerations in life cycle assessments of wooden buildings: Implications for design incentives

The building and construction sector plays a vital role in mitigating climate change. Consequently, the use of wood and bio-based materials as a strategy for reducing the environmental impact of buildings is increasing. However, along with realising the potential environmental benefits of biomass, the focus on assessment methods and their inherent uncertainties increases. Typically, Life Cycle Assessment (LCA) is used for quantifying the environmental performance of buildings but is often criticised for not considering temporal factors related to emissions. Therefore, dynamic LCA approaches have been developed. To understand how dynamic LCA influences building design incentives, this study compares traditional LCA and dynamic LCA results on 45 cases of wooden buildings. The study finds that the overall ranking of the buildings’ environmental performance is stable, irrespective of the method used. However, the dynamic biogenic carbon accounting methods significantly influence the results and shift burdens between upfront and future emissions. Therefore, methods for time-distributed biogenic carbon accounting crucially need addressing in LCAs of wood and bio-based products.

Comparative numerical modeling complemented with multi-objective optimization and dynamic life cycle assessment of coaxial ground heat exchangers with oval-shaped and typical circular-shaped configurations

Geothermal energy showcases significant potential as a sustainable energy alternative employed for direct applications such as space heating and cooling, industrial processes, and greenhouse heating. However, despite these favorable attributes, conventional Ground-coupled Heat Pumps (GCHPs) can potentially result in significant environmental and economic consequences, including greenhouse gases and high operational costs. The Coaxial Ground Heat Exchanger (CGHE) is the chief role component for harnessing geothermal energy in GCHPs. This investigation provides comprehensive numerical modeling complemented with multi-objective optimization and seasonal life cycle assessment of CGHEs with newly developed oval-shaped (oval-CGHEs) and typical circular-shaped (circle-CGHE). The system design and dispatch of the oval-CGHEs are optimized by considering a novel optimization approach that synergistically encompasses four optimization scenarios, namely minimum Ground Heat Exchanger (GHE) number and minimum GHE length, each with multi-material topology optimization of outer tube selection criteria. The system's Life Cycle Energy Consumption (LCEC), Life Cycle Costs (LCC), and Life Cycle CO₂ emissions (LCCO₂) are introduced in the optimization stage of the oval-CGHEs and compared with typical circle-CGHE. Toward these goals, a series of three-dimensional simulations coupled with a pulse-load finite line source model is executed and validated using the authors' practical field experiment based on combined analyses, including the energy, economic, and environmental multi-criteria, to assess the different objectives and case studies. The optimization results reveal that oval-CGHEs, particularly with inner tube position optimization, consistently outperform the traditional circle-CGHEs in all the investigated scenarios. It is revealed that the most favorable scenario involves substituting traditional circle-CGHEs with oval-shaped CGHEs, utilizing a high-density polyethylene inner tube and a steel outer tube, and adopting a minimum GHE length. This approach remarkably reduces the required length of the GHEs by up to 15.00% and achieves the most substantial reductions in LCEC by up to 13.87%, LCC by up to 10.91%, and LCCO₂ emissions by up to 13.27%, respectively.

Analysing temporal factor in dynamic life cycle assessment of solar photovoltaic system

Static life cycle assessment is a mature and widely used tool for quantifying the environmental performance of a solar photovoltaic system. The system’s lifetime is estimated to last for 25 years but there are cases that the whole system could ultimately be replaced or dysfunctional. This study proposed a dynamic life cycle model integrating time-varying factors to assess the cause affecting photovoltaic system performance over its expected lifetime and compare the scenario with a static life cycle analysis. Results show that the unpredictable weather in Malaysia causes a consistent drop in the module’s degradation rate, which significantly affects the system’s lifetime. A fixed assumption over a system’s lifespan could lead to a 20 % difference in the overall impact assessment. However, it does not significantly affect the static outcome, with only 0.05 years increment to the system’s energy payback time and 1.3 years longer on its return on investment. Conclusively, dynamic data changes the result by 5 % for environmental and 8 % for financial impact assessment. This proves that the unknown value hidden from the basic assumption in the static model can be defined by implementing the temporal elements into the dynamic model.

Analysis of forestry management based on dynamic life cycle assessment of biogenic carbon: A case study of a forestry resource-based city in Northeast China

Temporary carbon storage and substitution benefits of harvested wood products (HWPs) aid in mitigating global warming. However, the extent of this effect remains unclear. Current studies typically rely on a simple summation of the annual carbon sink. This method overlooks the fact that, due to radiative forcing delay, each ton of carbon sequestered has an impact on global warming, which dynamically changes year by year. Such an oversight could lead to an underestimation of HWPs' contribution to global warming mitigation. This study focused on a forestry resource-based city in Northeast China and utilized the Carbon Budget Model for the Canadian Forest Sector (CBM-CFS3) and dynamic life cycle assessment (DLCA) to quantify the dynamic global warming impact (DGWI) of forestry biogenic carbon. The results indicate that: 1) From 2020 to 2120, the maximum DGWI could reach −42.70 Mt CO2e. Enhancing the collection and utilization of harvesting residues and promoting products with longer lifespans and higher substitution potential can further increase these benefits. 2) The DLCA method, integrating substitution effects, offers a more precise evaluation of forestry's climate mitigation benefits. Across all scenarios and periods in this study, HWPs' contribution to mitigating global warming, as calculated by the DLCA method, exceeds that estimated by the simple carbon sink summation method by 7.70 %–560.72 %. These findings help to delve deeper into the role of forests in emission reduction and carbon sequestration, providing important references for achieving sustainable forestry management.

Bridging Housing and Climate Needs: Bamboo Construction in the Philippines

The Philippines faces a significant shortage of affordable housing, and with the growing urgency brought by climate change, there is a pressing need for more sustainable and affordable building solutions. One promising option is cement bamboo frame buildings, which blend traditional bamboo building methods with modern materials. This approach is already being implemented in social housing projects in the Philippines. Dynamic lifecycle assessment (DLCA) calculations show that these bamboo buildings can effectively reduce overall CO2 emissions. Before a building’s end of life, biogenic effects offset approximately 43% of its total production emissions, while the temporary carbon storage afforded by these biogenic materials further reduces total emissions by 14%. In comparison to concrete brick buildings, bamboo constructions reduce emissions by 70%. Transforming an unmanaged bamboo plantation into a managed plantation can potentially triple the capacity for long-term CO2 storage in biogenic materials and further reduce net emissions by replacing concrete with bamboo as the main construction material. Thus, bamboo construction offers a potent, economically viable carbon offsetting strategy for social housing projects.

Dynamic Life Cycle Assessment Framework of Cold Food Storage Facilities

The imperative of responding to anthropogenic climate change that is driving energy infrastructure managers to implement resilience enhancing policies such as hourly scale dynamic pricing concurrently drives energy intensive industries to monitor energy usage at higher fidelity. This study proposes a Dynamic Life Cycle Assessment (DLCA) framework specifically tailored for cold food storage facilities which provide essential thermodynamic resilience to the human food web and consumes a large share of the web's energy footprint. Different from the conventional LCA, which delivers a snapshot of the environmental impacts and cost statically, DLCA can accommodate temporal variations in operating conditions and energy usage. It interacts with real-time monitoring data and fluctuating energy rates to provide a more accurate and time-sensitive environment impact and cost evaluation. Key parameters from real-time sensors and reference databases are summarized to lay the foundation for DLCA of cold food storage, like operating power and hours, shipment arrival time, and transportation fuel economy. Its feasibility and reliability are validated by scenarios that simulate different operating conditions, like shift change to utilize off-peak rate and change of packaging materials. The proposed framework allows facility operators and policymakers to pinpoint bottlenecks and seize opportunities for environmental impact and cost reduction.

Turning dynamic LCA principles into practice

The building and construction sector quantifies the environmental impacts of buildings using the Life Cycle Assessment (LCA) method. To put LCA into practice often simplified application of the LCA method is used, without considering timely aspects. Instead, the method dynamic LCA includes timely aspects, which are more complex in the modeling and thus difficult to apply. To investigate the consequences of using the dynamic LCA method, this study develops a tool that takes data available in a simple LCA tool that follows the standardized LCA method and calculates dynamic LCA results. The tool reimplements the calculation engine from the simple LCA tool and adds the more complex aspects of dynamic LCA afterward. Doing so makes it possible to add other complex methods to the original calculation engine to help investigate more complex methodological aspects in the future.

Application of sensitivity analysis on building dynamic lifecycle assessment of GHG emissions: a French case study

This study presents a novel approach to simplify the dynamic life cycle assessment (DLCA) of buildings by identifying and prioritizing influential dynamic parameters (DPs) to improve building energy performance and reduce greenhouse gas emissions. Current life cycle assessment (LCA) methodologies lack temporal considerations, which can significantly impact a building’s environmental footprint over its multi-decade life span. We conducted an extensive literature review on DPs in DLCA, informing the creation of a multi-scenario parametric framework. A case study was then selected to apply the developed DLCA methodology and perform a global Sensitivity Analysis to pinpoint the most influential DPs on global warming potential. The DLCA framework integrates data from the French database for environmental product declarations and utilizes EnergyPlus simulations for operational emissions assessment. The study identifies ten DPs, revealing the most impactful ones to be industry and waste sector emissions reductions, building occupancy, and global warming. Additionally, we found minimal interactions between DPs, which facilitates the simplification of the DLCA process. This research enables building stakeholders to focus on a more selective set of parameters, enhancing the efficiency and accuracy of building life cycle assessments. Overall, our findings contribute to the continuous improvement of LCA methodologies and promote sustainable building practices.

Exploring capacities, environmental benefits and potential for a circular economy on waste plastic bottles in Hong Kong

This paper explores capacities, benefits and potential for a circular economy on waste plastic beverage containers in Hong Kong. Regarding existing circular capacities, we show that a pilot subsidy for selected recyclers achieved a plastic bottle recovery rate of 3 %. Its extension to all active recyclers would raise the recovery rate to 23 %. The analysis of circular benefits uses a dynamic life-cycle assessment along the Shared Socio-economic Pathways. It demonstrates that replacing single-use containers with reusable ones would achieve substantial impact reductions, e.g. 81 % for CO2 and 88 % for PM2.5 amongst others. When assessing potential for a circular transition in beverage container management, mapping stakeholder interests shows that the government's expressed preference for recycling is not shared by other groups. Rather, societal and corporate stakeholders’ strong preference for refuse and reuse solutions underscores that higher-ranking circular approaches like a plastic tax or even a selective ban would enjoy public support.

Electrospun nanofibrous membranes for membrane distillation application-A dynamic life cycle assessment (dLCA) approach.

Membrane distillation (MD) for water desalination and purification has been gaining prominence to address the issues relating to water security and the destruction of aquatic ecosystems globally. Recent advances in electrospun membranes for MD application have improved antifouling and anti-wetting performance. However, the environmental impacts associated with producing novel electrospun membranes still need to be clarified. It is imperative to quantify and analyze the tradeoffs between membrane performance and impacts at the early stages of research on these novel membranes. Life Cycle Assessment(LCA) is an appropriate tool to systematically account for environmental performance, all the way from raw material extraction to the disposal of any product, process, or technology. The inherent lack of detailed datasets for emerging technologies contributes to significant uncertainties, making the adoption of traditional LCA challenging. A dynamic LCA (dLCA) is performed to guide the sustainable design and selection of emerging electrospun poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) electrospun membrane (E-PH) and hybridizing polydimethylsiloxane (PDMS) on E-PH membrane (E-PDMS) for dyeing wastewater treatment technologies. The associated environmental impacts are related to the high energy demands required for fabricating electrospun nanofibrous membranes. After LCA analysis, the E-PDMS membrane emerges as a promising membrane, due to the relatively low impact/benefit ratio and the high performance achieved in treating dyeing wastewater.

Retrospective dynamic life cycle assessment of residential heating and cooling systems in four locations in the United States

Heating, ventilation, and air conditioning systems (HVAC) and water heaters are responsible for a relevant portion of the total Greenhouse Gas (GHG) emissions related to the building life cycle. A significant effort will be needed to substantially reduce building-related GHG emissions to meet the increasing demand to meet goals for energy use and GHG emission reduction. This study evaluates the GHG emissions of two alternative residential HVAC systems: natural gas furnace and electric air conditioning, and an electric heat pump, in a typical single-family house located in four different climate zones in the U.S. using a life cycle assessment model that includes spatial variations such as climate and electricity generation mix and temporal variations such as the changes in the generation mix and greenhouse gas emission factors for electricity generation over time. The locations selected are in very cold, cold, marine (temperate), and hot-humid climate zones in the U.S. The reduction in GHG emissions over time occurred due primarily to the changes in the electricity grid mix. As a result, the heat pump system had the greatest reduction in GHG emissions over time and had the lowest GHG emissions over the study period in two of the four locations. If the decarbonization of electricity production continues and refrigerants with low GHG potential are widely used, the heat pump can be the HVAC system with the lowest GHG emissions in all climate zones studied.

Development of the virtual battery concept in the paper industry: Applying a dynamic life cycle assessment approach

Energy-intensive industries face the challenge of reducing carbon emissions while remaining competitive. Key measures include fossil fuel substitution, energy efficiency, and integration of renewable energy sources, but their fluctuating production profile makes them difficult to integrate and require industries to adapt their current consumption and production patterns to become more flexible.In this study, the virtual battery concept (VBC), exemplarily demonstrated for a specific site in the paper industry, is introduced and evaluated from an environmental, energetic, and techno-economic perspective. A mathematical optimization model of the class mixed integer linear programming (MILP) was applied to express the industrial site as VBC and derive the operational data basis for the subsequent life cycle assessment (LCA). A dynamic LCA approach is presented to allow the consideration and assessment of the temporal behavior of energy load profiles and their associated environmental implications.The results showed that compared to a static LCA, the dynamic approach leads up to 42 % lower greenhouse gas (GHG) emissions for 1 MJ of public electricity. The global warming potential (GWP) of the total energy supply chain was reduced by 40 % for electricity and 8 % for heat, respectively. By means of a scenario analysis, the GWP to produce one ton of paper was reduced up to 33 % compared to the business-as-usual (BAU) case to 672 kgCO2eq.r in the best case. However, the total primary energy demand (PED) increased by 34 %, but the fossil PED was reduced by 32 % and the renewable PED increased by 157 %. The renewable PED share covered up to 67 % of the total PED. The techno-economic analysis revealed total annual cost savings of up to 44 % to 64.6 € per ton of paper. Environmental costs were estimated to range from 79.6 to 88.9 € per ton of paper.The VBC is considered a promising approach to utilize regional renewable excess electricity effectively, reduce fossil-based energy generation, increase grid stability, and to avoid costly grid infrastructure investments in future. In principle, the VBC is site-independent and replicable to other industries but needs to be evaluated site specifically according to certain process characteristics and requirements.

Life cycle assessment of microgreen production: effects of indoor vertical farm management on yield and environmental performance

The global production of plant-based foods is a significant contributor to greenhouse gas emissions. Indoor vertical farms (IVFs) have emerged as a promising approach to urban agriculture. However, their environmental performance is not well understood, particularly in relation to operational choices where global warming potentials (GWP) can vary between 0.01–54 kg CO2e/kg−1 of leafy greens produced. We conducted a life cycle assessment (LCA) of a building-integrated IVF for microgreen production to analyse a range of operational conditions for cultivation: air temperature, CO2 concentration, and photoperiod. We analyzed a dynamic LCA inventory that combined a process-based plant growth model and a mass balance model for air and heat exchange between the chamber and the outside. Results showed that the GWP of IVFs can vary greatly depending on the operation conditions set, ranging from 3.3 to 63.3 kg CO2e/kg−1. The optimal conditions for minimizing GWP were identified as 20 ℃, maximum CO2 concentration in the chamber, and maximum photoperiod, which led to a minimum GWP of 3.3 kg CO2e/kg−1 and maximum production of 290.5 kg fresh weight week-1. Intensification of production thus led to lower impacts because the marginal increase in yield due to increased resource use was larger than the marginal increase in impact. Therefore, adjusting growing conditions is essential for the sustainability of urban food production.