Total Life Cycle Assessment Research Articles

Technical innovation of Autoclaved Aerated Concrete preparation from Desulfurization Wastewater and Sludge and its Life Cycle Assessment

ABSTRACT The article presents an innovative technique for the production of autoclaved-aerated concrete using desulfurization wastewater. The experiments were conducted to explore the optimal formula that meets the requirements of high compressive strength(≥5MPa) and low oven-dry density (≤600 kg m−3). Combined with specific production cases, the environmental assessment within the scope of the total life cycle assessment and circular economy assessment were carried out. Using compressive strength and maximum dry density as indicators, the optimal formulation was found to be 73%:16%:11%:30%:45% for fly ash: cement: lime: desulfurization wastewater: recycled water (process water). And the optimum ratio was 72%: 14%: 12%: 45%: 30% for fly ash: cement: lime: nanofiltration water: recycled water. The life cycle assessment contains a total life-cycle inventory and willing to pay was 61.1CNY. In addition, the GWP = 144.83 kg per cubic meter of autoclaved aerated concrete, the carbon emission reduction efficiency is 72.4%, the water saving is 0.195CNY for one ton of water, and the water saving rate is 40%. The technology is also a low-cost solution for clean production and circular economy model, promoting green and low-carbon development and meeting the requirements of “waste-free cities” popular worldwide.

Virtual Mechanical Product Disassembly Sequences Based on Disassembly Order Graphs and Time Measurement Units

Recently, the approach that defines the total life cycle assessment (LCA) and the end of life (EoL) in the early design phases is becoming even more promising. Literature evidences many advantages in terms of the saving of costs and time and in the fluent organization of the whole design process. Design for disassembly (DfD) offers the possibility of reducing the time and cost of disassembling a product and accounts for the reusing of parts and of the dismantling of parts, joints, and materials. The sequence of disassembly is the ordered way to extract parts from an assembly and is a focal item in DfD because it can deeply influence times and operations. In this paper, some disassembly sequences are evaluated, and among them, two methods for defining an optimal sequence are provided and tested on a case study of a mechanical assembly. A further sequence of disassembly is provided by the authors based on experience and personal knowledge. All three are analyzed by the disassembly order graph (DOG) approach and compared. The operations evaluated have been converted in time using time measurement units (TMUs). As result, the best sequence has been highlighted in order to define a structured and efficient disassembly.

A structured index describing the ease of disassembly for handcrafted product

AbstractBoth economic and environmental aspects significantly influence the design process since the early phases of preliminary design. The total Life Cycle Assessment (LCA) and the End of Life (EoL) of products have to be defined in the early design phases too but, for industrial products that are not feasible to automatic production, they are hard issues. However, the EoL of products can be assessed by evaluating the disassembly of joints assembling the product, even when the production process is subject to an important contribute of workmanship. In this paper, a useful method is proposed to analyze the disassembly plant of products, in order to optimize the design process in the early preliminary phases. The method quantitatively evaluates a Disassembly Index that describes the attitude of a product to be disassembled. A case study describes the disassembly attitude of structural subassemblies of a sailboat. In order to test the applicability of the model described to both manual and automated disass...

Optimizing Energy Efficiency in Operating Built Environment Assets through Building Information Modeling: A Case Study

Reducing carbon emissions and addressing environmental policies in the construction domain has been intensively explored with solutions ranging from energy efficiency techniques with building informatics to user behavior modelling and monitoring. Such strategies have managed to improve current practices in managing buildings, however decarbonizing the built environment and reducing the energy performance gap remains a complex undertaking that requires more comprehensive and sustainable solutions. In this context, building information modelling (BIM), can help the sustainability agenda as the digitalization of product and process information provides a unique opportunity to optimize energy-efficiency-related decisions across the entire lifecycle and supply chain. BIM is foreseen as a means to waste and emissions reduction, performance gap minimization, in-use energy enhancements, and total lifecycle assessment. It also targets the whole supply chain related to design, construction, as well as management and use of facilities, at the different qualifications levels (including blue-collar workers). In this paper, we present how building information modelling can be utilized to address energy efficiency in buildings in the operation phase, greatly contributing to achieving carbon emissions targets. In this paper, we provide two main contributions: (i) we present a BIM-oriented methodology for supporting building energy optimization, based on which we identify few training directions with regards to BIM, and (ii) we provide an application use case as identified in the European research project “Sporte2” to demonstrate the advantages of BIM in energy efficiency with respect to several energy metrics.

Delving into the environmental aspect of a Sardinian white wine: From partial to total life cycle assessment

The aim of this study was to deepen the assessment of the environmental impacts of a white wine produced in Sardinia (FU 750ml), performing an attributional LCA. The system boundaries were extended, from ‘cradle to gate’ (partial LCA) of a previous study, to ‘cradle to grave’ (total LCA), in order to identify the environmental impacts occurring along the wine life cycle stages (vine planting, grape production, wine production, bottling and packaging, distribution, final disposal of the glass bottle).Some assumptions were made in order to quantify the environmental impact of the transportation phase, regarding the few data which were available.Inventory data were mainly collected through direct communication with the Company involved in the study. Results showed that the environmental performance of wine was mostly determined by the glass bottle production (for all impact categories except ozone layer depletion). The second contributor was the agricultural phase, which included two sub-phases: vine planting and grape production. Results showed that the vine planting sub-phase was not negligible given its contribution to the agricultural phase, mainly due to diesel fuel consumption. Transportation impact was found to be relevant for long distance distribution (USA); the impact categories more affected by transport were acidification, eutrophication, photochemical oxidation and global warming potential.Suggested opportunities to reduce the overall environmental impact were the introduction of a lighter glass bottle or the substitution of the glass bottle with a polylaminate container.

A Research on the Concepts and Estimate Methods of Remanufacturing Rate of Engine

Based on total life cycle assessment (TLCA) and a research project on auto engine remanufacturing, this article look forward to make certain what is "Remanufacturing Rate" of engine remanufacturing and how to express it on the occasions of OEMs, independent remanufacturers and subcontracted remanufacturers in China. The concepts of ‘Remanufacturing rate’ of engine are put forward at first, and then the estimate methods are studied based on remanufacturing environment of China.