Perspective Of Life Cycle Analysis Research Articles

Application of nanofluids in industrial processes. The case of food processing

A crossflow heat exchanger for drying purposes integrated in a pasta manufacturing process is considered in the present work. Different nanofluids, i.e., Al2O3, TiO2, and CuO, are considered with particle dimensions ranging from 20 to 60 nm and volumetric concentration in the range of 0 %–5%. Base fluid is water. An analytical model of the heat exchanger is developed and the energy performance is evaluated from a Life Cycle Analysis perspective by considering the embodied energy of the different nanoparticles. The utilization of the nanofluids allows to reduce the dimensions of the device. In particular, a reduction in length of 26 %, 25 %, and 27 % is estimated for Al2O3, TiO2, and CuO respectively. Oppositely, there is not an enhancement of the energy performance. In particular, an increase of the operating energy is detected since the reduction of the dimension increases pressure losses and the saving in embodied energy due to the use of less material is not sufficient to offset the increase in embodied energy due to the utilization of the nanoparticles.

Potential water reuse pathways from a life cycle analysis perspective in the poultry industry

Achieving sustainable water use in the food industry requires a paradigm change and transforming it towards circularity by exploring opportunities for water reuse. Life Cycle Assessment can comprehensively evaluate the environmental impacts of the water management and reuse options throughout their life cycle to ensure improvement of environmental performance. Through the example of a poultry processing plant it was shown that improving wastewater treatment technology can reduce the metal depletion category by almost 30 % by cutting down chemical use by 90 %. Further mitigation of environmental damage could be achieved by either choosing technological or agricultural reuse options depending on the needs or local constraints. While the improvement is not massive since the implementation of additional technologies require further resources, the Reduce scenario (technological reuse with 50 % reduction of water consumption) compared to the direct discharge into a surface water body resulted a decrease of 11.0 % and 17.1 % in freshwater consumption and 7.6 % and 2.6 % in metal depletion units. On the contrary, irrigation is better than technological reuse with regard to human health and resource scarcity indicators. Legislative requirements and social acceptance issues might slow down the process of closing the loop in the water management of the food industry; nonetheless results show that opting for water reuse is an environmentally sound solution even in this sector.

Life‐cycle analysis of sustainable aviation fuel production through catalytic hydrothermolysis

AbstractCatalytic hydrothermolysis (CH) is a sustainable aviation fuel (SAF) pathway that has been recently approved for use in aircraft fuel production. In alignment with broader sustainable aviation goals, SAF production through CH requires a quantitative assessment of carbon intensity (CI) impacts. In this study, a current‐day life‐cycle analysis (LCA) was performed on SAF produced via CH to determine the CI. Various oily feedstocks were considered, including vegetable oils (soybean, carinata, camelina and canola) and low‐burden oils and greases (corn oil, yellow grease and brown grease). Life‐cycle inventory data were collected on all processes within the CH LCA boundary: feedstock cultivation and/or collection, preprocessing, hydrothermal cleanup and CH, biocrude refining, fuel transportation and end use through combustion. Baseline results show that the CH‐produced SAF can be generated with CI reductions ranging from 48 to 82% compared with conventional jet fuel. Modest improvements to CI can be achieved through incremental changes to the brown grease CH process, such as relaxing the dewatering specification and implementing renewable natural gas and electricity, which could decrease the CI from 22.9 to 7.9 g CO2e/MJ. Total CH fuel production potential was also assessed on the basis of current or near‐future feedstock availability and CI. The total biofuel production potential of CH (SAF and renewable fuel co‐products) in the US sums to approximately 3487 million gallons per year, with 97% of these volumes having a CI below 50% of that for petroleum jet fuel. The study shows that from an LCA perspective, CH offers a viable SAF pathway that is comparable with existing SAF pathways like hydroprocessed esters and fatty acids.

Cost and financial evaluation model for the design of floating offshore wind farms

A cost and financial evaluation model is proposed for floating wind farm designs. The model evaluates the cost of the offshore farms depending on the required capacity, technical aspects, and technology implemented, among other aspects. The costs involved in the different phases of the farm construction are studied. The main equations developed for the model construction are simplified and presented in this document. This study presents a comparison of several financial indicators for the following floating concepts: Spar-Buoy (TELWIND), Tension-Leg-Platform (CENTEC-TLP) and Semi-Submersible (SATH). The model is applied to a farm composed of thirty-four 10 MW floating turbines in a Life Cycle Analysis perspective. The model allows the determination of the optimal floating platform for a site and identifies the optimal solution for a floating farm depending on the economic and financial aspects associated.

How does future climatic uncertainty affect multi-objective building energy retrofit decisions? Evidence from residential buildings in subtropical Hong Kong

Energy consumption of and carbon emissions from buildings, which substantially depend on outdoor climate conditions, may be susceptible to future climate change. However, how future climatic uncertainties affect decision-making regarding building energy retrofits is unclear from the life-cycle analysis perspective. This study used typical high-rise public rental housing buildings in subtropical Hong Kong as a case study to consider future climatic uncertainties under representative concentration pathway scenarios and in different general circulation models to estimate their effect on multi-objective building retrofit decisions considering trade-offs among different objectives, namely, life-cycle economics, life-cycle carbon emissions, and operational energy use impacts. The results indicate the significant influence of future climatic uncertainties on the optimal values of building energy retrofit measures. The passive house infiltration standard and thick (0.06–0.1 m) polyurethane foam insulation can be recommended for long-term future climatic conditions (RCP8.5–2065s). By contrast, optimal values of glazing materials, horizontal shading projection factors, and window-to-wall ratio are not susceptible to future climatic uncertainties. Uncertainties from different general circulation models are another notable factor affecting optimal values and retrofit options. This study reveals the importance of considering future climatic uncertainties when deciding optimal values and selecting building energy retrofit options.

Carbon Footprint Comparison of Bitcoin and Conventional Currencies in a Life Cycle Analysis Perspective

Carbon Footprint Comparison of Bitcoin and Conventional Currencies in a Life Cycle Analysis Perspective

Carbon emission effect of the dock-less bike-sharing system in Beijing from the perspective of life cycle assessment

As the government has begun to promote the sharing economy and green travel, shared bikes have wide spread in many cities in China. Bike sharing system (BSS) facilitates people's travel, relieves traffic jams, and mitigates carbon emissions. In this research, a basic method is proposed to measure the carbon emission mitigation of dock-less BSS from the perspective of life cycle analysis (LCA). The method is applied in a typical city of China (i.e., the city of Beijing). The carbon emissions of six models of shared bikes in Beijing are calculated in this paper. The results indicate that: (a) the use process of dock-less BSS has mitigated carbon emissions in the central district of Beijing (9.23 Mt CO$_{\text{2-eq}}$ in 2016 and 9.26 Mt CO$_{\text{2-eq}}$ in 2017); (b) in consideration of all life cycle processes of BSS, the carbon emissions actually has risen with the best scenario of 10% substitute rate (i.e., 33.2 Mt CO$_{\text{2-eq}}$ in 2016 and 80.9 Mt CO$_{\text{2-eq}}$ in 2017); (c) the carbon mitigation effect of BSS is closely related to the processes of production, maintenance and rebalancing. Finally, to promote the effect of carbon mitigation, it is necessary to control the number of shared bikes and increase their utilization rate.

Benchmarking environmental and economic indicators of sludge management alternatives aimed at enhanced energy efficiency and nutrient recovery

Wastewater treatment plants (WWTPs) have been developed as multifunctional systems that aim to eliminate pollutants present in wastewater, manage the sludge produced and improve energy efficiency. Specifically, sludge management accounts for the largest share in operational costs. Considering the relevant role of sludge treatment within the overall management scheme, this study aims to evaluate different alternatives and strategies for sludge management and treatment from the perspective of life cycle analysis, with special emphasis on those options that reduce environmental impacts and economic costs. Two pre-treatments (chemical or thermal) and two post-treatments (composting unit followed by land application or incineration) were evaluated to improve the eco-balance of the anaerobic digestion (AD) process in terms of operational (biogas production and digested sludge), environmental and economic indicators. According to the results obtained, both sludge pre-treatment alternatives proved to be an adequate alternative to improve biogas production without negatively affecting environmental and economic impacts. Finally, if the final disposal of the digestate is analysed, its application to the soil as a biofertiliser is recommended, since it presents a better environmental profile than incineration.

Scenario-based DEA assessment of energy-saving technological combinations in aluminum industry

This study deals with technology evaluation by employing the data envelopment analysis (DEA) methodologies from a life-cycle analysis (LCA) perspective. Aluminum production is associated with high electricity consumption. Thus, the environmental pressures of the whole production chain largely rely on the electricity generation process. This is particularly true for China, because coal-fired power generation dominates China’s electricity supply. Many of aluminum plants in China consume electricity which is directly supplied by coal-fired plants. Given these facts, LCA perspective in this study is believed to be of distinctive significance. Therefore, this paper discusses the process requiring high-energy consumption and causing high pollution from the LCA perspective and combines data envelopment analysis with LCA to evaluate and select energy-saving technological routes throughout for the complete supply chain. In total, 16 technological combinations are considered, and three models are established for different sets of efficiency indicators: energy performance indicator, energy performance indicator with undesirable output, and total performance indicator. Moreover, four scenarios with different policy considerations are designed: baseline scenario, subsidy scenario, low-carbon-price scenario, and high-carbon-price scenario. The results show that upon only considering energy input and output at the same price, a power generation mode has the greatest impact on energy consumption. After considering undesirable output, such as pollutant emissions, the technological routes including coal-fired power generation have the worst performance. Considering all inputs and outputs with the same price, the most crucial factor affecting efficiency is cost, followed by anode; subsidies have a low effect. For the four scenarios, two technological routes including a biomass-integrated gasification combined cycle power generation and inert anode rank in the top 50% decision-making units with three efficiency indices. This paper proposes an effective decision-making method for evaluating and selecting energy-saving technology routes for the aluminum industry, which can be easily applied to other sectors with similar characteristics. This provides a generic framework for a profound analysis to promote clean production and environmental sustainability.

Waste‐to‐energy recovery potential: A case study at Jaipur railway station

AbstractA study was conducted at the Jaipur railway station in Jaipur, India, to give the perspectives of the actual waste management practices there. Required information was collected from the stakeholders by means of semi‐structured questionnaires, individual and group interviews, and recorded, official data regarding waste generation, collection, transportation, and disposal. Further quantitative and compositional analyses were performed by means of surveys and measurements. Field visits were made for collection of waste samples for quantification and for the study of its management. The field data were compiled and analyzed by sorting the waste into different components. It was found that 1.8 tons of solid waste is collected per day, and a considerable percentage of it comprises paper, plastic, and glass. Excluding the inerts, which are irrelevant from the point of view of energy saving and recovery potential, the average moisture content was found to be 3.38%. From the perspective of life cycle analysis, the option of composting or recycling would give savings of 28.33 gigajoules (GJ) per day over landfilling, while combustion would give savings of 2.97 GJ per day in comparison to landfilling. Analysis based on a compositional model gives a heat value of 8,157.87 kilojoules per kilogram, which amounts to 14.68 GJ of energy per day.

Feasibility Assessment of the Use of Recycled Aggregates for Asphalt Mixtures

The use of recycled aggregates, manufactured from several by-products, to replace virgin aggregates in the production of pavement asphalt mixtures needs to be encouraged. Nevertheless, there are some concerns and uncertainties about the actual environmental, economic and mechanical performance resulting from the incorporation of recycled aggregates in asphalt mixtures. Therefore, this paper has the goal of discussing important features to help decision makers to select recycled aggregates as raw materials for asphalt mixtures. Based on the literature review carried out and the own previous experience of the authors, the article’s main findings reveal that incorporating some of the most common recycled aggregates into asphalt mixtures is feasible, even in a life-cycle analysis perspective. Although some specific technical operations are sometimes necessary when using recycled aggregates in asphalt mixtures, some benefits in terms of environmental impacts, energy use and costs are likely to be achieved, as well as in what concerns the mechanical performance of the asphalt mixtures.

Characterizing the essential materials and energy performance of city buildings: A case study of Macau

Abstract The lack of a clear understanding of the consumption of materials and energy in construction activities and by existing buildings has hindered sustainable urban development in Macau. This study is therefore designed to quantify the consumption of building materials and energy in Macau over past 16 years, from the perspective of life cycle analysis. The results show that there has been rapid growth in the annual consumptions of both materials and energy throughout the entire lifetime of buildings. In 2016, the construction of buildings contributed to almost all materials use during their lifetime, which in 2015 was approximately 10 times greater than in 1999, but the energy consumption of buildings only accounted for 7.8% of their total energy consumption. The amounts of material and energy consumption in the construction of buildings are about 1.375 tons/m2 and 1176.72 MJ/m2, respectively. Most energy was consumed during the operational lifetime of the buildings however, constituting 92.2% of the total energy consumption; this is particularly the case in the gaming industry. In 2016, the average energy consumption of residential buildings was 264.97 MJ/m2·year, which actually increased. However, the management and recycling of building waste in Macau is still an area that is underdeveloped. Actually, nearly all building materials and energy are imported from neighboring regions in mainland China, resulting in potential resource and energy supply risks for Macau. The findings obtained in this study will enable policy makers, designers, and building users to make more sensible judgments in promoting the development of sustainable buildings in Macau and elsewhere.

Uncovering driving forces on greenhouse gas emissions in China’ aluminum industry from the perspective of life cycle analysis

With the rapid growth of aluminum production, reducing greenhouse gas (GHG) emissions in China’s aluminum industry (CAI) is posing a significant challenge. In this study, the energy-related GHG emission trajectories, features and driving forces of CAI are analyzed from the perspective of life cycle analysis (LCA) from 2004 to 2013. Results indicate that CAI experienced a rapid growth of energy-related GHG emissions with an average annual growth of 28.5 million tons CO2e from 2004 to 2013. Energy-scale effect is the main driving force for energy-related GHG emissions increase in CAI, while emission-factor effect of secondary aluminum production plays a marginal effect. Construction and transportation-related activities account for the bulk of the embodied emissions, accounting for more than 40% of the total embodied emissions from CAI. Policy implications for GHG mitigation within the CAI, such as developing secondary aluminum industry, improving energy mix and optimizing resource efficiency of production, are raised.

Driving societal changes towards an electromobility future

In Europe, road transport accounts for more than 71 % of transport-related CO2 emissions with cars accounting for 73 % of passenger traffic and the majority of greenhouse gas (GHG) related emissions. As part of the European strategies until 2030 and 2050, the European Commission’s (EC) White Paper BRoadmap to a Single European Transport Area Towards a competitive and resource efficient transport system^ (EC [1]) points out the need to reduce GHG emissions from transport by at least 60 % until middle of the century (2050) with respect to 1990 levels. Until 2030, the goal is for transport to reduce GHG emissions by around 20 % with respect to 2008 levels. These decarbonisation targets impose significant economical, social and technological challenges. When moving towards a low carbon economy, electromobility is seen as a key component of the agenda for sus ta inable mobi l i ty in Europe . By 2050, Bconventionally fuelled vehicles^ (vehicles using nonhybrid, internal combustion engines) are expected to be banned from cities giving place to other technological options such as electric vehicles powered by electricity. These can make use of renewable energy sources which will reduce the carbon footprint from a life cycle analysis perspective. Recently, the European Commission adopted the Strategic Energy Technology Plan (SET Plan) with the aim to ensure EU’s leadership in the development and deployment of low carbon energy technologies in a costeffective way (EC [2]). Battery electric vehicles (BEVs), together with plug-in hybrid vehicles, only account for 0.5 % of the total new vehicle registrations in the EU-27 (EEA [4]). The use of renewable energy sources in the electricity production mix is important towards decarbonisation of the whole cycle: the Well-to-Wheel (WtW) cycle comprises the entire chain of production and usage of vehicles, the Well-to-Thank (WtT) and the Tank-to-Wheel (TtW) emissions. However, the use of renewable electricity in road transport remains low, around 13 kilotonnes oil equivalent (ktoe) (EEA [3]). Several barriers can be found in the literature as possible factors to justify the above panorama. The paper by Buhne, et al. in this special issue presents an overview and points out the obstacles to overcome to assure a higher market penetration of electric vehicles. On the one hand, the additional costs due to development of smart grids, intelligent electricity distribution systems and other infrastructure-related costs represent an additional investment in terms of construction and maintenance costs for road developers and managers (typically the public administration). On the other hand, the high purchase costs of electric vehicles, the limits imposed by low availability of charging infrastructure and its coverage, the charging time and the limited battery range often do not cope with main requirements of drivers’ daily activity patterns. Subjective factors such as those related to psychological aspects such as range anxiety and aesthetic variables have been proved to be a barrier, as well. Addressing these barriers will be important to increase the competitiveness of e-vehicles in Europe as pointed out by Figenbaum, et al. However, the social competitiveness of BEVs will depend to some extent on the evolution of price of fuels and electricity as well as the battery costs. Also, the internalisation of external costs included in the This article is part of the Topical Collection on Driving Societal Changes towards an Electro-mobility Future

Environmental and technical improvement of a grape must concentration system via a life cycle approach

Irregularities in grape yields can often affect wine production both quantitatively and qualitatively. Hence concentration systems, such as those based on reverse osmosis, are often employed to overcome such problems. The present study illustrates the results of a life cycle assessment approach implemented as means to improve the existing performance and sustainability of a specific industrial reverse osmosis concentration system used in a southern Italian winery to concentrate a specific must. The application of lifecycle approaches to reverse osmosis must concentration is sparsely documented in scientific literature with little or no specific data. The life cycle assessment of this study, developed using large amounts of inventory data and other novel information gathered from industrial testing, has highlighted the use phase as the most impacting one due to the energy consumption during the concentration operations and due to the membrane cleaning operations. In view of these results, the machine setup was improved and tested by varying the feed-flow velocity and the resulting new setup re-assessed via a life cycle approach. The final results exhibit the relationship between permeate production and feed flow velocity that does not appear to have been sufficiently investigated in other work found in literature regarding wine must. Specifically, the curve fitted to the experimental readings indicates that the maximum performance of the reverse osmosis system under analysis is achieved with a feed-flow velocity of approximately 2 m/s. Furthermore the new optimised setup of the machine lowered the environmental profile of all impact categories within a range from a minimum of 25.3% to a maximum of 26.7%, due to lower energy consumption, higher permeate production and reduced cleaning operations for the membranes. Concurrently to the environmental optimisation a technical improvement was identified, namely the substitution of the over-dimensioned piston pump, together with a potential reduction of purchase, running and labour costs of the optimised reverse osmosis system. Overall the study highlights the utility of analysing industrial machinery, such as reverse osmosis must concentration systems, from a life cycle analysis perspective, that can bring about not only environmental sustainability improvements but also technical and economic developments.

Eco-rating Methodologies for Private Cars: Driving Cycle Influence

Several environmental vehicle rating tools have been developed in order to promote the purchase and the use of greener cars. However those were developed/applied at a regional/country specific level. There is a need to develop a broader methodology that can be applied in a multi-country perspective for the assessment of the environmental rating of vehicles with alternative types of fuels as well as different types of drivetrain, such as electric, hybrid, plug-in hybrid and fuel cell hybrid. The environmental indicators usually relates to greenhouse gas emissions (GHG), air pollutants emissions (HC, CO, NOx, PM, SOx) and noise levels. US rating methodology developed by ACEEE is guided by Life Cycle Analysis (LCA), but disregards noise impacts (scores vehicles from zero to 100 (best)). EcoScore Belgian methodology adopts a LCA perspective, disregarding the materials of vehicle impact, but giving some importance to the noise impact (scores from zero to 100(best)). The German Verkehrsclub Deutschland's (VCD) current rating system does not purport to be an LCA, and it has been modified based on evolving views about the importance of various automobile impacts. VCD scores from 0 to 10 (best). It considers impacts in nature both from CO2 (vehicle manufacturer information) and pollutants (European Standards), in human health from pollutants, also considers noise. Australian Green Vehicle Guide (GVG) rating methodology considers only usage stage, giving zero to 10(best) points to GHG and air pollutants, disregarding noise. The overall rating is based on the sum of the air pollution and greenhouse ratings (zero to five star (best)). For the vehicle in-use emissions usually a non-realistic, standard, driving cycle is used and again differs from country to country, despite aiming at representing urban and extra-urban driving.This paper presents the application of the revised methodologies to existent alternative vehicle technologies, pure electric vehicle (Nissan Leaf), gasoline hybrid (Toyota Prius), plug-in hybrid (Toyota Prius), conventional gasoline (VW Beetle TSI), conventional diesel (VW Golf 2.0 Bluemotion), where the urban and extra-urban driving is considered in the same fashion at a multi-country level. Preliminary results of the methodologies rank highly Honda FCX Clarity and Nissan Leaf. Conventional vehicles occupy bottom places in the rankings. The influence of the driving cycles is discussed.

To recycle, or not to recycle, that is the question: Insights from life-cycle analysis

Abstract

Lifecycle impacts of natural gas to hydrogen pathways on urban air quality

In this paper we examine the potential air quality impacts of hydrogen transportation fuel from a lifecycle analysis perspective, including impacts from fuel production, delivery, and vehicle use. We assume that hydrogen fuel cell vehicles are introduced in a specific region, Sacramento County, California. We consider two levels of market penetration where 9% or 20% of the light duty fleet are hydrogen fuel cell vehicles. The following three natural gas to hydrogen supply pathways are assessed in detail and compared in terms of emissions and the resulting changes in ambient air quality: (1) onsite hydrogen production; (2) centralized hydrogen production with gaseous hydrogen pipeline delivery systems; and (3) centralized hydrogen production with liquid hydrogen truck delivery systems. All the pathways examined use steam methane reforming (SMR) of natural gas to produce hydrogen. The source contributions to incremental air pollution are estimated and compared among hydrogen pathways. All of the hydrogen pathways result in extremely low contributions to ambient air concentrations of NO x , CO, particulates, and SO x , typically less than 0.1% of the current ambient pollution for both levels of market penetration. Among the hydrogen supply options, it is found that the central SMR with pipeline delivery systems is the lowest pollution option available provided the plant is located to avoid transport of pollutants into the city via prevailing winds. The onsite hydrogen pathway is comparable to the central hydrogen pathway with pipeline systems in terms of the resulting air pollution. The pathway with liquid hydrogen trucks has a greater impact on air quality relative to the other pathways due to emissions associated with diesel trucks and electricity consumption to liquefy hydrogen. However, all three hydrogen pathways result in negligible air pollution in the region.