Carbon Dioxide Equivalent Emissions Research Articles

Preparation of cleaner one-part geopolymer by investigating different types of commercial sodium metasilicate in China

One-part geopolymers prepared by powder activators, similar to Portland cement in cast-in-situ application, are promising building materials due to the relatively slighter embodied environmental impact. There are three types of commercial sodium metasilicate powders in the China market, and they are Na2SiO3-anhydrous/NS0, Na2SiO3·5H2O/NS5 and Na2SiO3·9H2O/NS9, respectively. This study employed ultra-fine fly ash sinking beads (FASB) and ground granulated blast furnace slag (GGBS) as precursor materials to analyze the influences of NS0, NS5 and NS9 on the properties, microstructure and environmental impact of one-part geopolymer by measuring and characterizing compressive strength, porosity, reaction heat release, geopolymerization products and carbon dioxide equivalent (CO2-e) emission. The experimental results indicate that NS0 has the most rapid and effective activated effect in both single GGBS and GGBS-FASB composites. The strength of geopolymer activated with NS0 is the highest, followed by that with NS9, and followed by that with NS5. The products are mainly gelatinous phases, and the gels in NS0 and NS9 activated geopolymers are better geopolymerized than those in NS5 activated geopolymer, which is proved to be responsible for the difference in macro-performance. The evaluations of the cost and CO2-e emission per MPa of one-part geopolymer demonstrate that NS0 and NS9 are much cheaper and cleaner than NS5 for preparing one-part geopolymer. The embodied CO2 indexes of NS0 and NS9 activated single GGBS are only about 26.5% and 34.0% of that of ordinary Portland cement. This study not only partially explains the reasons for the different properties of one-part geopolymer activated by different types of sodium metasilicate, but also provides a guidance for preparing one-part geopolymer with reasonable cost and slight environmental impact.

Global Warming Potential of CH4 uptake and N2O emissions in saline–alkaline soils

The expansion of soil salinization area has become a great challenge for the reduction of greenhouse gases in fragile ecological environments. A high saline–alkaline soil sample, S1, with electrical conductivity (EC) of 2.60 dS m−1, and a low saline–alkaline soil sample, S2, with EC of 0.74 dS m−1, from the Hetao Irrigation District of Inner Mongolia were studied using the static opaque chamber method in a field in situ observation test that lasted 3 y (2014–2016). The 3-y study was conducted with sunflower crops in intensively managed saline–alkaline soil cropping systems in Northwest China to examine the effects of salt and alkali on Global Warming Potential (GWP) after accounting for carbon dioxide (CO2) equivalent emissions from methane (CH4) uptake and nitrous oxide (N2O) emissions. Results indicated that high saline–alkaline soil significantly increased Global Warming Potential, with obvious differences in CH4 uptake and N2O emissions as compared to low saline–alkaline soil. The annual cumulative uptake of CH4 for 2014, 2015, and 2016 was estimated at 150.0 mg m−2, 119.6 mg m−2, and 99.9 mg m−2, respectively, for the low saline–alkaline soil. Compared with the low saline–alkaline soil, the high saline–alkaline soil significantly decreased the cumulative uptake of CH4 by 27%, 28%, and 19% for 2014, 2015, and 2016, respectively. The annual cumulative emissions of N2O for 2014, 2015, and 2016 were estimated at 180.6 mg m−2, 167.6 mg m−2, and 118.2 mg m−2, respectively, for the low saline–alkaline soil. Compared with the low saline–alkaline soil, the high saline–alkaline soil significantly increased the cumulative emissions of N2O by 19%, 26%, and 45% for 2014, 2015, and 2016, respectively. Overall, compared with the low saline–alkaline soil, the high saline–alkaline soil significantly increased GWP from CH4 uptake and N2O emissions by 20%, 30%, and 50% in 2014, 2015, and 2016, respectively. Our findings suggest that mitigating the GWP of saline–alkaline soil can be achieved by remediating the soil.

The carbon footprint of active sport participants

Researchers examining carbon dioxide-equivalent emissions (carbon footprint) in sport have focused on sport events and, to a lesser extent, sport teams, but provided only average or aggregate values. The author takes the perspective of active sport participants and considers the heterogeneity of individual sport participation behavior. Using online surveys, adult active sport participants (n = 6537) in 20 different sports with main residence in Germany were asked to report their sport-travel behavior in 2015, including traveling in the context of regular (weekly) activity, sport competitions/tournaments, league games, day trips, and training camps/vacations. Annual carbon footprints were estimated using information about travel distances and transportation means. The results revealed an average annual carbon footprint of 844 kg of carbon dioxide-equivalent emissions, with individual sports producing more emissions than team/racket sports. Participants in nature sports had the highest emission levels. Regression analyses revealed that environmental consciousness significantly reduced carbon footprint in individual sports, but not in team/racket and nature sports, supporting the existence of an environmental value-action gap. Activity years, club membership, weekly exercise hours, performance level, and income were mainly positively associated with annual carbon footprint, while gender was insignificant. The findings have implications for policy makers and managers in sport associations and clubs.

Initial evaluation methodology and case studies for life cycle impact of permeability of permeable pavements

Abstract In recent years, urban flooding has occurred frequently in different cities in China. This has caused huge economic and environmental damages. As one of the main elements in the concept of sponge city – a potential solution to this problem – permeable pavements have attracted great attentions. This new technology has the ability to mitigate urban flooding effectively and it also provides other environmental benefits. Life Cycle Assessment (LCA) is a newly developed evaluation approach that can be applied to estimate the environmental impacts of pervious pavements in the entire life cycle. This study propose a basic model which can be applied to both permeable asphalt pavements and permeable concrete pavements to evaluate their environmental impacts. The impacts of this technology are investigated on urban flooding, water recycling and water purification. Then a comparison between permeable asphalt pavement and dense-graded asphalt pavement is conducted for a typical four-lane secondary road. Results indicate that in 10 km of the modeled road, 49TJ of energy consumption, 6700 t of equivalent carbon dioxide emissions, 0.1 t of lead emissions and 1 t of zinc emissions can be avoided if the permeable pavements is used. Moreover, the most significant reduction in energy consumption, GHG emissions, lead emissions and zinc emissions occurs in the use phase.

Modelling the exergy behavior of São Paulo State in Brazil

Abstract Exergy analysis was applied to the state of Sao Paulo, Brazil, and exergy efficiencies were obtained for its constituent sectors, the Industrial, Rural, Commercial & Public, Residential and Transportation, from most to least efficient. Overall exergy efficiency was found to be 28.3%, a value which lies within the range of similar studies. To indicate the usefulness of the exergy approach, some measures were tested based on exergy efficiency values. LED lamps to improve sectorial exergy efficiencies by lowering consumption, but the overall impact is low. Solar water heaters can mitigate the mismatch in quality between supply and demand, in the Residential sector, by harnessing power from an inexhaustible renewable source. For the Transportation sector, with technological constraints regarding similar internal combustion engine efficiencies, improvements were tested on a total carbon dioxide equivalent emission. Gasoline substitution for ethanol was the better option, and fleet electrification produced a wide range of results due to battery production and variability in emission factors from the Utility sector.

Potential of reduction in carbon dioxide equivalent emissions via energy efficiency for a textile factory

Today, one of the most important issues in the world is that the concentration of carbon dioxide in the atmosphere which is the fundamental reason for global warming exhibits a severe increase in every passing year. It is a general view that the most crucial step to succeed in mitigation carbon emissions is the reduction of energy consumption. In this study, production and energy consumption data only for year 2016 of an industrial textile factory in Turkey were employed to explore carbon emission mitigation potential through energy efficiency. The research consists of three steps listed as i) data collection, ii) data processing and iii) data evaluation. Energy saving potential of the industry has been determined with the help of the energy consumption relations developed depending on data obtained from the factory by calculating the target energy consumption for year 2017 and beyond. Also, the amount of reduction in carbon emissions stemming from the amount of fuel saved thanks to energy efficiency has been calculated. Energy saving potential for 2017 and later years was found 98.9 TOE per year and also due to these saving, the amount of the reduction in CO2 emissions of the factory will totally be 2.75 million-tones CO2 in comparison to year 2016. It is also seen that financial savings will be approximately € 28,646.06 for the year 2017 and later years.

Public health air pollution impacts of pathway options to meet the 2050 UK Climate Change Act target: a modelling study

BackgroundThe UK’sClimate Change Act 2008(CCA; Great Britain.Climate Change Act 2008. Chapter 27. London: The Stationery Office; 2008) requires a reduction of 80% in carbon dioxide-equivalent emissions by 2050 on a 1990 base. This project quantified the impact of air pollution on health from four scenarios involving particulate matter of ≤ 2.5 µm (PM2.5), nitrogen dioxide (NO2) and ozone (O3). Two scenarios met the CCA target: one with limited nuclear power build (nuclear replacement option; NRPO) and one with no policy constraint on nuclear (low greenhouse gas). Another scenario envisaged no further climate actions beyond those already agreed (‘baseline’) and the fourth kept 2011 concentrations constant to 2050 (‘2011’).MethodsThe UK Integrated MARKAL–EFOM System (UKTM) energy system model was used to develop the scenarios and produce projections of fuel use; these were used to produce air pollutant emission inventories for Great Britain (GB) for each scenario. The inventories were then used to run the Community Multiscale Air Quality model ‘air pollution model’ to generate air pollutant concentration maps across GB, which then, combined with relationships between concentrations and health outcomes, were used to calculate the impact on health from the air pollution emitted in each scenario. This is a significant improvement on previous health impact studies of climate policies, which have relied on emissions changes. Inequalities in exposure in different socioeconomic groups were also calculated, as was the economic impact of the pollution emissions.ResultsConcentrations of NO2declined significantly because of a high degree of electrification of the GB road transport fleet, although the NRPO scenario shows large increases in oxides of nitrogen emissions from combined heat and power (CHP) sources. Concentrations of PM2.5show a modest decrease by 2050, which would have been larger if it had not been for a significant increase in biomass (wood burning) use in the two CCA scenarios peaking in 2035. The metric quantifying long-term exposure to O3is projected to decrease, while the important short-term O3exposure metric increases. Large projected increases in future GB vehicle kilometres lead to increased non-exhaust PM2.5and particulate matter of ≤ 10 µm emissions. The two scenarios which achieve the CCA target resulted in more life-years lost from long-term exposures to PM2.5than in the baseline scenario. This is an opportunity lost and arises largely from the increase in biomass use, which is projected to peak in 2035. Reduced long-term exposures to NO2lead to many more life-years saved in the ‘CCA-compliant’ scenarios, but the association used may overestimate the effects of NO2itself. The more deprived populations are estimated currently to be exposed to higher concentrations than those less deprived, the contrast being largest for NO2. Despite reductions in concentrations in 2050, the most socioeconomically deprived are still exposed to higher concentrations than the less deprived.LimitationsModelling of the atmosphere is always uncertain; we have shown the model to be acceptable through comparison with observations. The necessary complexity of the modelling system has meant that only a small number of scenarios were run.ConclusionsWe have established a system which can be used to explore a wider range of climate policy scenarios, including more European and global scenarios as well as local measures. Future work could explore wood burning in more detail, in terms of the sectors in which it might be burned and the spatial distribution of this across the UK. Further analyses of options for CHP could also be explored. Non-exhaust emissions from road transport are an important source of particles and emission factors are uncertain. Further research on this area coupled with our modelling would be a valuable area of research.FundingThe National Institute for Health Research Public Health Research programme.

Does carbon pricing reduce air travel? Evidence from the Australian ‘Clean Energy Future’ policy, July 2012 to June 2014

Aviation emissions are an important contributor to global climatic change. As growth in travel demand continues to outstrip improvements in the fuel efficiency of air travel, the aviation contribution to climate change is likely to grow substantially. Consequently, measures that effectively reduce travel demand are required if atmospheric carbon concentrations are to be limited. The efficacy of the Australian Clean Energy Future policy which placed a $23.00AUD (FY 2012) to $24.15 AUD (FY 2013) per tonne levy on carbon-dioxide equivalent emissions from July 2012 to June 2014 is tested. Specifically, time-series regression is used to estimate the effect of this carbon price policy on the level of domestic passenger kilometres flown in Australia, while adjusting for costs of production (i.e. fuel and labour costs), economic activity (i.e. gross domestic product), competitive effects (i.e. airline capacity), and exogenous shocks. There was no evidence that the carbon price reduced the level of domestic aviation in Australia. Carbon pricing measures may have to be levied at a greater rate to affect behavioural change, particularly given the limited potential for future aviation efficiency gains.

Carbon Footprint of Recycled Aggregate Concrete

Carbon footprint is one of the most widely used tools for assessing the environmental impacts of the production and utilization of concrete as well as of the components derived from it, representing the amount of carbon dioxide and other greenhouse gases associated with this product, expressed as CO2 equivalents. In this paper, carbon footprint was used to compare the environmental performance in the production phase of a concrete made with both recycled and crushed virgin limestone aggregates, using a life cycle analysis methodological approach. Research outcomes revealed, as expected, that carbon dioxide equivalent emissions decreased slightly as the use of recycled aggregates increased. Emissions for concrete with 0.5 w/c were between 347 and 351 kg of CO2-e/m3. It was also corroborated that cement is the material with the greatest influence on greenhouse gas emission generation in the concrete’s production phase, regardless of the use of recycled or virgin aggregates.

Potential for offsetting diamond mine carbon emissions through mineral carbonation of processed kimberlite: an assessment of De Beers mine sites in South Africa and Canada

De Beers kimberlite mine operations in South Africa (Venetia and Voorspoed) and Canada (Gahcho Kue, Victor, and Snap Lake) have the potential to sequester carbon dioxide (CO2) through weathering of kimberlite mine tailings, which can store carbon in secondary carbonate minerals (mineral carbonation). Carbonation of ca. 4.7 to 24.0 wt% (average = 13.8 wt%) of annual processed kimberlite production could offset 100% of each mine site’s carbon dioxide equivalent (CO2e) emissions. Minerals of particular interest for reactivity with atmospheric or waste CO2 from energy production include serpentine minerals, olivine (forsterite), brucite, and smectite. The most abundant minerals, such as serpentine polymorphs, provide the bulk of the carbonation potential. However, the detection of minor amounts of highly reactive brucite in tailings from Victor, as well as the likely presence of brucite at Venetia, Gahcho Kue, and Snap Lake, is also important for the mineral carbonation potential of the mine sites.

Comparing End-Use Potential for Industrial Food-Waste Sources

Abstract Approximately one quarter of the global edible food supply is wasted. The drivers of food waste can occur at any level between production, harvest, distribution, processing, and the consumer. While the drivers vary globally, the industrialized regions of North America, Europe, and Asia share similar situations; in each of these regions the largest loss of food waste occurs with the consumer, at approximately 51% of total waste generated. As a consequence, handling waste falls on municipal solid waste operations. In the United States, food waste constitutes 15% of the solid waste stream by weight, contributes 3.4 × 107 t of carbon dioxide (CO2) equivalent emissions, and costs 1.9 billion USD in disposal fees. The levels of carbon, nutrients, and moisture in food waste make bioprocessing into higher value products an attractive method for mitigation. Opportunities include extraction of nutraceuticals and bioactive compounds, or conversion to a variety of volatile acids—including lactic, acetic, and propionic acids—that can be recovered and sold at a profit. The conversion of waste into volatile acids can be paired with bioenergy production, including hydrogen or biogas. This present review compares the potential for upgrading industrial food waste to either specialty products or methane. Higher value uses of industrial food waste could alleviate approximately 1.9 × 108 t of CO2 equivalent emissions. As an example, potato peel could be upgraded to lactic acid via fermentation to recover 5600 million USD per year, or could be converted to methane via anaerobic digestion, resulting in a revenue of 900 million USD per year. The potential value to be recovered is significant, and food-waste valorization will help to close the loop for various food industries.

The Lancet Countdown on health benefits from the UK Climate Change Act: a modelling study for Great Britain

Climate change poses a dangerous and immediate threat to the health of populations in the UK and worldwide. We aimed to model different scenarios to assess the health co-benefits that result from mitigation actions. In this modelling study, we combined a detailed techno-economic energy systems model (UK TIMES), air pollutant emission inventories, a sophisticated air pollution model (Community Multi-scale Air Quality), and previously published associations between concentrations and health outcomes. We used four scenarios and focused on the air pollution implications from fine particulate matter (PM2·5), nitrogen dioxide (NO2) and ozone. The four scenarios were baseline, which assumed no further climate actions beyond those already achieved and did not meet the UK's Climate Change Act (at least an 80% reduction in carbon dioxide equivalent emissions by 2050 compared with 1990) target; nuclear power, which met the Climate Change Act target with a limited increase in nuclear power; low-greenhouse gas, which met the Climate Change Act target without any policy constraint on nuclear build; and a constant scenario that held 2011 air pollutant concentrations constant until 2050. We predicted the health and economic impacts from air pollution for the scenarios until 2050, and the inequalities in exposure across different socioeconomic groups. NO2 concentrations declined leading to 4 892 000 life-years saved for the nuclear power scenario and 7 178 000 life-years saved for the low-greenhouse gas scenario from 2011 to 2154. However, the associations that we used might overestimate the effects of NO2 itself. PM2·5 concentrations in Great Britain are predicted to decrease between 42% and 44% by 2050 compared with 2011 in the scenarios that met the Climate Change Act targets, especially those from road traffic and off-road machinery. These reductions in PM2·5 are tempered by a 2035 peak (and subsequent decline) in biomass (wood burning), and by a large, projected increase in future demand for transport leading to potential increases in non-exhaust particulate matter emissions. The potential use of biomass in poorly controlled technologies to meet the Climate Change Act commitments would represent an important missed opportunity (resulting in 472 000 more life-years lost from PM2·5 in the low-greenhouse gas scenario and 1 122 000 more life-years lost in the nuclear power scenario from PM2·5 than the baseline scenario). Although substantial overall improvements in absolute amounts of exposure are seen compared with 2011, these outcomes mask the fact that health inequalities seen (in which socioeconomically disadvantaged populations are among the most exposed) are projected to be maintained up to 2050. The modelling infrastructure created will help future researchers explore a wider range of climate policy scenarios, including local, European, and global scenarios. The need to strengthen the links between climate change policy objectives and public health imperatives, and the benefits to societal wellbeing that might result is urgent. National Institute for Health Research.

Nitrogen fertilizer in combination with an ameliorant mitigated yield-scaled greenhouse gas emissions from a coastal saline rice field in southeastern China.

Coastal saline rice fields play an increasingly important role in rice production and associated greenhouse gas (GHG) emissions. However, few studies investigated the influences of nitrogen (N) fertilizer and soil ameliorant on GHG emissions simultaneously in this region. Thus, a field experiment was established to study the effects of different N fertilizers and soil ameliorant on global warming potential (GWP) and yield-scaled GHG intensity (GHGI) after accounting for carbon dioxide (CO2) equivalent emissions of methane (CH4) and nitrous oxide (N2O), agrochemical inputs, and farm operations along with agronomic nitrogen use efficiency (NUE) during the rice season of 2016 in a coastal saline paddy in Lianyungang, China. The experiment was initiated with four N treatments (N0, no N; Nu, urea; Nm, organic-inorganic mixed fertilizer; Nw, organic fertilizer made from wheat straw) and two ameliorant (A) treatments (A0, no ameliorant; A1, 22.5kgha-1 ameliorant). The results showed that three N fertilizers significantly increased the CH4 emissions, N2O emissions, GWP, and grain yield by 42.2% (p < 0.001), 57.1% (p < 0.001), 49.8% (p < 0.001), and 58.9% (p < 0.001), respectively. NuA1, NmA1, and NwA1 treatments obviously reduced the yield-scaled GHGI by 21.3%, 16.3%, and 12.4%, respectively, relative to the corresponding NuA0, NmA0, and NwA0 treatments. Overall, although three N fertilizers would increase the GWP, combining an ameliorant amendment with N fertilizer can effectively reduce the yield-scaled GHGI and meanwhile increase the grain yield, particularly the NmA1 strategy.

Teardown Index: Impact of property values on carbon dioxide emissions of single family housing in Vancouver

Buildings are significant drivers of climate change, generating one third of global greenhouse gas emissions. When new buildings are constructed to high performance standards, increased rates of building replacement spurred by rising property values can raise the operating efficiency of building stocks. However, it can take years before the embodied greenhouse gas emissions associated with new construction are offset by more efficient operations. This paper calculates the carbon dioxide emission payback period of newly constructed efficient single family homes in Vancouver, British Columbia. The average carbon dioxide emission payback period of 168 years for a typical high efficiency new home renders it unlikely that emission savings will be realized before it is replaced. A statistical model called the Teardown Index is presented, which indicates that replacing older poorly performing homes with new high efficiency homes in Vancouver will result in 1.3–2.8 million tonnes of additional carbon dioxide equivalent emissions between 2017 and 2050. For each percent increase to the compound annual growth rate of property values, an additional 150 thousand tonnes of CO2e will be released between 2017-2050. The findings suggest that current policies aimed at reducing emissions through new high efficiency buildings should be reconsidered.

Analysis of greenhouse gas emissions in electricity systems using time-varying carbon intensity

Abstract Greenhouse gas (GHG) emissions from electricity generation are generally assessed using a yearly average carbon intensity (in carbon dioxide equivalent emissions per unit of energy). This masks the variability of emissions associated with different forms of generation over different timescales. Variability is a characteristic of electricity systems with high levels of renewable generation, where fossil fuels are typically used to meet any shortfall in supply. In this paper we argue that quantification of the time variability of carbon intensity is necessary to understand the detailed patterns of carbon emissions in electricity systems, particularly as future systems are likely to increasingly rely on a mix of time-variable generation types such as wind, hydro and solar. We analysed the time-varying carbon intensity of New Zealand's electricity sector, which has approximately 80% renewable generation. In contrast to many other nations, we found that carbon intensity did not consistently follow daily peak demand, and was only weakly correlated with demand. This result, and the finding that carbon intensity has significant seasonal variation, stems from the dominance of hydro (albeit with limited storage capacity) in New Zealand's generation mix. Further investigation of the operating regimes of the fossil fuel generators, using time-varying analysis, indicates that New Zealand's electricity system is sub-optimal from a GHG emission perspective, with more coal generation than would seem to be required. Two policy measures, which also generalize to other countries, are proposed to address this issue: (i) the creation of an electricity capacity market – providing revenue for standby fossil fuel generation capacity without the need for continual generation; (ii) use of time-varying carbon intensity to inform demand-side measures and decisions about new renewable generation.

Life cycle assessment of different physical-chemical and biological technologies for biogas desulfurization in sewage treatment plants

Abstract Biogas desulfurization can be carried out by physical-chemical or biological technologies. Biological technologies are generally described as more environmentally friendly than physical-chemical techniques, although it is difficult to find studies in which the associated environmental burdens are compared. Therefore, the aim of the work described here was to perform a life cycle assessment to compare the environmental impact of four common desulfurization technologies for hydrogen sulfide removal from biogas produced in sewage treatment plants. The desulfurization technologies studied were aerobic biotrickling filtration, anoxic biotrickling filtration, caustic chemical scrubbing and adsorption on impregnated activated carbon. The environmental assessment was extended with a Capital Expenditures (CAPEX) and Operational Expense (OPEX) analysis. Furthermore, an extra scenario (no desulfurization with biogas combustion) was compared with biogas desulfurization by aerobic biofiltration coupled to energy valorization (best-case treatment scenario). Results indicate that biological technologies are much more favorable in most environmental impact categories than physical-chemical technologies and, as expected, are more favorable than the non-treatment scenario. In all desulfurization technologies the most contributing stage to the total environmental burdens was the daily desulfurization operation. The chemical scrubber was the worst scenario except for the “Climate Change”. In terms of the “Climate Change” (carbon dioxide equivalent emission), aerobic and anoxic desulfurization would emit 13.9 and 18.7 kg CO2 kg−1 S-H2S treated, respectively. The anoxic process could be improved to emit only 7.2 kg CO2 kg−1 S-H2S treated if the nitrate source was produced in a nitrification reactor built at the sewage treatment plant. Caustic chemical scrubber desulfurization and impregnated activated carbon desulfurization would emit 30.0 and 42.1 kg CO2 kg−1 S-H2S treated, respectively. To all impact categories, the contribution of sulfur compounds was less than 5%. The aerobic biotrickling filtration had the lower environmental impacts. However, the anoxic biotrickling filtration was the best approach if a nitrification reactor was already on-site.

Fermentation and distillation of cheese whey: Carbon dioxide-equivalent emissions and water use in the production of whey spirits and white whiskey

Whey disposal can be both an environmental and economic challenge for artisanal creameries. Lactose in whey can be fermented to produce ethanol and subsequently distilled. The objective of this study was to use a process-based life cycle analysis to compare carbon dioxide-equivalent (CO2e) emissions and water usage associated with the artisanal or craft production of clear, unaged spirits using whey or malted barley as fermentation substrate. Differences in production were assessed based on key process differences: energy used, water used, distillation by-product disposal, and mass of CO2 produced during fermentation. For this study, whey was assumed removed from the artisanal creamery waste stream. Quantifiable differences were evaluated per 750-mL (45% alcohol by volume) functional unit and expressed as mass-equivalent CO2 emissions (kg of CO2e) and mass of water (kg) used. The CO2e emissions and water usage were quantified using published data, thermodynamic calculations, and mass-balance calculations for a hypothetical distillation system. The process-based life cycle analysis estimated that distillation of fermented whey reduced overall CO2e emissions by 8.4 kg per functional unit and required 0.44 kg less water added into the production process compared with production of a similar clear, unaged spirit using malted barley as substrate. Our preliminary analysis suggests that conversion to distilled whey spirit is a more environmentally responsible approach compared with landfill disposal of whey.

An analytical model to investigate the economic and environmental benefits of a supply chain resource-sharing scheme based on collaborative consolidation centres

This study evaluates the cost and carbon dioxide-equivalent emissions of different supply chain configurations to determine when suppliers should move to a greener resource-sharing scheme. We build an analytical model based on a case study of a retailer that has developed a resource-sharing initiative introducing collaborative consolidation centres (CCC) between its suppliers and its warehouses (WH). We compare the costs and carbon dioxide-equivalent emissions of using a pair of CCCs with direct delivery to twenty WHs. Our parameters include the distances between suppliers, CCCs, and WHs, in addition to the volumes delivered. This model determines when there should be a switch to the CCC system. We also compare the actual CCC locations with better alternatives, the centres of gravity of the regions. On a real cost basis, economic gains, but not environmental ones, occur, highlighting a need for alternative models for optimal locations, which would include economic and environmental constraints.

Reuse of honey jars for healthier bees: Developing a sustainable honey jars supply chain through the use of LCA

Abstract This study aims at improving the environmental sustainability of an existing honey production supply chain, pursuing the Sustainable Supply Chain Management philosophy and the Life Cycle Assessment principles. Focusing the attention on the packaging stage and, in particular, on the most commonly used honey packaging solution, the glass jar, this study assesses the environmental burdens associated with its manufacturing, distribution and final disposal. Once the “AS-IS” honey packaging situation of an Italian province has been analyzed, parallel packaging reuse scenarios and redistribution supply chains are modelled, involving different levels of collaboration between the honey producers and the provincial beekeeping consortium. These scenarios have been then compared to the AS-IS situation, taking into account five environmental factors important for the honeybee's survival: the carbon dioxide equivalent emission, the triethylene glycol equivalent emissions into water and soil, the sulfur dioxide equivalent emission into air and the m2 equivalent reduction of organic arable land per year. The outcomes show how the adoption of a packaging reuse policy together with a producer collaboration policy could bring, in five years, to reduce those factors on average of 16% (with a 10% packaging reuse rate), up to more than 70% (with an 85% packaging reuse rate).

Multiobjective optimization for lifecycle cost, carbon dioxide emissions and exergy of residential heat and electricity prosumers

A key element to reach sustainability in the built environment is reducing the need to compromise between performance and cost-optimality. Particularly, conversion and/or exchange of surplus energy from on-site generation components can offer opportunities to increase the overall system profitability and enhance its performance. This study addresses the cost-optimality, operational carbon dioxide emissions and exergetic performance of a single-family building with bidirectional heat and electricity exchange. Through multiobjective optimization, it compares various system configurations that have on-site heat and electricity generation components. The results show that, for systems with over ∼4.3 kW onsite electricity generation capacity, driving a ground-source heat pump with surplus electricity to obtain heat, and export it to a district heating grid, offers optimal solutions for lifecycle costs and operational equivalent carbon dioxide emissions. Under the studied context, heat export from a ground-source heat pump driven by surplus electricity leads to nearly a fivefold increase in monetary income per unit of exported energy and to a fivefold increase in operational equivalent carbon dioxide emissions compensation. Considerable drawbacks of this are the lower exergy content and mobility of heat, compared to electricity, though these can be alleviated if the heat is used for heating purposes in nearby buildings.