Greenhouse Gas Emission Savings Research Articles

Global Potential for Biomethane Production with Carbon Capture, Transport and Storage up to 2050

Biomass in combination with carbon capture and storage (CCS) is one of few options that make a reduction of global CO2 concentration in the atmosphere possible. This option is likely to be required to meet climate targets. This study shows the global potential for combining bio-energy conversion with CCS (BE-CCS) up to 2050. The assessment focuses on two BE-CCS routes for the production of biomethane, based on gasification and anaerobic digestion. Routes for the production of power and liquid fuels have been addressed in an earlier study by IEAGHG. For the two routes the technical and economic potential was analysed. The results show that deployment of the global technical potential can result in negative greenhouse gas emissions (GHG) up to 3.5 Gt CO2-eq. on an annual basis in 2050. Including avoided emissions by replacing natural gas, the annual greenhouse gas emission savings could add up to almost 8 Gt of CO2-eq in 2050. The economic potential reaches up to 0.8 Gt of negative GHG emissions when assuming a CO2 price of 50 €/tonne.

Reducing greenhouse gas emissions with urban agriculture: A Life Cycle Assessment perspective

The production and supply of food currently accounts for 20–30% of greenhouse gas (GHG) emissions in the UK and the government and nongovernmental organisations are seeking to reduce these environmental burdens. Local authorities all over UK establish community farms with the aim to produce more sustainable food for citizens. This study used environmental Life Cycle Assessment (LCA) to quantify the potential savings of food-related GHG emissions that may be achieved with the establishment of an urban community farm, based on a case study recently found in the London Borough of Sutton. The work identified elements of the farm design that require the greatest attention to maximise these savings. The greatest reductions can be achieved by selecting the right crops: (i) providing the highest yields in local conditions and (ii) usually produced in energy-intensive greenhouses or air-freighted to UK from outside Europe. Implications from further development of the farm on the local, unused land were examined, taking into account market requirements. This showed that land used on an urban fringe for food production could potentially reduce greenhouse gas emissions in Sutton by up to 34tCO2eha−1a−1. Although the percentage of this reduction in total diet emissions is relatively low, the result exceeds carbon sequestration rates for the conventional urban green space projects, such as parks and forests.

Bioplastics science from a policy vantage point

Society is fundamentally ambivalent to the use of plastics. On the one hand, plastics are uniquely flexible materials that have seen them occupy a huge range of functions, from simple packing materials to complex engineering components. On the other hand, their durability has raised concerns about their end-of-life disposal. When that disposal route is landfill, their invulnerability to microbial decomposition, combined with relatively low density and high bulk, means that plastics will occupy increasing amounts of landfill space in a world where available suitable landfill sites is shrinking. The search for biodegradable plastics and their introduction to the marketplace would appear to be a suitable amelioration strategy for such a problem. And yet the uptake of biodegradable plastics has been slow. The term biodegradable itself has entered public controversy, with accidental and intended misuse of the term; the intended misuse has led to accusations and instances of 'greenwashing'. For this and other reasons standards for biodegradability and compostability testing of plastics have been sought. An environmental dilemma with more far-reaching implications is climate change. The need for rapid and deep greenhouse gas (GHG) emissions cuts is one of the drivers for the resurgence of industrial biotechnology generally, and the search for bio-based plastics more specifically. Bio-based has come to mean plastics based on renewable resources, but this need not necessarily imply biodegradability. If the primary purpose is GHG emissions savings, then once again plastics durability can be a virtue, if the end-of-life solution can be energy recovery during incineration or recycling. The pattern of production is shifting from the true biodegradable plastics to the bio-based plastics, and that trend is likely to persist into the future. This paper looks at aspects of the science of biodegradable and bio-based plastics from the perspective of policy advisers and makers. It is often said that the bioplastics suffer from a lack of a favourable policy regime when compared to the wide-ranging set of policy instruments that are available on both the supply and demand side of biofuels production. Some possible policy measures are discussed.

Glacial geomorphology in Småland, SE Sweden

Sustainable diets, in particular vegetarianism, are often promoted as effective measures to reduce our environmental footprint. Yet, few conclusions take full-scale behavioral changes into consideration. This can be achieved by calculating the indirect environmental rebound effect related to the re-spending of expenditure saved during the initial behavioral shift. This study aims to quantify the potential energy use and greenhouse gas emission savings, and most likely rebound effects, related to an average Swedish consumer's shift to vegetarianism. Using household budget survey data, it estimates Engel curves of 117 consumption goods, derives marginal expenditure shares, and links these values to environmental intensity indicators. Results indicate that switching to vegetarianism could save consumers 16% of the energy use and 20% of the greenhouse gas emissions related to their dietary consumption. However, if they re-spend the saved income according to their current preferences, they would forego 96% of potential energy savings and 49% of greenhouse gas emission savings. These rebound effects are even higher for lower-income consumers who tend to re-spend on more environmentally intensive goods. Yet, the adverse effect could be tempered by purchasing organic goods or re-spending the money on services. In order to reduce the environmental impact of consumption, it could thus be recommended to not only focus on dietary shifts, but rather on the full range of consumer expenditure.

Emissions reduction and economic implications of renewable energy market penetration of power generation for residential consumption in the MENA region

This paper examines the implications of renewable energy (RE) deployment in power generation for residential consumption in the Middle East and North Africa (MENA) region under various RE penetration targets. A comparative assessment revealed a great heterogeneity among countries with Turkey dominating as the highest emitter. At the sub-regional level, the Middle East sub-region contributes more than double the GHG emissions estimated for the Gulf and North Africa sub-regions with all sub-regions achieving reductions in the range of 6–38% depending on the RE target penetration and promising up to 54% savings on investment excluding positive externalities associated with the offset of greenhouse gas (GHG) emissions savings.

Innovations in papermaking: An LCA of printing and writing paper from conventional and high yield pulp

Pulp and paper industry is facing challenges such as resource scarcity and greenhouse gas (GHG) emissions. The objective of this research is to investigate whether the use of new coatings (micro or nano TiO2) and different pulp types could bring savings in wood, energy, GHG emissions and other environmental impacts in comparison with conventional printing and writing paper. We studied three types of pulp, namely i) unbleached virgin kraft pulp, ii) recovered fiber, and iii) high yield virgin chemithermo-mechanical pulp (CTMP). A life cycle assessment (LCA) was conducted from cradle to grave.Applying attributional modeling, we found that wood savings amount to 60% for the nanoparticle coated recovered fiber paper and 35% for the micro TiO2 coated CTMP paper. According to the ReCiPe single score impact assessment method, the new product configurations allow the reduction of the environmental impacts by 10–35% compared to conventional kraft paper.Applying consequential modeling, we found larger energy and GHG emission savings compared to attributional modeling because the saved wood is used for producing energy, thereby replacing fossil fuels. The nanoparticle coated recovered fiber paper offered savings of non-renewable energy use (NREU) by 100% (13GJ/ton paper) and GHG emission reduction by 75% (0.6tonCO2eq./ton paper). Micro TiO2 coated CTMP paper offered NREU savings by 25% (3GJ/ton paper) and savings of GHG emissions by 10% (0.1tonCO2eq./ton paper). The taking into account of all environmental impacts with the ReCiPe single score method leads to comparable results as that of attributional modeling.We conclude that the nanoparticle coated recovered fiber paper offered the highest savings and lowest environmental impacts. However, human toxicity and ecotoxicity impacts of the nanoparticles were not included in this analysis and need further research. If this leads to the conclusion that the toxicity impacts of the nanoparticles are serious, then the CTMP paper with micro TiO2 coating is the preferred option.

Recalculating GHG emissions saving of palm oil biodiesel

In 2010, the Renewable Energy Directive (RED) came into force in the EU and establishes a framework for achieving legally binding greenhouse gas (GHG) emission reductions. Only sustainable biofuels can be counted towards Member State targets. The aim of this paper is to calculate realistic and transparent scenario-based CO2-emission values for the GHG emissions savings of palm oil fuel compared with fossil fuel. Using the calculation scheme proposed by the RED, we derive a more realistic overall GHG emissions saving value for palm oil diesel by using current input and output data of biofuel production (e.g. in South-East Asia). We calculate different scenarios in which reliable data on the production conditions (and the regarding emission values during the production chain) of palm oil diesel are used. Our results indicate values for the GHG emissions savings potential of palm oil biodiesel not only above the 19 % default and 36 % typical value published in RED but also above the 35 % sustainable threshold. Our findings conclude the more accurate GHG emissions saving value for palm oil feedstock for electricity generation to be 52 %, and for transportation biodiesel between 38.5 and 41 %, depending on the fossil fuel comparator. Our results confirm the findings by other studies and challenge the official typical and default values published in RED. As a result, the reliability of the Directive to support the EU’s low-carbon ambitions is being undermined, exposing the EU and commission to charges of trade discrimination and limiting the ability of Member States to achieve their legally binding GHG emission reductions.

Life cycle assessment of eucalyptus short rotation coppices for bioenergy production in southern France

AbstractShort rotation coppices (SRC) are considered prime candidates for biomass production, yielding good‐quality feedstock that is easy to harvest. Besides technical, social and economical aspects, environmental issues are important to be taken into account when developing SRC. Here, we evaluated the environmental impacts of delivering 1 GJ of heat from eucalyptus SRC using life cycle assessment (LCA), based on management scenarios involving different rotations lengths, fertilizer input rates, stem densities and harvest methods. Compared to equivalent fossil chains, all eucalyptus scenarios achieved savings of fossil energy and greenhouse gas (GHG) emissions in the 80–90% range, and had generally lower impacts, except for eutrophication. The 3 year rotation scenario was the most energy and GHG‐intensive, whereas manual felling for the longer rotations resulted in twofold larger photochemical ozone impacts compared to the other scenarios. Transportation of wood chips and fertilization were the top two contributors to the impacts, the latter being more important with the shorter rotation lengths due to the evergreen character of eucalyptus. The possibility of including ecosystem carbon dynamics was also investigated, by translating the temporary sequestration of atmospheric CO2 in the above and belowground biomass of eucalyptus as CO2 savings using various published equivalence factors. This offset the life cycle GHG emissions of heat provision from eucalyptus SRC by 70–400%.

The Effects of Local Biomass Availability and Possibilities for Truck and Train Transportation on the Greenhouse Gas Emissions of a Small-Diameter Energy Wood Supply Chain

The work presents a method of assessing the greenhouse gas (GHG) emissions of forest-based biomass supply chains on a site-specific level. The method includes biomass availability and transportation network assessments based on geographical information system data, and GHG emission assessment based on life-cycle assessment methods. The GHG assessment takes into account distances traveled on the various types of road by trucks. Two case studies are presented, with 720 TJ year−1 of small-diameter energy wood chips delivered to two locations in Finland: Mikkeli and Rovaniemi. In the case studies, possibilities for train transportation from distant supply areas were included. Regarding railway transportation, it was assumed that the end-points have direct railway connections. The case study results show that if direct truck transportation around the plants were supplemented with one trainload per week (230 TJ year−1) from suitably located railway loading points, GHG emission savings of 8 % could be achieved in both cases. The most GHG-efficient supply chains around the railway loading points were found to be based on transportation of loose trees to the loading spots. Because of better biomass availability and better roads, the emissions of the least GHG-emitting supply chain were 9 % lower in Mikkeli’s case than for Rovaniemi. The results indicate that site-specific biomass availability and transportation possibilities should be taken into account in assessment of the GHG emissions of a particular biomass supply chain. Also, if suitable conditions exist, railway transportation offers potential for reduced supply-chain GHG emissions.

Evaluating the energy and carbon reductions resulting from resource-efficient household stock

The nexus of water and energy and greenhouse gas emissions is now well recognised, however, quantifying the energy savings from (hot) water-efficient technologies has been largely based on modelled or assumed consumption data from water use appliances and fixtures. The aim of this paper is to determine water, energy and greenhouse gas emission savings from resource-efficient household stock using empirical water end-use data and detailed stock specifications for homes in Queensland, Australia. Hot water system type is considered with comparisons made between intervention scenarios with and without inclusion of a low energy heating system. The results confirm the significant impact that coal-fired electricity water heating has on total household energy consumption. Further, it appears that substantial savings can be achieved by substituting water (e.g. high star rating appliances) and energy (e.g. solar hot water system) efficient appliances in the home. The findings also suggest that retrofitting cheaper resource-efficient technologies are still an effective means of reducing both water and energy consumption, regardless of hot water system type. Future work in this area is needed to expand the current research outcomes, such as the consideration of all thermal losses from heating systems and the use of empirical energy end-use data.

How digital information services can reduce greenhouse gas emissions

PurposeThe study aims to determine the environmental impact of printed content in libraries and thus to find out how a digital information service can help libraries and institutions play a key role in helping the environment.Design/methodology/approachData were collected and analysed through a combination of environment scan and document analysis, and some mathematical calculations. Comparative data for greenhouse gas (GHG) emissions from printed books and journals in certain countries, and some specific university libraries in Australia and New Zealand are presented. A lifecycle analysis approach is used to identify various factors that are responsible for GHG emissions for printed as well as digital information resources.FindingsThe study found that dematerialisation, i.e. the replacement of printed content with digital information services, can help libraries and institutions to reduce their impact on the environment. However it is also noted that further research is needed to develop benchmarks and comparative data for GHG emissions from print‐based and digital information services.Practical implicationsThe paper provides data relating to the potential savings in GHG emissions that can be achieved through dematerialisation of printed content in libraries. A series of research issues in the area are identified.Originality/valueThe paper opens up a new area of research on the environmental impacts of information services. For the first time raw data on GHG emissions from printed content held in university libraries are calculated.

Assessment of solar assisted air conditioning in Central Queensland's subtropical climate, Australia

Abstract Australia has a very sunny climate, with a very high demand for air conditioning. Implementing solar assisted air conditioning is an ideal option to achieve a high solar fraction which leads to a significant amount of energy and greenhouse gas emission savings. Solar assisted air conditioning systems are environmentally friendly by being constructed in a way that minimises the need for chlorofluorocarbons CFC, Hydro chlorofluorocarbons HCFC or Chlorofluorocarbons HFC refrigerants and by using a low grade thermal renewable energy, therefore, making them energy efficient and environmentally safe. They can be used either as stand-alone systems or with conventional AC, to improve the indoor air quality. Solar cooling is a new and a fast growing technology compared to other fields of solar energy applications. On the other hand most of the current solar cooling applications are demonstration projects in nature; the technologies are advancing yet still need a lot of additional design, planning, development, and research efforts. T now solar assisted air conditioning's main obstacles are the high installation costs, and the lack of knowledge and familiarity with this technology between designers, developers and architects. In this paper a feasibility study is carried out to assess a solar assisted air conditioning system for an office building under three of Queensland's subtropical climates; Rockhampton, Gladstone, and Emerald. The technical aspects of a proposed solar cooling system are investigated. Cooling load profile for a proposed reference building was obtained using TRNSYS software under the influence of these different climates. An electric vapour compression pump, with 2.5 coefficient of performance (COP) for cooling is used as a reference system to assess the primary energy consumption, assuming 80% of primary energy consumed by the reference conventional system is replaced by solar energy. The results of analysing the proposed system indicated that an 80% of the primary energy savings can be achieved by installing 50 m 2 of solar collectors and 1.8 m 3 of hot water's storage tank under the three selected climates.

Infield greenhouse gas emissions from sugarcane soils in Brazil: effects from synthetic and organic fertilizer application and crop trash accumulation

AbstractBioethanol from sugarcane is becoming an increasingly important alternative energy source worldwide as it is considered to be both economically and environmentally sustainable. Besides being produced from a tropical perennial grass with high photosynthetic efficiency, sugarcane ethanol is commonly associated with low N fertilizer use because sugarcane from Brazil, the world's largest sugarcane producer, has a low N demand. In recent years, several models have predicted that the use of sugarcane ethanol in replacement to fossil fuel could lead to high greenhouse gas (GHG) emission savings. However, empirical data that can be used to validate model predictions and estimates from indirect methodologies are scarce, especially with regard to emissions associated with different fertilization methods and agricultural management practices commonly used in sugarcane agriculture in Brazil. In this study, we provide in situ data on emissions of three GHG (CO2, N2O, and CH4) from sugarcane soils in Brazil and assess how they vary with fertilization methods and management practices. We measured emissions during the two main phases of the sugarcane crop cycle (plant and ratoon cane), which include different fertilization methods and field conditions. Our results show that N2O and CO2 emissions in plant cane varied significantly depending on the fertilization method and that waste products from ethanol production used as organic fertilizers with mineral fertilizer, as it is the common practice in Brazil, increase emission rates significantly. Cumulatively, the highest emissions were observed for ratoon cane treated with vinasse (liquid waste from ethanol production) especially as the amount of crop trash on the soil surface increased. Emissions of CO2 and N2O were 6.9 kg ha−1 yr−1 and 7.5 kg ha−1 yr−1, respectively, totaling about 3000 kg in CO2 equivalent ha−1 yr−1.

LCA of waste prevention activities: A case study for drinking water in Italy

The strategic relevance of waste prevention has considerably increased worldwide during recent years, such that the current European legislation requires the preparation of national waste prevention programmes in which reduction objectives and measures are identified. In such a context, it is possible to recognise how, in order to correctly evaluate the environmental consequences of a prevention activity, a life cycle perspective should be employed. This allows us to go beyond the simple reduction of the generated waste which, alone, does not automatically imply achieving better overall environmental performance, especially when this reduction is not pursued through the simple reduction of consumption. In this study, the energetic and environmental performance of two waste prevention activities considered particularly meaningful for the Italian context were evaluated using life cycle assessment (LCA) methodology. The two activities were the utilisation of public network water (two scenarios) and of refillable bottled water (two scenarios) for drinking purposes, instead of one-way bottled water (three scenarios). The energy demand and specific potential impacts of the four waste prevention scenarios and of the three baseline scenarios were compared with the aim of evaluating whether, and under what conditions, the analysed prevention activities are actually associated with overall energetic and environmental benefits. In typical conditions, the use of public network water directly from the tap results in the best scenario, while if water is withdrawn from public fountains, its further transportation by private car can involve significant impacts. The use of refillable PET bottled water seems the preferable scenario for packaged water consumption, if refillable bottles are transported to local distributors along the same (or a lower) distance as one-way bottles to retailers. The use of refillable glass bottled water is preferable to one-way bottled water only if a distance beneath 150 km separates bottling plants from local distributors and retailers (except for eutrophication indicator which is always slightly worse). To reduce waste generation and to achieve meaningful potential savings of natural resources, energy and greenhouse gas emissions, a reduction in one-way bottled water consumption in Italy is recommended in favour of the use of public network water and of the establishment of short distance-PET bottles based refilling systems. The development of closed loop recycling of one-way PET bottles, and especially the reduction of the distance along which one-way bottled water is transported, are also important.

Life cycle energy consumption and GHG emission from pavement rehabilitation with different rolling resistance

Abstract This paper describes a pavement life cycle assessment (LCA) model developed to evaluate energy use and greenhouse gas (GHG) emissions from pavement rehabilitation strategies. The LCA model analyzes the energy and GHG emissions associated with material production, construction and pavement use, which includes the effects of pavement rolling resistance on vehicle operation. The model was used to evaluate a set of case studies of pavement rehabilitation for both asphalt and concrete surfaces with different rolling resistances and traffic levels. The primary goal of the case studies is to evaluate the effect of rolling resistance on the life cycle performance of pavements, not to compare asphalt and concrete pavements. Energy and GHG emission savings from pavement rehabilitation are compared with an alternative where no rehabilitation occurs, only routine maintenance of damaged pavement. The results of the case studies show that for highway sections with high traffic volumes the energy and GHG savings accrued during the use phase due to reduced rolling resistance can be significantly larger than the energy use and GHG emissions from material production and construction, with the extent of the benefit dependent on constructed smoothness. These savings can be larger than those from other strategies to reduce highway transportation energy use and emissions, such as projected improvements in vehicle fuel economy. For low traffic volume highways, the smoothness obtained by the contractor and materials used have a more significant effect on the performance of the rehabilitation, and may result in a net increase in energy use and GHG emissions if low traffic volumes and poor construction quality occur together.

Estimating Potential Community-wide Energy and Greenhouse Gas Emissions Savings from Residential Energy Retrofits

The residential sector accounts for over 20% of U.S. primary energy consumption and offers numerous opportunities for conservation and efficiency. Chief among these is retrofitting existing homes, which can reduce annual household energy consumption while also improving indoor air quality and thermal comfort and supporting local economic development. Many U.S. localities identify residential retrofits as a major priority in their Climate Action Plans, but lack information on the extent of energy consumption and greenhouse gas (GHG) reduction that they can achieve. We present a methodology used in Blacksburg, Virginia, to estimate potential energy and GHG savings from a residential retrofit program, which we find could reduce projected year 2050 residential energy use by as much as 36%. We conclude with a discussion of the obstacles that communities face in implementing retrofit programs and steps being taken in Blacksburg to overcome those obstacles.

Omnigen: Providing electricity, food preparation, cold storage and pure water using a variety of local fuels

We describe a polygeneration system that can run on neat plant oils, such as Jatropha and Pongamia, or standard diesel fuel. A prototype has been constructed using a compression ignition engine of 9.9 kW shaft output. It consumes 3 L/h of fuel and will produce 40 kg/h of ice by means of an adsorption refrigerator powered from the engine jacket heat. Steaming of rice, deep and shallow frying, and other types of food preparation heated by the exhaust gas have been demonstrated. In addition, the feasibility of producing distilled water by means of multiple-effect distillation powered by the engine waste heat is shown. Overall plant efficiency and potential savings in greenhouse gas emissions are discussed.

Integration of CO2 refrigeration and trigeneration systems for energy and GHG emission savings in supermarkets

The environmental impact of supermarkets is significant not only because of the indirect effect from CO2 emissions at the power stations but also due to the direct effect arising from refrigerant leakage to the atmosphere. One approach through which the overall energy efficiency can be increased and the environmental impacts reduced, is through the integration of CO2 refrigeration and trigeneration systems where the refrigeration generated by the trigeneration system is used to condense the CO2 refrigerant in a cascade arrangement. This paper reports on experimental and theoretical investigations of such a system and its potential application in a supermarket. The results show that the system can offer energy savings of 30%, greenhouse gas emission savings of 43% and a payback period of just over 3 years compared to conventional systems.

Greenhouse Gas Emissions from Operating Reserves Used to Backup Large-Scale Wind Power

Wind farms provide electricity with no direct emissions. However, their output cannot be forecasted perfectly, even a short time ahead. Consequently, power systems with large amounts of wind power may need to keep extra fossil-fired generators turned on and ready to provide power if wind farm output drops unexpectedly. In this work, I introduce a new model for estimating the uncertainty in short-term wind power forecasts, and how this uncertainty varies as wind power is aggregated over larger regions. I then use this model to estimate the reserve requirements in order to compensate for wind forecast errors to a 99.999% level of reliability, and an upper limit on the amount of carbon dioxide that would be emitted if natural gas power plants are used for this purpose. I find that for regions larger than 500 km across, operating reserves will undo 6% or less of the greenhouse gas emission savings that would otherwise be expected from wind power.

Incorporation of Variable-Speed Pumping in Multiobjective Genetic Algorithm Optimization of the Design of Water Transmission Systems

Global warming caused by human activities presents serious global risks. Individuals, governments, and industries need to be more energy efficient and contribute to the mitigation of global warming by reducing their greenhouse gas (GHG) emissions. In previous research, GHG emission reduction has been identified as one important criterion in improving the sustainability of urban infrastructure and urban water systems. Within the water industry, opportunities exist for reducing GHG emissions by improving pumping efficiency via the use of variable-speed pumps (VSPs). Previously, VSPs have been used in the optimization of the operation of existing water distribution systems (WDSs). However, in WDS design optimization problems, fixed-speed pumps (FSPs) are commonly used. In this study, a pump power estimation method, developed using a false position method based optimization approach, is proposed to incorporate VSPs in the conceptual design or planning of water transmission systems (WTSs), using optimization. This pump power estimation method is implemented within the solution evaluation process via a multiobjective genetic algorithm approach. A case study is used to demonstrate the application of the pump power estimation method in estimating pump power and associated energy consumption of VSPs and FSPs in WTS optimization. In addition, comparisons are made between variable-speed pumping and fixed-speed pumping in multiobjective WTS optimization accounting for total cost and GHG emissions. The results show that the use of variable-speed pumping leads to significant savings in both total cost and GHG emissions from WTSs for the case study considered.