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In the context of the global response to climate change, methanol is receiving widespread attention as a potentially clean, renewable fuel. In this paper, the effects of injection timing and split injection strategy on the combustion process and emissions were investigated in methanol engines. The effect of mixture control on the ignition delay period was studied in detail. The results showed that when the injection timing was advanced to 95 °CA bTDC, the ignition delay period and combustion duration period were reduced by 28.96 % and 6.14 %, respectively. When the injection timing was delayed, the NO X emissions of the methanol engine were significantly reduced by 6.13 %–20.39 %. The use of split injection strategy enables the formation of a reasonably stratified fuel-air mixture in the cylinder. Under the optimized split injection strategy, the combustion duration was shortened by 0.93 %–14.58 %. The ignition delay period of the IT105S2 was shortened by 28.62 % compared with that of the original engine. In addition, the reasonable split injection strategy can effectively reduce the emission of formaldehyde and unburned methanol. This study provides an optimization direction for the application of methanol in the internal combustion engine for high efficiency and clean combustion. [Display omitted] • Split injection strategies and injection timing are studied on methanol engines. • NO X emission decreased by 6.13 %∼20.39 % as the injection timing is delayed. • Split injection facilitates the formation of a reasonably stratified mixture. • Combustion duration was reduced by 0.93 %∼14.58 % with split injection. • The formaldehyde and unburned methanol were reduced with spilt injection. [ABSTRACT FROM AUTHOR]

In this paper we estimate the availability of shrub biomass along two different geographical transects in the Iberian Peninsula, i) North transect: NE-NW and ii) an Atlantic-Mediterranean transect: NW-S. To determine the available shrub area, the legal, technical, economic and environmental restrictions pertinent to the study areas were identified and their relative thresholds were established. Additionally, the amount of available shrub biomass (tonnes dry matter per hectare) along both geographical transects was calculated using equations specifically created for Spanish shrub formations. The NE-NW transect gave shrub biomass accumulations ranging from 11 to 16 t ha −1 , while the NW-S transect displayed much lower values, from 3 to 16 t ha −1 . Furthermore, the stored energy potential (gigajoules per hectare) for each shrub formation was calculated at each location. This paper provides realistic information, by shrub formation, on shrub biomass availability in the Mediterranean basin, highlighting the suitability of scrublands as potential sources of biomass, as well as the strengths and weaknesses of harvesting such biomass using machinery specifically designed for shrubs. [ABSTRACT FROM AUTHOR]

The focus of this study is to show that by understanding the food-energy-water nexus, potential unforeseen negative outcomes can be avoided in the pursuit of sustainable development. To do this, this paper uses a novel approach to compare a combined farm and short rotation coppice willow system, in which the willow was planted as a riparian buffer, with a food-only and an energy only system. The impact of each system was investigated through the lens of the food-energy-water nexus using life cycle assessment techniques. Data from previous research was adapted in order to quantify the impacts for a typical Irish dairy farm, which is indicative of intensive agriculture across Europe. On a typical Irish dairy farm, the implementation of a short rotation coppice willow riparian buffer strip could reduce total nitrogen and phosphorus leachate by 14% and 9% respectively. Total CO 2 eq emissions could be reduced by 16.5% if energy from the willow displaces fossil fuels, while the impact on milk production and profit is minimal. Thus, the use of short rotation coppice willow as a riparian buffer strip has the potential to reduce strain on the entire food-energy-water nexus. By considering the food-energy-water nexus, the negative impacts of the food-only and energy-only systems were also highlighted. The paper also shows how a better understanding of the food-energy-water nexus supports the United Nations Sustainable Development Goals and could help ameliorate the impact of climate change on the food-energy-water ecosystem. Image 1 • Understanding the FEW nexus supports the UN Sustainable Development Goals. • Negative outcomes can be avoided by assessing systems using the lens of the FEW nexus. • SRC willow riparian buffer strips can complement agricultural intensification. • Nitrogen (−14%) and phosphorus (−9%) exports to water can be permanently reduced. • Agricultural GHG emissions can be reduced by 16.5%. [ABSTRACT FROM AUTHOR]

Waste wood represents as much a waste to dispose of as a secondary resource to exploit. Various studies have assessed the energy potential and/or climate impact of energy recovery from waste wood. This paper aims to assess the long-term potential of waste wood for energy production and greenhouse gas (GHG) emissions reduction in Switzerland. Material flow analysis (MFA) is applied for modelling the metabolism of wood and waste wood in the Swiss anthroposphere over one century. The energy and climate impacts are estimated for 32 scenarios which assume different forest harvesting variants and waste wood treatment options. The scenario analysis shows that waste wood treatment options are more beneficial in the long term in terms of energy production (by energy recovery from waste wood) and of GHG emission reduction than the increase in the quantities of waste wood generated in the future caused by the advocated strategies of increased forest harvesting. By using the Maximin criterion, the long-term optimal additional potential for energy recovery from waste wood is estimated at 2110 GWh/year of useful energy, which offers a reduction of 364 tonnes of CO 2 equivalents per year. As prerequisites, the nominal installed capacity of the waste wood boilers needs to be raised and their efficiency and as well as those of incineration plants need to be increased. In addition, the sustainable potential of Swiss forests must be fully exploited. This study identifies various recommendations for the optimal exploitation of energy recovery from waste wood. [ABSTRACT FROM AUTHOR]

Several European policies have been designed over the last decades to address the challenge of climate change and several measures have been put in place to accelerate the development and deployment of cost-effective low carbon technologies. The domestic nature of the resource and its great potential availability in Europe make biomass conversion technologies relevant mitigation options to be considered. In this context, the project “Logistics for Energy Crops Biomass (LogistEC)” aims to develop new or improve technologies of biomass logistics chain. In this project, the sustainability of different types of biomass is analysed in terms of environmental, economic and social impacts, based on the supply chain of two existing plants. The objective of this paper is to present the main results obtained in the socio-economic analysis of the French case and its climate change consequences. The Input-Output Analysis (IOA) has been seen as the most appropriate method to estimate these impacts using a Multiregional Input-Output Table from the World Input-Output Database project. Socio-economic effects have been estimated in terms of additional economic activity, added value and job creation. By extending the IOA with environmental accounts, greenhouse gas (GHG) emissions have also been estimated. Additionally, the most stimulated sectors have been identified. Results highlight the importance of biomass at a national level. [ABSTRACT FROM AUTHOR]

Polymers are one of the most used materials and the majority of their production is based on fossil fuels. Due to the decrease of oil resources and concerns about climate change, alternatives are needed, the transformation of biobased ethanol into biobased polymer being one of them. This paper undertakes an environmental evaluation of the production of biobased polymer produced from two different feedstock cultivated in Belgium: sugar beet and wheat. Both crops cultivation are studied as well as their transformation into biobased ethanol, first, and then to biobased ethylene, focusing on high-density polyethylene (HDPE) as final product. These scenarios are analyzed and compared with the production of conventional polymer using the life-cycle assessment (LCA) methodology with reference to relevant environmental impact categories. This study shows a reduction of impact of around 60% for both climate change and fossil fuel depletion categories when using biobased HDPE instead of its fossil counterpart. For all other impact categories, fossil HDPE achieves better results than the biobased product. [ABSTRACT FROM AUTHOR]

The greenhouse gas emissions associated with bioenergy are often temporally dispersed and can be a mixture of long-term forcers (such as carbon dioxide) and short-term forcers (such as methane). These factors affect the timing and magnitude of climate-change impacts associated with bioenergy in ways that cannot be clearly communicated with a single metric. This is critical as key comparisons that determine incentives and policy for bioenergy are based upon climate-change impacts expressed as carbon dioxide equivalent calculated with GWP100. This paper explores these issues further and presents a spreadsheet tool to facilitate quick assessment of these temporal effects. The potential effect of (i) a mix of GHGs and (ii) emissions that change with time are illustrated through two case studies. In case study 1, variations in the mix of greenhouse gases mean that apparently similar impacts after 100-years, mask radically different impacts before then. In case study 2, variations in the timing of emissions cause their climate-change impacts (integrated radiative-forcing and temperature change) to differ from the impacts that an emissions-balance would suggest. The effect of taking alternative approaches to considering "CO 2 -equivalence" are also assessed. In both cases, a single metric for climate-change effects was found to be wanting. A simple tool has been produced to help practitioners evaluate whether this is the case for any given system. If complex dynamics are apparent, it is recommended that additional metrics, more detailed inventory, or full time-series impact results are used in order to accurately communicate these climate-change effects. • Climate-change effects of two case studies compared to results from carbon-balance. • Single metrics do not always fully convey climate-change impacts. • Spreadsheet tool made available to facilitate assessment of temporal variation in impacts. • Inclusion of additional results recommended to provide complete picture. [ABSTRACT FROM AUTHOR]

Facility siting has traditionally been performed using economic metrics alone to determine suitable locations for a new facility. In this era of climate change concerns and political discord, a more holistic approach to biorefinery siting may yield alternative locations that meet stakeholder goals for community acceptance and reduced environmental impacts. A multi-criteria decision support tool (DST) that incorporates economic, environmental, and social metrics concurrently is introduced to assess the repurpose potential of existing facilities as a wood-based biorefinery. Economic siting criteria are represented by biorefinery operational cost components that vary geospatially. The environmental criterion is the Global Warming Potential of the supply chain, as measured through greenhouse gases emitted from the feedstock procurement, preprocessing, and transport equipment. Social criteria are represented by 1) the number of regional jobs created through the installation of a biofuel supply chain, and 2) county-level social assets that may influence biorefinery project success. Weights and scale values are derived for each set of metrics. An overall facility score is produced by summing the three metric scores. Additionally, overall user-defined metric weights are used to adjust the importance of the three metrics, thus altering the overall facility scores. The DST is applied to a case study in Western Oregon and Western Washington to refine a list of candidate pulp mills down to a select few for further investigation. It was found that the mills scored differently when overall metric weights were adjusted. Therefore, different stakeholder preferences may yield a different priority list of facilities. • Decision support tool combines economic, environmental, and social datasets. • Candidate facilities are scored on how their assets match the proposed biorefinery. • User defined weights allow for adjusting the importance of each metric. • The tool provides for refining a list of alternative sites down to a select few. [ABSTRACT FROM AUTHOR]