Thermal treatment of Himalayan balsam: Tar and biochar analysis

The practicality of Himalayan balsam as an alternative biomass material was considered throughout this investigation. However, due to the materials high-water content, thermal efficiency during pyrolysis was compromised as extra energy was required to remove free and bound water. A simple solution which involved drying at ambient temperature in air, significantly lowered the moisture content, (65% reduction) this resulted in an increase in the bulk density of the material and lowering the thermal energy input of the process. The thermal decomposition process at 300–400 °C generated petroleum like compound; a mixture of volatile aromatic, linear and branched alkanes, and therefore a possible source for replenishment of hydrocarbon-based fuel. The solid remaining carbon generated (~35% mass of dry material) termed biochar showed adsorption properties to rhodamine B dye. The level of activity was increased upon activation using phosphoric acid. The activated biochar could be a promising adsorbent used to remove aqueous organic compounds. The thermal treatment of Himalayan balsam has potential in generating useful products such as bio-fuels and biochar

The GHG emissions and economic performance of the Colombian palm oil sector; current status and long-term perspectives

Increasing oil palm plantations, both for obtaining crude palm oil (CPO) and for the production of biobased products, have generated growing concern about the impact of greenhouse gas (GHG) emissions on the environment. Colombia has the potential to produce sustainable biobased products from oil palm. Nevertheless, national GHG emissions have not yet been reported by this sector. Achieving the collection of the total primary data from the oil palm sector, in Colombia, entails a tremendous challenge. Notwithstanding, for this study, the data collection of 70% of the production of fresh fruit bunches (FFB) was achieved. Therefore, current situation of CPO production in Colombia is analyzed, including 1) GHG emissions calculation, 2) net energy ratio (NER), and 3) economic performance. Moreover, the analysis includes two future scenarios, where the CPO production chain is optimized to reduce GHG emissions. Future scenario A produces biodiesel (BD), biogas, cogeneration, and compost; while future scenario B produces BD, biogas, cogeneration, and pellets. The methodology, for all the scenarios, includes life-cycle assessment and economic analysis evaluation. The results show a significant potential for improving the current palm oil production, including a 55% reduction in GHG emissions. The impact of land-use change must be mitigated to reduce GHG emissions. Therefore, a sustainable oil palm expansion should be in areas with low carbon stock or areas suitable/available to the crop (e.g., cropland, pastureland). Avoiding the deforestation of natural forests is required. Besides, crop yield should be increased to minimize the land use, using biomass to produce biobased products, and capture biogas to reduce methane emissions. In the biodiesel production life-cycle, the NER analysis shows the fossil energy consumed is lower than the renewable energy produced. Regarding the economic performance, it shows that in an optimized production chain, the capital expenditure and operational expenditure will decrease by approximately 20%

On-farm anaerobic digestion: a disaggregated analysis of the policy challenges for greater uptake

In recent years, the multifunctionality of farming activities and diversification of on-farm income sources have increasingly included renewable energy generation. The uptake of on-farm anaerobic digestion (AD), however, continues to lag behind other renewable energy activities. Moreover, on-farm AD is not only a source of renewable energy, but also a means of farm waste management and thus a means of enhancing environmental quality. This paper provides an in-depth analysis of the policy barriers that might explain this limited uptake, and identify key directions for future AD policy design. We draw on a mixed-methods research design, with data collected by questionnaires, interviews and a round-table workshop of stakeholders. We analyse our data using a framework that disaggregates ‘policy’ into meta, meso and micro levels of Policy Means and Policy Ends. We conclude that future policy must recognise the synergies between on-farm AD as a source of renewable energy and as a means of waste management, reflected in instrument mix and instrument calibration. Calibration-stability is also found to be of critical importance. We also offer new insights and understanding around the application of our chosen policy framework, notably how it can analyse policies that are nested within large, complex policy systems

Applying a science‐based systems perspective to dispel misconceptions about climate effects of forest bioenergy

The scientific literature contains contrasting findings about the climate effects of forest bioenergy, partly due to the wide diversity of bioenergy systems and associated contexts, but also due to differences in assessment methods. The climate effects of bioenergy must be accurately assessed to inform policy-making, but the complexity of bioenergy systems and associated land, industry and energy systems raises challenges for assessment. We examine misconceptions about climate effects of forest bioenergy and discuss important considerations in assessing these effects and devising measures to incentivize sustainable bioenergy as a component of climate policy. The temporal and spatial system boundary and the reference (counterfactual) scenarios are key methodology choices that strongly influence results. Focussing on carbon balances of individual forest stands and comparing emissions at the point of combustion neglect system-level interactions that influence the climate effects of forest bioenergy. We highlight the need for a systems approach, in assessing options and developing policy for forest bioenergy that: (1) considers the whole life cycle of bioenergy systems, including effects of the associated forest management and harvesting on landscape carbon balances; (2) identifies how forest bioenergy can best be deployed to support energy system transformation required to achieve climate goals; and (3) incentivizes those forest bioenergy systems that augment the mitigation value of the forest sector as a whole. Emphasis on short-term emissions reduction targets can lead to decisions that make medium- to long-term climate goals more difficult to achieve. The most important climate change mitigation measure is the transformation of energy, industry and transport systems so that fossil carbon remains underground. Narrow perspectives obscure the significant role that bioenergy can play by displacing fossil fuels now, and supporting energy system transition. Greater transparency and consistency is needed in greenhouse gas reporting and accounting related to bioenergy

Impact of nitrogen allocation on growth and photosynthesis of Miscanthus (Miscanthusgiganteus)

Abstract Nitrogen (N) addition typically increases overall plant growth, but the nature of this response depends upon patterns of plant nitrogen allocation that vary throughout the growing season and depend upon canopy position. In this study seasonal variations in leaf traits were investigated across a canopy profile in Miscanthus (Miscanthus 9 giganteus) under two N treatments (0 and 224 kg ha À1 ) to determine whether the growth response of Miscanthus to N fertilization was related to the response of photosynthetic capacity and nitrogen allocation. Miscanthus yielded 24.1 Mg ha À1 in fertilized plots, a 40% increase compared to control plots. Photosynthetic properties, such as net photosynthesis (A), maximum rate of rubisco carboxylation (V cmax ), stomatal conductance (g s ) and PSII efficiency (F v '/F m '), all decreased significantly from the top of the canopy to the bottom, but were not affected by N fertilization. N fertilization increased specific leaf area (SLA) and leaf area index (LAI). Leaf N concentration in different canopy layers was increased by N fertilization and the distribution of N concentration within canopy followed irradiance gradients. These results show that the positive effect of N fertilization on the yield of Miscanthus was unrelated to changes in photosynthetic rates but was achieved mainly by increased canopy leaf area. Vertical measurements through the canopy demonstrated that Miscanthus adapted to the light environment by adjusting leaf morphological and biochemical properties independent of nitrogen treatments. GPP estimated using big leaf and multilayer models varied considerably, suggesting a multilayer model in which V cmax changes both through time and canopy layer could be adopted into agricultural models to more accurately predict biomass production in biomass crop ecosystems. While it is well known that N addition typically increases plant growth, less is known about how N addition affects patterns of N allocation through the canopy. Part of this is due to the complexity of plant allocation patterns. N allocation varies both vertically in the plant canopy in response to changes in light availabilit

Next Generation Biofuels and Advanced Engines for Tomorrow’s Transportation Needs

In November 2009, Sandia National Laboratories hosted the Next Generation Biofuels and Advanced Engines for Tomorrow’s Transportation Needs Workshop. The event focused on the combined opportunities in biofuels and engines in the transportation sector. The workshop brought together the DOE Combustion Research Facility and the DOE Joint BioEnergy Institute along with oil companies, biofuel developers, engine manufacturers, suppliers, and experts from the university, regulatory, finance, and national laboratory communities. The intersection of biofuels and engines, if properly scaled, can meet a triad of national goals: • Reduced climate impact • Economic development • Energy security through energy diversity The workshop identified opportunities for codevelopment of biofuels and engines, it addressed roadblocks to success, and it outlined joint biofuel and engine R&D needs. Over two days, participants underscored a series of key attributes that the community must address to make introducing next generation biofuels a reality in the transportation sector. These attributes can be summarized as the need for: Clean, Sustainable, Compatible, Liquid, Fuels • Clean. Next generation biofuels might be oxygenates, blended constituents, or drop-in replacements. Their combustion, however, must not increase Environmental Protection Agency (EPA) designated criteria pollutants, nor can these biofuels introduce other air and water contaminants. • Sustainable. Based on a thorough life cycle analysis, the CO2 footprint of biofuels must be lower than the petroleum-based fuels that are being displaced. • Compatible. The need for compatibility has multiple dimensions. First, the biofuel should be compatible with both current and future engine designs, including any aftertreatment and fuel storage components on board the vehicle. Second, the biofuel should be compatible with the current distribution infrastructure as well as future infrastructures that may evolve. Compatibility with the current fuel industry infrastructure will accelerate the introduction of alternatives. • Liquid. The driving force for biofuels is to displace petroleum feedstocks. The goal is to both reduce the CO2 footprint and allow for enhanced security through diversity and choice in fuel sources. Liquid petroleum products are attractive in internal combustion engines due to their energy density (volume and weight). Next generation biofuels must be of the same or higher energy density. • Fuels. To make a significant impact on the transportation energy sector, a path to scale-up of next generation biofuels must be included in the research, development, and deployment planning. Business models that address scaling to significant quantities are critical. General Observations The workshop recognized three important issues surrounding the development of biofuels: • The definition of fungible or drop-in fuels (DIF) needs to be clarified. The framework for fungible fuels development is not clear, nor have the fuel and engine communities fully vetted the options. • Fuel specifications can become the bridge between engines and biofuels. Both gasoline and diesel engine designers need to provide greater specificity to the fuels development communities, both for near-term and for future engine concepts. • An integrated biofuels and engines research program is key. Today two separate DOE program offices fund research on biofuels and advanced engine concepts. A consolidated research program would acce