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Energy Crops: Achieving a Balance

por papinto, em 14.09.11

ScienceDaily (Sep. 13, 2011) — There has been much debate about the net benefit of growing energy crops to reduce greenhouse gas emissions. While it is accepted that energy crops can displace fossil fuel imports, the emissions from the cultivation of energy crops were until now uncertain.

Teagasc has carried out a number of research projects to quantify the greenhouse gas emissions associated with these crops.


One of the surprising findings of the research was that the conversion of grassland to biomass, which was previously thought to lead to large soil carbon losses, in fact maintained or improved the carbon balance through higher annual carbon sequestration rates and lower than expected carbon losses from ploughing.

"Perennial biomass, such as miscanthus and short rotation willow coppice, can form part of a sustainable solution to Ireland's future energy requirement. At the same time this will offset part of the greenhouse gas emissions within the agricultural sector," explains Dr Gary Lanigan at Teagasc's Environment, Soil and Land Use Department at Johnstown Castle.

However, challenges remain, explains Dr Lanigan: "The government's target is to supply 12% of national heat demand through co-firing with renewable resources by 2020. But, it takes years for energy crops to mature and to reach maximum sequestration potential. Therefore, urgent policies are required to encourage large-scale adoption of these systems."

"To incentivise the growing of energy crops, financial mechanisms would need to be put in place to allow agriculture to benefit from the greenhouse gas reductions associated with fossil fuel displacement. "Perennial biomass crops are ideally placed to be incentivised through an initial Domestic Offsetting scheme," concludes Dr Lanigan.


Teagasc. "Energy crops: Achieving a balance." ScienceDaily, 13 Sep. 2011. Web. 14 Sep. 2011.

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Reuters ( Fri, Jul 8 2011

By Charlie Dunmore

BRUSSELS (Reuters) - Europe's biodiesel industry could be wiped out by EU plans to tackle the unwanted side effects of biofuel production, after studies showed few climate benefits, four papers obtained by Reuters show.

Europe's world-leading $13 billion biodiesel industry, which has boomed in the wake of a decision by Brussels policymakers in 2003 to promote it, is now on the verge of being legislated out of existence after the studies revealed biodiesel's indirect impact cancels out most of its benefits.

"This study would pave the way for the demise of the European biodiesel sector," Philippe Tillous-Borde, chief of French oilseed giant Sofiproteol, which owns Europe's largest biodiesel producer, told Reuters.

The EU has been arguing for two years over the extent of indirect damage to the environment caused by it setting a target of increasing biofuel use to 10 percent of all road fuels by 2020, from less than three percent today.

Its own analysis shows the target may lead to an indirect one-off release of around 1,000 megatonnes of carbon dioxide -- more than twice the annual emissions of Germany.

The emerging picture that the EU has got its policy wrong has proved unpalatable, and the European Commission has refused a Reuters freedom of information request for the latest studies, arguing the public interest of disclosure is insufficient.

However, those documents have now been leaked.

"This would have significant implications for the existing EU biodiesel industry," said one of the leaked reports seen by Reuters, an impact assessment prepared by the Commission.

"The viability of existing investments could be affected in the long run, as the availability of conventional biodiesel feedstocks would be extremely reduced," it said.

The findings could have a major impact on the direction of investments by major oil companies such as BP and Royal Dutch Shell in low-carbon energy sources, and give a boost to firms involved in the development of next-generation biofuels from non-crop sources, such as Danish enzymes producer Novozymes and Spain's Abengoa.

In a second report, global biofuel experts warned that increased biofuel production driven by the EU's green energy targets will squeeze food supplies and increase global hunger.

"Any decline in consumption can have a severe impact for households that are already malnourished," said the report from a Commission workshop of international biofuel experts last November.


Biofuels were once seen as a silver bullet for curbing transport emissions, based on a theory that they only emit as much carbon as they absorbed during growth.

But that has been undermined by a new concept known as "indirect land-use change" (ILUC), which scientists are still struggling to accurately quantify.

In essence, it means that if you take a field of grain and switch the crop to biofuel, somebody, somewhere, will go hungry unless those missing tonnes of grain are grown elsewhere.

The crops to make up the shortfall could come from anywhere, and recent research shows the majority of new farmland, possibly as much as 80 percent, is created by cutting down forests.

Burning forests to clear that land can pump climate-warming emissions into the atmosphere, enough in theory to cancel out any of the climate benefits the biofuels were meant to bring.

"The experts unanimously agreed that, even when uncertainties are high, there is strong evidence that the ILUC effect is significant," said the report from the Commission's November workshop.

"The land use change effects make nearly half of the expected gains of shifting from fossil fuels to renewable biofuels disappear," said a third report by the International Food Policy Research Institute (IFPRI) for the EU.

Biodiesel from Asian palm oil, South American soy beans, and EU rapeseed all had a bigger overall climate impact than conventional diesel, said a fourth leaked document.

"These reports clearly show scientists are convinced that current EU biofuels policy will indirectly cause significant environmental damage," said Nusa Urbancic at green transport campaign group T&E.

"The EU must stop brushing the problem under the carpet."

But many in the biodiesel industry -- which accounts for around 80 percent of all biofuels -- argue the science is still too uncertain to legislate.

"It would be totally contradictory to act on the basis of results produced by a model that relies on false, poorly researched hypotheses," said Sofiproteol's Tillous-Borde.

Yet, scientists are starting to agree on a clear sustainability ranking, after four in-depth EU studies in 2010 and three more in 2011, with bioethanol seen as a better option due to higher energy content in the plants used to produce it.

"Ethanol feedstocks have a lower land use change effect than the biodiesel feedstocks. For ethanol, sugar beet has the lowest land use emission coefficients," said the IFPRI report.

The Commission's impact analysis predicts EU demand for biodiesel will collapse if their indirect impacts are taken into account in EU legislation. But at the same time it sees a sharp rise in demand for bioethanol from cereal crops and sugarcane, as well as advanced biodiesel produced from algae.

"Ethanol production capacity would need to be increased significantly to make up for the increased demand," it said.

The report said this shift in demand would be reflected in commodity markets, pushing down vegetable oil prices and to a lesser extent increasing the cost of sugar and grains.

(Additional reporting by Pete Harrison; editing by Keiron Henderson)

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Researchers at Empa, the Swiss Federal Laboratories for Materials Science and Technology, have together with their colleagues at the Swiss Roundtable on Sustainable Biofuels (RSB) and the HTW Berlin, Germany, developed an online tool to assess the sustainability of biofuel production. (Credit: Image courtesy of Empa)

ScienceDaily (June 16, 2011) — Various biofuels, first hailed as a way to a sustainable energy supply, have since fallen out of favor because of the overall negative impact they have on the environment, mainly due to the production of the biogenic fuels -- as they should be more aptly termed. Now researchers at Empa, the Swiss Federal Laboratories for Materials Science and Technology, have together with their colleagues at the Swiss Roundtable on Sustainable Biofuels (RSB) and the HTW Berlin, Germany, developed an online tool to assess the sustainability of biofuel production.

The new tool allows users to perform a self-assessment against the Principles and Criteria of the RSB and a self-risk assessment. The online tool also calculates greenhouse gas (GHG) emissions of biofuels for each lifecycle production step, from farming to final fuel distribution; this calculation can be done according to various methodologies. The development of the new tool, which is directly accessible (free of charge) at, took about two years and was supported by the Swiss State Secretariat for Economic Affairs (SECO).

The RSB Standard comprises 12 principles and criteria for sustainable biofuel production, including environmental and social principles such as food security and human and labor rights. For instance, "Greenhouse Gas Emissions" aims to mitigate climate change by requiring that biofuels significantly reduce lifecycle GHG emissions compared to fossil fuels. Under this principle, operators along each step in the biofuel production chain must calculate the GHG emissions of their operations.

Such calculations are complex and require a sound knowledge in biofuels' life cycle assessment (LCA). To facilitate the RSB certification process, Empa -- in collaboration with the HTW Berlin -- developed a web-based tool allowing for the online calculation of biofuels' GHG emissions. Various GHG calculation methods are implemented, including the Swiss standard (for mineral-oil tax-relief), the European Renewable Energy Directive (RED) standard, the Californian standard and the RSB standard. By allowing a risk assessment of biofuels production and an evaluation based on the RSB sustainability principles, the tool forms the entry point to the RSB sustainability certification. "As such, the tool is targeted at all stakeholders in the biofuels sector, ranging from energy crop farmers and biofuel producers to traders who want to demonstrate the sustainability of their products," explains Empa researcher Rainer Zah, who was heading the project.

Zah's team at Empa has a long-standing record in LCA for biofuels. In 2007, they conducted an LCA for biofuels on behalf of the Swiss government, which became the basis for the OECD strategy on biofuels and for the Swiss ordinance on tax redemption for sustainable biofuels. In the following years, the Empa researchers have analyzed the direct and indirect impacts of biofuels production in various regions in Latin America, Africa and India; they developed the first web-based LCA tool for biofuels ("Sustainable Quick Check for Biofuels," SQCB) that formed the basis for the new web-tool.

The tool is freely available on the internet and can be used by any interested party who wishes to perform lifecycle GHG calculations of biofuels or assess their biofuel operations; it allows the user to conduct a self-assessment against the RSB Principles & Criteria and a self-risk assessment against the RSB Standard for Risk Management. More information on the RSB, which is based within the Energy Center of the Lausanne Federal Polytechnic University (EPFL) can be found at

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ScienceDaily (Feb. 16, 2011) — A new study from the University of Illinois concludes that very high yield biomass would be needed in order to meet the ambitious goal of replacing 30 percent of petroleum consumption in the U.S. with biofuels by 2030.

A team of researchers led by Madhu Khanna, a professor of agricultural and consumer economics at Illinois, shows that between 600 and 900 million metric tons of biomass could be produced in 2030 at a price of $140 per metric ton (in 2007 dollars) while still meeting demand for food with current assumptions about yields, production costs and land availability.

The paper, published in the American Journal of Agricultural Economics, is the first to study the technical potential and costs associated with producing a billion tons of biomass from different agricultural feedstocks -- including corn stover, wheat straw, switchgrass and miscanthus -- at a national level.

According to the study, not only would this require producing about a billion tons of biomass every year in the U.S., it would also mean using a part of the available land currently enrolled in the Conservation Reserve Program for energy crop production, which could significantly increase biomass production and keep biomass costs low.

"Most studies only tell you how much biomass is potentially available but they don't tell you how much it's going to cost to produce and where it is likely to be produced," Khanna said.

"Our economic model looks at some of the major feedstocks that could produce biomass at various prices."

Khanna and her team concluded that high-yielding grasses such as miscanthus are needed to achieve the 30 percent replacement goal, "but even then it's going to be a fairly expensive proposition," she said.

When miscanthus is added to the mix, the goal of 1 billion tons of biomass can be achieved, but at a cost of more than $140 per ton.

"Most studies consider costs in the range of $40 to $50 per ton, which is fine when we're talking about biomass production to meet near-term targets for cellulosic biofuel production," Khanna said. "But if we really want to get to the 30 percent replacement of gasoline, at least with the current technology, then that's going to be much more costly."

According to Khanna, miscanthus has been excluded from previous studies because it's a crop that has yet to be grown commercially, and most of the research about it is recent and still considered experimental.

"But across the various scenarios and prices our model considered, miscanthus has the potential to provide 50 to 70 percent of the total biomass yield," she said. "In most parts of the U.S., miscanthus is cheaper to produce than switchgrass, making it a very promising high-yield crop."

The study also contends that the economic viability of cellulosic biofuels depends on significant policy support in the form of the biofuel mandate and incentives for agricultural producers for harvesting, storing and delivering biomass as well as switching land from conventional crops to perennial grasses.

"Unless biomass prices are really high, these perennial grasses are going to have a hard time competing with crops like corn, soybean and wheat for prime agricultural land," Khanna said. "The economics works in favor of using the marginal, less productive lands, where corn and soybean productivity is much lower. But even then there are limits as to how much we would like to use that land for biomass. The more efficiently we can use the land, the better."

With biofuels, there's also the common perception that there's an unavoidable trade-off between fuel and food, Khanna said.

"That concern is much more prevalent when we talk about first-generation biofuels like corn-based ethanol," she said. "But for second-generation fuels, you can use crop residues as well as dedicated energy crops that can be grown on marginal land. This reduces the need to divert cropland away from food crop production. I'm optimistic that we can get considerable amounts of biomass without disrupting food production."

But relying on crop residues alone won't be sufficient to scale production up to levels set by the Energy Independence and Security Act of 2007, which limits the production of corn ethanol to 56 billion liters after 2015, and mandates the production of at least 80 of the 136 billion liters of ethanol from non-corn starch-based cellulosic feedstocks by 2022.

"Crop residue yields tend to be relatively low per unit of land -- 2 to 3 tons per hectare," Khanna said. "That can get costly pretty quickly. There are also concerns about how much you want to take away because at some point it has a negative effect on soil productivity as well as water quality because it affects run-off. So there are limits to crop residues, which is why we have to take a closer look at energy crops."

Because even marginal land is costly and has some alternative use, both now and in the future, using it as efficiently as possible means focusing more on the highest-yielding energy crops, Khanna said.

"Clearly the way to go is with the high-yielding grasses, which means switchgrass and miscanthus, but what we found is that it's not going to be a single feedstock but really a mix of feedstocks," she said.

Different regions of the country have a comparative advantage in different types of feedstocks.

"Corn stover is more common in the upper Midwest and West, whereas miscanthus is more prevalent in the southern part of the country and switchgrass in the real northern and southern areas," Khanna said.

The research was supported by the U.S. Department of Energy, National Science Foundation, and the U. of I. Energy Biosciences Institute. Other co-authors are Hayri Önal, a professor of agricultural and consumer economics at Illinois, and research associates Xiaoguang Chen and Haixiao Huang, of the Energy Biosciences Institute.

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Wake Up and Smell the Willow

por papinto, em 04.01.11

ScienceDaily (Jan. 4, 2011)More plant matter could be burned in coal-fired power stations if this 'green' fuel was delivered pre-roasted like coffee beans, according to researchers from the University of Leeds, UK.

Many UK power stations are now burning plant matter, or biomass, as well as coal in a bid to cut their carbon footprint. Unlike fossil fuels, plants like willow, Miscanthus and poplar are a virtually carbon-neutral source of energy: the carbon dioxide emitted when they burn is absorbed during photosynthesis by the next batch of 'energy crops' planted in their place.

But the environmental benefits of biomass are countered by some real practical and economic challenges that are forcing power stations to restrict the amount of biomass used. Biomass is moist and bulky, making it relatively expensive to transport and difficult to store for long periods without going mouldy. The fibrous plant matter is also extremely difficult to process in the mills that are used to grind dry lumps of coal into dust before they are burned.

A roasting process known as torrefaction is the answer, according to Professor Jenny Jones and colleagues from the University of Leeds' School of Process, Environmental and Materials Engineering. This process, which sees the plant matter heated to around 300 degrees centigrade in an air-free container, transforms bulky biomass into a dry, energy-rich fuel that is cheaper and easier to move around and has a much longer shelf life.

A study of two common energy crops, willow and Miscanthus, has also shown that when the plant matter is 'torrefied' it can be ground into a powder just as easily as some good quality coals. This makes it far more practical and cost-effective to replace containers of coal with biomass in existing power stations.

Team members are now exploring whether the torrefaction process can be scaled up, with a view to producing a design 'blueprint' for industrial engineers.

"If we can show that torrefaction is feasible on an industrial scale then we would hope to end up with a demonstration plant here in the UK," Professor Jones said. "We already know that many more famers would be interested in growing energy crops on areas of poorer quality soil if the economic barriers were lowered and the power companies could use more biomass without losing out financially."

The project will address outstanding questions about the safety, practicality and environmental impact of large-scale torrefaction. For example, researchers will find out what the liquid and gaseous by-products of the roasting process are made up of. They will also assess how likely it is for dust generated by the roasting and milling processes to trigger explosions.

"It is well known that fine powders can cause violent explosions under certain conditions. We will be carrying out experiments to characterise the explosibility of biomass and torrified biomass powder so that appropriate safety features can be designed into industrial-scale powder handling and power generation plants," said University of Leeds researcher Dr Roth Phylaktou, an expert on fire and explosion safety engineering and a co-investigator on the project.

The researchers will work with a range of different materials that could potentially replace coal in future. These include energy crops such as willow and Miscanthus, which are grown specifically for making 'green' fuel, as well as waste plant matter from forestry plantations and farms, such as the branches of harvested pine trees and straw.

"These are all materials that grow well in the UK but not at the expense of food crops," said Professor Jones. "We do not want farmers to have to choose between planting a field of wheat or barley and a field of willow. Ultimately, this is all about providing a secure energy supply for the future and one that is sustainable on all levels. "

The project is being funded by the Engineering and Physical Sciences Research Council. The work is being carried out in collaboration with Alstom Power, Drax Power, EON and RWE nPower.

The team of engineering researchers at Leeds includes Professor Jenny Jones, Professor Alan Williams, Professor Gordon Andrews, Dr Roth Phylaktou and Dr Leilani Darvell.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Leeds, via EurekAlert!, a service of AAAS.

University of Leeds (2011, January 4). Wake up and smell the willow. ScienceDaily. Retrieved January 4, 2011, from­ /releases/2011/01/110104133911.htm

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ScienceDaily (July 12, 2010) — While scientists have conducted numerous studies on production of biomass from biofuel crops, such as switchgrass, no one has yet compiled this information to evaluate the response of biomass yield to soils, climate, and crop management across the United States.

A team of researchers from Oak Ridge National Laboratory and Dartmouth College published just such a study in the July-August 2010 Agronomy Journal, published by the American Society of Agronomy. The researchers used peer-reviewed publications to evaluate switchgrass yield as it relates to site location, plot size, stand age, harvest frequency, fertilizer application, climate, and land quality. Switchgrass is one type of crop under consideration for use as a feedstock for advanced biofuels.

The scientists compiled a total of 1,190 biomass yield observations for both lowland and upland types of switchgrass grown from 39 field sites across the United States. Observations were pulled from 18 publications that reported results from field trials in 17 states, from Beeville, TX in the south, to Munich, ND in the Midwest, and Rock Springs, PA in the northeast.

Among the many factors examined, statistical analysis revealed that much of the variation in yield could be accounted for by variation in growing season precipitation, annual temperature, nitrogen fertilization, and they type of switchgrass.

Lowland switchgrass outperformed upland varieties at most locations, except at northern latitudes. Annual yields averaged 12.9 metric tons per hectare for lowland and 8.7 metric tons for upland ecotypes. Some field sites in Alabama, Texas and Oklahoma reported biomass yields greater than 28 metric tons per hectare using the lowland cultivars Kanlow and Alamo.

The research team did not observe any bias for higher yields associated with experimental plot size, row spacing, or with preferential establishment of stands on high quality lands. A model developed from the data, based on long-term climate records, projected maximum yields in a corridor westward from the mid-Atlantic coast to Kansas and Oklahoma. Low precipitation west of the Great Plans limited yields in that region.

"Field trials are often planted to provide local estimates of crop production," said Stan Wullschleger, a crop physiologist who led the study. "However, viewed in a broader context, results from individual field trials can contribute to a larger perspective and provide regional to national scale estimates of yield and the variables that determine that yield."

Lee Lynd, co-author on the article and Steering Committee Chair of the Global Sustainable Bioenergy Project observed, "This is the largest data base analyzed to date for energy crop productivity as a function of geographically distributed variables. The finding that there is no bias with respect to either plot size or land productivity is important. A promising future direction is to apply the modeling approaches taken here to additional bioenergy crops at a global scale in combination with various land use scenarios."

Scientists at Oak Ridge National Laboratory and Dartmouth College continue to explore factors involved in the production of biomass from switchgrass and other dedicated energy crops. One of the lessons learned from the current analysis is that yield data from an even broader range of soil and climatic conditions will be useful in building better predictive models. Future studies should extend the geographic distribution of field trials and thus improve our understanding of biomass production for promising biofuels like switchgrass.

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Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by American Society of Agronomy.

Journal Reference:

  1. S. D. Wullschleger, E. B. Davis, M. E. Borsuk, C. A. Gunderson, L. R. Lynd. Biomass Production in Switchgrass across the United States: Database Description and Determinants of Yield. Agronomy Journal, 2010; 102 (4): 1158 DOI: 10.2134/agronj2010.0087

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Público 20100620 

Projecto de 7,5 milhões de euros está pronto para avançar e reúne mais três parceiros e uma empresa de capital de risco

Uma nova sociedade liderada pela Companhia das Lezírias (CL) pretende investir cerca de 7,5 milhões de euros na criação de um bioparque e na construção de uma central de biomassa, na zona do Catapereiro, junto à estrada que liga o Porto Alto a Alcochete.

O novo equipamento, único no Sul do Ribatejo, deverá receber desperdícios resultantes da actividade agrícola e florestal da região e, através deles, irá produzir calor, energia eléctrica e produtos específicos, como concentrados para utilização em lareiras.

Segundo Vítor Barros, presidente da Companhia das Lezírias, o projecto está a ser desenvolvido por uma nova empresa participada também pela Tecotimber (especializada em funções aéreas ligadas à exploração florestal), pela Frestec e pela Orivárzea (agrupamento ribatejano de produtores de arroz), que faz a recolha de palhas e casca de arroz.

Estes quatro parceiros terão parcelas de capital social semelhantes e a sociedade terá também a participação inicial de uma empresa de capital de risco que apoiará a alavancagem financeira do projecto.

"Está praticamente aprovado um apoio a fundo perdido da ordem de um milhão de euros", explicou Vítor Barros, frisando que esse financiamento proveniente da área da agricultura deverá ser destinado à instalação do bioparque, dedicado à concentração de todo o tipo de desperdícios agro-florestais que vão alimentar a futura central.

Ao mesmo tempo, os promotores do investimento têm procurado, junto do Ministério da Economia e da Inovação, apoios ou possibilidades de acesso a crédito com juros bonificados para a construção da central de biomassa. "Já temos autorização para injecção de energia na rede, através da subestação eléctrica do Porto Alto", acrescentou o presidente da CL.

Vítor Barros acrescentou que complexo será instalado na zona do Catapereiro, junto aos secadores e à adega que a Companhia das Lezírias já possui nesta área do extremo sul do Ribatejo, situada mesmo à beira da Estrada Nacional 118.

"Tudo o que é agro-indústria na área da Companhia vai ser transferido para aquela zona. Já estamos a preparar tudo para começar a fazer o investimento e já estamos, inclusivamente, a ver as caldeiras da futura central", prosseguiu Vítor Barros.

O líder da companhia agrícola de capitais públicos salientou que nos 20 mil hectares da Companhia das Lezírias são produzidas, anualmente, mais de 5000 toneladas de biomassa, mas que a central terá uma capacidade bastante superior e receberá materiais de toda a região envolvente.

A Companhia das Lezírias dedica-se a um conjunto diverso de actividades na área agrícola e florestal.

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