Biomass-to-liquids seen as key to biofuels future
Different ways to make biofuels can be grouped in 'generations', according to the type of technology they rely on and the biomass feedstocks they convert into fuel.
Testifying to this, is the U.S. government's US$385 million worth of grants announced last week (earlier post) and distributed amongst six companies. Mainstream media did not take not of the surprising fact that half of the six projects chosen will use this thermochemical process, which was first discovered almost a century ago to turn coal into a gas:
biomass :: bioenergy :: biofuels :: energy :: sustainability :: gasification :: syngas :: Fischer-Tropsch :: synthetic biofuels :: biomass-to-liquids ::
Long hailed as a more environmentally friendly way to turn coal into electricity, the gasification process might provide a faster and eventually cheaper way to produce ethanol from a variety of renewable sources collectively known as biomass, some scientists say.
For corn-based ethanol plants, the process of producing ethanol is as simple as brewing beer: sugars are extracted from the corn kernels and then enzymes are added to ferment it into alcohol. But biomass feedstocks don't easily give up their starches, so more expensive steps are needed to ferment cellulose in high-pressure chambers that have limited amounts of oxygen, according to Lanny Schmidt, a University of Minnesota chemical engineer.
Energy Secretary Samuel Bodman pegged the current cost of gasification as being about twice as much as the average $1.10 per gallon cost at corn-based ethanol plants.
A gasifier turns plant material into a synthesis gas consisting mostly of carbon monoxide and hydrogen. The "syngas" then could be turned into a variety of fuels including ethanol, hydrogen and environmentally friendly versions of diesel or gasoline, Schmidt said.
"These gasifiers are some high-tech stuff with high pressures and some more complexities," he said. "But they're probably more versatile at the end of the day to modify them as the demand and supplies change."
Gasification is a fairly simple process, based on chemistry developed in the 1920s, said Robert Brown, an Iowa State University chemical engineering professor and director of the school's Office of Biorenewables Programs.
The syngas produced during gasification mixes more readily with chemical catalysts, so it could be more easily turned into other fuels, chemicals and materials. Just add steam and you could produce hydrogen to power a fuel-cell vehicle, Brown said.
Of the six companies awarded U.S. Department of Energy grants, three will use versions of fermentation technology. But two others will use gasification and one will use a hybrid of both technologies:
The Energy Department helped demonstrate the viability of gasification in the mid-1990s when it awarded Georgia-based FERCO $9.2 million to help build a power plant running on wood chips. By 2001, the $18 million plant in Burlington, Vt., was generating more than 200 megawatt-hours of electricity a day.
To compete in the marketplace, companies will have to make sure their feedstock supplies are consistent, do more research into catalysts that turn syngas into fuels, and develop better materials to contain the thermochemical reactions, according to the Energy Department.
The syngas would have to be cleaned and conditioned to remove contaminants, which is an expensive task. Energy officials say companies will have to bring down those costs if they're to compete in the market.
Mark Paster, a U.S. Department of Energy technology development manager who's studying ways to turn biomass into hydrogen, said both fermentation and gasification "are very viable and both routes continue to be researched and developed."
Paster said biomass helps reduce greenhouse gasses, so any method that can reach commercial viability will be better than one based on fossil fuel.
"There may not be a single winner, just like there's no winner in how we produce electricity," he said. "We do it in a variety of ways."
Article continues
- 'first generation' biofuels, such as ethanol made from corn or sugarcane and biodiesel made from rapeseed, make use of the well established processes of starch and sugar fermentation (in the case of ethanol) and transesterification (in the case of biodiesel). For both types of fuel, easily extractible parts of plants are used, such as starch-rich corn kernels, grains or the sugar in canes; for biodiesel, oilseeds are used. The residues of the plants are not utilized.
- 'second generation' biofuels can use a far wider range of feedstocks, including biomass waste streams that are rich in lignin and cellulose, such as wheat straw, grass, or wood. In order to breakdown this biomass, two different processes are currently used: (1) the first one, a biochemical conversion technique, consists of using specialty enzymes that succeed in breaking down the ligno-cellulose and release the sugars, which can then be fermented into alcohol. This technology is best known as 'cellulosic ethanol' and will become efficient and cost-effective over the coming years, many hope. (2) The second technique, a thermochemical process (often called 'biomass-to-liquids'), relies on gasification, and consists of using high temperatures to turn biomass into a synthetic gas ('syngas'), consisting mainly of carbon monoxide and hydrogen. This gas can further be processed into different types of liquid fuel via Fischer-Tropsch synthesis. Fuels from this route are then called 'synthetic biofuels'. Alternatively, the syngas can be converted into hydrogen.
- 'third generation' biofuels rely on biotechnological interventions in the feedstocks themselves. Plants are engineered in such a way that the structural building blocks of their cells (lignin, cellulose, hemicellulose), can be managed according to a specific task they are required to perform. For example, plant scientists are working on developing trees that grow normally, but that can be triggered to change the strength of the cell walls so that breaking them down to release sugars is more easy. In third generation biofuels, a synergy between this kind of interventions and processing steps is then created: plants with special properties are broken down by functionally engineered enzymes.
Testifying to this, is the U.S. government's US$385 million worth of grants announced last week (earlier post) and distributed amongst six companies. Mainstream media did not take not of the surprising fact that half of the six projects chosen will use this thermochemical process, which was first discovered almost a century ago to turn coal into a gas:
biomass :: bioenergy :: biofuels :: energy :: sustainability :: gasification :: syngas :: Fischer-Tropsch :: synthetic biofuels :: biomass-to-liquids ::
Long hailed as a more environmentally friendly way to turn coal into electricity, the gasification process might provide a faster and eventually cheaper way to produce ethanol from a variety of renewable sources collectively known as biomass, some scientists say.
For corn-based ethanol plants, the process of producing ethanol is as simple as brewing beer: sugars are extracted from the corn kernels and then enzymes are added to ferment it into alcohol. But biomass feedstocks don't easily give up their starches, so more expensive steps are needed to ferment cellulose in high-pressure chambers that have limited amounts of oxygen, according to Lanny Schmidt, a University of Minnesota chemical engineer.
Energy Secretary Samuel Bodman pegged the current cost of gasification as being about twice as much as the average $1.10 per gallon cost at corn-based ethanol plants.
A gasifier turns plant material into a synthesis gas consisting mostly of carbon monoxide and hydrogen. The "syngas" then could be turned into a variety of fuels including ethanol, hydrogen and environmentally friendly versions of diesel or gasoline, Schmidt said.
"These gasifiers are some high-tech stuff with high pressures and some more complexities," he said. "But they're probably more versatile at the end of the day to modify them as the demand and supplies change."
Gasification is a fairly simple process, based on chemistry developed in the 1920s, said Robert Brown, an Iowa State University chemical engineering professor and director of the school's Office of Biorenewables Programs.
The syngas produced during gasification mixes more readily with chemical catalysts, so it could be more easily turned into other fuels, chemicals and materials. Just add steam and you could produce hydrogen to power a fuel-cell vehicle, Brown said.
Of the six companies awarded U.S. Department of Energy grants, three will use versions of fermentation technology. But two others will use gasification and one will use a hybrid of both technologies:
- Alico Inc., a LaBelle, Fla.-based agribusiness company, would get up to $33 million to turn yard waste, wood waste and citrus peel into syngas, which would then be converted into ethanol, electricity and hydrogen.
- Range Fuels Inc., of Broomfield, Colo., would get up to $76 million for a plant near Soperton, Ga., to convert timber scraps into syngas to make ethanol and methanol.
- Abengoa Bioenergy, a St. Louis-based division of Spain's Abengoa SA, would receive up to $76 million for an 11.4 million gallons-per-year plant in Colwich, Kan., that would use both biochemical and thermochemical processes to convert corn stalks, wheat straw and switchgrass.
The Energy Department helped demonstrate the viability of gasification in the mid-1990s when it awarded Georgia-based FERCO $9.2 million to help build a power plant running on wood chips. By 2001, the $18 million plant in Burlington, Vt., was generating more than 200 megawatt-hours of electricity a day.
To compete in the marketplace, companies will have to make sure their feedstock supplies are consistent, do more research into catalysts that turn syngas into fuels, and develop better materials to contain the thermochemical reactions, according to the Energy Department.
The syngas would have to be cleaned and conditioned to remove contaminants, which is an expensive task. Energy officials say companies will have to bring down those costs if they're to compete in the market.
Mark Paster, a U.S. Department of Energy technology development manager who's studying ways to turn biomass into hydrogen, said both fermentation and gasification "are very viable and both routes continue to be researched and developed."
Paster said biomass helps reduce greenhouse gasses, so any method that can reach commercial viability will be better than one based on fossil fuel.
"There may not be a single winner, just like there's no winner in how we produce electricity," he said. "We do it in a variety of ways."
Article continues
Wednesday, March 07, 2007
A closer look at sustainability criteria for biofuels
To many, these developments are going too quickly and they rightly caution against the potential dangers of a mass-adoption of biofuels. Environmental and social sustainability criteria should be put in place first, before a global trade in biofuels is allowed to emerge. But the creation and the controlled implementation of such a set of criteria is a slow process, whereas investors and their money move very fast... The nascent biofuels sector makes the conflict between narrow-minded, short-term economic interests and environmental sustainability very apparent.
Sadly, this somewhat simplistic dichotomy ('environment versus profit') has permeated the mainstream media. One type of media tends to focus on the mere commercial aspects of biofuels (announcing investment after investment), whereas another type dismisses all biofuels as an outright disaster without seeing the potential benefits for people, planet and profit. A more nuanced, scientifically sound perspective on the matter is very rare and urgently needed.
We try to offer such a view - hoping others will do so as well -, by presenting an in-depth look at some of the work being done by researchers into the rather complex matter of 'sustainability' as it relates to bioenergy and biofuels. We focus in on the analysis made by scientists from the Copernicus Institute for Sustainable Development and Innovation, at the Utrecht University's, Department of Science, Technology and Society.
Edward Smeets, André Faaij and Iris Lewandowski wrote "The impact of sustainability criteria on the costs and potentials of bioenergy production" for the International Energy Agency's Bioenergy Task 40, which analyses the potential for a global bioenergy trade.
Large potential
In the report, the authors begin by reminding us that many studies have been carried out that quantify the potential of the world to produce bioenergy. Results indicate that various world regions are in theory capable of producing significant amounts of bioenergy crops without endangering food supply or further deforestation. We earlier referred to some of this research (previous post).
The theoretical potential is huge: by 2050, the developing world can produce more than 800 Exajoules of exportable bioenergy, sustainably, whereas the global potential is around 1400Ej per year. Consider that today, the entire world uses around 420Ej worth of energy annually, from all sources (coal, oil, gas, nuclear, hydro and renewables). In short, there is a massive amount of energy that can be extracted from biomass.
The question is whether such large-scale production and trade of biomass can be undertaken in a way that is beneficial and balanced with respect to (1) the social well being of the people involved, (2) the ecosystem (planet) and (3) the economy (profit). The authors explore the impact of these different contrasting interests on the potential (quantity) and the costs (per unit) of bioenergy.
A spectrum of sets of sustainability criteria is developed - ranging from loose definitions to the most stringent - and applied to two case-studies, one for the Ukraine and one for Rio Grande do Sul, a region in South-Eastern Brazil. These regions were chosen because sufficient previous research is available, and because they have been identified as promising bioenergy producers and exporters. Poplar production in Ukraine and eucalyptus production in Brazil are used as the reference biomass feedstock. These feedstocks can be converted into liquid fuels (bio-oil or synthetic biofuels) or be used as solid biofuels for combustion (generating heat and electricity):
biomass :: bioenergy :: biofuels :: energy :: sustainability :: social sustainability :: environmental sustainability :: plantations :: energy crops :: bioenergy trade :: Ukraine :: Brazil ::
For both regions cost calculations are included for a representative intensive commercial short rotation forestry management system. The year 2015 was chosen as a target, because this allows a 10-year period required to implement changes in land-use, establish plantations and develop a framework to implement criteria.
Overall, the results of the study indicate that:
The researchers came to the above conclusions in the following way.
127 sustainability criteria
A list of 127 criteria relevant for sustainable biomass production and trade is composed based on an extensive analysis of existing certification systems on e.g. forestry and agriculture.
To be able to analyse the impact of these criteria on the cost and potential of bioenergy, the various criteria needed to be translated into a set of concrete (measurable) criteria and indicators that have an impact on the management system (costs) or the land availability (quantity). 12 criteria are included in this study, because not all criteria could reasonably be translated into practically measurable indicators and/or measures and many criteria are related and/or overlap.
Because there is no generally accepted definition of sustainability - except from very broad and often symbolic principles, such as those set out at the Earth Summit in 1992 - , two sets of criteria and indicators - a strict and a loose one - are defined, to represent the difference in individual perceptions of sustainability. The stricter set of criteria is more difficult to implement than the loose set, because the restrictions for production and other activities in the chain are more severe.
The twelve criteria in their loose and strict definition are presented in the table at the beginning of this article - click to enlarge.
Applying these two sets of criteria to the province of Rio Grande do Sul in Brazil and to the Ukraine as a whole, results in changes in both the costs of producing biofuels, and their potential availability. A reference scenario is included showing the cost-supply curve as it would emerge if no criteria were implemented. This reference scenario comes close to the 'loose' set of criteria. Results for the factors related to employment and land use are excluded from this first analysis and described below.
Total costs for bioenergy crop production in Brazil and Ukraine are calculated at €1.5/GJ to €3.5/GJ and €1.7/GJ to €6.1/GJ dependant on the land suitability class (and respective yields), including the impact of basic levels for the various sustainability criteria.
These criteria can be further grouped into three clusters.
Land use, socio-economic factors, environment
Land use patterns
Land use patterns include criteria related to the avoidance of deforestation, competition with food production and protection of natural habitats. The theoretical potential to generate surplus agricultural land in 2015 was estimated, following the methodology of Smeets (earlier post). This methodology includes, among other variables, population growth, income growth and the efficiency of food production.
Results indicate that (in theory) large areas surplus agricultural land could be generated without further deforestation or endangering the food supply. However, additional investments in agricultural intensification may be required to realise these technical potentials.
Socio-economic criteria
Socio-economic criteria include criteria related to e.g. child labour, (minimum) wages, employment, health care and education. Compliance with the various criteria results in additional (non) wage labour costs, which are a separate cost item in the calculation of the production costs of biomass. The loose set of criteria does not influence the costs or quantity of bioenergy crop production. The strict criteria related to child labour, health care and education has a very limited impact on the costs of bioenergy crop production, between up to 8% in Ukraine and up to 14% in Brazil (see the tables).
The impact of the strict criterion related to wages is larger, which results in an increase of the costs of bioenergy crop production of up to 8% in Ukraine to up to 42% in Brazil. In general, the impact of the strict set of criteria is limited, because labour costs account for maximum two-fifth of the total production costs.
Another key socio-economic issue is the generation of direct and indirect employment. The direct impact of bioenergy crop production on employment is calculated based on the labour requirement for the various management activities.
The indirect impact of bioenergy crop production consists of two aspects. First, the employment effect of the increase in demand for agricultural machinery and other inputs due to bioenergy crop production and the intensification of food production. Second, the investments in agriculture require increasing the efficiency of food production, which may lead to more mechanisation and a loss of employment. Indirect (employment) effects of increased agricultural productivity and additional biomass production are very likely to be positive though. Due to a lack of data and suitable methodologies the indirect employment effects could not be calculated in the framework of this study, but these indirect effects could be significant and require further study.
Environmental criteria
Environmental criteria include criteria related to e.g. soil erosion, fresh water use, pollution from the use of fertilizers and agricultural chemicals. Compliance with various environmental criteria requires an adaptation of the bioenergy crop management system, e.g. an increase in mechanical and manual weeding to avoid the use of agricultural chemicals. For the loose set of criteria no additional costs were required.
The impact of the strict criteria related to soil erosion is limited to 15% and 4% maximum in Brazil and Ukraine, respectively. The impact of the strict set of criteria related to pollution from chemicals is up to 16% in Brazil and up to 6% in Ukraine.
The strict set of criteria related to nutrient leaching and soil depletion results in a cost decrease of up to –2% in Brazil and up to –4% in Ukraine, which is the combined effect of increasing labour and machinery costs and decreasing fertilizer costs.
For the protection of biodiversity protection, 10 to 20% of the surplus agricultural land could be set aside, although we acknowledge that this may be insufficient for the protection of biodiversity and that additional or other requirements for the plantation management may be required.
Due to a lack of data and suitable methodologies, indirect effects from the intensification of agriculture were not included, but these are potentially significant. A logical consequence would be that similar criteria should be in please for conventional agriculture as for biomass production.
The total costs increase by 35% to 88% in Brazil and 10% to 26% in Ukraine, dependant on the land suitability class (yield). The highest impact on costs (in €/oven dry ton) can be found on the lowest productive areas, because a large share of the costs are fixed, while the yield level depends on the land suitability class. For many of the areas of concern included in this study, data and methods used to quantify the impact of sustainability criteria on costs or potential are crude and therefore uncertain.
The ecological criteria require a more site-specific analysis with specific attention for e.g. soil type, slope gradient and rainfall. The social oriented criteria require more reliable and detailed data e.g. at a household level data and better methodologies to analyse indirect effects. Further research in this area is needed to provide more accurate estimates of the impact that various sustainability criteria may have on the costs and potential of bioenergy crop production.
Conclusion
The researchers propose an approach that provides an original and quantitative framework that can be used as a basis for designing sustainable biomass production systems and for monitoring existing ones.
They suggest that, besides more detailed and refined approaches, the framework may also be developed into a more simplified quickscan method to identify and monitor biomass production regions. Such a quickscan would be a useful tool for stakeholders - NGO's, governments, businesses, civil society organisations - to use as a guideline for discussions about particular projects or to craft policies.
The main conclusion of the report is that a very large amount of biomass for energy can be produced in the foreseeable future, especially in the developing world, and that this potential can be realised in a sustainable manner. Moreover, the biofuels thus produced, would be quite competitive with fossil fuels at current prices.
Finally, site-specific research remains crucial. A general, quantitative sustainability framework may offer a starting point, but it can never replace the particularities of actual projects that involve unique communities and eco-systems, all with their own histories and their visions on what the future should bring.
More information:
The International Energy Agency's Bioenergy website, with an overview of its different Bioenergy Task Forces.
The IEA's Bioenergy Task 40, which analyses all aspects of sustainable international bioenergy trade.
Fair Biotrade project (2001-2004): M. Juninger, "Overview of recent developments in sustainable biomass certification" [*.pdf] - a paper giving a comprehensive outline of initiatives on biomass certification from different viewpoints of stakeholders. The scope of this paper includes mainly new initiatives in the development of biomass certification system, though existing certification systems are also briefly described, as experiences from these systems provide valuable inputs. The study includes an inventory of initiatives in the field of biomass certification from the perspective of various stakeholder groups, such as NGOs, companies, national government and international bodies. A second objective of the paper is to identify opportunities and limitations in the development of biomass certification, and to present possible approaches onhow to introduce biomass certification systems. The paper finishes with some recommendations and conclusions.
IEA Bioenergy Task 40: Edward Smeets, André Faaij and Iris Lewandowski, "The impact of sustainability criteria on the costs and potentials of bioenergy production. An exploration of the impact of the implementation of sustainability criteria on the costs and potential of bioenergy production, applied for case studies in Brazil and Ukraine" [*.pdf], Utrecht University, Department of Science, Technology and Society, Copernicus Institute for Sustainable Development and Innovation, May, 2005.
Biopact: Brazilian ethanol is sustainable and has a very positive energy balance - IEA report, Oct. 8, 2006.
Biopact: A look at Africa's biofuels potential, July 30, 2007.
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posted by Biopact team at 2:39 PM 0 comments links to this post