World's first: Wärtsilä to power green Finnish town with biogas fuelled Solid Oxide Fuel Cell

Finnish energy solutions provider Wärtsilä will demonstrate a planar solid oxide fuel cell (SOFC) power unit fuelled by renewable biogas in the city of Vaasa, in West-Finland, as part of the 2008 Green Housing Fair. The unit will provide ultra-low emissions clean heat and power for 50 of the eco-homes, in an extremely efficient manner.

The unit to be demonstrated, dubbed WFC50 by the Wärtsilä engineers, will use biogas or biomethane from a nearby landfill site to provide heat and power to Vaasa's electricity and district heating grid. This will be the first time a solid oxide fuel cell will have been used in such an application, and as such it heralds an interesting time for fuel cell development.

At the first stage, the SOFC system will produce an electric output of approximately 20 kW and a thermal output of 14 to 17 kW, later to be scaled up to a combined capacity of 50kW. Current experimental SOFC units are typically designed with power in the range of of 1 – 5 kW to supply combined heat and power for individual homes. The size of the WFC50 would place it in the commercial, district and industrial customer range. Wärtsilä is now focusing on the 20 – 50 kW demonstration units. After this it will develop the technology towards 200-250 kW unit size. A unit of 250 kW could then be “repeated” for applications of around 1MW.

The overall efficiency of the CHP system is close to 90 per cent - more than double that of the electricity generated in classic power systems such as coal or gas plants. The characteristics of SOFC technology include a high operating temperature, the ability to use several different fuels - particularly biobased gases -, and ultra-low emissions.

Biogas powered SOFCs are arguably the world's least carbon-intensive and most efficient energy systems currently available. Compared with renewables like wind or solar power, which over their lifecycle release between 30 and 100 kg of CO2 per MWh of electricity generated, biogas fuelled SOFCs can generate negative emissions when the CO2 released during the decarbonisation of the fuel is sequestered. As such, the technology is a key solution that supports the development of sustainable, renewable and climate friendly energy.

The Wärtsilä biogas powered SOFC first reforms the carbonaceous methane gas into hydrogen, which is then fed to the cell (schematic, click to enlarge). Decarbonising the biofuel means its CO2 can be captured and stored. This, however, is a future development that is undergoing intensive research and will emerge when SOFCs are scaled up to power entire cities. An integrated CO2 grid would then transport the greenhouse gas to a safe storage site. The energy generated in this concept would be carbon-negative and actively remove CO2 from the atmosphere instead of merely preventing the release of new emissions, which is what ordinary renewables do.

Special features of SOFCs include:

• SOFC technology can operate in the temperature range of 650 - 800 °C, which allows the use of conventional materials in the balance of plant components.
• Since a fuel cell system has very few moving parts their service need will probably be considerably lower and system reliability higher when compared to conventional technologies.
• Planar SOFC products have the potential to reach a competitive cost level in mass production.
• Since pure hydrogen is costly and available only in limited quantities, a number of other fuels have been successfully used with SOFCs, such as methanol, natural gas, biogas, gasoline and even diesel oil and ethanol.
• In practice, the most potential fuels are natural gas, various types of biogas (methane from anaerobic digestion, or synthetic natural gas from biomass) and low-sulphur diesel. In stationary applications natural gas is widely used and the reforming of natural gas is conventional technology.

When low-cost manufacturing of SOFC products is achieved, it will change our way of producing electricity and consuming energy, say the organisers of the Green Housing Fair. The schematic of the Wärtsilä SOFC system illustrates how the fuel cell works. The company has developed extensive software to adapt a SOFC power unit into customer infrastructure.

Decentralisation
The significance of the capacity to use biogas increases in decentralized energy production. The benefits of decentralized energy production include more efficient utilization of local sources of energy, shorter transport distances for fuels and reduced energy transmission losses:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: biogas :: biomethane :: hydrogen :: solid oxide fuel cell :: emissions :: carbon-negative :: decentralisation :: combined heat-and-power :: district heating :: Finland ::

Biogas-based fuels are energy sources compliant with sustainable development. In addition to landfills, biogas is generated in agriculture and water treatment plants from a wide variety of organic materials.

Biomethane can be obtained from two main conversion processes: either the material is anaerobically digested via biochemical processes, or raw biomass is thermochemically transformed via a process known as gasification. In the first case, the term 'biogas' or 'landfill gas' is most commonly used; in the latter case, experts speak of 'synthetic natural gas' (SNG) or 'green gas'.

Bio-based gases can be made from virtually any type of biomass, ranging from dedicated energy crops to manure and various streams of agricultural, municipal and industrial waste.

Long-term clean energy strategy
The development of fuel cell technology is a part of Wärtsilä's long-term development strategy for cleaner and sustainable energy production technologies. The fuel cell unit for the fair site is Wärtsilä's first field application of the fuel cell technology.

The technology is in early demonstration phase where a low number of units are manufactured at high cost. Fontell says that it would cost around US$10 - 20,000/kW to buy the technology, which is still far from the target level. To be competitive, a fuel cell would need to cost no more than US$2,000-2,500/kW. Forecasts for 2015-2020 show the price falling to USD 1,000/kW, so the technology has potential to become competitive. But the cost development depends on both how the technology proceeds, and how fast the manufacturing volumes can be increased.


Since 2000, Wärtsilä has developed fuel cell technology for distributed power generation, and is today among the world’s front-line pioneers of this technology. The driving force is that the fuel cell technology will be one of the most promising energy technologies for decentralized power generation in the future.

Wärtsilä is involved in extensive domestic co-operation with Finnish R&D institutions and potential equipment suppliers, and participates in international co-operation in Europe, USA and Japan. System integration of the various technologies included in fuel cell systems is one of Wärtsilä’s expertise areas.

Wärtsilä is one of the leading companies in the world developing the specific SOFC technology. This development is supported by close collaboration with the Danish company Topsoe Fuel Cells A/S and VTT Technical Research Centre of Finland.


The Vaasa Housing Fair 2008 will be held at a beautiful location by the sea in Suvilahti, Vaasa, three kilometers from the Vaasa city center. The housing fair area consists of private houses, small housing associations and blocks of flats, all of which have been built in an urban style, while still succeeding in remaining close to nature.

The Vaasa Housing Fair to be held between 11 July and 10 August 2008 is a pioneer in the implementation of clean energy production processes for a restricted area. In addition to fuel cells, power and heat are produced with microturbines and from low-temperature heat collected from the sea bed using a geothermal heating pump.

References:
Energy & Enviro Finland: An unique fuel cell plant using landfill gas will produce energy for a Finnish housing fair - February 27, 2008.

Energy & Enviro Finland: Finnish Housing Fair pioneers in ecological living - February 27, 2008

Vaasa Housing Fair 2008.

Energy & Enviro Finland: Wärtsilä fuel cell system to power city of Vaasa - June 15, 2006.

Article continues

EnviTec Biogas awarded €30 million 30MW biogas contract in India to bring electricity to rural populations

German renewable energy company EnviTec Biogas AG of Lohne in Lower Saxony is gaining a foothold worldwide: the company has been awarded a €30 million (US$45.5 m) contract in the dynamically growing Indian market for the first time via a 50 percent joint venture in that country. The company will build 30 biogas power plants in Punjab to deliver renewable electricity and heat from biomass to rural populations across the state. The project is part of an ambitious rural electrification program that brings 20,000 jobs to the state.

India has gigantic energy requirements as one out of two households in rural regions does not have any electricity. With biogas plants as a non-centralized source of energy, we are able to make a real difference. - Olaf von Lehmden, CEO of EnviTec Biogas AG

The state-owned energy utility Punjab Energy Development Agency (PEDA) has placed an order with the consortium Green Planet Energy Pvt. Ltd, in which EnviTec is involved as the biogas partner, for the delivery of biogas facilities with an electricity output of 30 megawatts. The facilities deliver round-the-clock electricity and heat in a decentralised manner. Since biomass is stored solar energy, biogas plants offer reliable baseload power and can meet fluctuating demand at all times (schematic, click to enlarge).

The contract deals with biogas installations in Punjab, the country’s largest industrial state, its agricultural power house and one of the success stories of the Green Revolution. The order will be executed by EnviTec Biogas India Pvt. Ltd, located in Bangalore.

According to the PEDA, bioenergy is by far the renewable with the largest potential in the state. Biogas holds a potential of around 160MW and room for around 425,000 small household-scale biogas plants, biomass can contribute 1000MW of power, co-generation from the sugarcane sector 140MW and energy from MSW around 100MW (table, click to enlarge):
energy :: sustainability ::biomass :: bioenergy :: biofuels :: biogas :: methane :: baseload :: rural electrification :: poverty alleviation :: decentralisation :: Punjab :: India ::

With a total value of over €30 million, the contract provides for the delivery of 30 one-megawatt biogas plants, which are to be assembled across Punjab over the next two years. Work on building the first few plants is to commence in March of this year.

Generating electricity from biogas is part of a 160 megawatt renewable energies project which the consortium Green Planet Energy Pvt. Ltd, in which EnviTec Biogas is involved, has been awarded. The project as a whole will create around 15,000 jobs in Punjab including 5,000 in connection with the biogas plants.

EnviTec Biogas AG covers the entire value chain for the production of biogas - including the planning and turnkey construction of biogas plants as well as their commissioning. The company provides the biological and technical service and also offers the full plant and operating management. In addition, EnviTec also operates its own biogas plants. In Penkun, in the German state of Mecklenburg-Western Pomerania, EnviTec is currently constructing what it believes to be the world's largest biogas park with an electrical connected load of 20 megawatts.

Already today, EnviTec is represented through its own subsidiaries, joint ventures or sales offices in the Netherlands, Italy, the UK, Hungary, the Czech Republic, the Ukraine, Romania and India. In Belgium, Croatia and Greece, the company is already in the process of planning and constructing biogas plants.

In 2006 EnviTec generated revenues of €100.7 million and EBIT of €8.5 million. The EnviTec Group has about 250 employees. Since July 2007 EnviTec is listed on the Prime Standard segment of the Frankfurt Stock Exchange.

References:
EnviTec Biogas: EnviTec Biogas awarded major contract in India - February 28, 2008.

EnviTech Biogas products and services overview.

PEDA - Working towards a Sustainable Energy future.

Article continues

Surging interest in Fischer-Tropsch fuels signals end to "food versus fuel" debate

Those not familiar with the technological complexity of the bioenergy sector and the vast number of pathways through which biomass can be turned into biofuels, sometimes fail to see the bigger picture of the bioeconomy. Uninformed biofuel critics often get stuck in legitimate but simplistic food-versus-fuel debates or base their ideas on what's happening with old first-generation biofuels. They do not grasp the fact that there is a truly impressive, explicitly sustainable non-food biomass potential (1550 EJ by 2050) that can be converted efficiently into fuels via other techniques. And these techniques have now become competitive.

When plants grow, they invest most of their energy in growing lignin and cellulose - the most abundant organic polymers on Earth. Oils, starches and sugars in fruits which we as humans can digest, and which are currently used for problematic biofuels, make up only a tiny fraction of plant production. With record oil prices and increasing first-generation biofuel feedstock prices, it has now become more attractive to turn this abundant residual lignocellulosic biomass resource into fuels. The techniques to do so have become competitive which is why they are witnessing a worldwide surge in interest.

One of the most promising pathways is the thermochemical conversion of biomass into syngas which is then converted into liquid fuels via the Fischer-Tropsch process (biomass-to-liquids; biogas-to-liquids). This process can utilize any type of biomass as its feedstock - from desert shrubs to wood waste, from farm residues to municipal waste, from dedicated energy crops to forest thinnings, or even biogas - thus ending the 'food versus fuel' debate in one stroke. Fischer-Tropsch fuels from biomass are ultra-clean 'synthetic biofuels' that reduce emissions by up to 90% and burn cleaner than any other type of fuel.

Record oil prices as well as record corn prices have boosted interest in this technology, which, according to detailed analyses in the German context, is competitive with oil at US$65 per barrel. The Fischer-Tropsch process was invented in Germany in the 1930s when oil was scarce, and last year, the world's first dedicated BTL plant came online once more in that country. The concept as it is being developed there is supported by Volkswagen and Daimler, and draws on a two-step process: biomass is first transformed into bio-oil via fast pyrolysis, after which the oil is gasified and synthesised via the FT process (previous post). In principle, FT fuels do not need the pyrolysis step (which is introduced out of logistical reasons), as gasification and synthesis are the only processes needed to turn biomass into fuels.

Syntec Biofuel Inc., a leading developer of FT-catalysts, announces that it is indeed experiencing an unusual level of inquiries into its BTL catalyst technology (schematic, click to enlarge). The company attributes this to the rapidly growing interest in thermo-chemical biomass conversion technologies as a result of the rapidly changing economics of corn as a feedstock for ethanol.

Record corn prices are creating worldwide debate over the use of food stock as feedstock for fuel. From cost comparison models based on USDA data with the price at $4.98 a bushel - well below current prices - Syntec’s process has edged firmly ahead in competitiveness over corn fermentation methods.

The cost of corn today at $5.20 a bushel is making corn ethanol production only marginally profitable at their estimated production levels of 92 gpt. That is a conservative figure for us as we have already achieved 105 gallons with the potential for us to further increase yields up to 150 gpt. The equivalent cost of biomass feedstock based on a bushel of wood waste is approx. $1.00. We have therefore concluded that the cost of corn feedstock per gallon of alcohol is $1.89 whereas cost of biomass feedstock per gallon of alcohol is $0.33. - Syntec Biofuel statement

With its patented catalysts, Syntec Biofuel recently achieved a yield of 105 gallons (397.5 liters) of alcohols (ethanol, methanol, n-butanol and n-propanol) per ton of lignocellulosic biomass - an important milestone (previous post). In 2006, the company had targeted a yield of approximately 113 gallons (42.8 liters) per ton, and achieved 73 gallons (27.6 liters) last October. With the new yield achievement and Syntec's projections showing high commercial feasibility for its process, it is receiving interest from a rapidly growing number of interested parties.

Next-generation production techniques like those developed by Syntec Biofuel unlock the potential to turn virtually any type of biomass into fuels, thus ending the pressures on food markets. Biomass-to-liquids offers vast opportunities for hundreds of millions of farmers in poorer countries, where they can easily grow dedicated energy crops - grasses, shrubs, fast-growing trees - on low value, degraded land. By doing so, the world's poorest rural communities can lift themselves out of poverty and help end countries' reliance on catastrophically expensive oil. What is more, the substantial amount of agricultural and forestry residues that is currently burned or left to decay all over the world - a process responsible for large GHG emissions - has now become an attractive biofuel feedstock. Using it to produce ultra-clean synthetic biofuels greatly helps in the climate fight.

Scientists who developed the leading assessment model to analyse bioenergy potentials in countries and regions, have found that by 2050 around 1550 Exajoules of biomass will be available for use in the bioeconomy, under a highly efficient scenario. This potential is explicitly sustainable, as it is calculated by taking into account a strict zero deforestation rule, and by first allocating land to meet all food, fiber, feed and forest products needs of populations. 1550 EJ of sustainable bioenergy is roughly 6 times as much oil as is currently consumed by the entire world. The UN's Food & Agriculture Organisation (FAO) has taken this projection model - known as QUICKSCAN - as the basis for its own analyses which focus explicitly on food security:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: ethanol :: lignocellulose :: gasification :: Fischer-Tropsch :: biomass-to-liquids :: synthetic biofuels ::

The QUICKSCAN model, widely recognised as being the most robust and complete analytical framework, takes a bottom-up approach to estimate the sustainable bioenergy production potential. It first calculates and projects all food, fiber, fodder and forest product needs of growing populations, under different population growth scenarios. It then looks at the amount of land left for biofuels and bioenergy. This land base is explicitly taken to be non-forest land (no deforestation allowed) and sets aside land that is protected (conservation areas, natural parks, etc...). It then allocates different crops to different types of land after which a scenario component is introduced reflecting potential yield and land availability increases resulting from agronomical changes.

The end result of the projections is an amount of bioenergy that a given region can produce sustainably over time, while meeting all needs of growing local populations and without damaging the environment. Maximum potential for sub-Saharan Africa is 347 EJ per year by 2050; for South America and the Caribbean 279 EJ, for the C.I.S. and Baltic States 269 EJ (map, click to enlarge). Biopact has consistently based its discussion of the regional and global biofuels opportunity on these assessments and the research papers developed from it.

The scientists who developed QUICKSCAN have written several case studies about the medium to long-term future biofuels potential of countries like Mozambique and the Ukraine, or regions like the Baltics and West Africa. Interestingly, when they analyse the exportable potential, they consistently use Fischer-Tropsch as the base-line technology for their computations.

This is no coincidence. The medium to long-term future of biofuels is not in turning food into fuels. That is a primitive and inefficient process. When a crop grows, the plants spend most of their energy in growing non-food biomass. Grains, sugars or starches make up only a fraction of their production. Instead, plants invest their energy in growing ligno-cellulosic biomass, which we humans cannot digest. And it is this resource that can now be turned into fuels efficiently. Cellulose is the most abundant organic polymer on Earth. Lignin is the second most abundant.

References:
Syntec Biofuel: Syntec Biofuel says near record corn prices boosting interest in its waste biomass to ethanol process - February 27, 2008.

Biopact: Syntec Biofuel achieves yield of 105 gallons of synthetic alcohol per ton of biomass - February 15, 2008

Biopact: FAO unveils important bioenergy assessment tool to ensure food security, shows global biofuels potential - February 11, 2008

Biopact: Report: synthetic biofuels (BtL) and bioenergy efficient, competitive and sustainable in Germany - September 22, 2007

Biopact: German consortium starts production of ultra-clean synthetic biofuels -
June 23, 2007

Biopact: German Energy Agency: biomass-to-liquids can meet up to 35% of Germany's fuel needs by 2030 - December 15, 2006

Article continues

Researchers find why junipers are drought tolerant; relevance for the bioeconomy

The emerging bioeconomy's success is partly based on a stringent analysis of the regional availability of biomass resources that can be transformed efficiently into energy, biofuels, green chemicals and bioproducts. Large drought-stricken and semi-arid environments are taken up in this geospatial analysis, as these zones could in the future become suitable regions to grow newly developed, drought-tolerant crops. But before scientists start greening the desert, more research is needed into the mechanisms that allow some plants to thrive in water-starved environments.

Researchers from Duke University have contributed to this work by finding the hydraulic mechanism responsible for the unusual drought resistance of junipers. Junipers are coniferous plants in the genus Juniperus of the cypress family Cupressaceae. There are between 50-67 species of juniper, widely distributed throughout the northern hemisphere, from the Arctic to tropical Africa and to the mountains of Central America.

An ability to avoid the plant equivalent of vapor lock and a favorable evolutionary history may explain the unusual drought resistance of junipers, some varieties of which are now spreading rapidly in water-starved regions of the western United States, the Duke University study has found. The new report is published in the American Journal of Botany's online edition.

According to Robert Jackson, professor of global environmental change and biology at Duke's Nicholas School of the Environment and Earth Sciences junipers are the most drought-resistant group that has ever been studied.

The researchers examined 14 species from the U.S. and the Caribbean, all relatively drought-resistant. Even the trees in the mountains of Jamaica that get hundreds of inches of rain a year, belong to the drought tolerant group.

The plants have been expanding for about 100 years in some places, and drought plays a role in this process. Recent droughts have decimated pinyon pine populations in pinyon-juniper woodlands of the Southwestern U.S. but left the junipers relatively unscathed. Many juniper species - including several popularly known as cedars - are invading drier habitats and increasing in abundance where they already exist by surviving droughts that other conifers cannot.

To understand why junipers are so successful, Jackson's graduate student Cynthia Willson and Duke associate biology professor Paul Manos assessed structural and genetic features in the 14 species that can explain their special drought tolerance. They found a key structural adaptation in junipers: resistance to what scientists call "cavitation" - a tendency for bubbles to form in the water-conducting xylem tissues of plants:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: drought-tolerance :: water stress :: xylem :: juniper :: semi-arid :: arid :: desert ::

Water is sucked through xylem tissues under a partial vacuum, almost like a rubber band being stretched out. The drier the conditions, the greater the tension on that 'rubber band' and the more likely that it will snap. If it snaps, air bubbles can get into the xylem.

The scientists found that xylem tissues of juniper species tend to be reinforced with extra woody material to prevent rupture. Such rupturing can introduce bubble-forming air either through seepage from adjacent cavities or by coming out of solution from the water itself.

They also determined that the more cavitation-resistant Juniper species have thicker but narrower leaves - a trait known as low specific leaf area (SLA) - and live primarily in the western United States.

According to Cynthia Willson, the study's first author, who having completed her Ph.D. at Duke is now a student at North Carolina State University's College of Veterinary Medicine, plants in drier environments typically have lower SLA. She and the team found that junipers from the driest environments were more drought resistant and also had the lowest SLA.

Their research found that the most cavitation-resistant species is the California juniper, which grows in California's Mojave Desert, while the least resistant is the eastern red cedar - the most widespread conifer in the relatively-moist eastern U.S.

While less drought-tolerant than other junipers, eastern red cedars still handle dry spells well and are in fact invading into Midwestern states including Nebraska. Juniper species growing in wet parts of the Caribbean also benefit from drought tolerance because they tend to grow in shallow, rocky soils that don't hold a lot of water.

In parts of the Southwest undergoing an extended drying period, junipers are edging out another hardy, water-thrifty conifer - the pinyon pine. These trees are both very drought-resistant, but the pinyons aren't as resistant as the junipers are.

The scientists further investigated how and where these tree types evolved their collective drought tolerance by analyzing each juniper species' DNA. That analysis found that junipers evolved into different species relatively recently, separating into eastern and western groups - technically called "clades."

The center of diversity for junipers is in arid regions of Mexico. The fact that many juniper species seem to be more drought-resistant than necessary for their current range suggests that a common ancestor of those two clades was also quite drought-resistant.

The work was funded by the National Science Foundation, Duke University and the Andrew W. Mellon Foundation.


Note, the importance of biomass resources in semi-arid and arid environments should not be underestimated. Harvesting drought-tolerant shrubs from deserts to use them as a bioenergy source for energy is already competitive in some cases.

Recently, the VTT (one of Europe's largest research organisations) released a report about the invasive Acacia species that thrive on 10 million hectares of desert land in Namibia. They found that the biomass can be harvested profitably and holds a very large potential.

If Namibia were to harvest all the shrubs, which can be done in an efficient manner, it would obtain an amount of renwable energy 400 times greater than all its current energy needs (previous post).

Picture: Juniperus californica, the most drough-tolerant of the 14 different juniper species studied.

References:
Cynthia J. Willson, Paul S. Manos and Robert B. Jackson, "Hydraulic traits are influenced by phylogenetic history in the drought-resistant, invasive genus Juniperus (Cupressaceae)", American Journal of Botany, 2008, 95:299-314.

Eurekalert: Why juniper trees can live on less water - February 27, 2008.

Biopact: Researchers: invasive bush biomass in Namibia has high energy production potential - January 14, 2008

Article continues

Scientists find biodiesel blending often inaccurate; new radiocarbon screening technique offers precise measurements

While sampling blended biodiesel fuels purchased from small-scale retailers, researchers at the Woods Hole Oceanographic Institution found that many of the blends in the U.S. do not contain the advertised amount of biofuel. The marine scientists happened upon the discrepancy while studying the potential effects of a biodiesel spill in the marine environment. As a consequence, they developed an extremely precise radiocarbon-based calibration method for determining if the balance of biofuels and petroleum is correct. The new research was published online on February 27 in the journal Environmental Science and Technology.

Marine chemist Chris Reddy and colleagues sampled pure biodiesel and blends from more than a dozen distributors across the United States. When testing fuels listed as 20 percent biodiesel (commonly known as B20), they found that the actual percentage of biofuel ranged from as little as 10 percent to as much as 74 percent. Only 10 percent of samples met the specifications for biofuel blends required for vehicles of the U.S. Department of Defense, one of the leading consumers of the products.

Pure biodiesel (B100) is a chemically prepared mixture of animal fats and vegetable oils, and it is often used in modified diesel engines. Biodiesel “blends” combine B100 with traditional petroleum-based fuels in a manner that allows them to be used in regular diesel engines. Retailers commonly sell blends that are 20 percent biodiesel (B20) or 5 percent (B5), while all diesel fuels sold in the state of Minnesota are actually B2 (2 percent biofuel), in accordance with state standards.

Proponents of such fuels claim that they are more environmentally friendly because they emit less pollution—such as sulfur, particulates, and hydrocarbons — and may be less toxic for the environment when spilled.

Biodiesel is a great product if used properly, and it could turn out to be an important alternative fuel. There is a lot of good feeling about biodiesel, but if we are going to sell it, we have to make sure what is being sold is accurately prepared. It is a matter of credibility and consumer confidence. - Chris Reddy, lead author, associate scientist in the WHOI Department of Marine Chemistry and Geochemistry

Biodiesel blends are often made by local distributors through simple “splash blending,” whereby ingredients are poured together into a container in their respective amounts. The intent is that the simple act of pouring will ensure proper mixing.

But biodiesel is naturally thicker and more viscous than petroleum-based diesel, so it may be settling into separate layers within fuel tanks (like a mixture of milk and chocolate syrup, or fruit juice and alcohol). Reddy and colleagues also pointed to simple human error — poor math, measurement, or stirring — as a possible reason for the inconsistencies:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: biodiesel :: fuel blending :: radiocarbon ::

Improper blending of biofuels could lead to engine problems from drivers in cold climates, Reddy noted, because it could freeze or clog fuel lines. Most auto manufacturers recommend against using mixtures greater than B20, though the reasons are unclear.

Reddy believes the discrepancies could harm consumer confidence in the product, which is sometimes sold at a premium price over traditional petroleum fuels. There could also be financial issues related to taxation and tax credits for biofuel providers and consumers.

The United States currently has a voluntary standard for proper preparation of blended fuels, but no enforcement. The nation does have an enforceable standard for pure biodiesel.

The new fuel blending research builds on a 2004-2005 study by the National Renewable Energy Laboratory (NREL) that suggested some national-scale manufacturers were having a hard time producing proper blends of biofuel.

Radiocarbon measuring technique
Reddy and colleagues worked with WHOI senior scientist Bill Jenkins and colleagues at the National Ocean Sciences Accelerator Mass Spectrometer facility to develop an extremely precise radiocarbon-based calibration method for determining if the balance of biofuels and petroleum is correct. The new method relies on the fact that petroleum is “radiocarbon dead” (contain no radiocarbon), while biofuels are enriched with radioisotopes that plants absorb from Earth’s atmosphere and soil.

The calibration method accounts for the differences in chemical makeup of different types of oils, such as canola, coconut, soybean, or animal fats. This method also allows for a direct quantification of the amount of renewable carbon that is emitted from vehicles, which will aid researchers in determining the true environmental value of switching to biofuels.

The Woods Hole Oceanographic Institution is a private, independent organization in Falmouth, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the oceans and their interaction with the Earth as a whole, and to communicate a basic understanding of the ocean's role in the changing global environment.

References:
Christopher M. Reddy, Jared A. DeMello, Catherine A. Carmichael, Emily E. Peacock, Li Xu, and J. Samuel Arey, "Determination of Biodiesel Blending Percentages Using Natural Abundance Radiocarbon Analysis: Testing the Accuracy of Retail Biodiesel Blends". ASAP Environ. Sci. Technol., 10.1021/es071814j Web Release Date: February 27, 2008

WHOI: New Research Suggests Biofuel Blending is Often Inaccurate - February 28, 2008.

Article continues