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    According to Salvador Rivas, the director for Non-Conventional Energy at the Dominican Republic's Industry and Commerce Ministry, a group of companies from Brazil wants to invest more than 100 million dollars to produce ethanol in the country, both for local consumption and export to the United States. Dominican Today - May 16, 2007.

    EWE AG, a German multi-service energy company, has started construction on a plant aimed at purifying biogas so that it can be fed into the natural gas grid. Before the end of the year, EWE AG will be selling the biogas to end users via its subsidiary EWE Naturwatt. Solarthemen [*German] - May 16, 2007.

    Scania will introduce an ethanol-fueled hybrid bus concept at the UITP public transport congress in Helsinki 21-24 May 2007. The full-size low-floor city bus is designed to cut fossil CO2 emissions by up to 90% when running on the ethanol blend and reduce fuel consumption by at least 25%. GreenCarCongress - May 16, 2007.

    A report by the NGO Christian Aid predicts there may be 1 billion climate refugees and migrants by 2050. It shows the effects of conflicts on populations in poor countries and draws parallels with the situation as it could develop because of climate change. Christian Aid - May 14, 2007.

    Dutch multinational oil group Rompetrol, also known as TRG, has entered the biofuel market in France in conjunction with its French subsidiary Dyneff. It hopes to equip approximately 30 filling stations to provide superethanol E85 distribution to French consumers by the end of 2007. Energy Business Review - May 13, 2007.

    A group of British organisations launches the National Forum on Bio-Methane as a Road Transport Fuel. Bio-methane or biogas is widely regarded as the cleanest of all transport fuels, even cleaner than hydrogen or electric vehicles. Several EU projects across the Union have shown its viability. The UK forum was lauched at the Naturally Gas conference on 1st May 2007 in Loughborough, which was hosted by Cenex in partnership with the NSCA and the Natural Gas Vehicle Association. NSCA - May 11, 2007.

    We reported earlier on Dynamotive and Tecna SA's initiative to build 6 bio-oil plants in the Argentinian province of Corrientes (here). Dynamotive has now officially confirmed this news. Dynamotive - May 11, 2007.

    Nigeria launches a national biofuels feasibility study that will look at the potential to link the agricultural sector to the automotive fuels sector. Tim Gbugu, project leader, said "if we are able to link agriculture, we will have large employment opportunity for the sustenance of this country, we have vast land that can be utilised". This Day Onlin (Lagos) - May 9, 2007.

    Brazilian President Luiz Inácio Lula da Silva meets with the CEO of Portuguese energy company Galp Energia, which will sign a biofuel cooperation agreement with Brazilian state-owned oil company Petrobras. GP1 (*Portuguese) - May 9, 2007.

    The BBC has an interesting story on how biodiesel made from coconut oil is taking the pacific island of Bougainville by storm. Small refineries turn the oil into an affordable fuel that replaces costly imported petroleum products. BBC - May 8, 2007.

    Indian car manufacturer Mahindra & Mahindra is set to launch its first B100-powered vehicles for commercial use by this year-end. The company is confident of fitting the new engines in all its existing models. Sify - May 8, 2007.

    The Biofuels Act of the Philippines has come into effect today. The law requires all oil firms in the country to blend 2% biodiesel (most often coconut-methyl ester) in their diesel products. AHN - May 7, 2007.

    Successful tests based on EU-criteria result in approval of 5 new maize hybrids that were developed as dedicated biogas crops [*German]. Veredlungsproduktion - May 6, 2007.

    With funding from the U.S. Department of Labor Workforce Innovation for Regional Economic Development (WIRED), Michigan State University intends to open a training facility dedicated to students and workers who want to start a career in the State's growing bioeconomy. Michigan State University - May 4, 2007.

    Researchers from the Texas A&M University have presented a "giant" sorghum variety for the production of ethanol. The crop is drought-tolerant and yields high amounts of ethanol. Texas A & M - May 3, 2007.

    C-Tran, the public transportation system serving Southwest Washington and parts of Portland, has converted its 97-bus fleet and other diesel vehicles to run on a blend of 20% biodiesel beginning 1 May from its current fleet-wide use of B5. Automotive World - May 3, 2007.

    The Institut Français du Pétrole (IFP) and France's largest research organisation, the CNRS, have signed a framework-agreement to cooperate on the development of new energy technologies, including research into biomass based fuels and products, as well as carbon capture and storage technologies. CNRS - April 30, 2007.

    One of India's largest state-owned bus companies, the Andra Pradesh State Road Transport Corporation is to use biodiesel in one depot of each of the 23 districts of the state. The company operates some 22,000 buses that use 330 million liters of diesel per year. Times of India - April 30, 2007.

    Indian sugar producers face surpluses after a bumper harvest and low prices. Diverting excess sugar into the ethanol industry now becomes more attractive. India is the world's second largest sugar producer. NDTVProfit - April 30, 2007.

    Brazilian President Luiz Inacio Lula da Silva and his Chilean counterpart Michelle Bachelet on Thursday signed a biofuel cooperation agreement designed to share Brazil's experience in ethanol production and help Chile develop biofuels and fuel which Lula seeks to promote in other countries. More info to follow. People's Daily Online - April 27, 2007.

    Italy's Benetton plans to build a €61 million wood processing and biomass pellet production factory Nagyatád (southwest Hungary). The plant will be powered by biogas. Budapest Sun - April 27, 2007.

    Cargill is to build an ethanol plant in the Magdeburger Börde, located on the river Elbe, Germany. The facility, which will be integrated into existing starch processing plant, will have an annual capacity of 100,000 cubic meters and use grain as its feedstock. FIF - April 26, 2007.

    Wärtsilä Corporation was awarded a contract by the Belgian independent power producer Renogen S.A. to supply a second biomass-fuelled combined heat and power plant in the municipality of Amel in the Ardennes, Belgium. The new plant will have a net electrical power output of 3.29 MWe, and a thermal output of up to 10 MWth for district heating. The electrical output in condensing operation is 5.3 MWe. Kauppalehti - April 25, 2007.

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Thursday, May 17, 2007

The bioeconomy at work: buildings made of biomass ash?

As the use of biomass in large power plants becomes more common, a problem arises: what to do with the large amount of ash that results from burning the renewable energy source? In Europe and the US (database of current co-firing projects, at the IEA Bioenergy Task 32 on Combustion and Cofiring) and China, biomass is being used more and more often to generate electricity and heat, either in dedicated power plants that exclusively burn the green resource (such as the Les Awirs plant in Belgium), or co-fired with coal in existing plants. This biomass can be divided into several categories, ranging from heavily contaminated wood (e.g. demolition wood that contains scraps of glass, steel, plastics, paint etc...) and agricultural residues (such as rice husks), to pure, clean biomass from dedicated energy crops.

Depending on the category, the resuling ash types contain different concentrations of heavy metals such as nickel, vanadium, arsenic, cadmium, barium, chromium, copper, molybdenum, zinc, lead, and selenium. Though these elements are found in extremely low concentrations, their presence warrants careful and often costly waste treatment procedures to prevent leaching into the soil.

For this reason, scientists have been searching for alternatives to landfill disposal. Amongst them is Jan Pels from the Energy Research Center of the Netherlands (ECN), who led a research team working on a project called 'BIOAS' [*.pdf/Dutch, English abstract]. While a group of scientists from the University of Leeds did similar work on rice husk ash [*.pdf] which has some importance for the developing world. Finally, scientists from the Brigham Young University in Utah worked on analysing whether biomass ash can replace cement [*.pdf] in concrete, like coal ash has been used for this purpose for quite a while now. All teams obtained encouraging results: biomass ash can be used to build houses and skyscrapers. What is more, the product can replace building materials that have a heavy CO2 footprint. Utilizing this waste stream from the combustion of biomass also boosts the sustainability of solid biofuels.

The Dutch team found a way to use biomass ash in combination with a heavy petroleum residue, the carbon of which can thus be fixed, whereas the British researchers looked at a combination of waste materials, including ash from burned rice husks, to make what they call a 'Bitublock'. They are also working on a concrete-like building material based on vegetable oil as a binder ('Vegeblock'). Finally the American team found that fly ash from pure wood and switchgrass matches the properties of coal ash, and can replace Portland cement in concrete:
:: :: :: :: :: :: :: :: ::

The BIOAS Project
BIOAS started with the ideal scenario which says that ash from clean, uncontaminated biomass should be returned to the soil where the biomass grew so that nutrients and minerals are recycled.

However in many cases recycling is not possible, for example with ash from contaminated biomass (e.g. demolition wood), ash where the origins of the biomass cannot be traced (becoming common with increased trade of feedstocks), or in cases where the land owner does not want the ash returned (e.g. natural reserves or farm land).

In these cases, alternative forms of sustainable utilisation had to be found. ECN investigated the possibilities for the use of ash generated from clean biomass in power production and concluded that for nearly all biomass ash a technically acceptable solution can be found.

Construction materials
The largest potential lies in several kinds of construction material ranging from filler in concrete, to bricks, or even synthetic basalt. Particular kinds of ash can be used as raw material for fertilizers. Black, carbon-rich ash from gasification could even be used as fuel, to replace cokes, or as activated carbon in a multitude of applications.

However many of the solutions are more expensive than landfill disposal because of the small amounts produced and strong fluctuations in composition. Recycling ash to the soil where the clean biomass originated is already possible in Scandinavia and Austria, but in the Netherlands such specific regulations for recycling of biomass ash do not exist and are unlikely to be implemented soon. The situation could improve if large-scale imports of clean biomass begin. In this case, Dutch legislation needs updating to enable export of the ash back to the country (and soil) of origin. However, when long distance trade is involved (such as imports from dedicated energy plantations in Africa), returning the ash would become too expensive.

Fixing carbon while storing biomass ash
For the Netherlands, using biomass ash in building material is a more likely scenario. Bottom ash from biomass combustion is already used as a building material (granulate 0-40). But in the BIOAS Project, gasification ash was successfully tested as filler in a promising concrete-like building material with heavy petroleum residue as binder, called 'C-FIX'. The ECN is currently investigating other routes to produce innovative building materials from biomass ash.

C-FIX (derived from 'carbon fixation') is a product developed by Shell Global Solutions and marketed by subsidiary C-fix BV. The starting material is an extremely hard, carbon-rich residue obtained from petroleum refining. This residue is currently added to marine bunker fuels and heavy fuel oil used in power plants. Upon burning it, an extremely high amount of carbon dioxide is released, making it a very polluting fuel.

A more environmentally friendly way of using the material is to use it as a component in building materials. This way, the carbon is fixed during the lifecycle of the product and doesn't contribute to atmospheric CO2 pollution.

The properties of C-FIX range between those of cement concrete and asphalt. It is strong but flexible thermoplastic binder that resists acids and bases. Moreover, the binder can not only be combined with traditional aggregates such as sand and filler, but with other aggregates such as recycled asphalt, river sludge and waste granulates.

The BIOAS project studied the possibility of using biomass ash as an aggregate for C-FIX, and results were encouraging. The test material conformed to Dutch norms on leaching of macro and micro elements. Five different building blocks made from different types of biomass ash also showed excellent physical properties.

The conclusion of the project was that biomass ash can be used successfully as a building material composed of binders such as C-FIX.

Bitublock and Vegeblock
C-FIX relies on a heavy petroleum product, the carbon of which is fixed. However, in another development, researchers from the University of Leeds found that ash from rice husks can be used safely as a concrete filler, not unlike coal fly ash, which is already used for this purpose.

The team led by John Forth worked at developing a building block made almost entirely of recycled glass, metal slag, sewage sludge, incinerator ash, and pulverised fuel ash from power stations, including ash from rice husks.

Dr Forth, from the School of Engineering, believes his Bitublock has the potential to revolutionise the building industry by providing a sustainable, low-energy replacement for around 350 million concrete blocks manufactured in the UK each year. "Our aim is to completely replace concrete as a structural material", he explained.

Bitublocks use up to 100% waste materials and avoid sending them to landfill, which is quite unheard of in the building industry. What's more, less energy is required to manufacture the Bitublock than a traditional concrete block, and it's about six times as strong, so it's quite a high-performance product.

The secret ingredient is bitumen, a sticky substance used to bind the mixture of waste products together, before compacting it in a mould to form a solid block. Next the block is heat-cured, which oxidises the bitumen so it hardens like concrete.

This makes it possible to use a higher proportion of waste in the Bitublock than by using a cement or clay binder. The Bitublock could put to good use each year an estimated 400,000 tonnes of crushed glass and 500,000 tonnes of incinerator ash.

Meanwhile, a 'Vegeblock' is also under development, based on using vegetable oil as the binder. This would make for the greenest of all concrete-like building materials. The researchers found that waste vegetable oil can easily be mixed with recycled aggregates at ambient temperatures to produce a very workable, easily compactable product. Contrary to the Bitublock, he visual appearance of Vegeblocks is highly attractive in that the units reflect the colour of the aggregates used in the manufacturing process.

The Vegeblock's color changes according to the type of vegetable oil that is used during its manufacture

Curing is required to fully oxidise the vegetable oil and hence stabilise the block. However, due to totally different chemical composition of vegetable oils as opposed to bitumens (mineral oil derivatives), the curing regime is far shorter. Typically curing a Vegeblock only consists of heating for 12 to 24 hours at 120 to 160 °C. The properties of the Vegeblock are at least equivalent to concrete blocks.

Biomass ash as a replacement for cement in concrete
Shuangzhen Wang and Larry Baxter from the Department of Chemical Engineering at the Brigham Young University recently presented their "Comprehensive Investigation of Biomass Fly Ash in Concrete" at the Advanced Combustion Engineering Research Center's congress.

They first looked at the strength and microscopy of coal ash concrete, then at the strength and kinetics of concrete with a biomass fly ash filler, and finally at the durability of the material. The analysis looked at five different forms of concrete based on fly-ashes obtained from co-firing coal with respectively switchgrass and saw dust from pure wood, in different ratios.

Their conclusions on biomass fly ash look as follows:
  • Equal strength to that of pure cement concrete from 1 month to 1 year after mixing.
  • Significant pozzolanic reaction up to one year in concrete.
  • 3-6 times the strength of coal ash samples with Ca(OH)2.
  • Comparable strength with Ca(OH)2 even to pure cement.
  • Quantitative kinetics has been derived
  • Matches or outperforms coal ash in reducing ASR expansion
This means that biomass fly ash, in this case derived from pure wood and switchgrass, can potentially be used as a replacement for Portland cement in the production of concrete.

Without taking things too far, developments in using biomass ash for construction materials are very encouraging, which opens opportunities for the developing world. There, large streams of agricultural residues (such as rice husks) as well as the potential for dedicated biomass crops is available. If this renewable energy resource were to be combusted in dedicated and efficient biomass power plants there, an important component of affordable and reliable building materials would become available and the sustainability of solid biofuels would be enhanced.

Image: the Sears Tower in Chicago, long the tallest building in the US, was built from concrete containing coal fly ash. Will a green Sears Tower ever be built from concrete based on biomass fly ash?

More information:
ECN: Askwaliteit en toepassingsmogelijkheden bij verbranding van schone biomassa (BIOAS) [*.pdf] - April 2004.

BioEnergy Network of Excellence: "A House built of biomass ash" [*.pdf], Newsletter, Volume 1, Issue 3, July 2005.

John Forth, "Non-Traditional Binders for Construction Materials" [*.pdf], IABSE Henderson Colloquium, Cambridge, 10-12 July 2006 Engineering for Sustainable Cities.

Eurekalert: New homes rise from rubbish - April 2, 2007.

C-FIX website.

Shuangzhen Wang, Larry Baxter, Comprehensive Investigation of Biomass Fly Ash in Concrete: Strength, Microscopy, Quantitative Kinetics and Durability [*.pdf] - Brigham Young University ACERC annual conference, February 28, 2007.


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