<body><script type="text/javascript"> //<![CDATA[ try{(function(a){var b="http://",c="news.mongabay.com",d="/cdn-cgi/cl/",e="img.gif",f=new a;f.src=[b,c,d,e].join("")})(Image)}catch(e){} //]]> </script> -------------------
Contact Us       Consulting       Projects       Our Goals       About Us
home / Archive
Nature Blog Network


    Spanish company Ferry Group is to invest €42/US$55.2 million in a project for the production of biomass fuel pellets in Bulgaria. The 3-year project consists of establishing plantations of paulownia trees near the city of Tran. Paulownia is a fast-growing tree used for the commercial production of fuel pellets. Dnevnik - Feb. 20, 2007.

    Hungary's BHD Hõerõmû Zrt. is to build a 35 billion Forint (€138/US$182 million) commercial biomass-fired power plant with a maximum output of 49.9 MW in Szerencs (northeast Hungary). Portfolio.hu - Feb. 20, 2007.

    Tonight at 9pm, BBC Two will be showing a program on geo-engineering techniques to 'save' the planet from global warming. Five of the world's top scientists propose five radical scientific inventions which could stop climate change dead in its tracks. The ideas include: a giant sunshade in space to filter out the sun's rays and help cool us down; forests of artificial trees that would breath in carbon dioxide and stop the green house effect and a fleet futuristic yachts that will shoot salt water into the clouds thickening them and cooling the planet. BBC News - Feb. 19, 2007.

    Archer Daniels Midland, the largest U.S. ethanol producer, is planning to open a biodiesel plant in Indonesia with Wilmar International Ltd. this year and a wholly owned biodiesel plant in Brazil before July, the Wall Street Journal reported on Thursday. The Brazil plant is expected to be the nation's largest, the paper said. Worldwide, the company projects a fourfold rise in biodiesel production over the next five years. ADM was not immediately available to comment. Reuters - Feb. 16, 2007.

    Finnish engineering firm Pöyry Oyj has been awarded contracts by San Carlos Bioenergy Inc. to provide services for the first bioethanol plant in the Philippines. The aggregate contract value is EUR 10 million. The plant is to be build in the Province of San Carlos on the north-eastern tip of Negros Island. The plant is expected to deliver 120,000 liters/day of bioethanol and 4 MW of excess power to the grid. Kauppalehti Online - Feb. 15, 2007.

    In order to reduce fuel costs, a Mukono-based flower farm which exports to Europe, is building its own biodiesel plant, based on using Jatropha curcas seeds. It estimates the fuel will cut production costs by up to 20%. New Vision (Kampala, Uganda) - Feb. 12, 2007.

    The Tokyo Metropolitan Government has decided to use 10% biodiesel in its fleet of public buses. The world's largest city is served by the Toei Bus System, which is used by some 570,000 people daily. Digital World Tokyo - Feb. 12, 2007.

    Fearing lack of electricity supply in South Africa and a price tag on CO2, WSP Group SA is investing in a biomass power plant that will replace coal in the Letaba Citrus juicing plant which is located in Tzaneen. Mining Weekly - Feb. 8, 2007.

    In what it calls an important addition to its global R&D capabilities, Archer Daniels Midland (ADM) is to build a new bioenergy research center in Hamburg, Germany. World Grain - Feb. 5, 2007.

    EthaBlog's Henrique Oliveira interviews leading Brazilian biofuels consultant Marcelo Coelho who offers insights into the (foreign) investment dynamics in the sector, the history of Brazilian ethanol and the relationship between oil price trends and biofuels. EthaBlog - Feb. 2, 2007.

    The government of Taiwan has announced its renewable energy target: 12% of all energy should come from renewables by 2020. The plan is expected to revitalise Taiwan's agricultural sector and to boost its nascent biomass industry. China Post - Feb. 2, 2007.

    Production at Cantarell, the world's second biggest oil field, declined by 500,000 barrels or 25% last year. This virtual collapse is unfolding much faster than projections from Mexico's state-run oil giant Petroleos Mexicanos. Wall Street Journal - Jan. 30, 2007.

    Dubai-based and AIM listed Teejori Ltd. has entered into an agreement to invest €6 million to acquire a 16.7% interest in Bekon, which developed two proprietary technologies enabling dry-fermentation of biomass. Both technologies allow it to design, establish and operate biogas plants in a highly efficient way. Dry-Fermentation offers significant advantages to the existing widely used wet fermentation process of converting biomass to biogas. Ame Info - Jan. 22, 2007.

    Hindustan Petroleum Corporation Limited is to build a biofuel production plant in the tribal belt of Banswara, Rajasthan, India. The petroleum company has acquired 20,000 hectares of low value land in the district, which it plans to commit to growing jatropha and other biofuel crops. The company's chairman said HPCL was also looking for similar wasteland in the state of Chhattisgarh. Zee News - Jan. 15, 2007.

    The Zimbabwean national police begins planting jatropha for a pilot project that must result in a daily production of 1000 liters of biodiesel. The Herald (Harare), Via AllAfrica - Jan. 12, 2007.

    In order to meet its Kyoto obligations and to cut dependence on oil, Japan has started importing biofuels from Brazil and elsewhere. And even though the country has limited local bioenergy potential, its Agriculture Ministry will begin a search for natural resources, including farm products and their residues, that can be used to make biofuels in Japan. To this end, studies will be conducted at 900 locations nationwide over a three-year period. The Japan Times - Jan. 12, 2007.

    Chrysler's chief economist Van Jolissaint has launched an arrogant attack on "quasi-hysterical Europeans" and their attitudes to global warming, calling the Stern Review 'dubious'. The remarks illustrate the yawning gap between opinions on climate change among Europeans and Americans, but they also strengthen the view that announcements by US car makers and legislators about the development of green vehicles are nothing more than window dressing. Today, the EU announced its comprehensive energy policy for the 21st century, with climate change at the center of it. BBC News - Jan. 10, 2007.

    The new Canadian government is investing $840,000 into BioMatera Inc. a biotech company that develops industrial biopolymers (such as PHA) that have wide-scale applications in the plastics, farmaceutical and cosmetics industries. Plant-based biopolymers such as PHA are biodegradable and renewable. Government of Canada - Jan. 9, 2007.


Creative Commons License


Sunday, January 07, 2007

Sweet potatoes and the carbohydrate economy

As the world moves away (at least conceptually) from the hydrocarbon economy and towards the 'carbohydrate economy', the search is on to find suitable plants that can be converted into the products of the future. With the basic chemical building blocks contained in biomass - sugars, starches, celullose, lignin - we can create a whole range of sustainable, biodegradable and clean products, from textiles and plastics, to green specialty chemicals, fuels and fibres.
Many plants have properties that make them suitable for different applications within this carbohydrate economy (or 'bioeconomy'), but some stand because of their high productivity, ease of processing or their special chemical properties.

The sweet potato (Ipomoea batatas L.) is such a plant (fact sheet). The tropical root crop (not to be confused with white potatoes) is an important staple for people in the South, but in China, the world's largest producer, it is grown as a livestock feed. Sweet potatoes thrive in many farming conditions, and can be grown in relatively poor soils with limited amounts of fertiliser. No major pests are known. The countries with the largest land base suitable for the crop are Brazil and the Democratic Republic of Congo. As we will show below, sweet potato lands are clearly located outside of rainforest basins - a major advantage compared to for example oil palm.

Starch = plastics, ethanol, biohydrogen
The tuberous roots of the crop contain very high levels of starch, which make sweet potatoes an interesing candidate for industrial applications. First and foremost, sweet potatoes will become a major ethanol feedstock (see below). In a way to diversify feedstocks away from food grains, the Chinese government is stimulating the use of sweet potatoes instead. Today, Taiwan's Council of Agriculture announced it is going to use sweet potatoes for ethanol in a pilot project, that may be extended to cover 220,000 hectares of the island's unused lands in the near future.

Auto manufacturer Toyota has already begun a large project to produce bioplastics and bioproducts from sweet potato. The crop is the key component of its "cradle-to-cradle" design philosophy. The leading car manufacturer opened a business in Indonesia, P. T. Toyota Bio Indonesia, entirely dedicated to the effort. Sweet potato starch can be turned into polylactic acid, from which plastics can be made. This sweet potato program was originally based on Professor Toyoki Kozai's research at the Chiba University Faculty of Horticulture, presented in a report for Toyota entitled "Sweet Potatoes to Save the Earth in the 21st Century." The main points of the report were: (1) the manufacture of biodegradable plastics from sweet potato starch will become common; (2) hydrogen derived from sweet potato alcohol will become an energy source for fuel cell and electric vehicles; and (3) Sweet potatoes would be developed as a livestock feed as an alternative to corn. Other Japanese researchers are working on biohydrogen production from sweet potato as well (see below).

The government of Ghana, in collaboration with international research organisations dealing with tropical agriculture, recently launched an industrial sweet potato program, aimed at producing ethanol and industrial starch. The program is explicitly presented in the context of energy security, 'saving forex', and poverty alleviation (as many rural jobs will be created).

So why exactly are some of the world's leading high tech businesses as well as governments with huge biofuel challenges in front of them looking into this crop? The reasons are relatively simple:
:: :: :: :: :: :: :: :: :: :: :: ::


High yields, low inputs
Even though sweet potatoes are commonly referred to as a "small farmer's crop", when they are grown on a large-scale, they yield very large amounts of biomass without the need for heavy investments in inputs. They can be harvested mechanically (which is a major advantage to other bioeconomy crops), and are easy to process into basic chemical building blocks.

Per kilogram, sweet potatoes yield some 40 to 50% more starch than corn, white potatoes and wheat. Per hectare, their starch productivity is 3 to 4 times higher than corn, and twice that of cassava.

When it comes to ethanol production, sweet potatoes are also easier to process than corn and require considerably less energy inputs. This results in a higher overall energy balance (or 'EROEI'). The few comparisons that are out there, show sweet potato as the leading 'first generation' ethanol crop.

(Ligno)cellulosic crops, like hybrid poplars and grasses, require a next-generation conversion process that is still in its infancy and costly. The starch contained in sweet potatoes on the contrary can be extracted easily and consequently fermented into alcohol. In short, because of its high ethanol yield per hectare, sweet potato makes for a crop that will compete for many decades to come, even when commercially viable cellulosic ethanol makes it onto the scene faster than expected.

Note that in the table above, no account was made of the residual biomass that can be used for power generation. Just as is the case with bagasse (the residue of crushed sugar canes), sweet potato stalks and leaves can be burned or used as a biogas feedstock. Ultimately, this residue biomass can be converted into cellulosic ethanol as well. The residue to product ratio for sweet potatoes is around 1 to 1, meaning that for each ton of tubers produced, 1 ton of biomass residues (stalks, leaves) remains.

Congo, forests
A quick look at agro-ecological land suitability for rainfed sweet potato teaches us that two countries stand out: Brazil and the Democratic Republic of Congo. But these countries also happen to be the hosts of the world's largest rainforests. Agro-ecological zoning (AEZ) - a GIS method used to locate suitable land and climates for crops - however neatly shows that sweet potato (like cassava), explicitly grows outside of rainforest zones. To stress this point: rainforest zones are totally unsuitable for sweet potato.

A vast zone in Congo's south-east provinces of West- and East Kasaï, Maniema and Katanga, has a high concentration of 'very suitable', 'suitable' and 'moderately suitable' land (roughly the size of the UK), that would have the highest productivity for this crop on the planet. AEZ models show different land and yield outcomes according to different inputs and technology mixes. Under a low input model, Congo's land suitable for rainfed sweet potatoes amounts to around 71 million hectares; under a high input model, it equals around 103 million hectares. The brown, 'not suitable' zone on the map roughly matches Congo's rainforest basin.

Currently, some 5% of all potentially arable land is used in these provinces. Projections on the future land availability for sustainably produced energy and bioproduct crops, show that there will be an enormous potential left after the needs for food, fodder and fibre of the rapidly growing local populations is satisfied. In any case, at 10,000 liters of ethanol per hectare, and several tens of millions of hectares available in Congo alone, it is clear that sweet potato offers an opportunity for some of the world's poorest farmers, who live in this region, to work themselves out of poverty, provided an export oriented ethanol program based on the crop were to be introduced in the region.

More information:

Toyota: Realizing a Recycling-Oriented Society Through Agricultural Biotechnology.

Toyota: Sweet Potato Business.

Treehugger: Sweet! Potato Cars from Toyota, Jan. 13, 2005.

Yokoi H., Saitsu A. et al., Microbial hydrogen production from sweet potato starch residue, Journal of Bioscience and Bioengineering, Volume 91, Number 1, 2001, pp. 58-63(6) (reference).

On Ghana's program, see: Siaka Kofi Duffuor, Sweet Potato Can Be Developed As Foreign Exchange Earner, Ministry for Food and Agriculture, [*.pdf]

Taiwan's Council on Agriculture and its sweet potato ethanol plans (China Post, Jan. 6, 2007).

On Agro-Ecological Zoning: see the interactive land suitability map database for rainfed crops at the FAO's Land and Water Division: land suitability for rainfed cropping.

On Global Agro-Ecological Zoning in general, see the dedicated website, with maps, at the FAO.

On the exact numbers for AEZ per country and per crop, see the excel spreadsheets at the "Global Agro-ecological Assessment for Agriculture in the 21st Century" website of the International Institute for Applied Systems Analysis. This website presents a wealth of data (also available on CD-rom), on land suitability, productivity and sustainability for different crops in all countries. For the data on Congo, click > spreadsheets > additional. Then look for the data on sweet potato. No direct link, the excel spreadsheets open in the same window.

All data derived from GAEZ account for basic sustainability (taking into account soil erosion, sustainable use of water resources, etc...; Congo's land base for sweet potato, for example, was calculated by accounting for fallow periods to restore soils).

Article continues