According to the Zah study the total environmental impact of ethanol produced from sorghum in China is about 50% greater than gasoline. And, while GHG emissions are less than gasoline, such ethanol from sugar fails to meet the cutoff of 35% or less suggested by the European Commission.
Adapted from (S1).
Greenhouse-gas emissions are plotted against overall environmental impacts of 29 transport fuels, scaled relative to gasoline. The origin of biofuels produced outside Switzerland is indicated by country codes: Brazil (BR), China (CN), European Union (EU), France (FR), and Malaysia (MY). Fuels in the shaded area are considered advantageous in both their overall environmental impacts and greenhouse-gas emissions.
Within such a context of biofuel sustainability, the Biopact team presents “development of hybrid sweet cassava that grows well in open pastures, and in poor and acid soils, is pest and disease-tolerant and is optimized for sugar production.”
China has been part of the global sugar ethanol market since at least 2006. Sorghum, cassava and other biofuel crops are planted on lands that are unfit for grain production. According to AGENCE FRANCE-PRESSE via Biofuels Simon, in 2006, the agriculture ministry allocated land in Shangdong and Xinjiang Uygur Autonomous Region with the aim to produce 300 million tonnes of ethanol a year. The National Development and Reform Commission quoted Yang Jian, a director at the Ministry of Agriculture, as saying the program would start with sweet sorghum.
Without specific scientific analysis of the production of ethanol from cassava in China, the results generated by the Swiss scientists for sorghum only suggest an approximate benefit when compared to gasoline. Nevertheless, since cassava is a source of food, it would seem, like other agricultural crops, to be contraindicated, or, at the very least, circumspect as a fuel source due to its diversion of resources from food production and a corresponding impact upon food prices. Simon Robinson relayed a report from Reuters that China is facing a tapioca shortage. It “looks like demand has outstripped supply,” he noted, “which may hit the country’s bioethanol business.”
The state-owned Brazilian Agricultural Research Enterprise (EMBRAPA) and biotech researchers from the Chinese Academy of Tropical Agricultural Sciences (CATAS) have launched a program to cooperate in research on the use of a recently discovered type of cassava for biofuels.
Brazilian scientists have a large manioc germplasm bank in which sweet cassava mutants can be found that are highly suitable for ethanol production. Under the collaboration, China offers its rapid genome sequencing capacities to Brazil for further research into the new crop. The People’s Republic’s scientists indicated the country is thinking of switching from ordinary cassava – which is rich in starch – to the new and more easily convertible sugar varieties instead.
Flickr Photo: cfarivarEMBRAPA met with a Chinese science delegation at its headquarters in Brasilia last month, to kick off the technical cooperation between the two countries’ leading tropical agriculture research institutions. The program is headed by two EMBRAPA units: Genetic Resources and Biotechnology – Pastures (Planaltina – DF); and Agroenergia e Mandioca e Fruticultura Tropical (Bioenergy from Manioc and Tropical Fruticulture).
The Chinese committee visited EMBRAPA Mandioca e Fruticultura, in Cruz das Almas, in Bahia state, as well as EMBRAPA Pastures’ manioc germplasm bank which contains a collection of 500 representative cassava accessions.
The technical cooperation is aimed at exploring the development of hybrid sweet cassava that grows well in open pastures, and in poor and acid soils, is pest and disease-tolerant and is optimised for sugar production, explains EMBRAPA Genetic Resources and Biotechnology researcher Luiz Joaquim Castelo Branco Carvalho. In 1996, the researcher and his team identified natural cassava mutants rich in glucose in the Amazon. After fundamental genetic and biochemical research the researchers now conclude that this type of sweet cassava has great potential for fermentation into alcohol.
John Melo, CEO of Amyris, which Scientific American recognized as “Business Leader of the Year” in 2007, perceives the Brazilian sugar industry as offering the most “viable, sustainable” way to make biofuels today.Cassava improvement programs in Brazil have so far focused on the production of flour and starch. The new varieties of sweet cassava can diversify the market for the crop and open new markets, says Carvalho. One of these markets is alcohol production, because the glucose-rich cassava allows for the direct conversion of the roots’ sugars into ethanol. This fact contrasts with the conventional process in which starchy cassava tubers first need to undergo a hydrolysis treatment. The sweet cassava variety skips this step.
China currently cultivates around half a million hectares of cassava, of which 200,000 are destined for ethanol production. The People’s Republic chose cassava as one of its future biofuels crops, because it is considered to be an industrial plant, and not a food crop. According to Wenquan Wang, researcher at CATAS, cassava has gained importance because of its low environmental footprint and because it has a well established industrial presence. “For 30 years, cassava was a staple for many Chinese people, later it became a crop for animal feed, and nowadays 60% of the entire harvest is destined for the industrial production of starch, 20% goes to ethanol and the remainder is turned into pig feed.”
