TheAsahi Shimbun reports that in looking at alternative fuels, nothing goes to waste when Honda Motor Co. gets involved. The automaker is hard at work trying to produce bioethanol from rice straw and other inedible waste, a welcome development given that food prices are rising as demand grows for biofuel material.

And while new fuels using bioethanol are quickly being introduced around the world as eco-friendly substitutes for gasoline, there are drawbacks to the effort. For example, concern is growing over a global shortage of crops, such as corn and sugarcane, traditional food sources that are now being used to power motor vehicles. The shortage has triggered price increases in some food staples.

Now, Honda, working with the Research Institute of Innovative Technology for the Earth (RITE), a foundation established by the government and private companies, is jointly developing a new method of producing the alcohol fuel using the parts of crops that humans do not eat.

The new technology uses cellulose extracted from rice straw. It is estimated that currently 70 percent of the country‘‘s rice straw gets thrown away. The fuel is made by first extracting the cellulose from the rice straw by boiling it in a pressure cooker. The cellulose is then melted into a syrup.

Conventionally, a yeast fungus was added to the syrup to change the sugar into alcohol but institute researchers developed a bacteria, known as the "RITE strain" that more efficiently turns sugar into alcohol. The addition of the RITE strain to the syrup results in a liquid that is around 7 percent alcohol. When distilled into 99.5 percent or more alcohol, it can be used for auto fuel.

Using the RITE strain, 250 grams of alcohol is produced from 1 kilogram of rice straw. The production efficiency is 10 to 20 times greater compared with that of the conventional yeast fungus method.

Still, Yoshikazu Fujisawa, 54, a senior chief engineer at Honda R&D Co. is not satisfied. He said the RITE technology won‘‘t serve as a countermeasure for global warming if it uses large amounts of oil fuel in the boiling process. Fujisawa has introduced new pressure cookers and other processing equipment to produce the ethanol in larger quantities and also reduce the burden on the environment. He is now working to raise the production efficiency of the bioethanol.

"I want to reduce costs and also lower the energy required for production by 20 percent from the current level," Fujisawa said.

Another goal for Honda is to have the technology working in traditional farming areas across Japan within the next two to three years. It says local residents would be able to produce bioethanol made from rice straw at farms in their areas to power the vehicles.

Biofuel, which contains bioethanol, is spreading throughout the United States and Brazil as more people use it as an automotive fuel. Bioethanol is considered neutral in terms of carbon dioxide because the greenhouse gas it emits during combustion is offset by the amount the plants absorbed during the process of photosynthesis.

In Japan, test sales of gasoline with a 3-percent bioethanol content started in and around Tokyo in April. The gasoline is already being sold at gas stations in Miyakojima island in Okinawa Prefecture.