Clearing the Land

The rice harvest is finally over for my neighbor, and what’s left are the rice stalks.  They started cutting them down on Monday of this week, clearing the land of one rice paddy, and they still have two more paddies to go.  I’m not sure what his plan is for the rice straw.  In some States, such as California, there is a market for rice straws and what people use these for are erosion control, formulated animal feed, animal bedding, construction materials, door cores, paper/pulp, packaging material, fuel/chemicals, energy, and compost.

Since his is on a smaller scale, I think he might use it as compost, which is one of the alternative uses for the rice straw mentioned above, this is done by tilling the rice straw into the soil and with the help of rain water, this will decompose the straw through time and help enrich the soil for next planting season.

What I find interesting is the use for fuel such as ethanol, and a group of Taiwanese scientists have developed a project that obtains ethanol from rice straw. The project is successful in the laboratory, and will move to a test plant by the end of 2009.  Ethanol produced from rice straw is 99.5 percent pure, and does not compete with edible feedstock such as corn and wheat, and the straw is a secondary product, and does not affect food supply and also help the farmers’ economy. The only drawback of this process is its elevated price, currently estimated at $0.67 per liter, although this amount could be cut in half in the near future.

According to Wikipedia, the largest single use of ethanol is as a motor fuel and fuel additive, and the largest national fuel ethanol industries is in Brazil, which gasoline sold in Brazil contains at least 25% ethanol and most of their ethanol comes from the sugar cane plantations.

Dual-fuel gas station at Sao Paulo, Brazil. Alcohol (ethanol) and G gasoline photo by Mario Roberto Duran Ortiz

With the high price of fuel, I would think that ethanol would be good for us, but 100 % pure ethanol is not approved as a motor vehicle fuel in the US, and when added to gasoline, ethanol reduces ground-level ozone, but according to The Clean Fuels Report comparison of fuel emissions, the data shows that ethanol exhaust generated 2.14 times as much ozone as does gasoline exhaust. When this is added into the custom Localized Pollution Index (LPI) of The Clean Fuels Report the local pollution, i.e. that contributes to smog, is 1.7 on a scale where gasoline is 1.0 and higher numbers signify greater pollution. This issue has been formalized by the California Air Resources Board in 2008.

This made me to think that our vehicle is not made with ethanol fuel in mind for it to generate more pollution than gasoline.  I’m hoping that with the rise of oil prices and depletion of our natural resources, this will motivate people to find alternative fuel and develop better vehicle to accommodate it.