GAS FROM GRASS Will an ordinary prairie grass become the next biofuel? CHAPTER 29 BIOFUELS

GAS FROM GRASS Will an ordinary prairie grass become the next biofuel? After reading this chapter you will know: About biofuels, their sources, and trade-offs About controversies attached to land allocation for ethanol and the potential for cellulose from plants as a part of our energy strategy Learning Outcomes 29

Main Concept Biofuels offer potential replacement for fossil fuels but, like all alternatives, require additional research and continued discussion of pros and cons. GAS FROM GRASS Will an ordinary prairie grass become the next biofuel?29

29 Case: Nitrogen is one of the limiting factors for plant growth. As we adjust to growth patterns changing with the climate, biomass production from prairie grasses might be a potential source for better biofuels than the croplands we currently use. Test plots in Cedar Creek Reserve, Minnesota, have revealed more than just the role of nitrogen in plant production. Accidental diversity within test plots revealed surprising increases in productivity. Conventional monocultures and the process of clearing land for crops reduces primary production and releases CO 2 into the atmosphere.

Biofuels are a potentially important alternative to fossil fuels29 Burning biomass such as cornstalks and weeds is the way we've claimed energy from nature as long as man has used fire. Only in recent history have we shifted our use to non-renewable fossil fuels. Increasing our use of biofuels— those fuels made from biomass— is one of our current strategies for reducing fossil fuel dependence. Terms: Biofuels Biomass Feedstock Perennial Annual Fuel crops Bioethanol Biodiesel

Biofuels come from unexpected sources29 Materials of biological origin can be burned directly or converted to bioethanol or biodiesel. Direct biomass energy comes from burning waste materials or crops specifically grown for fuel production.

Biofuels come from unexpected sources29 Materials of biological origin can be burned directly or converted to bioethanol or biodiesel. Direct biomass energy comes from burning waste materials or crops specifically grown for fuel production.

Biofuels come from unexpected sources29 Materials of biological origin can be burned directly or converted to bioethanol or biodiesel. Direct biomass energy comes from burning waste materials or crops specifically grown for fuel production.

Biofuels come from unexpected sources29 Materials of biological origin can be burned directly or converted to bioethanol or biodiesel. Direct biomass energy comes from burning waste materials or crops specifically grown for fuel production.

Biofuels come from unexpected sources29 Bioethanol is the product of distillation and fermentation. These processes capture concentrated energy stored in biomass of fuel crops like corn and sugarcane. Since ethanol is highly corrosive and somewhat less efficient than other biofuels, it is used mainly as an additive.

Biofuels come from unexpected sources29 Biodiesel is a different kind of biofuel produced from high-oil crops like soybeans and sunflowers, or from restaurant fry grease.

Biofuels come from unexpected sources29 Biodiesel is a different kind of biofuel produced from high-oil crops like soybeans and sunflowers, or from restaurant fry grease.

Biofuels come from unexpected sources29 Biodiesel is a different kind of biofuel produced from high-oil crops like soybeans and sunflowers, or from restaurant fry grease.

Biofuels come from unexpected sources29 Biodiesel is a different kind of biofuel produced from high-oil crops like soybeans and sunflowers, or from restaurant fry grease.

Biofuels come from unexpected sources29 Collection of used vegetable oil from restaurants to recycle into biodiesel fuel. Biodiesel is more energy rich than ethanol, and can be used directly in diesel engines. Another advantage of biodiesel is that it can take waste that was once a liability and convert it into an asset. Small biodiesel cooperatives are testing the potential around the country.

Biofuels come from unexpected sources29 Collection of used vegetable oil from restaurants to recycle into biodiesel fuel. Garbage and agricultural, industrial, and food waste can be used to create a variety of biofuels. Process

Biofuels come from unexpected sources29 Collection of used vegetable oil from restaurants to recycle into biodiesel fuel. Garbage and agricultural, industrial, and food waste can be used to create a variety of biofuels. Product

Turning grass into gas is less environmentally friendly than it sounds29 The Energy Policy Act, passed by Congress in 2005, required that the country boost its biofuel production to 7.5 billion gallons by Over time, experts realized that the initial attempts to create biofuels weren’t much more environmentally friendly than the fossil fuels they were intended to replace. Corn is one of the most energy-intensive crops to grow and harvest. Another worry is that natural lands are being converted to farmland for biofuels, endangering native species. Biofuel crops also displace food crops and drive up the price of corn.

Turning grass into gas is less environmentally friendly than it sounds29

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Tilman’s experiments showed the importance of biodiversity29 Terms: Monoculture Tilman’s group dried and weighed plants from their experimental strips to determine how much biomass was being produced. Biomass results showed that plots with 16 species of plants were 238% more productive than monoculture plots. Biodiverse ecosystems that are naturally adapted to their environment are the most productive. Ethanol is made from starch in one of our monocrops—corn. We have the infrastructure in place to ramp up corn production even though it is not as efficient a source of energy as other crops and loses productivity without diversity.

Tilman’s experiments showed the importance of biodiversity29 Bioethanol can also be produced from the cellulose forming cell walls in plants. Cellulosic ethanol produced from crops like switchgrass have become important alternatives to corn ethanol. In addition to avoiding the controversy of food vs. fuel in land use, switchgrass is a perennial and sequesters carbon in the root system after harvest.

Tilman’s experiments showed the importance of biodiversity29 Life cycle analysis comparing low-input, high-diversity grassland plants.

Tilman’s experiments showed the importance of biodiversity29 All biofuels produce less greenhouse gas emissions than conventional fossil fuels.

There is another rising biofuel star: Algae29 Research being conducted to use algae in production of pharmaceuticals inspired a group of scientists at the University of California to look at the same algae as a potential biofuel. Algae are predicted to generate 30 times more oil per acre than other plants used for biodiesel.

There is another rising biofuel star: Algae29 Algae can be grown as a foodstock for biodiesels. Biodiesel is the most common product, but the sugars in algae can also be extracted to produce ethanol.

There are many reasons why biofuels have not solved our dependence on fossil fuels29 Ethanol can be produced from the biological fermentation of any plant material. Food sources like grains and sugarcane are easily broken down by yeast fermentation, whereas plant material high in cellulose is more challenging to break down.

There are many reasons why biofuels have not solved our dependence on fossil fuels29 Ethanol can be produced from the biological fermentation of any plant material. Food sources like grains and sugarcane are easily broken down by yeast fermentation, whereas plant material high in cellulose is more challenging to break down.

There are many reasons why biofuels have not solved our dependence on fossil fuels29 Ethanol can be produced from the biological fermentation of any plant material. Food sources like grains and sugarcane are easily broken down by yeast fermentation, whereas plant material high in cellulose is more challenging to break down.

There are many reasons why biofuels have not solved our dependence on fossil fuels29 Ethanol can be produced from the biological fermentation of any plant material. Food sources like grains and sugarcane are easily broken down by yeast fermentation, whereas plant material high in cellulose is more challenging to break down.

Multiple solutions will be needed to help replace fossil fuels29

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Despite ongoing controversies and setbacks, the future of biofuels looks bright29 Hopes are that if biofuels can be use properly, we can balance our needs for food, energy, and a habitable and sustainable environment.

PERSONAL CHOICES THAT HELP29

UNDERSTANDING THE ISSUE29

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ANALYZING THE SCIENCE29

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EVALUATING NEW INFORMATION29

MAKING CONNECTIONS29