Agriculture – Part 7: Growing Food, Feed or Fuel on the Farm

Biofuel Isn’t Something New

Humanity discovered how to control fire hundreds of thousands of years ago with wood and dung our primary fuel sources. Tens of thousands of years ago our ancestors discovered that wood could be converted to charcoal. Peat fires to this day are still a principle heating source in parts of the world. And animal dung provides humans living in desert regions with an alternative to wood.

Humanity has also grown crops and converted them to fuel. Olive oil lit the lamps of Greek and Roman antiquity.

The age of whaling provided whale oil for lamps burning in the homes of European and North America well into the 19th century.

I found this Henry Ford quote that goes back to 1925.

“There is enough alcohol in one year’s yield of a hectare of potatoes to drive the machinery necessary to cultivate the field for a hundred years.”

In World War II, Germany took Henry Ford’s advice and partly fueled their transportation and industry using alcohol derived from potatoes.

In that same war Great Britain experimented with grain-derived alcohol as a fuel for its war industries.

To this day 9-10% of human energy consumption comes from the burning of biomass for heating and cooking. And the two primary sources remain animal dung and wood.

The Biofuel Dilemma Today

From left to right, soybeans, corn and sugarcane are grown for food, feed and fuel

Creating biofuels today Brazil, the United States, and other countries are using soybeans, corn, sugarcane, sugar beets and other crops instead of potatoes and grain (Germany and Britain’s experiment) to create ethanol, an alcohol-based fuel. The harvesting of these crops for fuel is changing the mix of what farmers in the Western World grow today and will be growing in greater quantities for the forseeable future. That’s because in a world where population growth is driving the need for greater food production, and energy demand is driving biofuel development, farmers are finding themselves asking the following question.

“Should I grow more food, feed or biofuel crops?”

The argument for food is obvious. The Developing World lacks the capacity to deliver enough domestically grown food to meet population demand. China, India, most of Africa, Southwest Asia and Russia are net importers of food.

The argument for feed seems obvious as well. The increasing demand for meat and dairy products in the Developing World and the continuing demand in the Developed World represents a thriving export and domestic opportunity for countries such as the United States, Canada, Australia, Argentina and those in Western Europe.

The argument for biofuel is more about geopolitics and security. In the United States and Europe, biofuel production means less dependence on imported oil for energy use. For the United States, corn represents the primary biofuel source.  Corn usage for ethanol has increased annually for a number of years at a rate greater than the total national corn yield.

The second largest North American source for biofuel is vegetable oils. One-third of all the Canola grown in Europe and North America is used for industrial lubricants or biodiesel.  Soybeans, largely grown for domestic and foreign food consumption, are being converted to oil for industrial use.

In the Farm Foundation Issue Report – What’s Driving food Prices in 2011? it reports on changes in agricultural land use from 2005-2006 to 2010-2011. Most significantly, the top three crops are those being grown for ethanol, biodiesel and industry.

Net Changes in Land Usage for 13 Major crops from 2005-6 to 2010-11

American energy policy contributes dramatically to the growth in demand for biofuels. In 2010 corn-based ethanol production in the United States reached 13 billion gallons. The corn-based ethanol target for 2015 is 15 billion gallons. The U.S. government has set a target of 36 billion gallons by 2022.

A 2009 feasibility study by the Sandia National Laboratories in Livermore, California, looks at achieving a target of 90 billion gallons of ethanol by 2030, of which 75 billion gallons would come from non-food crops and 15 billion from corn, soybean and other food or feed crops. Farm-based biofuel sources included agricultural residue such as corn stover and wheat straw. Farms could also harvest switchgrass and short-rotation woody crops such as poplar and willow.

Biofuel’s Near Future – the Next 20 Years

Cellulosic Ethanol

The Sandia study sees almost all of  the capacity for biofuel growth coming from cellulose.  Cellulosic ethanol  can be derived from low-value residue of industrial processes such as sawdust and scrap wood. Add to this the byproduct residue of farming and the harvesting of woody shrubs and grasses from land not under cultivation. In deriving ethanol from “waste” sources the competitive dilemma for farmers to choose among food,  feed and biofuel crop production is mitigated. The pressure to plant more traditional crops on marginal land goes away.

Cellulosic ethanol production has its challenges. Producers need to find an economical way to break  down the woody fibres, called lignin, to get to the cellulose to convert it to sugars and ultimately ethanol. By studying the digestive processes of herbivores such as cattle, or studying the way termites break down wood fibre, scientists are developing better conversion processes. The first large-scale cellulosic ethanol plants in North America are expected to come on stream in 2013 able to pump out several million gallons. Getting to 75 billion gallons from this source requires continuous investment.

Algenol

Creating ethanol from algae, called algenol, represents another biofuel option that takes the farm out of the energy production equation. The process involves growing algae in waste water, seawater and brackish water near existing manufacturing or fossil-fuel power plants where CO2 is a byproduct.  Capturing and pumping the CO2 into the water along with exposure to sunlight generates algae growth with ethanol the byproduct. Called photobioreactors, these facilities can be located anywhere human activity is generating sufficient CO2 output to justify putting an algae-to-ethanol generator in place. One company in the forefront of commercializing algae-t0-ethanol is aptly named Algenol. Their goal is 20 billion gallons per year of ethanol by 2030.

Biodiesel

Biodiesel is another biofuel that can be produced from soybeans and other agricultural products. But biodiesel can also be produced in very novel ways, from the left over vegetable oil in a deep fryer, from kitchen grease, from rendered animal fats, and what typically is seen generally as waste oil.

Biodiesel has several advantages over other biofuels. It is biodegradable. It helps take care of waste oils that normally get dumped into domestic water supplies or landfill as garbage. It is less toxic and provides fewer emissions than conventional diesel fuel.

Germany and the United States are the world leaders in the production of biodiesel. In 2005 the United States produced 75 million gallons. Comparably Germany in 2006 reported sales figures of 600 million gallons. American output was forecast to reach 1-2 billion gallons by 2010.

Worldwide Biofuel Growth

In 2010 global biofuel production equaled 54.6  million gallons per day. This number is expected to more than double to 113.4 million gallons per day by 2030. Biofuels will generate 8.5% of global energy by 2030, up from 7.7% in 2005.

Energy in the 21st Century – Part 7: From Biomass to Biofuels

Humanity has relied on biofuels since first mastering fire. Until the Industrial Revolution peat, wood, charcoal, whale oil, and plant oils represented the biofuels of choice. Fossil fuels began with coal. Fossil fuel crude oil and oil byproducts were a 19th century technical achievement. The automobile and internal combustion engine turned gasoline, formerly a discarded byproduct of oil refining into a major energy source. Industrial societies became fossil fuel addicts while the rest of the world, largely agrarian, continued to rely on biomass to fuel fires to generate heat and energy.

Biomass continues to be a major source of fuel. But the major consumers of energy are fossil-fuel junkies and addicts and it is these economies that are rethinking biomass as a fuel source because oil and fossil fuels like coal are seen as finite and non-renewable energy sources. It’s not just about climate change. It’s about dependency on a resource that is becoming more difficult to access.

If industrial society in the 21st century is to ween itself from fossil-based fuels, then it needs to develop alternatives. What are these alternative biomass fuel sources? How economical will it be to use these to replace crude oil and coal? Do biofuels help us deal with global climate change by lowering our carbon footprint?

Biofuels and Climate Change

What makes biofuels attractive is the fact that one can argue they are carbon neutral. Unlike mined and refined fossil fuels adding carbon to the environment, biofuels are contained within plants that absorb carbon dioxide from the air as they grow and release the carbon when finally consumed as fuel. This means they are carbon neutral. By theoretically not adding extra carbon to the atmosphere biofuels are environmentally sustainable and non contributors to global warming.

But is that truly the case? What about the industrial processes needed to synthesize the fuel from the biomass. What kind of energy is needed for that? If you are burning natural gas or oil to make biofuels then it is hard to claim that biofuels are carbon neutral.

EROEI as a Measure of Biofuel Effectiveness

Any time it requires more energy to produce a source of energy than the energy you get out of it one should pause and consider the implications. EROEI stands for Energy Return on Energy Invested. Here’s a handy chart that was inspired in part from an article I read, “Getting a Decent Return on Your Energy Investment,” written by Dana Visalli in 2006. The list includes conventional and unconventional energy resources and I must add that not all “experts” agree with these EROEI values or even what makes up EROEI calculations.

1. Hydrogen EROEI of 0.5:1
2. Corn Ethanol EROEI of 1.2:1
3. Oil Sands EROEI of 2:1
4. Corn Biodiesel  EROEI of 3:1
5. Geothermal EROEI of 3:1
6. Switch Grass Cellulosic Ethanol EROEI of 4:1
7. Solar thermal EROEI of 4:1
8. Nuclear EROEI of 5:1
9. Sugar Cane Ethanol EROEI from 8.3:1 to 10.2:1
10. Solar PhotoVoltaic EROEI of up to 9:1
11. Coal EROEI of up to 10:1
12. Natural Gas EROEI of 10:1
13. Hydropower EROEI of 12:1
14. Wind EROEI of 19:1
15. Oil Conventional EROEI currently estimated average 25:1 but declining

Food Crops As Biofuel Sources

If this isn’t the craziest of all developments that have occurred in the last 20 years — ethanol and biodiesel from corn is more about subsidizing American farmers to grow far more corn than can be consumed as food within the North American market. The issue is what to do with the surplus? What started off as corn for corn flakes is now a trillion-dollar enterprise churning out corn byproducts in foods, pharmaceuticals, cosmetics, animal feed and industrial chemicals.

Does that make corn a good biofuel source? Let’s look at the numbers.

• In 2009 the United States harvested more than 333 million metric tons of corn.
• It takes an acre field of corn, yielding 7,110 pounds (3,225 kg) to make 328 gallons (1240.61 liters) of ethanol.
• That amounts to 26.1 pounds of corn for a U.S. gallon or  3.1 kg  to produce a liter. For the most part, only the corn kernels are used in producing biofuels.
• If ingested as food the calorie equivalent would be approximately 3,280.
• The average recommended daily calorie intake for women is 1,940 calories per day and for men 2,550.
• So 1 liter of biofuel eats more corn than an average human being’s daily calorie requirement.
• EROEI for corn ethanol is 1.2:1 which means you gain very little net yield
• EROEI for corn biodiesel is 3:1 which isn’t much better

How far can you go on 1 liter of biofuel? Not very far and considering how many people on the planet ingest less than the 2,000 calories daily it is difficult to rationalize using a food crop for biofuel.

It is another matter if only waste from the plant was used in creating biodiesel. Since 2009 a number of companies and universities started experiments with stover, the name for corn waste. We’ll talk about stover when we address other biofuel plant sources.

Sugar Cane as a Biofuel Source

It would seem that sugar cane makes a bit more sense as a biofuel source than corn kernels. First of all it has a better EROEI. Also, we can all do with a little less sugar in our diets. But let’s take a closer look at this miracle biofuel resource.

Brazil is the largest producer of biofuel from sugar cane. In 2011 Brazil will harvest more than 500 million tons of sugar cane. From each ton of cane the harvesters recover 135 kilograms (60 lbs) of sugar. That same ton of cane can produce 75 liters (20 gallons) of ethanol.

Other than sugar and ethanol, how is sugar cane used as an agricultural product? The tops of the sugar cane plant are used as animal fodder. The fibrous residue, called bagasse, is used as a fuel source in sugar manufacturing, paper and fertilizer. Molasses is a byproduct of the refining process. Molasses derivatives are used in vinegar, cosmetics, pharmaceuticals, solvents and industrial cleaners, and food additives.

Sugar cane, therefore, seems less controversial as a biofuel source than corn kernels. But in Brazil, sugar cane is being produced on land cleared of rainforest, savannas and grasslands usually by slash and burn methods creating huge atmospheric carbon output and contributing to increases in CO2.

Sugar cane plantations in Brazil are large and heavily treated with chemicals to stave off fungi and insect, plant and animal pests. Harvesting techniques involve burning of the cane stalks and the release of more greenhouse gases. Also since the cane is cut to the root, the soil is exposed and subject to erosion with little carbon sequestration. As demand for biofuels increase sugar cane plantings displace food crops. In recent years Brazil has seen corn and black-bean production drop by 10% because of sugar cane. When weighing the pluses and minuses of sugar cane versus corn as a biofuel source all the above has to be considered. And it is not a pretty picture if we are considering this as a resource to reduce carbon emissions while weaning ourselves off fossil fuels.

Other Biofuel Plant Sources that are Not Food Crops

There are many plant sources to consider when looking for biofuel sources. There are always whales and other animal sources but our society generally looks upon such choices as being particularly inhumane.

By no means an exhaustive list, let’s look at 3 biofuel sources that don’t compete with food and may prove to be far less controversial than corn and sugar cane.

Stover

When corn is harvested the remaining stalks, leaves, husks and cobs can be used to produce cellulosic ethanol. There are many challenges to overcome before stover replaces corn kernels as a primary biofuel source but there is promising news on one front, the creation of enzymes that can digest the residue and convert it. In a recent article in Scientific American, Steven Ashley talks about a new fermentation process that renders ethanol from stover.

The good thing about stover is the mass that can be collected from a corn field is equal in tonnage to the yield from harvesting corn kernels. So the resource is quite abundant and inexpensive when compared to a bushel of corn.

The bad news is simply this. The cost of production, the loss of soil nutrients, the added fertilizer requirements, the loss of the resource as animal feed stock, all have to be factored into the overall cost. How does removing stover impact soil retention and quality? What will it do to field runoff and potential erosion? Agricultural researchers are experimenting to find what is just the right amount of stover to remove and when to remove it so that it doesn’t have a negative impact.

And after all of this will the EROEI be worth it even if it matches existing numbers for corn biodiesel and ethanol?

Switch Grass

Since 2008 the U.S. Department of Energy has been funding a number of biofuel pilot projects using switchgrass with a goal to get a better resource than corn for producing biofuels. So far the EROEI for switchgrass is proving to be no better than corn. But it is believed that EROEI can be improved to approach 4:1.

What makes switch grass more attractive as a biofuel resource?

1. It has a higher biomass yield per acre than corn. In many areas it can yield two harvests in one growing season.
2. It requires much less water and less fertilizer to grow.
3. It grows on marginal lands that are unsuitable for other agricultural production.
4. It can be harvested using conventional haying equipment.
5. It is a perennial, self-seeding, a good environmental habitat for native wildlife, and excellent for soil retention.

What challenges remain?

1. No current processes are yielding EROEIs approaching 4:1.
2. If switch grass is harvested regularly will long-term yields decline.

Algae

Everything you ever wanted to know about algae can be found at Oilgae, an industry site dedicated to making algae the biofuel resource of choice. Algae is not one type of plant. There are micro and macro algaes. Seaweed is a macro algae but it is micro algaes that represent the greatest potential for energy crops. What makes algae attractive over corn, sugar cane or switch grass?

1. Micro algae can yield as much as 56,000 liters (15,000 U.S. gallons) of oil per hectare a year. That is a much higher yield than what can be obtained from field crops.
2. Micro algae can be grown in lots of environments where traditional crops would never thrive.
3. Micro algae can be grown under conditions which are unsuitable for conventional crop production.
4. Micro algae is a carbon trap extracting CO2 from the atmosphere.

With all these positive things to say about algae why aren’t we ramping up production? Here are a few of the reasons why we are not.

1. Consistency of product remains a challenge. Micro algae can easily be contaminated in open ponds. That’s why many pilot projects are in closed pond environments.
2. Yields are highly variable as the industry tries to develop optimal conditions for maximum yields.
3. The largest byproduct of the algae production process is water. With 1,000 parts of water to 1 part algae, that’s a lot of water.
4. Bio-engineered algae represents a potential environmental issue should genetically altered species contaminate the natural world.