Sweet Sorghum Boosts the Efficiency of Ethanol

Ethanol has some distinct advantages as a fuel, and sweet sorghum promises even better input/output ratios
By Benjamin Burroughs | July 21, 2011

Traditionally agriculture has been in food/feed stock production for humans and livestock, but as we move farther into this new century, fuel crops have become part of the equation. There are crops that can be used for ethanol production that have better input/output ratios than corn. According to university studies, the ratio of input to output using corn is 1-1.25. When looking at ethanol production, the output ratio should be substantially higher than the input for a crop to be deemed efficient. One such crop that has a higher ratio is sweet sorghum at 1-8.

In addition to having a higher ratio, the cost of production for sweet sorghum is lower than for corn. For every bushel of corn produced, there must be a pound of nitrogen put out for fertilization. Distributing 130 to 250 pounds of nitrogen per acre, sometimes more, can consume a large portion of the funds for production. Sweet sorghum requires only 40 to 60 pounds of nitrogen per acre, which can be accomplished by using a simple crop rotation that includes a winter cover crop that fixates nitrogen into the soil.

For every bushel of corn around 2.7 to 2.8 gallons of ethanol are produced. Another consideration is that corn is harvested only once a year and has a long growing season, often more than 140 days. If a farmer were only growing corn for ethanol production and had 150 bushels an acre, he would help produce 405 to 420 gallons of ethanol per acre. This may seem like a good number, but sweet sorghum has the potential of producing up to 800 gallons of ethanol per acre. Another advantage is sweet sorghum can be harvested twice and, in some regions, three times a year. If there were year-round operations, they could achieve over 1,000 gallons of ethanol per acre. That is at least twice that of corn production, and it has lower input costs resulting in higher profit margins for producers.

Some farmers/ranchers think that land has to be taken out of one particular production scheme and put into this one. The best practice is to have enough acreage to help offset your own fuel cost. The next time you are at the gas pump filling your vehicle, preferably from empty for this calculation, multiply the total by 26. This number should give you a rough estimate of how much you spend a year on fuel. This number will not be exact since everyone’s driving habits differ; it is only for a quick calculation based on filling your vehicle completely every two weeks. If you fill your vehicle each week multiply by 52 fill ups a year.

There are more than six million new vehicles sold each year in the United States alone. With the current ethanol demand based on 10 percent blend, that is an additional 600,000 gallons of ethanol that is going to be needed. (The 600,000 gallons of fuel is based on the assumption that a car was not traded in for the purchase of the new car.) With the ever-increasing price of fuel, a cheaper source has to be put online for consumers. The people of the United States have not had to pay for such high gas prices since the spike in the summer of 2008. When the prices spiked between $5 and $6 per gallon of diesel or gasoline, the working class was made to choose between eating or filling up their gas tank to get back and forth to work. It was a dark couple of weeks that OPEC countries pushed the barrier to see where the American people would break at the pump, and how much we will pay in order to keep our mobility.    

There is no reason for this to happen ever again, but there must be local support of growing crops for fuel production. Helping to stabilize the fuel economy is vital to not only national security, but to the infrastructure of the society we live in. Every American wants to own their own vehicle and drive from place to place. It is our freedom to choose when and where we want to travel. Having fuel prices at the current level of $3.65 to $4 per gallon is going to hit tourist towns and economies the hardest, not to mention the trucking industry, which ships most of our goods  from warehouse to storefront. Each person that touches the goods adds a penny here or a penny there, and that is partly why we have seen increases at the grocery store.

The next topic is one that stirs up controversy every time it is discussed: reduction of greenhouse gas (GHG) emissions. By using ethanol in the fuel today, we have only scratched the surface on cutting GHG emissions. Many people would think that the majority of pollution comes from industry. This is due to the stacks billowing with clouds of what is perceived to be smoke, but is actually steam, in most cases. Most of the pollution comes from everyone driving their own personal vehicle anywhere they travel.  Having ethanol in the fuel has helped to reduce GHG emissions, but there needs to be a larger effort for significant changes to occur. Using E85 has helped to reduce GHG, carbon dioxide (CO2) and carbon monoxide (CO) emissions in flex-fuel vehicles (FFVs) by as much as 70 percent. With a 70 percent reduction, smog-encased cities like Los Angeles could help to make a better environment for all of their inhabitants. By using E85 in larger quantities, our fuel can help the environment, and decrease our dependence on foreign oil for fuel. The carbon cycle illustration shows how growing our own fuel will benefit the environment.

Understanding how carbon travels in our atmosphere is crucial to understanding that the more fuel produced from petroleum the higher the levels of CO2, CO and GHGs in our atmosphere. To help decrease current levels in our atmosphere, alternatives are needed that have lower carbon content, plus a source that can absorb carbon and take it out of circulation.  Plants are the best at this process through photosynthesis and respiration.  They take in CO2 and release oxygen.

Ethanol production helps to ensure our fuel independence, decrease our dependence on foreign oil sources, decrease pollution and greenhouse gas emissions, have a healthier environment for children, increased economic activity that creates jobs, a strong industry and a step toward a cleaner future.  Learning how to use what the earth has provided is vital to the future. Success is dependent upon on a willingness to change our habits and move away from petroleum-based fuels.

Author: Benjamin Burroughs
Renewable Fuel Research, Angelina College
(936) 633-5353