Switchgrass as a Biofuel

Roland Centeno
January 22, 2019

Submitted as coursework for PH240, Stanford University, Fall 2018

Introduction

Fig. 1: A picture of switchgrass (Panicum virgatum), a biomass with great potential. (Source: Wikimedia Commons)

Apart from the most common renewable energy sources of hydropower, wind, and solar, other less common means of energy production also exist. Among these alternative energy sources is biofuel, which consists of converting organic materials from plants and animals into a renewable source of energy. Wood, crops, and waste are examples of biomass for this type of energy production. Among the most common currently used crops are corn and soybeans. [1] However, one crop with high potential that has not yet been greatly utilized thus far within the biodiesel industry is switchgrass (pictured in Fig. 1).

Advantages of Biofuel

A key advantage of biofuel over traditional fossil fuels is that it is renewable at much faster rate and much easier than coal or oil. In addition, biofuels are advantageous from an economic standpoint in that they reduce the dependency on foreign oil, as many countries to not have access to sufficient oil within their own borders to match their energy needs. [2] Furthermore, renewable energy sources such as biofuel have a more positive environmental impact than fossil fuels by having lower carbon emissions. An EPA report showed that renewable fuel results in a 20% savings in green house gases, and a 60% increase if biofuels are created from cellulosic biomass. [2] The use of biofuels can also reduce the amount of waste that needs to be placed in landfills as it is used for fuel instead. [2]

Advantages of Switchgrass

In addition to the advantages associated with biofuel in general, switchgrass in particular possess several specific attributes that make it an advantageous choice when considering different biomasses. For one, switchgrass grows in various conditions, ranging from arid sites in the shortgrass prairie to marshes and open woods. Its wide range of possible growing locations makes it an exceptional choice as it can grow in locations that other potential biomasses would not. [3] Within the United States certain ecotypes grow in wetter lands farther south, and other ecotypes grow in drier areas farther north. The many places it can grow mean it is easier to grow at high volumes compared to more particular potential biomasses. Lastly, it can serve other purposes besides its own growth. Switchgrass is effective at reducing erosion by holding soil in place, and therefore providing a habitat for wildlife. [3]

Challenges Associated With Switchgrass

One key challenge is the sheer volume of switchgrass that is necessary to produce a worthwhile amount of fuel. This leads to a high overhead in terms of constantly planting and harvesting the switchgrass, and the large tracts of lands needed to grow it. However, this problem is mitigated by the large range of places that switchgrass is capable of growing. In addition, much research has been done into the optimal conditions under which switchgrass must be grown and stored in order to maximize production. [2]

Conclusion

Biofuels provide a multitude of distinct advantages over traditional fossil fuels, and even other renewable energy sources. This fact makes them a strong candidate when considering alternative energy production. Furthermore, switchgrass specifically possesses several key qualities that make it a strong option among different biomass choices. If the challenges associated with it can be sufficiently addressed, it should definitely be explored as a potential clean, renewable, and easily produced energy source moving forward.

© Roland Centeno. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.

References

[1] E. Brandes, A. Plastina, and E. A. Heaton, "Where Can Switchgrass Production Be More Profitable than Corn and Soybean? An Integrated Subfield Assessment in Iowa, USA," GCB Bioenergy 10, 473 (2018).

[2] A. Monti, ed., Switchgrass: A Valuable Biomass Crop for Energy (Springer, 2012).

[3] C. A. Gunderson et al., "Exploring Potential U.S. Switchgrass Production for Lignocellulosic Ethanol," Oak Ridge National Laboratory, ORNL/TM-2007/183, August 2008.