Growing Crops for Biofuel Feedstock Production
Growing bioenergy crops that can be used to produce biofuels has become a hot topic because such crops present a promising source of biofuel to replace fossil fuels. Much of this interest in the soybean world has been “fueled” by soybean’s position as the preeminent feedstock for the production of renewable diesel [RD]. In fact, soybeans are considered the “go to” feedstock for RD biofuel production.
RD is just one form of biofuel, and other crops and non-crop commodities such as algae can be grown to be used as a feedstock for other biofuels. However, the growing of crops solely for biofuel production faces criticism because it may potentially encroach on the arable land that is essential for food production. Thus, there is growing interest in and consideration for identifying bioenergy cropping systems that are suitable for use on marginal land sites, or sites that are less suited for food crop production.
A July 2024 article titled “Which Biofuels Crops Work Best and Where?” provides insight into just what crops producers should consider for biofuel production based on their U.S. location. This article cites research conducted using biomass from four non-leguminous, high-cellulose plant species [corn (stover), energy sorghum, miscanthus, and switchgrass] that can be used to create biofuels. The following are major points from the article.
• Univ. of Illinois scientists assessed the financial and environmental impacts of growing the above four crops [all C4 species] in rainfed environments to provide feedstock that can be used to create sustainable aviation fuel [SAF] in the U.S.
• The study aimed to identify the feedstock with the lowest breakeven price and carbon [C] intensity [CI] score for growers switching from another crop. They also considered the cost of C abatement and the amount of biomass produced per unit of land.
• The average yield of the 3 energy crops was greater than 4X that of corn stover. Also, the choice of feedstock crop based on yield varied among regions of the country.
• The analysis used in the study quantified the significant potential for SAF production from energy crops to reduce greenhouse gas [GHG] intensity of aviation fuels.
• Corn stover-based SAF had the lowest breakeven price per gallon of fuel produced, but it had the highest cost of GHG abatement.
• In the final analysis, identifying and quantifying factors that are important in the production of SAF from bio-feedstocks , while also identifying specific regions of the country where a particular feedstock species performs best, will be necessary for the development of policies and incentives that will be needed to encourage use of bio-feedstocks for SAF production.
• The researchers concluded that either carbon prices will need to increase or the cost of producing SAF’s will need to decrease to make SAF’s an economically viable alternative to current jet fuel.
An article titled “ISU studies explore win-win potential of grass-powered energy production” cites results from research reported in articles titled “Optimal production and dispatch of renewable natural gas, electricity, and fertilizer in municipal-scale anaerobic digestion supply chains”and “Techno-economic and life cycle analysis of renewable natural gas derived from anaerobic digestion of grassy biomass: A U.S. Corn Belt watershed case study”. The research was conducted by scientists at Iowa State Univ. and used various organic residues as feedstock to produce renewable natural gas [RNG]. A brief summary of results from that research follow.
• Global energy consumption is increasing. Thus, there is an increasing demand for renewable energy sources to replace fossil fuels.
• The analyses reported in the above articles indicates that RNG production by anaerobic digesters [AD] that use organic materials is a viable alternative to renewable electricity.
• Using grassy biomass from restored native grasslands to produce RNG through AD provides opportunity for sustainable biofuel production from marginal or low-productivity farmland, and could promote ecosystem services and markets for C credits.
• The economics for grass-to-gas production of biofuel depends on biomass yield and existing environmental credits or credits that may become available.
• Land use scenarios with the greatest biomass yield represent the most attractive economic outcomes because of more feedstock available to produce more RNG.
• Robust policies that support environmental credits are needed to realize the most economic and environmental value from RNG production from grassy biomass that can be produced on marginal cropland.
While none of the above-cited research projects involve using soybeans to make biofuel, they do involve instances where the production of fuel from plant materials is being researched. And since the development of renewable energy sources to replace fossil fuels is needed, soybean producers should consider how results from the above research projects might fit into their current production systems. After all, it could be that a diversified program other than the oft-used corn-soybean rotation might be more profitable in the long term if markets for biofuel feedstocks are in place and/or continue to develop. Thus, consideration of such added diversity might enhance the profit potential for soybean producers.
Of course, use of a more diversified production system to produce biofuel feedstocks such as those above will need to ensure the marketability of products from that system. Regrettably, marketing opportunities for biofuel feedstocks are just now being realized in the southern U.S., so soybean producers need to ensure there is a viable and sustainable market for alternative crops they may be considering to grow for biofuel feedstock material.
Composed by Larry G. Heatherly, Aug. 2024, larryh91746@gmail.com