Agricultural waste and residue biomass availability in the near term (5 - 10 years) is estimated to be 140 million dry tons per year

Summary

Agricultural wastes and residues represent a significant biomass feedstock source for second-generation biofuels, offering near immediate availability and easy collection while providing financial benefits to farmers. The United States Department of Energy's 2023 Billion Ton Report estimates near-term availability at 140 million dry tons per year, with corn stover comprising the majority at 114 million tons. Key assumptions include a base price of $70 per ton, soil health constraints requiring residue retention, and only 60% farmer participation. The report accounts for sustainability factors like erosion prevention and local conditions while excluding climate change impacts. Agricultural residues dominate the biomass supply, with processing waste from pruning operations contributing smaller amounts.

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Agricultural wastes and residues make up an important portion of the biomass feedstock available for 2nd generation biofuels. The primary benefit of utilizing agricultural waste and residues as a feedstock is that they are for all intents and purposes, available for use immediately and are easy to collect. Additionally, they have the ability to provide financial benefits to farmers for what might usually be considered a 'waste' product. Estimates of the amount of waste and residue available depend on the maturity of biomass markets and the amount of residues that need to be left on the field to maintain soil health and prevent erosion.

Figures for biomass availability are sourced from the United States Department of Energy's 2023 Billion Ton Report, which is the fourth edition of the billion ton report that attempts to estimate the amount of biomass available in the United States by taking into account sustainability, economics, and technical feasibility ^{1 2}.

Assumptions

• The 2023 billion ton report assumes a base value of $70 per ton delivered for agricultural residues which was chosen by the authors of the report as a reasonable estimate for a baseline price.

• The "near term" biomass estimates for agricultural residues are utilized in this analysis. In this regard, near-term is characterized by biomass that is available for use within the next 5–10 years (2030). Estimates are available for low, medium and high maturity markets projected 20 years out, with various assumptions relating to assumed advances in collection technology and rises in conventional crop yields

• The US billion ton report takes into account the fact that a percentage of crop residues need to be left on the field to maintain soil health and prevent erosion. Calculations are done on a location basis, which takes into account local conditions such as hydrology and the slope of the land

• The US billion ton report also takes into account the fact that a maximum of 60% of farmers would be willing to harvest residues from their fields

• Biomass estimates do not take into account the effects of climate change on crop yields

• Biomass estimates assume that the corn ethanol industry is still in operation, this is important as a significant portion of the estimated biomass is from corn stover that is produced by the corn ethanol industry.

Estimations of Agricultural Waste and Residues

The total near-term agricultural waste and residue biomass availability is estimated to be 140 million dry tons per year, taking into account soil health constraints.

Table 1: Near-term agricultural waste and residue biomass availability

Category	Feedstock	Quantity (million dry tons/year)
Agricultural Residues	Corn Stover	114.33
	Wheat Straw	14.40
	Rice Straw	3.31
	Oats Straw	<10,000 tons
	Barley Straw	0.25
	Sorghum Stubble	0.57
	Cotton Field Residues	0.82
Agricultural Processing Waste	Pruning Residues – Citrus	1.32
	Pruning Residues – Tree Nuts	1.92
	Pruning Residues – Non-Citrus	2.81
Total	—	140

Sources

Footnotes

1. Langholtz, M. H. (Lead). (2024). 2023 Billion-Ton report: An assessment of U.S. renewable carbon resources (ORNL/SPR-2024/3103). Oak Ridge National Laboratory. https://doi.org/10.23720/BT2023/2316165 ↩

2. U.S. Department of Energy. (2023). Billion-Ton 2023 data portal. Bioenergy Knowledge Discovery Framework. https://bioenergykdf.ornl.gov/bt23-data-portal ↩