The United States generates approximately 14.5 billion tons of waste per year, with 15% of this waste falling into the organic waste category [1], [2], [3], [4]. This represents a significant environmental impact, with emissions equivalent to roughly 195 million tonnes of CO
2e/yr [5], as well as the loss of important materials such as copper, zinc, and cadmium [6]. To address this challenge, Upcycle Technologies partnered with us to develop a feedstock-agnostic system capable of handling high-moisture wastes such as animal manure, agricultural residue, and raw sewage. High-moisture wastes are notoriously difficult to process due to high drying costs and low-quality products. However, our design, which combines a high-pressure hydrothermal liquefaction reactor with a high-temperature gasifier, has shown to be capable of handling organic wastes with up to 85% moisture. Preliminary results from testing with various feedstocks, including cracked corn, rabbit feed, and chicken and sow manures, have demonstrated promising results, including carbon efficiencies up to 61%, overall thermal efficiencies up to 67%, feedstock conversion efficiency up to 57%, and heat loss up to 9.2%. Notably, these results were achieved without any heat integration or optimizations, suggesting significant potential for further improvement. These preliminary results from the Upcycle prototype have demonstrated the feasibility of combining a hydrothermal liquefaction unit with a gasifier to process high-moisture wastes. The achieved performance metrics suggest that this approach may be a viable option for waste-to-energy applications where conventional WtE technologies, such as RDF or mass burn, aren’t appropriate. Further research is needed to better understand the limitations and further potential applications of this technology.
References
[1] O. US EPA, “National Overview: Facts and Figures on Materials, Wastes and Recycling.” Accessed: Apr. 07, 2025. [Online]. Available: https://www.epa.gov/facts-and-figures-about-materials-waste-and-recycli…
[2] “2019 Wasted Food Report,” EPA, EPA 530-R-23-005, Apr. 2023. [Online]. Available: https://www.epa.gov/system/files/documents/2024-04/2019-wasted-food-rep…
[3] “Advancing Sustainable Materials Management: 2018 Fact Sheet,” EPA, Washington, D.C., EPA 530-F-20-009, Dec. 2020. [Online]. Available: https://www.epa.gov/sites/default/files/2021-01/documents/2018_ff_fact_…
[4] “Biosolids Generation, Use, and Disposal in the United States,” EPA, Washington, D.C., Reports and Assessments EPA530-R-99–009, Sep. 1999. Accessed: Apr. 07, 2025. [Online]. Available: https://www.epa.gov/biosolids/biosolids-generation-use-and-disposal-uni…
[5] EPA, “Waste Reduction Model.” Accessed: Apr. 07, 2025. [Online]. Available: https://www.epa.gov/warm
[6] “Removal and Recovery of Metals and Phosphates· from Municipal Sewage Sludge,” EPA, Cincinnati, OH, EPA-600/2-80-037, Jun. 1980. Accessed: Apr. 07, 2025. [Online]. Available: https://www.epa.gov/sites/default/files/2019-12/documents/removal-recov…
