A Feasibility Assessment of Waste Cotton to Bioenergy with Carbon Removal

KHONGPATIMAKORN, JUNE; CLAUSER, NICOLÁS M.; VENDITTI, RICHARD; SAGUES, JOE

Nebraska

Simposio; American Society of Agricultural and Biological Engineers; 2023

Cotton is the most widely used natural fiber in the world. It is also the second most used fiber for garment production behind polyester globally. Waste materials from cotton are produced throughout the life cycle of a cotton product. In addition, there is a growing need for bioenergy technologies that are net carbon negative, meaning they permanently remove carbon from the atmosphere. For the first time, we investigated the techno-economic feasibility and environmental benefits of different waste cotton valorization pathways with carbon removal. The geospatial distribution of waste cotton feedstock in the US for the year 2017-2020 were analyzed, revealing an average county-level availability of cotton residue at approximately 21,534 tons per year, or 66 tons per day with 90% utilization. Approximately 30% of the cotton crop is baled for further processing, while the rest of the residue is potentially available for bioenergy with carbon removal. Ginning was found to generate the largest amount of waste, with an estimated 10% of harvested cotton potentially available for bioenergy. The project developed process models in SuperPro to understand the mass and energy balances of the various bioprocesses and provide data for our economic model. Significant efforts have been made in academic research to address technical barriers in cotton reuse and recycling, but little research has been done on the technical feasibility and environmental benefits of different waste cotton options including use in biofuel creation with and without carbon capture. A good understanding of the quantity, type, and quality of the waste cotton within the supply chain will lead us to identify suitable solutions for recycling and reuse. Recycling and reuse of cotton can be done by having a full understanding of the waste cotton supply chain and life cycle assessment (LCA). There is also a lack of definition of the waste cotton supply chain pertinent to energy/biofuel production.