Cotton Gin By-Products Utilization: Past, Present, and Future

Abstract

The regional concentration of cotton gin by-products (CGB) has increased significantly over the past three decades because of the consolidation of smaller gins into larger gins. Although several studies have investigated the potential of various waste treatment/valorization technologies to improve the management of CGB, most of the technologies' economic feasibility remains a challenge. Therefore, there is a need to review the existing and emerging technologies vis-à-vis process economics and changes in the cotton ginning industry. This study reviews the published status of these existing technologies (in terms of the challenges and potentials), analyzes the prospects of some emerging waste treatment technologies for CGB, and discusses future economic and environmental sustainability directions. Where appropriate, new information from studies conducted in the U.S. and Australia is provided to support existing published data. The results show that the main limiting factors include production costs (e.g., energy and feedstock/additives costs) and logistics/supply. Additionally, the results support a solid potential for the sustainable use of CGB for various applications. However, the potential can be achieved by optimizing specific treatment processes, combining multiple processes through hybrid or integrated systems, co-treating CGB with other affordable and readily available materials (such as by-products from other agricultural operations), and improving return on investment for products developed.