Toray and PTTGC developed waste-based bio-adipic acid technology, enabling 100% bio-based nylon 66 production from cassava pulp residues.
The development of sustainable and renewable raw materials is becoming increasingly important as industries worldwide seek to lower greenhouse gas emissions and reduce their reliance on fossil-based resources. In response to this growing demand, Toray Industries, Inc. of Japan and PTT Global Chemical PLC (PTTGC) of Thailand have successfully established an innovative production pathway for bio-based adipic acid, a key ingredient used in the manufacture of nylon 66. Their breakthrough technology enables the conversion of agricultural waste into valuable industrial materials, culminating in the production of 100% bio-based nylon 66.
The new process utilizes cassava pulp, a byproduct generated during starch extraction from cassava roots. Cassava is widely cultivated for food and industrial applications, making cassava pulp an abundant and consistently available waste material. Since this residue does not compete with food production and requires no additional farmland, its utilization helps minimize the risk of indirect land-use change (ILUC), a major environmental concern associated with some bio-based feedstocks. By transforming an underutilized agricultural byproduct into a high-value chemical ingredient, the companies are advancing the principles of a circular and sustainable economy.
To establish this production route, Toray and PTTGC conducted a series of demonstration projects covering the entire manufacturing chain, from feedstock processing to fiber production.
The first stage involved saccharification, where starch residues were converted into glucose sugars. Toray demonstrated an energy-efficient and high-quality saccharification process using membrane separation technology. Through this method, approximately 66 tonnes of cassava pulp containing around 85% moisture were processed daily to generate five dry tonnes of glucose sugar. This achievement confirmed the viability of converting agricultural waste into fermentable sugars on a meaningful scale.
The second stage focused on fermentation. PTTGC employed its proprietary microbial strain to convert the glucose sugars into bio-muconic acid, an important intermediate chemical. The company successfully demonstrated stable and efficient production of bio-muconic acid fermentation broth, validating the process from laboratory experiments through pilot-scale operations using fermenters with a capacity of roughly 50 cubic meters. This milestone highlighted the scalability of the technology and its potential for future commercial deployment.
Following fermentation, both companies collaborated on the refinement stage. Using jointly developed purification technologies, they succeeded in extracting high-purity bio-muconic acid from the fermentation broth. The refined product met the quality requirements necessary for subsequent conversion into bio-based adipic acid.
In the chemical conversion phase, Toray demonstrated the transformation of bio-muconic acid into bio-based adipic acid while maintaining the purity standards required for nylon 66 production. Achieving such quality is critical because adipic acid serves as one of the principal building blocks in nylon polymerization.
The final stage involved polymerization and fiber formation. Toray successfully produced nylon 66 at the laboratory scale using bio-based adipic acid together with bio-based hexamethylenediamine (HMDA). The company also demonstrated fiber processing, proving that the resulting material can be manufactured into textile-grade nylon 66 while maintaining its fully bio-based composition.
Looking ahead, Toray and PTTGC plan to further expand production capacity and improve cost competitiveness for both bio-muconic acid and bio-based adipic acid. Their long-term objective is to establish a robust commercial supply chain capable of supporting large-scale production of sustainable nylon materials. Toray aims to begin commercial sales of textile products made from 100% bio-based nylon 66 by fiscal year 2028, marking a significant step toward reducing the environmental footprint of the global textile and chemical industries.
