CHE.10 From Waste to Wonder: Bacterial Synthesis of 1,3-Propanediol from Crude Glycerol

• Jesse Anderson
• Abdul Hamideh
• Thanh Nguyen
• Ayush Patel
• Andres Rodriguez-Castro

The primary objective of this project is to develop a more sustainable and optimized biogenetic route for the production of 1,3-propanediol (1,3-PDO), an essential compound with high demand in various industries such as cosmetics, and cleaning products, which is used in the production of polytrimethylene terephthalate (PTT) for carpets and textiles. Traditional petrochemical methods for 1,3-PDO production operate at high temperatures and pressures, involve the use of toxic chemicals, result in numerous side reactions, and are less environmentally friendly. The proposed bio-based process, in contrast, utilizes crude glycerol as a substrate in a fermentation setup, which leads to fewer synthesized toxic chemicals and improved sustainability.
The existing bio-based 1,3-PDO production process by DuPont employs an engineered E. Coli strain, which, despite its advantages over petrochemical routes, presents risks such as potential pathogenicity and the generation of unwanted side products. This project addresses these limitations by redesigning the DuPont model and incorporating several innovative improvements. These include the use of an optimal anaerobic bacterial strain, Lactobacillus reuteri CH53, which not only reduces the carbon footprint but also preferentially employs the anaerobic pathway for cell division, leading to fewer side products and reduced energy consumption during the distillation process. In the enhanced process being proposed, roughly 86% of water is recycled in the process for resource conservation and reducing environmental impact. This is done via reverse osmosis, an effective process in which the water is removed using a membrane filter and recycled into the blending tanks that carry the media for the process. Additionally, 70% of CO2 produced as a result of cellular metabolism is diverted to a greenhouse to generate plant biomass to maintain a more friendly environment.
Furthermore, this project explores the use of corn steep liquor (CSL) which is up to a fifth of the cost of yeast and yields higher productivity than alternative nitrogen sources such as beef extract. The biomass separation is also optimized by implementing a combination of hydrocyclone units and ultrafiltration, which allows for more effective removal of biomass before the final product extraction. These changes collectively contribute to a more economical, sustainable, and efficient production process for 1,3-PDO.
The projected production rate is 60,000 tons per year with a purity of 99.54%, resulting in an annual gross profit of $107 MM. Additionally, the project includes the sale of byproducts such as ethanol (99.99% purity), acetic acid (99.16% purity), and lactic acid (98.16% purity), which will generate additional revenue of $71 MM. After a plant life of 20 years, the project’s Net Present Value (NPV) is estimated to be $266 MM, taking into account a tax rate of 29.75% and a discount rate of 14%.
Additionally, the findings of this project could inspire further research and development of alternative biobased processes for other high-demand compounds, contributing to the global movement towards greener and more sustainable chemical production methods.