Green H2 impacts carbon-footprint for bio-based commodities: A gate-to-gate study on production of 1,3-propanediol

Abstract

Sustainable use of hydrogen (H₂) has been a central task for both energy and chemical industry. However, the positive impact of green H₂ on reduction of carbon emission has yet to be rationally assessed in the area of bio-refineries. In this work, the CO₂ emission and the environmental impact for manufacture of bio-based 1,3-propanediol (1,3-PDO), a key monomer for megaton polytrimethylene terephthalate (PTT), has been evaluated to reveal the carbon footprint of both fermentation and hydrogenolysis methods. Particularly, it is found that, overall CO₂ emission from fermentation processes still outstands hydrogenolysis technology, despite of a much lower product concentration in effluent streams. But substituting grey H₂ with green sources in hydrogenolysis scheme leads to a total reduction of 61.7% in CO₂ emission. Therefore, manufacture of 1,3-PDO via chemical method would potentially outperform conventional fermentation technique in productivity in light of green H₂ economy and improved catalytic efficiency. This work will provide a useful technoeconomic methodology to evaluate the carbon footprint of various other key bio-based commodity products, toward a net-zero carbon goal for future bio-refining industry.