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

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.