Techno-economic feasible and sustainable C-lignin biorefinery

Abstract

C-lignin, a homo-biopolymer, has great potential as a feedstock for biorefineries that convert it into high value-added products, for example, catechol as a precursor of pharmaceuticals. In this study, we conducted a techno-economic analysis (TEA) and life cycle assessment (LCA) of a conceptual biorefinery where waste castor seed coats are converted into high value-added products, including pulp, catechol, oligomers, and propylene. After a number of optimizations through scenario studies, when the incorporation of combined heat and power (CHP) and pressure swing adsorption (PSA) systems, importing heat and electricity instead of natural gas, bio-catechol has a minimum selling price (MSP) of $2.02 per kg, 23% lower than the market price, and a carbon footprint of 1.58 kg CO2 eq. per kg, 72% lower than that of fossil derived catechol. In addition, the use of district heat co-generated by natural gas or biogas CHP plants can further reduce the GWP of bio-catechol, but with trade-offs in other environmental impacts. Nevertheless, this study has proposed potential economically viable and sustainable C-lignin biorefineries with products to replace fossil derived catechol.