Production of biobased polyethylene terephthalate and its precursors for diversification in the global sugarcane industry

Abstract

The technical and economic viability of producing fully bio-based polyethylene terephthalate (PET) or its monomers was investigated. First generation (1 G) biorefineries, utilizing A-molasses, and combined first and second generation (1G2G) biorefineries, utilizing molasses and sugarcane bagasse and brown leaves, were considered. Simulations were developed self-sufficient, where the energy demand was met by utilizing the existing sugar mill boiler, accompanied by a new medium-pressure boiler and generator. 1G2G scenarios required the replacement of the sugar mill boiler with a new, high-efficiency combined heat and power (CHP) plant, where electricity and useful heat were generated from a portion of 2 G biomass and other residues. 1 G PET was unprofitable at a minimum selling price (MSP) of $2946.t-1. 1 G production of Ethylene ($1847.t-1), monoethylene glycol (MEG) ($1648.t-1), 5-Hydroxymethylfurfural (HMF) ($1576.t-1) and iso-butanol (iButOH) ($1292.t-1) were more economically viable than PET, terephthalic acid (TPA) ($2689.t-1) and p-xylene (PX) ($2983.t-1), due to less complex processing and lower energy demands. 1G2G biorefineries were less profitable than 1 G equivalents, due to the cost of pretreatment and new CHP plants. The most profitable scenario was 1 G iButOH, with an MSP 19.0% lower than its market price. New technologies to produce p-xylene and TPA from biomass in fewer steps, such as Virent Inc.’s Bioforming® technology, could potentially improve the economic viability of PET in the future.