Production of biobased polyethylene terephthalate and its precursors for diversification in the global sugarcane industry
Janus Louw, Somayeh Farzad, Johann F. Görgens
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.