A techno-economic and life cycle assessment of multiproduct sugarcane biorefinery: Lactic acid as a platform chemical

Abstract

Platform chemicals are increasingly sourced from renewable biomass feedstocks such as sugarcane, to reduce fossil fuel dependence. Lactic acid (LA) is an example platform chemical that can be produced from biomass with diverse uses and chemical derivatives. However, its potential as a platform chemical within the context of a biorefinery remains unexplored. In this study six configurations of a multiproduct biorefinery converting A-molasses into LA or its derivatives: acrylic acid (AA), propylene glycol (PG), polylactic acid (PLA), and ethyl lactate (EL) were investigated. Simulations were developed using Aspen Plus® and SimaPro® to evaluate internal rates of return (IRRs) and global warming potential (GWP). The study showed that the multiproduct scenario converting LA to EL, PLA and AA had the highest IRR of 27 % with a 91 % probability of success, and a low GWP of 0.84 kg CO 2 eq/kg feedstock which was the preferred scenario for the multiproduct. Addition of PG to the multiproduct reduced the IRR (23 %, 50 % probability of success) and a slightly increased GWP of 0.86 kg CO 2 eq/kg feedstock . Although multiproduct options provided diverse revenue streams, producing the biorefinery scenario considering LA production offered a higher IRR (65 %). Subsequently, price increases above 50 % for AA and PG were found to be necessary to make them competitive with monomeric LA production. This study highlights the economic advantages of LA production while investigating its potential for development as a platform chemical in a multiproduct biorefinery annexed to a sugarcane mill. • Lactic acid production is economical compared to use in a multiproduct facility. • Large scale production of LA however has the challenge of potentially flooding the market. • Propylene glycol production in the multiproduct reduces profitability of the process. • Acrylic acid and propylene glycol require a premium (>50 %) to compete with LA.