Economic comparison of decentralized versus centralized processing of sugarcane to fructooligosaccharides and ethanol

Abstract

The global sugarcane industry is under threat due to low international prices and oversupply. This requires new revenue opportunities through a diversification strategy. The economic competitiveness of small‐scale, decentralized biorefineries to produce short‐chain fructooligosaccharides (scFOS) and/or ethanol, both valuable products with growing market applications, in comparison to large‐scale, centralized facilities annexed to existing sugarcane mills, was therefore considered. The economic feasibility of three potential scenarios was investigated using AspenPlus process simulations of small‐ and large‐scale facilities. In Scenario 1 only scFOS was produced. In Scenario 2 only ethanol was produced, and in Scenario 3 scFOS and ethanol were co‐produced. The small‐scale implementation of Scenarios 1 and 3 was economically feasible, with minimum selling prices (MSPs) below market prices. However, in all scenarios the large‐scale implementation of technologies in facilities annexed to an existing sugar mill improved economic viability, despite efforts to minimize the disadvantages of small‐scale facilities and their capital costs through the selection of simplified process technologies and decentralized processing. Despite this, the small‐scale production of scFOS is the preferred investment option for scFOS production due to the very high scFOS production rates of the large‐scale scenarios, which could flood the market. Processing of freshly harvested sugarcane in decentralized, small‐scale facilities increased the feedstock cost per unit of sugar, in comparison with the use of molasses obtained by annexation to an existing sugar mill. Simplified sugarcane processing to ethanol also lowered the product yield and increased capital costs. Further improvements in process technology design and performance for small‐scale facilities are required to make these financially competitive with large‐scale facilities.