Techno-economic analysis of chemically catalysed lignocellulose biorefineries at a typical sugar mill: Sorbitol or glucaric acid and electricity co-production.

Global concerns about depletion of fossil reserves has driven countries towards bio-economies utilising mostly first generation feedstocks. The economic viability of energy self-sufficient biorefineries processing sugarcane lignocelluloses into sorbitol or glucaric acid and electricity was investigated. Aspen Plus® simulations represented glucose conversion processes via SO2-steam explosion or dilute acid pre-treatment, followed by enzymatic hydrolysis. The most economically viable sorbitol scenario using dilute acid pretreatment with a capital investment cost per litre of US$ 3.96/L was marginally profitable having a selling price 5% below the US$ 655/t market price. To secure private investment, the sorbitol selling price should reach US$ 1283/t.