Alternatives to produce biorefinery products from sugarcane bagasse

CLAUSER, N.M.; GUTIÉRREZ, S.; AREA, M.C.; FELISSIA, F.E.; VALLEJOS, M.E.

Espoo

Conferencia; X Iberoamerican Conference on Pulp and Paper Research, CIADICYP; 2016

Aalto University

Productionprocesses of bioproducts and biofuels from lignocellulosic biomass can bedesigned at different scales (micro, small, medium and large). Some advantagesof small-scale biorefineries are the lower capital and logistics costs and thelower inversion risk than those in large-scale ones, in addition to thepossibility of labor occupation in rural areas. In this work, differentproducts from hemicelluloses and residual solids from the autohydrolysis ofsugarcane bagasse were studied to find the most feasible scenario for asmall-scale biorefinery. A model for autohydrolysis process was used todetermine optimum treatment conditions (time and temperature) using GAMSSoftware (CONOPT solver). The subsequent processes were estimated andcalculated based on experimental and updated bibliography. Finally, the totalcapital investment and IRR of each alternative were also estimated. In scenarioI, the evaluation included the production of xylose syrup, furfural and xylitolfrom hemicelluloses in the spent liquor of sugarcane bagasse autohydrolysis (15,000ton per year of bagasse), as well as energy generation and medium-densityfiberboard (MDF) production from the residual solid. Furfural with MDFproduction is also an alternative, but its IRR is lower. Despite of the highprice of xylitol, the IRR of its production is relatively low due to the highinvestment cost. Scenario II was proposed to improve the feasibility of xylitolproduction. Liquid-solid ratio of the autohydrolysis treatment was reduced from7:1 to 5.5:1 and the processing capacity was gradually increased up to 70,000ton per year. A 23% reduction in energy consumption respect to the firstscenario was verified. In these conditions, the production of xylitol andenergy generation (EG), MDF, ethanol, or pellets from the residual solid was evaluated(Table 1). IRR improved slightly for xylitol production compared to scenario 1.Higher IRR is obtained for xylitol and EG production. Simultaneous productionof xylitol and pellets is an interesting option when processing more than20,000 ton per year of bagasse, whereas xylitol and ethanol production need toprocess 70,000 ton per year to be attractive.