Techno-economic assessment of carboxylic acids, furfural, and pellets production in a pine sawdust biorefinery

CLAUSER, NICOLÁS; GUTIÉRREZ, SOLEDAD; AREA, MARÍA; FELISSIA, FERNANDO; MARÍA EVANGELINA VALLEJOS

Biofuels, bioproducts and Biorefining

Wiley

Año: 2018

1932-1031

Pine sawdust is an important lignocellulosic waste from the primary industrialization of wood and its valorization using the biorefinery concept could add new value chains to the forest industry. Compared with large-scale biorefineries, small-scale ones involve lower capital and logistics costs, lower risk, and can increase the labor occupation in rural areas. A scheme was proposed for the use of the hemicelluloses obtained from the spent liquor of a steam explosion pretreatment of pine sawdust. With the proposed scheme levulinic acid, formic acid, acetic acid and furfural are obtained from the liquid fraction while pellets is produced from the solid fraction. This pine sawdust biorefinery allows obtaining about 747 kg of pellets, 57 kg of levulinic acid, 23 kg of formic acid, 18 kg of acetic acid, and 22 kg of furfural per 1000 kg of dry sawdust. The energy used for levulinic acid production is one of the main production costs. When 95% of the residual solid is used to generate steam, there is an improvement in the internal rate of return (IRR). The heat integration allows a reduction of 10% in the steam consumption for LA, increasing the capacity of pellets production. Therefore, the obtained results are key to found alternatives for pine sawdust biorefinery focusing on the improvement of the production processes, the satisfaction of the energy requirements, and the reduction of the recovery costs. Three alternatives for the valorization of pine sawdust were analyzed and the best of them obtained an IRR of about 17%.