Organosolv fractionation of eucalyptus: Economics of cellulosic ethanol and chemicals versus lignin valorization to phenols and polyols

This work assessed the economics of the organosolv fractionation of eucalyptus to compare the returns from valorizing lignin to phenols and polyols with the production of cellulosic ethanol and chemicals. An organosolv plant, co-located with a eucalyptus kraft pulp mill in Brazil, that sells technical lignin at \$300/t, can produce glucose by enzymatic hydrolysis at a minimum selling price of 9.2c/lb (\$203/t). Investments to valorize the lignin to polyols can generate returns comparable to the production of cellulosic chemicals (Cumulative Cash Ratio between 2 and 4 depending on the plant scale) and are more profitable than producing either ethanol or non-upgraded products. Furthermore, for situations in which cellulolytic enzymes are not available at a competitive cost, this study concluded that eucalyptus pulp companies should prioritize their investments in the valorization of lignin to increase their odds of being competitive with sucrose produced by the sugarcane industry. (AU)