In order to establish suitable conditions for the production of feedstocks or liquid fuels from a renewable source, a liquefaction process of lignin obtained from sugar cane bagasse was investigated. Monoethanolamine was used as liquefaction solvent and hydrogen as pressurization gas. Liquefaction process was optimized using a modified simplex method consisting of three variables: temperature, time, and solute:solvent ratio. The goal of the proposed method was to maximize the yield in light oils that was achieved with a total of only 27 experiments and with a yield 5 times higher than the initial one, obtained before the optimization procedure.