Bagasse pulp waste (BPW) is a material generated from the depithing of sugarcane bagasse stems prior to pulping. It was subjected to a modified oxygen delignification or ammonia catalytic steam explosion (AE) pretreatment for delignification and retaining carbohydrates of raw materials, followed by simultaneous saccharification and co-fermentation (SSCF) to ethanol. Based on this process, an environmentally sustainable two-stage process for lignin purification was employed to obtain nontoxic “green lignin”. The results indicated that both pretreatment methods, particularly AE, had outstanding performance in the SSCF process. The highest ethanol yield (based on dry matter of BPW), 67.5% for the AE pretreatment, was obtained from the SSCF procedure at 8% (w/v) solids loading. Furthermore, the obtained lignin products from this process possessed better structural integrity.