Eichhornia crassipes (water hyacinth), is considered an aquatic pest. An alternative to solve the excess water hyacinth problem is to use the biomass for second generation ethanol. This process can be divided into: collection of biomass pre-treatment, enzymatic hydrolysis, fermentation and distillation. Some chemical processes for pre-treatment of biomass water hyacinths were evaluated to determine which procedure degrades the greater amount of lignin and hemicellulose which least affects the cellulose. Characterization was made from the analysis techniques: TG-DTA, XRD and FTIR. The results revealed that the biomass to water hyacinth the most efficient pre-treatment is chemical hydrolysis with sulfuric acid.