Optimization of process variables for alkali delignification of sugar caneat atmospheric pressure

Bundles of fibers were extracted from the rind of sugar cane, and their fea sibility for geotextile and textile applications was investigated as value- added agricultural waste by-products. Three distinct steps were used to obt ain the ultimate product: mechanical separation, chemical extraction (retti ng), and steam explosion. The input variables for the process were consider ed: alkali concentration in solution (expressed as normality), reaction tim e, frequency of tumbling (expressed as the time interval between two succes sive tumbling sessions), volume of alkali solution, initial rinds mass, typ e of rind, and the presence of steam explosion. Statistical analysis of con ducted experiments showed a complex dependency between the input variables and the final characteristics of the fiber bundles. Response surface models for lignin extraction, NaOH consumption, agitation factor and characteristics properties of the final fibers (length, weight a nd tex) were obtained considering normality of alkali solution, the reactio n time, and the interval between two consecutive agitations. Polynomial mod els were used to optimize the process for obtaining fibers suitable for tex tile purposes.